Statistical field theory of futures commodity prices
NASA Astrophysics Data System (ADS)
Baaquie, Belal E.; Yu, Miao
2018-02-01
The statistical theory of commodity prices has been formulated by Baaquie (2013). Further empirical studies of single (Baaquie et al., 2015) and multiple commodity prices (Baaquie et al., 2016) have provided strong evidence in support the primary assumptions of the statistical formulation. In this paper, the model for spot prices (Baaquie, 2013) is extended to model futures commodity prices using a statistical field theory of futures commodity prices. The futures prices are modeled as a two dimensional statistical field and a nonlinear Lagrangian is postulated. Empirical studies provide clear evidence in support of the model, with many nontrivial features of the model finding unexpected support from market data.
ERIC Educational Resources Information Center
Williams, Amanda
2014-01-01
The purpose of the current research was to investigate the relationship between preference for numerical information (PNI), math self-concept, and six types of statistics anxiety in an attempt to establish support for the nomological validity of the PNI. Correlations indicate that four types of statistics anxiety were strongly related to PNI, and…
Tuning the photon statistics of a strongly coupled nanophotonic system
NASA Astrophysics Data System (ADS)
Dory, Constantin; Fischer, Kevin A.; Müller, Kai; Lagoudakis, Konstantinos G.; Sarmiento, Tomas; Rundquist, Armand; Zhang, Jingyuan L.; Kelaita, Yousif; Sapra, Neil V.; Vučković, Jelena
2017-02-01
We investigate the dynamics of single- and multiphoton emission from detuned strongly coupled systems based on the quantum-dot-photonic-crystal resonator platform. Transmitting light through such systems can generate a range of nonclassical states of light with tunable photon counting statistics due to the nonlinear ladder of hybridized light-matter states. By controlling the detuning between emitter and resonator, the transmission can be tuned to strongly enhance either single- or two-photon emission processes. Despite the strongly dissipative nature of these systems, we find that by utilizing a self-homodyne interference technique combined with frequency filtering we are able to find a strong two-photon component of the emission in the multiphoton regime. In order to explain our correlation measurements, we propose rate equation models that capture the dominant processes of emission in both the single- and multiphoton regimes. These models are then supported by quantum-optical simulations that fully capture the frequency filtering of emission from our solid-state system.
Do Structural Equity Issues in Middle Schools Lead to Achievement Disparities?
ERIC Educational Resources Information Center
Wolf, Chyrese S.
2012-01-01
Striking statistically significant differences were noted across school ranking conditions in terms of professional teacher preparation, organizational health variables, school leadership characteristics, academic emphasis, and resource support. The general conclusion of this study is that a strong correlation exists between structural equity…
Torres-Carvajal, Omar; Schulte, James A; Cadle, John E
2006-04-01
The South American iguanian lizard genus Stenocercus includes 54 species occurring mostly in the Andes and adjacent lowland areas from northern Venezuela and Colombia to central Argentina at elevations of 0-4000m. Small taxon or character sampling has characterized all phylogenetic analyses of Stenocercus, which has long been recognized as sister taxon to the Tropidurus Group. In this study, we use mtDNA sequence data to perform phylogenetic analyses that include 32 species of Stenocercus and 12 outgroup taxa. Monophyly of this genus is strongly supported by maximum parsimony and Bayesian analyses. Evolutionary relationships within Stenocercus are further analyzed with a Bayesian implementation of a general mixture model, which accommodates variability in the pattern of evolution across sites. These analyses indicate a basal split of Stenocercus into two clades, one of which receives very strong statistical support. In addition, we test previous hypotheses using non-parametric and parametric statistical methods, and provide a phylogenetic classification for Stenocercus.
Katsiaficas, Dalal; Volpe, Vanessa; Raza, Syeda S; Garcia, Yuliana
2017-08-30
This study examined civic engagement in a sample of 790 undocumented Latinx undergraduates (aged 18-30). The relations between social supports (campus safe spaces and peer support) and civic engagement and whether a strong sense of undocumented identity mediated this relation were examined. Competing statistical models examined the role of participants' status (whether or not they received temporary protection from deportation with Deferred Action for Childhood Arrivals [DACA]) in this mediational process. Results revealed that having a strong identification with being undocumented mediated the role of social supports on civic engagement in the overall sample, and that this process was specifically important for those with DACA status. The intersection of policies such as DACA and the lived experiences of Latinx undocumented college students are discussed. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.
Let's Keep Our Quality School Principals on the Job
ERIC Educational Resources Information Center
Norton, M. Scott
2003-01-01
Research studies strongly support the fact that the leadership of the school principal impacts directly on the climate of the school and, in turn, on student achievement. National statistics relating to principal turnover and dwindling supplies of qualified replacements show clearly that principal turnover has reached crisis proportions.…
Social networks, social support, and mortality among older people in Japan.
Sugisawa, H; Liang, J; Liu, X
1994-01-01
This study examined the effects of social networks and social support on the mortality of a national probability sample of 2,200 elderly Japanese persons during a three-year period. The direct and indirect effects of social relationships were assessed by using hazard rate models in conjunction with ordinary least squares regressions. Among the five measures of social relationships, social participation is shown to have a strong impact on mortality, and this effect remains statistically significant when other factors are considered. Social participation, social support, and feelings of loneliness are found to have indirect effects on the mortality of the Japanese elders through their linkages with chronic diseases, functional status, and self-rated health. On the other hand, marital status and social contacts are not shown to have statistically significant effects on the risk of dying, either directly or indirectly.
Statistical evidence for common ancestry: Application to primates.
Baum, David A; Ané, Cécile; Larget, Bret; Solís-Lemus, Claudia; Ho, Lam Si Tung; Boone, Peggy; Drummond, Chloe P; Bontrager, Martin; Hunter, Steven J; Saucier, William
2016-06-01
Since Darwin, biologists have come to recognize that the theory of descent from common ancestry (CA) is very well supported by diverse lines of evidence. However, while the qualitative evidence is overwhelming, we also need formal methods for quantifying the evidential support for CA over the alternative hypothesis of separate ancestry (SA). In this article, we explore a diversity of statistical methods using data from the primates. We focus on two alternatives to CA, species SA (the separate origin of each named species) and family SA (the separate origin of each family). We implemented statistical tests based on morphological, molecular, and biogeographic data and developed two new methods: one that tests for phylogenetic autocorrelation while correcting for variation due to confounding ecological traits and a method for examining whether fossil taxa have fewer derived differences than living taxa. We overwhelmingly rejected both species and family SA with infinitesimal P values. We compare these results with those from two companion papers, which also found tremendously strong support for the CA of all primates, and discuss future directions and general philosophical issues that pertain to statistical testing of historical hypotheses such as CA. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.
Multiple commodities in statistical microeconomics: Model and market
NASA Astrophysics Data System (ADS)
Baaquie, Belal E.; Yu, Miao; Du, Xin
2016-11-01
A statistical generalization of microeconomics has been made in Baaquie (2013). In Baaquie et al. (2015), the market behavior of single commodities was analyzed and it was shown that market data provides strong support for the statistical microeconomic description of commodity prices. The case of multiple commodities is studied and a parsimonious generalization of the single commodity model is made for the multiple commodities case. Market data shows that the generalization can accurately model the simultaneous correlation functions of up to four commodities. To accurately model five or more commodities, further terms have to be included in the model. This study shows that the statistical microeconomics approach is a comprehensive and complete formulation of microeconomics, and which is independent to the mainstream formulation of microeconomics.
An Overview of Interrater Agreement on Likert Scales for Researchers and Practitioners
O'Neill, Thomas A.
2017-01-01
Applications of interrater agreement (IRA) statistics for Likert scales are plentiful in research and practice. IRA may be implicated in job analysis, performance appraisal, panel interviews, and any other approach to gathering systematic observations. Any rating system involving subject-matter experts can also benefit from IRA as a measure of consensus. Further, IRA is fundamental to aggregation in multilevel research, which is becoming increasingly common in order to address nesting. Although, several technical descriptions of a few specific IRA statistics exist, this paper aims to provide a tractable orientation to common IRA indices to support application. The introductory overview is written with the intent of facilitating contrasts among IRA statistics by critically reviewing equations, interpretations, strengths, and weaknesses. Statistics considered include rwg, rwg*, r′wg, rwg(p), average deviation (AD), awg, standard deviation (Swg), and the coefficient of variation (CVwg). Equations support quick calculation and contrasting of different agreement indices. The article also includes a “quick reference” table and three figures in order to help readers identify how IRA statistics differ and how interpretations of IRA will depend strongly on the statistic employed. A brief consideration of recommended practices involving statistical and practical cutoff standards is presented, and conclusions are offered in light of the current literature. PMID:28553257
Inter-annual rainfall variations and suicide in New South Wales, Australia, 1964-2001
NASA Astrophysics Data System (ADS)
Nicholls, Neville; Butler, Colin D.; Hanigan, Ivan
2006-01-01
The suicide rate in New South Wales is shown to be related to annual precipitation, supporting a widespread and long-held assumption that drought in Australia increases the likelihood of suicide. The relationship, although statistically significant, is not especially strong and is confounded by strong, long-term variations in the suicide rate not related to precipitation variations. A decrease in precipitation of about 300 mm would lead to an increase in the suicide rate of approximately 8% of the long-term mean suicide rate.
Newark Kids Count 2004: A City Profile of Child Well-Being
ERIC Educational Resources Information Center
Association for Children of New Jersey, 2004
2004-01-01
"Newark Kids Count 2004" presents a statistical snapshot of child well-being that can be used to inform those efforts to create a strong community safety net for Newark's youngest citizens. Following is a look at some of the major trends documented in this year's report: (1) Poverty persists; (2) Nutritional supports lag; (3) Unmarried…
NASA Astrophysics Data System (ADS)
Sun, Yong; Ding, Zhao-Hua; Xiao, Jing-Lin
2017-03-01
Employing variational method of Pekar type (VMPT), this paper investigates the first-excited state energy (FESE), excitation energy and transition frequency of the strongly-coupled polaron in the CsI quantum pseudodot (QPD) with electric field. The temperature effects on the strong-coupling polaron in electric field are calculated by using the quantum statistical theory (QST). The results from the present investigation show that the FESE, excitation energy and transition frequency increase (decrease) firstly and then at lower (higher) temperature regions. They are decreasing functions of the electric field strength. Supported by the National Natural Science Foundation of China under Grant No. 11464033
Tuning the Photon Statistics of a Strongly Coupled Nanophotonic System
NASA Astrophysics Data System (ADS)
Dory, C.; Fischer, K. A.; Müller, K.; Lagoudakis, K. G.; Sarmiento, T.; Rundquist, A.; Zhang, J. L.; Kelaita, Y.; Sapra, N. V.; Vučković, J.
Strongly coupled quantum-dot-photonic-crystal cavity systems provide a nonlinear ladder of hybridized light-matter states, which are a promising platform for non-classical light generation. The transmission of light through such systems enables light generation with tunable photon counting statistics. By detuning the frequencies of quantum emitter and cavity, we can tune the transmission of light to strongly enhance either single- or two-photon emission processes. However, these nanophotonic systems show a strongly dissipative nature and classical light obscures any quantum character of the emission. In this work, we utilize a self-homodyne interference technique combined with frequency-filtering to overcome this obstacle. This allows us to generate emission with a strong two-photon component in the multi-photon regime, where we measure a second-order coherence value of g (2) [ 0 ] = 1 . 490 +/- 0 . 034 . We propose rate equation models that capture the dominant processes of emission both in the single- and multi-photon regimes and support them by quantum-optical simulations that fully capture the frequency filtering of emission from our solid-state system. Finally, we simulate a third-order coherence value of g (3) [ 0 ] = 0 . 872 +/- 0 . 021 . Army Research Office (ARO) (W911NF1310309), National Science Foundation (1503759), Stanford Graduate Fellowship.
ERIC Educational Resources Information Center
Oderman, Dale
2003-01-01
Part Two B of a three-part study examined how 40 universities with baccalaureate programs in aviation management include ethics education in the curricula. Analysis of responses suggests that there is strong support for ethics instruction and that active department head involvement leads to higher levels of planned ethics inclusion. (JOW)
Magnetic holes in the dipolarized magnetotail: ion and electron anisotropies
NASA Astrophysics Data System (ADS)
Shustov, P.; Artemyev, A.; Zhang, X. J.; Yushkov, E.; Petrukovich, A. A.
2017-12-01
We conduct statistics on magnetic holes observed by THEMIS spacecraft in the near-Earth magnetotail. Groups of holes are detected after dipolarizations in the quiet, equatorial plasma sheet. Magnetic holes are characterized by significant magnetic field depressions (up to 50%) and strong electron currents ( 10-50 nA/m2), with spatial scales much smaller than the ion gyroradius. These magnetic holes are populated by hot (>10 keV), transversely anisotropic electrons supporting the pressure balance. We present statistical properties of these sub-ion scale magnetic holes and discuss possible mechanisms on the hole formation.
[The development of hospital medical supplies information management system].
Cao, Shaoping; Gu, Hongqing; Zhang, Peng; Wang, Qiang
2010-05-01
The information management of medical materials by using high-tech computer, in order to improve the efficiency of the consumption of medical supplies, hospital supplies and develop a new technology way to manage the hospital and material support. Using C # NET, JAVA techniques to develop procedures for the establishment of hospital material management information system, set the various management modules, production of various statistical reports, standard operating procedures. The system is convenient, functional and strong, fluent statistical functions. It can always fully grasp and understand the whole hospital supplies run dynamic information, as a modern and effective tool for hospital materials management.
Theory of atomic spectral emission intensity
NASA Astrophysics Data System (ADS)
Yngström, Sten
1994-07-01
The theoretical derivation of a new spectral line intensity formula for atomic radiative emission is presented. The theory is based on first principles of quantum physics, electrodynamics, and statistical physics. Quantum rules lead to revision of the conventional principle of local thermal equilibrium of matter and radiation. Study of electrodynamics suggests absence of spectral emission from fractions of the numbers of atoms and ions in a plasma due to radiative inhibition caused by electromagnetic force fields. Statistical probability methods are extended by the statement: A macroscopic physical system develops in the most probable of all conceivable ways consistent with the constraining conditions for the system. The crucial role of statistical physics in transforming quantum logic into common sense logic is stressed. The theory is strongly supported by experimental evidence.
ERIC Educational Resources Information Center
Holtzapple, Carol K.
2011-01-01
Character education programs support the development of positive character traits in children and adults. Effective violence prevention programs improve pro-social competencies and reduce negative behaviors in students by enhancing protective factors (strong bonds with teachers; clear rules of conduct that are consistently enforced) and targeting…
The Effect of Multispectral Image Fusion Enhancement on Human Efficiency
2017-03-20
performance of the ideal observer is indicative of the relative amount of informa- tion across various experimental manipulations. In our experimental design ...registration and fusion processes, and contributed strongly to the statistical analyses. LMB contributed to the experimental design and writing structure. All... designed to be innovative, low-cost, and (relatively) easy-to-implement, and to provide support across the spectrum of possible users including
The Effects of Geographic Isolation and Social Support on the Health of Wisconsin Women.
Tittman, Sarah M; Harteau, Christy; Beyer, Kirsten M M
2016-04-01
Rural residents are less likely to receive preventive health screening, more likely to be uninsured, and more likely to report fair to poor health than urban residents. Social disconnectedness and perceived isolation are known to be negative predictors of self-rated physical health; however, the direct effects of geographic isolation and social support on overall health have not been well elucidated. A cross-sectional survey of women (n = 113) participating in Wisconsin Rural Women's initiative programming was conducted, which included measures of geographic isolation, an assessment of overall health, and social support using the validated Interpersonal Support Evaluation List with 3 subscales, including belonging support, tangible support, and appraisal support. Geographic isolation was shown to be a negative predictor of belonging support (P = .0064) and tangible support (P = .0349); however, geographic isolation was not a statistically significant predictor of appraisal support. A strong and direct relationship was observed between social support and self-perceived health status among this population of Wisconsin women, and hospital access based on geographic proximity was positively correlated (P = .028) with overall health status. The direct relationship between social support and overall health demonstrated here stresses the importance of developing and maintaining strong social support networks, which can be improved through rural support groups that have the unique ability to assist rural residents in fostering social support systems, advocating stress management techniques, and achieving a greater sense of well-being.
Optimization of Multilocus Sequence Analysis for Identification of Species in the Genus Vibrio
Gabriel, Michael W.; Matsui, George Y.; Friedman, Robert
2014-01-01
Multilocus sequence analysis (MLSA) is an important method for identification of taxa that are not well differentiated by 16S rRNA gene sequences alone. In this procedure, concatenated sequences of selected genes are constructed and then analyzed. The effects that the number and the order of genes used in MLSA have on reconstruction of phylogenetic relationships were examined. The recA, rpoA, gapA, 16S rRNA gene, gyrB, and ftsZ sequences from 56 species of the genus Vibrio were used to construct molecular phylogenies, and these were evaluated individually and using various gene combinations. Phylogenies from two-gene sequences employing recA and rpoA in both possible gene orders were different. The addition of the gapA gene sequence, producing all six possible concatenated sequences, reduced the differences in phylogenies to degrees of statistical (bootstrap) support for some nodes. The overall statistical support for the phylogenetic tree, assayed on the basis of a reliability score (calculated from the number of nodes having bootstrap values of ≥80 divided by the total number of nodes) increased with increasing numbers of genes used, up to a maximum of four. No further improvement was observed from addition of the fifth gene sequence (ftsZ), and addition of the sixth gene (gyrB) resulted in lower proportions of strongly supported nodes. Reductions in the numbers of strongly supported nodes were also observed when maximum parsimony was employed for tree construction. Use of a small number of gene sequences in MLSA resulted in accurate identification of Vibrio species. PMID:24951781
Family support in cancer survivorship.
Muhamad, Mazanah; Afshari, Mojgan; Kazilan, Fitrisehara
2011-01-01
This paper raises issues about the role of family members in providing support for breast cancer survivors. Data were collected from 400 breast cancer survivors in Peninsular Malaysia through a custom-designed questionnaire fielded at hospitals and support group meetings. The data were analyzed using descriptive statistics. The analyses show that all family members could be supportive, especially in decision making and help with emotional issues. The spouse was the main support provider among the family members (others were children, parents, siblings and more distant relatives). The results also indicated that a significant percentage practiced collaborative decision-making. Breast cancer survivors needed their family members' support for information on survivorship strategies such as managing emotions, health, life style and dietary practice. The family members' supportive role may be linked to the Malaysian strong family relationship culture. For family members to contribute more adequately to cancer survivorship, it is suggested that appropriate educational intervention also be provided to them.
Signatures of Fractional Exclusion Statistics in the Spectroscopy of Quantum Hall Droplets
NASA Astrophysics Data System (ADS)
Cooper, Nigel
2015-05-01
One of the most dramatic features of strongly correlated phases is the emergence of quasiparticle excitations with unconventional quantum statistics. The archetypal example is the fractional, ``anyonic,'' quantum statistics predicted for quasiparticles of the fractional quantum Hall phases. While experiments on semiconductor devices have shown that these quasiparticles have fractional charges, a direct observation of the fractional statistics has remained lacking. In this talk I shall show how precision spectroscopy measurements of rotating droplets of ultracold atoms might be used to demonstrate the Haldane fractional exclusion statistics of quasiholes in the Laughlin state of bosons. The characteristic signatures appear in the single-particle excitation spectrum. I shall show that the transitions are governed by a ``many-body selection rule'' which allows one to relate the number of allowed transitions to the number of quasihole states. I shall illustrate the theory with numerically exact simulations of small numbers of particles. Work in collaboration with Steven H. Simon, and supported by the EPSRC and the Royal Society.
Brown, C; Burslem, D F R P; Illian, J B; Bao, L; Brockelman, W; Cao, M; Chang, L W; Dattaraja, H S; Davies, S; Gunatilleke, C V S; Gunatilleke, I A U N; Huang, J; Kassim, A R; Lafrankie, J V; Lian, J; Lin, L; Ma, K; Mi, X; Nathalang, A; Noor, S; Ong, P; Sukumar, R; Su, S H; Sun, I F; Suresh, H S; Tan, S; Thompson, J; Uriarte, M; Valencia, R; Yap, S L; Ye, W; Law, R
2013-08-07
Neutral and niche theories give contrasting explanations for the maintenance of tropical tree species diversity. Both have some empirical support, but methods to disentangle their effects have not yet been developed. We applied a statistical measure of spatial structure to data from 14 large tropical forest plots to test a prediction of niche theory that is incompatible with neutral theory: that species in heterogeneous environments should separate out in space according to their niche preferences. We chose plots across a range of topographic heterogeneity, and tested whether pairwise spatial associations among species were more variable in more heterogeneous sites. We found strong support for this prediction, based on a strong positive relationship between variance in the spatial structure of species pairs and topographic heterogeneity across sites. We interpret this pattern as evidence of pervasive niche differentiation, which increases in importance with increasing environmental heterogeneity.
Sanne, Bjarte; Mykletun, Arnstein; Dahl, Alv A; Moen, Bente E; Tell, Grethe S
2005-09-01
To test the strain/iso-strain, interaction and buffer hypotheses of the Job Demand-Control-Support model in relation to anxiety and depression. Five thousand five hundred and sixty-two workers with valid Demand-Control-Support Questionnaire (DCSQ) scores were examined with the sub-scales of the Hospital Anxiety and Depression Scale as outcomes. Multiple statistical methods were applied. The strain and iso-strain hypotheses were confirmed. Generally, additive and non-interaction effects were found between psychological demands, control and social support. The buffer hypotheses were refuted. Results from analyses testing different interaction operationalizations were complementary. High demands, low control and low support individually, but particularly combined, are risk factors for anxiety and depression. Support is the DCSQ index most strongly associated with anxiety and depression in women. Assessment of psychosocial work environment may identify workers at risk, and serve as a basis for job-redesign.
Hailer, Frank; Kutschera, Verena E; Hallström, Björn M; Fain, Steven R; Leonard, Jennifer A; Arnason, Ulfur; Janke, Axel
2013-03-29
Nakagome et al. reanalyzed some of our data and assert that we cannot refute the mitochondrial DNA-based scenario for polar bear evolution. Their single-locus test statistic is strongly affected by introgression and incomplete lineage sorting, whereas our multilocus approaches are better suited to recover the true species relationships. Indeed, our sister-lineage model receives high support in a Bayesian model comparison.
Superposed epoch analysis of physiological fluctuations: possible space weather connections
NASA Astrophysics Data System (ADS)
Wanliss, James; Cornélissen, Germaine; Halberg, Franz; Brown, Denzel; Washington, Brien
2018-03-01
There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events—space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.
Superposed epoch analysis of physiological fluctuations: possible space weather connections.
Wanliss, James; Cornélissen, Germaine; Halberg, Franz; Brown, Denzel; Washington, Brien
2018-03-01
There is a strong connection between space weather and fluctuations in technological systems. Some studies also suggest a statistical connection between space weather and subsequent fluctuations in the physiology of living creatures. This connection, however, has remained controversial and difficult to demonstrate. Here we present support for a response of human physiology to forcing from the explosive onset of the largest of space weather events-space storms. We consider a case study with over 16 years of high temporal resolution measurements of human blood pressure (systolic, diastolic) and heart rate variability to search for associations with space weather. We find no statistically significant change in human blood pressure but a statistically significant drop in heart rate during the main phase of space storms. Our empirical findings shed light on how human physiology may respond to exogenous space weather forcing.
Miller, Shari; Williams, Jason; Cutbush, Stacey; Gibbs, Deborah; Clinton-Sherrod, Monique; Jones, Sarah
2015-02-01
This study reports on an independent evaluation of Start Strong: Building Healthy Teen Relationships, a multicomponent initiative targeting 11- to 14-year-olds. "Start Strong" was designed to focus on the developmental needs of middle school students and to enhance skills and attitudes consistent with promotion of healthy relationships and reduction of teen dating violence (TDV). The quasi-experimental evaluation design included data collection from four Start Strong schools and four comparison schools. Student surveys were collected at four waves of data at the beginning and the end of grades 7 and 8. Multilevel models used repeated observations nested within students who were, in turn, nested within schools to determine whether participation in Start Strong enhanced healthy skills and relationships and decreased TDV-related attitudes and behaviors. Short-term effects from waves 1 to 2 were statistically significant for increased parent-child communication and boy/girlfriend relationship satisfaction and support and decreased gender stereotypes and attitudes supporting TDV. Findings for acceptance of TDV and gender stereotypes persisted longitudinally. Results are promising and illustrate that a multicomponent, community-based initiative reduced risk factors predictive of TDV. Start Strong is innovative in its focus on early adolescence, which is a critical period in the transition to dating. The results inform future intervention efforts and underscore the need for further study of middle school students. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.
2013-01-01
Background Population studies on end-of-life decisions have not been conducted in Cyprus. Our study aim was to evaluate the beliefs and attitudes of Greek Cypriots towards end-of-life issues regarding euthanasia and cremation. Methods A population-based telephone survey was conducted in Cyprus. One thousand randomly selected individuals from the population of Cyprus age 20 years or older were invited to participate. Beliefs and attitudes on end-of-life decisions were collected using an anonymous and validated questionnaire. Statistical analyses included cross-tabulations, Pearson’s chi-square tests and multivariable-adjusted logistic regression models. Results A total of 308 males and 689 females participated in the survey. About 70% of the respondents did not support euthanasia for people with incurable illness and/or elders with dementia when requested by them and 77% did not support euthanasia for people with incurable illness and/or elders with dementia when requested by relatives. Regarding cremation, 78% were against and only 14% reported being in favor. Further statistical analyses showed that male gender, being single and having reached higher educational level were factors positively associated with support for euthanasia in a statistically significant fashion. On the contrary, the more religiosity expressed by study participants, the less support they reported for euthanasia or cremation. Conclusions The vast majority of Greek Cypriots does not support euthanasia for people with incurable illness and/or elders with dementia and also do not support cremation. Certain demographic characteristics such as age and education have a positive influence towards attitudes for euthanasia and cremation, while religiosity exerts a strong negative influence on the above. Family bonding as well as social and cultural traditions may also play a role although not comprehensively evaluated in the current study. PMID:24060291
Televantos, Anastasios; Talias, Michael A; Charalambous, Marianna; Soteriades, Elpidoforos S
2013-09-23
Population studies on end-of-life decisions have not been conducted in Cyprus. Our study aim was to evaluate the beliefs and attitudes of Greek Cypriots towards end-of-life issues regarding euthanasia and cremation. A population-based telephone survey was conducted in Cyprus. One thousand randomly selected individuals from the population of Cyprus age 20 years or older were invited to participate. Beliefs and attitudes on end-of-life decisions were collected using an anonymous and validated questionnaire. Statistical analyses included cross-tabulations, Pearson's chi-square tests and multivariable-adjusted logistic regression models. A total of 308 males and 689 females participated in the survey. About 70% of the respondents did not support euthanasia for people with incurable illness and/or elders with dementia when requested by them and 77% did not support euthanasia for people with incurable illness and/or elders with dementia when requested by relatives. Regarding cremation, 78% were against and only 14% reported being in favor. Further statistical analyses showed that male gender, being single and having reached higher educational level were factors positively associated with support for euthanasia in a statistically significant fashion. On the contrary, the more religiosity expressed by study participants, the less support they reported for euthanasia or cremation. The vast majority of Greek Cypriots does not support euthanasia for people with incurable illness and/or elders with dementia and also do not support cremation. Certain demographic characteristics such as age and education have a positive influence towards attitudes for euthanasia and cremation, while religiosity exerts a strong negative influence on the above. Family bonding as well as social and cultural traditions may also play a role although not comprehensively evaluated in the current study.
Δim-lacunary statistical convergence of order α
NASA Astrophysics Data System (ADS)
Altınok, Hıfsı; Et, Mikail; Işık, Mahmut
2018-01-01
The purpose of this work is to introduce the concepts of Δim-lacunary statistical convergence of order α and lacunary strongly (Δim,p )-convergence of order α. We establish some connections between lacunary strongly (Δim,p )-convergence of order α and Δim-lacunary statistical convergence of order α. It is shown that if a sequence is lacunary strongly (Δim,p )-summable of order α then it is Δim-lacunary statistically convergent of order α.
Hill, Terrence D.; Uchino, Bert N.; Eckhardt, Jessica L.; Angel, Jacqueline L.
2016-01-01
Although numerous studies of non-Hispanic whites and blacks show that social integration and social support tend to favor longevity, it is unclear whether this general pattern extends to the Mexican American population. Building on previous research, we employed seven waves of data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly to examine the association between perceived social support trajectories and the all-cause mortality risk of older Mexican Americans. Growth mixture estimates revealed three latent classes of support trajectories: high, moderate, and low. Cox regression estimates indicated that older Mexican American men in the low support trajectory tend to exhibit a higher mortality risk than their counterparts in the high support trajectory. Social support trajectories were unrelated to the mortality risk of older Mexican American women. A statistically significant interaction term confirmed that social support was more strongly associated with the mortality risk of men. PMID:26966256
Hill, Terrence D; Uchino, Bert N; Eckhardt, Jessica L; Angel, Jacqueline L
2016-04-01
Although numerous studies of non-Hispanic Whites and Blacks show that social integration and social support tend to favor longevity, it is unclear whether this general pattern extends to the Mexican American population. Building on previous research, we employed seven waves of data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly to examine the association between perceived social support trajectories and the all-cause mortality risk of older Mexican Americans. Growth mixture estimates revealed three latent classes of support trajectories: high, moderate, and low. Cox regression estimates indicated that older Mexican American men in the low support trajectory tend to exhibit a higher mortality risk than their counterparts in the high support trajectory. Social support trajectories were unrelated to the mortality risk of older Mexican American women. A statistically significant interaction term confirmed that social support was more strongly associated with the mortality risk of men. © The Author(s) 2015.
Statistical testing of the full-range leadership theory in nursing.
Kanste, Outi; Kääriäinen, Maria; Kyngäs, Helvi
2009-12-01
The aim of this study is to test statistically the structure of the full-range leadership theory in nursing. The data were gathered by postal questionnaires from nurses and nurse leaders working in healthcare organizations in Finland. A follow-up study was performed 1 year later. The sample consisted of 601 nurses and nurse leaders, and the follow-up study had 78 respondents. Theory was tested through structural equation modelling, standard regression analysis and two-way anova. Rewarding transformational leadership seems to promote and passive laissez-faire leadership to reduce willingness to exert extra effort, perceptions of leader effectiveness and satisfaction with the leader. Active management-by-exception seems to reduce willingness to exert extra effort and perception of leader effectiveness. Rewarding transformational leadership remained as a strong explanatory factor of all outcome variables measured 1 year later. The data supported the main structure of the full-range leadership theory, lending support to the universal nature of the theory.
Spectral statistics and scattering resonances of complex primes arrays
NASA Astrophysics Data System (ADS)
Wang, Ren; Pinheiro, Felipe A.; Dal Negro, Luca
2018-01-01
We introduce a class of aperiodic arrays of electric dipoles generated from the distribution of prime numbers in complex quadratic fields (Eisenstein and Gaussian primes) as well as quaternion primes (Hurwitz and Lifschitz primes), and study the nature of their scattering resonances using the vectorial Green's matrix method. In these systems we demonstrate several distinctive spectral properties, such as the absence of level repulsion in the strongly scattering regime, critical statistics of level spacings, and the existence of critical modes, which are extended fractal modes with long lifetimes not supported by either random or periodic systems. Moreover, we show that one can predict important physical properties, such as the existence spectral gaps, by analyzing the eigenvalue distribution of the Green's matrix of the arrays in the complex plane. Our results unveil the importance of aperiodic correlations in prime number arrays for the engineering of gapped photonic media that support far richer mode localization and spectral properties compared to usual periodic and random media.
Influences of Atmospheric Stability State on Wind Turbine Aerodynamic Loadings
NASA Astrophysics Data System (ADS)
Vijayakumar, Ganesh; Lavely, Adam; Brasseur, James; Paterson, Eric; Kinzel, Michael
2011-11-01
Wind turbine power and loadings are influenced by the structure of atmospheric turbulence and thus on the stability state of the atmosphere. Statistical differences in loadings with atmospheric stability could impact controls, blade design, etc. Large-eddy simulation (LES) of the neutral and moderately convective atmospheric boundary layer (NBL, MCBL) are used as inflow to the NREL FAST advanced blade-element momentum theory code to predict wind turbine rotor power, sectional lift and drag, blade bending moments and shaft torque. Using horizontal homogeneity, we combine time and ensemble averages to obtain converged statistics equivalent to ``infinite'' time averages over a single turbine. The MCBL required longer effective time periods to obtain converged statistics than the NBL. Variances and correlation coefficients among wind velocities, turbine power and blade loadings were higher in the MCBL than the NBL. We conclude that the stability state of the ABL strongly influences wind turbine performance. Supported by NSF and DOE.
A statistical framework for evaluating neural networks to predict recurrent events in breast cancer
NASA Astrophysics Data System (ADS)
Gorunescu, Florin; Gorunescu, Marina; El-Darzi, Elia; Gorunescu, Smaranda
2010-07-01
Breast cancer is the second leading cause of cancer deaths in women today. Sometimes, breast cancer can return after primary treatment. A medical diagnosis of recurrent cancer is often a more challenging task than the initial one. In this paper, we investigate the potential contribution of neural networks (NNs) to support health professionals in diagnosing such events. The NN algorithms are tested and applied to two different datasets. An extensive statistical analysis has been performed to verify our experiments. The results show that a simple network structure for both the multi-layer perceptron and radial basis function can produce equally good results, not all attributes are needed to train these algorithms and, finally, the classification performances of all algorithms are statistically robust. Moreover, we have shown that the best performing algorithm will strongly depend on the features of the datasets, and hence, there is not necessarily a single best classifier.
Examining the impact of child parent relationship therapy (CPRT) on family functioning.
Cornett, Nick; Bratton, Sue C
2014-07-01
Research supports that child parent relationship therapy (CPRT), a filial therapy approach, has strong effects on participating parents and children. Some speculate that filial therapy improves the family system; however, minimal research exists to support this claim. Using a single-case design, researchers examined CPRT's impact on the functioning of 8 families. Results revealed that 6 families experienced statistically significant improvements in targeted areas of family functioning. Results from self-reported measures indicated that 7 families improved in family satisfaction, 4 in cohesion, 3 in communication, and 1 in flexibility. Observational measures also revealed improvements: 5 families in flexibility, 4 families in cohesion, and 4 families in communication. The results support that the benefits of CPRT may extend to the family system. © 2013 American Association for Marriage and Family Therapy.
Statistical analysis of plasmatrough exohiss waves on Van Allen Probes
NASA Astrophysics Data System (ADS)
Zhu, H.; Chen, L.
2017-12-01
Plasmatrough exohiss waves have attracted much attention due to their potential important role in dynamics of radiation belt. We investigated three-year Van Allen Probe data and built up an event list of exohiss. The statistical analysis shows exohiss preferentially occurred in dayside at quite time and most wave power focuses on afternoon side of low L region. Consistent with plasmaspheric hiss, the peak frequency is around 200 Hz and wave amplitude decreases with L increasing. Furthermore, the ratios of equatorward Poynting fluxes to poleward Poynting fluxes significantly increase up to 10 times as magnetic latitude increasing up to 20 deg. Those results strong support that the formation of exohiss wave results from hiss leakage, particularly at quite time.
Particle Acceleration in a Statistically Modeled Solar Active-Region Corona
NASA Astrophysics Data System (ADS)
Toutounzi, A.; Vlahos, L.; Isliker, H.; Dimitropoulou, M.; Anastasiadis, A.; Georgoulis, M.
2013-09-01
Elaborating a statistical approach to describe the spatiotemporally intermittent electric field structures formed inside a flaring solar active region, we investigate the efficiency of such structures in accelerating charged particles (electrons). The large-scale magnetic configuration in the solar atmosphere responds to the strong turbulent flows that convey perturbations across the active region by initiating avalanche-type processes. The resulting unstable structures correspond to small-scale dissipation regions hosting strong electric fields. Previous research on particle acceleration in strongly turbulent plasmas provides a general framework for addressing such a problem. This framework combines various electromagnetic field configurations obtained by magnetohydrodynamical (MHD) or cellular automata (CA) simulations, or by employing a statistical description of the field's strength and configuration with test particle simulations. Our objective is to complement previous work done on the subject. As in previous efforts, a set of three probability distribution functions describes our ad-hoc electromagnetic field configurations. In addition, we work on data-driven 3D magnetic field extrapolations. A collisional relativistic test-particle simulation traces each particle's guiding center within these configurations. We also find that an interplay between different electron populations (thermal/non-thermal, ambient/injected) in our simulations may also address, via a re-acceleration mechanism, the so called `number problem'. Using the simulated particle-energy distributions at different heights of the cylinder we test our results against observations, in the framework of the collisional thick target model (CTTM) of solar hard X-ray (HXR) emission. The above work is supported by the Hellenic National Space Weather Research Network (HNSWRN) via the THALIS Programme.
Stenner, Elisabetta; Barbati, Giulia; West, Nicole; Ben, Fabia Del; Martin, Francesca; Ruscio, Maurizio
2018-06-01
Our aim was to verify if procalcitonin (PCT) measurements using the new point-of-care testing i-CHROMATM are interchangeable with those of Liaison XL. One hundred seventeen serum samples were processed sequentially on a Liaison XL and i-CHROMATM. Statistical analysis was done using the Passing-Bablok regression, Bland-Altman test, and Cohen's Kappa statistic. Proportional and constant differences were observed between i-CHROMATM and Liaison XL. The 95% CI of the mean bias% was very large, exceeding the maximum allowable TE% and the clinical reference change value. However, the concordance between methods at the clinical relevant cutoffs was strong, with the exception of the 0.25 ng/mL cutoff which was moderate. Our data suggest that i-CHROMATM is not interchangeable with Liaison XL. However, while the strong concordance at the clinical relevant cutoffs allows us to consider i-CHROMATM a suitable option to Liaison XL to support clinicians' decision-making; nevertheless, the moderate agreement at the 0.25 ng/mL cutoff recommends caution in interpreting the data around this cutoff.
Stage-structured transmission of phocine distemper virus in the Dutch 2002 outbreak
Klepac, Petra; Pomeroy, Laura W.; Bjørnstad, Ottar N.; Kuiken, Thijs; Osterhaus, Albert D.M.E.; Rijks, Jolianne M.
2009-01-01
Heterogeneities in transmission among hosts can be very important in shaping infectious disease dynamics. In mammals with strong social organization, such heterogeneities are often structured by functional stage: juveniles, subadults and adults. We investigate the importance of such stage-related heterogeneities in shaping the 2002 phocine distemper virus (PDV) outbreak in the Dutch Wadden Sea, when more than 40 per cent of the harbour seals were killed. We do this by comparing the statistical fit of a hierarchy of models with varying transmission complexity: homogeneous versus heterogeneous mixing and density- versus frequency-dependent transmission. We use the stranding data as a proxy for incidence and use Poisson likelihoods to estimate the ‘who acquires infection from whom’ (WAIFW) matrix. Statistically, the model with strong heterogeneous mixing and density-dependent transmission was found to best describe the transmission dynamics. However, patterns of incidence support a model of frequency-dependent transmission among adults and juveniles. Based on the maximum-likelihood WAIFW matrix estimates, we use the next-generation formalism to calculate an R0 between 2 and 2.5 for the Dutch 2002 PDV epidemic. PMID:19364743
The Infeasibility of Experimental Quantification of Life-Critical Software Reliability
NASA Technical Reports Server (NTRS)
Butler, Ricky W.; Finelli, George B.
1991-01-01
This paper affirms that quantification of life-critical software reliability is infeasible using statistical methods whether applied to standard software or fault-tolerant software. The key assumption of software fault tolerance|separately programmed versions fail independently|is shown to be problematic. This assumption cannot be justified by experimentation in the ultra-reliability region and subjective arguments in its favor are not sufficiently strong to justify it as an axiom. Also, the implications of the recent multi-version software experiments support this affirmation.
Apsler, R; Blackman, C
1979-01-01
Results from a random household survey of the Boston Standard Metropolitan Statistical Area show a consistent and relatively strong association of adults' use of coffee, tobacco, alcohol, tranquilizers, and marijuana with their perceptions of present friends' use. Associations with parents' and past adolescent friends' use are much weaker. The results support efforts to explain illicit drug use with general theories of behavior acquisition and cast doubt on the utility of deviance theories.
Smeltzer, Suzanne C; Sharts-Hopko, Nancy C; Cantrell, Mary Ann; Heverly, Mary Ann; Wise, Nancy; Jenkinson, Amanda
Support for research strongly predicts doctoral program faculty members' research productivity. Although academic administrators affect such support, their views of faculty members' use of support are unknown. We examined academic administrators' perceptions of institutional support and their perceptions of the effects of teaching doctoral students on faculty members' scholarship productivity and work-life balance. An online survey was completed by a random sample of 180 deans/directors of schools of nursing and doctoral programs directors. Data were analyzed with descriptive statistics, chi-square analysis, and analysis of variance. Deans and doctoral program directors viewed the level of productivity of program faculty as high to moderately high and unchanged since faculty started teaching doctoral students. Deans perceived better administrative research supports, productivity, and work-life balance of doctoral program faculty than did program directors. Findings indicate the need for greater administrative support for scholarship and mentoring given the changes in the composition of doctoral program faculty. Copyright © 2017 Elsevier Inc. All rights reserved.
Ojo, Oluwaseun S; Malomo, Sunday O; Sogunle, Peter T
2016-01-01
Nonadherence to therapeutic plans has been reported among hypertensive patients. Researchers have also shown that adherence to therapeutic plans improves if motivation in the form of social support is provided. There is a dearth of local studies that explore the influence of family support on treatment outcomes of hypertensive patients. The aim of the study was to determine the relationship between BP control and perceived family support in patients with essential hypertension seen at a primary care setting in Western Nigeria. This was a cross-sectional hospital-based study. Systematic random sampling technique was used in selecting 360 hypertensive respondents between April and July 2013. Data were collected through a pretested interviewer-administered questionnaire and a standardized tool, Perceived Social Support Family Scale, which measured the respondents' level of perceived family support. Statistical Package for Social Sciences (SPSS) version 17.0 was used to analyze data. The majority of the respondents were middle-aged (61.1%) and female (59.4%). Blood pressure (BP) was controlled in 46.4% of the respondents. Most of the respondents (79.4%) had "strong" perceived family support. Strong perceived family support (odds ratio [OR] 4.778, 95% confidence interval [CI] =2.569-8.887) and female gender (OR 1.838, 95% CI = 1.177-2.869) were independent predictors of controlled BP. The proportion of hypertensive patients with optimal BP control is low in this practice setting. The positive association between BP control and perceived family support emphasizes the need for physicians to reflect on the available family support when managing hypertensive patients.
Noman, Abu Hanifa Md; Gee, Chan Sok; Isa, Che Ruhana
2017-01-01
This study examines the influence of competition on the financial stability of the commercial banks of Association of Southeast Asian Nation (ASEAN) over the 1990 to 2014 period. Panzar-Rosse H-statistic, Lerner index and Herfindahl-Hirschman Index (HHI) are used as measures of competition, while Z-score, non-performing loan (NPL) ratio and equity ratio are used as measures of financial stability. Two-step system Generalized Method of Moments (GMM) estimates demonstrate that competition measured by H-statistic is positively related to Z-score and equity ratio, and negatively related to non-performing loan ratio. Conversely, market power measured by Lerner index is negatively related to Z-score and equity ratio and positively related to NPL ratio. These results strongly support the competition-stability view for ASEAN banks. We also capture the non-linear relationship between competition and financial stability by incorporating a quadratic term of competition in our models. The results show that the coefficient of the quadratic term of H-statistic is negative for the Z-score model given a positive coefficient of the linear term in the same model. These results support the non-linear relationship between competition and financial stability of the banking sector. The study contains significant policy implications for improving the financial stability of the commercial banks.
Gee, Chan Sok; Isa, Che Ruhana
2017-01-01
This study examines the influence of competition on the financial stability of the commercial banks of Association of Southeast Asian Nation (ASEAN) over the 1990 to 2014 period. Panzar-Rosse H-statistic, Lerner index and Herfindahl-Hirschman Index (HHI) are used as measures of competition, while Z-score, non-performing loan (NPL) ratio and equity ratio are used as measures of financial stability. Two-step system Generalized Method of Moments (GMM) estimates demonstrate that competition measured by H-statistic is positively related to Z-score and equity ratio, and negatively related to non-performing loan ratio. Conversely, market power measured by Lerner index is negatively related to Z-score and equity ratio and positively related to NPL ratio. These results strongly support the competition-stability view for ASEAN banks. We also capture the non-linear relationship between competition and financial stability by incorporating a quadratic term of competition in our models. The results show that the coefficient of the quadratic term of H-statistic is negative for the Z-score model given a positive coefficient of the linear term in the same model. These results support the non-linear relationship between competition and financial stability of the banking sector. The study contains significant policy implications for improving the financial stability of the commercial banks. PMID:28486548
Analysis of pediatric blood lead levels in New York City for 1970-1976.
Billick, I H; Curran, A S; Shier, D R
1979-01-01
A study was completed of more than 170,000 records of pediatric venous blood levels and supporting demographic information collected in New York City during 1970-1976. The geometric mean (GM) blood lead level shows a consistent cyclical variation superimposed on an overall decreasing trend with time for all ages and ethnic groups studied. The GM blood lead levels for blacks are significantly greater than those for either Hispanics or whites. Regression analysis indicates a significant statistical association between GM blood lead level and ambient air lead level, after appropriate adjustments are made for age and ethnic group. These highly significant statistical relationships provide extremely strong incentives and directions for research into casual factors related to blood lead levels in children. PMID:499123
Four types of ensemble coding in data visualizations.
Szafir, Danielle Albers; Haroz, Steve; Gleicher, Michael; Franconeri, Steven
2016-01-01
Ensemble coding supports rapid extraction of visual statistics about distributed visual information. Researchers typically study this ability with the goal of drawing conclusions about how such coding extracts information from natural scenes. Here we argue that a second domain can serve as another strong inspiration for understanding ensemble coding: graphs, maps, and other visual presentations of data. Data visualizations allow observers to leverage their ability to perform visual ensemble statistics on distributions of spatial or featural visual information to estimate actual statistics on data. We survey the types of visual statistical tasks that occur within data visualizations across everyday examples, such as scatterplots, and more specialized images, such as weather maps or depictions of patterns in text. We divide these tasks into four categories: identification of sets of values, summarization across those values, segmentation of collections, and estimation of structure. We point to unanswered questions for each category and give examples of such cross-pollination in the current literature. Increased collaboration between the data visualization and perceptual psychology research communities can inspire new solutions to challenges in visualization while simultaneously exposing unsolved problems in perception research.
Diapycnal Advection by Double Diffusion and Turbulence in the Ocean
1999-09-01
quadrant of the map. To evaluate the significance of the finger-regime results, we have implemented a simple statistical test. The dissipation ratio...accepted in nearly all of quadrants I, III and IV of the finger-favorable regime. However, the data in quadrant II (Rp ɚ,Ri> 1) strongly supports the...region of parameter space ( quadrant II, (Rp ɚ,Ri> 1)). 44 1.01 R R R P p p 1.1 1.5 2.5 5 10 30 1001.01 1.1 1.5 2.5 5 10 30
Pauling, Linus; Kamb, Barclay
1985-01-01
The statistical resonating-valence-bond theory of metals is applied in the purely theoretical calculation of the composition of the Ni-Cu alloy at the foot of the curve of saturation ferromagnetic moment, which marks the boundary between hypoelectronic and hyperelectronic metals and determines the value of the number of metallic orbitals per atom. The results, Ni44Cu56 and 0.722 metallic orbitals, agree with the observed values. This agreement provides strong support of the theory. PMID:16593633
Comparable Stocks, Boundedly Rational Stock Markets and IPO Entry Rates
Chok, Jay; Qian, Jifeng
2013-01-01
In this study, we examine how initial public offerings (IPO) entry rates are affected when stock markets are boundedly rational and IPO firms infer information from their counterparts in the market. We hypothesize a curvilinear relationship between the number of comparable stocks and initial public offerings (IPO) entry rates into the NASDAQ Stock Exchange. Furthermore, we argue that trading volume and changes in stock returns partially mediates the relationship between the number of comparable stocks and IPO entry rates. The statistical evidence provides strong support for the hypotheses. PMID:23690924
Comparable stocks, boundedly rational stock markets and IPO entry rates.
Chok, Jay; Qian, Jifeng
2013-01-01
In this study, we examine how initial public offerings (IPO) entry rates are affected when stock markets are boundedly rational and IPO firms infer information from their counterparts in the market. We hypothesize a curvilinear relationship between the number of comparable stocks and initial public offerings (IPO) entry rates into the NASDAQ Stock Exchange. Furthermore, we argue that trading volume and changes in stock returns partially mediates the relationship between the number of comparable stocks and IPO entry rates. The statistical evidence provides strong support for the hypotheses.
Freyre-González, Julio A; Tauch, Andreas
2017-09-10
Corynebacterium glutamicum is a Gram-positive, anaerobic, rod-shaped soil bacterium able to grow on a diversity of carbon sources like sugars and organic acids. It is a biotechnological relevant organism because of its highly efficient ability to biosynthesize amino acids, such as l-glutamic acid and l-lysine. Here, we reconstructed the most complete C. glutamicum regulatory network to date and comprehensively analyzed its global organizational properties, systems-level features and functional architecture. Our analyses show the tremendous power of Abasy Atlas to study the functional organization of regulatory networks. We created two models of the C. glutamicum regulatory network: all-evidences (containing both weak and strong supported interactions, genomic coverage=73%) and strongly-supported (only accounting for strongly supported evidences, genomic coverage=71%). Using state-of-the-art methodologies, we prove that power-law behaviors truly govern the connectivity and clustering coefficient distributions. We found a non-previously reported circuit motif that we named complex feed-forward motif. We highlighted the importance of feedback loops for the functional architecture, beyond whether they are statistically over-represented or not in the network. We show that the previously reported top-down approach is inadequate to infer the hierarchy governing a regulatory network because feedback bridges different hierarchical layers, and the top-down approach disregards the presence of intermodular genes shaping the integration layer. Our findings all together further support a diamond-shaped, three-layered hierarchy exhibiting some feedback between processing and coordination layers, which is shaped by four classes of systems-level elements: global regulators, locally autonomous modules, basal machinery and intermodular genes. Copyright © 2016 Elsevier B.V. All rights reserved.
Geomagnetic South Atlantic Anomaly and global sea level rise: A direct connection?
NASA Astrophysics Data System (ADS)
de Santis, A.; Qamili, E.; Spada, G.; Gasperini, P.
2012-01-01
We highlight the existence of an intriguing and to date unreported relationship between the surface area of the South Atlantic Anomaly (SAA) of the geomagnetic field and the current trend in global sea level rise. These two geophysical variables have been growing coherently during the last three centuries, thus strongly suggesting a causal relationship supported by some statistical tests. The monotonic increase of the SAA surface area since 1600 may have been associated with an increased inflow of radiation energy through the inner Van Allen belt with a consequent warming of the Earth's atmosphere and finally global sea level rise. An alternative suggestive and original explanation is also offered, in which pressure changes at the core-mantle boundary cause surface deformations and relative sea level variations. Although we cannot establish a clear connection between SAA dynamics and global warming, the strong correlation between the former and global sea level supports the idea that global warming may be at least partly controlled by deep Earth processes triggering geomagnetic phenomena, such as the South Atlantic Anomaly, on a century time scale.
Seibert, Scott E; Wang, Gang; Courtright, Stephen H
2011-09-01
This paper provides meta-analytic support for an integrated model specifying the antecedents and consequences of psychological and team empowerment. Results indicate that contextual antecedent constructs representing perceived high-performance managerial practices, socio-political support, leadership, and work characteristics are each strongly related to psychological empowerment. Positive self-evaluation traits are related to psychological empowerment and are as strongly related as the contextual factors. Psychological empowerment is in turn positively associated with a broad range of employee outcomes, including job satisfaction, organizational commitment, and task and contextual performance, and is negatively associated with employee strain and turnover intentions. Team empowerment is positively related to team performance. Further, the magnitude of parallel antecedent and outcome relationships at the individual and team levels is statistically indistinguishable, demonstrating the generalizability of empowerment theory across these 2 levels of analysis. A series of analyses also demonstrates the validity of psychological empowerment as a unitary second-order construct. Implications and future directions for empowerment research and theory are discussed. PsycINFO Database Record (c) 2011 APA, all rights reserved
Density by moduli and Wijsman lacunary statistical convergence of sequences of sets.
Bhardwaj, Vinod K; Dhawan, Shweta
2017-01-01
The main object of this paper is to introduce and study a new concept of f -Wijsman lacunary statistical convergence of sequences of sets, where f is an unbounded modulus. The definition of Wijsman lacunary strong convergence of sequences of sets is extended to a definition of Wijsman lacunary strong convergence with respect to a modulus for sequences of sets and it is shown that, under certain conditions on a modulus f , the concepts of Wijsman lacunary strong convergence with respect to a modulus f and f -Wijsman lacunary statistical convergence are equivalent on bounded sequences. We further characterize those θ for which [Formula: see text], where [Formula: see text] and [Formula: see text] denote the sets of all f -Wijsman lacunary statistically convergent sequences and f -Wijsman statistically convergent sequences, respectively.
Zhang, Zhefeng; Xian, Jiahui; Zhang, Chunyong; Fu, Degang
2017-09-01
This study investigated the degradation performance and mechanism of creatinine (a urine metabolite) with boron-doped diamond (BDD) anodes. Experiments were performed using a synthetic creatinine solution containing two supporting electrolytes (NaCl and Na 2 SO 4 ). A three-level central composite design was adopted to optimize the degradation process, a mathematical model was thus constructed and used to explore the optimum operating conditions. A maximum mineralization percentage of 80% following with full creatinine removal had been achieved within 120 min of electrolysis, confirming the strong oxidation capability of BDD anodes. Moreover, the results obtained suggested that supporting electrolyte concentration should be listed as one of the most important parameters in BDD technology. Lastly, based on the results from quantum chemistry calculations and LC/MS analyses, two different reaction pathways which governed the electrocatalytic oxidation of creatinine irrespective of the supporting electrolytes were identified. Copyright © 2017 Elsevier Ltd. All rights reserved.
Phylogenomic Data Yield New and Robust Insights into the Phylogeny and Evolution of Weevils.
Shin, Seunggwan; Clarke, Dave J; Lemmon, Alan R; Moriarty Lemmon, Emily; Aitken, Alexander L; Haddad, Stephanie; Farrell, Brian D; Marvaldi, Adriana E; Oberprieler, Rolf G; McKenna, Duane D
2018-04-01
The phylogeny and evolution of weevils (the beetle superfamily Curculionoidea) has been extensively studied, but many relationships, especially in the large family Curculionidae (true weevils; > 50,000 species), remain uncertain. We used phylogenomic methods to obtain DNA sequences from 522 protein-coding genes for representatives of all families of weevils and all subfamilies of Curculionidae. Most of our phylogenomic results had strong statistical support, and the inferred relationships were generally congruent with those reported in previous studies, but with some interesting exceptions. Notably, the backbone relationships of the weevil phylogeny were consistently strongly supported, and the former Nemonychidae (pine flower snout beetles) were polyphyletic, with the subfamily Cimberidinae (here elevated to Cimberididae) placed as sister group of all other weevils. The clade comprising the sister families Brentidae (straight-snouted weevils) and Curculionidae was maximally supported and the composition of both families was firmly established. The contributions of substitution modeling, codon usage and/or mutational bias to differences between trees reconstructed from amino acid and nucleotide sequences were explored. A reconstructed timetree for weevils is consistent with a Mesozoic radiation of gymnosperm-associated taxa to form most extant families and diversification of Curculionidae alongside flowering plants-first monocots, then other groups-beginning in the Cretaceous.
Reproducibility in Psychological Science: When Do Psychological Phenomena Exist?
Iso-Ahola, Seppo E.
2017-01-01
Scientific evidence has recently been used to assert that certain psychological phenomena do not exist. Such claims, however, cannot be made because (1) scientific method itself is seriously limited (i.e., it can never prove a negative); (2) non-existence of phenomena would require a complete absence of both logical (theoretical) and empirical support; even if empirical support is weak, logical and theoretical support can be strong; (3) statistical data are only one piece of evidence and cannot be used to reduce psychological phenomena to statistical phenomena; and (4) psychological phenomena vary across time, situations and persons. The human mind is unreproducible from one situation to another. Psychological phenomena are not particles that can decisively be tested and discovered. Therefore, a declaration that a phenomenon is not real is not only theoretically and empirically unjustified but runs counter to the propositional and provisional nature of scientific knowledge. There are only “temporary winners” and no “final truths” in scientific knowledge. Psychology is a science of subtleties in human affect, cognition and behavior. Its phenomena fluctuate with conditions and may sometimes be difficult to detect and reproduce empirically. When strictly applied, reproducibility is an overstated and even questionable concept in psychological science. Furthermore, statistical measures (e.g., effect size) are poor indicators of the theoretical importance and relevance of phenomena (cf. “deliberate practice” vs. “talent” in expert performance), not to mention whether phenomena are real or unreal. To better understand psychological phenomena, their theoretical and empirical properties should be examined via multiple parameters and criteria. Ten such parameters are suggested. PMID:28626435
Hu, Ting; Pan, Qinxin; Andrew, Angeline S; Langer, Jillian M; Cole, Michael D; Tomlinson, Craig R; Karagas, Margaret R; Moore, Jason H
2014-04-11
Several different genetic and environmental factors have been identified as independent risk factors for bladder cancer in population-based studies. Recent studies have turned to understanding the role of gene-gene and gene-environment interactions in determining risk. We previously developed the bioinformatics framework of statistical epistasis networks (SEN) to characterize the global structure of interacting genetic factors associated with a particular disease or clinical outcome. By applying SEN to a population-based study of bladder cancer among Caucasians in New Hampshire, we were able to identify a set of connected genetic factors with strong and significant interaction effects on bladder cancer susceptibility. To support our statistical findings using networks, in the present study, we performed pathway enrichment analyses on the set of genes identified using SEN, and found that they are associated with the carcinogen benzo[a]pyrene, a component of tobacco smoke. We further carried out an mRNA expression microarray experiment to validate statistical genetic interactions, and to determine if the set of genes identified in the SEN were differentially expressed in a normal bladder cell line and a bladder cancer cell line in the presence or absence of benzo[a]pyrene. Significant nonrandom sets of genes from the SEN were found to be differentially expressed in response to benzo[a]pyrene in both the normal bladder cells and the bladder cancer cells. In addition, the patterns of gene expression were significantly different between these two cell types. The enrichment analyses and the gene expression microarray results support the idea that SEN analysis of bladder in population-based studies is able to identify biologically meaningful statistical patterns. These results bring us a step closer to a systems genetic approach to understanding cancer susceptibility that integrates population and laboratory-based studies.
[Organizational climate and burnout syndrome].
Lubrańska, Anna
2011-01-01
The paper addresses the issue of organizational climate and burnout syndrome. It has been assumed that burnout syndrome is dependent on work climate (organizational climate), therefore, two concepts were analyzed: by D. Kolb (organizational climate) and by Ch. Maslach (burnout syndrome). The research involved 239 persons (122 woman, 117 men), aged 21-66. In the study Maslach Burnout Inventory (MBI) and Inventory of Organizational Climate were used. The results of statistical methods (correlation analysis, one-variable analysis of variance and regression analysis) evidenced a strong relationship between organizational climate and burnout dimension. As depicted by the results, there are important differences in the level of burnout between the study participants who work in different types of organizational climate. The results of the statistical analyses indicate that the organizational climate determines burnout syndrome. Therefore, creating supportive conditions at the workplace might reduce the risk of burnout.
Heart Rate Variability Dynamics for the Prognosis of Cardiovascular Risk
Ramirez-Villegas, Juan F.; Lam-Espinosa, Eric; Ramirez-Moreno, David F.; Calvo-Echeverry, Paulo C.; Agredo-Rodriguez, Wilfredo
2011-01-01
Statistical, spectral, multi-resolution and non-linear methods were applied to heart rate variability (HRV) series linked with classification schemes for the prognosis of cardiovascular risk. A total of 90 HRV records were analyzed: 45 from healthy subjects and 45 from cardiovascular risk patients. A total of 52 features from all the analysis methods were evaluated using standard two-sample Kolmogorov-Smirnov test (KS-test). The results of the statistical procedure provided input to multi-layer perceptron (MLP) neural networks, radial basis function (RBF) neural networks and support vector machines (SVM) for data classification. These schemes showed high performances with both training and test sets and many combinations of features (with a maximum accuracy of 96.67%). Additionally, there was a strong consideration for breathing frequency as a relevant feature in the HRV analysis. PMID:21386966
Gender identity disorders and multiple sclerosis risk: A national record-linkage study.
Pakpoor, Julia; Wotton, Clare J; Schmierer, Klaus; Giovannoni, Gavin; Goldacre, Michael J
2016-11-01
An altered balance of gonadal hormones in males with gender identity disorders (GIDs) may increase multiple sclerosis (MS) risk both inherently and secondary to treatment in undergoing male-to-female conversion. We investigated any association between GIDs and MS through analysis of record-linked hospital statistics. Analysis of English Hospital Episode Statistics, 1999-2012. The adjusted rate ratio (RR) of MS following GIDs in males was 6.63 (95% confidence interval (95% CI) = 1.81-17.01, p = 0.0002). The RR of MS following GIDs in females was 1.44 (95% CI = 0.47-3.37, p = 0.58). We report a strong association between GIDs and MS in male-to-females, supporting a potential role for low testosterone and/or feminising hormones on MS risk in males. © The Author(s), 2016.
The relationship between family support; pain and depression in elderly with arthritis.
Hung, Man; Bounsanga, Jerry; Voss, Maren W; Crum, Anthony B; Chen, Wei; Birmingham, Wendy C
2017-01-01
The prevalence and chronic nature of arthritis make it the most common cause of disability among U.S.A adults. Family support reduces the negative impact of chronic conditions generally but its role in pain and depression for arthritic conditions is not well understood. A total of 844 males (35.0%) and 1567 females (65.0%) with arthritic conditions (n = 2411) were drawn from the 2012 Health and Retirement Study to examine the effect of family support on pain and depressive symptoms. Using regression analysis and controlling for age, ethnicity, gender, marital/educational status and employment/income, physical function/disability status, pain and antidepressant medications, and other clinical indicators of chronic health conditions, we examined the effects of family support (spouse, children, other) on pain and depression levels. Results indicated that depressive symptoms decreased significantly with strong family and spousal support (p < .05). Pain decreased as support levels increased, but was non-statistically significant. This study provides new insights into the relationship between family support, pain, and depression for individuals with arthritis. Future longitudinal studies are needed to evaluate family support and relationships over a wider spectrum of demographics.
Perspectives of dental students and faculty about evidence-based dental practice.
Abdelkarim, Ahmad; Sullivan, Donna
2014-12-01
The study aimed at evaluating attitudes and perceptions of dental students and faculty toward evidence-based practice, integration of technology and social media, general practitioners' and specialists' scope of practice, and dental practice rewards and disadvantages. A survey instrument was designed with 10 statements rated on a five-point Likert scale (strongly agree to strongly disagree) and an optional comment section. The survey instrument was delivered through SurveyMonkey, whereby 401 students and 182 faculty members from ten U.S. dental schools participated (16% estimated response rate). Null hypotheses regarding the equality between the responses of the two groups were statistically tested using Mann-Whitney U test. Statistical significance was set at .05. Evidence-based practice is positively perceived by both groups, but with significantly higher support by faculty than students (P = 0.002). Both groups agreed that technological advancements are advantageous (P = 0.95), but do not constitute good dentistry and cannot mask poor clinical skills. Students showed higher support for social media than faculty (P = 0.000). Both groups perceived group practices positively. Faculty members showed higher agreement than students toward limitation of dental specialists' practices to their specialties (P = 0.000). Both groups are aware of practice disadvantages, such as increased litigation, health risks, and detriment to the dentist's posture. However, they both perceive dental practice positively despite all these challenges. Students and faculty share generally comparable perspectives toward dental practice. They are both in agreement with evidence-based practice and adoption of technology. They both acknowledge practice limitations. Copyright © 2014 Elsevier Inc. All rights reserved.
Analysis of a genetically structured variance heterogeneity model using the Box-Cox transformation.
Yang, Ye; Christensen, Ole F; Sorensen, Daniel
2011-02-01
Over recent years, statistical support for the presence of genetic factors operating at the level of the environmental variance has come from fitting a genetically structured heterogeneous variance model to field or experimental data in various species. Misleading results may arise due to skewness of the marginal distribution of the data. To investigate how the scale of measurement affects inferences, the genetically structured heterogeneous variance model is extended to accommodate the family of Box-Cox transformations. Litter size data in rabbits and pigs that had previously been analysed in the untransformed scale were reanalysed in a scale equal to the mode of the marginal posterior distribution of the Box-Cox parameter. In the rabbit data, the statistical evidence for a genetic component at the level of the environmental variance is considerably weaker than that resulting from an analysis in the original metric. In the pig data, the statistical evidence is stronger, but the coefficient of correlation between additive genetic effects affecting mean and variance changes sign, compared to the results in the untransformed scale. The study confirms that inferences on variances can be strongly affected by the presence of asymmetry in the distribution of data. We recommend that to avoid one important source of spurious inferences, future work seeking support for a genetic component acting on environmental variation using a parametric approach based on normality assumptions confirms that these are met.
λ (Δim) -statistical convergence of order α
NASA Astrophysics Data System (ADS)
Colak, Rifat; Et, Mikail; Altin, Yavuz
2017-09-01
In this study, using the generalized difference operator Δim and a sequence λ = (λn) which is a non-decreasing sequence of positive numbers tending to ∞ such that λn+1 ≤ λn+1, λ1 = 1, we introduce the concepts of λ (Δim) -statistical convergence of order α (α ∈ (0, 1]) and strong λ (Δim) -Cesàro summablility of order α (α > 0). We establish some connections between λ (Δim) -statistical convergence of order α and strong λ (Δim) -Cesàro summablility of order α. It is shown that if a sequence is strongly λ (Δim) -Cesàro summable of order α, then it is λ (Δim) -statistically convergent of order β in case 0 < α ≤ β ≤ 1.
Environmental Variables Explain Genetic Structure in a Beetle-Associated Nematode
McGaughran, Angela; Morgan, Katy; Sommer, Ralf J.
2014-01-01
The distribution of a species is a complex expression of its ecological and evolutionary history and integrating population genetic, environmental, and ecological data can provide new insights into the effects of the environment on the population structure of species. Previous work demonstrated strong patterns of genetic differentiation in natural populations of the hermaphroditic nematode Pristionchus pacificus in its La Réunion Island habitat, but gave no clear understanding of the role of the environment in structuring this variation. Here, we present what is to our knowledge the first study to statistically evaluate the role of the environment in shaping the structure and distribution of nematode populations. We test the hypothesis that genetic structure in P. pacificus is influenced by environmental variables, by combining population genetic analyses of microsatellite data from 18 populations and 370 strains, with multivariate statistics on environmental data, and species distribution modelling. We assess and quantify the relative importance of environmental factors (geographic distance, altitude, temperature, precipitation, and beetle host) on genetic variation among populations. Despite the fact that geographic populations of P. pacificus comprise vast genetic diversity sourced from multiple ancestral lineages, we find strong evidence for local associations between environment and genetic variation. Further, we show that significantly more genetic variation in P. pacificus populations is explained by environmental variation than by geographic distances. This supports a strong role for environmental heterogeneity vs. genetic drift in the divergence of populations, which we suggest may be influenced by adaptive forces. PMID:24498073
Sirota, Miroslav; Kostovičová, Lenka; Juanchich, Marie
2014-08-01
Knowing which properties of visual displays facilitate statistical reasoning bears practical and theoretical implications. Therefore, we studied the effect of one property of visual diplays - iconicity (i.e., the resemblance of a visual sign to its referent) - on Bayesian reasoning. Two main accounts of statistical reasoning predict different effect of iconicity on Bayesian reasoning. The ecological-rationality account predicts a positive iconicity effect, because more highly iconic signs resemble more individuated objects, which tap better into an evolutionary-designed frequency-coding mechanism that, in turn, facilitates Bayesian reasoning. The nested-sets account predicts a null iconicity effect, because iconicity does not affect the salience of a nested-sets structure-the factor facilitating Bayesian reasoning processed by a general reasoning mechanism. In two well-powered experiments (N = 577), we found no support for a positive iconicity effect across different iconicity levels that were manipulated in different visual displays (meta-analytical overall effect: log OR = -0.13, 95% CI [-0.53, 0.28]). A Bayes factor analysis provided strong evidence in favor of the null hypothesis-the null iconicity effect. Thus, these findings corroborate the nested-sets rather than the ecological-rationality account of statistical reasoning.
NASA Astrophysics Data System (ADS)
Cheng, Meng; Tantivasadakarn, Nathanan; Wang, Chenjie
2018-01-01
We study Abelian braiding statistics of loop excitations in three-dimensional gauge theories with fermionic particles and the closely related problem of classifying 3D fermionic symmetry-protected topological (FSPT) phases with unitary symmetries. It is known that the two problems are related by turning FSPT phases into gauge theories through gauging the global symmetry of the former. We show that there exist certain types of Abelian loop braiding statistics that are allowed only in the presence of fermionic particles, which correspond to 3D "intrinsic" FSPT phases, i.e., those that do not stem from bosonic SPT phases. While such intrinsic FSPT phases are ubiquitous in 2D systems and in 3D systems with antiunitary symmetries, their existence in 3D systems with unitary symmetries was not confirmed previously due to the fact that strong interaction is necessary to realize them. We show that the simplest unitary symmetry to support 3D intrinsic FSPT phases is Z2×Z4. To establish the results, we first derive a complete set of physical constraints on Abelian loop braiding statistics. Solving the constraints, we obtain all possible Abelian loop braiding statistics in 3D gauge theories, including those that correspond to intrinsic FSPT phases. Then, we construct exactly soluble state-sum models to realize the loop braiding statistics. These state-sum models generalize the well-known Crane-Yetter and Dijkgraaf-Witten models.
