Does Biodiversity-Ecosystem Function Literature Neglect Tropical Ecosystems?

PubMed

Clarke, David A; York, Paul H; Rasheed, Michael A; Northfield, Tobin D

2017-05-01

Current evidence suggests that there is a positive relationship between biodiversity and ecosystem functioning, but few studies have addressed tropical ecosystems where the highest levels of biodiversity occur. We develop two hypotheses for the implications of generalizing from temperate studies to tropical ecosystems, and discuss the need for more tropical research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Traditional fire-use, landscape transition, and the legacies of social theory past.

PubMed

Coughlan, Michael R

2015-12-01

Fire-use and the scale and character of its effects on landscapes remain hotly debated in the paleo- and historical-fire literature. Since the second half of the nineteenth century, anthropology and geography have played important roles in providing theoretical propositions and testable hypotheses for advancing understandings of the ecological role of human-fire-use in landscape histories. This article reviews some of the most salient and persistent theoretical propositions and hypotheses concerning the role of humans in historical fire ecology. The review discusses this history in light of current research agendas, such as those offered by pyrogeography. The review suggests that a more theoretically cognizant historical fire ecology should strive to operationalize transdisciplinary theory capable of addressing the role of human variability in the evolutionary history of landscapes. To facilitate this process, researchers should focus attention on integrating more current human ecology theory into transdisciplinary research agendas.

A population on the rise: The origin of deepwater sculpin in Lake Ontario

USGS Publications Warehouse

Welsh, Amy B.; Scribner, Kim T.; Stott, Wendylee; Walsh, Maureen

2017-01-01

Deepwater sculpin, Myoxocephalus thompsonii, were thought to have been extirpated from Lake Ontario. However, in recent years, abundance has increased and recruitment has been documented. There are two hypotheses concerning the origin of the current Lake Ontario deepwater sculpin population. First, individuals from the upper Great Lakes may have recolonized Lake Ontario. Alternatively, the Lake Ontario population may have not been extirpated, and the remnant population has recovered naturally. To test these hypotheses, eight microsatellite loci were used to analyze samples from the current Lake Ontario population, museum specimens from the historic Lake Ontario population, and current upper Great Lakes populations. The genetic data suggest that historically throughout the Great Lakes, deepwater sculpin exhibited low levels of spatial genetic structure. Approximate Bayesian Computation analyses support the hypothesis that the current Lake Ontario population is more closely related to populations in the upper Great Lakes than to the historic Lake Ontario samples, indicating that the current Lake Ontario population likely resulted from recolonization from the Upper Great Lakes. The current Lake Ontario population has reduced allelic diversity relative to upper Great Lakes populations, indicating a possible founder effect. This study demonstrates the role life history variation can play in recolonization success. The pelagic larval phase of the deepwater sculpin allowed recolonization of Lake Ontario via passive larval drift.

Helminths and HIV infection: epidemiological observations on immunological hypotheses

PubMed Central

BROWN, M; MAWA, P A; KALEEBU, P; ELLIOTT, A M

2006-01-01

Parasitic helminths have co-evolved with the mammalian immune system. Current hypotheses suggest that immunological stimulation in the presence of helminths is balanced by immuno-regulation and by the broad spectrum of mechanisms possessed by helminths for countering the host immune response. The degree to which this balance is perfected, and the mechanisms by which this is achieved, vary between helminth species; we suggest that this is reflected not only in the degree of pathology induced by helminths but also in a variety of relationships with HIV infection and HIV disease. Available epidemiological data regarding interactions between helminths and HIV are largely observational; results are variable and generally inconclusive. Well designed, controlled intervention studies are required to provide definitive information on the species-specific nature of these interactions and on the advantages, disadvantages and optimal timing of de-worming in relation to HIV infection. PMID:17042933

Commentary: Cause for Alarm? Youth and Internet Risk Research--A Commentary on Livingstone and Smith (2014)

ERIC Educational Resources Information Center

Finkelhor, David

2014-01-01

This commentary on Livingstone and Smith (2014) suggests that more attention should be paid to a set of hypotheses about technology that contrasts with those that have animated much of the current research interest: (a) That the digital environment is no more perilous and perhaps less perilous than other offline environments youth inhabit; (b)…

REVIEWS OF TOPICAL PROBLEMS: On the nature of cosmic gamma-ray bursts

NASA Astrophysics Data System (ADS)

Luchkov, B. I.; Mitrofanov, I. G.; Rozental', I. L.

1996-07-01

Current hypotheses of gamma-ray burst origin are analysed. About 30 years after their discovery, it is still unclear where gamma-ray bursts are created (Solar system, Galaxy or Metagalaxy). Nor is the mechanism of their production known. This paper reviews on-going gamma-ray experiments and suggests possible lines of further studies on their origin.

Chronic and Acute Stress Promote Overexploitation in Serial Decision Making

PubMed Central

Lenow, Jennifer K.; Constantino, Sara M.

2017-01-01

Many decisions that humans make resemble foraging problems in which a currently available, known option must be weighed against an unknown alternative option. In such foraging decisions, the quality of the overall environment can be used as a proxy for estimating the value of future unknown options against which current prospects are compared. We hypothesized that such foraging-like decisions would be characteristically sensitive to stress, a physiological response that tracks biologically relevant changes in environmental context. Specifically, we hypothesized that stress would lead to more exploitative foraging behavior. To test this, we investigated how acute and chronic stress, as measured by changes in cortisol in response to an acute stress manipulation and subjective scores on a questionnaire assessing recent chronic stress, relate to performance in a virtual sequential foraging task. We found that both types of stress bias human decision makers toward overexploiting current options relative to an optimal policy. These findings suggest a possible computational role of stress in decision making in which stress biases judgments of environmental quality. SIGNIFICANCE STATEMENT Many of the most biologically relevant decisions that we make are foraging-like decisions about whether to stay with a current option or search the environment for a potentially better one. In the current study, we found that both acute physiological and chronic subjective stress are associated with greater overexploitation or staying at current options for longer than is optimal. These results suggest a domain-general way in which stress might bias foraging decisions through changing one's appraisal of the overall quality of the environment. These novel findings not only have implications for understanding how this important class of foraging decisions might be biologically implemented, but also for understanding the computational role of stress in behavior and cognition more broadly. PMID:28483979

Explanatory pluralism: An unrewarding prediction error for free energy theorists.

PubMed

Colombo, Matteo; Wright, Cory

2017-03-01

Courtesy of its free energy formulation, the hierarchical predictive processing theory of the brain (PTB) is often claimed to be a grand unifying theory. To test this claim, we examine a central case: activity of mesocorticolimbic dopaminergic (DA) systems. After reviewing the three most prominent hypotheses of DA activity-the anhedonia, incentive salience, and reward prediction error hypotheses-we conclude that the evidence currently vindicates explanatory pluralism. This vindication implies that the grand unifying claims of advocates of PTB are unwarranted. More generally, we suggest that the form of scientific progress in the cognitive sciences is unlikely to be a single overarching grand unifying theory. Copyright © 2016 Elsevier Inc. All rights reserved.

Mindfulness-based treatment to prevent addictive behavior relapse: theoretical models and hypothesized mechanisms of change.

PubMed

Witkiewitz, Katie; Bowen, Sarah; Harrop, Erin N; Douglas, Haley; Enkema, Matthew; Sedgwick, Carly

2014-04-01

Mindfulness-based treatments are growing in popularity among addiction treatment providers, and several studies suggest the efficacy of incorporating mindfulness practices into the treatment of addiction, including the treatment of substance use disorders and behavioral addictions (i.e., gambling). The current paper provides a review of theoretical models of mindfulness in the treatment of addiction and several hypothesized mechanisms of change. We provide an overview of mindfulness-based relapse prevention (MBRP), including session content, treatment targets, and client feedback from participants who have received MBRP in the context of empirical studies. Future research directions regarding operationalization and measurement, identifying factors that moderate treatment effects, and protocol adaptations for specific populations are discussed.

Interaction of language, auditory and memory brain networks in auditory verbal hallucinations.

PubMed

Ćurčić-Blake, Branislava; Ford, Judith M; Hubl, Daniela; Orlov, Natasza D; Sommer, Iris E; Waters, Flavie; Allen, Paul; Jardri, Renaud; Woodruff, Peter W; David, Olivier; Mulert, Christoph; Woodward, Todd S; Aleman, André

2017-01-01

Auditory verbal hallucinations (AVH) occur in psychotic disorders, but also as a symptom of other conditions and even in healthy people. Several current theories on the origin of AVH converge, with neuroimaging studies suggesting that the language, auditory and memory/limbic networks are of particular relevance. However, reconciliation of these theories with experimental evidence is missing. We review 50 studies investigating functional (EEG and fMRI) and anatomic (diffusion tensor imaging) connectivity in these networks, and explore the evidence supporting abnormal connectivity in these networks associated with AVH. We distinguish between functional connectivity during an actual hallucination experience (symptom capture) and functional connectivity during either the resting state or a task comparing individuals who hallucinate with those who do not (symptom association studies). Symptom capture studies clearly reveal a pattern of increased coupling among the auditory, language and striatal regions. Anatomical and symptom association functional studies suggest that the interhemispheric connectivity between posterior auditory regions may depend on the phase of illness, with increases in non-psychotic individuals and first episode patients and decreases in chronic patients. Leading hypotheses involving concepts as unstable memories, source monitoring, top-down attention, and hybrid models of hallucinations are supported in part by the published connectivity data, although several caveats and inconsistencies remain. Specifically, possible changes in fronto-temporal connectivity are still under debate. Precise hypotheses concerning the directionality of connections deduced from current theoretical approaches should be tested using experimental approaches that allow for discrimination of competing hypotheses. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Fourier power, subjective distance, and object categories all provide plausible models of BOLD responses in scene-selective visual areas

PubMed Central

Lescroart, Mark D.; Stansbury, Dustin E.; Gallant, Jack L.

2015-01-01

Perception of natural visual scenes activates several functional areas in the human brain, including the Parahippocampal Place Area (PPA), Retrosplenial Complex (RSC), and the Occipital Place Area (OPA). It is currently unclear what specific scene-related features are represented in these areas. Previous studies have suggested that PPA, RSC, and/or OPA might represent at least three qualitatively different classes of features: (1) 2D features related to Fourier power; (2) 3D spatial features such as the distance to objects in a scene; or (3) abstract features such as the categories of objects in a scene. To determine which of these hypotheses best describes the visual representation in scene-selective areas, we applied voxel-wise modeling (VM) to BOLD fMRI responses elicited by a set of 1386 images of natural scenes. VM provides an efficient method for testing competing hypotheses by comparing predictions of brain activity based on encoding models that instantiate each hypothesis. Here we evaluated three different encoding models that instantiate each of the three hypotheses listed above. We used linear regression to fit each encoding model to the fMRI data recorded from each voxel, and we evaluated each fit model by estimating the amount of variance it predicted in a withheld portion of the data set. We found that voxel-wise models based on Fourier power or the subjective distance to objects in each scene predicted much of the variance predicted by a model based on object categories. Furthermore, the response variance explained by these three models is largely shared, and the individual models explain little unique variance in responses. Based on an evaluation of previous studies and the data we present here, we conclude that there is currently no good basis to favor any one of the three alternative hypotheses about visual representation in scene-selective areas. We offer suggestions for further studies that may help resolve this issue. PMID:26594164

Denning behaviour of non-gravid wolves, Canis lupus

USGS Publications Warehouse

Mech, L.D.; Phillips, M.K.; Smith, D.W.; Kreeger, T.J.

1996-01-01

Wild wolves (Canis lupus) that had produced pups in earlier years but were not currently pregnant, and ovariectomized captive wolves, dug dens during and after the whelping season even though they produced no pups. These observations suggest that den digging is not a function of pregnancy or of ovarian estrogen or progesterone. We hypothesize that increasing prolactin in spring elicits or mediates den-digging behavior.

Forgiveness and justice: a research agenda for social and personality psychology.

PubMed

Exline, Julie Juola; Worthington, Everett L; Hill, Peter; McCullough, Michael E

2003-01-01

Forgiveness and related constructs (e.g., repentance, mercy, reconciliation) are ripe for study by social and personality psychologists, including those interested in justice. Current trends in social science, law, management, philosophy, and theology suggest a need to expand existing justice frameworks to incorporate alternatives or complements to retribution, including forgiveness and related processes. In this article, we raise five challenging empirical questions about forgiveness. For each question, we briefly review representative research, raise hypotheses, and suggest specific ways in which social and personality psychologists could make distinctive contributions.

A new perspective on the growth pattern of the Wandering Albatross (Diomedea exulans) through DEB theory

NASA Astrophysics Data System (ADS)

Teixeira, Carlos M. G. L.; Sousa, Tânia; Marques, Gonçalo M.; Domingos, Tiago; Kooijman, Sebastiaan A. L. M.

2014-11-01

The Wandering Albatross (Diomedea exulans) and other seabirds exhibit a growing pattern that includes a period of body mass decrease before fledging. Several hypotheses have been suggested to explain it without success. We hypothesized that: 1) chicks and adults have similar metabolic traits regulating assimilation, growth and maturation; 2) there is a difference in locomotion effort between chicks and adults, and 3) chicks are exposed to a decline in food availability before fledging. This set of hypotheses allows for an energy surplus to be available and stored in reserve during the first months of development, explaining the mass recession that starts before fledging and the fact that adults keep a lower weight than fledglings, throughout the rest of their life span. To test this set of hypotheses we applied the Dynamic Energy Budget (DEB) theory. Using a small set of life-history traits and growth curves we parameterized the DEB standard model. We confirmed this set of hypotheses and estimated the pattern of decline in food availability that explains mass recession. An assessment of the daily energy intake was also performed. The implications related to that energy flux and diet composition are discussed based on current knowledge. The DEB model for the Wandering Albatross also provided estimates for the adult daily food ingested by adults (464.06 kJ kg- 1 d- 1), fasting capacity (25 d), Field Metabolic Rate (4.29 W kg- 1) and resting metabolic rate (2.87 W kg- 1). These values are consistent with the averages obtained in the field, suggesting that DEB may be useful to provide good estimations on a broader scale.

Mindfulness-Based Treatment to Prevent Addictive Behavior Relapse: Theoretical Models and Hypothesized Mechanisms of Change

PubMed Central

Witkiewitz, Katie; Bowen, Sarah; Harrop, Erin N.; Douglas, Haley; Enkema, Matthew; Sedgwick, Carly

2017-01-01

Mindfulness-based treatments are growing in popularity among addiction treatment providers, and several studies suggest the efficacy of incorporating mindfulness practices into the treatment of addiction, including the treatment of substance use disorders and behavioral addictions (i.e., gambling). The current paper provides a review of theoretical models of mindfulness in the treatment of addiction and several hypothesized mechanisms of change. We provide an overview of mindfulness-based relapse prevention (MBRP), including session content, treatment targets, and client feedback from participants who have received MBRP in the context of empirical studies. Future research directions regarding operationalization and measurement, identifying factors that moderate treatment effects, and protocol adaptations for specific populations are discussed. PMID:24611847

[Power metabolism from neurons and a glia to the whole brain: norm, pathology and correction].

PubMed

Zil'berter, Iu I; Zil'berter, T M

2012-01-01

The review outlines current state of the thepretical, methodological and applies aspects of brain's energy homeostasis. Authors suggest reconsidering the exclusive role of glucose as an energy substrate (ES) at both neuronal and systemic levels discussing recent research data on qualitative composition of ES pool in the brain. The role of ES alternative to glucose, e.g., lactate and ketone bodies, is examined. The hypotheses of intracellular and astrocyte-neuron lactate shuttles are discussed along with the hypotheses of astrocyte-neuron shuttle of ketone bodies, the selfish brain theory and suppositions on homeostatic versus non-homeostatic ES supply chains. In conclusion, authors argue that exogenous native ES may be used for prevention and treatment of neurodegenerative diseases.

La Grippe and World War I: conflict participation and pandemic confrontation.

PubMed

Steele, B J; Collins, C D

2009-01-01

This paper assesses whether a nation-state's participation in conflict influences its ability to confront global pandemic or disease. Two alternative hypotheses are proposed. First, increased levels of conflict participation lead to increased abilities of states to confront pandemics. A second and alternative hypothesis is that increased conflict participation decreases the ability of states to confront pandemics. The hypotheses are tested through the ultimate case of war and pandemic: the 1918 Influenza pandemic (Spanish Flu or 'La Grippe') that killed 20-100 million people worldwide. Using simple correlation and case illustrations, we test these hypotheses with special focus upon the ability of the participant countries to confront the pandemic. The findings suggest, in a limited and varied fashion, that while neutral countries enjoyed the lowest levels of pandemic deaths, of the participant countries greater levels of conflict participation correlate with lower levels of pandemic deaths. The paper concludes with some propositions regarding the relationship between the current 'war on terror' and prospective pandemics such as avian flu.

The role of orexin-A in food motivation, reward-based feeding behavior and food-induced neuronal activation in rats.

PubMed

Choi, D L; Davis, J F; Fitzgerald, M E; Benoit, S C

2010-04-28

Consumption beyond homeostatic needs, referred to here as reward-based feeding behavior, is a central contributor to the current obesity epidemic worldwide. Importantly, reward-based feeding can be driven by palatability, the taste and texture of the food, as well as cues associated with the consumption of palatable foods. The hypothalamic orexin system regulates both diet preference and anticipation of food rewards making it a likely target to modulate reward-based feeding behavior. In the current manuscript we hypothesized that orexin signaling mediates food-motivated behaviors and reward-based feeding behavior. We further hypothesized that orexin neurons and targets of the orexin system become activated in response to cues associated with the consumption of palatable food. Data from these studies suggest that orexin signaling promotes progressive ratio responding for palatable foods while blockade of orexin signaling attenuates reward-based feeding of a high fat diet. In addition, cues linked to the consumption of chocolate, or the receipt of a daily meal, activate the orexin system and its target regions differentially. Collectively, these data suggest that orexin signaling mediates reward-based feeding behavior and, within specific target regions, may regulate cue-induced overconsumption of palatable foods. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Asthma in the United States: burden and current theories.

PubMed

Redd, Stephen C

2002-08-01

Asthma has emerged as a major public health problem in the United States over the past 20 years. Currently, nearly 15 million Americans have asthma, including almost 5 million children. The number of asthma cases has more than doubled since 1980. Approximately 5,500 persons die from asthma each year, and rates have increased over the past 20 years. Rates of death, hospitalization, and emergency department visits are 2-3 times higher among African Americans than among white Americans. The costs of asthma have also increased to 12.7 billion dollars in 1998. Both lifestyle and environmental hypotheses have been invoked to explain the increase in asthma prevalence. Several studies have examined the relationship of obesity and asthma and found associations suggesting that obesity predisposes to the development of asthma. Some studies have found that day care attendance and having older siblings protect against the development of asthma. This observation has led investigators to hypothesize that increased exposure to microbial agents might protect against asthma (the hygiene hypothesis). Environmental exposures found to predispose to asthma include house dust mite allergen and environmental tobacco smoke. Although current knowledge does not permit definitive conclusions about the causes of asthma onset, better adherence to current recommendations for medical therapy and environmental management of asthma would reduce the burden of this disease.

Legacies of precipitation fluctuations on primary production: theory and data synthesis.

PubMed

Sala, Osvaldo E; Gherardi, Laureano A; Reichmann, Lara; Jobbágy, Esteban; Peters, Debra

2012-11-19

Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we propose a theory of controls of ANPP based on four hypotheses about legacies of wet and dry years that explains space versus time differences in ANPP-precipitation relationships. We tested the hypotheses using 16 long-term series of ANPP. We found that legacies revealed by the association of current- versus previous-year conditions through the temporal series occur across all ecosystem types from deserts to mesic grasslands. Therefore, previous-year precipitation and ANPP control a significant fraction of current-year production. We developed unified models for the controls of ANPP through space and time. The relative importance of current-versus previous-year precipitation changes along a gradient of mean annual precipitation with the importance of current-year PPT decreasing, whereas the importance of previous-year PPT remains constant as mean annual precipitation increases. Finally, our results suggest that ANPP will respond to climate-change-driven alterations in water availability and, more importantly, that the magnitude of the response will increase with time.

Evaluating Infection Prevention Strategies in Out-Patient Dialysis Units Using Agent-Based Modeling.

PubMed

Wares, Joanna R; Lawson, Barry; Shemin, Douglas; D'Agata, Erika M C

2016-01-01

Patients receiving chronic hemodialysis (CHD) are among the most vulnerable to infections caused by multidrug-resistant organisms (MDRO), which are associated with high rates of morbidity and mortality. Current guidelines to reduce transmission of MDRO in the out-patient dialysis unit are targeted at patients considered to be high-risk for transmitting these organisms: those with infected skin wounds not contained by a dressing, or those with fecal incontinence or uncontrolled diarrhea. Here, we hypothesize that targeting patients receiving antimicrobial treatment would more effectively reduce transmission and acquisition of MDRO. We also hypothesize that environmental contamination plays a role in the dissemination of MDRO in the dialysis unit. To address our hypotheses, we built an agent-based model to simulate different treatment strategies in a dialysis unit. Our results suggest that reducing antimicrobial treatment, either by reducing the number of patients receiving treatment or by reducing the duration of the treatment, markedly reduces overall colonization rates and also the levels of environmental contamination in the dialysis unit. Our results also suggest that improving the environmental decontamination efficacy between patient dialysis treatments is an effective method for reducing colonization and contamination rates. These findings have important implications for the development and implementation of future infection prevention strategies.

Opposing effects of oxidative challenge and carotenoids on antioxidant status and condition-dependent sexual signalling

PubMed Central

Tomášek, Oldřich; Gabrielová, Barbora; Kačer, Petr; Maršík, Petr; Svobodová, Jana; Syslová, Kamila; Vinkler, Michal; Albrecht, Tomáš

2016-01-01

Several recent hypotheses consider oxidative stress to be a primary constraint ensuring honesty of condition-dependent carotenoid-based signalling. The key testable difference between these hypotheses is the assumed importance of carotenoids for redox homeostasis, with carotenoids being either antioxidant, pro-oxidant or unimportant. We tested the role of carotenoids in redox balance and sexual signalling by exposing adult male zebra finches (Taeniopygia guttata) to oxidative challenge (diquat dibromide) and manipulating carotenoid intake. As the current controversy over the importance of carotenoids as antioxidants could stem from the hydrophilic basis of commonly-used antioxidant assays, we used the novel measure of in vivo lipophilic antioxidant capacity. Oxidative challenge reduced beak pigmentation but elicited an increase in antioxidant capacity suggesting resource reallocation from signalling to redox homeostasis. Carotenoids counteracted the effect of oxidative challenge on lipophilic (but not hydrophilic) antioxidant capacity, thereby supporting carotenoid antioxidant function in vivo. This is inconsistent with hypotheses proposing that signalling honesty is maintained through either ROS-induced carotenoid degradation or the pro-oxidant effect of high levels of carotenoid-cleavage products acting as a physiological handicap. Our data further suggest that assessment of lipophilic antioxidant capacity is necessary to fully understand the role of redox processes in ecology and evolution. PMID:27000655

Opposing effects of oxidative challenge and carotenoids on antioxidant status and condition-dependent sexual signalling.

PubMed

Tomášek, Oldřich; Gabrielová, Barbora; Kačer, Petr; Maršík, Petr; Svobodová, Jana; Syslová, Kamila; Vinkler, Michal; Albrecht, Tomáš

2016-03-22

Several recent hypotheses consider oxidative stress to be a primary constraint ensuring honesty of condition-dependent carotenoid-based signalling. The key testable difference between these hypotheses is the assumed importance of carotenoids for redox homeostasis, with carotenoids being either antioxidant, pro-oxidant or unimportant. We tested the role of carotenoids in redox balance and sexual signalling by exposing adult male zebra finches (Taeniopygia guttata) to oxidative challenge (diquat dibromide) and manipulating carotenoid intake. As the current controversy over the importance of carotenoids as antioxidants could stem from the hydrophilic basis of commonly-used antioxidant assays, we used the novel measure of in vivo lipophilic antioxidant capacity. Oxidative challenge reduced beak pigmentation but elicited an increase in antioxidant capacity suggesting resource reallocation from signalling to redox homeostasis. Carotenoids counteracted the effect of oxidative challenge on lipophilic (but not hydrophilic) antioxidant capacity, thereby supporting carotenoid antioxidant function in vivo. This is inconsistent with hypotheses proposing that signalling honesty is maintained through either ROS-induced carotenoid degradation or the pro-oxidant effect of high levels of carotenoid-cleavage products acting as a physiological handicap. Our data further suggest that assessment of lipophilic antioxidant capacity is necessary to fully understand the role of redox processes in ecology and evolution.

GABA neuron alterations, cortical circuit dysfunction and cognitive deficits in schizophrenia.

PubMed

Gonzalez-Burgos, Guillermo; Fish, Kenneth N; Lewis, David A

2011-01-01

Schizophrenia is a brain disorder associated with cognitive deficits that severely affect the patients' capacity for daily functioning. Whereas our understanding of its pathophysiology is limited, postmortem studies suggest that schizophrenia is associated with deficits of GABA-mediated synaptic transmission. A major role of GABA-mediated transmission may be producing synchronized network oscillations which are currently hypothesized to be essential for normal cognitive function. Therefore, cognitive deficits in schizophrenia may result from a GABA synapse dysfunction that disturbs neural synchrony. Here, we highlight recent studies further suggesting alterations of GABA transmission and network oscillations in schizophrenia. We also review current models for the mechanisms of GABA-mediated synchronization of neural activity, focusing on parvalbumin-positive GABA neurons, which are altered in schizophrenia and whose function has been strongly linked to the production of neural synchrony. Alterations of GABA signaling that impair gamma oscillations and, as a result, cognitive function suggest paths for novel therapeutic interventions.

Compositional grading of InxGa1-xAs/GaAs tunnel junctions enhanced by ErAs nanoparticles

NASA Astrophysics Data System (ADS)

Salas, R.; Krivoy, E. M.; Crook, A. M.; Nair, H. P.; Bank, S. R.

2011-10-01

We investigate the electrical conductivity of GaAs-based tunnel junctions enhanced with semimetallic ErAs nanoparticles. In particular, we examine the effects of digitally-graded InGaAs alloys on the n-type side of the tunnel junction, along with different p-type doping levels. Device characteristics of the graded structures indicate that the n-type Schottky barrier may not be the limiting factor in the tunneling current as initially hypothesized. Moreover, significantly improved forward and reverse bias tunneling currents were observed with increased p-type doping, suggesting p-side limitation.

Psychiatric epidemiologic study of occupational lead exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parkinson, D.K.; Ryan, C.; Bromet, E.J.

1986-02-01

The association of occupational lead exposure with neuropsychiatric functioning was evaluated using data collected in 1982 in eastern Pennsylvania from 288 lead-exposed workers and 181 nonexposed subjects. Both current and cumulative exposure indices were used. After controlling for age, education, and income, few meaningful differences between exposed and control workers were found on either neuropsychologic or psychosocial variables. Dose-response analyses indicated that among lead-exposed workers, cumulative and current exposure were unrelated to neuropsychologic performance. The only meaningful associations occurred between exposure and level of conflict in interpersonal relationships. The results thus give evidence against hypotheses suggesting adverse neuropsychologic effects.

The Function and Organization of Lateral Prefrontal Cortex: A Test of Competing Hypotheses

PubMed Central

Reynolds, Jeremy R.; O'Reilly, Randall C.; Cohen, Jonathan D.; Braver, Todd S.

2012-01-01

The present experiment tested three hypotheses regarding the function and organization of lateral prefrontal cortex (PFC). The first account (the information cascade hypothesis) suggests that the anterior-posterior organization of lateral PFC is based on the timing with which cue stimuli reduce uncertainty in the action selection process. The second account (the levels-of-abstraction hypothesis) suggests that the anterior-posterior organization of lateral PFC is based on the degree of abstraction of the task goals. The current study began by investigating these two hypotheses, and identified several areas of lateral PFC that were predicted to be active by both the information cascade and levels-of-abstraction accounts. However, the pattern of activation across experimental conditions was inconsistent with both theoretical accounts. Specifically, an anterior area of mid-dorsolateral PFC exhibited sensitivity to experimental conditions that, according to both accounts, should have selectively engaged only posterior areas of PFC. We therefore investigated a third possible account (the adaptive context maintenance hypothesis) that postulates that both posterior and anterior regions of PFC are reliably engaged in task conditions requiring active maintenance of contextual information, with the temporal dynamics of activity in these regions flexibly tracking the duration of maintenance demands. Activity patterns in lateral PFC were consistent with this third hypothesis: regions across lateral PFC exhibited transient activation when contextual information had to be updated and maintained in a trial-by-trial manner, but sustained activation when contextual information had to be maintained over a series of trials. These findings prompt a reconceptualization of current views regarding the anterior-posterior organization of lateral PFC, but do support other findings regarding the active maintenance role of lateral PFC in sequential working memory paradigms. PMID:22355309

Viewpoint: suggestions for a shift in teaching clinical skills to medical students: the reflective clinical examination.

PubMed

Benbassat, Jochanan; Baumal, Reuben; Heyman, Samuel N; Brezis, Mayer

2005-12-01

How medical students are taught physical examination (PE) skills appears to have changed little since the 1950s. Textbooks are organized according to organ systems and describe methods of eliciting and recording history and PE data using a routine format. In many medical schools, the preclinical teaching programs for clinical examination skills similarly emphasize an orderly collection of data. Teaching students to use diagnostic reasoning is postponed until students have learned history-taking and PE skills. The authors propose three modifications to this educational approach. First, rather than performing the clinical examination using a routine format, students should be encouraged to form diagnostic hypotheses early on while listening to the patient's narrative, and conduct the subsequent search for history and PE data in a reflective way in order to confirm or refute these hypotheses. Second, the authors propose that interviewing patients and conducting the PE be taught by one-on-one tutoring until students achieve mastery. Last, they suggest that the PE be guided not only by students' diagnostic hypotheses, but also by patients' expectations. These modifications are consistent with current trends in medical education that encourage a reflective practice and problem-based learning (PBL), and they also introduce medical students to the precepts of clinical reasoning. The authors suggest that challenging students to seek specific physical findings may increase the likelihood of detecting findings when they are present, and may transform patient interviewing and conducting the PE from routine activities into intellectually exciting experiences.

How Do Theories of Cognition and Consciousness in Ancient Indian Thought Systems Relate to Current Western Theorizing and Research?

PubMed Central

Sedlmeier, Peter; Srinivas, Kunchapudi

2016-01-01

Unknown to most Western psychologists, ancient Indian scriptures contain very rich, empirically derived psychological theories that are, however, intertwined with religious and philosophical content. This article represents our attempt to extract the psychological theory of cognition and consciousness from a prominent ancient Indian thought system: Samkhya-Yoga. We derive rather broad hypotheses from this approach that may complement and extend Western mainstream theorizing. These hypotheses address an ancient personality theory, the effects of practicing the applied part of Samkhya-Yoga on normal and extraordinary cognition, as well as different ways of perceiving reality. We summarize empirical evidence collected (mostly without reference to the Indian thought system) in diverse fields of research that allows for making judgments about the hypotheses, and suggest more specific hypotheses to be examined in future research. We conclude that the existing evidence for the (broad) hypotheses is substantial but that there are still considerable gaps in theory and research to be filled. Theories of cognition contained in the ancient Indian systems have the potential to modify and complement existing Western mainstream accounts of cognition. In particular, they might serve as a basis for arriving at more comprehensive theories for several research areas that, so far, lack strong theoretical grounding, such as meditation research or research on aspects of consciousness. PMID:27014150

Chronic and Acute Stress Promote Overexploitation in Serial Decision Making.

PubMed

Lenow, Jennifer K; Constantino, Sara M; Daw, Nathaniel D; Phelps, Elizabeth A

2017-06-07

Many decisions that humans make resemble foraging problems in which a currently available, known option must be weighed against an unknown alternative option. In such foraging decisions, the quality of the overall environment can be used as a proxy for estimating the value of future unknown options against which current prospects are compared. We hypothesized that such foraging-like decisions would be characteristically sensitive to stress, a physiological response that tracks biologically relevant changes in environmental context. Specifically, we hypothesized that stress would lead to more exploitative foraging behavior. To test this, we investigated how acute and chronic stress, as measured by changes in cortisol in response to an acute stress manipulation and subjective scores on a questionnaire assessing recent chronic stress, relate to performance in a virtual sequential foraging task. We found that both types of stress bias human decision makers toward overexploiting current options relative to an optimal policy. These findings suggest a possible computational role of stress in decision making in which stress biases judgments of environmental quality. SIGNIFICANCE STATEMENT Many of the most biologically relevant decisions that we make are foraging-like decisions about whether to stay with a current option or search the environment for a potentially better one. In the current study, we found that both acute physiological and chronic subjective stress are associated with greater overexploitation or staying at current options for longer than is optimal. These results suggest a domain-general way in which stress might bias foraging decisions through changing one's appraisal of the overall quality of the environment. These novel findings not only have implications for understanding how this important class of foraging decisions might be biologically implemented, but also for understanding the computational role of stress in behavior and cognition more broadly. Copyright © 2017 the authors 0270-6474/17/375681-09$15.00/0.

FHF2 isoforms differentially regulate Nav1.6 mediated resurgent sodium currents in dorsal root ganglion neurons

PubMed Central

Barbosa, Cindy; Xiao, Yucheng; Johnson, Andrew J.; Xie, Wenrui; Strong, Judith A.; Zhang, Jun-Ming; Cummins, Theodore R.

2017-01-01

Nav1.6 and Nav1.6 mediated resurgent currents have been implicated in several pain pathologies. However, our knowledge of how fast resurgent currents are modulated in neurons is limited. Our study explored the potential regulation of Nav1.6 mediated resurgent currents by isoforms of Fibroblast growth Factor Homologous factor 2 (FHF2) in an effort to address the gap in our knowledge. FHF2 isoforms colocalize with Nav1.6 in peripheral sensory neurons. Cell line studies suggest that these proteins differentially regulate inactivation. In particular, FHF2A mediates long-term inactivation, a mechanism proposed to compete with the open-channel blocker mechanism that mediates resurgent currents. On the other hand, FHF2B lacks the ability to mediate long-term inactivation and may delay inactivation favoring open-channel block. Based on these observations, we hypothesized that FHF2A limits resurgent currents, whereas, FHF2B enhances resurgent currents. Overall our results suggest that FHF2A negatively regulates fast resurgent current by enhancing long-term inactivation and delaying recovery. In contrast FHF2B positively regulated resurgent current and did not alter long-term inactivation. Chimeric constructs of FHF2A and Navβ4 (likely the endogenous open channel blocker in sensory neurons) exhibited differential effects on resurgent currents suggesting that specific regions within FHF2A and Navβ4 have important regulatory functions. Our data also indicate FHFAs and FHF2B isoform expression are differentially regulated in a radicular pain model and that associated neuronal hyperexcitability is substantially attenuated by a FHFA peptide. As such, these findings suggest that FHF2A and FHF2B regulate resurgent current in sensory neurons and may contribute to hyperexcitability associated with some pain pathologies. PMID:27999940

Physical Activity, Suicide Risk Factors, and Suicidal Ideation in a Veteran Sample.

PubMed

Gutierrez, Peter M; Davidson, Collin L; Friese, Ariel H; Forster, Jeri E

2016-06-01

The association between current level of suicidal ideation and physical activity was tested in a broad sample of veterans seeking care from the Veterans Health Administration. It was hypothesized that the two variables would be significantly inversely related. It was further hypothesized that the relationship would be mediated by depressive symptoms, disturbed sleep, and a measure of heart rate variability based on existing research regarding physical activity and sleep. Due to the first hypothesis not being supported, the second could not be tested. Post hoc correlation analyses did find associations between physical activity and depressive symptoms, in expected directions, and are discussed. Possible explanations for the negative findings along with recommendations for future research to continue exploring links between suicide risk and physical activity are presented. We conclude by suggesting that physical activity may have promise as a risk reduction intervention and that prospective data are more likely to yield significant results than the cross-sectional methodology employed in the current study. © Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

How do electronic cigarettes affect cravings to smoke or vape? Parsing the influences of nicotine and expectancies using the balanced-placebo design.

PubMed

Palmer, Amanda M; Brandon, Thomas H

2018-05-01

Although electronic cigarettes (e-cigarettes) are frequently initiated for smoking cessation, results from the first two clinical trials testing this suggest that the perceived benefits of vaping may be influenced by non-nicotine factors, including cognitive outcome expectancies. The current study investigated the separate and combined effects of nicotine delivery and outcome expectancies on cravings for cigarettes and e-cigarettes using a balanced-placebo experiment. Drug dosage (contains nicotine or not) was crossed with instructional set (told nicotine or non-nicotine) during ad lib e-cigarette use sessions by 128 current e-cigarette users (52 identifying as current cigarette smokers or "dual users"). It was hypothesized that reduction in craving for both cigarettes and e-cigarettes following e-cigarette administration would be driven primarily by the instructional set manipulation, reflecting the influence of outcome expectancies. As hypothesized, among dual users, a main effect of instructional set emerged on reductions in craving to smoke cigarettes, with participants who were told that their e-cigarette contained nicotine reporting greater craving reduction (p = .046). With respect to reduced cravings for e-cigarettes, we found an interaction between drug dose and instructional set (p = .02) such that nicotine e-cigarettes reduced cravings more than non-nicotine e-cigarettes only among participants told to expect nicotine. Findings suggest that cognitive expectancies contribute to the acute effects of e-cigarettes on craving, which may provide guidance for their potential as smoking cessation aids. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Modeling learning in brain stem and cerebellar sites responsible for VOR plasticity

NASA Technical Reports Server (NTRS)

Quinn, K. J.; Didier, A. J.; Baker, J. F.; Peterson, B. W.

1998-01-01

A simple model of vestibuloocular reflex (VOR) function was used to analyze several hypotheses currently held concerning the characteristics of VOR plasticity. The network included a direct vestibular pathway and an indirect path via the cerebellum. An optimization analysis of this model suggests that regulation of brain stem sites is critical for the proper modification of VOR gain. A more physiologically plausible learning rule was also applied to this network. Analysis of these simulation results suggests that the preferred error correction signal controlling gain modification of the VOR is the direct output of the accessory optic system (AOS) to the vestibular nuclei vs. a signal relayed through the cerebellum via floccular Purkinje cells. The potential anatomical and physiological basis for this conclusion is discussed, in relation to our current understanding of the latency of the adapted VOR response.

Rethinking the dispersal of Homo sapiens out of Africa.

PubMed

Groucutt, Huw S; Petraglia, Michael D; Bailey, Geoff; Scerri, Eleanor M L; Parton, Ash; Clark-Balzan, Laine; Jennings, Richard P; Lewis, Laura; Blinkhorn, James; Drake, Nick A; Breeze, Paul S; Inglis, Robyn H; Devès, Maud H; Meredith-Williams, Matthew; Boivin, Nicole; Thomas, Mark G; Scally, Aylwyn

2015-01-01

Current fossil, genetic, and archeological data indicate that Homo sapiens originated in Africa in the late Middle Pleistocene. By the end of the Late Pleistocene, our species was distributed across every continent except Antarctica, setting the foundations for the subsequent demographic and cultural changes of the Holocene. The intervening processes remain intensely debated and a key theme in hominin evolutionary studies. We review archeological, fossil, environmental, and genetic data to evaluate the current state of knowledge on the dispersal of Homo sapiens out of Africa. The emerging picture of the dispersal process suggests dynamic behavioral variability, complex interactions between populations, and an intricate genetic and cultural legacy. This evolutionary and historical complexity challenges simple narratives and suggests that hybrid models and the testing of explicit hypotheses are required to understand the expansion of Homo sapiens into Eurasia. © 2015 Wiley Periodicals, Inc.

Seed dormancy and germination—emerging mechanisms and new hypotheses

PubMed Central

Nonogaki, Hiroyuki

2014-01-01

Seed dormancy has played a significant role in adaptation and evolution of seed plants. While its biological significance is clear, molecular mechanisms underlying seed dormancy induction, maintenance and alleviation still remain elusive. Intensive efforts have been made to investigate gibberellin and abscisic acid metabolism in seeds, which greatly contributed to the current understanding of seed dormancy mechanisms. Other mechanisms, which might be independent of hormones, or specific to the seed dormancy pathway, are also emerging from genetic analysis of “seed dormancy mutants.” These studies suggest that chromatin remodeling through histone ubiquitination, methylation and acetylation, which could lead to transcription elongation or gene silencing, may play a significant role in seed dormancy regulation. Small interfering RNA and/or long non-coding RNA might be a trigger of epigenetic changes at the seed dormancy or germination loci, such as DELAY OF GERMINATION1. While new mechanisms are emerging from genetic studies of seed dormancy, novel hypotheses are also generated from seed germination studies with high throughput gene expression analysis. Recent studies on tissue-specific gene expression in tomato and Arabidopsis seeds, which suggested possible “mechanosensing” in the regulatory mechanisms, advanced our understanding of embryo-endosperm interaction and have potential to re-draw the traditional hypotheses or integrate them into a comprehensive scheme. The progress in basic seed science will enable knowledge translation, another frontier of research to be expanded for food and fuel production. PMID:24904627

Tidal Modulation of Ice-shelf Flow: a Viscous Model of the Ross Ice Shelf

NASA Technical Reports Server (NTRS)

Brunt, Kelly M.; MacAyeal, Douglas R.

2014-01-01

Three stations near the calving front of the Ross Ice Shelf, Antarctica, recorded GPS data through a full spring-neap tidal cycle in November 2005. The data revealed a diurnal horizontal motion that varied both along and transverse to the long-term average velocity direction, similar to tidal signals observed in other ice shelves and ice streams. Based on its periodicity, it was hypothesized that the signal represents a flow response of the Ross Ice Shelf to the diurnal tides of the Ross Sea. To assess the influence of the tide on the ice-shelf motion, two hypotheses were developed. The first addressed the direct response of the ice shelf to tidal forcing, such as forces due to sea-surface slopes or forces due to sub-ice-shelf currents. The second involved the indirect response of ice-shelf flow to the tidal signals observed in the ice streams that source the ice shelf. A finite-element model, based on viscous creep flow, was developed to test these hypotheses, but succeeded only in falsifying both hypotheses, i.e. showing that direct tidal effects produce too small a response, and indirect tidal effects produce a response that is not smooth in time. This nullification suggests that a combination of viscous and elastic deformation is required to explain the observations.

The drive for muscularity in men: media influences and objectification theory.

PubMed

Daniel, Samantha; Bridges, Sara K

2010-01-01

Presently, objectification theory has yielded mixed results when utilized to explain body image concerns in men. An online survey assessing internalization of media ideals, self-objectification, body surveillance, body shame, the drive for muscularity, and body mass index (BMI) was completed by 244 predominantly college-aged males. Path analyses were used to investigate relationships among these variables where it was hypothesized that objectification variables would mediate the relationship between internalization of media ideals and the drive for muscularity. Internalization of media ideals was the strongest predictor of the drive for muscularity, followed by BMI, though variables of objectification theory had no impact on the drive for muscularity contrary to hypotheses. The results suggest that objectification theory may not be applicable to men as it is currently measured. Copyright 2009 Elsevier Ltd. All rights reserved.

An Investigation of the Hypotheses for Formation of the Platy-Ridged Terrain in Elysium Planitia, Mars

NASA Astrophysics Data System (ADS)

Yue, Z.; Gou, S.; Michael, G.; Di, K.; Xie, H.; Gong, H.; Shao, Y.

2017-07-01

The origin of the platy-ridged-polygonized (PRP) terrains on Martian surface has long been debated. The terrain has generally been classified as water, pack ice, or basalt lava related flow. The crater counting results of the PRP terrains suggest they are geologically very young; therefore, they are significant in understanding the recent evolution of Mars. This work evaluated the current hypotheses through detailed analysis of the distribution and microtopographies with the High Resolution Imaging Science Experiment (HiRISE) images for the PRP terrains in Elysium Planitia, Mars. Quantitative measurements and statistics of the typical features of the PRP terrains were also made. In addition, we also found an analog site in Tarim Basin in Xinjiang, China. Our results suggest that mud flow is responsible for the formation of the PRP terrains on the Mars surface, although the hypothesis of low-viscosity basalt lava floods cannot be completely excluded. This finding implies that a regional environment suitable for liquid water may have existed in recent geologic time, which has great importance for future Mars scientific exploration.

GABA Neuron Alterations, Cortical Circuit Dysfunction and Cognitive Deficits in Schizophrenia

PubMed Central

Gonzalez-Burgos, Guillermo; Fish, Kenneth N.; Lewis, David A.

2011-01-01

Schizophrenia is a brain disorder associated with cognitive deficits that severely affect the patients' capacity for daily functioning. Whereas our understanding of its pathophysiology is limited, postmortem studies suggest that schizophrenia is associated with deficits of GABA-mediated synaptic transmission. A major role of GABA-mediated transmission may be producing synchronized network oscillations which are currently hypothesized to be essential for normal cognitive function. Therefore, cognitive deficits in schizophrenia may result from a GABA synapse dysfunction that disturbs neural synchrony. Here, we highlight recent studies further suggesting alterations of GABA transmission and network oscillations in schizophrenia. We also review current models for the mechanisms of GABA-mediated synchronization of neural activity, focusing on parvalbumin-positive GABA neurons, which are altered in schizophrenia and whose function has been strongly linked to the production of neural synchrony. Alterations of GABA signaling that impair gamma oscillations and, as a result, cognitive function suggest paths for novel therapeutic interventions. PMID:21904685

Choice by value encoding and value construction: processes of loss aversion.

