Understanding the Microphysical Properties of Developing Cloud Clusters during TCS-08
2010-09-30
Typhoon Mawar (2005) from the western North Pacific to demonstrate considerable differences in both the development of (Fig. 4), and the microphysical...traces of simulated Typhoon Mawar (2005) showing sea-level pressure on the left axis and maximum wind speed on the right axis. There is considerable...differences in both the speed at which Mawar develops and the final minimum sea-level pressure depending on which microphysics (cloud-resolving
Gender Differences in E-Learning Satisfaction
ERIC Educational Resources Information Center
Gonzalez-Gomez, Francisco; Guardiola, Jorge; Rodriguez, Oscar Martin; Alonso, Miguel Angel Montero
2012-01-01
Student learning skills differ depending on gender. The importance of studying this situation in the classroom is that recommendations can be made taking gender into consideration. In e-learning, the roles of students and teachers change. In line with recent research, the question this paper raises is whether or not gender differences also exist…
A Transfer-in-Pieces Consideration of the Perception of Structure in the Transfer of Learning
ERIC Educational Resources Information Center
Wagner, Joseph F.
2010-01-01
Many approaches to the transfer problem argue that transfer depends on the recognition of the same or similar abstract "structure" in 2 different situations. However, mainstream cognitive perspectives and contrasting Piagetian constructivist accounts differ in their conceptualizations of structure. These differences, not clearly articulated in the…
UC/MALDI-MS analysis of HDL; evidence for density-dependent post-translational modifications
NASA Astrophysics Data System (ADS)
Johnson, Jeffery D.; Henriquez, Ronald R.; Tichy, Shane E.; Russell, David H.; McNeal, Catherine J.; Macfarlane, Ronald D.
2007-12-01
The purpose of this study is to determine whether the nature of the post-translational modifications of the major apolipoproteins of HDL is different for density-distinct subclasses. These subclasses were separated by ultracentrifugation using a novel density-forming solute to yield a high-resolution separation. The serum of two subjects, a control with a normolipidemic profile and a subject with diagnosed cardiovascular disease, was studied. Aliquots of three HDL subclasses were analyzed by MALDI and considerable differences were seen when comparing density-distinct subclasses and also when comparing the two subjects. A detailed analysis of the post-translational modification pattern of apoA-1 shows evidence of considerable protease activity, particularly in the more dense fractions. We conclude that part of the heterogeneity of the population of HDL particles is due to density-dependent protease activity.
Cyber-Terrorism and Cyber-Crime: There Is a Difference
The terms cyber -terrorism and cyber -crime have many varying definitions depending on who is defining them. For example, individuals with expertise in...considerations and, when investigating a cyber -attack, procedural considerations. By examining the strengths and weaknesses of several definitions offered by...national security, law enforcement, industry, law, and scholars, this research constructs a list of parameters to consider when formulating definitions for cyber -terrorism and cyber -crime.
Task Engagement, Cerebral Blood Flow Velocity, and Diagnostic Monitoring for Sustained Attention
ERIC Educational Resources Information Center
Matthews, Gerald; Warm, Joel S.; Reinerman-Jones, Lauren E.; Langheim, Lisa K.; Washburn, David A.; Tripp, Lloyd
2010-01-01
Loss of vigilance may lead to impaired performance in various applied settings including military operations, transportation, and industrial inspection. Individuals differ considerably in sustained attention, but individual differences in vigilance have proven to be hard to predict. The dependence of vigilance on workload factors is consistent…
Falcão, Jorge Tarcísio Da Rocha; Hazin, Izabel
2012-03-01
Køppe's proposition of four layers in theoretical building are used here in the exploration of a specific case of eclectic combination, the use of Piagetian and Vygotskian general approaches to the analysis of proportional reasoning as a cognitive mathematical ability. It is proposed here that the eclectic consideration of these contributions depends on the consideration of their specificity, in the sense that they highlight different aspects of the phenomenon under scrutiny, and also on the consideration of the coherence between this eclectic convergence and premises in terms of schools of thought under which each contribution is framed. We conclude proposing in accordance to S. Køppe's proposal that eclecticism can be valuable and heuristic in theory development, but this contribution will depend largely on the effort in establishing careful relations between the four layers of theory-building.
NASA Astrophysics Data System (ADS)
Samarin, Viacheslav
2014-03-01
Time-dependent Schrödinger equation is numerically solved by difference method for external neutrons of nuclei 6He, 18O, 48Са, 238U at their grazing collisions with energies in the vicinity of a Coulomb barrier. The spin-orbital interaction and Pauli's exclusion principle were taken into consideration during the solution.
Gender issues in the pharmacotherapy of opioid-addicted women: buprenorphine.
Unger, Annemarie; Jung, Erika; Winklbaur, Bernadette; Fischer, Gabriele
2010-04-01
Gender, a biological determinant of mental health and illness, plays a critical role in determining patients' susceptibility, exposure to mental health risks, and related outcomes. Regarding sex differences in the epidemiology of opioid dependence, one third of the patients are women of childbearing age. Women have an earlier age of initiation of substance use and a more rapid progression to drug involvement and dependence than men. Generally few studies exist which focus on the special needs of women in opioid maintenance therapy. The aim of this paper is to provide an overview of treatment options for opioid-dependent women, with a special focus on buprenorphine, and to look at recent findings related to other factors that should be taken into consideration in optimizing the treatment of opioid-dependent women. Issues addressed include the role of gender in the choice of medication assisted treatment, sex differences in pharmacodynamics and pharmacokinetics of buprenorphine drug interactions, cardiac interactions, induction of buprenorphine in pregnant patients, the neonatal abstinence syndrome and breastfeeding. This paper aims to heighten the awareness for the need to take gender into consideration when making treatment decisions in an effort to optimize services and enhance the quality of life of women suffering from substance abuse.
NASA Technical Reports Server (NTRS)
Lewis, Richard F.
2003-01-01
Accurate motor control requires adaptive processes that correct for gradual and rapid perturbations in the properties of the controlled object. The ability to quickly switch between different movement synergies using sensory cues, referred to as context-dependent adaptation, is a subject of considerable interest at present. The potential function of the cerebellum in context-dependent adaptation remains uncertain, but the data reviewed below suggest that it may play a fundamental role in this process.
NASA Technical Reports Server (NTRS)
Blander, M.
1979-01-01
Kinetic effects, for example nucleation constraints and slow reactions, should have been important in nebular condensation. Consideration of these effects leads to the prediction of pressure-dependent compositions and physical properties of nebular condensates which is consistent with (1) the differences between different classes of chondritic meteorites, (2) some of the differences between planets, and (3) the presence of oxidized iron on the moon and in the eucrite parent body (presumably an asteroid) despite the low abundance of volatiles. Diffusion effects appear to be important for understanding oxygen isotope anomalies in refractory inclusions in Allende. The consideration of kinetic effects leads to more information concerning nebular processes than if equilibrium is assumed.
A Twin Study Examining Rumination as a Transdiagnostic Correlate of Psychopathology
Johnson, Daniel P.; Rhee, Soo Hyun; Friedman, Naomi P.; Corley, Robin P.; Munn-Chernoff, Melissa A.; Hewitt, John K.; Whisman, Mark A.
2016-01-01
This study examined the genetic and environmental influences on rumination and its associations with several forms of psychopathology in a sample of adult twins (N = 744). Rumination was significantly associated with major depressive disorder, depressive symptoms, generalized anxiety disorder, eating pathology, and substance dependence symptoms. There were distinct patterns of etiological overlap between rumination and each form of psychopathology; rumination had considerable genetic overlap with depression, modest genetic overlap with eating pathology, and almost no genetic overlap with substance dependence. Findings further suggest considerable overlap between genetic and environmental influences on rumination and those contributing to the covariance between forms of psychopathology. Results were specific to ruminative thought and did not extend to self-reflection. These findings support the conceptualization of rumination as a transdiagnostic correlate and risk factor for psychopathology and also suggest that the biological and environmental mechanisms linking rumination to psychopathology may differ depending on the disorder. PMID:28111610
Considerations for proper selection of dental cements.
Simon, James F; Darnell, Laura A
2012-01-01
Selecting the proper cement for sufficient bond strength has become progressively complicated as the number of different materials for indirect restorations has increased. The success of any restoration is highly dependent on the proper cement being chosen and used. The function of the cement is not only to seal the restoration on the tooth but also, in some cases, to support the retention of the restoration. This ability to strengthen retention varies by the cement chosen by the clinician; therefore, careful consideration must precede cement selection.
ERIC Educational Resources Information Center
Hendriks, Henriette; Hickmann, Maya
2015-01-01
Languages vary considerably in how they represent motion. One major source of variation (Talmy, 2000) depends on whether linguistic systems lexicalize path in the verb (verb-framed languages) or in satellites (satellite-framed languages). This typological difference involves more than different verb types in that it also affects elements outside…
Kim, Shin-Hu; Kim, Jun-Hwan; Park, Myoung-Ae; Hwang, Seong Don; Kang, Ju-Chan
2015-11-01
Rockfish, Sebastes schlegelii (mean weight 14.53 ± 1.14 cm, and mean weight 38.36 ± 3.45 g) were exposed for 4 weeks (2 weeks and 4 weeks) with the different levels of ammonia in the concentrations of 0, 0.1, 0.5, 1.0mg/L at 19 and 24°C. The ammonia exposure induced significant alterations in antioxidant responses. The activities of SOD, CAT, and GST were considerably increased by the ammonia exposure depending on water temperature, whereas the GSH level was notably decreased after 2 and 4 weeks. In the stress indicators, the cortisol and HSP 70 were significantly elevated by the exposure to ammonia depending on water temperature. In innate immune responses, the phagocytosis and lysozyme activity were notably decreased by ammonia exposure depending on water temperature after 2 and 4 weeks. The results suggest that ammonia exposure depending on water temperature can induce the considerable alterations in antioxidant responses, stress, and immune inhibition. Copyright © 2015 Elsevier B.V. All rights reserved.
A thermodynamic approach to model the caloric properties of semicrystalline polymers
NASA Astrophysics Data System (ADS)
Lion, Alexander; Johlitz, Michael
2016-05-01
It is well known that the crystallisation and melting behaviour of semicrystalline polymers depends in a pronounced manner on the temperature history. If the polymer is in the liquid state above the melting point, and the temperature is reduced to a level below the glass transition, the final degree of crystallinity, the amount of the rigid amorphous phase and the configurational state of the mobile amorphous phase strongly depend on the cooling rate. If the temperature is increased afterwards, the extents of cold crystallisation and melting are functions of the heating rate. Since crystalline and amorphous phases exhibit different densities, the specific volume depends also on the temperature history. In this article, a thermodynamically based phenomenological approach is developed which allows for the constitutive representation of these phenomena in the time domain. The degree of crystallinity and the configuration of the amorphous phase are represented by two internal state variables whose evolution equations are formulated under consideration of the second law of thermodynamics. The model for the specific Gibbs free energy takes the chemical potentials of the different phases and the mixture entropy into account. For simplification, it is assumed that the amount of the rigid amorphous phase is proportional to the degree of crystallinity. An essential outcome of the model is an equation in closed form for the equilibrium degree of crystallinity in dependence on pressure and temperature. Numerical simulations demonstrate that the process dependences of crystallisation and melting under consideration of the glass transition are represented.
Oraby, Tamer; Vasilyeva, Olga; Krewski, Daniel; Lutscher, Frithjof
2014-01-07
Behavior and habitat of wildlife animals change seasonally according to environmental conditions. Mathematical models need to represent this seasonality to be able to make realistic predictions about the future of a population and the effectiveness of human interventions. Managing and modeling disease in wild animal populations requires particular care in that disease transmission dynamics is a critical consideration in the etiology of both human and animal diseases, with different transmission paradigms requiring different disease risk management strategies. Since transmission of infectious diseases among wildlife depends strongly on social behavior, mechanisms of disease transmission could also change seasonally. A specific consideration in this regard confronted by modellers is whether the contact rate between individuals is density-dependent or frequency-dependent. We argue that seasonal behavior changes could lead to a seasonal shift between density and frequency dependence. This hypothesis is explored in the case of chronic wasting disease (CWD), a fatal disease that affects deer, elk and moose in many areas of North America. Specifically, we introduce a strategic CWD risk model based on direct disease transmission that accounts for the seasonal change in the transmission dynamics and habitats occupied, guided by information derived from cervid ecology. The model is composed of summer and winter susceptible-infected (SI) equations, with frequency-dependent and density-dependent transmission dynamics, respectively. The model includes impulsive birth events with density-dependent birth rate. We determine the basic reproduction number as a weighted average of two seasonal reproduction numbers. We parameterize the model from data derived from the scientific literature on CWD and deer ecology, and conduct global and local sensitivity analyses of the basic reproduction number. We explore the effectiveness of different culling strategies for the management of CWD: although summer culling seems to be an effective disease eradication strategy, the total culling rate is limited by the requirement to preserve the herd. © 2013 Elsevier Ltd. All rights reserved.
Dynamic Considerations for Control of Closed Life Support Systems
NASA Technical Reports Server (NTRS)
Babcock, P. S.; Auslander, D. M.; Spear, R. C.
1985-01-01
Reliability of closed life support systems depend on their ability to continue supplying the crew's needs during perturbations and equipment failures. The dynamic considerations interact with the basic static design through the sizing of storages, the specification of excess capacities in processors, and the choice of system initial state. A very simple system flow model was used to examine the possibilities for system failures even when there is sufficient storage to buffer the immediate effects of the perturbation. Two control schemes are shown which have different dynamic consequences in response to component failures.
Organ and tissue-dependent effect of resveratrol and exercise on antioxidant defenses of old mice.
Tung, Bui Thanh; Rodriguez-Bies, Elisabet; Thanh, Hai Nguyen; Le-Thi-Thu, Huong; Navas, Plácido; Sanchez, Virginia Motilva; López-Lluch, Guillermo
2015-12-01
Oxidative stress has been considered one of the causes of aging. For this reason, treatments based on antioxidants or those capable of increasing endogenous antioxidant activity have been taken into consideration to delay aging or age-related disease progression. In this paper, we determine if resveratrol and exercise have similar effect on the antioxidant capacity of different organs in old mice. Resveratrol (6 months) and/or exercise (1.5 months) was administered to old mice. Markers of oxidative stress (lipid peroxidation and glutathione) and activities and levels of antioxidant enzymes (SOD, catalase, glutathione peroxidase, glutathione reductase and transferase and thioredoxin reductases, NADH cytochrome B5-reductase and NAD(P)H-quinone acceptor oxidoreductase) were determined by spectrophotometry and Western blotting in different organs: liver, kidney, skeletal muscle, heart and brain. Both interventions improved antioxidant activity in the major organs of the mice. This induction was accompanied by a decrease in the level of lipid peroxidation in the liver, heart and muscle of mice. Both resveratrol and exercise modulated several antioxidant activities and protein levels. However, the effect of resveratrol, exercise or their combination was organ dependent, indicating that different organs respond in different ways to the same stimulus. Our data suggest that physical activity and resveratrol may be of great importance for the prevention of age-related diseases, but that their organ-dependent effect must be taken into consideration to design a better intervention.
A.E. Daniels; J.F. Morrison; L.A. Joyce; N.L. Crookston; S.C. Chen; S.G. McNulty
2012-01-01
Climate scenarios offer one way to identify and examine the land management challenges posed by climate change. Selecting projections, however, requires careful consideration of the natural resources under study, and where and how they are sensitive to climate. Selection also depends on the robustness of different projections for the resources and geographic area of...
The Effect of Self-Directed Work Teams on Work Ethic
ERIC Educational Resources Information Center
Petty, Gregory C.; Lim, Doo Hun; Yoon, Seung Won; Fontan, Johnny
2008-01-01
This study examined the work ethic of manufacturing machine operators between self-directed work teams and traditional work groups using four work ethic subscales: dependable, considerate, ambitious, and cooperative (Dawson, [1999]; Petty, [1991]). Differences in measured work ethic scores were also compared across six demographic variables: age,…
NASA Technical Reports Server (NTRS)
1980-01-01
Cost benefit considerations are extremely important in obtaining the acceptance of dispersed storage and generation (DSG) by the electric utilities. These considerations involved somewhat different economic analyses depending on whether the generation is utility, customer, or combined ownership. It is necessary to get acceptance of more easily understood methods for evaluating the economics of DSG because much of the benefits of DSG may accrue in the generation and transmission portions of the utility system while the costs tend to be centered in the distribution portion of that system. The influence of factors, such as reliability, capital costs, and other economic measures were also investigated.
Shah, Tayyab Ikram; Milosavljevic, Stephan; Bath, Brenna
2017-06-01
This research is focused on methodological challenges and considerations associated with the estimation of the geographical aspects of access to healthcare with a focus on rural and remote areas. With the assumption that GIS-based accessibility measures for rural healthcare services will vary across geographic units of analysis and estimation techniques, which could influence the interpretation of spatial access to rural healthcare services. Estimations of geographical accessibility depend on variations of the following three parameters: 1) quality of input data; 2) accessibility method; and 3) geographical area. This research investigated the spatial distributions of physiotherapists (PTs) in comparison to family physicians (FPs) across Saskatchewan, Canada. The three-steps floating catchment areas (3SFCA) method was applied to calculate the accessibility scores for both PT and FP services at two different geographical units. A comparison of accessibility scores to simple healthcare provider-to-population ratios was also calculated. The results vary considerably depending on the accessibility methods used and the choice of geographical area unit for measuring geographical accessibility for both FP and PT services. These findings raise intriguing questions regarding the nature and extent of technical issues and methodological considerations that can affect GIS-based measures in health services research and planning. This study demonstrates how the selection of geographical areal units and different methods for measuring geographical accessibility could affect the distribution of healthcare resources in rural areas. These methodological issues have implications for determining where there is reduced access that will ultimately impact health human resource priorities and policies. Copyright © 2017 Elsevier Ltd. All rights reserved.
Hamilton, Jessica L.; Stange, Jonathan P.; Abramson, Lyn Y.; Alloy, Lauren B.
2014-01-01
Although cognitive vulnerabilities to depression have received considerable empirical support, little research has evaluated the differential development of cognitive vulnerabilities in adolescent girls and boys. The current study examined the role of stressful life events, as well as sex differences in reactivity and exposure to stress, in the development of negative cognitive style and rumination in a multi-wave study of 382 adolescents. Path analyses indicated that interpersonal dependent stress predicted higher prospective levels of negative cognitive styles and rumination. Additionally, girls’ greater exposure to interpersonal dependent stress explained their higher levels of rumination, which accounted for girls’ higher levels of depressive symptoms than boys. These findings suggest that interpersonal dependent stress is a significant risk factor for the formation of cognitive vulnerabilities to depression during adolescence, and that the sex difference in depressive symptoms may result from girls’ greater exposure to interpersonal dependent stress and ruminative response style than boys. PMID:26509106
Theoretical estimation of Photons flow rate Production in quark gluon interaction at high energies
NASA Astrophysics Data System (ADS)
Al-Agealy, Hadi J. M.; Hamza Hussein, Hyder; Mustafa Hussein, Saba
2018-05-01
photons emitted from higher energetic collisions in quark-gluon system have been theoretical studied depending on color quantum theory. A simple model for photons emission at quark-gluon system have been investigated. In this model, we use a quantum consideration which enhances to describing the quark system. The photons current rate are estimation for two system at different fugacity coefficient. We discussion the behavior of photons rate and quark gluon system properties in different photons energies with Boltzmann model. The photons rate depending on anisotropic coefficient : strong constant, photons energy, color number, fugacity parameter, thermal energy and critical energy of system are also discussed.
Zemskov, A M; Zemskov, V M; Vornovskiĭ, V A; Salomakhin, G G; Vysotskaia, A T
2000-01-01
On the basis of a considerable number of facts--the results of the immunological survey of 197 patients with purulent infections of soft tissues and 103 shigellosis patients--the character and manifestation of immunological disturbances were found to depend on the genetic markers of blood (antigens of the AB0 system) which proved to differ in different type of pathology in patients.
Hematological reference values of healthy Malaysian population.
Roshan, T M; Rosline, H; Ahmed, S A; Rapiaah, M; Wan Zaidah, A; Khattak, M N
2009-10-01
Health and disease can only be distinguished by accurate and reliable reference values of a particular laboratory test. It is now a proven fact that there is considerable variation in hematology reference intervals depending on the demographic and preanalytical variables. There are evidences that values provided by manufacturers do not have appropriate application for all populations. Moreover, reference ranges provided by different laboratory manuals and books also do not solve this problem. We are presenting here normal reference ranges of Malaysian population. These values were determined by using Sysmex XE-2100 and ACL 9000 hematology and coagulation analyzers. Results from this study showed that there were considerable differences in the reference values from manufacturers, western population or laboratory manuals compared with those from the local population.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Maruyama, I., E-mail: ippei@dali.nuac.nagoya-u.ac.jp; Teramoto, A.
Ultra-high-strength concrete with a large unit cement content undergoes considerable temperature increase inside members due to hydration heat, leading to a higher risk of internal cracking. Hence, the temperature dependence of autogenous shrinkage of cement pastes made with silica fume premixed cement with a water–binder ratio of 0.15 was studied extensively. Development of autogenous shrinkage showed different behaviors before and after the inflection point, and dependence on the temperature after mixing and subsequent temperature histories. The difference in autogenous shrinkage behavior poses problems for winter construction because autogenous shrinkage may increase with decrease in temperature after mixing before the inflectionmore » point and with increase in temperature inside concrete members with large cross sections.« less
Shape-Dependent Skin Penetration of Silver Nanoparticles: Does It Really Matter?
Tak, Yu Kyung; Pal, Sukdeb; Naoghare, Pravin K.; Rangasamy, Sabarinathan; Song, Joon Myong
2015-01-01
Advancements in nano-structured materials have facilitated several applications of nanoparticles (NPs). Skin penetration of NPs is a crucial factor for designing suitable topical antibacterial agents with low systemic toxicity. Available reports focus on size-dependent skin penetration of NPs, mainly through follicular pathways. Herein, for the first time, we demonstrate a proof-of-concept study that entails variations in skin permeability and diffusion coefficients, penetration rates and depth-of-penetration of differently shaped silver NPs (AgNPs) via intercellular pathways using both in vitro and in vivo models. The antimicrobial activity of AgNPs is known. Different shapes of AgNPs may exhibit diverse antimicrobial activities and skin penetration capabilities depending upon their active metallic facets. Consideration of the shape dependency of AgNPs in antimicrobial formulations could help developing an ideal topical agent with the highest efficacy and low systemic toxicity. PMID:26584777
Sex Differences in Emotional Responses to "Erotic Literature"
ERIC Educational Resources Information Center
Herrell, James M.
1975-01-01
In this study females (N=32) and males (N=32) read two passages. One described a sexually exploitative experience for a young woman and the other described a sexually positive experience. Response by males and females varied considerably and depended on the interpersonal as well as the erotic content of the passages. (EJT)
Whether or Not to Run in the Rain
ERIC Educational Resources Information Center
Bocci, Franco
2012-01-01
The problem of choosing an optimal strategy for moving in the rain has attracted considerable attention among physicists and other scientists. Taking a novel approach, this paper shows, by studying simple shaped bodies, that the answer depends on the shape and orientation of the moving body and on wind direction and intensity. For different body…
Worldwide Mycotoxins Exposure in Pig and Poultry Feed Formulations
Guerre, Philippe
2016-01-01
The purpose of this review is to present information about raw materials that can be used in pig and poultry diets and the factors responsible for variations in their mycotoxin contents. The levels of mycotoxins in pig and poultry feeds are calculated based on mycotoxin contamination levels of the raw materials with different diet formulations, to highlight the important role the stage of production and the raw materials used can have on mycotoxins levels in diets. Our analysis focuses on mycotoxins for which maximum tolerated levels or regulatory guidelines exist, and for which sufficient contamination data are available. Raw materials used in feed formulation vary considerably depending on the species of animal, and the stage of production. Mycotoxins are secondary fungal metabolites whose frequency and levels also vary considerably depending on the raw materials used and on the geographic location where they were produced. Although several reviews of existing data and of the literature on worldwide mycotoxin contamination of food and feed are available, the impact of the different raw materials used on feed formulation has not been widely studied. PMID:27886128
Physics constraints on double-pulse LIA engineering
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ekdahl, Carl August Jr.
2015-05-20
The options for advanced-radiography double-pulse linear induction accelerators (LIA) under consideration naturally fall into three categories that differ by the number of cells required. Since the two major physics issues, beam breakup (BBU) and corkscrew, are also dependent on the number of cells, it may be useful for the decision process to review the engineering consequences of beam physics constraints for each class. The LIAs can be categorized three different ways, and this report compares the different categories based upon the physics of their beams.
NASA Astrophysics Data System (ADS)
Sugiki, Nao; Hirata, Yoshiki; Matsuo, Kojiro
2017-10-01
Large scale earthquakes occur frequently in Japan in recent years. In the Great East Japan Earthquake that occurred in 2011 and caused major damage, more than 90% of the dead were due to the tsunami. The speed of evacuation is important in considering evacuation at the time of the attack of the tsunami, especially the elderly evacuation speed is assumed to be slower than non-elderly people. Elderly people may have different means of evacuation and speed depending on the composition of the households to which they belong because of the different possibilities of riding in families' driven cars. However, a simulation taking such a difference of evacuation into consideration has not been conducted. The purpose of this study is to conduct a tsunami evacuation simulation in consideration of evacuation measures and speed depending on the type of households belonging to in the tsunami inundation area of Toyohashi city, Japan. In order to conduct the tsunami evacuation simulation considering the household type, detailed data on individual households is necessary. However, it is difficult to obtain from aggregated data such as National Census. Therefore, detailed data on individual households is created by using the household micro data estimation system developed by Sugiki et al. [1]. Evacuation simulation is performed by shortest path search using Esri's ArcGIS Network Analyst's OD cost matrix analysis. The elderly people who cannot complete evacuation by the time of the arrival of the tsunami were found from evacuation simulation results assuming evacuation measures available for each household attribute to which the evacuees belong.
A better understanding of long-range temporal dependence of traffic flow time series
NASA Astrophysics Data System (ADS)
Feng, Shuo; Wang, Xingmin; Sun, Haowei; Zhang, Yi; Li, Li
2018-02-01
Long-range temporal dependence is an important research perspective for modelling of traffic flow time series. Various methods have been proposed to depict the long-range temporal dependence, including autocorrelation function analysis, spectral analysis and fractal analysis. However, few researches have studied the daily temporal dependence (i.e. the similarity between different daily traffic flow time series), which can help us better understand the long-range temporal dependence, such as the origin of crossover phenomenon. Moreover, considering both types of dependence contributes to establishing more accurate model and depicting the properties of traffic flow time series. In this paper, we study the properties of daily temporal dependence by simple average method and Principal Component Analysis (PCA) based method. Meanwhile, we also study the long-range temporal dependence by Detrended Fluctuation Analysis (DFA) and Multifractal Detrended Fluctuation Analysis (MFDFA). The results show that both the daily and long-range temporal dependence exert considerable influence on the traffic flow series. The DFA results reveal that the daily temporal dependence creates crossover phenomenon when estimating the Hurst exponent which depicts the long-range temporal dependence. Furthermore, through the comparison of the DFA test, PCA-based method turns out to be a better method to extract the daily temporal dependence especially when the difference between days is significant.
Mori, T; Yamane, M
1982-02-01
A fractographical study of dental cast gypsum was made in order to correlate the mechanical properties with the microstructure. Wet specimens fractured under tensile stress showed intercrystalline fracture and the tensile strength depended on the porosity present. Thus, it was assumed that tensile strength was dependent on the contact area between individual gypsum crystals and changes in porosity approximated to changes in contact area. Strength differences among specimens of a given W/P ratio, therefore, can be related to differences in intercrystalline contact areas. These theoretical considerations suggest that the classification of dental die stone and dental stone into high and low strength types based on strength properties only would be more practical and less confusing than at present.
[Pharmacokinetics and the clinical effect of bemitil after a single administration].
Boĭko, S S; Bobkov, Iu G; Neznamov, G G; Serebriakova, T V
1986-01-01
It was found on studying a novel psychotropic drug bemitil that after its single administration kinetic curves significantly differed depending on a clinical effect of the test dose in patients with asthenic states. At predomination of the psychoactivating component of action one could note a larger area under the concentration-time relationship curve and a shorter period of half-excretion than in patients with the tranquilizing action. The obtained data on the difference in the drug test dose effect depending on the drug pharmacokinetics should be taken into consideration at determination of bemitil course therapy duration in patients with neuroses and neurosis-like states with predominance of asthenic disturbances in the clinical picture.
ERIC Educational Resources Information Center
Shettleworth, Sara J.
1978-01-01
There has been considerable interest lately in cases where instrumental conditionability appears to depend on the reinforcer used. Here the effects of Pavlovian conditioned stimuli (CSs)on golden hamster behaviors was observed. The intent was to see whether previously reported differences among the behaviors produced by food reinforcement and…
ERIC Educational Resources Information Center
Schuster, David; Cobern, William W.; Adams, Betty A. J.; Undreiu, Adriana; Pleasants, Brandy
2018-01-01
Science curricula and teaching methods vary greatly, depending in part on which facets of science are emphasized, e.g., core disciplinary ideas or science practices and process skills, and perspectives differ considerably on desirable pedagogies. Given the multi-faceted nature of science and the variety of teaching methods found in practice, it is…
Shape-dependent electronic properties of blue phosphorene nano-flakes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bhatia, Pradeep; Swaroop, Ram; Kumar, Ashok, E-mail: ashok@cup.ac.in
In recent year’s considerable attention has been given to the first principles method for modifying and controlling electronic properties of nano-materials. We performed DFT-based calculations on the electronic properties of zigzag-edged nano-flakes of blue phosphorene with three possible shapes namely rectangular, triangular and hexagonal. We observed that HOMO-LUMO gap of zigzag phosphorene nano-flakes with different shapes is ∼2.9 eV with H-passivations and ∼0.7 – 1.2 eV in pristine cases. Electronic properties of blue phosphorene nano-flakes show the strong dependence on their shape. We observed that distributions of molecular orbitals were strongly affected by the different shapes. Zigzag edged considered nanostructuresmore » are non-magnetic and semiconducting in nature. The shape dependent electronic properties may find applications in tunable nano-electronics.« less
On X-Ray Variability in Seyfert Galaxies
NASA Technical Reports Server (NTRS)
Turner, T. J.; George, I. M.; Nandra, K.; Turcan, D.
1999-01-01
This paper presents a quantification of the X-ray variability amplitude for 79 ASCA observations of 36 Seyfert 1 galaxies. We find that consideration of sources with the narrowest permitted lines in the optical band introduces scatter into the established correlation between X-ray variability and nuclear luminosity. Consideration of the X-ray spectral index and variability properties together shows distinct groupings in parameter space for broad and narrow-line Seyfert 1 galaxies, confirming previous studies. A strong correlation is found between hard X-ray variability and FWHM Hbeta. A range of nuclear mass and accretion rate across the Seyfert population can explain the differences observed in X-ray and optical properties. An attractive alternative model, which does not depend on any systematic difference in central mass, is that the circumnuclear gas of NLSy1s is different to BLSy1s in temperature, optical depth, density or geometry.
Nutritional approach of the patient with diabetes mellitus and chronic kidney disease. A case report
Torres Torres, Beatriz; Izaola Jáuregu, Olatz; De Luis Román, Daniel A
2017-05-08
The prevention and treatment of chronic kidney disease (CKD) in diabetes through diet and lifestyle have been a topic of much interest over the years. Consideration of the type and amount of carbohydrate, protein and fat is required for optimal blood glucose control, for clinical outcomes related to renal function and for consideration of risk reduction for cardiovascular disease. Depending on the CKD stage different dietary changes should be considered protein-calorie malnutrition is common in chronic kidney disease patients and is a powerful predictor of morbidity and mortality. We review the nutritional management of a diabetic patient throughout the progression of their CKD.
Lehrner, J; Moser, D; Klug, S; Gleiß, A; Auff, E; Dal-Bianco, P; Pusswald, G
2014-03-01
The goals of this study were to establish prevalence of subjective memory complaints (SMC) and depressive symptoms (DS) and their relation to cognitive functioning and cognitive status in an outpatient memory clinic cohort. Two hundred forty-eight cognitively healthy controls and 581 consecutive patients with cognitive complaints who fulfilled the inclusion criteria were included in the study. A statistically significant difference (p < 0.001) between control group and patient group regarding mean SMC was detected. 7.7% of controls reported a considerable degree of SMC, whereas 35.8% of patients reported considerable SMC. Additionally, a statistically significant difference (p < 0.001) between controls and patient group regarding Beck depression score was detected. 16.6% of controls showed a clinical relevant degree of DS, whereas 48.5% of patients showed DS. An analysis of variance revealed a statistically significant difference across all four groups (control group, SCI group, naMCI group, aMCI group) (p < 0.001). Whereas 8% of controls reported a considerable degree of SMC, 34% of the SCI group, 31% of the naMCI group, and 54% of the aMCI group reported considerable SMC. A two-factor analysis of variance with the factors cognitive status (controls, SCI group, naMCI group, aMCI group) and depressive status (depressed vs. not depressed) and SMC as dependent variable revealed that both factors were significant (p < 0.001), whereas the interaction was not (p = 0.820). A large proportion of patients seeking help in a memory outpatient clinic report considerable SMC, with an increasing degree from cognitively healthy elderly to aMCI. Depressive status increases SMC consistently across groups with different cognitive status.
Motives for using: a comparison of prescription opioid, marijuana and cocaine dependent individuals.
Hartwell, Karen J; Back, Sudie E; McRae-Clark, Aimee L; Shaftman, Stephanie R; Brady, Kathleen T
2012-04-01
Identification of the motives for drug use is critical to the development of effective interventions. Furthermore, consideration of the differences in motives for drug use across substance dependent populations may assist in tailoring interventions. To date, few studies have systematically compared motives for substance use across drug classes. The current study examined motives for drug use between non-treatment seeking individuals with current prescription opioid, marijuana, or cocaine dependence. Participants (N=227) completed the Inventory of Drug-Taking Situations (IDTS; Annis, Turner & Sklar,1997), which contains eight subscales assessing motives for drug use. The findings revealed that prescription opioid dependent individuals scored significantly higher than all other groups on the Physical Discomfort, Testing Personal Control and Conflict with Others subscales. Both the prescription opioid and cocaine dependent groups scored significantly higher than the marijuana group on the Urges or a Temptation to Use subscale. In contrast, marijuana dependent individuals scored highest on the Pleasant Emotions and Pleasant Times with Others subscales. The marked differences revealed in motives for drug use could be used in the development and implementation of specific treatment interventions for prescription opioid, marijuana and cocaine dependent individuals. Published by Elsevier Ltd.
Tax considerations associated with different types of forest ownership
William C. Siegel
2004-01-01
How expenses and income associated with woodland ownership are treated for tax purposes depends on the reason for owning the property, the use being made of it, the owner's taxpayer classification with respect to the property, and the nature of the income or expense item in question. For example, property tax payments can always be deducted by individual taxpayers...
Eddie Bevilacqua
2002-01-01
Comparative analysis of growth responses among trees following natural or anthropogenic disturbances is often confounded when comparing trees of different size because of the high correlation between growth and initial tree size: large trees tend to have higher absolute grow rates. Relative growth rate (RGR) may not be the most suitable size-dependent measure of growth...
78 FR 29117 - After Final Consideration Pilot Program 2.0
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-17
...] After Final Consideration Pilot Program 2.0 AGENCY: United States Patent and Trademark Office, Commerce... Final Consideration Pilot Program (AFCP) to create the After Final Consideration Pilot Program 2.0 (AFCP... without modifications) depending on feedback from the participants and the effectiveness of the pilot...
NASA Astrophysics Data System (ADS)
Rath, Asawari D.; Kundu, S.; Ray, A. K.
2018-02-01
Laser induced photoionization of atoms shows significant dependence on the choice of polarizations of lasers. In multi-step, multi-photon excitation and subsequent ionization of atoms different polarization combinations of the exciting lasers lead to distinctly different ion yields. This fact is exploited in this work to determine total angular momenta of odd-parity energy levels of U I lying at ∼ 4 eV from its ground level using resonance ionization laser polarization spectroscopy in time of flight mass spectrometer. These levels are populated by two-step resonant excitation using two pulsed dye lasers with preset polarizations of choice followed by nonresonant ionization by third laser. The dependence of ionization yield on specific polarizations of the first two lasers is studied experimentally for each level under consideration. This dependence when compared to simulations makes possible unambiguous assignment of J angular momenta to these levels.
Influence of the pressure dependent coefficient of friction on deep drawing springback predictions
NASA Astrophysics Data System (ADS)
Gil, Imanol; Galdos, Lander; Mendiguren, Joseba; Mugarra, Endika; Sáenz de Argandoña, Eneko
2016-10-01
This research studies the effect of considering an advanced variable friction coefficient on the springback prediction of stamping processes. Traditional constant coefficient of friction considerations are being replaced by more advanced friction coefficient definitions. The aim of this work is to show the influence of defining a pressure dependent friction coefficient on numerical springback predictions of a DX54D mild steel, a HSLA380 and a DP780 high strength steel. The pressure dependent friction model of each material was fitted to the experimental data obtained by Strip Drawing tests. Then, these friction models were implemented in a numerical simulation of a drawing process of an industrial automotive part. The results showed important differences between defining a pressure dependent friction coefficient or a constant friction coefficient.
Use of updated material properties in parametric optimization of spaceborne mirrors
NASA Astrophysics Data System (ADS)
Hull, Tony; Westerhoff, Thomas; Weidmann, Guenter; Kirchhoff, Rule
2016-07-01
Spaceborne sensor mirrors need to be both structurally efficient and to maintain figure through thermal transients. Both properties can be represented in a plot showing structural efficiency on one axis and thermal transient resilience on the other. For material selection, engineers have effectively used such charts. However in some cases thermal attributes have improved considerably. Using contemporary values, this comparison chart looks differently. We will discuss how lines of equal merit may be formulated differently depending on the orbit of the mission.
Ultrafast exciton fine structure relaxation dynamics in lead chalcogenide nanocrystals.
Johnson, Justin C; Gerth, Kathrine A; Song, Qing; Murphy, James E; Nozik, Arthur J; Scholes, Gregory D
2008-05-01
The rates of fine structure relaxation in PbS, PbSe, and PbTe nanocrystals were measured on a femtosecond time scale as a function of temperature with no applied magnetic field by cross-polarized transient grating spectroscopy (CPTG) and circularly polarized pump-probe spectroscopy. The relaxation rates among exciton fine structure states follow trends with nanocrystal composition and size that are consistent with the expected influence of material dependent spin-orbit coupling, confinement enhanced electron-hole exchange interaction, and splitting between L valleys that are degenerate in the bulk. The size dependence of the fine structure relaxation rate is considerably different from what is observed for small CdSe nanocrystals, which appears to result from the unique material properties of the highly confined lead chalcogenide quantum dots. Modeling and qualitative considerations lead to conclusions about the fine structure of the lowest exciton absorption band, which has a potentially significant bearing on photophysical processes that make these materials attractive for practical purposes.
Emotion Generation and Emotion Regulation: One or Two Depends on Your Point of View
Gross, James J.; Barrett, Lisa Feldman
2010-01-01
Emotion regulation has the odd distinction of being a wildly popular construct whose scientific existence is in considerable doubt. In this article, we discuss the confusion about whether emotion generation and emotion regulation can and should be distinguished from one another. We describe a continuum of perspectives on emotion, and highlight how different (often mutually incompatible) perspectives on emotion lead to different views about whether emotion generation and emotion regulation can be usefully distinguished. We argue that making differences in perspective explicit serves the function of allowing researchers with different theoretical commitments to collaborate productively despite seemingly insurmountable differences in terminology and methods. PMID:21479078
Crystalline titanate catalyst supports
Anthony, R.G.; Dosch, R.G.
1993-01-05
A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.
Crystalline titanate catalyst supports
Anthony, Rayford G.; Dosch, Robert G.
1993-01-01
A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.
Capital Growth Paths of the Neoclassical Growth Model
Takahashi, Taro
2012-01-01
This paper derives the first-order approximated paths of both types of capital in the two-capital neoclassical growth model. The derived capital growth paths reveal that the short-run growth effect of capital injection differs considerably depending on which type of capital is enhanced. This result demonstrates the importance of well-targeted capital enhancement programs such as public sector projects and foreign aid. PMID:23185344
DOE Office of Scientific and Technical Information (OSTI.GOV)
Foust, C.B.
An incident involving chemical warfare agents requires a unique hazardous materials (HAZMAT) response. As with an HAZMAT event, federal regulations prescribe that responders must be protected from exposure to the chemical agents. But unlike other HAZMAT events, special considerations govern selection of personal protective equipment (PPE). PPE includes all clothing, respirators and monitoring devices used to respond to a chemical release. PPE can differ depending on whether responders are military or civilian personnel.
The Fungal Frontier: A Comparative Analysis of Methods Used in the Study of the Human Gut Mycobiome.
Huseyin, Chloe E; Rubio, Raul Cabrera; O'Sullivan, Orla; Cotter, Paul D; Scanlan, Pauline D
2017-01-01
The human gut is host to a diverse range of fungal species, collectively referred to as the gut "mycobiome". The gut mycobiome is emerging as an area of considerable research interest due to the potential roles of these fungi in human health and disease. However, there is no consensus as to what the best or most suitable methodologies available are with respect to characterizing the human gut mycobiome. The aim of this study is to provide a comparative analysis of several previously published mycobiome-specific culture-dependent and -independent methodologies, including choice of culture media, incubation conditions (aerobic versus anaerobic), DNA extraction method, primer set and freezing of fecal samples to assess their relative merits and suitability for gut mycobiome analysis. There was no significant effect of media type or aeration on culture-dependent results. However, freezing was found to have a significant effect on fungal viability, with significantly lower fungal numbers recovered from frozen samples. DNA extraction method had a significant effect on DNA yield and quality. However, freezing and extraction method did not have any impact on either α or β diversity. There was also considerable variation in the ability of different fungal-specific primer sets to generate PCR products for subsequent sequence analysis. Through this investigation two DNA extraction methods and one primer set was identified which facilitated the analysis of the mycobiome for all samples in this study. Ultimately, a diverse range of fungal species were recovered using both approaches, with Candida and Saccharomyces identified as the most common fungal species recovered using culture-dependent and culture-independent methods, respectively. As has been apparent from ecological surveys of the bacterial fraction of the gut microbiota, the use of different methodologies can also impact on our understanding of gut mycobiome composition and therefore requires careful consideration. Future research into the gut mycobiome needs to adopt a common strategy to minimize potentially confounding effects of methodological choice and to facilitate comparative analysis of datasets.
Evaluation of downscaled, gridded climate data for the conterminous United States
Robert J. Behnke,; Stephen J. Vavrus,; Andrew Allstadt,; Thomas P. Albright,; Thogmartin, Wayne E.; Volker C. Radeloff,
2016-01-01
Weather and climate affect many ecological processes, making spatially continuous yet fine-resolution weather data desirable for ecological research and predictions. Numerous downscaled weather data sets exist, but little attempt has been made to evaluate them systematically. Here we address this shortcoming by focusing on four major questions: (1) How accurate are downscaled, gridded climate data sets in terms of temperature and precipitation estimates?, (2) Are there significant regional differences in accuracy among data sets?, (3) How accurate are their mean values compared with extremes?, and (4) Does their accuracy depend on spatial resolution? We compared eight widely used downscaled data sets that provide gridded daily weather data for recent decades across the United States. We found considerable differences among data sets and between downscaled and weather station data. Temperature is represented more accurately than precipitation, and climate averages are more accurate than weather extremes. The data set exhibiting the best agreement with station data varies among ecoregions. Surprisingly, the accuracy of the data sets does not depend on spatial resolution. Although some inherent differences among data sets and weather station data are to be expected, our findings highlight how much different interpolation methods affect downscaled weather data, even for local comparisons with nearby weather stations located inside a grid cell. More broadly, our results highlight the need for careful consideration among different available data sets in terms of which variables they describe best, where they perform best, and their resolution, when selecting a downscaled weather data set for a given ecological application.
Harris, Alex H S; Ellerbe, Laura; Reeder, Rachelle N; Bowe, Thomas; Gordon, Adam J; Hagedorn, Hildi; Oliva, Elizabeth; Lembke, Anna; Kivlahan, Daniel; Trafton, Jodie A
2013-11-01
Although access to and consideration of pharmacological treatments for alcohol dependence are consensus standards of care, receipt of these medications by patients is generally rare and highly variable across treatment settings. The goal of the present project was to survey and interview the clinicians, managers, and pharmacists affiliated with addiction treatment programs within Veterans Health Administration (VHA) facilities to learn about their perceptions of barriers and facilitators regarding greater and more reliable consideration of pharmacological treatments for alcohol dependence. Fifty-nine participants from 19 high-adopting and 11 low-adopting facilities completed the survey (facility-level response rate = 50%) and 23 participated in a structured interview. The top 4 barriers to increased consideration and use of pharmacotherapy for alcohol dependence were consistent across high- and low-adopting facilities and included perceived low patient demand, pharmacy procedures or formulary restrictions, lack of provider skills or knowledge regarding pharmacotherapy for alcohol dependence, and lack of confidence in treatment effectiveness. Low patient demand was rated as the most important barrier for oral naltrexone and disulfiram, whereas pharmacy or formulary restrictions were rated as the most important barrier for acamprosate and extended-release naltrexone. The 4 strategies rated across low- and high-adopting facilities as most likely to facilitate consideration and use of pharmacotherapy for alcohol dependence were more education to patients about existing medications, more education to health care providers about medications, increased involvement of physicians in treatment for alcohol dependence, and more compelling research on existing medications. This knowledge provides a foundation for designing, deploying, and evaluating targeted implementation efforts.
Considerations for Multiprocessor Topologies
NASA Technical Reports Server (NTRS)
Byrd, Gregory T.; Delagi, Bruce A.
1987-01-01
Choosing a multiprocessor interconnection topology may depend on high-level considerations, such as the intended application domain and the expected number of processors. It certainly depends on low-level implementation details, such as packaging and communications protocols. The authors first use rough measures of cost and performance to characterize several topologies. They then examine how implementation details can affect the realizable performance of a topology.
Heat propagation in dentin during instrumentation with different sonic scaler tips.
Kocher, T; Plagmann, H C
1996-04-01
It is important to know how much heat is generated when a root surface is debrided with sonic scalers and if that heat can be released satisfactorily into the environment. The temperature changes that occurred in dentinal specimens treated with two different sonic scaler tips, used with and without coolant, were studied. Temperature increases of up to 4 degrees C were observed for both tips when a coolant was used. Heat propagation during instrumentation was dependent to a considerable degree on the temperature of the coolant. Sonic scalers should not be used without coolant, because the dentinal temperature may increase up to 35 degrees C, depending on the force of application. A high positive linear correlation was found between increase in temperature and force of application.
What can we learn from Einstein and Arrhenius about the optimal flow of our blood?
Schuster, Stefan; Stark, Heiko
2014-01-01
The oxygen flow in humans and other higher animals depends on the erythrocyte-to-blood volume ratio, the hematocrit. Since it is physiologically favourable when the flow of oxygen transport is maximum it can be assumed that this situation has been achieved during evolution. If the hematocrit was too low, too few erythrocytes could transport oxygen. If it was too high, the blood would be very viscous, so that oxygen supply would again be reduced. The theoretical optimal hematocrit can be calculated by considering the dependence of blood viscosity on the hematocrit. Different approaches to expressing this dependence have been proposed in the literature. Here, we discuss early approaches in hydrodynamics proposed by Einstein and Arrhenius and show that especially the Arrhenius equation is very appropriate for this purpose. We show that despite considerable simplifications such as neglecting the deformation, orientation and aggregation of erythrocytes, realistic hematocrit values of about 40% can be derived based on optimality considerations. Also the prediction that the ratio between the viscosities of the blood and blood plasma at high shear rates nearly equals Euler's constant (2.718) is in good agreement with observed values. Finally, we discuss possible extensions of the theory. For example, we derive the theoretical optimal hematocrit for persevering divers among marine mammals to be 65%, in excellent agreement with the values observed in several species. These considerations are very important for human and animal physiology since oxygen transport is an important factor for medicine and physical performance. © 2013 Elsevier B.V. All rights reserved.
Large Strain Behaviour of ZEK100 Magnesium Alloy at Various Strain Rates
NASA Astrophysics Data System (ADS)
Lévesque, Julie; Kurukuri, Srihari; Mishra, Raja; Worswick, Michael; Inal, Kaan
A constitutive framework based on a rate-dependent crystal plasticity theory is employed to simulate large strain deformation in hexagonal closed-packed metals that deform by slip and twinning. The model allows the twinned zones and the parent matrix to rotate independently. ZEK100 magnesium alloy sheets which significant texture weakening compared to AZ31 sheets are investigated using the model. There is considerable in-plane anisotropy and tension compression asymmetry in the flow behavior of ZEK100. Simulations of uniaxial tension in different directions at various strain rates and the accompanying texture evolution are performed and they are in very good agreement with experimental measurements. The effect of strain rate on the activation of the various slip systems and twinning show that differences in the strain rate dependence of yield stress and Rvalues in ZEK100 have their origin in the activation of different deformation mechanisms.
System and technology considerations for space-based air traffic surveillance
NASA Technical Reports Server (NTRS)
Vaisnys, A.
1986-01-01
This paper describes the system trade-offs examined in a recent study of space-based air traffic surveillance. Three system options, each satisfying a set of different constraints, were considered. The main difference in the technology needed to implement the three systems was determined to be the size of the spacecraft antenna aperture. It was found that essentially equivalent position location accuracy could be achieved with apertures from 50 meters down to less than a meter in diameter, depending on the choice of signal structure and on the desired user update rate.
Challenges Facing 3-D Audio Display Design for Multimedia
NASA Technical Reports Server (NTRS)
Begault, Durand R.; Null, Cynthia H. (Technical Monitor)
1998-01-01
The challenges facing successful multimedia presentation depend largely on the expectations of the designer and end user for a given application. Perceptual limitations in distance, elevation and azimuth sound source simulation differ significantly between headphone and cross-talk cancellation loudspeaker listening and therefore must be considered. Simulation of an environmental context is desirable but the quality depends on processing resources and lack of interaction with the host acoustical environment. While techniques such as data reduction of head-related transfer functions have been used widely to improve simulation fidelity, another approach involves determining thresholds for environmental acoustic events. Psychoacoustic studies relevant to this approach are reviewed in consideration of multimedia applications
Application of speckle dynamics for studying metabolic activity of cell cultures with herpes virus
NASA Astrophysics Data System (ADS)
Vladimirov, A. P.; Bakharev, A. A.; Malygin, A. S.; Mikhaylova, J. A.; Borodin, E. M.; Poryvayeva, A. P.; Glinskikh, N. P.
2014-05-01
The report considers the results of the experiments in which digital values of light intensity I and the image area correlation index η values were recorded on a real-time basis for one or two days. Three cell cultures with viruses along with intact cultures were investigated. High correlation of dependence of η values on time t values was demonstrated for three cultures. The η=η(t) and I=I(t) dependences for cells with and without viruses differ considerably. It was shown that the presence of viruses could be determined as early as ten minutes after measurements were started.
Hogan, Dianna; Arthaud, Greg; Brookshire, David; Gunther, Tom; Pincetl, Stephanie; Shapiro, Carl; Van Horne, Bea
2011-01-01
The appropriate use of institutional structures, including markets, to integrate ecosystem services into decision making depends on the players and characteristics of the specific situation (such as stakeholders, the ecosystem, resources, and the political environment). Incorporating ecosystem service values into decisions requires consideration of place-based social, cultural, economic, and landscape characteristics and institutions. Thus, a single, prescribed solution will not work-various institutional strategies must be used in different situations. Market-based approaches require appropriate regulations, monitoring, and enforcement, depending on the situation and place. Further, market approaches will need to be coupled with nonmarket approaches into an integrated institutional framework.
NASA Astrophysics Data System (ADS)
Abdelsalam, Hazem; Elhaes, Hanan; Ibrahim, Medhat A.
2018-03-01
The energy gap and dipole moment of chemically functionalized graphene quantum dots are investigated by density functional theory. The energy gap can be tuned through edge passivation by different elements or groups. Edge passivation by oxygen considerably decreases the energy gap in hexagonal nanodots. Edge states in triangular quantum dots can also be manipulated by passivation with fluorine. The dipole moment depends on: (a) shape and edge termination of the quantum dot, (b) attached group, and (c) position to which the groups are attached. Depending on the position of attached groups, the total dipole can be increased, decreased, or eliminated.
AFS men and women differ most in their lifestyle choices
Connelly, N.A.; Brown, T.L.; Hardiman, J.M.
2006-01-01
The American Fisheries Society sponsored a survey to examine the career development choices of men and women and how they might differ by gender. A random sample of 700 men and 700 women was selected from the AFS membership database. The survey was mailed out in October 2004 and 991 questionnaires were returned for an adjusted response rate of 71%. Some differences exist between men and women in the areas of interest development, education, and employment, but the substantive differences occur in lifestyle choices. Women with a fisheries career are less likely to be married than men, even when age is controlled for, and women who are married are more likely to have dual-career considerations than their male counterparts. Among respondents without dependents in their home during their professional career, twice as many women as men think having children will adversely affect their career. For those with dependents, more than twice as many women as men said they had to put their career "on hold" because of their dependents. While AFS members do not represent all members of the fisheries profession, their experiences shed substantial light on the lifestyle choices likely faced by most members of the profession.
A supervised learning rule for classification of spatiotemporal spike patterns.
Lilin Guo; Zhenzhong Wang; Adjouadi, Malek
2016-08-01
This study introduces a novel supervised algorithm for spiking neurons that take into consideration synapse delays and axonal delays associated with weights. It can be utilized for both classification and association and uses several biologically influenced properties, such as axonal and synaptic delays. This algorithm also takes into consideration spike-timing-dependent plasticity as in Remote Supervised Method (ReSuMe). This paper focuses on the classification aspect alone. Spiked neurons trained according to this proposed learning rule are capable of classifying different categories by the associated sequences of precisely timed spikes. Simulation results have shown that the proposed learning method greatly improves classification accuracy when compared to the Spike Pattern Association Neuron (SPAN) and the Tempotron learning rule.
Dependent personality disorder: a critical review.
Disney, Krystle L
2013-12-01
Dependent personality disorder (DPD) has evolved from an abstract idea rooted in a historic and psychoanalytic context to a codified diagnosis in the DSM-IV-TR. This comprehensive review paper chronicles the evolution of DPD through each version of the DSM. Major topics relevant to the disorder are also investigated, including gender and cultural considerations, stability and manifestations of DPD across different developmental stages, comorbidity issues, and others. The purpose of this review is to provide a broad yet comprehensive examination of the complex angles of maladaptive dependency and to identify essential next steps in furthering our knowledge of this disorder. The paper concludes with a discussion of shortcomings in the body of research relevant to DPD, along with specific suggestions for improvement in this field of study. © 2013.
Evidence for history-dependence of influenza pandemic emergence
NASA Astrophysics Data System (ADS)
Hill, Edward M.; Tildesley, Michael J.; House, Thomas
2017-03-01
Influenza A viruses have caused a number of global pandemics, with considerable mortality in humans. Here, we analyse the time periods between influenza pandemics since 1700 under different assumptions to determine whether the emergence of new pandemic strains is a memoryless or history-dependent process. Bayesian model selection between exponential and gamma distributions for these time periods gives support to the hypothesis of history-dependence under eight out of nine sets of modelling assumptions. Using the fitted parameters to make predictions shows a high level of variability in the modelled number of pandemics from 2010-2110. The approach we take here relies on limited data, so is uncertain, but it provides cheap, safe and direct evidence relating to pandemic emergence, a field where indirect measurements are often made at great risk and cost.
Frequency and Thermal Behavior of Acoustic Absorption in ɛ-GaSe Crystals
NASA Astrophysics Data System (ADS)
Dzhafarova, S. Z.
2018-04-01
The paper presents results of measuring acoustic absorption in ɛ-GaSe crystals. The absorption of a longitudinal wave which propagates normal to the crystal layers, quadratically depends on frequency. However, it does not depend on temperature, i.e. it displays an Akhiezer behavior although its absolute value considerably exceeds the expected. The analysis of the frequency and thermal behavior of absorption of piezoelectric waves propagating along the layers, includes the deduction of contribution made by the interaction between waves and charge carriers. This analysis shows the linear dependence between the lattice absorption of these waves and the frequency. The linear frequency and weak temperature dependences of the acoustic absorption characterize the additional ultra-Akhiezer absorption in glasses. In our case, it can be caused by various polytypes forming in GaSe crystals which differ merely in a mutual arrangement of layers.
Ajay, Jayanth S; Komarova, Ksenia G; Remacle, Francoise; Levine, R D
2018-06-05
Isotopic fractionation in the photodissociation of N 2 could explain the considerable variation in the 14 N/ 15 N ratio in different regions of our galaxy. We previously proposed that such an isotope effect is due to coupling of photoexcited bound valence and Rydberg electronic states in the frequency range where there is strong state mixing. We here identify features of the role of the mass in the dynamics through a time-dependent quantum-mechanical simulation. The photoexcitation of N 2 is by an ultrashort pulse so that the process has a sharply defined origin in time and so that we can monitor the isolated molecule dynamics in time. An ultrafast pulse is necessarily broad in frequency and spans several excited electronic states. Each excited molecule is therefore not in a given electronic state but in a superposition state. A short time after excitation, there is a fairly sharp onset of a mass-dependent large population transfer when wave packets on two different electronic states in the same molecule overlap. This coherent overlap of the wave packets on different electronic states in the region of strong coupling allows an effective transfer of population that is very mass dependent. The extent of the transfer depends on the product of the populations on the two different electronic states and on their relative phase. It is as if two molecules collide but the process occurs within one molecule, a molecule that is simultaneously in both states. An analytical toy model recovers the (strong) mass and energy dependence.
NASA Astrophysics Data System (ADS)
Rinnerbauer, V.; Schmidegg, K.; Hohage, M.; Sun, L. D.; Flores-Camacho, J. M.; Zeppenfeld, P.
2009-06-01
We have used reflectance difference spectroscopy (RDS) and its extension, azimuth-dependent RDS (ADRDS), to study the properties of sputtered and evaporated nickel films on biaxially oriented poly(ethylene terephtalate) (PET) films in a roll to roll web-coating process. From the full set of ADRDS spectra we extract and analyze both the intrinsic RDS spectra and the azimuthal orientation of the effective optical anisotropy of the samples. From the latter, contributions to the RDS spectra arising from the nickel layer and the PET substrate with different orientations of the optical eigenaxes can be inferred. We find an attenuation of the characteristic RDS signal of the PET substrate with increasing nickel film thickness which is in good agreement with the theoretical prediction. For film thicknesses above 20 nm another contribution to the RDS signal attributed to the optical anisotropy of the deposited nickel layers can be observed. Its strength depends on the deposition method, and is considerably larger for evaporated films than for sputtered ones. With increasing nickel film thickness, the azimuthal orientation of the sample anisotropy changes from the initial value of the PET substrate by about 20° toward the machine direction of the foil. We demonstrate that RDS is also a valuable tool for inline monitoring in the roll to roll process, as the attenuation of the RDS signal, under proper consideration of the orientation of the effective anisotropy, is a function of the film thickness and characteristic for the deposited material.
Robot arm system for automatic satellite capture and berthing
NASA Technical Reports Server (NTRS)
Nishida, Shinichiro; Toriu, Hidetoshi; Hayashi, Masato; Kubo, Tomoaki; Miyata, Makoto
1994-01-01
Load control is one of the most important technologies for capturing and berthing free flying satellites by a space robot arm because free flying satellites have different motion rates. The performance of active compliance control techniques depend on the location of the force sensor and the arm's structural compliance. A compliance control technique for the robot arm's structural elasticity and a consideration for an end-effector appropriate for it are presented in this paper.
Full-Scale Transport Controlled Impact Demonstration Program Photographic/Video Coverage.
1986-04-01
Early morning haze - wind, dust - the many different fores of environmental air pollution will be taken into consideration. Depending on morning...NASA 21 PHOTO/TV VEHICLE NASA 25 GMO GROUND CREW ONBOARD CAMERAS * FIRE FIGHTING PHOTO NASA 25 PHOTO/TV OPERATIONS DIRECTOR L-2 *Jv. *,’.e...Airline Pilots Association Int. Lockheed 1625 Massachusetts Avenue, NW. Department 7475/Building 229A Washington, DC 20036 P.O. Box 551, Plant 2 Burbank
Analysis of microstrip patch antennas using finite difference time domain method
NASA Astrophysics Data System (ADS)
Reineix, Alain; Jecko, Bernard
1989-11-01
The study of microstrip patch antennas is directly treated in the time domain, using a modified finite-difference time-domain (FDTD) method. Assuming an appropriate choice of excitation, the frequency dependence of the relevant parameters can readily be found using the Fourier transform of the transient current. The FDTD method allows a rigorous treatment of one or several dielectric interfaces. Different types of excitation can be taken into consideration (coaxial, microstrip lines, etc.). Plotting the spatial distribution of the current density gives information about the resonance modes. The usual frequency-depedent parameters (input impedance, radiation pattern) are given for several examples.
Amini, Reza; Sahaf, Robab; Kaldi, Alireza; Haghani, Hamid; Davatgaran, Keyvan; Masoumi, Mehdi; Hayatbakhsh, Reza; Rassafiani, Mehdi
2013-07-01
Assessment of activities of daily living (ADL) can be helpful for designing individualized rehabilitation programs for disabled individuals. Measuring and comparing the basic ADL (BADL) and instrumental ADL (IADL) independence between middle aged and senior Iranian blind war survivors (IBWS) was the aim of this study. This cross-sectional study assessed BADL and IADL of 312 blind war survivors, using the Barthel Index and the Lawton-Bordy scale. Data collection was carried out in a recreational event for the blind war survivors in Mashhad, Iran, 2008. The majority of the participants were male (99%), and more than 80% had multiple injuries. None of them were independent in all BADL and IADL. Older groups were more dependent in IADL such as telephone use, drug management, financial management, and BADL such as walking on uneven surfaces, bed/chair transfer and using stairs. The functional status and activities' level differences between those aged younger than 50 years and those aged older than 50 years were significant (P<0.05). In the present study, all the IBWS were dependent in at least one ADL. Multiple physical injuries could be one of the main reasons for the dependency in this group. IBWS aged older than 50 years were considerably more dependent in their BADL and IADL than the younger group. It appears that starting the fifth decade of age in IBWS might cause some considerable decrease in their function. Training and individualized rehabilitation programs are warranted. © 2012 Japan Geriatrics Society.
38 CFR 10.33 - Determination of dependency.
Code of Federal Regulations, 2012 CFR
2012-07-01
... dependency. 10.33 Section 10.33 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.33 Determination of dependency. A determination of the existence of the alleged dependency will be made upon consideration of all facts relating to...