Influence of social support on cognitive function in the elderly.
Yeh, Shu-Chuan Jennifer; Liu, Yea-Ying
2003-05-30
Social support is important in daily activities of the elderly. This study tests the hypothesis that there is an association between social support and cognitive function among the elderly in a community setting. Face-to-face interviews were conducted in a cross-sectional stratified random sample of 4,993 elderly (> or =65 years) city residents. Using multiple regression analysis, we investigated the influence of social support on cognitive function. 12% were over 80 years old. 53.28% were men. 67.14% were married. Higher Short Portable Mental Status Questionnaire (SPMSQ) scores (higher score means better cognitive function) were associated with strong social support, as measured by marital status and perceived positive support from friends. Lower cognitive function was associated with older and with female respondents. Only instrumental activities of daily living (IADL) were statistically and negatively related to SPMSQ. Lower functional status was associated with lower cognitive function. Elders with grade school educations had lower SPMSQ scores than did elders with high school educations. In Taiwan, higher cognitive function in community-living elderly was associated with increased social support. Life-style management should provide social activities for the elderly to promote a better quality of life.
ERIC Educational Resources Information Center
Leavy, Aisling; Hourigan, Mairead
2016-01-01
We argue that the development of statistical literacy is greatly supported by engaging students in carrying out statistical investigations. We describe the use of driving questions and interesting contexts to motivate two statistical investigations. The PPDAC cycle is use as an organizing framework to support the process statistical investigation.
NASA Astrophysics Data System (ADS)
Müller, M. F.; Thompson, S. E.
2015-09-01
The prediction of flow duration curves (FDCs) in ungauged basins remains an important task for hydrologists given the practical relevance of FDCs for water management and infrastructure design. Predicting FDCs in ungauged basins typically requires spatial interpolation of statistical or model parameters. This task is complicated if climate becomes non-stationary, as the prediction challenge now also requires extrapolation through time. In this context, process-based models for FDCs that mechanistically link the streamflow distribution to climate and landscape factors may have an advantage over purely statistical methods to predict FDCs. This study compares a stochastic (process-based) and statistical method for FDC prediction in both stationary and non-stationary contexts, using Nepal as a case study. Under contemporary conditions, both models perform well in predicting FDCs, with Nash-Sutcliffe coefficients above 0.80 in 75 % of the tested catchments. The main drives of uncertainty differ between the models: parameter interpolation was the main source of error for the statistical model, while violations of the assumptions of the process-based model represented the main source of its error. The process-based approach performed better than the statistical approach in numerical simulations with non-stationary climate drivers. The predictions of the statistical method under non-stationary rainfall conditions were poor if (i) local runoff coefficients were not accurately determined from the gauge network, or (ii) streamflow variability was strongly affected by changes in rainfall. A Monte Carlo analysis shows that the streamflow regimes in catchments characterized by a strong wet-season runoff and a rapid, strongly non-linear hydrologic response are particularly sensitive to changes in rainfall statistics. In these cases, process-based prediction approaches are strongly favored over statistical models.
Chromium isotopic anomalies in the Allende meteorite
NASA Technical Reports Server (NTRS)
Papanastassiou, D. A.
1986-01-01
Abundances of the chromium isotopes in terrestrial and bulk meteorite samples are identical to 0.01 percent. However, Ca-Al-rich inclusions from the Allende meteorite show endemic isotopic anomalies in chromium which require at least three nucleosynthetic components. Large anomalies at Cr-54 in a special class of inclusions are correlated with large anomalies at Ca-48 and Ti-50 and provide strong support for a component reflecting neutron-rich nucleosynthesis at nuclear statistical equilibrium. This correlation suggests that materials from very near the core of an exploding massive star may be injected into the interstellar medium.
CHILD CARE AVAILABILITY AND FIRST-BIRTH TIMING IN NORWAY*
Rindfuss, Ronald R.; Guilkey, David; Morgan, S. Philip; Kravdal, Øystein; Guzzo, Karen Benjamin
2010-01-01
Both sociological and economic theories posit that widely available, high-quality, and affordable child care should have pronatalist effects. Yet to date, the empirical evidence has not consistently supported this hypothesis. We argue that this previous empirical work has been plagued by the inability to control for endogenous placement of day care centers and the possibility that people migrate to take advantage of the availability of child care facilities. Using Norwegian register data and a statistically defensible fixed-effects model, we find strong positive effects of day care availability on the transition to motherhood. PMID:17583309
Yang, Xin-wei; Wang, Zhi-ming; Jin, Tai-yi; Lan, Ya-jia
2006-07-01
A study of the occupational stress norm and it's application for the executive group and administrative support group. In this study, cross-sectional study method is used, and a synthetic way of sorting and randomized sampling is adopted to deal with research targets (263 executive group, 569 administrative support group). Descriptive statistics for OSI-R scale scores for the executive group, administrative support group were modulated. Scale raw score to T-score conversion tables derived from the OSI-R normative sample for executive group, administrative support group were established. OSI-R profile from for executive group, administrative support group were established. For the ORQ and PSQ scales, scores at or above 70 indicate a strong levels of maladaptive stress and strain. Score inthe range of 60 to 69 suggest middle levels of maladaptive stress and strain. Score in the range of 40 to 59 indicate normal levels of stress and strain. Score below 40 indicate a relative absence of occupational stress and strain. For the PRQ scales, score below 30 indicate a significant lack of coping resources. Score in the range of 30 to 39 suggest middle deficits in coping resources. Score in the range of 40 to 59 indicate average coping resources. Scores at or above 60 indicate a strong levels of coping resources. Based on occupational Stress norm, raw score to T-score conversion tables, OSI-R profile form and classification criterion, we could estimate the level of occupation stress, stressor, strain and coping resources in different occupation. In addition, we combined subjective and objective environment match model of occupational stress. The various individual and organizational intervention measures should be taken to reduce the occupational stress and to increase coping so as to improve the work ability.
NASA Astrophysics Data System (ADS)
Lyons, M.; Siegel, Edward Carl-Ludwig
2011-03-01
Weiss-Page-Holthaus[Physica A,341,586(04); http://arxiv.org/abs/cond-mat/0403295] number-FACTORIZATION VIA BEQS BEC VS.(?) Shor-algorithm, strongly-supporting Watkins' [www.secamlocal.ex.ac.uk/people/staff/mrwatkin/] Intersection of number-theory "pure"-maths WITH (Statistical)-Physics, as Siegel[AMS Joint.Mtg.(02)-Abs.973-60-124] Benford logarithmic-law algebraic-INVERSION to ONLY BEQS with d=0 digit P (d = 0) > = oogapFULBEC ! ! ! SiegelRiemann - hypothesisproofviaRayleigh [ Phil . Trans . CLXI (1870) ] - Polya [ Math . Ann . (21) ] - [ Random - WalksElectric - Nets . , MAA (81) ] - nderson [ PRL (58) ] - localization - Siegel [ Symp . Fractals , MRSFallMtg . (89) - 5 - papers ! ! ! ] FUZZYICS = CATEGORYICS : [ LOCALITY ]- MORPHISM / CROSSOVER / AUTMATHCAT / DIM - CAT / ANTONYM- > (GLOBALITY) FUNCTOR / SYNONYM / concomitancetonoise = / Fluct . - Dissip . theorem / FUNCTOR / SYNONYM / equivalence / proportionalityto = > generalized - susceptibilitypower - spectrum [ FLAT / FUNCTIONLESS / WHITE ]- MORPHISM / CROSSOVER / AUTMATHCAT / DIM - CAT / ANTONYM- > HYPERBOLICITY/ZIPF-law INEVITABILITY) intersection with ONLY BEQS BEC).
Experimental observation of steady inertial wave turbulence in deep rotating flows
NASA Astrophysics Data System (ADS)
Yarom, Ehud; Sharon, Eran
2015-11-01
We present experimental evidence of inertial wave turbulence in deep rotating fluid. Experiments were performed in a rotating cylindrical water tank, where previous work showed statistics similar to 2D turbulence (specifically an inverse energy cascade). Using Fourier analysis of high resolution data in both space (3D) and time we show that most of the energy of a steady state flow is contained around the inertial wave dispersion relation. The nonlinear interaction between the waves is manifested by the widening of the time spectrum around the dispersion relation. We show that as the Rossby number increases so does the spectrum width, with a strong dependence on wave number. Our results suggest that in some parameters range, rotating turbulence velocity field can be represented as a field of interacting waves (wave turbulence). Such formalism may provide a better understanding of the flow statistics. This work was supported by the Israel Science Foundation, Grant No. 81/12.
Neandertal admixture in Eurasia confirmed by maximum-likelihood analysis of three genomes.
Lohse, Konrad; Frantz, Laurent A F
2014-04-01
Although there has been much interest in estimating histories of divergence and admixture from genomic data, it has proved difficult to distinguish recent admixture from long-term structure in the ancestral population. Thus, recent genome-wide analyses based on summary statistics have sparked controversy about the possibility of interbreeding between Neandertals and modern humans in Eurasia. Here we derive the probability of full mutational configurations in nonrecombining sequence blocks under both admixture and ancestral structure scenarios. Dividing the genome into short blocks gives an efficient way to compute maximum-likelihood estimates of parameters. We apply this likelihood scheme to triplets of human and Neandertal genomes and compare the relative support for a model of admixture from Neandertals into Eurasian populations after their expansion out of Africa against a history of persistent structure in their common ancestral population in Africa. Our analysis allows us to conclusively reject a model of ancestral structure in Africa and instead reveals strong support for Neandertal admixture in Eurasia at a higher rate (3.4-7.3%) than suggested previously. Using analysis and simulations we show that our inference is more powerful than previous summary statistics and robust to realistic levels of recombination.
Neandertal Admixture in Eurasia Confirmed by Maximum-Likelihood Analysis of Three Genomes
Lohse, Konrad; Frantz, Laurent A. F.
2014-01-01
Although there has been much interest in estimating histories of divergence and admixture from genomic data, it has proved difficult to distinguish recent admixture from long-term structure in the ancestral population. Thus, recent genome-wide analyses based on summary statistics have sparked controversy about the possibility of interbreeding between Neandertals and modern humans in Eurasia. Here we derive the probability of full mutational configurations in nonrecombining sequence blocks under both admixture and ancestral structure scenarios. Dividing the genome into short blocks gives an efficient way to compute maximum-likelihood estimates of parameters. We apply this likelihood scheme to triplets of human and Neandertal genomes and compare the relative support for a model of admixture from Neandertals into Eurasian populations after their expansion out of Africa against a history of persistent structure in their common ancestral population in Africa. Our analysis allows us to conclusively reject a model of ancestral structure in Africa and instead reveals strong support for Neandertal admixture in Eurasia at a higher rate (3.4−7.3%) than suggested previously. Using analysis and simulations we show that our inference is more powerful than previous summary statistics and robust to realistic levels of recombination. PMID:24532731
NASA Astrophysics Data System (ADS)
Schneebeli, L.; Kira, M.; Koch, S. W.
2008-08-01
It is shown that spectrally resolved photon-statistics measurements of the resonance fluorescence from realistic semiconductor quantum-dot systems allow for high contrast identification of the two-photon strong-coupling states. Using a microscopic theory, the second-rung resonance of Jaynes-Cummings ladder is analyzed and optimum excitation conditions are determined. The computed photon-statistics spectrum displays gigantic, experimentally robust resonances at the energetic positions of the second-rung emission.
Survey of pediatricians' opinions on donation after cardiac death: are the donors dead?
Joffe, Ari R; Anton, Natalie R; deCaen, Allan R
2008-11-01
There has been debate in the ethics literature as to whether the donation-after-cardiac-death donor is dead after 5 minutes of absent circulation. We set out to determine whether pediatricians consider the donation-after-cardiac-death donor as dead. A survey was mailed to all 147 pediatricians who are affiliated with the university teaching children's hospital. The survey had 4 pediatric patient scenarios in which a decision was made to donate organs after 5 minutes of absent circulation. Background information described the organ shortage, and the debate about the term "irreversibility" applied to death in donation after cardiac death. Descriptive statistics were used, with responses between groups compared by using the chi(2) statistic. The response rate was 54% (80 of 147). In each scenario, when given a patient described as dead with absent circulation for 5 minutes,
Maslow and the motivation hierarchy: measuring satisfaction of the needs.
Taormina, Robert J; Gao, Jennifer H
2013-01-01
For each of the 5 needs in Maslow's motivational hierarchy (physiological, safety-security, belongingness, esteem, and self-actualization), operational definitions were developed from Maslow's theory of motivation. New measures were created based on the operational definitions (1) to assess the satisfaction of each need, (2) to assess their expected correlations (a) with each of the other needs and (b) with four social and personality measures (i.e., family support, traditional values, anxiety/worry, and life satisfaction), and (3) to test the ability of the satisfaction level of each need to statistically predict the satisfaction level of the next higher-level need. Psychometric tests of the scales conducted on questionnaire results from 386 adult respondents from the general population lent strong support for the validity and reliability of all 5 needs measures. Significant positive correlations among the scales were also found; that is, the more each lower-level need was satisfied, the more the next higher-level need was satisfied. Additionally, as predicted, family support, traditional values, and life satisfaction had significant positive correlations with the satisfaction of all 5 needs, and the anxiety/worry facet of neuroticism had significant negative correlations with the satisfaction of all the needs. Multiple regression analyses revealed that the satisfaction of each higher-level need was statistically predicted by the satisfaction of the need immediately below it in the hierarchy, as expected from Maslow's theory.
Strong claims and weak evidence: reassessing the predictive validity of the IAT.
Blanton, Hart; Jaccard, James; Klick, Jonathan; Mellers, Barbara; Mitchell, Gregory; Tetlock, Philip E
2009-05-01
The authors reanalyzed data from 2 influential studies-A. R. McConnell and J. M. Leibold and J. C. Ziegert and P. J. Hanges-that explore links between implicit bias and discriminatory behavior and that have been invoked to support strong claims about the predictive validity of the Implicit Association Test. In both of these studies, the inclusion of race Implicit Association Test scores in regression models reduced prediction errors by only tiny amounts, and Implicit Association Test scores did not permit prediction of individual-level behaviors. Furthermore, the results were not robust when the impact of rater reliability, statistical specifications, and/or outliers were taken into account, and reanalysis of A. R. McConnell & J. M. Leibold (2001) revealed a pattern of behavior consistent with a pro-Black behavioral bias, rather than the anti-Black bias suggested in the original study. (c) 2009 APA, all rights reserved.
Predictable transcriptome evolution in the convergent and complex bioluminescent organs of squid
Pankey, M. Sabrina; Minin, Vladimir N.; Imholte, Greg C.; Suchard, Marc A.; Oakley, Todd H.
2014-01-01
Despite contingency in life’s history, the similarity of evolutionarily convergent traits may represent predictable solutions to common conditions. However, the extent to which overall gene expression levels (transcriptomes) underlying convergent traits are themselves convergent remains largely unexplored. Here, we show strong statistical support for convergent evolutionary origins and massively parallel evolution of the entire transcriptomes in symbiotic bioluminescent organs (bacterial photophores) from two divergent squid species. The gene expression similarities are so strong that regression models of one species’ photophore can predict organ identity of a distantly related photophore from gene expression levels alone. Our results point to widespread parallel changes in gene expression evolution associated with convergent origins of complex organs. Therefore, predictable solutions may drive not only the evolution of novel, complex organs but also the evolution of overall gene expression levels that underlie them. PMID:25336755
Analytical modeling for heat transfer in sheared flows of nanofluids.
Ferrari, Claudio; Kaoui, Badr; L'vov, Victor S; Procaccia, Itamar; Rudenko, Oleksii; ten Thije Boonkkamp, J H M; Toschi, Federico
2012-07-01
We developed a model for the enhancement of the heat flux by spherical and elongated nanoparticles in sheared laminar flows of nanofluids. Besides the heat flux carried by the nanoparticles, the model accounts for the contribution of their rotation to the heat flux inside and outside the particles. The rotation of the nanoparticles has a twofold effect: it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations. These dynamical effects, which were not included in existing thermal models, are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids. The proposed model is strongly supported by extensive numerical simulations, demonstrating a potential increase of the heat flux far beyond the Maxwell-Garnett limit for the spherical nanoparticles. The road ahead, which should lead toward robust predictive models of heat flux enhancement, is discussed.
Groothuis, Ton G G; McManus, I C; Schaafsma, Sara M; Geuze, Reint H
2013-06-01
The strong population bias in hand preference in favor of right-handedness seems to be a typical human trait. An elegant evolutionary hypothesis explaining this trait is the so-called fighting hypothesis that postulates that left-handedness is under frequency-dependent selection. The fighting hypothesis assumes that left-handers, being in the minority because of health issues, are still maintained in the population since they would have a greater chance of winning in fights than right-handers due to a surprise effect. This review critically evaluates the assumptions and evidence for this hypothesis and concludes that some evidence, although consistent with the fighting hypothesis, does not directly support it and may also be interpreted differently. Other supportive data are ambiguous or open for both statistical and theoretical criticism. We conclude that, presently, evidence for the fighting hypothesis is not particularly strong, but that there is little evidence to reject it either. The hypothesis thus remains an intuitively plausible explanation for the persistent left-hand preference in the population. We suggest alternative explanations and several ways forward for obtaining more crucial data for testing this frequently cited hypothesis. © 2013 New York Academy of Sciences.
Historical trends in U.S. mineral statistics for selected non-ferrous metals
Piper, David Z.; Nokleberg, Warren J.
2002-01-01
Production figures for selected nonferrous metals-aluminum (including bauxite and alumina), copper, lead, tin, titanium, and zinc-by the United States, as well as other statistics for these commodities, show strong volatility during 20th century. Major shifts were driven by the Great Depression and the two World Wars, but other major temporal changes are also noted that are not directly related to such global crises. For example, the price of tin exhibited a strong maximum in the 1980's, which is unrelated to world production, but rather to failed efforts of the International Tin Council to control price. In the case of copper, U.S. exports have varied throughout the second half of the century, by more than a factor of 5. Such volatility might be explained in part by global economic conditions, at least throughout recent decades. Supporting the interpretation of the importance of foreign pressure on the domestic commodities market is a close correlation between domestic consumption of antimony and its elevated price in the mid 1980's,possibly pushed up mostly by the world dominance in production of this commodity by China. However, only very superficial explanations can be advanced for such relations before we have examined, in concert, information for a much larger suite of commodities.
Das, Shibsankar; Roymondal, Uttam; Sahoo, Satyabrata
2009-08-15
Based on the hypothesis that highly expressed genes are often characterized by strong compositional bias in terms of codon usage, there are a number of measures currently in use that quantify codon usage bias in genes, and hence provide numerical indices to predict the expression levels of genes. With the recent advent of expression measure from the score of the relative codon usage bias (RCBS), we have explicitly tested the performance of this numerical measure to predict the gene expression level and illustrate this with an analysis of Yeast genomes. In contradiction with previous other studies, we observe a weak correlations between GC content and RCBS, but a selective pressure on the codon preferences in highly expressed genes. The assertion that the expression of a given gene depends on the score of relative codon usage bias (RCBS) is supported by the data. We further observe a strong correlation between RCBS and protein length indicating natural selection in favour of shorter genes to be expressed at higher level. We also attempt a statistical analysis to assess the strength of relative codon bias in genes as a guide to their likely expression level, suggesting a decrease of the informational entropy in the highly expressed genes.
Monden, Rei; de Vos, Stijn; Morey, Richard; Wagenmakers, Eric-Jan; de Jonge, Peter; Roest, Annelieke M
2016-12-01
The Food and Drug Administration (FDA) uses a p < 0.05 null-hypothesis significance testing framework to evaluate "substantial evidence" for drug efficacy. This framework only allows dichotomous conclusions and does not quantify the strength of evidence supporting efficacy. The efficacy of FDA-approved antidepressants for the treatment of anxiety disorders was re-evaluated in a Bayesian framework that quantifies the strength of the evidence. Data from 58 double-blind placebo-controlled trials were retrieved from the FDA for the second-generation antidepressants for the treatment of anxiety disorders. Bayes factors (BFs) were calculated for all treatment arms compared to placebo and were compared with the corresponding p-values and the FDA conclusion categories. BFs ranged from 0.07 to 131,400, indicating a range of no support of evidence to strong evidence for the efficacy. Results also indicate a varying strength of evidence between the trials with p < 0.05. In sum, there were large differences in BFs across trials. Among trials providing "substantial evidence" according to the FDA, only 27 out of 59 dose groups obtained strong support for efficacy according to the typically used cutoff of BF ≥ 20. The Bayesian framework can provide valuable information on the strength of the evidence for drug efficacy. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Bipolarons in one-dimensional extended Peierls-Hubbard models
NASA Astrophysics Data System (ADS)
Sous, John; Chakraborty, Monodeep; Krems, Roman; Berciu, Mona
2017-04-01
We study two particles in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/Su-Schrieffer-Heeger (SSH) model. In the case of hard-core bare particles, we show that exchange of phonons generates effective nearest-neighbor repulsion between particles and also gives rise to interactions that move the pair as a whole. The two-polaron phase diagram exhibits two sharp transitions, leading to light dimers at strong coupling and the flattening of the dimer dispersion at some critical values of the parameters. This dimer (quasi)self-trapping occurs at coupling strengths where single polarons are mobile. On the other hand, in the case of soft-core particles/ spinfull fermions, we show that phonon-mediated interactions are attractive and result in strongly bound and mobile bipolarons in a wide region of parameter space. This illustrates that, depending on the strength of the phonon-mediated interactions and statistics of bare particles, the coupling to phonons may completely suppress or strongly enhance quantum transport of correlated particles. This work was supported by NSERC of Canada and the Stewart Blusson Quantum Matter Institute.
NASA Astrophysics Data System (ADS)
Kang, Jee Sun Emily
This study explored how inquiry-based teaching and learning processes occurred in two teachers' diverse 8th grade Physical Science classrooms in a Program Improvement junior high school within the context of high-stakes standardized testing. Instructors for the courses examined included not only the two 8th grade science teachers, but also graduate fellows from a nearby university. Research was drawn from inquiry-based instruction in science education, the achievement gap, and the high stakes testing movement, as well as situated learning theory to understand how opportunities for inquiry were negotiated within the diverse classroom context. Transcripts of taped class sessions; student work samples; interviews of teachers and students; and scores from the California Standards Test in science were collected and analyzed. Findings indicated that the teachers provided structured inquiry in order to support their students in learning about forces and to prepare them for the standardized test. Teachers also supported students in generating evidence-based explanations, connecting inquiry-based investigations with content on forces, proficiently using science vocabulary, and connecting concepts about forces to their daily lives. Findings from classroom data revealed constraints to student learning: students' limited language proficiency, peer counter culture, and limited time. Supports were evidenced as well: graduate fellows' support during investigations, teachers' guided questioning, standardized test preparation, literacy support, and home-school connections. There was no statistical difference in achievement on the Forces Unit test or science standardized test between classes with graduate fellows and without fellows. There was also no statistical difference in student performance between the two teachers' classrooms, even though their teaching styles were very different. However, there was a strong correlation between students' achievement on the chapter test and their achievement on the Forces portion of the CST. Students' English language proficiency and socioeconomic status were also strongly correlated with their achievement on the standardized test. Notwithstanding the constraints of standardized testing, the teachers had students practice the heart of inquiry -- to connect evidence with explanations and process with content. Engaging in inquiry-based instruction provided a context for students, even English language learners, to demonstrate their knowledge of forces. Students had stronger and more detailed ideas about concepts when they engaged in activities that were tightly connected to the concepts, as well as to their lives and experiences.
ERIC Educational Resources Information Center
Perepiczka, Michelle; Chandler, Nichelle; Becerra, Michael
2011-01-01
Statistics plays an integral role in graduate programs. However, numerous intra- and interpersonal factors may lead to successful completion of needed coursework in this area. The authors examined the extent of the relationship between self-efficacy to learn statistics and statistics anxiety, attitude towards statistics, and social support of 166…
Phi Index: A New Metric to Test the Flush Early and Avoid the Rush Hypothesis
Samia, Diogo S. M.; Blumstein, Daniel T.
2014-01-01
Optimal escape theory states that animals should counterbalance the costs and benefits of flight when escaping from a potential predator. However, in apparent contradiction with this well-established optimality model, birds and mammals generally initiate escape soon after beginning to monitor an approaching threat, a phenomena codified as the “Flush Early and Avoid the Rush” (FEAR) hypothesis. Typically, the FEAR hypothesis is tested using correlational statistics and is supported when there is a strong relationship between the distance at which an individual first responds behaviorally to an approaching predator (alert distance, AD), and its flight initiation distance (the distance at which it flees the approaching predator, FID). However, such correlational statistics are both inadequate to analyze relationships constrained by an envelope (such as that in the AD-FID relationship) and are sensitive to outliers with high leverage, which can lead one to erroneous conclusions. To overcome these statistical concerns we develop the phi index (Φ), a distribution-free metric to evaluate the goodness of fit of a 1∶1 relationship in a constraint envelope (the prediction of the FEAR hypothesis). Using both simulation and empirical data, we conclude that Φ is superior to traditional correlational analyses because it explicitly tests the FEAR prediction, is robust to outliers, and it controls for the disproportionate influence of observations from large predictor values (caused by the constrained envelope in AD-FID relationship). Importantly, by analyzing the empirical data we corroborate the strong effect that alertness has on flight as stated by the FEAR hypothesis. PMID:25405872
Phi index: a new metric to test the flush early and avoid the rush hypothesis.
Samia, Diogo S M; Blumstein, Daniel T
2014-01-01
Optimal escape theory states that animals should counterbalance the costs and benefits of flight when escaping from a potential predator. However, in apparent contradiction with this well-established optimality model, birds and mammals generally initiate escape soon after beginning to monitor an approaching threat, a phenomena codified as the "Flush Early and Avoid the Rush" (FEAR) hypothesis. Typically, the FEAR hypothesis is tested using correlational statistics and is supported when there is a strong relationship between the distance at which an individual first responds behaviorally to an approaching predator (alert distance, AD), and its flight initiation distance (the distance at which it flees the approaching predator, FID). However, such correlational statistics are both inadequate to analyze relationships constrained by an envelope (such as that in the AD-FID relationship) and are sensitive to outliers with high leverage, which can lead one to erroneous conclusions. To overcome these statistical concerns we develop the phi index (Φ), a distribution-free metric to evaluate the goodness of fit of a 1:1 relationship in a constraint envelope (the prediction of the FEAR hypothesis). Using both simulation and empirical data, we conclude that Φ is superior to traditional correlational analyses because it explicitly tests the FEAR prediction, is robust to outliers, and it controls for the disproportionate influence of observations from large predictor values (caused by the constrained envelope in AD-FID relationship). Importantly, by analyzing the empirical data we corroborate the strong effect that alertness has on flight as stated by the FEAR hypothesis.
[Factors Influencing Burnout among Mothers of Children with Cerebral Palsy].
Seo, Ji Young; Lee, Hae Jin; You, Mi Ae
2017-04-01
The purpose of this study was to examine the effects of parental stress, social support, and coping behavior on burnout among mothers caring for children with cerebral palsy. Participants in this cross-sectional, descriptive study were 185 mothers who completed a self-report structured questionnaire. The data were analyzed using descriptive statistics, t-test, one-way ANOVA, correlation and multiple linear regression analyses with IBM SPSS Win 22 program. Parental stress and coping behavior were strong predictors of burnout among mothers of children with cerebral palsy. These variables explained 50.0% of the variance in burnout. Social support was not a predictor of burnout. A higher level of burnout was associated with higher levels of parental stress and lower levels of social support and coping behavior. Mothers of children with cerebral palsy are vulnerable to burnout. These results show that effective strategies for reducing parental stress and improving positive coping behavior are needed to reduce burnout in these mothers. © 2017 Korean Society of Nursing Science
Cheng, Richard K; Deng, Mario C; Tseng, Chi-hong; Shemin, Richard J; Kubak, Bernard M; MacLellan, W Robb
2012-08-01
Prior studies have identified risk factors for survival in patients with end-stage heart failure (HF) requiring left ventricular assist device (LVAD) support. However, patients with biventricular HF may represent a unique cohort. We retrospectively evaluated a consecutive cohort of 113 adult, end-stage HF patients at University of California Los Angeles Medical Center who required BIVAD support between 2000 and 2009. Survival to transplant was 66.4%, with 1-year actuarial survival of 62.8%. All patients were Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) Level 1 or 2 and received Thoratec (Pleasanton, CA) paracorporeal BIVAD as a bridge to transplant. Univariate analyses showed dialysis use, ventilator use, extracorporal membrane oxygenation use, low cardiac output, preserved LV ejection fraction (restrictive physiology), normal-to-high sodium, low platelet count, low total cholesterol, low high-density and high-density lipoprotein, low albumin, and elevated aspartate aminotransferase were associated with increased risk of death. We generated a scoring system for survival to transplant. Our final model, with age, sex, dialysis, cholesterol, ventilator, and albumin, gave a C-statistic of 0.870. A simplified system preserved a C-statistic of 0.844. Patients were divided into high-risk or highest-risk groups (median respective survival, 367 and 17 days), with strong discrimination between groups for death. We have generated a scoring system that offers high prognostic ability for patients requiring BIVAD support and hope that it may assist in clinical decision making. Further studies are needed to prospectively validate our scoring system. Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.
The role of supervisor emotional support on individual job satisfaction: A multilevel analysis.
Pohl, Sabine; Galletta, Maura
2017-02-01
Supervisor emotional support is a strong determinant of job satisfaction. There is no study examining the effect of supervisor emotional support at the group level on job satisfaction. Multilevel statistical techniques can help disentangle the effects of subjective assessments from those of group factors. The study's aim was to examine the moderating role of supervisor emotional support (group-level variable) on the relationship between work engagement and job satisfaction (individual-level variables). A cross-sectional study was performed in 39units from three Belgian hospitals. A total of 323 nurses completed a self-reported questionnaire. We carried out a multilevel analysis by using Hierarchical Linear Modeling. The results showed that the cross-level interaction was significant. Hence, at individual-level, the nurses with high levels of work engagement showed high levels of job satisfaction and this relationship was stronger when supervisor emotional support at group-level was high. Contextual differences among groups had an impact on the form of the work engagement-job satisfaction relationship. This relationship between work engagement and job satisfaction is an individual and group level phenomenon. Ways to enhance emotional supervisor support include training supervisors in providing support and enhancing communication between nurses and supervisors. Copyright © 2016 Elsevier Inc. All rights reserved.
Statistical universals reveal the structures and functions of human music.
Savage, Patrick E; Brown, Steven; Sakai, Emi; Currie, Thomas E
2015-07-21
Music has been called "the universal language of mankind." Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation.
Exact goodness-of-fit tests for Markov chains.
Besag, J; Mondal, D
2013-06-01
Goodness-of-fit tests are useful in assessing whether a statistical model is consistent with available data. However, the usual χ² asymptotics often fail, either because of the paucity of the data or because a nonstandard test statistic is of interest. In this article, we describe exact goodness-of-fit tests for first- and higher order Markov chains, with particular attention given to time-reversible ones. The tests are obtained by conditioning on the sufficient statistics for the transition probabilities and are implemented by simple Monte Carlo sampling or by Markov chain Monte Carlo. They apply both to single and to multiple sequences and allow a free choice of test statistic. Three examples are given. The first concerns multiple sequences of dry and wet January days for the years 1948-1983 at Snoqualmie Falls, Washington State, and suggests that standard analysis may be misleading. The second one is for a four-state DNA sequence and lends support to the original conclusion that a second-order Markov chain provides an adequate fit to the data. The last one is six-state atomistic data arising in molecular conformational dynamics simulation of solvated alanine dipeptide and points to strong evidence against a first-order reversible Markov chain at 6 picosecond time steps. © 2013, The International Biometric Society.
Statistical universals reveal the structures and functions of human music
Savage, Patrick E.; Brown, Steven; Sakai, Emi; Currie, Thomas E.
2015-01-01
Music has been called “the universal language of mankind.” Although contemporary theories of music evolution often invoke various musical universals, the existence of such universals has been disputed for decades and has never been empirically demonstrated. Here we combine a music-classification scheme with statistical analyses, including phylogenetic comparative methods, to examine a well-sampled global set of 304 music recordings. Our analyses reveal no absolute universals but strong support for many statistical universals that are consistent across all nine geographic regions sampled. These universals include 18 musical features that are common individually as well as a network of 10 features that are commonly associated with one another. They span not only features related to pitch and rhythm that are often cited as putative universals but also rarely cited domains including performance style and social context. These cross-cultural structural regularities of human music may relate to roles in facilitating group coordination and cohesion, as exemplified by the universal tendency to sing, play percussion instruments, and dance to simple, repetitive music in groups. Our findings highlight the need for scientists studying music evolution to expand the range of musical cultures and musical features under consideration. The statistical universals we identified represent important candidates for future investigation. PMID:26124105
Argo workstation: a key component of operational oceanography
NASA Astrophysics Data System (ADS)
Dong, Mingmei; Xu, Shanshan; Miao, Qingsheng; Yue, Xinyang; Lu, Jiawei; Yang, Yang
2018-02-01
Operational oceanography requires the quantity, quality, and availability of data set and the timeliness and effectiveness of data products. Without steady and strong operational system supporting, operational oceanography will never be proceeded far. In this paper we describe an integrated platform named Argo Workstation. It operates as a data processing and management system, capable of data collection, automatic data quality control, visualized data check, statistical data search and data service. After it is set up, Argo workstation provides global high quality Argo data to users every day timely and effectively. It has not only played a key role in operational oceanography but also set up an example for operational system.
On the correlation of angular position with time of occurrence of gamma-ray bursts
NASA Technical Reports Server (NTRS)
Petrosian, Vahe; Efron, Bradley
1995-01-01
Evidence indicating that a large fraction of gamma-ray bursts are repeaters would provide strong support for noncosmological origin of these sources. Wang & Lingenfelter have claimed existance of a correlation between angular position and time of occurrence of bursts. We perform statistical tests and find a marginal evidence for nearby bursts occurring within 4 to 5 days of each other in the BATSE 1B catalog. This evidence is present also in the 2B catalogs, which in addition, shows some marginal evidence for bursts repetition at longer time delays up to the total length of the observations.
Burr, Hermann; Hasselhorn, Hans Martin; Kersten, Norbert; Pohrt, Anne; Rugulies, Reiner
2017-09-01
Objectives Few epidemiological studies have examined whether associations of psychosocial working conditions with risk of poor health differ by age. Based on results from mostly cross-sectional studies, we test whether (i) psychosocial relational factors (social support) are more strongly associated with declining health of older than younger employees and (ii) psychosocial job factors (workpace, influence, possibilities for development) are more strongly associated with declining health of younger than older employees. Methods We extracted two cohorts from the Danish Work Environment Cohort Study (DWECS): the 2000-2005 and 2005-2010 cohorts. The participating 5281 employees with good self-rated health (SRH) at baseline were observed in 6585 5-year time windows. Using log-binomial regression analyses, we analysed whether psychosocial factors at work predicted 5-year deterioration of SRH. Effect modification by age was estimated by calculating relative excess risk due to interaction (RERI). Results High workpace among men, low influence at work as well as low social support from colleagues among women, and low possibilities for development and low social support from supervisors among both genders predicted 5-year decline in SRH. Of the 20 interaction analyses, only 1 was statistically significant and in the opposite direction of what was hypothesized (higher risk for declining SRH among middle-aged men with low possibilities for development compared to the young men with high possibilities for development). Conclusions Psychosocial working conditions predicted decline in SRH in this 5-year follow-up study. The model did not support our hypotheses about modifying effects by age.
NASA Astrophysics Data System (ADS)
Poulos, M. J.; Pierce, J. L.; McNamara, J. P.; Flores, A. N.; Benner, S. G.
2015-12-01
Terrain aspect alters the spatial distribution of insolation across topography, driving eco-pedo-hydro-geomorphic feedbacks that can alter landform evolution and result in valley asymmetries for a suite of land surface characteristics (e.g. slope length and steepness, vegetation, soil properties, and drainage development). Asymmetric valleys serve as natural laboratories for studying how landscapes respond to climate perturbation. In the semi-arid montane granodioritic terrain of the Idaho batholith, Northern Rocky Mountains, USA, prior works indicate that reduced insolation on northern (pole-facing) aspects prolongs snow pack persistence, and is associated with thicker, finer-grained soils, that retain more water, prolong the growing season, support coniferous forest rather than sagebrush steppe ecosystems, stabilize slopes at steeper angles, and produce sparser drainage networks. We hypothesize that the primary drivers of valley asymmetry development are changes in the pedon-scale water-balance that coalesce to alter catchment-scale runoff and drainage development, and ultimately cause the divide between north and south-facing land surfaces to migrate northward. We explore this conceptual framework by coupling land surface analyses with statistical modeling to assess relationships and the relative importance of land surface characteristics. Throughout the Idaho batholith, we systematically mapped and tabulated various statistical measures of landforms, land cover, and hydroclimate within discrete valley segments (n=~10,000). We developed a random forest based statistical model to predict valley slope asymmetry based upon numerous measures (n>300) of landscape asymmetries. Preliminary results suggest that drainages are tightly coupled with hillslopes throughout the region, with drainage-network slope being one of the strongest predictors of land-surface-averaged slope asymmetry. When slope-related statistics are excluded, due to possible autocorrelation, valley slope asymmetry is most strongly predicted by asymmetries of insolation and drainage density, which generally supports a water-balance based conceptual model of valley asymmetry development. Surprisingly, vegetation asymmetries had relatively low predictive importance.
Streicher, Jeffrey W; Schulte, James A; Wiens, John J
2016-01-01
Targeted sequence capture is becoming a widespread tool for generating large phylogenomic data sets to address difficult phylogenetic problems. However, this methodology often generates data sets in which increasing the number of taxa and loci increases amounts of missing data. Thus, a fundamental (but still unresolved) question is whether sampling should be designed to maximize sampling of taxa or genes, or to minimize the inclusion of missing data cells. Here, we explore this question for an ancient, rapid radiation of lizards, the pleurodont iguanians. Pleurodonts include many well-known clades (e.g., anoles, basilisks, iguanas, and spiny lizards) but relationships among families have proven difficult to resolve strongly and consistently using traditional sequencing approaches. We generated up to 4921 ultraconserved elements with sampling strategies including 16, 29, and 44 taxa, from 1179 to approximately 2.4 million characters per matrix and approximately 30% to 60% total missing data. We then compared mean branch support for interfamilial relationships under these 15 different sampling strategies for both concatenated (maximum likelihood) and species tree (NJst) approaches (after showing that mean branch support appears to be related to accuracy). We found that both approaches had the highest support when including loci with up to 50% missing taxa (matrices with ~40-55% missing data overall). Thus, our results show that simply excluding all missing data may be highly problematic as the primary guiding principle for the inclusion or exclusion of taxa and genes. The optimal strategy was somewhat different for each approach, a pattern that has not been shown previously. For concatenated analyses, branch support was maximized when including many taxa (44) but fewer characters (1.1 million). For species-tree analyses, branch support was maximized with minimal taxon sampling (16) but many loci (4789 of 4921). We also show that the choice of these sampling strategies can be critically important for phylogenomic analyses, since some strategies lead to demonstrably incorrect inferences (using the same method) that have strong statistical support. Our preferred estimate provides strong support for most interfamilial relationships in this important but phylogenetically challenging group. © The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Medical students' attitudes towards science and gross anatomy, and the relationship to personality
Plaisant, Odile; Stephens, Shiby; Apaydin, Nihal; Courtois, Robert; Lignier, Baptiste; Loukas, Marios; Moxham, Bernard
2014-01-01
Assessment of the personalities of medical students can enable medical educators to formulate strategies for the best development of academic and clinical competencies. Previous research has shown that medical students do not share a common personality profile, there being gender differences. We have also shown that, for French medical students, students with personality traits associated with strong competitiveness are selected for admission to medical school. In this study, we further show that the medical students have different personality profiles compared with other student groups (psychology and business studies). The main purpose of the present investigation was to assess attitudes to science and gross anatomy, and to relate these to the students' personalities. Questionnaires (including Thurstone and Chave analyses) were employed to measure attitudes, and personality was assessed using the Big Five Inventory (BFI). Data for attitudes were obtained for students at medical schools in Cardiff (UK), Paris, Descartes/Sorbonne (France), St George's University (Grenada) and Ankara (Turkey). Data obtained from personality tests were available for analysis from the Parisian cohort of students. Although the medical students were found to have strongly supportive views concerning the importance of science in medicine, their knowledge of the scientific method/philosophy of science was poor. Following analyses of the BFI in the French students, ‘openness’ and ‘conscientiousness’ were linked statistically with a positive attitude towards science. For anatomy, again strongly supportive views concerning the subject's importance in medicine were discerned. Analyses of the BFI in the French students did not show links statistically between personality profiles and attitudes towards gross anatomy, except male students with ‘negative affectivity’ showed less appreciation of the importance of anatomy. This contrasts with our earlier studies that showed that there is a relationship between the BF dimensions of personality traits and anxiety towards the dissection room experience (at the start of the course, ‘negative emotionality’ was related to an increased level of anxiety). We conclude that medical students agree on the importance to their studies of both science in general and gross anatomy in particular, and that some personality traits relate to their attitudes that could affect clinical competence. PMID:23594196
Medical students' attitudes towards science and gross anatomy, and the relationship to personality.
Plaisant, Odile; Stephens, Shiby; Apaydin, Nihal; Courtois, Robert; Lignier, Baptiste; Loukas, Marios; Moxham, Bernard
2014-03-01
Assessment of the personalities of medical students can enable medical educators to formulate strategies for the best development of academic and clinical competencies. Previous research has shown that medical students do not share a common personality profile, there being gender differences. We have also shown that, for French medical students, students with personality traits associated with strong competitiveness are selected for admission to medical school. In this study, we further show that the medical students have different personality profiles compared with other student groups (psychology and business studies). The main purpose of the present investigation was to assess attitudes to science and gross anatomy, and to relate these to the students' personalities. Questionnaires (including Thurstone and Chave analyses) were employed to measure attitudes, and personality was assessed using the Big Five Inventory (BFI). Data for attitudes were obtained for students at medical schools in Cardiff (UK), Paris, Descartes/Sorbonne (France), St George's University (Grenada) and Ankara (Turkey). Data obtained from personality tests were available for analysis from the Parisian cohort of students. Although the medical students were found to have strongly supportive views concerning the importance of science in medicine, their knowledge of the scientific method/philosophy of science was poor. Following analyses of the BFI in the French students, 'openness' and 'conscientiousness' were linked statistically with a positive attitude towards science. For anatomy, again strongly supportive views concerning the subject's importance in medicine were discerned. Analyses of the BFI in the French students did not show links statistically between personality profiles and attitudes towards gross anatomy, except male students with 'negative affectivity' showed less appreciation of the importance of anatomy. This contrasts with our earlier studies that showed that there is a relationship between the BF dimensions of personality traits and anxiety towards the dissection room experience (at the start of the course, 'negative emotionality' was related to an increased level of anxiety). We conclude that medical students agree on the importance to their studies of both science in general and gross anatomy in particular, and that some personality traits relate to their attitudes that could affect clinical competence. © 2013 Anatomical Society.
NASA Astrophysics Data System (ADS)
Hendikawati, P.; Dewi, N. R.
2017-04-01
Statistics needed for use in the data analysis process and had a comprehensive implementation in daily life so that students must master the well statistical material. The use of Statistics textbook support with ICT and portfolio assessment approach was expected to help the students to improve mathematical connection skills. The subject of this research was 30 student teachers who take Statistics courses. The results of this research are the use of Statistics textbook support with ICT and portfolio assessment approach can improve students mathematical connection skills.
ERIC Educational Resources Information Center
Nolan, Meaghan M.; Beran, Tanya; Hecker, Kent G.
2012-01-01
Students with positive attitudes toward statistics are likely to show strong academic performance in statistics courses. Multiple surveys measuring students' attitudes toward statistics exist; however, a comparison of the validity and reliability of interpretations based on their scores is needed. A systematic review of relevant electronic…
Barber, Julie A; Thompson, Simon G
1998-01-01
Objective To review critically the statistical methods used for health economic evaluations in randomised controlled trials where an estimate of cost is available for each patient in the study. Design Survey of published randomised trials including an economic evaluation with cost values suitable for statistical analysis; 45 such trials published in 1995 were identified from Medline. Main outcome measures The use of statistical methods for cost data was assessed in terms of the descriptive statistics reported, use of statistical inference, and whether the reported conclusions were justified. Results Although all 45 trials reviewed apparently had cost data for each patient, only 9 (20%) reported adequate measures of variability for these data and only 25 (56%) gave results of statistical tests or a measure of precision for the comparison of costs between the randomised groups. Only 16 (36%) of the articles gave conclusions which were justified on the basis of results presented in the paper. No paper reported sample size calculations for costs. Conclusions The analysis and interpretation of cost data from published trials reveal a lack of statistical awareness. Strong and potentially misleading conclusions about the relative costs of alternative therapies have often been reported in the absence of supporting statistical evidence. Improvements in the analysis and reporting of health economic assessments are urgently required. Health economic guidelines need to be revised to incorporate more detailed statistical advice. Key messagesHealth economic evaluations required for important healthcare policy decisions are often carried out in randomised controlled trialsA review of such published economic evaluations assessed whether statistical methods for cost outcomes have been appropriately used and interpretedFew publications presented adequate descriptive information for costs or performed appropriate statistical analysesIn at least two thirds of the papers, the main conclusions regarding costs were not justifiedThe analysis and reporting of health economic assessments within randomised controlled trials urgently need improving PMID:9794854
Schröder, Christiane; Bleidorn, Christoph; Hartmann, Stefanie; Tiedemann, Ralph
2009-12-15
Investigating the dog genome we found 178965 introns with a moderate length of 200-1000 bp. A screening of these sequences against 23 different repeat libraries to find insertions of short interspersed elements (SINEs) detected 45276 SINEs. Virtually all of these SINEs (98%) belong to the tRNA-derived Can-SINE family. Can-SINEs arose about 55 million years ago before Carnivora split into two basal groups, the Caniformia (dog-like carnivores) and the Feliformia (cat-like carnivores). Genome comparisons of dog and cat recovered 506 putatively informative SINE loci for caniformian phylogeny. In this study we show how to use such genome information of model organisms to research the phylogeny of related non-model species of interest. Investigating a dataset including representatives of all major caniformian lineages, we analysed 24 randomly chosen loci for 22 taxa. All loci were amplifiable and revealed 17 parsimony-informative SINE insertions. The screening for informative SINE insertions yields a large amount of sequence information, in particular of introns, which contain reliable phylogenetic information as well. A phylogenetic analysis of intron- and SINE sequence data provided a statistically robust phylogeny which is congruent with the absence/presence pattern of our SINE markers. This phylogeny strongly supports a sistergroup relationship of Musteloidea and Pinnipedia. Within Pinnipedia, we see strong support from bootstrapping and the presence of a SINE insertion for a sistergroup relationship of the walrus with the Otariidae.
Andrade, Fernando H
2013-12-01
Research explaining school effects on alcohol use is scare. This study examined the interactive effect between family support and school characteristics (size, poverty, and sector) on adolescents' alcohol use trajectories in Chicago. Longitudinal and multilevel data were from the Project of Human Development in Chicago Neighborhoods and the Common Core of Data (National Center for Educational Statistics). The sample consisted of 2205 adolescents in 558 schools. A three-level hierarchical linear model was used to estimate multilevel growth curve models and school effects on alcohol trajectories. In addition to the strong relationship between parental support and alcohol trajectories; the results also found school effects on the average baseline of alcohol use and the rates of change across time. Interestingly, high levels of parental support were more effective in preventing alcohol use in public schools, while adolescents attending private schools with low levels of parental support were more likely to consume alcohol. Similarly, students attending public schools with higher rates of poverty who enjoy higher levels of parental support were less likely to consume alcohol compared to students with lower parental support attending lower rates of schools poverty. Key findings highlight the importance of the interaction between parental support and school characteristics meaning that protective factors provided by parents could be reinforced or diminished by the school context. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Andrade, Fernando H.
2013-01-01
Background Research explaining school effects on alcohol use is scare. This study examined the interactive effect between family support and school characteristics (size, poverty, and sector) on adolescents alcohol use trajectories in Chicago. Methods Longitudinal and multilevel data were from the Project of Human Development in Chicago Neighborhoods and the Common Core of Data (National Center for Educational Statistics). The sample consisted of 2205 adolescents in 558 schools. A three-level hierarchical linear model was used to estimate multilevel growth curve models and school effects on alcohol trajectories. Results In addition to the strong relationship between parental support and alcohol trajectories; the results also found school effects on the average baseline of alcohol use and the rates of change across time. Interestingly, high levels of parental support were more effective in preventing alcohol use in public schools, while adolescents attending private schools with low levels of parental support were more likely to consume alcohol. Similarly, students attending public schools with higher rates of poverty who enjoy higher levels of parental support were less likely to consume alcohol compared to students with lower parental support attending lower rates of schools poverty. Conclusion Key findings highlight the importance of the interaction between parental support and school characteristics meaning that protective factors provided by parents could be reinforced or diminished by the school context. PMID:23891034
DETECTING UNSPECIFIED STRUCTURE IN LOW-COUNT IMAGES
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stein, Nathan M.; Dyk, David A. van; Kashyap, Vinay L.
Unexpected structure in images of astronomical sources often presents itself upon visual inspection of the image, but such apparent structure may either correspond to true features in the source or be due to noise in the data. This paper presents a method for testing whether inferred structure in an image with Poisson noise represents a significant departure from a baseline (null) model of the image. To infer image structure, we conduct a Bayesian analysis of a full model that uses a multiscale component to allow flexible departures from the posited null model. As a test statistic, we use a tailmore » probability of the posterior distribution under the full model. This choice of test statistic allows us to estimate a computationally efficient upper bound on a p-value that enables us to draw strong conclusions even when there are limited computational resources that can be devoted to simulations under the null model. We demonstrate the statistical performance of our method on simulated images. Applying our method to an X-ray image of the quasar 0730+257, we find significant evidence against the null model of a single point source and uniform background, lending support to the claim of an X-ray jet.« less
Improved Test Planning and Analysis Through the Use of Advanced Statistical Methods
NASA Technical Reports Server (NTRS)
Green, Lawrence L.; Maxwell, Katherine A.; Glass, David E.; Vaughn, Wallace L.; Barger, Weston; Cook, Mylan
2016-01-01
The goal of this work is, through computational simulations, to provide statistically-based evidence to convince the testing community that a distributed testing approach is superior to a clustered testing approach for most situations. For clustered testing, numerous, repeated test points are acquired at a limited number of test conditions. For distributed testing, only one or a few test points are requested at many different conditions. The statistical techniques of Analysis of Variance (ANOVA), Design of Experiments (DOE) and Response Surface Methods (RSM) are applied to enable distributed test planning, data analysis and test augmentation. The D-Optimal class of DOE is used to plan an optimally efficient single- and multi-factor test. The resulting simulated test data are analyzed via ANOVA and a parametric model is constructed using RSM. Finally, ANOVA can be used to plan a second round of testing to augment the existing data set with new data points. The use of these techniques is demonstrated through several illustrative examples. To date, many thousands of comparisons have been performed and the results strongly support the conclusion that the distributed testing approach outperforms the clustered testing approach.
Nakagami, Eri; Xie, Bin; Hoe, Maanse; Brekke, John S
2008-10-01
This study examined the nature of the relationships among neurocognition, intrinsic motivation, and psychosocial functioning for persons with schizophrenia. Hypotheses concerning both mediator and moderator mechanisms were tested. 120 individuals diagnosed with schizophrenia were recruited as they entered outpatient psychosocial rehabilitation programs. Measures of psychosocial functioning and intrinsic motivation were administered at baseline. Measures of neurocognition were administered at baseline by testers blind to scores on other study variables. Data were analyzed using latent construct modeling to test for mediator and moderator effects. There were strong bivariate relationships between neurocognition, intrinsic motivation, and psychosocial functioning. The results demonstrated that intrinsic motivation strongly mediated the relationship between neurocognition and psychosocial functioning. This mediation was evidenced by: (i) the direct path from neurocognition to functional outcome no longer being statistically significant after the introduction of motivation into the model, (ii) the statistical significance of the indirect path from neurocognition through motivation to functional outcome. There was no support for the two moderation hypotheses: the level of neurocognition did not influence the relationship between intrinsic motivation and psychosocial functioning, nor did the level of intrinsic motivation influence the relationship between neurocognition and psychosocial functioning. Neurocognition influences psychosocial functioning through its relationship with intrinsic motivation. Intrinsic motivation is a critical mechanism for explaining the relationship between neurocognition and psychosocial functioning. Implications for the theoretical understanding and psychosocial treatment of intrinsic motivation in schizophrenia are discussed.
Inbreeding depression by environment interactions in a free-living mammal population
Pemberton, J M; Ellis, P E; Pilkington, J G; Bérénos, C
2017-01-01
Experimental studies often find that inbreeding depression is more severe in harsh environments, but the few studies of in situ wild populations available to date rarely find strong support for this effect. We investigated evidence for inbreeding depression by environment interactions in nine traits in the individually monitored Soay sheep population of St Kilda, using genomic inbreeding coefficients based on 37 037 single-nucleotide polymorphism loci, and population density as an axis of environmental variation. All traits showed variation with population density and all traits showed some evidence for depression because of either an individual's own inbreeding or maternal inbreeding. However, only six traits showed evidence for an interaction in the expected direction, and only two interactions were statistically significant. We identify three possible reasons why wild population studies may generally fail to find strong support for interactions between inbreeding depression and environmental variation compared with experimental studies. First, for species with biparental inbreeding only, the amount of observed inbreeding in natural populations is generally low compared with that used in experimental studies. Second, it is possible that experimental studies sometimes actually impose higher levels of stress than organisms experience in the wild. Third, some purging of the deleterious recessive alleles that underpin interaction effects may occur in the wild. PMID:27876804
Inbreeding depression by environment interactions in a free-living mammal population.
Pemberton, J M; Ellis, P E; Pilkington, J G; Bérénos, C
2017-01-01
Experimental studies often find that inbreeding depression is more severe in harsh environments, but the few studies of in situ wild populations available to date rarely find strong support for this effect. We investigated evidence for inbreeding depression by environment interactions in nine traits in the individually monitored Soay sheep population of St Kilda, using genomic inbreeding coefficients based on 37 037 single-nucleotide polymorphism loci, and population density as an axis of environmental variation. All traits showed variation with population density and all traits showed some evidence for depression because of either an individual's own inbreeding or maternal inbreeding. However, only six traits showed evidence for an interaction in the expected direction, and only two interactions were statistically significant. We identify three possible reasons why wild population studies may generally fail to find strong support for interactions between inbreeding depression and environmental variation compared with experimental studies. First, for species with biparental inbreeding only, the amount of observed inbreeding in natural populations is generally low compared with that used in experimental studies. Second, it is possible that experimental studies sometimes actually impose higher levels of stress than organisms experience in the wild. Third, some purging of the deleterious recessive alleles that underpin interaction effects may occur in the wild.
SOME APPLICATIONS OF SEISMIC SOURCE MECHANISM STUDIES TO ASSESSING UNDERGROUND HAZARD.
McGarr, A.; ,
1984-01-01
Various measures of the seismic source mechanism of mine tremors, such as magnitude, moment, stress drop, apparent stress, and seismic efficiency, can be related directly to several aspects of the problem of determining the underground hazard arising from strong ground motion of large seismic events. First, the relation between the sum of seismic moments of tremors and the volume of stope closure caused by mining during a given period can be used in conjunction with magnitude-frequency statistics and an empirical relation between moment and magnitude to estimate the maximum possible sized tremor for a given mining situation. Second, it is shown that the 'energy release rate,' a commonly-used parameter for predicting underground seismic hazard, may be misleading in that the importance of overburden stress, or depth, is overstated. Third, results involving the relation between peak velocity and magnitude, magnitude-frequency statistics, and the maximum possible magnitude are applied to the problem of estimating the frequency at which design limits of certain underground support equipment are likely to be exceeded.
NASA Astrophysics Data System (ADS)
Yuksel, Kivanc; Chang, Xin; Skarbek, Władysław
2017-08-01
The novel smile recognition algorithm is presented based on extraction of 68 facial salient points (fp68) using the ensemble of regression trees. The smile detector exploits the Support Vector Machine linear model. It is trained with few hundreds exemplar images by SVM algorithm working in 136 dimensional space. It is shown by the strict statistical data analysis that such geometric detector strongly depends on the geometry of mouth opening area, measured by triangulation of outer lip contour. To this goal two Bayesian detectors were developed and compared with SVM detector. The first uses the mouth area in 2D image, while the second refers to the mouth area in 3D animated face model. The 3D modeling is based on Candide-3 model and it is performed in real time along with three smile detectors and statistics estimators. The mouth area/Bayesian detectors exhibit high correlation with fp68/SVM detector in a range [0:8; 1:0], depending mainly on light conditions and individual features with advantage of 3D technique, especially in hard light conditions.
Feature recognition and detection for ancient architecture based on machine vision
NASA Astrophysics Data System (ADS)
Zou, Zheng; Wang, Niannian; Zhao, Peng; Zhao, Xuefeng
2018-03-01
Ancient architecture has a very high historical and artistic value. The ancient buildings have a wide variety of textures and decorative paintings, which contain a lot of historical meaning. Therefore, the research and statistics work of these different compositional and decorative features play an important role in the subsequent research. However, until recently, the statistics of those components are mainly by artificial method, which consumes a lot of labor and time, inefficiently. At present, as the strong support of big data and GPU accelerated training, machine vision with deep learning as the core has been rapidly developed and widely used in many fields. This paper proposes an idea to recognize and detect the textures, decorations and other features of ancient building based on machine vision. First, classify a large number of surface textures images of ancient building components manually as a set of samples. Then, using the convolution neural network to train the samples in order to get a classification detector. Finally verify its precision.
Compiling mortality statistics from civil registration systems in Viet Nam: the long road ahead.
Rao, Chalapati; Osterberger, Brigitta; Anh, Tran Dam; MacDonald, Malcolm; Chúc, Nguyen Thi Kim; Hill, Peter S
2010-01-01
Accurate mortality statistics, needed for population health assessment, health policy and research, are best derived from data in vital registration systems. However, mortality statistics from vital registration systems are not available for several countries including Viet Nam. We used a mixed methods case study approach to assess vital registration operations in 2006 in three provinces in Viet Nam (Hòa Bình, Thùa Thiên-Hué and Bình Duong), and provide recommendations to strengthen vital registration systems in the country. For each province we developed life tables from population and mortality data compiled by sex and age group. Demographic methods were used to estimate completeness of death registration as an indicator of vital registration performance. Qualitative methods (document review, key informant interviews and focus group discussions) were used to assess administrative, technical and societal aspects of vital registration systems. Completeness of death registration was low in all three provinces. Problems were identified with the legal framework for registration of early neonatal deaths and deaths of temporary residents or migrants. The system does not conform to international standards for reporting cause of death or for recording detailed statistics by age, sex and cause of death. Capacity-building along with an intersectoral coordination committee involving the Ministries of Justice and Health and the General Statistics Office would improve the vital registration system, especially with regard to procedures for death registration. There appears to be strong political support for sentinel surveillance systems to generate reliable mortality statistics in Viet Nam.
Factorial validity and internal consistency of the motivational climate in physical education scale.
Soini, Markus; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami; Jaakkola, Timo
2014-01-01
The aim of the study was to examine the construct validity and internal consistency of the Motivational Climate in Physical Education Scale (MCPES). A key element of the development process of the scale was establishing a theoretical framework that integrated the dimensions of task- and ego involving climates in conjunction with autonomy, and social relatedness supporting climates. These constructs were adopted from the self-determination and achievement goal theories. A sample of Finnish Grade 9 students, comprising 2,594 girls and 1,803 boys, completed the 18-item MCPES during one physical education class. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate and ego-involving climate. Additionally, autonomy, social relatedness, and task- involving climates were significantly and strongly correlated with each other, whereas the ego- involving climate had low or negligible correlations with the other climate dimensions.The construct validity of the MCPES was analyzed using confirmatory factor analysis. The statistical fit of the four-factor model consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. The results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The Motivational Climate in Physical Education Scale can be considered as psychometrically valid tool to measure motivational climate in Finnish Grade 9 students. Key PointsThis study developed Motivational Climate in School Physical Education Scale (MCPES). During the development process of the scale, the theoretical framework using dimensions of task- and ego involving as well as autonomy, and social relatedness supporting climates was constructed. These constructs were adopted from the self-determination and achievement goal theories.The statistical fit of the four-factor model of the MCPES consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. Additionally, the results of the reliability analysis showed acceptable internal consistencies for all four dimensions.The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate.Autonomy, social relatedness, and task climate were significantly and strongly correlated with each other, whereas the ego climate factor had low or negligible correlations with the other three factors.
Factorial Validity and Internal Consistency of the Motivational Climate in Physical Education Scale
Soini, Markus; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami; Jaakkola, Timo
2014-01-01
The aim of the study was to examine the construct validity and internal consistency of the Motivational Climate in Physical Education Scale (MCPES). A key element of the development process of the scale was establishing a theoretical framework that integrated the dimensions of task- and ego involving climates in conjunction with autonomy, and social relatedness supporting climates. These constructs were adopted from the self-determination and achievement goal theories. A sample of Finnish Grade 9 students, comprising 2,594 girls and 1,803 boys, completed the 18-item MCPES during one physical education class. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate and ego-involving climate. Additionally, autonomy, social relatedness, and task- involving climates were significantly and strongly correlated with each other, whereas the ego- involving climate had low or negligible correlations with the other climate dimensions.The construct validity of the MCPES was analyzed using confirmatory factor analysis. The statistical fit of the four-factor model consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. The results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The Motivational Climate in Physical Education Scale can be considered as psychometrically valid tool to measure motivational climate in Finnish Grade 9 students. Key Points This study developed Motivational Climate in School Physical Education Scale (MCPES). During the development process of the scale, the theoretical framework using dimensions of task- and ego involving as well as autonomy, and social relatedness supporting climates was constructed. These constructs were adopted from the self-determination and achievement goal theories. The statistical fit of the four-factor model of the MCPES consisting of motivational climate factors supporting perceived autonomy, social relatedness, task-involvement, and ego-involvement was satisfactory. Additionally, the results of the reliability analysis showed acceptable internal consistencies for all four dimensions. The results of the study demonstrated that participants had highest mean in task-involving climate and the lowest in autonomy climate. Autonomy, social relatedness, and task climate were significantly and strongly correlated with each other, whereas the ego climate factor had low or negligible correlations with the other three factors. PMID:24570617
NASA Astrophysics Data System (ADS)
Dondeynaz, C.; López Puga, J.; Carmona Moreno, C.
2013-02-01
Despite the efforts made towards the millennium goals targets during the last decade, access to improved water supply or basic sanitation remains still not accessible for millions of people across the world. This paper proposes a set of models that use 25 key variables from the WatSan4Dev dataset and country profiles involving Water Supply and Sanitation (Dondeynaz et al., 2012). This paper proposes the use of Bayesian Network modelling methods because adapted to the management of non-normal distribution, and integrate a qualitative approach for data analysis. They also offer the advantage to integrate preliminary knowledge into the probabilistic models. The statistical performance of the proposed models ranges between 80 and 95% which is very satisfactory taking into account the strong heterogeneity of variables. Probabilistic scenarios run from the models allow a quantification of the relationships between human development, external support, governance aspects, economic activities and Water Supply and Sanitation (WSS) access. According to models proposed in this paper, a strong poverty reduction will induce an increment of the WSS access equal to 75-76% through: (1) the organisation of on-going urbanisation process to avoid slums development; and, (2) the improvement of health care for instance for children. On one side, improving governance, such as institutional efficiency, capacities to make and apply rules or control of corruption will also have a positive impact on WSS sustainable development. The first condition for an increment of the WSS access remains of course an improvement of the economic development with an increment of household income. Moreover, a significant country environmental commitment associated with civil society freedom of expression constitutes a favourable environment for sustainable WSS services delivery. Intensive agriculture through irrigation practises also appears as a mean for sustainable WSS thanks to multi-uses and complementarities. Strong and structured agriculture sector facilitates rural development in areas where WSS access often steps behind compared to urban areas1. External financial support, named Official Development Aid (ODA), plays a role in WSS improvement but comes last in the sensitivity analyses of models. This aid supports first poor countries at 47%, and is associated to governance aspects: (1) political stability and (2) country environmental commitment and civil society degree of freedom. These governance aspects constitute a good framework for aid implementation in recipient countries. Modelling is run with the five groups of countries as defined in Dondeynaz et al. (2012). Models for profile 4 (essential external support) and profile 5 (primary material consumption) are specifically detailed and analysed in this paper. For countries in profile 4, to fight against water scarcity and desertification pressure should be the priority. However, for countries in profile 5, efforts should first concentrate on political stability consolidation while supporting economic activity diversification. Nevertheless, for both profiles, reduction of poverty should remain the first priority as previously indicated. 1 JMP statistics, 2004 http://www.wssinfo.org/data-estimates/table/
Plastino, A; Rocca, M C
2017-06-01
Appealing to the 1902 Gibbs formalism for classical statistical mechanics (SM)-the first SM axiomatic theory ever that successfully explained equilibrium thermodynamics-we show that already at the classical level there is a strong correlation between Renyi's exponent α and the number of particles for very simple systems. No reference to heat baths is needed for such a purpose.
Sokolova, Elena; Groot, Perry; Claassen, Tom; van Hulzen, Kimm J.; Glennon, Jeffrey C.; Franke, Barbara
2016-01-01
Background Numerous factor analytic studies consistently support a distinction between two symptom domains of attention-deficit/hyperactivity disorder (ADHD), inattention and hyperactivity/impulsivity. Both dimensions show high internal consistency and moderate to strong correlations with each other. However, it is not clear what drives this strong correlation. The aim of this paper is to address this issue. Method We applied a sophisticated approach for causal discovery on three independent data sets of scores of the two ADHD dimensions in NeuroIMAGE (total N = 675), ADHD-200 (N = 245), and IMpACT (N = 164), assessed by different raters and instruments, and further used information on gender or a genetic risk haplotype. Results In all data sets we found strong statistical evidence for the same pattern: the clear dependence between hyperactivity/impulsivity symptom level and an established genetic factor (either gender or risk haplotype) vanishes when one conditions upon inattention symptom level. Under reasonable assumptions, e.g., that phenotypes do not cause genotypes, a causal model that is consistent with this pattern contains a causal path from inattention to hyperactivity/impulsivity. Conclusions The robust dependency cancellation observed in three different data sets suggests that inattention is a driving factor for hyperactivity/impulsivity. This causal hypothesis can be further validated in intervention studies. Our model suggests that interventions that affect inattention will also have an effect on the level of hyperactivity/impulsivity. On the other hand, interventions that affect hyperactivity/impulsivity would not change the level of inattention. This causal model may explain earlier findings on heritable factors causing ADHD reported in the study of twins with learning difficulties. PMID:27768717
Evaluation of PCMH Model Adoption on Teamwork and Impact on Patient Access and Safety
Khanna, Niharika; Shaya, Fadia T.; Gaitonde, Priyanka; Abiamiri, Andrea; Steffen, Ben; Sharp, David
2016-01-01
Purpose: Each of the participating patient-centered medical home (PCMH) received coaching and participated in learning collaborative for improving teamwork. The objective of the study was to assess the impact of trainings on patient-centered teamwork. Methods: The Teamwork Perception Questionnaire (TPQ) was administered once in spring 2014 and then in fall 2015. The TPQ consists of 35 questions across 5 domains: mutual support, situation monitoring, communication, team structure, and leadership. Based on our objective we compared the frequencies of strongly agree/agree by domain. The difference was tested using chi-square test. We compared the scores on each domain (strongly agree/agree = 1; maximum score = 7) via Wilcoxon rank sum test. Results: The response rate for this survey was n = 29 (80.6%) in spring 2014, and n = 31 (86.1%) in fall 2015. We found that the practice members significantly (P < .05) strongly agreed/agreed more in fall 2015 than spring 2014 for characteristics—“staff relay relevant information in a timely manner” (64.5% vs 83.9%) and “staff follow a standardized method of sharing information when handing off patients” (67.7% vs 90.3%) under communication domain and for characteristic—“staff within my practice share information that enables timely decision making” (74.2% vs 90.3%). However, there was no statistical significant difference observed in the scores for the overall TPQ at the 2 time points. Conclusion: Despite the statistical insignificance, the observations in PCMHs across the spectrum of practices participating in the Maryland Multi-Payer Program demonstrated enhanced teamwork specifically in communication and in leadership. This we believe will continue to result in enhanced patient access to care and safety. PMID:27838621
Evaluation of PCMH Model Adoption on Teamwork and Impact on Patient Access and Safety.
