Sample records for strong decadal variations

  1. Decadal variations in groundwater quality

    DEFF Research Database (Denmark)

    Jessen, Søren; Postma, Dieke; Thorling, Lærke


    Twenty-five years of groundwater quality monitoring in a sandy aquifer beneath agricultural fields showed large temporal and spatial variations in major ion groundwater chemistry, which were linked closely to the nitrate (NO3) content of agricultural recharge. Between 1988 and 2013, the NO3 content...... loading. Agriculture thus is an important determinant of major ion groundwater chemistry. Temporal and spatial variations in the groundwater quality were simulated using a 2D reactive transport model, which combined effects of the historical NO3 leaching and denitrification, with dispersive mixing...

  2. General strongly nonlinear variational inequalities

    International Nuclear Information System (INIS)

    Siddiqi, A.H.; Ansari, Q.H.


    In this paper we develop iterative algorithms for finding approximate solutions for new classes of variational and quasi-variational inequalities which include, as special case, some known results in this field. It is shown that the solutions of the iterative schemes converge to the exact solutions. (author). 15 refs

  3. Decadal variation of ocean heat content and tropical cyclone activity ...

    Indian Academy of Sciences (India)

    made to examine the inter-decadal variations of tropical cyclone (TC) activity and OHC700 over the. Bay of Bengal (BOB) for the .... Decadal variation of OHC and TC activity over the Bay of Bengal. 67 available because of its ..... In: Climate change 2007: The physical science basis (eds). Solomon S, Qin D, Manning M, ...

  4. Spatial and decadal variations in satellite-based terrestrial ...

    Indian Academy of Sciences (India)

    Zhaolu Zhang


    s12040-017-0885-0. Spatial and decadal variations in satellite-based terrestrial evapotranspiration and drought over. Inner Mongolia Autonomous Region of China during 1982–2009. Zhaolu Zhang1, Hui Kang2, Yunjun Yao3,.

  5. Spatial and decadal variations in satellite-based terrestrial ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 8. Spatial and decadal variations in ... Ayad M Fadhil Yuhu Zhang Kun Jia. Volume 126 Issue 8 December 2017 Article ID 119 ... of Kufa, Najaf 34003, Iraq. College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.

  6. Solvability of Extended General Strongly Mixed Variational Inequalities

    Directory of Open Access Journals (Sweden)

    Balwant Singh Thakur


    Full Text Available In this paper, a new class of extended general strongly mixed variational inequalities is introduced and studied in Hilbert spaces. An existence theorem of solution is established and using resolvent operator technique, a new iterative algorithm for solving the extended general strongly mixed variational inequality is suggested. A convergence result for the iterative sequence generated by the new algorithm is also established.

  7. Strong Convergence Theorems for Variational Inequalities and Split Equality Problem

    Directory of Open Access Journals (Sweden)

    Yu Jing Wu


    Full Text Available Let H1, H2, and H3 be real Hilbert spaces, let C⊆H1, Q⊆H2 be two nonempty closed convex sets, and let A:H1→H3, B:H2→H3 be two bounded linear operators. The split equality problem (SEP is to find x∈C, y∈Q such that Ax=By. Let H=H1×H2; consider f:H→H a contraction with coefficient 00, and M:H→H is a β-inverse strongly monotone mapping. Let 0<γ<γ̅/α, S=C×Q and G:H→H3 be defined by restricting to H1 is A and restricting to H2 is -B, that is, G has the matrix form G=[A,-B]. It is proved that the sequence {wn}={(xn,yn}⊆H generated by the iterative method wn+1=PS[αnγf(wn+(I-αnTPS(I-γnG*GPS(wn-λnMwn] converges strongly to w̃ which solves the SEP and the following variational inequality: 〈(T-λfw̃,w-w̃〉≥0 and 〈Mw̃,w-w̃〉≥0 for all w∈S. Moreover, if we take M=G*G:H→H,  γn=0, then M is a β-inverse strongly monotone mapping, and the sequence {wn} generated by the iterative method wn+1=αnγf(wn+(I-αnTPS(wn-λnG*Gwn converges strongly to w̃ which solves the SEP and the following variational inequality: 〈(T-λfw̃,w-w̃〉≥0 for all w∈S.

  8. Simulations of Turbulent Flows with Strong Shocks and Density Variations

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Xiaolin


    In this report, we present the research efforts made by our group at UCLA in the SciDAC project Simulations of turbulent flows with strong shocks and density variations. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-equilibrium flow and simulation of shock-turbulence interaction physics for very strong shocks. Such simulation has not been possible before because the limitation of conventional shock capturing methods. The limitation of shock Mach number is removed by using our high-order shock-fitting scheme. With the help of DOE and TeraGrid/XSEDE super computing resources, we have obtained new results which show new trends of turbulence statistics behind the shock which were not known before. Moreover, we are also developing tools to consider multi-species non-equilibrium flows. The main results are in three areas: (1) development of high-order shock-fitting scheme for perfect gas flow, (2) Direct Numerical Simulation (DNS) of interaction of realistic turbulence with moderate to very strong shocks using super computing resources, and (3) development and implementation of models for computation of mutli-species non-quilibrium flows with shock-fitting codes.

  9. Variations of Background Seismic Noise Before Strong Earthquakes, Kamchatka. (United States)

    Kasimova, V.; Kopylova, G.; Lyubushin, A.


    The network of broadband seismic stations of Geophysical Service (Russian Academy of Science) works on the territory of Kamchatka peninsula in the Far East of Russia. We used continuous records on Z-channels at 21 stations for creation of background seismic noise time series in 2011-2017. Average daily parameters of multi-fractal spectra of singularity have been calculated at each station using 1-minute records. Maps and graphs of their spatial distribution and temporal changes were constructed at time scales from days to several years. The analysis of the coherent behavior of the time series of the statistics was considered. The technique included the splitting of seismic network into groups of stations, taking into account the coastal effect, the network configuration and the main tectonic elements of Kamchatka. Then the time series of median values of noise parameters from each group of stations were made and the frequency-time diagrams of the evolution of the spectral measure of the coherent behavior of four time series were analyzed. The time intervals and frequency bands of the maximum values showing the increase of coherence in the changes of all statistics were evaluated. The strong earthquakes with magnitudes M=6.9-8.3 occurred near the Kamchatka peninsula during the observations. The synchronous variations of the background noise parameters and increase in the coherent behavior of the median values of statistical parameters was shown before two earthquakes 2013 (February 28, Mw=6.9; May 24, Mw=8.3) within 3-9 months and before earthquake of January 30, 2016, Mw=7.2 within 3-6 months. The maximum effect of increased coherence in the range of periods 4-5.5 days corresponds to the time of preparation of two strong earthquakes in 2013 and their aftershock processes. Peculiarities in changes of statistical parameters at stages of preparation of strong earthquakes indicate the attenuation in high-amplitude outliers and the loss of multi-fractal properties in

  10. Evidence for Interannual to Decadal Variations in Hadley and Walker Circulations and Links to Water and Energy Fluxes (United States)

    Robertson, Franklin; Bosilovich, Michael; Miller, Timothy


    Mass and energy transports associated with the Hadley and Walker circulations are important components of the earth s climate system and are strongly linked to hydrologic processes. Interannual to decadal variation in these flows likely signify a combination of natural climate noise as well as a response to anthropgenic forcing. There remains considerable uncertainty in quantifying variations in these flows. Evidence in the surface pressure record supports a weakening of the Walker circulation over the Pacific in recent decades. Conversely the NCEP / NCAR and ERA 40 reanalyses indicate that the Hadley circulation has increased in strength over the last two decades, though these analyses depict significantly different mass circulation changes. Interestingly, the NCEP - II / DOE reanalysis contains essentially no Hadley circulation changes. Most climate model integrations anticipate a weakening of both tropical circulations associated with stronger static stability. Clearly there is much uncertainty not only with the mass transports, but also how they are linked to water and energy balance of the planet through variations in turbulent heat and radiative fluxes and horizontal exports / imports of energy. Here we examine heat and water budget variations from a number of reanalysis products and focus on the linear and nonlinear response of ENSO warm and cold events as opportunities to study budget variations over the past 15-20 years. Our analysis addresses such questions as To what extent do Hadley and Walker Cell variations compensate each other on mass and energy transport? Do static stability adjustments appear to constrain fractional precipitation response vs. fractional water vapor response? We appeal to constraints offered by GPCP precipitation, SSWI ocean evaporation estimates, and ISCCP-FD radiative fluxes, and other satellite data sets to interpret and confirm reanalysis-based diagnostics. Using our findings we also attempt to place in context the recent

  11. Decadal variation of the impact of La Niña on the winter Arctic stratosphere (United States)

    Yang, Shuangyan; Li, Tim; Hu, Jinggao; Shen, Xi


    The impact of La Niña on the winter Arctic stratosphere has thus far been an ambiguous topic of research. Contradictory results have been reported depending on the La Niña events considered. This study shows that this is mainly due to the decadal variation of La Niña's impact on the winter Arctic stratosphere since the late 1970s. Specifically, during the period 1951-78, the tropospheric La Niña teleconnection exhibits a typical negative Pacific-North America pattern, which strongly inhibits the propagation of the planetary waves from the extratropical troposphere to the stratosphere, and leads to a significantly strengthened stratospheric polar vortex. In contrast, during 1979-2015, the La Niña teleconnection shifts eastwards, with an anomalous high concentrated in the northeastern Pacific. The destructive interference of the La Niña teleconnection with climatological stationary waves seen in the earlier period reduces greatly, which prevents the drastic reduction of planetary wave activities in the extratropical stratosphere. Correspondingly, the stratospheric response shows a less disturbed stratospheric polar vortex in winter.

  12. Response of decadal climatic variations to solar signals in the coastal region of the Barents Sea (United States)

    Raspopov, O. M.; Dergachev, V. A.; Shumilov, O. I.; Nevanlinna, H.


    Variations in annual temperatures in the coastal region of the Barents sea in Murmansk (69 N, 33 E) for the period of instrumental records since 1878 have been analyzed. Annual temperature variations have been found to exhibit a pronounced decadal periodicity of the order of 1-1.8 degrees Celsius. Comparison of temperature variations with variations in solar activity (Wolf numbers W) point to the synchronism between decadal temperature variations and the 11-year Schwabe solar cycle. Spectral analysis of the tree ring growth (Pinus Sylvestris L.) in Tuloma Valley near Murmansk for the last 350 years has revealed variations in the tree ring growth with a period of 11-12 years. Thus, decadal climatic variations with the period of the Schwabe solar cycle are typical of the coastal region of the Barents sea. The amplitudes of the observed temperature variations (1-1.8 degrees Celsius) cannot be interpreted as resulting from changes in solar irradiation during the 11-year cycle. These changes are of the order of 0.15%, which can lead to the global temperature response of the order of 0.1-0.3 degrees Celsius. Therefore, a 5-6-fold enhancement of the solar signals takes place in the coastal region of the Barents sea. A similar solar signal enhancement was revealed earlier in variations in the Sea Surface Temperature (SST) in the Pacific Ocean. Possible reasons for enhancement of solar signals in variations in SST in the Pacific Ocean were considered by White et al.(2000) on the basis of the model of the delayed action oscillator in the ocean-atmosphere-terrestrial system. It is probable that in the Northern Atlantic region a similar solar signal enhancement occurs in the ocean-atmosphere-terrestrial system. This work was supported by INTAS, Grant 97-31008; PFBR, Grant 00-05-64921 and NorFa.

  13. Variational Boussinesq model for strongly nonlinear dispersive waves

    NARCIS (Netherlands)

    Lawrence, C.; Adytia, D.; van Groesen, E.


    For wave tank, coastal and oceanic applications, a fully nonlinear Variational Boussinesq model with optimized dispersion is derived and a simple Finite Element implementation is described. Improving a previous weakly nonlinear version, high waves over flat and varying bottom are shown to be

  14. Decadal variations in geophysical processes and asymmetries in the solar motion about the Solar System's barycentre (United States)

    Sidorenkov, Nikolay; Wilson, Ian; Khlystov, Anatoly


    It is well known that many geophysical processes vary on inter-annual to decadal timescales. These variations are usually attributed to terrestrial causes that include: the Earth's core-mantle coupling, the effects of internal driven stochastic oscillations in the climatic system, the effects of the global conveyer belt in World Ocean and so on. However, we contend that the empirical evidences and facts demand that this generally accepted assumption should be revised and modified. We find that the observed changes in the specific mass of the Antarctic and Greenland ice sheets closely correspond to the specific mass variations that are needed to explain the "decadal-long" fluctuations in LOD (Sidorenkov, 2009). Since the mass of the ice sheets in Antarctic and Greenland depend on long-term climate variations, it is reasonable to assume that the decadal fluctuations in the Earth's rotation may also correlate with the fluctuations in the major climatic indices. Following this line of reasoning, we have found that the atmospheric circulation regimes and the ten-year running mean of the anomalies of the Northern Hemisphere air temperature are well correlated with the changes in the Earth's rotation rate. Stanislav Perov and Nikolay Sidorenkov (2009) found also significant correlation between fluctuations in the Earth's rotational rate and activity of the India monsoon. Ian Wilson (2009) found a relationship between the deviation of the Earth's LOD from its long-term trend and the Pacific Decadal Oscillation (PDO). Whenever there are large deviations in the Earth's LOD from its long--term trend, the PDO index transitions to its positive phase. Note that the observed changes in the LOD precede those in the anomalies of the precipitation in India monsoon and in the PDO by about eight years. Ian Wilson shows that the times when Solar/Lunar tides had their greatest impact upon the Earth are closely synchronized with the times of greatest asymmetry in the Solar Inertial

  15. Decadal variations in estimated surface solar radiation over Switzerland since the late 19th century

    Directory of Open Access Journals (Sweden)

    A. Sanchez-Lorenzo


    Full Text Available Our knowledge on trends in surface solar radiation (SSR involves uncertainties due to the scarcity of long-term time series of SSR, especially with records before the second half of the 20th century. Here we study the trends of all-sky SSR from 1885 to 2010 in Switzerland, which have been estimated using a homogenous dataset of sunshine duration series. This variable is shown to be a useful proxy data of all-sky SSR, which can help to solve some of the current open issues in the dimming/brightening phenomenon. All-sky SSR has been fairly stable with little variations in the first half of the 20th century, unlike the second half of the 20th century that is characterized also in Switzerland by a dimming from the 1950s to the 1980s and a subsequent brightening. Cloud cover changes seem to explain the major part of the decadal variability observed in all-sky SSR, at least from 1885 to the 1970s; at this point, a discrepancy in the sign of the trend is visible in the all-sky SSR and cloud cover series from the 1970s to the present. Finally, an attempt to estimate SSR series for clear-sky conditions, based also on sunshine duration records since the 1930s, has been made for the first time. The mean clear-sky SSR series shows no relevant changes between the 1930s to the 1950s, then a decrease, smaller than the observed in the all-sky SSR, from the 1960s to 1970s, and ends with a strong increase from the 1980s up to the present. During the three decades from 1981 to 2010 the estimated clear-sky SSR trends reported in this study are in line with previous findings over Switzerland based on direct radiative flux measurements. Moreover, the signal of the El Chichón and Pinatubo volcanic eruption visible in the estimated clear-sky SSR records further demonstrates the potential to infer aerosol-induced radiation changes from sunshine duration observations.

  16. Fives decades of strong temporal variability in the flow of the Brunt Ice Shelf, Antarctica (United States)

    De Rydt, Jan; Gudmundsson, Hilmar; Nagler, Thomas


    The Brunt Ice Shelf, East Antarctica, is a complex conglomerate of meteoric and marine ice, weakly connected to the much larger and faster-flowing Stancomb Wills Glacier Tongue to the east, and pinned down to the seabed in a small area around the McDonalds Ice Rumples in the north. The ice shelf is home to the UK research station Halley, from which changes to the ice shelf have been monitored closely since the 1960s. A unique 50-year record of the flow speed and an intense surveying programme over the past 10 years, have revealed a strong temporal variability in the flow. In particular, the speed of the ice shelf has increased by 10% each year over the past few years. In order to understand these rapid changes, we use a state-of-the-art flow model in combination with a range of satellite, ground-based and airborne radar data, to accurately simulate the historical flow and recent changes. In particular, we model the effects of a recently formed rift that is propagating at a speed of up to 600m/day and threatens to dislodge the ice shelf from its pinning point at the McDonalds Ice Rumples. We also report on the recent reactivation of a large chasm which has prompted the relocation of the station during the 2016/17 austral summer.

  17. Decadal water quality variations at three typical basins of Mekong, Murray and Yukon (United States)

    Khan, Afed U.; Jiang, Jiping; Wang, Peng


    Decadal distribution of water quality parameters is essential for surface water management. Decadal distribution analysis was conducted to assess decadal variations in water quality parameters at three typical watersheds of Murray, Mekong and Yukon. Right distribution shifts were observed for phosphorous and nitrogen parameters at the Mekong watershed monitoring sites while left shifts were noted at the Murray and Yukon monitoring sites. Nutrients pollution increases with time at the Mekong watershed while decreases at the Murray and Yukon watershed monitoring stations. The results implied that watershed located in densely populated developing area has higher risk of water quality deterioration in comparison to thinly populated developed area. The present study suggests best management practices at watershed scale to modulate water pollution.

  18. Variational Approaches to the Evolution and Control of Strongly Driven Quantum Systems. (United States)

    Widmayer, C. Clay

    Ongoing experimental advances, especially the advent of high intensity pulsed lasers, have produced the need for theoretical methods for modelling the behavior of quantum systems under the influence of strong driving fields. Despite decades of effort developing approaches adapted to strong driving, no single method enjoys the position of preeminence held by lowest order perturbation theory in the weak field regime. Three methods well suited to the time evolution of strongly driven systems are discussed and illustrated through numerical calculation. The impulse representation in which the time dependent Schrodinger equation is solved by switching to a shifted momentum space representation is described and applied to the problem of a hydrogen atom driven by a Stark kick for which the approach yields an exact solution. Using this result convenient exact closed form expressions for exctitation probabilities from the ground state are derived. Secondly, the time dependent variational method (TDVM) for obtaining approximate solutions to the Schrodinger equation by stationarizing an appropriately defined variational functional is discussed. A simple form of the equations of motion for time dependent variational parameters is derived and applied to the calculation of the radial wavefunction following the beta decay of tritium. Accurate values for time dependent observables are obtained by approximating the wavefunction as a superposition of the ground states of the Z = 1 and Z = 2 hydrogenic atoms. Finally, the control of quantum dynamics is considered and two methods are presented for deriving external fields for the purpose of driving a quantum system into a desired behavior. With the inverse control method a procedure is described for producing exact tracking of a time dependent observable. The method is applied to a two-level atom and is shown to lead to non-unique values of the driving field which exhibit undesirable numerical anomalies. The more robust method of

  19. Contribution of Phenological and Physiological Variations on Northern Vegetation Productivity Changes over Last Three Decades (United States)

    Ganguly, Sangram


    Plant phenology and maximum photosynthetic state determine spatiotemporal variability of gross primary productivity (GPP) of vegetation. Recent warming induced impacts accelerate shifts of phenology and physiological status over Northern vegetated land. Thus, understanding and quantifying these changes are very important. Here, we investigate 1) how vegetation phenology and physiological status (maximum photosynthesis) are evolved over last three decades and 2) how such components (phenology and physiological status) contribute on inter-annual variation of the GPP during the last three decades. We utilized both long-term remotely sensed (GIMMS (Global Inventory Modeling and Mapping Studies), NDVI3g (Normalized Difference Vegetation Index 3rd generation) and MODIS (Moderate Resolution Imaging Spectroradiometer)) to extract larger scale phenology metrics (growing season start, end and duration); and productivity (i.e., growing season integrated vegetation index, GSIVI) to answer these questions. For evaluation purpose, we also introduced field-measured phenology and productivity datasets (e.g., FLUXNET) and possible remotely-sensed and modeled metrics at continental and regional scales. From this investigation, we found that onset of the growing season has advanced by 1.61 days per decade and the growing season end has delayed by 0.67 days per decade over the circumpolar region. This asymmetric extension of growing season results in a longer growing-season trend (2.96 days per decade) and widespread increasing vegetation-productivity trend (2.96 GSIVI per decade) over Northern land. However, the regionally-diverged phenology shift and maximum photosynthetic state contribute differently characterized productivity, inter-annual variability and trend. We quantified that about 50 percent, 13 percent and 6.5 percent of Northern land's inter-annual variability are dominantly controlled by the onset of the growing season, the end of the growing season and the maximum

  20. Relevance of decadal variations in surface radiative fluxes for climate change (United States)

    Wild, Martin


    Recent evidence suggests that radiative fluxes incident at Earth's surface are not stable over time but undergo significant changes on decadal timescales. This is not only found in the thermal spectral range, where an increase in the downwelling flux is expected due to the increasing greenhouse effect, but also in the solar spectral range. Observations suggest that surface solar radiation, after a period of decline from the 1950s to the 1980s ("global dimming"), reversed into a "brightening" since the mid-1980s at widespread locations, often in line with changes in anthropogenic air pollution. These decadal variations observed in both solar and thermal surface radiative fluxes have the potential to affect various aspects of climate change. Discussed here are specifically the evidence for potential effects on global warming, as seen in asymmetries in hemispheric warming rates as well as in differences in the decadal warming rates over land and oceans. These variations in observed warming rates fit well to our conceptual understanding of how aerosol and greenhouse gas-induced changes in the surface radiative fluxes should affect global warming. Specifically, on the Northern Hemisphere, the suppression of warming from the 1950s to the 1980s fits to the concurrent dimming and increasing air pollution, while the accelerated warming from the 1980s to 2000 matches with the brightening and associated reduction in pollution levels. The suppression of warming from the 1950s to the 1980s is even somewhat stronger over oceans than over land, in line with the conceptual idea that aerosol-induced dimming and brightening tendencies may be enhanced through cloud aerosol interactions particularly over the pristine ocean areas. On the Southern Hemisphere, the absence of significant pollution levels as well as trend reversals therein, fit to the observed stable warming rates over the entire 1950 to 2000 period.

  1. Decadal variations in diatoms and dinoflagellates on the inner shelf of the East China Sea, China (United States)

    Abate, Rediat; Gao, Yahui; Chen, Changping; Liang, Junrong; Mu, Wenhua; Kifile, Demeke; Chen, Yanghang


    Diatoms and dinoflagellates are two major groups of phytoplankton that flourish in the oceans, particularly in coastal zone and upwelling systems, and their contrasting production have been reported in several world seas. However, this information is not available in the coastal East China Sea (ECS). Thus, to investigate and compare the decadal trends in diatoms and dinoflagellates, a sediment core, 47 cm long, was collected from the coastal zone of the ECS. Sediment chlorophyll- a (Chl- a), phytoplankton-group specific pigment signatures of diatoms and dinoflagellates, and diatom valve concentrations were determined. The sediment core covered the period from 1961 to 2011 AD. The chlorophyll- a contents ranged from 2.32 to 73 µg/g dry sediment (dw) and averaged 9.81 µg/g dw. Diatom absolute abundance ranged from 29152 to 177501 valve/gram (v/g) dw and averaged 72137 v/g dw. Diatom valve and diatom specific pigment marker concentrations were not significantly correlated. Peridinin increased after the 1980s in line with intensified use of fertilizer and related increases in nutrient inputs into the marine environment. The increased occurrence of dinoflagellate dominance after the 1980s can be mostly explained by the increase in nutrients. However, the contribution of dinoflagellates to total phytoplankton production (Chl- a) decreased during the final decade of this study, probably because of the overwhelming increase in diatom production that corresponded with the construction of the Three Gorges Dam (TGD) and related light availability. Similarly, the mean ratio of fucoxanthin/peridinin for the period from 1982 to 2001 was 6% less than for 1961 to 1982, while the ratio for 2001 to 2011 was 45.3% greater than for 1982 to 2001. The decadal variation in the fucoxanthin/peridinin ratio implies that dinoflagellate production had been gradually increasing until 2001. We suggest that the observed changes can be explained by anthropogenic impacts, such as nutrient

  2. Decadal climate variation recorded in modern global carbonate archives (brachiopods, molluscs) (United States)

    Romanin, Marco; Zaki, Amir H.; Davis, Alyssa; Shaver, Kristen; Wang, Lisha; Aleksandra Bitner, Maria; Capraro, Luca; Preto, Nereo; Brand, Uwe


    The progress of the Earth's warming trend has rapidly accelerated in the last few decades due to the increase in emission of anthropogenic greenhouse gases. The exchange of heat between the atmosphere and seawater has consequently elevated the rate of temperature buildup in the low and high latitude ocean. Records of the variation in seawater temperature in response to local and global changes in climate are preserved within the carbonate structures of marine biogenic archives. Investigating the isotopic composition of the archives' growth increments documents the magnitude of sea surface temperature (SST) change. A long-term (1956-2012) record of temperature change in sub-tropical seawater was acquired from the giant clam Tridacna maxima collected from the Red Sea in conjunction with published results of the oyster Hyotissa hyotis (Titschack et al., 2010). Variation in polar-subpolar SST was obtained from the brachiopod Magellania venosa recovered from the coastal area of southern Chile, and from the proxy record of Hemithiris psittacea of Hudson Bay (Brand et al., 2014). The former reveals a long-term (1961-2012) time-series of Antarctic-induced oceanographic change in the southern hemisphere, while the latter represents a trend of Hudson Bay seawater SST in the northern hemisphere. Evaluation of the isotopic compositions confirms the equilibrium incorporation of oxygen isotopes with respect to ambient seawater in brachiopods and some bivalves. A general trend of decreasing δ18O values in the Red Sea molluscs is observed, indicating an increase in tropical seawater temperature of about 0.79°C since 1988. The δ18O values of the polar-subpolar brachiopods display similar depletion slopes but of larger magnitudes than that of the Red Sea archives. This signifies a rise in seawater temperature of about 1.47°C in Hudson Bay since 1991, and about 2.08°C in southern Chile since 1988. The 2013 IPCC report suggests an increase in SST of +0.094°C per decade (average

  3. Two decades of spatiotemporal variations in subduction zone coupling offshore Japan (United States)

    Loveless, John P.; Meade, Brendan J.


    Spatial patterns of interplate coupling on global subduction zones can be used to guide seismic hazard assessment, but estimates of coupling are often constrained using a limited temporal range of geodetic data. Here we analyze ∼19 years of geodetic observations from the GEONET network to assess time-dependent variations in the spatial distribution of coupling on the subduction zones offshore Japan. We divide the position time series into five, ∼3.75-year epochs each decomposed into best-fit velocity, annual periodic signals, coseismic offsets, and postseismic effects following seven major earthquakes. Nominally interseismic velocities are interpreted in terms of a combination of tectonic block motions and earthquake cycle activity. The duration of the inferred postseismic activity covaries with the linear velocity. To address this trade-off, we assume that the nominally interseismic velocity at each station varies minimally from epoch to epoch. This approach is distinct from prior time-series analysis across the earthquake cycle in that position data are not detrended using preseismic velocity, which inherently assumes that interseismic processes are spatially stable through time, but rather the best-fit velocity at each station may vary between epochs. These velocities reveal significant consistency since 1996 in the spatial distribution of coupling on the Nankai subduction zone, with variation limited primarily to the Tokai and Bungo Channel regions, where long-term slow slip events have occurred, and persistently coupled regions coincident with areas that slipped during historic great earthquakes. On the Sagami subduction zone south of Tokyo, we also estimate relatively stable coupling through time. On the Japan-Kuril Trench, we image significant coupling variations owing to effects of the 1994 MW = 7.7 Sanriku-oki, 2003 MW = 8.2 Tokachi-oki, and 2011 MW = 9.0 Tohoku-oki earthquakes. In particular, strong coupling becomes more spatially extensive following

  4. Universal characterization of wall turbulence for fluids with strong property variations

    NARCIS (Netherlands)

    Patel, A.


    Wall-bounded turbulence involving mixing of scalars, such as temperature or concentration fields, play an important role in many engineering applications. In applications with large temperature or concentration differences, the variation of scalar dependent thermos physical properties can be strong.

  5. Decadal-scale variations in geomagnetic field intensity from ancient Cypriot slag mounds (United States)

    Shaar, Ron; Tauxe, Lisa; Ben-Yosef, Erez; Kassianidou, Vasiliki; Lorentzen, Brita; Feinberg, Joshua M.; Levy, Thomas E.


    Geomagnetic models based on direct observations since the 1830s show that the averaged relative change in field intensity on Earth's surface over the past 170 years is less than 4.8% per decade. It is unknown if these rates represent the typical behavior of secular variations due to insufficient temporal resolution of archaeomagnetic records from earlier periods. To address this question, we investigate two ancient slag mounds in Cyprus—Skouriotissa Vouppes (SU1, fourth to fifth centuries CE, 21 m in height), and Mitsero Kokkinoyia (MK1, seventh to fifth centuries BCE, 8 m in height). The mounds are multilayered sequences of slag and charcoals that accumulated near ancient copper production sites. We modeled the age-height relation of the mounds using radiocarbon dates, and estimated paleointensities using Thellier-type IZZI experiments with additional anisotropy, cooling rate, and nonlinear TRM assessments. To screen out ambiguous paleointensity interpretations, we applied strict selection criteria at the specimen/sample levels. To ensure objectivity, consistency, and robust error estimation, we employed an automatic interpretation technique and put the data available in the MagIC database. The analyses yielded two independent subcentury-scale paleointensity time series. The MK1 data indicate relatively stable field at the time the mound accumulated. In contrast, the SU1 data demonstrate changes that are comparable in magnitude to the fastest changes inferred from geomagnetic models. We suggest that fast changes observed in the published archaeomagnetic data from the Levant are driven by two longitudinally paired regions, the Middle East and South Africa, that show unusual activity in geomagnetic models.

  6. Massive genomic variation and strong selection in Arabidopsis thaliana lines from Sweden (United States)

    Platzer, Alexander; Zhang, Qingrun; Vilhjálmsson, Bjarni J; Korte, Arthur; Nizhynska, Viktoria; Voronin, Viktor; Korte, Pamela; Sedman, Laura; Mandáková, Terezie; Lysak, Martin A; Seren, Ümit; Hellmann, Ines; Nordborg, Magnus


    Despite advances in sequencing, the goal of obtaining a comprehensive view of genetic variation in populations is still far from reached. We sequenced 180 lines of A. thaliana from Sweden to obtain as complete a picture as possible of variation in a single region. Whereas simple polymorphisms in the unique portion of the genome are readily identified, other polymorphisms are not. The massive variation in genome size identified by flow cytometry seems largely to be due to 45S rDNA copy number variation, with lines from northern Sweden having particularly large numbers of copies. Strong selection is evident in the form of long-range linkage disequilibrium (LD), as well as in LD between nearby compensatory mutations. Many footprints of selective sweeps were found in lines from northern Sweden, and a massive global sweep was shown to have involved a 700-kb transposition. PMID:23793030

  7. Implementation of an optimal first-order method for strongly convex total variation regularization

    DEFF Research Database (Denmark)

    Jensen, Tobias Lindstrøm; Jørgensen, Jakob Heide; Hansen, Per Christian


    We present a practical implementation of an optimal first-order method, due to Nesterov, for large-scale total variation regularization in tomographic reconstruction, image deblurring, etc. The algorithm applies to μ-strongly convex objective functions with L-Lipschitz continuous gradient....... In the framework of Nesterov both μ and L are assumed known—an assumption that is seldom satisfied in practice. We propose to incorporate mechanisms to estimate locally sufficient μ and L during the iterations. The mechanisms also allow for the application to non-strongly convex functions. We discuss...

  8. Impacts of meteorological parameters and emissions on decadal, interannual, and seasonal variations of atmospheric black carbon in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Yu-Hao Mao


    Full Text Available We quantified the impacts of variations in meteorological parameters and emissions on decadal, interannual, and seasonal variations of atmospheric black carbon (BC in the Tibetan Plateau for 1980–2010 using a global 3-dimensional chemical transport model driven by the Modern Era Retrospective-analysis for Research and Applications (MERRA meteorological fields. From 1980 to 2010, simulated surface BC concentrations and all-sky direct radiative forcing at the top of the atmosphere due to atmospheric BC increased by 0.15 μg m−3 (63% and by 0.23 W m−2 (62%, respectively, averaged over the Tibetan Plateau (75–105°E, 25–40°N. Simulated annual mean surface BC concentrations were in the range of 0.24–0.40 μg m−3 averaged over the plateau for 1980–2010, with the decadal trends of 0.13 μg m−3 per decade in the 1980s and 0.08 in the 2000s. The interannual variations were −5.4% to 7.0% for deviation from the mean, 0.0062 μg m−3 for mean absolute deviation, and 2.5% for absolute percent departure from the mean. Model sensitivity simulations indicated that the decadal trends of surface BC concentrations were mainly driven by changes in emissions, while the interannual variations were dependent on variations of both meteorological parameters and emissions. Meteorological parameters played a crucial role in driving the interannual variations of BC especially in the monsoon season.

  9. Sea level rise, surface warming, and the weakened buffering ability of South China Sea to strong typhoons in recent decades. (United States)

    Sun, Jingru; Oey, Leo; Xu, F-H; Lin, Y-C


    Each year, a number of typhoons in the western North Pacific pass through the Luzon Strait into South China Sea (SCS). Although the storms remain above a warm open sea, the majority of them weaken due to atmospheric and oceanic environments unfavorable for typhoon intensification in SCS, which therefore serves as a natural buffer that shields the surrounding coasts from potentially more powerful storms. This study examines how this buffer has changed over inter-decadal and longer time scales. We show that the buffer weakens (i.e. greater potential for more powerful typhoons) in negative Pacific Decadal Oscillation (PDO) years, as well as with sea-level-rise and surface warming, caused primarily by the deepening of the ocean's 26 °C isotherm Z 26 . A new Intensity Change Index is proposed to describe the typhoon intensity change as a function of Z 26 and other environmental variables. In SCS, the new index accounts for as high as 75% of the total variance of typhoon intensity change.

  10. Decadal Variation in the Rainfall Characteristics over River Basins across the Western Ghats of India (United States)

    Bhat, R.; Gouda, K. C.; Murthy, A.; Prabhuraj, D. K.; Laxmikantha, B. P.


    Rainfall over a river basin have high impact on the human life in the coastal region, in particular during monsoon season. In the present work the rainfall characteristics over Uttara Kannada district of Karnataka, India is studied in decadal to annual scale. The specialty of the district is, here a network of five river basins exist and all rivers flow into the Arabian Sea in the west coast of India. Being a part of the Western Ghats region all these rivers have different hydrological and geological properties. All the rivers are mainly rain fed in nature. The Significant uncertainties in annual precipitation and extreme precipitation events over the basin are due to the uncertainties in the atmospheric parameters like temperature, offshore wind, humidity etc. In this study, TRMM, GPCP and India Meteorological Department (IMD) measured rainfall data were used to analyze the decadal rainfall analysis over the basin. It is found that the overall trend of rainfall is decreasing from 1951 to 2000 where as the monsoon (June-September) rainfall seems to be normal. The extreme rainfall events seem to have increased in the recent decade compare to the earlier decades. The rainfall decreases towards East compared to the west part of the basin. The surface water potential, evapo transpiration, soil temperature, soil moisture of the basin is studied and empirical relation with the rainfall presented in this work.

  11. Decadal Variations in Eastern Canada's Taiga Wood Biomass Production Forced by Ocean-Atmosphere Interactions. (United States)

    Boucher, Etienne; Nicault, Antoine; Arseneault, Dominique; Bégin, Yves; Karami, Mehdi Pasha


    Across Eastern Canada (EC), taiga forests represent an important carbon reservoir, but the extent to which climate variability affects this ecosystem over decades remains uncertain. Here, we analyze an extensive network of black spruce (Picea mariana Mill.) ring width and wood density measurements and provide new evidence that wood biomass production is influenced by large-scale, internal ocean-atmosphere processes. We show that while black spruce wood biomass production is primarily governed by growing season temperatures, the Atlantic ocean conveys heat from the subtropics and influences the decadal persistence in taiga forests productivity. Indeed, we argue that 20-30 years periodicities in Sea Surface Temperatures (SSTs) as part of the the Atlantic Multi-decadal Oscillation (AMO) directly influence heat transfers to adjacent lands. Winter atmospheric conditions associated with the North Atlantic Oscillation (NAO) might also impact EC's taiga forests, albeit indirectly, through its effect on SSTs and sea ice conditions in surrounding seas. Our work emphasizes that taiga forests would benefit from the combined effects of a warmer atmosphere and stronger ocean-to-land heat transfers, whereas a weakening of these transfers could cancel out, for decades or longer, the positive effects of climate change on Eastern Canada's largest ecosystem.

  12. Does metabolic health in overweight and obesity persist? - Individual variation and cardiovascular mortality over two decades


    Kaur, A; Johnston, DG; Godsland, IF


    Overweight and obese individuals may be metabolically healthy, but attention needs to be given to long-term persistence of this trait and any associated variation in cardiovascular risk.Cross-sectional and longitudinal variation in metabolic health and associated cardiovascular mortality were analysed in 1099 white European-origin normal-weight and overweight or obese males followed for 20years.Definitions of metabolic health were based on LDL and HDL cholesterol, triglycerides, blood pressur...

  13. Routine daily physical activity and glucose variations are strongly coupled in adults with T1DM. (United States)

    Farabi, Sarah S; Carley, David W; Cinar, Ali; Quinn, Lauretta


    Type 1 Diabetes (T1DM) is characterized by altered glucose homeostasis resulting in wide glucose variations throughout a 24-h period. The relationship between routine daily physical activity and glucose variations has not been systematically investigated in adults with T1DM. The objectives of this study were to characterize and quantify the relationship between routine daily activity and glucose variations in a small group of adults with T1DM. Adults with T1DM treated with an insulin pump were recruited for the study. Over a 3-day period, glucose variations were monitored with a continuous glucose monitoring system (CGMS) and routine daily physical activity was assessed using an accelerometer-based physical activity-monitoring band. Simultaneous glucose and physical activity data for one 24-h period were used for analysis. Cross-correlation function and wavelet coherence analyses were employed to quantify the coupling between physical activity and glucose. Twelve subjects were included in the analysis. Cross-correlation function analysis revealed strong coupling between activity and glucose. Wavelet Coherence demonstrated that slower oscillations (120-340 min) of glucose and physical activity exhibited significantly greater coherence (F = 12.6, P < 0.0001) than faster oscillations (10 and 120 min). Physical activity and glucose demonstrate strong time and frequency-dependent coupling throughout a 24-h time period in adults with T1DM. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  14. Age- and gender-related regional variations of human brain cortical thickness, complexity, and gradient in the third decade. (United States)

    Creze, Maud; Versheure, Leslie; Besson, Pierre; Sauvage, Chloe; Leclerc, Xavier; Jissendi-Tchofo, Patrice


    Brain functional and cytoarchitectural maturation continue until adulthood, but little is known about the evolution of the regional pattern of cortical thickness (CT), complexity (CC), and intensity or gradient (CG) in young adults. We attempted to detect global and regional age- and gender-related variations of brain CT, CC, and CG, in 28 healthy young adults (19-33 years) using a three-dimensional T1 -weighted magnetic resonance imaging sequence and surface-based methods. Whole brain interindividual variations of CT and CG were similar to that in the literature. As a new finding, age- and gender-related variations significantly affected brain complexity (P age), and the fronto-orbital cortex (gender), all in the right hemisphere. Regions of interest analyses showed age and gender significant interaction (P learning plasticity in young adults' brain in the third decade. Copyright © 2013 Wiley Periodicals, Inc.

  15. Strong convergence with a modified iterative projection method for hierarchical fixed point problems and variational inequalities

    Directory of Open Access Journals (Sweden)

    Ibrahim Karahan


    Full Text Available Let C be a nonempty closed convex subset of a real Hilbert space H. Let {T_{n}}:C›H be a sequence of nearly nonexpansive mappings such that F:=?_{i=1}^{?}F(T_{i}?Ø. Let V:C›H be a ?-Lipschitzian mapping and F:C›H be a L-Lipschitzian and ?-strongly monotone operator. This paper deals with a modified iterative projection method for approximating a solution of the hierarchical fixed point problem. It is shown that under certain approximate assumptions on the operators and parameters, the modified iterative sequence {x_{n}} converges strongly to x^{*}?F which is also the unique solution of the following variational inequality: ?0, ?x?F. As a special case, this projection method can be used to find the minimum norm solution of above variational inequality; namely, the unique solution x^{*} to the quadratic minimization problem: x^{*}=argmin_{x?F}?x?². The results here improve and extend some recent corresponding results of other authors.

  16. Strong Dependence of U.S. Summertime Air Quality on the Decadal Variability of Atlantic Sea Surface Temperatures (United States)

    Shen, Lu; Mickley, Loretta J.; Leibensperger, Eric M.; Li, Mingwei


    We find that summertime air quality in the eastern U.S. displays strong dependence on North Atlantic sea surface temperatures, resulting from large-scale ocean-atmosphere interactions. Using observations, reanalysis data sets, and climate model simulations, we further identify a multidecadal variability in surface air quality driven by the Atlantic Multidecadal Oscillation (AMO). In one-half cycle ( 35 years) of the AMO from cold to warm phase, summertime maximum daily 8 h ozone concentrations increase by 1-4 ppbv and PM2.5 concentrations increase by 0.3-1.0 μg m-3 over much of the east. These air quality changes are related to warmer, drier, and more stagnant weather in the AMO warm phase, together with anomalous circulation patterns at the surface and aloft. If the AMO shifts to the cold phase in future years, it could partly offset the climate penalty on U.S. air quality brought by global warming, an effect which should be considered in long-term air quality planning.

  17. Decadal trends in the diurnal variation of galactic cosmic rays observed using neutron monitor data

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Simon [Reading Univ. (United Kingdom). Dept. of Meteorology; Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.; Owens, Mathew; Lockwood, Mike [Reading Univ. (United Kingdom). Dept. of Meteorology; Owen, Chris [Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.


    The diurnal variation (DV) in galactic cosmic ray (GCR) flux is a widely observed phenomenon in neutron monitor data. The background variation considered primarily in this study is due to the balance between the convection of energetic particles away from the Sun and the inward diffusion of energetic particles along magnetic field lines. However, there are also times of enhanced DV following geomagnetic disturbances caused by coronal mass ejections or corotating interaction regions. In this study we investigate changes in the DV over four solar cycles using ground-based neutron monitors at different magnetic latitudes and longitudes at Earth. We divide all of the hourly neutron monitor data into magnetic polarity cycles to investigate cycle-to-cycle variations in the phase and amplitude of the DV. The results show, in general, a similarity between each of the A<0 cycles and A>0 cycles, but with a phase change between the two. To investigate this further, we split the neutron monitor data by solar magnetic polarity between times when the dominant polarity was either directed outward (positive) or inward (negative) at the northern solar pole. We find that the maxima and minima of the DV changes by, typically, 1-2 h between the two polarity states for all non-polar neutron monitors. This difference between cycles becomes even larger in amplitude and phase with the removal of periods with enhanced DV caused by solar wind transients. The time difference between polarity cycles is found to vary in a 22-year cycle for both the maximum and minimum times of the DV. The times of the maximum and minimum in the DV do not always vary in the same manner between A>0 and A<0 polarity cycles, suggesting a slight change in the anisotropy vector of GCRs arriving at Earth between polarity cycles. Polar neutron monitors show differences in phase between polarity cycles which have asymptotic directions at mid-to-high latitudes. All neutron monitors show changes in the amplitude of the

  18. Assessing the Impacts of Decadal Socio-Agro-Hydro Climatic Variations on Agricultural Vulnerability over India (United States)

    Mohanty, M. P.; Sharma, T.; Ghosh, S.; Karmakar, S.


    Among both rice and wheat producing countries, India holds one of the major global shares in terms of production. However, with rising population, economic variability, and increasing food demand, it has become indispensable to strategically assess the food security of the nation, particularly under changing climatic conditions. This can be achieved by improving knowledge on the impacts of climate change on crop growth and yield through understanding the current status of agricultural vulnerability and quantifying its decadal changes. The present research focuses on assessing the observed decadal changes in agricultural vulnerability over India, at a district-scale. In the study, the deliberation of multiple climatic, hydrologic, agricultural indicators will majorly facilitate evaluating their direct/indirect influence on the crop production. In addition, a set of socio-economic indicators will also be considered to understand the attribution of these factors on the change in agricultural vulnerability. Here, these indicators will be integrated into a multivariate data envelopment analysis (DEA) framework to derive relative efficiency of each unit or district in crop production, which will be further transformed into a well-grounded agricultural vulnerability map. It has become essential to understand the influence of these indicators on agriculture, given that the extended periods of excessive/no rainfall or high/low temperature can alter the water cycle and hence cause stress on the agroecosystem. Likewise, change in the population density, main and marginal cultivators, main and marginal agriculture labours, improvement in management practices, or increase in power supply for agricultural use, can directly affect the food security of the region. Hence, this study will undoubtedly assist the decision-makers/strategists by highlighting the agriculturally vulnerable regions over India. Consequently, it will reassure the farmers to define bottom-up approaches in

  19. Inter-decadal variations in the linkages between ENSO, the IOD and south-eastern Australian springtime rainfall in the past 30 years (United States)

    Lim, Eun-Pa; Hendon, Harry H.; Zhao, Mei; Yin, Yonghong


    The 30 year period 1985-2014 experienced a swing of the Inter-decadal Pacific Oscillation (IPO) from the warm phase to the cold phase. Here we investigate variation of the relation between El Niño and the Southern Oscillation (ENSO) and the Indian Ocean Dipole mode (IOD) and resultant changes in the predictability of the IOD and south-eastern Australian (SEA) springtime rainfall associated with this swing in the IPO. Using observational analyses, we show that during the warm phase of the IPO in the 1980s-1990s, the amplitudes of ENSO and the IOD were large, and the correlation between them was high; thus predictability of the IOD was high. Nevertheless, during these decades SEA spring rainfall was only weakly related to ENSO and the IOD, and therefore predictability of SEA rainfall was low. In contrast, during the cold phase of the IPO in the 2000s, the opposite was found: the IOD occurred more independently from ENSO, so the IOD was less predictable. Nonetheless, SEA spring rainfall was more strongly related to ENSO and the IOD, and therefore, SEA rainfall was more predictable in the 2000s than in the 1980s-1990s. The cause of this decadal variation in the relationship of SEA rainfall with ENSO and the IOD between the recent warm and cold states of the IPO appears to be a systematic zonal variation of the rainfall anomalies in the tropical Indo-Pacific associated with the IOD and ENSO and related changes in the Rossby wave train path over Australia.

  20. Decadal-scale variations in geomagnetic field intensity from ancient slag mounds in Israel, Jordan, and Cyprus (United States)

    Shaar, Ron; Ben-Yosef, Erez; Tauxe, Lisa; Feinberg, Joshua M.; kassianidou, Vasiliky; Lorentzen, Brita; Levy, Thomas E.


    After decades of paleointensity research, it is still not fully understood how fast can field intensity change. Direct measurements of field intensity that go back to the 1830s show relatively small changes with rather smooth behavior over decadal timescales. In contrast, recent archaeomagnetic studies have revealed periods with significant intensity variations termed "archaeomagnetic jerks" (Gallet et al., 2003) and "spikes" (Ben-Yosef et al., 2009). This apparent inconsistency suggests that temporal variations of the geomagnetic field intensity over the past two centuries have been relatively small compared to earlier periods. To address this question we have investigated several ancient slag mounds in Jordan, Israel, and Cyprus. The mounds are multi-layered sequences of slag and charcoal that rapidly accumulated near ancient copper smelting sites as long as copper was produced in the nearby sites. The chronologies of the slag mounds were modeled using radiocarbon dates of short-lived material. Paleointensities were obtained using Thellier-type IZZI experiments with additional anisotropy, cooling rate, and non-linear TRM assessments. The overall data indicate that some periods are characterized with extremely high variation rate, while other periods seem quieter. In this presentation we review different aspects of our working methodology: field sampling, wood identification and radiocarbon analysis, age modeling, magnetic petrology, magnetic microscopy, and finally, paleointensity and data analysis. We present new recently published data from two Cypriot slag mounds, and discuss the overall archaeomagnetic findings in the context of high precision geomagnetic models of the past 170 years.

  1. Somatic Variation of T-Cell Receptor Genes Strongly Associate with HLA Class Restriction.

    Directory of Open Access Journals (Sweden)

    Paul L Klarenbeek

    Full Text Available Every person carries a vast repertoire of CD4+ T-helper cells and CD8+ cytotoxic T cells for a healthy immune system. Somatic VDJ recombination at genomic loci that encode the T-cell receptor (TCR is a key step during T-cell development, but how a single T cell commits to become either CD4+ or CD8+ is poorly understood. To evaluate the influence of TCR sequence variation on CD4+/CD8+ lineage commitment, we sequenced rearranged TCRs for both α and β chains in naïve T cells isolated from healthy donors and investigated gene segment usage and recombination patterns in CD4+ and CD8+ T-cell subsets. Our data demonstrate that most V and J gene segments are strongly biased in the naïve CD4+ and CD8+ subsets with some segments increasing the odds of being CD4+ (or CD8+ up to five-fold. These V and J gene associations are highly reproducible across individuals and independent of classical HLA genotype, explaining ~11% of the observed variance in the CD4+ vs. CD8+ propensity. In addition, we identified a strong independent association of the electrostatic charge of the complementarity determining region 3 (CDR3 in both α and β chains, where a positively charged CDR3 is associated with CD4+ lineage and a negatively charged CDR3 with CD8+ lineage. Our findings suggest that somatic variation in different parts of the TCR influences T-cell lineage commitment in a predominantly additive fashion. This notion can help delineate how certain structural features of the TCR-peptide-HLA complex influence thymic selection.

  2. Multi-decadal variation in size of juvenile Summer Flounder (Paralichthys dentatus) in Chesapeake Bay (United States)

    Nys, Lauren N.; Fabrizio, Mary C.; Tuckey, Troy D.


    During the last quarter-century, management of Summer Flounder Paralichthys dentatus along the Atlantic coast resulted in significant increases in abundance such that rebuilding targets were recently achieved. Although spawning stock biomass is high, recruitment of young-of-the-year (YOY) Summer Flounder remains variable. Chesapeake Bay is one of the principal nursery areas for this species, but processes such as growth and survival that affect production of YOY Summer Flounder in this estuary have not been explored. Here, we investigated the relationship between abundance and size of Summer Flounder recruits from the 1988 to 2012 year classes in Chesapeake Bay. We also considered the effects of environmental factors on fish size because conditions in the bay vary spatially during the time that fish occupy nursery areas. To describe variations in Summer Flounder size, we used monthly length observations from 13,018 YOY fish captured by bottom trawl from the lower Chesapeake Bay and the James, York, and Rappahannock river subestuaries where Summer Flounder are commonly observed. We applied a generalized additive model to describe spatial, temporal, and environmental effects on observed fish size; we also considered the density of Summer Flounder and an index of productivity as factors in the model. Summer Flounder in Chesapeake Bay exhibited density-dependent and spatially related variations in mean length: larger fish were found mostly in the Bay and smaller fish in the subestuaries. Additionally, low ( 26 °C) temperatures and low salinities (indicating that individuals found in these environments were typically smaller than conspecifics inhabiting areas of moderate temperatures and higher salinities. Variable nursery habitat conditions in temperate estuaries affect fish size and, subsequently, may influence production of Summer Flounder year classes through effects on maturation and survival. As water temperatures in the mid-Atlantic region continue to increase

  3. Finite-Temperature Variational Monte Carlo Method for Strongly Correlated Electron Systems (United States)

    Takai, Kensaku; Ido, Kota; Misawa, Takahiro; Yamaji, Youhei; Imada, Masatoshi


    A new computational method for finite-temperature properties of strongly correlated electrons is proposed by extending the variational Monte Carlo method originally developed for the ground state. The method is based on the path integral in the imaginary-time formulation, starting from the infinite-temperature state that is well approximated by a small number of certain random initial states. Lower temperatures are progressively reached by the imaginary-time evolution. The algorithm follows the framework of the quantum transfer matrix and finite-temperature Lanczos methods, but we extend them to treat much larger system sizes without the negative sign problem by optimizing the truncated Hilbert space on the basis of the time-dependent variational principle (TDVP). This optimization algorithm is equivalent to the stochastic reconfiguration (SR) method that has been frequently used for the ground state to optimally truncate the Hilbert space. The obtained finite-temperature states allow an interpretation based on the thermal pure quantum (TPQ) state instead of the conventional canonical-ensemble average. Our method is tested for the one- and two-dimensional Hubbard models and its accuracy and efficiency are demonstrated.

  4. Variational cluster approximation study of Mott transition with strong spin-orbit coupling

    International Nuclear Information System (INIS)

    Shirakawa, Tomonori; Watanabe, Hiroshi; Yunoki, Seiji


    Motivated by recent experiments on Sr 2 IrO 4 , the ground state magnetic and electronic structures are studied theoretically for a two-dimensional three-band Hubbard model with strong spin-orbit coupling. To treat spin-orbit coupling, local Coulomb interactions, and band structure effects on the same footing, the variational cluster approximation based on the self-energy functional theory is employed. It is found that for a relatively large coupling region, the ground state is an anisotropic antiferromagnetic Mott insulator of an effective local angular momentum J eff = 1/2 with xy plane as an easy plane. This anisotropy is caused by the strong spin-orbit coupling along with the inter-orbital Hund's coupling. The momentum resolved one-particle excitations are also studied for the Mott insulating phase. It is found that the low-energy one-particle excitations consist mostly of the J eff = 1/2 state, a direct evidence of a novel J eff = 1/2 Mott insulator.

  5. Spatial and Decadal Variations in Potential Evapotranspiration of China Based on Reanalysis Datasets during 1982–2010

    Directory of Open Access Journals (Sweden)

    Yunjun Yao


    Full Text Available Potential evapotranspiration (PET is an important indicator of atmospheric evaporation demand and has been widely used to characterize hydrological change. However, sparse observations of pan evaporation (EP prohibit the accurate characterization of the spatial and temporal patterns of PET over large spatial scales. In this study, we have estimated PET of China using the Penman-Monteith (PM method driven by gridded reanalysis datasets to analyze the spatial and decadal variations of PET in China during 1982–2010. The results show that the estimated PET has decreased on average by 3.3 mm per year (p < 0.05 over China during 1982–1993, while PET began to increase since 1994 by 3.4 mm per year (p < 0.05. The spatial pattern of the linear trend in PET of China illustrates that a widely significant increasing trend in PET appears during 1982–2010 in Northwest China, Central China, Northeast China and South China while there are no obvious variations of PET in other regions. Our findings illustrate that incident solar radiation (Rs is the largest contributor to the variation of PET in China, followed by vapor pressure deficit (VPD, air temperature (Tair and wind speed (WS. However, WS is the primary factor controlling inter-annual variation of PET over Northwest China.

  6. The relationship between thermocline depth and SST anomalies in the eastern equatorial Pacific: Seasonality and decadal variations (United States)

    Zhu, Jieshun; Kumar, Arun; Huang, Bohua


    Even though the vital role of thermocline fluctuation in El Niño-Southern Oscillation (ENSO) cycle has been established previously, the direct relationship between the thermocline depth and sea surface temperature (SST) anomalies in the equatorial Pacific is yet to be fully understood, especially its seasonality. Thermocline depth anomalies have been found to lead SST anomalies in time with a longitude-dependent delay, but our study also suggests that the relationship shows considerable seasonal dependency and is strongest (weakest) during the boreal spring (summer). Over the eastern equatorial Pacific where there is least delay (compared to that in the western and central Pacific), the connection between thermocline and SST is the weakest during the boreal spring. This feature may be one of causes for ENSO spring persistence barrier. Furthermore, the thermocline-SST connections exhibit significant decadal variations, which are remarkably consistent with the decadal changes in the persistence barrier of SST anomalies over the eastern Pacific. It is also found that the decadal shift in the timing of the thermocline-SST connection barrier is caused by the changes in the seasonal cycle of tropical trade winds and thermocline depths.

  7. Possible association of the western Tibetan Plateau snow cover with the decadal to interdecadal variations of northern China heatwave frequency

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhiwei [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China); Jiang, Zhihong; Zhong, Shanshan; Wang, Lijuan [Nanjing University of Information Science and Technology, Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing (China); Li, Jianping [Chinese Academy of Sciences, State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Beijing (China)


    Northern China has been subject to increased heatwave frequency (HWF) in recent decades, which deteriorates the local droughts and desertification. More than half a billion people face drinking water shortages and worsening ecological environment. In this study, the variability in the western Tibetan Plateau snow cover (TPSC) is observed to have an intimate linkage with the first empirical orthogonal function mode of the summer HWF across China. This distinct leading mode is dominated by the decadal to inter-decadal variability and features a mono-sign pattern with the extreme value center prevailing over northern China and high pressure anomalies at mid- and upper troposphere over Mongolia and the adjacent regions. A simplified general circulation model is utilized to examine the possible physical mechanism. A reduced TPSC anomaly can induce a positive geopotential height anomaly at the mid- and upper troposphere and subsequently enhance the climatological high pressure ridge over Mongolia and the adjacent regions. The subsidence associated with the high pressure anomalies tends to suppress the local cloud formation, which increases the net radiation budget, heats the surface, and favors more heatwaves. On the other hand, the surface heating can excite high pressure anomalies at mid- and upper troposphere. The latter further strengthens the upper troposphere high pressure anomalies over Mongolia and the adjacent regions. Through such positive feedback effect, the TPSC is tied to the interdecadal variations of the northern China HWF. (orig.)

  8. Decadal to millennial scale geomagnetic field variations in the Levantine archaeointensity curve (LAC): methodology and applications (United States)

    Shaar, Ron; Tauxe, Lisa; Ron, Hagai; Agnon, Amotz; Ben-Yosef, Erez; Finkelstein, Israel; Zuckerman, Sharon; Levy, Thomas E.


    ) according to the dating method employed (archaeological, historical, radiocarbon). In addition, we cross check results from multiple archaeological sites using different source materials dated using different methodologies. The results of this effort are summarized in a regional compilation namely Levantine Archaeomagnetic Curve - LAC. The initial version of the LAC includes recently published data from ancient copper production sites, and new data from two important biblical archaeological mounds in Israel - Tel Megiddo ("Armageddon") and Tel Hazor. In this talk we review our working methodologies, report the current status of the LAC, and discuss its implications on our understanding of geomagnetic secular variations.

  9. Limits on cosmological variation of strong interaction and quark masses from big bang nucleosynthesis, cosmic, laboratory and Oklo data

    International Nuclear Information System (INIS)

    Flambaum, V.V.; Shuryak, E.V.


    Recent data on the cosmological variation of the electromagnetic fine structure constant from distant quasar (QSO) absorption spectra have inspired a more general discussion of the possible variation of other constants. We discuss the variation of strong scale and quark masses. We derive limits on their relative change from (i) primordial big bang nucleosynthesis, (ii) the Oklo natural nuclear reactor, (iii) quasar absorption spectra, and (iv) laboratory measurements of hyperfine intervals

  10. Multi-Decadal to Millennial Scale Holocene Hydrologic Variation in the Southern Hemisphere Tropics of South America (United States)

    Ekdahl, E. J.; Fritz, S. C.; Baker, P. A.; Burns, S. J.; Coley, K.; Rigsby, C. A.


    Numerous sites in the Northern Hemisphere show multi-decadal to millennial scale climate variation during the Holocene, many of which have been correlated with changes in atmospheric radiocarbon production or with changes in North Atlantic oceanic circulation. The manifestation of such climate variability in the hydrology of the Southern Hemisphere tropics of South America is unclear, because of the limited number of records at suitably high resolution. In the Lake Titicaca drainage basin of Bolivia and Peru, high-resolution lacustrine records reveal the overall pattern of Holocene lake-level change, the influence of precessional forcing of the South American Summer Monsoon, and the effects of high-frequency climate variability in records of lake productivity and lake ecology. Precessional forcing of regional precipitation is evident in the Lake Titicaca basin as a massive (ca. 85 m) mid-Holocene decline in lake level beginning about 7800 cal yr BP and a subsequent rise in lake level after 4000 cal yr BP. Here we show that multi-decadal to millennial-scale climate variability, superimposed upon the envelope of change at orbital time scales, is similar in timing and pattern to the ice-rafted debris record of Holocene Bond events in the North Atlantic. A high-resolution carbon isotopic record from Lake Titicaca that spans the entire Holocene suggests that cold intervals of Holocene Bond events are periods of increased precipitation, thus indicating an anti-phasing of precipitation variation on the Altiplano relative to the Northern Hemisphere tropics. A similar pattern of variation is also evident in high-resolution (2-30 yr spacing) diatom and geochemical records that span the last 7000 yr from two smaller lakes, Lagos Umayo and Lagunillas, in the Lake Titicaca drainage basin.