PubMed

Willemsen, Martijn C; Böckenholt, Ulf; Johnson, Eric J

2011-08-01

Loss aversion and reference dependence are 2 keystones of behavioral theories of choice, but little is known about their underlying cognitive processes. We suggest an additional account for loss aversion that supplements the current account of the value encoding of attributes as gains or losses relative to a reference point, introducing a value construction account. Value construction suggests that loss aversion results from biased evaluations during information search and comparison processes. We develop hypotheses that identify the influence of both accounts and examine process-tracing data for evidence. Our data suggest that loss aversion is the result of the initial direct encoding of losses that leads to the subsequent process of directional comparisons distorting attribute valuations and the final choice.

The preparatory set: a novel approach to understanding stress, trauma, and the bodymind therapies

PubMed Central

Payne, Peter; Crane-Godreau, Mardi A.

2015-01-01

Basic to all motile life is a differential approach/avoid response to perceived features of environment. The stages of response are initial reflexive noticing and orienting to the stimulus, preparation, and execution of response. Preparation involves a coordination of many aspects of the organism: muscle tone, posture, breathing, autonomic functions, motivational/emotional state, attentional orientation, and expectations. The organism organizes itself in relation to the challenge. We propose to call this the “preparatory set” (PS). We suggest that the concept of the PS can offer a more nuanced and flexible perspective on the stress response than do current theories. We also hypothesize that the mechanisms of body-mind therapeutic and educational systems (BTES) can be understood through the PS framework. We suggest that the BTES, including meditative movement, meditation, somatic education, and the body-oriented psychotherapies, are approaches that use interventions on the PS to remedy stress and trauma. We discuss how the PS can be adaptive or maladaptive, how BTES interventions may restore adaptive PS, and how these concepts offer a broader and more flexible view of the phenomena of stress and trauma. We offer supportive evidence for our hypotheses, and suggest directions for future research. We believe that the PS framework will point to ways of improving the management of stress and trauma, and that it will suggest directions of research into the mechanisms of action of BTES. PMID:25883565

A wet-geology and cold-climate Mars model: Punctuation of a slow dynamic approach to equilibrium

NASA Technical Reports Server (NTRS)

Kargel, J. S.

1993-01-01

It was suggested that Mars may have possessed a relatively warm humid climate and a vigorous hydrological cycle involving meteoric precipitation, oceans, and continental ice sheets. Baker hypothesized that these geologically active conditions may have been repeated several times; each of these dynamic epochs was followed by a collapse of the climate and hydrologic cycle of Mars into essentially current conditions, completing what is termed a 'Baker cycle'. The purpose is to present an endmember possibility that Martian glacial landscapes, including some that were previously considered to have formed under warm climatic conditions, might be explained by processes compatible with an extremely cold surface. Two aspects of hypothesized Martian glacial terrains were cited as favoring a warm climate during Baker cycles: (1) the formation of some landscapes, including possible eskers, tunnel channels, drumlins, and outwash plains, appears to have required liquid water, and (2) a liquid-surfaced ocean was probably necessary to feed the glaciers. The requirement for liquid water, if these features were correctly interpreted, is difficult to avoid; it is entirely possible that a comparatively warm climate was involved, but it is not clear that formation of landforms by wet-based glaciers actually requires a warm climate. Even less certain is the supposed requirement for liquid oceans. Formation of glaciers only requires a source of water or ice to supply an amount of precipitation that exceeds losses due to melting and sublimation. At Martian temperatures precipitation is very low, but so are melting and sublimation, so a large body of ice that is unstable with respect to sublimation may take the role of Earth's oceans in feeding the glaciers. Recent models suggest that even current Martian polar caps, long thought to be static bodies of ice and dust, might actually be slow-moving, cryogenic continental glaciers. Is it possible that subglacial processes beneath cryogenic (but wetbased) ice sheets formed the hypothesized Martian glacial landscapes?

By how much do we underestimate species diversity of liverworts using morphological evidence? An example from Australasian Plagiochila (Plagiochilaceae: Jungermanniopsida).

PubMed

Renner, Matt A M; Heslewood, Margaret M; Patzak, Simon D F; Schäfer-Verwimp, Alfons; Heinrichs, Jochen

2017-02-01

As a framework for revisionary study of the leafy liverwort Plagiochila in Australia, two methods for species delimitation on molecular sequence data, General Mixed Yule Coalescence model (GMYC) and Automatic Barcode Gap Discovery (ABGD) were applied to a dataset including 265 individuals from Australia, New Zealand, and the Pacific. Groups returned by GMYC and ABGD were incongruent in some lineages, and ABGD tended to lump groups. This may reflect underlying heterogeneity in the history of diversification within different lineages of Plagiochila. GMYC from trees calculated using three different molecular clocks were compared, in some lineages different primary species hypotheses were returned by analyses of trees estimated under different clock models, suggesting clock model selection should be a routine component of phylogeny reconstruction for tree-based species delimitation methods, such as GMYC. Our results suggest that a minimum of 71 Plagiochilaceae species occur in Australasia, 16 more than currently accepted for the region, comprising 8 undetermined species and 8 synonyms requiring reinstatement. Despite modern taxonomic investigation over a four decade period, (1) real diversity is 29% higher than currently recognized; and (2) 12 of 33, or 36%, of currently accepted and previously untested Australasian species have circumscription issues, including polyphyly, paraphyly, internal phylogenetic structure, or combinations of two or more of these issues. These both reflect the many challenges associated with grouping decisions based solely on morphological data in morphologically simple yet polymorphic plant lineages. Our results highlight again the critical need for combined molecular-morphological datasets as a basis for resolving robust species hypotheses in species-rich bryophyte lineages. Copyright © 2016 Elsevier Inc. All rights reserved.

Psychohistorical Hypotheses on Japan's History of Hostility Towards China.

PubMed

Wang, Bo; Rudmin, Floyd

2016-01-01

The accelerating tensions and military posturing between Japan and China have created a serious crisis with a danger of a catastrophic war. The purpose of this paper is to summarize the events of the current crisis, and to put it in the context of Japan's long history of hostility to China and repeated attempts at conquest. The historical record shows that Japan has attacked China at least seven times, even though China has never attacked Japan. The irrationality of Japan's behavior is demonstrated by the repetition of this hostile behavior despite the enormous human and economic costs that Japan has suffered because of it. The irrationality of Japan's militarism suggests that psychological explanations may be required to understand this phenomenon. Several hypotheses are proposed, including 1) projected paranoid aggression, 2) collective Zeigarnik compulsion, 3) perceived weakness exciting aggression, 4) national inferiority feelings, 5) cultural narcissism, and 6) Oedipal-like hatred of a parent culture.

The Second Brain: Is the Gut Microbiota a Link Between Obesity and Central Nervous System Disorders?

PubMed Central

Ochoa-Repáraz, Javier; Kasper, Lloyd H.

2016-01-01

The gut-brain axis is a bi-directional integrated system composed by immune, endocrine and neuronal components by which the gap between the gut microbiota and the brain is significantly impacted. An increasing number of different gut microbial species are now postulated to regulate brain function in health and disease. The westernized diet is hypothesized to be the cause of the current obesity levels in many countries, a major socio-economical health problem. Experimental and epidemiological evidence suggest that the gut microbiota is responsible for significant immunologic, neuronal and endocrine changes that lead to obesity. We hypothesize that the gut microbiota, and changes associated with diet, affect the gut-brain axis and may possibly contribute to the development of mental illness. In this review, we discuss the links between diet, gut dysbiosis, obesity, and immunologic and neurologic diseases that impact brain function and behavior. PMID:26865085

The Second Brain: Is the Gut Microbiota a Link Between Obesity and Central Nervous System Disorders?

PubMed

Ochoa-Repáraz, Javier; Kasper, Lloyd H

2016-03-01

The gut-brain axis is a bi-directional integrated system composed by immune, endocrine, and neuronal components by which the gap between the gut microbiota and the brain is significantly impacted. An increasing number of different gut microbial species are now postulated to regulate brain function in health and disease. The westernized diet is hypothesized to be the cause of the current obesity levels in many countries, a major socio-economical health problem. Experimental and epidemiological evidence suggest that the gut microbiota is responsible for significant immunologic, neuronal, and endocrine changes that lead to obesity. We hypothesize that the gut microbiota, and changes associated with diet, affect the gut-brain axis and may possibly contribute to the development of mental illness. In this review, we discuss the links between diet, gut dysbiosis, obesity, and immunologic and neurologic diseases that impact brain function and behavior.

Positive and Negative Associations between Adolescents’ Religiousness and Health Behaviors via Self-Regulation

PubMed Central

Holmes, Christopher J.; Kim-Spoon, Jungmeen

2015-01-01

It has been proposed that self-regulation may be the explanatory mechanism for the relation between religiousness and positive health behaviors. However, different religious motivations have differential effects on a variety of health related outcomes, which may explain the adverse effects of religiousness found in some studies. The current study hypothesized that higher identification as religious motivation would be linked to higher health-promoting behavior and lower health-risk behavior through higher self-regulation, whereas higher introjection would be linked to lower health-promoting behavior and higher health-risk behavior through lower self-regulation. The sample included 220 adolescents (mean age = 15 years, 55% male) and their primary caregivers. Structural equation modeling results supported the hypotheses and indicated that adolescent self-regulation mediated the relations between their religious motivation and health behavior. The findings suggest that different types of religious motivation may be promotive or hindering for adolescents’ health. PMID:27595048

Positive and Negative Associations between Adolescents' Religiousness and Health Behaviors via Self-Regulation.

PubMed

Holmes, Christopher J; Kim-Spoon, Jungmeen

It has been proposed that self-regulation may be the explanatory mechanism for the relation between religiousness and positive health behaviors. However, different religious motivations have differential effects on a variety of health related outcomes, which may explain the adverse effects of religiousness found in some studies. The current study hypothesized that higher identification as religious motivation would be linked to higher health-promoting behavior and lower health-risk behavior through higher self-regulation, whereas higher introjection would be linked to lower health-promoting behavior and higher health-risk behavior through lower self-regulation. The sample included 220 adolescents (mean age = 15 years, 55% male) and their primary caregivers. Structural equation modeling results supported the hypotheses and indicated that adolescent self-regulation mediated the relations between their religious motivation and health behavior. The findings suggest that different types of religious motivation may be promotive or hindering for adolescents' health.

A nearshore processes field experiment at Cape Hatteras, North Carolina, U.S.A.

USGS Publications Warehouse

List, Jeffrey H.; Warner, John C.; Thieler, E. Robert; Haas, Kevin; Voulgaris, George; McNinch, Jesse E.; Brodie, Katherine L.; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

2011-01-01

A month-long field experiment focused on the nearshore hydrodynamics of Diamond Shoals adjacent to Cape Hatteras Point, North Carolina, was conducted in February 2010. The objectives of this multi-institutional experiment were to test hypotheses related to Diamond Shoals as a sink in the regional sediment budget and to provide data for evaluating numerical models. The experiment included in-situ instrumentation for measuring waves and currents; a video camera system for measuring surface currents at a nearshore transect; a radar system for measuring regional surface currents over Diamond Shoals and the adjacent coast; a vehicle-based scanning lidar and radar system for mapping beach topography, nearshore wave breaking intensity, bathymetry (through wave celerity inversion), and wave direction; and an amphibious vehicle system for surveying single-beam bathymetry. Preliminary results from wave and current measurements suggest that shoal-building processes were active during the experiment.

Pelvic form and locomotor adaptation in strepsirrhine primates.

PubMed

Lewton, Kristi L

2015-01-01

The pelvic girdle is a complex structure with a critical role in locomotion, but efforts to model the mechanical effects of locomotion on its shape remain difficult. Traditional approaches to understanding form and function include univariate adaptive hypothesis-testing derived from mechanical models. Geometric morphometric (GM) methods can yield novel insight into overall three-dimensional shape similarities and differences across groups, although the utility of GM in assessing functional differences has been questioned. This study evaluates the contributions of both univariate and GM approaches to unraveling the trait-function associations between pelvic form and locomotion. Three-dimensional landmarks were collected on a phylogenetically-broad sample of 180 pelves from nine primate taxa. Euclidean interlandmark distances were calculated to facilitate testing of biomechanical hypotheses, and a principal components (PC) analysis was performed on Procrustes coordinates to examine overall shape differences. Both linear dimensions and PC scores were subjected to phylogenetic ANOVA. Many of the null hypotheses relating linear dimensions to locomotor loading were not rejected. Although both analytical approaches suggest that ilium width and robusticity differ among locomotor groups, the GM analysis also suggests that ischiopubic shape differentiates groups. Although GM provides additional quantitative results beyond the univariate analyses, this study highlights the need for new GM methods to more specifically address functional shape differences among species. Until these methods are developed, it would be prudent to accompany tests of directional biomechanical hypotheses with current GM methods for a more nuanced understanding of shape and function. © 2014 Wiley Periodicals, Inc.

Modeling the Association between Lifecourse Socioeconomic Disadvantage and Systemic Inflammation in Healthy Adults: The Role of Self-Control

PubMed Central

Hostinar, Camelia E.; Ross, Kharah M.; Chen, Edith; Miller, Gregory E.

2015-01-01

Objective We sought to identify pathways connecting lifecourse socioeconomic status (SES) with chronic, low-grade inflammation, focusing on the explanatory roles of self-control, abdominal adiposity, and health practices. Methods Participants were 360 adults aged 15 - 55 who were free of chronic medical conditions. They were roughly equally divided between low and high current SES, with each group further divided between low and high early-life SES. Structural Equation Modeling (SEM) was used to identify direct and indirect pathways linking early-life and current SES with low-grade, chronic inflammation in adulthood, as manifest by serum interleukin-6 and C-reactive protein. Low SES was hypothesized to relate to inflammation by reducing self-control, which in turn was hypothesized to facilitate lifestyle factors that potentiate inflammation (smoking, alcohol use, sedentary behavior, and weight gain). Results Analyses revealed that self-control was pivotal in linking both early-life and current SES to inflammation. Low early-life SES was related to a harsher family climate, and in turn lower adult self-control, over and above the effects of current SES. Controlling for early-life SES, low current SES was associated with perceived stress, and in turn diminished self-control. Results showed that lower self-control primarily operated through higher abdominal adiposity to associate with greater inflammation. Conclusions The findings suggest a mechanistic scenario wherein low SES in early-life or adulthood depletes self-control and in turn fosters adiposity and inflammation. These pathways should be studied longitudinally to elucidate and potentially ameliorate socioeconomic disparities in health. PMID:25110854

Structure theorems and the dynamics of nitrogen catabolite repression in yeast

PubMed Central

Boczko, Erik M.; Cooper, Terrance G.; Gedeon, Tomas; Mischaikow, Konstantin; Murdock, Deborah G.; Pratap, Siddharth; Wells, K. Sam

2005-01-01

By using current biological understanding, a conceptually simple, but mathematically complex, model is proposed for the dynamics of the gene circuit responsible for regulating nitrogen catabolite repression (NCR) in yeast. A variety of mathematical “structure” theorems are described that allow one to determine the asymptotic dynamics of complicated systems under very weak hypotheses. It is shown that these theorems apply to several subcircuits of the full NCR circuit, most importantly to the URE2–GLN3 subcircuit that is independent of the other constituents but governs the switching behavior of the full NCR circuit under changes in nitrogen source. Under hypotheses that are fully consistent with biological data, it is proven that the dynamics of this subcircuit is simple periodic behavior in synchrony with the cell cycle. Although the current mathematical structure theorems do not apply to the full NCR circuit, extensive simulations suggest that the dynamics is constrained in much the same way as that of the URE2–GLN3 subcircuit. This finding leads to the proposal that mathematicians study genetic circuits to find new geometries for which structure theorems may exist. PMID:15814615

Plant cutin genesis: unanswered questions.

PubMed

Domínguez, Eva; Heredia-Guerrero, José A; Heredia, Antonio

2015-09-01

The genesis of cutin, the main lipid polymer present in the biosphere, has remained elusive for many years. Recently, two main approaches have attempted to explain the process of cutin polymerization. One describes the existence of an acyltransferase cutin synthase enzyme that links activated monomers of cutin in the outer cell wall, while the other shows that plant cutin is the final result of an extracellular nonenzymatic self-assembly and polymerizing process of cutin monomers. In this opinion article, we explain both models and suggest that they could be pieces of a more complex biological scenario. We also highlight their different characteristics and current limitations, and suggest a potential synergism of both hypotheses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Activation state of the hyperpolarization-activated current modulates temperature-sensitivity of firing in locus coeruleus neurons from bullfrogs.

PubMed

Santin, Joseph M; Hartzler, Lynn K

2015-06-15

Locus coeruleus neurons of anuran amphibians contribute to breathing control and have spontaneous firing frequencies that, paradoxically, increase with cooling. We previously showed that cooling inhibits a depolarizing membrane current, the hyperpolarization-activated current (I h) in locus coeruleus neurons from bullfrogs, Lithobates catesbeianus (Santin JM, Watters KC, Putnam RW, Hartzler LK. Am J Physiol Regul Integr Comp Physiol 305: R1451-R1464, 2013). This suggests an unlikely role for I h in generating cold activation, but led us to hypothesize that inhibition of I h by cooling functions as a physiological brake to limit the cold-activated response. Using whole cell electrophysiology in brain slices, we employed 2 mM Cs(+) (an I h antagonist) to isolate the role of I h in spontaneous firing and cold activation in neurons recorded with either control or I h agonist (cyclic AMP)-containing artificial intracellular fluid. I h did not contribute to the membrane potential (V m) and spontaneous firing at 20°C. Although voltage-clamp analysis confirmed that cooling inhibits I h, its lack of involvement in setting baseline firing and V m precluded its ability to regulate cold activation as hypothesized. In contrast, neurons dialyzed with cAMP exhibited greater baseline firing frequencies at 20°C due to I h activation. Our hypothesis was supported when the starting level of I h was enhanced by elevating cAMP because cold activation was converted to more ordinary cold inhibition. These findings indicate that situations leading to enhancement of I h facilitate firing at 20°C, yet the hyperpolarization associated with inhibiting a depolarizing cation current by cooling blunts the net V m response to cooling to oppose normal cold-depolarizing factors. This suggests that the influence of I h activation state on neuronal firing varies in the poikilothermic neuronal environment. Copyright © 2015 the American Physiological Society.

Stone tools, language and the brain in human evolution.

PubMed

Stout, Dietrich; Chaminade, Thierry

2012-01-12

Long-standing speculations and more recent hypotheses propose a variety of possible evolutionary connections between language, gesture and tool use. These arguments have received important new support from neuroscientific research on praxis, observational action understanding and vocal language demonstrating substantial functional/anatomical overlap between these behaviours. However, valid reasons for scepticism remain as well as substantial differences in detail between alternative evolutionary hypotheses. Here, we review the current status of alternative 'gestural' and 'technological' hypotheses of language origins, drawing on current evidence of the neural bases of speech and tool use generally, and on recent studies of the neural correlates of Palaeolithic technology specifically.

Stone tools, language and the brain in human evolution

PubMed Central

Stout, Dietrich; Chaminade, Thierry

2012-01-01

Long-standing speculations and more recent hypotheses propose a variety of possible evolutionary connections between language, gesture and tool use. These arguments have received important new support from neuroscientific research on praxis, observational action understanding and vocal language demonstrating substantial functional/anatomical overlap between these behaviours. However, valid reasons for scepticism remain as well as substantial differences in detail between alternative evolutionary hypotheses. Here, we review the current status of alternative ‘gestural’ and ‘technological’ hypotheses of language origins, drawing on current evidence of the neural bases of speech and tool use generally, and on recent studies of the neural correlates of Palaeolithic technology specifically. PMID:22106428

The effect of challenge and hindrance stressors on safety behavior and safety outcomes: a meta-analysis.

PubMed

Clarke, Sharon

2012-10-01

The significance of occupational stressors as a risk factor in accidents has long been recognized; however, the behavioral mechanisms underlying this relationship are currently not well-understood. Meta-analysis was utilized to test the relationships between occupational stressors (challenge and hindrance), safety behaviors (compliance and participation), and safety outcomes (occupational injuries and near-misses). It was hypothesized that hindrance stressors would have negative effects on both safety compliance and safety participation, and subsequently, safety outcomes, whereas challenge stressors would have positive effects. The hypotheses relating to hindrance stressors were supported, suggesting that hindrance stressors lead to a significant reduction in both compliance with safety rules and participation in safety-related activities. Hindrance stressors were also associated with higher levels of occupational injuries and near-misses. The relationship between hindrance stressors and occupational injuries was fully mediated by safety behaviors. However, the hypotheses related to challenge stressors were not supported. Challenge stressors had a nonsignificant, near-zero association with compliance and occupational injuries, a small negative association with participation, and a small positive association with near-misses. The theoretical and practical implications of the meta-analytic findings are discussed, as well as avenues for further research.

Human female orgasm as evolved signal: a test of two hypotheses.

PubMed

Ellsworth, Ryan M; Bailey, Drew H

2013-11-01

We present the results of a study designed to empirically test predictions derived from two hypotheses regarding human female orgasm behavior as an evolved communicative trait or signal. One hypothesis tested was the female fidelity hypothesis, which posits that human female orgasm signals a woman's sexual satisfaction and therefore her likelihood of future fidelity to a partner. The other was sire choice hypothesis, which posits that women's orgasm behavior signals increased chances of fertilization. To test the two hypotheses of human female orgasm, we administered a questionnaire to 138 females and 121 males who reported that they were currently in a romantic relationship. Key predictions of the female fidelity hypothesis were not supported. In particular, orgasm was not associated with female sexual fidelity nor was orgasm associated with male perceptions of partner sexual fidelity. However, faked orgasm was associated with female sexual infidelity and lower male relationship satisfaction. Overall, results were in greater support of the sire choice signaling hypothesis than the female fidelity hypothesis. Results also suggest that male satisfaction with, investment in, and sexual fidelity to a mate are benefits that favored the selection of orgasmic signaling in ancestral females.

Impact of Sexual Coercion on Romantic Experiences of Adolescents and Young Adults

PubMed Central

Furman, Wyndol

2014-01-01

Little is known about the effect of sexual coercion on romantic relationship quality and dating experiences. The current study aimed to address this dearth in the literature and test the hypothesis that sexual coercion has a negative impact on victims’ subsequent romantic experiences. Using a sample of 94 youth (44 males and 50 females), the current study addressed the impact of sexual coercion on romantic relationship quality and dating experiences. Tracking youth for 8.5 years (M age at Wave 1 = 15.10 years, SD = .49), the current study used piecewise growth curve modeling to account for shifts in the intercept and slope of romantic experiences following sexual coercion. Negative interactions immediately increased following coercion and continued to have an accelerated rate of growth (i.e., a slope change). Jealousy in romantic relationships increased in slope. Serious dating decelerated following the coercive incident. Results were largely consistent across gender and severity of the coercive incident. Contrary to hypotheses, relational support, relationship satisfaction, and casual dating did not significantly change following sexual coercion. Consistent with hypotheses, sexual coercion had a negative impact on romantic experiences. These findings have clinical implications for both prevention and intervention around sexual violence. In addition, the consistency of findings across gender and severity suggests that increased focus should be directed toward both male sexual coercion and less severe sexual coercion. PMID:24519107

Algicidal bacteria in the sea and their impact on algal blooms.

PubMed

Mayali, Xavier; Azam, Farooq

2004-01-01

Over the past two decades, many reports have revealed the existence of bacteria capable of killing phytoplankton. These algicidal bacteria sometimes increase in abundance concurrently with the decline of algal blooms, suggesting that they may affect algal bloom dynamics. Here, we synthesize the existing knowledge on algicidal bacteria interactions with marine eukaryotic microalgae. We discuss the effectiveness of the current methods to characterize the algicidal phenotype in an ecosystem context. We briefly consider the literature on the phylogenetic identification of algicidal bacteria, their interaction with their algal prey, the characterization of algicidal molecules, and the enumeration of algicidal bacteria during algal blooms. We conclude that, due to limitations of current methods, the evidence for algicidal bacteria causing algal bloom decline is circumstantial. New methods and an ecosystem approach are needed to test hypotheses on the impact of algicidal bacteria in algal bloom dynamics. This will require enlarging the scope of inquiry from its current focus on the potential utility of algicidal bacteria in the control of harmful algal blooms. We suggest conceptualizing bacterial algicidy within the general problem of bacterial regulation of algal community structure in the ocean.

Fatty acids in energy metabolism of the central nervous system.

PubMed

Panov, Alexander; Orynbayeva, Zulfiya; Vavilin, Valentin; Lyakhovich, Vyacheslav

2014-01-01

In this review, we analyze the current hypotheses regarding energy metabolism in the neurons and astroglia. Recently, it was shown that up to 20% of the total brain's energy is provided by mitochondrial oxidation of fatty acids. However, the existing hypotheses consider glucose, or its derivative lactate, as the only main energy substrate for the brain. Astroglia metabolically supports the neurons by providing lactate as a substrate for neuronal mitochondria. In addition, a significant amount of neuromediators, glutamate and GABA, is transported into neurons and also serves as substrates for mitochondria. Thus, neuronal mitochondria may simultaneously oxidize several substrates. Astrocytes have to replenish the pool of neuromediators by synthesis de novo, which requires large amounts of energy. In this review, we made an attempt to reconcile β-oxidation of fatty acids by astrocytic mitochondria with the existing hypothesis on regulation of aerobic glycolysis. We suggest that, under condition of neuronal excitation, both metabolic pathways may exist simultaneously. We provide experimental evidence that isolated neuronal mitochondria may oxidize palmitoyl carnitine in the presence of other mitochondrial substrates. We also suggest that variations in the brain mitochondrial metabolic phenotype may be associated with different mtDNA haplogroups.

Shift work and chronic disease: the epidemiological evidence

PubMed Central

Armstrong, M. E. G.; Cairns, B. J.; Key, T. J.; Travis, R. C.

2011-01-01

Background Shift work, including night work, has been hypothesized to increase the risk of chronic diseases, including cancer, cardiovascular disease (CVD), metabolic syndrome and diabetes. Recent reviews of evidence relating to these hypotheses have focussed on specific diseases or potential mechanisms, but no general summary of the current data on shift work and chronic disease has been published. Methods Systematic and critical reviews and recent original studies indexed in PubMed prior to 31 December 2009 were retrieved, aided by manual searches of reference lists. The main conclusions from reviews and principle results from recent studies are presented in text and tables. Results Published evidence is suggestive but not conclusive for an adverse association between night work and breast cancer but limited and inconsistent for cancers at other sites and all cancers combined. Findings on shift work, in relation to risks of CVD, metabolic syndrome and diabetes are also suggestive but not conclusive for an adverse relationship. Conclusions Heterogeneity of study exposures and outcomes and emphasis on positive but non-significant results make it difficult to draw general conclusions. Further data are needed for additional disease endpoints and study populations. PMID:21355031

Fatty Acids in Energy Metabolism of the Central Nervous System

PubMed Central

Orynbayeva, Zulfiya; Vavilin, Valentin; Lyakhovich, Vyacheslav

2014-01-01

In this review, we analyze the current hypotheses regarding energy metabolism in the neurons and astroglia. Recently, it was shown that up to 20% of the total brain's energy is provided by mitochondrial oxidation of fatty acids. However, the existing hypotheses consider glucose, or its derivative lactate, as the only main energy substrate for the brain. Astroglia metabolically supports the neurons by providing lactate as a substrate for neuronal mitochondria. In addition, a significant amount of neuromediators, glutamate and GABA, is transported into neurons and also serves as substrates for mitochondria. Thus, neuronal mitochondria may simultaneously oxidize several substrates. Astrocytes have to replenish the pool of neuromediators by synthesis de novo, which requires large amounts of energy. In this review, we made an attempt to reconcile β-oxidation of fatty acids by astrocytic mitochondria with the existing hypothesis on regulation of aerobic glycolysis. We suggest that, under condition of neuronal excitation, both metabolic pathways may exist simultaneously. We provide experimental evidence that isolated neuronal mitochondria may oxidize palmitoyl carnitine in the presence of other mitochondrial substrates. We also suggest that variations in the brain mitochondrial metabolic phenotype may be associated with different mtDNA haplogroups. PMID:24883315

Opening the crypt: current facts and hypotheses on the function of cryptopatches.

PubMed

Eberl, Gérard; Sawa, Shinichiro

2010-02-01

Cryptopatches, small aggregates of lymphoid cells found in the intestinal lamina propria, have been assigned many functions specific to gut immunity. Populated with seemingly immature lymphoid cells and dendritic cells, it has been suggested that cryptopatches maturate intraepithelial lymphocytes, Th17 cells, IL-22-producing NKp46(+) cells, and lymphoid tissues in response to the gut microbiota. Some of these issues, however, remain hotly debated. Therefore, cryptopatches are coming to the forefront of gut immunology and warrant a comprehensive discussion of their role in the development of the immune system.

Can Soft Drink Taxes Reduce Population Weight?

PubMed

Fletcher, Jason M; Frisvold, David; Tefft, Nathan

2010-01-01

Soft drink consumption has been hypothesized as one of the major factors in the growing rates of obesity in the US. Nearly two-thirds of all states currently tax soft drinks using excise taxes, sales taxes, or special exemptions to food exemptions from sales taxes to reduce consumption of this product, raise revenue, and improve public health. In this paper, we evaluate the impact of changes in state soft drink taxes on body mass index (BMI), obesity, and overweight. Our results suggest that soft drink taxes influence BMI, but that the impact is small in magnitude.

Stem and progenitor cells: the premature desertion of rigorous definitions.

PubMed

Seaberg, Raewyn M; van der Kooy, Derek

2003-03-01

A current disturbing trend in stem cell biology is the abandonment of rigorous definitions of stem and progenitor cells in favor of more ambiguous, all-encompassing concepts. However, recent studies suggest that there are consistent, functional differences in the biology of these two cell types. Admittedly, it can be difficult to harmonize the in vivo and in vitro functional differences between stem and progenitor cells. Nonetheless, these distinctions between cell types should be emphasized rather than ignored, as they can be used to test specific hypotheses in neural stem cell biology.

The Relationship of Interpersonal Distances to Television Shot Selection.

ERIC Educational Resources Information Center

Meyrowitz, Joshua

Based on research suggesting spatial zones of proximity in human behavior (individuals have definable zones of intimate, personal, social, and public space), it was hypothesized that "framed shots" of people on television screens would suggest specific distances to the viewer. The hypotheses were that subjects would estimate a greater…

HyQue: evaluating hypotheses using Semantic Web technologies.

PubMed

Callahan, Alison; Dumontier, Michel; Shah, Nigam H

2011-05-17

Key to the success of e-Science is the ability to computationally evaluate expert-composed hypotheses for validity against experimental data. Researchers face the challenge of collecting, evaluating and integrating large amounts of diverse information to compose and evaluate a hypothesis. Confronted with rapidly accumulating data, researchers currently do not have the software tools to undertake the required information integration tasks. We present HyQue, a Semantic Web tool for querying scientific knowledge bases with the purpose of evaluating user submitted hypotheses. HyQue features a knowledge model to accommodate diverse hypotheses structured as events and represented using Semantic Web languages (RDF/OWL). Hypothesis validity is evaluated against experimental and literature-sourced evidence through a combination of SPARQL queries and evaluation rules. Inference over OWL ontologies (for type specifications, subclass assertions and parthood relations) and retrieval of facts stored as Bio2RDF linked data provide support for a given hypothesis. We evaluate hypotheses of varying levels of detail about the genetic network controlling galactose metabolism in Saccharomyces cerevisiae to demonstrate the feasibility of deploying such semantic computing tools over a growing body of structured knowledge in Bio2RDF. HyQue is a query-based hypothesis evaluation system that can currently evaluate hypotheses about the galactose metabolism in S. cerevisiae. Hypotheses as well as the supporting or refuting data are represented in RDF and directly linked to one another allowing scientists to browse from data to hypothesis and vice versa. HyQue hypotheses and data are available at http://semanticscience.org/projects/hyque.

The structure of the UPPS-R-Child impulsivity scale and its relations with substance use outcomes among treatment-seeking adolescents.

PubMed

Tomko, Rachel L; Prisciandaro, James J; Falls, Sandhya Kutty; Magid, Viktoriya

2016-04-01

A youth version of the UPPS Impulsivity Scale (UPPS-R-C) was previously shown to predict drinking initiation among pre-adolescents. The goals of the current study were to confirm the structure of the UPPS-R-C using a sample of treatment-seeking adolescents and to examine the scales' relations with alcohol use, marijuana use, and problems related to substance use. Participants (N=120; ages 12-18; M=15.7) completed questionnaires at treatment intake. Confirmatory factor analysis (CFA) of the UPPS-R-C was conducted using a 5-factor model with factors corresponding to negative urgency, positive urgency, lack of perseverance, lack of premeditation, and sensation seeking. Relations between UPPS-R-C factors and binge drinking, marijuana use, and problems resulting from substance use were examined using path analysis. CFA suggested the 5-factor model provided adequate fit to the data. The hypothesized path model was partially supported, positive urgency was associated with frequency of binge drinking, and both negative urgency and frequency of binge drinking was associated with problems due to substance use. Other hypothesized paths were not significant. Although not hypothesized, negative urgency was associated with frequency of marijuana use and lack of perseverance was associated with problems due to use. Results suggest that the UPPS-R-C can be used with a treatment-seeking sample of adolescents. Furthermore, negative urgency, positive urgency, and lack of perseverance may be indicative of more severe substance use problems in a treatment setting. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The Structure of the UPPS-R-Child Impulsivity Scale and its Relations with Substance Use Outcomes Among Treatment-Seeking Adolescents

PubMed Central

Prisciandaro, James J.; Kutty Falls, Sandhya; Magid, Viktoriya

2016-01-01

Background A youth version of the UPPS Impulsivity Scale (UPPS-R-C) was previously shown to predict drinking initiation among pre-adolescents. The goals of the current study were to confirm the structure of the UPPS-R-C using a sample of treatment-seeking adolescents and to examine the scales’ relations with alcohol use, marijuana use, and problems related to substance use. Method Participants (N = 120; ages 12–18; M = 15.7) completed questionnaires at treatment intake. Confirmatory factor analysis (CFA) of the UPPS-R-C was conducted using a 5-factor model with factors corresponding to negative urgency, positive urgency, lack of perseverance, lack of premeditation, and sensation seeking. Relations between UPPS-R-C factors and binge drinking, marijuana use, and problems resulting from substance use were examined using path analysis. Results CFA suggested the 5-factor model provided adequate fit to the data. The hypothesized path model was partially supported, positive urgency was associated with frequency of binge drinking, and both negative urgency and frequency of binge drinking was associated with problems due to substance use. Other hypothesized paths were not significant. Although not hypothesized, negative urgency was associated with frequency of marijuana use and lack of perseverance was associated with problems due to use. Conclusions Results suggest that the UPPS-R-C can be used with a treatment-seeking sample of adolescents. Furthermore, negative urgency, positive urgency, and lack of perseverance may be indicative of more severe substance use problems in a treatment setting. PMID:26905208

Simulated visual field loss does not alter turning coordination in healthy young adults.

PubMed

Murray, Nicholas G; Ponce de Leon, Marlina; Ambati, V N Pradeep; Saucedo, Fabricio; Kennedy, Evan; Reed-Jones, Rebecca J

2014-01-01

Turning, while walking, is an important component of adaptive locomotion. Current hypotheses regarding the motor control of body segment coordination during turning suggest heavy influence of visual information. The authors aimed to examine whether visual field impairment (central loss or peripheral loss) affects body segment coordination during walking turns in healthy young adults. No significant differences in the onset time of segments or intersegment coordination were observed because of visual field occlusion. These results suggest that healthy young adults can use visual information obtained from central and peripheral visual fields interchangeably, pointing to flexibility of visuomotor control in healthy young adults. Further study in populations with chronic visual impairment and those with turning difficulties are warranted.

Climate as a driver of tropical insular diversity: comparative phylogeography of two ecologically distinctive frogs in Puerto Rico

PubMed Central

Barker, Brittany S.; Rodríguez-Robles, Javier A.; Cook, Joseph A.

2014-01-01

The effects of late Quaternary climate on distributions and evolutionary dynamics of insular species are poorly understood in most tropical archipelagoes. We used ecological niche models under past and current climate to derive hypotheses regarding how stable climatic conditions shaped genetic diversity in two ecologically distinctive frogs in Puerto Rico. Whereas the Mountain Coquí, Eleutherodactylus portoricensis, is restricted to montane forest in the Cayey and Luquillo Mountains, the Red-eyed Coquí, E. antillensis, is a habitat generalist distributed across the entire Puerto Rican Bank (Puerto Rico and the Virgin Islands, excluding St. Croix). To test our hypotheses, we conducted phylogeographic and population genetic analyses based on mitochondrial and nuclear loci of each species across their range in Puerto Rico. Patterns of population differentiation in E. portoricensis, but not in E. antillensis, supported our hypotheses. For E. portoricensis, these patterns include: individuals isolated by long-term unsuitable climate in the Río Grande de Loíza Basin in eastern Puerto Rico belong to different genetic clusters; past and current climate strongly predicted genetic differentiation; and Cayey and Luquillo Mountains populations split prior to the last interglacial. For E. antillensis, these patterns include: genetic clusters did not fully correspond to predicted long-term unsuitable climate; and past and current climate weakly predicted patterns of genetic differentiation. Genetic signatures in E. antillensis are consistent with a recent range expansion into western Puerto Rico, possibly resulting from climate change and anthropogenic influences. As predicted, regions with a large area of long-term suitable climate were associated with higher genetic diversity in both species, suggesting larger and more stable populations. Finally, we discussed the implications of our findings for developing evidence-based management decisions for E. portoricensis, a taxon of special concern. Our findings illustrate the role of persistent suitable climatic conditions in promoting the persistence and diversification of tropical island organisms. PMID:26508809

Climate as a driver of tropical insular diversity: comparative phylogeography of two ecologically distinctive frogs in Puerto Rico.

PubMed

Barker, Brittany S; Rodríguez-Robles, Javier A; Cook, Joseph A

2015-08-01

The effects of late Quaternary climate on distributions and evolutionary dynamics of insular species are poorly understood in most tropical archipelagoes. We used ecological niche models under past and current climate to derive hypotheses regarding how stable climatic conditions shaped genetic diversity in two ecologically distinctive frogs in Puerto Rico. Whereas the Mountain Coquí, Eleutherodactylus portoricensis , is restricted to montane forest in the Cayey and Luquillo Mountains, the Red-eyed Coquí, E. antillensis , is a habitat generalist distributed across the entire Puerto Rican Bank (Puerto Rico and the Virgin Islands, excluding St. Croix). To test our hypotheses, we conducted phylogeographic and population genetic analyses based on mitochondrial and nuclear loci of each species across their range in Puerto Rico. Patterns of population differentiation in E. portoricensis , but not in E. antillensis , supported our hypotheses. For E. portoricensis , these patterns include: individuals isolated by long-term unsuitable climate in the Río Grande de Loíza Basin in eastern Puerto Rico belong to different genetic clusters; past and current climate strongly predicted genetic differentiation; and Cayey and Luquillo Mountains populations split prior to the last interglacial. For E. antillensis , these patterns include: genetic clusters did not fully correspond to predicted long-term unsuitable climate; and past and current climate weakly predicted patterns of genetic differentiation. Genetic signatures in E. antillensis are consistent with a recent range expansion into western Puerto Rico, possibly resulting from climate change and anthropogenic influences. As predicted, regions with a large area of long-term suitable climate were associated with higher genetic diversity in both species, suggesting larger and more stable populations. Finally, we discussed the implications of our findings for developing evidence-based management decisions for E. portoricensis , a taxon of special concern. Our findings illustrate the role of persistent suitable climatic conditions in promoting the persistence and diversification of tropical island organisms.

Interparental conflict and adolescent dating relationships: the role of perceived threat and self-blame appraisals.

PubMed

Kim, Kerri L; Jackson, Yo; Hunter, Heather L; Conrad, Selby M

2009-05-01

In line with the cognitive-contextual framework proposed by Grych and Fincham (1990), evidence suggests that children exposed to interparental conflict (IPC) are at risk for experiencing conflict within their own intimate relationships. The mediating role of adolescent appraisal in the relation between IPC and adolescent dating behavior was examined in the current study. Specifically, it was hypothesized that self-blame and threat appraisals would mediate the relation between IPC and adolescent maladaptive dating behaviors. To examine the potential mediating role of appraisal, 169 high school students completed the Children's Perception of Interparental Conflict (Grych, Seid, & Fincham, 1992) and Child and Adolescent Dating Relationships Inventory (Wolfe, Scott, Reitzel-Jaffe, Wekerle, Grasley, & Straatman, 2004). Findings suggest that self-blame appraisal partially mediated the relation between IPC and adolescent sexual aggression, and between IPC and adolescent threatening behavior. In addition, perceived threat appraisal partially mediated the relation between IPC and adolescent sexual aggression. Implications for the current findings are discussed.

The Extended Contact Hypothesis: A Meta-Analysis on 20 Years of Research.

PubMed

Zhou, Shelly; Page-Gould, Elizabeth; Aron, Arthur; Moyer, Anne; Hewstone, Miles

2018-04-01

According to the extended contact hypothesis, knowing that in-group members have cross-group friends improves attitudes toward this out-group. This meta-analysis covers the 20 years of research that currently exists on the extended contact hypothesis, and consists of 248 effect sizes from 115 studies. The aggregate relationship between extended contact and intergroup attitudes was r = .25, 95% confidence interval (CI) = [.22, .27], which reduced to r = .17, 95% CI = [.14, .19] after removing direct friendship's contribution; these results suggest that extended contact's hypothesized relationship to intergroup attitudes is small-to-medium and exists independently of direct friendship. This relationship was larger when extended contact was perceived versus actual, highlighting the importance of perception in extended contact. Current results on extended contact mostly resembled their direct friendship counterparts, suggesting similarity between these contact types. These unique insights about extended contact and its relationship with direct friendship should enrich and spur growth within this literature.

What to expect from an evolutionary hypothesis for a human disease: The case of type 2 diabetes.

PubMed

Watve, Milind; Diwekar-Joshi, Manawa

2016-10-01

Evolutionary medicine has a promise to bring in a conceptual revolution in medicine. However, as yet the field does not have the same theoretical rigour as that of many other fields in evolutionary studies. We discuss here with reference to type 2 diabetes mellitus (T2DM) what role an evolutionary hypothesis should play in the development of thinking in medicine. Starting with the thrifty gene hypothesis, evolutionary thinking in T2DM has undergone several transitions, modifications and refinements of the thrift family of hypotheses. In addition alternative hypotheses independent of thrift are also suggested. However, most hypotheses look at partial pictures; make selective use of supportive data ignoring inconvenient truths. Most hypotheses look at a superficial picture and avoid getting into the intricacies of underlying molecular, neuronal and physiological processes. Very few hypotheses have suggested clinical implications and none of them have been tested with randomized clinical trials. In the meanwhile the concepts in the pathophysiology of T2DM are undergoing radical changes and evolutionary hypotheses need to take them into account. We suggest an approach and a set of criteria to evaluate the relative merits of the alternative hypotheses. A number of hypotheses are likely to fail when critically evaluated against these criteria. It is possible that more than one selective process are at work in the evolution of propensity to T2DM, but the intercompatibility of the alternative selective forces and their relative contribution needs to be examined. The approach we describe could potentially lead to a sound evolutionary theory that is clinically useful and testable by randomized controlled clinical trials. Copyright © 2016 Elsevier GmbH. All rights reserved.

Maternal depression and trait anger as risk factors for escalated physical discipline.

PubMed

Shay, Nicole L; Knutson, John F

2008-02-01

To test the hypothesized anger-mediated relation between maternal depression and escalation of physical discipline, 122 economically disadvantaged mothers were assessed for current and lifetime diagnoses of depression using the Current Depressive Episode, Past Depression, and Dysthymia sections of the Structured Clinical Interview for DSM-IV (SCID) and a measure of current depressive symptoms, the Beck Depression Inventory-Second Edition (BDI-II). Escalation of physical discipline was assessed using a video analog parenting task; maternal anger not specific to discipline was assessed using the Spielberger Trait Anger Expression Inventory. Reports of anger were associated with the diagnosis of depression and depressive symptoms. Bootstrap analyses of indirect effects indicated that the link between depression and escalated discipline was mediated by anger. Parallel analyses based on BDI-II scores identified a marginally significant indirect effect of depression on discipline. Findings suggest that anger and irritability are central to the putative link between depression and harsh discipline.

HyQue: evaluating hypotheses using Semantic Web technologies

PubMed Central

2011-01-01

Background Key to the success of e-Science is the ability to computationally evaluate expert-composed hypotheses for validity against experimental data. Researchers face the challenge of collecting, evaluating and integrating large amounts of diverse information to compose and evaluate a hypothesis. Confronted with rapidly accumulating data, researchers currently do not have the software tools to undertake the required information integration tasks. Results We present HyQue, a Semantic Web tool for querying scientific knowledge bases with the purpose of evaluating user submitted hypotheses. HyQue features a knowledge model to accommodate diverse hypotheses structured as events and represented using Semantic Web languages (RDF/OWL). Hypothesis validity is evaluated against experimental and literature-sourced evidence through a combination of SPARQL queries and evaluation rules. Inference over OWL ontologies (for type specifications, subclass assertions and parthood relations) and retrieval of facts stored as Bio2RDF linked data provide support for a given hypothesis. We evaluate hypotheses of varying levels of detail about the genetic network controlling galactose metabolism in Saccharomyces cerevisiae to demonstrate the feasibility of deploying such semantic computing tools over a growing body of structured knowledge in Bio2RDF. Conclusions HyQue is a query-based hypothesis evaluation system that can currently evaluate hypotheses about the galactose metabolism in S. cerevisiae. Hypotheses as well as the supporting or refuting data are represented in RDF and directly linked to one another allowing scientists to browse from data to hypothesis and vice versa. HyQue hypotheses and data are available at http://semanticscience.org/projects/hyque. PMID:21624158

Better executive function under stress mitigates the effects of recent life stress exposure on health in young adults

PubMed Central

Shields, Grant S.; Moons, Wesley G.; Slavich, George M.