38 CFR 10.33 - Determination of dependency.
Code of Federal Regulations, 2013 CFR
2013-07-01
... dependency. 10.33 Section 10.33 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.33 Determination of dependency. A determination of the existence of the alleged dependency will be made upon consideration of all facts relating to...
38 CFR 10.33 - Determination of dependency.
Code of Federal Regulations, 2011 CFR
2011-07-01
... dependency. 10.33 Section 10.33 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.33 Determination of dependency. A determination of the existence of the alleged dependency will be made upon consideration of all facts relating to...
38 CFR 10.33 - Determination of dependency.
Code of Federal Regulations, 2010 CFR
2010-07-01
... dependency. 10.33 Section 10.33 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.33 Determination of dependency. A determination of the existence of the alleged dependency will be made upon consideration of all facts relating to...
38 CFR 10.33 - Determination of dependency.
Code of Federal Regulations, 2014 CFR
2014-07-01
... dependency. 10.33 Section 10.33 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.33 Determination of dependency. A determination of the existence of the alleged dependency will be made upon consideration of all facts relating to...
Epidemiology of substance abuse among migrants compared to native born population in primary care.
Qureshi, Adil; Garcia Campayo, Javier; Eiroa-Orosa, Francisco Jose; Sobradiel, Natalia; Collazos, Francisco; Febrel Bordejé, Mercedes; Roncero, Carlos; Andrés, Eva; Casas, Miguel
2014-01-01
Research in the United States tends to indicate that immigrants from most sociogeographic regions have considerably lower substance use disorder (SUD) rates than native born individuals. We aimed to analyze the differences between immigrants and native born population regarding substance abuse and dependence. This objective was approached using data from the ARACAT cross-sectional multicenter study in primary care settings of two different Spanish regions: Aragon and Catalonia. Three thousand six patients (1,503 immigrants randomly selected and 1,503 native born paired by age and gender) were interviewed using the Mini-International Neuropsychiatric Interview. Reported substance abuse and dependence were more prevalent in the native born population than in immigrants (alcohol abuse 5.1% vs. 2.6% p < .0001, alcohol dependence 3.3% vs. 2.6% n.s., other abuse 3.4% vs. .4% p < .0001, other dependence .5% vs. 4.0% p < .0001). Large differences were detected between different ethnic groups. Sociodemographic characteristics such as female gender, older age, higher level of education or stable housing (among others), were found to be protective against different SUDs. Immigrants have lower levels of alcohol and substance abuse, however, those that do consume show higher levels of both comorbid mental disorders and problematic alcohol/substance use. It would appear to be the case that issues specific to immigrant cultures, such as extreme stigmatization of substance and alcohol use, may serve to promote social marginalization and inhibit treatment access. © American Academy of Addiction Psychiatry.
Main Properties of Forbush Effects Related to High-Speed Streams from Coronal Holes
NASA Astrophysics Data System (ADS)
Melkumyan, A. A.; Belov, A. V.; Abunina, M. A.; Abunin, A. A.; Eroshenko, E. A.; Oleneva, V. A.; Yanke, V. G.
2018-03-01
The IZMIRAN database of Forbush effects and interplanetary disturbances was used to study features of the action of high-speed solar wind streams from coronal holes on cosmic rays. Three hundred and fifty Forbush effects created by coronal holes without other actions were distinguished. The mean values and distributions have been found for different characteristics of events from this group and compared with all Forbush effects and Forbush effects caused by coronal ejections. Despite the great differences in high-speed streams from coronal holes, this group turned out to be more compact and uniform as compared to events related to coronal ejections. Regression dependences and correlation relations between different parameters of events for the studied groups have been obtained. It has been shown that Forbush effects caused by coronal ejections depend considerably more strongly on the characteristics of interplanetary disturbances as compared to Forbush effects related to coronal holes. This suggests a significant difference between the modulation mechanisms of Forbush effects of different types and corroborates earlier conclusions based on indirect data.
Giacomini, M; Luft, H S; Robinson, J C
1995-01-01
This paper surveys recent health care reform debates and empirical evidence regarding the potential role for risk adjusters in addressing the problem of competitive risk segmentation under capitated financing. We discuss features of health plan markets affecting risk selection, methodological considerations in measuring it, and alternative approaches to financial correction for risk differentials. The appropriate approach to assessing risk differences between health plans depends upon the nature of market risk selection allowed under a given reform scenario. Because per capita costs depend on a health plan's population risk, efficiency, and quality of service, risk adjustment will most strongly promote efficiency in environments with commensurately strong incentives for quality care.
Structural materials issues for the next generation fission reactors
NASA Astrophysics Data System (ADS)
Chant, I.; Murty, K. L.
2010-09-01
Generation-IV reactor design concepts envisioned thus far cater to a common goal of providing safer, longer lasting, proliferation-resistant, and economically viable nuclear power plants. The foremost consideration in the successful development and deployment of Gen-W reactor systems is the performance and reliability issues involving structural materials for both in-core and out-of-core applications. The structural materials need to endure much higher temperatures, higher neutron doses, and extremely corrosive environments, which are beyond the experience of the current nuclear power plants. Materials under active consideration for use in different reactor components include various ferritic/martensitic steels, austenitic stainless steels, nickel-base superalloys, ceramics, composites, etc. This article addresses the material requirements for these advanced fission reactor types, specifically addressing structural materials issues depending on the specific application areas.
The B-dot Earth Average Magnetic Field
NASA Technical Reports Server (NTRS)
Capo-Lugo, Pedro A.; Rakoczy, John; Sanders, Devon
2013-01-01
The average Earth's magnetic field is solved with complex mathematical models based on mean square integral. Depending on the selection of the Earth magnetic model, the average Earth's magnetic field can have different solutions. This paper presents a simple technique that takes advantage of the damping effects of the b-dot controller and is not dependent of the Earth magnetic model; but it is dependent on the magnetic torquers of the satellite which is not taken into consideration in the known mathematical models. Also the solution of this new technique can be implemented so easily that the flight software can be updated during flight, and the control system can have current gains for the magnetic torquers. Finally, this technique is verified and validated using flight data from a satellite that it has been in orbit for three years.
Natural kinds in evolution and systematics: metaphysical and epistemological considerations.
Brigandt, Ingo
2009-06-01
Despite the traditional focus on metaphysical issues in discussions of natural kinds in biology, epistemological considerations are at least as important. By revisiting the debate as to whether taxa are kinds or individuals, I argue that both accounts are metaphysically compatible, but that one or the other approach can be pragmatically preferable depending on the epistemic context. Recent objections against construing species as homeostatic property cluster kinds are also addressed. The second part of the paper broadens the perspective by considering homologues as another example of natural kinds, comparing them with analogues as functionally defined kinds. Given that there are various types of natural kinds, I discuss the different theoretical purposes served by diverse kind concepts, suggesting that there is no clear-cut distinction between natural kinds and other kinds, such as functional kinds. Rather than attempting to offer a unique metaphysical account of 'natural' kind, a more fruitful approach consists in the epistemological study of how different natural kind concepts are employed in scientific reasoning.
NASA Astrophysics Data System (ADS)
Tan, Yanglan; Polfer, Nicolas C.
2015-02-01
Carbohydrates and their derivatives play important roles in biological systems, but their isomeric heterogeneity also presents a considerable challenge for analytical techniques. Here, a stepwise approach using infrared multiple-photon dissociation (IRMPD) via a tunable CO2 laser (9.2-10.7 μm) was employed to characterize isomeric variants of glucose-based trisaccharides. After the deprotonated trisaccharides were trapped and fragmented to disaccharide C2 fragments in a Fourier transform ion cyclotron resonance (FTICR) cell, a further variable-wavelength infrared irradiation of the C2 ion produced wavelength-dependent dissociation patterns that are represented as heat maps. The photodissociation patterns of these C2 fragments are shown to be strikingly similar to the photodissociation patterns of disaccharides with identical glycosidic bonds. Conversely, the photodissociation patterns of different glycosidic linkages exhibit considerable differences. On the basis of these results, the linkage position and anomericity of glycosidic bonds of disaccharide units in trisaccharides can be systematically differentiated and identified, providing a promising approach to characterize the structures of isomeric oligosaccharides.
1989-06-01
thousands of acres of wetlands have been lost as a result of rapid coastal development. In view of their important ecological functions, it becomes... ecological roles: 1. trap sediment and stabilize bottom sediments; 2. carry on basic productivity that, in the eastern gulf, may considerably exceed the...be different, depending on the ecological attributes of the replacement habitat. This would result in no net loss of total habitat value, but might
The importance of mechanisms for the evolution of cooperation
van den Berg, Pieter; Weissing, Franz J.
2015-01-01
Studies aimed at explaining the evolution of phenotypic traits have often solely focused on fitness considerations, ignoring underlying mechanisms. In recent years, there has been an increasing call for integrating mechanistic perspectives in evolutionary considerations, but it is not clear whether and how mechanisms affect the course and outcome of evolution. To study this, we compare four mechanistic implementations of two well-studied models for the evolution of cooperation, the Iterated Prisoner's Dilemma (IPD) game and the Iterated Snowdrift (ISD) game. Behavioural strategies are either implemented by a 1 : 1 genotype–phenotype mapping or by a simple neural network. Moreover, we consider two different scenarios for the effect of mutations. The same set of strategies is feasible in all four implementations, but the probability that a given strategy arises owing to mutation is largely dependent on the behavioural and genetic architecture. Our individual-based simulations show that this has major implications for the evolutionary outcome. In the ISD, different evolutionarily stable strategies are predominant in the four implementations, while in the IPD each implementation creates a characteristic dynamical pattern. As a consequence, the evolved average level of cooperation is also strongly dependent on the underlying mechanism. We argue that our findings are of general relevance for the evolution of social behaviour, pleading for the integration of a mechanistic perspective in models of social evolution. PMID:26246554
The Fungal Frontier: A Comparative Analysis of Methods Used in the Study of the Human Gut Mycobiome
Huseyin, Chloe E.; Rubio, Raul Cabrera; O’Sullivan, Orla; Cotter, Paul D.; Scanlan, Pauline D.
2017-01-01
The human gut is host to a diverse range of fungal species, collectively referred to as the gut “mycobiome”. The gut mycobiome is emerging as an area of considerable research interest due to the potential roles of these fungi in human health and disease. However, there is no consensus as to what the best or most suitable methodologies available are with respect to characterizing the human gut mycobiome. The aim of this study is to provide a comparative analysis of several previously published mycobiome-specific culture-dependent and -independent methodologies, including choice of culture media, incubation conditions (aerobic versus anaerobic), DNA extraction method, primer set and freezing of fecal samples to assess their relative merits and suitability for gut mycobiome analysis. There was no significant effect of media type or aeration on culture-dependent results. However, freezing was found to have a significant effect on fungal viability, with significantly lower fungal numbers recovered from frozen samples. DNA extraction method had a significant effect on DNA yield and quality. However, freezing and extraction method did not have any impact on either α or β diversity. There was also considerable variation in the ability of different fungal-specific primer sets to generate PCR products for subsequent sequence analysis. Through this investigation two DNA extraction methods and one primer set was identified which facilitated the analysis of the mycobiome for all samples in this study. Ultimately, a diverse range of fungal species were recovered using both approaches, with Candida and Saccharomyces identified as the most common fungal species recovered using culture-dependent and culture-independent methods, respectively. As has been apparent from ecological surveys of the bacterial fraction of the gut microbiota, the use of different methodologies can also impact on our understanding of gut mycobiome composition and therefore requires careful consideration. Future research into the gut mycobiome needs to adopt a common strategy to minimize potentially confounding effects of methodological choice and to facilitate comparative analysis of datasets. PMID:28824566
Application of in Vitro Biotransformation Data and ...
The adverse biological effects of toxic substances are dependent upon the exposure concentration and the duration of exposure. Pharmacokinetic models can quantitatively relate the external concentration of a toxicant in the environment to the internal dose of the toxicant in the target tissues of an exposed organism. The exposure concentration of a toxic substance is usually not the same as the concentration of the active form of the toxicant that reaches the target tissues following absorption, distribution, and biotransformation of the parent toxicant. Biotransformation modulates the biological activity of chemicals through bioactivation and detoxication pathways. Many toxicants require biotransformation to exert their adverse biological effects. Considerable species differences in biotransformation and other pharmacokinetic processes can make extrapolation of toxicity data from laboratory animals to humans problematic. Additionally, interindividual differences in biotransformation among human populations with diverse genetics and lifestyles can lead to considerable variability in the bioactivation of toxic chemicals. Compartmental pharmacokinetic models of animals and humans are needed to understand the quantitative relationships between chemical exposure and target tissue dose as well as animal to human differences and interindividual differences in human populations. The data-based compartmental pharmacokinetic models widely used in clinical pharmacology ha
Variation in reaction norms: Statistical considerations and biological interpretation.
Morrissey, Michael B; Liefting, Maartje
2016-09-01
Analysis of reaction norms, the functions by which the phenotype produced by a given genotype depends on the environment, is critical to studying many aspects of phenotypic evolution. Different techniques are available for quantifying different aspects of reaction norm variation. We examine what biological inferences can be drawn from some of the more readily applicable analyses for studying reaction norms. We adopt a strongly biologically motivated view, but draw on statistical theory to highlight strengths and drawbacks of different techniques. In particular, consideration of some formal statistical theory leads to revision of some recently, and forcefully, advocated opinions on reaction norm analysis. We clarify what simple analysis of the slope between mean phenotype in two environments can tell us about reaction norms, explore the conditions under which polynomial regression can provide robust inferences about reaction norm shape, and explore how different existing approaches may be used to draw inferences about variation in reaction norm shape. We show how mixed model-based approaches can provide more robust inferences than more commonly used multistep statistical approaches, and derive new metrics of the relative importance of variation in reaction norm intercepts, slopes, and curvatures. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
Note on measuring electronic stopping of slow ions
NASA Astrophysics Data System (ADS)
Sigmund, P.; Schinner, A.
2017-11-01
Extracting stopping cross sections from energy-loss measurements requires careful consideration of the experimental geometry. Standard procedures for separating nuclear from electronic stopping treat electronic energy loss as a friction force, ignoring its dependence on impact parameter. In the present study we find that incorporating this dependence has a major effect on measured stopping cross sections, in particular for light ions at low beam energies. Calculations have been made for transmission geometry, nuclear interactions being quantified by Bohr-Williams theory of multiple scattering on the basis of a Thomas-Fermi-Molière potential, whereas electronic interactions are characterized by Firsov theory or PASS code. Differences between the full and the restricted stopping cross section depend on target thickness and opening angle of the detector and need to be taken into account in comparisons with theory as well as in applications of stopping data. It follows that the reciprocity principle can be violated when checked on restricted instead of full electronic stopping cross sections. Finally, we assert that a seeming gas-solid difference in stopping of low-energy ions is actually a metal-insulator difference. In comparisons with experimental results we mostly consider proton data, where nuclear stopping is only a minor perturbation.
Importance of perspective in economic analyses of cancer screening decisions.
Mansley, E C; McKenna, M T
2001-10-06
As the fifth, and final, report in this Lancet series on health economics, we discuss how economic analyses in public health, with cancer screening as the example, differ depending on the perspective taken. We identify nine different, but related, decision makers at various levels, from the individual patient to society as a whole, and discuss how their different viewpoints affect their ultimate decisions. Central to our discussion is the identification of seven distinct components of perspective, each potentially important in the screening decision. In many fields of healthcare, decisions about the use of resources, such as time, wealth, or energy, are made by weighing up the positive and negative consequences of the alternatives under consideration and are thus based on an economic analysis of the situation (although sometimes this process is subconscious). For simplicity, we restrict our report to the effect of perspective on cancer screening decisions and show how the costs (negative consequences) and benefits (positive consequences) vary depending on the decision maker.
Terada, Takatoshi; Ohtsubo, Toshiro; Iwao, Yasunori; Noguchi, Shuji; Itai, Shigeru
2017-01-01
The purpose of this study was to develop a deeper understanding of the key physicochemical parameters involved in the release profiles of microsphere-encapsulated agrochemicals at different temperatures. Microspheres consisting of different polyurethanes (PUs) were prepared using our previously reported solventless microencapsulation technique. Notably, these microspheres exhibited considerable differences in their thermodynamic characteristics, including their glass transition temperature (T g ), extrapolated onset temperature (T o ) and extrapolated end temperature (T e ). At test temperatures below the T o of the PU, only 5-10% of the agrochemical was rapidly released from the microspheres within 1 d, and none was released thereafter. However, at test temperatures above the T o of the PU, the rate of agrochemical release gradually increased with increasing temperatures, and the rate of release from the microspheres was dependent on the composition of the PU. Taken together, these results show that the release profiles of the microspheres were dependent on their thermodynamic characteristics and changes in their PU composition.
Using game theory to analyze green stormwater infrastructure implementation policies
NASA Astrophysics Data System (ADS)
William, R. K.; Garg, J.; Stillwell, A. S.
2017-12-01
While green stormwater infrastructure is a useful approach in addressing multiple challenges facing the urban environment, little consensus exists on how to best incentivize its adoption by private landowners. Game theory, a field of study designed to model conflict and cooperation between two or more agents, is well-suited to address this policy question. We used a cooperative game theory framework to analyze the impacts of three different policy approaches frequently used to incentivize the uptake of green infrastructure by private landowners: municipal regulation, direct grants, and stormwater fees. The results indicate that municipal regulation leads to the greatest environmental benefits; however, the choice of "best" regulatory approach is dependent on a variety of different factors including political and financial considerations. Policy impacts are also highly dependent on agents' spatial positions within the stormwater network. This finding leads to important questions of social equity and environmental justice.
Odour and ammonia emissions from intensive poultry units in Ireland.
Hayes, E T; Curran, T P; Dodd, V A
2006-05-01
Odour and ammonia emissions were measured from three broiler, two layer and two turkey houses in Ireland. The broiler units gave a large range of odour and ammonia emission rates depending on the age of the birds and the season. A considerable variation between the odour and ammonia emission rates was evident for the two layer units which may have been due to the different manure handling systems utilised in the houses. There was relatively little difference in the odour and ammonia emissions from the two turkey houses. As a precautionary principle, odour emission rates utilised in atmospheric dispersion models should use the maximum values for broilers and turkeys (1.22 and 10.5 ou(E) s(-1) bird(-1) respectively) and the mean value for the layers depending on the manure handling system used (0.47 or 1.35 ou(E) s(-1) bird(-1)).
Parallelization of implicit finite difference schemes in computational fluid dynamics
NASA Technical Reports Server (NTRS)
Decker, Naomi H.; Naik, Vijay K.; Nicoules, Michel
1990-01-01
Implicit finite difference schemes are often the preferred numerical schemes in computational fluid dynamics, requiring less stringent stability bounds than the explicit schemes. Each iteration in an implicit scheme involves global data dependencies in the form of second and higher order recurrences. Efficient parallel implementations of such iterative methods are considerably more difficult and non-intuitive. The parallelization of the implicit schemes that are used for solving the Euler and the thin layer Navier-Stokes equations and that require inversions of large linear systems in the form of block tri-diagonal and/or block penta-diagonal matrices is discussed. Three-dimensional cases are emphasized and schemes that minimize the total execution time are presented. Partitioning and scheduling schemes for alleviating the effects of the global data dependencies are described. An analysis of the communication and the computation aspects of these methods is presented. The effect of the boundary conditions on the parallel schemes is also discussed.
Lessons Learned from Dependency Usage in HERA: Implications for THERP-Related HRA Methods
DOE Office of Scientific and Technical Information (OSTI.GOV)
April M. Whaley; Ronald L. Boring; Harold S. Blackman
Dependency occurs when the probability of success or failure on one action changes the probability of success or failure on a subsequent action. Dependency may serve as a modifier on the human error probabilities (HEPs) for successive actions in human reliability analysis (HRA) models. Discretion should be employed when determining whether or not a dependency calculation is warranted: dependency should not be assigned without strongly grounded reasons. Human reliability analysts may sometimes assign dependency in cases where it is unwarranted. This inappropriate assignment is attributed to a lack of clear guidance to encompass the range of scenarios human reliability analystsmore » are addressing. Inappropriate assignment of dependency produces inappropriately elevated HEP values. Lessons learned about dependency usage in the Human Event Repository and Analysis (HERA) system may provide clarification and guidance for analysts using first-generation HRA methods. This paper presents the HERA approach to dependency assessment and discusses considerations for dependency usage in HRA, including the cognitive basis for dependency, direction for determining when dependency should be assessed, considerations for determining the dependency level, temporal issues to consider when assessing dependency, (e.g., considering task sequence versus overall event sequence, and dependency over long periods of time), and diagnosis and action influences on dependency.« less
Schäffer, Beat; Pieren, Reto; Mendolia, Franco; Basner, Mathias; Brink, Mark
2017-05-01
Noise exposure-response relationships are used to estimate the effects of noise on individuals or a population. Such relationships may be derived from independent or repeated binary observations, and modeled by different statistical methods. Depending on the method by which they were established, their application in population risk assessment or estimation of individual responses may yield different results, i.e., predict "weaker" or "stronger" effects. As far as the present body of literature on noise effect studies is concerned, however, the underlying statistical methodology to establish exposure-response relationships has not always been paid sufficient attention. This paper gives an overview on two statistical approaches (subject-specific and population-averaged logistic regression analysis) to establish noise exposure-response relationships from repeated binary observations, and their appropriate applications. The considerations are illustrated with data from three noise effect studies, estimating also the magnitude of differences in results when applying exposure-response relationships derived from the two statistical approaches. Depending on the underlying data set and the probability range of the binary variable it covers, the two approaches yield similar to very different results. The adequate choice of a specific statistical approach and its application in subsequent studies, both depending on the research question, are therefore crucial.
Dependence on Tobacco and Nicotine Products: A Case for Product-Specific Assessment
Eissenberg, Thomas
2012-01-01
The International Classification of Diseases and the Diagnostic and Statistical Manual for diagnosing tobacco/nicotine dependence emphasize the dependence-producing drug nicotine. These diagnostic tools have been challenged on grounds of poor predictive validity, and they do not differentiate across various forms of nicotine-containing products. In fact, nicotine-containing products (e.g., tobacco cigarettes, smokeless tobacco [ST], waterpipe, electronic cigarettes [ECIGs], and nicotine replacement [NR] products) have very different characteristics both in terms of sensory and behavioral involvement and also in pharmacokinetic and pharmacodynamic effects. For example, a cigarette and a nicotine patch are very different on almost every one of these dimensions. When ability to stop using a nicotine/tobacco product is used as a criterion for dependence, success rates vary considerably across products: Tobacco cigarette cessation is more difficult than ST cessation that in turn is more difficult than NR product cessation. Based on these results, we hypothesize that there is a continuum of dependence as much as there is a continuum of harm, with tobacco cigarettes and NR products on opposite ends of both continua and other products (waterpipe and ECIGs) somewhere in between. In order to capture more precisely the dependence produced by both nicotine and its administration forms, product-specific instruments may be required. The pros and cons of this approach are discussed. PMID:22459798
Pornography and teenagers: the importance of individual differences.
Malamuth, Neil; Huppin, Mark
2005-06-01
This article focuses on the effects of exposure to pornography on teenagers, particularly males, and concentrates on sexually aggressive outcomes and on the characteristics of the individual as crucial in determining whether pornography consumption may or may not lead to sexually aggressive outcomes. In future work, it is important not to use an overly simplistic lens of focus in which pornography exposure is seen as generally harmful or not. Depending on particular constellations of personality characteristics, the effects of pornography may differ considerably among different teenagers as well as within different cultures. The research suggests that particular concerns may be needed for those who are highly frequent consumers of pornography, those who seek out sexually violent content, and those who also have other risk factors.
Memory Management of Multimedia Services in Smart Homes
NASA Astrophysics Data System (ADS)
Kamel, Ibrahim; Muhaureq, Sanaa A.
Nowadays there is a wide spectrum of applications that run in smart home environments. Consequently, home gateway, which is a central component in the smart home, must manage many applications despite limited memory resources. OSGi is a middleware standard for home gateways. OSGi models services as dependent components. Moreover, these applications might differ in their importance. Services collaborate and complement each other to achieve the required results. This paper addresses the following problem: given a home gateway that hosts several applications with different priorities and arbitrary dependencies among them. When the gateway runs out of memory, which application or service will be stopped or kicked out of memory to start a new service. Note that stopping a given service means that all the services that depend on it will be stopped too. Because of the service dependencies, traditional memory management techniques, in the operating system literatures might not be efficient. Our goal is to stop the least important and the least number of services. The paper presents a novel algorithm for home gateway memory management. The proposed algorithm takes into consideration the priority of the application and dependencies between different services, in addition to the amount of memory occupied by each service. We implement the proposed algorithm and performed many experiments to evaluate its performance and execution time. The proposed algorithm is implemented as a part of the OSGi framework (Open Service Gateway initiative). We used best fit and worst fit as yardstick to show the effectiveness of the proposed algorithm.
NASA Astrophysics Data System (ADS)
Nikolaev, M. A.; Klapdor-Kleingrothaus, H. V.
1993-06-01
We present calculations of the nuclear from factors for spin-dependent elastic scattering of dark matter WIMPs from123Te and131Xe isotopes, proposed to be used for dark matter detection. A method based on the theory of finite Fermi systems was used to describe the reduction of the single-particle spin-dependent matrix elements in the nuclear medium. Nucleon single-particle states were calculated in a realistic shell model potential; pairing effects were treated within the BCS model. The coupling of the lowest single-particle levels in123Te to collective 2+ excitations of the core was taken into account phenomenologically. The calculated nuclear form factors are considerably less then the single-particle ones for low momentum transfer. At high momentum transfer some dynamical amplification takes place due to the pion exchange term in the effective nuclear interaction. But as the momentum transfer increases, the difference disappears, the momentum transfer increases and the quenching effect disappears. The shape of the nuclear form factor for the131Xe isotope differs from the one obtained using an oscillator basis.
NASA Astrophysics Data System (ADS)
Wati, Elvis; Meukam, Pierre; Damfeu, Jean Claude
2017-12-01
Uninsulated concrete block walls commonly found in tropical region have to be retrofitted to save energy. The thickness of insulation layer used can be reduced with the help of modified laterite based bricks layer (with the considerably lower thermal conductivity than that of concrete block layer) during the retrofit building fabrics. The aim of this study is to determine the optimum location and distribution of different materials. The investigation is carried out under steady periodic conditions under the climatic conditions of Garoua in Cameroon using a Simulink model constructed from H-Tools (the library of Simulink models). Results showed that for the continuous air-conditioned space, the best wall configuration from the maximum time lag, minimum decrement factor and peak cooling transmission load perspective, is dividing the insulation layer into two layers and placing one at the exterior surface and the other layer between the two different massive layers with the modified laterite based bricks layer at the interior surface. For intermittent cooling space, the best wall configuration from the minimum energy consumption depends on total insulation thickness. For the total insulation thickness less than 8 cm approximately, the best wall configuration is placing the half layer of insulation material at the interior surface and the other half between the two different massive layers with the modified earthen material at the exterior surface. Results also showed that, the optimum insulation thickness calculated from the yearly cooling transmission (estimated only during the occupied period) and some economic considerations slightly depends on the location of that insulation.
On-off intermittency and intermingledlike basins in a granular medium.
Schmick, Malte; Goles, Eric; Markus, Mario
2002-12-01
Molecular dynamic simulations of a medium consisting of disks in a periodically tilted box yield two dynamic modes differing considerably in the total potential and kinetic energies of the disks. Depending on parameters, these modes display the following features: (i) hysteresis (coexistence of the two modes in phase space); (ii) intermingledlike basins of attraction (uncertainty exponent indistinguishable from zero); (iii) two-state on-off intermittency; and (iv) bimodal velocity distributions. Bifurcations are defined by a cross-shaped phase diagram.
Automated Diagnosis Coding with Combined Text Representations.
Berndorfer, Stefan; Henriksson, Aron
2017-01-01
Automated diagnosis coding can be provided efficiently by learning predictive models from historical data; however, discriminating between thousands of codes while allowing a variable number of codes to be assigned is extremely difficult. Here, we explore various text representations and classification models for assigning ICD-9 codes to discharge summaries in MIMIC-III. It is shown that the relative effectiveness of the investigated representations depends on the frequency of the diagnosis code under consideration and that the best performance is obtained by combining models built using different representations.
Indispensable finite time corrections for Fokker-Planck equations from time series data.
Ragwitz, M; Kantz, H
2001-12-17
The reconstruction of Fokker-Planck equations from observed time series data suffers strongly from finite sampling rates. We show that previously published results are degraded considerably by such effects. We present correction terms which yield a robust estimation of the diffusion terms, together with a novel method for one-dimensional problems. We apply these methods to time series data of local surface wind velocities, where the dependence of the diffusion constant on the state variable shows a different behavior than previously suggested.
Transverse Motion of a Particle with an Oscillating Charge and Variable Mass in a Magnetic Field
NASA Astrophysics Data System (ADS)
Alisultanov, Z. Z.; Ragimkhanov, G. B.
2018-03-01
The problem of motion of a particle with an oscillating electric charge and variable mass in an uniform magnetic field has been solved. Three laws of mass variation have been considered: linear growth, oscillations, and stepwise growth. Analytical expressions for the particle velocity at different time dependences of the particle mass are obtained. It is established that simultaneous consideration of changes in the mass and charge leads to a significant change in the particle trajectory.
Epileptogenicity and pathology - Under consideration of ablative approaches.
Stefan, H; Schmitt, F C
2018-05-01
Besides resective epilepsy surgery, minimally invasive ablation using new diagnostic and therapeutic techniques recently became available. Optimal diagnostic approaches for these treatment options are discussed. The pathophysiology of epileptogenic networks differs depending on the lesion-types and location, requiring a differential use of non-invasive or invasive functional studies. In addition to the definition of epileptogenic zones, a challenge for pre-surgical investigation is the determination of three-dimensional epileptic networks to be removed. Copyright © 2018. Published by Elsevier B.V.
Layer-switching cost and optimality in information spreading on multiplex networks
Min, Byungjoon; Gwak, Sang-Hwan; Lee, Nanoom; Goh, K. -I.
2016-01-01
We study a model of information spreading on multiplex networks, in which agents interact through multiple interaction channels (layers), say online vs. offline communication layers, subject to layer-switching cost for transmissions across different interaction layers. The model is characterized by the layer-wise path-dependent transmissibility over a contact, that is dynamically determined dependently on both incoming and outgoing transmission layers. We formulate an analytical framework to deal with such path-dependent transmissibility and demonstrate the nontrivial interplay between the multiplexity and spreading dynamics, including optimality. It is shown that the epidemic threshold and prevalence respond to the layer-switching cost non-monotonically and that the optimal conditions can change in abrupt non-analytic ways, depending also on the densities of network layers and the type of seed infections. Our results elucidate the essential role of multiplexity that its explicit consideration should be crucial for realistic modeling and prediction of spreading phenomena on multiplex social networks in an era of ever-diversifying social interaction layers. PMID:26887527
Gas-film coefficients for streams
Rathbun, R.E.; Tai, D.Y.
1983-01-01
Equations for predicting the gas-film coefficient for the volatilization of organic solutes from streams are developed. The film coefficient is a function of windspeed and water temperature. The dependence of the coefficient on windspeed is determined from published information on the evaporation of water from a canal. The dependence of the coefficient on temperature is determined from laboratory studies on the evaporation of water. Procedures for adjusting the coefficients for different organic solutes are based on the molecular diffusion coefficient and the molecular weight. The molecular weight procedure is easiest to use because of the availability of molecular weights. However, the theoretical basis of the procedure is questionable. The diffusion coefficient procedure is supported by considerable data. Questions, however, remain regarding the exact dependence of the film coefficint on the diffusion coefficient. It is suggested that the diffusion coefficient procedure with a 0.68-power dependence be used when precise estimate of the gas-film coefficient are needed and that the molecular weight procedure be used when only approximate estimates are needed.
NASA Astrophysics Data System (ADS)
Ding, Anxin; Li, Shuxin; Wang, Jihui; Ni, Aiqing; Sun, Liangliang; Chang, Lei
2016-10-01
In this paper, the corner spring-in angles of AS4/8552 L-shaped composite profiles with different thicknesses are predicted using path-dependent constitutive law with the consideration of material properties variation due to phase change during curing. The prediction accuracy mainly depends on the properties in the rubbery and glassy states obtained by homogenization method rather than experimental measurements. Both analytical and finite element (FE) homogenization methods are applied to predict the overall properties of AS4/8552 composite. The effect of fiber volume fraction on the properties is investigated for both rubbery and glassy states using both methods. And the predicted results are compared with experimental measurements for the glassy state. Good agreement is achieved between the predicted results and available experimental data, showing the reliability of the homogenization method. Furthermore, the corner spring-in angles of L-shaped composite profiles are measured experimentally and the reliability of path-dependent constitutive law is validated as well as the properties prediction by FE homogenization method.
Fischer, Manuel; Horn, Sebastian; Belkacemi, Anouar; Kojer, Kerstin; Petrungaro, Carmelina; Habich, Markus; Ali, Muna; Küttner, Victoria; Bien, Melanie; Kauff, Frank; Dengjel, Jörn; Herrmann, Johannes M.; Riemer, Jan
2013-01-01
Oxidation of cysteine residues to disulfides drives import of many proteins into the intermembrane space of mitochondria. Recent studies in yeast unraveled the basic principles of mitochondrial protein oxidation, but the kinetics under physiological conditions is unknown. We developed assays to follow protein oxidation in living mammalian cells, which reveal that import and oxidative folding of proteins are kinetically and functionally coupled and depend on the oxidoreductase Mia40, the sulfhydryl oxidase augmenter of liver regeneration (ALR), and the intracellular glutathione pool. Kinetics of substrate oxidation depends on the amount of Mia40 and requires tightly balanced amounts of ALR. Mia40-dependent import of Cox19 in human cells depends on the inner membrane potential. Our observations reveal considerable differences in the velocities of mitochondrial import pathways: whereas preproteins with bipartite targeting sequences are imported within seconds, substrates of Mia40 remain in the cytosol for several minutes and apparently escape premature degradation and oxidation. PMID:23676665
Thompson, Kelly; Zhang, Jianying; Zhang, Chunlong
2011-08-01
Effluents from sewage treatment plants (STPs) are known to contain residual micro-contaminants including endocrine disrupting chemicals (EDCs) despite the utilization of various removal processes. Temperature alters the efficacy of removal processes; however, experimental measurements of EDC removal at various temperatures are limited. Extrapolation of EDC behavior over a wide temperature range is possible using available physicochemical property data followed by the correction of temperature dependency. A level II fugacity-based STP model was employed by inputting parameters obtained from the literature and estimated by the US EPA's Estimations Programs Interface (EPI) including EPI's BIOWIN for temperature-dependent biodegradation half-lives. EDC removals in a three-stage activated sludge system were modeled under various temperatures and hydraulic retention times (HRTs) for representative compounds of various properties. Sensitivity analysis indicates that temperature plays a significant role in the model outcomes. Increasing temperature considerably enhances the removal of β-estradiol, ethinyestradiol, bisphenol, phenol, and tetrachloroethylene, but not testosterone with the highest biodegradation rate. The shortcomings of BIOWIN were mitigated by the correction of highly temperature-dependent biodegradation rates using the Arrhenius equation. The model predicts well the effects of operating temperature and HRTs on the removal via volatilization, adsorption, and biodegradation. The model also reveals that an impractically long HRT is needed to achieve a high EDC removal. The STP model along with temperature corrections is able to provide some useful insight into the different patterns of STP performance, and useful operational considerations relevant to EDC removal at winter low temperatures. Copyright © 2011 Elsevier Ltd. All rights reserved.
Behavioral assays with mouse models of Alzheimer’s disease: practical considerations and guidelines
Puzzo, Daniela; Lee, Linda; Palmeri, Agostino; Calabrese, Giorgio; Arancio, Ottavio
2014-01-01
In Alzheimer’s disease (AD) basic research and drug discovery, mouse models are essential resources for uncovering biological mechanisms, validating molecular targets and screening potential compounds. Both transgenic and non-genetically modified mouse models enable access to different types of AD-like pathology in vivo. Although there is a wealth of genetic and biochemical studies on proposed AD pathogenic pathways, as a disease that centrally features cognitive failure, the ultimate readout for any interventions should be measures of learning and memory. This is particularly important given the lack of knowledge on disease etiology – assessment by cognitive assays offers the advantage of targeting relevant memory systems without requiring assumptions about pathogenesis. A multitude of behavioral assays are available for assessing cognitive functioning in mouse models, including ones specific for hippocampal-dependent learning and memory. Here we review the basics of available transgenic and non-transgenic AD mouse models and detail three well-established behavioral tasks commonly used for testing hippocampal-dependent cognition in mice – contextual fear conditioning, radial arm water maze and Morris water maze. In particular, we discuss the practical considerations, requirements and caveats of these behavioral testing paradigms. PMID:24462904
Choice of recall period for patient-reported outcome (PRO) measures: criteria for consideration.
Norquist, Josephine M; Girman, Cynthia; Fehnel, Sheri; DeMuro-Mercon, Carla; Santanello, Nancy
2012-08-01
Understand the choice of recall period for PRO measures based on intended use, characteristics of the disease, treatment, and attributes of studies. Current practice and considerations were reviewed within several disease areas (overactive bladder, menopausal hot flashes, niacin-induced flushing, osteoarthritis pain, irritable bowel symptoms, benign prostatic hyperplasia, and alopecia). Rationales were identified for using different recall periods, including event-driven (immediate), daily, up to weekly, and longer than weekly. This work demonstrates that (1) recall depends on what the PRO measure captures, its intended use, and attributes of the disease and study; (2) within the same disease area, recall can vary depending on the concept or phenomenon of interest; (3) recall must consider patient burden and their ability to easily and accurately recall the information requested; and (4) recall must be consistent with the duration of the trial and the scheduled clinic visits. Shorter recall periods may underestimate symptom burden when symptoms have diurnal or day-to-day fluctuation and may place undue burden on patients. On the other hand, recall intervals that are too long may either over- or underestimate the health state. Therefore, appropriate criteria should be considered given attributes of the disease when selecting an adequate recall period.
Dependence of hydrogen arcjet operation on electrode geometry
NASA Technical Reports Server (NTRS)
Pencil, Eric J.; Sankovic, John M.; Sarmiento, Charles J.; Hamley, John A.
1992-01-01
The dependence of 2 kW hydrogen arcjet performance on cathode to anode electrode spacing was evaluated at specific impulses of 900 and 1000 s. Less than 2 absolute percent change in efficiency was measured for the spacings tested which did not repeat the 14 absolute percent variation reported in earlier work with similar electrode designs. A different nozzle configuration was used to quantify the variation in hydrogen arcjet performance over an extended range of electrode spacing. Electrode gap variation resulted in less than 3 absolute percent change in efficiency. These null results suggested that electrode spacing is decoupled from hydrogen arcjet performance considerations over the ranges tested. Initial studies were conducted on hydrogen arcjet ignition. The dependence of breakdown voltage on mass flow rate and hydrogen arcjet ignition on rates of pulse repetition and pulse voltage rise were also included for comparison with previous results obtained using simulated hydrazine.
Kuhlmey, J; Lautsch, E
1980-01-01
In our 2. information on the investigation of the need for cultural entertainments of inhabitants in geriatric nursing homes we tested the influence of the factors age, sex, kind of work and during of stay in the geriatric nursing home singly and successively for each single indicator of this complex need. In this 3. information the influence of this four factors was investigated in these contradictory dependency on the indicators under synchronous consideration of their contradictory dependency. The contradictory dependency of the factors was presented by typisation (cluster analysis). As a result of the cluster analysis same classes arose--similar disposed inhabitants belong to same classes. The average coinage in this classes was obtained and differences were analysed by statistical methods multidimensional analysis of variance and analysis of discriminance).
NASA Astrophysics Data System (ADS)
Park, DaeKil
2018-06-01
The dynamics of entanglement and uncertainty relation is explored by solving the time-dependent Schrödinger equation for coupled harmonic oscillator system analytically when the angular frequencies and coupling constant are arbitrarily time dependent. We derive the spectral and Schmidt decompositions for vacuum solution. Using the decompositions, we derive the analytical expressions for von Neumann and Rényi entropies. Making use of Wigner distribution function defined in phase space, we derive the time dependence of position-momentum uncertainty relations. To show the dynamics of entanglement and uncertainty relation graphically, we introduce two toy models and one realistic quenched model. While the dynamics can be conjectured by simple consideration in the toy models, the dynamics in the realistic quenched model is somewhat different from that in the toy models. In particular, the dynamics of entanglement exhibits similar pattern to dynamics of uncertainty parameter in the realistic quenched model.
Lonsdorf, Tina B; Haaker, Jan; Schümann, Dirk; Sommer, Tobias; Bayer, Janine; Brassen, Stefanie; Bunzeck, Nico; Gamer, Matthias; Kalisch, Raffael
2015-11-01
Anxiety disorders are more prevalent in women than in men. Despite this sexual dimorphism, most experimental studies are conducted in male participants and studies focusing on sex differences are sparse. In addition, the role of hormonal contraceptives and menstrual cycle phase in fear conditioning and extinction processes remain largely unknown. We investigated sex differences in context-dependent fear acquisition and extinction (day 1) and their retrieval/expression (day 2). Skin conductance responses (SCRs), fear and unconditioned stimulus expectancy ratings were obtained. We included 377 individuals (261 women) in our study. Robust sex differences were observed in all dependent measures. Women generally displayed higher subjective ratings but smaller SCRs than men and showed reduced excitatory/inhibitory conditioned stimulus (CS+/CS-) discrimination in all dependent measures. Furthermore, women using hormonal contraceptives showed reduced SCR CS discrimination on day 2 than men and free-cycling women, while menstrual cycle phase had no effect. Possible limitations include the simultaneous testing of up to 4 participants in cubicles, which might have introduced a social component, and not assessing postexperimental contingency awareness. The response pattern in women shows striking similarity to previously reported sex differences in patients with anxiety. Our results suggest that pronounced deficits in associative discrimination learning and subjective expression of safety information (CS- responses) might underlie higher prevalence and higher symptom rates seen in women with anxiety disorders. The data call for consideration of biological sex and hormonal contraceptive use in future studies and may suggest that targeting inhibitory learning during therapy might aid precision medicine.
Null but not void: considerations for hypothesis testing.
Shaw, Pamela A; Proschan, Michael A
2013-01-30
Standard statistical theory teaches us that once the null and alternative hypotheses have been defined for a parameter, the choice of the statistical test is clear. Standard theory does not teach us how to choose the null or alternative hypothesis appropriate to the scientific question of interest. Neither does it tell us that in some cases, depending on which alternatives are realistic, we may want to define our null hypothesis differently. Problems in statistical practice are frequently not as pristinely summarized as the classic theory in our textbooks. In this article, we present examples in statistical hypothesis testing in which seemingly simple choices are in fact rich with nuance that, when given full consideration, make the choice of the right hypothesis test much less straightforward. Published 2012. This article is a US Government work and is in the public domain in the USA.
Biodiversity hotspots house most undiscovered plant species.
Joppa, Lucas N; Roberts, David L; Myers, Norman; Pimm, Stuart L
2011-08-09
For most organisms, the number of described species considerably underestimates how many exist. This is itself a problem and causes secondary complications given present high rates of species extinction. Known numbers of flowering plants form the basis of biodiversity "hotspots"--places where high levels of endemism and habitat loss coincide to produce high extinction rates. How different would conservation priorities be if the catalog were complete? Approximately 15% more species of flowering plant are likely still undiscovered. They are almost certainly rare, and depending on where they live, suffer high risks of extinction from habitat loss and global climate disruption. By using a model that incorporates taxonomic effort over time, regions predicted to contain large numbers of undiscovered species are already conservation priorities. Our results leave global conservation priorities more or less intact, but suggest considerably higher levels of species imperilment than previously acknowledged.
Pathrose, Bini; Nampoori, V P N; Radhakrishnan, P; Sahira, H; Mujeeb, A
2015-05-01
In the present work dual beam thermal lens technique is used for studying the solvent dependency on the quantum efficiency of a novel dye used for biomedical applications. The role of solvent in the absolute fluorescence quantum yield of 4-[(4-Aminophenyl)-(4-imino-1-cyclohexa-2, 5- dienylidene) methyl] aniline hydrochloride is studied using thermal lens technique. It is observed that the variation in solvents and its concentration results considerable variations in the fluorescence quantum yield. These variations are due to the non-radiative relaxation of the absorbed energy and because of the different solvent properties. The highest quantum yield of the dye is observed in the polar protic solvent-water.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Slyusarchuk, V. E., E-mail: V.E.Slyusarchuk@gmail.com, E-mail: V.Ye.Slyusarchuk@NUWM.rv.ua
2014-06-01
The well-known theorems of Favard and Amerio on the existence of almost periodic solutions to linear and nonlinear almost periodic differential equations depend to a large extent on the H-classes and the requirement that the bounded solutions of these equations be separated. The present paper provides different conditions for the existence of almost periodic solutions. These conditions, which do not depend on the H-classes of the equations, are formulated in terms of a special functional on the set of bounded solutions of the equations under consideration. This functional is used, in particular, to test whether solutions are separated. Bibliography: 24more » titles. (paper)« less
Hoffmann, F; Windt, R; Glaeske, G
2011-07-01
As of 1 April 2007, pharmacists in Germany filling prescriptions covered by the statutory health insurance system (Gesetzliche Krankenversicherung, GKV) are required, whenever possible, to dispense a preparation for which a rebate contract is in effect. The physician can block drug substitution by crossing out 'aut idem' ('or the like') on the prescription form, for which regional variations were found. We have studied the differences between physicians belonging to different regional Associations of Statutory Health Insurance Physicians (Kassenärztliche Vereinigungen, KVs) in the use of the no-substitution option in the elderly. We used claims data of the Gmünder ErsatzKasse (GEK) and drew a random sample stratified according to the 17 KVs and 3 age groups (65-74; 75-84; 85+ years) of at least 75 continuously insured persons in October 2008 per stratum. After that, all prescriptions in which the physician could potentially have exercised a no-substitution option were selected and all relevant original prescriptions were examined. All estimates were weighted according to KVs, age groups and sex as of the structure of the GKV. The sample comprised of 3 672 persons and 5 745 prescriptions. The percentage of no-substitution prescriptions was 20.1% (95% confidence interval [95% CI] 18.7-21.5) and we found no differences according to age and sex. Considerable differences were seen between the KVs that vary 6.8-fold between 6.2% (95% CI: 3.2-9.2) in Saarland and 42.2% (95% CI: 34.1-50.4) in Saxony. The use of the no-substitution option does not depend on age and sex of the patient but rather depends on regional factors. These considerable regional differences show that, in several regions, the use of the no-substitution regulation influences the effect of rebate contracts. © Georg Thieme Verlag KG Stuttgart · New York.
Current research on parenting styles, dimensions, and beliefs.
Smetana, Judith G
2017-06-01
For decades, parenting has been characterized in terms of broad global styles, with authoritative parenting seen as most beneficial for children's development. Concerns with greater sensitivity to cultural and contextual variations have led to greater specificity in defining parenting in terms of different parenting dimensions and greater consideration of the role of parenting beliefs in moderating links between parenting and adjustment. New research includes 'domain-specific' models that describe parents as flexibly deploying different practices depending on their goals, children's needs, and the types of behaviors towards which parenting is directed. These trends are described, and directions for future research are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.
Nanoscale assembly of high-temperature oxidation-resistant nanocomposites.
Peng, Xiao
2010-02-01
Structural considerations for designing a high-temperature oxidation-resistant metallic material are proposed, based on the dependence of the material structure on a promotion of the development of a protective scale of chromia or alumina. The material should have numerous sites on its surface for nucleating the protective oxides at the onset of oxidation and abundant grain boundaries in deeper areas for simultaneously supplying sufficient flux of the protective-oxide-forming elements toward the surface for a rapid linkage of the oxide nuclei through their lateral growth. Based on these considerations, we fabricated, using an electrochemical deposition method, novel nanocomposites which have a nanocrystalline metal matrix containing Cr and/or Al nanoparticles dispersed at the nano length scale. The validity of the design considerations is verified by comparing the high-temperature oxidation of a typical Ni-Cr nanocomposite system with two types of conventional Ni-Cr materials having similar or higher Cr content but different structure: one is a composite having a nanocrystalline Ni matrix containing Cr microparticles dispersed at the microscale and the other are micron-grained Ni-Cr alloys with the Cr distribution at the atomic length scale.
Nanoscale assembly of high-temperature oxidation-resistant nanocomposites
NASA Astrophysics Data System (ADS)
Peng, Xiao
2010-02-01
Structural considerations for designing a high-temperature oxidation-resistant metallic material are proposed, based on the dependence of the material structure on a promotion of the development of a protective scale of chromia or alumina. The material should have numerous sites on its surface for nucleating the protective oxides at the onset of oxidation and abundant grain boundaries in deeper areas for simultaneously supplying sufficient flux of the protective-oxide-forming elements toward the surface for a rapid linkage of the oxide nuclei through their lateral growth. Based on these considerations, we fabricated, using an electrochemical deposition method, novel nanocomposites which have a nanocrystalline metal matrix containing Cr and/or Al nanoparticles dispersed at the nano length scale. The validity of the design considerations is verified by comparing the high-temperature oxidation of a typical Ni-Cr nanocomposite system with two types of conventional Ni-Cr materials having similar or higher Cr content but different structure: one is a composite having a nanocrystalline Ni matrix containing Cr microparticles dispersed at the microscale and the other are micron-grained Ni-Cr alloys with the Cr distribution at the atomic length scale.
NASA Astrophysics Data System (ADS)
Zhang, X.; Zhong, Z.; Ruiz, H. S.; Geng, J.; Coombs, T. A.
2017-02-01
The physical understanding and numerical modelling of superconducting devices which exploit the high performance of second generation high temperature superconducting tapes (2G-HTS), is commonly hindered by the lack of accurate functions which allow the consideration of the in-field dependence of the critical current. This is true regardless of the manufacturer of the superconducting tape. In this paper, we present a general approach for determining a unified function I c(B, θ), ultimately capable of describing the magneto-angular dependence of the in-field critical current of commercial 2G-HTS tapes in the Lorentz configuration. Five widely different superconducting tapes, provided by three different manufacturers, have been tested in a liquid nitrogen bath and external magnetic fields of up to 400 mT. The critical current was recorded at 90 different orientations of the magnetic field ranging from θ = 0°, i.e., with B aligned with the crystallographic ab-planes of the YBCO layer, towards ±90°, i.e., with B perpendicular to the wider surfaces of the 2G-HTS tape. The whole set of experimental data has been analysed using a novel multi-objective model capable of predicting a sole function I c(B, θ). This allows an accurate validation of the experimental data regardless of the fabrication differences and widths of the superconducting tapes. It is shown that, in spite of the wide set of differences between the fabrication and composition of the considered tapes, at liquid nitrogen temperature the magneto-angular dependence of the in-field critical current of YBCO-based 2G-HTS tapes, can be described by a universal function I c(f(B), θ), with a power law field dependence dominated by the Kim’s factor B/B 0, and an angular dependence moderated by the electron mass anisotropy ratio of the YBCO layer.
Clinical Considerations in the Assessment of Adolescent Chemical Dependency.
ERIC Educational Resources Information Center
Winters, Ken
1990-01-01
Discusses relevant research findings of clinical assessment of adolescent chemical dependency so that service providers can better address these concerns. Three major issues are discussed: the definition of adolescent chemical dependency, clinical domains of assessment (chemical use problem severity, precipitating and perpetuating risk factors,…
Kim, Mi Young; Kim, Eun Jin; Kim, Young-Nam; Choi, Changsun
2012-01-01
Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and β-sitosterol, were analyzed in three major species of pumpkin (Cucurbitaceae pepo, C. moschata, and C. maxima) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. C. maxima had significantly more carbohydrate, protein, fat, and fiber than C. pepo or C. moschata (P < 0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in C. pepo. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. C. pepo and C. moschata seeds had significantly more γ-tocopherol than C. maxima, whose seeds had the highest β-carotene content. C. pepo seeds had significantly more β-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed. PMID:22413037
Hydroxyl radical mediated DNA base modification by manmade mineral fibres.
Leanderson, P; Söderkvist, P; Tagesson, C
1989-01-01
Manmade mineral fibres (MMMFs) were examined for their ability to hydroxylate 2-deoxyguanosine (dG) to 8-hydroxydeoxyguanosine (8-OH-dG), a reaction that is mediated by hydroxyl radicals. It appeared that (1) catalase and the hydroxyl radical scavengers, dimethylsulphoxide and sodium benzoate, inhibited the hydroxylation, whereas Fe2+ and H2O2 potentiated it; (2) pretreatment of MMMFs with the iron chelator, deferoxamine, or with extensive heat (200-400 degrees C), attenuated the hydroxylation; (3) the hydroxylation obtained by various MMMFs varied considerably; (4) there was no apparent correlation between the hydroxylation and the surface area of different MMMFs, although increasing the surface area of a fibre by crushing it increased its hydroxylating capacity; and (5) there was good correlation between the hydroxylation of dG residues in DNA and the hydroxylation of pure dG in solution for the 16 different MMMFs investigated. These findings indicate that MMMFs cause a hydroxyl radical mediated DNA base modification in vitro and that there is considerable variation in the reactivity of different fibre species. The DNA modifying ability seems to depend on physical or chemical characteristics, or both, of the fibre. PMID:2765416
NASA Astrophysics Data System (ADS)
Amaku, M.; Coutinho, F. A.; Azevedo, R. S.; Burattini, M. N.; Lopez, L. F.; Massad, E.
2003-05-01
In this paper, we analyze the temporal evolution of the age-dependent force of infection and incidence of rubella, after the introduction of a very specific vaccination program in a previously nonvaccinated population where rubella was in endemic steady state. We deduce an integral equation for the age-dependent force of infection, which depends on a number of parameters that can be estimated from the force of infection in a steady state prior to the vaccination program. We present the results of our simulations, which are compared with observed data. We also examine the influence of contact patterns among members of a community on the age-dependent intensity of transmission of rubella and on the results of vaccination strategies. As an example of the theory proposed, we calculate the effects of vaccination strategies for four communities from Caieiras (Brazil), Huixquilucan (Mexico), Finland, and the United Kingdom. The results for each community differ considerably according to the distinct intensity and pattern of transmission in the absence of vaccination. We conclude that this simple vaccination program is not very efficient (very slow) in the goal of eradicating the disease. This gives support to a mixed strategy, proposed by Massad et al., accepted and implemented by the government of the State of São Paulo, Brazil.
How much water do we need for irrigation under Climate Change in the Mediterranean?
NASA Astrophysics Data System (ADS)
Fader, Marianela; Alberte, Bondeau; Wolfgang, Cramer; Simon, Decock; Sinan, Shi
2014-05-01
Anthropogenic climate change will very likely alter the hydrological system of already water-limited agricultural landscapes around the Mediterranean. This includes the need for, as well as the availability of irrigation water. On top of that Mediterranean agroecosystems are very likely to be under strong pressure in the near future through changes in consumer demands and diets, increasing urbanization, demographic change, and new markets for agricultural exportation. As a first step to assess the water demand of the agricultural sector, we use an ecohydrological model (the Lund-Potsdam-Jena managed land model, LPJmL) to estimate current and future irrigation water requirements of this region, considering various climate and socio-economic scenarios. LPJmL is a process-based, agricultural and water balance model, where plant growth is ecophysiologically coupled with hydrological variables. For these simulations, the model was adapted to the Mediterranean region in terms of agrosystems as well as crop parameters, and a sensitivity analysis for the irrigation system efficiency was performed. Patterns of current irrigation water requirements differ strongly spatially within the Mediterranean region depending mainly on potential evapotranspiration, the combination of crops cultivated and the extension of irrigated areas. The simulations for the future indicate that the Mediterranean may need considerable additional amounts of irrigation water. However, the regional patterns differ strongly depending on changes in length of growing periods, changes in transpirational rate (temperature and precipitation change, CO2-fertilization), and the consideration of potential improvements in irrigation system efficiency.
On the Statistical Properties of Cospectra
NASA Astrophysics Data System (ADS)
Huppenkothen, D.; Bachetti, M.
2018-05-01
In recent years, the cross-spectrum has received considerable attention as a means of characterizing the variability of astronomical sources as a function of wavelength. The cospectrum has only recently been understood as a means of mitigating instrumental effects dependent on temporal frequency in astronomical detectors, as well as a method of characterizing the coherent variability in two wavelength ranges on different timescales. In this paper, we lay out the statistical foundations of the cospectrum, starting with the simplest case of detecting a periodic signal in the presence of white noise, under the assumption that the same source is observed simultaneously in independent detectors in the same energy range. This case is especially relevant for detecting faint X-ray pulsars in detectors heavily affected by instrumental effects, including NuSTAR, Astrosat, and IXPE, which allow for even sampling and where the cospectrum can act as an effective way to mitigate dead time. We show that the statistical distributions of both single and averaged cospectra differ considerably from those for standard periodograms. While a single cospectrum follows a Laplace distribution exactly, averaged cospectra are approximated by a Gaussian distribution only for more than ∼30 averaged segments, dependent on the number of trials. We provide an instructive example of a quasi-periodic oscillation in NuSTAR and show that applying standard periodogram statistics leads to underestimated tail probabilities for period detection. We also demonstrate the application of these distributions to a NuSTAR observation of the X-ray pulsar Hercules X-1.
ERIC Educational Resources Information Center
Han, Chao
2016-01-01
As a property of test scores, reliability/dependability constitutes an important psychometric consideration, and it underpins the validity of measurement results. A review of interpreter certification performance tests (ICPTs) reveals that (a) although reliability/dependability checking has been recognized as an important concern, its theoretical…
Multi-scale correlations in different futures markets
NASA Astrophysics Data System (ADS)
Bartolozzi, M.; Mellen, C.; di Matteo, T.; Aste, T.
2007-07-01
In the present work we investigate the multiscale nature of the correlations for high frequency data (1 min) in different futures markets over a period of two years, starting on the 1st of January 2003 and ending on the 31st of December 2004. In particular, by using the concept of local Hurst exponent, we point out how the behaviour of this parameter, usually considered as a benchmark for persistency/antipersistency recognition in time series, is largely time-scale dependent in the market context. These findings are a direct consequence of the intrinsic complexity of a system where trading strategies are scale-adaptive. Moreover, our analysis points out different regimes in the dynamical behaviour of the market indices under consideration.
The “Task B problem” and other considerations in developmental functional neuroimaging
Church, Jessica A.; Petersen, Steven E.; Schlaggar, Bradley L.
2012-01-01
Functional neuroimaging provides a remarkable tool to allow us to study cognition across the lifespan and in special populations in a safe way. However, experimenters face a number of methodological issues, and these issues are particularly pertinent when imaging children. This brief article discusses assessing task performance, strategies for dealing with group performance differences, controlling for movement, statistical power, proper atlas registration, and data analysis strategies. In addition, there will be discussion of two other topics that have important implications for interpreting fMRI data: the question of whether functional neuroanatomical differences between adults and children are the consequence of putative developmental neurovascular differences, and the issue of interpreting negative blood oxygenation-level dependent (BOLD) signal change. PMID:20496376
Transverse-momentum-dependent gluon distributions from JIMWLK evolution
NASA Astrophysics Data System (ADS)
Marquet, C.; Petreska, E.; Roiesnel, C.
2016-10-01
Transverse-momentum-dependent (TMD) gluon distributions have different operator definitions, depending on the process under consideration. We study that aspect of TMD factorization in the small- x limit, for the various unpolarized TMD gluon distributions encountered in the literature. To do this, we consider di-jet production in hadronic collisions, since this process allows to be exhaustive with respect to the possible operator definitions, and is suitable to be investigated at small x. Indeed, for forward and nearly back-to-back jets, one can apply both the TMD factorization and Color Glass Condensate (CGC) approaches to compute the di-jet cross-section, and compare the results. Doing so, we show that both descriptions coincide, and we show how to express the various TMD gluon distributions in terms of CGC correlators of Wilson lines, while keeping N c finite. We then proceed to evaluate them by solving the JIMWLK equation numerically. We obtain that at large transverse momentum, the process dependence essentially disappears, while at small transverse momentum, non-linear saturation effects impact the various TMD gluon distributions in very different ways. We notice the presence of a geometric scaling regime for all the TMD gluon distributions studied: the "dipole" one, the Weizsäcker-Williams one, and the six others involved in forward di-jet production.
Raevsky, O A; Perlovich, G L; Schaper, K-J
2007-01-01
On the basis of octanol solubility data (log S(o)) for 218 structurally diverse solid chemicals it was shown that the exclusive consideration of melting points did not provide satisfactory results in the quantitative prediction of this parameter (s = 0.92). The application of HYBOT physicochemical descriptors separately (s = 0.94) and together with melting points (s = 0.70) in the framework of a common regression model also was not successful, although contributions of volume-related and H-bond terms to solubility in octanol were identified. It was proposed that the main reason for such behaviour was the different crystal lattice interaction of different classes of chemicals. Successful calculations of the solubility in octanol of chemicals of interest were performed on the basis of the experimental solubility of structurally/physicochemically/numerically similar nearest neighbours with consideration of their difference in physicochemical parameters (molecular polarisability, H-bond acceptor and donor factors (s = 0.66)) and of these descriptors together with melting point differences (s = 0.38). Good results were obtained for all compounds having nearest neighbours with sufficient similarity, expressed by Tanimoto indexes, and by distances in the scaled 3D descriptor space. Obviously the success of this approach depends on the size of the database.
A network function-based definition of communities in complex networks.
Chauhan, Sanjeev; Girvan, Michelle; Ott, Edward
2012-09-01
We consider an alternate definition of community structure that is functionally motivated. We define network community structure based on the function the network system is intended to perform. In particular, as a specific example of this approach, we consider communities whose function is enhanced by the ability to synchronize and/or by resilience to node failures. Previous work has shown that, in many cases, the largest eigenvalue of the network's adjacency matrix controls the onset of both synchronization and percolation processes. Thus, for networks whose functional performance is dependent on these processes, we propose a method that divides a given network into communities based on maximizing a function of the largest eigenvalues of the adjacency matrices of the resulting communities. We also explore the differences between the partitions obtained by our method and the modularity approach (which is based solely on consideration of network structure). We do this for several different classes of networks. We find that, in many cases, modularity-based partitions do almost as well as our function-based method in finding functional communities, even though modularity does not specifically incorporate consideration of function.
Current dental adhesives systems. A narrative review.
