Effects of Varying Entry Points and Trendelenburg Positioning ...

African Journals Online (AJOL)

2018-04-04

Apr 4, 2018 ... ... made in superior and inferior entry points at supine position at 0° .... Trendelenburg degree, taking all risks into consideration. As a result of our .... patient's position influences the incidence of dysrhythmias during pulmonary.

Global Exponential Stability of Positive Almost Periodic Solutions for a Fishing Model with a Time-Varying Delay

Directory of Open Access Journals (Sweden)

Hong Zhang

2014-01-01

Full Text Available This paper is concerned with a nonautonomous fishing model with a time-varying delay. Under proper conditions, we employ a novel argument to establish a criterion on the global exponential stability of positive almost periodic solutions of the model with almost periodic coefficients and delays. Moreover, an example and its numerical simulation are given to illustrate the main results.

Tourism's impacts on natural resources: A positive case from China.

Science.gov (United States)

Li, Wenjun; Zhang, Qian; Liu, Chunyan; Xue, Qifu

2006-10-01

Tourism development may result in negative impacts on natural resources owing to overuse and mismanagement. However, tourism may also play positive roles in natural resource conservation, which has rarely been verified in practice, although some researchers have demonstrated this in theory. In this article, taking the Jiuzhaigou Biosphere Reserve as a case study area, we conducted an analysis for the environmental impacts from tourism development based on social survey and interpretation of remote sensing images. The results show that the natural environment was not degraded and some indicators are even improving because all the residents have participated in tourism and given up farming and hunting. It is concluded that it is possible to use tourism as a way to balance natural resource conservation and economic development under the preconditions of making effective policies to encourage and help local people participate in tourism business and to benefit from it.

Tourism's Impacts on Natural Resources: A Positive Case from China

Science.gov (United States)

Li, Wenjun; Zhang, Qian; Liu, Chunyan; Xue, Qifu

2006-10-01

Tourism development may result in negative impacts on natural resources owing to overuse and mismanagement. However, tourism may also play positive roles in natural resource conservation, which has rarely been verified in practice, although some researchers have demonstrated this in theory. In this article, taking the Jiuzhaigou Biosphere Reserve as a case study area, we conducted an analysis for the environmental impacts from tourism development based on social survey and interpretation of remote sensing images. The results show that the natural environment was not degraded and some indicators are even improving because all the residents have participated in tourism and given up farming and hunting. It is concluded that it is possible to use tourism as a way to balance natural resource conservation and economic development under the preconditions of making effective policies to encourage and help local people participate in tourism business and to benefit from it.

Daily fluctuations in positive affect positively co-vary with working memory performance.

Science.gov (United States)

Brose, Annette; Lövdén, Martin; Schmiedek, Florian

2014-02-01

Positive affect is related to cognitive performance in multiple ways. It is associated with motivational aspects of performance, affective states capture attention, and information processing modes are a function of affect. In this study, we examined whether these links are relevant within individuals across time when they experience minor ups and downs of positive affect and work on cognitive tasks in the laboratory on a day-to-day basis. Using a microlongitudinal design, 101 younger adults (20-31 years of age) worked on 3 working memory tasks on about 100 occasions. Every day, they also reported on their momentary affect and their motivation to work on the tasks. In 2 of the 3 tasks, performance was enhanced on days when positive affect was above average. This performance enhancement was also associated with more motivation. Importantly, increases in task performance on days with above-average positive affect were mainly unrelated to variations in negative affect. This study's results are in line with between-person findings suggesting that high levels of well-being are associated with successful outcomes. They imply that success on cognitively demanding tasks is more likely on days when feeling happier. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Position-specific 13C distributions within propane from experiments and natural gas samples

Science.gov (United States)

Piasecki, Alison; Sessions, Alex L.; Lawson, Michael; Ferreira, A.A.; Santos Neto, E. V.; Ellis, Geoffrey S.; Lewan, Michael; Eilers, J.M.

2018-01-01

Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, ‘bulk’ isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one molecular site versus another. Most recent studies of site-specific 13C in organics use specialized Nuclear Magnetic Resonance (NMR) techniques or complex chemical degradations prior to mass spectrometric measurements. Herein we present the first application of a new mass spectrometric technique that reconstructs the site-specific carbon isotope composition of propane based on measurements of the 13C/12C ratios of two or more fragment ions that sample different proportions of the terminal and central carbon sites. We apply this method to propane from laboratory experiments and natural gas samples to explore the relationships between site-specific carbon isotope composition, full-molecular δ13C, thermal maturity, and variation in organic matter precursors. Our goal is to advance the understanding of the sources and histories of short-chain alkanes within geologic systems. Our findings suggest that propane varies in its site-specific carbon isotope structure, which is correlated with increasing thermal maturity, first increasing in terminal position δ13C and then increasing in both center and terminal position δ13C. This pattern is observed in both experimental and natural samples, and is plausibly explained by a combination of site-specific, temperature-dependent isotope effects associated with conversion of different precursor molecules (kerogen, bitumen, and/or oil) to propane, differences in site-specific isotopic contents of those precursors, and possibly distillation of reactive components of those precursors with increasing maturity. We hypothesize that the largest changes in

Position-specific 13C distributions within propane from experiments and natural gas samples

Science.gov (United States)

Piasecki, Alison; Sessions, Alex; Lawson, Michael; Ferreira, A. A.; Santos Neto, E. V.; Ellis, Geoffrey S.; Lewan, Michael D.; Eiler, John M.

2018-01-01

Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, 'bulk' isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend to concentrate heavy isotopes in one molecular site versus another. Most recent studies of site-specific 13C in organics use specialized Nuclear Magnetic Resonance (NMR) techniques or complex chemical degradations prior to mass spectrometric measurements. Herein we present the first application of a new mass spectrometric technique that reconstructs the site-specific carbon isotope composition of propane based on measurements of the 13C/12C ratios of two or more fragment ions that sample different proportions of the terminal and central carbon sites. We apply this method to propane from laboratory experiments and natural gas samples to explore the relationships between site-specific carbon isotope composition, full-molecular δ13C, thermal maturity, and variation in organic matter precursors. Our goal is to advance the understanding of the sources and histories of short-chain alkanes within geologic systems. Our findings suggest that propane varies in its site-specific carbon isotope structure, which is correlated with increasing thermal maturity, first increasing in terminal position δ13C and then increasing in both center and terminal position δ13C. This pattern is observed in both experimental and natural samples, and is plausibly explained by a combination of site-specific, temperature-dependent isotope effects associated with conversion of different precursor molecules (kerogen, bitumen, and/or oil) to propane, differences in site-specific isotopic contents of those precursors, and possibly distillation of reactive components of those precursors with increasing maturity. We hypothesize that the largest changes in

Natural gas position in the energy sector of the 21. century

International Nuclear Information System (INIS)

Peltier, Th.

2000-01-01

Natural gas with its abundant reserves, largely distributed all around the world, and with its low environmental impacts, should assert its position since the beginning of the 21. century. However, the fundamentals of our world are changing more and more rapidly and some short term events can modify this long term optimistic vision of natural gas development. This was the topic debated during a round table of the WOC 9 working committee of the CMG 2000 worldwide gas congress: the long term future of natural gas industry, the population need for a sustainable development, the potentialities of gas resources, the need for large scale interconnected energy networks, the new technologies favourable to the development of natural gas uses, the progressive 'decarbonization' of energy sources, the global warming and the role of R and D, the risks that could threat natural gas development. (J.S.)

Positive Selection or Free to Vary? Assessing the Functional Significance of Sequence Change Using Molecular Dynamics.

Directory of Open Access Journals (Sweden)

Jane R Allison

Full Text Available Evolutionary arms races between pathogens and their hosts may be manifested as selection for rapid evolutionary change of key genes, and are sometimes detectable through sequence-level analyses. In the case of protein-coding genes, such analyses frequently predict that specific codons are under positive selection. However, detecting positive selection can be non-trivial, and false positive predictions are a common concern in such analyses. It is therefore helpful to place such predictions within a structural and functional context. Here, we focus on the p19 protein from tombusviruses. P19 is a homodimer that sequesters siRNAs, thereby preventing the host RNAi machinery from shutting down viral infection. Sequence analysis of the p19 gene is complicated by the fact that it is constrained at the sequence level by overprinting of a viral movement protein gene. Using homology modeling, in silico mutation and molecular dynamics simulations, we assess how non-synonymous changes to two residues involved in forming the dimer interface-one invariant, and one predicted to be under positive selection-impact molecular function. Interestingly, we find that both observed variation and potential variation (where a non-synonymous change to p19 would be synonymous for the overprinted movement protein does not significantly impact protein structure or RNA binding. Consequently, while several methods identify residues at the dimer interface as being under positive selection, MD results suggest they are functionally indistinguishable from a site that is free to vary. Our analyses serve as a caveat to using sequence-level analyses in isolation to detect and assess positive selection, and emphasize the importance of also accounting for how non-synonymous changes impact structure and function.

Manipulation of cells' position across a microfluidic channel using a series of continuously varying herringbone structures

Science.gov (United States)

Jung, Yugyung; Hyun, Ji-chul; Choi, Jongchan; Atajanov, Arslan; Yang, Sung

2017-12-01

Controlling cells' movement is an important technique in biological analysis that is performed within a microfluidic system. Many external forces are utilized for manipulation of cells, including their position in the channel. These forces can effectively control cells in a desired manner. Most of techniques used to manipulate cells require sophisticated set-ups and equipment to generate desired effect. The exception to this is the use of hydrodynamic force. In this study, a series of continuously varying herringbone structures is proposed for positioning cells in a microfluidic channel using hydrodynamic force. This structure was experimentally developed by changing parameters, such as the length of the herringbone's apex, the length of the herringbone's base and the ratio of the height of the flat channel to the height of the herringbone structure. Results of this study, have demonstrated that the length of the herringbone's apex and the ratio of the heights of the flat channel and the herringbone structure were crucial parameters influencing positioning of cells at 100 μl/h flow rate. The final design was fixed at 170 and 80 μm for the length of herringbone's apex and the length of herringbone's base, respectively. The average position of cells in this device was 34 μm away from the side wall in a 200 μm wide channel. Finally, to substantiate a practical application of the herringbone structure for positioning, cells were randomly introduced into a microfluidic device, containing an array of trapping structures together with a series of herringbone structures along the channel. The cells were moved toward the trapping structure by the herringbone structure and the trapping efficiency was increased. Therefore, it is anticipated that this device will be utilized to continuously control cells' position without application of external forces.

Positive and negative variations in capacitive images for given defects under varying experimental conditions

Science.gov (United States)

Li, Chen; Yin, Xiaokang; Li, Zhen; Li, Wei; Chen, Guoming

2018-04-01

Capacitive imaging (CI) technique is a novel electromagnetic NDE technique. The Quasi-static electromagnetic field from the carefully designed electrode pair will vary when the electrical properties of the sample change, leading to the possibility of imaging. It is observed that for a given specimen, the targeted features appear as different variations in capacitive images under different experimental conditions. In some cases, even opposite variations occur, which brings confusion to indication interpretation. It is thus thought interesting to embark on investigations into the cause and effects of the negative variation phenomenon. In this work, the positive and negative variations were first explained from the measurement sensitivity distribution perspective. This was then followed by a detailed analysis using finite element models in COMSOL. A parametric experimental study on a glass fiber composite plate with artificial defects was then carried out to investigate how the experimental conditions affect the variation.

The co-movement of monetary policy and its time-varying nature: A DCCA approach

Science.gov (United States)

Rohit, Abhishek; Mitra, Subrata Kumar

2018-02-01

Employing a novel methodology of DCCA cross-correlation coefficient (ρDCCA), this study attempts to provide fresh evidences for the co-movement of monetary policies of the advanced (AEs) as well as the emerging economies (EMEs) vis-à-vis the United States. A higher degree of monetary co-movement as measured by ρDCCA values, is identified for the AEs as compared to the EMEs. Lower co-movement of monetary policy is especially noticeable in the short run for EMEs. We further investigate the time-varying nature of such co-movements for the AEs by splitting the period (1980-2014) into four sub periods and also by performing a rolling window estimation for the entire period to reveal smoother dynamics. Significant evidence of higher monetary coordination is revealed for sub-periods with stronger trade and financial linkages.

Which way the natural gas price. An attempt to predict the direction of natural gas spot price movements using trader positions

International Nuclear Information System (INIS)

Buchanan, W.K.; Hodges, P.; Theis, J.

2001-01-01

This research provides a method of predicting direction of spot price movements in the natural gas market for the month succeeding from market participants positions in the futures market. Cumby and Modest (Cumby, R.E., Modest, D.M., 1987. Testing for market timing ability: a framework for forecast evaluation. Journal of Financial Economics 19, 169-189) provide the backdrop for analyzing the futures market positions of large hedgers and speculators to arrive at conclusions of market price movements in the spot market. This methodology is suggested as a means for municipalities entering the natural gas market to improve upon their ordering of quantities of gas for the ensuing months in order to take advantage of possibly foreseeable price trends

Statistics of natural binaural sounds.

Directory of Open Access Journals (Sweden)

Wiktor Młynarski

Full Text Available Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD and level (ILD disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA. Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Statistics of natural binaural sounds.

Science.gov (United States)

Młynarski, Wiktor; Jost, Jürgen

2014-01-01

Binaural sound localization is usually considered a discrimination task, where interaural phase (IPD) and level (ILD) disparities at narrowly tuned frequency channels are utilized to identify a position of a sound source. In natural conditions however, binaural circuits are exposed to a stimulation by sound waves originating from multiple, often moving and overlapping sources. Therefore statistics of binaural cues depend on acoustic properties and the spatial configuration of the environment. Distribution of cues encountered naturally and their dependence on physical properties of an auditory scene have not been studied before. In the present work we analyzed statistics of naturally encountered binaural sounds. We performed binaural recordings of three auditory scenes with varying spatial configuration and analyzed empirical cue distributions from each scene. We have found that certain properties such as the spread of IPD distributions as well as an overall shape of ILD distributions do not vary strongly between different auditory scenes. Moreover, we found that ILD distributions vary much weaker across frequency channels and IPDs often attain much higher values, than can be predicted from head filtering properties. In order to understand the complexity of the binaural hearing task in the natural environment, sound waveforms were analyzed by performing Independent Component Analysis (ICA). Properties of learned basis functions indicate that in natural conditions soundwaves in each ear are predominantly generated by independent sources. This implies that the real-world sound localization must rely on mechanisms more complex than a mere cue extraction.

Delay-Range-Dependent H∞ Control for Automatic Mooring Positioning System with Time-Varying Input Delay

Directory of Open Access Journals (Sweden)

Xiaoyu Su

2014-01-01

Full Text Available Aiming at the economy and security of the positioning system in semi-submersible platform, the paper presents a new scheme based on the mooring line switching strategy. Considering the input delay in switching process, H∞ control with time-varying input delay is designed to calculate the control forces to resist disturbing forces. In order to reduce the conservativeness, the information of the lower bound of delay is taken into account, and a Lyapunov function which contains the range of delay is constructed. Besides, the input constraint is considered to avoid breakage of mooring lines. The sufficient conditions for delay-range-dependent stabilization are derived in terms of LMI, and the controller is also obtained. The effectiveness of the proposed approach is illustrated by a realistic design example.

Comparison of Natural Head Position in Different Anteroposterior Malocclusions

Directory of Open Access Journals (Sweden)

Zohreh Hedayati

2013-01-01

Full Text Available Objective: The facial esthetics after orthodontic treatment and orthognathic surgery may be affected by the patient’s natural head position. The purpose of this study was to evaluate the natural head position for the three skeletal classes of malocclusion.Materials and Methods: Our sample consisted of 102 lateral cephalometric radiographs of patients aged 15 to 18 years; class I (n=32, class II (n=40 and class III (n=30. Nine landmarks of the craniofacial skeleton and three landmarks of the cervical vertebrae were determined. Variables consisted of two angles for cervical posture (OPT/Hor and CVT/Hor, three angles for craniofacial posture (SN/Ver, PNS-ANS/Ver, and ML/Ver and five for craniofacial angulation (SN/OPT, SN/CVT, PNS-ANS/OPT, PNS-ANS/CVT, ML/CVT. The data were analyzed statistically using ANOVA and post hoc tests.Results: PNS-ANS/Ver and SN/Ver differed significantly (p<0.05 among the three groups. There were no significant differences between class I and class II malocclusions for the indicator angles of cranial posture except for ML/Ver. The SN/CVT was significantly different for class I compared to class III patients. A head posture camouflaging the underlying skeletal class III was observed in our population.Conclusion: A more forward head posture was observed in skeletal class III participants compared to skeletal class I and II and that class III patients tended to incline their head more ventral compared to class I participants. These findings may have implications for the amount of jaw movements during surgery particularly in patients with a class III malocclusion

Into the Woods or a Stroll in the Park: How Virtual Contact with Nature Impacts Positive and Negative Affect.

Science.gov (United States)

McAllister, Elizabeth; Bhullar, Navjot; Schutte, Nicola S

2017-07-14

This study examined the effects of virtual contact with nature on positive and negative affect, and investigated the psychological process of perceived restorativeness as a mediator of this relationship. A sample of 220 Australians aged between 18 and 75 years (M = 49.07, SD = 14.34, female = 72%) participated in the study. Participants were randomly allocated to one of the three experimental conditions experienced through video presentations: (1) 'wild' nature, (2) 'urban' nature, and (3) non-nature control. They then completed measures of perceived restorativeness as well as positive and negative affect. Compared to the non-nature control condition, the experience of wild nature resulted in significantly higher levels of positive affect and lower levels of negative affect. The experience of urban nature resulted in significantly lower levels of negative affect only compared to the non-nature control video. Experience of wild and urban nature resulted in greater perceptions of restorativeness as compared to the non-nature control video. Restorativeness was a significant underlying psychological mediating path through which nature experience exerted its influence on affect. These results have the potential to inform nature-based green care interventions for mental health as well as for urban planning to maximize beneficial effects of natural environments.

Frequency variations of gravity waves interacting with a time-varying tide

Energy Technology Data Exchange (ETDEWEB)

Huang, C.M.; Zhang, S.D.; Yi, F.; Huang, K.M.; Gan, Q.; Gong, Y. [Wuhan Univ., Hubei (China). School of Electronic Information; Ministry of Education, Wuhan, Hubei (China). Key Lab. of Geospace Environment and Geodesy; State Observatory for Atmospheric Remote Sensing, Wuhan, Hubei (China); Zhang, Y.H. [Nanjing Univ. of Information Science and Technology (China). College of Hydrometeorolgy

2013-11-01

Using a nonlinear, 2-D time-dependent numerical model, we simulate the propagation of gravity waves (GWs) in a time-varying tide. Our simulations show that when aGW packet propagates in a time-varying tidal-wind environment, not only its intrinsic frequency but also its ground-based frequency would change significantly. The tidal horizontal-wind acceleration dominates the GW frequency variation. Positive (negative) accelerations induce frequency increases (decreases) with time. More interestingly, tidal-wind acceleration near the critical layers always causes the GW frequency to increase, which may partially explain the observations that high-frequency GW components are more dominant in the middle and upper atmosphere than in the lower atmosphere. The combination of the increased ground-based frequency of propagating GWs in a time-varying tidal-wind field and the transient nature of the critical layer induced by a time-varying tidal zonal wind creates favorable conditions for GWs to penetrate their originally expected critical layers. Consequently, GWs have an impact on the background atmosphere at much higher altitudes than expected, which indicates that the dynamical effects of tidal-GW interactions are more complicated than usually taken into account by GW parameterizations in global models.

Positivity, discontinuity, finite resources, and nonzero error for arbitrarily varying quantum channels

International Nuclear Information System (INIS)

Boche, H.; Nötzel, J.

2014-01-01

This work is motivated by a quite general question: Under which circumstances are the capacities of information transmission systems continuous? The research is explicitly carried out on finite arbitrarily varying quantum channels (AVQCs). We give an explicit example that answers the recent question whether the transmission of messages over AVQCs can benefit from assistance by distribution of randomness between the legitimate sender and receiver in the affirmative. The specific class of channels introduced in that example is then extended to show that the unassisted capacity does have discontinuity points, while it is known that the randomness-assisted capacity is always continuous in the channel. We characterize the discontinuity points and prove that the unassisted capacity is always continuous around its positivity points. After having established shared randomness as an important resource, we quantify the interplay between the distribution of finite amounts of randomness between the legitimate sender and receiver, the (nonzero) probability of a decoding error with respect to the average error criterion and the number of messages that can be sent over a finite number of channel uses. We relate our results to the entanglement transmission capacities of finite AVQCs, where the role of shared randomness is not yet well understood, and give a new sufficient criterion for the entanglement transmission capacity with randomness assistance to vanish

Natural Selection in the Great Apes.

Science.gov (United States)

Cagan, Alexander; Theunert, Christoph; Laayouni, Hafid; Santpere, Gabriel; Pybus, Marc; Casals, Ferran; Prüfer, Kay; Navarro, Arcadi; Marques-Bonet, Tomas; Bertranpetit, Jaume; Andrés, Aida M

2016-12-01

Natural selection is crucial for the adaptation of populations to their environments. Here, we present the first global study of natural selection in the Hominidae (humans and great apes) based on genome-wide information from population samples representing all extant species (including most subspecies). Combining several neutrality tests we create a multi-species map of signatures of natural selection covering all major types of natural selection. We find that the estimated efficiency of both purifying and positive selection varies between species and is significantly correlated with their long-term effective population size. Thus, even the modest differences in population size among the closely related Hominidae lineages have resulted in differences in their ability to remove deleterious alleles and to adapt to changing environments. Most signatures of balancing and positive selection are species-specific, with signatures of balancing selection more often being shared among species. We also identify loci with evidence of positive selection across several lineages. Notably, we detect signatures of positive selection in several genes related to brain function, anatomy, diet and immune processes. Our results contribute to a better understanding of human evolution by putting the evidence of natural selection in humans within its larger evolutionary context. The global map of natural selection in our closest living relatives is available as an interactive browser at http://tinyurl.com/nf8qmzh. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The Influence of Natural Head Position on the Cervical Sagittal Alignment

Directory of Open Access Journals (Sweden)

Kuan Wang

2017-01-01

Full Text Available Introduction. This study investigated the relationship between the parameters related to the natural head position and cervical segmental angles and alignment of patients with neck pain. Material and Methods. The lateral radiographs of the cervical spine were collected from 103 patients and were used to retrospectively analyze the correlation between the natural head position, cervical local sagittal angles, and alignment. Sagittal measurements were as follows: cervical curvature classification, slope of McGregor’s line (McGS, local sagittal angles (C0–C2 angle, C2–C5 angle, C5–C7 angle, and C2–C7 angle, T1 slope, center of gravity of the head to sagittal vertical axis (CG–C7 SVA, and local sagittal alignment (C0–C2 SVA and C2–C7 SVA. Results. McGS was significantly correlated to C0–C2 angle (r=0.57, C0–C2 SVA (r=−0.53, C2–C7 SVA (r=−0.28, and CG–C7 SVA (r=−0.47. CG–C7 SVA was also significantly correlated to curvature type (r=0.27, C5–C7 angle (r=−0.37, and C2–C7 angle (r=−0.39. Conclusions. A backward shift with an extended head position may accompany a relatively normal curvature of the cervical spine. The effect of posture control in relieving abnormal mechanical state of the cervical spine needs to be further confirmed by biomechanical analysis.

Green Schoolyards in Low-Income Urban Neighborhoods: Natural Spaces for Positive Youth Development Outcomes

Directory of Open Access Journals (Sweden)

Carolyn R. Bates

2018-05-01

Full Text Available Children from low-income families are increasingly growing up in urban areas with limited access to nature. In these environments, strategies that promote access to natural outdoor spaces, such as green schoolyards, may enhance positive youth development outcomes by promoting physical activity (PA and prosocial behavior, as well as increasing perceptions of safety. The current study examines children’s PA and social interactions, as well as caregiver and teacher perceptions of safety, injuries, teasing/bullying, and gang activity on three newly renovated green schoolyards in low-income urban neighborhoods. A multi-method strategy, including behavioral mapping and caregiver- and teacher-reported surveys, was utilized at three time points to examine positive youth development outcomes and maintenance of effects over time. Analyses revealed that children evidenced a range of PA on the green schoolyards and demonstrated significant decreases in sedentary activity over time. The majority of children were engaged in social interactions with peers on the green schoolyards when observed. Less than 3% of interactions were negative and follow-up analyses found significant increases in positive interactions on the green schoolyards up to 24 months post-renovation. Caregivers and teachers reported increased perceptions of safety, fewer injuries, less teasing/bullying, and less gang-related activity on the renovated green schoolyards in comparison to the pre-renovation schoolyards, and these effects were maintained up to 32 months post-renovation. Overall, the study suggests that green schoolyards may promote positive development outcomes among youth living in urban, low-income neighborhoods by providing natural and safe spaces for PA and prosocial behavior.

Position paper on the impact of including methane number in natural gas regulation

International Nuclear Information System (INIS)

2014-01-01

GIIGNL has developed a position paper to describe methane number and the possible impact on the LNG market of a future regulation/specification for this parameter which is linked to natural gas quality. Currently, there are several standards describing calculation methods of natural gas methane number, but there are doubts about their reliability and the results differ from each other. No official regulation which states a minimum value for methane number of natural gas has been identified. A methane number of 80, as recommended by some organisations in Europe, would endanger the LNG supply to the market, limiting acceptable LNG sources, or would require expensive gas treatment. In the long term, if there is a market for high methane number natural gas, this may be an opportunity for LNG terminals able to adjust or manage supplies to the desired methane number

Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background.

Directory of Open Access Journals (Sweden)

Saskia Decuypere

Full Text Available The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L. donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread

Effects of natural disaster trends: a case study for expanding the pre-positioning network of CARE International.

Science.gov (United States)

Bozkurt, Melda; Duran, Serhan

2012-08-01

The increasing number of natural disasters in the last decade necessitates the increase in capacity and agility while delivering humanitarian relief. A common logistics strategy used by humanitarian organizations to respond this need is the establishment of pre-positioning warehouse networks. In the pre-positioning strategy, critical relief inventories are located near the regions at which they will be needed in advance of the onset of the disaster. Therefore, pre-positioning reduces the response time by totally or partially eliminating the procurement phase and increasing the availability of relief items just after the disaster strikes. Once the pre-positioning warehouse locations are decided and warehouses on those locations become operational, they will be in use for a long time. Therefore, the chosen locations should be robust enough to enable extensions, and to cope with changing trends in disaster types, locations and magnitudes. In this study, we analyze the effects of natural disaster trends on the expansion plan of pre-positioning warehouse network implemented by CARE International. We utilize a facility location model to identify the additional warehouse location(s) for relief items to be stored as an extension of the current warehouse network operated by CARE International, considering changing natural disaster trends observed over the past three decades.

The Scope of Our Affective Influences: When and How Naturally Occurring Positive, Negative, and Neutral Affects Alter Judgment.

Science.gov (United States)

Gasper, Karen; Danube, Cinnamon L

2016-03-01

To determine how naturally arising affect alters judgment, we examined whether (a) affective states exert a specific, rather than a general, influence on valenced-specific judgments; (b) neutral affect is associated with increased neutral judgments, independent of positive, negative, and ambivalent affects, and whether neutral judgments are associated with behavioral disengagement; and (c) the informational value of naturally arising states may be difficult to alter via salience and relevance manipulations. The results support several conclusions: (a) Affective states exerted a judgment-specific effect-positive affect was most strongly associated with positive judgments, negative affect with negative judgments, and neutral affect with neutral judgments. (b) Neutral affect influenced judgments, taking into account positive, negative, and ambivalent affects; and neutral judgments predicted behavioral disengagement. (c) With the exception of negative affect, naturally arising affective states typically influenced judgments regardless of their salience and relevance. © 2016 by the Society for Personality and Social Psychology, Inc.

The relationship between global oil price shocks and China's output: A time-varying analysis

International Nuclear Information System (INIS)

Cross, Jamie; Nguyen, Bao H.

2017-01-01

We employ a class of time-varying Bayesian vector autoregressive (VAR) models on new standard dataset of China's GDP constructed by to examine the relationship between China's economic growth and global oil market fluctuations between 1992Q1 and 2015Q3. We find that: (1) the time varying parameter VAR with stochastic volatility provides a better fit as compared to it's constant counterparts; (2) the impacts of intertemporal global oil price shocks on China's output are often small and temporary in nature; (3) oil supply and specific oil demand shocks generally produce negative movements in China's GDP growth whilst oil demand shocks tend to have positive effects; (4) domestic output shocks have no significant impact on price or quantity movements within the global oil market. The results are generally robust to three commonly employed indicators of global economic activity: Kilian's global real economic activity index, the metal price index and the global industrial production index, and two alternative oil price metrics: the US refiners' acquisition cost for imported crude oil and the West Texas Intermediate price of crude oil. - Highlights: • A class of time-varying BVARs is used to examine the relationship between China's economic growth and global oil market fluctuations. • The impacts of intertemporal global oil price shocks on China's output are often small and temporary in nature. • Oil supply and specific oil demand shocks generally produce negative movements in China's GDP growth while oil demand shocks tend to have positive effects. • Domestic output shocks have no significant impact on price or quantity movements within the global oil market.

Dissolved organic matter signatures vary between naturally acidic, circumneutral and groundwater-fed freshwaters in Australia.

Science.gov (United States)

Holland, Aleicia; Stauber, Jenny; Wood, Chris M; Trenfield, Melanie; Jolley, Dianne F

2018-06-15

Dissolved organic matter (DOM) plays important roles in both abiotic and biotic processes within aquatic ecosystems, and these in turn depend on the quality of the DOM. We collected and characterized chromophoric DOM (CDOM) from different Australian freshwater types (circumneutral, naturally acidic and groundwater-fed waterways), climatic regions and seasons. CDOM quality was characterized using absorbance and fluorescence spectroscopy. Excitation emission scans followed by parallel factor (PARAFAC) analysis showed that CDOM was characterized by three main components: protein-like, fulvic-like and humic-like components commonly associated with various waters globally in the Openfluor database. Principal component analysis showed that CDOM quality varied between naturally acidic, circumneutral and groundwater-fed waters, with unique CDOM quality signatures shown for each freshwater type. CDOM quality also differed significantly within some sites between seasons. Clear differences in dominant CDOM components were shown between freshwater types. Naturally acidic waters were dominated by highly aromatic (as indicated by the specific absorbance co-efficient (SAC 340 ) and the specific UV absorbance (SUVA 254 ) values which ranged between 31 and 50 cm 2  mg -1 and 3.9-5.7 mg C -1  m -1 respectively), humic-like CDOM of high molecular weight (as indicated by abs 254/365 which ranged from 3.8 to 4.3). In contrast, circumneutral waters were dominated by fulvic-like CDOM of lower aromaticity (SAC 340 : 7-21 cm 2  mg -1 and SUVA 254 : 1.5-3.0 mg C -1  m -1 ) and lower molecular weight (abs 254/365 5.1-9.3). The groundwater-fed site had a higher abundance of protein-like CDOM, which was the least aromatic (SAC 340 : 2-5 cm 2  mg -1 and SUVA 254 : 0.58-1.1 mg C -1  m -1 ). CDOM was generally less aromatic, of a lower molecular weight and more autochthonous in nature during the summer/autumn sampling compared to winter/spring. Significant

Mediation analysis with time varying exposures and mediators.

Science.gov (United States)

VanderWeele, Tyler J; Tchetgen Tchetgen, Eric J

2017-06-01

In this paper we consider causal mediation analysis when exposures and mediators vary over time. We give non-parametric identification results, discuss parametric implementation, and also provide a weighting approach to direct and indirect effects based on combining the results of two marginal structural models. We also discuss how our results give rise to a causal interpretation of the effect estimates produced from longitudinal structural equation models. When there are time-varying confounders affected by prior exposure and mediator, natural direct and indirect effects are not identified. However, we define a randomized interventional analogue of natural direct and indirect effects that are identified in this setting. The formula that identifies these effects we refer to as the "mediational g-formula." When there is no mediation, the mediational g-formula reduces to Robins' regular g-formula for longitudinal data. When there are no time-varying confounders affected by prior exposure and mediator values, then the mediational g-formula reduces to a longitudinal version of Pearl's mediation formula. However, the mediational g-formula itself can accommodate both mediation and time-varying confounders and constitutes a general approach to mediation analysis with time-varying exposures and mediators.

Robust metabolic responses to varied carbon sources in natural and laboratory strains of Saccharomyces cerevisiae.

Directory of Open Access Journals (Sweden)

Wayne A Van Voorhies

Full Text Available Understanding factors that regulate the metabolism and growth of an organism is of fundamental biologic interest. This study compared the influence of two different carbon substrates, dextrose and galactose, on the metabolic and growth rates of the yeast Saccharomyces cerevisiae. Yeast metabolic and growth rates varied widely depending on the metabolic substrate supplied. The metabolic and growth rates of a yeast strain maintained under long-term laboratory conditions was compared to strain isolated from natural condition when grown on different substrates. Previous studies had determined that there are numerous genetic differences between these two strains. However, the overall metabolic and growth rates of a wild isolate of yeast was very similar to that of a strain that had been maintained under laboratory conditions for many decades. This indicates that, at in least this case, metabolism and growth appear to be well buffered against genetic differences. Metabolic rate and cell number did not co-vary in a simple linear manner. When grown in either dextrose or galactose, both strains showed a growth pattern in which the number of cells continued to increase well after the metabolic rate began a sharp decline. Previous studied have reported that O₂ consumption in S. cerevisiae grown in reduced dextrose levels were elevated compared to higher levels. Low dextrose levels have been proposed to induce caloric restriction and increase life span in yeast. However, there was no evidence that reduced levels of dextrose increased metabolic rates, measured by either O₂ consumption or CO₂ production, in the strains used in this study.

The effect of varying implant position in immediately loaded implant-supported mandibular overdentures.

Science.gov (United States)

Shaarawy, Mohammed A; Aboelross, Ehab M

2013-06-01

This study was carried out to evaluate the effect of varying implant position in immediately loaded implant-supported mandibular overdentures on peri-implant bone density, muscle activity, and patient satisfaction. Fourteen completely edentulous patients were selected for the study. After complete denture construction, patients were divided into 2 equal groups. Four dental implants were installed bilaterally in the interforaminal region in the first group, while in the second group, 4 dental implants were inserted bilaterally: 2 in the interforaminal region and 2 in the first molar area. Immediately after suturing, telescopic abutments were screwed to the implants, and the retaining caps were picked up into the fitting surface of the lower denture, which was delivered to the patient. Patients were recalled for radiographic bone density evaluation just after denture delivery and then at 3, 6, and 12 months thereafter. Muscle activities of masseter and temporalis muscles as well as patient satisfaction were also evaluated. The results of the study showed a high success rate approximating 98.2% of the immediately loaded implants. The electromyographic (EMG) records of both muscles in group 1 were significantly higher during chewing hard food after 3 months compared with group 2 (P overdentures through posterior placement beyond the interforaminal area results in a favorable response in terms of increased peri-implant bone density as well as decreased EMG activity of masseter and temporalis muscles.

The illusion of the positive: the impact of natural and induced mood on older adults' false recall.

Science.gov (United States)

Emery, Lisa; Hess, Thomas M; Elliot, Tonya

2012-11-01

Recent research suggests that affective and motivational processes can influence age differences in memory. In the current study, we examine the impact of both natural and induced mood state on age differences in false recall. Older and younger adults performed a version of the Deese-Roediger-McDermott (DRM; Roediger & McDermott, 1995 , Journal of Experimental Psychology: Learning, Memory, and Cognition, 21, 803) false memory paradigm in either their natural mood state or after a positive or negative mood induction. Results indicated that, after accounting for age differences in basic cognitive function, age-related differences in positive mood during the testing session were related to increased false recall in older adults. Inducing older adults into a positive mood also exacerbated age differences in false memory. In contrast, veridical recall did not appear to be systematically influenced by mood. Together, these results suggest that positive mood states can impact older adults' information processing and potentially increase underlying cognitive age differences.

Simple technique to achieve a natural position of the head for cone beam computed tomography

NARCIS (Netherlands)

Damstra, Janalt; Fourie, Zacharias; Ren, Yijin

We developed a modified laser level technique to record the natural position of the head in all three planes of space. This is a simple method for use with three-dimensional images and may be valuable in routine craniofacial assessment.

Probing background ionization: positive streamers with varying pulse repetition rate and with a radioactive admixture

International Nuclear Information System (INIS)

Nijdam, S; Van Veldhuizen, E M; Ebert, U; Wormeester, G

2011-01-01

Positive streamers need a source of free electrons ahead of them to propagate. A streamer can supply these electrons by itself through photo-ionization, or the electrons can be present due to external background ionization. Here we investigate the effects of background ionization on streamer propagation and morphology by changing the gas composition and the repetition rate of the voltage pulses, and by adding a small amount of radioactive 85 Kr. We find that the general morphology of a positive streamer discharge in high-purity nitrogen depends on background ionization: at lower background ionization levels the streamers branch more and have a more feather-like appearance. This is observed both when varying the repetition rate and when adding 85 Kr, though side branches are longer with the radioactive admixture. But velocities and minimal diameters of streamers are virtually independent of the background ionization level. In air, the inception cloud breaks up into streamers at a smaller radius when the repetition rate and therefore the background ionization level is higher. When measuring the effects of the pulse repetition rate and of the radioactive admixture on the discharge morphology, we found that our estimates of background ionization levels are consistent with these observations; this gives confidence in the estimates. Streamer channels generally do not follow the paths of previous discharge channels for repetition rates of up to 10 Hz. We estimate the effect of recombination and diffusion of ions and free electrons from the previous discharge and conclude that the old trail has largely disappeared at the moment of the next voltage pulse; therefore the next streamers indeed cannot follow the old trail.

Methods of natural gas liquefaction and natural gas liquefaction plants utilizing multiple and varying gas streams

Science.gov (United States)

Wilding, Bruce M; Turner, Terry D

2014-12-02

A method of natural gas liquefaction may include cooling a gaseous NG process stream to form a liquid NG process stream. The method may further include directing the first tail gas stream out of a plant at a first pressure and directing a second tail gas stream out of the plant at a second pressure. An additional method of natural gas liquefaction may include separating CO.sub.2 from a liquid NG process stream and processing the CO.sub.2 to provide a CO.sub.2 product stream. Another method of natural gas liquefaction may include combining a marginal gaseous NG process stream with a secondary substantially pure NG stream to provide an improved gaseous NG process stream. Additionally, a NG liquefaction plant may include a first tail gas outlet, and at least a second tail gas outlet, the at least a second tail gas outlet separate from the first tail gas outlet.

Positives and pathologies of natural resource management on private land-conservation areas.

Science.gov (United States)

Clements, Hayley S; Cumming, Graeme S

2017-06-01

In managed natural resource systems, such as fisheries and rangelands, there is a recognized trade-off between managing for short-term benefits and managing for longer term resilience. Management actions that stabilize ecological attributes or processes can improve productivity in the supply of ecosystem goods and services in the short term but erode system resilience at longer time scales. For example, fire suppression in rangelands can increase grass biomass initially but ultimately result in an undesirable, shrub-dominated system. Analyses of this phenomenon have focused largely on how management actions influence slow-changing biophysical system attributes (such as vegetation composition). Data on the frequency of management actions that reduce natural ecological variation on 66 private land-conservation areas (PLCAs) in South Africa were used to investigate how management actions are influenced by manager decision-making approaches, a largely ignored part of the problem. The pathology of natural resource management was evident on some PLCAs: increased focus on revenue-generation in decision making resulted in an increased frequency of actions to stabilize short-term variation in large mammal populations, which led to increased revenues from ecotourism or hunting. On many PLCAs, these management actions corresponded with a reduced focus on ecological monitoring and an increase in overstocking of game (i.e., ungulate species) and stocking of extralimitals (i.e., game species outside their historical range). Positives in natural resource management also existed. Some managers monitored slower changing ecological attributes, which resulted in less-intensive management, fewer extralimital species, and lower stocking rates. Our unique, empirical investigation of monitoring-management relationships illustrates that management decisions informed by revenue monitoring versus ecological monitoring can have opposing consequences for natural resource productivity and

Specimen loading list for the varying temperature experiment

International Nuclear Information System (INIS)

Qualls, A.L.; Sitterson, R.G.

1998-01-01

The varying temperature experiment HFIR-RB-13J has been assembled and inserted in the reactor. Approximately 5300 specimens were cleaned, inspected, matched, and loaded into four specimen holders. A listing of each specimen loaded into the steady temperature holder, its position in the capsule, and the identification of the corresponding specimen loaded into the varying temperature holder is presented in this report

Carbon storage potential in size–density fractions from semi-natural grassland ecosystems with different productivities over varying soil depths

International Nuclear Information System (INIS)

Breulmann, Marc; Boettger, Tatjana; Buscot, François; Gruendling, Ralf; Schulz, Elke

2016-01-01

Researchers have increasingly recognised a profound need for more information on SOC stocks in the soil and the factors governing their stability and dynamics. Many questions still remain unanswered about the interplay between changes in plant communities and the extent to which changes in aboveground productivity affect the carbon dynamics in soils through changes in its quantity and quality. Therefore, the main aim of this research was to examine the SOC accumulation potential of semi-natural grasslands of different productivities and determine the distribution of SOM fractions over varying soil depth intervals (0–10, 10–20, 20–30 30–50 50–80 and 80 + cm). SOM fractionation was considered as a relative measure of stability to separate SOM associated with clay minerals from SOM of specific light densities less than 2 g cm"−"3 (size-density fractionation). Two clay-associated fractions (CF1, < 1 μm; and CF2, 1–2 μm) and two light fractions (LF1, < 1.8 g cm"−"3; and LF2, 1.8–2.0 g cm"−"3) were separated. The stability of these fractions was characterised by their carbon hot water extractability (C_H_W_E) and stable carbon isotope composition. In the semi-natural grasslands studied, most OC was stored in the top 30 cm, where turnover is rapid. Effects of low productivity grasslands became only significantly apparent when fractional OC contributions of total SOM was considered (CF1 and LF1). In deeper soil depths OC was largely attributed to the CF1 fraction of low productivity grasslands. We suggest that the majority of OM in deeper soil depth intervals is microbially-derived, as evidenced by decreasing C/N ratios and decreasing δ"1"3C values. The hot water extraction and natural δ"1"3C abundance, employed here allowed the characterisation of SOM stabilisation properties, however how climatic changes affect the fate of OM within different soil depth intervals is still unknown. - Highlights: • OC stocks over varying soil depths in extensively

Carbon storage potential in size–density fractions from semi-natural grassland ecosystems with different productivities over varying soil depths

Energy Technology Data Exchange (ETDEWEB)

Breulmann, Marc [Helmholtz-Centre for Environmental Research – UFZ, Department of Soil Ecology, Theodor-Lieser-Str. 4, 06120 Halle (Germany); Helmholtz-Centre for Environmental Research – UFZ, Environmental and Biotechnology Centre (UBZ), Permoserstraße 15, 04318 Leipzig (Germany); Boettger, Tatjana [Helmholtz-Centre for Environmental Research – UFZ, Department of Isotope Hydrology, Theodor-Lieser-Str. 4, D-06120 Halle (Germany); Buscot, François [Helmholtz-Centre for Environmental Research – UFZ, Department of Soil Ecology, Theodor-Lieser-Str. 4, 06120 Halle (Germany); German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig (Germany); Gruendling, Ralf [Helmholtz-Centre for Environmental Research – UFZ, Department, Department of Soil Physics, Theodor-Lieser-Str. 4, D-06120 Halle (Germany); Schulz, Elke [Helmholtz-Centre for Environmental Research – UFZ, Department of Soil Ecology, Theodor-Lieser-Str. 4, 06120 Halle (Germany)

2016-03-01

Researchers have increasingly recognised a profound need for more information on SOC stocks in the soil and the factors governing their stability and dynamics. Many questions still remain unanswered about the interplay between changes in plant communities and the extent to which changes in aboveground productivity affect the carbon dynamics in soils through changes in its quantity and quality. Therefore, the main aim of this research was to examine the SOC accumulation potential of semi-natural grasslands of different productivities and determine the distribution of SOM fractions over varying soil depth intervals (0–10, 10–20, 20–30 30–50 50–80 and 80 + cm). SOM fractionation was considered as a relative measure of stability to separate SOM associated with clay minerals from SOM of specific light densities less than 2 g cm{sup −3} (size-density fractionation). Two clay-associated fractions (CF1, < 1 μm; and CF2, 1–2 μm) and two light fractions (LF1, < 1.8 g cm{sup −3}; and LF2, 1.8–2.0 g cm{sup −3}) were separated. The stability of these fractions was characterised by their carbon hot water extractability (C{sub HWE}) and stable carbon isotope composition. In the semi-natural grasslands studied, most OC was stored in the top 30 cm, where turnover is rapid. Effects of low productivity grasslands became only significantly apparent when fractional OC contributions of total SOM was considered (CF1 and LF1). In deeper soil depths OC was largely attributed to the CF1 fraction of low productivity grasslands. We suggest that the majority of OM in deeper soil depth intervals is microbially-derived, as evidenced by decreasing C/N ratios and decreasing δ{sup 13}C values. The hot water extraction and natural δ{sup 13}C abundance, employed here allowed the characterisation of SOM stabilisation properties, however how climatic changes affect the fate of OM within different soil depth intervals is still unknown. - Highlights: • OC stocks over varying

Time varying voltage combustion control and diagnostics sensor

Science.gov (United States)

Chorpening, Benjamin T [Morgantown, WV; Thornton, Jimmy D [Morgantown, WV; Huckaby, E David [Morgantown, WV; Fincham, William [Fairmont, WV

2011-04-19

A time-varying voltage is applied to an electrode, or a pair of electrodes, of a sensor installed in a fuel nozzle disposed adjacent the combustion zone of a continuous combustion system, such as of the gas turbine engine type. The time-varying voltage induces a time-varying current in the flame which is measured and used to determine flame capacitance using AC electrical circuit analysis. Flame capacitance is used to accurately determine the position of the flame from the sensor and the fuel/air ratio. The fuel and/or air flow rate (s) is/are then adjusted to provide reduced flame instability problems such as flashback, combustion dynamics and lean blowout, as well as reduced emissions. The time-varying voltage may be an alternating voltage and the time-varying current may be an alternating current.

Effects of Varying RedoxConditions on Natural Attenuation of Inorganic Contaminants from the D-Area Coal Pile Runoff Basin (U)

Energy Technology Data Exchange (ETDEWEB)

Kaplan, D

2004-05-30

The objective of this study was to provide geochemical parameters to characterize the D-Area Coal Pile Runoff Basin (DCPRB) sediment as a potential source term. It is anticipated that the measured values will be used in risk calculations and will provide additional technical support for imposing Monitored Natural Attenuation at D-Area. This study provides a detailed evaluation of the DCPRB sediment and is part of another study that quantified the Monitored Natural Attenuation of inorganic contaminants more broadly at the D-Area Expanded Operable Unit, which includes the DCPRB (Powell et al. 2004). Distribution coefficients (K{sub d} values; a solid to liquid contaminant concentration ratio) and the Potentially Leachable Fraction (the percent of the total contaminant concentration in the sediment that can likely contribute to a contaminant plume) were measured in a DCPRB sediment as a function of redox conditions. Redox conditions at the DCPRB are expected to vary greatly as the system undergoes varying drying and flooding conditions. Conservative values; K{sub d} values that err on the side of being too low and Potentially Leachable Fraction values that err on the side of being too high, are presented. The K{sub d} values are high compared to conservative literature values, and underscores the importance of measuring site-specific values to provide estimates of sediments natural attenuation/sorption capacities. The Potentially Leachable Fraction indicates that as little as 27% of the As, but all of the Cu and Tl will be part of the source term. In the case of the As, the remaining 83% will likely never leach out of the sediment, thereby providing a form of natural attenuation. Importantly, Be, Cr, Cu, Ni, and V concentrations in the sediment were less-than twice background levels, indicating this sediment was not a potential source for these contaminants. K{sub d} values generally increased significantly (As, Cd, Co, Cr, Cu, Ni, Se, and Tl) when the sediment was

Does accessibility of positive and negative schema vary by child physical abuse risk?

Science.gov (United States)

Crouch, Julie L; Risser, Heather J; Skowronski, John J; Milner, Joel S; Farc, Magdalena M; Irwin, Lauren M

2010-11-01

To examine differences in accessibility of positive and negative schema in parents with high and low risk for child physical abuse (CPA). This study combined picture priming and lexical decision making methods to assess the accessibility of positive and negative words following presentation of child and adult faces. The child and adult faces depicted positive, ambiguous, and negative affective valences. The sample included 67 (51 low and 16 high CPA risk) general population parents. CPA risk status was associated with accessibility of positive/negative words only following priming with faces of the opposite affective valence. More specifically, high CPA risk parents were slower to respond to positive (negative) words following priming with negative (positive) faces. Exploratory analyses indicated that this pattern of findings was more clearly apparent when picture primes involved adult faces. The present findings suggest that high and low CPA risk parents differ in how they process affectively incongruent information. Research is needed to further examine schema accessibility, as well as to examine whether processes involved in attention and affect integration play a role in CPA risk. Copyright © 2010 Elsevier Ltd. All rights reserved.

Time-varying Concurrent Risk of Extreme Droughts and Heatwaves in California

Science.gov (United States)

Sarhadi, A.; Diffenbaugh, N. S.; Ausin, M. C.

2016-12-01

Anthropogenic global warming has changed the nature and the risk of extreme climate phenomena such as droughts and heatwaves. The concurrent of these nature-changing climatic extremes may result in intensifying undesirable consequences in terms of human health and destructive effects in water resources. The present study assesses the risk of concurrent extreme droughts and heatwaves under dynamic nonstationary conditions arising from climate change in California. For doing so, a generalized fully Bayesian time-varying multivariate risk framework is proposed evolving through time under dynamic human-induced environment. In this methodology, an extreme, Bayesian, dynamic copula (Gumbel) is developed to model the time-varying dependence structure between the two different climate extremes. The time-varying extreme marginals are previously modeled using a Generalized Extreme Value (GEV) distribution. Bayesian Markov Chain Monte Carlo (MCMC) inference is integrated to estimate parameters of the nonstationary marginals and copula using a Gibbs sampling method. Modelled marginals and copula are then used to develop a fully Bayesian, time-varying joint return period concept for the estimation of concurrent risk. Here we argue that climate change has increased the chance of concurrent droughts and heatwaves over decades in California. It is also demonstrated that a time-varying multivariate perspective should be incorporated to assess realistic concurrent risk of the extremes for water resources planning and management in a changing climate in this area. The proposed generalized methodology can be applied for other stochastic nature-changing compound climate extremes that are under the influence of climate change.

Positive health effects of the natural outdoor environment in typical populations in different regions in Europe (PHENOTYPE): a study programme protocol

NARCIS (Netherlands)

Nieuwenhuijsen, M.J.; Kruize, H.; Gidlow, C.; Andrusaityte, S.; Anto, J.M.; Basagana, X.; Cirach, M.; Dadvand, P.; Danileviciute, A.; Donaire-Gonzalez, D.; Garcia, J.; Jerrett, M.; Jones, M.; Julvez, J.; van Kempen, E.; van Kamp, I.; Maas, J.; Seto, E.; Smith, G.; Triguero, M.; Wendel-Vos, W.; Wright, J.; Zufferey, J.; van den Hazel, P.J.; Lawrence, R.; Grazuleviciene, R.

2014-01-01

Introduction: Growing evidence suggests that close contact with nature brings benefits to human health and well-being, but the proposed mechanisms are still not well understood and the associations with health remain uncertain. The Positive Health Effects of the Natural Outdoor environment in

Antimicrobial Activity of Carbon Nanoparticles Isolated from Natural Sources against Pathogenic Gram-Negative and Gram-Positive Bacteria

International Nuclear Information System (INIS)

Varghese, S.; Jose, S.; Varghese, S.; Kuriakose, S.; Jose, S.

2013-01-01

This paper describes the isolation of carbon nanoparticles (CNPs) from kitchen soot, characterization of the CNPs by UV/visible spectroscopy, SEM and XRD, and their antimicrobial action. The antibacterial activity of the isolated carbon nanoparticles was tested against various pathogenic bacterial strains such as Gram-negative Proteus refrigere and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus and Streptococcus haemolyticus. The inhibition zones were measured, and it was found that the carbon nanoparticles isolated from natural sources are active against these Gram-negative and Gram-positive bacterial strains

Influence of varying diets on radiosensitivity of quinea pigs

International Nuclear Information System (INIS)

Darenskaya, N.G.; Kuznetsova, S.S.; Lebengarts, Ya.Z.

1975-01-01

Seven groups of 25-day-old Guinea pig males given different diets during the entire observation period. Six groups received full-ration granulated mixed food varying in the contents of protein and cellulose, while the seventh group ate natural food. Experiments with irradiation failed to reveal any essential differences in radiosensitivity of animals grown on natural and mixed food, which enabled us to propose full-ration granulated mixed food for feeding laboratory guinea pigs

Influence of varying diets on radiosensitivity of quinea pigs

Energy Technology Data Exchange (ETDEWEB)

Darenskaya, N G; Kuznetsova, S S; Lebengarts, Ya Z

1975-07-01

Seven groups of 25-day-old Guinea pig males given different diets during the entire observation period. Six groups received full-ration granulated mixed food varying in the contents of protein and cellulose, while the seventh group ate natural food. Experiments with irradiation failed to reveal any essential differences in radiosensitivity of animals grown on natural and mixed food, which enabled us to propose full-ration granulated mixed food for feeding laboratory guinea pigs.

Entropy Rate of Time-Varying Wireless Networks

DEFF Research Database (Denmark)

Cika, Arta; Badiu, Mihai Alin; Coon, Justin P.

2018-01-01

In this paper, we present a detailed framework to analyze the evolution of the random topology of a time-varying wireless network via the information theoretic notion of entropy rate. We consider a propagation channel varying over time with random node positions in a closed space and Rayleigh...... fading affecting the connections between nodes. The existence of an edge between two nodes at given locations is modeled by a Markov chain, enabling memory effects in network dynamics. We then derive a lower and an upper bound on the entropy rate of the spatiotemporal network. The entropy rate measures...

Positive natural resource shocks and domestic adjustments in a semi-industrialized economy: Argentina in the 2004-2007 period

NARCIS (Netherlands)

L.A. Serino (Leandro)

2009-01-01

textabstractThis paper evaluates the domestic adjustment to recent positive external shocks in Argentina's natural resource sectors. Although there is no single, exclusive determinant of Argentina's fast economic growth in the period 2003-2007, the paper illustrates the favourable contribution of

Does Accessibility of Positive and Negative Schema Vary by Child Physical Abuse Risk?

Science.gov (United States)

Crouch, Julie L.; Risser, Heather J.; Skowronski, John J.; Milner, Joel S.; Farc, Magdalena M.; Irwin, Lauren M.

2010-01-01

Objective: To examine differences in accessibility of positive and negative schema in parents with high and low risk for child physical abuse (CPA). Methods: This study combined picture priming and lexical decision making methods to assess the accessibility of positive and negative words following presentation of child and adult faces. The child…

The natural history of HIV infection

DEFF Research Database (Denmark)

Sabin, C.A.; Lundgren, J.D.

2013-01-01

PURPOSE OF REVIEW: To review recent published literature around three areas: long-term nonprogression/viral control; predictors of viral load set point/disease progression; and the potential impact of antiretroviral therapy (ART) in early HIV infection. RECENT FINDINGS: The natural course...... of untreated HIV infection varies widely with some HIV-positive individuals able to maintain high CD4 cell counts and/or suppressed viral load in the absence of ART. Although similar, the underlying mechanistic processes leading to long-term nonprogression and viral control are likely to differ. Concerted...... the immunological deterioration which would otherwise be seen in untreated HIV infection, recent studies do not address the longer term clinical benefits of ART at this very early stage. SUMMARY: A better understanding of the relative influences of viral, host, and environmental factors on the natural course of HIV...

Electromagnetic radiation in a time-varying background medium

NARCIS (Netherlands)

Budko, N.V.

2009-01-01

Analytical solutions are presented for the electromagnetic radiation by an arbitrary pulsed source into a homogeneous time-varying background medium. In the constant-impedance case an explicit radiation formula is obtained for the synchronous permittivity and permeability described by any positive

Turkey's natural gas necessity, consumption and future perspectives

International Nuclear Information System (INIS)

Kilic, A.M.

