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Sample records for transesterificacao nao catalitica

  1. Temperature influence on biodiesel production by non-catalytic transesterification; Influencia da temperatura na producao de biodiesel por transesterificacao nao catalitica

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Humberto N.M.; Oliveira, Thomas R; Sousa, Elisa M.B.D. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    The main objective of this paper is to produce biodiesel using supercritical fluids through of the transesterification process without use of catalysts. It become easier the separation of the reaction products when compared with conventional method. In this work the influence of the temperature in the production of biodiesel from mamona oil was studied. Tree temperatures were studied (473.15 K, 523.15 K and 573.15 K) and the pressure (300 bar) and molar ratio (1:40) was keep constant during the process. Excess of Alcohol was used for this synthesis. The influence of temperature on the conversion and the reaction time was evaluated. The castor bean oil and biodiesel obtained were characterized in relation to their properties more significant. For results, higher conversions were found at higher temperatures (573.15 K), however can see a trend to the stability of reaction. The quality of the product was suitable for most properties evaluated. The equipment designed and built for this purpose was feasible but require some modifications to its optimization. The reaction of biodiesel production was confirmed, even without the addition of catalyst. It was the need to use a large excess of alcohol in relation to oil on this route without catalytic converters. In the case of the route of biodiesel production without the addition of catalysts, was felt the need to use excess alcohol in relation to the castor bean oil. (author)

  2. Climate impacts of the NAO are sensitive to how the NAO is defined

    Science.gov (United States)

    Pokorná, Lucie; Huth, Radan

    2015-02-01

    We analyze the sensitivity of the effects the North Atlantic Oscillation (NAO) exerts on surface temperature and precipitation in Europe to the definition of the NAO index. Seven different NAO indices are examined: two based on station sea level pressure (SLP) data, two based on action centers, and three based on correlation/covariance structures described by principal component analysis (PCA). The analysis is based on monthly mean data; winter and summer seasons are analyzed separately. Temporal correlations between indices are weaker in summer than in winter for most pairs of indices. In particular, low correlations are found between station indices on the one hand and PCA-based indices on the other hand. The NAO effects are quantified by correlations between the indices and station data in Europe. Effects of the NAO on precipitation amount and wet day probability are very similar, while NAO effects on maximum temperature are stronger than those on minimum temperature. The sensitivity of the NAO effects on both surface temperature and precipitation to the choice of the NAO index is considerably higher in summer. Correlations differ among the NAO indices not only in their magnitude but in some regions in summer also in their sign. These effects can be explained by a northward shift of the whole NAO pattern and its action centers in summer, away from the sites on which the station indices are based, and by a decoupling of the Azores high and Icelandic low from the centers of high covariability, identified by PCA. Considerable differences in SLP anomaly patterns associated to individual NAO indices also contribute to different responses in temperature and precipitation. Finally, we formulate two recommendations to future analyses of NAO effects on surface climate: use several different NAO indices instead of a single one, and for summer do not use station indices because they do not represent the circulation variability related to the NAO.

  3. Thua nao: Thai fermented soybean

    Directory of Open Access Journals (Sweden)

    Ekachai Chukeatirote

    2015-09-01

    Full Text Available Thua nao is a traditionally fermented food in Thailand. It is manufactured by fermenting cooked soybeans with naturally occurring microbes. There are also similar products including natto in Japan, kinema in India, and chongkukjang in Korea. In Thailand, thua nao is widely consumed, especially by people in the northern part. The product is generally regarded as a protein supplement and widely used as a condiment. Two major types of thua nao can be distinguished; fresh and dried forms. To date, scientific information on thua nao is scarce and thus this article aims to document the updated knowledge of Thai thua nao.

  4. High-Performance Na-O2 Batteries Enabled by Oriented NaO2 Nanowires as Discharge Products.

    Science.gov (United States)

    Khajehbashi, S Mohammad B; Xu, Lin; Zhang, Guobin; Tan, Shuangshuang; Zhao, Yan; Wang, Lai-Sen; Li, Jiantao; Luo, Wen; Peng, Dong-Liang; Mai, Liqiang

    2018-06-13

    Na-O 2 batteries are emerging rechargeable batteries due to their high theoretical energy density and abundant resources, but they suffer from sluggish kinetics due to the formation of large-size discharge products with cubic or irregular particle shapes. Here, we report the unique growth of discharge products of NaO 2 nanowires inside Na-O 2 batteries that significantly boosts the performance of Na-O 2 batteries. For this purpose, a high-spin Co 3 O 4 electrocatalyst was synthesized via the high-temperature oxidation of pure cobalt nanoparticles in an external magnetic field. The discharge products of NaO 2 nanowires are 10-20 nm in diameter and ∼10 μm in length, characteristics that provide facile pathways for electron and ion transfer. With these nanowires, Na-O 2 batteries have surpassed 400 cycles with a fixed capacity of 1000 mA h g -1 , an ultra-low over-potential of ∼60 mV during charging, and near-zero over-potential during discharging. This strategy not only provides a unique way to control the morphology of discharge products to achieve high-performance Na-O 2 batteries but also opens up the opportunity to explore growing nanowires in novel conditions.

  5. On the Stability of NaO2 in Na-O2 Batteries.

    Science.gov (United States)

    Liu, Chenjuan; Carboni, Marco; Brant, William R; Pan, Ruijun; Hedman, Jonas; Zhu, Jiefang; Gustafsson, Torbjörn; Younesi, Reza

    2018-04-25

    Na-O 2 batteries are regarded as promising candidates for energy storage. They have higher energy efficiency, rate capability, and chemical reversibility than Li-O 2 batteries; in addition, sodium is cheaper and more abundant compared to lithium. However, inconsistent observations and instability of discharge products have inhibited the understanding of the working mechanism of this technology. In this work, we have investigated a number of factors that influence the stability of the discharge products. By means of in operando powder X-ray diffraction study, the influence of oxygen, sodium anode, salt, solvent, and carbon cathode were investigated. The Na metal anode and an ether-based solvent are the main factors that lead to the instability and decomposition of NaO 2 in the cell environment. This fundamental insight brings new information on the working mechanism of Na-O 2 batteries.

  6. Radiological findings in NAO syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Al-Otaibi, Leftan; Hugosson, Claes O. [Department of Radiology, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Al-Mayouf, Sulalman M.; Majeed, Mahmoud; Al-Eid, Wea' am; Bahabri, Sultan [Department of Paediatrics, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia)

    2002-07-01

    Background: Diseases exhibiting osteolysis in children are rare hereditary conditions. Several types have been recognised with different clinical manifestations. One type includes subcutaneous nodules, arthropathy and osteolysis and has been termed NAO syndrome. Previous radiological reports have described the affected bones, usually the carpal and tarsal regions, but a detailed analysis of the radiological findings of both the axial as well as the appendicular skeleton has not been reported. Objectives: To describe the radiological findings in a large group of children with an autosomal recessive disease characterized by nodules, familial arthropathy and osteolysis. Materials and methods: The study comprises 14 patients from 9 families and all patients had the triad of nodulosis, arthropathy and osteolysis (NAO). Results: The most common radiological manifestations were osteopenia, undertubulation of long bones, arthritic changes, sclerotic sutures of the calvaria, osteolysis and muscle contractures. Other common findings were squared vertebrae, broad medial clavicles and brachycephaly. Progress of disease was documented in more than half of the patients. Conclusions: Our study is the first report of the detailed radiological findings of NAO syndrome. In NAO syndrome, both the axial and appendicular skeleton are involved (orig.)

  7. Radiological findings in NAO syndrome

    International Nuclear Information System (INIS)

    Al-Otaibi, Leftan; Hugosson, Claes O.; Al-Mayouf, Sulalman M.; Majeed, Mahmoud; Al-Eid, Wea'am; Bahabri, Sultan

    2002-01-01

    Background: Diseases exhibiting osteolysis in children are rare hereditary conditions. Several types have been recognised with different clinical manifestations. One type includes subcutaneous nodules, arthropathy and osteolysis and has been termed NAO syndrome. Previous radiological reports have described the affected bones, usually the carpal and tarsal regions, but a detailed analysis of the radiological findings of both the axial as well as the appendicular skeleton has not been reported. Objectives: To describe the radiological findings in a large group of children with an autosomal recessive disease characterized by nodules, familial arthropathy and osteolysis. Materials and methods: The study comprises 14 patients from 9 families and all patients had the triad of nodulosis, arthropathy and osteolysis (NAO). Results: The most common radiological manifestations were osteopenia, undertubulation of long bones, arthritic changes, sclerotic sutures of the calvaria, osteolysis and muscle contractures. Other common findings were squared vertebrae, broad medial clavicles and brachycephaly. Progress of disease was documented in more than half of the patients. Conclusions: Our study is the first report of the detailed radiological findings of NAO syndrome. In NAO syndrome, both the axial and appendicular skeleton are involved (orig.)

  8. Kinematic Model of NAO Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Miloš D. Jovanović

    2014-06-01

    Full Text Available This paper presents synthesis of kinematic model of NAO humanoid robot of Aldebaran Robotics. NAO humanoid robot has complex kinematic structure with 25 active degrees of freedom (DOF. Humanoid system is formed through 5 mutually depended kinematic chains. After that we applied standard aspects of kinematic chains synthesis and Denavit-Hartenberg parameters of each of 5 chains of robotic structure were introduced. Also, mutual relationships between chains were described, as well as their physical and structural dependence. Generated kinematic model will be the starting point for further dynamical modeling of NAO humanoid robot and motion synthesis on actual platform.

  9. Hierarchical Porous Carbon Spheres for High-Performance Na-O2 Batteries.

    Science.gov (United States)

    Sun, Bing; Kretschmer, Katja; Xie, Xiuqiang; Munroe, Paul; Peng, Zhangquan; Wang, Guoxiu

    2017-12-01

    As a new family member of room-temperature aprotic metal-O 2 batteries, Na-O 2 batteries, are attracting growing attention because of their relatively high theoretical specific energy and particularly their uncompromised round-trip efficiency. Here, a hierarchical porous carbon sphere (PCS) electrode that has outstanding properties to realize Na-O 2 batteries with excellent electrochemical performances is reported. The controlled porosity of the PCS electrode, with macropores formed between PCSs and nanopores inside each PCS, enables effective formation/decomposition of NaO 2 by facilitating the electrolyte impregnation and oxygen diffusion to the inner part of the oxygen electrode. In addition, the discharge product of NaO 2 is deposited on the surface of individual PCSs with an unusual conformal film-like morphology, which can be more easily decomposed than the commonly observed microsized NaO 2 cubes in Na-O 2 batteries. A combination of coulometry, X-ray diffraction, and in situ differential electrochemical mass spectrometry provides compelling evidence that the operation of the PCS-based Na-O 2 battery is underpinned by the formation and decomposition of NaO 2 . This work demonstrates that employing nanostructured carbon materials to control the porosity, pore-size distribution of the oxygen electrodes, and the morphology of the discharged NaO 2 is a promising strategy to develop high-performance Na-O 2 batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Empirical seasonal forecasts of the NAO

    Science.gov (United States)

    Sanchezgomez, E.; Ortizbevia, M.

    2003-04-01

    We present here seasonal forecasts of the North Atlantic Oscillation (NAO) issued from ocean predictors with an empirical procedure. The Singular Values Decomposition (SVD) of the cross-correlation matrix between predictor and predictand fields at the lag used for the forecast lead is at the core of the empirical model. The main predictor field are sea surface temperature anomalies, although sea ice cover anomalies are also used. Forecasts are issued in probabilistic form. The model is an improvement over a previous version (1), where Sea Level Pressure Anomalies were first forecast, and the NAO Index built from this forecast field. Both correlation skill between forecast and observed field, and number of forecasts that hit the correct NAO sign, are used to assess the forecast performance , usually above those values found in the case of forecasts issued assuming persistence. For certain seasons and/or leads, values of the skill are above the .7 usefulness treshold. References (1) SanchezGomez, E. and Ortiz Bevia M., 2002, Estimacion de la evolucion pluviometrica de la Espana Seca atendiendo a diversos pronosticos empiricos de la NAO, in 'El Agua y el Clima', Publicaciones de la AEC, Serie A, N 3, pp 63-73, Palma de Mallorca, Spain

  11. Changes of interannual NAO variability in response to greenhouse gases forcing

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Buwen; Sutton, Rowan T.; Woollings, Tim [University of Reading, National Centre for Atmospheric Science, Department of Meteorology, Reading (United Kingdom)

    2011-10-15

    Observations show that there was change in interannual North Atlantic Oscillation (NAO) variability in the mid-1970s. This change was characterized by an eastward shift of the NAO action centres, a poleward shift of zonal wind anomalies and a downstream extension of climate anomalies associated with the NAO. The NAO interannual variability for the period after the mid-1970s has an annular mode structure that penetrates deeply into the stratosphere, indicating a strengthened relationship between the NAO and the Arctic Oscillation (AO) and strengthened stratosphere-troposphere coupling. In this study we have investigated possible causes of these changes in the NAO by carrying out experiments with an atmospheric GCM. The model is forced either by doubling CO{sub 2}, or increasing sea surface temperatures (SST), or both. In the case of SST forcing the SST anomaly is derived from a coupled model simulation forced by increasing CO{sub 2}. Results indicate that SST and CO{sub 2} change both force a poleward and eastward shift in the pattern of interannual NAO variability and the associated poleward shift of zonal wind anomalies, similar to the observations. The effect of SST change can be understood in terms of mean changes in the troposphere. The direct effect of CO{sub 2} change, in contrast, can not be understood in terms of mean changes in the troposphere. However, there is a significant response in the stratosphere, characterized by a strengthened climatological polar vortex with strongly enhanced interannual variability. In this case, the NAO interannual variability has a strong link with the variability over the North Pacific, as in the annular AO pattern, and is also strongly related to the stratospheric vortex, indicating strengthened stratosphere-troposphere coupling. The similarity of changes in many characteristics of NAO interannual variability between the model response to doubling CO{sub 2} and those in observations in the mid-1970s implies that the

  12. A robust empirical seasonal prediction of winter NAO and surface climate.

    Science.gov (United States)

    Wang, L; Ting, M; Kushner, P J

    2017-03-21

    A key determinant of winter weather and climate in Europe and North America is the North Atlantic Oscillation (NAO), the dominant mode of atmospheric variability in the Atlantic domain. Skilful seasonal forecasting of the surface climate in both Europe and North America is reflected largely in how accurately models can predict the NAO. Most dynamical models, however, have limited skill in seasonal forecasts of the winter NAO. A new empirical model is proposed for the seasonal forecast of the winter NAO that exhibits higher skill than current dynamical models. The empirical model provides robust and skilful prediction of the December-January-February (DJF) mean NAO index using a multiple linear regression (MLR) technique with autumn conditions of sea-ice concentration, stratospheric circulation, and sea-surface temperature. The predictability is, for the most part, derived from the relatively long persistence of sea ice in the autumn. The lower stratospheric circulation and sea-surface temperature appear to play more indirect roles through a series of feedbacks among systems driving NAO evolution. This MLR model also provides skilful seasonal outlooks of winter surface temperature and precipitation over many regions of Eurasia and eastern North America.

  13. Estrategia Naos :

    OpenAIRE

    Pérez Sánchez, Ana Belén

    2015-01-01

    En el año 2005 se puso en marcha la Estrategia NAOS ( Estrategia para la Nutrición, Actividad Física y Prevención de la Obesidad) desde el Ministerio de Sanidad y consumo, a través de la Agencia Española de Seguridad Alimentaria y Nutrición, con el objetivo de sensibilizar a la población del problema que la obesidad representa para la salud y de impulsar todas las iniciativas que contribuyan a lograr que los ciudadanos, especialmente niños y jóvenes, adopten hábitos de v...

  14. Study for increasing the stabilization time of a catalytic dye to facilitate the fabrication of membrane electrode assemblies; Estudio para incrementar el tiempo de estabilizacion de una tinta catalitica para facilitar la fabricacion de ensambles membrana-electrodo

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Martinez Vado, F. Isaias [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico); Cano Castillo, Ulises, Albarran Sanchez, Lorena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

    2009-09-15

    An infrastructure project has been underway for hydrogen technology and fuel cells at the Electrical Research Institute (IIE, Spanish acronym). Part of this project is an activity for the fabrication of membrane electrode assemblies (MEA). Currently, a fabrication process is well-established for the MEA using the spray technique. In addition, a catalytic dye base composition has been developed for use in the fabrication of high-quality MEA with a good degree of reproducibility. Nevertheless, the instability of the dye over time prevents continuous fabrication of MEA. This document presents the results obtained, to-date, of research conducted at the IIE aimed at increasing the stability of the catalytic dye by adding a surfactant with different concentrations and increasing the concentration of the Nafion® solution. It was found that the effect of adding the surfactant to the catalytic dye results in a qualitative decrease in the agglomerate sizes, while also decreasing the porosity of the dye once it has dried. In addition, it was found that increasing the amount of Nafion® in the catalytic die increases the porosity. [Spanish] En el Instituto de Investigaciones Electricas (IIE) se ha venido trabajando en un proyecto de infraestructura sobre la tecnologia de hidrogeno y celdas de combustible. Dentro de este proyecto se tiene una actividad orientada a la fabricacion de Ensambles Membrana-Electrodo (MEA's). Actualmente se tiene un proceso de fabricacion bien establecido para la elaboracion de MEA's utilizando la tecnica de rociado, asimismo, se tiene una composicion base de tinta catalitica con la cual se fabrican MEA's de buena calidad y con buen grado de reproducibilidad. Sin embargo, la inestabilidad de la tinta con respecto al tiempo impide tener una fabricacion continua de los MEA's. En este documento se presentan los resultados obtenidos hasta ahora de una investigacion que se realiza en el IIE orientada a incrementar la estabilidad de la

  15. Robot NAO cantante

    OpenAIRE

    Caballero Pamos, Adrián

    2016-01-01

    En los últimos años la robótica ha experimentado un crecimiento exponencial incorporando todo tipo de funcionalidades. Introducir el mundo musical en los robots es una de ellas. En este Trabajo Fin de Grado se presenta el desarrollo de un sistema que permite al robot NAO leer una partitura, analizarla y reproducirla a modo de canto. La finalidad del trabajo es que el robot actúe como un intérprete frente a una partitura musical tal y como lo haría un humano. Debe ser capaz de interpretar cual...

  16. Modification of porosity in the catalyst layer of membrane electrode assemblies using pore-forming agents; Modificacion de la porosidad en la capa catalitica de ensambles membrana-electrodo empleando agentes formadores de poros

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Reyes, Brenda [UNAM. Facultad de Quimica, Mexico D.F. (Mexico); Barbosa P., Romeli [Centro de Investigacion en Energia, UNAM, Temixco, Morelos (Mexico); Cano Castillo, Ulises; Albarran, Lorena [Instituto de Investigaciones Electricas Cuernavaca, Morelos (Mexico)

    2009-09-15

    Membrane electrode assemblies (MEA) are the most important part of PEM fuel cells since their interface results in the electrochemical reactions that make the generation of electricity possible. The MEA is composed of a proton exchange membrane, both sides of which are impregnated with a catalyst layer, normally of carbon-supported platinum. Depending on the technique used for its fabrication (atomization, serigraphy, brush methods, chemical reduction, etc.), the properties of the MEA can be different in terms of porosity, distribution of the catalyst, thickness and structure of the catalyst layer, and the quality of the union between the catalyst layer and the membrane, etc. Currently, the porosity of the electrodes is generated by isopropanol evaporation (solvent used in the dye) during the fabrication process conducted in the Instituto de Investigaciones Electricas (IIE). This document presents the results obtained from adding a porous agent to the catalytic dye base composition used in the fabrication of MEA at the IIE. [Spanish] Los Ensambles Membrana-Electrodo (MEA's) son la parte mas importante en las celdas de combustibles tipo PEM, ya que en su interfaz se llevan a cabo las reacciones electroquimicas que hacen posible la generacion de electricidad. El MEA esta compuesto de una membrana de intercambio protonico a la cual se le impregna en ambos lados una capa catalitica normalmente de platino soportado en carbon. Dependiendo de la tecnica empleada en su fabricacion (atomizado, serigrafia, brocha, reduccion quimica, etc.), las propiedades del MEA pueden ser diferentes en cuanto a porosidad, distribucion del catalizador, grosor y estructura de la capa catalitica, asi como la calidad de la union entre la capa catalizadora y la membrana, etc. Actualmente, la porosidad de los electrodos es generada por la evaporacion del isopropanol (solvente utilizado en la tinta) durante el proceso de fabricacion que se realiza en el Instituto de Investigaciones

  17. Impacts of the EA and SCA patterns on the 20th century NAO-winter precipitation relationship in Europe

    Science.gov (United States)

    Comas-Bru, Laia; McDermott, Frank

    2013-04-01

    Much of the 20th century multi-decadal variability in the NAO-winter precipitation relationship over the N. Atlantic / European sector can be ascribed to the combined effects of the North Atlantic Oscillation (NAO) and either the East Atlantic pattern (EA) or the Scandinavian pattern (SCA). The NAO, EA and SCA indices employed here are defined as the three leading vectors of the cross-correlation matrix calculated from monthly sea-level pressure anomalies for 138 complete winters from the 20CRv2 dataset (Compo et al., 2011). Winter precipitation data over Europe for the entire 20th century is derived from the high resolution CRU-TS3.1 climate dataset (Mitchell and Jones, 2005). Here we document for the first time, that different NAO/EA and NAO/SCA combinations systematically influence winter precipitation conditions in Europe as a consequence of NAO dipole migrations. We find that the zero-correlated line of the NAO-winter precipitation relationship migrates southwards when the EA is in the opposite phase to the NAO. This can be related to a south-westwards migration of the NAO dipole under these conditions, as shown by teleconnectivity maps. Similarly, a clockwise movement of the NAO-winter climate correlated areas occurs when the phase of the SCA is opposite to that of the NAO, reflecting a clockwise movement of the NAO dipole under these conditions. An important implication of these migrations is that they influence the spatial and temporal stationarity of climate-NAO relationships. As a result, the link between winter precipitation patterns and the NAO is not straightforward in some regions such as the southern UK, Ireland and France. For instance, much of the inter-annual variability in the N-S winter precipitation gradient in the UK, originally attributed to inter-annual and inter-decadal variability of the NAO, reflects the migration of the NAO dipole, linked to linear combinations of the NAO and the EA. Our results indicate that when the N-S winter

  18. Influences of North Atlantic Oscillation (NAO) on warm season temperature and crop yields in the southwestern US

    Science.gov (United States)

    Myoung, B.; Kim, S.; Kim, J.; Kafatos, M.

    2013-12-01

    Despite advancements in agricultural technology, agricultural productivity remains vulnerable to extreme meteorological conditions. This study has found significant impacts of North Atlantic Oscillation (NAO) on extreme temperatures and in turn on crop yields in the Southwestern United States (SW US) region. Analyses of multi-year data of observed temperatures and simulated maize yields reveal that NAO affects positively the daily temperature maxima and minima in the green-up periods (March-June) and that the response of maize yields to NAO varies according to the climatological mean temperatures. In warmer regions, a combination of above-normal NAO in the planting periods and below-normal NAO in the growing periods is favorable for high maize yields by reducing extremely cold days during the planting periods and extremely hot days in the later periods, respectively. In colder regions, continuously above-normal NAO conditions favor higher yields via above normal thermal conditions. Results in this study suggest that NAO predictions can benefit agricultural planning in SW US.

  19. Sharpest Ever VLT Images at NAOS-CONICA "First Light"

    Science.gov (United States)

    2001-12-01

    Very Promising Start-Up of New Adaptive Optics Instrument at Paranal Summary A team of astronomers and engineers from French and German research institutes and ESO at the Paranal Observatory is celebrating the successful accomplishment of "First Light" for the NAOS-CONICA Adaptive Optics facility . With this event, another important milestone for the Very Large Telescope (VLT) project has been passed. Normally, the achievable image sharpness of a ground-based telescope is limited by the effect of atmospheric turbulence. However, with the Adaptive Optics (AO) technique, this drawback can be overcome and the telescope produces images that are at the theoretical limit, i.e., as sharp as if it were in space . Adaptive Optics works by means of a computer-controlled, flexible mirror that counteracts the image distortion induced by atmospheric turbulence in real time. The larger the main mirror of the telescope is, and the shorter the wavelength of the observed light, the sharper will be the images recorded. During a preceding four-week period of hard and concentrated work, the expert team assembled and installed this major astronomical instrument at the 8.2-m VLT YEPUN Unit Telescope (UT4). On November 25, 2001, following careful adjustments of this complex apparatus, a steady stream of photons from a southern star bounced off the computer-controlled deformable mirror inside NAOS and proceeded to form in CONICA the sharpest image produced so far by one of the VLT telescopes. With a core angular diameter of only 0.07 arcsec, this image is near the theoretical limit possible for a telescope of this size and at the infrared wavelength used for this demonstration (the K-band at 2.2 µm). Subsequent tests reached the spectacular performance of 0.04 arcsec in the J-band (wavelength 1.2 µm). "I am proud of this impressive achievement", says ESO Director General Catherine Cesarsky. "It shows the true potential of European science and technology and it provides a fine

  20. Correlation between sea surface temperature and wind speed in Greenland Sea and their relationships with NAO variability

    Directory of Open Access Journals (Sweden)

    Bo Qu

    2012-09-01

    Full Text Available The North Atlantic Oscillation (NAO is one of the major causes of many recent changes in the Arctic Ocean. Generally, it is related to wind speed, sea surface temperature (SST, and sea ice cover. In this study, we analyzed the distributions of and correlations between SST, wind speed, NAO, and sea ice cover from 2003 to 2009 in the Greenland Sea at 10°W to 10°E, 65°N to 80°N. SST reached its peak in July, while wind speed reached its minimum in July. Seasonal variability of SST and wind speed was different for different regions. SST and wind speed mainly had negative correlations. Detailed correlation research was focused on the 75°N to 80°N band. Regression analysis shows that in this band, the variation of SST lagged three months behind that of wind speed. Ice cover and NAO had a positive correlation, and the correlation coefficient between ice cover and NAO in the year 2007 was 0.61. SST and NAO also had a positive correlation, and SST influenced NAO one month in advance. The correlation coefficients between SST and NAO reached 0.944 for the year 2005, 0.7 for the year 2008, and 0.74 for the year 2009 after shifting SST one month later. NAO also had a positive correlation with wind speed, and it also influenced wind speed one month in advance. The correlation coefficients between NAO and wind speed reached 0.783, 0.813, and 0.818 for the years 2004, 2005, and 2008, respectively, after shifting wind speed one month earlier.

  1. Effect of Qing Nao tablet on blood stasis model of mice

    Science.gov (United States)

    Kong, Xuejun; Hao, Shaojun; Wang, Hongyu; Liu, Xiaobin; Xie, Guoqi; Li, Wenjun; Zhang, Zhengchen

    2018-04-01

    To investigate the effect of Qing Nao tablet on mouse model of blood stasis syndrome, 60 mice, male and female, were randomly divided into 6 groups, were fed with large, small doses of Qing Nao tablet suspension, Naoluotong saline suspension and the same volume (group 2, 0.1ml/10g), administer 1 times daily, orally for 15 days. Intragastric administration for first days, in addition to the 1 group saline group every day in the hind leg intramuscular saline, the other 5 groups each rat day hind leg muscle injection of dexamethasone 0.8mg/kg intramuscular injection every day, 1 times, 15 days. 1 hour continuous intramuscular injection and intramuscular drug perfusion on the sixteenth day after mice. The eyeball blood, heparin after whole blood viscosity test. Compared with the control group, model group, high and low shear viscosity were significantly increased (Pgroup, high dose group and Qing Nao tablet Naoluotong group can significantly reduce the viscosity at high shear and (Pgroup can significantly reduce high shear and shear viscosity (Pgroup can significantly reduce the low shear viscosity (Pgroup can significantly reduce the low shear viscosity (Pgroup were lower high cut, low shear viscosity and trend The potential (P>0.05). The Qing Nao tablet has a good effect on the model of blood stasis in mice.

  2. Characterization of Bacillus subtilis strains in Thua nao, a traditional fermented soybean food in northern Thailand.

    Science.gov (United States)

    Inatsu, Y; Nakamura, N; Yuriko, Y; Fushimi, T; Watanasiritum, L; Kawamoto, S

    2006-09-01

    To clarify the diversity of Bacillus subtilis strains in Thua nao that produce high concentrations of products useful in food manufacturing and in health-promoting compounds. Production of amylase, protease, subtilisin NAT (nattokinase), and gamma-polyglutamic acid (PGA) by the Bacillus subtilis strains in Thua nao was measured. Productivity of protease NAT by these strains tended to be higher than by Japanese commercial natto-producing strains. Molecular diversity of isolated strains was analysed via randomly amplified polymorphic DNA-PCR fingerprinting. The strains were divided into 19 types, including a type with the same pattern as a Japanese natto-producing strain. B. subtilis strains that could be a resource for effective production of protease, amylase, subtilisin NAT, or PGA were evident in Thua nao produced in various regions in northern Thailand. This study clearly demonstrated the value of Thua nao as a potential resource of food-processing enzymes and health-promoting compounds.

  3. European land CO2 sink influenced by NAO and East-Atlantic Pattern coupling

    Science.gov (United States)

    Bastos, Ana; Janssens, Ivan A.; Gouveia, Célia M.; Trigo, Ricardo M.; Ciais, Philippe; Chevallier, Frédéric; Peñuelas, Josep; Rödenbeck, Christian; Piao, Shilong; Friedlingstein, Pierre; Running, Steven W.

    2016-01-01

    Large-scale climate patterns control variability in the global carbon sink. In Europe, the North-Atlantic Oscillation (NAO) influences vegetation activity, however the East-Atlantic (EA) pattern is known to modulate NAO strength and location. Using observation-driven and modelled data sets, we show that multi-annual variability patterns of European Net Biome Productivity (NBP) are linked to anomalies in heat and water transport controlled by the NAO–EA interplay. Enhanced NBP occurs when NAO and EA are both in negative phase, associated with cool summers with wet soils which enhance photosynthesis. During anti-phase periods, NBP is reduced through distinct impacts of climate anomalies in photosynthesis and respiration. The predominance of anti-phase years in the early 2000s may explain the European-wide reduction of carbon uptake during this period, reported in previous studies. Results show that improving the capability of simulating atmospheric circulation patterns may better constrain regional carbon sink variability in coupled carbon-climate models. PMID:26777730

  4. Technological fantasies of Nao

    DEFF Research Database (Denmark)

    Jørgensen, Stina Marie Hasse; Tafdrup, Oliver Alexander

    2017-01-01

    This article will through a ‘what-if’ scenario involving the humanoid robot, Nao, as a museum guide, discuss the potential benefits of theorizing social robots through a perspective grounded in critical design and postphenomenology. Within Science and Technology-studies (STS) postphenomenology has...... been the ‘go-to’ theory when discussing the philosophical aspects of human-technology relations. Postphenomenology directly addresses how humans on a phenomenological level relate to robots through an ‘alterity-relation’ that establishes the robot as a ‘quasi-other’. A methodological discussion of how...... to conduct empirical postphenomenological research into robotics, has, however, not been thoroughly unfolded, although the question of a general postphenomenological methodology has been touched upon. This article provides a contribution to the debate on how to enquire into human-robot relations...

  5. Tropical Pacific forcing on decadal-to-centennial NAO-dominated precipitation variability in northern Mediterranean over the past 6500 years

    Science.gov (United States)

    Hu, H. M.; Shen, C. C.; Michel, V.; Jiang, X.; Mii, H. S.; Wang, Y.; Valensi, P.

    2017-12-01

    We present a multi-annual-resolved absolute-dated stalagmite-inferred precipitation record, with age precision as good as ±2 years, from northern Italy, to reflect North Atlantic Oscillation (NAO) dynamics since 6.5 ka (thousand years ago, before 1950 C.E.). Our record features millennial precipitation fluctuations punctuated by several centennial-scale drought periods centered at 5.6, 6.2, 4.2, 3.0 and 2.3 ka. The phase relationship with previous NAO-sensitive records suggests a multi-millennial southward migration of the northern Westerlies and enhanced NAO variability from the middle- to late-Holocene. We also found the multi-decadal to centennial rainfall amount could dramatically vary within few decades, possibly affecting ancient Mediterranean civilizations. Concurrence between northern Mediterranean precipitation and western tropical Pacific sea surface temperature records suggests the remote forcing on this NAO-dominated rainfall. We argue that the irregular NAO change nowadays could be related to high frequency of El Niño-Southern Oscillation events and might cause an inevitable abrupt hydroclimate change and irreparable impacts on the regional human society in the near future.

  6. Understanding the NAO from Iberian and UK paleoclimate records. The NAOSIPUK project

    Science.gov (United States)

    Garcia-Alix, Antonio; Toney, Jaime L.; Jiménez-Moreno, Gonzalo; Slaymark, Charlotte; José Ramos-Román, Maria; Camuera, Jon; Jiménez-Espejo, Francisco J.; Anderson, R. Scott

    2017-04-01

    The main goal of the NAOSIPUK project was to understand the North Atlantic Oscillation (NAO) during the Holocene, because the NAO is one major climate mode influencing climate patterns across Europe, and therefore, economy and society (Hurrell, 1995). We analysed several sedimentary records in two regions with opposing NAO responses. Our sedimentary surface survey from numerous lakes and bogs, led to further investigation of four records in the southern Iberian Peninsula and three in the central/northern UK. Past environments of the different sites were analysed using pollen and charcoal analysis, organic and inorganic geochemistry analyses, and sedimentary and geophysical surveys were performed. This work compares general environmental trends in both regions as deduced from the organic matter from bulk sediment to get an idea of the organic matter source, as well as specific organic compounds extracted from the sediment, such as leaf waxes (n-alkanes), algae-related compounds (diols and alkenones), and bacteria-related compounds (hopanes), to specify the sources of the organic matter, environmental temperature ranges, as well as hydrological changes. Our preliminary results show that the palaeoenvironmental indices developed from n-alkanes agree with the variations deduced from the carbon and nitrogen atomic ratios, as well as the carbon isotopic composition from bulk sediments in southern Iberia records. Interestingly, these indices show that some locations display opposite trends from one another, and are used to distinguish regional versus local effects of climate change, human impacts, and aeolian dust inputs. During the late Holocene solar forcing and NAO fluctuations are the main drivers of the environmental evolution in most of the Iberian and UK sites. However, we do detect the influence of the NAO in the temperatures oscillations of the studied sites in southern Iberia. This influence is much more important in the north/central UK sites. The regional

  7. Climate Prediction Center (CPC) Monthly North Atlantic Oscillation (NAO) teleconnection index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly tabulated index of the North Atlantic Oscillation (NAO) teleconnection pattern. The data spans the period 1950 to present. The index is derived from a...

  8. New Insights into the Instability of Discharge Products in Na-O2 Batteries.

    Science.gov (United States)

    Landa-Medrano, Imanol; Pinedo, Ricardo; Bi, Xuanxuan; Ruiz de Larramendi, Idoia; Lezama, Luis; Janek, Jürgen; Amine, Khalil; Lu, Jun; Rojo, Teófilo

    2016-08-10

    Sodium-oxygen batteries currently stimulate extensive research due to their high theoretical energy density and improved operational stability when compared to lithium-oxygen batteries. Cell stability, however, needs to be demonstrated also under resting conditions before future implementation of these batteries. In this work we analyze the effect of resting periods on the stability of the sodium superoxide (NaO2) discharge product. The instability of NaO2 in the cell environment is demonstrated leading to the evolution of oxygen during the resting period and the decrease of the cell efficiency. In addition, migration of the superoxide anion (O2(-)) in the electrolyte is observed and demonstrated to be an important factor affecting Coulombic efficiency.

  9. Pharmacokinetics and efficiency of brain targeting of ginsenosides Rg1 and Rb1 given as Nao-Qing microemulsion.

    Science.gov (United States)

    Li, Tao; Shu, Ya-Jun; Cheng, Jia-Yin; Liang, Run-Cheng; Dian, Shao-Na; Lv, Xiao-Xun; Yang, Meng-Qi; Huang, Shu-Ling; Chen, Gang; Yang, Fan

    2015-02-01

    Nao-Qing solution has been shown to be clinically effective in the treatment of acute ischemic stroke (AIS). The purpose of this study was to improve the pharmacokinetics and brain uptake of Nao-Qing, administered as an oil-in-water microemulsion. Sprague-Dawley (SD) rats were given Nao-Qing microemulsion by intranasal or intragastric routes. Samples of blood, brain, heart, liver, lung and kidney were collected at pre-determined time intervals, and the contents of ginsenosides Rg1 and Rb1 (active ingredients of the Nao-Qing microemulsion) were analyzed by high-performance liquid chromatography (HPLC). The results showed that contents of ginsenosides Rg1 and Rb1 in Nao-Qing microemulsion was 8475.13 ± 54.61 μg/ml and 6633.42 ± 527.27 μg/ml, respectively, and that the particle size, pH and viscosity of the microemulsion were 19.9 ± 5.07 nm, 6.1 and 3.056 × 10(-3 )Pas, respectively. Absorption of ginsenoside Rg1 was higher than that of ginsenoside Rb1, which was barely detectable after intragastric administration; furthermore, the concentration of ginsenoside Rg1 in blood and other tissues at each time point was lower for intragastric than for intranasal administration. Compared with intragastric administration, intranasal administration resulted in a shorter tmax (0.08 versus 1 h), a higher Cmax (16.65 versus 11.29 μg/ml), and a higher area under the concentration-time curve (AUC) (592.91 versus 101.70 μgċh/ml) in the brain. The relative rates of uptake (Re) and the ratio of peak concentration (Ce) in the brain were 126.31% and 147.48% for ginsenoside Rg1, respectively. These data illustrate that intranasal administration can promote the absorption of drugs in Nao-Qing microemulsion and achieve fast effect.

  10. The influences of the AMO and NAO on an Iberian alpine lake during the Late Holocene

    Science.gov (United States)

    Hernández, Armand; Leira, Manel; Trigo, Ricardo; Vázquez-Loureiro, David; Carballeira, Rafael; Sáez, Alberto

    2017-04-01

    High mountain lakes, usually oligotrophic, in the Iberian Peninsula are particularly sensitive to the influence of North Atlantic large-scale modes of climate variability due to their geographical position and the reduced direct anthropic disturbances. In this context, Serra da Estrela (Portugal), in the westernmost of the Sistema Central Range, constitutes a physical barrier to air masses coming from the Atlantic Ocean. However, long-term climate reconstructions have not yet been conducted. We present a climate reconstruction in terms of precipitation and temperature changes of this setting based on facies analysis, X-ray fluorescence core scanning, elemental and isotope geochemistry on bulk organic matter and a preliminary study of diatom assemblages from the sedimentary record of Lake Peixão (1677 m a.s.l.; Serra da Estrela) for the last ca. 3500 years. A multivariate statistical analysis has been performed to recognize the main environmental factors controlling the lake sedimentation. Our results reveal that two main processes explain 70% of the total variance, with PC1 (accumulation of siliciclastic material vs organic matter), and PC2 (variations in lacustrine productivity, related to nutrient inputs from the catchment), explaining 53% and 17% respectively. In mountain lakes, siliciclastic and/or external organic matter accumulation tend to be governed by the snowmelt which, in turn, are frequently controlled by winter and spring temperatures. On the other hand, lake productivity, usually limited by phosphorus and nitrogen, is dependent of internal recycling and/or external inputs, mainly by catchment leaching (climatically driven by summer precipitation) and atmospheric deposition (anthropic influence). The results from Lake Peixão have been compared to other Western Iberia and Northeastern Atlantic records, as well as the Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation (NAO) indices. Thus, a tentative Late Holocene climate

  11. THE UNIQUE Na:O ABUNDANCE DISTRIBUTION IN NGC 6791: THE FIRST OPEN(?) CLUSTER WITH MULTIPLE POPULATIONS

    International Nuclear Information System (INIS)

    Geisler, D.; Villanova, S.; Cummings, J.; Carraro, G.; Pilachowski, C.; Johnson, C. I.; Bresolin, F.

    2012-01-01

    Almost all globular clusters investigated exhibit a spread in their light element abundances, the most studied being an Na:O anticorrelation. In contrast, open clusters show a homogeneous composition and are still regarded as Simple Stellar Populations. The most probable reason for this difference is that globulars had an initial mass high enough to retain primordial gas and ejecta from the first stellar generation and thus formed a second generation with a distinct composition, an initial mass exceeding that of open clusters. NGC 6791 is a massive open cluster and warrants a detailed search for chemical inhomogeneities. We collected high-resolution, high signal-to-noise spectra of 21 members covering a wide range of evolutionary status and measured their Na, O, and Fe content. We found [Fe/H] = +0.42 ± 0.01, in good agreement with previous values, and no evidence for a spread. However, the Na:O distribution is completely unprecedented. It becomes the first open cluster to show intrinsic abundance variations that cannot be explained by mixing, and thus the first discovered to host multiple populations. It is also the first star cluster to exhibit two subpopulations in the Na:O diagram with one being chemically homogeneous while the second has an intrinsic spread that follows the anticorrelation so far displayed only by globular clusters. NGC 6791 is unique in many aspects, displaying certain characteristics typical of open clusters, others more reminiscent of globulars, and yet others, in particular its Na:O behavior investigated here, that are totally unprecedented. It clearly had a complex and fascinating history.

  12. The Unique Na:O Abundance Distribution in NGC 6791: The First Open(?) Cluster with Multiple Populations

    Science.gov (United States)

    Geisler, D.; Villanova, S.; Carraro, G.; Pilachowski, C.; Cummings, J.; Johnson, C. I.; Bresolin, F.

    2012-09-01

    Almost all globular clusters investigated exhibit a spread in their light element abundances, the most studied being an Na:O anticorrelation. In contrast, open clusters show a homogeneous composition and are still regarded as Simple Stellar Populations. The most probable reason for this difference is that globulars had an initial mass high enough to retain primordial gas and ejecta from the first stellar generation and thus formed a second generation with a distinct composition, an initial mass exceeding that of open clusters. NGC 6791 is a massive open cluster and warrants a detailed search for chemical inhomogeneities. We collected high-resolution, high signal-to-noise spectra of 21 members covering a wide range of evolutionary status and measured their Na, O, and Fe content. We found [Fe/H] = +0.42 ± 0.01, in good agreement with previous values, and no evidence for a spread. However, the Na:O distribution is completely unprecedented. It becomes the first open cluster to show intrinsic abundance variations that cannot be explained by mixing, and thus the first discovered to host multiple populations. It is also the first star cluster to exhibit two subpopulations in the Na:O diagram with one being chemically homogeneous while the second has an intrinsic spread that follows the anticorrelation so far displayed only by globular clusters. NGC 6791 is unique in many aspects, displaying certain characteristics typical of open clusters, others more reminiscent of globulars, and yet others, in particular its Na:O behavior investigated here, that are totally unprecedented. It clearly had a complex and fascinating history.

  13. Communication Framework For the Mionix Naos QG Mouse

    DEFF Research Database (Denmark)

    Wulff-Jensen, Andreas

    2017-01-01

    The Mionix Naos QG mouse has multiple sensors integrated. It can record all the metrics native to mice: being scroll, clicks and mouse movements. Moreover, this mouse has heart rate (HR) and Galvanic Skin Response (GSR) sensors embedded. Through Mionics API [1] WebSocket can be used to access all...... or be recorded. Another Unity implementation have been developed as well. This was directly connected to the WebSocket, and has the same properties as the first Unity development. Since two nearly identical implementations were made, the quality of their recordings and data communication were tested. Based...

  14. Serial clustering of extratropical cyclones and relationship with NAO and jet intensity based on the IMILAST cyclone database

    Science.gov (United States)

    Ulbrich, Sven; Pinto, Joaquim G.; Economou, Theodoros; Stephenson, David B.; Karremann, Melanie K.; Shaffrey, Len C.

    2017-04-01

    Cyclone families are a frequent synoptic weather feature in the Euro-Atlantic area, particularly during wintertime. Given appropriate large-scale conditions, such series (clusters) of storms may cause large socio-economic impacts and cumulative losses. Recent studies analyzing reanalysis data using single cyclone tracking methods have shown that serial clustering of cyclones occurs on both flanks and downstream regions of the North Atlantic storm track. Based on winter (DJF) cyclone counts from the IMILAST cyclone database, we explore the representation of serial clustering in the ERA-Interim period and its relationship with the NAO-phase and jet intensity. With this aim, clustering is estimated by the dispersion of winter (DJF) cyclone passages for each grid point over the Euro-Atlantic area. Results indicate that clustering over the Eastern North Atlantic and Western Europe can be identified for all methods, although the exact location and the dispersion magnitude may vary. The relationship between clustering and (i) the NAO-phase and (ii) jet intensity over the North Atlantic is statistically evaluated. Results show that the NAO-index and the jet intensity show a strong contribution to clustering, even though some spread is found between methods. We conclude that the general features of clustering of extratropical cyclones over the North Atlantic and Western Europe are robust to the choice of tracking method. The same is true for the influence of the NAO and jet intensity on cyclone dispersion.

  15. Nitric acid oxidation of Si (NAOS) method for low temperature fabrication of SiO{sub 2}/Si and SiO{sub 2}/SiC structures

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, H., E-mail: koba771@ybb.ne.jp [Institute of Scientific and Industrial Research, Osaka University, and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Imamura, K.; Kim, W.-B.; Im, S.-S.; Asuha [Institute of Scientific and Industrial Research, Osaka University, and CREST, Japan Science and Technology Agency, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan)

    2010-07-15

    We have developed low temperature formation methods of SiO{sub 2}/Si and SiO{sub 2}/SiC structures by use of nitric acid, i.e., nitric acid oxidation of Si (or SiC) (NAOS) methods. By use of the azeotropic NAOS method (i.e., immersion in 68 wt% HNO{sub 3} aqueous solutions at 120 deg. C), an ultrathin (i.e., 1.3-1.4 nm) SiO{sub 2} layer with a low leakage current density can be formed on Si. The leakage current density can be further decreased by post-metallization anneal (PMA) at 200 deg. C in hydrogen atmosphere, and consequently the leakage current density at the gate bias voltage of 1 V becomes 1/4-1/20 of that of an ultrathin (i.e., 1.5 nm) thermal oxide layer usually formed at temperatures between 800 and 900 deg. C. The low leakage current density is attributable to (i) low interface state density, (ii) low SiO{sub 2} gap-state density, and (iii) high band discontinuity energy at the SiO{sub 2}/Si interface arising from the high atomic density of the NAOS SiO{sub 2} layer. For the formation of a relatively thick (i.e., {>=}10 nm) SiO{sub 2} layer, we have developed the two-step NAOS method in which the initial and subsequent oxidation is performed by immersion in {approx}40 wt% HNO{sub 3} and azeotropic HNO{sub 3} aqueous solutions, respectively. In this case, the SiO{sub 2} formation rate does not depend on the Si surface orientation. Using the two-step NAOS method, a uniform thickness SiO{sub 2} layer can be formed even on the rough surface of poly-crystalline Si thin films. The atomic density of the two-step NAOS SiO{sub 2} layer is slightly higher than that for thermal oxide. When PMA at 250 deg. C in hydrogen is performed on the two-step NAOS SiO{sub 2} layer, the current-voltage and capacitance-voltage characteristics become as good as those for thermal oxide formed at 900 deg. C. A relatively thick (i.e., {>=}10 nm) SiO{sub 2} layer can also be formed on SiC at 120 deg. C by use of the two-step NAOS method. With no treatment before the NAOS method

  16. Tema 2: The NAO robot as a Persuasive Educational and Entertainment Robot (PEER – a case study on children’s articulation, categorization and interaction with a social robot for learning

    Directory of Open Access Journals (Sweden)

    Lykke Brogaard Bertel

    2016-01-01

    Full Text Available The application of social robots as motivational tools and companions in education is increasingly being explored from a theoretical and practical point of view. In this paper, we examine the social robot NAO as a Persuasive Educational and Entertainment Robot (PEER and present findings from a case study on the use of NAO to support learning environments in Danish primary schools. In the case study we focus on the children’s practice of articulation and embodied interaction with NAO and investigate the role of NAO as a ‘tool’, ‘social actor’ or ‘simulating medium’ in the learning designs. We examine whether this categorization is static or dynamic, i. e. develops and changes over the course of the interaction and explore how this relates to and affects the student’s motivation to engage in the NAO-supported learning activities.

  17. Tema 2: The NAO robot as a Persuasive Educational and Entertainment Robot (PEER – a case study on children’s articulation, categorization and interaction with a social robot for learning

    Directory of Open Access Journals (Sweden)

    Lykke Brogaard Bertel

    2015-12-01

    Full Text Available The application of social robots as motivational tools and companions in education is increasingly being explored from a theoretical and practical point of view. In this paper, we examine the social robot NAO as a Persuasive Educational and Entertainment Robot (PEER and present findings from a case study on the use of NAO to support learning environments in Danish primary schools. In the case study we focus on the children’s practice of articulation and embodied interaction with NAO and investigate the role of NAO as a ‘tool’, ‘social actor’ or ‘simulating medium’ in the learning designs. We examine whether this categorization is static or dynamic, i. e. develops and changes over the course of the interaction and explore how this relates to and affects the student’s motivation to engage in the NAO-supported learning activities.

  18. Late Holocene forest dynamics in the Gulf of Gaeta (central Mediterranean) in relation to NAO variability and human impact

    Science.gov (United States)

    Di Rita, Federico; Lirer, Fabrizio; Bonomo, Sergio; Cascella, Antonio; Ferraro, Luciana; Florindo, Fabio; Insinga, Donatella Domenica; Lurcock, Pontus Conrad; Margaritelli, Giulia; Petrosino, Paola; Rettori, Roberto; Vallefuoco, Mattia; Magri, Donatella

    2018-01-01

    A new high-resolution pollen record, spanning the last five millennia, is presented from the Gulf of Gaeta (Tyrrhenian Sea, central Italy), with the aim of verifying if any vegetation change occurred in the central Mediterranean region in relation to specific well-known global and/or regional climate events, including the 4.2 ka event, the Medieval Climate Anomaly (MCA) and the Little Ice Age (LIA), and to detect possible vegetation changes related to still under-investigated climate signals, for example the so-called "Bond 2" cold event around 2.8 ka BP. The vegetation dynamics of the Gaeta record shows a recurrent pattern of forest increase and decline punctuating the mid- and late Holocene. When the timing of these patterns is compared with the climate proxy data available from the same core (planktonic foraminifera assemblages and oxygen stable isotope record) and with the NAO (North Atlantic Oscillation) index, it clearly appears that the main driver for the forest fluctuations is climate, which may even overshadow the effects of human activity. We have found a clear correspondence between phases with negative NAO index and forest declines. In particular, around 4200 cal BP, a drop in AP (Arboreal Pollen) confirms the clearance recorded in many sites in Italy south of 43°N. Around 2800 cal BP, a vegetation change towards open conditions is found at a time when the NAO index clearly shows negative values. Between 800 and 1000 AD, a remarkable forest decline, coeval with a decrease in the frequencies of both Castanea and Olea, matches a shift in the oxygen isotope record towards positive values, indicating cooler temperatures, and a negative NAO. Between 1400-1850 AD, in the time period chronologically corresponding to the LIA (Little Ice Age), the Gaeta record shows a clear decline of the forest cover, particularly evident after 1550 AD, once again in correspondence with negative NAO index.

  19. Ultrathin SiO{sub 2} layer formed by the nitric acid oxidation of Si (NAOS) method to improve the thermal-SiO{sub 2}/Si interface for crystalline Si solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Taketoshi; Nakajima, Hiroki; Irishika, Daichi; Nonaka, Takaaki; Imamura, Kentaro; Kobayashi, Hikaru, E-mail: h.kobayashi@sanken.osaka-u.ac.jp

    2017-02-15

    Highlights: • The density of interface states at the SiO{sub 2}/Si interface is decreased by NAOS. • The minority carrier lifetime is increased by the NAOS treatment. • Great interfacial properties of the NAOS layer are kept after thermal oxidation. - Abstract: A combination of the nitric acid oxidation of Si (NAOS) method and post-thermal oxidation is found to efficiently passivate the SiO{sub 2}/n-Si(100) interface. Thermal oxidation at 925 °C and annealing at 450 °C in pure hydrogen atmosphere increases the minority carrier lifetime by three orders of magnitude, and it is attributed to elimination of Si dangling bond interface states. Fabrication of an ultrathin, i.e., 1.1 nm, NAOS SiO{sub 2} layer before thermal oxidation and H{sub 2} annealing further increases the minority carrier lifetime by 30% from 8.6 to 11.1 ms, and decreased the interface state density by 10% from 6.9 × 10{sup 9} to 6.3 × 10{sup 9}eV{sup −1} cm{sup −2}. After thermal oxidation at 800 °C, the SiO{sub 2} layer on the NAOS-SiO{sub 2}/Si(100) structure is 2.26 nm thick, i.e., 0.24 nm thicker than that on the Si(100) surface, while after thermal oxidation at 925 °C, it is 4.2 nm thick, i.e., 0.4 nm thinner than that on Si(100). The chemical stability results from the higher atomic density of a NAOS SiO{sub 2} layer than that of a thermal oxide layer as reported in Ref. [28] (Asuha et al., 2002). Higher minority carrier lifetime in the presence of the NAOS layer indicates that the NAOS-SiO{sub 2}/Si interface with a low interface state density is preserved after thermal oxidation, which supports out-diffusion oxidation mechanism, by which a thermal oxide layer is formed on the NAOS SiO{sub 2} layer.

  20. The Role of the North Atlantic Oscillation (NAO) on Recent Greenland Surface Mass Loss and Mass Partitioning

    Science.gov (United States)

    Tedesco, M.; Alexander, P.; Porter, D. F.; Fettweis, X.; Luthcke, S. B.; Mote, T. L.; Rennermalm, A.; Hanna, E.

    2017-12-01

    Despite recent changes in Greenland surface mass losses and atmospheric circulation over the Arctic, little attention has been given to the potential role of large-scale atmospheric processes on the spatial and temporal variability of mass loss and partitioning of the GrIS mass loss. Using a combination of satellite gravimetry measurements, outputs of the MAR regional climate model and reanalysis data, we show that changes in atmospheric patterns since 2013 over the North Atlantic region of the Arctic (NAA) modulate total mass loss trends over Greenland together with the spatial and temporal distribution of mass loss partitioning. For example, during the 2002 - 2012 period, melting persistently increased, especially along the west coast, as a consequence of increased insulation and negative NAO conditions characterizing that period. Starting in 2013, runoff along the west coast decreased while snowfall increased substantially, when NAO turned to a more neutral/positive state. Modeled surface mass balance terms since 1950 indicate that part of the GRACE-period, specifically the period between 2002 and 2012, was exceptional in terms of snowfall over the east and northeast regions. During that period snowfall trend decreased to almost 0 Gt/yr from a long-term increasing trend, which presumed again in 2013. To identify the potential impact of atmospheric patterns on mass balance and its partitioning, we studied the spatial and temporal correlations between NAO and snowfall/runoff. Our results indicate that the correlation between summer snowfall and NAO is not stable during the 1950 - 2015 period. We further looked at changes in patterns of circulation using self organizing maps (SOMs) to identify the atmospheric patterns characterizing snowfall during different periods. We discuss potential implications for past changes and future GCM and RCM simulations.

  1. Design and Implementation of Autonomous Stair Climbing with Nao Humanoid Robot

    OpenAIRE

    Lu, Wei

    2015-01-01

    With the development of humanoid robots, autonomous stair climbing is an important capability. Humanoid robots will play an important role in helping people tackle some basic problems in the future. The main contribution of this thesis is that the NAO humanoid robot can climb the spiral staircase autonomously. In the vision module, the algorithm of image filtering and detecting the contours of the stair contributes to calculating the location of the stairs accurately. Additionally, the st...

  2. El ciclo anual de la hidrología de Colombia en relación con el ENSO y la NAO

    Directory of Open Access Journals (Sweden)

    1998-01-01

    Full Text Available INFLUENCE DE L’ENSO ET DE LA NAO SUR LE CYCLE ANNUEL DE L’HYDROLOGIE DE COLOMBIE. On évalue l’impact de El Niño-Oscillation du Sud (ENSO et de l’Oscillation de l’Atlantique Nord (NAO sur le cycle annuel hydrologique colombien. Les résultats du Projet de Réanalyse Climatologique NCEP/NCAR ont été utilisés pour identifier les mécanismes de la circulation atmosphérique qui interviennent dans cette région au cours des phases extrêmes de l’ENSO. En particulier, l’affaiblissement du courant jet inférieur d’ouest, qui se propage du Pacifique vers l’intérieur de la Colombie, est l’un des principaux mécanismes de circulation susceptible de nous aider à expliquer les anomalies hydrologiques en situation El Niño. Les résultats confirment l’importance de l’influence de l’ENSO et de la NAO sur les précipitations et les débits de Colombie, en particulier au cours des trimestres de septembre-octobre-novembre et de décembre-janvier-février. Se cuantifica la dependencia del ciclo anual de la hidroclimatología de Colombia con respecto del fenómeno El Niño-Oscilación del Sur (ENSO y la Oscilación del Atlántico Norte (NAO. Se usan los resultados del Proyecto de Reanálisis Climático de NCEP/NCAR para identificar los mecanismos de la circulación involucrados en las anomalías climáticas en la región de Suramérica tropical durante las fases extremas del ENSO (El Niño y La Niña. De particular importancia, el debilitamiento, durante El Niño, de la corriente de chorro superficial del oeste que penetra desde el Océano Pacífico hacia el interior de Colombia es un mecanismo de la circulación que coadyuva para explicar las anomalías hidrológicas. Los resultados confirman la fuerte influencia del ENSO y la NAO sobre las lluvias y los caudales de Colombia, en particular durante los trimestres septiembre-octubre-noviembre y diciembre-enero-febrero. THE ANNUAL CYCLE OF THE HYDROLOGY IN COLOMBIA IN RELATION TO THE ENSO AND NAO

  3. Initial phases of design-based research into the educational potentials of NAO-robots

    DEFF Research Database (Denmark)

    Majgaard, Gunver; Bertel, Lykke Brogaard

    2014-01-01

    In this paper, we describe our initial research, using the humanoid robot NAO in primary and secondary schools. How does a programmable humanoid enrich teaching and how do we prepare the teachers? Ten school classes are using the robot for creative programming. So far we have experienced...... that the robot enriches the learning processes by combining the auditory, visual and kinaesthetic modalities....

  4. Region of eye contact of humanoid Nao robot is similar to that of a human

    NARCIS (Netherlands)

    Cuijpers, R.H.; Pol, van der D.; Herrmann, G.; Pearson, M.J.; Lenz, A.; Bremner, P.; Spiers, A.; Leonards, U.

    2013-01-01

    Eye contact is an important social cue in human-human interaction, but it is unclear how easily it carries over to humanoid robots. In this study we investigated whether the tolerance of making eye contact is similar for the Nao robot as compared to human lookers. We measured the region of eye

  5. Influence of winter NAO pattern on variable renewable energies potential in Europe over the 20th century

    Science.gov (United States)

    François, Baptiste; Raynaud, Damien; Hingray, Benoit; Creutin, Jean-Dominique

    2017-04-01

    Integration of Variable Renewable Energy (VRE) sources in the electricity system is a challenge because of temporal and spatial fluctuations of their power generation resulting from their driving weather variables (i.e. solar radiation wind speed, precipitation, and temperature). Very few attention was paid to low frequency variability (i.e. from annual to decades) even though it may have significant impact on energy system and energy market Following the current increase in electricity supplied by VRE generation, one could ask the question about the risk of ending up in a situation in which the level of production of one or more VRE is exceptionally low or exceptionally high for a long period of time and/or over a large area. What would be the risk for an investor if the return on investment has been calculated on a high energy production period? What would be the cost in term of carbon emission whether the system manager needs to turn on coal power plant to satisfy the demand? Such dramatic events would definitely impact future stakeholder decision to invest in a particular energy source or another. Weather low frequency variability is mainly governed by large-scale teleconnection patterns impacting the climate at global scale such as El Niño - Southern Oscillation (ENSO) in the tropics and in North America or the North Atlantic Oscillation (hereafter, NAO) in North America and Europe. Teleconnection pattern's influence on weather variability cascades to VRE variability and ends up by impacting electricity system. The aim of this study is to analysis the impact of the NAO on VRE generation in Europe during the winter season. The analysis is carried out over the twentieth century (i.e. from 1900 to 2010), in order to take into account climate low frequency variability, and for a set of 12 regions covering a large range of climates in Europe. Weather variable time series are obtained by using the ERA20C reanalysis and the SCAMP model (Sequential Constructive

  6. Revisiting Caveiro Lake sediment record: the Holocene NAO and AMO impact on Pico Island (Azores archipelago)

    Science.gov (United States)

    Hernandez, A.; Giralt, S.; Raposeiro, P. M.; Gonçalves, V. M.; Pueyo, J. J.; Trigo, R. M.; Bao, R.; Sáez, A.

    2017-12-01

    Northern Hemisphere climate is partly conditioned by a number of atmospheric and oceanic patterns which occur in the North Atlantic sector. The favourable location of the Azores Archipelago (37°-40° N, 25°-31° W) results in a privileged place to generate high-resolution Holocene climatic proxy data that can contribute to deep our understanding on the evolution of these atmospheric and oceanic patterns. In the frame of three research projects, namely PALEONAO (CGL2010-15767), RAPIDNAO (CGL2013-40608-R) and PALEOMODES (CGL2016-75281-C2), high-resolution proxy-based reconstructions from Azores Archipelago have recently shown a combined impact of atmospheric and oceanic patterns at multiannual and decadal time-scales (Rubio-Inglés et al. 2016; Hernández et al. 2017). However, the long-term evolution coupling/uncoupling of these patterns is not well-determined yet. Here, we present a new high-resolution climate reconstruction based on the Caveiro Lake sedimentary sequence in order to fill this gap. Previously, Björck et al. (2006) studied a section of this sequence (the uppermost 4.6 m covering last 6 Ka cal BP) concluding that changes in the thermohaline circulation and the SST were the main drivers in the long-term precipitation variability, whereas the NAO impact was the main atmospheric driver of short-term precipitation changes. However, they only distinguished the NAO impact for the last 600 years owing to the low resolution of the study for the lower portion of the core. The new studied sequence (8.40 m long, 8.2 Ka cal BP) has been analysed at decadal-to centennial time-scale resolution for X-ray diffraction (XRD), X-ray fluorescence (XRF) core scanning and elemental and isotope geochemistry on bulk organic matter. The statistical multivariate analysis of the data highlights the main drivers triggering the sedimentary infill of the lake would be the NAO and AMO by controlling the lacustrine productivity via nutrients input. This new high

  7. A politica nuclear da Argentina e do Brasil : Desenvolvimento, nao-proliferacao e democratizacao

    OpenAIRE

    澤田, 眞治

    1994-01-01

    Este artigo e uma tentativa de analisar o desenvolvimento da politica da energia nuclear da Argentina e do Brasil, com relacao ao regime internacional de naoproliferacao das armas nucleares. Dado o fato de que ambos os paises da America do Sul recusaram a assinatura do TNP(Tratad0 sobre Nao-Proliferacao das Armas Nucleares), em razao do carater discriminatorio de inspecao, a Argentina e o Brasil estavam sendo considerado os estados duvidossos que potencialmente teriam a bomba atomica. A despe...

  8. In Situ Imaging the Oxygen Reduction Reactions of Solid State Na-O2 Batteries with CuO Nanowires as the Air Cathode.

    Science.gov (United States)

    Liu, Qiunan; Yang, Tingting; Du, Congcong; Tang, Yongfu; Sun, Yong; Jia, Peng; Chen, Jingzhao; Ye, Hongjun; Shen, Tongde; Peng, Qiuming; Zhang, Liqiang; Huang, Jianyu

    2018-05-14

    We report real time imaging of the oxygen reduction reactions (ORRs) in all solid state sodium oxygen batteries (SOBs) with CuO nanowires (NWs) as the air cathode in an aberration-corrected environmental transmission electron microscope under an oxygen environment. The ORR occurred in a distinct two-step reaction, namely, a first conversion reaction followed by a second multiple ORR. In the former, CuO was first converted to Cu 2 O and then to Cu; in the latter, NaO 2 formed first, followed by its disproportionation to Na 2 O 2 and O 2 . Concurrent with the two distinct electrochemical reactions, the CuO NWs experienced multiple consecutive large volume expansions. It is evident that the freshly formed ultrafine-grained Cu in the conversion reaction catalyzed the latter one-electron-transfer ORR, leading to the formation of NaO 2 . Remarkably, no carbonate formation was detected in the oxygen cathode after cycling due to the absence of carbon source in the whole battery setup. These results provide fundamental understanding into the oxygen chemistry in the carbonless air cathode in all solid state Na-O 2 batteries.

  9. Risk ranking of pathogens in ready-to-eat unprocessed foods of non-animal origin (FoNAO) in the EU: Initial evaluation using outbreak data (2007-2011)

    DEFF Research Database (Denmark)

    Da Silva Felício, M. T.; Hald, Tine; Liebana, E.

    2015-01-01

    Foods of non-animal origin (FoNAO) are consumed in a variety of forms, being a major component of almost all meals. These food types have the potential to be associated with large outbreaks as seen in 2011 associated with VTEC O104. In order to identify and rank specific food/pathogen combination...... processed, stored and prepared as part of the above data collection exercises....... most often linked to human cases originating from FoNAO in the EU, a semi-quantitative model was developed using seven criteria: strength of associations between food and pathogen based on the foodborne outbreak data from EU Zoonoses Monitoring (2007-2011), incidence of illness, burden of disease, dose......NAO in the EU. Efforts to collect additional data even in the absence of reported outbreaks as well as to enhance the quality of the EU-specific data, which was used as input for all the model criteria, will allow the improvement of the model outputs. Furthermore, it is recommended that harmonised terminology...

  10. How Does Mediterranean Basin's Atmosphere Become Weak Moisture Source During Negative Phase of NAO: Use of AIRS, AMSR, TOVS, & TRMM Satellite Datasets Over Last Two NAO Cycles to Examine Governing Controls on E-P

    Science.gov (United States)

    Smith, Eric A.; Mehta, Amita V.

    2008-01-01

    The Mediterranean Sea is a noted 'concentration" basin in that it almost continuously exhibits positive evaporation minus precipitation (E - P ) properties -- throughout the four seasons and from one year to the next. Nonetheless, according to the ECMWF Era-40 48-year (1958-2005) climate reanalysis dataset, for various phases of the North Atlantic Oscillation (NAO) when the pressure gradient between Portugal and Iceland becomes either very relaxed (large negative NAO-Index) or in transition (small positive or negative NAO-Index), the atmospheric moisture source properties of the basin become weak, at times even reversed for several months (i.e., negative E - P). This behavior poses numerous questions concerning how and why these events occur. Moreover, it begs the question of what it would take for the basin to reach its tipping point in which P would exceed E throughout the rainy season (some six months) on an annually persistent basis -- and the sea would possibly transform to a recurring "dilution" basin. This talk investigates these questions by: (1) establishing over a period from 1979 to present, based on detailed analyses of satellite retrieval products from a combination of NASA-AQUA, NOAA-LEO, NASA/JAXA Scatterometer, and NASA-TRMM platforms, plus additional specialized satellite data products and ancillary meteorological datasets, the actual observation-based behavior of E - P, (2) diagnosing the salient physical and meteorological mechanisms that lead to the weaker E - P events during the analysis period, partly based on analyzing surface and upper air data at discrete stations in the western and eastern Mediterranean -- while at the same time evaluating the quality of the ERA-40 data over this same time period, (3) conducting GCM and high-resolution regional modeling experiments to determine if perturbed but realistic meteorological background conditions could maintain Mediterranean as a "dilution" basin through the October to March rainy season on

  11. Eliminating drift of the head gesture reference to enhance Google Glass-based control of an NAO humanoid robot

    Directory of Open Access Journals (Sweden)

    Xiaoqian Mao

    2017-03-01

    Full Text Available This article presents a strategy for hand-free control of an NAO humanoid robot via head gesture detected by Google Glass-based multi-sensor fusion. First, we introduce a Google Glass-based robot system by integrating the Google Glass and the NAO humanoid robot, which is able to send robot commands through Wi-Fi communications between the Google Glass and the robot. Second, we detect the operator’s head gestures by processing data from multiple sensors including accelerometers, geomagnetic sensors and gyroscopes. Next, we use a complementary filter to eliminate drift of the head gesture reference, which greatly improves the control performance. This is accomplished by the high-pass filter component on the control signal. Finally, we conduct obstacle avoidance experiments while navigating the robot to validate the effectiveness and reliability of this system. The experimental results show that the robot is smoothly navigated from its initial position to its destination with obstacle avoidance via the Google Glass. This hands-free control system can benefit those with paralysed limbs.

  12. Variability modes of precipitation along a Central Mediterranean area and their relations with ENSO, NAO, and other climatic patterns

    Science.gov (United States)

    Kalimeris, Anastasios; Ranieri, Ezio; Founda, Dimitra; Norrant, Caroline

    2017-12-01

    This study analyses a century-long set of precipitation time series in the Central Mediterranean (encompassing the Greek Ionian and the Italian Puglia regions) and investigates the statistically significant modes of the interannual precipitation variability using efficient methods of spectral decomposition. The statistical relations and the possible physical couplings between the detected modes and the global or hemispheric patterns of climatic variability (the El Niño Southern Oscillation or ENSO, the North Atlantic Oscillation or NAO, the East Atlantic or EA, the Scandinavian or SCAND, and others) were examined in the time-frequency domain and low-order synchronization events were sought. Significant modes of precipitation variability were detected in the Taranto Gulf and the southern part of the Greek Ionian region at the sub-decadal scales (mostly driven by the SCAND pattern) and particularly at the decadal and quasi-decadal scales, where strong relations found with the ENSO activity (under complex implications of EA and NAO) prior to the 1930s or after the early-1970s. The precipitation variations in the Adriatic stations of Puglia are dominated by significant bi-decadal modes which found to be coherent with the ENSO activity and also weakly related with the Atlantic Ocean sea surface temperature intrinsic variability. Additionally, important discontinuities characterize the evolution of precipitation in certain stations of the Taranto Gulf and the Greek Ionian region during the early-1960s and particularly during the early-1970s, followed by significant reductions in the mean annual precipitation. These discontinuities seem to be associated with regional effects of NAO and SCAND, probably combined with the impact of the 1970s climatic shift in the Pacific and the ENSO variability.

  13. The near-term prediction of drought and flooding conditions in the northeastern United States based on extreme phases of AMO and NAO

    Science.gov (United States)

    Berton, Rouzbeh; Driscoll, Charles T.; Adamowski, Jan F.

    2017-10-01

    A series of hydroclimatic teleconnection patterns were identified between variations in either Atlantic or Pacific oceanic indices with precipitation and discharge anomalies in the northeastern United States. We hypothesized that temporal annual or seasonal changes in discharge could be explained by variations in extreme phases of the Atlantic Multi-decadal Oscillation (AMO index, SST: Sea Surface Temperature anomalies) and the North Atlantic Oscillation (NAO index, SLP: Sea-Level Pressure anomalies) up to three seasons in advance. The Merrimack River watershed, the fourth largest basin in New England, with a drainage area of 13,000 km2, is a compelling study site because it not only provides an opportunity to investigate the teleconnection between hydrologic variables and large-scale climate circulation patterns, but also how those patterns may become obscured by anthropogenic disturbances such as river regulation or urban development. We considered precipitation and discharge data of 21 gauging stations within the Merrimack River watershed, including the Hubbard Brook Experimental Forest (HBEF), NH, with a median record length of 55 years beginning as early as 1904. The discharge anomalies were statistically significant (p-value ≤ 0.2) between extreme positive and negative phases of AMO (1857-2011) and NAO (1900-2011) and revealed the potential teleconnectivity of climate circulation patterns with discharge. Annual and seasonal correlations of discharge were examined with the extreme phases of AMO and NAO at zero-, one-, or two- year/season lags (total of 30 scenarios). When AMO was greater than 0.2, the strongest correlations of AMO and NAO with discharge were observed at headwater catchments. This correlation weakened downstream towards larger regulated and/or developed sub-basins. We introduced a simple approach for near-term prediction of drought and flooding events. An exponential decay function was regressed through the historic occurrence of the relative

  14. The NAO Influence on the Early to Mid-Holocene North Atlantic Coastal Upwelling

    Science.gov (United States)

    Hernandez, A.; Cachão, M.; Sousa, P.; Trigo, R. M.; Freitas, M. C.

    2017-12-01

    Coastal upwelling regions yield some of the oceanic most productive ecosystems, being crucial for the worldwide social and economic development. Most upwelling systems, emerging cold nutrient-rich deep waters, are located in the eastern boundaries of the Atlantic and Pacific basins, and are driven by meridional wind fields parallel to the coastal shore. These winds are associated with the subsiding branch of the large-scale Anticyclonic high pressure systems that dominate the subtropical ocean basins, and therefore can be displaced or intensified within the context of past and future climate changes. However, the role of the current global warming influencing the coastal upwelling is, as yet, unclear. Therefore it is essential to derive a long-term perspective, beyond the era of instrumental measurements, to detect similar warm periods in the past that have triggered changes in the upwelling patterns. In this work, the upwelling dynamics in the Iberian North Atlantic margin during the early and mid-Holocene is reconstructed, using calcareous nannofossils from a decadally resolved estuarine sediment core located in southwestern Portugal. Results suggest that the coastal dynamics reflects changes in winds direction likely related to shifts in the NAO-like conditions. Furthermore, the reconstructed centennial-scale variations in the upwelling are synchronous with changes in solar irradiance, a major external forcing factor of the climate system that is known to exert influence in atmospheric circulation patterns. In addition, these proxy-based data interpretations are in agreement with wind field and solar irradiance simulation modelling for the mid-Holocene. Therefore, the conclusion that the solar activity via the NAO modulation controlled the North Atlantic upwelling of western Iberia during the early and mid-Holocene at decadal to centennial timescales can be derived. The financial support for attending this meeting was possible through FCT project UID/GEO/50019

  15. Localización probabilística del humanoide Nao en el campo de la RoboCup

    OpenAIRE

    García Sierra, Juan Felipe; Fernández Llamas, Camino; Matellán Olivera, Vicente; Rodríguez Lera, Francisco Javier

    2010-01-01

    Una de las habilidades fundamentales que debe poseer un robot para definirse como autónomo es la de autolocalizarse en un entorno dado. En este artículo abordaremos el problema de la localización aplicando técnicas probabilísticas combinando representaciones topológicas y métricas sobre un terreno acotado como es el campo de fútbol de la RoboCup. El artículo presenta también el funcionamiento y resultados obtenidos sobre un conjunto de pruebas simuladas y reales utilizando el humanoide Nao...

  16. Teleconnections in Groundwater of U.S. Principal Aquifers to the Non-Stationarity of ENSO, NAO, PDO, and AMO

    Science.gov (United States)

    Gurdak, J. J.; Kuss, A. M.

    2012-12-01

    Groundwater will play an important role in society's adaptation to climate variability and change. Therefore, it is particularly important to detect and quantify teleconnections in groundwater with non-stationarity in climate variability on interannual to multidecadal timescales because of the tangible and near-term implications for water-resource management. Interannual to multidecadal climate variability partially controls precipitation distribution in space and time, drought frequency and severity, snowmelt runoff, streamflow, and other hydrologic processes that profoundly affects surface-water resources. However, the effects of interannual to multidecadal climate variability on recharge rates and mechanisms and other subsurface hydrologic processes that affect groundwater quantity and quality are largely unknown in most aquifers of the United States (U.S.) and other regions of the world. Here we use singular spectrum analysis (SSA), wavelet coherence analysis, and lag correlation to quantify the effects of the El Niño Southern Oscillation (ENSO) (2-7 year cycle), North Atlantic Oscillation (NAO) (3-6 year cycle), Pacific Decadal Oscillation (PDO) (10-25 year cycle), and Atlantic Multidecadal Oscillation (AMO) (50-70 year cycle) on precipitation, groundwater levels, simulated groundwater pumping, and climate varying recharge rates across the regionally extensive Central Valley (52,000 km2), Basin and Range (700,000 km2), High Plains (450,000 km2), and North Atlantic Coastal Plain (130,000 km2) Principal Aquifers (PAs) of the U.S. The results indicate that precipitation, recharge, and groundwater levels are partially affected by interannual to multidecadal climate variability and groundwater-level fluctuations are not solely a function of temporal patterns in pumping. ENSO and PDO have a greater control than NAO and AMO on variability in precipitation and groundwater levels across the U.S., particularly in the western and central PAs. At many locations, recharge

  17. Progress in Suppressing Scattered Light into the Optical Beam Path of the NAO Rozhen 2m Telescope

    Science.gov (United States)

    Ovcharov, E. P.; Petrov, N.; Markov, H.; Bonev, T.; Donchev, Z.

    2010-09-01

    In this poster paper we present a summary of the published analysis of the spatial dependence of the magnitudes derived from images obtained in the RC focal plane of the 2m RCC NAO Rozhen telescope. An alert for the possible reason was the unusually curved flat-field images taken as a part of the standard CCD calibration procedure. The reasons for the problem are described and a solution is presented, which consists modification of the mirror baffles and mounting of special diaphragm at the entrance of the filter wheel.

  18. The influences of the AMO and NAO on the sedimentary infill in an Azores Archipelago lake since ca. 1350 CE

    Science.gov (United States)

    Hernández, Armand; Sáez, Alberto; Bao, Roberto; Raposeiro, Pedro M.; Trigo, Ricardo M.; Doolittle, Sara; Masqué, Pere; Rull, Valentí; Gonçalves, Vítor; Vázquez-Loureiro, David; Rubio-Inglés, María J.; Sánchez-López, Guiomar; Giralt, Santiago

    2017-07-01

    The location of the Azores Archipelago in the North Atlantic makes this group of islands an excellent setting to study the long-term behavior of large oceanic and atmospheric climate dynamic patterns, such as the Atlantic Multidecadal Oscillation (AMO) and the North Atlantic Oscillation (NAO). Here, we present the impacts of these patterns on Lake Empadadas (Azores Archipelago) from the Medieval Climate Anomaly (MCA) - Little Ice Age (LIA) transition to the present based on sedimentological, geochemical and biological characterizations of the sedimentary record. Multivariate analyses of a number of proxies including X-ray fluorescence (XRF), X-ray diffraction (XRD), total organic and inorganic carbon (TOC and TIC) and diatom life forms abundance reveal that the sedimentary infill evolution has been controlled by (i) fluctuations in the lake level and (ii) variations in organic matter accumulation. Both processes are governed by climate variability and modulated by anthropogenic activities associated with changes on the lake catchment. Changes in these two sedimentary processes have been used to infer five stages: (i) the MCA-LIA transition (ca. 1350-1450 CE) was characterized by a predominantly positive AMO phase, which led to intermediate lake levels and high organic matter concentration; (ii) the first half of the LIA (ca. 1450-1600 CE) was characterized by predominant lowstand conditions and intermediate organic matter deposition mainly related to negative AMO phases; (iii) the second half of the LIA (ca. 1600-1850 CE) was characterized by negative AMO and NAO phases, implying intermediate lake levels and high organic matter deposition; (iv) the Industrial era (ca. 1850-1980 CE) was characterized by the lowest lake level and organic matter accumulation associated with negative AMO phases; and (v) the period spanning between 1980 CE and the present reveals the highest lake levels and low organic matter deposition, being associated with very positive AMO

  19. Diversity and uses of Zingiberaceae in Nam Nao National Park, Chaiyaphum and Phetchabun provinces, Thailand, with a new record for Thailand

    Directory of Open Access Journals (Sweden)

    Surapon Saensouk

    2016-11-01

    Full Text Available Three tribes, 12 genera and 38 species of the ginger family (Zingiberaceae along five routes in Nam Nao National Park were surveyed between January 2012 and December 2013 to determine their diversity, ecological data, phenology, uses and conservation status. The highest diversity was found in the tribe Zingibereae (6 genera and 21 species, of which the genera Curcuma and Zingiber comprised the highest number species (eight species each. A species key was constructed based on morphology. The ginger family was found in four forest-types—deciduous dipterocarp forest, mixed deciduous forest, dry evergreen forest and pine forest. The most flowering bloom of the ginger family in Nam Nao National Park was during March to August and the most fruiting bloom was during June to September. The popular uses of Zingiberaceae were as a food, spice, in medicine, as ornamentation and in rituals. Eight species have been evaluated as of least concern and are presented in the IUCN Red List, while two rare species were reported in Thailand Red Data: Plants, while six rare Zingiberaceae species were identified based on the evaluation criteria of Saensouk (2011. Four species were endemic to Thailand. Moreover, Etlingera yunnanensis (T. L. Wu & S. J. Chen R. M. Smith was a new record for Thailand.