Milia, Egle; Cumbo, Enzo; Cardoso, Rielson Jose A; Gallina, Giuseppe
2012-01-01
Adhesive dentistry is based on the development of materials which establish an effective bond with the tooth tissues. In this context, adhesive systems have attracted considerable research interest in recent years. Successful adhesive bonding depends on the chemistry of the adhesive, on appropriate clinical handling of the material as well as on the knowledge of the morphological changes caused on dental tissue by different bonding procedures. This paper outlines the status of contemporary adhesive systems, with particular emphasis on chemical characteristics and mode of interaction of the adhesives with enamel and dentinal tissues. Dental adhesives are used for several clinical applications and they can be classified based on the clinical regimen in "etch-and-rinse adhesives" and "self-etch adhesives". Other important considerations concern the different anatomical characteristics of enamel and dentine which are involved in the bonding procedures that have also implications for the technique used as well as for the quality of the bond. Etch-and-rinse adhesive systems generally perform better on enamel than self-etching systems which may be more suitable for bonding to dentine. In order to avoid a possible loss of the restoration, secondary caries or pulp damage due to bacteria penetration or due to cytotoxicity effects of eluted adhesive components, careful consideration of several factors is essential in selecting the suitable bonding procedure and adhesive system for the individual patient situation.
47 CFR 90.165 - Procedures for mutually exclusive applications.
Code of Federal Regulations, 2014 CFR
2014-10-01
..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...
47 CFR 90.165 - Procedures for mutually exclusive applications.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...
47 CFR 90.165 - Procedures for mutually exclusive applications.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., the Commission may use competitive bidding, random selection, or comparative hearings, depending on... exclusive applications in a renewal filing group are designated for comparative consideration in a hearing... applications in the filing group for comparative consideration in a hearing. In this event, the result of the...
Considerations in Selecting Instructional Programs. Professional Paper 30.
ERIC Educational Resources Information Center
Niedermeyer, Fred C.; Moncrief, Michael H.
Effective instruction on a national scale is dependent on supplying competent teachers with comprehensive instructional materials and procedures that meet some kind of minimum criteria for accountability. Considerations included in a complete instructional system are: (1) outcomes; (2) assessment; (3) user experience data; (4) materials; (5)…
Characterizing Heart Failure in the Ventricular Volume Domain
Kerkhof, Peter LM
2015-01-01
Heart failure (HF) may be accompanied by considerable alterations of left ventricular (LV) volume, depending on the particular phenotype. Two major types of HF have been identified, although heterogeneity within each category may be considerable. All variants of HF show substantially elevated LV filling pressures, which tend to induce changes in LV size and shape. Yet, one type of HF is characterized by near-normal values for LV end-diastolic volume (EDV) and even a smaller end-systolic volume (ESV) than in matched groups of persons without cardiac disease. Furthermore, accumulating evidence indicates that, both in terms of shape and size, in men and women, the heart reacts differently to adaptive stimuli as well as to certain pharmacological interventions. Adjustments of ESV and EDV such as in HF patients are associated with (reverse) remodeling mechanisms. Therefore, it is logical to analyze HF subtypes in a graphical representation that relates ESV to EDV. Following this route, one may expect that the two major phenotypes of HF are identified as distinct entities localized in different areas of the LV volume domain. The precise coordinates of this position imply unique characteristics in terms of the actual operating point for LV volume regulation. Evidently, ejection fraction (EF; equal to 1 minus the ratio of ESV and EDV) carries little information within the LV volume representation. Thus far, classification of HF is based on information regarding EF combined with EDV. Our analysis shows that ESV in the two HF groups follows different patterns in dependency of EDV. This observation suggests that a superior HF classification system should primarily be founded on information embodied by ESV. PMID:25780344
Social welfare utilization and needs of older adults in Taiwan: survey research.
Hsieh, Hsiu-Fen; Chen, Kuei-Min; Lin, Mei-Hui; Wang, Yueh-Chin; Huang, Hsin-Ting
2014-01-01
The demand for long-term care for older adults has escalated sharply. A good policy dedicated to the welfare of older adults has improved their quality of life. The purpose of this study was to explore the social welfare utilization and needs of older adults and compare their differences among age groups, genders, and functional dependency levels. Three hundred eighty-four stratified, random-sampled Taiwanese community-dwelling older adults were recruited for this survey research. Participants rated their utilization of and needs for the 30 social welfare services provided by the government on a Likert-type scale. The most widely used and needed social welfare services by the older adults were senior monetary stipend and a subsidy for the national health insurance premium. Young-old, male, and functionally independent older adults had more knowledge of the social welfare services than their counterparts. While designing a comprehensive social welfare system, differing needs of different age groups, genders, and functional dependency levels should be taken into consideration. Copyright © 2014 Elsevier Inc. All rights reserved.
Zhang, Sheng; Li, Chiang-Shan R
2018-06-18
Research of dopaminergic deficits has focused on the ventral striatum (VS) with many studies elucidating altered resting state functional connectivity (rsFC) in individuals with cocaine dependence (CD). The VS comprises functional subregions and delineation of subregional changes in rsFC requires careful consideration of the differences between addicted and healthy populations. In the current study, we parcellated the VS using whole-brain rsFC differences between CD and non-drug-using controls (HC). Voxels with similar rsFC changes formed functional clusters. The results showed that the VS was divided into 3 subclusters, in the area of the dorsal-anterior VS (daVS), dorsal posterior VS (dpVS), and ventral VS (vVS), each in association with different patterns of rsFC. The three subregions shared reduced rsFC with bilateral hippocampal/parahippocampal gyri (HG/PHG) but also showed distinct changes, including reduced vVS rsFC with ventromedial prefrontal cortex (vmPFC) and increased daVS rsFC with visual cortex in CD as compared to HC. Across CD, daVS visual cortical connectivity was positively correlated with amount of prior-month cocaine use and cocaine craving, and vVS vmPFC connectivity was negatively correlated with the extent of depression and anxiety. These findings suggest a distinct pattern of altered VS subregional rsFC in cocaine dependence, and some of the changes have eluded analyses using the whole VS as a seed region. The findings may provide new insight to delineating VS circuit deficits in cocaine dependence and provide an alternative analytical framework to address functional dysconnectivity in other mental illnesses.
Gambling Disorder and Other Behavioral Addictions: Recognition and Treatment
Yau, Yvonne H. C.; Potenza, Marc N.
2015-01-01
Addiction professionals and the public are recognizing that certain nonsubstance behaviors—such as gambling, Internet use, video-game playing, sex, eating, and shopping—bear resemblance to alcohol and drug dependence. Growing evidence suggests that these behaviors warrant consideration as nonsubstance or “behavioral” addictions and has led to the newly introduced diagnostic category “Substance-Related and Addictive Disorders” in DSM-5. At present, only gambling disorder has been placed in this category, with insufficient data for other proposed behavioral addictions to justify their inclusion. This review summarizes recent advances in our understanding of behavioral addictions, describes treatment considerations, and addresses future directions. Current evidence points to overlaps between behavioral and substance-related addictions in phenomenology, epidemiology, comorbidity, neurobiological mechanisms, genetic contributions, responses to treatments, and prevention efforts. Differences also exist. Recognizing behavioral addictions and developing appropriate diagnostic criteria are important in order to increase awareness of these disorders and to further prevention and treatment strategies. PMID:25747926
Wang, K F; Wang, B L
2018-06-22
Determining the electric potential in a bent piezoelectric nanowire (NW) is a fundamental issue of nanogenerators and nanopiezotronics. The combined influence of the flexoelectric effect, the semiconducting performance and the angle of atomic force microscope (AFM) tip has never been studied previously and will be investigated in this paper. The exact solution for the electric potential of a bent piezoelectric semiconductor NW is derived. The electric potential of the present model with consideration of flexoelectric effect varies along the length of the NW and is different from that of the classical piezoelectric model. Flexoelectric effect enhances but the semiconducting performance reduces the electric potential of the NW. In addition, it is found that if the angle of the AFM tip reaches 30°, the error of the electric potential obtained from the model ignored the effect of the angle of the AFM tip is almost 16%, which is unacceptable.
Majchrzycka, Katarzyna; Gutarowska, Beata; Brochocka, Agnieszka
2010-01-01
This paper presents the results of a study on antimicrobial activity of polymer filter nonwovens produced by needle-punching or melt-blowing with an addition of disinfecting agents. The first part of the paper discusses how the biocidal activity of nonwovens is a function of the active agent added to the nonwovens, the duration of the contact of microorganisms with nonwovens and the type of microorganisms. The types of fibres and disinfecting agents had a considerable effect on the biocidal activity of nonwovens. The biocidal effect of nonwovens increased with the duration of their contact with microorganisms. Fibre activity differed considerably depending on the species of the microorganism. The microorganisms most sensitive to biocidal activity of the active filter nonwoven were S. aureus, M. flavus and E. coli. There were no biocidal effects on spore-forming bacterium B. subtilis.
NASA Astrophysics Data System (ADS)
Wang, K. F.; Wang, B. L.
2018-06-01
Determining the electric potential in a bent piezoelectric nanowire (NW) is a fundamental issue of nanogenerators and nanopiezotronics. The combined influence of the flexoelectric effect, the semiconducting performance and the angle of atomic force microscope (AFM) tip has never been studied previously and will be investigated in this paper. The exact solution for the electric potential of a bent piezoelectric semiconductor NW is derived. The electric potential of the present model with consideration of flexoelectric effect varies along the length of the NW and is different from that of the classical piezoelectric model. Flexoelectric effect enhances but the semiconducting performance reduces the electric potential of the NW. In addition, it is found that if the angle of the AFM tip reaches 30°, the error of the electric potential obtained from the model ignored the effect of the angle of the AFM tip is almost 16%, which is unacceptable.
Accelerated stress testing of terrestrial solar cells
NASA Technical Reports Server (NTRS)
Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.
1982-01-01
The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.
Addressing Criticality in Rare Earth Elements via Permanent Magnets Recycling
NASA Astrophysics Data System (ADS)
Nlebedim, I. C.; King, A. H.
2017-12-01
Rare earth elements (REEs) are critical for many advanced technologies and are faced with potential supply disruptions. Recycling of permanent magnets (PMs) can be good sources for REEs which can help minimize global dependence on freshly mined REEs, but PMs are rarely recycled. Recycling of PMs has been discussed with respect to improving REEs resource sustainability. Some challenges to be addressed in order to establish industrially deployable technologies for PMs recycling have also been discussed, including profitability, energy efficiency and environmental impacts. Key considerations for promoting circular economy via PMs recycling is proposed with the focus on deciding the target points in the supply chain at which the recycled products will be inserted. Important technical considerations for recycling different forms of waste PMs, including swarfs, slags, shredded and intact hard disk drives magnets, have been presented. The aspects of circular economy considered include reusing magnets, remanufacturing magnets and recovering of REEs from waste PMs.
Addressing Criticality in Rare Earth Elements via Permanent Magnets Recycling
NASA Astrophysics Data System (ADS)
Nlebedim, I. C.; King, A. H.
2018-02-01
Rare earth elements (REEs) are critical for many advanced technologies and are faced with potential supply disruptions. Recycling of permanent magnets (PMs) can be good sources for REEs which can help minimize global dependence on freshly mined REEs, but PMs are rarely recycled. Recycling of PMs has been discussed with respect to improving REEs resource sustainability. Some challenges to be addressed in order to establish industrially deployable technologies for PMs recycling have also been discussed, including profitability, energy efficiency and environmental impacts. Key considerations for promoting circular economy via PMs recycling is proposed with the focus on deciding the target points in the supply chain at which the recycled products will be inserted. Important technical considerations for recycling different forms of waste PMs, including swarfs, slags, shredded and intact hard disk drives magnets, have been presented. The aspects of circular economy considered include reusing magnets, remanufacturing magnets and recovering of REEs from waste PMs.
Müller, Jonas E. N.; Kupper, Christiane E.; Schneider, Olha; Vorholt, Julia A.; Ellingsen, Trond E.; Brautaset, Trygve
2013-01-01
Bacillus methanolicus can utilize methanol as the sole carbon source for growth and it encodes an NAD+-dependent methanol dehydrogenase (Mdh), catalyzing the oxidation of methanol to formaldehyde. Recently, the genomes of the B. methanolicus strains MGA3 (ATCC53907) and PB1 (NCIMB13113) were sequenced and found to harbor three different putative Mdh encoding genes, each belonging to the type III Fe-NAD+-dependent alcohol dehydrogenases. In each strain, two of these genes are encoded on the chromosome and one on a plasmid; only one chromosomal act gene encoding the previously described activator protein ACT was found. The six Mdhs and the ACT proteins were produced recombinantly in Escherichia coli, purified, and characterized. All Mdhs required NAD+ as cosubstrate, were catalytically stimulated by ACT, exhibited a broad and different substrate specificity range and displayed both dehydrogenase and reductase activities. All Mdhs catalyzed the oxidation of methanol; however the catalytic activity for methanol was considerably lower than for most other alcohols tested, suggesting that these enzymes represent a novel class of alcohol dehydrogenases. The kinetic constants for the Mdhs were comparable when acting as pure enzymes, but together with ACT the differences were more pronounced. Quantitative PCR experiments revealed major differences with respect to transcriptional regulation of the paralogous genes. Taken together our data indicate that the repertoire of methanol oxidizing enzymes in thermotolerant bacilli is larger than expected with complex mechanisms involved in their regulation. PMID:23527128
Krog, Anne; Heggeset, Tonje M B; Müller, Jonas E N; Kupper, Christiane E; Schneider, Olha; Vorholt, Julia A; Ellingsen, Trond E; Brautaset, Trygve
2013-01-01
Bacillus methanolicus can utilize methanol as the sole carbon source for growth and it encodes an NAD(+)-dependent methanol dehydrogenase (Mdh), catalyzing the oxidation of methanol to formaldehyde. Recently, the genomes of the B. methanolicus strains MGA3 (ATCC53907) and PB1 (NCIMB13113) were sequenced and found to harbor three different putative Mdh encoding genes, each belonging to the type III Fe-NAD(+)-dependent alcohol dehydrogenases. In each strain, two of these genes are encoded on the chromosome and one on a plasmid; only one chromosomal act gene encoding the previously described activator protein ACT was found. The six Mdhs and the ACT proteins were produced recombinantly in Escherichia coli, purified, and characterized. All Mdhs required NAD(+) as cosubstrate, were catalytically stimulated by ACT, exhibited a broad and different substrate specificity range and displayed both dehydrogenase and reductase activities. All Mdhs catalyzed the oxidation of methanol; however the catalytic activity for methanol was considerably lower than for most other alcohols tested, suggesting that these enzymes represent a novel class of alcohol dehydrogenases. The kinetic constants for the Mdhs were comparable when acting as pure enzymes, but together with ACT the differences were more pronounced. Quantitative PCR experiments revealed major differences with respect to transcriptional regulation of the paralogous genes. Taken together our data indicate that the repertoire of methanol oxidizing enzymes in thermotolerant bacilli is larger than expected with complex mechanisms involved in their regulation.
On numerical integration and computer implementation of viscoplastic models
NASA Technical Reports Server (NTRS)
Chang, T. Y.; Chang, J. P.; Thompson, R. L.
1985-01-01
Due to the stringent design requirement for aerospace or nuclear structural components, considerable research interests have been generated on the development of constitutive models for representing the inelastic behavior of metals at elevated temperatures. In particular, a class of unified theories (or viscoplastic constitutive models) have been proposed to simulate material responses such as cyclic plasticity, rate sensitivity, creep deformations, strain hardening or softening, etc. This approach differs from the conventional creep and plasticity theory in that both the creep and plastic deformations are treated as unified time-dependent quantities. Although most of viscoplastic models give better material behavior representation, the associated constitutive differential equations have stiff regimes which present numerical difficulties in time-dependent analysis. In this connection, appropriate solution algorithm must be developed for viscoplastic analysis via finite element method.
Electron localisation in static and time-dependent one-dimensional model systems
NASA Astrophysics Data System (ADS)
Durrant, T. R.; Hodgson, M. J. P.; Ramsden, J. D.; Godby, R. W.
2018-02-01
The most direct signature of electron localisation is the tendency of an electron in a many-body system to exclude other same-spin electrons from its vicinity. By applying this concept directly to the exact many-body wavefunction, we find that localisation can vary considerably between different ground-state systems, and can also be strongly disrupted, as a function of time, when a system is driven by an applied electric field. We use this measure to assess the well-known electron localisation function (ELF), both in its approximate single-particle form (often applied within density-functional theory) and its full many-particle form. The full ELF always gives an excellent description of localisation, but the approximate ELF fails in time-dependent situations, even when the exact Kohn-Sham orbitals are employed.
Meissner effect in normal-superconducting proximity-contact double layers
NASA Astrophysics Data System (ADS)
Higashitani, Seiji; Nagai, Katsuhiko
1995-02-01
The Meissner effect in normal-superconducting proximity-contact double layers is discussed in the clean limit. The diamagnetic current is calculated using the quasi-classical Green's function. We obtain the quasi-classical Green's function linear in the vector potential in the proximity-contact double layers with a finite reflection coefficient at the interface. It is found that the diamagnetic current in the clean normal layer is constant in space, therefore, the magnetic field linearly decreases in the clean normal layer. We give an explicit expression for the screening length in the clean normal layer and study its temperature dependence. We show that the temperature dependence in the clean normal layer is considerably different from that in the dirty normal layer and agrees with a recent experiment in Au-Nb system.
Outcomes in a Sample of Opiod-Dependent Clients Treated Under California's Proposition 36.
Chun, Jongserl; Guydish, Joseph R; Sorensen, James L; Haug, Nancy A; Andrews, Siara; Nelson, Larry
2007-07-01
This study evaluated treatment outcomes for the reduction of criminal justice involvement and substance use among opioid dependent clients in a therapeutic community setting under California's Proposition 36. We compared treatment outcomes between those mandated to treatment under Proposition 36 (n = 24) and those on probation but not involved in Proposition 36 (n = 61) over 12 months. Over time, both groups showed significant improvement on drug use and employment measures, were more likely to be involved in job training and less likely to be engaged in work activity, and had similar retention in treatment. There was no evidence that treatment outcomes were different between the two groups. These findings may be helpful in guiding policy makers and clinicians in states where similar initiatives are under consideration.
Nikiyan, Hike; Vasilchenko, Alexey; Deryabin, Dmitry
2010-01-01
The effect of a relative humidity (RH) in a range of 93-65% on morphological and elastic properties of Bacillus cereus and Escherichia coli cells was evaluated using atomic force microscopy. It is shown that gradual dehumidification of bacteria environment has no significant effect on cell dimensional features and considerably decreases them only at 65% RH. The increasing of the bacteria cell wall roughness and elasticity occurs at the same time. Observed changes indicate that morphological properties of B. cereus are rather stable in wide range of relative humidity, whereas E. coli are more sensitive to drying, significantly increasing roughness and stiffness parameters at RH = 84% RH. It is discussed the dependence of the response features on differences in cell wall structure of gram-positive and gram-negative bacterial cells.
NASA Astrophysics Data System (ADS)
Macklin, John W.; White, David H.
Fourier transform i.r. measurements of L-pyroglutamic acid dispersed in a matrix of a clay, silica or alumina have been obtained at various temperatures between 25 and 220°C. The i.r. spectrum of L-pyroglutamic acid varies in a manner slightly dependent upon the matrix material and shows considerable change as the temperature of the mixtures is increased. The differences in the spectrum at elevated temperatures are explained in terms of a chemical reaction between hydroxyl groups in the matrix and the carboxylic acid. The i.r. spectra of trimethylsilyl derivatives of L-pyroglutamic acid and aluminum pyroglutamate were also measured to assist the understanding of spectra and interpretation of the spectral changes dependent upon increasing temperature.
NASA Technical Reports Server (NTRS)
Macklin, J. W.; White, D. H.
1985-01-01
Fourier transform i.r. measurements of L-pyroglutamic acid dispersed in a matrix of a clay, silica or alumina have been obtained at various temperatures between 25 and 220 degrees C. The i.r. spectrum of L-pyroglutamic acid varies in a manner dependent upon the matrix material and shows considerable change as the temperature of the mixtures is increased. The differences in the spectrum at elevated temperatures are explained in terms of a chemical reaction between hydroxyl groups in the matrix and the carboxylic acid. The i.r. spectra of trimethylsilyl derivatives of L-pyroglutamic acid and aluminum pyroglutamate were also measured to assist the understanding of spectra and interpretation of the spectral changes dependent upon increasing temperature.
Electrostatic contribution to twist rigidity of DNA.
Mohammad-Rafiee, Farshid; Golestanian, Ramin
2004-06-01
The electrostatic contribution to the twist rigidity of DNA is studied, and it is shown that the Coulomb self-energy of the double-helical sugar-phosphate backbone makes a considerable contribution-the electrostatic twist rigidity of DNA is found to be C(elec) approximately 5 nm, which makes up about 7% of its total twist rigidity ( C(DNA) approximately 75 nm). The electrostatic twist rigidity is found, however, to depend only weakly on the salt concentration, because of a competition between two different screening mechanisms: (1) Debye screening by the salt ions in the bulk, and (2) structural screening by the periodic charge distribution along the backbone of the helical polyelectrolyte. It is found that, depending on the parameters, the electrostatic contribution to the twist rigidity could stabilize or destabilize the structure of a helical polyelectrolyte.
LED-Absorption-QEPAS Sensor for Biogas Plants
Köhring, Michael; Böttger, Stefan; Willer, Ulrike; Schade, Wolfgang
2015-01-01
A new sensor for methane and carbon dioxide concentration measurements in biogas plants is presented. LEDs in the mid infrared spectral region are implemented as low cost light source. The combination of quartz-enhanced photoacoustic spectroscopy with an absorption path leads to a sensor setup suitable for the harsh application environment. The sensor system contains an electronics unit and the two gas sensors; it was designed to work as standalone device and was tested in a biogas plant for several weeks. Gas concentration dependent measurements show a precision better than 1% in a range between 40% and 60% target gas concentration for both sensors. Concentration dependent measurements with different background gases show a considerable decrease in cross sensitivity against the major components of biogas in direct comparison to common absorption based sensors. PMID:26007746
Opioid Use in the Twenty First Century: Similarities and Differences Across National Borders
Vasilev, Georgi; Milcheva, Svetla; Vassileva, Jasmin
2016-01-01
Opinion Statement The global prevalence in the use of opiates and opioids has remained stable, though there were some unprecedented recent increases in opioid use and associated mortality and morbidity in the United States. Internationally, there is a strong tendency for consolidation of drug treatment strategies in favor of more systematic, structured and balanced approaches to regional and national drug policies. However, there are considerable differences in the scope, focus, and implementation of national drug policies and the political context is shaping drug prevention, treatment and rehabilitation efforts to an extent not typically observed in other public health domains. As a result, though in theory, there is a considerable multi-national agreement about the efficacy and effectiveness of different treatment modalities for opioid dependence, in practice, there are striking differences among different world regions and countries in the degree of implementation of these treatment modalities into clinical practice. Such discrepancies between theory and practice are observed even in high-income countries such as the United States and European Union member states, where evidence-based treatment modalities are still not well implemented into clinical practice. Despite the lack of evidence-based support for the role of detoxification as a stand-alone treatment for opioid use disorders, it appears to be the most widely used intervention for opioid use across the world. PMID:27493878
Leaving Fingerprints: Principals' Considerations While Implementing Education Reforms
ERIC Educational Resources Information Center
Schechter, Chen; Shaked, Haim
2017-01-01
Purpose: Turning an education reform program into school reality greatly depends on the principal. In certain cases, principals choose to implement reform instructions only partially. The purpose of this paper is to explore school principals' considerations leading to their decisions not to fulfill a national reform's guidelines in a full and…
Lonsdorf, Tina B.; Haaker, Jan; Schümann, Dirk; Sommer, Tobias; Bayer, Janine; Brassen, Stefanie; Bunzeck, Nico; Gamer, Matthias; Kalisch, Raffael
2015-01-01
Background Anxiety disorders are more prevalent in women than in men. Despite this sexual dimorphism, most experimental studies are conducted in male participants, and studies focusing on sex differences are sparse. In addition, the role of hormonal contraceptives and menstrual cycle phase in fear conditioning and extinction processes remain largely unknown. Methods We investigated sex differences in context-dependent fear acquisition and extinction (day 1) and their retrieval/expression (day 2). Skin conductance responses (SCRs), fear and unconditioned stimulus expectancy ratings were obtained. Results We included 377 individuals (261 women) in our study. Robust sex differences were observed in all dependent measures. Women generally displayed higher subjective ratings but smaller SCRs than men and showed reduced excitatory/inhibitory conditioned stimulus (CS+/CS−) discrimination in all dependent measures. Furthermore, women using hormonal contraceptives showed reduced SCR CS discrimination on day 2 than men and free-cycling women, while menstrual cycle phase had no effect. Limitations Possible limitations include the simultaneous testing of up to 4 participants in cubicles, which might have introduced a social component, and not assessing postexperimental contingency awareness. Conclusion The response pattern in women shows striking similarity to previously reported sex differences in patients with anxiety. Our results suggest that pronounced deficits in associative discrimination learning and subjective expression of safety information (CS− responses) might underlie higher prevalence and higher symptom rates seen in women with anxiety disorders. The data call for consideration of biological sex and hormonal contraceptive use in future studies and may suggest that targeting inhibitory learning during therapy might aid precision medicine. PMID:26107163
Application of Frame Theory in Intelligent Packet-Based Communication Networks
NASA Astrophysics Data System (ADS)
Escobar-Moreira, León A.
2007-09-01
Frames are a stable and redundant representation of signals in a Hilbert space that have been used in signal processing because of their resilience to additive noise, quantization error, and their robustness to losses in packet-based networks [1,2]. Depending on the number of erasures (losses), there are some considerations to be taken into account in order to optimize the frame design. Further discussions will explain the innate characteristics of frames to include intelligence on the packet-based communication devices (routers) to increase their performance under different channel behaviors.
Starch synthesis and carbon partitioning in developing endosperm.
Emes, M J; Bowsher, C G; Hedley, C; Burrell, M M; Scrase-Field, E S F; Tetlow, I J
2003-01-01
The biosynthesis of starch is the major determinant of yield in cereal grains. In this short review, attention is focused on the synthesis of the soluble substrate for starch synthesis, ADPglucose (ADPG). Consideration is given to the pathway of ADPG production, its subcellular compartmentation, and the role of metabolite transporters in mediating its delivery to the site of starch synthesis. As ADPG is an activated sugar, the dependence of its production on respiration, changes which occur during development, and the constraints which ATP production may place on carbon partitioning into different end-products are discussed.
Jarvis, M J; Russell, M A; Benowitz, N L; Feyerabend, C
1988-01-01
Cotinine elimination from plasma, saliva, and urine was studied over 11 days in five subjects (three nonsmokers and two occasional smokers). Half-lives for cotinine averaged 16-19 hours in the different body fluids (range 10 to 27 hours between subjects). There was no tendency for the half-life in saliva to be longer than in plasma or urine. We conclude that choice of body fluid for cotinine assay in smoking studies should depend on practical rather than pharmacokinetic considerations. PMID:3369603
How Internally Coupled Ears Generate Temporal and Amplitude Cues for Sound Localization.
Vedurmudi, A P; Goulet, J; Christensen-Dalsgaard, J; Young, B A; Williams, R; van Hemmen, J L
2016-01-15
In internally coupled ears, displacement of one eardrum creates pressure waves that propagate through air-filled passages in the skull and cause displacement of the opposing eardrum, and conversely. By modeling the membrane, passages, and propagating pressure waves, we show that internally coupled ears generate unique amplitude and temporal cues for sound localization. The magnitudes of both these cues are directionally dependent. The tympanic fundamental frequency segregates a low-frequency regime with constant time-difference magnification from a high-frequency domain with considerable amplitude magnification.
[Racial characteristics from the industrial anthropology aspect].
Pieper, U
1978-03-01
Often industrial-anthropological research cannot be limited to a particular population. Whenever export and/or migration brings people and conditions together which go beyond the usual area of a population characterized by a particular morphological trait, the question arises as to how technical conditions can best be adapted to humans. The automobile seat is used to illustrate to what extent race-specific size and body proportion differences effect technical practice. Since the safety of an automobile is in part dependent upon an efficient adaptation of the vehicle to the user, these investigations have considerable practical importance.
The Modification of Biocellular Chemical Reactions by Environmental Physicochemicals
NASA Astrophysics Data System (ADS)
Ishido, M.
Environmental risk factors affect human biological system to different extent from modification of biochemical reaction to cellular catastrophe. There are considerable public concerns about electromagnetic fields and endocrine disruptors. Their risk assessments have not been fully achieved because of their scientific uncertainty: electromagnetic fields just modify the bioreaction in the restricted cells and endocrine disruptors are quite unique in that their expression is dependent on the exposure periods throughout a life. Thus, we here describe their molecular characterization to establish the new risk assessments for environmental physicochemicals.
NASA Astrophysics Data System (ADS)
Vorozhtsov, S. A.; Kudryashova, O. B.; Lerner, M. I.; Vorozhtsov, A. B.; Khrustalyov, A. P.; Pervikov, A. V.
2017-11-01
The authors consider and evaluate the physical parameters and regularities of the process of consolidation of Fe-Cu, Cu-Nb, Ag-Ni, Fe-Pb nanoparticles when creating composite materials by means of shock wave compaction. As a result of theoretical consideration of explosive compaction process, researchers established and discussed the physical process conditions, established a number of threshold pressure values corresponding to different target indicators of the state of the compact. The time of shock wave impact on powders for powder consolidation was estimated.
Caetano, Raul; Ramisetty-Mikler, Suhasini; Rodriguez, Lori A
2008-05-01
The primary purpose of this article is to report 12-month prevalence rates and predictors of alcohol abuse and dependence among Mexican Americans, Cuban Americans, Puerto Ricans, and South/Central Americans living in the United States. Using a multistage cluster sample design, a total of 5,224 individuals 18 years of age and older were selected from the household population in five metropolitan areas of the United States: Miami, New York, Philadelphia, Houston, and Los Angeles. The survey weighted response rate was 76%. Personal interviews lasting an average of 1 hour were conducted in respondents' homes either in English or Spanish. There is considerable heterogeneity in rates of abuse and dependence across these national groups, with Mexican American and Puerto Rican men having higher rates than Cuban American and South/Central American men. The rates of dependence for Mexican American and Puerto Rican men are also higher than those for men in the U.S. general population. Further, although the highest rates of abuse and dependence are among those in their 20s, the rate decline with age is not as strong as in the U.S. population. Thus, Hispanics at older ages (40-49, 50-59) are at considerably more risk of dependence and its health consequences than the U.S. general population. This is particularly true of Puerto Rican and Mexican American men. Future analysis must take this heterogeneity into consideration by conducting national group-specific analysis. Prevention efforts must also be guided by these findings, which suggest that Puerto Ricans and Mexican Americans are at higher risk for abuse, dependence, and the associated consequences than the other two groups of U.S. Hispanics.
CAETANO, RAUL; RAMISETTY-MIKLER, SUHASINI; RODRIGUEZ, LORI A.
2008-01-01
Objective The primary purpose of this article is to report 12-month prevalence rates and predictors of alcohol abuse and dependence among Mexican Americans, Cuban Americans, Puerto Ricans, and South/Central Americans living in the United States. Method Using a multistage cluster sample design, a total of 5,224 individuals 18 years of age and older were selected from the household population in five metropolitan areas of the United States: Miami, New York, Philadelphia, Houston, and Los Angeles. The survey weighted response rate was 76%. Personal interviews lasting an average of 1 hour were conducted in respondents’ homes either in English or Spanish. Results There is considerable heterogeneity in rates of abuse and dependence across these national groups, with Mexican American and Puerto Rican men having higher rates than Cuban American and South/Central American men. The rates of dependence for Mexican American and Puerto Rican men are also higher than those for men in the U.S. general population. Further, although the highest rates of abuse and dependence are among those in their 20s, the rate decline with age is not as strong as in the U.S. population. Thus, Hispanics at older ages (40–49, 50–59) are at considerably more risk of dependence and its health consequences than the U.S. general population. This is particularly true of Puerto Rican and Mexican American men. Conclusions Future analysis must take this heterogeneity into consideration by conducting national group-specific analysis. Prevention efforts must also be guided by these findings, which suggest that Puerto Ricans and Mexican Americans are at higher risk for abuse, dependence, and the associated consequences than the other two groups of U.S. Hispanics. PMID:18432387
A game theory analysis of green infrastructure stormwater management policies
NASA Astrophysics Data System (ADS)
William, Reshmina; Garg, Jugal; Stillwell, Ashlynn S.
2017-09-01
Green stormwater infrastructure has been demonstrated as an innovative water resources management approach that addresses multiple challenges facing urban environments. However, there is little consensus on what policy strategies can be used to best incentivize green infrastructure adoption by private landowners. Game theory, an analysis framework that has historically been under-utilized within the context of stormwater management, is uniquely suited to address this policy question. We used a cooperative game theory framework to investigate the potential impacts of different policy strategies used to incentivize green infrastructure installation. The results indicate that municipal regulation leads to the greatest reduction in pollutant loading. However, the choice of the "best" regulatory approach will depend on a variety of different factors including politics and financial considerations. Large, downstream agents have a disproportionate share of bargaining power. Results also reveal that policy impacts are highly dependent on agents' spatial position within the stormwater network, leading to important questions of social equity and environmental justice.
NASA Astrophysics Data System (ADS)
Asatrian, H. M.; Hovhannisyan, A.; Nierste, U.; Yeghiazaryan, A.
2017-10-01
We calculate a class of three-loop Feynman diagrams which contribute to the next-to-next-to-leading logarithmic approximation for the width difference ΔΓ s in the {B}_s-{\\overline{B}}_s system. The considered diagrams contain a closed fermion loop in a gluon propagator and constitute the order α s 2 N f , where N f is the number of light quarks. Our results entail a considerable correction in that order, if ΔΓ s is expressed in terms of the pole mass of the bottom quark. If the \\overline{MS} scheme is used instead, the correction is much smaller. As a result, we find a decrease of the scheme dependence. Our result also indicates that the usually quoted value of the NLO renormalization scale dependence underestimates the perturbative error.
BIMLR: a method for constructing rooted phylogenetic networks from rooted phylogenetic trees.
Wang, Juan; Guo, Maozu; Xing, Linlin; Che, Kai; Liu, Xiaoyan; Wang, Chunyu
2013-09-15
Rooted phylogenetic trees constructed from different datasets (e.g. from different genes) are often conflicting with one another, i.e. they cannot be integrated into a single phylogenetic tree. Phylogenetic networks have become an important tool in molecular evolution, and rooted phylogenetic networks are able to represent conflicting rooted phylogenetic trees. Hence, the development of appropriate methods to compute rooted phylogenetic networks from rooted phylogenetic trees has attracted considerable research interest of late. The CASS algorithm proposed by van Iersel et al. is able to construct much simpler networks than other available methods, but it is extremely slow, and the networks it constructs are dependent on the order of the input data. Here, we introduce an improved CASS algorithm, BIMLR. We show that BIMLR is faster than CASS and less dependent on the input data order. Moreover, BIMLR is able to construct much simpler networks than almost all other methods. BIMLR is available at http://nclab.hit.edu.cn/wangjuan/BIMLR/. © 2013 Elsevier B.V. All rights reserved.
Dynamic effects of memory in a cobweb model with competing technologies
NASA Astrophysics Data System (ADS)
Agliari, Anna; Naimzada, Ahmad; Pecora, Nicolò
2017-02-01
We analyze a simple model based on the cobweb demand-supply framework with costly innovators and free imitators and study the endogenous dynamics of price and firms' fractions in a homogeneous good market. The evolutionary selection between technologies depends on a performance measure in which a memory parameter is introduced. The resulting dynamics is then described by a two-dimensional map. In addition to the locally stabilizing effect due to the presence of memory, we show the existence of a double stability threshold which entails for different dynamic scenarios occurring when the memory parameter takes extreme values (i.e. when consideration of the last profit realization prevails or it is too much neglected). The eventuality of different coexisting attractors as well as the structure of the basins of attraction that characterizes the path dependence property of the model with memory is shown. In particular, through global analysis we also illustrate particular bifurcations sequences that may increase the complexity of the related basins of attraction.
NASA Astrophysics Data System (ADS)
Zapata-Herrera, Mario; Camacho, Ángela S.; Ramírez, Hanz Y.
2018-06-01
In this paper, different confinement potential approaches are considered in the simulation of size effects on the optical response of silver spheres with radii at the few nanometer scale. By numerically obtaining dielectric functions from different sets of eigenenergies and eigenstates, we simulate the absorption spectrum and the field enhancement factor for nanoparticles of various sizes, within a quantum framework for both infinite and finite potentials. The simulations show significant dependence on the sphere radius of the dipolar surface plasmon resonance, as a direct consequence of energy discretization associated to the strong confinement experienced by conduction electrons in small nanospheres. Considerable reliance of the calculated optical features on the chosen wave functions and transition energies is evidenced, so that discrepancies in the plasmon resonance frequencies obtained with the three studied models reach up to above 30%. Our results are in agreement with reported measurements and shade light on the puzzling shift of the plasmon resonance in metallic nanospheres.
Munkvold, Linda; Lundervold, Astri; Lie, Stein Atle; Manger, Terje
2009-10-01
To examine the occurrence of oppositional defiant disorder (ODD) symptoms in a general population of boys and girls, as reported by parents and teachers, and to investigate differences in prevalence estimates, depending on how parents' and teachers' ratings were combined. Data were collected from 7007 children (aged 7-9) who participated in The Bergen Child Study (BCS), an ongoing population-based study of children's development and mental health. ODD symptoms were measured by the SNAP-IV (Swanson, Nolan, & Pelham-IV) Oppositional Defiant Disorder sub-scale (SNAP-IV ODD) that was distributed to parents and teachers. Co-occurring symptoms of mental health problems were measured by the Strengths and Difficulties Questionnaire (SDQ). Prevalence-estimates of ODD varied considerably depending on how ratings from parents and teachers were combined. Specific ODD symptoms occurred at very different rates depending on the rater and on the gender of the child being rated. Parents and teachers co-identified very few children with ODD. ODD identified by only one informant was associated with high levels of comorbid mental health problems and impairment according to both informants. The results support an informant-specific conceptualization of childhood ODD.
An information driven strategy to support multidisciplinary design
NASA Technical Reports Server (NTRS)
Rangan, Ravi M.; Fulton, Robert E.
1990-01-01
The design of complex engineering systems such as aircraft, automobiles, and computers is primarily a cooperative multidisciplinary design process involving interactions between several design agents. The common thread underlying this multidisciplinary design activity is the information exchange between the various groups and disciplines. The integrating component in such environments is the common data and the dependencies that exist between such data. This may be contrasted to classical multidisciplinary analyses problems where there is coupling between distinct design parameters. For example, they may be expressed as mathematically coupled relationships between aerodynamic and structural interactions in aircraft structures, between thermal and structural interactions in nuclear plants, and between control considerations and structural interactions in flexible robots. These relationships provide analytical based frameworks leading to optimization problem formulations. However, in multidisciplinary design problems, information based interactions become more critical. Many times, the relationships between different design parameters are not amenable to analytical characterization. Under such circumstances, information based interactions will provide the best integration paradigm, i.e., there is a need to model the data entities and their dependencies between design parameters originating from different design agents. The modeling of such data interactions and dependencies forms the basis for integrating the various design agents.
Current knowledge of microRNA-mediated regulation of drug metabolism in humans.
Nakano, Masataka; Nakajima, Miki
2018-05-01
Understanding the factors causing inter- and intra-individual differences in drug metabolism potencies is required for the practice of personalized or precision medicine, as well as for the promotion of efficient drug development. The expression of drug-metabolizing enzymes is controlled by transcriptional regulation by nuclear receptors and transcriptional factors, epigenetic regulation, such as DNA methylation and histone acetylation, and post-translational modification. In addition to such regulation mechanisms, recent studies revealed that microRNAs (miRNAs), endogenous ~22-nucleotide non-coding RNAs that regulate gene expression through the translational repression and degradation of mRNAs, significantly contribute to post-transcriptional regulation of drug-metabolizing enzymes. Areas covered: This review summarizes the current knowledge regarding miRNAs-dependent regulation of drug-metabolizing enzymes and transcriptional factors and its physiological and clinical significance. We also describe recent advances in miRNA-dependent regulation research, showing that the presence of pseudogenes, single-nucleotide polymorphisms, and RNA editing affects miRNA targeting. Expert opinion: It is unwavering fact that miRNAs are critical factors causing inter- and intra-individual differences in the expression of drug-metabolizing enzymes. Consideration of miRNA-dependent regulation would be a helpful tool for optimizing personalized and precision medicine.
A Temperature-Dependent Battery Model for Wireless Sensor Networks.
Rodrigues, Leonardo M; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco
2017-02-22
Energy consumption is a major issue in Wireless Sensor Networks (WSNs), as nodes are powered by chemical batteries with an upper bounded lifetime. Estimating the lifetime of batteries is a difficult task, as it depends on several factors, such as operating temperatures and discharge rates. Analytical battery models can be used for estimating both the battery lifetime and the voltage behavior over time. Still, available models usually do not consider the impact of operating temperatures on the battery behavior. The target of this work is to extend the widely-used Kinetic Battery Model (KiBaM) to include the effect of temperature on the battery behavior. The proposed Temperature-Dependent KiBaM (T-KiBaM) is able to handle operating temperatures, providing better estimates for the battery lifetime and voltage behavior. The performed experimental validation shows that T-KiBaM achieves an average accuracy error smaller than 0.33%, when estimating the lifetime of Ni-MH batteries for different temperature conditions. In addition, T-KiBaM significantly improves the original KiBaM voltage model. The proposed model can be easily adapted to handle other battery technologies, enabling the consideration of different WSN deployments.
A Temperature-Dependent Battery Model for Wireless Sensor Networks
Rodrigues, Leonardo M.; Montez, Carlos; Moraes, Ricardo; Portugal, Paulo; Vasques, Francisco
2017-01-01
Energy consumption is a major issue in Wireless Sensor Networks (WSNs), as nodes are powered by chemical batteries with an upper bounded lifetime. Estimating the lifetime of batteries is a difficult task, as it depends on several factors, such as operating temperatures and discharge rates. Analytical battery models can be used for estimating both the battery lifetime and the voltage behavior over time. Still, available models usually do not consider the impact of operating temperatures on the battery behavior. The target of this work is to extend the widely-used Kinetic Battery Model (KiBaM) to include the effect of temperature on the battery behavior. The proposed Temperature-Dependent KiBaM (T-KiBaM) is able to handle operating temperatures, providing better estimates for the battery lifetime and voltage behavior. The performed experimental validation shows that T-KiBaM achieves an average accuracy error smaller than 0.33%, when estimating the lifetime of Ni-MH batteries for different temperature conditions. In addition, T-KiBaM significantly improves the original KiBaM voltage model. The proposed model can be easily adapted to handle other battery technologies, enabling the consideration of different WSN deployments. PMID:28241444
Contribution potential of glaciers to water availability in different climate regimes
Kaser, Georg; Großhauser, Martin; Marzeion, Ben
2010-01-01
Although reliable figures are often missing, considerable detrimental changes due to shrinking glaciers are universally expected for water availability in river systems under the influence of ongoing global climate change. We estimate the contribution potential of seasonally delayed glacier melt water to total water availability in large river systems. We find that the seasonally delayed glacier contribution is largest where rivers enter seasonally arid regions and negligible in the lowlands of river basins governed by monsoon climates. By comparing monthly glacier melt contributions with population densities in different altitude bands within each river basin, we demonstrate that strong human dependence on glacier melt is not collocated with highest population densities in most basins. PMID:21059938
The relationships between Japanese interpersonal conflict styles and their language expressions.
Moriizumi, Satoshi; Takai, Jiro
2010-01-01
The present study investigated the influence of interpersonal conflict management styles on language expressions and the differences in expressions in same-sex relational categories based on specific in-group-out-group classifications. Questionnaires were administered to 367 university students in Japan. After reading a scenario, participants reported on actual language use and gave ratings on an interpersonal conflict management scale. The results revealed that Japanese change their expressions, along with psychological styles, depending on the relational target. They also indicated psychological constructs were related to their equivalent expressions. The results suggested that future research should take into consideration the potential differences in behavior and interaction posture inherent in various relational and situational categories.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Subedi, P.; Matthaeus, W. H.; Chuychai, P.
The investigation of the diffusive transport of charged particles in a turbulent magnetic field remains a subject of considerable interest. Research has most frequently concentrated on determining the diffusion coefficient in the presence of a mean magnetic field. Here we consider the diffusion of charged particles in fully three-dimensional isotropic turbulent magnetic fields with no mean field, which may be pertinent to many astrophysical situations. We identify different ranges of particle energy depending upon the ratio of Larmor radius to the characteristic outer length scale of turbulence. Two different theoretical models are proposed to calculate the diffusion coefficient, each applicablemore » to a distinct range of particle energies. The theoretical results are compared to those from computer simulations, showing good agreement.« less
Boos, Moritz; Seer, Caroline; Lange, Florian; Kopp, Bruno
2016-01-01
Cognitive determinants of probabilistic inference were examined using hierarchical Bayesian modeling techniques. A classic urn-ball paradigm served as experimental strategy, involving a factorial two (prior probabilities) by two (likelihoods) design. Five computational models of cognitive processes were compared with the observed behavior. Parameter-free Bayesian posterior probabilities and parameter-free base rate neglect provided inadequate models of probabilistic inference. The introduction of distorted subjective probabilities yielded more robust and generalizable results. A general class of (inverted) S-shaped probability weighting functions had been proposed; however, the possibility of large differences in probability distortions not only across experimental conditions, but also across individuals, seems critical for the model's success. It also seems advantageous to consider individual differences in parameters of probability weighting as being sampled from weakly informative prior distributions of individual parameter values. Thus, the results from hierarchical Bayesian modeling converge with previous results in revealing that probability weighting parameters show considerable task dependency and individual differences. Methodologically, this work exemplifies the usefulness of hierarchical Bayesian modeling techniques for cognitive psychology. Theoretically, human probabilistic inference might be best described as the application of individualized strategic policies for Bayesian belief revision. PMID:27303323
Antioxidant properties of Mediterranean food plant extracts: geographical differences.
Schaffer, S; Schmitt-Schillig, S; Müller, W E; Eckert, G P
2005-03-01
Locally grown, wild food plants seasonally contribute a considerable portion of the daily diet in certain Mediterranean areas and it has been suggested that the beneficial effects of the Mediterranean diet on human health partly originate from the antioxidant effect of flavonoid-rich food plants. The nutrient content of most wild plants is higher than that of cultivated ones and may vary depending on the prevailing environmental conditions. Accordingly, three local Mediterranean plant foods (i.e. Cichorium intybus, Sonchus oleraceus, Papaver rhoeas) were collected in Greece (Crete), southern Italy, and southern Spain in order to assess possible differences in their in vitro antioxidant potential. The biological assays revealed diverse intra-plant specific antioxidant effects for the tested extracts ranging from no activity to almost complete protection. Furthermore, substantial differences in the polyphenol content were found for the nutritionally used part of the same plant originating from different locations. However, no clear correlations between the polyphenol content and the extracts' antioxidant activities were found. Taken together, the data suggest that certain local Mediterranean plant foods possess promising antioxidant activity and that the observed biological effects are possibly influenced by the geographically-dependent environmental conditions prevailing during plant growth.
Local neighborhood transition probability estimation and its use in contextual classification
NASA Technical Reports Server (NTRS)
Chittineni, C. B.
1979-01-01
The problem of incorporating spatial or contextual information into classifications is considered. A simple model that describes the spatial dependencies between the neighboring pixels with a single parameter, Theta, is presented. Expressions are derived for updating the posteriori probabilities of the states of nature of the pattern under consideration using information from the neighboring patterns, both for spatially uniform context and for Markov dependencies in terms of Theta. Techniques for obtaining the optimal value of the parameter Theta as a maximum likelihood estimate from the local neighborhood of the pattern under consideration are developed.
Pressure dependence of band-gap and phase transitions in bulk CuX (X = Cl, Br, I)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Azhikodan, Dilna; Nautiyal, Tashi; Sharma, S.
2016-05-06
Usually a phase transition, in theoretical studies, is explored or verified by studying the total energy as a function of the volume considering various plausible phases. The intersection point, if any, of the free energy vs. volume curves for the different phases is then the indicator of the phase transition(s). The question is, can the theoretical study of a single phase alone indicate a phase transition? i.e. can we look beyond the phase under consideration through such a study? Using density-functional theory, we report a novel approach to suggest phase transition(s) through theoretical study of a single phase. Copper halidesmore » have been engaged for this study. These are direct band-gap semiconductors, with zinc blende structure at ambient conditions, and are reported to exhibit many phase transitions. We show that the study of volume dependence of energy band-gap in a single phase facilitates looking beyond the phase under consideration. This, when translated to pressures, reflects the phase transition pressures for CuX (X = Cl, Br, I) with an encouraging accuracy. This work thus offers a simple, yet reliable, approach based on electronic structure calculations to investigate new semiconducting materials for phase changes under pressure.« less
Financial and economic considerations for emergency response providers.
Liong, Anne S; Liong, Samuel U
2010-12-01
Catastrophic events often threaten or cause depletion of resources. It is generally accepted that changes inherent to disasters are stressful. The Conservation of Resources Theory predicts that positive and negative changes in resources will have markedly different effects.28 This theory proposes that resource losses are psychologically stressful, whereas resource gains buffer against the effects of resource loss. For first responders, the level of preparedness is crucial. Investments in planning, training, and logistics are necessary to mitigate the stress associated with a crisis. Stress is also related to not knowing the future of their loved ones if death or permanent incapacity occurs, hence specific laws and financial resources provide a safety net to dependents of first responders and survivors. This kind of safety gives the first responders peace of mind and assurance that the future of their dependents will not be jeopardized. Incentives that are offered let the first responders know that they are valued and appreciated. Indeed, financial support considerably helps first responders before, during, and after catastrophic events. It assists them to cope with stress at the individual level and allows them to become more resilient; this resonates to the community and country in which they serve and enhances their potential to save lives and prevent disabilities. Copyright © 2010 Elsevier Inc. All rights reserved.
Temperature dependence of surface tension of molten iron under reducing gas atmosphere
NASA Astrophysics Data System (ADS)
Ozawa, S.; Takahashi, S.; Fukuyama, H.; Watanabe, M.
2011-12-01
Surface tension of molten iron was measured under Ar-He-5vol.%H2 gas by oscillating droplet method using electromagnetic levitation furnace in consideration of the temperature dependence of oxygen partial pressure, Po2, of the gas. For comparison, the measurement was carried under Ar-He atmosphere to fix the Po2 of the inlet gas at 10-2Pa. The surface tension was successfully measured over a wide temperature range of about 780K including undercooling condition. When Po2 is fixed at 10-2 Pa, the surface tension increased and then decreased with increasing temperature like a boomerang shape. When the measurement was carried out under the H2-containing gas atmosphere, the temperature dependence of the surface tension shows unique kink at around 1810K instead of liner relationship due to competition between the temperature dependence of the Po2 and that of the equilibrium constant of oxygen adsorption reaction. The relationship between the calculated lnKad with respect to inverse temperature using Szyszkowski model was different between the atmospheric gases.
NASA Astrophysics Data System (ADS)
Batten, Jonathan A.; Szilagyi, Peter G.
2007-03-01
Using a daily time series from 1983 to 2005 of currency prices in spot and forward USD/Yen markets and matching equivalent maturity short-term US and Japanese interest rates, we investigate the sensitivity of the difference between actual prices in forward markets to those calculated from differentials in short-term interest rates. According to a fundamental theorem in financial economics termed covered interest parity (CIP), the actual and estimated prices should be identical once transaction and other costs are accommodated. The paper presents three important findings: first, we find evidence of considerable variation in CIP deviations from equilibrium; second, these deviations have diminished significantly and by 2000 have been almost eliminated; third, an analysis of the CIP deviations using the local Hurst exponent finds episodes of time-varying dependence over the various sample periods, which appear to be linked to episodes of dollar decline/Yen appreciation, or vice versa. The finding of temporal long-term dependence in CIP deviations is consistent with recent evidence of temporal long-term dependence in the returns of currency, stock and commodity markets.
Berthelsen, Connie Bøttcher; Lindhardt, Tove; Frederiksen, Kirsten
2017-06-01
This paper presents a discussion of the differences in using participant observation as a data collection method by comparing the classic grounded theory methodology of Barney Glaser with the constructivist grounded theory methodology by Kathy Charmaz. Participant observations allow nursing researchers to experience activities and interactions directly in situ. However, using participant observations as a data collection method can be done in many ways, depending on the chosen grounded theory methodology, and may produce different results. This discussion shows that how the differences between using participant observations in classic and constructivist grounded theory can be considerable and that grounded theory researchers should adhere to the method descriptions of performing participant observations according to the selected grounded theory methodology to enhance the quality of research. © 2016 Nordic College of Caring Science.
Care mapping in clinical neuroscience settings: Cognitive impairment and dependency.
Leigh, Andrew James; O'Hanlon, Katie; Sheldrick, Russell; Surr, Claire; Hare, Dougal Julian
2015-01-01
Person-centred care can improve the well-being of patients and is therefore a key driver in healthcare developments in the UK. The current study aims to investigate the complex relationship between cognitive impairment, dependency and well-being in people with a wide range of acquired brain and spinal injuries. Sixty-five participants, with varied acquired brain and spinal injuries, were selected by convenience sampling from six inpatient clinical neuroscience settings. Participants were observed using Dementia Care Mapping - Neurorehabilitation (DCM-NR) and categorised based on severity of cognitive impairment. A significant difference in the behaviours participants engaged in, their well-being and dependency was found between the severe cognitive impairment group and the mild, moderate or no cognitive impairment groups. Dependency and cognitive impairment accounted for 23.9% of the variance in well-ill-being scores and 17.2% of the variance in potential for positive engagement. The current study highlights the impact of severe cognitive impairment and dependency on the behaviours patients engaged in and their well-being. It also affirms the utility of DCM-NR in providing insights into patient experience. Consideration is given to developing DCM-NR as a process that may improve person-centred care in neuroscience settings.
Analytical model for the threshold voltage of III-V nanowire transistors including quantum effects
NASA Astrophysics Data System (ADS)
Marin, E. G.; Ruiz, F. G.; Tienda-Luna, I. M.; Godoy, A.; Gámiz, F.
2014-02-01
In this work we propose an analytical model for the threshold voltage (VT) of III-V cylindrical nanowires, that takes into consideration the two dimensional quantum confinement of the carriers, the Fermi-Dirac statistics, the wave-function penetration into the gate insulator and the non-parabolicity of the conduction band structure. A simple expression for VT is obtained assuming some suitable approximations. The model results are compared to those of a 2D self consistent Schrödinger-Poisson solver, demonstrating a good fit for different III-V materials, insulator thicknesses and nanowire sizes with diameter down to 5 nm. The VT dependence on the confinement effective mass is discussed. The different contributions to VT are analyzed showing significant variations among different III-V materials.
Bark Beetle-Fungal Symbiosis: Context Dependency in Complex Associations
Kier D. Klepzig; D.L. Six
2004-01-01
Recent thinking in symbiosis research has emphasized a holistic consideration of these complex interactions. Bark beetles and their associated microbes are one group which has previously not been addressed in this manner. We review the study of symbiotic interactions among bark beetles and microbes in light of this thinking. We describe the considerable progress...
Camart, N; Cotte, M; Leignel, S; Bouvet, C; Limosin, F
2016-12-01
Literature reports particularities in certain psychological dimensions, such as personality traits, early maladaptive schemas and attachment styles among patients dependent on alcohol. Several international studies have also emphasized significant gender differences in psychological profiles. However, in France, only a few studies have dealt with this subject. Our aim was on the one hand to study the characteristics of alcohol-dependent patients in these variables, and on the other hand to search for gender differences. The personality dimensions were assessed with the French Big Five Inventory (Fr-BFI), the attachment style with Bartholomew's Relationship Scales Questionnaire (RSQ), and early maladaptive schemas with the short version of Young's questionnaire (YSQ-S1). Seventy-three subjects were included: 39 alcohol-dependent patients (19 men and 20 women) and 34 healthy control subjects (17 men and 17 women). The scores of alcohol-dependent patients were compared with those of a healthy control group (n=34, 17 men, 17 women) and available standards. We also compared the scores of men and women with alcohol dependence between them, and we compared the scores of men and women to those of the control group and those of the reference sample of the same sex. This is an ongoing study and we publish here the first results. Compared with control subjects, and the reference sample, alcohol-dependent patients showed significantly higher levels of neuroticism and lower levels of extraversion. Furthermore, differences in attachment styles were observed compared to the control group: alcohol-dependent patients presented a less secure attachment, seemed more fearful and detached, but the results remained within the normal standards. Compared to the control subjects, alcohol-dependent patients showed a significant increase in scores regarding many schemas: emotional deprivation, abandonment, abuse/mistrust, isolation, imperfection, dependence, symbiotic relationship, subjugation, and emotional inhibition. Men and women with alcohol dependence did not show a significant difference between them concerning the dimensions of personality, the schemas, and attachment styles. In addition, the comparison of each sub-group (male/female) with the control group of the same sex and standards available showed specific features: for dimensions of personality, alcohol-dependent men presented a high level of neuroticism and a low level of extraversion, while the women showed no specific features. Concerning attachment, both men and women differed from the control group. Their attachment was more fearful and men showed a less secure and more detached attachment. As for patterns, three are higher among men and women with alcohol dependence compared to controls of the same sex: emotional deprivation, abuse/mistrust, and imperfection. In addition, these schemas seem to be more specific according to gender: alcoholic women differed from controls of the same sex at the subjugation schema, which was not the case for men, while only men differed from men of the control group by higher scores in insufficient self-control, dependency and symbiotic relationship. This study shows not only particularities in patients with alcohol dependence concerning personality dimensions, styles of attachment and early maladaptive schemas, but also gender differences when comparing each subgroup (men and women) with controls of the same sex. Even if these results need to be confirmed by using a larger sample, the particularities deserve consideration, especially gender differences in view of appropriate psychotherapeutic strategies. Copyright © 2016 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.
Field quantization and squeezed states generation in resonators with time-dependent parameters
NASA Technical Reports Server (NTRS)
Dodonov, V. V.; Klimov, A. B.; Nikonov, D. E.
1992-01-01
The problem of electromagnetic field quantization is usually considered in textbooks under the assumption that the field occupies some empty box. The case when a nonuniform time-dependent dielectric medium is confined in some space region with time-dependent boundaries is studied. The basis of the subsequent consideration is the system of Maxwell's equations in linear passive time-dependent dielectric and magnetic medium without sources.
Cheng, Wan-Ju; Cheng, Yawen; Huang, Ming-Chyi; Chen, Chiou-Jong
2012-01-01
To examine the association between work characteristics and the risk of alcohol dependence across different employment types and occupations, including the pattern of alcohol consumption in the form of energy drinks and its association with alcohol dependence. A total of 13,501 men and 8584 women participated in a national survey in Taiwan. Alcohol dependence was defined as ≥2 points in the CAGE questionnaire. A self-administered questionnaire recorded drinking behaviors, consumption of alcoholic energy drinks, employment type, occupation and a number of psychosocial work stressors, namely job demands, job control, employment security and workplace justice. Of the total, 9.4% of men and 0.8% of women were CAGE-positive, and 6.0% of men and 0.7% of women regularly consumed alcoholic energy drinks. In male and female regular consumers of alcoholic energy drinks, 38.7 and 23.3%, respectively, were alcohol-dependent. Multivariate regression analyses showed that male employees in manual skilled occupations, with lower workplace justice, having weekly working hours <40 h and on piece-rated or time-based pay systems were at higher risks of alcohol dependence. Certain occupational groups and workers with adverse psychosocial work characteristics should be targets for prevention of alcohol dependence. Alcoholic energy drink consumption should be taken into consideration while studying alcohol dependence in the work population in Taiwan.
Pinho, Maria João; Pinto, Vanda; Serrão, Maria Paula; Jose, Pedro A; Soares-da-Silva, Patrício
2007-07-01
This study examined the inward transport of l-[(14)C]alanine, an ASCT2 preferential substrate, in monolayers of immortalized renal proximal tubular epithelial (PTE) cells from Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. The expression of ASCT2 in WKY and SHR PTE cells and kidney cortices from WKY and SHR was also evaluated. l-[(14)C]alanine uptake was highly dependent on extracellular Na(+). Replacement of NaCl by LiCl or choline chloride abolished transport activity in SHR and WKY PTE cells. In the presence of the system L inhibitor BCH, Na(+)-dependent l-alanine uptake in WKY and SHR PTE cells was inhibited by alanine, serine, and cysteine, which is consistent with amino acid transport through ASCT2. The saturable component of Na(+)-dependent l-alanine transport under V(max) conditions in SHR PTE cells was one-half of that in WKY PTE cells, with similar K(m) values. Differences in magnitude of Na(+)-dependent l-alanine uptake through ASCT2 between WKY and SHR PTE cells correlated positively with differences in ASCT2 protein expression, this being more abundant in WKY PTE cells. Abundance of ASCT2 transcript and protein in kidney cortices of SHR rats was also lower than that in normotensive WKY rats. In conclusion, immortalized SHR and WKY PTE cells take up l-alanine mainly through a high-affinity Na(+)-dependent amino acid transporter, with functional features of ASCT2 transport. The activity and expression of the ASCT2 transporter were considerably lower in the SHR cells.
NASA Astrophysics Data System (ADS)
Veselkov, Alexei N.; Evstigneev, Maxim P.; Veselkov, Dennis A.; Davies, David B.
2001-08-01
A general nuclear magnetic resonance analysis of a statistical-thermodynamical model of hetero-association of aromatic molecules in solution has been developed to take "edge effects" into consideration, i.e., the dependence of proton chemical shifts on the position of the molecule situated inside or at the edge of the aggregate. This generalized approach is compared with a previously published model, where an average contribution to proton shielding is considered irrespective of the position of the molecule in the stack. Association parameters have been determined from experimental concentration and temperature dependences of 500 MHz proton chemical shifts of the hetero-association of the acridine dye, proflavine, and the phenanthridinium dye, ethidium bromide, in aqueous solution. Differences in the parameters in the range 10%-30% calculated using the basic and generalized approaches have been found to depend substantially on the magnitude of the equilibrium hetero-association constant Khet—the larger the value of Khet, the higher the discrepancy between the two methods.
Neurocognitive ability in adults coping with alcohol and drug relapse temptations.
Tapert, Susan F; Ozyurt, Saba Senses; Myers, Mark G; Brown, Sandra A
2004-05-01
Coping is important for preventing relapse, but may be utilized differently depending on the individual's level of cognitive functioning. Impaired reasoning, attention, and memory are commonly observed in alcohol-dependent individuals. This study describes the prospective relationship between neuropsychological functioning and utilization of coping strategies in predicting outcome one year after discharge from an inpatient alcohol treatment program. Male veterans (n = 43) hospitalized in an alcohol treatment facility were given structured interviews, coping questionnaires, and neuropsychological testing, and were followed three and 12 months after discharge. Neuropsychological ability moderated the relationship between coping and drinking outcomes one year after treatment. This was particularly true for patients with better neurocognitive functioning. Specifically, patients with higher neurocognitive performances and more maladaptive coping responses, such as self-blame, had a greater percentage of drinking days at follow-up. Alcohol-dependent adults with good neuropsychological functioning may be able to benefit more from coping skills training. For those with neuropsychological deficits, coping skills training may need to take cognitive limitations into consideration.