2017-01-01

Executive function is a neuropsychological construct that enables controlled cognitive processing, which has been hypothesized to enhance individuals’ resilience to stress. However, little empirical work has directly examined how executive function under different conditions mitigates the negative effects of stress exposure on health. To address this issue, we recruited 110 healthy young adults and assessed their recent life stress exposure, executive function in either a stressful or non-stressful context, and current health complaints. Based on existing research, we hypothesized that individuals exhibiting better executive function following a laboratory-based stressor (but not a control task) would demonstrate weaker associations between recent stress exposure and health because they perceived recent life stressors as being less severe. Consistent with this hypothesis, better executive function during acute stress, but not in the absence of stress, was associated with an attenuated link between participants’ recent life stress exposure and their current health complaints. Moreover, this attenuating effect was mediated by lesser perceptions of stressor severity. Based on these data, we conclude that better executive function under stress is associated with fewer health complaints and that these effects may occur by reducing individuals’ perceptions of stressor severity. The data thus suggest the possibility of reducing stress-related health problems by enhancing executive function. PMID:28114849

Better executive function under stress mitigates the effects of recent life stress exposure on health in young adults.

PubMed

Shields, Grant S; Moons, Wesley G; Slavich, George M

2017-01-01

Executive function is a neuropsychological construct that enables controlled cognitive processing, which has been hypothesized to enhance individuals' resilience to stress. However, little empirical work has directly examined how executive function under different conditions mitigates the negative effects of stress exposure on health. To address this issue, we recruited 110 healthy young adults and assessed their recent life stress exposure, executive function in either a stressful or non-stressful context, and current health complaints. Based on existing research, we hypothesized that individuals exhibiting better executive function following a laboratory-based stressor (but not a control task) would demonstrate weaker associations between recent stress exposure and health because they perceived recent life stressors as being less severe. Consistent with this hypothesis, better executive function during acute stress, but not in the absence of stress, was associated with an attenuated link between participants' recent life stress exposure and their current health complaints. Moreover, this attenuating effect was mediated by lesser perceptions of stressor severity. Based on these data, we conclude that better executive function under stress is associated with fewer health complaints and that these effects may occur by reducing individuals' perceptions of stressor severity. The data thus suggest the possibility of reducing stress-related health problems by enhancing executive function.

Rejection Sensitivity, Jealousy, and the Relationship to Interpersonal Aggression.

PubMed

Murphy, Anna M; Russell, Gemma

2018-07-01

The development and maintenance of interpersonal relationships lead individuals to risk rejection in the pursuit of acceptance. Some individuals are predisposed to experience a hypersensitivity to rejection that is hypothesized to be related to jealous and aggressive reactions within interpersonal relationships. The current study used convenience sampling to recruit 247 young adults to evaluate the relationship between rejection sensitivity, jealousy, and aggression. A mediation model was used to test three hypotheses: Higher scores of rejection sensitivity would be positively correlated to higher scores of aggression (Hypothesis 1); higher scores of rejection sensitivity would be positively correlated to higher scores of jealousy (Hypothesis 2); jealousy would mediate the relationship between rejection sensitivity and aggression (Hypothesis 3). Study results suggest a tendency for individuals with high rejection sensitivity to experience higher levels of jealousy, and subsequently have a greater propensity for aggression, than individuals with low rejection sensitivity. Future research that substantiates a link between hypersensitivity to rejection, jealousy, and aggression may provide an avenue for prevention, education, or intervention in reducing aggression within interpersonal relationships.

Gender dysphoria and autism spectrum disorder: A narrative review.

PubMed

Van Der Miesen, Anna I R; Hurley, Hannah; De Vries, Annelou L C

2016-01-01

The current literature shows growing evidence of a link between gender dysphoria (GD) and autism spectrum disorder (ASD). This study reviews the available clinical and empirical data. A systematic search of the literature was conducted using the following databases: PubMed, Web of Science, PsycINFO and Scopus; utilizing different combinations of the following search terms: autism, autism spectrum disorder (ASD), Asperger's disorder (AD), co-morbidity, gender dysphoria (GD), gender identity disorder (GID), transgenderism and transsexualism. In total, 25 articles and reports were selected and discussed. Information was grouped by found co-occurrence rates, underlying hypotheses and implications for diagnosis and treatment. GD and ASD were found to co-occur frequently - sometimes characterized by atypical presentation of GD, which makes a correct diagnosis and determination of treatment options for GD difficult. Despite these challenges there are several case reports describing gender affirming treatment of co-occurring GD in adolescents and adults with ASD. Various underlying hypotheses for the link between GD and ASD were suggested, but almost all of them lack evidence.

A Meta-Analytic Review of the Relationships Between the Five-Factor Model and DSM-IV-TR Personality Disorders: A Facet Level Analysis

PubMed Central

Samuel, Douglas B.; Widiger, Thomas A.

2008-01-01

Theory and research have suggested that the personality disorders contained within the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR) can be understood as maladaptive variants of the personality traits included within the five-factor model (FFM). The current meta-analysis of FFM personality disorder research both replicated and extended the 2004 work of Saulsman and Page (The five-factor model and personality disorder empirical literature: A meta-analytic review. Clinical Psychology Review, 23, 1055-1085) through a facet-level analysis that provides a more specific and nuanced description of each DSM-IV-TR personality disorder. The empirical FFM profiles generated for each personality disorder were generally congruent at the facet level with hypothesized FFM translations of the DSM-IV-TR personality disorders. However, notable exceptions to the hypotheses did occur and even some findings that were consistent with FFM theory could be said to be instrument specific. PMID:18708274

Intracranial and Intraocular Pressure at the Lamina Cribrosa: Gradient Effects.

PubMed

Jóhannesson, Gauti; Eklund, Anders; Lindén, Christina

2018-04-12

A pressure difference between the intraocular and intracranial compartments at the site of the lamina cribrosa has been hypothesized to have a pathophysiological role in several optic nerve head diseases. This paper reviews the current literature on the translamina cribrosa pressure difference (TLCPD), the associated pressure gradient, and its potential pathophysiological role, as well as the methodology to assess TLCPD. For normal-tension glaucoma (NTG), initial studies indicated low intracranial pressure (ICP) while recent findings indicate that a reduced ICP is not mandatory. Data from studies on the elevated TLCPD as a pathophysiological factor of NTG are equivocal. From the identification of potential postural effects on the cerebrospinal fluid (CSF) communication between the intracranial and retrolaminar space, we hypothesize that the missing link could be a dysfunction of an occlusion mechanism of the optic nerve sheath around the optic nerve. In upright posture, this could cause an elevated TLCPD even with normal ICP and we suggest that this should be investigated as a pathophysiological component in NTG patients.

Islands in the ice stream: were spawning habitats for native salmonids in the Great Lakes created by paleo-ice streams?

USGS Publications Warehouse

Riley, Stephen; Binder, Thomas R.; Tucker, Taaja R.; Menzies, John; Eyles, Nick; Janssen, John; Muir, Andrew M.; Esselman, Peter C.; Wattrus, Nigel J.; Krueger, Charles C.

2016-01-01

Lake trout Salvelinus namaycush, lake whitefish Coregonus clupeaformis and cisco Coregonus artedi are salmonid fishes native to the Laurentian Great Lakes that spawn on rocky substrates in the fall and early winter. After comparing the locations of spawning habitat for these species in the main basin of Lake Huron with surficial substrates and the hypothesized locations of fast-flowing Late Wisconsinan paleo-ice streams, we hypothesize that much of the spawning habitat for these species in Lake Huron is the result of deposition and erosion by paleo-ice streams. This hypothesis may represent a new framework for the identification and protection of spawning habitat for these native species, some of which are currently rare or extirpated in some of the Great Lakes. We further suggest that paleo-ice streams may have been responsible for the creation of native salmonid spawning habitat elsewhere in the Great Lakes and in other glaciated landscapes.

Hippocampal Replay is Not a Simple Function of Experience

PubMed Central

Gupta, Anoopum S.; van der Meer, Matthijs A. A.; Touretzky, David S.; Redish, A. David

2015-01-01

Summary Replay of behavioral sequences in the hippocampus during sharp-wave-ripple-complexes (SWRs) provides a potential mechanism for memory consolidation and the learning of knowledge structures. Current hypotheses imply that replay should straightforwardly reflect recent experience. However, we find these hypotheses to be incompatible with the content of replay on a task with two distinct behavioral sequences (A&B). We observed forward and backward replay of B even when rats had been performing A for >10 minutes. Furthermore, replay of non-local sequence B occurred more often when B was infrequently experienced. Neither forward nor backward sequences preferentially represented highly-experienced trajectories within a session. Additionally, we observed the construction of never-experienced novel-path sequences. These observations challenge the idea that sequence activation during SWRs is a simple replay of recent experience. Instead, replay reflected all physically available trajectories within the environment, suggesting a potential role in active learning and maintenance of the cognitive map. PMID:20223204

Motivation and personality: relationships between putative motive dimensions and the five factor model of personality.

PubMed

Bernard, Larry C

2010-04-01

There are few multidimensional measures of individual differences in motivation available. The Assessment of Individual Motives-Questionnaire assesses 15 putative dimensions of motivation. The dimensions are based on evolutionary theory and preliminary evidence suggests the motive scales have good psychometric properties. The scales are reliable and there is evidence of their consensual validity (convergence of self-other ratings) and behavioral validity (relationships with self-other reported behaviors of social importance). Additional validity research is necessary, however, especially with respect to current models of personality. The present study tested two general and 24 specific hypotheses based on proposed evolutionary advantages/disadvantages and fitness benefits/costs of the five-factor model of personality together with the new motive scales in a sample of 424 participants (M age=28.8 yr., SD=14.6). Results were largely supportive of the hypotheses. These results support the validity of new motive dimensions and increase understanding of the five-factor model of personality.

Leveraging biomedical ontologies and annotation services to organize microbiome data from Mammalian hosts.

PubMed

Sarkar, Indra Neil

2010-11-13

A better understanding of commensal microbiotic communities ("microbiomes") may provide valuable insights to human health. Towards this goal, an essential step may be the development of approaches to organize data that can enable comparative hypotheses across mammalian microbiomes. The present study explores the feasibility of using existing biomedical informatics resources - especially focusing on those available at the National Center for Biomedical Ontology - to organize microbiome data contained within large sequence repositories, such as GenBank. The results indicate that the Foundational Model of Anatomy and SNOMED CT can be used to organize greater than 90% of the bacterial organisms associated with 10 domesticated mammalian species. The promising findings suggest that the current biomedical informatics infrastructure may be used towards the organizing of microbiome data beyond humans. Furthermore, the results identify key concepts that might be organized into a semantic structure for incorporation into subsequent annotations that could facilitate comparative biomedical hypotheses pertaining to human health.

Living With Limited Time: Socioemotional Selectivity Theory in the Context of Health Adversity

PubMed Central

Sullivan-Singh, Sarah J.; Stanton, Annette L.; Low, Carissa A.

2016-01-01

The current research was designed to test the applicability of socioemotional selectivity theory (SST; Carstensen, 2006), a life span theory that posits that perceived time remaining in life (time perspective) is a critical determinant of motivation, to individuals who face foreshortened futures (limited time perspective) due to life-limiting medical illness. In Study 1, we investigated whether life goals and biases in attention and memory for valenced emotional stimuli differed between women living with metastatic breast cancer (n = 113; theoretically living under greater limited time perspective than peers without cancer) and similarly aged women without a cancer diagnosis (n = 50; theoretically living under greater expansive time perspective than peers with cancer) in accordance with SST. As hypothesized, metastatic group goals reflected greater emphasis on limited versus expansive time perspective relative to comparison group goals. Hypotheses regarding biases in attention and memory were not supported. Study 2 followed metastatic group participants over 3 months and revealed that, consistent with hypotheses, whereas limited time perspective goals predicted decreased intrusive thoughts about cancer, expansive time perspective goals predicted decreased perceived cancer-related benefits. Together, these studies suggest that SST is a useful lens through which to view some components of motivation and psychological adjustment among individuals confronting medically foreshortened futures. PMID:25984789

Living with limited time: Socioemotional selectivity theory in the context of health adversity.

PubMed

Sullivan-Singh, Sarah J; Stanton, Annette L; Low, Carissa A

2015-06-01

The current research was designed to test the applicability of socioemotional selectivity theory (SST; Carstensen, 2006), a life span theory that posits that perceived time remaining in life (time perspective) is a critical determinant of motivation, to individuals who face foreshortened futures (limited time perspective) due to life-limiting medical illness. In Study 1, we investigated whether life goals and biases in attention and memory for valenced emotional stimuli differed between women living with metastatic breast cancer (n = 113; theoretically living under greater limited time perspective than peers without cancer) and similarly aged women without a cancer diagnosis (n = 50; theoretically living under greater expansive time perspective than peers with cancer) in accordance with SST. As hypothesized, metastatic group goals reflected greater emphasis on limited versus expansive time perspective relative to comparison group goals. Hypotheses regarding biases in attention and memory were not supported. Study 2 followed metastatic group participants over 3 months and revealed that, consistent with hypotheses, whereas limited time perspective goals predicted decreased intrusive thoughts about cancer, expansive time perspective goals predicted decreased perceived cancer-related benefits. Together, these studies suggest that SST is a useful lens through which to view some components of motivation and psychological adjustment among individuals confronting medically foreshortened futures. (c) 2015 APA, all rights reserved).

Working memory effects of gap-predictions in normal adults: an event-related potentials study.

PubMed

Hestvik, Arild; Bradley, Evan; Bradley, Catherine

2012-12-01

The current study examined the relationship between verbal memory span and the latency with which a filler-gap dependency is constructed. A previous behavioral study found that low span listeners did not exhibit antecedent reactivation at gap sites in relative clauses, in comparison to high verbal memory span subjects (Roberts et al. in J Psycholinguist Res 36(2):175-188, 2007), which suggests that low span subjects are delayed at gap filling. This possibility was examined in the current study. Using an event-related potentials paradigm, it was found that low span subjects have an onset latency delay of about 200 ms in brain responses to violations of syntactic expectancies after the gap site, thus providing a time course measure of the delay hypothesized by previous literature.

Can Soft Drink Taxes Reduce Population Weight?

PubMed Central

Fletcher, Jason M.; Frisvold, David

2009-01-01

Soft drink consumption has been hypothesized as one of the major factors in the growing rates of obesity in the US. Nearly two-thirds of all states currently tax soft drinks using excise taxes, sales taxes, or special exemptions to food exemptions from sales taxes to reduce consumption of this product, raise revenue, and improve public health. In this paper, we evaluate the impact of changes in state soft drink taxes on body mass index (BMI), obesity, and overweight. Our results suggest that soft drink taxes influence BMI, but that the impact is small in magnitude. PMID:20657817

Transcranial magnetic stimulation: physics, electrophysiology, and applications.

PubMed

Fatemi-Ardekani, Ali

2008-01-01

Transcranial magnetic stimulation (TMS) is a noninvasive technique used to stimulate the brain. This review will examine the fundamental principles of physics upon which magnetic stimulation is based, the design considerations of the TMS device, and hypotheses about its electrophysiological effects resulting in neuromodulation. TMS is valuable in neurophysiology research and has significant therapeutic potential in clinical neurology and psychiatry. While TMS can modify neuronal currents in the brain, its underlying mechanism remains unknown. Salient applications are included and some suggestions are outlined for future development of magnetic stimulators that could lead to more effective neuronal stimulation and therefore better therapeutic and diagnostic applications.

Role of A-type potassium currents in excitability, network synchronicity and epilepsy

PubMed Central

Fransén, Erik; Tigerholm, Jenny

2011-01-01

A range of ionic currents have been suggested to be involved in distinct aspects of epileptogenesis. Based on pharmacological and genetic studies, potassium currents have been implicated, in particular the transient A-type potassium current (KA). Epileptogenic activity comprises a rich repertoire of characteristics, one of which is synchronized activity of principal cells as revealed by occurrences of for instance fast ripples. Synchronized activity of this kind is particularly efficient in driving target cells into spiking. In the recipient cell, this synchronized input generates large brief compound EPSPs. The fast activation and inactivation of KA lead us to hypothesize a potential role in suppression of such EPSPs. In this work, using computational modeling, we have studied the activation of KA by synaptic inputs of different levels of synchronicity. We find that KA participates particularly in suppressing inputs of high synchronicity. We also show that the selective suppression stems from the current's ability to become activated by potentials with high slopes. We further show that KA suppresses input mimicing the activity of a fast ripple. Finally, we show that the degree of selectivity of KA can be modified by changes to its kinetic parameters, changes of the type that are produced by the modulatory action of KChIPs and DPPs. We suggest that the wealth of modulators affecting KA might be explained by a need to control cellular excitability in general and suppression of responses to synchronicity in particular. We also suggest that compounds changing KA-kinetics may be used to pharmacologically improve epileptic status. PMID:19777555

Molecular Phylogenies indicate a Paleo-Tibetan Origin of Himalayan Lazy Toads (Scutiger).

PubMed

Hofmann, Sylvia; Stöck, Matthias; Zheng, Yuchi; Ficetola, Francesco G; Li, Jia-Tang; Scheidt, Ulrich; Schmidt, Joachim

2017-06-12

The Himalaya presents an outstanding geologically active orogen and biodiversity hotspot. However, our understanding of the historical biogeography of its fauna is far from comprehensive. Many taxa are commonly assumed to have originated from China-Indochina and dispersed westward along the Himalayan chain. Alternatively, the "Tibetan-origin hypothesis" suggests primary diversification of lineages in Paleo-Tibet, and secondary diversification along the slopes of the later uplifted Greater Himalaya. We test these hypotheses in high-mountain megophryid anurans (Scutiger). Extensive sampling from High Asia, and analyses of mitochondrial (2839 bp) and nuclear DNA (2208 bp), using Bayesian and Maximum likelihood phylogenetics, suggest that the Himalayan species form a distinct clade, possibly older than those from the eastern Himalaya-Tibet orogen. While immigration from China-Indochina cannot be excluded, our data may indicate that Himalayan Scutiger originated to the north of the Himalaya by colonization from Paleo-Tibet and then date back to the Oligocene. High intraspecific diversity of Scutiger implies limited migration across mountains and drainages along the Himalaya. While our study strengthens support for a "Tibetan-origin hypothesis", current sampling (10/22 species; 1 revalidated: S. occidentalis) remains insufficient to draw final conclusions on Scutiger but urges comparative phylogeographers to test alternative, geologically supported hypotheses for a true future understanding of Himalayan biogeography.

Sources of variation in breeding-ground fidelity of mallards (Anas platyrhynchos)

USGS Publications Warehouse

Doherty, P.F.; Nichols, J.D.; Tautin, J.; Voelzer, J.E.; Smith, G.W.; Benning, D.S.; Bentley, V.R.; Bidwell, J.K.; Bollinger, K.S.; Brazda, A.R.; Buelna, E.K.; Goldsberry, J.R.; King, R.J.; Roetker, F.H.; Solberg, J.W.; Thorpe, P.P.; Wortham, J.S.

2002-01-01

Generalizations used to support hypotheses about the evolution of fidelity to breeding areas in birds include the tendency for fidelity to be greater in adult birds than in yearlings. In ducks, in contrast to most bird species, fidelity is thought to be greater among females than males. Researchers have suggested that fidelity in ducks is positively correlated with pond availability. However, most estimates of fidelity on which these inferences have been based represent functions of survival and recapture-resighting probabilities in addition to fidelity. We applied the modeling approach developed by Burnham to recapture and band recovery data of mallard ducks to test the above hypotheses about fidelity. We found little evidence of sex differences in adult philopatry, with females being slightly more philopatric than males in one study area, but not in a second study area. However, yearling females were more philopatric than yearling males in both study areas. We found that adults were generally more philopatric than yearlings. We could find no relationship between fidelity and pond availability. Our results, while partially supporting current theory concerning sex and age differences in philopatry, suggest that adult male mallards are more philopatric than once thought, and we recommend that other generalizations about philopatry be revisited with proper estimation techniques.

The effects of testosterone on immune function in quail selected for divergent plasma corticosterone response.

PubMed

Roberts, Mark L; Buchanan, Katherine L; Evans, Matthew R; Marin, Raul H; Satterlee, Daniel G

2009-10-01

The immunocompetence handicap hypothesis (ICHH) suggests that the male sex hormone testosterone has a dual effect; it controls the development and expression of male sexually selected signals, and it suppresses the immune system. Therefore only high quality males are able to fully express secondary sexual traits because only they can tolerate the immunosuppressive qualities of testosterone. A modified version of the ICHH suggests that testosterone causes immunosuppression indirectly by increasing the stress hormone corticosterone (CORT). Lines of Japanese quail (Coturnix japonica) selected for divergent responses in levels of plasma CORT were used to test these hypotheses. Within each CORT response line (as well as in a control stock) we manipulated levels of testosterone in castrated quail by treatment with zero (sham), low or high testosterone implants, before testing the birds' humoral immunity and phytohaemagglutinin (PHA)-induced immune response, as well as body condition. The PHA-induced response was not significantly affected by CORT selected line, testosterone treatment or their interaction. There was, however, a significant effect of CORT line on humoral immunity in that the control birds exhibited the greatest antibody production, but there was no significant effect of testosterone manipulation on humoral immunity. The males in the sham implant treatment group had significantly greater mass than the males in the high testosterone group, suggesting a negative effect of high testosterone on general body condition. We discuss these results in the context of current hypotheses in the field of sexual selection.

Secondary metabolites extracted from marine sponge associated Comamonas testosteroni and Citrobacter freundii as potential antimicrobials against MDR pathogens and hypothetical leads for VP40 matrix protein of Ebola virus: an in vitro and in silico investigation.

PubMed

Skariyachan, Sinosh; Acharya, Archana B; Subramaniyan, Saumya; Babu, Sumangala; Kulkarni, Shruthi; Narayanappa, Rajeswari

2016-09-01

The current study explores therapeutic potential of metabolites extracted from marine sponge (Cliona sp.)-associated bacteria against MDR pathogens and predicts the binding prospective of probable lead molecules against VP40 target of Ebola virus. The metabolite-producing bacteria were characterized by agar overlay assay and as per the protocols in Bergey's manual of determinative bacteriology. The antibacterial activities of extracted metabolites were tested against clinical pathogens by well-diffusion assay. The selected metabolite producers were characterized by 16S rDNA sequencing. Chemical screening and Fourier Transform Infrared (FTIR) analysis for selected compounds were performed. The probable lead molecules present in the metabolites were hypothesized based on proximate analysis, FTIR data, and literature survey. The drug-like properties and binding potential of lead molecules against VP40 target of Ebola virus were hypothesized by computational virtual screening and molecular docking. The current study demonstrated that clear zones around bacterial colonies in agar overlay assay. Antibiotic sensitivity profiling demonstrated that the clinical isolates were multi-drug resistant, however; most of them showed sensitivity to secondary metabolites (MIC-15 μl/well). The proximate and FTIR analysis suggested that probable metabolites belonged to alkaloids with O-H, C-H, C=O, and N-H groups. 16S rDNA characterization of selected metabolite producers demonstrated that 96% and 99% sequence identity to Comamonas testosteroni and Citrobacter freundii, respectively. The docking studies suggested that molecules such as Gymnastatin, Sorbicillactone, Marizomib, and Daryamide can designed as probable lead candidates against VP40 target of Ebola virus.

Intrinsic motivation, performance, and the mediating role of mastery goal orientation: a test of self-determination theory.

PubMed

Cerasoli, Christopher P; Ford, Michael T

2014-01-01

Although intrinsic motivation has been linked repeatedly to performance and outcomes, the causal relationship between the two has remained unclear. To explain the link, this study considered the focusing influence of mastery goals. Using a three-wave panel study and hypotheses drawn from self-determination theory and achievement goal theory, the current study sought to clarify the relationships between intrinsic motivation, mastery goal orientation, and performance. Specifically, the current study hypothesized and found that mastery goals mediated (explained) the relationship between intrinsic motivation and performance.

Conceptual Commitments of the LIDA Model of Cognition

NASA Astrophysics Data System (ADS)

Franklin, Stan; Strain, Steve; McCall, Ryan; Baars, Bernard

2013-06-01

Significant debate on fundamental issues remains in the subfields of cognitive science, including perception, memory, attention, action selection, learning, and others. Psychology, neuroscience, and artificial intelligence each contribute alternative and sometimes conflicting perspectives on the supervening problem of artificial general intelligence (AGI). Current efforts toward a broad-based, systems-level model of minds cannot await theoretical convergence in each of the relevant subfields. Such work therefore requires the formulation of tentative hypotheses, based on current knowledge, that serve to connect cognitive functions into a theoretical framework for the study of the mind. We term such hypotheses "conceptual commitments" and describe the hypotheses underlying one such model, the Learning Intelligent Distribution Agent (LIDA) Model. Our intention is to initiate a discussion among AGI researchers about which conceptual commitments are essential, or particularly useful, toward creating AGI agents.

Antecedents of eating disorders and muscle dysmorphia in a non-clinical sample.

PubMed

Lamanna, J; Grieve, F G; Derryberry, W Pitt; Hakman, M; McClure, A

2010-01-01

Muscle Dysmorphia (MD) has recently been conceptualized as the male form of Eating Disorders (ED); although, it is not currently classified as an ED. The current study compares etiological models of MD symptomatology and ED symptomatology. It was hypothesized that sociocultural influences on appearance (SIA) would predict body dissatisfaction (BD), and that this relationship would be mediated by self-esteem (SE) and perfectionism (P); that BD would predict negative affect (NA); and that NA would predict MD and ED symptomatology. Two-hundred-forty-seven female and 101 male college students at a midsouth university completed the study. All participants completed measures assessing each of the constructs, and multiple regression analyses were conducted to test each model's fit. In both models, most predictor paths were significant. These results suggest similarity in symptomatology and etiological models between ED and MD.

Niche syndromes, species extinction risks, and management under climate change.

PubMed

Sax, Dov F; Early, Regan; Bellemare, Jesse

2013-09-01

The current distributions of species are often assumed to correspond with the total set of environmental conditions under which species can persist. When this assumption is incorrect, extinction risk estimated from species distribution models can be misleading. The degree to which species can tolerate or even thrive under conditions found beyond their current distributions alters extinction risks, time lags in realizing those risks, and the usefulness of alternative management strategies. To inform these issues, we propose a conceptual framework within which empirical data could be used to generate hypotheses regarding the realized, fundamental, and 'tolerance' niche of species. Although these niche components have rarely been characterized over geographic scales, we suggest that this could be done for many plant species by comparing native, naturalized, and horticultural distributions. Copyright © 2013 Elsevier Ltd. All rights reserved.

The RNA-world and co-evolution hypotheses and the origin of life: Implications, research strategies and perspectives

NASA Astrophysics Data System (ADS)

Lahav, Noam

1993-12-01

The applicability of the RNA-world and co-evolution hypotheses to the study of the very first stages of the origin of life is discussed. The discussion focuses on the basic differences between the two hypotheses and their implications, with regard to the reconstruction methodology, ribosome emergence, balance between ribozymes and protein enzymes, and their major difficulties. Additional complexities of the two hypotheses, such as membranes and the energy source of the first reactions, are not treated in the present work. A central element in the proposed experimental strategies is the study of the catalytic activities of very small peptides and RNA-like oligomers, according to existing, as well as to yet-to-be-invented scenarios of the two hypotheses under consideration. It is suggested that the noveldirected molecular evolution technology, andmolecular computational modeling, can be applied to this research. This strategy is assumed to be essential for the suggested goal of future studies of the origin of life, namely, the establishment of a ‘Primordial Darwinian entity’.

Social media e-cigarette exposure and e-cigarette expectancies and use among young adults.

PubMed

Pokhrel, Pallav; Fagan, Pebbles; Herzog, Thaddeus A; Laestadius, Linnea; Buente, Wayne; Kawamoto, Crissy T; Lee, Hye-Ryeon; Unger, Jennifer B

2018-03-01

A vast majority of U.S. young adults use social media such as Facebook and Instagram daily. Research suggests that young adults are commonly exposed to e-cigarette-related marketing or user-generated content on the social media they use. Currently, however, there is limited empirical evidence as to how social media e-cigarette exposure is associated with e-cigarette use beliefs and behavior. In particular, limited evidence exists to support the proposition that social media e-cigarette exposure is uniquely associated with e-cigarette use, even after adjusting for the effects of e-cigarette use in young adults' in-person or 'offline' social networks. This study was conducted to test the hypotheses that 1) social media e-cigarette exposure is associated with e-cigarette use outcome expectancies and current e-cigarette use; and 2) the association between social media and e-cigarette use is linked via outcome expectancies. We collected cross-sectional data from a sample of 470 young adult college students in Hawaii. Hypotheses were tested by fitting a structural equation model to the data. The model accounted for the associations of demographic variables, cigarette smoking history, as well as e-cigarette use in individuals' actual social networks with expectancies and behavior. Results indicated that social media e-cigarette exposure was associated with current e-cigarette use indirectly through two of the four positive outcome expectancies examined, namely, positive "smoking" experience and positive sensory experience. We discuss the implications of the findings in the context of tobacco control efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

An integrated network of Arabidopsis growth regulators and its use for gene prioritization.

PubMed

Sabaghian, Ehsan; Drebert, Zuzanna; Inzé, Dirk; Saeys, Yvan

2015-12-01

Elucidating the molecular mechanisms that govern plant growth has been an important topic in plant research, and current advances in large-scale data generation call for computational tools that efficiently combine these different data sources to generate novel hypotheses. In this work, we present a novel, integrated network that combines multiple large-scale data sources to characterize growth regulatory genes in Arabidopsis, one of the main plant model organisms. The contributions of this work are twofold: first, we characterized a set of carefully selected growth regulators with respect to their connectivity patterns in the integrated network, and, subsequently, we explored to which extent these connectivity patterns can be used to suggest new growth regulators. Using a large-scale comparative study, we designed new supervised machine learning methods to prioritize growth regulators. Our results show that these methods significantly improve current state-of-the-art prioritization techniques, and are able to suggest meaningful new growth regulators. In addition, the integrated network is made available to the scientific community, providing a rich data source that will be useful for many biological processes, not necessarily restricted to plant growth.

Perspectives for computational modeling of cell replacement for neurological disorders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aimone, James B.; Weick, Jason P.

In mathematical modeling of anatomically-constrained neural networks we provide significant insights regarding the response of networks to neurological disorders or injury. Furthermore, a logical extension of these models is to incorporate treatment regimens to investigate network responses to intervention. The addition of nascent neurons from stem cell precursors into damaged or diseased tissue has been used as a successful therapeutic tool in recent decades. Interestingly, models have been developed to examine the incorporation of new neurons into intact adult structures, particularly the dentate granule neurons of the hippocampus. These studies suggest that the unique properties of maturing neurons, can impactmore » circuit behavior in unanticipated ways. In this perspective, we review the current status of models used to examine damaged CNS structures with particular focus on cortical damage due to stroke. Secondly, we suggest that computational modeling of cell replacement therapies can be made feasible by implementing approaches taken by current models of adult neurogenesis. The development of these models is critical for generating hypotheses regarding transplant therapies and improving outcomes by tailoring transplants to desired effects.« less

Perspectives for computational modeling of cell replacement for neurological disorders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aimone, James B.; Weick, Jason P.

Mathematical modeling of anatomically-constrained neural networks has provided significant insights regarding the response of networks to neurological disorders or injury. A logical extension of these models is to incorporate treatment regimens to investigate network responses to intervention. The addition of nascent neurons from stem cell precursors into damaged or diseased tissue has been used as a successful therapeutic tool in recent decades. Interestingly, models have been developed to examine the incorporation of new neurons into intact adult structures, particularly the dentate granule neurons of the hippocampus. These studies suggest that the unique properties of maturing neurons, can impact circuit behaviormore » in unanticipated ways. In this perspective, we review the current status of models used to examine damaged CNS structures with particular focus on cortical damage due to stroke. Secondly, we suggest that computational modeling of cell replacement therapies can be made feasible by implementing approaches taken by current models of adult neurogenesis. The development of these models is critical for generating hypotheses regarding transplant therapies and improving outcomes by tailoring transplants to desired effects.« less

Interactions of Pannexin1 channels with purinergic and NMDA receptor channels.

PubMed

Li, Shuo; Bjelobaba, Ivana; Stojilkovic, Stanko S

2018-01-01

Pannexins are a three-member family of vertebrate plasma membrane spanning molecules that have homology to the invertebrate gap junction forming proteins, the innexins. However, pannexins do not form gap junctions but operate as plasma membrane channels. The best-characterized member of these proteins, Pannexin1 (Panx1) was suggested to be functionally associated with purinergic P2X and N-methyl-D-aspartate (NMDA) receptor channels. Activation of these receptor channels by their endogenous ligands leads to cross-activation of Panx1 channels. This in turn potentiates P2X and NMDA receptor channel signaling. Two potentiation concepts have been suggested: enhancement of the current responses and/or sustained receptor channel activation by ATP released through Panx1 pore and adenosine generated by ectonucleotidase-dependent dephosphorylation of ATP. Here we summarize the current knowledge and hypotheses about interactions of Panx1 channels with P2X and NMDA receptor channels. This article is part of a Special Issue entitled: Gap Junction Proteins edited by Jean Claude Herve. Published by Elsevier B.V.

Linking micro- and macroevolutionary perspectives to evaluate the role of Quaternary sea-level oscillations in island diversification.

PubMed

Papadopoulou, Anna; Knowles, L Lacey

2017-12-01

With shifts in island area, isolation, and cycles of island fusion-fission, the role of Quaternary sea-level oscillations as drivers of diversification is complex and not well understood. Here, we conduct parallel comparisons of population and species divergence between two island areas of equivalent size that have been affected differently by sea-level oscillations, with the aim to understand the micro- and macroevolutionary dynamics associated with sea-level change. Using genome-wide datasets for a clade of seven Amphiacusta ground cricket species endemic to the Puerto Rico Bank (PRB), we found consistently deeper interspecific divergences and higher population differentiation across the unfragmented Western PRB, in comparison to the currently fragmented Eastern PRB that has experienced extreme changes in island area and connectivity during the Quaternary. We evaluate alternative hypotheses related to the microevolutionary processes (population splitting, extinction, and merging) that regulate the frequency of completed speciation across the PRB. Our results suggest that under certain combinations of archipelago characteristics and taxon traits, the repeated changes in island area and connectivity may create an opposite effect to the hypothesized "species pump" action of oscillating sea levels. Our study highlights how a microevolutionary perspective can complement current macroecological work on the Quaternary dynamics of island biodiversity. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Role of the pituitary-adrenal hormones in the acquisition of schedule-induced polydipsia.

PubMed

Levine, R; Levine, S

1989-06-01

Adrenalectomized female rats failed to develop schedule-induced polydipsia (SIP). Dexamethasone (DEX) injections failed to reinstate SIP in adrenalectomized rats. They did not prevent intact rats from acquiring SIP but interfered with subsequent expression of this behavior. In contrast, corticosterone, the rats' normally occurring glucocorticoid, fully restored the acquisition and subsequent expression of SIP in adrenalectomized rats. This strongly suggests that corticosterone plays an essential role in the normal acquisition and development of this behavior. Data are interpreted in the context of current information concerning adrenal hormone receptors. It is hypothesized SIP acquisition is at least partly regulated by the Type I (mineralocorticoid) receptor.

Mathematical model of depolarization mechanism of conducted vasoreactivity

NASA Astrophysics Data System (ADS)

Neganova, Anastasiia Y.; Stiukhina, Elena S.; Postnov, Dmitry E.

2015-03-01

We address the problem of conducted vasodilation, the phenomenon which is also known as functional hyperemia. Specifically, we test the mechanism of nondecremental propagation of electric signals along endothelial cell layer recently hypothesized by Figueroa et al. By means of functional modeling we focus on possible nonlinear mechanisms that can underlie such regenerative pulse transmission (RPT). Since endothelial cells (EC) are generally known as electrically inexcitable, the possible role of ECs in RPT mechanisms is not evident. By means of mathematical modeling we check the dynamical self-consistency of Figueroa's hypothesis, as well as estimate the possible contribution of specific ionic currents to the suggested RPT mechanism.

Thinking of you: nonconscious pursuit of interpersonal goals associated with relationship partners.

PubMed

Fitzsimons, Gráinne M; Bargh, John A

2003-01-01

The mere psychological presence of relationship partners was hypothesized to trigger interpersonal goals that are then pursued nonconsciously. Qualitative data suggested that people tend to pursue different interpersonal goals within different types of relationships (e.g., mother, best friend, coworker). In several studies, priming participants' relationship representations produced goal-directed behavior (achievement, helping, understanding) in line with the previously assessed goal content of those representations. These findings support the hypothesis that interpersonal goals are component features of relationship representations and that mere activation of those representations, even in the partner's physical absence, causes the goals to become active and to guide behavior nonconsciously within the current situation.

Preliminary results from the hydrodynamic element of the 1994 entrapment zone study

USGS Publications Warehouse

Burau, J.R.; Stacey, M.; Gartner, J.W.

1995-01-01

This article discusses preliminary results from analyses of USGS hydrodynamic data collected as part of the 1994 Interagency Ecological Program entrapment zone study. The USGS took part in three 30-hour cruises and deployed instruments for measuring currents and salinity from April to June. This article primarily focuses on the analysis of data from five Acoustic Doppler Current ProUers (ADCPs) deployed in Carquinez Strait, Suisun Bay, and the Western Delta. From these analyses a revised conceptual model of the hydrodynamics of the entrapment/null zone has evolved. The ideas discussed in this newsletter article are essentially working hypotheses, which are presented here to stimulate discussion and further analyses. In this article we discuss the currently-held conceptual model of entrapment and present data that are inconsistent with this conceptual model. Finally, we suggest a revised conceptual model that is consistent with all of the hydrodynamic data collected to date and describe how the 1995 study incorporates our revised conceptual model into its design.

Maternal Depression and Trait Anger as Risk Factors for Escalated Physical Discipline

PubMed Central

Shay, Nicole L.; Knutson, John F.

2008-01-01

To test the hypothesized anger-mediated relation between maternal depression and escalation of physical discipline, 122 economically disadvantaged mothers were assessed for current and lifetime diagnoses of depression using the Current Depressive Episode, Past Depression, and Dysthymia sections of the Structured Clinical Interview for DSM-IV (SCID) and a measure of current depressive symptoms, the Beck Depression Inventory–Second Edition (BDI-II). Escalation of physical discipline was assessed using a video analog parenting task; maternal anger not specific to discipline was assessed using the Spielberger Trait Anger Expression Inventory. Reports of anger were associated with the diagnosis of depression and depressive symptoms. Bootstrap analyses of indirect effects indicated that the link between depression and escalated discipline was mediated by anger. Parallel analyses based on BDI-II scores identified a marginally significant indirect effect of depression on discipline. Findings suggest that anger and irritability are central to the putative link between depression and harsh discipline. PMID:18174347

An Outline of Technicisation Theory.

ERIC Educational Resources Information Center

Soheili, A.; Barjasteh, D.; Al Qadhi, Laila

2001-01-01

Proposes "technicisation" theory with five central hypotheses to account for various aspects of foreign students learning Technical English (TE), including its linguistic, learning, experiential, cultural, and motivational dimensions. Suggests that the fundamental hypotheses are applicable to TE learning but they may, mutatis mutandis,…

Stress and performance: do service orientation and emotional energy moderate the relationship?

PubMed

Smith, Michael R; Rasmussen, Jennifer L; Mills, Maura J; Wefald, Andrew J; Downey, Ronald G

2012-01-01

The current study examines the moderating effect of customer service orientation and emotional energy on the stress-performance relationship for 681 U.S. casual dining restaurant employees. Customer service orientation was hypothesized to moderate the stress-performance relationship for Front-of-House (FOH) workers. Emotional energy was hypothesized to moderate stress-performance for Back-of-House (BOH) workers. Contrary to expectations, customer service orientation failed to moderate the effects of stress on performance for FOH employees, but the results supported that customer service orientation is likely a mediator of the relationship. However, the hypothesis was supported for BOH workers; emotional energy was found to moderate stress performance for these employees. This finding suggests that during times of high stress, meaningful, warm, and empathetic relationships are likely to impact BOH workers' ability to maintain performance. These findings have real-world implications in organizational practice, including highlighting the importance of developing positive and meaningful social interactions among workers and facilitating appropriate person-job fits. Doing so is likely to help in alleviating worker stress and is also likely to encourage worker performance.

Happiness and age in European adults: The moderating role of gross domestic product per capita.

PubMed

Morgan, Jessica; Robinson, Oliver; Thompson, Trevor

2015-09-01

Studies of happiness levels across the life span have found support for two rival hypotheses. The positivity effect states that as people get older, they increasingly attend to positive information, which implies that happiness remains stable or increases with age, whereas the U-shaped hypothesis posits a curvilinear shape resulting from a dip during midlife. Both have been presented as potentially universal hypotheses that relate to cognitive and/or biological causes. The current study examined the happiness-age relationship across 29 European nations (N = 46,301) to explore whether it is moderated by national wealth, as indexed by Gross Domestic Product (GDP) per capita. It was found that eudaimonic and hedonic happiness remained relatively stable across the life span only in the most affluent nations; in poorer nations, there was either a fluctuating or steady age-associated decline. These findings challenge the cultural universality of the happiness-age relationship and suggest that models of how age relates to happiness should include the socioeconomic level of analysis. (c) 2015 APA, all rights reserved).

Preliminary Cosmogenic Surface Exposure Ages on Laurentide Ice-sheet Retreat and Opening of the Eastern Lake Agassiz Outlets

NASA Astrophysics Data System (ADS)

Leydet, D.; Carlson, A. E.; Sinclair, G.; Teller, J. T.; Breckenridge, A. J.; Caffee, M. W.; Barth, A. M.

2015-12-01

The chronology for the eastern outlets of glacial Lake Agassiz holds important consequences for the cause of Younger Dryas cold event during the last deglaciation. Eastward routing of Lake Agassiz runoff was originally hypothesized to have triggered the Younger Dryas. However, currently the chronology of the eastern outlets is only constrained by minimum-limiting radiocarbon ages that could suggest the eastern outlets were still ice covered at the start of the Younger Dryas at ~12.9 ka BP, requiring a different forcing of this abrupt climate event. Nevertheless, the oldest radiocarbon ages are still consistent with an ice-free eastern outlet at the start of the Younger Dryas. Here we will present preliminary 10-Be cosmogenic surface exposure ages from the North Lake, Flat Rock Lake, glacial Lake Kaministiquia, and Lake Nipigon outlets located near Thunder Bay, Ontario. These ages will date the timing of the deglaciation of the Laurentide ice sheet in the eastern outlet region of glacial Lake Agassiz. This will provide an important constraint for the hypothesized freshwater forcing of the cause of Younger Dryas cold event.

Turn the temperature to turquoise: cues for colour change in the male chameleon grasshopper (Kosciuscola tristis) (Orthoptera: Acrididae).

PubMed

Umbers, Kate D L

2011-09-01

Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis. Copyright © 2011 Elsevier Ltd. All rights reserved.

The development, evolution, and status of Holland's theory of vocational personalities: Reflections and future directions for counseling psychology.

PubMed

Nauta, Margaret M

2010-01-01

This article celebrates the 50th anniversary of the introduction of John L. Holland's (1959) theory of vocational personalities and work environments by describing the theory's development and evolution, its instrumentation, and its current status. Hallmarks of Holland's theory are its empirical testability and its user-friendliness. By constructing measures for operationalizing the theory's constructs, Holland and his colleagues helped ensure that the theory could be implemented in practice on a widespread basis. Empirical data offer considerable support for the existence of Holland's RIASEC types and their ordering among persons and environments. Although Holland's congruence hypotheses have received empirical support, congruence appears to have modest predictive power. Mixed support exists for Holland's hypotheses involving the secondary constructs of differentiation, consistency, and vocational identity. Evidence of the continued impact of Holland's theory on the field of counseling psychology, particularly in the area of interest assessment, can be seen from its frequent implementation in practice and its use by scholars. Ideas for future research and practice using Holland's theory are suggested.

Importance of exercise immunology in health promotion.

PubMed

Neto, J C Rosa; Lira, F S; de Mello, M T; Santos, Ronaldo Vagner T

2011-11-01

Chronic physical exercise with adequate intensity and volume associated with sufficient recovery promotes adaptations in several physiological systems. While intense and exhaustive exercise is considered an important immunosuppressor agent and increases the incidence of upper respiratory tract infections (URTI), moderate regular exercise has been associated with significant disease protection and is a complementary treatment of many chronic diseases. The effects of chronic exercise occur because physical training can induce several physiological, biochemical and psychological adaptations. More recently, the effect of acute exercise and training on the immunological system has been discussed, and many studies suggest the importance of the immune system in prevention and partial recovery in pathophysiological situations. Currently, there are two important hypotheses that may explain the effects of exercise and training on the immune system. These hypotheses including (1) the effect of exercise upon hormones and cytokines (2) because exercise can modulate glutamine concentration. In this review, we discuss the hypothesis that exercise may modulate immune functions and the importance of exercise immunology in respect to chronic illnesses, chronic heart failure, malnutrition and inflammation.