2006-01-01

Turkey is an important candidate to be the 'energy corridor' in the transmission of the abundant oil and natural gas resources of the Middle East and Middle Asia countries to the Western market. Furthermore, Turkey is planning to increase its oil and gas pipeline infrastructure to accommodate its increased energy consumption. Naturally, Turkish natural gas usage is projected to increase remarkably in coming years, with the prime consumers, expected to be industry and power plants. Energy demand of Turkey is growing by 8% annually, one of the highest rates in the world. In addition, natural gas consumption is the fastest growing primary energy source in Turkey. Gas sales started at 0.5 bcm (billion cubic meters), in 1987 and reached approximately 22 bcm in 2003. This article deals with energy policies and natural gas consumption of Turkey. Besides modernization of present lines and realization of capacity increase, new lines will also be needed. In this context, Turkey, due to its geographical location is, in an important position to vary European supply. Therefore, Turkey's role as a transitory area gains importance

Navigation performance in virtual environments varies with fractal dimension of landscape

OpenAIRE

Juliani, Arthur W.; Bies, Alexander J.; Boydston, Cooper R.; Taylor, Richard P.; Sereno, Margaret E.

2016-01-01

Fractal geometry has been used to describe natural and built environments, but has yet to be studied in navigational research. In order to establish a relationship between the fractal dimension (D) of a natural environment and humans’ ability to navigate such spaces, we conducted two experiments using virtual environments that simulate the fractal properties of nature. In Experiment 1, participants completed a goal-driven search task either with or without a map in landscapes that varied in D...

Mother natural: Motivations and associations for consuming natural foods.

Science.gov (United States)

Moscato, Emily M; Machin, Jane E

2018-02-01

Natural is perceived as innately positive and is a widely sought-after attribute in food products. The natural food industry continues to grow in response to rising consumer demand. This qualitative study explored mothers' motivations for purchasing and consuming natural food products for themselves and their families. Mothers are an important population because of their disproportionate influence on household food consumption. We employed participant photography and a series of three weekly focus groups to derive a rich understanding of the activities surrounding and motivations behind seeking natural in everyday buying decisions. Five major themes were identified. First, natural nurtures well-being: physical, psychological, social, and emotional health. Second, natural behaves "supernaturally," allowing positive attributes to be transmitted from the source to the recipient. Third, natural is associated with authenticity, providing a sense of trust, transparency, and control. Fourth, consuming natural reinforces the socially constructed idea of a good mother. Lastly, the preference for natural does not always translate into purchase; mothers face compromises because of conflicting priorities and resources. Understanding mothers' multiple motivations provides deeper insight into the attraction for natural products. The findings have application in positioning interventions for more nutritional eating and revising regulations on the food label natural. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural products used for diabetes.

Science.gov (United States)

Shapiro, Karen; Gong, William C

2002-01-01

To review the efficacy and safety of natural products commonly used for diabetes. English and Spanish-language journals retrieved through a MEDLINE search of articles published between 1960 and December 2001 using these index terms: Opuntia, karela, gymnema, tecoma, alpha lipoic acid, thioctic acid, ginseng, panaxans, and diabetes. Natural products have long been used in traditional systems of medicine for diabetes. Products in common use include nopal (prickly pear cactus), fenu-greek, karela (bitter melon), gymnema, ginseng, tronadora, chromium, and alpha-lipoic acid. The popularity of these products varies among people of different ethnicities. Nopal is the most commonly used herbal hypoglycemic among persons of Mexican descent. Karela is more commonly used by persons from Asian countries. Some of these agents have gained universal appeal. For a select number of products, studies have revealed single or multiple mechanisms of action. For several of these, high soluble fiber content is a contributing factor. Based on the available evidence, several natural products in common use can lower blood glucose in patients with diabetes. Commonly used natural products often have a long history of traditional use, and pharmacists who have a stronger understanding of these products are better positioned to counsel patients on their appropriate use.

Natural organic matter removal by ion exchange at different positions in the drinking water treatment lane

Directory of Open Access Journals (Sweden)

A. Grefte

2013-01-01

Full Text Available To guarantee a good water quality at the customers tap, natural organic matter (NOM should be (partly removed during drinking water treatment. The objective of this research was to improve the biological stability of the produced water by incorporating anion exchange (IEX for NOM removal. Different placement positions of IEX in the treatment lane (IEX positioned before coagulation, before ozonation or after slow sand filtration and two IEX configurations (MIEX® and fluidized IEX (FIX were compared on water quality as well as costs. For this purpose the pre-treatment plant at Loenderveen and production plant Weesperkarspel of Waternet were used as a case study. Both, MIEX® and FIX were able to remove NOM (mainly the HS fraction to a high extent. NOM removal can be done efficiently before ozonation and after slow sand filtration. The biological stability, in terms of assimilable organic carbon, biofilm formation rate and dissolved organic carbon, was improved by incorporating IEX for NOM removal. The operational costs were assumed to be directly dependent of the NOM removal rate and determined the difference between the IEX positions. The total costs for IEX for the three positions were approximately equal (0.0631 € m−3, however the savings on following treatment processes caused a cost reduction for the IEX positions before coagulation and before ozonation compared to IEX positioned after slow sand filtration. IEX positioned before ozonation was most cost effective and improved the biological stability of the treated water.

Naturalness and image quality : saturation and lightness variation in color images of natural scenes

NARCIS (Netherlands)

Ridder, de H.

1996-01-01

The relation between perceived image quality and naturalness was investigated by varying the colorfulness of natural images at various lightness levels. At each lightness level, subjects assessed perceived colorfulness, naturalness, and quality as a function of average saturation by means of direct

Automatic Detection and Reproduction of Natural Head Position in Stereo-Photogrammetry.

Science.gov (United States)

Hsung, Tai-Chiu; Lo, John; Li, Tik-Shun; Cheung, Lim-Kwong

2015-01-01

The aim of this study was to develop an automatic orientation calibration and reproduction method for recording the natural head position (NHP) in stereo-photogrammetry (SP). A board was used as the physical reference carrier for true verticals and NHP alignment mirror orientation. Orientation axes were detected and saved from the digital mesh model of the board. They were used for correcting the pitch, roll and yaw angles of the subsequent captures of patients' facial surfaces, which were obtained without any markings or sensors attached onto the patient. We tested the proposed method on two commercial active (3dMD) and passive (DI3D) SP devices. The reliability of the pitch, roll and yaw for the board placement were within ±0.039904°, ±0.081623°, and ±0.062320°; where standard deviations were 0.020234°, 0.045645° and 0.027211° respectively. Orientation-calibrated stereo-photogrammetry is the most accurate method (angulation deviation within ±0.1°) reported for complete NHP recording with insignificant clinical error.

Cross-cultural patterns in dynamic ratings of positive and negative natural emotional behaviour.

Science.gov (United States)

Sneddon, Ian; McKeown, Gary; McRorie, Margaret; Vukicevic, Tijana

2011-02-18

Studies of cross-cultural variations in the perception of emotion have typically compared rates of recognition of static posed stimulus photographs. That research has provided evidence for universality in the recognition of a range of emotions but also for some systematic cross-cultural variation in the interpretation of emotional expression. However, questions remain about how widely such findings can be generalised to real life emotional situations. The present study provides the first evidence that the previously reported interplay between universal and cultural influences extends to ratings of natural, dynamic emotional stimuli. Participants from Northern Ireland, Serbia, Guatemala and Peru used a computer based tool to continuously rate the strength of positive and negative emotion being displayed in twelve short video sequences by people from the United Kingdom engaged in emotional conversations. Generalized additive mixed models were developed to assess the differences in perception of emotion between countries and sexes. Our results indicate that the temporal pattern of ratings is similar across cultures for a range of emotions and social contexts. However, there are systematic differences in intensity ratings between the countries, with participants from Northern Ireland making the most extreme ratings in the majority of the clips. The results indicate that there is strong agreement across cultures in the valence and patterns of ratings of natural emotional situations but that participants from different cultures show systematic variation in the intensity with which they rate emotion. Results are discussed in terms of both 'in-group advantage' and 'display rules' approaches. This study indicates that examples of natural spontaneous emotional behaviour can be used to study cross-cultural variations in the perception of emotion.

Cross-cultural patterns in dynamic ratings of positive and negative natural emotional behaviour.

Directory of Open Access Journals (Sweden)

Ian Sneddon

2011-02-01

Full Text Available Studies of cross-cultural variations in the perception of emotion have typically compared rates of recognition of static posed stimulus photographs. That research has provided evidence for universality in the recognition of a range of emotions but also for some systematic cross-cultural variation in the interpretation of emotional expression. However, questions remain about how widely such findings can be generalised to real life emotional situations. The present study provides the first evidence that the previously reported interplay between universal and cultural influences extends to ratings of natural, dynamic emotional stimuli.Participants from Northern Ireland, Serbia, Guatemala and Peru used a computer based tool to continuously rate the strength of positive and negative emotion being displayed in twelve short video sequences by people from the United Kingdom engaged in emotional conversations. Generalized additive mixed models were developed to assess the differences in perception of emotion between countries and sexes. Our results indicate that the temporal pattern of ratings is similar across cultures for a range of emotions and social contexts. However, there are systematic differences in intensity ratings between the countries, with participants from Northern Ireland making the most extreme ratings in the majority of the clips.The results indicate that there is strong agreement across cultures in the valence and patterns of ratings of natural emotional situations but that participants from different cultures show systematic variation in the intensity with which they rate emotion. Results are discussed in terms of both 'in-group advantage' and 'display rules' approaches. This study indicates that examples of natural spontaneous emotional behaviour can be used to study cross-cultural variations in the perception of emotion.

Modelling and Control of Ionic Electroactive Polymer Actuators under Varying Humidity Conditions

Directory of Open Access Journals (Sweden)

S. Sunjai Nakshatharan

2018-02-01

Full Text Available In this work, we address the problem of position control of ionic electroactive polymer soft actuators under varying relative humidity conditions. The impact of humidity on the actuation performance of ionic actuators is studied through frequency response and impedance spectroscopy analysis. Considering the uncertain performance of the actuator under varying humidity conditions, an adaptable model using the neural network method is developed. The model uses relative humidity magnitude as one of the model parameters, making it robust to different environmental conditions. Utilizing the model, a closed-loop controller based on the model predictive controller is developed for position control of the actuator. The developed model and controller are experimentally verified and found to be capable of predicting and controlling the actuators with excellent tracking accuracy under relative humidity conditions varying in the range of 10–90%.

A clinical technique for virtual articulator mounting with natural head position by using calibrated stereophotogrammetry.

Science.gov (United States)

Lam, Walter Y H; Hsung, Richard T C; Choi, Winnie W S; Luk, Henry W K; Cheng, Leo Y Y; Pow, Edmond H N

2017-09-29

Accurate articulator-mounted casts are essential for occlusion analysis and for fabrication of dental prostheses. Although the axis orbital plane has been commonly used as the reference horizontal plane, some clinicians prefer to register the horizontal plane with a spirit level when the patient is in the natural head position (NHP) to avoid anatomic landmark variations. This article presents a digital workflow for registering the patient's horizontal plane in NHP on a virtual articulator. An orientation reference board is used to calibrate a stereophotogrammetry device and a 3-dimensional facial photograph with the patient in NHP. The horizontal plane can then be automatically registered to the patient's virtual model and aligned to the virtual articulator at the transverse horizontal axis level. This technique showed good repeatability with positional differences of less than 1 degree and 1 mm in 5 repeated measurements in 1 patient. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Strengthening Canada's position in the North American natural gas market

International Nuclear Information System (INIS)

2001-09-01

The Canadian Gas Association (CGA) is the industry organization that represents the Canadian natural gas and energy delivery industry. It is on the frontline of consumer perceptions regarding natural gas, which is the fuel of choice for Canadian homeowners. Canadian consumers have benefitted from the deregulation initiatives of the mid-1980s which provided significant growth opportunities. Given the tumultuous energy environment throughout North America, the CGA believes that a national energy strategy should be developed to address future supply issues and also to examine ways to ensure that extreme market shifts are anticipated and mitigated as much as possible. The CGA is ready to provide governments with input for such a strategy representing the perspective of the Canadian consumer. The CGA recommends that the Government of Canada, the provinces and territories adopt the following initiatives regarding the use of natural gas: (1) recognize and promote the environmental qualities and applications of natural gas, (2) encourage competition, (3) promote transparent and consistent approach to regulation, (4) reaffirm commitment to market-based policies, (5) facilitate economic research, analysis and communication about trends in the natural gas market, and (6) promote the development of new technologies that expand the uses of natural gas and support research in infrastructure development. The government's actions in the areas proposed in this report will contribute to advancing Canada's environmental objectives and economic growth. 2 figs

Nature and Age of Neighbours Matter: Interspecific Associations among Tree Species Exist and Vary across Life Stages in Tropical Forests.

Directory of Open Access Journals (Sweden)

Alicia Ledo

Full Text Available Detailed information about interspecific spatial associations among tropical tree species is scarce, and hence the ecological importance of those associations may have been underestimated. However, they can play a role in community assembly and species diversity maintenance. This study investigated the spatial dependence between pairs of species. First, the spatial associations (spatial attraction and spatial repulsion that arose between species were examined. Second, different sizes of trees were considered in order to evaluate whether the spatial relationships between species are constant or vary during the lifetime of individuals. Third, the consistency of those spatial associations with the species-habitat associations found in previous studies was assessed. Two different tropical ecosystems were investigated: a montane cloud forest and a lowland moist forest. The results showed that spatial associations among species exist, and these vary among life stages and species. The rarity of negative spatial interactions suggested that exclusive competition was not common in the studied forests. On the other hand, positive interactions were common, and the results of this study strongly suggested that habitat associations were not the only cause of spatial attraction among species. If this is true, habitat associations and density dependence are not the only mechanisms that explain species distribution and diversity; other ecological interactions, such as facilitation among species, may also play a role. These spatial associations could be important in the assembly of tropical tree communities and forest succession, and should be taken into account in future studies.

Position of the American Dietetic Association: dietetics professionals can implement practices to conserve natural resources and protect the environment. (Previously titled "natural resource conservation and waste management").

Science.gov (United States)

2001-10-01

It is the position of the American Dietetic Association to encourage environmentally responsible practices that conserve natural resources, minimize the quantity of waste that is generated, and have the least adverse affect on the health of all living organisms and the environment. All components of the food system, from farmer to consumer, are affected by the availability and cost of energy and the availability and quality of water. Outdoor and indoor air quality significantly impacts the health of all living organisms. Decisions that dietetics professionals make as practitioners and consumers can affect the quantity and type of solid waste generated. The demand for natural resources should be evaluated when selecting the most cost-effective, environmentally sensitive approach to the management of solid waste. Special precautions are needed when using and disposing of hazardous and medical waste to protect the safety of our clients and employees. This position paper provides information and resources for dietetics professionals for addressing the complexity of the environmental issue presented. Conservation strategies are identified that dietetics professionals can use in their worksites and at home. These conservation practices may reduce cost and decrease the environmental impact we have on our communities and the world.

A Novel Variant with Positive Natural Selection Influenced Hb A2 Levels in Chinese Individuals with β-Thalassemia.

Science.gov (United States)

Yu, Shanjuan; Chen, Yang; Lai, Ketong; Dewan, Roma Kajal; He, Yunyan

2017-05-01

β-Thalassemia (β-thal) is the most common inherited hemolytic anemia worldwide. Elevated Hb A 2 is a mark of β-thal carriers. The aim of this study was to identify the pathogenic variants associated with the Hb A 2 levels. One thousand and thirty β-thal carriers were recruited for this study. Using positive natural expression quantitative trait loci (eQTL) analysis, a significant variant was selected. Genotyping for the rs231841 polymorphism was performed by the Sequenom MassARRAY IPLEX platform. All genetic association analyses were performed with the PLINK program. The linear regression analysis showed that rs231841 in the intron region of the potassium voltage-gated channel subfamily Q member 1 (KCNQ1) gene on chromosome 11p15 was significantly associated with Hb A 2 levels. The presence of the C allele was associated with elevated Hb A 2 levels. Our results suggest that rs231841 on the KCNQ1 gene with positive natural selection is related to Hb A 2 levels in Chinese β-thal carriers, and KCNQ1 is probably associated with the expression of the β-like globin gene cluster.

Solitonic natural orbitals

Science.gov (United States)

Cioslowski, Jerzy

2018-04-01

The dependence of the natural amplitudes of the harmonium atom in its ground state on the confinement strength ω is thoroughly investigated. A combination of rigorous analysis and extensive, highly accurate numerical calculations reveals the presence of only one positive-valued natural amplitude ("the normal sign pattern") for all ω ≥1/2 . More importantly, it is shown that unusual, weakly occupied natural orbitals (NOs) corresponding to additional positive-valued natural amplitudes emerge upon sufficient weakening of the confinement. These solitonic NOs, whose shapes remain almost invariant as their radial positions drift toward infinity upon the critical values of ω being approached from below, exhibit strong radial localization. Their asymptotic properties are extracted from the numerical data and their relevance to calculations on fully Coulombic systems is discussed.

Naturalness and image quality : chroma and hue variation in color images of natural scenes

NARCIS (Netherlands)

Ridder, de H.; Blommaert, F.J.J.; Fedorovskaya, E.A.; Rogowitz, B.E.; Allebach, J.P.

1995-01-01

The relation between perceptual image quality and naturalness was investigated by varying the colorfulness and hue of color images of natural scenes. These variations were created by digitizing the images, subsequently determining their color point distributions in the CIELUV color space and finally

Naturalness and image quality: Chroma and hue variation in color images of natural scenes

NARCIS (Netherlands)

Ridder, de H.; Blommaert, F.J.J.; Fedorovskaya, E.A.; Eschbach, R.; Braun, K.

1997-01-01

The relation between perceptual image quality and natural ness was investigated by varying the colorfulness and hue of color images of natural scenes. These variations were created by digitizing the images, subsequently determining their color point distributions in the CIELUV color space and

Variable-Position Acoustic Levitation

Science.gov (United States)

Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

1983-01-01

Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

A reciprocal Wald theorem for varying gravitational function

International Nuclear Information System (INIS)

Fay, Stephane

2004-01-01

We study when a cosmological constant is a natural issue if it is mimicked by the potential of a massive Hyperextended Scalar Tensor theory with a perfect fluid for Bianchi type I and V models. We then deduce a reciprocal Wald theorem giving the conditions such that the potential tends to a non vanishing constant when the gravitational function varies. We also get the conditions allowing the potential to vanish or diverge. (orig.)

Positive mood broadens visual attention to positive stimuli.

Science.gov (United States)

Wadlinger, Heather A; Isaacowitz, Derek M

2006-03-01

In an attempt to investigate the impact of positive emotions on visual attention within the context of Fredrickson's (1998) broaden-and-build model, eye tracking was used in two studies to measure visual attentional preferences of college students (n=58, n=26) to emotional pictures. Half of each sample experienced induced positive mood immediately before viewing slides of three similarly-valenced images, in varying central-peripheral arrays. Attentional breadth was determined by measuring the percentage viewing time to peripheral images as well as by the number of visual saccades participants made per slide. Consistent with Fredrickson's theory, the first study showed that individuals induced into positive mood fixated more on peripheral stimuli than did control participants; however, this only held true for highly-valenced positive stimuli. Participants under induced positive mood also made more frequent saccades for slides of neutral and positive valence. A second study showed that these effects were not simply due to differences in emotional arousal between stimuli. Selective attentional broadening to positive stimuli may act both to facilitate later building of resources as well as to maintain current positive affective states.

Sound transmission in slowly varying circular and annular ducts with flow

NARCIS (Netherlands)

Rienstra, S.W.

1999-01-01

Sound transmission through straight circular ducts with a uniform inviscid mean flow and a constant acoustic lining (impedance wall) is classically described by a modal expansion. A natural extension for ducts with axially slowly varying properties (diameter and mean flow, wall impedance) is a

Buyer-Supplier Relationships and Power Position: Interchaining

Directory of Open Access Journals (Sweden)

Hebatollah Morsy

2017-02-01

Full Text Available According to several studies, power and interdependence play a considerable role in understanding the buyer–supplier relationships, yet, empirical research is still limited. Also, the nature of the buyer-supplier relationship and managing them might vary based on the power position of buyers and suppliers. Few studies focused on the reason behind this interrelation and strong influence of power on the buyer-supplier relationships. Thus, the purpose of this study is to gain better understanding and try to identify how power position and buyer-supplier relationships are interrelated, and whether there are common determinants and/or characteristics behind this strong bond between the two concepts. Both transaction cost analysis theory and social exchange theory were integrated in building the argument. Regarding the methodology, qualitative exploratory research design was employed by using multiple-case study as the main research method, where three multinational Egyptian organizations were selected. Moreover, data was collected using individual in-depth interviews, and analyzed through coding and cross case analysis techniques. The results showed that there are common factors that influence both buyer-supplier relationship characteristics and power position attributes. And according, the findings helped in pointing out a new lens of discussing and investigating the bond between buyer-supplier relationships ad power in research.

Dietary adaptation of FADS genes in Europe varied across time and geography.

Science.gov (United States)

Ye, Kaixiong; Gao, Feng; Wang, David; Bar-Yosef, Ofer; Keinan, Alon

2017-05-26

Fatty acid desaturase (FADS) genes encode rate-limiting enzymes for the biosynthesis of omega-6 and omega-3 long-chain polyunsaturated fatty acids (LCPUFAs). This biosynthesis is essential for individuals subsisting on LCPUFA-poor diets (for example, plant-based). Positive selection on FADS genes has been reported in multiple populations, but its cause and pattern in Europeans remain unknown. Here we demonstrate, using ancient and modern DNA, that positive selection acted on the same FADS variants both before and after the advent of farming in Europe, but on opposite (that is, alternative) alleles. Recent selection in farmers also varied geographically, with the strongest signal in southern Europe. These varying selection patterns concur with anthropological evidence of varying diets, and with the association of farming-adaptive alleles with higher FADS1 expression and thus enhanced LCPUFA biosynthesis. Genome-wide association studies reveal that farming-adaptive alleles not only increase LCPUFAs, but also affect other lipid levels and protect against several inflammatory diseases.

Moonshine: Diurnally varying hydration through natural distillation on the Moon, detected by the Lunar Exploration Neutron Detector (LEND).

Science.gov (United States)

Livengood, T A; Chin, G; Sagdeev, R Z; Mitrofanov, I G; Boynton, W V; Evans, L G; Litvak, M L; McClanahan, T P; Sanin, A B; Starr, R D; Su, J J

2015-07-15

The Lunar Exploration Neutron Detector (LEND), on the polar-orbiting Lunar Reconnaissance Orbiter (LRO) spacecraft, has detected suppression in the Moon's naturally-occurring epithermal neutron leakage flux that is consistent with the presence of diurnally varying quantities of hydrogen in the regolith near the equator. Peak hydrogen concentration (neutron flux suppression) is on the dayside of the dawn terminator and diminishes through the dawn-to-noon sector. The minimum concentration of hydrogen is in the late afternoon and dusk sector. The chemical form of hydrogen is not determinable from these measurements, but other remote sensing methods and anticipated elemental availability suggest water molecules or hydroxyl ions. Signal-to-noise ratio at maximum contrast is 5.6 σ in each of two detector systems. Volatiles are deduced to collect in or on the cold nightside surface and distill out of the regolith after dawn as rotation exposes the surface to sunlight. Liberated volatiles migrate away from the warm subsolar region toward the nearby cold nightside surface beyond the terminator, resulting in maximum concentration at the dawn terminator. The peak concentration within the upper ~1 m of regolith is estimated to be 0.0125 ± 0.0022 weight-percent water-equivalent hydrogen (wt% WEH) at dawn, yielding an accumulation of 190 ± 30 ml recoverable water per square meter of regolith at each dawn. Volatile transport over the lunar surface in opposition to the Moon's rotation exposes molecules to solar ultraviolet radiation. The short lifetime against photolysis and permanent loss of hydrogen from the Moon requires a resupply rate that greatly exceeds anticipated delivery of hydrogen by solar wind implantation or by meteoroid impacts, suggesting that the surface inventory must be continually resupplied by release from a deep volatile inventory in the Moon. The natural distillation of water from the regolith by sunlight and its capture on the cold night surface may

Turkey's natural gas necessity, consumption and future perspectives

Energy Technology Data Exchange (ETDEWEB)

Kilic, A.M. [Mining Engineering Department, Faculty of Engineering and Architecture, Cukurova University, 01330 Balcali, Adana (Turkey)]. E-mail: kilicm@cu.edu.tr

2006-09-15

Turkey is an important candidate to be the 'energy corridor' in the transmission of the abundant oil and natural gas resources of the Middle East and Middle Asia countries to the Western market. Furthermore, Turkey is planning to increase its oil and gas pipeline infrastructure to accommodate its increased energy consumption. Naturally, Turkish natural gas usage is projected to increase remarkably in coming years, with the prime consumers, expected to be industry and power plants. Energy demand of Turkey is growing by 8% annually, one of the highest rates in the world. In addition, natural gas consumption is the fastest growing primary energy source in Turkey. Gas sales started at 0.5 bcm (billion cubic meters), in 1987 and reached approximately 22 bcm in 2003. This article deals with energy policies and natural gas consumption of Turkey. Besides modernization of present lines and realization of capacity increase, new lines will also be needed. In this context, Turkey, due to its geographical location is, in an important position to vary European supply. Therefore, Turkey's role as a transitory area gains importance.

Administrative database code accuracy did not vary notably with changes in disease prevalence.

Science.gov (United States)

van Walraven, Carl; English, Shane; Austin, Peter C

2016-11-01

Previous mathematical analyses of diagnostic tests based on the categorization of a continuous measure have found that test sensitivity and specificity varies significantly by disease prevalence. This study determined if the accuracy of diagnostic codes varied by disease prevalence. We used data from two previous studies in which the true status of renal disease and primary subarachnoid hemorrhage, respectively, had been determined. In multiple stratified random samples from the two previous studies having varying disease prevalence, we measured the accuracy of diagnostic codes for each disease using sensitivity, specificity, and positive and negative predictive value. Diagnostic code sensitivity and specificity did not change notably within clinically sensible disease prevalence. In contrast, positive and negative predictive values changed significantly with disease prevalence. Disease prevalence had no important influence on the sensitivity and specificity of diagnostic codes in administrative databases. Copyright © 2016 Elsevier Inc. All rights reserved.

Green positive guidance and green positive life counseling for decent work and decent lives:Some empirical results

Directory of Open Access Journals (Sweden)

Annamaria eDi Fabio

2016-03-01

Full Text Available This article discusses green positive guidance and green positive life counseling for decent work and decent lives. From a green guidance perspective, the connectedness to nature construct is important both in terms of the meaning of work and life construction. The study discussed in this article analyzed the relationship between empathy and connectedness to nature, controlling for the effects of fluid intelligence and personality traits. In this connection, the Advanced Progressive Matrices (APM, the Big Five Questionnaire (BFQ, and the Interpersonal Reactivity Index (IRI were administered to 144 Italian high school students. The study revealed that connecteness to nature was not associated with fluid intelligence and was only moderately associated with personality traits. It was empathy that showed the highest association with connectedness to nature. The results open new opportunities for future research and interventions in green positive guidance/life counseling and green positive decent work.

Ontogenetic shifts of heart position in snakes.

Science.gov (United States)

Lillywhite, Harvey B; Lillywhite, Steven M

2017-08-01

Heart position relative to total body length (TL) varies among snakes, with anterior hearts in arboreal species and more centrally located hearts in aquatic or ground-dwelling species. Anterior hearts decrease the cardiac work associated with cranial blood flow and minimize drops in cranial pressure and flow during head-up climbing. Here, we investigate whether heart position shifts intraspecifically during ontogenetic increases in TL. Insular Florida cottonmouth snakes, Agkistrodon conanti, are entirely ground-dwelling and have a mean heart position that is 33.32% TL from the head. In contrast, arboreal rat snakes, Pantherophis obsoleta, of similar lengths have a mean heart position that is 17.35% TL from the head. In both species, relative heart position shifts craniad during ontogeny, with negative slopes = -.035 and -.021% TL/cm TL in Agkistrodon and Pantherophis, respectively. Using a large morphometric data set available for Agkistrodon (N = 192 individuals, 23-140 cm TL), we demonstrate there is an anterior ontogenetic shift of the heart position within the trunk (= 4.56% trunk length from base of head to cloacal vent), independent of head and tail allometry which are both negative. However, in longer snakes > 100 cm, the heart position reverses and shifts caudally in longer Agkistrodon but continues toward the head in longer individuals of Pantherophis. Examination of data sets for two independent lineages of fully marine snakes (Acrochordus granulatus and Hydrophis platurus), which do not naturally experience postural gravity stress, demonstrate both ontogenetic patterns for heart position that are seen in the terrestrial snakes. The anterior migration of the heart is greater in the terrestrial species, even if TL is standardized to that of the longer P. obsoleta, and compensates for about 5 mmHg gravitational pressure head if they are fully upright. © 2017 Wiley Periodicals, Inc.

Synthesis, structural, optical and morphological characterization of hematite through the precipitation method: Effect of varying the nature of the base

Science.gov (United States)

Lassoued, Abdelmajid; Lassoued, Mohamed Saber; Dkhil, Brahim; Gadri, Abdellatif; Ammar, Salah

2017-08-01

Iron oxide (α-Fe2O3) nanoparticles were synthesized using the precipitation synthesis method focusing only on (FeCl3, 6H2O), NaOH, KOH and NH4OH as raw materials. The impact of varying the nature of the base on the crystalline phase, size and morphology of α-Fe2O3 products was explored. XRD spectra revealed that samples crystallize in the rhombohedral (hexagonal) system at 800 °C.The Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to detect the morphology of synthesized nanoparticles and specify their sizes. However, the Fourier Transform Infra-Red (FT-IR) spectroscopy has permitted the observation of vibration band Fe-O. Raman spectroscopy was used not only to prove that we have synthesized hematite but also to identify their phonon modes. The Thermo Gravimetric Analysis (TGA) findings allow the thermal cycle determination of samples whereas Differential Thermal Analysis (DTA) findings allow the phase transition temperature identification. Besides, the optical investigation revealed that samples have an optical gap of about 2.1 eV. Findings highlight that the nature of the agent precipitant plays a significant role in the morphology of the products and the formation of the crystalline phase. Hematite synthesis with the base NH4OH brought about much stronger, sharper and wider diffraction peaks of α-Fe2O3. The morphology of samples are spherical with a size of about 61 nm while the size of the nanoparticles of hematite which we have synthesized with NaOH and KOH is respectively of the order of 82 and 79 nm.

Faculty Perceptions of Conflict with Administrators: An Analysis of the Associations between the Nature of Conflict and Positive and Negative Outcomes

Science.gov (United States)

Hancks, Meredith L.

2013-01-01

This study examines the perceptions of faculty members regarding conflict experiences with administrators. It is driven by the question, "To what extent are faculty perceptions of positive and negative outcomes of faculty-administrator conflict associated with domain, nature and disciplinary context of the conflict," where domain refers…

Varying Constants, Gravitation and Cosmology

Directory of Open Access Journals (Sweden)

Jean-Philippe Uzan

2011-03-01

Full Text Available Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.

Combination technique for improving natural convection cooling in electronics

Energy Technology Data Exchange (ETDEWEB)

Florio, L.A.; Harnoy, A. [Department of Mechanical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102 (United States)

2007-01-15

The combination of an appropriately placed cross-flow opening and a strategically positioned transversely vibrating plate is proposed as a means of augmenting pure natural convection in a vertical channel. This method is intended to provide a more efficient, reliable, and consumer conscious alternative to conventional techniques for lower power dissipating devices where standard natural convection cooling proves insufficient. Two-dimensional numerical simulations are employed to investigate this combination method using models consisting of a vertical channel containing two rectangular heat sources which are attached to a vertical mounting board, as well as a transversely oscillating plate and a cross-flow opening in the mounting board area between the two heat sources. Varied parameters and geometric configurations are studied. The results indicate the combined effects of the vibrating plate and the opening flow have the potential to cause significant improvement in the thermal conditions over pure natural convection. As much as a 70% improvement in the local heat transfer coefficient from that for a system with a board opening but without a vibrating plate was attained. (author)

Performance exploration of an energy harvester near the varying magnetic field of an operating induction motor

International Nuclear Information System (INIS)

Uzun, Yunus; Kurt, Erol

2013-01-01

Highlights: • This paper explores the piezoelectric harvester performance. • The varying magnetic field generates electricity via exciting harvester. • Generated power should be optimized via load resistance. • 0.11 mW/cm 3 Power can be generated from 500 cm 3 surrounding volume. - Abstract: This paper reports a performance exploration of a piezoelectric harvester which is positioned near an operating induction motor. The harvester includes a magnet knob in a pendulum arrangement, which ascertains mechanical vibrations under the varying magnetic field. This energy harvester transforms the ambient unused magnetic energy into the electricity due to the piezoelectric layer attached to the pendulum. It has been proven that when the motor is under operation, the varying ambient field causes a varying magnetic force at the tip of harvester, then output voltage between the terminals of piezoelectric layer is produced due to the mechanical vibrations. This output signal has some characteristics of the operating induction motor in terms of its operation frequency, number of magnetic pole and natural frequency of the harvester. Since the surrounding field of the induction motor directly depends on the current flowing through the windings and electrical parameters, both the amplitude U and the frequency ω m of the harvested voltage can be characterized after some certain parametrical explorations. It has been proven that the harvested voltage strictly depends on the electrical load, which is attached to the terminals of the harvester, after the rectifying circuit. The harvested power per surrounding volume can be increased up to 0.11 mW/cm 3 , if the entire surrounding volume of the motor is considered

Cesarean Delivery Changes the Natural Position of the Uterus on Transvaginal Ultrasonography.

Science.gov (United States)

Kaelin Agten, Andrea; Honart, Anne; Monteagudo, Ana; McClelland, Spencer; Basher, Basmy; Timor-Tritsch, Ilan E

2018-05-01

To assess whether cesarean delivery changes the natural position of the uterus. In this retrospective Institutional Review Board-approved cohort study, we conducted a search of our university gynecologic ultrasonography (US) database. Patients with transvaginal US images before and after either vaginal or cesarean delivery between 2012 and 2015 were included. Women with prior cesarean delivery were excluded. Two readers independently measured antepartum and postpartum flexion angles between the longitudinal axis of the uterine body and the cervix. We calculated intraclass correlation coefficients to measure inter-reader agreement. Antepartum and postpartum uterine flexion angles were compared between patients with vaginal and cesarean delivery. We included 173 patients (107 vaginal and 66 cesarean delivery). The mean interval between scans ± SD was 18 ± 10 months. Inter-reader agreement for flexion angles was almost perfect (intraclass correlation coefficients: antepartum, 0.939; postpartum, 0.969; both P cesarean delivery (154.8° ± 45.7°) versus vaginal delivery (145.8° ± 43.7°; P = .216). Mean postpartum flexion angles were higher after cesarean delivery (180.4° ± 51.2°) versus vaginal delivery (152.8° ± 47.7°; P = .001. Differences in antepartum and postpartum flexion angles between cesarean and vaginal delivery were statistically significant (25.6° versus 7.0°; P = .027). Cesarean delivery can change the uterine flexion angle to a more retroflexed position. Therefore, all women with a history of cesarean delivery should undergo a transvaginal US examination before any gynecologic surgery or intrauterine device placement to reduce the possibility of surgical complications. © 2017 by the American Institute of Ultrasound in Medicine.

The relationship between parity and overweight varies with household wealth and national development.

Science.gov (United States)

Kim, Sonia A; Yount, Kathryn M; Ramakrishnan, Usha; Martorell, Reynaldo

2007-02-01

Recent studies support a positive relationship between parity and overweight among women of developing countries; however, it is unclear whether these effects vary by household wealth and national development. Our objective was to determine whether the association between parity and overweight [body mass index (BMI) > or =25 kg/m(2)] in women living in developing countries varies with levels of national human development and/or household wealth. We used data from 28 nationally representative, cross-sectional surveys conducted between 1996 and 2003 (n = 275 704 women, 15-49 years). The relationship between parity and overweight was modelled using logistic regression, controlling for several biological and sociodemographic factors and national development, as reflected by the United Nations' Human Development Index. We also modelled the interaction between parity and national development, and the three-way interaction between parity, household wealth and national development. Parity had a weak, positive association with overweight, which varied by household wealth and national development. Among the poorest women and women in the second tertile of household wealth, parity was positively related to overweight only in the most developed countries. Among the wealthiest women, parity was positively related to overweight regardless of the level of national development. As development increases, the burden of parity-related overweight shifts to include poor as well as wealthy women. In the least-developed countries, programmes to prevent parity-related overweight should target wealthy women, whereas such programmes should be provided to all women in more developed countries.

Positivity of the English Language

Science.gov (United States)

Kloumann, Isabel M.; Danforth, Christopher M.; Harris, Kameron Decker; Bliss, Catherine A.; Dodds, Peter Sheridan

2012-01-01

Over the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1) What is the emotional spectrum of natural language? and (2) Are natural languages neutrally, positively, or negatively biased? Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is broadly invariant with respect to frequency of word use. PMID:22247779

Positivity of the English language.

Directory of Open Access Journals (Sweden)

Isabel M Kloumann

Full Text Available Over the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1 What is the emotional spectrum of natural language? and (2 Are natural languages neutrally, positively, or negatively biased? Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is broadly invariant with respect to frequency of word use.

Modeling information diffusion in time-varying community networks

Science.gov (United States)

Cui, Xuelian; Zhao, Narisa

2017-12-01

Social networks are rarely static, and they typically have time-varying network topologies. A great number of studies have modeled temporal networks and explored social contagion processes within these models; however, few of these studies have considered community structure variations. In this paper, we present a study of how the time-varying property of a modular structure influences the information dissemination. First, we propose a continuous-time Markov model of information diffusion where two parameters, mobility rate and community attractiveness, are introduced to address the time-varying nature of the community structure. The basic reproduction number is derived, and the accuracy of this model is evaluated by comparing the simulation and theoretical results. Furthermore, numerical results illustrate that generally both the mobility rate and community attractiveness significantly promote the information diffusion process, especially in the initial outbreak stage. Moreover, the strength of this promotion effect is much stronger when the modularity is higher. Counterintuitively, it is found that when all communities have the same attractiveness, social mobility no longer accelerates the diffusion process. In addition, we show that the local spreading in the advantage group has been greatly enhanced due to the agglomeration effect caused by the social mobility and community attractiveness difference, which thus increases the global spreading.

A New Time-varying Concept of Risk in a Changing Climate

Science.gov (United States)

Sarhadi, Ali; Ausín, María Concepción; Wiper, Michael P.

2016-10-01

In a changing climate arising from anthropogenic global warming, the nature of extreme climatic events is changing over time. Existing analytical stationary-based risk methods, however, assume multi-dimensional extreme climate phenomena will not significantly vary over time. To strengthen the reliability of infrastructure designs and the management of water systems in the changing environment, multidimensional stationary risk studies should be replaced with a new adaptive perspective. The results of a comparison indicate that current multi-dimensional stationary risk frameworks are no longer applicable to projecting the changing behaviour of multi-dimensional extreme climate processes. Using static stationary-based multivariate risk methods may lead to undesirable consequences in designing water system infrastructures. The static stationary concept should be replaced with a flexible multi-dimensional time-varying risk framework. The present study introduces a new multi-dimensional time-varying risk concept to be incorporated in updating infrastructure design strategies under changing environments arising from human-induced climate change. The proposed generalized time-varying risk concept can be applied for all stochastic multi-dimensional systems that are under the influence of changing environments.

A New Time-varying Concept of Risk in a Changing Climate.

Science.gov (United States)

Sarhadi, Ali; Ausín, María Concepción; Wiper, Michael P

2016-10-20

In a changing climate arising from anthropogenic global warming, the nature of extreme climatic events is changing over time. Existing analytical stationary-based risk methods, however, assume multi-dimensional extreme climate phenomena will not significantly vary over time. To strengthen the reliability of infrastructure designs and the management of water systems in the changing environment, multidimensional stationary risk studies should be replaced with a new adaptive perspective. The results of a comparison indicate that current multi-dimensional stationary risk frameworks are no longer applicable to projecting the changing behaviour of multi-dimensional extreme climate processes. Using static stationary-based multivariate risk methods may lead to undesirable consequences in designing water system infrastructures. The static stationary concept should be replaced with a flexible multi-dimensional time-varying risk framework. The present study introduces a new multi-dimensional time-varying risk concept to be incorporated in updating infrastructure design strategies under changing environments arising from human-induced climate change. The proposed generalized time-varying risk concept can be applied for all stochastic multi-dimensional systems that are under the influence of changing environments.

Natural selection on protein-coding genes in the human genome

DEFF Research Database (Denmark)

Bustamente, Carlos D.; Fledel-Alon, Adi; Williamson, Scott

2005-01-01

, showing an excess of deleterious variation within local populations 9, 10 . Here we contrast patterns of coding sequence polymorphism identified by direct sequencing of 39 humans for over 11,000 genes to divergence between humans and chimpanzees, and find strong evidence that natural selection has shaped......Comparisons of DNA polymorphism within species to divergence between species enables the discovery of molecular adaptation in evolutionarily constrained genes as well as the differentiation of weak from strong purifying selection 1, 2, 3, 4 . The extent to which weak negative and positive darwinian...... selection have driven the molecular evolution of different species varies greatly 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 , with some species, such as Drosophila melanogaster, showing strong evidence of pervasive positive selection 6, 7, 8, 9 , and others, such as the selfing weed Arabidopsis thaliana...

Disaster Mental Health and Positive Psychology-Considering the Context of Natural and Technological Disasters: An Introduction to the Special Issue.

Science.gov (United States)

Schulenberg, Stefan E

2016-12-01

This article serves as an introduction to the Journal of Clinical Psychology's special issue on disaster mental health and positive psychology. The special issue comprises two sections. The first section presents a series of data-driven articles and research-informed reviews examining meaning and resilience in the context of natural and technological disasters. The second section presents key topics in the area of disaster mental health, with particular relevance for positive psychology and related frameworks. The special issue is intended to bridge the gap between these two areas of applied science, with the audience being experienced clinicians or clinicians in training. © 2016 Wiley Periodicals, Inc.

Spatially varying determinants of farmland conversion across Qiantang watershed, China.

Science.gov (United States)

Su, Shiliang; Xiao, Rui

2013-10-01

This paper employed geographically weighted regression (GWR) to characterize the determinants of farmland conversion at administrative scale between 1994 and 2003 across Qiantang watershed, China. Six determinants were identified: total area of forest, distance to highway, distance to second road, distance to river, population, and gross domestic product. Relationships between these identified determinants and farmland conversion showed great spatial non-stationarity, since their character, nature, and strength varied significantly across space. Typically, for cities whose development was heavily relied on road infrastructure development, the impacts of "distance to second road" and "distance to river" was negative. However, in mountainous areas, the restriction of terrain factors led to positive impacts from these two variables. For areas undergoing rapid socio-economic development, farmland conversion was accelerated by population growth and economic development. However, for more urbanized regions, a slow-down rate of farmland conversion would be expected. Our study highlighted that the problem of spatial non-stationarity should be addressed when qualifying the determinants of farmland conversion. Linking our results within the context of farmland protection, we argue that implementing local-specific land management practices, instead of the current one-size-fits-all framework, is the key for the success of farmland protection in China.

Teaching about Natural Background Radiation

Science.gov (United States)

Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

2013-01-01

Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

Identifying typical physical activity on smartphone with varying positions and orientations.

Science.gov (United States)

Miao, Fen; He, Yi; Liu, Jinlei; Li, Ye; Ayoola, Idowu

2015-04-13

Traditional activity recognition solutions are not widely applicable due to a high cost and inconvenience to use with numerous sensors. This paper aims to automatically recognize physical activity with the help of the built-in sensors of the widespread smartphone without any limitation of firm attachment to the human body. By introducing a method to judge whether the phone is in a pocket, we investigated the data collected from six positions of seven subjects, chose five signals that are insensitive to orientation for activity classification. Decision trees (J48), Naive Bayes and Sequential minimal optimization (SMO) were employed to recognize five activities: static, walking, running, walking upstairs and walking downstairs. The experimental results based on 8,097 activity data demonstrated that the J48 classifier produced the best performance with an average recognition accuracy of 89.6% during the three classifiers, and thus would serve as the optimal online classifier. The utilization of the built-in sensors of the smartphone to recognize typical physical activities without any limitation of firm attachment is feasible.

Parallel programming of saccades during natural scene viewing: evidence from eye movement positions.

Science.gov (United States)

Wu, Esther X W; Gilani, Syed Omer; van Boxtel, Jeroen J A; Amihai, Ido; Chua, Fook Kee; Yen, Shih-Cheng

2013-10-24

Previous studies have shown that saccade plans during natural scene viewing can be programmed in parallel. This evidence comes mainly from temporal indicators, i.e., fixation durations and latencies. In the current study, we asked whether eye movement positions recorded during scene viewing also reflect parallel programming of saccades. As participants viewed scenes in preparation for a memory task, their inspection of the scene was suddenly disrupted by a transition to another scene. We examined whether saccades after the transition were invariably directed immediately toward the center or were contingent on saccade onset times relative to the transition. The results, which showed a dissociation in eye movement behavior between two groups of saccades after the scene transition, supported the parallel programming account. Saccades with relatively long onset times (>100 ms) after the transition were directed immediately toward the center of the scene, probably to restart scene exploration. Saccades with short onset times (programming of saccades during scene viewing. Additionally, results from the analyses of intersaccadic intervals were also consistent with the parallel programming hypothesis.

Positive approach: Implications for the relation between number theory and geometry, including connection to Santilli mathematics, from Fibonacci reconstitution of natural numbers and of prime numbers

International Nuclear Information System (INIS)

Johansen, Stein E.

2014-01-01

The paper recapitulates some key elements in previously published results concerning exact and complete reconstitution of the field of natural numbers, both as ordinal and as cardinal numbers, from systematic unfoldment of the Fibonacci algorithm. By this natural numbers emerge as Fibonacci 'atoms' and 'molecules' consistent with the notion of Zeckendorf sums. Here, the sub-set of prime numbers appears not as the primary numbers, but as an epistructure from a deeper Fibonacci constitution, and is thus targeted from a 'positive approach'. In the Fibonacci reconstitution of number theory natural numbers show a double geometrical aspect: partly as extension in space and partly as position in a successive structuring of space. More specifically, the natural numbers are shown to be distributed by a concise 5:3 code structured from the Fibonacci algorithm via Pascal's triangle. The paper discusses possible implications for the more general relation between number theory and geometry, as well as more specifically in relation to hadronic mathematics, initiated by R.M. Santilli, and also briefly to some other recent science linking number theory more directly to geometry and natural systems

Positive approach: Implications for the relation between number theory and geometry, including connection to Santilli mathematics, from Fibonacci reconstitution of natural numbers and of prime numbers

Energy Technology Data Exchange (ETDEWEB)

Johansen, Stein E., E-mail: stein.johansen@svt.ntnu.no [Institute for Basic Research, Division of Physics, Palm Harbor, Florida, USA and Norwegian University of Science and Technology, Department of Social Anthropology, Trondheim (Norway)

2014-12-10

The paper recapitulates some key elements in previously published results concerning exact and complete reconstitution of the field of natural numbers, both as ordinal and as cardinal numbers, from systematic unfoldment of the Fibonacci algorithm. By this natural numbers emerge as Fibonacci 'atoms' and 'molecules' consistent with the notion of Zeckendorf sums. Here, the sub-set of prime numbers appears not as the primary numbers, but as an epistructure from a deeper Fibonacci constitution, and is thus targeted from a 'positive approach'. In the Fibonacci reconstitution of number theory natural numbers show a double geometrical aspect: partly as extension in space and partly as position in a successive structuring of space. More specifically, the natural numbers are shown to be distributed by a concise 5:3 code structured from the Fibonacci algorithm via Pascal's triangle. The paper discusses possible implications for the more general relation between number theory and geometry, as well as more specifically in relation to hadronic mathematics, initiated by R.M. Santilli, and also briefly to some other recent science linking number theory more directly to geometry and natural systems.

Varied effects of thoracic irradiation on peripheral lymphocyte subsets in lung cancer patients

International Nuclear Information System (INIS)

Nakayama, Yasuhiro; Makino, Shigeki; Fukuda, Yasuki; Min, Kyong-Yob; Ikemoto, Toshiyuki; Shimizu, Akira; Ohsawa, Nakaaki

1995-01-01

To investigate the influence of thoracic irradiation on immunological competence in patients with lung cancer, we examined the changes in peripheral blood lymphocyte subsets in 15 patients before and after radiation therapy by two-color flow cytometry techniques. After radiation therapy, the percentage and the absolute number of CD4+CD45RA+ cells (naive T cells) and CD56+and/orCD16+ cells (NK cells) decreased. The percentage of CD4+ human leukocyte antigen-DR(HLA-DR)+ cells (activated CD4T cells) and CD8+HLA-DR+ cells (activated CD8T cells) increased, although the absolute number did not change significantly. Naive T cells may be more selectively damaged than memory T cells by thoracic irradiation, through their recirculation behavior. The reduction of natural killer (NK) cells is disadvantageous for anti-tumor immunity. The percentage of HLA-DR positive T lymphocytes was significantly increased, and thus the possibility of HLA-DR enhancement by irradiation cannot be excluded. Therefore, thoracic irradiation has numerous varied effects on the immunological system of lung cancer patients. (author)

Red Roses and Gift Chocolates Are Judged More Positively in the U.S. Near Valentine's Day: Evidence of Naturally Occurring Cultural Priming.

Science.gov (United States)

Zayas, Vivian; Pandey, Gayathri; Tabak, Joshua

2017-01-01

Attitudes are not static, but constructed at the moment of the evaluation, incorporating temporary contextual influences. How do meaningful events that naturally occur within a culture, such as a national holiday, shape evaluative judgments of objects related to the holiday? We focused on evaluations of red roses and gift chocolates, which are everyday objects, but also iconic of Valentine's Day in the U.S. We reasoned that if cultural events shape evaluations, then roses and chocolates would be evaluated differently near Valentine's Day. Using a large and diverse U.S. sample, we found that as Valentine's Day neared, evaluations of roses and chocolates (but not a comparison object) were evaluated more positively. Increases in positivity of roses and chocolates covaried with their increased cultural relevance, as quantified by the volume of web search queries involving these terms. These findings provide a demonstration of naturally occurring cultural priming by which the salience of cultural events shape evaluations.

Natural resistance to experimental feline infectious peritonitis virus infection is decreased rather than increased by positive genetic selection.

Science.gov (United States)

Pedersen, Niels C; Liu, Hongwei; Durden, Monica; Lyons, Leslie A

2016-03-01

A previous study demonstrated the existence of a natural resistance to feline infectious peritonitis virus (FIPV) among 36% of randomly bred laboratory cats. A genome wide association study (GWAS) on this population suggested that resistance was polygenic but failed to identify any strong specific associations. In order to enhance the power of GWAS or whole genome sequencing to identify strong genetic associations, a decision was made to positively select for resistance over three generations. The inbreeding experiment began with a genetically related parental (P) population consisting of three toms and four queens identified from among the survivors of the earlier study and belonging to a closely related subgroup (B). The subsequent effects of inbreeding were measured using 42 genome-wide STR markers. P generation cats produced 57 first filial (F1) kittens, only five of which (9.0%) demonstrated a natural resistance to FIPV infection. One of these five F1 survivors was then used to produce six F1/P-backcrosses kittens, only one of which proved resistant to FIP. Six of eight of the F1 and F1/P survivors succumbed to a secondary exposure 4-12 months later. Therefore, survival after both primary and secondary infection was decreased rather than increased by positive selection for resistance. The common genetic factor associated with this diminished resistance was a loss of heterozygosity. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Socioeconomic position, lifestyle factors and age at natural menopause: a systematic review and meta-analyses of studies across six continents

Science.gov (United States)

Schoenaker, Danielle AJM; Jackson, Caroline A; Rowlands, Jemma V; Mishra, Gita D

2014-01-01

Background: Age at natural menopause (ANM) is considered a marker of biological ageing and is increasingly recognized as a sentinel for chronic disease risk in later life. Socioeconomic position (SEP) and lifestyle factors are thought to be associated with ANM. Methods: We performed a systematic review and meta-analyses to determine the overall mean ANM, and the effect of SEP and lifestyle factors on ANM by calculating the weighted mean difference (WMD) and pooling adjusted hazard ratios. We explored heterogeneity using meta-regression and also included unpublished findings from the Australian Longitudinal Study on Women’s Health. Results: We identified 46 studies across 24 countries. Mean ANM was 48.8 years [95% confidence interval (CI): 48.3, 49.2], with between-study heterogeneity partly explained by geographical region. ANM was lowest among African, Latin American, Asian and Middle Eastern countries and highest in Europe and Australia, followed by the USA. Education was associated with later ANM (WMD middle vs low education 0.30, 95% CI: 0.10, 0.51; high vs low education 0.64, 95% CI 0.26, 1.02). A similar dose-response relationship was also observed for occupation. Smoking was associated with a 1-year reduction of ANM (WMD: -0.91, 95% CI: –1.34, –0.48). Being overweight and moderate/high physical activity were modestly associated with later ANM, but findings were less conclusive. Conclusions: ANM varies across populations, partly due to differences across geographical regions. SEP and some lifestyle factors are associated with ANM, but further research is needed to examine the impact of the associations between risk factors and ANM on future health outcomes. PMID:24771324

A Tentative Application Of Morphological Filters To Time-Varying Images

Science.gov (United States)

Billard, D.; Poquillon, B.

1989-03-01

In this paper, morphological filters, which are commonly used to process either 2D or multidimensional static images, are generalized to the analysis of time-varying image sequence. The introduction of the time dimension induces then interesting prop-erties when designing such spatio-temporal morphological filters. In particular, the specification of spatio-temporal structuring ele-ments (equivalent to time-varying spatial structuring elements) can be adjusted according to the temporal variations of the image sequences to be processed : this allows to derive specific morphological transforms to perform noise filtering or moving objects discrimination on dynamic images viewed by a non-stationary sensor. First, a brief introduction to the basic principles underlying morphological filters will be given. Then, a straightforward gener-alization of these principles to time-varying images will be pro-posed. This will lead us to define spatio-temporal opening and closing and to introduce some of their possible applications to process dynamic images. At last, preliminary results obtained us-ing a natural forward looking infrared (FUR) image sequence are presented.

Positional games

CERN Document Server

Hefetz, Dan; Stojaković, Miloš; Szabó, Tibor

2014-01-01

This text serves as a thorough introduction to the rapidly developing field of positional games. This area constitutes an important branch of combinatorics, whose aim it is to systematically develop an extensive mathematical basis for a variety of two-player perfect information games. These range from such popular games as Tic-Tac-Toe and Hex to purely abstract games played on graphs and hypergraphs. The subject of positional games is strongly related to several other branches of combinatorics such as Ramsey theory, extremal graph and set theory, and the probabilistic method. These notes cover a variety of topics in positional games, including both classical results and recent important developments. They are presented in an accessible way and are accompanied by exercises of varying difficulty, helping the reader to better understand the theory. The text will benefit both researchers and graduate students in combinatorics and adjacent fields.

Time varying determinants of bond flows to emerging markets

Directory of Open Access Journals (Sweden)

Yasemin Erduman

2016-06-01

Full Text Available This paper investigates the time varying nature of the determinants of bond flows with a focus on the global financial crisis period. We estimate a time varying regression model using Bayesian estimation methods, where the posterior distribution is approximated by Gibbs sampling algorithm. Our findings suggest that the interest rate differential is the most significant pull factor of portfolio bond flows, along with the inflation rate, while the growth rate does not play a significant role. Among the push factors, global liquidity is the most important driver of bond flows. It matters the most, when unconventional monetary easing policies were first announced; and its importance as a determinant of portfolio bond flows decreases over time, starting with the Eurozone crisis, and diminishes with the tapering talk. Global risk appetite and the risk perception towards the emerging countries also have relatively small and stable significant effects on bond flows.

Anistropically varying conductivity in irreversible electroporation simulations.