Analytical Description of the H/D Exchange Kinetic of Macromolecule.
Kostyukevich, Yury; Kononikhin, Alexey; Popov, Igor; Nikolaev, Eugene
2018-04-17
We present the accurate analytical solution obtained for the system of rate equations describing the isotope exchange process for molecules containing an arbitrary number of equivalent labile atoms. The exact solution was obtained using Mathematica 7.0 software, and this solution has the form of the time-dependent Gaussian distribution. For the case when forward exchange considerably overlaps the back exchange, it is possible to estimate the activation energy of the reaction by obtaining a temperature dependence of the reaction degree. Using a previously developed approach for performing H/D exchange directly in the ESI source, we have estimated the activation energies for ions with different functional groups and they were found to be in a range 0.04-0.3 eV. Since the value of the activation energy depends on the type of functional group, the developed approach can have potential analytical applications for determining types of functional groups in complex mixtures, such as petroleum, humic substances, bio-oil, and so on.
A comparison of analysis methods to estimate contingency strength.
Lloyd, Blair P; Staubitz, Johanna L; Tapp, Jon T
2018-05-09
To date, several data analysis methods have been used to estimate contingency strength, yet few studies have compared these methods directly. To compare the relative precision and sensitivity of four analysis methods (i.e., exhaustive event-based, nonexhaustive event-based, concurrent interval, concurrent+lag interval), we applied all methods to a simulated data set in which several response-dependent and response-independent schedules of reinforcement were programmed. We evaluated the degree to which contingency strength estimates produced from each method (a) corresponded with expected values for response-dependent schedules and (b) showed sensitivity to parametric manipulations of response-independent reinforcement. Results indicated both event-based methods produced contingency strength estimates that aligned with expected values for response-dependent schedules, but differed in sensitivity to response-independent reinforcement. The precision of interval-based methods varied by analysis method (concurrent vs. concurrent+lag) and schedule type (continuous vs. partial), and showed similar sensitivities to response-independent reinforcement. Recommendations and considerations for measuring contingencies are identified. © 2018 Society for the Experimental Analysis of Behavior.
SU-G-IeP4-13: PET Image Noise Variability and Its Consequences for Quantifying Tumor Hypoxia
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kueng, R; Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario; Manser, P
Purpose: The values in a PET image which represent activity concentrations of a radioactive tracer are influenced by a large number of parameters including patient conditions as well as image acquisition and reconstruction. This work investigates noise characteristics in PET images for various image acquisition and image reconstruction parameters. Methods: Different phantoms with homogeneous activity distributions were scanned using several acquisition parameters and reconstructed with numerous sets of reconstruction parameters. Images from six PET scanners from different vendors were analyzed and compared with respect to quantitative noise characteristics. Local noise metrics, which give rise to a threshold value defining themore » metric of hypoxic fraction, as well as global noise measures in terms of noise power spectra (NPS) were computed. In addition to variability due to different reconstruction parameters, spatial variability of activity distribution and its noise metrics were investigated. Patient data from clinical trials were mapped onto phantom scans to explore the impact of the scanner’s intrinsic noise variability on quantitative clinical analysis. Results: Local noise metrics showed substantial variability up to an order of magnitude for different reconstruction parameters. Investigations of corresponding NPS revealed reconstruction dependent structural noise characteristics. For the acquisition parameters, noise metrics were guided by Poisson statistics. Large spatial non-uniformity of the noise was observed in both axial and radial direction of a PET image. In addition, activity concentrations in PET images of homogeneous phantom scans showed intriguing spatial fluctuations for most scanners. The clinical metric of the hypoxic fraction was shown to be considerably influenced by the PET scanner’s spatial noise characteristics. Conclusion: We showed that a hypoxic fraction metric based on noise characteristics requires careful consideration of the various dependencies in order to justify its quantitative validity. This work may result in recommendations for harmonizing QA of PET imaging for multi-institutional clinical trials.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Paytan, Adina
Carbon (C) sequestration through fertilization of phytoplankton with micronutrients and enhancement of the absorption and retention of atmospheric C by ocean biota heavily depends on the efficiency of the “biological pump”. The long-term effectiveness of this strategy depends on a net transfer of C from the upper ocean-atmosphere system to the deep ocean where the C is removed from contact with the atmosphere for an extended period of time. This C removal can be equated to the amount of C fixation by phytoplankton minus the C cycling and regeneration in the euphotic zone. If the regeneration efficiency is increased, thenmore » despite increased C fixation, no net loss (sequestration) of C will result. A reduction in cycling efficiency in the euphotic zone, on the other hand, will increase the effectiveness of the “biological pump” and thus C sequestration. The degree of organic matter biodegradation and recycling depends on the “reactivity” of compounds synthesized by the biota, which in turn, is controlled by the structural characteristic of these compounds. There is considerable evidence that different phytoplankton taxa differ substantially in their biogeochemical characteristics and it is likely that the relative abundance of different compounds synthesized by these distinct taxa, and even within each group at different growth conditions, will differ too. This variability in biosynthesis and thus abundance of a wide range of organic compounds in the water column would lend itself to different susceptibility for biodegradation and regeneration. Knowledge of the distribution of various organic matter structural groups synthesized by distinct taxa, the dependence of the organic matter compound classes on different growth conditions (temperature, light, nutrients) and the selective susceptibility of these compound to regeneration is crucial for estimating the potential for rapid regeneration in the euphotic zone, and thus the effectiveness of the “biological pump”.« less
Measuring change in quality of life: bias in prospective and retrospective evaluation.
Blome, Christine; Augustin, Matthias
2015-01-01
Treatment effects on health-related quality of life (QOL) often differ depending on whether they are measured prospectively (before and after treatment) or retrospectively (after treatment only). These two approaches can be subject to different sorts of bias: Prospective evaluations may be biased by scale recalibration (a changed understanding of the response scale), and retrospective evaluations may be biased by recall bias (a wrong assessment of former QOL). On the basis of an analysis of the literature, we present an overview on possible biases in prospective and retrospective measurement of QOL and how these biases are named and defined in the literature. The definitions of different biases are inconsistent. Many authors do not clearly distinguish measurement bias from true change. Furthermore, some consider only scale recalibration or only recall bias. Much of the current discussion on bias in prospective and retrospective QOL measurement suffers from unclear definitions, especially of "response shift" and "recall bias," or from neglecting one of the possible biases. We suggest more elaborate definitions for different types of bias and recommend taking both kinds of bias into consideration when measuring change in QOL. The relevance of the different biases depends on the type of study, and so either prospective or retrospective assessment may be more appropriate. Copyright © 2015. Published by Elsevier Inc.
Critical considerations about the use of poverty measures in the study of cognitive development.
Lipina, Sebastián J
2017-06-01
Developmental psychology and developmental cognitive neuroscience generated evidence at different levels of analysis about the influences of poverty on neurocognitive development (i.e., molecular, neural activation, cognition, behaviour). In addition, different individual and environmental factors were identified as mediators of such influences. Such a complexity is also illustrated through the many poverty conceptual and operational definitions generated by social, human and health sciences. However, to establish the causal relationships between the different factors of poverty and neurocognitive outcomes is still an issue under construction. Most studies of this area apply classic unidimensional poverty indicators such as income and maternal education. Nonetheless, this approach does not take into adequate consideration the variability of neurocognitive outcomes depending on the type of poverty measures, and the dynamic nature of changes during development. This creates a virtual underestimation of the complexity imposed by the involved mediating mechanisms. The scientific and policy implications of this underestimation include the risk of not adequately addressing children rights and developmental opportunities. This article proposes to explore such scenario, which is necessary for the reconsideration of the criteria used to analyse the influences of poverty on child development in general and neurocognitive development in particular. © 2016 International Union of Psychological Science.
Bressler, David W.; Fortenbaugh, Francesca C.; Robertson, Lynn C.; Silver, Michael A.
2013-01-01
Endogenous visual spatial attention improves perception and enhances neural responses to visual stimuli at attended locations. Although many aspects of visual processing differ significantly between central and peripheral vision, little is known regarding the neural substrates of the eccentricity dependence of spatial attention effects. We measured amplitudes of positive and negative fMRI responses to visual stimuli as a function of eccentricity in a large number of topographically-organized cortical areas. Responses to each stimulus were obtained when the stimulus was attended and when spatial attention was directed to a stimulus in the opposite visual hemifield. Attending to the stimulus increased both positive and negative response amplitudes in all cortical areas we studied: V1, V2, V3, hV4, VO1, LO1, LO2, V3A/B, IPS0, TO1, and TO2. However, the eccentricity dependence of these effects differed considerably across cortical areas. In early visual, ventral, and lateral occipital cortex, attentional enhancement of positive responses was greater for central compared to peripheral eccentricities. The opposite pattern was observed in dorsal stream areas IPS0 and putative MT homolog TO1, where attentional enhancement of positive responses was greater in the periphery. Both the magnitude and the eccentricity dependence of attentional modulation of negative fMRI responses closely mirrored that of positive responses across cortical areas. PMID:23562388
Extreme precipitation response to climate perturbations in an atmospheric mesoscale model
NASA Astrophysics Data System (ADS)
Attema, Jisk J.; Loriaux, Jessica M.; Lenderink, Geert
2014-01-01
Observations of extreme (sub-)hourly precipitation at mid-latitudes show a large dependency on the dew point temperature often close to 14% per degree—2 times the dependency of the specific humidity on dew point temperature which is given by the Clausius-Clapeyron (CC) relation. By simulating a selection of 11 cases over the Netherlands characterized by intense showers, we investigate this behavior in the non-hydrostatic weather prediction model Harmonie at a resolution of 2.5 km. These experiments are repeated using perturbations of the atmospheric profiles of temperature and humidity: (i) using an idealized approach with a 2° warmer (colder) atmosphere assuming constant relative humidity, and (ii) using changes in temperature and humidity derived from a long climate change simulation at 2° global warming. All perturbations have a difference in the local dew point temperature compared to the reference of approximately 2°. Differences are considerable between the cases, with dependencies ranging from almost zero to an increase of 18% per degree rise of the dew point temperature. On average however, we find an increase of extreme precipitation intensity of 11% per degree for the idealized perturbation, and 9% per degree for the climate change perturbation. For the most extreme events these dependencies appear to approach a rate of 11-14% per degree, in closer agreement with the observed relation.
Prieto, Iván; Martínez-Tillería, Karina; Martínez-Manchego, Luis; Montecinos, Sonia; Pugnaire, Francisco I; Squeo, Francisco A
2010-08-01
Hydraulic lift (HL) is the passive movement of water through the roots from deep wet to dry shallow soil layers when stomata are closed. HL has been shown in different ecosystems and species, and it depends on plant physiology and soil properties. In this study we explored HL patterns in several arid land shrubs, and developed a simple model to simulate the temporal evolution and magnitude of HL during a soil drying cycle under relatively stable climatic conditions. This model was then used to evaluate the influence of soil texture on the quantity of water lifted by shrubs in different soil types. We conducted transpiration suppression experiments during spring 2005 in Chile and spring 2008 in Spain on five shrub species that performed HL, Flourensia thurifera, Senna cumingii and Pleocarphus revolutus (Chile), Retama sphaerocarpa and Artemisia barrelieri (Spain). Shrubs were covered with a black, opaque plastic fabric for a period of 48-72 h, and soil water potential was recorded at different depths under the shrubs. While the shrubs remained covered, water potential continuously increased in shallow soil layers until the cover was removed. The model output indicated that the amount of water lifted by shrubs is heavily dependent on soil texture, as shrubs growing in loamy soils redistributed up to 3.6 times more water than shrubs growing on sandy soils. This could be an important consideration for species growing in soils with different textures, as their ability to perform HL would be context dependent.
Differences in time-dependent mechanical properties between extruded and molded hydrogels
Ersumo, N; Witherel, CE; Spiller, KL
2016-01-01
The mechanical properties of hydrogels used in biomaterials and tissue engineering applications are critical determinants of their functionality. Despite the recent rise of additive manufacturing, and specifically extrusion-based bioprinting, as a prominent biofabrication method, comprehensive studies investigating the mechanical behavior of extruded constructs remain lacking. To address this gap in knowledge, we compared the mechanical properties and swelling properties of crosslinked gelatin-based hydrogels prepared by conventional molding techniques or by 3D bioprinting using a BioBots Beta pneumatic extruder. A preliminary characterization of the impact of bioprinting parameters on construct properties revealed that both Young's modulus and optimal extruding pressure increased with polymer content, and that printing resolution increased with both printing speed and nozzle gauge. High viability (>95%) of encapsulated NIH 3T3 fibroblasts confirmed the cytocompatibility of the construct preparation process. Interestingly, the Young's moduli of extruded and molded constructs were not different, but extruded constructs did show increases in both the rate and extent of time-dependent mechanical behavior observed in creep. Despite similar polymer densities, extruded hydrogels showed greater swelling over time compared to molded hydrogels, suggesting that differences in creep behavior derived from differences in microstructure and fluid flow. Because of the crucial roles of time-dependent mechanical properties, fluid flow, and swelling properties on tissue and cell behavior, these findings highlight the need for greater consideration of the effects of the extrusion process on hydrogel properties. PMID:27550945
Excitation of surface plasmons in Al-coated SNOM tips
NASA Astrophysics Data System (ADS)
Palm, Viktor; Rähn, Mihkel; Jäme, Joonas; Hizhnyakov, Vladimir
2012-10-01
The mesoscopic effect of spectral modulation occurring due to the interference of two photonic fiber modes filtered out by a metal-coated SNOM tip is used to observe the surface plasmon polariton (SPP) excitation in SNOM tips. In a spectrum of the broadband light transmitted by a SNOM tip a region of highly regular spectral modulation can be found, indicating the spectral interval in which only two photonic modes (apparently HE11 and TM01) are transmitted with significant and comparable amplitudes. The modulation period yields the value of optical path difference (OPD) for this pair of modes. Due to the multimode fiber's inherent modal dispersion, this OPD value depends linearly on the fiber tail length l. An additional contribution to OPD can be generated in a metal-coated SNOM tip due to a mode-dependent photon-plasmon coupling strength resulting in generation of SPPs with different propagation velocities. For an Al-coated 200 nm SNOM tip spectra of transmitted light have been registered for ten different l values. An extrapolation of the linear OPD (l) dependence to l=0 yields a significant residual OPD value, indicating according to our theoretical considerations a mode-selective SPP excitation in the metal-coated tip. The modal dispersion is shown to switch its sign in the SNOM tip. First results of analogous experiments with an Al-coated 150 nm SNOM tip confirm our conclusions.
Wissmann, F; Reginatto, M; Möller, T
2010-09-01
The problem of finding a simple, generally applicable description of worldwide measured ambient dose equivalent rates at aviation altitudes between 8 and 12 km is difficult to solve due to the large variety of functional forms and parametrisations that are possible. We present an approach that uses Bayesian statistics and Monte Carlo methods to fit mathematical models to a large set of data and to compare the different models. About 2500 data points measured in the periods 1997-1999 and 2003-2006 were used. Since the data cover wide ranges of barometric altitude, vertical cut-off rigidity and phases in the solar cycle 23, we developed functions which depend on these three variables. Whereas the dependence on the vertical cut-off rigidity is described by an exponential, the dependences on barometric altitude and solar activity may be approximated by linear functions in the ranges under consideration. Therefore, a simple Taylor expansion was used to define different models and to investigate the relevance of the different expansion coefficients. With the method presented here, it is possible to obtain probability distributions for each expansion coefficient and thus to extract reliable uncertainties even for the dose rate evaluated. The resulting function agrees well with new measurements made at fixed geographic positions and during long haul flights covering a wide range of latitudes.
Nilsen, Bente B; Yngve, Agneta; Sjöberg, Agneta; Moraeus, Lotta; Lissner, Lauren; Werner, Bo
2016-10-01
The study compared how four different growth references determined the prevalence of thinness and overweight, based on height and weight measurements from a nationally representative sample of Swedish children from seven to nine years of age. The height and weight measurements of 4518 Swedish schoolchildren aged seven to nine years were carried out in 2008 using a standardised protocol. The prevalence of different degrees of thinness and overweight was calculated using international growth references from the World Health Organization, the International Obesity Task Force and two Swedish growth references from Werner and Karlberg. Depending on which growth reference we used, the prevalence of different degrees of thinness varied from 7.5% to 16.9% for the boys and 6.9% to 13.7% for the girls, while the prevalence of overweight, including obesity and severe obesity, varied from 16.5% to 25.7% for the boys and 18.2 to 25.2% for the girls. There were also significant gender differences depending on the growth reference we used. Using four different growth references, two international and two Swedish, produced wide variations in the prevalence of thinness and overweight, together with significant gender differences. In the absence of a global definition, we need both national and international growth references. ©2016 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.
Performance and temperature dependencies of proton irradiated n/p and p/n GaAs and n/p silicon cells
NASA Technical Reports Server (NTRS)
Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.
1985-01-01
n/p homojunction GaAs cells are found to be more radiation resistant than p/n heteroface GaAs under 10 MeV proton irradiation. Both GaAs cell types outperform conventional silicon n/p cells under the same conditions. An increased temperature dependency of maximum power for the GaAs n/p cells is attributed to differences in Voc between the two GaAs cell types. These results and diffusion length considerations are consistent with the conclusion that p-type GaAs is more radiation resistant than n-type and therefore that the n/p configuration is possibly favored for use in the space radiation environment. However, it is concluded that additional work is required in order to choose between the two GaAs cell configurations.
Performance and temperature dependencies of proton irradiated n/p GaAs and n/p silicon cells
NASA Technical Reports Server (NTRS)
Weinberg, I.; Swartz, C. K.; Hart, R. E., Jr.
1985-01-01
The n/p homojunction GaAs cell is found to be more radiation resistant than p/nheteroface GaAs under 10 MeV proton irradiation. Both GaAs cell types outperform conventional silicon n/p cells under the same conditions. An increase temperature dependency of maximum power for the GaAs n/p cells is attributed largely to differences in Voc between the two GaAs cell types. These results and diffusion length considerations are consistent with the conclusion that p-type GaAs is more radiation resistant than n-type and therefore that the n/p configuration is possibly favored for use in the space radiation environment. However, it is concluded that additional work is required in order to choose between the two GaAs cell configurations.
Nikiyan, Hike; Vasilchenko, Alexey; Deryabin, Dmitry
2010-01-01
The effect of a relative humidity (RH) in a range of 93–65% on morphological and elastic properties of Bacillus cereus and Escherichia coli cells was evaluated using atomic force microscopy. It is shown that gradual dehumidification of bacteria environment has no significant effect on cell dimensional features and considerably decreases them only at 65% RH. The increasing of the bacteria cell wall roughness and elasticity occurs at the same time. Observed changes indicate that morphological properties of B. cereus are rather stable in wide range of relative humidity, whereas E. coli are more sensitive to drying, significantly increasing roughness and stiffness parameters at RH ≤ 84% RH. It is discussed the dependence of the response features on differences in cell wall structure of gram-positive and gram-negative bacterial cells. PMID:20652040
Stefl, Martin; Kułakowska, Anna; Hof, Martin
2009-08-05
A new (to our knowledge) robust approach for the determination of lateral diffusion coefficients of weakly bound proteins is applied for the phosphatidylserine specific membrane interaction of bovine prothrombin. It is shown that z-scan fluorescence correlation spectroscopy in combination with pulsed interleaved dual excitation allows simultaneous monitoring of the lateral diffusion of labeled protein and phospholipids. Moreover, from the dependencies of the particle numbers on the axial sample positions at different protein concentrations phosphatidylserine-dependent equilibrium dissociation constants are derived confirming literature values. Increasing the amount of membrane-bound prothrombin retards the lateral protein and lipid diffusion, indicating coupling of both processes. The lateral diffusion coefficients of labeled lipids are considerably larger than the simultaneously determined lateral diffusion coefficients of prothrombin, which contradicts findings reported for the isolated N-terminus of prothrombin.
Harms, H; Zehnder, A J
1994-01-01
Dibenzofuran uptake-associated kinetic parameters of suspended and attached Sphingomonas sp. strain HH19k cells were compared. The suspended cells were studied in a batch system, whereas glass beads in percolated columns were used as the solid support for attached cells. The maximum specific activities of cells in the two systems were the same. The apparent half-maximum uptake rate-associated concentrations (Kt') of attached cells, however, were considerably greater than those of suspended cells and depended on cell density and on percolation velocity. A mathematical model was developed to explain the observed differences in terms of substrate transport to the cells. This model was based on the assumptions that the intrinsic half-maximum uptake rate-associated concentration (Kt) was unchanged and that deviations of Kt' from Kt resulted from the stereometry and the hydrodynamics around the cells. Our calculations showed that (i) diffusion to suspended cells and to single attached cells is efficient and therefore only slightly affects Kt'; (ii) diffusion to cells located on crowded surfaces is considerably lower than that to single attached cells and greatly increases Kt', which depends on the cell density; (iii) the convective-diffusive transport to attached cells that occurs in a percolated column is influenced by the liquid flow and results in dependency of Kt' on the flow rate; and (iv) higher specific affinity of cells correlates with higher susceptibility to diffusion limitation. Properties of the experimental system which limited quantitative proof of exclusively transport-controlled variations of Kt' are discussed. PMID:8085817
Audesirk, T; Audesirk, G; Ferguson, C; Shugarts, D
1991-01-01
Lead exposure has devastating effects on the developing nervous system, and has been implicated in variety of behavioral and cognitive deficits as well as neural morphological abnormalities. Since lead impacts many calcium-dependent processes, one likely mechanism of lead toxicity is its disruption of calcium dependent processes, among which is neuronal differentiation. We investigated the effects of inorganic lead on survival and several parameters of differentiation of cultured neurons. Three different cell types were used: Rat hippocampal neurons (a primary CNS cell type), B50 rat neuroblastoma cells (a transformed CNS-derived cell line), and N1E-115 mouse neuroblastoma cells (a transformed peripherally-derived cell line). Lead concentrations ranged from low nM to 1 mM. Lead effects differed considerably among the three cell types, with B50 cells least affected. Lead effects were generally multimodal, with fewest effects observed at intermediate concentrations. Lead inhibited neurite initiation in hippocampal neurons, but stimulated initiation in N1E-115 cells. In those cells that differentiated, lead increased dendrite numbers in hippocampal neurons and neurite numbers in N1E-115 cells. Lead exposure increased both the length and the degree of branching of axons in hippocampal neurons and the length of neurites in N1E-115 cells. We hypothesize that lead impacts multiple regulatory processes that influence neuron survival and differentiation, and that its effects show differing dose-dependencies. The differing responses of the different cell types to lead suggests that differentiation may be regulated in different ways by the three types of cells. Alternatively, or additionally, the cell types may differ in their ability to compensate for, sequester, or expel lead.
Red-light-induced positive phototropism in Arabidopsis roots
NASA Technical Reports Server (NTRS)
Ruppel, N. J.; Hangarter, R. P.; Kiss, J. Z.
2001-01-01
The interaction between light and gravity is critical in determining the final form of a plant. For example, the competing activities of gravitropism and phototropism can determine the final orientation of a stem or root. The results reported here indicate that, in addition to the previously described blue-light-dependent negative phototropic response in roots, roots of Arahidopsis thaliana (L.) Heynh. display a previously unknown red-light-dependent positive phototropic response. Both phototropic responses in roots are considerably weaker than the graviresponse, which often masks phototropic curvature. However, through the use of mutant strains with impaired gravitropism, we were able to identify a red-light-dependent positive phototropic response in Arabidopsis roots. The red-induced positive phototropic response is considerably weaker than the blue-light response and is barely detectable in plants with a normal gravitropic response.
Red-light-induced positive phototropism in Arabidopsis roots.
Ruppel, N J; Hangarter, R P; Kiss, J Z
2001-02-01
The interaction between light and gravity is critical in determining the final form of a plant. For example, the competing activities of gravitropism and phototropism can determine the final orientation of a stem or root. The results reported here indicate that, in addition to the previously described blue-light-dependent negative phototropic response in roots, roots of Arahidopsis thaliana (L.) Heynh. display a previously unknown red-light-dependent positive phototropic response. Both phototropic responses in roots are considerably weaker than the graviresponse, which often masks phototropic curvature. However, through the use of mutant strains with impaired gravitropism, we were able to identify a red-light-dependent positive phototropic response in Arabidopsis roots. The red-induced positive phototropic response is considerably weaker than the blue-light response and is barely detectable in plants with a normal gravitropic response.
2015-01-01
Chiral polychlorinated biphenyls (PCBs) display variable atropisomeric enrichment in wildlife and animal models, especially at higher trophic levels. These differences in PCBs’ chiral signatures are, at least in part, due to species-dependent oxidation of PCBs to hydroxylated PCB metabolites (OH-PCBs). Here, we investigate the hypothesis that the cytochrome P450 (P450) enzyme-mediated oxidation of chiral PCBs results in species-dependent differences in the chiral signatures of OH-PCBs (i.e., the direction and extent of OH-PCBs’ atropisomeric enrichment). To investigate this hypothesis, we incubated PCB 136, a representative chiral PCB, with pooled human liver microsomes (HLMs) or liver microsomes from male guinea pig, hamster, monkey, mouse, and rabbit or female dog and determined average profiles and chiral signatures of the OH-PCBs. 2,2′,3,3′,6,6′-Hexachlorobiphenyl-4-ol (4–136) was the major metabolite in incubations with HLMs and monkey and rabbit microsomes. 2,2′,3,3′,6,6′-Hexachlorobiphenyl-5-ol (5–136) was the major metabolite formed by microsomes from all other species. Both 4–136 and 5–136 were formed atropselectively in all microsomal incubations; however, the direction and extent of the atropisomeric enrichment of both OH-PCB metabolites showed considerable differences across microsomal preparations obtained from different species. These differences in OH-PCBs’ atropisomeric enrichment may not only be toxicologically relevant but may also be useful to study sources and transport of OH-PCBs in the environment. PMID:24467194
Assessing dimensions of nicotine dependence
Piper, Megan E.; McCarthy, Danielle E.; Bolt, Daniel M.; Smith, Stevens S.; Lerman, Caryn; Benowitz, Neal; Fiore, Michael C.; Baker, Timothy B.
2008-01-01
Considerable research, ranging from survey to clinical to genetic, has utilized traditional measures of tobacco dependence, such as the Fagerstrom Test of Nicotine Dependence (FTND) and the Diagnostic and Statistical Manual (DSM-IV) criteria, that focus on endpoint definitions of tobacco dependence such as heavy smoking, time to first cigarette in the morning, and smoking despite consequences. In an effort to better understand possible theories and mechanisms underlying tobacco dependence, which could be used to improve treatment and research, two multidimensional measures of tobacco dependence have been developed: the Nicotine Dependence Syndrome Scale (NDSS) and the Wisconsin Inventory of Smoking Dependence Motives (WISDM). This research used data from three randomized smoking cessation trials to examine the internal consistency and validity (convergent, concurrent and predictive) of these scales, relative to each other and the traditional measures. Results reveal that NDSS and WISDM subscales are related to important dependence criteria, but in a heterogeneous fashion. The data suggest that there are important underlying mechanisms or motives that are significantly related to different important outcomes, such as withdrawal and cessation. The FTND was most strongly related to abstinence at 1 week and 6 months post-quit, whereas the WISDM Tolerance subscale was most strongly related to abstinence at the end of treatment. The NDSS Priority subscale was consistently predictive of outcome at all three follow-up time points. There is also evidence that WISDM subscales are related to a biomarker of the rate of nicotine metabolism. PMID:18584464
Scaling effects in direct shear tests
Orlando, A.D.; Hanes, D.M.; Shen, H.H.
2009-01-01
Laboratory experiments of the direct shear test were performed on spherical particles of different materials and diameters. Results of the bulk friction vs. non-dimensional shear displacement are presented as a function of the non-dimensional particle diameter. Simulations of the direct shear test were performed using the Discrete Element Method (DEM). The simulation results show Considerable differences with the physical experiments. Particle level material properties, such as the coefficients of static friction, restitution and rolling friction need to be known a priori in order to guarantee that the simulation results are an accurate representation of the physical phenomenon. Furthermore, laboratory results show a clear size dependency on the results, with smaller particles having a higher bulk friction than larger ones. ?? 2009 American Institute of Physics.
Charged Particle Diffusion in Isotropic Random Static Magnetic Fields
NASA Astrophysics Data System (ADS)
Subedi, P.; Sonsrettee, W.; Matthaeus, W. H.; Ruffolo, D. J.; Wan, M.; Montgomery, D.
2013-12-01
Study of the transport and diffusion of charged particles in a turbulent magnetic field remains a subject of considerable interest. Research has most frequently concentrated on determining the diffusion coefficient in the presence of a mean magnetic field. Here we consider Diffusion of charged particles in fully three dimensional statistically isotropic magnetic field turbulence with no mean field which is pertinent to many astrophysical situations. We classify different regions of particle energy depending upon the ratio of Larmor radius of the charged particle to the characteristic outer length scale of turbulence. We propose three different theoretical models to calculate the diffusion coefficient each applicable to a distinct range of particle energies. The theoretical results are compared with those from computer simulations, showing very good agreement.
Atmospheric heat engines on earth and Mars
NASA Astrophysics Data System (ADS)
Philip, J. R.
1987-06-01
The character of the earth's atmospheric heat engine depends, inter alia, on the relatively tight linkage between surface fluxes of energy and of H2O. On Mars, on the other hand, H2O-based latent heat fluxes are only a trivial fraction of total surface energy fluxes, and the dominant component of the working fluid is CO2. These considerations are made quantitative through evaluation of Lambda, the equivalent temperature excess at the surface for a particular component of the working fluid. The very different values (and latitudinal distribution) of Lambda on the two planets signalize vividly their different meteorology. Preliminary study of the climatology of Lambda on earth brings out, in particular, the tightness of the H2O-energy linkage in the tropics.
Transient Micromotors That Disappear When No Longer Needed.
Chen, Chuanrui; Karshalev, Emil; Li, Jinxing; Soto, Fernando; Castillo, Roxanne; Campos, Isaac; Mou, Fangzhi; Guan, Jianguo; Wang, Joseph
2016-11-22
Transient self-destroyed micromotors that autonomously disappear in biological media at controlled rates upon completing their task, without leaving a toxic residue, are presented. The propulsion and degradation characteristics of the self-destroyed Mg/ZnO, Mg/Si, and Zn/Fe Janus micromotors and single-component Zn micromotors are described. The degradation of the Janus micromotors relies on the different corrosion rates of their core-shell components. Inductively coupled plasma optical emission spectrometry measurements are used to probe the time-dependent degradation of the different constituents of the micromotors. The toxicity of the transient micromotors is discussed toward their potential use in biomedical applications. This concept of transient micromotors offers considerable potential for diverse practical applications in the near future.
Ramirez-Zamora, Adolfo; Smith, Heather; Kumar, Vignessh; Prusik, Julia; Phookan, Sujoy; Pilitsis, Julie G
2016-01-01
Although thalamic deep brain stimulation (DBS) has been established as an effective therapy for refractory tremor in Parkinson's disease and essential tremor, reports investigating the efficacy of posterior subthalamic area (PSA) DBS for severe, debilitating tremors continue to emerge. However, questions regarding the optimal anatomical target, surgical approach, programming paradigms and effectiveness compared to other targets remain. In this report, we aimed to review the current literature to assess different stereotactic techniques, anatomical considerations, adverse effects and stimulation settings in PSA DBS. A comprehensive literature review was performed searching for articles discussing tremors and PSA stimulation. We performed a quantitative analysis comparing different DBS tremor targets. Tremor improvement is consistently documented in most reports with an average reduction in tremor of 79% depending on the specific tremor syndrome. Tremor benefit in patients with multiple sclerosis (MS) tremor was significantly higher than for other stimulation targets. Transient paresthesias, imbalance, dizziness and dysarthria are the most common side effects with PSA DBS. PSA DBS is an effective and safe treatment for tremor control and should be considered in patients with refractory tremors with associated cerebellar or dystonic features, proximal tremors and MS tremor. © 2016 S. Karger AG, Basel.
Power considerations for λ inflation factor in meta-analyses of genome-wide association studies.
Georgiopoulos, Georgios; Evangelou, Evangelos
2016-05-19
The genomic control (GC) approach is extensively used to effectively control false positive signals due to population stratification in genome-wide association studies (GWAS). However, GC affects the statistical power of GWAS. The loss of power depends on the magnitude of the inflation factor (λ) that is used for GC. We simulated meta-analyses of different GWAS. Minor allele frequency (MAF) ranged from 0·001 to 0·5 and λ was sampled from two scenarios: (i) random scenario (empirically-derived distribution of real λ values) and (ii) selected scenario from simulation parameter modification. Adjustment for λ was considered under single correction (within study corrected standard errors) and double correction (additional λ corrected summary estimate). MAF was a pivotal determinant of observed power. In random λ scenario, double correction induced a symmetric power reduction in comparison to single correction. For MAF 1·2 and MAF >5%. Our results provide a quick but detailed index for power considerations of future meta-analyses of GWAS that enables a more flexible design from early steps based on the number of studies accumulated in different groups and the λ values observed in the single studies.
Yang, Yao Bin; Sharifi, Vida; Swithenbank, Jim
2008-11-01
Fluidised bed combustor (FBC) is one of the key technologies for sewage sludge incineration. In this paper, a mathematical model is developed for the simulation of a large-scale sewage sludge incineration plant. The model assumes the bed consisting of a fast-gas phase, an emulsion phase and a fuel particle phase with specific consideration for thermally-thick fuel particles. The model further improves over previous works by taking into account throughflow inside the bubbles as well as the floating and random movement of the fuel particles inside the bed. Validation against both previous lab-scale experiments and operational data of a large-scale industrial plant was made. Calculation results indicate that combustion split between the bed and the freeboard can range from 60/40 to 90/10 depending on the fuel particle distribution across the bed height under the specific conditions. The bed performance is heavily affected by the variation in sludge moisture level. The response time to variation in feeding rate is different for different parameters, from 6 min for outlet H2O, 10 min for O2, to 34 min for bed temperature.
Varaksin, Anatoly N; Katsnelson, Boris A; Panov, Vladimir G; Privalova, Larisa I; Kireyeva, Ekaterina P; Valamina, Irene E; Beresneva, Olga Yu
2014-02-01
Rats were exposed intraperitoneally (3 times a week up to 20 injections) to either Cadmium and Lead salts in doses equivalent to their 0.05 LD50 separately or combined in the same or halved doses. Toxic effects were assessed by more than 40 functional, biochemical and morphometric indices. We analysed the results obtained aiming at determination of the type of combined toxicity using either common sense considerations based on descriptive statistics or two mathematical models based (a) on ANOVA and (b) on Mathematical Theory of Experimental Design, which correspond, respectively, to the widely recognised paradigms of effect additivity and dose additivity. Nevertheless, these approaches have led us unanimously to the following conclusions: (1) The above paradigms are virtually interchangeable and should be regarded as different methods of modelling the combined toxicity rather than as reflecting fundamentally differing processes. (2) Within both models there exist not merely three traditionally used types of combined toxicity (additivity, subadditivity and superadditivity) but at least 10 variants of it depending on exactly which effect is considered and on its level, as well as on the dose levels and their ratio. Copyright © 2013 Elsevier Ltd. All rights reserved.
Yan, Xu; Bishop, David J.
2018-01-01
Gene expression analysis by quantitative PCR in skeletal muscle is routine in exercise studies. The reproducibility and reliability of the data fundamentally depend on how the experiments are performed and interpreted. Despite the popularity of the assay, there is a considerable variation in experimental protocols and data analyses from different laboratories, and there is a lack of consistency of proper quality control steps throughout the assay. In this study, we present a number of experiments on various steps of quantitative PCR workflow, and demonstrate how to perform a quantitative PCR experiment with human skeletal muscle samples in an exercise study. We also tested some common mistakes in performing qPCR. Interestingly, we found that mishandling of muscle for a short time span (10 mins) before RNA extraction did not affect RNA quality, and isolated total RNA was preserved for up to one week at room temperature. Demonstrated by our data, use of unstable reference genes lead to substantial differences in the final results. Alternatively, cDNA content can be used for data normalisation; however, complete removal of RNA from cDNA samples is essential for obtaining accurate cDNA content. PMID:29746477
Aeroelastic simulation of higher harmonic control
NASA Technical Reports Server (NTRS)
Robinson, Lawson H.; Friedmann, Peretz P.
1994-01-01
This report describes the development of an aeroelastic analysis of a helicopter rotor and its application to the simulation of helicopter vibration reduction through higher harmonic control (HHC). An improved finite-state, time-domain model of unsteady aerodynamics is developed to capture high frequency aerodynamic effects. An improved trim procedure is implemented which accounts for flap, lead-lag, and torsional deformations of the blade. The effect of unsteady aerodynamics is studied and it is found that its impact on blade aeroelastic stability and low frequency response is small, but it has a significant influence on rotor hub vibrations. Several different HHC algorithms are implemented on a hingeless rotor and their effectiveness in reducing hub vibratory shears is compared. All the controllers are found to be quite effective, but very differing HHC inputs are required depending on the aerodynamic model used. Effects of HHC on rotor stability and power requirements are found to be quite small. Simulations of roughly equivalent articulated and hingeless rotors are carried out, and it is found that hingeless rotors can require considerably larger HHC inputs to reduce vibratory shears. This implies that the practical implementation of HHC on hingeless rotors might be considerably more difficult than on articulated rotors.
Image motion environments: background noise for movement-based animal signals.
Peters, Richard; Hemmi, Jan; Zeil, Jochen
2008-05-01
Understanding the evolution of animal signals has to include consideration of the structure of signal and noise, and the sensory mechanisms that detect the signals. Considerable progress has been made in understanding sounds and colour signals, however, the degree to which movement-based signals are constrained by the particular patterns of environmental image motion is poorly understood. Here we have quantified the image motion generated by wind-blown plants at 12 sites in the coastal habitat of the Australian lizard Amphibolurus muricatus. Sampling across different plant communities and meteorological conditions revealed distinct image motion environments. At all locations, image motion became more directional and apparent speed increased as wind speeds increased. The magnitude of these changes and the spatial distribution of image motion, however, varied between locations probably as a function of plant structure and the topographic location. In addition, we show that the background motion noise depends strongly on the particular depth-structure of the environment and argue that such micro-habitat differences suggest specific strategies to preserve signal efficacy. Movement-based signals and motion processing mechanisms, therefore, may reveal the same type of habitat specific structural variation that we see for signals from other modalities.
Time dependence of composite shrinkage using halogen and LED light curing.
Uhl, Alexander; Mills, Robin W; Rzanny, Angelika E; Jandt, Klaus D
2005-03-01
The polymerization shrinkage of light cured dental composites presents the major drawback for these aesthetically adaptable restorative materials. LED based light curing technology has recently become commercially available. Therefore, the aim of the present study was to investigate if there was a statistically significant difference in linear and volumetric composite shrinkage strain if a LED LCU is used for the light curing process rather than a conventional halogen LCU. The volumetric shrinkage strain was determined using the Archimedes buoyancy principle after 5, 10, 20, 40 s of light curing and after 120 s following the 40 s light curing time period. The linear shrinkage strain was determined with a dynamic mechanical analyzer for the composites Z100, Spectrum, Solitaire2 and Definite polymerized with the LCUs Trilight (halogen), Freelight I (LED) and LED63 (LED LCU prototype). The changes in irradiance and spectra of the LCUs were measured after 0, 312 and 360 min of duty time. In general there was no considerable difference in shrinkage of the composites Z100, Spectrum or Solitaire2 when the LED63 was used instead of the Trilight. There was, however, a statistically significant difference in shrinkage strain when the composite Definite was polymerized with the LED63 instead of the Trilight. The spectrum of the Trilight changed during the experiment considerably whereas the LED63 showed an almost constant light output. The Freelight I dropped considerably in irradiance and had to be withdrawn from the study because of technical problems. The composites containing only the photoinitiator camphorquinone showed similar shrinkage strain behaviour when a LED or halogen LCU is used for the polymerization. The irradiance of some LED LCUs can also decrease over time and should therefore be checked on a regular basis.
Fresnel zone considerations for reflection and scatter from refractive index irregularities
NASA Technical Reports Server (NTRS)
Doviak, R. J.; Zrnic, D. S.
1983-01-01
Several different echoing mechanisms are proposed to explain VHF/UHF scatter from clear air; (1) anisotropic scatter; (2) Fresnel reflection, and (3) Fresnel scatter, in order to account for the spatial (angle and range) and temporal dependence of the echoes. The term diffuse reflection describes the echoing mechanism when both scatter and reflection coexist. A unifying formulation is presented incorporating a statistical approach that embraces all mechanisms the above mechanisms and gives conditions under which reflection or scatter dominates. A distinction between Fraunhofer and Fresnel scatter and a criterion is presented under which Fresnel scatter is important.
Temperature Dependence of Photoluminescence in InGaAs/InP Strained MQW Heterostructures
NASA Technical Reports Server (NTRS)
Raisky, O. Y.; Wang, W. B.; Alfano, R. R.; Reynolds, C. L., Jr.; Swaminathan, V.
1996-01-01
Multiple quantum well (MQW) InGaAsP/InP heterostructure systems have been drawn considerable research interest in recent years due to its suitability for long wavelength optoelectronic devices. The performance of such devices is strongly affected by peculiarities of recombination processes in the quantum wells (QW). The goal of this study was to investigate the effect of barrier width on the radiative recombination of carriers. In our study, the photoluminescence spectra from InGaAsP/lnP MQW double heterostructures have been measured in the 77-290 K temperature range with different excitation intensities.
A case for poroelasticity in skeletal muscle finite element analysis: experiment and modeling.
Wheatley, Benjamin B; Odegard, Gregory M; Kaufman, Kenton R; Haut Donahue, Tammy L
2017-05-01
Finite element models of skeletal muscle typically ignore the biphasic nature of the tissue, associating any time dependence with a viscoelastic formulation. In this study, direct experimental measurement of permeability was conducted as a function of specimen orientation and strain. A finite element model was developed to identify how various permeability formulations affect compressive response of the tissue. Experimental and modeling results suggest the assumption of a constant, isotropic permeability is appropriate. A viscoelastic only model differed considerably from a visco-poroelastic model, suggesting the latter is more appropriate for compressive studies.
Mechanical behaviour of cerclage material consisting of silicon rubber.
Hinrichsen, G; Eberhardt, A; Springer, H
1979-09-01
Silicon rubber specimens of circular or rectangular cross-section (cross-section area between ca. 2 and 7 mm2) are used as cerclage bands. A series of commercial cerclage elements was investigated for mechanical characteristics, such as stress-strain behaviour and modulus of elasticity, using a tensile-testing machine. Large differences in these properties exist among the various specimens. Moreover, time-dependent effects, such as stress-relaxation, retardation, and creep, were analysed by the present investigations. One has to take into consideration that the initial length and stress of the cerclage band vary significantly with time after the operation.
Ontario dentists: 3. Radiographs prescribed in general practice.
Swan, E S; Lewis, D W
1993-01-01
In February 1991, a mail survey was used to poll a sample consisting of about 10 per cent of Ontario's general dentists. The data obtained provided information about the radiographs prescribed by dentists for five different patient types, which were described to the respondents. The per cent agreement between the radiographic procedures prescribed by Ontario dentists and the ADA-approved Center for Devices and Radiological Health (CDRH) guidelines ranged from three per cent to 79 per cent, depending on patient type and disease risk. For each patient and risk type, there was considerable variation in the radiographs prescribed.
[Dopamine agonists--clinical applications beyond Parkinson's disease].
Kuran, Włodzimierz
2007-01-01
Contemporary experience and results of clinical trials concerning dopamine agonist application in the treatment of many different diseases (apart from Parkinson's disease) are presented in the paper. A basic clinical recommendation for agonists is restless legs syndrome. In this syndrome almost all agonists give a considerable subjective and objective improvement. Treatment of atypical parkinsonism (MSA, PSP, CBD) in the majority of patients is ineffective. The author also presents promising results of treatment with agonists in such diverse diseases as hyperkinetic syndromes, cocaine dependence, drug-resistant depression and erectile dysfunction (apomorphine). Dopamine partial agonists (e.g. aripiprazol) are recommended in the modern treatment of schizophrenia.
Angular distribution of species in pulsed laser deposition of LaxCa1-xMnO3
NASA Astrophysics Data System (ADS)
Ojeda-G-P, Alejandro; Schneider, Christof W.; Döbeli, Max; Lippert, Thomas; Wokaun, Alexander
2015-05-01
The angular distribution of species from a La0.4Ca0.6MnO3 target irradiated with a 248 nm nanosecond pulsed laser was investigated by Rutherford backscattering spectrometry for four different Ar pressures. The film thickness angular distribution was also analyzed using profilometry. Depending on the background gas pressure, the target to substrate distance, and the angular location the film thickness and composition varies considerably. In particular the film composition could vary by up to 17% with respect to the composition of the target material.
Friction-term response to boundary-condition type in flow models
Schaffranek, R.W.; Lai, C.
1996-01-01
The friction-slope term in the unsteady open-channel flow equations is examined using two numerical models based on different formulations of the governing equations and employing different solution methods. The purposes of the study are to analyze, evaluate, and demonstrate the behavior of the term in a set of controlled numerical experiments using varied types and combinations of boundary conditions. Results of numerical experiments illustrate that a given model can respond inconsistently for the identical resistance-coefficient value under different types and combinations of boundary conditions. Findings also demonstrate that two models employing different dependent variables and solution methods can respond similarly for the identical resistance-coefficient value under similar types and combinations of boundary conditions. Discussion of qualitative considerations and quantitative experimental results provides insight into the proper treatment, evaluation, and significance of the friction-slope term, thereby offering practical guidelines for model implementation and calibration.
Trautz, Florian; Dreßler, Jan; Stassart, Ruth; Müller, Wolf; Ondruschka, Benjamin
2018-01-03
Immunohistochemistry (IHC) has become an integral part in forensic histopathology over the last decades. However, the underlying methods for IHC vary greatly depending on the institution, creating a lack of comparability. The aim of this study was to assess the optimal approach for different technical aspects of IHC, in order to improve and standardize this procedure. Therefore, qualitative results from manual and automatic IHC staining of brain samples were compared, as well as potential differences in suitability of common IHC glass slides. Further, possibilities of image digitalization and connected issues were investigated. In our study, automatic staining showed more consistent staining results, compared to manual staining procedures. Digitalization and digital post-processing facilitated direct analysis and analysis for reproducibility considerably. No differences were found for different commercially available microscopic glass slides regarding suitability of IHC brain researches, but a certain rate of tissue loss should be expected during the staining process.
Considerations for Bioassay Monitoring of Mixtures of Radionuclides
Klumpp, John; Waters, Tom; Bertelli, Luiz
2017-10-01
Complying with regulations for bioassay monitoring of radionuclide intakes is significantly more complex for mixtures than it is for pure radionuclides. Different constituents will naturally have different dose coefficients, be detectable at significantly different levels, and may require very different amounts of effort to bioassay. The ability to use certain constituents as surrogates for others will depend on how well characterized the mixture is, as well as whether the employee is also working with other radionuclides. This is further compounded by the fact that the composition of a mixture (or even of a pure radionuclide) is likely to change overmore » time. Internal dosimetrists must decide how best to monitor employees who work with radionuclide mixtures. In particular, they must decide which constituents should be monitored routinely, which constituents only need to be monitored in the case of an intake, and how to estimate doses based on intakes of monitored and unmonitored constituents.« less
Turbulent combustion in aluminum-air clouds for different scale explosion fields
NASA Astrophysics Data System (ADS)
Kuhl, Allen L.; Balakrishnan, Kaushik; Bell, John B.; Beckner, Vincent E.
2017-01-01
This paper explores "scaling issues" associated with Al particle combustion in explosions. The basic idea is the following: in this non-premixed combustion system, the global burning rate is controlled by rate of turbulent mixing of fuel (Al particles) with air. From similarity considerations, the turbulent mixing rates should scale with the explosion length and time scales. However, the induction time for ignition of Al particles depends on an Arrhenius function, which is independent of the explosion length and time. To study this, we have performed numerical simulations of turbulent combustion in unconfined Al-SDF (shock-dispersed-fuel) explosion fields at different scales. Three different charge masses were assumed: 1-g, 1-kg and 1-T Al-powder charges. We found that there are two combustion regimes: an ignition regime—where the burning rate decays as a power-law function of time, and a turbulent combustion regime—where the burning rate decays exponentially with time. This exponential dependence is typical of first order reactions and the more general concept of Life Functions that control the dynamics of evolutionary systems. Details of the combustion model are described. Results, including mean and rms profiles in combustion cloud and fuel consumption histories, are presented.
Karamzadeh, Razieh; Karimi-Jafari, Mohammad Hossein; Sharifi-Zarchi, Ali; Chitsaz, Hamidreza; Salekdeh, Ghasem Hosseini; Moosavi-Movahedi, Ali Akbar
2017-06-16
The human protein disulfide isomerase (hPDI), is an essential four-domain multifunctional enzyme. As a result of disulfide shuffling in its terminal domains, hPDI exists in two oxidation states with different conformational preferences which are important for substrate binding and functional activities. Here, we address the redox-dependent conformational dynamics of hPDI through molecular dynamics (MD) simulations. Collective domain motions are identified by the principal component analysis of MD trajectories and redox-dependent opening-closing structure variations are highlighted on projected free energy landscapes. Then, important structural features that exhibit considerable differences in dynamics of redox states are extracted by statistical machine learning methods. Mapping the structural variations to time series of residue interaction networks also provides a holistic representation of the dynamical redox differences. With emphasizing on persistent long-lasting interactions, an approach is proposed that compiled these time series networks to a single dynamic residue interaction network (DRIN). Differential comparison of DRIN in oxidized and reduced states reveals chains of residue interactions that represent potential allosteric paths between catalytic and ligand binding sites of hPDI.
An overview of polybrominated diphenyl ethers (PBDEs) in the marine environment
NASA Astrophysics Data System (ADS)
Lee, Hyo Jin; Kim, Gi Beum
2015-06-01
Polybrominated diphenyl ethers (PBDEs), which are used extensively as brominated flame retardants, are found ubiquitously in marine environments worldwide. In this paper, we review all available data on the occurrence and trends of PBDEs in marine environments. PBDE levels in different marine environmental compartments vary from nanograms per gram to micrograms per gram, and differ widely, depending on the exposed species and the collection site. The PBDE congener profiles in biota, which are dominated by the lower brominated congeners, such as BDE-47 and BDE-99, are different from those in sediments, where BDE-209 is dominant. Temporal trends in PBDE levels in sediment cores vary considerably, depending on the region or country studied, with possible correlations with the historic and current use of PBDEs. Low brominated BDE congeners have the potential for bioaccumulation in marine organisms, but BDE- 209 has a very low potential for bioaccumulating within the marine food web. The toxicological effects of PBDEs on marine organisms are largely unknown. However, PBDE isomers may be sufficient to elicit adverse effects in some marine organisms. Here, we discuss naturally occurring brominated diphenyl ethers and recommend further research to improve future monitoring.
Bae, Ye-Won; Lee, Soh Min; Kim, Kwang-Ok
2016-03-15
The introduction of ready-to-drink (RTD) green tea beverage has allowed diverse consumers to consume green teas and related products. Green tea that has been traditionally consumed for its delicate flavor characteristics is also widely consumed for its recognition as a healthy product. Because it is reported that age difference exists in consideration of health-related information, the objective of the study was to investigate how sensory and non-sensory factors, in particular health-related information, price and packaging, would affect the flavor acceptability of green tea beverages, depending on consumers' age and gender. Regardless of the product information, old consumers preferred products that provided an indication of health beneficial effect. On the other hand, young consumers tended to be influenced by extrinsic product information such as packaging, brand/manufacturer and/or price, though these consumers were not so much influenced by health beneficial information as were the old consumers. The findings of the study implied that the influence of non-sensory information such as health beneficial information in flavor liking differed depending mostly on consumers' age, and little on gender, for RTD green tea beverages. © 2015 Society of Chemical Industry.
Force field dependent solution properties of glycine oligomers
Drake, Justin A.
2015-01-01
Molecular simulations can be used to study disordered polypeptide systems and to generate hypotheses on the underlying structural and thermodynamic mechanisms that govern their function. As the number of disordered protein systems investigated with simulations increase, it is important to understand how particular force fields affect the structural properties of disordered polypeptides in solution. To this end, we performed a comparative structural analysis of Gly3 and Gly10 in aqueous solution from all-atom, microsecond MD simulations using the CHARMM 27 (C27), CHARMM 36 (C36), and Amber ff12SB force fields. For each force field, Gly3 and Gly10 were simulated for at least 300 ns and 1 μs, respectively. Simulating oligoglycines of two different lengths allows us to evaluate how force field effects depend on polypeptide length. Using a variety of structural metrics (e.g. end-to-end distance, radius of gyration, dihedral angle distributions), we characterize the distribution of oligoglycine conformers for each force field and show that each sample conformation space differently, yielding considerably different structural tendencies of the same oligoglycine model in solution. Notably, we find that C36 samples more extended oligoglycine structures than both C27 and ff12SB. PMID:25952623
Some Methodological Considerations in Researching the Family Career.
ERIC Educational Resources Information Center
White, James
Methodological issues which confront researchers using the concept of the family career include the selection of appropriate dependent variables; the efficacy of historical versus immediate effects; and scaling the family career (a proposed replacement for the "family life cycle"). The issue of which dependent variables should be…
Considerations on methodological challenges for water footprint calculations.
Thaler, S; Zessner, M; De Lis, F Bertran; Kreuzinger, N; Fehringer, R
2012-01-01
We have investigated how different approaches for water footprint (WF) calculations lead to different results, taking sugar beet production and sugar refining as examples. To a large extent, results obtained from any WF calculation are reflective of the method used and the assumptions made. Real irrigation data for 59 European sugar beet growing areas showed inadequate estimation of irrigation water when a widely used simple approach was used. The method resulted in an overestimation of blue water and an underestimation of green water usage. Dependent on the chosen (available) water quality standard, the final grey WF can differ up to a factor of 10 and more. We conclude that further development and standardisation of the WF is needed to reach comparable and reliable results. A special focus should be on standardisation of the grey WF methodology based on receiving water quality standards.
Zhang, Sijia; Gu, Bin; Zhang, Hongbin; Feng, Xi-Qiao; Pan, Rongying; Alamusi; Hu, Ning
2016-03-01
The propagation of Love waves in the structure consisting of a nanosized piezoelectric film and a semi-infinite elastic substrate is investigated in the present paper with the consideration of surface effects. In our analysis, surface effects are taken into account in terms of the surface elasticity theory and the electrically-shorted conditions are adopted on the free surface of the piezoelectric film and the interface between the film and the substrate. This work focuses on the new features in the dispersion relations of different modes due to surface effects. It is found that with the existence of surface effects, the frequency dispersion of Love waves shows the distinct dependence on the thickness and the surface constants when the film thickness reduces to nanometers. In general, phase velocities of all dispersion modes increase with the decrease of the film thickness and the increase of the surface constants. However, surface effects play different functions in the frequency dispersions of different modes, especially for the first mode dispersion. Moreover, different forms of Love waves are observed in the first mode dispersion, depending on the presence of the surface effects on the surface and the interface. Copyright © 2015 Elsevier B.V. All rights reserved.
Implications for social policy of variability in racial groups.
Helms, Janet E
2008-11-01
Social policy and federal and state legislation require the use of single cut scores when tests of cognitive ability, knowledge, or skills (CAKS) are used to make high-stakes assessment decisions, such as whether students or employees may be promoted. Rationales offered for the requirement are that cut scores provide objective standards and are fairer than using subjective criteria, such as racial group membership. It is argued that failure to consider threats to statistical conclusion validity, such as differences in variability between groups, obscures the differential impact of using a common cut score as the basis for highstakes decisions. Analyses of 40 Black and White samples revealed that (a) Whites might be considerably advantaged and Blacks might be considerably disadvantaged by the same cut score and (b) depending on where the cut score is set, decisions based on ratios of numbers of Whites numbers of Blacks might be fairer than use of CAKS test cut scores. Implications for assessment practice and social policy are discussed.
Bergmann, Lasse T.; Schlicht, Larissa; Meixner, Carmen; König, Peter; Pipa, Gordon; Boshammer, Susanne; Stephan, Achim
2018-01-01
Autonomous vehicles, though having enormous potential, face a number of challenges. As a computer system interacting with society on a large scale and human beings in particular, they will encounter situations, which require moral assessment. What will count as right behavior in such situations depends on which factors are considered to be both morally justified and socially acceptable. In an empirical study we investigated what factors people recognize as relevant in driving situations. The study put subjects in several “dilemma” situations, which were designed to isolate different and potentially relevant factors. Subjects showed a surprisingly high willingness to sacrifice themselves to save others, took the age of potential victims in a crash into consideration and were willing to swerve onto a sidewalk if this saved more lives. The empirical insights are intended to provide a starting point for a discussion, ultimately yielding societal agreement whereby the empirical insights should be balanced with philosophical considerations. PMID:29541023
Addressing Criticality in Rare Earth Elements via Permanent Magnets Recycling
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nlebedim, I. C.; King, A. H.
Rare earth elements (REEs) are critical for many advanced technologies and are faced with potential supply disruptions. Recycling of permanent magnets (PMs) can be good sources for REEs which can help minimize global dependence on freshly mined REEs, but PMs are rarely recycled. Recycling of PMs has been discussed with respect to improving REEs resource sustainability. Some challenges to be addressed in order to establish industrially deployable technologies for PMs recycling have also been discussed, including profitability, energy efficiency and environmental impacts. Key considerations for promoting circular economy via PMs recycling is proposed with the focus on deciding the targetmore » points in the supply chain at which the recycled products will be inserted. Important technical considerations for recycling different forms of waste PMs, including swarfs, slags, shredded and intact hard disk drives magnets, have been presented. Lastly, the aspects of circular economy considered include reusing magnets, remanufacturing magnets and recovering of REEs from waste PMs.« less
Bergmann, Lasse T; Schlicht, Larissa; Meixner, Carmen; König, Peter; Pipa, Gordon; Boshammer, Susanne; Stephan, Achim
2018-01-01
Autonomous vehicles, though having enormous potential, face a number of challenges. As a computer system interacting with society on a large scale and human beings in particular, they will encounter situations, which require moral assessment. What will count as right behavior in such situations depends on which factors are considered to be both morally justified and socially acceptable. In an empirical study we investigated what factors people recognize as relevant in driving situations. The study put subjects in several "dilemma" situations, which were designed to isolate different and potentially relevant factors. Subjects showed a surprisingly high willingness to sacrifice themselves to save others, took the age of potential victims in a crash into consideration and were willing to swerve onto a sidewalk if this saved more lives. The empirical insights are intended to provide a starting point for a discussion, ultimately yielding societal agreement whereby the empirical insights should be balanced with philosophical considerations.
Use of Portal Monitors for Detection of Technogenic Radioactive Sources in Scrap Metal
NASA Astrophysics Data System (ADS)
Solovev, D. B.; Merkusheva, A. E.
2017-11-01
The article considers the features of organization of scrap-metal primary radiation control on the specialized enterprises engaging in its deep processing and storage at using by primary technical equipment - radiation portal monitors. The issue of this direction relevance, validity of radiation control implementation with the use of radiation portal monitors, physical and organizational bases of radiation control are considered in detail. The emphasis is put on the considerable increase in the number of technogenic radioactive sources detected in scrap-metal that results in the entering into exploitation of radioactive metallic structures as different building wares. One of reasons of such increase of the number of technogenic radioactive sources getting for processing with scrap-metal is the absence of any recommendations on the radiation portal monitors exploitation. The practical division of the article offers to recommendation on tuning of the modes of work of radiation portal monitors depending on influence the weather factor thus allowing to considerably increase the percent of technogenic radioactive sources detection.
A Case for Revisiting the Safety of Pesticides: A Closer Look at Neurodevelopment
Colborn, Theo
2006-01-01
The quality and quantity of the data about the risk posed to humans by individual pesticides vary considerably. Unlike obvious birth defects, most developmental effects cannot be seen at birth or even later in life. Instead, brain and nervous system disturbances are expressed in terms of how an individual behaves and functions, which can vary considerably from birth through adulthood. In this article I challenge the protective value of current pesticide risk assessment strategies in light of the vast numbers of pesticides on the market and the vast number of possible target tissues and end points that often differ depending upon timing of exposure. Using the insecticide chlorpyrifos as a model, I reinforce the need for a new approach to determine the safety of all pesticide classes. Because of the uncertainty that will continue to exist about the safety of pesticides, it is apparent that a new regulatory approach to protect human health is needed. PMID:16393651
Addressing Criticality in Rare Earth Elements via Permanent Magnets Recycling
Nlebedim, I. C.; King, A. H.
2017-12-12
Rare earth elements (REEs) are critical for many advanced technologies and are faced with potential supply disruptions. Recycling of permanent magnets (PMs) can be good sources for REEs which can help minimize global dependence on freshly mined REEs, but PMs are rarely recycled. Recycling of PMs has been discussed with respect to improving REEs resource sustainability. Some challenges to be addressed in order to establish industrially deployable technologies for PMs recycling have also been discussed, including profitability, energy efficiency and environmental impacts. Key considerations for promoting circular economy via PMs recycling is proposed with the focus on deciding the targetmore » points in the supply chain at which the recycled products will be inserted. Important technical considerations for recycling different forms of waste PMs, including swarfs, slags, shredded and intact hard disk drives magnets, have been presented. Lastly, the aspects of circular economy considered include reusing magnets, remanufacturing magnets and recovering of REEs from waste PMs.« less
Neural Correlates of Affective Influence on Choice
ERIC Educational Resources Information Center
Piech, Richard M.; Lewis, Jade; Parkinson, Caroline H.; Owen, Adrian M.; Roberts, Angela C.; Downing, Paul E.; Parkinson, John A.
2010-01-01
Making the right choice depends crucially on the accurate valuation of the available options in the light of current needs and goals of an individual. Thus, the valuation of identical options can vary considerably with motivational context. The present study investigated the neural structures underlying context dependent evaluation. We instructed…
Normalization of energy-dependent gamma survey data.