  20. Detecting the Benefits of Shade Management in the Thermal Regime of an Upland River Under Positive and Negative Phases of the NAO

    Science.gov (United States)

    Wilby, R.; Johnson, M. F.

    2017-12-01

    Water temperature is an important determinant of river ecosystem function and health. Hence, there is growing concern about rising surface water temperatures as a consequence of global warming and human modifications to river regimes. Some agencies are advocating riparian shade management as a means of `keeping rivers cool'. As appealing as this policy might seem, there are a host of practical considerations such as which species to plant, where to plant, and how much to plant? Moreover, there can be unintended consequences for groundwater recharge, flood risk and nutrient fluxes through the buffer zone. The thermal benefits of tree-planting may also be hard to detect amidst the integrated, downstream effects of landscape shade and flows from springs. Yet, to truly evaluate shade management as an adaptation to climate change, clear evidence is needed of the costs and benefits of this local intervention. What has this got to do with natural modes of climate variability? Continental scale, hydrological impacts of ENSO, the PDO and NAO have been widely reported - these periodic variations in ocean-atmosphere circulations are often blamed for floods, droughts, wildfire, crop failures, and the like. But there is emerging evidence that such phenomena also drive inter-annual variations in the heat flux of rivers. This matters because the underlying signal can confound field and model experiments intended to test adaptation options. Here, we present evidence of NAO signatures in the water temperature regime of the River Dove, UK. We compare the amplitude of these thermal variations with the expected benefit of tree planting. We demonstrate that the difference in maximum summer water temperature between strongly positive and strongly negative NAO phases can be about 2.5°C. This is equivalent to the thermal benefit of more than 2 km of riparian shade for the river studied. So, whilst modes of climate variability undoubtedly have a global footprint, let us not forget that

  1. Catalytic Activity and Nuclear Radiation; L'activite catalytique et les rayonnements nucleaires; Kataliticheskaya aktivnost' i yadernoe izluchenie; La actividad catalitica y las radiaciones nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Turkevich, J.; Ikawa, T.; Nozaki, F.; Stamires, D. [Princeton University, N.J (United States)

    1963-11-15

    remplacant en partie l e sodium d'un tamis moleculaire du type Linde Y (Na{sub 56}(AlO{sub 2}){sub 56}(SiO{sub 2}){sub 126}) par l'ion ammonium pour l e decomposer ensuite de maniere a retirer a la fois l'ammoniaque et l'eau, ce qui cree des sites depourvus d e cations dans le tamis. Ils ont prepare une serie de ces catalyseurs possedant des nombres regulierement croissants de sites decationises (de 0 a 100%par rapport a la teneur primitive en sodium). Ils ont etudie l'activite catalytique de ces deux series de catalyseurs avant et apres exposition aux rayons gamma, en observant ia cinetique de la decomposition du cumene en benzene et propylene, l'isomerisation du butene - 1 en butene-2 par deplacement de la double liaison et la reaction d'echange hydrogene-deuteriu'm. Le nombre des sites actifs a ete determine par empoisonnement progressif a la quinoleine; on a donc pu chiffrer l'activite par site. Les auteurs ont aussi etudie ces substances en mesurant la resonance de spin des electrons pour des agents de transfert des electrons adsorbes, notamment la triphenylamine, le perylene et le diphenylethylene symetrique. Ils ont constate que la capacite de transfert des electrons est parallele a l'activite catalytique. lis ont pris la resonance protonique de l'eau absorbee pour caracteriser la nature du site catalytique. (author) [Spanish] Los autores exponen los resultados de nuevos trabajos acerca de los efectos de los rayos gamma sobre la actividad catalitica de un gel de silice y alumina y sobre tamices moleculares descationizados del tipo Linde Y. A tal efecto, prepararon una serie graduada de catalizadores de gel de silice y alumina coprecipitados, con diez distintos valores equidistantes para la razon atomica alumina/silice. Otra serie de catalizadores se obtuvo sustituyendo parcialmente el sodio de un tamiz molecular Linde Y, Na{sup 56}(AlO{sub 2}){sub 56}(SiO{sub 2}){sub 126}, por el ion amonio y descomponiendolo despues para expulsar tanto el amonio como el agua, con lo

  2. Determination of the absolute second-order rate constant for the reaction Na + O3 → NaO + O2

    International Nuclear Information System (INIS)

    Husain, David; Marshall, Paul; Plane, J.M.C.

    1985-01-01

    The absolute second-order rate constant for the reaction Na + O 3 -> NaO + O 2 (k 1 ) has been determined by time-resolved atomic resonance absorption spectroscopy at lambda = 589 nm [Na(3 2 Psub(j)) 2 Ssub(1/2))] following pulsed irradiation, coupled with monitoring of O 3 by light absorption in the ultra-violet; this yields k 1 (500 K) = 4(+4,-2) x 10 -10 cm 3 molecule -1 s -1 , resolving large differences for various estimates of this important quantity used in modelling the sodium layer in the mesosphere. (author)

  3. Type II Cepheids: evidence for Na-O anticorrelation for BL Her type stars?

    Science.gov (United States)

    Kovtyukh, V.; Yegorova, I.; Andrievsky, S.; Korotin, S.; Saviane, I.; Lemasle, B.; Chekhonadskikh, F.; Belik, S.

    2018-06-01

    The chemical composition of 28 Population II Cepheids and one RR Lyrae variable has been studied using high-resolution spectra. The chemical composition of W Vir variable stars (with periods longer than 8 d) is typical for the halo and thick disc stars. However, the chemical composition of BL Her variables (with periods of 0.8-4 d) is drastically different, although it does not differ essentially from that of the stars belonging to globular clusters. In particular, the sodium overabundance ([Na/Fe] ≈ 0.4) is reported for most of these stars, and the Na-O anticorrelation is also possible. The evolutionary tracks for BL Her variables (with a progenitor mass value of 0.8 solar masses) indicate that mostly helium-overabundant stars (Y = 0.30-0.35) can fall into the instability strip region. We suppose that it is the helium overabundance that accounts not only for the existence of BL Her variable stars but also for the observed abnormalities in the chemical composition of this small group of pulsating variables.

  4. The Little Ice Age was 1.0-1.5 °C cooler than current warm period according to LOD and NAO

    Science.gov (United States)

    Mazzarella, Adriano; Scafetta, Nicola

    2018-02-01

    We study the yearly values of the length of day (LOD, 1623-2016) and its link to the zonal index (ZI, 1873-2003), the Northern Atlantic oscillation index (NAO, 1659-2000) and the global sea surface temperature (SST, 1850-2016). LOD is herein assumed to be mostly the result of the overall circulations occurring within the ocean-atmospheric system. We find that LOD is negatively correlated with the global SST and with both the integral function of ZI and NAO, which are labeled as IZI and INAO. A first result is that LOD must be driven by a climatic change induced by an external (e.g. solar/astronomical) forcing since internal variability alone would have likely induced a positive correlation among the same variables because of the conservation of the Earth's angular momentum. A second result is that the high correlation among the variables implies that the LOD and INAO records can be adopted as global proxies to reconstruct past climate change. Tentative global SST reconstructions since the seventeenth century suggest that around 1700, that is during the coolest period of the Little Ice Age (LIA), SST could have been about 1.0-1.5 °C cooler than the 1950-1980 period. This estimated LIA cooling is greater than what some multiproxy global climate reconstructions suggested, but it is in good agreement with other more recent climate reconstructions including those based on borehole temperature data.

  5. Jian Nao Ning for Treatment of Memory Impairment in Patients with Mild or Moderate Multi-infarct Dementia

    Institute of Scientific and Technical Information of China (English)

    田金洲; 尹军祥; 刘峘; 杨承芝; 王永炎

    2002-01-01

    Forty patients with multi-infarct dementia (MID) were randomly assigned to the treatment group (25 cases) treated with Jian Nao Ning (健脑宁JNN) and the duxil control group (15 cases). Memory function were assessed at baseline and endpoint using memory subscales of a battery of New Psychometric Tests (Chinese version) including mini-mental state examination (MMSE), verbal memory, and non-verbal memory, etc. After treatment, the mean scores of verbal memory in the Hopkins Verbal Learning Test (P<0.05) and total memory scores of memory items (P<0.001) in JNN group increased significantly; and improvement in episodic memory function including story recall (immediate and delayed), delayed word recall, verbal learning and verbal recognition and visual recognition in the JNN group was better than that in the duxil control group, suggesting that JNN can obviously improve memory function for the patients with mild or moderate multi-infarct dementia.

  6. Na-O abundances in M53: A Mostly First Generation Globular Cluster

    Science.gov (United States)

    Boberg, Owen M.; Friel, Eileen D.; Vesperini, Enrico

    2016-01-01

    We present the Fe, Ca, Ti, Ni, Ba, Na, and O abundances for a sample of 53 red giant branch (RGB) stars in the globular cluster (GC) NGC 5024 (M53). The abundances were measured from high signal-to-noise medium resolution spectra collected with the Hydra multi-object spectrograph on the WIYN 3.5- meter telescope. M53 is of interest because previous studies based on the morphology of the cluster's horizontal branch suggested that it might be composed primarily of first generation (FG) stars and differ from the majority of other GCs withmultiple populations, which have been found to be dominated by second generation (SG) stars. Our sample has an average [Fe/H] = -2.07 with a standard deviation of 0.07 dex. This value is consistent with previouslypublished results. The alpha-element abundances in our sample are also consistent with the trends seen in Milky Way halo stars at similar metallicities, with enhanced [Ca/Fe] and [Ti/Fe] relative to solar. We find thatthe Na-O anti-correlation is not as extended as other GCs with similarly high masses. The fraction of SG to FG stars in our sample is approximately 1:3 and the SG is more centrally concentrated. These findings further support that M53 might be a mostly FG cluster and could give further insight into how GCs formed the light element abundance patterns we observe in them today.

  7. Fabiola Gianotti "O universo que vemos, estrelas, planetas e galaxias, é apenas 5% do que là està. Nao hà instrumentos que nos permitam observar o restantes 95%, que sao o que chamamos matéria escura e energia"

    CERN Document Server

    Caetano, Emilia

    2017-01-01

    Fabiola Gianotti "O universo que vemos, estrelas, planetas e galaxias, é apenas 5% do que là està. Nao hà instrumentos que nos permitam observar o restantes 95%, que sao o que chamamos matéria escura e energia"

  8. Electrodeposition of Ni-Mo nanoparticles for the electrocatalytic hydrogen evolution reaction; Electrodepositacion de nanoparticulas de Ni-Mo para la electrocatalisis de la reaccion de evolucion de hidrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Videa, M.; Crespo, D.; Casillas, G.; Zavala, G. [Tecnologico de Monterrey Campus Monterrey, Monterrey, Nuevo Leon (Mexico)]. E-mail: mvidea@eitesm.mx

    2009-09-15

    This work reports on the generation of nickel- molybdenum deposits from the application of direct current in an electrolytic bath composed of a basic solution of NiSO{sub 4}, Na{sub 2}MoO{sub 4} and Na{sub 3}C{sub 6}H5O7. The working electrodes used were 1mm diameter vitreous carbon discs and carbon felt. The catalytic activity of the deposits was evaluated with cyclic voltamperometry in a 0.72M solution of H{sub 2}SO{sub 4}. Deposits were generated on the vitreous carbon discs, which showed catalytic activity for the HER. Deposits were obtained with better properties, showing a pulse of 200 mA/cm{sup 2}. The 42 mA/cm{sup 2} pulse experiments with varying durations showed that their catalytic capacities are better than expected, in spite of the use of small quantities of charge obtained with 90 ms and 300s. Low activity was observed in the absence of MoO{sub 4}{sup 2-} in the electrolytic bath during the electrodeposition process, indicating the importance of the presence of Mo to the catalytic activity. The deposits were inspected using atomic force microscopy (AFM). Though the electrodeposition on carbon felt is possible, the experiments were not reproducible because control over the active area of the electrode is difficult to achieve. NiMo nanoparticles on carbon filter fibers can be obtained using pulses with sufficient intensity and duration. [Spanish] En este trabajo se reporta la generacion de depositos de niquel-molibdeno mediante la aplicacion de corriente directa en un bano electrolitico compuesto por una solucion basica de NiSO{sub 4}, Na{sub 2}MoO{sub 4} y Na{sub 3}C{sub 6}H5O7. Se utilizaron como electrodos de trabajo discos de carbon vitreo de 1mm de diametro y fieltro de carbono. La actividad catalitica de los depositos fue evaluada mediante voltamperometria ciclica en una solucion 0.72M de H{sub 2}SO{sub 4}. Sobre los electrodos de carbon vitreo se generaron depositos que mostraron actividad catalitica para la REH. Depositos con mejores propiedades

  9. Influence of the North Atlantic Oscillation on European tropospheric composition: an observational and modelling study

    Science.gov (United States)

    Pope, R.; Chipperfield, M.

    2017-12-01

    The North Atlantic Oscillation (NAO) has a strong influence on winter-time North Atlantic and European circulation patterns. Under the positive phase of the NAO (NAO+), intensification of the climatological Icelandic low and Azores high pressure systems results in strong westerly flow across the Atlantic into Europe. Under the NAO negative phase (NAO-), there is a weakening of this meridional pressure gradient resulting in a southerly shift in the westerlies flow towards the sub-tropical Atlantic. Therefore, NAO+ and NAO- introduce unstable stormy and drier stable conditions into Europe, respectively. Under NAO+ conditions, the strong westerlies tend to enhance transport of European pollution (e.g. nitrogen oxides) away from anthropogenic source regions. While during NAO-, the more stable conditions lead to a build up of pollutants. However, secondary pollutants (i.e. tropospheric ozone) show the opposite signal where NAO+, while transporting primary pollutants away, introduces Atlantic ozone enriched air into Europe. Here ozone can form downwind of pollution from continental North America and be transported into Europe via the westerly flow. Under NAO-, this westerly ozone transport is reduced yielding lower European ozone concentrations also depleted further by ozone loss through the reaction with NOx, which has accumulated over the continent. Peroxyacetyl nitrate (PAN), observed in the upper troposphere - lower stratosphere (UTLS) by satellite, peaks over Iceland/Southern Greenland in NAO-, between 200-100 hPa, consistent with trapping by an anticyclone at this altitude. During NAO+, PAN is enhanced over the sub-tropical Atlantic and Arctic. Model simulations show that enhanced PAN over Iceland/Southern Greenland in NAO- is associated with vertical transport from the troposphere into the UTLS, while peak Arctic PAN in NAO+ is its accumulation given the strong northerly meridional transport in the UTLS. UTLS ozone spatial anomalies, relative to the winter

  10. Decreasing extracellular Na+ concentration triggers inositol polyphosphate production and Ca2+ mobilization

    International Nuclear Information System (INIS)

    Smith, J.B.; Dwyer, S.D.; Smith, L.

    1989-01-01

    Removing extracellular Na+ (Na+o) evoked a large increase in cytosolic free Ca2+ concentration ([Ca2+]i in human skin fibroblasts. Decreasing [Na+]o from 120 to 14 mM caused the half-maximal peak increase in [Ca2+]i. Removing Na+o strongly stimulated 45 Ca2+ efflux and decreased total cell Ca2+ by about 40%. Bradykinin caused changes in [Ca2+]i, total Ca2+, and 45 Ca2+ fluxes similar to those evoked by removing Na+o. Prior stimulation of the cells with bradykinin prevented Na+o removal from increasing [Ca2+]i and vice versa. Na+o removal rapidly increased [ 3 H]inositol polyphosphate production. Loading the cells with Na+ had no effect on the increase in 45 Ca2+ efflux produced by Na+o removal. Therefore, decreasing [Na+]o probably stimulates a receptor(s) which is sensitive to extracellular, not intracellular, Na+. Removing Na+o also mobilized intracellular Ca2+ in smooth muscle and endothelial cells cultured from human umbilical and dog coronary arteries, respectively

  11. On the dynamics of an extreme rainfall event in northern India in 2013

    Indian Academy of Sciences (India)

    39

    htm#nao). North-. 12 eastern Africa, Karakoram regions are also influenced by NAO; and rainfall occurs during the. 13 negative phase of NAO (McHugh et al., 2001; Archer et al., 2004). Many studies have also shown. 14 that NAO can influence ...

  12. The Energy Cascade Associated with the North Atlantic Oscillation

    Science.gov (United States)

    Castanheira, J. M.; Marques, C. A. F.

    2017-12-01

    The North Atlantic Oscillation or Arctic Oscillation (NAO/AO), in a more hemispheric expression, is the dominant mode of variability of the extratropical atmospheric circulation. In the literature which analyses the association of low frequency variability of the NAO/AO with other climate variables, it is very common to find the idea of circulation and climate impacts of the NAO/AO. It is usually suggested that the NAO influences the position of North Atlantic storm tracks and the related transport of heat and moisture. However, in spite of the long time since the NAO variability mode was uncovered (Walker and Bliss, 1932), its underlying dynamical mechanisms are not well understood yet. In fact, it is not yet consensual that the NAO influences the position of the storm tracks, being possible that the relationship is in the opposite way with the storm track activity influencing de NAO. In this communication we will present an analysis of anomalies of the energy cascade associated with the NAO. A detailed version of the Lorenz energy cycle, which decomposes the energy flows into baroclinic and barotropic terms and into zonal mean and eddy components, was applied to the 6-hourly ERA-I reanalysis for the period of 1979 to 2016. The obtained results show that the positive NAO phase is preceded by an significant increase of synoptic baroclinic eddy activity. The eddy available potential energy is converted into kinetic energy and transferred to barotropic synoptic eddies. Then, the kinetic energy is transferred upscale into the barotropic planetary waves, which reproduce the NAO pattern. Therefore, we conclude that the synoptic baroclinic eddy activity forces the NAO variability. No clear signal was found for a modulating role of the NAO in the baroclinic eddy activity.

  13. Unigene BLAST: CBRC-DRER-15-0112 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0112 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 7e-49 71% ...

  14. Unigene BLAST: CBRC-DRER-15-0109 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0109 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 4e-51 71% ...

  15. Unigene BLAST: CBRC-DRER-15-0107 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0107 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 3e-59 84% ...

  16. Unigene BLAST: CBRC-DRER-15-0115 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0115 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 1e-41 67% ...

  17. Unigene BLAST: CBRC-DRER-15-0111 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0111 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 4e-48 73% ...

  18. Unigene BLAST: CBRC-DRER-15-0105 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0105 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 9e-35 69% ...

  19. Unigene BLAST: CBRC-DRER-15-0102 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0102 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 7e-30 54% ...

  20. Unigene BLAST: CBRC-DRER-15-0103 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0103 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 6e-32 56% ...

  1. Unigene BLAST: CBRC-DRER-15-0101 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0101 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 3e-47 77% ...

  2. Unigene BLAST: CBRC-DRER-15-0113 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0113 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 2e-51 73% ...

  3. Unigene BLAST: CBRC-DRER-15-0114 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0114 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 1e-38 62% ...

  4. Unigene BLAST: CBRC-DRER-15-0108 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0108 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 7e-53 74% ...

  5. Unigene BLAST: CBRC-DRER-15-0100 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0100 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 3e-52 75% ...

  6. Unigene BLAST: CBRC-DRER-15-0106 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0106 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 2e-51 75% ...

  7. Unigene BLAST: CBRC-DRER-15-0110 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0110 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 2e-71 99% ...

  8. Unigene BLAST: CBRC-DRER-15-0104 [SEVENS

    Lifescience Database Archive (English)

    Full Text Available CBRC-DRER-15-0104 gnl|UG|Dr#S24600640 nao61h10.y1 Zebrafish Posterior segment. Unno...rmalized (nao) Danio rerio cDNA clone nao61h10 5', mRNA sequence /clone=nao61h10 /clone_end=5' /gb=DN895013 /gi=62879776 /ug=Dr.126440 /len=809 5e-58 79% ...

  9. Variations in suicide method and in suicide occurrence by season and day of the week in Russia and the Nenets Autonomous Okrug, Northwestern Russia: a retrospective population-based mortality study.

    Science.gov (United States)

    Sumarokov, Yury A; Brenn, Tormod; Kudryavtsev, Alexander V; Nilssen, Odd

    2015-09-23

    Suicide is an important world health issue, especially in territories inhabited by indigenous people. This investigated differences in suicide rates, suicide methods, and suicide occurrence by month and day of the week among the indigenous and non-indigenous populations of the Nenets Autonomous Okrug (NAO) and to compare the findings from the NAO with national Russian statistics. In this retrospective population-based mortality study we investigated all suicides that occurred in the NAO in 2002-2012 (N = 252). Suicide method and the month and day of the week suicide occurred was taken from autopsy reports and disaggregated by ethnic group (indigenous and non-indigenous) and sex. Data from the NAO were then compared with national data from the Russian Federal Statistics Service (Rosstat). Hanging was the most common suicide method in the NAO in both indigenous and non-indigenous populations. The proportion of suicides by hanging among males was lower in the NAO than in national data (69.3 vs 86.2 %), but the inverse was true for females (86.5 vs 74.9 %). Suicide by firearm and by cutting was significantly higher among the indigenous population in the NAO when compared with national data. Peaks in suicide occurrence were observed in May and September in the NAO, whereas national data showed only one peak in May. Suicide occurrence in the indigenous population of the NAO was highest in April, while the non-indigenous population showed peaks in May and September. Suicide occurrence in the NAO was highest on Fridays; in national data this occurrence was highest on Mondays. We showed different relative frequencies of suicide by hanging, cutting, and firearm, as well as different suicide occurrence by month and day of the week in the NAO compared with Russia as a whole. These results can be used to plan suicide prevention activities in the Russian Arctic.

  10. Development of the Wintertime Sr/Ca-SST Record from Red Sea Corals as a Proxy for the North Atlantic Oscillation

    Science.gov (United States)

    Bernstein, W. N.; Hughen, K. A.

    2009-12-01

    The North Atlantic Oscillation (NAO) is one of the most pronounced and influential patterns in winter atmospheric circulation variability. This meridional redistribution of atmospheric mass across the Atlantic Ocean produces large changes in the intensity, number and direction of storms generated within the basin, and the regional climate of surrounding continents. The NAO exerts a significant impact on society, through influences on agriculture, fisheries, water management, energy generation and coastal development. NAO effects on climate extend from eastern North America across Europe to the eastern Mediterranean and Middle East. Changes in NAO behavior during the late 20th century have been linked to global warming; yet despite its importance, the causes and long-term patterns of NAO variability in the past remain poorly understood. In order to better predict the influence of the NAO on climate in the future, it is critical to examine multi-century NAO variability. The Red Sea is an excellent location from which to generate long NAO records for two reasons. First, patterns of wintertime sea surface temperature (SST) and salinity (SSS) in the Red Sea are highly correlated with NAO variability (Visbeck et al. 2001; Hurrell et al. 2003). Second, the tropical/subtropical Red Sea region contains fast growing long-lived massive Porites spp. corals with annually banded skeletons. These corals are ideal for generating well-dated high-resolution paleoclimatic records that extend well beyond the instrumental period. Here we present a study of winter SST and NAO variability in the Red sea region based on coral Sr/Ca data. In 2008, we collected multiple drill cores ranging in length from 1 to 4.1 meters from Porites corals at six sites spanning a large SST gradient. Sr/Ca measurements from multiple corals will be regressed against 23 years of satellite SST data, expanding the SST range over which we calibrate. A sampling resolution of 0.5mm will yield greater than bi

  11. Use of Bacillus subtilis isolates from Tua-nao towards nutritional improvement of soya bean hull for monogastric feed application.

    Science.gov (United States)

    Wongputtisin, P; Khanongnuch, C; Kongbuntad, W; Niamsup, P; Lumyong, S; Sarkar, P K

    2014-09-01

    Soya bean hull (SBH) is a cheap and high-fibre content feed ingredient that obtained after soya bean oil extraction. Microbial fermentation was expected to improve SBH qualities before applying to animals, especially monogastric animals. Two bacterial strains, Bacillus subtilis MR10 and TK8 that were isolated from Tua-nao, a traditional fermented soya bean in northern Thailand, were used for fermented soya bean hull (FSBH) production. Both could easily grow at 37°C in SBH as the sole substrate. MR10 produced the highest β-mannanase activity (400 U g(-1) SBH) on day 2, while TK8 produced the highest cellulase activity (14·5 U g(-1) SBH) on day 3. After fermentation, the nutritional quality of SBH was obviously improved by an increase in soluble sugars, soluble proteins, crude protein and crude lipid, and a decrease in the content of raffinose family oligosaccharides. Scavenging activity (%) of SBH against ABTS radical cation was also increased from 14 to 27 and 20% by MR10 and TK8 fermentation, respectively. According to the GRAS property of these both strains and various improvements of nutritional values, the fermented SBH proved to be a potential feed ingredient, especially for the monogastric animals. Normally, soya bean hull has been recognized as only a worthless by-product from soya bean oil production process because of its low utilizable nutrients. Our study introduced an alternative way to utilize this worthless residue using biotechnological knowledge. The nutritional quality of soya bean hull was improved by microbial fermentation. Fermented soya bean hull can be used as a cheap, safe and high-nutrient feed ingredient for livestock production, especially monogastric animals, to promote their growth performances, instead of using antibiotics in some regions of the world. © 2014 The Society for Applied Microbiology.

  12. Spatial patterns of North Atlantic Oscillation influence on mass balance variability of European glaciers

    Directory of Open Access Journals (Sweden)

    B. Marzeion

    2012-06-01

    Full Text Available We present and validate a set of minimal models of glacier mass balance variability. The most skillful model is then applied to reconstruct 7735 individual time series of mass balance variability for all glaciers in the European Alps and Scandinavia. Subsequently, we investigate the influence of atmospheric variability associated with the North Atlantic Oscillation (NAO on the glaciers' mass balances.

    We find a spatial coherence in the glaciers' sensitivity to NAO forcing which is caused by regionally similar mechanisms relating the NAO forcing to the mass balance: in southwestern Scandinavia, winter precipitation causes a correlation of mass balances with the NAO. In northern Scandinavia, temperature anomalies outside the core winter season cause an anti-correlation between NAO and mass balances. In the western Alps, both temperature and winter precipitation anomalies lead to a weak anti-correlation of mass balances with the NAO, while in the eastern Alps, the influences of winter precipitation and temperature anomalies tend to cancel each other, and only on the southern side a slight anti-correlation of mass balances with the NAO prevails.

  13. Winter North Atlantic Oscillation impact on European precipitation and drought under climate change

    Science.gov (United States)

    Tsanis, I.; Tapoglou, E.

    2018-01-01

    The North Atlantic Oscillation (NAO) is responsible for the climatic variability in the Northern Hemisphere, in particular, in Europe and is related to extreme events, such as droughts. The purpose of this paper is to study the correlation between precipitation and winter (December-January-February-March (DJFM)) NAO both for the historical period (1951-2000) and two future periods (2001-2050 and 2051-2100). NAO is calculated for these three periods by using sea level pressure, while precipitation data from seven climate models following the representative concentration pathway (RCP) 8.5 are also used in this study. An increasing trend in years with positive DJFM NAO values in the future is defined by this data, along with higher average DJFM NAO values. The correlation between precipitation and DJFM NAO is high, especially in the Northern (high positive) and Southern Europe (high negative). Therefore, higher precipitation in Northern Europe and lower precipitation in Southern Europe are expected in the future. Cross-spectral analysis between precipitation and DJFM NAO time series in three different locations in Europe revealed the best coherence in a dominant cycle between 3 and 4 years. Finally, the maximum drought period in terms of consecutive months with drought is examined in these three locations. The results can be used for strategic planning in a sustainable water resources management plan, since there is a link between drought events and NAO.

  14. Up-Regulation of CYP2C19 Expression by BuChang NaoXinTong via PXR Activation in HepG2 Cells.

    Directory of Open Access Journals (Sweden)

    Hong Sun

    Full Text Available Cytochrome P450 2C19 (CYP2C19 is an important drug-metabolizing enzyme (DME, which is responsible for the biotransformation of several kinds of drugs such as proton pump inhibitors, platelet aggregation inhibitors and antidepressants. Previous studies showed that Buchang NaoXinTong capsules (NXT increased the CYP2C19 metabolic activity in vitro and enhanced the antiplatelet effect of clopidogrel in vivo. However, the underlying molecular mechanism remained unclear. In the present study, we examined whether Pregnane X receptor (PXR plays a role in NXT-mediated regulation of CYP2C19 expression.We applied luciferase assays, real-time quantitative PCR (qPCR, Western blotting and cell-based analysis of metabolic activity experiments to investigate the NXT regulatory effects on the CYP2C19 promoter activity, the mRNA/ protein expression and the metabolic activity.Our results demonstrated that NXT significantly increased the CYP2C19 promoter activity when co-transfected with PXR in HepG2 cells. Mutations in PXR responsive element abolished the NXT inductive effects on the CYP2C19 promoter transcription. Additionally, NXT incubation (150 and 250μg/mL also markedly up-regulated endogenous CYP2C19 mRNA and protein levels in PXR-transfected HepG2 cells. Correspondingly, NXT leaded to a significant enhancement of the CYP2C19 catalytic activity in PXR-transfected HepG2 cells.In summary, this is the first study to suggest that NXT could induce CYP2C19 expression via PXR activation.

  15. The North Atlantic Oscillation: variability and interactions with the North Atlantic ocean and Artic sea ice

    Energy Technology Data Exchange (ETDEWEB)

    Jung, T

    2000-07-01

    The North Atlantic oscillation (NAO) represents the dominant mode of atmospheric variability in the North Atlantic region and describes the strengthening and weakening of the midlatitude westerlies. In this study, variability of the NAO during wintertime and its relationship to the North Atlantic ocean and Arctic sea ice is investigated. For this purpose, observational data are analyzed along with integrations of models for the Atlantic ocean, Arctic sea ice, and the coupled global climate system. From a statistical point of view, the observed NAO index shows unusually high variance on interdecadal time scales during the 20th century. Variability on other time scales is consistent with realizations of random processes (''white noise''). Recurrence of wintertime NAO anomalies from winter-to-winter with missing signals during the inbetween nonwinter seasons is primarily associated with interdecadal variability of the NAO. This recurrence indicates that low-frequency changes of the NAO during the 20th century were in part externally forced. (orig.)

  16. The North Atlantic Oscillation: variability and interactions with the North Atlantic ocean and Artic sea ice

    Energy Technology Data Exchange (ETDEWEB)

    Jung, T.

    2000-07-01

    The North Atlantic oscillation (NAO) represents the dominant mode of atmospheric variability in the North Atlantic region and describes the strengthening and weakening of the midlatitude westerlies. In this study, variability of the NAO during wintertime and its relationship to the North Atlantic ocean and Arctic sea ice is investigated. For this purpose, observational data are analyzed along with integrations of models for the Atlantic ocean, Arctic sea ice, and the coupled global climate system. From a statistical point of view, the observed NAO index shows unusually high variance on interdecadal time scales during the 20th century. Variability on other time scales is consistent with realizations of random processes (''white noise''). Recurrence of wintertime NAO anomalies from winter-to-winter with missing signals during the inbetween nonwinter seasons is primarily associated with interdecadal variability of the NAO. This recurrence indicates that low-frequency changes of the NAO during the 20th century were in part externally forced. (orig.)

  17. Observed linkages between the northern annular mode/North Atlantic Oscillation, cloud incidence, and cloud radiative forcing

    Science.gov (United States)

    Li, Ying; Thompson, David W. J.; Huang, Yi; Zhang, Minghong

    2014-03-01

    The signature of the northern annular mode/North Atlantic Oscillation (NAM/NAO) in the vertical and horizontal distribution of tropospheric cloudiness is investigated in CloudSat and CALIPSO data from June 2006 to April 2011. During the Northern Hemisphere winter, the positive polarity of the NAM/NAO is marked by increases in zonally averaged cloud incidence north of ~60°N, decreases between ~25 and 50°N, and increases in the subtropics. The tripolar-like anomalies in cloud incidence associated with the NAM/NAO are largest over the North Atlantic Ocean basin/Middle East and are physically consistent with the NAM/NAO-related anomalies in vertical motion. Importantly, the NAM/NAO-related anomalies in tropospheric cloud incidence lead to significant top of atmosphere cloud radiative forcing anomalies that are comparable in amplitude to those associated with the NAM/NAO-related temperature anomalies. The results provide observational evidence that the most prominent pattern of Northern Hemisphere climate variability is significantly linked to variations in cloud radiative forcing. Implications for two-way feedback between extratropical dynamics and cloud radiative forcing are discussed.

  18. Pre-Schoolers' Interest and Caring Behaviour around a Humanoid Robot

    Science.gov (United States)

    Ioannou, Andri; Andreou, Emily; Christofi, Maria

    2015-01-01

    This exploratory case study involved a humanoid robot, NAO, and four pre-schoolers. NAO was placed in an indoor playground together with other toys and appeared as a peer who played, talked, danced and said stories. Analysis of video recordings focused on children's behaviour around NAO and how the robot gained children's attention and…

  19. The Spatial and Temporal Variability of the North Atlantic Oscillation Recorded in Ice Core Major Ion Time Series

    Science.gov (United States)

    Wawrzeniak, T. L.; Wake, C. P.; Fischer, H.; Fisher, D. A.; Schwikowski, M.

    2006-05-01

    The North Atlantic Oscillation represents a significant mode of atmospheric variability for the Arctic and sub- Artic climate system. Developing a longer-term record of the spatial and temporal variability of the NAO could improve our understanding of natural climate variability in the region. Previous work has shown a significant relationship between Greenland ice core records and the NAO. Here, we have compared sea-salt and dust records from nine ice cores around the Arctic region to sea level pressure and NAO indices to evaluate the extent to which these ice cores can be used to reconstruct the NAO.

  20. 3D coordination polymers with nitrilotriacetic and 4,4'-bipyridyl mixed ligands: structural variation based on dinuclear or tetranuclear subunits assisted by Na-O and/or O-H...O interactions.

    Science.gov (United States)

    Lü, Xing-Qiang; Jiang, Ji-Jun; Chen, Chun-Long; Kang, Bei-Sheng; Su, Cheng-Yong

    2005-06-27

    The reactions of Cu(II) with the mixed nitrilotriacetic acid (H3NTA) and 4,4'-bipyridyl (4,4'-bpy) ligands in different metal-to-ligand ratios in the presence of NaOH and NaClO4 afforded two complexes, Na3[Cu2(NTA)2(4,4'-bpy)]ClO4 x 5H2O (1) and [Cu2(NTA) (4,4'-bpy)2]ClO4 x 4H2O (2). The two complexes have been characterized by elemental analysis, IR, XRD, and single-crystal X-ray diffraction. 1 contains a basic doubly negatively charged [Cu2(NTA)2(4,4'-bpy)]2- dinuclear unit which was further assembled via multiple Na-O and O-H...O interactions into a three-dimensional (3D) pillared-layer structure. 2 features a two-dimensional (2D) undulated brick-wall architecture containing a basic doubly positively charged [Cu4(NTA)2(4,4'-bpy)2]2+ tetranuclear unit. The 2D network possesses large cavities hosting guest molecules and was further assembled via O-H...O hydrogen bonds into a 3D structure with several channels running in different directions.

  1. Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos

    Directory of Open Access Journals (Sweden)

    Ricardo Trigo

    2002-06-01

    Full Text Available THE IMPACT OF THE NORTH ATLANTIC OSCILLATION ON THE EUROPEAN CLIMATE AND RIVER FLOW OF THREE MAJOR IBERIAN RIVERS – The North Atlantic Oscillation (NAO is the most dominant mode of atmospheric circulation variability over the entire Northern Hemisphere (NH and has recently been shown to be related to climate over large regions of the NH, in particular, over the European and North American continents. Here, a multivariable analysis of the influence ofthe NAO on the climate of the North Atlantic and European sectors is presented using the 40 year (1958-97 reanalysis data set from National Centres for Environmental Prediction. Using high and low NAO index composites, anomaly fields of climate variables are then interpreted based on physical mechanisms associated with the anomalous mean flow (characterised by the surface wind field and theanomalous eddy activity (characterised by the surface vorticity and the 500hPa storm track fields. It is shown that NAO-related temperature patterns are mainly controlled by the advection of heat by the anomalous mean flow. However, asymmetries between minimum and maximum temperatures, and more significantly, between positive and negative phases of NAO imply the importance of a different mechanism, namely the modulation of short wave and long wave radiation by cloud cover variations associated with the NAO. Furthermore, NAO influence over two different precipitation-related variables, namely, precipitation rate and precipitable water display different patterns. Precipitable water is shown to be strongly related to the corresponding anomaly fields of temperature while precipitation rate appears to be controlled by the surface vorticity field and associated strength of the tropospheric synoptic activity. Finally, we have assessed the impact of the NAO on winter river flow regimes for several different Portuguese rivers, including the three main international Iberian rivers, the Douro (north, the Tagus (centre and

  2. The influence of sea surface temperature anomalies on low-frequency variability of the North Atlantic Oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Manganello, Julia V. [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States)

    2008-05-15

    The influence of sea surface temperature anomalies (SSTA) on multi-year persistence of the North Atlantic Oscillation (NAO) during the second half of the twentieth century is investigated using the Center for Ocean-Land-Atmosphere Studies (COLA) Atmospheric GCM (AGCM) with an emphasis on isolating the geographic location of the SSTA that produce this influence. The present study focuses on calculating the atmospheric response to the SSTA averaged over 1988-1995 (1961-1968) corresponding to the observed period of strong persistence of the positive (negative) phase of the decadal NAO. The model response to the global 1988-1995 average SSTA shows a statistically significant large-scale pattern characteristic of the positive phase of the NAO. Forcing with the global 1961-1968 average SSTA generates a NAO of the opposite polarity compared to observations. However, all large-scale features both in the model and observations during this period are weaker in magnitude and less significant compared to 1988-1995. Additional idealized experiments show that over the northern center of the NAO the non-linear component of the forced response appears to be quite important and acts to enhance the positive NAO signal. On the other hand, over the southern center where the model response is the strongest, it is also essentially linear. The 1988-1995 average SSTA restricted to the western tropical Pacific region produce a positive NAO remarkably similar in structure but stronger in magnitude than the model response to the global and tropical Indo-Pacific 1988-1995 forcing. A 200-hPa geopotential height response in these experiments shows a positive anomaly over the southern center of the NAO embedded in the Rossby wave trains propagating from the western tropical Pacific. Indian Ocean SSTA lead to much weaker positive NAO primarily through the effect on its northern center. SST forcing confined to the North Atlantic north of equator does not produce a response statistically different

  3. Regional Famine Patterns of The Last Millennium as Influenced by Aggregated Climate Teleconnections

    Science.gov (United States)

    Santoro, Michael Melton

    Famine is the result of a complex set of environmental and social factors. Climate conditions are established as environmental factors contributing to famine occurrence, often through teleconnective patterns. This dissertation is designed to investigate the combined influence on world famine patterns of teleconnections, specifically the North Atlantic Oscillation (NAO), Southern Oscillation (SO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), or regional climate variations such as the South Asian Summer Monsoon (SASM). The investigation is three regional case studies of famine patterns specifically, Egypt, the British Isles, and India. The first study (published in Holocene) employs the results of a Principal Component Analysis (PCA) yielding a SO-NAO eigenvector to predict major Egyptian famines between AD 1049-1921. The SO-NAO eigenvector (1) successfully discriminates between the 5-10 years preceding a famine and the other years, (2) predicts eight of ten major famines, and (3) correctly identifies fifty out of eighty events (63%) of food availability decline leading up to major famines. The second study investigates the impact of the NAO, PDO, SO, and AMO on 63 British Isle famines between AD 1049 and 1914 attributed to climate causes in historical texts. Stepwise Regression Analysis demonstrates that the 5-year lagged NAO is the primary teleconnective influence on famine patterns; it successfully discriminates 73.8% of weather-related famines in the British Isles from 1049 to 1914. The final study identifies the aggregated influence of the NAO, SO, PDO, and SASM on 70 Indian famines from AD 1049 to 1955. PCA results in a NAO-SOI vector and SASM vector that predicts famine conditions with a positive NAO and negative SO, distinct from the secondary SASM influence. The NAO-famine relationship is consistently the strongest; 181 of 220 (82%) of all famines occurred during positive NAO years. Ultimately, the causes of famine are complex

  4. Terrestrial ecological responses of climate change in the Northern hemisphere

    International Nuclear Information System (INIS)

    Forchhammer, M.C.

    2001-01-01

    Focusing on the single most important atmospheric phenomenon in the Northern hemisphere, the North Atlantic Oscillation (NAO), the author reviews the recent studies coupling the NAO with the ecology of a wide range of terrestrial organisms. In particular, the author focuses on low variations in the NAO affect phenotypic variation in life history Traits and, ultimately, dynamics of populations and of interacting species. (LN)

  5. North Atlantic atmospheric and ocean inter-annual variability over the past fifty years - Dominant patterns and decadal shifts

    Science.gov (United States)

    Hauser, Tristan; Demirov, Entcho; Zhu, Jieshun; Yashayaev, Igor

    2015-03-01

    The atmosphere and ocean of the North Atlantic have undergone significant changes in the past century. To understand these changes, their mechanisms, and their regional implications requires a quantitative understanding of processes in the coupled ocean and atmosphere system. Central to this understanding is the role played by the dominant patterns of ocean and atmospheric variability which define coherent variations in physical characteristics over large areas. Cluster analysis is used in this article to identify the patterns of the North Atlantic atmospheric variability in the subseasonal and interannual spectral intervals. Four dominant subseasonal weather regimes are defined using Bayesian Gaussian mixture models. All correlation patterns of the Sea Level Pressure (SLP) anomalies with the membership probability time series for the weather regimes show similarities with the dipole structure typical for the North Atlantic Oscillation (NAO). The SLP patterns of two of the regimes represent the opposite phases NAO+ and NAO-. The two other weather regimes, the Atlantic Ridge (AR) and Scandinavian-Greenland dipole (SG), have dipole spatial structures with the northern and southern centers of action shifted with respect to the NAO pattern. These two patterns define blocking structures over Scandinavia and near the southern tip of Greenland, respectively. The storm tracks typical for the four regimes resemble the well known paths for positive/negative phases of NAO for the NAO+/NAO- weather regimes, and paths influenced by blocking off the south Greenland tip for AR and over Scandinavia for SG. The correlation patterns of momentum and heat fluxes to the ocean for the four regimes have tripole structures with positive (warm) downward heat flux anomalies over the Subpolar North Atlantic (SPNA) for the NAO- and the AR and negative heat flux anomalies over the SPNA for the NAO+. The downward heat flux anomalies associated with the SG are negative over the Labrador Sea and

  6. Synthesis and electrochemical characterization of palladium-based cathode catalysts, resistant to the presence of methanol; Sintesis y caracterizacion electroquimica de catalizadores catodicos base paladio, resistentes a la presencia de metanol

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, Jose J. [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)] e-mail: jsalvador@cinvestav.mx; Collins, Virginia H. [Centro de Investigacion en Materiales Avanzados, Chihuahua, Chihuahua (Mexico); Solorza Feria, Omar [Centro de Investigacion y de Estudios Avanzados del IPN, Mexico D.F. (Mexico)

    2009-09-15

    This work presents the synthesis and characterization of palladium-based electrocatalysts (PdSn and PdPtSn) prepared with the salt-reduction method for oxygen reduction reaction (ORR). The compounds obtained are characterized by sweep electron microscopy, electron transmission microscopy and x-ray diffraction of powder. The electrocatalysts obtained had particle sizes less than 10 nm. The evaluation of the catalytic activity of the catalysts was performed using cyclic voltametry and rotating disc electrode. These experiments were conducted in an H{sub 2}SO{sub 4} 0.5 M solution with different methanol concentrations. The presence of methanol improved the catalytic activity of PdSn, but did not show any effect on the PdPtSn alloy. The performance of the DMFC mono cell using PdPtSn as a cathode showed a potential of 10 mW cm{sup -2} at 50 degrees Celsius. [Spanish] En este trabajo se presenta la sintesis y caracterizacion de electrocatalizadores de base Paladio (PdSn y PdPtSn) preparados mediante el metodo de reduccion de sales, para la reaccion de reduccion de oxigeno (RRO). Los compuestos obtenidos se caracterizaron por microscopia electronica de barrido, microscopia electronica de transmision y difraccion de rayos X de polvos. Los electrocatalizadores obtenidos presentaron un tamano de particula menores a 10 nm. La evaluacion de la actividad catalitica de los catalizadores se llevo a cabo mediante voltametria Ciclica y electrodo de disco rotatorio, estos experimentos fueron realizados en una solucion de H{sub 2}SO{sub 4} 0.5 M con diferentes concentraciones de metanol. La presencia de metanol mejoro la actividad catalitica de PdSn, pero no mostro ningun efecto sobre la aleacion PdPtSn. El desempeno de la monocelda de DMFC usando como catodo PdPtSn, mostro una potencia de 10 mW cm{sup -2} a 50 grados centigrados.

  7. Forest productivity in southwestern Europe is controlled by coupled North Atlantic and Atlantic Multidecadal Oscillations.

    Science.gov (United States)

    Madrigal-González, Jaime; Ballesteros-Cánovas, Juan A; Herrero, Asier; Ruiz-Benito, Paloma; Stoffel, Markus; Lucas-Borja, Manuel E; Andivia, Enrique; Sancho-García, Cesar; Zavala, Miguel A

    2017-12-20

    The North Atlantic Oscillation (NAO) depicts annual and decadal oscillatory modes of variability responsible for dry spells over the European continent. The NAO therefore holds a great potential to evaluate the role, as carbon sinks, of water-limited forests under climate change. However, uncertainties related to inconsistent responses of long-term forest productivity to NAO have so far hampered firm conclusions on its impacts. We hypothesize that, in part, such inconsistencies might have their origin in periodical sea surface temperature anomalies in the Atlantic Ocean (i.e., Atlantic Multidecadal Oscillation, AMO). Here we show strong empirical evidence in support of this hypothesis using 120 years of periodical inventory data from Iberian pine forests. Our results point to AMO + NAO + and AMO - NAO - phases as being critical for forest productivity, likely due to decreased winter water balance and abnormally low winter temperatures, respectively. Our findings could be essential for the evaluation of ecosystem functioning vulnerabilities associated with increased climatic anomalies under unprecedented warming conditions in the Mediterranean.

  8. Inter-Relationship Between Subtropical Pacific Sea Surface Temperature, Arctic Sea Ice Concentration, and the North Atlantic Oscillation in Recent Summers and Winters

    Science.gov (United States)

    Lim, Young-Kwon; Cullather, Richard I.; Nowicki, Sophie M.; Kim, Kyu-Myong

    2017-01-01

    The inter-relationship between subtropical western-central Pacific sea surface temperatures (STWCPSST), sea ice concentration in the Beaufort Sea (SICBS), and the North Atlantic Oscillation (NAO) are investigated for the last 37 summers and winters (1980-2016). Lag-correlation of the STWCPSST×(-1) in spring with the NAO phase and SICBS in summer increases over the last two decades, reaching r = 0.4-0.5 with significance at 5 percent, while winter has strong correlations in approximately 1985-2005. Observational analysis and the atmospheric general circulation model experiments both suggest that STWCPSST warming acts to increase the Arctic geopotential height and temperature in the following season. This atmospheric response extends to Greenland, providing favorable conditions for developing the negative phase of the NAO. SIC and surface albedo tend to decrease over the Beaufort Sea in summer, linked to the positive surface net shortwave flux. Energy balance considering radiative and turbulent fluxes reveal that available energy that can heat surface is larger over the Arctic and Greenland and smaller over the south of Greenland, in response to the STWCPSST warming in spring. XXXX Arctic & Atlantic: Positive upper-level height/T anomaly over the Arctic and Greenland, and a negative anomaly over the central-eastern Atlantic, resembling the (-) phase of the NAO. Pacific: The negative height/T anomaly over the mid-latitudes, along with the positive anomaly over the STWCP, where 1degC warming above climatology is prescribed. Discussion: It is likely that the Arctic gets warm and the NAO is in the negative phase in response to the STWCP warming. But, there are other factors (e.g., internal variability) that contribute to determination of the NAO phase: not always the negative phase of the NAO in the event of STWCP warming (e.g.: recent winters and near neutral NAO in 2017 summer).

  9. Contrasting spatial structures of Atlantic Multidecadal Oscillation between observations and slab ocean model simulations

    Science.gov (United States)

    Sun, Cheng; Li, Jianping; Kucharski, Fred; Xue, Jiaqing; Li, Xiang

    2018-04-01

    The spatial structure of Atlantic multidecadal oscillation (AMO) is analyzed and compared between the observations and simulations from slab ocean models (SOMs) and fully coupled models. The observed sea surface temperature (SST) pattern of AMO is characterized by a basin-wide monopole structure, and there is a significantly high degree of spatial coherence of decadal SST variations across the entire North Atlantic basin. The observed SST anomalies share a common decadal-scale signal, corresponding to the basin-wide average (i. e., the AMO). In contrast, the simulated AMO in SOMs (AMOs) exhibits a tripole-like structure, with the mid-latitude North Atlantic SST showing an inverse relationship with other parts of the basin, and the SOMs fail to reproduce the observed strong spatial coherence of decadal SST variations associated with the AMO. The observed spatial coherence of AMO SST anomalies is identified as a key feature that can be used to distinguish the AMO mechanism. The tripole-like SST pattern of AMOs in SOMs can be largely explained by the atmosphere-forced thermodynamics mechanism due to the surface heat flux changes associated with the North Atlantic Oscillation (NAO). The thermodynamic forcing of AMOs by the NAO gives rise to a simultaneous inverse NAO-AMOs relationship at both interannual and decadal timescales and a seasonal phase locking of the AMOs variability to the cold season. However, the NAO-forced thermodynamics mechanism cannot explain the observed NAO-AMO relationship and the seasonal phase locking of observed AMO variability to the warm season. At decadal timescales, a strong lagged relationship between NAO and AMO is observed, with the NAO leading by up to two decades, while the simultaneous correlation of NAO with AMO is weak. This lagged relationship and the spatial coherence of AMO can be well understood from the view point of ocean dynamics. A time-integrated NAO index, which reflects the variations in Atlantic meridional overturning

  10. Forest productivity in southwestern Europe is controlled by coupled North Atlantic and Atlantic Multidecadal Oscillations

    OpenAIRE

    Madrigal Gonzalez, Jaime; Ballesteros Canovas, Juan Antonio; Herrero, Asier; Ruiz-Benito, Paloma; Stoffel, Markus; Lucas-Borja, Manuel E.; Andivia, Enrique; Sancho-García, Cesar; Zavala, Miguel A.

    2017-01-01

    The North Atlantic Oscillation (NAO) depicts annual and decadal oscillatory modes of variability responsible for dry spells over the European continent. The NAO therefore holds a great potential to evaluate the role, as carbon sinks, of water-limited forests under climate change. However, uncertainties related to inconsistent responses of long-term forest productivity to NAO have so far hampered firm conclusions on its impacts. We hypothesize that, in part, such inconsistencies might have the...

  11. Local and regional effects of large scale atmospheric circulation patterns on winter wind power output in Western Europe

    Science.gov (United States)

    Zubiate, Laura; McDermott, Frank; Sweeney, Conor; O'Malley, Mark

    2014-05-01

    Recent studies (Brayshaw, 2009, Garcia-Bustamante, 2010, Garcia-Bustamante, 2013) have drawn attention to the sensitivity of wind speed distributions and likely wind energy power output in Western Europe to changes in low-frequency, large scale atmospheric circulation patterns such as the North Atlantic Oscillation (NAO). Wind speed variations and directional shifts as a function of the NAO state can be larger or smaller depending on the North Atlantic region that is considered. Wind speeds in Ireland and the UK for example are approximately 20 % higher during NAO + phases, and up to 30 % lower during NAO - phases relative to the long-term (30 year) climatological means. By contrast, in southern Europe, wind speeds are 15 % lower than average during NAO + phases and 15 % higher than average during NAO - phases. Crucially however, some regions such as Brittany in N.W. France have been identified in which there is negligible variability in wind speeds as a function of the NAO phase, as observed in the ERA-Interim 0.5 degree gridded reanalysis database. However, the magnitude of these effects on wind conditions is temporally and spatially non-stationary. As described by Comas-Bru and McDermott (2013) for temperature and precipitation, such non-stationarity is caused by the influence of two other patterns, the East Atlantic pattern, (EA), and the Scandinavian pattern, (SCA), which modulate the position of the NAO dipole. This phenomenon has also implications for wind speeds and directions, which has been assessed using the ERA-Interim reanalysis dataset and the indices obtained from the PC analysis of sea level pressure over the Atlantic region. In order to study the implications for power production, the interaction of the NAO and the other teleconnection patterns with local topography was also analysed, as well as how these interactions ultimately translate into wind power output. The objective is to have a better defined relationship between wind speed and power

  12. Shallow and deep landslides induced by rainfall in the Lisbon region (Portugal: assessment of relationships with the North Atlantic Oscillation

    Directory of Open Access Journals (Sweden)

    J. L. Zêzere

    2005-01-01

    Full Text Available The aim of this study is to assess the impact of the North Atlantic Oscillation (NAO on both the winter precipitation and the temporal occurrence of different landslide types in Portugal. The analysis is applied to five sample areas located just north of Lisbon, the capital of Portugal. These sites are particularly relevant because actual dates of most of the recent landslide events are known but also because the landslides occurred in a suburban area with growing urbanization pressure. Results show that the large inter-annual variability of winter precipitation observed in western Iberia, i.e. Portugal and parts of Spain, is largely modulated by the NAO mode. In particular, precipitation falling in Portugal between November and March presents a correlation coefficient of R=–0.66 with the NAO index. Precipitation distribution for the reference rain gauge in the study area reveals that the probability of a wet month to occur is much higher for low NAO index composites than for the corresponding high NAO index composite. It is shown that this control, exerted by NAO on the precipitation regime, is related to corresponding changes in the associated activity of North-Atlantic storm tracks that affect the western Iberia. Landslide activity in the study area is related to both intense, short duration precipitation events (1–15 days and long-lasting rainfall episodes (1–3 months. The former events trigger shallow translational slides while the later episodes are usually associated with deeper and larger slope movements. This second group of landslides is shown to be statistically associated with the 3-month average of the NAO index.

  13. Serum apolipoproteins in relation to intakes of fish in population of Arkhangelsk County

    Directory of Open Access Journals (Sweden)

    Petrenya Natalia

    2012-06-01

    Full Text Available Abstract Background Diets rich in omega-3 fatty acids and low in saturated fat were found beneficially associated with blood lipids and cardio-vascular health. Lean reindeer meet and local cold water white-fish species high in omega-3 are among the main sources of nutrients in the rural area of the Nenets Autonomous Okrug (NAO in Russia and are not normally consumed by the urban population from the same region. The aims of the study were firstly, to compare serum lipid profiles of residents of urban (Arkhangelsk city and rural (NAO regions of Arkhangelsk County, and secondly, to investigate the effects of fish consumption on the predictor of cardiovascular events apolipoprotein (Apo B/ApoA-I ratio in these populations. Methods A cross-sectional study conducted in Arkhangelsk County, Russia. Sample size of 249 adults: 132 subjects from Arkhangelsk city, aged 21–70 and 117 subject (87% Ethnic Nenets from NAO, aged 18–69. Results We observed more favorable lipid levels in NAO compared to Arkhangelsk participants. Age-adjusted geometric means of ApoB/ApoA-I ratio were 1.02 and 0.98 in men and women from Arkhangelsk; 0.84 and 0.91 in men and women from NAO respectively. Age and consumption of animal fat were positively associated with ApoB/ApoA-I ratio in women (pooled samples from Arkhangelsk and NAO. Body mass index and low levels of physical activity were positively associated with ApoB/ApoA-I ratio in men (pooled samples from Arkhangelsk and NAO. Reported oily fish consumption was not significantly correlated with ApoB/ApoA-I ratio. Conclusion The population sample from rural NAO, consisting largely of the indigenous Arctic population Nenets with healthier dietary sources, had a relatively less atherogenic lipid profile compared to the urban Arkhangelsk group. Fish consumption had no effect on apolipoproteins profile.

  14. Crystal Structures of Nitroalkane Oxidase: Insights into the Reaction Mechanism of a Covalent Complex of the Flavoenzyme Trapped During Turnover

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal,A.; Valley, M.; Fitzpatrick, P.; Orville, A.

    2006-01-01

    Nitroalkane oxidase (NAO) from Fusarium oxysporum catalyzes the oxidation of neutral nitroalkanes to the corresponding aldehydes or ketones with the production of H2O2 and nitrite. The flavoenzyme is a new member of the acyl-CoA dehydrogenase (ACAD) family, but it does not react with acyl-CoA substrates. We present the 2.2 Angstroms resolution crystal structure of NAO trapped during the turnover of nitroethane as a covalent N5-FAD adduct (ES*). The homotetrameric structure of ES* was solved by MAD phasing with 52 Se-Met sites in an orthorhombic space group. The electron density for the N5-(2-nitrobutyl)-1,5-dihydro-FAD covalent intermediate is clearly resolved. The structure of ES* was used to solve the crystal structure of oxidized NAO at 2.07 Angstroms resolution. The c axis for the trigonal space group of oxidized NAO is 485 Angstroms, and there are six subunits (11/2 holoenzymes) in the asymmetric unit. Four of the active sites contain spermine (EI), a weak competitive inhibitor, and two do not contain spermine (E{sup ox}). The active-site structures of E{sup ox}, EI, and ES* reveal a hydrophobic channel that extends from the exterior of the protein and terminates at Asp402 and the N5 position on the re face of the FAD. Thus, Asp402 is in the correct position to serve as the active-site base, where it is proposed to abstract the {alpha} proton from neutral nitroalkane substrates. The structures for NAO and various members of the ACAD family overlay with root-mean-square deviations between 1.7 and 3.1 Angstroms. The homologous region typically spans more than 325 residues and includes Glu376, which is the active-site base in the prototypical member of the ACAD family. However, NAO and the ACADs exhibit differences in hydrogen-bonding patterns between the respective active-site base, substrate molecules, and FAD. These likely differentiate NAO from the homologues and, consequently, are proposed to result in the unique reaction mechanism of NAO.

  15. The Influence of the North Atlantic Oscillation on Tropospheric Distributions of Ozone and Carbon Monoxide.

    Science.gov (United States)

    Knowland, K. E.; Doherty, R. M.; Hodges, K.

    2015-12-01

    The influence of the North Atlantic Oscillation (NAO) on the tropospheric distributions of ozone (O3) and carbon monoxide (CO) has been quantified. The Monitoring Atmospheric Composition and Climate (MACC) Reanalysis, a combined meteorology and composition dataset for the period 2003-2012 (Innes et al., 2013), is used to investigate the composition of the troposphere and lower stratosphere in relation to the location of the storm track as well as other meteorological parameters over the North Atlantic associated with the different NAO phases. Cyclone tracks in the MACC Reanalysis compare well to the cyclone tracks in the widely-used ERA-Interim Reanalysis for the same 10-year period (cyclone tracking performed using the tracking algorithm of Hodges (1995, 1999)), as both are based on the European Centre for Medium-Range Weather Forecasts' (ECMWF) Integrated Forecast System (IFS). A seasonal analysis is performed whereby the MACC reanalysis meteorological fields, O3 and CO mixing ratios are weighted by the monthly NAO index values. The location of the main storm track, which tilts towards high latitudes (toward the Arctic) during positive NAO phases to a more zonal location in the mid-latitudes (toward Europe) during negative NAO phases, impacts the location of both horizontal and vertical transport across the North Atlantic and into the Arctic. During positive NAO seasons, the persistence of cyclones over the North Atlantic coupled with a stronger Azores High promotes strong horizontal transport across the North Atlantic throughout the troposphere. In all seasons, significantly more intense cyclones occur at higher latitudes (north of ~50°C) during the positive phase of the NAO and in the southern mid-latitudes during the negative NAO phase. This impacts the location of stratospheric intrusions within the descending dry airstream behind the associated cold front of the extratropical cyclone and the venting of low-level pollution up into the free troposphere within

  16. Evaluation of catalytic ferrispinel MFe{sub 2}O{sub 4} (M = Cu, Co, Mn and Ni) in transesterification reaction; Avaliacao catalitica de ferroespinelios MFe{sub 2}O{sub 4} (M = Cu, Co, Mn e Ni) em reacao de transesterificacao visando obtencao de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Kleberson Ricardo de Oliveira; Dantas, Joelda; Costa, Ana Cristina Figueiredo de Melo; Silva, Adriano Sant' Ana, E-mail: klebersonric@usp.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Cornejo, Daniel Reinaldo [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica

    2014-07-01

    Among the existing biofuels, biodiesel has achieved great economic and technological, for its potential to replace petroleum diesel and being biodegradable, have low emission of gaseous and be from renewable sources highlighted. In this context we propose to evaluate the performance of ferrispinel type MFe{sub 2}O{sub 4}, where M represents divalent metals (Cu, Co, Ni and Mn) in methyl transesterification reaction of soybean oil. The ferrispinel were synthesized by combustion reaction and characterized by XRD, FTIR and magnetic measurements. The results indicate that the synthesis is conducive to the production of ferrispinel with magnetization values ranging from 11.0 to 58.0 emu/g. The conversion values were 53; 55; 57 and 52 %, respectively, concluding that the type of divalent metal affects the morphology and hence the catalytic conversion. (author)

  17. The changing relationship between the December North Atlantic Oscillation and the following February East Asian trough before and after the late 1980s

    Science.gov (United States)

    Feng, Guolin; Zou, Meng; Qiao, Shaobo; Zhi, Rong; Gong, Zhiqiang

    2018-03-01

    This study investigates the changing relationship between the December North Atlantic Oscillation (NAO) and the following February East Asian trough (EAT) throughout the past 60 years. We found that the relationship between the December NAO and the following February EAT is significantly enhanced after the late 1980s compared with the period before the late 1980s. The changing relationship mainly results from the enhanced relationship between the December NAO and the following February North Atlantic mid-latitudes' sea surface temperature (SST) anomalies (NAMA) during the same period. During the period after the late 1980s, the persistent positive (negative) NAO pattern from December to the following January contributes to a positive (negative) NAMA, which reaches its maximum magnitude in the following February and excites an anomalous wave train along the North Atlantic and northern Eurasia, and significantly impacts the EAT. During the period before the late 1980s, the positive (negative) NAO pattern during December cannot persist into the following January, and the related positive (negative) NAMA is insignificant during the following February, causing the response of the simultaneous EAT to be insignificant as well. Moreover, there exists a significant impact of the December NAO on the December-January NAMA after the late 1980s, while the December-January NAMA is relatively less affected by the December NAO before the late 1980s. As a result, the simultaneous response of the atmospheric circulation anomalies to the December-January NAMA are evident before the late 1980s, and the positive (negative) NAMA can excite an anomalous wave train along the North Atlantic and northern Eurasia and significantly deepen (shallow) the downstream EAT. By contrast, after involving a feature of atmosphere forcing of SST, the simultaneous feedback of the December-January NAMA on EAT is significantly decreased after the 1980s.

  18. Challenging a 15-year-old claim: The North Atlantic Oscillation index as a predictor of spring migration phenology of birds.

    Science.gov (United States)

    Haest, Birgen; Hüppop, Ommo; Bairlein, Franz

    2018-04-01

    Many migrant bird species that breed in the Northern Hemisphere show advancement in spring arrival dates. The North Atlantic Oscillation (NAO) index is one of the climatic variables that have been most often investigated and shown to be correlated with these changes in spring arrival. Although the NAO is often claimed to be a good predictor or even to have a marked effect on interannual changes in spring migration phenology of Northern Hemisphere breeding birds, the results on relations between spring migration phenology and NAO show a large variety, ranging from no, over weak, to a strong association. Several factors, such as geographic location, migration phase, and the NAO index time window, have been suggested to partly explain these observed differences in association. A combination of a literature meta-analysis, and a meta-analysis and sliding time window analysis of a dataset of 23 short- and long-distance migrants from the constant-effort trapping garden at Helgoland, Germany, however, paints a completely different picture. We found a statistically significant overall effect size of the NAO on spring migration phenology (coefficient = -0.14, SE = 0.054), but this on average only explains 0%-6% of the variance in spring migration phenology across all species. As such, the value and biological meaning of the NAO as a general predictor or explanatory variable for climate change effects on migration phenology of birds, seems highly questionable. We found little to no definite support for previously suggested factors, such as geographic location, migration phenology phase, or the NAO time window, to explain the heterogeneity in correlation differences. We, however, did find compelling evidence that the lack of accounting for trends in both time series has led to strongly inflated (spurious) correlations in many studies (coefficient = -0.13, SE = 0.019). © 2017 John Wiley & Sons Ltd.

  19. Identification of a Hypothetical Protein from Podospora anserina as a Nitroalkane Oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Tormos, Jose R.; Taylor, Alexander B.; Daubner, S. Colette; Hart, P. John; Fitzpatrick, Paul F. (Texas-HSC); (St. Mary)

    2010-08-23

    The flavoprotein nitroalkane oxidase (NAO) from Fusarium oxysporum catalyzes the oxidation of primary and secondary nitroalkanes to their respective aldehydes and ketones. Structurally, the enzyme is a member of the acyl-CoA dehydrogenase superfamily. To date no enzymes other than that from F. oxysporum have been annotated as NAOs. To identify additional potential NAOs, the available database was searched for enzymes in which the active site residues Asp402, Arg409, and Ser276 were conserved. Of the several fungal enzymes identified in this fashion, PODANSg2158 from Podospora anserina was selected for expression and characterization. The recombinant enzyme is a flavoprotein with activity on nitroalkanes comparable to the F. oxysporum NAO, although the substrate specificity is somewhat different. Asp399, Arg406, and Ser273 in PODANSg2158 correspond to the active site triad in F. oxysporum NAO. The k{sub cat}/K{sub M}-pH profile with nitroethane shows a pK{sub a} of 5.9 that is assigned to Asp399 as the active site base. Mutation of Asp399 to asparagine decreases the k{sub cat}/K{sub M} value for nitroethane over 2 orders of magnitude. The R406K and S373A mutations decrease this kinetic parameter by 64- and 3-fold, respectively. The structure of PODANSg2158 has been determined at a resolution of 2.0 {angstrom}, confirming its identification as an NAO.

  20. Protective effects of traditional Chinese medicine formula NaoShuanTong capsule on haemorheology and cerebral energy metabolism disorders in rats with blood stasis.

    Science.gov (United States)

    Liu, Hong; Peng, Yao-Yao; Liang, Feng-Yin; Chen, Si; Li, Pei-Bo; Peng, Wei; Liu, Zhong-Zheng; Xie, Cheng-Shi; Long, Chao-Feng; Su, Wei-Wei

    2014-01-02

    NaoShuanTong capsule (NSTC), an oral traditional Chinese medicine formula, is composed of Pollen Typhae , Radix Paeoniae Rubra , Rhizoma Gastrodiae , Radix Rhapontici and Radix Curcumae . It has been widely used to treat ischemic stroke in clinic for many years in China. In addition to neuronal apoptosis, haemorheology and cerebral energy metabolism disorders also play an important role in the pathogenesis and development of ischemic stroke. The present study was designed to evaluate the in vivo protective effects of NSTC on haemorheology and cerebral energy metabolism disorders in rats with blood stasis. Sixty specific pathogen-free sprague-dawley rats, male only, were randomly divided into six groups (control group, model group, aspirin (100 mg/kg/d) group, NSTC low-dose (400 mg/kg/d) group, NSTC intermediate-dose (800 mg/kg/d) group, NSTC high-dose (1600 mg/kg/d) group) with 10 animals in each. The rats except those in the control group were placed in ice-cold water (0-4 °C) for 5 min during the time interval (4 h) of two adrenaline hydrochloride injections (0.8 mg/kg) to induce blood stasis. After treatment, whole blood viscosity at three shear rates, plasma viscosity and erythrocyte sedimentation rate significantly decreased in NSTC intermediate- and high-dose groups; erythrocyte aggregation index and red corpuscle electrophoresis index significantly decreased in all the three dose NSTC groups. Moreover, treatment with high-dose NSTC could significantly improve Na + -K + adenosine triphosphatase (ATPase) and Ca 2+ ATPase activity, as well as lower lactic acid level in brain tissues. These results demonstrated the protective effects of NSTC on haemorheology and cerebral energy metabolism disorders, which may provide scientific information for the further understanding of mechanism(s) of NSTC as a clinical treatment for ischemic stroke. Furthermore, the protective effects of activating blood circulation as observed in this study might create valuable

  1. An assessment of actual evapotranspiration and soil water deficit in agricultural regions in Europe

    DEFF Research Database (Denmark)

    Kurnik, Blaž; Kajfež-Bogataj, Lučka; Horion, Stéphanie Marie Anne F

    2015-01-01

    ) analysis and the Pearson correlation coefficients (RPearson), we showed that large-scale agricultural droughts are influenced by the recurrence of the North Atlantic Oscillation (NAO) and by the atmospheric blocking. Atmospheric blocking in different months throughout the year and extreme NAO index (mainly...

  2. Sodium and Proton Effects on Inward Proton Transport through Na/K Pumps

    Science.gov (United States)

    Mitchell, Travis J.; Zugarramurdi, Camila; Olivera, J. Fernando; Gatto, Craig; Artigas, Pablo

    2014-01-01

    The Na/K pump hydrolyzes ATP to export three intracellular Na (Nai) as it imports two extracellular K (Ko) across animal plasma membranes. Within the protein, two ion-binding sites (sites I and II) can reciprocally bind Na or K, but a third site (site III) exclusively binds Na in a voltage-dependent fashion. In the absence of Nao and Ko, the pump passively imports protons, generating an inward current (IH). To elucidate the mechanisms of IH, we used voltage-clamp techniques to investigate the [H]o, [Na]o, and voltage dependence of IH in Na/K pumps from ventricular myocytes and in ouabain-resistant pumps expressed in Xenopus oocytes. Lowering pHo revealed that Ho both activates IH (in a voltage-dependent manner) and inhibits it (in a voltage-independent manner) by binding to different sites. Nao effects depend on pHo; at pHo where no Ho inhibition is observed, Nao inhibits IH at all concentrations, but when applied at pHo that inhibits pump-mediated current, low [Na]o activates IH and high [Na]o inhibits it. Our results demonstrate that IH is a property inherent to Na/K pumps, not linked to the oocyte expression environment, explains differences in the characteristics of IH previously reported in the literature, and supports a model in which 1), protons leak through site III; 2), binding of two Na or two protons to sites I and II inhibits proton transport; and 3), pumps with mixed Na/proton occupancy of sites I and II remain permeable to protons. PMID:24940773

  3. Climate impacts of the NAO are sensitive to how the NAO is defined

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Lucie; Huth, Radan

    2015-01-01

    Roč. 119, 3-4 (2015), s. 639-652 ISSN 0177-798X R&D Projects: GA ČR GAP209/10/2265; GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:68378289 ; RVO:67179843 Keywords : North-Atlantic-Oscillation * atmospheric circulation * winter temperature * variability modes * time variations * Icelandic low * precipitation * surface * frequency * Europe Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.433, year: 2015 http://link.springer.com/article/10.1007%2Fs00704-014-1116-0

  4. Interanual variability os solar radiation in Peninsula Iberica; Variabilidad interanual de la radiacion solar en la Peninsula Iberica

    Energy Technology Data Exchange (ETDEWEB)

    Pozo-Vazquez, D.; Tovar-Pescador, J.; Gamiz-Fortis, S.; Esteban-Parra, M.; Castro-Diez, Y.

    2004-07-01

    The NAO climatic phenomenon is the main responsible for the interanual cloud cover variability in Europe. We explore the relationship between the NAO and the solar radiation spatio-temporal variability in Europe during winter. Measured monthly sums of sunshine duration and short-wave downward solar flux reanalysis data have been used. Correlation analysis between the NAO index and the measured sunshine duration shows a maximum positive value (+0.75) over the Iberian Peninsula. Accordingly, solar radiation in this area undergoes an interanual variability that can reach up to 30%, with the derived consequences for a reliable solar energy resources evaluation. (Author)

  5. Reconstructing Late Holocene North Atlantic atmospheric circulation changes using functional paleoclimate networks

    Science.gov (United States)

    Franke, Jasper G.; Werner, Johannes P.; Donner, Reik V.

    2017-11-01

    Obtaining reliable reconstructions of long-term atmospheric circulation changes in the North Atlantic region presents a persistent challenge to contemporary paleoclimate research, which has been addressed by a multitude of recent studies. In order to contribute a novel methodological aspect to this active field, we apply here evolving functional network analysis, a recently developed tool for studying temporal changes of the spatial co-variability structure of the Earth's climate system, to a set of Late Holocene paleoclimate proxy records covering the last two millennia. The emerging patterns obtained by our analysis are related to long-term changes in the dominant mode of atmospheric circulation in the region, the North Atlantic Oscillation (NAO). By comparing the time-dependent inter-regional linkage structures of the obtained functional paleoclimate network representations to a recent multi-centennial NAO reconstruction, we identify co-variability between southern Greenland, Svalbard, and Fennoscandia as being indicative of a positive NAO phase, while connections from Greenland and Fennoscandia to central Europe are more pronounced during negative NAO phases. By drawing upon this correspondence, we use some key parameters of the evolving network structure to obtain a qualitative reconstruction of the NAO long-term variability over the entire Common Era (last 2000 years) using a linear regression model trained upon the existing shorter reconstruction.

  6. Comparison of several climate indices as inputs in modelling of the Baltic Sea runoff

    Energy Technology Data Exchange (ETDEWEB)

    Hanninen, J.; Vuorinen, I. [Turku Univ. (Finland). Archipelaco Research Inst.], e-mail: jari.hanninen@utu.fi

    2012-11-01

    Using Transfer function (TF) models, we have earlier presented a chain of events between changes in the North Atlantic Oscillation (NAO) and their oceanographical and ecological consequences in the Baltic Sea. Here we tested whether other climate indices as inputs would improve TF models, and our understanding of the Baltic Sea ecosystem. Besides NAO, the predictors were the Arctic Oscillation (AO), sea-level air pressures at Iceland (SLP), and wind speeds at Hoburg (Gotland). All indices produced good TF models when the total riverine runoff to the Baltic Sea was used as a modelling basis. AO was not applicable in all study areas, showing a delay of about half a year between climate and runoff events, connected with freezing and melting time of ice and snow in the northern catchment area of the Baltic Sea. NAO appeared to be most useful modelling tool as its area of applicability was the widest of the tested indices, and the time lag between climate and runoff events was the shortest. SLP and Hoburg wind speeds showed largely same results as NAO, but with smaller areal applicability. Thus AO and NAO were both mostly contributing to the general understanding of climate control of runoff events in the Baltic Sea ecosystem. (orig.)

  7. Variability of North Sea pH and CO2 in response to North Atlantic Oscillation forcing

    DEFF Research Database (Denmark)

    Salt, Lesley A.; Thomas, Helmuth; Prowe, Friederike

    2013-01-01

    [1] High biological activity causes a distinct seasonality of surface water pH in the North Sea, which is a strong sink for atmospheric CO2 via an effective shelf pump. The intimate connection between the North Sea and the North Atlantic Ocean suggests that the variability of the CO2 system...... of the North Atlantic Ocean may, in part, be responsible for the observed variability of pH and CO2 in the North Sea. In this work, we demonstrate the role of the North Atlantic Oscillation (NAO), the dominant climate mode for the North Atlantic, in governing this variability. Based on three extensive...... observational records covering the relevant levels of the NAO index, we provide evidence that the North Sea pH and CO2 system strongly responds to external and internal expressions of the NAO. Under positive NAO, the higher rates of inflow of water from the North Atlantic Ocean and the Baltic outflow lead...

  8. Identification of entomopathogenic nematodes and symbiotic bacteria from Nam Nao National Park in Thailand and larvicidal activity of symbiotic bacteria against Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Yooyangket, Temsiri; Muangpat, Paramaporn; Polseela, Raxsina; Tandhavanant, Sarunporn; Thanwisai, Aunchalee; Vitta, Apichat

    2018-01-01

    Entomopathogenic nematodes (EPNs) that are symbiotically associated with Xenorhabdus and Photorhabdus bacteria can kill target insects via direct infection and toxin action. There are limited reports identifying such organisms in the National Park of Thailand. Therefore, the objectives of this study were to identify EPNs and symbiotic bacteria from Nam Nao National Park, Phetchabun Province, Thailand and to evaluate the larvicidal activity of bacteria against Aedes aegypti and Ae. albopictus. A total of 12 EPN isolates belonging to Steinernema and Heterorhabditis were obtained form 940 soil samples between February 2014 and July 2016. EPNs were molecularly identified as S. websteri (10 isolates) and H. baujardi (2 isolates). Symbiotic bacteria were isolated from EPNs and molecularly identified as P. luminescens subsp. akhurstii (13 isolates), X. stockiae (11 isolates), X. vietnamensis (2 isolates) and X. japonica (1 isolate). For the bioassay, bacterial suspensions were evaluated for toxicity against third to early fourth instar larvae of Aedes spp. The larvae of both Aedes species were orally susceptible to symbiotic bacteria. The highest larval mortality of Ae. aegypti was 99% after exposure to X. stockiae (bNN112.3_TH) at 96 h, and the highest mortality of Ae. albopictus was 98% after exposure to P. luminescens subsp. akhurstii (bNN121.4_TH) at 96 h. In contrast to the control groups (Escherichia coli and distilled water), the mortality rate of both mosquito larvae ranged between 0 and 7% at 72 h. Here, we report the first observation of X. vietnamensis in Thailand. Additionally, we report the first observation of P. luminescens subsp. akhurstii associated with H. baujardi in Thailand. X. stockiae has potential to be a biocontrol agent for mosquitoes. This investigation provides a survey of the basic diversity of EPNs and symbiotic bacteria in the National Park of Thailand, and it is a bacterial resource for further studies of bioactive compounds.

  9. Impacts of radiation management techniques on the North Atlantic Oscillation

    Science.gov (United States)

    Adakudlu, Muralidhar; Helge Otterå, Odd; Tjiputra, Jerry; Muri, Helene; Grini, Alf; Schulz, Michael

    2017-04-01

    The effectiveness of various climate engineering techniques in limiting the global warming signal to reasonable levels has been the topic of state-of-the-art research on climate change. Using an Earth system model, we show that these techniques have the potential to bring down the high CO2 concentration climate in RCP8.5 to a moderate climate similar to RCP4.5 in terms of global temperature. Nevertheless, their influence on the regional aspects of atmospheric circulation is not clear. The regional circulation patterns in the atmosphere are largely characterized by the natural variability modes, such as the North Atlantic Oscillation (NAO). In this study, we assess the impacts of three radiation managment techniques, namely, Stratospheric Aerosol Injection (SAI), Marine Sky Brightening (MSB) and Cirrus Cloud Thinning (CCT), on the structure and features of the NAO. The results indicate an east-northeastward shift as well as intensification of the NAO spatial pattern in the global warming scenarios of RCP4.5 and RCP8.5, with the signal being most intense in the latter. The climate engineering forcings when applied to the RCP8.5 case tend to reduce the strength of the NAO with little impact on its position. The CCT case appears to have the maximum effect on the NAO signal. The patterns of cloud radiative forcing, expressed as the difference between net radiative forcing at TOA under average conditions and clear sky conditions, reveal a northeastward shift of the radiative heating in the north Atlantic region. This implies a possible link between the changes in the NAO signal and the cloud radiative forcing.

  10. Life history tactics shape amphibians' demographic responses to the North Atlantic Oscillation.

    Science.gov (United States)

    Cayuela, Hugo; Joly, Pierre; Schmidt, Benedikt R; Pichenot, Julian; Bonnaire, Eric; Priol, Pauline; Peyronel, Olivier; Laville, Mathias; Besnard, Aurélien

    2017-11-01

    Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum. © 2017 John Wiley & Sons Ltd.

  11. Effects of the North Atlantic Oscillation on Spanish catches of albacore, Thunnus alalunga, and yellowfin tuna, Thunnus albacares, in the North–east Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, C.J.; MacIas, D.; Camiñas, J.A.; Fernandez, I.L.; Baez, J.C.