  11. Impacts of decadal variations in natural emissions due to land-cover changes on ozone production in southern China

    Directory of Open Access Journals (Sweden)

    Mengmeng Li


    Full Text Available The decadal variations in emissions of high-reactivity biogenic volatile organics (BVOCs, as a result of land-cover changes, could significantly impact ozone (O3 production. In this study, the Weather Research and Forecasting/Chemistry (WRF/Chem modelling system, coupled with dynamic vegetation data sets derived from Moderate Resolution Imaging Spectroradiometer (MODIS, 2001–2012 and Advanced Very High Resolution Radiometer (AVHRR, early 1990s measurements, were used to investigate the impacts of land-cover changes on natural emissions, and consequently O3 production, in the Pearl River Delta (PRD region of southern China over the past two decades. Model results indicate that BVOC emissions were highly dependent on forest area. The total BVOC emissions in the modelling domain increased by a factor of two due to afforestation since the early 1990s, declined slowly (−5.8% yr−1 until 2006 and then increased continuously (+9.1% yr−1 to 2012. The decadal variations in BVOC emissions have complex implications for summer O3 production in PRD, depending on the chemical regimes and prevailing winds. The impacts on O3 production were most sensitive in downwind areas, and it was found that the large increase in BVOC emissions during 2006–2012 tended to reduce surface O3 concentrations by 1.6–2.5 ppb in rural regions, but caused an increment of O3 peaks by up to 2.0–6.0 ppb in VOC-limited urban areas (e.g., Guangzhou, Foshan and Zhongshan. The opposite was true in the period 2001–2006, when the reduced BVOC emissions resulted in 1.3–4.0 ppb increases in daytime O3 concentrations over northern rural regions. Impact of the two-fold increase in BVOC emissions since the early 1990s to 2006 was a 0.9–4.6 ppb increment in surface O3 concentrations over the downwind areas. This study suggests that the potential impacts on ozone chemistry should be considered in long-term land-use planning and air-quality management.

  12. Decadal Variation of the Number of El Nino Onsets and El Nino-Related Months and Estimating the Likelihood of El Nino Onset in a Warming World (United States)

    Wilson, Robert M.


    Examination of the decadal variation of the number of El Nino onsets and El Nino-related months for the interval 1950-2008 clearly shows that the variation is better explained as one expressing normal fluctuation and not one related to global warming. Comparison of the recurrence periods for El Nino onsets against event durations for moderate/strong El Nino events results in a statistically important relationship that allows for the possible prediction of the onset for the next anticipated El Nino event. Because the last known El Nino was a moderate event of short duration (6 months), having onset in August 2006, unless it is a statistical outlier, one expects the next onset of El Nino probably in the latter half of 2009, with peak following in November 2009-January 2010. If true, then initial early extended forecasts of frequencies of tropical cyclones for the 2009 North Atlantic basin hurricane season probably should be revised slightly downward from near average-to-above average numbers to near average-to-below average numbers of tropical cyclones in 2009, especially as compared to averages since 1995, the beginning of the current high-activity interval for tropical cyclone activity.

  13. Decadal and Seasonal Variations of Alpine Lakes in Glacierized areas of Central Asia during 1990-2015 (United States)

    Li, J.; Warner, T.; Chen, X.; Bao, A.


    Central Asia is one of the world's most vulnerable areas responding to global change. Glacier lakes in the alpine regions remain sensitive to climatic change and fluctuate with temperature and precipitation variations. Study shows that glaciers in Central Asia have retreated dramatically, leading to the expansion of the existing glacial lakes and the emergence of many new glacier lakes. The existence of these lakes increases the possibility of outburst flood during the ice melting season, which can bring a disaster to the downstream area. Mapping glacial lakes and monitoring their changes would improve our understanding of regional climate change and glacier-related hazards. Glacial lakes in Central Asia are mainly located at the Tianshan Mountains, the Altai Mountains, the Kunlun Mountains and the Pamirs with average elevation more than 1500 meters. Most of these lakes are supplied with the glaciers or snowmelt water during the summer seasons. Satellite remote sensing provides an efficient and objective tool to analyze the status and variations of glacial lakes. The increased availability of remote sensing sensors with appropriate spatial and temporal resolutions, broad coverage makes lake investigations more feasible and cost-effective. The paper intends to map glacier lake changes in glacierized alpine mountains with Landsat TM/ETM+ imagery. More than 600 scenes of Landsat images in circa 1990, circa 2000, circa 2010 and circa 2015 are used to map the decadal glacial lake changes over the Central Asia, and about 8 expanding glacial lakes are selected to map seasonal changes. Over 12000 glacial lakes were mapped in circa 1990, and in 2015, lake number are more than 16000, most of these new lakes are emerging in the last 10 years. The result shows that the number and area of the glacial lakes in the Altain Mountain remain stable, while the Tianshan Mountain have experienced expanding changes in the last two decades, and about a half number of lake areas are

  14. Decadal Variation of the Relationship between Western Pacific Subtropical High and Summer Heatwaves in East China Modulated by Pacific Decadal Oscillation (United States)

    Liu, Q.; Fu, C.; Zhou, T.


    This study investigates the relationship between Western Pacific Subtropical High (WPSH) and summer heatwaves over Eastern China in interannual scale during the period of 1959-2016. Based on surface daily maximum temperature of 654 monitoring stations over China and meteorological variables in reanalysis data, we calculate the number of heatwave days (NHD) (one heatwave day was defined as one day with its daily maximum temperature greater than 35 degrees centigrade) as well as WPSH index and then examine their interannual relationship. Although the high-NHD-related 850hPa horizontal wind structure was shared by that of high WPSH and decaying El Niño summer, a decadal oscillation emerges for the correlation between interannual WPSH and NHD after removing their interdecadal variability by Ensemble Empirical Mode Decomposition (EEMD) method. The correlation coefficient can reach up to as high as 0.69 and as low as 0.17 and assembles the Pacific Decadal Oscillation (PDO) pretty well. Compositing analysis demonstrates that unstable WPSH-NHD relationship is mainly attributed to the spatial structure distinction of WPSH and surface warming in the El Niño decaying summer of different PDO phases. In the El Niño decaying summer of positive PDO phases, remarkable enhanced warming over majority of Southeastern China matches well with the noticeable westward extension of WPSH, which seems to be forced by the cyclonic circulation anomaly over Japan. The warmer Pacific-Indian Ocean Warm Pool intensifies the Matsuno-Gill pattern over Maritime Continent, stimulating this cyclonic circulation anomaly via the northward propagation of Rossby wave. In the El Niño decaying summer of negative PDO phases, the cooler East China Sea enhances WPSH in North China and South China Sea, and thereby leads to a local cyclonic circulation anomaly over Eastern China, which would cause a large scope of cooling and out-of-phase WPSH-NHD relationship.

  15. Decadal-scale variations of sedimentary dinoflagellate cyst records from the Yellow Sea over the last 400 years (United States)

    Kim, So-Young; Roh, Youn Ho; Shin, Hyeon Ho; Huh, Sik; Kang, Sung-Ho; Lim, Dhongil


    In recent decades, the Yellow Sea has experienced severe environmental deterioration due to increasing input of anthropogenic pollutants and consequently accelerated eutrophication. Whilst there have been significant advances in documenting historical records of metal pollution in the Yellow Sea region, changes in phytoplankton community structures affected by eutrophication remain understudied. Here, we present a new record of dinoflagellate cyst-based signals in age-dated sediment cores from the Yellow Sea mud deposits to provide better insight into eutrophication history and identification of associated responses of the regional phytoplankton community. It is worthy of note that there were significant variations in abundances and community structures of dinoflagellate cysts in three historical stages in association with increasing anthropogenic activity over the last 400 years. Pervasive effects of human interference altering the Yellow Sea environments are recognized by: 1) an abrupt increase of organic matter, including the diatom-produced biogenic opal concentrations (∼1850); 2) a distinct shift in phytoplankton composition towards dinoflagellate dominance (∼1940), and 3) recent acceleration of dinoflagellate cyst accumulation (∼1990). Particularly in the central Yellow Sea shelf, the anomalously high deposition of dinoflagellate cysts (especially Alexandrium species) is suggested to be a potentially important source of inoculum cells serving as a seed population for localized and recurrent blooms in coastal areas around the Yellow Sea.

  16. Centennial- to decadal-scale monsoon precipitation variations in the upper Hanjiang River region, China over the past 6650 years (United States)

    Tan, Liangcheng; Cai, Yanjun; Cheng, Hai; Edwards, Lawrence R.; Gao, Yongli; Xu, Hai; Zhang, Haiwei; An, Zhisheng


    The upper Hanjiang River region is the recharge area of the middle route of South-to-North Water Transfer Project. The region is under construction of the Hanjiang-Weihe River Water Transfer Project in China. Monsoon precipitation variations in this region are critical to water resource and security of China. In this study, high-resolution monsoon precipitation variations were reconstructed in the upper Hanjiang River region over the past 6650 years from δ18O and δ13C records of four stalagmites in Xianglong cave. The long term increasing trend of stalagmite δ18O record since the middle Holocene is consistent with other speleothem records from monsoonal China. This trend follows the gradually decreasing Northern Hemisphere summer insolation, which indicates that solar insolation may control the orbital-scale East Asian summer monsoon (EASM) variations. Despite the declined EASM intensity since the middle Holocene, local precipitation may not have decreased remarkably, as revealed by the δ13C records. A series of centennial- to decadal-scale cyclicity was observed, with quasi-millennium-, quasi-century-, 57-, 36- and 22-year cycles by removing the long-term trend of stalagmite δ18O record. Increased monsoon precipitation during periods of 4390-3800 a BP, 3590-2960 a BP, 2050-1670 a BP and 1110-790 a BP had caused four super-floods in the upper reach of Hanjiang River. Dramatically dry climate existed in this region during the 5.0 ka and 2.8 ka events, coinciding with notable droughts in other regions of monsoonal China. Remarkably intensified and southward Westerly jet, together with weakened summer monsoon, may delay the onset of rainy seasons, resulting in synchronous decreasing of monsoon precipitation in China during the two events. During the 4.2 ka event and the Little Ice Age, the upper Hanjiang River region was wet, which was similar to the climate conditions in central and southern China, but was the opposite of drought observed in northern China. We

  17. Strongly correlated fermions in 2 D : Variational Monte Carlo study of magnetism and supraconductivity (United States)

    Giamarchi, Thierry; Lhuillier, Claire


    Variational Monte Carlo techniques have been used to investigate the nature of the fundamental state of the Hubbard's for repulsions in the range 4 < {U}/{t} < 10 and for dopings up to 0.4. Away from half filling the antiferromagnetic phase is to be unstable against the formation of diagonal domain walls. This phase with diagonal domain walls is at our knowled stabler phase actually exhibited, but the antiferromagnetic order may still be stabilized by a superconducting pairing.

  18. Pubertal onset in girls is strongly influenced by genetic variation affecting FSH action

    DEFF Research Database (Denmark)

    Hagen, Casper P; Sørensen, Kaspar; Aksglaede, Lise


    Age at pubertal onset varies substantially in healthy girls. Although genetic factors are responsible for more than half of the phenotypic variation, only a small part has been attributed to specific genetic polymorphisms identified so far. Follicle-stimulating hormone (FSH) stimulates ovarian...... follicle maturation and estradiol synthesis which is responsible for breast development. We assessed the effect of three polymorphisms influencing FSH action on age at breast deveopment in a population-based cohort of 964 healthy girls. Girls homozygous for FSHR -29AA (reduced FSH receptor expression...

  19. Immune gene expression in Bombus terrestris: signatures of infection despite strong variation among populations, colonies, and sister workers.

    Directory of Open Access Journals (Sweden)

    Franziska S Brunner

    Full Text Available Ecological immunology relies on variation in resistance to parasites. Colonies of the bumblebee Bombus terrestris vary in their susceptibility to the trypanosome gut parasite Crithidia bombi, which reduces colony fitness. To understand the possible origin of this variation in resistance we assayed the expression of 28 immunologically important genes in foraging workers. We deliberately included natural variation of the host "environment" by using bees from colonies collected in two locations and sampling active foraging workers that were not age controlled. Immune gene expression patterns in response to C. bombi showed remarkable variability even among genetically similar sisters. Nevertheless, expression varied with parasite exposure, among colonies and, perhaps surprisingly, strongly among populations (collection sites. While only the antimicrobial peptide abaecin is universally up regulated upon exposure, linear discriminant analysis suggests that the overall exposure effect is driven by a combination of several immune pathways and further immune functions such as ROS regulation. Also, the differences among colonies in their immune gene expression profiles provide clues to the mechanistic basis of well-known inter-colony variation in susceptibility to this parasite. Our results show that transcriptional responses to parasite exposure can be detected in ecologically heterogeneous groups despite strong background noise.

  20. Variational Monte Carlo calculations of lithium atom in strong magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Doma, S. B., E-mail: [Alexandria University, Mathematics Department, Faculty of Science (Egypt); Shaker, M. O.; Farag, A. M. [Tanta University, Mathematics Department, Faculty of Science (Egypt); El-Gammal, F. N., E-mail: [Menofia University, Mathematics Department, Faculty of Science (Egypt)


    The variational Monte Carlo method is applied to investigate the ground state and some excited states of the lithium atom and its ions up to Z = 10 in the presence of an external magnetic field regime with γ = 0–100 arb. units. The effect of increasing field strength on the ground state energy is studied and precise values for the crossover field strengths were obtained. Our calculations are based on using accurate forms of trial wave functions, which were put forward in calculating energies in the absence of magnetic field. Furthermore, the value of Y at which ground-state energy of the lithium atom approaches to zero was calculated. The obtained results are in good agreement with the most recent values and also with the exact values.

  1. The effect of regional variation of seismic wave attenuation on the strong ground motion from earthquakes

    International Nuclear Information System (INIS)

    Chung, D.H.; Bernreuter, D.L.


    Attenuation is caused by geometric spreading and absorption. Geometric spreading is almost independent of crustal geology and physiographic region, but absorption depends strongly on crustal geology and the state of the earth's upper mantle. Except for very high frequency waves, absorption does not affect ground motion at distances less than about 25 to 50 km. Thus, in the near-field zone, the attenuation in the eastern United States is similar to that in the western United States. Beyond the near field, differences in ground motion can best be accounted for by differences in attenuation caused by differences in absorption. The stress drop of eastern earthquakes may be higher than for western earthquakes of the same seismic moment, which would affect the high-frequency spectral content. But we believe this factor is of much less significance than differences in absorption in explaining the differences in ground motion between the East and the West. The characteristics of strong ground motion in the conterminous United States are discussed in light of these considerations, and estimates are made of the epicentral ground motions in the central and eastern United States. (author)

  2. A simple model for variations in global mean temperature: implications for decadal variability, the global warming hiatus, and recent temperature rise (United States)

    Hu, S.; Fedorov, A. V.


    Global mean surface temperature (GMST) has steadily risen since the mid-19th century, and at the same time experienced significant variations on interannual and decadal timescales. Various mechanisms have been proposed to explain such variations, ranging from the Pacific decadal oscillation to volcanic eruptions. In this study, we construct a simple, physically-based model of GMST variations that incorporates greenhouse gas emissions, ENSO forcing, and stratospheric sulfate aerosols. The model closely reproduces the history of GMST changes since 1880 with the mean squared error about 0.05°C for the past 60 years, smaller than the typical error of GMST observations (see the figure attached). It also accurately captures decadal GMST variations, including the global warming hiatus in the early 21stcentury. This model can be used to understand the causes of the observed GMST variations and requires little computational resource. Our results confirm that weak El Niño activity was the major cause of the recent global warming hiatus, while the rapid temperature rise since 2014 is due to atmospheric heat release during 2014-2016 El Niño conditions in addition to the continuing background global warming trend. The model can be also used to make predictions for next-year GMST in the short term, and future climate projections in the long term. We will also discuss the implications of this simple model for paleoclimate reconstructions and GCM performance evaluations.

  3. Glucose Variations and Activity Are Strongly Coupled in Sleep and Wake in Young Adults With Type 1 Diabetes. (United States)

    Farabi, Sarah S; Carley, David W; Quinn, Lauretta


    Glucose variations are common throughout sleep and wakefulness in people with type 1 diabetes mellitus (T1DM). The objective of this investigation was to characterize the time-varying coupling between glucose and unstructured physical activity over a 60-hr period in young adults with T1DM. The hypothesis was that coupling would differ during sleep versus wakefulness and would exhibit circadian variations. Young adults with T1DM treated with an insulin pump participated in the study. Glucose variations were monitored with a continuous glucose monitoring system, and activity was assessed using an activity-monitoring band worn on the nondominant wrist. Simultaneous glucose and physical activity data across a continuous 60-hr period were used for analysis. Wavelet coherence analysis was employed to quantify the coupling between physical activity and glucose. Cosinor analysis was used to assess whether glucose/activity coherence exhibited significant circadian variations. Participants comprised 23 adults, aged 18-30 years, with T1DM. Coherence analysis demonstrated substantial coupling between physical activity and glucose variations during both wakefulness and sleep. For rapid (10-30 min) fluctuations, mean coherence was higher during sleep than wakefulness ( F = 10.86, p = .003). Rapid glucose variations consistently led to changes in activity ( p = .001) during sleep but not during wake. Cosinor analysis revealed significant circadian modulation of glucose/activity coupling, especially for fluctuation periods 2-4 hr. Unstructured physical activity and glucose variations demonstrated strong time- and frequency-dependent coupling over a 60-hr period in young adults with T1DM, with sleep/wake differences and circadian modulation evident in this relationship.

  4. Variation in Rural African Gut Microbiota Is Strongly Correlated with Colonization by Entamoeba and Subsistence (United States)

    Morton, Elise R.; Lynch, Joshua; Froment, Alain; Lafosse, Sophie; Heyer, Evelyne; Przeworski, Molly; Blekhman, Ran; Ségurel, Laure


    The human gut microbiota is impacted by host nutrition and health status and therefore represents a potentially adaptive phenotype influenced by metabolic and immune constraints. Previous studies contrasting rural populations in developing countries to urban industrialized ones have shown that industrialization is strongly correlated with patterns in human gut microbiota; however, we know little about the relative contribution of factors such as climate, diet, medicine, hygiene practices, host genetics, and parasitism. Here, we focus on fine-scale comparisons of African rural populations in order to (i) contrast the gut microbiota of populations inhabiting similar environments but having different traditional subsistence modes and either shared or distinct genetic ancestry, and (ii) examine the relationship between gut parasites and bacterial communities. Characterizing the fecal microbiota of Pygmy hunter-gatherers as well as Bantu individuals from both farming and fishing populations in Southwest Cameroon, we found that the gut parasite Entamoeba is significantly correlated with microbiome composition and diversity. We show that across populations, colonization by this protozoa can be predicted with 79% accuracy based on the composition of an individual's gut microbiota, and that several of the taxa most important for distinguishing Entamoeba absence or presence are signature taxa for autoimmune disorders. We also found gut communities to vary significantly with subsistence mode, notably with some taxa previously shown to be enriched in other hunter-gatherers groups (in Tanzania and Peru) also discriminating hunter-gatherers from neighboring farming or fishing populations in Cameroon. PMID:26619199

  5. Variation in Rural African Gut Microbiota Is Strongly Correlated with Colonization by Entamoeba and Subsistence. (United States)

    Morton, Elise R; Lynch, Joshua; Froment, Alain; Lafosse, Sophie; Heyer, Evelyne; Przeworski, Molly; Blekhman, Ran; Ségurel, Laure


    The human gut microbiota is impacted by host nutrition and health status and therefore represents a potentially adaptive phenotype influenced by metabolic and immune constraints. Previous studies contrasting rural populations in developing countries to urban industrialized ones have shown that industrialization is strongly correlated with patterns in human gut microbiota; however, we know little about the relative contribution of factors such as climate, diet, medicine, hygiene practices, host genetics, and parasitism. Here, we focus on fine-scale comparisons of African rural populations in order to (i) contrast the gut microbiota of populations inhabiting similar environments but having different traditional subsistence modes and either shared or distinct genetic ancestry, and (ii) examine the relationship between gut parasites and bacterial communities. Characterizing the fecal microbiota of Pygmy hunter-gatherers as well as Bantu individuals from both farming and fishing populations in Southwest Cameroon, we found that the gut parasite Entamoeba is significantly correlated with microbiome composition and diversity. We show that across populations, colonization by this protozoa can be predicted with 79% accuracy based on the composition of an individual's gut microbiota, and that several of the taxa most important for distinguishing Entamoeba absence or presence are signature taxa for autoimmune disorders. We also found gut communities to vary significantly with subsistence mode, notably with some taxa previously shown to be enriched in other hunter-gatherers groups (in Tanzania and Peru) also discriminating hunter-gatherers from neighboring farming or fishing populations in Cameroon.

  6. Strong phylogenetic effects on floral scent variation of oil-secreting orchids in South Africa. (United States)

    Steiner, Kim E; Kaiser, Roman; Dötterl, Stefan


    Evolution involves the interplay between natural selection and phylogenetic constraint. This is particularly evident among the flowering plants where form and diversity of flowers attest to the importance of both pollinator-mediated selection and phylogenetic constraint. Although this has been studied mostly using visible floral characters, invisible volatile chemicals emitted by the flowers should be subject to these same evolutionary forces. Unfortunately, most analyses of floral volatiles have over-emphasized the importance of natural selection and underplayed phylogenetic constraint without quantifying their respective roles in the evolution and composition of floral scents. We used multivariate analyses to test the relative importance of pollinators vs. phylogeny in determining the composition of floral scents among oil-secreting orchids in southern Africa. Floral scents of 42 oil-secreting taxa/ecotypes distributed among 12 subclades in the tribe Diseae were sampled using headspace adsorption and gas chromatography-mass spectroscopy. We identified 257 scent compounds distributed over nine different compound classes, with the majority of scents dominated by aliphatic or benzenoid compounds. The only significant predictor of floral scent among these orchids above the species level was phylogeny. Nevertheless, in two of the clades there were differences in scent profiles at the species and ecotype level that corresponded to different pollinators and were thus suggestive of pollinator-mediated selection. Scent variation was greater than expected and phylogeny was more important than pollinator-mediated selection in predicting the composition of floral scents of oil-secreting orchids, despite the specialized nature of the pollinator reward system.

  7. Increase in winter haze over eastern China in recent decades: Roles of variations in meteorological parameters and anthropogenic emissions: INCREASE IN WINTER HAZE IN EASTERN CHINA

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA; Liao, Hong [School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing China; Joint International Research Laboratory of Climate and Environment Change, Nanjing University of Information Science and Technology, Nanjing China; Lou, Sijia [Atmospheric Science and Global Change Division, Pacific Northwest National Laboratory, Richland Washington USA


    The increase in winter haze over eastern China in recent decades due to variations in meteorological parameters and anthropogenic emissions was quantified using observed atmospheric visibility from the National Climatic Data Center Global Summary of Day database for 1980–2014 and simulated PM2.5 concentrations for 1985–2005 from the Goddard Earth Observing System (GEOS) chemical transport model (GEOS-Chem). Observed winter haze days averaged over eastern China (105–122.5°E, 20–45°N) increased from 21 d in 1980 to 42 d in 2014, and from 22 to 30 d between 1985 and 2005. The GEOS-Chem model captured the increasing trend of winter PM2.5 concentrations for 1985–2005, with concentrations averaged over eastern China increasing from 16.1 μg m-3 in 1985 to 38.4 μg m-3 in 2005. Considering variations in both anthropogenic emissions and meteorological parameters, the model simulated an increase in winter surface-layer PM2.5 concentrations of 10.5 (±6.2) μg m-3 decade-1 over eastern China. The increasing trend was only 1.8 (±1.5) μg m-3 decade-1 when variations in meteorological parameters alone were considered. Among the meteorological parameters, the weakening of winds by -0.09 m s-1 decade-1 over 1985–2005 was found to be the dominant factor leading to the decadal increase in winter aerosol concentrations and haze days over eastern China during recent decades.

  8. The Role of Meteorology and Surface Condition to Multi-Decadal Variations of Dust Emission in Sahara and Sahel (United States)

    Kim, D.; Chin, M.; Diehl, T. L.; Bian, H.; Brown, M. E.; Remer, L. A.; Stockwell, W. R.


    North Africa is the world's largest dust source region influencing regional and global climate, human health, and even the local economy. However North Africa as a dust source is not uniform but it consists of the arid region (Sahara) and the semi-arid region (Sahel) with emission rates depending on meteorological and surface conditions. Several recent studies have shown that dust from North Africa seems to have a decreasing trend in the past three decades. The goal of this study is to better understand the controlling factors that determine the change of dust in North Africa using observational data and model simulations. First we analyze surface bareness conditions determined from a long-term satellite observed Normalized Difference Vegetation Index for 1980-2008. Then we examine the key meteorological variables of precipitation and surface winds. Modeling experiments were conducted using the NASA Goddard Chemistry Aerosol Radiation and Transport (GOCART) model, which has been recently updated with a dynamic dust source function. Using the method we separate the dust originating from the Sahel from that of the Sahara desert. We find that the surface wind speed is the most dominant factor affecting Sahelian dust emission while vegetation has a modulating effect. We will show regional differences in meteorological variables, surface conditions, dust emission, and dust distribution and address the relationships among meteorology, surface conditions, and dust emission/loading in the past three decades (1980-2008).

  9. Strong localized variations of the low-altitude energetic electron fluxes in the evening sector near the plasmapause

    Directory of Open Access Journals (Sweden)

    E. E. Titova


    Full Text Available Specific type of energetic electron precipitation accompanied by a sharp increase in trapped energetic electron flux are found in the data obtained from low-altitude NOAA satellites. These strongly localized variations of the trapped and precipitated energetic electron flux have been observed in the evening sector near the plasmapause during recovery phase of magnetic storms. Statistical characteristics of these structures as well as the results of comparison with proton precipitation are described. We demonstrate the spatial coincidence of localized electron precipitation with cold plasma gradient and whistler wave intensification measured on board the DE-1 and Aureol-3 satellites. A simultaneous localized sharp increase in both trapped and precipitating electron flux could be a result of significant pitch-angle isotropization of drifting electrons due to their interaction via cyclotron instability with the region of sharp increase in background plasma density.Key words. Ionosphere (particle precipitation; wave-particle interaction Magnetospheric Physics (plasmasphere

  10. Variation of the critical slab thickness with the degree of strongly anisotropic scattering in one-speed neutron transport theory

    International Nuclear Information System (INIS)

    Yildiz, C.


    The critical slab problem is studied in one-speed neutron transport theory using a linearly anisotropic kernel which combines forward and backward scattering. It is shown that, the recently observed non-monotonic variation of the thickness also exists in this strongly anisotropic case. In addition, the influence of the linear anisotropy on the critical thickness is analysed in detail. Numerical analysis for the critical thickness are performed using the spherical harmonics method and results are tabulated for selected illustrative cases as a function of different degrees of anisotropic scattering. Finally, some results are discussed and compared with those already obtained by other methods, the agreement is satisfactory. The spherical harmonic method gives generally accurate results in one dimensional geometry, and it is very suitable for the numerical solution of the neutron transport equation with linearly anisotropic scattering

  11. Lake transparency: a window into decadal variations in dissolved organic carbon concentrations in Lakes of Acadia National Park, Maine (United States)

    Roesler, Collin S.; Culbertson, Charles W.


    A forty year time series of Secchi depth observations from approximately 25 lakes in Acadia National Park, Maine, USA, evidences large variations in transparency between lakes but relatively little seasonal cycle within lakes. However, there are coherent patterns over the time series, suggesting large scale processes are responsible. It has been suggested that variations in colored dissolved organic matter (CDOM) are primarily responsible for the variations in transparency, both between lakes and over time and further that CDOM is a robust optical proxy for dissolved organic carbon (DOC). Here we present a forward model of Secchi depth as a function of DOC based upon first principles and bio-optical relationships. Inverting the model to estimate DOC concentration from Secchi depth observations compared well with the measured DOC concentrations collected since 1995 (RMS error < 1.3 mg C l-1). This inverse model allows the time series of DOC to be extended back to the mid 1970s when only Secchi depth observations were collected, and thus provides a means for investigating lake response to climate forcing, changing atmospheric chemistry and watershed characteristics, including land cover and land use.

  12. Effects of strong earthquakes in variations of electrical and meteorological parameters of the near-surface atmosphere in Kamchatka region (United States)

    Smirnov, S. E.; Mikhailova, G. A.; Mikhailov, Yu. M.; Kapustina, O. V.


    The diurnal variations in electrical (quasistatic electric field and electrical conductivity) and meteorological (temperature, pressure, relative humidity of the atmosphere, and wind speed) parameters, measured simultaneously before strong earthquakes in Kamchatka region (November 15, 2006, M = 8.3; January 13, 2007, M = 8.1; January 30, 2016, M = 7.2), are studied for the first time in detail. It is found that a successively anomalous increase in temperature, despite the negative regular trend in these winter months, was observed in the period of six-seven days before the occurrences of earthquakes. An anomalous temperature increase led to the formation of "winter thunderstorm" conditions in the near-surface atmosphere of Kamchatka region, which was manifested in the appearance of an anomalous, type 2 electrical signal, the amplification of and intensive variations in electrical conductivity, heavy precipitation (snow showers), high relative humidity of air, storm winds, and pressure changes. With the weak flow of natural heat radiation in this season, the observed dynamics of electric and meteorological processes can likely be explained by the appearance of an additional heat source of seismic nature.

  13. Role of Surface Wind and Vegetation Cover in Multi-decadal Variations of Dust Emission in the Sahara and Sahel (United States)

    Kim, Dong; Chin, Mian; Remer, Lorraine A.; Diehl, Thomas L.; Bian, Huisheng; Yu, Hongbin; Brown, Molly E.; Stockwell, William R.


    North Africa, the world's largest dust source, is non-uniform, consisting of a permanently arid region (Sahara), a semi-arid region (Sahel), and a relatively moist vegetated region (Savanna), each with very different rainfall patterns and surface conditions. This study aims to better understand the controlling factors that determine the variation of dust emission in North Africa over a 27-year period from 1982 to 2008, using observational data and model simulations. The results show that the model-derived Saharan dust emission is only correlated with the 10-m winds (W10m) obtained from reanalysis data, but the model-derived Sahel dust emission is correlated with both W10m and the Normalized Difference Vegetation Index (NDVI) that is obtained from satellite. While the Saharan dust accounts for 82 of the continental North Africa dust emission (1340-1570 Tg year(exp -1) in the 27-year average, the Sahel accounts for 17 with a larger seasonal and inter-annual variation (230-380 Tg year(exp -1), contributing about a quarter of the transatlantic dust transported to the northern part of South America. The decreasing dust emission trend over the 27-year period is highly correlated with W10m over the Sahara (R equals 0.92). Over the Sahel, the dust emission is correlated with W10m (R 0.69) but is also anti-correlated with the trend of NDVI (R equals 0.65). W10m is decreasing over both the Sahara and the Sahel between 1982 and 2008, and the trends are correlated (R equals 0.53), suggesting that Saharan Sahelian surface winds are a coupled system, driving the inter-annual variation of dust emission.

  14. Strong H I Lyman-α variations from an 11 Gyr-old host star: a planetary origin? (United States)

    Bourrier, V.; Ehrenreich, D.; Allart, R.; Wyttenbach, A.; Semaan, T.; Astudillo-Defru, N.; Gracia-Berná, A.; Lovis, C.; Pepe, F.; Thomas, N.; Udry, S.


    Kepler-444 provides a unique opportunity to probe the atmospheric composition and evolution of a compact system of exoplanets smaller than the Earth. Five planets transit this bright K star at close orbital distances, but they are too small for their putative lower atmosphere to be probed at optical/infrared wavelengths. We used the Space Telescope Imaging Spectrograph instrument on board the Hubble Space Telescope to search for the signature of the planet's upper atmospheres at six independent epochs in the Lyman-α line. We detect significant flux variations during the transits of both Kepler-444 e and f ( 20%), and also at a time when none of the known planets was transiting ( 40%). Variability in the transition region and corona of the host star might be the source of these variations. Yet, their amplitude over short timescales ( 2-3 h) is surprisingly strong for this old (11.2 ± 1.0 Gyr) and apparently quiet main-sequence star. Alternatively, we show that the in-transit variations could be explained by absorption from neutral hydrogen exospheres trailing the two outer planets (Kepler-444 e and f). They would have to contain substantial amounts of water to replenish hydrogen exospheres such as these, which would reveal them to be the first confirmed ocean planets. The out-of-transit variations, however, would require the presence of an as-yet-undetected Kepler-444 g at larger orbital distance, casting doubt on the planetary origin scenario. Using HARPS-N observations in the sodium doublet, we derived the properties of two interstellar medium clouds along the line of sight toward Kepler-444. This allowed us to reconstruct the stellar Lyman-α line profile and to estimate the extreme-UV (XUV) irradiation from the star, which would still allow for a moderate mass loss from the outer planets after 11.2 Gyr. Follow-up of the system at XUV wavelengths will be required to assess this tantalizing possibility.

  15. Decadal Variations of the Western Subarctic Gyre and Main Pycnocline Depth due to Wind Stress Change in the Northern North Pacific (United States)

    Nagano, A.; Wakita, M.


    From the late 1990s to the early 2000s, the western subarctic gyre of the North Pacific, a cyclonic circulation in the western subarctic region, shrank northward associated with a decadal increase of sea surface height (SSH). This gyre change displaced the main pycnocline (halocline) downward and is expected to contribute to the deepening of the overlying temperature minimum layer. This is considered to affect the biogeochemical conditions in the western subarctic region, where is known as substantially slow ocean acidification region. In this study, on the basis of wind stress field data in the subpolar region (40˚N—54˚N, 160˚E—135˚W) during 1979—2014 provided by U.S. National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis, we estimated the variation in SSH, solving the vorticity gradient equation on the beta plane. Decadal increase in SSH at Station K2 (47˚N, 160˚E), representative point of the western subarctic region, was well produced by the calculation, and the correlation coefficient with altimetric SSH exceeds 0.6. The calculated SSH variation consists of the variations due to the barotropic and baroclinic Rossby wave modes. The gyre shrinkage is found to be caused primarily by the barotropic response to the wind change in the whole subpolar region and secondary by the first baroclinic response. Meanwhile, the decadal deepening of the main pycnocline at K2 is attributed to the baroclinic responses of the higher (second, third, and fourth) vertical modes to the local wind change.

  16. Seasonal to Decadal Variations of Water Vapor in the Tropical Lower Stratosphere Observed with Balloon-Borne Cryogenic Frost Point Hygrometers (United States)

    Fujiwara, M.; Voemel, H.; Hasebe, F.; Shiotani, M.; Ogino, S.-Y.; Iwasaki, S.; Nishi, N.; Shibata, T.; Shimizu, K.; Nishimoto, E.; hide


    We investigated water vapor variations in the tropical lower stratosphere on seasonal, quasi-biennial oscillation (QBO), and decadal time scales using balloon-borne cryogenic frost point hygrometer data taken between 1993 and 2009 during various campaigns including the Central Equatorial Pacific Experiment (March 1993), campaigns once or twice annually during the Soundings of Ozone and Water in the Equatorial Region (SOWER) project in the eastern Pacific (1998-2003) and in the western Pacific and Southeast Asia (2001-2009), and the Ticosonde campaigns and regular sounding at Costa Rica (2005-2009). Quasi-regular sounding data taken at Costa Rica clearly show the tape recorder signal. The observed ascent rates agree well with the ones from the Halogen Occultation Experiment (HALOE) satellite sensor. Average profiles from the recent five SOWER campaigns in the equatorial western, Pacific in northern winter and from the three Ticosonde campaigns at Costa Rica (10degN) in northern summer clearly show two effects of the QBO. One is the vertical displacement of water vapor profiles associated with the QBO meridional circulation anomalies, and the other is the concentration variations associated with the QBO tropopause temperature variations. Time series of cryogenic frost point hygrometer data averaged in a lower stratospheric layer together with HALOE and Aura Microwave Limb Sounder data show the existence of decadal variations: The mixing ratios were higher and increasing in the 1990s, lower in the early 2000s, and probably slightly higher again or recovering after 2004. Thus linear trend analysis is not appropriate to investigate the behavior of the tropical lower stratospheric water vapor.

  17. Temporal variations of groundwater tables and implications for submarine groundwater discharge: a 3-decade case study in central Japan (United States)

    Zhang, Bing; Zhang, Jing; Yoshida, Takafumi


    Fresh submarine groundwater discharge (SGD) is the key pathway of flux and nutrients for the groundwater from land to the ocean. SGD flux is a current issue of discussion and a means to clarify the coastal marine system under climate change. SGD flux accounts for about one-quarter of the river runoff in the Katakai alluvial fan in Uozu, Toyama, Japan, which is an ideal area to study SGD flux considering the need for a rapid response to climate change and the prior research on SGD there. In this paper, the monthly groundwater table's condition over 30 years is analyzed using monthly rainfall, snowfall, and the climate change index. Rainfall has been on an upward trend, but the snowfall has decreased over 40 years. Furthermore, the groundwater table at monitoring wells in the coastal area increased, as a result of the increased rainfall. However, the relationship between snowfall and groundwater is negative. As expected by Darcy's law, SGD flux was controlled by the hydraulic gradient of the coastal groundwater. The estimated historic SGD flux by groundwater table variation shows an upward trend of SGD. Considering the increase in precipitation and the groundwater table, SGD flux may increase under climate change.

  18. Distributions of Heavy Metals and Their Variations over the Past Three Decades in the Bohai Sea of China (United States)

    Yin, P.; Gao, F.


    In this paper, status of metal contamination in Bohai Sea was assessed by a comprehensive review of metal concentrations recorded in sediments. The average concentrations in the samples collected in recent years (summarized 3171 samples) were 0.31, 87.0, 25.7, 25.8, 0.11, 16.9, 52.2 and 27.7μg/g for Cd, Zn, Cu, Pb, Hg, As, Cr and Ni, respectively. In the samples collected in the 1980s, the concentrations were 22.6μg/g for Cu, 21.3μg/g for Pb, 69.13μg/g for Zn, 0.26μg/g for Cd and 57.5μg/g for Cr (summarized 218 samples). The concentrations of Cu, Pb, Zn and Cd in the samples collected in recent years were higher than in the samples collected in the 1980s (p˜0.05). The inputs of heavy metals from the land through rivers inputs, coastal urbanization and coastal industrial activities in recent years were higher than 1980s. The distribution patterns of heavy metals were significantly different between samples collected in recent 10 years and those in 1980s. In the 1980s, higher concentrations of Zn, Cd and Pb were measured in the samples collected from Bohai Bay. However, in recent years, higher concentrations of Zn, Cd and Pb were measured in the samples collected from the Liaodong Bay. This indicated that the sources of heavy metals in the Bohai-Rim region were changed significantly during the past decades. This is due to the changes of coastal activities and the inputs from the rivers discharges. The water and sediments discharges from the rivers flow into the Bohai Bay, such as the Haihe River and Luanhe River, have dramatically decreased since the 1980's due to the water diversion in the upper stream and almost reached the point of drying out in the estuaries. While in the Liaodong Bay, the Liaohe River and its tributaries are still steadily brought water and sediment discharges into the coast and offshore area and increased the inputs of heavy metals from the upper stream mining industries and urbanization in the drainage areas.

  19. The impacts of two types of El Niño on global ozone variations in the last three decades (United States)

    Xie, Fei; Li, Jianping; Tian, Wenshou; Zhang, Jiankai; Shu, Jianchuan


    The effects of El Niño Modoki events on global ozone concentrations are investigated from 1980 to 2010 El Niño Modoki events cause a stronger Brewer-Dobson (BD) circulation which can transports more ozone-poor air from the troposphere to stratosphere, leading to a decrease of ozone in the lower-middle stratosphere from 90°S to 90°N. These changes in ozone concentrations reduce stratospheric column ozone. The reduction in stratospheric column ozone during El Niño Modoki events is more pronounced over the tropical eastern Pacific than over other tropical areas because transport of ozone-poor air from middle-high latitudes in both hemispheres to low latitudes is the strongest between 60°W and 120°W. Because of the decrease in stratospheric column ozone during El Niño Modoki events more UV radiation reaches the tropical troposphere leading to significant increases in tropospheric column ozone An empirical orthogonal function (EOF) analysis of the time series from 1980 to 2010 of stratospheric and tropospheric ozone monthly anomalies reveals that: El Niño Modoki events are associated with the primary EOF modes of both time series. We also found that El Niño Modoki events can affect global ozone more significantly than canonical El Niño events. These results imply that El Niño Modoki is a key contributor to variations in global ozone from 1980 to 2010.

  20. Comparison of simultaneous variations of the ionospheric total electron content and geomagnetic field associated with strong earthquakes

    Directory of Open Access Journals (Sweden)

    Sh. Naaman


    Full Text Available In this paper, perturbations of the ionospheric Total Electron Content (TEC are compared with geomagnetic oscillations. Comparison is made for a few selected periods, some during earthquakes in California and Japan and others at quiet periods in Israel and California. Anomalies in TEC were extracted using Global Positioning System (GPS observations collected by GIL (GPS in Israel and the California permanent GPS networks. Geomagnetic data were collected in some regions where geomagnetic observatories and the GPS network overlaps. Sensitivity of the GPS method and basic wave characteristics of the ionospheric TEC perturbations are discussed. We study temporal variations of ionospheric TEC structures with highest reasonable spatial resolution around 50 km. Our results show no detectable TEC disturbances caused by right-lateral strike-slip earthquakes with minor vertical displacement. However, geomagnetic observations obtained at two observatories located in the epicenter zone of a strong dip-slip earthquake (Kyuchu, M = 6.2, 26 March 1997 revealed geomagnetic disturbances occurred 6–7 h before the earthquake.

  1. Spatial and decadal variations in satellite-based terrestrial evapotranspiration and drought over Inner Mongolia Autonomous Region of China during 1982-2009 (United States)

    Zhang, Zhaolu; Kang, Hui; Yao, Yunjun; Fadhil, Ayad M.; Zhang, Yuhu; Jia, Kun


    Evapotranspiration ( ET) plays an important role in exchange of water budget and carbon cycles over the Inner Mongolia autonomous region of China (IMARC). However, the spatial and decadal variations in terrestrial ET and drought over the IMARC in the past was calculated by only using sparse meteorological point-based data which remain quite uncertain. In this study, by combining satellite and meteorology datasets, a satellite-based semi-empirical Penman ET (SEMI-PM) algorithm is used to estimate regional ET and evaporative wet index (EWI) calculated by the ratio of ET and potential ET ( PET) over the IMARC. Validation result shows that the square of the correlation coefficients (R2) for the four sites varies from 0.45 to 0.84 and the root-mean-square error (RMSE) is 0.78 mm. We found that the ET has decreased on an average of 4.8 mm per decade (p=0.10) over the entire IMARC during 1982-2009 and the EWI has decreased on an average of 1.1% per decade (p=0.08) during the study period. Importantly, the patterns of monthly EWI anomalies have a good spatial and temporal correlation with the Palmer Drought Severity Index (PDSI) anomalies from 1982 to 2009, indicating EWI can be used to monitor regional surface drought with high spatial resolution. In high-latitude ecosystems of northeast region of the IMARC, both air temperature (Ta) and incident solar radiation (Rs) are the most important parameters in determining ET. However, in semiarid and arid areas of the central and southwest regions of the IMARC, both relative humidity (RH) and normalized difference vegetation index (NDVI) are the most important factors controlling annual variation of ET.

  2. The effect of long-term and decadal climate and hydrology variations on estuarine marsh dynamics: An identifying case study from the Río de la Plata (United States)

    Schuerch, M.; Scholten, J.; Carretero, S.; García-Rodríguez, F.; Kumbier, K.; Baechtiger, M.; Liebetrau, V.


    The vertical growth of coastal wetlands is known to primarily be controlled by local tidal range and sediment availability as well as the occurrence of storm events. In estuaries, sediment availability additionally depends on riverine sediment input, the effect of which may be more pronounced in some parts of the estuary, thereby introducing a distinct spatial pattern that depends on the estuary's shape as well as the riverine sediment input and the hydro-meteorological regime. In the present study, we investigate how estuarine marshes along the whole Río de la Plata (RdlP) are affected by decadal and long-term variations in river discharge and storm activity. The El Niño Southern Oscillation (ENSO), in this context, appears to introduce a pronounced decadal variability on sediment loads brought into the RdlP. Based on 15 sediment cores, recovered along the RdlP and adjacent Atlantic coast, vertical marsh growth rates were studied using radionuclide dating (210Pb and 137Cs) and grain size distributions. By comparing these sedimentological records with historic river discharge and storm surge data, we spatially interpret the relative importance of temporal variations in river discharge and storm activity on estuarine marsh growth. By delivering the first estimates for vertical growth rates of the RdlP marshes, we conclude that with average vertical marsh growth rates between 0.4 and 2.6 cm year- 1, the RdlP marshes are highly resilient against drowning under present and future sea-level rise (SLR) conditions. Furthermore, our results confirm a large spatial variability of the drivers for vertical marsh growth; extreme storm surges appear to play a role in the development of the outer RdlP marshes whereas the temporal variations in river discharge seem to be hierarchically more important for the marshes in the inner estuary.

  3. Corrigendum to "Decadal to millennial variations in water column parameters in pelagic marine environments of the Western Tethys (Carpathian realm) during Middle-Late Jurassic - Evidence from the radiolarian record" [Glob. Planet. Chang. 162 (2018) 148-162 (United States)

    Bąk, Marta; Bąk, Krzysztof; Michalik, Mariola


    The authors regret (Abstract. The causal link between changes in Middle-Late Jurassic radiolarian habitat group abundances, microfacies and water column conditions in the Western Tethys was studied based on the examination of siliceous limestones and cherts from the Tatra Mountains, Central Western Carpathians. Deposition occurred on a morphological high with incised pelagic sedimentation within a tropical zone. High-resolution quantitative analyses of millimetre-thick microlaminae show changes in microfacies constituents that most likely record the fluxes of nutrients and biological activity in superficial waters. Variability of radiolarian assemblages that are classified to represent (i) upwelling and (ii) stratified water taxa suggest successive changes in water conditions that fluctuated between periods of upwelling and periods of formation of a thick, stratified, warm superficial layer above a deep thermocline during middle Bajocian-late Oxfordian time. Such variations would be strongly influenced by ocean-atmosphere global circulation patterns, which are caused by pressure gradients and are the result of Walker circulation along the equatorial part of the Tethys and the Panthalassa Ocean, including the duration of El Niño-like and La Niña-like cycles, which affect sea surface temperature trends on decadal scales. The fluctuations in radiolarian assemblages in the sediments indicate that long-term palaeoceanographic changes occurred on multi-decadal to centennial-scales during the Bajocian, but lengthened in duration to millennial-scale during the Bathonian through the Oxfordian.)

  4. Strong Convergence of a Hybrid Iteration Scheme for Equilibrium Problems, Variational Inequality Problems and Common Fixed Point Problems, of Quasi-ϕ-Asymptotically Nonexpansive Mappings in Banach Spaces

    Directory of Open Access Journals (Sweden)

    Jing Zhao


    Full Text Available We introduce an iterative algorithm for finding a common element of the set of common fixed points of a finite family of closed quasi-ϕ-asymptotically nonexpansive mappings, the set of solutions of an equilibrium problem, and the set of solutions of the variational inequality problem for a γ-inverse strongly monotone mapping in Banach spaces. Then we study the strong convergence of the algorithm. Our results improve and extend the corresponding results announced by many others.

  5. Relative Contributions of Land Use and Climate Change to Water Supply Variations over Yellow River Source Area in Tibetan Plateau during the Past Three Decades. (United States)

    Pan, Tao; Wu, Shaohong; Liu, Yujie


    There is increasing evidence of environmental change impacts on ecosystem processes and services, yet poor understanding of the relative contributions of land use and climate change to ecosystem services variations. Based on detailed meteorological, hydrological records and satellite data over the Yellow River Source Area (YRSA) in Tibetan Plateau from 1980s to 2008, together with a water-yield module of Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and also a Residual Trends (RESTREND) method, we assessed the water supply variations in YRSA during the past three decades and disentangled the relative contributions of land use and climate change. Results show that water supply significantly decreased from 1980 to 2005 and then increased from 2005 to 2008. The quantity slightly decreased from 283.01 mm in 1980 to 276.95 mm in 1995, 270.12 mm in 2000 and 267.97 mm in 2005, and it then rebounded slightly to 275.26 mm in 2008. The water supply variation ranged from 283.01 mm to 267.97 mm. Climate change contributed dominantly to water supply decrease from 1980 to 1995, which accounts for approximately 64% of the decrease. During 1995 to 2000, land use contributed more and about 58% to the water supply decrease as the intense human activities. From 2000 to 2005, climate change became a positive contribution to the water supply as the increased precipitation, but the land use still contributed negatively. From 2005 to 2008, both climate and land use have positive impacts, but land use contributed about 61% to the water supply increase. The implementation of the Three Rivers Source Area Ecological Protection Project has greatly improved the vegetation coverage conditions and the water retention ability during this period. We recommend that the implementation of ecological projects, grazing policies and artificial improvement of degraded grassland would help to conserve the water retention ability and increase water supply.

  6. Carbon and nitrogen elemental and isotopic ratios of filter-feeding bivalves along the French coasts: An assessment of specific, geographic, seasonal and multi-decadal variations. (United States)

    Briant, Nicolas; Savoye, Nicolas; Chouvelon, Tiphaine; David, Valérie; Rodriguez, Samuel; Charlier, Karine; Sonke, Jeroen E; Chiffoleau, Jean François; Brach-Papa, Christophe; Knoery, Joël


    Primary consumers play a key role in coastal ecosystems by transferring organic matter from primary producers to predators. Among them, suspension-feeders, like bivalve molluscs are widely used in trophic web studies. The main goal of this study was to investigate variations of C and N elemental and isotopic ratios in common bivalves (M. edulis, M. galloprovincialis, and C. gigas) at large spatial (i.e. among three coastal regions) and different temporal (i.e. from seasonal to multi-decadal) scales in France, in order to identify potential general or specific patterns and speculate on their drivers. The observed spatial variability was related to the trophic status of the coastal regions (oligotrophic Mediterranean Sea versus meso- to eutrophic English Channel and Atlantic ocean), but not to ecosystem typology (estuaries, versus lagoons versus bays versus littoral systems). Furthermore, it highlighted local specificities in terms of the origin of the POM assimilated by bivalves (e.g., mainly continental POM vs. marine phytoplankton vs. microphytobenthic algae). Likewise, seasonal variability was related both to the reproduction cycle for C/N ratios of Mytilus spp. and to changes in trophic resources for δ 13 C of species located close to river mouth. Multi-decadal evolution exhibited shifts and trends for part of the 30-year series with decreases in δ 13 C and δ 15 N. Specifically, shifts appeared in the early 2000's, likely linking bivalve isotopic ratios to a cascade of processes affected by local drivers. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Morphological variation and habitat modification are strongly correlated for the autogenic ecosystem engineer Spartina anglica (common cordgrass)

    NARCIS (Netherlands)

    van Hulzen, J.B.; Van Soelen, J.; Bouma, T.J.


    We explored to what extent morphological variation and habitat modification are correlated for an autogenic ecosystem engineer, which is an organism that modifies its habitat via its own physical structures. The intertidal salt marsh species Spartina anglica is well known for its capacity to enhance

  8. CpDNA haplotype variation reveals strong human influence on oak stands of the Veluwe forest in the Netherlands

    NARCIS (Netherlands)

    Buiteveld, J.; Koelewijn, H.P.


    We examined chloroplast DNA (cpDNA) variation in 78 oak stands of an important forest complex (the Veluwe) in The Netherlands. Based on historical maps and information oak stands were classified as planted or autochthonous. A genetic study by means of cpDNA haplotype characterisation was carried out

  9. Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions. (United States)

    Brienen, Roel J W; Zuidema, Pieter A; Martínez-Ramos, Miguel


    Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees--those that have not attained the canopy--are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests.

  10. Strong lateral variation of ground temperature revealed by a large network of boreholes in the Slave Geological Province of Canada (United States)

    Gruber, Stephan; Riddick, Julia; Brown, Nick; Karunaratne, Kumari; Kokelj, Steve V.


    The Slave Geological Province is a key region in the Canadian North. Its tundra areas form a large and resource-rich landscape in which comparably few systematic permafrost observations exist. Because the region contains layers of ice-rich till, the ground is susceptible to subsidence during thaw. Consequently, possible impacts of permafrost thawing on infrastructure and the natural environment motivate baseline investigations and simulation studies. In this context, the spatial variation of ground temperatures is relevant: How well can we extrapolate from one or few locations of observation? How well can we describe permafrost characteristics with coarse-grid (e.g., 50 km) models assuming relatively homogenous conditions? In July 2015, an observation network of more than 40 plots was installed to monitor ground thermal regime and to detect surface subsidence. Plots are within few tens of meters to few tens of kilometers from each other and were chosen to represent a distinct combination of surficial geology, vegetation, drainage conditions, and snow accumulation. In each plot (15 m x 15 m), temperatures are recorded in a borehole as well as about 10 cm deep at four locations. Data on surface and subsurface properties has been recorded as well. In September 2016, data was downloaded from the loggers and the conditions of the instruments were described. This contribution presents the first year of temperature data. In the annual averages, it reveals more than 7°C lateral variation between plots as well as within-plot variations of more than 2.5°C. This underscores the need for carefully designing measurement campaigns and methods when aiming to test coarse-scale permafrost simulations, even in gentle topography. The data resulting from this observational network will be made available publicly in the near future.

  11. The Variations and Trends of MODIS C5 & C6 Products’ Errors in the Recent Decade over the Background and Urban Areas of North China

    Directory of Open Access Journals (Sweden)

    Qi Zhang


    Full Text Available With ten-year (2004–2013 ground-based observations of Beijing Forest (BJF and Beijing City (BJC sites in North China, we validated the high-quality MODerate resolution Imaging Spectroradiometer (MODIS Collection 5 (C5 and Collection 6 (C6 Aerosol Optical Depth (AOD products’ precision and discussed the sensors degradation issues. The annual mean AOD and Angstrom exponent (α were 0.20 ± 0.02 and 0.83 ± 0.15 in the background over the past ten years, and they were 0.59 ± 0.07 and 1.13 ± 0.08 in the urban, respectively. Ground-based AOD had both slightly declining trends, with variations of 0.023 and 0.057 over the past decade in the background and urban, respectively. There were large differences among the eight kinds of MODIS AOD products (Terra vs. Aqua, C5 vs. C6, DT (Deep Target vs. DB (Deep Blue, and DTDB in the background and urban areas, but all the products’ monthly errors had larger variations in the spring and summer, and smaller ones in the autumn and winter. In the background, more than 62% of DT matchups for C5 and C6 products were within NASA’s expected error (EE envelope. In the urban, 69%~72% of C6 DB retrievals were falling within EE envelope. The new dataset named C6 DTDB had better performance in the background, whereas it overestimated by 37%~41% in the urban caused by surface reflectivity estimation error. The range of monthly average error varied from −0.21 to 0.28 in the background and from −0.63 to 0.48 in the urban. From the background to the urban areas, the retrieval errors of Terra and Aqua had slightly increased by 0.0023~0.0158 and 0.0011~0.0124 per year, respectively, which implied that the two MODIS instruments had degraded slowly.

  12. Unitary Dynamics of Strongly Interacting Bose Gases with the Time-Dependent Variational Monte Carlo Method in Continuous Space (United States)

    Carleo, Giuseppe; Cevolani, Lorenzo; Sanchez-Palencia, Laurent; Holzmann, Markus


    We introduce the time-dependent variational Monte Carlo method for continuous-space Bose gases. Our approach is based on the systematic expansion of the many-body wave function in terms of multibody correlations and is essentially exact up to adaptive truncation. The method is benchmarked by comparison to an exact Bethe ansatz or existing numerical results for the integrable Lieb-Liniger model. We first show that the many-body wave function achieves high precision for ground-state properties, including energy and first-order as well as second-order correlation functions. Then, we study the out-of-equilibrium, unitary dynamics induced by a quantum quench in the interaction strength. Our time-dependent variational Monte Carlo results are benchmarked by comparison to exact Bethe ansatz results available for a small number of particles, and are also compared to quench action results available for noninteracting initial states. Moreover, our approach allows us to study large particle numbers and general quench protocols, previously inaccessible beyond the mean-field level. Our results suggest that it is possible to find correlated initial states for which the long-term dynamics of local density fluctuations is close to the predictions of a simple Boltzmann ensemble.

  13. Variations of the high-level Balmer line spectrum of the helium-strong star σ Orionis E (United States)

    Smith, M. A.; Bohlender, D. A.


    Using the high-level Balmer lines and continuum, we trace the density structure of two magnetospheric disk segments of the prototypical Bp star σ Orionis E (B2p) as these segments occult portions of the star during the rotational cycle. High-resolution spectra of the Balmer lines ≥H9 and Balmer edge were obtained on seven nights in January-February 2007 at an average sampling of 0.01 cycles. We measured equivalent width variations due to the star occultations by two disk segments 0.4 cycles apart and constructed differential spectra of the migrations of the corresponding absorptions across the Balmer line profiles. We first estimated the rotational and magnetic obliquity angles. We then simulated the observed Balmer jump variation using the model atmosphere codes synspec/circus and evaluated the disk geometry and gas thermodynamics. We find that the two occultations are caused by two disk segments. The first of these transits quickly, indicating that the segment resides in a range of distances, perhaps 2.5-6 R*, from the star. The second consists of a more slowly moving segment situated closer to the surface and causing two semi-resolved absorbing maxima. During its transit this segment brushes across the star's “lower” limb. Judging from the line visibility up to H23-H24 during the occultations, both disk segments have mean densities near 1012 cm-3 and are opaque in the lines and continuum. They have semiheights less than 1/2 R*, and their temperatures are near 10 500 K and 12 000 K, respectively. In all, the disks of Bp stars have a much more complicated geometry than has been anticipated, as evidenced by their (sometimes) non-coplanarity, de-centerness, and from star to star, differences in disk height. Based on observations obtained at the the Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada.

  14. Coral community composition and reef development at the Similan Islands, Andaman Sea, in response to strong environmental variations

    KAUST Repository

    Schmidt, GM


    The Similan Islands, a Thai archipelago in the Andaman Sea located near the shelf break, are subjected to frequent (up to several events per hour) and abrupt changes in physico-chemical conditions, particularly during the dry season (NE monsoon, January through April) and to an intense monsoon season with strong surface wave action (May to October). The exposed west slopes of the islands feature more coral species, but lack a carbonate reef framework. By contrast, the sheltered east sides show a complex reef framework dominated by massive Porites. Our results suggest that the sudden changes in temperature, pH and nutrients (drops of up to 10°C and 0.6 U and increases of up to 9.4 µmol NOx l−1, respectively) due to pulsed upwelling events may rival the importance of surface waves and storms in shaping coral distribution and reef development.

  15. Variation in Genes Related to Cochlear Biology Is Strongly Associated with Adult-Onset Deafness in Border Collies (United States)

    Ruhe, Alison L.; Erdman, Carolyn A.; Robertson, Kathryn R.; Webb, Aubrey A.; Williams, D. Colette; Chang, Melanie L.; Hytönen, Marjo K.; Lohi, Hannes; Hamilton, Steven P.; Neff, Mark W.


    Domestic dogs can suffer from hearing losses that can have profound impacts on working ability and quality of life. We have identified a type of adult-onset hearing loss in Border Collies that appears to have a genetic cause, with an earlier age of onset (3–5 years) than typically expected for aging dogs (8–10 years). Studying this complex trait within pure breeds of dog may greatly increase our ability to identify genomic regions associated with risk of hearing impairment in dogs and in humans. We performed a genome-wide association study (GWAS) to detect loci underlying adult-onset deafness in a sample of 20 affected and 28 control Border Collies. We identified a region on canine chromosome 6 that demonstrates extended support for association surrounding SNP Chr6.25819273 (p-value = 1.09×10−13). To further localize disease-associated variants, targeted next-generation sequencing (NGS) of one affected and two unaffected dogs was performed. Through additional validation based on targeted genotyping of additional cases (n = 23 total) and controls (n = 101 total) and an independent replication cohort of 16 cases and 265 controls, we identified variants in USP31 that were strongly associated with adult-onset deafness in Border Collies, suggesting the involvement of the NF-κB pathway. We found additional support for involvement of RBBP6, which is critical for cochlear development. These findings highlight the utility of GWAS–guided fine-mapping of genetic loci using targeted NGS to study hereditary disorders of the domestic dog that may be analogous to human disorders. PMID:23028339

  16. Variation in genes related to cochlear biology is strongly associated with adult-onset deafness in border collies.

    Directory of Open Access Journals (Sweden)

    Jennifer S Yokoyama


    Full Text Available Domestic dogs can suffer from hearing losses that can have profound impacts on working ability and quality of life. We have identified a type of adult-onset hearing loss in Border Collies that appears to have a genetic cause, with an earlier age of onset (3-5 years than typically expected for aging dogs (8-10 years. Studying this complex trait within pure breeds of dog may greatly increase our ability to identify genomic regions associated with risk of hearing impairment in dogs and in humans. We performed a genome-wide association study (GWAS to detect loci underlying adult-onset deafness in a sample of 20 affected and 28 control Border Collies. We identified a region on canine chromosome 6 that demonstrates extended support for association surrounding SNP Chr6.25819273 (p-value = 1.09 × 10(-13. To further localize disease-associated variants, targeted next-generation sequencing (NGS of one affected and two unaffected dogs was performed. Through additional validation based on targeted genotyping of additional cases (n = 23 total and controls (n = 101 total and an independent replication cohort of 16 cases and 265 controls, we identified variants in USP31 that were strongly associated with adult-onset deafness in Border Collies, suggesting the involvement of the NF-κB pathway. We found additional support for involvement of RBBP6, which is critical for cochlear development. These findings highlight the utility of GWAS-guided fine-mapping of genetic loci using targeted NGS to study hereditary disorders of the domestic dog that may be analogous to human disorders.