Whicker, Randy; Chambers, Douglas
2015-05-01
Instruments and methods for normalization of energy-dependent gamma radiation survey data to a less energy-dependent basis of measurement are evaluated based on relevant field data collected at 15 different sites across the western United States along with a site in Mongolia. Normalization performance is assessed relative to measurements with a high-pressure ionization chamber (HPIC) due to its "flat" energy response and accurate measurement of the true exposure rate from both cosmic and terrestrial radiation. While analytically ideal for normalization applications, cost and practicality disadvantages have increased demand for alternatives to the HPIC. Regression analysis on paired measurements between energy-dependent sodium iodide (NaI) scintillation detectors (5-cm by 5-cm crystal dimensions) and the HPIC revealed highly consistent relationships among sites not previously impacted by radiological contamination (natural sites). A resulting generalized data normalization factor based on the average sensitivity of NaI detectors to naturally occurring terrestrial radiation (0.56 nGy hHPIC per nGy hNaI), combined with the calculated site-specific estimate of cosmic radiation, produced reasonably accurate predictions of HPIC readings at natural sites. Normalization against two to potential alternative instruments (a tissue-equivalent plastic scintillator and energy-compensated NaI detector) did not perform better than the sensitivity adjustment approach at natural sites. Each approach produced unreliable estimates of HPIC readings at radiologically impacted sites, though normalization against the plastic scintillator or energy-compensated NaI detector can address incompatibilities between different energy-dependent instruments with respect to estimation of soil radionuclide levels. The appropriate data normalization method depends on the nature of the site, expected duration of the project, survey objectives, and considerations of cost and practicality.
Coevolution of patch-type dependent emigration and patch-type dependent immigration.
Weigang, Helene C
2017-08-07
The three phases of dispersal - emigration, transfer and immigration - are affecting each other and the former and latter decisions may depend on patch types. Despite the inevitable fact of the complexity of the dispersal process, patch-type dependencies of dispersal decisions modelled as emigration and immigration are usually missing in theoretical dispersal models. Here, I investigate the coevolution of patch-type dependent emigration and patch-type dependent immigration in an extended Hamilton-May model. The dispersing population inhabits a landscape structured into many patches of two types and disperses during a continuous-time season. The trait under consideration is a four dimensional vector consisting of two values for emigration probability from the patches and two values for immigration probability into the patches of each type. Using the adaptive dynamics approach I show that four qualitatively different dispersal strategies may evolve in different parameter regions, including a counterintuitive strategy, where patches of one type are fully dispersed from (emigration probability is one) but individuals nevertheless always immigrate into them during the dispersal season (immigration probability is one). I present examples of evolutionary branching in a wide parameter range, when the patches with high local death rate during the dispersal season guarantee a high expected disperser output. I find that two dispersal strategies can coexist after evolutionary branching: a strategy with full immigration only into the patches with high expected disperser output coexists with a strategy that immigrates into any patch. Stochastic simulations agree with the numerical predictions. Since evolutionary branching is also found when immigration evolves alone, the present study is adding coevolutionary constraints on the emigration traits and hence finds that the coevolution of a higher dimensional trait sometimes hinders evolutionary diversification. Copyright © 2017 Elsevier Ltd. All rights reserved.
Electronic transport properties of single-crystal bismuth nanowire arrays
NASA Astrophysics Data System (ADS)
Zhang, Zhibo; Sun, Xiangzhong; Dresselhaus, M. S.; Ying, Jackie Y.; Heremans, J.
2000-02-01
We present here a detailed study of the electrical transport properties of single-crystal bismuth nanowire arrays embedded in a dielectric matrix. Measurements of the resistance of Bi nanowire arrays with different wire diameters (60-110 nm) have been carried out over a wide range of temperatures (2.0-300 K) and magnetic fields (0-5.4 T). The transport properties of a heavily Te-doped Bi nanowire array have also been studied. At low temperatures, we show that the wire boundary scattering is the dominant scattering process for carriers in the undoped single-crystal Bi nanowires, while boundary scattering is less important for a heavily Te-doped sample, consistent with general theoretical considerations. The temperature dependences of the zero-field resistivity and of the longitudinal magneto-coefficient of the Bi nanowires were also studied and were found to be sensitive to the wire diameter. The quantum confinement of carriers is believed to play an important role in determining the overall temperature dependence of the zero-field resistivity. Theoretical considerations of the quantum confinement effects on the electronic band structure and on the transport properties of Bi nanowires are discussed. Despite the evidence for localization effects and diffusive electron interactions at low temperatures (T<=4.0 K), localization effects are not the dominant mechanisms affecting the resistivity or the magnetoresistance in the temperature range of this study.
Sex differences in impulsive action and impulsive choice.
Weafer, Jessica; de Wit, Harriet
2014-11-01
Here, we review the evidence for sex differences in behavioral measures of impulsivity for both humans and laboratory animals. We focus on two specific components of impulsivity: impulsive action (i.e., difficulty inhibiting a prepotent response) and impulsive choice (i.e., difficulty delaying gratification). Sex differences appear to exist on these measures, but the direction and magnitude of the differences vary. In laboratory animals, impulsive action is typically greater in males than females, whereas impulsive choice is typically greater in females. In humans, women discount more steeply than men, but sex differences on measures of impulsive action depend on tasks and subject samples. We discuss implications of these findings as they relate to drug addiction. We also point out the major gaps in this research to date, including the lack of studies designed specifically to examine sex differences in behavioral impulsivity, and the lack of consideration of menstrual or estrous phase or sex hormone levels in the studies. © 2013.
Sex differences in impulsive action and impulsive choice
Weafer, Jessica; de Wit, Harriet
2013-01-01
Here, we review the evidence for sex differences in behavioral measures of impulsivity for both humans and laboratory animals. We focus on two specific components of impulsivity: impulsive action (i.e., difficulty inhibiting a prepotent response) and impulsive choice (i.e., difficulty delaying gratification). Sex differences appear to exist on these measures, but the direction and magnitude of the differences vary. In laboratory animals, impulsive action is typically greater in males than females, whereas impulsive choice is typically greater in females. In humans, women discount more steeply than men, but sex differences on measures of impulsive action depend on tasks and subject samples. We discuss implications of these findings as they relate to drug addiction. We also point out the major gaps in this research to date, including the lack of studies designed specifically to examine sex differences in behavioral impulsivity, and the lack of consideration of menstrual or estrous phase or sex hormone levels in the studies. PMID:24286704
NASA Astrophysics Data System (ADS)
Carrera; Valvano; Kulikov
2018-01-01
In this work, a new class of finite elements for the analysis of composite and sandwich shells embedding piezoelectric skins and patches is proposed. The main idea of models coupling is developed by presenting the concept of nodal dependent kinematics where the same finite element can present at each node a different approximation of the main unknowns by setting a node-wise through-the-thickness approximation base. In a global/local approach scenario, the computational costs can be reduced drastically by assuming refined theories only in those zones/nodes of the structural domain where the resulting strain and stress states, and their electro-mechanical coupling present a complex distribution. Several numerical investigations are carried out to validate the accuracy and efficiency of the present shell element. An accurate representation of mechanical stresses and electric displacements in localized zones is possible with reduction of the computational costs if an accurate distribution of the higher-order kinematic capabilities is performed. On the contrary, the accuracy of the solution in terms of mechanical displacements and electric potential values depends on the global approximation over the whole structure. The efficacy of the present node-dependent variable kinematic models, thus, depends on the characteristics of the problem under consideration as well as on the required analysis type.
NASA Technical Reports Server (NTRS)
Chang, Sin-Chung; Wang, Xiao-Yen; Chow, Chuen-Yen
1994-01-01
A new numerical discretization method for solving conservation laws is being developed. This new approach differs substantially in both concept and methodology from the well-established methods, i.e., finite difference, finite volume, finite element, and spectral methods. It is motivated by several important physical/numerical considerations and designed to avoid several key limitations of the above traditional methods. As a result of the above considerations, a set of key principles for the design of numerical schemes was put forth in a previous report. These principles were used to construct several numerical schemes that model a 1-D time-dependent convection-diffusion equation. These schemes were then extended to solve the time-dependent Euler and Navier-Stokes equations of a perfect gas. It was shown that the above schemes compared favorably with the traditional schemes in simplicity, generality, and accuracy. In this report, the 2-D versions of the above schemes, except the Navier-Stokes solver, are constructed using the same set of design principles. Their constructions are simplified greatly by the use of a nontraditional space-time mesh. Its use results in the simplest stencil possible, i.e., a tetrahedron in a 3-D space-time with a vertex at the upper time level and other three at the lower time level. Because of the similarity in their design, each of the present 2-D solvers virtually shares with its 1-D counterpart the same fundamental characteristics. Moreover, it is shown that the present Euler solver is capable of generating highly accurate solutions for a famous 2-D shock reflection problem. Specifically, both the incident and the reflected shocks can be resolved by a single data point without the presence of numerical oscillations near the discontinuity.
Ecomorphology and phylogenetic risk: Implications for habitat reconstruction using fossil bovids.
Scott, Robert S; Barr, W Andrew
2014-08-01
Reconstructions of paleohabitats are necessary aids in understanding hominin evolution. The morphology of species from relevant sites, understood in terms of functional relationships to habitat (termed ecomorphology), offers a direct link to habitat. Bovids are a speciose radiation that includes many habitat specialists and are abundant in the fossil record. Thus, bovids are extremely common in ecomorphological analyses. However, bovid phylogeny and habitat preference are related, which raises the possibility that analyses linking habitat with morphology are not 'taxon free' but 'taxon-dependent.' Here we analyze eight relative dimensions and one shape index of the metatarsal for a sample of 72 bovid species and one antilocaprid. The selected variables have been previously shown to have strong associations with habitat and to have functional explanations for these associations. Phylogenetic generalized least squares analyses of these variables, including habitat and size, resulted in estimates for the parameter lambda (used to model phylogenetic signal) varying from zero to one. Thus, while phylogeny, morphology, and habitat all march together among the bovids, the odds that phylogeny confounds ecomorphological analyses may vary depending on particular morphological characteristics. While large values of lambda do not necessarily indicate that habitat differences are unimportant drivers of morphology, we consider the low value of lambda for relative metatarsal width suggestive that conclusions about habitat built on observations of this particular morphology carry with them less 'phylogenetic risk.' We suggest that the way forward for ecomorphology is grounded in functionally relevant observations and careful consideration of phylogeny designed to bracket probable habitat preferences appropriately. Separate consideration of different morphological variables may help to determine the level of 'phylogenetic risk' attached to conclusions linking habitat and morphology. Copyright © 2014 Elsevier Ltd. All rights reserved.
An efficient method for quantum transport simulations in the time domain
NASA Astrophysics Data System (ADS)
Wang, Y.; Yam, C.-Y.; Frauenheim, Th.; Chen, G. H.; Niehaus, T. A.
2011-11-01
An approximate method based on adiabatic time dependent density functional theory (TDDFT) is presented, that allows for the description of the electron dynamics in nanoscale junctions under arbitrary time dependent external potentials. The density matrix of the device region is propagated according to the Liouville-von Neumann equation. The semi-infinite leads give rise to dissipative terms in the equation of motion which are calculated from first principles in the wide band limit. In contrast to earlier ab initio implementations of this formalism, the Hamiltonian is here approximated in the spirit of the density functional based tight-binding (DFTB) method. Results are presented for two prototypical molecular devices and compared to full TDDFT calculations. The temporal profile of the current traces is qualitatively well captured by the DFTB scheme. Steady state currents show considerable variations, both in comparison of approximate and full TDDFT, but also among TDDFT calculations with different basis sets.
Tensile properties of helical auxetic structures: A numerical study
NASA Astrophysics Data System (ADS)
Wright, J. R.; Sloan, M. R.; Evans, K. E.
2010-08-01
This paper discusses a helical auxetic structure which has a diverse range of practical applications. The mechanical properties of the system can be determined by particular combinations of geometry and component material properties; finite element analysis is used to investigate the static behavior of these structures under tension. Modeling criteria are determined and design issues are discussed. A description of the different strain-dependent mechanical phases is provided. It is shown that the stiffnesses of the component fibers and the initial helical wrap angle are critical design parameters, and that strain-dependent changes in cross-section must be taken into consideration: we observe that the structures exhibit nonlinear behavior due to nonzero component Poisson's ratios. Negative Poisson's ratios for the helical structures as low as -5 are shown. While we focus here on the structure as a yarn our findings are, in principle, scaleable.
Fermi level dependence of hydrogen diffusivity in GaN
NASA Astrophysics Data System (ADS)
Polyakov, A. Y.; Smirnov, N. B.; Pearton, S. J.; Ren, F.; Theys, B.; Jomard, F.; Teukam, Z.; Dmitriev, V. A.; Nikolaev, A. E.; Usikov, A. S.; Nikitina, I. P.
2001-09-01
Hydrogen diffusion studies were performed in GaN samples with different Fermi level positions. It is shown that, at 350 °C, hydrogen diffusion is quite fast in heavily Mg doped p-type material with the Fermi level close to Ev+0.15 eV, considerably slower in high-resistivity p-GaN(Zn) with the Fermi level Ev+0.9 eV, while for conducting and semi-insulating n-GaN samples with the Fermi level in the upper half of the band gap no measurable hydrogen diffusion could be detected. For these latter samples it is shown that higher diffusion temperature of 500 °C and longer times (50 h) are necessary to incorporate hydrogen to appreciable depth. These findings are in line with previously published theoretical predictions of the dependence of hydrogen interstitials formation in GaN on the Fermi level position.
NASA Astrophysics Data System (ADS)
di Ventra, Massimiliano; Peotta, Sebastiano
2014-03-01
In his original work Josephson [Phys. Lett. 1, 251 (1962)] predicted that a phase-dependent conductance should be present in superconductor tunnel junctions. This effect attracted considerable attention in the past but is difficult to detect, mainly because it is hard to single it out from the background pair current. Here, we propose to isolate it by using a two-junction interferometer where the junctions have the same critical currents but different conductances. The pair current is completely suppressed when the magnetic flux in the loop is half of a flux quantum and the device is characterized by a pure phase-dependent conductance. According to the theory of nonlinear circuit elements this is in fact an ideal voltage-controlled memristor. Possible applications of this memristive device are memories and neuromorphic computing within the framework of ultrafast and low-energy superconducting digital circuits. This work has been supported by DOE under Grant No. DE-FG02-05ER46204.
NASA Astrophysics Data System (ADS)
Ren, Guoli; Pei, Wenbing; Lan, Ke; Gu, Peijun; Li, Xin; Institute of Applied Physics; Computional Mathematics Team
2011-10-01
In current routine 2D simulation of hohlraum physics, we adopt the principal-quantum- number(n-level) average atom model(AAM). However, the experimental frequency-dependant radiative drive differs from our n-level simulated drive, which reminds us the need of a more detailed atomic kinetics description. The orbital-quantum-number(nl-level) AAM is a natural consideration but the in-line calculation consumes much more resources. We use a new method to built up a nl-level bound electron distribution using in-line n-level calculated plasma condition (such as temperature, density, average ionization degree). We name this method ``quasi-steady approximation.'' Using the re-built nl-level bound electron distribution (Pnl) , we acquire a new hohlraum radiative drive by post-processing. Comparison with the n-level post-processed hohlraum drive shows that we get an almost identical radiation flux but with more-detailed frequency-dependant structures.
Model systems for life processes on Mars
NASA Technical Reports Server (NTRS)
Mitz, M. A.
1974-01-01
In the evolution of life forms nonphotosynthetic mechanisms are developed. The question remains whether a total life system could evolve which is not dependent upon photosynthesis. In trying to visualize life on other planets, the photosynthetic process has problems. On Mars, the high intensity of light at the surface is a concern and alternative mechanisms need to be defined and analyzed. In the UV search for alternate mechanisms, several different areas may be identified. These involve activated inorganic compounds in the atmosphere, such as the products of photodissociation of carbon dioxide and the organic material which may be created by natural phenomena. In addition, a life system based on the pressure of the atmospheric constituents, such as carbon dioxide, is a possibility. These considerations may be important for the understanding of evolutionary processes of life on another planet. Model systems which depend on these alternative mechanisms are defined and related to presently planned and future planetary missions.
Enhanced electron/fuel-ion equilibration through impurity ions: Studies applicable to NIF and Omega
NASA Astrophysics Data System (ADS)
Petrasso, R. D.; Sio, H.; Kabadi, N.; Lahmann, B.; Simpson, R.; Parker, C.; Frenje, J.; Gatu Johnson, M.; Li, C. K.; Seguin, F. H.; Rinderknecht, H.; Casey, D.; Grabowski, P.; Graziani, F.; Taitano, W.; Le, A.; Chacon, L.; Hoffman, N.; Kagan, G.; Simakov, A.; Zylstra, A.; Rosenberg, M.; Betti, R.; Srinivasan, B.; Mancini, R.
2017-10-01
In shock-driven exploding-pushers, a platform used extensively to study multi-species and kinetic effects, electrons and fuel ions are far out of equilibrium, as reflected by very different temperatures. However, impurity ions, even in small quantities, can couple effectively to the electrons, because of a Z2 dependence, and in turn, impurity ions can then strongly couple to the fuel ions. Through this mechanism, electrons and fuel-ions can equilibrate much faster than they otherwise would. This is a quantitative issue, depending upon the amount and Z of the impurity. For NIF and Omega, we consider the role of this process. Coupled non-linear equations, reflecting the temperatures of the three species, are solved for a range of conditions. Consideration is also given to ablatively driven implosions, since impurities can similarly affect the equilibration. This work was supported in part by DOE/NNSA DE-NA0002949 and DE-NA0002726.
The Effect of Fiber Architecture on Matrix Cracking in Sic/sic Cmc's
NASA Technical Reports Server (NTRS)
Morscher, Gregory N.
2005-01-01
Applications incorporating silicon carbide fiber reinforced silicon carbide matrix composites (CMC's) will require a wide range of fiber architectures in order to fabricate complex shape. The stress-strain response of a given SiC/SiC system for different architectures and orientations will be required in order to design and effectively life-model future components. The mechanism for non-linear stress-strain behavior in CMC's is the formation and propagation of bridged-matrix cracks throughout the composite. A considerable amount of understanding has been achieved for the stress-dependent matrix cracking behavior of SiC fiber reinforced SiC matrix systems containing melt-infiltrated Si. This presentation will outline the effect of 2D and 3D architectures and orientation on stress-dependent matrix-cracking and how this information can be used to model material behavior and serve as the starting point foe mechanistic-based life-models.
Health Insurance and Risk of Divorce: Does Having Your Own Insurance Matter?
Sohn, Heeju
2016-01-01
Most American adults under 65 obtain health insurance through their employers or their spouses’ employers. The absence of a universal healthcare system in the United States puts Americans at considerable risk for losing their coverage when transitioning out of jobs or marriages. Scholars have found evidence of reduced job mobility among individuals who are dependent on their employers for healthcare coverage. This paper finds similar relationships between insurance and divorce. I apply the hazard model to married individuals in the longitudinal Survey of Income Program Participation (N=17,388) and find lower divorce rates among people who are insured through their partners’ plans without alternative sources of their own. Furthermore, I find gender differences in the relationship between healthcare coverage and divorce rates: insurance dependent women have lower rates of divorce than men in similar situations. These findings draw attention to the importance of considering family processes when debating and evaluating health policies. PMID:26949269
Chemotherapy-Induced Amenorrhea – An Update
Liedtke, C.; Kiesel, L.
2012-01-01
Because of the heterogeneity in the definition of chemotherapy-induced amenorrhea (CIA) there are distinct differences in the literature with regard to its incidence as well as its dependence on various influencing factors. The occurrence of CIA varies greatly depending on the applied chemotherapy. The pathogenesis of CIA is especially based on a reduction of ovarian reserves. Various sonographic and biochemical factors can be used to exclude or confirm CIA. This is particularly important when an endocrine therapy with tamoxifen is not possible and the use of aromatase inhibitors is under consideration. CIA and especially the frequently thereby resulting early menopause can lead to pronounced restrictions in the quality of life of the affected patients, not least due to the resulting infertility. On the other hand, various studies have shown that CIA may have a positive prognostic significance. Thus, the identification of measures to prevent CIA (for example, through the use of GnRH analogues) is of particular importance. PMID:26640289
Combustion of Micro- and Nanothermites under Elevating Pressure
NASA Astrophysics Data System (ADS)
Monogarov, K.; Pivkina, Alla; Muravyev, N.; Meerov, D.; Dilhan, D.
Non-equilibrium process of combustion-wave propagation of thermite compositions (Mg/Fe2O3) inside the sealed steel tube have been investigated to study the burning rate at elevating pressure. Under confinement the hot gas-phase products, formed during thermite combustion result in considerable overpressure inside the tube that reverses the gas flow and leads to pressure-driven preheating effect of the burned-gas permeation. Convective origin of this preheating effect is discussed. The pressure-time dependency is obtained experimentally. The composition was pressed inside the steel tube in pellets; the size of each part was measured to obtain burning rate - pressure dependency. Both micro- and nanosized components were used to prepare thermite compositions under study. The significant difference in burning parameters of micron- and nanosized thermites is observed and analyzed. Based on obtained results, the combustion mechanism of thermites with the micro- and nanosized components is discussed.
Reuse of polyethylene waste in road construction.
Raju, S S S V Gopala; Murali, M; Rengaraju, V R
2007-01-01
The cost of construction of flexible pavements depends on thickness of the pavement layers. The thickness of pavement mainly depends on the strength of the subgrade. By suitable improvement to the strength of the subgrade, considerable saving in the scarce resources and economy can be achieved. Because of their lightweight, easy handling, non-breakable and corrosion free nature, polyethylene have surpassed all other materials in utility. But polyethylene waste has been a matter of concern to environmentalists as it is non-biodegradable. In this investigation, an attempt has been made to study the improvement of California Bearing Ratio (CBR) value of soils stabilized with waste polyethylene bags. This alternative material is mixed in different proportions to the gravel and clay to determine the improvement ofCBR value. Use of the waste polyethylene bags observed to have a significant impact on the strength and economy in pavement construction, when these are available locally in large quantities.
Force-endurance capabilities of extravehicular activity (EVA) gloves at different pressure levels
NASA Technical Reports Server (NTRS)
Bishu, Ram R.; Klute, Glenn K.
1993-01-01
The human hand is a very useful multipurpose tool in all environments. However, performance capabilities are compromised considerably when gloves are donned. This is especially true to extravehicular activity (EVA) gloves. The primary intent was to answer the question of how long a person can perform tasks requiring certain levels of exertion. The objective was to develop grip force-endurance relations. Six subjects participated in a factorial experiment involving three hand conditions, three pressure differentials, and four levels of force exertion. The results indicate that, while the force that could be exerted depended on the glove, pressure differential, and the level of exertion, the endurance time at any exertion level depended just on the level of exertion expressed as a percentage of maximum exertion possible at that condition. The impact of these findings for practitioners as well as theoreticians is discussed.
Overtone Mobility Spectrometry (Part 2): Theoretical Considerations of Resolving Power
Valentine, Stephen J.; Stokes, Sarah T.; Kurulugama, Ruwan T.; Nachtigall, Fabiane M.; Clemmer, David E.
2009-01-01
The transport of ions through multiple drift regions is modeled in order to develop an equation that is useful for an understanding of the resolving power of an overtone mobility spectrometry (OMS) technique. It is found that resolving power is influenced by a number of experimental variables, including those that define ion mobility spectrometry (IMS) resolving power: drift field (E), drift region length (L), and buffer gas temperature (T). However, unlike IMS, the resolving power of OMS is also influenced by the number of drift regions (n), harmonic frequency value (m), and the phase number (ϕ) of the applied drift field. The OMS resolving power dependence upon the new OMS variables (n, m, and ϕ) scales differently than the square root dependence of the E, L, and T variables in IMS. The results provide insight about optimal instrumental design and operation. PMID:19230705
NASA Technical Reports Server (NTRS)
Rubesin, M. W.; Rose, W. C.
1973-01-01
The time-dependent, turbulent mean-flow, Reynolds stress, and heat flux equations in mass-averaged dependent variables are presented. These equations are given in conservative form for both generalized orthogonal and axisymmetric coordinates. For the case of small viscosity and thermal conductivity fluctuations, these equations are considerably simpler than the general Reynolds system of dependent variables for a compressible fluid and permit a more direct extension of low speed turbulence modeling to computer codes describing high speed turbulence fields.
Schwartz, Z; Somers, A; Mellonig, J T; Carnes, D L; Dean, D D; Cochran, D L; Boyan, B D
1998-04-01
Demineralized freeze-dried bone allografts (DFDBA) have been used extensively in periodontal therapy. DFDBA is used because it contains bone morphogenetic protein (BMP), which induces new bone formation during the healing process. Most commercial bone banks do not verify the presence or activity of BMP in DFDBA nor the ability of DFDBA to induce new bone. Recently, we showed that different bone bank preparations of DFDBA, even from the same bank, varied considerably in their ability to induce new bone, suggesting inherent differences in the quality of the material. Therefore, we examined whether donor age or gender contributed to the variability seen with these preparations. Twenty-seven batches of DFDBA from different donors were donated by one bone bank which had been shown previously to supply DFDBA that was consistently able to induce new bone formation. Each batch was implanted bilaterally in the thigh muscle of nude mice. After 56 days, the implants were excised and examined by light microscopy and histomorphometry. Seventy percent of the preparations tested induced new bone formation. Most of these preparations produced ossicles containing cortical bone surrounding bone marrow-like tissue. The ability to induce bone appears to be age-dependent, with DFDBA from older donors being less likely to have strong bone-inducing activity. By contrast, no difference in ability to induce new bone was noticed between male or female donors. The results of this study confirm that commercial preparations of DFDBA differ in their ability to induce new bone formation. In fact, some of the batches had no activity at all. The ability of DFDBA to induce new bone formation is suggested to be age-dependent, but not gender-dependent by our study. These results indicate that commercial bone banks need to verify the ability of DFDBA to induce new bone formation and should reconsider the advisability of using bone from older donors.
Szklo, André Salem; Coutinho, Evandro Silva Freire
2010-06-01
Smoking is a worldwide public health problem, and various communication strategies aimed at its cessation have been used. The objective of this paper was to explore differences over time of two communication strategies (gain-framed versus loss-framed) in encouraging calls to a Quitline, according to smoker's degree of dependence. A study was conducted for four weeks among passengers of two selected subway stations in the city of Rio de Janeiro-Brazil (N(average) = 12,500 passengers a day per station). The interventions - large posters with images and text based on central theme "shortness-of-breath" - also contained the Quitline number. Call rate differences between the strategies, overall and specific per study week, were calculated. Light smokers exposed to the positive-content message called on average 2.2 times more often than those exposed to the negative-content message (p < 0.001). The absolute difference in call rates decreased after the first week of the study (p for the additive interaction between intervention and study week, 0.02). For heavy smokers, no differences between the two stations were observed. Additive interaction was found between type of smoker - light or heavy - and intervention (p = 0.02). The results suggest that short-term positive-content campaigns based on issues pertaining to individuals' daily routine could be effective in capturing light smokers. These results may have considerable public health impact, as the prevalence of less dependent smokers is much higher than that of heavier smokers. Copyright 2010 Elsevier Ltd. All rights reserved.
Impact of divalent metal ions on regulation of adenylyl cyclase isoforms by forskolin analogs.
Erdorf, Miriam; Mou, Tung-Chung; Seifert, Roland
2011-12-01
Mammalian membranous adenylyl cyclases (mACs) play an important role in transmembrane signalling events in almost every cell and represent an interesting drug target. Forskolin (FS) is an invaluable research tool, activating AC isoforms 1-8. However, there is a paucity of AC isoform-selective FS analogs. Therefore, we examined the effects of FS and six FS derivatives on recombinant ACs 1, 2 and 5, representing members of different mAC families. Correlations of the pharmacological properties of the different AC isoforms revealed pronounced differences between ACs 1, 2 and 5. Additionally, potencies and efficacies of FS derivatives changed for any given AC isoform, depending on the metal ion, Mg(2+) or Mn(2+). The most striking effects of Mg(2+) and Mn(2+) on the diterpene profile were observed for AC2 where the large inhibitory effect of BODIPY-FS in the presence of Mg(2+) was considerably reduced in the presence of Mn(2+). Sequence alignment and docking experiments confirmed an exceptional position of AC2 compared to ACs 1 and 5 with respect to the structural environment of the catalytic core and cation-dependent diterpene effects. In conclusion, mAC isoforms 1, 2 and 5 exhibit a distinct pharmacological diterpene profile, depending on the divalent cation present. mAC crystal structures and modelling/docking studies provided an explanation for the pharmacological differences between the AC isoforms. Our study constitutes an important step towards the development of isoform-specific diterpenes exhibiting stimulatory or inhibitory effects. Copyright © 2011 Elsevier Inc. All rights reserved.
Cross, Zachariah R.; Kohler, Mark J.; Schlesewsky, Matthias; Gaskell, M. G.; Bornkessel-Schlesewsky, Ina
2018-01-01
We hypothesize a beneficial influence of sleep on the consolidation of the combinatorial mechanisms underlying incremental sentence comprehension. These predictions are grounded in recent work examining the effect of sleep on the consolidation of linguistic information, which demonstrate that sleep-dependent neurophysiological activity consolidates the meaning of novel words and simple grammatical rules. However, the sleep-dependent consolidation of sentence-level combinatorics has not been studied to date. Here, we propose that dissociable aspects of sleep neurophysiology consolidate two different types of combinatory mechanisms in human language: sequence-based (order-sensitive) and dependency-based (order-insensitive) combinatorics. The distinction between the two types of combinatorics is motivated both by cross-linguistic considerations and the neurobiological underpinnings of human language. Unifying this perspective with principles of sleep-dependent memory consolidation, we posit that a function of sleep is to optimize the consolidation of sequence-based knowledge (the when) and the establishment of semantic schemas of unordered items (the what) that underpin cross-linguistic variations in sentence comprehension. This hypothesis builds on the proposal that sleep is involved in the construction of predictive codes, a unified principle of brain function that supports incremental sentence comprehension. Finally, we discuss neurophysiological measures (EEG/MEG) that could be used to test these claims, such as the quantification of neuronal oscillations, which reflect basic mechanisms of information processing in the brain. PMID:29445333
Aircraft-type dependency of contrail evolution
NASA Astrophysics Data System (ADS)
Unterstrasser, S.; Görsch, N.
2014-12-01
The impact of aircraft type on contrail evolution is assessed using a large eddy simulation model with Lagrangian ice microphysics. Six different aircraft ranging from the small regional airliner Bombardier CRJ to the largest aircraft Airbus A380 are taken into account. Differences in wake vortex properties and fuel flow lead to considerable variations in the early contrail geometric depth and ice crystal number. Larger aircraft produce contrails with more ice crystals (assuming that the number of initially generated ice crystals per kilogram fuel is constant). These initial differences are reduced in the first minutes, as the ice crystal loss during the vortex phase is stronger for larger aircraft. In supersaturated air, contrails of large aircraft are much deeper after 5 min than those of small aircraft. A parameterization for the final vertical displacement of the wake vortex system is provided, depending only on the initial vortex circulation and stratification. Cloud resolving simulations are used to examine whether the aircraft-induced initial differences have a long-lasting mark. These simulations suggest that the synoptic scenario controls the contrail cirrus evolution qualitatively. However, quantitative differences between the contrail cirrus properties of the various aircraft remain over the total simulation period of 6 h. The total extinctions of A380-produced contrails are about 1.5 to 2.5 times higher than those from contrails of a Bombardier CRJ.
NASA Astrophysics Data System (ADS)
Kengne, E.; Lakhssassi, A.; Liu, W. M.
2017-08-01
A lossless nonlinear L C transmission network is considered. With the use of the reductive perturbation method in the semidiscrete limit, we show that the dynamics of matter-wave solitons in the network can be modeled by a one-dimensional Gross-Pitaevskii (GP) equation with a time-dependent linear potential in the presence of a chemical potential. An explicit expression for the growth rate of a purely growing modulational instability (MI) is presented and analyzed. We find that the potential parameter of the GP equation of the system does not affect the different regions of the MI. Neglecting the chemical potential in the GP equation, we derive exact analytical solutions which describe the propagation of both bright and dark solitary waves on continuous-wave (cw) backgrounds. Using the found exact analytical solutions of the GP equation, we investigate numerically the transmission of both bright and dark solitary voltage signals in the network. Our numerical studies show that the amplitude of a bright solitary voltage signal and the depth of a dark solitary voltage signal as well as their width, their motion, and their behavior depend on (i) the propagation frequencies, (ii) the potential parameter, and (iii) the amplitude of the cw background. The GP equation derived in this paper with a time-dependent linear potential opens up different ideas that may be of considerable theoretical interest for the management of matter-wave solitons in nonlinear L C transmission networks.
Bressler, David W; Fortenbaugh, Francesca C; Robertson, Lynn C; Silver, Michael A
2013-06-07
Endogenous visual spatial attention improves perception and enhances neural responses to visual stimuli at attended locations. Although many aspects of visual processing differ significantly between central and peripheral vision, little is known regarding the neural substrates of the eccentricity dependence of spatial attention effects. We measured amplitudes of positive and negative fMRI responses to visual stimuli as a function of eccentricity in a large number of topographically-organized cortical areas. Responses to each stimulus were obtained when the stimulus was attended and when spatial attention was directed to a stimulus in the opposite visual hemifield. Attending to the stimulus increased both positive and negative response amplitudes in all cortical areas we studied: V1, V2, V3, hV4, VO1, LO1, LO2, V3A/B, IPS0, TO1, and TO2. However, the eccentricity dependence of these effects differed considerably across cortical areas. In early visual, ventral, and lateral occipital cortex, attentional enhancement of positive responses was greater for central compared to peripheral eccentricities. The opposite pattern was observed in dorsal stream areas IPS0 and putative MT homolog TO1, where attentional enhancement of positive responses was greater in the periphery. Both the magnitude and the eccentricity dependence of attentional modulation of negative fMRI responses closely mirrored that of positive responses across cortical areas. Copyright © 2013 Elsevier Ltd. All rights reserved.
Differential Effects of Carbohydrates on Arabidopsis Pollen Germination.
Hirsche, Jörg; García Fernández, José M; Stabentheiner, Edith; Großkinsky, Dominik K; Roitsch, Thomas
2017-04-01
Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.
Assessment of cardiac fibrosis: a morphometric method comparison for collagen quantification.
Schipke, Julia; Brandenberger, Christina; Rajces, Alexandra; Manninger, Martin; Alogna, Alessio; Post, Heiner; Mühlfeld, Christian
2017-04-01
Fibrotic remodeling of the heart is a frequent condition linked to various diseases and cardiac dysfunction. Collagen quantification is an important objective in cardiac fibrosis research; however, a variety of different histological methods are currently used that may differ in accuracy. Here, frequently applied collagen quantification techniques were compared. A porcine model of early stage heart failure with preserved ejection fraction was used as an example. Semiautomated threshold analyses were imprecise, mainly due to inclusion of noncollagen structures or failure to detect certain collagen deposits. In contrast, collagen assessment by automated image analysis and light microscopy (LM)-stereology was more sensitive. Depending on the quantification method, the amount of estimated collagen varied and influenced intergroup comparisons. PicroSirius Red, Masson's trichrome, and Azan staining protocols yielded similar results, whereas the measured collagen area increased with increasing section thickness. Whereas none of the LM-based methods showed significant differences between the groups, electron microscopy (EM)-stereology revealed a significant collagen increase between cardiomyocytes in the experimental group, but not at other localizations. In conclusion, in contrast to the staining protocol, section thickness and the quantification method being used directly influence the estimated collagen content and thus, possibly, intergroup comparisons. EM in combination with stereology is a precise and sensitive method for collagen quantification if certain prerequisites are considered. For subtle fibrotic alterations, consideration of collagen localization may be necessary. Among LM methods, LM-stereology and automated image analysis are appropriate to quantify fibrotic changes, the latter depending on careful control of algorithm and comparable section staining. NEW & NOTEWORTHY Direct comparison of frequently applied histological fibrosis assessment techniques revealed a distinct relation of measured collagen and utilized quantification method as well as section thickness. Besides electron microscopy-stereology, which was precise and sensitive, light microscopy-stereology and automated image analysis proved to be appropriate for collagen quantification. Moreover, consideration of collagen localization might be important in revealing minor fibrotic changes. Copyright © 2017 the American Physiological Society.
Meredith-Jones, Kim; Williams, Sheila; Galland, Barbara; Kennedy, Gavin; Taylor, Rachael
2016-01-01
Although accelerometers can assess sleep and activity over 24 h, sleep data must be removed before physical activity and sedentary time can be examined appropriately. We compared the effect of 6 different sleep-scoring rules on physical activity and sedentary time. Activity and sleep were obtained by accelerometry (ActiGraph GT3X) over 7 days in 291 children (51.3% overweight or obese) aged 4-8.9 years. Three methods removed sleep using individualised time filters and two methods applied standard time filters to remove sleep each day (9 pm-6 am, 12 am-6 am). The final method did not remove sleep but simply defined non-wear as at least 60 min of consecutive zeros over the 24-h period. Different methods of removing sleep from 24-h data markedly affect estimates of sedentary time, yielding values ranging from 556 to 1145 min/day. Estimates of non-wear time (33-193 min), wear time (736-1337 min) and counts per minute (384-658) also showed considerable variation. By contrast, estimates of moderate-to-vigorous activity (MVPA) were similar, varying by less than 1 min/day. Different scoring methods to remove sleep from 24-h accelerometry data do not affect measures of MVPA, whereas estimates of counts per minute and sedentary time depend considerably on which technique is used.
Magnusson, P; Bäck, S A; Olsson, L E
1999-11-01
MR image nonuniformity can vary significantly with the spin-echo pulse sequence repetition time. When MR images with different nonuniformity shapes are used in a T1-calculation the resulting T1-image becomes nonuniform. As shown in this work the uniformity TR-dependence of the spin-echo pulse sequence is a critical property for T1 measurements in general and for ferrous sulfate dosimeter gel (FeGel) applications in particular. The purpose was to study the characteristics of the MR image plane nonuniformity in FeGel evaluation. This included studies of the possibility of decreasing nonuniformities by selecting uniformity optimized repetition times, studies of the transmitted and received RF-fields and studies of the effectiveness of the correction methods background subtraction and quotient correction. A pronounced MR image nonuniformity variation with repetition and T1 relaxation time was observed, and was found to originate from nonuniform RF-transmission in combination with the inherent differences in T1 relaxation for different repetition times. The T1 calculation itself, the uniformity optimized repetition times, nor none of the correction methods studied could sufficiently correct the nonuniformities observed in the T1 images. The nonuniformities were found to vary considerably less with inversion time for the inversion-recovery pulse sequence, than with repetition time for the spin-echo pulse sequence, resulting in considerably lower T1 image nonuniformity levels.
No rationale for 1 variable per 10 events criterion for binary logistic regression analysis.
van Smeden, Maarten; de Groot, Joris A H; Moons, Karel G M; Collins, Gary S; Altman, Douglas G; Eijkemans, Marinus J C; Reitsma, Johannes B
2016-11-24
Ten events per variable (EPV) is a widely advocated minimal criterion for sample size considerations in logistic regression analysis. Of three previous simulation studies that examined this minimal EPV criterion only one supports the use of a minimum of 10 EPV. In this paper, we examine the reasons for substantial differences between these extensive simulation studies. The current study uses Monte Carlo simulations to evaluate small sample bias, coverage of confidence intervals and mean square error of logit coefficients. Logistic regression models fitted by maximum likelihood and a modified estimation procedure, known as Firth's correction, are compared. The results show that besides EPV, the problems associated with low EPV depend on other factors such as the total sample size. It is also demonstrated that simulation results can be dominated by even a few simulated data sets for which the prediction of the outcome by the covariates is perfect ('separation'). We reveal that different approaches for identifying and handling separation leads to substantially different simulation results. We further show that Firth's correction can be used to improve the accuracy of regression coefficients and alleviate the problems associated with separation. The current evidence supporting EPV rules for binary logistic regression is weak. Given our findings, there is an urgent need for new research to provide guidance for supporting sample size considerations for binary logistic regression analysis.
Gutiérrez-Fonseca, Pablo E; Lorion, Christopher M
2014-04-01
The use of aquatic macroinvertebrates as bio-indicators in water quality studies has increased considerably over the last decade in Costa Rica, and standard biomonitoring methods have now been formulated at the national level. Nevertheless, questions remain about the effectiveness of different methods of sampling freshwater benthic assemblages, and how sampling intensity may influence biomonitoring results. In this study, we compared the results of qualitative sampling using commonly applied methods with a more intensive quantitative approach at 12 sites in small, lowland streams on the southern Caribbean slope of Costa Rica. Qualitative samples were collected following the official protocol using a strainer during a set time period and macroinvertebrates were field-picked. Quantitative sampling involved collecting ten replicate Surber samples and picking out macroinvertebrates in the laboratory with a stereomicroscope. The strainer sampling method consistently yielded fewer individuals and families than quantitative samples. As a result, site scores calculated using the Biological Monitoring Working Party-Costa Rica (BMWP-CR) biotic index often differed greatly depending on the sampling method. Site water quality classifications using the BMWP-CR index differed between the two sampling methods for 11 of the 12 sites in 2005, and for 9 of the 12 sites in 2006. Sampling intensity clearly had a strong influence on BMWP-CR index scores, as well as perceived differences between reference and impacted sites. Achieving reliable and consistent biomonitoring results for lowland Costa Rican streams may demand intensive sampling and requires careful consideration of sampling methods.
Kristensen, Anders S; Larsen, Mads B; Johnsen, Laust B; Wiborg, Ove
2004-03-01
The serotonin transporter (SERT) belongs to a family of sodium-chloride-dependent transporters responsible for uptake of amino acids and biogenic amines from the extracellular space. SERT represents a major pharmacological target in the treatment of several clinical conditions, including depression and anxiety. In the present study we have undertaken a mutational scanning of human SERT in order to identify residues that are responsible for individual differences among related monoamine transporters. One mutant, G100A, was inactive in transport. However, ligand binding affinity was similar to wild-type, suggesting that G100A amongst different possible SERT conformations is restrained to a binding conformation. We suggest that the main role of glycine-100 is to confer structural flexibility during substrate translocation. For the two single mutants, T178A and F263C, uptake rates and K(m) values were both several-fold higher than wild-type while binding affinities and inhibitory potencies decreased considerably for several drugs. Ion dependency increased and only at hyperosmotic concentrations were K(m) values partly restored. For the double mutant, T178A/F263C, shifts in uptake kinetics and ligand affinities, as well as ion dependencies, were drastic. Effects were synergistic compared to the corresponding single mutants. In conclusion, we suggest that mutating threonine-178 to an alanine and phenylalanine-263 to a cysteine mainly alter the overall uptake kinetics of SERT by affecting the conformational equilibrium of different transporter conformations.
Huang, Jr-Chuan; Lee, Tsung-Yu; Teng, Tse-Yang; Chen, Yi-Chin; Huang, Cho-Ying; Lee, Cheing-Tung
2014-01-01
The exponent decay in landslide frequency-area distribution is widely used for assessing the consequences of landslides and with some studies arguing that the slope of the exponent decay is universal and independent of mechanisms and environmental settings. However, the documented exponent slopes are diverse and hence data processing is hypothesized for this inconsistency. An elaborated statistical experiment and two actual landslide inventories were used here to demonstrate the influences of the data processing on the determination of the exponent. Seven categories with different landslide numbers were generated from the predefined inverse-gamma distribution and then analyzed by three data processing procedures (logarithmic binning, LB, normalized logarithmic binning, NLB and cumulative distribution function, CDF). Five different bin widths were also considered while applying LB and NLB. Following that, the maximum likelihood estimation was used to estimate the exponent slopes. The results showed that the exponents estimated by CDF were unbiased while LB and NLB performed poorly. Two binning-based methods led to considerable biases that increased with the increase of landslide number and bin width. The standard deviations of the estimated exponents were dependent not just on the landslide number but also on binning method and bin width. Both extremely few and plentiful landslide numbers reduced the confidence of the estimated exponents, which could be attributed to limited landslide numbers and considerable operational bias, respectively. The diverse documented exponents in literature should therefore be adjusted accordingly. Our study strongly suggests that the considerable bias due to data processing and the data quality should be constrained in order to advance the understanding of landslide processes.
PCDD/F enviromental impact from municipal solid waste bio-drying plant.
Rada, E C; Ragazzi, M; Zardi, D; Laiti, L; Ferrari, A
2011-06-01
The present work indentifies some environmental and health impacts of a municipal solid waste bio-drying plant taking into account the PCDD/F release into the atmosphere, its concentration at ground level and its deposition. Four scenarios are presented for the process air treatment and management: biofilter or regenerative thermal oxidation treatment, at two different heights. A Gaussian dispersion model, AERMOD, was used in order to model the dispersion and deposition of the PCDD/F emissions into the atmosphere. Considerations on health risk, from different exposure pathways are presented using an original approach. The case of biofilter at ground level resulted the most critical, depending on the low dispersion of the pollutants. Suggestions on technical solutions for the optimization of the impact are presented. Copyright © 2011 Elsevier Ltd. All rights reserved.
Pharmacological Findings on the Biochemical Bases of Memory Processes: A General View
Izquierdo, Iván; Cammarota, Martín; Medina, Jorge H.; Bevilaqua, Lia R. M.
2004-01-01
We have advanced considerably in the past 2 to 3 years in understanding the molecular mechanisms of consolidation, retrieval, and extinction of memories, particularly of fear memory. This advance was mainly due to pharmacological studies in many laboratories using localized brain injections of molecularly specific substances. One area in which significant advances have been made is in understanding that many different brain structures are involved in different memories, and that often several brain regions are involved in processing the same memory. These regions can cooperate or compete with each other, depending on circumstances that are beginning to be identified quite clearly. Another aspect in which major advances were made was retrieval and post-retrieval events, especially extinction, pointing to new therapeutic approaches to fearmotivated mental disorders. PMID:15656267
New approach to effective diffusion coefficient evaluation in the nanostructured two-phase media
NASA Astrophysics Data System (ADS)
Lyashenko, Yu. O.; Liashenko, O. Y.; Morozovich, V. V.
2018-03-01
Most widely used basic and combined models for evaluation of the effective diffusion parameters of inhomogeneous two-phase zone are reviewed. A new combined model of effective medium is analyzed for the description of diffusion processes in the two-phase zones. In this model the effective diffusivity depends on the growth kinetic coefficients of each phase, the volume fractions of phases and on the additional parameter that generally characterizes the structure type of the two-phase zone. Our combined model describes two-phase zone evolution in the binary systems based on consideration of the diffusion fluxes through both phases. The Lattice Monte Carlo method was used to test the validity of different phenomenological models for evaluation of the effective diffusivity in nanostructured two-phase zones with different structural morphology.
Glass transition behavior of polystyrene/silica nanocomposites.
NASA Astrophysics Data System (ADS)
Xie, Yuping; Sen, Sudeepto; Kumar, Sanat; Bansal, Amitabh
2006-03-01
The change in thermomechanical properties of nano-filled polymers is of considerable scientific and technological interest. The interaction between the nanofillers and the matrix polymer controls the nanocomposite properties. We will present the results from recent and ongoing DSC experiments on polystyrene/silica nanocomposites. Polystyrene of different molecular weights (and from different sources) and silica nanoparticles 10-15 nm in diameter (both as received from Nissan and surface modified by grafted or physisorbed polystyrene) are being used to process the nanocomposites. We are studying trends in the glass transition behavior by changing the matrix molecular weights and the silica weight fractions. Recent data indicate that the glass transition temperature can both decrease and increase depending on the polymer-nanofiller combination as well as the thermal treatment of the nanocomposites prior to the DSC runs.
Characteristics of organic acids in the fruit of different pumpkin species.
Nawirska-Olszańska, Agnieszka; Biesiada, Anita; Sokół-Łętowska, Anna; Kucharska, Alicja Z
2014-04-01
The aim of the research was to determine the composition of organic acids in fruit of different cultivars of three pumpkin species. The amount of acids immediately after fruit harvest and after 3 months of storage was compared. The content of organic acids in the examined pumpkin cultivars was assayed using the method of high performance liquid chromatography (HPLC). Three organic acids (citric acid, malic acid, and fumaric acid) were identified in the cultivars, whose content considerably varied depending on a cultivar. Three-month storage resulted in decreased content of the acids in the case of cultivars belonging to Cucurbita maxima and Cucurbita pepo species, while a slight increase was recorded for Cucurbita moschata species. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
Partially Premixed Flame (PPF) Research for Fire Safety
NASA Technical Reports Server (NTRS)
Puri, Ishwar K.; Aggarwal, Suresh K.; Lock, Andrew J.; Hegde, Uday
2004-01-01
Incipient fires typically occur after the partial premixing of fuel and oxidizer. The mixing of product species into the fuel/oxidizer mixture influences flame stabilization and fire spread. Therefore, it is important to characterize the impact of different levels of fuel/oxidizer/product mixing on flame stabilization, liftoff and extinguishment under different gravity conditions. With regard to fire protection, the agent concentration required to achieve flame suppression is an important consideration. The initial stage of an unwanted fire in a microgravity environment will depend on the level of partial premixing and the local conditions such as air currents generated by the fire itself and any forced ventilation (that influence agent and product mixing into the fire). The motivation of our investigation is to characterize these impacts in a systematic and fundamental manner.
Hartman, Sarah; Belsky, Jay
2016-12-01
An evolutionary perspective of human development provides the basis for the differential-susceptibility hypothesis which stipulates that individuals should differ in their susceptibility to environmental influences, with some being more affected than others by both positive and negative developmental experiences and environmental exposures. This paper reviews evidence consistent with this claim while revealing that temperamental and genetic characteristics play a role in distinguishing more and less susceptible individuals. The differential-susceptibility framework under consideration is contrasted to the traditional diathesis-stress view that "vulnerability" traits predispose some to being disproportionately affected by (only) adverse experiences. We raise several issues stimulated by the literature that need to be clarified in further research. Lastly, we suggest that therapy may differ in its effects depending on an individual's susceptibility. © 2015 Family Process Institute.
NASA Astrophysics Data System (ADS)
Dotto, Guilherme Luiz; Meili, Lucas; Tanabe, Eduardo Hiromitsu; Chielle, Daniel Padoin; Moreira, Marcos Flávio Pinto
2018-02-01
The mass transfer process that occurs in the thin layer drying of papaya seeds was studied under different conditions. The external mass transfer resistance and the dependence of effective diffusivity ( D EFF ) in relation to the moisture ratio ( \\overline{MR} ) and temperature ( T) were investigated from the perspective of diffusive models. It was verified that the effective diffusivity was affected by the moisture content and temperature. A new correlation was proposed for drying of papaya seeds in order to describe these influences. Regarding the use of diffusive models, the results showed that, at conditions of low drying rates ( T ≤ 70 °C), the external mass transfer resistance, as well as the dependence of the effective diffusivity with respect to the temperature and moisture content should be considered. At high drying rates ( T > 90 °C), the dependence of the effective diffusivity with respect to the temperature and moisture content can be neglected, but the external mass transfer resistance was still considerable in the range of air velocities used in this work.
Estimation of value at risk in currency exchange rate portfolio using asymmetric GJR-GARCH Copula
NASA Astrophysics Data System (ADS)
Nurrahmat, Mohamad Husein; Noviyanti, Lienda; Bachrudin, Achmad
2017-03-01
In this study, we discuss the problem in measuring the risk in a portfolio based on value at risk (VaR) using asymmetric GJR-GARCH Copula. The approach based on the consideration that the assumption of normality over time for the return can not be fulfilled, and there is non-linear correlation for dependent model structure among the variables that lead to the estimated VaR be inaccurate. Moreover, the leverage effect also causes the asymmetric effect of dynamic variance and shows the weakness of the GARCH models due to its symmetrical effect on conditional variance. Asymmetric GJR-GARCH models are used to filter the margins while the Copulas are used to link them together into a multivariate distribution. Then, we use copulas to construct flexible multivariate distributions with different marginal and dependence structure, which is led to portfolio joint distribution does not depend on the assumptions of normality and linear correlation. VaR obtained by the analysis with confidence level 95% is 0.005586. This VaR derived from the best Copula model, t-student Copula with marginal distribution of t distribution.
NASA Astrophysics Data System (ADS)
European Muon Collaboration; Arneodo, M.; Arvidson, A.; Aubert, J. J.; Badelek, B.; Beaufays, J.; Bee, C. P.; Benchouk, C.; Berghoff, G.; Bird, I. G.; Blum, D.; Böhm, E.; de Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S. C.; Brück, H.; Calén, H.; Chima, J. S.; Ciborowski, J.; Clifft, R.; Coignet, G.; Combley, F.; Coughlan, J.; d'Agostini, G.; Dahlgren, S.; Derado, I.; Dreyer, T.; Drees, J.; Düren, M.; Eckardt, V.; Edwards, A.; Edwards, M.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Gabathuler, E.; Gajewski, J.; Gamet, R.; Geddes, N.; Grafström, P.; Gustafsson, L.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Jaffre, M.; Jacholkowska, A.; Janata, F.; Jancso, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Krüger, A.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Malecki, P.; Manz, A.; Maselli, S.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Pawlik, B.; Payre, P.; Peroni, C.; Peschel, H.; Pessard, H.; Pettingale, J.; Pietrzyk, B.; Poensgen, B.; Pötsch, M.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Sandacz, A.; Scheer, M.; Schlagböhmer, A.; Schiemann, H.; Schmitz, N.; Schneegans, M.; Scholz, M.; Schouten, M.; Schröder, T.; Schultze, K.; Sloan, T.; Stier, H. E.; Studt, M.; Taylor, G. N.; Thenard, J. M.; Thompson, J. C.; de la Torre, A.; Toth, J.; Urban, L.; Urban, L.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S. J.; Windmolders, R.; Wolf, G.
1990-03-01
Small angle scattering of 280 GeV positive muons by deuterium, carbon and calcium has been measured at scattering angles down to 2 mrad. The nucleon structure function F2 extracted from deuterium does not show a significant x dependence in the measured range of Q2 and its Q2 dependence is linear in logQ2. For calcium, a depletion of F2 is observed at low x by 30% as compared with the values at x = 0.1 where F2(Ca) and F2 (D) are not significantly different. This depletion is attributed to shadowing. The carbon structure function exhibits a similar, but less pronounced, x dependence. Such behaviour is observed to be independent of Q2. The data are consistent with those obtained from other charged lepton experiments both at similar and higher values of x and Q2 and considerably extend the range of the measurements down to the low values of x to be measured in forthcoming experiments at HERA.
Fundamental differences between wildlife and biomedical research.
Sikes, Robert S; Paul, Ellen
2013-01-01
Non-human animals have starred in countless productions of biological research. Whether they play the lead or supporting role depends on the nature of the investigation. These differences in the roles of animals affect nearly every facet of animal involvement, including: the choice of species, the sample size, the source of individuals, and the settings in which the animals are used. These roles establish different baselines for animal use that require substantially different ethical considerations. Efficient and appropriate oversight of wildlife research benefits the animals and their investigators. Toward that end, Institutional Animal Care and Use Committee (IACUCs) must appreciate the profound differences between biomedical and wildlife research and recognize the value of the state and federal permitting processes required for wildlife studies. These processes assure us that potential impacts beyond the level of the individual are minimal or are justified. Most importantly, IACUCs must recognize that they, and their investigators, have an obligation to use appropriate guidelines for evaluating wildlife research.
Gender and creativity: an overview of psychological and neuroscientific literature.
Abraham, Anna
2016-06-01
The topic of gender differences in creativity is one that generates substantial scientific and public interest, but also courts considerable controversy. Owing to the heterogeneous nature of the findings associated with this line of research, the general picture often appears puzzling or obscure. This article presents a selective overview of psychological and neuroscientific literature that has a relevant bearing on the theme of gender and creativity. Topics that are explored include the definition and methods of assessing creativity, a summary of behavioral investigations on gender in relation to creativity, postulations that have been put forward to understand gender differences in creative achievement, gender-based differences in the structure and function of the brain, gender-related differences in behavioral performance on tasks of normative cognition, and neuroscientific studies of gender and creativity. The article ends with a detailed discussion of the idea that differences between men and women in creative cognition are best explained with reference to the gender-dependent adopted strategies or cognitive style when faced with generative tasks.
Ikehata, Hironobu
2018-05-31
Ultraviolet radiation (UVR) predominantly induces UV-signature mutations, C → T and CC → TT base substitutions at dipyrimidine sites, in the cellular and skin genome. I observed in our in vivo mutation studies of mouse skin that these UVR-specific mutations show a wavelength-dependent variation in their sequence-context preference. The C → T mutation occurs most frequently in the 5'-TCG-3' sequence regardless of the UVR wavelength, but is recovered more preferentially there as the wavelength increases, resulting in prominent occurrences exclusively in the TCG sequence in the UVA wavelength range, which I will designate as a "UVA signature" in this review. The preference of the UVB-induced C → T mutation for the sequence contexts shows a mixed pattern of UVC- and UVA-induced mutations, and a similar pattern is also observed for natural sunlight, in which UVB is the most genotoxic component. In addition, the CC → TT mutation hardly occurs at UVA1 wavelengths, although it is detected rarely but constantly in the UVC and UVB ranges. This wavelength-dependent variation in the sequence-context preference of the UVR-specific mutations could be explained by two different photochemical mechanisms of cyclobutane pyrimidine dimer (CPD) formation. The UV-signature mutations observed in the UVC and UVB ranges are known to be caused mainly by CPDs produced through the conventional singlet/triplet excitation of pyrimidine bases after the direct absorption of the UVC/UVB photon energy in those bases. On the other hand, a novel photochemical mechanism through the direct absorption of the UVR energy to double-stranded DNA, which is called "collective excitation", has been proposed for the UVA-induced CPD formation. The UVA photons directly absorbed by DNA produce CPDs with a sequence context preference different from that observed for CPDs caused by the UVC/UVB-mediated singlet/triplet excitation, causing CPD formation preferentially at thymine-containing dipyrimidine sites and probably also preferably at methyl CpG-associated dipyrimidine sites, which include the TCG sequence. In this review, I present a mechanistic consideration on the wavelength-dependent variation of the sequence context preference of the UVR-specific mutations and rationalize the proposition of the UVA-signature mutation, in addition to the UV-signature mutation.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Preston, Benjamin L.; King, Anthony W.; Ernst, Kathleen M.
Human agency is an essential determinant of the dynamics of agroecosystems. However, the manner in which agency is represented within different approaches to agroecosystem modeling is largely contingent on the scales of analysis and the conceptualization of the system of interest. While appropriate at times, narrow conceptualizations of agroecosystems can preclude consideration for how agency manifests at different scales, thereby marginalizing processes, feedbacks, and constraints that would otherwise affect model results. Modifications to the existing modeling toolkit may therefore enable more holistic representations of human agency. Model integration can assist with the development of multi-scale agroecosystem modeling frameworks that capturemore » different aspects of agency. In addition, expanding the use of socioeconomic scenarios and stakeholder participation can assist in explicitly defining context-dependent elements of scale and agency. Finally, such approaches, however, should be accompanied by greater recognition of the meta agency of model users and the need for more critical evaluation of model selection and application.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rusek, Marian; Orlowski, Arkadiusz
2005-04-01
The dynamics of small ({<=}55 atoms) argon clusters ionized by an intense femtosecond laser pulse is studied using a time-dependent Thomas-Fermi model. The resulting Bloch-like hydrodynamic equations are solved numerically using the smooth particle hydrodynamics method without the necessity of grid simulations. As follows from recent experiments, absorption of radiation and subsequent ionization of clusters observed in the short-wavelength laser frequency regime (98 nm) differs considerably from that in the optical spectral range (800 nm). Our theoretical approach provides a unified framework for treating these very different frequency regimes and allows for a deeper understanding of the underlying cluster explosionmore » mechanisms. The results of our analysis following from extensive numerical simulations presented in this paper are compared both with experimental findings and with predictions of other theoretical models.« less
Octopuses (Enteroctopus dofleini) recognize individual humans.
Anderson, Roland C; Mather, Jennifer A; Monette, Mathieu Q; Zimsen, Stephanie R M
2010-01-01
This study exposed 8 Enteroctopus dofleini separately to 2 unfamiliar individual humans over a 2-week period under differing circumstances. One person consistently fed the octopuses and the other touched them with a bristly stick. Each human recorded octopus body patterns, behaviors, and respiration rates directly after each treatment. At the end of 2 weeks, a body pattern (a dark Eyebar) and 2 behaviors (reaching arms toward or away from the tester and funnel direction) were significantly different in response to the 2 humans. The respiration rate of the 4 larger octopuses changed significantly in response to the 2 treatments; however, there was no significant difference in the 4 smaller octopuses' respiration. Octopuses' ability to recognize humans enlarges our knowledge of the perceptual ability of this nonhuman animal, which depends heavily on learning in response to visual information. Any training paradigm should take such individual recognition into consideration as it could significantly alter the octopuses' responses.
Space station related investigations in Europe
NASA Astrophysics Data System (ADS)
Wienss, W.; Vallerain, E.
1984-10-01
Studies pertaining to the definition of Europe's role in the Space Station program are described, with consideration given to such elements as pressurized modules as laboratories for materials processing and life sciences, unpressurized elements, and service vehicles for on-orbit maintenance and repair activities. Candidate elements were selected against such criteria as clean interfaces, the satisfaction of European user needs, new technology items, and European financial capabilities; and their technical and programmatic implications were examined. Different scenarios were considered, ranging from a fully Space-Station-dependent case to a completely autonomous, free-flying man-tendable configuration. Recommendations on a collaboration between Europe and the United States are presented.
An overview of strength training injuries: acute and chronic.
Lavallee, Mark E; Balam, Tucker
2010-01-01
This article introduces the history of strength training, explains the many different styles of strength training, and discusses common injuries specific to each style. Strength training is broken down into five disciplines: basic strength or resistance training, bodybuilding, power lifting, style-dependant strength sports (e.g., strongman competitions, Highland games, field events such as shot put, discus, hammer throw, and javelin), and Olympic-style weightlifting. Each style has its own principal injuries, both acute and chronic, related to the individual technique. Acute injuries should be further categorized as emergent or nonemergent. Specific age-related populations (i.e., the very young and the aging athlete) carry additional considerations.
Saturation-inversion-recovery: A method for T1 measurement
NASA Astrophysics Data System (ADS)
Wang, Hongzhi; Zhao, Ming; Ackerman, Jerome L.; Song, Yiqiao
2017-01-01
Spin-lattice relaxation (T1) has always been measured by inversion-recovery (IR), saturation-recovery (SR), or related methods. These existing methods share a common behavior in that the function describing T1 sensitivity is the exponential, e.g., exp(- τ /T1), where τ is the recovery time. In this paper, we describe a saturation-inversion-recovery (SIR) sequence for T1 measurement with considerably sharper T1-dependence than those of the IR and SR sequences, and demonstrate it experimentally. The SIR method could be useful in improving the contrast between regions of differing T1 in T1-weighted MRI.