    2016-07-01

    Tuna are highly migratory pelagic species (HMPS) with great importance in commercial fishing. Several authors have highlighted the effect of climatic oscillations such as the NAO (North Atlantic Oscillation) on HMPS. This paper analyzes the effects of the NAO on two HMPS: albacore, Thunnus alalunga, and yellowfin tuna, Thunnus albacares. Fishing data from the Spanish fleet operating in the North Atlantic area were obtained from the International Commission for the Conservation of Atlantic Tunas (ICCAT) database. The results show a positive correlation between the NAO index and the Catch per Unit Effort (CPUE) for both albacore and yellowfin tuna, depicting a potential effect on their capturability. (Author)

  12. Temperature-precipitation relationship of the Common Era in northern Europe

    Science.gov (United States)

    Luoto, Tomi P.; Nevalainen, Liisa

    2018-05-01

    Due to the lack of knowledge on dynamics of the North Atlantic Oscillation (NAO) prior to the last millennium, synchronized records of air temperature and precipitation variability are needed to understand large-scale drivers of the hydroclimate. Here, we use completely synchronized paleolimnological proxy-based records of air temperature and effective precipitation from two Scandinavian lakes with ˜2000-year sediment profiles. We show that the relationship between air temperature and precipitation (T/P ratio) is synchronous in both study sites throughout the records suggesting warm and dry conditions at ˜300-1100 CE and cold and wet conditions at ˜1200-1900 CE. Owing to the significantly increased air temperatures, the most recent T/P ratio has again turned positive. During the first millennium of the Common Era, the T/P mimics patterns in Southern Oscillation index, whereas the second millennium shows response to the NAO index but is also concurrent with solar irradiance shifts. Since our T/P reconstruction is mostly linked with the NAO, we propose the T/P ratio as an indicator of the NAO. Our results from the coherent records provide first-time knowledge on the long-term temperature-precipitation relationship in Northern Europe that increase understanding of the comprehensive hydroclimate system in the region and the NAO dynamics also further back in time.

  13. The impact of the winter North Atlantic Oscillation on the frequency of spring dust storms over Tarim Basin in northwest China in the past half-century

    International Nuclear Information System (INIS)

    Zhao Yong; Huang Anning; Zhou Yang; Huang Ying; Zhu Xinsheng

    2013-01-01

    The relationship between the frequency of spring dust storms over Tarim Basin in northwest China and the winter North Atlantic Oscillation (NAO) is investigated by using the observed dust storm frequency (DSF) and the 10 m wind velocity at 36 stations in Tarim Basin and the National Centers for Environment Prediction/National Center for Atmospheric Research reanalysis data for the period 1961–2007. The spring DSF (winter NAO) index shows a clear decreasing (increasing) linear trend over 1961–2007. The winter NAO correlates well with the subsequent spring DSF over Tarim Basin on both interannual and interdecadal time scales and its interannual to interdecadal variation plays an important role in the spring DSF. Two possible physical mechanisms are identified. One is related to the large scale anomalous circulations in spring in the middle to high troposphere modulated by the winter NAO, providing the background of dynamical conditions for the dust storm occurrences. The other is related to the shifts in the local horizontal sea level pressure (SLP) gradients and 10 m wind speed, corresponding to changes in the large scale circulations in spring. The decrease in the local 10 m wind speed due to the reduced horizontal SLP gradients over Tarim Basin during the strong winter NAO years contributes to the decline of the DSF in the subsequent spring. (letter)

  14. Synthesis, characterization and catalytic performance of mixed nanoferrites submitted to transesterification and esterification reaction using methyl and ethyl route for biodiesel production; Sintese, caracterizacao e performance catalitica de nanoferritas mistas submetidas a reacao de transesterificacao e esterificacao via rota metilica e etilica para biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Joelda; Leal, Elvia; Mapossa, Antonio Benjamim; Silva, Adriano Sant' Ana; Costa, Ana Cristina Figueiredo de Melo, E-mail: joeldadantas@yahoo.com.br, E-mail: elvialeal@gmail.com, E-mail: mapossabenjox@gmail.com, E-mail: adriano_santana@yahoo.com.br, E-mail: ana.cristina@pq.cnpq.br [Universidade Federal de Campina Grande (LabSMaC/UAEMa/UFCG), PB (Brazil). Lab. de Sintese de Materiais Ceramicos

    2016-10-15

    The mixed nanoferrites of Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} and Ni{sub 0.2}Cu{sub 0.3}Zn{sub 0.5}Fe{sub 2}O{sub 4} were synthesized by combustion reaction using urea as fuel and a conical reactor as heating source in batches of 10 g, and then tested as heterogeneous nanocatalysts in the transesterification and esterification reaction of soya bean oil using the methyl and ethyl routes to biodiesel production. During the synthesis the time and temperature of the reactions were measured, and the evolved gases and the color of the emitted flames were observed. The samples were characterized by XRD, EDX, FTIR, SEM/EDS, BET and gas chromatography. The reaction tests were carried out with 10 g of oil for 1 h, oil:alcohol molar ratio of 1:12, 2 % (w/w) of catalyst, and conducted at 180 °C. The XRD patterns and the FTIR spectra revealed the presence of the inverse spinel phase type B(AB){sub 2}O{sub 4}. The morphology showed the formation of agglomerates with fragile morphology and high surface area. The chromatographic analysis produced excellent results in the esterification reactions for both samples in the tested conditions, with special emphasis on Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4}, whose conversions were of 91.4 % in methyl esters and of 77.8 % in ethyl esters, while the Ni{sub 0.2}Cu{sub 0.3}Zn{sub 0.5}Fe{sub 2}O{sub 4} sample showed conversion of 75.1 and 65.1 %, respectively. The conversions in the methyl and ethyl transesterification were of 14 and 2 % of the Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2}O{sub 4} sample, and of 11 and 3 % for the Ni{sub 0.2}Cu{sub 0.3}Zn{sub 0.5}Fe{sub 2}O{sub 4} sample. (author)

  15. Structural change of NaO1/2-WO3-NbO5/2-LaO3/2-PO5/2 glass induced by electrochemical substitution of sodium ions with protons.

    Science.gov (United States)

    Ishiyama, Tomohiro; Yamaguchi, Takuya; Nishii, Junji; Yamashita, Toshiharu; Kawazoe, Hiroshi; Kuwata, Naoaki; Kawamura, Junichi; Omata, Takahisa

    2015-05-28

    Structural changes of 35NaO1/2-1WO3-8NbO5/2-5LaO3/2-51PO5/2 glass (1W-glass) before and after the electrochemical substitution of sodium ions with protons by alkali-proton substitution (APS) are studied by Raman and (31)P magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectroscopies. The glass before APS consists of (PO3(-))8.6(P2O7(4-)) chains on average and the terminal Q(1) units (-O-PO3(3-)) are bound to MO6 octahedra (M denotes niobium or tungsten) through P-O-M bonds. Some non-bridging oxygens (NBOs) in the MO6 octahedra are present in addition to the bridging oxygens (BOs) in P-O-M bonds. APS induces fragmentation of the phosphate chains because the average chain length decreases to (PO3(-))3.7(P2O7(4-)) after APS, despite the total number of modifier cations of sodium and lanthanum ions and protons being unaffected by APS. This fragmentation is induced by some of the NBOs in the MO6 octahedra before APS, changing to BOs of the newly formed M-O-P bonds after APS, because of the preferential formation of P-OH bonds over M-OH ones in the present glass. We show that APS under the conditions used here is not a simple substitution of sodium ions with protons, but it is accompanied by the structural relaxation of the glass to stabilize the injected protons.

  16. Atmospheric summer teleconnections and Greenland Ice Sheet surface mass variations: insights from MERRA-2

    International Nuclear Information System (INIS)

    Lim, Young-Kwon; Schubert, Siegfried D; Molod, Andrea M; Cullather, Richard I; Zhao, Bin; Nowicki, Sophie M J; Lee, Jae N; Velicogna, Isabella

    2016-01-01

    The relationship between leading atmospheric teleconnection patterns and Greenland Ice Sheet (GrIS) temperature, precipitation, and surface mass balance (SMB) are investigated for the last 36 summers (1979–2014) based on Modern-Era Retrospective analysis for Research and Applications version 2 reanalyses. The results indicate that the negative phase of both the North Atlantic Oscillation (NAO) and Arctic Oscillation, associated with warm and dry conditions for the GrIS, lead to SMB decreases within 0–1 months. Furthermore, the positive phase of the East Atlantic (EA) pattern often lags the negative NAO, reflecting a dynamical linkage between these modes that acts to further enhance the warm and dry conditions over the GrIS, leading to a favorable environment for enhanced surface mass loss. The development of a strong negative NAO in combination with a strong positive EA in recent years leads to significantly larger GrIS warming compared to when the negative NAO occurs in combination with a negative or weak positive EA (0.69 K versus 0.13 K anomaly). During 2009 and 2011, weakened (as compared to conditions during the severe surface melt cases of 2010 and 2012) local high pressure blocking produced colder northerly flow over the GrIS inhibiting warming despite the occurrence of a strong negative NAO, reflecting an important role for the EA during those years. In particular, the EA acts with the NAO to enhance warming in 2010 and 2012, and weaken high pressure blocking in 2009 and 2011. In general, high pressure blocking primarily impacts the western areas of the GrIS via advective temperature increases, while changes in net surface radiative fluxes account for both western and eastern GrIS temperature changes. (letter)

  17. Interactions of [14C]phosphonoformic acid with renal cortical brush-border membranes. Relationship to the Na+-phosphate co-transporter

    International Nuclear Information System (INIS)

    Szczepanska-Konkel, M.; Yusufi, A.N.; Dousa, T.P.

    1987-01-01

    Since phosphonoformic acid (PFA) acts as a specific competitive inhibitor of Na+-Pi co-transport across renal brush-border membrane (BBM), we employed the [ 14 C]PFA as a probe to determine the mechanism of its interaction with rat renal BBM. The binding of [ 14 C]PFA to BBM vesicles (BBMV), with Na+ present in extravesicular medium (Na+o), was time- and temperature-dependent. The replacement of Na+o with other monovalent cations reduced the PFA binding by -80%. Cl- was the most effective accompanying monovalent anion as NaCl for maximum PFA binding. The Na+o increased the apparent affinity of BBMV for [ 14 C]PFA binding, but it did not change the maximum binding capacity. The maximum [ 14 C]PFA binding was achieved at Na+o approximately equal to 50 mM. The extent of Na+-dependent [ 14 C]PFA binding correlated with percent inhibition by an equimolar dose of PFA of the dependent BBMV uptake of 32Pi. Intravesicular Na+ (Na+i) decreased [ 14 C]PFA binding, on BBMV, and this inhibition by Na+i was dependent on the presence of Na+o. The increase in Na+i, at constant [Na+]o, decreased the Vmax, but not the Km, for [ 14 C]PFA binding on BBMV. Bound [ 14 C]PFA was displaced from BBMV by phosphonocarboxylic acids proportionally to their ability to inhibit gradient-dependent Pi transport, whereas other monophosphonates, diphosphonates, L-proline, or D-glucose did not influence the [ 14 C]PFA binding. The Na+-dependent binding of [ 14 C]PFA and of [ 3 H]phlorizin by BBMV was 10 times higher than binding of these ligands to renal basolateral membranes and to mitochondria. [ 14 C]PFA probably binds onto the same locus on the luminal surface of BBM, where Pi and Na+ form a ternary complex with the Na+-Pi co-transporter

  18. North Atlantic Oscillation and moisture transport towards the Iberian Peninsula during winter

    Science.gov (United States)

    Ordóñez, Paulina; Liberato, Margarida L. R.; Gouveia, Célia; Trigo, Ricardo M.

    2013-04-01

    The North Atlantic Oscillation (NAO) is the major source of interannual variability in winter precipitation over the Iberian Peninsula (IP). Recent works have identified the most important sources of moisture that supply the IP during different seasons of the year, including the nearby western Mediterranean and the tropical-subtropical North Atlantic corridor that extends from the Gulf of Mexico to the IP, and the IP itself (Gimeno et al., 2010). However, although rainfall is directly related to the moisture supply, the relationship between the water vapor transported towards IP and the NAO phase remains unclear. In this work the moisture transport towards IP was analyzed using a Lagrangian diagnosis method, which relies on the Lagrangian particle dispersion model FLEXPART. This methodology computes budgets of evaporation minus precipitation (E-P) by evaluating changes in the specific humidity along back-trajectories. Here we have computed (for each day) the evolution of moisture of the particles bound for Iberia up to 10 days prior to their arrival. The analysis was constrained to the winter (DJF) season, responsible for the largest fraction of precipitation, for the 20 years of ECMWF Reanalyses ERA40 dataset from 1980 to 2000. The contribution of the NAO phase on the water budgets is examined using composites of the obtained (E - P) fields for the 5 most extreme positive and negative NAO years of the study period. Results confirm that the IP is dominated by positive (negative) E-P anomalies during positive (negative) NAO phase. Additionally an anomalous water vapor sink (source) region located approximately over the Gulf Stream is found during positive (negative) NAO phase. Gimeno L., Nieto R., Trigo R.M. , Vicente-Serrano S.M, Lopes-Moreno J.I., (2010) "Where does the Iberian Peninsula moisture come from? An answer based on a Lagrangian approach". J. Hydrometeorology, 11, 421-436 DOI: 10.1175/2009JHM1182.1.

  19. Land surface anomalies preceding the 2010 Russian heat wave and a link to the North Atlantic oscillation

    International Nuclear Information System (INIS)

    Wright, Christopher K; Henebry, Geoffrey M; De Beurs, Kirsten M

    2014-01-01

    The Eurasian wheat belt (EWB) spans a region across Eastern Ukraine, Southern Russia, and Northern Kazakhstan; accounting for nearly 15% of global wheat production. We assessed land surface conditions across the EWB during the early growing season (April–May–June; AMJ) leading up to the 2010 Russian heat wave, and over a longer-term period from 2000 to 2010. A substantial reduction in early season values of the normalized difference vegetation index occurred prior to the Russian heat wave, continuing a decadal decline in early season primary production in the region. In 2010, an anomalously cold winter followed by an abrupt shift to a warmer-than-normal early growing season was consistent with a persistently negative phase of the North Atlantic oscillation (NAO). Regression analyses showed that early season vegetation productivity in the EWB is a function of both the winter (December–January–February; DJF) and AMJ phases of the NAO. Land surface anomalies preceding the heat wave were thus consistent with highly negative values of both the DJF NAO and AMJ NAO in 2010. (letter)

  20. Are the North Atlantic oscillation and the southern oscillation related in any time-scale?

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, R.; Ribera, P.; Hernandez, E. [Universidad Complutense de Madrid (Spain). Facultad de Ciencias Fisicas; Gimenoo, L. [Fac. Ciencias, Univ. Vigo, Ourense (Spain)

    2000-02-01

    The north Atlantic oscillation (NAO) and the southern oscillation (SO) are compared from the standpoint of a possible common temporal scale of oscillation. To do this a cross-spectrum of the temporal series of NAO and SO indices was determined, finding a significant common oscillation of 6-8 years. To assure this finding, both series were decomposed in their main oscillations using singular spectrum analysis (SSA). Resulting reconstructed series of 6-8 years' oscillation were then cross-correlated without and with pre-whitened, the latter being significant. The main conclusion is a possible relationship between a common oscillation of 6-8 years that represents about 20% of the SO variance and about 25% of the NAO variance. (orig.)

  1. Ultra-low power thin film transistors with gate oxide formed by nitric acid oxidation method

    International Nuclear Information System (INIS)

    Kobayashi, H.; Kim, W. B.; Matsumoto, T.

    2011-01-01

    We have developed a low temperature fabrication method of SiO 2 /Si structure by use of nitric acid, i.e., nitric acid oxidation of Si (NAOS) method, and applied it to thin film transistors (TFT). A silicon dioxide (SiO 2 ) layer formed by the NAOS method at room temperature possesses 1.8 nm thickness, and its leakage current density is as low as that of thermally grown SiO 2 layer with the same thickness formed at ∼900 deg C. The fabricated TFTs possess an ultra-thin NAOS SiO 2 /CVD SiO 2 stack gate dielectric structure. The ultrathin NAOS SiO 2 layer effectively blocks a gate leakage current, and thus, the thickness of the gate oxide layer can be decreased from 80 to 20 nm. The thin gate oxide layer enables to decrease the operation voltage to 2 V (cf. the conventional operation voltage of TFTs with 80 nm gate oxide: 12 V) because of the low threshold voltages, i.e., -0.5 V for P-ch TFTs and 0.5 V for N-ch TFTs, and thus the consumed power decreases to 1/36 of that of the conventional TFTs. The drain current increases rapidly with the gate voltage, and the sub-threshold voltage is ∼80 mV/dec. The low sub-threshold swing is attributable to the thin gate oxide thickness and low interface state density of the NAOS SiO 2 layer. (authors)

  2. Variability of the North Atlantic Oscillation over the past 5,200 years

    DEFF Research Database (Denmark)

    Olsen, Jesper; Anderson, N. John; Knudsen, Mads Faurschou

    2012-01-01

    the index is positive, Europe and the eastern US are mild and wet, whereas Greenland and northern Canada are cold and dry. A negative index is associated with the reverse pattern. Reconstructions of the NAO have so far been limited to the past 900 years(3). Here we analyse a 5,200-year-long, high......-resolution lake sediment record from southwestern Greenland to reconstruct lake hypolimnic anoxia, and link the results to an existing reconstruction of the NAO index from tree rings and speleothems(3). Using the relationship between the two records, we find that around 4,500 and 650 years ago-around the end....... However, the onset of the Medieval Climate Anomaly was not associated with any notable changes in the NAO....

  3. As virtudes da atenção: "The corn harvest", de William Carlos Williams As virtudes da atenção: "The corn harvest", de William Carlos Williams

    Directory of Open Access Journals (Sweden)

    Thomas Jackson

    2008-04-01

    Full Text Available E claro que a critica literiria nao 6 uma ciéncia e que, exceto para o quimico industrial, uma obra literaria nao pode ser objeto de um estudo cientifico autantico. Um texto liter&rio assume a sua estatura pr6pria a partir da maneira como a visto por uma audiancia muito embora esta afirmagao deva ser explicitada. ConcepcOes semi-cientificas da literatura e da critics. (A concepcao de Northrop Frye 6 provavelmente a mais simplificada, o estruturalismo a mais confuse aparentemente levam a um erro de categorizagao: o pressuposto de que a literatura 6 uma categoria da mesma forma que, por exemplo, os batriquios. Estes existem exteriormente, independentemente da percepgao humane, e isto nao ocorre de forma analoga com a literature.

  4. Regional climatic and North Atlantic Oscillation signatures in West Virginia red cedar over the past millennium

    Science.gov (United States)

    D'Arrigo, Rosanne; Anchukaitis, Kevin J.; Buckley, Brendan; Cook, Ed; Wilson, Rob

    2012-03-01

    We describe a millennial length (~ 1500-yr) tree-ring chronology developed from West Virginia (WVA), USA red cedar (Juniperus virginiana) ring widths that is significantly correlated with local to regional temperature and precipitation for the region. Using ensemble methods of tree-ring standardization, above average ring widths are indicated for the period between ~ 1000 and 1300 CE, the approximate time of the Medieval Climate Anomaly (MCA), the most recent major warm episode prior to the modern era. The chronology then transitions to more negative overall growth persisting through much of the subsequent period known as the Little Ice Age (LIA). While WVA cedar growth levels during the MCA are broadly similar to the 20th century mean, the most positive values during the MCA are associated with RCS-standardized chronologies, which pseudoproxy tests reveal are likely biased artificially positive, warranting further investigation. This cedar record is significantly correlated with the NAO, due to the tendency for warmer, wetter conditions to occur in the eastern-central USA during the NAO's positive phase. These types of conditions are inferred for this cedar chronology during the MCA period, during which NAO reconstructions suggest a persistently-positive NAO state.

  5. Climate and changing winter distribution of alcids in the Northwest Atlantic

    Directory of Open Access Journals (Sweden)

    Richard R. Veit

    2015-04-01

    Full Text Available Population level impacts upon seabirds from changing climate are increasingly evident, and include effects on phenology, migration, dispersal, annual survivorship and reproduction. Most population data on seabirds derive from nesting colonies; documented climate impacts on winter ecology are scarce. We studied interannual variability in winter abundance of six species of alcids (Charadriiformes, Alcidae from a 58-year time series of data collected in Massachusetts 1954-2011. We used counts of birds taken during fall and winter from coastal vantage points. Counts were made by amateur birders, but coverage was consistent in timing and location. We found significant association between winter abundance of all six species of alcids and climate, indexed by North Atlantic Oscillation (NAO, at two temporal scales: 1. Significant linear trends at the 58-year scale of the time series; and 2. Shorter term fluctuations corresponding to the 5-8 year periodicity of NAO. Thus, variation in winter abundance of all six species of alcids was significantly related to the combined short-term and longer-term components of variation in NAO. Two low-Arctic species (Atlantic Puffin and Black Guillemot peaked during NAO positive years, while two high Arctic species (Dovekie and Thick-billed Murre peaked during NAO negative years. For Common Murres and Razorbills, southward shifts in winter distribution have been accompanied by southward expansion of breeding range, and increase within the core of the range. The proximate mechanism governing these changes is unclear, but, as for most other species of seabirds whose distributions have changed with climate, seems likely to be through their prey.

  6. High-Capacity Sodium Peroxide Based NaO2 Batteries with Low Charge Overpotential via a Nanostructured Catalytic Cathode

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Lu; Zhang, Dongzhou [Partnership; Lei, Yu [Department; Yuan, Yifei; Wu, Tianpin; Lu, Jun; Amine, Khalil

    2018-01-05

    The superoxide based Na-O-2 battery has circumvented the issue of large charge overpotential in Li-O-2 batteries; however, the one-electron process leads to limited capacity. Herein, a sodium peroxide based low-overpotential (similar to 0.5 V) Na-O-2 battery with a capacity as high as 7.5 mAh/cm(2) is developed with Pd nanoparticles as catalysts on the cathode.

  7. Virtual Surgery for the Nasal Airway: A Preliminary Report on Decision Support and Technology Acceptance.

    Science.gov (United States)

    Vanhille, Derek L; Garcia, Guilherme J M; Asan, Onur; Borojeni, Azadeh A T; Frank-Ito, Dennis O; Kimbell, Julia S; Pawar, Sachin S; Rhee, John S

    2018-01-01

    Nasal airway obstruction (NAO) is a common problem that affects patient quality of life. Surgical success for NAO correction is variable. Virtual surgery planning via computational fluid dynamics (CFD) has the potential to improve the success rates of NAO surgery. To elicit surgeon feedback of a virtual surgery planning tool for NAO and to determine if this tool affects surgeon decision making. For this cross-sectional study, 60-minute face-to-face interviews with board-certified otolaryngologists were conducted at a single academic otolaryngology department from September 16, 2016, through October 7, 2016. Virtual surgery methods were introduced, and surgeons were able to interact with the virtual surgery planning tool interface. Surgeons were provided with a patient case of NAO, and open feedback of the platform was obtained, with emphasis on surgical decision making. Likert scale responses and qualitative feedback were collected for the virtual surgery planning tool and its influence on surgeon decision making. Our 9 study participants were all male, board-certified otolaryngologists with a mean (range) 15 (4-28) number of years in practice and a mean (range) number of nasal surgeries per month at 2.2 (0.0-6.0). When examined on a scale of 1 (not at all) to 5 (completely), surgeon mean (SD) score was 3.4 (0.5) for how realistic the virtual models were compared with actual surgery. On the same scale, when asked how much the virtual surgery planning tool changed surgeon decision making, mean (SD) score was 2.6 (1.6). On a scale of 1 (strongly disagree) to 7 (strongly agree), surgeon scores for perceived usefulness of the technology and attitude toward using it were 5.1 (1.1) and 5.7 (0.9), respectively. Our study shows positive surgeon experience with a virtual surgery planning tool for NAO based on CFD simulations. Surgeons felt that future applications and areas of study of the virtual surgery planning tool include its potential role for patient counseling

  8. The Caspian Sea Catchment influenced by Atlantic Teleconnections in CESM1.2.2 and Observations

    Science.gov (United States)

    Nandini, S. D.; Prange, M.; Schulz, M.

    2017-12-01

    The Caspian Sea (CS) is the world's largest inland sea and located within a closed (endorheic) drainage basin [ 37°-47N, 47°-54°E]. It has undergone dynamic variations (>3 m) during the past century with huge impacts on the economy, ecosystem and livelihood of coastal people. The origin of these variations as well as future changes are disputable. Here, we examine the impact of the major seasonal North Atlantic teleconnection patterns, the North Atlantic Oscillation (NAO) and the East Atlantic pattern (EA) on Caspian hydroclimate variability from 1850-2100 CE. Five Numerical experiments at different atmospheric grid resolutions (2° and 1°) and atmospheric model versions (CAM4 and CAM5) are carried out with the coupled Community Earth System Model (CESM1.2.2). Results reveal the 1° CESM1.2.2 CAM5 captures DJF NAO (46.5%) and EA (13.4%), agreeing well with observational data (1850-2000). The DJF NAO has a strong influence on the DJF temperature, rainfall and evaporation minus precipitation (E-P) over the Caspian sub-basins (Volga, Ural, Terek and Kura). Furthermore, 1° model climate projections (2020-2100 CE) are performed with different Representative Concentration Pathways (RCP4.5 and RCP8.5) to examine likely changes in the NAO and EA and their influence on the Caspian catchment. The NAO under the RCP4.5 and RCP8.5 scenarios remains the leading mode with the highest variance and influences E-P with increased precipitation over the Volga basin and increased evaporation over the Caspian Sea. The above canceling effects act on the hydroclimate variability in the Caspian sub-basins. Moreover, it is indicated that no substantial change is predicted in the CSL by the year 2100. Keywords: North Atlantic Oscillation (NAO), CESM1.2.2 resolutions, Evaporation minus Precipitation (E-P), RCP4.5, RCP8.5

  9. Anion-coupled Na efflux mediated by the human red blood cell Na/K pump

    International Nuclear Information System (INIS)

    Dissing, S.; Hoffman, J.F.

    1990-01-01

    The red cell Na/K pump is known to continue to extrude Na when both Na and K are removed from the external medium. Because this ouabain-sensitive flux occurs in the absence of an exchangeable cation, it is referred to as uncoupled Na efflux. This flux is also known to be inhibited by 5 mM Nao but to a lesser extent than that inhibitable by ouabain. Uncoupled Na efflux via the Na/K pump therefore can be divided into a Nao-sensitive and Nao-insensitive component. We used DIDS-treated, SO4-equilibrated human red blood cells suspended in HEPES-buffered (pHo 7.4) MgSO4 or (Tris)2SO4, in which we measured 22Na efflux, 35SO4 efflux, and changes in the membrane potential with the fluorescent dye, diS-C3 (5). A principal finding is that uncoupled Na efflux occurs electroneurally, in contrast to the pump's normal electrogenic operation when exchanging Nai for Ko. This electroneutral uncoupled efflux of Na was found to be balanced by an efflux of cellular anions. (We were unable to detect any ouabain-sensitive uptake of protons, measured in an unbuffered medium at pH 7.4 with a Radiometer pH-STAT.) The Nao-sensitive efflux of Nai was found to be 1.95 +/- 0.10 times the Nao-sensitive efflux of (SO4)i, indicating that the stoichiometry of this cotransport is two Na+ per SO4=, accounting for 60-80% of the electroneutral Na efflux. The remainder portion, that is, the ouabain-sensitive Nao-insensitive component, has been identified as PO4-coupled Na transport and is the subject of a separate paper. That uncoupled Na efflux occurs as a cotransport with anions is supported by the result, obtained with resealed ghosts, that when internal and external SO4 was substituted by the impermeant anion, tartrate i,o, the efflux of Na was inhibited 60-80%. This inhibition could be relieved by the inclusion, before DIDS treatment, of 5 mM Cli,o

  10. Oxygen Isotope Speleothem record of Decadal and Multidecadal Atlantic Oscillations over the last millennium in Southwestern Morocco

    Science.gov (United States)

    Ait Brahim, Yassine; Sha, LiJuan; Sifeddine, Abdelfettah; Cheng, Hai; Bouchaou, Lhoussaine; Da Cruz Junior, Francisco William; Khodri, Myriam; Peerbocus, Nawaaz; Mariller, Alexandre; Apaestegui, James; Guyot, Jean-Loup; Auler, Augusto; Hassane Beraaouz, El

    2016-04-01

    In this work, we present a stable oxygen isotope (δ18O) speleothem record from Ifoulki cave located South-West of Morocco (N 30°42'29'', W 09°19'39'' and 1267 meters above sea level). The age model, based on eighteen U-Th dates, reveals that the record covers the AD 790-1953 period with a data resolution of ~1.7 years. Stable oxygen isotope variations show substantial decadal to multi-decadal swings between dry and humid periods. The Medieval Climate Anomaly (MCA) is characterized by the longest period with δ18O values above the average, suggestive of pronounced drying possibly as a response to positive North Atlantic Oscillation (NAO) phases and increased volcanic activity during this period. However, at least two short wet phases are recognized during the MCA in Morocco, with peaks centered on the years AD 1040 and AD 1190 and seem to overlap with negative NAO phases as recorded in a recently published NAO reconstruction for the last millennium. During the next centuries, the NAO again depicts predominantly negative values and the δ18O drops below the average during the Little Ice Age (LIA). Furthermore, a striking resemblance is observed between our record and another recently published stalagmite record from the Piste cave in Northeastern Morocco, which is quite remarkable given the different type of tracers (δ18O vs. Mg and Sr) obtained from different environments (Western High Atlas vs. Northeastern Middle Atlas and ~634 km away). Comparison with regional paleorecords from other studies also reveals the replication of many characteristic climate features from the last millennium, first detected in Northern Morocco and the Iberian Peninsula. In particular, the evidence of generally dry conditions during the MCA and wetter conditions in the LIA, which is confirmed by all the paleorecords. These similarities indicate coherent climate variability in Northwest Africa and the Iberian Peninsula and suggest a strong regional control of the NAO during the last

  11. Intraseasonal interaction between the Madden-Julian Oscillation and the North Atlantic Oscillation.

    Science.gov (United States)

    Cassou, Christophe

    2008-09-25

    Bridging the traditional gap between the spatio-temporal scales of weather and climate is a significant challenge facing the atmospheric community. In particular, progress in both medium-range and seasonal-to-interannual climate prediction relies on our understanding of recurrent weather patterns and the identification of specific causes responsible for their favoured occurrence, persistence or transition. Within this framework, I here present evidence that the main climate intra-seasonal oscillation in the tropics-the Madden-Julian Oscillation (MJO)-controls part of the distribution and sequences of the four daily weather regimes defined over the North Atlantic-European region in winter. North Atlantic Oscillation (NAO) regimes are the most affected, allowing for medium-range predictability of their phase far exceeding the limit of around one week that is usually quoted. The tropical-extratropical lagged relationship is asymmetrical. Positive NAO events mostly respond to a mid-latitude low-frequency wave train initiated by the MJO in the western-central tropical Pacific and propagating eastwards. Precursors for negative NAO events are found in the eastern tropical Pacific-western Atlantic, leading to changes along the North Atlantic storm track. Wave-breaking diagnostics tend to support the MJO preconditioning and the role of transient eddies in setting the phase of the NAO. I present a simple statistical model to quantitatively assess the potential predictability of the daily NAO index or the sign of the NAO regimes when they occur. Forecasts are successful in approximately 70 per cent of the cases based on the knowledge of the previous approximately 12-day MJO phase used as a predictor. This promising skill could be of importance considering the tight link between weather regimes and both mean conditions and the chances of extreme events occurring over Europe. These findings are useful for further stressing the need to better simulate and forecast the tropical

  12. RuPd, RuCo, PdCo and RuPdCo materials as candidates for cathode catalyzers in PEM fuel cells; Materiales RuPd, RuCo, PdCo y RuPdCo como candidatos a catalizadores catodicos en celdas de combustible tipo PEM

    Energy Technology Data Exchange (ETDEWEB)

    Leyva Noyola, Fatima; Solorza Feria, Omar [Centro de Investigacion y Estudios Superiores del IPN, Mexico, D.F. (Mexico)]. E-mail: fleyva@cinvestav.mx

    2009-09-15

    This work reports on the catalytic activity of RuPd, RuCo, PdCo and RuPdCo material for oxygen reduction reaction (ORR). These materials were synthesized using chemical reduction with NaBH{sub 4} as a reducing agent in THF, in ambient temperature and pressure conditions. The evaluation of the catalytic activity was done using cyclic voltamperometry (CV) and rotary disc electrode (RDE) in H{sub 2}SO{sub 4} 0.5 M. The kinetic results showed that the electrochemical reaction involves 4 electrons and the transfer of the first electron is the determinant stage. The values of {alpha}, i0 and the Tafel slope were very similar for the four materials studied, around 0.4, 5x10{sup -6} mA cm{sup -2} and 60 mV dec-1, respectively. Although these values are less than those reported for nanostructured platinum, they are better than those reported for other materials such as pure Pd, which enables them to be considered as cathode catalysts for a proton exchange membrane fuel cell. [Spanish] En este trabajo se reporta la actividad catalitica de los materiales RuPd, RuCo, PdCo y RuPdCo para la reaccion de reduccion de oxigeno (RRO). Estos materiales fueron sintetizados por el metodo de reduccion quimica, usando NaBH{sub 4} como agente reductor en THF, en condiciones de temperatura y presion ambiental. La evaluacion de la actividad catalitica fue realizada usando Voltamperometria Ciclica (VC) y Electrodo Disco Rotatorio (EDR) en H{sub 2}SO{sub 4} 0.5 M. Los resultados cineticos mostraron que la reaccion electroquimica procede por la via de 4 electrones y la etapa determinante es la transferencia del primer electron. Los valores de {alpha}, i0 y pendiente de Tafel fueron muy similares para los 4 materiales estudiados, siendo estos de alrededor de 0.4, 5x10{sup -6} mA cm{sup -2} y 60 mV dec{sup -1}, respectivamente. Sin embargo, aun cuando estos valores son menores que los reportados para platino nanoestructurado, son mejores que los reportados para otros materiales como el Pd puro

  13. Study of pressing effects and variation in Pt charge in the anode on the performance of membrane electrode assemblies; Estudio de los efectos de prensado y variacion de la carga de Pt en el anodo en el rendimiento de ensambles membrana-electrodo

    Energy Technology Data Exchange (ETDEWEB)

    Albarran S, Irma Lorena; Flores Hernandez, J. Roberto; Cano Castillo, Ulises [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico). E-mail: ilas@iie.org.mx; Loyola, Felix (UNAM, Facultad de Quimica, Mexico D.F. (Mexico)

    2009-09-15

    Fabricating membrane electrode assemblies (MEA) involves different variables that determine their performance, such as: amount of the catalyst, concentration of the different solvents used in the fabrication of the catalyst dye, use of a thermomechanical process to increase the degree of adhesion between the catalyst layers and the membrane, etc. This work studied the effect of the Pt charge in the anode on performance, as well as the effect of the thermomechanical process on the fabrication of MEAs. It is evident that the optimal Pt charge should be that which provides good performance during an acceptable useful lifetime at a competitive cost. This work presents the results obtained by varying the Pt charge in the anode between 1.0 and 0.4 mgPt/cm{sup ²} while maintaining a constant charge of 1 mgPt/cm{sup ²} in the cathode. It also shows the comparison between the polarization curves and the active areas obtained in the MEAs with and without pressing during their fabrication. [Spanish] En la fabricacion de los Ensambles Membrana-Electrodo (MEA's) intervienen diferentes variables que determinan su desempeno, como lo son: cantidad de catalizador, concentracion de los diferentes solventes que se emplean en la fabricacion de la tinta catalitica, el uso de un proceso termomecanico para incrementar el grado de adherencia entre las capas cataliticas y la membrana, etc. De las variables anteriormente mencionadas, en este trabajo se estudio el efecto de la carga anodica de Pt en el desempeno, asi como del proceso termomecanico en la fabricacion de MEA's. Es evidente que la carga optima de Pt debe ser aquella que proporcione un buen rendimiento por un periodo de vida util aceptable a un costo competitivo. En este trabajo se presentan los resultados obtenidos al variar la carga de Pt en el anodo entre 1.0 a 0.4 mgPt/cm{sup ²} manteniendo una carga constante de 1 mgPt/cm{sup ²} en el catodo. Tambien se muestra la comparacion de las curvas de polarizacion y las

  14. Altered Na+ transport after an intracellular alpha-subunit deletion reveals strict external sequential release of Na+ from the Na/K pump.

    Science.gov (United States)

    Yaragatupalli, Siddhartha; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

    2009-09-08

    The Na/K pump actively exports 3 Na(+) in exchange for 2 K(+) across the plasmalemma of animal cells. As in other P-type ATPases, pump function is more effective when the relative affinity for transported ions is altered as the ion binding sites alternate between opposite sides of the membrane. Deletion of the five C-terminal residues from the alpha-subunit diminishes internal Na(+) (Na(i)(+)) affinity approximately 25-fold [Morth et al. (2007) Nature 450:1043-1049]. Because external Na(+) (Na(o)(+)) binding is voltage-dependent, we studied the reactions involving this process by using two-electrode and inside-out patch voltage clamp in normal and truncated (DeltaKESYY) Xenopus-alpha1 pumps expressed in oocytes. We observed that DeltaKESYY (i) decreased both Na(o)(+) and Na(i)(+) apparent affinities in the absence of K(o)(+), and (ii) did not affect apparent Na(o)(+) affinity at high K(o)(+). These results support a model of strict sequential external release of Na(+) ions, where the Na(+)-exclusive site releases Na(+) before the sites shared with K(+) and the DeltaKESYY deletion only reduces Na(o)(+) affinity at the shared sites. Moreover, at nonsaturating K(o)(+), DeltaKESYY induced an inward flow of Na(+) through Na/K pumps at negative potentials. Guanidinium(+) can also permeate truncated pumps, whereas N-methyl-D-glucamine cannot. Because guanidinium(o)(+) can also traverse normal Na/K pumps in the absence of both Na(o)(+) and K(o)(+) and can also inhibit Na/K pump currents in a Na(+)-like voltage-dependent manner, we conclude that the normal pathway transited by the first externally released Na(+) is large enough to accommodate guanidinium(+).

  15. The impact of Arctic and North Atlantic oscillation on temperature and precipitation anomalies in Serbia

    Directory of Open Access Journals (Sweden)

    Pavlović-Berdon Nada

    2012-01-01

    Full Text Available The impact of the Arctic Oscillations (AO and the North Atlantic Oscillations (NAO is considered as the most prominent of atmospheric oscillations in the area of the northern hemisphere from the United States to Siberia and from the Arctic to the subtropical Atlantic. The aim of this study was to determine how these fluctuations affect the temperature and precipitation in Serbia. This paper explores the impact for the period of 50 years (1958-2007 by months and in 20 synoptic stations. The influence of the AO on temperature anomalies in Serbia can be seen by the correlation coefficient, the largest in the month of January, while its impact on precipitation is the largest in the month of February. After the test of linear correlation between the NAO index and temperature anomalies for the base period 1971-2000 for 20 synoptic stations in Serbia, it has been found that the highest correlation is in the month of January. The correlation between the NAO and the precipitation anomalies for the stations mentioned above is the highest in the month of February. Spatial patterns of the AO and the NAO influence on temperature in January and on precipitation in February were obtained by applying principal component analysis.

  16. Climate Variability Reveals Complex Events for Tularemia Dynamics in Man and Mammals

    Directory of Open Access Journals (Sweden)

    Thomas R. Palo

    2005-06-01

    Full Text Available Tularemia is caused by the bacterium Francisella tularensis, but the natural reservoir is unknown and environmental conditions for outbreaks in mammals and man are poorly understood. The present study analyzed the synchrony between the North Atlantic Oscillation (NAO index, the number of human cases of tularemia reported in Sweden, and the density of hares. Climate variation at a lag of 2 yr explained as a single factor ~ 27% of the variation in the number of tularemia cases over time. A low NAO index, indicating cold winters, and low water flow in rivers during the coming summer were associated with high numbers of human cases of tularemia 2 yr later. The number of mountain hares was not related to NAO or to the number of cases of tularemia. The change in mountain hare numbers was negatively associated with the number of human cases, showing the sensitivity of this species to the disease. Low turnover in water environments may at some point in time trigger a chain of events leading to increased replication of F. tularensis via unknown reservoirs and/or vectors that affect humans and mammals. A possible increase in the NAO index with a future warmer climate would not be expected to facilitate a higher frequency of tularemia outbreaks in Sweden.

  17. The Anomalous Winter of 1783-1784: Was the Laki Eruption or an Analog of the 2009-2010 Winter to Blame?

    Science.gov (United States)

    D'Arrigo, Rosanne; Seager, Richard; Smerdon, Jason E.; LeGrande, Allegra N.; Cook, Edward R.

    2011-01-01

    The multi ]stage eruption of the Icelandic volcano Laki beginning in June, 1783 is speculated to have caused unusual dry fog and heat in western Europe and cold in North America during the 1783 summer, and record cold and snow the subsequent winter across the circum-North Atlantic. Despite the many indisputable impacts of the Laki eruption, however, its effect on climate, particularly during the 1783.1784 winter, may be the most poorly constrained. Here we test an alternative explanation for the unusual conditions during this time: that they were caused primarily by a combined negative phase of the North Atlantic Oscillation (NAO) and an El Nino ]Southern Oscillation (ENSO) warm event. A similar combination of NAO ]ENSO phases was identified as the cause of record cold and snowy conditions during the 2009.2010 winter in Europe and eastern North America. 600-year tree-ring reconstructions of NAO and ENSO indices reveal values in the 1783.1784 winter second only to their combined severity in 2009.2010. Data sources and model simulations support our hypothesis that a combined, negative NAO ]ENSO warm phase was the dominant cause of the anomalous winter of 1783.1784, and that these events likely resulted from natural variability unconnected to Laki.

  18. Slow walking model for children with multiple disabilities via an application of humanoid robot

    Science.gov (United States)

    Wang, ZeFeng; Peyrodie, Laurent; Cao, Hua; Agnani, Olivier; Watelain, Eric; Wang, HaoPing

    2016-02-01

    Walk training research with children having multiple disabilities is presented. Orthosis aid in walking for children with multiple disabilities such as Cerebral Palsy continues to be a clinical and technological challenge. In order to reduce pain and improve treatment strategies, an intermediate structure - humanoid robot NAO - is proposed as an assay platform to study walking training models, to be transferred to future special exoskeletons for children. A suitable and stable walking model is proposed for walk training. It would be simulated and tested on NAO. This comparative study of zero moment point (ZMP) supports polygons and energy consumption validates the model as more stable than the conventional NAO. Accordingly direction variation of the center of mass and the slopes of linear regression knee/ankle angles, the Slow Walk model faithfully emulates the gait pattern of children.

  19. Na3Tb(PO4)2: Synthesis, crystal structure and greenish emitting properties

    Science.gov (United States)

    Zhao, Dan; Ma, Zhao; Liu, Bao-Zhong; Zhang, Rui-Juan; Wu, Zhi-Qiang; Wang, Jian; Duan, Pei-Gao

    2018-03-01

    A anhydrous orthoborate Na3Tb(PO4)2 has been prepared and its crystal structure was determined by X-Ray diffraction of a non-merohedral twinned single crystal. The results show that the compound crystallizes in monoclinic space group C2/c and the structure features a 3D framework containing PO4, NaO6, NaO7, NaO8 and TbO8 polyhedra. Under near-UV excitation (370 nm), Na3Tb(PO4)2 shows intense characteristic emission bands of Tb3+ (490 nm, 543 nm, 585 nm and 620 nm) with the CIE coordinate of (0.3062, 0.5901), corresponding to greenish color. The excitation spectrum covers a wide range from 340 nm to 390 nm, which indicates that phosphor Na3Tb(PO4)2 can be efficiently activated by near-UV LED ship.

  20. Analysis of a high-resolution regional climate simulation for Alpine temperature. Validation and influence of the NAO

    Energy Technology Data Exchange (ETDEWEB)

    Proemmel, K. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Kuestenforschung

    2008-11-06

    elevations reaches -3.5 K, whereas by applying a monthly varying lapse rate based on the station data it reaches only about -1 K. The comparison of the REMO simulation and ERA40 reanalysis shows that the added value of the former varies between seasons and regions. In some regions it also depends on the selection of stations used for the validation. Robust features include a better performance of REMO in the inner Alpine subregions, where the orography is most complex. The lack of consistent value added by REMO in this hindcast setup may be partly explicable by the fact that meteorological measurements are assimilated in the ERA40 reanalysis but not in the REMO simulation. As the higher resolution leads to an added value in the simulation of temperature, at least in the most complex areas, the question is addressed whether it also leads to more detailed structures in the temperature response to circulation variability. In this study the temperature response to the North Atlantic Oscillation (NAO) with its strong influence on European winter climate is analysed over the GAR by using a very dense homogenised station dataset (HISTALP and stations from Austrian and Swiss weather services), the high-resolution simulation (for information in areas, where no station data are available) and the reanalysis. In earlier studies only a few individual stations or gridded data not higher resolved than 1 were used. The temperature signals based on the station data and based on the model data have very similar patterns and are in agreement with the European-wide pattern. The highly resolved model data show an additional clear small-scale pattern with a strong signal south of the main Alpine ridge potentially caused by the foehn effect. This small-scale structure is not visible in the reanalysis due to the coarser resolution and was also not found in previous studies based on both station and model data for the same reason. (orig.)

  1. Atmospheric mechanisms governing the spatial and temporal variability of phenological phases in central Europe

    Science.gov (United States)

    Scheifinger, Helfried; Menzel, Annette; Koch, Elisabeth; Peter, Christian; Ahas, Rein

    2002-11-01

    A data set of 17 phenological phases from Germany, Austria, Switzerland and Slovenia spanning the time period from 1951 to 1998 has been made available for analysis together with a gridded temperature data set (1° × 1° grid) and the North Atlantic Oscillation (NAO) index time series. The disturbances of the westerlies constitute the main atmospheric source for the temporal variability of phenological events in Europe. The trend, the standard deviation and the discontinuity of the phenological time series at the end of the 1980s can, to a great extent, be explained by the NAO. A number of factors modulate the influence of the NAO in time and space. The seasonal northward shift of the westerlies overlaps with the sequence of phenological spring phases, thereby gradually reducing its influence on the temporal variability of phenological events with progression of spring (temporal loss of influence). This temporal process is reflected by a pronounced decrease in trend and standard deviation values and common variability with the NAO with increasing year-day. The reduced influence of the NAO with increasing distance from the Atlantic coast is not only apparent in studies based on the data set of the International Phenological Gardens, but also in the data set of this study with a smaller spatial extent (large-scale loss of influence). The common variance between phenological and NAO time series displays a discontinuous drop from the European Atlantic coast towards the Alps. On a local and regional scale, mountainous terrain reduces the influence of the large-scale atmospheric flow from the Atlantic via a proposed decoupling mechanism. Valleys in mountainous terrain have the inclination to harbour temperature inversions over extended periods of time during the cold season, which isolate the valley climate from the large-scale atmospheric flow at higher altitudes. Most phenological stations reside at valley bottoms and are thus largely decoupled in their temporal

  2. Finding of No Significant Impact, Skiffes Creek Federal Navigation Channel Maintenance Dredging, Joint Base Langley-Eustis, Fort Eustis, Virginia

    Science.gov (United States)

    2014-06-06

    National Marine Fisheries Service Habitat Conservation District 904 South Morris Street Oxford, MD 21654 Dear Mr. Goodger: The U.S. Army...Nadal, Teresita I NAO From: Nadal, Teresita I NAO Sent: Tuesday , February 04, 2014 2:10 PM To: ’David.L.O’Brien@noaa.gov’ Subject: Skiffes Creek EFH...Noaa.gov). Sincerely, DanielS. Morris Acting Regional Administrator File Code: H:\\S7ST1Section 7\\Non-Fisheries\\ACOE\\Infonnal\\20 I2\\Norfolk District

  3. Evaluation of the Atlantic Multidecadal Oscillation Impact on Large-Scale Atmospheric Circulation in the Atlantic Region in Summer

    Science.gov (United States)

    Semenov, V. A.; Cherenkova, E. A.

    2018-02-01

    The influence of the Atlantic Multidecadal Oscillation (AMO) on large-scale atmospheric circulation in the Atlantic region in summer for the period of 1950-2015 is investigated. It is shown that the intensification of the summer North Atlantic Oscillation (NAO) with significant changes in sea level pressure anomalies in the main centers of action (over Greenland and the British Isles) occurred while the North Atlantic was cooler. Sea surface temperature anomalies, which are linked to the AMO in the summer season, affect both the NAO index and fluctuations of the Eastern Atlantic/Western Russia (EAWR) centers of action. The positive (negative) phase of the AMO is characterized by a combination of negative (positive) values of the NAO and EAWR indices. The dominance of the opposite phases of the teleconnection indices in summer during the warm North Atlantic and in its colder period resulted in differences in the regional climate in Europe.

  4. Modeling of atmospheric circulation at mid- and high latitudes of the northern hemisphere - evaluation studies using ARPEGE

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yongjia

    2007-03-15

    In the present thesis the author evaluate experiments with the atmospheric part of BCM (Bergen climate model), named ARPEGE, performed for present day climate during the last 50 years. The objectives have been to evaluate the ability of ARPEGE to simulate the general circulation at mid- and high northern latitudes in winter. Particular emphasis is put on the dependence of systematic errors on the horizontal resolution in the model, the climatology and variability of storm tracks, the poleward energy transport and the North Atlantic winter circulation expressed by the North Atlantic Oscillation (NAO; e.g. Hurrell 1995). In addition, use of ARPEGE for downscaling purposes has been evaluated. The work on storm tracks, poleward energy transport and the variability of the NAO include pure observational studies, mainly based on reanalyses, bringing forward new knowledge on extratropical storm tracks, heat transport variations and links between Eurasian snow cover and wintertime NAO

  5. Internal variability in a 1000-yr control simulation with the coupled climate model ECHO-G - II. El Nino Southern Oscillation and North Atlantic Oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Min, Seung-Ki; Hense, Andreas [Univ. of Bonn (Germany). Meteorological Inst.; Legutke, Stephanie [Max Planck Inst. for Meteorology, Hamburg (Germany); Kwon, Won-Tae [Meteorological Research Inst., Seoul (Korea, Republic of)

    2005-08-01

    A 1000-yr control simulation (CTL) performed with the atmosphere-ocean global climate model ECHO-G is analysed with regard to the El Nino Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), the two major natural climatic variabilities, in comparison with observations and other model simulations. The ENSO-related sea surface temperature climate and its seasonal cycle in the tropical Pacific and a single Intertropical Convergence Zone in the eastern tropical Pacific are simulated reasonably, and the ENSO phase-locking to the annual cycle and the subsurface ocean behaviour related to equatorial wave dynamics are also reproduced well. The simulated amplitude of the ENSO signal is however too large and its occurrence is too regular and frequent. Also, the observed westward propagation of zonal wind stress over the equatorial Pacific is not captured by the model. Nevertheless, the ENSO-related teleconnection patterns of near-surface temperature (T2m), precipitation (PCP) and mean sea level pressure (MSLP) are reproduced realistically. The NAO index, defined as the MSLP difference between Gibraltar and Iceland, has a 'white' noise spectrum similar to that of the detrended index obtained from observed data. The correlation and regression patterns of T2m, PCP and MSLP with the NAO index are also successfully simulated. However, the model overestimates the warming over the North Pacific in the high index phase of the NAO, a feature it shares with other coupled models. This might be associated with an enhanced Atlantic/Pacific teleconnection, which is hardly seen in the observations. A detection analysis of the NAO index shows that the observed recent 4060 yr trend cannot be explained by the model's internal variability while the recent 2030 yr trend occurs with a more than 1% chance in ECHO-G CTL.

  6. European Wintertime Windstorms and its Links to Large-Scale Variability Modes

    Science.gov (United States)

    Befort, D. J.; Wild, S.; Walz, M. A.; Knight, J. R.; Lockwood, J. F.; Thornton, H. E.; Hermanson, L.; Bett, P.; Weisheimer, A.; Leckebusch, G. C.

    2017-12-01

    Winter storms associated with extreme wind speeds and heavy precipitation are the most costly natural hazard in several European countries. Improved understanding and seasonal forecast skill of winter storms will thus help society, policy-makers and (re-) insurance industry to be better prepared for such events. We firstly assess the ability to represent extra-tropical windstorms over the Northern Hemisphere of three seasonal forecast ensemble suites: ECMWF System3, ECMWF System4 and GloSea5. Our results show significant skill for inter-annual variability of windstorm frequency over parts of Europe in two of these forecast suites (ECMWF-S4 and GloSea5) indicating the potential use of current seasonal forecast systems. In a regression model we further derive windstorm variability using the forecasted NAO from the seasonal model suites thus estimating the suitability of the NAO as the only predictor. We find that the NAO as the main large-scale mode over Europe can explain some of the achieved skill and is therefore an important source of variability in the seasonal models. However, our results show that the regression model fails to reproduce the skill level of the directly forecast windstorm frequency over large areas of central Europe. This suggests that the seasonal models also capture other sources of variability/predictability of windstorms than the NAO. In order to investigate which other large-scale variability modes steer the interannual variability of windstorms we develop a statistical model using a Poisson GLM. We find that the Scandinavian Pattern (SCA) in fact explains a larger amount of variability for Central Europe during the 20th century than the NAO. This statistical model is able to skilfully reproduce the interannual variability of windstorm frequency especially for the British Isles and Central Europe with correlations up to 0.8.

  7. Rb2Na(NO33: A Congruently Melting UV-NLO Crystal with a Very Strong Second-Harmonic Generation Response

    Directory of Open Access Journals (Sweden)

    Guohong Zou

    2016-04-01

    Full Text Available Crystals of congruently melting noncentrosymmetric (NCS mixed alkali metal nitrate, Rb2Na(NO33, have been grown through solid state reactions. The material possesses layers with NaO8 hexagonal bipyramids and NO3 triangular units. Rb+ cations are residing in the interlayer space. Each NaO8 hexagonal bipyramid shares its corners and edges with two and three NO3 units, respectively, in order to fulfill a highly dense stacking in the unit cell. The NaO8 groups share their six oxygen atoms in equatorial positions with three different NO3 groups to generate a NaO6-NO3 layer with a parallel alignment. The optimized arrangement of the NO3 groups and their high density in the structure together produce a strong second-harmonic generation (SHG response. Powder SHG measurements indicate that Rb2Na(NO33 has a strong SHG efficiency of five times that of KH2PO4 (KDP and is type I phase-matchable. The calculated average nonlinear optical (NLO susceptibility of Rb2Na(NO33 turns out to be the largest value among the NLO materials composed of only [NO3]− anion. In addition, Rb2Na(NO33 exhibits a wide transparency region ranging from UV to near IR, which suggests that the compound is a promising NLO material.

  8. Concepção e avaliação de concentradores solares do tipo disco e lente de fresnel para dessalinização de água

    OpenAIRE

    Prado, Gustavo Otero

    2015-01-01

    O Sol e a principal fonte de energia da Terra. Sua capacidade energetica pode ser considerada inesgotavel, nao produz residuos e possui alocacao adaptavel. Tambem de forma abundante, a agua salgada e disponibilizada no planeta cobrindo a maior parte da superficie terrestre. No entanto, hoje, mais de um bilhao de pessoas em todo o mundo nao tem acesso a agua limpa. Neste cenario, a obtencao de agua potavel pelo processamento de aguas salgadas torna-se fundamental. Logo, esse trabalho teve c...

  9. The Relationship Between Extratropical Cyclone Steering and Blocking Along the North American East Coast

    Science.gov (United States)

    Booth, James F.; Dunn-Sigouin, Etienne; Pfahl, Stephan

    2017-12-01

    The path and speed of extratropical cyclones along the east coast of North America influence their societal impact. This work characterizes the climatological relationship between cyclone track path and speed, and blocking and the North Atlantic Oscillation (NAO). An analysis of Lagrangian cyclone track propagation speed and angle shows that the percentage of cyclones with blocks is larger for cyclones that propagate northward or southeastward, as is the size of the blocked region near the cyclone. Cyclone-centered composites show that propagation of cyclones relative to blocks is consistent with steering by the block: northward tracks more often have a block east/northeast of the cyclone; slow tracks tend to have blocks due north of the cyclone. Comparison with the NAO shows that to first-order blocking and the NAO steer cyclones in a similar manner. However, blocked cyclones are more likely to propagate northward, increasing the likelihood of cyclone related impacts.

  10. Modulation of extreme temperatures in Europe under extreme values of the North Atlantic Oscillation Index.

    Science.gov (United States)

    Beniston, Martin

    2018-03-10

    This paper reports on the influence that extreme values in the tails of the North Atlantic Oscillation (NAO) Index probability density function (PDF) can exert on temperatures in Europe. When the NAO Index enters into its lowest (10% quantile or less) and highest (90% quantile or higher) modes, European temperatures often exhibit large negative or positive departures from their mean values, respectively. Analyses of the joint quantiles of the Index and temperatures (i.e., the simultaneous exceedance of particular quantile thresholds by the two variables) show that temperatures enter into the upper or lower tails of their PDF when the NAO Index also enters into its extreme tails, more often that could be expected from random statistics. Studies of this nature help further our understanding of the manner by which mechanisms of decadal-scale climate variability can influence extremes of temperature-and thus perhaps improve the forecasting of extreme temperatures in weather and climate models. © 2018 New York Academy of Sciences.

  11. The combined influence of the main European circulation patterns on carbon uptake by ecosystems

    Science.gov (United States)

    Bastos, Ana; Gouveia, Célia; Trigo, Ricardo

    2014-05-01

    Understanding how natural climate variability affects carbon uptake by land and ocean pools is particularly relevant to better characterize human impact on the carbon cycle. Recently, we have contributed to assess the major role played by the El-Niño/Southern Oscillation in driving inter-annual variability (IAV) of carbon uptake by land ecosystems and significantly influencing global CO2 air-borne fraction [1]. Despite the prominent role played by ENSO, other important teleconnections on the hemispheric scale have deserved less attention. On the European scale, the main mode of variability is the North-Atlantic Oscillation (NAO), which controls storm tracks position and drives changes in temperature and precipitation over the whole region, affecting vegetation dynamics [2]. Besides NAO, a few additional large scale circulation patterns the Scandinavian (SC) and East-Atlantic (EA) Patterns, are also known to influence significantly the European climate [3]. Different combinations of these teleconnection polarities have been recently shown to modulate the overall role of the NAO impact location and strength, thus affecting winter temperature and precipitation patterns over Europe [4]. This work aims to answer the following questions: (i) how do NAO, EA and SC affect vegetation carbon uptake IAV? (ii) do the interactions between these three modes have a significant impact on land CO2 IAV? (iii) what is the contribution of the different physical variables to ecosystems' response to these modes? (iv) how well do the state-of-the-art Earth System Models (ESMs) from CMIP5 represent these climate variability modes and the corresponding carbon fluxes? We first analyze observational data to assess the relationships between the different combinations of NAO, SC and EA polarities and IAV of gross and net primary production (GPP and NPP, respectively), as well as the most relevant driving factors of ecosystem's response to those variability patterns. Although the winter state

  12. Lesao óssea em leucemias agudas linfoblásticas tipo T e TIPO nao T / nao B

    OpenAIRE

    Martins, Fernando Lopes

    2013-01-01

    Resumo: O AUTOR APRESENTA OS RESULTADOS DO ESTUDO RADIOLÓGICO DE ESQUELETO DE 61 PACIENTES PORTADORES DE LEUCEMIA AGUDA LINFOBLÁSTICA, CORRELACIONANDO A PRESENÇA OU NÃO DE Lesões ÓSSEAS COM A CLASSIFICAÇÃO IMUNOLÓGICA DE LAL TIPO T E TIPO não T / não B

  13. Latest Holocene Climate Variability revealed by a high-resolution multiple Proxy Record off Lisbon (Portugal)

    Science.gov (United States)

    Abrantes, F.; Lebreiro, S.; Ferreira, A.; Gil, I.; Jonsdottir, H.; Rodrigues, T.; Kissel, C.; Grimalt, J.

    2003-04-01

    The North Atlantic Oscillation (NAO) is known to have a major influence on the wintertime climate of the Atlantic basin and surrounding countries, determining precipitation and wind conditions at mid-latitudes. A comparison of Hurrel's NAO index to the mean winter (January-March) discharge of the Iberian Tagus River reveals a good negative correlation to negative NAO, while the years of largest upwelling anomalies, as referred in the literature, appear to be in good agreement with positive NAO. On this basis, a better understanding of the long-term variability of the NAO and Atlantic climate variability can be gained from high-resolution climate records from the Lisbon area. Climate variability of the last 2,000 years is assessed through a multiple proxy study of sedimentary sequences recovered from the Tagus prodelta deposition center, off Lisbon (Western Iberia). Physical properties, XRF and magnetic properties from core logging, grain size, δ18O, TOC, CaCO3, total alkenones, n-alkanes, alkenone SST, diatoms, benthic and planktonic foraminiferal assemblage compositions and fluxes are the proxies employed. The age model for site D13902 is based on AMS C-14 dates from mollusc and planktonic foraminifera shells, the reservoir correction for which was obtained by dating 3 pre-bomb, mollusc shells from the study area. Preliminary results indicate a Little Ice Age (LIA - 1300 - 1600 AD) alkenone derived SSTs around 15 degC followed by a sharp and rapid increase towards 19 degC. In spite the strong variability observed for most records, this low temperature interval is marked by a general increase in organic carbon, total alkenone concentration, diatom and foraminiferal abundances, as well as an increase in the sediment fine fraction and XRF determined Fe content, pointing to important river input and higher productivity. The Medieval Warm Period (1080 - 1300 AD) is characterized by 17-18 degC SSTs, increased mean grain size, but lower magnetic susceptibility and Fe

  14. Sodium Octanoate Modulates the Innate Immune Response of Bovine Mammary Epithelial Cells through the TLR2/P38/JNK/ERK1/2 Pathway: Implications during Staphylococcus aureus Internalization.

    Science.gov (United States)

    Alva-Murillo, Nayeli; Ochoa-Zarzosa, Alejandra; López-Meza, Joel E

    2017-01-01

    Bovine mammary epithelial cells (bMECs) contribute to mammary gland defense against invading pathogens, such as Staphylococcus aureus (intracellular facultative), which is recognized by TLR2. In a previous report, we showed that sodium octanoate [NaO, a medium chain fatty acid (C8)] induces (0.25 mM) or inhibits (1 mM) S. aureus internalization into bMECs and differentially regulates the innate immune response (IIR). However, the molecular mechanisms have not been described, which was the aim of this study. The results showed that α5β1 integrin membrane abundance (MA) was increased in 0.25 mM NaO-treated cells, but TLR2 or CD36 MA was not modified. When these receptors were blocked individually, 0.25 mM NaO-increased S. aureus internalization was notably reduced. Interestingly, in this condition, the IIR of the bMECs was impaired because MAPK (p38, JNK, and ERK1/2) phosphorylation and the activation of transcription factors related to these pathways were decreased. In addition, the 1 mM NaO treatment induced TLR2 MA, but neither the integrin nor CD36 MA was modified. The reduction in S. aureus internalization induced by 1 mM NaO was increased further when TLR2 was blocked. In addition, the phosphorylation levels of the MAPKs increased, and 13 transcriptional factors related to the IIR were slightly activated (CBF, CDP, c-Myb, AP-1, Ets-1/Pea-3, FAST-1, GAS/ISRE, AP-2, NFAT-1, OCT-1, RAR/DR-5, RXR/DR-1, and Stat-3). Moreover, the 1 mM NaO treatment up-regulated gene expression of IL-8 and RANTES and secretion of IL-1β. Notably, when 1 mM NaO-treated bMECs were challenged with S. aureus , the gene expression of IL-8 and IL-10 increased, while IL-1β secretion was reduced. In conclusion, our results showed that α5β1 integrin, TLR2 and CD36 are involved in 0.25 mM NaO-increased S. aureus internalization in bMECs. In addition, 1 mM NaO activates bMECs via the TLR2 signaling pathways (p38, JNK, and ERK1/2), which improves IIR before S. aureus invasion. Additionally

  15. Impact of the North Atlantic Oscillation on the trans-Atlantic migrations of the European eel (Anguilla anguilla)

    Science.gov (United States)

    Kettle, A. James; Bakker, Dorothee C. E.; Haines, Keith

    2008-09-01

    Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwater eel (Anguilla anguilla) show a decrease over the past 20 years. The long-term trends in the time series mask an interannual fluctuation, which becomes apparent on the application of a high-pass filter and autocorrelation analysis. Both the FAO landings and the glass eel catches show interannual fluctuations with a repeat period of 6-8 years, similar to the period of the North Atlantic Oscillation (NAO). Most glass eel catch monitoring stations are in phase. The glass eel catches show a significant negative correlation with the NAO lagged by 0-2 years, consistent with the hypothesis that the positive NAO phase has an adverse impact on the larval survival in and migration from the Sargasso Sea spawning location, one year prior to the arrival of the glass eels in Europe and North Africa. The FAO landings can be divided into two groups of different phase that have an approximate correspondence to the NAO dipole in winter rainfall in Europe and North Africa. One group (P) comprises Denmark, Ireland, Morocco, Netherlands, Norway, Sweden, Tunisia, and the United Kingdom, and the other group (N) comprises France, Germany, Italy, Poland, Portugal, Spain, and Turkey. At least for the interannual fluctuations, the success of the glass eel fishery (and eel recruitment) may be coupled with the number of migrating silver eels from the N group of countries and uncoupled with the P group of countries.

  16. Production of hydrogen with methane decomposition using Ni-Mn/Ce-ZrO{sub 2} catalysts; Produccion de hidrogeno via descomposicion de metano mediante catalizadores de Ni-Mn/Ce-ZrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, C; Hernandez-Pichardo, M L; Valenzuela, M A [Instituto Politecnico Nacional-ESIQIE, Mexico, D.F. (Mexico); Del Angel, P; Montoya de la Fuente, J.A. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2009-09-15

    The catalytic decomposition of methane makes it possible to obtain CO and CO{sub 2} free hydrogen, which is a desirable characteristic for fuel cell applications. In addition, this method simultaneously obtains diverse carbon nanostructures with a large variety of applications. This work prepared catalysts with different Ni contents supported by Ce-Zr mixed oxides and doped with manganese to promote activity. The supports were synthesized with surfactant-assisted coprecipitation. The Ni and Mn deposits were performed using conventional impregnation for evaluation in the methane decomposition catalyst at 500 degrees Celsius. It was observed that with the incorporation of 1% of Mn into the Ni0 active phase, the conversion of methane into hydrogen and carbon nanostructures increased. The results of reduction at the programmed temperature indicate that the addition of Mn enables the formation of different NiO{sub x} species, increasing dispersion and the degree of reduction to Ni0. Analyses with electron and transmission microscopy show the formation of distinct species of carbon, including nanotubes, nanofibers and concentric onion-like structures, as well as a significant formation of encapsulated Ni0 particles. [Spanish] La descomposicion catalitica de metano permite la obtencion de hidrogeno libre de CO y CO{sub 2}, lo cual es una caracteristica deseable para su aplicacion en celdas de combustible. Ademas, por esta ruta, simultaneamente se obtienen diversas nanoestructuras de carbono con una gran variedad de aplicaciones. En este trabajo se prepararon catalizadores con diferentes contenidos de Ni soportados en oxidos mixtos Ce-Zr y se doparon con manganeso como promotor de actividad. Los soportes se sintetizaron por coprecipitacion asistida por surfactante y el deposito del Ni y del Mn se efectuo por impregnacion convencional para su evaluacion en la descomposicion catalitica de metano a 500 grados centigrados. Se observo que mediante la incorporacion de 1% de Mn a

  17. The role of salinity in the decadal variability of the North Atlantic meridional overturning circulation

    Energy Technology Data Exchange (ETDEWEB)

    Frankignoul, Claude [Universite Pierre et Marie Curie, Paris 6, LOCEAN/IPSL, Paris Cedex 05 (France); Deshayes, Julie; Curry, Ruth [Woods Hole Oceanographic Institution, Woods Hole, MA (United States)

    2009-11-15

    An OGCM hindcast is used to investigate the linkages between North Atlantic Ocean salinity and circulation changes during 1963-2003. The focus is on the eastern subpolar region consisting of the Irminger Sea and the eastern North Atlantic where a careful assessment shows that the simulated interannual to decadal salinity changes in the upper 1,500 m reproduce well those derived from the available record of hydrographic measurements. In the model, the variability of the Atlantic meridional overturning circulation (MOC) is primarily driven by changes in deep water formation taking place in the Irminger Sea and, to a lesser extent, the Labrador Sea. Both are strongly influenced by the North Atlantic Oscillation (NAO). The modeled interannual to decadal salinity changes in the subpolar basins are mostly controlled by circulation-driven anomalies of freshwater flux convergence, although surface salinity restoring to climatology and other boundary fluxes each account for approximately 25% of the variance. The NAO plays an important role: a positive NAO phase is associated with increased precipitation, reduced northward salt transport by the wind-driven intergyre gyre, and increased southward flows of freshwater across the Greenland-Scotland ridge. Since the NAO largely controlled deep convection in the subpolar gyre, fresher waters are found near the sinking region during convective events. This markedly differs from the active influence on the MOC that salinity exerts at decadal and longer timescales in most coupled models. The intensification of the MOC that follows a positive NAO phase by about 2 years does not lead to an increase in the northward salt transport into the subpolar domain at low frequencies because it is cancelled by the concomitant intensification of the subpolar gyre which shifts the subpolar front eastward and reduces the northward salt transport by the North Atlantic Current waters. This differs again from most coupled models, where the gyre

  18. Winter NH low-frequency variability in a hierarchy of low-order stochastic dynamical models of earth-atmosphere system

    Science.gov (United States)

    Zhao, Nan

    2018-02-01

    The origin of winter Northern Hemispheric low-frequency variability (hereafter, LFV) is regarded to be related to the coupled earth-atmosphere system characterized by the interaction of the jet stream with mid-latitude mountain ranges. On the other hand, observed LFV usually appears as transitions among multiple planetary-scale flow regimes of Northern Hemisphere like NAO + , AO +, AO - and NAO - . Moreover, the interaction between synoptic-scale eddies and the planetary-scale disturbance is also inevitable in the origin of LFV. These raise a question regarding how to incorporate all these aspects into just one framework to demonstrate (1) a planetary-scale dynamics of interaction of the jet stream with mid-latitude mountain ranges can really produce LFV, (2) such a dynamics can be responsible for the existence of above multiple flow regimes, and (3) the role of interaction with eddy is also clarified. For this purpose, a hierarchy of low-order stochastic dynamical models of the coupled earth-atmosphere system derived empirically from different timescale ranges of indices of Arctic Oscillation (AO), North Atlantic Oscillation (NAO), Pacific/North American (PNA), and length of day (LOD) and related probability density function (PDF) analysis are employed in this study. The results seem to suggest that the origin of LFV cannot be understood completely within the planetary-scale dynamics of the interaction of the jet stream with mid-latitude mountain ranges, because (1) the existence of multiple flow regimes such as NAO+, AO+, AO- and NAO- resulted from processes with timescales much longer than LFV itself, which may have underlying dynamics other than topography-jet stream interaction, and (2) we find LFV seems not necessarily to come directly from the planetary-scale dynamics of the interaction of the jet stream with mid-latitude mountain, although it can produce similar oscillatory behavior. The feedback/forcing of synoptic-scale eddies on the planetary

  19. Social robots in advanced dementia

    Directory of Open Access Journals (Sweden)

    Meritxell eValentí Soler

    2015-09-01

    Full Text Available Aims: Testing the effect of the experimental robot-based therapeutic sessions for patients with dementia in: a controlled study of parallel groups of nursing home patients comparing the effects of therapy sessions utilizing a humanoid robot (NAO, an animal-shaped robot (PARO, or a trained dog (DOG, with conventional therapy (CONTROL on symptoms of dementia; and an experience for patients who attend a day care center, comparing symptom prevalence and severity before and after sessions utilizing NAO and PARO. Methods: In the nursing home, patients were randomly assigned by blocks, based on dementia severity, to one of the 3 therapeutic groups to compare: CONTROL, PARO and NAO (phase 1 and CONTROL, PARO and DOG (phase 2. In the day care center, all patients received therapy with NAO (phase 1 and PARO (phase 2. Therapy sessions were held 2 days/week for 3 months. Evaluation at baseline and follow-up was carried out by blind raters using: the Global Deterioration Scale (GDS, the Severe Mini Mental State Examination (sMMSE, the Mini Mental State Examination (MMSE, the Neuropsychiatric Inventory (NPI, the Apathy Scale for Institutionalized Patients with Dementia Nursing Home version (APADEM-NH, the Apathy Inventory (AI and the Quality of Life Scale (QUALID. Statistical analysis included descriptive statistics and non parametric tests performed by a blinded investigator. Results: In the nursing home, 101 patients (phase 1 and 110 patients (phase 2 were included. There were no significant differences at baseline. The relevant changes at follow-up were: (phase 1 patients in the robot groups showed an improvement in apathy; patients in NAO group showed a decline in cognition as measured by the MMSE scores, but not the sMMSE; the robot groups showed no significant changes between them; (phase 2 QUALID scores increased in the PARO group. In the day care center, 20 patients (phase 1 and 17 patients (phase 2 were included. The main findings were: (phase 1 imp

  20. Cooperation for Common Use of SEE Astronomical Database as a Regional Virtual Observatory in Different Scientific Projects

    Science.gov (United States)

    Pinigin, Gennady; Protsyuk, Yuri; Shulga, Alexander

    The activity of scientific collaborative and co-operative research between South-Eastern European (SEE) observatories is enlarged in the last time. The creation of a common database as a regional virtual observatory is very desirable. The creation of astronomical information resource with a capability of interactive access to databases and telescopes on the base of the general astronomical database of the SEE countries is presented. This resource may be connected with the European network. A short description of the NAO database is presented. The total amount of the NAO information makes about 90 GB, the one obtained from other sources - about 15 GB. The mean diurnal level of the new astronomical information produced with the NAO CCD instruments makes from 300 MB up to 2 GB, depending on the purposes and conditions of observations. The majority of observational data is stored in FITS format. Possibility of using of VO-table format for displaying these data in the Internet is studied. Activities on development and the further refinement of storage, exchange and data processing standards are conducted.

  1. The North Atlantic Oscillation and sea surface temperature affect loggerhead abundance around the Strait of Gibraltar

    Directory of Open Access Journals (Sweden)

    José C. Báez

    2011-04-01

    Full Text Available The aim of this study was to explore the possible link between variations in the North Atlantic Oscillation (NAO and sea surface temperature (SST and the abundance of loggerhead turtles around the Strait of Gibraltar, using stranding data for the Andalusian coastal area as a proxy for abundance. The annual average SST (from November to October in the Gulf of Cadiz was negatively associated with the total number of loggerhead strandings each year from November 1997 to October 2006 in the Gulf of Cadiz and the Alboran Sea. The average NAO index was positively associated with the number of strandings in the Gulf of Cadiz in the following year. Prevailing westerly winds during positive NAO phases and the subsequent delayed decrease in SST may lead to turtles from the west Atlantic accumulating in the Gulf of Cadiz and unsuccessfully attempting to return. Secondary causes, such as buoyancy, cold stunning, longline fisheries, net fisheries, debilitated turtle syndrome, and trauma may also increase the number of turtle strandings.

  2. Inter-annual dynamics of the Barents Sea red king crab (Paralithodes camtschaticus) stock indices in relation to environmental factors

    Science.gov (United States)

    Dvoretsky, Alexander G.; Dvoretsky, Vladimir G.

    2016-12-01

    Knowledge of relationships between environmental variables and biological processes can greatly improve fisheries assessment and management in commercially important species. We analyzed the effects of environmental factors (climatic indices and water temperature) on the stock characteristics (total population number, number of pre-recruits and number of legal males) of the red king crab (Paralithodes camtschaticus), an introduced species in the Barents Sea. Stock trends in red king crab appear to be related to decadal climate shifts. Abundances were negatively related to the North Atlantic Oscillation index (NAO) in August and positively related to water temperature in late winter-early summer. Total and commercial stock abundance were negatively correlated with the lag-1 Arctic Oscillation index (AO) in August and the lag-2 winter NAO index. The total number of P. camtschaticus was most strongly associated with water temperature in spring and summer and NAO/AO indices in April and May. Lagged NAO indices in February and August (9 or 10 yr) had a positive relationship to the commercial stock of P. camtschaticus. These findings suggest that temperature conditions of current and previous year affect natural mortality of larvae and juvenile red king crabs. Warmer temperature conditions lead to increased biomass of red king crab food items. Negative correlations between climatic indices and the red king crab stocks may be associated with predator pressure on juvenile red king crabs or higher mortality because of predator or parasite pressure and diseases. The associations between stock indices and environmental variables could help better predict recruitment patterns of P. camtschaticus.

  3. Hiatus in global warming - example of water temperature of the Danube River at Bogojevo gauge (Serbia

    Directory of Open Access Journals (Sweden)

    Ducić Vladan

    2015-01-01

    Full Text Available The research included trends in water temperature of the Danube River at Bogojevo gauge and surface air temperature at the nearby meteorological station Sombor, as well as an analysis of the results obtained in relation to the claims of the existence of the hiatus in global air temperature increase in the period 1998-2012. In the period 1961-2013, there was a statistically significant increase in the mean annual water temperature (0.039°C/year, as well as all the average monthly values. However, with annual values for the period 1998-2013, there was a decrease. The longest periods of negative trend (27 years were recorded for January and February. A high correlation was found between the surface air temperature and water temperature for all monthly and seasonal values. In the mean annual air temperature the presence of the hiatus is not observed, but a negative trend is recorded in March (32 years, December (43 years and February (49 years. The highest correlations between water temperature and North Atlantic Oscillation (NAO, Arctic Oscillation (AO and Atlantic Multidecadal Oscillation (AMO were obtained for the NAO in January (0.60, the AMO in autumn (0.52 and the NAO in winter (0.51. For surface air temperature, the highest correlations were registered for the AMO in summer (0.49 and the NAO in winter (0.42. The results indicate the dominant role of natural factors in the decrease of winter air temperature and water temperature of the Danube. [Projekat Ministarstva nauke Republike Srbije, br. III47007

  4. Identifying the Climatic Conditions in Iraq by Tracking Down Cooling Events in the North Atlantic Ocean in the Period 3000–0 BC

    Directory of Open Access Journals (Sweden)

    Muslih Khamis D.

    2014-09-01

    Full Text Available North Atlantic Oscillation (NAO, monthly averages of precipitation in the Baghdad station, and petrologic tracer proxy data for ocean properties in the North Atlantic (NA have been used in an attempt to identify climatic conditions in Iraq during the study period. The study showed that contemporary changes in precipitation in Iraq are associated with NAO, as a negative relationship is found between them. Moreover, the study found that there is a strong negative correlation between NAOI and SST in NA, where drift ice indices explain between 33–36% of the NAOI variability.

  5. Probabilidade Indutiva e sua Relação com o Princí­pio de Casualidade

    Directory of Open Access Journals (Sweden)

    Lia Maria Alcoforado de Melo

    2010-10-01

    Full Text Available A questao do estabelecimento de quais argumentos indutivos tem maior probabilidade de se aproximar mais da verdade, liga-se com maior intensidade aos raciocinios que envolvem generaliza<;oes humeanas. 0 principio de causalidade, suporte basico da legitimidade da indu<;ao cientifica, ediscutido neste trabalho a partir das obje¢es de HUME, a existencia de uma logica que garanta sua racionalidade. Objetivou-se construir uma arqumentacao justificativa que mostrasse que HUME nao prova atraves de sua teoria cetica, que 0 principio causal e irracional; muito embora que nao se tenha ainda conseguido, cornprova-lo como racional.