  17. Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs

    Directory of Open Access Journals (Sweden)

    Giordano Urbini


    Full Text Available The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because of the strong variations in the BOD5/NO3-N ratios and the unexpected abnormal accumulation of dissolved oxygen during denitrification when the BOD5 load is low. These phenomena cause inhibitory effects and BOD5 deficiency in the denitrification process. The results demonstrate the need for a more complex approach to designing and managing small wastewater treatment plants (WWTPs provided with denitrification than those usually adopted for medium- and large-size plants.

  18. Strong correlation in acene sheets from the active-space variational two-electron reduced density matrix method: effects of symmetry and size. (United States)

    Pelzer, Kenley; Greenman, Loren; Gidofalvi, Gergely; Mazziotti, David A


    Polyaromatic hydrocarbons (PAHs) are a class of organic molecules with importance in several branches of science, including medicine, combustion chemistry, and materials science. The delocalized π-orbital systems in PAHs require highly accurate electronic structure methods to capture strong electron correlation. Treating correlation in PAHs has been challenging because (i) traditional wave function methods for strong correlation have not been applicable since they scale exponentially in the number of strongly correlated orbitals, and (ii) alternative methods such as the density-matrix renormalization group and variational two-electron reduced density matrix (2-RDM) methods have not been applied beyond linear acene chains. In this paper we extend the earlier results from active-space variational 2-RDM theory [Gidofalvi, G.; Mazziotti, D. A. J. Chem. Phys. 2008, 129, 134108] to the more general two-dimensional arrangement of rings--acene sheets--to study the relationship between geometry and electron correlation in PAHs. The acene-sheet calculations, if performed with conventional wave function methods, would require wave function expansions with as many as 1.5 × 10(17) configuration state functions. To measure electron correlation, we employ several RDM-based metrics: (i) natural-orbital occupation numbers, (ii) the 1-RDM von Neumann entropy, (iii) the correlation energy per carbon atom, and (iv) the squared Frobenius norm of the cumulant 2-RDM. The results confirm a trend of increasing polyradical character with increasing molecular size previously observed in linear PAHs and reveal a corresponding trend in two-dimensional (arch-shaped) PAHs. Furthermore, in PAHs of similar size they show significant variations in correlation with geometry. PAHs with the strictly linear geometry (chains) exhibit more electron correlation than PAHs with nonlinear geometries (sheets).

  19. Sediment budget and interannual variations of suspended sediment load in the Rio Cordon (Italy). Three decades of monitoring and investigations (1987-2014). (United States)

    García-Rama, Adriana; Rainato, Riccardo; Mao, Luca; Picco, Lorenzo; Aristide Lenzi, Mario


    This work shows the results of 28 years of measurements carried out in the Rio Cordon catchment, an Alpine watershed where a measuring station continuously recorded water discharge, bedload and suspended sediment transport since 1987. Hourly values of discharge and suspended sediment transport (or 5 min interval during flood events) have been studied throughout the whole study period. Annual and seasonal variations of suspended sediment load during the study period were analyzed along with their contribution to the total sediment yield. Comparing these almost three decades, the highest suspended solid transport occurred in 1994, 2001, 1987, 1998, 2002 and 2009, during which it was 2521.5, 1568.5, 792, 745, 551 and 514.8 t year-1, respectively. Summer and autumn contributions were significant in 1989, 1994, 1996, 1998, 2002, and 2005; on the other hand 2001 was characterized by a snowmelt flood that generated almost all the suspended load. A notable variability of the suspended solid transport can be observed taking in count snowmelt floods. Also 1987, 2001, 2008, 2009 and 2010 are characterized by a very important role of this kind of runoff. Data collected in the Rio Cordon for 28 years show that 75.2% of the total sediment load (10597.8 t of 14088.8 t) was due to suspended sediment transport. In 1994 and 2001, a large portion of the suspended sediment load was mainly supplied during the flood events that occurred in September 1994 and May 2001, which produced 198 and 1017.5 t respectively. Averaging 28 years of data, the mean annual specific sediment yield turns out to be around 102,9 t km-2 year-1. However, this value includes the 1986-1993 period characterized by ordinary flood events during which de mean sediment production was 65.34 t km-2 year-1, the massive sediment yield in 1994 (803.4 t km-2 year-1), the 1995-2000 period (93.2 t km-2 year-1), the 2001 (343.8 km-2 year-1) and the 2002-2014 period(54.5 t km-2 year-1). The highest values correspond to 1994

  20. The variation of dust content with intrinsic galaxy properties: revealing strong dust biases in many commonly-used galaxy property measurements (United States)

    Devour, Brian; Bell, Eric F.


    Dust strongly affects many observations of galaxy properties, and quantifying galaxy dust content and correcting for its effects is a delicate and often uncertain task. In particular, both the impact of dust on commonly-used metrics of galaxy structure and the variation of dust content with intrinsic galaxy properties are poorly quantified. The inclination dependence of dust attenuation is a powerful tool to quantify dust amounts and the effects of dust on galaxy property measurements; this requires the construction of dust and inclination-independent selection techniques to isolate samples of intrinsically similar galaxies for study. To this end we construct dust and inclination-independent measurements of galaxy mass and star formation rate using dust-penetrated infrared datasets, and we develop novel dust and inclination-independent galaxy ‘linear’ size and concentration measurements by collapsing the light distribution in the near-infrared onto the major axis. With these new metrics we select a sample of Milky Way analog galaxies with similar stellar masses, star formation rates, and linear sizes and concentrations. These galaxies - identical save for their orientation - show strong systematic dust and inclination dependence in their Sérsic index, concentration, half-light radius, luminosity, (dust-corrected!) star formation rate and metallicitity, and spectral classification. We use these new metrics to study the variation in relative face-on to edge-on attenuation as a function of intrinsic stellar mass, star formation rate, and linear size and concentration. We find that, if one accounts for geometric and radiative transfer effects, the complex patterns of variation in relative attenuation can be reproduced by simple scaling relation-based dust density models in which dust optical depth is set primarily by gas density and metallicity.

  1. Variations in the geomagnetic and gravitational background associated with two strong earthquakes of the May 2012 sequence in the Po Valley Plain (Italy). (United States)

    Straser, Valentino


    Reawakening of seismic activity in the Emilian Po Valley Plain (Italy) resulted in 2,492 earthquakes over five and a half months: 2,270 with M= 7. The mainshock was recorded during the night of 20 May 2012, at 04:03:52 Italian time (02:03:52 UTC) with epicentre in Finale Emilia, at a depth of 6.3km, by the Italian National Institute of Geophysics and Vulcanology (INGV). A long sequence of telluric shocks occurred in the same seismic district in the areas between the provinces of Modena, Ferrara, Mantua, Reggio Emilia, Bologna and Rovigo. In addition to the general devastation plus damage to civil and industrial buildings and the historical heritage, the earthquakes resulted in a total of 27 victims. Concomitant with the two strongest quakes, recorded on 20 and 29 May 2012, respectively, as in the case of others, variations were noted in the geomagnetic background by the LTPA monitoring station in Rome (Italy). The geomagnetic background variations were associated with the appearance of radio-anomalies in a frequency range from 0.1 to 3.0Hz, as well as gravimetric variations found around 60km from the epicentre. The peak accelerations, detected in correspondence with the strongest shocks on 20 and 29 May 2012, were respectively 0.31g and 0.29g. The appearance of the radio-anomalies coincided, from a temporal point of view, with average gravimetric variations of approximately 30µGal around the epicentre areas, concurrent with the mainshock. In this study, both the appearance of radio-anomalies and the gravitational variations recorded before strong earthquakes were related to the dynamics of the fault and a progressive reduction in granulometry in the core of the fracture, until the point of dislocation was reached. The intense friction in the fault and the damping factors produced before the shock are hypothesized as being proportional to the number of radio-anomalies measured. The radio anomaly is an unknown radio emission that has no characteristics (duration

  2. Determining the contributions of urbanisation and climate change to NPP variations over the last decade in the Yangtze River Delta, China. (United States)

    Wu, Shaohua; Zhou, Shenglu; Chen, Dongxiang; Wei, Zongqiang; Dai, Liang; Li, Xingong


    Terrestrial net primary production (NPP) is an important measure of global change, and identifying the relative contributions of urbanisation and climate change to NPP is important for understanding the impact of human and natural influences on terrestrial systems and the carbon cycle. The objective of this study was to reveal how urbanisation and climate drive changes in NPP. Satellite-based estimates of NPP collected over a 12-year period (1999-2010) were analysed to identify NPP variations in the Yangtze River Delta. Temporal and spatial analysis methods were used to identify the relationships among NPP, nighttime light urbanisation index values, and climatic factors from pixel to regional scales. The NPP of the entire Yangtze River Delta decreased slightly at a rate of -0.5 g C m(-2)a(-1) from 1999 to 2010, but this change was not significant. However, in the urban region, NPP decreased significantly (pclimate change to NPP variation. The results revealed that the urbanisation factor is the main driving force for NPP change in high-speed urbanisation areas, and the factor accounted for 47% of the variations. However, in the forest and farm regions, the NPP variation was mainly controlled by climate change and residual factors. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Analysis of Historical and CMIP5 Projections of Multi-decadal Climatic Variation and Implications for Ecosystem Management on the Colorado Plateau (United States)

    Baker, B.; Wang, S. S.; Smith, K.


    Increasing pressures on ecosystems of the Colorado Plateau, in particular changes in land use and anthropogenically forced changes in climate, are moving these systems toward "thresholds" that may not be re-traversed once crossed. Recent studies have shown that changes in winter temperature and hydrological fluxes in the western United States are outside the range of natural variability. These observations suggest that the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) are acting synergistically with underlying climatic trends associated with increased greenhouse gas forcings. Of particular importance for the Colorado Plateau (CP), future warming may alter the position and strength of the North American Monsoon (NAM), which is responsible for a sharp summertime moisture gradient across the region. Natural resource managers are faced with unprecedented challenges if these trends continue. The goal of the project was to describe historical and future projected inter-annual and multi-decadal variability of precipitation in the northern limits of the NAM region, analyze future projected changes on the hydrological regime, and discuss implications for management of these semi-arid ecosystems. Daily climate records were analyzed to quantify the current and historical spatio-temporal pattern of precipitation across the CP using results from ten CMIP5 climate models that best reproduce climate metrics of PDO and ENSO across the study area. Results suggest that a focus on the variability and pattern change in extreme climate anomalies, is vital to inform the management of natural resources. Specifically, inter- and intra-annual variability, seasonality of temperature and precipitation, as well as interactions between multi-decadal cycles trends driven by large-scale climate dynamics, need to be considered. Policies that guide management actions into the future should be based on strategies that cover a wide range of plausible climatic conditions.

  4. Using a semi-distributed physically-based hydrological model to explain diurnal to decadal scale ice velocity variations on Franz Josef Glacier (Ka Roimata o Hine Hukatere), New Zealand (United States)

    Willis, I. C.; Anderson, B. M.; Banwell, A. F.; Goodsell, B.; Owens, I. F.; Mackintosh, A. N.; Lawson, W.


    Franz Josef Glacier provides a rare opportunity to observe the dynamics of a fast-flowing, maritime glacier that differs significantly from many 'typical' alpine glaciers. In particular, Franz Josef Glacier tongue has limited ranges in both diurnal and seasonal temperature, significant volumes of melt and rainwater present year-round, and has been through a recent advance/retreat cycle. Previous studies indicate these factors have a significant influence on surface motion. This paper presents surface velocity measurements made over a ten year period between 2000 and 2010 at a variety of resolutions, notably hourly, daily, weekly, monthly, and yearly. A distributed degree-day based mass balance model is used to calculate spatial and temporal variations in snow / ice melt and rainfall across the glacier each day of the decade and these are used as input to a semi-distributed physically based model representing the englacial / subglacial drainage system. Key outputs are spatial and temporal variations in subglacial water pressure and discharge. Because the glacier is relatively thin and steep, subglacial conduits operate at atmospheric pressure over most of the glacier's length for most of the time. High pressure events are confined to specific places, generally at times of high melt or rain inputs. Daily to monthly ice velocity variations can be linked to corresponding fluctuations in subglacial water pressures. Year-to-year velocity variations are linked more to variations in glacier geometry and advance/retreat cycles. Short- to medium-term ice velocity variations reflect rapid changes in basal motion, whereas longer-term variations reflect changes in ice deformation and longitudinal stress gradients.

  5. Annual variation in δ13C values of maize and wheat: Effect on estimates of decadal scale soil carbon turnover

    DEFF Research Database (Denmark)

    Christensen, Bent Tolstrup; Olesen, Jørgen E; Hansen, Elly Møller


    On sites where C4-plants have replaced C3-plants, changes in soil δ13C allow the turnover of C3- and C4-derived C to be separated. Studies of decadal scale turnover of soil C following conversion to C4-plants generally lack δ13C values for previous C4-residue inputs and assume that estimates of C4......-derived soil C to be based on a fixed δ13C value. Further assumptions are that changes in the initial (time-zero) soil δ13C values are insignificant following conversion to C4-plants. We tested these assumptions by measuring: 1) the δ13C of annual samples of silage maize biomass (C4-plant) and winter...... to centuries, the subtle but consistent changes in plant and soil δ13C need to be accounted for. The variability in δ13C in wheat grains suggest that the use of any fixed δ13C value for C3-residues in estimates of C turnover in soils on which C4-plants have been replaced by C3-plants can be associated...

  6. Population genomic analysis suggests strong influence of river network on spatial distribution of genetic variation in invasive saltcedar across the southwestern United States (United States)

    Lee, Soo-Rang; Jo, Yeong-Seok; Park, Chan-Ho; Friedman, Jonathan M.; Olson, Matthew S.


    Understanding the complex influences of landscape and anthropogenic elements that shape the population genetic structure of invasive species provides insight into patterns of colonization and spread. The application of landscape genomics techniques to these questions may offer detailed, previously undocumented insights into factors influencing species invasions. We investigated the spatial pattern of genetic variation and the influences of landscape factors on population similarity in an invasive riparian shrub, saltcedar (Tamarix L.) by analysing 1,997 genomewide SNP markers for 259 individuals from 25 populations collected throughout the southwestern United States. Our results revealed a broad-scale spatial genetic differentiation of saltcedar populations between the Colorado and Rio Grande river basins and identified potential barriers to population similarity along both river systems. River pathways most strongly contributed to population similarity. In contrast, low temperature and dams likely served as barriers to population similarity. We hypothesize that large-scale geographic patterns in genetic diversity resulted from a combination of early introductions from distinct populations, the subsequent influence of natural selection, dispersal barriers and founder effects during range expansion.

  7. HIV prevalence is strongly associated with geographical variations in male circumcision and foreskin cutting in Papua New Guinea: an ecological study. (United States)

    MacLaren, David J; McBride, W John H; Kelly, Gerard C; Muller, Reinhold; Tommbe, Rachael; Kaldor, John M; Vallely, Andrew J


    To examine the correlation between HIV prevalence and male circumcision and other foreskin cutting practices across the four regions of Papua New Guinea (PNG). An ecological substudy using unique data from an interdisciplinary research programme to evaluate the acceptability, sociocultural context and public health impact of male circumcision for HIV prevention in PNG. Published data describing (a) self-reported circumcision status by region from the 'Acceptability and Feasibility of Male Circumcision for HIV prevention in PNG' study and (b) HIV prevalence by region from PNG National Department of Health were used to correlate male circumcision and other foreskin cutting practices and HIV prevalence. Maps were constructed to visually represent variations across the four regions of PNG. Regions of PNG with the highest HIV prevalence had the lowest prevalence of male circumcision and other forms of foreskin cutting and vice versa. Male circumcision and dorsal longitudinal cuts were strongly associated with HIV prevalence and able to explain 99% of the observed geographical variability in HIV prevalence in PNG (pPNG appears to be closely correlated with the regional distribution of male circumcision and dorsal longitudinal foreskin cuts. Further research is warranted to investigate causality of this correlation as well as the potential of dorsal longitudinal cuts to confer protection against HIV acquisition in heterosexual men. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  8. Recent Decadal Variations of El Nino Predictability (United States)

    Wang, Guomin; Hendon, Harry; Zhao, Mei


    Predictive skill for El Niño in the equatorial eastern Pacific across a range of forecast models declined in the early 21st century relative to what was achieved in the late 20th century. This decline coincided with a reduction of El Niño variability in the eastern Pacific and a shift in Pacific climate to an enhanced east-west surface temperature gradient and stronger trade winds in the central Pacific, which has previously been associated with the recent hiatus in global surface warming. It is an outstanding question as to whether this shift in climate at the end of the 20th century acted to weaken El Niño variability, hence predictability, or whether El Niño variability weakened by chance thus reducing predictability but in so doing resulted in the shift in climate. Using seasonal forecast sensitivity experiments with the Australian Bureau of Meteorology coupled model POAMA2.4, the shift to intensified east-west surface temperature gradient and stronger central Pacific trade winds is shown to weaken the ocean-atmosphere feedback that amplify eastern Pacific El Niño, thus resulting in weaker variability that is less predictable. This weakened coupling helps explain the fitful behaviour and challenges for forecasting the non-developing El Niño in early 2014. In contrast, the Pacific mean state appears to have swung to a more favourable condition for promoting El Nino toward the end of 2014, thus supporting stronger development of El Nino in 2015.

  9. Tides and Decadal Variability (United States)

    Ray, Richard D.


    This paper reviews the mechanisms by which oceanic tides and decadal variability in the oceans are connected. We distinguish between variability caused by tides and variability observed in the tides themselves. Both effects have been detected at some level. The most obvious connection with decadal timescales is through the 18.6-year precession of the moon's orbit plane. This precession gives rise to a small tide of the same period and to 18.6-year modulations in the phase and amplitudes of short-period tides. The 18.6-year "node tide" is very small, no more than 2 cm anywhere, and in sea level data it is dominated by the ocean's natural Variability. Some authors have naively attributed climate variations with periods near 19 years directly to the node tide, but the amplitude of the tide is too small for this mechanism to be operative. The more likely explanation (Loder and Garrett, JGR, 83, 1967-70, 1978) is that the 18.6-y modulations in short-period tides, especially h e principal tide M2, cause variations in ocean mixing, which is then observed in temperature and other climatic indicators. Tidally forced variability has also been proposed by some authors, either in response to occasional (and highly predictable) tidal extremes or as a nonlinear low-frequency oscillation caused by interactions between short-period tides. The former mechanism can produce only short-duration events hardly more significant than normal tidal ranges, but the latter mechanism can in principle induce low-frequency oscillations. The most recent proposal of this type is by Keeling and Whorf, who highlight the 1800-year spectral peak discovered by Bond et al. (1997). But the proposal appears contrived and should be considered, in the words of Munk et al. (2002), "as the most likely among unlikely candidates."

  10. Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)


    Massimo Raboni; Vincenzo Torretta; Giordano Urbini


    The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because ...

  11. A multivariate analysis of variation in genome size and endoreduplication in angiosperms reveals strong phylogenetic signal and association with phenotypic traits. (United States)

    Bainard, Jillian D; Bainard, Luke D; Henry, Thomas A; Fazekas, Aron J; Newmaster, Steven G


    Genome size (C-value) and endopolyploidy (endoreduplication index, EI) are known to correlate with various morphological and ecological traits, in addition to phylogenetic placement. A phylogenetically controlled multivariate analysis was used to explore the relationships between DNA content and phenotype in angiosperms. Seeds from 41 angiosperm species (17 families) were grown in a common glasshouse experiment. Genome size (2C-value and 1Cx-value) and EI (in four tissues: leaf, stem, root, petal) were determined using flow cytometry. The phylogenetic signal was calculated for each measure of DNA content, and phylogenetic canonical correlation analysis (PCCA) explored how the variation in genome size and EI was correlated with 18 morphological and ecological traits. Phylogenetic signal (λ) was strongest for EI in all tissues, and λ was stronger for the 2C-value than the 1Cx-value. PCCA revealed that EI was correlated with pollen length, stem height, seed mass, dispersal mechanism, arbuscular mycorrhizal association, life history and flowering time, and EI and genome size were both correlated with stem height and life history. PCCA provided an effective way to explore multiple factors of DNA content variation and phenotypic traits in a phylogenetic context. Traits that were correlated significantly with DNA content were linked to plant competitive ability. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  12. Unitary Dynamics of Strongly Interacting Bose Gases with the Time-Dependent Variational Monte Carlo Method in Continuous Space

    Directory of Open Access Journals (Sweden)

    Giuseppe Carleo


    Full Text Available We introduce the time-dependent variational Monte Carlo method for continuous-space Bose gases. Our approach is based on the systematic expansion of the many-body wave function in terms of multibody correlations and is essentially exact up to adaptive truncation. The method is benchmarked by comparison to an exact Bethe ansatz or existing numerical results for the integrable Lieb-Liniger model. We first show that the many-body wave function achieves high precision for ground-state properties, including energy and first-order as well as second-order correlation functions. Then, we study the out-of-equilibrium, unitary dynamics induced by a quantum quench in the interaction strength. Our time-dependent variational Monte Carlo results are benchmarked by comparison to exact Bethe ansatz results available for a small number of particles, and are also compared to quench action results available for noninteracting initial states. Moreover, our approach allows us to study large particle numbers and general quench protocols, previously inaccessible beyond the mean-field level. Our results suggest that it is possible to find correlated initial states for which the long-term dynamics of local density fluctuations is close to the predictions of a simple Boltzmann ensemble.

  13. Strong genetic structure revealed by multilocus patterns of variation in Giardia duodenalis isolates of patients from Galicia (NW-Iberian Peninsula). (United States)

    Gabín-García, Luis B; Bartolomé, Carolina; Abal-Fabeiro, José L; Méndez, Santiago; Llovo, José; Maside, Xulio


    We report a survey of genetic variation at three coding loci in Giardia duodenalis of assemblages A and B obtained from stool samples of patients from Santiago de Compostela (Galicia, NW-Iberian Peninsula). The mean pooled synonymous diversity for assemblage A was nearly five times lower than for assemblage B (0.77%±0.30% and 4.14%±1.65%, respectively). Synonymous variation in both assemblages was in mutation-drift equilibrium and an excess of low-frequency nonsynonymous variants suggested the action of purifying selection at the three loci. Differences between isolates contributed to 40% and 60% of total genetic variance in assemblages A and B, respectively, which revealed a significant genetic structure. These results, together with the lack of evidence for recombination, support that (i) Giardia assemblages A and B are in demographic equilibrium and behave as two genetically isolated populations, (ii) infections are initiated by a reduced number of individuals, which may be genetically diverse and even belong to different assemblages, and (iii) parasites reproduce clonally within the host. However, the observation of invariant loci in some isolates means that mechanisms for the homogenization of the genetic content of the two diploid nuclei in each individual must exist. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A De Novo Genome Sequence Assembly of the Arabidopsis thaliana Accession Niederzenz-1 Displays Presence/Absence Variation and Strong Synteny.

    Directory of Open Access Journals (Sweden)

    Boas Pucker

    Full Text Available Arabidopsis thaliana is the most important model organism for fundamental plant biology. The genome diversity of different accessions of this species has been intensively studied, for example in the 1001 genome project which led to the identification of many small nucleotide polymorphisms (SNPs and small insertions and deletions (InDels. In addition, presence/absence variation (PAV, copy number variation (CNV and mobile genetic elements contribute to genomic differences between A. thaliana accessions. To address larger genome rearrangements between the A. thaliana reference accession Columbia-0 (Col-0 and another accession of about average distance to Col-0, we created a de novo next generation sequencing (NGS-based assembly from the accession Niederzenz-1 (Nd-1. The result was evaluated with respect to assembly strategy and synteny to Col-0. We provide a high quality genome sequence of the A. thaliana accession (Nd-1, LXSY01000000. The assembly displays an N50 of 0.590 Mbp and covers 99% of the Col-0 reference sequence. Scaffolds from the de novo assembly were positioned on the basis of sequence similarity to the reference. Errors in this automatic scaffold anchoring were manually corrected based on analyzing reciprocal best BLAST hits (RBHs of genes. Comparison of the final Nd-1 assembly to the reference revealed duplications and deletions (PAV. We identified 826 insertions and 746 deletions in Nd-1. Randomly selected candidates of PAV were experimentally validated. Our Nd-1 de novo assembly allowed reliable identification of larger genic and intergenic variants, which was difficult or error-prone by short read mapping approaches alone. While overall sequence similarity as well as synteny is very high, we detected short and larger (affecting more than 100 bp differences between Col-0 and Nd-1 based on bi-directional comparisons. The de novo assembly provided here and additional assemblies that will certainly be published in the future will

  15. PRS projections for DECADE (United States)

    Whitney, K. G.; Thornhill, J. W.; Giuliani, J. L., Jr.; Davis, J.


    Two approaches are described for predicting and evaluating the potential range of PRS performance on DECADE. On the one hand, the DECADE generator is represented as a lumped electrical circuit coupled to an inductive PRS load using slug model dynamics for the load. The nonlinearly coupled circuit equations determine the energy transfer from the Marx bank to the load as a function of the circuit parameters, enabling one to predict the efficiency for converting Marx bank energy into load kinetic energy. Newly experimentally confirmed scaling relations then allow one to predict the conversion fraction of this kinetic energy into K-shell x rays. Both aluminum and titanium should be able to generate in excess of 100 kJ/cm of K-shell radiation based on the DECADE circuit model used in this report. On the other hand, power flow from the Marx generator to the load is taken as a given, and a number of specific issues related to PRS load dynamics are calculated using detailed (non-slug) models of the load MHD dynamics. A number of such issues are discussed. They need to be addressed because of their potential to either degrade or enhance the load yield performance predicted on the basis of kinetic energy and x ray scaling laws alone. These issues also deal with matters of x ray simulation fidelity that will be an important part of DECADE's function. It is argued that the capability to carry out aluminum radiative collapse experiments on DECADE is significantly greater than on existing simulators, and that these experiments may offer a range of opportunity for improving simulation fidelity beyond that offered by kinetic energy scaling alone. This represents a compelling reason for giving DECADE a PRS capability.

  16. A Decade of Suspicion

    DEFF Research Database (Denmark)

    Rytter, Mikkel; Pedersen, Marianne Holm


    In 2011, al-Qaeda leader, Osama Bin Laden, was killed in Pakistan and the US president, Barack Obama, concluded a decade of global ‘war against terror’. In light of this, it seems only sensible to explore what implications the post-9/11 international developments have had on a local basis...

  17. International Lunar Decade Status (United States)

    Beldavs, VZ; Crisafulli, J.; Dunlop, D.; Foing, B.


    The International Lunar Decade is a global decadal event designed to provide a framework for strategically directed international cooperation for permanent return to the Moon. To be launched July 20, 2019, the 50th anniversary of the giant leap for mankind marked by Neil Armstrong's first step on the Moon, the ILD launch will include events around the world to celebrate space exploration, science, and the expansion of humanity into the Solar System. The ILD framework links lunar exploration and space sciences with the development of enabling technologies, infrastructure, means of financing, laws and policies aimed at lowering the costs and risks of venturing into space. Dramatically reduced costs will broaden the range of opportunities available in space and widen access to space for more states, companies and people worldwide. The ILD is intended to bring about the efflorescence of commercial business based on space resources from the Moon, asteroids, comets and other bodies in the Solar System.

  18. The IGISOL technique : three decades of developments

    NARCIS (Netherlands)

    Moore, I.D.; Dendooven, Peter; Ärje, J.

    The Ion Guide Isotope SeparatorOn-Line (IGISOL) technique, conceived in the early 1980s as a novel variation to the helium-jet method, has been used to provide radioactive ion beams of short-lived exotic nuclei for fundamental nuclear structure research and applications for three decades. This

  19. North-South precipitation patterns in western North America on interannual-to-decadal timescales (United States)

    Dettinger, M.D.; Cayan, D.R.; Diaz, Henry F.; Meko, D.M.


    The overall amount of precipitation deposited along the West Coast and western cordillera of North America from 25??to 55??N varies from year to year, and superimposed on this domain-average variability are varying north-south contrasts on timescales from at least interannual to interdecadal. In order to better understand the north-south precipitation contrasts, their interannual and decadal variations are studied in terms of how much they affect overall precipitation amounts and how they are related to large-scale climatic patterns. Spatial empirical orthogonal functions (EOFs) and spatial moments (domain average, central latitude, and latitudinal spread) of zonally averaged precipitation anomalies along the westernmost parts of North America are analyzed, and each is correlated with global sea level pressure (SLP) and sea surface temperature series, on interannual (defined here as 3-7 yr) and decadal (>7 yr) timescales. The interannual band considered here corresponds to timescales that are particularly strong in tropical climate variations and thus is expected to contain much precipitation variability that is related to El Nino-Southern Oscillation; the decadal scale is defined so as to capture the whole range of long-term climatic variations affecting western North America. Zonal EOFs of the interannual and decadal filtered versions of the zonal-precipitation series are remarkably similar. At both timescales, two leading EOFs describe 1) a north-south seesaw of precipitation pivoting near 40??N and 2) variations in precipitation near 40??N, respectively. The amount of overall precipitation variability is only about 10% of the mean and is largely determined by precipitation variations around 40??-45??N and most consistently influenced by nearby circulation patterns; in this sense, domain-average precipitation is closely related to the second EOF. The central latitude and latitudinal spread of precipitation distributions are strongly influenced by precipitation

  20. Seasonal and decadal information towards climate services: EUPORIAS (United States)

    Buontempo, Carlo; Hewitt, Chris


    Societies have always faced challenges and opportunities arising from variations in climate, and have often flourished or collapsed depending on their ability to adapt to such changes. Recent advances in our understanding and ability to forecast climate variability and climate change have meant that skilful predictions are beginning to be routinely made on seasonal to decadal (s2d) timescales. Such forecasts have the potential to be of great value to a wide range of decision-making, where outcomes are strongly influenced by variations in the climate. The European Commission have recently commissioned a major four year long project (EUPORIAS) to develop prototype end-to-end climate impact prediction services operating on a seasonal to decadal timescale, and assess their value in informing decision-making. EUPORIAS commenced on 1 November 2012, coordinated by the UK Met Office leading a consortium of 24 organisations representing world-class European climate research and climate service centres, expertise in impacts assessments and seasonal predictions, two United Nations agencies, specialists in new media, and commercial companies in climate-vulnerable sectors such as energy, water and tourism. The paper describes the setup of the project, its main outcome and some of the very preliminary results.

  1. Decadal-Interdecadal SST Variability and Regional Climate Teleconnections (United States)

    Lau, William K. M.; Weng, H.; Einaudi, Franco (Technical Monitor)


    Dominant modes of decadal and interdecadal SST variability and their impacts on summertime rainfall variability over East Asia and the North America are studied. Two dominant modes of interdecadal SST variability, one associated with El Nino-like warming in the global oceans and one with an east-west seesaw variation in the equatorial Pacific have been identified. The first mode is associated in part with a long-term warming trend in the topical oceans and cooling over the northern Pacific. The second mode suggests an westward shift and strengthening of the Walker circulation from 1960s to the 1980s. Over East Asian, the first SST mode is correlated with reduced rainfall in northern China and excessive rainfall in central China. This SST mode is also associated with the tendency for increased rainfall over the midwest region, and reduced rainfall over the east Coast of the US. The results suggest a teleconnection pattern which links the occurrences of drought and floods over the Asian monsoon and the US summertime time climate. This teleconnection is likely to be associated with decadal variability of the East Asian jetstream, which are affected by strong land surface heating over the Siberian region, as well as El Nino-like SST forcings. The occurrences of major droughts and floods in the East Asian and US continent in recent decades are discussed in light of the above teleconnection patterns.

  2. Mechanisms underlying recent decadal changes in subpolar North Atlantic Ocean heat content (United States)

    Piecuch, Christopher G.; Ponte, Rui M.; Little, Christopher M.; Buckley, Martha W.; Fukumori, Ichiro


    The subpolar North Atlantic (SPNA) is subject to strong decadal variability, with implications for surface climate and its predictability. In 2004-2005, SPNA decadal upper ocean and sea-surface temperature trends reversed from warming during 1994-2004 to cooling over 2005-2015. This recent decadal trend reversal in SPNA ocean heat content (OHC) is studied using a physically consistent, observationally constrained global ocean state estimate covering 1992-2015. The estimate's physical consistency facilitates quantitative causal attribution of ocean variations. Closed heat budget diagnostics reveal that the SPNA OHC trend reversal is the result of heat advection by midlatitude ocean circulation. Kinematic decompositions reveal that changes in the deep and intermediate vertical overturning circulation cannot account for the trend reversal, but rather ocean heat transports by horizontal gyre circulations render the primary contributions. The shift in horizontal gyre advection reflects anomalous circulation acting on the mean temperature gradients. Maximum covariance analysis (MCA) reveals strong covariation between the anomalous horizontal gyre circulation and variations in the local wind stress curl, suggestive of a Sverdrup response. Results have implications for decadal predictability.

  3. An empirical model of decadal ENSO variability

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, S. [University of Wisconsin-Milwaukee, Department of Mathematical Sciences, Atmospheric Sciences Group, P. O. Box 413, Milwaukee, WI (United States)


    This paper assesses potential predictability of decadal variations in the El Nino/Southern Oscillation (ENSO) characteristics by constructing and performing simulations using an empirical nonlinear stochastic model of an ENSO index. The model employs decomposition of global sea-surface temperature (SST) anomalies into the modes that maximize the ratio of interdecadal-to-subdecadal SST variance to define low-frequency predictors called the canonical variates (CVs). When the whole available SST time series is so processed, the leading canonical variate (CV-1) is found to be well correlated with the area-averaged SST time series which exhibits a non-uniform warming trend, while the next two (CV-2 and CV-3) describe secular variability arguably associated with a combination of Atlantic Multidecadal Oscillation (AMO) and Pacific Decadal Oscillation (PDO) signals. The corresponding ENSO model that uses either all three (CVs 1-3) or only AMO/PDO-related (CVs 2 and 3) predictors captures well the observed autocorrelation function, probability density function, seasonal dependence of ENSO, and, most importantly, the observed interdecadal modulation of ENSO variance. The latter modulation, and its dependence on CVs, is shown to be inconsistent with the null hypothesis of random decadal ENSO variations simulated by multivariate linear inverse models. Cross-validated hindcasts of ENSO variance suggest a potential useful skill at decadal lead times. These findings thus argue that decadal modulations of ENSO variability may be predictable subject to our ability to forecast AMO/PDO-type climate modes; the latter forecasts may need to be based on simulations of dynamical models, rather than on a purely statistical scheme as in the present paper. (orig.)

  4. The second decade

    Directory of Open Access Journals (Sweden)

    M. Amini


    Full Text Available   It is ten years since the Iranian Journal of Physics Research has been in publication. For the Occasion of the 10th anniversary of its publication, we have planned several changes and modifications. These includes increasing the annual issues to four and omission of Introduction of Previously-Published Papers in International Journals section. In this article some statistical information of the published articles is given together with the index of the journals referees. As we enter the second decade of our publication, we face several questions. In this article we share these questions with our readers in the hope of finding the best possible solutions, so that we would be able to publish a better journal in future.

  5. Inter-decade variations of the climate in Central Europe: Influence of the Atlantic Ocean and effects on the daily weather. Final report; Interdekadenschwankungen des Klimas in Mitteleuropa: Einfluss des atlantischen Ozeans und Auswirkungen im taeglichen Wetter. Endbericht

    Energy Technology Data Exchange (ETDEWEB)



    The project had four important scientific aims: 1. The excecution and evaluation of simulations with the ECHAM model for the analysis of the model reaction on changed oceanic water surface temperatures (SST). 2. The production of a hierarchy of simplified models for the statistical evaluation and dynamic interpretation of model and observation data. 3. The analysis of the decade variability of synoptic disturbances (`weather`) from the hemispheric geopotential and ground pressure data of the German Weather Service (DWD). 4. The analysis of the long-term variability of synoptic disturbances and the averaged variables form daily radio-sonde ascents. (orig./KW) [Deutsch] Das Projekt hatte vier wesentliche wissenschaftliche Ziele: 1. die Durchfuehrung und Auswertung von Simulationen mit dem ECHAM Modell zur Analyse der Modellreaktion auf geaenderte ozeanische Wasseroberflaechentemperaturen (SST). 2. Die Erstellung einer Hierarchie von vereinfachten Modellen zur statischen Auswertung und dynamischen Interpretation von Modell- und Beobachtungsdaten. 3. Die Analyse der dekadischen Variabilitaet synoptischer Stoerungen (`Wetter`) anhand der hemisphaerischen Geopotential- und Bodendruckdaten des Deutschen Wetterdienstes (DWD). 4.Die Analyse der langfristigen Variabilitaet synoptischer Stoerungen und der gemittelten Variablen anhand von taeglichen Radiosondenaufstiegen. (orig./KW)

  6. Prospects for decadal climate prediction


    Keenlyside, Noel; Ba, Jin


    During the last decade, global surface temperatures did not increase as rapidly as in the preceding decades. Although relatively small compared to the observed centennial scale global warming, it has renewed interest in understanding and even predicting climate on time scales of decades, and sparked a community initiative on near‐term prediction that will feature in the fifth intergovernmental panel on climate change assessment report. Decadal prediction, however, is in its infancy, with only...

  7. Development and evaluation of a high-resolution reanalysis of the East Australian Current region using the Regional Ocean Modelling System (ROMS 3.4) and Incremental Strong-Constraint 4-Dimensional Variational (IS4D-Var) data assimilation (United States)

    Kerry, Colette; Powell, Brian; Roughan, Moninya; Oke, Peter


    As with other Western Boundary Currents globally, the East Australian Current (EAC) is highly variable making it a challenge to model and predict. For the EAC region, we combine a high-resolution state-of-the-art numerical ocean model with a variety of traditional and newly available observations using an advanced variational data assimilation scheme. The numerical model is configured using the Regional Ocean Modelling System (ROMS 3.4) and takes boundary forcing from the BlueLink ReANalysis (BRAN3). For the data assimilation, we use an Incremental Strong-Constraint 4-Dimensional Variational (IS4D-Var) scheme, which uses the model dynamics to perturb the initial conditions, atmospheric forcing, and boundary conditions, such that the modelled ocean state better fits and is in balance with the observations. This paper describes the data assimilative model configuration that achieves a significant reduction of the difference between the modelled solution and the observations to give a dynamically consistent "best estimate" of the ocean state over a 2-year period. The reanalysis is shown to represent both assimilated and non-assimilated observations well. It achieves mean spatially averaged root mean squared (rms) residuals with the observations of 7.6 cm for sea surface height (SSH) and 0.4 °C for sea surface temperature (SST) over the assimilation period. The time-mean rms residual for subsurface temperature measured by Argo floats is a maximum of 0.9 °C between water depths of 100 and 300 m and smaller throughout the rest of the water column. Velocities at several offshore and continental shelf moorings are well represented in the reanalysis with complex correlations between 0.8 and 1 for all observations in the upper 500 m. Surface radial velocities from a high-frequency radar array are assimilated and the reanalysis provides surface velocity estimates with complex correlations with observed velocities of 0.8-1 across the radar footprint. A comparison with

  8. Variations in long term wind speed during different decades in ...

    Indian Academy of Sciences (India)

    A study has been carried out by comparing the extreme wind speeds estimated based on. NCEP/NCAR reanalysis data for 100 years return period using Fischer Tippet-1 (commonly known as Gumbel) and Weibull distributions for three locations (off Goa, Visakhapatnam and Machili- patnam) in the north Indian Ocean.

  9. Decadal Variations in NDVI and Food Production in India (United States)

    National Aeronautics and Space Administration — In this study we use long-term satellite, climate, and crop observations to document the spatial distribution of the recent stagnation in food grain production...

  10. Variations in long term wind speed during different decades in ...

    Indian Academy of Sciences (India)

    A study has been carried out by comparing the extreme wind speeds estimated based on NCEP/NCAR reanalysis data for 100 years return period using Fischer Tippet-1 (commonly known as Gumbel)and Weibull distributions for three locations (off Goa,Visakhapatnam and Machilipatnam)in the north Indian Ocean.

  11. Decadal period external magnetic field variations determined via eigenanalysis

    DEFF Research Database (Denmark)

    Shore, R. M.; Whaler, K. A.; Macmillan, S.


    to a full solar cycle. Our analysis focuses on geomagnetically quiet days and middle to low latitudes. We use the climatological eigenanalysis technique called empirical orthogonal functions (EOFs), which allows us to identify discrete spatiotemporal patterns with no a priori specification of their geometry...

  12. Decadal variation of ocean heat content and tropical cyclone activity ...

    Indian Academy of Sciences (India)

    The role of UOHC in enhancing convection and providing heat supply for more number of low ..... It is also remarkable that the anomaly of SST changed sign around 1988 and steadily increased thereafter. The trend line of SST anomaly shows significant increasing trend. (99.9%), whereas the TC frequency is of decreas-.

  13. Spatial and decadal variations in satellite-based terrestrial ...

    Indian Academy of Sciences (India)

    Zhaolu Zhang


    Dec 2, 2017 ... transferring by air motion. Regional climate change has produced substan- tial effects on terrestrial ET and surface drought by altering environmental controlling factors. How- ever, there are different controlling factors for ET in different climate zones (Wang and Dickinson. 2012). In high-latitude ecosystems ...

  14. Books average previous decade of economic misery. (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios


    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  15. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.


    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  16. Building strong brands – does it matter?


    Aure, Kristin Gaaseide; Nervik, Kristine Dybvik


    Brand equity has proven, through several decades of research, to be a primary source of competitive advantage and future earnings (Yoo & Donthu, 2001). Building strong brands has therefore become a priority for many organizations, with the presumption that building strong brands yields these advantages (Yasin et al., 2007). A quantitative survey was conducted at Sunnmøre in Norway in order to answer the two developed research questions. - Does the brand equity dimensions; brand...

  17. Changes in the in-phase relationship between the Indian and subsequent Australian summer monsoons during the past five decades

    Directory of Open Access Journals (Sweden)

    J.-Y. Yu


    Full Text Available This study examines the decadal changes in the in-phase relationship between Indian summer monsoon and the subsequent Australian summer monsoon using observational data from 1950–2005. The in-phase relationship is the tendency for a strong Indian summer monsoon to be followed by a strong Australian summer monsoon and vice versa. It is found that the in-phase relationship was weak during the late 1950s and early 1960s, strengthened to a maximum in the early 1970s just before the 1976/77 Pacific climate shift, then declined until the late 1990s. Pacific SST anomalies are noticed to have strong persistence from boreal to austral summer, providing the memory to connect the Indian and subsequent Australian summer monsoon. The simultaneous correlation between the Pacific SST anomalies and the Indian summer monsoon is always strong. It is the weakening and strengthening of the simultaneous correlation between the Australian summer monsoon and the Pacific SST anomalies that contributes to the decadal variations of the in-phase monsoon relation. This study suggests that the interaction between the Australian monsoon and the Pacific Ocean is crucial to tropical climate variability and has experienced significant changes over the past five decades.

  18. DECADE design and testing status

    International Nuclear Information System (INIS)

    Sincerny, P.; Childers, K.; Goyer, J.; Kortbawi, D.; Roth, I.; Stallings, C.; Dempsey, J.; Schlitt, L.


    DECADE is a very high power generator that will be built at Arnold Engineering Development Center in Tullahoma, Tennessee, by the Defense Special Weapons Agency. The full facility consists of 16 modules. Two full power modules (DM1 and DM2) have been built to verify the DECADE design at Physics International. Each module consists of a 570 kJ Marx generator that pulse charges a water transfer capacitor. The transfer capacitor discharges into a water output line through an array of 6 parallel triggered gas switches. The water output line then pulse charges the inductive store/opening switch pulse compression stage. When the opening switch opens, the inductive store discharges into an electron beam bremsstrahlung diode load. The initial testing of the DM1 module has been completed. The electrical design of the module will be presented, including circuit modeling results. The test data from a module will be compared to the modeling results. This test data, including reproducibility and timing accuracy, was used to predict the output from the full system of 16 modules and a subset of 4 unit modules (DECADE Quad). One option under consideration is to deploy a DECADE Quad at the testing center in Tennessee prior to the full 16 module system. The design sketch of the DECADE Quad and the predicted output based on the modeling and the demonstrated module performance is given. (author). 11 figs., 11 refs

  19. Calibration of decadal ensemble predictions (United States)

    Pasternack, Alexander; Rust, Henning W.; Bhend, Jonas; Liniger, Mark; Grieger, Jens; Müller, Wolfgang; Ulbrich, Uwe


    Decadal climate predictions are of great socio-economic interest due to the corresponding planning horizons of several political and economic decisions. Due to uncertainties of weather and climate, forecasts (e.g. due to initial condition uncertainty), they are issued in a probabilistic way. One issue frequently observed for probabilistic forecasts is that they tend to be not reliable, i.e. the forecasted probabilities are not consistent with the relative frequency of the associated observed events. Thus, these kind of forecasts need to be re-calibrated. While re-calibration methods for seasonal time scales are available and frequently applied, these methods still have to be adapted for decadal time scales and its characteristic problems like climate trend and lead time dependent bias. Regarding this, we propose a method to re-calibrate decadal ensemble predictions that takes the above mentioned characteristics into account. Finally, this method will be applied and validated to decadal forecasts from the MiKlip system (Germany's initiative for decadal prediction).

  20. Decadal climate prediction (project GCEP). (United States)

    Haines, Keith; Hermanson, Leon; Liu, Chunlei; Putt, Debbie; Sutton, Rowan; Iwi, Alan; Smith, Doug


    Decadal prediction uses climate models forced by changing greenhouse gases, as in the International Panel for Climate Change, but unlike longer range predictions they also require initialization with observations of the current climate. In particular, the upper-ocean heat content and circulation have a critical influence. Decadal prediction is still in its infancy and there is an urgent need to understand the important processes that determine predictability on these timescales. We have taken the first Hadley Centre Decadal Prediction System (DePreSys) and implemented it on several NERC institute compute clusters in order to study a wider range of initial condition impacts on decadal forecasting, eventually including the state of the land and cryosphere. The eScience methods are used to manage submission and output from the many ensemble model runs required to assess predictive skill. Early results suggest initial condition skill may extend for several years, even over land areas, but this depends sensitively on the definition used to measure skill, and alternatives are presented. The Grid for Coupled Ensemble Prediction (GCEP) system will allow the UK academic community to contribute to international experiments being planned to explore decadal climate predictability.

  1. Decadal Changes in Surface Radiative Fluxes (United States)

    Wild, M.


    Recent evidence suggests that radiative fluxes incident at the Earth surface are not stable over time but undergo significant changes on decadal timescales. This is not only found in the thermal spectral range, where an increase in the downwelling flux is expected with the increasing greenhouse effect, but also in the solar range. Observations suggest that surface solar radiation, after decades of decline ("global dimming"), reversed into a "brightening" since the mid-1980s at widespread locations. This presentation gives an update on recent investigations related to the decadal variations in these fluxes, based on both observational and modeling approaches. Updated observational data, archived at the Global Energy Balance Archive (GEBA) at ETH Zurich, suggest a continuation of surface solar brightening beyond the year 2000 at numerous locations, yet less pronounced and coherent than during the 1990s, with more regions with no clear changes or declines. Current global climate models as used in the IPCC-AR4 report typically do not reproduce the observed decadal variations to their full extent. Modeling attempts to improve this situation are under way at ETH, based on a global climate model which includes a sophisticated interactive treatment of aerosol and cloud microphysics (ECHAM5-HAM). Further the impact of the decadal changes in surface radiative forcings on different aspects of the global climate system and climate change is discussed, such as 20th century day- and nighttime warming, evapotranspiration changes and the varying intensity of the hydrological cycle as well as the terrestrial carbon cycle. Selected related references: Wild, M., and Co-authors, 2005: From dimming to brightening: Decadal changes in solar radiation at the Earth's surface. Science, 308, 847-850 Wild, M., 2007: Decadal changes in surface radiative fluxes and their importance in the context of global climate change, in: Climate Variability and Extremes during the Past 100 years, Advances

  2. Decadal sea-level changes in the Indian Ocean (United States)

    Gangan, Nidheesh; Vialard, Jerome; Lengaingne, Matthieu; Izumo, Takeshi; Alakkatt, Unnikrishnan


    While the Interdecadal Pacific Oscillation (IPO) has been identified as the main driver of natural decadal sea-level variations in the Pacific, Indian Ocean natural decadal sea-level variability remains a largely uncharted territory. In this study, we analyse Indian Ocean natural decadal sea-level variations from a large set of observational products, CMIP3 and CMIP5 pre-industrial simulations. The various observational products display very consistent patterns of decadal sea-level variability in the Pacific, but not in the Indian Ocean, most likely because of sparse observational coverage in the IO. In contrast, almost all CMIP simulations display two very consistent patterns of Indian Ocean decadal sea-level variability, which explain a large part of the total sea-level variance in this basin. The first mode consists of a dipolar sea-level pattern, with negative signals in the eastern Indian Ocean from the west coast of Australia to the northern Bay of Bengal and positive signals northeast of Madagascar. This mode is largely driven by the wind variability related to the decadal variations of the Indian Ocean Dipole, which is partly independent from decadal climate variability in the tropical Pacific. The second mode is completely independent from decadal Pacific variability, and consists of a broad sea-level pattern east of Madagascar. This mode is excited by decadal wind variations in the subtropical Indian Ocean, most likely associated with fluctuations of the Mascarene high. The two decadal modes identified in CMIP models are broadly consistent with those deduced from the relatively short altimeter dataset or from the longer ORA reanalysis. Sea-level reconstructions generally reproduce the dipolar mode but do not capture the decadal sea-level variability east of Madagascar, presumably because of the absence of long tide-gauge records in this region. This study hence illustrates that CMIP simulations can provide some guidance for identifying robust modes of

  3. The International Lunar Decade Declaration (United States)

    Beldavs, V.; Foing, B.; Bland, D.; Crisafulli, J.


    The International Lunar Decade Declaration was discussed at the conference held November 9-13, 2014 in Hawaii "The Next Giant Leap: Leveraging Lunar Assets for Sustainable Pathways to Space" - and accepted by a core group that forms the International Lunar Decade Working Group (ILDWG) that is seeking to make the proposed global event and decade long process a reality. The Declaration will be updated from time to time by members of the ILDWreflecting new knowledge and fresh perspectives that bear on building a global consortium with a mission to progress from lunar exploration to the transformation of the Moon into a wealth gene rating platform for the expansion of humankind into the solar system. When key organizations have endorsed the idea and joined the effort the text of the Declaration will be considered final. An earlier International Lunar Decade proposal was issued at the 8th ICEUM Conference in 2006 in Beijing together with 13 specific initiatives for lunar exploration[1,2,3]. These initiatives have been largely implemented with coordination among the different space agencies involved provided by the International Lunar Exploration Working Group[2,3]. The Second International Lunar Decade from 2015 reflects current trends towards increasing involvement of commercial firms in space, particularly seeking opportunities beyond low Earth orbit. The central vision of the International Lunar Decade is to build the foundations for a sustainable space economy through international collaboration concurrently addressing Lunar exploration and building a shared knowledge base;Policy development that enables collabo rative research and development leading to lunar mining and industrial and commercial development;Infrastructure on the Moon and in cislunar space (communications, transport, energy systems, way-stations, other) that reduces costs, lowers risks and speeds up the time to profitable operations;Enabling technologies

  4. Strong interactions - quark models

    International Nuclear Information System (INIS)

    Goto, M.; Ferreira, P.L.


    The variational method is used for the PSI and upsilon family spectra reproduction from the quark model, through several phenomenological potentials, viz.: linear, linear plus coulomb term and logarithmic. (L.C.) [pt

  5. The UN Decade for Women. (United States)

    Reynolds, Nancy C.


    The events of the UN Decade for Women are reviewed. The Third World Conference on Women, to be held in 1985, is seen as a forum to assess progress achieved and to look to the future needs and potential of women throughout the world. (MLW)

  6. Blended Learning over Two Decades (United States)

    Zhonggen, Yu; Yuexiu, Zhejiang


    The 21st century has witnessed vast amounts of research into blended learning since the conception of online learning formed the possibility of blended learning in the early 1990s. The theme of this paper is blended learning in mainstream disciplinary communities. In particular, the paper reports on findings from the last two decades which looked…

  7. IRIN marks its first decade

    Directory of Open Access Journals (Sweden)

    Joanne Clark


    Full Text Available The Integrated Regional Information Networks (IRIN has come a long way from its initial coverage of three countries. A decade later, IRIN is a multimedia news service producing daily and analytical reports, news footage and radio broadcasts spanning Africa, Asia and the Middle East.

  8. Radar efficiency and the calculation of decade-long PMSE backscatter cross-section for the Resolute Bay VHF radar

    Directory of Open Access Journals (Sweden)

    N. Swarnalingam


    Full Text Available The Resolute Bay VHF radar, located in Nunavut, Canada (75.0° N, 95.0° W and operating at 51.5 MHz, has been used to investigate Polar Mesosphere Summer Echoes (PMSE since 1997. PMSE are a unique form of strong coherent radar echoes, and their understanding has been a challenge to the scientific community since their discovery more than three decades ago. While other high latitude radars have recorded strong levels of PMSE activities, the Resolute Bay radar has observed relatively lower levels of PMSE strengths. In order to derive absolute measurements of PMSE strength at this site, a technique is developed to determine the radar efficiency using cosmic (sky noise variations along with the help of a calibrated noise source. VHF radars are only rarely calibrated, but determination of efficiency is even less common. Here we emphasize the importance of efficiency for determination of cross-section measurements. The significant advantage of this method is that it can be directly applied to any MST radar system anywhere in the world as long as the sky noise variations are known. The radar efficiencies for two on-site radars at Resolute Bay are determined. PMSE backscatter cross-section is estimated, and decade-long PMSE strength variations at this location are investigated. It was noticed that the median of the backscatter cross-section distribution remains relatively unchanged, but over the years a great level of variability occurs in the high power tail of the distribution.

  9. Strongly Correlated Topological Insulators (United States)


    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  10. Decadal Monsoon-ENSO Relationships Reexamined (United States)

    Yun, Kyung-Sook; Timmermann, Axel


    The strength of the El Niño-Southern Oscillation (ENSO)-Indian summer monsoon rainfall (ISMR) relationship shows considerable decadal fluctuations, which have been previously linked to low-frequency climatic processes such as shifts in ENSO's center of action or the Atlantic Multidecadal Oscillation. However, random variability can also cause similar variations in the relationship between climate phenomena. Here we propose a statistical test to determine whether the observed time-evolving correlations between ENSO and ISMR are different from those expected from a simple stochastic null hypothesis model. The analysis focuses on the time evolution of moving correlations, their expected variance, and probabilities for rapid transitions. The results indicate that the time evolution of the observed running correlation between these climate modes is indistinguishable from a system in which the ISMR signal can be expressed as a stochastically perturbed ENSO signal. This challenges previous deterministic interpretations. Our results are further corroborated by the analysis of climate model simulations.

  11. Strong Cosmic Censorship (United States)

    Isenberg, James


    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  12. Connecting Complex Processes: A Decade of Research on Immigrant Families (United States)

    Glick, Jennifer E.


    This review examines research on immigrant families in the United States from the past decade from multiple disciplinary perspectives. This work has used variations on assimilation and acculturation perspectives. In the case of the assimilation perspectives, the focus has largely been on family formation, whereas research using acculturation…

  13. Over the past decades, the Cape anchovy Engraulis capensis has ...

    African Journals Online (AJOL)


    Over the past decades, the Cape anchovy Engraulis capensis has supported a large purse-seine fishery in. South Africa. Management of the fishery is compli- cated by large interannual variations in recruitment, a phenomenon common to many pelagic fish species. (Lluch-Belda et al.1989). Understanding this vari- ability is ...

  14. The summer North Atlantic Oscillation (SNAO) variability on decadal to paleoclimate time scales (United States)

    Linderholm, H. W.; Folland, C. K.; Zhang, P.; Gunnarson, B. E.; Jeong, J. H.; Ren, H.


    The summer North Atlantic Oscillation (SNAO), strongly related to the latitude of the North Atlantic and European summer storm tracks, exerts a considerable influence on European summer climate variability and extremes. Here we extend the period covered by the SNAO from July and August to June, July and August (JJA). As well as marked interannual variability, the JJA SNAO has shown a large inter-decadal change since the 1970s. Decadally averaged, there has been a change from a very positive to a rather negative SNAO phase. This change in SNAO phase is opposite in sign from that expected by a number of climate models under enhanced greenhouse forcing by the late twenty first century. It has led to noticeably wetter summers in North West Europe in the last decade. On interannual to multidecadal timescales, SNAO variability is linked to variations in North Atlantic sea surface temperature (SST): observations and models indicate an association between the Atlantic Multi-decadal Oscillation (AMO) where the cold (warm) phase of the AMO corresponds a positive (negative) phase of the SNAO. Observations also indicate a link with SST in the Gulf Stream region of the North Atlantic where, particularly on decadal time scales, SST warming may favour a more positive phase of the SNAO. Influences of Arctic climate change on North Atlantic and European atmospheric circulation may also exist, particularly reduced sea ice coverage, perhaps favouring the negative phase of the SNAO. A new tree-ring data based JJA SNAO reconstruction extending over the last millennium, as well as climate model output for the same period, enables us to examine the influence of North Atlantic SST and Arctic sea-ice coverage, as well as SNAO impacts on European summer climate, in a long-term, pre-industrial context.

  15. Strong Arcwise Connectedness


    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana


    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  16. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio


    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  17. Chernobyl: lessons of the decade

    International Nuclear Information System (INIS)

    Tsaregorodtsev, A.D.


    The Chernobyl accident led to a drastic increase the incidents of thyroid cancer in children living at territories contaminated with radionuclides. The incidents of hemoblastoses which are etiologically closely related to radiation did not change after the incident. The lessons of the decade that passed since the accident necessitate measures aimed at alleviation of the medical consequences of the accident which are to be implemented for many years. The program of such measures should be based on a strictly scientific evaluation of each factor, that will be conductive to a most adequate state financing of this work [ru

  18. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.


    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  19. The LUVOIR Decadal Mission Concept (United States)

    Arney, G. N.; Crooke, J.; Domagal-Goldman, S. D.; Fischer, D.; Peterson, B.; Schmidt, B. E.; Stdt, T. L. T.


    The Large UV-Optical-Infrared (LUVOIR) Surveyor is one of four mission concepts being studied by NASA in preparation for the 2020 Astrophysics Decadal Survey. LUVOIR is a general-purpose space-based observatory with a large aperture in the 8-16 m range and a total bandpass spanning from the far-UV to the near-infrared. This observatory will enable revolutionary new studies in many areas of astronomy, including planetary science within and beyond our Solar System. Because LUVOIR is being considered for the next decadal survey, it must be capable of advancing our understanding of astronomical targets, including exoplanets, far beyond what will be achieved by the next two decades of observations from other space- or ground-based facilities. This means that the mission must move past planet detection, which is happening now with Kepler and ground-based measurements and will continue with TESS (Transiting Exoplanet Survey Satellite) and WFIRST (Wide Field Infrared Survey Telescope). It must also move beyond the chemical characterization of gas giants, which has begun with observations from Spitzer, Hubble, and ground-based telescopes and will greatly advances with the upcoming JWST (James Webb Space Telescope) and WFIRST coronagraph. Therefore, one of LUVOIR's main science objectives will be to directly image rocky Earth-sized planets in the habitable zones of other stars, measure their spectra, analyze the chemistry of their atmospheres, and obtain information about their surfaces. Such observations will allow us to evaluate these worlds' habitability and potential for life. We will review the specific observational strategies needed for astrobiological assessments of exoplanetary environments, including the wavelength range and spectral resolution required for these habitability analyses and biosignature searches. Further, we will discuss how the observational requirements to make measurements of "Earthlike" worlds will allow high-quality observations of a wide

  20. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin


    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  1. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.


    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  2. A New Decade of Vaccines

    LENUS (Irish Health Repository)

    Murphy, JFA


    The call for a new decade of vaccines was made in December 2010. The aims are to secure the further discovery, development and delivery of vaccination. The first challenge is the acquisition of funds for the research and development of 20 new vaccines1. The Gates Foundation has pledged $10 billion for this venture. The other major players are WHO, UNICEF and the US National Institute of Allergy and Infectious Diseases. The top priorities are TB, AIDS and Malaria. It is hoped that a Malaria vaccine will available in 3 years. The ambitious target of saving the lives of over 7 million children has been set. The programme must also address the need for vaccines in insulin dependent diabetes, cancers and degenerative diseases2.