Science.gov (United States)

Labarbera, Nicholas; Drapaca, Corina

2017-11-01

One recent area of cancer research is irreversible electroporation (IRE). Irreversible electroporation is a minimally invasive procedure where needle electrodes are inserted into the body to ablate tumor cells with electricity. The aim of this paper is to propose a mathematical model that incorporates a tissue's conductivity increasing more in the direction of the electrical field as this has been shown to occur in experiments. It was necessary to mathematically derive a valid form of the conductivity tensor such that it is dependent on the electrical field direction and can be easily implemented into numerical software. The derivation of a conductivity tensor that can take arbitrary functions for the conductivity in the directions tangent and normal to the electrical field is the main contribution of this paper. Numerical simulations were performed for isotropic-varying and anisotropic-varying conductivities to evaluate the importance of including the electrical field's direction in the formulation for conductivity. By starting from previously published experimental results, this paper derived a general formulation for an anistropic-varying tensor for implementation into irreversible electroporation modeling software. The anistropic-varying tensor formulation allows the conductivity to take into consideration both electrical field direction and magnitude, as opposed to previous published works that only took into account electrical field magnitude. The anisotropic formulation predicts roughly a five percent decrease in ablation size for the monopolar simulation and approximately a ten percent decrease in ablation size for the bipolar simulations. This is a positive result as previously reported results found the isotropic formulation to overpredict ablation size for both monopolar and bipolar simulations. Furthermore, it was also reported that the isotropic formulation overpredicts the ablation size more for the bipolar case than the monopolar case. Thus, our

The role of transcendent nature and awe experiences on positive environmental engagement

OpenAIRE

Davis, Nora

2016-01-01

Despite a rich popular narrative that awe-inspiring nature experiences promote environmental behavior, empirical work on this subject is lacking. Recent research has determined that individuals often experience the emotion awe in nature, and that this emotion can lead to reliable shifts in cognition, interpersonal perception, and social behavior. In addition, although research has found that nature exposure can shift environmental behavior, the emotional pathways underlying this association, ...

Performance of Traffic Noise Barriers with Varying Cross-Section

Directory of Open Access Journals (Sweden)

Sanja Grubeša

2011-05-01

Full Text Available The efficiency of noise barriers largely depends on their geometry. In this paper, the performance of noise barriers was simulated using the numerical Boundary Element Method (BEM. Traffic noise was particularly considered with its standardized noise spectrum adapted to human hearing. The cross-section of the barriers was varied with the goal of finding the optimum shape in comparison to classical rectangular barriers. The barrier performance was calculated at different receiver points for a fixed barrier height and source position. The magnitude of the insertion loss parameter was used to evaluate the performance change, both in one-third octave bands and as the broadband mean insertion loss value. The proposed barriers of varying cross-section were also compared with a typical T-shape barrier of the same height.

Tracking of [18F]FDG-labeled natural killer cells to HER2/neu-positive tumors

International Nuclear Information System (INIS)

Meier, Reinhard; Piert, Morand; Piontek, Guido; Rudelius, Martina; Oostendorp, Robert A.; Senekowitsch-Schmidtke, Reingard; Henning, Tobias D.; Wels, Winfried S.; Uherek, Christoph; Rummeny, Ernst J.; Daldrup-Link, Heike E.

2008-01-01

Introduction: The objective of this study was to label the human natural killer (NK) cell line NK-92 with [ 18 F]fluoro-deoxy-glucose (FDG) for subsequent in vivo tracking to HER2/neu-positive tumors. Methods: NK-92 cells were genetically modified to NK-92-scFv(FRP5)-zeta cells, which express a chimeric antigen receptor that is specific to the tumor-associated ErbB2 (HER2/neu) antigen. NK-92 and NK-92-scFv(FRP5)-zeta cells were labeled with [ 18 F]FDG by simple incubation at different settings. Labeling efficiency was evaluated by a gamma counter. Subsequently, [ 18 F]FDG-labeled parental NK-92 or NK-92-scFv(FRP5)-zeta cells were intravenously injected into mice with implanted HER2/neu-positive NIH/3T3 tumors. Radioactivity in tumors was quantified by digital autoradiography and correlated with histopathology. Results: The NK-92 and NK-92-scFv(FRP5)-zeta cells could be efficiently labeled with [ 18 F]FDG by simple incubation. Optimal labeling efficiencies (80%) were achieved using an incubation period of 60 min and additional insulin (10 IU/ml). After injection of 5x10 6 [ 18 F]FDG-labeled NK-92-scFv(FRP5)-zeta cells into tumor-bearing mice, digital autoradiography showed an increased uptake of radioactivity in HER2/neu-positive tumors at 60 min postinjection. Conversely, injection of 5x10 6 NK-92 cells not directed against HER2/neu receptors did not result in increased uptake of radioactivity in the tumors. Histopathology confirmed an accumulation of the NK-92-scFv(FRP5)-zeta cells, but not the parental NK cells, in tumor tissues. Conclusion: The human NK cell line NK-92 can be directed against HER2/neu antigens by genetic modification. The genetically modified NK cells can be efficiently labeled with [ 18 F]FDG, and the accumulation of these labeled NK cells in HER2/neu-positive tumors can be monitored with autoradiography

Positive Selection and Centrality in the Yeast and Fly Protein-Protein Interaction Networks

Directory of Open Access Journals (Sweden)

Sandip Chakraborty

2016-01-01

Full Text Available Proteins within a molecular network are expected to be subject to different selective pressures depending on their relative hierarchical positions. However, it is not obvious what genes within a network should be more likely to evolve under positive selection. On one hand, only mutations at genes with a relatively high degree of control over adaptive phenotypes (such as those encoding highly connected proteins are expected to be “seen” by natural selection. On the other hand, a high degree of pleiotropy at these genes is expected to hinder adaptation. Previous analyses of the human protein-protein interaction network have shown that genes under long-term, recurrent positive selection (as inferred from interspecific comparisons tend to act at the periphery of the network. It is unknown, however, whether these trends apply to other organisms. Here, we show that long-term positive selection has preferentially targeted the periphery of the yeast interactome. Conversely, in flies, genes under positive selection encode significantly more connected and central proteins. These observations are not due to covariation of genes’ adaptability and centrality with confounding factors. Therefore, the distribution of proteins encoded by genes under recurrent positive selection across protein-protein interaction networks varies from one species to another.

Positions of human dwellings affect few tropical diseases near ...

African Journals Online (AJOL)

user

Some factors that possibly affect tropical disease distribution was investigated in about 500 randomize human dwellings. The studied factors include wild animals, domestic animals, wild plants, cultivated plants, nature of soil, nature of water, positions of human dwellings, nature of building material and position of animal ...

Varying occurrence of extended-spectrum beta-lactamase bacteria among three produce types

KAUST Repository

Toh, Benjamin E. W.; Bokhari, Osama Mohammed; Kutbi, Abdullah; Haroon, Mohamed; Mantilla-Calderon, David; Zowawi, Hosam; Hong, Pei-Ying

2017-01-01

Three types of vegetables were sampled and evaluated over 1.5 years to determine differences in their associated bacterial isolates. Particular emphasis was placed on identifying pathogenic strains that were positive for extended spectrum beta-lactamase (ESBL). Quantitative estimates of the microbial risk associated with the ESBL-positive pathogens showed that different produce types may incur varying levels of ingestion risk. Most of the currently reported ESBL-positive bacterial isolates have been identified in nosocomial environments. However, the carriage of such drug-resistant bacteria in vegetables suggests a possible connection between our daily diet and human health.

In-plane vibrations of inhomogeneous curved bars having varying cross-section

International Nuclear Information System (INIS)

Suzuki, Katsuyoshi; Kosawada, Tadashi; Takahashi, Shin

1986-01-01

An exact method using power series expansions is presented for solving in-plane free vibration problems of inhomogeneous curved bars having varying curvatures and cross-sections. Equations of motion and boundary conditions are derived from the stationary conditions of the Lagrangian of curved bars. Natural frequencies and mode shapes are presented for elliptical and circular arc bars having both ends clamped and calmped-free ends. (author)

Regional scenario building as a tool to support vulnerability assessment of food & water security and livelihood conditions under varying natural resources managements

Science.gov (United States)

Reinhardt, Julia; Liersch, Stefan; Dickens, Chris; Kabaseke, Clovis; Mulugeta Lemenih, Kassaye; Sghaier, Mongi; Hattermann, Fred

2013-04-01

state and availability of natural resources. Major concerns in all CS are the fast growing populations and natural resources degradation because of unsustainable natural resource management. Land use and resource competition are a consequence of unclear land tenure systems and limited resources availability. Scarce rainfall with high annual variability causes food insecurity if yield failures cannot be compensated, e.g. because of lacking financial resources. In all case studies critical uncertainties were identified to be more or less related to "poor governance". Missing governmental and political stability and effectiveness as well as corruption hamper the implementation of laws and policies related to natural resource management. Other critical uncertainties lie in the social domain. They are either related to demographic patterns like emigration or immigration varying the pressure on natural resources use or to the society in general like the evolvement of people's environmental awareness or voice and accountability. Methodological outcomes of the scenario building were that the complexity of the process requires the use of reliable and powerful tools to support the communication process. Concept maps were found to be a useful tool in this regard.

Edge Modeling by Two Blur Parameters in Varying Contrasts.

Science.gov (United States)

Seo, Suyoung

2018-06-01

This paper presents a method of modeling edge profiles with two blur parameters, and estimating and predicting those edge parameters with varying brightness combinations and camera-to-object distances (COD). First, the validity of the edge model is proven mathematically. Then, it is proven experimentally with edges from a set of images captured for specifically designed target sheets and with edges from natural images. Estimation of the two blur parameters for each observed edge profile is performed with a brute-force method to find parameters that produce global minimum errors. Then, using the estimated blur parameters, actual blur parameters of edges with arbitrary brightness combinations are predicted using a surface interpolation method (i.e., kriging). The predicted surfaces show that the two blur parameters of the proposed edge model depend on both dark-side edge brightness and light-side edge brightness following a certain global trend. This is similar across varying CODs. The proposed edge model is compared with a one-blur parameter edge model using experiments of the root mean squared error for fitting the edge models to each observed edge profile. The comparison results suggest that the proposed edge model has superiority over the one-blur parameter edge model in most cases where edges have varying brightness combinations.

Natural-gas futures: Bias, predictive performance, and the theory of storage

International Nuclear Information System (INIS)

Modjtahedi, Bagher; Movassagh, Nahid

2005-01-01

This study reports several empirical findings concerning natural gas futures prices. First, spot and futures prices are non-stationary and the observed trends are due to positive drifts in the random-walk components of the prices rather than possible deterministic time trends. Second, market forecast errors are stationary. Third, futures are less than expected future spot prices so that futures are backdated. Fourth, the bias in the futures prices is time varying. Fifth, futures have statistically significant market-timing ability, despite the bias in the magnitude forecasts. Finally, the data lends partial support to the cost-of-carry theory of the basis determination. (Author)

Natural-gas futures: Bias, predictive performance, and the theory of storage

Energy Technology Data Exchange (ETDEWEB)

Modjtahedi, Bagher [California Univ., Davis, CA (United States); California Franchise Tax Board, CA (United States); Movassagh, Nahid [California Energy Commission, MS22, Sacramento, CA (United States)

2005-07-01

This study reports several empirical findings concerning natural gas futures prices. First, spot and futures prices are non-stationary and the observed trends are due to positive drifts in the random-walk components of the prices rather than possible deterministic time trends. Second, market forecast errors are stationary. Third, futures are less than expected future spot prices so that futures are backdated. Fourth, the bias in the futures prices is time varying. Fifth, futures have statistically significant market-timing ability, despite the bias in the magnitude forecasts. Finally, the data lends partial support to the cost-of-carry theory of the basis determination. (Author)

Acquired Antibody Responses against Plasmodium vivax Infection Vary with Host Genotype for Duffy Antigen Receptor for Chemokines (DARC)

Science.gov (United States)

Maestre, Amanda; Muskus, Carlos; Duque, Victoria; Agudelo, Olga; Liu, Pu; Takagi, Akihide; Ntumngia, Francis B.; Adams, John H.; Sim, Kim Lee; Hoffman, Stephen L.; Corradin, Giampietro; Velez, Ivan D.; Wang, Ruobing

2010-01-01

Background Polymorphism of the Duffy Antigen Receptor for Chemokines (DARC) is associated with susceptibility to and the severity of Plasmodium vivax malaria in humans. P. vivax uses DARC to invade erythrocytes. Individuals lacking DARC are ‘resistant’ to P. vivax erythrocytic infection. However, susceptibility to P. vivax in DARC+ individuals is reported to vary between specific DARC genotypes. We hypothesized that the natural acquisition of antibodies to P. vivax blood stages may vary with the host genotype and the level of DARC expression. Furthermore, high parasitemia has been reported to effect the acquisition of immunity against pre-erythrocytic parasites. We investigated the correlation between host DARC genotypes and the frequency and magnitude of antibodies against P. vivax erythrocytic stage antigens. Methodology/Findings We assessed the frequencies and magnitudes of antibody responses against P. vivax and P. falciparum sporozoite and erythrocytic antigens in Colombian donors from malaria-endemic regions. The frequency and level of naturally-acquired antibodies against the P. vivax erythrocytic antigens merozoite surface protein 1 (PvMSP1) and Duffy binding protein (PvDBP) varied with the host DARC genotypes. Donors with one negative allele (FY*B/FY*Bnull and FY*A/FY*Bnull) were more likely to have anti-PvMSP1 and anti-PvDBP antibodies than those with two positive alleles (FY*B/FY*B and FY*A/FY*B). The lower IgG3 and IgG1 components of the total IgG response may account for the decreased responses to P. vivax erythrocytic antigens with FY*A/FY*B and FY*B/FY*B genotypes. No such association was detected with P. falciparum erythrocytic antigens, which does not use DARC for erythrocyte invasion. Conclusion/Significance Individuals with higher DARC expression, which is associated with higher susceptibility to P. vivax infection, exhibited low frequencies and magnitudes of P. vivax blood-stage specific antibody responses. This may indicate that one of the

Acquired antibody responses against Plasmodium vivax infection vary with host genotype for duffy antigen receptor for chemokines (DARC.

Directory of Open Access Journals (Sweden)

Amanda Maestre

2010-07-01

Full Text Available Polymorphism of the Duffy Antigen Receptor for Chemokines (DARC is associated with susceptibility to and the severity of Plasmodium vivax malaria in humans. P. vivax uses DARC to invade erythrocytes. Individuals lacking DARC are 'resistant' to P. vivax erythrocytic infection. However, susceptibility to P. vivax in DARC+ individuals is reported to vary between specific DARC genotypes. We hypothesized that the natural acquisition of antibodies to P. vivax blood stages may vary with the host genotype and the level of DARC expression. Furthermore, high parasitemia has been reported to effect the acquisition of immunity against pre-erythrocytic parasites. We investigated the correlation between host DARC genotypes and the frequency and magnitude of antibodies against P. vivax erythrocytic stage antigens.We assessed the frequencies and magnitudes of antibody responses against P. vivax and P. falciparum sporozoite and erythrocytic antigens in Colombian donors from malaria-endemic regions. The frequency and level of naturally-acquired antibodies against the P. vivax erythrocytic antigens merozoite surface protein 1 (PvMSP1 and Duffy binding protein (PvDBP varied with the host DARC genotypes. Donors with one negative allele (FY*B/FY*Bnull and FY*A/FY*Bnull were more likely to have anti-PvMSP1 and anti-PvDBP antibodies than those with two positive alleles (FY*B/FY*B and FY*A/FY*B. The lower IgG3 and IgG1 components of the total IgG response may account for the decreased responses to P. vivax erythrocytic antigens with FY*A/FY*B and FY*B/FY*B genotypes. No such association was detected with P. falciparum erythrocytic antigens, which does not use DARC for erythrocyte invasion.Individuals with higher DARC expression, which is associated with higher susceptibility to P. vivax infection, exhibited low frequencies and magnitudes of P. vivax blood-stage specific antibody responses. This may indicate that one of the primary mechanisms by which P. vivax evades

Robust stabilisation of time-varying delay systems with probabilistic uncertainties

Science.gov (United States)

Jiang, Ning; Xiong, Junlin; Lam, James

2016-09-01

For robust stabilisation of time-varying delay systems, only sufficient conditions are available to date. A natural question is as follows: if the existing sufficient conditions are not satisfied, and hence no controllers can be found, what can one do to improve the stability performance of time-varying delay systems? This question is addressed in this paper when there is a probabilistic structure on the parameter uncertainty set. A randomised algorithm is proposed to design a state-feedback controller, which stabilises the system over the uncertainty domain in a probabilistic sense. The capability of the designed controller is quantified by the probability of stability of the resulting closed-loop system. The accuracy of the solution obtained from the randomised algorithm is also analysed. Finally, numerical examples are used to illustrate the effectiveness and advantages of the developed controller design approach.

Can positive social exchanges buffer the detrimental effects of negative social exchanges? Age and gender differences.

Science.gov (United States)

Fiori, Katherine L; Windsor, Tim D; Pearson, Elissa L; Crisp, Dimity A

2013-01-01

Findings from existing research exploring whether positive social exchanges can help to offset (or 'buffer' against) the harmful effects of negative social exchanges on mental health have been inconsistent. This could be because the existing research is characterized by different approaches to studying various contexts of 'cross-domain' and 'within-domain' buffering, and/or because the nature of buffering effects varies according to sociodemographic characteristics that underlie different aspects of social network structure and function. The purpose of this study was to examine whether the buffering effects of global perceptions of positive exchanges on the link between global negative exchanges and mental health varied as a function of age and gender. We used a series of regressions in a sample of 556 Australian older adults (ages 55-94) to test for three-way interactions among gender, positive social exchanges, and negative social exchanges, as well as age and positive and negative social exchanges, in predicting mental health, controlling for years of education, partner status, and physical functioning. We found that positive exchanges buffered against negative exchanges for younger old adults, but not for older old adults, and for women, but not for men. Our findings are interpreted in light of research on individual differences in coping responses and interpersonal goals among late middle-aged and older adults. Our findings are in line with gerontological theories (e.g., socioemotional selectivity theory), and imply that an intervention aimed at using positive social exchanges as a means of coping with negative social exchanges might be more successful among particular populations (i.e., women, 'younger' old adults). Copyright © 2012 S. Karger AG, Basel.

Interaction between gaze and visual and proprioceptive position judgements.

Science.gov (United States)

Fiehler, Katja; Rösler, Frank; Henriques, Denise Y P

2010-06-01

There is considerable evidence that targets for action are represented in a dynamic gaze-centered frame of reference, such that each gaze shift requires an internal updating of the target. Here, we investigated the effect of eye movements on the spatial representation of targets used for position judgements. Participants had their hand passively placed to a location, and then judged whether this location was left or right of a remembered visual or remembered proprioceptive target, while gaze direction was varied. Estimates of position of the remembered targets relative to the unseen position of the hand were assessed with an adaptive psychophysical procedure. These positional judgements significantly varied relative to gaze for both remembered visual and remembered proprioceptive targets. Our results suggest that relative target positions may also be represented in eye-centered coordinates. This implies similar spatial reference frames for action control and space perception when positions are coded relative to the hand.

Remote sensing captures varying temporal patterns of vegetation between human-altered and natural landscapes.

Science.gov (United States)

Leong, Misha; Roderick, George K

2015-01-01

Global change has led to shifts in phenology, potentially disrupting species interactions such as plant-pollinator relationships. Advances in remote sensing techniques allow one to detect vegetation phenological diversity between different land use types, but it is not clear how this translates to other communities in the ecosystem. Here, we investigated the phenological diversity of the vegetation across a human-altered landscape including urban, agricultural, and natural land use types. We found that the patterns of change in the vegetation indices (EVI and NDVI) of human-altered landscapes are out of synchronization with the phenology in neighboring natural California grassland habitat. Comparing these findings to a spatio-temporal pollinator distribution dataset, EVI and NDVI were significant predictors of total bee abundance, a relationship that improved with time lags. This evidence supports the importance of differences in temporal dynamics between land use types. These findings also highlight the potential to utilize remote sensing data to make predictions for components of biodiversity that have tight vegetation associations, such as pollinators.

Brown Dwarf Variability: What's Varying and Why?

Science.gov (United States)

Marley, Mark Scott

2014-01-01

Surveys by ground based telescopes, HST, and Spitzer have revealed that brown dwarfs of most spectral classes exhibit variability. The spectral and temporal signatures of the variability are complex and apparently defy simplistic classification which complicates efforts to model the changes. Important questions include understanding if clearings are forming in an otherwise uniform cloud deck or if thermal perturbations, perhaps associated with breaking gravity waves, are responsible. If clouds are responsible how long does it take for the atmospheric thermal profile to relax from a hot cloudy to a cooler cloudless state? If thermal perturbations are responsible then what atmospheric layers are varying? How do the observed variability timescales compare to atmospheric radiative, chemical, and dynamical timescales? I will address such questions by presenting modeling results for time-varying partly cloudy atmospheres and explore the importance of various atmospheric processes over the relevant timescales for brown dwarfs of a range of effective temperatures. Regardless of the origin of the observed variability, the complexity seen in the atmospheres of the field dwarfs hints at the variability that we may encounter in the next few years in directly imaged young Jupiters. Thus understanding the nature of variability in the field dwarfs, including sensitivity to gravity and metallicity, is of particular importance for exoplanet characterization.

An integrative time-varying frequency detection and channel sounding method for dynamic plasma sheath

Science.gov (United States)

Shi, Lei; Yao, Bo; Zhao, Lei; Liu, Xiaotong; Yang, Min; Liu, Yanming

2018-01-01

The plasma sheath-surrounded hypersonic vehicle is a dynamic and time-varying medium and it is almost impossible to calculate time-varying physical parameters directly. The in-fight detection of the time-varying degree is important to understand the dynamic nature of the physical parameters and their effect on re-entry communication. In this paper, a constant envelope zero autocorrelation (CAZAC) sequence based on time-varying frequency detection and channel sounding method is proposed to detect the plasma sheath electronic density time-varying property and wireless channel characteristic. The proposed method utilizes the CAZAC sequence, which has excellent autocorrelation and spread gain characteristics, to realize dynamic time-varying detection/channel sounding under low signal-to-noise ratio in the plasma sheath environment. Theoretical simulation under a typical time-varying radio channel shows that the proposed method is capable of detecting time-variation frequency up to 200 kHz and can trace the channel amplitude and phase in the time domain well under -10 dB. Experimental results conducted in the RF modulation discharge plasma device verified the time variation detection ability in practical dynamic plasma sheath. Meanwhile, nonlinear phenomenon of dynamic plasma sheath on communication signal is observed thorough channel sounding result.

Modal Analysis in Periodic, Time-Varying Systems with emphasis to the Coupling between Flexible Rotating Beams and Non-Rotating Flexible Structures

DEFF Research Database (Denmark)

Saracho, C. M.; Santos, Ilmar

2003-01-01

The analysis of dynamical response of a system built by a non-rotating structure coupled to flexible rotating beams is the purpose of this work. The effect of rotational speed upon the beam natural frequencies is well-known, so that an increase in the angular speeds leads to an increase in beam...... natural frequencies, the so-called centrifugal stiffening. The equations of motion of such a global system present matrices with time-depending coefficients, which vary periodically with the angular rotor speed, and introduce parametric vibrations into the system response. The principles of modal analysis...... for time-invariant linear systems are expanded to investigate time-varying systems. Concepts as eigenvalues and eigenvectors, which in this special case are also time-varying, are used to analyse the dynamical response of global system. The time-varying frequencies and modes are also illustrated....

Nano-Scale Positioning Design with Piezoelectric Materials

Directory of Open Access Journals (Sweden)

Yung Yue Chen

2017-12-01

Full Text Available Piezoelectric materials naturally possess high potential to deliver nano-scale positioning resolution; hence, they are adopted in a variety of engineering applications widely. Unfortunately, unacceptable positioning errors always appear because of the natural hysteresis effect of the piezoelectric materials. This natural property must be mitigated in practical applications. For solving this drawback, a nonlinear positioning design is proposed in this article. This nonlinear positioning design of piezoelectric materials is realized by the following four steps: 1. The famous Bouc–Wen model is utilized to present the input and output behaviors of piezoelectric materials; 2. System parameters of the Bouc–Wen model that describe the characteristics of piezoelectric materials are simultaneously identified with the particle swam optimization method; 3. Stability verification for the identified Bouc–Wen model; 4. A nonlinear feedback linearization control design is derived for the nano-scale positioning design of the piezoelectric material, mathematically. One important contribution of this investigation is that the positioning error between the output displacement of the controlled piezoelectric materials and the desired trajectory in nano-scale level can be proven to converge to zero asymptotically, under the effect of the hysteresis.

Use of a vibrating plate to enhance natural convection cooling of a discrete heat source in a vertical channel

Energy Technology Data Exchange (ETDEWEB)

Florio, L.A.; Harnoy, A. [Department of Mechanical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102 (United States)

2007-09-15

A numerical investigation was conducted into an alternative method of natural convection enhancement by the transverse oscillations of a thin short plate, strategically positioned in close proximity to a rectangular heat source. The heat source is attached to a mounting board in a vertical channel. Two-dimensional laminar flow finite element studies were carried out with the oscillation parameters, the oscillating plate-heat source mean clearance spacing, and the oscillating plate position varied. Significant cooling was found for displacement amplitudes of at least one-third of the mean clearance together with frequencies (Re/{radical}(Gr)) of over 2{pi} with the displacement being more critical to the cooling level. For the parameters investigated, up to a 52% increase in the local heat transfer coefficient relative to standard natural convection was obtained. The results indicate that this method can serve as a feasible, simpler, more energy and space efficient alternative to common methods of cooling for low power dissipating devices operating at conditions just beyond the reach of pure natural convection. (author)

Tracking of [{sup 18}F]FDG-labeled natural killer cells to HER2/neu-positive tumors

Energy Technology Data Exchange (ETDEWEB)

Meier, Reinhard [Department of Radiology, University of California San Francisco (United States)], E-mail: reinhardt.meier@gmail.com; Piert, Morand [Department of Radiology, Division of Nuclear Medicine, University of Michigan (United States); Piontek, Guido; Rudelius, Martina [Institute of Pathology, Klinikum rechts der Isar, Technische Universitaet Muenchen (Germany); Oostendorp, Robert A. [3rd Department of Internal Medicine, Klinikum rechts der Isar, Technische Universitaet Muenchen (Germany); Senekowitsch-Schmidtke, Reingard [Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universitaet Muenchen (Germany); Henning, Tobias D. [Department of Radiology, University of California San Francisco (United States); Wels, Winfried S.; Uherek, Christoph [Chemotherapeutisches Forschungsinstitut, Georg-Speyer-Haus, Frankfurt am Main (Germany); Rummeny, Ernst J. [Department of Radiology, Klinikum rechts der Isar, Technische Universitaet Muenchen (Germany); Daldrup-Link, Heike E. [Department of Radiology, University of California San Francisco (United States)

2008-07-15

Introduction: The objective of this study was to label the human natural killer (NK) cell line NK-92 with [{sup 18}F]fluoro-deoxy-glucose (FDG) for subsequent in vivo tracking to HER2/neu-positive tumors. Methods: NK-92 cells were genetically modified to NK-92-scFv(FRP5)-zeta cells, which express a chimeric antigen receptor that is specific to the tumor-associated ErbB2 (HER2/neu) antigen. NK-92 and NK-92-scFv(FRP5)-zeta cells were labeled with [{sup 18}F]FDG by simple incubation at different settings. Labeling efficiency was evaluated by a gamma counter. Subsequently, [{sup 18}F]FDG-labeled parental NK-92 or NK-92-scFv(FRP5)-zeta cells were intravenously injected into mice with implanted HER2/neu-positive NIH/3T3 tumors. Radioactivity in tumors was quantified by digital autoradiography and correlated with histopathology. Results: The NK-92 and NK-92-scFv(FRP5)-zeta cells could be efficiently labeled with [{sup 18}F]FDG by simple incubation. Optimal labeling efficiencies (80%) were achieved using an incubation period of 60 min and additional insulin (10 IU/ml). After injection of 5x10{sup 6} [{sup 18}F]FDG-labeled NK-92-scFv(FRP5)-zeta cells into tumor-bearing mice, digital autoradiography showed an increased uptake of radioactivity in HER2/neu-positive tumors at 60 min postinjection. Conversely, injection of 5x10{sup 6} NK-92 cells not directed against HER2/neu receptors did not result in increased uptake of radioactivity in the tumors. Histopathology confirmed an accumulation of the NK-92-scFv(FRP5)-zeta cells, but not the parental NK cells, in tumor tissues. Conclusion: The human NK cell line NK-92 can be directed against HER2/neu antigens by genetic modification. The genetically modified NK cells can be efficiently labeled with [{sup 18}F]FDG, and the accumulation of these labeled NK cells in HER2/neu-positive tumors can be monitored with autoradiography.

Free Vibration Behavior of a Gradient Elastic Beam with Varying Cross Section

Directory of Open Access Journals (Sweden)

Mustafa Özgür Yayli

2014-01-01

Full Text Available Based on strain gradient elasticity theory, a finite element procedure is proposed for computation of natural frequencies for the microbeams of constant width and linear varying depth. Weak form formulation of the equation of motion is obtained first as in common classical finite element procedure in terms of various kinds of boundary conditions. Gradient elastic shape functions are used for interpolating deflection inside a finite element. Stiffness and mass matrices are then calculated to solve the microbeam eigen value problem. A solution for natural frequencies is obtained using characteristic equation of microbeam in gradient elasticity. The results are given in a series of figures and compared with their classical counterparts. The effect of various slope values on the natural frequencies are examined in some numerical examples. Comparison with the classical elasticity theory is also performed to verify the present study.

Navigation performance in virtual environments varies with fractal dimension of landscape.

Science.gov (United States)

Juliani, Arthur W; Bies, Alexander J; Boydston, Cooper R; Taylor, Richard P; Sereno, Margaret E

2016-09-01

Fractal geometry has been used to describe natural and built environments, but has yet to be studied in navigational research. In order to establish a relationship between the fractal dimension (D) of a natural environment and humans' ability to navigate such spaces, we conducted two experiments using virtual environments that simulate the fractal properties of nature. In Experiment 1, participants completed a goal-driven search task either with or without a map in landscapes that varied in D. In Experiment 2, participants completed a map-reading and location-judgment task in separate sets of fractal landscapes. In both experiments, task performance was highest at the low-to-mid range of D, which was previously reported as most preferred and discriminable in studies of fractal aesthetics and discrimination, respectively, supporting a theory of visual fluency. The applicability of these findings to architecture, urban planning, and the general design of constructed spaces is discussed.

Positive valence music restores executive control over sustained attention.

Science.gov (United States)

Baldwin, Carryl L; Lewis, Bridget A

2017-01-01

Music sometimes improves performance in sustained attention tasks. But the type of music employed in previous investigations has varied considerably, which can account for equivocal results. Progress has been hampered by lack of a systematic database of music varying in key characteristics like tempo and valence. The aims of this study were to establish a database of popular music varying along the dimensions of tempo and valence and to examine the impact of music varying along these dimensions on restoring attentional resources following performance of a sustained attention to response task (SART) vigil. Sixty-nine participants rated popular musical selections that varied in valence and tempo to establish a database of four musical types: fast tempo positive valence, fast tempo negative valence, slow tempo positive valence, and slow tempo negative valence. A second group of 89 participants performed two blocks of the SART task interspersed with either no break or a rest break consisting of 1 of the 4 types of music or silence. Presenting positive valence music (particularly of slow tempo) during an intermission between two successive blocks of the SART significantly decreased miss rates relative to negative valence music or silence. Results support an attentional restoration theory of the impact of music on sustained attention, rather than arousal theory and demonstrate a means of restoring sustained attention. Further, the results establish the validity of a music database that will facilitate further investigations of the impact of music on performance.

Position of the American Dietetic Association: food and nutrition professionals can implement practices to conserve natural resources and support ecological sustainability.

Science.gov (United States)

Harmon, Alison H; Gerald, Bonnie L

2007-06-01

It is the position of the American Dietetic Association to encourage environmentally responsible practices that conserve natural resources, minimize the quantity of waste generated, and support the ecological sustainability of the food system-the process of food production, transformation, distribution, access, and consumption. Registered dietitians and dietetic technicians, registered, play various roles in the food system and work in settings where efforts to conserve can have significant effects. Natural resources that provide the foundation for the food system include biodiversity, soil, land, energy, water, and air. A food system that degrades or depletes its resource base is not sustainable. Making wise food purchases and food management decisions entails understanding the external costs of food production and foodservice and how these external costs affect food system sustainability. This position paper provides information, specific action-oriented strategies, and resources to guide registered dietitians and dietetic technicians, registered, in food decision making and professional practice. Food and nutrition professionals also can participate in policy making at the local, state, and national levels, and can support policies that encourage the development of local sustainable food systems. Our actions today have global consequences. Conserving and protecting resources will contribute to the sustainability of the global food system now and in the future.

A new approach for diagnosing type 1 diabetes in autoantibody-positive individuals based on prediction and natural history.

Science.gov (United States)

Sosenko, Jay M; Skyler, Jay S; DiMeglio, Linda A; Beam, Craig A; Krischer, Jeffrey P; Greenbaum, Carla J; Boulware, David; Rafkin, Lisa E; Matheson, Della; Herold, Kevan C; Mahon, Jeffrey; Palmer, Jerry P

2015-02-01

We assessed whether type 1 diabetes (T1D) can be diagnosed earlier using a new approach based on prediction and natural history in autoantibody-positive individuals. Diabetes Prevention Trial-Type 1 (DPT-1) and TrialNet Natural History Study (TNNHS) participants were studied. A metabolic index, the T1D Diagnostic Index60 (Index60), was developed from 2-h oral glucose tolerance tests (OGTTs) using the log fasting C-peptide, 60-min C-peptide, and 60-min glucose. OGTTs with Index60 ≥2.00 and 2-h glucose <200 mg/dL (Ind60+Only) were compared with Index60 <2.00 and 2-h glucose ≥200 mg/dL (2hglu+Only) OGTTs as criteria for T1D. Individuals were assessed for C-peptide loss from the first Ind60+Only OGTT to diagnosis. Areas under receiver operating characteristic curves were significantly higher for Index60 than for the 2-h glucose (P < 0.001 for both DPT-1 and the TNNHS). As a diagnostic criterion, sensitivity was higher for Ind60+Only than for 2hglu+Only (0.44 vs. 0.15 in DPT-1; 0.26 vs. 0.17 in the TNNHS) OGTTs. Specificity was somewhat higher for 2hglu+Only OGTTs in DPT-1 (0.97 vs. 0.91) but equivalent in the TNNHS (0.98 for both). Positive and negative predictive values were higher for Ind60+Only OGTTs in both studies. Postchallenge C-peptide levels declined significantly at each OGTT time point from the first Ind60+Only OGTT to the time of standard diagnosis (range -22 to -34% in DPT-1 and -14 to -27% in the TNNHS). C-peptide and glucose patterns differed markedly between Ind60+Only and 2hglu+Only OGTTs. An approach based on prediction and natural history appears to have utility for diagnosing T1D. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Out-of-plane vibrations of inhomogeneous curved bars having varying cross-sections

International Nuclear Information System (INIS)

Suzuki, Katsuyoshi; Kosawada, Tadashi

1987-01-01

An exact method using power series expansions is presented for solving out-of-plane free vibrations of inhomogeneous curved bars with varying curvatures and cross-sections. Equations of motion and boundary conditions are derived from the stationary conditions of the Lagrangian of curved bars. Natural frequencies and mode shapes are presented for elliptical and circular arc bars having both ends clamped and clamped-free ends. (author)

Natural history of treatment-emergent central sleep apnea on positive airway pressure: A systematic review.

Science.gov (United States)

Nigam, Gaurav; Riaz, Muhammad; Chang, Edward T; Camacho, Macario

2018-01-01

Treatment-emergent central sleep apnea (TECSA) is observed in some patients when they are treated with positive airway pressure (PAP) after significant resolution of the preexisting obstructive events in patients with obstructive sleep apnea. The objective of this study was to systematically review the literature for studies describing the natural history of TECSA. PubMed, Medline, Scopus, Web of Science, and Cochran Library databases were searched through June 29, 2017. Five studies were identified that discussed the natural history of TECSA. TECSA developed in 3.5%-19.8% of PAP-treated patients. Treatment-persistent central sleep apnea (TPCSA), representing protracted periods of PAP therapy-related central apneas, was noted in 14.3%-46.2% of patients with TECSA. Delayed-TECSA (D-TECSA) represents an anomalous TECSA entity appearing weeks to months after initial PAP therapy. D-TECSA was observed in 0.7%-4.2% of OSA patients undergoing PAP treatment (after at least 1 month). In patients with TECSA, a higher apnea-hypopnea index (AHI) and central apnea index at their baseline study or a higher residual AHI at their titration study may be associated with an increased likelihood of conversion to TPCSA. Overall, TECSA developed in 3.5%-19.8% of PAP-treated patients with OSA. The vast majority will experience complete resolution of central apneas over a few weeks to months. Unfortunately, about a third of patients with TECSA may continue to exhibit persistence of central sleep apnea on reevaluation. A small proportion may experience D-TECSA after few weeks to several months of initial exposure to PAP therapy.

Time-varying output performances of piezoelectric vibration energy harvesting under nonstationary random vibrations

Science.gov (United States)

Yoon, Heonjun; Kim, Miso; Park, Choon-Su; Youn, Byeng D.

2018-01-01

Piezoelectric vibration energy harvesting (PVEH) has received much attention as a potential solution that could ultimately realize self-powered wireless sensor networks. Since most ambient vibrations in nature are inherently random and nonstationary, the output performances of PVEH devices also randomly change with time. However, little attention has been paid to investigating the randomly time-varying electroelastic behaviors of PVEH systems both analytically and experimentally. The objective of this study is thus to make a step forward towards a deep understanding of the time-varying performances of PVEH devices under nonstationary random vibrations. Two typical cases of nonstationary random vibration signals are considered: (1) randomly-varying amplitude (amplitude modulation; AM) and (2) randomly-varying amplitude with randomly-varying instantaneous frequency (amplitude and frequency modulation; AM-FM). In both cases, this study pursues well-balanced correlations of analytical predictions and experimental observations to deduce the relationships between the time-varying output performances of the PVEH device and two primary input parameters, such as a central frequency and an external electrical resistance. We introduce three correlation metrics to quantitatively compare analytical prediction and experimental observation, including the normalized root mean square error, the correlation coefficient, and the weighted integrated factor. Analytical predictions are in an excellent agreement with experimental observations both mechanically and electrically. This study provides insightful guidelines for designing PVEH devices to reliably generate electric power under nonstationary random vibrations.

Place attachment and natural environmental risk

DEFF Research Database (Denmark)

Bonaiuto, Marino; Alves, Susana; De Dominicis, Stefano

2016-01-01

Little is known about place attachment affecting natural environmental risk perception and coping. A systematic search of social science databases revealed 31 works (1996–2016) directly addressing place attachment in relation to different types of natural hazard risks (e.g., seismic, volcanic, etc.......). Across different contexts, the research shows: (a) positive and/or negative relationships between place attachment and natural environmental risk perception; (b) positive and/or negative relationships between place attachment and risk coping; and (c) mediating and moderating relationships. In particular......, results show that: (a) highly attached individuals perceive natural environmental risks but underestimate their potential effects; (b) highly attached individuals are unwilling to relocate when facing natural environmental risks and more likely to return to risky areas after a natural environmental...

Behavior of varying-alpha cosmologies

International Nuclear Information System (INIS)

Barrow, John D.; Sandvik, Haavard Bunes; Magueijo, Joao

2002-01-01

We determine the behavior of a time-varying fine structure 'constant' α(t) during the early and late phases of universes dominated by the kinetic energy of changing α(t), radiation, dust, curvature, and lambda, respectively. We show that after leaving an initial vacuum-dominated phase during which α increases, α remains constant in universes such as our own during the radiation era, and then increases slowly, proportional to a logarithm of cosmic time, during the dust era. If the universe becomes dominated by a negative curvature or a positive cosmological constant then α tends rapidly to a constant value. The effect of an early period of de Sitter or power-law inflation is to drive α to a constant value. Various cosmological consequences of these results are discussed with reference to recent observational studies of the value of α from quasar absorption spectra and to the existence of life in expanding universes

Toward an Optimal Position for IVC Filters: Computational Modeling of the Impact of Renal Vein Inflow

Energy Technology Data Exchange (ETDEWEB)

Wang, S L; Singer, M A

2009-07-13

The purpose of this report is to evaluate the hemodynamic effects of renal vein inflow and filter position on unoccluded and partially occluded IVC filters using three-dimensional computational fluid dynamics. Three-dimensional models of the TrapEase and Gunther Celect IVC filters, spherical thrombi, and an IVC with renal veins were constructed. Hemodynamics of steady-state flow was examined for unoccluded and partially occluded TrapEase and Gunther Celect IVC filters in varying proximity to the renal veins. Flow past the unoccluded filters demonstrated minimal disruption. Natural regions of stagnant/recirculating flow in the IVC are observed superior to the bilateral renal vein inflows, and high flow velocities and elevated shear stresses are observed in the vicinity of renal inflow. Spherical thrombi induce stagnant and/or recirculating flow downstream of the thrombus. Placement of the TrapEase filter in the suprarenal vein position resulted in a large area of low shear stress/stagnant flow within the filter just downstream of thrombus trapped in the upstream trapping position. Filter position with respect to renal vein inflow influences the hemodynamics of filter trapping. Placement of the TrapEase filter in a suprarenal location may be thrombogenic with redundant areas of stagnant/recirculating flow and low shear stress along the caval wall due to the upstream trapping position and the naturally occurring region of stagnant flow from the renal veins. Infrarenal vein placement of IVC filters in a near juxtarenal position with the downstream cone near the renal vein inflow likely confers increased levels of mechanical lysis of trapped thrombi due to increased shear stress from renal vein inflow.

Dependence of fluence errors in dynamic IMRT on leaf-positional errors varying with time and leaf number

International Nuclear Information System (INIS)

Zygmanski, Piotr; Kung, Jong H.; Jiang, Steve B.; Chin, Lee

2003-01-01

In d-MLC based IMRT, leaves move along a trajectory that lies within a user-defined tolerance (TOL) about the ideal trajectory specified in a d-MLC sequence file. The MLC controller measures leaf positions multiple times per second and corrects them if they deviate from ideal positions by a value greater than TOL. The magnitude of leaf-positional errors resulting from finite mechanical precision depends on the performance of the MLC motors executing leaf motions and is generally larger if leaves are forced to move at higher speeds. The maximum value of leaf-positional errors can be limited by decreasing TOL. However, due to the inherent time delay in the MLC controller, this may not happen at all times. Furthermore, decreasing the leaf tolerance results in a larger number of beam hold-offs, which, in turn leads, to a longer delivery time and, paradoxically, to higher chances of leaf-positional errors (≤TOL). On the other end, the magnitude of leaf-positional errors depends on the complexity of the fluence map to be delivered. Recently, it has been shown that it is possible to determine the actual distribution of leaf-positional errors either by the imaging of moving MLC apertures with a digital imager or by analysis of a MLC log file saved by a MLC controller. This leads next to an important question: What is the relation between the distribution of leaf-positional errors and fluence errors. In this work, we introduce an analytical method to determine this relation in dynamic IMRT delivery. We model MLC errors as Random-Leaf Positional (RLP) errors described by a truncated normal distribution defined by two characteristic parameters: a standard deviation σ and a cut-off value Δx 0 (Δx 0 ∼TOL). We quantify fluence errors for two cases: (i) Δx 0 >>σ (unrestricted normal distribution) and (ii) Δx 0 0 --limited normal distribution). We show that an average fluence error of an IMRT field is proportional to (i) σ/ALPO and (ii) Δx 0 /ALPO, respectively, where

Viewing nature scenes positively affects recovery of autonomic function following acute-mental stress.

Science.gov (United States)

Brown, Daniel K; Barton, Jo L; Gladwell, Valerie F

2013-06-04

A randomized crossover study explored whether viewing different scenes prior to a stressor altered autonomic function during the recovery from the stressor. The two scenes were (a) nature (composed of trees, grass, fields) or (b) built (composed of man-made, urban scenes lacking natural characteristics) environments. Autonomic function was assessed using noninvasive techniques of heart rate variability; in particular, time domain analyses evaluated parasympathetic activity, using root-mean-square of successive differences (RMSSD). During stress, secondary cardiovascular markers (heart rate, systolic and diastolic blood pressure) showed significant increases from baseline which did not differ between the two viewing conditions. Parasympathetic activity, however, was significantly higher in recovery following the stressor in the viewing scenes of nature condition compared to viewing scenes depicting built environments (RMSSD; 50.0 ± 31.3 vs 34.8 ± 14.8 ms). Thus, viewing nature scenes prior to a stressor alters autonomic activity in the recovery period. The secondary aim was to examine autonomic function during viewing of the two scenes. Standard deviation of R-R intervals (SDRR), as change from baseline, during the first 5 min of viewing nature scenes was greater than during built scenes. Overall, this suggests that nature can elicit improvements in the recovery process following a stressor.

Probing photo-ionization: simulations of positive streamers in varying N2:O2 mixtures

OpenAIRE

Wormeester, G; Pancheshnyi, S; Luque, A A; Nijdam, S Sander; Ebert, UM Ute

2010-01-01

htmlabstractPhoto-ionization is the accepted mechanism for the propagation of positive streamers in air though the parameters are not very well known; the efficiency of this mechanism largely depends on the presence of both nitrogen and oxygen. But experiments show that streamer propagation is amazingly robust against changes of the gas composition; even for pure nitrogen with impurity levels below 1 ppm streamers propagate essentially with the same velocity as in air, but their minimal diame...

Effects of window position on natural cross ventilation in vernacular ...

African Journals Online (AJOL)

Among the most effective architectures is vernacular architecture of Mazandaran whose incorporation in nature is so delicate that appears to be an essential part of it. Paying more attention to vernacular architecture and promoting it can be helpful in reducing energy consumption. Increasing use of fossil fuels in heating and ...

Event-driven control of a speed varying digital displacement machine

DEFF Research Database (Denmark)

Pedersen, Niels Henrik; Johansen, Per; Andersen, Torben O.

2017-01-01

. The controller synthesis is carried out as a discrete optimal deterministic problem with full state feedback. Based on a linear analysis of the feedback control system, stability is proven in a pre-specified operation region. Simulation of a non-linear evaluation model with the controller implemented shows great...... be treated as a Discrete Linear Time Invariant control problem with synchronous sampling rate. To make synchronous linear control theory applicable for a variable speed digital displacement machine, a method based on event-driven control is presented. Using this method, the time domain differential equations...... are converted into the spatial (position) domain to obtain a constant sampling rate and thus allowing for use of classical control theory. The method is applied to a down scaled digital fluid power motor, where the motor speed is controlled at varying references under varying pressure and load torque conditions...

Instrumented Glove Measures Positions Of Fingers

Science.gov (United States)

Bozeman, Richard J., Jr.

1993-01-01

Glove instrumented with flat membrane potentiometers to obtain crude measurements of relative positions of fingers. Resistance of each potentiometer varies with position of associated finger; translator circuit connected to each potentiometer converts analog reading to 1 of 10 digital levels. Digitized outputs from all fingers fed to indicating, recording, and/or data-processing equipment. Gloves and circuits intended for use in biomedical research, training in critical manual tasks, and other specialized applications.

Development of phenanthrene catabolism in natural and artificial soils

International Nuclear Information System (INIS)

Rhodes, Angela H.; Hofman, Jakub; Semple, Kirk T.

2008-01-01

The characteristics of natural soils often vary from those of artificial soil (e.g. OECD), which may lead to substantial differences in the bioavailability of test substances. The aim of this investigation was to characterise the development of phenanthrene catabolism in both natural and artificial soils with varying total organic carbon (TOC) content after 1, 14, 42 and 84 d soil-phenanthrene contact time. Indigenous catabolic activity was measured via the addition of 14 C-phenanthrene using the respirometric soil slurry assay. Notably, the lag phases, fastest rates and total extents of 14 C-phenanthrene degradation were relatively comparable in soils with similar TOC content after 1 d contact time. However, natural soils generally exhibited significantly shorter lag phases, faster rates and higher extents of mineralisation, than their artificial counterparts after 42 and 84 d contact time. Such findings suggest that the extrapolation of results from artificial soils to real/natural soils may not be straightforward. - Natural and artificial soils display different phenanthrene mineralisation profiles suggesting that the extrapolation of results from artificial soils to real/natural soils may not be straightforward

Natural gas consumption and economic growth: Are we ready to natural gas price liberalization in Iran?

International Nuclear Information System (INIS)

Heidari, Hassan; Katircioglu, Salih Turan; Saeidpour, Lesyan

2013-01-01

This paper examines the relationship between natural gas consumption and economic growth in Iran within a multivariate production model. We also investigate the effects of natural gas price on its consumption and economic growth using a demand side model. The paper employs bounds test approach to level relationship over the period of 1972–007. We find evidence of bidirectional positive relationship between natural gas consumption and economic growth in short-run and long-run, based on the production model. The findings also suggest that real GDP growth and natural gas have positive and negative impacts on gross fixed capital formation, respectively. Employment, however, was found to have negative but insignificant impact on gross fixed capital formation. Moreover, the estimation results of demand side model suggest that natural gas price has negative and significant impact on natural gas consumption only in the long-run, though there is insignificant impact on economic growth. These results imply that the Iranian government's decision for natural gas price liberalization has the adverse effects on economic growth and policy makers should be cautious in doing this policy. - Highlights: • Iran has been considered as a major natural gas producer in the world. • This paper examines the relationship between gas consumption and growth in Iran. • Positive impact of gas consumption on growth has been obtained. • The paper finds that gas consumption and income reinforce each other in Iran. • Natural gas price has also negative and significant impact on natural gas consumption in Iran

Positive health effects of the natural outdoor environment in typical populations in different regions in Europe (PHENOTYPE): a study programme protocol.

Science.gov (United States)

Nieuwenhuijsen, Mark J; Kruize, Hanneke; Gidlow, Christopher; Andrusaityte, Sandra; Antó, Josep Maria; Basagaña, Xavier; Cirach, Marta; Dadvand, Payam; Danileviciute, Asta; Donaire-Gonzalez, David; Garcia, Judith; Jerrett, Michael; Jones, Marc; Julvez, Jordi; van Kempen, Elise; van Kamp, Irene; Maas, Jolanda; Seto, Edmund; Smith, Graham; Triguero, Margarita; Wendel-Vos, Wanda; Wright, John; Zufferey, Joris; van den Hazel, Peter Jan; Lawrence, Roderick; Grazuleviciene, Regina

2014-04-16

Growing evidence suggests that close contact with nature brings benefits to human health and well-being, but the proposed mechanisms are still not well understood and the associations with health remain uncertain. The Positive Health Effects of the Natural Outdoor environment in Typical Populations in different regions in Europe (PHENOTYPE) project investigates the interconnections between natural outdoor environments and better human health and well-being. The PHENOTYPE project explores the proposed underlying mechanisms at work (stress reduction/restorative function, physical activity, social interaction, exposure to environmental hazards) and examines the associations with health outcomes for different population groups. It implements conventional and new innovative high-tech methods to characterise the natural environment in terms of quality and quantity. Preventive as well as therapeutic effects of contact with the natural environment are being covered. PHENOTYPE further addresses implications for land-use planning and green space management. The main innovative part of the study is the evaluation of possible short-term and long-term associations of green space and health and the possible underlying mechanisms in four different countries (each with quite a different type of green space and a different use), using the same methodology, in one research programme. This type of holistic approach has not been undertaken before. Furthermore there are technological innovations such as the use of remote sensing and smartphones in the assessment of green space. The project will produce a more robust evidence base on links between exposure to natural outdoor environment and human health and well-being, in addition to a better integration of human health needs into land-use planning and green space management in rural as well as urban areas.

Connections with nature and environmental behaviors.

Science.gov (United States)

Geng, Liuna; Xu, Jingke; Ye, Lijuan; Zhou, Wenjun; Zhou, Kexin

2015-01-01

The influence of environmental attitudes on environmental behaviors has long been discussed. However, few studies have addressed the foundation of such attitudes. In the present study, we explored primitive belief underlying environmental attitudes, i.e., connections with nature, and its relationship with pro-environmental behaviors. Specifically, we used scales, a computerized Implicit Association Test, and a situational simulation experiment to examine both explicit and implicit connections with nature, both deliberate and spontaneous environmental behaviors, and to find correlations between environmental connectedness and environmental behaviors. Results showed that explicit connectedness was positively correlated with deliberate environmental behaviors, while implicit connectedness was positively correlated with spontaneous environmental behaviors. Additionally, explicit and implicit connectedness was independent of each other. In conclusion, the current study confirms the positive role played by connections with nature in promoting environmental behavior, and accordingly suggests means to encourage pro-environmental behavior by enhancing people's connectedness to nature.

Unnaturalised racial naturalism.

Science.gov (United States)

Hochman, Adam

2014-06-01

Quayshawn Spencer (2014) misunderstands my treatment of racial naturalism. I argued that racial naturalism must entail a strong claim, such as "races are subspecies", if it is to be a substantive position that contrasts with anti-realism about biological race. My recognition that not all race naturalists make such a strong claim is evident throughout the article Spencer reviews (Hochman, 2013a). Spencer seems to agree with me that there are no human subspecies, and he endorses a weaker form of racial naturalism. However, he supports his preferred version of 'racial naturalism' with arguments that are not well described as 'naturalistic'. I argue that Spencer offers us an unnaturalised racial naturalism. Copyright © 2014 Elsevier Ltd. All rights reserved.

Natural Hazards, Second Edition

Science.gov (United States)

Rouhban, Badaoui

Natural disaster loss is on the rise, and the vulnerability of the human and physical environment to the violent forces of nature is increasing. In many parts of the world, disasters caused by natural hazards such as earthquakes, floods, landslides, drought, wildfires, intense windstorms, tsunami, and volcanic eruptions have caused the loss of human lives, injury, homelessness, and the destruction of economic and social infrastructure. Over the last few years, there has been an increase in the occurrence, severity, and intensity of disasters, culminating with the devastating tsunami of 26 December 2004 in South East Asia.Natural hazards are often unexpected or uncontrollable natural events of varying magnitude. Understanding their mechanisms and assessing their distribution in time and space are necessary for refining risk mitigation measures. This second edition of Natural Hazards, (following a first edition published in 1991 by Cambridge University Press), written by Edward Bryant, associate dean of science at Wollongong University, Australia, grapples with this crucial issue, aspects of hazard prediction, and other issues. The book presents a comprehensive analysis of different categories of hazards of climatic and geological origin.

Varying occurrence of extended-spectrum beta-lactamase bacteria among three produce types

KAUST Repository

Toh, Benjamin E. W.

2017-07-07

A monitoring effort that spanned across 1.5 years was conducted to examine three types of produce-associated microbiota. The average amount of antibiotic-resistant bacteria recovered from lettuce, tomato, and cucumber was 1.02 × 1010, 2.05 × 107, and 4.78 × 109 cells per 50 g of each produce, respectively. A total of 480 bacterial isolates were obtained and identified from their 16S rRNA genes, revealing isolates that were ubiquitously recovered from all three types of produce. However, sporadic presence of Klebsiella pneumoniae and Acinetobacter baumannii was detected on lettuce and cucumbers but not tomatoes. End-point PCR revealed that the K. pneumoniae and A. baumannii isolates were positive for genes encoding extended spectrum beta-lactamase. Whole genome sequencing of two of the K. pneumoniae isolates further suggested the presence of the blaCTX-M-15 gene in a conjugative plasmid, as well as other antibiotic resistance genes and virulence-associated traits in either conjugative plasmids or the chromosomal genome. Quantitative microbial risk assessment indicated varying levels of ingestion risk associated with different types of produce. In particular, the risk arising from ESBL-positive K. pneumoniae in lettuce, but not in cucumbers or tomatoes, was higher than the acceptable annual risk of 10−4. Practical applications Three types of vegetables were sampled and evaluated over 1.5 years to determine differences in their associated bacterial isolates. Particular emphasis was placed on identifying pathogenic strains that were positive for extended spectrum beta-lactamase (ESBL). Quantitative estimates of the microbial risk associated with the ESBL-positive pathogens showed that different produce types may incur varying levels of ingestion risk. Most of the currently reported ESBL-positive bacterial isolates have been identified in nosocomial environments. However, the carriage of such drug-resistant bacteria in vegetables suggests a possible connection

Biomass yielding potential of naturally regenerated Prosopis juliflora tree stands at three varied ecosystems in southern districts of Tamil Nadu, India.

Science.gov (United States)

Saraswathi, K; Chandrasekaran, S

2016-05-01

Fuel energy demand is of great concern in recent times due to the depletion of fossil fuel resources. Biomass serves as widely available primary renewable energy source. Hence, a study was performed to assess the above-ground biomass yielding capability of fuel wood tree Prosopis juliflora in three varied ecosystems viz., coastal, fallow land and riparian ecosystems in southern districts of Tamil Nadu. The results showed that the biomass production potential and above-ground net primary productivity of P. juliflora depend on the age of the tree stands and the nature of ecosystem. A higher biomass yield was observed for P. juliflora trees with 5 to 10 years old when compared to less than 5 years of their age. Among the three ecosystems, the maximum biomass production was recorded in riparian ecosystem. The stands with less than 5-year-old P. juliflora trees gave 1.40 t/ha, and 5- to 10-year-old tree stands produced 27.69 t/ha in riparian ecosystem. Above-ground net primary productivity of both the age groups was high in fallow land ecosystem. In riparian ecosystem, the wood showed high density and low sulphur content than the other two ecosystems. Hence, P. juliflora biomass can serve as an environmentally and economically feasible fuel as well as their utilization proffers an effective means to control its invasiveness.