Controls on the global distribution of contourite drifts: Insights from an eddy-resolving ocean model

NASA Astrophysics Data System (ADS)

Thran, Amanda C.; Dutkiewicz, Adriana; Spence, Paul; Müller, R. Dietmar

2018-05-01

Contourite drifts are anomalously high sediment accumulations that form due to reworking by bottom currents. Due to the lack of a comprehensive contourite database, the link between vigorous bottom water activity and drift occurrence has yet to be demonstrated on a global scale. Using an eddy-resolving ocean model and a new georeferenced database of 267 contourites, we show that the global distribution of modern contourite drifts strongly depends on the configuration of the world's most powerful bottom currents, many of which are associated with global meridional overturning circulation. Bathymetric obstacles frequently modify flow direction and intensity, imposing additional finer-scale control on drift occurrence. Mean bottom current speed over contourite-covered areas is only slightly higher (2.2 cm/s) than the rest of the global ocean (1.1 cm/s), falling below proposed thresholds deemed necessary to re-suspend and redistribute sediments (10-15 cm/s). However, currents fluctuate more frequently and intensely over areas with drifts, highlighting the role of intermittent, high-energy bottom current events in sediment erosion, transport, and subsequent drift accumulation. We identify eddies as a major driver of these bottom current fluctuations, and we find that simulated bottom eddy kinetic energy is over three times higher in contourite-covered areas in comparison to the rest of the ocean. Our work supports previous hypotheses which suggest that contourite deposition predominantly occurs due to repeated acute events as opposed to continuous reworking under average-intensity background flow conditions. This suggests that the contourite record should be interpreted in terms of a bottom current's susceptibility to experiencing periodic, high-speed current events. Our results also highlight the potential role of upper ocean dynamics in contourite sedimentation through its direct influence on deep eddy circulation.

Change in drawing placement: A measure of change in mood state reflective of hemispheric lateralization of emotion.

PubMed

Butler, Tracy R; O'Mara, Erin M; Wilson, Josephine F

2018-04-26

The Valence Hypothesis of cerebral lateralization of emotion suggests greater right hemisphere activation during negative mood and greater left hemisphere activation during positive mood. This can manifest as visual field attentional bias. Here, study participants completed an assessment of current mood state (PANAS) and made a drawing (Drawing 1). To induce positive or negative mood, participants played a game; then, the winner read a script depicting a positive interpersonal interaction and the loser read a script depicting a negative interpersonal interaction. Participants then drew a second picture (Drawing 2) and completed the PANAS. We hypothesized that the game outcome would change current mood state and hemispheric activation, which would be reflected in drawing placement. The placement of Drawing 2 moved right for winners and left for losers. Winners experienced a greater increase in positive affect from Time 1 to Time 2 than losers and had decreased negative affect from Time 1. Losers had decreased positive affect from Time 1 and had a greater increase in negative affect from Time 1 to Time 2 than winners. Our results suggest that change in current mood state may be objectively observed by evaluating hemispatial bias reflective of brain hemispheric activation with drawings. Copyright © 2018 Elsevier Inc. All rights reserved.

The gender wealth gap:structural and material constraints and implications for later life.

PubMed

Denton, Margaret; Boos, Linda

2007-01-01

Wealth is an important measure of economic well-being, because while income captures the current state of inequality, wealth has the potential for examining accumulated and historically structured inequality. This presentation documents the extent of gender inequality in wealth for Canadian women and men aged 45 and older. The analysis uses data from the 1999 Canadian Survey of Financial Security, a large nationally representative survey of household wealth in Canada. Wealth is measured by total net worth as measured by total assets minus debt. We test two general hypotheses to account for gender differences in wealth. The differential exposure hypothesis suggests that women report less wealth accumulation because of their reduced access to the material and social conditions of life that foster economic security. The differential vulnerability hypothesis suggests that women report lower levels of wealth because they receive differential returns to material and social conditions of their lives. Support is found for both hypotheses. Much of the gender differences in wealth can be explained by the gendering of work and family roles that restricts women's ability to build up assets over the life course. But beyond this, there are significant gender interaction effects that indicate that women are further penalized by their returns to participation in family life, their health and where they live. When women do work, net of other factors, they are better able to accumulate wealth than their male counterparts.

White matter anisotropy in the ventral language pathway predicts sound-to-word learning success

PubMed Central

Wong, Francis C. K.; Chandrasekaran, Bharath; Garibaldi, Kyla; Wong, Patrick C. M.

2011-01-01

According to the dual stream model of auditory language processing, the dorsal stream is responsible for mapping sound to articulation while the ventral stream plays the role of mapping sound to meaning. Most researchers agree that the arcuate fasciculus (AF) is the neuroanatomical correlate of the dorsal steam, however, less is known about what constitutes the ventral one. Nevertheless two hypotheses exist, one suggests that the segment of the AF that terminates in middle temporal gyrus corresponds to the ventral stream and the other suggests that it is the extreme capsule that underlies this sound to meaning pathway. The goal of this study is to evaluate these two competing hypotheses. We trained participants with a sound-to-word learning paradigm in which they learned to use a foreign phonetic contrast for signaling word meaning. Using diffusion tensor imaging (DTI), a brain imaging tool to investigate white matter connectivity in humans, we found that fractional anisotropy in the left parietal-temporal region positively correlated with the performance in sound-to-word learning. In addition, fiber tracking revealed a ventral pathway, composed of the extreme capsule and the inferior longitudinal fasciculus, that mediated auditory comprehension. Our findings provide converging evidence supporting the importance of the ventral steam, an extreme capsule system, in the frontal-temporal language network. Implications for current models of speech processing will also be discussed. PMID:21677162

Planktonic Marine Iron-Oxidizers Drive Iron(III) Mineralization Under Low Oxygen Conditions

NASA Astrophysics Data System (ADS)

Luther, G. W., III; Field, E.; Findlay, A.; MacDonald, D. J.; Chan, C. S. Y.; Kato, S.

2016-02-01

Observations of modern microbes have led to several hypotheses on how microbes precipitated the extensive banded iron formations in the geologic record, but we have yet to resolve the exact microbial contributions. An initial hypotheses was that cyanobacteria produced oxygen that oxidized iron(II) abiotically; however, in modern environments such as microbial mats, where Fe(II) and O2 coexist, we commonly find microaerophilic chemolithotrophic iron(II)-oxidizing bacteria producing Fe(III) oxyhydroxides. This suggests that such iron-oxidizers could have inhabited niches in ancient coastal oceans where Fe(II) and O2 coexisted, and therefore contributed to iron deposits, but there is currently little evidence for planktonic marine iron-oxidizers in modern analogs. Here, we demonstrate successful cultivation of planktonic microaerophilic iron-oxidizing Zetaproteobacteria from the Chesapeake Bay during seasonal stratification. Iron-oxidizers were associated with low oxygen concentrations and active iron redox cycling in the oxic-anoxic transition zone (<3 µM O2, <0.2 µM H2S). While cyanobacteria were also detected in this transition zone, oxygen concentrations were too low to support significant rates of abiotic iron oxidation. Instead, cyanobacteria may be providing oxygen for microaerophilic iron(II) oxidation through a symbiotic relationship that promotes oxygen consumption rather than build-up. Our results suggest that once oxygenic photosynthesis evolved, microaerophilic chemolithotrophic iron(II)-oxidizers were likely important drivers of iron(III) mineralization in ancient oceans.

Landscape moderation of biodiversity patterns and processes - eight hypotheses

USDA-ARS?s Scientific Manuscript database

Understanding how landscape characteristics affect local biodiversity patterns and ecological processes is critical for mitigating effects of global environmental change. In this review, we use knowledge gained from human-modified landscapes to suggest the following seven hypotheses, which we hope w...

Neural basis of major depressive disorder: Beyond monoamine hypothesis.

PubMed

Boku, Shuken; Nakagawa, Shin; Toda, Hiroyuki; Hishimoto, Akitoyo

2018-01-01

The monoamine hypothesis has been accepted as the most common hypothesis of major depressive disorder (MDD) for a long period because of its simplicity and understandability. Actually, most currently used antidepressants have been considered to act based on the monoamine hypothesis. However, an important problem of the monoamine hypothesis has been pointed out as follows: it fails to explain the latency of response to antidepressants. In addition, many patients with MDD have remained refractory to currently used antidepressants. Therefore, monoamine-alternate hypotheses are required to explain the latency of response to antidepressants. Such hypotheses have been expected to contribute to identifying hopeful new therapeutic targets for MDD. Past studies have revealed that the volume of the hippocampus is decreased in patients with MDD, which is likely caused by the failure of the hypothalamic-pituitary-adrenal axis and following elevation of glucocorticoids. Two hypotheses have been proposed to explain the volume of the hippocampus: (i) the neuroplasticity hypothesis; and (ii) the neurogenesis hypothesis. The neuroplasticity hypothesis explains how the hippocampal volume is decreased by the morphological changes of hippocampal neurons, such as the shortening length of dendrites and the decreased number and density of spines. The neurogenesis hypothesis explains how the hippocampal volume is decreased by the decrease of neurogenesis in the hippocampal dentate gyrus. These hypotheses are able to explain the latency of response to antidepressants. In this review, we first overview how the neuroplasticity and neurogenesis hypotheses have been developed. We then describe the details of these hypotheses. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

TOWARD CHEMICAL CONSTRAINTS ON HOT JUPITER MIGRATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madhusudhan, Nikku; Amin, Mustafa A.; Kennedy, Grant M., E-mail: nmadhu@ast.cam.ac.uk

The origin of hot Jupiters—gas giant exoplanets orbiting very close to their host stars—is a long-standing puzzle. Planet formation theories suggest that such planets are unlikely to have formed in situ but instead may have formed at large orbital separations beyond the snow line and migrated inward to their present orbits. Two competing hypotheses suggest that the planets migrated either through interaction with the protoplanetary disk during their formation, or by disk-free mechanisms such as gravitational interactions with a third body. Observations of eccentricities and spin-orbit misalignments of hot Jupiter systems have been unable to differentiate between the two hypotheses.more » In the present work, we suggest that chemical depletions in hot Jupiter atmospheres might be able to constrain their migration mechanisms. We find that sub-solar carbon and oxygen abundances in Jovian-mass hot Jupiters around Sun-like stars are hard to explain by disk migration. Instead, such abundances are more readily explained by giant planets forming at large orbital separations, either by core accretion or gravitational instability, and migrating to close-in orbits via disk-free mechanisms involving dynamical encounters. Such planets also contain solar or super-solar C/O ratios. On the contrary, hot Jupiters with super-solar O and C abundances can be explained by a variety of formation-migration pathways which, however, lead to solar or sub-solar C/O ratios. Current estimates of low oxygen abundances in hot Jupiter atmospheres may be indicative of disk-free migration mechanisms. We discuss open questions in this area which future studies will need to investigate.« less

The source of 90-day oscillations at Wake Island

NASA Technical Reports Server (NTRS)

Mitchum, Gary T.

1995-01-01

Energetic 90-day oscillations of sea level have been intermittently observed at Wake Island in the western tropical Pacific during the past 2 decades. The oscillations tend to occur about 1.5 years after El Nino-Southern Oscillation events, to have amplitudes of 10-15 cm, and to persist for about 1 year. Sea surface heights from the Geosat altimeter are used to establish that these signals take the form of Rossby waves and have an energy source near the Big Island of Hawaii, which lies 40 deg of longitude to the east. Sea level and upper layer currents from an eddy-resolving numerical model are examined and suggest that the energy source is eddies generated off the Big Island of Hawaii. These eddies appear to be associated with westward currents that intermittently impinge on the island. Several alternate hypotheses are also discussed and rejected.

Aspects of the linguistic competence of deaf children.

PubMed

Wood, D

1984-02-01

In this paper the following three issues are considered in the light of recent research: Do severely/profoundly deaf children develop a grammar for English? Evidence is presented which suggests that they do and that this grammar displays a number of general characteristics some of which parallel the language of younger hearing children, others that do not. The limitations of this grammar will be discussed and hypotheses about the nature, origins and inevitability of such limitations explored. In what ways do the linguistic experiences of deaf children differ from that of hearing children? Some aspects of the deaf child's experience of language will be explored and their linguistic and psychological implications discussed. The relationships between current research findings on the linguistic development of the deaf and the possibility of improved educational methods will also be explored to consider the various different philosophies currently being debated in this field.

Rethinking Social Cognition in Light of Psychosis: Reciprocal Implications for Cognition and Psychopathology

PubMed Central

Bell, Vaughan; Mills, Kathryn L.; Modinos, Gemma; Wilkinson, Sam

2017-01-01

The positive symptoms of psychosis largely involve the experience of illusory social actors, and yet our current measures of social cognition, at best, only weakly predict their presence. We review evidence to suggest that the range of current approaches in social cognition is not sufficient to explain the fundamentally social nature of these experiences. We argue that social agent representation is an important organizing principle for understanding social cognition and that alterations in social agent representation may be a factor in the formation of delusions and hallucination in psychosis. We evaluate the feasibility of this approach in light of clinical and nonclinical studies, developmental research, cognitive anthropology, and comparative psychology. We conclude with recommendations for empirical testing of specific hypotheses and how studies of social cognition could more fully capture the extent of social reasoning and experience in both psychosis and more prosaic mental states. PMID:28533946

Can Scientifically Useful Hypotheses Be Tested with Correlations?

ERIC Educational Resources Information Center

Bentler, Peter M.

2007-01-01

Historically, interesting psychological theories have been phrased in terms of correlation coefficients, which are standardized covariances, and various statistics derived from them. Methodological practice over the last 40 years, however, has suggested it is necessary to transform such theories into hypotheses on covariances and statistics…

A Psychological Perspective of Teen Romances in Young Adult Literature.

ERIC Educational Resources Information Center

Dickson, Cheryl L.

2001-01-01

Suggests that just as violence on television is hypothesized to increase real-life violence, television romance can likely affect views of real-life romance. Hypothesizes that literature could undo television's mistakes and bridge the gap between real love and fantasy love. (SG)

Some crucial corona and prominence observations

NASA Technical Reports Server (NTRS)

Tandberg-Hanssen, E. A.

1986-01-01

A number of theories and hypotheses are currently being developed to explain the often complex behavior of corona and prominence plasmas. In order to test the theories and hypotheses certain crucial observations are necessary. Some of these observations are examined and a few conclusions are drawn. Corona mass balance, corona and prominence classifications, prominence formation and stability, and coronal mass ejection are dicussed.

Interpersonal trauma, attachment insecurity and anxiety in an inpatient psychiatric population.

PubMed

Wiltgen, Anika; Arbona, Consuelo; Frankel, Leslie; Frueh, B Christopher

2015-10-01

Current research suggests that interpersonal trauma has an impact on insecure attachment and anxiety. Some research further suggests that attachment may play a mediating role between traumatic events and psychopathology. The purpose of this study was to examine the relationship between the experience of interpersonal trauma, attachment anxiety, attachment avoidance and clinical anxiety severity among adult psychiatric inpatients who reported having experienced interpersonal trauma after the age of 16. It was hypothesized that attachment anxiety and attachment avoidance would mediate the relationship between interpersonal trauma and clinical anxiety level. This study used archival data on 414 adult psychiatric inpatients in a large city in the Southwest U.S. Results suggest that interpersonal trauma was correlated to attachment avoidance but not to attachment anxiety and that attachment avoidance partially mediated the relation of interpersonal trauma to anxiety. The attachment framework appositely explains how a negative model of other contributes to the relation between experiences of interpersonal trauma and anxiety in adulthood. Copyright © 2015 Elsevier Ltd. All rights reserved.

Testing Mediators of Reduced Drinking for Veterans in Alcohol Care Management.

PubMed

Moskal, Dezarie; Maisto, Stephen A; Possemato, Kyle; Lynch, Kevin G; Oslin, David W

2018-03-26

Alcohol Care Management (ACM) is a manualized treatment provided by behavioral health providers working in a primary care team aimed at increasing patients' treatment engagement and decreasing their alcohol use. Research has shown that ACM is effective in reducing alcohol consumption; however, the mechanisms of ACM are unknown. Therefore, the purpose of this study is to examine the mechanisms of change in ACM in the context of a randomized clinical trial evaluating the effectiveness of ACM. This study performed secondary data analysis of existing data from a larger study that involved a sample of U.S. veterans (N = 163) who met criteria for current alcohol dependence. Upon enrollment into the study, participants were randomized to receive either ACM or standard care. ACM was delivered in-person or by telephone within the primary care clinic and focused on the use of oral naltrexone and manualized psychosocial support. According to theory, we hypothesized several ACM treatment components that would mediate alcohol consumption outcomes: engagement in addiction treatment, reduced craving, and increased readiness to change. Parallel mediation models were performed by the PROCESS macro Model 4 in SPSS to test study hypotheses. The institutional review boards at each of the participating facilities approved all study procedures before data collection. As hypothesized, results showed that treatment engagement mediated the relation between treatment and both measures of alcohol consumption outcomes, the percentage of alcohol abstinent days, and the percentage of heavy drinking days. Neither craving nor readiness to change mediated the treatment effect on either alcohol consumption outcome. Findings suggest that ACM may be effective in changing drinking patterns partially due to an increase in treatment engagement. Future research may benefit from evaluating the specific factors that underlie increased treatment engagement. The current study provides evidence that alcohol use disorder interventions should aim to increase treatment engagement and reduce barriers to care.

Testing assumptions on prefrontal transcranial direct current stimulation: Comparison of electrode montages using multimodal fMRI.

PubMed

Wörsching, Jana; Padberg, Frank; Goerigk, Stephan; Heinz, Irmgard; Bauer, Christine; Plewnia, Christian; Hasan, Alkomiet; Ertl-Wagner, Birgit; Keeser, Daniel

2018-05-04

Transcranial direct current stimulation (tDCS) of the prefrontal cortex (PFC) has been widely applied in cognitive neurosciences and advocated as a therapeutic intervention, e.g. in major depressive disorder. Although several targets and protocols have been suggested, comparative studies of tDCS parameters, particularly electrode montages and their cortical targets, are still lacking. This study investigated a priori hypotheses on specific effects of prefrontal-tDCS montages by using multimodal functional magnetic resonance imaging (fMRI) in healthy participants. 28 healthy male participants underwent three common active-tDCS montages and sham tDCS in a pseudo-randomized order, comprising a total of 112 tDCS-fMRI sessions. Active tDCS was applied at 2 mA for 20 min. Before and after tDCS, a resting-state fMRI (RS fMRI) was recorded, followed by a task fMRI with a delayed-response working-memory (DWM) task for assessing cognitive control over emotionally negative or neutral distractors. After tDCS with a cathode-F3/anode-F4 montage, RS-fMRI connectivity decreased in a medial part of the left PFC. Also, after the same stimulation condition, regional brain activity during DWM retrieval decreased more in this area after negative than after neutral distraction, and responses to the DWM task were faster, independent of distractor type. The current study does not confirm our a priori hypotheses on direction and localization of polarity-dependent tDCS effects using common bipolar electrode montages over PFC regions, but it provides evidence for montage-specific effects on multimodal neurophysiological and behavioral outcome measures. Systematic research on the actual targets and the respective dose-response relationships of prefrontal tDCS is warranted. Copyright © 2018 Elsevier Inc. All rights reserved.

Debates—Hypothesis testing in hydrology: Introduction

NASA Astrophysics Data System (ADS)

Blöschl, Günter

2017-03-01

This paper introduces the papers in the "Debates—Hypothesis testing in hydrology" series. The four articles in the series discuss whether and how the process of testing hypotheses leads to progress in hydrology. Repeated experiments with controlled boundary conditions are rarely feasible in hydrology. Research is therefore not easily aligned with the classical scientific method of testing hypotheses. Hypotheses in hydrology are often enshrined in computer models which are tested against observed data. Testability may be limited due to model complexity and data uncertainty. All four articles suggest that hypothesis testing has contributed to progress in hydrology and is needed in the future. However, the procedure is usually not as systematic as the philosophy of science suggests. A greater emphasis on a creative reasoning process on the basis of clues and explorative analyses is therefore needed.

The influence of decadal scale climactic events on the transport of larvae.

NASA Astrophysics Data System (ADS)

Rasmuson, L. K.; Edwards, C. A.; Shanks, A.

2016-02-01

Understanding the processes that influence larval transport remains an important, yet difficult, task. This is especially true as more studies demonstrate that biological and physical oceanographic processes vary at long (e.g. decadal+) time scales. We used individual based biophysical models to study transport of Dungeness crab larvae (the most economically valuable fishery on the West Coast of the Continental United States) over a 10-year period; during both positive and negative phases of the Pacific decadal oscillation (PDO). A physical oceanographic model of the California current was developed using the Regional Ocean Modeling System with 1/30-degree resolution. Measured and modeled PDO indices were positively correlated. The biological model was implemented using the Lagrangian Transport Model, and modified to incorporate temperature dependent development and stage specific behaviors. Super individuals were used to scale production and incorporate mortality. Models were validated using time series statistics to compare measured and modeled daily recruitment. More larvae recruited, in both our measured and modeled time series, during negative PDOs. Our work suggests larvae exhibit a vertically migratory behavior too or almost too the bottom each day. During positive PDO years larvae were competent to settle earlier than negative PDO years, however, pelagic larval durations did not differ. The southern end of the population appears to be a sink population, which likely explains the decline in commercial catch. Ultimately, the population is much more demographically closed than previously thought. We hypothesize the stronger flow in the California current during negative PDO's enhances membership of larvae in the current. Further, migrating almost too the bottom causes larvae to enter the benthic boundary layer on the continental shelf and the California undercurrent on the continental slope, both, which decrease net alongshore advection. These factors result in a higher number of larvae closing their larval phase within the California current. We hypothesize Dungeness crabs have evolved to complete their larval phase within the oceanographic context of the California current and differences with the oceanography in the Alaska current may explain the difficulties in managing fisheries.

Whorfian effects on colour memory are not reliable.

PubMed

Wright, Oliver; Davies, Ian R L; Franklin, Anna

2015-01-01

The Whorfian hypothesis suggests that differences between languages cause differences in cognitive processes. Support for this idea comes from studies that find that patterns of colour memory errors made by speakers of different languages align with differences in colour lexicons. The current study provides a large-scale investigation of the relationship between colour language and colour memory, adopting a cross-linguistic and developmental approach. Colour memory on a delayed matching-to-sample (XAB) task was investigated in 2 language groups with differing colour lexicons, for 3 developmental stages and 2 regions of colour space. Analyses used a Bayesian technique to provide simultaneous assessment of two competing hypotheses (H1-Whorfian effect present, H0-Whorfian effect absent). Results of the analyses consistently favoured H0. The findings suggest that Whorfian effects on colour memory are not reliable and that the importance of such effects should not be overestimated.

Moral Enhancement Should Target Self-Interest and Cognitive Capacity.

PubMed

Ahlskog, Rafael

2017-01-01

Current suggestions for capacities that should be targeted for moral enhancement has centered on traits like empathy, fairness or aggression. The literature, however, lacks a proper model for understanding the interplay and complexity of moral capacities, which limits the practicability of proposed interventions. In this paper, I integrate some existing knowledge on the nature of human moral behavior and present a formal model of prosocial motivation. The model provides two important results regarding the most friction-free route to moral enhancement. First, we should consider decreasing self-interested motivation rather than increasing prosociality directly. Second, this should be complemented with cognitive enhancement. These suggestions are tested against existing and emerging evidence on cognitive capacity, mindfulness meditation and the effects of psychedelic drugs and are found to have sufficient grounding for further theoretical and empirical exploration. Furthermore, moral effects of the latter two are hypothesized to result from a diminished sense of self with subsequent reductions in self-interest.

Thinking of You: Nonconscious Pursuit of Interpersonal Goals Associated With Relationship Partners

PubMed Central

Fitzsimons, Gráinne M.; Bargh, John A.

2010-01-01

The mere psychological presence of relationship partners was hypothesized to trigger interpersonal goals that are then pursued nonconsciously. Qualitative data suggested that people tend to pursue different interpersonal goals within different types of relationships (e.g., mother, best friend, coworker). In several studies, priming participants’ relationship representations produced goal-directed behavior (achievement, helping, understanding) in line with the previously assessed goal content of those representations. These findings support the hypothesis that interpersonal goals are component features of relationship representations and that mere activation of those representations, even in the partner’s physical absence, causes the goals to become active and to guide behavior nonconsciously within the current situation. PMID:12518976

Isolated acquired factor VII deficiency: review of the literature.

PubMed

Mulliez, Sylvie M N; Devreese, Katrien M J

2016-04-01

Isolated acquired factor VII (FVII) deficiency is a rare haemorrhagic disorder. We report what is currently known about the pathogenesis, clinical features, diagnosis, treatment and prognosis of acquired FVII deficiency. We performed a literature search and included all articles published between 1980 and August 2015. Acquired FVII deficiency has been reported in 42 patients. There are well-established clinical diseases associated with acquired FVII deficiency, most notably infections, malignancy and haematological stem cell transplantation. The exact pathogenesis of the diseases is still unknown, but different pathophysiological hypotheses have been suggested. The clinical manifestation of acquired FVII deficiency varies greatly in severity; asymptomatic course as well as severe life-threatening bleeding diathesis and fatal bleedings have been described.

Conversion Disorder- Mind versus Body: A Review.

PubMed

Ali, Shahid; Jabeen, Shagufta; Pate, Rebecca J; Shahid, Marwah; Chinala, Sandhya; Nathani, Milankumar; Shah, Rida

2015-01-01

In this article, the authors accentuate the signs and symptoms of conversion disorder and the significance of clinical judgment and expertise in order to reach the right diagnosis. The authors review the literature and provide information on the etiology, prevalence, diagnostic criteria, and the treatment methods currently employed in the management of conversion disorder. Of note, the advancements of neuropsychology and brain imaging have led to emergence of a relatively sophisticated picture of the neuroscientific psychopathology of complex mental illnesses, including conversion disorder. The available evidence suggests new methods with which to test hypotheses about the neural circuits underlying conversion symptoms. In context of this, the authors also explore the neurobiological understanding of conversion disorder.

Conversion Disorder— Mind versus Body: A Review

PubMed Central

Jabeen, Shagufta; Pate, Rebecca J.; Shahid, Marwah; Chinala, Sandhya; Nathani, Milankumar; Shah, Rida

2015-01-01

In this article, the authors accentuate the signs and symptoms of conversion disorder and the significance of clinical judgment and expertise in order to reach the right diagnosis. The authors review the literature and provide information on the etiology, prevalence, diagnostic criteria, and the treatment methods currently employed in the management of conversion disorder. Of note, the advancements of neuropsychology and brain imaging have led to emergence of a relatively sophisticated picture of the neuroscientific psychopathology of complex mental illnesses, including conversion disorder. The available evidence suggests new methods with which to test hypotheses about the neural circuits underlying conversion symptoms. In context of this, the authors also explore the neurobiological understanding of conversion disorder. PMID:26155375

Association between exposure to antimicrobial household products and allergic symptoms.

PubMed

Hong, Soyoung; Kwon, Ho-Jang; Choi, Won-Jun; Lim, Wan Ryung; Kim, Jeonghoon; Kim, KyooSang

2014-01-01

Antimicrobial chemicals are used in a variety of household and personal care products. Exposure to antimicrobial household products has been hypothesized to lead to allergic diseases in children. We investigated antimicrobial household product exposure and allergic symptoms in Korean children. An antimicrobial exposure (AE) score was derived. To examine the symptoms of allergic diseases (current wheeze, current rhinitis, and current eczema) in the past 12 months, we used a questionnaire based on the core module of the International Study of Asthma and Allergies in Children. Complete data for the analysis were available for 25,805 of the 35,590 (72.5%) children. The prevalence of current allergic diseases was as follows: wheeze, 5.6%; allergic rhinitis, 32.6%; and eczema, 17.7%. The mean (standard deviation) AE score was 14.3 (9.3) (range: 0-40). Compared with subjects with a low AE score (reference), subjects with a high AE score (fourth quartile) were more likely to have symptoms of wheezing and allergic rhinitis (adjusted odds ratio [aOR] for wheezing 1.24, 95% confidence interval [CI], 1.05-1.45, p for trend=0.24; aOR for allergic rhinitis 1.30, 95% CI, 1.20-1.40, p<0.01). These findings suggest that frequent use of antimicrobial household products was associated with current wheeze and current allergic rhinitis.

Toward an Integration of Deep Learning and Neuroscience

PubMed Central

Marblestone, Adam H.; Wayne, Greg; Kording, Konrad P.

2016-01-01

Neuroscience has focused on the detailed implementation of computation, studying neural codes, dynamics and circuits. In machine learning, however, artificial neural networks tend to eschew precisely designed codes, dynamics or circuits in favor of brute force optimization of a cost function, often using simple and relatively uniform initial architectures. Two recent developments have emerged within machine learning that create an opportunity to connect these seemingly divergent perspectives. First, structured architectures are used, including dedicated systems for attention, recursion and various forms of short- and long-term memory storage. Second, cost functions and training procedures have become more complex and are varied across layers and over time. Here we think about the brain in terms of these ideas. We hypothesize that (1) the brain optimizes cost functions, (2) the cost functions are diverse and differ across brain locations and over development, and (3) optimization operates within a pre-structured architecture matched to the computational problems posed by behavior. In support of these hypotheses, we argue that a range of implementations of credit assignment through multiple layers of neurons are compatible with our current knowledge of neural circuitry, and that the brain's specialized systems can be interpreted as enabling efficient optimization for specific problem classes. Such a heterogeneously optimized system, enabled by a series of interacting cost functions, serves to make learning data-efficient and precisely targeted to the needs of the organism. We suggest directions by which neuroscience could seek to refine and test these hypotheses. PMID:27683554

Reasons for Quitting Smoking Prior to a Self-Quit Attempt among Smokers with and without Posttraumatic Stress Disorder or Other Anxiety/Mood Psychopathology

PubMed Central

Marshall, Erin C.; Vujanovic, Anka A.; Kutz, Amanda; Gibson, Laura; Leyro, Teresa; Zvolensky, Michael J.

2009-01-01

The present investigation examined intrinsic and extrinsic reasons for quitting among daily cigarette smokers with posttraumatic stress disorder (PTSD) as compared to clinical daily smokers with other anxiety and mood disorders (AM) and daily smokers with no current axis I psychopathology (C) prior to a self-guided quit attempt. It was hypothesized that (1) the PTSD group would report greater intrinsic (i.e., self-control and health concerns) reasons for quitting smoking, and (2) among those with PTSD, anxiety sensitivity (fear of anxiety; AS) would predict greater intrinsic reasons for quitting smoking. Participants were 143 (58.7% female; Mage = 29.66 years, SD = 11.88) daily cigarette smokers. Partially consistent with prediction, the PTSD group reported significantly greater self-control intrinsic reasons for quitting, but not health concern intrinsic reasons, than the C group (p <.01). The PTSD group also reported greater immediate reinforcement extrinsic reasons for quitting than the C group (p <.05). The PTSD and AM groups did not significantly differ on any reasons for quitting. Also partially consistent with hypotheses, higher levels of anxiety sensitivity in daily smokers with axis I psychopathology (both PTSD and AM groups) significantly predicted greater self-control intrinsic reasons for quitting. AS did not significantly predict immediate reinforcement extrinsic reasons for quitting. The current findings suggest that individuals with PTSD and other psychopathology may have unique motivations for quitting smoking that could be usefully explored within smoking cessation treatment programs. PMID:19444735

Reasons for quitting smoking prior to a self-quit attempt among smokers with and without posttraumatic stress disorder or other anxiety/mood psychopathology.

PubMed

Marshall, Erin C; Vujanovic, Anka A; Kutz, Amanda; Gibson, Laura; Leyro, Teresa; Zvolensky, Michael J

2009-01-01

The present investigation examined intrinsic and extrinsic reasons for quitting among daily cigarette smokers with posttraumatic stress disorder (PTSD) as compared to clinical daily smokers with other anxiety and mood disorders (AM) and daily smokers with no current Axis I psychopathology (C) prior to a self-guided quit attempt. It was hypothesized that (1) the PTSD group would report greater intrinsic (ie, self-control and health concerns) reasons for quitting smoking, and (2) among those with PTSD, anxiety sensitivity (fear of anxiety; AS) would predict greater intrinsic reasons for quitting smoking. Participants were 143 (58.7% female; M(age) = 29.66 years, SD = 11.88) daily cigarette smokers. Partially consistent with prediction, the PTSD group reported significantly greater self-control intrinsic reasons for quitting, but not health concern intrinsic reasons, than the C group (p < .01). The PTSD group also reported greater immediate reinforcement extrinsic reasons for quitting than the C group (p < .05). The PTSD and AM groups did not significantly differ on any reasons for quitting. Also partially consistent with hypotheses, higher levels of anxiety sensitivity in daily smokers with Axis I psychopathology (both PTSD and AM groups) significantly predicted greater self-control intrinsic reasons for quitting. AS did not significantly predict immediate reinforcement extrinsic reasons for quitting. The current findings suggest that individuals with PTSD and other psychopathology may have unique motivations for quitting smoking that could be usefully explored within smoking cessation treatment programs.

The neurobiological basis of human aggression: A review on genetic and epigenetic mechanisms.

PubMed

Waltes, Regina; Chiocchetti, Andreas G; Freitag, Christine M

2016-07-01

Aggression is an evolutionary conserved behavior present in most species including humans. Inadequate aggression can lead to long-term detrimental personal and societal effects. Here, we differentiate between proactive and reactive forms of aggression and review the genetic determinants of it. Heritability estimates of aggression in general vary between studies due to differing assessment instruments for aggressive behavior (AB) as well as age and gender of study participants. In addition, especially non-shared environmental factors shape AB. Current hypotheses suggest that environmental effects such as early life stress or chronic psychosocial risk factors (e.g., maltreatment) and variation in genes related to neuroendocrine, dopaminergic as well as serotonergic systems increase the risk to develop AB. In this review, we summarize the current knowledge of the genetics of human aggression based on twin studies, genetic association studies, animal models, and epigenetic analyses with the aim to differentiate between mechanisms associated with proactive or reactive aggression. We hypothesize that from a genetic perspective, the aminergic systems are likely to regulate both reactive and proactive aggression, whereas the endocrine pathways seem to be more involved in regulation of reactive aggression through modulation of impulsivity. Epigenetic studies on aggression have associated non-genetic risk factors with modifications of the stress response and the immune system. Finally, we point to the urgent need for further genome-wide analyses and the integration of genetic and epigenetic information to understand individual differences in reactive and proactive AB. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

Mediators of weight loss in a family-based intervention presented over the internet.

PubMed

White, Marney A; Martin, Pamela D; Newton, Robert L; Walden, Heather M; York-Crowe, Emily E; Gordon, Stewart T; Ryan, Donna H; Williamson, Donald A

2004-07-01

To assess the process variables involved in a weight loss program for African-American adolescent girls. Several process variables have been identified as affecting success in in vivo weight loss programs for adults and children, including program adherence, self-efficacy, and social support. The current study sought to broaden the understanding of these process variables as they pertain to an intervention program that is presented using the Internet. It was hypothesized that variables such as program adherence, dietary self-efficacy, psychological factors, and family environment factors would mediate the effect of the experimental condition on weight loss. Participants were 57 adolescent African-American girls who joined the program with one obese parent; family pairs were randomized to either a behavioral or control condition in an Internet-based weight loss program. Outcome data (weight loss) are reported for the first 6 months of the intervention. Results partially supported the hypotheses. For weight loss among adolescents, parent variables pertaining to life and family satisfaction were the strongest mediating variables. For parental weight loss, changes in dietary practices over the course of 6 months were the strongest mediators. The identification of factors that enhance or impede weight loss for adolescents is an important step in improving weight loss programs for this group. The current findings suggest that family/parental variables exert a strong influence on weight loss efforts for adolescents and should be considered in developing future programs. Copyright 2004 NAASO

Seismic imaging of a mid-lithospheric discontinuity beneath Ontong Java Plateau

NASA Astrophysics Data System (ADS)

Tharimena, Saikiran; Rychert, Catherine A.; Harmon, Nicholas

2016-09-01

Ontong Java Plateau (OJP) is a huge, completely submerged volcanic edifice that is hypothesized to have formed during large plume melting events ∼90 and 120 My ago. It is currently resisting subduction into the North Solomon trench. The size and buoyancy of the plateau along with its history of plume melting and current interaction with a subduction zone are all similar to the characteristics and hypothesized mechanisms of continent formation. However, the plateau is remote, and enigmatic, and its proto-continent potential is debated. We use SS precursors to image seismic discontinuity structure beneath Ontong Java Plateau. We image a velocity increase with depth at 28 ± 4 km consistent with the Moho. In addition, we image velocity decreases at 80 ± 5 km and 282 ± 7 km depth. Discontinuities at 60-100 km depth are frequently observed both beneath the oceans and the continents. However, the discontinuity at 282 km is anomalous in comparison to surrounding oceanic regions; in the context of previous results it may suggest a thick viscous root beneath OJP. If such a root exists, then the discontinuity at 80 km bears some similarity to the mid-lithospheric discontinuities (MLDs) observed beneath continents. One possibility is that plume melting events, similar to that which formed OJP, may cause discontinuities in the MLD depth range. Plume-plate interaction could be a mechanism for MLD formation in some continents in the Archean prior to the onset of subduction.

Brain size and thermoregulation during the evolution of the genus Homo.

PubMed

Naya, Daniel E; Naya, Hugo; Lessa, Enrique P

2016-01-01

Several hypotheses have been proposed to explain the evolution of an energetically costly brain in the genus Homo. Some of these hypotheses are based on the correlation between climatic factors and brain size recorded for this genus during the last millions of years. In this study, we propose a complementary climatic hypothesis that is based on the mechanistic connection between temperature, thermoregulation, and size of internal organs in endothermic species. We hypothesized that global cooling during the last 3.2 my may have imposed an increased energy expenditure for thermoregulation, which in the case of hominids could represent a driver for the evolution of an expanded brain, or at least, it could imply the relaxation of a negative selection pressure acting upon this costly organ. To test this idea, here we (1) assess variation in the energetic costs of thermoregulation and brain maintenance for the last 3.2 my, and (2) evaluate the relationship between Earth temperature and brain maintenance cost for the same period, taking into account the effects of body mass and fossil age. We found that: (1) the energetic cost associated with brain enlargement represents an important fraction (between 47.5% and 82.5%) of the increase in energy needed for thermoregulation; (2) fossil age is a better predictor of brain maintenance cost than Earth temperature, suggesting that (at least) another factor correlated with time was more relevant than ambient temperature in brain size evolution; and (3) there is a significant negative correlation between the energetic cost of brain and Earth temperature, even after accounting for the effect of body mass and fossil age. Thus, our results expand the current energetic framework for the study of brain size evolution in our lineage by suggesting that a fall in Earth temperature during the last millions of years may have facilitated brain enlargement. Copyright © 2015 Elsevier Inc. All rights reserved.

Fault Tree Based Diagnosis with Optimal Test Sequencing for Field Service Engineers

NASA Technical Reports Server (NTRS)

Iverson, David L.; George, Laurence L.; Patterson-Hine, F. A.; Lum, Henry, Jr. (Technical Monitor)

1994-01-01

When field service engineers go to customer sites to service equipment, they want to diagnose and repair failures quickly and cost effectively. Symptoms exhibited by failed equipment frequently suggest several possible causes which require different approaches to diagnosis. This can lead the engineer to follow several fruitless paths in the diagnostic process before they find the actual failure. To assist in this situation, we have developed the Fault Tree Diagnosis and Optimal Test Sequence (FTDOTS) software system that performs automated diagnosis and ranks diagnostic hypotheses based on failure probability and the time or cost required to isolate and repair each failure. FTDOTS first finds a set of possible failures that explain exhibited symptoms by using a fault tree reliability model as a diagnostic knowledge to rank the hypothesized failures based on how likely they are and how long it would take or how much it would cost to isolate and repair them. This ordering suggests an optimal sequence for the field service engineer to investigate the hypothesized failures in order to minimize the time or cost required to accomplish the repair task. Previously, field service personnel would arrive at the customer site and choose which components to investigate based on past experience and service manuals. Using FTDOTS running on a portable computer, they can now enter a set of symptoms and get a list of possible failures ordered in an optimal test sequence to help them in their decisions. If facilities are available, the field engineer can connect the portable computer to the malfunctioning device for automated data gathering. FTDOTS is currently being applied to field service of medical test equipment. The techniques are flexible enough to use for many different types of devices. If a fault tree model of the equipment and information about component failure probabilities and isolation times or costs are available, a diagnostic knowledge base for that device can be developed easily.

Motivation, self-determination, and long-term weight control

PubMed Central

2012-01-01

This article explores the topics of motivation and self-regulation in the context of weight management and related behaviors. We focus on the role of a qualitative approach to address motivation - not only considering the level but also type of motivation - in weight control and related behaviors. We critically discuss the operationalization of motivation in current weight control programs, present a complementary approach to understanding motivation based on self-determination theory, and review empirical findings from weight control studies that have used self-determination theory measures and assessed their association with weight outcomes. Weight loss studies which used Motivational Interviewing (MI) are also reviewed, considering MI's focus on enhancing internal motivation. We hypothesize that current weight control interventions may have been less successful with weight maintenance in part due to their relative disregard of qualitative dimensions of motivation, such as level of perceived autonomy, often resulting in a motivational disconnect between weight loss and weight-related behaviors. We suggest that if individuals fully endorse weight loss-related behavioral goals and feel not just competent but also autonomous about reaching them, as suggested by self-determination theory, their efforts are more likely to result in long-lasting behavior change. PMID:22385818

Motivation, self-determination, and long-term weight control.

PubMed

Teixeira, Pedro J; Silva, Marlene N; Mata, Jutta; Palmeira, António L; Markland, David

2012-03-02

This article explores the topics of motivation and self-regulation in the context of weight management and related behaviors. We focus on the role of a qualitative approach to address motivation--not only considering the level but also type of motivation--in weight control and related behaviors. We critically discuss the operationalization of motivation in current weight control programs, present a complementary approach to understanding motivation based on self-determination theory, and review empirical findings from weight control studies that have used self-determination theory measures and assessed their association with weight outcomes. Weight loss studies which used Motivational Interviewing (MI) are also reviewed, considering MI's focus on enhancing internal motivation. We hypothesize that current weight control interventions may have been less successful with weight maintenance in part due to their relative disregard of qualitative dimensions of motivation, such as level of perceived autonomy, often resulting in a motivational disconnect between weight loss and weight-related behaviors. We suggest that if individuals fully endorse weight loss-related behavioral goals and feel not just competent but also autonomous about reaching them, as suggested by self-determination theory, their efforts are more likely to result in long-lasting behavior change.

The Emergence of Knowledge and How it Supports the Memory for Novel Related Information.

PubMed

Sommer, Tobias

2017-03-01

Current theories suggest that memories for novel information and events, over time and with repeated retrieval, lose the association to their initial learning context. They are consolidated into a more stable form and transformed into semantic knowledge, that is, semanticized. Novel, related information can then be rapidly integrated into such knowledge, leading to superior memory. We tested these hypotheses in a longitudinal, 302-day, human functional magnetic resonance imaging study in which participants first overlearned and consolidated associative structures. This phase was associated with a shift from hippocampal- to ventrolateral prefrontal cortex (vlPFC)-mediated retrieval, consistent with semanticization. Next, participants encoded novel, related information whose encoding into the already acquired knowledge was orchestrated by the ventromedial prefrontal cortex. Novel related information exhibited reduced forgetting compared with novel control information, which corresponded to a faster shift from hippocampal- to vlPFC-mediated retrieval. In sum, the current results suggest that memory for novel information can be enhanced by anchoring it to prior knowledge via acceleration of the processes observed during semanticization. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Rational Variability in Children's Causal Inferences: The Sampling Hypothesis

ERIC Educational Resources Information Center

Denison, Stephanie; Bonawitz, Elizabeth; Gopnik, Alison; Griffiths, Thomas L.

2013-01-01

We present a proposal--"The Sampling Hypothesis"--suggesting that the variability in young children's responses may be part of a rational strategy for inductive inference. In particular, we argue that young learners may be randomly sampling from the set of possible hypotheses that explain the observed data, producing different hypotheses with…

A Systematic Review of Carrion Eaters' Adaptations to Avoid Sickness.

PubMed

Blumstein, Daniel T; Rangchi, Tiana N; Briggs, Tiandra; De Andrade, Fabrine Souza; Natterson-Horowitz, Barbara

2017-07-01

Species that scavenge on dead animals are exposed to enhanced disease risks. Eight hypotheses have been suggested to explain how scavengers avoid becoming sick from their diet. We conducted a systematic review of the literature and found correlative support for four of the eight hypotheses but limited evidence of systematic studies of the hypotheses. We found no support that using urine to sterilize carcasses, having bald heads, eating rapidly, or food-washing behavior reduced disease risk in carrion eaters. With the exception of food washing, none of these hypotheses have been properly evaluated as an adaptation to avoid sickness from carrion. There is some support for having a specialized microbiome, having enhanced immunologic defenses, avoiding rotten food, and maintaining a low gastric pH to eliminate pathogens. Specialized immunologic defenses and having a low pH have the most support, but the diversity of mechanisms suggests that there is a great opportunity for even more detailed study. Increased knowledge in these mechanisms may provide biomimetic insights to help combat foodborne illnesses and enhance health.