  3. Decadal opportunities for space architects (United States)

    Sherwood, Brent


    A significant challenge for the new field of space architecture is the dearth of project opportunities. Yet every year more young professionals express interest to enter the field. This paper derives projections that bound the number, type, and range of global development opportunities that may be reasonably expected over the next few decades for human space flight (HSF) systems so those interested in the field can benchmark their goals. Four categories of HSF activity are described: human Exploration of solar system bodies; human Servicing of space-based assets; large-scale development of space Resources; and Breakout of self-sustaining human societies into the solar system. A progressive sequence of capabilities for each category starts with its earliest feasible missions and leads toward its full expression. The four sequences are compared in scale, distance from Earth, and readiness. Scenarios hybridize the most synergistic features from the four sequences for comparison to status quo, government-funded HSF program plans. Finally qualitative, decadal, order-of-magnitude estimates are derived for system development needs, and hence opportunities for space architects. Government investment towards human planetary exploration is the weakest generator of space architecture work. Conversely, the strongest generator is a combination of three market drivers: (1) commercial passenger travel in low Earth orbit; (2) in parallel, government extension of HSF capability to GEO; both followed by (3) scale-up demonstration of end-to-end solar power satellites in GEO. The rich end of this scale affords space architecture opportunities which are more diverse, complex, large-scale, and sociologically challenging than traditional exploration vehicle cabins and habitats.

  4. Food Price Volatility and Decadal Climate Variability (United States)

    Brown, M. E.


    The agriculture system is under pressure to increase production every year as global population expands and more people move from a diet mostly made up of grains, to one with more meat, dairy and processed foods. Weather shocks and large changes in international commodity prices in the last decade have increased pressure on local food prices. This paper will review several studies that link climate variability as measured with satellite remote sensing to food price dynamics in 36 developing countries where local monthly food price data is available. The focus of the research is to understand how weather and climate, as measured by variations in the growing season using satellite remote sensing, has affected agricultural production, food prices and access to food in agricultural societies. Economies are vulnerable to extreme weather at multiple levels. Subsistence small holders who hold livestock and consume much of the food they produce are vulnerable to food production variability. The broader society, however, is also vulnerable to extreme weather because of the secondary effects on market functioning, resource availability, and large-scale impacts on employment in trading, trucking and wage labor that are caused by weather-related shocks. Food price variability captures many of these broad impacts and can be used to diagnose weather-related vulnerability across multiple sectors. The paper will trace these connections using market-level data and analysis. The context of the analysis is the humanitarian aid community, using the guidance of the USAID Famine Early Warning Systems Network and the United Nation's World Food Program in their response to food security crises. These organizations have worked over the past three decades to provide baseline information on food production through satellite remote sensing data and agricultural yield models, as well as assessments of food access through a food price database. Econometric models and spatial analysis are used

  5. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.


    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  6. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.


    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  7. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia


    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  8. Lyme disease: the next decade (United States)

    Stricker, Raphael B; Johnson, Lorraine


    Although Lyme disease remains a controversial illness, recent events have created an unprecedented opportunity to make progress against this serious tick-borne infection. Evidence presented during the legally mandated review of the restrictive Lyme guidelines of the Infectious Diseases Society of America (IDSA) has confirmed the potential for persistent infection with the Lyme spirochete, Borrelia burgdorferi, as well as the complicating role of tick-borne coinfections such as Babesia, Anaplasma, Ehrlichia, and Bartonella species associated with failure of short-course antibiotic therapy. Furthermore, renewed interest in the role of cell wall-deficient (CWD) forms in chronic bacterial infection and progress in understanding the molecular mechanisms of biofilms has focused attention on these processes in chronic Lyme disease. Recognition of the importance of CWD forms and biofilms in persistent B. burgdorferi infection should stimulate pharmaceutical research into new antimicrobial agents that target these mechanisms of chronic infection with the Lyme spirochete. Concurrent clinical implementation of proteomic screening offers a chance to correct significant deficiencies in Lyme testing. Advances in these areas have the potential to revolutionize the diagnosis and treatment of Lyme disease in the coming decade. PMID:21694904

  9. Lyme disease: the next decade

    Directory of Open Access Journals (Sweden)

    Raphael B Stricker


    Full Text Available Raphael B Stricker, Lorraine JohnsonInternational Lyme and Associated Diseases Society, Bethesda, MD, USAAbstract: Although Lyme disease remains a controversial illness, recent events have created an unprecedented opportunity to make progress against this serious tick-borne infection. Evidence presented during the legally mandated review of the restrictive Lyme guidelines of the Infectious Diseases Society of America (IDSA has confirmed the potential for persistent infection with the Lyme spirochete, Borrelia burgdorferi, as well as the complicating role of tick-borne coinfections such as Babesia, Anaplasma, Ehrlichia, and Bartonella species associated with failure of short-course antibiotic therapy. Furthermore, renewed interest in the role of cell wall-deficient (CWD forms in chronic bacterial infection and progress in understanding the molecular mechanisms of biofilms has focused attention on these processes in chronic Lyme disease. Recognition of the importance of CWD forms and biofilms in persistent B. burgdorferi infection should stimulate pharmaceutical research into new antimicrobial agents that target these mechanisms of chronic infection with the Lyme spirochete. Concurrent clinical implementation of proteomic screening offers a chance to correct significant deficiencies in Lyme testing. Advances in these areas have the potential to revolutionize the diagnosis and treatment of Lyme disease in the coming decade.Keywords: Lyme disease, Borrelia burgdorferi, L-forms, cysts, biofilms, proteomics

  10. GESAMP: Two decades of accomplishments

    International Nuclear Information System (INIS)

    Windom, H.L


    Many of the uses of the oceans by society may lead potentially to the degradation of the marine environment. Human activities on land lead to the inadvertent or deliberate input of contaminants to the oceans which also may result in marine environmental degradation on local, regional or global scales. Potential impacts on the marine environment of human activities on land and the potential conflicts of society's utilization of the oceans require ongoing global evaluation from a multidisciplinary scientific perspective. This has been recognized for some time by the community of United Nations organizations, eight of which jointly sponsor an interdisciplinary groups of scientists to provide independent advice on existing and potential marine pollution problems. This Group of Experts on the Scientific Aspects of Marine Pollution (GESAMP) was formed two decades ago to serve as a mechanism for encouraging coordination, collaboration and harmonization of activities related to marine pollution of common interest to the co-sponsoring bodies. More recently, GESAMP has expanded its programme to include consideration of the impacts of other human activities, such as coastal development, on the marine environment. The purpose of this booklet is to briefly describe what GESAMP is, how it operates and what it accomplishes

  11. Physics of Strongly Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kraeft, Wolf-Dietrich [Universitat Rostock (Germany)


    Strongly coupled plasmas (or non-ideal plasmas) are multi-component charged many-particle systems, in which the mean value of the potential energy of the system is of the same order as or even higher than the mean value of the kinetic energy. The constituents are electrons, ions, atoms and molecules. Dusty (or complex) plasmas contain still mesoscopic (multiply charged) particles. In such systems, the effects of strong coupling (non-ideality) lead to considerable deviations of physical properties from the corresponding properties of ideal plasmas, i.e., of plasmas in which the mean kinetic energy is essentially larger than the mean potential energy. For instance, bound state energies become density dependent and vanish at higher densities (Mott effect) due to the interaction of the pair with the surrounding particles. Non-ideal plasmas are of interest both for general scientific reasons (including, for example, astrophysical questions), and for technical applications such as inertially confined fusion. In spite of great efforts both experimentally and theoretically, satisfactory information on the physical properties of strongly coupled plasmas is not at hand for any temperature and density. For example, the theoretical description of non-ideal plasmas is possible only at low densities/high temperatures and at extremely high densities (high degeneracy). For intermediate degeneracy, however, numerical experiments have to fill the gap. Experiments are difficult in the region of 'warm dense matter'. The monograph tries to present the state of the art concerning both theoretical and experimental attempts. It mainly includes results of the work performed in famous Russian laboratories in recent decades. After outlining basic concepts (chapter 1), the generation of plasmas is considered (chapter 2, chapter 3). Questions of partial (chapter 4) and full ionization (chapter 5) are discussed including Mott transition and Wigner crystallization. Electrical and

  12. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso


    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  13. Action learning across the decades. (United States)

    Eason, Ken


    Purpose The purpose of this paper is to explore how action learning concepts were used in two healthcare projects undertaken many decades apart. The specific purpose in both cases was to examine how action learning can contribute to shared learning across key stakeholders in a complex socio-technical system. In each case study, action learning supported joint design programmes and the sharing of perspectives about the complex system under investigation. Design/methodology/approach Two action learning projects are described: first, the Hospital Internal Communications (HIC) project led by Reg Revans in the 1960s. Senior staff in ten London hospitals formed action learning teams to address communication issues. Second, in the Better Outcomes for People with Learning Disabilities: Transforming Care (BOLDTC) project, videoconferencing equipment enabled people with learning disabilities to increase their opportunities to communicate. A mutual learning process was established to enable stakeholders to explore the potential of the technical system to improve individual care. Findings The HIC project demonstrated the importance of evidence being shared between team members and that action had to engage the larger healthcare system outside the hospital. The BOLDTC project confirmed the continuing relevance of action learning to healthcare today. Mutual learning was achieved between health and social care specialists and technologists. Originality/value This work draws together the socio-technical systems tradition (considering both social and technical issues in organisations) and action learning to demonstrate that complex systems development needs to be undertaken as a learning process in which action provides the fuel for learning and design.

  14. A decade of Radiometallurgy Division

    International Nuclear Information System (INIS)

    Ganguly, C.; Bahl, J.K.


    The main thrust of the Research and Development (R and D) activities of the Radiometallurgy Division of the Bhabha Atomic Research Centre is on (1) R and D work and production of plutonium bearing nuclear fuels, (2) Post-Irradiation Examination (PIE) of fuels and structural materials, and (3) failure analysis of power reactor components. The main activities and achievements of the Division during the decade beginning from April 1978 are highlighted and the new thrust areas oriented towards installing a series of 235 MWe and 500 MWe PHWR units and prototype fast breeder reactor (PFBR) of 500 MWe capacity during the next 15 years are described in brief. The major achievements during last ten years are: (1) development and irradiation testing of mixed uranium plutonium oxide (MOX), as an alternative fuel for boiling water reactors at Tarapur, (2) setting up of a 10 tons/year pilot plant for fabrication of oxide fuels and technical support for setting up such plants, (3) development and production of plutonium rich, advanced mixed uranium plutonium monocarbide driver fuel for the Fast Breeder Test Reactor comm issioned at Kalpakkam, (4) development and fabrication of Al- 233 U plate fuel elements for KAMINI reactor, (5) PIE of fuel elements from Indian reactors in operation, (6) failure analysis of reactor components, and (7) in-pile performance analysis of power reactor structural materials. A list of publications during 1978-88 by the scientists of the Division is given at the end. The publications are listed under the headings: (1) fuels, (2) non-destructive evaluation, (3) engineering development, (4) welding development, (5) characterization and property evaluation, and (6) post irradiation examination. The entire text is illustrated with a number of diagrams and photographs - many of them coloured . (M.G.B.)

  15. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  16. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim


    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  17. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.


    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  18. XMM-Newton: The Next Decade (United States)

    Ness, Jan-Uwe


    The recent generation of high energy observatories has enabled unprecedented progress to be made in our understanding of astrophysics in the X-ray domain. Current technical evaluations suggest that the XMM-Newton spacecraft and its scientific instruments may continue to provide first class X-ray observations well into the next decade. Other X-ray missions are planned to be launched soon, including Astro-H and e-ROSITA. Coupled with new ground-based developments, this will open up new exciting opportunities for multi-wavelength and follow-up observations, to which XMM-Newton is ideally placed to play a major role. This workshop will summarise the state of our current knowledge derived from X-ray astrophysics. We will discuss some of the major achievements over the past years, and identify a set of fundamental questions still to be addressed. Within this context a primary aim of the workshop will be to define the key scientific topics which will have the highest scientific importance and impact. We will seek to identify observing programs of maximum long-term value to the entire astronomical community. Many of these programs are likely to require large amounts of observing time on only a few carefully selected targets or sky areas. We strongly encourage innovative ideas for applications, and the formation of well organised major collaborations.

  19. Decadal Variability and Temperature Trends in the Middle Atmosphere From Historical Rocketsonde Data (United States)

    Dunkerton, Timothy J.


    Observational studies were performed using historical rocketsonde data to investigate long-term temperature trends, solar-cycle variations, and interactions between tropical and extratropical latitudes in the middle atmosphere. Evidence from tropical, subtropical, and midlatitude North American rocketsonde stations indicated a consistent downward trend over 25 years, with a solar cycle component superposed. The trend is about -1.4 to -2.0 K per decade and the amplitude of the decadal oscillation is about 1.1 K. Prior to trend derivation it was necessary for us to correct temperatures for aerodynamic heating in the early years. The empirically derived correction profile agrees well with a theoretical profile of Krumins and Lyons. A study was also performed of the correlation between equatorial winds and north polar temperatures in winter, showing that the entire stratospheric wind profile near the equator -- including the quasi-biennial oscillation (QBO) and stratopause semiannual oscillation (SAO) -- is important to the extratropical flow, not merely the QBO component as previously thought. A strong correlation was discovered between winter polar temperatures and equatorial winds in the upper stratosphere during the preceding September, suggesting a role for the second cycle of the SAO.

  20. Evaluation of decadal hindcasts using satellite simulators (United States)

    Spangehl, Thomas; Mazurkiewicz, Alex; Schröder, Marc


    The evaluation of dynamical ensemble forecast systems requires a solid validation of basic processes such as the global atmospheric water and energy cycle. The value of any validation approach strongly depends on the quality of the observational data records used. Current approaches utilize in situ measurements, remote sensing data and reanalyses. Related data records are subject to a number of uncertainties and limitations such as representativeness, spatial and temporal resolution and homogeneity. However, recently several climate data records with known and sufficient quality became available. In particular, the satellite data records offer the opportunity to obtain reference information on global scales including the oceans. Here we consider the simulation of satellite radiances from the climate model output enabling an evaluation in the instrument's parameter space to avoid uncertainties stemming from the application of retrieval schemes in order to minimise uncertainties on the reference side. Utilizing the CFMIP Observation Simulator Package (COSP) we develop satellite simulators for the Tropical Rainfall Measuring Mission precipitation radar (TRMM PR) and the Infrared Atmospheric Sounding Interferometer (IASI). The simulators are applied within the MiKlip project funded by BMBF (German Federal Ministry of Education and Research) to evaluate decadal climate predictions performed with the MPI-ESM developed at the Max Planck Institute for Meteorology. While TRMM PR enables the evaluation of the vertical structure of precipitation over tropical and sub-tropical areas, IASI is used to support the global evaluation of clouds and radiation. In a first step the reliability of the developed simulators needs to be explored. The simulation of radiances in the instrument space requires the generation of sub-grid scale variability from the climate model output. Furthermore, assumptions are made to simulate radiances such as, for example, the distribution of different

  1. Fundamental Structure of Matter and Strong Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Jian-Ping Chen


    More than 99% of the visible matter in the universe are the protons and neutrons. Their internal structure is mostly governed by the strong interaction. Understanding their internal structure in terms of fundamental degrees-of-freedom is one of the most important subjects in modern physics. Worldwide efforts in the last few decades have lead to numerous surprises and discoveries, but major challenges still remain. An overview of the progress will be presented with a focus on the recent studies of the proton and neutron's electromagnetic and spin structure. Future perspectives will be discussed.

  2. Multi-decadal 40- to 60-year cycles of precipitation variability in Chile (South America) and their relationship to the AMO and PDO signals (United States)

    Valdés-Pineda, Rodrigo; Cañón, Julio; Valdés, Juan B.


    High-frequency components of precipitation variability have been an important focus of study during the last few decades in Chile. Low-frequency variations, on the other hand, have received less attention, especially in association with multi-decadal cycles that can affect variability trends of precipitation in the long term. This study analyzes these low-frequency patterns of precipitation in Chile (>30 years), and their relationship to global Sea Surface Temperatures (SSTs), with special focus on associations with the Pacific Decadal Oscillation (PDO) and the Atlantic Multi-decadal Oscillation (AMO) indices. Singular Spectrum Analysis (SSA) and its Multi-Channel version (MSSA) techniques were applied to a dataset containing long instrumental records of monthly precipitation aggregated yearly and seasonally. The relationships between the low-frequency variability of precipitation and the PDO are significant to the north of the country, whereas connections with the AMO are significant to the north and also to the south. This is also evident from the global spatial correlation analysis of low-frequency precipitation modes and SSTs, where the southernmost station shows a strong relationship with the Atlantic Ocean. We conclude that a significant multi-decadal precipitation cycle between 40 and 60 years is evident at the rain gauges located in the subtropical and extratropical regions of Chile. This low-frequency variability seems to be largely linked to PDO and AMO modulation.

  3. Variability and predictability of decadal mean temperature and precipitation over China in the CCSM4 last millennium simulation (United States)

    Ying, Kairan; Frederiksen, Carsten S.; Zheng, Xiaogu; Lou, Jiale; Zhao, Tianbao


    The modes of variability that arise from the slow-decadal (potentially predictable) and intra-decadal (unpredictable) components of decadal mean temperature and precipitation over China are examined, in a 1000 year (850-1850 AD) experiment using the CCSM4 model. Solar variations, volcanic aerosols, orbital forcing, land use, and greenhouse gas concentrations provide the main forcing and boundary conditions. The analysis is done using a decadal variance decomposition method that identifies sources of potential decadal predictability and uncertainty. The average potential decadal predictabilities (ratio of slow-to-total decadal variance) are 0.62 and 0.37 for the temperature and rainfall over China, respectively, indicating that the (multi-)decadal variations of temperature are dominated by slow-decadal variability, while precipitation is dominated by unpredictable decadal noise. Possible sources of decadal predictability for the two leading predictable modes of temperature are the external radiative forcing, and the combined effects of slow-decadal variability of the Arctic oscillation (AO) and the Pacific decadal oscillation (PDO), respectively. Combined AO and PDO slow-decadal variability is associated also with the leading predictable mode of precipitation. External radiative forcing as well as the slow-decadal variability of PDO are associated with the second predictable rainfall mode; the slow-decadal variability of Atlantic multi-decadal oscillation (AMO) is associated with the third predictable precipitation mode. The dominant unpredictable decadal modes are associated with intra-decadal/inter-annual phenomena. In particular, the El Niño-Southern Oscillation and the intra-decadal variability of the AMO, PDO and AO are the most important sources of prediction uncertainty.

  4. Rings Research in the Next Decade (United States)

    Burns, J. A.; Tiscareno, M. S.


    The study of planetary ring systems forms a key component of planetary science for several reasons: 1) The evolution and current states of planets and their satellites are affected in many ways by rings, while 2) conversely, properties of planets and moons and other solar system populations are revealed by their effects on rings; 3) highly structured and apparently delicate ring systems may be bellwethers, constraining various theories of the origin and evolution of their entire planetary system; and finally, 4) planetary rings provide an easily observable analogue to other astrophysical disk systems, enabling real “ground truth” results applicable to disks much more remote in space and/or time, including proto-planetary disks, circum-stellar disks, and even galaxies. Significant advances have been made in rings science in the past decade. The highest-priority rings research recommendations of the last Planetary Science Decadal Survey were to operate and extend the Cassini orbiter mission at Saturn; this has been done with tremendous success, accounting for much of the progress made on key science questions, as we will describe. Important progress in understanding the rings of Saturn and other planets has also come from Earth-based observational and theoretical work, again as prioritized by the last Decadal Survey. However, much important work remains to be done. At Saturn, the Cassini Solstice Mission must be brought to a successful completion. Priority should also be placed on sending spacecraft to Neptune and/or Uranus, now unvisited for more than 20 years. At Jupiter and Pluto, opportunities afforded by visiting spacecraft capable of studying rings should be exploited. On Earth, the need for continued research and analysis remains strong, including in-depth analysis of rings data already obtained, numerical and theoretical modeling work, laboratory analysis of materials and processes analogous to those found in the outer solar system, and continued Earth

  5. <strong>Variation in oxalate and oxalate decarboxylase strong>>production by six species of brown and white rot fungistrong>

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin

    cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary......  Oxalic acid (C2O4H2), the strongest of the organic acids is produced by both brown and white rot decay fungi and has been connected to various aspects of brown- and white rot decay including the Fenton reaction (Green and Highley, 1997; Munir et al.,2001). Oxalic acid is secreted into the wood...

  6. Aperture averaging in strong oceanic turbulence (United States)

    Gökçe, Muhsin Caner; Baykal, Yahya


    Receiver aperture averaging technique is employed in underwater wireless optical communication (UWOC) systems to mitigate the effects of oceanic turbulence, thus to improve the system performance. The irradiance flux variance is a measure of the intensity fluctuations on a lens of the receiver aperture. Using the modified Rytov theory which uses the small-scale and large-scale spatial filters, and our previously presented expression that shows the atmospheric structure constant in terms of oceanic turbulence parameters, we evaluate the irradiance flux variance and the aperture averaging factor of a spherical wave in strong oceanic turbulence. Irradiance flux variance variations are examined versus the oceanic turbulence parameters and the receiver aperture diameter are examined in strong oceanic turbulence. Also, the effect of the receiver aperture diameter on the aperture averaging factor is presented in strong oceanic turbulence.

  7. Renewable Electricity: Insights for the Coming Decade

    Energy Technology Data Exchange (ETDEWEB)

    Stark, Camila [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States); Pless, Jacquelyn [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States); Logan, Jeffrey [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States); Zhou, Ella [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States)


    A sophisticated set of renewable electricity (RE) generation technologies is now commercially available. Globally, RE captured approximately half of all capacity additions since 2011. The cost of RE is already competitive with fossil fuels in some areas around the world, and prices are anticipated to continue to decline over the next decade. RE options, led by wind and solar, are part of a suite of technologies and business solutions that are transforming electricity sectors around the world. Renewable deployment is expected to continue due to: increasingly competitive economics; favorable environmental characteristics such as low water use, and minimal local air pollution and greenhouse gas (GHG) emissions; complementary risk profiles when paired with natural gas generators; strong support from stakeholders. Despite this positive outlook for renewables, the collapse in global oil prices since mid-2014 and continued growth in natural gas supply in the United States--due to the development of low-cost shale gas--raise questions about the potential impacts of fossil fuel prices on RE. Today, oil plays a very minor role in the electricity sectors of most countries, so direct impacts on RE are likely to be minimal (except where natural gas prices are indexed on oil). Natural gas and RE generating options appear to be more serious competitors than oil and renewables. Low gas prices raise the hurdle for RE to be cost competitive. Additionally, although RE emits far less GHG than natural gas, both natural gas and RE offer the benefits of reducing carbon relative to coal and oil (see Section 4.1 for more detail on the GHG intensity of electricity technologies). However, many investors and decision makers are becoming aware of the complementary benefits of pairing natural gas and renewables to minimize risk of unstable fuel prices and maintain the reliability of electricity to the grid.

  8. Geomagnetic secular variation at the African observatories

    International Nuclear Information System (INIS)

    Haile, T.


    Geomagnetic data from ten observatories in the African continent with time series data length of more than three decades have been analysed. All-day annual mean values of the D, H and Z components were used to study secular variations in the African region. The residuals in D, H and Z components obtained after removing polynomial fits have been examined in relation to the sunspot cycle. The occurrence of the 1969-1970 worldwide geomagnetic impulse in each observatory is studied. It is found that the secular variation in the field can be represented for most of the observatories with polynomials of second or third degree. Departures from these trends are observed over the Southern African region where strong local magnetic anomalies have been observed. The residuals in the geomagnetic field components have been shown to exhibit parallelism with the periods corresponding to double solar cycle for some of the stations. A clear latitudinal distribution in the geomagnetic component that exhibits the 1969-70 jerk is shown. The jerk appears in the plots of the first differences in H for the southern most observatories of Hermanus, Hartebeesthoek, and Tsuemb, while the Z plots show the jerk for near equatorial and equatorial stations of Antananarivo, Luanda Belas, Bangui and Addis Ababa. There is some indication for this jerk in the first difference plots of D for the northern stations of M'Bour and Tamanrasset. The plots of D rather strongly suggest the presence of a jerk around 1980 at most of the stations. (author)

  9. On exterior variational calculus

    International Nuclear Information System (INIS)

    Aldrovandi, R.; Kraenkel, R.A.


    Exterior variational calculus is introduced through examples in field theory. It provides a very simple technique to decide on the existence of Lagrangians for given equations of motions and, in the case, to find them. Only local aspects are discussed but the analogy to exterior calculus on finite dimensional manifolds is complete, strongly suggesting its suitability to the study of topological aspects. (Author) [pt

  10. A Decade of Scholarship in Marketing Education (United States)

    Abernethy, Avery M.; Padgett, Daniel


    The teaching environment in business schools has changed dramatically over the last decade. But the last comprehensive review of the scholarship of teaching was conducted more than a decade ago. Where and from whom do the best practices for teaching originate today? To answer this question, the authors examine marketing education scholarship…

  11. Electromotive force in strongly compressible magnetohydrodynamic turbulence (United States)

    Yokoi, N.


    Variable density fluid turbulence is ubiquitous in geo-fluids, not to mention in astrophysics. Depending on the source of density variation, variable density fluid turbulence may be divided into two categories: the weak compressible (entropy mode) turbulence for slow flow and the strong compressible (acoustic mode) turbulence for fast flow. In the strong compressible turbulence, the pressure fluctuation induces a strong density fluctuation ρ ', which is represented by the density variance ( denotes the ensemble average). The turbulent effect on the large-scale magnetic-field B induction is represented by the turbulent electromotive force (EMF) (u': velocity fluctuation, b': magnetic-field fluctuation). In the usual treatment in the dynamo theory, the expression for the EMF has been obtained in the framework of incompressible or weak compressible turbulence, where only the variation of the mean density , if any, is taken into account. We see from the equation of the density fluctuation ρ', the density variance is generated by the large mean density variation ∂ coupled with the turbulent mass flux . This means that in the region where the mean density steeply changes, the density variance effect becomes relevant for the magnetic field evolution. This situation is typically the case for phenomena associated with shocks and compositional discontinuities. With the aid of the analytical theory of inhomogeneous compressible magnetohydrodynamic (MHD) turbulence, the expression for the turbulent electromotive force is investigated. It is shown that, among others, an obliqueness (misalignment) between the mean density gradient ∂ and the mean magnetic field B may contribute to the EMF as ≈χ B×∂ with the turbulent transport coefficient χ proportional to the density variance (χ ). This density variance effect is expected to strongly affect the EMF near the interface, and changes the transport properties of turbulence. In the case of an interface under the MHD slow

  12. Interannual and Decadal Variability of Summer Rainfall over South America (United States)

    Zhou, Jiayu; Lau, K.-M.


    Using the CPC (Climate Prediction Center) Merged Analysis of Precipitation product along with the Goddard Earth Observing System reanalysis and the Climate Analysis Center sea surface temperature (SST) data, we conduct a diagnostic study of the interannual and decadal scale variability of summer rainfall over South America. Results show three leading modes of rainfall variation identified with interannual, decadal, and long-term trend variability. Together, these modes explain more than half the total variance. The first mode is highly correlated with El Nino/southern oscillation (ENSO), showing severe drought over Northeast Brazil and copious rainfall over the Ecuador coast and the area of Uruguay-Southern Brazil in El Nino years. This pattern is attributed to the large scale zonal shift of the Walker circulation and local Hadley cell anomaly induced by positive (negative) SST anomaly over the eastern (western) equatorial Pacific. In El Nino years, two convective belts indicated by upper tropospheric velocity potential trough and mid-tropospheric rising motion, which are somewhat symmetric about the equator, extend toward the northeast and the southeast into the tropical North and South Atlantic respectively. Sandwiched between the ascent is a region of descending motion over Northeast Brazil. The southern branch of the anomalous Hadley cell is dynamically linked to the increase of rainfall over Uruguay-Southern Brazil. The regional response of anomalous circulation shows a stronger South American summer monsoon and an enhanced (weakened) subtropical high over the South Atlantic (South Pacific) Ocean. The decadal variation displays a meridional shift of the Intertropical Convergence Zone (ITCZ), which is tie to the anomalous cross-equatorial SST gradient over the Atlantic and the eastern Pacific. In conjunction with this mode is a large scale mass swing between the polar regions and midlatitudes in both hemispheres. Over the South Atlantic and the South Pacific

  13. The Impact of IT over Five Decades

    DEFF Research Database (Denmark)

    Bjørn-Andersen, Niels; Raymond, Benoit


    This contribution to the Ken D. Eason special issue is an illustration of the value of socio-technical analysis applied at an organizational level. We provide a brief historical overview of socio-technical IS research and review studies investigating the impact of IT on organizational structures...... in the last five decades, identifying a dominating (new) research theme in each decade. A key overall impact of IT in all decades has been a dramatic decrease in transaction costs making it increasingly easier for organizations to source from external providers. A five level taxonomy of sourcing arrangement...... leading to a new type of organization that we call the Ambient organization....

  14. Evolutionary significance of epigenetic variation

    NARCIS (Netherlands)

    Richards, C.L.; Verhoeven, K.J.F.; Bossdorf, O.; Wendel, J.F.; Greilhuber, J.; Dolezel, J.; Leitch, I.J.


    Several chapters in this volume demonstrate how epigenetic work at the molecular level over the last few decades has revolutionized our understanding of genome function and developmental biology. However, epigenetic processes not only further our understanding of variation and regulation at the

  15. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.


    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  16. Hydrogen atoms in a strong magnetic field

    International Nuclear Information System (INIS)

    Santos, R.R. dos.


    The energies and wave functions of the 14 lowest states of a Hydrogen atom in a strong magnetic field are calculated, using a variational scheme. The equivalence between the atomic problem and the problems related with excitons and impurities in semiconductors in the presence of a strong magnetic field are shown. The calculations of the energies and wave functions have been divided in two regions: the first, for the magnetic field ranging between zero and 10 9 G; in the second the magnetic field ranges between 10 9 and 10 11 G. The results have been compared with those obtained by previous authors. The computation time necessary for the calculations is small. Therefore this is a convenient scheme to obtain the energies and wave functions for the problem. Transition probabilities, wavelengths and oscillator strengths for some allowed transitions are also calculated. (Author) [pt

  17. Strong families and declining fertility

    NARCIS (Netherlands)

    Hilevych, Yuliya


    This dissertation focuses on the role of family and social relationships in individuals’ reproductive careers during the fertility decline in Soviet Ukraine from around 1950 to 1975. These three decades after the Second World War signified the end of the First Demographic Transition in Ukraine

  18. Strong families and declining fertility

    NARCIS (Netherlands)

    Hilevych, Yuliya


    This dissertation focuses on the role of family and social relationships in individuals’ reproductive careers during the fertility decline in Soviet Ukraine from around 1950 to 1975. These three decades after the Second World War signified the end of the First Demographic Transition in Ukraine

  19. Strong WW Interaction at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, Jose R


    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  20. Strong-back safety latch

    International Nuclear Information System (INIS)

    DeSantis, G.N.


    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

  1. Strong-back safety latch

    Energy Technology Data Exchange (ETDEWEB)

    DeSantis, G.N.


    The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch.

  2. Geographic variation in gorilla limb bones. (United States)

    Jabbour, Rebecca S; Pearman, Tessa L


    Gorilla systematics has received increased attention over recent decades from primatologists, conservationists, and paleontologists. Studies of geographic variation in DNA, skulls, and teeth have led to new taxonomic proposals, such as recognition of two gorilla species, Gorilla gorilla (western gorilla) and Gorilla beringei (eastern gorilla). Postcranial differences between mountain gorillas (G. beringei beringei) and western lowland gorillas (G. g. gorilla) have a long history of study, but differences between the limb bones of the eastern and western species have not yet been examined with an emphasis on geographic variation within each species. In addition, proposals for recognition of the Cross River gorilla as Gorilla gorilla diehli and gorillas from Tshiaberimu and Kahuzi as G. b. rex-pymaeorum have not been evaluated in the context of geographic variation in the forelimb and hindlimb skeletons. Forty-three linear measurements were collected from limb bones of 266 adult gorillas representing populations of G. b. beringei, Gorilla beringei graueri, G. g. gorilla, and G. g. diehli in order to investigate geographic diversity. Skeletal elements included the humerus, radius, third metacarpal, third proximal hand phalanx, femur, tibia, calcaneus, first metatarsal, third metatarsal, and third proximal foot phalanx. Comparisons of means and principal components analyses clearly differentiate eastern and western gorillas, indicating that eastern gorillas have absolutely and relatively smaller hands and feet, among other differences. Gorilla subspecies and populations cluster consistently by species, although G. g. diehli may be similar to the eastern gorillas in having small hands and feet. The subspecies of G. beringei are distinguished less strongly and by different variables than the two gorilla species. Populations of G. b. graueri are variable, and Kahuzi and Tshiaberimu specimens do not cluster together. Results support the possible influence of

  3. Atmospheric River Characteristics under Decadal Climate Variability (United States)

    Done, J.; Ge, M.


    How does decadal climate variability change the nature and predictability of atmospheric river events? Decadal swings in atmospheric river frequency, or shifts in the proportion of precipitation falling as rain, could challenge current water resource and flood risk management practice. Physical multi-scale processes operating between Pacific sea surface temperatures (SSTs) and atmospheric rivers over the Western U.S. are explored using the global Model for Prediction Across Scales (MPAS). A 45km global mesh is refined over the Western U.S. to 12km to capture the major terrain effects on precipitation. The performance of the MPAS is first evaluated for a case study atmospheric river event over California. Atmospheric river characteristics are then compared in a pair of idealized simulations, each driven by Pacific SST patterns characteristic of opposite phases of the Interdecadal Pacific Oscillation (IPO). Given recent evidence that we have entered a positive phase of the IPO, implications for current reservoir management practice over the next decade will be discussed. This work contributes to the NSF-funded project UDECIDE (Understanding Decision-Climate Interactions on Decadal Scales). UDECIDE brings together practitioners, engineers, statisticians, and climate scientists to understand the role of decadal climate information for water management and decisions.

  4. Decadal surface water quality trends under variable climate, land use, and hydrogeochemical setting in Iowa, USA (United States)

    Green, Christopher T.; Bekins, Barbara A.; Kalkhoff, Stephen J.; Hirsch, Robert M.; Liao, Lixia; Barnes, Kimberlee K.


    Understanding how nitrogen fluxes respond to changes in agriculture and climate is important for improving water quality. In the midwestern United States, expansion of corn cropping for ethanol production led to increasing N application rates in the 2000s during a period of extreme variability of annual precipitation. To examine the effects of these changes, surface water quality was analyzed in 10 major Iowa Rivers. Several decades of concentration and flow data were analyzed with a statistical method that provides internally consistent estimates of the concentration history and reveals flow-normalized trends that are independent of year-to-year streamflow variations. Flow-normalized concentrations of nitrate+nitrite-N decreased from 2000 to 2012 in all basins. To evaluate effects of annual discharge and N loading on these trends, multiple conceptual models were developed and calibrated to flow-weighted annual concentrations. The recent declining concentration trends can be attributed to both very high and very low discharge in the 2000s and to the long (e.g., 8 year) subsurface residence times in some basins. Dilution of N and depletion of stored N occurs in years with high discharge. Reduced N transport and increased N storage occurs in low-discharge years. Central Iowa basins showed the greatest reduction in flow-normalized concentrations, likely because of smaller storage volumes and shorter residence times. Effects of land-use changes on the water quality of major Iowa Rivers may not be noticeable for years or decades in peripheral basins of Iowa, and may be obscured in the central basins where extreme flows strongly affect annual concentration trends.

  5. Holocene Multi-Decadal to Millennial-Scale Hydrologic Variability on the South American Altiplano (United States)

    Fritz, S. C.; Baker, P. A.; Ekdahl, E.; Burns, S.


    On orbital timescales, lacustrine sediment records in the tropical central Andes show massive changes in lake level due to mechanisms related to global-scale drivers, varying at precessional timescales. Here we use stable isotopic and diatom records from two lakes in the Lake Titicaca drainage basin to reconstruct multi- decadal to millennial scale precipitation variability during the last 7000 to 8000 years. The records are tightly coupled at multi-decadal to millennial scales with each other and with lake-level fluctuations in Lake Titicaca, indicating that the lakes are recording a regional climate signal. A quantitative reconstruction of precipitation from stable isotopic data indicates that the central Andes underwent significant wet to dry alternations at multi- centennial frequencies with an amplitude of 30 to 40% of total precipitation. A strong millennial-scale component, similar in duration to periods of increased ice rafted debris flux in the North Atlantic, is observed in both lake records, suggesting that tropical North Atlantic sea-surface temperature (SST) variability may partly control regional precipitation. No clear relationship is evident between these records and the inferred ENSO history from Lago Pallcacocha in the northern tropical Andes. In the instrumental period, regional precipitation variability on inter-annual timescales is clearly influenced by Pacific modes; for example, most El Ninos produce dry and warm conditions in this part of the central Andes. However, on longer timescales, the control of tropical Pacific modes is less clear. Our reconstructions suggest that the cold intervals of the Holocene Bond events are periods of increased precipitation in the central Andes, thus indicating an anti-phasing of precipitation variation in the southern tropics of South America relative to the Northern Hemisphere monsoon region.

  6. Titanium: light, strong, and white (United States)

    Woodruff, Laurel; Bedinger, George


    Titanium (Ti) is a strong silver-gray metal that is highly resistant to corrosion and is chemically inert. It is as strong as steel but 45 percent lighter, and it is twice as strong as aluminum but only 60 percent heavier. Titanium dioxide (TiO2) has a very high refractive index, which means that it has high light-scattering ability. As a result, TiO2 imparts whiteness, opacity, and brightness to many products. ...Because of the unique physical properties of titanium metal and the whiteness provided by TiO2, titanium is now used widely in modern industrial societies.

  7. Contribution of solar radiation to decadal temperature variability over land. (United States)

    Wang, Kaicun; Dickinson, Robert E


    Global air temperature has become the primary metric for judging global climate change. The variability of global temperature on a decadal timescale is still poorly understood. This paper examines further one suggested hypothesis, that variations in solar radiation reaching the surface (Rs) have caused much of the observed decadal temperature variability. Because Rs only heats air during the day, its variability is plausibly related to the variability of diurnal temperature range (daily maximum temperature minus its minimum). We show that the variability of diurnal temperature range is consistent with the variability of Rs at timescales from monthly to decadal. This paper uses long comprehensive datasets for diurnal temperature range to establish what has been the contribution of Rs to decadal temperature variability. It shows that Rs over land globally peaked in the 1930s, substantially decreased from the 1940s to the 1970s, and changed little after that. Reduction of Rs caused a reduction of more than 0.2 °C in mean temperature during May to October from the 1940s through the 1970s, and a reduction of nearly 0.2 °C in mean air temperature during November to April from the 1960s through the 1970s. This cooling accounts in part for the near-constant temperature from the 1930s into the 1970s. Since then, neither the rapid increase in temperature from the 1970s through the 1990s nor the slowdown of warming in the early twenty-first century appear to be significantly related to changes of Rs.

  8. Evaluating decadal predictions of northern hemispheric cyclone frequencies

    Directory of Open Access Journals (Sweden)

    Tim Kruschke


    Full Text Available Mid-latitudinal cyclones are a key factor for understanding regional anomalies in primary meteorological parameters such as temperature or precipitation. Extreme cyclones can produce notable impacts on human society and economy, for example, by causing enormous economic losses through wind damage. Based on 41 annually initialised (1961–2001 hindcast ensembles, this study evaluates the ability of a single-model decadal forecast system (MPI-ESM-LR to provide skilful probabilistic three-category forecasts (enhanced, normal or decreased of winter (ONDJFM extra-tropical cyclone frequency over the Northern Hemisphere with lead times from 1 yr up to a decade. It is shown that these predictions exhibit some significant skill, mainly for lead times of 2–5 yr, especially over the North Atlantic and Pacific. Skill for intense cyclones is generally higher than for all detected systems. A comparison of decadal hindcasts from two different initialisation techniques indicates that initialising from reanalysis fields yields slightly better results for the first forecast winter (month 10–15, while initialisation based on an assimilation experiment provides better skill for lead times between 2 and 5 yr. The reasons and mechanisms behind this predictive skill are subject to future work. Preliminary analyses suggest a strong relationship of the model's skill over the North Atlantic with the ability to predict upper ocean temperatures modulating lower troposphere baroclinicity for the respective area and time scales.

  9. Variations in Developmental Patterns across Pragmatic Features (United States)

    Li, Qiong


    Drawing on the findings of longitudinal studies in uninstructed contexts over the last two decades, this synthesis explores variations in developmental patterns across second language (L2) pragmatic features. Two synthesis questions were addressed: (a) What are the variations in developmental patterns across pragmatic features?, and (b) What are…

  10. Decadal variability on the Northwest European continental shelf (United States)

    Jones, Sam; Cottier, Finlo; Inall, Mark; Griffiths, Colin


    Decadal scale time series of the shelf seas are important for understanding both climate and process studies. Despite numerous investigations of long-term temperature variability in the shelf seas, studies of salinity variability are few. Salt is a more conservative tracer than temperature in shallow seas, and it can reveal changes in local hydrographic conditions as well as transmitted basin-scale changes. Here, new inter-annual salinity time series on the northwest European shelf are developed and a 13 year high resolution salinity record from a coastal mooring in western Scotland is presented and analysed. We find strong temporal variability in coastal salinity on timescales ranging from tidal to inter-annual, with the magnitude of variability greatest during winter months. There is little seasonality and no significant decadal trend in the coastal time series of salinity. We propose 4 hydrographic states to explain salinity variance in the shelf area west of Scotland based on the interaction between a baroclinic coastal current and wind-forced barotropic flow: while wind forcing is important, we find that changes in the buoyancy-driven flow are more likely to influence long-term salinity observations. We calculate that during prevailing westerly wind conditions, surface waters in the Sea of the Hebrides receive a mix of 62% Atlantic origin water to 38% coastal sources. This contrasts with easterly wind conditions, during which the mix is 6% Atlantic to 94% coastal sources on average. This 'switching' between hydrographic states is expected to impact nutrient transport and therefore modify the level of primary productivity on the shelf. This strong local variability in salinity is roughly an order of magnitude greater than changes in the adjacent ocean basin, and we infer from this that Scottish coastal waters are likely to be resilient to decadal changes in ocean climate.

  11. Decadal changes of surface elevation over permafrost area estimated using reflected GPS signals (United States)

    Liu, Lin; Larson, Kristine M.


    Conventional benchmark-based survey and Global Positioning System (GPS) have been used to measure surface elevation changes over permafrost areas, usually once or a few times a year. Here we use reflected GPS signals to measure temporal changes of ground surface elevation due to dynamics of the active layer and near-surface permafrost. Applying the GPS interferometric reflectometry technique to the multipath signal-to-noise ratio data collected by a continuously operating GPS receiver mounted deep in permafrost in Barrow, Alaska, we can retrieve the vertical distance between the antenna and reflecting surface. Using this unique kind of observables, we obtain daily changes of surface elevation during July and August from 2004 to 2015. Our results show distinct temporal variations at three timescales: regular thaw settlement within each summer, strong interannual variability that is characterized by a sub-decadal subsidence trend followed by a brief uplift trend, and a secular subsidence trend of 0.26 ± 0.02 cm year-1 during 2004 and 2015. This method provides a new way to fully utilize data from continuously operating GPS sites in cold regions for studying dynamics of the frozen ground consistently and sustainably over a long time.

  12. Decadal changes in wind patterns impact on high PM10 concentration in the Korean Peninsula (United States)

    Lee, T.; Jeon, W.; Lee, H.; Lee, S.


    Principal component analysis is a statistical method that can be used not only to analyze the principal components of data, but also to reduce dimensionality and remove noise of data. And K-means cluster analysis is one of the commonly used non-hierarchical cluster analysis methods, which classifies clusters based on distance between data. In order to classify the wind patterns impact on high PM10 concentration in the Korean Peninsula, K-means cluster analysis was performed with reproducing the data using principal component analysis. We analyzed the decadal changes in the wind patterns around the Korean Peninsula and their impact on PM10 concentration. For the analysis, we obtained 900 hPa wind fields from the FNL analysis data and classified the specific patterns causing the PM10 episodes in the Korean Peninsula during the recent 10 years (2007-2016). We then investigated how the varying wind patterns affected the changes in the PM10 concentrations from past to present. The cluster analysis results indicated that the high PM10 episodes in the Korean Peninsula was strongly affected by winds from southwest and northwest, causing the PM10 transport from China to the Korean Peninsula. We also found that the wind patterns causing the high PM10 shows clear annual variation during the recent 10 years.

  13. Brain volumetric changes and cognitive ageing during the eighth decade of life (United States)

    Dickie, David Alexander; Cox, Simon R.; Valdes Hernandez, Maria del C.; Corley, Janie; Royle, Natalie A.; Pattie, Alison; Aribisala, Benjamin S.; Redmond, Paul; Muñoz Maniega, Susana; Taylor, Adele M.; Sibbett, Ruth; Gow, Alan J.; Starr, John M.; Bastin, Mark E.; Wardlaw, Joanna M.; Deary, Ian J.


    Abstract Later‐life changes in brain tissue volumes—decreases in the volume of healthy grey and white matter and increases in the volume of white matter hyperintensities (WMH)—are strong candidates to explain some of the variation in ageing‐related cognitive decline. We assessed fluid intelligence, memory, processing speed, and brain volumes (from structural MRI) at mean age 73 years, and at mean age 76 in a narrow‐age sample of older individuals (n = 657 with brain volumetric data at the initial wave, n = 465 at follow‐up). We used latent variable modeling to extract error‐free cognitive levels and slopes. Initial levels of cognitive ability were predictive of subsequent brain tissue volume changes. Initial brain volumes were not predictive of subsequent cognitive changes. Brain volume changes, especially increases in WMH, were associated with declines in each of the cognitive abilities. All statistically significant results were modest in size (absolute r‐values ranged from 0.114 to 0.334). These results build a comprehensive picture of macrostructural brain volume changes and declines in important cognitive faculties during the eighth decade of life. Hum Brain Mapp 36:4910–4925, 2015. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc PMID:26769551

  14. Decadal variability of surface solar radiation over China (United States)

    Wang, K.


    Observations show that national average surface solar radiation (Rs) decreased by -8.0 W m-2 per decade from 1960 to 1990 and sharply increased from 1990 to 1993. However, none of the state-of-the-art climate models can reproduce such decrease/increase of Rs. This study shows that Rs observations over China have significant inhomogeneity. Before 1989, Rs was calculated as a sum of direct (Rsdir) and diffuse (Rsdif) solar radiation observations measured by pyrheliometers and shaded pyranometers separately. Due to technical limitations and irregular calibration, pyranometers before 1990 had a strong sensitivity drift problem, which introduced crucial spurious decreasing trends into Rsdif and Rs data. From 1990 to 1993, instruments and measurement methods were replaced and measuring stations were restructured in China, which resulted in an abrupt increase in the observed Rs. Rs calculated from Sunshine duration (SunDu) provide a reliable reference in assessing decadal variability of Rs. SunDu derived Rs have no sensitivity drift problem because of its daily changed recording material. SunDu-derived Rs averaged over China decreased by -2.9 W m-2 per decade from 1961 to 1990, and had a negligible trend afterward. During the period of 1994-2012 when Rs observations were free of inhomogeneity mentioned above, the observed and SunDu-derived Rs consistently show a negligible trend, being less than 0.1 W m-2 per decade. These trends can be reproduced by high-quality CMIP5 Earth System Models (ESM). This level of agreement is due to the incorporation of a near real emission inventory of atmospheric aerosols by CMIP5 ESMs. Rs from ERA-Interim has a good agreement with SunDu-derived Rs. However, ERA-interim does not allow aerosol loading to change annually. ERA-Interim Rs shows an unreliable increasing trend of 1.9 W m-2 per decade from 1990 to 2013 because it does not include the impact of recent increased atmospheric aerosols over China. GEWEX Rs calculated from ISCCP cloud

  15. Arctic climate change and decadal variability

    NARCIS (Netherlands)

    Linden, van der Eveline C.


    High northern latitudes exhibit enhanced near-surface warming in a climate with increasing greenhouse gases compared to other parts of the globe, indicating an amplified climate response to external forcing. Decadal to multidecadal variability sometimes enhances and at other times reduces the

  16. Arctic climate change and decadal variability

    NARCIS (Netherlands)

    Linden, van der Eveline C.


    High northern latitudes exhibit enhanced near-surface warming in a climate with increasing greenhouse gases compared to other parts of the globe, indicating an amplified climate response to external forcing. Decadal to multidecadal variability sometimes enhances and at other times reduces the

  17. A Decade of Change in NO

    NARCIS (Netherlands)

    McLinden, Chris A.; Fioletov, Vitali; Krotkov, Nickolay A.; Li, Can; Boersma, Folkert; Adams, Cristen


    A decade (2005-2014) of observations from the Ozone Monitoring Instrument (OMI) were used to examine trends in nitrogen dioxide (NO2) and sulfur dioxide (SO2) over a large region of western Canada and the northern United States, with a focus on the Canadian oil sands. In the

  18. Evolutionary robotics in two decades: A review

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana; Volume 40; Issue 4. Evolutionary robotics in two decades: A review. Sameer Gupta Ekta Singla. Mechanical Sciences Volume 40 Issue 4 June 2015 pp ... Author Affiliations. Sameer Gupta1 Ekta Singla1. School of Mechanical, Materials and Energy Engineering, IIT Ropar, Rupnagar 140001, India ...

  19. A Challenging Decade For Employment Counselors (United States)

    Fantaci, Anthony


    The employment counselor outlook for this decade is good if the needs of youth, older workers, women, and the handicapped are provided for. Short-term curtailment and redirection of counseling staff in state agencies will result from the phasing down of categorical programs and from funding restraints. In the long run, though, there will be a…

  20. Reflections on a Decade of Microfoundations Research

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul


    I briefly take stock on the microfoundations project which has become influential in macro-management research over the past decade or so. While the project has now moved into distinct theorybuilding, it still need to engage in serious empirical research. I discuss a number of challenges and solu...

  1. A Decade of Mobile Computing for Students (United States)

    Jenny, Frederick J.


    This paper describes the mobile computing at Grove City College, a small, private, liberal arts institution in Western Pennsylvania. They have entered their second decade of mobile computing for students in the school of about 2200. Each incoming freshman receives a laptop computing and inkjet printer during the fall orientation, all a benefit of…

  2. The Athens Acropolis Strong Motion Array (United States)

    Kalogeras, I. S.; Evangelidis, C. P.; Melis, N. S.; Boukouras, K.


    During the last decades, extensive restoration works through a dedicated "Acropolis Restoration Service" (YSMA) take place in the Acropolis, the greatest sanctuary of ancient Athens. Since 2008, a permanent strong motion array was deployed by the Institute of Geodynamics, National Observatory of Athens (NOA-IG) in collaboration with YSMA. Free field installations were decided at sites showing various characteristics, aiming to investigate differences in geotechnical properties as well as the structure response of Parthenon itself. The installation phase is presented, with the techniques used to overcome difficulties (i.e. extreme weather conditions, power and communication limitations, restoration works and visitors) and the special care taken for the specific archaeological site. Furthermore, indicative examples of seismic events recorded by the array are analyzed and the complexity of the hill and the monument is made apparent. Among them, the long distance events of Tohoku, Japan 2010 and Van, Turkey 2011, some regional moderate earthquakes in Greece and some weak earthquakes from the vicinity. Continuous ambient noise monitoring using PQLX software gives some first indicative results, showing a variety of characteristics at installation sites. Finally, further developments and future steps are presented such as: the extension of the array, the integration of seismic data within the GIS platform of YSMA at the site and the use of strong motion records, in conjunction with data from other monitoring systems operating in Acropolis for the study of specific monuments.

  3. Variational principles

    CERN Document Server

    Moiseiwitsch, B L


    This graduate-level text's primary objective is to demonstrate the expression of the equations of the various branches of mathematical physics in the succinct and elegant form of variational principles (and thereby illuminate their interrelationship). Its related intentions are to show how variational principles may be employed to determine the discrete eigenvalues for stationary state problems and to illustrate how to find the values of quantities (such as the phase shifts) that arise in the theory of scattering. Chapter-by-chapter treatment consists of analytical dynamics; optics, wave mecha

  4. Decadal prediction skill in a multi-model ensemble

    Energy Technology Data Exchange (ETDEWEB)

    Oldenborgh, Geert Jan van; Wouters, Bert; Hazeleger, Wilco [Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, De Bilt (Netherlands); Doblas-Reyes, Francisco J. [Institucio Catalana de Recerca i Estudis Avancats (ICREA) and Institut Catala de Ciencies del Clima (IC3), Barcelona (Spain)


    Decadal climate predictions may have skill due to predictable components in boundary conditions (mainly greenhouse gas concentrations but also tropospheric and stratospheric aerosol distributions) and initial conditions (mainly the ocean state). We investigate the skill of temperature and precipitation hindcasts from a multi-model ensemble of four climate forecast systems based on coupled ocean-atmosphere models. Regional variations in skill with and without trend are compared with similarly analysed uninitialised experiments to separate the trend due to monotonically increasing forcings from fluctuations around the trend due to the ocean initial state and aerosol forcings. In temperature most of the skill in both multi-model ensembles comes from the externally forced trends. The rise of the global mean temperature is represented well in the initialised hindcasts, but variations around the trend show little skill beyond the first year due to the absence of volcanic aerosols in the hindcasts and the unpredictability of ENSO. The models have non-trivial skill in hindcasts of North Atlantic sea surface temperature beyond the trend. This skill is highest in the northern North Atlantic in initialised experiments and in the subtropical North Atlantic in uninitialised simulations. A similar result is found in the Pacific Ocean, although the signal is less clear. The uninitialised simulations have good skill beyond the trend in the western North Pacific. The initialised experiments show some skill in the decadal ENSO region in the eastern Pacific, in agreement with previous studies. However, the results in this study are not statistically significant (p {approx} 0.1) by themselves. The initialised models also show some skill in forecasting 4-year mean Sahel rainfall at lead times of 1 and 5 years, in agreement with the observed teleconnection from the Atlantic Ocean. Again, the skill is not statistically significant (p {approx} 0.2). Furthermore, uninitialised simulations

  5. The SNAP Strong Lens Survey

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, P.


    Basic considerations of lens detection and identification indicate that a wide field survey of the types planned for weak lensing and Type Ia SNe with SNAP are close to optimal for the optical detection of strong lenses. Such a ''piggy-back'' survey might be expected even pessimistically to provide a catalogue of a few thousand new strong lenses, with the numbers dominated by systems of faint blue galaxies lensed by foreground ellipticals. After sketching out our strategy for detecting and measuring these galaxy lenses using the SNAP images, we discuss some of the scientific applications of such a large sample of gravitational lenses: in particular we comment on the partition of information between lens structure, the source population properties and cosmology. Understanding this partitioning is key to assessing strong lens cosmography's value as a cosmological probe.

  6. Strong coupling phase in QED

    International Nuclear Information System (INIS)

    Aoki, Ken-ichi


    Existence of a strong coupling phase in QED has been suggested in solutions of the Schwinger-Dyson equation and in Monte Carlo simulation of lattice QED. In this article we recapitulate the previous arguments, and formulate the problem in the modern framework of the renormalization theory, Wilsonian renormalization. This scheme of renormalization gives the best understanding of the basic structure of a field theory especially when it has a multi-phase structure. We resolve some misleading arguments in the previous literature. Then we set up a strategy to attack the strong phase, if any. We describe a trial; a coupled Schwinger-Dyson equation. Possible picture of the strong coupling phase QED is presented. (author)

  7. Strong Decomposition of Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jørgensen, Jørgen; Kagan, Abram M.; Pitt, Loren D.


    A random variable X is stongly decomposable if X=Y+Z where Y=Φ(X) and Z=X-Φ(X) are independent non-degenerated random variables (called the components). It is shown that at least one of the components is singular, and we derive a necessary and sufficient condition for strong decomposability...

  8. Strong interaction at finite temperature

    Indian Academy of Sciences (India)

    Abstract. We review two methods discussed in the literature to determine the effective parameters of strongly interacting particles as they move through a heat bath. The first one is the general method of chiral perturbation theory, which may be readily applied to this problem. The other is the method of thermal QCD sum rules ...

  9. Diurnal variations of Titan (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.


    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  10. Strong-strong beam-beam simulation on parallel computer

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Ji


    The beam-beam interaction puts a strong limit on the luminosity of the high energy storage ring colliders. At the interaction points, the electromagnetic fields generated by one beam focus or defocus the opposite beam. This can cause beam blowup and a reduction of luminosity. An accurate simulation of the beam-beam interaction is needed to help optimize the luminosity in high energy colliders.

  11. Strong-strong beam-beam simulation on parallel computer

    International Nuclear Information System (INIS)

    Qiang, Ji


    The beam-beam interaction puts a strong limit on the luminosity of the high energy storage ring colliders. At the interaction points, the electromagnetic fields generated by one beam focus or defocus the opposite beam. This can cause beam blowup and a reduction of luminosity. An accurate simulation of the beam-beam interaction is needed to help optimize the luminosity in high energy colliders

  12. Medical radiation protection in next decade

    International Nuclear Information System (INIS)

    Rehani, M. M.; Vano, E.


    Interest in medical radiation protection today is the same as what it would have been almost a century ago. After many decades of relatively safe application of radiation in medicine, the recent spurt in over exposures, over-use of imaging and accidental exposures has created the need for stakeholders to join hands and contribute towards increasing radiation safety levels. Whether it be the need for technological developments to achieve sub-mSv CT scans, tracking of patient exposure history, accounting for repeated exposures of the same patient, specific consideration of requests for radiological examinations that deliver few mSv of dose, or utilization of regulatory approaches, radiological equipment will need to alert users whenever the radiation dose to the patient is above a defined value. The current decade will focus increasingly on carcinogenic effects in patients. (authors)

  13. A decade of advances in metallic fuel

    International Nuclear Information System (INIS)

    Seidel, B.R.; Batte, G.L.; Dodds, N.E.; Hofman, G.L.; Lahm, C.E.; Pahl, R.G.; Porter, D.L.; Tsai, H.; Walters, L.C.


    Significant advances in the understanding of behavior and performance of metallic fuels to high burnup have been achieved over the past four decades. Metallic fuels were the first fuels for liquid-metal-cooled fast reactors (LMR) but in the late 1960s worldwide interest turned toward ceramic fuels before the full potential of metallic fuel could be achieved. Now metallic fuels are recognized as a preferred viable option with regard to safety, integral fuel cycle, waste minimization and deployment economics. This paper reviews the key advances in the last decade and highlights the behavior and performance features which have demonstrated a much greater potential than previously expected. 28 refs., 2 figs., 1 tab

  14. Does education improve cognitive performance four decades after school completion? (United States)

    Schneeweis, Nicole; Skirbekk, Vegard; Winter-Ebmer, Rudolf


    We study the effect of secondary education on cognitive performance toward the end of working age. We exploit the exogenous variation in years of schooling arising from compulsory schooling reforms implemented in six European countries during the 1950s and 1960s. Using data of individuals, approximately age 60, from the Survey of Health, Ageing and Retirement in Europe (SHARE), we assess the causal effect of education on memory, fluency, numeracy, and orientation-to-date. Furthermore, we study education effects on cognitive decline. We find a positive impact of schooling on memory scores. One year of education increases the memory score approximately four decades later by about 0.2, which amounts to 10 % of a standard deviation. Furthermore, we find some evidence for a protective effect of schooling on cognitive decline in terms of verbal fluency.

  15. Older Adults’ Attitudes Toward Cohabitation: Two Decades of Change (United States)

    Wright, Matthew R.


    Objectives: Our study tracks cohort change in the attitudes of adults aged 50 and older toward cohabitation from 1994 to 2012. Method: We used data from the 1994, 2002, and 2012 waves of the General Social Survey to examine the roles of cohort replacement and intracohort change in the trend toward favorable cohabitation attitudes and to examine sociodemographic variation in patterns of support for cohabitation. Results: Support for cohabitation accelerated over time with nearly half (46%) of older adults reporting favorable attitudes toward cohabitation in 2012 versus just 20% in 1994. This shift in older adults’ attitudes largely reflected cohort replacement rather than intracohort change. Some of the factors associated with later life cohabitation experience were linked to supportive attitudes. Discussion: Cohort succession is fueling the growing acceptance of cohabitation among older adults and coincides with the rapid growth in later life cohabitation that has occurred in recent decades. PMID:26307489

  16. Predictability of Pacific Decadal Climate Variability and Climate Impacts (Invited) (United States)

    Newman, M.