Khanna, Niharika; Shaya, Fadia T; Gaitonde, Priyanka; Abiamiri, Andrea; Steffen, Ben; Sharp, David
2017-04-01
Each of the participating patient-centered medical home (PCMH) received coaching and participated in learning collaborative for improving teamwork. The objective of the study was to assess the impact of trainings on patient-centered teamwork. The Teamwork Perception Questionnaire (TPQ) was administered once in spring 2014 and then in fall 2015. The TPQ consists of 35 questions across 5 domains: mutual support, situation monitoring, communication, team structure, and leadership. Based on our objective we compared the frequencies of strongly agree/agree by domain. The difference was tested using chi-square test. We compared the scores on each domain (strongly agree/agree = 1; maximum score = 7) via Wilcoxon rank sum test. The response rate for this survey was n = 29 (80.6%) in spring 2014, and n = 31 (86.1%) in fall 2015. We found that the practice members significantly ( P < .05) strongly agreed/agreed more in fall 2015 than spring 2014 for characteristics-"staff relay relevant information in a timely manner" (64.5% vs 83.9%) and "staff follow a standardized method of sharing information when handing off patients" (67.7% vs 90.3%) under communication domain and for characteristic-"staff within my practice share information that enables timely decision making" (74.2% vs 90.3%). However, there was no statistical significant difference observed in the scores for the overall TPQ at the 2 time points. Despite the statistical insignificance, the observations in PCMHs across the spectrum of practices participating in the Maryland Multi-Payer Program demonstrated enhanced teamwork specifically in communication and in leadership. This we believe will continue to result in enhanced patient access to care and safety.
[Long-term results after polytrauma].
Hofman, M; Zilkens, A; Pape, H C
2011-09-01
Rehabilitation treatment, which is necessary in the majority of polytrauma patients, is long-lasting and even after several years the final result is frequently not reached yet. Our study is the first in which a population of 510 patients were followed up for 10 years and more and in which many clinical and social parameters were determined. Our study showed that even after a period of 10 years and more the quality of life in several patients is still obviously impaired, according to the parametes "financial losses", "decreased net income", "loss of social services", "credit loan" and "loss of friends". In our study, differences according to financial and professional perspectives between injuries of the lower and upper extremities or combination injuries of the extremities were statistically significant. For the everyday clinic it is important to reintegrate children and young patients into a strong social network because there is a higher percentage of young patients who are socially impaired, even many years after trauma. Adult patients should get strong support to return to their original profession and financial status.
Industry guidelines, laws and regulations ignored: quality of drug advertising in medical journals.
Lankinen, Kari S; Levola, Tero; Marttinen, Kati; Puumalainen, Inka; Helin-Salmivaara, Arja
2004-11-01
To document the quality of evidence base for marketing claims in prescription drug advertisements, to facilitate identification of potential targets for quality improvement. A sample of 1036 advertisements from four major Finnish medical journals published in 2002. Marketing claims were classified in four groups: unambiguous clinical outcome, vague clinical outcome, emotive or immeasurable outcome and non-clinical outcome. Medline references were traced and classified according to the level of evidence available. The statistical variables used in the advertisements were also documented. The sample included 245 distinct advertisements with 883 marketing claims, 1-10 claims per advertisement. Three hundred thirty seven (38%) of the claims were referenced. Each claim could be supported by one reference or more, so the number of references analysed totalled 381, 1-9 references per advertisement. Nine percent of the claims implied unambiguous clinical outcomes, 68% included vague or emotive statements. Twenty one percent of the references were irrelevant to the claim. There was a fair amount of non-scientific and scientific support for the 73 unambiguous claims, but not a single claim was supported by strong scientific evidence. Vague, emotive and non-clinical claims were significantly more often supported by non-Medline or irrelevant references than unambiguous claims. Statistical parameters were stated only 34 times. Referenced marketing claims may appear more scientific, but the use of references does not guarantee the quality of the claims. For the benefit of all stakeholders, both the regulatory control and industry's self-control of drug marketing should adopt more active monitoring roles, and apply sanctions when appropriate. Concerted efforts by several stakeholders might be more effective. Copyright 2004 John Wiley & Sons, Ltd.
Yellow Fever Virus Maintenance in Trinidad and Its Dispersal throughout the Americas▿ †
Auguste, Albert J.; Lemey, Philippe; Pybus, Oliver G.; Suchard, Marc A.; Salas, Rosa Alba; Adesiyun, Abiodun A.; Barrett, Alan D.; Tesh, Robert B.; Weaver, Scott C.; Carrington, Christine V. F.
2010-01-01
Trinidad, like many other American regions, experiences repeated epizootics of yellow fever virus (YFV). However, it is unclear whether these result from in situ evolution (enzootic maintenance) or regular reintroduction of YFV from the South American mainland. To discriminate between these hypotheses, we carried out a Bayesian phylogeographic analysis of over 100 prM/E gene sequences sampled from 8 South American countries. These included newly sequenced isolates from the recent 2008-2009 Trinidad epizootic and isolates derived from mainland countries within the last decade. The results indicate that the most recent common ancestor of the 2008-2009 epizootic existed in Trinidad 4.2 years prior to 2009 (95% highest probability density [HPD], 0.5 to 9.0 years). Our data also suggest a Trinidad origin for the progenitor of the 1995 Trinidad epizootic and support in situ evolution of YFV between the 1979 and 1988-1989 Trinidad epizootics. Using the same phylogeographic approach, we also inferred the historical spread of YFV in the Americas. The results suggest a Brazilian origin for YFV in the Americas and an overall dispersal rate of 182 km/year (95% HPD, 52 to 462 km/year), with Brazil as the major source population for surrounding countries. There is also strong statistical support for epidemiological links between four Brazilian regions and other countries. In contrast, while there were well-supported epidemiological links within Peru, the only statistically supported external link was a relatively weak link with neighboring Bolivia. Lastly, we performed a complete analysis of the genome of a newly sequenced Trinidad 2009 isolate, the first complete genome for a genotype I YFV isolate. PMID:20631128
Reicher, Joshua Jay; Reicher, Murray Aaron
2016-06-01
Since 2009, the Federal government distributed over $29 billion to providers who were adopting compliant electronic health record (EHR) technology. With a focus on radiology, we explore how EHR technology impacts interoperability with referring clinicians' EHRs and patient engagement. We also discuss the high-level details of contributing supporting frameworks, specifically Direct messaging and health information service provider (HISP) technology. We characterized Direct messaging, a secure e-mail-like protocol built to allow exchange of encrypted health information online, and the new supporting HISP infrastructure. Statistics related to both the testing and active use of this framework were obtained from DirectTrust.org, an organization whose framework supports Direct messaging use by healthcare organizations. To evaluate patient engagement, we obtained usage data from a radiology-centric patient portal between 2014 and 2015, which in some cases included access to radiology reports. Statistics from 2013 to 2015 showed a rise in issued secure Direct addresses from 8724 to 752,496; a rise in the number of participating healthcare organizations from 667 to 39,751; and a rise in the secure messages sent from 122,842 to 27,316,438. Regarding patient engagement, an average of 234,679 patients per month were provided portal access, with 86,400 patients per month given access to radiology reports. Availability of radiology reports online was strongly associated with increased system usage, with a likelihood ratio of 2.63. The use of certified EHR technology and Direct messaging in the practice of radiology allows for the communication of patient information and radiology results with referring clinicians and increases patient use of patient portal technology, supporting bidirectional radiologist-patient communication.
Yellow fever virus maintenance in Trinidad and its dispersal throughout the Americas.
Auguste, Albert J; Lemey, Philippe; Pybus, Oliver G; Suchard, Marc A; Salas, Rosa Alba; Adesiyun, Abiodun A; Barrett, Alan D; Tesh, Robert B; Weaver, Scott C; Carrington, Christine V F
2010-10-01
Trinidad, like many other American regions, experiences repeated epizootics of yellow fever virus (YFV). However, it is unclear whether these result from in situ evolution (enzootic maintenance) or regular reintroduction of YFV from the South American mainland. To discriminate between these hypotheses, we carried out a Bayesian phylogeographic analysis of over 100 prM/E gene sequences sampled from 8 South American countries. These included newly sequenced isolates from the recent 2008-2009 Trinidad epizootic and isolates derived from mainland countries within the last decade. The results indicate that the most recent common ancestor of the 2008-2009 epizootic existed in Trinidad 4.2 years prior to 2009 (95% highest probability density [HPD], 0.5 to 9.0 years). Our data also suggest a Trinidad origin for the progenitor of the 1995 Trinidad epizootic and support in situ evolution of YFV between the 1979 and 1988-1989 Trinidad epizootics. Using the same phylogeographic approach, we also inferred the historical spread of YFV in the Americas. The results suggest a Brazilian origin for YFV in the Americas and an overall dispersal rate of 182 km/year (95% HPD, 52 to 462 km/year), with Brazil as the major source population for surrounding countries. There is also strong statistical support for epidemiological links between four Brazilian regions and other countries. In contrast, while there were well-supported epidemiological links within Peru, the only statistically supported external link was a relatively weak link with neighboring Bolivia. Lastly, we performed a complete analysis of the genome of a newly sequenced Trinidad 2009 isolate, the first complete genome for a genotype I YFV isolate.
Kail, Robert V.
2013-01-01
According to dual-process models that include analytic and heuristic modes of processing, analytic processing is often expected to become more common with development. Consistent with this view, on reasoning problems, adolescents are more likely than children to select alternatives that are backed by statistical evidence. It is shown here that this pattern depends on the quality of the statistical evidence and the quality of the testimonial that is the typical alternative to statistical evidence. In Experiment 1, 9- and 13-year-olds (N = 64) were presented with scenarios in which solid statistical evidence was contrasted with casual or expert testimonial evidence. When testimony was casual, children relied on it but adolescents did not; when testimony was expert, both children and adolescents relied on it. In Experiment 2, 9- and 13-year-olds (N = 83) were presented with scenarios in which casual testimonial evidence was contrasted with weak or strong statistical evidence. When statistical evidence was weak, children and adolescents relied on both testimonial and statistical evidence; when statistical evidence was strong, most children and adolescents relied on it. Results are discussed in terms of their implications for dual-process accounts of cognitive development. PMID:23735681
Ueda, Noriyuki; Kushi, Nobutaka; Nakatsuka, Mikiya; Ogawa, Tatsuyuki; Nakanishi, Yoshiko; Shishido, Keisuke; Awaya, Tsuyoshi
2008-10-01
Posthumous reproduction has been performed in Japan several times, without sufficient civic discussion on its appropriateness or legislative regulation. There have even been several lawsuits on posthumous acknowledgment (in which a baby born to a deceased father has the same birthright as a baby born to a living father), and some judgments have proposed the need to develop societal agreement on posthumous reproduction and suggested legislative settlement. With this background, this study aims to clarify the views of the Japanese people regarding posthumous reproduction. In December 2007, we distributed a questionnaire on posthumous reproduction in relation to beliefs about family and religion to 32 universities across the country, and received 3,719 replies. It was found that about 60% of respondents agreed with posthumous reproduction. Statistical analysis was applied to the relationship between this overall position on posthumous reproduction and views on assisted reproduction technologies, family, religion, and so on. The degree of support for posthumous reproduction was strongly correlated with the degree of affirmation of assisted reproduction technologies and a liberal worldview with emphasis on self-determination. On the other hand, there was also a strong correlation with having a traditional view of family, such as family succession. The degree of support for posthumous reproduction was also highly correlated with the intimacy among family members, underlying which was a strong connection to the traditional religious belief in Japan that deceased family members watch the living ones. The view on posthumous reproduction is culturally complex and cannot be explained by a simple dichotomy between traditional conservatives and liberals.
Artés, Juan M; Díez-Pérez, Ismael; Sanz, Fausto; Gorostiza, Pau
2011-03-22
We present a method to measure directly and at the single-molecule level the distance decay constant that characterizes the rate of electron transfer (ET) in redox proteins. Using an electrochemical tunneling microscope under bipotentiostatic control, we obtained current−distance spectroscopic recordings of individual redox proteins confined within a nanometric tunneling gap at a well-defined molecular orientation. The tunneling current decays exponentially, and the corresponding decay constant (β) strongly supports a two-step tunneling ET mechanism. Statistical analysis of decay constant measurements reveals differences between the reduced and oxidized states that may be relevant to the control of ET rates in enzymes and biological electron transport chains.
NASA Astrophysics Data System (ADS)
Shemer, L.; Sergeeva, A.
2009-12-01
The statistics of random water wave field determines the probability of appearance of extremely high (freak) waves. This probability is strongly related to the spectral wave field characteristics. Laboratory investigation of the spatial variation of the random wave-field statistics for various initial conditions is thus of substantial practical importance. Unidirectional nonlinear random wave groups are investigated experimentally in the 300 m long Large Wave Channel (GWK) in Hannover, Germany, which is the biggest facility of its kind in Europe. Numerous realizations of a wave field with the prescribed frequency power spectrum, yet randomly-distributed initial phases of each harmonic, were generated by a computer-controlled piston-type wavemaker. Several initial spectral shapes with identical dominant wave length but different width were considered. For each spectral shape, the total duration of sampling in all realizations was long enough to yield sufficient sample size for reliable statistics. Through all experiments, an effort had been made to retain the characteristic wave height value and thus the degree of nonlinearity of the wave field. Spatial evolution of numerous statistical wave field parameters (skewness, kurtosis and probability distributions) is studied using about 25 wave gauges distributed along the tank. It is found that, depending on the initial spectral shape, the frequency spectrum of the wave field may undergo significant modification in the course of its evolution along the tank; the values of all statistical wave parameters are strongly related to the local spectral width. A sample of the measured wave height probability functions (scaled by the variance of surface elevation) is plotted in Fig. 1 for the initially narrow rectangular spectrum. The results in Fig. 1 resemble findings obtained in [1] for the initial Gaussian spectral shape. The probability of large waves notably surpasses that predicted by the Rayleigh distribution and is the highest at the distance of about 100 m. Acknowledgement This study is carried out in the framework of the EC supported project "Transnational access to large-scale tests in the Large Wave Channel (GWK) of Forschungszentrum Küste (Contract HYDRALAB III - No. 022441). [1] L. Shemer and A. Sergeeva, J. Geophys. Res. Oceans 114, C01015 (2009). Figure 1. Variation along the tank of the measured wave height distribution for rectangular initial spectral shape, the carrier wave period T0=1.5 s.
NASA Astrophysics Data System (ADS)
Lo, Alex Y.; Chow, Alex T.; Cheung, Sze Man
2012-11-01
The likelihood of participating in wildlife conservation programs is dependent on social influences and circumstances. This view is validated by a case study of behavioral intention to support conservation of Asian turtles. A total of 776 college students in China completed a questionnaire survey designed to identify factors associated with their intention to support conservation. A regression model explained 48 % of variance in the level of intention. Perceived social expectation was the strongest predictor, followed by attitudes toward turtle protection and perceived behavioral control, altogether explaining 44 %. Strong ethics and socio-economic variables had some statistical significant impacts and accounted for 3 % of the variance. The effects of general environmental awareness, trust and responsibility ascription were modest. Knowledge about turtles was a weak predictor. We conclude that perceived social expectation is a limiting factor of conservation behavior. Sustained interest and commitment to conservation can be created by enhancing positive social influences. Conservation educators should explore the potential of professionally supported, group-based actions that can nurture a sense of collective achievement as part of an educational campaign.
Coping, satisfaction, and the life cycle in families with mentally retarded persons.
Cullen, J C; MacLeod, J A; Williams, P D; Williams, A R
1991-01-01
The study focused on the variables influencing the functioning of 62 families with MR (mentally retarded) persons, living at home, in various stages of the life cycle. Results demonstrated the importance of some father characteristics to maternal coping skills in two-parent households. Although mean maternal coping scores were not statistically different between two-parent and single-parent households, single mothers' coping skills showed strong negative associations with both the number of children in the household and the age of the mother. This was not true of mothers in two-parent households. Single-parent mothers also appeared to be considerably more dissatisfied with family functioning than mothers in two-parent households. The supportive role of older fathers in mothers' coping in two-parent households also was apparent. Clinical implications of the study point to the need for greater support for mothers of young children with MR, mothers who are sole caregivers, and parents with many children. Differential support to mothers and fathers of an MR person may be required over the life cycle.
Clancy, Aisling A; Posner, Glenn
2015-01-01
Obstetrics and Gynecology (Ob/Gyn) residency programs in Canada mandate participation in scholarly research activity, yet there remains a lack of literature on trainees' opinions regarding its value, feasibility, and perceived effect on future practice. An understanding of resident attitudes toward research during residency is essential in effectively engaging trainees and fostering a robust research community in the field. We sought to identify factors reported to influence involvement in resident research, including perceived barriers. Anonymous data were collected via an online survey distributed to all residents enrolled in accredited Ob/Gyn residency programs throughout Canada. The 10-minute, previously piloted questionnaire covered questions related to demographic information, research experience, career goals, current research activities, opinions on research environment, and opinions regarding the effect of research on future practice. Descriptive statistics were used to describe demographics, research background, and current research activities. Categorical variables were compared using the chi-square analysis and continuous variables were compared using the Mann-Whitney rank sum tests. A total of 175 residents completed the survey; 61% agreed/strongly agreed that they participate in research solely because it is mandated by their program, 22% felt that their training environment did not promote research, 19% disagreed/strongly disagreed that research is a positive experience, while 70% agreed/strongly agreed that they would prefer to complete another educational activity other than a research project. Time constraints owing to residency duties, time constraints owing to personal reasons, and lack of statistical knowledge were reported as barriers to research involvement by 97%, 90%, and 74% of trainees, respectively. Residents with graduate degrees were less likely to report lack of training on research design as a moderate/extreme barrier (7% vs 32%, p = 0.007). There exists considerable disparity in enthusiasm for scholarly research activity among Ob/Gyn residents. Curricular development should focus on addressing resident-reported barriers, including the provision of protected time for research and access to statistical support and education, particularly for residents without graduate degrees. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Co-occurrence statistics as a language-dependent cue for speech segmentation.
Saksida, Amanda; Langus, Alan; Nespor, Marina
2017-05-01
To what extent can language acquisition be explained in terms of different associative learning mechanisms? It has been hypothesized that distributional regularities in spoken languages are strong enough to elicit statistical learning about dependencies among speech units. Distributional regularities could be a useful cue for word learning even without rich language-specific knowledge. However, it is not clear how strong and reliable the distributional cues are that humans might use to segment speech. We investigate cross-linguistic viability of different statistical learning strategies by analyzing child-directed speech corpora from nine languages and by modeling possible statistics-based speech segmentations. We show that languages vary as to which statistical segmentation strategies are most successful. The variability of the results can be partially explained by systematic differences between languages, such as rhythmical differences. The results confirm previous findings that different statistical learning strategies are successful in different languages and suggest that infants may have to primarily rely on non-statistical cues when they begin their process of speech segmentation. © 2016 John Wiley & Sons Ltd.
ERIC Educational Resources Information Center
LeMire, Steven D.
2010-01-01
This paper proposes an argument framework for the teaching of null hypothesis statistical testing and its application in support of research. Elements of the Toulmin (1958) model of argument are used to illustrate the use of p values and Type I and Type II error rates in support of claims about statistical parameters and subject matter research…
NASA Technical Reports Server (NTRS)
Dominick, Wayne D. (Editor); Bassari, Jinous; Triantafyllopoulos, Spiros
1984-01-01
The University of Southwestern Louisiana (USL) NASA PC R and D statistical analysis support package is designed to be a three-level package to allow statistical analysis for a variety of applications within the USL Data Base Management System (DBMS) contract work. The design addresses usage of the statistical facilities as a library package, as an interactive statistical analysis system, and as a batch processing package.
ERIC Educational Resources Information Center
Norris, John M.
2015-01-01
Traditions of statistical significance testing in second language (L2) quantitative research are strongly entrenched in how researchers design studies, select analyses, and interpret results. However, statistical significance tests using "p" values are commonly misinterpreted by researchers, reviewers, readers, and others, leading to…
1987-04-01
of jobs, four types of exclusionary barriers are investigated: "segregated networks" at the candidate stage, "information bias" and " statistical ...constitutional law, and socio-economic theory (for example, Glazer, 1975; Maguire, 1980). Disagreements have been particularly strong about the preferen...will present statistics on current labor market processes that can be used to assess the continuing need for strong policies of equal employment
Canadian Nurses' Perspectives on Prostate Cancer Support Groups: A Survey Study.
Yu Ko, Wellam F; Oliffe, John L; Han, Christina S; Garrett, Bernie; Henwood, Tim; Tuckett, Anthony G; Sohrevardi, Armin
2016-01-01
Prostate cancer support groups (PCSGs) are community-based organizations that offer information and psychosocial support to men who experience prostate cancer and their families. Nurses are well positioned to refer men to a range of psychosocial resources to help them adjust to prostate cancer; however, little is known about nurses' perspectives on PCSGs. The aim of this study was to describe nurses' views about PCSGs as a means to making recommendations for advancing the effectiveness of PCSGs. A convenience sample of 101 Canadian nurses completed a 43-item Likert-scale questionnaire with the additional option of providing comments in response to an open-ended question. Univariate descriptive statistics and content analysis were used to analyze the quantitative and qualitative data, respectively. Participants held positive views about the roles and potential impact of PCSGs. Participants strongly endorsed the benefits of support groups in disseminating information and providing support to help decrease patient anxiety. Online support groups were endorsed as a practical alternative for men who are reluctant to participate in face-to-face groups. Findings suggest that nurses support the value of Canadian face-to-face and online PCSGs. This is important, given that nurses can help connect individual patients to community-based sources providing psychosocial support. Many men benefit from participating in PCSGs. Aside from positively endorsing the work of PCSGs, nurses are important partners for raising awareness of these groups among potential attendees and can directly contribute to information sharing in face-to-face and online PCSGs.
Asymptotically Optimal and Private Statistical Estimation
NASA Astrophysics Data System (ADS)
Smith, Adam
Differential privacy is a definition of "privacy" for statistical databases. The definition is simple, yet it implies strong semantics even in the presence of an adversary with arbitrary auxiliary information about the database.
Neville, Kathleen; DiBona, Courtney; Mahler, Maureen
2016-01-01
Hourly rounds have re-emerged as standard practice among nurses in acute care settings, and there is the need to identify nurses' perceptions regarding this practice. Further use of the Nurses' Perception of Patient Rounding Scale (NPPRS) is needed to further validate this new instrument. In addition, there exists a dearth of literature that examines the impact of hours worked and shift on nurses' perceptions of patient rounding. The purpose of this descriptive study was to explore nurses' perception of the required practice of patient rounding, to examine the influence of nurses' shift on nurses' perception of rounding practice, and to provide additional psychometric support for the NPPRS. The NPPRS, a 42-item scale in 5-point Likert format, and a demographic information sheet were used in the study. The NPPRS yields three subscales: communication, patient benefits, and nurse benefits. Using a convenience sample of anonymous nurse participants, 76 nurses from five medical-surgical units at a medical center in the northeast corridor of the United States participated in the study. Further psychometric support for the NPPRS was demonstrated. Excellent reliability coefficients via Cronbach's alpha for the total scale (0.91) and each of the subscales were obtained. A statistically significant difference was noted among nurses working 8 hours versus 12 hours or combined 8- and 12-hour workloads. Perceptions of nurse benefits were statistically significantly higher for nurses working 8 hours. In addition, results indicated that nurses perceived rounding to be more beneficial to their own practice than to patients. Analyses revealed that leadership support was instrumental in successful rounding practice. Further support for the NPPRS was obtained through this study. Strong nursing leadership, supportive of rounding, is essential for successful rounding. Further research should examine the efficacy of nurse rounding-developed protocols specific to the shift and unit of nursing practice.
Zhao, Siqi; Qu, Lijun; Liu, He; Gao, Lijun; Jiao, Mingli; Liu, Jinghua; Liang, Libo; Zhao, Yanming; Wu, Qunhong
2016-01-01
The study's objectives were to: 1) use social support theory to examine factors influencing healthcare workers' opinions about workplace violence (WPV) prevention strategies, and 2) to determine the types of support that general practitioners (GPs) and general nurses sought and expected to use after WPV exposure. A cross-sectional survey was used to assess a sample of 448 GPs and 412 general nurses from 90 township hospitals located in Heilongjiang province, China. Results revealed that workers exposed to physical, psychological or both WPV types had a strong opinion about the necessity of improving diagnosis/treatment competence, developing violence prevention guidelines and plans, using protective equipment, and reinforcing staff by providing back-up support. The last two strategies were also selected by tertiary hospital workers in our previous study. In addition, workers with high anxiety selected the following prevention strategies as most effective: improving doctor-patient communication skills; installing cameras on wards; keeping work areas bright; improvements in violence reporting, statistics, and interventions; security patrols in the key departments; reinforcing staff; and correcting inaccurate media perspectives and reports. The last four strategies were also selected by tertiary hospital workers. All respondents expected to receive organisational and social support. In conclusion, these prevention strategies should be tailored to the different requirements of specific populations. Furthermore, it is necessary for organisations, the public, and policymakers to provide powerful support in WPV prevention.
Sick of inequality: gender and support for paid sick days.
Lindemann, Danielle J; Houser, Linda; White, Karen
2015-01-01
The availability of paid sick days (PSD) is on the forefront of policy issues relating to women's health and well-being. Previous research regarding PSD and other forms of family-work balance legislation has linked access to paid time off from work for addressing one's own or another's health concerns to a range of health benefits for working women and their families. In general, public support for such policies is high, but little work has tested the extent to which support extends to PSD. Researchers have yet to engage in a rigorous statistical analysis of public opinion on PSD, including whether opinion varies by gender. Using data from a 2013 poll of adults in New Jersey (n = 925), we bridged this research gap by conducting the first multivariate analysis of public attitudes toward PSD. As expected, we found markedly high levels of support for PSD across all respondents, with a preponderance of most sociodemographic categories supporting proposed PSD legislation in New Jersey. We also found that gender was a strong predictor of support for PSD, with women significantly (odds ratio, 1.916; p ≤ .01) more likely than men to be in favor of such legislation. We discuss the implications of our findings for future work on PSD as well as for research concerning women, wellness, and work-life legislation more broadly. Published by Elsevier Inc.
Kail, Robert V
2013-11-01
According to dual-process models that include analytic and heuristic modes of processing, analytic processing is often expected to become more common with development. Consistent with this view, on reasoning problems, adolescents are more likely than children to select alternatives that are backed by statistical evidence. It is shown here that this pattern depends on the quality of the statistical evidence and the quality of the testimonial that is the typical alternative to statistical evidence. In Experiment 1, 9- and 13-year-olds (N=64) were presented with scenarios in which solid statistical evidence was contrasted with casual or expert testimonial evidence. When testimony was casual, children relied on it but adolescents did not; when testimony was expert, both children and adolescents relied on it. In Experiment 2, 9- and 13-year-olds (N=83) were presented with scenarios in which casual testimonial evidence was contrasted with weak or strong statistical evidence. When statistical evidence was weak, children and adolescents relied on both testimonial and statistical evidence; when statistical evidence was strong, most children and adolescents relied on it. Results are discussed in terms of their implications for dual-process accounts of cognitive development. Copyright © 2013 Elsevier Inc. All rights reserved.
SOCR Analyses - an Instructional Java Web-based Statistical Analysis Toolkit.
Chu, Annie; Cui, Jenny; Dinov, Ivo D
2009-03-01
The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test.The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website.In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models.
Landstrom, Bjorn; Mattsson, Bengt; Nordin, Per; Rudebeck, Carl E
2014-03-15
The aim of the study was to investigate medical students' views on general practice based on their experiences in training, and to find out whether there were certain views associated with the intention to become a GP. A questionnaire, based on our earlier studies about GP working behaviour, was handed out to medical students in terms 1, 3, 5, 7, 10 and 11 of undergraduate studies in Gothenburg, Sweden. The analysis comprised statistical descriptions and comparisons. The students regarded general practice positively. They found the work environment good, the GP's awareness of patients' living conditions necessary, and that GP work requires medical breadth. The status of the GP in the medical profession was not considered high. One-fourth of the students strongly agreed with the possibility of a future as a GP. This attitude was statistically associated with support to the statements that general practice offers a good work environment and should be a major component in undergraduate training. Students with a negative attitude to working as GPs were also negative to having a major component of general practice in undergraduate training. Medical students with a positive stated attitude towards becoming GPs support changes in undergraduate training to include more general practice. The risk of increasing a negative attitude should be considered when changes are discussed.
Everroad, R Craig; Wood, A Michelle
2012-09-01
In marine Synechococcus there is evidence for the adaptive evolution of spectrally distinct forms of the major light harvesting pigment phycoerythrin (PE). Recent research has suggested that these spectral forms of PE have a different evolutionary history than the core genome. However, a lack of explicit statistical testing of alternative hypotheses or for selection on these genes has made it difficult to evaluate the evolutionary relationships between spectral forms of PE or the role horizontal gene transfer (HGT) may have had in the adaptive phenotypic evolution of the pigment system in marine Synechococcus. In this work, PE phylogenies of picocyanobacteria with known spectral phenotypes, including newly co-isolated strains of marine Synechococcus from the Gulf of Mexico, were constructed to explore the diversification of spectral phenotype and PE evolution in this group more completely. For the first time, statistical evaluation of competing evolutionary hypotheses and tests for positive selection on the PE locus in picocyanobacteria were performed. Genes for PEs associated with specific PE spectral phenotypes formed strongly supported monophyletic clades within the PE tree with positive directional selection driving evolution towards higher phycourobilin (PUB) content. The presence of the PUB-lacking phenotype in PE-containing marine picocyanobacteria from cyanobacterial lineages identified as Cyanobium is best explained by HGT into this group from marine Synechococcus. Taken together, these data provide strong examples of adaptive evolution of a single phenotypic trait in bacteria via mutation, positive directional selection and horizontal gene transfer. Copyright © 2012 Elsevier Inc. All rights reserved.
Lankshear, Sara; Srigley, John; McGowan, Thomas; Yurcan, Marta; Sawka, Carol
2013-11-01
Cancer Care Ontario implemented synoptic pathology reporting across Ontario, impacting the practice of pathologists, surgeons, and medical and radiation oncologists. The benefits of standardized synoptic pathology reporting include enhanced completeness and improved consistency in comparison with narrative reports, with reported challenges including increased workload and report turnaround time. To determine the impact of synoptic pathology reporting on physician satisfaction specific to practice and process. A descriptive, cross-sectional design was utilized involving 970 clinicians across 27 hospitals. An 11-item survey was developed to obtain information regarding timeliness, completeness, clarity, and usability. Open-ended questions were also employed to obtain qualitative comments. A 51% response rate was obtained, with descriptive statistics reporting that physicians perceive synoptic reports as significantly better than narrative reports. Correlation analysis revealed a moderately strong, positive relationship between respondents' perceptions of overall satisfaction with the level of information provided and perceptions of completeness for clinical decision making (r = 0.750, P < .001) and ease of finding information for clinical decision making (r = 0.663, P < .001). Dependent t tests showed a statistically significant difference in the satisfaction scores of pathologists and oncologists (t169 = 3.044, P = .003). Qualitative comments revealed technology-related issues as the most frequently cited factor impacting timeliness of report completion. This study provides evidence of strong physician satisfaction with synoptic cancer pathology reporting as a clinical decision support tool in the diagnosis, prognosis, and treatment of cancer patients.
Xiao, Hanqiong; Li, Wei; Ma, Ruixia; Gong, Zhengpeng; Shi, Haibo; Li, Huawei; Chen, Bing; Jiang, Ye; Dai, Chunfu
2015-06-01
To describe tne regional different factors which impact on early cochlear implantation in prelingual deaf children between eastern and western regions of China. The charts of 113 children who received the cochlear implantation after 24 months old were reviewed and analyzed. Forty-five of them came from the eastern region (Jiangsu, Zhejiang or Shanghai) while 68 of them came from the western region (Ningxia or Guizhou). Parental interviews were conducted to collect information regarding the factors that impact on early cochlear implantation. Result:Based on the univariate logistic regression analysis, the odds ratio (OR) value of universal newborn hearing screening (UNHS) was 5. 481, which indicated the correlation of UNHS with early cochlear implantation is significant. There was statistical difference between the 2 groups (P<0. 01). For the financial burden, the OR value was 3. 521(strong correlation) and there was statistical difference between the 2 groups (P<0. 01). For the communication barriers and community location, the OR value was 0. 566 and 1. 128 respectively, and there was no statistical difference between the 2 groups (P>0. 05). The multivariate analysis indicated that the UNHS and financial burden are statistically different between the eastern and western regions (P=0. 00 and 0. 040 respectively). The UNHS and financial burden are statistically different between the eastern reinforced in the western region. In addition, the government and society should provide powerful policy and more financial support in the western region of China. The innovation of management system is also helpful to the early cochlear implantation.
Li, Huanjie; Nickerson, Lisa D; Nichols, Thomas E; Gao, Jia-Hong
2017-03-01
Two powerful methods for statistical inference on MRI brain images have been proposed recently, a non-stationary voxelation-corrected cluster-size test (CST) based on random field theory and threshold-free cluster enhancement (TFCE) based on calculating the level of local support for a cluster, then using permutation testing for inference. Unlike other statistical approaches, these two methods do not rest on the assumptions of a uniform and high degree of spatial smoothness of the statistic image. Thus, they are strongly recommended for group-level fMRI analysis compared to other statistical methods. In this work, the non-stationary voxelation-corrected CST and TFCE methods for group-level analysis were evaluated for both stationary and non-stationary images under varying smoothness levels, degrees of freedom and signal to noise ratios. Our results suggest that, both methods provide adequate control for the number of voxel-wise statistical tests being performed during inference on fMRI data and they are both superior to current CSTs implemented in popular MRI data analysis software packages. However, TFCE is more sensitive and stable for group-level analysis of VBM data. Thus, the voxelation-corrected CST approach may confer some advantages by being computationally less demanding for fMRI data analysis than TFCE with permutation testing and by also being applicable for single-subject fMRI analyses, while the TFCE approach is advantageous for VBM data. Hum Brain Mapp 38:1269-1280, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
A Growth-rate Indicator for Compton-thick Active Galactic Nuclei
NASA Astrophysics Data System (ADS)
Brightman, M.; Masini, A.; Ballantyne, D. R.; Baloković, M.; Brandt, W. N.; Chen, C.-T.; Comastri, A.; Farrah, D.; Gandhi, P.; Harrison, F. A.; Ricci, C.; Stern, D.; Walton, D. J.
2016-07-01
Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGNs) is difficult to measure. A statistically significant correlation between the Eddington ratio, λ Edd, and the X-ray power-law index, Γ, observed in unobscured AGNs offers an estimate of their growth rate from X-ray spectroscopy (albeit with large scatter). However, since X-rays undergo reprocessing by Compton scattering and photoelectric absorption when the line of sight to the central engine is heavily obscured, the recovery of the intrinsic Γ is challenging. Here we study a sample of local, predominantly CT megamaser AGNs, where the black hole mass, and thus Eddington luminosity, are well known. We compile results of the X-ray spectral fitting of these sources with sensitive high-energy (E > 10 keV) NuSTAR data, where X-ray torus models, which take into account the reprocessing effects have been used to recover the intrinsic Γ values and X-ray luminosities, L X. With a simple bolometric correction to L X to calculate λ Edd, we find a statistically significant correlation between Γ and λ Edd (p = 0.007). A linear fit to the data yields Γ = (0.41 ± 0.18)log10 λ Edd + (2.38 ± 0.20), which is statistically consistent with results for unobscured AGNs. This result implies that torus modeling successfully recovers the intrinsic AGN parameters. Since the megamasers have low-mass black holes (M BH ≈ 106-107 M ⊙) and are highly inclined, our results extend the Γ-λ Edd relationship to lower masses and argue against strong orientation effects in the corona, in support of AGN unification. Finally this result supports the use of Γ as a growth-rate indicator for accreting black holes, even for CT AGNs.
Statistical analyses support power law distributions found in neuronal avalanches.
Klaus, Andreas; Yu, Shan; Plenz, Dietmar
2011-01-01
The size distribution of neuronal avalanches in cortical networks has been reported to follow a power law distribution with exponent close to -1.5, which is a reflection of long-range spatial correlations in spontaneous neuronal activity. However, identifying power law scaling in empirical data can be difficult and sometimes controversial. In the present study, we tested the power law hypothesis for neuronal avalanches by using more stringent statistical analyses. In particular, we performed the following steps: (i) analysis of finite-size scaling to identify scale-free dynamics in neuronal avalanches, (ii) model parameter estimation to determine the specific exponent of the power law, and (iii) comparison of the power law to alternative model distributions. Consistent with critical state dynamics, avalanche size distributions exhibited robust scaling behavior in which the maximum avalanche size was limited only by the spatial extent of sampling ("finite size" effect). This scale-free dynamics suggests the power law as a model for the distribution of avalanche sizes. Using both the Kolmogorov-Smirnov statistic and a maximum likelihood approach, we found the slope to be close to -1.5, which is in line with previous reports. Finally, the power law model for neuronal avalanches was compared to the exponential and to various heavy-tail distributions based on the Kolmogorov-Smirnov distance and by using a log-likelihood ratio test. Both the power law distribution without and with exponential cut-off provided significantly better fits to the cluster size distributions in neuronal avalanches than the exponential, the lognormal and the gamma distribution. In summary, our findings strongly support the power law scaling in neuronal avalanches, providing further evidence for critical state dynamics in superficial layers of cortex.
Investigation and classification of spume droplets production mechanisms at hurricane winds
NASA Astrophysics Data System (ADS)
Troitskaya, Yuliya; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil; Zilitinkevich, Sergey
2016-04-01
Sea sprays are typical element of the marine atmospheric boundary layer of important environmental effect. There are still significant uncertainties in estimations of these effects due to insufficient knowledge on the sea spray generation function. The reason for that are difficulties of direct measurements and insufficient knowledge about the mechanisms of the spume droplet's formation. This study is concerned with the laboratory experiments for identification of mechanisms due to which a strong wind tears off water from the crest of the waves made at the high-speed wind-wave flume of IAP RAS. In order to obtain statistical data for the events on the surface, leading to the spray generation a high-speed video-filming was made using a horizontal and vertical shadow methods at rates of up to 10,000 fps in a wide range of wind speeds (20 - 35 m/s). Classification of phenomena responsible for generation of spume droplets was made. It was observed for the friction velocities from 0.8 to 1.5 m/s that the generation of the spume droplets is caused by 3 types of local phenomena: breaking of "projections" see e.g.[1], bursting of submerged bubbles [2,3] and bag breakup - it begins with increase of small-scale elevation of the surface, transforming to small "sails" then inflated to a water film bordered by a thicker rim and at last blows up, so the droplets are produced from rupture of the water film and fragmentation of the rim (the first report on the observation of a new mechanism of spume droplets', similar to bag-breakup regime was made in [4]). Statistical analysis of number of these phenomena at different winds showed that the "bag-breakup" is the major mechanism of spume droplets generation at strong and hurricane winds. Statistical distributions of observed "bags" geometrical parameters at different airflow velocities were retrieved from video-filming using specially developed software which allowed semi-automatic registering of image features. Acknowledgements: The work was supported by RFBR (Project No. 16-05-00839, 15-35-20953, 14-05-91767), Yu. Troitskaya, D. Sergeev, A. Kandaurov were partially supported by FP7 collaborative project No. 612610, experimental studies of spray generation mechanisms were supported by Russian Science Foundation (Grant No. 15-17-20009), post-processing was supported by Russian Science Foundation (Grant No. 14-17-00667). References: 1. Koga M. Direct production of droplets from breaking wind-waves - its observation by a multi-colored overlapping exposure photographing technique // Tellus. 1981. V.33. Issue 6. P. 552-563 2. Blanchard, D.C., The electrification of the atmosphere by particles from bubbles in the sea, Progr. Oceanogr., 1963. V. 1. P. 71-202. 3. Spiel D.E. On the birth of jet drops from bubbles bursting on water surfaces // J. Geophys. Res. 1995. V.100. P. 4995-5006 4. Villermaux, E. Fragmentation // Annu. Rev. Fluid Mech., 2007. V.39. P.419-446
Unlawful Discrimination DEOCS 4.1 Construct Validity Summary
2017-08-01
Included is a review of the 4.0 description and items, followed by the proposed modifications to the factor. The current DEOCS (4.0) contains multiple...Officer (E7 – E9) 586 10.8% Junior Officer (O1 – O3) 474 9% Senior Officer (O4 and above) 391 6.1% Descriptive Statistics and Reliability This section...displays descriptive statistics for the items on the Unlawful Discrimination scale. All items had a range from 1 to 7 (strongly disagree to strongly
Spatio-temporal analysis of aftershock sequences in terms of Non Extensive Statistical Physics.
NASA Astrophysics Data System (ADS)
Chochlaki, Kalliopi; Vallianatos, Filippos
2017-04-01
Earth's seismicity is considered as an extremely complicated process where long-range interactions and fracturing exist (Vallianatos et al., 2016). For this reason, in order to analyze it, we use an innovative methodological approach, introduced by Tsallis (Tsallis, 1988; 2009), named Non Extensive Statistical Physics. This approach introduce a generalization of the Boltzmann-Gibbs statistical mechanics and it is based on the definition of Tsallis entropy Sq, which maximized leads the the so-called q-exponential function that expresses the probability distribution function that maximizes the Sq. In the present work, we utilize the concept of Non Extensive Statistical Physics in order to analyze the spatiotemporal properties of several aftershock series. Marekova (Marekova, 2014) suggested that the probability densities of the inter-event distances between successive aftershocks follow a beta distribution. Using the same data set we analyze the inter-event distance distribution of several aftershocks sequences in different geographic regions by calculating non extensive parameters that determine the behavior of the system and by fitting the q-exponential function, which expresses the degree of non-extentivity of the investigated system. Furthermore, the inter-event times distribution of the aftershocks as well as the frequency-magnitude distribution has been analyzed. The results supports the applicability of Non Extensive Statistical Physics ideas in aftershock sequences where a strong correlation exists along with memory effects. References C. Tsallis, Possible generalization of Boltzmann-Gibbs statistics, J. Stat. Phys. 52 (1988) 479-487. doi:10.1007/BF01016429 C. Tsallis, Introduction to nonextensive statistical mechanics: Approaching a complex world, 2009. doi:10.1007/978-0-387-85359-8. E. Marekova, Analysis of the spatial distribution between successive earthquakes in aftershocks series, Annals of Geophysics, 57, 5, doi:10.4401/ag-6556, 2014 F. Vallianatos, G. Papadakis, G. Michas, Generalized statistical mechanics approaches to earthquakes and tectonics. Proc. R. Soc. A, 472, 20160497, 2016.
Moral foundations in an interacting neural networks society: A statistical mechanics analysis
NASA Astrophysics Data System (ADS)
Vicente, R.; Susemihl, A.; Jericó, J. P.; Caticha, N.
2014-04-01
The moral foundations theory supports that people, across cultures, tend to consider a small number of dimensions when classifying issues on a moral basis. The data also show that the statistics of weights attributed to each moral dimension is related to self-declared political affiliation, which in turn has been connected to cognitive learning styles by the recent literature in neuroscience and psychology. Inspired by these data, we propose a simple statistical mechanics model with interacting neural networks classifying vectors and learning from members of their social neighbourhood about their average opinion on a large set of issues. The purpose of learning is to reduce dissension among agents when disagreeing. We consider a family of learning algorithms parametrized by δ, that represents the importance given to corroborating (same sign) opinions. We define an order parameter that quantifies the diversity of opinions in a group with homogeneous learning style. Using Monte Carlo simulations and a mean field approximation we find the relation between the order parameter and the learning parameter δ at a temperature we associate with the importance of social influence in a given group. In concordance with data, groups that rely more strongly on corroborating evidence sustain less opinion diversity. We discuss predictions of the model and propose possible experimental tests.
Statistical benchmarking for orthogonal electrostatic quantum dot qubit devices
NASA Astrophysics Data System (ADS)
Gamble, John; Frees, Adam; Friesen, Mark; Coppersmith, S. N.
2014-03-01
Quantum dots in semiconductor systems have emerged as attractive candidates for the implementation of quantum information processors because of the promise of scalability, manipulability, and integration with existing classical electronics. A limitation in current devices is that the electrostatic gates used for qubit manipulation exhibit strong cross-capacitance, presenting a barrier for practical scale-up. Here, we introduce a statistical framework for making precise the notion of orthogonality. We apply our method to analyze recently implemented designs at the University of Wisconsin-Madison that exhibit much increased orthogonal control than was previously possible. We then use our statistical modeling to future device designs, providing practical guidelines for devices to have robust control properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy Nuclear Security Administration under contract DE-AC04-94AL85000. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressly or implied, of the US Government. This work was supported in part by the Laboratory Directed Research and Development program at Sandia National Laboratories, by ARO (W911NF-12-0607), and by the United States Department of Defense.
Singh, Kunwar P; Gupta, Shikha; Ojha, Priyanka; Rai, Premanjali
2013-04-01
The research aims to develop artificial intelligence (AI)-based model to predict the adsorptive removal of 2-chlorophenol (CP) in aqueous solution by coconut shell carbon (CSC) using four operational variables (pH of solution, adsorbate concentration, temperature, and contact time), and to investigate their effects on the adsorption process. Accordingly, based on a factorial design, 640 batch experiments were conducted. Nonlinearities in experimental data were checked using Brock-Dechert-Scheimkman (BDS) statistics. Five nonlinear models were constructed to predict the adsorptive removal of CP in aqueous solution by CSC using four variables as input. Performances of the constructed models were evaluated and compared using statistical criteria. BDS statistics revealed strong nonlinearity in experimental data. Performance of all the models constructed here was satisfactory. Radial basis function network (RBFN) and multilayer perceptron network (MLPN) models performed better than generalized regression neural network, support vector machines, and gene expression programming models. Sensitivity analysis revealed that the contact time had highest effect on adsorption followed by the solution pH, temperature, and CP concentration. The study concluded that all the models constructed here were capable of capturing the nonlinearity in data. A better generalization and predictive performance of RBFN and MLPN models suggested that these can be used to predict the adsorption of CP in aqueous solution using CSC.
NASA Astrophysics Data System (ADS)
Kim, Ji-Soo; Han, Soo-Hyung; Ryang, Woo-Hun
2001-12-01
Electrical resistivity mapping was conducted to delineate boundaries and architecture of the Eumsung Basin Cretaceous. Basin boundaries are effectively clarified in electrical dipole-dipole resistivity sections as high-resistivity contrast bands. High resistivities most likely originate from the basement of Jurassic granite and Precambrian gneiss, contrasting with the lower resistivities from infilled sedimentary rocks. The electrical properties of basin-margin boundaries are compatible with the results of vertical electrical soundings and very-low-frequency electromagnetic surveys. A statistical analysis of the resistivity sections is tested in terms of standard deviation and is found to be an effective scheme for the subsurface reconstruction of basin architecture as well as the surface demarcation of basin-margin faults and brittle fracture zones, characterized by much higher standard deviation. Pseudo three-dimensional architecture of the basin is delineated by integrating the composite resistivity structure information from two cross-basin E-W magnetotelluric lines and dipole-dipole resistivity lines. Based on statistical analysis, the maximum depth of the basin varies from about 1 km in the northern part to 3 km or more in the middle part. This strong variation supports the view that the basin experienced pull-apart opening with rapid subsidence of the central blocks and asymmetric cross-basinal extension.
Lakatos, Eszter; Salehi-Reyhani, Ali; Barclay, Michael; Stumpf, Michael P H; Klug, David R
2017-01-01
We determine p53 protein abundances and cell to cell variation in two human cancer cell lines with single cell resolution, and show that the fractional width of the distributions is the same in both cases despite a large difference in average protein copy number. We developed a computational framework to identify dominant mechanisms controlling the variation of protein abundance in a simple model of gene expression from the summary statistics of single cell steady state protein expression distributions. Our results, based on single cell data analysed in a Bayesian framework, lends strong support to a model in which variation in the basal p53 protein abundance may be best explained by variations in the rate of p53 protein degradation. This is supported by measurements of the relative average levels of mRNA which are very similar despite large variation in the level of protein.
Support for linguistic macrofamilies from weighted sequence alignment
Jäger, Gerhard
2015-01-01
Computational phylogenetics is in the process of revolutionizing historical linguistics. Recent applications have shed new light on controversial issues, such as the location and time depth of language families and the dynamics of their spread. So far, these approaches have been limited to single-language families because they rely on a large body of expert cognacy judgments or grammatical classifications, which is currently unavailable for most language families. The present study pursues a different approach. Starting from raw phonetic transcription of core vocabulary items from very diverse languages, it applies weighted string alignment to track both phonetic and lexical change. Applied to a collection of ∼1,000 Eurasian languages and dialects, this method, combined with phylogenetic inference, leads to a classification in excellent agreement with established findings of historical linguistics. Furthermore, it provides strong statistical support for several putative macrofamilies contested in current historical linguistics. In particular, there is a solid signal for the Nostratic/Eurasiatic macrofamily. PMID:26403857
The Infeasibility of Quantifying the Reliability of Life-Critical Real-Time Software
NASA Technical Reports Server (NTRS)
Butler, Ricky W.; Finelli, George B.
1991-01-01
This paper affirms that the quantification of life-critical software reliability is infeasible using statistical methods whether applied to standard software or fault-tolerant software. The classical methods of estimating reliability are shown to lead to exhorbitant amounts of testing when applied to life-critical software. Reliability growth models are examined and also shown to be incapable of overcoming the need for excessive amounts of testing. The key assumption of software fault tolerance separately programmed versions fail independently is shown to be problematic. This assumption cannot be justified by experimentation in the ultrareliability region and subjective arguments in its favor are not sufficiently strong to justify it as an axiom. Also, the implications of the recent multiversion software experiments support this affirmation.
ERIC Educational Resources Information Center
National Science Foundation, Arlington, VA.
This document presents statistical data of direct federal science and engineering support to higher education institutions in the United States. Data presented in the report are collected annually and exclude financial support of an indirect nature. There are six categories of support presented: (1) "Research and Development"; (2) "Research and…
Jacobitz, Frank G; Schneider, Kai; Bos, Wouter J T; Farge, Marie
2016-01-01
The acceleration statistics of sheared and rotating homogeneous turbulence are studied using direct numerical simulation results. The statistical properties of Lagrangian and Eulerian accelerations are considered together with the influence of the rotation to shear ratio, as well as the scale dependence of their statistics. The probability density functions (pdfs) of both Lagrangian and Eulerian accelerations show a strong and similar dependence on the rotation to shear ratio. The variance and flatness of both accelerations are analyzed and the extreme values of the Eulerian acceleration are observed to be above those of the Lagrangian acceleration. For strong rotation it is observed that flatness yields values close to three, corresponding to Gaussian-like behavior, and for moderate and vanishing rotation the flatness increases. Furthermore, the Lagrangian and Eulerian accelerations are shown to be strongly correlated for strong rotation due to a reduced nonlinear term in this case. A wavelet-based scale-dependent analysis shows that the flatness of both Eulerian and Lagrangian accelerations increases as scale decreases, which provides evidence for intermittent behavior. For strong rotation the Eulerian acceleration is even more intermittent than the Lagrangian acceleration, while the opposite result is obtained for moderate rotation. Moreover, the dynamics of a passive scalar with gradient production in the direction of the mean velocity gradient is analyzed and the influence of the rotation to shear ratio is studied. Concerning the concentration of a passive scalar spread by the flow, the pdf of its Eulerian time rate of change presents higher extreme values than those of its Lagrangian time rate of change. This suggests that the Eulerian time rate of change of scalar concentration is mainly due to advection, while its Lagrangian counterpart is only due to gradient production and viscous dissipation.
Evaluating a linearized Euler equations model for strong turbulence effects on sound propagation.
Ehrhardt, Loïc; Cheinet, Sylvain; Juvé, Daniel; Blanc-Benon, Philippe
2013-04-01
Sound propagation outdoors is strongly affected by atmospheric turbulence. Under strongly perturbed conditions or long propagation paths, the sound fluctuations reach their asymptotic behavior, e.g., the intensity variance progressively saturates. The present study evaluates the ability of a numerical propagation model based on the finite-difference time-domain solving of the linearized Euler equations in quantitatively reproducing the wave statistics under strong and saturated intensity fluctuations. It is the continuation of a previous study where weak intensity fluctuations were considered. The numerical propagation model is presented and tested with two-dimensional harmonic sound propagation over long paths and strong atmospheric perturbations. The results are compared to quantitative theoretical or numerical predictions available on the wave statistics, including the log-amplitude variance and the probability density functions of the complex acoustic pressure. The match is excellent for the evaluated source frequencies and all sound fluctuations strengths. Hence, this model captures these many aspects of strong atmospheric turbulence effects on sound propagation. Finally, the model results for the intensity probability density function are compared with a standard fit by a generalized gamma function.
Can the exciton--polariton be defined by its quantum properties?
NASA Astrophysics Data System (ADS)
Fonseca-Romero, Karen; Cipagauta, Gustavo; Suárez-Forero, Daniel; Vinck-Posada, Herbert; Rey-González, Rafael; Herrera, William; Rodriguez, Boris
2013-03-01
We discuss the defining properties of a polariton in the framework of a microcavity-quantum dot system, described by a simple fully quantum model which takes into account loses and pumping. We show that even in the strong coupling regime, and provided that the emitted light exhibit subpoissonian statistics, the density operator of the system can be so mixed that quantum matter-radiation correlations are absent. We suggest the inclusion of matter-radiation entanglement as a defining property of the polariton. The weak-coupling, strong-coupling and lasing regimes, usually identified through the photoluminescence of the emitted light, can be understood in terms of quantum properties of the system state (entanglement, mixedness and light correlation functions). Our numerical anaylisis reveals the fundamental role of detuning on the coherence properties of the emitted light and on entanglement. In this sense, there is no polariton near resonance, even in the strong coupling regime. We show that the ``best'' polariton (maximally entangled matter-light state) is found when the exciton pumping rate is equal to the photon decay rate, and the detuning is of the order of three times the value of the coupling constant. The authors acknowledge partial financial support from Dirección de Investigación - Sede Bogotá, Universidad Nacional de Colombia (DIB-UNAL) under project 12584.
NASA Astrophysics Data System (ADS)
Afeyan, Bedros; Hüller, Stefan; Montgomery, David; Moody, John; Froula, Dustin; Hammer, James; Jones, Oggie; Amendt, Peter
2014-10-01
In mid-Z and high-Z plasmas, it is possible to control crossed bean energy transfer (CBET) and subsequently occurring single or multiple beam instabilities such as Stimulated Raman Scattering (SRS) by novel means. These new techniques are inoperative when the ion acoustic waves are in their strong damping limit, such as occurs in low Z plasmas with comparable electron and ion temperatures. For mid-Z plasmas, such as Z = 10, and near the Mach 1 surface, the strong coupling regime (SCR) can be exploited for LPI mitigation. While at higher Z values, it is thermal filamentation in conjunction with nonlocal heat transport that are useful to exploit. In both these settings, the strategy is to induce laser hot spot intensity dependent, and thus spatially dependent, frequency shifts to the ion acoustic waves in the transient response of wave-wave interactions. The latter is achieved by the on-off nature of spike trains of uneven duration and delay, STUD pulses. The least taxing use of STUD pulses is to modulate the beams at the 10 ps time scale and to choose which crossing beams are overlapping in time and which are not. Work supported by a grant from the DOE NNSA-OFES joint program on HEDP
Mismeasurement and the resonance of strong confounders: uncorrelated errors.
Marshall, J R; Hastrup, J L
1996-05-15
Greenland first documented (Am J Epidemiol 1980; 112:564-9) that error in the measurement of a confounder could resonate--that it could bias estimates of other study variables, and that the bias could persist even with statistical adjustment for the confounder as measured. An important question is raised by this finding: can such bias be more than trivial within the bounds of realistic data configurations? The authors examine several situations involving dichotomous and continuous data in which a confounder and a null variable are measured with error, and they assess the extent of resultant bias in estimates of the effect of the null variable. They show that, with continuous variables, measurement error amounting to 40% of observed variance in the confounder could cause the observed impact of the null study variable to appear to alter risk by as much as 30%. Similarly, they show, with dichotomous independent variables, that 15% measurement error in the form of misclassification could lead the null study variable to appear to alter risk by as much as 50%. Such bias would result only from strong confounding. Measurement error would obscure the evidence that strong confounding is a likely problem. These results support the need for every epidemiologic inquiry to include evaluations of measurement error in each variable considered.
Hammond, Matthew D; Cimpian, Andrei
2017-05-01
Stereotypes are typically defined as beliefs about groups, but this definition is underspecified. Beliefs about groups can be generic or statistical. Generic beliefs attribute features to entire groups (e.g., men are strong), whereas statistical beliefs encode the perceived prevalence of features (e.g., how common it is for men to be strong). In the present research, we sought to determine which beliefs-generic or statistical-are more central to the cognitive structure of stereotypes. Specifically, we tested whether generic or statistical beliefs are more influential in people's social judgments, on the assumption that greater functional importance indicates greater centrality in stereotype structure. Relative to statistical beliefs, generic beliefs about social groups were significantly stronger predictors of expectations (Studies 1-3) and explanations (Study 4) for unfamiliar individuals' traits. In addition, consistent with prior evidence that generic beliefs are cognitively simpler than statistical beliefs, generic beliefs were particularly predictive of social judgments for participants with more intuitive (vs. analytic) cognitive styles and for participants higher (vs. lower) in authoritarianism, who tend to view outgroups in simplistic, all-or-none terms. The present studies suggest that generic beliefs about groups are more central than statistical beliefs to the cognitive structure of stereotypes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Comparison of direct numerical simulation databases of turbulent channel flow at Reτ = 180
NASA Astrophysics Data System (ADS)
Vreman, A. W.; Kuerten, J. G. M.
2014-01-01
Direct numerical simulation (DNS) databases are compared to assess the accuracy and reproducibility of standard and non-standard turbulence statistics of incompressible plane channel flow at Reτ = 180. Two fundamentally different DNS codes are shown to produce maximum relative deviations below 0.2% for the mean flow, below 1% for the root-mean-square velocity and pressure fluctuations, and below 2% for the three components of the turbulent dissipation. Relatively fine grids and long statistical averaging times are required. An analysis of dissipation spectra demonstrates that the enhanced resolution is necessary for an accurate representation of the smallest physical scales in the turbulent dissipation. The results are related to the physics of turbulent channel flow in several ways. First, the reproducibility supports the hitherto unproven theoretical hypothesis that the statistically stationary state of turbulent channel flow is unique. Second, the peaks of dissipation spectra provide information on length scales of the small-scale turbulence. Third, the computed means and fluctuations of the convective, pressure, and viscous terms in the momentum equation show the importance of the different forces in the momentum equation relative to each other. The Galilean transformation that leads to minimum peak fluctuation of the convective term is determined. Fourth, an analysis of higher-order statistics is performed. The skewness of the longitudinal derivative of the streamwise velocity is stronger than expected (-1.5 at y+ = 30). This skewness and also the strong near-wall intermittency of the normal velocity are related to coherent structures.
Schneider, Adam D.; Jamali, Mohsen; Carriot, Jerome; Chacron, Maurice J.
2015-01-01
Efficient processing of incoming sensory input is essential for an organism's survival. A growing body of evidence suggests that sensory systems have developed coding strategies that are constrained by the statistics of the natural environment. Consequently, it is necessary to first characterize neural responses to natural stimuli to uncover the coding strategies used by a given sensory system. Here we report for the first time the statistics of vestibular rotational and translational stimuli experienced by rhesus monkeys during natural (e.g., walking, grooming) behaviors. We find that these stimuli can reach intensities as high as 1500 deg/s and 8 G. Recordings from afferents during naturalistic rotational and linear motion further revealed strongly nonlinear responses in the form of rectification and saturation, which could not be accurately predicted by traditional linear models of vestibular processing. Accordingly, we used linear–nonlinear cascade models and found that these could accurately predict responses to naturalistic stimuli. Finally, we tested whether the statistics of natural vestibular signals constrain the neural coding strategies used by peripheral afferents. We found that both irregular otolith and semicircular canal afferents, because of their higher sensitivities, were more optimized for processing natural vestibular stimuli as compared with their regular counterparts. Our results therefore provide the first evidence supporting the hypothesis that the neural coding strategies used by the vestibular system are matched to the statistics of natural stimuli. PMID:25855169
Statscasts: Screencasts for Complementing Lectures in Statistics Classes
ERIC Educational Resources Information Center
Dunn, Peter K.; McDonald, Christine; Loch, Birgit
2015-01-01
Students who are studying introductory statistics units but are enrolled in non-statistics majors often struggle with the content, and do not stay engaged. Support structures are in place at many Australian universities to help these students. Most of these are face-to-face support centres that the students can visit during opening hours. To…
"Dear Fresher …"--How Online Questionnaires Can Improve Learning and Teaching Statistics
ERIC Educational Resources Information Center
Bebermeier, Sarah; Nussbeck, Fridtjof W.; Ontrup, Greta
2015-01-01
Lecturers teaching statistics are faced with several challenges supporting students' learning in appropriate ways. A variety of methods and tools exist to facilitate students' learning on statistics courses. The online questionnaires presented in this report are a new, slightly different computer-based tool: the central aim was to support students…
An analysis of the relationship of flight hours and naval rotary wing aviation mishaps
2017-03-01
evidence to support indicators used for sequestration, high flight hours, night flight, and overwater flight had statistically significant effects on...estimates found enough evidence to support indicators used for sequestration, high flight hours, night flight, and overwater flight had statistically ...38 C. DESCRIPTIVE STATISTICS ................................................................38 D
Breaking time reversal in a simple smooth chaotic system.
Tomsovic, Steven; Ullmo, Denis; Nagano, Tatsuro
2003-06-01
Within random matrix theory, the statistics of the eigensolutions depend fundamentally on the presence (or absence) of time reversal symmetry. Accepting the Bohigas-Giannoni-Schmit conjecture, this statement extends to quantum systems with chaotic classical analogs. For practical reasons, much of the supporting numerical studies of symmetry breaking have been done with billiards or maps, and little with simple, smooth systems. There are two main difficulties in attempting to break time reversal invariance in a continuous time system with a smooth potential. The first is avoiding false time reversal breaking. The second is locating a parameter regime in which the symmetry breaking is strong enough to transform the fluctuation properties fully to the broken symmetry case, and yet remain weak enough so as not to regularize the dynamics sufficiently that the system is no longer chaotic. We give an example of a system of two coupled quartic oscillators whose energy level statistics closely match with those of the Gaussian unitary ensemble, and which possesses only a minor proportion of regular motion in its phase space.
Gang, Weijuan; Jing, Xianghong
2017-11-12
In recent years, more and more patients of polycystic ovary syndrome (PCOS) have strong desire to be treated with acupuncture. In "Effect of acupuncture and clomiphene in Chinese women with polycystic ovary syndrome: a randomized clinical trial" published in Journal of the American Medical Association ( JAMA ) on June 27, 2017, the finding of this research does not support acupuncture for such infertility women. The questions and doubts are proposed in the paper from the regimen of acupuncture treatment, the determination of primary outcome and the explanation of the results. It is found by comparison that the trigger point treatment in the article is different from traditional acupuncture, there is doubt in live birth rate as the primary outcome, 4-month treatment is not enough for the change of live birth rate, difference without statistic significance between acupuncture and control acupuncture does not mean invalid acupuncture because the control acupuncture is not invalid, the research and statistic method are not those planned. As a result, we consider that the conclusion is unreasonable.
NASA Astrophysics Data System (ADS)
Knudsen, Steven; Golubovic, Leonardo
Prospects to build Space Elevator (SE) systems have become realistic with ultra-strong materials such as carbon nano-tubes and diamond nano-threads. At cosmic length-scales, space elevators can be modeled as polymer like floppy strings of tethered mass beads. A new venue in SE science has emerged with the introduction of the Rotating Space Elevator (RSE) concept supported by novel algorithms discussed in this presentation. An RSE is a loopy string reaching into outer space. Unlike the classical geostationary SE concepts of Tsiolkovsky, Artsutanov, and Pearson, our RSE exhibits an internal rotation. Thanks to this, objects sliding along the RSE loop spontaneously oscillate between two turning points, one of which is close to the Earth whereas the other one is in outer space. The RSE concept thus solves a major problem in SE technology which is how to supply energy to the climbers moving along space elevator strings. The investigation of the classical and statistical mechanics of a floppy string interacting with objects sliding along it required development of subtle computational algorithms described in this presentation
J Fisher, Murray
2011-08-01
There continue to be assumptions within the nursing literature that nursing is synonymous with a feminine sex role identity. A comparative cross-sectional survey consisting of the Bem Sex Role Inventory and the Australian sex role scale was used to determine sex difference in gender characteristics of Australian nurses and with male engineers. A statistically significant difference in femininity was found between all the samples (F((2,908)) = 20.24, p < 0.00001; F((2,908)) = 60.13, p < 0.00001). A statistical difference in masculinity was found between female nurses and the two male samples on the two masculine scales (F((2,908)) = 12.48, p < 0.000001; F((2,908)) = 6.94, p = 0.001). Path analysis found strong significant direct relationships between the samples and expressive orientation (t = 27.67) and self display (t = 12.42). Whilst differences in expressive characteristics were found between male and female nurses, a similar difference was found between male nurses and male engineers, supporting the notion that male nurses perceive themselves as having feminine characteristics essentially required for nursing.
Strong Support for the Millisecond Pulsar Origin of the Galactic Center GeV Excess.
Bartels, Richard; Krishnamurthy, Suraj; Weniger, Christoph
2016-02-05
Using γ-ray data from the Fermi Large Area Telescope, various groups have identified a clear excess emission in the Inner Galaxy, at energies around a few GeV. This excess resembles remarkably well a signal from dark-matter annihilation. One of the most compelling astrophysical interpretations is that the excess is caused by the combined effect of a previously undetected population of dim γ-ray sources. Because of their spectral similarity, the best candidates are millisecond pulsars. Here, we search for this hypothetical source population, using a novel approach based on wavelet decomposition of the γ-ray sky and the statistics of Gaussian random fields. Using almost seven years of Fermi-LAT data, we detect a clustering of photons as predicted for the hypothetical population of millisecond pulsar, with a statistical significance of 10.0σ. For plausible values of the luminosity function, this population explains 100% of the observed excess emission. We argue that other extragalactic or Galactic sources, a mismodeling of Galactic diffuse emission, or the thick-disk population of pulsars are unlikely to account for this observation.
Robustness of the sequential lineup advantage.
Gronlund, Scott D; Carlson, Curt A; Dailey, Sarah B; Goodsell, Charles A
2009-06-01
A growing movement in the United States and around the world involves promoting the advantages of conducting an eyewitness lineup in a sequential manner. We conducted a large study (N = 2,529) that included 24 comparisons of sequential versus simultaneous lineups. A liberal statistical criterion revealed only 2 significant sequential lineup advantages and 3 significant simultaneous advantages. Both sequential advantages occurred when the good photograph of the guilty suspect or either innocent suspect was in the fifth position in the sequential lineup; all 3 simultaneous advantages occurred when the poorer quality photograph of the guilty suspect or either innocent suspect was in the second position. Adjusting the statistical criterion to control for the multiple tests (.05/24) revealed no significant sequential advantages. Moreover, despite finding more conservative overall choosing for the sequential lineup, no support was found for the proposal that a sequential advantage was due to that conservative criterion shift. Unless lineups with particular characteristics predominate in the real world, there appears to be no strong preference for conducting lineups in either a sequential or a simultaneous manner. (PsycINFO Database Record (c) 2009 APA, all rights reserved).
An enriched multimedia eBook application to facilitate learning of anatomy.
Stirling, Allan; Birt, James
2014-01-01
This pilot study compared the use of an enriched multimedia eBook with traditional methods for teaching the gross anatomy of the heart and great vessels. Seventy-one first-year students from an Australian medical school participated in the study. Students' abilities were examined by pretest, intervention, and post-test measurements. Perceptions and attitudes toward eBook technology were examined by survey questions. Results indicated a strongly positive user experience coupled with increased marks; however, there were no statistically significant results for the eBook method of delivery alone outperforming the traditional anatomy practical session. Results did show a statistically significant difference in the final marks achieved based on the sequencing of the learning modalities. With initial interaction with the multimedia content followed by active experimentation in the anatomy lab, students' performance was improved in the final test. Obtained data support the role of eBook technology in modern anatomy curriculum being a useful adjunct to traditional methods. Further study is needed to investigate the importance of sequencing of teaching interventions. © 2013 American Association of Anatomists.
Gama, Silvana Granado Nogueira da; Szwarcwald, Célia Landmann; Sabroza, Adriane Reis; Castelo Branco, Viviane; Leal, Maria do Carmo
2004-01-01
This study characterizes the women receiving precarious prenatal care according to socio-demographic variables, mother's reproductive history, family support, satisfaction with pregnancy, and risk behavior during pregnancy. A total of 1,967 adolescents were interviewed in the immediate post-partum in public and outsourced maternity hospitals in the City of Rio de Janeiro. The dependent variable was the number of prenatal appointments (0-3; 4-6; 7 or more). The statistical analysis aimed to test the hypothesis of homogeneity of proportions, including bi- and multivariate analysis, using multinomial logistic regression, in which the reference category for the response variable was 7 or more prenatal visits. Higher (and statistically significant) proportions of insufficient number of prenatal visits (0-3) were associated with: precarious sanitation conditions; not living with the child's father; attempted abortion; and smoking, drinking, and/or drug use during pregnancy. The results strongly indicate that mothers with worse living conditions and risk behavior during pregnancy were the same who lacked access to prenatal care.