Positive aspects of menopause: a qualitative study

DEFF Research Database (Denmark)

Hvas, L

2001-01-01

As a part of a larger study, "Menopause described from the woman's perspective", it has been the aim to explore whether women have any positive experiences in relation to menopause, and if so, the nature of these experiences.......As a part of a larger study, "Menopause described from the woman's perspective", it has been the aim to explore whether women have any positive experiences in relation to menopause, and if so, the nature of these experiences....

Regionally-varying and regionally-uniform electricity pricing policies compared across four usage categories

International Nuclear Information System (INIS)

Cho, Seong-Hoon; Kim, Taeyoung; Kim, Hyun Jae; Park, Kihyun; Roberts, Roland K.

2015-01-01

The objective of our research is to predict how electricity demand varies spatially between status quo regionally-uniform electricity pricing and hypothetical regionally-varying electricity pricing across usage categories. We summarize the empirical results of a case study of electricity demand in South Korea with three key findings and their related implications. First, the price elasticities of electricity demand differ across usage categories. Specifically, electricity demands for manufacturing and retail uses are price inelastic and close to unit elastic, respectively, while those for agricultural and residential uses are not statistically significant. This information is important in designing energy policy, because higher electricity prices could reduce electricity demands for manufacturing and retail uses, resulting in slower growth in those sectors. Second, spatial spillovers in electricity demand vary across uses. Understanding the spatial structure of electricity demand provides useful information to energy policy makers for anticipating changes in demand across regions via regionally-varying electricity pricing for different uses. Third, simulation results suggest that spatial variations among electricity demands by usage category under a regionally-varying electricity-pricing policy differ from those under a regionally-uniform electricity-pricing policy. Differences in spatial changes between the policies provide information for developing a realistic regionally-varying electricity-pricing policy according to usage category. - Highlights: • We compare regionally-varying and regionally-uniform electricity pricing policies. • We summarize empirical results of a case study of electricity demand in South Korea. • We confirm that spatial spillovers in electricity demands vary across different uses. • We find positive spatial spillovers in the manufacturing and residential sectors. • Our methods help policy makers evaluate regionally-varying pricing

NATURAL LAW, HISTORY AND POLITICS LEY NATURAL, HISTORIA Y POLÍTICA LEI NATURAL, HISTÓRIA E POLÍTICA

Directory of Open Access Journals (Sweden)

James Drane

2002-01-01

Full Text Available The basic philosophical vision and ethical principles of Catholic Natural Law claim universality. Natural Law thinking aspires to objectivity and universality and at the same time is open to the continuing influence from history and politics. The background principles of positive law historically go by the name of Natural Law. Suffering and injustice contribute to a vision both of the structure of human existence and of what we mean by humane law and ethics. When we confront a cultural crisis, Natural Law, looks not to the past but to the future. Few people today talk of the ethical dimensions of social realities in terms of Natural Law. This is true both in the Church and in the State. In bioethics, the principles rooted in the universal structure of human life have to provide direction and regulations on the playing field of contemporary life and medicine. A liberal Catholic perspective tries to keep in play the universal and the particular aspects of Natural Law reasoningLa visión filosófica básica y los principios éticos de la Ley Natural Católica demandan universalidad. El pensamiento de la Ley Natural aspira a la objetividad y universalidad y, al mismo tiempo, está abierto a la continua influencia de la historia y la política. Los principios que yacen en la base de la ley positiva históricamente reciben el nombre de Ley Natural. El sufrimiento y la injusticia contribuyen a una visión, tanto de la estructura de la existencia humana como de lo que entendemos por una ley y una ética humanas. Cuando enfrentamos una crisis cultural, la Ley Natural no mira hacia el pasado sino que hacia el futuro. Es poca la gente que hoy en día habla de las dimensiones éticas de las realidades sociales en términos de Ley Natural. Esto vale tanto para la Iglesia como para el Estado. En bioética, los principios enraizados en la estructura universal de la vida humana tienen que proporcionar dirección y regulación en el campo de juego de la vida y

Self-tuning control studies of the plasma vertical position problem

International Nuclear Information System (INIS)

Zheng, Guang Lin; Wellstead, P.E.; Browne, M.L.

1993-01-01

The plasma vertical position system in a tokamak device can be open-loop unstable with time-varying dynamics, such that the instability increases with system dynamical changes. Time-varying unstable dynamics makes the plasma vertical position a particularly difficult one to control with traditional fixed-coefficient controllers. A self-tuning technique offers a new solution of the plasma vertical position control problem by an adaptive control approach. Specifically, the self-tuning controller automatically tunes the controller parameters without an a priori knowledge of the system dynamics and continuously tracks dynamical changes within the system, thereby providing the system with auto-tuning and adaptive tuning capabilities. An overview of the self-tuning methods is given, and their applicability to a simulation of the Joint European Torus (JET) vertical plasma positions system is illustrated. Specifically, the applicability of pole-assignment and generalized predictive control self-tuning methods to the vertical plasma position system is demonstrated. 26 refs., 16 figs., 1 tab

Natural Disasters and Nontuberculous Mycobacteria

Science.gov (United States)

Bernhard, Jon N.; Chan, Edward D.

2015-01-01

Infectious diseases acquired by survivors of large-scale natural disasters complicate the recovery process. During events such as tsunamis, hurricanes, earthquakes, and tornados and well into the recovery period, victims often are exposed to water-soil mixtures that have relocated with indigenous microbes. Because nontuberculous mycobacteria (NTM) are ubiquitous in water and soil, there is potential for increased exposure to these organisms during natural disasters. In this hypothesis-driven commentary, we discuss the rise in NTM lung disease and natural disasters and examine the geographic overlap of NTM infections and disaster frequencies in the United States. Moreover, we show an increased number of positive NTM cultures from Louisiana residents in the years following three of the relatively recent epic hurricanes and posit that such natural disasters may help to drive the increased number of NTM infections. Finally, we advocate for increased environmental studies and surveillance of NTM infections before and after natural disasters. PMID:25644904

Modeling Nonstationary Emotion Dynamics in Dyads using a Time-Varying Vector-Autoregressive Model.

Science.gov (United States)

Bringmann, Laura F; Ferrer, Emilio; Hamaker, Ellen L; Borsboom, Denny; Tuerlinckx, Francis

2018-01-01

Emotion dynamics are likely to arise in an interpersonal context. Standard methods to study emotions in interpersonal interaction are limited because stationarity is assumed. This means that the dynamics, for example, time-lagged relations, are invariant across time periods. However, this is generally an unrealistic assumption. Whether caused by an external (e.g., divorce) or an internal (e.g., rumination) event, emotion dynamics are prone to change. The semi-parametric time-varying vector-autoregressive (TV-VAR) model is based on well-studied generalized additive models, implemented in the software R. The TV-VAR can explicitly model changes in temporal dependency without pre-existing knowledge about the nature of change. A simulation study is presented, showing that the TV-VAR model is superior to the standard time-invariant VAR model when the dynamics change over time. The TV-VAR model is applied to empirical data on daily feelings of positive affect (PA) from a single couple. Our analyses indicate reliable changes in the male's emotion dynamics over time, but not in the female's-which were not predicted by her own affect or that of her partner. This application illustrates the usefulness of using a TV-VAR model to detect changes in the dynamics in a system.

Prevention of Marine Biofouling Using the Natural Allelopathic Compound Batatasin-III and Synthetic Analogues.

Science.gov (United States)

Moodie, Lindon W K; Trepos, Rozenn; Cervin, Gunnar; Bråthen, Kari Anne; Lindgård, Bente; Reiersen, Rigmor; Cahill, Patrick; Pavia, Henrik; Hellio, Claire; Svenson, Johan

2017-07-28

The current study reports the first comprehensive evaluation of a class of allelopathic terrestrial natural products as antifoulants in a marine setting. To investigate the antifouling potential of the natural dihydrostilbene scaffold, a library of 22 synthetic dihydrostilbenes with varying substitution patterns, many of which occur naturally in terrestrial plants, were prepared and assessed for their antifouling capacity. The compounds were evaluated in an extensive screen against 16 fouling marine organisms. The dihydrostilbene scaffold was shown to possess powerful general antifouling effects against both marine microfoulers and macrofoulers with inhibitory activities at low concentrations. The species of microalgae examined displayed a particular sensitivity toward the evaluated compounds at low ng/mL concentrations. It was shown that several of the natural and synthetic compounds exerted their repelling activities via nontoxic and reversible mechanisms. The activities of the most active compounds such as 3,5-dimethoxybibenzyl (5), 3,4-dimethoxybibenzyl (9), and 3-hydroxy-3',4,5'-trimethoxybibenzyl (20) were comparable to the commercial antifouling booster biocide Sea-nine, which was employed as a positive control. The investigation of terrestrial allelopathic natural products to counter marine fouling represents a novel strategy for the design of "green" antifouling technologies, and these compounds offer a potential alternative to traditional biocidal antifoulants.

PCA-based detection of damage in time-varying systems

Science.gov (United States)

Bellino, A.; Fasana, A.; Garibaldi, L.; Marchesiello, S.

2010-10-01

When performing Structural Health Monitoring, it is well known that the natural frequencies do not depend only on the damage but also on environmental conditions, such as temperature and humidity. The Principal Component Analysis is used to take this problem into account, because it allows eliminating the effect of external factors. The purpose of the present work is to show that this technique can be successfully used not only for time-invariant systems, but also for time-varying ones. Referring to the latter, one of the most studied systems which shows these characteristics is the bridge with crossing loads, such as the case of the railway bridge studied in present paper; in this case, the mass and the velocity of the train can be considered as "environmental" factors.This paper, after a brief description of the PCA method and one example of its application on time-invariant systems, presents the great potentialities of the methodology when applied to time-varying systems. The results show that this method is able to better detect the presence of damage and also to properly distinguish among different levels of crack depths.

Sensitivity of ring growth and carbon allocation to climatic variation vary within ponderosa pine trees.

Science.gov (United States)

Kerhoulas, Lucy P; Kane, Jeffrey M

2012-01-01

Most dendrochronological studies focus on cores sampled from standard positions (main stem, breast height), yet vertical gradients in hydraulic constraints and priorities for carbon allocation may contribute to different growth sensitivities with position. Using cores taken from five positions (coarse roots, breast height, base of live crown, mid-crown branch and treetop), we investigated how radial growth sensitivity to climate over the period of 1895-2008 varies by position within 36 large ponderosa pines (Pinus ponderosa Dougl.) in northern Arizona. The climate parameters investigated were Palmer Drought Severity Index, water year and monsoon precipitation, maximum annual temperature, minimum annual temperature and average annual temperature. For each study tree, we generated Pearson correlation coefficients between ring width indices from each position and six climate parameters. We also investigated whether the number of missing rings differed among positions and bole heights. We found that tree density did not significantly influence climatic sensitivity to any of the climate parameters investigated at any of the sample positions. Results from three types of analyses suggest that climatic sensitivity of tree growth varied with position height: (i) correlations of radial growth and climate variables consistently increased with height; (ii) model strength based on Akaike's information criterion increased with height, where treetop growth consistently had the highest sensitivity and coarse roots the lowest sensitivity to each climatic parameter; and (iii) the correlation between bole ring width indices decreased with distance between positions. We speculate that increased sensitivity to climate at higher positions is related to hydraulic limitation because higher positions experience greater xylem tensions due to gravitational effects that render these positions more sensitive to climatic stresses. The low sensitivity of root growth to all climatic variables

Volatility spillover and time-varying conditional correlation between DDGS, corn, and soybean meal markets

NARCIS (Netherlands)

Etienne, Xiaoli L.; Trujillo-Barrera, Andrés; Hoffman, Linwood A.

2017-01-01

We find distiller's dried grains with solubles (DDGS) prices to be positively correlated with both corn and soybean meal prices in the long run. However, neither corn nor soybean meal prices respond to deviations from this long-run relationship. We also identify strong time-varying dynamic

Incidence of centrally positioned nuclei in mouse masticatory muscle fibers

DEFF Research Database (Denmark)

Vilmann, A; Vilmann, H; Kirkeby, S

1989-01-01

Cross-sections of normal digastric, temporalis and masseter muscles from 7- and 30-week-old mice were studied for centrally positioned nuclei. Such nuclei were inhomogeneously distributed throughout each muscle and varied markedly between specimens. The incidence of centrally positioned nuclei in...

Assessment of the quality and quantity of naturally induced antibody responses to EBA175RIII-V in Ghanaian children living in two communities with varying malaria transmission patterns

DEFF Research Database (Denmark)

Abagna, Hamza B; Acquah, Festus K; Okonu, Ruth

2018-01-01

of malaria parasites, which can enhance immune responses against parasite antigens. This study determined the prevalence and relative avidities of naturally induced antibodies to EBA175RIII-VLl in asymptomatic children living in two communities with varying malaria transmission patterns. METHODS: An asexual...... each study site however, children living in Obom had significantly higher EBA175RIII-VLl antibody concentrations than children living in Abura (P 0.05, Mann-Whitney test). Over the course of the study, the relative antibody avidities of EBA175RIII-VLl IgG antibodies were similar within and between......BACKGROUND: Recent global reports on malaria suggest significant decrease in disease severity and an increase in control interventions in many malaria endemic countries, including Ghana. However, a major driving force sustaining malaria transmission in recent times is the asymptomatic carriage...

Free surface profiles in river flows: Can standard energy-based gradually-varied flow computations be pursued?

Science.gov (United States)

Cantero, Francisco; Castro-Orgaz, Oscar; Garcia-Marín, Amanda; Ayuso, José Luis; Dey, Subhasish

2015-10-01

Is the energy equation for gradually-varied flow the best approximation for the free surface profile computations in river flows? Determination of flood inundation in rivers and natural waterways is based on the hydraulic computation of flow profiles. This is usually done using energy-based gradually-varied flow models, like HEC-RAS, that adopts a vertical division method for discharge prediction in compound channel sections. However, this discharge prediction method is not so accurate in the context of advancements over the last three decades. This paper firstly presents a study of the impact of discharge prediction on the gradually-varied flow computations by comparing thirteen different methods for compound channels, where both energy and momentum equations are applied. The discharge, velocity distribution coefficients, specific energy, momentum and flow profiles are determined. After the study of gradually-varied flow predictions, a new theory is developed to produce higher-order energy and momentum equations for rapidly-varied flow in compound channels. These generalized equations enable to describe the flow profiles with more generality than the gradually-varied flow computations. As an outcome, results of gradually-varied flow provide realistic conclusions for computations of flow in compound channels, showing that momentum-based models are in general more accurate; whereas the new theory developed for rapidly-varied flow opens a new research direction, so far not investigated in flows through compound channels.

Which naturalism for bioethics? A defense of moderate (pragmatic) naturalism.

Science.gov (United States)

Racine, Eric

2008-02-01

There is a growing interest in various forms of naturalism in bioethics, but there is a clear need for further clarification. In an effort to address this situation, I present three epistemological stances: anti-naturalism, strong naturalism, and moderate pragmatic naturalism. I argue that the dominant paradigm within philosophical ethics has been a form of anti-naturalism mainly supported by a strong 'is' and 'ought' distinction. This fundamental epistemological commitment has contributed to the estrangement of academic philosophical ethics from major social problems and explains partially why, in the early 1980s, 'medicine saved the life of ethics'. Rejection of anti-naturalism, however, is often associated with strong forms of naturalism that commit the naturalistic fallacy and threaten to reduce the normative dimensions of ethics to biological imperatives. This move is rightly dismissed as a pitfall since ethics is, in part, a struggle against the course of nature. Rejection of naturalism has drawbacks, however, such as deterring bioethicists from acknowledging the implicit naturalistic epistemological commitments of bioethics. I argue that a moderate pragmatic form of naturalism represents an epistemological position that best embraces the tension of anti-naturalism and strong naturalism: bioethics is neither disconnected from empirical knowledge nor subjugated to it. The discussion is based upon historical writings in philosophy and bioethics.

Natural Resource Management Plan

Energy Technology Data Exchange (ETDEWEB)

Green, T. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Schwager, K. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

2016-10-01

This comprehensive Natural Resource Management Plan (NRMP) for Brookhaven National Laboratory (BNL) was built on the successful foundation of the Wildlife Management Plan for BNL, which it replaces. This update to the 2003 plan continues to build on successes and efforts to better understand the ecosystems and natural resources found on the BNL site. The plan establishes the basis for managing the varied natural resources located on the 5,265-acre BNL site, setting goals and actions to achieve those goals. The planning of this document is based on the knowledge and expertise gained over the past 15 years by the Natural Resources management staff at BNL in concert with local natural resource agencies including the New York State Department of Environmental Conservation, Long Island Pine Barrens Joint Planning and Policy Commission, The Nature Conservancy, and others. The development of this plan works toward sound ecological management that not only benefits BNL’s ecosystems but also benefits the greater Pine Barrens habitats in which BNL is situated. This plan applies equally to the Upton Ecological and Research Reserve (Upton Reserve). Any difference in management between the larger BNL area and the Upton Reserve are noted in the text.

Superheated emulsions in neutron spectrometry by varying ambient pressure

International Nuclear Information System (INIS)

Das, Mala; Sawamura, Teruko

2005-01-01

The principle of present work lies on the dependence of the threshold neutron energy on the dimensionless quantity ''degree of metastability (ss)'' of superheated liquids. The response of the superheated emulsions consists of the drops of superheated liquid (C 2 Cl 2 F 4 , b.p. 3.77 deg. C) has been measured at different 'ss' by varying ambient pressure at different temperatures, in the presence of neutrons generated in Pb by a (γ,n) reaction from 45 MeV electron LINAC of Hokkaido University. To unfold the neutron energy spectrum, a relationship has been developed between the 'ss' of superheated liquids and the threshold neutron energy. The spectrum at the detector position has been calculated by the MCNP code and a comparison has been made with the experimental spectrum. The utilisation of 'ss' is more flexible as this relation can be applied to both positive and negative ambient pressures as well as at different ambient temperatures

Synthesis, structural, morphological, optical and magnetic characterization of iron oxide (α-Fe2O3) nanoparticles by precipitation method: Effect of varying the nature of precursor

Science.gov (United States)

Lassoued, Abdelmajid; Lassoued, Mohamed Saber; Dkhil, Brahim; Ammar, Salah; Gadri, Abdellatif

2018-03-01

α-Fe2O3 nanoparticles were prepared via a precipitation method using each of three different precursors ((FeCl3, 6H2O), (Fe (C5H7O2)3) and (Fe (NO3)3, 9H2O)). The impact of varying the nature of the precursor on crystalline phase, size and magnetic parameters of α-Fe2O3 was examined. Powder X-ray diffraction pattern disclosed rhombohedral structure. The TEM and SEM results showed that the size of α-Fe2O3 nanocrystals was between 21 and 38 nm. FT-IR confirms the phase purity of prepared compounds. Raman studies showed the phonon modes. The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. The optical investigation exhibited that samples have an optical gap of 2.1 eV. The products exhibited the attractive magnetic properties with high saturation magnetization, which were examined by a vibrating sample magnetometer (VSM).

Predicting moisture state of timber members in a continuously varying climate

DEFF Research Database (Denmark)

Svensson, Staffan; Turk, Goran; Hozjan, Tomaz

2011-01-01

A prerequisite for a sensible estimate of moisture induced stresses in timber members is an accurate prediction of the members’ moisture states during their service life. There are, however, an infinite number of possible moisture states for an arbitrary timber member in a natural varying climate...... the realizations were made, are based on a fully coupled transport model including a model for the influential sorption hysteresis of wood. A format containing required information suitable for assessing the “moisture” action on timber members is proposed. In addition it is illustrated how a model of high...

Spatially varying cross-correlation coefficients in the presence of nugget effects

KAUST Repository

Kleiber, William; Genton, Marc G.

2012-01-01

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction matrix, which can be either diagonal, implying a parsimonious formulation, or a fully general contraction matrix, yielding greater flexibility but added model complexity. We illustrate the approach with a bivariate minimum and maximum temperature dataset in Colorado, allowing the two variables to be positively correlated at low elevations and nearly independent at high elevations, while still yielding a positive definite covariance matrix. © 2012 Biometrika Trust.

Spatially varying cross-correlation coefficients in the presence of nugget effects

KAUST Repository

Kleiber, William

2012-11-29

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction matrix, which can be either diagonal, implying a parsimonious formulation, or a fully general contraction matrix, yielding greater flexibility but added model complexity. We illustrate the approach with a bivariate minimum and maximum temperature dataset in Colorado, allowing the two variables to be positively correlated at low elevations and nearly independent at high elevations, while still yielding a positive definite covariance matrix. © 2012 Biometrika Trust.

Positivity Effect Specific to Older Adults with Subclinical Memory Impairment

Science.gov (United States)

Leal, Stephanie L.; Noche, Jessica A.; Murray, Elizabeth A.; Yassa, Michael A.

2016-01-01

Numerous studies have suggested that older adults preferentially remember positive information ("positivity effect"), however others have reported mixed results. One potential source of conflict is that aging is not a unitary phenomenon and individual differences exist. We modified a standard neuropsychological test to vary emotional…

Tuning Thermoresponsive Properties of Cationic Elastin-like Polypeptides by Varying Counterions and Side-Chains.

Science.gov (United States)

Petitdemange, Rosine; Garanger, Elisabeth; Bataille, Laure; Bathany, Katell; Garbay, Bertrand; Deming, Timothy J; Lecommandoux, Sébastien

2017-05-17

We report the synthesis of methionine-containing recombinant elastin-like polypeptides (ELPs) of different lengths that contain periodically spaced methionine residues. These ELPs were chemoselectively alkylated at all methionine residues to give polycationic derivatives. Some of these samples were found to possess solubility transitions in water, where the temperature of these transitions varied with ELP concentration, nature of the methionine alkylating group, and nature of the sulfonium counterions. These studies show that introduction and controlled spacing of methionine sulfonium residues into ELPs can be used as a means both to tune their solubility transition temperatures in water using a variety of different parameters and to introduce new side-chain functionality.

Microsatellites in varied arenas of research

Directory of Open Access Journals (Sweden)

K S Remya

2010-01-01

Full Text Available Microsatellites known as simple-sequence repeats (SSRs or short-tandem repeats (STRs, represent specific sequences of DNA consisting of tandemly repeated units of one to six nucleotides. The repetitive nature of microsatellites makes them particularly prone to grow or shrink in length and these changes can have both good and bad consequences for the organisms that possess them. They are responsible for various neurological diseases and hence the same cause is now utilized for the early detection of various diseases, such as, Schizophrenia and Bipolar Disorder, Congenital generalized Hypertrichosis, Asthma, and Bronchial Hyperresponsiveness. These agents are widely used for forensic identification and relatedness testing, and are predominant genetic markers in this area of application. The application of microsatellites is an extending web and covers the varied scenarios of science, such as, conservation biology, plant genetics, and population studies. At present, researches are progressing round the globe to extend the use of these genetic repeaters to unmask the hidden genetic secrets behind the creation of the world.

Error Analysis of Determining Airplane Location by Global Positioning System

OpenAIRE

Hajiyev, Chingiz; Burat, Alper

1999-01-01

This paper studies the error analysis of determining airplane location by global positioning system (GPS) using statistical testing method. The Newton Rhapson method positions the airplane at the intersection point of four spheres. Absolute errors, relative errors and standard deviation have been calculated The results show that the positioning error of the airplane varies with the coordinates of GPS satellite and the airplane.

How and Why Do Number-Space Associations Co-Vary in Implicit and Explicit Magnitude Processing Tasks?

Directory of Open Access Journals (Sweden)

Carrie Georges

2017-12-01

Full Text Available Evidence for number-space associations in implicit and explicit magnitude processing tasks comes from the parity and magnitude SNARC effect respectively. Different spatial accounts were suggested to underlie these spatial-numerical associations (SNAs with some inconsistencies in the literature. To determine whether the parity and magnitude SNAs arise from a single predominant account or task-dependent coding mechanisms, we adopted an individual differences approach to study their correlation and the extent of their association with arithmetic performance, spatial visualization ability and visualization profile. Additionally, we performed moderation analyses to determine whether the relation between these SNAs depended on individual differences in those cognitive factors. The parity and magnitude SNAs did not correlate and were differentially predicted by arithmetic performance and visualization profile respectively. These variables, however, also moderated the relation between the SNAs. While positive correlations were observed in object-visualizers with lower arithmetic performances, correlations were negative in spatial-visualizers with higher arithmetic performances. This suggests the predominance of a single account for both implicit and explicit SNAs in the two types of visualizers. However, the spatial nature of the account differs between object- and spatial-visualizers. No relation occurred in mixed-visualizers, indicating the activation of task-dependent coding mechanisms. Individual differences in arithmetic performance and visualization profile thus determined whether SNAs in implicit and explicit tasks co-varied and supposedly relied on similar or unrelated spatial coding mechanisms. This explains some inconsistencies in the literature regarding SNAs and highlights the usefulness of moderation analyses for understanding how the relation between different numerical concepts varies between individuals.

Position Statement on Active Outdoor Play

Science.gov (United States)

Tremblay, Mark S.; Gray, Casey; Babcock, Shawna; Barnes, Joel; Costas Bradstreet, Christa; Carr, Dawn; Chabot, Guylaine; Choquette, Louise; Chorney, David; Collyer, Cam; Herrington, Susan; Janson, Katherine; Janssen, Ian; Larouche, Richard; Pickett, William; Power, Marlene; Sandseter, Ellen Beate Hansen; Simon, Brenda; Brussoni, Mariana

2015-01-01

A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3–12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky) outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N = 9) and cross-sectorial individuals/organizations (N = 17), and an extensive stakeholder consultation process (N = 1908). More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: “Access to active play in nature and outdoors—with its risks— is essential for healthy child development. We recommend increasing children’s opportunities for self-directed play outdoors in all settings—at home, at school, in child care, the community and nature.” The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development. PMID:26062040

Position Statement on Active Outdoor Play.

Science.gov (United States)

Tremblay, Mark S; Gray, Casey; Babcock, Shawna; Barnes, Joel; Bradstreet, Christa Costas; Carr, Dawn; Chabot, Guylaine; Choquette, Louise; Chorney, David; Collyer, Cam; Herrington, Susan; Janson, Katherine; Janssen, Ian; Larouche, Richard; Pickett, William; Power, Marlene; Sandseter, Ellen Beate Hansen; Simon, Brenda; Brussoni, Mariana

2015-06-08

A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3-12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky) outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N=9) and cross-sectorial individuals/organizations (N=17), and an extensive stakeholder consultation process (N=1908). More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: "Access to active play in nature and outdoors--with its risks--is essential for healthy child development. We recommend increasing children's opportunities for self-directed play outdoors in all settings--at home, at school, in child care, the community and nature." The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development.

Position Statement on Active Outdoor Play

Directory of Open Access Journals (Sweden)

Mark S. Tremblay

2015-06-01

Full Text Available A diverse, cross-sectorial group of partners, stakeholders and researchers, collaborated to develop an evidence-informed Position Statement on active outdoor play for children aged 3–12 years. The Position Statement was created in response to practitioner, academic, legal, insurance and public debate, dialogue and disagreement on the relative benefits and harms of active (including risky outdoor play. The Position Statement development process was informed by two systematic reviews, a critical appraisal of the current literature and existing position statements, engagement of research experts (N = 9 and cross-sectorial individuals/organizations (N = 17, and an extensive stakeholder consultation process (N = 1908. More than 95% of the stakeholders consulted strongly agreed or somewhat agreed with the Position Statement; 14/17 participating individuals/organizations endorsed it; and over 1000 additional individuals and organizations requested their name be listed as a supporter. The final Position Statement on Active Outdoor Play states: “Access to active play in nature and outdoors—with its risks— is essential for healthy child development. We recommend increasing children’s opportunities for self-directed play outdoors in all settings—at home, at school, in child care, the community and nature.” The full Position Statement provides context for the statement, evidence supporting it, and a series of recommendations to increase active outdoor play opportunities to promote healthy child development.

Holographic cinematography of time-varying reflecting and time-varying phase objects using a Nd:YAG laser

Science.gov (United States)

Decker, A. J.

1982-01-01

The use of a Nd:YAG laser to record holographic motion pictures of time-varying reflecting objects and time-varying phase objects is discussed. Sample frames from both types of holographic motion pictures are presented. The holographic system discussed is intended for three-dimensional flow visualization of the time-varying flows that occur in jet-engine components.

A varying-coefficient method for analyzing longitudinal clinical trials data with nonignorable dropout

Science.gov (United States)

Forster, Jeri E.; MaWhinney, Samantha; Ball, Erika L.; Fairclough, Diane

2011-01-01

Dropout is common in longitudinal clinical trials and when the probability of dropout depends on unobserved outcomes even after conditioning on available data, it is considered missing not at random and therefore nonignorable. To address this problem, mixture models can be used to account for the relationship between a longitudinal outcome and dropout. We propose a Natural Spline Varying-coefficient mixture model (NSV), which is a straightforward extension of the parametric Conditional Linear Model (CLM). We assume that the outcome follows a varying-coefficient model conditional on a continuous dropout distribution. Natural cubic B-splines are used to allow the regression coefficients to semiparametrically depend on dropout and inference is therefore more robust. Additionally, this method is computationally stable and relatively simple to implement. We conduct simulation studies to evaluate performance and compare methodologies in settings where the longitudinal trajectories are linear and dropout time is observed for all individuals. Performance is assessed under conditions where model assumptions are both met and violated. In addition, we compare the NSV to the CLM and a standard random-effects model using an HIV/AIDS clinical trial with probable nonignorable dropout. The simulation studies suggest that the NSV is an improvement over the CLM when dropout has a nonlinear dependence on the outcome. PMID:22101223

Lesson "Balance in Nature

Science.gov (United States)

Chapanova, V.

2012-04-01

Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

Time-varying BRDFs.

Science.gov (United States)

Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter N; Nayar, Shree K

2007-01-01

The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.

Stability Control of Force-Reflected Nonlinear Multilateral Teleoperation System under Time-Varying Delays

Directory of Open Access Journals (Sweden)

Da Sun

2016-01-01

Full Text Available A novel control algorithm based on the modified wave-variable controllers is proposed to achieve accurate position synchronization and reasonable force tracking of the nonlinear single-master-multiple-slave teleoperation system and simultaneously guarantee overall system’s stability in the presence of large time-varying delays. The system stability in different scenarios of human and environment situations has been analyzed. The proposed method is validated through experimental work based on the 3-DOF trilateral teleoperation system consisting of three different manipulators. The experimental results clearly demonstrate the feasibility of the proposed algorithm to achieve high transparency and robust stability in nonlinear single-master-multiple-slave teleoperation system in the presence of time-varying delays.

Asymmetric vibrations of shells of revolution having meridionally varying curvature and thickness

International Nuclear Information System (INIS)

Suzuki, Katsuyoshi; Kosawada, Tadashi; Miura, Kazuyuki.

1988-01-01

An exact method using power series expansions is presented for solving asymmetric free vibration problems for shells of revolution having meridionally varying curvature and thickness. The gaverning equations of motion and the boundary conditions are derived from the stationary conditions of the Lagrangian of the shells of revolution. The method is demonstrated for shells of revolution having elliptical, cycloidal, parabolical, catenary and hyperbolical meridional curvature. The natural frequencies are numerically calculated for these shells having second degree thickness variation. (author)

Boundary conditions for natural supply ventilation

NARCIS (Netherlands)

Jansen, D.W.L.; Loomans, M.G.L.C.; Wit, de M.H.; Zeiler, W.; Seppänen, O.; Säteri, J.

2007-01-01

The development of an air jet from a controlled natural ventilation grill for different outdoor conditions is studied. Extensive laboratory measurements are taken in different situations, while the air flow rate through the grill is kept constant. The grill setting and supply temperature are varied.

Varying negative work assistance at the ankle with a soft exosuit during loaded walking.

Science.gov (United States)

Malcolm, Philippe; Lee, Sangjun; Crea, Simona; Siviy, Christopher; Saucedo, Fabricio; Galiana, Ignacio; Panizzolo, Fausto A; Holt, Kenneth G; Walsh, Conor J

2017-06-26

Only very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some studies obtained this result by means of high positive work assistance while others combined negative and positive work assistance. There is no consensus about the isolated contribution of negative work assistance. Therefore, the aim of the present study is to examine the effect of varying negative work assistance at the ankle joint while maintaining a fixed level of positive work assistance with a multi-articular soft exosuit. We tested eight participants during walking at 1.5 ms -1 with a 23-kg backpack. Participants wore a version of the exosuit that assisted plantarflexion via Bowden cables tethered to an off-board actuation platform. In four active conditions we provided different rates of exosuit bilateral ankle negative work assistance ranging from 0.015 to 0.037 W kg -1 and a fixed rate of positive work assistance of 0.19 W kg -1 . All active conditions significantly reduced metabolic rate by 11 to 15% compared to a reference condition, where the participants wore the exosuit but no assistance was provided. We found no significant effect of negative work assistance. However, there was a trend (p = .08) toward greater reduction in metabolic rate with increasing negative work assistance, which could be explained by observed reductions in biological ankle and hip joint power and moment. The non-significant trend of increasing negative work assistance with increasing reductions in metabolic rate motivates the value in further studies on the relative effects of negative and positive work assistance. There may be benefit in varying negative work over a greater range or in isolation from positive work assistance.

Gait Changes Vary Among Horses with Naturally Occurring Osteoarthritis Following Intra-articular Administration of Autologous Platelet Rich Plasma

Directory of Open Access Journals (Sweden)

Mustajab Hussain Mirza

2016-04-01

Full Text Available Mechanisms to reduce lameness associated with osteoarthritis (OA are vital to equine health and performance. This study was designed to quantify response to autologous, intra-articular platelet-rich plasma (PRP in horses with OA. Kinetic gait analysis was performed on 12 horses with unilateral forelimb lameness and OA in the same limb before and after intra-articular anesthesia (IAA. Radiographs and kinetic data were obtained before, 6 and 16 weeks after PRP administration to same joint 4 weeks after IAA. Statistical evaluations included filtration effect on platelet concentration, relationship between kinetic variable changes after IAA versus PRP in the affected limb, and associations between response to PRP and response to IAA, platelet concentration and radiographic OA. A positive response to IAA or PRP was defined as ≥5% improvement in peak vertical force, vertical impulse or breaking impulse of the affected limb. Out of 10 horses that responded to IAA, 4 responded to PRP at both time points and 2 responded at one. Of 2 horses that did not respond to IAA, one responded to PRP at both time points. Filtration increased platelet concentration significantly. The relationship between kinetic variable alterations of the affected limb after IAA and PRP was not significant, and response to PRP was not associated with response to IAA, platelet concentration or radiographic OA. Changes in kinetic variables following IAA in joints with naturally occurring OA provide a custom standard to assess intra-articular therapy. Kinetic gait changes after intra-articular PRP are variable in horses with moderate to severe forelimb OA.

An endometrial histomorphometric study of CD56 + natural killer ...

African Journals Online (AJOL)

Background. The number of peripheral blood and endometrial natural killer cells varies greatly during implantation and the first trimester of pregnancy and is thought to play a role in the maintenance of a healthy pregnancy. However, the role of endometrial CD56+ natural killer (NK) cells as an immunological mechanism in ...

Narratives of natural recovery: youth experience of social inclusion through green care.

Science.gov (United States)

Kogstad, Ragnfrid Eline; Agdal, Rita; Hopfenbeck, Mark Steven

2014-06-06

The aim of this study has been to investigate the effects of Green Care services for youth in vulnerable situations risking social exclusion. Green Care enterprises represent alternative arenas in which people can work with animals, agriculture and other tasks related to nature. We interviewed nine persons, aged 17-27, working in three different places, two or more times over a two-year period. We looked at essential beneficial factors in order to better understand how the "green" element could add to more traditional recovery factors. We found that the youth described core success factors corresponding to well-known recovery factors such as recognition, supportive relationships, motivation, meaning, positive coping, self-esteem, confidence and hope. The effective factors can be described as: (a) The leader's ability to create a good group atmosphere, (b) the varied tasks which allow step-wise increases in self-efficacy, and (c) experiences with animals and in nature that provide comfort for youth who lack trust in people and need safe situations to recover a positive sense of self. We followed a process in which several persons gradually regained self-respect and the motivation for further education or a job outside the Green Care enterprise. The study illustrates that Green Care can be an important supplement in helping people back to a satisfying life and meaningful roles in society.

Narratives of Natural Recovery: Youth Experience of Social Inclusion through Green Care

Directory of Open Access Journals (Sweden)

Ragnfrid Eline Kogstad

2014-06-01

Full Text Available The aim of this study has been to investigate the effects of Green Care services for youth in vulnerable situations risking social exclusion. Green Care enterprises represent alternative arenas in which people can work with animals, agriculture and other tasks related to nature. We interviewed nine persons, aged 17–27, working in three different places, two or more times over a two-year period. We looked at essential beneficial factors in order to better understand how the “green” element could add to more traditional recovery factors. We found that the youth described core success factors corresponding to well-known recovery factors such as recognition, supportive relationships, motivation, meaning, positive coping, self-esteem, confidence and hope. The effective factors can be described as: (a The leader’s ability to create a good group atmosphere, (b the varied tasks which allow step-wise increases in self-efficacy, and (c experiences with animals and in nature that provide comfort for youth who lack trust in people and need safe situations to recover a positive sense of self. We followed a process in which several persons gradually regained self-respect and the motivation for further education or a job outside the Green Care enterprise. The study illustrates that Green Care can be an important supplement in helping people back to a satisfying life and meaningful roles in society.

Measurement of gamma natural background radiation at Chamaraja Nagar, Karnataka state, India

International Nuclear Information System (INIS)

Nagaraju, K.M.; Chandrashekara, M.S.; Paramesh, L.

2012-01-01

The radioactive elements and their radiation are ubiquitous in the environment. The Influence of radiation on living organisms is imminent and very important to study. The ocean, the mountains, the air, and our food all expose us to small amounts of natural background radiation. Cosmic rays from outer space are another large contributor of natural background radiation. Much of the earth's natural background radiation is in the form of gamma radiation, a part of which comes from outer space. Some part of cosmic ray is filtered out by the presence of earth's atmosphere, so there are natural controls for the amount of radiation that people receive. The amount of radiation received by an individual depends on altitude, latitude type of building and the building construction materials. In the present study, measurements of natural background radiation were made in the temples, schools, dwellings, and hill stations in Chamaraja Nagar area, Karnataka state, India by using environmental dosimeter technique. The results show that, absorbed dose rate of background radiations at inside schools varies from 93.96 to 120.93 nGyh -1 with a standard deviation of 10.62 nGyh -1 and outside schools it varies from 60.9 to 113.1 nGyh -1 with a standard deviation of 15.1 nGyh -1 . In temples, the absorbed dose rate varies from 104.4 to 244.91 nGyh - 1 with a standard deviation of 48.34 nGyh -1 and outside the temples it varies from 87.9 to 176.61 nGyh -1 with a standard deviation of 30.896 nGyh -1 . The absorbed dose rate of background radiations at dwellings in indoor varies from 94.0 to 139.2 nGyh -1 with a standard deviation of 16.6 nGyh -1 and in outdoor it varies from 60.9 to 118.32 nGyh -1 with a standard deviation of 19.41 nGyh -1 . The measurements were also carried out in dwellings on hill stations in Chamaraja Nagar district. Indoor gamma dose rate varies from 103.53 to 236.64 nGyh -1 with a standard deviation of 59.8 nGyh -1 and outdoor gamma dose rate varies from 78.3 to 119

Alternative pre-rigor foreshank positioning can improve beef shoulder muscle tenderness.

Science.gov (United States)

Grayson, A L; Lawrence, T E

2013-09-01

Thirty beef carcasses were harvested and the foreshank of each side was independently positioned (cranial, natural, parallel, or caudal) 1h post-mortem to determine the effect of foreshank angle at rigor mortis on the sarcomere length and tenderness of six beef shoulder muscles. The infraspinatus (IS), pectoralis profundus (PP), serratus ventralis (SV), supraspinatus (SS), teres major (TM) and triceps brachii (TB) were excised 48 h post-mortem for Warner-Bratzler shear force (WBSF) and sarcomere length evaluations. All muscles except the SS had altered (P<0.05) sarcomere lengths between positions; the cranial position resulted in the longest sarcomeres for the SV and TB muscles whilst the natural position had longer sarcomeres for the PP and TM muscles. The SV from the cranial position had lower (P<0.05) shear than the caudal position and TB from the natural position had lower (P<0.05) shear than the parallel or caudal positions. Sarcomere length was moderately correlated (r=-0.63; P<0.01) to shear force. Copyright © 2013 Elsevier Ltd. All rights reserved.

On the relationship between positive and negative affect: Their correlation and their co-occurrence.

Science.gov (United States)

Larsen, Jeff T; Hershfield, Hal E; Stastny, Bradley J; Hester, Neil

2017-03-01

Understanding the nature of emotional experience requires understanding the relationship between positive and negative affect. Two particularly important aspects of that relationship are the extent to which positive and negative affect are correlated with one another and the extent to which they co-occur. Some researchers have assumed that weak negative correlations imply greater co-occurrence (i.e., more mixed emotions) than do strong negative correlations, but others have noted that correlations may imply very little about co-occurrence. We investigated the relationship between the correlation between positive and negative affect and co-occurrence. Participants in each of 2 samples provided moment-to-moment happiness and sadness ratings as they watched an evocative film and listened to music. Results indicated (a) that 4 measures of the correlation between positive and negative affect were quite highly related to 1 another; (b) that the strength of the correlation between measures of mixed emotions varied considerably; (c) that correlational measures were generally (but not always) weakly correlated with mixed emotion measures; and (d) that bittersweet stimuli consistently led to elevations in mixed emotion measures but did not consistently weaken the correlation between positive and negative affect. Results highlight that the correlation between positive and negative affect and their co-occurrence are distinct aspects of the relationship between positive and negative affect. Such insight helps clarify the implications of existing work on age-related and cultural differences in emotional experience and sets the stage for greater understanding of the experience of mixed emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Varying the agglomeration position of particles in a micro-channel using Acoustic Radiation Force beyond the resonance condition.

Science.gov (United States)

Dron, Olivier; Aider, Jean-Luc

2013-09-01

It is well-known that particles can be focused at mid-height of a micro-channel using Acoustic Radiation Force (ARF) tuned at the resonance frequency (h=λ/2). The resonance condition is a strong limitation to the use of acoustophoresis (particles manipulation using acoustic force) in many applications. In this study we show that it is possible to focus the particles anywhere along the height of a micro-channel just by varying the acoustic frequency, in contradiction with the resonance condition. This result has been thoroughly checked experimentally. The different physical properties as well as wall materials have been changed. The wall materials is finally the only critical parameters. One of the specificity of the micro-channel is the thickness of the carrier and reflector layer. A preliminary analysis of the experimental results suggests that the acoustic focusing beyond the classic resonance condition can be explained in the framework of the multilayered resonator proposed by Hill [1]. Nevertheless, further numerical studies are needed in order to confirm and fully understand how the acoustic pressure node can be moved over the entire height of the micro channel by varying the acoustic frequency. Despite some uncertainties about the origin of the phenomenon, it is robust and can be used for improved acoustic sorting or manipulation of particles or biological cells in confined set-ups. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental Evidence on the Nature of the Danish Employment Miracle

DEFF Research Database (Denmark)

Rosholm, Michael

-6. The treatment consisted of a dramatic intensification of labour market policies. The results show that the intensification of labour market policies is highly effective, leading to increases in the exit rate from unemployment ranging from 20 to 40%. When introducing time-varying indicators for the various......This paper uses a social experiment in labour market policy - providing early and intensive monitoring and programme participation in unemployment spells - to assess the nature of labour market policy effectiveness. The experiment was conducted in two counties in Denmark during the winter of 2005...... specific treatments actually prescribed to the unemployed workers, none of those treatments have a positive effect on the exit rate from unemployment, neither during the week in which the activity takes place, nor after the activity is completed. However, when the estimated risk of participating...

Effects of curved midline and varying width on the description of the effective diffusivity of Brownian particles

Science.gov (United States)

Chávez, Yoshua; Chacón-Acosta, Guillermo; Dagdug, Leonardo

2018-05-01

Axial diffusion in channels and tubes of smoothly-varying geometry can be approximately described as one-dimensional diffusion in the entropy potential with a position-dependent effective diffusion coefficient, by means of the modified Fick–Jacobs equation. In this work, we derive analytical expressions for the position-dependent effective diffusivity for two-dimensional asymmetric varying-width channels, and for three-dimensional curved midline tubes, formed by straight walls. To this end, we use a recently developed theoretical framework using the Frenet–Serret moving frame as the coordinate system (2016 J. Chem. Phys. 145 074105). For narrow tubes and channels, an effective one-dimensional description reducing the diffusion equation to a Fick–Jacobs-like equation in general coordinates is used. From this last equation, one can calculate the effective diffusion coefficient applying Neumann boundary conditions.

Restorative effects of virtual nature settings.

Science.gov (United States)

Valtchanov, Deltcho; Barton, Kevin R; Ellard, Colin

2010-10-01

Previous research regarding the potential benefits of exposing individuals to surrogate nature (photographs and videos) has found that such immersion results in restorative effects such as increased positive affect, decreased negative affect, and decreased stress. In the current experiment, we examined whether immersion in a virtual computer-generated nature setting could produce restorative effects. Twenty-two participants were equally divided between two conditions, while controlling for gender. In each condition, participants performed a stress-induction task, and were then immersed in virtual reality (VR) for 10 minutes. The control condition featured a slide show in VR, and the nature experimental condition featured an active exploration of a virtual forest. Participants in the nature condition were found to exhibit increased positive affect and decreased stress after immersion in VR when compared to those in the control condition. The results suggest that immersion in virtual nature settings has similar beneficial effects as exposure to surrogate nature. These results also suggest that VR can be used as a tool to study and understand restorative effects.

The role of character positional frequency on Chinese word learning during natural reading.

Directory of Open Access Journals (Sweden)

Feifei Liang

Full Text Available Readers' eye movements were recorded to examine the role of character positional frequency on Chinese lexical acquisition during reading and its possible modulation by word spacing. In Experiment 1, three types of pseudowords were constructed based on each character's positional frequency, providing congruent, incongruent, and no positional word segmentation information. Each pseudoword was embedded into two sets of sentences, for the learning and the test phases. In the learning phase, half the participants read sentences in word-spaced format, and half in unspaced format. In the test phase, all participants read sentences in unspaced format. The results showed an inhibitory effect of character positional frequency upon the efficiency of word learning when processing incongruent pseudowords both in the learning and test phase, and also showed facilitatory effect of word spacing in the learning phase, but not at test. Most importantly, these two characteristics exerted independent influences on word segmentation. In Experiment 2, three analogous types of pseudowords were created whilst controlling for orthographic neighborhood size. The results of the two experiments were consistent, except that the effect of character positional frequency was absent in the test phase in Experiment 2. We argue that the positional frequency of a word's constituent characters may influence the character-to-word assignment in a process that likely incorporates both lexical segmentation and identification.

Natural and human impacts on ecosystem services in Guanzhong - Tianshui economic region of China.

Science.gov (United States)

Li, Jing; Zhou, Z X

2016-04-01

Due to the accelerated growth of society, the gaps between the capacity of ecosystems to provide services and human needs are steadily widening. Natural, semi-natural, or managed ecosystems had been able to provide ecosystem services to meet the needs of social development. Four agricultural ecosystem services (net primary production (NPP), carbon sequestration and oxygen production (CSOP), water interception, soil conservation and agriculture production) were quantified in Guanzhong-Tianshui economic region. Estimates of ecosystem services were obtained from the analysis of satellite imagery and the use of well-known models. Based on the ecological services in Guanzhong-Tianshui economic region, this study mainly analysed the driving mechanism of the changes from the two aspects of natural drivers and human drivers. Natural drivers (climate, soil, elevation, land cover) had incentive to the ecological services. Human activity was quantified by an integrated human activity index (HAI) based on population density, farmland ratio, and the influence of road networks and residential areas. We found relationships between ecosystem services, human activities and many natural factors, however these varied according to the service studied. Human activities were mostly negatively related to each ecosystem services, while population and residential land ware positively related to agricultural production. Land use change had made a contribution to ecosystem services. Based on the selected ecosystem services and HAI, we provided sustainable ecosystem management suggestions.

Position paper on renewable energies and nature protection in European lake regions

Energy Technology Data Exchange (ETDEWEB)

Anon.

2006-07-01

development of renewable energy sources as well as the transfer of these experiences to other countries. In view of the absolutely necessary expansion of renewable energy sources worldwide, GNF's particular concern as a nature conservancy organisation is to take into consideration conservation aspects from the very beginning. Renewable energies are not to be seen as an isolated issue but must be consistent with the call for sustainable development. Today target conflicts between climate protection and bio-diversity become more and more apparent. Both issues are of great importance for lake regions. Therefore GNF pleads for a wide and open dialogue between experts from both sides. Also economy must be become more involved, adopt a position and promote positive basic conditions for renewable energies. Especially enterprises should have a strong interest to reduce their dependency on fossil energy sources and oil producing countries. (orig.)

Analysis of temperature profile and electric field in natural rubber glove due to microwave heating: effects of waveguide position

Science.gov (United States)

Keangin, P.; Narumitbowonkul, U.; Rattanadecho, P.

2018-01-01

Natural rubber (NR) is the key raw material used in the manufacture of other products such as rubber band, tire and shoes. Recently, the NR is used in natural rubber glove ( NRG) manufacturing in the industrial and medical fields. This research aims to investigate the electromagnetic wave propagation and heat transfer in NRG due to heating with microwave energy within the microwave oven at a microwave frequency of 2.45 GHz. Three-dimensional model of NRG and microwave oven are considered in this work. The comparative effects of waveguide position on the electric field and temperature profile in NRG when subjected to microwave energy are discussed. The finite element method (FEM) is used to solve the transient Maxwell’s equation coupled with the transient heat transfer equation. The simulation results with computer programs are validated with experimental results. The placement of waveguides in three cases are left hand side of microwave oven, right hand side of microwave oven and left and right hand sides of microwave oven are investigated. The findings revealed that the placing the waveguide on the right side of the microwave oven gives the highest electric field and temperature profile. The values obtained provide an indication toward understanding the study of heat transfer in NRG during microwave heating in the industry.

A varying-α brane world cosmology

International Nuclear Information System (INIS)

Youm, Donam

2001-08-01

We study the brane world cosmology in the RS2 model where the electric charge varies with time in the manner described by the varying fine-structure constant theory of Bekenstein. We map such varying electric charge cosmology to the dual variable-speed-of-light cosmology by changing system of units. We comment on cosmological implications for such cosmological models. (author)

Exploring Relationships among Tree-Ring Growth, Climate Variability, and Seasonal Leaf Activity on Varying Timescales and Spatial Resolutions

OpenAIRE

Bhuyan, Upasana;Zang, Christian;Vicente-Serrano, Sergio;Menzel, Annette

2018-01-01

In the first section of this study, we explored the relationship between ring width index (RWI) and normalized difference vegetation index (NDVI) time series on varying timescales and spatial resolutions, hypothesizing positive associations between RWI and current and previous- year NDVI at 69 forest sites scattered in the Northern Hemisphere. We noted that the relationship between RWI and NDVI varies over space and between tree types (deciduous versus coniferous), bioclimatic zones, cumulati...

Exploring Relationships among Tree-Ring Growth, Climate Variability, and Seasonal Leaf Activity on Varying Timescales and Spatial Resolutions

OpenAIRE

Upasana Bhuyan; Christian Zang; Sergio M. Vicente-Serrano; Annette Menzel

2017-01-01

In the first section of this study, we explored the relationship between ring width index (RWI) and normalized difference vegetation index (NDVI) time series on varying timescales and spatial resolutions, hypothesizing positive associations between RWI and current and previous- year NDVI at 69 forest sites scattered in the Northern Hemisphere. We noted that the relationship between RWI and NDVI varies over space and between tree types (deciduous versus coniferous), bioclimatic zones, cumulati...

Genome-wide DNA polymorphism analyses using VariScan

Directory of Open Access Journals (Sweden)

Vilella Albert J

2006-09-01

Full Text Available Abstract Background DNA sequence polymorphisms analysis can provide valuable information on the evolutionary forces shaping nucleotide variation, and provides an insight into the functional significance of genomic regions. The recent ongoing genome projects will radically improve our capabilities to detect specific genomic regions shaped by natural selection. Current available methods and software, however, are unsatisfactory for such genome-wide analysis. Results We have developed methods for the analysis of DNA sequence polymorphisms at the genome-wide scale. These methods, which have been tested on a coalescent-simulated and actual data files from mouse and human, have been implemented in the VariScan software package version 2.0. Additionally, we have also incorporated a graphical-user interface. The main features of this software are: i exhaustive population-genetic analyses including those based on the coalescent theory; ii analysis adapted to the shallow data generated by the high-throughput genome projects; iii use of genome annotations to conduct a comprehensive analyses separately for different functional regions; iv identification of relevant genomic regions by the sliding-window and wavelet-multiresolution approaches; v visualization of the results integrated with current genome annotations in commonly available genome browsers. Conclusion VariScan is a powerful and flexible suite of software for the analysis of DNA polymorphisms. The current version implements new algorithms, methods, and capabilities, providing an important tool for an exhaustive exploratory analysis of genome-wide DNA polymorphism data.

Exploration of resilience assessments for natural hazards

Science.gov (United States)

Lo Jacomo, Anna; Han, Dawei; Champneys, Alan

2017-04-01

The occurrence of extreme events due to natural hazards is difficult to predict. Extreme events are stochastic in nature, there is a lack of long term data on their occurrence, and there are still gaps in our understanding of their physical processes. This difficulty in prediction will be exacerbated by climate change and human activities. Yet traditional risk assessments measure risk as the probability of occurrence of a hazard, multiplied by the consequences of the hazard occurring, which ignores the recovery process. In light of the increasing concerns on disaster risks and the related system recovery, resilience assessments are being used as an approach which complements and builds on traditional risk assessments and management. In mechanical terms, resilience refers to the amount of energy per unit volume that a material can absorb while maintaining its ability to return to its original shape. Resilience was first applied in the fields of psychology and ecology, and more recently has been used in areas such as social sciences, economics, and engineering. A common metaphor for understanding resilience is the stability landscape. The landscape consists of a surface of interconnected basins, where each basin represents different states of a system, which is a point on the stability landscape. The resilience of the system is its capacity and tendency to remain within a particular basin. This depends on the topology of the landscape, on the system's current position, and on its reaction to different shocks and stresses. In practical terms, resilience assessments have been conducted for various purposes in different sectors. These assessments vary in their required inputs, the methodologies applied, and the output they produce. Some measures used for resilience assessments are hazard independent. These focus on the intrinsic capabilities of a system, for example the insurance coverage of a community, or the buffer capacity of a water storage reservoir. Other

Exploring positive hospital ward soundscape interventions.

Science.gov (United States)

Mackrill, J; Jennings, P; Cain, R

2014-11-01

Sound is often considered as a negative aspect of an environment that needs mitigating, particularly in hospitals. It is worthwhile however, to consider how subjective responses to hospital sounds can be made more positive. The authors identified natural sound, steady state sound and written sound source information as having the potential to do this. Listening evaluations were conducted with 24 participants who rated their emotional (Relaxation) and cognitive (Interest and Understanding) response to a variety of hospital ward soundscape clips across these three interventions. A repeated measures ANOVA revealed that the 'Relaxation' response was significantly affected (n(2) = 0.05, p = 0.001) by the interventions with natural sound producing a 10.1% more positive response. Most interestingly, written sound source information produced a 4.7% positive change in response. The authors conclude that exploring different ways to improve the sounds of a hospital offers subjective benefits that move beyond sound level reduction. This is an area for future work to focus upon in an effort to achieve more positively experienced hospital soundscapes and environments. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Bioethics and the problem of natural teleology.

Science.gov (United States)

Soontiens, F

In this paper it is argued that a re-evaluation of a teleological philosophy of nature is necessary because, first, the acceptance of natural theology would be in more accordance with the position of (teological) (wo)man as a natural product of a natural evolutionary process and, second, it seems to be a prerequisite for the formulation of an adequate bio- und eco-ethics which stresses the "intrinsic value" of nature.

Permeation Behavior and Physical Properties of Natural Rubber Nanocomposites

National Research Council Canada - National Science Library

Zukas, Walter; Sennett, Michael; Welsh, Elizabeth; Rodriguez, Axel; Ziegler, David; Touchet, Paul

2004-01-01

.... A study was carried out to examine the effects of varying nanoparticle morphology and composition on the mechanical and barrier properties of polymer nanocomposites made with natural rubber (NR...