    Predictability of Pacific sea surface temperature (SST) climate variations and climate impacts on time scales of 1-10 years is discussed, using a global linear inverse model (LIM) as an empirical benchmark for decadal surface temperature forecast skill. Constructed from the observed simultaneous and 1-yr lag covariability statistics of annually averaged sea surface temperature (SST) and surface (2 m) land temperature global anomalies during 1901-2009, the LIM has hindcast skill for leads of 2-5 yr and 6-9 yr comparable to and sometimes even better than skill of the phase 5 of the Coupled Model Intercomparison Project (CMIP5) model hindcasts initialized annually over the period 1960-2000 and has skill far better than damped persistence (e.g., a local univariate AR1 process). Pronounced similarity in geographical variations of skill between LIM and CMIP5 hindcasts suggests similarity in their sources of skill as well, supporting additional evaluation of LIM predictability. For forecast leads above 1-2 yr, LIM skill almost entirely results from three nonorthogonal patterns: one corresponding to the secular trend and two more, each with about 10-yr decorrelation time scales but no trend, that represent most of the predictable portions of the Atlantic multidecadal oscillation (AMO) and Pacific decadal oscillation (PDO) indices, respectively. In contrast, for forecasts greater than about two years, ENSO acts as noise and degrades forecast skill. These results suggest that current coupled model decadal forecasts may not yet have much skill beyond that captured by multivariate, predictably linear dynamics. A particular focus will be on the predictability of the PDO, which represents the dominant mode of Pacific decadal SST variability. The PDO is shown to represent a few different physical processes, including wind-driven changes of SSTs that can occur either due to daily weather variability or to tropical forcing, and variations in the North Pacific western boundary

  17. Design of a decade scaler prototype

    International Nuclear Information System (INIS)

    Rill Isaris; Widodo Priyodiprojo.


    A prototype of a simple decade scaler made of devices and components available in the local market, is described. The constituents of the system, consisting of an amplifier, pulse shaper, counting system, low voltage and high voltage supply, are also described. The number of pulses counted are indicated on six digits, varying to a maximum of 999999 counts, using LED device. This apparatus may be interconnected with scintillation and Geiger Muller detectors. (author)

  18. Dynamic Evaluation of Two Decades of CMAQ Simulations over the Continental United States (book chapter) (United States)

    This paper focuses on dynamic evaluation of the CMAQ model over the continental United States using multi-decadal simulations for the period from 1990 to 2010 to examine how well the changes in observed ozone air quality induced by variations in meteorology and/or emissions are s...

  19. Inter-Decadal Nature of Rainfall Character Over Sudano-Sahel ...

    African Journals Online (AJOL)

    The study investigated the spatial pattern of decadal variations in annual rainfall amounts in the Sokoto-Rima River Basin, Northwestern Nigeria. Rainfall dataset which is available on high-resolution (0.5 x 0.5 degree) grids resolution from the Climatic Research Unit CRU TS 3.21 of the University of East Anglia, Norwich, ...

  20. Can intraseasonal to decadal forecasts benefit from from consideration of lunar forcing?

    CSIR Research Space (South Africa)

    Malherbe, J


    Full Text Available A possible forcing mechanism for intra-seasonal rainfall distribution to bi-decadal climate variability is explored. The atmospheric response to external forcing is demonstrated at a daily and annual time scale by noting variation in the Southern...

  1. Climatology and decadal variability of the Ross Sea shelf waters

    Directory of Open Access Journals (Sweden)

    A. Russo


    Full Text Available The World Ocean Database 2001 data located in the Ross Sea (named WOD01 and containing data in this region since 1928 are merged with recent data collected by the Italian expeditions (CLIMA dataset in the period November 1994-February 2004 in the same area. From this extended dataset, austral summer climatologies of the main Ross Sea subsurface, intermediate and bottom water masses: High Salinity Shelf Water (HSSW, Low Salinity Shelf Water (LSSW, Ice Shelf Water (ISW and Modified Circumpolar Deep Water (MCDW have been drawn. The comparison between the WOD01_1994 climatologies (a subset of the WOD01 dataset until April 1994 and the CLIMA ones for the period 1994/95-2003/04 showed significant changes occurred during the decade. The freshening of the Ross Sea shelf waters which occurred during the period 1960-2000, was confirmed by our analysis in all the main water masses, even though with a spatially varying intensity. Relevant variations were found for the MCDW masses, which appeared to reduce their presence and to deepen; this can be ascribed to the very limited freshening of the MCDW core, which allowed an increased density with respect to the surrounding waters. Variations in the MCDW properties and extension could have relevant consequences, e.g. a decreased Ross Ice Shelf basal melting or a reduced supply of nutrients, and may also be indicative of a reduced thermohaline circulation within the Ross Sea. Shelf Waters (SW having neutral density γn > 28.7 Kg m-3, which contribute to form the densest Antarctic Bottom Waters (AABW, showed a large volumetric decrease in the 1994/95-2003/04 decade, most likely as a consequence of the SW freshening.

  2. Strong Performers and Successful Reformers in Education: Lessons from PISA for Japan (United States)

    OECD Publishing (NJ1), 2012


    For decades Japan has remained at or near the top of international assessments of student learning; and in the past decade, students in Japan have become more engaged in learning. However, the government aspires to improve learning outcomes even further. "Strong Performers and Successful Reformers in Education: Lessons from PISA for…

  3. Role of the North Atlantic Oscillation in decadal temperature trends (United States)

    Iles, Carley; Hegerl, Gabriele


    Global temperatures have undergone periods of enhanced warming and pauses over the last century, with greater variations at local scales due to internal variability of the climate system. Here we investigate the role of the North Atlantic Oscillation (NAO) in decadal temperature trends in the Northern Hemisphere for periods with large decadal NAO trends. Using a regression based technique we find a best estimate that trends in the NAO more than halved (reduced by 57%, 5%–95%: 47%–63%) the winter warming over the Northern Hemisphere extratropics (NH; 30N–90N) from 1920–1971 and account for 45% (±14%) of the warming there from 1963–1995, with larger impacts on regional scales. Over the period leading into the so-called warming hiatus, 1989–2013, the NAO reduced NH winter warming to around one quarter (24%; 19%–31%) of what it would have been, and caused large negative regional trends, for example, in Northern Eurasia. Warming is more spatially uniform across the Northern Hemisphere after removing the NAO influence in winter, and agreement with multi-model mean simulated trends improves. The impact of the summer NAO is much weaker, but still discernible over Europe, North America and Greenland, with the downward trend in the summer NAO from 1988–2012 reducing warming by about a third in Northern Europe and a half in North America. A composite analysis using CMIP5 control runs suggests that the ocean response to prolonged NAO trends may increase the influence of decadal NAO trends compared to estimates based on interannual regressions, particularly in the Arctic. Results imply that the long-term NAO trends over the 20th century alternately masked or enhanced anthropogenic warming, and will continue to temporarily offset or enhance its effects in the future.

  4. PREFACE: Strongly correlated electron systems Strongly correlated electron systems (United States)

    Saxena, Siddharth S.; Littlewood, P. B.


    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  5. Separating decadal global water cycle variability from sea level rise. (United States)

    Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R


    Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

  6. The decade for women...1985 and beyond. (United States)


    This special issue of "The Tribune" attempts to answer the many requests for information on the Decade for Women: Equality, Development and Peace. There has been a particular need for specific information on plans and preparations for the 1985 World Conference. Information is gathered in this issue on background to the Decade, the views of various governmental and nongovernmental groups concerning the issues and priorities of the Conference, the preparations underway, some of the major initiatives taken in the Decade, and some useful addresses for soliciting further information. The Program of Action for the 2nd half of the UN Decade for Women: Equality, Development and Peace focuses on ensuring women's increased participation in the realization of the objectives of the World Plan of Action. In particular, the World Plan of Action gives high priority to improving the conditions of the most disadvantaged groups of women, especially the rural and urban poor and the vast group of women workers in the tertiary sector. The Program of Action reiterates these priorities, particularly those disadvantaged because of socioeconomic and historic conditions, with emphasis on the rural and urban poor and on the subthemes: employment; education; and health. The Economic and Social Council (ECOSOC) invited nongovermental organizations (NGOs); intergovernmental organizations; UN specialized agencies, organs, and organizations; regional commissions; and member states to submit their views on their contributions to the World Conference and the possible themes and issues of the Conference, in writing, to the Center for Social Development and Humanitarian Affairs, for consolidated presentation to the preparatory body. Summaries of the views expressed by these groups are provided. Overall, there was an emphasis given by the Member States to the importance of involving women and women's organizations in the preparations for the Conference. In many replies it was indicated that the review

  7. Strongly correlated systems experimental techniques

    CERN Document Server

    Mancini, Ferdinando


    The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...

  8. Strongly Correlated Systems Theoretical Methods

    CERN Document Server

    Avella, Adolfo


    The volume presents, for the very first time, an exhaustive collection of those modern theoretical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciates consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as po...

  9. Strongly correlated systems numerical methods

    CERN Document Server

    Mancini, Ferdinando


    This volume presents, for the very first time, an exhaustive collection of those modern numerical methods specifically tailored for the analysis of Strongly Correlated Systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and material science, belong to this class of systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognized main contributors. The exposition has a clear pedagogical cut and fully reports on the most relevant case study where the specific technique showed to be very successful in describing and enlightening the puzzling physics of a particular strongly correlated system. The book is intended for advanced graduate students and post-docs in the field as textbook and/or main reference, but also for other researchers in the field who appreciate consulting a single, but comprehensive, source or wishes to get acquainted, in a as painless as possi...

  10. Strongly nonlinear oscillators analytical solutions

    CERN Document Server

    Cveticanin, Livija


    This book provides the presentation of the motion of pure nonlinear oscillatory systems and various solution procedures which give the approximate solutions of the strong nonlinear oscillator equations. The book presents the original author’s method for the analytical solution procedure of the pure nonlinear oscillator system. After an introduction, the physical explanation of the pure nonlinearity and of the pure nonlinear oscillator is given. The analytical solution for free and forced vibrations of the one-degree-of-freedom strong nonlinear system with constant and time variable parameter is considered. Special attention is given to the one and two mass oscillatory systems with two-degrees-of-freedom. The criteria for the deterministic chaos in ideal and non-ideal pure nonlinear oscillators are derived analytically. The method for suppressing chaos is developed. Important problems are discussed in didactic exercises. The book is self-consistent and suitable as a textbook for students and also for profess...

  11. UNAVCO: A Decade Supporting EarthScope - Three Decades of Supporting Geodesy for Science Innovation (United States)

    Miller, M.


    UNAVCO supports research that establishes Earth's reference frame, enabling mapping of the planet's shape and mass; determines changes in the distribution of ice, water resources, and sea level; characterizes processes that contribute to natural and man-made hazards; and recognizes land-use changes (including subsidence, soil moisture, and health of wetlands). UNAVCO began as an investigator cooperative in 1984 - with the goal of sharing equipment and technologies that were expensive, rapidly changing, and extraordinarily powerful. Today as NSF's National Earth Science Geodetic Facility, on the eve of our 30th anniversary, we are excited to highlight a decade of support for major components of EarthScope, especially the Plate Boundary Observatory (PBO). Innovations by UNAVCO and the UNAVCO community have supported steady advancement towards millimeter-level global geodesy. Modern space geodesy provides new observational capability for contemporary deformation and magmatism in active convergent margin systems that operate over a spectrum of temporal and spatial scales, especially the PBO. Time scales vary from seconds to millennia, and spatial scales from borehole nanostrains to the global plate circuit. High-precision strain or 3-D point observations with borehole strainmeter or Global Positioning System (GPS) observations and geodetic imaging with SAR and LiDAR are used in combination to reveal these complex systems. GPS now combines with strong ground motion accelerometer time series to provide important enhancements to conventional seismology. The resulting 3-D fully georeferenced dynamic positioning time series are free of ambiguities associated with seismometer tilt and displacement. Geodesy constrains plate kinematics for convergence rate and direction, co-seismic deformation during great and moderate earthquakes, episodic tremor and slip events and related transient deformation, tectono-magmatic interactions, and the possible triggering effects of

  12. Flavour Democracy in Strong Unification

    CERN Document Server

    Abel, S A; Abel, Steven; King, Steven


    We show that the fermion mass spectrum may naturally be understood in terms of flavour democratic fixed points in supersymmetric theories which have a large domain of attraction in the presence of "strong unification". Our approach provides an alternative to the approximate Yukawa texture zeroes of the Froggatt-Nielsen mechanism. We discuss a particular model based on a broken gauged $SU(3)_L\\times SU(3)_R$ family symmetry which illustrates our approach.

  13. 14-Decades Calibration in Airborne Detectors for Environmental Science (14DeCADES), Phase II (United States)

    National Aeronautics and Space Administration — The 14-DeCADES SBIR leverages the results of a FY13 spontaneous IRAD and a subsequent successful Phase 1 SBIR which characterized and tested key elements that will...

  14. What can decadal variability tell us about climate feedbacks and sensitivity? (United States)

    Colman, Robert; Power, Scott B.


    Radiative feedbacks are known to determine climate sensitivity. Global top-of-atmosphere radiation correlations with surface temperature performed here show that decadal variability in surface temperature is also reinforced by strong positive feedbacks in models, both in the long wave (LW) and short wave (SW), offsetting much of the Planck radiative damping. Net top-of-atmosphere feedback is correlated with the magnitude of decadal temperature variability, particularly in the tropics. This indicates decadal-timescale radiative reinforcement of surface temperature variability. Assuming a simple global ocean mixed layer response, the reinforcement is found to be of a magnitude comparable to that required for typical decadal global scale anomalies. The magnitude of decadal variability in the tropics is uncorrelated with LW feedbacks, but it is correlated with total SW feedbacks, which are, in turn, correlated with tropical SW cloud feedback. Globally, water vapour/lapse rate, surface albedo and cloud feedbacks on decadal timescales are, on average, as strong as those operating under climate change. Together these results suggest that some of the physical processes responsible for setting the magnitude of global temperature change in the twenty-first century and climate sensitivity also help set the magnitude of the natural decadal variability. Furthermore, a statistically significant correlation exists between climate sensitivity and decadal variability in the tropics across CMIP5 models, although this is not apparent in the earlier generation of CMIP3 models. Thus although the link to sensitivity is not conclusive, this opens up potential paths to improve our understanding of climate feedbacks, climate sensitivity and decadal climate variability, and has the potential to reduce the associated uncertainty.

  15. Synthesis and characterization of CuO nanoparticles using strong ...

    Indian Academy of Sciences (India)

    In the present study, cupric oxide (CuO) nanoparticles were synthesized by electrochemical discharge process using strong base electrolytes. The experiments were carried out separately using NaOH and KOH electrolytes.The mass output rate and the crystal size were obtained with variation of the rotation speed of ...

  16. The DECADES project - Outline and general overview

    International Nuclear Information System (INIS)


    The environmental and health-related impacts of different energy systems, including those associated with the production of electricity, are emerging as significant issues for the coming decades. This interest is highlighted by the current debate about health effects of pollution, environmental damages due to acidification of forests and lakes, concerns about the safety of nuclear power plants and radioactive waste management, and the potential risks of global climate change induced by increasing atmospheric concentrations of carbon dioxide and other greenhouse gases. All fuel chains within the electricity generation system involve some health risks and lead to some environmental impacts. This fact, together with the emerging needs of many countries to define their energy programmes for the coming decades, has provided the basis for a growing interest in the application of improved data, tools and techniques for comparative assessment of different electricity generating systems, particularly from an environmental and human health viewpoint. The need to design and implement sustainable strategies in the electricity sector has been stressed in many international fora such as the Senior Expert Symposium on Electricity and the Environment (Helsinki, 1991), the United Nations Conference on Environment and Development (Rio de Janeiro, 1992) and the 15th Conference of the World Energy Council (Madrid, 1992). The essential goal of sustainable strategies is to provide the energy services required for supporting economic growth and improving quality of life, especially in developing countries, while minimising the health and environmental impacts of human activities. The inter-agency joint project on data bases and methodologies for comparative assessment of different energy sources for electricity generation [DECADES] has been established with the objective of enhancing capabilities for incorporating health and environmental issues in the comparative assessment of different

  17. Two Decades After: ``After The Wake: Postpositivistic Educational Thought'' (United States)

    Phillips, D. C.

    This essay is an updating of one that was published exactly two decades ago; in the intervening years there has been a revival of interest in positivism as a historical phenomenon in epistemology and philosophy of science (some references to which are given), but there also has been heightened awareness of the various weaknesses of the positivist position. But the main themes of the original essay are still valid - the tendency persists (and may even have grown stronger) for individuals to charge their opponents indiscriminately with being ``positivists'' without being clear what actually characterizes this position; and there is still a failure to recognize that positivism was a complex ``position'' some of whose theses can be held by individuals who strongly oppose other theses and thus often do not deserve this label. Indeed, some present-day opponents of positivism do not realize that they share its important anti-realism or instrumentalism.

  18. The next decade in external dosimetry

    International Nuclear Information System (INIS)

    Griffith, R.V.


    As the radiation protection community moves through the last half of the '80s and into the next decade, we can expect the requirements for external dosimetry to become increasingly more restrictive and demanding. As in other health protection fields, growing regulatory and legal pressures, together with a natural evolution in philosophy, require the health physicist to display an increasing degree of accountability, rigor, and professionalism. The good news is that, for the most part, the technology necessary to solve many of the problems will be available or not far behind. This paper describes anticipated technology. 66 refs., 10 figs

  19. Security 2020 Reduce Security Risks This Decade

    CERN Document Server

    Howard, Doug; Schneier, Bruce


    Identify real security risks and skip the hype After years of focusing on IT security, we find that hackers are as active and effective as ever. This book gives application developers, networking and security professionals, those that create standards, and CIOs a straightforward look at the reality of today's IT security and a sobering forecast of what to expect in the next decade. It debunks the media hype and unnecessary concerns while focusing on the knowledge you need to combat and prioritize the actual risks of today and beyond.IT security needs are constantly evolving; this guide examine

  20. Atoms in strong laser fields

    International Nuclear Information System (INIS)

    L'Huillier, A.


    When a high-power laser focuses into a gas of atoms, the electromagnetic field becomes of the same magnitude as the Coulomb field which binds a 1s electron in a hydrogen atom. 3 highly non-linear phenomena can happen: 1) ATI (above threshold ionization): electrons initially in the ground state absorb a large number of photons, many more than the minimum number required for ionization; 2) multiple ionization: many electrons can be emitted one at a time, in a sequential process, or simultaneously in a mechanism called direct or non-sequential; and 3) high order harmonic generation (HHG): efficient photon emission in the extreme ultraviolet range, in the form of high-order harmonics of the fundamental laser field can occur. The theoretical problem consists in solving the time dependent Schroedinger equation (TDSE) that describes the interaction of a many-electron atom with a laser field. A number of methods have been proposed to solve this problem in the case of a hydrogen atom or a single-active electron atom in a strong laser field. A large effort is presently being devoted to go beyond the single-active approximation. The understanding of the physics of the interaction between atoms and strong laser fields has been provided by a very simple model called ''simple man's theory''. A unified view of HHG, ATI, and non-sequential ionization, originating from the simple man's model and the strong field approximation, expressed in terms of electrons trajectories or quantum paths is slowly emerging. (A.C.)

  1. Strongly Interacting Light Dark Matter

    Directory of Open Access Journals (Sweden)

    Sebastian Bruggisser, Francesco Riva, Alfredo Urbano


    Full Text Available In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM can appear weakly coupled at small energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo Nambu-Goldstone Bosons and Goldstini are interesting targets for LHC missing-energy searches.

  2. Strongly interacting light dark matter

    International Nuclear Information System (INIS)

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo


    In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small-energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo-Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHC missing-energy searches.

  3. Rydberg atoms in strong fields

    International Nuclear Information System (INIS)

    Kleppner, D.; Tsimmerman, M.


    Experimental and theoretical achievements in studying Rydberg atoms in external fields are considered. Only static (or quasistatic) fields and ''one-electron'' atoms, i.e. atoms that are well described by one-electron states, are discussed. Mainly behaviour of alkali metal atoms in electric field is considered. The state of theoretical investigations for hydrogen atom in magnetic field is described, but experimental data for atoms of alkali metals are presented as an illustration. Results of the latest experimental and theoretical investigations into the structure of Rydberg atoms in strong fields are presented

  4. Scalar strong interaction hadron theory

    CERN Document Server

    Hoh, Fang Chao


    The scalar strong interaction hadron theory, SSI, is a first principles' and nonlocal theory at quantum mechanical level that provides an alternative to low energy QCD and Higgs related part of the standard model. The quark-quark interaction is scalar rather than color-vectorial. A set of equations of motion for mesons and another set for baryons have been constructed. This book provides an account of the present state of a theory supposedly still at its early stage of development. This work will facilitate researchers interested in entering into this field and serve as a basis for possible future development of this theory.

  5. Strong Plate, Weak Slab Dichotomy (United States)

    Petersen, R. I.; Stegman, D. R.; Tackley, P.


    Models of mantle convection on Earth produce styles of convection that are not observed on Earth.Moreover non-Earth-like modes, such as two-sided downwellings, are the de facto mode of convection in such models.To recreate Earth style subduction, i.e. one-sided asymmetric recycling of the lithosphere, proper treatment of the plates and plate interface are required. Previous work has identified several model features that promote subduction. A free surface or pseudo-free surface and a layer of material with a relatively low strength material (weak crust) allow downgoing plates to bend and slide past overriding without creating undue stress at the plate interface. (Crameri, et al. 2012, GRL)A low viscosity mantle wedge, possibly a result of slab dehydration, decouples the plates in the system. (Gerya et al. 2007, Geo)Plates must be composed of material which, in the case of the overriding plate, are is strong enough to resist bending stresses imposed by the subducting plate and yet, as in the case of the subducting plate, be weak enough to bend and subduct when pulled by the already subducted slab. (Petersen et al. 2015, PEPI) Though strong surface plates are required for subduction such plates may present a problem when they encounter the lower mantle.As the subducting slab approaches the higher viscosity, lower mantle stresses are imposed on the tip.Strong slabs transmit this stress to the surface.There the stress field at the plate interface is modified and potentially modifies the style of convection. In addition to modifying the stress at the plate interface, the strength of the slab affects the morphology of the slab at the base of the upper mantle. (Stegman, et al 2010, Tectonophysics)Slabs that maintain a sufficient portion of their strength after being bent require high stresses to unbend or otherwise change their shape.On the other hand slabs that are weakened though the bending process are more amenable to changes in morphology. We present the results of

  6. Five Decades: From Challenge to Acclaim. (United States)

    Melina, Vesanto


    What can make your work as a dietitian so meaningful that you begin each day with enthusiasm, and if you so choose, retain that joy in your work for 5 decades or more? Three themes are: (i) doing work that profoundly makes sense to you, (ii) inspiring others (and yourself) to make healthful choices, and (iii) moving through challenges to success. Initially it can be challenging to make a living through work that is most deeply meaningful or closest to your heart. Yet it is well worth finding the balance between practicality and movement in the desired direction. Other challenges faced by dietitians involve helping others to adopt new, more healthful lifestyle choices. As health professionals, our attitudes towards plant-based diets have changed dramatically during these past decades. This article examines our evolving perspectives of plant-based diets, and uses this as an example of movement through challenges to success and acclaim. Vegetarian and vegan diets that were considered entirely inappropriate for many stages of the life cycle in the 1970s are now seen to confer health benefits. This applies to well-designed plant-based diets, thus offering a significant role for dietitians as creative leaders in this field.

  7. Solid finite elements through three decades


    Venkatesh, DN; Shrinivasa, U


    conventionally, solid finite elements have been looked upon as just generalizations of two-dimensional finite elements. In this article we trace their development starting from the days of their inception. Keeping in tune with our perceptions on developing finite elements, without taking recourse to any extra variational techniques, we discuss a few of the techniques which have been applied to solid finite elements. Finally we critically examine our own work on formulating solid finite elemen...

  8. EDITORIAL: Strongly correlated electron systems Strongly correlated electron systems (United States)

    Ronning, Filip; Batista, Cristian


    Strongly correlated electrons is an exciting and diverse field in condensed matter physics. This special issue aims to capture some of that excitement and recent developments in the field. Given that this issue was inspired by the 2010 International Conference on Strongly Correlated Electron Systems (SCES 2010), we briefly give some history in order to place this issue in context. The 2010 International Conference on Strongly Correlated Electron Systems was held in Santa Fe, New Mexico, a reunion of sorts from the 1989 International Conference on the Physics of Highly Correlated Electron Systems that also convened in Santa Fe. SCES 2010—co-chaired by John Sarrao and Joe Thompson—followed the tradition of earlier conferences, in this century, hosted by Buzios (2008), Houston (2007), Vienna (2005), Karlsruhe (2004), Krakow (2002) and Ann Arbor (2001). Every three years since 1997, SCES has joined the International Conference on Magnetism (ICM), held in Recife (2000), Rome (2003), Kyoto (2006) and Karlsruhe (2009). Like its predecessors, SCES 2010 topics included strongly correlated f- and d-electron systems, heavy-fermion behaviors, quantum-phase transitions, non-Fermi liquid phenomena, unconventional superconductivity, and emergent states that arise from electronic correlations. Recent developments from studies of quantum magnetism and cold atoms complemented the traditional subjects and were included in SCES 2010. 2010 celebrated the 400th anniversary of Santa Fe as well as the birth of astronomy. So what's the connection to SCES? The Dutch invention of the first practical telescope and its use by Galileo in 1610 and subsequent years overturned dogma that the sun revolved about the earth. This revolutionary, and at the time heretical, conclusion required innovative combinations of new instrumentation, observation and mathematics. These same combinations are just as important 400 years later and are the foundation of scientific discoveries that were discussed

  9. Towards the Next International Lunar Decade (United States)

    Beldavs, Vidvuds


    The idea of an International Lunar Decade (ILD) germinated in work underway in the International Lunar Working Group (ILEWG) coordinated by ESA starting before 2000. Envisioned was an International Geophysical Year (IGY) inspired global collaborative undertaking to better understand the Moon, its origins and resources as a step towards lunar development and possible human settlement. By 2006 the ILD idea had evolved sufficiently that the ILEWG endorsed it and endorsement was also received from COSPAR [1] The Planetary Society under the leadership of Louis Friedman championed the ILD idea, received a grant from the Secure World Foundation to promote it at various conferences as well as to the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS). Friedman made a presentation about ILD to COPUOS in February, 2007 [2]. Despite positive interest in the idea no member state of COPUOS chose to promote it. The ILD agenda was adopted by ILEWG and largely fulfilled by the member space agencies in the decade from 2007-2014, but without UN endorsement as a global initiative. In 2013 an idea for an International Lunar Decade took hold among a group of space activists that included ideas for an International Lunar Research Park [3], an International Lunar Geophysical Year and other elements including an article published by V. Beldavs in the Space Review on January 14, 2014 [4]. These various thought streams were brought to focus at the conference "The Next Giant Leap: Leveraging Lunar Assets for Sustainable Pathways to Space", November 9-13, 2014 in Hawaii that resulted in the International Lunar Decade Declaration [3] and the formation of the working group (ILDWG) to promote implementation of ILD. In 2015 numerous organizations and influential persons were approached and informed about the idea of a framework for international collaboration sustained over a decade to gain an understanding of the Moon and its resources and to develop the technologies and

  10. Generic variation?

    DEFF Research Database (Denmark)

    Jensen, Torben Juel


    In modern Danish, a handful of pronouns may be used to refer to a generic referent. In recent decades, the second person singular pronoun du has gained ground, apparently in parallel to similar recent developments in other languages. Even though generic du may not be as old as the traditional...... generic pronoun man, it is not a new variant in Danish if we by “new” mean that it has come into existence within the last 30–40 years. To all appearances, it has been used before the influence from English became significant in the last part of the 20th century, and the generic du as such need therefore...... not be explained by contact with English, as often assumed. In order to study the spread of the generic use of du we analysed the use of pronouns with generic reference in a large sample of speakers, most of whom were recorded during sociolinguistic interviews twice – the first time in the period 1978...

  11. Strongly coupled dust coulomb clusters

    International Nuclear Information System (INIS)

    Juan Wentau; Lai Yingju; Chen Mingheng; I Lin


    The structures and motions of quasi-2-dimensional strongly coupled dust Coulomb clusters with particle number N from few to hundreds in a cylindrical rf plasma trap are studied and compared with the results from the molecular dynamic simulation using more ideal models. Shell structures with periodic packing in different shells and intershell rotational motion dominated excitations are observed at small N. As N increases, the boundary has less effect, the system recovers to the triangular lattice with isotropic vortex type cooperative excitations similar to an infinite N system except the outer shell region. The above generic behaviors are mainly determined by the system symmetry and agree with the simulation results. The detailed interaction form causes minor effect such as the fine structure of packing

  12. Probability densities in strong turbulence (United States)

    Yakhot, Victor


    In this work we, using Mellin’s transform combined with the Gaussian large-scale boundary condition, calculate probability densities (PDFs) of velocity increments P(δu,r), velocity derivatives P(u,r) and the PDF of the fluctuating dissipation scales Q(η,Re), where Re is the large-scale Reynolds number. The resulting expressions strongly deviate from the Log-normal PDF P(δu,r) often quoted in the literature. It is shown that the probability density of the small-scale velocity fluctuations includes information about the large (integral) scale dynamics which is responsible for the deviation of P(δu,r) from P(δu,r). An expression for the function D(h) of the multifractal theory, free from spurious logarithms recently discussed in [U. Frisch, M. Martins Afonso, A. Mazzino, V. Yakhot, J. Fluid Mech. 542 (2005) 97] is also obtained.

  13. Decadal variability of the NAO: Introducing an augmented NAO index (United States)

    Wang, Y.-H.; Magnusdottir, Gudrun; Stern, H.; Tian, X.; Yu, Y.


    The wintertime NAO is traditionally defined as the first Empirical Orthogonal Function of monthly sea level pressure (SLP) anomalies for all winters and therefore remains fixed in space. The associated NAO index represents the projection of SLP onto the fixed NAO pattern. The NAO index is positive when the pressure contrast between the two centers of action is particularly strong; it is negative when the contrast is weak. This index represents an incomplete description of the wintertime NAO as the pattern is found to shift location on decadal timescales. This study investigates the movement of the centers of action (or nodes) of the NAO for winter in 20-yr running windows starting in 1871. A new climate index, the Angle index, is introduced. It is a measure of the asymmetry in location of the two nodes of the NAO defined in the partially overlapping 20-yr windows. The Angle index has a value of zero only when both nodes are located on the same meridian. It increases in positive value as the curve connecting the nodes tilts more to the northeast; it becomes negative when the tilt is to the northwest. The Angle index complements the smooth NAO index, which is the traditional NAO index averaged over the 20-yr window, especially when the Angle index is strongly negative as occurred during the Arctic warming of the early to mid 20th century. Regression analysis shows that the Angle index provides additional information about climate variability beyond that provided by the smooth NAO index.

  14. The first decade of commercial space tourism (United States)

    Chang, Yi-Wei


    In order to provide a basis for assessing the future prospects and challenges of space tourism, this paper begins with a brief overview of the history of space tourism. This is followed by a discussion on market demand and current developments in the academic community, as well as the status of traffic tools, regulations and legalization. In market demand, although studies conducted in 1990s assumed the possibility of 500,000 per year in space tourists and several billion USD of annual revenue, in 2008 a relatively modest 13,000 per year was predicted. At this time traffic transport tools including the Soyuz system, CST-100, DragonRider and International Space Station (ISS) can only provide a few tens in spare seats for space tourists per year compared to the projected 20,000 plus seat capacity of the Lynx, Dream Chaser and SpaceShipTwo (SS2) fleets, which have the potential to conduct their first full suborbital test flight and first commercial flight within the coming decade. Added to this, the US government has only a regulatory regime that supports privately owned suborbital space tourism (SST) and no government funded orbital space tourism (OST). These evidences reveal a very high and advantageous potential for SST to form a space tourism industry in the coming decade, whereas the possibility of OST is relatively low. However, even though the prosperity of SST in the coming years is expectable, its maturity, reliability and safety still need to win the confidence of the general public. For examples, the announcement of changes to fuel used in the SS2 rocket engine in May 2014 and the crash of one SS2 while performing test flight on 31 October 2014 indicated the need for much careful preparation, as any accident in commercial operation could seriously damage or even kill its future prospects.

  15. Children's rights: a decade of dispute. (United States)

    Lowden, Jacqueline


    This paper attempts to raise issues surrounding children's rights against a backdrop of ethical principles and their subsequent interpretation and application in practice. Key words have been used to search a selection of electronic databases and a range of 'grey' literature has been reviewed. Over a decade ago the United Nations (1989) Convention on the Rights of the Child was ratified, with the exception of two member states (UNICEF 2000). The Human Rights Act (Department of Health 1998) became law in October 2000 in the United Kingdom (UK). Despite a decade of recommendations, guidelines and legislation, children's rights, particularly consent to health care, remain complex and inconsistent. As we move into a new era of human rights involving all members of society, it is timely for nurses in the UK to reflect on the challenges created in attempting to interpret the philosophy of such legislation because such complexity surrounds the interpretation of human rights for many other vulnerable clients within health care. The interpretation of children's rights continues to be influenced by the evolution of the meanings of childhood. Adults view children's rights from multiple perspectives of best interest, which are determined by their beliefs about children's ability to understand and consent to health care and treatment. An ability and right to consent appears not to be balanced by the right to withhold consent. Inconsistency and ambiguity persist in the law and its interpretation. Adults need to develop a more pragmatic approach to children's rights. This requires better understanding of children and their experiences of health care. Until adults develop a more pragmatic ideology in relation to children's rights then a true respect for children's autonomy will not be achieved. Consent will therefore remain an adult and legal prerogative.

  16. Variations in long term wind speed during different decades in Arabian Sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; Philip, C.S.

    .25 1948–1968 19.91 21.01 19.39 20.12 20.02 20.77 19.68 20.18 20.32 21.26 19.83 20.45 1958–1978 19.36 20.27 18.91 19.52 20.93 21.75 20.54 21.09 19.85 20.55 19.42 19.89 1968–1988 16.9 17.45 16.65 17.02 20.85 21.74 20.42 21 19.43 20.1 19.12 19.56 1978–1998 18...

  17. [Medulloblastoma: improved survival in recent decades. Unicentric experience]. (United States)

    Igual Estellés, Lucía; Berlanga Charriel, Pablo; Cañete Nieto, Adela


    The aim of the study is to analyse variations in the treatment of medulloblastoma, the most common childhood brain tumour, and its impact on survival over the past two decades, as well as its clinical and pathological features. Survival analysis of all patients under 14 years old diagnosed with medulloblastoma between January 1990 and December 2013 in a Paediatric Oncology Unit. Sixty-three patients were diagnosed and treated for medulloblastoma, with a median follow-up of 5.1 years (range 0.65-21.7 years). The overall survival (OS) at 3 and 5 years was 66±13% and 55±14%, respectively. The OS at 5 years was 44%±25% in patients diagnosed in the 1990's, showing an increase to 70%±23% (p=0.032) since 2000. Clinical prognosis factors were included in the logistic regression model: age (p=0.008), presence of metastases and/or residual tumour (p=0.007), and receiving chemotherapy with radiotherapy after surgery (p=0.008). Statistically significant differences were observed for all of them. In our institution there has been a significant increase in medulloblastoma survival in the last decades. Multivariate analysis showed that this improvement was not related to the date of diagnosis, but with the introduction of chemotherapy in adjuvant treatment. This study confirmed that clinical factors significantly associated with worse outcome were age and presence of metastases at diagnosis. Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  18. Strong Selection Significantly Increases Epistatic Interactions in the Long-Term Evolution of a Protein.

    Directory of Open Access Journals (Sweden)

    Aditi Gupta


    Full Text Available Epistatic interactions between residues determine a protein's adaptability and shape its evolutionary trajectory. When a protein experiences a changed environment, it is under strong selection to find a peak in the new fitness landscape. It has been shown that strong selection increases epistatic interactions as well as the ruggedness of the fitness landscape, but little is known about how the epistatic interactions change under selection in the long-term evolution of a protein. Here we analyze the evolution of epistasis in the protease of the human immunodeficiency virus type 1 (HIV-1 using protease sequences collected for almost a decade from both treated and untreated patients, to understand how epistasis changes and how those changes impact the long-term evolvability of a protein. We use an information-theoretic proxy for epistasis that quantifies the co-variation between sites, and show that positive information is a necessary (but not sufficient condition that detects epistasis in most cases. We analyze the "fossils" of the evolutionary trajectories of the protein contained in the sequence data, and show that epistasis continues to enrich under strong selection, but not for proteins whose environment is unchanged. The increase in epistasis compensates for the information loss due to sequence variability brought about by treatment, and facilitates adaptation in the increasingly rugged fitness landscape of treatment. While epistasis is thought to enhance evolvability via valley-crossing early-on in adaptation, it can hinder adaptation later when the landscape has turned rugged. However, we find no evidence that the HIV-1 protease has reached its potential for evolution after 9 years of adapting to a drug environment that itself is constantly changing. We suggest that the mechanism of encoding new information into pairwise interactions is central to protein evolution not just in HIV-1 protease, but for any protein adapting to a changing

  19. Strong Ideal Convergence in Probabilistic Metric Spaces

    Indian Academy of Sciences (India)

    In the present paper we introduce the concepts of strongly ideal convergent sequence and strong ideal Cauchy sequence in a probabilistic metric (PM) space endowed with the strong topology, and establish some basic facts. Next, we define the strong ideal limit points and the strong ideal cluster points of a sequence in this ...

  20. Strong ideal convergence in probabilistic metric spaces

    Indian Academy of Sciences (India)

    In the present paper we introduce the concepts of strongly ideal convergent sequence and strong ideal Cauchy sequence in a probabilistic metric (PM) space endowed with the strong topology, and establish some basic facts. Next, we define the strong ideal limit points and the strong ideal cluster points of a sequence in this ...

  1. Reconciling the signal and noise of atmospheric warming on decadal timescales (United States)

    Jones, Roger N.; Ricketts, James H.


    Interactions between externally forced and internally generated climate variations on decadal timescales is a major determinant of changing climate risk. Severe testing is applied to observed global and regional surface and satellite temperatures and modelled surface temperatures to determine whether these interactions are independent, as in the traditional signal-to-noise model, or whether they interact, resulting in step-like warming. The multistep bivariate test is used to detect step changes in temperature data. The resulting data are then subject to six tests designed to distinguish between the two statistical hypotheses, hstep and htrend. Test 1: since the mid-20th century, most observed warming has taken place in four events: in 1979/80 and 1997/98 at the global scale, 1988/89 in the Northern Hemisphere and 1968-70 in the Southern Hemisphere. Temperature is more step-like than trend-like on a regional basis. Satellite temperature is more step-like than surface temperature. Warming from internal trends is less than 40 % of the total for four of five global records tested (1880-2013/14). Test 2: correlations between step-change frequency in observations and models (1880-2005) are 0.32 (CMIP3) and 0.34 (CMIP5). For the period 1950-2005, grouping selected events (1963/64, 1968-70, 1976/77, 1979/80, 1987/88 and 1996-98), the correlation increases to 0.78. Test 3: steps and shifts (steps minus internal trends) from a 107-member climate model ensemble (2006-2095) explain total warming and equilibrium climate sensitivity better than internal trends. Test 4: in three regions tested, the change between stationary and non-stationary temperatures is step-like and attributable to external forcing. Test 5: step-like changes are also present in tide gauge observations, rainfall, ocean heat content and related variables. Test 6: across a selection of tests, a simple stepladder model better represents the internal structures of warming than a simple trend, providing strong

  2. Global Ocean Evaporation: How Well Can We Estimate Interannual to Decadal Variability? (United States)

    Robertson, Franklin R.; Bosilovich, Michael G.; Roberts, Jason B.; Wang, Hailan


    -order Taylor series analysis of wind speed, SST, near-surface stability and relative humidity variations around climatology to gauge the importance of these components. We find that the MERRA-2 evaporation record is strongly influenced by the availability of wind speed and humidity from passive microwave imagers beginning in the late 1980s as well as by the SST record. The trend over the period 1980 to present is nearly 10%. AMIP or the ERA-20C trends are much smaller. We find that ENSO-related signals involving both wind speed and thermodynamic variability remain the primary signal in the latter and are confirmed by satellite retrievals. We present uncertainty estimates based on the various data sources and discuss the implications for GEWEX water and energy budget science challenges.

  3. Remnants of strong tidal interactions

    International Nuclear Information System (INIS)

    Mcglynn, T.A.


    This paper examines the properties of stellar systems that have recently undergone a strong tidal shock, i.e., a shock which removes a significant fraction of the particles in the system, and where the shocked system has a much smaller mass than the producer of the tidal field. N-body calculations of King models shocked in a variety of ways are performed, and the consequences of the shocks are investigated. The results confirm the prediction of Jaffe for shocked systems. Several models are also run where the tidal forces on the system are constant, simulating a circular orbit around a primary, and the development of tidal radii under these static conditions appears to be a mild process which does not dramatically affect material that is not stripped. The tidal radii are about twice as large as classical formulas would predict. Remnant density profiles are compared with a sample of elliptical galaxies, and the implications of the results for the development of stellar populations and galaxies are considered. 38 refs

  4. John Strong - 1941-2006

    CERN Document Server


    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on 31 July, a few days before his 65th birthday. John started his career and obtained his PhD in a group from Westfield College, initially working on experiments at Rutherford Appleton Laboratory (RAL). From the early 1970s onwards, however, his research was focused on experiments in CERN, with several particularly notable contributions. The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras (a type of television camera) to record the sparks in the spark chambers. This highly automated system allowed Omega to be used in a similar way to bubble chambers. He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems. In these experiments the Westfield group joined forces with Italian colleagues to measure the form factors of the pion and the kaon, and the lifetime of some of the newly discovered charm particles. Such h...

  5. Strong seismic ground motion propagation

    International Nuclear Information System (INIS)

    Seale, S.; Archuleta, R.; Pecker, A.; Bouchon, M.; Mohammadioun, G.; Murphy, A.; Mohammadioun, B.


    At the McGee Creek, California, site, 3-component strong-motion accelerometers are located at depths of 166 m, 35 m and 0 m. The surface material is glacial moraine, to a depth of 30.5 m, overlying homfels. Accelerations were recorded from two California earthquakes: Round Valley, M L 5.8, November 23, 1984, 18:08 UTC and Chalfant Valley, M L 6.4, July 21, 1986, 14:42 UTC. By separating out the SH components of acceleration, we were able to determine the orientations of the downhole instruments. By separating out the SV component of acceleration, we were able to determine the approximate angle of incidence of the signal at 166 m. A constant phase velocity Haskell-Thomson model was applied to generate synthetic SH seismograms at the surface using the accelerations recorded at 166 m. In the frequency band 0.0 - 10.0 Hz, we compared the filtered synthetic records to the filtered surface data. The onset of the SH pulse is clearly seen, as are the reflections from the interface at 30.5 m. The synthetic record closely matches the data in amplitude and phase. The fit between the synthetic accelerogram and the data shows that the seismic amplification at the surface is a result of the contrast of the impedances (shear stiffnesses) of the near surface materials

  6. Strategy for the International Lunar Decade (United States)

    Beldavs, V.; Dunlop, D.; Foing, B.


    LD is a global event and process for international collaboration in space initiated by the International Lunar Exploration Working Group (ILEWG), the National Space Society and the National Science Centre FOTONIKA-LV of the University of Latvia. ILD is planned for launch in 2017, the 60th anniversary of the International Geophysical Year that marked the dawn of the space age with the launch of Sputnik. ILD is envisioned as a decade long process of international collaboration with lunar exploration concurrent with development of policies, key enabling technologies and infrastructures on the Moon and in cislunar space leading towards an eventual goal of industrial development of the Moon and economic activity beyond Earth orbit[1]. This second International Lunar Decade will build on the foundations of the ILD first proposed in by the Planetary Society in 2006 at International Conference on Exploration and Utilisation of the Moon (ICEUM), was endorsed by ICEUM participants[3], and then by ILEWG, COSPAR and other organizations. Starting in 2007, the work plan included a series of recommendations for lunar exploration missions coordinated through the ILEWG agencies and COSPAR. Advances in technology such as CubeSats and 3D printing and fundamental changes in mind-set marked by initiatives such as the Google Lunar-X prize and asteroid mining ventures have made industrial development of the Moon a thinkable proposition. The ILD to be launched in 2017 is intended to set the stage for the Moon to become a wealth generating platform for human expansion into the solar system.ILD is being organized to engage existing organizations involved in space collaboration such as COSPAR, COPUOS, ISECG, technical and scientific organizations and others that address space policy, space law, space security, governance and related concerns. Additional organizations will be involved that deal with structures, ecosystems, financing, economic development and health and life support and

  7. Decadal amplitude modulation of two types of ENSO and its relationship with the mean state

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung; An, Soon-Il [Yonsei University, Department of Atmospheric Sciences, Global Environmental Laboratory, Seoul (Korea, Republic of); Yeh, Sang-Wook [Hanyang University, Department of Environmental Marine Science, Ansan (Korea, Republic of)


    In this study, we classified two types of El Nino-Southern Oscillation (ENSO) events within the decadal ENSO amplitude modulation cycle using a long-term coupled general circulation model simulation. We defined two climate states - strong and weak ENSO amplitude periods - and separated the characteristics of ENSO that occurred in both periods. There are two major features in the characteristics of ENSO: the first is the asymmetric spatial structure between El Nino and La Nina events; the second is that the El Nino-La Nina asymmetry is reversed during strong and weak ENSO amplitude periods. El Nino events during strong (weak) ENSO amplitude periods resemble the Eastern Pacific (Central Pacific) El Nino in terms of the spatial distribution of sea surface temperature anomalies (SSTA) and physical characteristics based on heat budget analysis. The spatial pattern of the thermocline depth anomaly for strong (weak) El Nino is identical to that for weak (strong) La Nina, but for an opposite sign and slightly different amplitude. The accumulated residuals of these asymmetric anomalies dominated by an east-west contrast structure could feed into the tropical Pacific mean state. Moreover, the residual pattern associated with El Nino-La Nina asymmetry resembles the first principal component analysis (PCA) mode of tropical Pacific decadal variability, indicating that the accumulated residuals could generate the change in climate state. Thus, the intensified ENSO amplitude yields the warm residuals due to strong El Nino and weak La Nina over the eastern tropical Pacific. This linear relationship between ENSO and the mean state is strong during the mature phases of decadal oscillation, but it is weak during the transition phases. Furthermore, the second PCA mode of tropical Pacific decadal variability plays an important role in changing the phase of the first mode. Consequently, the feedback between ENSO and the mean state is positive feedback to amplify the first PCA mode

  8. Multi-decadal Arctic sea ice roughness. (United States)

    Tsamados, M.; Stroeve, J.; Kharbouche, S.; Muller, J. P., , Prof; Nolin, A. W.; Petty, A.; Haas, C.; Girard-Ardhuin, F.; Landy, J.


    The transformation of Arctic sea ice from mainly perennial, multi-year ice to a seasonal, first-year ice is believed to have been accompanied by a reduction of the roughness of the ice cover surface. This smoothening effect has been shown to (i) modify the momentum and heat transfer between the atmosphere and ocean, (ii) to alter the ice thickness distribution which in turn controls the snow and melt pond repartition over the ice cover, and (iii) to bias airborne and satellite remote sensing measurements that depend on the scattering and reflective characteristics over the sea ice surface topography. We will review existing and novel remote sensing methodologies proposed to estimate sea ice roughness, ranging from airborne LIDAR measurement (ie Operation IceBridge), to backscatter coefficients from scatterometers (ASCAT, QUICKSCAT), to multi angle maging spectroradiometer (MISR), and to laser (Icesat) and radar altimeters (Envisat, Cryosat, Altika, Sentinel-3). We will show that by comparing and cross-calibrating these different products we can offer a consistent multi-mission, multi-decadal view of the declining sea ice roughness. Implications for sea ice physics, climate and remote sensing will also be discussed.

  9. ATLAS upgrades for the next decades

    CERN Document Server

    Hopkins, Walter


    After the successful LHC operation at the center-of-mass energies of 7 and 8 TeV in 2010-2012, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity leveling. The final goal is to extend the dataset from about few hundred fb$^{-1}$ to 3000 fb$^{-1}$ by around 2035 for ATLAS and CMS. In parallel, the experiments need to be kept lockstep with the accelerator to accommodate running beyond the nominal luminosity this decade. Current planning in ATLAS envisions significant upgrades to the detector during the consolidation of the LHC to reach full LHC energy and further upgrades. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for a new all-silicon tr...

  10. Breastfeeding: what changed after a decade?

    Directory of Open Access Journals (Sweden)

    Áurea Tamami Minagawa Toryiama


    Full Text Available ABSTRACT Objective: to analyze the changes in prevalence, median duration and correlates of breastfeeding in a small city in São Paulo state, Brazil. Method: analysis of two cross-sectional studies, conducted at intervals of one decade, with 261 and 302 children younger than two years, respectively. We used Kaplan-Meier survival analysis for calculation of the median duration of breastfeeding, and Cox regression for correlates analysis, with significance level of 5%. Results: an increase of 33.4% in the prevalence of exclusive breastfeeding and 20.9% in breastfeeding was identified. Regarding the latter, the median duration increased from 7.2 to 12 months. In the most recent study, the median duration was lower in first-born children who used pacifiers, and it was not associated with breastfeeding incentive actions. Conclusions: advances in the prevalence and duration of breastfeeding were observed during the 10 year-period, however, pacifier use still remains associated to a shorter median duration of breastfeeding. Our findings contribute to highlighting the need for intensification of nursing actions in the promotion of breastfeeding, and discouragement regarding the use of pacifiers.

  11. ATLAS Upgrades for the next Decades

    CERN Document Server

    Volpi, Guido; The ATLAS collaboration


    After the successful operation at the center-of-mass energies of 7 and 8 TeV in 2010 - 2012, the LHC is ramped up and successfully took data at the center-of-mass energies of 13 TeV in 2015. Meanwhile, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity leveling. The ultimate goal is to extend the dataset from about few hundred fb−1 expected for LHC running to 3000 fb−1 by around 2035 for ATLAS and CMS. In parallel, the experiments need to be keep lockstep with the accelerator to accommodate running beyond the nominal luminosity this decade. Along with maintenance and consolidation of the detector in the past few years, ATLAS has added inner b-layer to its tracking system. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requir...

  12. Review of progress in the past decade

    International Nuclear Information System (INIS)

    Krzywosz, K.J.


    The past decade saw tremendous changes in the operation and maintenance of steam generators. Inservice inspection practices were continually upgraded to better maintain the integrity of steam generator pressure boundaries. Even though the number of plants replacing steam generators earlier than expected is increasing, concerted efforts are underway to extend the life of those remaining. Managing the safe and continued operation of steam generators is a complex task and the role of NDE is expanding. The conventional role of NDE for detecting and characterizing both degraded and new damage mechanisms is expanding to other functions such as: monitoring degradation growth rate, verifying the effectiveness of remedial measures, assisting in the establishment of defect-specific plugging limits, and assuring the inspectability of new replacement tube materials. Consequently, NDE plays a major role in improving availability and life extension of steam generators. This paper reviews the current operating conditions of steam generators in the United States, strategies for managing steam generators, and current inservice inspection practices. (author)

  13. ATLAS upgrades for the next decades

    CERN Document Server

    Hopkins, W; The ATLAS collaboration


    After the successful LHC operation at the center-of-mass energies of 7 and 8 TeV in 2010-2012, plans are actively advancing for a series of upgrades of the accelerator, culminating roughly ten years from now in the high-luminosity LHC (HL-LHC) project, delivering of the order of five times the LHC nominal instantaneous luminosity along with luminosity leveling. The final goal is to extend the dataset from about few hundred \\ifb\\ expected for LHC running to 3000 fb$^{-1}$ by around 2035 for ATLAS and CMS. In parallel, the experiments need to be keep lockstep with the accelerator to accommodate running beyond the nominal luminosity this decade. Current planning in ATLAS envisions significant upgrades to the detector during the consolidation of the LHC to reach full LHC energy and further upgrades. The challenge of coping with the HL-LHC instantaneous and integrated luminosity, along with the associated radiation levels, requires further major changes to the ATLAS detector. The designs are developing rapidly for...

  14. Two decades of PRA: What next?

    International Nuclear Information System (INIS)

    Rasmussen, N.C.


    Two decades ago, in the spring of 1972, the Reactor Safety Study was undertaken for the US Atomic Energy Commission (AEC). The goal of this study was to assess the risk to the public posed by the nuclear power plants operating in the US. Some three and one-half years later in October 1975, the study group issued its final report titled The Reactor Safety Study, also commonly known by its document number WASH 1400. Because it was issued at a time of heated public debate about nuclear safety, WASH 1400 received considerable critical review. By the late 1970s, as a result of the Lewis Report and the accident at Three Mile Island, the value of the WASH 1400 methodology was gradually recognized. A number of utilities undertook such studies of their own plants. The field of probabilistic risk assessment (PRA) developed from these efforts. Challenges remain. Among these are how to effectively communicate the results of the analysis. Just what does a probability of one in a million mean? Is there a de minimis probability - one so small that it can be ignored? How should society make decisions under substantial uncertainty? A number of these questions pose real challenges for the future

  15. Strongly interacting photons and atoms

    International Nuclear Information System (INIS)

    Alge, W.


    This thesis contains the main results of the research topics I have pursued during the my PhD studies at the University of Innsbruck and partly in collaboration with the Institut d' Optique in Orsay, France. It is divided into three parts. The first and largest part discusses the possibility of using strong standing waves as a tool to cool and trap neutral atoms in optical cavities. This is very important in the field of nonlinear optics where several successful experiments with cold atoms in cavities have been performed recently. A discussion of the optical parametric oscillator in a regime where the nonlinearity dominates the evolution is the topic of the second part. We investigated mainly the statistical properties of the cavity output of the three interactive cavity modes. Very recently a system has been proposed which promises fantastic properties. It should exhibit a giant Kerr nonlinearity with negligible absorption thus leading to a photonic turnstile device based on cold atoms in cavity. We have shown that this model suffers from overly simplistic assumptions and developed several more comprehensive approaches to study the behavior of this system. Apart from the division into three parts of different contents the thesis is divided into publications, supplements and invisible stuff. The intention of the supplements is to reach researchers which work in related areas and provide them with more detailed information about the concepts and the numerical tools we used. It is written especially for diploma and PhD students to give them a chance to use the third part of our work which is actually the largest one. They consist of a large number of computer programs we wrote to investigate the behavior of the systems in parameter regions where no hope exists to solve the equations analytically. (author)

  16. Topics in strong Langmuir turbulence

    International Nuclear Information System (INIS)

    Skoric, M.M.


    This thesis discusses certain aspects of the turbulence of a fully ionised non-isothermal plasma dominated by the Langmuir mode. Some of the basic properties of strongly turbulent plasmas are reviewed. In particular, interest is focused on the state of Langmuir turbulence, that is the turbulence of a simple externally unmagnetized plasma. The problem of the existence and dynamics of Langmuir collapse is discussed, often met as a non-linear stage of the modulational instability in the framework of the Zakharov equations (i.e. simple time-averaged dynamical equations). Possible macroscopic consequences of such dynamical turbulent models are investigated. In order to study highly non-linear collapse dynamics in its advanced stage, a set of generalized Zakharov equations are derived. Going beyond the original approximation, the author includes the effects of higher electron non-linearities and a breakdown of slow-timescale quasi-neutrality. He investigates how these corrections may influence the collapse stabilisation. Recently, it has been realised that the modulational instability in a Langmuir plasma will be accompanied by the collisionless-generation of a slow-timescale magnetic field. Accordingly, a novel physical situation has emerged which is investigated in detail. The stability of monochromatic Langmuir waves in a self-magnetized Langmuir plasma, is discussed, and the existence of a novel magneto-modulational instability shown. The wave collapse dynamics is investigated and a physical interpretation of the basic results is given. A problem of the transient analysis of an interaction of time-dependent electromagnetic pulses with linear cold plasma media is investigated. (Auth.)

  17. Promoting Strong Written Communication Skills (United States)

    Narayanan, M.


    The reason that an improvement in the quality of technical writing is still needed in the classroom is due to the fact that universities are facing challenging problems not only on the technological front but also on the socio-economic front. The universities are actively responding to the changes that are taking place in the global consumer marketplace. Obviously, there are numerous benefits of promoting strong written communication skills. They can be summarized into the following six categories. First, and perhaps the most important: The University achieves learner satisfaction. The learner has documented verbally, that the necessary knowledge has been successfully acquired. This results in learner loyalty that in turn will attract more qualified learners.Second, quality communication lowers the cost per pupil, consequently resulting in increased productivity backed by a stronger economic structure and forecast. Third, quality communications help to improve the cash flow and cash reserves of the university. Fourth, having high quality communication enables the university to justify the need for high costs of tuition and fees. Fifth, better quality in written communication skills result in attracting top-quality learners. This will lead to happier and satisfied learners, not to mention greater prosperity for the university as a whole. Sixth, quality written communication skills result in reduced complaints, thus meaning fewer hours spent on answering or correcting the situation. The University faculty and staff are thus able to devote more time on scholarly activities, meaningful research and productive community service. References Boyer, Ernest L. (1990). Scholarship reconsidered: Priorities of the Professorate.Princeton, NJ: Carnegie Foundation for the Advancement of Teaching. Hawkins, P., & Winter, J. (1997). Mastering change: Learning the lessons of the enterprise.London: Department for Education and Employment. Buzzel, Robert D., and Bradley T. Gale. (1987

  18. Patterns of Variation for the Sun and Sun-like Stars (United States)

    Radick, Richard R.; Lockwood, G. Wesley; Henry, Gregory W.; Hall, Jeffrey C.; Pevtsov, Alexei A.


    We compare patterns of variation for the Sun and 72 Sun-like stars by combining total and spectral solar irradiance measurements between 2003 and 2017 from the SORCE satellite, Strömgren b, y stellar photometry between 1993 and 2017 from Fairborn Observatory, and solar and stellar chromospheric Ca II H+K emission observations between 1992 and 2016 from Lowell Observatory. The new data and their analysis strengthen the relationships found previously between chromospheric and brightness variability on the decadal timescale of the solar activity cycle. Both chromospheric H+K and photometric b, y variability among Sun-like stars are related to average chromospheric activity by power laws on this timescale. Young active stars become fainter as their H+K emission increases, and older, less active, more Sun-age stars tend to show a pattern of direct correlation between photometric and chromospheric emission variations. The directly correlated pattern between total solar irradiance and chromospheric Ca II emission variations shown by the Sun appears to extend also to variations in the Strömgren b, y portion of the solar spectrum. Although the Sun does not differ strongly from its stellar age and spectral class mates in the activity and variability characteristics that we have now studied for over three decades, it may be somewhat unusual in two respects: (1) its comparatively smooth, regular activity cycle, and (2) its rather low photometric brightness variation relative to its chromospheric activity level and variation, perhaps indicating that facular emission and sunspot darkening are especially well-balanced on the Sun.

  19. Strong reinforcing selection in a Texas wildflower. (United States)

    Hopkins, Robin; Guerrero, Rafael F; Rausher, Mark D; Kirkpatrick, Mark


    Reinforcement, the process of increased reproductive isolation due to selection against hybrids, is an important mechanism by which natural selection contributes to speciation [1]. Empirical studies suggest that reinforcement has generated reproductive isolation in many taxa (reviewed in [2-4]), and theoretical work shows it can act under broad selective conditions [5-11]. However, the strength of selection driving reinforcement has never been measured in nature. Here, we quantify the strength of reinforcing selection in the Texas wildflower Phlox drummondii using a strategy that weds a population genetic model with field data. Reinforcement in this system is caused by variation in two loci that affect flower color [12]. We quantify sharp clines in flower color where this species comes into contact with its congener, Phlox cuspidata. We develop a spatially explicit population genetic model for these clines based on the known genetics of flower color. We fit our model to the data using likelihood, and we searched parameter space using Markov chain Monte Carlo methods. We find that selection on flower color genes generated by reinforcement is exceptionally strong. Our findings demonstrate that natural selection can play a decisive role in the evolution of reproductive isolation through the process of reinforcement. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Explicit strong stability preserving multistep Runge–Kutta methods

    KAUST Repository

    Bresten, Christopher


    High-order spatial discretizations of hyperbolic PDEs are often designed to have strong stability properties, such as monotonicity. We study explicit multistep Runge-Kutta strong stability preserving (SSP) time integration methods for use with such discretizations. We prove an upper bound on the SSP coefficient of explicit multistep Runge-Kutta methods of order two and above. Numerical optimization is used to find optimized explicit methods of up to five steps, eight stages, and tenth order. These methods are tested on the linear advection and nonlinear Buckley-Leverett equations, and the results for the observed total variation diminishing and/or positivity preserving time-step are presented.

  1. OCEAN CIRCULATION. Observing the Atlantic Meridional Overturning Circulation yields a decade of inevitable surprises. (United States)

    Srokosz, M A; Bryden, H L


    The importance of the Atlantic Meridional Overturning Circulation (AMOC) heat transport for climate is well acknowledged. Climate models predict that the AMOC will slow down under global warming, with substantial impacts, but measurements of ocean circulation have been inadequate to evaluate these predictions. Observations over the past decade have changed that situation, providing a detailed picture of variations in the AMOC. These observations reveal a surprising degree of AMOC variability in terms of the intraannual range, the amplitude and phase of the seasonal cycle, the interannual changes in strength affecting the ocean heat content, and the decline of the AMOC over the decade, both of the latter two exceeding the variations seen in climate models. Copyright © 2015, American Association for the Advancement of Science.