Logical positivism as a tool to analyse the problem of chemistry's lack of relevance in secondary school chemical education

NASA Astrophysics Data System (ADS)

van Aalsvoort, Joke

2004-09-01

Secondary school chemical education has a problem: namely, the seeming irrelevance to the pupils of chemistry. Chemical education prepares pupils for participation in society. Therefore, it must imply a model of society, of chemistry, and of the relation between them. In this article it is hypothesized that logical positivism currently offers this model. Logical positivism is a philosophy of science that creates a divide between science and society. It is therefore further hypothesized that the adoption of logical positivism causes chemistry's lack of relevance in chemical education. Both hypotheses could be confirmed by an analysis of a grade nine course.

Current Perspectives on the Cerebellum and Reading Development.

PubMed

Alvarez, Travis A; Fiez, Julie A

2018-05-03

The dominant neural models of typical and atypical reading focus on the cerebral cortex. However, Nicolson et al. (2001) proposed a model, the cerebellar deficit hypothesis, in which the cerebellum plays an important role in reading. To evaluate the evidence in support of this model, we qualitatively review the current literature and employ meta-analytic tools examining patterns of functional connectivity between the cerebellum and the cerebral reading network. We find evidence for a phonological circuit with connectivity between the cerebellum and a dorsal fronto-parietal pathway, and a semantic circuit with cerebellar connectivity to a ventral fronto-temporal pathway. Furthermore, both cerebral pathways have functional connections with the mid-fusiform gyrus, a region implicated in orthographic processing. Consideration of these circuits within the context of the current literature suggests the cerebellum is positioned to influence both phonological and word-based decoding procedures for recognizing unfamiliar printed words. Overall, multiple lines of research provide support for the cerebellar deficit hypothesis, while also highlighting the need for further research to test mechanistic hypotheses. Copyright © 2018. Published by Elsevier Ltd.

Did southern Western Ghats of peninsular India serve as refugia for its endemic biota during the Cretaceous volcanism?

PubMed Central

Joshi, Jahnavi; Karanth, Praveen

2013-01-01

The Western Ghats (WG) of south India, a global biodiversity hotspot, has experienced complex geological history being part of Gondwana landmass and encountered extensive volcanic activity at the end of Cretaceous epoch. It also has a climatically and topographically heterogeneous landscape. Thus, the WG offer a unique setting to explore the influence of ecological and geological processes on the current diversity and distribution of its biota. To this end, three explicit biogeographical scenarios were hypothesized to evaluate the distribution and diversification of wet evergreen species of the WG – (1) southern WG was a refuge for the wet evergreen species during the Cretaceous volcanism, (2) phylogenetic breaks in the species phylogeny would correspond to geographic breaks (i.e., the Palghat gap) in the WG, and (3) species from each of the biogeographic subdivisions within the WG would form distinct clades. These hypotheses were tested on the centipede genus Digitipes from the WG which is known to be an ancient, endemic, and monophyletic group. The Digitipes molecular phylogeny was subjected to divergence date estimation using Bayesian approach, and ancestral areas were reconstructed using parsimony approach for each node in the phylogeny. Ancestral-area reconstruction suggested 13 independent dispersal events to explain the current distribution of the Digitipes species in the WG. Among these 13 dispersals, two dispersal events were at higher level in the Digitipes phylogeny and were from the southern WG to the central and northern WG independently in the Early Paleocene, after the Cretaceous Volcanism. The remaining 11 dispersal events explained the species’ range expansions of which nine dispersals were from the southern WG to other biogeographic subdivisions in the Eocene-Miocene in the post-volcanic periods where species-level diversifications occurred. Taken together, these results suggest that southern WG might have served as a refuge for Digitipes species during Cretaceous volcanism. PMID:24223267

Investigating melting induced mantle heterogeneities in plate driven mantle convection models

NASA Astrophysics Data System (ADS)

Price, M.; Davies, H.; Panton, J.

2017-12-01

Observations from geochemistry and seismology continue to suggest a range of complex heterogeneity in Earth's mantle. In the deep mantle, two large low velocity provinces (LLVPs) have been regularly observed in seismic studies, with their longevity, composition and density compared to the surrounding mantle debated. The cause of these observed LLVPs is equally uncertain, with previous studies advocating either thermal or thermo-chemical causes. There is also evidence that these structures could provide chemically distinct reservoirs within the mantle, with recent studies also suggesting there may be additional reservoirs in the mantle, such as bridgmanite-enriched ancient mantle structures (BEAMS). One way to test these hypotheses is using computational models of the mantle, with models that capture the full 3D system being both complex and computationally expensive. Here we present results from our global mantle model TERRA. Using our model, we can track compositional variations in the convecting mantle that are generated by self-consistent, evolving melting zones. Alongside the melting, we track trace elements and other volatiles which can be partitioned during melting events, and expelled and recycled at the surface. Utilising plate reconstruction models as a boundary condition, the models generate the tectonic features observed at Earth's surface, while also organising the lower mantle into recognisable degree-two structures. This results in our models generating basaltic `oceanic' crusts which are then brought into the mantle at tectonic boundaries, providing additional chemical heterogeneity in the mantle volume. Finally, by utilising thermodynamic lookup tables to convert the final outputs from the model to seismic structures, together with resolution filters for global tomography models, we are able to make direct comparisons between our results and observations. By varying the parameters of the model, we investigate a range of current hypotheses for heterogeneity in the mantle. Our work attempts to reconcile the many proposed current ideas for the deep mantle, giving additional insight from modelling on the latest observations from other Deep Earth disciplines.

Hyoscine butylbromide potently blocks human nicotinic acetylcholine receptors in SH-SY5Y cells.

PubMed

Weiser, Thomas; Just, Stefan

2009-02-06

Hyoscine butylbromide (HBB; tradenames: Buscopan/Buscapina is an antispasmodic drug for the treatment of abdominal pain associated with gastrointestinal cramping. As a hyoscine derivative, this compound competitively inhibits muscarinic acetylcholine (ACh) receptors on smooth muscle cells in the gastrointestinal tract. Preliminary investigations suggested that it might also inhibit nicotinic ACh receptors. This study investigated the effect of HBB on nicotinic ACh receptor-mediated membrane currents in SH-SY5Y cells. ACh and nicotine application-induced comparable membrane currents with EC(50) values of 25.9+/-0.6 and 40.1+/-0.4microM, respectively. When coapplied with 100microM ACh, HBB concentration-dependently suppressed currents with an IC(50) value of 0.19+/-0.04microM, and was approximately seven-times more potent than the ganglionic blocker, hexamethonium (IC(50)=1.3+/-0.3microM). Increasing the agonist concentration to 5mM did not affect the amount of block by HBB, which suggests a non-competitive mode of action. These functional in vitro data demonstrate for the first time that HBB blocks neuronal nicotinic ACh receptors in the same concentration range as it inhibits muscarinic ACh receptors. If one hypothesizes that HBB might also affect nicotinic receptors in autonomic neurons in vivo (e. g. in the enteric nervous system), this effect could contribute to its spasmolytic activity.

Early nutrition programming of long-term health.

PubMed

Koletzko, Berthold; Brands, Brigitte; Poston, Lucilla; Godfrey, Keith; Demmelmair, Hans

2012-08-01

Increasing evidence from the EU Project EARNEST and many other investigators demonstrates that early nutrition and lifestyle have long-term effects on later health and the risk of common non-communicable diseases (known as 'developmental programming'). Because of the increasing public health importance and the transgenerational nature of the problem, obesity and associated disorders are the focus of the new EU funded project 'EarlyNutrition'. Currently, three key hypotheses have been defined: the fuel mediated 'in utero' hypothesis suggests that intrauterine exposure to an excess of fuels, most notably glucose, causes permanent changes of the fetus that lead to obesity in postnatal life; the accelerated postnatal weight gain hypothesis proposes an association between rapid weight gain in infancy and an increased risk of later obesity and adverse outcomes; and the mismatch hypothesis suggests that experiencing a developmental 'mismatch' between a sub-optimal perinatal and an obesogenic childhood environment is related to a particular predisposition to obesity and corresponding co-morbidities. Using existing cohort studies, ongoing and novel intervention studies and a basic science programme to investigate those key hypotheses, project EarlyNutrition will provide the scientific foundations for evidence-based recommendations for optimal nutrition considering long-term health outcomes, with a focus on obesity and related disorders. Scientific and technical expertise in placental biology, epigenetics and metabolomics will provide understanding at the cellular and molecular level of the relationships between early life nutritional status and the risk of later adiposity. This will help refine strategies for intervention in early life to prevent obesity.

Measuring Individual Differences in the Perfect Automation Schema.

PubMed

Merritt, Stephanie M; Unnerstall, Jennifer L; Lee, Deborah; Huber, Kelli

2015-08-01

A self-report measure of the perfect automation schema (PAS) is developed and tested. Researchers have hypothesized that the extent to which users possess a PAS is associated with greater decreases in trust after users encounter automation errors. However, no measure of the PAS currently exists. We developed a self-report measure assessing two proposed PAS factors: high expectations and all-or-none thinking about automation performance. In two studies, participants responded to our PAS measure, interacted with imperfect automated aids, and reported trust. Each of the two PAS measure factors demonstrated fit to the hypothesized factor structure and convergent and discriminant validity when compared with propensity to trust machines and trust in a specific aid. However, the high expectations and all-or-none thinking scales showed low intercorrelations and differential relationships with outcomes, suggesting that they might best be considered two separate constructs rather than two subfactors of the PAS. All-or-none thinking had significant associations with decreases in trust following aid errors, whereas high expectations did not. Results therefore suggest that the all-or-none thinking scale may best represent the PAS construct. Our PAS measure (specifically, the all-or-none thinking scale) significantly predicted the severe trust decreases thought to be associated with high PAS. Further, it demonstrated acceptable psychometric properties across two samples. This measure may be used in future work to assess levels of PAS in users of automated systems in either research or applied settings. © 2015, Human Factors and Ergonomics Society.

Novel patterns of historical isolation, dispersal, and secondary contact across Baja California in the Rosy Boa (Lichanura trivirgata).

PubMed

Wood, Dustin A; Fisher, Robert N; Reeder, Tod W

2008-02-01

Mitochondrial DNA (mtDNA) sequence variation was examined in 131 individuals of the Rosy Boa (Lichanura trivirgata) from across the species range in southwestern North America. Bayesian inference and nested clade phylogeographic analyses (NCPA) were used to estimate relationships and infer evolutionary processes. These patterns were evaluated as they relate to previously hypothesized vicariant events and new insights are provided into the biogeographic and evolutionary processes important in Baja California and surrounding North American deserts. Three major lineages (Lineages A, B, and C) are revealed with very little overlap. Lineage A and B are predominately separated along the Colorado River and are found primarily within California and Arizona (respectively), while Lineage C consists of disjunct groups distributed along the Baja California peninsula as well as south-central Arizona, southward along the coastal regions of Sonora, Mexico. Estimated divergence time points (using a Bayesian relaxed molecular clock) and geographic congruence with postulated vicariant events suggest early extensions of the Gulf of California and subsequent development of the Colorado River during the Late Miocene-Pliocene led to the formation of these mtDNA lineages. Our results also suggest that vicariance hypotheses alone do not fully explain patterns of genetic variation. Therefore, we highlight the importance of dispersal to explain these patterns and current distribution of populations. We also compare the mtDNA lineages with those based on morphological variation and evaluate their implications for taxonomy.

Novel patterns of historical isolation, dispersal, and secondary contact across Baja California in the Rosy Boa (Lichanura trivirgata)

USGS Publications Warehouse

Wood, D.A.; Fisher, R.N.; Reeder, T.W.

2008-01-01

Mitochondrial DNA (mtDNA) sequence variation was examined in 131 individuals of the Rosy Boa (Lichanura trivirgata) from across the species range in southwestern North America. Bayesian inference and nested clade phylogeographic analyses (NCPA) were used to estimate relationships and infer evolutionary processes. These patterns were evaluated as they relate to previously hypothesized vicariant events and new insights are provided into the biogeographic and evolutionary processes important in Baja California and surrounding North American deserts. Three major lineages (Lineages A, B, and C) are revealed with very little overlap. Lineage A and B are predominately separated along the Colorado River and are found primarily within California and Arizona (respectively), while Lineage C consists of disjunct groups distributed along the Baja California peninsula as well as south-central Arizona, southward along the coastal regions of Sonora, Mexico. Estimated divergence time points (using a Bayesian relaxed molecular clock) and geographic congruence with postulated vicariant events suggest early extensions of the Gulf of California and subsequent development of the Colorado River during the Late Miocene-Pliocene led to the formation of these mtDNA lineages. Our results also suggest that vicariance hypotheses alone do not fully explain patterns of genetic variation. Therefore, we highlight the importance of dispersal to explain these patterns and current distribution of populations. We also compare the mtDNA lineages with those based on morphological variation and evaluate their implications for taxonomy. ?? 2007 Elsevier Inc. All rights reserved.

Systemic racism moderates effects of provider racial biases on adherence to hypertension treatment for African Americans.

PubMed

Greer, Tawanda M; Brondolo, Elizabeth; Brown, Porschia

2014-01-01

The purpose of the current study was to examine perceived exposure to systemic racism as a moderator of the effects of perceived exposure to provider racial biases on treatment adherence and mistrust of health care for a sample of African American hypertensive patients. We hypothesized that patients who endorsed high levels of systemic racism would exhibit poor adherence to hypertension treatment and increased mistrust in health care in relation to perceptions of exposure to provider racial biases. The sample consisted of 100 African American patients who ranged in age from 24 to 82 years. All were diagnosed with hypertension and were recruited from an outpatient clinic located in the Southeastern region of the United States. Moderated regression analyses were performed to test the study hypotheses. Findings revealed a positive, significant main effect for perceived provider racial biases in predicting mistrust of care. This finding suggested that an increase in mistrust of health care was associated with increased perceptions of provider biases. In predicting treatment adherence, a significant interaction revealed that patients who endorsed low and moderate degrees of exposure to systemic racism displayed poor adherence to treatment in relation to greater perceptions of provider racial biases. The overall findings suggest that patients who perceive themselves as infrequently exposed to systemic racism possess the greatest risk for nonadherence to hypertension treatment in relation to increased perceptions of provider racial biases. Implications of the findings are discussed. 2014 APA, all rights reserved

[Contemporary cognitive theories about developmental dyscalculia].

PubMed

Castro-Cañizares, D; Estévez-Pérez, N; Reigosa-Crespo, V

To analyze the current theories describing the cognitive mechanisms underlying developmental dyscalculia. The four most researched hypotheses concerning the cognitive deficits related to developmental dyscalculia, as well as experimental evidences supporting or refusing them are presented. The first hypothesis states that developmental dyscalculia is consequence of domain general cognitive deficits. The second hypothesis suggests that it is due to a failure in the development of specialized brain systems dedicated to numerosity processing. The third hypothesis asserts the disorder is caused by a deficit in accessing quantity representation through numerical symbols. The last hypothesis states developmental dyscalculia appears as a consequence of impairments in a generalized magnitude system dedicated to the processing of continuous and discrete magnitudes. None of the hypotheses has been proven more plausible than the rest. Relevant issues rose by them need to be revisited and answered in the light of new experimental designs. In the last years the understanding of cognitive disorders involved in developmental dyscalculia has remarkably increased, but it is nonetheless insufficient. Additional research is required in order to achieve a comprehensive cognitive model of numerical processing development and its disorders. This will improve the diagnostic precision and the effectiveness of developmental dyscalculia intervention strategies.

Gratitude when it is needed most: social functions of gratitude in women with metastatic breast cancer.

PubMed

Algoe, Sara B; Stanton, Annette L

2012-02-01

Theory and evidence suggest that everyday positive emotions may be potent factors in resilience during periods of chronic stress, yet the body of evidence is scant. Even less research focuses on the adaptive functions of specific positive emotions in this critical context. In the current research, 54 women with metastatic breast cancer provided information about their emotional responses to benefits received to test hypotheses regarding the social functions of gratitude. One set of analyses provide support for the hypothesized role of ego-transcendence in feeling gratitude upon receipt of a benefit from another person. As predicted, in a second set of analyses, grateful responding to received benefits predicted an increase in perceived social support over three months only for women low in ambivalence over emotional expression. These findings add to evidence regarding the social causes and consequences of gratitude, supporting a view of gratitude as an other-focused positive emotion that functions to promote high-quality relationships. Discussion focuses on the chronically stressful context as an important testing ground for theory on gratitude and other positive emotions. PsycINFO Database Record (c) 2012 APA, all rights reserved

Contrasting phylogeographic patterns in Sphagnum fimbriatum and Sphagnum squarrosum (Bryophyta, Sphagnopsida) in Europe.

PubMed

Szövényi, Péter; Hock, Zsófia; Urmi, Edwin; Schneller, Jakob J

2006-01-01

The chloroplast phylogeography of two peat mosses (Sphagnum fimbriatum and Sphagnum squarrosum) with similar distributions but different life history characteristics was investigated in Europe. Our main aim was to test whether similar distributions reflect similar phylogeographic and phylodemographic processes. Accessions covering the European distributions of the species were collected and approx. 2000 bp of the chloroplast genome of each species was sequenced. Maximum parsimony, statistical parsimony and phylodemographic analyses were used to address the question of whether these species with similar distributions show evidence of similar phylogeographic and phylodemographic processes. The chloroplast haplotypes of the currently spreading species S. fimbriatum showed strong geographic structure, whereas those of S. squarrosum, which has stable historical population sizes, showed only very weak geographic affinity and were widely distributed. We hypothesize that S. fimbriatum survived the last glaciations along the Atlantic coast of Europe, whereas S. squarrosum had numerous, scattered refugia in Europe. The dominance of one haplotype of S. fimbriatum across almost all of Europe suggests rapid colonization after the last glacial maximum. We hypothesize that high colonizing ability is an inherent characteristic of the species and its recent expansion in Europe is a response to climate change.

Population growth as a driver of initial domestication in Eastern North America

PubMed Central

Codding, Brian F.

2016-01-01

The transition to agriculture is one of the most significant events in human prehistory; yet, explaining why people initially domesticated plants and animals remains a contentious research problem in archaeology. Two competing hypotheses dominate current debates. The first draws on niche construction theory to emphasize how intentional management of wild resources should lead to domestication regardless of Malthusian population–resource imbalances. The second relies on models from behavioural ecology (BE) to highlight how individuals should only exert selective pressure on wild resources during times of population–resource imbalance. We examine these hypotheses to explain the domestication event which occurred in Eastern North America approximately 5000 years ago. Using radiocarbon date density and site counts as proxies for human population, we find that populations increased significantly in the 1000 years prior to initial domestication. We therefore suggest that high populations prior to 5000 cal BP may have experienced competition for and possibly overexploitation of resources, altering the selective pressures on wild plants thereby producing domesticates. These findings support the BE hypothesis of domestication occurring in the context of population–resource imbalances. Such deficits, driven either by increased populations or decreased resource abundance, are predicted to characterize domestication events elsewhere. PMID:27853610

School burnout and heart rate variability: risk of cardiovascular disease and hypertension in young adult females.

PubMed

May, Ross W; Seibert, Gregory S; Sanchez-Gonzalez, Marcos A; Fincham, Frank D

2018-05-01

Emerging research documents the relationship between school burnout and some indicators of increased cardiovascular risk. Indicators of cardiovascular functioning assessed via ambulatory blood pressure and heart rate variability (HRV) have not been thoroughly explored in this research domain. Therefore, the current study examined relationships between school burnout and indicators of cardiac functioning via 24 h ambulatory blood pressure (BP) and electrocardiogram monitoring in a sample of young adult female undergraduates (N = 88). Two hypotheses were tested: (1) that independent of related negative affective symptomology (depression and anxiety), increased school burnout would be related to greater systolic and diastolic BP, higher low frequency (LF) HRV and lower very low frequency (VLF) HRV, and (2) that lower VLF would be related to greater school burnout independently of LF HRV. Hierarchical multiple regression analyzes showed that school burnout was significantly related to elevated ambulatory BP (systolic and diastolic) and HRV markers of increased cardiac sympathovagal tone. These findings support the hypotheses and suggest that school burnout might be implicated in the development of pre-hypertension or early cardiovascular disease. Study limitations and the need for future longitudinal research are discussed.

25 years of Eye Movement Desensitization and Reprocessing (EMDR): The EMDR therapy protocol, hypotheses of its mechanism of action and a systematic review of its efficacy in the treatment of post-traumatic stress disorder.

PubMed

Novo Navarro, Patricia; Landin-Romero, Ramón; Guardiola-Wanden-Berghe, Rocio; Moreno-Alcázar, Ana; Valiente-Gómez, Alicia; Lupo, Walter; García, Francisca; Fernández, Isabel; Pérez, Víctor; Amann, Benedikt L

Eye movement desensitization and reprocessing (EMDR) is a relatively new psychotherapy that has gradually gained popularity for the treatment of post-traumatic stress disorder. In the present work, the standardised EMDR protocol is introduced, along with current hypotheses of its mechanism of action, as well as a critical review of the available literature on its clinical effectiveness in adult post-traumatic stress disorder. A systematic review of the published literature was performed using PubMed and PsycINFO databases with the keywords «eye movement desensitization and reprocessing» and «post-traumatic stress disorder» and its abbreviations «EMDR» and «PTSD». Fifteen randomised controlled trials of good methodological quality were selected. These studies compared EMDR with unspecific interventions, waiting lists, or specific therapies. Overall, the results of these studies suggest that EMDR is a useful, evidence-based tool for the treatment of post-traumatic stress disorder, in line with recent recommendations from different international health organisations. Copyright © 2016 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

Eyes wide open: enhanced pupil dilation when selectively studying important information.

PubMed

Ariel, Robert; Castel, Alan D

2014-01-01

Remembering important information is imperative for efficient memory performance, but it is unclear how we encode important information. The current experiment evaluated two non-exclusive hypotheses for how learners selectively encode important information at the expense of less important information (differential resource allocation and information reduction). To evaluate these hypotheses, we measured changes in learners' pupil diameter and fixation durations while participants performed a selectivity task that involved studying lists consisting of words associated with different point values. Participants were instructed to maximize their score on a free recall task that they completed after studying each list. Participants' pupils dilated more when studying high-valued than low-valued words, and these changes were associated with better memory for high-valued words. However, participants fixated equally on words regardless of their value, which is inconsistent with the information reduction hypothesis. Participants also increased their memory selectivity across lists, but changes in pupil diameter and differences in fixations could not account for this increased selectivity. The results suggest that learners allocate attention differently to items as a function of their value, and that multiple processes and operations contribute to value-directed remembering.

Eyes Wide Open: Enhanced Pupil Dilation When Selectively Studying Important Information

PubMed Central

Ariel, Robert; Castel, Alan D.

2013-01-01

Remembering important information is imperative for efficient memory performance, but it is unclear how we encode important information. The current experiment evaluated two non-exclusive hypotheses for how learners selectively encode important information at the expense of less important information (differential resource allocation and information reduction). To evaluate these hypotheses, we measured changes in learners’ pupil diameter and fixation durations while participants performed a selectivity task that involved studying lists consisting of words associated with different point values. Participants were instructed to maximize their score on a free recall task that they completed after studying each list. Participants’ pupils dilated more when studying high-valued than low-valued words, and these changes were associated with better memory for high-valued words. However, participants fixated equally on words regardless of their value, which is inconsistent with the information reduction hypothesis. Participants also increased their memory selectivity across lists, but changes in pupil diameter and differences in fixations could not account for this increased selectivity. The results suggest that learners allocate attention differently to items as a function of their value, and that multiple processes and operations contribute to value-directed remembering. PMID:24162863

Warming shifts ‘worming': effects of experimental warming on invasive earthworms in northern North America

PubMed Central

Eisenhauer, Nico; Stefanski, Artur; Fisichelli, Nicholas A.; Rice, Karen; Rich, Roy; Reich, Peter B.

2014-01-01

Climate change causes species range shifts and potentially alters biological invasions. The invasion of European earthworm species across northern North America has severe impacts on native ecosystems. Given the long and cold winters in that region that to date supposedly have slowed earthworm invasion, future warming is hypothesized to accelerate earthworm invasions into yet non-invaded regions. Alternatively, warming-induced reductions in soil water content (SWC) can also decrease earthworm performance. We tested these hypotheses in a field warming experiment at two sites in Minnesota, USA by sampling earthworms in closed and open canopy in three temperature treatments in 2010 and 2012. Structural equation modeling revealed that detrimental warming effects on earthworm densities and biomass could indeed be partly explained by warming-induced reductions in SWC. The direction of warming effects depended on the current average SWC: warming had neutral to positive effects at high SWC, whereas the opposite was true at low SWC. Our results suggest that warming limits the invasion of earthworms in northern North America by causing less favorable soil abiotic conditions, unless warming is accompanied by increased and temporally even distributions of rainfall sufficient to offset greater water losses from higher evapotranspiration. PMID:25363633

Warming shifts 'worming': effects of experimental warming on invasive earthworms in northern North America.

PubMed

Eisenhauer, Nico; Stefanski, Artur; Fisichelli, Nicholas A; Rice, Karen; Rich, Roy; Reich, Peter B

2014-11-03

Climate change causes species range shifts and potentially alters biological invasions. The invasion of European earthworm species across northern North America has severe impacts on native ecosystems. Given the long and cold winters in that region that to date supposedly have slowed earthworm invasion, future warming is hypothesized to accelerate earthworm invasions into yet non-invaded regions. Alternatively, warming-induced reductions in soil water content (SWC) can also decrease earthworm performance. We tested these hypotheses in a field warming experiment at two sites in Minnesota, USA by sampling earthworms in closed and open canopy in three temperature treatments in 2010 and 2012. Structural equation modeling revealed that detrimental warming effects on earthworm densities and biomass could indeed be partly explained by warming-induced reductions in SWC. The direction of warming effects depended on the current average SWC: warming had neutral to positive effects at high SWC, whereas the opposite was true at low SWC. Our results suggest that warming limits the invasion of earthworms in northern North America by causing less favorable soil abiotic conditions, unless warming is accompanied by increased and temporally even distributions of rainfall sufficient to offset greater water losses from higher evapotranspiration.

A cognitive neuropsychological approach to the study of delusions in late-onset schizophrenia.

PubMed

Phillips, M L; Howard, R; David, A S

1997-09-01

Hypotheses to explain delusion formation include distorted perceptual processing of meaningful stimuli (e.g. faces), abnormal reasoning, or a combination of both. The study investigated these hypotheses using standardized neuropsychological tests. A three-patient case-study, compared with a small group (n = 8) of age-matched normal control subjects. Hospital in- and outpatients. Age-matched normal controls were from local residential homes. Three subjects with late-onset schizophrenia, two currently deluded and one in remission. Both deluded subjects had persecutory beliefs. One had a delusion of misidentification. All subjects were administered standardized neuropsychological tests of facial processing and tests of verbal reasoning. The test scores of the three patients were compared with published normal values and the age-matched control data. The tests demonstrated impaired matching of unfamiliar faces in deluded subjects, particularly in the subject with delusional misidentification. Increasing the emotional content of logical reasoning problems had a significant effect on the deluded subjects' reasoning but not that of the normal controls. The findings suggest impaired visual processing plus abnormal reasoning in deluded subjects. However, these impairments are relatively subtle given the severity of psychiatric disorder in the patients studied.

Anomalous Ion Heating, Intrinsic and Induced Rotation in the Pegasus Toroidal Experiment

NASA Astrophysics Data System (ADS)

Burke, M. G.; Barr, J. L.; Bongard, M. W.; Fonck, R. J.; Hinson, E. T.; Perry, J. M.; Redd, A. J.; Thome, K. E.

2014-10-01

Pegasus plasmas are initiated through either standard, MHD stable, inductive current drive or non-solenoidal local helicity injection (LHI) current drive with strong reconnection activity, providing a rich environment to study ion dynamics. During LHI discharges, a large amount of anomalous impurity ion heating has been observed, with Ti ~ 800 eV but Te < 100 eV. The ion heating is hypothesized to be a result of large-scale magnetic reconnection activity, as the amount of heating scales with increasing fluctuation amplitude of the dominant, edge localized, n = 1 MHD mode. Chordal Ti spatial profiles indicate centrally peaked temperatures, suggesting a region of good confinement near the plasma core surrounded by a stochastic region. LHI plasmas are observed to rotate, perhaps due to an inward radial current generated by the stochastization of the plasma edge by the injected current streams. H-mode plasmas are initiated using a combination of high-field side fueling and Ohmic current drive. This regime shows a significant increase in rotation shear compared to L-mode plasmas. In addition, these plasmas have been observed to rotate in the counter-Ip direction without any external momentum sources. The intrinsic rotation direction is consistent with predictions from the saturated Ohmic confinement regime. Work supported by US DOE Grant DE-FG02-96ER54375.

Why are we not evaluating multiple competing hypotheses in ecology and evolution?

PubMed Central

Avgar, Tal; Fryxell, John M.

2017-01-01

The use of multiple working hypotheses to gain strong inference is widely promoted as a means to enhance the effectiveness of scientific investigation. Only 21 of 100 randomly selected studies from the ecological and evolutionary literature tested more than one hypothesis and only eight tested more than two hypotheses. The surprising rarity of application of multiple working hypotheses suggests that this gap between theory and practice might reflect some fundamental issues. Here, we identify several intellectual and practical barriers that discourage us from using multiple hypotheses in our scientific investigation. While scientists have developed a number of ways to avoid biases, such as the use of double-blind controls, we suspect that few scientists are fully aware of the potential influence of cognitive bias on their decisions and they have not yet adopted many techniques available to overcome intellectual and practical barriers in order to improve scientific investigation. PMID:28280578

Geochemical Constraints on Core Formation in the Earth

NASA Technical Reports Server (NTRS)

Jones, John H.; Drake, Michael J.

1986-01-01

New experimental data on the partitioning of siderophile and chalcophile elements among metallic and silicate phases may be used to constrain hypotheses of core formation in the Earth. Three current hypotheses can explain gross features of mantle geochemistry, but none predicts siderophile and chalcophile element abundances to within a factor of two of observed values. Either our understanding of metal-silicate interactions and/or our understanding of the early Earth requires revision.

Interrogative Suggestibility among Adolescent Boys and Its Relationship with Intelligence, Memory, and Cognitive Set.

ERIC Educational Resources Information Center

Singh, Krishna K.; Gudjonsson, Gisli H.

1992-01-01

Investigated hypotheses generated by Gudjonsson and Clark model of interrogative suggestibility. Adolescent boys (n=40) completed Gudjonsson Suggestibility Scale and measures of intellectual skills, memory, field-dependence, hostility, and attitudes toward persons in authority. Suggestibility correlated negatively with intelligence quotient and…

Marital Biography and Health at Mid-Life*

PubMed Central

Hughes, Mary Elizabeth; Waite, Linda J.

2011-01-01

This article develops a series of hypotheses about the long-term effects of one’s history of marriage, divorce, and widowhood on health, and it tests those hypotheses using data from the Health and Retirement Study. We examine four dimensions of health at mid-life: chronic conditions, mobility limitations, self-rated health, and depressive symptoms. We find that the experience of marital disruption damages health, with the effects still evident years later; among the currently married, those who have ever been divorced show worse health on all dimensions. Both the divorced and widowed who do not remarry show worse health than the currently married on all dimensions. Dimensions of health that seem to develop slowly, such as chronic conditions and mobility limitations, show strong effects of past marital disruption, whereas others, such as depressive symptoms, seem more sensitive to current marital status. Those who spent more years divorced or widowed show more chronic conditions and mobility limitations. PMID:19711810

Linking Microbiota to Human Diseases: A Systems Biology Perspective.

PubMed

Wu, Hao; Tremaroli, Valentina; Bäckhed, Fredrik

2015-12-01

The human gut microbiota encompasses a densely populated ecosystem that provides essential functions for host development, immune maturation, and metabolism. Alterations to the gut microbiota have been observed in numerous diseases, including human metabolic diseases such as obesity, type 2 diabetes (T2D), and irritable bowel syndrome, and some animal experiments have suggested causality. However, few studies have validated causality in humans and the underlying mechanisms remain largely to be elucidated. We discuss how systems biology approaches combined with new experimental technologies may disentangle some of the mechanistic details in the complex interactions of diet, microbiota, and host metabolism and may provide testable hypotheses for advancing our current understanding of human-microbiota interaction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mechanisms underlying the antimotion sickness effects of psychostimulants

NASA Technical Reports Server (NTRS)

Kohl, Randall L.; Lewis, Michael R.

1987-01-01

Data related to the mechanism responsible for the antimotion sickness effects of psychostimulants such as amphetamine are examined. From the analysis of current literature and new evidence, the following three hypotheses are suggested: (1) selective enhancement of dopaminergic, but not noradrenergic, transmission is sufficient to account for amphetamine-induced resistance and, perhaps, for natural resistance to motion sickness; (2) the site of this enhanced dopaminergic transmission is probably within the basal ganglia; and (3) the neuropharmacology of the basal ganglia, but not of the brain-stem vestibular areas, can account for the therapeutic synergism of scopolamine and amphetamine. The therapeutic action of psychostimulants may be dissociable from some of their side effects, particularly cardiovascular effects related to peripheral norepinephrine release.

The politics of socioeconomic status: how socioeconomic status may influence political attitudes and engagement.

PubMed

Brown-Iannuzzi, Jazmin L; Lundberg, Kristjen B; McKee, Stephanie

2017-12-01

Socioeconomic status is hypothesized to be one factor informing political attitudes and actions. Presumably, this relationship is rooted in economic self-interest, with individuals preferring policies that would benefit them financially. In addition, these economic policy preferences are assumed to translate into political action. However, the relationships between socioeconomic status and political attitudes and behavior, as well as the psychological mechanisms associated with those relationships, are not straightforward. Here, we briefly review the current state of knowledge on the relationships between socioeconomic status and political attitudes and behavior. Overall, the research suggests that while socioeconomic status informs political attitudes toward economic policies, these attitudes may not correlate with complementary political behavior. Copyright © 2017. Published by Elsevier Ltd.

Ovarian function: a theory of relativity.

PubMed

Weghofer, Andrea; Gleicher, Norbert

2009-01-01

Kol and Homburg recently hypothesized in these pages that the change, rather than currently evaluated absolute hormone values, is important for biological processes. We fully agree, but wish, with this communication, to add to their concept: opposing forces, balancing each other, in order to maintain a system's stability, permeates nature. Loss of such equilibrium, in turn, results in systemic malfunctions with, at times, adverse consequences. Extrapolating to Kol and Homburg's hypothesis, this observation would suggest that not only changes in any given hormone carry biological messages, but that final message derives from hormonal ratios between hormones which oppose each other in physiological effects. In full concurrence to Kol and Homburg, this concept could give rise to better diagnosis and treatment of infertility problems.

Management of Chronic Facial Pain

PubMed Central

Williams, Christopher G.; Dellon, A. Lee; Rosson, Gedge D.

2009-01-01

Pain persisting for at least 6 months is defined as chronic. Chronic facial pain conditions often take on lives of their own deleteriously changing the lives of the sufferer. Although much is known about facial pain, it is clear that those physicians who treat these conditions should continue elucidating the mechanisms and defining successful treatment strategies for these life-changing conditions. This article will review many of the classic causes of chronic facial pain due to the trigeminal nerve and its branches that are amenable to surgical therapies. Testing of facial sensibility is described and its utility introduced. We will also introduce some of the current hypotheses of atypical facial pain and headaches secondary to chronic nerve compressions and will suggest possible treatment strategies. PMID:22110799

Cultural differences define diagnosis and genomic medicine practice: implications for undiagnosed diseases program in China.

PubMed

Duan, Xiaohong; Markello, Thomas; Adams, David; Toro, Camilo; Tifft, Cynthia; Gahl, William A; Boerkoel, Cornelius F

2013-09-01

Despite the current acceleration and increasing leadership of Chinese genetics research, genetics and its clinical application have largely been imported to China from the Occident. Neither genetics nor the scientific reductionism underpinning its clinical application is integral to the traditional Chinese worldview. Given that disease concepts and their incumbent diagnoses are historically derived and culturally meaningful, we hypothesize that the cultural expectations of genetic diagnoses and medical genetics practice differ between the Occident and China. Specifically, we suggest that an undiagnosed diseases program in China will differ from the recently established Undiagnosed Diseases Program at the United States National Institutes of Health; a culturally sensitive concept will integrate traditional Chinese understanding of disease with the scientific reductionism of Occidental medicine.

Paleodistributions and Comparative Molecular Phylogeography of Leafcutter Ants (Atta spp.) Provide New Insight into the Origins of Amazonian Diversity

PubMed Central

Solomon, Scott E.; Bacci, Mauricio; Martins, Joaquim; Vinha, Giovanna Gonçalves; Mueller, Ulrich G.

2008-01-01

The evolutionary basis for high species diversity in tropical regions of the world remains unresolved. Much research has focused on the biogeography of speciation in the Amazon Basin, which harbors the greatest diversity of terrestrial life. The leading hypotheses on allopatric diversification of Amazonian taxa are the Pleistocene refugia, marine incursion, and riverine barrier hypotheses. Recent advances in the fields of phylogeography and species-distribution modeling permit a modern re-evaluation of these hypotheses. Our approach combines comparative, molecular phylogeographic analyses using mitochondrial DNA sequence data with paleodistribution modeling of species ranges at the last glacial maximum (LGM) to test these hypotheses for three co-distributed species of leafcutter ants (Atta spp.). The cumulative results of all tests reject every prediction of the riverine barrier hypothesis, but are unable to reject several predictions of the Pleistocene refugia and marine incursion hypotheses. Coalescent dating analyses suggest that population structure formed recently (Pleistocene-Pliocene), but are unable to reject the possibility that Miocene events may be responsible for structuring populations in two of the three species examined. The available data therefore suggest that either marine incursions in the Miocene or climate changes during the Pleistocene—or both—have shaped the population structure of the three species examined. Our results also reconceptualize the traditional Pleistocene refugia hypothesis, and offer a novel framework for future research into the area. PMID:18648512

Conceptual frameworks and methods for advancing invasion ecology.

PubMed

Heger, Tina; Pahl, Anna T; Botta-Dukát, Zoltan; Gherardi, Francesca; Hoppe, Christina; Hoste, Ivan; Jax, Kurt; Lindström, Leena; Boets, Pieter; Haider, Sylvia; Kollmann, Johannes; Wittmann, Meike J; Jeschke, Jonathan M

2013-09-01

Invasion ecology has much advanced since its early beginnings. Nevertheless, explanation, prediction, and management of biological invasions remain difficult. We argue that progress in invasion research can be accelerated by, first, pointing out difficulties this field is currently facing and, second, looking for measures to overcome them. We see basic and applied research in invasion ecology confronted with difficulties arising from (A) societal issues, e.g., disparate perceptions of invasive species; (B) the peculiarity of the invasion process, e.g., its complexity and context dependency; and (C) the scientific methodology, e.g., imprecise hypotheses. To overcome these difficulties, we propose three key measures: (1) a checklist for definitions to encourage explicit definitions; (2) implementation of a hierarchy of hypotheses (HoH), where general hypotheses branch into specific and precisely testable hypotheses; and (3) platforms for improved communication. These measures may significantly increase conceptual clarity and enhance communication, thus advancing invasion ecology.

Fossil moonseeds from the Paleogene of West Gondwana (Patagonia, Argentina).

PubMed

Jud, Nathan A; Iglesias, Ari; Wilf, Peter; Gandolfo, Maria A

2018-06-08

The fossil record is critical for testing biogeographic hypotheses. Menispermaceae (moonseeds) are a widespread family with a rich fossil record and alternative hypotheses related to their origin and diversification. The family is well-represented in Cenozoic deposits of the northern hemisphere, but the record in the southern hemisphere is sparse. Filling in the southern record of moonseeds will improve our ability to evaluate alternative biogeographic hypotheses. Fossils were collected from the Salamanca (early Paleocene, Danian) and the Huitrera (early Eocene, Ypresian) formations in Chubut Province, Argentina. We photographed them using light microscopy, epifluorescence, and scanning electron microscopy and compared the fossils with similar extant and fossil Menispermaceae using herbarium specimens and published literature. We describe fossil leaves and endocarps attributed to Menispermaceae from Argentinean Patagonia. The leaves are identified to the family, and the endocarps are further identified to the tribe Cissampelideae. The Salamancan endocarp is assigned to the extant genus Stephania. These fossils significantly expand the known range of Menispermaceae in South America, and they include the oldest (ca. 64 Ma) unequivocal evidence of the family worldwide. Our findings highlight the importance of West Gondwana in the evolution of Menispermaceae during the Paleogene. Currently, the fossil record does not discern between a Laurasian or Gondwanan origin; however, it does demonstrate that Menispermaceae grew well outside the tropics by the early Paleocene. The endocarps' affinity with Cissampelideae suggests that diversification of the family was well underway by the earliest Paleocene. © 2018 The Authors. American Journal of Botany is published by Wiley Periodicals, Inc. on behalf of the Botanical Society of America.

Evolutionary History of Chemosensory-Related Gene Families across the Arthropoda

PubMed Central

Eyun, Seong-il; Soh, Ho Young; Posavi, Marijan; Munro, James B.; Hughes, Daniel S.T.; Murali, Shwetha C.; Qu, Jiaxin; Dugan, Shannon; Lee, Sandra L.; Chao, Hsu; Dinh, Huyen; Han, Yi; Doddapaneni, HarshaVardhan; Worley, Kim C.; Muzny, Donna M.; Park, Eun-Ok; Silva, Joana C.; Gibbs, Richard A.; Richards, Stephen; Lee, Carol Eunmi

2017-01-01

Abstract Chemosensory-related gene (CRG) families have been studied extensively in insects, but their evolutionary history across the Arthropoda had remained relatively unexplored. Here, we address current hypotheses and prior conclusions on CRG family evolution using a more comprehensive data set. In particular, odorant receptors were hypothesized to have proliferated during terrestrial colonization by insects (hexapods), but their association with other pancrustacean clades and with independent terrestrial colonizations in other arthropod subphyla have been unclear. We also examine hypotheses on which arthropod CRG family is most ancient. Thus, we reconstructed phylogenies of CRGs, including those from new arthropod genomes and transcriptomes, and mapped CRG gains and losses across arthropod lineages. Our analysis was strengthened by including crustaceans, especially copepods, which reside outside the hexapod/branchiopod clade within the subphylum Pancrustacea. We generated the first high-resolution genome sequence of the copepod Eurytemora affinis and annotated its CRGs. We found odorant receptors and odorant binding proteins present only in hexapods (insects) and absent from all other arthropod lineages, indicating that they are not universal adaptations to land. Gustatory receptors likely represent the oldest chemosensory receptors among CRGs, dating back to the Placozoa. We also clarified and confirmed the evolutionary history of antennal ionotropic receptors across the Arthropoda. All antennal ionotropic receptors in E. affinis were expressed more highly in males than in females, suggestive of an association with male mate-recognition behavior. This study is the most comprehensive comparative analysis to date of CRG family evolution across the largest and most speciose metazoan phylum Arthropoda. PMID:28460028

Hypotheses for Near-Surface Exchange of Methane on Mars.

PubMed

Hu, Renyu; Bloom, A Anthony; Gao, Peter; Miller, Charles E; Yung, Yuk L

2016-07-01

The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could explain this variability. Using the temperature and humidity measurements from the rover, we find that perchlorate salts in the regolith deliquesce to form liquid solutions, and deliquescence progresses to deeper subsurface in the season of the methane spikes. We therefore formulate the following three testable hypotheses. The first scenario is that the regolith in Gale Crater adsorbs methane when dry and releases this methane to the atmosphere upon deliquescence. The adsorption energy needs to be 36 kJ mol(-1) to explain the magnitude of the methane spikes, higher than existing laboratory measurements. The second scenario is that microorganisms convert organic matter in the soil to methane when they are in liquid solutions. This scenario does not require regolith adsorption but entails extant life on Mars. The third scenario is that deep subsurface aquifers produce the bursts of methane. Continued in situ measurements of methane and water, as well as laboratory studies of adsorption and deliquescence, will test these hypotheses and inform the existence of the near-surface reservoir and its exchange with the atmosphere. Mars-Methane-Astrobiology-Regolith. Astrobiology 16, 539-550.

How prayer heals: a theoretical model.

PubMed

Levin, J S

1996-01-01

This article presents a theoretical model that outlines various possible explanations for the healing effects of prayer. Four classes of mechanisms are defined on the basis of whether healing has naturalistic or supernatural origins and whether it operates locally or nonlocally. Through this framework, most of the currently proposed hypotheses for understanding absent healing and other related phenomena-hypotheses that invoke such concepts as subtle energy, psi, consciousness, morphic fields, and extended mind-are shown to be no less naturalistic than the Newtonian, mechanistic forces of allopathic biomedicine so often derided for their materialism. In proposing that prayer may heal through nonlocal means according to mechanisms and theories proposed by the new physics, Dossey is almost alone among medical scholars in suggesting the possible limitations and inadequacies of hypotheses based on energies, forces, and fields. Yet even such nonlocal effects can be conceived of as naturalistic; that is, they are explained by physical laws that may be unbelievable or unfamiliar to most physicians but that are nonetheless becoming recognized as operant laws of the natural universe. The concept of the supernatural, however, is something altogether different, and is, by definition, outside of or beyond nature. Herein may reside an either wholly or partly transcendent Creator-God who is believed by many to heal through means that transcend the laws of the created universe, both its local and nonlocal elements, and that are thus inherently inaccessible to and unknowable by science. Such an explanation for the effects of prayer merits consideration and, despite its unprovability by medical science, should not be dismissed out of hand.