Monitoring of 7Be in surface air of varying PM10 concentrations

International Nuclear Information System (INIS)

Chao, J.H.; Liu, C.C.; Cho, I.C.; Niu, H.

2014-01-01

In this study, beryllium-7 ( 7 Be) concentrations of surface air were monitored throughout a span of 23 years (1992–2012) in the Taiwanese cities Yilan, Taipei, Taichung, and Kaohsiung. During this period, particulate matter (PM) concentrations, in terms of PM 10 , were collected monthly from the nearest air-quality pollutant monitoring stations and compared against 7 Be concentrations. Seasonal monsoons influenced 7 Be concentrations in all cities, resulting in high winter and low summer concentrations. In addition, the meteorological conditions caused seasonal PM 10 variations, yielding distinct patterns among the cities. There was no correlation between 7 Be and PM 10 in the case cities. The average annual 7 Be concentrations varied little among the cities, ranging from 2.9 to 3.5 mBq/m 3 , while the PM 10 concentrations varied significantly from 38 μg/m 3 in Yilan to 92 μg/m 3 in Kaohsiung depending on the degree of air pollution and meteorological conditions. The correlation between the 7 Be concentration and gross-beta activities (A β ) in air implied that the 7 Be was mainly attached to crustal PM and its concentration varied little among the cities, regardless of the increase in anthropogenic PM in air-polluted areas. - Highlights: • Both 7 Be and PM 10 concentrations were monitored in four Taiwanese cities from 1992 to 2012. • Seasonal variations of 7 Be and PM 10 were explained based on on meteorological and pollution conditions. • The annual concentrations of 7 Be varied little among the four cities even in high PM environment. • 7 Be is believed to mainly attach to natural PM in the cities that exhibited varying PM 10 concentrations

The impact of the microphone position on the frequency analysis of snoring sounds.

Science.gov (United States)

Herzog, Michael; Kühnel, Thomas; Bremert, Thomas; Herzog, Beatrice; Hosemann, Werner; Kaftan, Holger

2009-08-01

Frequency analysis of snoring sounds has been reported as a diagnostic tool to differentiate between different sources of snoring. Several studies have been published presenting diverging results of the frequency analyses of snoring sounds. Depending on the position of the used microphones, the results of the frequency analysis of snoring sounds vary. The present study investigated the influence of different microphone positions on the outcome of the frequency analysis of snoring sounds. Nocturnal snoring was recorded simultaneously at six positions (air-coupled: 30 cm middle, 100 cm middle, 30 cm lateral to both sides of the patients' head; body contact: neck and parasternal) in five patients. The used microphones had a flat frequency response and a similar frequency range (10/40 Hz-18 kHz). Frequency analysis was performed by fast Fourier transformation and frequency bands as well as peak intensities (Peaks 1-5) were detected. Air-coupled microphones presented a wider frequency range (60 Hz-10 kHz) compared to contact microphones. The contact microphone at cervical position presented a cut off at frequencies above 300 Hz, whereas the contact microphone at parasternal position revealed a cut off above 100 Hz. On an exemplary base, the study demonstrates that frequencies above 1,000 Hz do appear in complex snoring patterns, and it is emphasised that high frequencies are imported for the interpretation of snoring sounds with respect to the identification of the source of snoring. Contact microphones might be used in screening devices, but for a natural analysis of snoring sounds the use of air-coupled microphones is indispensable.

Teorias da lei natural: Pufendorf e Rousseau Natural law theories: Pufendorf and Rousseau

Directory of Open Access Journals (Sweden)

Luiz Felipe Netto de Andrade e Silva Sahd

2007-01-01

Full Text Available O presente artigo tem como objetivo reconstruir argumentos centrais desenvolvidos por Jean-Jacques Rousseau. Contra Samuel Pufendorf, Rousseau defende que a justiça não é natural. Ele recusa todo compromisso com a lei natural tradicional para voltar à posição de Thomas Hobbes. Ora, no estado originário de natureza, os princípios racionais da lei natural que expõe Pufendorf não podem ser conhecidos, e, por conseguinte, quando puderem ser conhecidos, não serão aplicados por natureza.The present article aims at reconstructing Jean-Jacques Rousseau’s central arguments. Against Samuel Pufendorf, Rousseau maintains that justice is not natural, thereby rejecting the compromise with traditional natural law and wholly returning to the position of Thomas Hobbes. Now, in the original state of nature, Pufendorf’s rational principles of natural law cannot be known; later, when they may be known, they are not by nature enforced.

Feature-aware natural texture synthesis

KAUST Repository

Wu, Fuzhang

2014-12-04

This article presents a framework for natural texture synthesis and processing. This framework is motivated by the observation that given examples captured in natural scene, texture synthesis addresses a critical problem, namely, that synthesis quality can be affected adversely if the texture elements in an example display spatially varied patterns, such as perspective distortion, the composition of different sub-textures, and variations in global color pattern as a result of complex illumination. This issue is common in natural textures and is a fundamental challenge for previously developed methods. Thus, we address it from a feature point of view and propose a feature-aware approach to synthesize natural textures. The synthesis process is guided by a feature map that represents the visual characteristics of the input texture. Moreover, we present a novel adaptive initialization algorithm that can effectively avoid the repeat and verbatim copying artifacts. Our approach improves texture synthesis in many images that cannot be handled effectively with traditional technologies.

Child-Langmuir flow with periodically varying anode voltage

International Nuclear Information System (INIS)

Rokhlenko, A.

2015-01-01

Using the Lagrangian technique, we study settled Child-Langmuir flows in a one dimensional planar diodes whose anode voltages periodically vary around given positive values. Our goal is to find analytically if the average currents in these systems can exceed the famous Child-Langmuir limit found for the stationary current a long time ago. The main result of our study is that in a periodic quasi-stationary regime the average current can be larger than the Child-Langmuir maximum even by 50% compared with its adiabatic average value. The cathode current in this case has the form of rectangular pulses which are formed by a very special triangular voltage modulation. This regime, i.e., periodicity, shape of pulses, and their amplitude, needs to be carefully chosen for the best performance

GammaSense: Infrastructureless Positioning using Background Radioactivity

DEFF Research Database (Denmark)

Bucur, Doina; Kjærgaard, Mikkel Baun

2008-01-01

-versus-outdoor locations. We find that the performance of a machine-learning algorithm in detecting position varies with the building, and is highest for interfloor detection in the case of an old domestic house, while it is highest for intrafloor detection if the floor spans building segments made from different...

Flow of wet natural pozzolana

Energy Technology Data Exchange (ETDEWEB)

Medici, M E; Benegas, O A; Aguirre, F; Baudino, M R [Departamento de Mineria, Universidad Nacional de San Luis, 5700 San Luis (Argentina); Unac, R O; Vidales, A M [INFAP-CONICET, Departamento de Fisica, Universidad Nacional de San Luis, 5700 San Luis (Argentina); Ippolito, I, E-mail: avidales@unsl.edu.a [GMP, CONICET y Facultad de Ingenieria, Universidad de Buenos Aires, 1063 Buenos Aires (Argentina)

2009-05-01

We present experimental results on the flow and stability conditions for natural pozzolana, a natural volcanic sand widely used in concrete production. We measured different angles involved in equilibrium conditions for sand piles and relate them to the flux parameters necessary to produce a silo evacuation. We vary some of the geometrical parameters in the silo to inspect the different flux responses of the system. Results are showed as a function of humidity present in the system. In this way, we related critical angles with flux conditions through a silo under different geometric setups and different humidity degrees, thus setting up a basic phase diagram for flux.

Geschichte der Natur bei Alexander von Humboldt

Directory of Open Access Journals (Sweden)

Christian Helmreich

2009-05-01

Full Text Available Article in German, Abstracts in English, German and French.This article analyses the importance of an historical view of nature in the works of Alexander von Humboldt. In several of his first writings, Humboldt seems to outline the importance of what one may call history of nature. But even before his famous American travel, his position changed and he became reluctant to accept the seriousness of historical enquiry in the area of natural sciences: if we want to reconstruct the past state of nature, we cannot rely on empirical proofs; and history of nature is therefore necessarily based on uncertain hypotheses. Humboldt kept his sceptical attitude in the first decades of the 19th century, despite the positive results of the palaeontological researches of his scientific colleagues. However, he gradually convinced himself of the scientific interest of historical investigations in the natural sciences. The Cosmos paradoxally displays two apparently conflicting points of view: in his methodological remarks, Humboldt maintains that precise accounts of the past state of nature are out of reach of human knowledge, yet elsewhere in the same Cosmos he gives broad and rather vivid descriptions of the eventful history of nature.

Variation of Natural Gamma Radiation in Isparta

International Nuclear Information System (INIS)

Akkurt, I.

2004-01-01

There is always a radiation in the earth, and its level is generated primarily by galactic cosmic rays (GCR), consisting of energetic nuclei of all naturally occurring elements, interacting with atmospheric constituents, through atomic and nuclear collisions. The other sources of natural radiations are global average background radiation from terrestrial sources such as soils, rocks ete. Background radiation levels in the atmosphere vary in intensity with latitude, altitude and phase of the solar cycle. Variation of natural radiation as a function of altitude, geological structure etc has been investigated. The measurements were performed using portable radiation counter which connected to NaI(Tl) probe

The effect of varying degrees of stenosis on the characteristics of turbulent pulsatile flow through heart valves.

Science.gov (United States)

Bluestein, D; Einav, S

1995-08-01

Many problems and complications associated with heart valves are related to the dynamic behavior of the valve and the resultant unsteady flow patterns. An accurate depiction of the spatial and temporal velocity and rms distributions imparts better understanding of flow related valve complications, and may be used as a guideline in valve design. While the generalized correlation between increased turbulence level and the severity of the stenosis is well established, few studies addressed the issue of the intermittent nature of turbulence and its timing in the cardiac cycle, and almost none assessed the effect of a progressive stenosis on the flow characteristics through heart valves. In this experimental work we simulated the type of flow which is present in normal and stenosed valves and conducted a comprehensive investigation of valve hemodynamics, valvular turbulence and morphology under varying degrees of stenosis. The characteristics of valves and stenoses were simulated closely, to achieve the flow conditions that initiate turbulent flow conditions. Laser Doppler anemometry (LDA) measurements were carried out in a pulse duplicator system distal to trileaflet polyurethane prosthetic heart valves, installed at mitral and aortic positions. The effect of the degree of the stenosis was comparatively studied through the structure of the turbulent jets emerging from normal and stenotic heart valves. Maximum turbulence level was achieved during the decelerating phase and correlated to the severity of the stenosis, followed by relaminarization of the flow during the acceleration phase. The intermittent nature of the turbulence emphasized the importance of realizing the timing of the turbulence production and its spatial location for optimizing current valve designs. The plug flow through the normal aortic valve prosthesis was replaced by jet like behavior for a 65% stenosis, with the jet becoming narrower and stronger for a 90% stenosis. The morphology of the velocity

Development of natural gas ocean transportation chain by means of natural gas hydrate (NGH)

International Nuclear Information System (INIS)

Nogami, T.; Oya, N.; Ishida, H.; Matsumoto, H.

2008-01-01

Recent studies in Japan have suggested that natural gas hydrate (NGH) transportation of natural gas is more economical than liquefied natural gas (LNG) transportation systems for small, medium and remote gas fields. Researchers in Japan have built a 600 kg per day NGH production and pelletizing plant and regasification facility. This paper discussed feasibility studies conducted in southeast Asia to determine the unit's commercialization potential with large natural gas-related businesses including shipping companies and electric power utilities. The total supply chain was compared with the corresponding liquefied natural gas (LNG) and compressed natural gas (CNG) supply chains. The study also examined natural gas reserves, energy policies, the positioning of natural gas supplies, and future forecasts of natural gas demand. A conceptual design for an NGH supply chain in Indonesia was presented. Results of the study have demonstrated that the NGH chain is an appropriate and economically feasible transportation method for many areas in southeast Asia. 8 refs., 10 figs

Endocannabinoid and Mood Responses to Exercise in Adults with Varying Activity Levels.

Science.gov (United States)

Brellenthin, Angelique G; Crombie, Kevin M; Hillard, Cecilia J; Koltyn, Kelli F

2017-08-01

Acute aerobic exercise improves mood and activates the endocannabinoid (eCB) system in physically active individuals; however, both mood and eCB responses to exercise may vary based on habitual levels of physical activity. This study aimed to examine eCB and mood responses to prescribed and preferred exercises among individuals with low, moderate, and high levels of physical activity. Thirty-six healthy adults (21 ± 4 yr) were recruited from low (≤60 min moderate-vigorous physical activity [MVPA] per week), moderate (150-299 min MVPA per week), and high (≥300 MVPA per week) physical activity groups. Participants performed both prescribed (approximately 70%-75% max) and preferred (i.e., self-selected) aerobic exercise on separate days. Mood states and eCB concentrations were assessed before and after exercise conditions. Both preferred and prescribed exercise resulted in significant increases (P exercise elicited positive mood improvements compared with preexercise values, but changes in state anxiety, total mood disturbance, and confusion were greater in the preferred condition (P mood disturbance in the preferred condition (P mood or eCB outcomes. These results indicate that eCB and mood responses to exercise do not differ significantly between samples with varying physical activity levels. This study also demonstrates that in addition to prescribed exercise, preferred exercise activates the eCB system, and this activation may contribute to positive mood outcomes with exercise.

Asymmetric vibrations of thick shells of revolution having meridionally varying curvature

International Nuclear Information System (INIS)

Suzuki, Katsuyoshi; Kosawada, Tadashi; Yachita, Takumi.

1988-01-01

An exact method using power series expansions is presented for solving asymmetric free vibration problems for thick shells of revolution having meridionally varying curvature. Based on the improved thick shell theory, the Lagrangian of the shells of revolution are obtained, and the equations of motion and the boundary conditions are derived from the stationary condition of the Lagrangian. The method is demonstrated for thick shells of revolution having elliptical, cycloidal, parabolical, catenary and hyperbolical meridional curvature. The results by the present method are compared with those by the thin shell theory and the effects of the rotatory inertia and the shear deformation upon the natural frequencies are clarified. (author)

Hydroquinone–pyrrole dyads with varied linkers

Directory of Open Access Journals (Sweden)

Hao Huang

2016-01-01

Full Text Available A series of pyrroles functionalized in the 3-position with p-dimethoxybenzene via various linkers (CH2, CH2CH2, CH=CH, C≡C has been synthesized. Their electronic properties have been deduced from 1H NMR, 13C NMR, and UV–vis spectra to detect possible interactions between the two aromatic subunits. The extent of conjugation between the subunits is largely controlled by the nature of the linker, with the largest conjugation found with the trans-ethene linker and the weakest with the aliphatic linkers. DFT calculations revealed substantial changes in the HOMO–LUMO gap that correlated with the extent of conjugation found experimentally. The results of this work are expected to open up for use of the investigated compounds as components of redox-active materials in sustainable, organic electrical energy storage devices.

Position-sensitive radiation detector

International Nuclear Information System (INIS)

Mathieson, E.; Smith, G.C.; Gilvin, P.J.

1981-01-01

Apparatus for sensing the position of radiation received has a plurality of receptors spaced in at least one line on which the position is to be determined, their outputs being associated to form at least two groups, the density of the receptors in each group varying along the line. The receptors may comprise cathode arrays of a multiwire proportional counter, with an anode array between, measuring along lines in directions x and y respectively. The density of the wires in the two groups, decreases in opposite directions. A circuit determines the ratio of the output of one group to the sum of the group outputs. In another embodiment a scintillator is viewed by a plurality of light guides, the ends of which adjacent to the scintillator form the receptors, the four groups of which each terminate on a photomultiplier. (author)

Prevalence of Allergy to Natural Rubber Latex and Potential Cross Reacting Food in Operation Room Staff in Shiraz Hospitals -2006

Directory of Open Access Journals (Sweden)

H Nabavizade

2007-07-01

Full Text Available Introduction & Objective: Allergic reactions to natural rubber latex have increased during past 10 years especially among health care workers and patients with high exposure to latex allergens. Allergic reaction to latex is related to many diseases like occupational asthma. This study was performed to determine the prevalence of allergy to natural rubber latex and potential cross reacting food in operation room staff in Shiraz hospitals. Materials & Methods: In this cross-sectional descriptive study five hundred eighty operation room staff of ten private and state hospitals in Shiraz completed latex allergy questionnaire. They were questioned about personal history and previous history of latex sensitivity, symptoms of latex reactivity and about other allergies particularly to foods that may cross react with latex. Informed consent was obtained and skin prick testing was performed with natural rubber latex. Skin prick tests were done with three potentially cross reacting food (banana, Kiwi, and potato. The obtained data were analyzed with SPSS software and Chi-square test. Results: Among the 580 operation room workers 104 (17.9 % of participants were positive to latex skin test. We found a significant association between positive skin test to latex in operation room staff and atopy, urticaria and food allergy. Positive skin test to latex related to positive kiwi skin test (p<0.05. The prevalence did not vary by sex, age, education, surgical and non surgical glove users, history of contact dermatitis or smoking status. Conclusion: Latex allergy has a high prevalence in personnel of operation room. Evaluation of present symptom and prediction of future disease necessitate screening test in individuals at risk.

Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

Energy Technology Data Exchange (ETDEWEB)

Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMcahon, Katherine D.; Mamlstrom, Rex R.

2014-05-12

Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ecotype model? of diversification, but not previously observed in natural populations.

Genome-wide Selective Sweeps in Natural Bacterial Populations Revealed by Time-series Metagenomics

Energy Technology Data Exchange (ETDEWEB)

Chan, Leong-Keat; Bendall, Matthew L.; Malfatti, Stephanie; Schwientek, Patrick; Tremblay, Julien; Schackwitz, Wendy; Martin, Joel; Pati, Amrita; Bushnell, Brian; Foster, Brian; Kang, Dongwan; Tringe, Susannah G.; Bertilsson, Stefan; Moran, Mary Ann; Shade, Ashley; Newton, Ryan J.; Stevens, Sarah; McMahon, Katherine D.; Malmstrom, Rex R.

2014-06-18

Multiple evolutionary models have been proposed to explain the formation of genetically and ecologically distinct bacterial groups. Time-series metagenomics enables direct observation of evolutionary processes in natural populations, and if applied over a sufficiently long time frame, this approach could capture events such as gene-specific or genome-wide selective sweeps. Direct observations of either process could help resolve how distinct groups form in natural microbial assemblages. Here, from a three-year metagenomic study of a freshwater lake, we explore changes in single nucleotide polymorphism (SNP) frequencies and patterns of gene gain and loss in populations of Chlorobiaceae and Methylophilaceae. SNP analyses revealed substantial genetic heterogeneity within these populations, although the degree of heterogeneity varied considerably among closely related, co-occurring Methylophilaceae populations. SNP allele frequencies, as well as the relative abundance of certain genes, changed dramatically over time in each population. Interestingly, SNP diversity was purged at nearly every genome position in one of the Chlorobiaceae populations over the course of three years, while at the same time multiple genes either swept through or were swept from this population. These patterns were consistent with a genome-wide selective sweep, a process predicted by the ‘ecotype model’ of diversification, but not previously observed in natural populations.

Rotation-invariant features for multi-oriented text detection in natural images.

Directory of Open Access Journals (Sweden)

Cong Yao

Full Text Available Texts in natural scenes carry rich semantic information, which can be used to assist a wide range of applications, such as object recognition, image/video retrieval, mapping/navigation, and human computer interaction. However, most existing systems are designed to detect and recognize horizontal (or near-horizontal texts. Due to the increasing popularity of mobile-computing devices and applications, detecting texts of varying orientations from natural images under less controlled conditions has become an important but challenging task. In this paper, we propose a new algorithm to detect texts of varying orientations. Our algorithm is based on a two-level classification scheme and two sets of features specially designed for capturing the intrinsic characteristics of texts. To better evaluate the proposed method and compare it with the competing algorithms, we generate a comprehensive dataset with various types of texts in diverse real-world scenes. We also propose a new evaluation protocol, which is more suitable for benchmarking algorithms for detecting texts in varying orientations. Experiments on benchmark datasets demonstrate that our system compares favorably with the state-of-the-art algorithms when handling horizontal texts and achieves significantly enhanced performance on variant texts in complex natural scenes.

Zhang neural network for online solution of time-varying convex quadratic program subject to time-varying linear-equality constraints

International Nuclear Information System (INIS)

Zhang Yunong; Li Zhan

2009-01-01

In this Letter, by following Zhang et al.'s method, a recurrent neural network (termed as Zhang neural network, ZNN) is developed and analyzed for solving online the time-varying convex quadratic-programming problem subject to time-varying linear-equality constraints. Different from conventional gradient-based neural networks (GNN), such a ZNN model makes full use of the time-derivative information of time-varying coefficient. The resultant ZNN model is theoretically proved to have global exponential convergence to the time-varying theoretical optimal solution of the investigated time-varying convex quadratic program. Computer-simulation results further substantiate the effectiveness, efficiency and novelty of such ZNN model and method.

Is there a positive relationship between naturalness and genetic diversity in forest tree communities?

OpenAIRE

Wehenkel, C.; Corral-Rivas, J. J.; Castellanos-Bocaz, H. A.; Pinedo-Alvarez, A.

2009-01-01

The concepts of genetic diversity and naturalness are well known as measures of conservation values and as descriptors of state or condition. A lack of research evaluating the relationship between genetic diversity and naturalness in biological communities, along with the possible implications in terms of evolutionary aspects and conservation management, make this subject particularly important as regards forest tree communities.We therefore examined the following hypothesis: the genetic dive...

Nature inspires sensors to do more with less.

Science.gov (United States)

Mulvaney, Shawn P; Sheehan, Paul E

2014-10-28

The world is filled with widely varying chemical, physical, and biological stimuli. Over millennia, organisms have refined their senses to cope with these diverse stimuli, becoming virtuosos in differentiating closely related antigens, handling extremes in concentration, resetting the spent sensing mechanisms, and processing the multiple data streams being generated. Nature successfully deals with both repeating and new stimuli, demonstrating great adaptability when confronted with the latter. Interestingly, nature accomplishes these feats using a fairly simple toolbox. The sensors community continues to draw inspiration from nature's example: just look at the antibodies used as biosensor capture agents or the neural networks that process multivariate data streams. Indeed, many successful sensors have been built by simply mimicking natural systems. However, some of the most exciting breakthroughs occur when the community moves beyond mimicking nature and learns to use nature's tools in innovative ways.

Positive streamers in air and nitrogen of varying density: experiments on similarity laws

International Nuclear Information System (INIS)

Briels, T M P; Van Veldhuizen, E M; Ebert, U

2008-01-01

Positive streamers in ambient air at pressures from 0.013 to 1 bar are investigated experimentally. The voltage applied to the anode needle ranges from 5 to 45 kV, the discharge gap from 1 to 16 cm. Using a 'slow' voltage rise time of 100-180 ns, the streamers are intentionally kept thin. For each pressure p, we find a minimal diameter d min . To test whether streamers at different pressures are similar, the minimal streamer diameter d min is multiplied by its pressure p; we find this product to be well approximated by p · d min = 0.20 ± 0.02 mm bar over two decades of air pressure at room temperature. The value also fits diameters of sprite discharges above thunderclouds at an altitude of 80 km when extrapolated to room temperature (as air density rather than pressure determines the physical behaviour). The minimal velocity of streamers in our measurements is approximately 0.1 mm ns -1 = 10 5 m s -1 . The same minimal velocity has been reported for tendrils in sprites. We also investigate the size of the initial ionization cloud at the electrode tip from which the streamers emerge, and the streamer length between branching events. The same quantities are also measured in nitrogen with a purity of approximately 99.9%. We characterize the essential differences with streamers in air and find a minimal diameter of p · d min = 0.12 ± 0.02 mm bar in our nitrogen.

Electromyography analysis of natural mastication behavior using varying mouthful quantities of two types of gels.

Science.gov (United States)

Kohyama, Kaoru; Gao, Zhihong; Ishihara, Sayaka; Funami, Takahiro; Nishinari, Katsuyoshi

2016-07-01

The objectives of this study were to examine the effects of mouthful quantities and mechanical properties of gels on natural mastication behaviors using electromyography (EMG). Two types of hydrocolloid gels (A and K) with similar fracture loads but different moduli and fracture strains were served to eleven normal women in 3-, 6-, 12-, and 24-g masses in a randomized order. EMG activities from both masseter muscles were recorded during natural mastication. Because of the similar fracture loads, the numbers of chews, total muscle activities, and entire oral processing times were similar for similar masses of both gel types. Prior to the first swallow, the more elastic K gel with a higher fracture strain required higher muscle activities than the brittle A gel, which had higher modulus. Majority of subjects had preferred sides of chewing, but all subjects with or without preferred sides used both masseters during the consumption of gels. Similar effects of masses and types of gels were observed in EMG activities of both sides of masseters. Contributions of the dominant side of chewing were diminished with increasing masses of gels, and the mass dependency on ratio of the dominant side was more pronounced with K gel. More repetitions of smaller masses required greater muscle activities and longer periods for the consumption of 24-g gel portions. Reduction in the masses with an increased number of repetitions necessitated slower eating and more mastication to consume the gel portions. These observations suggest that chewing using both sides is more effective and unconsciously reduces mastication times during the consumption of gels. Copyright © 2016 Elsevier Inc. All rights reserved.

The response of natural enemies to selective insecticides applied to soybean.

Science.gov (United States)

Varenhorst, A J; O'Neal, M E

2012-12-01

Natural enemies of the invasive pest Aphis glycines Matsumura can prevent its establishment and population growth. However, current A. glycines management practices include the application of broad-spectrum insecticides that affect pests and natural enemies that are present in the field at the time of application. An alternative is the use of selective insecticides that affect the targeted pest species, although having a reduced impact on the natural enemies. We tested the effects of esfenvalerate, spirotetramat, imidacloprid, and a combination of spirotetramat and imidacloprid on the natural enemies in soybean during the 2009 and 2010 field season. The natural enemy community that was tested differed significantly between 2009 and 2010 (F = 87.41; df = 1, 598; P natural enemy in 2009 was Harmonia axyridis (Pallas) (56.0%) and in 2010 was Orius insidiosus (Say) (41.0%). During 2009, the abundance of natural enemies did not vary between the broad-spectrum and selective insecticides; however, the abundance of natural enemies was reduced by all insecticide treatments when compared with the untreated control. In 2010, the selective insecticide imidacloprid had more natural enemies than the broad-spectrum insecticide. Although we did not observe a difference in the abundance of the total natural enemy community in 2009, we did observe more H. axyridis in plots treated with spirotetramat. In 2010, we observed more O. insidiosus in plots treated with imidacloprid. We suggest a couple of mechanisms to explain how the varying insecticides have different impacts on separate components of the natural enemy community.

Business cycles and natural gas prices

International Nuclear Information System (INIS)

Apostolos, S.; Asghar, S.

2005-01-01

This paper investigates the basic stylised facts of natural gas price movements using data for the period that natural gas has been traded on an organised exchange and the methodology suggested by Kydland and Prescott (1990). Our results indicate that natural gas prices are procyclical and lag the cycle of industrial production. Moreover, natural gas prices are positively contemporaneously correlated with United States consumer prices and lead the cycle of consumer prices, raising the possibility that natural gas prices might be a useful guide for US monetary policy, like crude oil prices are, possibly serving as an important indicator variable. (author)

Turbulence characteristics of flow in an open channel with temporally varying mobile bedforms

Directory of Open Access Journals (Sweden)

Hanmaiahgari Prashanth Reddy

2017-03-01

Full Text Available Turbulence of flow over mobile bedforms in natural open channels is not yet clearly understood. An attempt is made in this paper to determine the effect of naturally formed mobile bedforms on velocities, turbulent intensities and turbulent stresses. Instantaneous velocities are measured using a two-dimensional particle image velocimetry (PIV to evaluate the turbulence structure of free surface flow over a fixed (immobile bed, a weakly mobile bed and a temporally varying mobile bed with different stages of bedform development. This paper documents the vertical distribution of velocity, turbulence intensities, Reynolds shear stress and higher-order moments including skewness and turbulent diffusion factors. Analysis of the velocity distributions shows a substantial decrease of velocity near the bed with increasing bedform mobility due to increased friction. A modified logarithmic law with a reduced von Kármán constant and increased velocity shift is proposed for the case of the mobile bedforms. A significant increase in the Reynolds shear stress is observed in the mobile bedforms experiments accompanied by changes over the entire flow depth compared to an immobile bed. The skewness factor distribution was found to be different in the case of the flow over the mobile bedforms. All higher-order turbulence descriptors are found to be significantly affected by the formation of temporally varying and non-equilibrium mobile bedforms. Quadrant analysis indicates that sweep and outward events are found to be dominant in strongly mobile bedforms and govern the bedform mobility.

Spacetime-varying couplings and Lorentz violation

International Nuclear Information System (INIS)

Kostelecky, V. Alan; Lehnert, Ralf; Perry, Malcolm J.

2003-01-01

Spacetime-varying coupling constants can be associated with violations of local Lorentz invariance and CPT symmetry. An analytical supergravity cosmology with a time-varying fine-structure constant provides an explicit example. Estimates are made for some experimental constraints

Propagation of 3D internal gravity wave beams in a slowly varying stratification

Science.gov (United States)

Fan, Boyu; Akylas, T. R.

2017-11-01

The time-mean flows induced by internal gravity wave beams (IGWB) with 3D variations have been shown to have dramatic implications for long-term IGWB dynamics. While uniform stratifications are convenient both theoretically and in the laboratory, stratifications in the ocean can vary by more than an order of magnitude over the ocean depth. Here, in view of this fact, we study the propagation of a 3D IGWB in a slowly varying stratification. We assume that the stratification varies slowly relative to the local variations in the wave profile. In the 2D case, the IGWB bends in response to the changing stratification, but nonlinear effects are minor even in the finite amplitude regime. For a 3D IGWB, in addition to bending, we find that nonlinearity results in the transfer of energy from waves to a large-scale time-mean flow associated with the mean potential vorticity, similar to IGWB behavior in a uniform stratification. In a weakly nonlinear setting, we derive coupled evolution equations that govern this process. We also use these equations to determine the stability properties of 2D IGWB to 3D perturbations. These findings indicate that 3D effects may be relevant and possibly fundamental to IGWB dynamics in nature. Supported by NSF Grant DMS-1512925.

Integrating Content and Language in Institutionally Monolingual Settings: Teacher Positioning and Differentiation

Science.gov (United States)

Turner, Marianne

2017-01-01

Translanguaging pedagogy offers a way to differentiate between students' varying linguistic repertoires when embedding an additional language across the curriculum. In this article I draw on positioning theory to show the relevance of teacher positioning to translanguaging pedagogy and differentiation. Differentiation is discussed in relation to…

Spall Strength Measurements of Concrete for Varying Aggregate Sizes

International Nuclear Information System (INIS)

Chhabildas, Lalit C.; Kipp, Marlin E.; Reinhart, William D.; Wilson, Leonard T.

1999-01-01

Controlled impact experiments have been performed to determine the spall strength of four different concrete compositions. The four concrete compositions are identified as, 'SAC-5, CSPC', (''3/4'') large, and (''3/8'') small, Aggregate. They differ primarily in aggregate size but with average densities varying by less than five percent. Wave profiles from sixteen experiments, with shock amplitudes of 0.07 to 0.55 GPa, concentrate primarily within the elastic regime. Free-surface particle velocity measurements indicate consistent pullback signals in the release profiles, denoting average span strength of approximately 40 MPa. It is the purpose of this paper to present spall measurements under uniaxial strain loading. Notwithstanding considerable wave structure that is a unique characteristic to the heterogeneous nature of the scaled concrete, the spall amplitudes appear reproducible and consistent over the pressure range reported in this study

Investigation of natural radioactivity level of the waters in Inner Mongolia

International Nuclear Information System (INIS)

Du Xuelin; Li Wenyuan; Fu Su

1993-01-01

The authors reports the investigation results of natural radioactivity level in rivers, lakes, reservoirs, springs, wells and tap water in Inner Mongolia Autonomous Region. There were totally 326 samples collected from 178 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

The relationship between nature connectedness and happiness: a meta-analysis

Directory of Open Access Journals (Sweden)

Colin A. Capaldi

2014-09-01

Full Text Available Research suggests that contact with nature can be beneficial, for example leading to improvements in mood, cognition, and health. A distinct but related idea is the personality construct of subjective nature connectedness, a stable individual difference in cognitive, affective, and experiential connection with the natural environment. Subjective nature connectedness is a strong predictor of pro-environmental attitudes and behaviours that may also be positively associated with subjective well-being. This meta-analysis was conducted to examine the relationship between nature connectedness and happiness. Based on 30 samples (n = 8,523, a fixed-effect meta-analysis found a small but significant effect size (r = .19. Those who are more connected to nature tended to experience more positive affect, vitality, and life satisfaction compared to those less connected to nature. Publication status, year, average age, and percentage of females in the sample were not significant moderators. Vitality had the strongest relationship with nature connectedness (r = .24, followed by positive affect (r = .22 and life satisfaction (r = .17. In terms of specific nature connectedness measures, associations were the strongest between happiness and inclusion of nature in self (r = .27, compared to nature relatedness (r = .18 and connectedness to nature (r = .18. This research highlights the importance of considering personality when examining the psychological benefits of nature. The results suggest that closer human-nature relationships do not have to come at the expense of happiness. Rather, this meta-analysis shows that being connected to nature and feeling happy are, in fact, connected.

Sustained attention to objects' motion sharpens position representations: Attention to changing position and attention to motion are distinct.

Science.gov (United States)

Howard, Christina J; Rollings, Victoria; Hardie, Amy

2017-06-01

In tasks where people monitor moving objects, such the multiple object tracking task (MOT), observers attempt to keep track of targets as they move amongst distracters. The literature is mixed as to whether observers make use of motion information to facilitate performance. We sought to address this by two means: first by superimposing arrows on objects which varied in their informativeness about motion direction and second by asking observers to attend to motion direction. Using a position monitoring task, we calculated mean error magnitudes as a measure of the precision with which target positions are represented. We also calculated perceptual lags versus extrapolated reports, which are the times at which positions of targets best match position reports. We find that the presence of motion information in the form of superimposed arrows made no difference to position report precision nor perceptual lag. However, when we explicitly instructed observers to attend to motion, we saw facilitatory effects on position reports and in some cases reports that best matched extrapolated rather than lagging positions for small set sizes. The results indicate that attention to changing positions does not automatically recruit attention to motion, showing a dissociation between sustained attention to changing positions and attention to motion. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Promise of Positive Psychology

Directory of Open Access Journals (Sweden)

Mihaly Csikszentmihalyi

2009-12-01

Full Text Available Positive Psychology has demonstrated its usefulness in studying and contributing to individual well being. The next big challenge for this new field is to help improving the social and cultural conditions in which people live. Three specific goals are discussed: A more complete understanding of human nature; forging a more sustainable and more fair social contract; and a rediscovery of the joys of existence. If Positive Psychology will be able to support these goals, it will become an important contributor to the evolution of human consciousness and the evolution of culture.

Positive streamers in air and nitrogen of varying density: experiments on similarity laws

Energy Technology Data Exchange (ETDEWEB)

Briels, T M P; Van Veldhuizen, E M; Ebert, U [Department of Applied Physics, Technische Universiteit Eindhoven, P O Box 513, 5600 MB Eindhoven (Netherlands)], E-mail: ebert@cwi.nl, E-mail: e.m.v.veldhuizen@tue.nl

2008-12-07

Positive streamers in ambient air at pressures from 0.013 to 1 bar are investigated experimentally. The voltage applied to the anode needle ranges from 5 to 45 kV, the discharge gap from 1 to 16 cm. Using a 'slow' voltage rise time of 100-180 ns, the streamers are intentionally kept thin. For each pressure p, we find a minimal diameter d{sub min}. To test whether streamers at different pressures are similar, the minimal streamer diameter d{sub min} is multiplied by its pressure p; we find this product to be well approximated by p {center_dot} d{sub min} = 0.20 {+-} 0.02 mm bar over two decades of air pressure at room temperature. The value also fits diameters of sprite discharges above thunderclouds at an altitude of 80 km when extrapolated to room temperature (as air density rather than pressure determines the physical behaviour). The minimal velocity of streamers in our measurements is approximately 0.1 mm ns{sup -1} = 10{sup 5} m s{sup -1}. The same minimal velocity has been reported for tendrils in sprites. We also investigate the size of the initial ionization cloud at the electrode tip from which the streamers emerge, and the streamer length between branching events. The same quantities are also measured in nitrogen with a purity of approximately 99.9%. We characterize the essential differences with streamers in air and find a minimal diameter of p {center_dot} d{sub min} = 0.12 {+-} 0.02 mm bar in our nitrogen.

The Online Dissemination of Nature-Health Concepts: Lessons from Sentiment Analysis of Social Media Relating to "Nature-Deficit Disorder".

Science.gov (United States)

Palomino, Marco; Taylor, Tim; Göker, Ayse; Isaacs, John; Warber, Sara

2016-01-19

Evidence continues to grow supporting the idea that restorative environments, green exercise, and nature-based activities positively impact human health. Nature-deficit disorder, a journalistic term proposed to describe the ill effects of people's alienation from nature, is not yet formally recognized as a medical diagnosis. However, over the past decade, the phrase has been enthusiastically taken up by some segments of the lay public. Social media, such as Twitter, with its opportunities to gather "big data" related to public opinions, offers a medium for exploring the discourse and dissemination around nature-deficit disorder and other nature-health concepts. In this paper, we report our experience of collecting more than 175,000 tweets, applying sentiment analysis to measure positive, neutral or negative feelings, and preliminarily mapping the impact on dissemination. Sentiment analysis is currently used to investigate the repercussions of events in social networks, scrutinize opinions about products and services, and understand various aspects of the communication in Web-based communities. Based on a comparison of nature-deficit-disorder "hashtags" and more generic nature hashtags, we make recommendations for the better dissemination of public health messages through changes to the framing of messages. We show the potential of Twitter to aid in better understanding the impact of the natural environment on human health and wellbeing.

Natural circulation cooling in a PWR geometry under accident-induced conditions

International Nuclear Information System (INIS)

Shimeck, D.J.; Johnsen, G.W.

1983-01-01

The characteristics and limits of natural circulation heat rejection over a wide range of conditions were experimentally investigated in a small-scale model of a pressurized water reactor. Conditions that were varied included primary and secondary coolant inventory, decay heat power, and primary noncondensable gas content. The results have defined three distinct modes of natural circulation, their limits and transition points, and the characteristic signatures accompanying natural circulation behavior. Particular emphasis is focused on the limits of natural circulation under severely degraded primary and secondary conditions

Natural and anthropogeneous radiation in the Erzgebirge: Risk factor radon

International Nuclear Information System (INIS)

Jacobi, W.

1992-01-01

The geological formations in the saxoinian-thuringian low mountain range contain rocks with a relatively high share of uranium ( 238 U) and its follow-up product radium ( 226 Ra). Independent of mining this results in increased radiation levels to which the local population has always been exposed. Natural radiation levels may, of course, vary strongly from one location to the next and therefore human exposure varies accordingly. (orig.) [de

Dimensional stability of natural fibers

Energy Technology Data Exchange (ETDEWEB)

Driscoll, Mark S. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 (United States); Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J. [Ultraviolet Light/Electron Beam (UV/EB) Technology Center, State University of New York College of Environmental Science and Forestry (SUNY-ESF), 1 Forestry Drive, Syracuse, NY 13210 and Sustainable Construction Management and Engineering, SUNY-ESF (United States); Larsen, L. Scott [New York State Energy Research and Development Authority (NYSERDA), 17 Columbia Circle, Albany, NY 12203 (United States)

2013-04-19

One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

Dimensional stability of natural fibers

International Nuclear Information System (INIS)

Driscoll, Mark S.; Smith, Jennifer L.; Woods, Sean; Tiss, Kenneth J.; Larsen, L. Scott

2013-01-01

One of the main problems associated with the use of natural fibers as reinforcing agents in composites is their uptake of moisture. Many natural fibers are lignocellulosic, which causes them to swell and shrink as the amount of available moisture changes. Swelling and shrinking can cause composites to prematurely fail. This paper presents the results of a preliminary study that considers the use of two different low molecular weight monomers, hydroxyethyl methacrylate (HEMA) and hydroxyethyl acrylate (HEA), polymerized by electron beam ionizing radiation, to dimensionally stabilize natural fibers. Eight different treatments consisting of varying amounts of monomer, encapsulating agent, and cross-linkers, were evaluated for their ability to dimensionally stabilize sisal fiber. Results indicate that both polymerized HEA and HEMA can reduce the swelling of sisal fiber. The effectiveness of HEA and HEMA can be further enhanced with the use of a cross-linker (SR 454). The use of hydroxylated monomers to dimensionally stabilize natural fibers may play an important role in reducing delamination and improving fiber-resin adhesion in composites.

Changes of ionizing radiation caused by natural radionuclides in the Curonian Spit

International Nuclear Information System (INIS)

Peciuliene, M.; Jasaitis, D.; Grigaliunaite-Vonseviciene, G. and others

2005-01-01

Taking into consideration a unique scenery of the Curonian Spit, dosimetric investigation of ionizing radiation caused by natural radionuclides is performed there. The influence of natural radionuclides present in the ground on the equivalent dose rate of gamma radiation in the ground surface air is established. Measurements of equivalent dose rate are carried out in the whole territory of the Curonian Spit in Lithuania. Especially numerous data have been collected on the coasts of the sea and bay, near them, in seaside dunes and by roads. The established equivalent dose rate values vary from 22 nSv/h (on the dune top) to 90 nSv/h (above an asphalt path). The values of the main gamma radiation source ( 40 K and 226 Ra) concentration are measured, and positive correlation of concentrations and equivalent dose rates in the ground surface air between 40 K and 2 '2 6 Ra is determinated. It is established that 40 K has the biggest influence on equivalent dose rate. The equivalent dose rate values in the ground surface air in the Curonian Spit are comparatively low (they can even be 1630 times lower in comparison to Guarapari beach, Brazil). (author)

Solute concentration at a well in non-Gaussian aquifers under constant and time-varying pumping schedule

Science.gov (United States)

Libera, Arianna; de Barros, Felipe P. J.; Riva, Monica; Guadagnini, Alberto

2017-10-01

Our study is keyed to the analysis of the interplay between engineering factors (i.e., transient pumping rates versus less realistic but commonly analyzed uniform extraction rates) and the heterogeneous structure of the aquifer (as expressed by the probability distribution characterizing transmissivity) on contaminant transport. We explore the joint influence of diverse (a) groundwater pumping schedules (constant and variable in time) and (b) representations of the stochastic heterogeneous transmissivity (T) field on temporal histories of solute concentrations observed at an extraction well. The stochastic nature of T is rendered by modeling its natural logarithm, Y = ln T, through a typical Gaussian representation and the recently introduced Generalized sub-Gaussian (GSG) model. The latter has the unique property to embed scale-dependent non-Gaussian features of the main statistics of Y and its (spatial) increments, which have been documented in a variety of studies. We rely on numerical Monte Carlo simulations and compute the temporal evolution at the well of low order moments of the solute concentration (C), as well as statistics of the peak concentration (Cp), identified as the environmental performance metric of interest in this study. We show that the pumping schedule strongly affects the pattern of the temporal evolution of the first two statistical moments of C, regardless the nature (Gaussian or non-Gaussian) of the underlying Y field, whereas the latter quantitatively influences their magnitude. Our results show that uncertainty associated with C and Cp estimates is larger when operating under a transient extraction scheme than under the action of a uniform withdrawal schedule. The probability density function (PDF) of Cp displays a long positive tail in the presence of time-varying pumping schedule. All these aspects are magnified in the presence of non-Gaussian Y fields. Additionally, the PDF of Cp displays a bimodal shape for all types of pumping

A study of the anti-reflection efficiency of natural nano-arrays of varying sizes

International Nuclear Information System (INIS)

Sun Mingxia; Liang Aiping; Zheng Yongmei; Watson, Gregory S; Watson, Jolanta A

2011-01-01

The dependence of optical reflectivity and wettability on the surface topography of 32 species of cicada wing membranes has been investigated using UV-visible spectrophotometry, contact angle measurements and environmental scanning electron microscopy. The nanoscale hexagonally close packed protrusions have been shown to exhibit an anti-reflection and in some cases an anti-wetting function. The parameters of the structures were measured to be 77-148 nm in diameter, 44-117 nm in spacing and 159-481 nm in height. The transmittance spectrum and static contact angles were measured. At a wavelength range of 500-2500 nm, only minor differences in the anti-reflection performance were observed for each cicada species ascribed to the mechanism of impedance matching between cuticle and air. The transmittance properties of cicada wings were altered successfully through the scanning probe microscope-based manipulation by reducing the protrusion height via the contact mode. A near linear dependence was found between a decrease in protuberance height and a resulting increase in reflectance intensity. A diversity of wettability was observed with contact angles varying from 56.5 0 to 146.0 0 . Both effects of anti-reflection and wettability are dependent on the height of protrusions. The anti-reflection is insensitive when the wavelength is larger than the lateral feature size of the nanostructure. The stronger hydrophobic properties are generally associated with a larger diameter, closer spacing and greater height of protrusions when the wing membrane is intact.

Axisymmetric vibrations of thick shells of revolution having meridionally varying curvature

International Nuclear Information System (INIS)

Suzuki, Katsuyoshi; Kosawada, Tadashi; Takahashi, Shin; Takahashi, Fumiaki.

1987-01-01

An exact method using power series expansions is presented for solving axisymmetric free vibration problems for thick shells of revolution having meridionally varying curvature. Based on the improved thick shell theory, the Lagrangian of the shells of revolution are obtained, and the equations of motion and the boundary conditions are derived from the stationary condition of the Lagrangian. The method is applied to thick shells of revolution having their generating curves of ellipse, cycloid, parabola, catenary and hyperbola. The results by the present method are compared with those by the thin shell theory and the effects of rotatory inertia and shear deformation upon the natural frequencies and the mode shapes are clarified. (author)

Canadian natural gas

International Nuclear Information System (INIS)

Lucas, D.A.

1991-01-01

Canada's natural gas industry enjoys a quiet confidence as it looks ahead to the 1990s. In this paper, the author explains why, despite some critical uncertainties, the optimism endures. Reviewing the current conditions of supply, production, consumption, pipelines, and pipeline expansion plans, the author contends that the New World of the 1990s will belong to natural gas. The author's assessment of natural gas markets proceeds far beyond the borders of Canada. The author examines the determinants of gas prices throughout North America and he identifies the one force that promises to seize almost complete control of gas prices throughout the continent. While the analysis points out the attributes of this new pricing regime, it also names the obstacles that could prevent this emerging mechanism from assuming its anticipated position

Soil Redox Dynamics Vary with Landscape Position and Hydroperiod in the Pantanal Wetland Ecosystem

Science.gov (United States)

Couto, E. G.; Johnson, M. S.; Pinto-jr, O.; Leite, N. K.

2012-12-01

The Pantanal wetland ecosystem of central South America is the largest tropical wetland complex in the world. Nevertheless, biogeochemistry in the Pantanal is quite limited. A unimodal precipitation regime averages approximately 1200 mm y-1 during the six-month rainy season, leading to seasonal flooding on much, but not all, of the landscape. We investigated the impact of landscape position and hydroperiod on soil redox potential (Eh) in four research locations in the Northern Pantanal near Poconé, Mato Grosso: two locations subject to flooding (a flooded forest and a flooded scrub forest) and two locations with infrequent surface flooding (tree islands known as cordilheiras). Redox sensors were installed at 10 cm and 30 cm depths at each of the four locations with half-hourly data recorded over all hydro-periods (dry season, rising water, flood and falling water). Here we summarize results to date in this ongoing study. Reducing conditions were observed in response to both precipitation events saturating soil from the surface downward, as well as in response to regional flooding dynamics that saturate soil from below. These are helping to guide design of a study on methane dynamics in the Pantanal wetland complex.

Natural aphrodisiacs.

Science.gov (United States)

Shamloul, Rany

2010-01-01

The search for a remedy or a prescription that can enhance sexual function and/or treat male erectile dysfunction has been an obsession throughout known history. Whether it was an Eastern civilization or a Western one, religious or atheist, man's aspiration for a better or best "manhood" has been a history-time goal. This review will discuss the current research done on the most popular natural aphrodisiacs and examine the weight of evidence to support or discourage the use of any of these substances to enhance sexual desire and/or function. Review of the current evidence on the use of natural substances as aphrodisiacs. Efficacy of natural aphrodisiacs in enhancing sexual function in men and women. There is little evidence from literature to recommend the usage of natural aphrodisiacs for the enhancement of sexual desire and/or performance. Data on yohimbine's efficacy does not support the wide use of the drug, which has only mild effects in the treatment of psychogenic ED. Although there's a positive trend towards recommending ginseng as an effective aphrodisiac, however, more in depth studies involving large number of subjects and its mechanism of action are needed before definite conclusions could be reached. Data on the use of natural aphrodisiacs in women is limited. The current body of objective evidence does not support the use of any natural aphrodisiac as an effective treatment for male or female sexual dysfunctions. Potent men and men with ED will continue the search for natural aphrodisiacs despite the current disappointing data on their effectiveness. Care should be taken regarding the fraud addition of sildenafil analogues to natural aphrodisiacs.

Natural cold pressed oils as cosmetic products

Directory of Open Access Journals (Sweden)

Małgorzata Ligęza

2016-12-01

Full Text Available Background. It seems that patients may ask general practitioners about natural cosmetics applied on the skin regarding their safety and suitability. Objectives. The aim of the study was to analyze natural cold pressed oils as potential cosmetic products. Material and methods. Cold pressed oils obtained from selected seeds and fruit stones were analyzed, including: chokeberry seed oil, blackcurrant seed oil, elderberry seed oil, raspberry seed oil, apricot seed oil, tomato seed oil, strawberry seed oil, broccoli seed oil, Nigella sativa seed oil, hemp oil, safflower seed oil, Silybum marianum seed oil and coconut oil. 80 adult volunteers assessed the cosmetic properties of the analyzed oils. Each of the volunteers tested 2 to 4 different oils, by applying them on the skin. In addition, patch tests with all analyzed oils were performed on 23 individuals. Results. The majority of tested oils were positively evaluated by the participants: in the opinion of the participants, oil extracted from safflower had the best appearance (100% positive opinions, coconut oil had the best smell (70% positive opinions, while black currant seed oil showed the best absorbency (85% positive opinions. No irritation was observed within the analyzed product group, albeit one allergic reaction to apricot seed oil was observed with patch testing. Conclusions . Based on the achieved results, it could be suggested that natural cold pressed oils can be applied to the skin as cosmetics. Our observations may be helpful for general practitioners when choosing natural cosmetics.

Natural radioactivity of Turkish natural stones as building materials

International Nuclear Information System (INIS)

Yaprak, Guenseli; Yasar, Oezden

2008-01-01

Full text: The Turkey has very important natural stones potential with over 5 billion m 3 marble reserves. According to 2002 giving data the number of Turkish stones export is 303 million US Dollars. In this regards, the present study deals with 90 Turkish natural stones. The studied samples were analyzed and the concentrations in Bq/kg dry weight of radioisotopes were determined by gamma-ray spectrometry using HPGe detector. The radon exhalation rates of natural stones were also measured by using solid state nuclear track detectors (LR-115 ). The radium equivalent activity varied from 183 Bq/kg to 522 Bq/kg for granite samples and from 1 Bq/kg to 37 Bq/kg for marble samples. The value of radon exhalation rate ranged from 0.003 Bq/m 2 h -1 to 0.768 Bq/m 2 h -1 for granite samples and from 0.001 Bq/m 2 h -1 to 0.02 Bq/m 2 h -1 for marble samples. The total absorbed dose rates in air ranged from 22 to 61 n Gy h -1 for one quarter utilization of granite samples. The annual effective dose rates per person indoors were determined to be between 108 and 298 μSv y -1 for of for one quarter utilization of the materials. Applying the dose criteria recently recommended by UNSCEAR for building materials, the natural stones meet the upper dose limit of 1mSvy -1 . So, there are not restrictions for use of any Turkish commercial marble as covering materials, including Turkish granites. (author)

The Impact of Varying Statutory Arrangements on Spatial Data Sharing and Access in Regional NRM Bodies

Science.gov (United States)

Paudyal, D. R.; McDougall, K.; Apan, A.

2014-12-01

Spatial information plays an important role in many social, environmental and economic decisions and increasingly acknowledged as a national resource essential for wider societal and environmental benefits. Natural Resource Management is one area where spatial information can be used for improved planning and decision making processes. In Australia, state government organisations are the custodians of spatial information necessary for natural resource management and regional NRM bodies are responsible to regional delivery of NRM activities. The access and sharing of spatial information between government agencies and regional NRM bodies is therefore as an important issue for improving natural resource management outcomes. The aim of this paper is to evaluate the current status of spatial information access, sharing and use with varying statutory arrangements and its impacts on spatial data infrastructure (SDI) development in catchment management sector in Australia. Further, it critically examined whether any trends and significant variations exist due to different institutional arrangements (statutory versus non-statutory) or not. A survey method was used to collect primary data from 56 regional natural resource management (NRM) bodies responsible for catchment management in Australia. Descriptive statistics method was used to show the similarities and differences between statutory and non-statutory arrangements. The key factors which influence sharing and access to spatial information are also explored. The results show the current statutory and administrative arrangements and regional focus for natural resource management is reasonable from a spatial information management perspective and provides an opportunity for building SDI at the catchment scale. However, effective institutional arrangements should align catchment SDI development activities with sub-national and national SDI development activities to address catchment management issues. We found minor

World statistics on natural gas reserves, production and utilization

International Nuclear Information System (INIS)

Raikaslehto, S.

2001-01-01

By reviewing the statistics of BP Amoco on natural gas reserves, production and usage, it is easy to see that Russia and USA, both being large natural gas producers, differ significantly from each other. The natural gas reserves of USA are 6th largest in the world, simultaneously the natural gas consumption and import are largest in the world. About one third of the known natural gas reserves of the world are in Russia. The known natural gas reserves of both USA and Canada have decreases, but they have potential gas reserves left. Known natural gas reserves of the USA have been calculated to be sufficient for 9 years consumption at present usage and those of Canada for 11 years. The reserves of Algeria correspond to the usage of 55 years, and the Russian reserves for are about 83 years. Annual production figures of both Russia and the USA are nearly the same. Russia is the largest exporter (125.5 billion m 3 ) of natural gas and the USA the largest importer (96 billion m 3 ). The natural gas reserves of the largest European producers, the Netherlands and Norway have been estimated to be sufficient for use of about 20 years, but those of Great Britain only for about 10 years. The annual production of Russia has varied in the 1990s between nearly 600 billion m 3 and present 550 billion m 3 , the minimum being in 1997 only about 532 billion m 3 . Ten largest natural gas consumers use 67% of the natural gas consumed annually in the world. USA consumes about 27% of the total natural gas produced in the world, the amount of Russia being 364 billion m 3 (16%). Other large natural gas consumers are Great Britain, Germany, Japan, Ukraine, Canada, Italy, Iran and Uzbekistan. The share of these countries of the total consumption varied in between 2-4%. Only Japan has no natural gas production of its own. The foreign trade between Japan and Indonesia is trade on LNG. On the other hand the natural gas consumption of the world's 10th largest producer Norway is nearly zero, so

Heat treatment and false-positive heartworm antigen testing in ex vivo parasites and dogs naturally infected by Dirofilaria repens and Angiostrongylus vasorum

Directory of Open Access Journals (Sweden)

Luigi Venco

2017-11-01

Full Text Available Abstract Background Heartworm antigen testing is considered sensitive and specific. Currently available tests are reported as detecting a glycoprotein found predominantly in the reproductive tract of the female worm and can reach specificity close to 100%. Main concerns regard sensitivity in the case of light infections, the presence of immature females or cases of all-male infections. Research and development have been aimed at increasing sensitivity. Recently, heat treatment of serum prior to antigen testing has been shown to result in an increase in positive antigen test results, presumably due to disruption of natural antigen–antibody complexes. Cross-reactions in dogs with both natural and experimental infections with Angiostrongylus vasorum and Spirocerca lupi have been reported, but cross-reactions with other helminths have not been extensively studied. In order to evaluate potential cross-reactivity with other canine and feline parasites, two studies were performed. Study 1: Live adults of Dirofilaria immitis, Dirofilaria repens, Toxocara canis, Toxocara cati, Dipylidium caninum, Taenia taeniaeformis and Mesocestoides spp. larvae were washed and incubated in tubes with saline solution. All worms were alive at the time of removal from the saline. Saline solutions containing excretory/secretory antigens were then tested for heartworm with six different, commercially available antigen tests. All results were evaluated blind by three of the authors. Study 2: Sera from dogs with natural infections by A. vasorum or D. repens, living in areas free of heartworm disease, were tested with the same tests before and after heat treatment (103 °C for 10 min. Results Results suggest that antigens detected by currently available tests are not specific for D. immitis. They may give positive results through detection of different parasites’ antigens that are normally not released into the bloodstream or released in a low amount and/or bound to

Large-timestep techniques for particle-in-cell simulation of systems with applied fields that vary rapidly in space

International Nuclear Information System (INIS)

Friedman, A.; Grote, D.P.