Hahs-Vaughn, Debbie L; McWayne, Christine M; Bulotsky-Shearer, Rebecca J; Wen, Xiaoli; Faria, Ann-Marie
2011-06-01
Complex survey data are collected by means other than simple random samples. This creates two analytical issues: nonindependence and unequal selection probability. Failing to address these issues results in underestimated standard errors and biased parameter estimates. Using data from the nationally representative Head Start Family and Child Experiences Survey (FACES; 1997 and 2000 cohorts), three diverse multilevel models are presented that illustrate differences in results depending on addressing or ignoring the complex sampling issues. Limitations of using complex survey data are reported, along with recommendations for reporting complex sample results. © The Author(s) 2011
Theoretical study of the ionospheric G factor
NASA Technical Reports Server (NTRS)
Hagenbuch, K. M.
1972-01-01
A derivation from kinetic theory of the energy balance equation used in wave interaction work is reviewed. Then G is defined and two models for G are presented: one, a model based on Gerjuoy-Stein cross sections for both O2 and N2; the other based on a more recent model for O2 cross sections. The two models differ considerably in their temperature dependence. The limits of applicability of the useful energy balance equation (hence of the concept of G) are discussed and it is found that no difficulty arises unless the transmitter power is more than 1000 times that now employed at the present operating frequency.
NASA Technical Reports Server (NTRS)
Beratan, David N.
1989-01-01
The presence of conjugation and substitution defects introduces gap states in finite polyenes that are shown to influence the size and sign of the second molecular hyperpolarizability (SMH). Using a one-electron tight-binding model, the dependence of SMH on the defect-state occupancy and energy in finite polyenes is calculated. Defects can cause a significant decrease or enhancement of SMH by impeding charge delocalization or by creating partly filled bands (mimicking the one-band limit), respectively. Concomitant sign changes in SMH are predicted. Calculation results suggest strategies for designing molecules that can be either photochemically or electrochemically switched between states with considerably different SMHs.
Investigation of matter-antimatter interaction for possible propulsion applications
NASA Technical Reports Server (NTRS)
Morgan, D. L., Jr.
1974-01-01
Matter-antimatter annihilation is discussed as a means of rocket propulsion. The feasibility of different means of antimatter storage is shown to depend on how annihilation rates are affected by various circumstances. The annihilation processes are described, with emphasis on important features of atom-antiatom interatomic potential energies. A model is developed that allows approximate calculation of upper and lower bounds to the interatomic potential energy for any atom-antiatom pair. Formulae for the upper and lower bounds for atom-antiatom annihilation cross-sections are obtained and applied to the annihilation rates for each means of antimatter storage under consideration. Recommendations for further studies are presented.
A comparative study of interface reconstruction methods for multi-material ALE simulations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kucharik, Milan; Garimalla, Rao; Schofield, Samuel
2009-01-01
In this paper we compare the performance of different methods for reconstructing interfaces in multi-material compressible flow simulations. The methods compared are a material-order-dependent Volume-of-Fluid (VOF) method, a material-order-independent VOF method based on power diagram partitioning of cells and the Moment-of-Fluid method (MOF). We demonstrate that the MOF method provides the most accurate tracking of interfaces, followed by the VOF method with the right material ordering. The material-order-independent VOF method performs some-what worse than the above two while the solutions with VOF using the wrong material order are considerably worse.
Power and weight considerations in small, agile quadrotors
NASA Astrophysics Data System (ADS)
Mulgaonkar, Yash; Whitzer, Michael; Morgan, Brian; Kroninger, Christopher M.; Harrington, Aaron M.; Kumar, Vijay
2014-06-01
The development of autonomous Micro Aerial Vehicles (MAVs) is significantly constrained by their size, weight and power consumption. In this paper, we explore the energetics of quadrotor platforms and study the scaling of mass, inertia, lift and drag with their characteristic length. The effects of length scale on masses and inertias associated with various components are also investigated. Additionally, a study of Lithium Polymer battery performance is presented in terms of specific power and specific energy. Finally, we describe the power and energy consumption for different quadrotors and explore the dependence on size and mass for static hover tests as well as representative maneuvers.
Methyltestosterone-induced transient hyperthyroidism in a hypothyroid patient.
Krysiak, R; Okopien, B
2013-01-01
In this paper we report different effects of methyltestosterone administration on thyroid function in two twin brothers, one of whom suffered from hypothyroidism, while the other was apparently healthy. Methyltestosterone, which is a non-aromatisable androgen, resulted in a marked reduction of thyroxine-binding globulin (TBG), irrespectively of the patient's hormonal status, while the impact on free thyroid hormones depended on baseline thyroid function. Our research shows that a possibility of the use of non-aromatisable androgens or other drugs affecting TBG levels should be taken into consideration in all hypothyroid patients receiving levothyroxine, in whom thyroid hormone status suddenly changes without any apparent reason.
Solving time-dependent two-dimensional eddy current problems
NASA Technical Reports Server (NTRS)
Lee, Min Eig; Hariharan, S. I.; Ida, Nathan
1988-01-01
Results of transient eddy current calculations are reported. For simplicity, a two-dimensional transverse magnetic field which is incident on an infinitely long conductor is considered. The conductor is assumed to be a good but not perfect conductor. The resulting problem is an interface initial boundary value problem with the boundary of the conductor being the interface. A finite difference method is used to march the solution explicitly in time. The method is shown. Treatment of appropriate radiation conditions is given special consideration. Results are validated with approximate analytic solutions. Two stringent test cases of high and low frequency incident waves are considered to validate the results.
2006-05-25
This places it somewhere between the Structuralist and Dependency schools. International Political Economy theory balances between the Marxist and...does not portend to provide that explanation, but rather seeks to provide considerations for study in developmental theory and for United States...of globalization. Historic and contemporary developmental theories are insufficient in that they fail to account for societal characteristics in
Blanco, Carlos; García-Anaya, María; Wall, Melanie; de los Cobos, José Carlos Pérez; Swierad, Ewelina; Wang, Shuai; Petry, Nancy M.
2015-01-01
Objective Pathological gambling (PG) is now aligned with substance use disorders in the DSM-5 as the first officially recognized behavioral addiction. There is growing interest in examining obesity as an addictive disorder as well. The goal of this study was to investigate whether epidemiological data provide support for the consideration of PG and obesity as addictive disorders. Method Factor analysis of data from a large, nationally representative sample of US adults (N=43,093), using nicotine dependence, alcohol dependence, drug dependence, PG and obesity as indicators. It was hypothesized that nicotine dependence, alcohol dependence and drug use dependence would load on a single factor. It was further hypothesized that if PG and obesity were addictive disorders, they would load on the same factor as substance use disorders, whereas failure to load on the addictive factor would not support their conceptualization as addictive disorders. Results A model with one factor including nicotine dependence, alcohol dependence, drug dependence and PG, but not obesity, provided a very good fit to the data, as indicated by CFI=0.99, TLI=0.99 and RMSEA=.01 and loadings of all indicators >0.4. Conclusion Data from this study support the inclusion of PG in a latent factor with substance use disorders but do not lend support to the consideration of obesity, as defined by BMI, as an addictive disorder. Future research should investigate whether certain subtypes of obesity are best conceptualized as addictive disorders and the shared biological and environmental factors that account for the common and specific features of addictive disorders. PMID:25769392
Analysis of key thresholds leading to upstream dependencies in global transboundary water bodies
NASA Astrophysics Data System (ADS)
Munia, Hafsa Ahmed; Guillaume, Joseph; Kummu, Matti; Mirumachi, Naho; Wada, Yoshihide
2017-04-01
Transboundary water bodies supply 60% of global fresh water flow and are home to about 1/3 of the world's population; creating hydrological, social and economic interdependencies between countries. Trade-offs between water users are delimited by certain thresholds, that, when crossed, result in changes in system behavior, often related to undesirable impacts. A wide variety of thresholds are potentially related to water availability and scarcity. Scarcity can occur because of the country's own water use, and that is potentially intensified by upstream water use. In general, increased water scarcity escalates the reliance on shared water resources, which increases interdependencies between riparian states. In this paper the upstream dependencies of global transboundary river basins are examined at the scale of sub-basin areas. We aim to assess how upstream water withdrawals cause changes in the scarcity categories, such that crossing thresholds is interpreted in terms of downstream dependency on upstream water availability. The thresholds are defined for different types of water availability on which a sub-basin relies: - reliable local runoff (available even in a dry year), - less reliable local water (available in the wet year), - reliable dry year inflows from possible upstream area, and - less reliable wet year inflows from upstream. Possible upstream withdrawals reduce available water downstream, influencing the latter two water availabilities. Upstream dependencies have then been categorized by comparing a sub-basin's scarcity category across different water availability types. When population (or water consumption) grows, the sub-basin satisfies its needs using less reliable water. Thus, the factors affecting the type of water availability being used are different not only for each type of dependency category, but also possibly for every sub- basin. Our results show that, in the case of stress (impacts from high use of water), in 104 (12%) sub- basins out of 886 sub-basins are dependent on upstream water, while in the case of shortage (impacts from insufficient water availability per person), 79 (9%) sub-basins out of 886 sub-basins dependent on upstream water. Categorization of the upstream dependency of the sub-basins helps to differentiate between areas where i) there is currently no dependency on upstream water, ii) upstream water withdrawals are sufficiently high that they alter the scarcity and dependency status, and iii) which are always dependent on upstream water regardless of upstream water withdrawals. Our dependency assessment is expected to considerably support the studies and discussions of hydro-political power relations and management practices in transboundary basins.
Spatial variation and density-dependent dispersal in competitive coexistence.
Amarasekare, Priyanga
2004-01-01
It is well known that dispersal from localities favourable to a species' growth and reproduction (sources) can prevent competitive exclusion in unfavourable localities (sinks). What is perhaps less well known is that too much emigration can undermine the viability of sources and cause regional competitive exclusion. Here, I investigate two biological mechanisms that reduce the cost of dispersal to source communities. The first involves increasing the spatial variation in the strength of competition such that sources can withstand high rates of emigration; the second involves reducing emigration from sources via density-dependent dispersal. I compare how different forms of spatial variation and modes of dispersal influence source viability, and hence source-sink coexistence, under dominance and pre-emptive competition. A key finding is that, while spatial variation substantially reduces dispersal costs under both types of competition, density-dependent dispersal does so only under dominance competition. For instance, when spatial variation in the strength of competition is high, coexistence is possible (regardless of the type of competition) even when sources experience high emigration rates; when spatial variation is low, coexistence is restricted even under low emigration rates. Under dominance competition, density-dependent dispersal has a strong effect on coexistence. For instance, when the emigration rate increases with density at an accelerating rate (Type III density-dependent dispersal), coexistence is possible even when spatial variation is quite low; when the emigration rate increases with density at a decelerating rate (Type II density-dependent dispersal), coexistence is restricted even when spatial variation is quite high. Under pre-emptive competition, density-dependent dispersal has only a marginal effect on coexistence. Thus, the diversity-reducing effects of high dispersal rates persist under pre-emptive competition even when dispersal is density dependent, but can be significantly mitigated under dominance competition if density-dependent dispersal is Type III rather than Type II. These results lead to testable predictions about source-sink coexistence under different regimes of competition, spatial variation and dispersal. They identify situations in which density-independent dispersal provides a reasonable approximation to species' dispersal patterns, and those under which consideration of density-dependent dispersal is crucial to predicting long-term coexistence. PMID:15306322
Modelling regional variability of irrigation requirements due to climate change in Northern Germany.
Riediger, Jan; Breckling, Broder; Svoboda, Nikolai; Schröder, Winfried
2016-01-15
The question whether global climate change invalidates the efficiency of established land use practice cannot be answered without systemic considerations on a region specific basis. In this context plant water availability and irrigation requirements, respectively, were investigated in Northern Germany. The regions under investigation--Diepholz, Uelzen, Fläming and Oder-Spree--represent a climatic gradient with increasing continentality from West to East. Besides regional climatic variation and climate change, soil conditions and crop management differ on the regional scale. In the model regions, temporal seasonal droughts influence crop success already today, but on different levels of intensity depending mainly on climate conditions. By linking soil water holding capacities, crop management data and calculations of evapotranspiration and precipitation from the climate change scenario RCP 8.5 irrigation requirements for maintaining crop productivity were estimated for the years 1991 to 2070. Results suggest that water requirement for crop irrigation is likely to increase with considerable regional variation. For some of the regions, irrigation requirements might increase to such an extent that the established regional agricultural practice might be hard to retain. Where water availability is limited, agricultural practice, like management and cultivated crop spectrum, has to be changed to deal with the new challenges. Copyright © 2015 Elsevier B.V. All rights reserved.
[Guidelines for wise utilization of knee imaging].
Finestone, Aharon S; Eshed, Iris; Freedman, Yehuda; Beer, Yiftah; Bar-Sever, Zvi; Kots, Yavvgeni; Adar, Eliyahu; Mann, Gideon
2012-02-01
The knee is a complex structure afflicted with diverse pathologies. Correct management of knee complaints demands wise utilization of imaging modalities, considering their accuracy in the specific clinical situation, the patient's safety and availability and financial issues. Some of these considerations are universal, while others are local, depending on medical and insurance systems. There is controversy and unclearness regarding the best imaging modality in different clinical situations. To develop clinical guidelines for utilizing knee imaging. Leading physicians in specialties associated with knee disease and imaging were invited to participate in a panel on the guidelines. Controversies were settled in the main panel or in sub-panels. The panel agreed on the principles in choosing from the various modalities, primarily medical accuracy, followed by patient safety, availability and cost. There was agreement that the physician is responsible to choose the most appropriate diagnostic tool, consulting, when necessary, on the advantages, limitations and risks of the various imaging modalities. A comprehensive table was compiled with the importance of the different imaging modalities in various clinical situations. For the first time, Israeli guidelines on wise utilization of knee imaging are presented. They take into consideration the clinical situations and also availability and financial issues specific to Israel. These guidelines will serve physicians of several disciplines and medical insurers to improve patient management efficiently.
Organic SIMS: the influence of time on the ion yield enhancement by silver and gold deposition
NASA Astrophysics Data System (ADS)
Adriaensen, L.; Vangaever, F.; Gijbels, R.
2004-06-01
A series of organic dyes and pharmaceuticals was used to study the secondary ion yield enhancement by metal deposition. The molecules were dissolved in methanol and spincasted on silicon substrates. Subsequently, silver or gold was evaporated on the samples to produce a very thin coating. The coated samples, when measured with TOF-SIMS, showed a considerable increase in characteristic secondary ion intensity. Gold-evaporated samples appear to exhibit the highest signal enhancement. These observations apply to organic samples in general, an advantage that allows to use the technique of metal deposition on real-world samples. However, the observed signal increase does not occur at any given moment. The time between metal deposition on the sample surface and the measuring of the sample with TOF-SIMS appears to have an important influence on the enhancement of the secondary ion intensities. In consideration of these observations several experiments were carried out, in which the spincasted samples were measured at different times after sample preparation, i.e., after gold or silver was deposited on the sample surface. The results show that, depending on the sample and the metal deposited, the secondary ion signals reach their maximum at different times. Further study will be necessary to detect the mechanism responsible for the observed enhancement effect.
ERIC Educational Resources Information Center
Ingersoll, Gary M.; And Others
1990-01-01
Comparison of the beliefs and attitudes of a sample of pediatric residents (n=56) and practicing physicians (n=1,500) concerning children with insulin-dependent Diabetes Mellitus and the disease itself found residents in their second and third years of training considerably more negative about both than physicians or first-year residents.…
ERIC Educational Resources Information Center
Kleim, Jeffrey A.; Jones, Theresa A.
2008-01-01
Purpose: This paper reviews 10 principles of experience-dependent neural plasticity and considerations in applying them to the damaged brain. Method: Neuroscience research using a variety of models of learning, neurological disease, and trauma are reviewed from the perspective of basic neuroscientists but in a manner intended to be useful for the…
Huss, Magnus; Gårdmark, Anna; Van Leeuwen, Anieke; de Roos, André M
2012-04-01
Patterns of coexistence among competing species exhibiting size- and food-dependent growth remain largely unexplored. Here we studied mechanisms behind coexistence and shifts in competitive dominance in a size-structured fish guild, representing sprat and herring stocks in the Baltic Sea, using a physiologically structured model of competing populations. The influence of degree of resource overlap and the possibility of undergoing ontogenetic diet shifts were studied as functions of zooplankton and zoobenthos productivity. By imposing different size-dependent mortalities, we could study the outcome of competition under contrasting environmental regimes representing poor and favorable growth conditions. We found that the identity of the dominant species shifted between low and high productivity. Adding a herring-exclusive benthos resource only provided a competitive advantage over sprat when size-dependent mortality was high enough to allow for rapid growth in the zooplankton niche. Hence, the importance of a bottom-up effect of varying productivity was dependent on a strong top-down effect. Although herring could depress shared resources to lower levels than could sprat and also could access an exclusive resource, the smaller size at maturation of sprat allowed it to coexist with herring and, in some cases, exclude it. Our model system, characterized by interactions among size cohorts, allowed for consumer coexistence even at full resource overlap at intermediate productivities when size-dependent mortality was low. Observed shifts in community patterns were crucially dependent on the explicit consideration of size- and food-dependent growth. Accordingly, we argue that accounting for food-dependent growth and size-dependent interactions is necessary to better predict changes in community structure and dynamics following changes in major ecosystem drivers such as resource productivity and mortality, which are fundamental for our ability to manage exploitation of living resources in, e.g., fisheries.
About Block Dynamic Model of Earthquake Source.
NASA Astrophysics Data System (ADS)
Gusev, G. A.; Gufeld, I. L.
One may state the absence of a progress in the earthquake prediction papers. The short-term prediction (diurnal period, localisation being also predicted) has practical meaning. Failure is due to the absence of the adequate notions about geological medium, particularly, its block structure and especially in the faults. Geological and geophysical monitoring gives the basis for the notion about geological medium as open block dissipative system with limit energy saturation. The variations of the volume stressed state close to critical states are associated with the interaction of the inhomogeneous ascending stream of light gases (helium and hydrogen) with solid phase, which is more expressed in the faults. In the background state small blocks of the fault medium produce the sliding of great blocks in the faults. But for the considerable variations of ascending gas streams the formation of bound chains of small blocks is possible, so that bound state of great blocks may result (earthquake source). Recently using these notions we proposed a dynamical earthquake source model, based on the generalized chain of non-linear bound oscillators of Fermi-Pasta-Ulam type (FPU). The generalization concerns its in homogeneity and different external actions, imitating physical processes in the real source. Earlier weak inhomogeneous approximation without dissipation was considered. Last has permitted to study the FPU return (return to initial state). Probabilistic properties in quasi periodic movement were found. The chain decay problem due to non-linearity and external perturbations was posed. The thresholds and dependence of life- time of the chain are studied. The great fluctuations of life-times are discovered. In the present paper the rigorous consideration of the inhomogeneous chain including the dissipation is considered. For the strong dissipation case, when the oscillation movements are suppressed, specific effects are discovered. For noise action and constantly arising deformation the dependence of life-time on noise amplitude is investigated. Also for the initial shock we have chosen the amplitudes, when it determined the life-time, as principal cause. For this case it appeared, that life-time had non-monotonous dependence on the noise amplitude ("temperature"). There was the domain of the "temperatures", where the life-time reached a maximum. The comparison of different dissipation intensities was performed.
NASA Astrophysics Data System (ADS)
Biswas, A.; Lotha, S.; Gupta, R.; Avasthi, D. K.; Paul, S. N.
2002-04-01
Thin films (13 μm) of polyethelene terephthalate (PET) are irradiated by different swift metallic heavy ions (180 MeV Ag14+ and 200 MeV Au15+) with the projectile linear energy transfer (LET) (˜10-14 keV/nm), respectively. LET dependence on the molecular structural changes in PFT irradiated at different ion fluences has been studied by the Fourier transform infrared spectroscopy. The study has revealed that beyond a critical LET entirely different pathways of amorphization beginning with partial recrystallization at lower ion fluence impact occurs in PET, contrary to the earlier established results. At considerably higher LET (˜14 keV/nm), the most characteristic crystalline stretching and bending vibration bands such as at 850 cm-1 (CH2 rocking), 972 cm-1 (C=O stretching), 1341 and 1471 cm-1 (CH2 bending) in PET have shown a significant rise in the respective infrared absorbance intensities upon lower ion fluence (˜1011 ions/cm2) impact. The absence of previously reported unsaturations such as alkynes at both the LET beam used are also observed. Interestingly, the aromatic system also appears to be unstable and participating in the modification process, particularly at the higher LET (˜14 KeV/nm). Possible interpretations are discussed.
NASA Astrophysics Data System (ADS)
Marsh, Jonathan; Zhang, Yang; Verma, Devendra; Biswas, Sudipta; Haque, Aman; Tomar, Vikas
2015-12-01
Zirconium alloys for nuclear applications with different microstructures were produced by manufacturing processes such as chipping, rolling and annealing. The two Zr samples, rolled and rolled-annealed were subjected to different levels of irradiation, 1 keV and 100 eV, to study the effect of irradiation dosages. The effect of microstructure and irradiation on the mechanical properties (reduced modulus, hardness, indentation yield strength) was analyzed with nanoindentation experiments, which were carried out in the temperature range of 25°C to 450°C to investigate temperature dependence. An indentation size effect analysis was performed and the mechanical properties were also corrected for the oxidation effects at high temperatures. The irradiation-induced hardness was observed, with rolled samples exhibiting higher increase compared to rolled and annealed samples. The relevant material parameters of the Anand viscoplastic model were determined for Zr samples containing different level of irradiation to account for viscoplasticity at high temperatures. The effect of the microstructure and irradiation on the stress-strain curve along with the influence of temperature on the mechanisms of irradiation creep such as formation of vacancies and interstitials is presented. The yield strength of irradiated samples was found to be higher than the unirradiated samples which also showed a decreasing trend with the temperature.
Lyytikäinen, Laura; Kemppainen, Teemu
2016-07-01
Using the data from the European Social Survey (round 6, 2012), this article studies regional inequalities in self-rated health in Russia and examines the role that socio-demographic factors and economic and social capital play in these differences. Also, the regional variation in the determinants of self-rated health is analysed. The article argues that there are considerable and statistically significant unadjusted differences in self-rated health across Russian Federal Districts. We elaborated these differences by regression adjustments, with the result that some of the differences were explained by our predictors and some were amplified. The odds for good self-rated health were lower in the Volga than in Central Russia due to age and socio-economic composition. In contrast, the regression adjustments amplified the differences of the Northwest and the South in comparison to the Central District. The odds for good self-rated health were considerably lower in the Far Eastern part of the country than in the Central District, independently of the adjustments. While social and economic capital predicted good self-rated health at the individual level, they did not explain regional differences. Interaction analyses revealed regional variation in some of the determinants of self-rated health. Most notably, the effects of age, trade union membership and volunteering depended on the regional context. This article argues that the healthcare reforms that transfer funding responsibilities to regional administration may be dangerous for the already less affluent and less healthy rural regions. Thus, regional governance has a growing importance in preventing increases in health inequalities. Copyright © 2016 Elsevier Ltd. All rights reserved.
Drug-induced QT interval prolongation: does ethnicity of the thorough QT study population matter?
Shah, Rashmi R
2013-01-01
Inter-ethnic differences in drug responses have been well documented. Drug-induced QT interval prolongation is a major safety concern and therefore, regulatory authorities recommend a clinical thorough QT study (TQT) to investigate new drugs for their QT-prolonging potential. A positive study, determined by breach of a preset regulatory threshold, significantly influences late phase clinical trials by requiring intense ECG monitoring. A few studies that are currently available, although not statistically conclusive at present, question the assumption that ethnicity of the study population may not influence the outcome of a TQT study. Collective consideration of available pharmacogenetic and clinical information suggests that there may be inter-ethnic differences in QT-prolonging effects of drugs and that Caucasians may be more sensitive than other populations. The information also suggest s that (a) these differences may depend on the QT-prolonging potency of the drug and (b) exposure–response (E–R) analysis may be more sensitive than simple changes in QTc interval in unmasking this difference. If the QT response in Caucasians is generally found to be more intense than in non-Caucasians, there may be significant regulatory implications for domestic acceptance of data from a TQT study conducted in foreign populations. However, each drug will warrant an individual consideration when extrapolating the results of a TQT studyfrom one ethnic population to another and the ultimate clinical relevance of any difference. Further adequately designed and powered studies, investigating the pharmacologic properties and E–R relationships of additional drugs with different potencies, are needed in Caucasians, Oriental/Asian and African populations before firm conclusions can be drawn. PMID:22882246
Niinemets, Ülo; Sun, Zhihong; Talts, Eero
2018-01-01
Leaf age alters the balance between the use of end-product of plastidic isoprenoid synthesis pathway, dimethylallyl diphosphate (DMADP), in prenyltransferase reactions leading to synthesis of pigments of photosynthetic machinery and in isoprene synthesis, but the implications of such changes on environmental responses of isoprene emission have not been studied. Because under light-limited conditions, isoprene emission rate is controlled by DMADP pool size (SDMADP), shifts in the share of different processes are expected to particularly strongly alter the light dependency of isoprene emission. We examined light responses of isoprene emission in young fully-expanded, mature and old non-senescent leaves of hybrid aspen (Populus tremula x P. tremuloides) and estimated in vivo SDMADP and isoprene synthase activity from postillumination isoprene release. Isoprene emission capacity was 1.5-fold larger in mature than in young and old leaves. The initial quantum yield of isoprene emission (αI) increased by 2.5-fold with increasing leaf age primarily as the result of increasing SDMADP. The saturating light intensity (QI90) decreased by 2.3-fold with increasing leaf age, and this mainly reflected limited light-dependent increase of SDMADP possibly due to feedback inhibition by DMADP. These major age-dependent changes in the shape of the light response need consideration in modeling canopy isoprene emission. PMID:26037962
Niinemets, Ülo; Sun, Zhihong; Talts, Eero
2015-12-01
Leaf age alters the balance between the use of end-product of plastidic isoprenoid synthesis pathway, dimethylallyl diphosphate (DMADP), in prenyltransferase reactions leading to synthesis of pigments of photosynthetic machinery and in isoprene synthesis, but the implications of such changes on environmental responses of isoprene emission have not been studied. Because under light-limited conditions, isoprene emission rate is controlled by DMADP pool size (SDMADP ), shifts in the share of different processes are expected to particularly strongly alter the light dependency of isoprene emission. We examined light responses of isoprene emission in young fully expanded, mature and old non-senescent leaves of hybrid aspen (Populus tremula x P. tremuloides) and estimated in vivo SDMADP and isoprene synthase activity from post-illumination isoprene release. Isoprene emission capacity was 1.5-fold larger in mature than in young and old leaves. The initial quantum yield of isoprene emission (αI ) increased by 2.5-fold with increasing leaf age primarily as the result of increasing SDMADP . The saturating light intensity (QI90 ) decreased by 2.3-fold with increasing leaf age, and this mainly reflected limited light-dependent increase of SDMADP possibly due to feedback inhibition by DMADP. These major age-dependent changes in the shape of the light response need consideration in modelling canopy isoprene emission. © 2015 John Wiley & Sons Ltd.
NASA Astrophysics Data System (ADS)
Kalb, Wolfgang L.; Batlogg, Bertram
2010-01-01
The spectral density of localized states in the band gap of pentacene (trap DOS) was determined with a pentacene-based thin-film transistor from measurements of the temperature dependence and gate-voltage dependence of the contact-corrected field-effect conductivity. Several analytical methods to calculate the trap DOS from the measured data were used to clarify, if the different methods lead to comparable results. We also used computer simulations to further test the results from the analytical methods. Most methods predict a trap DOS close to the valence-band edge that can be very well approximated by a single exponential function with a slope in the range of 50-60 meV and a trap density at the valence-band edge of ≈2×1021eV-1cm-3 . Interestingly, the trap DOS is always slightly steeper than exponential. An important finding is that the choice of the method to calculate the trap DOS from the measured data can have a considerable effect on the final result. We identify two specific simplifying assumptions that lead to significant errors in the trap DOS. The temperature dependence of the band mobility should generally not be neglected. Moreover, the assumption of a constant effective accumulation-layer thickness leads to a significant underestimation of the slope of the trap DOS.
NASA Astrophysics Data System (ADS)
de Argandoña, Eneko Saenz; Mendiguren, Joseba; Otero, Irune; Mugarra, Endika; Otegi, Nagore; Galdos, Lander
2018-05-01
Steel has been used in vehicles from the automotive industry's inception. Different steel grades are continually being developed in order to satisfy new fuel economy requirements. For example, advanced high strength steel grades (AHSS) are widely used due to their good strength/weight ratio. Because each steel grade has a different microstructure composition and hardness, they show different behaviors when they are subjected to different strain paths. Similarly, the friction behavior when using different contact pressures is considerably altered. In the present paper, four different steel grades, ZSt380, DP600, DP780 and Fortiform 1050 materials are deeply characterized using uniaxial and cyclic tension-compression tests. Coefficient of friction (COF) is also obtained using strip drawing tests. These results have been used to calibrate mixed kinematic-hardening material models as well as pressure dependent friction models. Finally, the geometrical accuracy of the different material and friction models has been evaluated by comparing the numerical predictions with experimental demonstrators obtained using a U-Drawing tester.
A porous flow approach to model thermal non-equilibrium applicable to melt migration
NASA Astrophysics Data System (ADS)
Schmeling, Harro; Marquart, Gabriele; Grebe, Michael
2018-01-01
We develop an approach for heat exchange between a fluid and a solid phase of a porous medium where the temperatures of the fluid and matrix are not in thermal equilibrium. The formulation considers moving of the fluid within a resting or deforming porous matrix in an Eulerian coordinate system. The approach can be applied, for example, to partially molten systems or to brine transport in porous rocks. We start from an existing theory for heat exchange where the energy conservation equations for the fluid and the solid phases are separated and coupled by a heat exchange term. This term is extended to account for the full history of heat exchange. It depends on the microscopic geometry of the fluid phase. For the case of solid containing hot, fluid-filled channels, we derive an expression based on a time-dependent Fourier approach for periodic half-waves. On the macroscopic scale, the temporal evolution of the heat exchange leads to a convolution integral along the flow path of the solid, which simplifies considerably in case of a resting matrix. The evolution of the temperature in both phases with time is derived by inserting the heat exchange term into the energy equations. We explore the effects of thermal non-equilibrium between fluid and solid by considering simple cases with sudden temperature differences between fluid and solid as initial or boundary conditions, and by varying the fluid velocity with respect to the resting porous solid. Our results agree well with an analytical solution for non-moving fluid and solid. The temperature difference between solid and fluid depends on the Peclet number based on the Darcy velocity. For Peclet numbers larger than 1, the temperature difference after one diffusion time reaches 5 per cent of \\tilde{T} or more (\\tilde{T} is a scaling temperature, e.g. the initial temperature difference). Thus, our results imply that thermal non-equilibrium can play an important role for melt migration through partially molten systems where melt focuses into melt channels near the transition to melt ascent by dykes. Our method is based on solving the convolution integration for the heat exchange over the full flow history, which is numerically expensive. We tested to replace the heat exchange term by an instantaneous, approximate term. We found considerable errors on the short timescale, but a good agreement on the long timescale if appropriate parameters for the approximate terms are used. We derived these parameters which may be implemented in fully dynamical two-phase flow formulations of melt migration in the Earth.
Magnon dispersion in thin magnetic films.
Balashov, T; Buczek, P; Sandratskii, L; Ernst, A; Wulfhekel, W
2014-10-01
Although the dispersion of magnons has been measured in many bulk materials, few studies deal with the changes in the dispersion when the material is in the form of a thin film, a system that is of interest for applications. Here we review inelastic tunneling spectroscopy studies of magnon dispersion in Mn/Cu3Au(1 0 0) and present new studies on Co and Ni thin films on Cu(1 0 0). The dispersion in Mn and Co films closely follows the dispersion of bulk samples with negligible dependence on thickness. The lifetime of magnons depends slightly on film thickness, and decreases considerably as the magnon energy increases. In Ni/Cu(1 0 0) films the thickness dependence of dispersion is much more pronounced. The measurements indicate a considerable mode softening for thinner films. Magnon lifetimes decrease dramatically near the edge of the Brillouin zone due to a close proximity of the Stoner continuum. The experimental study is supported by first-principles calculations.
Vliegen, Nicole; Luyten, Patrick; Besser, Avi; Casalin, Sara; Kempke, Stefan; Tang, Eileen
2010-01-01
This prospective longitudinal study investigated the role of the personality dimensions of dependency and self-criticism in the course of depressive symptoms in a sample of inpatient severely postpartum depressed mothers (n = 55). Depressive symptoms and personality were measured during hospitalization and on average 3 1/2 years later. In line with previous research, a considerable subgroup of mothers (39%) reported moderate to severe symptoms of depression at time 2. In addition, although these mothers did not exhibit more depressive episodes during follow-up period compared with mothers with a less chronic course of depression, their depressive episodes were considerably longer, and they had higher levels of severity of depression as well as of dependency and self-criticism at Time 1. Finally, self-criticism, but not dependency, assessed at Time 1, predicted both depression diagnosis and levels of depression at follow-up, supporting a vulnerability model positing that self-criticism confers vulnerability for depression over time.
Consistent individual differences in human social learning strategies.
Molleman, Lucas; van den Berg, Pieter; Weissing, Franz J
2014-04-04
Social learning has allowed humans to build up extensive cultural repertoires, enabling them to adapt to a wide variety of environmental and social conditions. However, it is unclear which social learning strategies people use, especially in social contexts where their payoffs depend on the behaviour of others. Here we show experimentally that individuals differ in their social learning strategies and that they tend to employ the same learning strategy irrespective of the interaction context. Payoff-based learners focus on their peers' success, while decision-based learners disregard payoffs and exclusively focus on their peers' past behaviour. These individual differences may be of considerable importance for cultural evolution. By means of a simple model, we demonstrate that groups harbouring individuals with different learning strategies may be faster in adopting technological innovations and can be more efficient through successful role differentiation. Our study highlights the importance of individual variation for human interactions and sheds new light on the dynamics of cultural evolution.
Who we were and who we will be: the temporal context of women's in-group stereotype content.
Morton, Thomas A; Rabinovich, Anna; Postmes, Tom
2012-06-01
Research has elaborated considerably on the dimensions of out-group stereotype content and on the origins and functions of different content combinations. Less attention has been given to the origins and functions of in-group stereotype content. We argue that in-group stereotypes are likely to serve different social identity functions, and thus attract different content, dependent on individual differences in in-group identification and on the temporal perspective of the perceiver. Two studies (Ns = 43 and 93) found that women's in-group stereotype content varied as a function of gender group identification and temporal perspective. When the past was primed, highly identified women generated stereotypes that emphasized the warmth (but not competence) of their group. When the future was primed, highly identified women generated stereotypes that emphasized the competence (as well as warmth) of their group. These results are discussed in terms of the use of stereotypes for social creativity versus social change. © 2012 The British Psychological Society.
de Keyser, Catherine E; Leening, Maarten J G; Romio, Silvana A; Jukema, J Wouter; Hofman, Albert; Ikram, M Arfan; Franco, Oscar H; Stijnen, Theo; Stricker, Bruno H
2014-11-01
When studying the causal effect of drug use in observational data, marginal structural modeling (MSM) can be used to adjust for time-dependent confounders that are affected by previous treatment. The objective of this study was to compare traditional Cox proportional hazard models (with and without time-dependent covariates) with MSM to study causal effects of time-dependent drug use. The example of primary prevention of cardiovascular disease (CVD) with statins was examined using up to 17.7 years of follow-up from 4,654 participants of the observational prospective population-based Rotterdam Study. In the MSM model, the weight was based on measurements of established cardiovascular risk factors and co-morbidity. In general, we could not demonstrate important differences in results from the Cox models and MSM. Results from analysis on duration of statin use suggested that substantial residual confounding by indication was not accounted for during the period shortly after statin initiation. In conclusion, although on theoretical grounds MSM is an elegant technique, lack of data on the precise time-dependent confounders, such as indication of treatment or other considerations of the prescribing physician jeopardizes the calculation of valid weights. Confounding remains a hurdle in observational effectiveness research on preventive drugs with a multitude of prescription determinants.
Self-consistent modeling of terahertz waveguide and cavity with frequency-dependent conductivity
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huang, Y. J.; Chu, K. R., E-mail: krchu@yahoo.com.tw; Thumm, M.
The surface resistance of metals, and hence the Ohmic dissipation per unit area, scales with the square root of the frequency of an incident electromagnetic wave. As is well recognized, this can lead to excessive wall losses at terahertz (THz) frequencies. On the other hand, high-frequency oscillatory motion of conduction electrons tends to mitigate the collisional damping. As a result, the classical theory predicts that metals behave more like a transparent medium at frequencies above the ultraviolet. Such a behavior difference is inherent in the AC conductivity, a frequency-dependent complex quantity commonly used to treat electromagnetics of metals at opticalmore » frequencies. The THz region falls in the gap between microwave and optical frequencies. However, metals are still commonly modeled by the DC conductivity in currently active vacuum electronics research aimed at the development of high-power THz sources (notably the gyrotron), although a small reduction of the DC conductivity due to surface roughness is sometimes included. In this study, we present a self-consistent modeling of the gyrotron interaction structures (a metallic waveguide or cavity) with the AC conductivity. The resulting waveguide attenuation constants and cavity quality factors are compared with those of the DC-conductivity model. The reduction in Ohmic losses under the AC-conductivity model is shown to be increasingly significant as the frequency reaches deeper into the THz region. Such effects are of considerable importance to THz gyrotrons for which the minimization of Ohmic losses constitutes a major design consideration.« less
Sampling procedures for throughfall monitoring: A simulation study
NASA Astrophysics Data System (ADS)
Zimmermann, Beate; Zimmermann, Alexander; Lark, Richard Murray; Elsenbeer, Helmut
2010-01-01
What is the most appropriate sampling scheme to estimate event-based average throughfall? A satisfactory answer to this seemingly simple question has yet to be found, a failure which we attribute to previous efforts' dependence on empirical studies. Here we try to answer this question by simulating stochastic throughfall fields based on parameters for statistical models of large monitoring data sets. We subsequently sampled these fields with different sampling designs and variable sample supports. We evaluated the performance of a particular sampling scheme with respect to the uncertainty of possible estimated means of throughfall volumes. Even for a relative error limit of 20%, an impractically large number of small, funnel-type collectors would be required to estimate mean throughfall, particularly for small events. While stratification of the target area is not superior to simple random sampling, cluster random sampling involves the risk of being less efficient. A larger sample support, e.g., the use of trough-type collectors, considerably reduces the necessary sample sizes and eliminates the sensitivity of the mean to outliers. Since the gain in time associated with the manual handling of troughs versus funnels depends on the local precipitation regime, the employment of automatically recording clusters of long troughs emerges as the most promising sampling scheme. Even so, a relative error of less than 5% appears out of reach for throughfall under heterogeneous canopies. We therefore suspect a considerable uncertainty of input parameters for interception models derived from measured throughfall, in particular, for those requiring data of small throughfall events.
Hassan, Fatima Ismail; Niaz, Kamal; Khan, Fazlullah; Maqbool, Faheem; Abdollahi, Mohammad
2017-01-01
Rice is the major staple food for about two billion people living in Asia. It has been reported to contain considerable amount of inorganic arsenic which is toxic to pancreatic beta cells and disrupt glucose homeostasis. Articles and conference papers published between 1992 and 2017, indexed in Scopus, PubMed, EMBASE, Google, and Google scholar were used. Arsenic exposure has been associated with increased blood glucose and insulin levels, or decreased sensitization of insulin cells to glucose uptake. Several studies have shown the association between inorganic arsenic exposure and incidence of diabetes mellitus. Considerable amounts of arsenic have been reported in different types of rice which may be affected by cultivation methods, processing, and country of production. Use of certain microbes, fertilizers, and enzymes may reduce arsenic uptake or accumulation in rice, which may reduce its risk of toxicity. Combined exposure to contaminated rice, other foods and drinking water may increase the risk of diabetes in these countries. Maximum tolerated daily intake of arsenic contaminated rice (2.1 µg/day kg body weight) has been set by WHO, which may be exceeded depending on its content in rice and amount consumed. Hence, increased prevalence of diabetes in South Asia may be related to the consumption of arsenic contaminated rice depending on its content in the rice and daily amount consumed. In this review, we have focused on the possible relation between rice consumption, arsenic contamination, and prevalence of diabetes in South Asia. PMID:29285009
Structure Line Detection from LIDAR Point Clouds Using Topological Elevation Analysis
NASA Astrophysics Data System (ADS)
Lo, C. Y.; Chen, L. C.
2012-07-01
Airborne LIDAR point clouds, which have considerable points on object surfaces, are essential to building modeling. In the last two decades, studies have developed different approaches to identify structure lines using two main approaches, data-driven and modeldriven. These studies have shown that automatic modeling processes depend on certain considerations, such as used thresholds, initial value, designed formulas, and predefined cues. Following the development of laser scanning systems, scanning rates have increased and can provide point clouds with higher point density. Therefore, this study proposes using topological elevation analysis (TEA) to detect structure lines instead of threshold-dependent concepts and predefined constraints. This analysis contains two parts: data pre-processing and structure line detection. To preserve the original elevation information, a pseudo-grid for generating digital surface models is produced during the first part. The highest point in each grid is set as the elevation value, and its original threedimensional position is preserved. In the second part, using TEA, the structure lines are identified based on the topology of local elevation changes in two directions. Because structure lines can contain certain geometric properties, their locations have small relieves in the radial direction and steep elevation changes in the circular direction. Following the proposed approach, TEA can be used to determine 3D line information without selecting thresholds. For validation, the TEA results are compared with those of the region growing approach. The results indicate that the proposed method can produce structure lines using dense point clouds.
Brück, S; Strohmeier, J; Busch, D; Drozdzik, M; Oswald, S
2017-03-01
Induction or inhibition of drug transporting proteins by concomitantly administered drugs can cause serious drug-drug interactions (DDIs). However, in vitro assays currently available are mostly for studying the inhibitory potential of drugs on intestinal transporter proteins, rather than induction. Therefore, this study investigated the suitability of the frequently used intestinal Caco-2 cell line to predict transporter-mediated DDIs as caused by induction via activation of nuclear receptors. TaqMan® low density arrays and LC-MS/MS based targeted proteomics were used to evaluate transporter expression in Caco-2 cells in comparison with jejunal tissue, in culture-time dependence studies and after incubation with different known inducers of drug metabolism and transport. Additionally, studies on ABCB1 function were performed using Transwell® assays with [ 3 H]-digoxin and [ 3 H]-talinolol as substrates after incubation with the prototypical inducers rifampicin, St John's wort, carbamazepine and efavirenz. The gene and protein expression pattern of drug transporters in Caco-2 cells and jejunal tissue differed considerably. For some transporters culture-time dependent differences in mRNA expression and/or protein abundance could be determined. Finally, none of the studied prototypical inducers showed an effect either on mRNA expression and protein abundance or on the function of ABCB1. Differences in transporter expression in Caco-2 cells compared with jejunal tissue, as well as expression dependence on culture time must be considered in in vitro studies to avoid under- or overestimation of certain transporters. The Caco-2 cell model is not suitable for the evaluation of DDIs caused by transporter induction. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
NASA Astrophysics Data System (ADS)
Sahmani, S.; Aghdam, M. M.
2018-03-01
A wide range of biological applications such as drug delivery, biosensors and hemodialysis can be provided by nanoporous biomaterials due to their uniform pore size as well as considerable pore density. In the current study, the size dependency in the nonlinear primary resonance of micro/nano-beams made of nanoporous biomaterials is anticipated. To accomplish this end, a refined truncated cube is introduced to model the lattice structure of nanoporous biomaterial. Accordingly, analytical expressions for the mechanical properties of material are derived as functions of pore size. After that, based upon a nonlocal strain gradient beam model, the size-dependent nonlinear Duffing type equation of motion is constructed. The Galerkin technique together with the multiple time-scales method is employed to obtain the nonlocal strain gradient frequency-response and amplitude-response related to the nonlinear primary resonance of a micro/nano-beam made of the nanoporous biomaterial with different pore sizes. It is indicated that the nonlocality causes to decrease the response amplitudes associated with the both bifurcation points of the jump phenomenon, while the strain gradient size dependency causes to increase them. Also, it is found that increasing the pore size leads to enhance the nonlinearity, so the maximum deflection of response occurs at higher excitation frequency.
FIBER AND INTEGRATED OPTICS: Excitation of leaky modes in a system of coupled waveguides
NASA Astrophysics Data System (ADS)
Usievich, B. A.; Nurligareev, J. Kh; Sychugov, V. A.; Golant, K. M.
2007-06-01
A system of coupled single-mode waveguides with the number M of guided modes lower than the number N of single-mode waveguides is studied. Leaky modes in this system are investigated in detail. It is shown, in particular, that these modes can be excited by light incident on the side surface of the system when the reflection coefficient vanishes. It is found that the angular dependence of the coefficient of reflection from the side surface of the system can be used to refine the dispersion curve for leaky modes. It is shown that light incident at a grazing angle can propagate in the system in the direction considerably different from the propagation direction of a beam incident from a substrate, even in the case of a small difference in the refractive indices.
Anisotropy of the apparent frequency dependence of backscatter in formalin fixed human myocardium.
Hall, C S; Verdonk, E D; Wickline, S A; Perez, J E; Miller, J G
1997-01-01
Measurements of the frequency dependence of ultrasonic backscatter are presented for specific angles of insonification for regions of infarcted and noninfarcted human myocardium. A 5-MHz transducer was used to insonify cylindrical cores taken from 7 noninfarcted regions and 12 infarcted regions of the left ventricular free wall of 6 formalin-fixed human hearts explanted because of ischemic cardiomyopathy. The dependence of apparent (uncompensated for diffraction effects and attenuation) backscatter on frequency was approximated by a power-law dependence, magnitude of B(f)2 = afn. Under ideal conditions in a lossless medium, the effect of not compensating for the effects of diffraction and attenuation leads to the value of n to be 2.0 for Rayleigh scatterers while the frequency dependence of the fully compensated backscatter coefficient would be f4. The value of n was determined over the frequency range, 3-7 MHz. Both nonifarcted and infarcted myocardium exhibited anisotropy of the frequency dependence of backscatter, with maxima occurring at angles that were perpendicular to the predominant myofiber direction and minima when parallel to the fibers. Perpendicular insonification yielded results for n of 1.8 +/- 0.1 for noninfarcted myocardium and 1.2 +/- 0.1 for infarcted myocardium while parallel insonification yielded results of 0.4 +/- 0.1 for noninfarcted and 0.0 +/- 0.1 for infarcted myocardium. The functional form of the angle-dependent backscatter is similar for both noninfarcted and infarcted myocardium, although the frequency dependence is clearly different for both tissue states for all angles of insonification. The results of this study indicate that the anisotropy of the frequency dependence of backscatter may play a significant role in ultrasonic imaging and is an important consideration for ultrasonic tissue characterization in myocardium.
Calabria, Bianca; Degenhardt, Louisa; Briegleb, Christina; Vos, Theo; Hall, Wayne; Lynskey, Michael; Callaghan, Bridget; Rana, Umer; McLaren, Jennifer
2010-08-01
To review and summarize existing prospective studies reporting on remission from dependence upon amphetamines, cannabis, cocaine or opioids. Systematic searches of the peer-reviewed literature were conducted to identify prospective studies reporting on remission from amphetamines, cannabis, cocaine or opioid dependence. Searches were limited to publication between 1990 and 2009. Reference lists of review articles and important studies were searched to identify additional studies. Remission was defined as no longer meeting diagnostic criteria for drug dependence or abstinence from drug use; follow-up periods of at least three years were investigated. The remission rate was estimated for each drug type, allowing pooling across studies with varying follow-up times. There were few studies examining the course of psychostimulant dependence that met inclusion criteria (one for amphetamines and four for cocaine). There were ten studies of opioid and three for cannabis dependence. Definitions of remission varied and most did not clearly assess remission from dependence. Amphetamine dependence had the highest remission rate (0.4477; 95%CI 0.3991, 0.4945), followed by opioid (0.2235; 95%CI 0.2091, 0.2408) and cocaine dependence (0.1366; 95%CI 0.1244, 0.1498). Conservative estimates of remission rates followed the same pattern with cannabis dependence (0.1734; 95%CI 0.1430, 0.2078) followed by amphetamine (0.1637; 95%CI 0.1475, 0.1797), opioid (0.0917; 95%CI 0.0842, 0.0979) and cocaine dependence (0.0532; 95%CI 0.0502, 0.0597). The limited prospective evidence suggests that "remission" from dependence may occur relatively frequently but rates may differ across drugs. There is very little research on remission from drug dependence; definitions used are often imprecise and inconsistent across studies and there remains considerable uncertainty about the longitudinal course of dependence upon these most commonly used illicit drugs. Copyright 2010 Elsevier Ltd. All rights reserved.
Decomposition of heterogeneous organic matterand its long-term stabilization in soils
Sierra, Carlos A.; Harmon, Mark E.; Perakis, Steven S.
2011-01-01
Soil organic matter is a complex mixture of material with heterogeneous biological, physical, and chemical properties. Decomposition models represent this heterogeneity either as a set of discrete pools with different residence times or as a continuum of qualities. It is unclear though, whether these two different approaches yield comparable predictions of organic matter dynamics. Here, we compare predictions from these two different approaches and propose an intermediate approach to study organic matter decomposition based on concepts from continuous models implemented numerically. We found that the disagreement between discrete and continuous approaches can be considerable depending on the degree of nonlinearity of the model and simulation time. The two approaches can diverge substantially for predicting long-term processes in soils. Based on our alternative approach, which is a modification of the continuous quality theory, we explored the temporal patterns that emerge by treating substrate heterogeneity explicitly. The analysis suggests that the pattern of carbon mineralization over time is highly dependent on the degree and form of nonlinearity in the model, mostly expressed as differences in microbial growth and efficiency for different substrates. Moreover, short-term stabilization and destabilization mechanisms operating simultaneously result in long-term accumulation of carbon characterized by low decomposition rates, independent of the characteristics of the incoming litter. We show that representation of heterogeneity in the decomposition process can lead to substantial improvements in our understanding of carbon mineralization and its long-term stability in soils.
Importance of contraction history on muscle force of porcine urinary bladder smooth muscle.
Menzel, Robin; Böl, Markus; Siebert, Tobias
2017-02-01
The purpose of this study was to provide a comprehensive dataset of porcine urinary bladder smooth muscle properties. Particularly, the history dependence of force production, namely force depression (FD) following shortening and force enhancement (FE) following stretch, was analysed. During active micturition, the circumference of the urinary bladder changes enormously. Thus, FD might be an important phenomenon during smooth muscle contraction. Electrically stimulated, intact urinary bladder strips from pigs (n = 10) were suspended in an aerated-filled organ bath, and different isometric, isotonic, and isokinetic contraction protocols were performed to determine the force-length and the force-velocity relation. FD and FE were assessed in concentric and eccentric contractions with different ramp lengths and ramp velocities. Bladder smooth muscles exhibit considerable amounts of FD and FE. The amount of FD increased significantly with ramp length, while FE did not change. However, FE and FD were independent of ramp velocity. The results imply that smooth muscle bladder strips exhibit similar muscle properties and history-dependent behaviour compared to striated muscles. The provided dataset of muscle properties is important for bladder modelling as well as for the analyses and interpretation of dynamic bladder filling and voiding.
Inland waterway ports nodal attraction indices relevant in development strategies on regional level
NASA Astrophysics Data System (ADS)
Dinu, O.; Burciu, Ş.; Oprea, C.; Ilie, A.; Rosca, M.
2016-08-01
Present paper aims to propose a set of ranking indices and related criteria, concerning mainly spatial analysis, for the inland waterway port, with special view on inland ports of Danube. Commonly, the attraction potential of a certain transport node is assessed by its spatial accessibility indices considering both spatial features of the location provided by the networks that connect into that node and its economic potential defining the level of traffic flows depending on the economic centers of its hinterland. Paper starts with a overview of the critical needs that are required for potential sites to become inland waterway ports and presents nodal functions that coexist at different levels, leading to a port hierarchy from the points of view of: capacity, connection to hinterland, traffic structure and volume. After a brief review of the key inland waterway port ranking criterion, a selection of nodal attraction measures is made. Particular considerations for the Danube inland port case follows proposed methodology concerning indices of performance for network scale and centrality. As expected, the shorter the distance from an inland port to the nearest access point the greater accessibility. Major differences in ranking, dependent on selected criterion, were registered.
Significance of air humidity and air velocity for fungal spore release into the air
NASA Astrophysics Data System (ADS)
Pasanen, A.-L.; Pasanen, P.; Jantunen, M. J.; Kalliokoski, P.
Our previous field studies have shown that the presence of molds in buildings does not necessarily mean elevated airborne spore counts. Therefore, we investigated the release of fungal spores from cultures of Aspergillus fumigatus, Penicillium sp. and Cladosporium sp. at different air velocities and air humidities. Spores of A. fumigatus and Penicillium sp. were released from conidiophores already at air velocity of 0.5 ms -1, whereas Cladosporium spores required at least a velocity of 1.0 ms -1. Airborne spore counts of A. fumigatus and Penicillium sp. were usually higher in dry than moist air, being minimal at relative humidities (r.h.) above 70%, while the effect of r.h. on the release of Cladosporium sp. was ambivalent. The geometric mean diameter of released spores increased when the r.h. exceeded a certain level which depends on fungal genus. Thus, spores of all three fungi were hygroscopic but the hygroscopicity of various spores appeared at different r.h.-ranges. This study indicates that spore release is controlled by external factors and depends on fungal genus which can be one reason for considerable variation of airborne spore counts in buildings with mold problems.
Analytic Thermoelectric Couple Modeling: Variable Material Properties and Transient Operation
NASA Technical Reports Server (NTRS)
Mackey, Jonathan A.; Sehirlioglu, Alp; Dynys, Fred
2015-01-01
To gain a deeper understanding of the operation of a thermoelectric couple a set of analytic solutions have been derived for a variable material property couple and a transient couple. Using an analytic approach, as opposed to commonly used numerical techniques, results in a set of useful design guidelines. These guidelines can serve as useful starting conditions for further numerical studies, or can serve as design rules for lab built couples. The analytic modeling considers two cases and accounts for 1) material properties which vary with temperature and 2) transient operation of a couple. The variable material property case was handled by means of an asymptotic expansion, which allows for insight into the influence of temperature dependence on different material properties. The variable property work demonstrated the important fact that materials with identical average Figure of Merits can lead to different conversion efficiencies due to temperature dependence of the properties. The transient couple was investigated through a Greens function approach; several transient boundary conditions were investigated. The transient work introduces several new design considerations which are not captured by the classic steady state analysis. The work helps to assist in designing couples for optimal performance, and also helps assist in material selection.
Floros, Stelios; Liakopoulou-Kyriakides, Maria; Karatasos, Kostas
2017-01-01
The use of microwaves in every day’s applications raises issues regarding the non thermal biological effects of microwaves. In this work we employ molecular dynamics simulations to advance further the dielectric studies of protein solutions in the case of lysozyme, taking into consideration possible frequency dependent changes in the structural and dynamic properties of the system upon application of electric field in the microwave region. The obtained dielectric spectra are identical with those derived in our previous work using the Fröhlich-Kirkwood approach in the framework of the linear response theory. Noticeable structural changes in the protein have been observed only at frequencies near its absorption maximum. Concerning Cα position fluctuations, different frequencies affected different regions of the protein sequence. Furthermore, the influence of the field on the kinetics of protein-water as well as on the water-water hydrogen bonds in the first hydration shell has been studied; an extension of the Luzar-Chandler kinetic model was deemed necessary for a better fit of the applied field results and for the estimation of more accurate hydrogen bond lifetime values. PMID:28129348
Neural correlates of affective influence on choice.
Piech, Richard M; Lewis, Jade; Parkinson, Caroline H; Owen, Adrian M; Roberts, Angela C; Downing, Paul E; Parkinson, John A
2010-03-01
Making the right choice depends crucially on the accurate valuation of the available options in the light of current needs and goals of an individual. Thus, the valuation of identical options can vary considerably with motivational context. The present study investigated the neural structures underlying context dependent evaluation. We instructed participants to choose from food menu items based on different criteria: on their anticipated taste or on ease of preparation. The aim of the manipulation was to assess which neural sites were activated during choice guided by incentive value, and which during choice based on a value-irrelevant criterion. To assess the impact of increased motivation, affect-guided choice and cognition-guided choice was compared during the sated and hungry states. During affective choice, we identified increased activity in structures representing primarily valuation and taste (medial prefrontal cortex, insula). During cognitive choice, structures showing increased activity included those implicated in suppression and conflict monitoring (lateral orbitofrontal cortex, anterior cingulate). Hunger influenced choice-related activity in the ventrolateral prefrontal cortex. Our results show that choice is associated with the use of distinct neural structures for the pursuit of different goals. Published by Elsevier Inc.
New Evidence on Employment Effects of Informal Care Provision in Europe.
Kolodziej, Ingo W K; Reichert, Arndt R; Schmitz, Hendrik
2018-02-22
To estimate how labor force participation is affected when adult children provide informal care to their parents. Survey of Health, Ageing and Retirement in Europe from 2004 to 2013. To offset the problem of endogeneity, we exploit the availability of other potential caregivers within the family as predictors of the probability to provide care for a dependent parent. Contrary to most previous studies, the dataset covers the whole working-age population in the majority of European countries. Individuals explicitly had to opt for or against the provision of care to their care-dependent parents, which allows us to more precisely estimate the effect of caregiving on labor force participation. Results reveal a negative causal effect that indicates that informal care provision reduces labor force participation by 14.0 percentage points (95 percent CI: -0.307, 0.026). Point estimates suggest that the effect is larger for men; however, this gender difference is not significantly different from zero at conventional levels. Results apply to individuals whose consideration in long-term care policy is highly relevant, that is, children whose willingness to provide informal care to their parents is altered by available alternatives of family caregivers. © Health Research and Educational Trust.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zhao, G. Q.; Feng, H. Q.; Liu, Q.
Energetic electrons with power-law spectra are commonly observed in astrophysics. This paper investigates electron cyclotron maser emission (ECME) from the power-law electrons, in which strong pitch-angle anisotropy is emphasized. The electron distribution function proposed in this paper can describe various types of pitch-angle anisotropy. Results show that the emission properties of ECME, including radiation growth, propagation, and frequency properties, depend considerably on the types of electron pitch-angle anisotropy, and different wave modes show different dependences on the pitch angle of electrons. In particular, the maximum growth rate of the X2 mode rapidly decreases with respect to the electron pitch-angle cosinemore » μ {sub 0} at which the electron distribution peaks, while the growth rates for other modes (X1, O1, O2) initially increase before decreasing as μ {sub 0} increases. Moreover, the O mode, as well as the X mode, can be the fastest growth mode, in terms of not only the plasma parameter but also the type of electron pitch-angle distribution. This result presents a significant extension of the recent researches on ECME driven by the lower energy cutoff of power-law electrons, in which the X mode is generally the fastest growth mode.« less
Are the gyro-ages of field stars underestimated?
NASA Astrophysics Data System (ADS)
Kovács, Géza
2015-09-01
By using the current photometric rotational data on eight galactic open clusters, we show that the evolutionary stellar model (isochrone) ages of these clusters are tightly correlated with the period shifts applied to the (B - V)0-Prot ridges that optimally align these ridges to the one defined by Praesepe and the Hyades. On the other hand, when the traditional Skumanich-type multiplicative transformation is used, the ridges become far less aligned due to the age-dependent slope change introduced by the period multiplication. Therefore, we employ our simple additive gyro-age calibration on various datasets of Galactic field stars to test its applicability. We show that, in the overall sense, the gyro-ages are systematically greater than the isochrone ages. The difference could exceed several giga years, depending on the stellar parameters. Although the age overlap between the open clusters used in the calibration and the field star samples is only partial, the systematic difference indicates the limitation of the currently available gyro-age methods and suggests that the rotation of field stars slows down with a considerably lower speed than we would expect from the simple extrapolation of the stellar rotation rates in open clusters.
A Statistical Comparison of Coupled Thermosphere-Ionosphere Models
NASA Astrophysics Data System (ADS)
Liuzzo, L. R.
2014-12-01
The thermosphere-ionosphere system is a highly dynamic, non-linearly coupled interaction that fluctuates on a daily basis. Many models exist to attempt to quantify the relationship between the two atmospheric layers, and each approaches the problem differently. Because these models differ in the implementation of the equations that govern the dynamics of the thermosphere-ionosphere system, it is important to understand under which conditions each model performs best, and under which conditions each model may have limitations in accuracy. With this in consideration, this study examines the ability of two of the leading coupled thermosphere-ionosphere models in the community, TIE-GCM and GITM, to reproduce thermospheric and ionospheric quantities observed by the CHAMP satellite during times of differing geomagnetic activity. Neutral and electron densities are studied for three geomagnetic activity levels, ranging form high to minimal activity. Metrics used to quantify differences between the two models include root-mean-square error and prediction efficiency, and qualitative differences between a model and observed data is also considered. The metrics are separated into the high- mid- and low-latitude region to depict any latitudinal dependencies of the models during the various events. Despite solving for the same parameters, the models are shown to be highly dependent on the amount of activity level that occurs and can be significantly different from each other. In addition, in comparing previous statistical studies that use the models, a clear improvement is observed in the evolution of each model as thermospheric and ionosphericconstituents during the differing levels of activity are solved.
A quasi-hyperbolic discounting approach to smoking behavior
2014-01-01
Addiction has attracted considerable attention in health and behavioral economics, and economists have attempted to understand addiction from the viewpoint of decision making over time. This paper investigates whether two time preference parameters can successfully predict smoking status, including cigarette dependence. Both the present bias and the constant time preference parameters account for smoking behavior status and cigarette dependence. PMID:25006542
ERIC Educational Resources Information Center
Tanner-Smith, Emily E.; Tipton, Elizabeth
2014-01-01
Methodologists have recently proposed robust variance estimation as one way to handle dependent effect sizes in meta-analysis. Software macros for robust variance estimation in meta-analysis are currently available for Stata (StataCorp LP, College Station, TX, USA) and SPSS (IBM, Armonk, NY, USA), yet there is little guidance for authors regarding…
ERIC Educational Resources Information Center
Nardi, Elena; Biza, Irene; Zachariades, Theodossios
2012-01-01
In this paper, we propose an approach to analysing teacher arguments that takes into account field dependence--namely, in Toulmin's sense, the dependence of warrants deployed in an argument on the field of activity to which the argument relates. Freeman, to circumvent issues that emerge when we attempt to determine the field(s) that an argument…
Li, Jun; Nekka, Fahima
2013-02-21
The determination of an optimal dosing regimen is a critical step to enhance the drug efficacy and avoid toxicity. Rational dosing recommendations based on mathematical considerations are increasingly being adopted in the process of drug development and use. In this paper, we propose a quantitative approach to evaluate the efficacy of antibiotic agents. By integrating both pharmacokinetic (PK) and pharmacodynamic (PD) information, this approach gives rise to a unified formalism able to measure the cause-effect of dosing regimens. This new pharmaco-metric allows to cover a whole range of antibiotics, including the two well known concentration and time dependent classes, through the introduction of the Hill-dependency concept. As a direct fallout, our formalism opens a new path toward the bioequivalence evaluation in terms of PK and PD, which associates the in vivo drug concentration and the in vitro drug effect. Using this new approach, we succeeded to reveal unexpected, but relevant behaviors of drug performance when different drug regimens and drug classes are considered. Of particular notice, we found that the doses required to reach the same therapeutic effect, when scheduled differently, exhibit completely different tendencies for concentration and time dependent drugs. Moreover, we theoretically confirmed the previous experimental results of the superiority of the once daily regimen of aminoglycosides. The proposed methodology is appealing for its computational features and can easily be applicable to design fair clinical protocols or rationalize prescription decisions. Copyright © 2012 Elsevier Ltd. All rights reserved.