Hypotheses for Near-Surface Exchange of Methane on Mars

NASA Astrophysics Data System (ADS)

Hu, Renyu; Bloom, A. Anthony; Gao, Peter; Miller, Charles E.; Yung, Yuk L.

2016-07-01

The Curiosity rover recently detected a background of 0.7 ppb and spikes of 7 ppb of methane on Mars. This in situ measurement reorients our understanding of the martian environment and its potential for life, as the current theories do not entail any geological source or sink of methane that varies sub-annually. In particular, the 10-fold elevation during the southern winter indicates episodic sources of methane that are yet to be discovered. Here we suggest a near-surface reservoir could explain this variability. Using the temperature and humidity measurements from the rover, we find that perchlorate salts in the regolith deliquesce to form liquid solutions, and deliquescence progresses to deeper subsurface in the season of the methane spikes. We therefore formulate the following three testable hypotheses. The first scenario is that the regolith in Gale Crater adsorbs methane when dry and releases this methane to the atmosphere upon deliquescence. The adsorption energy needs to be 36 kJ mol-1 to explain the magnitude of the methane spikes, higher than existing laboratory measurements. The second scenario is that microorganisms convert organic matter in the soil to methane when they are in liquid solutions. This scenario does not require regolith adsorption but entails extant life on Mars. The third scenario is that deep subsurface aquifers produce the bursts of methane. Continued in situ measurements of methane and water, as well as laboratory studies of adsorption and deliquescence, will test these hypotheses and inform the existence of the near-surface reservoir and its exchange with the atmosphere.

Association between exposure to antimicrobial household products and allergic symptoms

PubMed Central

Hong, Soyoung; Kwon, Ho-Jang; Choi, Won-Jun; Lim, Wan Ryung; Kim, Jeonghoon; Kim, KyooSang

2014-01-01

Objectives Antimicrobial chemicals are used in a variety of household and personal care products. Exposure to antimicrobial household products has been hypothesized to lead to allergic diseases in children. Methods We investigated antimicrobial household product exposure and allergic symptoms in Korean children. An antimicrobial exposure (AE) score was derived. To examine the symptoms of allergic diseases (current wheeze, current rhinitis, and current eczema) in the past 12 months, we used a questionnaire based on the core module of the International Study of Asthma and Allergies in Children. Complete data for the analysis were available for 25,805 of the 35,590 (72.5%) children. Results The prevalence of current allergic diseases was as follows: wheeze, 5.6%; allergic rhinitis, 32.6%; and eczema, 17.7%. The mean (standard deviation) AE score was 14.3 (9.3) (range: 0-40). Compared with subjects with a low AE score (reference), subjects with a high AE score (fourth quartile) were more likely to have symptoms of wheezing and allergic rhinitis (adjusted odds ratio [aOR] for wheezing 1.24, 95% confidence interval [CI], 1.05-1.45, p for trend=0.24; aOR for allergic rhinitis 1.30, 95% CI, 1.20-1.40, p<0.01). Conclusions These findings suggest that frequent use of antimicrobial household products was associated with current wheeze and current allergic rhinitis. PMID:25420879

Human Papilloma virus in Juvenile Nasopharyngeal Angiofibroma: possible recent trend.

PubMed

Mishra, Anupam; Sachadeva, Monica; Jain, Ankita; Shukla, Nimisha Mishra; Pandey, Amita

2016-01-01

Juvenile nasopharyngeal angiofibroma (JNA) has witnessed a four-fold increase in the incidence at our facility in the current decade as compared to the 1980s. With high global incidence of human pappilloma virus (HPV) related oropharyngeal cancer in India, we hypothesize its implication in JNA as it has not yet been reported. Clinico-Surgical variables of 6 patients of JNA were included for correlation and their tissue samples were subjected to western blotting (WB), polymerase chain reaction and immunoflorescence to demonstrate a definite association with HPV. In addition 6 control samples (adenoids) underwent WB analysis. A universal presence of HPV with JNA is novel 'discovery' and has suggested a possibility of a definite association. Only a single case suggested weak infection. None of the controls suggested infection, thus ruling out the presence of HPV in nasopharynx of normal population. With the dawn of this definite association, no specific conclusions can yet be drawn but a whole plethora of questions have emerged with our novel 'discovery'. Copyright © 2016 Elsevier Inc. All rights reserved.

The evolutionary psychology of hunger.

PubMed

Al-Shawaf, Laith

2016-10-01

An evolutionary psychological perspective suggests that emotions can be understood as coordinating mechanisms whose job is to regulate various psychological and physiological programs in the service of solving an adaptive problem. This paper suggests that it may also be fruitful to approach hunger from this coordinating mechanism perspective. To this end, I put forward an evolutionary task analysis of hunger, generating novel a priori hypotheses about the coordinating effects of hunger on psychological processes such as perception, attention, categorization, and memory. This approach appears empirically fruitful in that it yields a bounty of testable new hypotheses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evolution of pollen morphology in Loranthaceae

PubMed Central

Grímsson, Friðgeir; Grimm, Guido W.; Zetter, Reinhard

2018-01-01

Abstract Earlier studies indicate a strong correlation of pollen morphology and ultrastructure with taxonomy in Loranthaceae. Using high-resolution light microscopy and scanning electron microscopy imaging of the same pollen grains, we document pollen types of 35 genera including 15 studied for the first time. Using a molecular phylogenetic framework based on currently available sequence data with good genus-coverage, we reconstruct trends in the evolution of Loranthaceae pollen and pinpoint traits of high diagnostic value, partly confirming earlier intuitive hypotheses based on morphological observations. We find that pollen morphology in Loranthaceae is strongly linked to phylogenetic relationships. Some pollen types are diagnostic for discrete genera or evolutionary lineages, opening the avenue to recruit dispersed fossil pollen as age constraints for dated phylogenies and as independent data for testing biogeographic scenarios; so far based exclusively on modern-day data. Correspondences and discrepancies between palynological and molecular data and current taxonomic/systematic concepts are identified and suggestions made for future palynological and molecular investigations of Loranthaceae. PMID:29386990

An overview of flux braiding experiments

PubMed Central

Wilmot-Smith, A. L.

2015-01-01

In a number of papers dating back to the 1970s, Parker has hypothesized that, in a perfectly ideal environment, complex photospheric motions acting on a continuous magnetic field will result in the formation of tangential discontinuities corresponding to singular currents. I review direct numerical simulations of the problem and find that the evidence points to a tendency for thin but finite-thickness current layers to form, with thickness exponentially decreasing in time. Given a finite resistivity, these layers will eventually become important and cause the dynamical process of energy release. Accordingly, a body of work focuses on evolution under continual boundary driving. The coronal volume evolves into a highly dynamic but statistically steady state where quantities have a temporally and spatially intermittent nature and where the Poynting flux and dissipation are decoupled on short time scales. Although magnetic braiding is found to be a promising coronal heating mechanism, much work remains to determine its true viability. Some suggestions for future study are offered. PMID:25897088

Role of HLA-B27 in the pathogenesis of ankylosing spondylitis

PubMed Central

Chen, Bin; Li, Jia; He, Chongru; Li, Dahe; Tong, Wenwen; Zou, Yuming; Xu, Weidong

2017-01-01

The study of ankylosing spondylitis (AS) has made significant progress over the last decade. Genome-wide association studies have identified and further substantiated the role of susceptibility genes outside the major histocompatibility complex locus. However, human leukocyte antigen (HLA)-B27 has been suggested to be important in the pathogenesis of AS, contributing to ~20.1% of AS heritability. The current review will present the classical and non-classical forms of HLA-B27, as well as their pathogenic roles, and further discuss the hypotheses regarding the potential pathogenesis of AS. In addition, the association between the pathogenic role of HLA-B27 and inflammatory indexes, including the interleukin-23/−17 axis will be investigated to provide novel insights into the pathogenesis of AS. The aim of the present review is to provide an update of the current research into the pathogenesis of AS, and provide a comprehensive description of the pathogenic role of HLA-B27 in AS. PMID:28259985

Role of HLA-B27 in the pathogenesis of ankylosing spondylitis (Review).

PubMed

Chen, Bin; Li, Jia; He, Chongru; Li, Dahe; Tong, Wenwen; Zou, Yuming; Xu, Weidong

2017-04-01

The study of ankylosing spondylitis (AS) has made significant progress over the last decade. Genome-wide association studies have identified and further substantiated the role of susceptibility genes outside the major histocompatibility complex locus. However, human leukocyte antigen (HLA)‑B27 has been suggested to be important in the pathogenesis of AS, contributing to ~20.1% of AS heritability. The current review will present the classical and non‑classical forms of HLA-B27, as well as their pathogenic roles, and further discuss the hypotheses regarding the potential pathogenesis of AS. In addition, the association between the pathogenic role of HLA‑B27 and inflammatory indexes, including the interleukin-23/‑17 axis will be investigated to provide novel insights into the pathogenesis of AS. The aim of the present review is to provide an update of the current research into the pathogenesis of AS, and provide a comprehensive description of the pathogenic role of HLA-B27 in AS.

Frontiers in the pathogenesis of Alzheimer’s disease

PubMed Central

Sambamurti, Kumar; Jagannatha Rao, K. S.; Pappolla, Miguel A.

2009-01-01

Alzheimer’s disease (AD) is characterized by progressive dementia and brain deposits of the amyloid β protein (Aβ) as senile plaques and the microtubule-associated protein, Tau, as neurofibrillary tangles (NFT). The current treatment of AD is limited to drugs that attempt to correct deficits in the cholinergic pathway or glutamate toxicity. These drugs show some improvement over a short period of time but the disease ultimately requires treatment to prevent and stop the neurodegeneration that affects multiple pathways. The currently favored hypothesis is that Aβ aggregates to toxic forms that induce neurodegeneration. Drugs that reduce Aβ successfully treat transgenic mouse models of AD, but the most promising anti-Aβ vaccination approach did not successfully treat AD in a clinical trial. These studies suggest that AD pathogenesis is a complex phenomenon and requires a more broad-based approach to identify mechanisms of neurodegeneration. Multiple hypotheses have been proposed and the field is ready for a new generation of ideas to develop early diagnostic approaches and develop successful treatment plans. PMID:21416019

Baselines and null hypotheses for climate change: Phytoplankton biomass structure in the California Current

NASA Astrophysics Data System (ADS)

Landry, M. R.; Taylor, A. G.

2016-02-01

Phytoplankton community structure is shaped both by the bottom-up influences of the physical-chemical environment and by the top-down impacts of food webs. Emergent patterns in the contemporary ocean can thus be "null hypotheses" of future changes assuming that the underlying structuring relationships remain intact but only shift spatially. To provide such a context for the California Current Ecosystem (CCE) and adjacent open-ocean ecosystems, we used a combination of digital epifluorescence microscopy and flow cytometry to investigate variability of phytoplankton biomass, composition and size structure across gradients of ecosystem richness, as represented by total autotrophic carbon (AC). Biomass of large micro-sized (>20 µm) phytoplankton increases as a power function with system richness. Nano-sized cells (2-20 µm) increase at a lower rate at low AC, and level off at high AC. Pico-sized cells (<2-µm) do not clearly dominate at low AC and decline significantly at high AC, neither predicted by competition theory. This study provides several new insights into structural relationships and mechanisms in the CCE: 1) diatoms and dinoflagellates co-dominate the micro-phytoplankton size class throughout the range of system richness; 2) nano-phytoplankton co-dominate biomass in oligotrophic (low AC) waters, suggesting widespread mixotrophy rather than direct competition with pico-phytoplankton for nutrients; and 3) the pico-phytoplankton decline at high AC impacts small eukaryotes as well as photosynthetic bacteria, consistent with a broad stimulation of grazing pressure on all bacterial-sized cells in richer systems. Observed variability in heterotrophic bacteria and nano-flagellate grazers with system richness is consistent with this mechanism.

Safety behaviors and sleep effort predict sleep disturbance and fatigue in an outpatient sample with anxiety and depressive disorders.

PubMed

Fairholme, Christopher P; Manber, Rachel

2014-03-01

Theoretical and empirical support for the role of dysfunctional beliefs, safety behaviors, and increased sleep effort in the maintenance of insomnia has begun to accumulate. It is not yet known how these factors predict sleep disturbance and fatigue occurring in the context of anxiety and mood disorders. It was hypothesized that these three insomnia-specific cognitive-behavioral factors would be uniquely associated with insomnia and fatigue among patients with emotional disorders after adjusting for current symptoms of anxiety and depression and trait levels of neuroticism and extraversion. Outpatients with a current anxiety or mood disorder (N = 63) completed self-report measures including the Dysfunctional Beliefs About Sleep Scale (DBAS), Sleep-Related Safety Behaviors Questionnaire (SRBQ), Glasgow Sleep Effort Scale (GSES), Pittsburgh Sleep Quality Index (PSQI), NEO Five-Factor Inventory (FFI), and the 21-item Depression Anxiety and Stress Scale (DASS). Multivariate path analysis was used to evaluate study hypotheses. SRBQ (B = .60, p < .001, 95% CI [.34, .86]) and GSES (B = .31, p < .01, 95% CI [.07, .55]) were both significantly associated with PSQI. There was a significant interaction between SRBQ and DBAS (B = .25, p < .05, 95% CI [.04, .47]) such that the relationship between safety behaviors and fatigue was strongest among individuals with greater levels of dysfunctional beliefs. Findings are consistent with cognitive behavioral models of insomnia and suggest that sleep-specific factors might be important treatment targets among patients with anxiety and depressive disorders with disturbed sleep. Copyright © 2013 Elsevier Inc. All rights reserved.

The Right-Wing Attack on Women.

ERIC Educational Resources Information Center

Fishman, Walda Katz

A personal evaluation is expressed on the changing role of women in the United States as a result of current social attitudes and of recent legislation regarding medical, economic, and educational matters. It is hypothesized that the United States is currently experiencing an extreme and growing right-wing political movement whose targets include…

Early experiences building a software quality prediction model

NASA Technical Reports Server (NTRS)

Agresti, W. W.; Evanco, W. M.; Smith, M. C.

1990-01-01

Early experiences building a software quality prediction model are discussed. The overall research objective is to establish a capability to project a software system's quality from an analysis of its design. The technical approach is to build multivariate models for estimating reliability and maintainability. Data from 21 Ada subsystems were analyzed to test hypotheses about various design structures leading to failure-prone or unmaintainable systems. Current design variables highlight the interconnectivity and visibility of compilation units. Other model variables provide for the effects of reusability and software changes. Reported results are preliminary because additional project data is being obtained and new hypotheses are being developed and tested. Current multivariate regression models are encouraging, explaining 60 to 80 percent of the variation in error density of the subsystems.

Generation and Propagation of Nonlinear Internal Waves in Sheared Currents Over the Washington Continental Shelf

NASA Astrophysics Data System (ADS)

Hamann, Madeleine M.; Alford, Matthew H.; Mickett, John B.

2018-04-01

The generation, propagation, and dissipation of nonlinear internal waves (NLIW) in sheared background currents is examined using 7 days of shipboard microstructure surveys and two moorings on the continental shelf offshore of Washington state. Surveys near the hypothesized generation region show semi-diurnal (D2) energy flux is onshore and that the ratio of energy flux to group speed times energy (F/cgE) increases sharply at the shelf break, suggesting that the incident D2 internal tide is partially reflected and partially transmitted. NLIW appear at an inshore mooring at the leading edge of the onshore phase of the baroclinic tide, consistent with nonlinear transformation of the shoaling internal tide as their generation mechanism. Of the D2 energy flux observed at the eastern extent of the generation region (133 ± 18 Wm-1), approximately 30% goes into the NLIW observed inshore (36 ± 11 Wm-1). Inshore of the moorings, 7 waves are tracked into shallow (30-40 m) water, where a vertically sheared, southward current becomes strong. As train-like waves propagate onshore, wave amplitudes of 25-30 m and energies of 5 MJ decrease to 12 m and 10 kJ, respectively. The observed direction of propagation rotates from 30° N of E to ˜30° S of E in the strongly sheared region. Linear ray tracing using the Taylor-Goldstein equation to incorporate parallel shear effects accounts for only a small portion of the observed rotation, suggesting that three-dimensionality of the wave crests and the background currents is important here.

Recognition of the polycistronic nature of human genes is critical to understanding the genotype-phenotype relationship.

PubMed

Brunet, Marie A; Levesque, Sébastien A; Hunting, Darel J; Cohen, Alan A; Roucou, Xavier

2018-05-01

Technological advances promise unprecedented opportunities for whole exome sequencing and proteomic analyses of populations. Currently, data from genome and exome sequencing or proteomic studies are searched against reference genome annotations. This provides the foundation for research and clinical screening for genetic causes of pathologies. However, current genome annotations substantially underestimate the proteomic information encoded within a gene. Numerous studies have now demonstrated the expression and function of alternative (mainly small, sometimes overlapping) ORFs within mature gene transcripts. This has important consequences for the correlation of phenotypes and genotypes. Most alternative ORFs are not yet annotated because of a lack of evidence, and this absence from databases precludes their detection by standard proteomic methods, such as mass spectrometry. Here, we demonstrate how current approaches tend to overlook alternative ORFs, hindering the discovery of new genetic drivers and fundamental research. We discuss available tools and techniques to improve identification of proteins from alternative ORFs and finally suggest a novel annotation system to permit a more complete representation of the transcriptomic and proteomic information contained within a gene. Given the crucial challenge of distinguishing functional ORFs from random ones, the suggested pipeline emphasizes both experimental data and conservation signatures. The addition of alternative ORFs in databases will render identification less serendipitous and advance the pace of research and genomic knowledge. This review highlights the urgent medical and research need to incorporate alternative ORFs in current genome annotations and thus permit their inclusion in hypotheses and models, which relate phenotypes and genotypes. © 2018 Brunet et al.; Published by Cold Spring Harbor Laboratory Press.

Cue and Target Processing Modulate the Onset of Inhibition of Return

ERIC Educational Resources Information Center

Gabay, Shai; Chica, Ana B.; Charras, Pom; Funes, Maria J.; Henik, Avishai

2012-01-01

Inhibition of return (IOR) is modulated by task set and appears later in discrimination tasks than in detection tasks. Several hypotheses have been suggested to account for this difference. We tested three of these hypotheses in two experiments by examining the influence of cue and target level of processing on the onset of IOR. In the first…

Molecular engineering and measurements to test hypothesized mechanisms in single molecule conductance switching.

PubMed

Moore, Amanda M; Dameron, Arrelaine A; Mantooth, Brent A; Smith, Rachel K; Fuchs, Daniel J; Ciszek, Jacob W; Maya, Francisco; Yao, Yuxing; Tour, James M; Weiss, Paul S

2006-02-15

Six customized phenylene-ethynylene-based oligomers have been studied for their electronic properties using scanning tunneling microscopy to test hypothesized mechanisms of stochastic conductance switching. Previously suggested mechanisms include functional group reduction, functional group rotation, backbone ring rotation, neighboring molecule interactions, bond fluctuations, and hybridization changes. Here, we test these hypotheses experimentally by varying the molecular designs of the switches; the ability of the molecules to switch via each hypothetical mechanism is selectively engineered into or out of each molecule. We conclude that hybridization changes at the molecule-surface interface are responsible for the switching we observe.

Economic and evolutionary hypotheses for cross-population variation in parochialism.

PubMed

Hruschka, Daniel J; Henrich, Joseph

2013-09-11

Human populations differ reliably in the degree to which people favor family, friends, and community members over strangers and outsiders. In the last decade, researchers have begun to propose several economic and evolutionary hypotheses for these cross-population differences in parochialism. In this paper, we outline major current theories and review recent attempts to test them. We also discuss the key methodological challenges in assessing these diverse economic and evolutionary theories for cross-population differences in parochialism.

The acceptability and feasibility of the Positive Reinforcement Opportunity Project, a community-based contingency management methamphetamine treatment program for gay and bisexual men in San Francisco.

PubMed

Strona, Frank V; McCright, Jacque; Hjord, Hanna; Ahrens, Katherine; Tierney, Steven; Shoptaw, Steven; Klausner, Jeffrey D

2006-11-01

The Positive Reinforcement Opportunity Project (PROP) was a pilot program developed to build on the efficacy of contingency management (CM) using positive reinforcement to address the treatment needs of gay and bisexual men currently using crystal methamphetamines (meth). It was hypothesized that a version of CM could be implemented in San Francisco that was less costly than traditional treatment methods and reached gay and other MSM using meth who also engaged in high-risk sexual activity. Of the 178 men who participated in PROPfrom December 2003 to December 2005, many self-reported behaviors for acquiring and spreading sexually transmitted diseases including HIV infection. During the initial intake, 73% reported high-risk sexual behavior in the prior three months, with 60% reporting anal receptive and/or insertive sex without condoms. This report describes the implementation of PROP and suggest both its limitations and potential strengths. Initial findings suggest that PROP was a useful and low cost substance use treatment option that resulted in a 35% 90-day completion rate, which is similar to graduation rates from traditional, more costly treatment options. Further evaluation of the limited data from three- and six-month follow-up of those who completed PROP is currently ongoing.

Insomnia and suicidal ideation and behaviors in former and current U.S. service members: Does depression mediate the relations?

PubMed

Allan, Nicholas P; Conner, Kenneth R; Pigeon, Wilfred R; Gros, Daniel F; Salami, Temilola K; Stecker, Tracy

2017-06-01

Insomnia is a risk factor for Suicidal Ideation (SI) and Behavior (SB), yet the nature of the relations is unclear, including the potential mediating role of cognitive and affective/somatic symptoms of depression. It was hypothesized that the impact of insomnia on SI would be mediated through depressive symptoms and that insomnia would directly impact SB. Current and former military service members (N =405; M age =31.6 years, SD =7.3; 90.4% male, 76.5% White) who endorsed recent suicidal ideation and/or a history of suicide attempt completed measures of insomnia, depression, SI, and SB at baseline and at month 12 follow-up. Mediation models were conducted using structural equation modeling. Significant mediation from insomnia to baseline SI and month 12 SI was found through cognitive/affective depression. Insomnia was directly related to SB occurring between baseline and month 12 follow-up. These findings suggest that cognitive/affective depression mediates the association with SI but not SB. Results build on research showing the importance of depressive symptoms in SI in particular. The direct and indirect pathways from insomnia to SI/SB suggest that clinicians should be aware of these relations when treating patients reporting insomnia. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

EXPLOSIVE RADIATION OF A BACTERIAL SPECIES GROUP

PubMed Central

Morlon, Hélène; Kemps, Brian D.; Plotkin, Joshua B.; Brisson, Dustin

2013-01-01

The current diversity of life on earth is the product of macroevolutionary processes that have shaped the dynamics of diversification. Although the tempo of diversification has been studied extensively in macroorganisms, much less is known about the rates of diversification in the exceedingly diverse and species-rich microbiota. Decreases in diversification rates over time, a signature of explosive radiations, are commonly observed in plant and animal lineages. However, the few existing analyses of microbial lineages suggest that the tempo of diversification in prokaryotes may be fundamentally different. Here, we use multilocus and genomic sequence data to test hypotheses about the rate of diversification in a well-studied pathogenic bacterial lineage, Borrelia burgdorferi sensu lato (sl). Our analyses support the hypothesis that an explosive radiation of lineages occurred near the origin of the clade, followed by a sharp decay in diversification rates. These results suggest that explosive radiations may be a general feature of evolutionary history across the tree of life. PMID:22834754

Longitudinal Mediators of Relations Between Family Violence and Adolescent Dating Aggression Perpetration

PubMed Central

Reyes, H. Luz McNaughton; Foshee, Vangie A.; Fortson, Beverly L.; Valle, Linda A.; Breiding, Matthew J.; Merrick, Melissa T.

2015-01-01

Few longitudinal studies have examined the pathways through which family violence leads to dating aggression. In the current study the authors used 3 waves of data obtained from 8th- and 9th-grade adolescents (N = 1,965) to examine the hypotheses that the prospective relationship between witnessing family violence and directly experiencing violence and physical dating aggression perpetration is mediated by 3 constructs: (a) normative beliefs about dating aggression (norms), (b) anger dysregulation, and (c) depression. Results from cross-lagged regression models suggest that the relationship between having been hit by an adult and dating aggression is mediated by changes in norms and anger dysregulation, but not depression. No evidence of indirect effects from witnessing family violence to dating aggression was found through any of the proposed mediators. Taken together, the findings suggest that anger dysregulation and normative beliefs are potential targets for dating abuse prevention efforts aimed at youth who have directly experienced violence. PMID:26719602

Massive remobilization of permafrost carbon during post-glacial warming

PubMed Central

Tesi, T.; Muschitiello, F.; Smittenberg, R. H.; Jakobsson, M.; Vonk, J. E.; Hill, P.; Andersson, A.; Kirchner, N.; Noormets, R.; Dudarev, O.; Semiletov, I.; Gustafsson, Ö

2016-01-01

Recent hypotheses, based on atmospheric records and models, suggest that permafrost carbon (PF-C) accumulated during the last glaciation may have been an important source for the atmospheric CO2 rise during post-glacial warming. However, direct physical indications for such PF-C release have so far been absent. Here we use the Laptev Sea (Arctic Ocean) as an archive to investigate PF-C destabilization during the last glacial–interglacial period. Our results show evidence for massive supply of PF-C from Siberian soils as a result of severe active layer deepening in response to the warming. Thawing of PF-C must also have brought about an enhanced organic matter respiration and, thus, these findings suggest that PF-C may indeed have been an important source of CO2 across the extensive permafrost domain. The results challenge current paradigms on the post-glacial CO2 rise and, at the same time, serve as a harbinger for possible consequences of the present-day warming of PF-C soils. PMID:27897191

Massive remobilization of permafrost carbon during post-glacial warming

NASA Astrophysics Data System (ADS)

Tesi, T.; Muschitiello, F.; Smittenberg, R. H.; Jakobsson, M.; Vonk, J. E.; Hill, P.; Andersson, A.; Kirchner, N.; Noormets, R.; Dudarev, O.; Semiletov, I.; Gustafsson, Ö.

2016-11-01

Recent hypotheses, based on atmospheric records and models, suggest that permafrost carbon (PF-C) accumulated during the last glaciation may have been an important source for the atmospheric CO2 rise during post-glacial warming. However, direct physical indications for such PF-C release have so far been absent. Here we use the Laptev Sea (Arctic Ocean) as an archive to investigate PF-C destabilization during the last glacial-interglacial period. Our results show evidence for massive supply of PF-C from Siberian soils as a result of severe active layer deepening in response to the warming. Thawing of PF-C must also have brought about an enhanced organic matter respiration and, thus, these findings suggest that PF-C may indeed have been an important source of CO2 across the extensive permafrost domain. The results challenge current paradigms on the post-glacial CO2 rise and, at the same time, serve as a harbinger for possible consequences of the present-day warming of PF-C soils.

Evaluating Nonattachment and Decentering as Possible Mediators of the Link Between Mindfulness and Psychological Distress in a Nonclinical College Sample.

PubMed

Bhambhani, Yash; Cabral, Gail

2016-10-01

Although increasing evidence shows that mindfulness is positively related to mental health, the nature and mechanisms of this relationship are not fully understood. Based on previous research findings and suggestions, the authors of the current study hypothesized that decentering and nonattachment are 2 variables that mediate the relationship between mindfulness and psychological distress. A nonclinical, non-treatment-seeking sample of 308 students and employees from a middle-class, primarily Caucasian university filled out mindfulness, decentering, nonattachment, and mental distress measures online. Mediational analyses failed to support the hypothesis. Results suggest that mindfulness and nonattachment are independent predictors of nonclinical psychological distress and fully explain the effect of decentering on psychological distress. Results should be interpreted with caution and not generalized to clinical issues. A more comprehensive look into the mechanisms of mindfulness, especially with rigorous experimental, longitudinal studies, is warranted. The authors stress the importance of checking alternative, equivalent models in mediation studies. © The Author(s) 2015.

The Intersection of Theory and Application in Elucidating Pattern Formation in Developmental Biology

PubMed Central

Othmer, Hans G.; Painter, Kevin; Umulis, David; Xue, Chuan

2009-01-01

We discuss theoretical and experimental approaches to three distinct developmental systems that illustrate how theory can influence experimental work and vice-versa. The chosen systems – Drosophila melanogaster, bacterial pattern formation, and pigmentation patterns – illustrate the fundamental physical processes of signaling, growth and cell division, and cell movement involved in pattern formation and development. These systems exemplify the current state of theoretical and experimental understanding of how these processes produce the observed patterns, and illustrate how theoretical and experimental approaches can interact to lead to a better understanding of development. As John Bonner said long ago ‘We have arrived at the stage where models are useful to suggest experiments, and the facts of the experiments in turn lead to new and improved models that suggest new experiments. By this rocking back and forth between the reality of experimental facts and the dream world of hypotheses, we can move slowly toward a satisfactory solution of the major problems of developmental biology.’ PMID:19844610

The Road To Cnidaria: History of Phylogeny of the Myxozoa.

PubMed

Foox, Jonathan; Siddall, Mark E

2015-06-01

Myxozoans are a clade of highly derived cnidarians. The phylogenetic identity of these extremely simplified parasites of aquatic vertebrates and invertebrates had long been uncertain, with all early classifications designating Myxozoa as protists. Though suggestions were frequently made that the infective spores of these parasites are multicellular and possibly of cnidarian origin, it would take a phylogenetic analysis of ultrastructural developmental characters in combination with rRNA gene sequences to verify the Myxozoa as secondarily reduced cnidarians, sister to the polypoidozoan parasite Polypodium hydriforme . While a series of subsequent molecular studies suggested hypotheses of Myxozoa as basal bilaterians, triploblasts, or even nematodes, phylogenomic analyses with improved taxon sampling corroborated the landmark paper that verified the cnidarian nature of this group. This review of the body of phylogenetic work on Myxozoa aims to clarify historical progress and current knowledge, as well as to emphasize the opportune position that myxozoan biologists now are in, to address fundamental questions of cell biology of these parasites as well as the evolution of animal life.

The implicit rules of combat.

PubMed

Romero, Gorge A; Pham, Michael N; Goetz, Aaron T

2014-12-01

Conspecific violence has been pervasive throughout evolutionary history. The current research tested the hypotheses that individuals implicitly categorize combative contexts (i.e., play fighting, status contests, warfare, and anti-exploitative violence) and use the associated contextual information to guide expectations of combative tactics. Using U.S. and non-U.S. samples, Study 1 demonstrated consistent classification of combative contexts from scenarios for which little information was given and predictable shifts in the acceptability of combative tactics across contexts. Whereas severe tactics (e.g., eye-gouging) were acceptable in warfare and anti-exploitative violence, they were unacceptable in status contests and play fights. These results suggest the existence of implicit rules governing the contexts of combat. In Study 2, we explored the reputational consequences of violating these implicit rules. Results suggest that rule violators (e.g., those who use severe tactics in a status contest) are given less respect. These are the first studies to implicate specialized mechanisms for aggression that use contextual cues of violence to guide expectations and behavior.

The evolution of cooperative breeding in the African cichlid fish, Neolamprologus pulcher.

PubMed

Wong, Marian; Balshine, Sigal

2011-05-01

The conundrum of why subordinate individuals assist dominants at the expense of their own direct reproduction has received much theoretical and empirical attention over the last 50 years. During this time, birds and mammals have taken centre stage as model vertebrate systems for exploring why helpers help. However, fish have great potential for enhancing our understanding of the generality and adaptiveness of helping behaviour because of the ease with which they can be experimentally manipulated under controlled laboratory and field conditions. In particular, the freshwater African cichlid, Neolamprologus pulcher, has emerged as a promising model species for investigating the evolution of cooperative breeding, with 64 papers published on this species over the past 27 years. Here we clarify current knowledge pertaining to the costs and benefits of helping in N. pulcher by critically assessing the existing empirical evidence. We then provide a comprehensive examination of the evidence pertaining to four key hypotheses for why helpers might help: (1) kin selection; (2) pay-to-stay; (3) signals of prestige; and (4) group augmentation. For each hypothesis, we outline the underlying theory, address the appropriateness of N. pulcher as a model species and describe the key predictions and associated empirical tests. For N. pulcher, we demonstrate that the kin selection and group augmentation hypotheses have received partial support. One of the key predictions of the pay-to-stay hypothesis has failed to receive any support despite numerous laboratory and field studies; thus as it stands, the evidence for this hypothesis is weak. There have been no empirical investigations addressing the key predictions of the signals of prestige hypothesis. By outlining the key predictions of the various hypotheses, and highlighting how many of these remain to be tested explicitly, our review can be regarded as a roadmap in which potential paths for future empirical research into the evolution of cooperative breeding are proposed. Overall, we clarify what is currently known about cooperative breeding in N. pulcher, address discrepancies among studies, caution against incorrect inferences that have been drawn over the years and suggest promising avenues for future research in fishes and other taxonomic groups. © 2010 The Authors. Biological Reviews © 2010 Cambridge Philosophical Society.

Daydreaming style moderates the relation between working memory and mind wandering: Integrating two hypotheses.

PubMed

Marcusson-Clavertz, David; Cardeña, Etzel; Terhune, Devin Blair

2016-03-01

Mind wandering-mentation unrelated to one's current activity and surroundings-is a ubiquitous phenomenon, but seemingly competing ideas have been proposed regarding its relation to executive cognitive processes. The control-failure hypothesis postulates that executive processes prevent mind wandering, whereas the global availability hypothesis proposes that mind wandering requires executive resources, and thus an excess of such resources enables mind wandering. Here, we examined whether these hypotheses could be reconciled by considering the moderating influence of daydreaming style. We expected that executive resources would be positively related to mind wandering in those who typically experience positive mind wandering mentation, but negatively related in those who typically experience negative mentation. One hundred eleven participants reported mind wandering over 4 days using experience sampling and completed the sustained attention to response task (SART), the symmetry span task, and the Stroop task. There was a significant interaction between working memory and negative, but not positive, daydreaming style on mind wandering: Working memory related positively to mind wandering in those with a low negative style, but negatively in those with a high negative style. In contrast, poor Stroop performance significantly predicted increased mind wandering, but only in those with a low positive style. SART responses did not predict mind wandering although the relation was suggestively enhanced as the difficulty of daily life activities increased, indicating that the SART is more generalizable to high-demanding than low-demanding activities. These results suggest that the content and context of mind wandering episodes play important roles in the relation between executive processes and mind wandering. (c) 2016 APA, all rights reserved).

Evolutionary Transformation of the Palmaris Longus Muscle in Flying Squirrels (Pteromyini: Sciuridae): An Anatomical Consideration of the Origin of the Uniquely Specialized Styliform Cartilage.

PubMed

Kawashima, Tomokazu; Thorington, Richard W; Bohaska, Paula W; Sato, Fumi

2017-02-01

A long-standing issue in squirrel evolution and development is the origin of the styliform cartilage of flying squirrels, which extends laterally from the carpus to support the gliding membrane (patagium). Because the styliform cartilage is one of the uniquely specialized structures permitting gliding locomotion, the knowledge of its origin and surrounding transformation is key for understanding their aerodynamic evolution. The developmental study that would definitely answer this question would be difficult due to the rarity of embryological material. Instead, anatomical examinations have suggested two major hypotheses on the homology of the styliform cartilage: the pisiform bone of other mammals, or an additional carpal structure, such as the ulnar sesamoid of some of the other mammals or the hypothenar cartilage of the non-gliding squirrels. To test these hypotheses, a detailed examination of the anatomy of the carpus of gliding and non-gliding squirrels, and the colugo were undertaken. Based on physical and virtual dissections of the carpus, this study showed that both the pisiform bone and styliform cartilage were present in flying squirrels. This finding is further supported by demonstration that a "true Palmaris longus," with innervation typical for this muscle, inserts on the styliform cartilage. Taken together, our osteological, muscular, and neurological results suggest that the styliform cartilage was transformed in flying squirrels from an initially superficial and ulnar-derived anlagen into its current form. Anat Rec, 300:340-352, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Economic and evolutionary hypotheses for cross-population variation in parochialism

PubMed Central

Hruschka, Daniel J.; Henrich, Joseph

2013-01-01

Human populations differ reliably in the degree to which people favor family, friends, and community members over strangers and outsiders. In the last decade, researchers have begun to propose several economic and evolutionary hypotheses for these cross-population differences in parochialism. In this paper, we outline major current theories and review recent attempts to test them. We also discuss the key methodological challenges in assessing these diverse economic and evolutionary theories for cross-population differences in parochialism. PMID:24062662

Hyperactivity in Boys with Attention-Deficit/Hyperactivity Disorder (ADHD): A Ubiquitous Core Symptom or Manifestation of Working Memory Deficits?

ERIC Educational Resources Information Center

Rapport, Mark D.; Bolden, Jennifer; Kofler, Michael J.; Sarver, Dustin E.; Raiker, Joseph S.; Alderson, R. Matt

2009-01-01

Hyperactivity is currently considered a core and ubiquitous feature of attention-deficit/hyperactivity disorder (ADHD); however, an alternative model challenges this premise and hypothesizes a functional relationship between working memory (WM) and activity level. The current study investigated whether children's activity level is functionally…

Phylogeography of Canada Geese (Branta canadensis) in western North America

USGS Publications Warehouse

Scribner, K.T.; Talbot, S.L.; Pearce, J.M.; Pierson, Barbara J.; Bollinger, K.S.; Derksen, D.V.

2003-01-01

Using molecular genetic markers that differ in mode of inheritance and rate of evolution, we examined levels and partitioning of genetic variation for seven nominal subspecies (11 breeding populations) of Canada Geese (Branta canadensis) in western North America. Gene trees constructed from mtDNA control region sequence data show that subspecies of Canada Geese do not have distinct mtDNA. Large- and small-bodied forms of Canada Geese were highly diverged (0. 077 average sequence divergence) and represent monophyletic groups. A majority (65%) of 20 haplotypes resolved were observed in single breeding locales. However, within both large- and small-bodied forms certain haplotypes occurred across multiple subspecies. Population trees for both nuclear (microsatellites) and mitochondrial markers were generally concordant and provide resolution of population and subspecific relationships indicating incomplete lineage sorting. All populations and subspecies were genetically diverged, but to varying degrees. Analyses of molecular variance, nested-clade and coalescence-based analyses of mtDNA suggest that both historical (past fragmentation) and contemporary forces have been important in shaping current spatial genetic distributions. Gene flow appears to be ongoing though at different rates, even among currently recognized subspecies. The efficacy of current subspecific taxonomy is discussed in light of hypothesized historical vicariance and current demographic trends of management and conservation concern.

Resistive switching near electrode interfaces: Estimations by a current model

NASA Astrophysics Data System (ADS)

Schroeder, Herbert; Zurhelle, Alexander; Stemmer, Stefanie; Marchewka, Astrid; Waser, Rainer

2013-02-01

The growing resistive switching database is accompanied by many detailed mechanisms which often are pure hypotheses. Some of these suggested models can be verified by checking their predictions with the benchmarks of future memory cells. The valence change memory model assumes that the different resistances in ON and OFF states are made by changing the defect density profiles in a sheet near one working electrode during switching. The resulting different READ current densities in ON and OFF states were calculated by using an appropriate simulation model with variation of several important defect and material parameters of the metal/insulator (oxide)/metal thin film stack such as defect density and its profile change in density and thickness, height of the interface barrier, dielectric permittivity, applied voltage. The results were compared to the benchmarks and some memory windows of the varied parameters can be defined: The required ON state READ current density of 105 A/cm2 can only be achieved for barriers smaller than 0.7 eV and defect densities larger than 3 × 1020 cm-3. The required current ratio between ON and OFF states of at least 10 requests defect density reduction of approximately an order of magnitude in a sheet of several nanometers near the working electrode.

Postcombat Outcomes Among Marines with Preexisting Mental Diagnoses

DTIC Science & Technology

2011-12-01

al., 2003), suggesting that prior psychological maladjustment is associated with diminished resilience. Evidence from civilian research suggests that...Servicemembers with preexisting mental health diagnoses were hypothesized to be at increased risk for postcombat psychological maladjustment and

Multi-Drug-Loaded Microcapsules with Controlled Release for Management of Parkinson's Disease.

PubMed

Baek, Jong-Suep; Choo, Chee Chong; Qian, Cheng; Tan, Nguan Soon; Shen, Zexiang; Loo, Say Chye Joachim

2016-07-01

Parkinson's disease (PD) is a progressive disease of the nervous system, and is currently managed through commercial tablets that do not sufficiently enable controlled, sustained release capabilities. It is hypothesized that a drug delivery system that provides controlled and sustained release of PD drugs would afford better management of PD. Hollow microcapsules composed of poly-l-lactide (PLLA) and poly (caprolactone) (PCL) are prepared through a modified double-emulsion technique. They are loaded with three PD drugs, i.e., levodopa (LD), carbidopa (CD), and entacapone (ENT), at a ratio of 4:1:8, similar to commercial PD tablets. LD and CD are localized in both the hollow cavity and PLLA/PCL shell, while ENT is localized in the PLLA/PCL shell. Release kinetics of hydrophobic ENT is observed to be relatively slow as compared to the other hydrophilic drugs. It is further hypothesized that encapsulating ENT into PCL as a surface coating onto these microcapsules can aid in accelerating its release. Now, these spray-coated hollow microcapsules exhibit similar release kinetics, according to Higuchi's rate, for all three drugs. The results suggest that multiple drug encapsulation of LD, CD, and ENT in gastric floating microcapsules could be further developed for in vivo evaluation for the management of PD. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Role of innate and drug-induced dysregulation of brain stress and arousal systems in addiction: Focus on corticotropin-releasing factor, nociceptin/orphanin FQ, and orexin/hypocretin

PubMed Central

Martin-Fardon, Rémi; Zorrilla, Eric P.; Ciccocioppo, Roberto; Weiss, Friedbert

2010-01-01

Stress-like symptoms are an integral part of acute and protracted drug withdrawal, and several lines of evidence have shown that dysregulation of brain stress systems, including the extrahypothalamic corticotropin-releasing factor (CRF) system, following long-term drug use is of major importance in maintaining drug and alcohol addiction. Recently, two other neuropeptide systems have attracted interest, the nociceptin/orphanin FQ (N/OFQ) and orexin/hypocretin (Orx/Hcrt) systems. N/OFQ participates in a wide range of physiological responses, and the hypothalamic Orx/Hcrt system helps regulate several physiological processes, including feeding, energy metabolism, and arousal. Moreover, these two systems have been suggested to participate in psychiatric disorders, including anxiety and drug addiction. Dysregulation of these systems by chronic drug exposure has been hypothesized to play a role in the maintenance of addiction and dependence. Recent evidence demonstrated that interactions between CRF-N/OFQ and CRF-Orx/Hcrt systems may be functionally relevant for the control of stress-related addictive behavior. The present review discusses recent findings that support the hypotheses of the participation and dysregulation of these systems in drug addiction and evaluates the current understanding of interactions among these stress-regulatory peptides. PMID:20026088

Registered report: measuring unconscious deception detection by skin temperature

PubMed Central

van ’ t Veer, Anna E.; Stel, Mariëlle; van Beest, Ilja; Gallucci, Marcello

2014-01-01

Findings from the deception detection literature suggest that although people are not skilled in consciously detecting a liar, they may intuit that something about the person telling a lie is off. In the current proposal, we argue that observing a liar influences the observer’s physiology even though the observer may not be consciously aware of being lied to (i.e., the observers’ direct deception judgment does not accurately differentiate between liars and truth-tellers). To test this hypothesis, participants’ finger temperature will be measured while they watch videos of persons who are either honest or dishonest about their identity. We hypothesize that skin temperature will be lower when observing a liar than when observing a truth-teller. Additionally, we test whether perceiving a liar influences finger skin temperature differently when an individual is, or is not, alerted to the possibility of deceit. We do this by varying participants’ awareness of the fact that they might be lied to. Next to measuring physiological responses to liars and truth-tellers, self-reported direct and indirect veracity judgments (i.e., trustworthiness and liking) of the target persons will be assessed. We hypothesize that indirect veracity judgments will better distinguish between liars and truth-tellers than direct veracity judgments. PMID:24904461

Searching the expressive face: evidence for both the right hemisphere and valence-specific hypotheses.

PubMed

Thomas, Nicole A; Wignall, Sophie J; Loetscher, Tobias; Nicholls, Michael E R

2014-10-01

Quick and accurate judgments of emotional expressivity and attractiveness facilitate social interactions. Eye tracking was used to examine left/right asymmetries across 2 studies. Fixations to each hemiface, and to the eyes and mouth, when judging attractiveness and emotional expressivity were examined. Overall, more fixations occurred on the left hemiface (from the viewer's point of view), even when mirror-reversed, supporting the suggestion that we intuitively know the left hemiface is more expressive. The right side of the mouth was fixated more when judging happiness, whereas the left eye was fixated more for sadness and the left mouth when rating emotional expressivity. The present findings support the notion that the right hemisphere and valence-specific hypotheses are not mutually exclusive. The right hemisphere hypothesis is supported when assessing global facial qualities (i.e., hemiface); however, hemispheric processing differences emerge when exploring the eyes and mouth. The current findings highlight the importance of not only considering how the face is examined more generally, but of also exploring smaller regions of interest to investigate lateral biases. Future research should therefore include analyses of fixations to the hemifaces, as well as to these smaller regions of interest. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Suicidal behavior, negative affect, gender, and self-reported delinquency in college students.