1996-10-01

Under conditions which arise commonly in space-charge-dominated beam applications, the applied focusing, bending, and accelerating fields vary rapidly with axial position, while the self-fields (which are, on average, comparable in strength to the applied fields) vary smoothly. In such cases it is desirable to employ timesteps which advance the particles over distances greater than the characteristic scales over which the applied fields vary. Several related concepts are potentially applicable: sub-cycling of the particle advance relative to the field solution, a higher-order time-advance algorithm, force-averaging by integration along approximate orbits, and orbit-averaging. We report on our investigations into the utility of such techniques for systems typical of those encountered in accelerator studies for heavy-ion beam-driven inertial fusion

Restorative Qualities of and Preference for Natural and Urban Soundscapes.

Science.gov (United States)

Krzywicka, Paulina; Byrka, Katarzyna

2017-01-01

Psychological restoration in urban agglomerations has become a growing challenge. Although scientific proof of the significance of nature is irrefutable, an increase in built-up areas has led to a decrease in urban greenery. Thus, a growing need for restorativeness in urban surroundings has emerged. To investigate whether positively evaluated sonic environments, represented by natural and urban sounds, have comparable restorative qualities we conducted two studies. The aim of the first (Study 1) was to explore the restorative qualities of positively assessed natural and urban sounds. Participants ( N = 88) were asked to listen and to rate 22 recordings (each 1 min long) either from natural or urban environments. In the second (Study 2) we investigated whether positively evaluated sonic environments (natural and urban), demand for restoration (feeling relaxed or fatigued) and company (being alone or with a friend) affect the restorative qualities of natural and urban soundscapes. After reading assigned scenarios (feeling relaxed or fatigued; being alone or with a friend), participants ( N = 120) were asked to imagine a walk in presented sonic environments and to complete forms (one for each sonic environment) concerning the restorative qualities of given soundscapes (natural and urban). Top five recordings of natural and urban sonic environments were selected from Study 1 and combined into a 154-s soundtrack, to provide a background for the imagined walks in both settings. Our findings confirmed that natural sounds are perceived more favorably than urban recordings. Even when only the most positively assessed soundscapes were compared, nature was still perceived as being more restorative than urban areas. Company of a friend was found to be more beneficial in the urban surroundings, particularly when there was no need for restoration.

Restorative Qualities of and Preference for Natural and Urban Soundscapes

Directory of Open Access Journals (Sweden)

Paulina Krzywicka

2017-10-01

Full Text Available Psychological restoration in urban agglomerations has become a growing challenge. Although scientific proof of the significance of nature is irrefutable, an increase in built-up areas has led to a decrease in urban greenery. Thus, a growing need for restorativeness in urban surroundings has emerged. To investigate whether positively evaluated sonic environments, represented by natural and urban sounds, have comparable restorative qualities we conducted two studies. The aim of the first (Study 1 was to explore the restorative qualities of positively assessed natural and urban sounds. Participants (N = 88 were asked to listen and to rate 22 recordings (each 1 min long either from natural or urban environments. In the second (Study 2 we investigated whether positively evaluated sonic environments (natural and urban, demand for restoration (feeling relaxed or fatigued and company (being alone or with a friend affect the restorative qualities of natural and urban soundscapes. After reading assigned scenarios (feeling relaxed or fatigued; being alone or with a friend, participants (N = 120 were asked to imagine a walk in presented sonic environments and to complete forms (one for each sonic environment concerning the restorative qualities of given soundscapes (natural and urban. Top five recordings of natural and urban sonic environments were selected from Study 1 and combined into a 154-s soundtrack, to provide a background for the imagined walks in both settings. Our findings confirmed that natural sounds are perceived more favorably than urban recordings. Even when only the most positively assessed soundscapes were compared, nature was still perceived as being more restorative than urban areas. Company of a friend was found to be more beneficial in the urban surroundings, particularly when there was no need for restoration.

Adaptive sliding control of non-autonomous active suspension systems with time-varying loadings

Science.gov (United States)

Chen, Po-Chang; Huang, An-Chyau

2005-04-01

An adaptive sliding controller is proposed in this paper for controlling a non-autonomous quarter-car suspension system with time-varying loadings. The bound of the car-body loading is assumed to be available. Then, the reference coordinate is placed at the static position under the nominal loading so that the system dynamic equation is derived. Due to spring nonlinearities, the system property becomes asymmetric after coordinate transformation. Besides, in practical cases, system parameters are not easy to be obtained precisely for controller design. Therefore, in this paper, system uncertainties are lumped into two unknown time-varying functions. Since the variation bound of one of the unknown functions is not available, conventional adaptive schemes and robust designs are not applicable. To deal with this problem, the function approximation technique is employed to represent the unknown function as a finite combination of basis functions. The Lyapunov direct method can thus be used to find adaptive laws for updating coefficients in the approximating series and to prove stability of the closed-loop system. Since the position and velocity measurements of the unsprung mass are lumped into the unknown function, there is no need to install sensors on the axle and wheel assembly in the actual implementation. Simulation results are presented to show the performance of the proposed strategy.

Nature: a new paradigm for well-being and ergonomics.

Science.gov (United States)

Richardson, Miles; Maspero, Marta; Golightly, David; Sheffield, David; Staples, Vicki; Lumber, Ryan

2017-02-01

Nature is presented as a new paradigm for ergonomics. As a discipline concerned with well-being, the importance of natural environments for wellness should be part of ergonomics knowledge and practice. This position is supported by providing a concise summary of the evidence of the value of the natural environment to well-being. Further, an emerging body of research has found relationships between well-being and a connection to nature, a concept that reveals the integrative character of human experience which can inform wider practice and epistemology in ergonomics. Practitioners are encouraged to bring nature into the workplace, so that ergonomics keeps pace with the move to nature-based solutions, but also as a necessity in the current ecological and social context. Practitioner Summary: Nature-based solutions are coming to the fore to address societal challenges such as well-being. As ergonomics is concerned with well-being, there is a need for a paradigm shift in the discipline. This position is supported by providing a concise summary of the evidence of the value of the natural environment to well-being.

5 CFR 307.103 - Nature of VRAs.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Nature of VRAs. 307.103 Section 307.103 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS VETERANS RECRUITMENT APPOINTMENTS § 307.103 Nature of VRAs. VRAs are excepted appointments, made without competition, to positions...

Vibration condition monitoring of planetary gearbox under varying external load

Energy Technology Data Exchange (ETDEWEB)

Bartelmus, W.; Zimroz, R. [Wroclaw University of Technology, Wroclaw (Poland)

2009-01-15

The paper shows that for condition monitoring of planetary gearboxes it is important to identify the external varying load condition. In the paper, systematic consideration has been taken of the influence of many factors on the vibration signals generated by a system in which a planetary gearbox is included. These considerations give the basis for vibration signal interpretation, development of the means of condition monitoring, and for the scenario of the degradation of the planetary gearbox. Real measured vibration signals obtained in the industrial environment are processed. The signals are recorded during normal operation of the diagnosed objects, namely planetary gearboxes, which are a part of the driving system used in a bucket wheel excavator, used in lignite mines. It has been found that the most important factor of the proper planetary gearbox condition is connected with perturbation of arm rotation, where an arm rotation gives rise to a specific vibration signal whose properties are depicted by a short-time Fourier transform (STFT) and Wigner-Ville distribution presented as a time-frequency map. The paper gives evidence that there are two dominant low-frequency causes that influence vibration signal modulation, i.e. the varying load, which comes from the nature of the bucket wheel digging process, and the arm/carrier rotation. These two causes determine the condition of the planetary gearboxes considered.

Off-Line Robust Constrained MPC for Linear Time-Varying Systems with Persistent Disturbances

Directory of Open Access Journals (Sweden)

P. Bumroongsri

2014-01-01

Full Text Available An off-line robust constrained model predictive control (MPC algorithm for linear time-varying (LTV systems is developed. A novel feature is the fact that both model uncertainty and bounded additive disturbance are explicitly taken into account in the off-line formulation of MPC. In order to reduce the on-line computational burdens, a sequence of explicit control laws corresponding to a sequence of positively invariant sets is computed off-line. At each sampling time, the smallest positively invariant set containing the measured state is determined and the corresponding control law is implemented in the process. The proposed MPC algorithm can guarantee robust stability while ensuring the satisfaction of input and output constraints. The effectiveness of the proposed MPC algorithm is illustrated by two examples.

The effect of positive affect on conflict resolution: Modulated by approach-motivational intensity.

Science.gov (United States)

Liu, Ya; Wang, Zhenhong; Quan, Sixiang; Li, Mingjun

2017-01-01

The motivational dimensional model of affect proposes that the influence of positive affect on cognitive processing is modulated by approach-motivational intensity. The present research extended this model by examining the influence of positive affect varying in approach-motivational intensity on conflict resolution-the ability to resolve interference from task-irrelevant distractors in order to focus on the target. The global-local task (Experiment 1) and letter-Flanker task (Experiment 2) were used to measure conflict resolution. Additionally, the 4:2 mapping design that assigns two kinds of task-relevant stimuli to one response key and two more to another response key was used in these two tasks to dissociate stimulus and response conflict. Results showed that positive affect varying in approach motivation had opposite influences on conflict resolution. The opposite influences are primarily reflected in low approach-motivated positive affect impairing, while high approach-motivated positive affect facilitating the resolution of response conflict. Conversely, the stimulus conflict was slightly influenced. These findings highlight the utility of distinguishing stimulus and response conflict in future research.

How gut transcriptional function of Drosophila melanogaster varies with the presence and composition of the gut microbiota.

Science.gov (United States)

Bost, Alyssa; Franzenburg, Soeren; Adair, Karen L; Martinson, Vincent G; Loeb, Greg; Douglas, Angela E

2018-04-01

Despite evidence from laboratory experiments that perturbation of the gut microbiota affects many traits of the animal host, our understanding of the effect of variation in microbiota composition on animals in natural populations is very limited. The core purpose of this study on the fruit fly Drosophila melanogaster was to identify the impact of natural variation in the taxonomic composition of gut bacterial communities on host traits, with the gut transcriptome as a molecular index of microbiota-responsive host traits. Use of the gut transcriptome was validated by demonstrating significant transcriptional differences between the guts of laboratory flies colonized with bacteria and maintained under axenic conditions. Wild Drosophila from six field collections made over two years had gut bacterial communities of diverse composition, dominated to varying extents by Acetobacteraceae and Enterobacteriaceae. The gut transcriptomes also varied among collections and differed markedly from those of laboratory flies. However, no overall relationship between variation in the wild fly transcriptome and taxonomic composition of the gut microbiota was evident at all taxonomic scales of bacteria tested for both individual fly genes and functional categories in Gene Ontology. We conclude that the interaction between microbiota composition and host functional traits may be confounded by uncontrolled variation in both ecological circumstance and host traits (e.g., genotype, age physiological condition) under natural conditions, and that microbiota effects on host traits identified in the laboratory should, therefore, be extrapolated to field population with great caution. © 2017 John Wiley & Sons Ltd.

Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

International Nuclear Information System (INIS)

Winterle, Bret

2001-01-01

Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

Effects of varying the longitudinal dispersion and no drip cask rate failures upon Yucca Mountain site performance

Energy Technology Data Exchange (ETDEWEB)

Winterle, Bret

2001-07-01

Proposed changes in the regulatory time limits used for viability assessments of the proposed national high-level radioactive waste repository in Yucca Mountain, Nevada from 10,000 years to 100,000 or even 1,000,000 years call into question both the modelling techniques used to represent the repository's long-term performance, and our ability to extrapolate technological, climatological and geological phenomenon. Using a high-powered risk-assessment software program called Goldsim that a simplified total system performance assessment (STSPA) was designed for, the effects of varying the performance parameters of two barrier systems, one natural and one man-made, upon the total system performance were observed. The conclusion reached by varying these two parameters is that for a regulatory guideline of 10,000 years, there is no noticeable effect on the total system performance, but at 300,000 years, it appears that the effect of reducing the longitudinal dispersion rate (a natural barrier) by one order of magnitude produced an astronomically high receptor dose, indicating that as predicted, our abilities to model situations beyond our ability to accurately extrapolate current scientific research is futile. (author)

Managing soil natural capital

DEFF Research Database (Denmark)

Cong, Ronggang; Termansen, Mette; Brady, Mark

2017-01-01

Farmers are exposed to substantial weather and market related risks. Rational farmers seek to avoid large losses. Future climate change and energy price fluctuations therefore make adaptating to increased risks particularly important for them. Managing soil natural capital—the capacity of the soil...... to generate ecosystem services of benefit to farmers—has been proven to generate the double dividend: increasing farm profit and reducing associated risk. In this paper we explore whether managing soil natural capital has a third dividend: reducing the downside risk (increasing the positive skewness of profit......). This we refer to as the prudence effect which can be viewed as an adaptation strategy for dealing with future uncertainties through more prudent management of soil natural capital. We do this by developing a dynamic stochastic portfolio model to optimize the stock of soil natural capital—as indicated...

New methods for assessing the fascinating nature of nature experiences.

Science.gov (United States)

Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

2013-01-01

In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual's mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an "attentional", an "affective" and an "effort" dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks.

Study on the natural air cooling design of electronic equipment casings: Effects of the height and size of outlet vent on the flow resistances

International Nuclear Information System (INIS)

Ishizuka, M; Hatakeyama, T; Kibushi, R; Inoue, M

2012-01-01

This paper describes the effects of the outlet vent size and the distance between the outlet vent location and the power heater position on the flow resistance in natural-air-cooled electronic equipment casings. An experiment was carried out using a simple model casing simulated for the practical natural-air-cooled casing which is composed of 4 side walls, a top plate and bottom plate which has an inlet opening. A power heater to served as a power dissipation unit was placed at its open bottom. An outlet opening was set on one of the side walls. The opening area, the height of the outlet and the heater location were varied. The experimental results were analyzed using the flow resistance coefficient K which was related to the distance between the outlet vent and the power heater position and the heat removal from the outlet vent, and K values were plotted against a pair of Reynolds numbers Re and the outlet vent porosity β which is defined as the ratio of outlet vent open area to the top surface area of the casing.

Natural gas outlook

International Nuclear Information System (INIS)

Molyneaux, M.P.

1998-01-01

An overview of natural gas markets in Canada and in the United States was provided. The major factors that determine the direction of natural gas prices were depicted graphically. Price volatility has decreased in recent months. As expected, April through November total energy consumption reached historically high levels. Demand for natural gas during the summer of 1997 was not as strong as anticipated. Nuclear energy appears to be on the slippery slope, with natural gas-driven electricity projects to fill the void. Hydroelectricity had a strong showing in 1997. Prospects are less bright for 1998 due to above average temperatures. Canadian natural gas export capacity has increased 5.5 times between 1986 and estimated 1999 levels. Despite this, in 1997, deliveries to the United States were marginally behind expectations. Natural gas consumption, comparative fuel prices, natural gas drilling activity, natural gas storage capacity, actual storage by region, and average weekly spot natural gas prices, for both the U. S. and Canada, were also provided. With regard to Canada, it was suggested that Canadian producers are well positioned for a significant increase in their price realization mostly because of the increase in Canada's export capacity in 1997 (+175 Mmcf/d), 1998 (1,060 Mmcf/d) and potentially in 1999 or 2000, via the Alliance Pipeline project. Nevertheless, with current production projections it appears next to impossible to fill the 10.9 Bcf/d of export capacity that will be potentially in place by the end of 1999. tabs., figs

Liquid natural gas occupies an increasing position in the energy mix of the USA

International Nuclear Information System (INIS)

2002-01-01

Although the profitability of using liquid natural gas (LNG) depends on the fluctuations of the gas price, LNG will play an increasing role in the ''energy mix'' of the USA. The amount of LNG imported by the USA rose by 175% from 1998 to 2001. There are at present four receiving stations for LNG in the USA and they will probably be extended. Plans to build gas-powered power stations in California will increase the demand for natural gas in the coming years. Several companies have announced their desire to build receiving stations for LNG. There is, however, some opposition from environmentalists

Fertility desire and family-planning demand among HIV-positive ...

African Journals Online (AJOL)

Little information exists about desire to have children and family-planning use among HIV-positive individuals and how this may vary according to individual, social, health and demographic characteristics, especially in developing countries. To assess these topics in Ethiopia, a facility-based cross-sectional study was ...

Exponential Stability of Switched Positive Homogeneous Systems

Directory of Open Access Journals (Sweden)

Dadong Tian

2017-01-01

Full Text Available This paper studies the exponential stability of switched positive nonlinear systems defined by cooperative and homogeneous vector fields. In order to capture the decay rate of such systems, we first consider the subsystems. A sufficient condition for exponential stability of subsystems with time-varying delays is derived. In particular, for the corresponding delay-free systems, we prove that this sufficient condition is also necessary. Then, we present a sufficient condition of exponential stability under minimum dwell time switching for the switched positive nonlinear systems. Some results in the previous literature are extended. Finally, a numerical example is given to demonstrate the effectiveness of the obtained results.

Natural gas foothold in world energy market

International Nuclear Information System (INIS)

D'Ermo, V.; Forli, C.

1991-01-01

In this article, the expansion of natural gas from the '50s to the early '80s is analyzed. Following its positive success in industrial, residential and thermoelectric uses, natural gas still has new market spaces to win both in conventional and technical and process innovation-oriented industries

An Environmental Approach to Positive Emotion: Flowers

Directory of Open Access Journals (Sweden)

Jeannette Haviland-Jones

2005-01-01

Full Text Available For more than 5000 years, people have cultivated flowers although there is no known reward for this costly behavior. In three different studies we show that flowers are a powerful positive emotion “inducer”. In Study 1, flowers, upon presentation to women, always elicited the Duchenne or true smile. Women who received flowers reported more positive moods 3 days later. In Study 2, a flower given to men or women in an elevator elicited more positive social behavior than other stimuli. In Study 3, flowers presented to elderly participants (55+ age elicited positive mood reports and improved episodic memory. Flowers have immediate and long-term effects on emotional reactions, mood, social behaviors and even memory for both males and females. There is little existing theory in any discipline that explains these findings. We suggest that cultivated flowers are rewarding because they have evolved to rapidly induce positive emotion in humans, just as other plants have evolved to induce varying behavioral responses in a wide variety of species leading to the dispersal or propagation of the plants.

An experimental study of the effect of green positioning on brand attitude

OpenAIRE

PATRIK HARTMANN; VANESSA APAOLAZA IBÁÑEZ; F. JAVIER FORCADA SAIZ

2004-01-01

Reducing the environmental impact of a product or its manufacturing process not necessarily limits the company’s activities. In the context of a green branding strategy, it might as well open new business opportunities. Ecological positioning provides a strategic tool for the active implementation of green brands. The empirical study shows that more positive attitudes are developed towards a brand positioned by environmental attributes and that these effects vary as a result of the implementa...

Human Nature, Flourishing, and Happiness: Toward a Synthesis of Aristotelianism, Austrian Economics, Positive Psychology, and Ayn Rand’s Objectivism

Directory of Open Access Journals (Sweden)

Edward W. Younkins

2010-11-01

Full Text Available This article presents a skeleton of a potential paradigm of human flourishing and happiness in a free society. It is an exploratory attempt to construct an understanding from various disciplines and to integrate them into a clear, consistent, coherent, and systematic whole. Holding that there are essential interconnections among objective ideas, the article specifically emphasizes the compatibility of Aristotelianism, Austrian Economics, Positive Psychology, and Ayn Rand’s Objectivism arguing that particular ideas from these areas can be integrated into a paradigm of human flourishing and happiness based on the nature of man and the world. Such a paradigm will help people to understand the world and to survive and flourish in it. It is hoped that the paradigm will grow and evolve as scholars engage, question, critique, interpret, and extend its ideas. Our goal is to have a paradigm that accords with reality and there is always more to learn from reality.

Regularization of positive definite matrix fields based on multiplicative calculus

NARCIS (Netherlands)

Florack, L.M.J.; Bruckstein, A.M.; Haar Romeny, ter B.M.; Bronstein, A.M.; Bronstein, M.M.

2012-01-01

Multiplicative calculus provides a natural framework in problems involving positive images and positivity preserving operators. In increasingly important, complex imaging frameworks, such as diffusion tensor imaging, it complements standard calculus in a nontrivial way. The purpose of this article

Evidence for subwavelength imaging with positive refraction

Energy Technology Data Exchange (ETDEWEB)

Ma, Yun Gui [Temasek Laboratories, National University of Singapore, Singapore 119260 (Singapore); Sahebdivan, Sahar; Tyc, Tomas; Leonhardt, Ulf [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Ong, C K, E-mail: ulf@st-andrews.ac.uk [Centre for Superconducting and Magnetic Materials, Department of Physics, National University of Singapore, Singapore 117542 (Singapore)

2011-03-15

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction.

Evidence for subwavelength imaging with positive refraction

International Nuclear Information System (INIS)

Ma, Yun Gui; Sahebdivan, Sahar; Tyc, Tomas; Leonhardt, Ulf; Ong, C K

2011-01-01

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction.

La sylviculture proche de la nature face au conflit économie-écologie : panacée ou illusion ?

Directory of Open Access Journals (Sweden)

Jean-Philippe Schütz

1997-01-01

Full Text Available Near-to-nature sylviculture in view of the conflict economy-ecology: panacea or illusion?The concept of near-to-nature sylviculture is open to varying ways of interpretation which mainly depend on the emphasis given to the terni of "culture" and "nature" and the values we associate with these two key expressions. It is, however, not a new concept; it dates back to the last century's sylvicultural conception developed by Karl Gayer. This very form of forest management bas been practised for more than a century in Switzerland; the experience gained is presented here. Sylviculture based on the principle of free use of cuttings is a remarkably liberal concept. It differs essentially from other, stricter concepts derived from the ideology of the perpetuating forest according to Môller. Using the principle of free use of cuttings, the aim is to revaluate the position of the sylviculture with regard to forest management, whose role is control and follow up. This liberal form of combining the principles of naturalness and multifunctionality appears to bc remarkably modern if the need to favour diversity is added. The whole is connected to the fact that current economic conditions are becoming less and less favourable.

Conceptual Analysis: The Charcoal-Agriculture Nexus to Understand the Socio-Ecological Contexts Underlying Varied Sustainability Outcomes in African Landscapes

Directory of Open Access Journals (Sweden)

Miyuki Iiyama

2017-06-01

Full Text Available The production of charcoal is an important socio-economic activity in sub-Saharan Africa (SSA. Charcoal production is one of the leading drivers of rural land-use changes in SSA, although the intensity of impacts on the multi-functionality of landscapes varies considerably. Within a given landscape, charcoal production is closely interconnected to agriculture production both as major livelihoods, while both critically depend on the same ecosystem services. The interactions between charcoal and agricultural production systems can lead to positive synergies of impacts, but will more often result in trade-offs and even vicious cycles. Such sustainability outcomes vary from one site to another due to the heterogeneity of contexts, including agricultural production systems that affect the adoption of technologies and practices. Trade-offs or cases of vicious cycles occur when one-off resource exploitation of natural trees for charcoal production for short-term economic gains permanently impairs ecosystem functions. Given the fact that charcoal, as an important energy source for the growing urban populations and an essential livelihood for the rural populations, cannot be readily substituted in SSA, there must be policies to support charcoal production. Policies should encourage sustainable technologies and practices, either by establishing plantations or by encouraging regeneration, whichever is more suitable for the local environment. To guide context-specific interventions, this paper presents a new perspective—the charcoal-agriculture nexus—aimed at facilitating the understanding of the socio-economic and ecological interactions of charcoal and agricultural production. The nexus especially highlights two dimensions of the socio-ecological contexts: charcoal value chains and tenure systems. Combinations of the two are assumed to underlie varied socio-economic and ecological sustainability outcomes by conditioning incentive mechanisms to affect

Varied Practice in Laparoscopy Training: Beneficial Learning Stimulation or Cognitive Overload?

Science.gov (United States)

Spruit, Edward N; Kleijweg, Luca; Band, Guido P H; Hamming, Jaap F

2016-01-01

Determining the optimal design for surgical skills training is an ongoing research endeavor. In education literature, varied practice is listed as a positive intervention to improve acquisition of knowledge and motor skills. In the current study we tested the effectiveness of a varied practice intervention during laparoscopy training. Twenty-four trainees (control group) without prior experience received a 3 weeks laparoscopic skills training utilizing four basic and one advanced training task. Twenty-eight trainees (experimental group) received the same training with a random training task schedule, more frequent task switching and inverted viewing conditions on the four basic training tasks, but not the advanced task. Results showed inferior performance of the experimental group on the four basic laparoscopy tasks during training, at the end of training and at a 2 months retention session. We assume the inverted viewing conditions have led to the deterioration of learning in the experimental group because no significant differences were found between groups on the only task that had not been practiced under inverted viewing conditions; the advanced laparoscopic task. Potential moderating effects of inter-task similarity, task complexity, and trainee characteristics are discussed.

Varied Practice in Laparoscopy Training: Beneficial Learning Stimulation or Cognitive Overload?

Directory of Open Access Journals (Sweden)

Edward N. eSpruit

2016-05-01

Full Text Available AbstractDetermining the optimal design for surgical skills training is an ongoing research endeavor. In education literature, varied practice is listed as a positive intervention to improve acquisition of knowledge and motor skills. In the current study we tested the effectiveness of a varied practice intervention during laparoscopy training. 24 trainees (control group without prior experience received a three week laparoscopic skills training utilizing four basic and one advanced training task. 28 trainees (experimental group received the same training with a random training task schedule, more frequent task switching and inverted viewing conditions on the four basic training tasks, but not the advanced task. Results showed inferior performance of the experimental group on the four basic laparoscopy tasks during training, at the end of training and at a two month retention session. We assume the inverted viewing conditions have led to the deterioration of learning in the experimental group because no significant differences were found between groups on the only task that had not been practiced under inverted viewing conditions; the advanced laparoscopic task. Potential moderating effects of inter-task similarity, task complexity and trainee characteristics are discussed.

Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

International Nuclear Information System (INIS)

Malinowski, Kathleen T.; McAvoy, Thomas J.; George, Rohini; Dieterich, Sonja; D'Souza, Warren D.

2012-01-01

Purpose: To investigate the effect of tumor site, measurement precision, tumor–surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor–surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor–surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3–3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

Energy Technology Data Exchange (ETDEWEB)

Malinowski, Kathleen T. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); McAvoy, Thomas J. [Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); Department of Chemical and Biomolecular Engineering and Institute of Systems Research, University of Maryland, College Park, MD (United States); George, Rohini [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Dieterich, Sonja [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); D' Souza, Warren D., E-mail: wdsou001@umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States)

2012-04-01

Purpose: To investigate the effect of tumor site, measurement precision, tumor-surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor-surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor-surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3-3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

Positive Predictive Value of True Bacteremia according to the Number of Positive Culture Sets in Adult Patients.

Science.gov (United States)

Kitaura, Tsuyoshi; Chikumi, Hiroki; Fujiwara, Hiromitsu; Okada, Kensaku; Hayabuchi, Tatsuya; Nakamoto, Masaki; Takata, Miyako; Yamasaki, Akira; Igishi, Tadashi; Burioka, Naoto; Shimizu, Eiji

2014-12-01

Performing multiple blood culture sets simultaneously is a standard blood culture methodology, although it is often difficult to distinguish true bacteremia from contamination when only one of several blood culture sets is positive. This study clarified the relationship between the number of positive blood culture sets and clinical significance in patients with positive blood culture. Patients aged 18 years and over with at least 1 positive blood culture were enrolled. Positive blood culture episodes were categorized from clinical records as true bacteremia, contamination, or unknown clinical significance. The associations among episodes of true bacteremia, isolated bacteria, the number of positive blood culture sets from among the performed sets, and the clinical background of patients were analyzed. Among a total of 407 episodes, 262, 67 and 78 were true bacteremia, contamination and unknown clinical significance, respectively. The positive predictive values (PPVs) of 1 out of 1, 1 out of 2 and 2 out of 2 positive sets in cases of Staphylococcus aureus, were 81.3%, 50% and 100% respectively; those in cases of coagulase-negative Staphylococci were 20.5%, 10.8% and 63.5%, respectively. Almost all cases of Escherichia coli, Pseudomonas aeruginosa, Klebsiella species and Candida species were true bacteremia. The probability of true bacteremia was strongly associated with recent surgery in multivariate analysis (P sets from among the performed sets varies by microorganism. Therefore, PPVs calculated using this method may help physicians distinguish true bacteremia from contamination.

Study on Vibration of Heavy-Precision Robot Cantilever Based on Time-varying Glowworm Swarm Optimization Algorithm

Science.gov (United States)

Luo, T. H.; Liang, S.; Miao, C. B.

2017-12-01

A method of terminal vibration analysis based on Time-varying Glowworm Swarm Optimization algorithm is proposed in order to solve the problem that terminal vibration of the large flexible robot cantilever under heavy load precision.The robot cantilever of the ballastless track is used as the research target and the natural parameters of the flexible cantilever such as the natural frequency, the load impact and the axial deformation is considered. Taking into account the change of the minimum distance between the glowworm individuals, the terminal vibration response and adaptability could meet. According to the Boltzmann selection mechanism, the dynamic parameters in the motion simulation process are determined, while the influence of the natural frequency and the load impact as well as the axial deformation on the terminal vibration is studied. The method is effective and stable, which is of great theoretical basis for the study of vibration control of flexible cantilever terminal.

Actinonin, a naturally occurring antibacterial agent, is a potent deformylase inhibitor.

Science.gov (United States)

Chen, D Z; Patel, D V; Hackbarth, C J; Wang, W; Dreyer, G; Young, D C; Margolis, P S; Wu, C; Ni, Z J; Trias, J; White, R J; Yuan, Z

2000-02-15

Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian cells, thus making it an attractive target for the discovery of novel antibiotics. We have identified actinonin, a naturally occurring antibacterial agent, as a potent PDF inhibitor. The dissociation constant for this compound was 0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from Staphylococcus aureus gave a similar value. Microbiological evaluation revealed that actinonin is a bacteriostatic agent with activity against Gram-positive and fastidious Gram-negative microorganisms. The PDF gene, def, was placed under control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels in the cell by varying the external arabinose concentration. The susceptibility of this strain to actinonin increases with decreased levels of PDF expression, indicating that actinonin inhibits bacterial growth by targeting this enzyme. Actinonin provides an excellent starting point from which to derive a more potent PDF inhibitor that has a broader spectrum of antibacterial activity.

Environmental application of modified natural zeolites

International Nuclear Information System (INIS)

Nikashina, V.A.; Myasoedov, B.F.

1998-01-01

The following techniques were used for the chemical modification of the natural zeolites: (1) treatment of natural zeolites with organic substances. Examples of applications of these sorbents to the decontamination and disinfection of solutions of different composition and surface waters are presented. (2) Treatment of the natural zeolites with a inorganic substances. (2.1) The clinoptilolite-rich tuffs were treated with a hot suspensions of freshly precipitated magnetite. This leads to the preparation of sorbents possessing magnetic properties. The radionuclides and heavy metals recovery from soils and silts was investigated using different soil and ferromagnetic zeolite weights ratios and contact times. Different soils and sorbent of varying capacities were used for these investigations. As example, the recovery 137 Cs and 85 Sr from soils of different nature is presented. (2.2) Treatment of natural zeolites with Fe-containing solutions of Fe-containing natural waters. The filtration of these solutions through clinoptilolite-rich tuffs makes leads to preparation of materials possessing high selectivity to PO 4 3- ions. The properties of these sorbents can be utilized for the PO 4 3+ decontamination of waters (e.g. waste waters) and for the subsequent use of these materials in agriculture as fertilizers.(author)

Robust Stability of Scaled-Four-Channel Teleoperation with Internet Time-Varying Delays

Directory of Open Access Journals (Sweden)

Emma Delgado

2016-04-01

Full Text Available We describe the application of a generic stability framework for a teleoperation system under time-varying delay conditions, as addressed in a previous work, to a scaled-four-channel (γ-4C control scheme. Described is how varying delays are dealt with by means of dynamic encapsulation, giving rise to mu-test conditions for robust stability and offering an appealing frequency technique to deal with the stability robustness of the architecture. We discuss ideal transparency problems and we adapt classical solutions so that controllers are proper, without single or double differentiators, and thus avoid the negative effects of noise. The control scheme was fine-tuned and tested for complete stability to zero of the whole state, while seeking a practical solution to the trade-off between stability and transparency in the Internet-based teleoperation. These ideas were tested on an Internet-based application with two Omni devices at remote laboratory locations via simulations and real remote experiments that achieved robust stability, while performing well in terms of position synchronization and force transparency.

Robust Stability of Scaled-Four-Channel Teleoperation with Internet Time-Varying Delays.

Science.gov (United States)

Delgado, Emma; Barreiro, Antonio; Falcón, Pablo; Díaz-Cacho, Miguel

2016-04-26

We describe the application of a generic stability framework for a teleoperation system under time-varying delay conditions, as addressed in a previous work, to a scaled-four-channel (γ-4C) control scheme. Described is how varying delays are dealt with by means of dynamic encapsulation, giving rise to mu-test conditions for robust stability and offering an appealing frequency technique to deal with the stability robustness of the architecture. We discuss ideal transparency problems and we adapt classical solutions so that controllers are proper, without single or double differentiators, and thus avoid the negative effects of noise. The control scheme was fine-tuned and tested for complete stability to zero of the whole state, while seeking a practical solution to the trade-off between stability and transparency in the Internet-based teleoperation. These ideas were tested on an Internet-based application with two Omni devices at remote laboratory locations via simulations and real remote experiments that achieved robust stability, while performing well in terms of position synchronization and force transparency.

A Survey of Wireless Indoor Positioning Technology for Fire Emergency Routing

International Nuclear Information System (INIS)

Niu, Lei

2014-01-01

Fire emergency response needs positioning solutions to assist evacuation and rescue operations. Therefore, we have to carefully review the candidates for this purpose. These indoor positioning technologies show different levels of applicability in fire emergency response. According to the varying demands of emergency response, flexible localization solutions should be provided. Thus, we guide a first step to implement this concept in three pre-defined emergency scenes. At last, we conclude several key features for indoor positioning solutions for emergency routing and three future research topics

Quality Assurance After a Natural Disaster: Lessons from Hurricane Sandy.

Science.gov (United States)

Dickerson, Collin; Hsu, Yanshen; Mendoza, Sandra; Osman, Iman; Ogilvie, Jennifer; Patel, Kepal; Moreira, Andre L

2018-04-01

Biospecimen quality can vary depending on many pre- and post-collection variables. In this study, we consider a natural disaster as a post-collection variable that may have compromised the quality of frozen tissue specimens. To investigate this possible link, we compared the quality of nucleic acids, the level of antigenicity, and the preservation of histology from frozen specimens collected before and after the power outage caused by Hurricane Sandy. To analyze nucleic acid quality, we extracted both DNA and RNA and performed capillary electrophoresis to compare the quality and concentrations of the nucleic acids. To compare antigenicity, frozen sections were cut and immunostained for thyroid transcription factor 1 (TTF-1), a nuclear transcription protein commonly used as a diagnostic biomarker for multiple cancer types, including thyroid and lung cancers. Positive expression of TTF-1, as noted by homogenous nuclear staining, would demonstrate that the TTF-1 proteins could still bind antibodies and, therefore, that these proteins were not significantly degraded. Furthermore, representative frozen sections stained with hematoxylin and eosin were also assessed qualitatively by a trained pathologist to examine any possible histologic aberrations. Due to the similar quality of the tissue samples collected before and after the storm, Hurricane Sandy had no discernable effect on the quality of frozen specimens, and these specimens exposed to the natural disaster are still valuable research tools.

Performance of an Otto cycle motor with natural gas direct injection; Desempenho de um motor ciclo Otto com injecao direta de gas natural

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Cleiton Rubens Formiga

1997-07-01

A Otto cycle engine with natural gas direct injection, during the inlet stroke, was submitted to runs with full power in a Foucaut dynamometer. The results obtained show a increase in the volumetric efficiency of the engine with natural gas direct injection when compared with natural gas injection applied in the inlet manifold, upstream of the throttle butterfly. In the conversion to natural gas direct injection, the technical characteristics were not changed. A kit for natural gas direct injection, with electronic management was located on the cylinder head of the test engine. Maintaining the pressure constant in the natural gas fuel line, using a reduction valve, the mass of fuel injected into the cylinder was regulated, varying the opening time of the solenoid valve fuel injector. Engine performance data is compared, emphasizing the factors that contribute to this increase in relative volumetric efficiency. Modifications are made to maximize the power of the engine with natural gas direct injection. (author)

Matching Value Propositions with Varied Customer Needs

DEFF Research Database (Denmark)

Heikka, Eija-Liisa; Frandsen, Thomas; Hsuan, Juliana

2018-01-01

Organizations seek to manage varied customer segments using varied value propositions. The ability of a knowledge-intensive business service (KIBS) provider to formulate value propositions into attractive offerings to varied customers becomes a competitive advantage. In this specific business based...... on often highly abstract service offerings, this requires the provider to have a clear overview of its knowledge and resources and how these can be configured to obtain the desired customization of services. Hence, the purpose of this paper is to investigate how a KIBS provider can match value propositions...... with varied customer needs utilizing service modularity. To accomplish this purpose, a qualitative multiple case study is organized around 5 projects allowing within-case and cross-case comparisons. Our findings describe how through the configuration of knowledge and resources a sustainable competitive...

Nature tourism and Irish film

OpenAIRE

Brereton, Pat

2006-01-01

This article provides a historical overview and reading of seminal Irish film from the perspective of nature tourism. Within Irish cultural studies, tourism is frequently equated with an overly romantic image of the island, which has been used to sell the country abroad. However, using notions like the tourist gaze and taking on board influential debates around space/place, one can posit a more progressive environmental vision of nature and landscape in our readings of film.

New Methods for Assessing the Fascinating Nature of Nature Experiences

Science.gov (United States)

Joye, Yannick; Pals, Roos; Steg, Linda; Evans, Ben Lewis

2013-01-01

In recent years, numerous environmental psychology studies have demonstrated that contact with nature as opposed to urban settings can improve an individual’s mood, can lead to increased levels of vitality, and can offer an opportunity to recover from stress. According to Attention Restoration Theory (ART) the restorative potential of natural environments is situated in the fact that nature can replenish depleted attentional resources. This replenishment takes place, in part, because nature is deemed to be a source of fascination, with fascination being described as having an “attentional”, an “affective” and an “effort” dimension. However, the claim that fascination with nature involves these three dimensions is to a large extent based on intuition or derived from introspection-based measurement methods, such as self-reports. In three studies, we aimed to more objectively assess whether these three dimensions indeed applied to experiences related to natural environments, before any (attentional) depletion has taken place. The instruments that were used were: (a) the affect misattribution procedure (Study 1), (b) the dot probe paradigm (Study 2) and (c) a cognitively effortful task (Study 3). These instrument were respectively aimed at verifying the affective, attentional and effort dimension of fascination. Overall, the results provide objective evidence for the claims made within the ART framework, that natural as opposed to urban settings are affectively positive (cfr., affective dimension) and that people have an attentional bias to natural (rather than urban) environments (cfr., attentional dimension). The results regarding the effort dimension are less straightforward, and suggest that this dimension only becomes important in sufficiently difficult cognitive tasks. PMID:23922645

Effect of softening precipitate composition and surface characteristics on natural organic matter adsorption.

Science.gov (United States)

Russell, Caroline G; Lawler, Desmond F; Speitel, Gerald E; Katz, Lynn E

2009-10-15

Natural organic matter (NOM) removal during water softening is thought to occur through adsorption onto or coprecipitation with calcium and magnesium solids. However, details of precipitate composition and surface chemistry and subsequent interactions with NOM are relatively unknown. In this study, zeta potentiometry analyses of precipitates formed from inorganic solutions under varying conditions (e.g., Ca-only, Mg-only, Ca + Mg, increasing lime or NaOH dose) indicated that both CaCO3 and Mg(OH)2 were positively charged at higher lime (Ca(OH)2) and NaOH doses (associated with pH values above 11.5), potentially yielding a greater affinity for adsorbing negatively charged organic molecules. Environmental scanning electron microscopy (ESEM) images of CaCO3 solids illustrated the rhombohedral shape characteristic of calcite. In the presence of increasing concentrations of magnesium, the CaCO3 rhombs shifted to more elongated crystals. The CaCO3 solids also exhibited increasingly positive surface charge from Mg incorporation into the crystal lattice, potentially creating more favorable conditions for adsorption of organic matter. NOM adsorption experiments using humic substances extracted from Lake Austin and Missouri River water elucidated the role of surface charge and surface area on adsorption.

Discovery of natural gain amplification in the 10-micrometer carbon dioxide laser bands on Mars - A natural laser

Science.gov (United States)

Mumma, M. J.; Buhl, D.; Chin, G.; Deming, D.; Espenak, F.; Kostiuk, T.; Zipoy, D.

1981-01-01

Fully resolved intensity profiles of various lines in the carbon dioxide band at 10.4 micrometers have been measured on Mars with an infrared heterodyne spectrometer. Analysis of the line shapes shows that the Mars atmosphere exhibits positive gain in these lines. The detection of natural optical gain amplification enables identification of these lines as a definite natural laser.

Experimental investigations on scaled models for the SNR-2 decay heat removal by natural convection

International Nuclear Information System (INIS)

Hoffmann, H.; Weinberg, D.; Tschoeke, H.; Frey, H.H.; Pertmer, G.

1986-01-01

Scaled water models are used to prove the mode of function of the decay heat removal by natural convection for the SNR-2. The 2D and 3D models were designed to reach the characteristic numbers (Richardson, Peclet) of the reactor. In the experiments on 2D models the position of the immersed cooler (IC) and the power were varied. Temperature fields and velocities were measured. The IC installed as a separate component in the hot plenum resulted in a very complex flow behavior and low temperatures. Integrating the IC in the IHX showed a very simple circulating flow and high temperatures within the hot plenum. With increasing power only slightly rising temperature differences within the core and IC were detected. Recalculations using the COMMIX 1B code gave qualitatively satisfying results. (author)

The cases of observance and violation of politeness maxims by communicants in the ego-state of natural Child

Directory of Open Access Journals (Sweden)

Гульнара Фанзиловна Гизатова

2014-12-01

Full Text Available Nowadays, the study of human communication is of great importance in linguistics and psychology. In order to achieve smooth and conflict-free interaction it is necessary not only to respect the rules of politeness, but also to take into account the position of the speaker and the addressee. This explains the need to study many psychological factors in communication. This paper studies the ego-state of Natural Child in speech communication. Investigating the behavior of communicants in the ego-state of Natural Child, we rely on the theory of transactional analysis (E. Bern 1961 . According to this theory, the behavior of the speaker and the addressee in the ego-states of Natural Child varies from curious, inspiring, dreamy, and natural to the selfish, spiteful, shameless and impatient. The material for investigation is the dialogs from British and American fiction of XIX-XXI centuries. The dialogs contain the speaker and addressee’s replicas, meeting the essential requirements of the Principle of Politeness (G. Leech 1983 and the theory of transactional analysis. In our work we have applied hypothetical-deductive method, and methods of definitional and contextual analysis. The anylisis of our material demonstrates that communicants in the ego-state of Natural Child observe the maxims of generosity, tact and agreement, and violate the maxims of approbation, modesty and tact. Thus, the implementation of politeness maxims by communicants in ego-state of Natural Child depends entirely on their behavior.

Standardization of sequential separation of naturally occurring radionuclides in drinking water

International Nuclear Information System (INIS)

Nair, Madhu G.; Rao, D.D.; Sathyapriya, R.S.; Sarkar, P.K.

2012-01-01

Human are constantly exposed to radiation originating from natural or manmade sources. The main contribution for internal dose is due to radionuclides from uranium and thorium series in drinking water. The distribution of these elements varies depending on the geological and physiological characteristics of the aquifer. With increased concern for radiological safety of public, it is necessary to evaluate the naturally occurring radionuclides in the drinking water

[Mes differ by positioning: empirical testing of decentralized dynamics of the self].

Science.gov (United States)

Mizokami, Shinichi

2013-10-01

The present study empirically tested the conceptualization of the decentralized dynamics of the self proposed by Hermans & Kempen (1993), which they developed theoretically and from clinical cases, not from large samples of empirical data. They posited that worldviews and images of the self could vary by positioning even in the same individual, and denied that the ego was an omniscient entity that knew and controlled all aspects of the self (centralized ego). Study 1 tested their conceptualization empirically with 47 university students in an experimental group and 17 as a control group. The results showed that the scores on the Rosenberg's self-esteem scale and images of the Mes in the experimental group significantly varied by positioning, but those in the control group did not. Similar results were found in Study 2 with a sample of 120 university students. These results empirically supported the conceptualization of the decentralized dynamics of the self.

Positive dynamical systems in discrete time theory, models, and applications

CERN Document Server

Krause, Ulrich

2015-01-01

This book provides a systematic, rigorous and self-contained treatment of positive dynamical systems. A dynamical system is positive when all relevant variables of a systemare nonnegative in a natural way. This is in biology, demography or economics, where the levels of populations or prices of goods are positive. The principle also finds application in electrical engineering, physics and computer sciences.

Kullback-Leibler information in resolving natural resource conflicts when definitive data exist

Science.gov (United States)

Anderson, D.R.; Burnham, K.P.; White, Gary C.

2001-01-01

Conflicts often arise in the management of natural resources. Often they result from differing perceptions, varying interpretations of the law, and self-interests among stakeholder groups (for example, the values and perceptions about spotted owls and forest management differ markedly among environmental groups, government regulatory agencies, and timber industries). We extend the conceptual approach to conflict resolution of Anderson et al. (1999) by using information-theoretic methods to provide quantitative evidence for differing stakeholder positions. Importantly, we assume that relevant empirical data exist that are central to the potential resolution of the conflict. We present a hypothetical example involving an experiment to assess potential effects of a chemical on monthly survival probabilities of the hen clam (Spisula solidissima). The conflict centers on 3 stakeholder positions: 1) no effect, 2) an acute effect, and 3) an acute and chronic effect of the chemical treatment. Such data were given to 18 analytical teams to make independent analyses and provide the relative evidence for each of 3 stakeholder positions in the conflict. The empirical evidence strongly supports only one of the 3 positions in the conflict: the application of the chemical causes acute and chronic effects on monthly survival, following treatment. Formal inference from all the stakeholder positions is provided for the 2 key parameters underlying the hen clam controversy. The estimates of these parameters were essentially unbiased (the relative bias for the control and treatment group's survival probability was -0.857% and 1.400%, respectively) and precise (coefficients of variation were 0.576% and 2.761%, respectively). The advantages of making formal inference from all the models, rather than drawing conclusions from only the estimated best model, is illustrated. Finally, we contrast information-theoretic and Bayesian approaches in terms of how positions in the controversy enter

Design of 2D time-varying vector fields.

Science.gov (United States)

Chen, Guoning; Kwatra, Vivek; Wei, Li-Yi; Hansen, Charles D; Zhang, Eugene

2012-10-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects.

Natural Origin Materials for Osteochondral Tissue Engineering.

Science.gov (United States)

Bonani, Walter; Singhatanadgige, Weerasak; Pornanong, Aramwit; Motta, Antonella

2018-01-01

Materials selection is a critical aspect for the production of scaffolds for osteochondral tissue engineering. Synthetic materials are the result of man-made operations and have been investigated for a variety of tissue engineering applications. Instead, the products of physiological processes and the metabolic activity of living organisms are identified as natural materials. Over the recent decades, a number of natural materials, namely, biopolymers and bioceramics, have been proposed as the main constituent of osteochondral scaffolds, but also as cell carriers and signaling molecules. Overall, natural materials have been investigated both in the bone and in the cartilage compartment, sometimes alone, but often in combination with other biopolymers or synthetic materials. Biopolymers and bioceramics possess unique advantages over their synthetic counterparts due similarity with natural extracellular matrix, the presence of cell recognition sites and tunable chemistry. However, the characteristics of natural origin materials can vary considerably depending on the specific source and extraction process. A deeper understanding of the relationship between material variability and biological activity and the definition of standardized manufacturing procedures will be crucial for the future of natural materials in tissue engineering.

A Writing Intensive Course in "Natural Disasters: Geoethics and the Layman"

Science.gov (United States)

Fryer, P.

2011-12-01

One course with a contemporary ethics focus is a graduation requirement under the University of Hawaii at Manoa's General Education rules. The goal of the University of Hawaii General Education Committee is to encourage faculty to design ethics-focus courses for each field of undergraduate concentration. Undergraduate students are also required to take 5 writing intensive courses. It is permitted to combine the ethics and writing intensive foci in a given course, as long as one third of the course is devoted to each focus. The course I designed uses current disasters as the subject matter, thus course content varies from year to year. The prerequisite for enrollment is one introductory course in geoscience, to ensure students are familiar with basic geologic processes. I bring in geo-professionals, active in the fields we study, to discuss with students the realities of dealing with civil authorities, elected officials, the media, and the public during a natural disaster. This is one of the aspects of the course the students most enjoy. Such a course could be designed for any locality. Learning outcomes by which the students' work is assessed are as follows. The best student: (1) clearly identifies the inherent ethical choices and implications involved in the professional geoscientist's role during contemporary natural hazard situations; (2) gives evidence of understanding the effects of perspective, context, personal views as pertains to natural hazards; (3) specifies the decision-makers and stakeholders involved in hazard situations; (4) integrates clear descriptions of relevant ethical ambiguities/dilemmas into the overall analysis of a given hazard situation; (5) draws upon frameworks, principles of ethics to develop pertinent arguments and/or positions; (6) develops and presents alternate arguments/positions; (7) discusses and/or debates ethical issues with sensitivity to others' perspectives and the context, while also defending own position with logic and

ASSESSING THE NATURAL REGENERATION OF THREE SPECIES CONIFER NATURAL RANGE IN THE WESTERN HIGHLANDS OF GUATEMALA

Directory of Open Access Journals (Sweden)

Sergio Miguel Godínez

2016-06-01

Full Text Available Coniferous forests of the western highlands of Guatemala have been disturbed by human intervention and natural phenomena, which has allowed the occurrence of the phenomenon of natural regeneration. In this scenario the density of natural regeneration of conifers three species evaluated (Pinus oocarpa Schiede, P. pseudostrobus Lindl. and P. tecunumanii Eguiluz & Perry in 60 sites distributed in space and clear edge. The variables evaluated were the source of disturbance that caused its establishment, density variation of the source of seed and distance estimation range scattering adequate regeneration, using sampling units of 25 m2 for natural regeneration and 500 m2 seed source trees. Disturbance sources identified were logging 55%, 24% forest fires, pests 8%, agriculture, avalanche 5% each and hurricane 3%. The variation of the density of natural regeneration on the seed source, corresponds to the inverted J models for edges, and to clear variable subpopulations. Dispersal distances of natural regeneration was established for P.oocarpa 65 m in edges, and 160 m in the clears; P. pseudostrobus 75 m in edges, and 175 m in the clears; and P. tecunumanii was 70 m in edges, and 170 m in the clears. Dispersal distances with acceptable densities according National Forestry Institute-Regional Forestry Programme for Central American, for the three species vary from 65-175 m

Investigation of natural radioactivity level of the waters in Guangxi Zhuangzu Autonomous Region

International Nuclear Information System (INIS)

Yang Mingshen; Ming Chuanbao; Dai Guozhi; Liang Runping; Chen Xiuyu; Yang Gang; Jin Mei

1993-01-01

This paper reports the investigation results of natural radioactivity level in river, lake reservoir, spring, well and tap water in Guangxi Zhuangzu Autonomous Region. There were totally 194 samples collected from 143 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

Evidence for subwavelength imaging with positive refraction

OpenAIRE

Ma, Yun Gui; Sahebdivan, Sahar; Ong, C. K.; Tyc, Tomas; Leonhardt, Ulf

2011-01-01

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction. Publisher PDF Peer reviewed

Finding Positive Feedback Loops in Environmental Models: A Mathematical Investigation

Science.gov (United States)

Sheikholeslami, R.; Razavi, S.

2016-12-01

Dynamics of most earth and environmental systems are generally governed by interactions between several hydrological (e.g., soil moisture and precipitation), geological (e.g., and erosion), geochemical (e.g., nutrient loading), and atmospheric (e.g., temperature) processes which operate on a range of spatio-temporal scales. These interactions create numerous feedback mechanisms with complex behaviours, and their understanding and representation can vary depending on the scale in space and/or time at which the system is analyzed. One of the most crucial characteristics of such complex systems is the existence of positive feedback loops. The presence of positive feedbacks may increase complexity, accelerate change, or trigger multiple stable states in the underlying dynamical system. Furthermore, because of the inherent non-linearity, it is often very difficult to obtain a general idea of their complex dynamics. Feedback loops in environmental systems have been well recognized and qualitatively discussed. With a quantitative/mathematical view, in this presentation, we address the question of how the positive feedback loops can be identified/implemented in environmental models. We investigate the nature of different feedback mechanisms and dynamics of simple example case studies that underlie fundamental processes such as vegetation, precipitation and soil moisture. To do this, we apply the concept of "interaction graph" from mathematics which is built from the Jacobian matrix of the dynamical system. The Jacobian matrix contains information on how variations of one state variable depends on variations of other variables, and thus can be used to understand the dynamical possibilities of feedback mechanisms in the underlying system. Moreover, this study highlights that there are some situations where the existence of positive feedback loops can cause multiple stable states, and thereby regime shifts in environmental systems. Systems with multiple stable states are

Serial position effects are sensitive predictors of conversion from MCI to Alzheimer's disease dementia.

Science.gov (United States)

Egli, Simone C; Beck, Irene R; Berres, Manfred; Foldi, Nancy S; Monsch, Andreas U; Sollberger, Marc

2014-10-01

It is unclear whether the predictive strength of established cognitive variables for progression to Alzheimer's disease (AD) dementia from mild cognitive impairment (MCI) varies depending on time to conversion. We investigated which cognitive variables were best predictors, and which of these variables remained predictive for patients with longer times to conversion. Seventy-five participants with MCI were assessed on measures of learning, memory, language, and executive function. Relative predictive strengths of these measures were analyzed using Cox regression models. Measures of word-list position-namely, serial position scores-together with Short Delay Free Recall of word-list learning best predicted conversion to AD dementia. However, only serial position scores predicted those participants with longer time to conversion. Results emphasize that the predictive strength of cognitive variables varies depending on time to conversion to dementia. Moreover, finer measures of learning captured by serial position scores were the most sensitive predictors of AD dementia. Copyright © 2014 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

The Power of Montessori's Positive Psychology in an Expanding Universe.

Science.gov (United States)

Haines, Annette

1999-01-01

Relates Montessori theory of development with the concept of connection to the universe and natural world, noting Montessori education's role in nurturing reestablished connection with the natural world. Describes events leading to a fulfilled life as part of psychological normalization, noting the importance of identifying positive tendencies of…

Fast Fingerprint Database Maintenance for Indoor Positioning Based on UGV SLAM

Directory of Open Access Journals (Sweden)

Jian Tang

2015-03-01

Full Text Available Indoor positioning technology has become more and more important in the last two decades. Utilizing Received Signal Strength Indicator (RSSI fingerprints of Signals of OPportunity (SOP is a promising alternative navigation solution. However, as the RSSIs vary during operation due to their physical nature and are easily affected by the environmental change, one challenge of the indoor fingerprinting method is maintaining the RSSI fingerprint database in a timely and effective manner. In this paper, a solution for rapidly updating the fingerprint database is presented, based on a self-developed Unmanned Ground Vehicles (UGV platform NAVIS. Several SOP sensors were installed on NAVIS for collecting indoor fingerprint information, including a digital compass collecting magnetic field intensity, a light sensor collecting light intensity, and a smartphone which collects the access point number and RSSIs of the pre-installed WiFi network. The NAVIS platform generates a map of the indoor environment and collects the SOPs during processing of the mapping, and then the SOP fingerprint database is interpolated and updated in real time. Field tests were carried out to evaluate the effectiveness and efficiency of the proposed method. The results showed that the fingerprint databases can be quickly created and updated with a higher sampling frequency (5Hz and denser reference points compared with traditional methods, and the indoor map can be generated without prior information. Moreover, environmental changes could also be detected quickly for fingerprint indoor positioning.