  2. AMOC decadal variability in Earth system models: Mechanisms and climate impacts

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, Alexey [Yale Univ., New Haven, CT (United States)


    This is the final report for the project titled "AMOC decadal variability in Earth system models: Mechanisms and climate impacts". The central goal of this one-year research project was to understand the mechanisms of decadal and multi-decadal variability of the Atlantic Meridional Overturning Circulation (AMOC) within a hierarchy of climate models ranging from realistic ocean GCMs to Earth system models. The AMOC is a key element of ocean circulation responsible for oceanic transport of heat from low to high latitudes and controlling, to a large extent, climate variations in the North Atlantic. The questions of the AMOC stability, variability and predictability, directly relevant to the questions of climate predictability, were at the center of the research work.

  3. LAB bacteriocin applications in the last decade

    Directory of Open Access Journals (Sweden)

    Ma. del Rocío López-Cuellar


    Full Text Available In the early 2000s, the expectations about bacteriocins produced by lactic acid bacteria (LABs were aimed at food applications. However, the effectiveness of bacteriocins against undesirable micro-organisms opened endless possibilities for innovative research. In the present review, we collected a database including 429 published papers and 245 granted patents (from 2004 to 2015. Based on bibliometric analysis, the progress of bacteriocin research in the last 11 years was discussed in detail. It was found that 164 patents were granted in 2010–2015, which is equivalent to 60% in comparison with previous years (i.e. only 81 patents were granted in 2004–2009. Currently, the research on bacteriocins is still gaining importance. In the realm of therapeutic strategies, about a 37% of the published research was focused on biomedical applications in the last decade. This vein of research is currently seeking for alternative solutions to problems such as cancer, systemic infections, oral-care, vaginal infections, contraception and skincare. On the other hand, food preservation, bio-nanomaterial and veterinary applications represent 29%, 25% and 9%, respectively. All this technology is being applied and will surely grow in the future, since about 31% of the patents granted since 2004 are focused on the biomedical area, 29% on food preservation, 5% on veterinary use; whereas 13% and 16% correspond to patents granted on production–purification systems and recombinant proteins or molecular modifications in the producer strains. This review contributes to the analysis of recent LAB bacteriocin applications and their role in safety, quality and improvement of human health.

  4. Older Adults' Attitudes Toward Cohabitation: Two Decades of Change. (United States)

    Brown, Susan L; Wright, Matthew R


    Our study tracks cohort change in the attitudes of adults aged 50 and older toward cohabitation from 1994 to 2012. We used data from the 1994, 2002, and 2012 waves of the General Social Survey to examine the roles of cohort replacement and intracohort change in the trend toward favorable cohabitation attitudes and to examine sociodemographic variation in patterns of support for cohabitation. Support for cohabitation accelerated over time with nearly half (46%) of older adults reporting favorable attitudes toward cohabitation in 2012 versus just 20% in 1994. This shift in older adults' attitudes largely reflected cohort replacement rather than intracohort change. Some of the factors associated with later life cohabitation experience were linked to supportive attitudes. Cohort succession is fueling the growing acceptance of cohabitation among older adults and coincides with the rapid growth in later life cohabitation that has occurred in recent decades. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail:

  5. Atmospheric forcing of decadal Baltic Sea level variability in the last 200 years. A statistical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Huenicke, B. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Kuestenforschung


    This study aims at the estimation of the impact of different atmospheric factors on the past sealevel variations (up to 200 years) in the Baltic Sea by statistically analysing the relationship between Baltic Sea level records and observational and proxy-based reconstructed climatic data sets. The focus lies on the identification and possible quantification of the contribution of sealevel pressure (wind), air-temperature and precipitation to the low-frequency (decadal and multi-decadal) variability of Baltic Sea level. It is known that the wind forcing is the main factor explaining average Baltic Sea level variability at inter-annual to decadal timescales, especially in wintertime. In this thesis it is statistically estimated to what extent other regional climate factors contribute to the spatially heterogeneous Baltic Sea level variations around the isostatic trend at multi-decadal timescales. Although the statistical analysis cannot be completely conclusive, as the potential climate drivers are all statistically interrelated to some degree, the results indicate that precipitation should be taken into account as an explanatory variable for sea-level variations. On the one hand it has been detected that the amplitude of the annual cycle of Baltic Sea level has increased throughout the 20th century and precipitation seems to be the only factor among those analysed (wind through SLP field, barometric effect, temperature and precipitation) that can account for this evolution. On the other hand, precipitation increases the ability to hindcast inter-annual variations of sea level in some regions and seasons, especially in the Southern Baltic in summertime. The mechanism by which precipitation exerts its influence on Baltic Sea level is not ascertained in this statistical analysis due to the lack of long salinity time series. This result, however, represents a working hypothesis that can be confirmed or disproved by long simulations of the Baltic Sea system - ocean

  6. Aerosols in the Atmosphere: Sources, Transport, and Multi-decadal Trends (United States)

    Chin, M.; Diehl, T.; Bian, H.; Kucsera, T.


    We present our recent studies with global modeling and analysis of atmospheric aerosols. We have used the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model and satellite and in situ data to investigate (1) long-term variations of aerosols over polluted and dust source regions and downwind ocean areas in the past three decades and the cause of the changes and (2) anthropogenic and volcanic contributions to the sulfate aerosol in the upper tropospherelower stratosphere.

  7. Solar Wind Variation with the Cycle

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... The average solar wind density, velocity and temperature measured at the Earth's orbit show specific decadal variations and trends, which are of the order of the first tens per cent during the last three solar cycles. Statistical, spectral and correlation characteristics of the solar wind are reviewed with the ...

  8. Global Estimated Net Migration Grids by Decade: 1970-2000 (United States)

    National Aeronautics and Space Administration — The Global Estimated Net Migration by Decade: 1970-2000 data set provides estimates of net migration over the three decades from 1970 to 2000. Because of the lack of...

  9. Impact of climatic change on ocean carbon fluxes. Role of the decadal variability

    International Nuclear Information System (INIS)

    Seferian, Roland


    Since the industrial revolution, oceans have absorbed roughly one quarter of the anthropogenic emissions of CO 2 , slowing down climate change. The evolution of the ocean carbon sink, paralleled to the anthropogenic CO 2 emissions, is ruled by the CO 2 as well as climate. Influence of atmospheric CO 2 in the recent evolution of the ocean carbon sink is well understood whilst this is not the case for the climate's one. Indeed, some authors claim that the recent variations of the ocean CO 2 sink can be attributed to climate change, whereas some others suggest that these latter are controlled by a decadal variability, which is poorly understood. In this thesis, we address question relative to the role of the decadal variability of the ocean carbon fluxes through the mean of numerical modeling. On one hand, we have demonstrated that ocean carbon fluxes exhibit decadal fluctuations within the high latitudes oceans. These fluctuations displays modes of 10 to 50-year long which account for 20 to 40% of the year-to-year variability. Thanks to Detection and Attribution methods applied to RECCAP project's reconstructions (1960-2005), we have then assessed whether the occurrence of fluctuations at decadal time scale could hamper the detection of the climate contribution to the recent evolution of ocean carbon fluxes. We have shown that the climate contribution is indeed not detected in the high latitude oceans due to the presence of decadal mode of variability. In the low latitude oceans instead, the weaker fluctuations of ocean carbon fluxes at decadal time scale favor the detection of climate influence in the recent variations of the CO 2 fluxes. (author) [fr

  10. Sahel rainfall and decadal to multi-decadal sea surface temperature variability

    Energy Technology Data Exchange (ETDEWEB)

    Mohino, Elsa [LOCEAN/IPSL, CNRS, Universite Pierre et Marie Curie, Paris (France); Universidad de Sevilla, Seville (Spain); Janicot, Serge [LOCEAN/IPSL, IRD, Universite Pierre et Marie Curie, Paris (France); Bader, Juergen [Bjerknes Centre for Climate Research, Bergen (Norway); Geophysical Institute, University of Bergen, Bergen (Norway)


    Decadal Sahelian rainfall variability was mainly driven by sea surface temperatures (SSTs) during the twentieth century. At the same time SSTs showed a marked long-term global warming (GW) trend. Superimposed on this long-term trend decadal and multi-decadal variability patterns are observed like the Atlantic Multidecadal Oscillation (AMO) and the inter-decadal Pacific Oscillation (IPO). Using an atmospheric general circulation model we investigate the relative contribution of each component to the Sahelian precipitation variability. To take into account the uncertainty related to the use of different SST data sets, we perform the experiments using HadISST1 and ERSSTv3 reconstructed sets. The simulations show that all three SST signals have a significant impact over West Africa: the positive phases of the GW and the IPO lead to drought over the Sahel, while a positive AMO enhances Sahel rainfall. The tropical SST warming is the main cause for the GW impact on Sahel rainfall. Regarding the AMO, the pattern of anomalous precipitation is established by the SSTs in the Atlantic and Mediterranean basins. In turn, the tropical SST anomalies control the impact of the IPO component on West Africa. Our results suggest that the low-frequency evolution of Sahel rainfall can be interpreted as the competition of three factors: the effect of the GW, the AMO and the IPO. Following this interpretation, our results show that 50% of the SST-driven Sahel drought in the 1980s is explained by the change to a negative phase of the AMO, and that the GW contribution was 10%. In addition, the partial recovery of Sahel rainfall in recent years was mainly driven by the AMO. (orig.)

  11. Long-term variations and trends in the polar E-region (United States)

    Bjoland, L. M.; Ogawa, Y.; Hall, C.; Rietveld, M.; Løvhaug, U. P.; La Hoz, C.; Miyaoka, H.


    As the EISCAT UHF radar system in Northern Scandinavia started its operations in the early 1980s, the collected data cover about three solar cycles. These long time-series provide us the opportunity to study long-term variations and trends of ionospheric parameters in the high latitude region. In the present study we have used the EISCAT Tromsø UHF data to investigate variations of the Hall conductivity and ion temperatures in the E-region around noon. Both the ion temperature and the peak altitude of the Hall conductivity are confirmed to depend strongly on solar zenith angle. However, the dependence on solar activity seems to be weak. In order to search for trends in these parameters, the ion temperature and peak altitude of the Hall conductivity data were adjusted for their seasonal and solar cycle dependence. A very weak descent (∼0.2 km/ decade) was seen in the peak altitude of the Hall conductivity. The ion temperature at 110 km shows a cooling trend (∼10 K/ decade). However, other parameters than solar zenith angle and solar activity seem to affect the ion temperature at this altitude, and a better understanding of these parameters is necessary to derive a conclusive trend. In this paper, we discuss what may cause the characteristics of the variations in the electric conductivities and ion temperatures in the high latitude region.

  12. Decadal oscillations of the aquatic chemistry of river waters in Latvia (United States)

    Porshnov, Dmitry; Klavins, Maris


    Water quality changes of surface waters can be used to assess human impact intensity, but of importance is to consider also impacts of climate change/variability and naturally occurring changes of environmental quality. In Latvia, during the recent decades a major reduction of anthropogenic pressure has happened due to restructuring of economy and industrial production, resulting in major decrease of loading of many groups of pollutants. However, trends and driving factors for other groups of substances have not been much studied. Long term (1980-2012) results of hydrochemical monitoring, performed in rivers of Latvia, are analysed during this study in connection with long-term sets of hydrological and heliophysical data, using standard statistical approaches. Our results indicate that variation of some hydrochemical values, for example COD and total Fe, show clearly visible decadal oscillated character, while variation of some other values, for example phosphate P and total P, show some individual characteristics of decadal oscillations. These results indicate the presence of a large scale, geochemical and geophysical significant process: multiannual pulse of catchment, driven by variation of solar irradiance through complex interactions between global atmospheric circulation, groundwater and surface waterbodies. The process described in our study is significant from a geochemical point of view and must be taken into account in prediction of water quality and quantity. Impacts of natural processes should be considered in the planning of environmental policy.

  13. Six Decades of Spiral Density Wave Theory (United States)

    Shu, Frank H.


    The theory of spiral density waves had its origin approximately six decades ago in an attempt to reconcile the winding dilemma of material spiral arms in flattened disk galaxies. We begin with the earliest calculations of linear and nonlinear spiral density waves in disk galaxies, in which the hypothesis of quasi-stationary spiral structure (QSSS) plays a central role. The earliest success was the prediction of the nonlinear compression of the interstellar medium and its embedded magnetic field; the earliest failure, seemingly, was not detecting color gradients associated with the migration of OB stars whose formation is triggered downstream from the spiral shock front. We give the reasons for this apparent failure with an update on the current status of the problem of OB star formation, including its relationship to the feathering substructure of galactic spiral arms. Infrared images can show two-armed, grand design spirals, even when the optical and UV images show flocculent structures. We suggest how the nonlinear response of the interstellar gas, coupled with overlapping subharmonic resonances, might introduce chaotic behavior in the dynamics of the interstellar medium and Population I objects, even though the underlying forces to which they are subject are regular. We then move to a discussion of resonantly forced spiral density waves in a planetary ring and their relationship to the ideas of disk truncation, and the shepherding of narrow rings by satellites orbiting nearby. The back reaction of the rings on the satellites led to the prediction of planet migration in protoplanetary disks, which has had widespread application in the exploding data sets concerning hot Jupiters and extrasolar planetary systems. We then return to the issue of global normal modes in the stellar disk of spiral galaxies and its relationship to the QSSS hypothesis, where the central theoretical concepts involve waves with negative and positive surface densities of energy and angular

  14. Towards Integrated Marmara Strong Motion Network (United States)

    Durukal, E.; Erdik, M.; Safak, E.; Ansal, A.; Ozel, O.; Alcik, H.; Mert, A.; Kafadar, N.; Korkmaz, A.; Kurtulus, A.


    Array (72 ch. dense accelerometric array to be installed in 2010) - Gemlik Array (a dense basin array of 8 stations, to be installed in 2010) The objectives of these systems and networks are: (1) to produce rapid earthquake intensity, damage and loss assessment information after an earthquake (in the case of IERREWS), (2) to monitor conditions of structural systems, (3) to develop real-time data processing, analysis, and damage detection and location tools (in the case of structural networks) after an extreme event, (4) to assess spatial properties of strong ground motion and ground strain, and to characterise basin response (in the case of special arrays), (5) to investigate site response and wave propagation (in the case of vertical array). Ground motion data obtained from these strong motion networks have and are being used for investigations of attenuation, spatial variation (coherence), simulation benchmarking, source modeling, site response, seismic microzonation, system identification and structural model verification and structural health control. In addition to the systems and networks outlined above there are two temporary networks: KIMNET - a dense urban noise and microtremor network consisting of 50 broadband stations expected to be operational in mid 2009, and SOSEWIN - a 20-station, self-organizing structural integrated array at Ataköy in Istanbul.

  15. An Incredible Performance in the Past Decade

    International Nuclear Information System (INIS)

    Agnihotri, Newal K.


    Mr. Michael Sellman, President and Chief Executive Officer of the Nuclear Management Company, was interviewed regarding his views on a series of questions related to the future of the nuclear industry in the United States. He stated that nuclear power has tremendous potential to provide emission-free energy, stabilize energy prices, enhance national security, and bolster the nation's balance of trade. But, there is a need to optimize the design and efficiencies of the next generation of plants to fully tap this potential. Needed are passively safe, multipurpose reactors, with reasonable staffing levels, and lower constructions costs. Tax credits or other financial incentives may be necessary in addition to some governmental protection against litigation. A strong national energy policy that supports clean-air sources of generation, a permanent repository for high-level waste, and investments in research for new technologies such as transmutation are all also essential. There is a strong need, too, to reinvigorate collegiate nuclear programs so that there are trained professionals to operate the next generation of nuclear plants, educate stakeholders, and embrace environmental groups. Information and communication technology will play a role, as will standardized training and the use of retired professionals part time. The nuclear industry has already made tremendous strides in making plants attractive to investors with its excellent safety and dramatic production increases that are the equivalent of building 19 new 1,000-megawatt generating plants. But government support to mitigate the time and dollar risk of new plant construction caused by legal or regulatory issues would also be beneficial. Near term construction would likely draw upon advanced reactor designs developed for both pressurized water and boiling water reactor technologies while in the longer term, breakthrough technology in modular gas-cooled designs or advances in pressurized reactor technology

  16. Evaluation of variational approximations

    International Nuclear Information System (INIS)

    Trevisan, L.A.


    In Feynman's approach to quantum statistical mechanics, the partition function can e represented as a path integral. A recently proposed variation method of Feynman-Kleinert is able to transform the path integral into an integral in phase space, in which the quantum fluctuations have been taken care of by introducing the effective classical potential. This method has been testes with succeed for the smooth potentials and for the singular potential of delta. The method to the strong singular potentials is applied: a quadratic potential and a linear potential both with a rigid wall at the origin. By satisfying the condition that the density of the particle be vanish at the origin, and adapted method of Feynman-Kleinert in order to improve the method is introduced. (author)

  17. The retreat of the world's mountain glaciers during recent decades

    International Nuclear Information System (INIS)

    Francou, B.; Vincent, Ch.


    Glaciers have become essential tools for measuring changes in the global environment. Here, we analyze glacier evolution during the last few decades and we wonder whether the observed retreat remains in the range of glacier fluctuations since the mid-Holocene. The main fluctuations experienced by glaciers during the last millenniums, and particularly during the Little Ice Age (-1300 A.D. to ∼1860 A.D.), are presented succinctly. The recent 1960-2005 period, well documented both by ground and remote sensing observations, shows important disparities between different massifs concerning the timing and the magnitude of glacier fluctuations, which depend on regional climatic conditions. The links between glacier mass balance evolution and climate is clear when approached from an energy balance but the variables commonly considered are only temperature and precipitation. The strong correlation existing between these variables and the mass balance evolution makes it possible to simulate glaciers in the future in function of distinct climatic scenarios. Modeling glacier retreat for the 21. century is an important goal because it will allow the impacts on water resource and sea level to be assessed. (authors)

  18. Nearly a decade-long repeatable seasonal diversity patterns of bacterioplankton communities in the eutrophic Lake Donghu (Wuhan, China). (United States)

    Yan, Qingyun; Stegen, James C; Yu, Yuhe; Deng, Ye; Li, Xinghao; Wu, Shu; Dai, Lili; Zhang, Xiang; Li, Jinjin; Wang, Chun; Ni, Jiajia; Li, Xuemei; Hu, Hongjuan; Xiao, Fanshu; Feng, Weisong; Ning, Daliang; He, Zhili; Van Nostrand, Joy D; Wu, Liyou; Zhou, Jizhong


    Uncovering which environmental factors govern community diversity patterns and how ecological processes drive community turnover are key questions related to understand the community assembly. However, the ecological mechanisms regulating long-term variations of bacterioplankton communities in lake ecosystems remain poorly understood. Here we present nearly a decade-long study of bacterioplankton communities from the eutrophic Lake Donghu (Wuhan, China) using 16S rRNA gene amplicon sequencing with MiSeq platform. We found strong repeatable seasonal diversity patterns in terms of both common (detected in more than 50% samples) and dominant (relative abundance >1%) bacterial taxa turnover. Moreover, community composition tracked the seasonal temperature gradient, indicating that temperature is a key environmental factor controlling observed diversity patterns. Total phosphorus also contributed significantly to the seasonal shifts in bacterioplankton composition. However, any spatial pattern of bacterioplankton communities across the main lake areas within season was overwhelmed by their temporal variabilities. Phylogenetic analysis further indicated that 75%-82% of community turnover was governed by homogeneous selection due to consistent environmental conditions within seasons, suggesting that the microbial communities in Lake Donghu are mainly controlled by niche-based processes. Therefore, dominant niches available within seasons might be occupied by similar combinations of bacterial taxa with modest dispersal rates throughout different lake areas. © 2017 John Wiley & Sons Ltd.

  19. Interdecadal variation of the West African summer monsoon during 1979-2010 and associated variability

    Energy Technology Data Exchange (ETDEWEB)

    Li, Huanlian [Chinese Academy of Sciences, Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Beijing (China); Graduate University of Chinese Academy of Sciences, Beijing (China); Chinese Academy of Sciences, Climate Change Research Center, Beijing (China); Wang, Huijun [Chinese Academy of Sciences, Nansen-Zhu International Research Centre, Institute of Atmospheric Physics, Beijing (China); Chinese Academy of Sciences, Climate Change Research Center, Beijing (China); Yin, Yizhou [Tsinghua University, Center for Earth System Science, Beijing (China)


    This paper addresses the interdecadal variation of the West African summer monsoon (WASM) along with its background of atmospheric circulation and possible physical mechanism over the past 32 years (1979-2010). It is indicated that the WASM starts to strengthen from 1998 as the rainfall begins to increase over western West Africa on the whole, which shows a new interdecadal variation. In this interdecadal variation, the strengthened ascending motion corresponding to enhanced divergence (convergence) movement on the upper (lower) troposphere is prone to develop the local circulation of the monsoon. Moreover, the strengthened southwestern (eastern) wind on the lower (upper) level leads to more moisture from the Atlantic and the Gulf of Guinea transported to the West African continent. In addition, the summer subtropical high over the north Atlantic and western West Africa is strong and northward, and the tropical east wind is also strong. Statistically, the weaker (stronger) the spring North Atlantic Oscillation (NAO) is, the stronger (weaker) the tropical easterly is, and then the WASM is also stronger. But the effect of the NAO on the decadal variation of the WASM is not so significant from the north Atlantic anomaly sensitivity simulation with a single model. This is also an indication that the relationship between the WASM and NAO is complicated in an interdecadal time scale and is needed further study. In terms of sea surface temperature (SST) variation, the tendency is toward warming in the subtropical north Pacific, the south Pacific and north Atlantic. Numerical simulation experiments and data analysis show that the SST variation in the north Pacific plays an important role in the latest interdecadal strengthening of the WASM during the past 32 years, while the influences of the south Pacific and the north Atlantic SST anomalies are not so significant to the associated atmospheric circulation changes. (orig.)

  20. Health technology assessment in Canada. A decade in review. (United States)

    Menon, D; Topfer, L A


    Since 1988, four government-funded health technology assessment (HTA) agencies have been established in Canada. This paper is a descriptive review of reports issued by these organizations during the period from 1988 to 1998. Publications from the national and three provincial HTA agencies in Canada were obtained and reviewed. Only the 117 assessment reports that were reported to have undergone external review were included in this analysis. Each report was classified on a standard abstraction form according to criteria such as technology type(s), assessment focus, whether a specific policy question was clearly stated and relevant decision maker(s) identified, description of search strategy and selection criteria, sources of data and assessment methods used, whether recommendations or conclusions were made, and duplication or overlap of reports. The trends in these qualities over the 10-year period were also examined. Therapeutic technologies have received the most attention from all four agencies, although the focus on devices, drugs, and procedures varied between agencies. The policy question under investigation was clearly identified in 82% of reports, and 71% clearly identified the decision maker toward whom the assessment was targeted. Efficacy or effectiveness was examined in 81% of reports, and costs were assessed in 65% of studies. These were the two most frequently examined aspects. Almost all assessments were descriptive literature reviews; 9% included meta-analyses and 32% had cost analyses or economic evaluations. Forty-four percent of reports had a clear description of the literature search strategy, and selection criteria were clearly specified in 38% of studies, but there was considerable variation among agencies in the level of description of these methods. Conclusions were clearly stated in 83% of the assessments' conclusions, and 13% had recommendations. When analyzed longitudinally, it is apparent that the quality of reports has improved markedly

  1. Advances in Understanding Decadal Climate Variability (United States)

    Busalacchi, Antonio J.


    Recently, a joint Brazil-France-U.S. program, known as PIRATA (Pilot Research moored Array in the Tropical Atlantic), was proposed to begin the deployment of moored measurement platforms in the tropical Atlantic in order to enhance the existing observational data base and subsequent understanding of the processes by which the ocean and atmosphere couple in key regions of the tropical Atlantic Ocean. Empirical studies have suggested that there are strong relationships between tropical Atlantic upper ocean variability, SST, ocean-atmosphere coupling and regional climate variability. During the early 1980's a coordinated set of surface wind, subsurface thermal structure, and subsurface current observations were obtained as part of the U.S.-France SEQUAL-FOCAL process experiment designed to observe the seasonal response of the tropical Atlantic Ocean to surface forcing. Since that time, however, the observational data base for the tropical Atlantic Ocean has disintegrated to a few ship-tracks measuring ocean temperatures and a small collection of tide gauge stations measuring sea level. A more comprehensive set of observations, modeling and empirical studies is now in order to make progress on understanding the regional climate variability. The proposed PIRATA program will use mooring platforms similar to the tropical Pacific Ocean TAO array to measure surface fluxes of momentum and heat and the corresponding changes in the upper ocean thermal structure. It is anticipated that the oceanic data from this monitoring array will also be used in a predictive mode for initialization studies of regional coupled climate models. Of particular interest are zonal and meridional modes of ocean-atmosphere variability within the tropical Atlantic basin that have significant impacts on the regional climate of the bordering continents.

  2. Enhanced Decadal Warming of the Southeast Indian Ocean During the Recent Global Surface Warming Slowdown (United States)

    Li, Yuanlong; Han, Weiqing; Zhang, Lei


    The rapid Indian Ocean warming during the early-21th century was a major heat sink for the recent global surface warming slowdown. Analysis of observational data and ocean model experiments reveals that during 2003-2012 more than half of the increased upper Indian Ocean heat content was concentrated in the southeast Indian Ocean (SEIO), causing a warming "hot spot" of 0.8-1.2 K decade-1 near the west coast of Australia. This SEIO warming was primarily induced by the enhancements of the Pacific trade winds and Indonesian throughflow associated with the Interdecadal Pacific Oscillation's (IPO) transition to its negative phase, and to a lesser degree by local atmospheric forcing within the Indian Ocean. Large-ensemble climate model simulations suggest that this warming event was likely also exacerbated by anthropogenic forcing and thus unprecedentedly strong as compared to previous IPO transition periods. Climate model projections suggest an increasing possibility of such strong decadal warming in future.

  3. Physical Biology : challenges for our second decade (United States)

    Levine, Herbert


    understand when the details of proteins and nucleic acids structure and function can be assumed constant when considering the cell. This problem is even more serious as we try to set higher sights and think of cells as constituents of tissue, organ and organism. Trying to understand higher-order biological systems is a bit like trying to play a board game where the pieces and rules are constantly changing, somehow in concert with what is happening at the scale of the game. Others will undoubtedly have their own view of what is really difficult and different about living systems. One of the roles of Physical Biology should therefore be to provide a needed forum to address some of these really difficult questions. Of course, most papers will operate with the safety-setting on, and will use established ideas in physics, either experimental or theoretical, to further our quantitative appreciation of living systems. These papers are without doubt an absolutely necessary part of the field, and we hope that our journal can serve as a home for the best of these. But, my real hope is that we can attract papers that really try to break new ground, that suggest ways in which the living world is not just an extremely messy example of the same phenomena that can be studied in non-biological contexts. Amazingly, this hope is actually shared by many leading biologists. In one of the most influential papers on cancer research in the past decades. Hanahan and Weinberg argue that 'one day, we imagine that cancer biology and treatment—at present, a patchwork quilt of cell biology, genetics, histopathology, biochemistry, immunology, and pharmacology—will become a science with a conceptual structure and logical coherence that rivals that of chemistry or physics.' We should take up the challenge, not just for cancer, and Physical Biology should help. Figuring out exactly how best to do this is now my responsibility, and I look forward to hearing from you and working with all of you, in order

  4. Physical Biology : challenges for our second decade. (United States)

    Levine, Herbert


    understand when the details of proteins and nucleic acids structure and function can be assumed constant when considering the cell. This problem is even more serious as we try to set higher sights and think of cells as constituents of tissue, organ and organism. Trying to understand higher-order biological systems is a bit like trying to play a board game where the pieces and rules are constantly changing, somehow in concert with what is happening at the scale of the game. Others will undoubtedly have their own view of what is really difficult and different about living systems. One of the roles of Physical Biology should therefore be to provide a needed forum to address some of these really difficult questions. Of course, most papers will operate with the safety-setting on, and will use established ideas in physics, either experimental or theoretical, to further our quantitative appreciation of living systems. These papers are without doubt an absolutely necessary part of the field, and we hope that our journal can serve as a home for the best of these. But, my real hope is that we can attract papers that really try to break new ground, that suggest ways in which the living world is not just an extremely messy example of the same phenomena that can be studied in non-biological contexts. Amazingly, this hope is actually shared by many leading biologists. In one of the most influential papers on cancer research in the past decades. Hanahan and Weinberg argue that 'one day, we imagine that cancer biology and treatment-at present, a patchwork quilt of cell biology, genetics, histopathology, biochemistry, immunology, and pharmacology-will become a science with a conceptual structure and logical coherence that rivals that of chemistry or physics.' We should take up the challenge, not just for cancer, and Physical Biology should help. Figuring out exactly how best to do this is now my responsibility, and I look forward to hearing from you and working with all of you, in order to

  5. Spatial and temporal variation in a mesic savanna fire regime ...

    African Journals Online (AJOL)

    Umfolozi Park, a mesic savanna area in South Africa. The study focuses at the landscape scale of tens of kilometres and at the medium term temporal scale of decades. Variation in fire regime was analysed in relation to variation in annual rainfall ...

  6. Decadal and Centennial Variability of Wet and Dry in China since Medieval Warm Period Detected from High Resolution Speleothem Data (United States)

    Chu, P. C.; Li, H.


    High-resolution δ18O data (yearly) since AD 900 from six caves (Dongge, Furong, Heshang, Wanxiang, Buddha, Shihua) in China was analyzed to detect decadal and centennial variability of wet/dry in the Asian Monsoon region. The empirical mode decomposition method (Huang et al., 1998) was used to obtain trends for the six cave data. The nine-year running average was conducted on the detrened data (Δδ18O, called anomaly) to filter out high-frequency fluctuation such as the interannual variability. Mean values of anomaly for each cave were calculated for 5 periods: (1) medieval warm period (MWD, AD 900 -AD 1100), (2) little ice age phase-1 (LIA-1, AD 1250 - AD 1550), (3) little ice age phase-2 (LIA-2, AD 1550 - AD 1850), (4) modern period-1 (MD-1, AD 1850 - AD 1950), and (5) modern period-2 (MD-2, AD 1950-2000). Anomalies in MWP and LIA-2 has opposite signs: negative anomaly (strong monsoon) in MWP and positive anomaly (weak monsoon) in LIA-2 in (Dongge, Wanxiang) cave data otherwise in (Budda, Furong, Heshang, Shihua) cave data. In LIA-1, all the six caves have positive anomalies (weak monsoon). In MD-1 (AD 1850-AD 1950), all the six caves have negative anomalies; and in MD-2 (AD 1950 - AD 2000), all the caves except Buddha have negative anomalies. It implies strong monsoon with global warming trend. Spectral analysis was also conducted on the detrended data of the six caves. The above observational studies show the following results: (1) Monsoon strength has spatial variations; (2) Stronger monsoon occurred under both warm and cold climatic conditions. One should not use the relationship of warm condition, i.e., stronger summer monsoon to interpret monsoonal climates in short time scales (less than centennial scale); and (3) Monsoon strengthening continues.

  7. A decadal tropical Pacific condition unfavorable to central Pacific El Niño (United States)

    Zhong, Wenxiu; Zheng, Xiao-Tong; Cai, Wenju


    The frequency of central Pacific (CP) El Niño events displays strong decadal variability but the associated dynamics are unclear. The Interdecadal Pacific Oscillation (IPO) and the tropical Pacific decadal variability (TPDV) are two dominant modes of tropical Pacific decadal variability that can interact with high-frequency activities. Using a 500 year control integration from the Geophysical Fluid Dynamics Laboratory Earth System Model, we find that the difference in mean state between the low-frequency and high-frequency CP El Niño periods is similar to the decadal background condition concurrently contributed by a negative IPO and a positive TPDV. This decadal state features strengthened trade winds west of the International Date Line and anomalous cool sea surface temperatures across the central tropical Pacific. As such, positive zonal advection feedback is difficult to be generated over the central to western tropical Pacific during the CP El Niño developing season, resulting in the low CP El Niño frequency.

  8. Understanding the Trends of Atmospheric Methane in the Past Decade (United States)

    Wang, J. S.; Logan, J. A.; McElroy, M. B.; Duncan, B. N.; Yantosca, R. M.


    Methane (CH4) is the second most important anthropogenic greenhouse gas after carbon dioxide. After steady growth that resulted in an increase in atmospheric CH4 concentration by a factor of 2.5 over the past three centuries, the growth rate slowed in the 1980s; superimposed on the recent trend is significant interannual variability. In this study, various sources of information are utilized to quantify the contributions of individual CH4 sources and sinks to the trends of CH4 in the past decade. The GEOS-CHEM global three-dimensional chemical transport model with assimilated meteorology is used to test a number of hypotheses regarding recent trends in emissions. The model is evaluated with observations from the NOAA CMDL network. The model accounts for interannual variations in meteorology and concentrations of OH radical. In the baseline simulation, emissions are scaled to yearly country-by-country socioeconomic and other data: livestock populations and rice harvest areas are taken from the U.N. Food and Agriculture Organization; statistics on natural gas consumption and flaring from the Carbon Dioxide Information Analysis Center are used; data on coal production from British Petroleum are used; and precipitation rate and soil temperature from NCEP reanalyses are used to calculate natural wetland emissions, the sensitivities for which are based on the results obtained by Walter et al. [2001a,b]. The absolute strength for each of the sources in the base year of 1988 is chosen so that the budget satisfies mass balance constraints for total CH4 as well as individual isotopomers while producing good agreement with 1988 observed CH4 at various sites. Preliminary results indicate that the model simulates well the horizontal and vertical distribution, seasonal cycle, and long-term trend of CH4, capturing over 70% of the variance in the observed time series between 1988 and 1998 at many sites. However, an overestimate of the growth rate in the Northern Hemisphere as well

  9. Diagnosing a Strong-Fault Model by Conflict and Consistency. (United States)

    Zhang, Wenfeng; Zhao, Qi; Zhao, Hongbo; Zhou, Gan; Feng, Wenquan


    The diagnosis method for a weak-fault model with only normal behaviors of each component has evolved over decades. However, many systems now demand a strong-fault models, the fault modes of which have specific behaviors as well. It is difficult to diagnose a strong-fault model due to its non-monotonicity. Currently, diagnosis methods usually employ conflicts to isolate possible fault and the process can be expedited when some observed output is consistent with the model's prediction where the consistency indicates probably normal components. This paper solves the problem of efficiently diagnosing a strong-fault model by proposing a novel Logic-based Truth Maintenance System (LTMS) with two search approaches based on conflict and consistency. At the beginning, the original a strong-fault model is encoded by Boolean variables and converted into Conjunctive Normal Form (CNF). Then the proposed LTMS is employed to reason over CNF and find multiple minimal conflicts and maximal consistencies when there exists fault. The search approaches offer the best candidate efficiency based on the reasoning result until the diagnosis results are obtained. The completeness, coverage, correctness and complexity of the proposals are analyzed theoretically to show their strength and weakness. Finally, the proposed approaches are demonstrated by applying them to a real-world domain-the heat control unit of a spacecraft-where the proposed methods are significantly better than best first and conflict directly with A* search methods.

  10. Atoms and clusters in strong laser fields

    NARCIS (Netherlands)

    Marchenko, T.


    This thesis describes experimental and theoretical studies on the interaction of strong infrared laser fields with atoms and atomic clusters. Part I provides an overview of the main strong-field phenomena in atoms, molecules and clusters and describes the state-of-the-art in strong-field science.

  11. Strong Bisimilarity of Simple Process Algebras

    DEFF Research Database (Denmark)

    Srba, Jirí


    We study bisimilarity and regularity problems of simple process algebras. In particular, we show PSPACE-hardness of the following problems: (i) strong bisimilarity of Basic Parallel Processes (BPP), (ii) strong bisimilarity of Basic Process Algebra (BPA), (iii) strong regularity of BPP, and (iv) ...

  12. 78 FR 15710 - Strong Sensitizer Guidance (United States)


    ... definition of ``strong sensitizer'' found at 16 CFR 1500.3(c)(5). The Commission is proposing to revise the supplemental definition of ``strong sensitizer'' due to advancements in the science of sensitization that have... document is intended to clarify the ``strong sensitizer'' definition, assist manufacturers in understanding...

  13. Extremes in East African hydroclimate and links to Indo-Pacific variability on interannual to decadal timescales (United States)

    Ummenhofer, Caroline C.; Kulüke, Marco; Tierney, Jessica E.


    East African hydroclimate exhibits considerable variability across a range of timescales, with implications for its population that depends on the region's two rainy seasons. Recent work demonstrated that current state-of-the-art climate models consistently underestimate the long rains in boreal spring over the Horn of Africa while overestimating the short rains in autumn. This inability to represent the seasonal cycle makes it problematic for climate models to project changes in East African precipitation. Here we consider whether this bias also has implications for understanding interannual and decadal variability in the East African long and short rains. Using a consistent framework with an unforced multi-century global coupled climate model simulation, the role of Indo-Pacific variability for East African rainfall is compared across timescales and related to observations. The dominant driver of East African rainfall anomalies critically depends on the timescale under consideration: Interannual variations in East African hydroclimate coincide with significant sea surface temperature (SST) anomalies across the Indo-Pacific, including those associated with the El Niño-Southern Oscillation (ENSO) in the eastern Pacific, and are linked to changes in the Walker circulation, regional winds and vertical velocities over East Africa. Prolonged drought/pluvial periods in contrast exhibit anomalous SST predominantly in the Indian Ocean and Indo-Pacific warm pool (IPWP) region, while eastern Pacific anomalies are insignificant. We assessed dominant frequencies in Indo-Pacific SST and found the eastern equatorial Pacific dominated by higher-frequency variability in the ENSO band, while the tropical Indian Ocean and IPWP exhibit lower-frequency variability beyond 10 years. This is consistent with the different contribution to regional precipitation anomalies for the eastern Pacific versus Indian Ocean and IPWP on interannual and decadal timescales, respectively. In the model

  14. Extremes in East African hydroclimate and links to Indo-Pacific variability on interannual to decadal timescales (United States)

    Ummenhofer, Caroline C.; Kulüke, Marco; Tierney, Jessica E.


    East African hydroclimate exhibits considerable variability across a range of timescales, with implications for its population that depends on the region's two rainy seasons. Recent work demonstrated that current state-of-the-art climate models consistently underestimate the long rains in boreal spring over the Horn of Africa while overestimating the short rains in autumn. This inability to represent the seasonal cycle makes it problematic for climate models to project changes in East African precipitation. Here we consider whether this bias also has implications for understanding interannual and decadal variability in the East African long and short rains. Using a consistent framework with an unforced multi-century global coupled climate model simulation, the role of Indo-Pacific variability for East African rainfall is compared across timescales and related to observations. The dominant driver of East African rainfall anomalies critically depends on the timescale under consideration: Interannual variations in East African hydroclimate coincide with significant sea surface temperature (SST) anomalies across the Indo-Pacific, including those associated with the El Niño-Southern Oscillation (ENSO) in the eastern Pacific, and are linked to changes in the Walker circulation, regional winds and vertical velocities over East Africa. Prolonged drought/pluvial periods in contrast exhibit anomalous SST predominantly in the Indian Ocean and Indo-Pacific warm pool (IPWP) region, while eastern Pacific anomalies are insignificant. We assessed dominant frequencies in Indo-Pacific SST and found the eastern equatorial Pacific dominated by higher-frequency variability in the ENSO band, while the tropical Indian Ocean and IPWP exhibit lower-frequency variability beyond 10 years. This is consistent with the different contribution to regional precipitation anomalies for the eastern Pacific versus Indian Ocean and IPWP on interannual and decadal timescales, respectively. In the model

  15. Clergy, nobility and crown in Decadência

    Directory of Open Access Journals (Sweden)

    Yi Liu


    Full Text Available In the current work I intend to inquire into the internal motives that led the Portuguese seaborne empire to decadence. After making a brief review of the historiography about the decline of Estado da Índia, I proceed to the analysis of the Crown-Church-Nobility triangle in the course of os Descobrimentos, and of their respective roles in the evolution of Portuguese empire. The absolutization of the crown, the over-expansion of the clergy and the empowerment of the aristocracy became the most conspicuous and longstanding features in the Portuguese social fabric after the country launched herself into maritime undertakings, which crippled her agriculture and retarded the industrialization. As a consequence, the rise of bourgeoisie and the transformation of mercantilist economy into the capitalist were obstructed, and a strong adventurous but non-productive spirit mixed with disdain of manual work prevailed both in metropolis and in overseas territories. In conclusion, the Portuguese decadence commenced from within rather than from without, and far prior to Dutch intrusions in Portuguese Asia, which only accelerated the decline.No presente trabalho tenciono indagar as causas internas que dirigiram o império marítimo português à decadência. Depois de uma revisitação da historiografia relativa ao declínio do Estado da Índia, procedo a uma análise do triângulo de Monarca-Igreja-Nobreza durante os Descobrimentos e dos seus papéis respectivos no evoluir do Império português. É verificável que a absolutização da Coroa, a sobre-expansão do clero e a potenciação da aristocracia tornaram-se as características mais salientes e duradouras na estrutura social portuguesa depois de o país se lançar nas façanhas marítimas, do que resultou a agricultura prejudicada e indústria atrasada. A predominância dessas três instituições, por um lado, impediu a ascensão da burguesia, assim dificultando a transformação da economia

  16. Application of strong phosphoric acid to radiochemistry

    International Nuclear Information System (INIS)

    Terada, Kikuo


    Not only inorganic and organic compounds but also natural substrances, such as accumulations in soil, are completely decomposed and distilled by heating with strong phosphoric acid for 30 to 50 minutes. As applications of strong phosphoric acid to radiochemistry, determination of uranium and boron by use of solubilization effect of this substance, titration of uranyl ion by use of sulfuric iron (II) contained in this substance, application to tracer experiment, and determination of radioactive ruthenium in environmental samples are reviewed. Strong phosphoric acid is also applied to activation analysis, for example, determination of N in pyrographite with iodate potassium-strong phosphoric acid method, separation of Os and Ru with sulfuric cerium (IV) - strong phosphoric acid method or potassium dechromate-strong phosphoric acid method, analysis of Se, As and Sb rocks and accumulations with ammonium bromide, sodium chloride and sodium bromide-strong phosphoric acid method. (Kanao, N.)

  17. Strong selection barriers explain microgeographic adaptation in wild salamander populations. (United States)

    Richardson, Jonathan L; Urban, Mark C


    Microgeographic adaptation occurs when populations evolve divergent fitness advantages across the spatial scales at which focal organisms regularly disperse. Although an increasing number of studies find evidence for microgeographic adaptation, the underlying causes often remain unknown. Adaptive divergence requires some combination of limited gene flow and strong divergent natural selection among populations. In this study, we estimated the relative influence of selection, gene flow, and the spatial arrangement of populations in shaping patterns of adaptive divergence in natural populations of the spotted salamander (Ambystoma maculatum). Within the study region, A. maculatum co-occur with the predatory marbled salamander (Ambystoma opacum) in some ponds, and past studies have established a link between predation risk and adaptive trait variation in A. maculatum. Using 14 microsatellite loci, we found a significant pattern of genetic divergence among A. maculatum populations corresponding to levels of A. opacum predation risk. Additionally, A. maculatum foraging rate was strongly associated with predation risk, genetic divergence, and the spatial relationship of ponds on the landscape. Our results indicate the sorting of adaptive genotypes by selection regime and strongly suggest that substantial selective barriers operate against gene flow. This outcome suggests that microgeographic adaptation in A. maculatum is possible because strong antagonistic selection quickly eliminates maladapted phenotypes despite ongoing and substantial immigration. Increasing evidence for microgeographic adaptation suggests a strong role for selective barriers in counteracting the homogenizing influence of gene flow. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

  18. Strong Purifying Selection at Synonymous Sites in D. melanogaster (United States)

    Lawrie, David S.; Messer, Philipp W.; Hershberg, Ruth; Petrov, Dmitri A.


    Synonymous sites are generally assumed to be subject to weak selective constraint. For this reason, they are often neglected as a possible source of important functional variation. We use site frequency spectra from deep population sequencing data to show that, contrary to this expectation, 22% of four-fold synonymous (4D) sites in Drosophila melanogaster evolve under very strong selective constraint while few, if any, appear to be under weak constraint. Linking polymorphism with divergence data, we further find that the fraction of synonymous sites exposed to strong purifying selection is higher for those positions that show slower evolution on the Drosophila phylogeny. The function underlying the inferred strong constraint appears to be separate from splicing enhancers, nucleosome positioning, and the translational optimization generating canonical codon bias. The fraction of synonymous sites under strong constraint within a gene correlates well with gene expression, particularly in the mid-late embryo, pupae, and adult developmental stages. Genes enriched in strongly constrained synonymous sites tend to be particularly functionally important and are often involved in key developmental pathways. Given that the observed widespread constraint acting on synonymous sites is likely not limited to Drosophila, the role of synonymous sites in genetic disease and adaptation should be reevaluated. PMID:23737754

  19. Seasonal variation in sports participation. (United States)

    Schüttoff, Ute; Pawlowski, Tim


    This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

  20. The role of external forcing and internal variability in regulating global mean surface temperatures on decadal timescales (United States)

    Dong, Lu; McPhaden, Michael J.


    Global mean surface temperature (GMST) shows considerable decadal variations superimposed on a pronounced warming trend, with rapid warming during 1920-1945 and 1977-2000 and warming hiatuses during 1946-1976 and 2001-2013. The prevailing view is that internally generated variations associated with the Interdecadal Pacific Oscillation (IPO) dominate decadal variations in GMST, while external forcing from greenhouse gases and anthropogenic aerosols dominate the long-term trend in GMST over the last hundred years. Here we show evidence from observations and climate models that external forcing largely governs decadal GMST variations in the historical record with internally generated variations playing a secondary role, except during those periods of IPO extremes. In particular, the warming hiatus during 1946-1976 started from a negative IPO but was later dominated by the eruption of Mount Agung in 1963, while the subsequent accelerated warming during 1977-2000 was due primarily to increased greenhouse gas forcing. The most recent warming hiatus apparent in observations occurred largely through cooling from a negative IPO extreme that overwhelmed the warming from external forcing. An important implication of this work is that when the phase of the IPO turns positive, as it did in 2014, the combination of external forcing and internal variability should lead to accelerated global warming. This accelerated warming appears to be underway, with record high GMST in 2014, 2015, and 2016.

  1. The regional MiKlip decadal forecast ensemble for Europe (United States)

    Mieruch, S.; Feldmann, H.; Schädler, G.; Lenz, C.-J.; Kothe, S.; Kottmeier, C.


    Funded by the German Ministry for Education and Research (BMBF) a major research project called MiKlip (Mittelfristige Klimaprognose, Decadal Climate Prediction) was launched and global as well as regional predictive ensemble hindcasts have been generated. The aim of the project is to demonstrate for past climate change whether predictive models have the capability of predicting climate on time scales of decades. This includes the development of a decadal forecast system, on the one hand to support decision making for economy, politics and society for decadal time spans. On the other hand, the scientific aspect is to explore the feasibility and prospects of global and regional forecasts on decadal time scales. The focus of this paper lies on the description of the regional hindcast ensemble for Europe generated by COSMO-CLM and on the assessment of the decadal variability and predictability against observations. To measure decadal variability we remove the long term bias as well as the long term linear trend from the data. Further, we applied low pass filters to the original data to separate the decadal climate signal from high frequency noise. The decadal variability and predictability assessment is applied to temperature and precipitation data for the summer and winter half-year averages/sums. The best results have been found for the prediction of decadal temperature anomalies, i.e. we have detected a distinct predictive skill and reasonable reliability. Hence it is possible to predict regional temperature variability on decadal timescales, However, the situation is less satisfactory for precipitation. Here we have found regions showing good predictability, but also regions without any predictive skill.

  2. Variational principles for locally variational forms

    International Nuclear Information System (INIS)

    Brajercik, J.; Krupka, D.


    We present the theory of higher order local variational principles in fibered manifolds, in which the fundamental global concept is a locally variational dynamical form. Any two Lepage forms, defining a local variational principle for this form, differ on intersection of their domains, by a variationally trivial form. In this sense, but in a different geometric setting, the local variational principles satisfy analogous properties as the variational functionals of the Chern-Simons type. The resulting theory of extremals and symmetries extends the first order theories of the Lagrange-Souriau form, presented by Grigore and Popp, and closed equivalents of the first order Euler-Lagrange forms of Hakova and Krupkova. Conceptually, our approach differs from Prieto, who uses the Poincare-Cartan forms, which do not have higher order global analogues

  3. Global color and albedo variations on Io (United States)

    McEwen, A.S.


    Three multispectral mosaics of Io have been produced from Voyager imaging data: a global mosaic from each of the Voyager 1 and Voyager 2 data sets and a high-resolution mosaic of the region surrounding the volcano Ra Patera. The mosaics are maps of normal albedo and color in accurate geometric map formats. Io's photometric behavior, mapped with a two-image technique, is spatially variable, especially in the bright white areas. The disk-integrated color and albedo of the satellite have been remarkably constant over recent decades, despite the volcanic activity and the many differences between Voyager 1 and 2 images (acquired just 4 months apart). This constancy is most likely due to the consistent occurrence of large Pele-type plumes with relatively dark, red deposits in the region from long 240 to 360??. A transient brightening southeast of Pele during the Voyager 1 encounter was probably due to real changes in surface and/or atmospheric materials, rather than to photometric behavior. The intrinsic spectral variability of Io, as seen in a series of two-dimensional histograms of the multispectral mosaics, consists of continuous variation among three major spectral end members. The data were mapped into five spectral units to compare them with laboratory measurements of candidate surface materials and to show the planimetric distributions. Unit 1 is best fit by the spectral reflectance of ordinary elemental sulfur, and it is closely associated with the Peletype plume deposits. Unit 2 is strongly confined to the polar caps above about latitude ??50??, but its composition is unknown. Unit 5 is probably SO2 with relatively minor contamination; it is concentrated in the equatorial region and near the long-lived Prometheus-type plumes. Units 3 and 4 are gradational between units 1 and 5. In addition to SO2 and elemental sulfur, other plausible components of the surface are polysulfur oxides, FeCl2, Na2S, and NaHS. ?? 1988.

  4. Centennial-scale variations in diatom productivity off Peru over the last 3000 years (United States)

    Fleury, Sophie; Crosta, Xavier; Schneider, Ralph; Blanz, Thomas; Ther, Olivier; Martinez, Philippe; Kim, Jung-Hyun


    The Peruvian coastal upwelling is one of the most productive systems in the global ocean, with important impacts on the carbon cycle. Primary productivity there displays strong variations at the inter-annual to decadal timescales. However, down-core investigations rarely reach sufficient temporal resolution to assess the response of productivity to climatic variations at these timescales beyond the instrumental and historical periods. We here analyzed diatom assemblages, sea-surface temperatures, nitrogen and organic carbon contents on a laminated sediment core from the Peruvian continental shelf to trace variations in regional productivity over the last 3000 years. Our record provides evidence for different climatic and oceanic conditions with more humid and less productive conditions older than 2500 Cal years BP and drier and more productive conditions younger than 2500 Cal years BP. The last 2500 years also present much stronger centennial-scale variability with the occurrence of six intervals with higher total diatom abundances and stronger percentages in upwelling-related diatom species, representative of intensified productivity, congruent to lower percentages in benthic diatoms, indicative of reduced rainfall. These six periods were synchronous to intervals of enhanced Walker circulation, suggesting a strong imprint of the Pacific zonal circulation on productivity variations off Peru. Our record also demonstrates that SSTs did not vary in phase with productivity, arguing against the idea of regional SSTs controlled by the upwelling intensity, but were rather in agreement to SST records off southern Chile, suggesting that Peruvian SSTs variations were largely controlled by oceanic currents at southern high latitudes.

  5. Dynamic evaluation of two decades of WRF-CMAQ ozone simulations over the contiguous United States (United States)

    Astitha, Marina; Luo, Huiying; Rao, S. Trivikrama; Hogrefe, Christian; Mathur, Rohit; Kumar, Naresh


    Dynamic evaluation of the fully coupled Weather Research and Forecasting (WRF)- Community Multi-scale Air Quality (CMAQ) model ozone simulations over the contiguous United States (CONUS) using two decades of simulations covering the period from 1990 to 2010 is conducted to assess how well the changes in observed ozone air quality are simulated by the model. The changes induced by variations in meteorology and/or emissions are also evaluated during the same timeframe using spectral decomposition of observed and modeled ozone time series with the aim of identifying the underlying forcing mechanisms that control ozone exceedances and making informed recommendations for the optimal use of regional-scale air quality models. The evaluation is focused on the warm season's (i.e., May-September) daily maximum 8-hr (DM8HR) ozone concentrations, the 4th highest (4th) and average of top 10 DM8HR ozone values (top10), as well as the spectrally-decomposed components of the DM8HR ozone time series using the Kolmogorov-Zurbenko (KZ) filter. Results of the dynamic evaluation are presented for six regions in the U.S., consistent with the National Oceanic and Atmospheric Administration (NOAA) climatic regions. During the earlier 11-yr period (1990-2000), the simulated and observed regional average trends are not statistically significant. During the more recent 2000-2010 period, all observed trends are statistically significant and WRF-CMAQ captures the observed downward trend in the Southwest and Midwest but under-predicts the downward trends in observations for the other regions. Observational analysis reveals that it is the magnitude of the long-term forcing that dictates the maximum ozone exceedance potential; there is a strong linear relationship between the long-term forcing and the 4th highest or the average of the top10 ozone concentrations in both observations and model output. This finding indicates that improving the model's ability to reproduce the long-term component

  6. Working towards Legitimacy: Two Decades of Teaching Games for Understanding (United States)

    Griffin, Linda L.; Brooker, Ross; Patton, Kevin


    Time and acceptance are criterion often used to measure the legitimacy and worth of an idea. Two decades have passed since the first publications that introduced Teaching Games for Understanding (TGfU) as a means to conceptualize games teaching and learning. For over two decades various professionals have advocated for TGfU as a sound idea, which…

  7. Decadal sea surface temperature variability in the subtropical South Pacific from 1726 to 1997 A.D. (United States)

    Linsley, B K; Wellington, G M; Schrag, D P


    We present a 271-year record of Sr/Ca variability in a coral from Rarotonga in the South Pacific gyre. Calibration with monthly sea surface temperature (SST) from satellite and ship measurements made in a grid measuring 1 degrees by 1 degrees over the period from 1981 to 1997 indicates that this Sr/Ca record is an excellent proxy for SST. Comparison with SST from ship measurements made since 1950 in a grid measuring 5 degrees by 5 degrees also shows that the Sr/Ca data accurately record decadal changes in SST. The entire Sr/Ca record back to 1726 shows a distinct pattern of decadal variability, with repeated decadal and interdecadal SST regime shifts greater than 0. 75 degrees C. Comparison with decadal climate variability in the North Pacific, as represented by the Pacific Decadal Oscillation index (1900-1997), indicates that several of the largest decadal-scale SST variations at Rarotonga are coherent with SST regime shifts in the North Pacific. This hemispheric symmetry suggests that tropical forcing may be an important factor in at least some of the decadal variability observed in the Pacific Ocean.

  8. Strongly correlating liquids and their isomorphs


    Pedersen, Ulf R.; Gnan, Nicoletta; Bailey, Nicholas P.; Schröder, Thomas B.; Dyre, Jeppe C.


    This paper summarizes the properties of strongly correlating liquids, i.e., liquids with strong correlations between virial and potential energy equilibrium fluctuations at constant volume. We proceed to focus on the experimental predictions for strongly correlating glass-forming liquids. These predictions include i) density scaling, ii) isochronal superposition, iii) that there is a single function from which all frequency-dependent viscoelastic response functions may be calculated, iv) that...

  9. Atom collisions in a strong electromagnetic field

    International Nuclear Information System (INIS)

    Smirnov, V.S.; Chaplik, A.V.


    It is shown that the long-range part of interatomic interaction is considerably altered in a strong electromagnetic field. Instead of the van der Waals law the potential asymptote can best be described by a dipole-dipole R -3 law. Impact broadening and the line shift in a strong nonresonant field are calculated. The possibility of bound states of two atoms being formed in a strong light field is discussed

  10. Strong paleoearthquakes along the Talas-Fergana Fault, Kyrgyzstan

    Directory of Open Access Journals (Sweden)

    A.M. Korzhenkov


    Full Text Available The Talas-Fergana Fault, the largest strike-slip structure in Centred. Asia, forms an obliquely oriented boundary between the northeastern and southwestern parts of the Tianshan mountain belt. The fault underwent active right-lateral strike-slip during the Paleozoic, with right-lateral movements being rejuvenated in the Late Cenozoic. Tectonic movements along the intracontinental strike-slip faults contribute to absorb part of the regional crustal shortening linked to the India-Eurasia collision; knowledge of strike-slip motions along the Talas-Fergana Fault are necessary for a complete assessment of the active deformation of the Tianshan orogen. To improve our understanding of the intracontinental deformation of the Tianshan mountain belt and the occurrence of strong earthquakes along the whole length of the Talas-Fergana Fault, we identify features of relief arising during strong paleoearthquakes along the Talas-Fergana Fault, fault segmentation, the length of seismogenic ruptures, and the energy and age of ancient catastrophes. We show that during neotectonic time the fault developed as a dextral strike-slip fault, with possible dextral displacements spreading to secondary fault planes north of the main fault trace. We determine rates of Holocene and Late Pleistocene dextral movements, and our radiocarbon dating indicates tens of strong earthquakes occurring along the fault zone during arid interval of 15800 years. The reoccurrence of strong earthquakes along the Talas-Fergana Fault zone during the second half of the Holocene is about 300 years. The next strong earthquake along the fault will most probably occur along its southeastern chain during the next several decades. Seismotectonic deformation parameters indicate that M > 7 earthquakes with oscillation intensity I > IX have occurred.

  11. Decadal predictability of regional scale wind speed and wind energy potentials over Central Europe

    Directory of Open Access Journals (Sweden)

    Julia Moemken


    Full Text Available Decadal predictions on timescales from one year to one decade are gaining importance since this time frame falls within the planning horizon of politics, economy and society. The present study examines the decadal predictability of regional wind speed and wind energy potentials in three generations of the MiKlip (‘Mittelfristige Klimaprognosen’ decadal prediction system. The system is based on the global Max-Planck-Institute Earth System Model (MPI-ESM, and the three generations differ primarily in the ocean initialisation. Ensembles of uninitialised historical and yearly initialised hindcast experiments are used to assess the forecast skill for 10 m wind speeds and wind energy output (Eout over Central Europe with lead times from one year to one decade. With this aim, a statistical-dynamical downscaling (SDD approach is used for the regionalisation. Its added value is evaluated by comparison of skill scores for MPI-ESM large-scale wind speeds and SDD-simulated regional wind speeds. All three MPI-ESM ensemble generations show some forecast skill for annual mean wind speed and Eout over Central Europe on yearly and multi-yearly time scales. This forecast skill is mostly limited to the first years after initialisation. Differences between the three ensemble generations are generally small. The regionalisation preserves and sometimes increases the forecast skills of the global runs but results depend on lead time and ensemble generation. Moreover, regionalisation often improves the ensemble spread. Seasonal Eout skills are generally lower than for annual means. Skill scores are lowest during summer and persist longest in autumn. A large-scale westerly weather type with strong pressure gradients over Central Europe is identified as potential source of the skill for wind energy potentials, showing a similar forecast skill and a high correlation with Eout anomalies. These results are promising towards the establishment of a decadal prediction

  12. Sex distribution and psychiatric features of child and adolescent conversion disorder across 2 decades. (United States)

    Huang, Kai-Lin; Su, Tung-Ping; Lee, Ying-Chiao; Bai, Ya-Mei; Hsu, Ju-Wei; Yang, Cheng-Hung; Chen, Ying-Shue


    Earlier research suggested female predominance in adult conversion disorder, and the strong association between conversion disorder and experiences of being abused is well known. However, the data for child and adolescent populations are limited. In Taiwan, the dramatic increase in child abuse may have some impact on the features of child and adolescent conversion disorder. This study aimed to compare the demographic characteristics, psychiatric comorbidity, and experiences of being abused in Taiwanese children and adolescents diagnosed with conversion disorder in psychiatric consultations across 2 decades. Retrospective and consecutive chart reviews were conducted for child and adolescent patients (conversion disorder in psychiatric consultations at Taipei Veterans General Hospital from 1987 to 2006. The first group included patients who were diagnosed between 1987 and 1996 (the first decade), and the second group included patients who were diagnosed between 1997 and 2006 (the second decade). A total of 42 patients diagnosed with conversion disorder were included in this study. Nineteen of the 42 subjects were diagnosed in the first decade (from 1987 to 1996), and 23 in the second decade (from 1997 to 2006). There existed among patients a tendency toward an increasing number of male subjects (p conversion disorder might have significantly changed over the past 2 decades. There is an increasing need for screening and interventions for psychiatric comorbidity and experiences of being abused in children and adolescents with conversion disorder. Because of the small sample size of our study, further studies that include multiple study sites and a larger number of patients are needed before a firm conclusion can be drawn.