PubMed

Langhinrichsen-Rohling, Jennifer; Arata, Catalina; Bowers, David; O'Brien, Natalie; Morgan, Allen

2004-01-01

The associations among suicidal behavior, negative affect, and delinquency were assessed via an anonymous self-report survey administered to male and female college students ( N = 383). Contrary to our hypothesized results, there were no gender differences in rates of suicidal ideation and attempts. Confirming our hypotheses about gender differences, college men did report significantly more delinquent behavior than college women. College men also scored higher on the suicide-proneness scale, which contained a mixture of death-related, risk-related, and negative self- and health-related items. Furthermore, as predicted, college students with a history of depression, suicide ideation, and/or suicide attempts all reported significantly more delinquent behavior. Self-reported delinquency and current levels of depressive symptomology emerged as significant predictors of suicide-prone behavior for both college men and women, explaining 34% of the variance for women and 17% for men. Levels of engagement in suicide-prone behavior and feelings of depression were elevated in college students with any type of juvenile arrest history. Students with an arrest history were also more likely to have had a diagnosis of depression and to have engaged in suicide ideation in their past. These findings suggest there are complex links between depression, delinquency, and suicidal behavior in college men and women.

Postglacial recolonization in a cold climate specialist in western Europe: patterns of genetic diversity in the adder (Vipera berus) support the central-marginal hypothesis.

PubMed

Ursenbacher, Sylvain; Guillon, Michaël; Cubizolle, Hervé; Dupoué, Andréaz; Blouin-Demers, Gabriel; Lourdais, Olivier

2015-07-01

Understanding the impact of postglacial recolonization on genetic diversity is essential in explaining current patterns of genetic variation. The central-marginal hypothesis (CMH) predicts a reduction in genetic diversity from the core of the distribution to peripheral populations, as well as reduced connectivity between peripheral populations. While the CMH has received considerable empirical support, its broad applicability is still debated and alternative hypotheses predict different spatial patterns of genetic diversity. Using microsatellite markers, we analysed the genetic diversity of the adder (Vipera berus) in western Europe to reconstruct postglacial recolonization. Approximate Bayesian Computation (ABC) analyses suggested a postglacial recolonization from two routes: a western route from the Atlantic Coast up to Belgium and a central route from the Massif Central to the Alps. This cold-adapted species likely used two isolated glacial refugia in southern France, in permafrost-free areas during the last glacial maximum. Adder populations further from putative glacial refugia had lower genetic diversity and reduced connectivity; therefore, our results support the predictions of the CMH. Our study also illustrates the utility of highly variable nuclear markers, such as microsatellites, and ABC to test competing recolonization hypotheses. © 2015 John Wiley & Sons Ltd.

Attentional Bias Modification for Social Anxiety Disorder: What do Patients Think and Why does it Matter?

PubMed

Kuckertz, Jennie M; Schofield, Casey A; Clerkin, Elise M; Primack, Jennifer; Boettcher, Hannah; Weisberg, Risa B; Amir, Nader; Beard, Courtney

2018-05-06

In the past decade, a great deal of research has examined the efficacy and mechanisms of attentional bias modification (ABM), a computerized cognitive training intervention for anxiety and other disorders. However, little research has examined how anxious patients perceive ABM, and it is unclear to what extent perceptions of ABM influence outcome. To examine patient perceptions of ABM across two studies, using a mixed methods approach. In the first study, participants completed a traditional ABM program and received a hand-out with minimal information about the purpose of the task. In the second study, participants completed an adaptive ABM program and were provided with more extensive rationale and instructions for changing attentional biases. A number of themes emerged from qualitative data related to perceived symptom changes and mechanisms of action, acceptability, early perceptions of the program, barriers/facilitators to engagement, and responses to adaptive features. Moreover, quantitative data suggested that patients' perceptions of the program predicted symptom reduction as well as change in attentional bias. Our quantitative data suggest that it may be possible to quickly and inexpensively identify some patients who may benefit from current ABM programs, although our qualitative data suggest that ABM needs major modifications before it will be an acceptable and credible treatment more broadly. Although the current study was limited by sample size and design features of the parent trials from which these data originated, our findings may be useful for guiding hypotheses in future studies examining patient perceptions towards ABM.

Late Middle Eocene primate from Myanmar and the initial anthropoid colonization of Africa.

PubMed

Chaimanee, Yaowalak; Chavasseau, Olivier; Beard, K Christopher; Kyaw, Aung Aung; Soe, Aung Naing; Sein, Chit; Lazzari, Vincent; Marivaux, Laurent; Marandat, Bernard; Swe, Myat; Rugbumrung, Mana; Lwin, Thit; Valentin, Xavier; Zin-Maung-Maung-Thein; Jaeger, Jean-Jacques

2012-06-26

Reconstructing the origin and early evolutionary history of anthropoid primates (monkeys, apes, and humans) is a current focus of paleoprimatology. Although earlier hypotheses frequently supported an African origin for anthropoids, recent discoveries of older and phylogenetically more basal fossils in China and Myanmar indicate that the group originated in Asia. Given the Oligocene-Recent history of African anthropoids, the colonization of Africa by early anthropoids hailing from Asia was a decisive event in primate evolution. However, the fossil record has so far failed to constrain the nature and timing of this pivotal event. Here we describe a fossil primate from the late middle Eocene Pondaung Formation of Myanmar, Afrasia djijidae gen. et sp. nov., that is remarkably similar to, yet dentally more primitive than, the roughly contemporaneous North African anthropoid Afrotarsius. Phylogenetic analysis suggests that Afrasia and Afrotarsius are sister taxa within a basal anthropoid clade designated as the infraorder Eosimiiformes. Current knowledge of eosimiiform relationships and their distribution through space and time suggests that members of this clade dispersed from Asia to Africa sometime during the middle Eocene, shortly before their first appearance in the African fossil record. Crown anthropoids and their nearest fossil relatives do not appear to be specially related to Afrotarsius, suggesting one or more additional episodes of dispersal from Asia to Africa. Hystricognathous rodents, anthracotheres, and possibly other Asian mammal groups seem to have colonized Africa at roughly the same time or shortly after anthropoids gained their first toehold there.

Deaths from bacterial pneumonia during 1918-19 influenza pandemic.

PubMed

Brundage, John F; Shanks, G Dennis

2008-08-01

Deaths during the 1918-19 influenza pandemic have been attributed to a hypervirulent influenza strain. Hence, preparations for the next pandemic focus almost exclusively on vaccine prevention and antiviral treatment for infections with a novel influenza strain. However, we hypothesize that infections with the pandemic strain generally caused self-limited (rarely fatal) illnesses that enabled colonizing strains of bacteria to produce highly lethal pneumonias. This sequential-infection hypothesis is consistent with characteristics of the 1918-19 pandemic, contemporaneous expert opinion, and current knowledge regarding the pathophysiologic effects of influenza viruses and their interactions with respiratory bacteria. This hypothesis suggests opportunities for prevention and treatment during the next pandemic (e.g., with bacterial vaccines and antimicrobial drugs), particularly if a pandemic strain-specific vaccine is unavailable or inaccessible to isolated, crowded, or medically underserved populations.

Effects of Constraints and Consequences on Plan Complexity in Conversations About End-of-Life Care.

PubMed

Russell, Jessica

2015-01-01

The current study assessed the role of health care provider constraints and perceived consequences on plan complexity for conversations with patients about end-of-life care. Meta-goal constraints, perceived consequences associated with conversational engagement and planning theory provides the basis for research questions and hypotheses posed. Findings suggested that while the meta-goals of efficiency and politeness were each recognized as important, providers indicated greater concern for politeness during patient interactions concerning treatment options. Reported constraints had no impact on plan complexity. Perceived consequences of conversational engagement were predominantly positive and concerned the patient. Findings may enhance the understanding of social workers in their educational role regarding the potential training needs of health care team members in palliative care contexts.

Sensemaking Strategies for Ethical Decision-making.

PubMed

Caughron, Jay J; Antes, Alison L; Stenmark, Cheryl K; Thiel, Chaise E; Wang, Xiaoqian; Mumford, Michael D

2011-01-01

The current study uses a sensemaking model and thinking strategies identified in earlier research to examine ethical decision-making. Using a sample of 163 undergraduates, a low fidelity simulation approach is used to study the effects personal involvement (in causing the problem and personal involvement in experiencing the outcomes of the problem) could have on the use of cognitive reasoning strategies that have been shown to promote ethical decision-making. A mediated model is presented which suggests that environmental factors influence reasoning strategies, reasoning strategies influence sensemaking, and sensemaking in turn influences ethical decision-making. Findings were mixed but generally supported the hypothesized model. Interestingly, framing the outcomes of ethically charged situations in terms of more global organizational outcomes rather than personal outcomes was found to promote the use of pro-ethical cognitive reasoning strategies.

An early social engagement intervention for young children with autism and their parents.

PubMed

Vernon, Ty W; Koegel, Robert L; Dauterman, Hayley; Stolen, Kathryn

2012-12-01

The social vulnerabilities associated with young children with autism are recognized as important intervention targets due to their influence on subsequent development. Current research suggests that interventions that combine motivational and social components can create meaningful changes in social functioning. Simultaneously, it is hypothesized that parent delivery of such strategies can invoke increases in these core social behaviors and parent engagement. This study examined the effects of teaching parents to implement a social engagement intervention with their children. The results indicated that the use of this parent-delivered social intervention led to (a) increases in their children's use of eye contact, directed positive affect, and verbal initiations, (b) increases in parent positive affect and synchronous engagement, and (c) generalized increases in parent and child behaviors.

Epidemiological evidence of carcinogenicity of chlorinated organics in drinking water.

PubMed

Cantor, K P

1982-12-01

Concern has recently been voiced over possible chronic toxicity associated with chlorination of public drinking water supplies in the United States. This paper reviews the available evidence and the studies underway to further evaluate hypothesized associations between cancer risk and byproducts of chlorination. Preliminary data from measures of halogenated volatiles and personal exposure histories from respondents in a large epidemiologic study of bladder cancer are presented. These data support the use in epidemiologic studies of categorical measures of exposure and suggest that results from completed case-control studies, based on death certificates, may have underestimated the true risk of exposure to chlorination by-products. The current generation of studies which use a case-control interview design offer many advantages over earlier efforts to evaluate this issue.

Epidemiological evidence of carcinogenicity of chlorinated organics in drinking water.

PubMed Central

Cantor, K P

1982-01-01

Concern has recently been voiced over possible chronic toxicity associated with chlorination of public drinking water supplies in the United States. This paper reviews the available evidence and the studies underway to further evaluate hypothesized associations between cancer risk and byproducts of chlorination. Preliminary data from measures of halogenated volatiles and personal exposure histories from respondents in a large epidemiologic study of bladder cancer are presented. These data support the use in epidemiologic studies of categorical measures of exposure and suggest that results from completed case-control studies, based on death certificates, may have underestimated the true risk of exposure to chlorination by-products. The current generation of studies which use a case-control interview design offer many advantages over earlier efforts to evaluate this issue. PMID:6759108

An Early Social Engagement Intervention for Young Children with Autism and their Parents

PubMed Central

Vernon, Ty W.; Koegel, Robert L.; Dauterman, Hayley; Stolen, Kathryn

2013-01-01

The social vulnerabilities associated with young children with autism are recognized as important intervention targets due to their influence on subsequent development. Current research suggests that interventions that combine motivational and social components can create meaningful changes in social functioning. Simultaneously, it is hypothesized that parent delivery of such strategies can invoke increases in these core social behaviors and parent engagement. This study examined the effects of teaching parents to implement a social engagement intervention with their children. The results indicated that the use of this parent-delivered social intervention led to (a) increases in their children's use of eye contact, directed positive affect, and verbal initiations, (b) increases in parent positive affect and synchronous engagement, and (c) generalized increases in parent and child behaviors. PMID:22527708

Neuroscience cannot answer these questions: a response to G. and R. Murrow's essay hypothesizing a link between dehumanization, human rights abuses and public policy

PubMed Central

Hoffman, Morris B.

2015-01-01

The Murrows' paper, ‘A hypothetical link between dehumanization and human rights abuses’, in which they propose that neuroscience may answer some difficult public policy questions, including questions about the First Amendment, is an unfortunate foray into law and public policy unjustified by the current state of neuroscience. Neuroscientific insights may one day have important implications for the law, and for some of the folk psychological assumptions embedded in the law, but they will never change the words of the written Constitution, or answer difficult policy questions in the interstices of those words. Suggesting that neuroscience can today inform these questions does a disservice to science, law and the complexity of the human condition. PMID:27774237

Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba.

PubMed

Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

2011-06-23

Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids-a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians.

Sensemaking Strategies for Ethical Decision-making

PubMed Central

Caughron, Jay J.; Antes, Alison L.; Stenmark, Cheryl K.; Thiel, Chaise E.; Wang, Xiaoqian; Mumford, Michael D.

2015-01-01

The current study uses a sensemaking model and thinking strategies identified in earlier research to examine ethical decision-making. Using a sample of 163 undergraduates, a low fidelity simulation approach is used to study the effects personal involvement (in causing the problem and personal involvement in experiencing the outcomes of the problem) could have on the use of cognitive reasoning strategies that have been shown to promote ethical decision-making. A mediated model is presented which suggests that environmental factors influence reasoning strategies, reasoning strategies influence sensemaking, and sensemaking in turn influences ethical decision-making. Findings were mixed but generally supported the hypothesized model. Interestingly, framing the outcomes of ethically charged situations in terms of more global organizational outcomes rather than personal outcomes was found to promote the use of pro-ethical cognitive reasoning strategies. PMID:26257505

The evolution of the genetic code: Impasses and challenges.

PubMed

Kun, Ádám; Radványi, Ádám

2018-02-01

The origin of the genetic code and translation is a "notoriously difficult problem". In this survey we present a list of questions that a full theory of the genetic code needs to answer. We assess the leading hypotheses according to these criteria. The stereochemical, the coding coenzyme handle, the coevolution, the four-column theory, the error minimization and the frozen accident hypotheses are discussed. The integration of these hypotheses can account for the origin of the genetic code. But experiments are badly needed. Thus we suggest a host of experiments that could (in)validate some of the models. We focus especially on the coding coenzyme handle hypothesis (CCH). The CCH suggests that amino acids attached to RNA handles enhanced catalytic activities of ribozymes. Alternatively, amino acids without handles or with a handle consisting of a single adenine, like in contemporary coenzymes could have been employed. All three scenarios can be tested in in vitro compartmentalized systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Alternating gender incongruity: a new neuropsychiatric syndrome providing insight into the dynamic plasticity of brain-sex.

PubMed

Case, Laura K; Ramachandran, Vilayanur S

2012-05-01

Between the two extreme ends of human sexuality - male and female - lie a poorly understood and poorly studied spectrum of ambiguously defined sexual identities that are very much a part of the human condition but defy rigid classification. "Bigender" is a recently formed sub-category of transgenderism, describing individuals who experience a blending or alternation of gender states. While recognized nominally by the APA, no scientific work to our knowledge has addressed this fascinating condition, or proposed any physiological basis for it. In addition, the alternation aspect has not been proposed as a nosological entity distinct from blending. We present descriptive data suggesting that many bigender individuals experience an involuntary switching of gender states without any amnesia for either state. In addition, similar to transsexual individuals, the majority of bigender individuals experience phantom breasts or genitalia corresponding to the non-biologic gender when they are in a trans-gender state. Finally, our survey found decreased lateralization of handedness in the bigender community. These observations suggest a biologic basis of bigenderism and lead us to propose a novel gender condition, "alternating gender incongruity" (AGI). We hypothesize that AGI may be related to an unusual degree or depth of hemispheric switching and corresponding callosal suppression of sex appropriate body maps in parietal cortex- possibly the superior parietal lobule- and its reciprocal connections with the insula and hypothalamus. This is based on two lines of reasoning. First, bigender individuals in our survey sample reported an elevated rate of bipolar disorder, which has been linked to slowed hemispheric switching. We hypothesize that tracking the nasal cycle, rate of binocular rivalry, and other markers of hemispheric switching will reveal a physiological basis for AGI individuals' subjective reports of gender switches. Switching may also trigger hormonal cascades, which we are currently exploring. Second, we base our hypotheses on ancient and modern associations between the left and right hemispheres and the male and female genders. By providing a case of sharp brain-sex shifts within individuals, we believe that the study of AGI could prove illuminating to scientific understanding of gender, body representation, and the nature of self. Copyright © 2012 Elsevier Ltd. All rights reserved.

A survey of etiologic hypotheses among testicular cancer researchers.

PubMed

Stang, A; Trabert, B; Rusner, C; Poole, C; Almstrup, K; Rajpert-De Meyts, E; McGlynn, K A

2015-01-01

Basic research results can provide new ideas and hypotheses to be examined in epidemiological studies. We conducted a survey among testicular cancer researchers on hypotheses concerning the etiology of this malignancy. All researchers on the mailing list of Copenhagen Testis Cancer Workshops and corresponding authors of PubMed-indexed articles identified by the search term 'testicular cancer' and published within 10 years (in total 2750 recipients) were invited to respond to an e-mail-based survey. Participants of the 8th Copenhagen Testis Cancer Workshop in May 2014 were subsequently asked to rate the plausibility of the suggested etiologic hypotheses on a scale of 1 (very implausible) to 10 (very plausible). This report describes the methodology of the survey, the score distributions by individual hypotheses, hypothesis group, and the participants' major research fields, and discuss the hypotheses that scored as most plausible. We also present plans for improving the survey that may be repeated at a next international meeting of experts in testicular cancer. Overall 52 of 99 (53%) registered participants of the 8th Copenhagen Testis Cancer Workshop submitted the plausibility rating form. Fourteen of 27 hypotheses were related to exposures during pregnancy. Hypotheses with the highest mean plausibility ratings were either related to pre-natal exposures or exposures that might have an effect during pregnancy and in post-natal life. The results of the survey may be helpful for triggering more specific etiologic hypotheses that include factors related to endocrine disruption, DNA damage, inflammation, and nutrition during pregnancy. The survey results may stimulate a multidisciplinary discussion about new etiologic hypotheses of testicular cancer. Published 2014. This article is a U. S. Government work and is in the public domain in the USA.

A review of empirical evidence on different uncanny valley hypotheses: support for perceptual mismatch as one road to the valley of eeriness

PubMed Central

Kätsyri, Jari; Förger, Klaus; Mäkäräinen, Meeri; Takala, Tapio

2015-01-01

The uncanny valley hypothesis, proposed already in the 1970s, suggests that almost but not fully humanlike artificial characters will trigger a profound sense of unease. This hypothesis has become widely acknowledged both in the popular media and scientific research. Surprisingly, empirical evidence for the hypothesis has remained inconsistent. In the present article, we reinterpret the original uncanny valley hypothesis and review empirical evidence for different theoretically motivated uncanny valley hypotheses. The uncanny valley could be understood as the naïve claim that any kind of human-likeness manipulation will lead to experienced negative affinity at close-to-realistic levels. More recent hypotheses have suggested that the uncanny valley would be caused by artificial–human categorization difficulty or by a perceptual mismatch between artificial and human features. Original formulation also suggested that movement would modulate the uncanny valley. The reviewed empirical literature failed to provide consistent support for the naïve uncanny valley hypothesis or the modulatory effects of movement. Results on the categorization difficulty hypothesis were still too scarce to allow drawing firm conclusions. In contrast, good support was found for the perceptual mismatch hypothesis. Taken together, the present review findings suggest that the uncanny valley exists only under specific conditions. More research is still needed to pinpoint the exact conditions under which the uncanny valley phenomenon manifests itself. PMID:25914661

Predation on an Upper Trophic Marine Predator, the Steller Sea Lion: Evaluating High Juvenile Mortality in a Density Dependent Conceptual Framework

PubMed Central

Horning, Markus; Mellish, Jo-Ann E.

2012-01-01

The endangered western stock of the Steller sea lion (Eumetopias jubatus) – the largest of the eared seals – has declined by 80% from population levels encountered four decades ago. Current overall trends from the Gulf of Alaska to the Aleutian Islands appear neutral with strong regional heterogeneities. A published inferential model has been used to hypothesize a continuous decline in natality and depressed juvenile survival during the height of the decline in the mid-late 1980's, followed by the recent recovery of juvenile survival to pre-decline rates. However, these hypotheses have not been tested by direct means, and causes underlying past and present population trajectories remain unresolved and controversial. We determined post-weaning juvenile survival and causes of mortality using data received post-mortem via satellite from telemetry transmitters implanted into 36 juvenile Steller sea lions from 2005 through 2011. Data show high post-weaning mortality by predation in the eastern Gulf of Alaska region. To evaluate the impact of such high levels of predation, we developed a conceptual framework to integrate density dependent with density independent effects on vital rates and population trajectories. Our data and model do not support the hypothesized recent recovery of juvenile survival rates and reduced natality. Instead, our data demonstrate continued low juvenile survival in the Prince William Sound and Kenai Fjords region of the Gulf of Alaska. Our results on contemporary predation rates combined with the density dependent conceptual framework suggest predation on juvenile sea lions as the largest impediment to recovery of the species in the eastern Gulf of Alaska region. The framework also highlights the necessity for demographic models based on age-structured census data to incorporate the differential impact of predation on multiple vital rates. PMID:22272296

Addressing the translational dilemma: dynamic knowledge representation of inflammation using agent-based modeling.

PubMed

An, Gary; Christley, Scott

2012-01-01

Given the panoply of system-level diseases that result from disordered inflammation, such as sepsis, atherosclerosis, cancer, and autoimmune disorders, understanding and characterizing the inflammatory response is a key target of biomedical research. Untangling the complex behavioral configurations associated with a process as ubiquitous as inflammation represents a prototype of the translational dilemma: the ability to translate mechanistic knowledge into effective therapeutics. A critical failure point in the current research environment is a throughput bottleneck at the level of evaluating hypotheses of mechanistic causality; these hypotheses represent the key step toward the application of knowledge for therapy development and design. Addressing the translational dilemma will require utilizing the ever-increasing power of computers and computational modeling to increase the efficiency of the scientific method in the identification and evaluation of hypotheses of mechanistic causality. More specifically, development needs to focus on facilitating the ability of non-computer trained biomedical researchers to utilize and instantiate their knowledge in dynamic computational models. This is termed "dynamic knowledge representation." Agent-based modeling is an object-oriented, discrete-event, rule-based simulation method that is well suited for biomedical dynamic knowledge representation. Agent-based modeling has been used in the study of inflammation at multiple scales. The ability of agent-based modeling to encompass multiple scales of biological process as well as spatial considerations, coupled with an intuitive modeling paradigm, suggest that this modeling framework is well suited for addressing the translational dilemma. This review describes agent-based modeling, gives examples of its applications in the study of inflammation, and introduces a proposed general expansion of the use of modeling and simulation to augment the generation and evaluation of knowledge by the biomedical research community at large.

FORUM: Dynamics and Causation of Environmental Equity, Locally Unwanted Land Uses, and Neighborhood Changes

PubMed

Liu

1997-09-01

/ Why are some environmental risks distributed disproportionately in the neighborhoods of the minorities and the poor? A hypothesis was proposed in a recent study that market dynamics contributed to the current environmental inequity. That is, locally unwanted land uses (LULUs) make the host communities home to more poor people and people of color. This hypothesis was allegedly supported by a Houston case study, whereby its author analyzed the postsiting changes of the socioeconomic characteristics of the neighborhoods surrounding solid waste facilities. I argue that such an analysis of postsiting changes alone is insufficient to test the causation hypothesis. Instead, I propose a conceptual framework for analysis of environmental equity dynamics and causation. I suggest that the presiting neighborhood dynamics and the characteristics of control neighborhoods be analyzed as the first test for the causation hypothesis. Furthermore, I present theories of neighborhood change and then examine alternative hypotheses that these theories offer for explaining neighborhood changes and for the roles of LULUs in neighborhood changes. These alternative hypotheses should be examined when analyzing the relationship between LULUs and neighborhood changes in a metropolitan area. Using this framework of analysis, I revisited the Houston case. First, I found no evidence that provided support for the hypothesis that the presence of LULUs made the neighborhoods home to more blacks and poor people, contrary to the conclusion made by the previous study. Second, I examined alternative hypotheses for explaining neighborhood changes-invasion-succession, other push forces, and neighborhood life-cycle; the former two might offer better explanation.KEY WORDS: Environmental equity and justice; Locally unwanted lane uses; Siting; Market dynamics; Invasion-succession; Neighborhood changes

Differential T cell response against BK virus regulatory and structural antigens: A viral dynamics modelling approach.

PubMed

Blazquez-Navarro, Arturo; Schachtner, Thomas; Stervbo, Ulrik; Sefrin, Anett; Stein, Maik; Westhoff, Timm H; Reinke, Petra; Klipp, Edda; Babel, Nina; Neumann, Avidan U; Or-Guil, Michal

2018-05-01

BK virus (BKV) associated nephropathy affects 1-10% of kidney transplant recipients, leading to graft failure in about 50% of cases. Immune responses against different BKV antigens have been shown to have a prognostic value for disease development. Data currently suggest that the structural antigens and regulatory antigens of BKV might each trigger a different mode of action of the immune response. To study the influence of different modes of action of the cellular immune response on BKV clearance dynamics, we have analysed the kinetics of BKV plasma load and anti-BKV T cell response (Elispot) in six patients with BKV associated nephropathy using ODE modelling. The results show that only a small number of hypotheses on the mode of action are compatible with the empirical data. The hypothesis with the highest empirical support is that structural antigens trigger blocking of virus production from infected cells, whereas regulatory antigens trigger an acceleration of death of infected cells. These differential modes of action could be important for our understanding of BKV resolution, as according to the hypothesis, only regulatory antigens would trigger a fast and continuous clearance of the viral load. Other hypotheses showed a lower degree of empirical support, but could potentially explain the clearing mechanisms of individual patients. Our results highlight the heterogeneity of the dynamics, including the delay between immune response against structural versus regulatory antigens, and its relevance for BKV clearance. Our modelling approach is the first that studies the process of BKV clearance by bringing together viral and immune kinetics and can provide a framework for personalised hypotheses generation on the interrelations between cellular immunity and viral dynamics.

Social Goals and Grade as Moderators of Social Normative Influences on Adolescent Alcohol Use

PubMed Central

Meisel, Samuel N.; Colder, Craig R.

2016-01-01

Background The literature distinguishes two types of social normative influences on adolescent alcohol use, descriptive norms (perceived peer alcohol use) and injunctive norms (perceived approval of drinking). Although theoretical formulations suggest variability in the salience and influence of descriptive and injunctive norms, little is understood regarding for whom and when social norms influence adolescent drinking. Strong agentic and communal social goals were hypothesized to moderate the influence of descriptive and injunctive norms on early adolescent alcohol use, respectively. Developmental changes were also expected, such that these moderating effects were expected to get stronger at later grades. Methods This longitudinal study included 387 adolescents and 4 annual assessments (spanning 6th to 10th grade). Participants completed questionnaire measures of social goals, social norms, and alcohol use at each wave. Results Multilevel logistic regressions were used to test prospective associations. As hypothesized, descriptive norms predicted increases in the probability of alcohol use for adolescents with strong agentic goals, but only in later grades. Injunctive norms were associated with increases in the probability of drinking for adolescents with low communal goals at earlier grades, whereas injunctive norms were associated with an increased probability of drinking for adolescents with either low or high communal goals at later grades. Although not hypothesized, descriptive norms predicted increases in the probability of drinking for adolescents high in communal goals in earlier grades whereas descriptive norms predicted drinking for adolescents characterized by low communal goals in later grades. Conclusions The current study highlights the importance of social goals when considering social normative influences on alcohol use in early and middle adolescence. These findings have implications for whom and when normative feedback interventions might be most effective during this developmental period. PMID:26554341

Effect of Polya Problem-Solving Model on Senior Secondary School Students' Performance in Current Electricity

ERIC Educational Resources Information Center

Olaniyan, Ademola Olatide; Omosewo, Esther O.; Nwankwo, Levi I.

2015-01-01

This study was designed to investigate the Effect of Polya Problem-Solving Model on Senior School Students' Performance in Current Electricity. It was a quasi experimental study of non- randomized, non equivalent pre-test post-test control group design. Three research questions were answered and corresponding three research hypotheses were tested…

A critical assessment of the "sterile womb" and "in utero colonization" hypotheses: implications for research on the pioneer infant microbiome.

PubMed

Perez-Muñoz, Maria Elisa; Arrieta, Marie-Claire; Ramer-Tait, Amanda E; Walter, Jens

2017-04-28

After more than a century of active research, the notion that the human fetal environment is sterile and that the neonate's microbiome is acquired during and after birth was an accepted dogma. However, recent studies using molecular techniques suggest bacterial communities in the placenta, amniotic fluid, and meconium from healthy pregnancies. These findings have led many scientists to challenge the "sterile womb paradigm" and propose that microbiome acquisition instead begins in utero, an idea that would fundamentally change our understanding of gut microbiota acquisition and its role in human development. In this review, we provide a critical assessment of the evidence supporting these two opposing hypotheses, specifically as it relates to (i) anatomical, immunological, and physiological characteristics of the placenta and fetus; (ii) the research methods currently used to study microbial populations in the intrauterine environment; (iii) the fecal microbiome during the first days of life; and (iv) the generation of axenic animals and humans. Based on this analysis, we argue that the evidence in support of the "in utero colonization hypothesis" is extremely weak as it is founded almost entirely on studies that (i) used molecular approaches with an insufficient detection limit to study "low-biomass" microbial populations, (ii) lacked appropriate controls for contamination, and (iii) failed to provide evidence of bacterial viability. Most importantly, the ability to reliably derive axenic animals via cesarean sections strongly supports sterility of the fetal environment in mammals. We conclude that current scientific evidence does not support the existence of microbiomes within the healthy fetal milieu, which has implications for the development of clinical practices that prevent microbiome perturbations after birth and the establishment of future research priorities.

A genetics-based approach confirms immune associations with life history across multiple populations of an aquatic vertebrate (Gasterosteus aculeatus).

PubMed

Whiting, James R; Magalhaes, Isabel S; Singkam, Abdul R; Robertson, Shaun; D'Agostino, Daniele; Bradley, Janette E; MacColl, Andrew D C

2018-06-20

Understanding how wild immune variation covaries with other traits can reveal how costs and trade-offs shape immune evolution in the wild. Divergent life history strategies may increase or alleviate immune costs, helping shape immune variation in a consistent, testable way. Contrasting hypotheses suggest that shorter life histories may alleviate costs by offsetting them against increased mortality; or increase the effect of costs if immune responses are traded off against development or reproduction. We investigated the evolutionary relationship between life history and immune responses within an island radiation of three-spined stickleback, with discrete populations of varying life histories and parasitism. We sampled two short-lived, two long-lived and an anadromous population using qPCR to quantify current immune profile and RAD-seq data to study the distribution of immune variants within our assay genes and across the genome. Short-lived populations exhibited significantly increased expression of all assay genes, which was accompanied by a strong association with population-level variation in local alleles and divergence in a gene that may be involved in complement pathways. In addition, divergence around the eda gene in anadromous fish is likely associated with increased inflammation. A wider analysis of 15 populations across the island revealed that immune genes across the genome show evidence of having diverged alongside life history strategies. Parasitism and reproductive investment were also important sources of variation for expression, highlighting the caution required when assaying immune responses in the wild. These results provide strong, gene-based support for current hypotheses linking life history and immune variation across multiple populations of a vertebrate model. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The relationship between childhood trauma and the severity of adulthood depression and anxiety symptoms in a clinical sample: The mediating role of cognitive emotion regulation strategies.

PubMed

Huh, Hyu Jung; Kim, Kyung Hee; Lee, Hee-Kyung; Chae, Jeong-Ho

2017-04-15

Childhood trauma is an important factor in adverse mental health outcomes, including depression and anxiety. The purpose of the present study was to evaluate a hypothesized model describing a pathway of childhood trauma and its influence on psychiatric symptoms in patients with depressive disorder. In this model, childhood trauma was positively associated with current depression and anxiety symptoms, which were mediated by a cognitive emotional regulation strategy. Patients with depressive disorder (n=585, 266 men, 316 women) completed the Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Childhood Trauma Questionnaire (CTQ), and Cognitive Emotion Regulation Questionnaire (CERQ). We divided the cognitive emotion regulation strategies into adaptive and maladaptive strategies using a CERQ subscore. We employed structural equation modeling (SEM) and simple/multiple mediation analyses. The indirect effect of maladaptive strategies was significant in the relationship between overall childhood trauma and depression/anxiety severity, whereas the mediation effect of adaptive strategies was limited to depressive symptoms. With respect to specific types of trauma, maladaptive strategies mediated the association between emotional abuse and current depression/anxiety, while the mediation effect of adaptive strategies was limited to emotional neglect. This study's cross-sectional design does not allow establishment of causal relationships. Childhood trauma recall bias may be possible. These findings support the hypothesized model in which childhood trauma is associated with adulthood depression/anxiety symptoms in clinical samples, and mediated by emotion regulation strategies. These results suggest that cognitive emotion dysregulation is an important factor affecting depression/anxiety symptoms in patients with childhood trauma. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid evolution of phenology during range expansion with recent climate change.

PubMed

Lustenhouwer, Nicky; Wilschut, Rutger A; Williams, Jennifer L; van der Putten, Wim H; Levine, Jonathan M

2018-02-01

Although climate warming is expected to make habitat beyond species' current cold range edge suitable for future colonization, this new habitat may present an array of biotic or abiotic conditions not experienced within the current range. Species' ability to shift their range with climate change may therefore depend on how populations evolve in response to such novel environmental conditions. However, due to the recent nature of thus far observed range expansions, the role of rapid adaptation during climate change migration is only beginning to be understood. Here, we evaluated evolution during the recent native range expansion of the annual plant Dittrichia graveolens, which is spreading northward in Europe from the Mediterranean region. We examined genetically based differentiation between core and edge populations in their phenology, a trait that is likely under selection with shorter growing seasons and greater seasonality at northern latitudes. In parallel common garden experiments at range edges in Switzerland and the Netherlands, we grew plants from Dutch, Swiss, and central and southern French populations. Population genetic analysis following RAD-sequencing of these populations supported the hypothesized central France origins of the Swiss and Dutch range edge populations. We found that in both common gardens, northern plants flowered up to 4 weeks earlier than southern plants. This differentiation in phenology extended from the core of the range to the Netherlands, a region only reached from central France over approximately the last 50 years. Fitness decreased as plants flowered later, supporting the hypothesized benefits of earlier flowering at the range edge. Our results suggest that native range expanding populations can rapidly adapt to novel environmental conditions in the expanded range, potentially promoting their ability to spread. © 2017 John Wiley & Sons Ltd.

White Matter Correlates of Neuropsychological Dysfunction in Systemic Lupus Erythematosus

PubMed Central

Jung, Rex E.; Chavez, Robert S.; Flores, Ranee A.; Qualls, Clifford; Sibbitt, Wilmer L.; Roldan, Carlos A.

2012-01-01

Patients diagnosed with Systemic Lupus Erythematosus have similar levels of neuropsychological dysfunction (i.e., 20–50%) as those with Neuropsychiatric Systemic Lupus Erythematosus (NPSLE). We hypothesized a gradient between cognition and white matter integrity, such that strongest brain-behavior relationships would emerge in NPSLE, intermediate in non-NPSLE, and minimal in controls. We studied thirty-one patients (16 non-NPSLE; 15 NPSLE), ranging in age from 18 to 59 years old (100% female), and eighteen age and gender matched healthy controls. DTI examinations were performed on a 1.5T scanner. A broad neuropsychological battery was administered, tapping attention, memory, processing speed, and executive functioning. The Total z-score consisted of the combined sum of all neuropsychological measures. In control subjects, we found no significant FA-Total z-score correlations. NPSLE, non-NPSLE, and control subjects differed significantly in terms of Total z-score (NPSLE = −2.25+/−1.77, non-NPSLE = −1.22+/−1.03, Controls = −0.10+/−.57; F = 13.2, p<.001). In non-NPSLE subjects, FA within the right external capsule was significantly correlated with Total z-score. In NPSLE subjects, the largest FA-Total z-score clusters were observed within the left anterior thalamic radiation and right superior longitudinal fasciculus. In subsequent analyses the largest number of significant voxels linked FA with the Processing Speed z-score in NPSLE. The current results reflect objective white matter correlates of neuropsychological dysfunction in both NPSLE and (to a lesser degree) in non-NPSLE. non-NPSLE and NPSLE subjects did not differ significantly in terms of depression, as measured by the GDI; thus, previous hypotheses suggesting moderating effects of depression upon neuropsychological performance do not impact the current FA results. PMID:22291880

Using the IEA Data Bank for Research in Reading and Response to Literature.

ERIC Educational Resources Information Center

Purves, Alan C.

1978-01-01

Summarizes the findings of the International Association for the Evaluation of Educational Achievement (IEA) pertinent to reading and response to literature and suggests ways the IEA data bank can stimulate research by suggesting hypotheses. (DD)

The association of parent's outcome expectations for child TV viewing with parenting practices and child TV viewing: an examination using path analysis.

PubMed

Johnson, Lauren; Chen, Tzu-An; Hughes, Sheryl O; O'Connor, Teresia M

2015-05-28

Television (TV) viewing has been associated with many undesirable outcomes for children, such as increased risk of obesity, but TV viewing can also have benefits. Although restrictive parenting practices are effective in reducing children's TV viewing, not all parents use them and it is currently unclear why. The current study examined parenting practices related to TV viewing in the context of social- cognitive theory. Specifically, we hypothesized that positive and negative Parental Outcome Expectations for child's TV Viewing (POETV) would be associated with social co-viewing and restrictive parenting practices, and that POETV and parenting practices influence the amount of TV viewed by child. Data were collected from an internet survey of 287 multi-ethnic parents and their 6-12 year old children on participants' sociodemographic information, parenting practices related to TV use, POETV, and parent and child TV viewing. Path analysis was used to examine the relationship amongst variables in separate models for weekday and weekend TV viewing. controlling for child age, household education, and parental TV viewing. The results provided partial support for the hypotheses, with notable differences between weekday and weekend viewing. The models explained 13.6% and 23.4% of the variance in children's TV viewing on weekdays and weekends respectively. Neither positive nor negative POETV were associated with restrictive TV parenting in either model. One subscale each from positive and negative POETV were associated with social co-viewing parenting on both weekends and weekdays in the expected direction. Restrictive parenting practices were directly negatively associated with children's TV viewing on weekdays, but not weekends. Social co-viewing parenting was directly positively associated with children's TV viewing on weekends, but not weekdays. The strongest influence on children's TV viewing was having a TV in the child's bedroom. Negative POETV was weakly associated with having a TV in the child's room. These findings suggest that POETV and parenting may have a greater impact on weekend TV viewing, when children tend to watch more TV, than weekday. The models suggest that POETV, parenting and especially removing the TV from children's rooms may be promising targets for interventions.

Dreaming and waking experiences in schizophrenia: how should the (dis)continuity hypotheses be approached empirically?

PubMed

Noreika, Valdas

2011-06-01

A number of differences between the dreams of schizophrenia patients and those of healthy participants have been linked to changes in waking life that schizophrenia may cause. This way, the "continuity hypothesis" has become a standard way to relate dreaming and waking experiences in schizophrenia. Nevertheless, some of the findings in dream literature are not compatible with the continuity hypothesis and suggest some other ways how dream content and waking experiences could interact. Conceptually, the continuity hypothesis could be sharpened into the "waking-to-dreaming" and the "dreaming-to-waking" hypotheses, whereas a less explored type of "discontinuity" could embrace the "compensated waking" and the "compensated dreaming" hypotheses. A careful consideration and empirical testing of each of those hypotheses may reveal a multiplicity of the ways how dreaming and waking life interact in schizophrenia. Copyright © 2010 Elsevier Inc. All rights reserved.

A role for neurotransmission and neurodevelopment in attention-deficit/hyperactivity disorder

PubMed Central

2009-01-01

Attention-deficit/hyperactivity disorder (ADHD) has a moderate to high genetic component, probably due to many genes with small effects. Several susceptibility genes have been suggested on the basis of hypotheses that catecholaminergic pathways in the brain are responsible for ADHD. However, many negative association findings have been reported, indicating a limited success for investigations using this approach. The results from genome-wide association studies have suggested that genes related to general brain functions rather than specific aspects of the disorder may contribute to its development. Plausible biological hypotheses linked to neurotransmission and neurodevelopment in general and common to different psychiatric conditions need to be considered when defining candidate genes for ADHD association studies. PMID:19930624

Pathogenesis of Bacterial Vaginosis: Discussion of Current Hypotheses

PubMed Central

Muzny, Christina A.; Schwebke, Jane R.

2016-01-01

In April 2015, the Division of Microbiology and Infectious Diseases of the National Institute of Allergy and Infectious Diseases hosted an experts technical consultation on bacterial vaginosis (BV), where data regarding controversies over the pathogenesis of BV were discussed. The discussion on the epidemiology and pathogenesis of BV is presented here, and several hypotheses on its pathogenesis are critiqued. Rigorous hypothesis-driven studies are needed to ultimately determine the cause of BV. This information is vital for the prevention and control of this important infection and its adverse public health consequences. PMID:27449868

Research, Practice, and Policy Perspectives on Issues of Children without Permanent Parental Care

PubMed Central

McCall, Robert B.

2013-01-01

This chapter presents conclusions, trends, conceptual analyses, hypotheses, and speculations regarding some fundamental issues of research, practice, and policy that are largely unsettled or controversial. As such, the chapter is not a summary of Chapters 1-8, but rather contains interpretations and opinions of the author intended to elevate the priority of certain issues, suggest hypotheses to be studied, and propose practice and policy steps to be considered. PMID:25018566

Is improved lane keeping during cognitive load caused by increased physical arousal or gaze concentration toward the road center?

PubMed

Li, Penghui; Markkula, Gustav; Li, Yibing; Merat, Natasha

2018-08-01

Driver distraction is one of the main causes of motor-vehicle accidents. However, the impact on traffic safety of tasks that impose cognitive (non-visual) distraction remains debated. One particularly intriguing finding is that cognitive load seems to improve lane keeping performance, most often quantified as reduced standard deviation of lateral position (SDLP). The main competing hypotheses, supported by current empirical evidence, suggest that cognitive load improves lane keeping via either increased physical arousal, or higher gaze concentration toward the road center, but views are mixed regarding if, and how, these possible mediators influence lane keeping performance. Hence, a simulator study was conducted, with participants driving on a straight city road section whilst completing a cognitive task at different levels of difficulty. In line with previous studies, cognitive load led to increased physical arousal, higher gaze concentration toward the road center, and higher levels of micro-steering activity, accompanied by improved lane keeping performance. More importantly, during the high cognitive task, both physical arousal and gaze concentration changed earlier in time than micro-steering activity, which in turn changed earlier than lane keeping performance. In addition, our results did not show a significant correlation between gaze concentration and physical arousal on the level of individual task recordings. Based on these findings, various multilevel models for micro-steering activity and lane keeping performance were conducted and compared, and the results suggest that all of the mechanisms proposed by existing hypotheses could be simultaneously involved. In other words, it is suggested that cognitive load leads to: (i) an increase in arousal, causing increased micro-steering activity, which in turn improves lane keeping performance, and (ii) an increase in gaze concentration, causing lane keeping improvement through both (a) further increased micro-steering activity and (b) a tendency to steer toward the gaze target. Copyright © 2018 Elsevier Ltd. All rights reserved.

Body odour preferences in men and women: do they aim for specific MHC combinations or simply heterozygosity?

PubMed Central

Wedekind, C; Füri, S

1997-01-01

The major histocompatibility complex (MHC) is an immunologically important group of genes that appears to be under natural as well as sexual selection. Several hypotheses suggest that certain MHC-allele combinations (usually heterozygous ones) are superior under selective pressure by pathogens. This could influence mate choice in a way that preferences function to create MHC-heterozygous offspring, or that they function to create specific allele combinations that are beneficial under the current environmental conditions through their complementary or epistatic effects. To test these hypotheses, we asked 121 men and women to score the odours of six T-shirts, worn by two women and four men. Their scorings of pleasantness correlated negatively with the degree of MHC similarity between smeller and T-shirt-wearer in men and women who were not using the contraceptive pill (but not in Pill-users). Depending on the T-shirt-wearer, the amount of variance in the scorings of odour pleasantness that was explained by the degree of MHC similarity (r2) varied between nearly 0 and 23%. There was no apparent effect of gender in this correlation: the highest r2 was actually reached with one of the male odours sniffed by male smellers. Men and women who were reminded of their own mate/ex-mate when sniffing a T-shirt had significantly fewer MHC-alleles in common with this T-shirt-wearer than expected by chance. This suggests that the MHC or linked genes influence human mate choice. We found no significant effect when we tested for an influence of the MHC on odour preferences after the degree of similarity between T-shirt-wearer and smeller was statistically controlled for. This suggests that in our study populations the MHC influences body odour preferences mainly, if not exclusively, by the degree of similarity or dissimilarity. The observed preferences would increase heterozygosity in the progeny. They do not seem to aim for more specific MHC combinations. PMID:9364787

Future orientation and suicide ideation and attempts in depressed adults ages 50 and over.