  6. Effect of Yi-nao-jie-yu decoction on γ-aminobutyric acid type A receptor in the hippocampus and serum inflammatory factors in a rat model of poststroke anxiety

    Directory of Open Access Journals (Sweden)

    Zhang W

    2016-11-01

    Full Text Available Wen Zhang,1 Ruizhen Zhao,1 Xiaoli Li,1 Xia Cui,1 Zijun Zhao,1 Yingqiu Mao,2 Fengzhi Wu,3 Qisheng Tang1 1Department of Encephalopathy, The Third Affiliated Hospital, 2Center of Scientific Research, 3Center of Journals, Beijing University of Chinese Medicine, Chaoyang District, Beijing, People’s Republic of China Background: The Yi-nao-jie-yu decoction (YNJYD is a herbal preparation widely used in the clinics of traditional Chinese medicine and has been recently used as an important new therapeutic agent in poststroke anxiety (PSA. The neuroendocrine–immune system plays an important role in PSA mechanisms, although the modulating effects of YNJYD remain unknown. This study investigated the potential effects of YNJYD on the neuroendocrine–immune system in a rat model of PSA.Materials and methods: The PSA model was induced by injecting collagenase (type VII into the right globus pallidus, accompanied by empty water bottle stimulation for 2 weeks. The sham group and the PSA model group were gavaged with saline, while the treatment groups received buspirone (BuSpar or YNJYD. Behavior was evaluated with the open field test and elevated plus maze once a week. Pathological changes were observed by hematoxylin and eosin staining. Serum levels of tumor necrosis factor, interleukin (IL-6, adrenocorticotropic hormone, thyroid stimulating hormone, free triiodothyronine, free thyroxine, IL-1α, and cortisol were detected by radioimmunoassay. Expression of the γ-aminobutyric acid type A receptor (GABAAR α2 subunit was examined by Western blot and real-time polymerase chain reaction.Results: YNJYD-treated rats exhibited significantly better recovery than BuSpar-treated rats at 21 days and 28 days in the open field test and elevated plus maze. Hematoxylin and eosin staining revealed neural repair in the hippocampus in the treatment groups. Serum levels of IL-1α in the YNJYD group were significantly less than those in the model group and the Bu

  7. Problems caused by dioxins and furans. Pt. 2. Controls and degradation methods; `I problemi causati da diossine e furani. Pt. 2. Metodi di contenimento e di degradazione

    Energy Technology Data Exchange (ETDEWEB)

    Gervasini, A.; Vezzoli, G.C.; Ragaini, V. [Milan Univ. (Italy). Dip. di Chimica Fisica ed Elettrochimica

    1999-01-01

    The environmental effects and the toxicity towards human health caused by polychlorodibenzodioxins and furans (PCDD/F) is related to the peculiar properties of the various isomers and to the geographic and climatic characteristics of the emission sources. The different methods and techniques of control and degradation introduced in the last years have to take into account the type and the location of the source. A survey of the principal methods of degradation of PCDD/F, thermal, chemical, photochemical, and catalytic decomposition, with their advantages and limits is presented. [Italiano] L`impatto che policlorodibenzodiossine e furani (PCDD/F) provocano sull`ambiente e sulla salute dell`uomo e` legato oltre che alle proprieta` peculiari dei vari congeneri alle caratteristiche geografiche e climatologiche del luogo in cui vengono emesse. Le metodologie di contenimento e le tecniche di degradazione messe a punto negli ultimi anni devono tenere in considerazione anche l`ubicazione e il tipo di sorgente dell`emissione. Viene fornita una panoramica sui principali metodi di degradazione di PCDD/F discutendo vantaggi e limiti delle varie tecniche: decomposizione termica, chimica, fotochimica e catalitica.

  8. Coupled decadal variability of the North Atlantic Oscillation, regional rainfall and karst spring discharges in the Campania region (southern Italy

    Directory of Open Access Journals (Sweden)

    P. De Vita

    2012-05-01

    Full Text Available Thus far, studies on climate change have focused mainly on the variability of the atmospheric and surface components of the hydrologic cycle, investigating the impact of this variability on the environment, especially with respect to the risks of desertification, droughts and floods. Conversely, the impacts of climate change on the recharge of aquifers and on the variability of groundwater flow have been less investigated, especially in Mediterranean karst areas whose water supply systems depend heavily upon groundwater exploitation.

    In this paper, long-term climatic variability and its influence on groundwater recharge were analysed by examining decadal patterns of precipitation, air temperature and spring discharges in the Campania region (southern Italy, coupled with the North Atlantic Oscillation (NAO.

    The time series of precipitation and air temperature were gathered over 90 yr, from 1921 to 2010, using 18 rain gauges and 9 air temperature stations with the most continuous functioning. The time series of the winter NAO index and of the discharges of 3 karst springs, selected from those feeding the major aqueducts systems, were collected for the same period.

    Regional normalised indexes of the precipitation, air temperature and karst spring discharges were calculated, and different methods were applied to analyse the related time series, including long-term trend analysis using smoothing numerical techniques, cross-correlation and Fourier analysis.

    The investigation of the normalised indexes highlighted the existence of long-term complex periodicities, from 2 to more than 30 yr, with differences in average values of up to approximately ±30% for precipitation and karst spring discharges, which were both strongly correlated with the winter NAO index.

    Although the effects of the North Atlantic Oscillation (NAO had already been demonstrated in the long-term precipitation and streamflow patterns of

  9. Rotational atmospheric circulation during North Atlantic-European winter: the influence of ENSO

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Serrano, J. [UCM, Departamento de Geofisica y Meteorologia, Madrid (Spain); Institut Catala de Ciencies del Clima (IC3), Barcelona (Spain); Rodriguez-Fonseca, B.; Zurita-Gotor, P.; Camara, A. de la [UCM, Departamento de Geofisica y Meteorologia, Madrid (Spain); Blade, I. [UB, Departament d' Astronomia i Meteorologia, Barcelona (Spain)

    2011-11-15

    The dominant variability modes of the North Atlantic-European rotational flow are examined by applying a principal component analysis (PCA/EOF) to the 200 hPa streamfunction mid-winter anomalies (Jan-Feb monthly means). The results reveal that, when this norm is used, the leading mode (EOF1) does not correspond to the traditional North Atlantic Oscillation (NAO, which appears in our analysis as the second leading mode, EOF2) but is the local manifestation of the leading hemispheric streamfunction EOF. The regression of this regional mode onto the global SST field exhibits a clear El Nino signature, with no signal over the Atlantic, while the associated upper height anomalies resemble the Tropical/Northern Hemisphere (TNH) pattern. East of North America, this TNH-like wavetrain produces a meridional dipole-like pattern at lower levels. Although in some ways this pattern resembles the NAO (EOF2), the dynamics of these two modes are very different in that only EOF2 is associated with a latitudinal shift of the North Atlantic stormtrack. Thus, the choice of the streamfunction norm in the EOF analysis allows the separation of two different phenomena that can produce similar dipolar surface pressure anomalies over the North Atlantic but that have different impact on European climate. These two modes also differ on their contribution to variability at lower levels: while NAO-EOF2 is mostly confined to the North Atlantic, TNH-EOF1 has a more annular, global character. At upper levels NAO-EOF2 also produces a global pattern but with no annular structure, reminiscent of the ''circumglobal'' teleconnection. (orig.)

  10. Numerical Analysis Objects

    Science.gov (United States)

    Henderson, Michael

    1997-08-01

    The Numerical Analysis Objects project (NAO) is a project in the Mathematics Department of IBM's TJ Watson Research Center. While there are plenty of numerical tools available today, it is not an easy task to combine them into a custom application. NAO is directed at the dual problems of building applications from a set of tools, and creating those tools. There are several "reuse" projects, which focus on the problems of identifying and cataloging tools. NAO is directed at the specific context of scientific computing. Because the type of tools is restricted, problems such as tools with incompatible data structures for input and output, and dissimilar interfaces to tools which solve similar problems can be addressed. The approach we've taken is to define interfaces to those objects used in numerical analysis, such as geometries, functions and operators, and to start collecting (and building) a set of tools which use these interfaces. We have written a class library (a set of abstract classes and implementations) in C++ which demonstrates the approach. Besides the classes, the class library includes "stub" routines which allow the library to be used from C or Fortran, and an interface to a Visual Programming Language. The library has been used to build a simulator for petroleum reservoirs, using a set of tools for discretizing nonlinear differential equations that we have written, and includes "wrapped" versions of packages from the Netlib repository. Documentation can be found on the Web at "http://www.research.ibm.com/nao". I will describe the objects and their interfaces, and give examples ranging from mesh generation to solving differential equations.

  11. Calcium disodium hexathiodiphosphate(IV octahydrate

    Directory of Open Access Journals (Sweden)

    Claus Ehrhardt

    2010-08-01

    Full Text Available Single crystals of the title compound, CaNa2(P2S6·8H2O, were obtained by adding calcium hydroxide to an aqueous solution of Na4(P2S6·6H2O. The structure is isotypic with that of its strontium analogue and consists of one Ca2+ cation, two Na+ cations, one-half of a centrosymmetric (P2S64− anion with staggered confirmation and four water molecules in the asymmetric unit. The crystal structure can be described as being built up from layers of cations and anions extending parallel to (101. Within a layer, each CaO8 polyhedron is connected via edge-sharing to two NaO4S2 octahedra and to one NaO2S4 octaedron. The NaO4S2 octahedra are, in turn, linked with two (P2S64− anions through common corners. Various O—H...S hydrogen-bonding interactions lead to cohesion of adjacent layers. The Ca2+ and one Na+ cation are situated on a twofold rotation axis and the second Na+ cation is situated on an inversion centre.

  12. Winter Precipitation in North America and the Pacific-North America Pattern in GEOS-S2Sv2 Seasonal Hindcast

    Science.gov (United States)

    Li, Zhao; Molod, Andrea; Schubert, Siegfried

    2018-01-01

    Reliable prediction of precipitation remains one of the most pivotal and complex challenges in seasonal forecasting. Previous studies show that various large-scale climate modes, such as ENSO, PNA and NAO play significant role in winter precipitation variability over the Northern America. The influences are most pronounced in years of strong indices of such climate modes. This study evaluates model bias, predictability and forecast skills of monthly winter precipitation in GEOS5-S2S 2.0 retrospective forecast from 1981 to 2016, with emphasis on the forecast skill of precipitation over North America during the extreme events of ENSO, PNA and NAO by applying EOF and composite analysis.

  13. The Role of Network Administrative Organizations in the Development of Social Capital in Inter‐Organizational Food Networks

    Directory of Open Access Journals (Sweden)

    Virginie M. Lefebvre

    2013-02-01

    Full Text Available This paper is concerned with the role of network administrative organizations (NAOs in the development of social capital in inter‐organizational networks aiming at supporting their members to innovate in the food sector through interacting with one another. A multi‐case study approach is used whereby three Belgian inter‐organizational networks are investigated i.e. Wagralim, Réseau‐Club and Flanders Food. Our study shows that there are many options available to NAOs to build social capital within the networks they are responsible for; options which we propose to categorize in three main distinct groups: creation of boundary objects, careful selection of members and effective communication.

  14. Planches

    OpenAIRE

    2016-01-01

    Fig. 2 - Karşi kilise, vue générale vers l’ouest Fig. 3 - Le panneau des donatrices (mur ouest) Fig. 4 - Le panneau des donateurs (mur nord) Fig. 5 - Partie nord-est du naos ; de haut en bas : Myrophores au sépulcre et Anastasis ; Paradis ; saint Artémios et le panneau des donateurs Fig. 6 - Mur sud : Constantin et Hélène, avec l’invocation de Michel Plakidas Fig. 7 - Vue vers le sud-est Fig. 8 - Voûte du naos, versant sud : Cène, Trahison de Judas, Baptême ; Dormition de la Vierge, Jeu...

  15. Preparation and characterization of novel nanocomposites of inorganic/polysaccharide type =

    Science.gov (United States)

    Oliveira, Fabiane Costa

    O uso de polimeros naturais no ambito da preparacao de nanocompositos nao tem sido tao amplamente estudado quando comparado com os polimeros sinteticos. Assim, esta tese tem como objectivo estudar metodologias para a preparacao de novos materiais nanocompositos sob a forma de dispersoes e filmes utilizando polissacarideos como matriz. A tese esta dividida em cinco capitulos sendo o ultimo capitulo dedicado as conclusoes gerais e a sugestoes para trabalhos futuros. Inicialmente e apresentada uma breve revisao bibliografica sobre os principais temas colocando esta tese em contexto. Consideracoes sobre o uso de polimeros naturais e a sua combinacao com a utilizacao de nanoparticulas inorganicas para a fabricacao de novos bionanocomposites sao descritas e os objectivos e outline da tese sao tambem apresentados. No segundo capitulo, a preparacao de particulas de silica puras ou modificadas bem como a sua caracterizacao por FTIR, SEM, TEM, TGA, DLS (tamanho e potencial zeta) e medicoes de angulo de contacto sao discutidas. De modo a melhorar a compatibilidade da silica com os polissacarideos, as particulas SiO2 foram modificados com dois compostos do tipo organosilano: 3- metacril-oxipropil-trimetoxissilano (MPS) e 3-aminopropil-trimetoxissilano (APS). As particulas SiO2 MPS foram posteriormente encapsuladas com de poli(metacrilato de glicidilo) utilizando a tecnica de polimerizacao em emulsao. A utilizacao dos nanocompositos resultantes na preparacao de dispersoes de bionanocompositos nao foi bem sucedida e por esse motivo nao os estudos nao foram prosseguidos. O uso de SiO2 APS na preparacao de dispersoes bionanocomposite foi eficiente. No terceiro capitulo e apresentada uma revisao sobre dispersoes bionanocompositas e respectiva caracterizacao destacando aspectos fundamentais sobre reologia e microestrutura. Em seguida, e discutido o estudo sistematico realizado sobre o comportamento reologico de dispersoes de SiO2 utilizando tres polissacarideos distintos no que

  16. Impact of ice sheet induced North Atlantic oscillation on East Asian summer monsoon during an interglacial 500,000 years ago

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, S.; Yin, Q.Z.; Berger, A.; Muri, H. [Universite Catholique de Louvain, Earth and Life Institute (ELI), Georges Lemaitre Centre for Earth and Climate Research (TECLIM), Louvain la Neuve (Belgium)

    2012-09-15

    Marine Isotope Stage (MIS) 13, an interglacial about 500,000 years ago, is unique due to an exceptionally strong East Asia summer monsoon (EASM) occurring in a relatively cool climate with low greenhouse gas concentrations (GHG). This paper attempts to find one of the possible mechanisms for this seeming paradox. Simulations with an Earth System model LOVECLIM show that the presence of ice sheets over North America and Eurasia during MIS-13 induces a positive phase of the winter North Atlantic Oscillation (NAO) like feature. The ocean having a longer memory than the atmosphere, the oceanic anomalies associated with NAO persists until summer. The signals of summer NAO are transmitted to East Asia to reinforce the monsoon there through the stationary waves excited at the Asian Jet entrance. The geopotential height shows clearly a mid-latitude wave train with positive anomalies over the eastern Mediterranean/Caspian Sea and the Okhotsk Sea and a negative anomaly over Lake Baikal. This reinforces the effect of the high-latitude wave train induced independently by the Eurasian ice sheet topography as shown in previous study. These features reinforce the Meiyu front and enhance the precipitation over East Asia. The results obtained from LOVECLIM are further confirmed by an atmospheric general circulation model, ARPEGE. (orig.)

  17. The boreal winter Madden-Julian Oscillation's influence on summertime precipitation in the greater Caribbean

    Science.gov (United States)

    Curtis, Scott; Gamble, Douglas W.

    2016-07-01

    Precipitation totals in the greater Caribbean are known to be affected by interannual variability. In particular, dry conditions in the spring-summer have been physically linked to the positive phase of North Atlantic Oscillation (NAO) in the literature. In this study, it was found through regression analysis that an active Madden-Julian Oscillation (MJO) in winter geographically focused over the Maritime Continent contributes to a positive NAO in March via the generation of Rossby waves in the Northern Hemisphere. Specifically, a negative Pacific-North American pattern develops in the winter and transitions to an Atlantic pattern in spring. The positive NAO is a transient feature of this evolving wave train, but a center of significant positive 200 hPa geopotential heights is entrenched over the southeast U.S. throughout the February to May time period and is manifested as high pressure at the surface. The southern flank of this system increases the speeds of the trade winds and leads to a cooling of the Caribbean sea surface temperatures and, thus, convection suppression and reduced precipitation. Thus, this study advances our understanding of the climate of the greater Caribbean by using climate teleconnections to relate the MJO to rainfall in the region.

  18. Long term changes in flooding and heavy rainfall associated with North Atlantic tropical cyclones: Roles of the North Atlantic Oscillation and El Niño-Southern Oscillation

    Science.gov (United States)

    Aryal, Yog N.; Villarini, Gabriele; Zhang, Wei; Vecchi, Gabriel A.

    2018-04-01

    The aim of this study is to examine the contribution of North Atlantic tropical cyclones (TCs) to flooding and heavy rainfall across the continental United States. Analyses highlight the spatial variability in these hazards, their temporal changes in terms of frequency and magnitude, and their connection to large-scale climate, in particular to the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO). We use long-term stream and rain gage measurements, and our analyses are based on annual maxima (AMs) and peaks-over-threshold (POTs). TCs contribute to ∼20-30% of AMs and POTs over Florida and coastal areas of the eastern United States, and the contribution decreases as we move inland. We do not detect statistically significant trends in the magnitude or frequency of TC floods. Regarding the role of climate, NAO and ENSO do not play a large role in controlling the frequency and magnitude of TC flooding. The connection between heavy rainfall and TCs is comparable to what observed in terms of flooding. Unlike flooding, NAO plays a significant role in TC-related extreme rainfall along the U.S. East Coast, while ENSO is most strongly linked to the TC precipitation in Texas.

  19. Sensitivity of marine protected area network connectivity to atmospheric variability.

    Science.gov (United States)

    Fox, Alan D; Henry, Lea-Anne; Corne, David W; Roberts, J Murray

    2016-11-01

    International efforts are underway to establish well-connected systems of marine protected areas (MPAs) covering at least 10% of the ocean by 2020. But the nature and dynamics of ocean ecosystem connectivity are poorly understood, with unresolved effects of climate variability. We used 40-year runs of a particle tracking model to examine the sensitivity of an MPA network for habitat-forming cold-water corals in the northeast Atlantic to changes in larval dispersal driven by atmospheric cycles and larval behaviour. Trajectories of Lophelia pertusa larvae were strongly correlated to the North Atlantic Oscillation (NAO), the dominant pattern of interannual atmospheric circulation variability over the northeast Atlantic. Variability in trajectories significantly altered network connectivity and source-sink dynamics, with positive phase NAO conditions producing a well-connected but asymmetrical network connected from west to east. Negative phase NAO produced reduced connectivity, but notably some larvae tracked westward-flowing currents towards coral populations on the mid-Atlantic ridge. Graph theoretical metrics demonstrate critical roles played by seamounts and offshore banks in larval supply and maintaining connectivity across the network. Larval longevity and behaviour mediated dispersal and connectivity, with shorter lived and passive larvae associated with reduced connectivity. We conclude that the existing MPA network is vulnerable to atmospheric-driven changes in ocean circulation.

  20. Formation and electrical characteristics of silicon dioxide layers by use of nitric acid oxidation method

    International Nuclear Information System (INIS)

    Imal, S.; Takahashi, M.; Matsuba, K.; Asuha; Ishikawa, Y.; Kobayashi, Hikaru

    2005-01-01

    SiO 2 /Si structure can be formed at low temperatures by use of nitric acid (HNO 3 ) oxidation of Si (NAOS) method. When Si wafers are immersed in ∼ 40 wt% HNO 3 solutions at 108 deg C, ∼ 1 nm SiO 2 layers are formed. The subsequent immersion in 68 wt% HNO 3 (i.e., azeotropic mixture of HNO 3 with water) at 121 deg C increases the SiO 2 thickness. The 3,5 nm-thick SiO 2 layers produced by this two-step NAOS method possess a considerably low leakage current density (e.g. 1 x 10 2 A/cmi 2 at the forward gate bias, V G , of 1.5 V), in spite of the low temperature oxidation, and further decreased (e.g., 8 x 10 4 A/cm 2 at V G = 1.5 V) by post-metallization annealing at 250 deg C in hydrogen atmosphere. In order to increase the SiO 2 thickness, a bias voltage is applied during the NAOS method. When 10 V is applied to Si with respect to a Pt counter electrode both immersed in 1 M HNO 3 solutions at 25 deg C, SiO 2 layers with 8 nm thickness can be formed for 1 h(Authors)

  1. Spatiotemporal patterns of precipitation extremes in the Poyang Lake basin, China: Changing properties and causes

    Science.gov (United States)

    Xiao, M.

    2016-12-01

    Under the background of climate change, extensive attentions have been paid on the increased extreme precipitation from the public and government. To analyze the influences of large-scale climate indices on the precipitation extremes, the spatiotemporal patterns of precipitation extremes in the Poyang Lake basin have been investigated using the Bayesian hierarchical method. The seasonal maximum one-day precipitation amount (Rx1day) was used to represent the seasonal precipitation extremes. Results indicated that spring Rx1day was affected by El Niño/Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), a positive ENSO event in the same year tends to decrease the spring Rx1day in the northern part of Poyang Lake Basin while increase the spring Rx1day in southeastern Poyang Lake Basin, a positive NAO events in the same year tends to increase the spring Rx1day in the southwest and northwest part of Poyang Lake basin while decrease the spring Rx1day in the eastern part of Poyang Lake basin; summer Rx1day was affected by Indian Ocean Dipole (IOD), positive IOD events in the same year tend to increase the summer Rx1day of northern Poyang Lake basin while decrease summer Rx1day of southern Poyang Lake basin; autumn Rx1day was affected by ENSO, positive ENSO events in the same year tend to mainly increase the autumn Rx1day in the west part of Poyang Lake basin; winter Rx1day was mainly affected by the NAO, positive NAO events in the same year tend to mainly increase the winter Rx1day of southern Poyang Lake basin, while positive NAO events in the previous year tend to mainly increase the winter Rx1day in the central and northeast part of Poyang Lake basin. It is considered that the region with the negative vertical velocity is dominated by more precipitation and vice versa. Furthermore, field patterns of 500 hPa vertical velocity anomalies related to each climate index have further corroborated the influences of climate indices on the seasonal Rx1day, and

  2. Influence of North Atlantic modes on European climate extremes

    Science.gov (United States)

    Proemmel, K.; Cubasch, U.

    2017-12-01

    It is well known that the North Atlantic strongly influences European climate. Only few studies exist that focus on its impact on climate extremes. We are interested in these extremes and the processes and mechanisms behind it. For the analysis of the North Atlantic Oscillation (NAO) we use simulations performed with the Max Planck Institute for Meteorology Earth System Model (MPI-ESM). The NAO has a strong impact especially on European winter and the changes in minimum temperature are even larger than in maximum temperature. The impact of the Atlantic Multi-decadal Variability (AMV) on climate extremes is analyzed in ECHAM6 simulations forced with AMV warm and AMV cold sea surface temperature patterns. We analyze different extreme indices and try to understand the processes.

  3. Feasibility of using a humanoid robot to elicit communicational response in children with mild autism

    Science.gov (United States)

    Malik, Norjasween Abdul; Shamsuddin, Syamimi; Yussof, Hanafiah; Azfar Miskam, Mohd; Che Hamid, Aminullah

    2013-12-01

    Research evidences are accumulating with regards to the potential use of robots for the rehabilitation of children with autism. The purpose of this paper is to elaborate on the results of communicational response in two children with autism during interaction with the humanoid robot NAO. Both autistic subjects in this study have been diagnosed with mild autism. Following the outcome from our first pilot study; the aim of this current experiment is to explore the application of NAO robot to engage with a child and further teach about emotions through a game-centered and song-based approach. The experiment procedure involved interaction between humanoid robot NAO with each child through a series of four different modules. The observation items are based on ten items selected and referenced to GARS-2 (Gilliam Autism Rating Scale-second edition) and also input from clinicians and therapists. The results clearly indicated that both of the children showed optimistic response through the interaction. Negative responses such as feeling scared or shying away from the robot were not detected. Two-way communication between the child and robot in real time significantly gives positive impact in the responses towards the robot. To conclude, it is feasible to include robot-based interaction specifically to elicit communicational response as a part of the rehabilitation intervention of children with autism.

  4. Interannual abundance changes of gelatinous carnivore zooplankton unveil climate-driven hydrographic variations in the Iberian Peninsula, Portugal.

    Science.gov (United States)

    D'Ambrosio, Mariaelena; Molinero, Juan C; Azeiteiro, Ulisses M; Pardal, Miguel A; Primo, Ana L; Nyitrai, Daniel; Marques, Sónia C

    2016-09-01

    The persistent massive blooms of gelatinous zooplankton recorded during recent decades may be indicative of marine ecosystem changes. In this study, we investigated the potential influence of the North Atlantic climate (NAO) variability on decadal abundance changes of gelatinous carnivore zooplankton in the Mondego estuary, Portugal, over the period 2003-2013. During the 11-year study, the community of gelatinous carnivores encompassed a larger diversity of hydromedusae than siphonophores; the former dominated by Obelia spp., Lizzia blondina, Clythia hemisphaerica, Liriope tetraphylla and Solmaris corona, while the latter dominated by Muggiaea atlantica. Gelatinous carnivore zooplankton displayed marked interannual variability and mounting species richness over the period examined. Their pattern of abundance shifted towards larger abundances ca. 2007 and significant phenological changes. The latter included a shift in the mean annual pattern (from unimodal to bimodal peak, prior and after 2007 respectively) and an earlier timing of the first annual peak concurrent with enhanced temperatures. These changes were concurrent with the climate-driven environmental variability mainly controlled by the NAO, which displayed larger variance after 2007 along with an enhanced upwelling activity. Structural equation modelling allowed depicting cascading effects derived from the NAO influence on regional climate and upwelling variability further shaping water temperature. Such cascading effect percolated the structure and dynamics of the community of gelatinous carnivore zooplankton in the Mondego estuary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Forcing of the wintertime atmospheric circulation by the multidecadal fluctuations of the North Atlantic ocean

    International Nuclear Information System (INIS)

    Peings, Yannick; Magnusdottir, Gudrun

    2014-01-01

    The North Atlantic sea surface temperature exhibits fluctuations on the multidecadal time scale, a phenomenon known as the Atlantic Multidecadal Oscillation (AMO). This letter demonstrates that the multidecadal fluctuations of the wintertime North Atlantic Oscillation (NAO) are tied to the AMO, with an opposite-signed relationship between the polarities of the AMO and the NAO. Our statistical analyses suggest that the AMO signal precedes the NAO by 10–15 years with an interesting predictability window for decadal forecasting. The AMO footprint is also detected in the multidecadal variability of the intraseasonal weather regimes of the North Atlantic sector. This observational evidence is robust over the entire 20th century and it is supported by numerical experiments with an atmospheric global climate model. The simulations suggest that the AMO-related SST anomalies induce the atmospheric anomalies by shifting the atmospheric baroclinic zone over the North Atlantic basin. As in observations, the positive phase of the AMO results in more frequent negative NAO—and blocking episodes in winter that promote the occurrence of cold extreme temperatures over the eastern United States and Europe. Thus, it is plausible that the AMO plays a role in the recent resurgence of severe winter weather in these regions and that wintertime cold extremes will be promoted as long as the AMO remains positive. (paper)

  6. High-Energy-Density Metal-Oxygen Batteries: Lithium-Oxygen Batteries vs Sodium-Oxygen Batteries.

    Science.gov (United States)

    Song, Kyeongse; Agyeman, Daniel Adjei; Park, Mihui; Yang, Junghoon; Kang, Yong-Mook

    2017-12-01

    The development of next-generation energy-storage devices with high power, high energy density, and safety is critical for the success of large-scale energy-storage systems (ESSs), such as electric vehicles. Rechargeable sodium-oxygen (Na-O 2 ) batteries offer a new and promising opportunity for low-cost, high-energy-density, and relatively efficient electrochemical systems. Although the specific energy density of the Na-O 2 battery is lower than that of the lithium-oxygen (Li-O 2 ) battery, the abundance and low cost of sodium resources offer major advantages for its practical application in the near future. However, little has so far been reported regarding the cell chemistry, to explain the rate-limiting parameters and the corresponding low round-trip efficiency and cycle degradation. Consequently, an elucidation of the reaction mechanism is needed for both lithium-oxygen and sodium-oxygen cells. An in-depth understanding of the differences and similarities between Li-O 2 and Na-O 2 battery systems, in terms of thermodynamics and a structural viewpoint, will be meaningful to promote the development of advanced metal-oxygen batteries. State-of-the-art battery design principles for high-energy-density lithium-oxygen and sodium-oxygen batteries are thus reviewed in depth here. Major drawbacks, reaction mechanisms, and recent strategies to improve performance are also summarized. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. The influence of the North Atlantic Ocean variability on the atmosphere in the cold season at seasonal to multidecadal time scales

    Science.gov (United States)

    Frankignoul, C.

    2017-12-01

    Observational evidence of an atmospheric response to the North Atlantic horseshoe SST anomalies has been accumulating since the late 90's, suggesting that it drives a negative NAO response during late fall/early winter. The North Atlantic horseshoe SST anomaly is in part stochastically driven by the atmosphere, but at low frequency it is correlated with the Atlantic Multidecadal Oscillation (AMO). Correspondingly, an atmospheric response to the AMO has been detected at low frequency in winter, with a positive AMO phase leading a negative NAO-like pattern, consistent with sensitivity studies with atmospheric general circulation models. Both the subpolar and tropical components of the AMO seem to contribute to its influence on the atmosphere. As North Atlantic SST changes reflects internally-generated SST fluctuations as well the response to anthropogenic and other external forcing, the AMO is sensitive to the way the forced SST signal is removed; estimates of the natural variability of the AMO vary by as much as a factor of two between estimation methods, leading to possible biases in its alleged impacts. Since an intensification of the Atlantic meridional overturning circulation (AMOC) leads the AMO and drives a negative NAO in many climate models, albeit with different lead times, the relation between AMO and AMOC will be discussed, as well as possible links with the North Pacific and sea ice variability.

  8. Interannual Variability of Northern Hemisphere Storm Tracks in Coarse-Gridded Datasets

    Directory of Open Access Journals (Sweden)

    Timothy Paul Eichler

    2013-01-01

    Full Text Available Extratropical cyclones exert a large socioeconomic impact. It is therefore important to assess their interannual variability. We generate cyclone tracks from the National Center for Environmental Prediction’s Reanalysis I and the European Centre for Medium Range Prediction ERA-40 reanalysis datasets. To investigate the interannual variability of cyclone tracks, we compare the effects of El Niño, the North Atlantic Oscillation (NAO, the Indian Ocean Dipole (IOD, and the Pacific North American Pattern (PNA on cyclone tracks. Composite analysis shows similar results for the impacts of El Niño, NAO, and the PNA on NH storm tracks. Although it is encouraging, we also found regional differences when comparing reanalysis datasets. The results for the IOD suggested a wave-like alteration of cyclone frequency across the northern US/Canada possibly related to Rossby wave propagation. Partial correlation demonstrates that although El Niño affects cyclone frequency in the North Pacific and along the US east coast, its impact on the North Pacific is accomplished via the PNA. Similarly, the PNA’s impact on US east coast storms is modulated via El Niño. In contrast, the impacts of the NAO extend as far west as the North Pacific and are not influenced by either the PNA or El Niño.

  9. Sea Surface Temperature Records Using Sr/Ca Ratios in a Siderastrea siderea Coral from SE Cuba

    Science.gov (United States)

    Fargher, H. A.; Hughen, K. A.; Ossolinski, J. E.; Bretos, F.; Siciliano, D.; Gonzalez, P.

    2015-12-01

    Sea surface temperature (SST) variability from Cuba remains relatively unknown compared to the rest of the Caribbean. Cuba sits near an inflection point in the spatial pattern of SST from the North Atlantic Oscillation (NAO), and long SST records from the region could reveal changes in the influence of this climate system through time. A Siderastrea siderea coral from the Jardínes de la Reina in southern Cuba was drilled to obtain a 220 year long archive of environmental change. The genus Siderastrea has not been extensively studied as an SST archive, yet Sr/Ca ratios in the Cuban core show a clear seasonal signal and strong correlation to instrumental SST data (r2 = 0.86 and 0.36 for monthly and interannual (winter season) timescales, respectively). Annual growth rates (linear extension) of the coral are observed to have a minor influence on Sr/Ca variability, but do not show a direct correlation to SST on timescales from annual to multidecadal. Sr/Ca measurements from the Cuban coral are used to reconstruct monthly and seasonal (winter, summer) SST extending back more than two centuries. Wintertime SST in southern Cuba is compared to other coral Sr/Ca records of winter-season SST from locations sensitive to the NAO in order to investigate the stationarity of the NAO SST 'fingerprint' through time.

  10. Densification of ∼5 nm-thick SiO_2 layers by nitric acid oxidation

    International Nuclear Information System (INIS)

    Choi, Jaeyoung; Joo, Soyeong; Park, Tae Joo; Kim, Woo-Byoung

    2017-01-01

    Highlights: • Leakage current density of the commercial PECVD grown ∼5 nm SiO_2 layer has been decreased about three orders of magnitude by densification. • The densification of SiO_2 layer is achieved by high oxidation ability of O·. • Densities of suboxide, fixed charge (N_f) and defect state (N_d) in SiO_2/Si interface are decreased by NAOS and PMA. • Tunneling barrier height (Φ_t) is increased because of the increase of atomic density in SiO_2 layer. - Abstract: Low-temperature nitric acid (HNO_3) oxidation of Si (NAOS) has been used to improve the interface and electrical properties of ∼5 nm-thick SiO_2/Si layers produced by plasma-enhanced chemical vapor deposition (PECVD). Investigations of the physical properties and electrical characteristics of these thin films revealed that although their thickness is not changed by NAOS, the leakage current density at a gate bias voltage of −1 V decreases by about two orders of magnitude from 1.868 × 10"−"5 A/cm"2. This leakage current density was further reduced by post-metallization annealing (PMA) at 250 °C for 10 min in a 5 vol.% hydrogen atmosphere, eventually reaching a level (5.2 × 10"−"8 A/cm"2) approximately three orders of magnitude less than the as-grown SiO_2 layer. This improvement is attributed to a decrease in the concentration of suboxide species (Si"1"+, Si"2"+ and Si"3"+) in the SiO_2/Si interface, as well as a decrease in the equilibrium density of defect sites (N_d) and fixed charge density (N_f). The barrier height (Φ_t) generated by a Poole-Frenkel mechanism also increased from 0.205 to 0.371 eV after NAOS and PMA. The decrease in leakage current density is therefore attributed to a densification of the SiO_2 layer in combination with the removal of OH species and increase in interfacial properties at the SiO_2/Si interface.

  11. A switch in the Atlantic Oscillation correlates with inter-annual changes in foraging location and food habits of Macaronesian shearwaters (Puffinus baroli) nesting on two islands of the sub-tropical Atlantic Ocean

    Science.gov (United States)

    Ramos, Jaime A.; Isabel Fagundes, Ana; Xavier, José C.; Fidalgo, Vera; Ceia, Filipe R.; Medeiros, Renata; Paiva, Vitor H.

    2015-10-01

    Changes in oceanographic conditions, shaped by changes in large-scale atmospheric phenomena such as the North Atlantic Oscillation (NAO), alters the structure and functioning of marine ecosystems. Such signals are readily captured by marine top predators, given that their use of foraging habitats and diets change when the NAO changes. In this study we assessed sexual, seasonal and annual (2010/11-2012/13) differences in diet, trophic and isotopic niche (using δ15N and δ13C values of whole blood, 1st primary, 8th secondary and breast feathers), foraging locations and oceanographic variation within foraging areas for Macaronesian shearwaters' (Puffinus baroli) during two years of contrasting NAO values, and between two sub-tropical islands 330 km apart in the North Atlantic Ocean, Cima Islet and Selvagem Grande. These two locations provide contrasting oceanographic foraging regimes for the birds, because the second colony is much closer to the African coast (375 vs 650 km), and, therefore, to the upwelling area of the Canary Current. There was a marked environmental perturbation in 2010/2011, related with a negative NAO Index and lower marine productivity (lower concentration of Chlorophyll a). This event corresponded to the Macaronesian shearwaters feeding farther north and west, which was readily seen in change of both δ15N and δ13C values, and in a higher intake of cephalopods. Diet and stable isotopes did not differ between sexes. Regurgitation analysis indicate a dominance of cephalopods in both islands, but prey fish were important for Selvagem Grande in 2012 and cephalopods for Cima Islet in 2011. Both δ15N and δ13C values were significantly higher for Cima Islet than for Selvagem Grande, irrespective of year, season and tissue sampled. SIBER analysis showed smaller isotopic niches for the breeding period. Our study suggests that during years of poor environmental conditions Macaronesian shearwaters shift their foraging location to more pelagic waters

  12. DOI: 10.4025/actascibiolsci.v33i3.8011 Acta Scientiarum. Biological Sciences Maringá, v. 33, n. 3, p. 239-246, 2011 Acute inflammatory response in Nile tilapia fed probiotic Lactobacillus plantarum in the diet = Resposta inflamatória aguda em tilápia do Nilo alimentada com probiótico, Lactobacillus plantarum na dieta

    Directory of Open Access Journals (Sweden)

    Geovana Dotta

    2011-07-01

    Full Text Available The present study evaluated the acute inflammatory response induced bycarrageenin (500 £gg injected in the swim bladder of Nile tilapia, after fed or not probiotic supplemented diet. Fifty four fish were distributed in six treatments and three replicates: Group A: Fish fed unsupplemented diet: 0.5 mL saline-injected fish; fish injected with 500 £gg carrageenin diluted in 0.5 mL saline; Non-injected. Group B: Fish fed probiotic supplemented diet: saline-injected fish; carrageenin-injected fish; Non-injected. Fifteen days after feeding the fish were injected with carrageenin or saline. After six hours, inflammatory exudate was collected, as well as the blood for hematocrit, red blood cell (RBC and white blood cell (WBC counts, differential count of leucocytes and phagocytic activity in the blood. Supplementation with probiotic did not influence the RBC, hematocrit and the numbers of lymphocytes and basophils in the blood. The number of neutrophils was significantly higher in supplemented fish injected with carrageenin. Glucose concentration in supplemented and non-injected fish was higher than that observed in the saline injected ones. Probiotic potentialized the migration of cells to the inflammatory focus in the animals injected with the carrageenin irritant. In fish injected with saline and carrageenin occurred the greatest phagocytic activity in the blood in relation to those treatments.Este trabalho avaliou a resposta inflamatoria aguda induzida por injecao de carragenina (500 ƒÝg na bexiga natatoria de tilapia do Nilo suplementada ou nao com probiotico na racao. Cinquenta e quatro animais foram distribuidos em seis tratamentos com tres repeticoes: Grupo A: peixes alimentados com racao naosuplementada: Controle (injecao de 0,5 mL de solucao salina esteril; Carragenina (injecao de500 £gg de carragenina; Nao-injetada. Grupo B: peixes alimentados com racao suplementada com probiotico: Controle; Carragenina; Nao-injetada. Apos 15 dias de

  13. Local temperature fine-tunes the timing of spring migration in birds

    DEFF Research Database (Denmark)

    Tøttrup, Anders P.; Rainio, Kalle; Coppack, Timothy

    2010-01-01

    and predict consequences of climatic change for migratory birds. In order to better understand migration phenology and adaptation in environmental changes, we here assess the scale at which weather affects timing of spring migration in passerine birds. We use three commonly used proxies of spring......-time climatic conditions: (1) vegetation "greenness" (NDVI) in Europe, (2) local spring temperatures in northern Europe, and (3) the North Atlantic Oscillation Index (NAO) as predictors of the phenology of avian migration as well as the strength of their effect on different subsets of populations...... breeding area. Local temperature was the best single predictor of phenology with the highest explanatory power achieved in combination with NAO. Furthermore, early individuals are more affected by climatic variation compared to individuals on later passage, indicating that climatic change affects subsets...

  14. The Study of Fractional Order Controller with SLAM in the Humanoid Robot

    Directory of Open Access Journals (Sweden)

    Shuhuan Wen

    2014-01-01

    Full Text Available We present a fractional order PI controller (FOPI with SLAM method, and the proposed method is used in the simulation of navigation of NAO humanoid robot from Aldebaran. We can discretize the transfer function by the Al-Alaoui generating function and then get the FOPI controller by Power Series Expansion (PSE. FOPI can be used as a correction part to reduce the accumulated error of SLAM. In the FOPI controller, the parameters (Kp,Ki,  and  α need to be tuned to obtain the best performance. Finally, we compare the results of position without controller and with PI controller, FOPI controller. The simulations show that the FOPI controller can reduce the error between the real position and estimated position. The proposed method is efficient and reliable for NAO navigation.

  15. Neli jaapani mängufilmi / Lauri Kitsnik

    Index Scriptorium Estoniae

    Kitsnik, Lauri

    2008-01-01

    Jaapani filmidest: "Elagu filmitegija!" ("Kantoku banzai") rezh. Takeshi Kitano (2007); "Sukiyaki Western Django" rezh. Takashi Miike (2007); "Hana" ("Hana yori mo nao)" rezh. Kore-eda Hirokazu (2006); "Leinav mets" ("Mogari no mori") rezh. Kawase Naomi (2007)

  16. Astronomical databases of Nikolaev Observatory

    Science.gov (United States)

    Protsyuk, Y.; Mazhaev, A.

    2008-07-01

    Several astronomical databases were created at Nikolaev Observatory during the last years. The databases are built by using MySQL search engine and PHP scripts. They are available on NAO web-site http://www.mao.nikolaev.ua.

  17. The North Atlantic Oscillation system and plant phenology

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk

    2016-01-01

    Roč. 60, č. 5 (2016), s. 749-756 ISSN 0020-7128 Institutional support: RVO:68081766 Keywords : NAO * atmospheric circulation * weather * temperature * flowering timing * Czech Republic Subject RIV: EH - Ecology, Behaviour Impact factor: 2.204, year: 2016

  18. Effect of Zhen Nao Capsules on Consolidated Disturbance of Memory Induced by NaNO2 in Mice%珍脑胶囊对NaNO2所致记忆巩固障碍小鼠学习记忆能力的影响

    Institute of Scientific and Technical Information of China (English)

    陈艳萍

    2009-01-01

    Objective To investigate the effects of Zhen Nao Capsules(ZN) on consolidated disturbance of memory in mice. Methods The memory deficits mice were induced by hypodermic injection of sodium nitrite(120mg·kg-1).Foraging maze and step-down tests were performed to evaluate the learning and memory of the deficits mice.Results ZN(2 000mg·kg-1 and 1 000 mg·kg-1) remarkably reduced the number of trials in labyrinth test and reduced the mistake times of step-down and prolonged step down latency in step-down tests. Conclusion It showed that ZN had a better improvement function on learning and memory in memory deficits mice.%目的 观察珍脑胶囊对亚硝酸钠(NaNO2)所致记忆巩固障碍小鼠学习记忆能力的影响.方法 采用皮下注射NaNO2制造记忆巩固障碍模型,通过迷宫试验和跳台试验,观察药物时模型小鼠学习记忆能力的影响.结果 珍脑胶囊可缩短迷宫试验中记忆巩固障碍小鼠的觅食时间;能够延长跳台试验中记忆巩固障碍小鼠的触电潜伏期,减少小鼠的错误次数.高、中剂量效果较好.结论 珍脑胶囊有改善学习记忆能力作用.

  19. «Approchez avec crainte de Dieu, foi et amour» : le programme iconographique de la travée occidentale de l’abside en Moldavie (XVe – XVIe siècles

    Directory of Open Access Journals (Sweden)

    Vlad Bedros

    2015-12-01

    Full Text Available This paper, informed by an inventory of the apse iconography in Moldavian monuments from the late 15th to the first half of the 16th century, draws attention to an overlooked element of the otherwise familiar iconographic system employed – with occasional nuances – within the Post-Byzantine tradition in the aftermath of the Alosis: the selection of themes to be displayed in the bay which links the apse to the naos. The arrangements encountered in monuments dating from (approx. 1490 to 1535 put forward a variety of formulas which – although described in a sequence that deliberately emphasizes the similarities which came across – are nonetheless indicative of a broad and not necessarily fluent use of the late Byzantine tradition. It seems that the basic message conveyed by these iconographic boundaries aims at stressing the holiness of the sanctuary (involving a separation from the iconography of the naos, in the cases of Probota and Saint-Georges in Suceava but also, in a manner which could be informed by the late Byzantine perception of the liturgy – as deduced from the writings of Nicolas Cabasilas and St. Simeon of Thessaloniki –, at joining together naos and apse, via ‘iconographic belts’ (most frequently the Passion cycle, which sets out from and ends up in the sanctuary. The abundance of theophanic themes invites one to consider this iconographic thresholds in relation with the receiving of Communion, administered on the solea which lies underneath.

  20. Cold-season atmospheric response to the natural variability of the Atlantic meridional overturning circulation

    Energy Technology Data Exchange (ETDEWEB)

    Gastineau, Guillaume; Frankignoul, Claude [LOCEAN/IPSL, Universite Pierre et Marie Curie, 4 place Jussieu, BP100, Paris Cedex 05 (France)

    2012-07-15

    The influence of the natural variability of the Atlantic meridional overturning circulation (AMOC) on the atmosphere is studied in multi-centennial simulations of six global climate models, using Maximum Covariance Analysis (MCA). In all models, a significant but weak influence of the AMOC changes is found during the Northern Hemisphere cold-season, when the ocean leads the atmosphere by a few years. Although the oceanic pattern slightly varies, an intensification of the AMOC is followed in all models by a weak sea level pressure response that resembles a negative phase of the North Atlantic Oscillation (NAO). The signal amplitude is typically 0.5 hPa and explains about 10% of the yearly variability of the NAO in all models. The atmospheric response seems to be due primarily due to an increase of the heat loss along the North Atlantic Current and the subpolar gyre, associated with an AMOC-driven warming. Sea-ice changes appear to be less important. The stronger heating is associated to a southward shift of the lower-tropospheric baroclinicity and a decrease of the eddy activity in the North Atlantic storm track, which is consistent with the equivalent barotropic perturbation resembling the negative phase of the NAO. This study thus provides some evidence of an atmospheric signature of the AMOC in the cold-season, which may have some implications for the decadal predictability of climate in the North Atlantic region. (orig.)

  1. Humanoid assessing rehabilitative exercises.

    Science.gov (United States)

    Simonov, M; Delconte, G

    2015-01-01

    This article is part of the Focus Theme of Methods of Information in Medicine on "New Methodologies for Patients Rehabilitation". The article presents the approach in which the rehabilitative exercise prepared by healthcare professional is encoded as formal knowledge and used by humanoid robot to assist patients without involving other care actors. The main objective is the use of humanoids in rehabilitative care. An example is pulmonary rehabilitation in COPD patients. Another goal is the automated judgment functionality to determine how the rehabilitation exercise matches the pre-programmed correct sequence. We use the Aldebaran Robotics' NAO humanoid to set up artificial cognitive application. Pre-programmed NAO induces elderly patient to undertake humanoid-driven rehabilitation exercise, but needs to evaluate the human actions against the correct template. Patient is observed using NAO's eyes. We use the Microsoft Kinect SDK to extract motion path from the humanoid's recorded video. We compare human- and humanoid-operated process sequences by using the Dynamic Time Warping (DTW) and test the prototype. This artificial cognitive software showcases the use of DTW algorithm to enable humanoids to judge in near real-time about the correctness of rehabilitative exercises performed by patients following the robot's indications. One could enable better sustainable rehabilitative care services in remote residential settings by combining intelligent applications piloting humanoids with the DTW pattern matching algorithm applied at run time to compare humanoid- and human-operated process sequences. In turn, it will lower the need of human care.

  2. Por uma sócio-musicologia ancorada na semiologia da enunciação: uma alternativa para o estudo do acontecimento musical urbano na presente modernidade

    Directory of Open Access Journals (Sweden)

    Regina Marcia Simão Santos

    1998-08-01

    Full Text Available O objetivo deste artigo é apontar para uma sócio-semiologia em música, na vertente dos estudos de enunciação e analise dos discursos, em resposta a lacunas detectadas nas pesquisas musicológicas. Traz contribuições para a atualização do debate sobre comunicação, ao considerar o funcionamento enunciativo em cada situaçnao concreta de performance, constituído de cena social e cena enunciativa, com dispositivos contextuais e intertextuais postos em jogo na produção e na recepção, gerando sentidos. Conclui pela bénefica adoaçnao deste enfoque metodológico no estudo do acontecimento musical urbano, superando os limites de uma analise estrutural, com seus recortes teóricos, por outra que considere sentidos inscritos no social.

  3. [Achievements and enlightenment of modern acupuncture therapy for stroke based on the neuroanatomy].

    Science.gov (United States)

    Chen, Li-Fang; Fang, Jian-Qiao; Chen, Lu-Ni; Wang, Chao

    2014-04-01

    Up to now, in the treatment of stroke patients by acupuncture therapy, three main representative achievements involving scalp acupuncture intervention, "Xing Nao Kai Qiao" (restoring consciousness and inducing resuscitation) acupuncture technique and nape acupuncture therapy have been got. Regarding their neurobiological mechanisms, the scalp acupuncture therapy is based on the functional localization of the cerebral cortex, "Xing Nao Kai Qiao" acupuncture therapy is closely related to nerve stem stimulation, and the nape acupuncture therapy is based on the nerve innervation of the regional neck-nape area in obtaining therapeutic effects. In fact, effects of these three acupuncture interventions are all closely associated with the modern neuroanatomy. In the treatment of post-stroke spastic paralysis, cognitive disorder and depression with acupuncture therapy, modern neuroanatomical knowledge should be one of the key theoretical basis and new therapeutic techniques should be explored and developed continuously.

  4. Innovative UK Approaches to Acquisition Management

    Science.gov (United States)

    2009-05-01

    Financial and Operational Imperatives Size of UK armed forces UK Industry ? Political influence PFI / PPP Increased Scrutiny - NAO “ Commercialisation “ of the...acquisition KNOWLEDGE (EXPERIENCE – Lessons learned) KNOWLEDGE (Training) KNOWLEDGE ( Education ) OPTIMAL OPERATIONAL PERFORMANCE Operational Capability UK

  5. Spatial monsoon variability with respect to NAO and SO

    Indian Academy of Sciences (India)

    the negative phase of ESI tendency, almost all subdivisions of India show ... to affect the Indian summer monsoon rainfall indi- ... Monthly composite picture of ESI during (a) positive (28 years) and (b) negative (25 years) tendency of ESI.

  6. The seasonal predictability of blocking frequency in two seasonal prediction systems (CMCC, Met-Office) and the associated representation of low-frequency variability.

    Science.gov (United States)

    Athanasiadis, Panos; Gualdi, Silvio; Scaife, Adam A.; Bellucci, Alessio; Hermanson, Leon; MacLachlan, Craig; Arribas, Alberto; Materia, Stefano; Borelli, Andrea

    2014-05-01

    Low-frequency variability is a fundamental component of the atmospheric circulation. Extratropical teleconnections, the occurrence of blocking and the slow modulation of the jet streams and storm tracks are all different aspects of low-frequency variability. Part of the latter is attributed to the chaotic nature of the atmosphere and is inherently unpredictable. On the other hand, primarily as a response to boundary forcings, tropospheric low-frequency variability includes components that are potentially predictable. Seasonal forecasting faces the difficult task of predicting these components. Particularly referring to the extratropics, the current generation of seasonal forecasting systems seem to be approaching this target by realistically initializing most components of the climate system, using higher resolution and utilizing large ensemble sizes. Two seasonal prediction systems (Met-Office GloSea and CMCC-SPS-v1.5) are analyzed in terms of their representation of different aspects of extratropical low-frequency variability. The current operational Met-Office system achieves unprecedented high scores in predicting the winter-mean phase of the North Atlantic Oscillation (NAO, corr. 0.74 at 500 hPa) and the Pacific-N. American pattern (PNA, corr. 0.82). The CMCC system, considering its small ensemble size and course resolution, also achieves good scores (0.42 for NAO, 0.51 for PNA). Despite these positive features, both models suffer from biases in low-frequency variance, particularly in the N. Atlantic. Consequently, it is found that their intrinsic variability patterns (sectoral EOFs) differ significantly from the observed, and the known teleconnections are underrepresented. Regarding the representation of N. hemisphere blocking, after bias correction both systems exhibit a realistic climatology of blocking frequency. In this assessment, instantaneous blocking and large-scale persistent blocking events are identified using daily geopotential height fields at

  7. Sliding mode observers for automotive alternator

    Science.gov (United States)

    Chen, De-Shiou

    Estimator development for synchronous rectification of the automotive alternator is a desirable approach for estimating alternator's back electromotive forces (EMFs) without a direct mechanical sensor of the rotor position. Recent theoretical studies show that estimation of the back EMF may be observed based on system's phase current model by sensing electrical variables (AC phase currents and DC bus voltage) of the synchronous rectifier. Observer design of the back EMF estimation has been developed for constant engine speed. In this work, we are interested in nonlinear observer design of the back EMF estimation for the real case of variable engine speed. Initial back EMF estimate can be obtained from a first-order sliding mode observer (SMO) based on the phase current model. A fourth-order nonlinear asymptotic observer (NAO), complemented by the dynamics of the back EMF with time-varying frequency and amplitude, is then incorporated into the observer design for chattering reduction. Since the cost of required phase current sensors may be prohibitive, the most applicable approach in real implementation by measuring DC current of the synchronous rectifier is carried out in the dissertation. It is shown that the DC link current consists of sequential "windows" with partial information of the phase currents, hence, the cascaded NAO is responsible not only for the purpose of chattering reduction but also for necessarily accomplishing the process of estimation. Stability analyses of the proposed estimators are considered for most linear and time-varying cases. The stability of the NAO without speed information is substantiated by both numerical and experimental results. Prospective estimation algorithms for the case of battery current measurements are investigated. Theoretical study indicates that the convergence of the proposed LAO may be provided by high gain inputs. Since the order of the LAO/NAO for the battery current case is one order higher than that of the link

  8. Densification of ∼5 nm-thick SiO{sub 2} layers by nitric acid oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jaeyoung [Department of Energy Engineering, Dankook University, Cheonan 311-16 (Korea, Republic of); Joo, Soyeong [Institute for Advanced Engineering (IAE), Advanced Materials & Processing Center, Youngin 449-863 (Korea, Republic of); Park, Tae Joo [Department of Materials Science and Chemical Engineering, Hanyang University, Ansan 15588 (Korea, Republic of); Kim, Woo-Byoung, E-mail: woo7838@dankook.ac.kr [Department of Energy Engineering, Dankook University, Cheonan 311-16 (Korea, Republic of)

    2017-08-15

    Highlights: • Leakage current density of the commercial PECVD grown ∼5 nm SiO{sub 2} layer has been decreased about three orders of magnitude by densification. • The densification of SiO{sub 2} layer is achieved by high oxidation ability of O·. • Densities of suboxide, fixed charge (N{sub f}) and defect state (N{sub d}) in SiO{sub 2}/Si interface are decreased by NAOS and PMA. • Tunneling barrier height (Φ{sub t}) is increased because of the increase of atomic density in SiO{sub 2} layer. - Abstract: Low-temperature nitric acid (HNO{sub 3}) oxidation of Si (NAOS) has been used to improve the interface and electrical properties of ∼5 nm-thick SiO{sub 2}/Si layers produced by plasma-enhanced chemical vapor deposition (PECVD). Investigations of the physical properties and electrical characteristics of these thin films revealed that although their thickness is not changed by NAOS, the leakage current density at a gate bias voltage of −1 V decreases by about two orders of magnitude from 1.868 × 10{sup −5} A/cm{sup 2}. This leakage current density was further reduced by post-metallization annealing (PMA) at 250 °C for 10 min in a 5 vol.% hydrogen atmosphere, eventually reaching a level (5.2 × 10{sup −8} A/cm{sup 2}) approximately three orders of magnitude less than the as-grown SiO{sub 2} layer. This improvement is attributed to a decrease in the concentration of suboxide species (Si{sup 1+}, Si{sup 2+} and Si{sup 3+}) in the SiO{sub 2}/Si interface, as well as a decrease in the equilibrium density of defect sites (N{sub d}) and fixed charge density (N{sub f}). The barrier height (Φ{sub t}) generated by a Poole-Frenkel mechanism also increased from 0.205 to 0.371 eV after NAOS and PMA. The decrease in leakage current density is therefore attributed to a densification of the SiO{sub 2} layer in combination with the removal of OH species and increase in interfacial properties at the SiO{sub 2}/Si interface.

  9. Investigation of hemorheological and analgesic properties of Qing ...

    African Journals Online (AJOL)

    Nao tablet (QNT). Methods: Sixty animals were divided into 6 groups (n = 10 for each group): normal, control, positive and 3 QNT-treated groups (QNT-H, QNT-M, QNT-L). Animals in normal and control groups received normal saline orally, while ...

  10. About Nano-JASMINE Satellite System and Project Status

    Science.gov (United States)

    Sako, Nobutada

    Intelligent Space Systems Laboratory, The University of Tokyo (ISSL) and National Astronomical Observatory of Japan (NAO) have been developing a small infrared astrometry satellite named “Nano-JASMINE”. The satellite size is about 50cm cubic and 20kg, which plays a pre-cursor role of JASMINE Project which is programmed by NAO and JAXA. In addition, since there has been only one astrometry satellite HIPPARCOS by ESA in the past, Nano-JASMINE is also expected to achieve certain scientific results in the field of astrometry. In this project, ISSL aims to develop new advanced small satellite bus system whose performance is comparable to that of 100-500kg sized satellites, including attitude stability of 1 arc-second and thermal stability of the mission subsystem of 1 mK. This paper overviews the Nano-JASMINE bus system with emphasis on attitude and thermal control systems.

  11. ECMWF Extreme Forecast Index for water vapor transport: A forecast tool for atmospheric rivers and extreme precipitation

    Science.gov (United States)

    Lavers, David A.; Pappenberger, Florian; Richardson, David S.; Zsoter, Ervin

    2016-11-01

    In winter, heavy precipitation and floods along the west coasts of midlatitude continents are largely caused by intense water vapor transport (integrated vapor transport (IVT)) within the atmospheric river of extratropical cyclones. This study builds on previous findings that showed that forecasts of IVT have higher predictability than precipitation, by applying and evaluating the European Centre for Medium-Range Weather Forecasts Extreme Forecast Index (EFI) for IVT in ensemble forecasts during three winters across Europe. We show that the IVT EFI is more able (than the precipitation EFI) to capture extreme precipitation in forecast week 2 during forecasts initialized in a positive North Atlantic Oscillation (NAO) phase; conversely, the precipitation EFI is better during the negative NAO phase and at shorter leads. An IVT EFI example for storm Desmond in December 2015 highlights its potential to identify upcoming hydrometeorological extremes, which may prove useful to the user and forecasting communities.

  12. Sensitivity of the Regional Climate in the Middle East and North Africa to Volcanic Perturbations

    KAUST Repository

    Dogar, Muhammad Mubashar; Stenchikov, Georgiy L.; Osipov, Sergey; Wyman, Bruce; Zhao, Ming

    2017-01-01

    The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/NCEP Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory's High-Resolution Atmospheric Model (HiRAM). A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.

  13. Changing response of the North Atlantic/European winter climate to the 11 year solar cycle

    Science.gov (United States)

    Ma, Hedi; Chen, Haishan; Gray, Lesley; Zhou, Liming; Li, Xing; Wang, Ruili; Zhu, Siguang

    2018-03-01

    Recent studies have presented conflicting results regarding the 11 year solar cycle (SC) influences on winter climate over the North Atlantic/European region. Analyses of only the most recent decades suggest a synchronized North Atlantic Oscillation (NAO)-like response pattern to the SC. Analyses of long-term climate data sets dating back to the late 19th century, however, suggest a mean sea level pressure (mslp) response that lags the SC by 2-4 years in the southern node of the NAO (i.e. Azores region). To understand the conflicting nature and cause of these time dependencies in the SC surface response, the present study employs a lead/lag multi-linear regression technique with a sliding window of 44 years over the period 1751-2016. Results confirm previous analyses, in which the average response for the whole time period features a statistically significant 2-4 year lagged mslp response centered over the Azores region. Overall, the lagged nature of Azores mslp response is generally consistent in time. Stronger and statistically significant SC signals tend to appear in the periods when the SC forcing amplitudes are relatively larger. Individual month analysis indicates the consistent lagged response in December-January-February average arises primarily from early winter months (i.e. December and January), which has been associated with ocean feedback processes that involve reinforcement by anomalies from the previous winter. Additional analysis suggests that the synchronous NAO-like response in recent decades arises primarily from late winter (February), possibly reflecting a result of strong internal noise.

  14. Sensitivity of the Regional Climate in the Middle East and North Africa to Volcanic Perturbations

    KAUST Repository

    Dogar, Muhammad Mubashar

    2017-07-27

    The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/NCEP Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory\\'s High-Resolution Atmospheric Model (HiRAM). A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.

  15. Factors affecting cone production in Pinus pinaster Ait.: lack of growth-reproduction trade-offs but significant effects of climate and tree and stand characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Bravo, F.; Maguire, D.A.; González-Martínez, S.G.

    2017-11-01

    Aim of study: Our main goal is to determine the relationship between cone production and radial growth in Pinus pinaster Ait. under different climatic conditions across the Iberian Peninsula. Area of study: Coca Intensive Sampling Plateau, Northern Plateau (Spain). Material and methods: Cone counts were conducted on an intensive monitoring plot in Coca (North-Central Spain) during the years 2000, 2006 and 2007. A ZIP (zero-inflated Poisson) model was adjusted for simultaneously estimating the probability of obtaining crop cones and its amount. The Northern Atlantic Oscillation (NAO) index was used as explanatory variable, together with a wide variety of tree and local stand variables. Climate (as evaluated by NAO), local stand density (here estimated from the six nearest trees), tree size and vigor, competition and growth efficiency significantly influenced both occurrence and intensity of cone production. Main results: ZIP models for predicting reproductive effort seems an adequate tool to predict reproductive responses to climatic fluctuations and the resulting future species distribution in the face of climate change, as well as to identify silviculture actions that would promote reproductive success in naturally-regenerated stands, list and discuss relevant results (including numeric values of experimental results). Research highlights: Climate, stand density and tree conditions (size and vigor, competition and growth efficiency) influence significantly both cone occurrence and intensity of fruiting as shown by a ZIP model. As the climate variables included in the model (based on Northern Atlantic Oscillation, NAO) are general and easily obtained, the proposed model has practical applicability to predicting Pinus pinaster cone production in the Iberian Peninsula.

  16. Atmosphere and ocean dynamics: contributors to the European Little Ice Age?

    Energy Technology Data Exchange (ETDEWEB)

    Palastanga, V.; Schrier, G. van der; Weber, S.L. [Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, De Bilt (Netherlands); Kleinen, T. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Max Planck Institute for Meteorology, Hamburg (Germany); Briffa, K.R.; Osborn, T.J. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom)

    2011-03-15

    The role of a reduction in the Atlantic meridional overturning and that of a persistently negative North Atlantic Oscillation in explaining the coldness of the European Little Ice Age (LIA) has been assessed in two sets of numerical experiments. These experiments are performed using an intermediate complexity climate model and a full complexity GCM. The reduction in the Meridional Overturning Circulation (MOC) of ca. 25% is triggered by a conventional fresh-water hosing set-up. A persistently negative NAO winter circulation, at NAO-index value -0.5, is imposed using recently developed data-assimilation techniques applicable on paleoclimatic timescales. The hosing experiments lead to a reduction in oceanic meridional heat transport and cooler sea-surface temperatures. Next to a direct cooling effect on European climate, the change in ocean surface temperatures feedback on the atmospheric circulation modifying European climate significantly. The data-assimilation experiments showed a reduction of winter temperatures over parts of Europe, but there is little persistence into the summer season. The output of all model experiments are compared to reconstructions of winter and summer temperature based on the available temperature data for the LIA period. This demonstrates that the hypothesis of a persistently negative NAO as an explanation for the European LIA does not hold. The hosing experiments do not clearly support the hypothesis that a reduction in the MOC is the primary driver of LIA climate change. However, a reduction in the Atlantic overturning might have been a cause of the European LIA climate, depending on whether there is a strong enough feedback on the atmospheric circulation. (orig.)

  17. Coupled Model Intercomparison Project 5 (CMIP5) simulations of climate following volcanic eruptions

    KAUST Repository

    Driscoll, Simon; Bozzo, Alessio; Gray, Lesley J.; Robock, Alan; Stenchikov, Georgiy L.

    2012-01-01

    The ability of the climate models submitted to the Coupled Model Intercomparison Project 5 (CMIP5) database to simulate the Northern Hemisphere winter climate following a large tropical volcanic eruption is assessed. When sulfate aerosols are produced by volcanic injections into the tropical stratosphere and spread by the stratospheric circulation, it not only causes globally averaged tropospheric cooling but also a localized heating in the lower stratosphere, which can cause major dynamical feedbacks. Observations show a lower stratospheric and surface response during the following one or two Northern Hemisphere (NH) winters, that resembles the positive phase of the North Atlantic Oscillation (NAO). Simulations from 13 CMIP5 models that represent tropical eruptions in the 19th and 20th century are examined, focusing on the large-scale regional impacts associated with the large-scale circulation during the NH winter season. The models generally fail to capture the NH dynamical response following eruptions. They do not sufficiently simulate the observed post-volcanic strengthened NH polar vortex, positive NAO, or NH Eurasian warming pattern, and they tend to overestimate the cooling in the tropical troposphere. The findings are confirmed by a superposed epoch analysis of the NAO index for each model. The study confirms previous similar evaluations and raises concern for the ability of current climate models to simulate the response of a major mode of global circulation variability to external forcings. This is also of concern for the accuracy of geoengineering modeling studies that assess the atmospheric response to stratosphere-injected particles.

  18. Factors affecting cone production in Pinus pinaster Ait.: lack of growth-reproduction trade-offs but significant effects of climate and tree and stand characteristics

    Directory of Open Access Journals (Sweden)

    Felipe Bravo

    2017-10-01

    Full Text Available Aim of study: Our main goal is to determine the relationship between cone production and radial growth in Pinus pinaster Ait. under different climatic conditions across the Iberian Peninsula. Area of study: Coca Intensive Sampling Plateau, Northern Plateau (Spain. Material and methods: Cone counts were conducted on an intensive monitoring plot in Coca (North-Central Spain during the years 2000, 2006 and 2007. A ZIP (zero-inflated Poisson model was adjusted for simultaneously estimating the probability of obtaining crop cones and its amount. The Northern Atlantic Oscillation (NAO index was used as explanatory variable, together with a wide variety of tree and local stand variables. Climate (as evaluated by NAO, local stand density (here estimated from the six nearest trees, tree size and vigor, competition and growth efficiency significantly influenced both occurrence and intensity of cone production. Main results: ZIP models for predicting reproductive effort seems an adequate tool to predict reproductive responses to climatic fluctuations and the resulting future species distribution in the face of climate change, as well as to identify silviculture actions that would promote reproductive success in naturally-regenerated stands, list and discuss relevant results (including numeric values of experimental results. Research highlights: Climate, stand density and tree conditions (size and vigor, competition and growth efficiency influence significantly both cone occurrence and intensity of fruiting as shown by a ZIP model. As the climate variables included in the model (based on Northern Atlantic Oscillation, NAO are general and easily obtained, the proposed model has practical applicability to predicting Pinus pinaster cone production in the Iberian Peninsula.

  19. Human motion characteristics in relation to feeling familiar or frightened during an announced short interaction with a proactive humanoid.

    Science.gov (United States)

    Baddoura, Ritta; Venture, Gentiane

    2014-01-01

    During an unannounced encounter between two humans and a proactive humanoid (NAO, Aldebaran Robotics), we study the dependencies between the human partners' affective experience (measured via the answers to a questionnaire) particularly regarding feeling familiar and feeling frightened, and their arm and head motion [frequency and smoothness using Inertial Measurement Units (IMU)]. NAO starts and ends its interaction with its partners by non-verbally greeting them hello (bowing) and goodbye (moving its arm). The robot is invested with a real and useful task to perform: handing each participant an envelope containing a questionnaire they need to answer. NAO's behavior varies from one partner to the other (Smooth with X vs. Resisting with Y). The results show high positive correlations between feeling familiar while interacting with the robot and: the frequency and smoothness of the human arm movement when waving back goodbye, as well as the smoothness of the head during the whole encounter. Results also show a negative dependency between feeling frightened and the frequency of the human arm movement when waving back goodbye. The principal component analysis (PCA) suggests that, in regards to the various motion measures examined in this paper, the head smoothness and the goodbye gesture frequency are the most reliable measures when it comes to considering the familiar experienced by the participants. The PCA also points out the irrelevance of the goodbye motion frequency when investigating the participants' experience of fear in its relation to their motion characteristics. The results are discussed in light of the major findings of studies on body movements and postures accompanying specific emotions.

  20. Factors affecting cone production in Pinus pinaster Ait.: lack of growth-reproduction trade-offs but significant effects of climate and tree and stand characteristics

    International Nuclear Information System (INIS)

    Bravo, F.; Maguire, D.A.; González-Martínez, S.G.

    2017-01-01

    Aim of study: Our main goal is to determine the relationship between cone production and radial growth in Pinus pinaster Ait. under different climatic conditions across the Iberian Peninsula. Area of study: Coca Intensive Sampling Plateau, Northern Plateau (Spain). Material and methods: Cone counts were conducted on an intensive monitoring plot in Coca (North-Central Spain) during the years 2000, 2006 and 2007. A ZIP (zero-inflated Poisson) model was adjusted for simultaneously estimating the probability of obtaining crop cones and its amount. The Northern Atlantic Oscillation (NAO) index was used as explanatory variable, together with a wide variety of tree and local stand variables. Climate (as evaluated by NAO), local stand density (here estimated from the six nearest trees), tree size and vigor, competition and growth efficiency significantly influenced both occurrence and intensity of cone production. Main results: ZIP models for predicting reproductive effort seems an adequate tool to predict reproductive responses to climatic fluctuations and the resulting future species distribution in the face of climate change, as well as to identify silviculture actions that would promote reproductive success in naturally-regenerated stands, list and discuss relevant results (including numeric values of experimental results). Research highlights: Climate, stand density and tree conditions (size and vigor, competition and growth efficiency) influence significantly both cone occurrence and intensity of fruiting as shown by a ZIP model. As the climate variables included in the model (based on Northern Atlantic Oscillation, NAO) are general and easily obtained, the proposed model has practical applicability to predicting Pinus pinaster cone production in the Iberian Peninsula.

  1. Coupled Model Intercomparison Project 5 (CMIP5) simulations of climate following volcanic eruptions

    KAUST Repository

    Driscoll, Simon

    2012-09-16

    The ability of the climate models submitted to the Coupled Model Intercomparison Project 5 (CMIP5) database to simulate the Northern Hemisphere winter climate following a large tropical volcanic eruption is assessed. When sulfate aerosols are produced by volcanic injections into the tropical stratosphere and spread by the stratospheric circulation, it not only causes globally averaged tropospheric cooling but also a localized heating in the lower stratosphere, which can cause major dynamical feedbacks. Observations show a lower stratospheric and surface response during the following one or two Northern Hemisphere (NH) winters, that resembles the positive phase of the North Atlantic Oscillation (NAO). Simulations from 13 CMIP5 models that represent tropical eruptions in the 19th and 20th century are examined, focusing on the large-scale regional impacts associated with the large-scale circulation during the NH winter season. The models generally fail to capture the NH dynamical response following eruptions. They do not sufficiently simulate the observed post-volcanic strengthened NH polar vortex, positive NAO, or NH Eurasian warming pattern, and they tend to overestimate the cooling in the tropical troposphere. The findings are confirmed by a superposed epoch analysis of the NAO index for each model. The study confirms previous similar evaluations and raises concern for the ability of current climate models to simulate the response of a major mode of global circulation variability to external forcings. This is also of concern for the accuracy of geoengineering modeling studies that assess the atmospheric response to stratosphere-injected particles.

  2. Extratropical cyclone variability in the Northern Hemisphere winter from the NCEP/NCAR reanalysis data

    Energy Technology Data Exchange (ETDEWEB)

    Gulev, S.K.; Zolina, O.; Grigoriev, S. [AN SSSR, Moscow (USSR). Inst. Okeanologii

    2001-07-01

    The winter climatology of Northern Hemisphere cyclone activity was derived from 6-hourly NCEP/NCAR reanalysis data for the period from 1958 to 1999, using software which provides improved accuracy in cyclone identification in comparison to numerical tracking schemes. Cyclone characteristics over the Kuroshio and Gulfstream are very different to those over continental North America and the Arctic. Analysis of Northern Hemisphere cyclones shows secular and decadal-scale changes in cyclone frequency, intensity, lifetime and deepening rates. The western Pacific and Atlantic are characterized by an increase in cyclone intensity and deepening during the 42-year period, although the eastern Pacific and continental North America demonstrate opposite tendencies in most cyclone characteristics. There is an increase of the number of cyclones in the Arctic and in the western Pacific and a downward tendency over the Gulf Stream and subpolar Pacific. Decadal scale variability in cyclone activity over the Atlantic and Pacific exhibits south-north dipole-like patterns. Atlantic and Pacific cyclone activity associated with the NAO and PNA is analyzed. Atlantic cyclone frequency demonstrates a high correlation with NAO and reflects the NAO shift in the mid 1970s, associated with considerable changes in European storm tracks. The PNA is largely linked to the eastern Pacific cyclone frequencies, and controls cyclone activity over the Gulf region and the North American coast during the last two decades. Assessment of the accuracy of the results and comparison with those derived using numerical algorithms, shows that biases inherent in numerical procedures are not negligible. (orig.)

  3. Sensitivity of the regional climate in the Middle East and North Africa to volcanic perturbations

    Science.gov (United States)

    Dogar, Muhammad Mubashar; Stenchikov, Georgiy; Osipov, Sergey; Wyman, Bruce; Zhao, Ming

    2017-08-01

    The Middle East and North Africa (MENA) regional climate appears to be extremely sensitive to volcanic eruptions. Winter cooling after the 1991 Pinatubo eruption far exceeded the mean hemispheric temperature anomaly, even causing snowfall in Israel. To better understand MENA climate variability, the climate responses to the El Chichón and Pinatubo volcanic eruptions are analyzed using observations, NOAA/National Centers for Environmental Prediction Climate Forecast System Reanalysis, and output from the Geophysical Fluid Dynamics Laboratory's High-Resolution Atmospheric Model. A multiple regression analysis both for the observations and the model output is performed on seasonal summer and winter composites to separate out the contributions from climate trends, El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Indian summer monsoon, and volcanic aerosols. Strong regional temperature and precipitation responses over the MENA region are found in both winter and summer. The model and the observations both show that a positive NAO amplifies the MENA volcanic winter cooling. In boreal summer, the patterns of changing temperature and precipitation suggest a weakening and southward shift of the Intertropical Convergence Zone, caused by volcanic surface cooling and weakening of the Indian and West African monsoons. The model captures the main features of the climate response; however, it underestimates the total cooling, especially in winter, and exhibits a different spatial pattern of the NAO climate response in MENA compared to the observations. The conducted analysis sheds light on the internal mechanisms of MENA climate variability and helps to selectively diagnose the model deficiencies.

  4. ROILA : RObot Interaction LAnguage

    NARCIS (Netherlands)

    Mubin, O.

    2011-01-01

    The number of robots in our society is increasing rapidly. The number of service robots that interact with everyday people already outnumbers industrial robots. The easiest way to communicate with these service robots, such as Roomba or Nao, would be natural speech. However, the limitations

  5. Creating robots with personality : the effect of personality on social intelligence

    NARCIS (Netherlands)

    Mileounis, A.; Cuijpers, R.H.; Barakova, E.I.

    2015-01-01

    This study investigates the effect of two personality traits, dominance and extroversion, on social intelligence. To test these traits, a NAO robot was used, which was teleoperated through a computer using a Wizard of Oz technique. A within-subject design was conducted with extroversion as

  6. Episodes of aeolian sand movement on a large spit system (Skagen Odde, Denmark) and North Atlantic storminess during the Little Ice Age

    DEFF Research Database (Denmark)

    Clemmensen, Lars B.; Glad, Aslaug C.; Hansen, Kristian W. T.

    2015-01-01

    . A change in the atmospheric circulation, so that both the North Atlantic Oscillation (NAO) and the Atlantic Multidecadal Oscillation (AMO) were negative, apparently led to an increased number of intense cyclones causing inland sand movement and dune building. The second and third phase of aeolian sand...

  7. Structural modification of swai-fish (Pangasius hypophthalmus)-based emulsions containing non-meat protein additives by ultra-high pressure and thermal treatments

    Science.gov (United States)

    Techarang, Jiranat; Apichartsrangkoon, Arunee; Phanchaisri, Boonrak; Pathomrungsiyoungkul, Pattavara; Sriwattana, Sujinda

    2017-07-01

    Swai-fish emulsions containing fermented soybeans (thua nao and rice-koji miso) were pressurized at 600 MPa for 20 min or heated at 72°C for 30 min. The fish batters were blended with soy protein isolate (SPI) or whey protein concentrate (WPC) to stabilize the emulsions. The processed fish emulsions were then subjected to physical, chemical and microbiological examinations. The results of gel strength and water-holding potential showed that SPI addition yielded higher impact on these properties than WPC addition, which was also confirmed by the interactions between SPI and native fish proteins depicted by electrophoregrams. The frequency profiles suggested that the heated gels had a greater storage and loss moduli than pressurized gels, while pressurized WPC set-gel displayed larger loss tangent (the predominance of viscous moiety) than those pressurized SPI set-gel. High bacteria and spore counts of B. subtilis (residual of the thua nao) were observed in both pressurized and heated fish-based emulsions.

  8. Current-voltage curve of sodium channels and concentration dependence of sodium permeability in frog skin

    DEFF Research Database (Denmark)

    Fuchs, W; Larsen, Erik Hviid; Lindemann, B

    1977-01-01

    1. The inward facing membranes of in vitro frog skin epithelium were depolarized with solutions of high K concentration. The electrical properties of the epithelium are then expected to be governed by the outward facing, Na-selective membrane.2. In this state, the transepithelial voltage (V...... was recorded. This procedure was repeated after blocking the Na channels with amiloride to obtain the current-voltage curve of transmembrane and paracellular shunt pathways. The current-voltage curve of the Na channels was computed by subtracting the shunt current from the total current.4. The instantaneous I...... of the inward facing membranes but reflects the true behaviour of P(Na).6. The steady-state P(Na) at a given (Na)(o) is smaller than the transient P(Na) observed right after a stepwise increase of (Na)(o) to this value. The time constant of P(Na)-relaxation is in the order of seconds.7. In conclusion, Na...

  9. Seasonal forecasts of northern hemisphere winter 2009/10

    International Nuclear Information System (INIS)

    Fereday, D R; Maidens, A; Arribas, A; Scaife, A A; Knight, J R

    2012-01-01

    Northern hemisphere winter 2009/10 was exceptional for atmospheric circulation: the North Atlantic Oscillation (NAO) index was the lowest on record for over a century. This contributed to cold conditions over large areas of Eurasia and North America. Here we use two versions of the Met Office GloSea4 seasonal forecast system to investigate the predictability of this exceptional winter. The first is the then operational version of GloSea4, which uses a low top model and successfully predicted a negative NAO in forecasts produced in September, October and November 2009. The second uses a new high top model, which better simulates sudden stratospheric warmings (SSWs). This is particularly relevant for 2009/10 due to its unusual combination of a strong El Niño and an easterly quasi-biennial oscillation (QBO) phase, favouring SSW development. SSWs are shown to play an influential role in surface conditions, producing a stronger sea level pressure signal and improving predictions of the 2009/10 winter. (letter)

  10. Linkages between Icelandic Low position and SE Greenland winter precipitation

    Science.gov (United States)

    Berdahl, M.; Rennermalm, A. K.; Hammann, A. C.; Mioduszewski, J.; Hameed, S.; Tedesco, M.; Stroeve, J. C.; Mote, T. L.

    2015-12-01

    Greenland's largest flux of precipitation occurs in its Southeast (SE) region. An understanding of the mechanisms controlling precipitation in this region is lacking despite its disproportionate importance in the mass balance of Greenland and the consequent contributions to sea level rise. We use weather station data from the Danish Meteorological Institute to reveal the governing influences on precipitation in SE Greenland during the winter and fall. We find that precipitation in the fall is significantly correlated to the longitude of the Icelandic Low and the NAO. Winter precipitation is correlated with the strength and longitude of the Icelandic Low, as well as the NAO. We show that in years of extreme high precipitation, onshore winds dominate, thereby advecting more moisture inland. In low precipitation years, winds are more westerly, approaching the stations from land. Understanding the controls of SE Greenland precipitation will help us predict how future precipitation in this key region may change in a warming climate.

  11. A Reassessment of the Integrated Impact of Tropical Cyclones on Surface Chlorophyll in the Western Subtropical North Atlantic

    Energy Technology Data Exchange (ETDEWEB)

    Foltz, Gregory R.; Balaguru, Karthik; Leung, Lai-Yung R.

    2015-02-28

    The impact of tropical cyclones on surface chlorophyll concentration is assessed in the western subtropical North Atlantic Ocean during 1998–2011. Previous studies in this area focused on individual cyclones and gave mixed results regarding the importance of tropical cyclone-induced mixing for changes in surface chlorophyll. Using a more integrated and comprehensive approach that includes quantification of cyclone-induced changes in mixed layer depth, here it is shown that accumulated cyclone energy explains 22% of the interannual variability in seasonally-averaged (June–November) chlorophyll concentration in the western subtropical North Atlantic, after removing the influence of the North Atlantic Oscillation (NAO). The variance explained by tropical cyclones is thus about 70% of that explained by the NAO, which has well-known impacts in this region. It is therefore likely that tropical cyclones contribute significantly to interannual variations of primary productivity in the western subtropical North Atlantic during the hurricane season.