Variability salt stress response analysis of Tunisian natural ...

African Journals Online (AJOL)

We evaluated the responses to salt stress of 106 Medicago truncatula lines from 11 Tunisian natural populations collected from areas that varied in soil composition, salinity and water availability. Five references lines were also included in this study. Plants were cultivated in two treatments (0 and 50 mM of NaCl) during a ...

Economic assessment of electric energy storage for load shifting in positive energy building

DEFF Research Database (Denmark)

Dumont, Olivier; Do Carmo, Carolina Madeira Ramos; Georges, Emeline

2017-01-01

Net zero energy buildings and positive energy buildings are gaining more and more interest. This paper evaluates the impact of the integration of a battery in a positive energy building used to increase its self-consumption of electricity. Parametric studies are carried out by varying the buildin...... and a 3.7 kWh battery. Finally, simple correlations (based on the feed-in tariff, the annual electrical consumption and production) to predict the optimal size of battery and the lowest payback period are proposed.......Net zero energy buildings and positive energy buildings are gaining more and more interest. This paper evaluates the impact of the integration of a battery in a positive energy building used to increase its self-consumption of electricity. Parametric studies are carried out by varying the building...... envelope characteristics, the power supply system, the climate, the lighting and appliances profiles, the roof tilt angle, the battery size and the electricity tariffs, leading to 3200 cases. The analysis is performed on an annual basis in terms of self-consumption and self-production rate and payback...

Design of 2D Time-Varying Vector Fields

KAUST Repository

Chen, Guoning

2012-10-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects. © 1995-2012 IEEE.

Design of 2D Time-Varying Vector Fields

KAUST Repository

Chen, Guoning; Kwatra, Vivek; Wei, Li-Yi; Hansen, Charles D.; Zhang, Eugene

2012-01-01

Design of time-varying vector fields, i.e., vector fields that can change over time, has a wide variety of important applications in computer graphics. Existing vector field design techniques do not address time-varying vector fields. In this paper, we present a framework for the design of time-varying vector fields, both for planar domains as well as manifold surfaces. Our system supports the creation and modification of various time-varying vector fields with desired spatial and temporal characteristics through several design metaphors, including streamlines, pathlines, singularity paths, and bifurcations. These design metaphors are integrated into an element-based design to generate the time-varying vector fields via a sequence of basis field summations or spatial constrained optimizations at the sampled times. The key-frame design and field deformation are also introduced to support other user design scenarios. Accordingly, a spatial-temporal constrained optimization and the time-varying transformation are employed to generate the desired fields for these two design scenarios, respectively. We apply the time-varying vector fields generated using our design system to a number of important computer graphics applications that require controllable dynamic effects, such as evolving surface appearance, dynamic scene design, steerable crowd movement, and painterly animation. Many of these are difficult or impossible to achieve via prior simulation-based methods. In these applications, the time-varying vector fields have been applied as either orientation fields or advection fields to control the instantaneous appearance or evolving trajectories of the dynamic effects. © 1995-2012 IEEE.

Quantum Capacity under Adversarial Quantum Noise: Arbitrarily Varying Quantum Channels

Science.gov (United States)

Ahlswede, Rudolf; Bjelaković, Igor; Boche, Holger; Nötzel, Janis

2013-01-01

We investigate entanglement transmission over an unknown channel in the presence of a third party (called the adversary), which is enabled to choose the channel from a given set of memoryless but non-stationary channels without informing the legitimate sender and receiver about the particular choice that he made. This channel model is called an arbitrarily varying quantum channel (AVQC). We derive a quantum version of Ahlswede's dichotomy for classical arbitrarily varying channels. This includes a regularized formula for the common randomness-assisted capacity for entanglement transmission of an AVQC. Quite surprisingly and in contrast to the classical analog of the problem involving the maximal and average error probability, we find that the capacity for entanglement transmission of an AVQC always equals its strong subspace transmission capacity. These results are accompanied by different notions of symmetrizability (zero-capacity conditions) as well as by conditions for an AVQC to have a capacity described by a single-letter formula. In the final part of the paper the capacity of the erasure-AVQC is computed and some light shed on the connection between AVQCs and zero-error capacities. Additionally, we show by entirely elementary and operational arguments motivated by the theory of AVQCs that the quantum, classical, and entanglement-assisted zero-error capacities of quantum channels are generically zero and are discontinuous at every positivity point.

Exploring the relationship between nature sounds, connectedness to nature, mood and willingness to buy sustainable food: A retail field experiment.

Science.gov (United States)

Spendrup, Sara; Hunter, Erik; Isgren, Ellinor

2016-05-01

Nature sounds are increasingly used by some food retailers to enhance in-store ambiance and potentially even influence sustainable food choices. An in-store, 2 × 3 between-subject full factorial experiment conducted on 627 customers over 12 days tested whether nature sound directly and indirectly influenced willingness to buy (WTB) sustainable foods. The results show that nature sounds positively and directly influence WTB organic foods in groups of customers (men) that have relatively low initial intentions to buy. Indirectly, we did not find support for the effect of nature sound on influencing mood or connectedness to nature (CtN). However, we show that information on the product's sustainability characteristics moderates the relationship between CtN and WTB in certain groups. Namely, when CtN is high, sustainability information positively moderated WTB both organic and climate friendly foods in men. Conversely, when CtN was low, men expressed lower WTB organic and climate friendly foods than identical, albeit conventionally labelled products. Consequently, our study concludes that nature sounds might be an effective, yet subtle in-store tool to use on groups of consumers who might otherwise respond negatively to more overt forms of sustainable food information. Copyright © 2016 Elsevier Ltd. All rights reserved.

Time-varying Crash Risk

DEFF Research Database (Denmark)

Christoffersen, Peter; Feunoua, Bruno; Jeon, Yoontae

We estimate a continuous-time model with stochastic volatility and dynamic crash probability for the S&P 500 index and find that market illiquidity dominates other factors in explaining the stock market crash risk. While the crash probability is time-varying, its dynamic depends only weakly on re...

Local People, Nature Conservation, and Tourism in Northeastern Finland

Directory of Open Access Journals (Sweden)

Anne Törn

2008-06-01

Full Text Available The opinions and perceptions of local communities are central issues in the sustainable management of conservation areas. During 2002 and 2003, we studied the opinions of local people about nature conservation and the development of tourism to investigate whether these opinions were influenced by socioeconomic and demographic factors. Data were collected via a survey of local residents in six areas with different histories of land use, land ownership, conservation, and tourism development. We classified respondents by cluster analysis into three different groups according to their opinions about nature conservation and tourism development: (1 sympathetic to nature conservation, but quite neutral to tourism development (57.7%; (2 critical of nature conservation, but quite neutral to tourism development (30.5%; and (3 quite neutral to nature conservation, but critical of tourism development (11.8%. The most important factors for classification were residential area, age, level of education, primary occupation, indigenousness, frequency of contact with tourists through work, and effects of nature conservation on household economy. On the other hand, gender, level of income, land ownership, land donation for conservation, and income from tourism did not affect opinions concerning nature conservation and tourism development. Almost equal proportions of residents living in close proximity to conservation areas in Kuusamo had positive and negative opinions about nature conservation. Residents living in close proximity to conservation areas regarded conservation as something that might reduce employment and incomes. On the other hand, a greater proportion of residents living near tourist resorts and farther from conservation areas had positive opinions about and perceptions of nature conservation and tourism development. Based on the proportional division of all respondents into the three groups, there may be a coexistent relationship between nature

Positional Differences in Elite Basketball: Selecting Appropriate Training - Load Measures.

Science.gov (United States)

Svilar, Luka; Castellano, Julen; Jukic, Igor; Casamichana, David

2018-01-18

The purpose of this paper was to study the structure of interrelationships among external training load measures and how these vary among different positions in elite basketball. Eight external variables of jumping (JUMP), acceleration (ACC), deceleration (DEC) and change of direction (COD), and two internal load variables (RPE and sRPE) were collected from 13 professional players with 300 session records. Three playing positions were considered: guards (n=4), forwards (n=4) and centers (n=5). High and total external variables (hJUMP and tJUMP, hACC and tACC, hDEC and tDEC, hCOD and tCOD) were used for the principal component analysis. Extraction criteria were set at the eigenvalue of greater than one. Varimax rotation mode was used to extract multiple principal components. The analysis showed that all positions had two or three principal components (explaining almost all of the variance), but the configuration of each factor was different: tACC, tDEC, tCOD and hJUMP for centers, hACC, tACC, tCOD and hJUMP for guards, and tACC, hDEC, tDEC, hCOD, and tCOD for forwards are specifically demanded in training sessions and, therefore, these variables must be prioritized in load monitoring. Furthermore, for all playing positions, RPE and sRPE have high correlation with the total amount of ACC, DEC and COD. This would suggest that, although players perform the same training tasks, the demands of each position can vary. A particular combination of external load measures is required to describe training load of each playing position, especially to better understand internal responses among players.

Review of Modelling Approaches for Developing Virtual Natural Lighting Solutions

NARCIS (Netherlands)

Mangkuto, R.A.; Ochoa Morales, C.E.; Aries, M.B.C.; Loenen, van E.J.; Hensen, J.L.M.

2011-01-01

Several studies have shown that natural light is preferred over electrical lighting in built environments. It has positive effects on user satisfaction, health, and energy saving. However, natural light is limited by time and space. A possible solution is to apply the new concept of virtual natural

15N NMR spectroscopic investigation of nitrous and nitric acids in sulfuric acid solutions of varying acidities

International Nuclear Information System (INIS)

Prakash, G.K.S.; Heiliger, L.; Olah, G.A.

1990-01-01

Both nitrous and nitric acids were studied in sulfuric acid solutions of varying acid strengths by 15 N NMR spectroscopy. The study gives new insights into the nature of intermediates present at different acid strengths. Furthermore, we have also discovered a novel redox reaction between NO 2 + and NO + ions involving the intermediacy of their respective acids. A mechanism is proposed to explain the observed results. 13 refs., 2 figs., 1 tab

Detection of dynamically varying interaural time differences

DEFF Research Database (Denmark)

Kohlrausch, Armin; Le Goff, Nicolas; Breebaart, Jeroen

2010-01-01

of fringes surrounding the probe is equal to the addition of the effects of the individual fringes. In this contribution, we present behavioral data for the same experimental condition, called dynamically varying ITD detection, but for a wider range of probe and fringe durations. Probe durations varied...

A hepatitis C virus infection model with time-varying drug effectiveness: solution and analysis.

Directory of Open Access Journals (Sweden)

Jessica M Conway

2014-08-01

Full Text Available Simple models of therapy for viral diseases such as hepatitis C virus (HCV or human immunodeficiency virus assume that, once therapy is started, the drug has a constant effectiveness. More realistic models have assumed either that the drug effectiveness depends on the drug concentration or that the effectiveness varies over time. Here a previously introduced varying-effectiveness (VE model is studied mathematically in the context of HCV infection. We show that while the model is linear, it has no closed-form solution due to the time-varying nature of the effectiveness. We then show that the model can be transformed into a Bessel equation and derive an analytic solution in terms of modified Bessel functions, which are defined as infinite series, with time-varying arguments. Fitting the solution to data from HCV infected patients under therapy has yielded values for the parameters in the model. We show that for biologically realistic parameters, the predicted viral decay on therapy is generally biphasic and resembles that predicted by constant-effectiveness (CE models. We introduce a general method for determining the time at which the transition between decay phases occurs based on calculating the point of maximum curvature of the viral decay curve. For the parameter regimes of interest, we also find approximate solutions for the VE model and establish the asymptotic behavior of the system. We show that the rate of second phase decay is determined by the death rate of infected cells multiplied by the maximum effectiveness of therapy, whereas the rate of first phase decline depends on multiple parameters including the rate of increase of drug effectiveness with time.

Estimating varying coefficients for partial differential equation models.

Science.gov (United States)

Zhang, Xinyu; Cao, Jiguo; Carroll, Raymond J

2017-09-01

Partial differential equations (PDEs) are used to model complex dynamical systems in multiple dimensions, and their parameters often have important scientific interpretations. In some applications, PDE parameters are not constant but can change depending on the values of covariates, a feature that we call varying coefficients. We propose a parameter cascading method to estimate varying coefficients in PDE models from noisy data. Our estimates of the varying coefficients are shown to be consistent and asymptotically normally distributed. The performance of our method is evaluated by a simulation study and by an empirical study estimating three varying coefficients in a PDE model arising from LIDAR data. © 2017, The International Biometric Society.

Curious Case of Positive Current Collectors: Corrosion and Passivation at High Temperature.

Science.gov (United States)

Sayed, Farheen N; Rodrigues, Marco-Tulio F; Kalaga, Kaushik; Gullapalli, Hemtej; Ajayan, P M

2017-12-20

In the evaluation of compatibility of different components of cell for high-energy and extreme-conditions applications, the highly focused are positive and negative electrodes and their interaction with electrolyte. However, for high-temperature application, the other components are also of significant influence and contribute toward the total health of battery. In present study, we have investigated the behavior of aluminum, the most common current collector for positive electrode materials for its electrochemical and temperature stability. For electrochemical stability, different electrolytes, organic and room temperature ionic liquids with varying Li salts (LiTFSI, LiFSI), are investigated. The combination of electrochemical and spectroscopic investigations reflects the varying mechanism of passivation at room and high temperature, as different compositions of decomposed complexes are found at the surface of metals.

EIA screening and nature protection in Denmark.

Science.gov (United States)

Christensen, Per; Kørnøv, Lone

2011-04-01

The number of environmental impact assessment (EIA) screenings in Denmark has increased dramatically since 2000. This is a consequence of increased pig production as well as the concentration of production on larger farms. In the same period, EIA rules have developed primarily due to an increased focus on the protection of groundwater and Natura 2000 sites. In particular, the implementation of Natura 2000 in Danish legislation has increased the demands on many farms. In its rulings on appealed cases, the Nature Protection Board of Appeal has strengthened its demands, and this is mirrored in screening practices. In this paper, the demands formulated in the guidelines of local authorities were analysed in order to investigate how the protection of groundwater, coastal waters, lakes and Natura 2000 sites develops through EIA screening. It is concluded that the level of protection has improved, and that the main cause for this is not EIA regulations as such, but the positive role which the implementation of the Natura 2000 objectives has played in this development. However, it was also found that the formulation of demands varies greatly between the counties, thus often resulting in ambiguity and leaving room for quite different practices in different counties. Copyright © 2010 Elsevier Ltd. All rights reserved.

ABOUT DISTRIBUTION OF NATURAL RENTS IN MODERN RUSSIA

Directory of Open Access Journals (Sweden)

G.B. Morozov

2008-12-01

Full Text Available Authors analyses available position of more full distribution of natural rents from obtaining business to State for decision many socio-economic problem in scientific and journalistic literature. With position of civil law they reveal fact that present-day appropriation of State minerals which become property of extracting enterprises show the legal nonsense. This fact is contradict current legislation. Instead of function point of view about forms of rent withdrawal from income obtaining enterprises authoress thinking that the most lawful and fair way of receipt natural rent by State like owner of minerals is contractor’s agreement on extraction minerals.

Practical Results of Forecasting for the Natural Gas Market

OpenAIRE

Potocnik, Primoz; Govekar, Edvard

2010-01-01

Natural gas consumption forecasting is required to balance the supply and consumption of natural gas. Companies and natural gas distributors are motivated to forecast their consumption by the economic incentive model that dictates the cash flow rules corresponding to the forecasting accuracy. The rules are quite challenging but enable the company to gain positive cash flow by forecasting accurately their short-term natural gas consumption. In this chapter, some practical forecasting results f...

Overlapping Neural Correlates of Reading Emotionally Positive and Negative Adjectives

OpenAIRE

Demirakca, Traute; Herbert, Cornelia; Kissler, Johanna; Ruf, Matthias; Wokrina, Tim; Ende, Gabriele

2009-01-01

Comparison of positive and negative naturally read adjectives to neutral adjectives yielded an overlapping higher BOLD response in the occipital and the orbitofrontal cortex (gyrus rectus). Superior medial frontal gyrus and posterior cingulate gyrus showed higher BOLD response to negative adjectives and inferior frontal gyrus to positive adjectives. The overlap of activated regions and lack of pronounced distinct regions supports the assumption that the processing of negative and positive wor...

Inflation and late-time acceleration in braneworld cosmological models with varying brane tension

International Nuclear Information System (INIS)

Wong, K.C.; Cheng, K.S.; Harko, T.

2010-01-01

Braneworld models with variable brane tension λ introduce a new degree of freedom that allows for evolving gravitational and cosmological constants, the latter being a natural candidate for dark energy. We consider a thermodynamic interpretation of the varying brane tension models, by showing that the field equations with variable λ can be interpreted as describing matter creation in a cosmological framework. The particle creation rate is determined by the variation rate of the brane tension, as well as by the brane-bulk energy-matter transfer rate. We investigate the effect of a variable brane tension on the cosmological evolution of the Universe, in the framework of a particular model in which the brane tension is an exponentially dependent function of the scale factor. The resulting cosmology shows the presence of an initial inflationary expansion, followed by a decelerating phase, and by a smooth transition towards a late accelerated de Sitter type expansion. The varying brane tension is also responsible for the generation of the matter in the Universe (reheating period). The physical constraints on the model parameters, resulting from the observational cosmological data, are also investigated. (orig.)

Radiosensitizing and cytotoxic properties of DNA targeted phenanthridine-linked nitroheterocycles of varying electron affinities

International Nuclear Information System (INIS)

Cowan, D.S.M.; Rauth, A.M.; Toronto Univ., ON; Matejovic, J.F.; McClelland, R.A.; Wardman, P.

1994-01-01

2-Nitroimidazoles targeted to DNA via intercalation have previously been shown to be as much as 10-100 times more efficient on a molar basis than the untargeted nitroimidazole, misonidazole, in vitro as hypoxic cell selective radiosensitizers and cytotoxins based on extracellular concentrations. In this work the effect of varying the nitroaromatic group has been examined through the preparation of a DNA-targeted 4-nitroimidazole (4-MeNLP-3), a 5-nitroimidazole (5-NLP-3) and a 5-nitrofuran (FEP-2) linked to phenanthridinium ions. With the previously synthesized 2-nitroimidazoles, this provides a series of DNA targeted compounds of varying electron affinity as well as structure at the nitroaromatic position. The present series of compounds was tested for partition coefficient, DNA binding ability, reduction potentials and in vitro radiosensitizing and cytotoxic abilities. The results obtained indicate that targeting such compounds to DNA diminishes the dependency of radiosensitizing and cytotoxic properties on reduction potential and may allow significant uncoupling of toxicity from radiosensitizing ability. (author)

Arsenic species in atmospheric particulate matter as tracer of the air quality of Doñana Natural Park (SW Spain).

Science.gov (United States)

González-Castanedo, Y; Sanchez-Rodas, D; Sánchez de la Campa, A M; Pandolfi, M; Alastuey, A; Cachorro, V E; Querol, X; de la Rosa, J D

2015-01-01

Sampling and chemical analyses, including major compounds and trace elements, of atmospheric particulate matter (PM10 and PM2.5) have been performed during 2006-2007 in a regional background monitoring station located within the Doñana Natural Park (SW of Spain). This region is strategic for air quality and climate change studies, representing a meeting place of the European and African continents, and the Atlantic Ocean and Mediterranean Sea. The present study based on meteorological parameters demonstrated long-range transport and impact of industrial plumes on the Doñana Natural. Inorganic arsenic species (arsenate and arsenite) have been analyzed in particulate matter (PM) to characterize the impact of near Cu-smelter plumes and demonstrated the long-range transport of industrial pollutants. As(V) is the main specie of As and varies between 95% and 98% of total As in PM10 and 96-97% in PM2.5. The As(V)/As(III) ratio measured in emission plumes of a Cu-smelter are similar to the ratio found in the Doñana Natural Park. The application of Positive Matrix Factorization (PMF) to atmospheric particulate matter estimated the contributions and chemical profiles of natural and anthropogenic sources impacting the Natural Park, demonstrating the industrial origin of the As and other toxic elements in the air. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Innovative Gateway for Indoor Positioning

Directory of Open Access Journals (Sweden)

Marias Giannis F

2006-01-01

Full Text Available Enabling the pervasive paradigm requires the incorporation of location information. Retrieving location data has been a field of ongoing research for both the outdoor and indoor wireless systems. The results in the cellular scenario are already mature and location architectures have been standardized. Recent research is ongoing for indoor-positioning mechanisms, resulting in implementations that vary. A platform that enables the deployment of location-based services in heterogeneous indoor and WLAN-based communication systems will address difficulties in cooperating with different positioning systems. For that purpose, we have designed a novel entity, called Gateway WLAN Location Center (GWLC, which hides the heterogeneous functions of the indoor positioning architectures, incorporating a unified framework for retrieving location data of users and objects. The GWLC platform has been designed to meet objectives such as modularity, scalability, as well as portability, and to facilitate open interfaces. In this contribution, we elaborate on the design principles and the functionality of GWLC. We also provide performance results, obtained through real experiments.

Grade six students' understanding of the nature of science

Science.gov (United States)

Cochrane, Donald Brian

The goal of scientific literacy requires that students develop an understanding of the nature of science to assist them in the reasoned acquisition of science concepts and in their future role as citizens in a participatory democracy. The purpose of this study was to investigate and describe the range of positions that grade six students hold with respect to the nature of science and to investigate whether gender or prior science education was related to students' views of the nature of science. Two grade six classes participated in this study. One class was from a school involved in a long-term elementary science curriculum project. The science curriculum at this school involved constructivist epistemology and pedagogy and a realist ontology. The curriculum stressed hands-on, open-ended activities and the development of science process skills. Students were frequently involved in creating and testing explanations for physical phenomena. The second class was from a matched school that had a traditional science program. Results of the study indicated that students hold a wider range of views of the nature of science than previously documented. Student positions ranged from having almost no understanding of the nature of science to those expressing positions regarding the nature of science that were more developed than previous studies had documented. Despite the range of views documented, all subjects held realist views of scientific knowledge. Contrary to the literature, some students were able to evaluate a scientific theory in light of empirical evidence that they had generated. Results also indicated that students from the project school displayed more advanced views of the nature of science than their matched peers. However, not all students benefited equally from their experiences. No gender differences were found with respect to students' understanding of the nature of science.

Fractional-order positive position feedback compensator for active vibration control of a smart composite plate

Science.gov (United States)

Marinangeli, L.; Alijani, F.; HosseinNia, S. Hassan

2018-01-01

In this paper, Active Vibration Control (AVC) of a rectangular carbon fibre composite plate with free edges is presented. The plate is subjected to out-of-plane excitation by a modal vibration exciter and controlled by Macro Fibre Composite (MFC) transducers. Vibration measurements are performed by using a Laser Doppler Vibrometer (LDV) system. A fractional-order Positive Position Feedback (PPF) compensator is proposed, implemented and compared to the standard integer-order PPF. MFC actuator and sensor are positioned on the plate based on maximal modal strain criterion, so as to control the second natural mode of the plate. Both integer and fractional-order PPF allowed for the effective control of the second mode of vibration. However, the newly proposed fractional-order controller is found to be more efficient in achieving the same performance with less actuation voltage. Moreover, it shows promising performance in reducing spillover effect due to uncontrolled modes.

New varying speed of light theories

CERN Document Server

Magueijo, J

2003-01-01

We review recent work on the possibility of a varying speed of light (VSL). We start by discussing the physical meaning of a varying $c$, dispelling the myth that the constancy of $c$ is a matter of logical consistency. We then summarize the main VSL mechanisms proposed so far: hard breaking of Lorentz invariance; bimetric theories (where the speeds of gravity and light are not the same); locally Lorentz invariant VSL theories; theories exhibiting a color dependent speed of light; varying $c$ induced by extra dimensions (e.g. in the brane-world scenario); and field theories where VSL results from vacuum polarization or CPT violation. We show how VSL scenarios may solve the cosmological problems usually tackled by inflation, and also how they may produce a scale-invariant spectrum of Gaussian fluctuations, capable of explaining the WMAP data. We then review the connection between VSL and theories of quantum gravity, showing how ``doubly special'' relativity has emerged as a VSL effective model of quantum space...

The natural history of Perthes' disease

OpenAIRE

Terjesen, Terje; Wiig, Ola; Svenningsen, Svein

2010-01-01

Background The prognosis in Perthes' disease varies considerably according to certain risk factors, but there is no concensus regarding the relative importance of these factors. We assessed the natural history of the disease and defined prognostic factors of value in deciding the proper treatment. Patients and methods During the 5-year period 1996?2000, a nationwide study on Perthes' disease was performed in Norway. 425 patients were registered. The present study involved the 212 children (me...

Is subjective social status a summary of life-course socioeconomic position?

Science.gov (United States)

Ferreira, Wasney de Almeida; Camelo, Lidyane; Viana, Maria Carmen; Giatti, Luana; Barreto, Sandhi Maria

2018-01-01

Very little is known about the association between objective indicators of socioeconomic position in childhood and adolescence and low subjective social status in adult life, after adjusting for adult socioeconomic position. We used baseline data (2008-2010) from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a multicenter cohort study of 15,105 civil servants from six Brazilian states. Subjective social status was measured using the The MacArthur Scale of Subjective Social Status, which represents social hierarchy in the form of a 10-rung ladder with the top rung representing the highest subjective social status. Participants who chose the bottom four rungs in the ladder were assigned to the low subjective social status category. The following socioeconomic position indicators were investigated: childhood (maternal education), adolescence (occupational social class of the household head; participant's occupational social class of first job; nature of occupation of household head; participant's nature of occupation of first job), and adulthood (participant's occupational social class, nature of occupation and education). The associations between low subjective social status and socioeconomic position were determined using multiple logistic regression, after adjusting for sociodemographic factors and socioeconomic position indicators from other stages of life. After adjustments, low socioeconomic position in childhood, adolescence and adulthood remained significantly associated with low subjective social status in adulthood with dose-response gradients. The magnitude of these associations was stronger for intra-individual than for intergenerational socioeconomic positions. Results suggest that subjective social status in adulthood is the result of a complex developmental process of acquiring socioeconomic self-perception, which is intrinsic to subjective social status and includes current and past, individual and family household experiences.

Design of L1 -Adaptive Controller for Single Axis Positioning Table

Directory of Open Access Journals (Sweden)

Amjad Jalil Humaidi

2017-11-01

Full Text Available L1 adaptive controller has proven to provide fast adaptation with guaranteed transients in a large variety of systems. It is commonly used for controlling systems with uncertain time-varying unknown parameters. The effectiveness of L1 adaptive controller for position control of single axis has been examined and compared with Model Reference Adaptive Controller (MRAC. The Linear servo motor is one of the main constituting elements of the x-y table which is mostly used in automation application. It is characterized by time-varying friction and disturbance

Natural enemies drive geographic variation in plant defenses

DEFF Research Database (Denmark)

Zuest, Tobias; Heichinger, Christian; Grossniklaus, Ueli

2012-01-01

Plants defend themselves against attack by natural enemies, and these defenses vary widely across populations. However, whether communities of natural enemies are a sufficiently potent force to maintain polymorphisms in defensive traits is largely unknown. Here, we exploit the genetic resources...... of Arabidopsis thaliana, coupled with 39 years of field data on aphid abundance, to (i) demonstrate that geographic patterns in a polymorphic defense locus (GS-ELONG) are strongly correlated with changes in the relative abundance of two specialist aphids; and (ii) demonstrate differential selection by the two...... aphids on GS-ELONG, using a multigeneration selection experiment. We thereby show a causal link between variation in abundance of the two specialist aphids and the geographic pattern at GS-ELONG, which highlights the potency of natural enemies as selective forces....

The influence of dissolved petroleum hydrocarbon residues on natural phytoplankton biomass

Digital Repository Service at National Institute of Oceanography (India)

Shailaja, M.S.

on phytoplankton biomass varies depending on the nature rather than the quantity of petroleum hydrocarbons present. Culture studies with unialgal Nitzschia sp. in seawater collected from selected stations in the study area as well as in artificial seawater spiked...

Positive and negative meanings are simultaneously ascribed to colorectal cancer: relationship to quality of life and psychosocial adjustment.

Science.gov (United States)

Camacho, Aldo Aguirre; Garland, Sheila N; Martopullo, Celestina; Pelletier, Guy

2014-08-01

Experiencing cancer can give rise to existential concerns causing great distress, and consequently drive individuals to make sense of what cancer may mean to their lives. To date, meaning-based research in the context of cancer has largely focused on one possible outcome of this process, the emergence of positive meanings (e.g. post-traumatic growth). However, negative meanings may also be ascribed to cancer, simultaneously with positive meanings. This study focused on the nature of the co-existence of positive and negative meanings in a sample of individuals diagnosed with colorectal cancer to find out whether negative meaning had an impact on quality of life and psychosocial adjustment above and beyond positive meaning. Participants were given questionnaires measuring meaning-made, quality of life, and psychological distress. Semi structured interviews were conducted with a subgroup from the original sample. Hierarchical multiple regression analyses revealed that negative meaning-made (i.e. helplessness) was a significant predictor of poor quality of life and increased levels of depression/anxiety above and beyond positive meaning-made (i.e. life meaningfulness, acceptance, and perceived benefits). Correlational analyses and interview data revealed that negative meaning-made was mainly associated with physical and functional disability, while positive meaning-made was mostly related to emotional and psychological well-being. Meanings of varying valence may simultaneously be ascribed to cancer as it impacts different life dimensions, and they may independently influence quality of life and psychosocial adjustment. The presence of positive meaning was not enough to prevent the detrimental effects of negative meaning on psychosocial adjustment and quality of life among individuals taking part in this study. Future attention to negative meaning is warranted, as it may be at least as important as positive meaning in predicting psychosocial adjustment and quality of

Communicating for Climate Change Adaptation: Lessons from a Case Study with Nature-Based Tour Operators

Science.gov (United States)

Timm, K.; Sparrow, E. B.; Pettit, E. C.; Trainor, S. F.; Taylor, K.

2014-12-01

Increasing temperatures are projected to have a positive effect on the length of Alaska's tourism season, but the natural attractions that tourism relies on, such as glaciers, wildlife, fish, or other natural resources, may change. In order to continue to derive benefits from these resources, nature-based tour operators may have to adapt to these changes, and communication is an essential, but poorly understood, component of the climate change adaptation process. The goal of this study was to determine how to provide useful climate change information to nature-based tour operators by answering the following questions: 1. What environmental changes do nature-based tour operators perceive? 2. How are nature-based tour operators responding to climate and environmental change? 3. What climate change information do nature-based tour operators need? To answer these questions, twenty-four nature-based tour operators representing 20 different small and medium sized businesses in Juneau, Alaska were interviewed. The results show that many of Juneau's nature-based tour operators are observing, responding to, and in some cases, actively planning for further changes in the environment. The types of responses tended to vary depending on the participants' certainty in climate change and the perceived risks to their organization. Using these two factors, this study proposes a framework to classify climate change responses for the purpose of generating meaningful information and communication processes that promote adaptation and build adaptive capacity. During the course of the study, several other valuable lessons were learned about communicating about adaptation. The results of this study demonstrate that science communication research has an important place in the practice of promoting and fostering climate change adaptation. While the focus of this study was tour operators, the lessons learned may be valuable to other organizations striving to engage unique groups in climate

Chiral 2d theories from N=4 SYM with varying coupling

Energy Technology Data Exchange (ETDEWEB)

Lawrie, Craig [Institut für Theoretische Physik, Ruprecht-Karls-Universität,Philosophenweg 19, 69120 Heidelberg (Germany); Schäfer-Nameki, Sakura [Mathematical Institute, University of Oxford,Woodstock Road, Oxford, OX2 6GG (United Kingdom); Weigand, Timo [Institut für Theoretische Physik, Ruprecht-Karls-Universität,Philosophenweg 19, 69120 Heidelberg (Germany)

2017-04-19

We study 2d chiral theories arising from 4d N=4 Super-Yang Mills (SYM) with varying coupling τ. The 2d theory is obtained by dimensional reduction of N=4 SYM on a complex curve with a partial topological twist that accounts for the non-constant τ. The resulting 2d theories can preserve (0,n) with n=2,4,6,8 chiral supersymmetry, and have a natural realization in terms of strings from wrapped D3-branes in F-theory. We determine the twisted dimensional reduction, as well as the spectrum and anomaly polynomials of the resulting strings in various dimensions. We complement this by considering the dual M-theory configurations, which can either be realized in terms of M5-branes wrapped on complex surfaces, or M2-branes on curves that result in 1d supersymmetric quantum mechanics.

Is the preference of natural versus man-made scenes driven by bottom-up processing of the visual features of nature?

Directory of Open Access Journals (Sweden)

Omid eKardan

2015-04-01

Full Text Available Previous research has shown that viewing images of nature scenes can have a beneficial effect on memory, attention and mood. In this study we aimed to determine whether the preference of natural versus man-made scenes is driven by bottom-up processing of the low-level visual features of nature. We used participants’ ratings of perceived naturalness as well as aesthetic preference for 307 images with varied natural and urban content. We then quantified ten low-level image features for each image (a combination of spatial and color properties. These features were used to predict aesthetic preference in the images, as well as to decompose perceived naturalness to its predictable (modelled by the low-level visual features and non-modelled aspects. Interactions of these separate aspects of naturalness with the time it took to make a preference judgment showed that naturalness based on low-level features related more to preference when the judgment was faster (bottom-up. On the other hand perceived naturalness that was not modelled by low-level features was related more to preference when the judgment was slower. A quadratic discriminant classification analysis showed how relevant each aspect of naturalness (modelled and non-modelled was to predicting preference ratings, as well as the image features on their own. Finally, we compared the effect of color-related and structure-related modelled naturalness, and the remaining unmodelled naturalness in predicting aesthetic preference. In summary bottom-up (color and spatial properties of natural images captured by our features and the non-modelled naturalness are important to aesthetic judgments of natural and man-made scenes, with each predicting unique variance.

The roles of chronological age and time perspective in memory positivity.

Science.gov (United States)

Kan, Irene P; Garrison, Shaina L; Drummey, Anna B; Emmert, Brian E; Rogers, Leeland L

2018-07-01

The observation that older adults show enhanced cognition for emotionally positive information has been labeled the positivity effect (Reed, Chan, & Mikels, 2014). According to the Socioemotional Selectivity Theory (SST, Carstensen, 1991), a prominent lifespan development theory, cognition is strongly influenced by motivational goals, and these goals are impacted by subjective time perspective. Although the positivity effect is most commonly observed in older adults, as age usually co-varies with time perspective, the SST posits that time perspective, not age, is the key explanatory factor of positivity. We examined the effects of these predictors on positivity in an episodic memory task in younger and older adults and found that age, not time perspective, was a key predictor of memory positivity. Our results add to the growing literature that challenge the notion that time perspective is the driving force behind age-related differences in emotional processing and functioning.

Nature-based Tourism and the Valuation of its Environmental Resources: Economic and Other Aspects

OpenAIRE

Tisdell, Clement A.

2004-01-01

Nature-based tourism has grown in importance in recent decades, and strong links have been established between it and ecotourism. This reflects rising incomes, greater levels of educational attainment and changing values, especially in the Western world. Nature-based tourism is quite varied. Different types of such tourism are identified and their consequences for sustainability of their resource-base are briefly considered. The development and management of nature-based tourism involves many...

Investigation of natural radioactivity level of the waters in the Ningxia Hui Autonomous Region

International Nuclear Information System (INIS)

Jing Yupei; Wang Li; Tian Yi; Ai Xianyuan; Liang Ningbu

1995-01-01

This paper reports the investigation results of natural radioactivity level in river, lake, reservoir, spring, well and tap water in the Ningxia Hui Autonomous Region. There were totally 117 samples collected from 84 measuring points. The results show that the radioactivity level of varied water bodies of the region was within normal natural background

Natural gas; Erdgas

Energy Technology Data Exchange (ETDEWEB)

Graf, Frank [DVGW-Forschungsstelle am KIT, Karlsruhe (Germany); Groeschl, Frank; Wetzel, Uwe [DVGW, Bonn (Germany); Heikrodt, Klaus [Hochschule Ostwestfalen-Lippe, Lemgo (Germany); Krause, Hartmut [DBI Gastechnologisches Institut, An-Institut der TU Bergakademie, Freiberg (Germany); Beestermoeller, Christina; Witschen, Bernhard [Team Consult G.P.E. GmbH, Berlin (Germany); Albus, Rolf; Burmeister, Frank [Gas- und Waerme-Institut Essen e.V., Essen (Germany)

2015-07-01

The reform of the EEG in Germany, a positive global development in natural gas, the decline in oil prices, questions about the security of supply in Europe, and not least the effect of the decision by E.on at the end of 2014 have moved the gas industry. Gas has the lowest CO{sub 2} emissions of fossil fuels. Flexibility, storability, useful for networks and the diversity in the application make it an ideal partner for renewable energy. However, these complementary properties are valued at wind and photovoltaics internationally and nationally different. The situation in the gas power plants remains tense. LNG - liquefied natural gas - is on the rise. [German] Die Reform des EEG in Deutschland, eine positive Entwicklung beim Gas weltweit, der Verfall der Oelpreises, Fragen zur Versorgungssicherheit in Europa und nicht zuletzt die Auswirkung der Entscheidung von E.on Ende 2014 haben die Gaswirtschaft bewegt. Gas weist die geringsten CO{sub 2}-Emissioen der fossilen Energietraeger auf. Flexibilitaet, Speicherbarkeit, Netzdienlichkeit sowie die Vielfalt in der Anwendung machen es zum idealen Partner der erneuerbaren Energien. Allerdings werden diese komplementaeren Eigenschaften zu Wind und Photovoltaik international und national unterschiedlich bewertet. Die Lage bei den Gaskraftwerken bleibt weiter angespannt. LNG - verfluessigtes Erdgas - ist auf dem Vormarsch.

Does natural gas increase the indoor radon levels?

International Nuclear Information System (INIS)

Abdel-Ghany, H.A.; Shabaan, D.H.

2015-01-01

The natural gas is naturally occurring hydrocarbon consists mainly of methane and includes varying amounts of other hydrocarbons, carbon dioxide and other impurities such as: nitrogen, and hydrogen sulfide. It is used domestically and industrially as a preferable energy source compared to coal and oil. Because natural gas is found in deep underground natural formations or associated with other underground hydrocarbon reservoirs, there is a potential to contain radon as a contaminant. This work was designated to measure indoor radon concentrations in dwellings supplied with natural gas compared with those not supplied with it, where radon level was estimated using solid state nuclear track detectors (CR-39). The results showed that radon concentration was significantly higher in dwellings supplied with natural gas, where it was 252.30 versus 136.19 Bqm -3 in dwelling not supplied with natural gas (P < 0.001). The mean values of radon exhalation rate was 0.02 ± 6.34 · 10 -4 Bq · m -2 · h -1 in dwellings supplied with natural gas and 0.01 +- 0.008 Bq · m -2 · h -1 in dwellings lacking it. In addition, a significant difference was observed in the mean annual effective doses (4.33 and 2.34 mSv · y -1 , respectively) between both groups. Conclusively, the data indicate that natural gas may represent a potential source of indoor radon

Cell segmentation in time-lapse fluorescence microscopy with temporally varying sub-cellular fusion protein patterns.

Science.gov (United States)

Bunyak, Filiz; Palaniappan, Kannappan; Chagin, Vadim; Cardoso, M

2009-01-01

Fluorescently tagged proteins such as GFP-PCNA produce rich dynamically varying textural patterns of foci distributed in the nucleus. This enables the behavioral study of sub-cellular structures during different phases of the cell cycle. The varying punctuate patterns of fluorescence, drastic changes in SNR, shape and position during mitosis and abundance of touching cells, however, require more sophisticated algorithms for reliable automatic cell segmentation and lineage analysis. Since the cell nuclei are non-uniform in appearance, a distribution-based modeling of foreground classes is essential. The recently proposed graph partitioning active contours (GPAC) algorithm supports region descriptors and flexible distance metrics. We extend GPAC for fluorescence-based cell segmentation using regional density functions and dramatically improve its efficiency for segmentation from O(N(4)) to O(N(2)), for an image with N(2) pixels, making it practical and scalable for high throughput microscopy imaging studies.

Growth-Enhanced Transgenic Coho Salmon (Oncorhynchus kisutch Strains Have Varied Success in Simulated Streams: Implications for Risk Assessment.

Directory of Open Access Journals (Sweden)

Rosalind A Leggatt

Full Text Available Growth hormone (GH transgenic fish have accelerated growth and could improve production efficiency in aquaculture. However, concern exists regarding potential environmental risks of GH transgenic fish should they escape rearing facilities. While environmental effects have been examined in some GH transgenic models, there is a lack of information on whether effects differ among different constructs or strains of transgenic fish. We compared growth and survival of wild-type coho salmon (Oncorhynchus kisutch fry, a fast-growing GH transgenic strain containing a metallothionein promoter (TMT, and three lines/strains containing a reportedly weaker histone-3 promoter (TH3 in hatchery conditions and semi-natural stream tanks with varying levels of natural food and predators. Rank order of genotype size and survival differed with varying environmental conditions, both within and among experiments. Despite accelerated growth in hatchery conditions, TMT fry gained little or no growth enhancement in stream conditions, had enhanced survival when food was limiting, and inconsistent survival under other conditions. Rank growth was inconsistent in TH3 strains, with one strain having highest, and two strains having the lowest growth in stream conditions, although all TH3 strains had consistently poor survival. These studies demonstrate the importance of determining risk estimates for each unique transgenic model independent of other models.

Study of selected phenotype switching strategies in time varying environment

Energy Technology Data Exchange (ETDEWEB)

Horvath, Denis, E-mail: horvath.denis@gmail.com [Centre of Interdisciplinary Biosciences, Institute of Physics, Faculty of Science, P.J. Šafárik University in Košice, Jesenná 5, 040 01 Košice (Slovakia); Brutovsky, Branislav, E-mail: branislav.brutovsky@upjs.sk [Department of Biophysics, Institute of Physics, P.J. Šafárik University in Košice, Jesenná 5, 040 01 Košice (Slovakia)

2016-03-22

Population heterogeneity plays an important role across many research, as well as the real-world, problems. The population heterogeneity relates to the ability of a population to cope with an environment change (or uncertainty) preventing its extinction. However, this ability is not always desirable as can be exemplified by an intratumor heterogeneity which positively correlates with the development of resistance to therapy. Causation of population heterogeneity is therefore in biology and medicine an intensively studied topic. In this paper the evolution of a specific strategy of population diversification, the phenotype switching, is studied at a conceptual level. The presented simulation model studies evolution of a large population of asexual organisms in a time-varying environment represented by a stochastic Markov process. Each organism disposes with a stochastic or nonlinear deterministic switching strategy realized by discrete-time models with evolvable parameters. We demonstrate that under rapidly varying exogenous conditions organisms operate in the vicinity of the bet-hedging strategy, while the deterministic patterns become relevant as the environmental variations are less frequent. Statistical characterization of the steady state regimes of the populations is done using the Hellinger and Kullback–Leibler functional distances and the Hamming distance. - Highlights: • Relation between phenotype switching and environment is studied. • The Markov chain Monte Carlo based model is developed. • Stochastic and deterministic strategies of phenotype switching are utilized. • Statistical measures of the dynamic heterogeneity reveal universal properties. • The results extend to higher lattice dimensions.

Study of selected phenotype switching strategies in time varying environment

International Nuclear Information System (INIS)

Horvath, Denis; Brutovsky, Branislav

2016-01-01

Population heterogeneity plays an important role across many research, as well as the real-world, problems. The population heterogeneity relates to the ability of a population to cope with an environment change (or uncertainty) preventing its extinction. However, this ability is not always desirable as can be exemplified by an intratumor heterogeneity which positively correlates with the development of resistance to therapy. Causation of population heterogeneity is therefore in biology and medicine an intensively studied topic. In this paper the evolution of a specific strategy of population diversification, the phenotype switching, is studied at a conceptual level. The presented simulation model studies evolution of a large population of asexual organisms in a time-varying environment represented by a stochastic Markov process. Each organism disposes with a stochastic or nonlinear deterministic switching strategy realized by discrete-time models with evolvable parameters. We demonstrate that under rapidly varying exogenous conditions organisms operate in the vicinity of the bet-hedging strategy, while the deterministic patterns become relevant as the environmental variations are less frequent. Statistical characterization of the steady state regimes of the populations is done using the Hellinger and Kullback–Leibler functional distances and the Hamming distance. - Highlights: • Relation between phenotype switching and environment is studied. • The Markov chain Monte Carlo based model is developed. • Stochastic and deterministic strategies of phenotype switching are utilized. • Statistical measures of the dynamic heterogeneity reveal universal properties. • The results extend to higher lattice dimensions.

Anti-Windup Scheme for Practical Control of Positioning Systems

Directory of Open Access Journals (Sweden)

Wahyudi Tarig Faisal and Abdulgani Albagul

2012-10-01

Full Text Available Positioning systems generally need a good controller to achieve high accuracy, fast response and robustness. In addition, ease of controller design and simplicity of controller structure are very important for practical application.  For satisfying these requirements, nominal characteristic trajectory following controller (NCTF has been proposed as a practical point-to-point (PTP positioning control. However, the effect of actuator saturation can not be completely compensated for due to the integrator windup as the plant parameters vary. This paper presents a method to improve the NCTF controller for overcoming the problem of integrator windup using simple and classical tracking anti-windup scheme. The improved NCTF controller is evaluated through simulation using a rotary positioning system. The results show that the improved NCTF controller is adequate to compensate for the effect of integrator windup. Keywords: Positioning, point-to-point, integrator windup, compensation, controller, robustness.

Natural disasters and nontuberculous mycobacteria: a recipe for increased disease?

Science.gov (United States)

Honda, Jennifer R; Bernhard, Jon N; Chan, Edward D

2015-02-01

Infectious diseases acquired by survivors of large-scale natural disasters complicate the recovery process. During events such as tsunamis, hurricanes, earthquakes, and tornados and well into the recovery period, victims often are exposed to water-soil mixtures that have relocated with indigenous microbes. Because nontuberculous mycobacteria (NTM) are ubiquitous in water and soil, there is potential for increased exposure to these organisms during natural disasters. In this hypothesis-driven commentary, we discuss the rise in NTM lung disease and natural disasters and examine the geographic overlap of NTM infections and disaster frequencies in the United States. Moreover, we show an increased number of positive NTM cultures from Louisiana residents in the years following three of the relatively recent epic hurricanes and posit that such natural disasters may help to drive the increased number of NTM infections. Finally, we advocate for increased environmental studies and surveillance of NTM infections before and after natural disasters.

Young women's genital self-image and effects of exposure to pictures of natural vulvas.

Science.gov (United States)

Laan, Ellen; Martoredjo, Daphne K; Hesselink, Sara; Snijders, Nóinín; van Lunsen, Rik H W

2017-12-01

Many women have doubts about the normality of the physical appearance of their vulvas. This study measured genital self-image in a convenience sample of college-educated women, and assessed whether exposure to pictures of natural vulvas influenced their genital self-image. Forty-three women were either shown pictures of natural vulvas (N = 29) or pictures of neutral objects (N = 14). Genital self-image was measured before and after exposure to the pictures and two weeks later. Sexual function, sexual distress, self-esteem and trait anxiety were measured to investigate whether these factors influenced genital self-image scores after vulva picture exposure. A majority of the participants felt generally positively about their genitals. Having been exposed to pictures of natural vulvas resulted in an even more positive genital self-image, irrespective of levels of sexual function, sexual distress, self-esteem and trait anxiety. In the women who had seen the vulva pictures, the positive effect on genital self-image was still present after two weeks. The results of this study seem to indicate that even in young women with a relatively positive genital self-image, exposure to pictures of a large variety of natural vulvas positively affects genital self-image. This finding may suggest that exposure to pictures of natural vulvas may also lead to a more positive genital self-image in women who consider labiaplasty.

Nature of activities and natural, artificial, accidental exposures. Magnitude of these exposures

International Nuclear Information System (INIS)

Aurengo, A.

2009-01-01

The exposure to ionizing radiation (I.R.) is linked to radioelements of organism (9%), earth (12%), cosmic radiation (10%), radon (37%), atmospheric fallout ( nuclear tests 2.5% and industry 0.5%) and to medical procedures (29%). The natural exposure varies in France from 2.5 to 5 mSv by year. In some areas in the world it reaches several tens of mSv by year. The medical exposure is very heterogeneous and concerns particularly old people. For a same examination, the patients exposure varies in an important way ( sometimes from 1 to 10) according to the country, even in France. In France, 250 000 persons are occupationally exposed to ionizing radiation. Among these ones, the most of cases exceeded regulatory limits for exposure to IR concern the health sector. The accidental exposures are in relation with industrial activities (51%) research (20%) civil nuclear (13%) or military (5%) and medical activities (11%). The exposures and then the consequences are very variable, ranging from death to unapparent consequences. in the most of cases a human error is involved and these accidents could have been avoided through measures of prevention and training. (N.C.)

Tendon material properties vary and are interdependent among turkey hindlimb muscles.

Science.gov (United States)

Matson, Andrew; Konow, Nicolai; Miller, Samuel; Konow, Pernille P; Roberts, Thomas J

2012-10-15

The material properties of a tendon affect its ability to store and return elastic energy, resist damage, provide mechanical feedback and amplify or attenuate muscle power. While the structural properties of a tendon are known to respond to a variety of stimuli, the extent to which material properties vary among individual muscles remains unclear. We studied the tendons of six different muscles in the hindlimb of Eastern wild turkeys to determine whether there was variation in elastic modulus, ultimate tensile strength and resilience. A hydraulic testing machine was used to measure tendon force during quasi-static lengthening, and a stress-strain curve was constructed. There was substantial variation in tendon material properties among different muscles. Average elastic modulus differed significantly between some tendons, and values for the six different tendons varied nearly twofold, from 829±140 to 1479±106 MPa. Tendons were stretched to failure, and the stress at failure, or ultimate tensile stress, was taken as a lower-limit estimate of tendon strength. Breaking tests for four of the tendons revealed significant variation in ultimate tensile stress, ranging from 66.83±14.34 to 112.37±9.39 MPa. Resilience, or the fraction of energy returned in cyclic length changes was generally high, and one of the four tendons tested was significantly different in resilience from the other tendons (range: 90.65±0.83 to 94.02±0.71%). An analysis of correlation between material properties revealed a positive relationship between ultimate tensile strength and elastic modulus (r(2)=0.79). Specifically, stiffer tendons were stronger, and we suggest that this correlation results from a constrained value of breaking strain, which did not vary significantly among tendons. This finding suggests an interdependence of material properties that may have a structural basis and may explain some adaptive responses observed in studies of tendon plasticity.

Varying constants, black holes, and quantum gravity

International Nuclear Information System (INIS)

Carlip, S.

2003-01-01

Tentative observations and theoretical considerations have recently led to renewed interest in models of fundamental physics in which certain 'constants' vary in time. Assuming fixed black hole mass and the standard form of the Bekenstein-Hawking entropy, Davies, Davis and Lineweaver have argued that the laws of black hole thermodynamics disfavor models in which the fundamental electric charge e changes. I show that with these assumptions, similar considerations severely constrain 'varying speed of light' models, unless we are prepared to abandon cherished assumptions about quantum gravity. Relaxation of these assumptions permits sensible theories of quantum gravity with ''varying constants,'' but also eliminates the thermodynamic constraints, though the black hole mass spectrum may still provide some restrictions on the range of allowable models

Preliminary quantification of a shape model for etch-pits formed during natural weathering of olivine

International Nuclear Information System (INIS)

Nowicki, M. Anna; Velbel, Michael A.

2011-01-01

Many etch-pits on olivine grains occur as a pair of cone-shaped pits sharing a base, which consequently appear as diamond-shaped etch-pits in cross-section. Quantitative image analysis of back-scattered electron images establishes empirical dimensions of olivine etch-pits in naturally weathered samples from Hawaii and North Carolina. Images of naturally etched olivine were acquired from polished thin-sections by scanning electron microscopy. An average cone-radius-to-height ratio (r:h) of 1.78 was determined for diamond-shaped cross-sections of etch-pits occurring in naturally weathered olivine grains, largely consistent with previous qualitative results. Olivine etch-pit shape as represented by r:h varies from slightly more than half the average value to slightly more than twice the average. Etch-pit shape does not appear to vary systematically with etch-pit size.

Relation of desert pupfish abundance to selected environmental variables in natural and manmade habitats in the Salton Sea basin

Science.gov (United States)

Martin, B.A.; Saiki, M.K.

2005-01-01

We assessed the relation between abundance of desert pupfish, Cyprinodon macularius, and selected biological and physicochemical variables in natural and manmade habitats within the Salton Sea Basin. Field sampling in a natural tributary, Salt Creek, and three agricultural drains captured eight species including pupfish (1.1% of the total catch), the only native species encountered. According to Bray-Curtis resemblance functions, fish species assemblages differed mostly between Salt Creek and the drains (i.e., the three drains had relatively similar species assemblages). Pupfish numbers and environmental variables varied among sites and sample periods. Canonical correlation showed that pupfish abundance was positively correlated with abundance of western mosquitofish, Gambusia affinis, and negatively correlated with abundance of porthole livebearers, Poeciliopsis gracilis, tilapias (Sarotherodon mossambica and Tilapia zillii), longjaw mudsuckers, Gillichthys mirabilis, and mollies (Poecilia latipinnaandPoecilia mexicana). In addition, pupfish abundance was positively correlated with cover, pH, and salinity, and negatively correlated with sediment factor (a measure of sediment grain size) and dissolved oxygen. Pupfish abundance was generally highest in habitats where water quality extremes (especially high pH and salinity, and low dissolved oxygen) seemingly limited the occurrence of nonnative fishes. This study also documented evidence of predation by mudsuckers on pupfish. These findings support the contention of many resource managers that pupfish populations are adversely influenced by ecological interactions with nonnative fishes. ?? Springer 2005.

Assessing the importance of natural behavior for animal welfare

NARCIS (Netherlands)

Bracke, M.B.M.; Hopster, H.

2006-01-01

The concept of natural behavior is a key element in current Dutch policy-making on animal welfare. It emphasizes that animals need positive experiences, in addition to minimized suffering. This paper interprets the concept of natural behavior in the context of the scientific framework for welfare

Antibody responses to Borrelia burgdorferi detected by western blot vary geographically in Canada.

Science.gov (United States)

Ogden, Nicholas H; Arsenault, Julie; Hatchette, Todd F; Mechai, Samir; Lindsay, L Robbin

2017-01-01

Lyme disease is emerging in eastern and central Canada, and most cases are diagnosed using the two-tier serological test (Enzyme Immuno Assay [EIA] followed by Western blot [WB]). Simplification of this algorithm would be advantageous unless it impacts test performance. In this study, accuracy of individual proteins of the IgG WB algorithm in predicting the overall test result in samples from Canadians was assessed. Because Borrelia burgdorferi strains vary geographically in Canada, geographic variations in serological responses were also explored. Metrics of relative sensitivity, specificity and the kappa statistic measure of concordance were used to assess the capacity of responses to individual proteins to predict the overall IgG WB result of 2524 EIA (C6)-positive samples from across Canada. Geographic and interannual variations in proportions of samples testing positive were explored by logistic regression. No one protein was highly concordant with the IgG WB result. Significant variations were found amongst years and geographic regions in the prevalence of samples testing positive using the overall IgG WB algorithm, and for individual proteins of the algorithm. In most cases the prevalence of samples testing positive were highest in Nova Scotia, and lower in samples from Manitoba westwards. These findings suggest that the current two tier test may not be simplified and continued use of the current two-tier test method and interpretation is recommended. Geographic and interannual variations in the prevalence of samples testing positive may be consistent with B. burgdorferi strain variation in Canada, and further studies are needed to explore this.

Antibody responses to Borrelia burgdorferi detected by western blot vary geographically in Canada.

Directory of Open Access Journals (Sweden)

Nicholas H Ogden

Full Text Available Lyme disease is emerging in eastern and central Canada, and most cases are diagnosed using the two-tier serological test (Enzyme Immuno Assay [EIA] followed by Western blot [WB]. Simplification of this algorithm would be advantageous unless it impacts test performance. In this study, accuracy of individual proteins of the IgG WB algorithm in predicting the overall test result in samples from Canadians was assessed. Because Borrelia burgdorferi strains vary geographically in Canada, geographic variations in serological responses were also explored. Metrics of relative sensitivity, specificity and the kappa statistic measure of concordance were used to assess the capacity of responses to individual proteins to predict the overall IgG WB result of 2524 EIA (C6-positive samples from across Canada. Geographic and interannual variations in proportions of samples testing positive were explored by logistic regression. No one protein was highly concordant with the IgG WB result. Significant variations were found amongst years and geographic regions in the prevalence of samples testing positive using the overall IgG WB algorithm, and for individual proteins of the algorithm. In most cases the prevalence of samples testing positive were highest in Nova Scotia, and lower in samples from Manitoba westwards. These findings suggest that the current two tier test may not be simplified and continued use of the current two-tier test method and interpretation is recommended. Geographic and interannual variations in the prevalence of samples testing positive may be consistent with B. burgdorferi strain variation in Canada, and further studies are needed to explore this.