Sex-dependent effects of cannabis-induced analgesia.
Cooper, Ziva D; Haney, Margaret
2016-10-01
Preclinical studies demonstrate that cannabinoid-mediated antinociceptive effects vary according to sex; it is unknown if these findings extend to humans. This retrospective analysis compared the analgesic, subjective and physiological effects of active cannabis (3.56-5.60% THC) and inactive cannabis (0.00% THC) in male (N=21) and female (N=21) cannabis smokers under double-blind, placebo-controlled conditions. Pain response was measured using the Cold-Pressor Test (CPT). Participants immersed their hand in cold water (4°C); times to report pain (pain sensitivity) and withdraw the hand (pain tolerance) were recorded. Subjective drug ratings were also measured. Among men, active cannabis significantly decreased pain sensitivity relative to inactive cannabis (p<0.01). In women, active cannabis failed to decrease pain sensitivity relative to inactive. Active cannabis increased pain tolerance in both men women immediately after smoking (p<0.001); a trend was observed for differences between men and women (p<0.10). Active cannabis also increased subjective ratings of cannabis associated with abuse liability ('Take again,' 'Liking,' 'Good drug effect'), drug strength, and 'High' relative to inactive in both men and women (p<0.01). These results indicate that in cannabis smokers, men exhibit greater cannabis-induced analgesia relative to women. These sex-dependent differences are independent of cannabis-elicited subjective effects associated with abuse-liability, which were consistent between men and women. As such, sex-dependent differences in cannabis's analgesic effects are an important consideration that warrants further investigation when considering the potential therapeutic effects of cannabinoids for pain relief. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Sex-Dependent Effects Of Cannabis-Induced Analgesia
Cooper, Ziva D.; Haney, Margaret
2016-01-01
Background Preclinical studies demonstrate that cannabinoid-mediated antinociceptive effects vary according to sex; it is unknown if these findings extend to humans. Methods This retrospective analysis compared the analgesic, subjective and physiological effects of active cannabis (3.56 - 5.60% THC) and inactive cannabis (0.00% THC) in male (N = 21) and female (N = 21) cannabis smokers under double-blind, placebo-controlled conditions. Pain response was measured using the Cold-Pressor Test (CPT). Participants immersed their hand in cold water (4°C); times to report pain (pain sensitivity) and withdraw the hand (pain tolerance) were recorded. Subjective drug ratings were also measured. Results Among men, active cannabis significantly decreased pain sensitivity relative to inactive cannabis (p < 0.01). In women, active cannabis failed to decrease pain sensitivity relative to inactive. Active cannabis increased pain tolerance in both men women immediately after smoking (p < 0.001); a trend was observed for differences between men and women (p < 0.10). Active cannabis also increased subjective ratings of cannabis associated with abuse liability (‘Take again,’ ‘Liking,’ ‘Good drug effect’), drug strength, and ‘High’ relative to inactive in both men and women (p < 0.01). Conclusions These results indicate that in cannabis smokers, men exhibit greater cannabis-induced analgesia relative to women. These sex-dependent differences are independent of cannabis-elicited subjective effects associated with abuse-liability, which were consistent between men and women. As such, sex-dependent differences in cannabis's analgesic effects are an important consideration that warrants further investigation when considering the potential therapeutic effects of cannabinoids for pain relief. PMID:27522535
The growth transformation of human B cells involves superinduction of hsp70 and hsp90.
Cheung, R K; Dosch, H M
1993-04-01
Epstein-Barr virus (EBV) is a latent human herpes virus associated with a range of malignant and non-malignant disorders. EBV binds to CD21 virus receptors on B lymphocytes and growth transforms these cells; in susceptible (e.g., immunodeficient) hosts such cells rapidly expand into fatal lymphomas. Virus binding and infection trigger a cascade of cellular events which are transformation prerequisite and analogous to non-oncogenic cell activation events but which differ in several quantitative or qualitative respects. Unique trans-membrane Ca2+ currents, Na+/H+ exchange, as well as tyrosine phosphorylation and p56lck-gene induction suggest that even early on the transformation process has oncogenic specificity. In this report we describe that two additional cellular gene families, the stress proteins hsp70 and hsp90, are coordinately induced at mRNA and protein levels and, quite different from hsp induction by thermal stress, this induction is dependent on EBV-induced trans-membrane Ca2+ currents. Blockade of hsp induction prevents transformation. The kinetics and induction prerequisites set this response well apart from reported responses to thermal or viral stress protein induction. Like p56lck-, hsp induction is purely a post-receptor binding event and not dependent on expression of any viral gene. The induction kinetics, with a peak at approximately 12-16 hr and subsequent decline to control levels, considerably extend the chronological map of elements in the CD21-dependent branch of the transformation pathway and suggest a specific role of induced hsp different from the cell cycle-related functions observed in other cell systems.
Key considerations in designing a speech brain-computer interface.
Bocquelet, Florent; Hueber, Thomas; Girin, Laurent; Chabardès, Stéphan; Yvert, Blaise
2016-11-01
Restoring communication in case of aphasia is a key challenge for neurotechnologies. To this end, brain-computer strategies can be envisioned to allow artificial speech synthesis from the continuous decoding of neural signals underlying speech imagination. Such speech brain-computer interfaces do not exist yet and their design should consider three key choices that need to be made: the choice of appropriate brain regions to record neural activity from, the choice of an appropriate recording technique, and the choice of a neural decoding scheme in association with an appropriate speech synthesis method. These key considerations are discussed here in light of (1) the current understanding of the functional neuroanatomy of cortical areas underlying overt and covert speech production, (2) the available literature making use of a variety of brain recording techniques to better characterize and address the challenge of decoding cortical speech signals, and (3) the different speech synthesis approaches that can be considered depending on the level of speech representation (phonetic, acoustic or articulatory) envisioned to be decoded at the core of a speech BCI paradigm. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Fried, P A; Watkinson, B
2000-01-01
Visuoperceptual performance was examined in 146 9- to 12-year old children for whom prenatal exposure to marihuana and cigarettes had been ascertained. The subjects, participants in an ongoing longitudinal study, were from a low-risk, predominantly middle class sample. The tasks ranged in complexity from those that required basic visuoperceptual skills to those that required considerable integration and cognitive manipulation of such skills. Trend analysis revealed a dose dependent negative association between prenatal cigarette exposure and an overall score reflecting basic visuoperceptual functioning. This association remained after consideration of potential prenatal confounds, pre- and postnatal secondhand smoke exposure, and the nonperceptual demands of the tasks. This poorer performance in the basic visuoperceptual domain underlay a poorer performance in more complex visuoperceptual tasks among the offspring of cigarette smokers. In contrast, prenatal marihuana exposure was not associated with basic visuoperceptual functioning but was negatively associated with performance in visual problem solving situations. The interpretation of the marihuana findings is discussed in relation to a "top-down" integrative ability associated with executive function, the extant prefrontal literature, and earlier observations of this sample.
Barr, Dana B.; Wang, Richard Y.; Needham, Larry L.
2005-01-01
Biomonitoring of exposure is a useful tool for assessing environmental exposures. The matrices available for analyses include blood, urine, breast milk, adipose tissue, and saliva, among others. The sampling can be staged to represent the particular time period of concern: preconceptionally from both parents, from a pregnant woman during each of the three trimesters, during and immediately after childbirth, from the mother postnatally, and from the child as it develops to 21 years of age. The appropriate sample for biomonitoring will depend upon matrix availability, the time period of concern for a particular exposure or health effect, and the different classes of environmental chemicals to be monitored. This article describes the matrices available for biomonitoring during the life stages being evaluated in the National Children’s Study; the best biologic matrices for exposure assessment for each individual chemical class, including consideration of alternative matrices; the analytical methods used for analysis, including quality control procedures and less costly alternatives; the costs of analysis; optimal storage conditions; and chemical and matrix stability during long-term storage. PMID:16079083
Method of operator safety assessment for underground mobile mining equipment
NASA Astrophysics Data System (ADS)
Działak, Paulina; Karliński, Jacek; Rusiński, Eugeniusz
2018-01-01
The paper presents a method of assessing the safety of operators of mobile mining equipment (MME), which is adapted to current and future geological and mining conditions. The authors focused on underground mines, with special consideration of copper mines (KGHM). As extraction reaches into deeper layers of the deposit it can activate natural hazards, which, thus far, have been considered unusual and whose range and intensity are different depending on the field of operation. One of the main hazards that affect work safety and can become the main barrier in the exploitation of deposits at greater depths is climate threat. The authors have analysed the phenomena which may impact the safety of MME operators, with consideration of accidents that have not yet been studied and are not covered by the current safety standards for this group of miners. An attempt was made to develop a method for assessing the safety of MME operators, which takes into account the mentioned natural hazards and which is adapted to current and future environmental conditions in underground mines.
Migration and psychological status of adolescents in Turkey.
Aksel, Seyda; Gün, Zübeyit; Irmak, Türkan Yilmaz; Cengelci, Banu
2007-01-01
The aim of this study was to investigate the influence of involuntary migration on an adolescent population that had moved with their families to either one of two culturally different locations in Turkey. One of these groups had moved from a village in Eastern Turkey to a nearby town, while the other had moved a considerable distance to a large city in Western Turkey. Comparison groups included adolescents from both regions who had never migrated. Measures of self-esteem, satisfaction with life, and social support networks were used with 305 adolescents who were between the ages of 12 and 15. Adolescents who had migrated scored lower on self-esteem and life satisfaction, and had fewer people in their social support networks than those who had not. It was also found that those who had migrated tended to be more dependent on peers than family for social support. This was probably the case because school attendance was lower for migrants, particularly for males, and the probability of full time work on the street away from their families was considerably higher.
von See, Constantin; Stoetzer, Marcus; Ruecker, Martin; Wagner, Max; Schumann, Paul; Gellrich, Nils-Claudius
2014-01-01
The placement of self-tapping implants is associated with microfractures and the formation of bone chips along the cutting flutes. This study was conducted to investigate the effect of different cutting edge angles on chip formation during the machining of trabecular and cortical bone using instruments with a rough titanium surface. Mandibular cortical and trabecular bone specimens were obtained from freshly slaughtered domestic pigs. A predefined thrust force was applied to the specimens. Four specially designed cutting instruments that simulated dental implants and had a rough titanium surface were allowed to complete one full revolution at cutting edge angles of 55, 65, 75, and 85 degrees, respectively. Torque and thrust were measured during the cutting process. Bone chips were measured and weighed under a microscope. Different cutting edge angles did not lead to significant differences in torque. The lowest torque values were measured when the cutting edges were positioned at 65 degrees in trabecular bone and at 85 degrees in cortical bone. Bone chips were significantly larger and heavier at angles of 55 and 65 degrees than at angles of 75 and 85 degrees in trabecular bone. Instruments with a rough titanium surface show considerable angle-dependent differences in chip formation. In addition to bone density, the angle of the cutting edges should be taken into consideration during the placement of dental implants. Good results were obtained when the cutting edges were positioned at an angle of 65 degrees. This angle can have positive effects on osseointegration.
NASA Astrophysics Data System (ADS)
Nezlobin, David; Pariente, Sarah; Lavee, Hanoch; Sachs, Eyal; Levenberg, Eyal
2017-04-01
The processes of runoff initiation on smooth impervious surfaces and various asphalt pavements are investigated in laboratory rain simulator experiments and outdoor sprinkling tests. Visual and FLIR observations indicate that runoff initiation is associated with coalescence of drop clusters on the surface and complex changes in micro-connectivity. Depending on surface inclination, several morphological regimes of flow initiation have been observed. In the case of very small inclination the runoff initiation is governed by critical merging of drop clusters on the surface and develops in broad flows (very abrupt, but delayed). For larger inclinations, the runoff occurs in rivulets or strongly directed flow threads. On asphalt pavements the runoff initiation is also strongly affected by pavement SVF (Surface Void Fraction), texture and even by the asphalt hydrophobicity. A simplified bi-level model of the pavement surface may explain principal differences in the runoff initiation on asphalts with small, intermediate and large SVF values. For small SVF (standard fresh asphalts) the runoff develops on the upper surface level, and filling of the surface voids is not always required (especially for the large inclinations). For intermediate SVF (considerably deteriorated asphalts) the runoff develops as well on the upper surface level, but only after considerable filling of the surface voids. Finally, on severely deteriorated asphalts (very large SVFs) the runoff develops on the "bottom" level of asphalt surface, after only partial filling of the surface voids. Other factors, such as drops splash and splitting, also affect the process of runoff initiation and explain rather considerable differences (sometimes of 2-3 mm rain depth) in the runoff thresholds on various non-porous asphalt pavements. Similar phenomena can be probably observed on certain types of rock outcrops.
Huang, Jr-Chuan; Lee, Tsung-Yu; Teng, Tse-Yang; Chen, Yi-Chin; Huang, Cho-Ying; Lee, Cheing-Tung
2014-01-01
The exponent decay in landslide frequency-area distribution is widely used for assessing the consequences of landslides and with some studies arguing that the slope of the exponent decay is universal and independent of mechanisms and environmental settings. However, the documented exponent slopes are diverse and hence data processing is hypothesized for this inconsistency. An elaborated statistical experiment and two actual landslide inventories were used here to demonstrate the influences of the data processing on the determination of the exponent. Seven categories with different landslide numbers were generated from the predefined inverse-gamma distribution and then analyzed by three data processing procedures (logarithmic binning, LB, normalized logarithmic binning, NLB and cumulative distribution function, CDF). Five different bin widths were also considered while applying LB and NLB. Following that, the maximum likelihood estimation was used to estimate the exponent slopes. The results showed that the exponents estimated by CDF were unbiased while LB and NLB performed poorly. Two binning-based methods led to considerable biases that increased with the increase of landslide number and bin width. The standard deviations of the estimated exponents were dependent not just on the landslide number but also on binning method and bin width. Both extremely few and plentiful landslide numbers reduced the confidence of the estimated exponents, which could be attributed to limited landslide numbers and considerable operational bias, respectively. The diverse documented exponents in literature should therefore be adjusted accordingly. Our study strongly suggests that the considerable bias due to data processing and the data quality should be constrained in order to advance the understanding of landslide processes. PMID:24852019
Positioning Vascularized Composite Allotransplantation in the Spectrum of Transplantation
2017-10-01
have now shown that the efficacy of both protocols is dependent upon a radiation-sensitive donor bone marrow (BM) cell type that is of T or B cell... dependent VCA survival. IL-2C Therapy Increases the Number but Not Function of Foxp3 CD4+ Treg Cells To test the effects of JES6-1 mAb-based IL-2C...which Treg cell- dependent immunoregulation has considerable potential. These IL-2C studies are now “in press” (4). TASK 5: OPTIMAL COMBINATION
Economic dependency and divorce: implications for the private sphere.
Clark, R
1990-01-01
"This paper asserts a connection between economic dependency and divorce. It argues that, because dependency deprives women of equal access to the public sphere and because it confines them, through normative definition, to the private sphere, it reduces their likelihood of seeking divorce. The paper also argues, contrary to recent findings, that socioeconomic development should be linearly and positively associated with divorce. Data from 51 nations are examined and multiple regression analysis [suggests] considerable support for these arguments." excerpt
2008-01-01
oriented grain-boundaries. In this work we show considerable evidence for such weak-coupling by study of the dependence of magnetization in bulk and...powdered samples. Bulk sample magnetization curves show very little hysteresis while remanent magnetization shows almost no sample size dependence...K Fig. 2 (Color online) Magnetization hysteresis loops at 5 and 20 K for the bulk LaO0.89F0.11FeAs. Inset shows the temperature dependence of
Blanco, Carlos; García-Anaya, María; Wall, Melanie; de Los Cobos, José Carlos Pérez; Swierad, Ewelina; Wang, Shuai; Petry, Nancy M
2015-05-01
Pathological gambling (PG) is now aligned with substance use disorders in the DSM-5 as the first officially recognized behavioral addiction. There is growing interest in examining obesity as an addictive disorder as well. The goal of this study was to investigate whether epidemiological data provide support for the consideration of PG and obesity as addictive disorders. Factor analysis of data from a large, nationally representative sample of US adults (N=43,093), using nicotine dependence, alcohol dependence, drug dependence, PG and obesity as indicators. It was hypothesized that nicotine dependence, alcohol dependence and drug use dependence would load on a single factor. It was further hypothesized that if PG and obesity were addictive disorders, they would load on the same factor as substance use disorders, whereas failure to load on the addictive factor would not support their conceptualization as addictive disorders. A model with one factor including nicotine dependence, alcohol dependence, drug dependence and PG, but not obesity, provided a very good fit to the data, as indicated by CFI=0.99, TLI=0.99 and RMSEA=0.01 and loadings of all indicators >0.4. Data from this study support the inclusion of PG in a latent factor with substance use disorders but do not lend support to the consideration of obesity, as defined by BMI, as an addictive disorder. Future research should investigate whether certain subtypes of obesity are best conceptualized as addictive disorders and the shared biological and environmental factors that account for the common and specific features of addictive disorders. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Naper, Sille Ohrem
2009-11-01
To investigate the mortality among social assistance recipients, who are among the most marginalized people in Norway. Cause-specific mortality was analysed in an attempt to explain the excess mortality. Previous research has suggested that social disadvantage leads to higher mortality from all causes, whereas others have found substantial variation when studying separate causes. The impact of the various causes will influence policy recommendations. Data were compiled through linking between Norwegian administrative records. The entire population born between 1935 and 1974 (2,297,621 people) was followed with respect to social assistance and death from 1993 to 2003. Cause-specific, age-standardized mortality rates for social assistance recipients and the rest of the population were calculated, and both the absolute (rate difference) and relative (rate ratio) rates were measured. The rate ratio for total mortality was 3.1 for men and 2.5 for women for the comparison between social assistance recipients and the general population. The mortality among social assistance recipients was higher for all causes, but the magnitude differed considerably, depending on the cause. The rate ratio for men ranged from 1.2 for non-smoking-related cancer to 18.8 for alcohol- and drug-related causes. Alcohol-and drug-related and violent causes together contributed to half of the excess mortality for men and one-third for women. The mortality of this socially disadvantaged group was considerably higher than that of the general population, and this difference reflected mainly drug-related causes.
Social Media Analyses for Social Measurement.
Schober, Michael F; Pasek, Josh; Guggenheim, Lauren; Lampe, Cliff; Conrad, Frederick G
2016-01-01
Demonstrations that analyses of social media content can align with measurement from sample surveys have raised the question of whether survey research can be supplemented or even replaced with less costly and burdensome data mining of already-existing or "found" social media content. But just how trustworthy such measurement can be-say, to replace official statistics-is unknown. Survey researchers and data scientists approach key questions from starting assumptions and analytic traditions that differ on, for example, the need for representative samples drawn from frames that fully cover the population. New conversations between these scholarly communities are needed to understand the potential points of alignment and non-alignment. Across these approaches, there are major differences in (a) how participants (survey respondents and social media posters) understand the activity they are engaged in; (b) the nature of the data produced by survey responses and social media posts, and the inferences that are legitimate given the data; and (c) practical and ethical considerations surrounding the use of the data. Estimates are likely to align to differing degrees depending on the research topic and the populations under consideration, the particular features of the surveys and social media sites involved, and the analytic techniques for extracting opinions and experiences from social media. Traditional population coverage may not be required for social media content to effectively predict social phenomena to the extent that social media content distills or summarizes broader conversations that are also measured by surveys.
Social Media Analyses for Social Measurement
Schober, Michael F.; Pasek, Josh; Guggenheim, Lauren; Lampe, Cliff; Conrad, Frederick G.
2016-01-01
Demonstrations that analyses of social media content can align with measurement from sample surveys have raised the question of whether survey research can be supplemented or even replaced with less costly and burdensome data mining of already-existing or “found” social media content. But just how trustworthy such measurement can be—say, to replace official statistics—is unknown. Survey researchers and data scientists approach key questions from starting assumptions and analytic traditions that differ on, for example, the need for representative samples drawn from frames that fully cover the population. New conversations between these scholarly communities are needed to understand the potential points of alignment and non-alignment. Across these approaches, there are major differences in (a) how participants (survey respondents and social media posters) understand the activity they are engaged in; (b) the nature of the data produced by survey responses and social media posts, and the inferences that are legitimate given the data; and (c) practical and ethical considerations surrounding the use of the data. Estimates are likely to align to differing degrees depending on the research topic and the populations under consideration, the particular features of the surveys and social media sites involved, and the analytic techniques for extracting opinions and experiences from social media. Traditional population coverage may not be required for social media content to effectively predict social phenomena to the extent that social media content distills or summarizes broader conversations that are also measured by surveys. PMID:27257310
Revisiting the quantum Szilard engine with fully quantum considerations
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Hai; School of Information and Electronics Engineering, Shandong Institute of Business and Technology, Yantai 264000; Zou, Jian, E-mail: zoujian@bit.edu.cn
2012-12-15
By considering level shifting during the insertion process we revisit the quantum Szilard engine (QSZE) with fully quantum consideration. We derive the general expressions of the heat absorbed from thermal bath and the total work done to the environment by the system in a cycle with two different cyclic strategies. We find that only the quantum information contributes to the absorbed heat, and the classical information acts like a feedback controller and has no direct effect on the absorbed heat. This is the first demonstration of the different effects of quantum information and classical information for extracting heat from themore » bath in the QSZE. Moreover, when the well width L{yields}{infinity} or the temperature of the bath T{yields}{infinity} the QSZE reduces to the classical Szilard engine (CSZE), and the total work satisfies the relation W{sub tot}=k{sub B}Tln2 as obtained by Sang Wook Kim et al. [S.W. Kim, T. Sagawa, S. De Liberato, M. Ueda, Phys. Rev. Lett. 106 (2011) 070401] for one particle case. - Highlights: Black-Right-Pointing-Pointer For the first time analyze the QSZE by considering energy level shifts. Black-Right-Pointing-Pointer Find different roles played by classical and quantum information in the QSZE. Black-Right-Pointing-Pointer The amount of work extracted depends on the cyclic strategies of the QSZE. Black-Right-Pointing-Pointer Verify that the QSZE will reduce to the CSZE in the classical limits.« less
[Sports accidents: 1963-1973 statistics].
Fasler, S
1976-01-01
Every year, the Swiss Accident Insurance Administration is paying a considerable amount of money for sports accidents. From 1963 to 1973 the number of these accidents has increased more markedly than other types of accidents. Different tendencies can be observed in the different types of sports: skiing accidents have, after a long period of retrogression until 1973, shown a noticeable augmentation again. Football accidents and accidents in other types of sports have on the other hand increased year by year. Mountaineering and aquatic sports often result in fatal accidents. The numerous preventive measures in skiing accidents have obviously been successful. Not only the fractures have decreased, but also the average number of days where sickness benefit was paid. Next to the traffic accidents, the skiing accidents are the most expensive ones. The nature of the healing cost in sports accidents has changed during the period from 1967 to 1972, depending on the different types of sports. In particular, hospital costs have changed considerably. The number of medical consultations per accident has decreased. Payment of sickness benefit has followed the development of the salaries on the one hand and the modifications of the number of lost days on the other. Finally, the costs of the annuities show more or less the same tendency as the ones for sickness benefit. A very gross estimation on the economical losses through sports accidents in Switzerland makes us believe that the direct and indirect costs actually amount to more than one thousand millions of Swiss Francs per year.
Mahajan, Rajeev; Solanki, Jitender; Kurdekar, Raghvendra S; Gupta, Sarika; Modh, Ashish; Yadav, OmPrakash
2017-05-01
Tobacco use is considered to be global pandemic. The study was done to assess the effectiveness of smoking cessation intervention among workers by motivational interviewing among handicraft factories, Jodhpur, Rajasthan. An interventional study was carried out among 400 handicraft factory workers on the basis of inclusion and exclusion criterion. Twenty one handicraft factories were taken into consideration. Training, Standardization and Calibration of Examiners was carried out in the public health department. The structured pre-tested proforma and Fagerstrom questionnaire was used to record the data. Four sessions of intervention were given to workers. Follow ups were carried out after 1 month, 3month and 6month. Paired t-test was used to compare Fagerstrom/smoking analysis mean scores among study and control groups before and after intervention. showed that in study group, a percentage change of +1.2%, seen in high dependence category and -1.5 in very high dependence and after 6 months the change was+14.2%, 18.7%, -19.2% in Very low dependence, Low dependence, Medium dependence, -11.8% was seen in high dependence category and -1.8 in very high dependence. When comparison was done among Fagerstrom/smoking analysis mean scores among study subjects before and after intervention. It was found that there was a significant difference between the mean scores of Fagerstrom/smoking analysis between baseline - 3 months, 3 months to 6 months and 6 months to 9 months among study group as compared to control group. Tobacco addiction produces neurological and behavioural change, optima; approach involving behavioural change and pharmacotherapy are needed.
Variability in Dopamine Genes Dissociates Model-Based and Model-Free Reinforcement Learning
Bath, Kevin G.; Daw, Nathaniel D.; Frank, Michael J.
2016-01-01
Considerable evidence suggests that multiple learning systems can drive behavior. Choice can proceed reflexively from previous actions and their associated outcomes, as captured by “model-free” learning algorithms, or flexibly from prospective consideration of outcomes that might occur, as captured by “model-based” learning algorithms. However, differential contributions of dopamine to these systems are poorly understood. Dopamine is widely thought to support model-free learning by modulating plasticity in striatum. Model-based learning may also be affected by these striatal effects, or by other dopaminergic effects elsewhere, notably on prefrontal working memory function. Indeed, prominent demonstrations linking striatal dopamine to putatively model-free learning did not rule out model-based effects, whereas other studies have reported dopaminergic modulation of verifiably model-based learning, but without distinguishing a prefrontal versus striatal locus. To clarify the relationships between dopamine, neural systems, and learning strategies, we combine a genetic association approach in humans with two well-studied reinforcement learning tasks: one isolating model-based from model-free behavior and the other sensitive to key aspects of striatal plasticity. Prefrontal function was indexed by a polymorphism in the COMT gene, differences of which reflect dopamine levels in the prefrontal cortex. This polymorphism has been associated with differences in prefrontal activity and working memory. Striatal function was indexed by a gene coding for DARPP-32, which is densely expressed in the striatum where it is necessary for synaptic plasticity. We found evidence for our hypothesis that variations in prefrontal dopamine relate to model-based learning, whereas variations in striatal dopamine function relate to model-free learning. SIGNIFICANCE STATEMENT Decisions can stem reflexively from their previously associated outcomes or flexibly from deliberative consideration of potential choice outcomes. Research implicates a dopamine-dependent striatal learning mechanism in the former type of choice. Although recent work has indicated that dopamine is also involved in flexible, goal-directed decision-making, it remains unclear whether it also contributes via striatum or via the dopamine-dependent working memory function of prefrontal cortex. We examined genetic indices of dopamine function in these regions and their relation to the two choice strategies. We found that striatal dopamine function related most clearly to the reflexive strategy, as previously shown, and that prefrontal dopamine related most clearly to the flexible strategy. These findings suggest that dissociable brain regions support dissociable choice strategies. PMID:26818509
Combinatorial Interdependence in Lottery
ERIC Educational Resources Information Center
Helman, Danny
2005-01-01
This paper examines a real life question of gamble facing lottery players. Combinatorial dependence plays a central role in shaping the game probabilistic structure, but might not carry the merited weight in punters' considerations.
Patterns of alcohol consumption among male adults at a slum in Kolkata, India.
Ghosh, Santanu; Samanta, Amrita; Mukherjee, Shuvankar
2012-03-01
Globally, alcohol-abuse is a major cause of mortality and morbidity. Consumption of alcohol has increased in India in the recent decades. It is imperative to know the patterns of alcohol consumption among different types of consumers to launch a well-planned nationwide programme for the prevention and control of this devastating social pathology. This community-based, cross-sectional study was undertaken to identify the patterns of alcohol intake among different types of alcohol consumers and to assess the clinical signs of chronic harmful alcohol-use. A predesigned, pretested, semi-structured alcohol-use disorders identification test (AUDIT) questionnaire was used for interviewing males, aged >18 years, selected by random sampling from an updated household list of a randomly-selected sector of the service area of the Urban Health Centre in Chetla, Kolkata, West Bengal, India. Written informed consents were obtained from all the respondents. Relevant clinical examination for chronic harmful alcohol-use was done according to the AUDIT clinical screening procedures. The results revealed that 65.8% (150/228) were current consumers of alcohol; 14% were alcohol-dependents; 8% were hazardous or harmful consumers, and 78% were non-hazardous non-harmful consumers. The mean age of the respondents at the initiation of drinking alcohol was 20.8+5.9 years. Eighty-six percent of dependents (n=21) took both Indian-made foreign liquor and locally-made alcoholic beverages. The proportions of alcohol consumers who drank alone among alcohol-dependents, hazardous or harmful consumers, and non-hazardous non-harmful consumers were 71.4%, 50%, and 7.7% respectively, and the difference was significant (p<0.01). Forty-one percent of the consumers drank at public places and workplaces, which may be socially harmful. About 38% of the dependents purchased alcohol from unlicensed liquor shops. Only 16% expressed concerns for their drinking habit mainly to the past illness. The proportion of the concerned respondents was higher in the hazardous and harmful drinking patterns than in the non-hazardous non-harmful drinking pattern, and the difference was significant (p<0.05). About 62% of the dependents had clinical signs of chronic alcohol consumption. The presence of a considerable proportion of alcohol-dependents, the low mean age at initiation of drinking alcohol, and the habit of drinking in public places and workplaces are the main areas that need special emphasis by intervention programmes.
Fetal Biometry Studies of Malaysian Pregnant Women and Comparison with International Charts
NASA Astrophysics Data System (ADS)
Adam, N.; Ramli, R. M.; Jaafar, M. S.
2010-07-01
Fetal biometry is a measurement done on fetus anatomy to relate the fetus growth with gestational age (GA). In this study [1], fetal biometry that was studied consists of biparietal diameter (BPD), abdominal circumference (AC) and femur length (FL). Studies were carried out at Maternity Unit, Hospital Pulau Penang. From the finding, it is understood that fetal biometry distinguish the normal from abnormal fetal structures and it vary among different populations, depending upon their racial [2,3] and nutrition [4,5,6]. True findings are valuable in estimating the gestational age of the fetus, abnormalities in fetus and the consideration of maternal health specific to the Malaysian population.
Kim, Ildoo; Wu, X L
2015-10-01
A structure-based Strouhal-Reynolds number relationship, St=1/(A+B/Re), has been recently proposed based on observations of laminar vortex shedding from circular cylinders in a flowing soap film. Since the new St-Re relation was derived from a general physical consideration, it raises the possibility that it may be applicable to vortex shedding from bodies other than circular ones. The work presented herein provides experimental evidence that this is the case. Our measurements also show that, in the asymptotic limit (Re→∞), St(∞)=1/A≃0.21 is constant independent of rod shapes, leaving B the only parameter that is shape dependent.
Active immunotherapy for the Treatment of Cocaine Dependence.
Kinsey, Berma M; Kosten, Thomas R; Orson, Frank M
2010-04-01
Although cocaine is illegal in most countries of the world, addiction is common and increasing in many populations, and the effectiveness of current treatment options for those afflicted has been very limited. The availability of an anti-cocaine vaccine could offer help to those who wish to quit their addiction. A number of vaccines differing in their chemical nature have been developed, and one has advanced into clinical trials. This review will discuss the successes and limitations of the various vaccines and the results of clinical trials of the vaccine using succinyl norcocaine conjugated to cholera toxin B. This latter vaccine shows considerable promise for those individuals whose antibody response is adequate..
Active immunotherapy for the Treatment of Cocaine Dependence
Kinsey, Berma M.; Kosten, Thomas R.; Orson, Frank M.
2011-01-01
Although cocaine is illegal in most countries of the world, addiction is common and increasing in many populations, and the effectiveness of current treatment options for those afflicted has been very limited. The availability of an anti-cocaine vaccine could offer help to those who wish to quit their addiction. A number of vaccines differing in their chemical nature have been developed, and one has advanced into clinical trials. This review will discuss the successes and limitations of the various vaccines and the results of clinical trials of the vaccine using succinyl norcocaine conjugated to cholera toxin B. This latter vaccine shows considerable promise for those individuals whose antibody response is adequate.. PMID:21796226
Pediatric considerations in craniofacial trauma.
Koch, Bernadette L
2014-08-01
In many respects, craniofacial trauma in children is akin to that in adults. The appearance of fractures and associated injuries is frequently similar. However, the frequencies of different types of fractures and patterns of injury in younger children vary depending on the age of the child. In addition, there are unique aspects that must be considered when imaging the posttraumatic pediatric face. Some of these are based on normal growth and development of the skull base and craniofacial structures, and others on the varying etiologies and mechanisms of craniofacial injury in children, such as injuries related to toppled furniture, nonaccidental trauma, all-terrain vehicle accidents, and impalement injuries. Copyright © 2014 Elsevier Inc. All rights reserved.
Measurement of acoustic attenuation in South Pole ice
NASA Astrophysics Data System (ADS)
IceCube Collaboration; Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Bay, R.; Bazo Alba, J. L.; Beattie, K.; Beatty, J. J.; Bechet, S.; Becker, J. K.; Becker, K.-H.; Benabderrahmane, M. L.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D. Z.; Bissok, M.; Blaufuss, E.; Boersma, D. J.; Bohm, C.; Böser, S.; Botner, O.; Bradley, L.; Braun, J.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D. F.; D'Agostino, M. V.; Danninger, M.; de Clercq, C.; Demirörs, L.; Depaepe, O.; Descamps, F.; Desiati, P.; de Vries-Uiterweerd, G.; Deyoung, T.; Díaz-Vélez, J. C.; Dreyer, J.; Dumm, J. P.; Duvoort, M. R.; Ehrlich, R.; Eisch, J.; Ellsworth, R. W.; Engdegård, O.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M. M.; Fox, B. D.; Franckowiak, A.; Franke, R.; Gaisser, T. K.; Gallagher, J.; Ganugapati, R.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Goodman, J. A.; Grant, D.; Griesel, T.; Groß, A.; Grullon, S.; Gunasingha, R. M.; Gurtner, M.; Gustafsson, L.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Homeier, A.; Hoshina, K.; Hubert, D.; Huelsnitz, W.; Hülß, J.-P.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Imlay, R. L.; Ishihara, A.; Jacobsen, J.; Japaridze, G. S.; Johansson, H.; Joseph, J. M.; Kampert, K.-H.; Kappes, A.; Karg, T.; Karle, A.; Kelley, J. L.; Kemming, N.; Kenny, P.; Kiryluk, J.; Kislat, F.; Klein, S. R.; Knops, S.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Koskinen, D. J.; Kowalski, M.; Kowarik, T.; Krasberg, M.; Krings, T.; Kroll, G.; Kuehn, K.; Kuwabara, T.; Labare, M.; Lafebre, S.; Laihem, K.; Landsman, H.; Lauer, R.; Lehmann, R.; Lennarz, D.; Lünemann, J.; Madsen, J.; Majumdar, P.; Maruyama, R.; Mase, K.; Matis, H. S.; Matusik, M.; Meagher, K.; Merck, M.; Mészáros, P.; Meures, T.; Middell, E.; Milke, N.; Montaruli, T.; Morse, R.; Movit, S. M.; Nahnhauer, R.; Nam, J. W.; Naumann, U.; Nießen, P.; Nygren, D. R.; Odrowski, S.; Olivas, A.; Olivo, M.; Ono, M.; Panknin, S.; Paul, L.; Pérez de Los Heros, C.; Petrovic, J.; Piegsa, A.; Pieloth, D.; Porrata, R.; Posselt, J.; Price, P. B.; Prikockis, M.; Przybylski, G. T.; Rawlins, K.; Redl, P.; Resconi, E.; Rhode, W.; Ribordy, M.; Rizzo, A.; Rodrigues, J. P.; Roth, P.; Rothmaier, F.; Rott, C.; Roucelle, C.; Ruhe, T.; Rutledge, D.; Ruzybayev, B.; Ryckbosch, D.; Sander, H.-G.; Sarkar, S.; Schatto, K.; Schlenstedt, S.; Schmidt, T.; Schneider, D.; Schukraft, A.; Schultes, A.; Schulz, O.; Schunck, M.; Seckel, D.; Semburg, B.; Seo, S. H.; Sestayo, Y.; Seunarine, S.; Silvestri, A.; Slipak, A.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stephens, G.; Stezelberger, T.; Stokstad, R. G.; Stoyanov, S.; Strahler, E. A.; Straszheim, T.; Sullivan, G. W.; Swillens, Q.; Taboada, I.; Tamburro, A.; Tarasova, O.; Tepe, A.; Ter-Antonyan, S.; Tilav, S.; Toale, P. A.; Tosi, D.; Turčan, D.; van Eijndhoven, N.; Vandenbroucke, J.; van Overloop, A.; van Santen, J.; Voigt, B.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Walter, M.; Wendt, C.; Westerhoff, S.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Wikström, G.; Williams, D. R.; Wischnewski, R.; Wissing, H.; Woschnagg, K.; Xu, C.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; IceCube Collaboration
2011-01-01
Using the South Pole Acoustic Test Setup (SPATS) and a retrievable transmitter deployed in holes drilled for the IceCube experiment, we have measured the attenuation of acoustic signals by South Pole ice at depths between 190 m and 500 m. Three data sets, using different acoustic sources, have been analyzed and give consistent results. The method with the smallest systematic uncertainties yields an amplitude attenuation coefficient α = 3.20 ± 0.57 km-1 between 10 and 30 kHz, considerably larger than previous theoretical estimates. Expressed as an attenuation length, the analyses give a consistent result for λ ≡ 1/α of ˜300 m with 20% uncertainty. No significant depth or frequency dependence has been found.
The environmental impact of poverty: evidence from firewood collection in rural Nepal.
Baland, Jean-Marie; Bardhan, Pranab; Das, Sanghamitra; Mookherjee, Dilip; Sarkar, Rinki
2010-01-01
We investigate determinants of household firewood collection in rural Nepal, using 1995-96 and 2002-3 World Bank Living Standards Measurement Survey (LSMS) data. We incorporate village fixed effects, endogenous censoring, measurement error in living standards and heterogeneous effects of different household assets. We find no evidence in favor of the poverty-environment hypothesis. The evidence for the environmental Kuznets curve depends on the precise measure of living standards and time period studied. Firewood collections fall with a transition to modern occupations and rise with increasing population and household division. The local interhousehold collection externality is negligible, indicating that policy interventions are justified only by ecological considerations or nonlocal spillovers.
Investigation of the Relationship between Undercooling and Solidification Velocity
NASA Technical Reports Server (NTRS)
Bayuzick, Robert J.; Hofmeister, William H.
2004-01-01
This work was aimed at reconciling the differences between experimental measurements of the theoretical predictions of the solidification velocity as a function of undercooling. The theory proposed by Boettinger, Coriell and Trivedi (the BCT theory) has been one of the most widely used models for describing the nature of the solidification of undercooled metals and alloys. However, for undercoolings greater than about 5% of the absolute melting temperature, there is considerable discrepancy between theory and experiment. At these large undercoolings, experimental results exhibit a much lessened dependency of solidification velocity on undercooling than is predicted by theory. Furthermore, unpredicted plateaus in the solidification velocity as a function of undercooling are observed.
Protein disorder is positively correlated with gene expression in E. coli
Paliy, Oleg; Gargac, Shawn M.; Cheng, Yugong; Uversky, Vladimir N.; Dunker, A. Keith
2009-01-01
We considered on a global scale the relationship between the predicted fraction of protein disorder and RNA and protein expression in E. coli. Fraction of protein disorder correlated positively with both measured RNA expression levels of E. coli genes in three different growth media and with predicted abundance levels of E. coli proteins. Though weak, the correlation was highly significant. Correlation of protein disorder with RNA expression did not depend on the growth rate of E. coli cultures and was not caused by a small subset of genes showing exceptionally high concordance in their disorder and expression levels. Global analysis was complemented by detailed consideration of several groups of proteins. PMID:18465893
Wireless powering of e -swimmers
NASA Astrophysics Data System (ADS)
Roche, Jérome; Carrara, Serena; Sanchez, Julien; Lannelongue, Jérémy; Loget, Gabriel; Bouffier, Laurent; Fischer, Peer; Kuhn, Alexander
2014-10-01
Miniaturized structures that can move in a controlled way in solution and integrate various functionalities are attracting considerable attention due to the potential applications in fields ranging from autonomous micromotors to roving sensors. Here we introduce a concept which allows, depending on their specific design, the controlled directional motion of objects in water, combined with electronic functionalities such as the emission of light, sensing, signal conversion, treatment and transmission. The approach is based on electric field-induced polarization, which triggers different chemical reactions at the surface of the object and thereby its propulsion. This results in a localized electric current that can power in a wireless way electronic devices in water, leading to a new class of electronic swimmers (e-swimmers).
NASA Astrophysics Data System (ADS)
DeVore, Matthew S.; Gull, Stephen F.; Johnson, Carey K.
2013-08-01
We analyzed single molecule FRET burst measurements using Bayesian nested sampling. The MultiNest algorithm produces accurate FRET efficiency distributions from single-molecule data. FRET efficiency distributions recovered by MultiNest and classic maximum entropy are compared for simulated data and for calmodulin labeled at residues 44 and 117. MultiNest compares favorably with maximum entropy analysis for simulated data, judged by the Bayesian evidence. FRET efficiency distributions recovered for calmodulin labeled with two different FRET dye pairs depended on the dye pair and changed upon Ca2+ binding. We also looked at the FRET efficiency distributions of calmodulin bound to the calcium/calmodulin dependent protein kinase II (CaMKII) binding domain. For both dye pairs, the FRET efficiency distribution collapsed to a single peak in the case of calmodulin bound to the CaMKII peptide. These measurements strongly suggest that consideration of dye-protein interactions is crucial in forming an accurate picture of protein conformations from FRET data.
DeVore, Matthew S.; Gull, Stephen F.; Johnson, Carey K.
2013-01-01
We analyze single molecule FRET burst measurements using Bayesian nested sampling. The MultiNest algorithm produces accurate FRET efficiency distributions from single-molecule data. FRET efficiency distributions recovered by MultiNest and classic maximum entropy are compared for simulated data and for calmodulin labeled at residues 44 and 117. MultiNest compares favorably with maximum entropy analysis for simulated data, judged by the Bayesian evidence. FRET efficiency distributions recovered for calmodulin labeled with two different FRET dye pairs depended on the dye pair and changed upon Ca2+ binding. We also looked at the FRET efficiency distributions of calmodulin bound to the calcium/calmodulin dependent protein kinase II (CaMKII) binding domain. For both dye pairs, the FRET efficiency distribution collapsed to a single peak in the case of calmodulin bound to the CaMKII peptide. These measurements strongly suggest that consideration of dye-protein interactions is crucial in forming an accurate picture of protein conformations from FRET data. PMID:24223465
In silico models for the prediction of dose-dependent human hepatotoxicity
NASA Astrophysics Data System (ADS)
Cheng, Ailan; Dixon, Steven L.
2003-12-01
The liver is extremely vulnerable to the effects of xenobiotics due to its critical role in metabolism. Drug-induced hepatotoxicity may involve any number of different liver injuries, some of which lead to organ failure and, ultimately, patient death. Understandably, liver toxicity is one of the most important dose-limiting considerations in the drug development cycle, yet there remains a serious shortage of methods to predict hepatotoxicity from chemical structure. We discuss our latest findings in this area and present a new, fully general in silico model which is able to predict the occurrence of dose-dependent human hepatotoxicity with greater than 80% accuracy. Utilizing an ensemble recursive partitioning approach, the model classifies compounds as toxic or non-toxic and provides a confidence level to indicate which predictions are most likely to be correct. Only 2D structural information is required and predictions can be made quite rapidly, so this approach is entirely appropriate for data mining applications and for profiling large synthetic and/or virtual libraries.
Zelovich, Tamar; Hansen, Thorsten; Liu, Zhen-Fei; ...
2017-03-02
A parameter-free version of the recently developed driven Liouville-von Neumann equation [T. Zelovich et al., J. Chem. Theory Comput. 10(8), 2927-2941 (2014)] for electronic transport calculations in molecular junctions is presented. The single driving rate, appearing as a fitting parameter in the original methodology, is replaced by a set of state-dependent broadening factors applied to the different single-particle lead levels. These broadening factors are extracted explicitly from the self-energy of the corresponding electronic reservoir and are fully transferable to any junction incorporating the same lead model. Furthermore, the performance of the method is demonstrated via tight-binding and extended Hückel calculationsmore » of simple junction models. Our analytic considerations and numerical results indicate that the developed methodology constitutes a rigorous framework for the design of "black-box" algorithms to simulate electron dynamics in open quantum systems out of equilibrium.« less
Estimation of photosynthetic capacity using MODIS polarization: 1988 proposal to NASA Headquarters
NASA Technical Reports Server (NTRS)
Vanderbilt, Vern C.
1992-01-01
The remote sensing community has clearly identified the utility of NDVI (normalized difference vegetation index) and SR (simple ratio) and other vegetation indices for estimating such metrics of landscape ecology as green foliar biomass, photosynthetic capacity, and net primary production. Both theoretical and empirical investigations have established cause and effect relationships between the photosynthetic process in plant canopies and these combinations of remotely sensed data. Yet it has also been established that the relationships exhibit considerable variability that appears to be ecosystem-dependent and may represent a source of ecologically important information. The overall hypothesis of this proposal is that the ecosystem-dependent variability in the various vegetation indices is in part attributable to the effects of specular reflection. The polarization channels on MODIS provide the potential to estimate this specularly reflected light and allow the modification of the vegetation indices to better measure the photosynthetic process in plant canopies. In addition, these polarization channels potentially provide additional ecologically important information about the plant canopy.
Devore, Matthew S; Gull, Stephen F; Johnson, Carey K
2013-08-30
We analyze single molecule FRET burst measurements using Bayesian nested sampling. The MultiNest algorithm produces accurate FRET efficiency distributions from single-molecule data. FRET efficiency distributions recovered by MultiNest and classic maximum entropy are compared for simulated data and for calmodulin labeled at residues 44 and 117. MultiNest compares favorably with maximum entropy analysis for simulated data, judged by the Bayesian evidence. FRET efficiency distributions recovered for calmodulin labeled with two different FRET dye pairs depended on the dye pair and changed upon Ca 2+ binding. We also looked at the FRET efficiency distributions of calmodulin bound to the calcium/calmodulin dependent protein kinase II (CaMKII) binding domain. For both dye pairs, the FRET efficiency distribution collapsed to a single peak in the case of calmodulin bound to the CaMKII peptide. These measurements strongly suggest that consideration of dye-protein interactions is crucial in forming an accurate picture of protein conformations from FRET data.
Neural learning circuits utilizing nano-crystalline silicon transistors and memristors.
Cantley, Kurtis D; Subramaniam, Anand; Stiegler, Harvey J; Chapman, Richard A; Vogel, Eric M
2012-04-01
Properties of neural circuits are demonstrated via SPICE simulations and their applications are discussed. The neuron and synapse subcircuits include ambipolar nano-crystalline silicon transistor and memristor device models based on measured data. Neuron circuit characteristics and the Hebbian synaptic learning rule are shown to be similar to biology. Changes in the average firing rate learning rule depending on various circuit parameters are also presented. The subcircuits are then connected into larger neural networks that demonstrate fundamental properties including associative learning and pulse coincidence detection. Learned extraction of a fundamental frequency component from noisy inputs is demonstrated. It is then shown that if the fundamental sinusoid of one neuron input is out of phase with the rest, its synaptic connection changes differently than the others. Such behavior indicates that the system can learn to detect which signals are important in the general population, and that there is a spike-timing-dependent component of the learning mechanism. Finally, future circuit design and considerations are discussed, including requirements for the memristive device.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zelovich, Tamar; Hansen, Thorsten; Liu, Zhen-Fei
A parameter-free version of the recently developed driven Liouville-von Neumann equation [T. Zelovich et al., J. Chem. Theory Comput. 10(8), 2927-2941 (2014)] for electronic transport calculations in molecular junctions is presented. The single driving rate, appearing as a fitting parameter in the original methodology, is replaced by a set of state-dependent broadening factors applied to the different single-particle lead levels. These broadening factors are extracted explicitly from the self-energy of the corresponding electronic reservoir and are fully transferable to any junction incorporating the same lead model. Furthermore, the performance of the method is demonstrated via tight-binding and extended Hückel calculationsmore » of simple junction models. Our analytic considerations and numerical results indicate that the developed methodology constitutes a rigorous framework for the design of "black-box" algorithms to simulate electron dynamics in open quantum systems out of equilibrium.« less
Critical ligand binding reagent preparation/selection: when specificity depends on reagents.
Rup, Bonita; O'Hara, Denise
2007-05-11
Throughout the life cycle of biopharmaceutical products, bioanalytical support is provided using ligand binding assays to measure the drug product for pharmacokinetic, pharmacodynamic, and immunogenicity studies. The specificity and selectivity of these ligand binding assays are highly dependent on the ligand binding reagents. Thus the selection, characterization, and management processes for ligand binding reagents are crucial to successful assay development and application. This report describes process considerations for selection and characterization of ligand binding reagents that are integral parts of the different phases of assay development. Changes in expression, purification, modification, and storage of the ligand binding reagents may have a profound effect on the ligand binding assay performance. Thus long-term management of the critical ligand binding assay reagents is addressed including suggested characterization criteria that allow ligand binding reagents to be used in as consistent a manner as possible. Examples of challenges related to the selection, modification, and characterization of ligand binding reagents are included.
Dislocation loop formation in model FeCrAl alloys after neutron irradiation below 1 dpa
Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; ...
2017-08-01
FeCrAl alloys with varying compositions and microstructures are under consideration for accident-tolerant fuel cladding, but limited details exist on dislocation loop formation and growth for this class of alloys under neutron irradiation. Four model FeCrAl alloys with chromium contents ranging from 10.01 to 17.51 wt % and alunimum contents of 4.78 to 2.93 wt % were neutron irradiated to doses of 0.3–0.8 displacements per atom (dpa) at temperatures of 335–355°C. On-zone STEM imaging revealed a mixed population of black dots and larger dislocation loops with either a/2< 111 > or a< 100 > Burgers vectors. Weak composition dependencies were observedmore » and varied depending on whether the defect size, number density, or ratio of defect types was of interest. Here, the results were found to mirror those of previous studies on FeCrAl and FeCr alloys irradiated under similar conditions, although distinct differences exist.« less
Dislocation loop formation in model FeCrAl alloys after neutron irradiation below 1 dpa
NASA Astrophysics Data System (ADS)
Field, Kevin G.; Briggs, Samuel A.; Sridharan, Kumar; Yamamoto, Yukinori; Howard, Richard H.
2017-11-01
FeCrAl alloys with varying compositions and microstructures are under consideration for accident-tolerant fuel cladding, but limited details exist on dislocation loop formation and growth for this class of alloys under neutron irradiation. Four model FeCrAl alloys with chromium contents ranging from 10.01 to 17.51 wt % and aluminum contents of 4.78 to 2.93 wt % were neutron irradiated to doses of 0.3-0.8 displacements per atom (dpa) at temperatures of 335-355 °C. On-zone STEM imaging revealed a mixed population of black dots and larger dislocation loops with either a / 2 〈 111 〉 or a 〈 100 〉 Burgers vectors. Weak composition dependencies were observed and varied depending on whether the defect size, number density, or ratio of defect types was of interest. Results were found to mirror those of previous studies on FeCrAl and FeCr alloys irradiated under similar conditions, although distinct differences exist.
Gutierrez, A.; Laureti, L.; Crussard, S.; Abida, H.; Rodríguez-Rojas, A.; Blázquez, J.; Baharoglu, Z.; Mazel, D.; Darfeuille, F.; Vogel, J.; Matic, I.
2013-01-01
Regardless of their targets and modes of action, subinhibitory concentrations of antibiotics can have an impact on cell physiology and trigger a large variety of cellular responses in different bacterial species. Subinhibitory concentrations of β-lactam antibiotics cause reactive oxygen species production and induce PolIV-dependent mutagenesis in Escherichia coli. Here we show that subinhibitory concentrations of β-lactam antibiotics induce the RpoS regulon. RpoS-regulon induction is required for PolIV-dependent mutagenesis because it diminishes the control of DNA-replication fidelity by depleting MutS in E. coli, Vibrio cholerae and Pseudomonas aeruginosa. We also show that in E. coli, the reduction in mismatch-repair activity is mediated by SdsR, the RpoS-controlled small RNA. In summary, we show that mutagenesis induced by subinhibitory concentrations of antibiotics is a genetically controlled process. Because this mutagenesis can generate mutations conferring antibiotic resistance, it should be taken into consideration for the development of more efficient antimicrobial therapeutic strategies. PMID:23511474
NASA Astrophysics Data System (ADS)
Afzali, R.; Alizadeh, A.
2017-12-01
The behavior of non-interacting and interacting polarization under influence of fluctuations of the superconducting gap with D-wave symmetry and under consideration of the gap dependence on nano- grain size is obtained in terms of the frequency, temperature and the size at zero and finite temperatures for rectangular cuprate nano-superconducting grains. By using Eliashberg equations and applying the relations of the fermionic dispersion for the hole-doped and electron-doped cuprates, we numerically compute the real part of size-dependent polarization for both types of cuprates. We show that the peak of real part of polarization moves to higher frequency by including the additional fluctuating part of gap (or the nano-size effect). Also, we obtain the temperatures for different frequencies, in which the effect of gap fluctuations fades. In the case of size-dependent gap, there is a critical frequency; for frequencies lower (higher) than the critical frequency, the nano-effect weakens (improves) the superconducting state. Moreover, it is concluded that the real part of polarization for hole- doped cuprates in terms of the grain size has more significant amount in comparison with electron-doped ones.
Bimczok, R; Gers-Barlag, H; Mundt, C; Klette, E; Bielfeldt, S; Rudolph, T; Pflucker, F; Heinrich, U; Tronnier, H; Johncock, W; Klebon, B; Westenfelder, H; Flosser-Muller, H; Jenni, K; Kockott, D; Lademann, J; Herzog, B; Rohr, M
2007-01-01
It is often debated that the protection against solar-induced erythema under real conditions is dependent upon the amount of sunscreen applied. It is believed that when too little is applied a lower sun protection than indicated on the label will result. The aim of this study was to quantify this effect. In this multicenter study, the influence of three different amounts (0.5, 1.0, 2.0 mg/cm(2)) of three commercial sunscreen products in three reliable test centers was investigated according to the test protocol of The International Sun Protection Factor Test Method. The main result was a linear dependence of the SPF on the quantity applied. Taking into consideration the volunteer-specific variations, an exponential dependence of confidence interval of the in vivo SPF and amount applied was found. The highest amount applied (2.0 mg/cm(2)) was linked to the lowest confidence intervals. Thus, from the point of view of producing reliable and reproducible in vivo results under laboratory conditions, the recommendation of this multicenter study is an application quantity of 2.0 mg/cm(2).
Recent advances concerning an understanding of sound transmission through engine nozzles and jets
NASA Technical Reports Server (NTRS)
Bechert, D.; Michel, U.; Dfizenmaier, E.
1978-01-01
Experiments on the interaction between a turbulent jet and pure tone sound coming from inside the jet nozzle are reported. This is a model representing the sound transmission from sound sources in jet engines through the nozzle and the jet flow into the far field. It is shown that pure tone sound at low frequencies is considerably attenuated by the jet flow, whereas it is conserved at higher frequencies. On the other hand, broadband jet noise can be amplified considerably by a pure tone excitation. Both effects seem not to be interdependent. Knowledge on how they are created and on relevant parameter dependences allow new considerations for the development of sound attenuators.
Meier-Hirmer, Carolina; Schumacher, Martin
2013-06-20
The aim of this article is to propose several methods that allow to investigate how and whether the shape of the hazard ratio after an intermediate event depends on the waiting time to occurrence of this event and/or the sojourn time in this state. A simple multi-state model, the illness-death model, is used as a framework to investigate the occurrence of this intermediate event. Several approaches are shown and their advantages and disadvantages are discussed. All these approaches are based on Cox regression. As different time-scales are used, these models go beyond Markov models. Different estimation methods for the transition hazards are presented. Additionally, time-varying covariates are included into the model using an approach based on fractional polynomials. The different methods of this article are then applied to a dataset consisting of four studies conducted by the German Breast Cancer Study Group (GBSG). The occurrence of the first isolated locoregional recurrence (ILRR) is studied. The results contribute to the debate on the role of the ILRR with respect to the course of the breast cancer disease and the resulting prognosis. We have investigated different modelling strategies for the transition hazard after ILRR or in general after an intermediate event. Including time-dependent structures altered the resulting hazard functions considerably and it was shown that this time-dependent structure has to be taken into account in the case of our breast cancer dataset. The results indicate that an early recurrence increases the risk of death. A late ILRR increases the hazard function much less and after the successful removal of the second tumour the risk of death is almost the same as before the recurrence. With respect to distant disease, the appearance of the ILRR only slightly increases the risk of death if the recurrence was treated successfully. It is important to realize that there are several modelling strategies for the intermediate event and that each of these strategies has restrictions and may lead to different results. Especially in the medical literature considering breast cancer development, the time-dependency is often neglected in the statistical analyses. We show that the time-varying variables cannot be neglected in the case of ILRR and that fractional polynomials are a useful tool for finding the functional form of these time-varying variables.
Morissette, Sandra B.; Gulliver, Suzy B.; Kamholz, Barbara W.; Duade, James; Farchione, Todd; Devine, Eric; Brown, Timothy A.; Barlow, David H.; Ciraulo, Domenic
2008-01-01
Tobacco use is disproportionately represented among both alcohol-use disorders (AUDs) and anxiety disorders (ANX) compared to the general population (Kalman et al., 2005). Despite this common overlap, little is known about how smokers with co-occurring AUD-ANX differ from their nonsmoking counterparts. Seventy-two patients participated in a larger clinical trial evaluating the efficacy of venlafaxine and cognitive-behavioral therapy for AUD-ANX. Differences between daily smokers (n = 23), chippers (n = 12) and nonsmokers (n = 37) with AUD-ANX were examined with respect to intensity and frequency of alcohol use, anxiety symptoms, depressed mood, and stress. Point prevalence of current daily smoking was 31.9%, which is considerably lower than traditionally reported in AUD studies. Consistent with predictions, daily smokers reported higher levels of alcohol dependence, average drinks per drinking occasion, and peak blood concentration levels in a day than nonsmokers during the 90 days prior to assessment. Chippers were nonsignificantly different from either smokers or nonsmokers. Smokers and nonsmokers did not differ with respect to percent heavy drinking days or emotional symptoms. PMID:18656314
Wavelet analysis enables system-independent texture analysis of optical coherence tomography images.
Lingley-Papadopoulos, Colleen A; Loew, Murray H; Zara, Jason M
2009-01-01
Texture analysis for tissue characterization is a current area of optical coherence tomography (OCT) research. We discuss some of the differences between OCT systems and the effects those differences have on the resulting images and subsequent image analysis. In addition, as an example, two algorithms for the automatic recognition of bladder cancer are compared: one that was developed on a single system with no consideration for system differences, and one that was developed to address the issues associated with system differences. The first algorithm had a sensitivity of 73% and specificity of 69% when tested using leave-one-out cross-validation on data taken from a single system. When tested on images from another system with a different central wavelength, however, the method classified all images as cancerous regardless of the true pathology. By contrast, with the use of wavelet analysis and the removal of system-dependent features, the second algorithm reported sensitivity and specificity values of 87 and 58%, respectively, when trained on images taken with one imaging system and tested on images taken with another.
Wavelet analysis enables system-independent texture analysis of optical coherence tomography images
NASA Astrophysics Data System (ADS)
Lingley-Papadopoulos, Colleen A.; Loew, Murray H.; Zara, Jason M.
2009-07-01
Texture analysis for tissue characterization is a current area of optical coherence tomography (OCT) research. We discuss some of the differences between OCT systems and the effects those differences have on the resulting images and subsequent image analysis. In addition, as an example, two algorithms for the automatic recognition of bladder cancer are compared: one that was developed on a single system with no consideration for system differences, and one that was developed to address the issues associated with system differences. The first algorithm had a sensitivity of 73% and specificity of 69% when tested using leave-one-out cross-validation on data taken from a single system. When tested on images from another system with a different central wavelength, however, the method classified all images as cancerous regardless of the true pathology. By contrast, with the use of wavelet analysis and the removal of system-dependent features, the second algorithm reported sensitivity and specificity values of 87 and 58%, respectively, when trained on images taken with one imaging system and tested on images taken with another.
NASA Astrophysics Data System (ADS)
Zaitsev, Vladimir Y.; Radostin, Andrey V.; Pasternak, Elena; Dyskin, Arcady
2016-04-01
Conventionally the interpretation of wave velocities and their variations under load is conducted assuming that closable cracks have simple planar shapes, like the popular model of penny-shape cracks. For such cracks, the proportion between complementary variations in different elastic parameters of rocks (such as S- and P-wave velocities) is strictly pre-determined, in particular, it is independent of the crack aspect ratio and rather weakly dependent on the Poisson's ratio of the intact rock. Real rocks, however, contain multitude of cracks of different geometry. Faces of such cracks can exhibit complex modes of interaction when closed by external load, which may result in very different ratios between normal- and shear compliances of such defects. In order to describe the reduction of different elastic moduli, we propose a model in which the compliances of crack-like defects are explicitly decoupled and are not predetermined, so that the ratio q between total normal- and shear- compliances imparted to the rock mass (as well as individual values of these compliances) can be estimated from experimental data on reduction of different elastic moduli (e.g., pressure dependences of P- and S-wave velocities). Physically, the so-extracted ratio q can be interpreted as intrinsic property of individual crack-like defects similar to each other, or as a characteristic of proportion between concentrations of pure normal cracks with very large q and pure shear cracks with q→0. The latter case can correspond, e.g., to saturated cracks in which weakly-compressible liquid prevents crack closing under normal loading. It can be shown that for conventional dry planar cracks, the compliance ratio is q ˜2. The developed model applied to the data on wave-velocity variations with external pressure indicates that elastic properties of the real crack-like defects in rocks can differ considerably from the usually assumed ones. Comparison with experimental data on variations P- and S-wave velocities with hydrostatic compression of different dry and saturated rocks (sandstones, Westerly granite and Webatuck dolomite, etc.) shows that our model is accurate in a wide range of pressures with constant (i.e., pressure-independent) values of parameter q. Furthermore, the determined values of the latter are considerably different from those of conventional cracks. In particular, although all saturated samples have values q <1, the simplified approximation q=0 (i.e., the absence of normal compressibility that is often assumed for wet cracks) leads to large errors in the prediction of complementary variations in the shear- and bulk elastic moduli. Among dry sandstones, the majority have q >2 and many sandstones exhibit unusually high q»1 suggesting quite rough and tortoise nature of real cracks in those rocks. We demonstrate that in such cases, the use of the conventional assumption q ˜2 typical of penny-shape cracks leads to striking inconsistency between the predicted and experimentally observed crack-induced complementary variations in different elastic moduli. Furthermore, among samples with q»1, we revealed numerous examples that demonstrate negative Poisson's ratio at low pressures. VYZ and AVR acknowledge the financial support by RFBR grant No 15-05-05143.