  12. Statistical-dynamic climate forecast for Europe and Germany. Final report; Statistisch-dynamische Klimavorhersage fuer Europa und Deutschland. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Denhard, M.; Schoenwiese, C.D.

    2001-07-01

    Principal Correlation Pattern Analysis (PCPA) maps the local circulation, temperature and precipitation anomalies in the northern hemisphere in monthly resolution and permits an interpretation of their causes. Calculations are made for the El Nino phenomenon, NAO, and the quasi-11-year cycle of solar radiation variation. Especially the El Nino calculations show the efficiency of PCPA. [German] Mit Hilfe der Principal Correlation Pattern Analysis (PCPA) koennen die von verschiedenen Klimaantrieben erzeugten lokalen Zirkulations-, Temperatur- und Niederschlagsanomalien auf der Nordhemisphaere in monatlicher Aufloesung dargestellt und ursaechlich interpretiert werden. Diese Rechnungen wurden fuer das El Nino Phaenomen, die NAO und den quasi 11-jaehrigen Zyklus der solaren Strahlungsschwankungen durchgefuehrt. Insbesondere die Untersuchungen zu Wirkungen von El Nino auf Europa zeigen, dass die PCPA die Kopplungen eines Prozesses mit dem Klimasystem sehr genau beschreibt und somit die Voraussetzungen schafft, die Wirkungen dieses Klimaantriebs zu modellieren und ihn zur Vorhersage zu nutzen. Erste einfache Vorhersageexperimente fuer das europaeische Klima bestaetigen diese Aussage. (orig.)

  13. A Review of Selected International Aircraft Spares Pooling Programs: Lessons Learned for F-35 Spares Pooling

    Science.gov (United States)

    2016-01-01

    Applications Global Marketing Brochure, Eurofighter GmbH Case Study, September 2006. 39 The NAO is equivalent to the U.S. Government Accountability Office...www.publications.parliament.uk/pa/cm201011/cmselect/cmpubacc/860/860we01.htm IFS, IFS Applications Global Marketing Brochure, Eurofighter GmbH Case Study

  14. Child's recognition of emotions in robot's face and body

    NARCIS (Netherlands)

    Cohen, I.; Looije, R.; Neerincx, M.A.

    2011-01-01

    Social robots can comfort and support children who have to cope with chronic diseases. In previous studies, a "facial robot", the iCat, proved to show well-recognized emotional expressions that are important in social interactions. The question is if a mobile robot without a face, the Nao, can

  15. CPC - Climate Weather Linkage: El Niño Southern Oscillation

    Science.gov (United States)

    Teleconnections AO NAO PNA AAO Blocking Storm Tracks Climate Glossary Outreach About Us Our Mission Who We Are . P., and A. Kumar, 2000: Understanding and predicting extratropical teleconnections related to ENSO extratropical circulation anomalies during the 1986-1989 ENSO cycle. J. Climate, 6, 595-616. Ropelewski, C. F

  16. Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions

    Science.gov (United States)

    Macmynowski, Dena P.; Root, Terry L.

    2007-05-01

    The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979 2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species’ arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species’ responses to changing climate as well as evaluate the underlying biological mechanisms.

  17. Analysis and standardization of landings per unit effort of red shrimp Aristeus antennatus from the trawl fleet of Barcelona (NW Mediterranean

    Directory of Open Access Journals (Sweden)

    Valeria Mamouridis

    2014-03-01

    Full Text Available Monthly landings and effort data from the Barcelona trawl fleet (NW Mediterranean were selected to analyse and standardize the landings per unit effort (LPUE of the red shrimp (Aristeus antennatus using generalized additive models. The dataset covers a span of 15 years (1994-2008 and consists of a broad spectrum of predictors: fleet-dependent (e.g. number of trips performed by vessels and their technical characteristics, such as the gross registered tonnage, temporal (inter- and intra-annual variability, environmental (North Atlantic Oscillation [NAO] index and economic (red shrimp and fuel prices variables. All predictors individually have an impact on LPUE, though some of them lose their predictive power when considered jointly. That is the case of the NAO index. Our results show that six variables from the whole set can be incorporated into a global model with a total explained deviance (ED of 43%. We found that the most important variables were effort-related predictors (trips, tonnage, and groups with a total ED of 20.58%, followed by temporal variables, with an ED of 13.12%, and finally the red shrimp price as an economic predictor with an ED of 9.30%. Taken individually, the main contributing variable was the inter-annual variability (ED=12.40%. This high ED value suggests that many factors correlated with inter-annual variability, such as environmental factors (the NAO in specific years and fuel price, could in turn affect LPUE variability. The standardized LPUE index with the effort variability removed was found to be similar to the fishery-independent abundance index derived from the MEDITS programme.

  18. The use of new technologies for nutritional education in primary schools: a pilot study.

    Science.gov (United States)

    Rosi, A; Dall'Asta, M; Brighenti, F; Del Rio, D; Volta, E; Baroni, I; Nalin, M; Coti Zelati, M; Sanna, A; Scazzina, F

    2016-11-01

    The aim of this study was evaluating if the presence of a humanoid robot could improve the efficacy of a game-based, nutritional education intervention. This was a controlled, school-based pilot intervention carried out on fourth-grade school children (8-10 years old). A total of 112 children underwent a game-based nutritional educational lesson on the importance of carbohydrates. For one group (n = 58), the lesson was carried out by a nutritional educator, the Master of Taste (MT), whereas for another group, (n = 54) the Master of Taste was supported by a humanoid robot (MT + NAO). A third group of children (n = 33) served as control not receiving any lesson. The intervention efficacy was evaluated by questionnaires administered at the beginning and at the end of each intervention. The nutritional knowledge level was evaluated by the cultural-nutritional awareness factor (AF) score. A total of 290 questionnaires were analyzed. Both MT and MT + NAO interventions significantly increased nutritional knowledge. At the end of the study, children in the MT and MT + NAO group showed similar AF scores, and the AF scores of both intervention groups were significantly higher than the AF score of the control group. This study showed a significant increase in the nutritional knowledge of children involved in a game-based, single-lesson, educational intervention performed by a figure that has a background in food science. However, the presence of a humanoid robot to support this figure's teaching activity did not result in any significant learning improvement. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  19. Quilotórax: A propósito de um caso clínico Chylothorax - Case report

    Directory of Open Access Journals (Sweden)

    Ricardo José Brito Pereira de Lima

    2009-05-01

    Full Text Available O quilotorax caracteriza-se pela presença de linfa no espaço pleural devido a lesão ou obstrução do ducto torácico. O diagnostico e feito com base no elevado conteúdo de trigliceridos e na presença de quilomicrons. A etiologia do quilotorax pode ser dividida em traumática e nao traumática. A ruptura traumática ocorre após acidentes ou cirurgias. Das causas não traumáticas, a mais comum e o linfoma e, na presença de um quilotorax de etiologia desconhecida, a primeira suspeita diagnostica devera ser dirigida para esta entidade, sendo o tipo mais frequente o nao Hodgkin. Os autores apresentam o caso de um doente com quilotorax, cujo diagnóstico etiológico foi de linfoma nao Hodgkin, discutem os aspectos particulares do quilotorax, bem como a investigação e modalidades de tratamento desta entidade.Chylothorax is the occurrence of lymph in the pleura due to damage or obstruction of the thoracic duct. High content of triglycerides and the presence of chylomicrons make the diagnosis of chylothorax. Its aetiology can be divided in traumatic and non-traumatic. Traumatic rupture occurs after accidents or surgery. Within non -traumatic aetiology, lymphoma is the most common and in the presence of a chylothorax of unknown origin this should be the first suspicion, being non -Hodgkin type the most frequent. The authors present a case report of a patient with chylothorax due to non -Hodgkin lymphoma, discuss the particularities of chylothorax as well as the investigation and its treatment options.

  20. Atmospheric teleconnection influence on North American land surface phenology

    Science.gov (United States)

    Dannenberg, Matthew P.; Wise, Erika K.; Janko, Mark; Hwang, Taehee; Kolby Smith, W.

    2018-03-01

    Short-term forecasts of vegetation activity are currently not well constrained due largely to our lack of understanding of coupled climate-vegetation dynamics mediated by complex interactions between atmospheric teleconnection patterns. Using ecoregion-scale estimates of North American vegetation activity inferred from remote sensing (1982-2015), we examined seasonal and spatial relationships between land surface phenology and the atmospheric components of five teleconnection patterns over the tropical Pacific, north Pacific, and north Atlantic. Using a set of regression experiments, we also tested for interactions among these teleconnection patterns and assessed predictability of vegetation activity solely based on knowledge of atmospheric teleconnection indices. Autumn-to-winter composites of the Southern Oscillation Index (SOI) were strongly correlated with start of growing season timing, especially in the Pacific Northwest. The two leading modes of north Pacific variability (the Pacific-North American, PNA, and West Pacific patterns) were significantly correlated with start of growing season timing across much of southern Canada and the upper Great Lakes. Regression models based on these Pacific teleconnections were skillful predictors of spring phenology across an east-west swath of temperate and boreal North America, between 40°N-60°N. While the North Atlantic Oscillation (NAO) was not strongly correlated with start of growing season timing on its own, we found compelling evidence of widespread NAO-SOI and NAO-PNA interaction effects. These results suggest that knowledge of atmospheric conditions over the Pacific and Atlantic Oceans increases the predictability of North American spring phenology. A more robust consideration of the complexity of the atmospheric circulation system, including interactions across multiple ocean basins, is an important step towards accurate forecasts of vegetation activity.

  1. Climatology and internal variability in a 1000-year control simulation with the coupled climate model ECHO-G

    Energy Technology Data Exchange (ETDEWEB)

    Min, S.K.; Hense, A. [Bonn Univ. (Germany). Meteorologisches Inst.; Legutke, S.; Kwon, W.T. [Korea Meteorological Administration, Seoul (Korea). Meteorological Research Inst.

    2004-03-01

    The climatology and internal variability in a 1000-year control simulation of the coupled atmosphere-ocean global climate model ECHO-G are analyzed and compared with observations and other coupled climate model simulations. ECHO-G requires annual mean flux corrections for heat and freshwater in order to simulate no climate drift for 1000 years, but no flux corrections for momentum. The ECHO-G control run captures well most aspects of the observed seasonal and annual climatology and of the interannual to decadal variability. Model biases are very close to those in ECHAM4 stand-alone integrations with prescribed observed sea surface temperature. A trend comparison between observed and modeled near surface temperatures shows that the observed global warming at near surface level is beyond the range of internal variability produced by ECHO-G. The simulated global mean near surface temperatures, however, show a two-year spectral peak which is linked with a strong biennial bias of energy in the ENSO signal. Consequently, the interannual variability (3-9 years) is underestimated. The overall ENSO structure such as the tropical SST climate and its seasonal cycle, a single ITCZ in the eastern tropical Pacific, and the ENSO phase-locking to the annual cycle are simulated reasonably well by ECHO-G. However, the amplitude of SST variability is overestimated in the eastern equatorial pacific and the observed westward propagation of zonal wind stress over the equatorial pacific is not captured by the model. ENSO-related teleconnection patterns of near surface temperature, precipitation, and mean sea level pressure are reproduced realistically. The station-based NAO index in the model exhibits a 'white' noise spectrum similar to the observed and the NAO-related patterns of near surface temperature, precipitation, and mean sea level pressure are also simulated successfully. However, the model overestimates the additional warming over the north pacific in the high index

  2. Maadili Ya Utafiti | Mukuthuria | Kiswahili

    African Journals Online (AJOL)

    Maadili ni kaida zinazoelekeza tabia zetu katika mahusiano yetu ya kila siku na wenzetu (taz. Mathooko na wenzie, 2007:15). Katika utafiti, maadili ni uwajibikaji na uwelekevu kitabia kuhusiana na haki za wale wote tunaotangamana nao katika utafiti, uwelekevu katika nia na malengo ya utafiti na jinsi ya kutumia matokeo ...

  3. Flowering of allergenically important plant species in relation to the North Atlantic Oscillation system and thermal time in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hájková, L.; Hubálek, Zdeněk; Kožnarová, V.; Bartošová, Lenka; Možný, M.

    2018-01-01

    Roč. 34, č. 2 (2018), s. 157-169 ISSN 0393-5965 R&D Projects: GA MŠk(CZ) LO1415; GA MZe QJ1310123 Institutional support: RVO:68081766 ; RVO:67179843 Keywords : NAO * Allergology * Czech Republic * Onset of flowering * Climate change * GDD * Soil temperature Impact factor: 2.202, year: 2016

  4. Causas de remocao nao eletiva do cateter epicutaneo em neonatos

    Directory of Open Access Journals (Sweden)

    Eny Dorea Paiva

    2013-12-01

    Full Text Available Objetivou-se descrever a incidência e as razões de remoção não eletiva do cateter epicutâneo em neonatos, verificando a associação com o sítio de inserção. Estudo de coorte prospectivo realizado em unidade de cuidado intensivo neonatal de um hospital privado terciário na cidade de São Paulo. Foram analisadas 266 inserções de cateter epicutâneo. A incidência de remoção não eletiva foi 39,1%. As complicações pós-inserção mais frequentes foram suspeita de infecção de corrente sanguínea relacionada ao cateter (25% e ruptura (23,1%. A maioria dos cateteres foi inserida através do hemisfério corporal direito (65%, membros superiores (77,1% e veias axilares (31,2%. Os resultados sugerem não haver associação entre a incidência de remoção não eletiva e o sítio de inserção do cateter epicutâneo em neonatos. Compete à Enfermagem implementar estratégias para a melhoria da prática assistencial a fim de diminuir a frequência de remoções não eletivas do cateter epicutâneo em neonatos.

  5. Government Policy in England on the Financing of ITT: Value for Money or a Waste of Resources?

    Science.gov (United States)

    Hilton, Gillian L. S.

    2017-01-01

    A recent report by the National Audit Office (NAO, 2016) has criticised the Department of Education's organisation of Initial Teacher Training programmes in England as not providing value for money. This paper explores recent reports from government agencies, Parliament and the press on this issue. Further to this, leaders of various programmes…

  6. Tree-ring reconstruction of streamflow in the Snare River Basin, Northwest Territories, Canada

    Science.gov (United States)

    Martin, J. P.; Pisaric, M. F.

    2017-12-01

    Drought is a component of many ecosystems in North America causing environmental and socioeconomical impacts. In the ongoing context of climatic and environmental changes, drought-related issues are becoming problematic in northern Canada, which have not been associated with drought-like conditions in the past. Dryer than average conditions threatens the energy security of northern canadian communities, since this region relies on the production of hydroelectricity as an energy source. In the North Slave Region of Northwest Territory (NWT), water levels and streamflows were significantly lower in 2014/2015. The Government of the NWT had to spend nearly $50 million to purchase diesel fuel to generate enough electricity to supplement the reduced power generation of the Snare River hydroelectric system, hence the need to better understand the multi-decadal variability in streamflow. The aims of this presentation are i) to present jack pine and white spruce tree-ring chronologies of Southern NWT; ii) to reconstruct past streamflow of the Snare River Basin; iii) to evaluate the frequency and magnitude of extreme drought conditions, and iv) to identify which large-scale atmospheric or oceanic patterns are teleconnected to regional hydraulic conditions. Preliminary results show that the growth of jack pine and white spruce populations is better correlated with precipitation and temperature, respectively, than hydraulic conditions. Nonetheless, we present a robust streamflow reconstruction of the Snare River that is well correlated with the summer North Atlantic Oscillation (NAO) index, albeit the strength of the correlation is non-stationary. Spectral analysis corroborate the synchronicity between negative NAO conditions and drought conditions. From an operational standpoint, considering that the general occurrence of positive/negative NAO can be predicted, it the hope of the authors that these results can facilitate energetic planning in the Northwest Territories through

  7. Long-term trends in first arrival and first egg laying dates of some migrant and resident bird species in northern Italy

    Science.gov (United States)

    Rubolini, Diego; Ambrosini, Roberto; Caffi, Mario; Brichetti, Pierandrea; Armiraglio, Stefano; Saino, Nicola

    2007-08-01

    Climate change is affecting the phenology of seasonal events in Europe and the Northern Hemisphere, as shown by several studies of birds’ timing of migration and reproduction. Here, we analyse the long-term (1982-2006) trends of first arrival dates of four long-distance migratory birds [swift ( Apus apus), nightingale ( Luscinia megarhynchos), barn swallow ( Hirundo rustica), and house martin ( Delichon urbicum)] and first egg laying dates of two migrant (swift, barn swallow) and two resident species [starling ( Sturnus vulgaris), Italian sparrow ( Passer italiae)] at a study site in northern Italy. We also addressed the effects of local weather (temperature and precipitation) and a climate index (the North Atlantic Oscillation, NAO) on the interannual variability of phenological events. We found that the swift and the barn swallow significantly advanced both arrival and laying dates, whereas all other species did not show any significant temporal trend in either arrival or laying date. The earlier arrival of swifts was explained by increasing local temperatures in April, whereas this was not the case for arrival dates of swallows and first egg laying dates of both species. In addition, arrival dates of house martins were earlier following high NAO winters, while nightingale arrival was earlier when local spring rainfall was greater. Finally, Italian sparrow onset of reproduction was anticipated by greater spring rainfall, but delayed by high spring NAO anomalies, and swift’s onset of reproduction was anticipated by abundant rainfall prior to reproduction. There were no significant temporal trends in the interval between onset of laying and arrival in either the swift or the barn swallow. Our findings therefore indicate that birds may show idiosyncratic responses to climate variability at different spatial scales, though some species may be adjusting their calendar to rapidly changing climatic conditions.

  8. Nonstationarities in the occurrence rates of flood events in Portuguese watersheds

    Directory of Open Access Journals (Sweden)

    A. T. Silva

    2012-01-01

    Full Text Available An exploratory analysis on the variability of flood occurrence rates in 10 Portuguese watersheds is made, to ascertain if that variability is concurrent with the principle of stationarity. A peaks-over-threshold (POT sampling technique is applied to 10 long series of mean daily streamflows and to 4 long series of daily rainfall in order to sample the times of occurrence (POT time data of the peak values of those series. The kernel occurrence rate estimator, coupled with a bootstrap approach, was applied to the POT time data to obtain the time dependent estimated occurrence rate curves, λˆ(t, of floods and extreme rainfall events. The results of the analysis show that the occurrence of those events constitutes an inhomogeneous Poisson process, hence the occurrence rates are nonstationary. An attempt was made to assess whether the North Atlantic Oscillation (NAO casted any influence on the occurrence rate of floods in the study area. Although further research is warranted, it was found that years with a less-than-average occurrence of floods tend to occur when the winter NAO is in the positive phase, and years with a higher occurrence of floods (more than twice the average tend to occur when the winter NAO is in the negative phase. Although the number of analyzed watersheds and their uneven spatial distribution hinders the generalization of the findings to the country scale, the authors conclude that the mathematical formulation of the flood frequency models relying on stationarity commonly employed in Portugal should be revised in order to account for possible nonstationarities in the occurrence rates of such events.

  9. Mediterranean Thermohaline Response to Large-Scale Winter Atmospheric Forcing in a High-Resolution Ocean Model Simulation

    Science.gov (United States)

    Cusinato, Eleonora; Zanchettin, Davide; Sannino, Gianmaria; Rubino, Angelo

    2018-04-01

    Large-scale circulation anomalies over the North Atlantic and Euro-Mediterranean regions described by dominant climate modes, such as the North Atlantic Oscillation (NAO), the East Atlantic pattern (EA), the East Atlantic/Western Russian (EAWR) and the Mediterranean Oscillation Index (MOI), significantly affect interannual-to-decadal climatic and hydroclimatic variability in the Euro-Mediterranean region. However, whereas previous studies assessed the impact of such climate modes on air-sea heat and freshwater fluxes in the Mediterranean Sea, the propagation of these atmospheric forcing signals from the surface toward the interior and the abyss of the Mediterranean Sea remains unexplored. Here, we use a high-resolution ocean model simulation covering the 1979-2013 period to investigate spatial patterns and time scales of the Mediterranean thermohaline response to winter forcing from NAO, EA, EAWR and MOI. We find that these modes significantly imprint on the thermohaline properties in key areas of the Mediterranean Sea through a variety of mechanisms. Typically, density anomalies induced by all modes remain confined in the upper 600 m depth and remain significant for up to 18-24 months. One of the clearest propagation signals refers to the EA in the Adriatic and northern Ionian seas: There, negative EA anomalies are associated to an extensive positive density response, with anomalies that sink to the bottom of the South Adriatic Pit within a 2-year time. Other strong responses are the thermally driven responses to the EA in the Gulf of Lions and to the EAWR in the Aegean Sea. MOI and EAWR forcing of thermohaline properties in the Eastern Mediterranean sub-basins seems to be determined by reinforcement processes linked to the persistency of these modes in multiannual anomalous states. Our study also suggests that NAO, EA, EAWR and MOI could critically interfere with internal, deep and abyssal ocean dynamics and variability in the Mediterranean Sea.

  10. Synthesis and thermal properties of the MA/HDPE composites with nano-additives as form-stable PCM with improved thermal conductivity

    International Nuclear Information System (INIS)

    Tang, Yaojie; Su, Di; Huang, Xiang; Alva, Guruprasad; Liu, Lingkun; Fang, Guiyin

    2016-01-01

    Highlights: • MA/HDPE composites with nano-additives were prepared for thermal conductivity enhancement. • Microstructure and chemical structure of the FSPCM were analyzed. • Thermal properties and thermal reliability of the FSPCM were investigated. • Thermal conductivity of the FSPCM can be enhanced by adding NAO and NG. - Abstract: For the purpose of improving the thermal conductivity of the form–stable phase change materials (FSPCM), two types of nano–powders with high thermal conductivity were added into the samples. In the modified FSPCM, myristic acid (MA) was used as a solid–liquid phase change material (PCM), high density polyethylene (HDPE) acted as supporting material to prevent the leakage of the melted MA. Nano–Al 2 O 3 (NAO) and nano–graphite (NG) were the additives for thermal conductivity enhancement. Scanning electronic microscope (SEM), Fourier transformation infrared spectroscope (FT–IR) and X-ray diffractometer (XRD) were used to analyze the microstructure, chemical structure and crystalline phase of the samples, respectively. Furthermore, the specific latent heat and phase transition temperature, thermal conductivity and thermal reliability were investigated using differential scanning calorimeter (DSC), thermal conductivity meter and thermo–gravimetric analyzer (TGA). The results showed that the MA was uniformly absorbed in the HDPE matrices and there was no leakage during the melting process when the mass fraction of the MA in the MA/HDPE composite was less than 70%. The DSC results revealed that the modified FSPCM have a constant phase change temperature and high specific latent heat. The thermal conductivity of the FSPCM was measured in the solid (30 °C) and liquid (60 °C) states of the MA. When the mass fraction of nano–powder additives is 12%, the thermal conductivities of the FSPCM increase by 95% (NAO) and 121% (NG) at 30 °C. It is anticipated that the FSPCM possess a potential application for thermal energy

  11. Comparison of N-alkyl acridine orange dyes as fluorescence probes for the determination of cardiolipin

    Energy Technology Data Exchange (ETDEWEB)

    Kaewsuya, P.; Miller, J.D. [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States); Danielson, N.D. [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States)], E-mail: danielnd@muohio.edu; Sanjeevi, J.; James, P.F. [Department of Zoology, Miami University, Oxford, OH 45056 (United States)

    2008-09-26

    The phospholipid (PL), cardiolipin (CL), is found almost exclusively in the inner membrane of mitochondria and loss of CL is considered as an important indication of cell apoptosis. Previously, 10-N-nonyl acridine orange (NAO) has been used as a fluorescent probe for the visualization of CL in mitochondrial cell membranes and in solution. In this work for the determination of CL, we have synthesized two new fluorescent probes, n-tetradecyl acridine orange (C14-AO), and n-octadecyl acridine orange (C18-AO) by reacting acridine orange with the corresponding n-alkyl bromide. Using excitation and emission wavelengths at about 500 and 525 nm and varying the percentage of methanol in water as the solvent, no interaction between CL and the fluorescent probes at 75% is noted but a proportional quenching of the fluorescence signal by CL is observed at 50% or less for C14-AO and 60% or less for C18-AO. Binding efficiency of these fluorescent probes to CL is compared using dye concentrations of 5, 10, and 20 {mu}M. C18-AO shows a better sensitivity than C14-AO and NAO, respectively, but is less selective. For C14-AO, the detection limit and limit of quantitation are 0.07 and 0.21 {mu}M, respectively, which are better than those previously reported for NAO. One anionic PL, phosphatidic acid, shows some quenching interference to both the C14 and C18 dyes but only at concentrations above the working range for sample analysis. The CL in mitochondrial membrane samples is determined by standard addition using C14-AO. The level of CL in the outer mitochondrial membrane compared to the inner membrane is significantly increased due to the addition of cadmium chloride into the cells causing cell apoptosis.

  12. Broad-scale climate influences on spring-spawning herring (Clupea harengus, L.) recruitment in the Western Baltic Sea.

    Science.gov (United States)

    Gröger, Joachim P; Hinrichsen, Hans-Harald; Polte, Patrick

    2014-01-01

    Climate forcing in complex ecosystems can have profound implications for ecosystem sustainability and may thus challenge a precautionary ecosystem management. Climatic influences documented to affect various ecological functions on a global scale, may themselves be observed on quantitative or qualitative scales including regime shifts in complex marine ecosystems. This study investigates the potential climatic impact on the reproduction success of spring-spawning herring (Clupea harengus) in the Western Baltic Sea (WBSS herring). To test for climate effects on reproduction success, the regionally determined and scientifically well-documented spawning grounds of WBSS herring represent an ideal model system. Climate effects on herring reproduction were investigated using two global indices of atmospheric variability and sea surface temperature, represented by the North Atlantic Oscillation (NAO) and the Atlantic Multi-decadal Oscillation (AMO), respectively, and the Baltic Sea Index (BSI) which is a regional-scale atmospheric index for the Baltic Sea. Moreover, we combined a traditional approach with modern time series analysis based on a recruitment model connecting parental population components with reproduction success. Generalized transfer functions (ARIMAX models) allowed evaluating the dynamic nature of exogenous climate processes interacting with the endogenous recruitment process. Using different model selection criteria our results reveal that in contrast to NAO and AMO, the BSI shows a significant positive but delayed signal on the annual dynamics of herring recruitment. The westward influence of the Siberian high is considered strongly suppressing the influence of the NAO in this area leading to a higher explanatory power of the BSI reflecting the atmospheric pressure regime on a North-South transect between Oslo, Norway and Szczecin, Poland. We suggest incorporating climate-induced effects into stock and risk assessments and management strategies as part

  13. Post-1980 shifts in the sensitivity of boreal tree growth to North Atlantic Ocean dynamics and seasonal climate. Tree growth responses to North Atlantic Ocean dynamics

    Science.gov (United States)

    Ols, Clémentine; Trouet, Valerie; Girardin, Martin P.; Hofgaard, Annika; Bergeron, Yves; Drobyshev, Igor

    2018-06-01

    The mid-20th century changes in North Atlantic Ocean dynamics, e.g. slow-down of the Atlantic meridional overturning thermohaline circulation (AMOC), have been considered as early signs of tipping points in the Earth climate system. We hypothesized that these changes have significantly altered boreal forest growth dynamics in northeastern North America (NA) and northern Europe (NE), two areas geographically adjacent to the North Atlantic Ocean. To test our hypothesis, we investigated tree growth responses to seasonal large-scale oceanic and atmospheric indices (the AMOC, North Atlantic Oscillation (NAO), and Arctic Oscillation (AO)) and climate (temperature and precipitation) from 1950 onwards, both at the regional and local levels. We developed a network of 6876 black spruce (NA) and 14437 Norway spruce (NE) tree-ring width series, extracted from forest inventory databases. Analyses revealed post-1980 shifts from insignificant to significant tree growth responses to summer oceanic and atmospheric dynamics both in NA (negative responses to NAO and AO indices) and NE (positive response to NAO and AMOC indices). The strength and sign of these responses varied, however, through space with stronger responses in western and central boreal Quebec and in central and northern boreal Sweden, and across scales with stronger responses at the regional level than at the local level. Emerging post-1980 associations with North Atlantic Ocean dynamics synchronized with stronger tree growth responses to local seasonal climate, particularly to winter temperatures. Our results suggest that ongoing and future anomalies in oceanic and atmospheric dynamics may impact forest growth and carbon sequestration to a greater extent than previously thought. Cross-scale differences in responses to North Atlantic Ocean dynamics highlight complex interplays in the effects of local climate and ocean-atmosphere dynamics on tree growth processes and advocate for the use of different spatial scales in

  14. Robustness of serial clustering of extratropical cyclones to the choice of tracking method

    Directory of Open Access Journals (Sweden)

    Joaquim G. Pinto

    2016-07-01

    Full Text Available Cyclone clusters are a frequent synoptic feature in the Euro-Atlantic area. Recent studies have shown that serial clustering of cyclones generally occurs on both flanks and downstream regions of the North Atlantic storm track, while cyclones tend to occur more regulary on the western side of the North Atlantic basin near Newfoundland. This study explores the sensitivity of serial clustering to the choice of cyclone tracking method using cyclone track data from 15 methods derived from ERA-Interim data (1979–2010. Clustering is estimated by the dispersion (ratio of variance to mean of winter [December – February (DJF] cyclone passages near each grid point over the Euro-Atlantic area. The mean number of cyclone counts and their variance are compared between methods, revealing considerable differences, particularly for the latter. Results show that all different tracking methods qualitatively capture similar large-scale spatial patterns of underdispersion and overdispersion over the study region. The quantitative differences can primarily be attributed to the differences in the variance of cyclone counts between the methods. Nevertheless, overdispersion is statistically significant for almost all methods over parts of the eastern North Atlantic and Western Europe, and is therefore considered as a robust feature. The influence of the North Atlantic Oscillation (NAO on cyclone clustering displays a similar pattern for all tracking methods, with one maximum near Iceland and another between the Azores and Iberia. The differences in variance between methods are not related with different sensitivities to the NAO, which can account to over 50% of the clustering in some regions. We conclude that the general features of underdispersion and overdispersion of extratropical cyclones over the North Atlantic and Western Europe are robust to the choice of tracking method. The same is true for the influence of the NAO on cyclone dispersion.

  15. Broad-scale climate influences on spring-spawning herring (Clupea harengus, L. recruitment in the Western Baltic Sea.

    Directory of Open Access Journals (Sweden)

    Joachim P Gröger

    Full Text Available Climate forcing in complex ecosystems can have profound implications for ecosystem sustainability and may thus challenge a precautionary ecosystem management. Climatic influences documented to affect various ecological functions on a global scale, may themselves be observed on quantitative or qualitative scales including regime shifts in complex marine ecosystems. This study investigates the potential climatic impact on the reproduction success of spring-spawning herring (Clupea harengus in the Western Baltic Sea (WBSS herring. To test for climate effects on reproduction success, the regionally determined and scientifically well-documented spawning grounds of WBSS herring represent an ideal model system. Climate effects on herring reproduction were investigated using two global indices of atmospheric variability and sea surface temperature, represented by the North Atlantic Oscillation (NAO and the Atlantic Multi-decadal Oscillation (AMO, respectively, and the Baltic Sea Index (BSI which is a regional-scale atmospheric index for the Baltic Sea. Moreover, we combined a traditional approach with modern time series analysis based on a recruitment model connecting parental population components with reproduction success. Generalized transfer functions (ARIMAX models allowed evaluating the dynamic nature of exogenous climate processes interacting with the endogenous recruitment process. Using different model selection criteria our results reveal that in contrast to NAO and AMO, the BSI shows a significant positive but delayed signal on the annual dynamics of herring recruitment. The westward influence of the Siberian high is considered strongly suppressing the influence of the NAO in this area leading to a higher explanatory power of the BSI reflecting the atmospheric pressure regime on a North-South transect between Oslo, Norway and Szczecin, Poland. We suggest incorporating climate-induced effects into stock and risk assessments and management

  16. Robotic Literacy Learning Companions: Exploring Student Engagement with a Humanoid Robot in an Afterschool Literacy Program

    Science.gov (United States)

    Levchak, Sofia

    2016-01-01

    This study was an investigation of the use of a NAO humanoid robot as an effective tool for engaging readers in an afterschool program as well as to find if increasing engagement using a humanoid robot would affect students' reading comprehension when compared to traditional forms of instruction. The targeted population of this study was…

  17. A Riccati model for Denmark Strait overflow variability

    Science.gov (United States)

    Käse, R. H.

    2006-10-01

    A controlled volume box model of the western basins of the Nordic Seas for water denser than 1027.8 kg m-3 is constructed, where accumulation in volume ($\\frac{dV}{dt) is driven by net imbalances between prescribed net inflow from the northern, eastern and top boundaries (Qs) and hydraulically limited outflow through the Denmark Strait. The resulting Riccati equation is solved analytically for filling and flushing experiments with constant Qs and numerically for stochastic forcing Qs(t). For small perturbations to Qs with white noise spectrum, the overflow response is red noise with a time scale between 5 and 15 years depending on the mean interface height and area. For Qs proportional to the NAO index, the overflow is positively correlated with the NAO. A 140 years integration reveals variations in the overflow between 2.5 Sv in the 1970s and a maximum of 4 Sv in the 1990s. Hydraulic transport calculations from hydrographic data north of Iceland show good agreement with the model hindcast.

  18. Trends and low-frequency variability of storminess over western Europe, 1878-2007

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaolan L.; Wan, Hui; Zwiers, Francis W.; Swail, Val R. [Environment Canada, Climate Research Division, Science and Technology Branch, Toronto, ON (Canada); Compo, Gilbert P. [University of Colorado, CIRES, Climate Diagnostics Center, Boulder, CO (United States); Physical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO (United States); Allan, Robert J. [Met Office, Hadley Centre, Exeter (United Kingdom); Vose, Russell S. [NOAA' s National Climatic Data Center, Asheville, NC (United States); Jourdain, Sylvie [Direction de la Climatologie, Meteo-France, Toulouse (France); Yin, Xungang [STG Inc., Asheville, NC (United States)

    2011-12-15

    This study analyzes extremes of geostrophic wind speeds derived from sub-daily surface pressure observations at 13 sites in the European region from the Iberian peninsula to Scandinavia for the period from 1878 or later to 2007. It extends previous studies on storminess conditions in the Northeast (NE) Atlantic-European region. It also briefly discusses the relationship between storminess and the North Atlantic Oscillation (NAO). The results show that storminess conditions in the region from the Northeast Atlantic to western Europe have undergone substantial decadal or longer time scale fluctuations, with considerable seasonal and regional differences (especially between winter and summer, and between the British Isles-North Sea area and other parts of the region). In the North Sea and the Alps areas, there has been a notable increase in the occurrence frequency of strong geostrophic winds from the mid to the late twentieth century. The results also show that, in the cold season (December-March), the NAO-storminess relationship is significantly positive in the north-central part of this region, but negative in the south-southeastern part. (orig.)

  19. Airborne pollen trends in the Iberian Peninsula.

    Science.gov (United States)

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Effect of WO{sub x} on Co and Ni/Hydrotalcite catalysts to obtain hydrogen from bioethanol; Efecto del WO{sub x} sobre catalizadores de Co, Ni/hidrotalcita para obtener hidrogeno a partir de bioetanol

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, M.A.; Contreras, J. L. [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D.F. (Mexico)]. E-mail: jlcl@correo.azc.uam.mx; Fuentes, G.A. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D.F. (Mexico); Luna, R. [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D.F. (Mexico); Salmones, J.; Zeifert, B. [ESIQIE, Instituto Politecnico Nacional, Mexico, D.F. (Mexico)] Vazquez, A. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2009-09-15

    This work studies the effect of tungsten oxides on the synthesis, characterization and reaction of Co catalysts, Ni exchanges in hydrotalcite, to produce H{sub 2} from ethanol. The catalysts were characterized by BET area, x-ray diffraction and Raman, Infrared and UV-vis spectroscopies. The catalytic evaluation was performed with micro-reaction equipment using a water/ethanol ratio of 4 at 450 degrees Celsius. The effect of the W contents was from 0.5 to 3%. X-ray diffraction of the Co and Ni series showed a continuous decrease in crystallinity as W contents increased. Other findings include a pore morphology in the form of parallel plates and a mesoporous distribution (bimodal) with areas of 150-250 m{sup 2}/g. Infrared OH vibrations found, H{sub 2}O, Al-OH, Mg-and CO32-OH, also a low intensity peak related to vibration of type W = O. For Raman found links the W-O-W. UV-vis a band was found in the ultraviolet region, which in the case of the series of cobalt decreases as the content of W. The opposite occurred for the series of Ni. W was observed that promotes the conversion of Co in the range up to 80% while not promoted in the case of Ni. W showed that promotes catalyst stability (after 430 min), Co series showed a conversion of 80% and reached 90% Ni, no catalyst was deactivated before 350 min. [Spanish] En este trabajo se estudia el efecto de los oxidos de tungsteno en la sintesis, caracterizacion y reaccion de catalizadores de Co, Ni intercambiados en hidrotalcita, para la produccion de H{sub 2} a partir de etanol. Los catalizadores se caracterizaron por area BET, difraccion de rayos X, espectroscopias: Raman, Infrarrojo y UV-vis. La evaluacion catalitica se llevo a cabo en un equipo de microrreaccion usando una relacion agua/etanol de 4 a 450 grados centigrados se estudio el efecto del contenido de W desde 0.5 hasta 3%. La difraccion de rayos X para las series de Co y Ni mostro una disminucion continua de la cristalinidad conforme aumento el contenido de W

  1. Climate Prediction Center

    Science.gov (United States)

    Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Home Site Map News Organization Enter Search Term(s): Search Search the CPC Go NCEP Quarterly Newsletter Climate Highlights U.S Climate-Weather El Niño/La Niña MJO Blocking AAO, AO, NAO, PNA Climatology Global Monsoons Expert

  2. Destruction of organochlorated compounds and CFCs by catalytic hydrodechloration; Destruccion de compuestos organoclorados y CFCs mediante hidrodecloracion catalitica

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez Garcia, S.; Sastre Andres, H.; Diez Sanz, F. V.

    1998-12-01

    The destruction of organohalogenated compounds ( for example chlorinated solvents, PCBs and CFCs) is a very serious environmental problems. Catalytic hydrodechlorination has shown to be potentially efficient method for the destruction of these compounds. In this technique the halogenated compound reacts with hydrogen, tielding a non-chlorinated compound (environmentally harmless) and hydrogen-chloride. In this article, different set-ups and catalysts employed in the catalytic hydrogechlorination were described. Finally, some applications of this technique to the treatment of industrial effluents, such as the destruction of chlorinated solvents (as trichloroethylene o tetrachloromethane), conversion of CFCs into HCFCs, destruction of PCBs and treatment of water polluted with chlorinated pesticides. (Author) 28 refs.

  3. Iron ore catalysts for methane decomposition to make CO x free hydrogen and carbon nano material

    KAUST Repository

    Zhou, Lu; Enakonda, Linga Reddy; Li, Sheng; Gary, Daniel; Del-Gallo, Pascal; Mennemann, Christina; Basset, Jean-Marie

    2018-01-01

    In this work, for the first time, iron ores with 91.7%–96.2% FeO, 1.3%–2.3% AlO, 1.2%–4.5% SiO, 1.3%–3.9% NaO, were studied directly as bulk catalysts for methane decomposition. By hydrogen pre-reduction at 850 °C, FeO species on iron ores were

  4. Climate Prediction Center - Global Tropical Hazards Assessment

    Science.gov (United States)

    Weather Service NWS logo - Click to go to the NWS home page Climate Prediction Center Home Site Map News Organization Search Go Search the CPC Go Climate Outlooks Climate & Weather Link El Niño/La Niña MJO Teleconnections AO NAO PNA AAO Blocking Storm Tracks Climate Glossary Outreach About Us Our Mission Who We Are

  5. The microbiology of alkaline-fermentation of indigenous seeds used as food condiments in Africa and Asia

    DEFF Research Database (Denmark)

    Parkouda, Charles; Nielsen, Dennis Sandris; Azokpota, Paulin

    2009-01-01

    . Studies have been undertaken which have investigated a number of these products like dawadawa, ugba, bikalga, kinema, natto, and thua-nao. In this review, current knowledge about the principal microbiological activities and biochemical modifications which occur during the processing of the alkaline...... for the selection of potential starter cultures for controlled and better production procedures for alkaline-fermented seeds condiments....

  6. Can children take advantage of nao gaze-based hints during gameplay?

    NARCIS (Netherlands)

    Mwangi, E.N.; Diaz, M.; Barakova, E.I.; Catala, A.; Rauterberg, G.W.M.

    2017-01-01

    This paper presents a study that analyzes the effects of robots' gaze hints on children's performance in a card-matching game. We conducted a within-subjects study, in which children played a card matching game "Memory" in the presence of a robot tutor in two sessions. In one session, the robot gave

  7. A prospective study with children whose mothers had dengue during pregnancy Estudo prospectivo com lactentes cujas mães tiveram dengue durante a gravidez

    Directory of Open Access Journals (Sweden)

    Luiz Tadeu Moraes Figueiredo

    1994-10-01

    Full Text Available Dengue congenital disease was not confirmed in 10 children whose mothers had the infection during pregnancy. The fetal sera presented anti-dengue IgG antibodies which progressively declined, and disappeared after 8 months. IgM antibodies to dengue were not observed in the sera. Other normal data suggesting the healthy state of the children included: absence of malformations, pregnancy time, Apgar index, weight, and placenta aspectNum estudo sobre doença congênita, com 10 lactentes de mães que tiveram dengue na gravidez, nao se detectou infecção intra-uterina. Os soros fetais apresentaram anticorpos IgG contra dengue tipo 1, por teste imuno-enzimático, provavelmente transferidos passivamente. Estes anticorpos, analisados de forma prospectiva em 8 casos, foram declinando progressivamente, até desaparecerem, aos 8 meses de idade. Anticorpos do tipo IgM contra dengue nao foram detectados. O tempo gestacional normal, os índices de Apgar, o peso e as placentas normais dos neonatos, bem como a ausência de malformações, foram evidências contrárias à infecção intra-uterina.

  8. A Novel Sensory Mapping Design for Bipedal Walking on a Sloped Surface

    Directory of Open Access Journals (Sweden)

    Chiao-Min Wu

    2012-10-01

    Full Text Available This paper presents an environment recognition method for bipedal robots using a time-delay neural network. For a robot to walk in a varying terrain, it is desirable that the robot can adapt to any environment encountered in real-time. This paper aims to develop a sensory mapping unit to recognize environment types from the input sensory data based on an artificial neural network approach. With the proposed sensory mapping design, a bipedal walking robot can obtain real-time environment information and select an appropriate walking pattern accordingly. Due to the time-dependent property of sensory data, the sensory mapping is realized by using a time-delay neural network. The sensory data of earlier time sequences combined with current sensory data are sent to the neural network. The proposed method has been implemented on the humanoid robot NAO for verification. Several interesting experiments were carried out to verify the effectiveness of the sensory mapping design. The mapping design is validated for the uphill, downhill and flat surface cases, where three types of environment can be recognized by the NAO robot online.

  9. Modelling and forecasting long-term dynamics of Western Baltic macrobenthic fauna in relation to climate signals and environmental change

    Science.gov (United States)

    Gröger, Joachim; Rumohr, Heye

    2006-05-01

    Long-term macrobenthos data from Kiel Bight in the Western Baltic collected between 1968 and 2000 have been correlated with the winter NAO index (North Atlantic Oscillation Index) and other environmental data such as temperature, salinity and oxygen content in the bottom water in order to detect systematic patterns related to so far unexplained abiotic signals in the dynamics of zoobenthic species assemblages. The benthos data come from a cluster of five stations (Süderfahrt/ Millionenviertel) in Kiel Bay. Our investigations concentrated on the macrobenthic dynamics with a focus on the number of species m - 2 (species richness). Using logarithms and the time series analysis approach of Box/Jenkins (ARIMA modelling, transfer function modelling) it was shown that species richness was strongly influenced by the winter NAO (adjusted for a linear time trend within the 1968-2000 period) and salinity (with a shift/lag of four years). Bootstrapping experiments (i.e. sampling from the error process) and analysis of prediction power (by means of the one- or more-years leaving-out method) showed that the parameter estimates behaved in a stable way, leading to a relatively robust model.

  10. Climate-induced signatures in the zooplankton communities: a meta-analysis at a European scale.

    Directory of Open Access Journals (Sweden)

    Sónia Cotrim Marques

    2014-05-01

    Full Text Available Several recent studies have revealed the impacts of the climate variability in the dynamic of zooplankton in different estuarine ecosystems, imposing a need for more and continued global studies. Presently, there is a growing appreciation in international collaborations to compare and contrast estuarine ecosystem response to climate variability across geographical gradients, including long-term changes in zooplankton. We performed a meta-analysis comprising field data from 7 location (Mondego estuary-Portugal, Seine estuary- France, Sheldt estuary- Belgium, Kiel fjord - Germany, Gulf of Riga- Latvia, Gulf of Bothnia – Sweden and Finland Archipelagos. The use of climatic modes (e.g. NAO, ENSO has proven useful in investigating links between climatic variations and ecological patterns. Therefore, the main focus will be to test the influence of the NAO on abundance of organisms, key species, local environment and whether these relationships are generally positive, whether they are sensitive to methodological differences among studies, between taxonomic group and key species. The knowledge gained will contribute to quantitatively evaluate the multi-scale structure of climate and marine environment and to identify a set of environmental indicators to assess the estuarine ecosystem state and risks for ecological shifts.

  11. Dendrite-Free Sodium-Metal Anodes for High-Energy Sodium-Metal Batteries.

    Science.gov (United States)

    Sun, Bing; Li, Peng; Zhang, Jinqiang; Wang, Dan; Munroe, Paul; Wang, Chengyin; Notten, Peter H L; Wang, Guoxiu

    2018-05-31

    Sodium (Na) metal is one of the most promising electrode materials for next-generation low-cost rechargeable batteries. However, the challenges caused by dendrite growth on Na metal anodes restrict practical applications of rechargeable Na metal batteries. Herein, a nitrogen and sulfur co-doped carbon nanotube (NSCNT) paper is used as the interlayer to control Na nucleation behavior and suppress the Na dendrite growth. The N- and S-containing functional groups on the carbon nanotubes induce the NSCNTs to be highly "sodiophilic," which can guide the initial Na nucleation and direct Na to distribute uniformly on the NSCNT paper. As a result, the Na-metal-based anode (Na/NSCNT anode) exhibits a dendrite-free morphology during repeated Na plating and striping and excellent cycling stability. As a proof of concept, it is also demonstrated that the electrochemical performance of sodium-oxygen (Na-O 2 ) batteries using the Na/NSCNT anodes show significantly improved cycling performances compared with Na-O 2 batteries with bare Na metal anodes. This work opens a new avenue for the development of next-generation high-energy-density sodium-metal batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Utilização de Softwares no processo de ensino e aprendizagem de instrumentos de teclado

    Directory of Open Access Journals (Sweden)

    Susana Ester Krüger

    2015-05-01

    Full Text Available Neste trabalho são analisadas algumas pesquisas realizadas sobre software utilizados no processo de ensino e aprendizagem de insrtumentos de teclado. São investigadas as interseções efetuadas em pesquisas quanto as concepções educativas, instrumentos de teclado e uso de software. As pesquisas quanto as concepções educativas, intrumentos de teclado e uso de software. As pesquisas são analisadas de acordo com a forma de atuação do software no processo de ensino e aprendizagem de instrumentos de teclado? Indireta e direta. Constata-se que a utilizaçnao de software pode ser propicia ao desenvolvimento musical de estudante de instrumentos de teclado. São apontadas algumas deficiências e possibilidades do uso de softwares no processo educacional. Por fim, ressalta-se a necessidade e importância de participação dos professores na elaboração dos mesmos, utilizaçnao de concepções educativas no seu processo de criação, de sua avaliação prévia e, de realização de pesquisas mais extensas sobre tema.

  13. Long-Range Forecasting in Support of Operations in Pakistan

    Science.gov (United States)

    2011-03-01

    station in the southwestern part of the Iberian Peninsula (Hurrell 2006). NOAA’s ESRL uses the former method to construct an NAO index (NAOI), and we...mission planning for both military and nonmilitary operations. This is especially true for countries that are susceptible to persistent climate ...variations, such as Pakistan. The environmental, economic, and political impacts of climate variations can be severe—particularly for countries that are

  14. Severe Weather Guide Mediterranean Ports - 33. Tangier

    Science.gov (United States)

    1990-11-01

    building tctt, eas. : .u’.d r.i f on l’ues. b. North to northwest wrrds usually accompany cold frontal passages. .2 or vato :an rayoe Strongest fronts...principal A-S-Nao2.s A. , 0 Rue Du Clateii-Lor, B.P. 426 irect-or, Tec!!. Info~at-,cn A-aPo11 x 292075 - Brost Cadex, Franc. Defense Adv. Rach. projects

  15. Advanced Aeroservoelastic Testing and Data Analysis (Les Essais Aeroservoelastiques et l’Analyse des Donnees).

    Science.gov (United States)

    1995-11-01

    050000000K441N:7 CONF: 1 CONO : 30 L) 0E q:no0 -- 0ID 500 WO AIRSPEED IKEAS ) j_____-AIRSPEED (KEAS) $010001000000 NAO): 12 50007m000 MACH No 1 ý2 0077:1,3 CON; 7...3o c 3 ’- 0 - 2n Ŗ 137 .I.......... . . ...... . ....... AIRSPEED IKEAS ) AIRSPEED (KEAS) Figure 7: Autodata Monitor and Trends Screen Layout 18-11

  16. Extended-Range Prediction with Low-Dimensional, Stochastic-Dynamic Models: A Data-driven Approach

    Science.gov (United States)

    2013-09-30

    statistically extratropical storms and extremes, and link these to LFV modes. Mingfang Ting, Yochanan Kushnir, Andrew W. Robertson, Lei Wang...forecast models, as well as in the understanding they have generated. Adam Sobel, Daehyun Kim and Shuguang Wang. Extratropical variability and...predictability. Determine the extent to which extratropical monthly and seasonal low-frequency variability (LFV, i.e. PNA, NAO, as well as other regional

  17. Winter climate and plant productivity predict abundances of small herbivores in central Europe

    Czech Academy of Sciences Publication Activity Database

    Tkadlec, Emil; Zbořil, J.; Losík, J.; Gregor, P.; Lisická, L.

    2006-01-01

    Roč. 32, č. 2 (2006), s. 99-108 ISSN 0936-577X R&D Projects: GA ČR GA206/04/2003 Institutional research plan: CEZ:AV0Z60930519 Keywords : climate effects * common vole * European hare * NAO * plant productivity * crop yield Subject RIV: EH - Ecology, Behaviour Impact factor: 1.519, year: 2006 http://www.int-res.com/articles/cr_oa/c032p099.pdf

  18. Main determinants of rodent population fluctuations in managed Central European temperate lowland forests

    Czech Academy of Sciences Publication Activity Database

    Šipoš, J.; Suchomel, J.; Purchart, L.; Kindlmann, Pavel

    2017-01-01

    Roč. 62, č. 3 (2017), s. 283-295 ISSN 2199-2401 R&D Projects: GA MŠk(CZ) LO1415; GA ČR GB14-36098G Institutional support: RVO:67179843 Keywords : Intraspecific competition * Mast year * Acorns * Phenotypic characteristics * Small mammals * NAO index Subject RIV: EH - Ecology, Behaviour OBOR OECD: Environmental sciences (social aspects to be 5.7) Impact factor: 1.068, year: 2016

  19. The impact of gyre dynamics on the mid-depth salinity signature of the eastern North Atlantic

    Science.gov (United States)

    Burkholder, K. C.; Lozier, M. S.

    2009-04-01

    The Mediterranean Overflow Water (MOW) is widely recognized for its role in establishing the mid-depth salinity signature of the subtropical North Atlantic. However, recent work has revealed an intermittent impact of MOW on the salinity signature of the eastern subpolar basin. This impact results from a temporally variable penetration of the northward flowing branch of the MOW past Porcupine Bank into the eastern subpolar basin. It has been shown that the salinity signature of the eastern subpolar basin, in particular the Rockall Trough, varies with the state of the North Atlantic Oscillation (NAO): during persistent periods of strong winds (high NAO index), when the subpolar front moves eastward, waters in the subpolar gyre block the northward flowing MOW, preventing its entry into the subpolar gyre. Conversely, during persistent periods of weak winds (low NAO index), the front moves westward, allowing MOW to penetrate north of Porcupine Bank and into the subpolar gyre. Here, we investigate the manner in which the spatial and temporal variability in the northward penetration of the MOW and the position of the eastern limb of the subpolar front affect the mid-depth property fields not only in the subpolar gyre, but in the subtropical gyre as well. Using approximately 55 years of historical hydrographic data and output from the 1/12° FLAME model, we analyze the temporal variability of salinity along the eastern boundary and compare this variability to the position of the subpolar front in both the observational record and the FLAME model. We conclude that when the zonal position of the subpolar front moves relatively far offshore and the MOW is able to penetrate to the north, high salinity anomalies are observed at high latitudes and low salinity anomalies are observed at low latitudes. Conversely, when the frontal position shifts to the east, the MOW (and thus, the high salinity signature) is blocked, resulting in a drop in salinity anomalies at high latitudes

  20. The subpolar North Atlantic - Response to North Atlantic oscillation like forcing and Influence on the Atlantic meridional overturning circulation

    Science.gov (United States)

    Lohmann, Katja; Drange, Helge; Jungclaus, Johann

    2010-05-01

    The extent and strength of the North Atlantic subpolar gyre (SPG) changed rapidly in the mid-1990s, going from large and strong in 1995 to substantially weakened in the following years. The abrupt change in the intensity of the SPG is commonly linked to the reversal of the North Atlantic Oscillation (NAO) index, changing from strong positive to negative values, in the winter 1995/96. In this study we investigate the impact of the initial SPG state on its subsequent behavior by means of an ocean general circulation model driven by NCEP-NCAR reanalysis fields. Our sensitivity integrations suggest that the weakening of the SPG cannot be explained by the change in the atmospheric forcing alone. Rather, for the time period around 1995, the SPG was about to weaken, irrespective of the actual atmospheric forcing, due to the ocean state governed by the persistently strong positive NAO during the preceding seven years (1989 to 1995). Our analysis indicates that it was this preconditioning of the ocean, in combination with the sudden drop in the NAO in 1995/96, that lead to the strong and rapid weakening of the SPG in the second half of the 1990s. In the second part, the sensitivity of the low-frequency variability of the Atlantic meridional overturning circulation to changes in the subpolar North Atlantic is investigated using a 2000 year long control integration as well as sensitivity experiments with the MPI-M Earth System Model. Two 1000 year long sensitivity experiments will be performed, in which the low-frequency variability in the overflow transports from the Nordic Seas and in the subpolar deep water formation rates is suppressed respectively. This is achieved by nudging temperature and salinity in the GIN Sea or in the subpolar North Atlantic (up to about 1500m depth) towards a monthly climatology obtained from the last 1000 years of the control integration.

  1. Editorial

    Science.gov (United States)

    Gouirand, I.; Moron, V.

    2003-11-01

    Sea-level pressure (SLP) anomalies over the North Atlantic and European (NAE) sector (25-70°N, 100°W-50°E) and over a larger domain encompassing the entire North Pacific domain are studied to demonstrate that SLP anomalies (SLPAs) during boreal winter (January-March) vary widely between years characterized by the same El Niño-southern oscillation (ENSO) phase. The typical cold ENSO signal tends to be more stable than the warm one during the 1874-1996 period. The typical cold ENSO pattern (e.g. positive SLPA south of 55°N across the North Atlantic and negative SLPA in the northern North Atlantic) is similar to the positive phase of the North Atlantic oscillation (NAO) and occurs throughout the 20th century, except during the 1950s and 1960s when the basinwide westerlies are particularly slow. On the contrary, the typical warm ENSO pattern (e.g. positive SLPA from central Canada to Scandinavia and negative SLPA from the southeastern USA to central Europe, corresponding to the negative phase of the NAO) occurs mainly from 1930 to 1970. Another robust warm ENSO pattern is associated with a large positive (negative) SLPA between Newfoundland and western Europe (between Greenland and Scandinavia), and occurs mainly at the beginning and the end of the 20th century when the basinwide North Atlantic westerlies are strengthened. All these patterns stay statistically significant when the multi-decadal variability is removed from the North Atlantic SLPA. It is shown that the low-frequency variability of the north tropical Atlantic sea-surface temperature anomalies could exert a modulating effect on the ENSO teleconnection. NAE SLPAs tend to be strong during warm (cold) ENSO winters and consistent with a negative (positive) phase of the NAO when the north tropical Atlantic is anomalously warm (cold). Lastly, the magnitude of the SLPA patterns over the NAE sector appears poorly related to the intensity of sea-surface temperature anomalies in the central and eastern

  2. Influence of Climate Change and Trophic Coupling across Four Trophic Levels in the Celtic Sea

    Science.gov (United States)

    Lauria, Valentina; Attrill, Martin J.; Pinnegar, John K.; Brown, Andrew; Edwards, Martin; Votier, Stephen C.

    2012-01-01

    Climate change has had profound effects upon marine ecosystems, impacting across all trophic levels from plankton to apex predators. Determining the impacts of climate change on marine ecosystems requires understanding the direct effects on all trophic levels as well as indirect effects mediated by trophic coupling. The aim of this study was to investigate the effects of climate change on the pelagic food web in the Celtic Sea, a productive shelf region in the Northeast Atlantic. Using long-term data, we examined possible direct and indirect ‘bottom-up’ climate effects across four trophic levels: phytoplankton, zooplankton, mid-trophic level fish and seabirds. During the period 1986–2007, although there was no temporal trend in the North Atlantic Oscillation index (NAO), the decadal mean Sea Surface Temperature (SST) in the Celtic Sea increased by 0.66±0.02°C. Despite this, there was only a weak signal of climate change in the Celtic Sea food web. Changes in plankton community structure were found, however this was not related to SST or NAO. A negative relationship occurred between herring abundance (0- and 1-group) and spring SST (0-group: p = 0.02, slope = −0.305±0.125; 1-group: p = 0.04, slope = −0.410±0.193). Seabird demographics showed complex species–specific responses. There was evidence of direct effects of spring NAO (on black-legged kittiwake population growth rate: p = 0.03, slope = 0.0314±0.014) as well as indirect bottom-up effects of lagged spring SST (on razorbill breeding success: p = 0.01, slope = −0.144±0.05). Negative relationships between breeding success and population growth rate of razorbills and common guillemots may be explained by interactions between mid-trophic level fish. Our findings show that the impacts of climate change on the Celtic Sea ecosystem is not as marked as in nearby regions (e.g. the North Sea), emphasizing the need for more research at regional scales. PMID:23091621

  3. Influence of climate change and trophic coupling across four trophic levels in the Celtic Sea.

    Directory of Open Access Journals (Sweden)

    Valentina Lauria

    Full Text Available Climate change has had profound effects upon marine ecosystems, impacting across all trophic levels from plankton to apex predators. Determining the impacts of climate change on marine ecosystems requires understanding the direct effects on all trophic levels as well as indirect effects mediated by trophic coupling. The aim of this study was to investigate the effects of climate change on the pelagic food web in the Celtic Sea, a productive shelf region in the Northeast Atlantic. Using long-term data, we examined possible direct and indirect 'bottom-up' climate effects across four trophic levels: phytoplankton, zooplankton, mid-trophic level fish and seabirds. During the period 1986-2007, although there was no temporal trend in the North Atlantic Oscillation index (NAO, the decadal mean Sea Surface Temperature (SST in the Celtic Sea increased by 0.66 ± 0.02 °C. Despite this, there was only a weak signal of climate change in the Celtic Sea food web. Changes in plankton community structure were found, however this was not related to SST or NAO. A negative relationship occurred between herring abundance (0- and 1-group and spring SST (0-group: p = 0.02, slope = -0.305 ± 0.125; 1-group: p = 0.04, slope = -0.410 ± 0.193. Seabird demographics showed complex species-specific responses. There was evidence of direct effects of spring NAO (on black-legged kittiwake population growth rate: p = 0.03, slope = 0.0314 ± 0.014 as well as indirect bottom-up effects of lagged spring SST (on razorbill breeding success: p = 0.01, slope = -0.144 ± 0.05. Negative relationships between breeding success and population growth rate of razorbills and common guillemots may be explained by interactions between mid-trophic level fish. Our findings show that the impacts of climate change on the Celtic Sea ecosystem is not as marked as in nearby regions (e.g. the North Sea, emphasizing the need for more research at regional scales.

  4. Marine mammal strandings and environmental changes: a 15-year study in the St. Lawrence ecosystem.

    Directory of Open Access Journals (Sweden)

    Marie-Hélène Truchon

    Full Text Available Understanding the effects of climatic variability on marine mammals is challenging due to the complexity of ecological interactions. We used general linear models to analyze a 15-year database documenting marine mammal strandings (1994-2008; n = 1,193 and nine environmental parameters known to affect marine mammal survival, from regional (sea ice to continental scales (North Atlantic Oscillation, NAO. Stranding events were more frequent during summer and fall than other seasons, and have increased since 1994. Poor ice conditions observed during the same period may have affected marine mammals either directly, by modulating the availability of habitat for feeding and breeding activities, or indirectly, through changes in water conditions and marine productivity (krill abundance. For most species (75%, n = 6 species, a low volume of ice was correlated with increasing frequency of stranding events (e.g. R(2adj = 0.59, hooded seal, Cystophora cristata. This likely led to an increase in seal mortality during the breeding period, but also to increase habitat availability for seasonal migratory cetaceans using ice-free areas during winter. We also detected a high frequency of stranding events for mysticete species (minke whale, Balaenoptera acutorostrata and resident species (beluga, Delphinapterus leucas, correlated with low krill abundance since 1994. Positive NAO indices were positively correlated with high frequencies of stranding events for resident and seasonal migratory cetaceans, as well as rare species (R(2adj = 0.53, 0.81 and 0.34, respectively. This contrasts with seal mass stranding numbers, which were negatively correlated with a positive NAO index. In addition, an unusual multiple species mortality event (n = 114, 62% of total annual mortality in 2008 was caused by a harmful algal bloom. Our findings provide an empirical baseline in understanding marine mammal survival when faced with climatic variability. This is a

  5. Scalp and Body Acupuncture for Treatment of Senile Insomnia-A Report of 83 Cases

    Institute of Scientific and Technical Information of China (English)

    卢泽强

    2002-01-01

    @@ The author has in recent years treated 83 cases of senile insomnia with scalp and body acupuncture. Meanwhile, 35 cases in the control group were treated with western and Chinese drugs. The therapeutic results in the treatment group were superior to that of nitrazapam and An Shen Bu Nao Ye (安神补脑液Sedative and Brain-invigorating Fluid) used in the control group. A report of the treatment follows.

  6. Reactive scattering of electronically excited alkali atoms with molecules

    International Nuclear Information System (INIS)

    Mestdagh, J.M.; Balko, B.A.; Covinsky, M.H.; Weiss, P.S.; Vernon, M.F.; Schmidt, H.; Lee, Y.T.

    1987-06-01

    Representative families of excited alkali atom reactions have been studied using a crossed beam apparatus. For those alkali-molecule systems in which reactions are also known for ground state alkali and involve an early electron transfer step, no large differences are observed in the reactivity as Na is excited. More interesting are the reactions with hydrogen halides (HCl): it was found that adding electronic energy into Na changes the reaction mechanism. Early electron transfer is responsible of Na(5S, 4D) reactions, but not of Na(3P) reactions. Moreover, the NaCl product scattering is dominated by the HCl - repulsion in Na(5S, 4D) reactions, and by the NaCl-H repulsion in the case of Na(3P). The reaction of Na with O 2 is of particular interest since it was found to be state specific. Only Na(4D) reacts, and the reaction requires restrictive constraints on the impact parameter and the reactants' relative orientation. The reaction with NO 2 is even more complex since Na(4D) leads to the formation of NaO by two different pathways. It must be mentioned however, that the identification of NaO as product in these reactions has yet to be confirmed

  7. Solar and atmospheric forcing on mountain lakes.

    Science.gov (United States)

    Luoto, Tomi P; Nevalainen, Liisa

    2016-10-01

    We investigated the influence of long-term external forcing on aquatic communities in Alpine lakes. Fossil microcrustacean (Cladocera) and macrobenthos (Chironomidae) community variability in four Austrian high-altitude lakes, determined as ultra-sensitive to climate change, were compared against records of air temperature, North Atlantic Oscillation (NAO) and solar forcing over the past ~400years. Summer temperature variability affected both aquatic invertebrate groups in all study sites. The influence of NAO and solar forcing on aquatic invertebrates was also significant in the lakes except in the less transparent lake known to have remained uniformly cold during the past centuries due to summertime snowmelt input. The results suggest that external forcing plays an important role in these pristine ecosystems through their impacts on limnology of the lakes. Not only does the air temperature variability influence the communities but also larger-scale external factors related to atmospheric circulation patterns and solar activity cause long-term changes in high-altitude aquatic ecosystems, through their connections to hydroclimatic conditions and light environment. These findings are important in the assessment of climate change impacts on aquatic ecosystems and in greater understanding of the consequences of external forcing on lake ontogeny. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Extreme events in total ozone over the Northern mid-latitudes: an analysis based on long-term data sets from five European ground-based stations

    Energy Technology Data Exchange (ETDEWEB)

    Rieder, Harald E. (Inst. for Atmospheric and Climate Science, ETH Zurich, Zurich (Switzerland)), e-mail: hr2302@columbia.edu; Jancso, Leonhardt M. (Inst. for Atmospheric and Climate Science, ETH Zurich, Zurich (Switzerland); Inst. for Meteorology and Geophysics, Univ. of Innsbruck, Innsbruck (Austria)); Di Rocco, Stefania (Inst. for Atmospheric and Climate Science, ETH Zurich, Zurich (Switzerland); Dept. of Geography, Univ. of Zurich, Zurich (Switzerland)) (and others)

    2011-11-15

    We apply methods from extreme value theory to identify extreme events in high (termed EHOs) and low (termed ELOs) total ozone and to describe the distribution tails (i.e. very high and very low values) of five long-term European ground-based total ozone time series. The influence of these extreme events on observed mean values, long-term trends and changes is analysed. The results show a decrease in EHOs and an increase in ELOs during the last decades, and establish that the observed downward trend in column ozone during the 1970-1990s is strongly dominated by changes in the frequency of extreme events. Furthermore, it is shown that clear 'fingerprints' of atmospheric dynamics (NAO, ENSO) and chemistry [ozone depleting substances (ODSs), polar vortex ozone loss] can be found in the frequency distribution of ozone extremes, even if no attribution is possible from standard metrics (e.g. annual mean values). The analysis complements earlier analysis for the world's longest total ozone record at Arosa, Switzerland, confirming and revealing the strong influence of atmospheric dynamics on observed ozone changes. The results provide clear evidence that in addition to ODS, volcanic eruptions and strong/moderate ENSO and NAO events had significant influence on column ozone in the European sector

  9. Determination of Proper Motions of Circumpolar Stars by Using Images from Ukrvo Plate Archives

    Science.gov (United States)

    Protsyuk, Yu.; Andruk, V.; Mazhaev, A.; Kovylianska, O.; Protsyuk, S.; Golovnya, V.

    UkrVO plate archives contain informationobtained at different time periods and in different observatories for the same regions of the sky [3, 5, 6, 7, 8]. It allows us to carry out joint processing of plates and to receive new results for interesting objects. To obtain proper motions of stars in circumpolar areas, we selected 34 photographic plates from the RI NAO archive and 161 plates from the archive of the MAO NAS. A mean epoch difference between the plates from these archives is 55 years. Scanning of the plates and data processing were independently carried out by both observatories. A catalog of equatorial positions for 195 thousand stars up to 15m was compiled in the RI NAO (black dots in Fig. 1). A catalog of equatorial positions for 1050 thousand stars up to 16.5m was compiled in MAO (gray dots in Fig. 1). A comparison of positions for common stars contained in these catalogs was conducted. A catalog of proper motions for 30 thousand common stars up to 15m was compiled using these two input catalogs. The obtained result suggests the advisability of processing of all observations to receive proper motions of stars up to 14-15m in the declination zone of 65° to 90°.

  10. Detrital events and hydroclimate variability in the Romanian Carpathians during the mid-to-late Holocene

    Science.gov (United States)

    Longman, Jack; Ersek, Vasile; Veres, Daniel; Salzmann, Ulrich

    2017-07-01

    The Romanian Carpathians are located at the confluence of three major atmospheric pressure fields: the North Atlantic, the Mediterranean and the Siberian. Despite its importance for understanding past human impact and climate change, high-resolution palaeoenvironmental reconstructions of Holocene hydroclimate variability, and in particular records of extreme precipitation events in the area, are rare. Here we present a 7500-year-long high-resolution record of past climatic change and human impact recorded in a peatbog from the Southern Carpathians, integrating palynological, geochemical and sedimentological proxies. Natural climate fluctuations appear to be dominant until 4500 years before present (yr BP), followed by increasing importance of human impact. Sedimentological and geochemical analyses document regular minerogenic deposition within the bog, linked to periods of high precipitation. Such minerogenic depositional events began 4000 yr BP, with increased depositional rates during the Medieval Warm Period (MWP), the Little Ice Age (LIA) and during periods of societal upheaval (e.g. the Roman conquest of Dacia). The timing of minerogenic events appears to indicate a teleconnection between major shifts in North Atlantic Oscillation (NAO) and hydroclimate variability in southeastern Europe, with increased minerogenic deposition correlating to low NAO index values. By linking the minerogenic deposition to precipitation variability, we state that this link persists throughout the mid-to-late Holocene.

  11. Capabilities of laser ablation mass spectrometry in the differentiation of natural and artificial opal gemstones.

    Science.gov (United States)

    Erel, Eric; Aubriet, Frédéric; Finqueneisel, Gisèle; Muller, Jean-François

    2003-12-01

    The potentialities of laser ablation coupled to ion cyclotron resonance Fourier transform mass spectrometry are evaluated to distinguish natural and artificial opals. The detection of specific species in both ion detection modes leads us to obtain relevant criteria of differentiation. In positive ions, species including hafnium and large amounts of zirconium atoms are found to be specific for artificial opal. In contrast, aluminum, titanium, iron, and rubidium are systematically detected in the study of natural opals. Moreover, some ions allow us to distinguish between natural opal from Australia and from Mexico. Australian gemstone includes specifically strontium, cesium, and barium. Moreover, it is also found that the yield of (H2O)0-1(SiO2)nX- (X- = O-, OH-, KO-, NaO-, SiO2-, AlO1-2-, FeO2-, ZrO2-, and ZrO3-) and (Al2O3)(SiO2)nAlO2- ions depends on the composition of the sample when opals are laser ablated. Ions, which include zirconium oxide species, are characteristics of artificial gem. In contrast, natural opals lead us, after laser ablation, to the production of ions including H2O, Al2O3 motifs and AlO-, KO-, NaO-, and FeO2- species.

  12. A novel way to detect correlations on multi-time scales, with temporal evolution and for multi-variables

    Science.gov (United States)

    Yuan, Naiming; Xoplaki, Elena; Zhu, Congwen; Luterbacher, Juerg

    2016-06-01

    In this paper, two new methods, Temporal evolution of Detrended Cross-Correlation Analysis (TDCCA) and Temporal evolution of Detrended Partial-Cross-Correlation Analysis (TDPCCA), are proposed by generalizing DCCA and DPCCA. Applying TDCCA/TDPCCA, it is possible to study correlations on multi-time scales and over different periods. To illustrate their properties, we used two climatological examples: i) Global Sea Level (GSL) versus North Atlantic Oscillation (NAO); and ii) Summer Rainfall over Yangtze River (SRYR) versus previous winter Pacific Decadal Oscillation (PDO). We find significant correlations between GSL and NAO on time scales of 60 to 140 years, but the correlations are non-significant between 1865-1875. As for SRYR and PDO, significant correlations are found on time scales of 30 to 35 years, but the correlations are more pronounced during the recent 30 years. By combining TDCCA/TDPCCA and DCCA/DPCCA, we proposed a new correlation-detection system, which compared to traditional methods, can objectively show how two time series are related (on which time scale, during which time period). These are important not only for diagnosis of complex system, but also for better designs of prediction models. Therefore, the new methods offer new opportunities for applications in natural sciences, such as ecology, economy, sociology and other research fields.

  13. Pulse combustors for unpulverized solid fuels; Combustor pulsante para solidos nao pulverizados

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Marco Aurelio; Carvalho Junior, Joao Andrade de [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

    1988-12-31

    This work presents results of performance evaluation of an experimental pulsating combustor developed to burn unpulverized solid fuels. The fuels tested were sized wood blocks and coal lumps. The results for coal show a clear maximum combustion efficiency as a function of fuel loading within the combustor. For an excess of air of 10%, a maximum combustion efficiency of 94% was obtained. (author) 38 refs., 10 figs., 2 tabs.

  14. Assessment of the physico-chemical properties of phases in the Na-U-Pu-O system

    International Nuclear Information System (INIS)

    Kleykamp, H.

    1990-05-01

    A critical review is given on the physico-chemical properties of phases in the Na-O, Na-U-O, Na-Pu-O and Na-U-Pu-O systems. This includes the phase diagrams as well as the crystallographic, mechanical, thermal, thermodynamic, transport, optical and chemical properties. This data is to be used for the modelling of the thermal, mechanical and chemical behaviour of defective LMFBR mixed oxide pins during and after reactor operation. (orig.) [de

  15. Analysis of Roanoke Region Weather Patterns Under Global Teleconnections

    OpenAIRE

    LaRocque, Eric John

    2006-01-01

    This work attempts to relate global teleconnections, through physical phenomena such as the El Nino-Southern Oscillation (ENSO), Artic Oscillation (AO), North Atlantic Oscillation (NAO), and the Pacific North American (PNA) pattern to synoptic-scale weather patterns and precipitation in the Roanoke, Virginia region. The first chapter describes the behavior of the El Nino-Southern Oscillation (ENSO) by implementing non-homogeneous and homogeneous Markov Chain models on a monthly time series o...

  16. Sedimentary processes on the NW Iberian Continental Shelf since the Little Ice Age

    Science.gov (United States)

    Martins, Virgínia; Figueira, Rubens Cesar Lopes; França, Elvis Joacir; Ferreira, Paulo Alves de Lima; Martins, Paula; Santos, José Francisco; Dias, João Alveirinho; Laut, Lazaro L. M.; Monge Soares, António M.; Silva, Eduardo Ferreira da; Rocha, Fernando

    2012-05-01

    The OMEX core CD110 W90, retrieved from the Douro Mud Patch (DMP) off the River Douro in the north of Portugal, records the period since the beginning of Little Ice Age (LIA). The core chronology is based upon the data attributes for 210Pb, 137Cs and a 14C dating from a level near the core base. Geochemical, granulometric, microfaunal (benthic foraminifera) and compositional data suggest the occurrence of precipitation changes which may have been, at least partially, influenced by the North Atlantic Oscillation (NAO), that contributes to the regulation of the ocean-atmosphere dynamics in the North Atlantic. Southwesterly Atlantic storm track is associated with the negative phases of the NAO, when the Azores High is anomalously weak, higher oceanographic hydrodynamism, downwelling events and increased rainfall generally occurs. Prevalence of these characteristics during the LIA left a record that corresponds to phases of major floods. During these phases the DMP received a higher contribution of relatively coarse-grained terrigenous sediments, enriched in quartz particles, which diluted the contribution of other minerals, as indicated by reduced concentrations of several lithogenic chemical elements such as: Al, As, Ba, Ce, Co, Cu, Fe, K, La, Li, Mg, Mn, Mo, Na, Ni, P, Rb, Sc, Sn, Th, V and Y. The presence of biogenic carbonate particles also underwent dilution, as revealed by the smaller abundance of foraminifera and correlative lower concentrations of Ca and Sr. During this period, the DMP also received an increased contribution of organic matter, indicated by higher values of lignin remains and a benthic foraminifera high productivity index, or BFHP, which gave rise to early diagenetic changes with pyrite formation. Since the beginning of the 20th century this contribution diminished, probably due to several drier periods and the impact of human activities in the river basins, e.g. construction of dams, or, on the littoral areas, construction of hard

  17. Twentieth-century atmospheric river activity along the west coasts of Europe and North America: algorithm formulation, reanalysis uncertainty and links to atmospheric circulation patterns

    Science.gov (United States)

    Brands, S.; Gutiérrez, J. M.; San-Martín, D.

    2017-05-01

    A new atmospheric-river detection and tracking scheme based on the magnitude and direction of integrated water vapour transport is presented and applied separately over 13 regions located along the west coasts of Europe (including North Africa) and North America. Four distinct reanalyses are considered, two of which cover the entire twentieth-century: NOAA-CIRES Twentieth Century Reanalysis v2 (NOAA-20C) and ECMWF ERA-20C. Calculations are done separately for the OND and JFM-season and, for comparison with previous studies, for the ONDJFM-season as a whole. Comparing the AR-counts from NOAA-20C and ERA-20C with a running 31-year window looping through 1900-2010 reveals differences in the climatological mean and inter-annual variability which, at the start of the twentieth-century, are much more pronounced in western North America than in Europe. Correlating European AR-counts with the North Atlantic Oscillation (NAO) reveals a pattern reminiscent of the well-know precipitation dipole which is stable throughout the entire century. A similar analysis linking western North American AR-counts to the North Pacific index (NPI) is hampered by the aforementioned poor reanalysis agreement at the start of the century. During the second half of the twentieth-century, the strength of the NPI-link considerably varies with time in British Columbia and the Gulf of Alaska. Considering the period 1950-2010, AR-counts are then associated with other relevant large-scale circulation indices such as the East Atlantic, Scandinavian, Pacific-North American and West Pacific patterns (EA, SCAND, PNA and WP). Along the Atlantic coastline of the Iberian Peninsula and France, the EA-link is stronger than the NAO-link if the OND season is considered and the SCAND-link found in northern Europe is significant during both seasons. Along the west coast of North America, teleconnections are generally stronger during JFM in which case the NPI-link is significant in any of the five considered

  18. Suicides in the indigenous and non-indigenous populations in the Nenets Autonomous Okrug, Northwestern Russia, and associated socio-demographic characteristics

    Science.gov (United States)

    Sumarokov, Yury A.; Brenn, Tormod; Kudryavtsev, Alexander V.; Nilssen, Odd

    2014-01-01

    Background To describe suicide rates in the indigenous and non-indigenous populations of the Nenets Autonomous Okrug (NAO) in 2002–2012, as well as associated socio-demographic characteristics. Study design Retrospective population-based mortality study. Methods Data from autopsy reports were used to identify 252 cases of suicide in the NAO in 2002–2012. Data on socio-demographic characteristics of these cases were obtained from passports and medical records at local primary health care units, and were then linked to total population data from the Censuses in 2002 and 2010. Suicide rates for the indigenous Nenets population and the non-indigenous population were standardized to the European standard population. The rates were also estimated according to different socio-demographic characteristics and compared by calculating relative risks. Results The crude suicide rates were 79.8 per 100,000 person-years (PYs) in the Nenets population and 49.2 per 100,000 PYs in the non-indigenous population. The corresponding standardized estimates were 72.7 per 100,000 PYs and 50.7 per 100,000 PYs. The highest suicide rates in the Nenets population were observed in the age group 20–29 years (391 per 100,000 PYs), and in females aged 30–39 years (191 per 100,000 PYs). Socio-demographic characteristics associated with high suicide rates in the Nenets population were age 20–39 years, male, urban residence, having secondary school or higher education, being an employee or employer, and being single or divorced. Males aged 20–29 years, and females aged 30–39 and aged 70 years and above had the highest suicide rates in the non-indigenous population (137.5, 21.6 and 29.9 per 100,000 PYs, respectively). The elevated suicide rates observed in the non-indigenous population were associated with male sex, rural residence, secondary school education, being an employee or employer, and being single or divorced. Conclusions Suicide rates in the NAO were substantially higher among

  19. Baroclinic wave configurations evolution at European scale in the period 1948-2013

    Science.gov (United States)

    Carbunaru, Daniel; Burcea, Sorin; Carbunaru, Felicia

    2016-04-01

    The main aim of the study was to investigate the dynamic characteristics of synoptic configurations at European scale and especially in south-eastern part of Europe for the period 1948-2013. Using the empirical orthogonal functions analysis, simultaneously applied to daily average geopotential field at different pressure levels (200 hPa, 300 hPa, 500 hPa and 850 hPa) during warm (April-September) and cold (October-March) seasons, on a synoptic spatial domain centered on Europe (-27.5o lon V to 45o lon E and 32.5o lat N to 72.5o lat N), the main mode of oscillation characteristic to vertical shift of mean baroclinic waves was obtained. The analysis independently applied on 66 years showed that the first eigenvectors in warms periods describe about 60% of the data and in cold season 40% of the data for each year. In comparison secondary eigenvectors describe up to 20% and 10% of the data. Thus, the analysis was focused on the complex evolution of the first eigenvector in 66 years, during the summer period. On average, this eigenvector describes a small vertical phase shift in the west part of the domain and a large one in the eastern part. Because the spatial extent of the considered synoptic domain incorporates in the west part AMO (Atlantic Multidecadal Oscillation) and NAO (North Atlantic Oscillation) oscillations, and in the north part being sensitive to AO (Arctic Oscillation) oscillation, these three oscillations were considered as modulating dynamic factors at hemispherical scale. The preliminary results show that in the summer seasons AMO and NAO oscillations modulated vertical phase shift of baroclinic wave in the west of the area (Northwestern Europe), and the relationship between AO and NAO oscillations modulated vertical phase shift in the southeast area (Southeast Europe). Second, it was shown the way in which this vertical phase shift modulates the overall behavior of cyclonic activity, particularly in Southeastern Europe. This work has been developed

  20. Effect of Modulation of ENSO by Decadal and Multidecadal Ocean-Atmospheric Oscillations on Continental US Streamflows

    Science.gov (United States)

    Singh, S.; Abebe, A.; Srivastava, P.; Chaubey, I.