Tzelepis, Flora; Paul, Christine L; Walsh, Raoul A; McElduff, Patrick; Knight, Jenny
2011-06-22
Systematic reviews demonstrated that proactive telephone counseling increases smoking cessation rates. However, these reviews did not differentiate studies by recruitment channel, did not adequately assess methodological quality, and combined different measures of abstinence. Twenty-four randomized controlled trials published before December 31, 2008, included seven of active recruitment, 16 of passive recruitment, and one of mixed recruitment. We rated methodological quality on selection bias, study design, confounders, blinding, data collection methods, withdrawals, and dropouts, according to the Quality Assessment Tool for Quantitative Studies. We conducted random effects meta-analysis to pool the results according to abstinence type and follow-up time for studies overall and segregated by recruitment channel, and methodological quality. The level of statistical heterogeneity was quantified by I(2). All statistical tests were two-sided. Methodological quality ratings indicated two strong, 10 moderate, and 12 weak studies. Overall, compared with self-help materials or no intervention control groups, proactive telephone counseling had a statistically significantly greater effect on point prevalence abstinence (nonsmoking at follow-up or abstinent for at least 24 hours, 7 days before follow-up) at 6-9 months (relative risk [RR] = 1.26, 95% confidence interval [CI] = 1.11 to 1.43, P < .001, I(2) = 21.4%) but not at 12-15 months after recruitment. This pattern also emerged when studies were segregated by recruitment channel (active, passive) or methodological quality (strong/moderate, weak). Overall, the positive effect on prolonged/continuous abstinence (abstinent for 3 months or longer before follow-up) was also statistically significantly greater at 6-9 months (RR = 1.58, CI = 1.26 to 1.98, P < .001, I(2) = 49.1%) and 12-18 months after recruitment (RR = 1.40, CI = 1.23 to 1.60, P < .001, I(2) = 18.5%). With the exception of point prevalence abstinence in the long term, these data support previous results showing that proactive telephone counseling has a positive impact on smoking cessation. Proactive telephone counseling increased prolonged/continuous abstinence long term for both actively and passively recruited smokers.
NASA Astrophysics Data System (ADS)
Leng, Bi-Bin; Zhang, Qi-zhen; Lai, Wen-wei; Tang, Xin-Fan
2018-06-01
The central region of China boasts a long history, abundant resources, convenient transportation, advanced economy, a strong industrial and agricultural foundation and a rapid development of modern service industry, with about 10.7% of the country's total land area, 26.5% of the country's population and a GDP of about 21.4% of the country's total . As the population center, transportation hub, economic hinterland and important market, it is the second echelon of China's economic development; the central region of China plays an important role in the division of labor in China. The middle reaches of the Yangtze River water network includes four neighboring provinces- Hubei, Hunan, Anhui and Jiangxi. Although all four provinces are located in the middle of the Yangtze River Basin, there are still quite some differences. Based on the 2017 Statistical Yearbook data, this paper studies the economic supportive index of pig breeding in four provinces located in the water network area of the middle reaches of the Yangtze River in Jiangxi, Hubei, Hunan and Anhui. The evaluation results show that among the four provinces, the socio-economic conditions of Hubei Province can most support the large-scale cultivation of live pigs, and the support of Jiangxi Province is the weakest.
Computational Complexity of Bosons in Linear Networks
2017-03-01
photon statistics while strongly reducing emission probabilities: thus leading experimental teams pursuing large-scale BOSONSAMPLING have faced a hard...Potentially, this could motivate new validation protocols exploiting statistics that include this temporal degree of freedom. The impact of...photon- statistics polluted by higher-order terms, which can be mistakenly interpreted as decreased photon-indistinguishability. In fact, in many cases
Coupling strength assumption in statistical energy analysis
Lafont, T.; Totaro, N.
2017-01-01
This paper is a discussion of the hypothesis of weak coupling in statistical energy analysis (SEA). The examples of coupled oscillators and statistical ensembles of coupled plates excited by broadband random forces are discussed. In each case, a reference calculation is compared with the SEA calculation. First, it is shown that the main SEA relation, the coupling power proportionality, is always valid for two oscillators irrespective of the coupling strength. But the case of three subsystems, consisting of oscillators or ensembles of plates, indicates that the coupling power proportionality fails when the coupling is strong. Strong coupling leads to non-zero indirect coupling loss factors and, sometimes, even to a reversal of the energy flow direction from low to high vibrational temperature. PMID:28484335
ERIC Educational Resources Information Center
Conant, Darcy Lynn
2013-01-01
Stochastic understanding of probability distribution undergirds development of conceptual connections between probability and statistics and supports development of a principled understanding of statistical inference. This study investigated the impact of an instructional course intervention designed to support development of stochastic…
A semiconductor nanowire Josephson junction microwave laser
NASA Astrophysics Data System (ADS)
Cassidy, Maja; Uilhoorn, Willemijn; Kroll, James; de Jong, Damaz; van Woerkom, David; Nygard, Jesper; Krogstrup, Peter; Kouwenhoven, Leo
We present measurements of microwave lasing from a single Al/InAs/Al nanowire Josephson junction strongly coupled to a high quality factor superconducting cavity. Application of a DC bias voltage to the Josephson junction results in photon emission into the cavity when the bias voltage is equal to a multiple of the cavity frequency. At large voltage biases, the strong non-linearity of the circuit allows for efficient down conversion of high frequency microwave photons down to multiple photons at the fundamental frequency of the cavity. In this regime, the emission linewidth narrows significantly below the bare cavity linewidth to < 10 kHz and real time analysis of the emission statistics shows above threshold lasing with a power conversion efficiency > 50%. The junction-cavity coupling and laser emission can be tuned rapidly via an external gate, making it suitable to be integrated into a scalable qubit architecture as a versatile source of coherent microwave radiation. This work has been supported by the Netherlands Organisation for Scientific Research (NWO/OCW), Foundation for Fundamental Research on Matter (FOM), European Research Council (ERC), and Microsoft Corporation Station Q.
Lee, SangYun; Park, HyunJoo; Kim, Kyoohyun; Sohn, YongHak; Jang, Seongsoo; Park, YongKeun
2017-04-21
In this paper, we present the optical characterisations of diabetic red blood cells (RBCs) in a non-invasive manner employing three-dimensional (3-D) quantitative phase imaging. By measuring 3-D refractive index tomograms and 2-D time-series phase images, the morphological (volume, surface area and sphericity), biochemical (haemoglobin concentration and content) and mechanical (membrane fluctuation) parameters were quantitatively retrieved at the individual cell level. With simultaneous measurements of individual cell properties, systematic correlative analyses on retrieved RBC parameters were also performed. Our measurements show there exist no statistically significant alterations in morphological and biochemical parameters of diabetic RBCs, compared to those of healthy (non-diabetic) RBCs. In contrast, membrane deformability of diabetic RBCs is significantly lower than that of healthy, non-diabetic RBCs. Interestingly, non-diabetic RBCs exhibit strong correlations between the elevated glycated haemoglobin in RBC cytoplasm and decreased cell deformability, whereas diabetic RBCs do not show correlations. Our observations strongly support the idea that slow and irreversible glycation of haemoglobin and membrane proteins of RBCs by hyperglycaemia significantly compromises RBC deformability in diabetic patients.
Beaver, John R.; Manis, Erin E.; Loftin, Keith A.; Graham, Jennifer L.; Pollard, Amina I.; Mitchell, Richard M.
2014-01-01
A statistically significant association was found between the concentration of total microcystin, a common class of cyanotoxins, in surface waters of lakes and reservoirs in the continental U.S. with watershed land use using data from 1156 water bodies sampled between May and October 2007 as part of the USEPA National Lakes Assessment. Nearly two thirds (65.8%) of the samples with microcystin concentrations ≥1.0 μg/L (n = 126) were limited to three nutrient and water quality-based ecoregions (Corn Belt and Northern Great Plains, Mostly Glaciated Dairy Region, South Central Cultivated Great Plains) in watersheds with strong agricultural influence. canonical correlation analysis (CCA) indicated that both microcystin concentrations and cyanobacteria abundance were positively correlated with total nitrogen, dissolved organic carbon, and temperature; correlations with total phosphorus and water clarity were not as strong. This study supports a number of regional lake studies that suggest that land use practices are related to cyanobacteria abundance, and extends the potential impacts of agricultural land use in watersheds to include the production of cyanotoxins in lakes.
NASA Astrophysics Data System (ADS)
Sous, John; Chakraborty, Monodeep; Krems, Roman; Berciu, Mona
2017-04-01
We develop a method to compute the Green's function for two particles in an infinite chain and coupled to phonons by interactions that modulate their hopping as described by the Peierls/Su-Schrieffer-Heeger (SSH) model. The method is based on a variational approximation to the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy and is shown to agree with exact digaonalization calculations. We show that the properties of bipolarons arising in such models is qualitatively different from those of the well-studied Holstein bipolarons. In particular, we show that depending on the particle statistics, strongly bound bipolarons may or may not form. In the case of hard-core bosons, we demonstrate novel effects for dimers such as sharp transitions and self-trapping. In the case of soft-core particles/ spinfull fermions, we show that the mediated interactions lead to overscreeing of the bare Hubbard U repulsion resulting in the formation of strongly bound bipolarons. This work was supported by NSERC of Canada and the Stewart Blusson Quantum Matter Institute.
Boots, Denise Paquette; Heide, Kathleen M; Cochran, John K
2004-01-01
The U.S. Supreme Court recently re-examined the constitutionality of the death penalty in the context of two of three special offender populations of murderers (juveniles, mentally retarded, and mentally incompetent). The Court reaffirmed the imposition of the death penalty for juveniles 16 and 17, while reversing itself on the mentally retarded. In reaching its decision, the Court relied on society's "evolving standards of decency." Using Likert-type items, this study is the first to have prospective jurors assess support for the death penalty for these specific offender groups. The public's support for the execution of each of the groups is then compared with existing case law. Descriptive statistics and regression analyses indicate that, as expected, the levels of support for the applicability of capital punishment to the various special offender populations are much lower than that for the general adult offender. Moreover, these findings are congruent with the holdings of the Court with one notable exception: a slight majority of respondents supported executing the mentally incompetent. Reasons for the public's apparent departure from the Supreme Court holding prohibiting the execution of mentally incompetent convicted murderers are discussed. The Court's continued role in protecting marginalized populations from "cruel and unusual punishment" is explored in the context of strong public sentiment demanding justice and finality despite changes in offenders' mental capacity. Copyright 2003 John Wiley & Sons, Ltd.
Mocellin, Simone; Verdi, Daunia; Pooley, Karen A; Landi, Maria T; Egan, Kathleen M; Baird, Duncan M; Prescott, Jennifer; De Vivo, Immaculata; Nitti, Donato
2012-06-06
Several recent studies have provided evidence that polymorphisms in the telomerase reverse transcriptase (TERT) gene sequence are associated with cancer development, but a comprehensive synopsis is not available. We conducted a systematic review and meta-analysis of the available molecular epidemiology data regarding the association between TERT locus polymorphisms and predisposition to cancer. A systematic review of the English literature was conducted by searching PubMed, Embase, Cancerlit, Google Scholar, and ISI Web of Knowledge databases for studies on associations between TERT locus polymorphisms and cancer risk. Random-effects meta-analysis was performed to pool per-allele odds ratios for TERT locus polymorphisms and risk of cancer, and between-study heterogeneity and potential bias sources (eg, publication and chasing bias) were assessed. Because the TERT locus includes the cleft lip and palate transmembrane 1-like (CLPTM1L) gene, which is in linkage disequilibrium with TERT, CLPTM1L polymorphisms were also analyzed. Cumulative evidence for polymorphisms with statistically significant associations was graded as "strong," "moderate," and "weak" according to the Venice criteria. The joint population attributable risk was calculated for polymorphisms with strong evidence of association. Eighty-five studies enrolling 490 901 subjects and reporting on 494 allelic contrasts were retrieved. Data were available on 67 TERT locus polymorphisms and 24 tumor types, for a total of 221 unique combinations of polymorphisms and cancer types. Upon meta-analysis, a statistically significant association with the risk of any cancer type was found for 22 polymorphisms. Strong, moderate, and weak cumulative evidence for association with at least one tumor type was demonstrated for 11, 9, and 14 polymorphisms, respectively. For lung cancer, which was the most studied tumor type, the estimated joint population attributable risk for three polymorphisms (TERT rs2736100, intergenic rs4635969, and CLPTM1L rs402710) was 41%. Strong evidence for lack of association was identified for five polymorphisms in three tumor types. To our knowledge, this is the largest collection of data for associations between TERT locus polymorphisms and cancer risk. Our findings support the hypothesis that genetic variability in this genomic region can modulate cancer susceptibility in humans.
Taylor, Steven; McKay, Dean; Crowe, Katherine B.; Abramowitz, Jonathan S.; Conelea, Christine A.; Calamari, John E.; Sica, Claudio
2014-01-01
Contemporary models of obsessive-compulsive disorder emphasize the importance of harm avoidance (HA) and related dysfunctional beliefs as motivators of obsessive-compulsive (OC) symptoms. Recently, there has been a resurgence of interest in Janet’s (1908) concept of incompleteness (INC) as another potentially important motivator. Contemporary investigators define INC as the sense that one’s actions, intentions, or experiences have not been properly achieved. Janet defined INC more broadly to include alexithymia, depersonalization, derealization, and impaired psychological mindedness. We conducted two studies to address four issues: (a) the clinical correlates of INC; (b) whether INC and HA are distinguishable constructs; (c) whether INC predicts OC symptoms after controlling for HA; and (d) the relative merits of broad versus narrow conceptualizations of INC. Study 1 was a meta-analysis of the clinical correlates of narrowly defined INC (16 studies, N=5,940). INC was correlated with all types of OC symptoms, and was more strongly correlated with OC symptoms than with general distress. Study 2 (N=534 nonclinical participants) showed that: (a) INC and HA were strongly correlated but factor analytically distinguishable; (b) INC statistically predicted all types of OC symptoms even after controlling for HA; and (c) narrow INC was most strongly correlated with OC symptoms whereas broad INC was most strongly correlated with general distress. Although the findings are limited by being correlational in nature, they support the hypothesis that INC, especially in its narrow form, is a motivator of OC symptoms. PMID:24491200
Tressoldi, Patrizio E.
2011-01-01
Starting from the famous phrase “extraordinary claims require extraordinary evidence,” we will present the evidence supporting the concept that human visual perception may have non-local properties, in other words, that it may operate beyond the space and time constraints of sensory organs, in order to discuss which criteria can be used to define evidence as extraordinary. This evidence has been obtained from seven databases which are related to six different protocols used to test the reality and the functioning of non-local perception, analyzed using both a frequentist and a new Bayesian meta-analysis statistical procedure. According to a frequentist meta-analysis, the null hypothesis can be rejected for all six protocols even if the effect sizes range from 0.007 to 0.28. According to Bayesian meta-analysis, the Bayes factors provides strong evidence to support the alternative hypothesis (H1) over the null hypothesis (H0), but only for three out of the six protocols. We will discuss whether quantitative psychology can contribute to defining the criteria for the acceptance of new scientific ideas in order to avoid the inconclusive controversies between supporters and opponents. PMID:21713069
Shabsigh, Ridwan; Rowland, David
2007-09-01
The Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) criteria for premature ejaculation (PE) are multifactorial, and include concepts of latency, perceived control over ejaculation, and personal distress and interpersonal difficulty related to the condition. Recent publications have suggested that these criteria are not supported by empirical evidence, leading to the proposal that a PE diagnosis should be based solely on intravaginal ejaculatory latency time (IELT), while the presence of other factors (such as perceived lack of control over ejaculation) may be used to guide treatment decisions. To examine the evidence supporting the elements of the DSM-IV-TR criteria for PE. Literature searches on IELT, perceived control over ejaculation, and personal distress and interpersonal difficulty related to ejaculation. From a historical perspective, there has been a lack of large observational studies that evaluated the contributions of the DSM-IV-TR components in men with PE. However, recently performed large observational studies have generated data supporting the inclusion of perceived control over ejaculation and personal distress related to ejaculation in the definition of PE. Furthermore, emerging evidence indicates that a perceived lack of control over ejaculation is directly associated with elevated personal distress related to ejaculation and decreased satisfaction with sexual intercourse, while the effects of IELT on these parameters are indirect, and mediated by perceived control over ejaculation. A key advantage of the DSM-IV-TR approach to the diagnosis of PE is that it firmly links PE to a negative outcome for the patient, which is an element common to diagnostic criteria for other conditions, including depression, hypertension, and osteoporosis. This new evidence strongly suggests that the DSM-IV-TR criteria for PE encompass aspects of the condition that patients describe as important.
Thermodynamics constrains allometric scaling of optimal development time in insects.
Dillon, Michael E; Frazier, Melanie R
2013-01-01
Development time is a critical life-history trait that has profound effects on organism fitness and on population growth rates. For ectotherms, development time is strongly influenced by temperature and is predicted to scale with body mass to the quarter power based on 1) the ontogenetic growth model of the metabolic theory of ecology which describes a bioenergetic balance between tissue maintenance and growth given the scaling relationship between metabolism and body size, and 2) numerous studies, primarily of vertebrate endotherms, that largely support this prediction. However, few studies have investigated the allometry of development time among invertebrates, including insects. Abundant data on development of diverse insects provides an ideal opportunity to better understand the scaling of development time in this ecologically and economically important group. Insects develop more quickly at warmer temperatures until reaching a minimum development time at some optimal temperature, after which development slows. We evaluated the allometry of insect development time by compiling estimates of minimum development time and optimal developmental temperature for 361 insect species from 16 orders with body mass varying over nearly 6 orders of magnitude. Allometric scaling exponents varied with the statistical approach: standardized major axis regression supported the predicted quarter-power scaling relationship, but ordinary and phylogenetic generalized least squares did not. Regardless of the statistical approach, body size alone explained less than 28% of the variation in development time. Models that also included optimal temperature explained over 50% of the variation in development time. Warm-adapted insects developed more quickly, regardless of body size, supporting the "hotter is better" hypothesis that posits that ectotherms have a limited ability to evolutionarily compensate for the depressing effects of low temperatures on rates of biological processes. The remaining unexplained variation in development time likely reflects additional ecological and evolutionary differences among insect species.
Pini, T May; Hawley, Sarah T; Li, Yun; Katz, Steven J; Griggs, Jennifer J
2012-07-01
The extent to which medical oncologists consider non-clinical patient factors when deciding to recommend adjuvant chemotherapy is unknown. Medical oncologists who treated a population-based sample of early stage breast cancer patients reported to the Los Angeles and Detroit Surveillance, Epidemiology, and End Results registries 2005-2007 were asked how strongly they consider a patient's ability to follow instructions, level of social support, and level of work support/flexibility in decisions to recommend adjuvant chemotherapy. Responses of 4 (Quite strongly) or 5 (Very strongly) on a five-point Likert scale defined strong consideration. Associations between oncologist/practice characteristics and strong consideration of each non-clinical factor were examined. 134 oncologists (66 %) reported strong consideration of one or more factor. Ability to follow instructions was strongly considered by 120 oncologists (59 %), social support by 78 (38 %), and work support/flexibility by 73 (36 %). Larger percent of practice devoted to breast cancer was associated with lower likelihood of strongly considering ability to follow instructions [odds ratio (OR) 0.98, 95 % confidence interval (CI) 0.97-0.99; P = 0.04]. Increased years in practice was associated with lower likelihood of strongly considering social support (OR 0.96, CI 0.93-0.99; P = 0.011), while non-white race (OR 2.1, CI 1.03-4.26; P = 0.041) and tumor board access (OR 2.04, CI 1.01-4.12; P = 0.048) were associated with higher likelihood. Non-white race was associated with strongly considering work support/flexibility (OR 2.44, CI 1.21-4.92; P = 0.013). Tumor board access (OR 2, CI 1.00-4.02; P = 0.051) was borderline significant. Non-clinical patient factors play a role in medical oncologist decision-making for breast cancer adjuvant chemotherapy recommendations.
Martínez, Cristina; Méndez, Carlos; Sánchez, María; Martínez-Sánchez, José María
To assess attitudes towards the extension of outdoor smoke-free areas on university campuses. Cross-sectional study (n=384) conducted using a questionnaire administered to medical and nursing students in Barcelona in 2014. Information was obtained pertaining to support for indoor and outdoor smoking bans on university campuses, and the importance of acting as role models. Logistic regression analyses were performed to examine agreement. Most of the students agreed on the importance of health professionals and students as role models (74.9% and 64.1%, respectively) although there were statistically significant differences by smoking status and age. 90% of students reported exposure to smoke on campus. Students expressed strong support for indoor smoke-free policies (97.9%). However, only 39.3% of participants supported regulation of outdoor smoking for university campuses. Non-smokers (OR=12.315; 95% CI: 5.377-28.204) and students ≥22 years old (OR=3.001; 95% CI: 1.439-6.257) were the strongest supporters. The students supported indoor smoke-free policies for universities. However, support for extending smoke-free regulations to outdoor areas of university campuses was limited. It is necessary to educate students about tobacco control and emphasise their importance as role models before extending outdoor smoke-free legislation at university campuses. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.
Liu, He; Gao, Lijun; Jiao, Mingli; Liu, Jinghua; Liang, Libo; Zhao, Yanming; Wu, Qunhong
2016-01-01
The study’s objectives were to: 1) use social support theory to examine factors influencing healthcare workers’ opinions about workplace violence (WPV) prevention strategies, and 2) to determine the types of support that general practitioners (GPs) and general nurses sought and expected to use after WPV exposure. A cross-sectional survey was used to assess a sample of 448 GPs and 412 general nurses from 90 township hospitals located in Heilongjiang province, China. Results revealed that workers exposed to physical, psychological or both WPV types had a strong opinion about the necessity of improving diagnosis/treatment competence, developing violence prevention guidelines and plans, using protective equipment, and reinforcing staff by providing back-up support. The last two strategies were also selected by tertiary hospital workers in our previous study. In addition, workers with high anxiety selected the following prevention strategies as most effective: improving doctor-patient communication skills; installing cameras on wards; keeping work areas bright; improvements in violence reporting, statistics, and interventions; security patrols in the key departments; reinforcing staff; and correcting inaccurate media perspectives and reports. The last four strategies were also selected by tertiary hospital workers. All respondents expected to receive organisational and social support. In conclusion, these prevention strategies should be tailored to the different requirements of specific populations. Furthermore, it is necessary for organisations, the public, and policymakers to provide powerful support in WPV prevention. PMID:27326460
Diaz, Francisco J.; McDonald, Peter R.; Pinter, Abraham; Chaguturu, Rathnam
2018-01-01
Biomolecular screening research frequently searches for the chemical compounds that are most likely to make a biochemical or cell-based assay system produce a strong continuous response. Several doses are tested with each compound and it is assumed that, if there is a dose-response relationship, the relationship follows a monotonic curve, usually a version of the median-effect equation. However, the null hypothesis of no relationship cannot be statistically tested using this equation. We used a linearized version of this equation to define a measure of pharmacological effect size, and use this measure to rank the investigated compounds in order of their overall capability to produce strong responses. The null hypothesis that none of the examined doses of a particular compound produced a strong response can be tested with this approach. The proposed approach is based on a new statistical model of the important concept of response detection limit, a concept that is usually neglected in the analysis of dose-response data with continuous responses. The methodology is illustrated with data from a study searching for compounds that neutralize the infection by a human immunodeficiency virus of brain glioblastoma cells. PMID:24905187
Filippidis, Filippos T; Agaku, Israel T; Vardavas, Constantine I; Majeed, Azeem
2014-11-01
Increased taxation on tobacco products is an effective method of reducing tobacco use. This study assessed population support among respondents aged ≥15 years, from 27 European Union (EU) countries for increased taxation and other tobacco control measures during the 2009-2012 period. Nationally representative data were obtained from the 2009 (n=26,788) and 2012 (n=26,751) cross-sectional Eurobarometer surveys. Estimates were compared using chi-square statistics. The effect of the relative change in gross domestic product (GDP) on the change in support for increased taxation during 2009-2012 was calculated using the Pearson correlation coefficient and linear regression models. Between 2009 and 2012, population support for increased taxes on tobacco products declined (56.1% to 53.2%; p<0.001). However, support for other tobacco control measures increased significantly. After adjusting for baseline GDP per capita (2009), a 10% increase in GDP per capita was associated with 4.5% increase in support of tax increases. When Latvia and Lithuania were excluded from the analyses (because of their marked deviation from the general trend), there was a strong correlation between the change in GDP and support for increased taxes (ρ=0.64; p<0.001). Also, after adjusting for baseline GDP, support for higher taxes on tobacco increased by 7.0% for every 10% increase in GDP between 2009 and 2012. Population support for tax increases declined in the EU between 2009 and 2012, especially in countries with declines in GDP nonetheless, public support for other tobacco control measures remains high, thus indicating a viable environment for more comprehensive tobacco control. © 2014 the Nordic Societies of Public Health.
O'Connor, Michael; Lee, Caroline; Ellens, Harma; Bentz, Joe
2015-02-01
Current USFDA and EMA guidance for drug transporter interactions is dependent on IC50 measurements as these are utilized in determining whether a clinical interaction study is warranted. It is therefore important not only to standardize transport inhibition assay systems but also to develop uniform statistical criteria with associated probability statements for generation of robust IC50 values, which can be easily adopted across the industry. The current work provides a quantitative examination of critical factors affecting the quality of IC50 fits for P-gp inhibition through simulations of perfect data with randomly added error as commonly observed in the large data set collected by the P-gp IC50 initiative. The types of errors simulated were (1) variability in replicate measures of transport activity; (2) transformations of error-contaminated transport activity data prior to IC50 fitting (such as performed when determining an IC50 for inhibition of P-gp based on efflux ratio); and (3) the lack of well defined "no inhibition" and "complete inhibition" plateaus. The effect of the algorithm used in fitting the inhibition curve (e.g., two or three parameter fits) was also investigated. These simulations provide strong quantitative support for the recommendations provided in Bentz et al. (2013) for the determination of IC50 values for P-gp and demonstrate the adverse effect of data transformation prior to fitting. Furthermore, the simulations validate uniform statistical criteria for robust IC50 fits in general, which can be easily implemented across the industry. A calibration of the t-statistic is provided through calculation of confidence intervals associated with the t-statistic.
O'Connor, Michael; Lee, Caroline; Ellens, Harma; Bentz, Joe
2015-01-01
Current USFDA and EMA guidance for drug transporter interactions is dependent on IC50 measurements as these are utilized in determining whether a clinical interaction study is warranted. It is therefore important not only to standardize transport inhibition assay systems but also to develop uniform statistical criteria with associated probability statements for generation of robust IC50 values, which can be easily adopted across the industry. The current work provides a quantitative examination of critical factors affecting the quality of IC50 fits for P-gp inhibition through simulations of perfect data with randomly added error as commonly observed in the large data set collected by the P-gp IC50 initiative. The types of errors simulated were (1) variability in replicate measures of transport activity; (2) transformations of error-contaminated transport activity data prior to IC50 fitting (such as performed when determining an IC50 for inhibition of P-gp based on efflux ratio); and (3) the lack of well defined “no inhibition” and “complete inhibition” plateaus. The effect of the algorithm used in fitting the inhibition curve (e.g., two or three parameter fits) was also investigated. These simulations provide strong quantitative support for the recommendations provided in Bentz et al. (2013) for the determination of IC50 values for P-gp and demonstrate the adverse effect of data transformation prior to fitting. Furthermore, the simulations validate uniform statistical criteria for robust IC50 fits in general, which can be easily implemented across the industry. A calibration of the t-statistic is provided through calculation of confidence intervals associated with the t-statistic. PMID:25692007
Båth's law and its relation to the tectonic environment: A case study for earthquakes in Mexico
NASA Astrophysics Data System (ADS)
Rodríguez-Pérez, Q.; Zúñiga, F. R.
2016-09-01
We studied 66 mainshocks and their largest aftershocks in the Mexican subduction zone and in the Gulf of California with magnitudes in the range of 5.2 < Mw < 8.0 from 1932 to 2015. Three different types of earthquakes were analyzed: shallow thrust interplate, intermediate-depth inslab and transform strike-slip earthquakes (26, 19 and 21 events, respectively). We focus on observational aspects of the Båth's law. By studying the magnitude difference, energy ratios and energy partitioning of the mainshock-largest aftershock sequences, we analyze the physics of the mainshock-largest aftershock relationship (Båth's law). The partitioning of energy during a mainshock-aftershock sequence shows that about 96-97% of the energy dissipated in a sequence is associated with the mainshock and the rest is due to aftershocks. Our results for radiated seismic energy and energy-to-moment ratio are partially in agreement with worldwide studies supporting the observation of mechanism dependence of radiated seismic energy. The statistical tests indicate that the only significant difference is for shallow thrust and strike-slip events for these parameters. The statistical comparison of stress drop of shallow thrust versus that of inslab events shows a strongly significant difference with a confidence better than 99%. The comparison of stress drop of shallow thrust events with that of strike-slip events, also indicates a strongly significant difference. We see no dependence of stress drop with magnitude, which is strong evidence of earthquake self-similarity. We do not observe a systematic depth dependence of stress drop. The results also reveal differences in the earthquake rupture among the events. The magnitude difference between the mainshock and the largest aftershock for inslab events is larger than interplate and strike-slip events suggesting focal mechanism dependence of Båth's law. For the case of this parameter, only that for inslab and strike-slip events present a significant difference with 95% confidence.
ERIC Educational Resources Information Center
Hoeken, Hans; Hustinx, Lettica
2009-01-01
Under certain conditions, statistical evidence is more persuasive than anecdotal evidence in supporting a claim about the probability that a certain event will occur. In three experiments, it is shown that the type of argument is an important condition in this respect. If the evidence is part of an argument by generalization, statistical evidence…
ERIC Educational Resources Information Center
Gratz, Zandra S.; And Others
A study was conducted at a large, state-supported college in the Northeast to establish a mechanism by which a popular software package, Statistical Package for the Social Sciences (SPSS), could be used in psychology program statistics courses in such a way that no prior computer expertise would be needed on the part of the faculty or the…
2012-01-01
Background Severe obesity is a complex condition that is associated with a wide range of serious health complications and reduced health-related quality of life (HRQoL). In addition to physiological factors, activity and participation, environmental factors, and personal factors are related to an individual’s overall quality of life HRQoL. In Norway, a course based on cognitive behavioral principles is offered to people seeking medical treatment for weight management. The aim is to assist participants to achieve a healthier lifestyle and thereby improve their HRQoL. We therefore investigated changes in HRQoL in participants after they attended this learning and mastery course, and explored how well sociodemographic variables, paid work, social support, personal factors, and surgery predicted HRQoL at 12-month follow-up. Methods A single-group longitudinal study was conducted. Data were collected by self-reported questionnaires. This article reports on those who had completed the questionnaire at the 12-month (n = 69) follow-up. HRQoL was assessed with the EQ-5D. Other standardized instruments measured employment, social support, self-efficacy, and surgery. Results At the 12-month follow-up, participants scored higher on all dimensions of the EQ-5D and on the EQ-VAS. Generalized linear model showed that having paid work, and social support were statistically significant predictors of HRQoL at the 12-month follow-up. Sex, self-efficacy, and surgery were not statistically significant associated with HRQoL. Conclusions Participation in paid work, and receiving social support from persons with whom they had a close relationship were strongly related to HRQoL in obese people 12 months after participating in a learning and mastery course. Trial registration The study is registered in Clinical Trials: NCT01336725. PMID:22901031
Ibrahim, Abdulrasheed; Delia, Ibrahim Z; Edaigbini, Sunday A; Abubakar, Amina; Dahiru, Ismail L; Lawal, Zakari Y
2013-01-01
Background: The transformation of a surgical trainee into a surgeon is strongly influenced by the quality of teaching in the operating theater. This study investigates the perceptions of residents about the educational environment of the operating theater and identifies variables that may improve the operating theater education of our trainees. Materials and Methods: Residents in the department of surgery anonymously evaluated teaching in the operating room using the operating theater education environment measure. The residents evaluated 33 variables that might have an impact on their surgical skills within the operating theater. The variables were grouped into four subscales; teaching and training, learning opportunities, operating theater atmosphere and workload/supervision/support. Differences between male and female residents and junior and senior registrars were assessed using Mann-Whitney test. Statistical analysis was completed with the statistics package for the social sciences version 17. Results: A total of 33 residents were participated in this study. Twenty nine (88%) males and 4 (12%) females. 30 (90%) were junior registrars. The mean total score was 67.5%. Operating theater atmosphere subscale had the highest score of 79.2% while workload/supervision/support subscale had the least score of 48.3%. There were significant differences between male and female resident's perception of workload/supervision/support P < 0.05; however, there was no significant differences in junior registrar versus senior registrar's perception of the education environment in all the subscales P > 0.05. Conclusion: This study has shown a satisfactory teaching environment based on the existing local realities of means, resources and tools and highlighted the need for improvement in workload/supervision/support in our institution. An acceptable learning environment in the operating theatre will produce surgeons that are technically competent to bridge the gap in the enormous unmet need for surgical care in Nigeria. PMID:24497753
Crowley, Des; Collins, Claire; Delargy, Ide; Laird, Eamon; Van Hout, Marie Claire
2017-01-13
Governmental debate in Ireland on the de facto decriminalisation of cannabis and legalisation for medical use is ongoing. A cannabis-based medicinal product (Sativex®) has recently been granted market authorisation in Ireland. This unique study aimed to investigate Irish general practitioner (GP) attitudes toward decriminalisation of cannabis and assess levels of support for use of cannabis for therapeutic purposes (CTP). General practitioners in the Irish College of General Practitioner (ICGP) database were invited to complete an online survey. Anonymous data yielded descriptive statistics (frequencies, percentages) to summarise participant demographic information and agreement with attitudinal statements. Chi-square tests and multi-nominal logistic regression were included. The response rate was 15% (n = 565) which is similar to other Irish national GP attitudinal surveys. Over half of Irish GPs did not support the decriminalisation of cannabis (56.8%). In terms of gender, a significantly higher proportion of males compared with females (40.6 vs. 15%; p < 0.0001) agreed or strongly agreed with this drug policy approach. A higher percentage of GPs with advanced addiction specialist training (level 2) agreed/strongly agreed that cannabis should be decriminalised (54.1 vs. 31.5%; p = 0.021). Over 80% of both genders supported the view that cannabis use has a significant effect on patients' mental health and increases the risk of schizophrenia (77.3%). Over half of Irish GPs supported the legalisation of cannabis for medical use (58.6%). A higher percentage of those who were level 1-trained (trained in addiction treatment but not to an advanced level) agreed/strongly agreed cannabis should be legalised for medical use (p = 0.003). Over 60% agreed that cannabis can have a role in palliative care, pain management and treatment of multiple sclerosis (MS). In the regression response predicator analysis, females were 66.2% less likely to agree that cannabis should be decriminalised, 42.5% less likely to agree that cannabis should be legalised for medical use and 59.8 and 37.6% less likely to agree that cannabis has a role in palliative care and in the treatment of multiple sclerosis (respectively) than males. The majority of Irish GPs do not support the present Irish governmental drug policy of decriminalisation of cannabis but do support the legalisation of cannabis for therapeutic purposes. Male GPs and those with higher levels of addiction training are more likely to support a more liberal drug policy approach to cannabis for personal use. A clear majority of GPs expressed significant concerns regarding both the mental and physical health risks of cannabis use. Ongoing research into the health and other effects of drug policy changes on cannabis use is required.
Mueller, Amy V; Hemond, Harold F
2016-05-18
Knowledge of ionic concentrations in natural waters is essential to understand watershed processes. Inorganic nitrogen, in the form of nitrate and ammonium ions, is a key nutrient as well as a participant in redox, acid-base, and photochemical processes of natural waters, leading to spatiotemporal patterns of ion concentrations at scales as small as meters or hours. Current options for measurement in situ are costly, relying primarily on instruments adapted from laboratory methods (e.g., colorimetric, UV absorption); free-standing and inexpensive ISE sensors for NO3(-) and NH4(+) could be attractive alternatives if interferences from other constituents were overcome. Multi-sensor arrays, coupled with appropriate non-linear signal processing, offer promise in this capacity but have not yet successfully achieved signal separation for NO3(-) and NH4(+)in situ at naturally occurring levels in unprocessed water samples. A novel signal processor, underpinned by an appropriate sensor array, is proposed that overcomes previous limitations by explicitly integrating basic chemical constraints (e.g., charge balance). This work further presents a rationalized process for the development of such in situ instrumentation for NO3(-) and NH4(+), including a statistical-modeling strategy for instrument design, training/calibration, and validation. Statistical analysis reveals that historical concentrations of major ionic constituents in natural waters across New England strongly covary and are multi-modal. This informs the design of a statistically appropriate training set, suggesting that the strong covariance of constituents across environmental samples can be exploited through appropriate signal processing mechanisms to further improve estimates of minor constituents. Two artificial neural network architectures, one expanded to incorporate knowledge of basic chemical constraints, were tested to process outputs of a multi-sensor array, trained using datasets of varying degrees of statistical representativeness to natural water samples. The accuracy of ANN results improves monotonically with the statistical representativeness of the training set (error decreases by ∼5×), while the expanded neural network architecture contributes a further factor of 2-3.5 decrease in error when trained with the most representative sample set. Results using the most statistically accurate set of training samples (which retain environmentally relevant ion concentrations but avoid the potential interference of humic acids) demonstrated accurate, unbiased quantification of nitrate and ammonium at natural environmental levels (±20% down to <10 μM), as well as the major ions Na(+), K(+), Ca(2+), Mg(2+), Cl(-), and SO4(2-), in unprocessed samples. These results show promise for the development of new in situ instrumentation for the support of scientific field work.
Lagrangian acceleration statistics in a turbulent channel flow
NASA Astrophysics Data System (ADS)
Stelzenmuller, Nickolas; Polanco, Juan Ignacio; Vignal, Laure; Vinkovic, Ivana; Mordant, Nicolas
2017-05-01
Lagrangian acceleration statistics in a fully developed turbulent channel flow at Reτ=1440 are investigated, based on tracer particle tracking in experiments and direct numerical simulations. The evolution with wall distance of the Lagrangian velocity and acceleration time scales is analyzed. Dependency between acceleration components in the near-wall region is described using cross-correlations and joint probability density functions. The strong streamwise coherent vortices typical of wall-bounded turbulent flows are shown to have a significant impact on the dynamics. This results in a strong anisotropy at small scales in the near-wall region that remains present in most of the channel. Such statistical properties may be used as constraints in building advanced Lagrangian stochastic models to predict the dispersion and mixing of chemical components for combustion or environmental studies.
Dalgard, Odd Steffen; Mykletun, Arnstein; Rognerud, Marit; Johansen, Rune; Zahl, Per Henrik
2007-01-01
Background Earlier studies have shown that people with low level of education have increased rates of mental health problems. The aim of the present study is to investigate the association between level of education and psychological distress, and to explore to which extent the association is mediated by sense of mastery, and social variables like social support, negative life events, household income, employment and marital status. Methods The data for the study were obtained from the Level of Living Survey conducted by Statistics Norway in 2002. Data on psychological distress and psychosocial variables were gathered by a self-administered questionnaire, whereas socio-demographic data were based on register statistics. Psychological distress was measured by Hopkins Symptom Checklist 25 items. Results There was a significant association between low level of education and psychological distress in both genders, the association being strongest in women aged 55–67 years. Low level of education was also significantly associated with low sense of mastery, low social support, many negative life events (only in men), low household income and unemployment,. Sense of mastery emerged as a strong mediating variable between level of education and psychological distress, whereas the other variables played a minor role when adjusting for sense of mastery. Conclusion Low sense of mastery seems to account for much of the association between low educational level and psychological distress, and should be an important target in mental health promotion for groups with low level of education. PMID:17519014
NASA Astrophysics Data System (ADS)
Chen, Lei; Kou, Yingxin; Li, Zhanwu; Xu, An; Wu, Cheng
2018-01-01
We build a complex networks model of combat System-of-Systems (SoS) based on empirical data from a real war-game, this model is a combination of command & control (C2) subnetwork, sensors subnetwork, influencers subnetwork and logistical support subnetwork, each subnetwork has idiographic components and statistical characteristics. The C2 subnetwork is the core of whole combat SoS, it has a hierarchical structure with no modularity, of which robustness is strong enough to maintain normal operation after any two nodes is destroyed; the sensors subnetwork and influencers subnetwork are like sense organ and limbs of whole combat SoS, they are both flat modular networks of which degree distribution obey GEV distribution and power-law distribution respectively. The communication network is the combination of all subnetworks, it is an assortative Small-World network with core-periphery structure, the Intelligence & Communication Stations/Command Center integrated with C2 nodes in the first three level act as the hub nodes in communication network, and all the fourth-level C2 nodes, sensors, influencers and logistical support nodes have communication capability, they act as the periphery nodes in communication network, its degree distribution obeys exponential distribution in the beginning, Gaussian distribution in the middle, and power-law distribution in the end, and its path length obeys GEV distribution. The betweenness centrality distribution, closeness centrality distribution and eigenvector centrality are also been analyzed to measure the vulnerability of nodes.
Anderson, Joe; Bingham, Geoffrey P
2010-09-01
We provide a solution to a major problem in visually guided reaching. Research has shown that binocular vision plays an important role in the online visual guidance of reaching, but the visual information and strategy used to guide a reach remains unknown. We propose a new theory of visual guidance of reaching including a new information variable, tau(alpha) (relative disparity tau), and a novel control strategy that allows actors to guide their reach trajectories visually by maintaining a constant proportion between tau(alpha) and its rate of change. The dynamical model couples the information to the reaching movement to generate trajectories characteristic of human reaching. We tested the theory in two experiments in which participants reached under conditions of darkness to guide a visible point either on a sliding apparatus or on their finger to a point-light target in depth. Slider apparatus controlled for a simple mapping from visual to proprioceptive space. When reaching with their finger, participants were forced, by perturbation of visual information used for feedforward control, to use online control with only binocular disparity-based information for guidance. Statistical analyses of trajectories strongly supported the theory. Simulations of the model were compared statistically to actual reaching trajectories. The results supported the theory, showing that tau(alpha) provides a source of information for the control of visually guided reaching and that participants use this information in a proportional rate control strategy.
Does solar activity affect human happiness?
NASA Astrophysics Data System (ADS)
Kristoufek, Ladislav
2018-03-01
We investigate the direct influence of solar activity (represented by sunspot numbers) on human happiness (represented by the Twitter-based Happiness Index). We construct four models controlling for various statistical and dynamic effects of the analyzed series. The final model gives promising results. First, there is a statistically significant negative influence of solar activity on happiness which holds even after controlling for the other factors. Second, the final model, which is still rather simple, explains around 75% of variance of the Happiness Index. Third, our control variables contribute significantly as well: happiness is higher in no sunspots days, happiness is strongly persistent, there are strong intra-week cycles and happiness peaks during holidays. Our results strongly contribute to the topical literature and they provide evidence of unique utility of the online data.
Bernotaite, Lina; Malinauskiene, Vilija
2017-06-19
The objective of the study has been to assess the associations between psychological distress and exposure to workplace bullying, taking into account possible influence of adverse psychosocial job characteristics and occupational burnout in a sample of Kaunas (Lithuania) teachers. The study sample included 517 teachers from 13 secondary schools and was conducted in 2014. The participants filled in the anonymous questionnaire (response rate 71.3%). Twenty-two-item Negative Acts Questionnaire (H. Hoel and S. Einarsen) was used for measuring the exposure to workplace bullying, Goldberg 12-item General Health Questionnaire (GHQ-12) - psychological distress, Maslach Burnout Inventory (MBI) - occupational burnout, Karasek Demand-Control questionnaire - psychosocial job stressors. The IBM SPSS Statistics version 20.0 was used for performing the statistical analysis. Associations between psychological distress, exposure to workplace bullying, psychosocial job characteristics and occupational burnout were analyzed in the logistic regression and expressed in terms of odds ratios (OR). Statistical significance was determined using the 95% confidence interval (CI) level. Workplace bullying was prevalent among Kaunas teachers (occasional - 8.3%, severe - 2.9%). Twenty-five percent of teachers suffered from psychological distress. High emotional exhaustion was found in 25.6% of them, high depersonalization in 10.6% and low personal achievement in 33.7% of cases. Almost a half of respondents (47.4%) reported job strain and 59.6% - low social support at work. Occasional and severe bullying was associated with psychological distress after adjusting to job strain, social support and emotional exhaustion, depersonalization, personal accomplishment (adjusted OR was 3.27, 95% CI: 1.56-6.84 for occasional and 4.98, 95% CI: 1.27-19.62 for severe bullying). Occasional and severe bullying were strong predictors for psychological distress. Burnout did not mediate those associations. The effect of job strain and low social support decreased to the insignificant level in the final model. Preventive measures are necessary to improve psychosocial working conditions in secondary education institutions. Int J Occup Med Environ Health 2017;30(4):629-640. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.
Forging a link between mentoring and collaboration: a new training model for implementation science.
Luke, Douglas A; Baumann, Ana A; Carothers, Bobbi J; Landsverk, John; Proctor, Enola K
2016-10-13
Training investigators for the rapidly developing field of implementation science requires both mentoring and scientific collaboration. Using social network descriptive analyses, visualization, and modeling, this paper presents results of an evaluation of the mentoring and collaborations fostered over time through the National Institute of Mental Health (NIMH) supported by Implementation Research Institute (IRI). Data were comprised of IRI participant self-reported collaborations and mentoring relationships, measured in three annual surveys from 2012 to 2014. Network descriptive statistics, visualizations, and network statistical modeling were conducted to examine patterns of mentoring and collaboration among IRI participants and to model the relationship between mentoring and subsequent collaboration. Findings suggest that IRI is successful in forming mentoring relationships among its participants, and that these mentoring relationships are related to future scientific collaborations. Exponential random graph network models demonstrated that mentoring received in 2012 was positively and significantly related to the likelihood of having a scientific collaboration 2 years later in 2014 (p = 0.001). More specifically, mentoring was significantly related to future collaborations focusing on new research (p = 0.009), grant submissions (p = 0.003), and publications (p = 0.017). Predictions based on the network model suggest that for every additional mentoring relationships established in 2012, the likelihood of a scientific collaboration 2 years later is increased by almost 7 %. These results support the importance of mentoring in implementation science specifically and team science more generally. Mentoring relationships were established quickly and early by the IRI core faculty. IRI fellows reported increasing scientific collaboration of all types over time, including starting new research, submitting new grants, presenting research results, and publishing peer-reviewed papers. Statistical network models demonstrated that mentoring was strongly and significantly related to subsequent scientific collaboration, which supported a core design principle of the IRI. Future work should establish the link between mentoring and scientific productivity. These results may be of interest to team science, as they suggest the importance of mentoring for future team collaborations, as well as illustrate the utility of network analysis for studying team characteristics and activities.
Kantardjiev, Alexander A
2015-04-05
A cluster of strongly interacting ionization groups in protein molecules with irregular ionization behavior is suggestive for specific structure-function relationship. However, their computational treatment is unconventional (e.g., lack of convergence in naive self-consistent iterative algorithm). The stringent evaluation requires evaluation of Boltzmann averaged statistical mechanics sums and electrostatic energy estimation for each microstate. irGPU: Irregular strong interactions in proteins--a GPU solver is novel solution to a versatile problem in protein biophysics--atypical protonation behavior of coupled groups. The computational severity of the problem is alleviated by parallelization (via GPU kernels) which is applied for the electrostatic interaction evaluation (including explicit electrostatics via the fast multipole method) as well as statistical mechanics sums (partition function) estimation. Special attention is given to the ease of the service and encapsulation of theoretical details without sacrificing rigor of computational procedures. irGPU is not just a solution-in-principle but a promising practical application with potential to entice community into deeper understanding of principles governing biomolecule mechanisms. © 2015 Wiley Periodicals, Inc.
Automated flare forecasting using a statistical learning technique
NASA Astrophysics Data System (ADS)
Yuan, Yuan; Shih, Frank Y.; Jing, Ju; Wang, Hai-Min
2010-08-01
We present a new method for automatically forecasting the occurrence of solar flares based on photospheric magnetic measurements. The method is a cascading combination of an ordinal logistic regression model and a support vector machine classifier. The predictive variables are three photospheric magnetic parameters, i.e., the total unsigned magnetic flux, length of the strong-gradient magnetic polarity inversion line, and total magnetic energy dissipation. The output is true or false for the occurrence of a certain level of flares within 24 hours. Experimental results, from a sample of 230 active regions between 1996 and 2005, show the accuracies of a 24-hour flare forecast to be 0.86, 0.72, 0.65 and 0.84 respectively for the four different levels. Comparison shows an improvement in the accuracy of X-class flare forecasting.
Stressors and life goals of caregivers of individuals with disabilities.
Raver, Sharon A; Michalek, Anne P M; Gillespie, Amy M
2011-01-01
Caregivers of individuals with disabilities can experience stress as they manage caregiving responsibilities while they attempt to balance family, work, and the satisfaction of their personal goals. In this pilot study, 31 caregivers of individuals with a variety of disabilities completed a quantitative-qualitative survey. A statistically significant relationship was found between the age and severity of disability of the family member receiving care, the length of time care had been provided, the educational level and the relationship of the caregiver to the family member and reported feelings of optimism, humbleness, quality of family relationships, financial concerns, loss of control, and hope. When life goals were probed, the most common reported were achieving financial stability, having a strong, healthy family, and experiencing happiness. The implications for supporting caregivers and their families are discussed.
Extended Intermarker Linkage Disequilibrium in the Afrikaners
Hall, Diana; Wijsman, Ellen M.; Roos, J. Louw; Gogos, Joseph A.; Karayiorgou, Maria
2002-01-01
In this study we conducted an investigation of the background level of linkage disequilibrium (LD) in the Afrikaner population to evaluate the appropriateness of this genetic isolate for mapping complex traits. We analyzed intermarker LD in 62 nuclear families using microsatellite markers covering extended chromosomal regions. The markers were selected to allow the first direct comparison of long-range LD in the Afrikaners to LD in other demographic groups. Using several statistical measures, we find significant evidence for LD in the Afrikaners extending remarkably over a 6-cM range. In contrast, LD decays significantly beyond 3-cM distances in the other founder and outbred populations examined. This study strongly supports the appropriateness of the Afrikaner population for genome-wide scans that exploit LD to map common, multigenic disorders. PMID:12045148
Extended intermarker linkage disequilibrium in the Afrikaners.
Hall, Diana; Wijsman, Ellen M; Roos, J Louw; Gogos, Joseph A; Karayiorgou, Maria
2002-06-01
In this study we conducted an investigation of the background level of linkage disequilibrium (LD) in the Afrikaner population to evaluate the appropriateness of this genetic isolate for mapping complex traits. We analyzed intermarker LD in 62 nuclear families using microsatellite markers covering extended chromosomal regions. The markers were selected to allow the first direct comparison of long-range LD in the Afrikaners to LD in other demographic groups. Using several statistical measures, we find significant evidence for LD in the Afrikaners extending remarkably over a 6-cM range. In contrast, LD decays significantly beyond 3-cM distances in the other founder and outbred populations examined. This study strongly supports the appropriateness of the Afrikaner population for genome-wide scans that exploit LD to map common, multigenic disorders.
How will oil palm expansion affect biodiversity?
Fitzherbert, Emily B; Struebig, Matthew J; Morel, Alexandra; Danielsen, Finn; Brühl, Carsten A; Donald, Paul F; Phalan, Ben
2008-10-01
Oil palm is one of the world's most rapidly increasing crops. We assess its contribution to tropical deforestation and review its biodiversity value. Oil palm has replaced large areas of forest in Southeast Asia, but land-cover change statistics alone do not allow an assessment of where it has driven forest clearance and where it has simply followed it. Oil palm plantations support much fewer species than do forests and often also fewer than other tree crops. Further negative impacts include habitat fragmentation and pollution, including greenhouse gas emissions. With rising demand for vegetable oils and biofuels, and strong overlap between areas suitable for oil palm and those of most importance for biodiversity, substantial biodiversity losses will only be averted if future oil palm expansion is managed to avoid deforestation.
Understanding Evaluation of Learning Support in Mathematics and Statistics
ERIC Educational Resources Information Center
MacGillivray, Helen; Croft, Tony
2011-01-01
With rapid and continuing growth of learning support initiatives in mathematics and statistics found in many parts of the world, and with the likelihood that this trend will continue, there is a need to ensure that robust and coherent measures are in place to evaluate the effectiveness of these initiatives. The nature of learning support brings…
Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts
Matsubu, John C.; Zhang, Shuyi; DeRita, Leo; ...
2016-09-19
The optimization of supported metal catalysts predominantly focuses on engineering the metal site, for which physical insights based on extensive theoretical and experimental contributions have enabled the rational design of active sites. Although it is well known that supports can influence the catalytic properties of metals, insights into how metal–support interactions can be exploited to optimize metal active-site properties are lacking. Here in this paper, we utilize in situ spectroscopy and microscopy to identify and characterize a support effect in oxide-supported heterogeneous Rh catalysts. This effect is characterized by strongly bound adsorbates (HCO x) on reducible oxide supports (TiO 2more » and Nb 2O 5) that induce oxygen-vacancy formation in the support and cause HCO x-functionalized encapsulation of Rh nanoparticles by the support. The encapsulation layer is permeable to reactants, stable under the reaction conditions and strongly influences the catalytic properties of Rh, which enables rational and dynamic tuning of CO 2-reduction selectivity.« less
Calabrese, William R; Rudick, Monica M; Simms, Leonard J; Clark, Lee Anna
2012-09-01
Recently, integrative, hierarchical models of personality and personality disorder (PD)--such as the Big Three, Big Four, and Big Five trait models--have gained support as a unifying dimensional framework for describing PD. However, no measures to date can simultaneously represent each of these potentially interesting levels of the personality hierarchy. To unify these measurement models psychometrically, we sought to develop Big Five trait scales within the Schedule for Nonadaptive and Adaptive Personality--Second Edition (SNAP-2). Through structural and content analyses, we examined relations between the SNAP-2, the Big Five Inventory (BFI), and the NEO Five-Factor Inventory (NEO-FFI) ratings in a large data set (N = 8,690), including clinical, military, college, and community participants. Results yielded scales consistent with the Big Four model of personality (i.e., Neuroticism, Conscientiousness, Introversion, and Antagonism) and not the Big Five, as there were insufficient items related to Openness. Resulting scale scores demonstrated strong internal consistency and temporal stability. Structural validity and external validity were supported by strong convergent and discriminant validity patterns between Big Four scale scores and other personality trait scores and expectable patterns of self-peer agreement. Descriptive statistics and community-based norms are provided. The SNAP-2 Big Four Scales enable researchers and clinicians to assess personality at multiple levels of the trait hierarchy and facilitate comparisons among competing big-trait models. PsycINFO Database Record (c) 2012 APA, all rights reserved.
Calabrese, William R.; Rudick, Monica M.; Simms, Leonard J.; Clark, Lee Anna
2012-01-01
Recently, integrative, hierarchical models of personality and personality disorder (PD)—such as the Big Three, Big Four and Big Five trait models—have gained support as a unifying dimensional framework for describing PD. However, no measures to date can simultaneously represent each of these potentially interesting levels of the personality hierarchy. To unify these measurement models psychometrically, we sought to develop Big Five trait scales within the Schedule for Adaptive and Nonadaptive Personality–2nd Edition (SNAP-2). Through structural and content analyses, we examined relations between the SNAP-2, Big Five Inventory (BFI), and NEO-Five Factor Inventory (NEO-FFI) ratings in a large data set (N = 8,690), including clinical, military, college, and community participants. Results yielded scales consistent with the Big Four model of personality (i.e., Neuroticism, Conscientiousness, Introversion, and Antagonism) and not the Big Five as there were insufficient items related to Openness. Resulting scale scores demonstrated strong internal consistency and temporal stability. Structural and external validity was supported by strong convergent and discriminant validity patterns between Big Four scale scores and other personality trait scores and expectable patterns of self-peer agreement. Descriptive statistics and community-based norms are provided. The SNAP-2 Big Four Scales enable researchers and clinicians to assess personality at multiple levels of the trait hierarchy and facilitate comparisons among competing “Big Trait” models. PMID:22250598
Kus, Tulay; Aktas, Gokmen; Ekici, Hatice; Elboga, Gulcin; Djamgoz, Sabire
2017-11-01
Illness perception has been suggested to have a significant effect on anxiety and depression in cancer patients. In this cross-sectional study, we aimed to evaluate this on Turkish breast cancer patients with follow-up periods up to 12 years. A total of 225 patients (with 6 months to 12 years follow-up) were recruited in this cross-sectional study. The patients were divided into three groups of follow-up: 6 months-2 years, 2-5 years, and >5 years. Beck Depression Inventory, Beck Anxiety Inventory, Duke-University of North Carolina Functional Social Support Questionnaire, and Brief Illness Perception Questionnaire were used to assess the depression, anxiety, functional social support (FSS), and illness perception, respectively. Statistical significance of the associations was analyzed using Spearman correlation, Student's t, Mann-Whitney U, and ANOVA tests. Rates of moderate-severe anxiety and depression scores were not correlated with follow-up period and disease stage, whereas all these parameters were associated significantly with FSS and age. Parameters of illness perception were also not correlated with follow-up period and stage of disease. However, illness perception scores were noticeably better with increments in FSS. Also, the parameters of illness perception were strongly associated with the depression/anxiety score. Illness perception is an important determinant of the depression/anxiety score in Turkish breast cancer patients.
Sub-poissonian photon statistics in the coherent state Jaynes-Cummings model in non-resonance
NASA Astrophysics Data System (ADS)
Zhang, Jia-tai; Fan, An-fu
1992-03-01
We study a model with a two-level atom (TLA) non-resonance interacting with a single-mode quantized cavity field (QCF). The photon number probability function, the mean photon number and Mandel's fluctuation parameter are calculated. The sub-Poissonian distributions of the photon statistics are obtained in non-resonance interaction. This statistical properties are strongly dependent on the detuning parameters.
Role of inflammatory mediators in patients with recurrent pregnancy loss.
Comba, Cihan; Bastu, Ercan; Dural, Ozlem; Yasa, Cenk; Keskin, Gulsah; Ozsurmeli, Mehmet; Buyru, Faruk; Serdaroglu, Hasan
2015-12-01
To examine interleukin-12 (IL-12), IL-18, IFN-γ, intracellular adhesion molecule-1 (ICAM-1), leukemia inhibitory factor (LIF), and migration inhibitory factor (MIF) levels in precisely-timed blood and endometrial tissue samples from women with idiopathic recurrent pregnancy loss (RPL). Case-control study. University hospital. Twenty-one women with RPL and 20 women with proven fertility (controls). Primary endometrial cells and blood samples during the midsecretory phase (days 19-23). Detection of IL-12, IL-18, IFN-γ, ICAM-1, LIF, and MIF via enzyme-linked immunosorbent assay in both blood and endometrial tissue samples. The blood and tissue levels of IL-12, IL-18, and IFN-γ were statistically significantly higher, and the blood and tissue levels of LIF and MIF were statistically significantly lower in patients with RPL. Only the level of tissue ICAM-1 was higher in patients with RPL. There was a strong correlation between blood and tissue level measurements of IL-12, IL-18, LIF, and MIF. Our findings support the hypothesis that inflammatory processes may contribute to pregnancy loss, possibly through their role in implantation. We found that blood and tissue levels of IL-18, LIF, and MIF, and tissue levels of IL-12, IFN-γ, and ICAM-1 have statistically significant prognostic relevance. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Raeissi, Pouran; Sharifi, Marziye; Khosravizadeh, Omid; Heidari, Mohammad
2017-01-01
Background: Patient safety culture plays an important role in healthcare systems, especially in chemotherapy and oncology departments (CODs), and its assessment can help to improve quality of services and hospital care. Objective: This study aimed to evaluate and compare items and dimensions of patient safety culture in the CODs of selected teaching hospitals of Iran and Tehran University of Medical Sciences. Materials and Methods: This descriptive-analytical cross-sectional survey was conducted during a six-month period on 270 people from chemotherapy and oncology departments selected through a cluster sampling method. All participants answered the standard questionnaire for “Hospital Survey of Patient Safety Culture” (HSOPSC). Statistical analyses were performed using SPSS/18 software. Results: The average score for patient safety culture was three for the majority of the studied CODs. Statistically significant differences were observed for supervisor actions, teamwork within various units, feedback and communications about errors, and the level of hospital management support. (p<0.05). Relationships between studied hospitals and patient safety culture were not statistically significant (p>0.05). Conclusion: Our results showed that the overall status of patient safety culture is not good in the studied CODs. In particular, teamwork across different units and organizational learning with continuous improvement were the only two properly operating items among 12 dimensions of patient safety culture. Therefore, systematic interventions are strongly required to promote communication. PMID:29072411
Determinants of Judgments of Explanatory Power: Credibility, Generality, and Statistical Relevance.
Colombo, Matteo; Bucher, Leandra; Sprenger, Jan
2017-01-01
Explanation is a central concept in human psychology. Drawing upon philosophical theories of explanation, psychologists have recently begun to examine the relationship between explanation, probability and causality. Our study advances this growing literature at the intersection of psychology and philosophy of science by systematically investigating how judgments of explanatory power are affected by (i) the prior credibility of an explanatory hypothesis, (ii) the causal framing of the hypothesis, (iii) the perceived generalizability of the explanation, and (iv) the relation of statistical relevance between hypothesis and evidence. Collectively, the results of our five experiments support the hypothesis that the prior credibility of a causal explanation plays a central role in explanatory reasoning: first, because of the presence of strong main effects on judgments of explanatory power, and second, because of the gate-keeping role it has for other factors. Highly credible explanations are not susceptible to causal framing effects, but they are sensitive to the effects of normatively relevant factors: the generalizability of an explanation, and its statistical relevance for the evidence. These results advance current literature in the philosophy and psychology of explanation in three ways. First, they yield a more nuanced understanding of the determinants of judgments of explanatory power, and the interaction between these factors. Second, they show the close relationship between prior beliefs and explanatory power. Third, they elucidate the nature of abductive reasoning.
Determinants of Judgments of Explanatory Power: Credibility, Generality, and Statistical Relevance
Colombo, Matteo; Bucher, Leandra; Sprenger, Jan
2017-01-01
Explanation is a central concept in human psychology. Drawing upon philosophical theories of explanation, psychologists have recently begun to examine the relationship between explanation, probability and causality. Our study advances this growing literature at the intersection of psychology and philosophy of science by systematically investigating how judgments of explanatory power are affected by (i) the prior credibility of an explanatory hypothesis, (ii) the causal framing of the hypothesis, (iii) the perceived generalizability of the explanation, and (iv) the relation of statistical relevance between hypothesis and evidence. Collectively, the results of our five experiments support the hypothesis that the prior credibility of a causal explanation plays a central role in explanatory reasoning: first, because of the presence of strong main effects on judgments of explanatory power, and second, because of the gate-keeping role it has for other factors. Highly credible explanations are not susceptible to causal framing effects, but they are sensitive to the effects of normatively relevant factors: the generalizability of an explanation, and its statistical relevance for the evidence. These results advance current literature in the philosophy and psychology of explanation in three ways. First, they yield a more nuanced understanding of the determinants of judgments of explanatory power, and the interaction between these factors. Second, they show the close relationship between prior beliefs and explanatory power. Third, they elucidate the nature of abductive reasoning. PMID:28928679
Regier, Jerome C.; Mitter, Charles; Zwick, Andreas; Bazinet, Adam L.; Cummings, Michael P.; Kawahara, Akito Y.; Sohn, Jae-Cheon; Zwickl, Derrick J.; Cho, Soowon; Davis, Donald R.; Baixeras, Joaquin; Brown, John; Parr, Cynthia; Weller, Susan; Lees, David C.; Mitter, Kim T.
2013-01-01
Background Higher-level relationships within the Lepidoptera, and particularly within the species-rich subclade Ditrysia, are generally not well understood, although recent studies have yielded progress. We present the most comprehensive molecular analysis of lepidopteran phylogeny to date, focusing on relationships among superfamilies. Methodology / Principal Findings 483 taxa spanning 115 of 124 families were sampled for 19 protein-coding nuclear genes, from which maximum likelihood tree estimates and bootstrap percentages were obtained using GARLI. Assessment of heuristic search effectiveness showed that better trees and higher bootstrap percentages probably remain to be discovered even after 1000 or more search replicates, but further search proved impractical even with grid computing. Other analyses explored the effects of sampling nonsynonymous change only versus partitioned and unpartitioned total nucleotide change; deletion of rogue taxa; and compositional heterogeneity. Relationships among the non-ditrysian lineages previously inferred from morphology were largely confirmed, plus some new ones, with strong support. Robust support was also found for divergences among non-apoditrysian lineages of Ditrysia, but only rarely so within Apoditrysia. Paraphyly for Tineoidea is strongly supported by analysis of nonsynonymous-only signal; conflicting, strong support for tineoid monophyly when synonymous signal was added back is shown to result from compositional heterogeneity. Conclusions / Significance Support for among-superfamily relationships outside the Apoditrysia is now generally strong. Comparable support is mostly lacking within Apoditrysia, but dramatically increased bootstrap percentages for some nodes after rogue taxon removal, and concordance with other evidence, strongly suggest that our picture of apoditrysian phylogeny is approximately correct. This study highlights the challenge of finding optimal topologies when analyzing hundreds of taxa. It also shows that some nodes get strong support only when analysis is restricted to nonsynonymous change, while total change is necessary for strong support of others. Thus, multiple types of analyses will be necessary to fully resolve lepidopteran phylogeny. PMID:23554903
Deno, Minako; Tashiro, Mie; Miyashita, Mitsunori; Asakage, Takahiro; Takahashi, Koji; Saito, Kenich; Busujima, Yasunobu; Mori, Yoshiyuki; Saito, Hiroto; Ichikawa, Yuji
2012-02-01
Although social support has been recognized as an important factor in the quality of life of head and neck cancer patients, there has been little investigation of the buffering effect of social support on these patients' social distress or of the coping skill of self-efficacy. The aim of this study was to examine how social support and self-efficacy mediate the relationship between social distress and emotional distress in head and neck cancer patients. Two hundred twenty-five head and neck cancer patients completed our questionnaire (effective response rate, 92.2%). Of these, 129 (57.3%) had facial disfigurement. These participants responded to questions about perception of social distress, social support, self-efficacy, and emotional distress (depression and anxiety). We used structural equation modeling for statistical analysis. The fit indices of this model were excellent (χ2 (7) = 9.147, p = 0.242, goodness of fit index (GFI) = 0.981, adjusted goodness of fit index (AGFI) = 0.922, comparative fit index (CFI) = 0.993, root mean square error of approximation (RMSEA) = 0.049). Self-efficacy strongly buffered the negative influence of social distress on emotional distress. Social support from family members did not have a direct or indirect influence on emotional distress. Social support from friends was related to lower social distress and higher emotional distress. Our findings suggest that self-efficacy might confound the relationship between social support and emotional distress, and that different sources of social support might play different roles in the mediation of social distress on emotional distress. Copyright © 2010 John Wiley & Sons, Ltd.
Fuochi, G; Foà, C
2018-03-01
Quality of life, coping strategies, social support and self-efficacy are important psychosocial variables strongly affecting the experience of acute myocardial infarction (AMI) in women. To gain a more in-depth understanding of how coping strategies, self-efficacy, quality of life and social support shape women's adjustment to AMI. Mixed methods study. Quantitative data were collected through a standardised questionnaire on coping strategies, self-efficacy, quality of life and social support. Qualitative data stemmed from 57 semistructured interviews conducted with post-AMI female patients on related topics. Quantitative data were analysed with unpaired two-sample t-tests on the means, comparing women who experienced AMI (N = 77) with a control group of women who did not have AMI (N = 173), and pairwise correlations on the AMI sample. Qualitative data were grouped into coding families and analysed through thematic content analysis. Qualitative and quantitative results were then integrated, for different age groups. Quantitative results indicated statistically significant differences between women who experienced AMI and the control group: the former showed lower self-perceived health, perceived social support and social support coping, but greater self-efficacy, use of acceptance, avoidance and religious coping. Pairwise correlations showed that avoidance coping strategy was negatively correlated with quality of life, while the opposite was true for problem-oriented coping, perceived social support and self-efficacy. Qualitative results extended and confirmed quantitative results, except for coping strategies: avoidance coping seemed more present than reported in the standardised measures. Mixed methods provide understanding of the importance of social support, self-efficacy and less avoidant coping strategies to women's adjustment to AMI. Women need support from health professionals with knowledge of these topics, to facilitate their adaptation to AMI. © 2017 Nordic College of Caring Science.
Statistical Learning in a Natural Language by 8-Month-Old Infants
Pelucchi, Bruna; Hay, Jessica F.; Saffran, Jenny R.
2013-01-01
Numerous studies over the past decade support the claim that infants are equipped with powerful statistical language learning mechanisms. The primary evidence for statistical language learning in word segmentation comes from studies using artificial languages, continuous streams of synthesized syllables that are highly simplified relative to real speech. To what extent can these conclusions be scaled up to natural language learning? In the current experiments, English-learning 8-month-old infants’ ability to track transitional probabilities in fluent infant-directed Italian speech was tested (N = 72). The results suggest that infants are sensitive to transitional probability cues in unfamiliar natural language stimuli, and support the claim that statistical learning is sufficiently robust to support aspects of real-world language acquisition. PMID:19489896
Statistical learning in a natural language by 8-month-old infants.