  13. Predicting Regional Drought on Sub-Seasonal to Decadal Time Scales (United States)

    Schubert, Siegfried; Wang, Hailan; Suarez, Max; Koster, Randal


    Drought occurs on a wide range of time scales, and within a variety of different types of regional climates. It is driven foremost by an extended period of reduced precipitation, but it is the impacts on such quantities as soil moisture, streamflow and crop yields that are often most important from a users perspective. While recognizing that different users have different needs for drought information, it is nevertheless important to understand that progress in predicting drought and satisfying such user needs, largely hinges on our ability to improve predictions of precipitation. This talk reviews our current understanding of the physical mechanisms that drive precipitation variations on subseasonal to decadal time scales, and the implications for predictability and prediction skill. Examples are given highlighting the phenomena and mechanisms controlling precipitation on monthly (e.g., stationary Rossby waves, soil moisture), seasonal (ENSO) and decadal time scales (PD and AMO).

  14. Broadband room temperature strong coupling between quantum dots and metamaterials. (United States)

    Indukuri, Chaitanya; Yadav, Ravindra Kumar; Basu, J K


    Herein, we report the first demonstration of room temperature enhanced light-matter coupling in the visible regime for metamaterials using cooperative coupled quasi two dimensional quantum dot assemblies located at precise distances from the hyperbolic metamaterial (HMM) templates. The non-monotonic variation of the magnitude of strong coupling, manifested in terms of strong splitting of the photoluminescence of quantum dots, can be explained in terms of enhanced LDOS near the surface of such metamaterials as well as the plasmon mediated super-radiance of closely spaced quantum dots (QDs). Our methodology of enhancing broadband, room temperature, light-matter coupling in the visible regime for metamaterials opens up new possibilities of utilising these materials for a wide range of applications including QD based thresholdless nanolasers and novel metamaterial based integrated photonic devices.

  15. PANDA : Strong Interaction Studies with Antiprotons

    NARCIS (Netherlands)

    Peters, Klaus; Schmitt, Lars; Stockmanns, Tobias; Messchendorp, Johan


    The Antiproton Anihilation in Darmstadt (PANDA) collaboration at the Facility for Antiproton and Ion Research (FAIR) is a cooperation of more than 400 scientists from 19 countries. FAIR will be an accelerator facility leading the European research in nuclear and hadron physics in the coming decade.

  16. Causes of interannual to decadal variability of Gila River streamflow over the past century

    Directory of Open Access Journals (Sweden)

    M.A. Pascolini-Campbell


    Full Text Available Study region: The Gila River, New Mexico, is characterized by two peaks in streamflow: one in the winter–spring (December–May, and summer (August–September. The region is influenced both by Pacific SST variability as well as the North American Monsoon. Study focus: The mechanisms responsible for the variability of the winter–spring and summer streamflow peaks are investigated by correlation of streamflow with precipitation and sea surface temperature for 1928–2012. Decadal variability in the flow record is examined for a longer term perspective on Gila River streamflow using tree ring-based reconstructions of the Palmer Drought Severity Index (PDSI and the Standardized Precipitation Index (SPI. New hydrological insights for the region: Results indicate a strong influence of winter–spring precipitation and Pacific SST anomalies on the winter–spring streamflow, with El Niño conditions in the Pacific causing increased precipitation and streamflow. Decadal Pacific variability helps explain the transition from high winter flow in the late 20th century to lower flows in the most recent decade. The summer streamflow has a somewhat weaker correlation with precipitation and Pacific SST than the winter–spring streamflow. Its variability is more likely influenced by local North American Monsoon precipitation variability. PDSI and SPI reconstructions indicate much more severe and extended periods of droughts and pluvials in past centuries as well as periods of concurrent winter and summer drought. Keywords: Streamflow decadal variability, Drought, Pluvials, Treering, Teleconnections, North American Monsoon

  17. Strong ideal convergence in probabilistic metric spaces

    Indian Academy of Sciences (India)

    sequence and strong ideal Cauchy sequence in a probabilistic metric (PM) space endowed with the strong topology, and ... also important applications in nonlinear analysis [2]. The theory was brought to ..... for each t > 0 since each set on the right-hand side of the relation (3.1) belongs to I. Thus, by Definition 2.11 and the ...

  18. Large N baryons, strong coupling theory, quarks

    International Nuclear Information System (INIS)

    Sakita, B.


    It is shown that in QCD the large N limit is the same as the static strong coupling limit. By using the static strong coupling techniques some of the results of large N baryons are derived. The results are consistent with the large N SU(6) static quark model. (author)

  19. Optimization of strong and weak coordinates

    NARCIS (Netherlands)

    Swart, M.; Bickelhaupt, F.M.


    We present a new scheme for the geometry optimization of equilibrium and transition state structures that can be used for both strong and weak coordinates. We use a screening function that depends on atom-pair distances to differentiate strong coordinates from weak coordinates. This differentiation

  20. Strong decays of nucleon and delta resonances

    International Nuclear Information System (INIS)

    Bijker, R.; Leviatan, A.


    We study the strong couplings of the nucleon and delta resonances in a collective model. In the ensuing algebraic treatment we derive closed expressions for decay widths which are used to analyze the experimental data for strong decays into the pion and eta channels. (Author)

  1. Theoretical studies of strongly correlated fermions

    Energy Technology Data Exchange (ETDEWEB)

    Logan, D. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)


    Strongly correlated fermions are investigated. An understanding of strongly correlated fermions underpins a diverse range of phenomena such as metal-insulator transitions, high-temperature superconductivity, magnetic impurity problems and the properties of heavy-fermion systems, in all of which local moments play an important role. (author).

  2. North Atlantic Basin Tropical Cyclone Activity in Relation to Temperature and Decadal- Length Oscillation Patterns (United States)

    Wilson, Robert M.


    Yearly frequencies of North Atlantic basin tropical cyclones, their locations of origin, peak wind speeds, average peak wind speeds, lowest pressures, and average lowest pressures for the interval 1950-2008 are examined. The effects of El Nino and La Nina on the tropical cyclone parametric values are investigated. Yearly and 10-year moving average (10-yma) values of tropical cyclone parameters are compared against those of temperature and decadal-length oscillation, employing both linear and bi-variate analysis, and first differences in the 10-yma are determined. Discussion of the 2009 North Atlantic basin hurricane season, updating earlier results, is given.

  3. Aerosol influence on the recent decadal decrease in tropical cyclone activity over the western North Pacific (United States)

    Takahashi, C.; Watanabe, M.; Mori, M.


    Over the past two decades, the number of Tropical cyclone (TCs) has decreased markedly in the southeastern part of the western North Pacific (WNP) as a component of the interdecadal variation. This decrease has partially been explained by an internal low-frequency variability of sea surface temperature in the Pacific, but influences of external forcing remain unclear. We show that past changes in sulphate aerosol emissions significantly contributed to the resent observed decreasing trends in TC genesis frequency in the southeastern WNP, using multiple simulations by a global climate model. This mechanism and near-future projection of WNP TC genesis frequency will be presented.

  4. Seismic switch for strong motion measurement (United States)

    Harben, P.E.; Rodgers, P.W.; Ewert, D.W.


    A seismic switching device is described that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period. 11 figs.

  5. Browning in Desert Boundaries in Asia in Recent Decades (United States)

    Jeong, Su-Jong; Ho, Chang-Hoi; Brown, Molly E.; Kug, Jong-Seong; Piao, Shilong


    In this study, the changes in desert boundaries in Asia (Gobi, Karakum, Lut, Taklimakan, and Thar deserts) during the growing season (April October) in the years 1982 2008 were investigated by analyzing the normalized difference vegetation index (NDVI), precipitation, and temperature. In the desert boundary regions, the domain mean NDVI values increased by 7.2% per decade in 1982 1998 but decreased by 6.8% per decade thereafter. Accordingly, the bare soil areas (or nonvegetated areas) of the inside of the desert boundaries contracted by 9.8% per decade in the 1990s and expanded by 8.7% per decade in the 2000s. It is noted that the five deserts experience nearly simultaneous NDVI changes although they cover a very diverse area of Asia. In contrast, changes in temperature and precipitation in the deserts show rather diverse results. In desert boundaries located along 40 N (Gobi, Taklimakan, and Karakum), the decadal changes in vegetation greenness were mainly related to regional climate during the entire analysis period. Precipitation increased in the 1990s, providing favorable conditions for vegetation growth (i.e., greening), but precipitation reduced (19 mm per decade) and warming intensified (0.7 C per decade) in the 2000s, causing less moisture to be available for vegetation growth (i.e., browning). In desert boundaries below 40 N (Lut and Thar), although an increase in precipitation (8 mm per decade) led to greening in the 1990s, local changes in precipitation and temperature did not necessarily cause browning in the 2000s. Observed multidecadal changes in vegetation greenness in the present study suggest that under significant global and/or regional warming, changes in moisture availability for vegetation growth in desert boundaries are an important factor when understanding decadal changes in areas vulnerable to desertification over Asia.

  6. Browning in desert boundaries in Asia in recent decades (United States)

    Jeong, Su-Jong; Ho, Chang-Hoi; Brown, Molly E.; Kug, Jong-Seong; Piao, Shilong


    In this study, the changes in desert boundaries in Asia (Gobi, Karakum, Lut, Taklimakan, and Thar deserts) during the growing season (April-October) in the years 1982-2008 were investigated by analyzing the normalized difference vegetation index (NDVI), precipitation, and temperature. In the desert boundary regions, the domain mean NDVI values increased by 7.2% per decade in 1982-1998 but decreased by 6.8% per decade thereafter. Accordingly, the bare soil areas (or nonvegetated areas) of the inside of the desert boundaries contracted by 9.8% per decade in the 1990s and expanded by 8.7% per decade in the 2000s. It is noted that the five deserts experience nearly simultaneous NDVI changes although they cover a very diverse area of Asia. In contrast, changes in temperature and precipitation in the deserts show rather diverse results. In desert boundaries located along 40°N (Gobi, Taklimakan, and Karakum), the decadal changes in vegetation greenness were mainly related to regional climate during the entire analysis period. Precipitation increased in the 1990s, providing favorable conditions for vegetation growth (i.e., greening), but precipitation reduced (19 mm per decade) and warming intensified (0.7°C per decade) in the 2000s, causing less moisture to be available for vegetation growth (i.e., browning). In desert boundaries below 40°N (Lut and Thar), although an increase in precipitation (8 mm per decade) led to greening in the 1990s, local changes in precipitation and temperature did not necessarily cause browning in the 2000s. Observed multidecadal changes in vegetation greenness in the present study suggest that under significant global and/or regional warming, changes in moisture availability for vegetation growth in desert boundaries are an important factor when understanding decadal changes in areas vulnerable to desertification over Asia.

  7. Simulations of Turbulent Flows with Strong Shocks and Density Variations: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Sanjiva Lele


    The target of this SciDAC Science Application was to develop a new capability based on high-order and high-resolution schemes to simulate shock-turbulence interactions and multi-material mixing in planar and spherical geometries, and to study Rayleigh-Taylor and Richtmyer-Meshkov turbulent mixing. These fundamental problems have direct application in high-speed engineering flows, such as inertial confinement fusion (ICF) capsule implosions and scramjet combustion, and also in the natural occurrence of supernovae explosions. Another component of this project was the development of subgrid-scale (SGS) models for large-eddy simulations of flows involving shock-turbulence interaction and multi-material mixing, that were to be validated with the DNS databases generated during the program. The numerical codes developed are designed for massively-parallel computer architectures, ensuring good scaling performance. Their algorithms were validated by means of a sequence of benchmark problems. The original multi-stage plan for this five-year project included the following milestones: 1) refinement of numerical algorithms for application to the shock-turbulence interaction problem and multi-material mixing (years 1-2); 2) direct numerical simulations (DNS) of canonical shock-turbulence interaction (years 2-3), targeted at improving our understanding of the physics behind the combined two phenomena and also at guiding the development of SGS models; 3) large-eddy simulations (LES) of shock-turbulence interaction (years 3-5), improving SGS models based on the DNS obtained in the previous phase; 4) DNS of planar/spherical RM multi-material mixing (years 3-5), also with the two-fold objective of gaining insight into the relevant physics of this instability and aiding in devising new modeling strategies for multi-material mixing; 5) LES of planar/spherical RM mixing (years 4-5), integrating the improved SGS and multi-material models developed in stages 3 and 5. This final report is outlined as follows. Section 2 shows an assessment of numerical algorithms that are best suited for the numerical simulation of compressible flows involving turbulence and shock phenomena. Sections 3 and 4 deal with the canonical shock-turbulence interaction problem, from the DNS and LES perspectives, respectively. Section 5 considers the shock-turbulence inter-action in spherical geometry, in particular, the interaction of a converging shock with isotropic turbulence as well as the problem of the blast wave. Section 6 describes the study of shock-accelerated mixing through planar and spherical Richtmyer-Meshkov mixing as well as the shock-curtain interaction problem In section 7 we acknowledge the different interactions between Stanford and other institutions participating in this SciDAC project, as well as several external collaborations made possible through it. Section 8 presents a list of publications and presentations that have been generated during the course of this SciDAC project. Finally, section 9 concludes this report with the list of personnel at Stanford University funded by this SciDAC project.

  8. ESR Fine Structure of Manganese Ions in Zeolite A Detects Strong Variations of the Coordination Environment

    NARCIS (Netherlands)

    Vos, D.E. de; Weckhuysen, B.M.; Bein, T.


    The electron spin resonance spectra of Mn 2+ exchanged zeolite A have been investigated as a function of the monovalent co-cation (K + ,Na + ,Li + ,Cs + ,or NH4 + ), Mn 2+ content, recording frequency, and temperature. Three new Mn 2+ species are observed with a well-resolved fine structure; this

  9. Strong lateral variations of lithospheric mantle beneath cratons - Example from the Baltic Shield (United States)

    Pedersen, H. A.; Debayle, E.; Maupin, V.


    Understanding mechanisms for creation and evolution of Precambrian continental lithosphere requires to go beyond the large-scale seismic imaging in which shields often appear as laterally homogeneous, with a thick and fast lithosphere. We here present new results from a seismic experiment (POLENET-LAPNET) in the northern part of the Baltic Shield where we identify very high seismic velocities (Vs˜4.7 km/s) in the upper part of the mantle lithosphere and a velocity decrease of ˜0.2 km/s at approximately 150 km depth. We interpret this velocity decrease as refertilisation of the lower part of the lithosphere. This result is in contrast to the lithospheric structure immediately south of the study area, where the seismic velocities within the lithosphere are fast down to 250 km depth, as well as to that of southern Norway, where there is no indication of very high velocities in the lithospheric mantle (Vs of ˜4.4 km/s). While the relatively low velocities beneath southern Norway can tentatively be attributed to the opening of the Atlantic Ocean, the velocity decrease beneath northern Finland is not easily explained with present knowledge of surface tectonics. Our results show that shield areas may be laterally heterogeneous even over relatively short distances. Such variability may in many cases be related to lithosphere erosion and/or refertilisation at the edge of cratons, which may therefore be particularly interesting targets for seismic imaging.

  10. Somatic Variation of T-Cell Receptor Genes Strongly Associate with HLA Class Restriction

    NARCIS (Netherlands)

    Klarenbeek, Paul L.; Doorenspleet, Marieke E.; Esveldt, Rebecca E. E.; van Schaik, Barbera D. C.; Lardy, Neubury; van Kampen, Antoine H. C.; Tak, Paul P.; Plenge, Robert M.; Baas, Frank; de Bakker, Paul I. W.; de Vries, Niek


    Every person carries a vast repertoire of CD4+ T-helper cells and CD8+ cytotoxic T cells for a healthy immune system. Somatic VDJ recombination at genomic loci that encode the T-cell receptor (TCR) is a key step during T-cell development, but how a single T cell commits to become either CD4+ or CD8+

  11. Bernoulli Variational Problem and Beyond

    KAUST Repository

    Lorz, Alexander


    The question of \\'cutting the tail\\' of the solution of an elliptic equation arises naturally in several contexts and leads to a singular perturbation problem under the form of a strong cut-off. We consider both the PDE with a drift and the symmetric case where a variational problem can be stated. It is known that, in both cases, the same critical scale arises for the size of the singular perturbation. More interesting is that in both cases another critical parameter (of order one) arises that decides when the limiting behaviour is non-degenerate. We study both theoretically and numerically the values of this critical parameter and, in the symmetric case, ask if the variational solution leads to the same value as for the maximal solution of the PDE. Finally we propose a weak formulation of the limiting Bernoulli problem which incorporates both Dirichlet and Neumann boundary condition. © 2013 Springer-Verlag Berlin Heidelberg.

  12. Mechanisms of variability in decadal sea-level trends in the Baltic Sea over the 20th century (United States)

    Karabil, Sitar; Zorita, Eduardo; Hünicke, Birgit


    Coastal sea-level trends in the Baltic Sea display decadal-scale variations around a long-term centennial trend. In this study, we analyse the spatial and temporal characteristics of the decadal trend variations and investigate the links between coastal sea-level trends and atmospheric forcing on a decadal timescale. For this analysis, we use monthly means of sea-level and climatic data sets. The sea-level data set is composed of long tide gauge records and gridded sea surface height (SSH) reconstructions. Climatic data sets are composed of sea-level pressure, air temperature, precipitation, evaporation, and climatic variability indices. The analysis indicates that atmospheric forcing is a driving factor of decadal sea-level trends. However, its effect is geographically heterogeneous. This impact is large in the northern and eastern regions of the Baltic Sea. In the southern Baltic Sea area, the impacts of atmospheric circulation on decadal sea-level trends are smaller. To identify the influence of the large-scale factors other than the effect of atmospheric circulation in the same season on Baltic Sea sea-level trends, we filter out the direct signature of atmospheric circulation for each season separately on the Baltic Sea level through a multivariate linear regression model and analyse the residuals of this regression model. These residuals hint at a common underlying factor that coherently drives the decadal sea-level trends in the whole Baltic Sea. We found that this underlying effect is partly a consequence of decadal precipitation trends in the Baltic Sea basin in the previous season. The investigation of the relation between the AMO index and sea-level trends implies that this detected underlying factor is not connected to oceanic forcing driven from the North Atlantic region.

  13. Two-digit number comparison: Decade-unit and unit-decade produce the same compatibility effect with number words. (United States)

    Macizo, Pedro; Herrera, Amparo


    This study explored the processing of 2-digit number words by examining the unit-decade compatibility effect in Spanish. Participants were required to choose the larger of 2-digit number words presented in verbal notation. In compatible trials the decade and unit comparisons led to the same response (e.g., 53-68) while in incompatible trials the decade and unit comparisons led to different responses (e.g., 59-74). Participants were slower on compatible trials as compared to incompatible trials. In Experiments 2 and 3, we evaluated whether the reverse compatibility effect in Spanish was only due to a pure left-to-right encoding which favours the decade processing in this language (decade-unit order). When participants processed 2-digit number words presented in reverse form (in the unit-decade order), the same reverse compatibility effect was found. This pattern of results suggests that participants have learnt a language-dependent process for analysing written numbers which is used irrespective of the specific arrangement of units and decades in the comparison task. 2010 APA, all rights reserved.

  14. Strong and superstrong pulsed magnetic fields generation

    CERN Document Server

    Shneerson, German A; Krivosheev, Sergey I


    Strong pulsed magnetic fields are important for several fields in physics and engineering, such as power generation and accelerator facilities. Basic aspects of the generation of strong and superstrong pulsed magnetic fields technique are given, including the physics and hydrodynamics of the conductors interacting with the field as well as an account of the significant progress in generation of strong magnetic fields using the magnetic accumulation technique. Results of computer simulations as well as a survey of available field technology are completing the volume.

  15. Impurity screening in strongly coupled plasma systems

    CERN Document Server

    Kyrkos, S


    We present an overview of the problem of screening of an impurity in a strongly coupled one-component plasma within the framework of the linear response (LR) theory. We consider 3D, 2D and quasi-2D layered systems. For a strongly coupled plasma the LR can be determined by way of the known S(k) structure functions. In general, an oscillating screening potential with local overscreening and antiscreening regions emerges. In the case of the bilayer, this phenomenon becomes global, as overscreening develops in the layer of the impurity and antiscreening in the adjacent layer. We comment on the limitations of the LR theory in the strong coupling situation.

  16. The lambda sigma calculus and strong normalization

    DEFF Research Database (Denmark)

    Schack-Nielsen, Anders; Schürmann, Carsten

    Explicit substitution calculi can be classified into several dis- tinct categories depending on whether they are confluent, meta-confluent, strong normalization preserving, strongly normalizing, simulating, fully compositional, and/or local. In this paper we present a variant of the λσ-calculus......, which satisfies all seven conditions. In particular, we show how to circumvent Mellies counter-example to strong normalization by a slight restriction of the congruence rules. The calculus is implemented as the core data structure of the Celf logical framework. All meta-theoretic aspects of this work...

  17. RPS strategies to enable NASA's next decade robotic Mars missions (United States)

    Balint, Tibor S.; Jordan, James F.


    This study examines the available power system options and power selection strategies in line with the proposed mission lineup, and identifies the benefits and utility of the various options for each of the next decade launch opportunities.

  18. Decadal Anthropogenic Carbon Storage Along P16 and P02 (United States)

    Carter, B. R.; Feely, R. A.; Talley, L. D.; Cross, J. N.; Macdonald, A. M.; Mecking, S.; Siedlecki, S. A.


    The Pacific Ocean has the largest ocean basin anthropogenic carbon (Canth) inventory due to the large size of the basin. We estimate anthropogenic carbon (Canth) concentrations and decadal storages along the meridional P16 and zonal P02 lines since the mid 90s using a modified version of the extended multiple linear regression (EMLR) technique with data from the WOCE, CLIVAR, and GO-SHIP occupations of these lines. We present our estimates and map the aragonite saturation state (ΩA) decreases and saturation horizon shoaling resulting from continued Canth storage. The average storage rate was larger along both sections during the most recent decade (2000's to 2010's) than during the previous decade (1990's to 2000's), especially along P02. Significant decadal concentration increases were found in the mixed layers, shallow thermoclines, mode waters, and portions of the intermediate water masses.

  19. Reconstructing Monsoon Variations in India - Evidence from Speleothems (United States)

    Breitenbach, S. F.; Lechleitner, F.; Plessen, B.; Marwan, N.; Cheng, H.; Adkins, J. F.; Haug, G. H.


    Indian summer monsoon (ISM) rainfall is of vital importance for ca. one fifth of the world's population, yet little is known about the factors governing its variability. Changing seasonality and/or rainfall intensity have profound impacts on the well-being of Asian agriculture-based societies. Most proxy-records from the Indian realm lack temporal resolution and age control sufficient to allow detailed analysis of high-frequency ISM rainfall variations. Low spatial coverage further restricts understanding spatial differences and the interactions between subsystems of the Asian summer monsoon, limiting understanding, not to mention reliable forecasting. Here, we summarize available information on rainfall changes over India, as reflected in speleothems. Suitable stalagmites offer highly precise chronologies and multi-proxy time series. Oxygen isotope and greyscale time series can track ISM intensity. Using published and new records from NE India, we present evidence for significant rainfall changes during the Holocene. Available proxy records show that while long-term ISM rainfall pattern changed in concert with supra-regional variations of the Asian summer monsoon, sub-decadal-scale ISM variations are influenced by local and regional influences. Complex network analysis of Indian and Chinese proxy data reveals that during the Medieval Warm Period ISM and East Asian summer monsoon (EASM) were more tightly linked, with a seemingly strong ISM influence on the EASM. During the cooler Little Ice Age however, the ISM and EASM connection weakened and local effects exerted influence on both sub-systems of the Asian monsoon. In order to allow detailed insights in spatio-temporal variations of the ISM and external teleconnections, precisely dated high-resolution time series must be obtained from various places in the Indian peninsula and beyond. Only a combination of high temporal and spatial coverage will allow assessments of the likelihood of drought recurrence in a given

  20. Atlantic effects on recent decadal trends in global monsoon


    KAMAE, Youichi; LI, Xichen; XIE, Shang-Ping; UEDA, Hiroaki


    Natural climate variability contributes to recent decadal climate trends. Specifically the trends during the satellite era since 1979 include Atlantic and Indian Ocean warming and Pacific cooling associated with phase shifts of the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation, and enhanced global monsoon (GM) circulation and rainfall especially in the Northern Hemisphere. Here we evaluate effects of the oceanic changes on the global and regional monsoon trends by part...

  1. Variational Monte Carlo Technique

    Indian Academy of Sciences (India)


    RESONANCE ⎜ August 2014. GENERAL ⎜ ARTICLE. Variational Monte Carlo Technique. Ground State Energies of Quantum Mechanical Systems. Sukanta Deb. Keywords. Variational methods, Monte. Carlo techniques, harmonic os- cillators, quantum mechanical systems. Sukanta Deb is an. Assistant Professor in the.

  2. Decadal and interannual variability of the Indian Ocean SST (United States)

    Krishnamurthy, Lakshmi; Krishnamurthy, V.


    The variability of the Indian Ocean on interannual and decadal timescales is investigated in observations, coupled model simulation and model experiment. The Indian Ocean Dipole (IOD) mode was specifically analyzed using a data-adaptive method. This study reveals one decadal mode and two interannual modes in the sea surface temperature (SST) of the IOD. The decadal mode in the IOD is associated with the Pacific Decadal Oscillation (PDO) of the North Pacific SST. The two interannual modes are related to the biennial and canonical components of El Niño-Southern Oscillation (ENSO), consistent with previous studies. This study hypothesizes that the relation between the Indian Ocean and the North Pacific on decadal scale may be through the northerly winds from the western North Pacific. The long simulation of Community Climate System Model version 4 also indicates the presence of IOD modes associated with the decadal PDO and canonical ENSO modes. However, the model fails to simulate the biennial ENSO mode in the Indian Ocean. The relation between the Indian Ocean and North Pacific Ocean is further supported by the regionally de-coupled model experiment.

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


    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

  4. Strong Coupling Corrections in Quantum Thermodynamics (United States)

    Perarnau-Llobet, M.; Wilming, H.; Riera, A.; Gallego, R.; Eisert, J.


    Quantum systems strongly coupled to many-body systems equilibrate to the reduced state of a global thermal state, deviating from the local thermal state of the system as it occurs in the weak-coupling limit. Taking this insight as a starting point, we study the thermodynamics of systems strongly coupled to thermal baths. First, we provide strong-coupling corrections to the second law applicable to general systems in three of its different readings: As a statement of maximal extractable work, on heat dissipation, and bound to the Carnot efficiency. These corrections become relevant for small quantum systems and vanish in first order in the interaction strength. We then move to the question of power of heat engines, obtaining a bound on the power enhancement due to strong coupling. Our results are exemplified on the paradigmatic non-Markovian quantum Brownian motion.

  5. Finding quantum effects in strong classical potentials (United States)

    Hegelich, B. Manuel; Labun, Lance; Labun, Ou Z.


    The long-standing challenge to describing charged particle dynamics in strong classical electromagnetic fields is how to incorporate classical radiation, classical radiation reaction and quantized photon emission into a consistent unified framework. The current, semiclassical methods to describe the dynamics of quantum particles in strong classical fields also provide the theoretical framework for fundamental questions in gravity and hadron-hadron collisions, including Hawking radiation, cosmological particle production and thermalization of particles created in heavy-ion collisions. However, as we show, these methods break down for highly relativistic particles propagating in strong fields. They must therefore be improved and adapted for the description of laser-plasma experiments that typically involve the acceleration of electrons. Theory developed from quantum electrodynamics, together with dedicated experimental efforts, offer the best controllable context to establish a robust, experimentally validated foundation for the fundamental theory of quantum effects in strong classical potentials.

  6. The Charm and Beauty of Strong Interactions (United States)

    El-Bennich, Bruno


    We briefly review common features and overlapping issues in hadron and flavor physics focussing on continuum QCD approaches to heavy bound states, their mass spectrum and weak decay constants in different strong interaction models.

  7. Atomica ionization by strong coherent radiation

    International Nuclear Information System (INIS)

    Brandi, H.S.; Davidovich, L.


    The relation among the three most frequently used non-perturbative methods proposed to study the ionization of atoms by strong electromagnetic fields is established. Their range of validity is also determined. (Author) [pt

  8. Perturbation of an exact strong gravity solution

    International Nuclear Information System (INIS)

    Baran, S.A.


    Perturbations of an exact strong gravity solution are investigated. It is shown, by using the new multipole expansions previously presented, that this exact and static spherically symmetric solution is stable under odd parity perturbations. (author)

  9. Strong-force theorists scoop Noble Prize

    CERN Multimedia

    Durrani, Matin


    Three US theorists have shared the 2004 Nobel Prize in Physics "for the discovery of asymptotic freedom in the theory of the strong interaction". Their theoretical work explains why quarks behave almost as free particles at high energies (½ page)

  10. Calculating hadronic properties in strong QCD

    International Nuclear Information System (INIS)

    Pennington, M.R.


    This talk gives a brief review of the progress that has been made in calculating the properties of hadrons in strong QCD. In keeping with this meeting I will concentrate on those properties that can be studied with electromagnetic probes. Though perturbative QCD is highly successful, it only applies in a limited kinematic regime, where hard scattering occur, and the quarks move in the interaction region as if they are free, pointlike objects. However, the bulk of strong interactions are governed by the long distance regime, where the strong interaction is strong. It is this regime of length scales of the order of a Fermi, that determines the spectrum of light hadrons and their properties. The calculation of these properties requires an understanding of non-perturbative QCD, of confinement and chiral symmetry breaking. (author)

  11. Reed Warbler Hosts Fine-Tune their Defenses to Track Three Decades of Cuckoo Decline (United States)

    Thorogood, Rose; Davies, Nicholas B


    Interactions between avian hosts and brood parasites can provide a model for how animals adapt to a changing world. Reed warbler (Acrocephalus scirpaceus) hosts employ costly defenses to combat parasitism by common cuckoos (Cuculus canorus). During the past three decades cuckoos have declined markedly across England, reducing parasitism at our study site (Wicken Fen) from 24% of reed warbler nests in 1985 to 1% in 2012. Here we show with experiments that host mobbing and egg rejection defenses have tracked this decline in local parasitism risk: the proportion of reed warbler pairs mobbing adult cuckoos (assessed by responses to cuckoo mounts and models) has declined from 90% to 38%, and the proportion rejecting nonmimetic cuckoo eggs (assessed by responses to model eggs) has declined from 61% to 11%. This is despite no change in response to other nest enemies or mimetic model eggs. Individual variation in both defenses is predicted by parasitism risk during the host’s egg-laying period. Furthermore, the response of our study population to temporal variation in parasitism risk can also explain spatial variation in egg rejection behavior in other populations across Europe. We suggest that spatial and temporal variation in parasitism risk has led to the evolution of plasticity in reed warbler defenses. PMID:24299407

  12. Impacts of IOD, ENSO and ENSO Modoki on the Australian Winter Wheat Yields in Recent Decades (United States)

    Yuan, Chaoxia; Yamagata, Toshio


    Impacts of the Indian Ocean Dipole (IOD), two different types of El Niño/Southern Oscillation (ENSO): canonical ENSO and ENSO Modoki, on the year-to-year winter wheat yield variations in Australia have been investigated. It is found that IOD plays a dominant role in the recent three decades; the wheat yield is reduced (increased) by -28.4% (12.8%) in the positive (negative) IOD years. Although the canonical ENSO appears to be responsible for the wheat yield variations, its influences are largely counted by IOD owing to their frequent co-occurrence. In contrast, the ENSO Modoki may have its distinct impacts on the wheat yield variations, but they are much smaller compared to those of IOD. Both the observed April-May and the predicted September-November IOD indices by the SINTEX-F ocean-atmosphere coupled model initialized on April 1st just before the sowing season explain ~15% of the observed year-to-year wheat yield variances. The present study may lead to a possible scheme for predicting wheat yield variations in Australia in advance by use of simple climate mode indices.

  13. Algebra of strong and electroweak interactions

    International Nuclear Information System (INIS)

    Bolokhov, S.V.; Vladimirov, Yu.S.


    The algebraic approach to describing the electroweak and strong interactions is considered within the frames of the binary geometrophysics, based on the principles of the Fokker-Feynman direct interparticle interaction theories of the Kaluza-Klein multidimensional geometrical models and the physical structures theory. It is shown that in this approach the electroweak and strong elementary particles interaction through the intermediate vector bosons, are characterized by the subtypes of the algebraic classification of the complex 3 x 3-matrices [ru

  14. Juvenile recruitment in loggerhead sea turtles linked to decadal changes in ocean circulation. (United States)

    Ascani, François; Van Houtan, Kyle S; Di Lorenzo, Emanuele; Polovina, Jeffrey J; Jones, T Todd


    Given the threats of climate change, understanding the relationship of climate with long-term population dynamics is critical for wildlife conservation. Previous studies have linked decadal climate oscillations to indices of juvenile recruitment in loggerhead sea turtles (Caretta caretta), but without a clear understanding of mechanisms. Here, we explore the underlying processes that may explain these relationships. Using the eddy-resolving Ocean General Circulation Model for the Earth Simulator, we generate hatch-year trajectories for loggerhead turtles emanating from Japan over six decades (1950-2010). We find that the proximity of the high-velocity Kuroshio Current to the primary nesting areas in southern Japan is remarkably stable and that hatchling dispersal to oceanic habitats itself does not vary on decadal timescales. However, we observe a shift in latitudes of trajectories, consistent with the Pacific Decadal Oscillation (PDO). In a negative PDO phase, the Kuroshio Extension Current (KEC) is strong and acts as a physical barrier to the northward transport of neonates. As a result, hatch-year trajectories remain mostly below 35°N in the warm, unproductive region south of the Transition Zone Chlorophyll Front (TZCF). During a positive PDO phase, however, the KEC weakens facilitating the neonates to swim north of the TZCF into cooler and more productive waters. As a result, annual cohorts from negative PDO years may face a lack of resources, whereas cohorts from positive PDO years may find sufficient resources during their pivotal first year. These model outputs indicate that the ocean circulation dynamics, combined with navigational swimming behavior, may be a key factor in the observed decadal variability of sea turtle populations. © 2016 John Wiley & Sons Ltd.

  15. Studying Variation in Tunes

    NARCIS (Netherlands)

    Janssen, B.; van Kranenburg, P.


    Variation in music can be caused by different phenomena: conscious, creative manipulation of musical ideas; but also unconscious variation during music recall. It is the latter phenomenon that we wish to study: variation which occurs in oral transmission, in which a melody is taught without the help

  16. Manipulating light with strongly modulated photonic crystals

    International Nuclear Information System (INIS)

    Notomi, Masaya


    Recently, strongly modulated photonic crystals, fabricated by the state-of-the-art semiconductor nanofabrication process, have realized various novel optical properties. This paper describes the way in which they differ from other optical media, and clarifies what they can do. In particular, three important issues are considered: light confinement, frequency dispersion and spatial dispersion. First, I describe the latest status and impact of ultra-strong light confinement in a wavelength-cubic volume achieved in photonic crystals. Second, the extreme reduction in the speed of light is reported, which was achieved as a result of frequency dispersion management. Third, strange negative refraction in photonic crystals is introduced, which results from their unique spatial dispersion, and it is clarified how this leads to perfect imaging. The last two sections are devoted to applications of these novel properties. First, I report the fact that strong light confinement and huge light-matter interaction enhancement make strongly modulated photonic crystals promising for on-chip all-optical processing, and present several examples including all-optical switches/memories and optical logics. As a second application, it is shown that the strong light confinement and slow light in strongly modulated photonic crystals enable the adiabatic tuning of light, which leads to various novel ways of controlling light, such as adiabatic frequency conversion, efficient optomechanics systems, photon memories and photons pinning.

  17. Hospitalization due to drug use did not change after a decade of the Psychiatric Reform (United States)

    Balbinot, Alexandre Dido; Horta, Rogério Lessa; da Costa, Juvenal Soares Dias; Araújo, Renata Brasil; Poletto, Simone; Teixeira, Marina Bressaneli


    ABSTRACT OBJECTIVE To investigate whether the psychiatric hospitalization rates due to use of psychoactive substances and average time of hospitalization suffered any changes after the first decade of effective implementation of the psychiatric reform in Brazil. METHODS This article examines the evolution of hospitalizations due to disorders arising from the use of alcohol or other substances in the state of Santa Catarina, Southern Brazil, from 2000 to 2012. This is an ecological, time-series study, which uses data from admissions obtained by the Informatics Service of the Brazilian Unified Health System. Hospitalization rates by 100,000 inhabitants and average time of occupancy of beds were estimated. Coefficients of variation of these rates were estimated by Poisson Regression. RESULTS The total and male hospitalization rates did not vary (p = 0.056 and p = 0.244, respectively). We observed an increase of 3.0% for the female sex (p = 0.049). We did not observe any significant variation for occupancy time of beds. CONCLUSIONS The deployment of services triggered by the Brazilian psychiatric reform was not accompanied by a reduction of hospitalization rates or mean occupancy time of hospitalized patients during this first decade of implementation of the reform. PMID:27253902

  18. Decadal interactions between the western tropical Pacific and the North Atlantic Oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Kucharski, Fred; Molteni, Franco; Bracco, Annalisa [Abdus Salam International Centre for Theoretical Physics, Physics of Weather and Climate Section, Trieste (Italy)


    The relationship between interdecadal variations of tropical sea surface temperature (SST) in the last 120 years and circulation anomalies related to the North Atlantic Oscillation (NAO) is investigated in this study. Using an atmospheric general circulation model (AGCM), we confirm observational evidence that variations in the SST gradient in the western tropical Pacific are related to the NAO anomalies on decadal timescale, and may be contributing to the shift towards the positive NAO phase observed in the late 20th century. The role played by the Indian Ocean-NAO teleconnection, advocated in recent studies focused on the last 50 years, is also assessed in the context of the 120-year long record. It is suggested that a positive feedback between the Pacific SST and the hemispheric circulation pattern embedding the decadal NAO signal may act to enhance the internal variability of the coupled ocean-atmosphere system, and justify the stronger teleconnection found in observational data than in SST-forced AGCM experiments. (orig.)

  19. Strong Motion Earthquake Data Values of Digitized Strong-Motion Accelerograms, 1933-1994 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Strong Motion Earthquake Data Values of Digitized Strong-Motion Accelerograms is a database of over 15,000 digitized and processed accelerograph records from...

  20. Decadal variability in Gulf of Mexico sea surface temperatures since 1734 CE (United States)

    DeLong, K. L.; Maupin, C. R.; Flannery, J. A.; Quinn, T. M.; lin, K.; Shen, C.


    The Gulf of Mexico is a major source of moisture to North America and is a source region for the Gulf Stream, which transports ocean heat northward. Sea surface temperature (SST) variations on centennial to millennial time scales have been documented for this region using paleoceanographic proxies; however, records capable of resolving decadal to subannual variability are lacking. Here we present 274 years of monthly-resolved SST variations derived from records of strontium-to-calcium ratios (Sr/Ca) extracted from four Siderastrea siderea cores recovered from coral colonies within the Dry Tortugas National Park (24°42‧N, 82°48‧W) in the Gulf of Mexico. We find no significant difference in mean Sr/Ca among these cores and significant correlation between cores (r ≥ 0.90, p ≤ 0.05 for monthly). The cross-dated chronology, determined by counting annual bands and correlating Sr/Ca variations, agrees with four 230Th dates within ±2σ analytical precision. Calibration and verification of our multi-core coral Sr/Ca record with local temperature records reveals high agreement (Sr/Ca = -0.042 SST + 10.074, R2 = 0.96; σregression = 0.70°C, 1σ), similar to those reported for single cores from this location. We find winter SSTs tend to be more variable than summer SSTs (0.99 and 0.81°C, 1σ; respectively) with periodic intervals of 10 to 15 years with cooler summer temperatures. The average reconstructed SST during the Little Ice Age (LIA; 1734-1880 CE) is colder (-0.82°C) than that during the late twentieth century (1971-2000 CE). The amplitude of decadal-scale variability (1 to 2.5°C) in the LIA is larger compared to similar scale variability in the twentieth century. The secular trend and decadal-scale variability in our reconstruction is broadly similar to an ~ decadally-resolved (~12 years/sample) Mg/Ca record from planktic foraminifer in the northern Gulf of Mexico (Richey et al., 2007), thus further confirming the reconstructed patterns of temperature

  1. Change in Practice over Four Decades in the Management of Graves’ Disease in Scotland

    Directory of Open Access Journals (Sweden)

    D. M. Smith


    Full Text Available There is continuing debate on the optimal treatment for Grave’s thyrotoxicosis with a resultant variation in clinical practice. The present study aimed to ascertain changes in practice in the treatment of Grave’s thyrotoxicosis in Tayside, Scotland, over the past four decades. Methods. The “Scottish automated follow-up register” (SAFUR was queried to identify all patients treated for Grave’s thyrotoxicosis from 1968 to 2007 inclusive. Patients were divided into 4 groups (Groups A to D according to the decades. Demographic profile, treatment modalities, radioactive iodine (RAI dose, and recurrence rates were studied and outcomes were compared by χ2 test and ANOVA using SPSS v15.0. A p value of < 0.05 was considered significant. Results. Altogether, 3737 patients were diagnosed with Grave’s thyrotoxicosis over the 4 decades. Use of RAI has increased from 43.1% in Group A to 68% in Group D (p<0.001. The dose of RAI has increased (p<0.001 and there has been a reduction in recurrence rate with higher dose of RAI. Surgical intervention rates decreased from 55.3% to 12.3% (p<0.001 over time. Conclusions. Analysis of a large dataset of patients with Grave’s thyrotoxicosis suggests increasing use of RAI as the preferred first line of treatment. Furthermore, using a single higher dose of RAI and adoption of total thyroidectomy have decreased recurrence rates.

  2. The extended reciprocity: Strong belief outperforms persistence. (United States)

    Kurokawa, Shun


    The existence of cooperation is a mysterious phenomenon and demands explanation, and direct reciprocity is one key potential explanation for the evolution of cooperation. Direct reciprocity allows cooperation to evolve for cooperators who switch their behavior on the basis of information about the opponent's behavior. Here, relevant to direct reciprocity is information deficiency. When the opponent's last move is unknown, how should players behave? One possibility is to choose cooperation with some default probability without using any further information. In fact, our previous paper (Kurokawa, 2016a) examined this strategy. However, there might be beneficial information other than the opponent's last move. A subsequent study of ours (Kurokawa, 2017) examined the strategy which uses the own last move when the opponent's last move is unknown, and revealed that referring to the own move and trying to imitate it when information is absent is beneficial. Is there any other beneficial information else? How about strong belief (i.e., have infinite memory and believe that the opponent's behavior is unchanged)? Here, we examine the evolution of strategies with strong belief. Analyzing the repeated prisoner's dilemma game and using evolutionarily stable strategy (ESS) analysis against an invasion by unconditional defectors, we find the strategy with strong belief is more likely to evolve than the strategy which does not use information other than the opponent player's last move and more likely to evolve than the strategy which uses not only the opponent player's last move but also the own last move. Strong belief produces the extended reciprocity and facilitates the evolution of cooperation. Additionally, we consider the two strategies game between strategies with strong belief and any strategy, and we consider the four strategies game in which unconditional cooperators, unconditional defectors, pessimistic reciprocators with strong belief, and optimistic reciprocators with

  3. Deconstructing southern African (multi) decadal summer rainfall variability through synoptic convection regimes (United States)

    Pohl, Benjamin; Dieppois, Bastien; Crétat, Julien


    Austral summer rainfall in Southern Africa is highly variable in time and space. Seasonal rainfall amounts archived in long-term observational databases have recently been shown to exhibit significant periodicities at the interannual timescale (with a 2-8 year peak materializing mostly the regional effects of El Niño Southern Oscillation, ENSO), the quasi-decadal (8-13 years) and inter-decadal (15-28 years) timescales, interpretable as the signature of the Pacific Decadal Oscillation and Interdecadal Pacific Oscillation over the region. Here, we attempt to deconstruct these rainfall signals into a limited number of coherent synoptic convective regimes, obtained by applying a k-means clustering on daily Outgoing Longwave Radiation (OLR) derived from the 20th Century Reanalysis (20CR), on the period 1901-2010 and on the 56 ensemble members individually. Results show a time-increasing agreement between the ensemble members for capturing transient variability of large-scale atmospheric convection during the austral summer rainy season. Over the recent years, the results match well those obtained using satellite OLR measurements. The respective contribution of each regime to the three dominant timescales of rainfall variability has been assessed using multiple wavelet coherence analyses. The strong interannual teleconnections between the regional convective regimes and ENSO in the recent decades remain very robust throughout the 20th century. Synoptic convective regimes leading to wetter conditions in southern Africa are not systematically related to La Nina conditions. However, combinations of El Nino conditions at the interannual timescale with negative phases of the IPO and/or the PDO are likely to be associated with wetter conditions in southern Africa. At the quasi-decadal and inter-decadal timescales, analyses suggest a superposition of short-term anomalies associated with the various regimes and large-scale changes in convective activity. These interactions

  4. Sensitivity analysis of uranium solubility under strongly oxidizing conditions

    International Nuclear Information System (INIS)

    Liu, L.; Neretnieks, I.


    To evaluate the effect of geochemical conditions in the repository on the solubility of uranium under strongly oxidizing conditions, a mathematical model has been developed to determine the solubility, by utilizing a set of nonlinear algebraic equations to describe the chemical equilibria in the groundwater environment. The model takes into account the predominant precipitation-dissolution reactions, hydrolysis reactions and complexation reactions that may occur under strongly oxidizing conditions. The model also includes the solubility-limiting solids induced by the presence of carbonate, phosphate, silicate, calcium, and sodium in the groundwater. The thermodynamic equilibrium constants used in the solubility calculations are essentially taken from the NEA Thermochemical Data Base of Uranium, with some modification and some uranium minerals added, such as soddyite, rutherfordite, uranophane, uranyl orthophosphate, and becquerelite. By applying this model, the sensitivities of uranium solubility to variations in the concentrations of various groundwater component species are systematically investigated. The results show that the total analytical concentrations of carbonate, phosphate, silicate, and calcium in deep groundwater play the most important role in determining the solubility of uranium under strongly oxidizing conditions

  5. Geomagnetic Core Field Secular Variation Models

    DEFF Research Database (Denmark)

    Gillet, N.; Lesur, V.; Olsen, Nils


    We analyse models describing time changes of the Earth’s core magnetic field (secular variation) covering the historical period (several centuries) and the more recent satellite era (previous decade), and we illustrate how both the information contained in the data and the a priori information...... (regularisation) affect the result of the ill-posed geomagnetic inverse problem. We show how data quality, frequency and selection procedures govern part of the temporal changes in the secular variation norms and spectra, which are sometimes difficult to dissociate from true changes of the core state. We...... highlight the difficulty of resolving the time variability of the high degree secular variation coefficients (i.e. the secular acceleration), arising for instance from the challenge to properly separate sources of internal and of external origin. In addition, the regularisation process may also result...

  6. Relativistic generalization of strong plasma turbulence

    International Nuclear Information System (INIS)

    Chian, A.C.-L.


    Two fundamental electrostatic modes of an unmagnetized plasma, namely, ion acoustic mode and Langumir mode are studied. Previous theories are generalized to include the effect of relativistic mass variations. The existence of relativistic ion acoustic solitons is demonstrated. In addition, it is shown that simple, relativistic Langumir solitons do not exist in a infinite plasma. (L.C.) [pt

  7. Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data. (United States)

    Scanlon, Bridget R; Zhang, Zizhan; Save, Himanshu; Sun, Alexander Y; Müller Schmied, Hannes; van Beek, Ludovicus P H; Wiese, David N; Wada, Yoshihide; Long, Di; Reedy, Robert C; Longuevergne, Laurent; Döll, Petra; Bierkens, Marc F P


    Assessing reliability of global models is critical because of increasing reliance on these models to address past and projected future climate and human stresses on global water resources. Here, we evaluate model reliability based on a comprehensive comparison of decadal trends (2002-2014) in land water storage from seven global models (WGHM, PCR-GLOBWB, GLDAS NOAH, MOSAIC, VIC, CLM, and CLSM) to trends from three Gravity Recovery and Climate Experiment (GRACE) satellite solutions in 186 river basins (∼60% of global land area). Medians of modeled basin water storage trends greatly underestimate GRACE-derived large decreasing (≤-0.5 km 3 /y) and increasing (≥0.5 km 3 /y) trends. Decreasing trends from GRACE are mostly related to human use (irrigation) and climate variations, whereas increasing trends reflect climate variations. For example, in the Amazon, GRACE estimates a large increasing trend of ∼43 km 3 /y, whereas most models estimate decreasing trends (-71 to 11 km 3 /y). Land water storage trends, summed over all basins, are positive for GRACE (∼71-82 km 3 /y) but negative for models (-450 to -12 km 3 /y), contributing opposing trends to global mean sea level change. Impacts of climate forcing on decadal land water storage trends exceed those of modeled human intervention by about a factor of 2. The model-GRACE comparison highlights potential areas of future model development, particularly simulated water storage. The inability of models to capture large decadal water storage trends based on GRACE indicates that model projections of climate and human-induced water storage changes may be underestimated. Copyright © 2018 the Author(s). Published by PNAS.

  8. Intra- to multi-decadal terrestrial precipitation regimes at the end of the 20th century

    Energy Technology Data Exchange (ETDEWEB)

    Mauget, S.A. [US Department of Agriculture-Agricultural Research Service, USDA Plant Stress and Water Conservation Laboratory, Lubbock, Texas, 3810 4th Street, Lubbock, TX 79415 (United States)


    Intra- to multi-decadal (IMD) variation in terrestrial precipitation during 1901-98 was evaluated here by sampling annual precipitation rankings over 6-30 year moving time windows and converting those rankings to Mann-Whitney U statistics. Those U statistics were then used to identify the most significant concentrations of wet and dry years relative to a null hypothesis that assumes stationary climate variability. This time series analysis approach served as the basis of a climate survey method used to identify IMD precipitation regimes over continental areas, and was also used to evaluate IMD variation in time series of annual precipitation spatially averaged over those areas. These methods showed a highly significant incidence of wet years over North America during 1972-98, with 8 of the 10 wettest years of 1901-98 occurring during that 27-year period. A comparably significant incidence of late century wetness was also found over a northern Europe grid region, with 7 of the 10 wettest years occurring during 1978-98. Although significant wet and dry regimes were also found over other land areas in the last decades of the 20th century, the late century North American and northern European wet periods stood out as the most statistically significant found here during 1901-98. It is suggested that these recent wet periods are actually terrestrial evidence of a single multi-decadal precipitation mode extending across the North Atlantic, and the most observable evidence of an even broader pattern of recent North Atlantic climate change.

  9. Multi-Decadal Oscillations of the Ocean Active Upper-Layer Heat Content (United States)

    Byshev, Vladimir I.; Neiman, Victor G.; Anisimov, Mikhail V.; Gusev, Anatoly V.; Serykh, Ilya V.; Sidorova, Alexandra N.; Figurkin, Alexander L.; Anisimov, Ivan M.


    Spatial patterns in multi-decadal variability in upper ocean heat content for the last 60 years are examined using a numerical model developed at the Institute of Numerical Mathematics of Russia (INM Model) and sea water temperature-salinity data from the World Ocean Database (in: Levitus, NOAA Atlas NESDIS 66, U.S. Wash.: Gov. Printing Office, 2009). Both the model and the observational data show that the heat content of the Active Upper Layer (AUL) in particular regions of the Atlantic, Pacific and Southern oceans have experienced prominent simultaneous variations on multi-decadal (25-35 years) time scales. These variations are compared earlier revealed climatic alternations in the Northern Atlantic region during the last century (Byshev et al. in Doklady Earth Sci 438(2):887-892, 2011). We found that from the middle of 1970s to the end of 1990s the AUL heat content decreased in several oceanic regions, while the mean surface temperature increased on Northern Hemisphere continents according to IPCC (in: Stocker et al. Contribution of working group I to the fifth assessment report of the intergovernmental panel on climate change, Cambridge University Press, Cambridge, 2013). This means that the climate-forcing effect of the ocean-atmosphere interaction in certain energy-active areas determines not only local climatic processes, but also have an influence on global-scale climate phenomena. Here we show that specific regional features of the AUL thermal structure are in a good agreement with climatic conditions on the adjacent continents. Further, the ocean AUL in the five distinctive regions identified in our study have resumed warming in the first decade of this century. By analogy inference from previous climate scenarios, this may signal the onset of more continental climate over mainlands.

  10. Regional influence of decadal to multidecadal Atlantic Oscillations in Morocco during the last 1200 years (United States)

    Ait Brahim, Y.; Sifeddine, A.; Cheng, H.; Khodri, M.; Cruz, F. W., Sr.; Pérez-Zanón, N.; SHA, L.; Wassenburg, J. A.; Bouchaou, L.


    Climate projections predict a substantial increase of extreme heats and drought occurrences during the coming decades in Morocco, while already under severe water stress. 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. However, the climate processes are still poorly understood in North Africa, which makes the investigation of hydroclimate variations during the last millennium in Morocco highly requested. Here, we present the first well-dated high resolution ( 1.7 years) stable oxygen isotope (δ18O) speleothem record from southwestern Morocco, covering the last 1200 years. Our record reveals substantial decadal to multidecadal swings between dry and humid periods, consistent with regional paleorecords, with prevailing dry conditions during the Medieval Climate Anomaly (MCA), wetter conditions during the Little Ice Age (LIA), and a trend towards dry conditions during the current warm period. These coherent regional climate signals suggest common climate controls. Statistical analyses indicate 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 millennium. Interestingly, the generally warmer MCA and colder LIA at longer multidecadal timescales probably influenced the regional climate in North Africa through the influence on Sahara Low which weakened and strengthened the mean moisture inflow from the Atlantic Ocean during the MCA and LIA respectively.

  11. Supporting aboriginal knowledge and practice in health care: lessons from a qualitative evaluation of the strong women, strong babies, strong culture program. (United States)

    Lowell, Anne; Kildea, Sue; Liddle, Marlene; Cox, Barbara; Paterson, Barbara


    The Strong Women, Strong Babies, Strong Culture Program (the Program) evolved from a recognition of the value of Aboriginal knowledge and practice in promoting maternal and child health (MCH) in remote communities of the Northern Territory (NT) of Australia. Commencing in 1993 it continues to operate today. In 2008, the NT Department of Health commissioned an evaluation to identify enabling factors and barriers to successful implementation of the Program, and to identify potential pathways for future development. In this paper we focus on the evaluation findings related specifically to the role of Aborignal cultural knowledge and practice within the Program. A qualitative evaluation utilised purposive sampling to maximise diversity in program history and Aboriginal culture. Semi-structured, in-depth interviews with 76 participants were recorded in their preferred language with a registered Interpreter when required. Thematic analysis of data was verified or modified through further discussions with participants and members of the evaluation team. Although the importance of Aboriginal knowledge and practice as a fundamental component of the Program is widely acknowledged, there has been considerable variation across time and location in the extent to which these cultural dimensions have been included in practice. Factors contributing to this variation are complex and relate to a number of broad themes including: location of control over Program activities; recognition and respect for Aboriginal knowledge and practice as a legitimate component of health care; working in partnership; communication within and beyond the Program; access to transport and working space; and governance and organisational support. We suggest that inclusion of Aboriginal knowledge and practice as a fundamental component of the Program is key to its survival over more than twenty years despite serious challenges. Respect for the legitimacy of Aboriginal knowledge and practice within health

  12. Intermediate-term variations in 200 years seismicity of south of Iran

    Directory of Open Access Journals (Sweden)

    Majid Nemati


    Full Text Available Remarkable variations in moderate–large seismicity during the last two centuries in Zagros and eastern Iran seismotectonic provinces have chronically been investigated, in this study. The time variations of seismic hazards [macroseismic maximum intensity and scalar moment of the earthquakes (I0 > IV; M > 5.0] were investigated as seismic behaviours for the study area. According to the fact that damage of an earthquake is strongly influenced by the depth of the event, depths of some of the historical and pre-instrumental earthquakes were reasonably estimated using macroseismic data. Processing the data of earthquakes reliably demonstrated that relatively quiet periods have happened and have subsequently been followed by active periods with various durations in south of Iran. According to both patterns of the temporal variations of seismicity and the seismic hazards, we are within a decelerating seismic deformation and we may expect an accelerating seismic deformation in the next decades. Moreover, in both areas, we discovered a manifest migration of the seismicity from the northeast to the southwest region that is a significant phenomenon in seismology. Finally, two seismic gaps at specific time periods in northwest of Zagros, Dasht-e Bayaz and Ferdows areas at the eastern Iran were also found.

  13. A strongly coupled quark-gluon plasma

    Energy Technology Data Exchange (ETDEWEB)

    Shuryak, Edward [Department of Physics and Astronomy, University at Stony Brook, NY 11794 (United States)


    Successful description of robust collective flow phenomena at RHIC by ideal hydrodynamics, recent observations of bound c-barc,q-barq states on the lattice, and other theoretical developments indicate that QGP produced at RHIC, and probably in a wider temperature region T{sub c} < T < 4T{sub c}, is not a weakly coupled quasiparticle gas as believed previously. We discuss how strong the interaction is and why it seems to generate hundreds of binary channels with bound states, surviving well inside the QGP phase. We in particular discuss their effect on pressure and viscosity. We conclude by reviewing the similar phenomena for other 'strongly coupled systems', such as (i) strongly coupled supersymmetric theories studied via Maldacena duality; (ii) trapped ultra-cold atoms with very large scattering length, tuned to Feschbach resonances.

  14. Strong Coupling between Plasmons and Organic Semiconductors

    Directory of Open Access Journals (Sweden)

    Joel Bellessa


    Full Text Available In this paper we describe the properties of organic material in strong coupling with plasmon, mainly based on our work in this field of research. The strong coupling modifies the optical transitions of the structure, and occurs when the interaction between molecules and plasmon prevails on the damping of the system. We describe the dispersion relation of different plasmonic systems, delocalized and localized plasmon, coupled to aggregated dyes and the typical properties of these systems in strong coupling. The modification of the dye emission is also studied. In the second part, the effect of the microscopic structure of the organics, which can be seen as a disordered film, is described. As the different molecules couple to the same plasmon mode, an extended coherent state on several microns is observed.

  15. A theory of the strong interactions

    International Nuclear Information System (INIS)

    Gross, D.J.


    The most promising candidate for a fundamental microscopic theory of the strong interactions is a gauge theory of colored quarks-Quantum Chromodynamics (QCD). There are many excellent reasons for believing in this theory. It embodies the broken symmetries, SU(3) and chiral SU(3)xSU(3), of the strong interactions and reflects the success of (albeit crude) quark models in explaining the spectrum of the observed hadrons. The hidden quantum number of color, necessary to account for the quantum numbers of the low lying hadrons, plays a fundamental role in this theory as the SU(3) color gauge vector 'gluons' are the mediators of the strong interactions. The absence of physical quark states can be 'explained' by the hypothesis of color confinement i.e. that hadrons are permanently bound in color singlet bound states. Finally this theory is unique in being asymptotically free, thus accounting for the almost free field theory behvior of quarks observed at short distances. (Auth.)

  16. Electromagnetic processes in strong crystalline fields

    CERN Multimedia


    We propose a number of new investigations on aspects of radiation from high energy electron and positron beams (10-300 GeV) in single crystals and amorphous targets. The common heading is radiation emission by electrons and positrons in strong electromagnetic fields, but as the setup is quite versatile, other related phenomena in radiation emission can be studied as well. The intent is to clarify the role of a number of important aspects of radiation in strong fields as e.g. observed in crystals. We propose to measure trident 'Klein-like' production in strong crystalline fields, 'crystalline undulator' radiation, 'sandwich' target phenomena, LPM suppression of pair production as well as axial and planar effects in contributions of spin to the radiation.

  17. Patterns of Strong Coupling for LHC Searches

    CERN Document Server

    Liu, Da; Rattazzi, Riccardo; Riva, Francesco


    Even though the Standard Model (SM) is weakly coupled at the Fermi scale, a new strong dynamics involving its degrees of freedom may conceivably lurk at slightly higher energies, in the multi TeV range. Approximate symmetries provide a structurally robust context where, within the low energy description, the dimensionless SM couplings are weak, while the new strong dynamics manifests itself exclusively through higher-derivative interactions. We present an exhaustive classification of such scenarios in the form of effective field theories, paying special attention to new classes of models where the strong dynamics involves, along with the Higgs boson, the SM gauge bosons and/or the fermions. The IR softness of the new dynamics suppresses its effects at LEP energies, but deviations are in principle detectable at the LHC, even at energies below the threshold for production of new states. Our construction provides the so far unique structurally robust context where to motivate several searches in Higgs physics, d...

  18. Electronic Structure of Strongly Correlated Materials

    CERN Document Server

    Anisimov, Vladimir


    Electronic structure and physical properties of strongly correlated materials containing elements with partially filled 3d, 4d, 4f and 5f electronic shells is analyzed by Dynamical Mean-Field Theory (DMFT). DMFT is the most universal and effective tool used for the theoretical investigation of electronic states with strong correlation effects. In the present book the basics of the method are given and its application to various material classes is shown. The book is aimed at a broad readership: theoretical physicists and experimentalists studying strongly correlated systems. It also serves as a handbook for students and all those who want to be acquainted with fast developing filed of condensed matter physics.