    2017-12-01

    Evaluation of the influences of individual and coupled oceanic-atmospheric oscillations on streamflow at a regional scale in the United States is the focus of this study. The main climatic oscillations considered in this study are: El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and North Atlantic Oscillation (NAO). Unimpacted or minimally impacted by water management streamflow data from the Model Parameter Estimation Experiment (MOPEX) were used in this study. Two robust and novel non-parametric tests, namely, the rank based partial least square (PLS) and the Joint Rank Fit (JRFit) procedures were used to identify the individual and coupled effect of oscillations on streamflow across continental U.S. (CONUS), respectively. Moreover, the interactive effects of ENSO with decadal and multidecadal cycles were tested and quantified using the JRFit interaction test. The analysis of ENSO indicated higher streamflows during La Niña phase compared to the El Niño phase in Northwest, Northeast and the lower part of Ohio Valley while the opposite occurs for rest of the climatic regions in US. Two distinct climate regions (Northwest and Southeast) were identified from the PDO analysis where PDO negative phase results in increased streamflow than PDO positive phase. Consistent negative and positive correlated regions around the CONUS were identified for AMO and NAO, respectively. The interaction test of ENSO with decadal and multidecadal oscillations showed that El Niño is modulated by the negative phase of PDO and NAO, and the positive phase of AMO, respectively, in the Upper Midwest. However, La Niña is modulated by the positive phase of AMO and PDO in Ohio Valley and Northeast while in Southeast and the South it is modulated by AMO negative phase. Results of this study will assist water managers to understand the streamflow change patterns across the CONUS at decadal and multi-decadal time scales. The

  1. Subseasonal climate variability for North Carolina, United States

    Science.gov (United States)

    Sayemuzzaman, Mohammad; Jha, Manoj K.; Mekonnen, Ademe; Schimmel, Keith A.

    2014-08-01

    Subseasonal trends in climate variability for maximum temperature (Tmax), minimum temperature (Tmin) and precipitation were evaluated for 249 ground-based stations in North Carolina for 1950-2009. The magnitude and significance of the trends at all stations were determined using the non-parametric Theil-Sen Approach (TSA) and the Mann-Kendall (MK) test, respectively. The Sequential Mann-Kendall (SQMK) test was also applied to find the initiation of abrupt trend changes. The lag-1 serial correlation and double mass curve were employed to address the data independency and homogeneity. Using the MK trend test, statistically significant (confidence level ≥ 95% in two-tailed test) decreasing (increasing) trends by 44% (45%) of stations were found in May (June). In general, trends were decreased in Tmax and increased in Tmin data series in subseasonal scale. Using the TSA method, the magnitude of lowest (highest) decreasing (increasing) trend in Tmax is - 0.050 °C/year (+ 0.052 °C/year) in the monthly series for May (March) and for Tmin is - 0.055 °C/year (+ 0.075 °C/year) in February (December). For the precipitation time series using the TSA method, it was found that the highest (lowest) magnitude of 1.00 mm/year (- 1.20 mm/year) is in September (February). The overall trends in precipitation data series were not significant at the 95% confidence level except that 17% of stations were found to have significant (confidence level ≥ 95% in two-tailed test) decreasing trends in February. The statistically significant trend test results were used to develop a spatial distribution of trends: May for Tmax, June for Tmin, and February for precipitation. A correlative analysis of significant temperature and precipitation trend results was examined with respect to large scale circulation modes (North Atlantic Oscillation (NAO) and Southern Oscillation Index (SOI). A negative NAO index (positive-El Niño Southern Oscillation (ENSO) index) was found to be associated with

  2. Chaves analíticas para determinação de cultivares de aboboreiras, morangueiras e mogangueiras

    OpenAIRE

    Rochelle, Luiz Antonio

    1980-01-01

    De sete cultivares de aboboreiras rasteiras, pertencentes à espécie Cucurbita moschata Duch., duas morangueiras e duas mogangueiras, da espécie Cucurbita maxima Duch., uma aboboreira nao rasteira e uma morangueira pertencente a Cucurbita pepo L., elaborou-se chaves analíticas para determina-los, fundamentando-se nos caracteres morfológicos do caule e das folhas. Keys determining cultivars of squashes and pumpkins (Cucurbita mosohata Duch., Cueurbita maxima Duch., and Cucurbita pepo L.) bas...

  3. Artificial companions as personal coach for children: The Interactive Drums Teacher

    OpenAIRE

    Courgeon , Matthieu; Duhaut , Dominique

    2015-01-01

    International audience; The MOCA Project that aims at designing and studying the interaction and relationship between artificial companions and children in everyday life at home activities. Artificial companions are digital embodied entities that can be either robotic or virtual. In this paper, we focus on a single activity, subpart of the whole project: a coaching application that uses two artificial companions to teach the basics of drums to children. One device is a Nao robot, the other is...

  4. AA.VV. Oriente en Granada. Granada: Fundación Caja Rural, 2008, 120 pp. y 69 ils.

    Directory of Open Access Journals (Sweden)

    Cristina Aguado Padial

    2009-12-01

    Full Text Available España, desde el siglo XVI, mantuvo relaciones comerciales con Oriente, siguiendo el itinerario de la Carrera de Indias —partiendo de Sevilla y pasando por Veracruz (México hasta Acapulco, la Nao de la China o Manila, realizando para la vuelta el mismo trayecto, pero a la inversa—, llegando así a nuestro país productos como porcelanas, sedas o marfiles, entre otros...

  5. Oral hyaluronan relieves wrinkles: a double-blinded, placebo-controlled study over a 12-week period

    OpenAIRE

    Oe, Mariko; Sakai, Seigo; Yoshida, Hideto; Okado, Nao; Kaneda, Haruna; Masuda, Yasunobu; Urushibata, Osamu

    2017-01-01

    Mariko Oe,1 Seigo Sakai,1 Hideto Yoshida,1 Nao Okado,1 Haruna Kaneda,1 Yasunobu Masuda,1 Osamu Urushibata2 1R&D Division, Kewpie Corporation, Sengawa-cho, Chofu-shi, 2Department of Dermatology, Toho University Ohashi Medical Center, Ohashi, Meguro-ku, Tokyo, Japan Background: Hyaluronan (HA) has critical moisturizing property and high water retention capacity especially for human skin. This study aimed to evaluate the effect of oral intake of HA. Methods: The mean molecular weight (MW...

  6. Dióxido de Carbono na secreção do peptídeo relacionado com Gene de Calcitonina e Substância P em pele de ratos

    OpenAIRE

    Silva, Erica Calcagno Raymundo da [UNIFESP

    2013-01-01

    Introdução: Estudos sugerem que o CO2 promova estimulo dos efeitos fisiologicos como, vasodilatacao, formacao de colageno e fibras elasticas. A Inflamacao Neurogenica (IN) e um dos primeiros eventos da cicatrizacao em resposta a um estimulo nociceptivo na pele, onde ha liberacao de neuropeptideos (NPÆs) pro-inflamatorios secretados por terminacoes nervosas, sendo lancados na fase inflamatoria da cicatrizacao. Entretanto nao ha estudos que relacionem a injecao de CO2 com a IN. Objetivo: invest...

  7. Dynamics of Arctic and Sub-Arctic Climate and Atmospheric Circulation: Diagnosis of Mechanisms and Model Biases Using data Assimilation

    Energy Technology Data Exchange (ETDEWEB)

    Sumant Nigam

    2013-02-05

    These five publications are summarized: Key role of the Atlantic Multidecadal Oscillation in 20th century drought and wet periods over the Great Plains; A Sub-Seasonal Teleconnection Analysis: PNA Development and Its Relationship to the NAO; AMO's Structure and Climate Footprint in Observations and IPCC AR5 Climate Simulations; The Atlantic Multidecadal Oscillation in 20th Century Climate Simulations: Uneven Progress from CMIP3 to CMIP5; and Tropical Atlantic Biases in CCSM4.

  8. A luz alem da visão : iluminação e sua relação com a saude e bem-estar de funcionarias de lojas de rua e de shopping centers em Porto Alegre

    OpenAIRE

    Betina Tschiedel Martau

    2009-01-01

    Resumo: Este trabalho aborda os impactos nao visuais da exposicao humana a luz tentandorelacionar a qualidade da iluminacao a saude e bem-estar das funcionarias de lojas. A amostrado estudo transversal foi definida aleatoriamente, com a participacao de mulheres voluntarias.Foram selecionados tres grupos com dez participantes em cada: lojas de rua com contato comexterior e turno de trabalho diurno (9h as18h), lojas de shopping centers sem janelas para oexterior com turno de trabalho diurno (10...

  9. Catalytic pyrolysis of LDPE using modified vermiculite as a catalyst; Pirolise catalitica do PEBD usando como catalisador a vermiculita modificada

    Energy Technology Data Exchange (ETDEWEB)

    Bezerra, Franciel Aureliano [Universidade Federal de Uberlandia (UFU), MG (Brazil); Figueiredo, Aneliese Lunguinho; Araujo, Antonio Souza de; Guedes, Ana Paula de Melo Alves, E-mail: anachemistry@hotmail.com [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil)

    2016-07-01

    Low density polyethylene (LDPE) is one of the most commonly-used polymers currently, and the great quantity of this polymer produced results in tons of waste that must be treated. We studied the thermocatalytic pyrolysis of LDPE with a modified clay vermiculite catalyst as an alternative for treatment of waste. The clay was treated with a solution of nitric acid at different concentrations and calcined at 400 °C. The materials were characterized by X-ray diffraction, thermogravimetry, nitrogen adsorption, and energy dispersive spectroscopy. Thermal and thermocatalytic pyrolysis were carried out in a microreactor coupled with GC/MS at 500 °C. The aim of the polymeric waste pyrolysis is the obtainment of light hydrocarbons (C<16), which can be used in the chemical and petrochemical industry, through breaks in the polymer chain. The results were satisfactory, with an increase in yield for light hydrocarbons by using catalysts reaching up to 71.4% of products with C<16, whereas thermal pyrolysis resulted in only 25.8%. (author)

  10. Marine proxy evidence linking decadal North Pacific and Atlantic climate

    Energy Technology Data Exchange (ETDEWEB)

    Hetzinger, S. [University of Toronto Mississauga, CPS-Department, Mississauga, ON (Canada); Leibniz Institute of Marine Sciences, IFM-GEOMAR, Kiel (Germany); Halfar, J. [University of Toronto Mississauga, CPS-Department, Mississauga, ON (Canada); Mecking, J.V.; Keenlyside, N.S. [Leibniz Institute of Marine Sciences, IFM-GEOMAR, Kiel (Germany); University of Bergen, Geophysical Institute and Bjerknes Centre for Climate Research, Bergen (Norway); Kronz, A. [University of Goettingen, Geowissenschaftliches Zentrum, Goettingen (Germany); Steneck, R.S. [University of Maine, Darling Marine Center, Walpole, ME (United States); Adey, W.H. [Smithsonian Institution, Department of Botany, Washington, DC (United States); Lebednik, P.A. [ARCADIS U.S. Inc., Walnut Creek, CA (United States)

    2012-09-15

    Decadal- to multidecadal variability in the extra-tropical North Pacific is evident in 20th century instrumental records and has significant impacts on Northern Hemisphere climate and marine ecosystems. Several studies have discussed a potential linkage between North Pacific and Atlantic climate on various time scales. On decadal time scales no relationship could be confirmed, potentially due to sparse instrumental observations before 1950. Proxy data are limited and no multi-centennial high-resolution marine geochemical proxy records are available from the subarctic North Pacific. Here we present an annually-resolved record (1818-1967) of Mg/Ca variations from a North Pacific/Bering Sea coralline alga that extends our knowledge in this region beyond available data. It shows for the first time a statistically significant link between decadal fluctuations in sea-level pressure in the North Pacific and North Atlantic. The record is a lagged proxy for decadal-scale variations of the Aleutian Low. It is significantly related to regional sea surface temperature and the North Atlantic Oscillation (NAO) index in late boreal winter on these time scales. Our data show that on decadal time scales a weaker Aleutian Low precedes a negative NAO by several years. This atmospheric link can explain the coherence of decadal North Pacific and Atlantic Multidecadal Variability, as suggested by earlier studies using climate models and limited instrumental data. (orig.)

  11. Links of the significant wave height distribution in the Mediterranean sea with the Northern Hemisphere teleconnection patterns

    Directory of Open Access Journals (Sweden)

    P. Lionello

    2008-06-01

    Full Text Available This study analyzes the link between the SWH (Significant Wave Height distribution in the Mediterranean Sea during the second half of the 20th century and the Northern Hemisphere SLP (Sea Level Pressure teleconnection patterns.

    The SWH distribution is computed using the WAM (WAve Model forced by the surface wind fields provided by the ERA-40 reanalysis for the period 1958–2001. The time series of mid-latitude teleconnection patterns are downloaded from the NOAA web site. This study shows that several mid-latitude patterns are linked to the SWH field in the Mediterranean, especially in its western part during the cold season: East Atlantic Pattern (EA, Scandinavian Pattern (SCA, North Atlantic Oscillation (NAO, East Atlantic/West Russia Pattern (EA/WR and East Pacific/ North Pacific Pattern (EP/NP. Though the East Atlantic pattern exerts the largest influence, it is not sufficient to characterize the dominant variability. NAO, though relevant, has an effect smaller than EA and comparable to other patterns. Some link results from possibly spurious structures. Patterns which have a very different global structure are associated to similar spatial features of the wave variability in the Mediterranean Sea. These two problems are, admittedly, shortcomings of this analysis, which shows the complexity of the response of the Mediterranean SWH to global scale SLP teleconnection patterns.

  12. Decadal trends in atmospheric deposition in a high elevation station: Effects of climate and pollution on the long-range flux of metals and trace elements over SW Europe

    Science.gov (United States)

    Camarero, Lluís; Bacardit, Montserrat; de Diego, Alberto; Arana, Gorka

    2017-10-01

    Atmospheric deposition collected at remote, high elevation stations is representative of long-range transport of elements. Here we present time-series of Al, Fe, Ti, Mn, Zn, Ni, Cu, As, Cd and Pb deposition sampled in the Central Pyrenees at 2240 m a.s.l, representative of the fluxes of these elements over South West Europe. Trace element deposition did not show a simple trend. Rather, there was statistical evidence of several underlying factors governing the variability of the time-series recorded: seasonal cycles, trends, the effects of the amount of precipitation, climate-controlled export of dust, and changes in anthropogenic emissions. Overall, there were three main modes of variation in deposition. The first mode was related to North Atlantic Oscillation (NAO), and affected Al, Fe, Ti, Mn and Pb. We interpret this as changes in the dust export from Northern Africa under the different meteorological conditions that the NAO index indicates. The second mode was an upward trend related to a rise in the frequency of precipitation events (that also lead to an increase in the amount). More frequent events might cause a higher efficiency in the scavenging of aerosols. As, Cu and Ni responded to this. And finally, the third mode of variation was related to changes in anthropogenic emissions of Pb and Zn.

  13. Los nombres de persona de los troyanos y de los griegos en la Iliada

    Directory of Open Access Journals (Sweden)

    Emilio Crespo

    2005-12-01

    Full Text Available Este artigo examina os antropônimos, os epítetos e os hábitos atribuídos aos troianos, aqueus, argivos e dânaos na Ilíada. A maioria dos antropônimos derivados de topônimos e de étnicos são atribuídos a personagens que pertencem ao lado onde está situado o lugar ou o povo do qual deriva seu nome. Em outras palavras, cada lado está associado a uma área geográfica diferente. Além disso, os antropônimos que carecem de etimologia grega e parecem estar relacionados com uma língua anatólia são usados para troianos e para seus aliados, mas raramente para os aqueus, argivos e dânaos. Ambos os fatos sugerem que a Ilíada apresenta os gregos com um sentido de identidade comum, embora a designação Hellenes no sentido de 'gregos' esteja ausente da Ilíada. O elevado número de antropônimos derivados de topônimos, de étnicos e de acidentes geográficos da Trôade sugere que o autor da Ilíada estava familiarizado com a geografia da Trôade.

  14. Multi-scale analysis of teleconnection indices: climate noise and nonlinear trend analysis

    Directory of Open Access Journals (Sweden)

    C. Franzke

    2009-02-01

    Full Text Available The multi-scale nature and climate noise properties of teleconnection indices are examined by using the Empirical Mode Decomposition (EMD procedure. The EMD procedure allows for the analysis of non-stationary time series to extract physically meaningful intrinsic mode functions (IMF and nonlinear trends. The climatologically relevant monthly mean teleconnection indices of the North Atlantic Oscillation (NAO, the North Pacific index (NP and the Southern Annular Mode (SAM are analyzed.

    The significance of IMFs and trends are tested against the null hypothesis of climate noise. The analysis of surrogate monthly mean time series from a red noise process shows that the EMD procedure is effectively a dyadic filter bank and the IMFs (except the first IMF are nearly Gaussian distributed. The distribution of the variance contained in IMFs of an ensemble of AR(1 simulations is nearly χ2 distributed. To test the statistical significance of the IMFs of the teleconnection indices and their nonlinear trends we utilize an ensemble of corresponding monthly averaged AR(1 processes, which we refer to as climate noise. Our results indicate that most of the interannual and decadal variability of the analysed teleconnection indices cannot be distinguished from climate noise. The NP and SAM indices have significant nonlinear trends, while the NAO has no significant trend when tested against a climate noise hypothesis.

  15. What Causes the North Sea Level to Rise Faster over the Last Decade ?

    Science.gov (United States)

    Karpytchev, Mikhail; Letetrel, Camille

    2013-04-01

    We combined tide gauge records (PSMSL) and satellite altimetry data (TOPEX/POSEIDON-JASON 1-2) to reconstruct the mean level of the North Sea and the Norwegian Sea Shelf (NS-NSS) over 1950-2012. The reconstructed NS-NSS mean sea level fluctuations reveal a pronounced interannual variability and a strong sea level acceleration since the mid-1990's. In order to understand the causes of this acceleration, the NS-NSS mean sea level was cross-correlated with the North Atlantic Oscillation and Arctic Oscillation indices. While the interannual variability of the mean sea level correlates well with the NAO/AO indices, the observed acceleration in the NS-NSS mean level is not linked linearly to the NAO/AO fluctuations. On the other hand, the Empirical Orthogonal Functions (EOF) analysis of steric sea level variations in the eastern North Atlantic gives a dominant EOF pattern (55% of variance explained) that varies on a decadal scale very closely to the NS-NSS mean level flcutuations. Also, the amplification in the temporal amplitude of the dominant steric sea level EOF corresponds to the acceleration observed in the NS-NSS mean sea level signal. This suggests that decadal variations in the mean level of the North Sea - the Norwegian Sea Shelf reflect changes in the Subpolar Front currents (Rossby, 1996).

  16. Changes in atmospheric variability in a glacial climate and the impacts on proxy data: a model intercomparison

    Directory of Open Access Journals (Sweden)

    F. S. R. Pausata

    2009-09-01

    Full Text Available Using four different climate models, we investigate sea level pressure variability in the extratropical North Atlantic in the preindustrial climate (1750 AD and at the Last Glacial Maximum (LGM, 21 kyrs before present in order to understand how changes in atmospheric circulation can affect signals recorded in climate proxies.

    In general, the models exhibit a significant reduction in interannual variance of sea level pressure at the LGM compared to pre-industrial simulations and this reduction is concentrated in winter. For the preindustrial climate, all models feature a similar leading mode of sea level pressure variability that resembles the leading mode of variability in the instrumental record: the North Atlantic Oscillation (NAO. In contrast, the leading mode of sea level pressure variability at the LGM is model dependent, but in each model different from that in the preindustrial climate. In each model, the leading (NAO-like mode of variability explains a smaller fraction of the variance and also less absolute variance at the LGM than in the preindustrial climate.

    The models show that the relationship between atmospheric variability and surface climate (temperature and precipitation variability change in different climates. Results are model-specific, but indicate that proxy signals at the LGM may be misinterpreted if changes in the spatial pattern and seasonality of surface climate variability are not taken into account.

  17. Evaluation of a new CNRM-CM6 model version for seasonal climate predictions

    Science.gov (United States)

    Volpi, Danila; Ardilouze, Constantin; Batté, Lauriane; Dorel, Laurant; Guérémy, Jean-François; Déqué, Michel

    2017-04-01

    This work presents the quality assessment of a new version of the Météo-France coupled climate prediction system, which has been developed in the EU COPERNICUS Climate Change Services framework to carry out seasonal forecast. The system is based on the CNRM-CM6 model, with Arpege-Surfex 6.2.2 as atmosphere/land component and Nemo 3.2 as ocean component, which has directly embedded the sea-ice component Gelato 6.0. In order to have a robust diagnostic, the experiment is composed by 60 ensemble members generated with stochastic dynamic perturbations. The experiment has been performed over a 37-year re-forecast period from 1979 to 2015, with two start dates per year, respectively in May 1st and November 1st. The evaluation of the predictive skill of the model is shown under two perspectives: on the one hand, the ability of the model to faithfully respond to positive or negative ENSO, NAO and QBO events, independently of the predictability of these events. Such assessment is carried out through a composite analysis, and shows that the model succeeds in reproducing the main patterns for 2-meter temperature, precipitation and geopotential height at 500 hPa during the winter season. On the other hand, the model predictive skill of the same events (positive and negative ENSO, NAO and QBO) is evaluated.

  18. Relationship between Eurasian large-scale patterns and regional climate variability over the Black and Baltic Seas

    Energy Technology Data Exchange (ETDEWEB)

    Stankunavicius, G.; Pupienis, D. [Vilnius Univ. (Lithuania). Dept. of Hydrology and Climatology; Basharin, D. [National Academy of Science of Ukraine, Sevastopol (Ukraine). Sevastopol Marine Hydrophysical Inst.

    2012-11-01

    Using a NCEP/NCAR Reanalysis dataset and the empirical orthogonal function (EOF) analysis approach we studied interannual to decadal variabilities of the sea-level air pressure (SLP) and the surface air temperature (SAT) fields over Eurasia during the 2nd part of the 20th century. Our results agree with those of the previous studies, which conclude that Eurasian trends are the result of storm-path changes driven by the interdecadal behaviour of the NAO-like meridional dipole pattern in the Atlantic. On interannual and decadal time scales, significant synchronous correlations between correspondent modes of SAT and SLP EOF patterns were found. This fact suggests that there is a strong and stable Eurasian interrelationship between SAT and SLP large-scale fields which affects the local climate of two sub-regions: the Black and Baltic Seas. The climate variability in these sub-regions was studied in terms of Eurasian large-scale surface-temperature and air-pressure patterns responses. We concluded that the sub-regional climate variability substantially differs over the Black and Baltic Seas, and depends on different Eurasian large-scale patterns. We showed that the Baltic Sea region is influenced by the patterns arising primary from NAO-like meridional dipole, as well as Scandinavian patterns, while the Black Sea's SAT/SLP variability is influenced mainly by the second mode EOF (eastern Atlantic) and large scale tropospheric wave structures. (orig.)

  19. The spectroscopic analysis of {gamma}-irradiated glass by colorimetry, ESR and XPS

    Energy Technology Data Exchange (ETDEWEB)

    Hong, S.I. [College of Life Sciences and Biotechnology, Korea University, 5 ga Anam-dong, Seongbuk-Gu, Seoul 135-701 (Korea, Republic of); Lee, Y.N. [R and D Institute Biscuit Team, 131-1, Namyoung-dong, Youngsan-Gu, Seoul 140-708 (Korea, Republic of); Cho, S.Y. [College of Life Sciences and Biotechnology, Korea University, 5 ga Anam-dong, Seongbuk-Gu, Seoul 135-701 (Korea, Republic of); Whiteside, W.S. [Department of Packaging Science, 226 Poole Agricultural Center, Clemson University, Clemson, SC 29634-0320 (United States); Park, H.J. [College of Life Sciences and Biotechnology, Korea University, 5 ga Anam-dong, Seongbuk-Gu, Seoul 135-701 (Korea, Republic of)], E-mail: hjpark@korea.ac.kr

    2008-09-15

    The darkening of {gamma}-irradiated glass was related to the binding of Si-O and Sn-O, and the binding of Na-O. The dosimetric range of glass color change was evaluated by colorimetry, UV-Vis spectrophotometry and ESR. Colorimetry and UV-Vis spectrophotometry, revealed linear changes up to 9 kGy. For the calibration curve of {gamma}-irradiation, the signal of g=2.01 observed by ESR responded most sensitively with a linear increase with up to 12 kGy.

  20. The spectroscopic analysis of γ-irradiated glass by colorimetry, ESR and XPS

    International Nuclear Information System (INIS)

    Hong, S.I.; Lee, Y.N.; Cho, S.Y.; Whiteside, W.S.; Park, H.J.

    2008-01-01

    The darkening of γ-irradiated glass was related to the binding of Si-O and Sn-O, and the binding of Na-O. The dosimetric range of glass color change was evaluated by colorimetry, UV-Vis spectrophotometry and ESR. Colorimetry and UV-Vis spectrophotometry, revealed linear changes up to 9 kGy. For the calibration curve of γ-irradiation, the signal of g=2.01 observed by ESR responded most sensitively with a linear increase with up to 12 kGy

  1. Trends and Variability of the Outdoor Skating Season in Canada during 1951-2005

    Science.gov (United States)

    Damyanov, Nikolay Nikolaev

    Climate change affects a range of human activities, including one of Canada's prime sources of entertainment: ice skating. Whether done recreationally or as hockey, its outdoor component is heavily dependent on weather and climate. Based on information obtained from public works officials from various Canadian cities, I have established a meteorological criterion for the initiation of an outdoor skating season (OSS) as the last day in a sequence of the first three consecutive fall/winter days with a maximum temperature below -5 °C. In addition, I derive a proxy of the OSS length, defined as the total number of days with a maximum temperature below -5 °C after the OSS start date and before the start of March. Using these filters, I have extracted the start dates and the lengths of the OSS for each year during the fifty-five year period 1951-2005 from a comprehensive daily temperature dataset (Vincent et al., 2002). For each station, I created time series of both the OSS start dates and OSS lengths, and calculated the magnitude, sign and statistical significance of the slopes of the best-fit lines to each time series. In order to establish a relationship of the OSS with large-scale climate patterns, I grouped stations into six climatic regions. Depending on location, I then tested each region for correlation with the Pacific North-American teleconnection pattern (PNA) or the North Atlantic Oscillation (NAO), using a composite analysis method. Lastly, I removed the signal due to these climate fluctuations from the OSS start date and length trends in order to determine how much of the variability was caused by these interannual climate oscillations. The results of the study indicate that most stations in British Columbia and southwest Alberta, as well as these in the southern Ontario/Quebc region have witnessed a progressively later onset of the OSS over time. The Prairies, northwest Canada, and some Maritime locales show the opposite trend, although the magnitudes

  2. Acute toxicity of pyrazosulfuron-ethyl and permethrin to juvenile Litopenaeus vannamei =Toxicidade aguda de pirazossulfurom-etílico e permethrin em juvenis de camarão branco Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Giovanni Lemos de Mello

    2011-01-01

    Full Text Available The objective of this study was to determine the LC50 (96h of two pesticides: SiriusR 250 SC herbicide of the pyrazosulfuron-ethyl group, and TalcordR insecticide of the permethrin group, on juvenile Litopenaeus vannamei. Shrimp total hemocyte count (THC was also determined as an indication of physiological alterations caused by the pesticides. Juvenile shrimp (5.0 } 0.5 g were exposed to the following concentrations: 0, 0.1, 1.0, 10, 100 and 1000 ƒÊg L-1 SiriusR 250 SC; and 0, 0.001, 0.01, 0.1, 1.0 and 10 ƒÊg L-1 TalcordR. The TalcordR LC50 (96h was of 0.00933 ƒÊg L-1 or 9.33 ng L-1. There were no significant changes in the THC between control and test groups. No SiriusR 250 SC concentrations tested killed more than 50%of the shrimp; therefore, the herbicide was considered not toxic to the juveniles. However, the THC showed significant differences between the control and test groups, suggesting sublethal effects to L. vannamei juveniles. According to the results, the insecticide TalcordR is highly lethal for L. vannamei and the herbicide SiriusR 250 SC was not lethal in the concentrations tested but showed sublethal effects as lower THC. The results demonstrate the risks involved in farming L. vannamei shrimp near rice cultures where these pesticides are routinely used.O objetivo deste trabalho foi determinar a CL50 (96h dos agroquimicos SiriusR 250 SC, herbicida a base de pirazossulfurom-etilico, e TalcordR, inseticida a base de permethrin, em juvenis de Litopenaeus vannamei, bem como avaliar possiveis alteracoes fisiologicas por meio da contagem total de hemocitos (CTH dos camaroes. Juvenis de L. vannamei (5,0 } 0,5 g foram expostos as seguintes concentracoes dos agroquimicos: SiriusR 250 SC, 0; 0,1; 1; 10; 100 e 1.000 ƒÊg L-1, e TalcordR, 0; 0,001; 0,01; 0,1; 1 e 10 ƒÊg L-1. A CL50 (96h do inseticida TalcordR foi de 0,00933 ƒÊg L-1 ou 9,33 ng L-1. Nao houve alteracoes significativas da CTH entre as medias dos grupos

  3. Avaliacao da Relacao entre a Doenca Hepatica Nao Gordurosa e CAD utilizando TCMF

    Directory of Open Access Journals (Sweden)

    Duran Efe

    2014-01-01

    Full Text Available Fundamento: Alguns fatores de risco para a aterosclerose são acompanhados pela doença hepática gordurosa não alcoólica (DHGNA. Desejamos usar a tomografia computadorizada multi-fatias (TCMF como a técnica para encontrar relação entre a DHGNA e a doença arterial coronariana (DAC. Objetivo: A relação entre a DHGNA e a DAC foi investigada através de TCMF. Métodos: Um total de 372 indivíduos com ou sem sintomas cardíacos, que foram submetidos à angiografia por TCMF, foram incluídos no estudo. Os pacientes foram divididos em dois grupos, de acordo com a presença da DHGNA. Os segmentos arteriais coronarianos foram avaliados visualmente via angiografia por TCMF. Com base no grau de estenose arterial coronariana, aqueles com placas ausentes ou mínimas foram considerados como normais, enquanto aqueles que apresentavam estenose de menos do que 50% e no mínimo uma placa foram considerados como portadores da doença arterial coronariana não obstrutiva (não-obsDAC. Os pacientes que apresentaram no mínimo uma placa e estenose arterial coronariana de 50% ou mais foram considerados como portadores de doença arterial coronariana obstrutiva (obsDAC. A DHGNA foi determinada de acordo com o protocolo de TCMF, utilizando a densidade hepática. Resultados: De acordo com a densidade hepática, o número de pacientes com doença hepática gordurosa não alcoólica (grupo 1 foi de 204 (149 homens, 54,8% e com fígado normal (grupos 2 foi de 168 (95 homens, 45.2%. Houve 50 (24,5% não-obsDAC e 57 (27,9% casos de obsDAC no Grupo 1, e 39 (23,2% não-obsDAC e 23 (13,7% casos de obsDAC no Grupo 2. Conclusões: O presente estudo utilizando TCMF demonstrou que a frequência da doença arterial coronariana em pacientes com NAFDL foi significativamente superior do que nos pacientes em NAFDL.

  4. Naos, clima y glaciares en el Estrecho de Magallanes durante el siglo XVI

    Directory of Open Access Journals (Sweden)

    Prieto, María del Rosario

    1998-12-01

    Full Text Available Not available.

    El objetivo de este trabajo es lograr una aproximación al clima y a los fenómenos de glaciación ocurridos en el Estrecho de Magallanes durante el siglo XVI y parte del XVII a través de registros históricos. Se complementan los resultados obtenidos por investigadores de otras disciplinas paleoclimáticas en el área, verificándose si las fuentes históricas corroboran las conclusiones de esos autores, quienes postulan un intervalo muy frío entre 1520 y 1670. Para realizar esta investigación se utilizaron los “diarios o relaciones de navegación” de los primeros marinos españoles que pasaron por el Estrecho, recopilados en su mayor parte en Archivos históricos españoles. A través de la técnica del análisis de contenido se verificó la estabilidad en el vocabulario referido al clima y los glaciares a lo largo de esas centurias y se calificó los eventos de acuerdo a su magnitud. Se determinaron diversas categorías de las cuales se han seleccionado precipitaciones sólidas y líquidas, temperatura, dirección del viento y ocurrencia de tormentas para analizar en este trabajo. Se estudió especialmente la presencia de témpanos en el Estrecho y las descripciones de los glaciares fueguinos y del sur de la Patagonia chilena como indicadores de bajas temperaturas. Se concluye que existen referencias directas a la presencia de témpanos proveniente de glaciares en el Estrecho, sólo en la segunda mitad del siglo XVI. El avance de los hielos supondría una acentuación de las condiciones de frío durante esa centuria, lo que puede ser corroborado por los datos de los navíos que consignan temperaturas estivales frías y muy frías en la vertiente pacífica. Estos datos coincidirían con los resultados de R. Villalba en cuanto a que el intervalo 1520 a 1670 fue uno de los más fríos de la Pequeña Edad Glaciar.

  5. Allanças de marca. por que, como e quando?

    OpenAIRE

    Marin, Longinos; Rubio, Alicia

    2012-01-01

    Nos ultimos anos, as atividades de aliança de marta tiveram um crescente protagonismo no lançamento de novos produtos por parte das empresas. Nao obstante, existem poucos trabalhos que analisem de forma integral a justificaçao par parte das empresas sobre esta estrategia. O presente trabalho analisa as teorias que justificam porque e em que cenarios devem ser utilizadas as alianças de marca desde a perspectiva do comportamento do consumidor. O artigo tambem aprofunda nas condiçoes enos cenari...

  6. Reactions of vanadium(5) with aluminium(3) in weakly acid aqueous solutions

    International Nuclear Information System (INIS)

    Ditrikh, I.V.; Makhno, A.Ya.

    1996-01-01

    Conditions of vanadium(5) heteropolycompounds formation in aqueous solutions containing aluminium(3) have been studied. By the methods of potentiometry and conductometry in solutions of Al(NO 3 ) 3 -NaVO 3 salt mixture the formation of complexes with the ratios [Al 3+ ]:[V 5+ ]=1:3, 1:6 and 1:12 has been ascertained. A salt of gross formula 3NaO · Al 2 ) 3 · 12V 2 O 5 · 67H 2 O has been isolated. 3 refs.; 2 figs

  7. Dieta com ácidos graxos poli-insaturados ômega-3 em modelo de Parkinsonismo em ratos expostos à endotoxina bacteriana pré e pós-natal : avaliação comportamental e neuroquímica

    OpenAIRE

    Delattre, Ana Marcia

    2014-01-01

    Orientadora : Profª. Drª. Anete Curte Ferraz Co-orientador : Prof. Dr. Marcelo de M. S. Lima Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Biologia Celular e Molecular. Defesa: Curitiba, 28/08/2014 Inclui referências Área de concentração : Fisiologia Resumo: A doenca de Parkinson (DP) e uma patologia neurodegenerativa complexa que inclui sintomas cognitivos, motores e nao-motores, com fatores etiologicos ainda estu...

  8. SPQR Team Description Paper

    OpenAIRE

    Cherubini , Andrea; Leonetti , M; Marchetti , L; De Luca , A; Iocchi , L; Nardi , D; Oriolo , G; Vendittelli , M

    2008-01-01

    International audience; SPQR is the group of the Faculty of Engineering at Sapienza University of Rome in Italy, that is involved in RoboCup competitions since 1998 in different leagues (Middle-size 1998-2002, Four-legged since 2000, Real-rescue-robots 2003-2006, Virtual-rescue since 2006 and @Home in 2006). In RoboCup 2008, SPQR team will participate in the Standard Platform League with Nao humanoid robots and in the Virtual Rescue League.The team for 2008 is composed by two groups from the C...

  9. The depiction of the Virgin with the Christ in a niche on the western façade of the Church of the Transfiguration in Novgorod and the question of the painter's origin

    Directory of Open Access Journals (Sweden)

    Starodubcev Tatjana

    2010-01-01

    Full Text Available The paper deals with a presentation of the Virgin with the Christ Child, in the niche above the archivolt of the western portal of the Church of the Transfiguration, in Novgorod. The fresco is assumed to have belonged to the painted ensemble in the church narthex, none of which has survived. It is also believed that like Theophanes the Greek, who headed the group painting the naos in the church, the zographos who worked on the decoration of the narthex, had arrived from Constantinople.

  10. Late Holocene climate and environmental change from Asiul cave speleothems: interpretations in light of modern cave monitoring.

    Science.gov (United States)

    Smith, Andrew; Wynn, Peter; Barker, Philip; Leng, Melanie; Noble, Steve; Tych, Wlodek

    2017-04-01

    Northern Iberia offers an excellent location to study fluctuations in North Atlantic Ocean (NA) conditions and the impact that changes in the NA have on atmospheric systems, which dominate Europe's climate. Two speleothems from Cueva de Asiul (Matienzo, N. Spain) have been used to reconstruct rainfall variability in N. Spain throughout the Holocene (Smith et al., 2016a). The carbonate δ18O records from these speleothems are interpreted in the light of a rigorous modern cave monitoring program undertaken at Cueva de Asiul (Smith et al., 2016b). Drip water δ18O reflects a modern rainfall amount effect whilst δ13C appears influenced by Prior Calcite Precipitation (PCP) in the short term and changes in vegetation at long timescales. The speleothem δ18O shows that long duration ( 1500 year) cycles in wetting and drying are prevalent in N. Spain during the Holocene and that dry climate phases are related to the timing of cold events (Bond et al., 2001) in the NA. Here we look in more detail at one of these speleothems, assessing both δ18O and δ13C during the last two thousand years. We show that Cueva de Asiul speleothems not only preserve long duration climate cycles in δ18O, but that they also appear influenced by shorter duration changes in the North Atlantic Oscillation (NAO), in-sync with other NAO archives (Olsen et al., 2012). However, the Cueva de Asiul record does not appear to preserve a predominately positive NAO signal during the Medieval Climate Anomaly (MCA) as is common within many European archives (Trouet et al., 2009), possibly due to the sites' close proximity to the NA and localised oceanic weather systems (Moreno et al., 2012). Alongside climatic changes, the speleothem δ13C shows a clear transition toward higher isotope values around 360 years BP (BP=1950), signalling a major environmental change in the region possibly due to anthropogenic removal of vast swathes of natural forest to support ship building and industry related to the Spanish

  11. Holocene climate aridification trend and human impact interrupted by millennial- and centennial-scale climate fluctuations from a new sedimentary record from Padul (Sierra Nevada, southern Iberian Peninsula)

    Science.gov (United States)

    Ramos-Román, María J.; Jiménez-Moreno, Gonzalo; Camuera, Jon; García-Alix, Antonio; Anderson, R. Scott; Jiménez-Espejo, Francisco J.; Carrión, José S.

    2018-01-01

    Holocene centennial-scale paleoenvironmental variability has been described in a multiproxy analysis (i.e., lithology, geochemistry, macrofossil, and microfossil analyses) of a paleoecological record from the Padul Basin in Sierra Nevada, southern Iberian Peninsula. This sequence covers a relevant time interval hitherto unreported in the studies of the Padul sedimentary sequence. The ˜ 4700-year record has preserved proxies of climate variability, with vegetation, lake levels, and sedimentological change during the Holocene in one of the most unique and southernmost wetlands in Europe. The progressive middle and late Holocene trend toward arid conditions identified by numerous authors in the western Mediterranean region, mostly related to a decrease in summer insolation, is also documented in this record; here it is also superimposed by centennial-scale variability in humidity. In turn, this record shows centennial-scale climate oscillations in temperature that correlate with well-known climatic events during the late Holocene in the western Mediterranean region, synchronous with variability in solar and atmospheric dynamics. The multiproxy Padul record first shows a transition from a relatively humid middle Holocene in the western Mediterranean region to more aridity from ˜ 4700 to ˜ 2800 cal yr BP. A relatively warm and humid period occurred between ˜ 2600 and ˜ 1600 cal yr BP, coinciding with persistent negative North Atlantic Oscillation (NAO) conditions and the historic Iberian-Roman Humid Period. Enhanced arid conditions, co-occurring with overall positive NAO conditions and increasing solar activity, are observed between ˜ 1550 and ˜ 450 cal yr BP (˜ 400 to ˜ 1400 CE) and colder and warmer conditions occurred during the Dark Ages and Medieval Climate Anomaly (MCA), respectively. Slightly wetter conditions took place during the end of the MCA and the first part of the Little Ice Age, which could be related to a change towards negative NAO conditions

  12. Biaxial seismic behaviour of reinforced concrete columns =

    Science.gov (United States)

    Rodrigues, Hugo Filipe Pinheiro

    A analise dos efeitos dos sismos mostra que a investigacao em engenharia sismica deve dar especial atencao a avaliacao da vulnerabilidade das construcoes existentes, frequentemente desprovidas de adequada resistencia sismica tal como acontece em edificios de betao armado (BA) de muitas cidades em paises do sul da Europa, entre os quais Portugal. Sendo os pilares elementos estruturais fundamentais na resistencia sismica dos edificios, deve ser dada especial atencao a sua resposta sob acoes ciclicas. Acresce que o sismo e um tipo de acao cujos efeitos nos edificios exige a consideracao de duas componentes horizontais, o que tem exigencias mais severas nos pilares comparativamente a acao unidirecional. Assim, esta tese centra-se na avaliacao da resposta estrutural de pilares de betao armado sujeitos a acoes ciclicas horizontais biaxiais, em tres linhas principais. Em primeiro lugar desenvolveu-se uma campanha de ensaios para o estudo do comportamento ciclico uniaxial e biaxial de pilares de betao armado com esforco axial constante. Para tal foram construidas quatro series de pilares retangulares de betao armado (24 no total) com diferentes caracteristicas geometricas e quantidades de armadura longitudinal, tendo os pilares sido ensaiados para diferentes historias de carga. Os resultados experimentais obtidos sao analisados e discutidos dando particular atencao a evolucao do dano, a degradacao de rigidez e resistencia com o aumento das exigencias de deformacao, a energia dissipada, ao amortecimento viscoso equivalente; por fim e proposto um indice de dano para pilares solicitados biaxialmente. De seguida foram aplicadas diferentes estrategias de modelacao nao-linear para a representacao do comportamento biaxial dos pilares ensaiados, considerando nao-linearidade distribuida ao longo dos elementos ou concentrada nas extremidades dos mesmos. Os resultados obtidos com as varias estrategias de modelacao demonstraram representar adequadamente a resposta em termos das curvas

  13. Flood frequency analysis of historical flood data under stationary and non-stationary modelling

    Science.gov (United States)

    Machado, M. J.; Botero, B. A.; López, J.; Francés, F.; Díez-Herrero, A.; Benito, G.

    2015-06-01

    Historical records are an important source of information on extreme and rare floods and fundamental to establish a reliable flood return frequency. The use of long historical records for flood frequency analysis brings in the question of flood stationarity, since climatic and land-use conditions can affect the relevance of past flooding as a predictor of future flooding. In this paper, a detailed 400 yr flood record from the Tagus River in Aranjuez (central Spain) was analysed under stationary and non-stationary flood frequency approaches, to assess their contribution within hazard studies. Historical flood records in Aranjuez were obtained from documents (Proceedings of the City Council, diaries, chronicles, memoirs, etc.), epigraphic marks, and indirect historical sources and reports. The water levels associated with different floods (derived from descriptions or epigraphic marks) were computed into discharge values using a one-dimensional hydraulic model. Secular variations in flood magnitude and frequency, found to respond to climate and environmental drivers, showed a good correlation between high values of historical flood discharges and a negative mode of the North Atlantic Oscillation (NAO) index. Over the systematic gauge record (1913-2008), an abrupt change on flood magnitude was produced in 1957 due to constructions of three major reservoirs in the Tagus headwaters (Bolarque, Entrepeñas and Buendia) controlling 80% of the watershed surface draining to Aranjuez. Two different models were used for the flood frequency analysis: (a) a stationary model estimating statistical distributions incorporating imprecise and categorical data based on maximum likelihood estimators, and (b) a time-varying model based on "generalized additive models for location, scale and shape" (GAMLSS) modelling, which incorporates external covariates related to climate variability (NAO index) and catchment hydrology factors (in this paper a reservoir index; RI). Flood frequency

  14. Post harvest changes gamma-irradiated banana Prata; Modificações pós-colheita de banana 'prata' y-irradiada

    Energy Technology Data Exchange (ETDEWEB)

    Vilas Boas, E.V. de; Chitarra, A. B.; Chitarra, M. I.F.

    1996-09-15

    The effect of the gamma-irradiation was evaluated at 0.25 and 0.50 kGy, on the development of peel coloration, CO{sub 2} and ethylene evolution, conversion of starch to sugars, pulp-to-peel ratio, pectic solubilization and activities of enzymes of the cell wall, pectin methylesterase (PME), and polygalacturonase (PG), during maturation of 'Prata' bananas. The gamma-irradiation did not affect the normal colour development of the fruits. An increase in the ethylene peak and a decrease in the CO{sub 2} peak was observed. The gamma-irradiation did not affect the degradation of starch, while a delay in soluble sugar accumulation was noted on the 6 and 7 colour grades. The fruits subjected to 0.25 kGy had the highest increase in the pulp-to-peel relation, beginning with colour grade 5, due to a possible stress effect of that dose. An increase of pectin solubilization was observed. Higher PME activities were exhibited by irradiated fruits, although the gamma-irradiation suppressed the PG activity throughout the maturation period. The gamma-irradiation did not extend the post-harvest life of 'Prata' bananas. (author) [Portuguese] Avaliou-se o efeito da radiacao y a 0,25 e 0,50 kGy sobre o desenvolvimento da coloracao da casca da banana, a evolucao de etileno e CO{sub 2} a conversao de amido em acucares, a relacao polpa/casca, a solubilizacao pectica e as atividades das enzimas relacionadas a degradacao da parede celular, a pectinametilesterase (PMF) e poligalacturonase (PG), na polpa da banana 'prata' durante sua maturacao. A radiacao y nao afetou o desenvolvimento normal da coloracao da casca; entretanto, incrementou o pico de etileno e reduziu o pico de CO{sub 2}. A radiacao y nao afetou a degradacao do amido, mas determinou um efeito retardador sobre o acumulo de acucares soluveis totais na polpa, nos graus 6 e 7 de coloracao da casca. A dose 0,25 kGy determinou o maior incremento na relacao polpa/casca, a partir do grau 5 de coloracao, resultado de um possivel efeito

  15. Uncertainty in wave energy resource assessment. Part 2: Variability and predictability

    International Nuclear Information System (INIS)

    Mackay, Edward B.L.; Bahaj, AbuBakr S.; Challenor, Peter G.

    2010-01-01

    The uncertainty in estimates of the energy yield from a wave energy converter (WEC) is considered. The study is presented in two articles. The first article considered the accuracy of the historic data and the second article, presented here, considers the uncertainty which arises from variability in the wave climate. Mean wave conditions exhibit high levels of interannual variability. Moreover, many previous studies have demonstrated longer-term decadal changes in wave climate. The effect of interannual and climatic changes in wave climate on the predictability of long-term mean WEC power is examined for an area off the north coast of Scotland. In this location anomalies in mean WEC power are strongly correlated with the North Atlantic Oscillation (NAO) index. This link enables the results of many previous studies on the variability of the NAO and its sensitivity to climate change to be applied to WEC power levels. It is shown that the variability in 5, 10 and 20 year mean power levels is greater than if annual power anomalies were uncorrelated noise. It is also shown that the change in wave climate from anthropogenic climate change over the life time of a wave farm is likely to be small in comparison to the natural level of variability. Finally, it is shown that despite the uncertainty related to variability in the wave climate, improvements in the accuracy of historic data will improve the accuracy of predictions of future WEC yield. (author)

  16. Warm Arctic—cold continents: climate impacts of the newly open Arctic Sea

    Directory of Open Access Journals (Sweden)

    James E. Overland

    2011-12-01

    Full Text Available Recent Arctic changes are likely due to coupled Arctic amplification mechanisms with increased linkage between Arctic climate and sub-Arctic weather. Historically, sea ice grew rapidly in autumn, a strong negative radiative feedback. But increased sea-ice mobility, loss of multi-year sea ice, enhanced heat storage in newly sea ice-free ocean areas, and modified wind fields form connected positive feedback processes. One-way shifts in the Arctic system are sensitive to the combination of episodic intrinsic atmospheric and ocean variability and persistent increasing greenhouse gases. Winter 2009/10 and December 2010 showed a unique connectivity between the Arctic and more southern weather patterns when the typical polar vortex was replaced by high geopotential heights over the central Arctic and low heights over mid-latitudes that resulted in record snow and low temperatures, a warm Arctic—cold continents pattern. The negative value of the winter (DJF 2009/10 North Atlantic Oscillation (NAO index associated with enhanced meridional winds was the lowest observed value since the beginning of the record in 1865. Wind patterns in December 2007 and 2008 also show an impact of warmer Arctic temperatures. A tendency for higher geopotential heights over the Arctic and enhanced meridional winds are physically consistent with continued loss of sea ice over the next 40 years. A major challenge is to understand the interaction of Arctic changes with climate patterns such as the NAO, Pacific North American and El Niño–Southern Oscillation.

  17. Biomarker records of Holocene climate variations in Asian interior

    Science.gov (United States)

    Song, M.; Liu, Z.; Liu, W.; Zhao, C.; Li, S.; He, Y.

    2012-12-01

    Understanding Holocene climate fluctuation may provide clues to projection of future climate change. Lake sediments in the arid central Asia (ACA), as an archive of past climate information, keep attracting considerable interest. We have retrieved several sediment cores from Lake Manas, an endorheic lake in Zunggar desert, Xinjiang Province, China. Biomarker proxies including alkenone Uk'37, %C37:4 and C37 concentration (C37 Conc), and physical proxies including density and magnetic susceptibility (MS) have been analyzed. We have found substantial climatic and environmental changes during the late Holocene. Density, MS and Uk'37 values are high during Medieval Warm Period (MWP) and C37 Conc is very low. During the Little Ice Age, density and MS decrease, Uk'37 values drop to near 0.1, C37 Conc is increased by 2 to 3 magnitude. Thus, warm and dry conditions dominated MWP while cold and wet conditions dominated LIA, a typical "Westerly" pattern which is opposite to the hydrological variation in Asian monsoonal regions. Biomarker records' correlation with solar irradiance (SI), the North Atlantic Oscillation (NAO), the 1000year ACA Moisture Index (ACAM), and the North Hemisphere Temperature (NHT) suggests SI as one of the forcing factor on temperature fluctuation and cold and wet LIA possibly resulting from westerly-jet shift, negative NAO oscillation and the lower evaporation induced by the decrease of temperature. Biomarker records for the whole Holocene will be also presented.

  18. Large-scale climate variation modifies the winter grouping behavior of endangered Indiana bats

    Science.gov (United States)

    Thogmartin, Wayne E.; McKann, Patrick C.

    2014-01-01

    Power laws describe the functional relationship between 2 quantities, such as the frequency of a group as the multiplicative power of group size. We examined whether the annual size of well-surveyed wintering populations of endangered Indiana bats (Myotis sodalis) followed a power law, and then leveraged this relationship to predict whether the aggregation of Indiana bats in winter was influenced by global climate processes. We determined that Indiana bat wintering populations were distributed according to a power law (mean scaling coefficient α = −0.44 [95% confidence interval {95% CI} = −0.61, −0.28). The antilog of these annual scaling coefficients ranged between 0.67 and 0.81, coincident with the three-fourths power found in many other biological phenomena. We associated temporal patterns in the annual (1983–2011) scaling coefficient with the North Atlantic Oscillation (NAO) index in August (βNAOAugust = −0.017 [90% CI = −0.032, −0.002]), when Indiana bats are deciding when and where to hibernate. After accounting for the strong effect of philopatry to habitual wintering locations, Indiana bats aggregated in larger wintering populations during periods of severe winter and in smaller populations in milder winters. The association with August values of the NAO indicates that bats anticipate future winter weather conditions when deciding where to roost, a heretofore unrecognized role for prehibernation swarming behavior. Future research is needed to understand whether the three-fourths–scaling patterns we observed are related to scaling in metabolism.

  19. Spatiotemporal Distribution of Droughts in the Xijiang River Basin, China and Its Responses to Global Climatic Events

    Directory of Open Access Journals (Sweden)

    Jizhong Qiu

    2017-04-01

    Full Text Available The Xijiang River is a main branch of the Pearl River, the largest river in South China. Droughts in this area have seriously influenced local water resource utilization, and socio-economic development. The spatiotemporal distribution of droughts and its responses to global climatic events are of critical significance for the assessment and early warning of drought disasters. In this paper, the spatiotemporal patterns of droughts characterized by Rotated Empirical Orthogonal Function/Rotated Principal Components (REOF/RPC in the Xijiang River Basin, China were evaluated using the Self-calibrated Palmer Drought Severity Index (Sc-PDSI. The drought responses to El Niño/Southern Oscillation (ENSO, Pacific Decadal Oscillation (PDO, India Ocean Dipole (IOD, and North Atlantic Oscillation (NAO were analysed by Pearson correlation and multiple stepwise regression. The results showed that one year earlier NAO was the dominant factor impacting the droughts in the Xijiang Basin. Its contribution for the RPC2s of the annual, the first and second half years, winter, summer, autumn, and February were −0.556, −0.419, 0.597, −0.447, 0.542, 0.600, and −0.327, respectively. Besides the two adjacent Pacific and India oceans, the droughts seem be influenced by distant Atlantic climatic events. These results offer new reference insights into the early warning of droughts as well as the planning and management of water resources in the study area.

  20. Climate changes over the past millennium: Relationships with Mediterranean climates

    International Nuclear Information System (INIS)

    Mann, M.E.

    2006-01-01

    Evidence is reviewed for climate change and its causes over the interval spanning roughly the past millennium. Particular emphasis is placed on patterns of climate change influencing Mediterranean climates of the Northern Hemisphere. The evidence is taken from studies using high-resolution climate proxy data sources, and climate modeling simulations. The available evidence suggests that forced changes in dynamical modes of variability including the North Atlantic Oscillation (NAO) and El Nino/Southern Oscillation (ENSO) have played a key role in the patterns of climate variability in Mediterranean regions over the past millennium

  1. Robots humains, avez-donc une réalité ?

    OpenAIRE

    Amblard , Maxime; Boumaza , Amine

    2015-01-01

    International audience; Plusieurs laboratoires dans le monde travaillent à la création de robots humanoïdes . La technologie ayant considérablement évolué, il apparaît réaliste d’imaginer un quotidien accompagné de tels systèmes, à l’image du robot Nao, dont on discute encore comment lui faire partager des émotions pour simuler un comportement humain. Mais finalement, les robots sont déjà partout et depuis longtemps, dans les usines, les jouets électroniques, nos ordinateurs, nos tablettes, l...

  2. Application of the Na+ recirculation theory to ion coupled water transport in low- and high resistance osmoregulatory epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Møbjerg, Nadja; Nielsen, Robert

    2007-01-01

    approaches: (i) An isotope tracer method in small intestine. Simultaneous measurement of water flow and ion transport in toad skin epithelium demonstrating, (ii) occasional hyposmotic absorbates, and (iii) reduced fluid absorption in the presence of serosal bumetanide. (iv) Studies of the metabolic cost......, the residual hydraulic permeability in proximal tubule of AQP1(-/-) mice, the adverse relationship between hydraulic permeability and the concentration difference needed to reverse transepithelial water flow, and in a non-contradictory way the wide range of metabolic efficiencies from above to below 18 Na+/O2...

  3. Utilização de metodologias para a análise térmica de um sistema de aquecimento de água solar industrial

    OpenAIRE

    Parente Lima, Thiago

    2010-01-01

    Alem do uso doméstico, a energia solar possui amplo potencial de aplicação em processos industriais. Hoje a maioria desses processos utiliza como fonte energetica combustíveis nao renováveis ou biomassa, cuja queima provoca os impactos ambientais já conhecidos. A utilização ao da energia solar pode reduzir a dependência do uso desses combustíveis e os seus conseqüentes impactos ao meio ambiente. O objetivo desse trabalho é fazer um estudo de viabilidade técnicoeconômica de um sistema...

  4. Non-aqueous Li- and Na-O2 batteries: Study and analysis of electrochemical processes

    OpenAIRE

    Landa Medrano, Imanol

    2016-01-01

    222 p. Las baterías M-oxígeno, siendo M un metal alcalino, son conocidas por su extraordinaria densidad energética teórica. En esta tesis se estudian en detalle las reacciones que tienen lugar en las baterías de litio y de sodio a fin de comprender su complejo funcionamiento. Para ello se emplean múltiples técnicas de caracterización, tanto electroquímica como de materiales. Una vez comprendido su funcionamiento, se proponen rutas y estrategias alternativas en el proceso de reducción y oxi...

  5. Influence of morphology of ceramic fibers in catalytic combustion of methane; Influencia da morfologia de fibras ceramicas na combustao catalitica do metano

    Energy Technology Data Exchange (ETDEWEB)

    Tabarelli, A.C.; Alves, A.K.; Bergmann, C.P., E-mail: andretabarelli@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Departamento de Materiais

    2012-07-01

    Methane, considered as the main constituent of natural gas has been widely used as an energy source. During its combustion are produced pollutants that cause concern and necessity to eliminate or reduce the emission of these agents in the atmosphere. One of the main means of controlling emissions is the use of catalysts. In order to contribute to the development of new catalysts, this study analyzed the morphology of ceramic fibers of cerium oxide (ceria) doped with copper fabricated by electrospinning, in order to verify their effects on catalytic activity. Parameters were varied in distance from the electrodes, the diameter of the capillary and applied voltage between electrodes. The characterizations were performed: scanning electron microscopy, thermogravimetric analysis, BET and Xray diffraction (DXR). The results indicate that after the thermal treatment there was a reduction of approximately 40% fiber diameter and specific surface area ranging between 28.929 and 34.501 m{sup 2}/g. (author)

  6. Hydrogen production from catalytic decomposition of methane; Produccion de hidrogeno a partir de la descomposicion termica catalitica del biogas de digestion anaerobia

    Energy Technology Data Exchange (ETDEWEB)

    Belsue Echevarria, M.; Etxebeste Juarez, O.; Perez Gil, S.

    2002-07-01

    The need of substitution of part of the energy obtained from fossil fuels instead of energy from renewable sources, together with the minimal emissions of CO{sub ''} and CO that are expected with these technologies, make renewable sources a very attractive predecessor for the production of hydrogen. In this situation, a usable source for hydrogen production is the biogas achieved by means of technologies like the anaerobic digestion of different kinds of biomass (MSW, sewage sludge, stc.). In this article we suggest the Thermal Catalytic Decomposition of the methane contained in this biogas, after separation of pollutants like CO{sub ''}, H{sub 2}S. steam. This technology will give hydrogen, usable in fuel cells, and nanoestructured carbon as products. (Author) 7 refs.

  7. Untangling Trends and Drivers of Changing River Discharge Along Florida's Gulf Coast

    Science.gov (United States)

    Glodzik, K.; Kaplan, D. A.; Klarenberg, G.

    2017-12-01

    Along the relatively undeveloped Big Bend coastline of Florida, discharge in many rivers and springs is decreasing. The causes are unclear, though they likely include a combination of groundwater extraction for water supply, climate variability, and altered land use. Saltwater intrusion from altered freshwater influence and sea level rise is causing transformative ecosystem impacts along this flat coastline, including coastal forest die-off and oyster reef collapse. A key uncertainty for understanding river discharge change is predicting discharge from rainfall, since Florida's karstic bedrock stores large amounts of groundwater, which has a long residence time. This study uses Dynamic Factor Analysis (DFA), a multivariate data reduction technique for time series, to find common trends in flow and reveal hydrologic variables affecting flow in eight Big Bend rivers since 1965. The DFA uses annual river flows as response time series, and climate data (annual rainfall and evapotranspiration by watershed) and climatic indices (El Niño Southern Oscillation [ENSO] Index and North Atlantic Oscillation [NAO] Index) as candidate explanatory variables. Significant explanatory variables (one evapotranspiration and three rainfall time series) explained roughly 50% of discharge variation across rivers. Significant trends (representing unexplained variation) were shared among rivers, with geographical grouping of five northern rivers and three southern rivers, along with a strong downward trend affecting six out of eight systems. ENSO and NAO had no significant impact. Advancing knowledge of these dynamics is necessary for forecasting how altered rainfall and temperatures from climate change may impact flows. Improved forecasting is especially important given Florida's reliance on groundwater extraction to support its growing population.

  8. Spatio-temporal modelling of zero-inflated deep-sea shrimp data by Tweedie generalized additive

    Directory of Open Access Journals (Sweden)

    Simona Arcuti

    2013-10-01

    Full Text Available In theMediterrean Sea the population features of demersal resources fluctuate over spatial and temporal scales due to the variability of abiotic and biotic factors as well as to human activities. The two shrimps Parapenaeus longirostris and Aristaeomorpha foliacea are among the most important deep-sea demersal resources in the North-Western Ionian Sea. Their changes in terms of density, biomass andmedian length induced by anthropogenic and environmental variables (fishing effort, sea surface temperature, precipitations, Winter North Atlantic Oscillation (NAO and Annual MediterraneanOscillation (MO indices were investigated. Biological data were collected during trawl surveys carried out from 1995 to 2006 as part of the international program MEDITS (International Bottom Trawl Survey in the Mediterranean. Generalized AdditiveModels were used to evaluate the spatio-temporal variation of both species, together with the possible nonlinear effects of biotic and abiotic factors. Density and biomass were assumed to be distributed according to a member of the Tweedie family in order to account for zero-inflation in the relative data. Spacetime interaction was consideredwithin a non-separablemodel with smooth spatio-temporal component based on tensor product splines. The results show significant spatio-temporal and depth effects in the three population parameters of these resources. Winter NAO index significantly influenced the density, biomass and length of P. longirostris. Sea surface temperature significantly influenced the size of this species and the three population features of A. foliacea. The size of this shrimp resulted also influenced negatively by fishing effort and positively by the MO index.

  9. Understanding the North Atlantic Oscillation and Its Effects in the Mediterranean

    Science.gov (United States)

    Trigo, Ricardo M.; Serrano, Sergio M. Vicente

    2010-11-01

    ESF-MedCLIVAR Workshop on Hydrological, Socioeconomic and Ecological Impacts of the North Atlantic Oscillation in the Mediterranean; Zaragoza, Spain, 24-27 May 2010; According to the latest Intergovernmental Panel on Climate Change report, the Mediterranean basin represents one of the most important hot spots of climate change in the world, with recent trends toward a hotter and drier climate being related to changes in atmospheric circulation patterns. Among these patterns the North Atlantic Oscillation (NAO) is the most important one and the only one that exerts a clear influence throughout the year, although with stronger intensity and extension during winter. In the framework of the European Science Foundation's Mediterranean Climate Variability and Predictability (MedCLIVAR) program (http://www.medclivar.eu/), a thematic workshop devoted to the hydrological, socioeconomic, and ecological impacts of the NAO in the Mediterranean area was held in Spain. The main objective of this 3-day workshop was to foster interaction in this increasingly interdisciplinary topic, in particular, among climatologists, hydrologists, geographers, agronomists, biologists, and other scientists. The workshop was attended by 62 participants from 15 different countries and included a mix of senior scientists and graduate students. The workshop was divided into five sessions focusing on (1) natural hazards, including droughts, severe precipitations, floods, heat waves, and cold spells; (2) vegetation activity and agriculture production; (3) natural ecosystems and environment, including forest dynamics, fisheries, dynamics of animal populations, and air quality; (4) geomorphology, including landslides and debris flows, erosivity mechanisms, and surface erosion processes; and (5) renewable energies production, including hydraulic, eolic, and solar.

  10. Analysing the teleconnection systems affecting the climate of the Carpathian Basin

    Science.gov (United States)

    Kristóf, Erzsébet; Bartholy, Judit; Pongrácz, Rita

    2017-04-01

    Nowadays, the increase of the global average near-surface air temperature is unequivocal. Atmospheric low-frequency variabilities have substantial impacts on climate variables such as air temperature and precipitation. Therefore, assessing their effects is essential to improve global and regional climate model simulations for the 21st century. The North Atlantic Oscillation (NAO) is one of the best-known atmospheric teleconnection patterns affecting the Carpathian Basin in Central Europe. Besides NAO, we aim to analyse other interannual-to-decadal teleconnection patterns, which might have significant impacts on the Carpathian Basin, namely, the East Atlantic/West Russia pattern, the Scandinavian pattern, the Mediterranean Oscillation, and the North-Sea Caspian Pattern. For this purpose primarily the European Centre for Medium-Range Weather Forecasts' (ECMWF) ERA-20C atmospheric reanalysis dataset and multivariate statistical methods are used. The indices of each teleconnection pattern and their correlations with temperature and precipitation will be calculated for the period of 1961-1990. On the basis of these data first the long range (i. e. seasonal and/or annual scale) forecast ability is evaluated. Then, we aim to calculate the same indices of the relevant teleconnection patterns for the historical and future simulations of Coupled Model Intercomparison Project Phase 5 (CMIP5) models and compare them against each other using statistical methods. Our ultimate goal is to examine all available CMIP5 models and evaluate their abilities to reproduce the selected teleconnection systems. Thus, climate predictions for the 21st century for the Carpathian Basin may be improved using the best-performing models among all CMIP5 model simulations.

  11. Understanding long-term fruit fly (Diptera: Tephritidae) population dynamics: implications for areawide management.

    Science.gov (United States)

    Aluja, Martín; Ordano, Mariano; Guillén, Larissa; Rull, Juan

    2012-06-01

    Fruit flies (Diptera: Tephritidae) are devastating agricultural pests worldwide but studies on their long-term population dynamics are sparse. Our aim was to determine the mechanisms driving long-term population dynamics as a prerequisite for ecologically based areawide pest management. The population density of three pestiferous Anastrepha species [Anastrepha ludens (Loew), Anastrepha obliqua (Macquart), and Anastrepha serpentina (Wiedemann)] was determined in grapefruit (Citrus x paradisi Macfad.), mango (Mangifera indica L.), and sapodilla [Manilkara zapota (L.) P. Royen] orchards in central Veracruz, México, on a weekly basis over an 11-yr period. Fly populations exhibited relatively stable dynamics over time. Population dynamics were mainly driven by a direct density-dependent effect and a seasonal feedback process. We discovered direct and delayed influences that were correlated with both local (rainfall and air temperature) and global climatic variation (El Niño Southern Oscillation [ENSO] and North Atlantic Oscillation [NAO]), and detected differences among species and location of orchards with respect to the magnitude and nature (linear or nonlinear) of the observed effects, suggesting that highly mobile pest outbreaks become uncertain in response to significant climatic events at both global and local levels. That both NAO and ENSO affected Anastrepha population dynamics, coupled with the high mobility of Anastrepha adults and the discovery that when measured as rate of population change, local population fluctuations exhibited stable dynamics over time, suggests potential management scenarios for the species studied lie beyond the local scale and should be approached from an areawide perspective. Localized efforts, from individual growers will probably prove ineffective, and nonsustainable.

  12. Effects of local and large-scale climate patterns on estuarine resident fishes: The example of Pomatoschistus microps and Pomatoschistus minutus

    Science.gov (United States)

    Nyitrai, Daniel; Martinho, Filipe; Dolbeth, Marina; Rito, João; Pardal, Miguel A.

    2013-12-01

    Large-scale and local climate patterns are known to influence several aspects of the life cycle of marine fish. In this paper, we used a 9-year database (2003-2011) to analyse the populations of two estuarine resident fishes, Pomatoschistus microps and Pomatoschistus minutus, in order to determine their relationships with varying environmental stressors operating over local and large scales. This study was performed in the Mondego estuary, Portugal. Firstly, the variations in abundance, growth, population structure and secondary production were evaluated. These species appeared in high densities in the beginning of the study period, with subsequent occasional high annual density peaks, while their secondary production was lower in dry years. The relationships between yearly fish abundance and the environmental variables were evaluated separately for both species using Spearman correlation analysis, considering the yearly abundance peaks for the whole population, juveniles and adults. Among the local climate patterns, precipitation, river runoff, salinity and temperature were used in the analyses, and North Atlantic Oscillation (NAO) index and sea surface temperature (SST) were tested as large-scale factors. For P. microps, precipitation and NAO were the significant factors explaining abundance of the whole population, the adults and the juveniles as well. Regarding P. minutus, for the whole population, juveniles and adults river runoff was the significant predictor. The results for both species suggest a differential influence of climate patterns on the various life cycle stages, confirming also the importance of estuarine resident fishes as indicators of changes in local and large-scale climate patterns, related to global climate change.

  13. Steric and mass-induced Mediterranean sea level trends from 14 years of altimetry data

    Science.gov (United States)

    Criado-Aldeanueva, Francisco; Del Río Vera, Jorge; García-Lafuente, Jesús

    2008-02-01

    Long-term series of almost 14 years of altimetry data (1992-2005) have been analysed along with Sea Surface Temperature (SST) and temperature and salinity profiles to investigate sea level trends over the Mediterranean Sea. Although sea level variations are mainly driven by the steric contribution, the mass-induced component plays some role in modulating its oscillation. A spatially averaged positive trend of 2.1 ± 0.6 mm/year has been observed, but a change in sign in 2001 seems to appear. Steric effects (mainly on thermal origin) account for ˜ 55% of sea level trend. Although Mediterranean Sea is a semi-enclosed basin, this value is comparable to that reported for the global ocean. Sea level rise is particularly important in the Levantine basin south of Crete with values up to 10 ± 1 mm/year. Other areas of sea level rise are localised throughout the Levantine basin and in the Adriatic and Alboran Seas, with more moderate values. Sea level drop areas are localised in the Algerian basin, between the Balearic Islands and the African coasts and, particularly, in the Ionian basin. In this area, negative trends as high as - 10 ± 0.8 mm/year are detected mainly due to the mass-induced contribution, which suggests decadal changes of surface circulation. The inferred sea level trends have been correlated with North Atlantic Oscillation (NAO) indices and a low but significant correlation has been detected between sea level in the Levantine and Balearic basins and NAO index.

  14. Sub-decadal- to decadal-scale climate cyclicity during the Holsteinian interglacial (MIS 11 evidenced in annually laminated sediments

    Directory of Open Access Journals (Sweden)

    A. Koutsodendris

    2011-09-01

    Full Text Available To unravel the short-term climate variability during Marine Isotope Stage (MIS 11, which represents a close analogue to the Holocene with regard to orbital boundary conditions, we performed microfacies and time series analyses on a ~3200-yr-long record of annually laminated Holsteinian lake sediments from Dethlingen, northern Germany. These biogenic varves comprise two sub-layers: a light sub-layer, which is controlled by spring/summer diatom blooms, and a dark sub-layer consisting mainly of amorphous organic matter and fragmented diatom frustules deposited during autumn/winter. Time series analyses were performed on the thickness of the light and dark sub-layers. Signals exceeding the 95% and 99% confidence levels occur at periods that are near-identical to those known from modern instrumental data and Holocene palaeoclimatic records. Spectral peaks at periods of 90, 25, and 10.5 yr are likely associated with the 88-, 22- and 11-yr solar cycles, respectively. This variability is mainly expressed in the light sub-layer spectra, suggesting solar influence on the palaeoproductivity of the lake. Significant signals at periods between 3 and 5 yr and at ∼6 yr are strongest expressed in the dark sub-layer spectra and may reflect an influence of the El Niño-Southern Oscillation (ENSO and the North Atlantic Oscillation (NAO during autumn/winter. Our results suggest that solar forcing and ENSO/NAO-like variability influenced central European climate during MIS 11 similarly to the present interglacial, thus demonstrating the comparability of the two interglacial periods at sub-decadal to decadal timescales.

  15. Predictability and possible earlier awareness of extreme precipitation across Europe

    Science.gov (United States)

    Lavers, David; Pappenberger, Florian; Richardson, David; Zsoter, Ervin

    2017-04-01

    Extreme hydrological events can cause large socioeconomic damages in Europe. In winter, a large proportion of these flood episodes are associated with atmospheric rivers, a region of intense water vapour transport within the warm sector of extratropical cyclones. When preparing for such extreme events, forecasts of precipitation from numerical weather prediction models or river discharge forecasts from hydrological models are generally used. Given the strong link between water vapour transport (integrated vapour transport IVT) and heavy precipitation, it is possible that IVT could be used to warn of extreme events. Furthermore, as IVT is located in extratropical cyclones, it is hypothesized to be a more predictable variable due to its link with synoptic-scale atmospheric dynamics. In this research, we firstly provide an overview of the predictability of IVT and precipitation forecasts, and secondly introduce and evaluate the ECMWF Extreme Forecast Index (EFI) for IVT. The EFI is a tool that has been developed to evaluate how ensemble forecasts differ from the model climate, thus revealing the extremeness of the forecast. The ability of the IVT EFI to capture extreme precipitation across Europe during winter 2013/14, 2014/15, and 2015/16 is presented. The results show that the IVT EFI is more capable than the precipitation EFI of identifying extreme precipitation in forecast week 2 during forecasts initialized in a positive North Atlantic Oscillation (NAO) phase. However, the precipitation EFI is superior during the negative NAO phase and at shorter lead times. An IVT EFI example is shown for storm Desmond in December 2015 highlighting its potential to identify upcoming hydrometeorological extremes.

  16. Ex-Votos às Ninfas em Portugal

    OpenAIRE

    Joaquim Rodrigues dos SANTOS JUNIOR; Mario CARDOZO

    2009-01-01

    A expansào na Península Hispánica dos cultos consagrados às divindades do Panteáo romano, revelada em numerosos textos epigráficos dedicados a Júpiter, Diana, Minerva, Juno, Marte, Cerei, etcétera, e bem assim dos cultos de origem oriental que as relaçôes militares, comerciáis e políticas do Imperio com os povos da Asia e de África haviam introduzido em Roma —cultos a Se rapis, I sis, Cibele, Mitra, etc.— nao logrou dissipar, na religiosidade ancestral do íncola do Ocidente, os cultos que, an...

  17. Optical Observations of M81 Galaxy Group in Narrow Band [SII] and H_alpha Filters: Holmberg IX

    Directory of Open Access Journals (Sweden)

    Arbutina, B.

    2009-12-01

    Full Text Available We present observations of the nearby tidal dwarf galaxy Holmberg IX in M81 galaxy group in narrow band [SII] and H$alpha$ filters, carried out in March and November 2008 with the 2m RCC telescope at NAO Rozhen, Bulgaria. Our search for resident supernova remnants (identified as sources with enhanced [SII] emission relative to their H$alpha$ emission in this galaxy yielded no sources of this kind, besides M&H 10-11 or HoIX X-1. Nevertheless, we found a number of objects with significant H$alpha$ emission that probably represent uncatalogued HII regions.

  18. Observations of the Galaxy NGC 3077 in the Narrow-Band [S II] and Hα Filters

    Directory of Open Access Journals (Sweden)

    Andjelić M.

    2011-09-01

    Full Text Available We present observations of the H I tidal arm near a dwarf galaxy NGC 3077 (member of the M81 galaxy group in the narrow-band [S II] and Hα filters. Observations were carried out in 2011 March with the 2 m RCC telescope at the NAO Rozhen, Bulgaria. Our search for possible supernova remnant candidates (identified as sources with enhanced [S II] emission relative to their Hα emission in this region yielded no sources of this kind. Nevertheless, we found a number of objects with significant Hα emission that probably represent uncatalogued, low brightness H II regions.

  19. Reactions of vanadium(5) with aluminium(3) in weakly acid aqueous solutions; Vzaimodejstvie mezhdu vanadiem(5) i alyhminiem(3) v slabokislykh vodnykh rastvorakh

    Energy Technology Data Exchange (ETDEWEB)

    Ditrikh, I V; Makhno, A Ya [Donetskij Gosudarstvennyj Univ., Donetsk (Ukraine)

    1997-12-31

    Conditions of vanadium(5) heteropolycompounds formation in aqueous solutions containing aluminium(3) have been studied. By the methods of potentiometry and conductometry in solutions of Al(NO{sub 3}){sub 3}-NaVO{sub 3} salt mixture the formation of complexes with the ratios [Al{sup 3+}]:[V{sup 5+}]=1:3, 1:6 and 1:12 has been ascertained. A salt of gross formula 3NaO {center_dot} (Al{sub 2}){sub 3} {center_dot} 12V{sub 2}O{sub 5} {center_dot} 67H{sub 2}O has been isolated. 3 refs.; 2 figs.

  20. Climate variability in West Greenland during the past 1500 years

    DEFF Research Database (Denmark)

    dos Santos Ribeiro, Sofia Isabel; Moros, Matthias; Ellegaard, Marianne

    2012-01-01

    -surface temperatures in Disko Bay are out-of-phase with Greenland ice-core reconstructed temperatures and marine proxy data from South and East Greenland. This is probably governed by an NAO-type pattern, which results in warmer sea-surface conditions with less extensive sea ice in the area for the later part....... Sea ice cover and primary productivity were identified as the two main factors driving dinoflagellate cyst community changes through time. Our data provide evidence for an opposite climate trend in West Greenland relative to the NE Atlantic region from c. AD 500 to 1050. For the same period, sea...

  1. Hierarchical Chitin Fibers with Aligned Nanofibrillar Architectures: A Nonwoven-Mat Separator for Lithium Metal Batteries.

    Science.gov (United States)

    Kim, Joong-Kwon; Kim, Do Hyeong; Joo, Se Hun; Choi, Byeongwook; Cha, Aming; Kim, Kwang Min; Kwon, Tae-Hyuk; Kwak, Sang Kyu; Kang, Seok Ju; Jin, Jungho

    2017-06-27

    Here, we introduce regenerated fibers of chitin (Chiber), the second most abundant biopolymer after cellulose, and propose its utility as a nonwoven fiber separator for lithium metal batteries (LMBs) that exhibits an excellent electrolyte-uptaking capability and Li-dendrite-mitigating performance. Chiber is produced by a centrifugal jet-spinning technique, which allows a simple and fast production of Chibers consisting of hierarchically aligned self-assembled chitin nanofibers. Following the scrutinization on the Chiber-Li-ion interaction via computational methods, we demonstrate the potential of Chiber as a nonwoven mat-type separator by monitoring it in Li-O 2 and Na-O 2 cells.

  2. Crystal Structure of the Sodium Cobaltate Deuterate Superconductor NaxCoO2o4xD2O (x=1/3)

    OpenAIRE

    Jorgensen, J. D.; Avdeev, M.; Hinks, D. G.; Burley, J. C.; Short, S.

    2003-01-01

    Neutron and x-ray powder diffraction have been used to investigate the crystal structures of a sample of the newly-discovered superconducting sodium cobaltate deuterate compound with composition Na0.31(3)CoO2o1.25(2)D2O and its anhydrous parent compound Na0.61(1)CoO2. The deuterate superconducting compound is formed by coordinating four D2O molecules (two above and two below) to each Na ion in a way that gives Na-O distances nearly equal to those in the parent compound. One deuteron of the D2...