Pelucchi, Bruna; Hay, Jessica F; Saffran, Jenny R
2009-01-01
Numerous studies over the past decade support the claim that infants are equipped with powerful statistical language learning mechanisms. The primary evidence for statistical language learning in word segmentation comes from studies using artificial languages, continuous streams of synthesized syllables that are highly simplified relative to real speech. To what extent can these conclusions be scaled up to natural language learning? In the current experiments, English-learning 8-month-old infants' ability to track transitional probabilities in fluent infant-directed Italian speech was tested (N = 72). The results suggest that infants are sensitive to transitional probability cues in unfamiliar natural language stimuli, and support the claim that statistical learning is sufficiently robust to support aspects of real-world language acquisition.
Electrical engineering research support for FDOT Traffic Statistics Office
DOT National Transportation Integrated Search
2010-03-01
The aim of this project was to provide electrical engineering support for the telemetered traffic monitoring sites (TTMSs) operated by the Statistics Office of the Florida Department of Transportation. This project was a continuation of project BD-54...
Parent and Friend Social Support and Adolescent Hope.
Mahon, Noreen E; Yarcheski, Adela
2017-04-01
The purpose of this study was to conduct two meta-analyses. The first examined social support from parents in relation to adolescent hope, and the second examined social support from friends in relation to adolescent hope. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for the literature reviewed, nine published studies or doctoral dissertations completed between 1990 and 2014 met the inclusion criteria. Using meta-analytic techniques and the mean weighted r statistic, the results indicated that social support from friends had a stronger mean effect size (ES = .31) than social support from parents (ES = .21); there was a statistically significant difference between the two ESs. Two of the four moderators for the parent social support-adolescent hope relationship were statistically significant. They were quality score and health status. Implications for school nurses and nurses in all settings are addressed, and conclusions are drawn based on the findings.
Multi-particle correlations in transverse momenta from statistical clusters
NASA Astrophysics Data System (ADS)
Bialas, Andrzej; Bzdak, Adam
2016-09-01
We evaluate n-particle (n = 2 , 3 , 4 , 5) transverse momentum correlations for pions and kaons following from the decay of statistical clusters. These correlation functions could provide strong constraints on a possible existence of thermal clusters in the process of particle production.
Double-slit experiment with single wave-driven particles and its relation to quantum mechanics.
Andersen, Anders; Madsen, Jacob; Reichelt, Christian; Rosenlund Ahl, Sonja; Lautrup, Benny; Ellegaard, Clive; Levinsen, Mogens T; Bohr, Tomas
2015-07-01
In a thought-provoking paper, Couder and Fort [Phys. Rev. Lett. 97, 154101 (2006)] describe a version of the famous double-slit experiment performed with droplets bouncing on a vertically vibrated fluid surface. In the experiment, an interference pattern in the single-particle statistics is found even though it is possible to determine unambiguously which slit the walking droplet passes. Here we argue, however, that the single-particle statistics in such an experiment will be fundamentally different from the single-particle statistics of quantum mechanics. Quantum mechanical interference takes place between different classical paths with precise amplitude and phase relations. In the double-slit experiment with walking droplets, these relations are lost since one of the paths is singled out by the droplet. To support our conclusions, we have carried out our own double-slit experiment, and our results, in particular the long and variable slit passage times of the droplets, cast strong doubt on the feasibility of the interference claimed by Couder and Fort. To understand theoretically the limitations of wave-driven particle systems as analogs to quantum mechanics, we introduce a Schrödinger equation with a source term originating from a localized particle that generates a wave while being simultaneously guided by it. We show that the ensuing particle-wave dynamics can capture some characteristics of quantum mechanics such as orbital quantization. However, the particle-wave dynamics can not reproduce quantum mechanics in general, and we show that the single-particle statistics for our model in a double-slit experiment with an additional splitter plate differs qualitatively from that of quantum mechanics.
ERIC Educational Resources Information Center
National Science Foundation, Washington, DC. Div. of Science Resources Studies.
This report for fiscal year 1975 presents the statistical tables related to federal support for academic science. Names of recipients and their geographical location are included. Information is also given on research and development support to federally-funded centers and non-profit research organizations. (SA)
Potentiation Following Ballistic and Nonballistic Complexes: The Effect of Strength Level.
Suchomel, Timothy J; Sato, Kimitake; DeWeese, Brad H; Ebben, William P; Stone, Michael H
2016-07-01
Suchomel, TJ, Sato, K, DeWeese, BH, Ebben, WP, and Stone, MH. Potentiation following ballistic and nonballistic complexes: the effect of strength level. J Strength Cond Res 30(7): 1825-1833, 2016-The purpose of this study was to compare the temporal profile of strong and weak subjects during ballistic and nonballistic potentiation complexes. Eight strong (relative back squat = 2.1 ± 0.1 times body mass) and 8 weak (relative back squat = 1.6 ± 0.2 times body mass) males performed squat jumps immediately and every minute up to 10 minutes following potentiation complexes that included ballistic or nonballistic concentric-only half-squat (COHS) performed at 90% of their 1 repetition maximum COHS. Jump height (JH) and allometrically scaled peak power (PPa) were compared using a series of 2 × 12 repeated measures analyses of variance. No statistically significant strength level main effects for JH (p = 0.442) or PPa (p = 0.078) existed during the ballistic condition. In contrast, statistically significant main effects for time existed for both JH (p = 0.014) and PPa (p < 0.001); however, no statistically significant pairwise comparisons were present (p > 0.05). Statistically significant strength level main effects existed for PPa (p = 0.039) but not for JH (p = 0.137) during the nonballistic condition. Post hoc analysis revealed that the strong subjects produced statistically greater PPa than the weaker subjects (p = 0.039). Statistically significant time main effects existed for time existed for PPa (p = 0.015), but not for JH (p = 0.178). No statistically significant strength level × time interaction effects for JH (p = 0.319) or PPa (p = 0.203) were present for the ballistic or nonballistic conditions. Practical significance indicated by effect sizes and the relationships between maximum potentiation and relative strength suggest that stronger subjects potentiate earlier and to a greater extent than weaker subjects during ballistic and nonballistic potentiation complexes.
Karpathiou, Georgia; Da Cruz, Vanessa; Casteillo, Francois; Mobarki, Mousa; Dumollard, Jean Marc; Chauleur, Celine; Forest, Fabien; Prades, Jean Michel; Peoc'h, Michel
2017-04-01
FOXA1 is a major transcription factor involved in the action of human papilloma virus (HPV). However, it has been never studied in HPV-associated tumors. To investigate its expression in cervical and head and neck tumors. 63 cervical carcinomas/dysplasias and 152 head and neck squamous cell carcinomas (HNSCC) were immunohistochemically studied for the expression of FOXA1. 63.1% of cervical SCC and 40.7% of endocervical adenocarcinomas strongly expressed FOXA1. Most (90%) pre-invasive lesions (CIN3 and in situ adenocarcinomas) strongly expressed FOXA1 and this difference from invasive lesions was statistically significant (p=0.005). No association with clinicopathological factors was found. 51.3% of HNSCC expressed FOXA1. In these tumors, FOXA1 expression was associated with the non-keratinizing morphology but not with the HPV/p16 status neither other clinicopathological features. Of normal structures, salivary glands, endocervical glands and basal/parabasal cell layer of squamous epithelium of both uterine cervix and head and neck mucosa, all strongly expressed FOXA1. FOXA1 is expressed by basal cells of squamous epithelium, pre-invasion lesions of the uterine cervix and the head/neck and almost half invasive cervical and head/neck carcinomas, supporting its possible implication in HPV pathogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.
Savage, Matthew W; Scarduzio, Jennifer A; Lockwood Harris, Kate; Carlyle, Kellie E; Sheff, Sarah E
2017-06-01
This study experimentally examines the effects of participant sex, perpetrator sex, and severity of violence on perceptions of intimate partner violence (IPV) seriousness, sympathy toward the victim, and punishment preferences for the perpetrator. Participants (N = 449) were randomly assigned to a condition, exposed to a composite news story, and then completed a survey. Ratings of seriousness of IPV for stories with male perpetrators were significantly higher than ratings of seriousness for stories with female perpetrators. Men had significantly higher sympathy for female victims in any condition than for male victims in the weak or strong severity of violence conditions. Men's sympathy for male victims in the fatal severity of violence condition did not differ from their sympathy for female victims. Women had the least sympathy for female victims in the weak severity condition and men in the weak or strong severity conditions. Women reported significantly higher sympathy for female victims in the strong and fatal severity of violence conditions. Women's ratings of sympathy for male victims in the fatal severity of violence condition were statistically indistinguishable from any other group. Participants reported stronger punishment preferences for male perpetrators and this effect was magnified among men. Theoretical implications are presented with attention provided to practical considerations about support for public health services.
Is There a Cosmological Constant?
NASA Technical Reports Server (NTRS)
Kochanek, Christopher; Oliversen, Ronald J. (Technical Monitor)
2002-01-01
The grant contributed to the publication of 18 refereed papers and 5 conference proceedings. The primary uses of the funding have been for page charges, travel for invited talks related to the grant research, and the support of a graduate student, Charles Keeton. The refereed papers address four of the primary goals of the proposal: (1) the statistics of radio lenses as a probe of the cosmological model (#1), (2) the role of spiral galaxies as lenses (#3), (3) the effects of dust on statistics of lenses (#7, #8), and (4) the role of groups and clusters as lenses (#2, #6, #10, #13, #15, #16). Four papers (#4, #5, #11, #12) address general issues of lens models, calibrations, and the relationship between lens galaxies and nearby galaxies. One considered cosmological effects in lensing X-ray sources (#9), and two addressed issues related to the overall power spectrum and theories of gravity (#17, #18). Our theoretical studies combined with the explosion in the number of lenses and the quality of the data obtained for them is greatly increasing our ability to characterize and understand the lens population. We can now firmly conclude both from our study of the statistics of radio lenses and our survey of extinctions in individual lenses that the statistics of optically selected quasars were significantly affected by extinction. However, the limits on the cosmological constant remain at lambda < 0.65 at a 2-sigma confidence level, which is in mild conflict with the results of the Type la supernova surveys. We continue to find that neither spiral galaxies nor groups and clusters contribute significantly to the production of gravitational lenses. The lack of group and cluster lenses is strong evidence for the role of baryonic cooling in increasing the efficiency of galaxies as lenses compared to groups and clusters of higher mass but lower central density. Unfortunately for the ultimate objective of the proposal, improved constraints on the cosmological constant, the next large survey for gravitational lenses did not release its results during the term of the proposal. The research supported the career development. of six graduate students (polar, Fletcher, Herold, Keeton, Deng and Rusin) and two post-docs (Labor and Munoz).
f-lacunary statistical convergence of order (α, β)
NASA Astrophysics Data System (ADS)
Sengul, Hacer; Isik, Mahmut; Et, Mikail
2017-09-01
The main purpose of this paper is to introduce the concepts of f-lacunary statistical convergence of order (α, β) and strong f-lacunary summability of order (α, β) of sequences of real numbers for 0 <α ≤ β ≤ 1, where f is an unbounded modulus.
Statistical Reference Datasets
National Institute of Standards and Technology Data Gateway
Statistical Reference Datasets (Web, free access) The Statistical Reference Datasets is also supported by the Standard Reference Data Program. The purpose of this project is to improve the accuracy of statistical software by providing reference datasets with certified computational results that enable the objective evaluation of statistical software.
What You Learn is What You See: Using Eye Movements to Study Infant Cross-Situational Word Learning
Smith, Linda
2016-01-01
Recent studies show that both adults and young children possess powerful statistical learning capabilities to solve the word-to-world mapping problem. However, the underlying mechanisms that make statistical learning possible and powerful are not yet known. With the goal of providing new insights into this issue, the research reported in this paper used an eye tracker to record the moment-by-moment eye movement data of 14-month-old babies in statistical learning tasks. Various measures are applied to such fine-grained temporal data, such as looking duration and shift rate (the number of shifts in gaze from one visual object to the other) trial by trial, showing different eye movement patterns between strong and weak statistical learners. Moreover, an information-theoretic measure is developed and applied to gaze data to quantify the degree of learning uncertainty trial by trial. Next, a simple associative statistical learning model is applied to eye movement data and these simulation results are compared with empirical results from young children, showing strong correlations between these two. This suggests that an associative learning mechanism with selective attention can provide a cognitively plausible model of cross-situational statistical learning. The work represents the first steps to use eye movement data to infer underlying real-time processes in statistical word learning. PMID:22213894
DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, Chang Wan; Choksi, Tej; Milligan, Cory
The strength of metal-support bonding in heterogeneous catalysts determines their thermal stability, therefore, a tremendous amount of effort has been expended to understand metal-support interactions. Herein, we report the discovery of an anomalous “strong metal-support bonding” between gold nanoparticles and “nano-engineered” Fe 3O 4 substrates by in-situ microscopy. During in-situ vacuum annealing of Au-Fe 3O 4 dumbbell-like nanoparticles, synthesized by the epitaxial growth of nano-Fe 3O 4 on Au nanoparticles, the gold nanoparticles transform into the monolayered gold thinfilms and wet the surface of nano-Fe 3O 4, as the surface reduction of nano-Fe 3O 4 proceeds. This phenomenon results frommore » a unique coupling of the size-and shape-dependent high surface reducibility of nano-Fe 3O 4 and the extremely strong adhesion between Au and the reduced Fe 3O 4. This strong-metal support bonding reveals the significance of controlling the metal oxide support size and morphology for optimizing metal-support bonding and, ultimately, for the development of improved catalysts and functional nanostructures.« less
Han, Chang Wan; Choksi, Tej; Milligan, Cory; Majumdar, Paulami; Manto, Michael; Cui, Yanran; Sang, Xiahan; Unocic, Raymond R; Zemlyanov, Dmitry; Wang, Chao; Ribeiro, Fabio H; Greeley, Jeffrey; Ortalan, Volkan
2017-08-09
The strength of metal-support bonding in heterogeneous catalysts determines their thermal stability, therefore, a tremendous amount of effort has been expended to understand metal-support interactions. Herein, we report the discovery of an anomalous "strong metal-support bonding" between gold nanoparticles and "nano-engineered" Fe 3 O 4 substrates by in situ microscopy. During in situ vacuum annealing of Au-Fe 3 O 4 dumbbell-like nanoparticles, synthesized by the epitaxial growth of nano-Fe 3 O 4 on Au nanoparticles, the gold nanoparticles transform into the gold thin films and wet the surface of nano-Fe 3 O 4 , as the surface reduction of nano-Fe 3 O 4 proceeds. This phenomenon results from a unique coupling of the size-and shape-dependent high surface reducibility of nano-Fe 3 O 4 and the extremely strong adhesion between Au and the reduced Fe 3 O 4 . This strong metal-support bonding reveals the significance of controlling the metal oxide support size and morphology for optimizing metal-support bonding and ultimately for the development of improved catalysts and functional nanostructures.
Han, Chang Wan; Choksi, Tej; Milligan, Cory; ...
2017-06-26
The strength of metal-support bonding in heterogeneous catalysts determines their thermal stability, therefore, a tremendous amount of effort has been expended to understand metal-support interactions. Herein, we report the discovery of an anomalous “strong metal-support bonding” between gold nanoparticles and “nano-engineered” Fe 3O 4 substrates by in-situ microscopy. During in-situ vacuum annealing of Au-Fe 3O 4 dumbbell-like nanoparticles, synthesized by the epitaxial growth of nano-Fe 3O 4 on Au nanoparticles, the gold nanoparticles transform into the monolayered gold thinfilms and wet the surface of nano-Fe 3O 4, as the surface reduction of nano-Fe 3O 4 proceeds. This phenomenon results frommore » a unique coupling of the size-and shape-dependent high surface reducibility of nano-Fe 3O 4 and the extremely strong adhesion between Au and the reduced Fe 3O 4. This strong-metal support bonding reveals the significance of controlling the metal oxide support size and morphology for optimizing metal-support bonding and, ultimately, for the development of improved catalysts and functional nanostructures.« less
a Statistical Theory of the Epilepsies.
NASA Astrophysics Data System (ADS)
Thomas, Kuryan
1988-12-01
A new physical and mathematical model for the epilepsies is proposed, based on the theory of bond percolation on finite lattices. Within this model, the onset of seizures in the brain is identified with the appearance of spanning clusters of neurons engaged in the spurious and uncontrollable electrical activity characteristic of seizures. It is proposed that the fraction of excitatory to inhibitory synapses can be identified with a bond probability, and that the bond probability is a randomly varying quantity displaying Gaussian statistics. The consequences of the proposed model to the treatment of the epilepsies is explored. The nature of the data on the epilepsies which can be acquired in a clinical setting is described. It is shown that such data can be analyzed to provide preliminary support for the bond percolation hypothesis, and to quantify the efficacy of anti-epileptic drugs in a treatment program. The results of a battery of statistical tests on seizure distributions are discussed. The physical theory of the electroencephalogram (EEG) is described, and extant models of the electrical activity measured by the EEG are discussed, with an emphasis on their physical behavior. A proposal is made to explain the difference between the power spectra of electrical activity measured with cranial probes and with the EEG. Statistical tests on the characteristic EEG manifestations of epileptic activity are conducted, and their results described. Computer simulations of a correlated bond percolating system are constructed. It is shown that the statistical properties of the results of such a simulation are strongly suggestive of the statistical properties of clinical data. The study finds no contradictions between the predictions of the bond percolation model and the observed properties of the available data. Suggestions are made for further research and for techniques based on the proposed model which may be used for tuning the effects of anti -epileptic drugs.
Grasgruber, Pavel; Sebera, Martin; Hrazdira, Eduard; Hrebickova, Sylva; Cacek, Jan
2016-01-01
Background The aim of this ecological study was to identify the main nutritional factors related to the prevalence of cardiovascular diseases (CVDs) in Europe, based on a comparison of international statistics. Design The mean consumption of 62 food items from the FAOSTAT database (1993–2008) was compared with the actual statistics of five CVD indicators in 42 European countries. Several other exogenous factors (health expenditure, smoking, body mass index) and the historical stability of results were also examined. Results We found exceptionally strong relationships between some of the examined factors, the highest being a correlation between raised cholesterol in men and the combined consumption of animal fat and animal protein (r=0.92, p<0.001). The most significant dietary correlate of low CVD risk was high total fat and animal protein consumption. Additional statistical analyses further highlighted citrus fruits, high-fat dairy (cheese) and tree nuts. Among other non-dietary factors, health expenditure showed by far the highest correlation coefficients. The major correlate of high CVD risk was the proportion of energy from carbohydrates and alcohol, or from potato and cereal carbohydrates. Similar patterns were observed between food consumption and CVD statistics from the period 1980–2000, which shows that these relationships are stable over time. However, we found striking discrepancies in men's CVD statistics from 1980 and 1990, which can probably explain the origin of the ‘saturated fat hypothesis’ that influenced public health policies in the following decades. Conclusion Our results do not support the association between CVDs and saturated fat, which is still contained in official dietary guidelines. Instead, they agree with data accumulated from recent studies that link CVD risk with the high glycaemic index/load of carbohydrate-based diets. In the absence of any scientific evidence connecting saturated fat with CVDs, these findings show that current dietary recommendations regarding CVDs should be seriously reconsidered. PMID:27680091
Monitoring the Earth System Grid Federation through the ESGF Dashboard
NASA Astrophysics Data System (ADS)
Fiore, S.; Bell, G. M.; Drach, B.; Williams, D.; Aloisio, G.
2012-12-01
The Climate Model Intercomparison Project, phase 5 (CMIP5) is a global effort coordinated by the World Climate Research Programme (WCRP) involving tens of modeling groups spanning 19 countries. It is expected the CMIP5 distributed data archive will total upwards of 3.5 petabytes, stored across several ESGF Nodes on four continents (North America, Europe, Asia, and Australia). The Earth System Grid Federation (ESGF) provides the IT infrastructure to support the CMIP5. In this regard, the monitoring of the distributed ESGF infrastructure represents a crucial part carried out by the ESGF Dashboard. The ESGF Dashboard is a software component of the ESGF stack, responsible for collecting key information about the status of the federation in terms of: 1) Network topology (peer-groups composition), 2) Node type (host/services mapping), 3) Registered users (including their Identity Providers), 4) System metrics (e.g., round-trip time, service availability, CPU, memory, disk, processes, etc.), 5) Download metrics (both at the Node and federation level). The last class of information is very important since it provides a strong insight of the CMIP5 experiment: the data usage statistics. In this regard, CMCC and LLNL have developed a data analytics management system for the analysis of both node-level and federation-level data usage statistics. It provides data usage statistics aggregated by project, model, experiment, variable, realm, peer node, time, ensemble, datasetname (including version), etc. The back-end of the system is able to infer the data usage information of the entire federation, by carrying out: - at node level: a 18-step reconciliation process on the peer node databases (i.e. node manager and publisher DB) which provides a 15-dimension datawarehouse with local statistics and - at global level: an aggregation process which federates the data usage statistics into a 16-dimension datawarehouse with federation-level data usage statistics. The front-end of the Dashboard system exploits a web desktop approach, which joins the pervasivity of a web application with the flexibility of a desktop one.
SOCR Analyses – an Instructional Java Web-based Statistical Analysis Toolkit
Chu, Annie; Cui, Jenny; Dinov, Ivo D.
2011-01-01
The Statistical Online Computational Resource (SOCR) designs web-based tools for educational use in a variety of undergraduate courses (Dinov 2006). Several studies have demonstrated that these resources significantly improve students' motivation and learning experiences (Dinov et al. 2008). SOCR Analyses is a new component that concentrates on data modeling and analysis using parametric and non-parametric techniques supported with graphical model diagnostics. Currently implemented analyses include commonly used models in undergraduate statistics courses like linear models (Simple Linear Regression, Multiple Linear Regression, One-Way and Two-Way ANOVA). In addition, we implemented tests for sample comparisons, such as t-test in the parametric category; and Wilcoxon rank sum test, Kruskal-Wallis test, Friedman's test, in the non-parametric category. SOCR Analyses also include several hypothesis test models, such as Contingency tables, Friedman's test and Fisher's exact test. The code itself is open source (http://socr.googlecode.com/), hoping to contribute to the efforts of the statistical computing community. The code includes functionality for each specific analysis model and it has general utilities that can be applied in various statistical computing tasks. For example, concrete methods with API (Application Programming Interface) have been implemented in statistical summary, least square solutions of general linear models, rank calculations, etc. HTML interfaces, tutorials, source code, activities, and data are freely available via the web (www.SOCR.ucla.edu). Code examples for developers and demos for educators are provided on the SOCR Wiki website. In this article, the pedagogical utilization of the SOCR Analyses is discussed, as well as the underlying design framework. As the SOCR project is on-going and more functions and tools are being added to it, these resources are constantly improved. The reader is strongly encouraged to check the SOCR site for most updated information and newly added models. PMID:21546994
Illness Perceptions in Patients of Schizophrenia: A Preliminary Investigation from Lahore, Pakistan.
Hussain, Sadia; Imran, Nazish; Hotiana, Usman Amin; Mazhar, Nauman; Asif, Aftab
2017-01-01
Patient's perception of their illness influences their healthcare decisions. The objectives of this study were to explore patient's own beliefs about their illness (Schizophrenia) and perceived social support, and its impact on their attitudes toward pharmacological treatment in Lahore, Pakistan. This study was conducted at Mayo Hospital Lahore from March to September 2016. Hundred individuals suffering from Schizophrenia completed four questionnaires; a socio-demographic questionnaire, the Illness Perception Questionnaire for Schizophrenia(IPQ-S), Drug attitude Inventory-10 (DAI) and Multidimensional Scale of Perceived Social Support (PSS). Stress, family problems, lack of friends & financial worries were endorsed strongly by patients as cause of their mental illness. Ambiguity regarding their mental illness duration and personal control was observed. Patients' perceived significant negative consequences, negative emotional response, as well as had poor understanding of their mental illness and treatment effectiveness. Statistically significant gender differences in treatment control and illness coherence subscales of IPQS were observed. Drug attitude inventory was positively correlated with Treatment control subscale (p < .01) and negatively correlated with Illness coherence subscale of IPQS (p < .05). The negative consequences subscale and perceived social support was negatively correlated (p < .01). Patient's perception about their own illness is predictor of their drug taking attitude and perceived social support. Study results should help to develop new interventions to correct inaccurate beliefs in patients with schizophrenia to improve illness outcome.
Holden, Libby; Lee, Christina; Hockey, Richard; Ware, Robert S; Dobson, Annette J
2014-12-01
This study aimed to validate a 6-item 1-factor global measure of social support developed from the Medical Outcomes Study Social Support Survey (MOS-SSS) for use in large epidemiological studies. Data were obtained from two large population-based samples of participants in the Australian Longitudinal Study on Women's Health. The two cohorts were aged 53-58 and 28-33 years at data collection (N = 10,616 and 8,977, respectively). Items selected for the 6-item 1-factor measure were derived from the factor structure obtained from unpublished work using an earlier wave of data from one of these cohorts. Descriptive statistics, including polychoric correlations, were used to describe the abbreviated scale. Cronbach's alpha was used to assess internal consistency and confirmatory factor analysis to assess scale validity. Concurrent validity was assessed using correlations between the new 6-item version and established 19-item version, and other concurrent variables. In both cohorts, the new 6-item 1-factor measure showed strong internal consistency and scale reliability. It had excellent goodness-of-fit indices, similar to those of the established 19-item measure. Both versions correlated similarly with concurrent measures. The 6-item 1-factor MOS-SSS measures global functional social support with fewer items than the established 19-item measure.
Sun, Miao-Miao; Han, Liang; Zhang, Fu-Kai; Zhou, Dong-Hui; Wang, Shu-Qing; Ma, Jun; Zhu, Xing-Quan; Liu, Guo-Hua
2018-01-01
Marshallagia marshalli (Nematoda: Trichostrongylidae) infection can lead to serious parasitic gastroenteritis in sheep, goat, and wild ruminant, causing significant socioeconomic losses worldwide. Up to now, the study concerning the molecular biology of M. marshalli is limited. Herein, we sequenced the complete mitochondrial (mt) genome of M. marshalli and examined its phylogenetic relationship with selected members of the superfamily Trichostrongyloidea using Bayesian inference (BI) based on concatenated mt amino acid sequence datasets. The complete mt genome sequence of M. marshalli is 13,891 bp, including 12 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. All protein-coding genes are transcribed in the same direction. Phylogenetic analyses based on concatenated amino acid sequences of the 12 protein-coding genes supported the monophylies of the families Haemonchidae, Molineidae, and Dictyocaulidae with strong statistical support, but rejected the monophyly of the family Trichostrongylidae. The determination of the complete mt genome sequence of M. marshalli provides novel genetic markers for studying the systematics, population genetics, and molecular epidemiology of M. marshalli and its congeners.
Six centuries of May-July precipitation in Cyprus from tree rings
NASA Astrophysics Data System (ADS)
Touchan, Ramzi; Christou, Andreas K.; Meko, David M.
2014-12-01
A May-July precipitation nested reconstruction for the period AD 1415-2010 was developed from multi-century tree-ring records of Pinus nigra, Pinus brutia, and Cedrus brevifolia for Cyprus. Calibration and verification statistics for the period 1917-2010 show a good level of skill, and split-sample validation over 1917-2010 supports temporal stability of the tree-ring signal for precipitation. Smoothed annual time series of reconstructed precipitation and a tally of drought events in a moving time window indicate that the calibration period is not representative of the full range of drought variability. While convective precipitation in the warm season may be driven strongly by local factors, composite maps of geopotential height anomaly for dry years and wet years support large-scale atmospheric-flow influence related to height anomalies over the broader region of northeast Africa and the eastern Mediterranean. Emerging positive trend in reconstruction residuals may be an early sign of exacerbation of drought stress on trees by recent warming in May-July. Future warming expected from increases in greenhouse gases poses a threat to forest resources in Cyprus and elsewhere in the Mediterranean.
Vocal repertoire of the social giant otter.
Leuchtenberger, Caroline; Sousa-Lima, Renata; Duplaix, Nicole; Magnusson, William E; Mourão, Guilherme
2014-11-01
According to the "social intelligence hypothesis," species with complex social interactions have more sophisticated communication systems. Giant otters (Pteronura brasiliensis) live in groups with complex social interactions. It is likely that the vocal communication of giant otters is more sophisticated than previous studies suggest. The objectives of the current study were to describe the airborne vocal repertoire of giant otters in the Pantanal area of Brazil, to analyze call types within different behavioral contexts, and to correlate vocal complexity with level of sociability of mustelids to verify whether or not the result supports the social intelligence hypothesis. The behavior of nine giant otters groups was observed. Vocalizations recorded were acoustically and statistically analyzed to describe the species' repertoire. The repertoire was comprised by 15 sound types emitted in different behavioral contexts. The main behavioral contexts of each sound type were significantly associated with the acoustic variable ordination of different sound types. A strong correlation between vocal complexity and sociability was found for different species, suggesting that the communication systems observed in the family mustelidae support the social intelligence hypothesis.
Steel, Brent S; Pierce, John C; Warner, Rebecca L; Lovrich, Nicholas P
2015-03-01
The 2013 Pacific Coast Action Plan on Climate and Energy signed by the Governors of California, Oregon, and Washington and the Premier of British Columbia launched a broadly announced public commitment to reduce greenhouse gas emissions through multiple strategies. Those strategies include the development and increased use of renewable energy sources. The initiative recognized that citizens are both a central component in abating greenhouse gas emissions with regard to their energy use behaviors, and are important participants in the public policymaking process at both state and local levels of government. The study reported here examines whether either support or opposition to state government leadership in the development of alternative energy technologies can be explained by environmental values as measured by the New Ecological Paradigm (NEP). The research results are based on mail surveys of randomly selected households conducted throughout Oregon and Washington in late 2009 and early 2010. Findings suggest that younger and more highly educated respondents are significantly more likely than older and less educated respondents to either support or strongly support government policies to promote bioenergy, wind, geothermal, and solar energy. Those respondents with higher NEP scores are also more supportive of government promotion of wind, geothermal, and solar technologies than are those with lower NEP scores. Support for wave energy does not show a statistical correlation with environmental values, maybe a reflection of this technology's nascent level of development. The paper concludes with a consideration of the implications of these findings for environmental management.
NASA Astrophysics Data System (ADS)
Steel, Brent S.; Pierce, John C.; Warner, Rebecca L.; Lovrich, Nicholas P.
2015-03-01
The 2013 Pacific Coast Action Plan on Climate and Energy signed by the Governors of California, Oregon, and Washington and the Premier of British Columbia launched a broadly announced public commitment to reduce greenhouse gas emissions through multiple strategies. Those strategies include the development and increased use of renewable energy sources. The initiative recognized that citizens are both a central component in abating greenhouse gas emissions with regard to their energy use behaviors, and are important participants in the public policymaking process at both state and local levels of government. The study reported here examines whether either support or opposition to state government leadership in the development of alternative energy technologies can be explained by environmental values as measured by the New Ecological Paradigm (NEP). The research results are based on mail surveys of randomly selected households conducted throughout Oregon and Washington in late 2009 and early 2010. Findings suggest that younger and more highly educated respondents are significantly more likely than older and less educated respondents to either support or strongly support government policies to promote bioenergy, wind, geothermal, and solar energy. Those respondents with higher NEP scores are also more supportive of government promotion of wind, geothermal, and solar technologies than are those with lower NEP scores. Support for wave energy does not show a statistical correlation with environmental values, maybe a reflection of this technology's nascent level of development. The paper concludes with a consideration of the implications of these findings for environmental management.
Systematic comparisons between PRISM version 1.0.0, BAP, and CSMIP ground-motion processing
Kalkan, Erol; Stephens, Christopher
2017-02-23
A series of benchmark tests was run by comparing results of the Processing and Review Interface for Strong Motion data (PRISM) software version 1.0.0 to Basic Strong-Motion Accelerogram Processing Software (BAP; Converse and Brady, 1992), and to California Strong Motion Instrumentation Program (CSMIP) processing (Shakal and others, 2003, 2004). These tests were performed by using the MatLAB implementation of PRISM, which is equivalent to its public release version in Java language. Systematic comparisons were made in time and frequency domains of records processed in PRISM and BAP, and in CSMIP, by using a set of representative input motions with varying resolutions, frequency content, and amplitudes. Although the details of strong-motion records vary among the processing procedures, there are only minor differences among the waveforms for each component and within the frequency passband common to these procedures. A comprehensive statistical evaluation considering more than 1,800 ground-motion components demonstrates that differences in peak amplitudes of acceleration, velocity, and displacement time series obtained from PRISM and CSMIP processing are equal to or less than 4 percent for 99 percent of the data, and equal to or less than 2 percent for 96 percent of the data. Other statistical measures, including the Euclidian distance (L2 norm) and the windowed root mean square level of processed time series, also indicate that both processing schemes produce statistically similar products.
Crohn’s Disease and Genetic Hitchhiking at IBD5
Huff, Chad D.; Witherspoon, David J.; Zhang, Yuhua; Gatenbee, Chandler; Denson, Lee A.; Kugathasan, Subra; Hakonarson, Hakon; Whiting, April; Davis, Chadwick T.; Wu, Wilfred; Xing, Jinchuan; Watkins, W. Scott; Bamshad, Michael J.; Bradfield, Jonathan P.; Bulayeva, Kazima; Simonson, Tatum S.; Jorde, Lynn B.; Guthery, Stephen L.
2012-01-01
Inflammatory bowel disease 5 (IBD5) is a 250 kb haplotype on chromosome 5 that is associated with an increased risk of Crohn’s disease in Europeans. The OCTN1 gene is centrally located on IBD5 and encodes a transporter of the antioxidant ergothioneine (ET). The 503F variant of OCTN1 is strongly associated with IBD5 and is a gain-of-function mutation that increases absorption of ET. Although 503F has been implicated as the variant potentially responsible for Crohn’s disease susceptibility at IBD5, there is little evidence beyond statistical association to support its role in disease causation. We hypothesize that 503F is a recent adaptation in Europeans that swept to relatively high frequency and that disease association at IBD5 results not from 503F itself, but from one or more nearby hitchhiking variants, in the genes IRF1 or IL5. To test for evidence of recent positive selection on the 503F allele, we employed the iHS statistic, which was significant in the European CEU HapMap population (P = 0.0007) and European Human Genome Diversity Panel populations (P ≤ 0.01). To evaluate the hypothesis of disease-variant hitchhiking, we performed haplotype association tests on high-density microarray data in a sample of 1,868 Crohn’s disease cases and 5,550 controls. We found that 503F haplotypes with recombination breakpoints between OCTN1 and IRF1 or IL5 were not associated with disease (odds ratio [OR]: 1.05, P = 0.21). In contrast, we observed strong disease association for 503F haplotypes with no recombination between these three genes (OR: 1.24, P = 2.6 × 10−8), as expected if the sweeping haplotype harbored one or more disease-causing mutations in IRF1 or IL5. To further evaluate these disease-gene candidates, we obtained expression data from lower gastrointestinal biopsies of healthy individuals and Crohn’s disease patients. We observed a 72% increase in gene expression of IRF1 among Crohn’s disease patients (P = 0.0006) and no significant difference in expression of OCTN1. Collectively, these data indicate that the 503F variant has increased in frequency due to recent positive selection and that disease-causing variants in linkage disequilibrium with 503F have hitchhiked to relatively high frequency, thus forming the IBD5 risk haplotype. Finally, our association results and expression data support IRF1 as a strong candidate for Crohn’s disease causation. PMID:21816865
Unified picture of strong-coupling stochastic thermodynamics and time reversals
NASA Astrophysics Data System (ADS)
Aurell, Erik
2018-04-01
Strong-coupling statistical thermodynamics is formulated as the Hamiltonian dynamics of an observed system interacting with another unobserved system (a bath). It is shown that the entropy production functional of stochastic thermodynamics, defined as the log ratio of forward and backward system path probabilities, is in a one-to-one relation with the log ratios of the joint initial conditions of the system and the bath. A version of strong-coupling statistical thermodynamics where the system-bath interaction vanishes at the beginning and at the end of a process is, as is also weak-coupling stochastic thermodynamics, related to the bath initially in equilibrium by itself. The heat is then the change of bath energy over the process, and it is discussed when this heat is a functional of the system history alone. The version of strong-coupling statistical thermodynamics introduced by Seifert and Jarzynski is related to the bath initially in conditional equilibrium with respect to the system. This leads to heat as another functional of the system history which needs to be determined by thermodynamic integration. The log ratio of forward and backward system path probabilities in a stochastic process is finally related to log ratios of the initial conditions of a combined system and bath. It is shown that the entropy production formulas of stochastic processes under a general class of time reversals are given by the differences of bath energies in a larger underlying Hamiltonian system. The paper highlights the centrality of time reversal in stochastic thermodynamics, also in the case of strong coupling.
Strong biotic influences on regional patterns of climate regulation services
NASA Astrophysics Data System (ADS)
Serna-Chavez, H. M.; Swenson, N. G.; Weiser, M. D.; van Loon, E. E.; Bouten, W.; Davidson, M. D.; van Bodegom, P. M.
2017-05-01
Climate regulation services from forests are an important leverage in global-change mitigation treaties. Like most ecosystem services, climate regulation is the product of various ecological phenomena with unique spatial features. Elucidating which abiotic and biotic factors relate to spatial patterns of climate regulation services advances our understanding of what underlies climate-mitigation potential and its variation within and across ecosystems. Here we quantify and contrast the statistical relations between climate regulation services (albedo and evapotranspiration, primary productivity, and soil carbon) and abiotic and biotic factors. We focus on 16,955 forest plots in a regional extent across the eastern United States. We find the statistical effects of forest litter and understory carbon on climate regulation services to be as strong as those of temperature-precipitation interactions. These biotic factors likely influence climate regulation through changes in vegetation and canopy density, radiance scattering, and decomposition rates. We also find a moderate relation between leaf nitrogen traits and primary productivity at this regional scale. The statistical relation between climate regulation and temperature-precipitation ranges, seasonality, and climatic thresholds highlights a strong feedback with global climate change. Our assessment suggests the expression of strong biotic influences on climate regulation services at a regional, temperate extent. Biotic homogenization and management practices manipulating forest structure and succession will likely strongly impact climate-mitigation potential. The identity, strength, and direction of primary influences differed for each process involved in climate regulation. Hence, different abiotic and biotic factors are needed to monitor and quantify the full climate-mitigation potential of temperate forest ecosystems.
Southern Argentina Agile Meteor Radar: Initial assessment of gravity wave momentum fluxes
NASA Astrophysics Data System (ADS)
Fritts, D. C.; Janches, D.; Hocking, W. K.
2010-10-01
The Southern Argentina Agile Meteor Radar (SAAMER) was installed on Tierra del Fuego (53.8°S) in May 2008 and has been operational since that time. This paper describes tests of the SAAMER ability to measure gravity wave momentum fluxes and applications of this capability during different seasons. Test results for specified mean, tidal, and gravity wavefields, including tidal amplitudes and gravity wave momentum fluxes varying strongly with altitude and/or time, suggest that the distribution of meteors throughout the diurnal cycle and averaged over a month allows characterization of both monthly mean profiles and diurnal variations of the gravity wave momentum fluxes. Applications of the same methods for real data suggest confidence in the monthly mean profiles and the composite day diurnal variations of gravity wave momentum fluxes at altitudes where meteor counts are sufficient to yield good statistical fits to the data. Monthly mean zonal winds and gravity wave momentum fluxes exhibit anticorrelations consistent with those seen at other midlatitude and high-latitude radars during austral spring and summer, when no strong local gravity wave sources are apparent. When stratospheric variances are significantly enhanced over the Drake Passage “hot spot” during austral winter, however, MLT winds and momentum fluxes over SAAMER exhibit very different correlations that suggest that MLT dynamics are strongly influenced by strong local gravity wave sources within this “hot spot.” SAAMER measurements of mean zonal and meridional winds at these times and their differences from measurements at a conjugate site provide further support for the unusual momentum flux measurements.
The Surprisingly Modest Relationship between SES and Educational Achievement
ERIC Educational Resources Information Center
Harwell, Michael; Maeda, Yukiko; Bishop, Kyoungwon; Xie, Aolin
2017-01-01
Measures of socioeconomic status (SES) are routinely used in analyses of achievement data to increase statistical power, statistically control for the effects of SES, and enhance causality arguments under the premise that the SES-achievement relationship is moderate to strong. Empirical evidence characterizing the strength of the SES-achievement…
Computational Inquiry in Introductory Statistics
ERIC Educational Resources Information Center
Toews, Carl
2017-01-01
Inquiry-based pedagogies have a strong presence in proof-based undergraduate mathematics courses, but can be difficult to implement in courses that are large, procedural, or highly computational. An introductory course in statistics would thus seem an unlikely candidate for an inquiry-based approach, as these courses typically steer well clear of…
NASA Astrophysics Data System (ADS)
Acharya, S.; Kaplan, D. A.; Casey, S.; Cohen, M. J.; Jawitz, J. W.
2015-05-01
Self-organized landscape patterning can arise in response to multiple processes. Discriminating among alternative patterning mechanisms, particularly where experimental manipulations are untenable, requires process-based models. Previous modeling studies have attributed patterning in the Everglades (Florida, USA) to sediment redistribution and anisotropic soil hydraulic properties. In this work, we tested an alternate theory, the self-organizing-canal (SOC) hypothesis, by developing a cellular automata model that simulates pattern evolution via local positive feedbacks (i.e., facilitation) coupled with a global negative feedback based on hydrology. The model is forced by global hydroperiod that drives stochastic transitions between two patch types: ridge (higher elevation) and slough (lower elevation). We evaluated model performance using multiple criteria based on six statistical and geostatistical properties observed in reference portions of the Everglades landscape: patch density, patch anisotropy, semivariogram ranges, power-law scaling of ridge areas, perimeter area fractal dimension, and characteristic pattern wavelength. Model results showed strong statistical agreement with reference landscapes, but only when anisotropically acting local facilitation was coupled with hydrologic global feedback, for which several plausible mechanisms exist. Critically, the model correctly generated fractal landscapes that had no characteristic pattern wavelength, supporting the invocation of global rather than scale-specific negative feedbacks.
NASA Astrophysics Data System (ADS)
Acharya, S.; Kaplan, D. A.; Casey, S.; Cohen, M. J.; Jawitz, J. W.
2015-01-01
Self-organized landscape patterning can arise in response to multiple processes. Discriminating among alternative patterning mechanisms, particularly where experimental manipulations are untenable, requires process-based models. Previous modeling studies have attributed patterning in the Everglades (Florida, USA) to sediment redistribution and anisotropic soil hydraulic properties. In this work, we tested an alternate theory, the self-organizing canal (SOC) hypothesis, by developing a cellular automata model that simulates pattern evolution via local positive feedbacks (i.e., facilitation) coupled with a global negative feedback based on hydrology. The model is forced by global hydroperiod that drives stochastic transitions between two patch types: ridge (higher elevation) and slough (lower elevation). We evaluated model performance using multiple criteria based on six statistical and geostatistical properties observed in reference portions of the Everglades landscape: patch density, patch anisotropy, semivariogram ranges, power-law scaling of ridge areas, perimeter area fractal dimension, and characteristic pattern wavelength. Model results showed strong statistical agreement with reference landscapes, but only when anisotropically acting local facilitation was coupled with hydrologic global feedback, for which several plausible mechanisms exist. Critically, the model correctly generated fractal landscapes that had no characteristic pattern wavelength, supporting the invocation of global rather than scale-specific negative feedbacks.
Samanta, Brajogopal; Bhadury, Punyasloke
2016-01-01
Marine chromophytes are taxonomically diverse group of algae and contribute approximately half of the total oceanic primary production. To understand the global patterns of functional diversity of chromophytic phytoplankton, robust bioinformatics and statistical analyses including deep phylogeny based on 2476 form ID rbcL gene sequences representing seven ecologically significant oceanographic ecoregions were undertaken. In addition, 12 form ID rbcL clone libraries were generated and analyzed (148 sequences) from Sundarbans Biosphere Reserve representing the world’s largest mangrove ecosystem as part of this study. Global phylogenetic analyses recovered 11 major clades of chromophytic phytoplankton in varying proportions with several novel rbcL sequences in each of the seven targeted ecoregions. Majority of OTUs was found to be exclusive to each ecoregion, whereas some were shared by two or more ecoregions based on beta-diversity analysis. Present phylogenetic and bioinformatics analyses provide a strong statistical support for the hypothesis that different oceanographic regimes harbor distinct and coherent groups of chromophytic phytoplankton. It has been also shown as part of this study that varying natural selection pressure on form ID rbcL gene under different environmental conditions could lead to functional differences and overall fitness of chromophytic phytoplankton populations. PMID:26861415
Bayes factor and posterior probability: Complementary statistical evidence to p-value.
Lin, Ruitao; Yin, Guosheng
2015-09-01
As a convention, a p-value is often computed in hypothesis testing and compared with the nominal level of 0.05 to determine whether to reject the null hypothesis. Although the smaller the p-value, the more significant the statistical test, it is difficult to perceive the p-value in a probability scale and quantify it as the strength of the data against the null hypothesis. In contrast, the Bayesian posterior probability of the null hypothesis has an explicit interpretation of how strong the data support the null. We make a comparison of the p-value and the posterior probability by considering a recent clinical trial. The results show that even when we reject the null hypothesis, there is still a substantial probability (around 20%) that the null is true. Not only should we examine whether the data would have rarely occurred under the null hypothesis, but we also need to know whether the data would be rare under the alternative. As a result, the p-value only provides one side of the information, for which the Bayes factor and posterior probability may offer complementary evidence. Copyright © 2015 Elsevier Inc. All rights reserved.
Kakouros, Sofoklis; Räsänen, Okko
2016-09-01
Numerous studies have examined the acoustic correlates of sentential stress and its underlying linguistic functionality. However, the mechanism that connects stress cues to the listener's attentional processing has remained unclear. Also, the learnability versus innateness of stress perception has not been widely discussed. In this work, we introduce a novel perspective to the study of sentential stress and put forward the hypothesis that perceived sentence stress in speech is related to the unpredictability of prosodic features, thereby capturing the attention of the listener. As predictability is based on the statistical structure of the speech input, the hypothesis also suggests that stress perception is a result of general statistical learning mechanisms. To study this idea, computational simulations are performed where temporal prosodic trajectories are modeled with an n-gram model. Probabilities of the feature trajectories are subsequently evaluated on a set of novel utterances and compared to human perception of stress. The results show that the low-probability regions of F0 and energy trajectories are strongly correlated with stress perception, giving support to the idea that attention and unpredictability of sensory stimulus are mutually connected. Copyright © 2015 Cognitive Science Society, Inc.
Supporting Regularized Logistic Regression Privately and Efficiently.
Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei
2016-01-01
As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc.
An online sleep apnea detection method based on recurrence quantification analysis.
Nguyen, Hoa Dinh; Wilkins, Brek A; Cheng, Qi; Benjamin, Bruce Allen
2014-07-01
This paper introduces an online sleep apnea detection method based on heart rate complexity as measured by recurrence quantification analysis (RQA) statistics of heart rate variability (HRV) data. RQA statistics can capture nonlinear dynamics of a complex cardiorespiratory system during obstructive sleep apnea. In order to obtain a more robust measurement of the nonstationarity of the cardiorespiratory system, we use different fixed amount of neighbor thresholdings for recurrence plot calculation. We integrate a feature selection algorithm based on conditional mutual information to select the most informative RQA features for classification, and hence, to speed up the real-time classification process without degrading the performance of the system. Two types of binary classifiers, i.e., support vector machine and neural network, are used to differentiate apnea from normal sleep. A soft decision fusion rule is developed to combine the results of these classifiers in order to improve the classification performance of the whole system. Experimental results show that our proposed method achieves better classification results compared with the previous recurrence analysis-based approach. We also show that our method is flexible and a strong candidate for a real efficient sleep apnea detection system.
Supporting Regularized Logistic Regression Privately and Efficiently
Li, Wenfa; Liu, Hongzhe; Yang, Peng; Xie, Wei
2016-01-01
As one of the most popular statistical and machine learning models, logistic regression with regularization has found wide adoption in biomedicine, social sciences, information technology, and so on. These domains often involve data of human subjects that are contingent upon strict privacy regulations. Concerns over data privacy make it increasingly difficult to coordinate and conduct large-scale collaborative studies, which typically rely on cross-institution data sharing and joint analysis. Our work here focuses on safeguarding regularized logistic regression, a widely-used statistical model while at the same time has not been investigated from a data security and privacy perspective. We consider a common use scenario of multi-institution collaborative studies, such as in the form of research consortia or networks as widely seen in genetics, epidemiology, social sciences, etc. To make our privacy-enhancing solution practical, we demonstrate a non-conventional and computationally efficient method leveraging distributing computing and strong cryptography to provide comprehensive protection over individual-level and summary data. Extensive empirical evaluations on several studies validate the privacy guarantee, efficiency and scalability of our proposal. We also discuss the practical implications of our solution for large-scale studies and applications from various disciplines, including genetic and biomedical studies, smart grid, network analysis, etc. PMID:27271738
NASA Astrophysics Data System (ADS)
Troitskaya, Yuliya; Kandaurov, Alexander; Ermakova, Olga; Kozlov, Dmitry; Sergeev, Daniil; Zilitinkevich, Sergej
2016-04-01
Sea sprays is a typical element of the marine atmospheric boundary layer (MABL) of large importance for marine meteorology, atmospheric chemistry and climate studies. They are considered as a crucial factor in the development of hurricanes and severe extratropical storms, since they can significantly enhance exchange of mass, heat and momentum between the ocean and the atmosphere. This exchange is directly provided by spume droplets with the sizes from 10 microns to a few millimeters mechanically torn off the crests of a breaking waves and fall down to the ocean due to gravity. The fluxes associated with the spray are determined by the rate of droplet production at the surface quantified by the sea spray generation function (SSGF), defined as the number of spray particles of radius r produced from the unit area of water surface in unit time. However, the mechanism of spume droplets' formation is unknown and empirical estimates of SSGF varied over six orders of magnitude; therefore, the production rate of large sea spray droplets is not adequately described and there are significant uncertainties in estimations of exchange processes in hurricanes. Experimental core of our work comprise laboratory experiments employing high-speed video-filming, which have made it possible to disclose how water surface looks like at extremely strong winds and how exactly droplets are torn off wave crests. We classified events responsible for spume droplet, including bursting of submerged bubbles, generation and breakup of "projections" or liquid filaments (Koa, 1981) and "bag breakup", namely, inflating and consequent blowing of short-lived, sail-like pieces of the water-surface film, "bags". The process is similar to "bag-breakup" mode of fragmentation of liquid droplets and jets in gaseous flows. Basing on statistical analysis of results of these experiments we show that the main mechanism of spray-generation is attributed to "bag-breakup mechanism On the base of general principles of statistical physics (model of a canonical ensemble) we developed statistics of the "bag-breakup" events and constructed sea spray generation function (SSGF) for the mechanism of "bag-breakup". The "bag breakup" SSGF is shown to be in reasonable agreement in magnitude with SSFGs considered as the most reliable source function for spume droplets. The new SSGF is employed for estimate of the new"bag-breakup" mechanism to momentum and energy exchange in marine atmospheric boundary layer at hurricane conditions. This work was supported by the Russian Foundation of Basic Research (14-05-91767, 13-05-12093, 16-05-00839, 14-05-91767, 16-55-52025) and experiment and equipment was supported by Russian Science Foundation (Agreements 14-17-00667 and 15-17-20009 respectively), Yu.Troitskaya, A.Kandaurov and D.Sergeev were partially supported by FP7 collaborative Project No. 612610.
Local support against gravity in magnetoturbulent fluids
NASA Astrophysics Data System (ADS)
Schmidt, W.; Collins, D. C.; Kritsuk, A. G.
2013-06-01
Comparisons of the integrated thermal pressure support of gas against its gravitational potential energy lead to critical mass scales for gravitational instability such as the Jeans and the Bonnor-Ebert masses, which play an important role in the analysis of many physical systems, including the heuristics of numerical simulations. In a strict theoretical sense, however, neither the Jeans nor the Bonnor-Ebert mass is meaningful when applied locally to substructure in a self-gravitating turbulent medium. For this reason, we investigate the local support by thermal pressure, turbulence and magnetic fields against gravitational compression through an approach that is independent of these concepts. At the centre of our approach is the dynamical equation for the divergence of the velocity field. We carry out a statistical analysis of the source terms of the local compression rate (the negative time derivative of the divergence) for simulations of forced self-gravitating turbulence in periodic boxes with zero, weak and moderately strong mean magnetic fields (measured by the averages of the magnetic and thermal pressures). We also consider the amplification of the magnetic field energy by shear and by compression. Thereby, we are able to demonstrate that the support against gravity is dominated by thermal pressure fluctuations, although magnetic pressure also yields a significant contribution. The net effect of turbulence in the highly supersonic regime, however, is to enhance compression rather than supporting overdense gas even if the vorticity is very high. This is incommensurate with the support of the highly dynamical substructures in magnetoturbulent fluids being determined by local virial equilibria of volume energies without surface stresses.
Jackknife Variance Estimator for Two Sample Linear Rank Statistics
1988-11-01
Accesion For - - ,NTIS GPA&I "TIC TAB Unann c, nc .. [d Keywords: strong consistency; linear rank test’ influence function . i , at L By S- )Distribut...reverse if necessary and identify by block number) FIELD IGROUP SUB-GROUP Strong consistency; linear rank test; influence function . 19. ABSTRACT
Lagrangian statistics of mesoscale turbulence in a natural environment: The Agulhas return current.
Carbone, Francesco; Gencarelli, Christian N; Hedgecock, Ian M
2016-12-01
The properties of mesoscale geophysical turbulence in an oceanic environment have been investigated through the Lagrangian statistics of sea surface temperature measured by a drifting buoy within the Agulhas return current, where strong temperature mixing produces locally sharp temperature gradients. By disentangling the large-scale forcing which affects the small-scale statistics, we found that the statistical properties of intermittency are identical to those obtained from the multifractal prediction in the Lagrangian frame for the velocity trajectory. The results suggest a possible universality of turbulence scaling.
NASA Astrophysics Data System (ADS)
Dralle, D.; Karst, N.; Thompson, S. E.
2015-12-01
Multiple competing theories suggest that power law behavior governs the observed first-order dynamics of streamflow recessions - the important process by which catchments dry-out via the stream network, altering the availability of surface water resources and in-stream habitat. Frequently modeled as: dq/dt = -aqb, recessions typically exhibit a high degree of variability, even within a single catchment, as revealed by significant shifts in the values of "a" and "b" across recession events. One potential source of this variability lies in underlying, hard-to-observe fluctuations in how catchment water storage is partitioned amongst distinct storage elements, each having different discharge behaviors. Testing this and competing hypotheses with widely available streamflow timeseries, however, has been hindered by a power law scaling artifact that obscures meaningful covariation between the recession parameters, "a" and "b". Here we briefly outline a technique that removes this artifact, revealing intriguing new patterns in the joint distribution of recession parameters. Using long-term flow data from catchments in Northern California, we explore temporal variations, and find that the "a" parameter varies strongly with catchment wetness. Then we explore how the "b" parameter changes with "a", and find that measures of its variation are maximized at intermediate "a" values. We propose an interpretation of this pattern based on statistical mechanics, meaning "b" can be viewed as an indicator of the catchment "microstate" - i.e. the partitioning of storage - and "a" as a measure of the catchment macrostate (i.e. the total storage). In statistical mechanics, entropy (i.e. microstate variance, that is the variance of "b") is maximized for intermediate values of extensive variables (i.e. wetness, "a"), as observed in the recession data. This interpretation of "a" and "b" was supported by model runs using a multiple-reservoir catchment toy model, and lends support to the hypothesis that power law streamflow recession dynamics, and their variations, have their origin in the multiple modalities of storage partitioning.
A GROWTH-RATE INDICATOR FOR COMPTON-THICK ACTIVE GALACTIC NUCLEI
DOE Office of Scientific and Technical Information (OSTI.GOV)
Brightman, M.; Baloković, M.; Harrison, F. A.
2016-07-20
Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGNs) is difficult to measure. A statistically significant correlation between the Eddington ratio, λ {sub Edd}, and the X-ray power-law index, Γ, observed in unobscured AGNs offers an estimate of their growth rate from X-ray spectroscopy (albeit with large scatter). However, since X-rays undergo reprocessing by Compton scattering and photoelectric absorption when the line of sight to the central engine is heavily obscured, the recovery of the intrinsic Γ is challenging. Here we study a sample of local, predominantly CT megamaser AGNs, where themore » black hole mass, and thus Eddington luminosity, are well known. We compile results of the X-ray spectral fitting of these sources with sensitive high-energy ( E > 10 keV) NuSTAR data, where X-ray torus models, which take into account the reprocessing effects have been used to recover the intrinsic Γ values and X-ray luminosities, L {sub X}. With a simple bolometric correction to L {sub X} to calculate λ {sub Edd}, we find a statistically significant correlation between Γ and λ {sub Edd} ( p = 0.007). A linear fit to the data yields Γ = (0.41 ± 0.18)log{sub 10} λ {sub Edd} + (2.38 ± 0.20), which is statistically consistent with results for unobscured AGNs. This result implies that torus modeling successfully recovers the intrinsic AGN parameters. Since the megamasers have low-mass black holes ( M {sub BH} ≈ 10{sup 6}–10{sup 7} M {sub ⊙}) and are highly inclined, our results extend the Γ– λ {sub Edd} relationship to lower masses and argue against strong orientation effects in the corona, in support of AGN unification. Finally this result supports the use of Γ as a growth-rate indicator for accreting black holes, even for CT AGNs.« less
Mercadante, Sebastiano; Adile, Claudio; Ferrera, Patrizia; Casuccio, Alessandra
2017-07-01
The aim of this prospective study was to determine the characteristics and symptom burden of advanced cancer patients with alcoholism problems and smoking, who were referred to an acute palliative/supportive care unit (ASPCU) of a comprehensive cancer center. Patients' characteristics, indications for admission, kind of admission, awareness of prognosis, and anticancer treatments were recorded. The Edmonton Symptom Assessment Scale (ESAS) was used to assess physical and psychological symptoms, and the CAGE questionnaire for the diagnosis of alcoholism. Patients were also divided in three groups: persistent smokers (PS), former smokers (FS), and non-smokers (NS). The Memorial Delirium Assessment Scale (MDAS) was used to assess the cognitive status of patients. Analgesic drugs and their doses at admission and discharge were recorded, as well opioid escalation index during hospital stay. Three hundred fourteen consecutive cancer patients were surveyed. Forty-seven (14.9%), 143 (45.5%), and 124 (39.5%) subjects were PS-patients, FS-patients, and NS-patients, respectively. Sixteen patients were CAGE-positive. Females were more frequently NS, while males were more frequently FS (p = 0.0005). Statistical differences were also observed in disease awareness among the categories of smoking (p = 0.048). No statistical differences were found in ESAS items, except for drowsiness at T0 in NS-patients. Differences were found in OME and OEI, although the large variability of data did not determined a statistical difference. Higher values of nausea (at T0, p = 0.0005), dyspnea (at T0 and TX, p = 0.08 and 0.023, respectively), and well-being (at TX p = 0.003) were reported in CAGE-positive patients. No correlation was found between CAGE-positive patients and smokers. Although smoking and alcoholism have obvious implications in advanced cancer patients, data remain controversial, as present data did provide limited data to confirm risk factors for advanced cancer patients. Clinical response was not strongly influenced by these risk factors.
Uzoka, Faith-Michael Emeka; Obot, Okure; Barker, Ken; Osuji, J
2011-07-01
The task of medical diagnosis is a complex one, considering the level vagueness and uncertainty management, especially when the disease has multiple symptoms. A number of researchers have utilized the fuzzy-analytic hierarchy process (fuzzy-AHP) methodology in handling imprecise data in medical diagnosis and therapy. The fuzzy logic is able to handle vagueness and unstructuredness in decision making, while the AHP has the ability to carry out pairwise comparison of decision elements in order to determine their importance in the decision process. This study attempts to do a case comparison of the fuzzy and AHP methods in the development of medical diagnosis system, which involves basic symptoms elicitation and analysis. The results of the study indicate a non-statistically significant relative superiority of the fuzzy technology over the AHP technology. Data collected from 30 malaria patients were used to diagnose using AHP and fuzzy logic independent of one another. The results were compared and found to covary strongly. It was also discovered from the results of fuzzy logic diagnosis covary a little bit more strongly to the conventional diagnosis results than that of AHP. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Winkler, Isaac S.; Mitter, Charles; Scheffer, Sonja J.
2009-01-01
A central but little-tested prediction of “escape and radiation” coevolution is that colonization of novel, chemically defended host plant clades accelerates insect herbivore diversification. That theory, in turn, exemplifies one side of a broader debate about the relative influence on clade dynamics of intrinsic (biotic) vs. extrinsic (physical-environmental) forces. Here, we use a fossil-calibrated molecular chronogram to compare the effects of a major biotic factor (repeated shift to a chemically divergent host plant clade) and a major abiotic factor (global climate change) on the macroevolutionary dynamics of a large Cenozoic radiation of phytophagous insects, the leaf-mining fly genus Phytomyza (Diptera: Agromyzidae). We find one of the first statistically supported examples of consistently elevated net diversification accompanying shift to new plant clades. In contrast, we detect no significant direct effect on diversification of major global climate events in the early and late Oligocene. The broader paleoclimatic context strongly suggests, however, that climate change has at times had a strong indirect influence through its effect on the biotic environment. Repeated rapid Miocene radiation of these flies on temperate herbaceous asterids closely corresponds to the dramatic, climate-driven expansion of seasonal, open habitats. PMID:19805134
Tobacco sales in pharmacies: time to quit
Hudmon, K Suchanek; Fenlon, C M; Corelli, R L; Prokhorov, A V; Schroeder, S A
2006-01-01
Objective To assess the pharmacy profession's perceptions of tobacco sales in US pharmacies and explore whether a policy prohibiting sales of tobacco in pharmacies would alter adult consumer shopping behaviour. Subjects and design In California, surveys were administered to 1168 licensed pharmacists and 1518 pharmacy students, and telephone interviews were conducted with 988 adult consumers. Results Most (58.1%) licensed pharmacists were strongly against sales of tobacco in pharmacies, 23.6% were against it, 16.7% were neutral, 1.2% were in favour of it, and 0.4% were strongly in favour of it. Pharmacists who were current tobacco users were more likely to be in favour of tobacco sales in pharmacies than were pharmacists who were current non‐users (p < 0.005). Similar statistics were observed for pharmacy students. Most consumers (72.3%) disagreed with the statement, “I am in favour of tobacco products being sold in drugstores”; 82.6% stated that if the drugstore where they most commonly shopped were to stop selling tobacco products, they would shop there just as often, 14.2% would shop there more often, and 3.2% would shop there less often. Conclusion Little professional or public support exists for tobacco sales in pharmacies. PMID:16436403
Tobacco sales in pharmacies: time to quit.
Hudmon, K Suchanek; Fenlon, C M; Corelli, R L; Prokhorov, A V; Schroeder, S A
2006-02-01
To assess the pharmacy profession's perceptions of tobacco sales in US pharmacies and explore whether a policy prohibiting sales of tobacco in pharmacies would alter adult consumer shopping behaviour. In California, surveys were administered to 1168 licensed pharmacists and 1518 pharmacy students, and telephone interviews were conducted with 988 adult consumers. Most (58.1%) licensed pharmacists were strongly against sales of tobacco in pharmacies, 23.6% were against it, 16.7% were neutral, 1.2% were in favour of it, and 0.4% were strongly in favour of it. Pharmacists who were current tobacco users were more likely to be in favour of tobacco sales in pharmacies than were pharmacists who were current non-users (p < 0.005). Similar statistics were observed for pharmacy students. Most consumers (72.3%) disagreed with the statement, "I am in favour of tobacco products being sold in drugstores"; 82.6% stated that if the drugstore where they most commonly shopped were to stop selling tobacco products, they would shop there just as often, 14.2% would shop there more often, and 3.2% would shop there less often. Little professional or public support exists for tobacco sales in pharmacies.
Sémon, Marie; Mouchiroud, Dominique; Duret, Laurent
2005-02-01
Mammalian chromosomes are characterized by large-scale variations of DNA base composition (the so-called isochores). In contradiction with previous studies, Lercher et al. (Hum. Mol. Genet., 12, 2411, 2003) recently reported a strong correlation between gene expression breadth and GC-content, suggesting that there might be a selective pressure favoring the concentration of housekeeping genes in GC-rich isochores. We reassessed this issue by examining in human and mouse the correlation between gene expression and GC-content, using different measures of gene expression (EST, SAGE and microarray) and different measures of GC-content. We show that correlations between GC-content and expression are very weak, and may vary according to the method used to measure expression. Such weak correlations have a very low predictive value. The strong correlations reported by Lercher et al. (2003) are because of the fact that they measured variables over neighboring genes windows. We show here that using gene windows artificially enhances the correlation. The assertion that the expression of a given gene depends on the GC-content of the region where it is located is therefore not supported by the data.
Nitrous oxide as a function of oxygen and archaeal gene abundance in the North Pacific
NASA Astrophysics Data System (ADS)
Trimmer, Mark; Chronopoulou, Panagiota-Myrsini; Maanoja, Susanna T.; Upstill-Goddard, Robert C.; Kitidis, Vassilis; Purdy, Kevin J.
2016-12-01
Oceanic oxygen minimum zones are strong sources of the potent greenhouse gas N2O but its microbial source is unclear. We characterized an exponential response in N2O production to decreasing oxygen between 1 and 30 μmol O2 l-1 within and below the oxycline using 15NO2-, a relationship that held along a 550 km offshore transect in the North Pacific. Differences in the overall magnitude of N2O production were accounted for by archaeal functional gene abundance. A one-dimensional (1D) model, parameterized with our experimentally derived exponential terms, accurately reproduces N2O profiles in the top 350 m of water column and, together with a strong 45N2O signature indicated neither canonical nor nitrifier-denitrification production while statistical modelling supported production by archaea, possibly via hybrid N2O formation. Further, with just archaeal N2O production, we could balance high-resolution estimates of sea-to-air N2O exchange. Hence, a significant source of N2O, previously described as leakage from bacterial ammonium oxidation, is better described by low-oxygen archaeal production at the oxygen minimum zone's margins.
Garcia, Andres; Wang, Jing; Windus, Theresa L.; ...
2016-05-20
Statistical mechanical modeling is developed to describe a catalytic conversion reaction A → B c or B t with concentration-dependent selectivity of the products, B c or B t, where reaction occurs inside catalytic particles traversed by narrow linear nanopores. The associated restricted diffusive transport, which in the extreme case is described by single-file diffusion, naturally induces strong concentration gradients. Hence, by comparing kinetic Monte Carlo simulation results with analytic treatments, selectivity is shown to be impacted by strong spatial correlations induced by restricted diffusivity in the presence of reaction and also by a subtle clustering of reactants, A.
Tomayko, Emily J; Prince, Ronald J; Cronin, Kate A; Parker, Tassy; Kim, Kyungmann; Grant, Vernon M; Sheche, Judith N; Adams, Alexandra K
2017-04-01
Background/Aims Few obesity prevention trials have focused on young children and their families in the home environment, particularly in underserved communities. Healthy Children, Strong Families 2 is a randomized controlled trial of a healthy lifestyle intervention for American Indian children and their families, a group at very high risk of obesity. The study design resulted from our long-standing engagement with American Indian communities, and few collaborations of this type resulting in the development and implementation of a randomized clinical trial have been described. Methods Healthy Children, Strong Families 2 is a lifestyle intervention targeting increased fruit and vegetable intake, decreased sugar intake, increased physical activity, decreased TV/screen time, and two less-studied risk factors: stress and sleep. Families with young children from five American Indian communities nationwide were randomly assigned to a healthy lifestyle intervention ( Wellness Journey) augmented with social support (Facebook and text messaging) or a child safety control group ( Safety Journey) for 1 year. After Year 1, families in the Safety Journey receive the Wellness Journey, and families in the Wellness Journey start the Safety Journey with continued wellness-focused social support based on communities' request that all families receive the intervention. Primary (adult body mass index and child body mass index z-score) and secondary (health behaviors) outcomes are assessed after Year 1 with additional analyses planned after Year 2. Results To date, 450 adult/child dyads have been enrolled (100% target enrollment). Statistical analyses await trial completion in 2017. Lessons learned Conducting a community-partnered randomized controlled trial requires significant formative work, relationship building, and ongoing flexibility. At the communities' request, the study involved minimal exclusion criteria, focused on wellness rather than obesity, and included an active control group and a design allowing all families to receive the intervention. This collective effort took additional time but was critical to secure community engagement. Hiring and retaining qualified local site coordinators was a challenge but was strongly related to successful recruitment and retention of study families. Local infrastructure has also been critical to project success. Other challenges included geographic dispersion of study communities and providing appropriate incentives to retain families in a 2-year study. Conclusion This multisite intervention addresses key gaps regarding family/home-based approaches for obesity prevention in American Indian communities. Healthy Children, Strong Families 2's innovative aspects include substantial community input, inclusion of both traditional (diet/activity) and less-studied obesity risk factors (stress/sleep), measurement of both adult and child outcomes, social networking support for geographically dispersed households, and a community selected active control group. Our data will address a literature gap regarding multiple risk factors and their relationship to health outcomes in American Indian families.