28 CFR 104.41 - Amount of compensation.
Code of Federal Regulations, 2010 CFR
2010-07-01
... claimant is entitled, the Special Master shall take into consideration the harm to the claimant, the facts... claimant may include the financial needs or financial resources of the claimant or the victim's dependents...
Psychological Time and Sociology: A Research Agenda.
ERIC Educational Resources Information Center
Hogan, H. Wayne
1979-01-01
Psychological time is hypothesized as potentially being both an independent and a dependent dimension associated with such sociological and psychological phenomena as social change, environmental design, personal space, esthetics, and color considerations. (Author)
Seated Occupant Apparent Mass Characteristics Under Automotive Postures and Vertical Vibration
NASA Astrophysics Data System (ADS)
RAKHEJA, S.; HARU, I.; BOILEAU, P.-É.
2002-05-01
The biodynamic apparent mass response characteristics of 24 human subjects (12 males and 12 females) seated under representative automotive postures with hands-in-lap (passengers) and hands-on-steering wheel (drivers) are reported. The measurements were carried out under white noise vertical excitations of 0·25, 0·5 and 1·0m/s2r.m.s. acceleration magnitudes in the 0·5-40Hz frequency range and a track measured input (1·07m/s2). The measured data have been analyzed to study the effects of hands position, body mass, magnitude and type of vibration excitation, and feet position, on the biodynamic response expressed in terms of apparent mass. A comparison of the measured response of subjects assuming typical automotive postures involving inclined cushion, inclined backrest and full use of backrest support with data determined under different postural conditions and excitation levels revealed considerable differences. The biodynamic response of automobile occupants seated with hands in lap, peaks in the 6·5-8·6Hz frequency range, which is considerably higher than the reported range of fundamental frequencies (4·5-5Hz) in most other studies involving different experimental conditions. The peak magnitude tends to decrease considerably for the driving posture with hands-on-steering wheel, while a second peak in the 8-12 Hz range becomes more apparent for this posture. The results suggest that biodynamic response of occupants seated in automotive seats and subject to vertical vibration need to be characterized, as a minimum, by two distinct functions for passenger and driving postures. A higher body mass, in general, yields higher peak magnitude response and lower corresponding frequency for both postures. The strong dependence of the response on the body mass is further demonstrated by grouping the measured data into four different mass ranges: less than 60 kg, between 60·5 and 70 kg, between 70·5 and 80 kg, and above 80 kg. From the results, it is concluded that hands position and body mass have the most significant influence on the apparent mass response under automotive posture and vibration.
Size and burden of mental disorders in Europe--a critical review and appraisal of 27 studies.
Wittchen, Hans-Ulrich; Jacobi, Frank
2005-08-01
Epidemiological data on a wide range of mental disorders from community studies conducted in European countries are presented to determine the availability and consistency of prevalence, disability and treatment findings for the EU. Using a stepwise multimethod approach, 27 eligible studies with quite variable designs and methods including over 150,000 subjects from 16 European countries were identified. Prevalence: On the basis of meta-analytic techniques as well as on reanalyses of selected data sets, it is estimated that about 27% (equals 82.7 million; 95% CI: 78.5-87.1) of the adult EU population, 18-65 of age, is or has been affected by at least one mental disorder in the past 12 months. Taking into account the considerable degree of comorbidity (about one third had more than one disorder), the most frequent disorders are anxiety disorders, depressive, somatoform and substance dependence disorders. When taking into account design, sampling and other methodological differences between studies, little evidence seems to exist for considerable cultural or country variation. Disability and treatment: despite very divergent and fairly crude assessment strategies, the available data consistently demonstrate (a) an association of all mental disorders with a considerable disability burden in terms of number of work days lost (WLD) and (b) generally low utilization and treatment rates. Only 26% of all cases had any consultation with professional health care services, a finding suggesting a considerable degree of unmet need. The paper highlights considerable future research needs for coordinated EU studies across all disorders and age groups. As prevalence estimates could not simply be equated with defined treatment needs, such studies should determine the degree of met and unmet needs for services by taking into account severity, disability and comorbidity. These needs are most pronounced for the new EU member states as well as more generally for adolescent and older populations.
Land Use for Edible Protein of Animal Origin—A Review
Flachowsky, Gerhard; Meyer, Ulrich; Südekum, Karl-Heinz
2017-01-01
Simple Summary The growing world population has led to a higher demand for more and better quality food. In the future, there will be increasingly strong competition for arable land and other non-renewable resources. Proteins of animal origin are very valuable sources of essential nutrients, but their production consumes resources and causes emissions. The aim of this study was to calculate exemplarily the land use for production of edible animal protein from different animal species and categories in consideration of important influencing factors. Large differences were found with the highest amounts per kilogram of body weight produced by broiler chickens and the lowest yields in edible protein and the highest land need observed for beef cattle. Abstract The present period is characterized by a growing world population and a higher demand for more and better quality food, as well as other products for an improved standard of living. In the future, there will be increasingly strong competition for arable land and non-renewable resources such as fossil carbon-sources, water, and some minerals, as well as between food, feed, fuel, fiber, flowers, and fun (6 F’s). Proteins of animal origin like milk, meat, fish, eggs and, probably, insects are very valuable sources of essential amino acids, minerals and vitamins, but their production consumes some non-renewable resources including arable land and causes considerable emissions. Therefore, this study´s objective was to calculate some examples of the land use (arable land and grassland) for production of edible animal protein taking into consideration important animal species/categories, levels of plant and animal yields, the latter estimated with and without co-products from agriculture, and the food/biofuel industry in animal feeding. There are large differences between animal species/categories and their potential to produce edible protein depending on many influencing variables. The highest amounts per kilogram body weight are produced by growing broiler chicken followed by laying hens and dairy cows; the lowest yields in edible protein and the highest land need were observed for beef cattle. This review clearly indicates that the production of food of animal origin is a very complex process, and selective considerations, i.e., focusing on single factors, do not provide an assessment that reflects the complexity of the subject. PMID:28335483
Seing, Ida; MacEachen, Ellen; Ekberg, Kerstin; Ståhl, Christian
2015-01-01
The aim was to analyze the role and activities of employers with regard to return to work (RTW), in local workplace practice. Semi-structured interviews were conducted with sick-listed workers and their supervisors in 18 workplaces (n = 36). The analytical approach to study the role of employers in RTW was based on the three-domain model of social corporate responsibility. The model illustrates the linkage between corporations and their social environment, and consists of three areas of corporate responsibility: economic, legal and ethical. Employers had difficulties in taking social responsibility for RTW, in that economic considerations regarding their business took precedence over legal and ethical considerations. Employers engaged in either "RTW activities" or "transition activities" that were applied differently depending on how valued sick-listed workers were considered to be to their business, and on the nature of the job (e.g., availability of suitable work adjustments). This study suggests that Swedish legislation and policies does not always adequately prompt employers to engage in RTW. There is a need for further attention to the organizational conditions for employers to take social responsibility for RTW in the context of business pressure and work intensification. Employers may have difficulties in taking social responsibility for RTW when economic considerations regarding their business take precedence over legal and ethical considerations. Rehabilitation professionals should be aware of that outcomes of an RTW process can be influenced by the worker's value to the employer and the nature of the job (e.g., availability of suitable work adjustments). "Low-value" workers at workplaces with limited possibilities to offer workplace adjustments may run a high risk of dismissal. Swedish legislation and policies may need reforms to put more pressure on employers to promote RTW.
Modelling the effects of trade-offs between long and short-term objectives in fisheries management.
Mardle, Simon; Pascoe, Sean
2002-05-01
Fisheries management is typically a complex problem, from both an environmental and political perspective. The main source of conflict occurs between the need for stock conservation and the need for fishing community well-being, which is typically measured by employment and income levels. For most fisheries, overexploitation of the stock requires a reduction in the level of fishing activity. While this may lead to long-term benefits (both conservation and economic), it also leads to a short-term reduction in employment and regional incomes. In regions which are heavily dependent on fisheries, short-term consequences of conservation efforts may be considerable. The relatively high degree of scientific uncertainty with respect to the status of the stocks and the relatively short lengths of political terms of office, generally give rise to the short-run view taking the highest priority when defining policy objectives. In this paper, a multi-objective model of the North Sea is developed that incorporates both long-term and short-term objectives. Optimal fleet sizes are estimated taking into consideration different preferences between the defined short-term and long-term objectives. The subsequent results from the model give the short-term and long-term equilibrium status of the fishery incorporating the effects of the short-term objectives. As would be expected, an optimal fleet from a short-term perspective is considerably larger than an optimal fleet from a long-run perspective. Conversely, stock sizes and sustainable yields are considerably lower in the long-term if a short-term perspective is used in setting management policies. The model results highlight what is essentially a principal-agent problem, with the objectives of the policy makers not necessarily reflecting the objectives of society as a whole.
2012-01-01
In face of the multiple controversies surrounding the DSM process in general and the development of DSM-5 in particular, we have organized a discussion around what we consider six essential questions in further work on the DSM. The six questions involve: 1) the nature of a mental disorder; 2) the definition of mental disorder; 3) the issue of whether, in the current state of psychiatric science, DSM-5 should assume a cautious, conservative posture or an assertive, transformative posture; 4) the role of pragmatic considerations in the construction of DSM-5; 5) the issue of utility of the DSM – whether DSM-III and IV have been designed more for clinicians or researchers, and how this conflict should be dealt with in the new manual; and 6) the possibility and advisability, given all the problems with DSM-III and IV, of designing a different diagnostic system. Part I of this article took up the first two questions. Part II will take up the second two questions. Question 3 deals with the question as to whether DSM-V should assume a conservative or assertive posture in making changes from DSM-IV. That question in turn breaks down into discussion of diagnoses that depend on, and aim toward, empirical, scientific validation, and diagnoses that are more value-laden and less amenable to scientific validation. Question 4 takes up the role of pragmatic consideration in a psychiatric nosology, whether the purely empirical considerations need to be tempered by considerations of practical consequence. As in Part 1 of this article, the general introduction, as well as the introductions and conclusions for the specific questions, are written by James Phillips, and the responses to commentaries are written by Allen Frances. PMID:22512887
DOE Office of Scientific and Technical Information (OSTI.GOV)
Haslam, J J; Wall, M A; Johnson, D L
We have measured and modeled the change in electrical resistivity due to partial transformation to the martensitic {alpha}{prime}-phase in a {delta}-phase Pu-Ga matrix. The primary objective is to relate the change in resistance, measured with a 4-probe technique during the transformation, to the volume fraction of the {alpha}{prime} phase created in the microstructure. Analysis by finite element methods suggests that considerable differences in the resistivity may be anticipated depending on the orientational and morphological configurations of the {alpha}{prime} particles. Finite element analysis of the computed resistance of an assembly of lenticular shaped particles indicates that series resistor or parallel resistormore » approximations are inaccurate and can lead to an underestimation of the predicted amount of {alpha}{prime} in the sample by 15% or more. Comparison of the resistivity of a simulated network of partially transformed grains or portions of grains suggests that a correction to the measured resistivity allows quantification of the amount of {alpha}{prime} phase in the microstructure with minimal consideration of how the {alpha}{prime} morphology may evolve. It is found that the average of the series and parallel resistor approximations provide the most accurate relationship between the measured resistivity and the amount of {alpha}{prime} phase. The methods described here are applicable to any evolving two-phase microstructure in which the resistance difference between the two phases is measurable.« less
Barsi, Alpar; Jager, Tjalling; Collinet, Marc; Lagadic, Laurent; Ducrot, Virginie
2014-07-01
Toxicokinetic-toxicodynamic (TKTD) modeling offers many advantages in the analysis of ecotoxicity test data. Calibration of TKTD models, however, places different demands on test design compared with classical concentration-response approaches. In the present study, useful complementary information is provided regarding test design for TKTD modeling. A case study is presented for the pond snail Lymnaea stagnalis exposed to the narcotic compound acetone, in which the data on all endpoints were analyzed together using a relatively simple TKTD model called DEBkiss. Furthermore, the influence of the data used for calibration on accuracy and precision of model parameters is discussed. The DEBkiss model described toxic effects on survival, growth, and reproduction over time well, within a single integrated analysis. Regarding the parameter estimates (e.g., no-effect concentration), precision rather than accuracy was affected depending on which data set was used for model calibration. In addition, the present study shows that the intrinsic sensitivity of snails to acetone stays the same across different life stages, including the embryonic stage. In fact, the data on egg development allowed for selection of a unique metabolic mode of action for the toxicant. Practical and theoretical considerations for test design to accommodate TKTD modeling are discussed in the hope that this information will aid other researchers to make the best possible use of their test animals. © 2014 SETAC.
Evaluation of exhaled nitric oxide in schoolchildren at different exhalation flow rates.
Pedroletti, Christophe; Zetterquist, Wilhelm; Nordvall, Lennart; Alving, Kjell
2002-09-01
Nitric oxide (NO) in exhaled air is believed to reflect allergic inflammation in the airways. Measured levels of exhaled NO vary with the exhaled flow rate, which therefore must be standardized. The aim of this study was to estimate the optimal exhalation flow rate when measuring NO in exhaled air. We studied 15 asthmatic children (8-18 y) with elevated NO levels and 15 age-matched controls and focused on how the quality of the NO curve profile, the discriminatory power, and the reproducibility were influenced by the exhalation flow rate. We used an on-line system for NO measurements at six different exhalation flow rates in the interval of 11-382 mL/s. The fraction of exhaled nitric oxide (FENO) was highly flow-dependent as was expected. Intermediate flow rates yielded a flat and stable NO plateau and were considerably easier to interpret than those obtained at the highest and lowest flow rates. The ratio of FENO between asthmatics and controls was lower at higher flow rates and a considerable overlap in NO values was demonstrated at all flow rates except 50 mL/s. The reproducibility was much lower at more extreme flow rates and was best at 50 mL/s. We conclude that a target exhalation flow rate of approximately 50 mL/s is to be preferred using the single-breath method for on-line NO measurements in schoolchildren.
Bleeding complications after endovascular therapy of cerebral arteriovenous malformations.
Heidenreich, J O; Hartlieb, S; Stendel, R; Pietilä, T A; Schlattmann, P; Wolf, K-J; Schilling, A M
2006-02-01
Intracerebral hemorrhages after embolization of arteriovenous malformations (AVMs) are the most dreaded complications of this well-established therapy. Apart from the known risk factors, our center noticed a high incidence of complications during postinterventional monitoring in medical intensive care units (ICUs) and stroke units. We report 125 consecutive interventions performed on 66 patients by using flow-dependent microcatheters and n-butyl cyanoacrylate as the embolic agent. Postinterventional intensive care monitoring was performed in an interdisciplinary operative ICU, a stroke unit, or a medical ICU. Patients were compared with regard to bleeding complications, AVM morphology, embolization result, postinterventional monitoring, and demographic factors. Intracerebral hemorrhages occurred in 7 patients. Significant differences in outcome were found between 66 patients monitored in the interdisciplinary operative ICU from medical ICU or stroke unit. This was also true when adjusted for age and extent of AVM reduction by using exact logistic regression. A partial AVM reduction of >60% was a considerable risk factor for hemorrhage (odds ratio [OR] = 18.8; 95% confidence interval [CI] [1.341, not available]. Age was also an essential risk factor. An age difference of 10 years leads to an OR of 2.545 (95% CI [1.56, 7.35]). A considerable AVM reduction in one session appears to increase the risk of hemorrhage technically. This suggests a distribution of the interventions in many partial steps.
Social and economic influences on human behavioural response in an emerging epidemic
NASA Astrophysics Data System (ADS)
Phang, P.; Wiwatanapataphee, B.; Wu, Y. H.
2017-10-01
The human behavioural changes have been recognized as an important key in shaping the disease spreading and determining the success of control measures in the course of epidemic outbreaks. However, apart from cost-benefit considerations, in reality, people are heterogeneous in their preferences towards adopting certain protective actions to reduce their risk of infection, and social norms have a function in individuals’ decision making. Here, we studied the interplay between the epidemic dynamics, imitation dynamics and the heterogeneity of individual protective behavioural response under the considerations of both economic and social factors, with a simple mathematical compartmental model and multi-population game dynamical replicator equations. We assume that susceptibles in different subpopulations have different preferences in adopting either normal or altered behaviour. By incorporating both intra- and inter-group social pressure, the outcome of the strategy distribution depends on the initial proportion of susceptible with normal and altered strategies in both subpopulations. The increase of additional cost to susceptible with altered behaviour will discourage people to take up protective actions and hence results in higher epidemic final size. For a specific cost of altered behaviour, the social group pressure could be a “double edge sword”, though. We conclude that the interplays between individual protective behaviour adoption, imitation and epidemic dynamics are necessarily complex if both economic and social factors act on populations with existing preferences.
Bajo, Miriam; Blanco, Amalio; Stavraki, Maria; Gandarillas, Beatriz; Cancela, Ana; Requero, Blanca; Díaz, Darío
2018-05-15
The effect of indirect (versus direct) exposure to a traumatic event on the quality of life of terrorist attack victims has received considerable attention in the literature. However, more research is required to examine whether the symptoms and underlying processes caused by both types of exposure are equivalent. Our main hypothesis is that well-being plays a different role depending on indirect vs. direct trauma exposure. In this cross-sectional study, eighty direct victims of 11-M terrorist attacks (people who were traveling in trains where bombs were placed) and two-hundred indirect victims (individuals highly exposed to the 11-M terrorist attacks through communications media) voluntarily participated without compensation. To test our hypothesis regarding the mediating role of indirect exposure, we conducted a biased corrected bootstrapping procedure. To test our hypothesis regarding the moderating role of direct exposure, data were subjected to a hierarchical regression analysis. As predicted, for indirect trauma exposure, well-being mediated the relationship between post-traumatic dysfunctional cognitions and trauma symptoms. However, for direct trauma exposure, well-being moderated the relationship between post-traumatic dysfunctional cognitions and trauma symptoms. The results of our study indicate that the different role of well-being found between indirect (causal factor) and direct exposure (protective factor) should be taken into consideration in interventions designed to improve victims' health.
Evolutionary game theory and criticality
NASA Astrophysics Data System (ADS)
Mahmoodi, Korosh; Grigolini, Paolo
2017-01-01
We study a regular two-dimensional network of individuals playing the Prisonner’s Dilemma game with their neighbors, assigning to each individual the adoption of two different criteria to make a choice between cooperation and defection. For a fraction q < 1 of her time the individual makes her choice by imitating those done by the nearest neighbors, with no payoff consideration. For a fraction ε =1-q the choice between cooperation and defection of an individual depends on the payoff difference between the most successful neighbor and her payoff. When q = 1 for a special value of the imitation strength K, denoted as K c, the model of social pressure generates criticality. When q = 0 a large incentive to cheat yields the extinction of cooperation and a modest one leads to the survival of cooperation. We show that for K={{K}\\text{c}} the adoption of a very small value of ɛ exerts a bias in favor of either cooperation or defection, as a form of criticality-induced intelligence, which leads the system to select either the cooperation or the defection branch, when K>{{K}\\text{c}} . Intermediate values of ɛ annihilated criticality-induced cognition and, as consequence, may favor defection choice even in the case when a wise payoff consideration is expected to yield the emergence of cooperation.
Sanches, S; Fraga, M C; Silva, N A; Nunes, P; Crespo, J G; Pereira, V J
2017-02-01
The treatment of large volumes of olive mill wastewater is presently a challenge. This study reports the technical and economical feasibility of a sequential treatment of olive mill wastewater comprising a dissolved air flotation pre-treatment and nanofiltration. Different pilot nanofiltration assays were conducted in a concentration mode up to different volume reduction factors (29, 45, 58, and 81). Data attained demonstrated that nanofiltration can be operated at considerably high volume reduction factors and still be effective towards the removal of several components. A flux decline of approximately 50% was observed at the highest volume reduction factor, mainly due to increase of the osmotic pressure. Considerably high rejections were obtained across all experiments for total suspended solids (83 to >99%), total organic carbon (64 to 99%), chemical oxygen demand (53 to 77%), and oil and grease (67 to >82%). Treated water was in compliance with European legal limits for discharge regarding total suspended solids and oil and grease. The potential recovery of phenolic compounds was evaluated and found not relevant. It was demonstrated that nanofiltration is economically feasible, involving operation costs of approximately 2.56-3.08 €/m 3 , depending on the working plan schedule and volume reduction factor, and requiring a footprint of approximately 52 m 2 to treat 1000 m 3 of olive mill wastewater.
Walter, Frank; Lam, Catherine K; van der Vegt, Gerben S; Huang, Xu; Miao, Qing
2015-07-01
Drawing from moral exclusion theory, this article examines outcome dependence and interpersonal liking as key boundary conditions for the linkage between perceived subordinate performance and abusive supervision. Moreover, it investigates the role of abusive supervision for subordinates' subsequent, objective work performance. Across 2 independent studies, an experimental scenario study (N = 157; Study 1) and a time-lagged field study (N = 169; Study 2), the negative relationship between perceived subordinate performance and abusive supervision was found to hinge on a supervisor's outcome dependence on subordinates but not on a supervisor's liking of subordinates. Furthermore, Study 2 demonstrated (a) a negative association between abusive supervision and subordinates' subsequent objective performance and (b) a conditional indirect effect of perceived performance on subsequent objective performance, through abusive supervision, contingent on the degree of outcome dependence, although these relationships did not reach conventional significance levels when controlling for prior objective performance. All in all, the findings highlight the role of instrumentality considerations in relation to abusive supervision and promote new knowledge on both origins and consequences of such supervisory behavior. (c) 2015 APA, all rights reserved).
NASA Astrophysics Data System (ADS)
Linz, Norbert; Freidank, Sebastian; Liang, Xiao-Xuan; Vogelmann, Hannes; Trickl, Thomas; Vogel, Alfred
2015-04-01
Investigation of the wavelength dependence (725-1025 nm) of the threshold for nanosecond optical breakdown in water revealed steps consistent with breakdown initiation by multiphoton ionization, with an initiation energy of about 6.6 eV. This value is considerably smaller than the autoionization threshold of about 9.5 eV, which can be regarded as band gap relevant for avalanche ionization. Breakdown initiation is likely to occur via excitation of a valence band electron into a solvated state, followed by rapid excitation into the conduction band. Theoretical analysis based on these assumptions suggests that the seed electron density required for initiating avalanche ionization amounts to 2.5 ×1015c m-3 at 725 nm and drops to 1.1 ×1012c m-3 at 1025 nm. These results demand changes of future breakdown modeling for water, including the use of a larger band gap than previously employed, the introduction of an intermediate energy level for initiation, and consideration of the wavelength dependence of seed electron density.
On double shearing in frictional materials
NASA Astrophysics Data System (ADS)
Teunissen, J. A. M.
2007-01-01
This paper evaluates the mechanical behaviour of yielding frictional geomaterials. The general Double Shearing model describes this behaviour. Non-coaxiality of stress and plastic strain increments for plane strain conditions forms an important part of this model. The model is based on a micro-mechanical and macro-mechanical formulation. The stress-dilatancy theory in the model combines the mechanical behaviour on both scales.It is shown that the general Double Shearing formulation comprises other Double Shearing models. These models differ in the relation between the mobilized friction and dilatancy and in non-coaxiality. In order to describe reversible and irreversible deformations the general Double Shearing model is extended with elasticity.The failure of soil masses is controlled by shear mechanisms. These shear mechanisms are determined by the conditions along the shear band. The shear stress ratio of a shear band depends on the orientation of the stress in the shear band. There is a difference between the peak strength and the residual strength in the shear band. While peak stress depends on strength properties only, the residual strength depends upon the yield conditions and the plastic deformation mechanisms and is generally considerably lower than the maximum strength. It is shown that non-coaxial models give non-unique solutions for the shear stress ratio on the shear band. The Double Shearing model is applied to various failure problems of soils such as the direct simple shear test, the biaxial test, infinite slopes, interfaces and for the calculation of the undrained shear strength. Copyright
Sungailaitė, Sandra; Ruzgys, Paulius; Šatkauskienė, Ingrida; Čepurnienė, Karolina; Šatkauskas, Saulius
2015-01-01
In the present study, we aimed to evaluate the efficiency of drug and gene electrotransfer into cells in vitro depending on medium viscosity. Experiments were performed using Chinese hamster ovary cells. Efficiency of molecular electrotransfer depending of medium viscosity was evaluated using two different electroporation conditions: a high-voltage (HV) pulse and a combination of a high-voltage pulse and a low-voltage pulse (HV + LV). To evaluate the efficiency of molecular electrotransfer, anticancer drug bleomycin and two different plasmids coding for green fluorescent protein and luciferase were used. We found that a slight increase in medium viscosity from 1.3-1.4 mPa·s significantly decreased the transfection efficiency, both in terms of transfected cells and total protein production, which was abolished completely with an increase in medium viscosity to 6.1 mPa·s. Notably, at this medium viscosity, electrotransfer of the small anticancer drug was still efficient. Using HV and HV + LV pulse combinations, we showed that a decrease of DNA electrotransfer, especially at lower medium viscosities, can be compensated for by the LV pulse to some extent. On the other hand, the addition of the LV pulse after the HV pulse did not have any positive effect on the efficiency of bleomycin electrotransfer. These findings demonstrate that transfection is very susceptible to medium viscosity and highlights the importance of the electrophoretic component in experiments when a considerable transfection level is needed. Copyright © 2015 John Wiley & Sons, Ltd.
Bargossi, Eleonora; Tabanelli, Giulia; Montanari, Chiara; Lanciotti, Rosalba; Gatto, Veronica; Gardini, Fausto; Torriani, Sandra
2015-01-01
The ability to accumulate tyramine and 2-phenylethylamine by two strains of Enterococcus faecalis and two strains Enterococcus faecium was evaluated in two cultural media added or not with tyrosine. All the enterococcal strains possessed a tyrosine decarboxylase (tyrDC) which determined tyramine accumulation in all the conditions tested, independently on the addition of high concentration of free tyrosine. Enterococci differed in rate and level of biogenic amines accumulation. E. faecalis EF37 and E. faecium FC12 produced tyramine in high amount since the exponential growth phase, while 2-phenylethylamine was accumulated when tyrosine was depleted. E. faecium FC12 and E. faecalis ATCC 29212 showed a slower tyraminogenic activity which took place mainly in the stationary phase up to 72 h of incubation. Moreover, E. faecalis ATCC 29212 produced 2-phenylethylamine only in the media without tyrosine added. In BHI added or not with tyrosine the tyrDC gene expression level differed considerably depending on the strains and the growth phase. In particular, the tyrDC gene expression was high during the exponential phase in rich medium for all the strains and subsequently decreased except for E. faecium FC12. Even if tyrDC presence is common among enterococci, this study underlines the extremely variable decarboxylating potential of strains belonging to the same species, suggesting strain-dependent implications in food safety.
Rescalvo, Francisco J.; Valverde-Palacios, Ignacio; Gallego, Antolino
2017-01-01
This paper offers a detailed, quantitative and exhaustive experimental comparison in terms of mechanical properties of three different layouts of carbon composite materials (CFRP) used to strengthen existing old timber beams highly affected by diverse natural defects and biological attacks, testing the use of pultruded laminate attached on the tension side of the element (LR), CFRP fabrics totally U-shape wrapping the timber element (UR), and the combined use of both reinforcement solutions (UR-P). Moreover, unidirectional and bidirectional fabrics were considered and compared. Timber elements used for the experimental program were extracted from a recent rehabilitation of the roof of the current Faculty of Law building, University of Granada (Spain), catalogued as a historical edifice. Experimental results from bending tests show that in all cases reinforcement provides a clear improvement in terms of bending capacity and stiffness as compared with the control specimens (without reinforcement). However, improvements in terms of ductility differ considerably depending on the kind of layout. PMID:28934116
Postma, Albert; Zuidhoek, Sander; Noordzij, Matthijs L; Kappers, Astrid M L
2007-01-01
The roles of visual and haptic experience in different aspects of haptic processing of objects in peripersonal space are examined. In three trials, early-blind, late-blind, and blindfolded-sighted individuals had to match ten shapes haptically to the cut-outs in a board as fast as possible. Both blind groups were much faster than the sighted in all three trials. All three groups improved considerably from trial to trial. In particular, the sighted group showed a strong improvement from the first to the second trial. While superiority of the blind remained for speeded matching after rotation of the stimulus frame, coordinate positional-memory scores in a non-speeded free-recall trial showed no significant differences between the groups. Moreover, when assessed with a verbal response, categorical spatial-memory appeared strongest in the late-blind group. The role of haptic and visual experience thus appears to depend on the task aspect tested.
DEVELOPING A VACCINE AGAINST MULTIPLE PSYCHOACTIVE TARGETS: A CASE STUDY OF HEROIN
Stowe, G. Neil; Schlosburg, Joel E.; Vendruscolo, Leandro F.; Edwards, Scott; Misra, Kaushik K.; Schulteis, Gery; Zakhari, Joseph S.; Koob, George F.; Janda, Kim D.
2012-01-01
Heroin addiction is a wide-reaching problem with a spectrum of damaging social consequences. Currently approved heroin addiction medications include drugs that bind at the same receptors (e.g. opioid receptors) occupied by heroin and/or its metabolites in the brain, but undesired side effects of these treatments, maintenance dependence and relapse to drug taking remains problematic. A vaccine capable of blocking heroin’s effects could provide an economical, long-lasting and sustainable adjunct to heroin addiction therapy without the side effects associated with available treatment options. Heroin, however, presents a particularly challenging vaccine target as it is metabolized to multiple psychoactive molecules of differing lipophilicity, with differing abilities to cross the blood brain barrier. In this review, we discuss the opiate scaffolding and hapten design considerations to confer immunogenicity as well as the specificity of the immune response towards structurally similar opiates. In addition, we detail different strategies employed in the design of immunoconjugates for a vaccine-based therapy for heroin addiction treatment. PMID:22229311
Wolfenstetter, Silke B; Schweikert, Bernd; John, Jürgen
2012-01-01
This analysis aims to discuss the implications of the "health asset concept", introduced by the WHO, and the "investment for health model" requiring a "participatory approach" of cooperative programme development applied on a physical activity programme for socially disadvantaged women and to demonstrate the related costing issues as well as the relevant decision context. The costs of programme implementation amounted to €48,700. Adding the costs for developing the programme design of €48,800 results in total costs of €97,500; adding on top of that the costs of asset assessment running to €35,600 would total €133,100. These four different cost figures match four different types of potentially relevant decisions contexts. Depending on the decision context the total costs, and hence the incremental cost-effectiveness ratio of a health promotion intervention, could differ considerably. Therefore, a detailed cost assessment and the identification of the decision context are of crucial importance.
Scale and the representation of human agency in the modeling of agroecosystems
Preston, Benjamin L.; King, Anthony W.; Ernst, Kathleen M.; ...
2015-07-17
Human agency is an essential determinant of the dynamics of agroecosystems. However, the manner in which agency is represented within different approaches to agroecosystem modeling is largely contingent on the scales of analysis and the conceptualization of the system of interest. While appropriate at times, narrow conceptualizations of agroecosystems can preclude consideration for how agency manifests at different scales, thereby marginalizing processes, feedbacks, and constraints that would otherwise affect model results. Modifications to the existing modeling toolkit may therefore enable more holistic representations of human agency. Model integration can assist with the development of multi-scale agroecosystem modeling frameworks that capturemore » different aspects of agency. In addition, expanding the use of socioeconomic scenarios and stakeholder participation can assist in explicitly defining context-dependent elements of scale and agency. Finally, such approaches, however, should be accompanied by greater recognition of the meta agency of model users and the need for more critical evaluation of model selection and application.« less
Efficient multitasking: parallel versus serial processing of multiple tasks
Fischer, Rico; Plessow, Franziska
2015-01-01
In the context of performance optimizations in multitasking, a central debate has unfolded in multitasking research around whether cognitive processes related to different tasks proceed only sequentially (one at a time), or can operate in parallel (simultaneously). This review features a discussion of theoretical considerations and empirical evidence regarding parallel versus serial task processing in multitasking. In addition, we highlight how methodological differences and theoretical conceptions determine the extent to which parallel processing in multitasking can be detected, to guide their employment in future research. Parallel and serial processing of multiple tasks are not mutually exclusive. Therefore, questions focusing exclusively on either task-processing mode are too simplified. We review empirical evidence and demonstrate that shifting between more parallel and more serial task processing critically depends on the conditions under which multiple tasks are performed. We conclude that efficient multitasking is reflected by the ability of individuals to adjust multitasking performance to environmental demands by flexibly shifting between different processing strategies of multiple task-component scheduling. PMID:26441742
Efficient multitasking: parallel versus serial processing of multiple tasks.
Fischer, Rico; Plessow, Franziska
2015-01-01
In the context of performance optimizations in multitasking, a central debate has unfolded in multitasking research around whether cognitive processes related to different tasks proceed only sequentially (one at a time), or can operate in parallel (simultaneously). This review features a discussion of theoretical considerations and empirical evidence regarding parallel versus serial task processing in multitasking. In addition, we highlight how methodological differences and theoretical conceptions determine the extent to which parallel processing in multitasking can be detected, to guide their employment in future research. Parallel and serial processing of multiple tasks are not mutually exclusive. Therefore, questions focusing exclusively on either task-processing mode are too simplified. We review empirical evidence and demonstrate that shifting between more parallel and more serial task processing critically depends on the conditions under which multiple tasks are performed. We conclude that efficient multitasking is reflected by the ability of individuals to adjust multitasking performance to environmental demands by flexibly shifting between different processing strategies of multiple task-component scheduling.
Generation of dynamo waves by spatially separated sources in the Earth and other celestial bodies
NASA Astrophysics Data System (ADS)
Popova, E.
2017-12-01
The amplitude and the spatial configuration of the planetary and stellar magnetic field can changing over the years. Celestial bodies can have cyclic, chaotic or unchanging in time magnetic activity which is connected with a dynamo mechanism. This mechanism is based on the consideration of the joint influence of the alpha-effect and differential rotation. Dynamo sources can be located at different depths (active layers) of the celestial body and can have different intensities. Application of this concept allows us to get different forms of solutions and some of which can include wave propagating inside the celestial body. We analytically showed that in the case of spatially separated sources of magnetic field each source generates a wave whose frequency depends on the physical parameters of its source. We estimated parameters of sources required for the generation nondecaying waves. We discus structure of such sources and matter motion (including meridional circulation) in the liquid outer core of the Earth and active layers of other celestial bodies.
Cobey, Kelly D; Little, Anthony C; Roberts, S Craig
2015-01-01
Here, we investigate changes in women's facial masculinity preferences across pregnancy and the post-partum period. The majority of previous research demonstrating changes in women's masculinity preferences has examined the impact of hormonal variation across the female menstrual cycle. Hormonal changes experienced during pregnancy and the post-partum period, critical periods in women's reproductive life histories, are considerably more extreme than the variation that occurs across the menstrual cycle, suggesting that differences in preferences may also be displayed during these times. We find that women's preference for masculinity in men's faces, but not women's faces, decreases in the post-partum period relative to pregnancy. Furthermore, when compared to a sample of nulliparous control participants, post-partum participants showed different masculinity preferences compared with women who were using hormonal contraception, with the direction of this difference dependent upon the sex of the face assessed. Copyright © 2014 Elsevier B.V. All rights reserved.
Rennels, Jennifer L; Langlois, Judith H
2014-10-01
Minimal research has examined children's functional use of attractiveness to classify and label others, an important step in the development of children's biases. This study compared 3- to 11-year-olds' classification, sorting, and labeling of others and themselves based on attractiveness, gender, and race and also investigated whether these abilities and other characteristics predicted children's bias and flexibility. Relative to gender and race, children rarely used attractiveness to spontaneously classify people and were less accurate at sorting and labeling others and themselves by attractiveness, suggesting that they have a less explicit concept of attractiveness. Predictors of bias differed depending on domain and assessment method (forced choice or non-forced choice), showing that children's bias is affected by both individual differences and task characteristics. Predictors of flexibility differed based on whether children were assigning positive or negative traits to target children, demonstrating that the valence of attributes is an important consideration when conceptualizing children's flexibility. Copyright © 2014 Elsevier Inc. All rights reserved.
Planar polymer and glass graded index waveguides for data center applications
NASA Astrophysics Data System (ADS)
Pitwon, Richard; Yamauchi, Akira; Brusberg, Lars; Wang, Kai; Ishigure, Takaaki; Schröder, Henning; Neitz, Marcel; Worrall, Alex
2016-03-01
Embedded optical waveguide technology for optical printed circuit boards (OPCBs) has advanced considerably over the past decade both in terms of materials and achievable waveguide structures. Two distinct classes of planar graded index multimode waveguide have recently emerged based on polymer and glass materials. We report on the suitability of graded index polymer waveguides, fabricated using the Mosquito method, and graded index glass waveguides, fabricated using ion diffusion on thin glass foils, for deployment within future data center environments as part of an optically disaggregated architecture. To this end, we first characterize the wavelength dependent performance of different waveguide types to assess their suitability with respect to two dominant emerging multimode transceiver classes based on directly modulated 850 nm VCSELs and 1310 silicon photonics devices. Furthermore we connect the different waveguide types into an optically disaggregated data storage system and characterize their performance with respect to different common high speed data protocols used at the intra and inter rack level including 10 Gb Ethernet and Serial Attached SCSI.
Bayesian inference for psychology, part IV: parameter estimation and Bayes factors.
Rouder, Jeffrey N; Haaf, Julia M; Vandekerckhove, Joachim
2018-02-01
In the psychological literature, there are two seemingly different approaches to inference: that from estimation of posterior intervals and that from Bayes factors. We provide an overview of each method and show that a salient difference is the choice of models. The two approaches as commonly practiced can be unified with a certain model specification, now popular in the statistics literature, called spike-and-slab priors. A spike-and-slab prior is a mixture of a null model, the spike, with an effect model, the slab. The estimate of the effect size here is a function of the Bayes factor, showing that estimation and model comparison can be unified. The salient difference is that common Bayes factor approaches provide for privileged consideration of theoretically useful parameter values, such as the value corresponding to the null hypothesis, while estimation approaches do not. Both approaches, either privileging the null or not, are useful depending on the goals of the analyst.
Parallel pumping of a ferromagnetic nanostripe: Confinement quantization and off-resonant driving
NASA Astrophysics Data System (ADS)
Yarbrough, P. M.; Livesey, K. L.
2018-01-01
The parametric excitation of spin waves in a rectangular, ferromagnetic nanowire in the parallel pump configuration and with an applied field along the long axis of the wire is studied theoretically, using a semi-classical and semi-analytic Hamiltonian approach. We find that as a function of static applied field strength, there are jumps in the pump power needed to excite thermal spin waves. At these jumps, there is the possibility to non-resonantly excite spin waves near kz = 0. Spin waves with negative or positive group velocity and with different standing wave structures across the wire width can be excited by tuning the applied field. By using a magnetostatic Green's function that depends on both the nanowire's width and thickness—rather than just its aspect ratio—we also find that the threshold field strength varies considerably for nanowires with the same aspect ratio but of different sizes. Comparisons between different methods of calculations are made and the advantages and disadvantages of each are discussed.
Rennels, Jennifer L.; Langlois, Judith H.
2014-01-01
Minimal research has examined children’s functional use of attractiveness to classify and label others, an important step in the development of children’s biases. This study compared 3-to 11-year-olds’ classification, sorting, and labeling of others and themselves based on attractiveness, gender, and race, and investigated whether these abilities and other characteristics predicted children’s bias and flexibility. Relative to gender and race, children rarely used attractiveness to spontaneously classify people and were less accurate at sorting and labeling others and themselves by attractiveness, suggesting they have a less explicit concept of attractiveness. Predictors of bias differed depending upon domain and assessment method (forced choice or non-forced choice), showing that children’s bias is affected by both individual differences and task characteristics. Predictors of flexibility differed based on whether children were assigning positive or negative traits to target children, demonstrating that the valence of attributes is an important consideration when conceptualizing children’s flexibility. PMID:24842583
Growth of perturbations in dark energy parametrization scenarios
NASA Astrophysics Data System (ADS)
Mehrabi, Ahmad
2018-04-01
In this paper, we study the evolution of dark matter perturbations in the linear regime by considering the possibility of dark energy perturbations. To do this, two popular parametrizations, Chevallier-Polarski-Linder (CPL) and Barboza-Alcaniz (BA), with the same number of free parameters and different redshift dependency have been considered. We integrate the full relativistic equations to obtain the growth of matter fluctuations for both clustering and smooth versions of CPL and BA dark energy. The growth rate is larger (smaller) than the Λ CDM in the smooth cases when w <-1 (w >-1 ), but the dark energy clustering gives a larger (smaller) growth index when w >-1 (w <-1 ). We measure the relative difference of the growth rate with respect to concordance Λ CDM and study how it changes depending on the free parameters. Furthermore, it is found that the difference of growth rates between smooth CPL and BA is negligible, less than 0.5%, while for the clustering case, the difference is considerable and might be as large as 2%. Eventually, using the latest geometrical and growth rate observational data, we perform an overall likelihood analysis and show that both smooth and clustering cases of CPL and BA parametrizations are consistent with observations. In particular, we find the dark energy figure of merit is approximately 70 for the BA and approximately 30 for the CPL, which indicates the BA model constrains relatively better than the CPL one.
McGann, Megan E; Bonitsky, Craig M; Ovaert, Timothy C; Wagner, Diane R
2014-06-01
Given the important role of the collagenous structure in cartilage mechanics, there is considerable interest in the relationship between collagen crosslinking and the mechanical behavior of the cartilage matrix. While crosslink-induced alterations to the elastic modulus of cartilage have been described, changes to time-dependent behavior have not yet been determined. The objective of the study was to quantify changes to cartilage material properties, including viscoelastic coefficients, with crosslinking via indentation. To accomplish this, a semi-autonomous microindentation stress relaxation protocol was first developed, validated and then applied to cartilage specimens before and after crosslinking. The change in mechanical properties with crosslinking was analyzed both in the unloading portions of the test via the Oliver-Pharr method and in the holding portion with an inverse iterative finite element model that represented cartilage as a biphasic poroviscoelastic material. Although both techniques suggested a similar increase in equilibrium modulus in the crosslinked specimens as compared to the controls, distinct differences in the control specimens were apparent, suggesting that the two different techniques may be capturing different aspects of the material behavior. No differences in time-dependent properties were observed between the crosslinked and the control specimens. These results give further insight into the effects of crosslinking in cartilage mechanical behavior. Additionally, the microindentation stress relaxation protocol may enable increased automation for high-throughput testing. Copyright © 2014 Elsevier Ltd. All rights reserved.
Bugana, Marco; Severi, Stefano; Sobie, Eric A.
2014-01-01
Reverse rate dependence is a problematic property of antiarrhythmic drugs that prolong the cardiac action potential (AP). The prolongation caused by reverse rate dependent agents is greater at slow heart rates, resulting in both reduced arrhythmia suppression at fast rates and increased arrhythmia risk at slow rates. The opposite property, forward rate dependence, would theoretically overcome these parallel problems, yet forward rate dependent (FRD) antiarrhythmics remain elusive. Moreover, there is evidence that reverse rate dependence is an intrinsic property of perturbations to the AP. We have addressed the possibility of forward rate dependence by performing a comprehensive analysis of 13 ventricular myocyte models. By simulating populations of myocytes with varying properties and analyzing population results statistically, we simultaneously predicted the rate-dependent effects of changes in multiple model parameters. An average of 40 parameters were tested in each model, and effects on AP duration were assessed at slow (0.2 Hz) and fast (2 Hz) rates. The analysis identified a variety of FRD ionic current perturbations and generated specific predictions regarding their mechanisms. For instance, an increase in L-type calcium current is FRD when this is accompanied by indirect, rate-dependent changes in slow delayed rectifier potassium current. A comparison of predictions across models identified inward rectifier potassium current and the sodium-potassium pump as the two targets most likely to produce FRD AP prolongation. Finally, a statistical analysis of results from the 13 models demonstrated that models displaying minimal rate-dependent changes in AP shape have little capacity for FRD perturbations, whereas models with large shape changes have considerable FRD potential. This can explain differences between species and between ventricular cell types. Overall, this study provides new insights, both specific and general, into the determinants of AP duration rate dependence, and illustrates a strategy for the design of potentially beneficial antiarrhythmic drugs. PMID:24675446
Cummins, Megan A; Dalal, Pavan J; Bugana, Marco; Severi, Stefano; Sobie, Eric A
2014-03-01
Reverse rate dependence is a problematic property of antiarrhythmic drugs that prolong the cardiac action potential (AP). The prolongation caused by reverse rate dependent agents is greater at slow heart rates, resulting in both reduced arrhythmia suppression at fast rates and increased arrhythmia risk at slow rates. The opposite property, forward rate dependence, would theoretically overcome these parallel problems, yet forward rate dependent (FRD) antiarrhythmics remain elusive. Moreover, there is evidence that reverse rate dependence is an intrinsic property of perturbations to the AP. We have addressed the possibility of forward rate dependence by performing a comprehensive analysis of 13 ventricular myocyte models. By simulating populations of myocytes with varying properties and analyzing population results statistically, we simultaneously predicted the rate-dependent effects of changes in multiple model parameters. An average of 40 parameters were tested in each model, and effects on AP duration were assessed at slow (0.2 Hz) and fast (2 Hz) rates. The analysis identified a variety of FRD ionic current perturbations and generated specific predictions regarding their mechanisms. For instance, an increase in L-type calcium current is FRD when this is accompanied by indirect, rate-dependent changes in slow delayed rectifier potassium current. A comparison of predictions across models identified inward rectifier potassium current and the sodium-potassium pump as the two targets most likely to produce FRD AP prolongation. Finally, a statistical analysis of results from the 13 models demonstrated that models displaying minimal rate-dependent changes in AP shape have little capacity for FRD perturbations, whereas models with large shape changes have considerable FRD potential. This can explain differences between species and between ventricular cell types. Overall, this study provides new insights, both specific and general, into the determinants of AP duration rate dependence, and illustrates a strategy for the design of potentially beneficial antiarrhythmic drugs.
Nüchtern, Elisabeth; Gansweid, Barbara; Gerber, Hans; von Mittelstaedt, Gert
2017-01-01
Objective: By the "Second Bill to Strengthen Long-Term Care", a new concept of long-term care dependency will be introduced, valid from 2017. Long-term care dependency according to Social Code XI will be defined covering more aspects than today. Therefore, the working group "Nursing Care" of the division "Social Medicine in Practice and Rehabilitation" in the German Society for Social Medicine and Prevention presents their results after working on the social medicine perspective of the definition and prevention of long-term care dependency. Methods: Both the definition and strategies to prevent long-term care dependency are systematically taken into consideration from the point of view of social medicine on the basis of the International Classification of Functioning, Disability and Health (ICF), as long-term care dependency means a defined condition of disability. Results: Both the current and the new concept of long-term care dependency focus activity limitations. The perspective of social medicine considers the interactions of health condition, its effects on daily activities and personal as well as environmental factors. From this point of view approaches for social benefits concerning prevention and rehabilitation can be identified systematically so as to work against the development and progression of long-term care dependency. The reference to the ICF can facilitate the communication between different professions. The new "graduation" of long-term care dependency would allow an international "translation" referring to the ICF. Conclusion: Experts from the field of social medicine as well as those of nursing care, care-givers and nursing researchers have in common the objective that persons in need of nursing care can participate in as many aspects of life of importance to them in an autonomous and self-determined way. The point of view of social medicine on long-term care dependency is fundamental for all occupational groups that are involved and for their successful cooperation. © Georg Thieme Verlag KG Stuttgart · New York.
Long-term leaching of photovoltaic modules
NASA Astrophysics Data System (ADS)
Nover, Jessica; Zapf-Gottwick, Renate; Feifel, Carolin; Koch, Michael; Metzger, Jörg W.; Werner, Jürgen H.
2017-08-01
Some photovoltaic module technologies use toxic materials. We report long-term leaching on photovoltaic module pieces of 5 × 5 cm2 size. The pieces are cut out from modules of the four major commercial photovoltaic technologies: crystalline and amorphous silicon, cadmium telluride as well as from copper indium gallium diselenide. To simulate different environmental conditions, leaching occurs at room temperature in three different water-based solutions with pH 3, 7, and 11. No agitation is performed to simulate more representative field conditions. After 360 days, about 1.4% of lead from crystalline silicon module pieces and 62% of cadmium from cadmium telluride module pieces are leached out in acidic solutions. The leaching depends heavily on the pH and the redox potential of the aqueous solutions and it increases with time. The leaching behavior is predictable by thermodynamic stability considerations. These predictions are in good agreement with the experimental results.
Capelli, Laura; Sironi, Selena; Rosso, Renato Del
2013-01-01
Sampling is one of the main issues pertaining to odor characterization and measurement. The aim of sampling is to obtain representative information on the typical characteristics of an odor source by means of the collection of a suitable volume fraction of the effluent. The most important information about an emission source for odor impact assessment is the so-called Odor Emission Rate (OER), which represents the quantity of odor emitted per unit of time, and is expressed in odor units per second (ou·s−1). This paper reviews the different odor sampling strategies adopted depending on source type. The review includes an overview of odor sampling regulations and a detailed discussion of the equipment to be used as well as the mathematical considerations to be applied to obtain the OER in relation to the sampled source typology. PMID:23322098
A stochastic-dynamic model for global atmospheric mass field statistics
NASA Technical Reports Server (NTRS)
Ghil, M.; Balgovind, R.; Kalnay-Rivas, E.
1981-01-01
A model that yields the spatial correlation structure of atmospheric mass field forecast errors was developed. The model is governed by the potential vorticity equation forced by random noise. Expansion in spherical harmonics and correlation function was computed analytically using the expansion coefficients. The finite difference equivalent was solved using a fast Poisson solver and the correlation function was computed using stratified sampling of the individual realization of F(omega) and hence of phi(omega). A higher order equation for gamma was derived and solved directly in finite differences by two successive applications of the fast Poisson solver. The methods were compared for accuracy and efficiency and the third method was chosen as clearly superior. The results agree well with the latitude dependence of observed atmospheric correlation data. The value of the parameter c sub o which gives the best fit to the data is close to the value expected from dynamical considerations.
Brown, Reva Berman; Adebayo, Shirley A
2004-09-01
The aims of the research were to explore the issues around the perception of District Nurses in an inner London Primary Health Care Trust of their use of work-time and leisure-time, and to reveal how the boundaries between these two aspects can become blurred and impinge on each other. Time use is helpful in considerations of wider issues such as satisfaction at work and work-life balance. The data were collected by a questionnaire to seek the views of managers and field staff on issues such as the impact on the quality of patient care of the nurses' perception of work-time and leisure-time. The research identified the different perception of "work-time" that employees have in relation to their place within the hierarchical structure. The findings answered the question of whether time is perceived differently, dependent on one's occupation within the Trust.
Rich magneto-absorption spectra of AAB-stacked trilayer graphene.
Do, Thi-Nga; Shih, Po-Hsin; Chang, Cheng-Peng; Lin, Chiun-Yan; Lin, Ming-Fa
2016-06-29
A generalized tight-binding model is developed to investigate the feature-rich magneto-optical properties of AAB-stacked trilayer graphene. Three intragroup and six intergroup inter-Landau-level (inter-LL) optical excitations largely enrich magneto-absorption peaks. In general, the former are much higher than the latter, depending on the phases and amplitudes of LL wavefunctions. The absorption spectra exhibit single- or twin-peak structures which are determined by quantum modes, LL energy spectra and Fermion distribution. The splitting LLs, with different localization centers (2/6 and 4/6 positions in a unit cell), can generate very distinct absorption spectra. There exist extra single peaks because of LL anti-crossings. AAB, AAA, ABA, and ABC stackings considerably differ from one another in terms of the inter-LL category, frequency, intensity, and structure of absorption peaks. The main characteristics of LL wavefunctions and energy spectra and the Fermi-Dirac function are responsible for the configuration-enriched magneto-optical spectra.
Comparative performance of solar thermal power generation concepts
NASA Technical Reports Server (NTRS)
Wen, L.; Wu, Y. C.
1976-01-01
A performance comparison is made between the central receiver system (power tower) and a distributed system using either dishes or troughs and lines to transport fluids to the power station. These systems were analyzed at a rated capacity of 30 MW of thermal energy delivered in the form of superheated steam at 538 C (1000 F) and 68 atm (1000 psia), using consistent weather data, collector surface waviness, pointing error, and electric conversion efficiency. The comparisons include technical considerations for component requirements, land utilization, and annual thermal energy collection rates. The relative merits of different representative systems are dependent upon the overall conversion as expressed in the form of performance factors in this paper. These factors are essentially indices of the relative performance effectiveness for different concepts based upon unit collector area. These performance factors enable further economic tradeoff studies of systems to be made by comparing them with projected production costs for these systems.
The relevance of dengue virus genotypes surveillance at country level before vaccine approval
Usme-Ciro, José A; Méndez, Jairo A; Laiton, Katherine D; Páez, Andrés
2014-01-01
Dengue is a major threat for public health in tropical and subtropical countries around the world. In the absence of a licensed vaccine and effective antiviral therapies, control measures have been based on education activities and vector elimination. Current efforts for developing a vaccine are both promising and troubling. At the advent of the introduction of a tetravalent dengue vaccine, molecular surveillance of the circulating genotypes in different geographical regions has gained considerable importance. A growing body of in vitro, preclinical, and clinical phase studies suggest that vaccine conferred protection in a geographical area could depends on the coincidence of the dengue virus genotypes included in the vaccine and those circulating. In this review we present the state-of-the-art in this field, highlighting the need of deeper knowledge on neutralizing immune response for making decisions about future vaccine approval and the potential need for different vaccine composition for regional administration. PMID:25483495
Frehmann, T; Niemann, A; Ustohal, P; Geiger, W F
2002-01-01
Four individual mathematical submodels simulating different subsystems of urban drainage were intercoupled to an integral model. The submodels (for surface runoff, flow in sewer system, wastewater treatment plant and receiving water) were calibrated on the basis of field data measured in an existing urban catchment investigation. Three different strategies for controlling the discharge in the sewer network were defined and implemented in the integral model. The impact of these control measures was quantified by representative immission state-parameters of the receiving water. The results reveal that the effect of a control measure may be ambivalent, depending on the referred component of a complex drainage system. Furthermore, it is demonstrated that the drainage system in the catchment investigation can be considerably optimised towards environmental protection and operation efficiency if an appropriate real time control on the integral scale is applied.
NASA Astrophysics Data System (ADS)
Wenzler, T.; Solanki, S. K.; Krivova, N. A.; Fluri, D. M.
2004-12-01
To be able to use both space- and ground-based solar magnetograms and construct long time series of derived parameters it is important to cross-calibrate them so that we can estimate their reliability and combine them. Using two different techniques, we compare magnetograms as well as continuum images recorded by the Spectropolarimeter (SPM) on Kitt Peak and the Michelson Doppler Interferometer (MDI) on board SoHO. We find that the result obtained depends on the method used. The method we favour gives almost identical umbral and penumbral areas and very similar total magnetic fluxes in faculae. The magnetic fluxes in umbrae and penumbrae returned by the two instruments, however, differ considerably. We also demonstrate that SPM data can be employed to reconstruct total solar irradiance variations with almost the same accuracy as recently shown for MDI data.
Capelli, Laura; Sironi, Selena; Del Rosso, Renato
2013-01-15
Sampling is one of the main issues pertaining to odor characterization and measurement. The aim of sampling is to obtain representative information on the typical characteristics of an odor source by means of the collection of a suitable volume fraction of the effluent. The most important information about an emission source for odor impact assessment is the so-called Odor Emission Rate (OER), which represents the quantity of odor emitted per unit of time, and is expressed in odor units per second (ou∙s-1). This paper reviews the different odor sampling strategies adopted depending on source type. The review includes an overview of odor sampling regulations and a detailed discussion of the equipment to be used as well as the mathematical considerations to be applied to obtain the OER in relation to the sampled source typology.
Tourist Demand Reactions: Symmetric or Asymmetric across the Business Cycle?
Bronner, Fred; de Hoog, Robert
2016-01-01
Economizing and spending priorities on different types of vacations are investigated during two periods: an economic downturn and returning prosperity. Two nation-wide samples of vacationers are used: one during a downturn, the other one at the start of the recovery period. Through comparing the results, conclusions can be drawn about symmetric or asymmetric tourist demand across the business cycle. The main summer holiday has an asymmetric profile: being fairly crisis-resistant during a recession and showing considerable growth during an expansion. This does not apply to short vacations and day trips, each having a symmetric profile: during a recession they experience substantial reductions and during expansion comparable growth. So when talking about tourist demand in general, one cannot say that it is symmetric or asymmetric across the business cycle: it depends on the type of vacation. Differences in tourist demand are best explained by the role of Quality-of-Life for vacationers. PMID:29278254
Tourist Demand Reactions: Symmetric or Asymmetric across the Business Cycle?
Bronner, Fred; de Hoog, Robert
2017-09-01
Economizing and spending priorities on different types of vacations are investigated during two periods: an economic downturn and returning prosperity. Two nation-wide samples of vacationers are used: one during a downturn, the other one at the start of the recovery period. Through comparing the results, conclusions can be drawn about symmetric or asymmetric tourist demand across the business cycle. The main summer holiday has an asymmetric profile: being fairly crisis-resistant during a recession and showing considerable growth during an expansion. This does not apply to short vacations and day trips, each having a symmetric profile: during a recession they experience substantial reductions and during expansion comparable growth. So when talking about tourist demand in general , one cannot say that it is symmetric or asymmetric across the business cycle: it depends on the type of vacation. Differences in tourist demand are best explained by the role of Quality-of-Life for vacationers.
NASA Astrophysics Data System (ADS)
Natsui, Shungo; Nashimoto, Ryota; Takai, Hifumi; Kumagai, Takehiko; Kikuchi, Tatsuya; Suzuki, Ryosuke O.
2016-06-01
The behavior of the interface between molten Sn and the LiCl-KCl eutectic melt system was observed directly. We found that the transient behavior of the interface exhibits considerable temperature dependence through a change in its physical properties. The "metal film" generated in the upper molten salt phase significantly influences the shape of the interface. Although the lifetime of the metal film depends on the gas flow rate, it is not affected by the buoyancy if the interfacial tension is dominant.
Madaleno, Mara; Moutinho, Victor
2017-04-01
This study breaks down carbon emissions into six effects within the current 28 European Union (EU) countries group, thereafter, they are divided into two different groups (the first 15 countries (EU-15) and the last 13 entering the EU (EU13)). Country-specific highlights are also examined. It analyses the evolution of the effects using a data span that runs from 1990 to 2014, to determine which of them had more impact on the intensity of emissions, while also breaking down the complete period into two distinct periods (before the Kyoto protocol (1990-2004) and after Kyoto (2005-2014)). In order to add more knowledge to the current literature, both the additive and multiplicative decomposition techniques were used to examine carbon dioxide (CO 2 ) emissions and the selected six components: carbon intensity, fossil fuel consumption, energy intensity, oil imports intensity, oil dependence, and population effect. Results point to different adapting velocities for Kyoto targets and necessary compromises. The different velocities were translated into different positive and negative impacts in the change of behavior of CO 2 emissions throughout Europe. A stress in the fluctuations in CO 2 variations before and after Kyoto and between the two different groups of EU countries could be noticed. Moreover, energy intensity and per capita dependence of oil products were identified as the major responsible components for the total and negative changes of emissions in recent years. A decrease in total changes of emissions is observed due to the fossil fuel energy consumption effect and total petroleum products effects. It is possible to infer from here that increased renewable capacity is contributing in a positive way to eco-efficiency, and should therefore be accounted for in national policymakers' decisions in the strongest way possible. Results also seem to indicate that per capita dependence of oil products has decreased, despite oil imports intensity constancy and increased renewable capacity, however, with clear heterogeneous effects, worthy of consideration when defining policies.
NASA Astrophysics Data System (ADS)
Lee, Cheoljong; Leroy, Adam K.; Schnee, Scott; Wong, Tony; Bolatto, Alberto D.; Indebetouw, Remy; Rubio, Monica
2015-07-01
To test the theoretical understanding that finding bright CO emission depends primarily on dust shielding, we investigate the relationship between CO emission (ICO) and the amount of dust (estimated from infrared emission and expressed as `AV') across the Large Magellanic Cloud (LMC), the Small Magellanic Cloud, and the Milky Way. We show that at our common resolution of 10 pc scales, ICO given a fixed line of sight AV is similar across all three systems despite the difference in metallicity. We find some evidence for a secondary dependence of ICO on radiation field; in the LMC, ICO at a given AV is smaller in regions of high Tdust, perhaps because of an increased photodissociating radiation field. We suggest a simple but useful picture in which the CO-to-H2 conversion factor (XCO) depends on two separable factors: (1) the distribution of gas column densities, which maps to an extinction distribution via a dust-to-gas ratio; and (2) the dependence of ICO on AV. Assuming that the probability distribution function (PDF) of local Milky Way clouds is universal, this approach predicts a dependence of {X_CO} on Z between Z-1 and Z-2 above about a third solar metallicity. Below this metallicity, CO emerges from only the high column density parts of the cloud and so depends very sensitively on the adopted PDF and the H2/H I prescription. The PDF of low-metallicity clouds is thus of considerable interest and the uncertainty associated with even an ideal prescription for XCO at very low metallicity will be large.
If you found mold in your household, you will want to clean it up. Some considerations on how you will clean it up depend on the size of the area, the contaminated materials, and any additional health concerns.
TS0-C142, Lithium Batteries (proposed)
DOT National Transportation Integrated Search
2000-01-01
Success in developing IVHS collision avoidance systems that are both commercially attractive and effective will depend in large part on how well product designers understand and accommodate human factors considerations in their designs. Help from the...