  3. Recomendações para acessibilidade aos surdos de auxílio aos designers na criação e na implementação de ambientes web

    OpenAIRE

    Silva, Rafaella Aline Lopes da

    2013-01-01

    Resumo: A Internet proporciona inúmeras vantagens em relação à sua utilização como meio de comunicação e socialização, porem o conteúdo web nao e acessível a contento para todos os perfis de usuario [10]. O acesso participativo e universal do cidadao brasileiro ao conhecimento e um dos desafios colocados pela Sociedade Brasileira de Computaçao e este trabalho tende a colaborar neste sentido [29]. A pesquisa realizada com esta dissertacao caracteriza-se como um estudo exploratório, por haver u...

  4. Atmospheric Propagation Effects through Natural and Man-Made Obscurants for Visible to MM-Wave Radiation (Les Effets des Conditions Defavorables de Propagation sur les Systemes Optiques, IR et a Ondes Millimetiques)

    Science.gov (United States)

    1993-11-01

    satisfying certain data-quality Figure l(b) shows plots of p(Vwo) for a0 =- m2 and p(V.) for criteria were included in the data base. For each terrain cat ...RESUME 0naX0. - 2A Le Principe d’un syst~me pour Ia granulom ~trie par na.O) N R~ diffusion de lumi~re des particules d’un milieu tr~s faiblement...distribution en taille des airosols atxnosph6riques. G~n~ralement. Ia distribution en taille d’atdrosols par = ga)d mesures de diffusion "in-situ" cat

  5. PROAGRO - Programa de Garantia de Atividade Agropecuaria: avaliação de seus objetivos na microrregião homogenea de Passo-Fundo - RS

    OpenAIRE

    Formiga, Tadeu Nobre

    1983-01-01

    No Brasil nao e raro a criação de Programas pelas autoridades governamentais, para atender. determina da situação conjuntural ou para direcionar os esforços de pro . .' dução a uma atividade específica. Ocorre, porém, na maioria das vezes que não se criam -- simultaneamente ã formulação-instr~ mentos efetivos para sua avaliação e assim, os programas se agigantam e -introdu~em seus próprios mecanismos de de fesa para sua autopreservação. Este trabalho objetiva avalia...

  6. Promoción de la alimentación saludable en el aula de Infantil

    OpenAIRE

    Díez Cañibano, Raquel

    2017-01-01

    Ante la realidad con la que nos encontramos, que sitúa a España como uno de los países con el porcentaje más elevado de obesidad infantil, y siendo ésta debida a unos malos hábitos alimenticios y al sedentarismo, numerosas instituciones y organismos trabajan para cambiar esta realidad. Para acabar con esta situación, la Agencia Española de Seguridad Alimentaria y Nutrición pone en marcha la Estrategia NAOS y el Programa PERSEO a nivel nacional, con la misma finalidad que el Programa THAO, per...

  7. Climate change in Greenland, Denmark and the Levant

    DEFF Research Database (Denmark)

    Schrøder, Niels

    presented their isotopic records it was clear that the records were similar showing a series of climatic fluctuations (Dansgaard/Oescher events) We have re-examined the Yarbrud site in Syria (OSL dating and pollen analysis) in the hope that we could correlate the 25 cultural layers here (Rust 1950......), with the Dansgaard/Oescher events. It is concluded that: The effect of the NAO (North Atlantic Oscillation), given rise to opposite climate conditions in Denmark (NW Europe), the Levant and Greenland in the observation based climatic overview showis an interannual to decadal correlation of the climate...... Oscillation), archaeology, pollen, Blytt-Sernander model....

  8. Holocene climate aridification trend and human impact interrupted by millennial- and centennial-scale climate fluctuations from a new sedimentary record from Padul (Sierra Nevada, southern Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    M. J. Ramos-Román

    2018-01-01

    Full Text Available Holocene centennial-scale paleoenvironmental variability has been described in a multiproxy analysis (i.e., lithology, geochemistry, macrofossil, and microfossil analyses of a paleoecological record from the Padul Basin in Sierra Nevada, southern Iberian Peninsula. This sequence covers a relevant time interval hitherto unreported in the studies of the Padul sedimentary sequence. The  ∼  4700-year record has preserved proxies of climate variability, with vegetation, lake levels, and sedimentological change during the Holocene in one of the most unique and southernmost wetlands in Europe. The progressive middle and late Holocene trend toward arid conditions identified by numerous authors in the western Mediterranean region, mostly related to a decrease in summer insolation, is also documented in this record; here it is also superimposed by centennial-scale variability in humidity. In turn, this record shows centennial-scale climate oscillations in temperature that correlate with well-known climatic events during the late Holocene in the western Mediterranean region, synchronous with variability in solar and atmospheric dynamics. The multiproxy Padul record first shows a transition from a relatively humid middle Holocene in the western Mediterranean region to more aridity from  ∼  4700 to  ∼  2800 cal yr BP. A relatively warm and humid period occurred between  ∼  2600 and  ∼  1600 cal yr BP, coinciding with persistent negative North Atlantic Oscillation (NAO conditions and the historic Iberian–Roman Humid Period. Enhanced arid conditions, co-occurring with overall positive NAO conditions and increasing solar activity, are observed between  ∼  1550 and  ∼  450 cal yr BP (∼  400 to  ∼  1400 CE and colder and warmer conditions occurred during the Dark Ages and Medieval Climate Anomaly (MCA, respectively. Slightly wetter conditions took place during the end of

  9. The climate of the Common Era off the Iberian Peninsula

    Science.gov (United States)

    Abrantes, Fátima; Rodrigues, Teresa; Rufino, Marta; Salgueiro, Emília; Oliveira, Dulce; Gomes, Sandra; Oliveira, Paulo; Costa, Ana; Mil-Homens, Mário; Drago, Teresa; Naughton, Filipa

    2017-12-01

    The Mediterranean region is a climate hot spot, sensitive not only to global warming but also to water availability. In this work we document major temperature and precipitation changes in the Iberian Peninsula and margin during the last 2000 years and propose an interplay of the North Atlantic internal variability with the three atmospheric circulation modes (ACMs), (North Atlantic Oscillation (NAO), east atlantic (EA) and Scandinavia (SCAND)) to explain the detected climate variability. We present reconstructions of sea surface temperature (SST derived from alkenones) and on-land precipitation (estimated from higher plant n-alkanes and pollen data) in sedimentary sequences recovered along the Iberian Margin between the south of Portugal (Algarve) and the northwest of Spain (Galiza) (36 to 42° N). A clear long-term cooling trend, from 0 CE to the beginning of the 20th century, emerges in all SST records and is considered to be a reflection of the decrease in the Northern Hemisphere summer insolation that began after the Holocene optimum. Multi-decadal/centennial SST variability follows other records from Spain, Europe and the Northern Hemisphere. Warm SSTs throughout the first 1300 years encompass the Roman period (RP), the Dark Ages (DA) and the Medieval Climate Anomaly (MCA). A cooling initiated at 1300 CE leads to 4 centuries of colder SSTs contemporary with the Little Ice Age (LIA), while a climate warming at 1800 CE marks the beginning of the modern/Industrial Era. Novel results include two distinct phases in the MCA: an early period (900-1100 years) characterized by intense precipitation/flooding and warm winters but a cooler spring-fall season attributed to the interplay of internal oceanic variability with a positive phase in the three modes of atmospheric circulation (NAO, EA and SCAND). The late MCA is marked by cooler and relatively drier winters and a warmer spring-fall season consistent with a shift to a negative mode of the SCAND. The Industrial Era

  10. Chuanxiong preparations for preventing stroke.

    Science.gov (United States)

    Yang, Xunzhe; Zeng, Xiaoxi; Wu, Taixiang

    2010-01-20

    Stroke is a major healthcare problem and is one of the leading causes of death and serious long-term disability. Prevention of stroke is considered an important strategy. Chuanxiong is traditionally used in China in the treatment and prevention of stroke. In recent years, Chinese researchers have developed new patented Chuanxiong preparations. To assess the effects and safety of Chuanxiong preparations in preventing stroke in high-risk adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2008, Issue 1), MEDLINE (1950 to March 2008), EMBASE (1980 to March 2008), AMED (1985 to March 2008), Chinese Biomedical Database (CBM) (1975 to March 2008), China National Knowledge Infrastructure (CNKI) (1994 to March 2008), and the VIP Database (1989 to March 2008). Trials registers were searched for ongoing studies. No language restrictions were applied. Randomised controlled trials (RCTs) studying the effects of Chuanxiong preparations in preventing stroke were included. Three reviewers independently selected studies for inclusion and two reviewers independently extracted data. Authors of identified RCTs were telephoned to confirm the randomisation procedure. Outcomes assessed included: stroke, composite cardiovascular outcomes, changes in cardiovascular and cerebrovascular haemodynamic indices and adverse events. Peto odds ratio (OR) with 95% confidence intervals (CI) were calculated for dichotomous variables and mean differences for continuous outcomes. Three RCTs (5042 participants) were included. One higher quality study (4415 participants) compared Nao-an capsule with aspirin for primary prevention in high-risk stroke populations. Nao-an capsule appeared to reduce the incidence of stroke compared with aspirin (OR 0.56 95% CI 0.33 to 0.96). One study of low methodological quality indicated that a self-prepared Xifenwan tablet reduced the incidence of stroke in people with transient ischaemia attack (TIA) (OR 0.18, 95% CI 0.04 to 0.78). The

  11. Multi-scale dynamical analysis (MSDA) of sea level records versus PDO, AMO, and NAO indexes

    OpenAIRE

    Scafetta, Nicola

    2013-01-01

    Herein I propose a multi-scale dynamical analysis to facilitate the physical interpretation of tide gauge records. The technique uses graphical diagrams. It is applied to six secular-long tide gauge records representative of the world oceans: Sydney, Pacific coast of Australia; Fremantle, Indian Ocean coast of Australia; New York City, Atlantic coast of USA; Honolulu, U.S. state of Hawaii; San Diego, U.S. state of California; and Venice, Mediterranean Sea, Italy. For comparison, an equivalent...

  12. Asphaltenes analysis arising of non conventional oils; Analise de asfaltenos oriundos de petroleos nao convencionais

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Fernanda B. da; Fiorio, Paula G.P.; Guimaraes, Maria Jose O.C.; Seidl, Peter R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2012-07-01

    The need to use heavy fractions in an efficient way in the production of nobler fractions has motivated the search for ways of separating the asphaltenes, since these molecules increase the viscosity of the fractions submitted to distillation, contribute to the formation of coke and to poisoning and deactivation of catalysts used in process such as cracking, reform, etc, besides provoking cloggings and blockages caused by its deposition, generating losses on the productivity and increases of the operational costs. This paper evaluates the influence of solvent blends (EQ-NP) in the selective extraction of constituents of three samples from Brazilian heavy crude. For the extraction process was used two solvent blends (N1P1 and N1P2). The solvent blend composed of N1P1 showed a higher selectivity in the extraction of aggregates than N1P2. The extracted fraction was characterized by Hydrogen Nuclear Magnetic Resonance ({sup 1}H-NMR) and revealed that the chemical species extracted from different blends exhibit very small differences. (author)

  13. Word Embeddings para la anotación automática de gestos aplicada a Nao

    OpenAIRE

    Almagro Cádiz, Mario

    2017-01-01

    En los últimos años, la integración progresiva de la robótica de servicios en los hogares ha despertado el interés de la comunidad científica por las interacciones de tipo robot-humano. Estudios recientes han arrojado nuevas líneas de investigació

  14. Use of variability modes to evaluate AR4 climate models over the Euro-Atlantic region

    Energy Technology Data Exchange (ETDEWEB)

    Casado, M.J.; Pastor, M.A. [Agencia Estatal de Meteorologia (AEMET), Madrid (Spain)

    2012-01-15

    This paper analyzes the ability of the multi-model simulations from the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) to simulate the main leading modes of variability over the Euro-Atlantic region in winter: the North-Atlantic Oscillation (NAO), the Scandinavian mode (SCAND), the East/Atlantic Oscillation (EA) and the East Atlantic/Western Russia mode (EA/WR). These modes of variability have been evaluated both spatially, by analyzing the intensity and location of their anomaly centres, as well as temporally, by focusing on the probability density functions and e-folding time scales. The choice of variability modes as a tool for climate model assessment can be justified by the fact that modes of variability determine local climatic conditions and their likely change may have important implications for future climate changes. It is found that all the models considered are able to simulate reasonably well these four variability modes, the SCAND being the mode which is best spatially simulated. From a temporal point of view the NAO and SCAND modes are the best simulated. UKMO-HadGEM1 and CGCM3.1(T63) are the models best at reproducing spatial characteristics, whereas CCSM3 and CGCM3.1(T63) are the best ones with regard to the temporal features. GISS-AOM is the model showing the worst performance, in terms of both spatial and temporal features. These results may bring new insight into the selection and use of specific models to simulate Euro-Atlantic climate, with some models being clearly more successful in simulating patterns of temporal and spatial variability than others. (orig.)

  15. Impact of climate variability on various Rabi crops over Northwest India

    Science.gov (United States)

    Nageswararao, M. M.; Dhekale, B. S.; Mohanty, U. C.

    2018-01-01

    The Indian agriculture with its two prominent cropping seasons [summer ( Kharif) and winter ( Rabi)] is the mainstay of the rural economy. Northwest India (NWI) is an important region for the cultivation of Rabi crops grown during the period from October to April. In the present study, state wise impact analysis is carried out to ascertain the influence of climate indices Nino3.4 region Sea Surface Temperature (SST), Southern Oscillation Index (SOI), Arctic Oscillation (AO), North Atlantic Oscillation (NAO) and local precipitation, soil moisture, minimum ( T min), maximum ( T max) and mean ( T mean) temperatures on different Rabi crops (wheat, gram, rapeseed-mustard, oilseeds, and total Rabi food grains) over NWI during the years 1966-2011. To study the impact of climate variability on different Rabi crops, firstly, the influence of technology on the productivity of these crops has been removed by using linear function, as linear trend has noticed in all the time series. Correlation analysis provides an indication of the influence of local precipitation, soil moisture, T min, T max and T mean and some of its potential predictors (Nino3.4 region SST, SOI, AO, and NAO) on the productivity of different Rabi crops. Overall impact analysis indicates that the productivity of different Rabi crops in most of the places of NWI is most likely influenced by variability in local temperatures. Moreover, Nino3.4 region SST (SOI) positively (negatively) affects the productivity of gram, rapeseed-mustard, and total Rabi oilseeds in most of the states. The results of this study are useful in determining the strategies for increasing sustainable production through better agronomic practices.

  16. Atmospheric influence on Arctic marginal ice zone position and width in the Atlantic sector, February-April 1979-2010

    Energy Technology Data Exchange (ETDEWEB)

    Strong, Courtenay [University of Utah, Salt Lake City, UT (United States)

    2012-12-15

    Arctic marginal ice zone (MIZ) widths in the Atlantic sector were measured during the months of maximum sea ice extent (February-April) for years 1979-2010 using a novel method based on objective curves through idealized sea ice concentration fields that satisfied Laplace's equation. Over the record, the Labrador Sea MIZ (MIZ{sub L}) had an average width of 122 km and narrowed by 28 % while moving 254 km poleward, the Greenland Sea MIZ (MIZ{sub G}) had an average width of 98 km and narrowed by 43 % while moving 158 km west toward the Greenland coast, and the Barents Sea MIZ (MIZ{sub B}) had an average width of 136 km and moved 259 km east toward the Eurasian coast without a trend in width. Trends in MIZ position and width were consistent with a warming Arctic and decreasing sea ice concentrations over the record. Beyond the trends, NAO-like atmospheric patterns influenced interannual variability in MIZ position and width: MIZ{sub L} widened and moved southeast under anomalously strong northerly flow conducive to advection of sea ice into the Labrador Sea, MIZ{sub G} widened and moved northeast under anomalously weak northerly flow conducive to diminishing the westward component of sea ice drift, and MIZ{sub B} widened and moved poleward at the expense of pack ice under anomalously strong southwesterly flow conducive to enhancing oceanic heat flux into the Barents Sea. In addition, meridional flow anomalies associated with the NAO per se moved MIZ{sub B} east and west by modulating sea ice concentration over the Barents Sea. (orig.)

  17. Middle-to-late Holocene palaeoenvironmental reconstruction from the A294 ice-cave record (Central Pyrenees, northern Spain)

    Science.gov (United States)

    Sancho, Carlos; Belmonte, Ánchel; Bartolomé, Miguel; Moreno, Ana; Leunda, María; López-Martínez, Jerónimo

    2018-02-01

    Perennial ice deposits in caves represent unique, but underexplored, terrestrial sequences that potentially contain outstanding palaeoclimatic records. Here, we present a pioneer palaeoenvironmental study of an ice deposit preserved in a small sag-type cave (A294) in the Central Pyrenees (northern Iberian Peninsula). The 9.25-m-thick sequence, which is dated from 6100 ± 107 to 1888 ± 64 cal BP, represents the oldest known firn ice record worldwide. The stratigraphy (detrital layers, unconformities, and cross stratification), plant macrofossils, and isotopic signature (similarity between the ice linear distribution, δ2H = 7.83δ18O + 8.4, and the Global Meteoric Water Line) of the ice point to the diagenesis of snow introduced to the cave by winter snowstorms. Four phases of rapid ice accumulation (6100-5515, 4945-4250, 3810-3155, and 2450-1890 cal BP) are related to wetter and colder winters. Comparison of the isotopic composition (δ18O and deuterium excess) of the ice with other paleoclimate records show that both source effects and the North Atlantic Oscillation (NAO) mechanism exert a dominant influence on the ice cave record. The NAO signal may be a combination of source effects and rainfall amount. Three intervals with low ice accumulation occurred between the phases of rapid accumulation and were related to drier, and possibly warmer, winters. These centennial-scale episodes appear to be in-phase with regional arid events, as established from high altitude lacustrine records and can be correlated to global Rapid Climate Change events. The current warming trend has dramatically decreased the volume of the ice deposit in cave A294.

  18. Precipitation, temperature, and teleconnection signals across the combined North American, Monsoon Asia, and Old World Drought Atlases

    Science.gov (United States)

    Smerdon, J. E.; Baek, S. H.; Coats, S.; Williams, P.; Cook, B.; Cook, E. R.; Seager, R.

    2017-12-01

    The tree-ring-based North American Drought Atlas (NADA), Monsoon Asia Drought Atlas (MADA), and Old World Drought Atlas (OWDA) collectively yield a near-hemispheric gridded reconstruction of hydroclimate variability over the last millennium. To test the robustness of the large-scale representation of hydroclimate variability across the drought atlases, the joint expression of seasonal climate variability and teleconnections in the NADA, MADA, and OWDA are compared against two global, observation-based PDSI products. Predominantly positive (negative) correlations are determined between seasonal precipitation (surface air temperature) and collocated tree-ring-based PDSI, with average Pearson's correlation coefficients increasing in magnitude from boreal winter to summer. For precipitation, these correlations tend to be stronger in the boreal winter and summer when calculated for the observed PDSI record, while remaining similar for temperature. Notwithstanding these differences, the drought atlases robustly express teleconnection patterns associated with the El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO). These expressions exist in the drought atlas estimates of boreal summer PDSI despite the fact that these modes of climate variability are dominant in boreal winter, with the exception of the Atlantic Multidecadal Oscillation. ENSO and NAO teleconnection patterns in the drought atlases are particularly consistent with their well-known dominant expressions in boreal winter and over the OWDA domain, respectively. Collectively, our findings confirm that the joint Northern Hemisphere drought atlases robustly reflect large-scale patterns of hydroclimate variability on seasonal to multidecadal timescales over the 20th century and are likely to provide similarly robust estimates of hydroclimate variability prior to the existence of widespread instrumental data.

  19. Long-term hydroclimatic variability in monsoon shadow zone of western Himalaya, India

    Science.gov (United States)

    Yadav, Ram R.

    2011-04-01

    Tree-ring-width data of Himalayan cedar [ Cedrus deodara (Roxb.) G. Don] from 11 homogeneous moisture stressed sites in the monsoon shadow zone of the western Himalaya were used to develop a mean chronology extending back to ad 1353. The chronology developed using Regional Curve Standardization method is the first from the Himalayan region of India showing centennial-scale variations. The calibration of ring-width chronology with instrumental precipitation data available from stations close to the tree ring sampling sites showed strong, direct relationship with March-April-May-June (MAMJ) precipitation. This strong relationship was used to supplement the instrumental precipitation data back to ad 1410. The precipitation reconstruction showed extended period of drought in fifteenth and sixteenth centuries. Increasingly pluvial conditions were recorded since eighteenth century, with the highest precipitation in the early part of the nineteenth century. The decreasing trend in reconstructed precipitation in the last decade of the twentieth century, consistent with the instrumental records, is associated with the decreasing trend in frequency of western disturbances. MAMJ precipitation over the monsoon shadow zone in the western Himalaya is directly associated with the North Atlantic Oscillation (NAO) and NINO3-SST index of El Nino-Southern Oscillation (ENSO), the leading modes of climate variability influencing climate over large parts of the Northern Hemisphere. However, the relationship between ENSO and MAMJ precipitation collapsed completely during 1930-1960. The breakdown in this relationship is associated with the warm phase of Atlantic Multidecadal Oscillation (AMO). A spectral analysis of reconstructed MAMJ precipitation indicates frequencies in the range of the variability associated with modes of NAO, ENSO and AMO.

  20. Non-stationary analysis of the frequency and intensity of heavy precipitation over Canada and their relations to large-scale climate patterns

    Science.gov (United States)

    Tan, Xuezhi; Gan, Thian Yew

    2017-05-01

    In recent years, because the frequency and severity of floods have increased across Canada, it is important to understand the characteristics of Canadian heavy precipitation. Long-term precipitation data of 463 gauging stations of Canada were analyzed using non-stationary generalized extreme value distribution (GEV), Poisson distribution and generalized Pareto (GP) distribution. Time-varying covariates that represent large-scale climate patterns such as El Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Pacific decadal oscillation (PDO) and North Pacific Oscillation (NP) were incorporated to parameters of GEV, Poisson and GP distributions. Results show that GEV distributions tend to under-estimate annual maximum daily precipitation (AMP) of western and eastern coastal regions of Canada, compared to GP distributions. Poisson regressions show that temporal clusters of heavy precipitation events in Canada are related to large-scale climate patterns. By modeling AMP time series with non-stationary GEV and heavy precipitation with non-stationary GP distributions, it is evident that AMP and heavy precipitation of Canada show strong non-stationarities (abrupt and slowly varying changes) likely because of the influence of large-scale climate patterns. AMP in southwestern coastal regions, southern Canadian Prairies and the Great Lakes tend to be higher in El Niño than in La Niña years, while AMP of other regions of Canada tends to be lower in El Niño than in La Niña years. The influence of ENSO on heavy precipitation was spatially consistent but stronger than on AMP. The effect of PDO, NAO and NP on extreme precipitation is also statistically significant at some stations across Canada.

  1. Abundance patterns of evolved stars with Hipparcos parallaxes and ages based on the APOGEE data base

    Science.gov (United States)

    Jia, Y. P.; Chen, Y. Q.; Zhao, G.; Bari, M. A.; Zhao, J. K.; Tan, K. F.

    2018-01-01

    We investigate the abundance patterns for four groups of stars at evolutionary phases from sub-giant to red clump (RC) and trace the chemical evolution of the disc by taking 21 individual elemental abundances from APOGEE and ages from evolutionary models with the aid of Hipparcos distances. We find that the abundances of six elements (Si, S, K, Ca, Mn and Ni) are similar from the sub-giant phase to the RC phase. In particular, we find that a group of stars with low [C/N] ratios, mainly from the second sequence of RC stars, show that there is a difference in the transfer efficiency of the C-N-O cycle between the main and the secondary RC sequences. We also compare the abundance patterns of C-N, Mg-Al and Na-O with giant stars in globular clusters from APOGEE and find that field stars follow similar patterns as M107, a metal-rich globular cluster with [M/H] ∼- 1.0, which shows that the self-enrichment mechanism represented by strong C-N, Mg-Al and Na-O anti-correlations may not be important as the metallicity reaches [M/H] > -1.0 dex. Based on the abundances of above-mentioned six elements and [Fe/H], we investigate age versus abundance relations and find some old super-metal-rich stars in our sample. Their properties of old age and being rich in metal are evidence for stellar migration. The age versus metallicity relations in low-[α/M] bins show unexpectedly positive slopes. We propose that the fresh metal-poor gas infalling on to the Galactic disc may be the precursor for this unexpected finding.

  2. PALLETS, A LIFE CYCLE ANALYSIS: A STUDY TO DEMONSTRATE THE IMPORTANCE OF DESIGN TO SUSTAINABILITY

    Directory of Open Access Journals (Sweden)

    Rita de Castro Engler

    2017-11-01

    Full Text Available Este artigo tem como objetivo demonstrar a importância do design transdisciplinar voltado para sustentabilidade, relacionando diferentes campos do saber com relevantes questoes e problemas complexos (wicked problems – consumo e produçao, sustentabilidade, gestao de pessoas e processos, tecnologia, excesso de informaçoes, relaçao homem e objeto, cultura, identidade, entre outros – que permeiam o atual cenário fluido e em constante mutaçao. A resoluçao de problemas complexos e perversos nao deve ser entendida como responsabilidade somente dos atores políticos, novas redes devem ser criadas entre indivíduos, empresas e o poder público, associando a criatividade e o empreendedorismo para geraçao de valores compartilhados e soluçoes potenciais em prol da sustentabilidade. A gestao compartilhada de problemas vai ser discutida através de uma metodologia descritiva de estudo de caso em duas comunidades diferentes, mas com propósitos semelhantes. As comunidades do município de Jeceaba (MG e bairro Jardim Canadá (Nova Lima, MG, que reaproveitaram resíduos (paletes descartados para produçao de mobiliários e adornos, com o intuito de minimizar os impactos ambientais, porém uma aplica a metodologia do design no processo criativo e na execuçao das peças enquanto a outra nao adota a metodologia em respeito as limitaçoes locais. A análise desses estudos leva a compreensao da importância do design que produz projetos economicamente eficientes, socialmente justos e ambientalmente sustentáveis.

  3. Spatio-temporal long-term (1950-2009) temperature trend analysis in North Carolina, United States

    Science.gov (United States)

    Sayemuzzaman, Mohammad; Jha, Manoj K.; Mekonnen, Ademe

    2015-04-01

    This study analyzed long-term (1950-2009) annual and seasonal time series data of maximum and minimum temperature from 249 uniformly distributed stations across the State of North Carolina, United States. The Mann-Kendall and Theil-Sen approach were applied to quantify the significance and magnitude of trend, respectively. A pre-whitening technique was applied to eliminate the effect of lag-1 serial correlation. For most stations over the period of the past 60 years, the difference between minimum and maximum temperatures was found decreasing with an overall increasing trend in the mean temperature. However, significant trends (confidence level ≥ 95 %) in the mean temperature analysis were detected only in 20, 3, 23, and 20 % of the stations in summer, winter, autumn, and spring, respectively. The magnitude of the highest warming trend in minimum temperature and the highest cooling trend in maximum temperature was +0.073 °C/year in the autumn season and -0.12 °C/year in the summer season, respectively. Additional analysis in mean temperature trend was conducted on three regions of North Carolina (mountain, piedmont, and coastal). The results revealed a warming trend for the coastal zone, a cooling trend for the mountain zone, and no distinct trend for the piedmont zone. The Sequential Mann-Kendall test results indicated that the significant increasing trends in minimum temperature and decreasing trend in maximum temperature had begun around 1970 and 1960 (change point), respectively, in most of the stations. Finally, the comparison between mean surface air temperature (SAT) and the North Atlantic Oscillation (NAO) concluded that the variability and trend in SAT can be explained partially by the NAO index for North Carolina.

  4. The Characteristics of Cold Air Outbreaks in the Eastern United States and the Influence of Atmospheric Circulation Patterns

    Science.gov (United States)

    Smith, E. T.

    2017-12-01

    Periods of extreme cold impact the mid-latitudes every winter. Depending on the magnitude and duration of the occurrence, extremely cold periods may be deemed cold air outbreaks (CAOs). Atmospheric teleconnections impact the displacement of polar air, but the relationship between the primary teleconnections and the manifestation of CAOs is not fully understood. A systematic CAO index was developed from 20 surface weather stations based on a set of criteria concerning magnitude, duration, and spatial extent. Statistical analyses of the data were used to determine the overall trends in CAOs. Clusters of sea level pressure (SLP), 100mb, and 10mb geopotential height anomalies were mapped utilizing self-organizing maps (SOMs) to understand the surface, upper-tropospheric Polar Vortex (PV), and stratospheric PV patterns preceding CAOs. The Arctic Oscillation (AO), North Atlantic Oscillation (NAO), and Pacific-North American (PNA) teleconnections were used as variables to explain the magnitude and location of mid-latitude Arctic air displacement. Persistently negative SLP anomalies across the Arctic and North Atlantic were evident 1 - 2 weeks prior to the CAOs throughout the winter. The upper-tropospheric and stratospheric PV were found to be persistently weak/weakening prior to mid-winter CAOs and predominantly strong and off-centered prior to early and late season CAOs. Negative phases of the AO and NAO were favored prior to CAOs, while the PNA favored a near-neutral phase. This method of CAO and synoptic pattern characterization benefits from a continuous pattern representation and provides insight as to how specific teleconnections impact the atmospheric flow in a way that leads to CAOs in the eastern U.S.

  5. Different Stratospheric Polar Vortex States linked to Cold-Spells in North America and Northern Eurasia

    Science.gov (United States)

    Kretschmer, M.; Cohen, J. L.; Runge, J.; Coumou, D.

    2017-12-01

    The stratospheric polar vortex in boreal winter can influence the tropospheric circulation and thereby surface weather in the mid-latitudes. Weak states of the vortex, e.g. associated with Sudden Stratospheric Warmings (SSWs), often precede a negative phase of the North Atlantic Oscillation (NAO), and thus increase the risk of mid-latitude cold-spells especially over Eurasia. Here we show using cluster analysis that next to the well-documented relationship between a zonally symmetric disturbed vortex and a negative NAO, there exists a zonally asymmetric pattern linked to a negative Western Pacific Oscillation (WPO) and cold-spells in the northeastern US, like for example observed in February 2014. The latter is more synoptic in time-scale but occurs more frequently than SSWs. A causal effect network (CEN) approach gives insights into the underlying physical pathways and time-lags showing that high-pressure around Greenland leads to vertical wave activity over eastern Siberia leading to downward propagating waves over Alaska and high pressure over the North Pacific. Moreover, composites propose that a rather strong mid-stratospheric vortex seems to be favorable for this zonally asymmetric and reflective mechanism. Overall, the mutual relationship between stratospheric circulation and high-latitude blocking in both the Pacific and Atlantic Oceans is complex and involves mechanisms operating at different time-scales. Our results suggest that the stratospheric influence on winter circulation should not exclusively be analyzed in terms of a downward propagating Northern Annular Mode (NAM) signal and SSWs. In particular when studying the stratospheric impacts on North American temperature it is crucial to also consider the more transient and zonally asymmetric events which might help to improve seasonal winter predictions for this region.

  6. Interannual variations and future change of wintertime extratropical cyclone activity over North America in CCSM3

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Haiyan; Washington, Warren M.; Meehl, Gerald A. [National Center for Atmospheric Research, PO Box 3000, Boulder, CO (United States)

    2008-06-15

    Climatology and interannual variations of wintertime extratropical cyclone frequency in CCSM3 twentieth century simulation are compared with the NCEP/NCAR reanalysis during 1950-1999. CCSM3 can simulate the storm tracks reasonably well, although the model produces slightly less cyclones at the beginning of the Pacific and Atlantic storm tracks and weaker poleward deflection over the Pacific. As in the reanalysis, frequency of cyclones stronger than 980 hPa shows significant correlation with the Pacific/North America (PNA) teleconnection pattern over the Pacific region and with the North Atlantic Oscillation (NAO) in the Atlantic sector. Composite maps are constructed for opposite phases of El Nino-Southern Oscillation (ENSO) and the NAO and all anomalous patterns coincide with observed. One CCSM3 twenty-first century A1B scenario realization indicates there is significant increase in the extratropical cyclone frequency on the US west coast and decrease in Alaska. Meanwhile, cyclone frequency increases from the Great Lakes region to Quebec and decreases over the US east coast, suggesting a possible northward shift of the Atlantic storm tracks under the warmer climate. The cyclone frequency anomalies are closely linked to changes in seasonal mean states of the upper-troposphere zonal wind and baroclinicity in the lower troposphere. Due to lack of 6-hourly outputs, we cannot apply the cyclone-tracking algorithm to the other eight CCSM3 realizations. Based on the linkage between the mean state change and the cyclone frequency anomalies, it is likely a common feature among the other ensemble members that cyclone activity is reduced on the East Coast and in Alaska as a result of global warming. (orig.)

  7. Twentieth century North Atlantic climate change. Part II: Understanding the effect of Indian Ocean warming

    Energy Technology Data Exchange (ETDEWEB)

    Hoerling, M.P.; Xu, T.; Bates, G.T. [Climate Diagnostics Center NOAA, Boulder, CO 80305-3328 (United States); Hurrell, J.W.; Phillips, A.S. [National Center for Atmospheric Research, Boulder, CO (United States)

    2004-09-01

    Ensembles of atmospheric general circulation model (AGCM) experiments are used in an effort to understand the boreal winter Northern Hemisphere (NH) extratropical climate response to the observed warming of tropical sea surface temperatures (SSTs) over the last half of the twentieth Century. Specifically, we inquire about the origins of unusual, if not unprecedented, changes in the wintertime North Atlantic and European climate that are well described by a linear trend in most indices of the North Atlantic Oscillation (NAO). The simulated NH atmospheric response to the linear trend component of tropic-wide SST change since 1950 projects strongly onto the positive polarity of the NAO and is a hemispheric pattern distinguished by decreased (increased) Arctic (middle latitude) sea level pressure. Progressive warming of the Indian Ocean is the principal contributor to this wintertime extratropical response, as shown through additional AGCM ensembles forced with only the SST trend in that sector. The Indian Ocean influence is further established through the reproducibility of results across three different models forced with identical, idealized patterns of the observed warming. Examination of the transient atmospheric adjustment to a sudden ''switch-on'' of an Indian Ocean SST anomaly reveals that the North Atlantic response is not consistent with linear theory and most likely involves synoptic eddy feedbacks associated with changes in the North Atlantic storm track. The tropical SST control exerted over twentieth century regional climate underlies the importance of determining the future course of tropical SST for regional climate change and its uncertainty. Better understanding of the extratropical responses to different, plausible trajectories of the tropical oceans is key to such efforts. (orig.)

  8. Crystal structure of polyphosphates NaCd(PO3)3 and NaMn(PO3)3

    International Nuclear Information System (INIS)

    Murashova, E.V.; Chudinova, N.N.

    1997-01-01

    Crystal structure of NaCd(PO 3 ) 3 (1) and NaMn(PO 3 ) 3 (2) isostructural polyphosphates was determined for twin samples. Rhombic lattice parameters of (1): a = 14.678, b = 14.669, c = 14.705 A, sp. gr. P2 1 2 1 2 1 , Z = 16. The structure of compounds is of frame type. Polyphosphate chain with repetition period of 24 PO 4 tetrahedrons contacts with NaO 6 and M 2 O 6 octahedrons by means of common oxygen vertices. Similarities and differences in structure of mentioned polyphosphates and earlier analyzed NaMg(PO 3 ) 3 polyphosphate are noted [ru

  9. The climate of the Common Era off the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    F. Abrantes

    2017-12-01

    Full Text Available The Mediterranean region is a climate hot spot, sensitive not only to global warming but also to water availability. In this work we document major temperature and precipitation changes in the Iberian Peninsula and margin during the last 2000 years and propose an interplay of the North Atlantic internal variability with the three atmospheric circulation modes (ACMs, (North Atlantic Oscillation (NAO, east atlantic (EA and Scandinavia (SCAND to explain the detected climate variability. We present reconstructions of sea surface temperature (SST derived from alkenones and on-land precipitation (estimated from higher plant n-alkanes and pollen data in sedimentary sequences recovered along the Iberian Margin between the south of Portugal (Algarve and the northwest of Spain (Galiza (36 to 42° N. A clear long-term cooling trend, from 0 CE to the beginning of the 20th century, emerges in all SST records and is considered to be a reflection of the decrease in the Northern Hemisphere summer insolation that began after the Holocene optimum. Multi-decadal/centennial SST variability follows other records from Spain, Europe and the Northern Hemisphere. Warm SSTs throughout the first 1300 years encompass the Roman period (RP, the Dark Ages (DA and the Medieval Climate Anomaly (MCA. A cooling initiated at 1300 CE leads to 4 centuries of colder SSTs contemporary with the Little Ice Age (LIA, while a climate warming at 1800 CE marks the beginning of the modern/Industrial Era. Novel results include two distinct phases in the MCA: an early period (900–1100 years characterized by intense precipitation/flooding and warm winters but a cooler spring–fall season attributed to the interplay of internal oceanic variability with a positive phase in the three modes of atmospheric circulation (NAO, EA and SCAND. The late MCA is marked by cooler and relatively drier winters and a warmer spring–fall season consistent with a shift to a negative mode of the

  10. Mechanical behaviour of AlSiC nano composites produced by ball milling and spark plasma sintering =

    Science.gov (United States)

    Buchheim, Claudia Sofia de Andrade Redondo Murilhas

    Neste trabalho foram produzidos nanocompositos de AlSiC misturando aluminio puro com nano particulas de SiC com diâmetro de 45 - 55 nm, usando, de forma sequencial, a tecnica da metalurgia do po e a compactacao por "Spark Plasma Sintering". O composito obtido apresentava graos com 100 nm de diâmetro, encontrandose as particulas de SiC localizadas, principalmente, nas fronteiras de grao. O nanocomposito sob a forma de provetes cilindricos foi submetido a testes de compressao uniaxial e a testes de nanoindentacao para analisar a influencia das nanoparticulas de SiC, da fracao volumica de acido estearico e do tempo de moagem, nas propriedades mecânicas do material. Para efeitos de comparacao, utilizouse o comportamento mecânico do Al puro processado em condicoes similares e da liga de aluminio AA1050O. A tensao limite de elasticidade do nanocomposito com 1% Vol./Vol. de SiC e dez vezes superior a do AA1050. O refinamento de grao a escala nano constitui o principal mecanismo de aumento de resistencia mecânica. Na realidade, o Al nanocristalino sem reforco de particulas de SiC, apresenta uma tensao limite de elasticidade sete vezes superior a da liga AA1050O. A adicao de 0,5 % Vol./Vol. e de 1 % Vol./Vol. de SiC conduzem, respetivamente, ao aumento da tensao limite de elasticidade em 47 % e 50%. O aumento do tempo de moagem e a adicao de acido estearico ao po durante a moagem conduzem apenas a um pequeno aumento da tensao de escoamento. A dureza do material medida atraves de testes de nanoindentacao confirmaram os dados anteriores. A estabilidade das microestruturas do aluminio puro e do nanocomposito AlSiC, foi testada atraves de recozimento de restauracao realizado as temperaturas de 150 °C e 250 °C durante 2 horas. Aparentemente, o tratamento termico nao influenciou as propriedades mecânicas dos materiais, excepto do nanocomposito com 1 % Vol./Vol. de SiC restaurado a temperatura de 250 °C, para o qual se observou uma reducao da tensao limite de elasticidade

  11. The Response of African Land Surface Phenology to Large Scale Climate Oscillations

    Science.gov (United States)

    Brown, Molly E.; de Beurs, Kirsten; Vrieling, Anton

    2010-01-01

    Variations in agricultural production due to rainfall and temperature fluctuations are a primary cause of food insecurity on the African continent. Analysis of changes in phenology can provide quantitative information on the effect of climate variability on growing seasons in agricultural regions. Using a robust statistical methodology, we describe the relationship between phenology metrics derived from the 26 year AVHRR NDVI record and the North Atlantic Oscillation index (NAO), the Indian Ocean Dipole (IOD), the Pacific Decadal Oscillation (PDO), and the Multivariate ENSO Index (MEI). We map the most significant positive and negative correlation for the four climate indices in Eastern, Western and Southern Africa between two phenological metrics and the climate indices. Our objective is to provide evidence of whether climate variability captured in the four indices has had a significant impact on the vegetative productivity of Africa during the past quarter century. We found that the start of season and cumulative NDVI were significantly affected by large scale variations in climate. The particular climate index and the timing showing highest correlation depended heavily on the region examined. In Western Africa the cumulative NDVI correlates with PDO in September-November. In Eastern Africa the start of the June-October season strongly correlates with PDO in March-May, while the PDO in December-February correlates with the start of the February-June season. The cumulative NDVI over this last season relates to the MEI of March-May. For Southern Africa, high correlations exist between SOS and NAO of September-November, and cumulative NDVI and MEI of March-May. The research shows that climate indices can be used to anticipate late start and variable vigor in the growing season of sensitive agricultural regions in Africa.

  12. Dynapenic obesity as an associated factor to lipid and glucose metabolism disorders and metabolic syndrome in older adults - Findings from SABE Study.

    Science.gov (United States)

    Alexandre, Tiago da Silva; Aubertin-Leheudre, Mylène; Carvalho, Lívia Pinheiro; Máximo, Roberta de Oliveira; Corona, Ligiana Pires; Brito, Tábatta Renata Pereira de; Nunes, Daniella Pires; Santos, Jair Licio Ferreira; Duarte, Yeda Aparecida de Oliveira; Lebrão, Maria Lúcia

    2018-08-01

    There is little evidence showing that dynapenic obesity is associated with lipid and glucose metabolism disorders, high blood pressure, chronic disease and metabolic syndrome. Our aim was to analyze whether dynapenic abdominal obesity can be associated with lipid and glucose metabolism disorders, high blood pressure, metabolic syndrome and cardiovascular diseases in older adults living in São Paulo. This cross-sectional study included 833 older adults who took part of the third wave of the Health, Well-being and Aging Study in 2010. Based on waist circumference (>88 cm women and >102 cm men) and handgrip strength (metabolic syndrome and cardiovascular diseases. Logistic regression was used to analyze the associations between dynapenia and abdominal obesity status and lipid and glucose metabolic profiles, blood pressure, cardiovascular diseases and metabolic syndrome. The fully adjusted models showed that D/AO individuals had higher prevalence of low HDL plasma concentrations (OR = 2.51, 95%CI: 1.40-4.48), hypertriglyceridemia (OR = 2.53, 95%CI: 1.43-4.47), hyperglycemia (OR = 2.05, 95%CI: 1.14-3.69), high glycated-haemoglobin concentrations (OR = 1.84, 95%CI: 1.03-3.30) and metabolic syndrome (OR = 12.39, 95%CI: 7.38-20.79) than ND/NAO. Dynapenic and D/AO individuals had higher prevalence of heart disease (OR = 2.05, 95%CI: 1.17-3.59 and OR = 1.92, 95%CI: 1.06-3.48, respectively) than ND/NAO. D/AO was associated with high prevalence of lipid and glucose metabolism disorders and metabolic syndrome while dynapenia and D/AO were associated with high prevalence of heart disease. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  13. Influence of long-range atmospheric transport pathways and climate teleconnection patterns on the variability of surface 210Pb and 7Be concentrations in southwestern Europe.

    Science.gov (United States)

    Grossi, C; Ballester, J; Serrano, I; Galmarini, S; Camacho, A; Curcoll, R; Morguí, J A; Rodò, X; Duch, M A

    2016-12-01

    The variability of the atmospheric concentration of the 7 Be and 210 Pb radionuclides is strongly linked to the origin of air masses, the strength of their sources and the processes of wet and dry deposition. It has been shown how these processes and their variability are strongly affected by climate change. Thus, a deeper knowledge of the relationship between the atmospheric radionuclides variability measured close to the ground and these atmospheric processes could help in the analysis of climate scenarios. In the present study, we analyze the atmospheric variability of a 14-year time series of 7 Be and 210 Pb in a Mediterranean coastal city using a synergy of different indicators and tools such as: the local meteorological conditions, global and regional climate indexes and a lagrangian atmospheric transport model. We particularly focus on the relationships between the main pathways of air masses and sun spots occurrence, the variability of the local relative humidity and temperature conditions, and the main modes of regional climate variability, such as the North Atlantic Oscillation (NAO) and the Western Mediterranean Oscillation (WeMO). The variability of the observed atmospheric concentrations of both 7 Be and 210 Pb radionuclides was found to be mainly positively associated to the local climate conditions of temperature and to the pathways of air masses arriving at the station. Measured radionuclide concentrations significantly increase when air masses travel at low tropospheric levels from central Europe and the western part of the Iberian Peninsula, while low concentrations are associated with westerly air masses. We found a significant negative correlation between the WeMO index and the atmospheric variability of both radionuclides and no significant association was observed for the NAO index. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Influence of climate cycles on grapevine domestication and ancient migrations in Eurasia.

    Science.gov (United States)

    Mariani, Luigi; Cola, Gabriele; Maghradze, David; Failla, Osvaldo; Zavatti, Franco

    2018-09-01

    The objective of this work is to investigate the Holocenic climate cycles that may have influenced the domestication of grapevine in the Subcaucasian area and its subsequent spread in Eurasia. The analysis covered the longitudinal belt ranging from the Iberian Peninsula to Japan, seen as the preferential pathway for the Holocenic spread of grapevine and many other crops in Eurasia. Spectral analysis was considered as the criterion of investigation and the Holocenic cycles were analyzed considering different geochemical and biological proxies, of which seven are directly referred to vine. In this context the relation of the abovementioned proxies with spectral peaks of possible causal factors like Solar activity (SA), North Atlantic oceanic factors (Atlantic Multidecadal Oscillation - AMO and North Atlantic Oscillation - NAO), and subtropical oceanic factors (El Nino Southern Oscillation - ENSO) was also analyzed. In order to acquire a sufficiently wide number of proxies sensitive to the causal factors, we referred to a latitudinal belt wider than the one colonized by vine, also acquiring proxy from the Scandinavian area, notoriously susceptible to North Atlantic forcings. The analysis of the proxy spectral peaks, considering 20 classes with a 50-years step in the 0-1000 years range, showed that the 50% of the classes have a higher frequency of peaks at East than West, the 20% a higher frequency at West than East and the 10% an equal frequency, showing the efficiency of the propagation of Western signals towards the center of Eurasia. The search of the causal factors spectral peaks in the proxy series showed that AMO, NAO and SA acted with a certain regularity on the entire belt investigated both latitudinally and longitudinally, while spectral peaks linked to ENSO underwent a considerable attenuation moving northward. Finally, the specific analysis on viticultural proxies showed common peaks with causal factors. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Time-scale and extent at which large-scale circulation modes determine the wind and solar potential in the Iberian Peninsula

    International Nuclear Information System (INIS)

    Jerez, Sonia; Trigo, Ricardo M

    2013-01-01

    The North Atlantic Oscillation (NAO), the East Atlantic (EA) and the Scandinavian (SCAND) modes are the three main large-scale circulation patterns driving the climate variability of the Iberian Peninsula. This study assesses their influence in terms of solar (photovoltaic) and wind power generation potential (SP and WP) and evaluates their skill as predictors. For that we use a hindcast regional climate simulation to retrieve the primary meteorological variables involved, surface solar radiation and wind speed. First we identify that the maximum influence of the various modes occurs on the interannual variations of the monthly mean SP and WP series, being generally more relevant in winter. Second we find that in this time-scale and season, SP (WP) varies up to 30% (40%) with respect to the mean climatology between years with opposite phases of the modes, although the strength and the spatial distribution of the signals differ from one month to another. Last, the skill of a multi-linear regression model (MLRM), built using the NAO, EA and SCAND indices, to reconstruct the original wintertime monthly series of SP and WP was investigated. The reconstructed series (when the MLRM is calibrated for each month individually) correlate with the original ones up to 0.8 at the interannual time-scale. Besides, when the modeled series for each individual month are merged to construct an October-to-March monthly series, and after removing the annual cycle in order to account for monthly anomalies, these correlate 0.65 (0.55) with the original SP (WP) series in average. These values remain fairly stable when the calibration and reconstruction periods differ, thus supporting up to a point the predictive potential of the method at the time-scale assessed here. (letter)

  16. The record precipitation and flood event in Iberia in December 1876: description and synoptic analysis

    Directory of Open Access Journals (Sweden)

    Ricardo Machado Trigo

    2014-04-01

    Full Text Available The first week of December 1876 was marked by extreme weather conditions that affected the south-western sector of the Iberian Peninsula, leading to an all-time record flow in two large international rivers. As a direct consequence, several Portuguese and Spanish towns and villages located in the banks of both rivers suffered serious flood damage on 7 December 1876. These unusual floods were amplified by the preceding particularly autumn wet months, with October 1876 presenting extremely high precipitation anomalies for all western Iberia stations. Two recently digitised stations in Portugal (Lisbon and Evora, present a peak value on 5 December 1876. Furthermore, the values of precipitation registered between 28 November and 7 December were so remarkable that, the episode of 1876 still corresponds to the maximum average daily precipitation values for temporal scales between 2 and 10 days. Using several different data sources, such as historical newspapers of that time, meteorological data recently digitised from several stations in Portugal and Spain and the recently available 20th Century Reanalysis, we provide a detailed analysis on the socio-economic impacts, precipitation values and the atmospheric circulation conditions associated with this event. The atmospheric circulation during these months was assessed at the monthly, daily and sub-daily scales. All months considered present an intense negative NAO index value, with November 1876 corresponding to the lowest NAO value on record since 1865. We have also computed a multivariable analysis of surface and upper air fields in order to provide some enlightening into the evolution of the synoptic conditions in the week prior to the floods. These events resulted from the continuous pouring of precipitation registered between 28 November and 7 December, due to the consecutive passage of Atlantic low-pressure systems fuelled by the presence of an atmospheric-river tropical moisture flow over

  17. Variability of the Atlantic meridional overturning circulation in the last millennium and two IPCC scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, Pablo; Montoya, Marisa; Gonzalez-Rouco, Fidel [Universidad Complutense de Madrid, Ciudad Universitaria, Dpto. Astrofisica y Ciencias de la Atmosfera/Instituto de Geociencias, Facultad de Ciencias Fisicas, Madrid (Spain); Universidad Complutense de Madrid, Ciudad Universitaria, Instituto de Geociencias (UCM-CSIC), Facultad de Ciencias Fisicas, Madrid (Spain); Mignot, Juliette [IPSL/LOCEAN, UPMC/CNRS/IRD/MNHN, Universite Pierre et Marie Curie, Paris Cedex 05 (France); Legutke, Stephanie [Deutsches Klimarechenzentrum (DKRZ), Hamburg (Germany)

    2012-05-15

    The variability of the Atlantic meridional overturning circulation (AMOC) is investigated in several climate simulations with the ECHO-G atmosphere-ocean general circulation model, including two forced integrations of the last millennium, one millennial-long control run, and two future scenario simulations of the twenty-first century. This constitutes a new framework in which the AMOC response to future climate change conditions is addressed in the context of both its past evolution and its natural variability. The main mechanisms responsible for the AMOC variability at interannual and multidecadal time scales are described. At high frequencies, the AMOC is directly responding to local changes in the Ekman transport, associated with three modes of climate variability: El Nino-Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and the East Atlantic (EA) pattern. At low frequencies, the AMOC is largely controlled by convection activity south of Greenland. Again, the atmosphere is found to play a leading role in these variations. Positive anomalies of convection are preceded in 1 year by intensified zonal winds, associated in the forced runs to a positive NAO-like pattern. Finally, the sensitivity of the AMOC to three different forcing factors is investigated. The major impact is associated with increasing greenhouse gases, given their strong and persistent radiative forcing. Starting in the Industrial Era and continuing in the future scenarios, the AMOC experiences a final decrease of up to 40% with respect to the preindustrial average. Also, a weak but significant AMOC strengthening is found in response to the major volcanic eruptions, which produce colder and saltier surface conditions over the main convection regions. In contrast, no meaningful impact of the solar forcing on the AMOC is observed. Indeed, solar irradiance only affects convection in the Nordic Seas, with a marginal contribution to the AMOC variability in the ECHO-G runs. (orig.)

  18. Assessment of a new biological complex efficacy on dysseborrhea, inflammation, and Propionibacterium acnes proliferation

    Directory of Open Access Journals (Sweden)

    Trompezinski S

    2016-08-01

    Full Text Available Sandra Trompezinski,1 Sophie Weber,1 Benoît Cadars,2 Florence Larue,1 Nathalie Ardiet,1 Marlène Chavagnac-Bonneville,2 Michèle Sayag,2 Eric Jourdan2 1NAOS, Aix-en Provence, 2Direction Scientifique Bioderma (NAOS, Lyon, France Introduction: Acne vulgaris is a common chronic inflammatory disease of the pilosebaceous unit triggered by Propionibacterium acnes. A bakuchiol, Ginkgo biloba extract, and mannitol (BGM complex has been developed to provide patients with acne with a specific dermocosmetic to be used adjunctively with conventional treatments. Objective: The aim of these studies was to assess the antibacterial, anti-inflammatory, and antioxidative potential of BGM complex and its individual compounds as well as its impact on sebum composition. Methods: The antibacterial, anti-inflammatory, and antioxidative potential of BGM complex and its compounds was assessed through in vitro, ex vivo, and clinical studies. The clinical benefit of BGM complex formulated in a cream was assessed in subjects prone to acne through sebum composition analysis and photometric assessments. Results: Results from the studies showed that the BGM complex has significant antibacterial, anti-inflammatory, and antioxidative properties. At similar concentrations, bakuchiol has up to twice the antioxidative potential than vitamin E. In subjects, BGM complex regulated the sebum composition in acne patients by increasing the level of sapienic and linolenic acid and reducing the level of oleic acid. The reduced number of porphyrins on the skin surface showed that it is also effective against P. acnes. Conclusion: BGM complex provides a complete adjunctive care in patients with acne by targeting etiopathogenic factors of acne: dysseborrhea, inflammation, and P. acnes proliferation. Keywords: acne, antibacterial, anti-inflammatory, antioxidation, cosmetics, sebum

  19. Does climate change explain the decline of a trans-Saharan Afro-Palaearctic migrant?

    Science.gov (United States)

    Pearce-Higgins, J W; Yalden, D W; Dougall, T W; Beale, C M

    2009-03-01

    There is an urgent need to understand how climate change will impact on demographic parameters of vulnerable species. Migrants are regarded as particularly vulnerable to climate change; phenological mismatch has resulted in the local decline of one passerine, whilst variations in the survival of others have been related to African weather conditions. However, there have been few demographic studies on trans-Saharan non-passerine migrants, despite these showing stronger declines across Europe than passerines. We therefore analyse the effects of climate on the survival and productivity of common sandpipers Actitis hypoleucos, a declining non-passerine long-distant migrant using 28 years' data from the Peak District, England. Adult survival rates were significantly negatively correlated with winter North Atlantic Oscillation (NAO), being lower when winters were warm and wet in western Europe and cool and dry in northwest Africa. Annual variation in the productivity of the population was positively correlated with June temperature, but not with an index of phenological mismatch. The 59% population decline appears largely to have been driven by reductions in adult survival, with local productivity poorly correlated with subsequent population change, suggesting a low degree of natal philopatry. Winter NAO was not significantly correlated with adult survival rates in a second, Scottish Borders population, studied for 12 years. Variation in climatic conditions alone does not therefore appear to be responsible for common sandpiper declines. Unlike some passerine migrants, there was no evidence for climate-driven reductions in productivity, although the apparent importance of immigration in determining local recruitment complicates the assessment of productivity effects. We suggest that further studies to diagnose common sandpiper declines should focus on changes in the condition of migratory stop-over or wintering locations. Where possible, these analyses should be repeated

  20. Understanding linkages between global climate indices and terrestrial water storage changes over Africa using GRACE products.

    Science.gov (United States)

    Anyah, R O; Forootan, E; Awange, J L; Khaki, M

    2018-09-01

    Africa, a continent endowed with huge water resources that sustain its agricultural activities is increasingly coming under threat from impacts of climate extremes (droughts and floods), which puts the very precious water resource into jeopardy. Understanding the relationship between climate variability and water storage over the continent, therefore, is paramount in order to inform future water management strategies. This study employs Gravity Recovery And Climate Experiment (GRACE) satellite data and the higher order (fourth order cumulant) statistical independent component analysis (ICA) method to study the relationship between terrestrial water storage (TWS) changes and five global climate-teleconnection indices; El Niño-Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), Madden-Julian Oscillation (MJO), Quasi-Biennial Oscillation (QBO) and the Indian Ocean Dipole (IOD) over Africa for the period 2003-2014. Pearson correlation analysis is applied to extract the connections between these climate indices (CIs) and TWS, from which some known strong CI-rainfall relationships (e.g., over equatorial eastern Africa) are found. Results indicate unique linear-relationships and regions that exhibit strong linkages between CIs and TWS. Moreover, unique regions having strong CI-TWS connections that are completely different from the typical ENSO-rainfall connections over eastern and southern Africa are also identified. Furthermore, the results indicate that the first dominant independent components (IC) of the CIs are linked to NAO, and are characterized by significant reductions of TWS over southern Africa. The second dominant ICs are associated with IOD and are characterized by significant increases in TWS over equatorial eastern Africa, while the combined ENSO and MJO are apparently linked to the third ICs, which are also associated with significant increase in TWS changes over both southern Africa, as well as equatorial eastern Africa. Copyright © 2018

  1. Scottish Sea Lochs: High Resolution Archives of North Atlantic Climate

    Science.gov (United States)

    Norgaard-Pedersen, N.; Austin, W. E.; Cage, A. G.; Shimmield, T. M.; Gillibrand, P. A.

    2002-12-01

    The sea lochs (fjords) of NW Scotland bridge the land-ocean interface in a region of Europe which is particularly well situated to monitor changes in westerly air flow. Inter-annual atmospheric circulation changes at this latitude are largely governed by the North Atlantic Oscillation (NAO), in turn influencing both westerlies and precipitation. Comparing two extreme recent NAO years, circulation modelling results from Loch Sunart, NW Scotland, reveal a clear response to freshwater runoff and wind forcing in both magnitude and rate of deep-water renewal events. Scottish fjords, because of the relatively small impact which salinity has on d18Owater (0.18 % per salinity unit), potentially provide NW Europe's most useful study sites in coastal palaeoclimate research, particularly where palaeotemperature is the primary record of interest. New data from a high-resolution record (7 yr sample resolution), spanning the last two millennia, from the deepest part of the main basin of Loch Sunart illustrate significant multi-decadal to centennial scale variability in the sedimentary and stable isotope record of epibenthic foraminifera Cibicides lobatulus. The long-term pattern in benthic d18O appears to reflect bottom water temperature differences of 1-2§C, resolving climatic periods such as the Medieval Warm Period and the Little Ice Age. Since the core site is connected with shelf waters (i.e. no shallow sill) it seems likely that this paleotemperature reflects changing shelf water, not the exchange process as a function of long-term runoff/wind forcing. Grain size data and XRF data point to catchment-wide responses (weathering and erosion) which appear to show the largest variability during the last millennium, driven either by rainfall and temperature and/or land-use. Pb-isotope data, constraining the modern and industrial period, suggest accelerated sedimentation rates over this interval. On-going work attempts to calibrate proxy data with instrumental historical data.

  2. Bottom-up effects of climate on fish populations: data from the Continuous Plankton Recorder

    DEFF Research Database (Denmark)

    Pitois, S.G.; Lynam, C.P.; Jansen, Teunis

    2012-01-01

    The Continuous Plankton Recorder (CPR) dataset on fish larvae has an extensive spatio-temporal coverage that allows the responses of fish populations to past changes in climate variability, including abrupt changes such as regime shifts, to be investigated. The newly available dataset offers...... in the plankton ecosystem, while the larvae of migratory species such as Atlantic mackerel responded more to hydrographic changes. Climate variability seems more likely to influence fish populations through bottom-up control via a cascading effect from changes in the North Atlantic Oscillation (NAO) impacting...... with fishing effects interacting with climate effects and this study supports furthering our under - standing of such interactions before attempting to predict how fish populations respond to climate variability...

  3. Case for diagnosis Caso para diagnóstico

    Directory of Open Access Journals (Sweden)

    Gláucia Thomas Heckler

    2012-10-01

    Full Text Available Papular-purpuric gloves and socks syndrome is a rare, highly contagious dermatosis caused by parvovirus B19, which may result in the abrupt cessation of red blood cell production in patients with preexisting hematological diseases. It affects predominantly children and young adults and has an unusual presentation.A síndrome "gloves and socks" pápulo-purpúrica é uma dermatose incomum, altamente contagiosa, causada pelo parvovírus B19, que pode provocar interrupção aguda da produção de glóbulos vermelhos em pacientes com doenças hematológicas preexistentes. Acomete, principalmente, crianças e jovens, e tem uma apresentaçao nao-usual.

  4. Electrodeposition: Principles, Applications and Methods

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Ying, K.K.; Khuan, N.I.

    2011-01-01

    Electrodeposition technique has been around for a very long time. It is a process of coating a thin layer of one metal on top of a different metal to modify its surface properties, by donating electrons to the ions in a solution. This bottom-up fabrication technique is versatile and can be applied to a wide range of potential applications. Electrodeposition is gaining popularity in recent years due to its capability in fabricating one-dimensional nano structures such as nano rods, nao wires and nano tubes. In this paper, we present an overview on the fabrication and characterization of high aspect ratio nano structures prepared using the nano electrochemical deposition system set up in our laboratory. (author)

  5. Decadal changes of weather types in the alpine region

    Energy Technology Data Exchange (ETDEWEB)

    Stefanicki, G.; Talkner, P.; Weber, R.O. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The annual occurrence of different weather types of Schuepp`s synoptic classification in the Alpine region has changed since the beginning of its recording 1945. The annual frequency (number of days) of convective types has increased and that of advective types has decreased. In parallel the number of long-lasting convective episodes rose and the number of long-lasting advective episodes lessened. Most of the change took place in winter. The frequencies of different weather types and the annual mean of certain meteorological parameters are significantly correlated. Moreover, there is a strong interdependence between the subclass of high pressure types and the North Atlantic Oscillation (NAO) index. (author) 3 figs., 3 refs.

  6. Project Paleonao: How know the pattern of the rains. Spanish and Portuguese researchers reconstruct the climatic evolution of the North; Proyecto paleonao: como conocer el patron de las lluvias

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, A.

    2015-07-01

    NAO, the effect of the North Atlantic oscillation, is the difference of air pressure between Iceland and the Azores, and that which governs climate variation every twelve months. To study and understand this phenomenon, which determines the arrival or not of the rains and influence on marine and terrestrial ecosystems are It launched the Paleonao Project. Based on historical weather records, its researchers use sensors natural lakes to collect data. is the case of the Penalara glacial lagoon, whose sediments they allow to know the evolution of the climate since thousands of years and to observe long-term trends of what will eventually passing in terms of precipitation and temperature changes. (Author)

  7. Dynamical systems with constraints: applications to the non-holonomical systems and the string theory

    International Nuclear Information System (INIS)

    Negri, L.J.

    1982-01-01

    A tecnique permiting the construction of a lagrangian function for nao-holononic systems is established. The classical formalism of the relativistic strings is discussed in the point of view of the Dirac theory for singular systems and in the context of a problem of two-dimensional surface immersion in space-time. It is shown how to solve the problem corresponding to the immersion in the case of free-finite and open strings by the specification of a non-conventional gauge. The relation between the string theory and Maxwell fields of place 2 is analyzed and the properties of string 'current density' to obtain new information about the model is explored. (L.C.) [pt

  8. Quality assurance of medical education in the Netherlands: programme or systems accreditation?

    Science.gov (United States)

    Hillen, Harry F P

    2010-01-01

    Accreditation is an instrument that is used worldwide to monitor, maintain and improve the quality of medical education. International standards have been defined to be used in reviewing and evaluating the quality of education. The organization and the process of accreditation of medical education programmes in the Netherlands and in Flanders are described in some detail. Accreditation can be based on the results of a detailed assessment of an educational programme or on an evaluation of the educational system and the organization of the institution in question. The Flemish-Dutch accreditation organization (NAO) is moving from programme accreditation towards a combination of programme and systems accreditation. The pros and cons of these two approaches are discussed.

  9. A propagation-separation approach to estimate the autocorrelation in a time-series

    Directory of Open Access Journals (Sweden)

    D. V. Divine

    2008-07-01

    Full Text Available The paper presents an approach to estimate parameters of a local stationary AR(1 time series model by maximization of a local likelihood function. The method is based on a propagation-separation procedure that leads to data dependent weights defining the local model. Using free propagation of weights under homogeneity, the method is capable of separating the time series into intervals of approximate local stationarity. Parameters in different regions will be significantly different. Therefore the method also serves as a test for a stationary AR(1 model. The performance of the method is illustrated by applications to both synthetic data and real time-series of reconstructed NAO and ENSO indices and GRIP stable isotopes.

  10. Non conformance in fittings for critical environmental conditions; Conexoes nao conformes para trabalho em meios criticos

    Energy Technology Data Exchange (ETDEWEB)

    Sgarbi, Mauricio [Promon Engenharia, Sao Paulo, SP (Brazil); Zeemann, Annelise [Tecmetal, Rio de Janeiro, RJ (Brazil)

    2012-07-01

    Carbon steel fittings ASTM A105 and ASTM A234 WPB are widely applied for refinery piping and equipment and the detection, by a construction company, of a fitting manufacturing non conformance (NC) showed to be an unexpected problem of enormous dimension, since part of the plant was in startup conditions, with the NC fittings already welded, hydrostatically tested, painted and, in several lines, already thermally insulated. The challenge of treating the NC in a quick way with 100% confidence was even more difficult due to the metallurgical nature of the problem, not in the expertise of a construction company, which analyzed and decided about changing or accepting about 11,251 fittings of small diameter. This decision could impact directly in the refinery schedule for urgently running the unity. This work shows how the NC was detected, the extension of the problem that required field chemistry and hardness analysis of 7.425 parts, the metallurgical nature of the NC and the adopted treatment, considering that this unity presents aggressive environments and critical conditions like H2S. After a complex metallurgical study it was possible to change only 30% of the NC fittings, although some additional heat treatments were required to assure favorable conditions for piping use. (author)

  11. "Kompyuter" versus "tien-nao" aneb Co stojí Ujgury přístup k prosperitě?

    Czech Academy of Sciences Publication Activity Database

    Klimeš, Ondřej

    2008-01-01

    Roč. 32, č. 7 (2008), s. 16-19 ISSN 0543-7962 Institutional research plan: CEZ:AV0Z90210515 Keywords : Xinjiang * contemporary politics * language policy Subject RIV: AD - Politology ; Political Sciences

  12. Catalytic oxidation of albendazole using molybdenum supported on carbon nanotubes as catalyst; Oxidacion catalitica de albendazol empleando como catalizador molibdeno soportado en nanotubos de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Sun-Kou, Maria del Rosario; Vega Carrasco, Edgar R., E-mail: msun@pucp.edu.pe [Departamento de Ciencias, Seccion Quimica. Pontificia Universidad Catolica del Peru, Avenida Universitaria 1801, Lima (Peru); Picasso Escobar, Gino I. [Laboratorio de Investigacion de Fisicoquimica, Facultad de Ciencias, Universidad Nacional de Ingenieria, Avenida Tupac Amaru 210, Lima (Peru)

    2013-10-15

    The catalytic oxidation reaction of the thioether group (-S-) in the structure to the drug albendazole (C{sub 12}H{sub 15}N{sub 3}O{sub 2}S) was studied in order to obtain a pharmacologically active molecule known as albendazole sulfoxide. With this purpose, three heterogeneous catalysts were prepared using molybdenum (Mo) as active phase and carbon nanotubes as a multiple-layer catalyst support. The incorporation of the active phase was performed by wet impregnation, with subsequent calcination for 4 hours at 400 {sup o}C. For the catalytic oxidation reaction was employed hydrogen peroxide-urea (H{sub 2}NCONH{sub 2}·H{sub 2}O{sub 2}) as oxidizing agent and methanol (CH{sub 3}OH) as reaction medium. The textural and morphology characterization of carbon nanoparticles and catalysts was carried out by adsorption-desorption of N{sub 2} (BET) and scanning electron microscopy (SEM). The identification and quantification of the reaction products were followed by Fourier transform infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC), respectively. With the yield, selectivity and conversion higher than 90% after 60 minutes of reaction, albendazole sulphoxide was obtained as major product of oxidation reaction. (author)

  13. Recent drying of the Fertile Crescent: natural or externally forced?

    Science.gov (United States)

    Kelley, Colin

    2014-05-01

    There has been a reduction in observed precipitation over the greater Mediterranean region since the middle of the 20th Century. Recent studies suggest that while anthropogenic forcing has already begun to assert itself in recent decades, the preponderance of the winter drying trend is attributable to the large natural multidecadal variability of the North Atlantic Oscillation (NAO), while over the eastern Mediterranean, the anthropogenic, or forced drying signal is more clearly evident. This forced drying is projected to increase during the 21st Century according to the newest global climate models and this aridification would present significant challenges for a region that is already water-stressed. Although the Fertile Crescent is historically known for its agricultural prosperity, the severity and persistence of the recent multiyear drought in Syria, directly prior to the 2011 uprising there, leads us to ask whether this is evidence of emerging global warming influence. This drought exacerbated existing water insecurity, resulting in an agricultural collapse and a mass migration of rural drought refugees to the urban areas in Syria's west. This migration followed the previous influx of Iragi refugees and combined with strong natural population growth to place a severe strain on resources. Here we examine observations of precipitation and temperature, both gridded and stations, along with simulations and projections from the newest global climate models, to estimate the forced contribution to the recent Syrian drought, and assess the uncertainty in future drying according to the models. We find that this region has experienced a long-term downward trend in precipitation, and a concomitant increase in temperature, serving to further dry the soil, and in surface pressure. We find that the shift in the distributions of three-year running means of surface pressure and precipitation due to the forcing make severe events such as the recent Syrian drought several

  14. Sea level reconstruction from satellite altimetry and tide gauge data

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde; Andersen, Ole Baltazar; Nielsen, Allan Aasbjerg

    2012-01-01

    Ocean satellite altimetry has provided global sets of sea level data for the last two decades, allowing determination of spatial patterns in global sea level. For reconstructions going back further than this period, tide gauge data can be used as a proxy. We examine different methods of combining...... for better sensitivity analysis with respect to spatial distribution, and tide gauge data are available around the Arctic Ocean, which may be important for a later high-latitude reconstruction....... satellite altimetry and tide gauge data using optimal weighting of tide gauge data, linear regression and EOFs, including automatic quality checks of the tide gauge time series. We attempt to augment the model using various proxies such as climate indices like the NAO and PDO, and investigate alternative...

  15. Sea level reconstruction: Exploration of methods for combining altimetry with other data to beyond the 20-year altimetric record

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde; Andersen, Ole Baltazar; Nielsen, Allan Aasbjerg

    2012-01-01

    Ocean satellite altimetry has provided global sets of sea level data for the last two decades, allowing determination of spatial patterns in global sea level. For reconstructions going back further than this period, tide gauge data can be used as a proxy for the model. We examine different methods...... to spatial distribution, and tide gauge data are available around the Arctic Ocean, which may be important for a later high-latitude reconstruction....... of combining satellite altimetry and tide gauge data using optimal weighting of tide gauge data, linear regression and EOFs, including automatic quality checks of the tide gauge time series. We attempt to augment the model using various proxies such as climate indices like the NAO and PDO, and investigate...

  16. Physical and morphological properties of alumina powders synthesized through sol-gel method

    International Nuclear Information System (INIS)

    Julie Andrianny Murshidi; Choo Thye Foo; Che Seman Mahmood; Meor Yusof Meor Sulaiman

    2006-01-01

    Aluminum oxide powders were prepared by the hydrolysis of aluminum isopropoxide catalysed by hydrochloric acid and in the presence of Sodium Lauryl Sulphate C 1 2H 2 5NaO 4 S as a surface stabilizing agent. After ageing for 24 hours the gel-like products were filtered and calcined at 1200 degree C. The effect of initial concentration of the aluminum precursor, aluminum isopropoxide (0.2 M, 0.1 M, 0.05 M and 0.03 M) and ageing temperature of 28 degree C, 50 degree C, 70 degree C, 85 degree C and 95 degree C on particle size of the powder were studied using Particle Size Analyzer. Shape and morphology of the particles were characterized by using Scanning Electron Microscope (SEM). (Author)

  17. Asian Slavery in the Viceroyalty of New Spain, 1565-1673

    Directory of Open Access Journals (Sweden)

    Déborah Oropeza Keresey

    2011-07-01

    Full Text Available When a continuous communication was established between the center of the Viceroyalty of New Spain and its Asian Audiencia in the Philippines thanks to the Nao of China, there appeared a transpacific migration of Asian slaves travelling to the center of the viceroyalty between 1656 and 1673. In this paper, I analyze the evolution and characteristics of this type of migration, including the various procedures of slave transportation, the scope of the migratory movement, as well as the different origins of Asian slaves. I also examine the kind of work undertaken by Asian slaves in the center of the Novohispanic viceroyalty. Finally, I consider the freedom process of these slaves, which took place during the second half of the 17th century.

  18. Pesquisa de adocantes não calóricos sintéticos em adoçante natural de Stevia rebaudiana (Bert. Bertoni

    Directory of Open Access Journals (Sweden)

    Mariangela T. Auricchio

    Full Text Available Foram analisadas 19 amostras de "Adoçantes Natu rais de Stevia", tendo por objetivo verificar-se a presença de outros adoçantes nao calóricos sintéticos que não são declarados no rótulo do produto. Constatou-se que em 18 amostras,além de componentes do extrato de Stevia reubadiana (Bert. Bertoni, a sacarina estava presente e que só uma delas declarava tal fato no rótulo. Em três dessas amostras foi encontrado tanbém aspartame e em uma, ciclamato. Fimalmente, em uma amostra não foi encontrado nenhum componente do extrato de Stevia rebaudiana (Bert. Bertoni, mas sim uma mistuna de manitol e aspartame.

  19. Morfología de la primera zoea de los cangrejos marinos Petrolisthes haigae y P. nobilii (Decapoda: Porcellanidae

    Directory of Open Access Journals (Sweden)

    Gonzalo Hernández

    2007-12-01

    Full Text Available Los "cangrejos porcelana" Petrolisthes haigae Chace 1962 y P. nobilii Haig 1960, son especies de aguas poco profundas distribuidas a lo largo de las costas del Pacífico Este Tropical. Recolectamos larvas de ambas especies, de ocho y cuatro hembras, en las islas de Taboga y Naos, respectivamente. Las criamos en el laboratorio para describir e ilustrar los primeros estados de zoea de estas especies fueron, hasta ahora desconocidos. Las comparamos con los primeros estadios de zoea de otras especies del género en el oeste de Panamá y concluimos que las características de la primera zoea de ambas especies se asemejan a las del grupo 4 de larvas propuesto por Osawa en 2002.

  20. Prevention of childhood obesity through motivation to physical activity

    Directory of Open Access Journals (Sweden)

    Carrillo Aguilera, Sonia

    2012-07-01

    Full Text Available This paper aims to review the current worrying situation in terms of physical activity in our country and the problem that leads us to be below the European average, with the attendant problems of obesity, particularly among children, which follow from this. We analyzed the intervention programs that are being used as PIOBIN plan (The Andalusian Plan for Childhood Obesity, effective from 2007-12, based on a national strategy called Naos Strategy and how different studies support that some intrinsic motivation toward physical activity helps to create lasting habits to the practice. We also carry out an analysis of the different Motivation theories and we base our study on the Self-determination Theory of Deci and Ryan (1985, 2000

  1. Results of modern processing of the photographic observations of Uranus and Neptune from Archives of UkrVO

    Science.gov (United States)

    Protsyuk, Yu. I.; Kovylianska, O. E.; Protsyuk, S. V.; Yizhakevych, O. M.; Andruk, V. M.; Golovnia, V. V.; Yuldoshev, Q. K.

    2017-02-01

    The bulk of planet observations was obtained in RI MAO and MAO NASU from 1961 to 1994. Plates from AI UAS were also used. Each plate of NAO was scanned 6 times, in other observatories - only once. All images are processed, most of them are identified and the equatorial coordinates of all objects were obtained. Positional accuracy of the reference stars has value of 0.04"-0.30". Standard deviation of the planets' position is in the range 0.10-0.12 pixels, that corresponds, depending on the scale, from 0".08 to 0".26. The comparison of the new topocentric positions of the planets with JPL/HORIZONS ephemeris was made. Calculation of (O-C) values and their standard deviation is obtained.

  2. The use of Fuzzy expert system in robots decision-making

    International Nuclear Information System (INIS)

    Jamaseb, Mehdi; Jafari, Shahram; Montaseri, Farshid; Dadgar, Masoud

    2014-01-01

    The main issue that is investigated in this paper, is a method for decision making of mobile robots in different conditions for this purpose, we have used expert system. In this way, that the conditions of the robot are analyzed by on expert person a special issue (like following a ball) using knowledge base and suitable decisions will be mode. Then, using this information fuzzy rules well be built, and using its rules, robots decisions can be implemented like an expert person. In this study, we have used delta3d base for implementing expert systems and CLIPS and also we have used NAO for simulation rcssserver3d robot and 3d football simulation have been used for implementing operation program

  3. Recent Studies on Attributions of Climate Change in China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zongci; DING Yihui; LUO Yong; Wang Shaowu

    2005-01-01

    Attributions of floods/cooler along the Yangtze River Valley and droughts/warmer in North China for the last 25 years have been reviewed in this paper. Both natural climate variability and human activities are considered. Some stronger evidences contributed to the natural climate variability, such as decadal and interdecadal variabilities of East Asian summer monsoon, the periodicities and transitions of rainfall and temperature changes in China, abrupt climate change, NAO, AO, AAO, ENSO, and snow cover. The signals produced by the human activities such as greenhouse gases and "brown clouds" likely play the role for the patterns. But the physical feedbacks and mechanisms still keep ambiguous and vague. More researches should be carried out in future to solve this issue.

  4. Cultura e natureza: a viagem e o turismo como necessidades humanas

    Directory of Open Access Journals (Sweden)

    Silvio Lima Figueiredo

    2014-12-01

    Full Text Available O artigo analisa os conceitos e práticas da viagem e do turismo baseado nas discussões sobre as características do fenômeno e de sua gênese. A viagem é então entendida a partir dos estudos da natureza e da cultura e como essas duas categorias se relacionam entre si, de acordo com os estudos antropológicos de Malinowski, Claude Levi-Strauss e Clifford Geertz. É evidenciada a interpretação da viagem como universal cultural, no entanto, nao se pode entendê-la como um aspecto da “natureza humana”. O turismo é entendido como um tipo de viagem cuja origem e características surgiram no mundo moderno.

  5. Quality assurance of medical education in the Netherlands: programme or systems accreditation? [

    Directory of Open Access Journals (Sweden)

    Hillen, Harry F. P.

    2010-04-01

    Full Text Available [english] Accreditation is an instrument that is used worldwide to monitor, maintain and improve the quality of medical education. International standards have been defined to be used in reviewing and evaluating the quality of education. The organization and the process of accreditation of medical education programmes in the Netherlands and in Flanders are described in some detail. Accreditation can be based on the results of a detailed assessment of an educational programme or on an evaluation of the educational system and the organization of the institution in question. The Flemish-Dutch accreditation organization (NAO is moving from programme accreditation towards a combination of programme and systems accreditation. The pros and cons of these two approaches are discussed.

  6. Interaction of molecular oxygen with single wall nanotubes: Role of surfactant contamination

    International Nuclear Information System (INIS)

    Larciprete, R.; Goldoni, A.; Lizzit, S.

    2003-01-01

    The interaction of molecular oxygen with single wall nanotubes in the form of a commercial bucky paper was investigated by high resolution photoemission spectroscopy. Sodium contamination was found in the sample, which was completely removed only after prolonged heating at 1250 K. The C 1s core level spectrum measured on the sample annealed to 1020 K dramatically changed upon exposure to molecular oxygen. On the contrary, when exposing the Na-free SWNTs to several KL of O 2 , the sample remained oxygen free and no modification in the C 1s core level was observed. Therefore the observed sensitivity of the sample to O 2 was due to a Na mediated oxidation, determining a charge transfer from the C tubes to the Na-O complex

  7. Representações sociais dos usuários hospitalizados sobre cidadania: implicações para o cuidado hospitalar

    Directory of Open Access Journals (Sweden)

    Flávia Pacheco de Araújo

    2016-08-01

    Full Text Available RESUMO Objetivo: analisar as representacoes sociais de usuarios hospitalizados sobre a cidadania no cuidado hospitalar. Método: abordagem qualitativa com referencial da Teoria das Representacoes Sociais, realizada com 31 usuarios hospitalizados no setor de clinica medica de um hospital publico, universitario. Realizou-se entrevista semiestruturada, cujos dados foram submetidos ao programa Alceste, com aplicacao de analise lexical. Resultados: os usuarios conhecem os seus direitos, e a cidadania no cuidado e entendida a luz dos direitos a saude, de modo que sejam bem atendidos do ponto de vista tecnico e humano. Conclusão: o bom trato relacional e a prestacao do cuidado tecnico-procedimental sao direitos dos usuarios; logo, a ausência de um ou de outra implica o nao respeito a sua cidadania.