Harper, Sarah K; Webb, Thomas L; Rayner, Kelly
2013-05-01
A number of studies have used mindfulness-based interventions to influence the behavior of people with intellectual disabilities, to improve their quality of life, and to reduce challenging behavior. The present review critically evaluates 18 studies and assesses the clinical and academic impact of their findings. Strengths identified included replicable methodological approaches, use of multiple baseline designs, strong construct and criterion validity, and consideration of the mechanisms by which mindfulness influences behavior change. Limitations included a lack of randomized controlled trials, inclusion of qualitative data without structured analysis, limited use of statistical analyses, and problems with sampling leading to difficulties generalizing findings. There was also a paucity of research investigating the impact of "Dialectical Behavior Therapy" and "Acceptance and Commitment Therapy" and the role of mindfulness within these approaches. Further research is warranted in this regard.
NASA Astrophysics Data System (ADS)
Larsen, A. C.; Guttormsen, M.; Blasi, N.; Bracco, A.; Camera, F.; Crespo Campo, L.; Eriksen, T. K.; Görgen, A.; Hagen, T. W.; Ingeberg, V. W.; Kheswa, B. V.; Leoni, S.; E Midtbø, J.; Million, B.; Nyhus, H. T.; Renstrøm, T.; Rose, S. J.; E Ruud, I.; Siem, S.; Tornyi, T. G.; Tveten, G. M.; Voinov, A. V.; Wiedeking, M.; Zeiser, F.
2017-06-01
Nuclear level densities and γ-ray strength functions of 56,57Fe have been extracted from proton-γ coincidences. A low-energy enhancement in the γ-ray strength functions up to a factor of 30 over common theoretical E1 models is confirmed. Angular distributions of the low-energy enhancement in 57Fe indicate its dipole nature, in agreement with findings for 56Fe. The high statistics and the excellent energy resolution of the large-volume LaBr3(Ce) detectors allowed for a thorough analysis of γ strength as function of excitation energy. Taking into account the presence of strong Porter-Thomas fluctuations, there is no indication of any significant excitation energy dependence in the γ-ray strength function, in support of the generalized Brink-Axel hypothesis.
An update on the correlation between the cosmic radiation intensity and the geomagnetic AA index
NASA Technical Reports Server (NTRS)
Shea, M. A.; Smart, D. F.
1985-01-01
A statistical study between the cosmic ray intensity, as observed by a neutron monitor, and of the geomagnetic aa index, as representative of perturbations in the plasma and interplanetary magnetic field in the heliosphere, has been updated to specifically exclude time periods around the reversal of the solar magnetic field. The results of this study show a strong negative correlation for the period 1960 through 1968 with a correlation coefficient of approximately -0.86. However, there is essentially no correlation between the cosmic ray intensity and the aa index for the period 1972-1979 (i.e. correlation coefficient less than 0.16). These results would appear to support the theory of preferential particle propagation into the heliosphere vis the ecliptic during the period 1960-1968 and via the solar polar regions during 1972-1979.
Cigarette smoking and suicide attempts in psychiatric outpatients in Hungary.
Rihmer, Zoltán; Döme, Péter; Gonda, Xénia; Kiss, Huba G; Kovács, Dénes; Seregi, Krisztina; Teleki, Zsófia
2007-06-01
Epidemiological and clinical studies have found a significant association between smoking and suicidal behaviour. 334 outpatients with DSM-IV diagnosis of unipolar major depression, bipolar (I+II) disorder, schizophrenia, schizoaffective disorder and pure panic disorder were interviewed regarding to their smoking habits and previous suicide attempts. With the exception of panic disorder patients, the rate of prior suicide attempt(s) was much higher among current and lifetime smokers than among never smokers in all diagnostic groups, but the difference was statistically significant only for lifetime smoker unipolar depressives and for current and lifetime smoker schizophrenics. Age, social class and alcohol/caffeine consumption was not controlled and dependent vs nondependent smokers were not distinguished. The findings support previous results on the strong relationship between smoking and suicidal behaviour in psychiatric (particularly major depressive and schizophrenic) patients.
Assessing the status of airline safety culture and its relationship to key employee attitudes
NASA Astrophysics Data System (ADS)
Owen, Edward L.
The need to identify the factors that influence the overall safety environment and compliance with safety procedures within airline operations is substantial. This study examines the relationships between job satisfaction, the overall perception of the safety culture, and compliance with safety rules and regulations of airline employees working in flight operations. A survey questionnaire administered via the internet gathered responses which were converted to numerical values for quantitative analysis. The results were grouped to provide indications of overall average levels in each of the three categories, satisfaction, perceptions, and compliance. Correlations between data in the three sets were tested for statistical significance using two-sample t-tests assuming equal variances. Strong statistical significance was found between job satisfaction and compliance with safety rules and between perceptions of the safety environment and safety compliance. The relationship between job satisfaction and safety perceptions did not show strong statistical significance.
NASA Astrophysics Data System (ADS)
Ghezelbash, Reza; Maghsoudi, Abbas
2018-05-01
The delineation of populations of stream sediment geochemical data is a crucial task in regional exploration surveys. In this contribution, uni-element stream sediment geochemical data of Cu, Au, Mo, and Bi have been subjected to two reliable anomaly-background separation methods, namely, the concentration-area (C-A) fractal and the U-spatial statistics methods to separate geochemical anomalies related to porphyry-type Cu mineralization in northwest Iran. The quantitative comparison of the delineated geochemical populations using the modified success-rate curves revealed the superiority of the U-spatial statistics method over the fractal model. Moreover, geochemical maps of investigated elements revealed strongly positive correlations between strong anomalies and Oligocene-Miocene intrusions in the study area. Therefore, follow-up exploration programs should focus on these areas.
Cultural Differences in Support Provision: The Importance of Relationship Quality.
Chen, Jacqueline M; Kim, Heejung S; Sherman, David K; Hashimoto, Takeshi
2015-11-01
Emotional expression is highly valued in individualistic cultures, whereas emotional restraint is prioritized in collectivistic cultures. We hypothesized that high-quality relationships in these cultures would exhibit the forms of support provision congruent with their respective expectations. Study 1 examined support transactions among friends in response to a laboratory stressor and found that objectively judged relationship quality (RQ) more strongly positively predicted emotion-focused support provision behaviors by European Americans than by Asian Americans. Study 2, a questionnaire study, found that self-reported RQ predicted emotion-focused support provision more strongly among European Americans than among Japanese. Study 3 investigated more indirect forms of support and found that RQ more strongly predicted worrying about and monitoring close others enduring stressors and spending time with them without talking about the stressor among Asian Americans compared with European Americans. These findings suggest that RQ is expressed in terms of support provision in culturally normative ways. © 2015 by the Society for Personality and Social Psychology, Inc.
NASA Astrophysics Data System (ADS)
Jiao, Yi; Duan, Zhe
2017-01-01
In a diffraction-limited storage ring, half integer resonances can have strong effects on the beam dynamics, associated with the large detuning terms from the strong focusing and strong sextupoles as required for an ultralow emittance. In this study, the limitation of half integer resonances on the available momentum acceptance (MA) was statistically analyzed based on one design of the High Energy Photon Source (HEPS). It was found that the probability of MA reduction due to crossing of half integer resonances is closely correlated with the level of beta beats at the nominal tunes, but independent of the error sources. The analysis indicated that for the presented HEPS lattice design, the rms amplitude of beta beats should be kept below 1.5% horizontally and 2.5% vertically to reach a small MA reduction probability of about 1%.
Jensen, Majken K; Bartz, Traci M; Djoussé, Luc; Kizer, Jorge R; Zieman, Susan J; Rimm, Eric B; Siscovick, David S; Psaty, Bruce M; Ix, Joachim H; Mukamal, Kenneth J
2013-10-01
Fetuin-A levels are associated with higher risk of type 2 diabetes, but it is unknown if the association is causal. We investigated common (>5%) genetic variants in the fetuin-A gene (AHSG) fetuin-A levels, fasting glucose, and risk of type 2 diabetes. Genetic variation, fetuin-A levels, and fasting glucose were assessed in 2,893 Caucasian and 542 African American community-living individuals 65 years of age or older in 1992-1993. Common AHSG variants (rs4917 and rs2248690) were strongly associated with fetuin-A concentrations (P<0.0001). In analyses of 259 incident cases of type 2 diabetes, the single nucleotide polymorphisms (SNPs) were not associated with diabetes risk during follow-up and similar null associations were observed when 579 prevalent cases were included. As expected, higher fetuin-A levels were associated with higher fasting glucose concentrations (1.9 mg/dL [95% CI, 1.2-2.7] higher per SD in Caucasians), but Mendelian randomization analyses using both SNPs as unbiased proxies for measured fetuin-A did not support an association between genetically predicted fetuin-A levels and fasting glucose (-0.3 mg/dL [95% CI, -1.9 to 1.3] lower per SD in Caucasians). The difference between the associations of fasting glucose with actual and genetically predicted fetuin-A level was statistically significant (P=0.001). Results among the smaller sample of African Americans trended in similar directions but were statistically insignificant. Common variants in the AHSG gene are strongly associated with plasma fetuin-A concentrations, but not with risk of type 2 diabetes or glucose concentrations, raising the possibility that the association between fetuin-A and type 2 diabetes may not be causal.
Water-sanitation-hygiene mapping: an improved approach for data collection at local level.
Giné-Garriga, Ricard; de Palencia, Alejandro Jiménez-Fernández; Pérez-Foguet, Agustí
2013-10-01
Strategic planning and appropriate development and management of water and sanitation services are strongly supported by accurate and accessible data. If adequately exploited, these data might assist water managers with performance monitoring, benchmarking comparisons, policy progress evaluation, resources allocation, and decision making. A variety of tools and techniques are in place to collect such information. However, some methodological weaknesses arise when developing an instrument for routine data collection, particularly at local level: i) comparability problems due to heterogeneity of indicators, ii) poor reliability of collected data, iii) inadequate combination of different information sources, and iv) statistical validity of produced estimates when disaggregated into small geographic subareas. This study proposes an improved approach for water, sanitation and hygiene (WASH) data collection at decentralised level in low income settings, as an attempt to overcome previous shortcomings. The ultimate aim is to provide local policymakers with strong evidences to inform their planning decisions. The survey design takes the Water Point Mapping (WPM) as a starting point to record all available water sources at a particular location. This information is then linked to data produced by a household survey. Different survey instruments are implemented to collect reliable data by employing a variety of techniques, such as structured questionnaires, direct observation and water quality testing. The collected data is finally validated through simple statistical analysis, which in turn produces valuable outputs that might feed into the decision-making process. In order to demonstrate the applicability of the method, outcomes produced from three different case studies (Homa Bay District-Kenya-; Kibondo District-Tanzania-; and Municipality of Manhiça-Mozambique-) are presented. Copyright © 2013 Elsevier B.V. All rights reserved.
Chlorine-36 data at Yucca Mountain: Statistical tests of conceptual models for unsaturated-zone flow
Campbell, K.; Wolfsberg, A.; Fabryka-Martin, J.; Sweetkind, D.
2003-01-01
An extensive set of chlorine-36 (36Cl) data has been collected in the Exploratory Studies Facility (ESF), an 8-km-long tunnel at Yucca Mountain, Nevada, for the purpose of developing and testing conceptual models of flow and transport in the unsaturated zone (UZ) at this site. At several locations, the measured values of 36Cl/Cl ratios for salts leached from rock samples are high enough to provide strong evidence that at least a small component of bomb-pulse 36Cl, fallout from atmospheric testing of nuclear devices in the 1950s and 1960s, was measured, implying that some fraction of the water traveled from the ground surface through 200-300 m of unsaturated rock to the level of the ESF during the last 50 years. These data are analyzed here using a formal statistical approach based on log-linear models to evaluate alternative conceptual models for the distribution of such fast flow paths. The most significant determinant of the presence of bomb-pulse 36Cl in a sample from the welded Topopah Spring unit (TSw) is the structural setting from which the sample was collected. Our analysis generally supports the conceptual model that a fault that cuts through the nonwelded Paintbrush tuff unit (PTn) that overlies the TSw is required in order for bomb-pulse 36Cl to be transmitted to the sample depth in less than 50 years. Away from PTn-cutting faults, the ages of water samples at the ESF appear to be a strong function of the thickness of the nonwelded tuff between the ground surface and the ESF, due to slow matrix flow in that unit. ?? 2002 Elsevier Science B.V. All rights reserved.
ERIC Educational Resources Information Center
Haas, Stephanie W.; Pattuelli, Maria Cristina; Brown, Ron T.
2003-01-01
Describes the Statistical Interactive Glossary (SIG), an enhanced glossary of statistical terms supported by the GovStat ontology of statistical concepts. Presents a conceptual framework whose components articulate different aspects of a term's basic explanation that can be manipulated to produce a variety of presentations. The overarching…
Ng, Charis W L; Tan, Woan Shin; Gunapal, Pradeep P G; Wong, Lai Yin; Heng, Bee Hoon
2014-12-01
Depression in the elderly is a major public health issue. Socioeconomic status (SES) and social support are strong risk factors for depression. This study aimed to investigate the influence of SES and social support in elderly depression, and the modifying effect of social support on the relationship between SES and depression. A community-based survey was conducted on residents≥60 years old. Depressive symptoms were determined with scores≥5 using the 15-item Geriatric Depression Scale (GDS). Multivariable logistic regression was performed to determine the odds ratio (OR) of depressive symptoms with respect to SES and social support, and interaction terms between the two variables. Of 2447 responses analysed, 188 (7.8%) respondents had depressive symptoms. Living in 2-room housing, living alone/with a domestic helper, infrequent leisure time with children/grandchildren or being childless, and feeling socially isolated were independently associated with depressive symptoms. Relative to residents living with spouse and children in 4-/5-room housing, the highest ORs for depressive symptoms were those living with spouse and children in 2-room (OR: 3.06, P<0.05), followed by living with children only in 3-room (OR: 2.98, P<0.05), and living alone/with a domestic helper in 4-/5-room (OR: 2.73, P<0.05). Living with spouse only appears to buffer against depressive symptoms across socioeconomic classes, although the effect was not statistically significant. Low social support and low SES significantly increased the odds of depressive symptoms. The moderating effect of social support on depression was however not consistent across SES groups. Specific interventions need to target different SES groups to better help older adults at risk of developing depression.
Mainous, Arch G; Porter, Maribeth; Agana, Denny Fe; Chessman, Alexander W
2018-05-01
The United States suffers from a low proportion of medical students pursuing family medicine (FM). Our objective was to examine institutional characteristics consistent with a focus on National Institutes of Health (NIH) research, institutional support for FM education, and the proportion of medical students choosing FM. The 2015 CERA Survey of Family Medicine Clerkship Directors was merged with institutional NIH funding data from 2014 and medical student specialty choice in 2015. Institutional educational support was operationalized as (1) clerkship director's perception of medical school environment toward FM, and (2) amount of negative comments about FM made by faculty in other departments. The outcome was the percentage of students selecting FM. Bivariate statistics were computed. As NIH funding increases, the proportion of students entering FM decreases (r=-.22). Institutions with higher NIH funding had lower clerkship director perceptions of medical school support toward FM (r=-.38). Among private institutions, the negative correlation between NIH funding and the proportion of students entering FM strengthens to r=-.48, P=.001. As perceptions of support for FM increase, the proportion of students entering FM increase (r=.47). Among private schools, perceptions of support toward family medicine was strongly positively correlated with the proportion of students entering FM (r=.72, P=.001). Higher institutional NIH funding is associated with less support for FM and lower proportions of students choosing FM. These issues appear to be even more influential in private medical schools. Understanding how to integrate the goals of NIH-level research and increasing primary care workforce so that both can be achieved is the next challenge.
ERIC Educational Resources Information Center
Aizikovitsh-Udi, Einav; Clarke, David; Kuntze, Sebastian
2014-01-01
Even though statistical thinking and critical thinking appear to have strong links from a theoretical point of view, empirical research into the intersections and potential interrelatedness of these aspects of competence is scarce. Our research suggests that thinking skills in both areas may be interdependent. Given this interconnection, it should…
A Model for Investigating Predictive Validity at Highly Selective Institutions.
ERIC Educational Resources Information Center
Gross, Alan L.; And Others
A statistical model for investigating predictive validity at highly selective institutions is described. When the selection ratio is small, one must typically deal with a data set containing relatively large amounts of missing data on both criterion and predictor variables. Standard statistical approaches are based on the strong assumption that…
ERIC Educational Resources Information Center
Komatsu, Hikaru; Rappleye, Jeremy
2017-01-01
Several recent, highly influential comparative studies have made strong statistical claims that improvements on global learning assessments such as PISA will lead to higher GDP growth rates. These claims have provided the primary source of legitimation for policy reforms championed by leading international organisations, most notably the World…
New Standards Require Teaching More Statistics: Are Preservice Secondary Mathematics Teachers Ready?
ERIC Educational Resources Information Center
Lovett, Jennifer N.; Lee, Hollylynne S.
2017-01-01
Mathematics teacher education programs often need to respond to changing expectations and standards for K-12 curriculum and accreditation. New standards for high school mathematics in the United States include a strong emphasis in statistics. This article reports results from a mixed methods cross-institutional study examining the preparedness of…
Bender, Jacqueline L; Wiljer, David; Matthew, Andrew; Canil, Christina M; Legere, Laura; Loblaw, Andrew; Jewett, Michael A S
2012-09-01
New models of survivorship care are required to address the needs of genitourinary (GU) cancer survivors. Current approaches do not effectively engage cancer survivors or advocacy groups. A group of clinicians in collaboration with the Canadian Urologic Association held a forum for GU cancer survivors, advocacy groups, and health professionals to explore ways to collaboratively enhance survivorship care. Participants attended a 2-day conference that included presentations, breakout groups, and a postconference survey. Discussions by breakout groups were recorded and analyzed alongside open-ended survey responses for common themes. Basic statistics were calculated. Conference participants (n = 42) included 18 cancer survivors/caregivers, 21 health professionals, and 3 researchers representing bladder, kidney, prostate, and testis cancer groups. Breakout group discussions and responses to the postconference survey (83.3 % response rate) showed strong support for greater collaboration among all parties. Strategies to facilitate collaboration reflected a need to: (1) raise awareness of the shared and unique needs of GU cancer survivors and the expertise of cancer advocacy groups, (2) facilitate communication and collaborative opportunities among clinicians/researchers and cancer survivors/advocacy groups, (3) facilitate collaborative programming and fund-raising among GU advocacy groups, and (4) synthesize and facilitate access to GU cancer survivorship resources and services. There is strong support for formal collaboration to enhance survivorship care among a critical mass of GU cancer survivors, advocacy groups, clinicians, and researchers. Responsibility for collaboration lies with all stakeholder groups. Strategies to foster such partnerships should employ integrated knowledge translation approaches that actively engage all parties throughout the entire research to practice process. Successful partnerships between cancer survivors, advocacy groups, clinicians, and researchers require familiarity with each other's expertise, along with sufficient resources and organizational structures. GU survivorship advocacy groups need to work more closely together to ensure a strong, unified voice when interacting with clinicians and researchers.
Machine learning Z2 quantum spin liquids with quasiparticle statistics
NASA Astrophysics Data System (ADS)
Zhang, Yi; Melko, Roger G.; Kim, Eun-Ah
2017-12-01
After decades of progress and effort, obtaining a phase diagram for a strongly correlated topological system still remains a challenge. Although in principle one could turn to Wilson loops and long-range entanglement, evaluating these nonlocal observables at many points in phase space can be prohibitively costly. With growing excitement over topological quantum computation comes the need for an efficient approach for obtaining topological phase diagrams. Here we turn to machine learning using quantum loop topography (QLT), a notion we have recently introduced. Specifically, we propose a construction of QLT that is sensitive to quasiparticle statistics. We then use mutual statistics between the spinons and visons to detect a Z2 quantum spin liquid in a multiparameter phase space. We successfully obtain the quantum phase boundary between the topological and trivial phases using a simple feed-forward neural network. Furthermore, we demonstrate advantages of our approach for the evaluation of phase diagrams relating to speed and storage. Such statistics-based machine learning of topological phases opens new efficient routes to studying topological phase diagrams in strongly correlated systems.
Verdi, Daunia; Pooley, Karen A.; Landi, Maria T.; Egan, Kathleen M.; Baird, Duncan M.; Prescott, Jennifer; De Vivo, Immaculata; Nitti, Donato
2012-01-01
Background Several recent studies have provided evidence that polymorphisms in the telomerase reverse transcriptase (TERT) gene sequence are associated with cancer development, but a comprehensive synopsis is not available. We conducted a systematic review and meta-analysis of the available molecular epidemiology data regarding the association between TERT locus polymorphisms and predisposition to cancer. Methods A systematic review of the English literature was conducted by searching PubMed, Embase, Cancerlit, Google Scholar, and ISI Web of Knowledge databases for studies on associations between TERT locus polymorphisms and cancer risk. Random-effects meta-analysis was performed to pool per-allele odds ratios for TERT locus polymorphisms and risk of cancer, and between-study heterogeneity and potential bias sources (eg, publication and chasing bias) were assessed. Because the TERT locus includes the cleft lip and palate transmembrane 1-like (CLPTM1L) gene, which is in linkage disequilibrium with TERT, CLPTM1L polymorphisms were also analyzed. Cumulative evidence for polymorphisms with statistically significant associations was graded as “strong,” “moderate,” and “weak” according to the Venice criteria. The joint population attributable risk was calculated for polymorphisms with strong evidence of association. Results Eighty-five studies enrolling 490 901 subjects and reporting on 494 allelic contrasts were retrieved. Data were available on 67 TERT locus polymorphisms and 24 tumor types, for a total of 221 unique combinations of polymorphisms and cancer types. Upon meta-analysis, a statistically significant association with the risk of any cancer type was found for 22 polymorphisms. Strong, moderate, and weak cumulative evidence for association with at least one tumor type was demonstrated for 11, 9, and 14 polymorphisms, respectively. For lung cancer, which was the most studied tumor type, the estimated joint population attributable risk for three polymorphisms (TERT rs2736100, intergenic rs4635969, and CLPTM1L rs402710) was 41%. Strong evidence for lack of association was identified for five polymorphisms in three tumor types. Conclusions To our knowledge, this is the largest collection of data for associations between TERT locus polymorphisms and cancer risk. Our findings support the hypothesis that genetic variability in this genomic region can modulate cancer susceptibility in humans. PMID:22523397
Group cohesion and social support of the nurses in a special unit and a general unit in Korea.
Ko, Yu Kyung
2011-07-01
To identify the degree of group cohesion and social support of nurses in special and general units in hospitals in Korea, and to compare group cohesion and social support between the two groups. The level of commitment nurses have to their organizations has been shown to correlate with work group cohesion and social support. The participants were 1751 nurses who were working in Korean hospitals. Data were collected using a structured questionnaire and were analysed using SAS. The statistical methods included: descriptive statistics, t-test, anova and Pearson's correlation coefficients. Group cohesion of nurses on special wards was significantly higher than for nurses on general wards. No significant difference was found between types of units in terms of social support. The degree of group cohesion was significantly different in terms of the respondents' clinical experience, position, religion, job satisfaction, number of supportive superiors and number of supportive peers. A statistically significant correlation was found between group cohesion scores and degree of social support. Hospital management can accomplish their goals more effectively through knowledge of the level of group cohesion, superior support and peer support for nursing staff in accordance with unit specialty. © 2011 The Author. Journal compilation © 2011 Blackwell Publishing Ltd.
Wind speed statistics for Goldstone, California, anemometer sites
NASA Technical Reports Server (NTRS)
Berg, M.; Levy, R.; Mcginness, H.; Strain, D.
1981-01-01
An exploratory wind survey at an antenna complex was summarized statistically for application to future windmill designs. Data were collected at six locations from a total of 10 anemometers. Statistics include means, standard deviations, cubes, pattern factors, correlation coefficients, and exponents for power law profile of wind speed. Curves presented include: mean monthly wind speeds, moving averages, and diurnal variation patterns. It is concluded that three of the locations have sufficiently strong winds to justify consideration for windmill sites.
NASA Astrophysics Data System (ADS)
Müller, M. F.; Thompson, S. E.
2016-02-01
The prediction of flow duration curves (FDCs) in ungauged basins remains an important task for hydrologists given the practical relevance of FDCs for water management and infrastructure design. Predicting FDCs in ungauged basins typically requires spatial interpolation of statistical or model parameters. This task is complicated if climate becomes non-stationary, as the prediction challenge now also requires extrapolation through time. In this context, process-based models for FDCs that mechanistically link the streamflow distribution to climate and landscape factors may have an advantage over purely statistical methods to predict FDCs. This study compares a stochastic (process-based) and statistical method for FDC prediction in both stationary and non-stationary contexts, using Nepal as a case study. Under contemporary conditions, both models perform well in predicting FDCs, with Nash-Sutcliffe coefficients above 0.80 in 75 % of the tested catchments. The main drivers of uncertainty differ between the models: parameter interpolation was the main source of error for the statistical model, while violations of the assumptions of the process-based model represented the main source of its error. The process-based approach performed better than the statistical approach in numerical simulations with non-stationary climate drivers. The predictions of the statistical method under non-stationary rainfall conditions were poor if (i) local runoff coefficients were not accurately determined from the gauge network, or (ii) streamflow variability was strongly affected by changes in rainfall. A Monte Carlo analysis shows that the streamflow regimes in catchments characterized by frequent wet-season runoff and a rapid, strongly non-linear hydrologic response are particularly sensitive to changes in rainfall statistics. In these cases, process-based prediction approaches are favored over statistical models.
Psychometric properties of the Chinese Internet Gaming Disorder Scale.
Sigerson, Leif; Li, Angel Y-L; Cheung, Mike W-L; Luk, Jeremy W; Cheng, Cecilia
2017-11-01
To develop a consensus on the definition and measurement of Internet gaming disorder (IGD), several recent studies have used the DSM-5's proposed criteria for IGD as the basis in scale construction. This study contributes to this emerging consensus by developing and validating a new Chinese Internet Gaming Disorder Scale (C-IGDS) based on the DSM-5 criteria. A representative sample of Hong Kong community adults (n=502, 50% men, mean age=37.1, age range=18-60) was recruited for a telephone survey with random digit dialing. Various statistical techniques were used to assess the psychometric properties of the C-IGDS. The C-IGDS had good reliability (Cronbach's α=0.91) and structural validity (CFA model fit: RMSEA=0.027, CFI=0.991, TLI=0.988) in our sample. Moderate to moderately strong correlations with depressive symptoms (r=0.617, p<0.001), social anxiety symptoms (r=0.366, p<0.001), and gaming hours (r=0.412, p<0.001) supported the criterion validity of the C-IGDS. In addition, the C-IGDS exhibited strict measurement invariance for sex and at least strong measurement invariance for age. In addition to providing the first Chinese scale for measuring IGD based on the DSM-5's proposed criteria, this study provides empirical support for the validity of these diagnostic criteria as the basis for a universal measure of IGD. Most important, this study is the first to reveal the criteria's measurement invariance, thereby indicating their suitability for use with diverse demographic groups. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Dimitropoulou, M.; Isliker, H.; Vlahos, L.; Georgoulis, M.; Anastasiadis, A.; Toutountzi, A.
2013-09-01
We treat flaring solar active regions as physical systems having reached the self-organized critical state. Their evolving magnetic configurations in the low corona may satisfy an instability criterion, related to the excession of a specific threshold in the curl of the magnetic field. This imposed instability criterion implies an almost zero resistivity everywhere in the solar corona, except in regions where magnetic-field discontinuities and. hence, local currents, reach the critical value. In these areas, current-driven instabilities enhance the resistivity by many orders of magnitude forming structures which efficiently accelerate charged particles. Simulating the formation of such structures (thought of as current sheets) via a refined SOC cellular-automaton model provides interesting information regarding their statistical properties. It is shown that the current density in such unstable regions follows power-law scaling. Furthermore, the size distribution of the produced current sheets is best fitted by power laws, whereas their formation probability is investigated against the photospheric magnetic configuration (e.g. Polarity Inversion Lines, Plage). The average fractal dimension of the produced current sheets is deduced depending on the selected critical threshold. The above-mentioned statistical description of intermittent electric field structures can be used by collisional relativistic test particle simulations, aiming to interpret particle acceleration in flaring active regions and in strongly turbulent media in astrophysical plasmas. The above work is supported by the Hellenic National Space Weather Research Network (HNSWRN) via the THALIS Programme.
Guo, Hao; Cao, Xiaohua; Liu, Zhifen; Li, Haifang; Chen, Junjie; Zhang, Kerang
2012-12-05
Resting state functional brain networks have been widely studied in brain disease research. However, it is currently unclear whether abnormal resting state functional brain network metrics can be used with machine learning for the classification of brain diseases. Resting state functional brain networks were constructed for 28 healthy controls and 38 major depressive disorder patients by thresholding partial correlation matrices of 90 regions. Three nodal metrics were calculated using graph theory-based approaches. Nonparametric permutation tests were then used for group comparisons of topological metrics, which were used as classified features in six different algorithms. We used statistical significance as the threshold for selecting features and measured the accuracies of six classifiers with different number of features. A sensitivity analysis method was used to evaluate the importance of different features. The result indicated that some of the regions exhibited significantly abnormal nodal centralities, including the limbic system, basal ganglia, medial temporal, and prefrontal regions. Support vector machine with radial basis kernel function algorithm and neural network algorithm exhibited the highest average accuracy (79.27 and 78.22%, respectively) with 28 features (P<0.05). Correlation analysis between feature importance and the statistical significance of metrics was investigated, and the results revealed a strong positive correlation between them. Overall, the current study demonstrated that major depressive disorder is associated with abnormal functional brain network topological metrics and statistically significant nodal metrics can be successfully used for feature selection in classification algorithms.
Particle size and support effects in electrocatalysis.
Hayden, Brian E
2013-08-20
Researchers increasingly recognize that, as with standard supported heterogeneous catalysts, the activity and selectivity of supported metal electrocatalysts are influenced by particle size, particle structure, and catalyst support. Studies using model supported heterogeneous catalysts have provided information about these effects. Similarly, model electrochemical studies on supported metal electrocatalysts can provide insight into the factors determining catalytic activity. High-throughput methods for catalyst synthesis and screening can determine systematic trends in activity as a function of support and particle size with excellent statistical certainty. In this Account, we describe several such studies investigating methods for dispersing precious metals on both carbon and oxide supports, with particular emphasis on the prospects for the development of low-temperature fuel-cell electrocatalysts. One key finding is a decrease in catalytic activity with decreasing particle size independent of the support for both oxygen reduction and CO oxidation on supported gold and platinum. For these reactions, there appears to be an intrinsic particle size effect that results in a loss of activity at particle sizes below 2-3 nm. A titania support, however, also increases activity of gold particles in the electrooxidation of CO and in the reduction of oxygen, with an optimum at 3 nm particle size. This optimum may represent the superposition of competing effects: a titania-induced enhanced activity versus deactivation at small particle sizes. The titania support shows catalytic activity at potentials where carbon-supported and bulk-gold surfaces are normally oxidized and CO electrooxidation is poisoned. On the other hand, platinum on amorphous titania shows a different effect: the oxidation reduction reaction is strongly poisoned in the same particle size range. We correlated the influence of the titania support with titania-induced changes in the surface redox behavior of the platinum particles. For both supported gold and platinum particles in electrocatalysis, we observe parallels to the effects of particle size and support in the equivalent heterogeneous catalysts. Studies of model supported-metal electrocatalysts, performs efficiently using high throughput synthetic and screening methodologies, will lead to a better understanding of the mechanisms responsible for support and particle size effects in electrocatalysis, and will drive the development of more effective and robust catalysts in the future.
Vainik, Uku; Konstabel, Kenn; Lätt, Evelin; Mäestu, Jarek; Purge, Priit; Jürimäe, Jaak
2016-10-01
Subjective energy intake (sEI) is often misreported, providing unreliable estimates of energy consumed. Therefore, relating sEI data to health outcomes is difficult. Recently, Börnhorst et al. compared various methods to correct sEI-based energy intake estimates. They criticised approaches that categorise participants as under-reporters, plausible reporters and over-reporters based on the sEI:total energy expenditure (TEE) ratio, and thereafter use these categories as statistical covariates or exclusion criteria. Instead, they recommended using external predictors of sEI misreporting as statistical covariates. We sought to confirm and extend these findings. Using a sample of 190 adolescent boys (mean age=14), we demonstrated that dual-energy X-ray absorptiometry-measured fat-free mass is strongly associated with objective energy intake data (onsite weighted breakfast), but the association with sEI (previous 3-d dietary interview) is weak. Comparing sEI with TEE revealed that sEI was mostly under-reported (74 %). Interestingly, statistically controlling for dietary reporting groups or restricting samples to plausible reporters created a stronger-than-expected association between fat-free mass and sEI. However, the association was an artifact caused by selection bias - that is, data re-sampling and simulations showed that these methods overestimated the effect size because fat-free mass was related to sEI both directly and indirectly via TEE. A more realistic association between sEI and fat-free mass was obtained when the model included common predictors of misreporting (e.g. BMI, restraint). To conclude, restricting sEI data only to plausible reporters can cause selection bias and inflated associations in later analyses. Therefore, we further support statistically correcting sEI data in nutritional analyses. The script for running simulations is provided.
Enhancing residents’ neonatal resuscitation competency through unannounced simulation-based training
Surcouf, Jeffrey W.; Chauvin, Sheila W.; Ferry, Jenelle; Yang, Tong; Barkemeyer, Brian
2013-01-01
Background Almost half of pediatric third-year residents surveyed in 2000 had never led a resuscitation event. With increasing restrictions on residency work hours and a decline in patient volume in some hospitals, there is potential for fewer opportunities. Purpose Our primary purpose was to test the hypothesis that an unannounced mock resuscitation in a high-fidelity in-situ simulation training program would improve both residents’ self-confidence and observed performance of adopted best practices in neonatal resuscitation. Methods Each pediatric and medicine–pediatric resident in one pediatric residency program responded to an unannounced scenario that required resuscitation of the high fidelity infant simulator. Structured debriefing followed in the same setting, and a second cycle of scenario response and debriefing occurred before ending the 1-hour training experience. Measures included pre- and post-program confidence questionnaires and trained observer assessments of live and videotaped performances. Results Statistically significant pre–post gains for self-confidence were observed for 8 of the 14 NRP critical behaviors (p=0.00–0.03) reflecting knowledge, technical, and non-technical (teamwork) skills. The pre–post gain in overall confidence score was statistically significant (p=0.00). With a maximum possible assessment score of 41, the average pre–post gain was 8.28 and statistically significant (p<0.001). Results of the video-based assessments revealed statistically significant performance gains (p<0.0001). Correlation between live and video-based assessments were strong for pre–post training scenario performances (pre: r=0.64, p<0.0001; post: r=0.75, p<0.0001). Conclusions Results revealed high receptivity to in-situ, simulation-based training and significant positive gains in confidence and observed competency-related abilities. Results support the potential for other applications in residency and continuing education. PMID:23522399
Nagata, Chisato; Mizoue, Tetsuya; Tanaka, Keitaro; Tsuji, Ichiro; Tamakoshi, Akiko; Matsuo, Keitaro; Wakai, Kenji; Inoue, Manami; Tsugane, Shoichiro; Sasazuki, Shizuka
2014-03-01
We reviewed epidemiological studies of soy intake and breast cancer among Japanese women. This report is one among a series of articles by our research group, which is evaluating the existing evidence concerning the association between health-related lifestyles and cancer. Original data were obtained from MEDLINE searches using PubMed or from searches of the Ichushi database, complemented with manual searches. Evaluation of associations was based on the strength of evidence and the magnitude of association, together with biological plausibility. Five cohort studies and six case-control studies were identified. Among the cohort studies, two studies observed that total soy intake (in terms of total amounts of soy foods or soy isoflavones) was associated with a moderate (0.5 ≤ relative risk ≤ 0.67 with statistical significance) or strong (relative risk ≤ 0.5 with statistical significance) risk reduction of breast cancer in postmenopausal women. Among the case-control studies, two studies reported a weak (0.67 ≤ odds ratio ≤ 1.5 with statistical significance or 0.5 ≤ odds ratio ≤ 0.67 without statistical significance) inverse association between total soy intake and the risk of breast cancer. In the former, this association was observed in all women combined-premenopausal and postmenopausal women-but in the latter, the association was confined to postmenopausal women. The associations of intakes of individual soy foods with the risk of breast cancer were generally null. There is some evidence that supports the biological plausibility of a protective effect of isoflavones on breast cancer risk. We conclude that soy intake possibly decreases the risk of breast cancer among Japanese women.
Keith, Jeff; Westbury, Chris; Goldman, James
2015-09-01
Corpus-based semantic space models, which primarily rely on lexical co-occurrence statistics, have proven effective in modeling and predicting human behavior in a number of experimental paradigms that explore semantic memory representation. The most widely studied extant models, however, are strongly influenced by orthographic word frequency (e.g., Shaoul & Westbury, Behavior Research Methods, 38, 190-195, 2006). This has the implication that high-frequency closed-class words can potentially bias co-occurrence statistics. Because these closed-class words are purported to carry primarily syntactic, rather than semantic, information, the performance of corpus-based semantic space models may be improved by excluding closed-class words (using stop lists) from co-occurrence statistics, while retaining their syntactic information through other means (e.g., part-of-speech tagging and/or affixes from inflected word forms). Additionally, very little work has been done to explore the effect of employing morphological decomposition on the inflected forms of words in corpora prior to compiling co-occurrence statistics, despite (controversial) evidence that humans perform early morphological decomposition in semantic processing. In this study, we explored the impact of these factors on corpus-based semantic space models. From this study, morphological decomposition appears to significantly improve performance in word-word co-occurrence semantic space models, providing some support for the claim that sublexical information-specifically, word morphology-plays a role in lexical semantic processing. An overall decrease in performance was observed in models employing stop lists (e.g., excluding closed-class words). Furthermore, we found some evidence that weakens the claim that closed-class words supply primarily syntactic information in word-word co-occurrence semantic space models.
47 CFR 54.807 - Interstate access universal service support.
Code of Federal Regulations, 2010 CFR
2010-10-01
... Common Carrier Bureau Report, Statistics of Communications Common Carriers, Table 6.10—Selected Operating Statistics. Interested parties may obtain this report from the U.S. Government Printing Office or by... Bureau Report, Statistics of Communications Common Carriers, Table 6.10—Selected Operating Statistics...
THE Role OF Anisotropy AND Intermittency IN Solar Wind/Magnetosphere Coupling
NASA Astrophysics Data System (ADS)
Jankovicova, D.; Voros, Z.
2006-12-01
Turbulent fluctuations are common in the solar wind as well as in the Earth's magnetosphere. The fluctuations of both magnetic field and plasma parameters exhibit non-Gaussian statistics. Neither the amplitude of these fluctuations nor their spectral characteristics can provide a full statistical description of multi-scale features in turbulence. It substantiates a statistical approach including the estimation of experimentally accessible statistical moments. In this contribution, we will directly estimate the third (skewness) and the fourth (kurtosis) statistical moments from the available time series of magnetic measurements in the solar wind (ACE and WIND spacecraft) and in the Earth's magnetosphere (SYM-H index). Then we evaluate how the statistical moments change during strong and weak solar wind/magnetosphere coupling intervals.
The role of digital tomosynthesis in reducing the number of equivocal breast reportings
NASA Astrophysics Data System (ADS)
Alakhras, Maram; Mello-Thoms, Claudia; Rickard, Mary; Bourne, Roger; Brennan, Patrick C.
2015-03-01
Purpose To compare radiologists' confidence in assessing breast cancer using combined digital mammography (DM) and digital breast tomosynthesis (DBT) compared with DM alone as a function of previous experience with DBT. Materials and Methods Institutional ethics approval was obtained. Twenty-three experienced breast radiologists reviewed 50 cases in two modes, DM alone and DM+DBT. Twenty-seven cases presented with breast cancer. Each radiologist was asked to detect breast lesions and give a confidence score of 1-5 (1- Normal, 2- Benign, 3- Equivocal, 4- Suspicious, 5- Malignant). Radiologists were divided into three sub-groups according to their prior experience with DBT (none, workshop experience, and clinical experience). Confidence scores using DM+DBT were compared with DM alone for all readers combined and for each DBT experience subgroup. Statistical analyses, using GraphPad Prism 5, were carried out using the Wilcoxon signed-rank test with statistical significance set at p< 0.05. Results Confidence scores were higher for true positive cancer cases using DM+DBT compared with DM alone for all readers (p < 0.0001). Confidence scores for normal cases were lower (indicating greater confidence in the non-cancer diagnosis) with DM+DBT compared with DM alone for all readers (p= 0.018) and readers with no prior DBT experience (p= 0.035). Conclusion Addition of DBT to DM increases the confidence level of radiologists in scoring cancer and normal/benign cases. This finding appears to apply across radiologists with varying levels of DBT experience, however further work involving greater numbers of radiologists is required.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Zuo, Pingbing; Feng, Xueshang; Wang, Yi
In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs atmore » different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector.« less
In analyses supporting the development of numeric nutrient criteria, multiple statistical techniques can be used to extract critical values from stressor response relationships. However there is little guidance for choosing among techniques, and the extent to which log-transfor...
Teaching Probability with the Support of the R Statistical Software
ERIC Educational Resources Information Center
dos Santos Ferreira, Robson; Kataoka, Verônica Yumi; Karrer, Monica
2014-01-01
The objective of this paper is to discuss aspects of high school students' learning of probability in a context where they are supported by the statistical software R. We report on the application of a teaching experiment, constructed using the perspective of Gal's probabilistic literacy and Papert's constructionism. The results show improvement…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Choudhary, V.R.; Mulla, S.A.R.; Uphade, B.S.
1997-06-01
Methane-to-C{sub 2}-hydrocarbon conversion activity and selectivity (or yield) of MgO and La-promoted MgO catalysts in the oxidative coupling of methane and strong basicity of the catalysts are decreased appreciably when these catalysts are deposited on commonly used commercial low surface area porous catalyst carriers containing Al{sub 2}O{sub 3}, SiO{sub 2}, SiC, or ZrO{sub 2} + HfO{sub 2} as the main components. The decrease in the strong basicity and catalytic activity/selectivity or yield is mostly due to strong chemical interactions between the active catalyst component (viz., MgO and La{sub 2}O{sub 3}) and the reactive components of the catalyst support (viz., Al{submore » 2}O{sub 3} and SiO{sub 2}), resulting in the formation of catalytically inactive binary metal oxides on the support surface. However, the influence of support on the activity/selectivity of La{sub 2}O{sub 3} is relatively very small, and also the chemical interactions of La{sub 2}O{sub 3} with the supports (except that containing a high concentration of SiO{sub 2}) are almost absent. The catalyst-support interactions are thus found to be strongly dependent upon the nature (chemical composition) of both catalyst and support. For developing better supported catalysts for the oxidative coupling of methane, supported La{sub 2}O{sub 3} with some promoters shows high promise.« less
... Controls Cancel Submit Search the CDC Venous Thromboembolism (Blood Clots) Note: Javascript is disabled or is not supported ... Challenge HA-VTE Data & Statistics HA-VTE Resources Blood Clots and Travel Research and Treatment Centers Data & Statistics ...
Fast numerical methods for simulating large-scale integrate-and-fire neuronal networks.
Rangan, Aaditya V; Cai, David
2007-02-01
We discuss numerical methods for simulating large-scale, integrate-and-fire (I&F) neuronal networks. Important elements in our numerical methods are (i) a neurophysiologically inspired integrating factor which casts the solution as a numerically tractable integral equation, and allows us to obtain stable and accurate individual neuronal trajectories (i.e., voltage and conductance time-courses) even when the I&F neuronal equations are stiff, such as in strongly fluctuating, high-conductance states; (ii) an iterated process of spike-spike corrections within groups of strongly coupled neurons to account for spike-spike interactions within a single large numerical time-step; and (iii) a clustering procedure of firing events in the network to take advantage of localized architectures, such as spatial scales of strong local interactions, which are often present in large-scale computational models-for example, those of the primary visual cortex. (We note that the spike-spike corrections in our methods are more involved than the correction of single neuron spike-time via a polynomial interpolation as in the modified Runge-Kutta methods commonly used in simulations of I&F neuronal networks.) Our methods can evolve networks with relatively strong local interactions in an asymptotically optimal way such that each neuron fires approximately once in [Formula: see text] operations, where N is the number of neurons in the system. We note that quantifications used in computational modeling are often statistical, since measurements in a real experiment to characterize physiological systems are typically statistical, such as firing rate, interspike interval distributions, and spike-triggered voltage distributions. We emphasize that it takes much less computational effort to resolve statistical properties of certain I&F neuronal networks than to fully resolve trajectories of each and every neuron within the system. For networks operating in realistic dynamical regimes, such as strongly fluctuating, high-conductance states, our methods are designed to achieve statistical accuracy when very large time-steps are used. Moreover, our methods can also achieve trajectory-wise accuracy when small time-steps are used.
Record statistics of a strongly correlated time series: random walks and Lévy flights
NASA Astrophysics Data System (ADS)
Godrèche, Claude; Majumdar, Satya N.; Schehr, Grégory
2017-08-01
We review recent advances on the record statistics of strongly correlated time series, whose entries denote the positions of a random walk or a Lévy flight on a line. After a brief survey of the theory of records for independent and identically distributed random variables, we focus on random walks. During the last few years, it was indeed realized that random walks are a very useful ‘laboratory’ to test the effects of correlations on the record statistics. We start with the simple one-dimensional random walk with symmetric jumps (both continuous and discrete) and discuss in detail the statistics of the number of records, as well as of the ages of the records, i.e. the lapses of time between two successive record breaking events. Then we review the results that were obtained for a wide variety of random walk models, including random walks with a linear drift, continuous time random walks, constrained random walks (like the random walk bridge) and the case of multiple independent random walkers. Finally, we discuss further observables related to records, like the record increments, as well as some questions raised by physical applications of record statistics, like the effects of measurement error and noise.
Empirical investigation into depth-resolution of Magnetotelluric data
NASA Astrophysics Data System (ADS)
Piana Agostinetti, N.; Ogaya, X.
2017-12-01
We investigate the depth-resolution of MT data comparing reconstructed 1D resistivity profiles with measured resistivity and lithostratigraphy from borehole data. Inversion of MT data has been widely used to reconstruct the 1D fine-layered resistivity structure beneath an isolated Magnetotelluric (MT) station. Uncorrelated noise is generally assumed to be associated to MT data. However, wrong assumptions on error statistics have been proved to strongly bias the results obtained in geophysical inversions. In particular the number of resolved layers at depth strongly depends on error statistics. In this study, we applied a trans-dimensional McMC algorithm for reconstructing the 1D resistivity profile near-by the location of a 1500 m-deep borehole, using MT data. We resolve the MT inverse problem imposing different models for the error statistics associated to the MT data. Following a Hierachical Bayes' approach, we also inverted for the hyper-parameters associated to each error statistics model. Preliminary results indicate that assuming un-correlated noise leads to a number of resolved layers larger than expected from the retrieved lithostratigraphy. Moreover, comparing the inversion of synthetic resistivity data obtained from the "true" resistivity stratification measured along the borehole shows that a consistent number of resistivity layers can be obtained using a Gaussian model for the error statistics, with substantial correlation length.
Effects of roughness on density-weighted particle statistics in turbulent channel flows
DOE Office of Scientific and Technical Information (OSTI.GOV)
Milici, Barbara
2015-12-31
The distribution of inertial particles in turbulent flows is strongly influenced by the characteristics of the coherent turbulent structures which develop in the carrier flow field. In wall-bounded flows, these turbulent structures, which control the turbulent regeneration cycles, are strongly affected by the roughness of the wall, nevertheless its effects on the particle transport in two-phase turbulent flows has been still poorly investigated. The issue is discussed here by addressing DNS combined with LPT to obtain statistics of velocity and preferential accumulation of a dilute dispersion of heavy particles in a turbulent channel flow, bounded by irregular two-dimensional rough surfaces,more » in the one-way coupling regime.« less
NASA Astrophysics Data System (ADS)
McFarland, Michael Duane
The purpose of this investigation is to measure the spatial, spectral and statistical properties of the high (/omega/ ~/ ω pe) and low (/omega/ ~/ ωpi) frequency electrostatic fluctuations in an unmagnetized, statistically stable, beam-driven, strongly turbulent plasma and compare the results to theoretical predictions. In addition the scattering of the electron beam in both angle and energy is measured and compared to theory. This study is motivated by the recent advances in statistical theories of strong Langmuir turbulence and the glaring lack of confirmatory experimental data. With the advent of modern computers and electronics, enormous data sets are now routinely digitize and subjected to sophisticated statistical and spectral analysis. These methods, along with traditional procedures and an innovative technique known as a 'conditional trigger', are used to extract ensemble averages from the turbulent system for comparison with the theoretical models. It is found that the high-frequency fluctuations consist of low-level wave activity /langle W/rangle/ ~/ 10-2 - 103 punctuated by semi-periodic, intense, spiky field events /langle W/rangle/ ~/ 1, where /langle W/rangle is the normalized intensity. The low- level wave activity has a spectral spread Δ k/k/ ~/ /Delta/omega//omega/ ~ 30%, dispersion relation v beam/ ~/ /omega/k, and correlation length lc/ /approx/ 3λES, where λES is the electrostatic wavelength, and shows evidence of low-intensity parametric decay products. The intense field events, on the other hand, show little correlation for l/ >/ λES, have a full-width-at-half-maximum of 1 f/ < 40/ λ D, where λ D is the Debye length, and are non-propagating. The statistical properties of the fluctuations compares well with the predictions of the two-component model of strong Langmuir turbulence. In addition, freely traveling waves, 'free modes', are observed to be produced by the localized wave structures for the first time. The peak of the low frequency fluctuations is found to scale inversely with the average time between collapse events. The magnitude of the low-frequency fluctuations Δ n/n is compared to the two-component model of strong Langmuir turbulence. It is found that
Infant Statistical-Learning Ability Is Related to Real-Time Language Processing
ERIC Educational Resources Information Center
Lany, Jill; Shoaib, Amber; Thompson, Abbie; Estes, Katharine Graf
2018-01-01
Infants are adept at learning statistical regularities in artificial language materials, suggesting that the ability to learn statistical structure may support language development. Indeed, infants who perform better on statistical learning tasks tend to be more advanced in parental reports of infants' language skills. Work with adults suggests…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hogan, Craig
It is argued by extrapolation of general relativity and quantum mechanics that a classical inertial frame corresponds to a statistically defined observable that rotationally fluctuates due to Planck scale indeterminacy. Physical effects of exotic nonlocal rotational correlations on large scale field states are estimated. Their entanglement with the strong interaction vacuum is estimated to produce a universal, statistical centrifugal acceleration that resembles the observed cosmological constant.
ERIC Educational Resources Information Center
Andersson, Gerhard; Ghaderi, Ata
2006-01-01
While a majority of cognitive behavioural researchers and clinicians adhere to the classification system provided in the "Diagnostic and Statistical Manual of Mental Disorders (DSM-IV)," strong objections have been voiced among behaviourists who find the dichotomous allocation of patients into psychiatric diagnoses incompatible with the philosophy…
Stability in a fiber bundle model: Existence of strong links and the effect of disorder
NASA Astrophysics Data System (ADS)
Roy, Subhadeep
2018-05-01
The present paper deals with a fiber bundle model which consists of a fraction α of infinitely strong fibers. The inclusion of such an unbreakable fraction has been proven to affect the failure process in early studies, especially around a critical value αc. The present work has a twofold purpose: (i) a study of failure abruptness, mainly the brittle to quasibrittle transition point with varying α and (ii) variation of αc as we change the strength of disorder introduced in the model. The brittle to quasibrittle transition is confirmed from the failure abruptness. On the other hand, the αc is obtained from the knowledge of failure abruptness as well as the statistics of avalanches. It is observed that the brittle to quasibrittle transition point scales to lower values, suggesting more quasi-brittle-like continuous failure when α is increased. At the same time, the bundle becomes stronger as there are larger numbers of strong links to support the external stress. High α in a highly disordered bundle leads to an ideal situation where the bundle strength, as well as the predictability in failure process is very high. Also, the critical fraction αc, required to make the model deviate from the conventional results, increases with decreasing strength of disorder. The analytical expression for αc shows good agreement with the numerical results. Finally, the findings in the paper are compared with previous results and real-life applications of composite materials.
Geospatial Characterization of Fluvial Wood Arrangement in a Semi-confined Alluvial River
NASA Astrophysics Data System (ADS)
Martin, D. J.; Harden, C. P.; Pavlowsky, R. T.
2014-12-01
Large woody debris (LWD) has become universally recognized as an integral component of fluvial systems, and as a result, has become increasingly common as a river restoration tool. However, "natural" processes of wood recruitment and the subsequent arrangement of LWD within the river network are poorly understood. This research used a suite of spatial statistics to investigate longitudinal arrangement patterns of LWD in a low-gradient, Midwestern river. First, a large-scale GPS inventory of LWD, performed on the Big River in the eastern Missouri Ozarks, resulted in over 4,000 logged positions of LWD along seven river segments that covered nearly 100 km of the 237 km river system. A global Moran's I analysis indicates that LWD density is spatially autocorrelated and displays a clustering tendency within all seven river segments (P-value range = 0.000 to 0.054). A local Moran's I analysis identified specific locations along the segments where clustering occurs and revealed that, on average, clusters of LWD density (high or low) spanned 400 m. Spectral analyses revealed that, in some segments, LWD density is spatially periodic. Two segments displayed strong periodicity, while the remaining segments displayed varying degrees of noisiness. Periodicity showed a positive association with gravel bar spacing and meander wavelength, although there were insufficient data to statistically confirm the relationship. A wavelet analysis was then performed to investigate periodicity relative to location along the segment. The wavelet analysis identified significant (α = 0.05) periodicity at discrete locations along each of the segments. Those reaches yielding strong periodicity showed stronger relationships between LWD density and the geomorphic/riparian independent variables tested. Analyses consistently identified valley width and sinuosity as being associated with LWD density. The results of these analyses contribute a new perspective on the longitudinal distribution of LWD in a river system, which should help identify physical and/or riparian control mechanisms of LWD arrangement and support the development of models of LWD arrangement. Additionally, the spatial statistical tools presented here have shown to be valuable for identifying longitudinal patterns in river system components.
Shankar, Ganesh M; Clarke, Michelle J; Ailon, Tamir; Rhines, Laurence D; Patel, Shreyaskumar R; Sahgal, Arjun; Laufer, Ilya; Chou, Dean; Bilsky, Mark H; Sciubba, Daniel M; Fehlings, Michael G; Fisher, Charles G; Gokaslan, Ziya L; Shin, John H
2017-07-01
OBJECTIVE Primary osteosarcoma of the spine is a rare osseous neoplasm. While previously reported retrospective studies have demonstrated that overall patient survival is impacted mostly by en bloc resection and chemotherapy, the continued management of residual disease remains to be elucidated. This systematic review was designed to address the role of revision surgery and multimodal adjuvant therapy in cases in which en bloc excision is not initially achieved. METHODS A systematic literature search spanning the years 1966 to 2015 was performed on PubMed, Medline, EMBASE, and Web of Science to identify reports describing outcomes of patients who underwent biopsy alone, neurological decompression, or intralesional resection for osteosarcoma of the spine. Studies were reviewed qualitatively, and the clinical course of individual patients was aggregated for quantitative meta-analysis. RESULTS A total of 16 studies were identified for inclusion in the systematic review, of which 8 case reports were summarized qualitatively. These studies strongly support the role of chemotherapy for overall survival and moderately support adjuvant radiation therapy for local control. The meta-analysis revealed a statistically significant benefit in overall survival for performing revision tumor debulking (p = 0.01) and also for chemotherapy at relapse (p < 0.01). Adjuvant radiation therapy was associated with longer survival, although this did not reach statistical significance (p = 0.06). CONCLUSIONS While the initial therapeutic goal in the management of osteosarcoma of the spine is neoadjuvant chemotherapy followed by en bloc marginal resection, this objective is not always achievable given anatomical constraints and other limitations at the time of initial clinical presentation. This systematic review supports the continued aggressive use of revision surgery and multimodal adjuvant therapy when possible to improve outcomes in patients who initially undergo subtotal debulking of osteosarcoma. A limitation of this systematic review is that lesions amenable to subsequent resection or tumors inherently more sensitive to adjuvants would exaggerate a therapeutic effect of these interventions when studied in a retrospective fashion.
Perceived barriers to physical activity among Polish adolescents.
Jodkowska, Maria; Mazur, Joanna; Oblacińska, Anna
2015-01-01
To identify barriers to physical activity (PA) for adolescents according to the gender and age and examine the association between these barriers and youths' physical activity. 3346 students aged 10-16 years (1759 girls) took part in the cross-sectional, nationally representative study. For this paper the dataset was created from adolescents who reported perceived barriers to PA, N = 2300, (1259 girls), range 13-16 years. Barriers and physical activity (MVPA) were analysed for all participants, as well as by gender, age group and place of residence. Multiple regression analysis was used to examine the relationships between perceived barriers and physical inactivity for all and than separately for boys and girls. Lack of energy, lack of time and lack of support were three of the five barriers reported by more than 40% of adolescents, statistically more likely by girls than boys and older youth than younger. For boys - lack of time (OR = 2.56; CI = 1.66-3.96), lack of skills (OR = 2.35; CI = 1.94-3.95), lack of willpower (OR = 1.71, CI = 1.05-2.80) and lack of support (OR = 1.64, CI = 1.11-2.41) were the predictors contributing to low level of PA. For girls lack of skills (OR = 3.16, CI = 1.62-6.18), lack of energy (OR = 1.84, CI = 1.14-2.96), lack of support (OR = 1.64, CI = 1.07-2.54) and lack of time (OR = 1.61,CI = 1.00-2.60) were positively and statistically significant associated with physical inactivity. 1. Perceived barriers to physical activity among adolescents have strong negative impact on recommended PA level. For girls lack of skills is the strongest predictor of low PA, for boys - lack of time. 2. Identification more precisely barriers to physical activity among adolescents will enable to developed more effective interventions in high-risk populations.
DESIGNING ENVIRONMENTAL MONITORING DATABASES FOR STATISTIC ASSESSMENT
Databases designed for statistical analyses have characteristics that distinguish them from databases intended for general use. EMAP uses a probabilistic sampling design to collect data to produce statistical assessments of environmental conditions. In addition to supporting the ...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, J; Rubinstein, A; Ohrt, J
Purpose: To study the effect of strong magnetic field on three types of dosimeters using an electromagnet inside a Linac vault. Materials and Methods: Three types of dosimeters, thermoluminescent Dosimeters (TLDs), optically stimulated luminescent Dosimeters (OSLDs), and EBT3 Film were used to measure radiation dose response inside an electromagnet that could produce a strong magnetic field (B>1.5 T). The dosimeters were placed inside a plastic phantom between the two poles of the magnet, at approximately 3 meters from the iso-center of an Elekta Versa HD Linac. The B field was calibrated with a Gauss meter (Model: GM-2, AlphaLab Inc). Themore » dosimeters received ∼2 Gy with and without the presence of the 1.5 T magnetic field. The EBT3 films were scanned 24 hours before and 24 hours after irradiation. The TLD dosimeters were read 1 week after irradiation. The OSLDs were read two weeks after irradiation. The ratios of signals of dosimeters irradiated with the B field to the signals without the B field were calculated. Two experiments have been conducted so far. Results: The ratios (averaged over two experiments) of dosimeter signals with vs without B field were 0.994 for films, 0.994 for OSLDs, and 1.002 for TLDs. The statistical uncertainty was ∼3%. Conclusions: The three types of dosimeters (film, TLD, OSLD) seem not affected by the presence of a magnetic field (B=1.5 T) with the uncertainty of ∼3%. They may be suitable for QA purposes in a strong B field up to 1.5 T. More measurements will be conducted for reproducibility testing. We acknowledge research support from Elekta AB.« less
Oostingh, Elsje C; Steegers-Theunissen, Régine P M; de Vries, Jeanne H M; Laven, Joop S E; Koster, Maria P H
2017-04-01
To study associations between periconceptional dietary patterns and semen quality parameters. Prospective periconception cohort study. Tertiary hospital. One hundred and twenty-nine male partners of pregnant women who participated in the Rotterdam Periconception Cohort (Predict study). None. Semen quality parameters-ejaculate volume, sperm concentration, total sperm count, progressive motility, immotile sperm, and total motile sperm count (TMSC). Men included in our study were on average 35 (±6 standard deviation) years old and had a body mass index of 26.4 ± 4 kg/m 2 . Two dietary patterns were identified using principle component analysis, which were labeled as "healthy" and "unhealthy." An increase of one factor score (stated as β) represented an increase of 1 standard deviation. Sperm concentration (β = 0.278; 95% CI, 0.112-0.444), total sperm count (β = 1.369; 95% CI, 0.244-2.495), progressive motility (β = 4.305; 95% CI, 0.675-7.936), and TMSC (β = 0.319; 95% CI, 0.113-0.526) were all positively associated with a strong adherence to the healthy dietary pattern. Subgroup analysis showed that these associations were mainly present in men with a TMSC <10 million spermatozoa. Although there was a trend toward a diminution in semen quality, we found no statistically significant associations with strong adherence to the unhealthy dietary pattern. The positive associations between strong adherence to a healthy dietary pattern and semen parameters in men with poor semen quality support the importance of preconceptional tailored nutritional counseling and coaching of couples who are trying to conceive. Copyright © 2017 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Golaszewski, T
2001-01-01
To examine the literature from the past 20 years and identify those studies that support the economic merit of health promotion. A panel of experts was used to identify the top studies supporting the purpose of this article. Studies were chosen based on the following criteria: the study (1) examined the relationship between health risks and financial outcomes, or health promotion programs and financial outcomes; (2) provided strong and compelling financial data supporting the worth of health promotion; (3) had a high-quality methodology; (4) answered an important question or replicated important findings with superior methodology; and (5) represented U.S.-based initiatives published since 1980. After initially nominating a group of studies for consideration, panelists rated each on a scale from 1 to 3 representing their opinion of importance. Studies rating the highest were included for this discussion. Studies were analyzed by population characteristics, design, statistical tests, limitations, and results. This information was summarized for each identified article. A relationship between modifiable health risk factors and health care costs is supported by research. Health promotion interventions appear to provide positive financial returns, most notably for health care costs and absenteeism reduction. Private sector initiatives seem to be driving economic-based research. Overall, health promotion shows promising results for providing financial advantages for its sponsors; however, if this discipline is to show its true worth, considerable funding is needed from government or philanthropic sources to cover the substantial costs of quality research.
Illness Perceptions in Patients of Schizophrenia: A Preliminary Investigation from Lahore, Pakistan
Hussain, Sadia; Imran, Nazish; Hotiana, Usman Amin; Mazhar, Nauman; Asif, Aftab
2017-01-01
Background and Objective: Patient’s perception of their illness influences their healthcare decisions. The objectives of this study were to explore patient’s own beliefs about their illness (Schizophrenia) and perceived social support, and its impact on their attitudes toward pharmacological treatment in Lahore, Pakistan. Methods: This study was conducted at Mayo Hospital Lahore from March to September 2016. Hundred individuals suffering from Schizophrenia completed four questionnaires; a socio-demographic questionnaire, the Illness Perception Questionnaire for Schizophrenia(IPQ-S), Drug attitude Inventory-10 (DAI) and Multidimensional Scale of Perceived Social Support (PSS). Results: Stress, family problems, lack of friends & financial worries were endorsed strongly by patients as cause of their mental illness. Ambiguity regarding their mental illness duration and personal control was observed. Patients’ perceived significant negative consequences, negative emotional response, as well as had poor understanding of their mental illness and treatment effectiveness. Statistically significant gender differences in treatment control and illness coherence subscales of IPQS were observed. Drug attitude inventory was positively correlated with Treatment control subscale (p < .01) and negatively correlated with Illness coherence subscale of IPQS (p < .05). The negative consequences subscale and perceived social support was negatively correlated (p < .01). Conclusion: Patient’s perception about their own illness is predictor of their drug taking attitude and perceived social support. Study results should help to develop new interventions to correct inaccurate beliefs in patients with schizophrenia to improve illness outcome. PMID:29067048
A culture conducive to women's academic success: development of a measure.
Westring, Alyssa Friede; Speck, Rebecca M; Sammel, Mary Dupuis; Scott, Patricia; Tuton, Lucy Wolf; Grisso, Jeane Ann; Abbuhl, Stephanie
2012-11-01
The work environment culture inhibits women's career success in academic medicine. The lack of clarity and consistency in the definition, measurement, and analysis of culture constrains current research on the topic. The authors addressed this gap by defining the construct of a culture conducive to women's academic success (CCWAS) and creating a measure (i.e., tool) to evaluate it. First, the authors conducted a review of published literature, held focus groups, and consulted with subject matter experts to develop a measure of academic workplace culture for women. Then they developed and pilot-tested the measure with a convenience sample of women assistant professors. After refining the measure, they administered it, along with additional scales for validation, to 133 women assistant professors at the University of Pennsylvania. Finally, they conducted statistical analyses to explore the measure's nature and validity. A CCWAS consists of four distinct, but related, dimensions: equal access, work-life balance, freedom from gender biases, and supportive leadership. The authors found evidence that women within departments/divisions agree on the supportiveness of their units but that substantial differences among units exist. The analyses provided strong evidence for the reliability and validity of their measure. This report contributes to a growing understanding of women's academic medicine careers and provides a measure that researchers can use to assess the supportiveness of the culture for women assistant professors and that leaders can use to evaluate the effectiveness of interventions designed to increase the supportiveness of the environment for women faculty.
Baek, Kiook; Yang, Seonhee; Lee, Miyoung; Chung, Insung
2018-06-01
Many studies have reported negative psychological or physical effects of emotional labor. Relationship between work-related musculoskeletal disorder and psychosocial factors has been reported. To manage organizational and psychosocial factors of musculoskeletal disorder with work place intervention among emotional laborers, the factors contributing to musculoskeletal pain must be identified and clarified. Data from the fourth Korean Working Conditions Survey was analyzed. Based on the questionnaire, we selected emotional laborers and included 3,979 participants, excluding participants whose variables were of interest to the researcher. Weight variable was applied. The association with musculoskeletal pain and psychosocial factors, such as workload, monotonous work, job control, social support, and job satisfaction, was investigated. Univariate analysis demonstrated that there was a statistically significant relationship between social support, job satisfaction, and musculoskeletal pain. In multivariate analysis, job satisfaction showed a strong correlation with musculoskeletal pain at all sites. Social support was significantly associated with backache. Monotonous work seemed to reduce the pain in the neck and/or upper limbs. Job control and work intensity were not significantly associated with musculoskeletal pain. In this study, job satisfaction was significantly associated with musculoskeletal pain, and social support among the social psychological stressors could reduce musculoskeletal pain. However, unlike previously known, the presence of monotonous work resulted in reduced musculoskeletal pain. The results of this study will help to establish the direction of improvement of atmosphere in the workplace to prevent the musculoskeletal pain of emotional laborers.
Should College Education Play a Significant Role in Teaching Students about Ethics?
ERIC Educational Resources Information Center
Coleman, Phillip D.; Atkinson, John K.; Waduge, Shashie
2015-01-01
A ten question survey was administered to a medium size university in the Midwest. The responses were fashioned in a 5-item Likert Scale ranging from Strongly Disagree to Strongly Agree. The results were interpreted by SPSS and relationships, frequencies, and descriptive statistics were drawn from the results of this program. The purpose of this…
ERIC Educational Resources Information Center
Pollard, John A.; Austin, Gregory A.
There is a strong statistical correlation between delinquency activity level and the level of alcohol and other drug (AOD) use in adolescents. A strong association between drug use, drug trafficking, and youth gangs has also emerged. However, several important questions concerning the relationship of delinquency, gang membership, and AOD use…
IRIS Toxicological Review of Methanol (Noncancer) (Revised External Review Draft)
EPA is seeking additional public comment and external peer review of the scientific basis supporting the human health hazard and dose-response assessment of methanol (noncancer).
Test-retest reliability of an fMRI paradigm for studies of cardiovascular reactivity.
Sheu, Lei K; Jennings, J Richard; Gianaros, Peter J
2012-07-01
We examined the reliability of measures of fMRI, subjective, and cardiovascular reactions to standardized versions of a Stroop color-word task and a multisource interference task. A sample of 14 men and 12 women (30-49 years old) completed the tasks on two occasions, separated by a median of 88 days. The reliability of fMRI BOLD signal changes in brain areas engaged by the tasks was moderate, and aggregating fMRI BOLD signal changes across the tasks improved test-retest reliability metrics. These metrics included voxel-wise intraclass correlation coefficients (ICCs) and overlap ratio statistics. Task-aggregated ratings of subjective arousal, valence, and control, as well as cardiovascular reactions evoked by the tasks showed ICCs of 0.57 to 0.87 (ps < .001), indicating moderate-to-strong reliability. These findings support using these tasks as a battery for fMRI studies of cardiovascular reactivity. Copyright © 2012 Society for Psychophysiological Research.
Development of Individuality in Children's Handwriting.
Srihari, Sargur N; Meng, Lu; Hanson, Lisa
2016-09-01
Handwriting of children in early grades is studied from the viewpoint of quantitatively measuring the development of handwriting individuality. Handwriting samples of children, in grades 2-4, writing a paragraph of text in both handprinted and cursive, collected over a period of 3 years, were analyzed using two different approaches: (i) characteristics of the word "and" and (ii) entire paragraphs using an automated system. In the first approach, word characteristics were analyzed using statistical measures. In the second approach, pairs of paragraphs were compared. Both types of analysis, single word and complete writing, led to the same conclusions: (i) handwriting of each child remains relatively similar when handwriting has been just learnt and becomes markedly different from grades 3 to 4 and (ii) handwriting of different children becomes progressively more different from grades 2 to 4. The results provide strong support that handwriting becomes more individualistic with child development. © 2016 American Academy of Forensic Sciences.