The natural radionuclide concentration and radon exhalation rate of Turkish natural stones

International Nuclear Information System (INIS)

Yasar, O.; Yaprak, G.; Guer, F.

2006-01-01

Geological materials usually contaminated with naturally occurring radioactive materials (NORM) have become a focus great attention. These NORM under certain conditions can reach hazardous contamination levels. Some contamination levels may be sufficiently severe that precautions must be taken. The Turkey has very important natural stones potential with over 5 billion m 3 marble reserves. According to 2002 giving data the number of Turkish stones export is 303 million US Dollars. In this regards, the present study deals with 120 Turkish natural stones. The studied samples were analyzed and the concentrations in Bq/kg dry weight of radioisotopes were determined by gamma-ray spectrometry using HPGe defector in Bq/kg dry weight. For the measurement of the radon exhalation rate, the 'can technique' using sensitive alpha sensitive LR-115 type II plastic defectors were used. The radium equivalent activity varied from 285 Bq/kg to 325 Bq/kg for granite samples and from 2 Bq/kg to 32 Bq/kg for marble samples. The value of radon exhalation rate ranged from 0.06 Bq/m 2 h - 1 to 0.46 Bq/m 2 h - 1 for garnite samples and from 0.006 Bq/m 2 h - 1 to 0.011 Bq/m 2 h - 1 for marble samples. According to the recommended values and the calculated external hazard index values the samples are acceptable for use as building materials and decoration

The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

Science.gov (United States)

Narayan, Siddharth; Beck, Michael W; Reguero, Borja G; Losada, Iñigo J; van Wesenbeeck, Bregje; Pontee, Nigel; Sanchirico, James N; Ingram, Jane Carter; Lange, Glenn-Marie; Burks-Copes, Kelly A

2016-01-01

There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i) a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences) and (ii) analyses of the effectiveness of coastal habitats (natural defences) in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i) analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii) synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii) estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a) the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b) the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become more cost

The Effectiveness, Costs and Coastal Protection Benefits of Natural and Nature-Based Defences.

Directory of Open Access Journals (Sweden)

Siddharth Narayan

Full Text Available There is great interest in the restoration and conservation of coastal habitats for protection from flooding and erosion. This is evidenced by the growing number of analyses and reviews of the effectiveness of habitats as natural defences and increasing funding world-wide for nature-based defences-i.e. restoration projects aimed at coastal protection; yet, there is no synthetic information on what kinds of projects are effective and cost effective for this purpose. This paper addresses two issues critical for designing restoration projects for coastal protection: (i a synthesis of the costs and benefits of projects designed for coastal protection (nature-based defences and (ii analyses of the effectiveness of coastal habitats (natural defences in reducing wave heights and the biophysical parameters that influence this effectiveness. We (i analyse data from sixty-nine field measurements in coastal habitats globally and examine measures of effectiveness of mangroves, salt-marshes, coral reefs and seagrass/kelp beds for wave height reduction; (ii synthesise the costs and coastal protection benefits of fifty-two nature-based defence projects and; (iii estimate the benefits of each restoration project by combining information on restoration costs with data from nearby field measurements. The analyses of field measurements show that coastal habitats have significant potential for reducing wave heights that varies by habitat and site. In general, coral reefs and salt-marshes have the highest overall potential. Habitat effectiveness is influenced by: a the ratios of wave height-to-water depth and habitat width-to-wavelength in coral reefs; and b the ratio of vegetation height-to-water depth in salt-marshes. The comparison of costs of nature-based defence projects and engineering structures show that salt-marshes and mangroves can be two to five times cheaper than a submerged breakwater for wave heights up to half a metre and, within their limits, become

Baseline identification in stable -isotope studies of temperate lotic systems and implications for calculated trophic positions

DEFF Research Database (Denmark)

Kristensen, Peter Brinkmann; Riis, Tenna; Dylmer, Hans Erik

2016-01-01

of two common fish species (three-spined stickleback, Gasterosteus aculeatus, and brown trout Salmo trutta) differed markedly depending on the baseline chosen. The estimated trophic position was lowest when based on Baetidae and highest when using Simuliidae. The trophic position of Gasterosteus...... aculeatus was independent of land use (proxy used=%nature) when based on Gammarus pulex and Simuliidae, and the trophic position of Salmo trutta was independent of land use when based on Simuliidae only. The trophic position estimates based on Baetidae and mean primary consumers correlated with %nature...

Consideration of natural attenuation. In remedation contaminated sites

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-04-15

Upon the proposal submitted by ist Standing committee 5 (Contaminated Sites Committee - ALA) the Federal / State Working Group on Soil protection employed an ad hoc subcommittee dealing with considering natural attenuation in remediating contaminated sites and preparing an inter-State position paper. In the present position paper the way how to consider natural attenuation in practical remediation of contaminated sites is described. The systematic approach outlined allows an understandable decision-finding. A way is shown how the competent soil protection authorities may exercise discretion and in the framework of checking the appropriateness of measures may decide on the implementation of MNA based on a MNA concept (MNA = monitored natural attenuation). It is, however, also explained that when carrying out MNA a decision always made in an individual case is concerned which should be made in a close agreement between the obligated party and the authority.

The effect of spatially varying velocity field on the transport of radioactivity in a porous medium.

Science.gov (United States)

Sen, Soubhadra; Srinivas, C V; Baskaran, R; Venkatraman, B

2016-10-01

In the event of an accidental leak of the immobilized nuclear waste from an underground repository, it may come in contact of the flow of underground water and start migrating. Depending on the nature of the geological medium, the flow velocity of water may vary spatially. Here, we report a numerical study on the migration of radioactivity due to a space dependent flow field. For a detailed analysis, seven different types of velocity profiles are considered and the corresponding concentrations are compared. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

Science.gov (United States)

Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

2016-01-27

A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis.

Sporulation genes associated with sporulation efficiency in natural isolates of yeast.

Science.gov (United States)

Tomar, Parul; Bhatia, Aatish; Ramdas, Shweta; Diao, Liyang; Bhanot, Gyan; Sinha, Himanshu

2013-01-01

Yeast sporulation efficiency is a quantitative trait and is known to vary among experimental populations and natural isolates. Some studies have uncovered the genetic basis of this variation and have identified the role of sporulation genes (IME1, RME1) and sporulation-associated genes (FKH2, PMS1, RAS2, RSF1, SWS2), as well as non-sporulation pathway genes (MKT1, TAO3) in maintaining this variation. However, these studies have been done mostly in experimental populations. Sporulation is a response to nutrient deprivation. Unlike laboratory strains, natural isolates have likely undergone multiple selections for quick adaptation to varying nutrient conditions. As a result, sporulation efficiency in natural isolates may have different genetic factors contributing to phenotypic variation. Using Saccharomyces cerevisiae strains in the genetically and environmentally diverse SGRP collection, we have identified genetic loci associated with sporulation efficiency variation in a set of sporulation and sporulation-associated genes. Using two independent methods for association mapping and correcting for population structure biases, our analysis identified two linked clusters containing 4 non-synonymous mutations in genes - HOS4, MCK1, SET3, and SPO74. Five regulatory polymorphisms in five genes such as MLS1 and CDC10 were also identified as putative candidates. Our results provide candidate genes contributing to phenotypic variation in the sporulation efficiency of natural isolates of yeast.

Impacto da Conversão da Cobertura Natural em Pastagem e Área Urbana sobre Variáveis Biofísicas no Sul do Amazonas

Directory of Open Access Journals (Sweden)

Vagner Marques Pavão

Full Text Available Resumo A substituição da cobertura natural por áreas de pastagem afeta o albedo superficial, que por sua vez influencia no saldo de radiação e na temperatura superficial. Assim, o objetivo desse trabalho foi avaliar os impactos do desmatamento sobre variáveis biofísicas no município de Apuí-AM, por imagens Landsat 5 TM (Thematic Mapper. As imagens utilizadas nesse estudo foram fornecidas pelo Serviço Geológico dos Estados Unidos (USGS. A imagem de 20/07/2010 foi processada por etapas intermediárias do SEBAL (Surface Energy Balance Algorithm for Land. O desmatamento no município de Apuí aumentou em 20% nos últimos 20 anos analisados. O NDVI da Floresta foi 20 e 43% maior que da pastagem e da área urbana, respectivamente. O albedo da superfície na pastagem e na área urbana foram 16% maiores que na área de Floresta e a temperatura de brilho da superfície na pastagem e na área urbana foram 16 e 10% maiores que na área de Floresta, respectivamente. O Rn na área de Floresta foi 8% e 6% maior que na área urbana e na pastagem, respectivamente. Portanto, a conversão da Floresta Amazônica modifica o balanço de radiação com maior disponibilidade de calor sensível da superfície nas áreas de pastagem e urbana.

The influence of train running direction and track supports position on the behaviour of transition zones

Energy Technology Data Exchange (ETDEWEB)

Sañudo Ortega, R.; Miranda Manzanares, M.; Markine, V.; Dell' Olio, L.

2016-07-01

Different types of track infrastructure can be found along railway lines. Separation zones between these different types of structures are the source of a lot of problems. Transition zones on a railway line represent a gradual solution for the problems between conventional railway structure and singular structures located at different points along the line. The different nature, positioning and geometry used with the materials generate changes in the stiffness on both sides of these singular zones leading to an increase in wear and a loss of geometry, with the associated maintenance costs. This article describes the use of mathematical modelling to represent the behaviour of these zones as a function of train running direction and track supports. Available research into transition zones has not studied these separation points where high increases in load are generated for very short periods of time. Finite elements are used to model two types of track (conventional ballasted track and slab track), using a vehicle to dynamically simulate the behaviour in these zones as a function of train running direction and the position of track supports. The magnitudes analysed were the vertical stresses and the vertical displacements under the sleepers and the supports in both types of structure. The results show increased stresses at the separation zone between both structures which varied in magnitude and position depending most of track supports’ location than the train running direction. (Author)

The Interconnectedness between Well-Being and the Natural Environment

Science.gov (United States)

Ferreira, Johanna G.; Venter, Elizabeth

2016-01-01

The purpose of this research was to determine participants' perceptions of the positive influence of the natural environment on their well-being. Through a qualitative study, semistructured interviews were held with selected participants who enjoy activities in the natural environment. From the data analysis, particular themes emerged, namely the…

Natural disasters and suicide: evidence from Japan.

Science.gov (United States)

Matsubayashi, Tetsuya; Sawada, Yasuyuki; Ueda, Michiko

2013-04-01

Previous research shows no consensus as to whether and how natural disasters affect suicide rates in their aftermath. Using prefecture-level panel data of natural disasters and suicide in Japan between 1982 and 2010, we estimate both contemporaneous and lagged effects of natural disasters on the suicide rates of various demographic groups. We find that when the damage caused by natural disasters is extremely large, as in the case of the Great Hanshin-Awaji Earthquake in 1995, suicide rates tend to increase in the immediate aftermath of the disaster and several years later. However, when the damage by natural disasters is less severe, suicide rates tend to decrease after the disasters, especially one or two years later. Thus, natural disasters affect the suicide rates of affected populations in a complicated way, depending on the severity of damages as well as on how many years have passed since the disaster. We also find that the effects of natural disasters on suicide rates vary considerably across demographic groups, which suggests that some population subgroups are more vulnerable to the impact of natural disasters than others. We then test the possibility that natural disasters enhance people's willingness to help others in society, an effect that may work as a protective factor against disaster victims' suicidal risks. We find that natural disasters increase the level of social ties in affected communities, which may mitigate some of the adverse consequence of natural disasters, resulting in a decline in suicide rates. Our findings also indicate that when natural disasters are highly destructive and disruptive, such protective features of social connectedness are unlikely to be enough to compensate for the severe negative impact of disasters on health outcomes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nitrogen leaching from natural ecosystems under global change: a modelling study

Science.gov (United States)

Braakhekke, Maarten C.; Rebel, Karin T.; Dekker, Stefan C.; Smith, Benjamin; Beusen, Arthur H. W.; Wassen, Martin J.

2017-12-01

To study global nitrogen (N) leaching from natural ecosystems under changing N deposition, climate, and atmospheric CO2, we performed a factorial model experiment for the period 1901-2006 with the N-enabled global terrestrial ecosystem model LPJ-GUESS (Lund-Potsdam-Jena General Ecosystem Simulator). In eight global simulations, we used either the true transient time series of N deposition, climate, and atmospheric CO2 as input or kept combinations of these drivers constant at initial values. The results show that N deposition is globally the strongest driver of simulated N leaching, individually causing an increase of 88 % by 1997-2006 relative to pre-industrial conditions. Climate change led globally to a 31 % increase in N leaching, but the size and direction of change varied among global regions: leaching generally increased in regions with high soil organic carbon storage and high initial N status, and decreased in regions with a positive trend in vegetation productivity or decreasing precipitation. Rising atmospheric CO2 generally caused decreased N leaching (33 % globally), with strongest effects in regions with high productivity and N availability. All drivers combined resulted in a rise of N leaching by 73 % with strongest increases in Europe, eastern North America and South-East Asia, where N deposition rates are highest. Decreases in N leaching were predicted for the Amazon and northern India. We further found that N loss by fire regionally is a large term in the N budget, associated with lower N leaching, particularly in semi-arid biomes. Predicted global N leaching from natural lands rose from 13.6 Tg N yr-1 in 1901-1911 to 18.5 Tg N yr-1 in 1997-2006, accounting for reductions of natural land cover. Ecosystem N status (quantified as the reduction of vegetation productivity due to N limitation) shows a similar positive temporal trend but large spatial variability. Interestingly, this variability is more strongly related to vegetation type than N input

Natural radioactivity for some Egyptian building material

International Nuclear Information System (INIS)

Eissa, M. F.; Mostafa, R. M.; Shahin, F.; Hassan, K. F.; Saleh, Z. A.; Yahia, A.

2007-01-01

Study of the radiation hazards for the building materials is interested in most international countries. Measurements of natural radioactivity was verified for some egyptian building materials to assess any possible radiological hazard to man by the use of such materials. The measurements for the level of natural radioactivity in the materials was determined by γ-ray spectrum using HP Ge detector. A track detector Cr-39 was used to measure the radon exhalation rate from these materials. The radon exhalation rates were found to vary from 2.83±0.86 to 41.57 ± 8.38 mBqm -2 h -1 for egyptian alabaster. The absorbed dose rate in air is lower than the international recommended value (55 n Gy h -1 ) for all test samples

Eestlased Karlovy Varys / J. R.

Index Scriptorium Estoniae

J. R.

2007-01-01

Ilmar Raagi mängufilm "Klass" osaleb 42. Karlovy Vary rahvusvahelise filmifestivali võistlusprogrammis "East of the West" ja Asko Kase lühimängufilm "Zen läbi prügi" on valitud festivali kõrvalprogrammi "Forum of Independents"

Modeling passive power generation in a temporally-varying temperature environment via thermoelectrics

International Nuclear Information System (INIS)

Bomberger, Cory C.; Attia, Peter M.; Prasad, Ajay K.; Zide, Joshua M.O.

2013-01-01

This paper presents a model to predict the power generation of a thermoelectric generator in a temporally-varying temperature environment. The model employs a thermoelectric plate sandwiched between two different heat exchangers to convert a temporal temperature gradient in the environment to a spatial temperature gradient within the device suitable for thermoelectric power generation. The two heat exchangers are designed such that their temperatures respond to a change in the environment's temperature at different rates which sets up a temperature differential across the thermoelectric and results in power generation. In this model, radiative and convective heat transfer between the device and its surroundings, and heat flow between the two heat exchangers across the thermoelectric plate are considered. The model is simulated for power generation in Death Valley, CA during the summer using the diurnal variation of air temperature and radiative exchange with the sun and night sky as heat sources and sinks. The optimization of power generation via scaling the device size is discussed. Additional applications of this device are considered. -- Highlights: • Thermoelectric power generation with time-varying temperature is modeled. • The ability to generate power without a natural spatial gradient is demonstrated. • Time dependent heat-transfer and differential heat flow rates are considered. • Optimization of power generation via scaling the device size is discussed

Natural Frequency of F.G. Rectangular Plate by Shear Deformation Theory

International Nuclear Information System (INIS)

Shahrjerdi, Ali; Sapuan, S M; Shahzamanian, M M; Mustapha, F; Zahari, R; Bayat, M

2011-01-01

Natural frequency of functionally graded (F.G.) rectangular plate is carried out by using second-order shear deformation theory (SSDT). The material properties of functionally graded rectangular plates, except the Poisson's ratio, are assumed to vary continuously through the thickness of the plate in accordance with the exponential law distribution. The equations of motion are obtained by energy method. Numerical results for functionally graded plates are given in dimensionless graphical forms and the effects of material properties on natural frequency are determined.

Finite-Time H∞ Filtering for Linear Continuous Time-Varying Systems with Uncertain Observations

Directory of Open Access Journals (Sweden)

Huihong Zhao

2012-01-01

Full Text Available This paper is concerned with the finite-time H∞ filtering problem for linear continuous time-varying systems with uncertain observations and ℒ2-norm bounded noise. The design of finite-time H∞ filter is equivalent to the problem that a certain indefinite quadratic form has a minimum and the filter is such that the minimum is positive. The quadratic form is related to a Krein state-space model according to the Krein space linear estimation theory. By using the projection theory in Krein space, the finite-time H∞ filtering problem is solved. A numerical example is given to illustrate the performance of the H∞ filter.

Comparison of Linear Microinstability Calculations of Varying Input Realism

International Nuclear Information System (INIS)

Rewoldt, G.

2003-01-01

The effect of varying ''input realism'' or varying completeness of the input data for linear microinstability calculations, in particular on the critical value of the ion temperature gradient for the ion temperature gradient mode, is investigated using gyrokinetic and gyrofluid approaches. The calculations show that varying input realism can have a substantial quantitative effect on the results

Comparison of linear microinstability calculations of varying input realism

International Nuclear Information System (INIS)

Rewoldt, G.; Kinsey, J.E.

2004-01-01

The effect of varying 'input realism' or varying completeness of the input data for linear microinstability calculations, in particular on the critical value of the ion temperature gradient for the ion temperature gradient mode, is investigated using gyrokinetic and gyrofluid approaches. The calculations show that varying input realism can have a substantial quantitative effect on the results

NATURAL RESOURCES AVAILABILITY IN A SUSTAINABLE ECONOMY

Directory of Open Access Journals (Sweden)

CĂTĂLINA BONCIU

2013-05-01

Full Text Available In the theoretical and practical approach of the economic life, appears more often the idea of sustainable economic development, of reconciliation between man and nature in attracting and using its resources without interfering in its natural movement and evolution. In this paper we are trying to bring to light the relation between the economic development and the mineral resources, in terms of achieving sustainable development. The place and role of natural factors in the market economy is revealed by bringing to the forefront a number of arguments that demonstrate their vital position in the sustainable growth and development.

Hydroelectrolytic and hormonal modifications related to prolonged bedrest in antiorthostatic position

Science.gov (United States)

Güell, A.; Dupui, Ph.; Fanjaud, G.; Bes, A.; Moatti, J. P.; Gharrib, Cl.

The effects of prolonged bedrest in antiorthostatic position (-4° head down) on electrolyte balance were studied in 4 young volunteers. An increase was noted in sodium excretion during the first 4 days. Plasma renin activity and plasma aldosterone varied in parallel manner during the same period. Potassium balance and creatinine clearance were not significantly modified. In light of these data we feel that prolonged bedrest in antiorthostatic position constitutes an effective way to simulate on earth metabolic and hormonal modifications occurring in man under weightlessness conditions.

Time-varying multiplex network: Intralayer and interlayer synchronization

Science.gov (United States)

Rakshit, Sarbendu; Majhi, Soumen; Bera, Bidesh K.; Sinha, Sudeshna; Ghosh, Dibakar

2017-12-01

A large class of engineered and natural systems, ranging from transportation networks to neuronal networks, are best represented by multiplex network architectures, namely a network composed of two or more different layers where the mutual interaction in each layer may differ from other layers. Here we consider a multiplex network where the intralayer coupling interactions are switched stochastically with a characteristic frequency. We explore the intralayer and interlayer synchronization of such a time-varying multiplex network. We find that the analytically derived necessary condition for intralayer and interlayer synchronization, obtained by the master stability function approach, is in excellent agreement with our numerical results. Interestingly, we clearly find that the higher frequency of switching links in the layers enhances both intralayer and interlayer synchrony, yielding larger windows of synchronization. Further, we quantify the resilience of synchronous states against random perturbations, using a global stability measure based on the concept of basin stability, and this reveals that intralayer coupling strength is most crucial for determining both intralayer and interlayer synchrony. Lastly, we investigate the robustness of interlayer synchronization against a progressive demultiplexing of the multiplex structure, and we find that for rapid switching of intralayer links, the interlayer synchronization persists even when a large number of interlayer nodes are disconnected.

Maxwellian Eye Fixation during Natural Scene Perception

Directory of Open Access Journals (Sweden)

Jean Duchesne

2012-01-01

Full Text Available When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell’s law for each participant and for each scene condition (normal or scrambled. The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes.

Maxwellian Eye Fixation during Natural Scene Perception

Science.gov (United States)

Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A.

2012-01-01

When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

Beam Position and Phase Monitor - Wire Mapping System

International Nuclear Information System (INIS)

Watkins, Heath A.; Shurter, Robert B.; Gilpatrick, John D.; Kutac, Vincent G.; Martinez, Derwin

2012-01-01

The Los Alamos Neutron Science Center (LANSCE) deploys many cylindrical beam position and phase monitors (BPPM) throughout the linac to measure the beam central position, phase and bunched-beam current. Each monitor is calibrated and qualified prior to installation to insure it meets LANSCE requirements. The BPPM wire mapping system is used to map the BPPM electrode offset, sensitivity and higher order coefficients. This system uses a three-axis motion table to position the wire antenna structure within the cavity, simulating the beam excitation of a BPPM at a fundamental frequency of 201.25 MHz. RF signal strength is measured and recorded for the four electrodes as the antenna position is updated. An effort is underway to extend the systems service to the LANSCE facility by replacing obsolete electronic hardware and taking advantage of software enhancements. This paper describes the upgraded wire positioning system's new hardware and software capabilities including its revised antenna structure, motion control interface, RF measurement equipment and Labview software upgrades. The main purpose of the wire mapping system at LANSCE is to characterize the amplitude response versus beam central position of BPPMs before they are installed in the beam line. The wire mapping system is able to simulate a beam using a thin wire and measure the signal response as the wire position is varied within the BPPM aperture.

Influence of Ceiling Suspended Screen Positioning to the Scatter Radiation Levels in Interventional Cardiology

International Nuclear Information System (INIS)

Arandjic, D.; Bozovic, P.; Ciraj-Bjelac, O.; Antic, V.

2013-01-01

The objective of this paper is to identify the effects of the ceiling suspended screen position to the scatter radiation levels in the interventional cardiology. The scatter radiation in terms of ambient dose equivalent H * (10) was measured for various positions of protective screen in the positions of the first operator, nurse and radiographer, at elevations 100-190 cm and in four different angulations of the x-ray tube. To assess the effectiveness of the protective screen, the scattered dose was also measured in the absence of any protection in all four angulations and elevations. To simulate real clinical situation the measurements were performed in the presence of 30 cm PMMA phantom using standard clinical protocol. The utility of protective screen varied for different positions and angulations. Scatter radiation levels varied in the range 70 - 3400 μSv/h for the first operator, 140 - 3200 μSv/h for the nurse and 50 - 560 μSv/h for radiographer. Ceiling suspended screens can provide a substantial level of protection (up to factor 18) in interventional cardiology, but they have to be properly managed and positioned to achieve sufficient level of protection. The guidance for optimal protection is provided in the paper.(author)

[Jena philosophies of nature around 1800].

Science.gov (United States)

Breidbach, O

2000-01-01

This paper describes the situation and the outline of positions in philosophy of nature in Jena about 1800, in focusing on research other than the key figures Schelling and Hegel. In 1789, Schelling introduced philosophy of nature into the course program of Jena University. Already in 1800, two young scientists--a mathematician (Fischer) and a physiologist--reacted, announcing lectures on Schellingian topics. But only in late 1802, younger philosophers offered courses on those topics. From 1802 onwards, lectures were announced by Schad, Krause, Henrici, Hegel, Oken and the botanist Schelver. Apart from the Fisher lecture from 1800, the program of these presentations was based on Schellingian principles. Analyses of the ideas of Schad, Krause and Schelver show that, about 1800, philosophy of nature in Jena conserved basic ideas of the early philosophy of nature of Schelling. Thus, philosophy of nature in this period of Jena University seemed to follow just one line of reasoning.

Natural gas pipeline technology overview.

Energy Technology Data Exchange (ETDEWEB)

Folga, S. M.; Decision and Information Sciences

2007-11-01

The United States relies on natural gas for one-quarter of its energy needs. In 2001 alone, the nation consumed 21.5 trillion cubic feet of natural gas. A large portion of natural gas pipeline capacity within the United States is directed from major production areas in Texas and Louisiana, Wyoming, and other states to markets in the western, eastern, and midwestern regions of the country. In the past 10 years, increasing levels of gas from Canada have also been brought into these markets (EIA 2007). The United States has several major natural gas production basins and an extensive natural gas pipeline network, with almost 95% of U.S. natural gas imports coming from Canada. At present, the gas pipeline infrastructure is more developed between Canada and the United States than between Mexico and the United States. Gas flows from Canada to the United States through several major pipelines feeding U.S. markets in the Midwest, Northeast, Pacific Northwest, and California. Some key examples are the Alliance Pipeline, the Northern Border Pipeline, the Maritimes & Northeast Pipeline, the TransCanada Pipeline System, and Westcoast Energy pipelines. Major connections join Texas and northeastern Mexico, with additional connections to Arizona and between California and Baja California, Mexico (INGAA 2007). Of the natural gas consumed in the United States, 85% is produced domestically. Figure 1.1-1 shows the complex North American natural gas network. The pipeline transmission system--the 'interstate highway' for natural gas--consists of 180,000 miles of high-strength steel pipe varying in diameter, normally between 30 and 36 inches in diameter. The primary function of the transmission pipeline company is to move huge amounts of natural gas thousands of miles from producing regions to local natural gas utility delivery points. These delivery points, called 'city gate stations', are usually owned by distribution companies, although some are owned by

Cupric natural zeolites as microbic ides

International Nuclear Information System (INIS)

Contreras A, D.; Olguin G, M. T.; Alcantara D, D.; Burrola A, C.

2009-01-01

The Escherichia coli and the Candida albicans are considered contamination indicators for what these organisms reflect the water quality. The natural zeolites by their characteristics and properties, they could incorporate to a waters treatment system, as ion exchange, adsorbents and/or microbiocid agents, representing an alternative method of low cost. Inside this investigation work was found that depending on the microorganism type, it varies the quantity of cupric zeolite that is required to carry out the water disinfection, being great for the case of yeasts than the bacteria s. In addition to that marked differences are presented in the required time to reach this process. The characterization of the natural zeolite material, sodium and cupric, was realized by means of scanning electron microscopy, determining the elementary composition (Energy Dispersive Spectroscopy) of each one of them, and by X-ray diffraction. (Author)

Juxtafacet cysts of the lumbar spine: a positional MRI study

International Nuclear Information System (INIS)

Niggemann, Pascal; Kuchta, Johannes; Hoeffer, Janine; Beyer, Hans-Konrad; Grosskurth, Dieter; Delank, Karl-Stefan

2012-01-01

Juxtafacet cysts (JFC) are related to facet joint degeneration. Supine MRI is routinely used to evaluate JFC. However, some JFC are missed and found only intraoperatively. The present study addresses positional MRI features and factors leading to variation in the size of JFC. Fifty patients in whom positional MRI had been performed were investigated retrospectively and 67 distinct intraspinal or intraneuroforaminal were JFC found. Signal intensity, size of the JFC, the presence and variance of a vertebral slip and the angular movement of affected segments were assessed in supine, neutral sitting, flexion (sitting) and extension (standing). The overall movement of the spine and the lordosis angle in different positions were measured. JFC varied in size in segments with unstable slip and increased angular movement (variation of the angle in the affected segment in function: 13.3 degrees compared to 8.7 degrees). JFC with bright signals tended to vary in size compared to JFC with intermediate or low signal intensity (all: p < 0.001). Joint effusion and displacement of effusion lead to formation and variations in the size of JFC. JFC were most prominent in extension: 6.7 mm, less prominent in supine: 5.5 mm and in neutral sitting position: 4.6 mm (all p < 0.05). The detection rate for JFC was 97% for extension, 89% for supine and 78% for neutral sitting. The detection rate of JFC improves with increasing lordosis of the spine and under weight-bearing conditions, particularly when standing. Unstable slipping or increased angular movement affects the size of JFC. (orig.)

Juxtafacet cysts of the lumbar spine: a positional MRI study

Energy Technology Data Exchange (ETDEWEB)

Niggemann, Pascal [University Hospital Bonn, Department of Radiology, Bonn (Germany); Kuchta, Johannes [Interdisziplinaeres Wirbelsaeulenzentrum, Bonn (Germany); Hoeffer, Janine; Beyer, Hans-Konrad [Upright MRT, Cologne (Germany); Grosskurth, Dieter; Delank, Karl-Stefan [Upright MRT, Cologne (Germany); University of Cologne, Department of Orthopaedic and Trauma Surgery, Cologne (Germany)

2012-03-15

Juxtafacet cysts (JFC) are related to facet joint degeneration. Supine MRI is routinely used to evaluate JFC. However, some JFC are missed and found only intraoperatively. The present study addresses positional MRI features and factors leading to variation in the size of JFC. Fifty patients in whom positional MRI had been performed were investigated retrospectively and 67 distinct intraspinal or intraneuroforaminal were JFC found. Signal intensity, size of the JFC, the presence and variance of a vertebral slip and the angular movement of affected segments were assessed in supine, neutral sitting, flexion (sitting) and extension (standing). The overall movement of the spine and the lordosis angle in different positions were measured. JFC varied in size in segments with unstable slip and increased angular movement (variation of the angle in the affected segment in function: 13.3 degrees compared to 8.7 degrees). JFC with bright signals tended to vary in size compared to JFC with intermediate or low signal intensity (all: p < 0.001). Joint effusion and displacement of effusion lead to formation and variations in the size of JFC. JFC were most prominent in extension: 6.7 mm, less prominent in supine: 5.5 mm and in neutral sitting position: 4.6 mm (all p < 0.05). The detection rate for JFC was 97% for extension, 89% for supine and 78% for neutral sitting. The detection rate of JFC improves with increasing lordosis of the spine and under weight-bearing conditions, particularly when standing. Unstable slipping or increased angular movement affects the size of JFC. (orig.)

Inductive Non-Contact Position Sensor

Science.gov (United States)

Youngquist, Robert; Garcia, Alyssa; Simmons, Stephen

2010-01-01

Optical hardware has been developed to measure the depth of defects in the Space Shuttle Orbiter's windows. In this hardware, a mirror is translated such that its position corresponds to the defect's depth, so the depth measurement problem is transferred to a mirror-position measurement problem. This is preferable because the mirror is internal to the optical system and thus accessible. Based on requirements supplied by the window inspectors, the depth of the defects needs to be measured over a range of 200 microns with a resolution of about 100 nm and an accuracy of about 400 nm. These same requirements then apply to measuring the position of the mirror, and in addition, since this is a scanning system, a response time of about 10 ms is needed. A market search was conducted and no sensor that met these requirements that also fit into the available housing volume (less than one cubic inch) was found, so a novel sensor configuration was constructed to meet the requirements. This new sensor generates a nearly linearly varying magnetic field over a small region of space, which can easily be sampled, resulting in a voltage proportional to position. Experiments were done with a range of inductor values, drive voltages, drive frequencies, and inductor shapes. A rough mathematical model was developed for the device that, in most aspects, describes how it operates and what electrical parameters should be chosen for best performance. The final configuration met all the requirements, yielding a small rugged sensor that was easy to use and had nanometer resolution over more than the 200-micron range required. The inductive position sensor is a compact device (potentially as small as 2 cubic centimeters), which offers nanometer-position resolution over a demonstrated range of nearly 1 mm. One of its advantages is the simplicity of its electrical design. Also, the sensor resolution is nearly uniform across its operational range, which is in contrast to eddy current and

Time-Varying Distortions of Binaural Information by Bilateral Hearing Aids

Science.gov (United States)

Rodriguez, Francisco A.; Portnuff, Cory D. F.; Goupell, Matthew J.; Tollin, Daniel J.

2016-01-01

In patients with bilateral hearing loss, the use of two hearing aids (HAs) offers the potential to restore the benefits of binaural hearing, including sound source localization and segregation. However, existing evidence suggests that bilateral HA users’ access to binaural information, namely interaural time and level differences (ITDs and ILDs), can be compromised by device processing. Our objective was to characterize the nature and magnitude of binaural distortions caused by modern digital behind-the-ear HAs using a variety of stimuli and HA program settings. Of particular interest was a common frequency-lowering algorithm known as nonlinear frequency compression, which has not previously been assessed for its effects on binaural information. A binaural beamforming algorithm was also assessed. Wide dynamic range compression was enabled in all programs. HAs were placed on a binaural manikin, and stimuli were presented from an arc of loudspeakers inside an anechoic chamber. Stimuli were broadband noise bursts, 10-Hz sinusoidally amplitude-modulated noise bursts, or consonant–vowel–consonant speech tokens. Binaural information was analyzed in terms of ITDs, ILDs, and interaural coherence, both for whole stimuli and in a time-varying sense (i.e., within a running temporal window) across four different frequency bands (1, 2, 4, and 6 kHz). Key findings were: (a) Nonlinear frequency compression caused distortions of high-frequency envelope ITDs and significantly reduced interaural coherence. (b) For modulated stimuli, all programs caused time-varying distortion of ILDs. (c) HAs altered the relationship between ITDs and ILDs, introducing large ITD–ILD conflicts in some cases. Potential perceptual consequences of measured distortions are discussed. PMID:27698258

Varied line-space gratings: past, present and future

International Nuclear Information System (INIS)

Hettrick, M.C.

1985-08-01

A classically ruled diffraction grating consists of grooves which are equidistant, straight and parallel. Conversely, the so-called ''holographic'' grating (formed by the interfering waves of coherent visible light), although severely constrained by the recording wavelength and recording geometry, has grooves which are typically neither equidistant, straight nor parallel. In contrast, a varied line-space (VLS) grating, in common nomenclature, is a design in which the groove positions are relatively unconstrained yet possess sufficient symmetry to permit mechanical ruling. Such seemingly exotic gratings are no longer only a theoretical curiosity, but have been ruled and used in a wide variety of applications. These include: (1) aberration-corrected normal incidence concave gratings for Seya-Namioka monochromators and optical de-multiplexers, (2) flat-field grazing incidence concave gratings for plasma diagnostics, (3) aberration-corrected grazing incidence plane gratings for space-borne spectrometers, (4) focusing grazing incidence plane grating for synchrotron radiation monochromators, and (5) wavefront generators for visible interferometry of optical surfaces (particularly aspheres). Future prospects of VLS gratings as dispersing elements, wavefront correctors and beamsplitters appear promising. The author discusses the history of VLS gratings, their present applications, and their potential in the future. 61 refs., 24 figs

Harbour porpoise distribution can vary at small spatiotemporal scales in energetic habitats

Science.gov (United States)

Benjamins, Steven; van Geel, Nienke; Hastie, Gordon; Elliott, Jim; Wilson, Ben

2017-07-01

Marine habitat heterogeneity underpins species distribution and can be generated through interactions between physical and biological drivers at multiple spatiotemporal scales. Passive acoustic monitoring (PAM) is used worldwide to study potential impacts of marine industrial activities on cetaceans, but understanding of animals' site use at small spatiotemporal scales (marine renewable energy development (MRED) sites was investigated by deploying dense arrays of C-POD passive acoustic detectors at a wave energy test site (the European Marine Energy Centre [Billia Croo, Orkney]) and by a minor tidal-stream site (Scarba [Inner Hebrides]). Respective arrays consisted of 7 and 11 moorings containing two C-PODs each and were deployed for up to 55 days. Minimum inter-mooring distances varied between 300-600 m. All C-POD data were analysed at a temporal resolution of whole minutes, with each minute classified as 1 or 0 on the basis of presence/absence of porpoise click trains (Porpoise-Positive Minutes/PPMs). Porpoise detection rates were analysed using Generalised Additive Models (GAMs) with Generalised Estimation Equations (GEEs). Although there were many porpoise detections (wave test site: N=3,432; tidal-stream site: N=17,366), daily detection rates varied significantly within both arrays. Within the wave site array (<1 km diameter), average daily detection rates varied from 4.3 to 14.8 PPMs/day. Within the tidal-stream array (<2 km diameter), average daily detection rates varied from 10.3 to 49.7 PPMs/day. GAM-GEE model results for individual moorings within both arrays indicated linkages between porpoise presence and small-scale heterogeneity among different environmental covariates (e.g., tidal phase, time of day). Porpoise detection rates varied considerably but with coherent patterns between moorings only several hundred metres apart and within hours. These patterns presumably have ecological relevance. These results indicate that, in energetically active and

Rousseau’s View of Human Nature and Values Education

OpenAIRE

TÜFENKÇİ, Semra; ÇETİN, Mustafa

2017-01-01

Rousseau considers human nature and everything arising from this nature as good as theiroriginal instances. Therefore, education should reveal the positive emotions in human nature,rather than to sculpt them. Rousseau’s thoughts in Emile, have been a great influence on theeducators, especially on the values education approaches of modern education. In this article,we examine Rousseau’s negative education approach which acknowledges that human natureis merely good; and the importance of negati...

Greening healthcare: practicing as if the natural environment really mattered.

Science.gov (United States)

Irvine, Katherine N; Warber, Sara L

2002-01-01

The natural world's role in human well-being is an essential, yet often forgotten, aspect of healthcare. Of particular importance are the benefits one can derive through interaction with natural environments. While health is an obvious goal of allopathic medicine, many healthcare settings are neither nurturing nor healing. Reincorporating the natural world into the design of settings in which medicine is practiced is one way to complement conventional healing modalities and move healthcare toward being more "green." This article discusses the breadth of existing knowledge available on the positive aspects of interaction with nature and provides a comprehensive theoretical perspective for future research. Computerized searches were conducted using MEDLINE, PsycINFO, the Social and Scientific Science Indices, Dissertation Abstracts, Lexus-Nexus, the University of Michigan library, and the Internet. Searches were conducted from June 2001 through March 2002. Keywords used included health, well-being stress, attention, nature, garden, landscape, restorative, and healing. The literature, published between 1960 and 2001, came from various disciplines, including medicine, public health, nursing psychology, natural resources, history, and landscape architecture. Four components of well-being were used as a framework for literature selection: physical psychological-emotional social, and spiritual. Articles were qualitatively reviewed to extract theories, hypotheses, and experimental evidence. Interaction with nature positively affects multiple dimensions of human health. Physiological effects of stress on the autonomic nervous system are lessened. Psychologically, deficits in attention can be restored or minimized, and people report feeling greater satisfaction with a variety of aspects of life. The presence of the natural world promotes social health by encouraging positive social interaction and lessening the frequency of aggressive behavior. Spiritual well-being is

What's nature got to do with it? A situated historical perspective on socio-natural commodities.

Science.gov (United States)

Peluso, Nancy Lee

2012-01-01

Nature(s) have been commodified since the early days of capitalism, but through processes and socio-natural relationships mediated by their times, histories and localities. While the conditions under which nature's commodities are being trademarked today may be new, their potential for commodification is not. Commodifications of nature should not come as a surprise to environmental social scientists and activists. In this article, I argue that commodification of ‘nature's products, places and processes’ produces new sorts of socio-natures. Situated histories of rubber are particularly relevant because, like carbon, ecosystem services and other recently commodified natures, rubber sits comfortably on the line between a fictitious commodity and a commodity produced explicitly for market: the latex alone has almost no use value, and to give it any exchange value, it requires processing. Yet analytically, it is still considered a ‘natural commodity’, different from ‘synthetic rubber’ and other tradable tree latexes in qualities and socio-natural characteristics. However, it is the social relations constituting rubber's production and trade in various rainforest and agro-forestry environments that have given it a positive or negative connotation, rather than its natural properties or the ecological contexts within which it has been produced. By situating rubber in three of its globally important temporal and spatial contexts, I show how it has been subjected to fairy-tale-like stories that masked and naturalized its commodity lives of the moment. Understanding how history is told or remains untold is thus an essential part of the politics of knowledge production, but also of human experience and mobilization for change. It should be part of any political ecology analysis.

Correlation between natural radiation exposure and cancer mortality, (4)

International Nuclear Information System (INIS)

Noguchi, Kunikazu; Shimizu, Masami; Sairenji, Eiko; Anzai, Ikuro.

1987-01-01

In the previous studies, using Pearson's product moment correlation coefficient, we found that in most cases of cancers, statistically significant positive correlations were observed between natural background radiation exposure rate and crude cancer mortality rate over the period 1950 - 1978. Furthermore, we found that the statistical significance of correlation between natural background radiation exposure rate and the age-adjusted cancer mortality rate in the same period mostly disappeared. We studied the cause of this apparent correlation and found that the prefecture with a higher natural background radiation exposure rate had a greater component ratio of older people. In Japan, a number of prefectures with a higher natural background exposure rate are located in relatively thinly populated districts which have been experiencing an outflow of the younger generation to more highly industrialized and urbanized areas. Therefore, statistically significant positive correlations were observed for almost all cancers between natural background radiation exposure rate and crude cancer mortality rate. In the present investigation, we statistically tested the frequency distributions of natural background radiation exposure rate and age-adjusted cancer mortality rate, and calculated Spearman's rank correlation coefficient between natural background radiation exposure rate and the age-adjusted cancer mortality rate. The frequency distribution of the natural background radiation exposure rate and that of the age-adjusted mortality rate appeared normal in most cases of cancer, and the statistical significance of correlation between natural background exposure rate and the age-adjusted cancer mortality rate did not differ much on the whole, even though we used Spearman's rank correlation coefficient between them. (author)

Correlation between natural radiation exposure and cancer mortality, (4)

Energy Technology Data Exchange (ETDEWEB)

Noguchi, Kunikazu; Shimizu, Masami; Sairenji, Eiko; Anzai, Ikuro

1987-03-01

In the previous studies, using Pearson's product moment correlation coefficient, we found that in most cases of cancers, statistically significant positive correlations were observed between natural background radiation exposure rate and crude cancer mortality rate over the period 1950 - 1978. Furthermore, we found that the statistical significance of correlation between natural background radiation exposure rate and the age-adjusted cancer mortality rate in the same period mostly disappeared. We studied the cause of this apparent correlation and found that the prefecture with a higher natural background radiation exposure rate had a greater component ratio of older people. In Japan, a number of prefectures with a higher natural background exposure rate are located in relatively thinly populated districts which have been experiencing an outflow of the younger generation to more highly industrialized and urbanized areas. Therefore, statistically significant positive correlations were observed for almost all cancers between natural background radiation exposure rate and crude cancer mortality rate. In the present investigation, we statistically tested the frequency distributions of natural background radiation exposure rate and age-adjusted cancer mortality rate, and calculated Spearman's rank correlation coefficient between natural background radiation exposure rate and the age-adjusted cancer mortality rate. The frequency distribution of the natural background radiation exposure rate and that of the age-adjusted mortality rate appeared normal in most cases of cancer, and the statistical significance of correlation between natural background exposure rate and the age-adjusted cancer mortality rate did not differ much on the whole, even though we used Spearman's rank correlation coefficient between them.

Marketingový mix HC Enegie Karlovy Vary

OpenAIRE

Štrobl, Adam

2016-01-01

Title: Marketing mix of HC Energie Karlovy Vary Objectives: This thesis is based on a questionnaire responses obtained from HC Energie Karlovy Vary fans. Its objective is focused on evaluation of their opinions on the marketing mix, their subsequent interpretation, and finally even development of recommendations for improvement based on previous analysis. Methods: Two methods are used to analyse the marketing mix. The first method is qualitative participant observation. The second method is a...

Natural gas conversion new route using halogen derivatives; Nova rota de conversao de gas natural utilizando derivados halogenados

Energy Technology Data Exchange (ETDEWEB)

Noronha, Leandro A.; Mota, Claudio J.A. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Centro de Tecnologia]. E-mail: noronha@iq.ufrj.br; Sousa Aguiar, E. Falabella [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2003-07-01

Natural gas will have important position in the next decades. Nowadays, there is high demand for petrochemicals products, such as ethene and propene. With the nafta price variation, the development of alternative routes from natural gas will be stimulate, as occur in Rio de Janeiro. Between the main technologies for the natural gas use, arise the gas to liquids (GTL) routes for the conversion to hydrocarbons. Therefore, will be studied the transformation of methyl chloride to light olefins (ethene and propene) and other hydrocarbons in zeolitic catalysts. All of these reactions will be simulate occurring in the zeolitic surface, using a cluster that represents very much the catalyst structure. (author)

Õunpuu Karlovy Varys edukas

Index Scriptorium Estoniae

2010-01-01

45. Karlovy Vary filmifestivali võistlusprogrammis "East of the West" märgiti ära Veiko Õunpuu film "Püha Tõnu kiusamine". Peaauhind läks rumeenlase Cristi Puiu filmile "Aurora". Grand prix´sai Augustĺ Vila film "La mosquitera". Teisi preemiasaajaid

CONSUMERS’ PURCHASE INTENTIONS TOWARDS NATURAL COSMETICS

Directory of Open Access Journals (Sweden)

Matea Matić

2016-06-01

Full Text Available The purpose of this paper is to determine which variables influence consumers’ intentions towards purchasing natural cosmetics. Several variables are included in the regression analysis such as age, gender, consumers’ purchase tendency towards organic food, consumers’ new natural cosmetics brands and consumers’ tendency towards health consciousness. The data was collected through an online survey questionnaire using the purposive sample of 204 consumers from the Dubrovnik-Neretva County in March and April of 2015. Various statistical analyses were used such as binary logistic regression and correlation analysis. Binary logistic regression results show that gender, consumers’ purchase tendency towards organic food and consumers’ purchase tendency towards new natural cosmetics brands have an influence on consumer purchase intentions. However, consumers’ tendency towards health consciousness has no influence on consumers’ intentions towards purchasing natural cosmetics. Results of the correlation analysis indicate that there is a strong positive correlation between purchase intentions towards natural cosmetics and consumer references of natural cosmetics. The findings may be useful to online retailers, as well as marketers and practitioners to recognize and better understand the new trends that occur in the industry of natural cosmetics.

Taking a radical position: Evidence for position specific radical representations in Chinese character recognition using masked priming ERP

Directory of Open Access Journals (Sweden)

I-Fan eSu

2012-09-01

Full Text Available In the investigation of orthographic representation of Chinese characters, one question that has stimulated much research is whether radicals (character components are specified for spatial position in a character (e.g. Ding, Peng, & Taft, 2004; Tsang & Chen, 2009. Differing from previous work, component or radical position information in this study is conceived in terms of relative frequency across different positions of characters containing it. A lexical decision task in a masked priming paradigm focusing on radicals with preferred position of occurrence was conducted. A radical position that encompasses more characters than other positions was identified to be the preferred position of a particular radical. The prime that was exposed for 96ms might share a radical with the target in the same or different positions. Moreover, the shared radical appeared either in its preferred or non-preferred position in the target. While response latencies only revealed the effect of graphical similarity, both effects of graphical similarity and radical position preference were found in the ERP results. The former effect was reflected in greater positivity in occipital P1 and greater negativity in N400 for radicals in different positions in prime and target characters. The latter effect manifested as greater negativity in occipital N170 and greater positivity in frontal P200 in the same time window elicited by radicals in their non-preferred position. Equally interesting was the reversal of the effect of radical position preference in N400 with greater negativity associated with radicals in preferred position. These findings identify the early ERP components associated with activation of position-specific radical representations in the orthographic lexicon, and reveal the change in the nature of competition from processing at the radical level to the lexical level.

Interactions between sleeping position and feeding on cardiorespiratory activity in preterm infants.

Science.gov (United States)

Fifer, William P; Myers, Michael M; Sahni, Rakesh; Ohira-Kist, Kiyoko; Kashyap, Sudha; Stark, Raymond I; Schulze, Karl F

2005-11-01

Infants sleeping in the prone position are at greater risk for sudden infant death syndrome (SIDS). Sleep position-dependent changes in cardiorespiratory activity may contribute to this increased risk. Cardiorespiratory activity is also affected by feeding. Twenty prematurely-born infants were studied at 31-36 weeks postconceptional age while sleeping in the prone and supine positions. Heart rate, respiratory rate, and patterns of variability were recorded during interfeed intervals, and effects of position and time after feeding were analyzed by repeated measures analyses of variance. There were significant effects of both sleeping position and time after feeding. Heart rate is higher and heart period variability is lower in the prone position, and the effects of sleeping position on cardiac functioning are more pronounced during the middle of the intrafeed interval. In preterm infants, autonomic responses to nutrient processing modulate the cardiorespiratory effects of sleeping position. Prone sleeping risk may vary with time after feeding. Copyright 2005 Wiley Periodicals, Inc.

Child Temperamental Flexibility Moderates the Relation between Positive Parenting and Adolescent Adjustment

Science.gov (United States)

Rabinowitz, Jill A.; Drabick, Deborah A.G.; Reynolds, Maureen D.; Clark, Duncan B.; Olino, Thomas M.

2016-01-01

Temperamental flexibility and lower positive parenting are associated with internalizing and externalizing problems; however, youth varying in flexibility may be differentially affected by positive parenting in the prediction of symptoms. We examined whether children's flexibility moderated prospective relations between maternal and paternal positive parenting and youth internalizing and externalizing symptoms during adolescence. Participants (N =775, 71% male) and their caregivers completed measures when youth were 10-12 and 12-14 years old. Father positive parenting interacted with child flexibility to predict father-reported internalizing and externalizing problems. Consistent with the diathesis-stress model, children lower in flexibility experienced greater symptoms than children higher in flexibility in lower positive parenting contexts. Among children lower in flexibility, lower paternal positive parenting was associated with greater internalizing and externalizing symptoms compared to higher paternal positive parenting. However, among youth higher in flexibility, symptom levels were similar regardless of whether youth experienced lower or higher paternal positive parenting. PMID:26834305

Time-varying coefficient vector autoregressions model based on dynamic correlation with an application to crude oil and stock markets

International Nuclear Information System (INIS)

Lu, Fengbin; Qiao, Han; Wang, Shouyang; Lai, Kin Keung; Li, Yuze

2017-01-01

This paper proposes a new time-varying coefficient vector autoregressions (VAR) model, in which the coefficient is a linear function of dynamic lagged correlation. The proposed model allows for flexibility in choices of dynamic correlation models (e.g. dynamic conditional correlation generalized autoregressive conditional heteroskedasticity (GARCH) models, Markov-switching GARCH models and multivariate stochastic volatility models), which indicates that it can describe many types of time-varying causal effects. Time-varying causal relations between West Texas Intermediate (WTI) crude oil and the US Standard and Poor’s 500 (S&P 500) stock markets are examined by the proposed model. The empirical results show that their causal relations evolve with time and display complex characters. Both positive and negative causal effects of the WTI on the S&P 500 in the subperiods have been found and confirmed by the traditional VAR models. Similar results have been obtained in the causal effects of S&P 500 on WTI. In addition, the proposed model outperforms the traditional VAR model.

Time-varying coefficient vector autoregressions model based on dynamic correlation with an application to crude oil and stock markets

Energy Technology Data Exchange (ETDEWEB)

Lu, Fengbin, E-mail: fblu@amss.ac.cn [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); Qiao, Han, E-mail: qiaohan@ucas.ac.cn [School of Economics and Management, University of Chinese Academy of Sciences, Beijing 100190 (China); Wang, Shouyang, E-mail: sywang@amss.ac.cn [School of Economics and Management, University of Chinese Academy of Sciences, Beijing 100190 (China); Lai, Kin Keung, E-mail: mskklai@cityu.edu.hk [Department of Management Sciences, City University of Hong Kong (Hong Kong); Li, Yuze, E-mail: richardyz.li@mail.utoronto.ca [Department of Industrial Engineering, University of Toronto (Canada)

2017-01-15

This paper proposes a new time-varying coefficient vector autoregressions (VAR) model, in which the coefficient is a linear function of dynamic lagged correlation. The proposed model allows for flexibility in choices of dynamic correlation models (e.g. dynamic conditional correlation generalized autoregressive conditional heteroskedasticity (GARCH) models, Markov-switching GARCH models and multivariate stochastic volatility models), which indicates that it can describe many types of time-varying causal effects. Time-varying causal relations between West Texas Intermediate (WTI) crude oil and the US Standard and Poor’s 500 (S&P 500) stock markets are examined by the proposed model. The empirical results show that their causal relations evolve with time and display complex characters. Both positive and negative causal effects of the WTI on the S&P 500 in the subperiods have been found and confirmed by the traditional VAR models. Similar results have been obtained in the causal effects of S&P 500 on WTI. In addition, the proposed model outperforms the traditional VAR model.

Global Stability of Polytopic Linear Time-Varying Dynamic Systems under Time-Varying Point Delays and Impulsive Controls

Directory of Open Access Journals (Sweden)

M. de la Sen

2010-01-01

Full Text Available This paper investigates the stability properties of a class of dynamic linear systems possessing several linear time-invariant parameterizations (or configurations which conform a linear time-varying polytopic dynamic system with a finite number of time-varying time-differentiable point delays. The parameterizations may be timevarying and with bounded discontinuities and they can be subject to mixed regular plus impulsive controls within a sequence of time instants of zero measure. The polytopic parameterization for the dynamics associated with each delay is specific, so that (q+1 polytopic parameterizations are considered for a system with q delays being also subject to delay-free dynamics. The considered general dynamic system includes, as particular cases, a wide class of switched linear systems whose individual parameterizations are timeinvariant which are governed by a switching rule. However, the dynamic system under consideration is viewed as much more general since it is time-varying with timevarying delays and the bounded discontinuous changes of active parameterizations are generated by impulsive controls in the dynamics and, at the same time, there is not a prescribed set of candidate potential parameterizations.

Influence of natural organic matter (NOM) coatings on nanoparticle adsorption onto supported lipid bilayers.

Science.gov (United States)

Bo, Zhang; Avsar, Saziye Yorulmaz; Corliss, Michael K; Chung, Minsub; Cho, Nam-Joon

2017-10-05

As the worldwide usage of nanoparticles in commercial products continues to increase, there is growing concern about the environmental risks that nanoparticles pose to biological systems, including potential damage to cellular membranes. A detailed understanding of how different types of nanoparticles behave in environmentally relevant conditions is imperative for predicting and mitigating potential membrane-associated toxicities. Herein, we investigated the adsorption of two popular nanoparticles (silver and buckminsterfullerene) onto biomimetic supported lipid bilayers of varying membrane charge (positive and negative). The quartz crystal microbalance-dissipation (QCM-D) measurement technique was employed to track the adsorption kinetics. Particular attention was focused on understanding how natural organic matter (NOM) coatings affect nanoparticle-bilayer interactions. Both types of nanoparticles preferentially adsorbed onto the positively charged bilayers, although NOM coatings on the nanoparticle and lipid bilayer surfaces could either inhibit or promote adsorption in certain electrolyte conditions. While past findings showed that NOM coatings inhibit membrane adhesion, our findings demonstrate that the effects of NOM coatings are more nuanced depending on the type of nanoparticle and electrolyte condition. Taken together, the results demonstrate that NOM coatings can modulate the lipid membrane interactions of various nanoparticles, suggesting a possible way to improve the environmental safety of nanoparticles. Copyright © 2017 Elsevier B.V. All rights reserved.

Sensitization of Naturally Aged Aluminum 5083 Armor Plate

Science.gov (United States)

2015-07-29

5 - 1 - SENSITIZATION OF NATURALLY AGED ALUMINUM 5083 ARMOR PLATE INTRODUCTION Aluminum -magnesium alloys are important for both ship...boundaries [3,4]. The magnesium-rich phase (normally β-Al3Mg2) is highly anodic with respect to the surrounding aluminum phase, thus is susceptible... alloys , and with varying amounts of debris scattered about the surface consistent with corrosion product, Figure 2b, that often forms over time within