  19. Electromagnetic Processes in strong Crystalline Fields

    CERN Multimedia


    We propose a number of new investigations on aspects of radiation from high energy electron and positron beams (10-300 GeV) in single crystals and amorphous targets. The common heading is radiation emission by electrons and positrons in strong electromagnetic fields, but as the setup is quite versatile, other related phenomena in radiation emission can be studied as well. The intent is to clarify the role of a number of important aspects of radiation in strong fields as e.g. observed in crystals. We propose to measure trident 'Klein-like' production in strong crystalline fields, 'crystalline undulator' radiation, 'sandwich' target phenomena, LPM suppression of pair production as well as axial and planar effects in contributions of spin to the radiation.

  20. Ventilation coefficient trends in the recent decades over four major ...

    Indian Academy of Sciences (India)

    Thirty years radiosonde data (1971–2000) at 00 UTC for winter months over four major Indian metros, viz., Mumbai, Delhi, Kolkata and Chennai is analysed to study the trends and long term variations in ventilation coefficients and the consequences on the air quality due to these variations in the four metros. A decreasing ...

  1. Persistent decadal-scale rainfall variability in the tropical South Pacific Convergence Zone through the past six centuries


    Maupin, C. R.; Partin, J. W.; Shen, C.-C.; Quinn, T. M.; Lin, K.; Taylor, F. W.; Banner, J. L.; Thirumalai, K.; Sinclair, D. J.


    Modern Pacific decadal variability (PDV) has global impacts; hence records of PDV from the pre-instrumental period are needed to better inform models that are used to project future climate variability. We focus here on reconstructing rainfall in the western tropical Pacific (Solomon Islands; ~ 9.5° S, ~160° E), a region directly influenced by PDV, using cave deposits (stalagmite). A relationship is developed between δ18O variations in the stalagmite and local rainfall am...

  2. Investigating the effect of lateral viscosity variations in the Earth's mantle (United States)

    O'Farrell, K. A.; Lithgow-Bertelloni, C. R.


    Seismic tomography can be used to investigate radial viscosity variations on instantaneous flow models by predicting the global geoid and comparing with the observed geoid. This method is one of many that has been used to constrain viscosity structure in the Earth's mantle in the last few decades. Using the 3D mantle convection model, Stag-YY (e.g., Hernlund and Tackley, 2008), we are further able to explore the effect of lateral variations in viscosity in addition to the radial variations. Examining over 50 tomographic models we found notable differences by comparing a synthetically produced geoid with the observed geoid. Comparing S- and P-wave tomographic models, the S-wave models provided a better fit to the observed geoid. Using this large suite of 50 tomographic models, we have been able to constrain the radial viscosity structure of the Earth. We found that two types of viscosity profiles yielded equally good fits. A viscosity profile with a low transition zone viscosity and a lower mantle viscosity equal to the upper mantle, or a profile with a large lower mantle viscosity and a transition zone viscosity similar to the upper mantle. Using the set of radial viscosity profiles that gave the best fit to the observed geoid, we can explore a range of lateral viscosity variations and see how they affect the different types of tomographic models. Improving on previous studies of lateral viscosity variations (e.g. Ghosh, Becker and Zhong, 2010), we systematically explore a large range of tomographic models and density-velocity conversion factors. We explore which type of tomographic model (S- or P- wave) is more strongly affected by lateral viscosity variations, as well as the effect on isotropic and anisotropic models. We constrain the strength of lateral viscosity variations necessary to produce a high correlation between observed and predicted geoid anomalies. We will discuss the wavelength of flow that is most affected by the lateral viscosity variations

  3. Trends in upper gastrointestinal diagnosis over four decades in Lusaka, Zambia: a retrospective analysis of endoscopic findings. (United States)

    Kayamba, Violet; Sinkala, Edford; Mwanamakondo, Stayner; Soko, Rose; Kawimbe, Boniface; Amadi, Beatrice; Zulu, Isaac; Nzaisenga, Jean-Baptiste; Banda, Themba; Mumbwe, Chipasha; Phiri, Evans; Munkonge, Philip; Kelly, Paul


    There a shortage of robust information about profiles of gastrointestinal disease in sub-Saharan Africa. The endoscopy unit of the University Teaching Hospital in Lusaka has been running without interruption since 1977 and this 38-year record is largely intact. We report an analysis of endoscopic findings over this period. Written endoscopy records from 29th September 1977 to 16th December 2014 were recovered, computerised, coded by two experienced endoscopists and analysed. Temporal trends were analysed using tables, graphs, and unconditional logistic regression, with age, sex of patient, decade, and endoscopist as independent variables to adjust for inter-observer variation. Sixteen thousand nine hundred fifty-three records were identified and analysed. Diagnosis of gastric ulcer rose by 22 %, and that of duodenal ulcer fell by 14 % per decade. Endoscopically diagnosed oesophageal cancer increased by 32 % per decade, but gastric cancer rose only in patients under 60 years of age (21 % per decade). Oesophageal varices were the commonest finding in patients presenting with haematemesis, increasing by 14 % per decade in that patient group. Two HIV-related diagnoses, oesophageal candidiasis and Kaposi's sarcoma, rose from almost zero to very high levels in the 1990s but fell substantially after 2005 when anti-retroviral therapy became widely available. This useful dataset suggests that there are important trends in some endoscopic findings over four decades. These trends are not explained by inter-observer variation. Reasons for the divergent trends in incidence of peptic ulceration and apparent trends in diagnosis of upper gastrointestinal cancers merit further exploration.

  4. Experimental investigation of strong field trident production

    CERN Document Server

    Esberg, J; Knudsen, H; Thomsen, H D; Uggerhøj, E; Uggerhøj, U I; Sona, P; Mangiarotti, A; Ketel, T J; Dizdar, A; Dalton, M M; Ballestrero, S; Connell, S H


    We show by experiment that an electron impinging on an electric field that is of critical magnitude in its rest frame, may produce an electron-positron pair. Our measurements address higher-order QED, using the strong electric fields obtainable along particular crystallographic directions in single crystals. For the amorphous material our data are in good agreement with theory, whereas a discrepancy with theory on the magnitude of the trident enhancement is found in the precisely aligned case where the strong electric field acts.

  5. Gluon scattering amplitudes at strong coupling

    Energy Technology Data Exchange (ETDEWEB)

    Alday, Luis F. [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD Utrecht (Netherlands); Maldacena, Juan [School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540 (United States)


    We describe how to compute planar gluon scattering amplitudes at strong coupling in N = 4 super Yang Mills by using the gauge/string duality. The computation boils down to finding a certain classical string configuration whose boundary conditions are determined by the gluon momenta. The results are infrared divergent. We introduce the gravity version of dimensional regularization to define finite quantities. The leading and subleading IR divergencies are characterized by two functions of the coupling that we compute at strong coupling. We compute also the full finite form for the four point amplitude and we find agreement with a recent ansatz by Bern, Dixon and Smirnov.

  6. Strong boundedness of analytic functions in tubes

    Directory of Open Access Journals (Sweden)

    Richard D. Carmichael


    Full Text Available Certain classes of analytic functions in tube domains TC=ℝn+iC in n-dimensional complex space, where C is an open connected cone in ℝn, are studied. We show that the functions have a boundedness property in the strong topology of the space of tempered distributions g′. We further give a direct proof that each analytic function attains the Fourier transform of its spectral function as distributional boundary value in the strong (and weak topology of g′.

  7. Including virtual photons in strong interactions

    International Nuclear Information System (INIS)

    Rusetsky, A.


    In the perturbative field-theoretical models we investigate the inclusion of the electromagnetic interactions into the purely strong theory that describes hadronic processes. In particular, we study the convention for splitting electromagnetic and strong interactions and the ambiguity of such a splitting. The issue of the interpretation of the parameters of the low-energy effective field theory in the presence of electromagnetic interactions is addressed, as well as the scale and gauge dependence of the effective theory couplings. We hope, that the results of these studies are relevant for the electromagnetic sector of ChPT. (orig.)

  8. Thermodynamical instabilities under strong magnetic fields (United States)

    Chen, Y. J.


    The thermodynamical instabilities of low densities in the n p matter and n p e matter are studied within several relativistic nuclear models under some values of magnetic fields. The results are compared between each other and the effects of the symmetry energy slope at saturation density on the instability are investigated. The instability regions can exhibit bands due to the presence of Landau levels for very strong magnetic fields of the order of 1017 G, while for weaker magnetic fields, the bands are replaced by many diffused or scattered pieces. It also shows that the proton fraction in the inner crust of neutron stars may be complex under strong magnetic fields.

  9. Universal behavior of strongly correlated Fermi systems

    Energy Technology Data Exchange (ETDEWEB)

    Shaginyan, Vasilii R [B.P. Konstantinov St. Petersburg Institute of Nuclear Physics, Russian Academy of Sciences, Gatchina, Leningrad region, Rusian Federation (Russian Federation); Amusia, M Ya [A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg (Russian Federation); Popov, Konstantin G [Komi Scientific Center, Ural Branch of the Russian Academy of Sciences, Syktyvkar (Russian Federation)


    This review discusses the construction of a theory and the analysis of phenomena occurring in strongly correlated Fermi systems such as high-T{sub c} superconductors, heavy-fermion metals, and quasi-two-dimensional Fermi systems. It is shown that the basic properties and the universal behavior of strongly correlated Fermi systems can be described in the framework of the Fermi-condensate quantum phase transition and the well-known Landau paradigm of quasiparticles and the order parameter. The concept of fermion condensation may be fruitful in studying neutron stars, finite Fermi systems, ultra-cold gases in traps, and quark plasma. (reviews of topical problems)

  10. Universal behavior of strongly correlated Fermi systems

    International Nuclear Information System (INIS)

    Shaginyan, Vasilii R; Amusia, M Ya; Popov, Konstantin G


    This review discusses the construction of a theory and the analysis of phenomena occurring in strongly correlated Fermi systems such as high-T c superconductors, heavy-fermion metals, and quasi-two-dimensional Fermi systems. It is shown that the basic properties and the universal behavior of strongly correlated Fermi systems can be described in the framework of the Fermi-condensate quantum phase transition and the well-known Landau paradigm of quasiparticles and the order parameter. The concept of fermion condensation may be fruitful in studying neutron stars, finite Fermi systems, ultra-cold gases in traps, and quark plasma. (reviews of topical problems)

  11. Analytical solution of strongly nonlinear Duffing oscillators


    El-Naggar, A.M.; Ismail, G.M.


    In this paper, a new perturbation technique is employed to solve strongly nonlinear Duffing oscillators, in which a new parameter α=α(ε)α=α(ε) is defined such that the value of α is always small regardless of the magnitude of the original parameter εε. Therefore, the strongly nonlinear Duffing oscillators with large parameter ε are transformed into a small parameter system with respect to αα. Approximate solution obtained by the present method is compared with the solution of energy balance m...

  12. De Sitter vacua of strongly interacting QFT

    Energy Technology Data Exchange (ETDEWEB)

    Buchel, Alex [Department of Applied Mathematics, University of Western Ontario,London, Ontario N6A 5B7 (Canada); Department of Physics and Astronomy, University of Western Ontario,London, Ontario N6A 5B7 (Canada); Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2J 2W9 (Canada); Karapetyan, Aleksandr [Department of Applied Mathematics, University of Western Ontario,London, Ontario N6A 5B7 (Canada)


    We use holographic correspondence to argue that Euclidean (Bunch-Davies) vacuum is a late-time attractor of the dynamical evolution of quantum gauge theories at strong coupling. The Bunch-Davies vacuum is not an adiabatic state, if the gauge theory is non-conformal — the comoving entropy production rate is nonzero. Using the N=2{sup ∗} gauge theory holography, we explore prospects of explaining current accelerated expansion of the Universe as due to the vacuum energy of a strongly coupled QFT.

  13. Ocean impact on decadal Atlantic climate variability revealed by sea-level observations. (United States)

    McCarthy, Gerard D; Haigh, Ivan D; Hirschi, Joël J-M; Grist, Jeremy P; Smeed, David A


    Decadal variability is a notable feature of the Atlantic Ocean and the climate of the regions it influences. Prominently, this is manifested in the Atlantic Multidecadal Oscillation (AMO) in sea surface temperatures. Positive (negative) phases of the AMO coincide with warmer (colder) North Atlantic sea surface temperatures. The AMO is linked with decadal climate fluctuations, such as Indian and Sahel rainfall, European summer precipitation, Atlantic hurricanes and variations in global temperatures. It is widely believed that ocean circulation drives the phase changes of the AMO by controlling ocean heat content. However, there are no direct observations of ocean circulation of sufficient length to support this, leading to questions about whether the AMO is controlled from another source. Here we provide observational evidence of the widely hypothesized link between ocean circulation and the AMO. We take a new approach, using sea level along the east coast of the United States to estimate ocean circulation on decadal timescales. We show that ocean circulation responds to the first mode of Atlantic atmospheric forcing, the North Atlantic Oscillation, through circulation changes between the subtropical and subpolar gyres--the intergyre region. These circulation changes affect the decadal evolution of North Atlantic heat content and, consequently, the phases of the AMO. The Atlantic overturning circulation is declining and the AMO is moving to a negative phase. This may offer a brief respite from the persistent rise of global temperatures, but in the coupled system we describe, there are compensating effects. In this case, the negative AMO is associated with a continued acceleration of sea-level rise along the northeast coast of the United States.

  14. Decadal Variability of Total Alkalinity in the North Pacific Ocean (United States)

    Cross, J. N.; Carter, B. R.; Siedlecki, S. A.; Alin, S. R.; Dickson, A. G.; Feely, R. A.; Mathis, J. T.; Wanninkhof, R. H.; Macdonald, A. M.; Mecking, S.; Talley, L. D.


    Recent observations of acidification-driven shoaling of the calcium carbonate saturation horizon in the North Pacific have prompted new interest in carbonate cycling in this region, particularly related to impacts on biogenic calcification at the surface layer. Some estimates project that the impacts of OA on alkalinity cycling are beginning to emerge. Here, we present total alkalinity concentrations along a meridional transect of the North Pacific (WOCE, CLIVAR, and US GO-SHIP line P16N; 152 °W) over a period of three decades. The largest source of variability in alkalinity concentrations is related to North Pacific circulation, particularly in the surface mixed layer. Precise normalization of these data reveal some small spatial and temporal variability in the background. We explore these decadal trends in the context of decadal oscillations, ocean biogeochemical cycles, and global change processes such as ocean acidification.

  15. Space strategy for Europe and the International Lunar Decade (United States)

    Beldavs, VZ


    The 2020-2030 decade offers extraordinary opportunity for the European space sector that is largely not recognized in present space strategy which does not recognize commercial space activities beyond communications satellites, launchers, and earth observation and navigation and downstream activities. Lunar and cislunar development can draw on the extensive experience of Europe in mining, clean energy, ecological systems as well as deep experience in managing the development of technologies through TRL1 through commercial sale via Horizon 2020 and previous Framework programs. The EU has unrivalled experience in coordinating research and advanced technology development from research centers, major firms and SMEs across multiple sovereign states. This capacity to coordinate across national boundaries can be a significant contribution to a global cooperative program like the International Lunar Decade. This paper will present a European space strategy for beyond 2020 and how this can mesh with the International Lunar Decade.

  16. A sub-decadal trend in diacids in atmospheric aerosols in eastern Asia (United States)

    Kundu, S.; Kawamura, K.; Kobayashi, M.; Tachibana, E.; Lee, M.; Fu, P. Q.; Jung, J.


    Change in secondary organic aerosols (SOAs) has been predicted to be highly uncertain in the future atmosphere in Asia. To better quantify the SOA change, we examine the sub-decadal (2001-2008) trend in major surrogate compounds (C2-C10 diacids) of SOA in atmospheric aerosols from Gosan site on Cheju Island, South Korea. The Gosan site is influenced by pollution outflows from eastern Asia. The molecular distributions of diacids were characterized by the predominance of oxalic (C2) acid followed by malonic (C3) and succinic (C4) acids in each year. The seasonal variations in diacids in each year were characterized by the highest concentrations of saturated diacids in spring and unsaturated diacids in winter. The consistent molecular distributions and seasonal variations along with significantly similar air mass transport patterns are indicative of similar pollution sources for diacids in eastern Asia on a sub-decadal scale. However, the intensity of the pollution sources has increased as evidenced by the increases in major diacids at the rate of 3.9-47.4 % per year, particularly in April. The temporal variations in atmospheric tracer compounds (carbon monoxide, levoglucosan, 2-methyltetrols, pinic acid, glyoxylic acid, glyoxal and methylglyoxal) suggest that the increases in diacids are due to enhanced precursor emissions associated with more anthropogenic than biogenic activities followed by the compounds' chemical processing in the atmosphere. The trends in diacids contrast with the reported decreases in sulfate, nitrate and ammonium in recent years in eastern Asia. This study demonstrates that recent pollution control strategies in eastern Asia were not able to decrease organic acidic species in the atmosphere. The increases in water-soluble organic acid fraction could modify the aerosol organic composition and its sensitivity to climate relevant physical properties.

  17. A sub-decadal trend in diacids in atmospheric aerosols in eastern Asia

    Directory of Open Access Journals (Sweden)

    S. Kundu


    Full Text Available Change in secondary organic aerosols (SOAs has been predicted to be highly uncertain in the future atmosphere in Asia. To better quantify the SOA change, we examine the sub-decadal (2001–2008 trend in major surrogate compounds (C2–C10 diacids of SOA in atmospheric aerosols from Gosan site on Cheju Island, South Korea. The Gosan site is influenced by pollution outflows from eastern Asia. The molecular distributions of diacids were characterized by the predominance of oxalic (C2 acid followed by malonic (C3 and succinic (C4 acids in each year. The seasonal variations in diacids in each year were characterized by the highest concentrations of saturated diacids in spring and unsaturated diacids in winter. The consistent molecular distributions and seasonal variations along with significantly similar air mass transport patterns are indicative of similar pollution sources for diacids in eastern Asia on a sub-decadal scale. However, the intensity of the pollution sources has increased as evidenced by the increases in major diacids at the rate of 3.9–47.4 % per year, particularly in April. The temporal variations in atmospheric tracer compounds (carbon monoxide, levoglucosan, 2-methyltetrols, pinic acid, glyoxylic acid, glyoxal and methylglyoxal suggest that the increases in diacids are due to enhanced precursor emissions associated with more anthropogenic than biogenic activities followed by the compounds' chemical processing in the atmosphere. The trends in diacids contrast with the reported decreases in sulfate, nitrate and ammonium in recent years in eastern Asia. This study demonstrates that recent pollution control strategies in eastern Asia were not able to decrease organic acidic species in the atmosphere. The increases in water-soluble organic acid fraction could modify the aerosol organic composition and its sensitivity to climate relevant physical properties.

  18. Decadal Polar Motion of the Earth Excited by the Convective Outer Core From Geodynamo Simulations (United States)

    Kuang, W.; Chao, B. F.; Chen, J.


    Long time geodetic observation records show that the orientation of the Earth's rotation axis with respect to the terrestrial reference frame, or polar motion, changes on a broad range of timescales. Apart from external torques from the luni-solar tides, these changes are excited by interactions among different components of the Earth system. The convective fluid outer core has long been conjectured a likely contributor to the observed polar motion on timescales upward of decades, such as the ˜30 year Markowitz wobble. We investigated the electromagnetic coupling scenario across the core-mantle boundary via numerical geodynamo simulation for different geodynamo parameters (Rayleigh numbers and magnetic Rossby numbers). Our simulated polar motion varies strongly with the dynamo parameters, while its excitation on decadal timescales appear to converge asymptotically within the adopted range of numerical Rossby numbers. Three strongest asymptotic modes emerge from numerical results, with periods around 30, 40, and 60 years for the prograde excitation and around 24, 30, and 60 years for the retrograde excitation. Their amplitudes are all larger than 5 × 10-8, or approximately 10 milliseconds of arc. The results suggest that the electromagnetic core-mantle coupling could explain a substantial portion, if not all, of the observed decadal polar motion. In particular, the predicted 60 year polar motion deserves special attention for future observations and studies.

  19. Strong biotic influences on regional patterns of climate regulation services (United States)

    Serna-Chavez, H. M.; Swenson, N. G.; Weiser, M. D.; van Loon, E. E.; Bouten, W.; Davidson, M. D.; van Bodegom, P. M.


    Climate regulation services from forests are an important leverage in global-change mitigation treaties. Like most ecosystem services, climate regulation is the product of various ecological phenomena with unique spatial features. Elucidating which abiotic and biotic factors relate to spatial patterns of climate regulation services advances our understanding of what underlies climate-mitigation potential and its variation within and across ecosystems. Here we quantify and contrast the statistical relations between climate regulation services (albedo and evapotranspiration, primary productivity, and soil carbon) and abiotic and biotic factors. We focus on 16,955 forest plots in a regional extent across the eastern United States. We find the statistical effects of forest litter and understory carbon on climate regulation services to be as strong as those of temperature-precipitation interactions. These biotic factors likely influence climate regulation through changes in vegetation and canopy density, radiance scattering, and decomposition rates. We also find a moderate relation between leaf nitrogen traits and primary productivity at this regional scale. The statistical relation between climate regulation and temperature-precipitation ranges, seasonality, and climatic thresholds highlights a strong feedback with global climate change. Our assessment suggests the expression of strong biotic influences on climate regulation services at a regional, temperate extent. Biotic homogenization and management practices manipulating forest structure and succession will likely strongly impact climate-mitigation potential. The identity, strength, and direction of primary influences differed for each process involved in climate regulation. Hence, different abiotic and biotic factors are needed to monitor and quantify the full climate-mitigation potential of temperate forest ecosystems.

  20. EGS4 in '94: A decade of enhancements

    International Nuclear Information System (INIS)

    Nelson, W.R.; Bielajew, A.F.; Rogers, D.W.O.


    This paper presents an overview of the developments made to the EGS4 code over the past decade. This code is a Monte Carlo code developed to study electron-photon transport properties. It is widely used, in particular in the medical physics field, it has been updated, expanded, benchmarked, and applied to a wide array of problems. The paper covers precursors to this code, a basic snapshop of its physics and calculation methods, and an overview of how it has been expanded during the past decade

  1. United States Foreign Policy Toward Australia in the Next Decade (United States)


    more industry, energy, housing , services, and just about everything. l"Consider Australia ," The Economist, 30 May 1964, p. 967. 16 The availability of...BENEFIT TO THE USER AS MAY ACCRUE. 8 April 1966 UNITED STATES FOREIGN POLICY TOWARD AUSTRALIA IN THE NEXT DECADE By 2) i:ob i . 1RMY WAR COLI.IGF LOUIS J...States Foreign Policy Toward Australia in the Next Decade by Lt Col Louis J. Schelter, Jr. Infantry US Army War College Carlisle Barracks

  2. Earthquake source model using strong motion displacement

    Indian Academy of Sciences (India)

    The strong motion displacement records available during an earthquake can be treated as the response of the earth as the a structural system to unknown forces acting at unknown locations. Thus, if the part of the earth participating in ground motion is modelled as a known finite elastic medium, one can attempt to model the ...

  3. Vector mesons in strongly interacting matter

    Indian Academy of Sciences (India)

    probes like photons, pions or protons or the heated and compressed hadronic matter generated in a heavy-ion collision. Leaving any nuclear medium without strong final-state interactions, dileptons are the optimum decay channel as they avoid any final-state distortion of the 4- momenta of the decay products entering eq.

  4. Vector mesons in strongly interacting matter

    Indian Academy of Sciences (India)

    Properties of hadrons in strongly interacting matter provide a link between quantum chromodynamics in the ... Top: Spectral function of the ρ-meson at normal nuclear matter density as a function of mass and ... directly but folded with the branching ratio ΓV →p1+p2 /Γtot into the specific final channel one is investigating.

  5. Strong industrial base vital for economic revival

    CERN Multimedia


    At the inauguration of a 2-day conference on nuclear technology in Islamabad, the chairman of PAEC said that Pakistan needs to develop a strong industrial base and capability to export equipment to improve the economic condition of the country. He descibed how Pakistan has already had a breakthrough with the export of equipment to CERN, Geneva (1 page).

  6. Chaos desynchronization in strongly coupled systems

    International Nuclear Information System (INIS)

    Wu Ye; Liu Weiqing; Xiao, Jinghua; Zhan Meng


    The dynamics of chaos desynchronization in strongly coupled oscillator systems is studied. We find a new bifurcation from synchronous chaotic state, chaotic short wave bifurcation, i.e. a chaotic desynchronization attractor is new born in the systems due to chaos desynchronization. In comparison with the usual periodic short wave bifurcation, very rich but distinct phenomena are observed

  7. Strong wind climatic zones in South Africa

    CSIR Research Space (South Africa)

    Kruger, AC


    Full Text Available In this paper South Africa is divided into strong wind climate zones, which indicate the main sources of annual maximum wind gusts. By the analysis of wind gust data of 94 weather stations, which had continuous climate time series of 10 years...

  8. Reducing Weak to Strong Bisimilarity in CCP

    Directory of Open Access Journals (Sweden)

    Andrés Aristizábal


    Full Text Available Concurrent constraint programming (ccp is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes evolve by posting and querying (partial information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence.

  9. Strong motion duration and earthquake magnitude relationships

    International Nuclear Information System (INIS)

    Salmon, M.W.; Short, S.A.; Kennedy, R.P.


    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ''strong motion duration'' has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions

  10. Morphological modelling of strongly curved islands

    NARCIS (Netherlands)

    Roelvink, D.; Den Heijer, C.; Van Thiel De Vries, J.S.M.


    Land reclamations and island coasts often involve strongly curved shorelines, which are challenging to be properly modeled by numerical morphological models. Evaluation of the long term development of these types of coasts as well as their response to storm conditions requires proper representation

  11. Nonlinear Electron Waves in Strongly Magnetized Plasmas

    DEFF Research Database (Denmark)

    Pécseli, Hans; Juul Rasmussen, Jens


    Weakly nonlinear dispersive electron waves in strongly magnetized plasma are considered. A modified nonlinear Schrodinger equation is derived taking into account the effect of particles resonating with the group velocity of the waves (nonlinear Landau damping). The possibility of including the ion...

  12. Strong and Reversible Monovalent Supramolecular Protein Immobilization

    NARCIS (Netherlands)

    Young, Jacqui F.; Nguyen, Hoang D.; Yang, Lanti; Huskens, Jurriaan; Jonkheijm, Pascal; Brunsveld, Luc


    Proteins with an iron clasp: Site-selective incorporation of a ferrocene molecule into a protein allows for easy, strong, and reversible supramolecular protein immobilization through a selective monovalent interaction of the ferrocene with a cucurbit[7]uril immobilized on a gold surface. The

  13. Experimental investigation of strong field trident production

    NARCIS (Netherlands)

    Esberg, J.; Kirsebom, K.; Knudsen, H.; Thomsen, H.D.; Uggerhøj, E.; Uggerhøj, U.I.; Sona, P.; Mangiarotti, A.; Ketel, T.J.; Ditzdar, A.; Dalton, M.M.; Ballestrero, S.; Connell, S.H.


    We show by experiment that an electron impinging on an electric field that is of critical magnitude in its rest frame, may produce an electron-positron pair. Our measurements address higher-order QED, using the strong electric fields obtainable along particular crystallographic directions in single

  14. Strong-coupling diffusion in relativistic systems

    Indian Academy of Sciences (India)

    hanced values needed to interpret the data at higher energies point towards the importance of strong-coupling effects. ... when all secondary particles have been created. For short times in the initial phase ... It is decisive for a proper representation of the available data for relativistic heavy-ion collisions at and beyond SPS.

  15. Bottomonia: open bottom strong decays and spectrum

    Directory of Open Access Journals (Sweden)

    Santopinto E.


    Full Text Available We present our results for the bottomonium spectrum with self energy corrections. The bare masses used in the calculation are computed within Godfrey and Isgur’s relativized quark model. We also discuss our results for the open bottom strong decay widths of higher bottomonia in the 3P0 pair-creation model.

  16. Strong motion duration and earthquake magnitude relationships

    Energy Technology Data Exchange (ETDEWEB)

    Salmon, M.W.; Short, S.A. [EQE International, Inc., San Francisco, CA (United States); Kennedy, R.P. [RPK Structural Mechanics Consulting, Yorba Linda, CA (United States)


    Earthquake duration is the total time of ground shaking from the arrival of seismic waves until the return to ambient conditions. Much of this time is at relatively low shaking levels which have little effect on seismic structural response and on earthquake damage potential. As a result, a parameter termed ``strong motion duration`` has been defined by a number of investigators to be used for the purpose of evaluating seismic response and assessing the potential for structural damage due to earthquakes. This report presents methods for determining strong motion duration and a time history envelope function appropriate for various evaluation purposes, for earthquake magnitude and distance, and for site soil properties. There are numerous definitions of strong motion duration. For most of these definitions, empirical studies have been completed which relate duration to earthquake magnitude and distance and to site soil properties. Each of these definitions recognizes that only the portion of an earthquake record which has sufficiently high acceleration amplitude, energy content, or some other parameters significantly affects seismic response. Studies have been performed which indicate that the portion of an earthquake record in which the power (average rate of energy input) is maximum correlates most closely with potential damage to stiff nuclear power plant structures. Hence, this report will concentrate on energy based strong motion duration definitions.

  17. Controlling Josephson dynamics by strong microwave fields

    NARCIS (Netherlands)

    Chesca, B.; Savel'ev, E.; Rakhmanov, A.L.; Smilde, H.J.H.; Hilgenkamp, Johannes W.M.


    We observe several sharp changes in the slope of the current-voltage characteristics (CVCs) of thin-film ramp-edge Josephson junctions between YBa2Cu3O7−delta and Nb when applying strong microwave fields. Such behavior indicates an intriguing Josephson dynamics associated with the switching from a

  18. Strong-coupling diffusion in relativistic systems

    Indian Academy of Sciences (India)

    Different from the early universe, heavy-ion collisions at very high energies do not reach statistical equilibrium, although thermal models explain many of their features. To account for nonequilibrium strong-coupling effects, a Fokker–Planck equation with time-dependent diffusion coefficient is proposed. A schematic model ...

  19. Weak and strong nonlinearities in magnetic bearings

    Czech Academy of Sciences Publication Activity Database

    Půst, Ladislav


    Roč. 39, č. 7 (2004), s. 779-795 ISSN 0094-114X R&D Projects: GA ČR GA101/00/1471; GA AV ČR IBS2076301 Institutional research plan: CEZ:AV0Z2076919 Keywords : weak nonlinearitiy * strong nonlinearity * magnetics bearings Subject RIV: BI - Acoustics Impact factor: 0.605, year: 2004

  20. Rotating compressible fluids under strong stratification

    Czech Academy of Sciences Publication Activity Database

    Feireisl, Eduard; Lu, Y.; Novotný, A.


    Roč. 19, October (2014), s. 11-18 ISSN 1468-1218 Keywords : rotating fluid * compressible Navier-Stokes * strong stratification Subject RIV: BA - General Mathematics Impact factor: 2.519, year: 2014

  1. Super-strong Magnetic Field in Sunspots (United States)

    Okamoto, Takenori J.; Sakurai, Takashi


    Sunspots are the most notable structure on the solar surface with strong magnetic fields. The field is generally strongest in a dark area (umbra), but sometimes stronger fields are found in non-dark regions, such as a penumbra and a light bridge. The formation mechanism of such strong fields outside umbrae is still puzzling. Here we report clear evidence of the magnetic field of 6250 G, which is the strongest field among Stokes I profiles with clear Zeeman splitting ever observed on the Sun. The field was almost parallel to the solar surface and located in a bright region sandwiched by two opposite-polarity umbrae. Using a time series of spectral data sets, we discuss the formation process of the super-strong field and suggest that this strong field region was generated as a result of compression of one umbra pushed by the horizontal flow from the other umbra, such as the subduction of the Earth’s crust in plate tectonics.

  2. Strongly coupled semidirect mediation of supersymmetry breaking

    International Nuclear Information System (INIS)

    Ibe, M.; Izawa, K.-I.; Nakai, Y.


    Strongly coupled semidirect gauge mediation models of supersymmetry breaking through massive mediators with standard-model charges are investigated by means of composite degrees of freedom. Sizable mediation is realized to generate the standard-model gaugino masses for a small mediator mass without breaking the standard-model symmetries.

  3. A Note on Strongly Dense Matrices

    Czech Academy of Sciences Publication Activity Database

    Fiedler, Miroslav; Hall, F.J.


    Roč. 1, č. 4 (2015), s. 721-730 ISSN 2199-675X Institutional support: RVO:67985807 Keywords : strongly dense matrix * Boolean matrix * nonnegative matrix * idempotent matrix * intrinsic product * generalized complementary basic matrix Subject RIV: BA - General Mathematics

  4. Strongly 2-connected orientations of graphs

    DEFF Research Database (Denmark)

    Thomassen, Carsten


    We prove that a graph admits a strongly 2-connected orientation if and only if it is 4-edge-connected, and every vertex-deleted subgraph is 2-edge-connected. In particular, every 4-connected graph has such an orientation while no cubic 3-connected graph has such an orientation....

  5. The Shape of Strongly Disturbed Dayside Magnetopause

    Directory of Open Access Journals (Sweden)

    Alexei V. Dmitriev Alla V. Suvorova


    Full Text Available During strong geomagnetic disturbances, the Earth¡¦s magnetosphere exhibits unusual and nonlinear interaction with the incident flow of magnetized solar wind plasma. Global Magneto-hydro-dynamic (MHD modeling of the magnetosphere predicts that the storm-time effects at the magnetopause result from the abnormal plasma transport and/or extremely strong field aligned currents. In-situ observations of the magnetospheric boundary, magnetopause, by Geosynchronous Operational Environmental Satellite (GOES allowed us to find experimentally such effects as a saturation of the dayside reconnection, unusual bluntness and prominent duskward skewing of the nose magnetopause. The saturation and duskward skewing were attributed to the storm-time magnetopause formation under strong southward interplanetary magnetic field (IMF. The unusual bluntness was observed during both high solar wind pressure and strong southward IMF. We suggest that these phenomena are caused by a substantial contribution of the cross-tail current magnetic field and the hot magnetospheric plasma from the asymmetrical ring current into the pressure balance at the dayside magnetopause.

  6. Potential Value of Genomic Copy Number Variations in Schizophrenia

    Directory of Open Access Journals (Sweden)

    Chuanjun Zhuo


    Full Text Available Schizophrenia is a devastating neuropsychiatric disorder affecting approximately 1% of the global population, and the disease has imposed a considerable burden on families and society. Although, the exact cause of schizophrenia remains unknown, several lines of scientific evidence have revealed that genetic variants are strongly correlated with the development and early onset of the disease. In fact, the heritability among patients suffering from schizophrenia is as high as 80%. Genomic copy number variations (CNVs are one of the main forms of genomic variations, ubiquitously occurring in the human genome. An increasing number of studies have shown that CNVs account for population diversity and genetically related diseases, including schizophrenia. The last decade has witnessed rapid advances in the development of novel genomic technologies, which have led to the identification of schizophrenia-associated CNVs, insight into the roles of the affected genes in their intervals in schizophrenia, and successful manipulation of the target CNVs. In this review, we focus on the recent discoveries of important CNVs that are associated with schizophrenia and outline the potential values that the study of CNVs will bring to the areas of schizophrenia research, diagnosis, and therapy. Furthermore, with the help of the novel genetic tool known as the Clustered Regularly Interspaced Short Palindromic Repeats-associated nuclease 9 (CRISPR/Cas9 system, the pathogenic CNVs as genomic defects could be corrected. In conclusion, the recent novel findings of schizophrenia-associated CNVs offer an exciting opportunity for schizophrenia research to decipher the pathological mechanisms underlying the onset and development of schizophrenia as well as to provide potential clinical applications in genetic counseling, diagnosis, and therapy for this complex mental disease.

  7. Deep convolutional neural networks as strong gravitational lens detectors (United States)

    Schaefer, C.; Geiger, M.; Kuntzer, T.; Kneib, J.-P.


    Context. Future large-scale surveys with high-resolution imaging will provide us with approximately 105 new strong galaxy-scale lenses. These strong-lensing systems will be contained in large data amounts, however, which are beyond the capacity of human experts to visually classify in an unbiased way. Aim. We present a new strong gravitational lens finder based on convolutional neural networks (CNNs). The method was applied to the strong-lensing challenge organized by the Bologna Lens Factory. It achieved first and third place, respectively, on the space-based data set and the ground-based data set. The goal was to find a fully automated lens finder for ground-based and space-based surveys that minimizes human inspection. Methods: We compared the results of our CNN architecture and three new variations ("invariant" "views" and "residual") on the simulated data of the challenge. Each method was trained separately five times on 17 000 simulated images, cross-validated using 3000 images, and then applied to a test set with 100 000 images. We used two different metrics for evaluation, the area under the receiver operating characteristic curve (AUC) score, and the recall with no false positive (Recall0FP). Results: For ground-based data, our best method achieved an AUC score of 0.977 and a Recall0FP of 0.50. For space-based data, our best method achieved an AUC score of 0.940 and a Recall0FP of 0.32. Adding dihedral invariance to the CNN architecture diminished the overall score on space-based data, but achieved a higher no-contamination recall. We found that using committees of five CNNs produced the best recall at zero contamination and consistently scored better AUC than a single CNN. Conclusions: We found that for every variation of our CNN lensfinder, we achieved AUC scores close to 1 within 6%. A deeper network did not outperform simpler CNN models either. This indicates that more complex networks are not needed to model the simulated lenses. To verify this, more

  8. Calculus of variations

    CERN Document Server

    Gelfand, I M


    Based on a series of lectures given by I. M. Gelfand at Moscow State University, this book actually goes considerably beyond the material presented in the lectures. The aim is to give a treatment of the elements of the calculus of variations in a form both easily understandable and sufficiently modern. Considerable attention is devoted to physical applications of variational methods, e.g., canonical equations, variational principles of mechanics, and conservation laws.The reader who merely wishes to become familiar with the most basic concepts and methods of the calculus of variations need on

  9. Strongly oscillating singularities for the interior transmission eigenvalue problem (United States)

    Bonnet-Ben Dhia, Anne-Sophie; Chesnel, Lucas


    In this paper, we investigate a two-dimensional interior transmission eigenvalue problem for an inclusion made of a composite material. We consider configurations where the difference between the parameters of the composite material and those of the background changes sign on the boundary of the inclusion. In a first step, under some assumptions on the parameters, we extend the variational approach of the T-coercivity to prove that the transmission eigenvalues form at most a discrete set. In the process, we also provide localization results. Then, we study what happens when these assumptions are not satisfied. The main idea is that, due to very strong singularities that can occur at the boundary, the problem may lose Fredholmness in the natural H1 framework. Using Kondratiev theory, we propose a new functional framework where the Fredholm property is restored.

  10. Anomalous radon emission as precursor of medium to strong earthquakes (United States)

    Zoran, Maria


    Anomalous radon (Rn222) emissions enhanced by forthcoming earthquakes is considered to be a precursory phenomenon related to an increased geotectonic activity in seismic areas. Rock microfracturing in the Earth's crust preceding a seismic rupture may cause local surface deformation fields, rock dislocations, charged particle generation and motion, electrical conductivity changes, radon and other gases emission, fluid diffusion, electrokinetic, piezomagnetic and piezoelectric effects as well as climate fluctuations. Space-time anomalies of radon gas emitted in underground water, soil and near the ground air weeks to days in the epicentral areas can be associated with the strain stress changes that occurred before the occurrence of medium and strong earthquakes. This paper aims to investigate temporal variations of radon concentration levels in air near or in the ground by the use of solid state nuclear track detectors (SSNTD) CR-39 and LR-115 in relation with some important seismic events recorded in Vrancea region, Romania.

  11. Regionally Strong Feedbacks between the Atmosphere and Terrestrial Biosphere (United States)

    Green, J. K.; Konings, A. G.; Alemohammad, S. H.; Berry, J. A.; Kolassa, J.; Lee, J. E.; Gentine, P.


    Vegetation variability modulates water and energy fluxes to the atmosphere with the potential to impact climate and weather patterns that in turn regulate vegetation dynamics. In this study, we quantify variations in the strength of biosphere-atmosphere feedbacks (influencing the hydrologic cycle) across different biomes and timescales and evaluate the ability of Earth System Models to capture them. We use remote sensing data (using Solar Induced Fluorescence as a proxy for photosynthesis) combined with a statistical Multivariate Granger Causality technique to evaluate the feedback strength and the timescale in which they occur, which is then used as a benchmark for model assessment. Our conclusions have the potential to improve climate and weather predictions and provide insight of ecohydrological processes that have regional scale impact (Green, J.K. et al. 2017). Green, Julia K., et al. Regionally strong feedbacks between the atmosphere and terrestrial biosphere. Nature Geoscience. 10, 410-414 (2017).

  12. Beyond strong and weak: rethinking postdictatorship civil societies. (United States)

    Riley, Dylan; Fernández, Juan J


    What is the impact of dictatorships on postdictatorial civil societies? Bottom-up theories suggest that totalitarian dictatorships destroy civil society while authoritarian ones allow for its development. Top-down theories of civil society suggest that totalitarianism can create civil societies while authoritarianism is unlikely to. This article argues that both these perspectives suffer from a one-dimensional understanding of civil society that conflates strength and autonomy. Accordingly we distinguish these two dimensions and argue that totalitarian dictatorships tend to create organizationally strong but heteronomous civil societies, while authoritarian ones tend to create relatively autonomous but organizationally weak civil societies. We then test this conceptualization by closely examining the historical connection between dictatorship and civil society development in Italy (a posttotalitarian case) and Spain (a postauthoritarian one). Our article concludes by reflecting on the implications of our argument for democratic theory, civil society theory, and theories of regime variation.

  13. Strong signatures of selection in the domestic pig genome

    DEFF Research Database (Denmark)

    Rubin, Carl-Johan; Megens, Hendrik-Jan; Barrio, Alvaro Martinez


    . We found an excess of derived nonsynonymous substitutions in domestic pigs, most likely reflecting both positive selection and relaxed purifying selection after domestication. Our analysis of structural variation revealed four duplications at the KIT locus that were exclusively present in white......Domestication of wild boar (Sus scrofa) and subsequent selection have resulted in dramatic phenotypic changes in domestic pigs for a number of traits, including behavior, body composition, reproduction, and coat color. Here we have used whole-genome resequencing to reveal some of the loci...... that underlie phenotypic evolution in European domestic pigs. Selective sweep analyses revealed strong signatures of selection at three loci harboring quantitative trait loci that explain a considerable part of one of the most characteristic morphological changes in the domestic pig—the elongation of the back...

  14. Global aerosol change in the last decade: An analysis based on MODIS data (United States)

    Mao, K. B.; Ma, Y.; Xia, L.; Chen, Wendy Y.; Shen, X. Y.; He, T. J.; Xu, T. R.


    Our understanding of the global aerosol change is rather limited, although it is well known that aerosol forcing could affect the global radiative budget, hydrological processes, carbon, nitrogen and sulfur cycles, as well as climate change. To understand the wide range effects of aerosols, it is key to obtain aerosol characteristics at high spatio-temporal resolutions. In this study, we try to map the global variations of the aerosol optical depth (AOD) using two aerosol products retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) satellite instrument. It is found that the global average AOD is 0.126 over the last decade (2003-2012). The highest and the lowest AOD occurred in 2007 and 2010, respectively. AOD variations between land and ocean, north and south hemispheres, among seven continents and four oceans were also explored. It is interesting to find that high concentrations of aerosols are mainly distributed in regions where developing countries are located (Asia and Africa), and an increasing trend could also be observed. Seasonal variations of AOD (air quality) can also be noted, which is decreasing in the north hemisphere from spring, summer to autumn and winter, but increasing in the south hemisphere.

  15. Decadal predictability of regional scale wind speed and wind energy potentials over Central Europe (United States)

    Moemken, Julia; Reyers, Mark; Buldmann, Benjamin; Pinto, Joaquim G.


    weather type with strong pressure gradients over Central Europe is identified as potential source for the skill for wind energy potentials, showing similar forecast skill and a high correlation with Eout anomalies. These results are promising regarding the establishment of a decadal prediction system for wind energy for Central Europe.

  16. Decadal temperature predictions over the continental United States: Analysis and Enhancement (United States)

    Salvi, Kaustubh; Villarini, Gabriele; Vecchi, Gabriel A.; Ghosh, Subimal


    Increases in global temperature over recent decades and the projected acceleration in warming trends over the 21 century have resulted in a strong need to obtain information about future temperature conditions. Hence, skillful decadal temperature predictions (DTPs) can have profound societal and economic benefits through informed planning and response. However, skillful and actionable DTPs are extremely challenging to achieve. Even though general circulation models (GCMs) provide decadal predictions of different climate variables, the direct use of GCM data for regional-scale impacts assessment is not encouraged because of the limited skill they possibly exhibit and their coarse spatial resolution. Here, we focus on 14 GCMs and evaluate seasonally and regionally averaged skills in DTPs over the continental United States. Moreover, we address the limitations in skill and spatial resolution in the GCM outputs using two data-driven approaches: (1) quantile-based bias correction and (2) linear regression-based statistical downscaling. For both the approaches, statistical parameters/relationships, established over the calibration period (1961-1990) are applied to retrospective and near future decadal predictions by GCMs to obtain DTPs at `4 km' resolution. Predictions are assessed using different evaluation metrics, long-term statistical properties, and uncertainty in terms of the range of predictions. Both the approaches adopted here show improvements with respect to the raw GCM data, particularly in terms of the long-term statistical properties and uncertainty, irrespective of lead time. The outcome of the study is monthly DTPs from 14 GCMs with a spatial resolution of 4 km, which can be used as a key input for impacts assessments.

  17. Tourette Syndrome and Tic Disorders: A Decade of Progress (United States)

    Swain, James E.; Scahill, Lawrence; Lombroso, Paul J.; King, Robert A.; Leckman, James F.


    Objective: This is a review of progress made in the understanding of Tourette syndrome (TS) during the past decade including models of pathogenesis, state-of-the-art assessment techniques, and treatment. Method: Computerized literature searches were conducted under the key words "Tourette syndrome," "Tourette disorder," and "tics." Only references…

  18. Electronic HRM: four decades of research on adoption and consequences

    NARCIS (Netherlands)

    Bondarouk, Tatiana; Parry, E.; Furtmueller-Ettinger, Elfriede


    Despite the existence of a number of recent reviews of e-HRM research, we still lack a comprehensive understanding of the factors affecting the adoption and consequences of e-HRM. This paper therefore provides a review of four decades of research in this area with the aim to provide a summary and

  19. Dynamic vehicle routing problems: Three decades and counting

    DEFF Research Database (Denmark)

    Psaraftis, Harilaos N.; Wen, Min; Kontovas, Christos A.


    Since the late 70s, much research activity has taken place on the class of dynamic vehicle routing problems (DVRP), with the time period after year 2000 witnessing areal explosion in related papers. Our paper sheds more light into work in this area over more than 3 decades by developing a taxonomy...

  20. A quasi-decadal cycle in Caribbean climate (United States)

    Jury, Mark R.


    Climatic variables in the period from 1951 to 2000 are analyzed across the tropics from the East Pacific to Africa. A quasi-decadal mode is isolated using singular value decomposition (SVD) applied to monthly smoothed and detrended rainfall, sea surface temperature (SST), sea level pressure (SLP), and 200 hPa zonal (U) wind anomalies. Seven- to 10-year cycles in Caribbean rainfall are revealed as the dominant mode (50% variance) and are found to be related to a mode of tropical variability that is distinct from previously known global signals. Sources of this signal include east Atlantic SST and the northern subtropical ridge, which modulate upwelling off Venezuela. SVD analysis of daily rainfall suggests interaction between annual and quasi-decadal signals, with northern summer convection as a driver. The second mode of Caribbean rainfall variability derives from the east Pacific El Niño Southern Oscillation (ENSO, 21% variance) that is expressed as an east-west dipole of convection across the Caribbean. Composite analysis of rainfall for high and low phases of the quasi-decadal cycle reveals a corresponding signal that extends from the eastern Pacific Ocean across the Caribbean and West Africa to India. The southern Hadley cell spins up during wet phase, and the ITCZ migrates northward. This hemispheric-scale anomaly brings pulses of convection to the Caribbean. Impacts of the quasi-decadal cycle on socioeconomic resources are investigated.

  1. Ignoring the Evidence: Another Decade of Decline for School Libraries (United States)

    Oberg, Dianne


    Four decades of research indicates that well-staffed, well-stocked, and well-used school libraries are correlated with increases in student achievement. Well-staffed school libraries have qualified teacher-librarians with qualifications in librarianship, digital technologies, and inquiry-based pedagogies. Well-stocked school libraries include…

  2. Media Coverage of International Women's Decade: Feminism and Conflict. (United States)

    Cooper, Anne; Davenport, Lucinda

    A study examined changes in the treatment of women's issues and feminism from 1975 to 1985--the United Nations (UN) designated "Women's Decade"--by two nationally circulated newspapers. The purpose was to find out how much and what kind of news was reported during the three UN World conferences for women held in 1975, 1980, and 1985;…

  3. Five decades in the study of natural products

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 114; Issue 3 ... Natural products; tylophora alkaloids; carpaine; tiliacorine; ishwarone; azadirachtin A. Abstract. This paper describes the five-decade long fascinating journey taken by Prof. T R Govindachari towards the study of the natural products of India. A variety of ...

  4. A Decade of Reform: Science and Technology Policy in China ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    In 1995, and at the request of the Chinese government, Canada's International Development Research Centre ( IDRC ) assembled a team of experts to assess the reforms to China's S&T sector — reforms that began in 1985 as an initiative of the State Science and Technology Commission (SSTC) of China. A Decade of ...

  5. Poverty and the American Family: A Decade in Review (United States)

    Edin, Kathryn; Kissane, Rebecca Joyce


    Because of dramatic levels of economic volatility and massive changes in welfare policies, scholars in this decade worried anew about whether our official poverty measure, adopted in the 1960s, is adequate. Poverty's causes continued to be debated, with demographic factors often pitted against policy and maternal employment changes. Some scholars…

  6. African Women Commuter Traders in Nairobi in the First Decade ...

    African Journals Online (AJOL)

    This article investigates African women commuter trading activities in Nairobi in the first decade after World War One. Its findings derive mainly from a research project carried out in 1989-1996. The major source of data for the study was oral interviews with the women who traded in Nairobi during the years under study, ...

  7. Four decades of conjoined twins at Red Cross Children's Hospital ...

    African Journals Online (AJOL)

    Four decades of conjoined twins at Red Cross Children's Hospital - lessons learned. H Rode, AG Fieggen, RA Brown, S Cywes, MRQ Davies, JP Hewitson, EB Hoffman, LD Jee, J Lawrenson, MD Mann, LS Matthews, AJW Millar, A Numanoglu, JC Peter, J Thomas, H Wainwright ...

  8. Four decades of conjoined twins at Red Cross Children's Hospital ...

    African Journals Online (AJOL)

    Conjoined twins represent a rare but fascinating congenital condition, the aetiology of which remains obscure. Over the past four decades, the paediatric surgeons at Red Cross Children's Hospital have been involved in the management of 4;6 pairs of conjoined twins, of which 33 have been symmetrical and 12 ...

  9. Apparel shopping orientation: Two decades of research | Visser ...

    African Journals Online (AJOL)

    Apparel shopping orientation: Two decades of research. EM Visser, R du Preez. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

  10. A Decade of Change in Australia's DBA Landscape (United States)

    Wallace, Michelle; Byrne, Cathy; Vocino, Andrea; Sloan, Terry; Pervan, Simon J.; Blackman, Deborah


    Purpose: The purpose of this paper is to examine the dynamics of the Doctorate of Business Administration (DBA) in Australia through the lens of a changing higher education landscape. The paper reflects on issues raised in a previous analysis of DBA programmes undertaken a decade ago, and highlights persistent challenges and emerging opportunities…

  11. A decade of experience with the European Company

    NARCIS (Netherlands)

    Cremers, J.; Stollt, M.; Vitols, S.


    A little more than a decade ago one of the most significant developments in European company law and worker participation occurred: the European Union passed a Regulation and Directive on the European Company (or Societas Europaea, hereafter SE). This legislation is a major innovation in that it

  12. Breastfeeding Duration Predicts Greater Maternal Sensitivity over the Next Decade (United States)

    Weaver, Jennifer M.; Schofield, Thomas J.; Papp, Lauren M.


    The current study represents the first longitudinal investigation of the potential effects of breastfeeding duration on maternal sensitivity over the following decade. This study also examined whether infant attachment security at 24 months would mediate longitudinal relations between breastfeeding duration and changes in maternal sensitivity over…

  13. Progress during the decade of the BSF beam-line

    International Nuclear Information System (INIS)

    Irie, Yoshiro; Adachi, Toshikazu; Yano, Yoshiharu; Fujimori, Hiroshi; Kaneko, Naokatsu; Kobayashi, Yasuo; Tahara, Toshihiro.


    Since the Booster Synchrotron Utilization Facility (BSF) came into operation in June, 1980, ten years have passed. This report summarizes the development of beam-line hardware and software system during the decade. Especially, the result on radiation protection along the beam-line is satisfactory. (author)

  14. Investigating MBA Degrees Earned by Women: A Decade of Change (United States)

    McConnell, Cheryl; Rush, Douglas; Gartland, Myles


    The authors examined master of business administration (MBA) degrees earned by women at U.S. higher education institutions at three specific years spanning a decade: 2003, 2008, and 2013 to determine whether there was a significant difference in the percentage of MBA degrees earned by women based on the independent variables of institutional type,…

  15. Participating in the UN Decade of Education for Sustainability ...

    African Journals Online (AJOL)

    Programme (SADC REEP) on participation in the United Nations Decade on Education for Sustainable. Development (UNDESD). Consultations ... was led by the SADC Regional Environmental Education Programme in 2005/2006, assisted by the. Rhodes University ...... (DRC ESD Consultation. Report). Leadership in ESD ...

  16. Gender and leadership styles : A review of the past decade

    NARCIS (Netherlands)

    van Engen, M.L.; Willemsen, T.M.


    Research on sex differences in leadership styles over the past decade (1987-1999) is reviewed and compared with the results of a meta-analysis of studies of the previous period by Eagly and Johnson (1990). Research on transformational or charismatic leadership is included in this review. As was the

  17. Decadal climate predictions improved by ocean ensemble dispersion filtering (United States)

    Kadow, C.; Illing, S.; Kröner, I.; Ulbrich, U.; Cubasch, U.


    Decadal predictions by Earth system models aim to capture the state and phase of the climate several years in advance. Atmosphere-ocean interaction plays an important role for such climate forecasts. While short-term weather forecasts represent an initial value problem and long-term climate projections represent a boundary condition problem, the decadal climate prediction falls in-between these two time scales. In recent years, more precise initialization techniques of coupled Earth system models and increased ensemble sizes have improved decadal predictions. However, climate models in general start losing the initialized signal and its predictive skill from one forecast year to the next. Here we show that the climate prediction skill of an Earth system model can be improved by a shift of the ocean state toward the ensemble mean of its individual members at seasonal intervals. We found that this procedure, called ensemble dispersion filter, results in more accurate results than the standard decadal prediction. Global mean and regional temperature, precipitation, and winter cyclone predictions show an increased skill up to 5 years ahead. Furthermore, the novel technique outperforms predictions with larger ensembles and higher resolution. Our results demonstrate how decadal climate predictions benefit from ocean ensemble dispersion filtering toward the ensemble mean.Plain Language SummaryDecadal predictions aim to predict the climate several years in advance. Atmosphere-ocean interaction plays an important role for such climate forecasts. The ocean memory due to its heat capacity holds big potential skill. In recent years, more precise initialization techniques of coupled Earth system models (incl. atmosphere and ocean) have improved decadal predictions. Ensembles are another important aspect. Applying slightly perturbed predictions to trigger the famous butterfly effect results in an ensemble. Instead of evaluating one prediction, but the whole ensemble with its

  18. Observations and 3D hydrodynamics-based modeling of decadal-scale shoreline change along the Outer Banks, North Carolina (United States)

    Safak, Ilgar; List, Jeffrey; Warner, John C.; Kumar, Nirnimesh


    Long-term decadal-scale shoreline change is an important parameter for quantifying the stability of coastal systems. The decadal-scale coastal change is controlled by processes that occur on short time scales (such as storms) and long-term processes (such as prevailing waves). The ability to predict decadal-scale shoreline change is not well established and the fundamental physical processes controlling this change are not well understood. Here we investigate the processes that create large-scale long-term shoreline change along the Outer Banks of North Carolina, an uninterrupted 60 km stretch of coastline, using both observations and a numerical modeling approach. Shoreline positions for a 24-yr period were derived from aerial photographs of the Outer Banks. Analysis of the shoreline position data showed that, although variable, the shoreline eroded an average of 1.5 m/yr throughout this period. The modeling approach uses a three-dimensional hydrodynamics-based numerical model coupled to a spectral wave model and simulates the full 24-yr time period on a spatial grid running on a short (second scale) time-step to compute the sediment transport patterns. The observations and the model results show similar magnitudes (O(105 m3/yr)) and patterns of alongshore sediment fluxes. Both the observed and the modeled alongshore sediment transport rates have more rapid changes at the north of our section due to continuously curving coastline, and possible effects of alongshore variations in shelf bathymetry. The southern section with a relatively uniform orientation, on the other hand, has less rapid transport rate changes. Alongshore gradients of the modeled sediment fluxes are translated into shoreline change rates that have agreement in some locations but vary in others. Differences between observations and model results are potentially influenced by geologic framework processes not included in the model. Both the observations and the model results show higher rates of

  19. Pediatric testicular cancer: Two decades of Saudi national data

    Directory of Open Access Journals (Sweden)

    Mohammed Abomelha


    Full Text Available Pediatric testicular cancer is exceedingly rare. There are no data available touching Saudi children. The aim of the study is to determine the trends and patterns of testicular cancer among Saudi children over a period of 20 years. The national database of the Saudi Cancer Registry (SCR on pediatric testicular cancer over the last two decades was examined including epidemiological and histological patterns. From 1994 to 2013, 82 cases of testicular cancer among Saudi children aged 1–14 years were accumulated at the SCR. The annual percentage change rate was 3.3%. Of all cases, 62% appeared within the first 2 years of life. Seminomas were seen in 39%, nonseminomas in 40.3%, and paratesticular tumors in 20.7%. No gonadal stromal tumors observed. About 91% of the seminomas accrued in the first decade (1994–2003, while all nonseminomas fell in the last decade (2004–2013. The most common subtypes of the nonseminomas were yolk sac tumors and mixed tumors. More than 80% of the paratesticular tumors were rhabdomyosarcomas and lymphomas. The SEER summary stage of seminomas was localized in 56%, regional in 22%, and distant in 16%, while of nonseminomas was 56%, 16%, and 28%, respectively, and no stage improvement over the studied period was noted. No temporal trend in incidence rate was observed. The most affected age group was the first 2 years of life. Noteworthy was the high incidence of seminoma and the low rate of teratomas and stromal tumors, when compared to Western data. Notable was the dominance of the seminomas in the first decade and of the nonseminomas in the second decade. At the time of diagnosis, nonseminomas were more advanced than seminomas. No stage improvement noted over the studied period.

  20. Infective endocarditis epidemiology over five decades: a systematic review.

    Directory of Open Access Journals (Sweden)

    Leandro Slipczuk

    Full Text Available AIMS: To Assess changes in infective endocarditis (IE epidemiology over the last 5 decades. METHODS AND RESULTS: We searched the published literature using PubMed, MEDLINE, and EMBASE from inception until December 2011. DATA FROM: Einstein Medical Center, Philadelphia, PA were also included. Criteria for inclusion in this systematic review included studies with reported IE microbiology, IE definition, description of population studied, and time frame. Two authors independently extracted data and assessed manuscript quality. One hundred sixty studies (27,083 patients met inclusion criteria. Among hospital-based studies (n=142; 23,606 patients staphylococcal IE percentage increased over time, with coagulase-negative staphylococcus (CNS increasing over each of the last 5 decades (p<0.001 and Staphylococcus aureus (SA in the last decade (21% to 30%; p<0.05. Streptococcus viridans (SV and culture negative (CN IE frequency decreased over time (p<0.001, while enterococcal IE increased in the last decade (p<0.01. Patient age and male predominance increased over time as well. In subgroup analysis, SA frequency increased in North America, but not the rest of the world. This was due, in part, to an increase in intravenous drug abuse IE in North America (p<0.001. Among population-based studies (n=18; 3,477 patients no significant changes were found. CONCLUSION: Important changes occurred in IE epidemiology over the last half-century, especially in the last decade. Staphylococcal and enterococcal IE percentage increased while SV and CN IE decreased. Moreover, mean age at diagnosis increased together with male:female ratio. These changes should be considered at the time of decision-making in treatment of and prophylaxis for IE.