Statistical moments of quantum-walk dynamics reveal topological quantum transitions.
Cardano, Filippo; Maffei, Maria; Massa, Francesco; Piccirillo, Bruno; de Lisio, Corrado; De Filippis, Giulio; Cataudella, Vittorio; Santamato, Enrico; Marrucci, Lorenzo
2016-04-22
Many phenomena in solid-state physics can be understood in terms of their topological properties. Recently, controlled protocols of quantum walk (QW) are proving to be effective simulators of such phenomena. Here we report the realization of a photonic QW showing both the trivial and the non-trivial topologies associated with chiral symmetry in one-dimensional (1D) periodic systems. We find that the probability distribution moments of the walker position after many steps can be used as direct indicators of the topological quantum transition: while varying a control parameter that defines the system phase, these moments exhibit a slope discontinuity at the transition point. Numerical simulations strongly support the conjecture that these features are general of 1D topological systems. Extending this approach to higher dimensions, different topological classes, and other typologies of quantum phases may offer general instruments for investigating and experimentally detecting quantum transitions in such complex systems.
Statistical moments of quantum-walk dynamics reveal topological quantum transitions
Cardano, Filippo; Maffei, Maria; Massa, Francesco; Piccirillo, Bruno; de Lisio, Corrado; De Filippis, Giulio; Cataudella, Vittorio; Santamato, Enrico; Marrucci, Lorenzo
2016-01-01
Many phenomena in solid-state physics can be understood in terms of their topological properties. Recently, controlled protocols of quantum walk (QW) are proving to be effective simulators of such phenomena. Here we report the realization of a photonic QW showing both the trivial and the non-trivial topologies associated with chiral symmetry in one-dimensional (1D) periodic systems. We find that the probability distribution moments of the walker position after many steps can be used as direct indicators of the topological quantum transition: while varying a control parameter that defines the system phase, these moments exhibit a slope discontinuity at the transition point. Numerical simulations strongly support the conjecture that these features are general of 1D topological systems. Extending this approach to higher dimensions, different topological classes, and other typologies of quantum phases may offer general instruments for investigating and experimentally detecting quantum transitions in such complex systems. PMID:27102945
Intradiscal platelet-rich plasma (PRP) injections for discogenic low back pain: an update.
Monfett, Michael; Harrison, Julian; Boachie-Adjei, Kwadwo; Lutz, Gregory
2016-06-01
The aim of this article is to provide an overview of clinical and translational research on intradiscal platelet-rich plasma (PRP) as a minimally invasive treatment for discogenic low back pain. A literature review of in vitro, in vivo, and clinical studies was performed. There is strong in vitro evidence that supports the use of intradiscal PRP for discogenic low back pain. There are also promising findings in select preclinical animal studies. A clinical study of 29 participants who underwent intradiscal PRP injections for discogenic low back pain found statistically and clinically significant improvements in pain and function through two years of follow-up. Intradiscal PRP is a safe and a possibly effective treatment for discogenic low back pain. Future studies are warranted to determine the best candidates for this treatment, what the optimal injectate is and what relationships exist between patient-reported outcomes and radiological findings.
An untold story in labor health: Korean women workers.
Kim, Myoung-Hee; Kim, Hyun-joo
2007-01-01
Very little is known about labor health among Korean women workers, who have been left behind by the occupational safety and health institutions. In this article, we examine, from a gender perspective, the occupational safety and health (OSH) statistics, institutions, and the struggles of women workers, and discuss how to make a society where women workers become and stay healthy. The problems Korean women workers face have both universal and unique aspects. On the one hand, they tend to be exposed to "invisible hazards" and to disproportionately suffer from neo-liberal policies, as do women workers in other countries. On the other hand, Korean women workers are still positioned under the strong patriarchy found in pre-modern societies. The examples of struggle presented here come out of this condition; those struggles by women workers and support from concerned specialists have played an important role in overcoming patriarchy and protecting health rights for women workers.
Killingsworth, Erin; Kimble, Laura P; Sudia, Tanya
2015-01-01
To explore the decision-making process of BSN faculty when determining which best practices to use for classroom testing. A descriptive, correlational study was conducted with a national sample (N = 127) of full-time BSN faculty. Participants completed a web-based survey incorporating instruments that measured beliefs about evaluation, decision-making, and best practices for item analysis and constructing and revising classroom tests. Study participants represented 31 states and were primarily middle-aged white women. In multiple linear regression analyses, faculty beliefs, contextual factors for decision-making, and decision-making processes accounted for statistically significant amounts of the variance in item analysis and test construction and revision. Strong faculty beliefs that rules were important when evaluating students was a significant predictor of increased use of best practices. Results support that understanding faculty beliefs around classroom testing is important in promoting the use of best practices.
NASA Astrophysics Data System (ADS)
Britten, Gregory L.; Wakamatsu, Lael; Primeau, François W.
2017-02-01
Carbon export from the Southern Ocean exerts a strong control on the ocean carbon sink, yet recent observations from the region demonstrate poorly understood relationships in which carbon export efficiency is weakly related to temperature. These observations conflict with traditional theory where export efficiency increases in colder waters. A recently proposed "temperature-ballast hypothesis" suggests an explanatory mechanism where the effect of temperature-dependent respiration is masked by variation in particle-ballast as upwelling waters move northward from Antarctica. We use observations and statistical models to test this mechanism and find positive support for the hypothesized temperature-ballast interactions. Best fitting models indicate a significant relation between export efficiency and silica-ballast while simultaneously revealing the expected inverse effect of temperature once ballast is accounted for. These findings reconcile model predictions, metabolic theory, and carbon export observations in the Southern Ocean and have consequences for how the ocean carbon sink responds to climate change.
Larsen, A. C.; Guttormsen, M.; Blasi, N.; ...
2017-04-24
Nuclear level densities and γ-ray strength functions of 56,57Fe have been extracted from proton-γ coincidences. A low-energy enhancement in the γ-ray strength functions up to a factor of 30 over common theoretical E1 models is confirmed. Angular distributions of the low-energy enhancement in 57Fe indicate its dipole nature, in agreement with findings for 56Fe. The high statistics and the excellent energy resolution of the large-volume LaBr 3(Ce) detectors allowed for a thorough analysis of γ strength as function of excitation energy. Taking into account the presence of strong Porter–Thomas fluctuations, there is no indication of any significant excitation energy dependencemore » in the γ-ray strength function, which is in support of the generalized Brink–Axel hypothesis.« less
NASA Astrophysics Data System (ADS)
Yadav, D.; Upadhyay, H. C.
1992-07-01
Vehicles obtain track-induced input through the wheels, which commonly number more than one. Analysis available for the vehicle response in a variable velocity run on a non-homogeneously profiled flexible track supported by compliant inertial foundation is for a linear heave model having a single ground input. This analysis is being extended to two point input models with heave-pitch and heave-roll degrees of freedom. Closed form expressions have been developed for the system response statistics. Results are presented for a railway coach and track/foundation problem, and the performances of heave, heave-pitch and heave-roll models have been compared. The three models are found to agree in describing the track response. However, the vehicle sprung mass behaviour is predicted to be different by these models, indicating the strong effect of coupling on the vehicle vibration.
Relationship between team assists and win-loss record in The National Basketball Association.
Melnick, M J
2001-04-01
Using research methodology for analysis of secondary data, statistical data for five National Basketball Association (NBA) seasons (1993-1994 to 1997-1998) were examined to test for a relationship between team assists (a behavioral measure of teamwork) and win-loss record. Rank-difference correlation indicated a significant relationship between the two variables, the coefficients ranging from .42 to .71. Team assist totals produced higher correlations with win-loss record than assist totals for the five players receiving the most playing time ("the starters"). A comparison of "assisted team points" and "unassisted team points" in relationship to win-loss record favored the former and strongly suggested that how a basketball team scores points is more important than the number of points it scores. These findings provide circumstantial support for the popular dictum in competitive team sports that "Teamwork Means Success-Work Together, Win Together."
Dynamic Conductivity and Partial Ionization in Warm, Dense Hydrogen
NASA Astrophysics Data System (ADS)
Zaghoo, M.; Silvera, I. F.
2017-10-01
A theoretical description for optical conduction experiments in dense fluid hydrogen is presented. Different quantum statistical approaches are used to describe the mechanism of electron transport in hydrogen's high-temperature dense phase. We show that at the onset of the metallic transition, optical conduction could be described by a strong rise in the atomic polarizability, resulting from increased ionization; whereas in the highly degenerate limit, the Ziman weak-scattering model better describes the observed saturation of reflectance. In the highly degenerate region, the inclusion of partial ionization effects provides excellent agreement with experimental results. Hydrogen's fluid metallic state is revealed to be a partially ionized free-electron plasma. These results provide a crucial benchmark for ab initio calculations as well as an important guide for future experiments. Research supported by DOE Stockpile Stewardship Academic Alliance Program, Grant DE-FG52-10NA29656, and NASA Earth and Space Science Fellowship Program, Award NNX14AP17H.
Haut, Jan; Gaum, Christian
2017-08-02
There is a widespread belief that success at the elite level leads to increasing mass participation in sports. However, this assumption is merely supported by empirical evidence and is analyzed here for the case of table tennis. Therefore long-term data (1964-2014) on participation in Germany, France and Austria is statistically tested for effects of success by the countries' athletes at international competitions. Results indicate that no general trickle-down effect can be confirmed for table tennis in the countries observed. Rather, findings are ambivalent, as a strong positive effect was found for the Austrian case, but a paradox relation for the German case, where elite success has been accompanied by decreasing participation in the last decades. Accordingly, as an "automatic" trickle-down effect is unlikely, more specific analyses and strategies seem necessary to use elite success as a lever for the promotion of the sport.
The confluence model: birth order as a within-family or between-family dynamic?
Zajonc, R B; Sulloway, Frank J
2007-09-01
The confluence model explains birth-order differences in intellectual performance by quantifying the changing dynamics within the family. Wichman, Rodgers, and MacCallum (2006) claimed that these differences are a between-family phenomenon--and hence are not directly related to birth order itself. The study design and analyses presented by Wichman et al. nevertheless suffer from crucial shortcomings, including their use of unfocused tests, which cause statistically significant trends to be overlooked. In addition, Wichman et al. treated birth-order effects as a linear phenomenon thereby ignoring the confluence model's prediction that these two samples may manifest opposing results based on age. This article cites between- and within-family data that demonstrate systematic birth-order effects as predicted by the confluence model. The corpus of evidence invoked here offers strong support for the assumption of the confluence model that birth-order differences in intellectual performance are primarily a within-family phenomenon.
Lou, Yu-Chiung; Lin, Chien-Heng; Chen, Chien-Min; Balderrama-Durbin, Christina; Snyder, Douglas K
2016-06-01
The current study examined the psychometric characteristics of the Chinese translation of the Marital Satisfaction Inventory-Revised (MSI-R) in a community sample of 117 couples from Taiwan. The Chinese MSI-R demonstrated moderate to strong internal consistency. Confirmatory factor analysis revealed similar scale factor structures in the Taiwanese and U.S. standardization samples. Mean profile comparisons between the current Taiwanese sample and the original MSI-R standardization sample revealed statistically significant but small differences on several subscales. Overall, the psychometric characteristics of the Chinese MSI-R lend support to its use with couples from diverse cultural backgrounds whose sole or preferred language is Chinese. It may also be appropriate to use the MSI-R in clinical settings for prevention or intervention efforts directed at Chinese-speaking couples. The implications of these findings for clinical and research purposes are discussed. © The Author(s) 2015.
Breast self-examination pamphlets: a content analysis grounded in fear appeal research.
Kline, K N; Mattson, M
2000-01-01
In this study, we used the topic of breast self-examination (BSE) to illustrate how content analysis of promotional texts (already in existence, in the process of being created, or both) can provide supplementary data to that derived from audience analysis. Specifically, we used content analysis to isolate messages in BSE pamphlets that are consistent with the variables of severity, susceptibility, response efficacy, and self-efficacy, identified by existing fear appeal research and supported by other persuasion research as critical to the construction of effective health promotion messages. We then used statistical analyses to describe the relation among these 4 message variables. Our findings suggested that BSE pamphlets contain an unbalanced proportion of threat to efficacy arguments. Additionally, the efficacy messages were substantively weak. We contrasted these messages against the relatively strong mammography arguments contained in these pamphlets. We then provided recommendations for formulating stronger persuasive arguments in BSE promotional materials.
ERIC Educational Resources Information Center
Davis, Ashley; Mirick, Rebecca G.
2015-01-01
Many social work students feel anxious when taking a statistics course. Their attitudes, beliefs, and behaviors after learning statistics are less known. However, such information could help instructors support students' ongoing development of statistical knowledge. With a sample of MSW students (N = 101) in one program, this study examined…
Magnification Bias in Gravitational Arc Statistics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Caminha, G. B.; Estrada, J.; Makler, M.
2013-08-29
The statistics of gravitational arcs in galaxy clusters is a powerful probe of cluster structure and may provide complementary cosmological constraints. Despite recent progresses, discrepancies still remain among modelling and observations of arc abundance, specially regarding the redshift distribution of strong lensing clusters. Besides, fast "semi-analytic" methods still have to incorporate the success obtained with simulations. In this paper we discuss the contribution of the magnification in gravitational arc statistics. Although lensing conserves surface brightness, the magnification increases the signal-to-noise ratio of the arcs, enhancing their detectability. We present an approach to include this and other observational effects in semi-analyticmore » calculations for arc statistics. The cross section for arc formation ({\\sigma}) is computed through a semi-analytic method based on the ratio of the eigenvalues of the magnification tensor. Using this approach we obtained the scaling of {\\sigma} with respect to the magnification, and other parameters, allowing for a fast computation of the cross section. We apply this method to evaluate the expected number of arcs per cluster using an elliptical Navarro--Frenk--White matter distribution. Our results show that the magnification has a strong effect on the arc abundance, enhancing the fraction of arcs, moving the peak of the arc fraction to higher redshifts, and softening its decrease at high redshifts. We argue that the effect of magnification should be included in arc statistics modelling and that it could help to reconcile arcs statistics predictions with the observational data.« less
A Stochastic Fractional Dynamics Model of Space-time Variability of Rain
NASA Technical Reports Server (NTRS)
Kundu, Prasun K.; Travis, James E.
2013-01-01
Rainfall varies in space and time in a highly irregular manner and is described naturally in terms of a stochastic process. A characteristic feature of rainfall statistics is that they depend strongly on the space-time scales over which rain data are averaged. A spectral model of precipitation has been developed based on a stochastic differential equation of fractional order for the point rain rate, that allows a concise description of the second moment statistics of rain at any prescribed space-time averaging scale. The model is thus capable of providing a unified description of the statistics of both radar and rain gauge data. The underlying dynamical equation can be expressed in terms of space-time derivatives of fractional orders that are adjusted together with other model parameters to fit the data. The form of the resulting spectrum gives the model adequate flexibility to capture the subtle interplay between the spatial and temporal scales of variability of rain but strongly constrains the predicted statistical behavior as a function of the averaging length and times scales. We test the model with radar and gauge data collected contemporaneously at the NASA TRMM ground validation sites located near Melbourne, Florida and in Kwajalein Atoll, Marshall Islands in the tropical Pacific. We estimate the parameters by tuning them to the second moment statistics of radar data. The model predictions are then found to fit the second moment statistics of the gauge data reasonably well without any further adjustment.
Age and experience shape developmental changes in the neural basis of language-related learning.
McNealy, Kristin; Mazziotta, John C; Dapretto, Mirella
2011-11-01
Very little is known about the neural underpinnings of language learning across the lifespan and how these might be modified by maturational and experiential factors. Building on behavioral research highlighting the importance of early word segmentation (i.e. the detection of word boundaries in continuous speech) for subsequent language learning, here we characterize developmental changes in brain activity as this process occurs online, using data collected in a mixed cross-sectional and longitudinal design. One hundred and fifty-six participants, ranging from age 5 to adulthood, underwent functional magnetic resonance imaging (fMRI) while listening to three novel streams of continuous speech, which contained either strong statistical regularities, strong statistical regularities and speech cues, or weak statistical regularities providing minimal cues to word boundaries. All age groups displayed significant signal increases over time in temporal cortices for the streams with high statistical regularities; however, we observed a significant right-to-left shift in the laterality of these learning-related increases with age. Interestingly, only the 5- to 10-year-old children displayed significant signal increases for the stream with low statistical regularities, suggesting an age-related decrease in sensitivity to more subtle statistical cues. Further, in a sample of 78 10-year-olds, we examined the impact of proficiency in a second language and level of pubertal development on learning-related signal increases, showing that the brain regions involved in language learning are influenced by both experiential and maturational factors. 2011 Blackwell Publishing Ltd.
Tsallis non-extensive statistics and solar wind plasma complexity
NASA Astrophysics Data System (ADS)
Pavlos, G. P.; Iliopoulos, A. C.; Zastenker, G. N.; Zelenyi, L. M.; Karakatsanis, L. P.; Riazantseva, M. O.; Xenakis, M. N.; Pavlos, E. G.
2015-03-01
This article presents novel results revealing non-equilibrium phase transition processes in the solar wind plasma during a strong shock event, which took place on 26th September 2011. Solar wind plasma is a typical case of stochastic spatiotemporal distribution of physical state variables such as force fields (B → , E →) and matter fields (particle and current densities or bulk plasma distributions). This study shows clearly the non-extensive and non-Gaussian character of the solar wind plasma and the existence of multi-scale strong correlations from the microscopic to the macroscopic level. It also underlines the inefficiency of classical magneto-hydro-dynamic (MHD) or plasma statistical theories, based on the classical central limit theorem (CLT), to explain the complexity of the solar wind dynamics, since these theories include smooth and differentiable spatial-temporal functions (MHD theory) or Gaussian statistics (Boltzmann-Maxwell statistical mechanics). On the contrary, the results of this study indicate the presence of non-Gaussian non-extensive statistics with heavy tails probability distribution functions, which are related to the q-extension of CLT. Finally, the results of this study can be understood in the framework of modern theoretical concepts such as non-extensive statistical mechanics (Tsallis, 2009), fractal topology (Zelenyi and Milovanov, 2004), turbulence theory (Frisch, 1996), strange dynamics (Zaslavsky, 2002), percolation theory (Milovanov, 1997), anomalous diffusion theory and anomalous transport theory (Milovanov, 2001), fractional dynamics (Tarasov, 2013) and non-equilibrium phase transition theory (Chang, 1992).
Electricity supply efficiency and organizational growth and profitability in Lagos, Nigeria
NASA Astrophysics Data System (ADS)
Adeleke, Adedeji Tajudeen
A modern and efficient infrastructure is a basic necessity for economic development and integration into the global economy. The specific problem was the inadequate and unreliable supply of electricity to manufacturing corporations in Lagos, Nigeria. The purpose of the current quantitative correlational research study was to examine if there was a correlation between electricity supply efficiency and organizational growth and profitability in manufacturing corporations in Lagos, Nigeria. The population of the current correlational research study involved 28 out of 34 manufacturing corporations from various industrial sectors in Lagos, Nigeria, that are listed and traded on the Nigerian Stock Exchange. Spearman rho correlations were used to assess the relationships between independent variables of electricity supply efficiency levels and the dependent variables of organizational growth and profitability. The result of the correlational analysis of the data revealed that there was a statistically significant, strong positive correlation between the Average Gross Income (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.57; p = 0.002. A statistically significant, strong positive correlation was found between the Average Balance Sheet Size (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.54; p = 0.003. A statistically significant, strong positive correlation between the Average Profit After Tax (1998-2007) and Average Actual Electricity Supply Efficiency Level (1998-2007), rho = 0.60; p = 0.001, was found. No statistically significant correlation between the Average Return on Investment (1998-2007) and Average Actual Electricity supply efficiency level (1998-2007), rho = 0.19; p = 0.33, was discovered.
Generalized statistical convergence of order β for sequences of fuzzy numbers
NASA Astrophysics Data System (ADS)
Altınok, Hıfsı; Karakaş, Abdulkadir; Altın, Yavuz
2018-01-01
In the present paper, we introduce the concepts of Δm-statistical convergence of order β for sequences of fuzzy numbers and strongly Δm-summable of order β for sequences of fuzzy numbers by using a modulus function f and taking supremum on metric d for 0 < β ≤ 1 and give some inclusion relations between them.
ERIC Educational Resources Information Center
Hassad, Rossi; Coxon, APM
2007-01-01
Despite more than a decade of reform efforts, students continue to experience difficulty understanding and applying statistical concepts. The predominant focus of reform has been on content, pedagogy, technology and assessment, with little attention to instructor characteristics. However, there is strong theoretical and empirical evidence that…
The Large-Scale Structure of Semantic Networks: Statistical Analyses and a Model of Semantic Growth
ERIC Educational Resources Information Center
Steyvers, Mark; Tenenbaum, Joshua B.
2005-01-01
We present statistical analyses of the large-scale structure of 3 types of semantic networks: word associations, WordNet, and Roget's Thesaurus. We show that they have a small-world structure, characterized by sparse connectivity, short average path lengths between words, and strong local clustering. In addition, the distributions of the number of…
What Behavioral and Psychological Symptoms of Dementia Affect Caregiver Burnout?
Hiyoshi-Taniguchi, Kazuko; Becker, Carl B; Kinoshita, Ayae
2018-01-01
Patients' irritability and aggression have been linked to caregiver depression, but the behaviors that most burden caregivers are not yet definitively identified. This study examines the connection between behavioral and psychological symptoms of dementia (BPSD) and the burnout of caregivers caring for home-dwelling elders with dementia symptoms in Japan. 80 Japanese rural and urban family caregivers completed detailed questionnaires about their experiences in caring for demented family members. We statistically analyzed the results for correlations between types of dementia, Pines Burnout, and Caregiver Distress. BPSD symptom severity significantly correlated with caregiver distress. The dementia symptoms most strongly correlated with caregiver burnout were: aggression, irritability, abnormal motor behavior, and hallucinations. Among the commonest symptoms, apathy, anxiety, and depression did not seriously aggravate caregiver burnout. Caregivers displayed higher burnout facing agitation/aggression, irritability, aberrant motor behavior, and hallucinations. Caregivers' reported distress was surprisingly dissimilar to their burnout scores; patients' delusions and anxiety led to higher distress reporting but not to burnout. Advance diagnosis of BPSD symptoms should be helpful to support nurses and caregivers of dementia patients. Particular support should be considered for caregivers and nurses of patients expressing aggression, irritability, abnormal motor behavior, and hallucination.
Precise orbit determination and rapid orbit recovery supported by time synchronization
NASA Astrophysics Data System (ADS)
Guo, Rui; Zhou, JianHua; Hu, XiaoGong; Liu, Li; Tang, Bo; Li, XiaoJie; Wu, Shan
2015-06-01
In order to maintain optimal signal coverage, GNSS satellites have to experience orbital maneuvers. For China's COMPASS system, precise orbit determination (POD) as well as rapid orbit recovery after maneuvers contribute to the overall Positioning, Navigation and Timing (PNT) service performance in terms of accuracy and availability. However, strong statistical correlations between clock offsets and the radial component of a satellite's positions require long data arcs for POD to converge. We propose here a new strategy which relies on time synchronization between ground tracking stations and in-orbit satellites. By fixing satellite clock offsets measured by the satellite station two-way synchronization (SSTS) systems and receiver clock offsets, POD and orbital recovery performance can be improved significantly. Using the Satellite Laser Ranging (SLR) as orbital accuracy evaluation, we find the 4-hr recovered orbit achieves about 0.71 m residual root mean square (RMS) error of fit SLR data, the recovery time is improved from 24-hr to 4-hr compared with the conventional POD without time synchronization support. In addition, SLR evaluation shows that for 1-hr prediction, about 1.47 m accuracy is achieved with the new proposed POD strategy.
Delirium diagnosis, screening and management
Lawlor, Peter G.; Bush, Shirley H.
2014-01-01
Purpose of review Our review focuses on recent developments across many settings regarding the diagnosis, screening and management of delirium, so as to inform these aspects in the context of palliative and supportive care. Recent findings Delirium diagnostic criteria have been updated in the long-awaited Diagnostic Statistical Manual of Mental Disorders, fifth edition. Studies suggest that poor recognition of delirium relates to its clinical characteristics, inadequate interprofessional communication and lack of systematic screening. Validation studies are published for cognitive and observational tools to screen for delirium. Formal guidelines for delirium screening and management have been rigorously developed for intensive care, and may serve as a model for other settings. Given that palliative sedation is often required for the management of refractory delirium at the end of life, a version of the Richmond Agitation-Sedation Scale, modified for palliative care, has undergone preliminary validation. Summary Although formal systematic delirium screening with brief but sensitive tools is strongly advocated for patients in palliative and supportive care, it requires critical evaluation in terms of clinical outcomes, including patient comfort. Randomized controlled trials are needed to inform the development of guidelines for the management of delirium in this setting. PMID:25004177
Decoding and disrupting left midfusiform gyrus activity during word reading
Hirshorn, Elizabeth A.; Ward, Michael J.; Fiez, Julie A.; Ghuman, Avniel Singh
2016-01-01
The nature of the visual representation for words has been fiercely debated for over 150 y. We used direct brain stimulation, pre- and postsurgical behavioral measures, and intracranial electroencephalography to provide support for, and elaborate upon, the visual word form hypothesis. This hypothesis states that activity in the left midfusiform gyrus (lmFG) reflects visually organized information about words and word parts. In patients with electrodes placed directly in their lmFG, we found that disrupting lmFG activity through stimulation, and later surgical resection in one of the patients, led to impaired perception of whole words and letters. Furthermore, using machine-learning methods to analyze the electrophysiological data from these electrodes, we found that information contained in early lmFG activity was consistent with an orthographic similarity space. Finally, the lmFG contributed to at least two distinguishable stages of word processing, an early stage that reflects gist-level visual representation sensitive to orthographic statistics, and a later stage that reflects more precise representation sufficient for the individuation of orthographic word forms. These results provide strong support for the visual word form hypothesis and demonstrate that across time the lmFG is involved in multiple stages of orthographic representation. PMID:27325763
Depression and substance use in a middle aged and older Puerto Rican population.
Weingartner, Katherine; Robison, Julie; Fogel, Denise; Gruman, Cynthia
2002-01-01
This study focuses on depression and substance use in Puerto Rican primary care patients, age 50 and older, recruited from five clinics in Hartford, CT (n = 303). One-third of the participants screened positive for depression using the Center for Epidemiologic Studies-Depression scale, and 16 percent either reported excessive alcohol use, prescription drug abuse, and/or illegal drug use in the past year. Correlates of depression include younger age, female gender, being separated or divorced, low perceived adequacy of income, poor health status, functional limitations, few emotional supports, and a history of an "ataque de nervios." Younger age, male gender, low perceived adequacy of income, few emotional supports, suicidal ideation, and a history of an "ataque de nervios" were associated with substance use. While the relationship between excessive alcohol use and a higher rate of depression did not reach statistical significance, drug use was a strong predictor of depression, particularly prescription drug abuse. However substance use did not significantly affect the likelihood of seeking treatment for depression. These findings underscore the need for appropriate interventions for those at risk for depression among the Puerto Rican population.
Association between a variant of the sigma-1 receptor gene and Alzheimer's disease.
Fehér, Ágnes; Juhász, Anna; László, Anna; Kálmán, János; Pákáski, Magdolna; Kálmán, János; Janka, Zoltán
2012-05-31
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with complex etiology and strong genetic predisposition. A number of investigations support the possible involvement of sigma non-opioid intracellular receptor 1 (SIGMAR1) in the pathophysiology of AD. We aimed to investigate the association between SIGMAR1 polymorphisms and late-onset AD, therefore we genotyped rs1799729 (GC-241-240TT) and rs1800866 (Q2P) in 322 Hungarian late-onset AD patients and 250 ethnically matched, elderly control individuals. The investigated polymorphisms were in nearly complete linkage disequilibrium resulting in the GC-Q and TT-P predominant haplotypes that were subjected to the statistical analyses. Our data demonstrates an association between the SIGMAR1 TT-P variant and the risk for developing AD (p=0.019), and a potential modest interaction effect (p=0.058) of the co-presence of the TT-P haplotype with apolipoprotein E4 allele on the risk for AD. Based on this mild significance, we could not fully support the hypothesis that TT-P haplotype in interaction with APOE E4 allele confers risk for developing AD. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Decoding and disrupting left midfusiform gyrus activity during word reading.
Hirshorn, Elizabeth A; Li, Yuanning; Ward, Michael J; Richardson, R Mark; Fiez, Julie A; Ghuman, Avniel Singh
2016-07-19
The nature of the visual representation for words has been fiercely debated for over 150 y. We used direct brain stimulation, pre- and postsurgical behavioral measures, and intracranial electroencephalography to provide support for, and elaborate upon, the visual word form hypothesis. This hypothesis states that activity in the left midfusiform gyrus (lmFG) reflects visually organized information about words and word parts. In patients with electrodes placed directly in their lmFG, we found that disrupting lmFG activity through stimulation, and later surgical resection in one of the patients, led to impaired perception of whole words and letters. Furthermore, using machine-learning methods to analyze the electrophysiological data from these electrodes, we found that information contained in early lmFG activity was consistent with an orthographic similarity space. Finally, the lmFG contributed to at least two distinguishable stages of word processing, an early stage that reflects gist-level visual representation sensitive to orthographic statistics, and a later stage that reflects more precise representation sufficient for the individuation of orthographic word forms. These results provide strong support for the visual word form hypothesis and demonstrate that across time the lmFG is involved in multiple stages of orthographic representation.
Work-to-Family Enrichment and Conflict Profiles: Job Characteristics and Employees' Well-Being.
Carvalho, Vânia Sofia; Chambel, Maria José
2016-10-03
This article aims to analyze work-to-family conflict (WFC) and enrichment (WFE) profiles related to job characteristics and well-being at work and general well-being. A cross-sectional survey data of 1885 employees was analyzed. The Latent Profile Analysis revealed that the five-profile solution exhibited strong statistical significance (p > .001). ANCOVAs were performed to analyze the relationship of the identified profiles with job characteristics and well-being. Employees in the Beneficial profile had the best perception of job characteristics (lowest demands and the highest control and support) and the highest well-being, and those in the Harmful profile had the lowest job characteristics perceptions and the lowest well-being. Through a comparison of the Moderate Active profile and the Moderate Harmful profile, WFE was found to buffer the effects of the WFC on well-being at work (burnout; engagement) and on general well-being (i.e., health perceptions). The promotion of WFE through higher job autonomy, job support, and fewer demands is a crucial aspect to consider. This study helps to consolidate the work-family balance typology and its effects on employees' well-being, and broadens this framework to consider job characteristics.
Code of Federal Regulations, 2011 CFR
2011-07-01
... Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.1... information identifiable to a private person obtained in a research or statistical program may only be used... reliability of federally-supported research and statistical findings by minimizing subject concern over...
Code of Federal Regulations, 2010 CFR
2010-07-01
... Administration DEPARTMENT OF JUSTICE CONFIDENTIALITY OF IDENTIFIABLE RESEARCH AND STATISTICAL INFORMATION § 22.1... information identifiable to a private person obtained in a research or statistical program may only be used... reliability of federally-supported research and statistical findings by minimizing subject concern over...
StatsCasts: screencasts for complementing lectures in statistics classes
NASA Astrophysics Data System (ADS)
Dunn, Peter K.; McDonald, Christine; Loch, Birgit
2015-05-01
Students who are studying introductory statistics units but are enrolled in non-statistics majors often struggle with the content, and do not stay engaged. Support structures are in place at many Australian universities to help these students. Most of these are face-to-face support centres that the students can visit during opening hours. To provide additional assistance to these students any time, and from anywhere, online media are increasingly used by students - either provided by support centres, or sought independently by students. Little research has been undertaken on the effectiveness of such resources to support student learning. This paper investigates whether students will embrace StatsCasts - short screen-capture videos on key statistical topics that students have struggled with in the past, with narrator explanation provided by the lecturer - as part of their learning strategy and if they will actively engage with the videos. Students enrolled in a large first-year statistics class at an Australian university who had been provided with StatsCasts responded to a survey at the end of the semester. Volunteering students also participated in a focus group to probe deeper into students' perceptions of and motivations for watching the videos. Analysis of the data shows that students do actively engage with the StatsCasts and they appear to become an important component of their study and revision strategy.
Uniform strongly interacting soliton gas in the frame of the Nonlinear Schrodinger Equation
NASA Astrophysics Data System (ADS)
Gelash, Andrey; Agafontsev, Dmitry
2017-04-01
The statistical properties of many soliton systems play the key role in the fundamental studies of integrable turbulence and extreme sea wave formation. It is well known that separated solitons are stable nonlinear coherent structures moving with constant velocity. After collisions with each other they restore the original shape and only acquire an additional phase shift. However, at the moment of strong nonlinear soliton interaction (i.e. when solitons are located close) the wave field are highly complicated and should be described by the theory of inverse scattering transform (IST), which allows to integrate the KdV equation, the NLSE and many other important nonlinear models. The usual approach of studying the dynamics and statistics of soliton wave field is based on relatively rarefied gas of solitons [1,2] or restricted by only two-soliton interactions [3]. From the other hand, the exceptional role of interacting solitons and similar coherent structures - breathers in the formation of rogue waves statistics was reported in several recent papers [4,5]. In this work we study the NLSE and use the most straightforward and general way to create many soliton initial condition - the exact N-soliton formulas obtained in the theory of the IST [6]. We propose the recursive numerical scheme for Zakharov-Mikhailov variant of the dressing method [7,8] and discuss its stability with respect to increasing the number of solitons. We show that the pivoting, i.e. the finding of an appropriate order for recursive operations, has a significant impact on the numerical accuracy. We use the developed scheme to generate statistical ensembles of 32 strongly interacting solitons, i.e. solve the inverse scattering problem for the high number of discrete eigenvalues. Then we use this ensembles as initial conditions for numerical simulations in the box with periodic boundary conditions and study statics of obtained uniform strongly interacting gas of NLSE solitons. Author thanks the support of the Russian Science Foundation (Grand No. 14-22-00174) [1] D. Dutykh, E. Pelinovsky, Numerical simulation of a solitonic gas in kdv and kdv-bbm equations, Physics Letters A 378 (42) (2014) 3102-3110. [2] E. Shurgalina, E. Pelinovsky, Nonlinear dynamics of a soliton gas: Modified korteweg-de vries equation framework, Physics Letters A 380 (24) (2016) 2049-2053. [3] E. N. Pelinovsky, E. Shurgalina, A. Sergeeva, T. G. Talipova, G. El, R. H. Grimshaw, Two-soliton interaction as an elementary act of soliton turbulence in integrable systems, Physics Letters A 377 (3) (2013) 272-275 [4] J. Soto-Crespo, N. Devine, N. Akhmediev, Integrable turbulence and rogue waves: Breathers or solitons?, Physical review letters 116 (10) (2016) 103901. [5] D. S. Agafontsev, V. E. Zakharov, Integrable turbulence and formation of rogue waves, Nonlinearity 28 (8) (2015) 2791. [6] V. E. Zakharov, A. B. Shabat, Exact theory of two-dimensional self-focusing and one-dimensional self-modulation of waves in nonlinear media, Soviet Physics JETP 34 (1) (1972) 62. [7] V. Zakharov, A. Mikhailov, Relativistically invariant two-dimensional models of field theory which are integrable by means of the inverse scattering problem method, Sov. Phys.-JETP (Engl. Transl.) 47 (6) (1978). [8] A. A. Gelash, V. E. Zakharov, Superregular solitonic solutions: a novel scenario for the nonlinear stage of modulation instability, Nonlinearity 27 (4) (2014) R1.
Dinosaurs in decline tens of millions of years before their final extinction
Sakamoto, Manabu; Benton, Michael J.; Venditti, Chris
2016-01-01
Whether dinosaurs were in a long-term decline or whether they were reigning strong right up to their final disappearance at the Cretaceous–Paleogene (K-Pg) mass extinction event 66 Mya has been debated for decades with no clear resolution. The dispute has continued unresolved because of a lack of statistical rigor and appropriate evolutionary framework. Here, for the first time to our knowledge, we apply a Bayesian phylogenetic approach to model the evolutionary dynamics of speciation and extinction through time in Mesozoic dinosaurs, properly taking account of previously ignored statistical violations. We find overwhelming support for a long-term decline across all dinosaurs and within all three dinosaurian subclades (Ornithischia, Sauropodomorpha, and Theropoda), where speciation rate slowed down through time and was ultimately exceeded by extinction rate tens of millions of years before the K-Pg boundary. The only exceptions to this general pattern are the morphologically specialized herbivores, the Hadrosauriformes and Ceratopsidae, which show rapid species proliferations throughout the Late Cretaceous instead. Our results highlight that, despite some heterogeneity in speciation dynamics, dinosaurs showed a marked reduction in their ability to replace extinct species with new ones, making them vulnerable to extinction and unable to respond quickly to and recover from the final catastrophic event. PMID:27092007
Dinosaurs in decline tens of millions of years before their final extinction.
Sakamoto, Manabu; Benton, Michael J; Venditti, Chris
2016-05-03
Whether dinosaurs were in a long-term decline or whether they were reigning strong right up to their final disappearance at the Cretaceous-Paleogene (K-Pg) mass extinction event 66 Mya has been debated for decades with no clear resolution. The dispute has continued unresolved because of a lack of statistical rigor and appropriate evolutionary framework. Here, for the first time to our knowledge, we apply a Bayesian phylogenetic approach to model the evolutionary dynamics of speciation and extinction through time in Mesozoic dinosaurs, properly taking account of previously ignored statistical violations. We find overwhelming support for a long-term decline across all dinosaurs and within all three dinosaurian subclades (Ornithischia, Sauropodomorpha, and Theropoda), where speciation rate slowed down through time and was ultimately exceeded by extinction rate tens of millions of years before the K-Pg boundary. The only exceptions to this general pattern are the morphologically specialized herbivores, the Hadrosauriformes and Ceratopsidae, which show rapid species proliferations throughout the Late Cretaceous instead. Our results highlight that, despite some heterogeneity in speciation dynamics, dinosaurs showed a marked reduction in their ability to replace extinct species with new ones, making them vulnerable to extinction and unable to respond quickly to and recover from the final catastrophic event.
[Review of meta-analysis research on exercise in South Korea].
Song, Youngshin; Gang, Moonhee; Kim, Sun Ae; Shin, In Soo
2014-10-01
The purpose of this study was to evaluate the quality of meta-analysis regarding exercise using Assessment of Multiple Systematic Reviews (AMSTAR) as well as to compare effect size according to outcomes. Electronic databases including the Korean Studies Information Service System (KISS), the National Assembly Library and the DBpia, HAKJISA and RISS4U for the dates 1990 to January 2014 were searched for 'meta-analysis' and 'exercise' in the fields of medical, nursing, physical therapy and physical exercise in Korea. AMSTAR was scored for quality assessment of the 33 articles included in the study. Data were analyzed using descriptive statistics, t-test, ANOVA and χ²-test. The mean score for AMSTAR evaluations was 4.18 (SD=1.78) and about 67% were classified at the low-quality level and 30% at the moderate-quality level. The scores of quality were statistically different by field of research, number of participants, number of databases, financial support and approval by IRB. The effect size that presented in individual studies were different by type of exercise in the applied intervention. This critical appraisal of meta-analysis published in various field that focused on exercise indicates that a guideline such as the PRISMA checklist should be strongly recommended for optimum reporting of meta-analysis across research fields.
NASA Astrophysics Data System (ADS)
Jiang, Yu; Li, Changying; Takeda, Fumiomi
2016-10-01
Currently, blueberry bruising is evaluated by either human visual/tactile inspection or firmness measurement instruments. These methods are destructive, time-consuming, and subjective. The goal of this paper was to develop a non-destructive approach for blueberry bruising detection and quantification. Experiments were conducted on 300 samples of southern highbush blueberry (Camellia, Rebel, and Star) and on 1500 samples of northern highbush blueberry (Bluecrop, Jersey, and Liberty) for hyperspectral imaging analysis, firmness measurement, and human evaluation. An algorithm was developed to automatically calculate a bruise ratio index (ratio of bruised to whole fruit area) for bruise quantification. The spectra of bruised and healthy tissues were statistically separated and the separation was independent of cultivars. Support vector machine (SVM) classification of the spectra from the regions of interest (ROIs) achieved over 94%, 92%, and 96% accuracy on the training set, independent testing set, and combined set, respectively. The statistical results showed that the bruise ratio index was equivalent to the measured firmness but better than the predicted firmness in regard to effectiveness of bruise quantification, and the bruise ratio index had a strong correlation with human assessment (R2 = 0.78 - 0.83). Therefore, the proposed approach and the bruise ratio index are effective to non-destructively detect and quantify blueberry bruising.
Jiang, Yu; Li, Changying; Takeda, Fumiomi
2016-10-21
Currently, blueberry bruising is evaluated by either human visual/tactile inspection or firmness measurement instruments. These methods are destructive, time-consuming, and subjective. The goal of this paper was to develop a non-destructive approach for blueberry bruising detection and quantification. Experiments were conducted on 300 samples of southern highbush blueberry (Camellia, Rebel, and Star) and on 1500 samples of northern highbush blueberry (Bluecrop, Jersey, and Liberty) for hyperspectral imaging analysis, firmness measurement, and human evaluation. An algorithm was developed to automatically calculate a bruise ratio index (ratio of bruised to whole fruit area) for bruise quantification. The spectra of bruised and healthy tissues were statistically separated and the separation was independent of cultivars. Support vector machine (SVM) classification of the spectra from the regions of interest (ROIs) achieved over 94%, 92%, and 96% accuracy on the training set, independent testing set, and combined set, respectively. The statistical results showed that the bruise ratio index was equivalent to the measured firmness but better than the predicted firmness in regard to effectiveness of bruise quantification, and the bruise ratio index had a strong correlation with human assessment (R2 = 0.78 - 0.83). Therefore, the proposed approach and the bruise ratio index are effective to non-destructively detect and quantify blueberry bruising.
Cost-effectiveness of pre-participation screening of athletes with ECG in Europe and Algeria.
Assanelli, Deodato; Levaggi, Rosella; Carré, François; Sharma, Sanjay; Deligiannis, Asterios; Mellwig, Klaus Peter; Tahmi, Mohamed; Vinetti, Giovanni; Aliverti, Paola
2015-03-01
The aim of this study is to evaluate the cost-effectiveness of ECG in combination with family and personal history and physical examination in order to detect cardiovascular diseases that might cause sudden death in athletes. The study was conducted on a cohort of 6,634, mainly young professional and recreational athletes, 1,071 from Algeria and 5,563 from Europe (France, Germany and Greece). Each athlete underwent medical history, physical examination, and resting 12-lead ECG. 293 athletes (4.4 %), 149 in Europe (2.7 %) and 144 in Algeria (13.4 %) required further tests, and 56 were diagnosed with cardiovascular disease and thus disqualified. The cost-effectiveness ratio (CER) was calculated as the ratio between the cost of screening and the number of statistical life-years saved by the intervention. The estimated reduced risk of death deriving from treatment or disqualification resulted in the saving of 79.1 statistical life-years in Europe and 136.3 in Algeria. CER of screening was 4,071 purchasing-power-parity-adjusted US dollars ($PPP) in Europe and 582 $PPP in Algeria. The results of this study strongly support the utilisation of 12-lead ECG in the pre-participation screening of young athletes, especially in countries where secondary preventive care is not highly developed.
Dinosaurs in decline tens of millions of years before their final extinction
NASA Astrophysics Data System (ADS)
Sakamoto, Manabu; Benton, Michael J.
2016-05-01
Whether dinosaurs were in a long-term decline or whether they were reigning strong right up to their final disappearance at the Cretaceous-Paleogene (K-Pg) mass extinction event 66 Mya has been debated for decades with no clear resolution. The dispute has continued unresolved because of a lack of statistical rigor and appropriate evolutionary framework. Here, for the first time to our knowledge, we apply a Bayesian phylogenetic approach to model the evolutionary dynamics of speciation and extinction through time in Mesozoic dinosaurs, properly taking account of previously ignored statistical violations. We find overwhelming support for a long-term decline across all dinosaurs and within all three dinosaurian subclades (Ornithischia, Sauropodomorpha, and Theropoda), where speciation rate slowed down through time and was ultimately exceeded by extinction rate tens of millions of years before the K-Pg boundary. The only exceptions to this general pattern are the morphologically specialized herbivores, the Hadrosauriformes and Ceratopsidae, which show rapid species proliferations throughout the Late Cretaceous instead. Our results highlight that, despite some heterogeneity in speciation dynamics, dinosaurs showed a marked reduction in their ability to replace extinct species with new ones, making them vulnerable to extinction and unable to respond quickly to and recover from the final catastrophic event.
Impact of some low-cost interventions on students' performance in a Nigerian medical school.
Anyaehie, U B; Okeke, T; Nwagha, U; Orizu, I; Iyare, E; Dim, C; Okafor, C
2014-01-01
Students' poor performance in physiology examinations has been worrisome to the university community. Reported preference of peer-tutoring to didactic lectures at the University of Nigeria Medical School has not been investigated. The aim of this work is to design/implement low-cost interventions to improve teaching and learning of physiology. This is a postintervention retrospective review of medical Student's performance in 2 nd Bachelor of Medicine and Bachelor of Surgery examinations physiology. Data were collected and analyzed by descriptive and inferential statistics using the MedCalc Statistical software (Turkey). The odds ratio (OR) was used to determine the chances of passing before and after the intervention. The level of significance was set at P < 0.05. A total of 2152 students sat for the professional examination over the study period, and 1485 students passed the examination at first attempt giving an overall pass rate of 69%. The pass rate from 2008 when our interventions started was significantly higher than the pass rate before this reform (OR: 0.53; 95% confidence interval: 0.43-0.64; P < 0.0001). Results support the engagement of teachers with strong translational interests and clinicians to augment existing faculty in basic sciences, innovative alternatives to passive lecture formats and students involvement in program evaluation.
Unifying quantum heat transfer in a nonequilibrium spin-boson model with full counting statistics
NASA Astrophysics Data System (ADS)
Wang, Chen; Ren, Jie; Cao, Jianshu
2017-02-01
To study the full counting statistics of quantum heat transfer in a driven nonequilibrium spin-boson model, we develop a generalized nonequilibrium polaron-transformed Redfield equation with an auxiliary counting field. This enables us to study the impact of qubit-bath coupling ranging from weak to strong regimes. Without external modulations, we observe maximal values of both steady-state heat flux and noise power in moderate coupling regimes, below which we find that these two transport quantities are enhanced by the finite-qubit-energy bias. With external modulations, the geometric-phase-induced heat flux shows a monotonic decrease upon increasing the qubit-bath coupling at zero qubit energy bias (without bias). While under the finite-qubit-energy bias (with bias), the geometric-phase-induced heat flux exhibits an interesting reversal behavior in the strong coupling regime. Our results unify the seemingly contradictory results in weak and strong qubit-bath coupling regimes and provide detailed dissections for the quantum fluctuation of nonequilibrium heat transfer.
France, Stacey; Bown, Jenna; Nowosilskyj, Matthew; Mott, Megan; Rand, Stephanie; Walters, Julie
2014-10-01
There is good evidence in the literature supporting physiotherapy in the management of some forms of headache. Dry needling of myofascial trigger points is becoming an increasingly common approach despite a paucity of research evidence supporting its use. The purpose of this review was to determine the evidence supporting the use of dry needling in addition to conventional physiotherapy in the management of tension-type and cervicogenic headache. Ten databases were searched for evidence of the effect of dry needling on the severity and frequency of tension and cervicogenic headache based ICHD classifications. Three relevant studies were identified and all three showed statistically significant improvements following dry needling, but no significant differences between groups. Only one study reported on headache frequency or intensity, reporting a 45 mm improvement in VAS score following the addition of dry needling to conventional physiotherapy. Two studies showed significant improvements with dry needling over 4-5 weeks of treatment. No adverse events were reported. The literature suggests that while there is insufficient evidence to strongly advocate for the use of dry needling, it may be a useful addition to conventional physiotherapy in headache management. Further research with a stronger methodological design is required. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.
A study of the effects of strong magnetic fields on the image resolution of PET scanners
NASA Astrophysics Data System (ADS)
Burdette, Don J.
Very high resolution images can be achieved in small animal PET systems utilizing solid state silicon pad detectors. In such systems using detectors with sub-millimeter intrinsic resolutions, the range of the positron is the largest contribution to the image blur. The size of the positron range effect depends on the initial positron energy and hence the radioactive tracer used. For higher energy positron emitters, such as 68Ga and 94mTc, the variation of the annihilation point dominates the spatial resolution. In this study two techniques are investigated to improve the image resolution of PET scanners limited by the range of the positron. One, the positron range can be reduced by embedding the PET field of view in a strong magnetic field. We have developed a silicon pad detector based PET instrument that can operate in strong magnetic fields with an image resolution of 0.7 mm FWHM to study this effect. Two, iterative reconstruction methods can be used to statistically correct for the range of the positron. Both strong magnetic fields and iterative reconstruction algorithms that statistically account for the positron range distribution are investigated in this work.
The Development of Statistics Textbook Supported with ICT and Portfolio-Based Assessment
NASA Astrophysics Data System (ADS)
Hendikawati, Putriaji; Yuni Arini, Florentina
2016-02-01
This research was development research that aimed to develop and produce a Statistics textbook model that supported with information and communication technology (ICT) and Portfolio-Based Assessment. This book was designed for students of mathematics at the college to improve students’ ability in mathematical connection and communication. There were three stages in this research i.e. define, design, and develop. The textbooks consisted of 10 chapters which each chapter contains introduction, core materials and include examples and exercises. The textbook developed phase begins with the early stages of designed the book (draft 1) which then validated by experts. Revision of draft 1 produced draft 2 which then limited test for readability test book. Furthermore, revision of draft 2 produced textbook draft 3 which simulated on a small sample to produce a valid model textbook. The data were analysed with descriptive statistics. The analysis showed that the Statistics textbook model that supported with ICT and Portfolio-Based Assessment valid and fill up the criteria of practicality.
Exposure to tobacco marketing and support for tobacco control policies.
Hammond, David; Costello, Mary-Jean; Fong, Geoffrey T; Topham, Jennifer
2006-01-01
To examine the salience of tobacco marketing on postsecondary campuses and student support for tobacco control policies. Face-to-face surveys were conducted with 1690 students at 3 universities in southwestern Ontario. Virtually all (97%) students reported noticing tobacco marketing in the past year, and 35% reported noticing marketing on campus. There was strong support for smoke-free restrictions on campus, including restaurants and bars (82%), and for prohibitions on campus marketing. The presence of campus policies was associated with reduced exposure to marketing and increased policy support. There is strong support among students to remove tobacco marketing from campus and to introduce comprehensive smoke-free restrictions.
ERIC Educational Resources Information Center
Dickinson, David K.; McCabe, Allyssa
2001-01-01
Data from three studies investigating factors supporting literacy development of children from low-income families indicate: early levels of achievement are strongly linked to later success; kindergarten vocabulary is strongly reflective of the use of varied vocabulary during meal times; and teacher training in literacy is beneficial to classroom…
Metz, Anneke M
2008-01-01
There is an increasing need for students in the biological sciences to build a strong foundation in quantitative approaches to data analyses. Although most science, engineering, and math field majors are required to take at least one statistics course, statistical analysis is poorly integrated into undergraduate biology course work, particularly at the lower-division level. Elements of statistics were incorporated into an introductory biology course, including a review of statistics concepts and opportunity for students to perform statistical analysis in a biological context. Learning gains were measured with an 11-item statistics learning survey instrument developed for the course. Students showed a statistically significant 25% (p < 0.005) increase in statistics knowledge after completing introductory biology. Students improved their scores on the survey after completing introductory biology, even if they had previously completed an introductory statistics course (9%, improvement p < 0.005). Students retested 1 yr after completing introductory biology showed no loss of their statistics knowledge as measured by this instrument, suggesting that the use of statistics in biology course work may aid long-term retention of statistics knowledge. No statistically significant differences in learning were detected between male and female students in the study.
Subar, Amy F.; Crafts, Jennifer; Zimmerman, Thea Palmer; Wilson, Michael; Mittl, Beth; Islam, Noemi G.; Mcnutt, Suzanne; Potischman, Nancy; Buday, Richard; Hull, Stephen G.; Baranowski, Tom; Guenther, Patricia M.; Willis, Gordon; Tapia, Ramsey; Thompson, Frances E.
2013-01-01
Objective To assess the accuracy of portion-size estimates and participant preferences using various presentations of digital images. Design Two observational feeding studies were conducted. In both, each participant selected and consumed foods for breakfast and lunch, buffet style, serving themselves portions of nine foods representing five forms (eg, amorphous, pieces). Serving containers were weighed unobtrusively before and after selection as was plate waste. The next day, participants used a computer software program to select photographs representing portion sizes of foods consumed the previous day. Preference information was also collected. In Study 1 (n=29), participants were presented with four different types of images (aerial photographs, angled photographs, images of mounds, and household measures) and two types of screen presentations (simultaneous images vs an empty plate that filled with images of food portions when clicked). In Study 2 (n=20), images were presented in two ways that varied by size (large vs small) and number (4 vs 8). Subjects/setting Convenience sample of volunteers of varying background in an office setting. Statistical analyses performed Repeated-measures analysis of variance of absolute differences between actual and reported portions sizes by presentation methods. Results Accuracy results were largely not statistically significant, indicating that no one image type was most accurate. Accuracy results indicated the use of eight vs four images was more accurate. Strong participant preferences supported presenting simultaneous vs sequential images. Conclusions These findings support the use of aerial photographs in the automated self-administered 24-hour recall. For some food forms, images of mounds or household measures are as accurate as images of food and, therefore, are a cost-effective alternative to photographs of foods. PMID:20102828
Alignment of practice guidelines with targeted-therapy drug funding policies in Ontario.
Ramjeesingh, R; Meyer, R M; Brouwers, M; Chen, B E; Booth, C M
2013-02-01
We evaluated clinical practice guideline (cpg) recommendations from Cancer Care Ontario's Program in Evidence-Based Care (pebc) for molecularly targeted systemic treatments (tts) and subsequent funding decisions from the Ontario Ministry of Health and Long-Term Care. We identified pebc cpgs on tt published before June 1, 2010, and extracted information regarding the key evidence cited in support of cpg recommendations and the effect size associated with each tt. Those variables were compared with mohltc funding decisions as of June 2011. From 23 guidelines related to 17 tts, we identified 43 recommendations, among which 38 (88%) endorsed tt use. Among all the recommendations, 38 (88%) were based on published key evidence, with 82% (31 of 38) being supported by meta-analyses or phase iii trials. For the 38 recommendations endorsing tts, funding was approved in 28 (74%; odds ratio related to cpg recommendation: 29.9; p = 0.003). We were unable to demonstrate that recommendations associated with statistically significant improvements in overall survival [os: 14 of 16 (88%) vs. 8 of 14 (57%); p = 0.10] or disease- (dfs) or progression-free survival [pfs: 16 of 21 (76%) vs. 3 of 5 (60%); p = 0.59] were more likely to be funded than those with no significant difference. Moreover, we did not observe significant associations between funding approvals and absolute improvements of 3 months or more in os [6 of 6 (100%) vs. 3 of 6 (50%), p = 0.18] or pfs [6 of 8 (75%) vs. 10 of 12 (83%), p = 1.00]. For use of tts, most recommendations in pebc cpgs are based on meta-analyses or phase iii data, and funding decisions were strongly associated with those recommendations. Our data suggest a trend toward increased rates of funding for therapies with statistically significant improvements in os.
Martinez-Lozano Sinues, Pablo; Landoni, Elena; Miceli, Rosalba; Dibari, Vincenza F; Dugo, Matteo; Agresti, Roberto; Tagliabue, Elda; Cristoni, Simone; Orlandi, Rosaria
2015-09-21
Breath analysis represents a new frontier in medical diagnosis and a powerful tool for cancer biomarker discovery due to the recent development of analytical platforms for the detection and identification of human exhaled volatile compounds. Statistical and bioinformatic tools may represent an effective complement to the technical and instrumental enhancements needed to fully exploit clinical applications of breath analysis. Our exploratory study in a cohort of 14 breast cancer patients and 11 healthy volunteers used secondary electrospray ionization-mass spectrometry (SESI-MS) to detect a cancer-related volatile profile. SESI-MS full-scan spectra were acquired in a range of 40-350 mass-to-charge ratio (m/z), converted to matrix data and analyzed using a procedure integrating data pre-processing for quality control, and a two-step class prediction based on machine-learning techniques, including a robust feature selection, and a classifier development with internal validation. MS spectra from exhaled breath showed an individual-specific breath profile and high reciprocal homogeneity among samples, with strong agreement among technical replicates, suggesting a robust responsiveness of SESI-MS. Supervised analysis of breath data identified a support vector machine (SVM) model including 8 features corresponding to m/z 106, 126, 147, 78, 148, 52, 128, 315 and able to discriminate exhaled breath from breast cancer patients from that of healthy individuals, with sensitivity and specificity above 0.9.Our data highlight the significance of SESI-MS as an analytical technique for clinical studies of breath analysis and provide evidence that our noninvasive strategy detects volatile signatures that may support existing technologies to diagnose breast cancer.
NASA Technical Reports Server (NTRS)
Bonavito, N. L.; Gordon, C. L.; Inguva, R.; Serafino, G. N.; Barnes, R. A.
1994-01-01
NASA's Mission to Planet Earth (MTPE) will address important interdisciplinary and environmental issues such as global warming, ozone depletion, deforestation, acid rain, and the like with its long term satellite observations of the Earth and with its comprehensive Data and Information System. Extensive sets of satellite observations supporting MTPE will be provided by the Earth Observing System (EOS), while more specific process related observations will be provided by smaller Earth Probes. MTPE will use data from ground and airborne scientific investigations to supplement and validate the global observations obtained from satellite imagery, while the EOS satellites will support interdisciplinary research and model development. This is important for understanding the processes that control the global environment and for improving the prediction of events. In this paper we illustrate the potential for powerful artificial intelligence (AI) techniques when used in the analysis of the formidable problems that exist in the NASA Earth Science programs and of those to be encountered in the future MTPE and EOS programs. These techniques, based on the logical and probabilistic reasoning aspects of plausible inference, strongly emphasize the synergetic relation between data and information. As such, they are ideally suited for the analysis of the massive data streams to be provided by both MTPE and EOS. To demonstrate this, we address both the satellite imagery and model enhancement issues for the problem of ozone profile retrieval through a method based on plausible scientific inferencing. Since in the retrieval problem, the atmospheric ozone profile that is consistent with a given set of measured radiances may not be unique, an optimum statistical method is used to estimate a 'best' profile solution from the radiances and from additional a priori information.
Developing and validating a measure of community capacity: Why volunteers make the best neighbours.
Lovell, Sarah A; Gray, Andrew R; Boucher, Sara E
2015-05-01
Social support and community connectedness are key determinants of both mental and physical wellbeing. While social capital has been used to indicate the instrumental value of these social relationships, its broad and often competing definitions have hindered practical applications of the concept. Within the health promotion field, the related concept of community capacity, the ability of a group to identify and act on problems, has gained prominence (Labonte and Laverack, 2001). The goal of this study was to develop and validate a scale measuring community capacity including exploring its associations with socio-demographic and civic behaviour variables among the residents of four small (populations 1500-2000) high-deprivation towns in southern New Zealand. The full (41-item) scale was found to have strong internal consistency (Cronbach's alpha = 0.89) but a process of reducing the scale resulted in a shorter 26-item instrument with similar internal consistency (alpha 0.88). Subscales of the reduced instrument displayed at least marginally acceptable levels of internal consistency (0.62-0.77). Using linear regression models, differences in community capacity scores were found for selected criterion, namely time spent living in the location, local voting, and volunteering behaviour, although the first of these was no longer statistically significant in an adjusted model with potential confounders including age, sex, ethnicity, education, marital status, employment, household income, and religious beliefs. This provides support for the scale's concurrent validity. Differences were present between the four towns in unadjusted models and remained statistically significant in adjusted models (including variables mentioned above) suggesting, crucially, that even when such factors are accounted for, perceptions of one's community may still depend on place. Copyright © 2014. Published by Elsevier Ltd.
Hasin, Deborah; Hatzenbuehler, Mark L; Keyes, Katherine; Ogburn, Elizabeth
2006-09-01
Two major nomenclatures, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and International Classification of Diseases, tenth edition (ICD-10), currently define substance use disorders for broad audiences of users with different training, experience and interests. A comparison of these definitions and their implications for DSM-V and ICD-11 has not been available. The background for the dependence concept and abuse, harmful use, withdrawal, substance-induced disorders and remission and other substance-related conditions is reviewed. Reliability evidence is presented, as is validity evidence from approaches including psychometric, genetic and animal studies. The relevance of the DSM-IV and ICD-10 compared to alternative systems (e.g. the Addiction Severity Index) is considered. Reliability and psychometric validity evidence for substance dependence is consistently strong, but more mixed for abuse and harmful use. Findings on the genetics of alcohol disorders support the validity of the dependence concept, while animal studies underscore the centrality of continued use despite negative consequences to the concept of dependence. While few studies on substance-induced disorders have been conducted, those published show good reliability and validity when elements of DSM-IV and ICD-10 are combined. Dependence in DSM-V and ICD-11 should be retained, standardizing both criteria sets and adding a severity measure. The consequences of heavy use should be measured independently of dependence; add cannabis withdrawal if further research supports existing evidence; conduct further studies of the substance-induced psychiatric categories; standardize their criteria across DSM-V and ICD-11; develop a theoretical basis for better remission criteria; consider changing substance 'abuse' to substance 'dysfunction disorder'; and conduct clinician education on the value of the diagnostic criteria.
NASA Astrophysics Data System (ADS)
Aller, M. F.; Aller, H. D.; Hughes, P. A.
2001-12-01
Using centimeter-band total flux and linear polarization observations of the Pearson-Readhead sample sources systematically obtained with the UMRAO 26-m radio telescope during the past 16 years, we identify the range of variability properties and their temporal changes as functions of both optical and radio morphological classification. We find that our earlier statistical analysis, based on a time window of 6.4 years, did not delineate the full amplitude range of the total flux variability; further, several galaxies exhibit longterm, systematic changes or rather infrequent outbursts requiring long term observations for detection. Using radio classification as a delineator, we confirm, and find additional evidence, that significant changes in flux density can occur in steep spectrum and lobe-dominated objects as well as in compact, flat-spectrum objects. We find that statistically the time-averaged total flux density spectra steepen when longer time windows are included, which we attribute to a selection effect in the source sample. We have identified preferred orientations of the electric vector of the polarized emission (EVPA) in an unbiased manner in several sources, including several QSOs which have exhibited large variations in total flux while maintaining stable EVPAs, and compared these with orientations of the flow direction indicated by VLB morphology. We have looked for systematic, monotonic changes in EVPA which might be expected in the emission from a precessing jet, but none were identified. A Scargle periodogram analysis found no strong evidence for periodicity in any of the sample sources. We thank the NSF for grants AST-8815678, AST-9120224, AST-9421979, and AST-9900723 which provided partial support for this research. The operation of the 26-meter telescope is supported by the University of Michigan Department of Astronomy.
Patient Satisfaction With Pharmacist-Led Chronic Disease State Management Programs.
Schuessler, Tyler J; Ruisinger, Janelle F; Hare, Sarah E; Prohaska, Emily S; Melton, Brittany L
2016-10-01
To assess patient satisfaction, perception of self-management, and perception of disease state knowledge with pharmacist-led diabetes and cardiovascular disease state management (DSM) programs. A self-insured chain of grocery store pharmacies in the Kansas City metropolitan area administers pharmacist-led diabetes and cardiovascular DSM programs for eligible employees and dependents. A modified version of the Diabetes Disease State Management Questionnaire was used to assess patient satisfaction with the DSM programs. Demographic information was also collected. Survey items were based on a 5-point Likert scale (1 = strongly disagree and 5 = strongly agree). Patients were eligible to complete the survey if he or she had been in at least 1 DSM program for 6 months. Data were assessed using descriptive statistics and analysis of variance. Across 20 pharmacies, 281 eligible participants were identified, and 46% (n = 128) completed a survey. Means for summed items relating to overall satisfaction (8 items), self-management (5 items), and knowledge (4 items) were 36.6/40 (standard deviation [SD] = 3.9), 20.9/25 (SD = 3.4), and 17.6/20 (SD = 2.1), respectively. Participant comments further indicated that the program and pharmacists are helpful and increase motivation and accountability. Positive patient responses to the program support use of pharmacist-led DSM programs. © The Author(s) 2015.
Disentangling weak and strong interactions in B→ K^{*}(→ Kπ )π Dalitz-plot analyses
NASA Astrophysics Data System (ADS)
Charles, Jérôme; Descotes-Genon, Sébastien; Ocariz, José; Pérez Pérez, Alejandro
2017-08-01
Dalitz-plot analyses of B→ Kπ π decays provide direct access to decay amplitudes, and thereby weak and strong phases can be disentangled by resolving the interference patterns in phase space between intermediate resonant states. A phenomenological isospin analysis of B→ K^*(→ Kπ )π decay amplitudes is presented exploiting available amplitude analyses performed at the BaBar, Belle and LHCb experiments. A first application consists in constraining the CKM parameters thanks to an external hadronic input. A method, proposed some time ago by two different groups and relying on a bound on the electroweak penguin contribution, is shown to lack the desired robustness and accuracy, and we propose a more alluring alternative using a bound on the annihilation contribution. A second application consists in extracting information on hadronic amplitudes assuming the values of the CKM parameters from a global fit to quark flavour data. The current data yields several solutions, which do not fully support the hierarchy of hadronic amplitudes usually expected from theoretical arguments (colour suppression, suppression of electroweak penguins), as illustrated from computations within QCD factorisation. Some prospects concerning the impact of future measurements at LHCb and Belle II are also presented. Results are obtained with the CKMfitter analysis package, featuring the frequentist statistical approach and using the Rfit scheme to handle theoretical uncertainties.
Colorful Investigations of Supernovae for WFIRST-AFTA
NASA Astrophysics Data System (ADS)
Foley, Ryan
Type Ia supernovae (SNe Ia) are extremely good probes of dark energy, and WFIRST-AFTA is particularly well suited to make the best SN distance measurements possible. For conservative assumptions, the WFIRST SN survey is projected to have twice the impact as its other probes. Considering that Euclid will only have a minimal SN survey, but strong programs for other dark energy probes, the WFIRST SN survey is especially unique and important. With an initial simulation of the WFIRST-AFTA survey, we have determined that the largest statistical and systematic uncertainties are related to SN color. SN distances strongly depend on the precise measurement of SN colors since we must make a dust extinction correction that depends on the observed color. The details of how the correction is applied and the possibility that the correction evolves with redshift combine with potential calibration systematics to limit the current effectiveness of the SN component of WFIRST-AFTA. Here, we propose to support two graduate students to (1) investigate how intrinsic color variations will impact WFIRST-AFTA systematic uncertainties, (2) determine improved methods for reducing the systematic uncertainties related to SN color, and (3) simulate survey strategies incorporating our results to obtain the highest dark energy figure of merit (DE-FoM).
Lammer, E; Carr, G J; Wendler, K; Rawlings, J M; Belanger, S E; Braunbeck, Th
2009-03-01
The fish acute toxicity test is a mandatory component in the base set of data requirements for ecotoxicity testing. The fish acute toxicity test is not compatible with most current animal welfare legislation because mortality is the primary endpoint and it is often hypothesized that fish suffer distress and perhaps pain. Animal alternative considerations have also been incorporated into new European REACH regulations through strong advocacy for the reduction of testing with live animals. One of the most promising alternative approaches to classical acute fish toxicity testing with live fish is the fish embryo toxicity (FET) test. The FET has been a mandatory component in routine whole effluent testing in Germany since 2005 and has already been standardized at the international level. In order to analyze the applicability of the FET also in chemical testing, a comparative re-evaluation of both fish and fish embryo toxicity data was carried out for a total of 143 substances, and statistical approaches were developed to evaluate the correlation between fish and fish embryo toxicity data. Results confirm that fish embryo tests are neither better nor worse than acute fish toxicity tests and provide strong scientific support for the FET as a surrogate for the acute fish toxicity test.
Index insurance for pro-poor conservation of hornbills in Thailand.
Chantarat, Sommarat; Barrett, Christopher B; Janvilisri, Tavan; Mudsri, Sittichai; Niratisayakul, Chularat; Poonswad, Pilai
2011-08-23
This study explores the potential of index insurance as a mechanism to finance community-based biodiversity conservation in areas where a strong correlation exists between natural disaster risk, keystone species populations, and the well-being of the local population. We illustrate this potential using the case of hornbill conservation in the Budo-Sungai Padi rainforests of southern Thailand, using 16-y hornbill reproduction data and 5-y household expenditures data reflecting local economic well-being. We show that severe windstorms cause both lower household expenditures and critical nest tree losses that directly constrain nesting capacity and so reduce the number of hornbill chicks recruited in the following breeding season. Forest residents' coping strategies further disturb hornbills and their forest habitats, compounding windstorms' adverse effects on hornbills' recruitment in the following year. The strong statistical relationship between wind speed and both hornbill nest tree losses and household expenditures opens up an opportunity to design wind-based index insurance contracts that could both enhance hornbill conservation and support disaster-affected households in the region. We demonstrate how such contracts could be written and operationalized and then use simulations to show the significant promise of unique insurance-based approaches to address weather-related risk that threatens both biodiversity and poor populations.