  8. Low Frequency Modulation of Extreme Temperature Regimes in a Changing Climate

    Energy Technology Data Exchange (ETDEWEB)

    Black, Robert X. [Georgia Inst. of Technology, Atlanta, GA (United States)

    2014-11-24

    The project examines long-term changes in extreme temperature episodes (ETE) associated with planetary climate modes (PCMs) in both the real atmospheric and climate model simulations. The focus is on cold air outbreaks (CAOs) and warm waves (WWs) occurring over the continental US during the past 60 winters. No significant long-term trends in either WWs or CAOs are observed over the US. The annual frequency of CAOs is affected by the (i) North Atlantic Oscillation (NAO) over the Southeast US and (ii) Pacific–North American (PNA) pattern over the Northwest US. WW frequency is influenced by the (i) NAO over the eastern US and (ii) combined influence of PNA, Pacific decadal oscillation (PDO), and ENSO over the southern US. The collective influence of PCMs accounts for as much as 50% of the regional variability in ETE frequency. During CAO (WW) events occurring over the southeast US, there are low (high) pressure anomalies at higher atmospheric levels over the southeast US with oppositely-signed pressure anomalies in the lower atmosphere over the central US. These patterns lead to anomalous northerly (for CAOs) or southerly (for WWs) flow into the southeast leading to cold or warm surface air temperature anomalies, respectively. One distinction is that CAOs involve substantial air mass transport while WW formation is more local in nature. The primary differences among event categories are in the origin and nature of the pressure anomaly features linked to ETE onset. In some cases, PCMs help to provide a favorable environment for event onset. Heat budget analyses indicate that latitudinal transport in the lower atmosphere is the main contributor to regional cooling during CAO onset. This is partly offset by adiabatic warming associated with subsiding air. Additional diagnoses reveal that this latitudinal transport is partly due to the remote physical influence of a shallow cold pool of air trapped along the east side of the Rocky Mountains. ETE and PCM behavior is also

  9. Quantum effects due to coordinate non-inertial systems; Efeitos quanticos devidos a sistemas nao inerciais de coordenadas

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Daniel

    1996-12-31

    In chapter 1 we make an introduction to quantum fields in curved spaces, mentioning something about fermions. Chapter 2 begins a brief introduction to General Relativity, and the calculation of the linearized limit to obtain Thirring`s metric, which is a first approximation to the Kerr metric. In Chapter 3 we calculate Dirac`s equation in Thirring`s space-time and work out the non relativistic limit obtaining the modifications in Schroedinger`s equation resulting from the geometry. Particularly, we observe the interference of a particle beam. And in Chapter 4, we present a revision of classical and quantum detectors and discuss the response of detectors in non-inertial motion, in particular, for uniform acceleration and uniform circular motion. The latter is known to yield and integral for the response function which has been so far carried out only numerically. We propose a semi-analytical solution for the spectrum of a circular moving detector. We consider c=1. (author) 27 refs., 4 figs.

  10. Extracting climate signals from large hydrological data cubes using multivariate statistics - an example for the Mediterranean basin

    Science.gov (United States)

    Kauer, Agnes; Dorigo, Wouter; Bauer-Marschallinger, Bernhard

    2017-04-01

    Global warming is expected to change ocean-atmosphere oscillation patterns, e.g. the El Nino Southern Oscillation, and may thus have a substantial impact on water resources over land. Yet, the link between climate oscillations and terrestrial hydrology has large uncertainties. In particular, the climate in the Mediterranean basin is expected to be sensitive to global warming as it may increase insufficient and irregular water supply and lead to more frequent and intense droughts and heavy precipitation events. The ever increasing need for water in tourism and agriculture reinforce the problem. Therefore, the monitoring and better understanding of the hydrological cycle are crucial for this area. This study seeks to quantify the effect of regional climate modes, e.g. the Northern Atlantic Oscillation (NAO) on the hydrological cycle in the Mediterranean. We apply Empirical Orthogonal Functions (EOF) to a wide range of hydrological datasets to extract the major modes of variation over the study period. We use more than ten datasets describing precipitation, soil moisture, evapotranspiration, and changes in water mass with study periods ranging from one to three decades depending on the dataset. The resulting EOFs are then examined for correlations with regional climate modes using Spearman rank correlation analysis. This is done for the entire time span of the EOFs and for monthly and seasonally sampled data. We find relationships between the hydrological datasets and the climate modes NAO, Arctic Oscillation (AO), Eastern Atlantic (EA), and Tropical Northern Atlantic (TNA). Analyses of monthly and seasonally sampled data reveal high correlations especially in the winter months. However, the spatial extent of the data cube considered for the analyses have a large impact on the results. Our statistical analyses suggest an impact of regional climate modes on the hydrological cycle in the Mediterranean area and may provide valuable input for evaluating process

  11. Spatial observation and monitoring of the effects of the "New Climate" Warming on Morocco: Situation of the recent urban floods

    Science.gov (United States)

    Karrouk, M. S.

    2017-12-01

    Since the nineties of the last century, climatological research following a great scientific advance in the field of prediction, not the variability and evolution of the different climatic parameters was beginning to be clearer!But today, since the beginning of 2005, certainly due to oceanic thermal cumulations, and the shift of climatic zones towards poles in selective forms (more intense on the oceans present on the continents); Climatic events do not evolve according to the usual and expected rhythms: atmospheric circulation, precipitation, temperatures, seasonal phenomena, etc. These conditions are a spatiotemporal evolution and distribution, which characterize the new "global climate", by the new atmospheric regime imposing the Meridian Atmospheric Circulation (MAC), alternating the conditions of Freshness (humidity) and Heat (drought) along the year.In this new situation, Morocco, located in the climate transition zone, is fully affected by the "New Climate". Usually, the atmospheric response to major climatic events (ENSO) in this region such as "El Niño" was characterized by the establishment of the NAO positive index, stability and drought, due to dominance Zonal Atmospheric Circulation in winter. On the other hand, in the "La Niña" episode, the negative index of the NAO and the predominant Meridian Atmospheric Circulation and precipitation became abundant.Since the beginning of this century, qualified meteorological events of "exceptional !" causing floods have continued to occur in Morocco and elsewhere, with increasing recurrence, prompting us to wonder about the "new" mode of hydro-thermal function of the climate system that induces torrential rains, as well as its effect on environments and societies.The latest event is the flood disaster in October 2016 in the Laâyoune region of southern Morocco, which specializes in the unusual return of rain in a region considered dry and Saharan.Thanks to spatial observation and monitoring of meteorological

  12. High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert.

    Science.gov (United States)

    Weijers, Stef; Buchwal, Agata; Blok, Daan; Löffler, Jörg; Elberling, Bo

    2017-11-01

    Rapid climate warming has resulted in shrub expansion, mainly of erect deciduous shrubs in the Low Arctic, but the more extreme, sparsely vegetated, cold and dry High Arctic is generally considered to remain resistant to such shrub expansion in the next decades. Dwarf shrub dendrochronology may reveal climatological causes of past changes in growth, but is hindered at many High Arctic sites by short and fragmented instrumental climate records. Moreover, only few High Arctic shrub chronologies cover the recent decade of substantial warming. This study investigated the climatic causes of growth variability of the evergreen dwarf shrub Cassiope tetragona between 1927 and 2012 in the northernmost polar desert at 83°N in North Greenland. We analysed climate-growth relationships over the period with available instrumental data (1950-2012) between a 102-year-long C. tetragona shoot length chronology and instrumental climate records from the three nearest meteorological stations, gridded climate data, and North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) indices. July extreme maximum temperatures (JulT emx ), as measured at Alert, Canada, June NAO, and previous October AO, together explained 41% of the observed variance in annual C. tetragona growth and likely represent in situ summer temperatures. JulT emx explained 27% and was reconstructed back to 1927. The reconstruction showed relatively high growing season temperatures in the early to mid-twentieth century, as well as warming in recent decades. The rapid growth increase in C. tetragona shrubs in response to recent High Arctic summer warming shows that recent and future warming might promote an expansion of this evergreen dwarf shrub, mainly through densification of existing shrub patches, at High Arctic sites with sufficient winter snow cover and ample water supply during summer from melting snow and ice as well as thawing permafrost, contrasting earlier notions of limited shrub growth sensitivity to

  13. Interannual Variation in Phytoplankton Class-Specific Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile Severine; Gregg, Watson W.

    2014-01-01

    We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of 4 phytoplankton groups to the total primary production. First we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms were the group that contributed the most to the total phytoplankton production (50, the equivalent of 20 PgC y-1. Coccolithophores and chlorophytes each contributed to 20 (7 PgC y-1 of the total primary production and cyanobacteria represented about 10 (4 PgC y(sub-1) of the total primary production. Primary production by diatoms was highest in high latitude (45) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4 (1-2 PgC y-1. We assessed the effects of climate variability on the class-specific primary production using global (i.e. Multivariate El Nio Index, MEI) and regional climate indices (e.g. Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p 0.05) between the MEI and the class-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatomscyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect on the class-specific primary production in the Southern Ocean. These results provide a modeling and

  14. Health in All Policies (HiAP) governance: lessons from network governance.

    Science.gov (United States)

    Khayatzadeh-Mahani, Akram; Ruckert, Arne; Labonté, Ronald; Kenis, Patrick; Akbari-Javar, Mohammad Reza

    2018-05-25

    The Health in All Policies (HiAP) approach requires formal and sustained governance structures and mechanisms to ensure that the policies of various non-health sectors maximize positive and minimize negative impacts on population health. In this paper, we demonstrate the usefulness of a network perspective in understanding and contributing to the effectiveness of HiAP. We undertook an exploratory, qualitative case study of a HiAP structure in Iran, the Kerman province Council of Health and Food Security (CHFS) with diverse members from health and non-health sectors. We analyzed relevant policy texts and interviewed 32 policy actors involved in the CHFS. Data were analyzed using within-case analysis and constant comparative methodology. Our findings suggest that CHFS governance from a network perspective drew in practice on elements of two competing network governance modes: the network administrative organization (NAO) and the lead organization mode. Our results also show that a shift from a hierarchical and market-based mode of interaction to a network logic within CHFS has not yet taken place. In addition, CHFS suffers from large membership and an inability to address complex 'wicked problems', as well as low trust, legitimacy and goal consensus among its members. Drawing on other HiAP studies and commentaries, insights from organization network theory, and in-depth findings from our case study, we conclude that a NAO may be the most effective mode of governance for tackling complex social problems in HiAP structures. Since similar studies are limited, and our single case study may not be transferable across all contexts, we suggest that further research be undertaken to explore HiAP structures from a network perspective in different institutional and cultural settings. With increasing emphasis given to HiAP approaches in national and international health policy discourse, it is important that comparative knowledge about the effectiveness of HiAP governance

  15. EFFECT OF AURICULAR ACUPUNCTURE ON THE LEARNING AND MEMORY AND bcl-2 EXPRESSION IN VASCULAR DEMENTIA RATS

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xuezhao; XIAO Maolei; SUN Guojie

    2002-01-01

    Objective: To study the effect of auricular acupuncture on dysmnesia and the relationship between the memory improvement and bcl-2 protein expression in vascular dementia (VD) rats. Methods: Forty Wistar rats were randomized into control group, VD group, acupuncture+ VD group and pseudo-operation group, with 10 cases in each group. Rat VD model was established by using 4-vessel occlusion method. Otopoint "Nao"-point and "Shen"(MA-SC)were punctured, once daily continuously for 15 days. The rats' memory capability was tested with Y-maze method and bcl-2 expression of the brain tissues displayed by immunohistochemical method and measured using MIAS-2000 Image Analyzer. Results: Results showed that the scores of control group, VD group and acupuncture+ VD group before operation were 5.68±1.29, 6.07±1.67 and 5.86±1.74 respectively, while following auricular acupuncture treatment,the scores of the 3 groups were 5.81±1.51, 18.06±2.68 and 8.31 ± 1.85 separately, suggesting that the VD rat's learning and memory abilities in acupuncture+ VD group were raised apparently in comparison with those of VD group (P < 0.01 ). In control, VD and acupuncture+VD group, bcl-2 immuno-reaction positive neurons in CA1 area of the hippocampus were 14.31 ± 4.87, 28.67 ± 5.63 and 65.74 ± 8.19 respectively, displaying that the improvement of learning and memory abilities caused by auricular acupuncture treatment may be related to the up-regulation of bcl-2expression (an inhibitory gene of apoptosis). In comparison with control group, the loss of neurons in the pyramidal cell layer of the hippocampal CA1 area of VD group was more severe, while that of acupuncture group was markedly lighter. Conclusion: Auricular acupuncture of otopoint "Nao"-point and "Shen" (MA-SC) can raise the learning and memory abilities of VD rats, which may be realized by its inhibitory effect on apoptosis and the protection action on ischemic hippocampal neurons.

  16. Response of planktonic cladocerans (Class: Branchiopoda) to short-term changes in environmental variables in the surface waters of the Bay of Biscay

    Science.gov (United States)

    d'Elbée, Jean; Lalanne, Yann; Castège, Iker; Bru, Noelle; D'Amico, Frank

    2014-08-01

    From January 2001 to December 2008, 73 surface plankton samples and 45 vertical profiles of sea temperature, salinity, dissolved oxygen and pH were collected on a monthly basis from a single sampling station located in the Bay of Biscay (43°37N; 1°43W) (North-East Atlantic). Two types of North Atlantic Oscillation (NAO) indexes were included in the data set and submitted to a Canonical Correspondence Analysis and Spearman non-parametric test. Significant breaks and levels in time series were tested using a data segmentation method. The temperature range varies from 11 °C to 25 °C. It begins to rise from April until August and then decline. Low salinity values occur in mid-spring (36 PSU) in autumn. Dissolved oxygen mean values were around 8 mg/l. In summer, when temperature and salinity are high, surface water layer is always accompanied with a significant deoxygenation, and the process reverses in winter. pH mean values range was 7.78-8.33. Seasonal and inter-annual variations of the two NAO indexes are strongly correlated to one another, but do not correlate with any hydrological or biological variable. Five of the seven cladocerans species which are present in the Bay of Biscay were found in this study. There is a strong pattern in species succession throughout the year: Evadne nordmanni is a vernal species, while Penilia avirostris and Pseudevadne tergestina occur mainly in summer and autumn. Evadne spinifera has a maximum abundance in spring, Podon intermedius in autumn, but they both occur throughout the year. However, for some thirty years, the presence of species has tended to become significantly extended throughout the year. During the 2001-2008 period, there was a noticeable decline and even a disappearance of the categories involved in sexual reproduction as well as those involved in parthenogenesis, in favor of non-breeding individuals.

  17. Exploring the effects of climatic variables on monthly precipitation variation using a continuous wavelet-based multiscale entropy approach.

    Science.gov (United States)

    Roushangar, Kiyoumars; Alizadeh, Farhad; Adamowski, Jan

    2018-08-01

    North Atlantic Oscillation (NAO), indeces. The results revealed that all climatic features except NAO influenced precipitation in Iran during the 1960-2010 period. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Stretch-dependent slow force response in isolated rabbit myocardium is Na+ dependent.

    Science.gov (United States)

    von Lewinski, Dirk; Stumme, Burkhard; Maier, Lars S; Luers, Claus; Bers, Donald M; Pieske, Burkert

    2003-03-15

    Stretch induces functional and trophic effects in mammalian myocardium via various signal transduction pathways. We tested stretch signal transduction on immediate and slow force response (SFR) in rabbit myocardium. Experiments were performed in isolated right ventricular muscles from adult rabbit hearts (37 degrees C, 1 Hz stimulation rate, bicarbonate-buffer). Muscles were rapidly stretched from 88% of optimal length (L88) to near optimal length (L98) for functional analysis. The resulting immediate and slow increases in twitch force (first phase and SFR, respectively) were assessed at reduced [Na+]o or without and with blockade of stretch activated ion channels (SACs), angiotensin-II (AT1) receptors, endothelin-A (ET(A)) receptors, Na+/H+-exchange (NHE1), reverse mode Na+/Ca2+-exchange (NCX), or Na+/K+-ATPase. The effects of stretch on sarcoplasmic reticulum Ca2+-load were characterized using rapid cooling contractures (RCCs). Intracellular pH was measured in BCECF-AM loaded muscles, and action potential duration (APD) was assessed using floating electrodes. On average, force increased to 216+/-8% of the pre-stretch value during the immediate phase, followed by a further increase to 273+/-10% during the SFR (n=81). RCCs significantly increased during SFR, whereas pH and APD did not change. Neither inhibition of SACs, AT1, or ET(A) receptors affected the stretch-dependent immediate phase nor SFR. In contrast, SFR was reduced by NHE inhibition and almost completely abolished by reduced [Na+]o or inhibition of reverse-mode NCX, whereas increased SFR was seen after raising [Na+]i by Na+/K+-ATPase inhibition. The data demonstrate the existence of a delayed, Na+- and Ca2+-dependent but pH and APD independent SFR to stretch in rabbit myocardium. This inotropic response appears to be independent of autocrine/paracrine AT1 or ET(A) receptor activation, but mediated through stretch-induced activation of NHE and reverse mode NCX.

  19. Quantification of Linkages between Large-Scale Climate Patterns and Annual Precipitation for the Colorado River Basin

    Science.gov (United States)

    Kalra, A.; Ahmad, S.

    2010-12-01

    Precipitation is regarded as one of the key variables driving various hydrologic processes and the future precipitation information can be useful to better understand the long-term climate dynamics. In this paper, a simple, robust, and parsimonious precipitation forecast model, Support Vector Machine (SVM) is proposed which uses large-scale climate information and predict annual precipitation 1-year in advance. SVM’s are a novel class of neural networks (NNs) which are based on the statistical learning theory. The SVM’s has three main advantages over the traditional NNs: 1) better generalization ability, 2) the architecture and weights of SVM’s are guaranteed to be unique and globally optimum, and 3) SVM’s are trained more rapidly than the corresponding NN. With these advantages, an application of SVM incorporating large-scale climate information is developed and applied to seventeen climate divisions encompassing the Colorado River Basin in the western United States. Annual oceanic-atmospheric indices, comprising of Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), and El Nino-Southern Oscillations (ENSO) for a period of 1900-2007 are used to generate annual precipitation estimates with 1-year lead time. The results from the present study indicate that long-term precipitation predictions for the Upper Colorado River Basin can be successfully obtained using a combination of NAO and ENSO indices whereas coupling PDO and AMO results in improved precipitation predictions for the Lower Colorado River Basin. Precipitation predictions from the SVM model are found to be better when compared with the predictions obtained from feed-forward back propagation Artificial Neural Network and Multivariate Linear Regression models. The overall results of this study revealed that the annual precipitation of the Colorado River Basin was significantly influenced by oceanic-atmospheric oscillations and the proposed SVM

  20. Mechanisms of flow and water mass variability in Denmark Strait

    Science.gov (United States)

    Moritz, Martin; Jochumsen, Kerstin; Quadfasel, Detlef; Mashayekh Poul, Hossein; Käse, Rolf H.

    2017-04-01

    The dense water export through Denmark Strait contributes significantly to the lower limb of the Atlantic Meridional Overturning Circulation. Overflow water is transported southwestward not only in the deep channel of the Strait, but also within a thin bottom layer on the Greenland shelf. The flow on the shelf is mainly weak and barotropic, exhibiting many recirculations, but may eventually contribute to the overflow layer in the Irminger Basin by spilling events in the northern Irminger Basin. Especially the circulation around Dohrn Bank and the Kangerdlussuaq Trough contribute to the shelf-basin exchange. Moored observations show the overflow in Denmark Strait to be stable during the last 20 years (1996-2016). Nevertheless, flow variability was noticed on time scales of eddies and beyond, i.e. on weekly and interannual scales. Here, we use a combination of mooring data and shipboard hydrographic and current data to address the dominant modes of variability in the overflow, which are (i) eddies, (ii) barotropic pulsations of the plume, (iii) lateral shifts of the plume core position, and (iv) variations in vertical extension, i.e. varying overflow thickness. A principle component analysis is carried out and related to variations in sea surface height and wind stress, derived from satellite measurements. Furthermore, a test for topographic waves is performed. Shelf contributions to the overflow core in the Irminger Basin are identified from measurements of temperature and salinity, as well as velocity, which were obtained during recent cruises in the region. The flow and water mass pattern obtained from the observational data is compared to simulations in a high resolution regional model (ROMS), where tracer release experiments and float deployments were carried out. The modelling results allow a separation between different atmospheric forcing modes (NAO+ vs NAO- situations), which impact the water mass distribution and alter the dense water pathways on the

  1. Hundred years of environmental change and phytoplankton ecophysiological variability archived in coastal sediments.

    Directory of Open Access Journals (Sweden)

    Sofia Ribeiro

    Full Text Available Marine protist species have been used for several decades as environmental indicators under the assumption that their ecological requirements have remained more or less stable through time. However, a growing body of evidence suggests that marine protists, including several phytoplankton species, are in fact highly diverse and may quickly respond to changes in the environment. Predicting how future climate will impact phytoplankton populations is important, but this task has been challenged by a lack of time-series of ecophysiological parameters at time-scales relevant for climate studies (i.e. at least decadal. Here, we report on ecophysiological variability in a marine dinoflagellate over a 100-year period of well-documented environmental change, by using the sedimentary archive of living cysts from a Scandinavian fjord (Koljö Fjord, Sweden. During the past century, Koljö Fjord has experienced important changes in salinity linked to the North Atlantic Oscillation (NAO. We revived resting cysts of Pentapharsodinium dalei preserved in the fjord sediments and determined growth rates for 18 strains obtained from 3 sediment core layers at salinity 15 and 30, which represent extreme sea-surface conditions during periods of predominantly negative and positive NAO phases, respectively. Upper pH tolerance limits for growth were also tested. In general, P. dalei grew at a higher rate in salinity 30 than 15 for all layers, but there were significant differences among strains. When accounting for inter-strain variability, cyst age had no effect on growth performance or upper pH tolerance limits for this species, indicating a stable growth response over the 100-year period in spite of environmental fluctuations. Our findings give some support for the use of morphospecies in environmental studies, particularly at decadal to century scales. Furthermore, the high intra-specific variability found down to sediment layers dated as ca. 50 years-old indicates

  2. Ultrasonic location system =

    Science.gov (United States)

    Albuquerque, Daniel Filipe

    Esta tese apresenta um sistema de localizacao baseado exclusivamente em ultrassons, nao necessitando de recorrer a qualquer outra tecnologia. Este sistema de localizacao foi concebido para poder operar em ambientes onde qualquer outra tecnologia nao pode ser utilizada ou o seu uso esta condicionado, como sao exemplo aplicacoes subaquaticas ou ambientes hospitalares. O sistema de localizacao proposto faz uso de uma rede de farois fixos permitindo que estacoes moveis se localizem. Devido a necessidade de transmissao de dados e medicao de distancias foi desenvolvido um pulso de ultrassons robusto a ecos que permite realizar ambas as tarefas com sucesso. O sistema de localizacao permite que as estacoes moveis se localizem escutando apenas a informacao em pulsos de ultrassons enviados pelos farois usando para tal um algoritmo baseado em diferencas de tempo de chegada. Desta forma a privacidade dos utilizadores e garantida e o sistema torna-se completamente independente do numero de utilizadores. Por forma a facilitar a implementacao da rede de farois apenas sera necessario determinar manualmente a posicao de alguns dos farois, designados por farois ancora. Estes irao permitir que os restantes farois, completamente autonomos, se possam localizar atraves de um algoritmo iterativo de localizacao baseado na minimizacao de uma funcao de custo. Para que este sistema possa funcionar como previsto sera necessario que os farois possam sincronizar os seus relogios e medir a distancia entre eles. Para tal, esta tese propoe um protocolo de sincronizacao de relogio que permite tambem obter as medidas de distancia entre os farois trocando somente tres mensagens de ultrassons. Adicionalmente, o sistema de localizacao permite que farois danificados possam ser substituidos sem comprometer a operabilidade da rede reduzindo a complexidade na manutencao. Para alem do mencionado, foi igualmente implementado um simulador de ultrassons para ambientes fechados, o qual provou ser bastante

  3. Regional influence of decadal to multidecadal Atlantic Oscillations during the last two millennia in Morocco, inferred from two high resolution δ18O speleothem records

    Science.gov (United States)

    Ait Brahim, Yassine; Sifeddine, Abdelfettah; Khodri, Myriam; Bouchaou, Lhoussaine; Cruz, Francisco W.; Pérez-Zanón, Núria; Wassenburg, Jasper A.; Cheng, Hai

    2017-04-01

    Climate projections predict substantial increase of extreme heats and drought occurrences during the coming decades in Morocco. It is however not clear what can be attributed to natural climate variability and to anthropogenic forcing, as hydroclimate variations observed in areas such as Morocco are highly influenced by the Atlantic climate modes. Since observational data sets are too short to resolve properly natural modes of variability acting on decadal to multidecadal timescales, high resolution paleoclimate reconstructions are the only alternative to reconstruct climate variability in the remote past. Herein, we present two high resolution and well dated speleothems oxygen isotope (δ18O) records sampled from Chaara and Ifoulki caves (located in Northeastern and Southwestern Morocco respectively) to investigate hydroclimate variations during the last 2000 years. Our results are supported by a monitoring network of δ18O in precipitation from 17 stations in Morocco. The new paleoclimate records are discussed in the light of existing continental and marine paleoclimate proxies in Morocco to identify significant correlations at various lead times with the main reconstructed oceanic and atmospheric variability modes and possible climate teleconnections that have potentially influenced the climate during the last two millennia in Morocco. The results reveal substantial decadal to multidecadal swings between dry and humid periods, consistent with regional paleorecords. Evidence of dry conditions exist during the Medieval Climate Anomaly (MCA) period and the Climate Warm Period (CWP) and humid conditions during the Little Ice Age (LIA) period. Statistical analyses suggest that the climate of southwestern Morocco remained under the combined influence of both the Atlantic Multidecadal Oscillation (AMO) and the North Atlantic Oscillation (NAO) over the last two millennia. Interestingly, the generally warmer MCA and colder LIA at longer multidecadal timescales probably

  4. Atomic layer deposition of metal oxide by non-aqueous sol-gel chemistry =

    Science.gov (United States)

    Marichy, Catherine

    O trabalho apresentado neste manuscrito foi desenvolvido no ambito do programa doutoral intitulado “Deposicao de Camadas Atomicas (ALD) de oxido de metais por sol-gel nao-aquoso”. O objectivo deste trabalho foi a preparacao de hetero-estruturas funcionais por ALD e a sua caracterizacao. Foi desenvolvido um novo processo de deposicao de oxido de estanho a temperatura baixa-moderada, utilizando um metodo ALD nao-aquoso, o qual foi aplicado com sucesso ao revestimento controlado das paredes internas e externas de nanotubos de carbono. Uma vez que a preparacao de nanomateriais funcionais requer uma elevada exatidao do processo de deposicao, foi demonstrada a deposicao precisa de filmes que se adaptem a forma do substrato ou de filmes nano-estruturados constituidos por particulas em varios substratos. Alem disso, foram depositados com grande exatidao varios oxidos de metal em nanotubos de carbono e demonstrou-se a possibilidade de ajustar o revestimento feito por ALD atraves do controlo da funcionalizacao da superficie do substrato nano-estruturado de carbono. As hetero-estruturas obtidas foram posteriormente aplicadas como sensores de gases. O melhoramento verificado na sensibilidade foi atribuido a formacao de heterojuncoes p-n entre o filme de oxido de metais e o suporte. O trabalho desenvolvido tendo como objetivo o controlo do revestimento por ALD atraves da funcionalizacao da superficie do suporte e certamente de interesse para o design de hetero-estruturas funcionais baseadas em substratos de carbono. De facto, durante o ultimo periodo do programa de doutoramento, este conceito foi alargado a funcionalizacao e revestimento com oxidos de metal de fibras de carbono preparadas por “electrospinning”, de forma a melhorar a estabilidade e a atividade eletrocatalitica de catalisadores a base de Pt. Este trabalho foi realizado maioritariamente na Universidade de Aveiro mas tambem na Universidade Nacional de Seul e beneficiou de varias colaboracoes internacionais

  5. The enhanced greenhouse signal versus natural variations in observed climate time series: a statistical approach

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwiese, C D [J.W. Goethe Univ., Frankfurt (Germany). Inst. for Meteorology and Geophysics

    1996-12-31

    It is a well-known fact that human activities lead to an atmospheric concentration increase of some IR-active trace gases (greenhouse gases GHG) and that this influence enhances the `greenhouse effect`. However, there are major quantitative and regional uncertainties in the related climate model projections and the observational data reflect the whole complex of both anthropogenic and natural forcing of the climate system. This contribution aims at the separation of the anthropogenic enhanced greenhouse signal in observed global surface air temperature data versus other forcing using statistical methods such as multiple (multiforced) regressions and neural networks. The competitive natural forcing considered are volcanic and solar activity, in addition the ENSO (El Nino/Southern Oscillation) mechanism. This analysis will be extended also to the NAO (North Atlantic Oscillation) and anthropogenic sulfate formation in the troposphere

  6. Patterns of variability of the superficial temperatures of the sea in the Colombian Caribbean coast

    International Nuclear Information System (INIS)

    Bernal, Gladys; Poveda, German; Roldan, Paola; Andrade, Carlos

    2006-01-01

    The space - time variability of sea surface temperature (SST) along the Colombian coastal Caribbean zone was analyzed with monthly time series spanning the period 1982- 2000. Analyses included the spatial variability associated with the annual cycle, and inter annual time scales associated with el Nino southern oscillation (ENSO), the North Atlantic Oscillation (NAO), as well as long-term trends. Analyses were included to study two tropical low-level atmospheric jets affecting the climatology of the northwestern corner of South America (the so-called Choco and San Andres low level jets). Two separate regions have been found along the Caribbean sea to exhibit quite different climatic behavior: the southwestern region with a warm pool directly related to panama Colombia gyre, and the northeastern region with a cold pool related to the Guajira upwelling system

  7. CLINICAL OBSERVATION ON TREATMENT OF 61 CASES OF INSOMNIA WITH AURICULAR PLASTER THERAPY

    Institute of Scientific and Technical Information of China (English)

    张家彤; 王月

    2003-01-01

    Objective: To observe the therapeutic effect of auricular plaster (otopoint-pressure) therapy in thetreatment of insomnia. Methods: In this paper, 61 cases of insomnia patients including 16 males and 45 females weretreated with Ershenmen (MA-TF 1), Zhen (MA-AT), Yuanzhong (MA-AT), Nao Dian and E (MA-AT), combined withother otopoints according to symptoms. The otopoint was stuck with a piece of plaster adhered with vaccaria seeds andpressured by the patient him- or her-self. The treatment was given twice a week, with 7 times being a therapeuticcourse. Results: After 1 - 2 courses of treatment, 19 (31.15%) cases were cured, 34 (55.74 % ) had improvementand 8 (13.11%) had no changes, with the total effective rate being 86.9%. Conclusion: Auricular plaster therapyworks well in the treatment of insomnia patient.

  8. The enhanced greenhouse signal versus natural variations in observed climate time series: a statistical approach

    Energy Technology Data Exchange (ETDEWEB)

    Schoenwiese, C.D. [J.W. Goethe Univ., Frankfurt (Germany). Inst. for Meteorology and Geophysics

    1995-12-31

    It is a well-known fact that human activities lead to an atmospheric concentration increase of some IR-active trace gases (greenhouse gases GHG) and that this influence enhances the `greenhouse effect`. However, there are major quantitative and regional uncertainties in the related climate model projections and the observational data reflect the whole complex of both anthropogenic and natural forcing of the climate system. This contribution aims at the separation of the anthropogenic enhanced greenhouse signal in observed global surface air temperature data versus other forcing using statistical methods such as multiple (multiforced) regressions and neural networks. The competitive natural forcing considered are volcanic and solar activity, in addition the ENSO (El Nino/Southern Oscillation) mechanism. This analysis will be extended also to the NAO (North Atlantic Oscillation) and anthropogenic sulfate formation in the troposphere

  9. Tensile strain effect in ferroelectric perovskite oxide thin films on spinel magnesium aluminum oxide substrate

    Science.gov (United States)

    Zhou, Xiaolan

    Ferroelectrics are used in FeRAM (Ferroelectric random-access memory). Currently (Pb,Zr)TiO3 is the most common ferroelectric material. To get lead-free and high performance ferroelectric material, we investigated perovskite ferroelectric oxides (Ba,Sr)TiO3 and BiFeO3 films with strain. Compressive strain has been investigated intensively, but the effects of tensile strain on the perovskite films have yet to be explored. We have deposited (Ba,Sr)TiO3, BiFeO3 and related films by pulsed laser deposition (PLD) and analyzed the films by X-ray diffractometry (XRD), atomic force microscopy (AFM), etc. To obtain inherently fully strained films, the selection of the appropriate substrates is crucial. MgAl2O4 matches best with good quality and size, yet the spinel structure has an intrinsic incompatibility to that of perovskite. We introduced a rock-salt structure material (Ni 1-xAlxO1+delta) as a buffer layer to mediate the structural mismatch for (Ba,Sr)TiO3 films. With buffer layer Ni1-xAlxO1+delta, we show that the BST films have high quality crystallization and are coherently epitaxial. AFM images show that the films have smoother surfaces when including the buffer layer, indicating an inherent compatibility between BST-NAO and NAO-MAO. In-plane Ferroelectricity measurement shows double hysteresis loops, indicating an antiferroelectric-like behavior: pinned ferroelectric domains with antiparallel alignments of polarization. The Curie temperatures of the coherent fully strained BST films are also measured. It is higher than 900°C, at least 800°C higher than that of bulk. The improved Curie temperature makes the use of BST as FeRAM feasible. We found that the special behaviors of ferroelectricity including hysteresis loop and Curie temperature are due to inherent fully tensile strain. This might be a clue of physics inside ferroelectric stain engineering. An out-of-plane ferroelectricity measurement would provide a full whole story of the tensile strain. However, a

  10. Biodiesel production through in situ transesterification of sunflower seeds by homogeneous and heterogeneous catalysis; Producao de biodiesel atraves de transesterificacao in situ de sementes de girassol via catalise homogenea e heterogenea

    Energy Technology Data Exchange (ETDEWEB)

    Fama, Paola Ervatti; San Gil, Rosane Aguiar da Silva; Lachter, Elizabeth Roditi, E-mail: lachter@iq.ufrj.b [Universidade Federal do Rio de Janeiro (IQ/UFRJ), RJ (Brazil). Inst. de Quimica

    2010-07-01

    The objective of this work is to show the results of the in situ transesterification of sunflower seed oil with methanol on basic homogeneous and heterogeneous catalysis for the production of biodiesel. In homogeneous catalysis, the activity of K{sub O}H and K{sub 2}CO{sub 3} were evaluated using the same oil:methanol ratio of 1:90. KOH showed to be more active than K2CO{sub 3}, leading to total conversion in biodiesel after 1h reaction time. In the heterogeneous catalysis the activity of K{sub 2}CO{sub 3}/Al{sub 2}O{sub 3} was comparable to the activity of K{sub 2}CO{sub 3} bulk: 53.0 and 66.6% resp. The properties of samples of biodiesel produced by homogeneous and heterogeneous catalysis were evaluated and are in accordance with the recommended fuel properties. (author)

  11. Observed and simulated impacts of the summer NAO in Europe: implications for projected drying in the Mediterranean region

    Energy Technology Data Exchange (ETDEWEB)

    Blade, Ileana; Fortuny, Didac [Universitat de Barcelona, Facultat de Fisica, Departament d' Astronomia i Meteorologia, Barcelona (Spain); Liebmann, Brant [CIRES Climate Diagnostics Center, NOAA/Earth System Research Laboratory, Boulder, CO (United States); Oldenborgh, Geert Jan van [Royal Dutch Meteorological Institute, De Bilt (Netherlands)

    2012-08-15

    Climate models predict substantial summer precipitation reductions in Europe and the Mediterranean region in the twenty-first century, but the extent to which these models correctly represent the mechanisms of summertime precipitation in this region is uncertain. Here an analysis is conducted to compare the observed and simulated impacts of the dominant large-scale driver of summer rainfall variability in Europe and the Mediterranean, the summer North Atlantic Oscillation (SNAO). The SNAO is defined as the leading mode of July-August sea level pressure variability in the North Atlantic sector. Although the SNAO is weaker and confined to northern latitudes compared to its winter counterpart, with a southern lobe located over the UK, it significantly affects precipitation in the Mediterranean, particularly Italy and the Balkans (correlations of up to 0.6). During high SNAO summers, when strong anticyclonic conditions and suppressed precipitation prevail over the UK, the Mediterranean region instead is anomalously wet. This enhanced precipitation is related to the presence of a strong upper-level trough over the Balkans - part of a hemispheric pattern of anomalies that develops in association with the SNAO - that leads to mid-level cooling and increased potential instability. Neither this downstream extension nor the surface influence of the SNAO is captured in the two CMIP3 models examined (HadCM3 and GFDL-CM2.1), with weak or non-existent correlations between the SNAO and Mediterranean precipitation. Because these models also predict a strong upward SNAO trend in the future, the error in their representation of the SNAO surface signature impacts the projected precipitation trends. In particular, the attendant increase in precipitation that, based on observations, should occur in the Mediterranean and offset some of the non-SNAO related drying does not occur. Furthermore, the fact that neither the observed SNAO nor summer precipitation in Europe/Mediterranean region exhibits any significant trend so far (for either the full century or the recent half of the record) does not increase our confidence in these model projections. (orig.)

  12. Inspection of non-piggable pipelines at PETROBRAS-UN Bahia; Inspecao de dutos nao-pigaveis na PETROBRAS-UN Bahia

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Luis F.C.; Lopes, Paulo R. [PETROBRAS, Salvador, BA (Brazil). Unidade de Negocios da Bahia

    2005-07-01

    PETROBRAS has made a huge effort to inspect and rehabilitate its pipeline net, mainly over the past 10 years. Currently, E and P inspection teams are being challenged to find feasible solutions for the inspection of non-piggable pipelines, so named because they have unsuitable geometry and/or operating conditions for usual in-line inspections. Inside this pipeline category, flow lines, injection and distribution lines and even non-metallic pipelines may be highlighted. This paper presents the results of tests and developments of new inspection tools for the inspection of non piggable pipelines, future tests to be performed in PETROBRAS/E and P Bahia (UN-BA) and some inspection cases in which the operating conditions hinder the run of smart pigs. (author)

  13. Avaliacao da espessura medio-intimal em pacientes com doenca renal cronica nao dialitica: estudo prospectivo de 24 meses

    Directory of Open Access Journals (Sweden)

    Andrea Gaspar Marcos

    2014-03-01

    Full Text Available Introdução: O aumento da espessura média-intimal (EMI avaliada por ultrassom é um preditor de risco cardiovascular na população geral. Porém, em pacientes com doença renal crônica nos estágios iniciais, essa associação ainda não está bem estabelecida. Objetivo: Avaliar a associação EMI com a ocorrência de eventos cardiovasculares e mortalidade em pacientes nos estágios iniciais da doença renal crônica. Métodos: A análise post hoc de uma coorte de pacientes nos estágios 2-4 da DRC. Foram avaliados dados laboratoriais, ultrassom da artéria carótida e tomografia coronariana no início do estudo e a ocorrência de óbito, em seguimento por 24 meses. Resultados: Um total de 117 pacientes (57 ± 11 anos, 61% sexo masculino foram avaliados. A taxa de filtração glomerular foi 36 ± 17 mL/min, 96% dos pacientes eram hipertensos, 23% diabéticos e 27% obesos. Calcificação arterial coronariana esteve presente em 48% dos pacientes, sendo mais prevalente em pacientes nos estágios mais avançados da DRC (p = 0,02. EMI foi 0,6 mm (0,4-0,7 mm. Comparado aos pacientes com EMI < 0,6mm, aqueles com EMI ≥ 0,6 mm eram mais velhos (p = 0,001, apresentavam maior prevalência do sexo masculino (p = 0,001, menor taxa de filtração glomerular (p = 0,01 e maior proporção de pacientes com calcificação (p = 0,001. Não foi observada relação entre a espessura média-intimal e a ocorrência de evento cardiovascular e óbito. Conclusão: A espessura médio-intimal em pacientes DRC se associou à calcificação coronariana, mas não à ocorrência de eventos cardiovasculares e óbito, em um seguimento de 24 meses.

  14. Energy recycling: an innovative solution for unrecyclable plastic; Reciclagem energetica: uma solucao inovadora para o plastico nao reciclavel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Julyane Carolina; Oliveira, Magno Andre de; Pires, Pedro Henrique; Silva, Thuanye Peixoto; Rodrigues, Marcia [Centro Universitario de Belo Horizonte (UnBH), MG (Brazil)], e-mails: juhlorah@hotmail.com, marromar2004@yahoo.com.br

    2011-07-01

    This paper shows a new technology that is already used in over 35 countries with more than 750 plants in total and is still under study in Brazil: the energy recycling of plastic. Through studies, tables, comparisons and observations, have to analyze the plastic, chemical composition, the steps of material recycling and energy production, the final products obtained by recycling and gases released during the process. Thus, after highlighting how this technology is advantageous, it is expected to awaken to the reflection that it is feasible to use the recycling energy due to its great benefits environmental, social and economic shown the course of research. (author)

  15. Synthesis and electrochemical characterization of highly tolerant Pd electrocatalysts as cathodes in direct ethylene glycol fuel cells (DEGFC)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Varela, F.J.; Fraire Luna, S. [Cinvestav, Unidad Saltillo, Ramos Arizpe, Coahuila (Mexico)] e-mail: javier.varela@cinvestav.edu.mx; Savadogo, O. [Laboratoire d' Electrochimie et de Materiaux Energetiques, Ecole Polytechnique de Montreal, Montreal, QC (Canada)

    2009-09-15

    Highly selective Pd electrocatalysts were synthesized by the formic acid method and evaluated as cathodes for DEGFC applications. In rotating disc measurements in acid medium, the Pd/C cathode showed important catalytic activity for the Oxygen Reduction Reaction (ORR). In the presence of ethylene glycol (EG, C{sub 2}H{sub 6}O{sub 2}), Pd/C exhibited an excellent electrochemical behavior and full tolerance to the organic molecule. No current density peaks associated to the EG oxidation reaction emerged and the shift in onset potential for the ORR (Eonset) toward more negative potentials was negligible on this cathode. Moreover, the evaluation of Pd/C in a DEGFC operating at 80 degrees Celsius demonstrated its high performance as cathode. As a comparison, commercial Pt/C was tested under the same conditions showing a limited selectivity for the ORR. The detrimental effect of EG on the Pt electrocatalysts resulted in high intensity current density peaks due to the oxidation of EG and a significant shift in Eonset. Given these results, it is expected that highly efficient Pd-based cathodes can find application in DEGFCs. [Spanish] Se sintetizaron electrocatalizadores altamente selectivos mediante el metodo de acido formico y se evaluaron como catodos en aplicaciones de CCGED. En mediciones de disco rotatorio en medio acido, el catodo Pd/C mostro importante actividad catalitica en la reaccion de reduccion de oxigeno (RRO). En la presencia de glicol de etileno (GE, C{sub 2}H{sub 6}O{sub 2}), Pd/C exhibio un excelente comportamiento electromecanico y tolerancia total a la molecula organica. No surgieron picos de densidad de corriente asociados con la reaccion de oxidacion de GE y el corrimiento en el potencial de inicio para la RRO (Einicio) hacia potenciales mas negativos fue despreciable en este catodo. Como comparacion, se probo un Pt/C bajo las mismas condiciones y se observo una selectividad limitada para el RRO. El efecto perjudicial de GE en el electrocatalizador

  16. PROMET - The Journal of Meteorological Education issued by DWD

    Science.gov (United States)

    Rapp, J.

    2009-09-01

    Promet is published by the German Meteorological Service (DWD) since 1971 to improve meteorologists and weather forecasters skills. The journal comprises mainly contributions to topics like biometeorology, the NAO, or meteorology and insurance business. The science-based articles should illustrate the special issue in an understandable and transparent way. In addition, the journal contains portraits of other national meteorological services and university departments, book reviews, list of university degrees, and other individual papers. Promet is published only in German language, but included English titles and abstracts. The journal is peer-reviewed by renowned external scientists. It is distributed free of charge by DWD to the own meteorological staff. On the other hand, DMG (the German Meteorological Society) hand it out to all members of the society. The current issues deal with "Modern procedures of weather forecasting in DWD” and "E-Learning in Meteorology”.

  17. Climate Change and Human Occupation in Denmark and Syria

    DEFF Research Database (Denmark)

    Schrøder, Niels; Jensen, Gitte; Limborg, Magnus

    2007-01-01

    the main changes in human activities in the areas. It also confirms that the climatic histories of the sites are closely correlated - with strong ties to global causes of climate change. The NAO (North Atlantic Oscillation) caused contrasting rainfall conditions in Denmark and Levant. Over a period of one......Classical sites for studies of human occupation and climatic changes in Denmark and Syria - have been re-examined. A detailed geological/geophysical mapping of selected sites and geochemical /palynological analysis of cores/profiles confirms that climate change has been the decisive factor behind....... The changes in human occupation in Syria and in Denmark both seems to correlate with the proxies of climate change esp. the change from Atlantic to Subboreal around 4000BC, the change from Subboreal to Subatlantic around 500 BC are marked in as well the climate record and archaeological records (monsoon...

  18. Climate variability from isotope records in precipitation

    International Nuclear Information System (INIS)

    Grassl, H.; Latif, M.; Schotterer, U.; Gourcy, L.

    2002-01-01

    Selected time series from the Global Network for Isotopes in Precipitation (GNIP) revealed a close relationship to climate variability phenomena like El Nino - Southern Oscillation (ENSO) or the North Atlantic Oscillation (NAO) although the precipitation anomaly in the case studies of Manaus (Brazil) and Groningen (The Netherlands) is rather weak. For a sound understanding of this relationship especially in the case of Manaus, the data should include major events like the 1997/98 El Nino, however, the time series are interrupted frequently or important stations are even closed. Improvements are only possible if existing key stations and new ones (placed at 'hot spots' derived from model experiments) are supported continuously. A close link of GNIP to important scientific programmes like CLIVAR, the Climate Variability and Predictability Programme seems to be indispensable for a successful continuation. (author)

  19. Mixed-Alkali Effect in Li2O-Na2O-K2O-B2O3 Glasses: Infrared and Optical Absorption Studies

    Science.gov (United States)

    Samee, M. A.; Edukondalu, A.; Ahmmad, Shaik Kareem; Taqiullah, Sair Md.; Rahman, Syed

    2013-08-01

    The mixed-alkali effect (MAE) has been investigated in the glass system (40 - x)Li2O- xNa2O-10K2O-50B2O3 (0 mol% ≤ x ≤ 40 mol%) through density, modulated differential scanning calorimetry (DSC), and optical absorption studies. From the absorption studies, the values of the optical band gap ( E opt) for direct transition and Urbach energy (Δ E) have been evaluated. The values of E opt and Δ E show nonlinear behavior with the compositional parameter. The density and glass-transition temperature of the present glasses also show nonlinear variation, supporting the existence of MAE. The infrared (IR) spectra of the glasses reveal the presence of three- and four-coordinated boron atoms. The specific vibrations of Li-O, Na-O, and K-O bonds were observed in the present IR study.

  20. La iglesia de San Jorge en Shipcka (Albania**

    Directory of Open Access Journals (Sweden)

    Kliti Kallamata

    2012-12-01

    Full Text Available El artículo narra la restauración de una pequeña iglesia albanesa condenada al abandono y al olvido a causa de la desidia y la emigración rural. El texto aborda previamente la historia y la tipología de la basílica para describir posteriormente el penoso estado de conservación del conjunto, con graves problemas de estabilidad estructural y zonas completamente arruinadas. La intervención acometió la consolidación estructural, la reconstrucción tipológica de las partes arruinadas, la restauración de las pinturas murales y la recuperación del iconostasio, los iconos y elementos de madera del naos, además de la capilla adyacente, el entorno de la iglesia con su granero histórico y sus muros de cerca.

  1. Effects of the North Atlantic Oscillation and wind waves on salt marsh dynamics in the Danish Wadden Sea

    DEFF Research Database (Denmark)

    Kim, Daehyun; Grant, William E.; Cairns, David M.

    2013-01-01

    Long-term eustatic sea-level variation has been recognized as a primary factor affecting the hydrological and geomorphic dynamics of salt marshes. However, recent studies suggest that wind waves influenced by atmospheric oscillations also may play an important role in many coastal areas. Although...... this notion has been conceptually introduced for the Wadden Sea, no modeling attempts have been made yet. As a proof of concept, this study developed a simulation model using the commercially available STELLAA (R) software, based on long-term data on water level and sedimentation collected at a back......-barrier marsh on the Skallingen peninsula in Denmark. In the model, the frequency (number year(-1)) of wind-driven extreme high water level (HWL) events (> 130 cm Danish Ordnance Zero) was simulated in terms of the North Atlantic Oscillation (NAO) index. Then, surface accretion (cm year(-1)) and submergence...

  2. Novel materials based on chitosan, its derivatives and cellulose fibres

    Science.gov (United States)

    Fernandes, Susana Cristina de Matos

    O presente trabalho tem como principal objectivo o desenvolvimento de novos materiais baseados em quitosano, seus derivados e celulose, na forma de nanofibras ou de papel. Em primeiro lugar procedeu-se a purificacao das amostras comerciais de quitosano e a sua caracterizacao exaustiva em termos morfologicos e fisicoquimicos. Devido a valores contraditorios encontrados na literatura relativamente a energia de superficie do quitosano, e tendo em conta a sua utilizacao como precursor de modificacoes quimicas e a sua aplicacao em misturas com outros materiais, realizou-se tambem um estudo sistematico da determinacao da energia de superficie do quitosano, da quitina e seus respectivos homologos monomericos, por medicao de ângulos de contacto Em todas as amostras comerciais destes polimeros identificaram-se impurezas nao polares que estao associadas a erros na determinacao da componente polar da energia de superficie. Apos a remocao destas impurezas, o valor da energia total de superficie (gs), e em particular da sua componente polar, aumentou consideravelmente. Depois de purificadas e caracterizadas, algumas das amostras de quitosano foram entao usadas na preparacao de filmes nanocompositos, nomeadamente dois quitosanos com diferentes graus de polimerizacao, correspondentes derivados soluveis em agua (cloreto de N-(3-(N,N,N-trimetilamonio)-2- hidroxipropilo) de quitosano) e nanofibras de celulose como reforco (celulose nanofibrilada (NFC) e celulose bacteriana (BC). Estes filmes transparentes foram preparados atraves de um processo simples e com conotacao 'verde' pela dispersao homogenea de diferentes teores de NFC (ate 60%) e BC (ate 40%) nas solucoes de quitosano (1.5% w/v) seguida da evaporacao do solvente. Os filmes obtidos foram depois caracterizados por diversas tecnicas, tais como SEM, AFM, difraccao de raio-X, TGA, DMA, ensaios de traccao e espectroscopia no visivel. Estes filmes sao altamente transparentes e apresentam melhores propriedades mecânicas e maior

  3. Effects of Incorporated Radioactivity and External Radiation on Heterogeneous Catalysis; Effets de la radioactivite incorporee et des rayonnements externes sur la catalyse heterogene; Vliyanie vvedennoj radioaktivnosti i vneshnego oblucheniya na geterogennyj kataliz; Efectos de la radiactividad incorporada y de la irradiacion externa sobre la catalisis heterogenea

    Energy Technology Data Exchange (ETDEWEB)

    Krohn, N. A.; Wymer, R. G. [Oak Ridge National Laboratory, Oak Ridge and University of Tennessee, Knoxville, Tennessee (United States)

    1963-11-15

    oxido de cromo-alumina activados, en sistemas de circulacion. Examinan tambien los efectos de la incorporacion de radioisotopos en los catalizadores y de su preirradiacion con los rayos gamma emitidos por una fuente de cobalto-60. Los catalizadores de sulfato magnesico y de sulfato magnesico-sulfato sodico, con un contenido de hasta 45, 5 mc de {sup 35}S, se revelaron menos activos por unidad de superficie que los catalizadores no radiactivos de composicion analoga. La merma de actividad catalitica subsistio incluso despues de haber disminuido considerablemente la radiactividad. Ademas, no se observo cambio alguno en l a actividad catalitica despues de una exposicion a rayos X en el curso de la reaccion. Estos resultados sugieren a los autores que la emision de particulas beta por el catalizador durante su empleo no ejerce ningun efecto. Las informaciones relativas a un incremento de esa actividad catalitica podrian atribuirse al hecho de que, para un conjunto dado de condiciones de preparacion, los catalizadores radiactivos ofrecen una superficie mayor que sus equivalentes no radiactivos, circunstancia esta que no fue tenida en cuenta. La preirradiacion con los rayos gamma del cobalto-60 en dosis de hasta 10{sup 11} erg/g no influyo en absoluto sobre la actividad de los catalizadores. Por el contrario, la preirradiacion gamma del cobalto-60 de catalizadores de oxido de cromo-alumina con dosis de 4,2 x 10{sup 11} erg/g incremento esa actividad en un 34% aproximadamente a 485{sup o}C, pero la incorporacion de hasta 148 me de {sup 147}Pm por gramo de catalizador tuvo escaso o ningun efecto. En este caso, las radiaciones no ejercieron un efecto notable sobre el area superficial o sobre la energia de attivacion aparente. (author) [Russian] Na tsirkulyatsionno-staticheskoj ustanovke issledovany parofaehnaya degidratatsiya tsiklogeksanola s primeneniem sul'fatmagnievogo i sul'fatmagnievogo - sul'fatnatrivogo katalizatorov i degidrogenizatsiya metiltsiklogeksana v toluol na

  4. Characterization of the Temporal Clustering of Flood Events across the Central United States in terms of Climate States

    Science.gov (United States)

    Mallakpour, Iman; Villarini, Gabriele; Jones, Michael; Smith, James

    2016-04-01

    The central United States is a region of the country that has been plagued by frequent catastrophic flooding (e.g., flood events of 1993, 2008, 2013, and 2014), with large economic and social repercussions (e.g., fatalities, agricultural losses, flood losses, water quality issues). The goal of this study is to examine whether it is possible to describe the occurrence of flood events at the sub-seasonal scale in terms of variations in the climate system. Daily streamflow time series from 774 USGS stream gage stations over the central United States (defined here to include North Dakota, South Dakota, Nebraska, Kansas, Missouri, Iowa, Minnesota, Wisconsin, Illinois, West Virginia, Kentucky, Ohio, Indiana, and Michigan) with a record of at least 50 years and ending no earlier than 2011 are used for this study. We use a peak-over-threshold (POT) approach to identify flood peaks so that we have, on average two events per year. We model the occurrence/non-occurrence of a flood event over time using regression models based on Cox processes. Cox processes are widely used in biostatistics and can be viewed as a generalization of Poisson processes. Rather than assuming that flood events occur independently of the occurrence of previous events (as in Poisson processes), Cox processes allow us to account for the potential presence of temporal clustering, which manifests itself in an alternation of quiet and active periods. Here we model the occurrence/non-occurrence of flood events using two climate indices as climate time-varying covariates: the North Atlantic Oscillation (NAO) and the Pacific-North American pattern (PNA). The results of this study show that NAO and/or PNA can explain the temporal clustering in flood occurrences in over 90% of the stream gage stations we considered. Analyses of the sensitivity of the results to different average numbers of flood events per year (from one to five) are also performed and lead to the same conclusions. The findings of this work

  5. Tendencies of extreme values on rainfall and temperature and its relationship with teleconnection patterns

    Science.gov (United States)

    Taboada, J. J.; Cabrejo, A.; Guarin, D.; Ramos, A. M.

    2009-04-01

    It is now very well established that yearly averaged temperatures are increasing due to anthropogenic climate change. In the area of Galicia (NW Spain) this trend has also been determined. Rainfall does not show a clear tendency in its yearly accumulated values. The aim of this work is to study different extreme indices of rainfall and temperatures analysing variability and possible trends associated to climate change. Station data for the study was provided by the CLIMA database of the regional government of Galicia (NW Spain). The definition of the extreme indices was taken from the joint CCl/CLIVAR/JCOMM Expert Team (ET) on Climate Change Detection and Indices (ETCCDI) This group has defined a set of standard extreme values to simplify intercomparison of data from different regions of the world. For the temperatures in the period 1960-2006, results show a significant increase of the number of days with maximum temperatures above the 90th percentile. Furthermore, a significant decrease of the days with maximum temperatures below the 10th percentile has been found. The tendencies of minimum temperatures are reverse: fewer nights with minimum temperatures below 10th percentile, and more with minimum temperatures above 90th percentile. Those tendencies can be observed all over the year, but are more pronounced in summer. This trend is expected to continue in the next decades because of anthropogenic climate change. We have also calculated the relationship between the above mentioned extreme values and different teleconnection patterns appearing in the North Atlantic area. Results show that local tendencies are associated with trends of EA (Eastern Atlantic) and SCA (Scandinavian) patterns. NAO (North Atlantic Oscillation) has also some relationship with these tendencies, but only related with cold days and nights in winter. Rainfall index do not show any clear tendency on the annual scale. Nevertheless, the count of days when precipitation is greater than 20mm (R20

  6. Long term precipitation trends and variability within the Mediterranean region

    Directory of Open Access Journals (Sweden)

    C. M. Philandras

    2011-12-01

    Full Text Available In this study, the trends and variability of annual precipitation totals and annual rain days over land within the Mediterranean region are analyzed. Long term ground-based observations concerning, on one hand, monthly precipitation totals (1900–2010 and rain days (1965–2010 from 40 meteorological stations within the Mediterranean region were obtained from the Hellenic National Meteorological Service and the World Climate Data and Monitoring Programme (WCDMP of the World Meteorological Organization. On the other hand, high spatial resolution (0.5° × 0.5° gridded monthly data CRU TS 3.1 were acquired from the Climatic Research Unit, University of East Anglia, for the period 1901–2009. The two datasets were compared by means of trends and variability, while the influence of the North Atlantic Oscillation (NAO in the Mediterranean precipitation was examined. In the process, the climatic changes in the precipitation regime between the period 1961–1990 (reference period and the period 2071–2100 (future climate were presented using climate model simulations (RACMO2.1/KNMI. The future climate projections were based on SRES A1B.

    The findings of the analysis showed that statistically significant (95% confidence level negative trends of the annual precipitation totals exist in the majority of Mediterranean regions during the period 1901–2009, with an exception of northern Africa, southern Italy and western Iberian peninsula, where slight positive trends (not statistically significant at 95% CL appear. Concerning the annual number of rain days, a pronounced decrease of 20 %, statistically significant (95% confidence level, appears in representative meteorological stations of east Mediterranean, while the trends are insignificant for west and central Mediterranean. Additionally, NAO index was found to be anticorrelated with the precipitation totals and the number of rain days mainly in Spain, southern France, Italy and Greece. These

  7. Northern tropical Atlantic climate since late Medieval times from Northern Caribbean coral geochemistry

    Science.gov (United States)

    Kilbourne, K. H.; Xu, Y.

    2015-12-01

    Paleoclimate reconstructions of different global climate modes over the last 1000 years provide the basis for testing the relative roles of forced and unforced variability climate system, which can help us improve projections of future climate change. The Medieval Climate Anomaly (MCA) has been characterized by a combination of persistent La Niña-like conditions, a positive North Atlantic Oscillation (+NAO), and increased Atlantic Meridional Overturning Circulation (AMOC). The northern tropical Atlantic is sensitive to each of these climate patterns, but not all of them have the same regional fingerprint in the modern northern tropical Atlantic. The relative influence of different processes related to these climate patterns can help us better understand regional responses to climate change. The regional response of the northern tropical Atlantic is important because the tropical Atlantic Ocean is a large source of heat and moisture to the global climate system that can feedback onto global climate patterns. This study presents new coral Sr/Ca and δ18O data from the northern tropical Atlantic (Anegada, British Virgin Islands). Comparison of the sub-fossil corals that grew during the 13th and 14th Centuries with modern coral geochemical data from this site indicates relatively cooler mean conditions with a decrease in the oxygen isotopic composition of the water consistent with lower salinities. Similar average annual cycles between modern and sub-fossil Sr/Ca indicate no change in seasonal temperature range, but a difference in the relative phasing of the δ18O seasonal cycles indicates that the fresher mean conditions may be due to a more northerly position of the regional salinity front. This localized response is consistent with some, but not all of the expected regional responses to a La Niña-like state, a +NAO state, and increased AMOC. Understanding these differences can provide insight into the relative importance of advection versus surface fluxes for

  8. Teor e composição química do óleo essencial de Hyptis marrubioides Epl., Lamiaceae em função da sazonalidade = Content and chemical composition of Hyptis marrubioides essential oil in function of seasons

    Directory of Open Access Journals (Sweden)

    Suzan Kelly Vilela Bertolucci

    2010-07-01

    Full Text Available Os oleos essenciais sao principios odoriferos armazenados em celulas especiais da planta. O oleo essencial no genero Hyptis e usado como anestesico, antiespasmodico, antiinflamatorio e pode induzir aborto em doses elevadas. O objetivo deste trabalho foi avaliar a influencia da sazonalidade no teor e composicao do oleo essencial de Hyptis marrubioides. O delineamento experimental foi inteiramente casualizado, com quatro tratamentos (inverno, primavera, verao e outono e seis repeticoes, totalizando 60 plantas. O oleo essencial foi extraido por hidrodestilacao, em aparelho de Clevenger. A analise qualitativa do oleo essencial foi por cromatografia em fase gasosa (CG/EM. Na estacao do verao, as folhas das plantas de H. marrubiodes apresentaram os maiores teores de oleo essencial. Nas demais estacoes, os teores de oleo essencial obtidos foram semelhantes entre si. Os componentes majoritarios no oleo essencial foram os monoterpenoides α-tujona e β-tujona. As concentracoes relativas dos picos correspondentes a β-tujona nao apresentaram diferencas consideraveis nas quatro estacoes. Os sesquiterpenoides oxigenados (cedrol e cariofilenol e nao-oxigenados (α-copaeno, β-cariofileno, germacreno D e cadaleno foram encontrados em menores quantidades no oleo essencial, entretanto observam-se diferencas quantitativas ao longo das estacoes.Essential oils are odorous principles stored in special plant cells. The essential oil in the Hyptis genus is traditionally used as an anesthetic, antispasmodic, antiinflammatory, and can induce abortion in high doses. The purpose of this work was to evaluate the influence of seasons in essential oil content and chemical composition of species H. marrubioides. A completely randomized complete design was used with four treatments (winter, spring, summer and autumn and six replications, totaling 60 plants. The essential oil was obtained by hydrodistillation with a Clevenger apparatus. The qualitative analysis of the

  9. Interannual Variation in Phytoplankton Primary Production at a Global Scale

    Science.gov (United States)

    Rousseaux, Cecile Severine; Gregg, Watson W.

    2013-01-01

    We used the NASA Ocean Biogeochemical Model (NOBM) combined with remote sensing data via assimilation to evaluate the contribution of four phytoplankton groups to the total primary production. First, we assessed the contribution of each phytoplankton groups to the total primary production at a global scale for the period 1998-2011. Globally, diatoms contributed the most to the total phytoplankton production ((is)approximately 50%, the equivalent of 20 PgC·y1). Coccolithophores and chlorophytes each contributed approximately 20% ((is) approximately 7 PgC·y1) of the total primary production and cyanobacteria represented about 10% ((is) approximately 4 PgC·y1) of the total primary production. Primary production by diatoms was highest in the high latitudes ((is) greater than 40 deg) and in major upwelling systems (Equatorial Pacific and Benguela system). We then assessed interannual variability of this group-specific primary production over the period 1998-2011. Globally the annual relative contribution of each phytoplankton groups to the total primary production varied by maximum 4% (1-2 PgC·y1). We assessed the effects of climate variability on group-specific primary production using global (i.e., Multivariate El Niño Index, MEI) and "regional" climate indices (e.g., Southern Annular Mode (SAM), Pacific Decadal Oscillation (PDO) and North Atlantic Oscillation (NAO)). Most interannual variability occurred in the Equatorial Pacific and was associated with climate variability as indicated by significant correlation (p (is) less than 0.05) between the MEI and the group-specific primary production from all groups except coccolithophores. In the Atlantic, climate variability as indicated by NAO was significantly correlated to the primary production of 2 out of the 4 groups in the North Central Atlantic (diatoms/cyanobacteria) and in the North Atlantic (chlorophytes and coccolithophores). We found that climate variability as indicated by SAM had only a limited effect

  10. Influência da embalagem e estocagem no conteúdo de betacaroteno e ácido ascórbico em suco de manga “Ubá” industrializado = Influence of package and storage on the content of beta-carotene and ascorbic acid in industrialized “Ubá” mango juice

    Directory of Open Access Journals (Sweden)

    Daniela da Silva Oliveira

    2010-07-01

    Full Text Available Este trabalho investigou o conteudo e avaliou a estabilidade de doisantioxidantes naturais - β-caroteno e acido ascorbico (AA - em suco de manga "Uba" industrializado e armazenado em diferentes tempos de estocagem e correlacionou as recomendacoes de vitaminas A e C com o teor encontrado nos sucos. O β-caroteno e o AA foram analisados nos sucos comercializados em embalagem tetra pak, em cinco tempos de estocagem (1 a 5 meses e em embalagem de vidro, em tres tempos de estocagem (apos 3, 4 e 5 meses de armazenamento. A analise foi realizada por Cromatografia Liquida de Alta Eficiencia (CLAE. Nao foram detectadas diferencas estatisticamente significativas (α = 5% entre os diferentes tempos de estocagem, para ambos os componentes analisados, tanto em embalagens tetra pak quanto em embalagens de vidro. Alem disso, nao foram observadas diferencas significativas entre o conteudo de β-caroteno dos sucos comercializados nas duas embalagens. No entanto, houve diferenca significativa no teor de AA entre as diferentes embalagens, e a embalagem de vidro apresentou maior teor em relacao a embalagem tetrapak. Assim, as perdas ocasionadas especialmente pela permeabilidade da embalagem ao oxigenio deveriam ser alvo de atencao das industrias de alimentos.This work investigated the content and stability of two natural antioxidants . β-carotene and ascorbic acid (AA - in mango juice industrialized and stored during different storage times, correlating the recommendations of vitamins A and C with the content found in the juice. β-carotene and AA were analyzed in juice sold in tetra pak packaging, during five storage times (1 to 5months and in glass containers, during three storage times (after 3, 4 and 5 months of storage. The analysis was carried out using High Performance Liquid Chromatography (HPLC. No statically differences (α = 5 % were found between the different times of storage for both compounds analyzed, both in tetra pak package and glass container

  11. Mid- to late Holocene climate-driven regime shifts inferred from diatom, ostracod and stable isotope records from Lake Son Kol (Central Tian Shan, Kyrgyzstan)

    Science.gov (United States)

    Schwarz, Anja; Turner, Falko; Lauterbach, Stefan; Plessen, Birgit; Krahn, Kim J.; Glodniok, Sven; Mischke, Steffen; Stebich, Martina; Witt, Roman; Mingram, Jens; Schwalb, Antje

    2017-12-01

    Arid Central Asia represents a key region for understanding climate variability and interactions in the Northern Hemisphere. Patterns and mechanisms of Holocene climate change in arid Central Asia are, however, only partially understood. Multi-proxy data combining diatom, ostracod, sedimentological, geochemical and stable isotope analyses from a ca. 6000-year-old lake sediment core from Son Kol (Central Kyrgyzstan) show distinct and repeated changes in species assemblages. Diatom- and ostracod-inferred conductivity shifts between meso-euhaline and freshwater conditions suggest water balance and regime shifts. Organism-derived data are corroborated by stable isotope, mineralogical and geochemical records, underlining that Son Kol was affected by strong lake level fluctuations of several meters. The δ13Ccarb/δ18Ocarb correlation shows repeated switchovers from a closed to an open lake system. From 6000 to 3800 and 3250 to 1950 cal. yr BP, Son Kol was a closed basin lake with higher conductivities, increased nutrient availability and a water level located below the modern outflow. Son Kol became again a hydrologically open lake at 3800 and 1950 cal. yr BP. Comparisons to other local and regional paleoclimate records indicate that these regime shifts were largely controlled by changing intensity and position of the Westerlies and the Siberian Anticyclone that triggered changes in the amount of winter precipitation. A strong influence of the Westerlies ca. 5000-4400, 3800-3250 and since 1950 cal. yr BP enhanced the amount of precipitation during spring, autumn and winter, whereas cold and dry winters prevailed during phases with a strong Siberian Anticyclone and southward shifted Westerlies at ca. 6000-5000, 4400-3800 and 3250-1950 cal. yr BP. Similarities between variations in winter precipitation at Son Kol and records of the predominant NAO-mode further suggest a teleconnection between wet (dry) winter climate in Central Asia and a positive (negative) NAO

  12. Experiences of a Motivational Interview Delivered by a Robot: Qualitative Study

    Science.gov (United States)

    Galvão Gomes da Silva, Joana; Kavanagh, David J; Belpaeme, Tony; Taylor, Lloyd; Beeson, Konna

    2018-01-01

    Background Motivational interviewing is an effective intervention for supporting behavior change but traditionally depends on face-to-face dialogue with a human counselor. This study addressed a key challenge for the goal of developing social robotic motivational interviewers: creating an interview protocol, within the constraints of current artificial intelligence, which participants will find engaging and helpful. Objective The aim of this study was to explore participants’ qualitative experiences of a motivational interview delivered by a social robot, including their evaluation of usability of the robot during the interaction and its impact on their motivation. Methods NAO robots are humanoid, child-sized social robots. We programmed a NAO robot with Choregraphe software to deliver a scripted motivational interview focused on increasing physical activity. The interview was designed to be comprehensible even without an empathetic response from the robot. Robot breathing and face-tracking functions were used to give an impression of attentiveness. A total of 20 participants took part in the robot-delivered motivational interview and evaluated it after 1 week by responding to a series of written open-ended questions. Each participant was left alone to speak aloud with the robot, advancing through a series of questions by tapping the robot’s head sensor. Evaluations were content-analyzed utilizing Boyatzis’ steps: (1) sampling and design, (2) developing themes and codes, and (3) validating and applying the codes. Results Themes focused on interaction with the robot, motivation, change in physical activity, and overall evaluation of the intervention. Participants found the instructions clear and the navigation easy to use. Most enjoyed the interaction but also found it was restricted by the lack of individualized response from the robot. Many positively appraised the nonjudgmental aspect of the interview and how it gave space to articulate their motivation for

  13. Meteorological effects on Hg wet deposition in a forested site in the Adirondack region of New York during 2000-2015

    Science.gov (United States)

    Mao, Huiting; Ye, Zhuyun; Driscoll, Charles

    2017-11-01

    An analysis of weekly measurement data of mercury (Hg) wet deposition was conducted for Huntington Wildlife Forest (HWF), a forest ecosystem in Upstate New York and a biological Hg hotspot, during 2000-2015. Annual accumulated Hg wet deposition flux was found to decrease at a rate of -0.13 μg m-2 yr-1 (2% yr-1) (p = 0.09), and volume weighted mean (VWM) Hg precipitation concentrations at -0.14 ng L-1 yr-1 (2.5% yr-1) (p = 0.00). In examining data by season, no trends were identified for the two variables. It was found that the North Atlantic Oscillation (NAO) affected Hg wet deposition predominantly in spring, as did the position of the U.S. East Coast trough in summer, which suggests different dominant mechanisms driving Hg wet deposition in different seasons. The impacts of such large scale circulation processes were facilitated via variations in precipitation amounts. This was manifested in spring 2011 with the strongest positive phase of NAO, resulting in the wettest spring with the largest Hg wet deposition flux, and in summer 2007 with the U.S. East Coast trough positioned the farthest out over the Atlantic Ocean, causing the driest summer with the lowest Hg wet deposition flux of the study period. Extreme precipitation amounts in spring could singularly drive the overall long-term trend in Hg wet deposition whereas in summer other factors could just be as important. Similar mechanisms were thought to control the long term variations of Hg wet deposition and precipitation concentrations in all seasons but summer as indicated in their significant correlation in all but summer. Atmospheric concentrations of gaseous oxidized mercury (GOM) and particulate borne mercury (PBM) at HWF over 2009-2015 hardly exhibited correlations with Hg wet deposition or precipitation concentrations. Chemical transport model simulations strongly supported efficient scavenging of oxidized Hg by precipitation resulting in the lowest concentration of GOM in the warm season despite the

  14. Extratropical response to Fast and Slow episodes of Madden-Julian Oscillation in observation and using intervention experiments with CFSv2

    Science.gov (United States)

    Yadav, P.; Straus, D. M.

    2017-12-01

    The Madden-Julian Oscillation (MJO) is a potential source of predictability in the extratropics in extended range weather forecasting. The nature of MJO is sporadic and therefore, the mid-latitude response may depend on the nature of the MJO event, in particular the phase speed. We discuss the results of our observational and modeling study of mid-latitude circulation response to Fast and Slow MJO episodes using wintertime ERA-Interim reanalysis data and the CFSv2 coupled model of NOAA. The observational study shows that the mid-latitude response to different propagating speeds is not the same. The propagation speed is defined by the time the OLR takes to propagate from phase 3 to phase 6. The mid-latitude response is assessed in terms of composite maps and frequency of occurrence of robust circulation regimes. Fast episode composite anomalies of 500hPa height show a developing Rossby wave in the mid-Pacific with downstream propagation through MJO phases 2- 4. Development of NAO+ teleconnection pattern is stronger in Slow that in Fast MJO episodes, and occurs with a greater time lag after MJO heating is in the Indian Ocean (phase 3). Previous results find an increase in occurrence of NAO- regime following phase 6. We have found that much of this behavior is due to the slow episodes. Based on these observational results, intervention experiments using CFSv2 are designed to better understand the impact of heating/cooling and to estimate mid-latitude response to Fast and Slow MJO episodes. The added heating experiments consist of 31 year reforecasts for December 1 initial conditions from CFS reanalysis (1980-2011) in which the identical MJO evolution of three-dimensional diabatic heating has been added, thus producing fast and slow MJO episodes with well-defined phase speeds. We will discuss the results of these experiments with a focus on understanding the role of phase speed and interference in setting up the response, and to understand the mechanisms that

  15. Unconventional cells of TiO2 doped with erbium; Celulas nao convencionais de TiO2 dopado com erbio

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, P.C.; Campos, R.D.; Oliveira, A.S.; Wellen, R., E-mail: pollyana@cear.ufpb.edu.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Diniz, V.C.S.; Costa, A.C.F.M. da [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Departamento de Engenharia de Materiais

    2016-07-01

    The technology used in TiO{sub 2} solar cells is in constant improvement, new configurations have been developed, aiming practicality and leading to efficiency increase of photovoltaic devices. This paper proposes a new technology for the production of solar cells in order to investigate a better utilization of solar spectrum of TiO2 doped with erbium (Er{sup 3+}), proven by energetic conversion. The Ti{sub 0,9}Er{sub 0,1}O2 system was obtained by Pechini method. Nanoparticles have a crystallite size 65.30 nm and surface area 118.48 m{sup 2}/g. These characteristics are essential for the formation of the film to be deposited on the conductive glass substrate constituting the cell's photoelectrode. The other side of the cell is the platinum counter electrode. The cell will have the faces sealed by a thermoplastic and, finally the electrolyte will be inserted, then they will be electrically evaluated through energy efficiency and confronted with the literature data base. (author)

  16. Sistema inteligente con visión artificial para el reconocimiento de piezas mecánicas en el Robot NAO

    OpenAIRE

    Cadena Castro, Lenin Marcel; Heredia López, Jonathan Alejandro

    2018-01-01

    This document details the construction and operation of an intelligent system with artificial vision, this is composed of two algorithms: first it is recognition and identification of mechanical parts through Hu's invariant moments and an artificial neural network in MATLAB software. Second is based on the identification of color patterns through the OpenCV library in Python for robot orientation. It do an intercommunication between MATLAB-Python software through the VSP program (Virtual Seri...

  17. [Mechanism of "treating heart and brain with same methods" based on data science].

    Science.gov (United States)

    Chen, Di; Tang, Shi-huan; Lu, Peng; Yang, Hong-jun

    2015-11-01

    The traditional Chinese medicine (TCM) theory of "treating heart and brain diseases with same methods (Nao Xin Tong Zhi: NXTZ)" has great significance to the treatment of cardiovascular and cerebrovascular diseases. It has been proven effective by a great deal of clinical researches. However, the underlying mechanism for this theory is still unclear. To provide insights into the potential mechanism of "NXTZ", this study attempts to deeply investigate the mechanism from two representative cardiovascular and cerebrovascular diseases, coronary heart disease (CHD) and cerebral apoplexy. First, various data resources were integrated to obtain different types of biomedical entities including drugs, targets, pathways and diseases. Then, three different approaches including text mining, biological network and enrichment analysis were utilized to recognize the potential common features between CHD and cerebral apoplexy, and the corresponding functions of drugs which could treat both diseases, thus unveiling the mechanism of NXTZ.

  18. Photometric redshifts for Hyper Suprime-Cam Subaru Strategic Program Data Release 1

    Science.gov (United States)

    Tanaka, Masayuki; Coupon, Jean; Hsieh, Bau-Ching; Mineo, Sogo; Nishizawa, Atsushi J.; Speagle, Joshua; Furusawa, Hisanori; Miyazaki, Satoshi; Murayama, Hitoshi

    2018-01-01

    Photometric redshifts are a key component of many science objectives in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP). In this paper, we describe and compare the codes used to compute photometric redshifts for HSC-SSP, how we calibrate them, and the typical accuracy we achieve with the HSC five-band photometry (grizy). We introduce a new point estimator based on an improved loss function and demonstrate that it works better than other commonly used estimators. We find that our photo-z's are most accurate at 0.2 ≲ zphot ≲ 1.5, where we can straddle the 4000 Å break. We achieve σ[Δzphot/(1 + zphot)] ˜ 0.05 and an outlier rate of about 15% for galaxies down to i = 25 within this redshift range. If we limit ourselves to a brighter sample of i https://hsc-release.mtk.nao.ac.jp/".

  19. Comparing survey and assessment data: Consequences for stock evaluation of Northeast Arctic Greenland halibut

    Directory of Open Access Journals (Sweden)

    Ole Thomas Albert

    2003-04-01

    Full Text Available Based on VPA-estimates of abundance, survey data and commercial catch statistics of Northeast Arctic Greenland halibut (Reinhardtius hippoglossoides Walbaum, the paper describes trends by year-class and age in the distribution of Greenland halibut between surveyed and not-surveyed areas. Changes in the distribution of I-group around 1990 to areas beyond the Svalbard surveys has previously been described and related to temperature changes in the Spitsbergen Current. This paper shows that this displaced distribution of the 1989-94 year-classes persisted up to age 7. The results indicate that the displacement was an extraordinary situation and other similar distribution shifts have not occurred during the last 30 years or more. Further, the shift co-occurred with extreme levels of the 137 year long time series of the index of the North-Atlantic Oscillation (NAO. The results are discussed in relation to stock management and climate change.

  20. Ver o que aconteceu: Cinema e Histria em Griffith e Spielberg Regarding what happened: Cinema and History in Griffith and Spielberg

    Directory of Open Access Journals (Sweden)

    Eduardo Victorio Morettin

    2012-01-01

    Full Text Available O objetivo deste texto discutir as conexes entre o discurso histrico e cinematogrfico, a partir das estratgias de autenticao em O Nascimento de uma Nao (The Birth of Nation, 1915, de David Griffith, e Amistad (1997, de Steven Spielberg. Sero examinadas as leituras que os filmes fazem da representao do tema da escravido e os vnculos com o contexto em que foram produzidos, analisando tambm as questes de estilo presentes nas duas obras.This text aims at discussing the connections between the historical and cinematographic discourse, starting from the authentication strategies employed by two films: The Birth of Nation (1915, from David Griffith, and Amistad (1997, from Steven Spielberg. This article will examine the different interpretations of the slavery theme and the link to the context in which they were produced, including the analysis of the style used on these two films.