Index insurance for pro-poor conservation of hornbills in Thailand
Chantarat, Sommarat; Barrett, Christopher B.; Janvilisri, Tavan; Mudsri, Sittichai; Niratisayakul, Chularat
2011-01-01
This study explores the potential of index insurance as a mechanism to finance community-based biodiversity conservation in areas where a strong correlation exists between natural disaster risk, keystone species populations, and the well-being of the local population. We illustrate this potential using the case of hornbill conservation in the Budo-Sungai Padi rainforests of southern Thailand, using 16-y hornbill reproduction data and 5-y household expenditures data reflecting local economic well-being. We show that severe windstorms cause both lower household expenditures and critical nest tree losses that directly constrain nesting capacity and so reduce the number of hornbill chicks recruited in the following breeding season. Forest residents’ coping strategies further disturb hornbills and their forest habitats, compounding windstorms’ adverse effects on hornbills’ recruitment in the following year. The strong statistical relationship between wind speed and both hornbill nest tree losses and household expenditures opens up an opportunity to design wind-based index insurance contracts that could both enhance hornbill conservation and support disaster-affected households in the region. We demonstrate how such contracts could be written and operationalized and then use simulations to show the significant promise of unique insurance-based approaches to address weather-related risk that threatens both biodiversity and poor populations. PMID:21873183
Mangin, B; Thoquet, P; Olivier, J; Grimsley, N H
1999-03-01
Ralstonia solanacearum is a soil-borne bacterium that causes the serious disease known as bacterial wilt in many plant species. In tomato, several QTL controlling resistance have been found, but in different studies, markers spanning a large region of chromosome 6 showed strong association with the resistance. By using two different approaches to analyze the data from a field test F3 population, we show that at least two separate loci approximately 30 cM apart on this chromosome are most likely involved in the resistance. First, a temporal analysis of the progression of symptoms reveals a distal locus early in the development of the disease. As the disease progresses, the maximum LOD peak observed shifts toward the proximal end of the chromosome, obscuring the distal locus. Second, although classical interval mapping could only detect the presence of one locus, a statistical "two-QTL model" test, specifically adapted for the resolution of linked QTL, strongly supported the hypothesis for the presence of two loci. These results are discussed in the context of current molecular knowledge about disease resistance genes on chromosome 6 and observations made by tomato breeders during the production of bacterial wilt-resistant varieties.
Mangin, B; Thoquet, P; Olivier, J; Grimsley, N H
1999-01-01
Ralstonia solanacearum is a soil-borne bacterium that causes the serious disease known as bacterial wilt in many plant species. In tomato, several QTL controlling resistance have been found, but in different studies, markers spanning a large region of chromosome 6 showed strong association with the resistance. By using two different approaches to analyze the data from a field test F3 population, we show that at least two separate loci approximately 30 cM apart on this chromosome are most likely involved in the resistance. First, a temporal analysis of the progression of symptoms reveals a distal locus early in the development of the disease. As the disease progresses, the maximum LOD peak observed shifts toward the proximal end of the chromosome, obscuring the distal locus. Second, although classical interval mapping could only detect the presence of one locus, a statistical "two-QTL model" test, specifically adapted for the resolution of linked QTL, strongly supported the hypothesis for the presence of two loci. These results are discussed in the context of current molecular knowledge about disease resistance genes on chromosome 6 and observations made by tomato breeders during the production of bacterial wilt-resistant varieties. PMID:10049932
DOE Office of Scientific and Technical Information (OSTI.GOV)
Han, Chang Wan; Choksi, Tej; Milligan, Cory
The strength of metal-support bonding in heterogeneous catalysts determines their thermal stability, therefore, a tremendous amount of effort has been expended to understand metal-support interactions. Herein, we report the discovery of an anomalous “strong metal-support bonding” between gold nanoparticles and “nano-engineered” Fe 3O 4 substrates by in-situ microscopy. During in-situ vacuum annealing of Au-Fe 3O 4 dumbbell-like nanoparticles, synthesized by the epitaxial growth of nano-Fe 3O 4 on Au nanoparticles, the gold nanoparticles transform into the monolayered gold thinfilms and wet the surface of nano-Fe 3O 4, as the surface reduction of nano-Fe 3O 4 proceeds. This phenomenon results frommore » a unique coupling of the size-and shape-dependent high surface reducibility of nano-Fe 3O 4 and the extremely strong adhesion between Au and the reduced Fe 3O 4. This strong-metal support bonding reveals the significance of controlling the metal oxide support size and morphology for optimizing metal-support bonding and, ultimately, for the development of improved catalysts and functional nanostructures.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pulliam, L.W.
The purpose of this descriptive, correlational study was to ascertain if there is a relationship between social support and the nutritional status of patients receiving radiation therapy for cancer. The data collection instruments used included the Norbeck Social Support Questionnaire (NSSQ), the Personal Characteristics Form, the abbreviated Health History, the Flow Sheet for Nutritional Data, and the Interview Schedule. For the analysis of data descriptive statistics were utilized to provide a profile of subjects, and correlational statistics were used to ascertain if there were relationships among the indicators of nutritional status and the social support variables. A convenience sample wasmore » comprised of 50 cancer patients deemed curable by radiation therapy. Findings included significant decreases in anthropometric measurements and biochemical tests during therapy. Serial assessments of nutritional status, therefore, are recommended for all cancer patients during therapy in order to plan and implement strategies for meeting the self-care requisites for food and water. No statistically significant relationships were found between the social support variables as measured by the NSSQ and the indicators of nutritional status. This suggests that nurses can assist patients by fostering support from actual and potential nutritional confidants.« less
Gain statistics of a fiber optical parametric amplifier with a temporally incoherent pump.
Xu, Y Q; Murdoch, S G
2010-03-15
We present an investigation of the statistics of the gain fluctuations of a fiber optical parametric amplifier pumped with a temporally incoherent pump. We derive a simple expression for the probability distribution of the gain of the amplified optical signal. The gain statistics are shown to be a strong function of the signal detuning and allow the possibility of generating optical gain distributions with controllable long-tails. Very good agreement is found between this theory and the experimentally measured gain distributions of an incoherently pumped amplifier.
NASA Astrophysics Data System (ADS)
Wainger, Lisa; Yu, Hao; Gazenski, Kim; Boynton, Walter
2016-09-01
A major question in restoring estuarine water quality is whether local actions to manage excess nutrients can be effective, given that estuaries are also responding to tidal inputs from adjacent water bodies. Several types of statistical analysis were used to examine spatially-detailed and long-term water quality monitoring data in eight sub-estuaries of Chesapeake Bay. These sub-estuaries are likely to be similar to other shallow systems with moderate to long water residence times. Statistical cluster analysis of spatial water quality data suggested that estuaries had spatially distinct water quality zones and that the peak algal biomass (as measured by chlorophyll-a) was most often controlled by local watershed inputs in all but one estuary, although mainstem inputs affected most estuaries at some times and places. An elasticity indicator that compared inter-annual changes in sub-estuaries to parallel changes in the mainstem Chesapeake Bay supported the idea that water quality in sub-estuaries was not strongly coupled to the mainstem. A cross-channel zonation of water quality observed near the mouth of estuaries suggested that Bay influences were stronger on the right side of the lower channel (looking up estuary) at times in all estuaries, and was most common in small estuaries closest to the mouth of the primary water source to the estuary. Where Bay influences were strong, estuarine water quality would be expected to be less responsive to nutrient reductions made in the local watershed. Regression analysis was used to evaluate hypothesized relationships between environmental driver variables and average chlorophyll-a (chl-a) concentrations. Chl-a values were calculated from unusually detailed levels of spatial sampling, potentially providing a more comprehensive view of system conditions than that provided by traditional sparse sampling networks. The univariate models with the best data support to explain variability in averaged chl-a concentration were those that reflected water residence time. Of the land cover variables tested, septic density in the riparian zone explained the most variance in chl-a. The multivariate models that most improved upon the residence time effect added TN or TP flows (normalized by volume) and suggested that chl-a will be less responsive to nutrient reductions in estuaries that are poorly flushed.
Barrett, Craig F; Specht, Chelsea D; Leebens-Mack, Jim; Stevenson, Dennis Wm; Zomlefer, Wendy B; Davis, Jerrold I
2014-01-01
Zingiberales comprise a clade of eight tropical monocot families including approx. 2500 species and are hypothesized to have undergone an ancient, rapid radiation during the Cretaceous. Zingiberales display substantial variation in floral morphology, and several members are ecologically and economically important. Deep phylogenetic relationships among primary lineages of Zingiberales have proved difficult to resolve in previous studies, representing a key region of uncertainty in the monocot tree of life. Next-generation sequencing was used to construct complete plastid gene sets for nine taxa of Zingiberales, which were added to five previously sequenced sets in an attempt to resolve deep relationships among families in the order. Variation in taxon sampling, process partition inclusion and partition model parameters were examined to assess their effects on topology and support. Codon-based likelihood analysis identified a strongly supported clade of ((Cannaceae, Marantaceae), (Costaceae, Zingiberaceae)), sister to (Musaceae, (Lowiaceae, Strelitziaceae)), collectively sister to Heliconiaceae. However, the deepest divergences in this phylogenetic analysis comprised short branches with weak support. Additionally, manipulation of matrices resulted in differing deep topologies in an unpredictable fashion. Alternative topology testing allowed statistical rejection of some of the topologies. Saturation fails to explain observed topological uncertainty and low support at the base of Zingiberales. Evidence for conflict among the plastid data was based on a support metric that accounts for conflicting resampled topologies. Many relationships were resolved with robust support, but the paucity of character information supporting the deepest nodes and the existence of conflict suggest that plastid coding regions are insufficient to resolve and support the earliest divergences among families of Zingiberales. Whole plastomes will continue to be highly useful in plant phylogenetics, but the current study adds to a growing body of literature suggesting that they may not provide enough character information for resolving ancient, rapid radiations.
Barrett, Craig F.; Specht, Chelsea D.; Leebens-Mack, Jim; Stevenson, Dennis Wm.; Zomlefer, Wendy B.; Davis, Jerrold I.
2014-01-01
Background and Aims Zingiberales comprise a clade of eight tropical monocot families including approx. 2500 species and are hypothesized to have undergone an ancient, rapid radiation during the Cretaceous. Zingiberales display substantial variation in floral morphology, and several members are ecologically and economically important. Deep phylogenetic relationships among primary lineages of Zingiberales have proved difficult to resolve in previous studies, representing a key region of uncertainty in the monocot tree of life. Methods Next-generation sequencing was used to construct complete plastid gene sets for nine taxa of Zingiberales, which were added to five previously sequenced sets in an attempt to resolve deep relationships among families in the order. Variation in taxon sampling, process partition inclusion and partition model parameters were examined to assess their effects on topology and support. Key Results Codon-based likelihood analysis identified a strongly supported clade of ((Cannaceae, Marantaceae), (Costaceae, Zingiberaceae)), sister to (Musaceae, (Lowiaceae, Strelitziaceae)), collectively sister to Heliconiaceae. However, the deepest divergences in this phylogenetic analysis comprised short branches with weak support. Additionally, manipulation of matrices resulted in differing deep topologies in an unpredictable fashion. Alternative topology testing allowed statistical rejection of some of the topologies. Saturation fails to explain observed topological uncertainty and low support at the base of Zingiberales. Evidence for conflict among the plastid data was based on a support metric that accounts for conflicting resampled topologies. Conclusions Many relationships were resolved with robust support, but the paucity of character information supporting the deepest nodes and the existence of conflict suggest that plastid coding regions are insufficient to resolve and support the earliest divergences among families of Zingiberales. Whole plastomes will continue to be highly useful in plant phylogenetics, but the current study adds to a growing body of literature suggesting that they may not provide enough character information for resolving ancient, rapid radiations. PMID:24280362
Fisher, William A; Rosen, Raymond C; Eardley, Ian; Niederberger, Craig; Nadel, Andrea; Kaufman, Joel; Sand, Michael
2004-09-01
The aim of Phase II of the Men's Attitudes to Life Events and Sexuality (MALES) Study is to explore PDE5 inhibitor treatment seeking among men with erectile dysfunction (ED). Phase II of the MALES study involved 2,912 men, aged 20-75 years, from 8 countries (U.S., U.K., Germany, France, Italy, Spain, Mexico, and Brazil), who reported ED. Participants were recruited from the MALES Phase I sample [1] and via booster methods (e.g., physician referral, street interception), and completed self-report questionnaires concerning the characteristics of their ED, their efforts to seek PDE5 inhibitor treatment for their sexual dysfunction, and attitudinal and referent influences that potentially affect treatment-seeking. Statistical analyses focus on identification of correlates of PDE5 inhibitor treatment seeking. PDE5 inhibitor utilization is strongly associated with ED sufferers' assessment of the severity of their sexual dysfunction, with their belief that medication for ED is dangerous, and with their perceptions of whether physicians, other professionals, and spouses or family members are supportive of their seeking treatment. ED sufferers who evaluate their sexual dysfunction as severe, who believe that medication for ED is not dangerous, and who perceive support for treatment seeking from referent others, are more likely to utilize PDE5 inhibitor treatment. Findings indicate that perceived ED severity, beliefs about ED medication, and referent influences are strongly correlated with utilization of PDE5 inhibitor therapy. These findings aid our understanding of factors that may incline men with ED to seek-or to avoid-PDE5 inhibitor therapy for their sexual dysfunction, and provide a basis for clinical and educational interventions to assist men with ED to seek appropriate treatment.
Molarius, Anu; Granström, Fredrik
2018-04-28
Mental health problems are more frequent in socially disadvantaged groups, but the results vary between different studies, different populations and different measures of mental health. This paper investigated the association between educational level, economic difficulties and psychological distress in men and women in Sweden. The study population included 24 510 respondents aged 25-74 years who responded to a survey questionnaire in Mid-Sweden in 2012 (response rate 53%). Psychological distress was measured with the 12-item version of the General Health Questionnaire, and multivariate logistic regression models were used in statistical analyses, adjusting for age, employment status and social support. The prevalence of psychological distress was higher in women (16.4%) than in men (11.3%; p<0.001). Persons with low and medium educational level had a lower risk of psychological distress than persons with high educational level after adjustment for confounders. Economic difficulties had a strong association with psychological distress (OR 2.80 (95% CI 2.39 to 3.27) and OR 2.40 (95% CI 2.12 to 3.71) in men and women, respectively) after adjustment for confounders. We found a strong association between economic difficulties and psychological distress in this study, but no inverse association between educational level and psychological distress. On the contrary, persons with high education had more psychological distress than persons with low and medium education when age, employment status and social support were taken into account. The findings were similar in men and women. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Conflict between the work and family domains and exhaustion among vocationally active men and women.
Canivet, Catarina; Ostergren, Per-Olof; Lindeberg, Sara I; Choi, BongKyoo; Karasek, Robert; Moghaddassi, Mahnaz; Isacsson, Sven-Olof
2010-04-01
Exhaustion is consistently found to be more prevalent in women than in men. Women suffer from job strain more often, which may constitute a partial explanation for this phenomenon, but experienced shortcomings in combining work and family demands may also contribute to ill health. The aim of this study was to investigate, and analyse by gender, how work-related and family-related factors, as well as the interface between them, i.e. work-to-family conflict (WFC) and family-to-work conflict (FWC), are related to exhaustion. The study was cross-sectional with self-administered questionnaires assessing exposures and outcome with previously well-validated instruments. The participants were 2726 men and 2735 women, aged 45-64, vocationally active, and residing in Malmö, Sweden. Sixteen percent of the women and 8% of the men considered themselves exhausted. WFC, FWC, job strain, and low job support were all strongly correlated to exhaustion in both genders. In the multivariate analyses, adjusting for other work and family risk factors, WFC and FWC remained statistically significant risk factors for exhaustion in both men and women. Job strain, low job support, and having a somatic disorder were also independently associated with exhaustion. While WFC was more prevalent among men, it was more strongly associated with exhaustion in women than in men. In women, WFC and FWC contributed to a larger part of the explanatory power of the model, which amounted to 22% of the variance in women and 14% in men. The results imply that the concept of 'work stress' should be regarded in a wider context in order to understand gender related issues of exhaustion among vocationally active individuals. Copyright 2010 Elsevier Ltd. All rights reserved.
Are algal genes in nonphotosynthetic protists evidence of historical plastid endosymbioses?
Stiller, John W; Huang, Jinling; Ding, Qin; Tian, Jing; Goodwillie, Carol
2009-10-20
How photosynthetic organelles, or plastids, were acquired by diverse eukaryotes is among the most hotly debated topics in broad scale eukaryotic evolution. The history of plastid endosymbioses commonly is interpreted under the "chromalveolate" hypothesis, which requires numerous plastid losses from certain heterotrophic groups that now are entirely aplastidic. In this context, discoveries of putatively algal genes in plastid-lacking protists have been cited as evidence of gene transfer from a photosynthetic endosymbiont that subsequently was lost completely. Here we examine this evidence, as it pertains to the chromalveolate hypothesis, through genome-level statistical analyses of similarity scores from queries with two diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana, and two aplastidic sister taxa, Phytophthora ramorum and P. sojae. Contingency tests of specific predictions of the chromalveolate model find no evidence for an unusual red algal contribution to Phytophthora genomes, nor that putative cyanobacterial sequences that are present entered these genomes through a red algal endosymbiosis. Examination of genes unrelated to plastid function provide extraordinarily significant support for both of these predictions in diatoms, the control group where a red endosymbiosis is known to have occurred, but none of that support is present in genes specifically conserved between diatoms and oomycetes. In addition, we uncovered a strong association between overall sequence similarities among taxa and relative sizes of genomic data sets in numbers of genes. Signal from "algal" genes in oomycete genomes is inconsistent with the chromalveolate hypothesis, and better explained by alternative models of sequence and genome evolution. Combined with the numerous sources of intragenomic phylogenetic conflict characterized previously, our results underscore the potential to be mislead by a posteriori interpretations of variable phylogenetic signals contained in complex genome-level data. They argue strongly for explicit testing of the different a priori assumptions inherent in competing evolutionary hypotheses.
Rudasingwa, Martin; Soeters, Robert; Bossuyt, Michel
2015-01-01
To strengthen the health care delivery, the Burundian Government in collaboration with international NGOs piloted performance-based financing (PBF) in 2006. The health facilities were assigned - by using a simple matching method - to begin PBF scheme or to continue with the traditional input-based funding. Our objective was to analyse the effect of that PBF scheme on the quality of health services between 2006 and 2008. We conducted the analysis in 16 health facilities with PBF scheme and 13 health facilities without PBF scheme. We analysed the PBF effect by using 58 composite quality indicators of eight health services: Care management, outpatient care, maternity care, prenatal care, family planning, laboratory services, medicines management and materials management. The differences in quality improvement in the two groups of health facilities were performed applying descriptive statistics, a paired non-parametric Wilcoxon Signed Ranks test and a simple difference-in-difference approach at a significance level of 5%. We found an improvement of the quality of care in the PBF group and a significant deterioration in the non-PBF group in the same four health services: care management, outpatient care, maternity care, and prenatal care. The findings suggest a PBF effect of between 38 and 66 percentage points (p<0.001) in the quality scores of care management, outpatient care, prenatal care, and maternal care. We found no PBF effect on clinical support services: laboratory services, medicines management, and material management. The PBF scheme in Burundi contributed to the improvement of the health services that were strongly under the control of medical personnel (physicians and nurses) in a short time of two years. The clinical support services that did not significantly improved were strongly under the control of laboratory technicians, pharmacists and non-medical personnel. PMID:25948432
Three in One—Multiple Faunal Elements within an Endangered European Butterfly Species
Junker, Marius; Zimmermann, Marie; Ramos, Ana A.; Gros, Patrick; Konvička, Martin; Nève, Gabriel; Rákosy, László; Tammaru, Toomas
2015-01-01
Ice ages within Europe forced many species to retreat to refugia, of which three major biogeographic basic types can be distinguished: "Mediterranean", "Continental" and "Alpine / Arctic" species. However, this classification often fails to explain the complex phylogeography of European species with a wide range of latitudinal and altitudinal distribution. Hence, we tested for the possibility that all three mentioned faunal elements are represented within one species. Our data was obtained by scoring 1,307 Euphydryas aurinia individuals (46 European locations) for 17 allozyme loci, and sequencing a subset of 492 individuals (21 sites) for a 626 base pairs COI fragment. Genetic diversity indices, F statistics, hierarchical analyses of molecular variance, individual-based clustering, and networks were used to explore the phylogeographic patterns. The COI fragment represented 18 haplotypes showing a strong geographic structure. All but one allozyme loci analysed were polymorphic with a mean F ST of 0.20, supporting a pronounced among population structure. Interpretation of both genetic marker systems, using several analytical tools, calls for the recognition of twelve genetic groups. These analyses consistently distinguished different groups in Iberia (2), Italy, Provence, Alps (3), Slovenia, Carpathian Basin, the lowlands of West and Central Europe as well as Estonia, often with considerable additional substructures. The genetic data strongly support the hypothesis that E. aurinia survived the last glaciation in Mediterranean, extra-Mediterranean and perialpine refugia. It is thus a rare example of a model organism that combines attributes of faunal elements from all three of these sources. The observed differences between allozymes and mtDNA most likely result from recent introgression of mtDNA into nuclear allozyme groups. Our results indicate discrepancies with the morphologically-based subspecies models, underlining the need to revise the current taxonomy. PMID:26566029
Does climate directly influence NPP globally?
Chu, Chengjin; Bartlett, Megan; Wang, Youshi; He, Fangliang; Weiner, Jacob; Chave, Jérôme; Sack, Lawren
2016-01-01
The need for rigorous analyses of climate impacts has never been more crucial. Current textbooks state that climate directly influences ecosystem annual net primary productivity (NPP), emphasizing the urgent need to monitor the impacts of climate change. A recent paper challenged this consensus, arguing, based on an analysis of NPP for 1247 woody plant communities across global climate gradients, that temperature and precipitation have negligible direct effects on NPP and only perhaps have indirect effects by constraining total stand biomass (Mtot ) and stand age (a). The authors of that study concluded that the length of the growing season (lgs ) might have a minor influence on NPP, an effect they considered not to be directly related to climate. In this article, we describe flaws that affected that study's conclusions and present novel analyses to disentangle the effects of stand variables and climate in determining NPP. We re-analyzed the same database to partition the direct and indirect effects of climate on NPP, using three approaches: maximum-likelihood model selection, independent-effects analysis, and structural equation modeling. These new analyses showed that about half of the global variation in NPP could be explained by Mtot combined with climate variables and supported strong and direct influences of climate independently of Mtot , both for NPP and for net biomass change averaged across the known lifetime of the stands (ABC = average biomass change). We show that lgs is an important climate variable, intrinsically correlated with, and contributing to mean annual temperature and precipitation (Tann and Pann ), all important climatic drivers of NPP. Our analyses provide guidance for statistical and mechanistic analyses of climate drivers of ecosystem processes for predictive modeling and provide novel evidence supporting the strong, direct role of climate in determining vegetation productivity at the global scale. © 2015 John Wiley & Sons Ltd.
A Novel Technique to Measure In Vivo Uterine Suspensory Ligament Stiffness
Smith, Tovia M.; Luo, Jiajia; Hsu, Yvonne; Ashton-Miller, James A.; Delancey, John O.L.
2013-01-01
Objective To describe a new computer-controlled research apparatus for measuring in vivo uterine ligament force-displacement behavior and stiffness and to present pilot data in women with and without prolapse. Study Design Seventeen women with varying uterine support underwent testing in the operating room (OR) after anesthetic induction. A tripod-mounted computer-controlled linear servoactuator was used to quantify force-displacement behavior of the cervix and supporting ligaments. The servoactuator applied a caudally-directed force to a tenaculum at 4 mm/s velocity until the traction force reached 17.8N (4 lbs.). Cervix location on POP-Q in clinic, in the OR at rest, and with minimal force (<1.1N), and maximum force (17.8N) was recorded. Ligament “stiffness” between minimum and maximum force was calculated. Results The mean (SD) subject age was 54.5 (12.7) years, parity 2.9 (1.1), BMI 29.0 (4.3) kg/m2, and POP-Q point C −3.1 (3.9) cm. POP-Q point C was most strongly correlated with cervix location at maximum force (r=+0.68, p=.003) and at rest (r=+0.62, p=.009). Associations between cervix location at minimum force (r=+0.46, p=.059) and ligament stiffness (r= −0.44,p=.079) were not statistically significant. Cervix location in the OR with minimal traction lay below the lowest point found on POP-Q for 13 women. Conclusions POP-Q point C was strongly correlated with cervix location at rest and at maximum traction force; however only 19% of the variation in POP-Q point C location was explained by ligament stiffness. The cervix location in the OR at minimal traction lay below POP-Q point C value in ¾ of women. PMID:23747493
Beeman, John; Hansel, Hal; Perry, Russell; Hockersmith, Eric; Sandford, Ben
2011-01-01
This report describes analyses of data from radio- or acoustic-tagged juvenile salmonids passing through hydro-dam turbines to determine factors affecting fish survival. The data were collected during a series of studies designed to estimate passage and survival probabilities at McNary (2002-09) and John Day (2002-03) Dams on the Columbia River during controlled experiments of structures or operations at spillways. Relatively few tagged fish passed turbines in any single study, but sample sizes generally were adequate for our analyses when data were combined from studies using common methods over a series of years. We used information-theoretic methods to evaluate biological, operational, and group covariates by creating models fitting linear (all covariates) or curvilinear (operational covariates only) functions to the data. Biological covariates included tag burden, weight, and water temperature; operational covariates included spill percentage, total discharge, hydraulic head, and turbine unit discharge; and group covariates included year, treatment, and photoperiod. Several interactions between the variables also were considered. Support of covariates by the data was assessed by comparing the Akaike Information Criterion of competing models. The analyses were conducted because there was a lack of information about factors affecting survival of fish passing turbines volitionally and the data were available from past studies. The depth of acclimation, tag size relative to fish size (tag burden), turbine unit discharge, and area of entry into the turbine intake have been shown to affect turbine passage survival of juvenile salmonids in other studies. This study indicates that turbine passage survival of the study fish was primarily affected by biological covariates rather than operational covariates. A negative effect of tag burden was strongly supported in data from yearling Chinook salmon at John Day and McNary dams, but not for subyearling Chinook salmon or juvenile steelhead. The negative effect of tag burden in data we examined from yearling Chinook salmon supports the recent findings from laboratory studies of barotrauma effects. A curvilinear (quadratic) effect of turbine unit discharge was weakly supported in data from subyearling Chinook salmon at John Day Dam. The maximum survival from those data was estimated to occur at a discharge of 15.9 thousand cubic feet per second, but the estimate was imprecise (95 percent confidence interval of -1.7-33.7 thousand cubic feet per second). This estimate is within the range of 1 percent of peak turbine operating efficiency (12.0-21.6 thousand cubic feet per second), but is lower than the 17.2 thousand cubic feet per second discharge at peak operating efficiency (at a head of 102 feet near the median in the data we examined). Effects of water temperature were supported in four of the five examined data sets and were strongly supported in all but one. Spill percentage, head, and total discharge received weak or moderate support in some cases. The results are consistent with those of several controlled field experiments of turbine discharge. Studies based on the Hi-Z Turb'N tag (balloon tag) often show small, generally statistically insignificant, differences in survival at different turbine discharge levels. Some studies also show that a quadratic equation can be well fit to the relation of survival and turbine unit discharge. The lack of support for the operational covariates in most of the data sets we examined may be due to the small effect turbine discharge has even in controlled studies, the observational nature of the data we used, and the evaluation method. We assessed support of the data for models of linear and quadratic effects, whereas controlled experiments often statistically compare the point estimates of survival from each operational treatment studied. The results of our analyses suggest tag burden should be minimized or controlled for in analyses of future stu
Martinez-Murcia, Francisco Jesús; Lai, Meng-Chuan; Górriz, Juan Manuel; Ramírez, Javier; Young, Adam M H; Deoni, Sean C L; Ecker, Christine; Lombardo, Michael V; Baron-Cohen, Simon; Murphy, Declan G M; Bullmore, Edward T; Suckling, John
2017-03-01
Neuroimaging studies have reported structural and physiological differences that could help understand the causes and development of Autism Spectrum Disorder (ASD). Many of them rely on multisite designs, with the recruitment of larger samples increasing statistical power. However, recent large-scale studies have put some findings into question, considering the results to be strongly dependent on the database used, and demonstrating the substantial heterogeneity within this clinically defined category. One major source of variance may be the acquisition of the data in multiple centres. In this work we analysed the differences found in the multisite, multi-modal neuroimaging database from the UK Medical Research Council Autism Imaging Multicentre Study (MRC AIMS) in terms of both diagnosis and acquisition sites. Since the dissimilarities between sites were higher than between diagnostic groups, we developed a technique called Significance Weighted Principal Component Analysis (SWPCA) to reduce the undesired intensity variance due to acquisition site and to increase the statistical power in detecting group differences. After eliminating site-related variance, statistically significant group differences were found, including Broca's area and the temporo-parietal junction. However, discriminative power was not sufficient to classify diagnostic groups, yielding accuracies results close to random. Our work supports recent claims that ASD is a highly heterogeneous condition that is difficult to globally characterize by neuroimaging, and therefore different (and more homogenous) subgroups should be defined to obtain a deeper understanding of ASD. Hum Brain Mapp 38:1208-1223, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Attitudes toward Abortion among Providers of Reproductive Health Care.
Dodge, Laura E; Haider, Sadia; Hacker, Michele R
2016-01-01
Access to abortion continues to decrease in the United States. The aim of this study was to explore attitudes toward abortion among clinicians who provide reproductive health care. Clinician members of several reproductive health professional organizations completed a self-administered survey that assessed their attitudes toward abortion. A total of 278 clinicians who provided clinical reproductive health services within the United States were included. Nearly all strongly agreed that abortion should be available in cases of rape (89.6%), incest (89.2%), life endangerment (93.2%), health endangerment (91.0%), and fetal anomaly (85.9%). Although most strongly disagreed that spousal notification (81.3%) and spousal consent (86.6%) should be required for married women, fewer strongly disagreed that parental notification (57.6%) and parental consent (66.9%) should be required for minors. Respondents were generally supportive of private insurance coverage (70.1% strongly agreed) and Medicaid coverage (65.0% strongly agreed) for abortion services. Support for legal abortion and public funding of abortion were significantly associated with being female (both p ≤ .03) and having no personal religious affiliation (both p ≤ .04). Younger respondents and men were more supportive of third-party involvement and mandatory counseling (all p ≤ .02). Abortion providers were significantly more supportive of abortion access (legality of abortion, public and private funding, no third-party involvement, and no mandated counseling) than nonproviders (all p < .001). Although reproductive health care providers were generally supportive of legal abortion and funding for abortion, lower support among younger respondents may indicate future difficulties in maintaining a clinical workforce that is willing to provide abortion care. Copyright © 2016 Jacobs Institute of Women's Health. Published by Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Dondeynaz, C.; López Puga, J.; Carmona Moreno, C.
2013-09-01
Despite the efforts made towards the Millennium Development Goals targets during the last decade, improved access to water supply or basic sanitation still remains unavailable for millions of people across the world. This paper proposes a set of models that use 25 key variables and country profiles from the WatSan4Dev data set involving water supply and sanitation (Dondeynaz et al., 2012). This paper suggests the use of Bayesian network modelling methods because they are more easily adapted to deal with non-normal distributions, and integrate a qualitative approach for data analysis. They also offer the advantage of integrating preliminary knowledge into the probabilistic models. The statistical performance of the proposed models ranges between 20 and 5% error rates, which are very satisfactory taking into account the strong heterogeneity of variables. Probabilistic scenarios run from the models allow an assessment of the relationships between human development, external support, governance aspects, economic activities and water supply and sanitation (WSS) access. According to models proposed in this paper, gaining a strong poverty reduction will require the WSS access to reach 75-76% through: (1) the management of ongoing urbanisation processes to avoid slums development; and (2) the improvement of health care, for instance for children. Improving governance, such as institutional efficiency, capacities to make and apply rules, or control of corruption is positively associated with WSS sustainable development. The first condition for an increment of the HDP (human development and poverty) remains of course an improvement of the economic conditions with higher household incomes. Moreover, a significant country commitment to the environment, associated with civil society freedom of expression constitutes a favourable setting for sustainable WSS services delivery. Intensive agriculture using irrigation practises also appears as a mean for sustainable WSS thanks to multi-uses and complementarities. With a WSS sector organised at national level, irrigation practices can support the structuring and efficiency of the agriculture sector. It may then induce rural development in areas where WSS access often is set back compared to urban areas1. External financial support, called Official Development Assistance (ODA CI), plays a role in WSS improvement but comes last in the sensitivity analyses of models. An overall 47% of the Official Development Assistance goes first to poor countries, and is associated to governance aspects: (1) political stability and (2) country commitment to the environment and civil society degree of freedom. These governance aspects constitute a good framework for aid implementation in recipient countries. Modelling is run with the five groups of countries as defined in Dondeynaz et al. (2012). Models for profile 4 (essential external support) and profile 5 (primary material consumption) are specifically detailed and analysed in this paper. For countries in profile 4, fighting against water scarcity and progressing desertification should be the priority. However, for countries in profile 5, efforts should first concentrate on consolidation of political stability while supporting diversification of the economic activities. Nevertheless, for both profiles, reduction of poverty should remain the first priority as previously indicated. 1 JMP statistics, 2004 http://www.wssinfo.org/data-estimates/table/, last access: 22 July 2013.
Turnover Among Air Force Nurses.
1987-03-01
Statistics. - The U. S. Air Force Institute of Technology, Civilian Institutions , Allied Health Branch, for their assistance and partial financial support...The University of Utah, Computer Center, for their financial support and use of computer equipment used in the statistical analysis. xiv The following...retain the nurses currently employed (Decker, et al., 19S2; Weisman, 1982). White (1980) concludes that nursina staff is a considerable [ financial
NASA Technical Reports Server (NTRS)
Gardner, Adrian
2010-01-01
National Aeronautical and Space Administration (NASA) weather and atmospheric environmental organizations are insatiable consumers of geophysical, hydrometeorological and solar weather statistics. The expanding array of internet-worked sensors producing targeted physical measurements has generated an almost factorial explosion of near real-time inputs to topical statistical datasets. Normalizing and value-based parsing of such statistical datasets in support of time-constrained weather and environmental alerts and warnings is essential, even with dedicated high-performance computational capabilities. What are the optimal indicators for advanced decision making? How do we recognize the line between sufficient statistical sampling and excessive, mission destructive sampling ? How do we assure that the normalization and parsing process, when interpolated through numerical models, yields accurate and actionable alerts and warnings? This presentation will address the integrated means and methods to achieve desired outputs for NASA and consumers of its data.
Response to comments on "Productivity is a poor predictor of plant species richness"
Grace, James B.; Adler, Peter B.; Seabloom, Eric W.; Borer, Elizabeth T.; Hillebrand, Helmut; Hautier, Yann; Hector, Andy; Harpole, W. Stanley; O'Halloran, Lydia R.; Anderson, T. Michael; Bakker, Jonathan D.; Brown, Cynthia S.; Buckley, Yvonne M.; Collins, Scott L.; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen Ingman; Davies, Kendi F.; DeCrappeo, Nicole M.; Fay, Philip A.; Firn, Jennifer; Gruner, Daniel S.; Hagenah, Nicole; Jin, Virginia L.; Kirkman, Kevin P.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Lambrinos, John G.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Orrock, John L.; Prover, Suzanne M.; Stevens, Carly J.; Wragg, Peter D.; Yang, Louie H.
2012-01-01
Pan et al. claim that our results actually support a strong linear positive relationship between productivity and richness, whereas Fridley et al. contend that the data support a strong humped relationship. These responses illustrate how preoccupation with bivariate patterns distracts from a deeper understanding of the multivariate mechanisms that control these important ecosystem properties.
Recent statistical methods for orientation data
NASA Technical Reports Server (NTRS)
Batschelet, E.
1972-01-01
The application of statistical methods for determining the areas of animal orientation and navigation are discussed. The method employed is limited to the two-dimensional case. Various tests for determining the validity of the statistical analysis are presented. Mathematical models are included to support the theoretical considerations and tables of data are developed to show the value of information obtained by statistical analysis.
Young, Katelyn A; Lane, Samantha M; Widger, John E; Neuhaus, Nina M; Dove, James T; Fluck, Marcus; Hunsinger, Marie A; Blansfield, Joseph A; Shabahang, Mohsen M
Characterize the concordance among faculty and resident perceptions of surgical case complexity, resident technical performance, and autonomy in a diverse sample of general surgery procedures using case-specific evaluations. A prospective study was conducted in which a faculty surgeon and surgical resident independently completed a postoperative assessment examining case complexity, resident operative performance (Milestone assessment) and autonomy (Zwisch model). Pearson correlation coefficients (r) reaching statistical significance (p < 0.05) were further classified as moderate (r ≥ 0.40), strong (r ≥ 0.60), or very strong (r ≥ 0.80). This study was conducted in the General Surgery Residency Program at an academic tertiary care facility (Geisinger Medical Center, Danville, PA). Participants included 6 faculty surgeons, in addition to 5 postgraduate year (PGY) 1, 6 midlevel (PGY 2-3), and 4 chief (PGY 4-5) residents. In total, 75 surgical cases were analyzed. Midlevel residents accounted for the highest number of cases (35, 46.6%). Overall, faculty and resident perceptions of case complexity demonstrated a strong correlation (r = 0.76, p < 0.0001). Technical performance scores were also strongly correlated (r = 0.66, p < 0.0001), whereas perceptions of autonomy demonstrated a moderate correlation (r = 0.56, p < 0.0001). Subgroup analysis revealed very strong correlations among faculty perceptions of case complexity and the perceptions of PGY 1 (r = 0.80, p < 0.0001) and chief residents (r = 0.82, p < 0.0001). All other intergroup correlations were strong with 2 notable exceptions as follows: midlevel and chief residents failed to correlate with faculty perceptions of autonomy and operative performance, respectively. General surgery residents generally demonstrated high correlations with faculty perceptions of case complexity, technical performance, and operative autonomy. This generalized accord supports the use of the Milestone and Zwisch assessments in residency programs. However, discordance among perceptions of midlevel resident autonomy and chief resident operative performance suggests that these trainees may need more direct communication from the faculty. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
From motivation to acceptability: a survey of public attitudes towards organ donation in Denmark.
Nordfalk, Francisca; Olejaz, Maria; Jensen, Anja M B; Skovgaard, Lea Larsen; Hoeyer, Klaus
2016-01-01
Over the past three decades, public attitudes to organ donation have been a subject of numerous studies focusing on donor motivation. Here, we present a fresh approach. We suggest focusing on public acceptability instead of motivation. The point is to understand public attitudes well enough to avoid risking public support for organ transplantation. We conducted the study in Denmark because there have been significant developments in public attitudes to organ donation in this country. In the 1990s, Denmark was a country with very low public support for organ donation and Denmark was the last country in Europe to introduce brain death as a legal criterion of death, whereas today Eurobarometer surveys rate Denmark as one of the European countries with the highest support for deceased organ donation from brain dead donors. We conducted a telephone survey in Denmark (N = 1195). A questionnaire was developed on the basis of preceding qualitative studies and pilot testing and included reuse of one item from earlier surveys to facilitate historical comparison. The analysis of the data was carried out using IBM SPSS Statistics 22 and focused on descriptive statistics. A clear majority of 91.9 % are positive or very positive towards organ donation; 85.8 % like the idea of their body being used after their death, 85.0 % is willing to donate their own organs, 82.1 % to donate their tissue and only 2.3 % find that too much has been done to promote organ donation. There is limited support for monetary incentives for organ donation (5.8 %) and presumed consent (30.4 %), while a majority (63.9 %) supports making it mandatory to register a personal decision. Religious self-identification has limited impact on attitudes. We can identify a shift over the past three decades from marked opposition to organ transplantation to strong support as well as a pattern in the contemporary public attitudes, which can help explain what is central to public acceptability: self-determination. Policies fostering choice are met with a majority of positive attitudes, while presumed consent and monetary incentives are met with more negative attitudes. Our approach calls for comparative studies in other countries to generate a better overall understanding of the conditions of acceptability, which need to be in place to ensure the long-term social robustness of organ donation and thereby safeguard this important medical technology.
Topics in strong Langmuir turbulence
NASA Technical Reports Server (NTRS)
Nicholson, D. R.
1983-01-01
Progress in two approaches to the study of strong Langmuir turbulence is reported. In two spatial dimensions, numerical solution of the Zakharov equations yields a steady state involving linear growth, linear damping, and a collection of coherent, long-lived entities which might loosely be called solitons. In one spatial dimension, a statistical theory is applied to the cubically nonlinear Schroedinger equation and is solved analytically in a special case.
Topics in strong Langmuir turbulence
NASA Technical Reports Server (NTRS)
Nicholson, D. R.
1982-01-01
Progress in two approaches to the study of strong Langmuir turbulence is reported. In two spatial dimensions, numerical solution of the Zakharov equations yields a steady state involving linear growth, linear damping, and a collection of coherent, long-lived entities which might loosely be called solitons. In one spatial dimension, a statistical theory is applied to the cubically nonlinear Schroedinger equation and is solved analytically in a special case.
Voluntary Support of Education 1987-1988.
ERIC Educational Resources Information Center
Council for Aid to Education, New York, NY.
The 29th edition of a publication featuring statistics on voluntary support of education is presented. Three sections have the following titles: (1) "Colleges and Universities" (including national estimates of expenditures and voluntary support, and survey results noting voluntary support by type of institution, voluntary support by source,…
Applying Sociocultural Theory to Teaching Statistics for Doctoral Social Work Students
ERIC Educational Resources Information Center
Mogro-Wilson, Cristina; Reeves, Michael G.; Charter, Mollie Lazar
2015-01-01
This article describes the development of two doctoral-level multivariate statistics courses utilizing sociocultural theory, an integrative pedagogical framework. In the first course, the implementation of sociocultural theory helps to support the students through a rigorous introduction to statistics. The second course involves students…
Undergraduate Statistics Education and the National Science Foundation
ERIC Educational Resources Information Center
Hall, Megan R.; Rowell, Ginger Holmes
2008-01-01
This paper describes 25 National Science Foundation supported projects that have innovations designed to improve education for students majoring or minoring in statistics. The characteristics of these projects and the common themes which emerge are compared with the American Statistical Association's (ASA) guidelines for developing statistics…
Descriptive Statistical Techniques for Librarians. 2nd Edition.
ERIC Educational Resources Information Center
Hafner, Arthur W.
A thorough understanding of the uses and applications of statistical techniques is integral in gaining support for library funding or new initiatives. This resource is designed to help practitioners develop and manipulate descriptive statistical information in evaluating library services, tracking and controlling limited resources, and analyzing…
Introductory Statistics Education and the National Science Foundation
ERIC Educational Resources Information Center
Hall, Megan R.; Rowell, Ginger Holmes
2008-01-01
This paper describes 27 National Science Foundation supported grant projects that have innovations designed to improve teaching and learning in introductory statistics courses. The characteristics of these projects are compared with the six recommendations given in the "Guidelines for Assessment and Instruction in Statistics Education (GAISE)…
The Role of Emotion in Global Warming Policy Support and Opposition
Smith, Nicholas; Leiserowitz, Anthony
2014-01-01
Prior research has found that affect and affective imagery strongly influence public support for global warming. This article extends this literature by exploring the separate influence of discrete emotions. Utilizing a nationally representative survey in the United States, this study found that discrete emotions were stronger predictors of global warming policy support than cultural worldviews, negative affect, image associations, or sociodemographic variables. In particular, worry, interest, and hope were strongly associated with increased policy support. The results contribute to experiential theories of risk information processing and suggest that discrete emotions play a significant role in public support for climate change policy. Implications for climate change communication are also discussed. PMID:24219420
The role of emotion in global warming policy support and opposition.
Smith, Nicholas; Leiserowitz, Anthony
2014-05-01
Prior research has found that affect and affective imagery strongly influence public support for global warming. This article extends this literature by exploring the separate influence of discrete emotions. Utilizing a nationally representative survey in the United States, this study found that discrete emotions were stronger predictors of global warming policy support than cultural worldviews, negative affect, image associations, or sociodemographic variables. In particular, worry, interest, and hope were strongly associated with increased policy support. The results contribute to experiential theories of risk information processing and suggest that discrete emotions play a significant role in public support for climate change policy. Implications for climate change communication are also discussed. © 2013 Society for Risk Analysis.
The Vagaries Of Public Support For Government Actions In Case Of A Pandemic
Hilyard, Karen M.; Freimuth, Vicki S.; Musa, Donald; Kumar, Supriya; Quinn, Sandra Crouse
2011-01-01
Government health measures in a pandemic are effective only with strong support and compliance from the public. A survey of 1,583 US adults early in the 2009 H1N1 (swine influenza) pandemic shows surprisingly mixed support for possible government efforts to control the spread of the disease, with strong support for more extreme measures such as closing borders and weak support for more basic, and potentially more effective, policies such as encouraging sick people to stay home from work. The results highlight challenges that public health officials and policy makers must address in formulating strategies to respond to a pandemic before a more severe outbreak occurs. PMID:21134932
Agner, Shannon C; Xu, Jun; Madabhushi, Anant
2013-03-01
Segmentation of breast lesions on dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) is the first step in lesion diagnosis in a computer-aided diagnosis framework. Because manual segmentation of such lesions is both time consuming and highly susceptible to human error and issues of reproducibility, an automated lesion segmentation method is highly desirable. Traditional automated image segmentation methods such as boundary-based active contour (AC) models require a strong gradient at the lesion boundary. Even when region-based terms are introduced to an AC model, grayscale image intensities often do not allow for clear definition of foreground and background region statistics. Thus, there is a need to find alternative image representations that might provide (1) strong gradients at the margin of the object of interest (OOI); and (2) larger separation between intensity distributions and region statistics for the foreground and background, which are necessary to halt evolution of the AC model upon reaching the border of the OOI. In this paper, the authors introduce a spectral embedding (SE) based AC (SEAC) for lesion segmentation on breast DCE-MRI. SE, a nonlinear dimensionality reduction scheme, is applied to the DCE time series in a voxelwise fashion to reduce several time point images to a single parametric image where every voxel is characterized by the three dominant eigenvectors. This parametric eigenvector image (PrEIm) representation allows for better capture of image region statistics and stronger gradients for use with a hybrid AC model, which is driven by both boundary and region information. They compare SEAC to ACs that employ fuzzy c-means (FCM) and principal component analysis (PCA) as alternative image representations. Segmentation performance was evaluated by boundary and region metrics as well as comparing lesion classification using morphological features from SEAC, PCA+AC, and FCM+AC. On a cohort of 50 breast DCE-MRI studies, PrEIm yielded overall better region and boundary-based statistics compared to the original DCE-MR image, FCM, and PCA based image representations. Additionally, SEAC outperformed a hybrid AC applied to both PCA and FCM image representations. Mean dice similarity coefficient (DSC) for SEAC was significantly better (DSC = 0.74 ± 0.21) than FCM+AC (DSC = 0.50 ± 0.32) and similar to PCA+AC (DSC = 0.73 ± 0.22). Boundary-based metrics of mean absolute difference and Hausdorff distance followed the same trends. Of the automated segmentation methods, breast lesion classification based on morphologic features derived from SEAC segmentation using a support vector machine classifier also performed better (AUC = 0.67 ± 0.05; p < 0.05) than FCM+AC (AUC = 0.50 ± 0.07), and PCA+AC (AUC = 0.49 ± 0.07). In this work, we presented SEAC, an accurate, general purpose AC segmentation tool that could be applied to any imaging domain that employs time series data. SE allows for projection of time series data into a PrEIm representation so that every voxel is characterized by the dominant eigenvectors, capturing the global and local time-intensity curve similarities in the data. This PrEIm allows for the calculation of strong tensor gradients and better region statistics than the original image intensities or alternative image representations such as PCA and FCM. The PrEIm also allows for building a more accurate hybrid AC scheme.
Tuckerman, Jane; Thomas, Natalie; Marshall, Helen S
2016-03-29
Several immunisations including influenza and pertussis are specifically recommended for healthcare workers (HCW) and childcare workers (CCW). This study aimed to assess community attitudes to HCW and CCW immunisation recommendations for pertussis and seasonal influenza. A cross-sectional study was conducted by Computer Assisted Telephone Interviewing (CATI) from April to May 2011. Statistical analyses used data weighted to the South Australian population by probability of selection, age, gender and geographical location using benchmarks derived from the 2009 Census population figures. Almost all respondents supported vaccination of HCWs and CCWs against pertussis and influenza. For pertussis, 95.3% agreed nurses, 94.9% agreed doctors and 94.7% agreed CCWs have an obligation to be vaccinated. For influenza, 91.4% agreed nurses, 90.7% agreed doctors and 89.9% agreed CCWs have an obligation to be vaccinated. We identified higher support for protection against pertussis compared to influenza for all three groups of workers (p<0.001). There were higher concerns if CCWs compared to HCWs were not vaccinated against pertussis (OR=2.78) and influenza (OR=1.99). Young (18-30 years) and older age (60+ years) and lower educational attainment were predictors of support for HCWs and CCWs to be vaccinated against influenza. For pertussis, lower educational attainment was a predictor of support for HCWs immunisation. Community support for CCW and HCW immunisation is strong with CCW immunisation was considered a priority. Pertussis immunisation was considered a higher priority than influenza immunisation for HCWs and CCWs. CCW immunisation should be considered for inclusion in public health immunisation programmes. Copyright © 2016 Elsevier Ltd. All rights reserved.
Seven new dolphin mitochondrial genomes and a time-calibrated phylogeny of whales
Xiong, Ye; Brandley, Matthew C; Xu, Shixia; Zhou, Kaiya; Yang, Guang
2009-01-01
Background The phylogeny of Cetacea (whales) is not fully resolved with substantial support. The ambiguous and conflicting results of multiple phylogenetic studies may be the result of the use of too little data, phylogenetic methods that do not adequately capture the complex nature of DNA evolution, or both. In addition, there is also evidence that the generic taxonomy of Delphinidae (dolphins) underestimates its diversity. To remedy these problems, we sequenced the complete mitochondrial genomes of seven dolphins and analyzed these data with partitioned Bayesian analyses. Moreover, we incorporate a newly-developed "relaxed" molecular clock to model heterogenous rates of evolution among cetacean lineages. Results The "deep" phylogenetic relationships are well supported including the monophyly of Cetacea and Odontoceti. However, there is ambiguity in the phylogenetic affinities of two of the river dolphin clades Platanistidae (Indian River dolphins) and Lipotidae (Yangtze River dolphins). The phylogenetic analyses support a sister relationship between Delphinidae and Monodontidae + Phocoenidae. Additionally, there is statistically significant support for the paraphyly of Tursiops (bottlenose dolphins) and Stenella (spotted dolphins). Conclusion Our phylogenetic analysis of complete mitochondrial genomes using recently developed models of rate autocorrelation resolved the phylogenetic relationships of the major Cetacean lineages with a high degree of confidence. Our results indicate that a rapid radiation of lineages explains the lack of support the placement of Platanistidae and Lipotidae. Moreover, our estimation of molecular divergence dates indicates that these radiations occurred in the Middle to Late Oligocene and Middle Miocene, respectively. Furthermore, by collecting and analyzing seven new mitochondrial genomes, we provide strong evidence that the delphinid genera Tursiops and Stenella are not monophyletic, and the current taxonomy masks potentially interesting patterns of morphological, physiological, behavioral, and ecological evolution. PMID:19166626
A stochastic fractional dynamics model of space-time variability of rain
NASA Astrophysics Data System (ADS)
Kundu, Prasun K.; Travis, James E.
2013-09-01
varies in space and time in a highly irregular manner and is described naturally in terms of a stochastic process. A characteristic feature of rainfall statistics is that they depend strongly on the space-time scales over which rain data are averaged. A spectral model of precipitation has been developed based on a stochastic differential equation of fractional order for the point rain rate, which allows a concise description of the second moment statistics of rain at any prescribed space-time averaging scale. The model is thus capable of providing a unified description of the statistics of both radar and rain gauge data. The underlying dynamical equation can be expressed in terms of space-time derivatives of fractional orders that are adjusted together with other model parameters to fit the data. The form of the resulting spectrum gives the model adequate flexibility to capture the subtle interplay between the spatial and temporal scales of variability of rain but strongly constrains the predicted statistical behavior as a function of the averaging length and time scales. We test the model with radar and gauge data collected contemporaneously at the NASA TRMM ground validation sites located near Melbourne, Florida and on the Kwajalein Atoll, Marshall Islands in the tropical Pacific. We estimate the parameters by tuning them to fit the second moment statistics of radar data at the smaller spatiotemporal scales. The model predictions are then found to fit the second moment statistics of the gauge data reasonably well at these scales without any further adjustment.
Why do high-redshift galaxies show diverse gas-phase metallicity gradients?
NASA Astrophysics Data System (ADS)
Ma, Xiangcheng; Hopkins, Philip F.; Feldmann, Robert; Torrey, Paul; Faucher-Giguère, Claude-André; Kereš, Dušan
2017-04-01
Recent spatially resolved observations of galaxies at z ˜ 0.6-3 reveal that high-redshift galaxies show complex kinematics and a broad distribution of gas-phase metallicity gradients. To understand these results, we use a suite of high-resolution cosmological zoom-in simulations from the Feedback in Realistic Environments project, which include physically motivated models of the multiphase interstellar medium, star formation and stellar feedback. Our simulations reproduce the observed diversity of kinematic properties and metallicity gradients, broadly consistent with observations at z ˜ 0-3. Strong negative metallicity gradients only appear in galaxies with a rotating disc, but not all rotationally supported galaxies have significant gradients. Strongly perturbed galaxies with little rotation always have flat gradients. The kinematic properties and metallicity gradient of a high-redshift galaxy can vary significantly on short time-scales, associated with starburst episodes. Feedback from a starburst can destroy the gas disc, drive strong outflows and flatten a pre-existing negative metallicity gradient. The time variability of a single galaxy is statistically similar to the entire simulated sample, indicating that the observed metallicity gradients in high-redshift galaxies reflect the instantaneous state of the galaxy rather than the accretion and growth history on cosmological time-scales. We find weak dependence of metallicity gradient on stellar mass and specific star formation rate (sSFR). Low-mass galaxies and galaxies with high sSFR tend to have flat gradients, likely due to the fact that feedback is more efficient in these galaxies. We argue that it is important to resolve feedback on small scales in order to produce the diverse metallicity gradients observed.
The use of higher-order statistics in rapid object categorization in natural scenes.
Banno, Hayaki; Saiki, Jun
2015-02-04
We can rapidly and efficiently recognize many types of objects embedded in complex scenes. What information supports this object recognition is a fundamental question for understanding our visual processing. We investigated the eccentricity-dependent role of shape and statistical information for ultrarapid object categorization, using the higher-order statistics proposed by Portilla and Simoncelli (2000). Synthesized textures computed by their algorithms have the same higher-order statistics as the originals, while the global shapes were destroyed. We used the synthesized textures to manipulate the availability of shape information separately from the statistics. We hypothesized that shape makes a greater contribution to central vision than to peripheral vision and that statistics show the opposite pattern. Results did not show contributions clearly biased by eccentricity. Statistical information demonstrated a robust contribution not only in peripheral but also in central vision. For shape, the results supported the contribution in both central and peripheral vision. Further experiments revealed some interesting properties of the statistics. They are available for a limited time, attributable to the presence or absence of animals without shape, and predict how easily humans detect animals in original images. Our data suggest that when facing the time constraint of categorical processing, higher-order statistics underlie our significant performance for rapid categorization, irrespective of eccentricity. © 2015 ARVO.
Learning styles of postgraduate and undergraduate medical students.
Shukr, Irfan; Zainab, Roop; Rana, Mowadat H
2013-01-01
To compare learning styles of undergraduate and postgraduate medical students. Observational, comparative study. Department of Medical Education, Army Medical College, NUST, Rawalpindi, Pakistan, during February and March 2012. A total of 170 students were divided into two equal groups of undergraduate students of Army Medical College, and postgraduate students of Armed Forces Post Graduate Medical Institute, Rawalpindi. Learning Style Questionnaire (LSQ) was used to assess and categorize the participants into Honey and Mumford classification of learning styles. The responses of each student ranging from 'very strong,' 'strong', 'moderate', and 'low' preference towards activist, theorist, reflector and pragmatist learning styles were compiled. The two groups were compared using SPSS version 17, using Fisher's exact test and the chi-square test. A p-value of $lt; 0.05 was considered significant. Preferences for all four learning styles were present in both groups. The results reveal an overall statistically significant difference in the 'very strong' preference in learning styles between the two study groups (p=0.002). Among the undergraduate students, 45% had a very strong preference for being an activist, whereas in postgraduate students, 38% had very strong preference for reflector, and 35% for theorist. This was statistically significant for activist, and reflector, and attained a p-value of < 0.001, for activist, and of 0.018 for reflector. The most uncommon 'very strong', and 'strong preference' for learning style was pragmatist in both undergraduate and postgraduate students. Diversity of learning styles at undergraduate and postgraduate level of medical education calls for multiplicity of instructional and assessment modalities to match them. The learning styles amongst the undergraduate medical students are different from the postgraduates. The postgraduates commonly have the reflector learning style while the undergraduates are predominantly activists and theorists.
Monitoring and Evaluation: Statistical Support for Life-cycle Studies, Annual Report 2003.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Skalski, John
2003-11-01
The ongoing mission of this project is the development of statistical tools for analyzing fisheries tagging data in the most precise and appropriate manner possible. This mission also includes providing statistical guidance on the best ways to design large-scale tagging studies. This mission continues because the technologies for conducting fish tagging studies continuously evolve. In just the last decade, fisheries biologists have seen the evolution from freeze-brands and coded wire tags (CWT) to passive integrated transponder (PIT) tags, balloon-tags, radiotelemetry, and now, acoustic-tags. With each advance, the technology holds the promise of more detailed and precise information. However, the technologymore » for analyzing and interpreting the data also becomes more complex as the tagging techniques become more sophisticated. The goal of the project is to develop the analytical tools in parallel with the technical advances in tagging studies, so that maximum information can be extracted on a timely basis. Associated with this mission is the transfer of these analytical capabilities to the field investigators to assure consistency and the highest levels of design and analysis throughout the fisheries community. Consequently, this project provides detailed technical assistance on the design and analysis of tagging studies to groups requesting assistance throughout the fisheries community. Ideally, each project and each investigator would invest in the statistical support needed for the successful completion of their study. However, this is an ideal that is rarely if every attained. Furthermore, there is only a small pool of highly trained scientists in this specialized area of tag analysis here in the Northwest. Project 198910700 provides the financial support to sustain this local expertise on the statistical theory of tag analysis at the University of Washington and make it available to the fisheries community. Piecemeal and fragmented support from various agencies and organizations would be incapable of maintaining a center of expertise. The mission of the project is to help assure tagging studies are designed and analyzed from the onset to extract the best available information using state-of-the-art statistical methods. The overarching goals of the project is to assure statistically sound survival studies so that fish managers can focus on the management implications of their findings and not be distracted by concerns whether the studies are statistically reliable or not. Specific goals and objectives of the study include the following: (1) Provide consistent application of statistical methodologies for survival estimation across all salmon life cycle stages to assure comparable performance measures and assessment of results through time, to maximize learning and adaptive management opportunities, and to improve and maintain the ability to responsibly evaluate the success of implemented Columbia River FWP salmonid mitigation programs and identify future mitigation options. (2) Improve analytical capabilities to conduct research on survival processes of wild and hatchery chinook and steelhead during smolt outmigration, to improve monitoring and evaluation capabilities and assist in-season river management to optimize operational and fish passage strategies to maximize survival. (3) Extend statistical support to estimate ocean survival and in-river survival of returning adults. Provide statistical guidance in implementing a river-wide adult PIT-tag detection capability. (4) Develop statistical methods for survival estimation for all potential users and make this information available through peer-reviewed publications, statistical software, and technology transfers to organizations such as NOAA Fisheries, the Fish Passage Center, US Fish and Wildlife Service, US Geological Survey (USGS), US Army Corps of Engineers (USACE), Public Utility Districts (PUDs), the Independent Scientific Advisory Board (ISAB), and other members of the Northwest fisheries community. (5) Provide and maintain statistical software for tag analysis and user support. (6) Provide improvements in statistical theory and software as requested by user groups. These improvements include extending software capabilities to address new research issues, adapting tagging techniques to new study designs, and extending the analysis capabilities to new technologies such as radio-tags and acoustic-tags.« less
Intermittency in generalized NLS equation with focusing six-wave interactions
NASA Astrophysics Data System (ADS)
Agafontsev, D. S.; Zakharov, V. E.
2015-10-01
We study numerically the statistics of waves for generalized one-dimensional Nonlinear Schrödinger (NLS) equation that takes into account focusing six-wave interactions, dumping and pumping terms. We demonstrate the universal behavior of this system for the region of parameters when six-wave interactions term affects significantly only the largest waves. In particular, in the statistically steady state of this system the probability density function (PDF) of wave amplitudes turns out to be strongly non-Rayleigh one for large waves, with characteristic "fat tail" decaying with amplitude | Ψ | close to ∝ exp (- γ | Ψ |), where γ > 0 is constant. The corresponding non-Rayleigh addition to the PDF indicates strong intermittency, vanishes in the absence of six-wave interactions, and increases with six-wave coupling coefficient.
... Search Form Controls Cancel Submit Search the CDC Gonorrhea Note: Javascript is disabled or is not supported ... Twitter STD on Facebook Sexually Transmitted Diseases (STDs) Gonorrhea Statistics Recommend on Facebook Tweet Share Compartir Gonorrhea ...
ERIC Educational Resources Information Center
Foley, Gregory D.; Khoshaim, Heba Bakr; Alsaeed, Maha; Er, S. Nihan
2012-01-01
Attending professional development programmes can support teachers in applying new strategies for teaching mathematics and statistics. This study investigated (a) the extent to which the participants in a professional development programme subsequently used the techniques they had learned when teaching mathematics and statistics and (b) the…
Fixed and mobile-bearing total ankle prostheses: Effect on tibial bone strain.
Terrier, Alexandre; Fernandes, Caroline Sieger; Guillemin, Maïka; Crevoisier, Xavier
2017-10-01
Total ankle replacement is associated to a high revision rate. To improve implant survival, the potential advantage of prostheses with fixed bearing compared to mobile bearing is unclear. The objective of this study was to test the hypothesis that fixed and mobile bearing prostheses are associated with different biomechanical quantities typically associated to implant failure. With a validated finite element model, we compared three cases: a prosthesis with a fixed bearing, a prosthesis with a mobile bearing in a centered position, and a prosthesis with mobile bearing in an eccentric position. Both prostheses were obtained from the same manufacturer. They were tested on seven tibias with maximum axial compression force during walking. We tested the hypothesis that there was a difference of bone strain, bone-implant interfacial stress, and bone support between the three cases. We also evaluated, for the three cases, the correlations between bone support, bone strain and bone-implant interfacial stress. There were no statistically significant differences between the three cases. Overall, bone support was mainly trabecular, and less effective in the posterior side. Bone strain and bone-implant interfacial stress were strongly correlated to bone support. Even if slight differences are observed between fixed and mobile bearing, it is not enough to put forward the superiority of one of these implants regarding their reaction to axial compression. When associated to the published clinical results, our study provides no argument to warn surgeons against the use of two-components fixed bearing implants. Copyright © 2017 Elsevier Ltd. All rights reserved.
A Culture Conducive to Women’s Academic Success: Development of a Measure
Westring, Alyssa Friede; Speck, Rebecca M.; Sammel, Mary Dupuis; Scott, Patricia; Tuton, Lucy Wolf; Grisso, Jeane Ann; Abbuhl, Stephanie
2012-01-01
Purpose The culture of the work environment inhibits women’s career success in academic medicine. The lack of clarity and consistency in the definition, measurement, and analysis of culture constrains current research on the topic. The authors addressed this gap by defining the construct of a culture conducive to women’s academic success (CCWAS) and creating a measure (i.e., tool) to evaluate it. Method First, the authors conducted a review of published literature, held focus groups, and consulted with subject matter experts to develop a measure of academic workplace culture for women. Then they developed and pilot-tested the measure with a convenience sample of women assistant professors. After refining the measure, they administered it, along with additional scales for validation, to 133 women assistant professors at the University of Pennsylvania. Finally, they conducted statistical analyses to explore the measure’s nature and validity. Results A CCWAS consists of four distinct, but related dimensions: equal access, work-life balance, freedom from gender biases, and supportive leadership. The authors found evidence that women within departments/divisions agree on the supportiveness of their units but that substantial differences among units exist. The analyses provided strong evidence for the reliability and validity of their measure. Conclusions This report contributes to a growing understanding of women’s academic medicine careers and provides a measure that researchers can utilize to assess the supportiveness of the culture for women assistant professors and that leaders can use to evaluate the effectiveness of interventions designed to increase the supportiveness of the environment for women faculty. PMID:23018337
How Many Graduating Family Medicine Residents Have Chosen Financial Support for Service Commitments?
Phillips, Julie; Peterson, Lars E; Fang, Bo; Kovar-Gough, Iris; Phillips, Robert L
2017-09-01
New family physicians have opportunities to avoid accruing educational debt or have loans repaid by making a commitment to public service. Little information is available about the numbers of early career family physicians who have made service commitments to fund their education. The purpose of this study is to describe the proportion of graduating family medicine residents who have enrolled in US military and National Health Service Corps (NHSC) scholarship and loan repayment programs, thus obligating them to future public service. The study was a secondary analysis of de-identified data from the 2014 and 2015 American Board of Family Medicine examination registration questionnaire, which is required of all residents applying for board certification. Descriptive statistics were used to indicate the numbers and proportions of respondents who indicated military or NHSC financial support. Chi square analyses were used to analyze differences between groups. Of the 6,231 residents studied, 271 (4.4%) had either obtained military support (n=191, 3.1%) or enrolled in the NHSC (n=80, 1.3%). More men had enrolled in the military than women (4.2% vs 2.2%, P<0.01), but there was no significant NHSC gender difference. Underrepresented minorities (URM) were twice as likely to have enrolled in NHSC as non-URM residents (2.5% vs 1.0%, P<0.01). Only a small fraction of graduating family medicine residents have used either military enrollment or NHSC scholarships to fund their education. Family medicine should advocate strongly for expansion of the NHSC scholarship program, which receives many more applications than it can support.
Li, Xing-Ming; Yuan, Xiao-Qing; Wang, Jun-Jie; Zhang, Wan-Ying; Zhou, Yang; Liu, Gu-Ning
2017-02-01
Our study was conducted to further investigate the model of social support and care for People Living with HIV/AIDS(PLHA), to explore their role in People Living with AIDS's quality of life (QOL) as reference for improving nursing policies for AIDS. Social support and care are the most important factors impacting the QOL of People Living with HIV/AIDS, but most studies conducted upon the influence of social support and QOL of People Living with HIV/AIDS are mainly based on cross-sectional design. Our study was a nonrandomised controlled community intervention study. The participants diagnosed as People Living with HIV/AIDS at Beijing You An Hospital received a comprehensive social support care from December 2013 to December 2014. To evaluate the impact of social support and care model on People Living with HIV/AIDS, our study analysed the different dimension scores of social support scale and quality of life before and after the intervention. Correlation between the net benefit value of social support and that of QOL from various dimensions were analysed. There were significant differences in the score of objective support and usage of support (all p = 0·02) for social support. Net values of objective support score and usage of support were 0·25 and 0·19, respectively, after intervention. There were significant differences in physiological function, role physical, general health, vitality, social function, mental health, health transition and total score of quality of life (all p < 0·05). The canonical correlation analysis of net values of social support and QOL indicated that the first and second canonical correlation were statistically significant, with correlation coefficients of 0·53 (p = 0·00) and 0·21 (p = 0·04). Social support and care intervention model can effectively improve perceived subjective feeling on social support and QOL condition for People Living with HIV/AIDS. And strategies to improve social support and care intervention programmes are strongly encouraged. The method is simple and cost-effective and could be a way to improve the quality of life condition for People Living with HIV/AIDS. © 2016 John Wiley & Sons Ltd.
13 CFR 301.8 - Application evaluation criteria.
Code of Federal Regulations, 2013 CFR
2013-01-01
... private sector investment resulting from an Investment. (b) Has strong organizational leadership. An Investment will have strong leadership, relevant Project management experience and a significant commitment... leadership and support by local elected officials; and (3) Strong cooperation among the business sector...
13 CFR 301.8 - Application evaluation criteria.
Code of Federal Regulations, 2014 CFR
2014-01-01
... private sector investment resulting from an Investment. (b) Has strong organizational leadership. An Investment will have strong leadership, relevant Project management experience and a significant commitment... leadership and support by local elected officials; and (3) Strong cooperation among the business sector...
13 CFR 301.8 - Application evaluation criteria.
Code of Federal Regulations, 2012 CFR
2012-01-01
... private sector investment resulting from an Investment. (b) Has strong organizational leadership. An Investment will have strong leadership, relevant Project management experience and a significant commitment... leadership and support by local elected officials; and (3) Strong cooperation among the business sector...
Structural and Acidic Properties of Niobia-Silica and Niobia-Alumina Aerogels
1991-05-06
some weak Bronsted acidity. The silica aerogel supported niobia samples also had strong Lewis acidity as well as strong iv Bronsted acidity which was...NS25w or the silica aerogel supported niobia because of the formation of a distorted octahedral niobia-rigid silica interface. Isomerization of 1...67 2.1.2 Silica Aerogel .......................................................... 70 2.1.3 Alumina