PubMed

Hirsch, Jameson K; Duberstein, Paul R; Conner, Kenneth R; Heisel, Marnin J; Beckman, Anthony; Franus, Nathan; Conwell, Yeates

2006-09-01

The objective of this study was to test the hypothesis that future orientation is associated with lower levels of suicide ideation and lower likelihood of suicide attempt in a sample of patients in treatment for major depression. Two hundred two participants (116 female, 57%) ages 50-88 years were recruited from inpatient and outpatient settings. All were diagnosed with major depression using a structured diagnostic interview. Suicide ideation was assessed with the Scale for Suicide Ideation (both current and worst point ratings), and a measure of future orientation was created to assess future expectancies. The authors predicted that greater future orientation would be associated with less current and worst point suicide ideation, and would distinguish current and lifetime suicide attempters from nonattempters. Hypotheses were tested using multivariate logistic regression and linear regression analyses that accounted for age, gender, hopelessness, and depression. As hypothesized, higher future orientation scores were associated with lower current suicidal ideation, less intense suicidal ideation at its worst point, and lower probability of a history of attempted suicide after accounting for covariates. Future orientation was not associated with current attempt status. Future orientation holds promise as a cognitive variable associated with decreased suicide risk; a better understanding of its putative protective role is needed. Treatments designed to enhance future orientation might decrease suicide risk.

Autocrine A2 in the T-System of Ventricular Myocytes Creates Transmural Gradients in Ion Transport: A Mechanism to Match Contraction with Load?

PubMed Central

Gao, Junyuan; Sun, Xiurong; Potapova, Irina A.; Cohen, Ira S.; Mathias, Richard T.; Kim, Jeremy H.

2014-01-01

Transmural heterogeneities in Na/K pump current (IP), transient outward K+-current (Ito), and Ca2+-current (ICaL) play an important role in regulating electrical and contractile activities in the ventricular myocardium. Prior studies indicated angiotensin II (A2) may determine the transmural gradient in Ito, but the effects of A2 on IP and ICaL were unknown. In this study, myocytes were isolated from five muscle layers between epicardium and endocardium. We found a monotonic gradient in both Ip and Ito, with the lowest currents in ENDO. When AT1Rs were inhibited, EPI currents were unaffected, but ENDO currents increased, suggesting endogenous extracellular A2 inhibits both currents in ENDO. IP- and Ito-inhibition by A2 yielded essentially the same K0.5 values, so they may both be regulated by the same mechanism. A2/AT1R-mediated inhibition of IP or Ito or stimulation of ICaL persisted for hours in isolated myocytes, suggesting continuous autocrine secretion of A2 into a restricted diffusion compartment, like the T-system. Detubulation brought EPI IP to its low ENDO value and eliminated A2 sensitivity, so the T-system lumen may indeed be the restricted diffusion compartment. These studies showed that 33–50% of IP, 57–65% of Ito, and a significant fraction of ICaL reside in T-tubule membranes where they are transmurally regulated by autocrine secretion of A2 into the T-system lumen and activation of AT1Rs. Increased AT1R activation regulates each of these currents in a direction expected to increase contractility. Endogenous A2 activation of AT1Rs increases monotonically from EPI to ENDO in a manner similar to reported increases in passive tension when the ventricular chamber fills with blood. We therefore hypothesize load is the signal that regulates A2-activation of AT1Rs, which create a contractile gradient that matches the gradient in load. PMID:24896115

Dating the origin and dispersal of Human Papillomavirus type 16 on the basis of ancestral human migrations.

PubMed

Zehender, Gianguglielmo; Frati, Elena Rosanna; Martinelli, Marianna; Bianchi, Silvia; Amendola, Antonella; Ebranati, Erika; Ciccozzi, Massimo; Galli, Massimo; Lai, Alessia; Tanzi, Elisabetta

2016-04-01

A major limitation when reconstructing the origin and evolution of HPV-16 is the lack of reliable substitution rate estimates for the viral genes. On the basis of the hypothesis of human HPV-16 co-divergence, we estimated a mean evolutionary rate of 1.47×10(-7) (95% HPD=0.64-2.47×10(-7)) subs/site/year for the viral LCR region. The results of a Bayesian phylogeographical analysis suggest that the currently circulating HPV-16 most probably originated in Africa about 110 thousand years ago (Kya), before giving rise to four known geographical lineages: the Asian/European lineage, which most probably originated in Asia a mean 38 Kya, and the Asian/American and two African lineages, which probably respectively originated about 33 and 27 Kya. These data closely reflect current hypotheses concerning modern human expansion based on studies of mitochondrial DNA phylogeny. The correlation between ancient human migration and the present HPV phylogeny may be explained by the co-existence of modes of transmission other than sexual transmission. Copyright © 2016. Published by Elsevier B.V.

Bayesian Modeling of Prion Disease Dynamics in Mule Deer Using Population Monitoring and Capture-Recapture Data

PubMed Central

Geremia, Chris; Miller, Michael W.; Hoeting, Jennifer A.; Antolin, Michael F.; Hobbs, N. Thompson

2015-01-01

Epidemics of chronic wasting disease (CWD) of North American Cervidae have potential to harm ecosystems and economies. We studied a migratory population of mule deer (Odocoileus hemionus) affected by CWD for at least three decades using a Bayesian framework to integrate matrix population and disease models with long-term monitoring data and detailed process-level studies. We hypothesized CWD prevalence would be stable or increase between two observation periods during the late 1990s and after 2010, with higher CWD prevalence making deer population decline more likely. The weight of evidence suggested a reduction in the CWD outbreak over time, perhaps in response to intervening harvest-mediated population reductions. Disease effects on deer population growth under current conditions were subtle with a 72% chance that CWD depressed population growth. With CWD, we forecasted a growth rate near one and largely stable deer population. Disease effects appear to be moderated by timing of infection, prolonged disease course, and locally variable infection. Long-term outcomes will depend heavily on whether current conditions hold and high prevalence remains a localized phenomenon. PMID:26509806

Measurement and simulation of unmyelinated nerve electrostimulation: Lumbricus terrestris experiment and numerical model

NASA Astrophysics Data System (ADS)

Šarolić, A.; Živković, Z.; Reilly, J. P.

2016-06-01

The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sinusoidal current. Experiments were performed on the single-axon measurement setup based on Lumbricus terrestris having unmyelinated nerve fibers. The simulations were performed using the well-established SENN model for a myelinated nerve. Although the unmyelinated experimental model differs from the myelinated simulation model, both refer to a single axon. Thus we hypothesized that the dependence on temporal and frequency parameters should be very similar. The comparison was made possible by normalizing each set of results to the SD time constant and the rheobase current of each model, yielding the curves that show the temporal and frequency dependencies regardless of the model differences. The results reasonably agree, suggesting that this experimental setup and method of comparison with SENN model can be used for further studies of waveform effect on nerve excitability, including unmyelinated neurons.

Development of an abbreviated Career Indecision Profile-65 using item response theory: The CIP-Short.

PubMed

Xu, Hui; Tracey, Terence J G

2017-03-01

The current study developed an abbreviated version of the Career Indecision Profile-65 (CIP-65; Hacker, Carr, Abrams, & Brown, 2013) by using item response theory. In order to improve the efficiency of the CIP-65 in measuring career indecision, the individual item performance of the CIP-65 was examined with respect to the ordering of response occurrence and gender differential item functioning. The best 5 items of each scale of the CIP-65 (i.e., neuroticism/negative affectivity, choice/commitment anxiety, lack of readiness, and interpersonal conflicts) were retained in the CIP-Short using a sample of 588 college students. A validation sample (N = 174) supported the reliability and structural validity of the CIP-Short. The convergent and divergent validity of the CIP-Short was additionally supported in the findings of a hypothesized differential relational pattern in a separate sample (N = 360). While the current study supported the CIP-Short being a sound brief measure of career indecision, the limitations of this study and suggestions for future research were discussed as well. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Bilingual toddlers have advanced abilities to repair communication failure.

PubMed

Wermelinger, Stephanie; Gampe, Anja; Daum, Moritz M

2017-03-01

Recent research has demonstrated enhanced communicative abilities in bilingual children compared with monolingual children throughout childhood and in a variety of domains. The processes underlying these advantages are, however, not well understood. It has been suggested that one aspect that particularly stimulates bilinguals' communication skills is their daily experience with challenging communication. In the current study, we investigated whether children's assumed experience with communication failures would increase their skills when it came to repairing communication failure. Non-German bilingual, German bilingual, and monolingual 2.5-year-old toddlers participated in a communication task in which a misunderstanding occurred. We hypothesized that monolingual and German bilingual children would have fewer daily communication failures-and, therefore, less well-trained repair skills-compared with non-German bilinguals. The results showed that non-German bilinguals were more likely to repair the misunderstanding compared with both monolingual children and German bilingual children. The current findings support the view that the communicative advantages of bilingual individuals develop based on their unique experience with interpersonal communication and its difficulties. Copyright © 2016 Elsevier Inc. All rights reserved.

Measurement and simulation of unmyelinated nerve electrostimulation: Lumbricus terrestris experiment and numerical model.

PubMed

Šarolić, A; Živković, Z; Reilly, J P

2016-06-21

The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sinusoidal current. Experiments were performed on the single-axon measurement setup based on Lumbricus terrestris having unmyelinated nerve fibers. The simulations were performed using the well-established SENN model for a myelinated nerve. Although the unmyelinated experimental model differs from the myelinated simulation model, both refer to a single axon. Thus we hypothesized that the dependence on temporal and frequency parameters should be very similar. The comparison was made possible by normalizing each set of results to the SD time constant and the rheobase current of each model, yielding the curves that show the temporal and frequency dependencies regardless of the model differences. The results reasonably agree, suggesting that this experimental setup and method of comparison with SENN model can be used for further studies of waveform effect on nerve excitability, including unmyelinated neurons.

Mechanisms of exercise-induced bronchoconstriction in athletes: Current perspectives and future challenges.

PubMed

Couto, M; Kurowski, M; Moreira, A; Bullens, D M A; Carlsen, K-H; Delgado, L; Kowalski, M L; Seys, S F

2018-01-01

The evidence of exercise-induced bronchoconstriction (EIB) without asthma (EIBw A ) occurring in athletes led to speculate about different endotypes inducing respiratory symptoms within athletes. Classical postulated mechanisms for bronchial obstruction in this population include the osmotic and the thermal hypotheses. More recently, the presence of epithelial injury and inflammation in the airways of athletes was demonstrated. In addition, neuronal activation has been suggested as a potential modulator of bronchoconstriction. Investigation of these emerging mechanisms is of major importance as EIB is a significant problem for both recreational and competitive athletes and is the most common chronic condition among Olympic athletes, with obvious implications for their competing performance, health and quality of life. Hereby, we summarize the latest achievements in this area and identify the current gaps of knowledge so that future research heads toward better defining the etiologic factors and mechanisms involved in development of EIB in elite athletes as well as essential aspects to ultimately propose preventive and therapeutic measures. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

Does environmental exposure to the greenhouse gas, N2O, contribute to etiological factors in neurodevelopmental disorders? A mini-review of the evidence.

PubMed

Fluegge, Keith

2016-10-01

Neurodevelopmental disorders are increasing in prevalence worldwide. Previous work suggests that exposure to the environmental air pollutant and greenhouse gas - nitrous oxide (N 2 O) - may be an etiological factor in neurodevelopmental disorders through the targeting of several neural correlates. While a number of recent systematic reviews have addressed the role of general anesthesia in the surgical setting and neurodevelopmental outcomes, a narrative mini-review was conducted to first define and characterize the relevant variables (i.e., N 2 O, attention-deficit hyperactivity disorder [ADHD] and autism spectrum disorders [ASD]) and their potential interactions into a coherent, hypothesis-generating work. The narrative mini-review merges basic principles in environmental science, anesthesiology, and psychiatry to more fully develop the novel hypotheses that neurodevelopmental impairment found in conditions like ADHD and ASD may be due to exposure to the increasing air pollutant, N 2 O. The results of the present mini-review indicate that exposure to N 2 O, even at non-toxic doses, may modulate central neurotransmission and target many neural substrates directly implicated in neurodevelopmental disorders, including the glutamatergic, opioidergic, cholinergic, and dopaminergic systems. Epidemiological studies also indicate that early and repeated exposure to general anesthesia, including N 2 O, may contribute to later adverse neurodevelopmental outcomes in children. The current evidence and subsequent hypotheses suggest that a renewed interest be taken in the toxicological assessment of environmental N 2 O exposure using validated biomarkers and psychiatric endpoints. Given the relevance of N 2 O as a greenhouse gas, societies may also wish to engage in a more robust monitoring and reporting of N 2 O levels in the environment for climactic benefit as well. Copyright © 2016 Elsevier B.V. All rights reserved.

Morphological "primary homology" and expression of AG-subfamily MADS-box genes in pines, podocarps, and yews.

PubMed

Englund, Marie; Carlsbecker, Annelie; Engström, Peter; Vergara-Silva, Francisco

2011-01-01

The morphological variation among reproductive organs of extant gymnosperms is remarkable, especially among conifers. Several hypotheses concerning morphological homology between various conifer reproductive organs have been put forward, in particular in relation to the pine ovuliferous scale. Here, we use the expression patterns of orthologs of the ABC-model MADS-box gene AGAMOUS (AG) for testing morphological homology hypotheses related to organs of the conifer female cone. To this end, we first developed a tailored 3'RACE procedure that allows reliable amplification of partial sequences highly similar to gymnosperm-derived members of the AG-subfamily of MADS-box genes. Expression patterns of two novel conifer AG orthologs cloned with this procedure-namely PodAG and TgAG, obtained from the podocarp Podocarpus reichei and the yew Taxus globosa, respectively-are then further characterized in the morphologically divergent female cones of these species. The expression patterns of PodAG and TgAG are compared with those of DAL2, a previously discovered Picea abies (Pinaceae) AG ortholog. By treating the expression patterns of DAL2, PodAG, and TgAG as character states mapped onto currently accepted cladogram topologies, we suggest that the epimatium-that is, the podocarp female cone organ previously postulated as a "modified" ovuliferous scale-and the canonical Pinaceae ovuliferous scale can be legitimally conceptualized as "primary homologs." Character state mapping for TgAG suggests in turn that the aril of Taxaceae should be considered as a different type of organ. This work demonstrates how the interaction between developmental-genetic data and formal cladistic theory could fruitfully contribute to gymnosperm systematics. © 2011 Wiley Periodicals, Inc.

Status report : SOCRATES concept exploration effort

DOT National Transportation Integrated Search

2001-09-01

Project SOCRATES, development of a technology to detect hypothesized acoustic emanations from wake vortices, has been : underway for more than four years. This report discusses several aspects of this project including the current level of knowledge ...

Self-monitoring in the cerebral cortex: Neural responses to small pitch shifts in auditory feedback during speech production.

PubMed

Franken, Matthias K; Eisner, Frank; Acheson, Daniel J; McQueen, James M; Hagoort, Peter; Schoffelen, Jan-Mathijs

2018-06-21

Speaking is a complex motor skill which requires near instantaneous integration of sensory and motor-related information. Current theory hypothesizes a complex interplay between motor and auditory processes during speech production, involving the online comparison of the speech output with an internally generated forward model. To examine the neural correlates of this intricate interplay between sensory and motor processes, the current study uses altered auditory feedback (AAF) in combination with magnetoencephalography (MEG). Participants vocalized the vowel/e/and heard auditory feedback that was temporarily pitch-shifted by only 25 cents, while neural activity was recorded with MEG. As a control condition, participants also heard the recordings of the same auditory feedback that they heard in the first half of the experiment, now without vocalizing. The participants were not aware of any perturbation of the auditory feedback. We found auditory cortical areas responded more strongly to the pitch shifts during vocalization. In addition, auditory feedback perturbation resulted in spectral power increases in the θ and lower β bands, predominantly in sensorimotor areas. These results are in line with current models of speech production, suggesting auditory cortical areas are involved in an active comparison between a forward model's prediction and the actual sensory input. Subsequently, these areas interact with motor areas to generate a motor response. Furthermore, the results suggest that θ and β power increases support auditory-motor interaction, motor error detection and/or sensory prediction processing. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Interrogative suggestibility among adolescent boys and its relationship with intelligence, memory, and cognitive set.

PubMed

Singh, K K; Gudjonsson, G H

1992-06-01

This study investigates some of the hypotheses generated by the Gudjonsson and Clark model of interrogative suggestibility. The subjects were 40 adolescent boys (11-16 years), who completed the Gudjonsson Suggestibility Scale and instruments measuring intellectual skills, memory, field-dependence, hostility, and attitudes towards persons in authority. Suggestibility correlated negatively with I.Q. and memory capacity, and positively with field-dependence.

Serotonin 5-HT2C receptor-mediated inhibition of the M-current in hypothalamic POMC neurons.

PubMed

Roepke, T A; Smith, A W; Rønnekleiv, O K; Kelly, M J

2012-06-01

Hypothalamic proopiomelanocortin (POMC) neurons are controlled by many central signals, including serotonin. Serotonin increases POMC activity and reduces feeding behavior via serotonion [5-hydroxytryptamine (5-HT)] receptors by modulating K(+) currents. A potential K(+) current is the M-current, a noninactivating, subthreshold outward K(+) current. Previously, we found that M-current activity was highly reduced in fasted vs. fed states in neuropeptide Y neurons. Because POMC neurons also respond to energy states, we hypothesized that fasting may alter the M-current and/or its modulation by serotonergic input to POMC neurons. Using visualized-patch recording in neurons from fed male enhanced green fluorescent protein-POMC transgenic mice, we established that POMC neurons expressed a robust M-current (102.1 ± 6.7 pA) that was antagonized by the selective KCNQ channel blocker XE-991 (40 μM). However, the XE-991-sensitive current in POMC neurons did not differ between fed and fasted states. To determine if serotonin suppresses the M-current via the 5-HT(2C) receptor, we examined the effects of the 5-HT(2A)/5-HT(2C) receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) on the M-current. Indeed, DOI attenuated the M-current by 34.5 ± 6.9% and 42.0 ± 5.3% in POMC neurons from fed and fasted male mice, respectively. In addition, the 5-HT(1B)/5-HT(2C) receptor agonist m-chlorophenylpiperazine attenuated the M-current by 42.4 ± 5.4% in POMC neurons from fed male mice. Moreover, the selective 5-HT(2C) receptor antagonist RS-102221 abrogated the actions of DOI in suppressing the M-current. Collectively, these data suggest that although M-current expression does not differ between fed and fasted states in POMC neurons, serotonin inhibits the M-current via activation of 5-HT(2C) receptors to increase POMC neuronal excitability and, subsequently, reduce food intake.

The revelation effect: A meta-analytic test of hypotheses.

PubMed

Aßfalg, André; Bernstein, Daniel M; Hockley, William

2017-12-01

Judgments can depend on the activity directly preceding them. An example is the revelation effect whereby participants are more likely to claim that a stimulus is familiar after a preceding task, such as solving an anagram, than without a preceding task. We test conflicting predictions of four revelation-effect hypotheses in a meta-analysis of 26 years of revelation-effect research. The hypotheses' predictions refer to three subject areas: (1) the basis of judgments that are subject to the revelation effect (recollection vs. familiarity vs. fluency), (2) the degree of similarity between the task and test item, and (3) the difficulty of the preceding task. We use a hierarchical multivariate meta-analysis to account for dependent effect sizes and variance in experimental procedures. We test the revelation-effect hypotheses with a model selection procedure, where each model corresponds to a prediction of a revelation-effect hypothesis. We further quantify the amount of evidence for one model compared to another with Bayes factors. The results of this analysis suggest that none of the extant revelation-effect hypotheses can fully account for the data. The general vagueness of revelation-effect hypotheses and the scarcity of data were the major limiting factors in our analyses, emphasizing the need for formalized theories and further research into the puzzling revelation effect.

Bayesian meta-analysis of Cronbach's coefficient alpha to evaluate informative hypotheses.

PubMed

Okada, Kensuke

2015-12-01

This paper proposes a new method to evaluate informative hypotheses for meta-analysis of Cronbach's coefficient alpha using a Bayesian approach. The coefficient alpha is one of the most widely used reliability indices. In meta-analyses of reliability, researchers typically form specific informative hypotheses beforehand, such as 'alpha of this test is greater than 0.8' or 'alpha of one form of a test is greater than the others.' The proposed method enables direct evaluation of these informative hypotheses. To this end, a Bayes factor is calculated to evaluate the informative hypothesis against its complement. It allows researchers to summarize the evidence provided by previous studies in favor of their informative hypothesis. The proposed approach can be seen as a natural extension of the Bayesian meta-analysis of coefficient alpha recently proposed in this journal (Brannick and Zhang, 2013). The proposed method is illustrated through two meta-analyses of real data that evaluate different kinds of informative hypotheses on superpopulation: one is that alpha of a particular test is above the criterion value, and the other is that alphas among different test versions have ordered relationships. Informative hypotheses are supported from the data in both cases, suggesting that the proposed approach is promising for application. Copyright © 2015 John Wiley & Sons, Ltd.

How Transformational Leadership Influences Work Engagement Among Nurses: Does Person-Job Fit Matter?

PubMed

Enwereuzor, Ibeawuchi K; Ugwu, Leonard I; Eze, Onyinyechi A

2018-03-01

The current study examines whether person-job fit moderates the relationship between transformational leadership and work engagement. Data were collected using cross-sectional design from 224 (15 male and 209 female) hospital nurses. Participants completed measures of transformational leadership, person-job fit, and work engagement. Moderated multiple regression results showed that transformational leadership had a significant positive predictive relationship with work engagement, and person-job fit had a significant positive predictive relationship with work engagement. Simple slope analysis showed that person-job fit moderated the relationship between transformational leadership and work engagement such that transformational leadership was more positively related to work engagement for nurses with high person-job fit compared with those with low person-job fit. Thus, all the hypotheses were confirmed. The findings were discussed, and suggestions for future research were offered.

Prospective Prediction of Women’s Sexual Victimization by Intimate and Nonintimate Male Perpetrators

PubMed Central

Testa, Maria; VanZile-Tamsen, Carol; Livingston, Jennifer A.

2007-01-01

Although behavioral risk factors such as substance use have been hypothesized to increase women’s vulnerability to sexual victimization, prospective studies provide mixed empirical support. In the current prospective study, the authors considered substance use, sexual activity, and sexual assertiveness as predictors of sexual victimization from intimate partners and nonintimate perpetrators. Among a representative community sample of women ages 18–30 years (N = 927), 17.9% reported sexual victimization over 2 years, the majority by an intimate partner. Low sexual refusal assertiveness, drug use, and prior intimate partner victimization predicted intimate partner sexual victimization. Heavy episodic drinking and number of sexual partners predicted victimization from nonintimates. The finding that there are different risk factors for sexual victimization from intimates versus nonintimates suggests the need for tailored prevention strategies. PMID:17295563

Why did the white bear return? Obsessive-compulsive symptoms and attributions for unsuccessful thought suppression

PubMed Central

Magee, Joshua C.; Teachman, Bethany A.

2007-01-01

The current study examined the nature and consequences of attributions about unsuccessful thought suppression. Undergraduate students with either high (N=67) or low (N=59) levels of obsessive-compulsive symptoms rated attributions to explain their unsuccessful thought suppression attempts. We expected that self-blaming attributions and attributions ascribing importance to unwanted thoughts would predict more distress and greater recurrence of thoughts during time spent monitoring or suppressing unwanted thoughts. Further, we expected that these attributions would mediate the relationship between obsessive-compulsive symptom levels and the negative thought suppression outcomes (distress and thought recurrence). Structural equation models largely confirmed the hypotheses, suggesting that attributions may be an important factor in explaining the consequences of thought suppression. Implications are discussed for cognitive theories of obsessive-compulsive disorder and thought suppression. PMID:17825786

Impaired acuity of the approximate number system underlies mathematical learning disability (dyscalculia).

PubMed

Mazzocco, Michèle M M; Feigenson, Lisa; Halberda, Justin

2011-01-01

Many children have significant mathematical learning disabilities (MLD, or dyscalculia) despite adequate schooling. The current study hypothesizes that MLD partly results from a deficiency in the Approximate Number System (ANS) that supports nonverbal numerical representations across species and throughout development. In this study of 71 ninth graders, it is shown that students with MLD have significantly poorer ANS precision than students in all other mathematics achievement groups (low, typically, and high achieving), as measured by psychophysical assessments of ANS acuity (w) and of the mappings between ANS representations and number words (cv). This relation persists even when controlling for domain-general abilities. Furthermore, this ANS precision does not differentiate low-achieving from typically achieving students, suggesting an ANS deficit that is specific to MLD. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

Freshwater ecosystems and aquatic insects: a paradox in biological invasions.

PubMed

Fenoglio, Stefano; Bonada, Núria; Guareschi, Simone; López-Rodríguez, Manuel J; Millán, Andrés; Tierno de Figueroa, J Manuel

2016-04-01

Biological invasions have increased significantly in response to global change and constitute one of the major causes of biodiversity loss. Insects make up a large fraction of invasive species, in general, and freshwaters are among the most invaded ecosystems on our planet. However, even though aquatic insects dominate most inland waters, have unparalleled taxonomic diversity and occupy nearly all trophic niches, there are almost no invasive insects in freshwaters. We present some hypotheses regarding why aquatic insects are not common among aquatic invasive organisms, suggesting that it may be the result of a suite of biological, ecological and anthropogenic factors. Such specific knowledge introduces a paradox in the current scientific discussion on invasive species; therefore, a more in-depth understanding could be an invaluable aid to disentangling how and why biological invasions occur. © 2016 The Author(s).

Galvanostatic interruption of lithium insertion into magnetite: Evidence of surface layer formation

DOE PAGES

Nicholas W. Brady; Takeuchi, Esther S.; Knehr, K. W.; ...

2016-04-24

Magnetite is a known lithium intercalation material, and the loss of active, nanocrystalline magnetite can be inferred from the open-circuit potential relaxation. Specifically, for current interruption after relatively small amounts of lithium insertion, the potential first increases and then decreases, and the decrease is hypothesized to be due to a formation of a surface layer, which increases the solid-state lithium concentration in the remaining active material. Comparisons of simulation to experiment suggest that the reactions with the electrolyte result in the formation of a thin layer of electrochemically inactive material, which is best described by a nucleation and growth mechanism.more » Simulations are consistent with experimental results observed for 6, 8 and 32-nm crystals. As a result, simulations capture the experimental differences in lithiation behavior between the first and second cycles.« less

Relational Motives Reduce Attentional Adhesion to Attractive Alternatives in Heterosexual University Students in China.

PubMed

Zhang, Qiuli; Maner, Jon K; Xu, Yin; Zheng, Yong

2017-02-01

In heterosexual individuals, attention is automatically captured by physically attractive members of the opposite sex. Although helpful for selecting new mates, attention to attractive relationship alternatives can threaten satisfaction with and commitment to an existing romantic relationship. The current study tested the hypothesis that although a mating prime would increase selective attention to attractive opposite-sex targets (relative to less attractive targets) among single participants, this effect would be reduced among people already committed to a long-term romantic partner. Consistent with hypotheses, whereas single participants responded to a mating prime with greater attentional adhesion to physically attractive opposite-sex targets (relative to less attractive targets), participants in a committed romantic relationship showed no such effect. These findings extend previous research suggesting the presence of relationship maintenance mechanisms that operate at early stages of social cognition.

Effects of Harsh and Unpredictable Environments in Adolescence on Development of Life History Strategies

PubMed Central

Figueredo, Aurelio José; Ellis, Bruce J.

2010-01-01

The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique variance in expression of adolescent and young adult life history strategies, and (3) adolescent life history traits would predict young adult life history strategy. These predictions were supported. The current findings suggest that the environmental parameters of harshness and unpredictability have concurrent effects on life history development in adolescence, as well as longitudinal effects into young adulthood. In addition, life history traits appear to be stable across developmental time from adolescence into young adulthood. PMID:20634914

Discovery of skin alkaloids in a miniaturized eleutherodactylid frog from Cuba

PubMed Central

Rodríguez, Ariel; Poth, Dennis; Schulz, Stefan; Vences, Miguel

2011-01-01

Four phylogenetically independent lineages of frogs are currently known to sequester lipid-soluble skin alkaloids for which a dietary source has been demonstrated. We report here a remarkable fifth such instance, in Eleutherodactylus iberia and Eleutherodactylus orientalis, two species of miniaturized frogs of the family Eleutherodactylidae from Cuba. Six pumiliotoxins and two indolizidines were found in E. iberia, one of the smallest frogs in the world and characterized by a contrasting colour pattern for which we hypothesize an aposematic function. Analyses of stomach content indicated a numerical prevalence of mites with an important proportion of oribatids—a group of arthropods known to contain one of the pumiliotoxins detected in E. iberia. This suggests that miniaturization and specialization to small prey may have favoured the acquisition of dietary skin alkaloids in these amphibians. PMID:21047848

Using advanced tomography techniques to investigate the development of White Etching Cracks in a prematurely failed field bearing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gould, Benjamin; Greco, Aaron; Stadler, Kenred

Crack surrounded by areas of microstructural alteration deemed "White etching cracks" (WECs) lead to premature failures within a multitude applications. While the exact cause of these failures remains unknown, a large number of hypotheses exist as to how and why these cracks form. The aim of the current work is to study newly initiated WEC networks using X-ray tomography followed by selective sectioning, in an attempt to elucidate the formation mechanisms of these cracks. The results obtained show that, for the presented bearing, WECs form preferentially around multi-phase inclusions containing aluminum, manganese, and sulfur. Additionally the results support the ideamore » that the microstructural alterations form secondary to any cracking, suggesting that the alterations are simply a symptom of a preexisting failure.« less

Model-Data Fusion to Test Hypothesized Drivers of Lake Carbon Cycling Reveals Importance of Physical Controls

NASA Astrophysics Data System (ADS)

Hararuk, Oleksandra; Zwart, Jacob A.; Jones, Stuart E.; Prairie, Yves; Solomon, Christopher T.

2018-03-01

Formal integration of models and data to test hypotheses about the processes controlling carbon dynamics in lakes is rare, despite the importance of lakes in the carbon cycle. We built a suite of models (n = 102) representing different hypotheses about lake carbon processing, fit these models to data from a north-temperate lake using data assimilation, and identified which processes were essential for adequately describing the observations. The hypotheses that we tested concerned organic matter lability and its variability through time, temperature dependence of biological decay, photooxidation, microbial dynamics, and vertical transport of water via hypolimnetic entrainment and inflowing density currents. The data included epilimnetic and hypolimnetic CO2 and dissolved organic carbon, hydrologic fluxes, carbon loads, gross primary production, temperature, and light conditions at high frequency for one calibration and one validation year. The best models explained 76-81% and 64-67% of the variability in observed epilimnetic CO2 and dissolved organic carbon content in the validation data. Accurately describing C dynamics required accounting for hypolimnetic entrainment and inflowing density currents, in addition to accounting for biological transformations. In contrast, neither photooxidation nor variable organic matter lability improved model performance. The temperature dependence of biological decay (Q10) was estimated at 1.45, significantly lower than the commonly assumed Q10 of 2. By confronting multiple models of lake C dynamics with observations, we identified processes essential for describing C dynamics in a temperate lake at daily to annual scales, while also providing a methodological roadmap for using data assimilation to further improve understanding of lake C cycling.

Dispositional resilience as a moderator of the relationship between chronic stress and irregular menstrual cycle.

PubMed

Palm-Fischbacher, Simona; Ehlert, Ulrike

2014-06-01

Menstrual-cycle irregularity may have an important influence on the subsequent development of chronic diseases. Several risk factors for irregular menstrual cycles have been detected, including stress. Our aim was to extend research on the link between chronic stress and menstrual-cycle irregularity and to assess potential protective factors, such as dispositional resilience, which we hypothesize to be associated with the maintenance or promotion of a healthy menstrual cycle. For this cross-sectional study, data on 696 healthy women aged 20-40 years were obtained. The women completed measures of chronic stress, dispositional resilience and menstrual-cycle irregularity. Furthermore, potential confounds were assessed. Of the participants, 383 (55%) reported no current use of hormonal contraceptives; 313 (45%) reported current use hormonal contraception and were included as a control group. The results suggest that in women not using hormonal contraception, chronic stress (OR = 1.05, 95%CI = 1.02-1.08, p = 0.001) and dispositional resilience (OR = 0.43, 95%CI = 0.31-0.59, p < 0.001) have a main effect on menstrual cycle regularity. In addition, women with greater dispositional resilience have reduced risk for irregular menstrual cycles in the face of low to moderate chronic stress; however, this association is changed at the highest level of chronic stress. These findings suggest that dispositional resilience may be a protective psychological trait that modulates reproductive functioning.

Masculine Traits and Depressive Symptoms in Older and Younger Men and Women.

PubMed

Price, Elizabeth C; Gregg, Jeffrey J; Smith, Merideth D; Fiske, Amy

2018-01-01

Evidence suggests that men who strongly endorse masculine traits display an atypical presentation of depression, including more externalizing symptoms (e.g., anger or substance use), but fewer typical, internalizing symptoms (e.g., depressed mood or crying). This phenomenon has not been adequately explored in older adults or women. The current study used the externalizing subscale of the Masculine Depression Scale in older and younger men and women to detect atypical symptoms. It was predicted that individuals who more strongly endorsed masculine traits would have higher scores on the measure of externalizing symptoms relative to a measure of typical depressive symptoms Center for Epidemiologic Studies-Depression Scale. It was anticipated that results would differ by age-group but not by gender. Multigroup path analysis was used to test the hypothesis. The hypothesized path model, in which endorsement of masculine traits was associated with lower scores on the Center for Epidemiologic Studies-Depression Scale and with scores on the externalizing, but not internalizing, factor of the Masculine Depression Scale, fit the data well. Results differed significantly by age-group and gender. Masculine individuals reported lower levels of typical depressive symptoms relative to externalizing symptoms, but further research is needed within age- and gender groups. Results are consistent with the gendered responding framework and suggest that current assessment tools, which tend to focus on internalizing symptoms of depression, may not detect depression in individuals who endorse masculine traits.

Inadvertent Polychlorinated Biphenyls in Commercial Paint Pigments†

PubMed Central

2009-01-01

A polychlorinated biphenyl (PCB) that was not produced as part of the Aroclor mixtures banned in the 1980s was recently reported in air samples collected in Chicago, Philadelphia, the Arctic, and several sites around the Great Lakes. In Chicago, the congener 3,3′-dichlorobiphenyl or PCB11 was found to be the fifth most concentrated congener and ubiquitous throughout the city. The congener exhibited strong seasonal concentration trends that suggest volatilization of this compound from common outdoor surfaces. Due to these findings and also the compound’s presence in waters that received waste from paint manufacturing facilities, we hypothesized that PCB11 may be present in current commercial paint. In this study we measured PCBs in paint sold on the current retail market. We tested 33 commercial paint pigments purchased from three local paint stores. The pigment samples were analyzed for all 209 PCB congeners using gas chromatography with tandem mass spectrometry (GC-MS/MS). More than 50 PCB congeners including several dioxin-like PCBs were detected, and the PCB profiles varied due to different types of pigments and different manufacturing processes. PCB congeners were detected in azo and phthalocyanine pigments which are commonly used in paint but also in inks, textiles, paper, cosmetics, leather, plastics, food and other materials. Our findings suggest several possible mechanisms for the inadvertent production of specific PCB congeners during the manufacturing of paint pigments. PMID:19957996

Possibilities and limitations of rod-beam theories. [nonlinear distortion tensor and nonlinear stress tensors

NASA Technical Reports Server (NTRS)

Peterson, D.

1979-01-01

Rod-beam theories are founded on hypotheses such as Bernouilli's suggesting flat cross-sections under deformation. These assumptions, which make rod-beam theories possible, also limit the accuracy of their analysis. It is shown that from a certain order upward terms of geometrically nonlinear deformations contradict the rod-beam hypotheses. Consistent application of differential geometry calculus also reveals differences from existing rod theories of higher order. These differences are explained by simple examples.

Ecological niche differentiation of polyploidization is not supported by environmental differences among species in a cosmopolitan grass genus.

PubMed

Visser, Vernon; Molofsky, Jane

2015-01-01

• Polyploidization frequently results in the creation of new plant species, the establishment of which is thought to often be facilitated by ecological niche differentiation from the diploid species. We tested this hypothesis using the cosmopolitan grass genus Phalaris (Poaceae), consisting of 19 species that range from diploid to tetraploid to hexaploid. Specifically, we tested whether (1) polyploids occupy more extreme environments and/or (2) have broader niche breadths and/or (3) whether the polyploid species' distributions indicate a niche shift from diploid species.• We employed a bootstrapping approach using distribution data for each species and eight environmental variables to investigate differences between species in the means, extremes, and breadths of each environmental variable. We used a kernel smoothing technique to quantify niche overlap between species.• Although we found some support for the three hypotheses for a few diploid-polyploid pairs and for specific environmental variables, none of these hypotheses were generally supported.• Our results suggest that these commonly held hypotheses about the effects of polyploidization on ecological distributions are not universally applicable. Correlative biogeographic studies like ours provide a necessary first step for suggesting specific hypotheses that require experimental verification. A combination of genetic, physiological, and ecological studies will be required to achieve a better understanding of the role of polyploidization in niche evolution. © 2015 Botanical Society of America, Inc.

Competitive inhibition of the nondepolarizing muscle relaxant rocuronium on nicotinic acetylcholine receptor channels in the rat superior cervical ganglia.

PubMed

Zhang, Chengmi; Wang, Zhenmeng; Zhang, Jinmin; Qiu, Haibo; Sun, Yuming; Yang, Liqun; Wu, Feixiang; Zheng, Jijian; Yu, Weifeng

2014-05-01

A number of case reports now indicate that rocuronium can induce a number of serious side effects. We hypothesized that these side effects might be mediated by the inhibition of nicotinic acetylcholine receptors (nAChRs) at superior cervical ganglion (SCG) neurons. Conventional patch clamp recordings were used to study the effects of rocuronium on nAChR currents from enzymatically dissociated rat SCG neurons. We found that ACh induced a peak transient inward current in rat SCG neurons. Additionally, rocuronium suppressed the peak ACh-evoked currents in rat SCG neurons in a concentration-dependent and competitive manner, and it increased the extent of desensitization of nAChRs. The inhibitory rate of rocuronium on nAChR currents did not change significantly at membrane potentials between -70 and -20 mV, suggesting that this inhibition was voltage independent. Lastly, rocuronium preapplication enhanced its inhibitory effect, indicating that this drug might prefer to act on the closed state of nAChR channels. In conclusion, rocuronium, at clinically relevant concentrations, directly inhibits nAChRs at the SCG by interacting with both opened and closed states. This inhibition is competitive, dose dependent, and voltage independent. Blockade of synaptic transmission in the sympathetic ganglia by rocuronium might have potentially inhibitory effects on the cardiovascular system.

Transfer factor - hypotheses for its structure and function.

PubMed

Shifrine, M; Scibienski, R

1975-01-01

Transfer factor (TF) is a dialyzable extract from primed lymphocytes that is able to transfer specific delayed hypersensitivity from one animal to another. On the basis of available data we suggest that TF is a polypeptide with a molecular weight below 15,000 daltons. We hypothesize that TF is the variable light or heavy chain domain of immunoglobulin: such a molecule conforms with the accepted properties of TF and also has the necessary specificity requirements. We also hypothesize that TF is part of a receptor site. beta-2-microglobulin, a molecule that is an integral part of cell surfaces, could be the anchor for TF. beta-2-microglobulin has homologies with the constant portion of immunoglobulin light or heavy chain and thus would combine with the variable domain (TF) to form a complete receptor site for a specific antigen. The properties of TF suggest its mode of action, which is discussed in detail in the text. The biologic advantages of TF is its ability to confer immediate (immunologie specific) protection while the 'normal' immune response develops.

Women's Education, Marital Violence, and Divorce: A Social Exchange Perspective.

PubMed

Kreager, Derek A; Felson, Richard B; Warner, Cody; Wenger, Marin R

2013-06-01

Drawing on social exchange theories, the authors hypothesized that educated women are more likely than uneducated women to leave violent marriages and suggested that this pattern offsets the negative education - divorce association commonly found in the United States. They tested these hypotheses using 2 waves of young adult data on 914 married women from the National Longitudinal Study of Adolescent Health. The evidence suggests that the negative relationship between women's education and divorce is weaker when marriages involve abuse than when they do not. The authors observed a similar pattern when they examined the association of women's proportional earnings and divorce, controlling for education. Supplementary analyses suggested that marital satisfaction explains some of the association among women's resources, victimization, and divorce but that marital violence continues to be a significant moderator of the education - divorce association. In sum, education appears to benefit women by both maintaining stable marriages and dissolving violent ones.

Paranormal experience and the COMT dopaminergic gene: a preliminary attempt to associate phenotype with genotype using an underlying brain theory.

PubMed

Raz, Amir; Hines, Terence; Fossella, John; Castro, Daniella

2008-01-01

Paranormal belief and suggestibility seem related. Given our recent findings outlining a putative association between suggestibility and a specific dopaminergic genetic polymorphism, we hypothesized that similar exploratory genetic data may offer supplementary insights into a similar correlation with paranormal belief. With more affordable costs and better technology in the aftermath of the human genome project, genotyping is increasingly ubiquitous. Compelling brain theories guide specific research hypotheses as scientists begin to unravel tentative relationships between phenotype and genotype. In line with a dopaminergic brain theory, we tried to correlate a specific phenotype concerning paranormal belief with a dopaminergic gene (COMT) known for its involvement in prefrontal executive cognition and for a polymorphism that is positively correlated with suggestibility. Although our preliminary findings are inconclusive, the research approach we outline should pave the road to a more scientific account of elucidating paranormal belief.

Evolutionary transitions towards eusociality in snapping shrimps.

PubMed

Chak, Solomon Tin Chi; Duffy, J Emmett; Hultgren, Kristin M; Rubenstein, Dustin R

2017-03-20

Animal social organization varies from complex societies where reproduction is dominated by a single individual (eusociality) to those where reproduction is more evenly distributed among group members (communal breeding). Yet, how simple groups transition evolutionarily to more complex societies remains unclear. Competing hypotheses suggest that eusociality and communal breeding are alternative evolutionary endpoints, or that communal breeding is an intermediate stage in the transition towards eusociality. We tested these alternative hypotheses in sponge-dwelling shrimps, Synalpheus spp. Although species varied continuously in reproductive skew, they clustered into pair-forming, communal and eusocial categories based on several demographic traits. Evolutionary transition models suggested that eusocial and communal species are discrete evolutionary endpoints that evolved independently from pair-forming ancestors along alternative paths. This 'family-centred' origin of eusociality parallels observations in insects and vertebrates, reinforcing the role of kin selection in the evolution of eusociality and suggesting a general model of animal social evolution.

Current hormonal contraceptive use predicts female extra-pair and dyadic sexual behavior: evidence based on Czech National Survey data.

PubMed

Klapilová, Kateřina; Cobey, Kelly D; Wells, Timothy; Roberts, S Craig; Weiss, Petr; Havlíček, Jan

2014-01-10

Data from 1155 Czech women (493 using oral contraception, 662 non-users), obtained from the Czech National Survey of Sexual Behavior, were used to investigate evolutionary-based hypotheses concerning the predictive value of current oral contraceptive (OC) use on extra-pair and dyadic (in-pair) sexual behavior of coupled women. Specifically, the aim was to determine whether current OC use was associated with lower extra-pair and higher in-pair sexual interest and behavior, because OC use suppresses cyclical shifts in mating psychology that occur in normally cycling women. Zero-inflated Poisson (ZIP) regression and negative binomial models were used to test associations between OC use and these sexual measures, controlling for other relevant predictors (e.g., age, parity, in-pair sexual satisfaction, relationship length). The overall incidence of having had an extra-pair partner or one-night stand in the previous year was not related to current OC use (the majority of the sample had not). However, among the women who had engaged in extra-pair sexual behavior, OC users had fewer one-night stands than non-users, and tended to have fewer partners, than non-users. OC users also had more frequent dyadic intercourse than non-users, potentially indicating higher commitment to their current relationship. These results suggest that suppression of fertility through OC use may alter important aspects of female sexual behavior, with potential implications for relationship functioning and stability.

Chronic traumatic encephalopathy and athletes

PubMed Central

Mannix, Rebekah; Zafonte, Ross; Pascual-Leone, Alvaro

2015-01-01

Recent case reports have described athletes previously exposed to repetitive head trauma while participating in contact sports who later in life developed mood disorders, headaches, cognitive difficulties, suicidal ideation, difficulties with speech, and aggressive behavior. Postmortem discoveries show that some of these athletes have pathologic findings that are collectively termed chronic traumatic encephalopathy (CTE). Current hypotheses suggest that concussions or perhaps blows to the head that do not cause the signs and symptoms necessary for making the diagnosis of concussion, so-called subconcussive blows, cause both the clinical and pathologic findings. There are, however, some athletes who participate in contact sports who do not develop the findings ascribed to CTE. Furthermore, there are people who have headaches, mood disorders, cognitive difficulties, suicidal ideation, and other clinical problems who have neither been exposed to repeated head trauma nor possessed the pathologic postmortem findings of those currently diagnosed with CTE. The current lack of prospective data and properly designed case-control studies limits the current understanding of CTE, leading to debate about the causes of the neuropathologic findings and the clinical observations. Given the potential for referral and recall bias in available studies, it remains unclear whether or not the pathologic findings made postmortem cause the presumed neurobehavioral sequela and whether the presumed risk factors, such as sports activity, cerebral concussions, and subconcussive blows, are solely causative of the clinical signs and symptoms. This article discusses the current evidence and the associated limitations. PMID:26253448

Chronic traumatic encephalopathy and athletes.

PubMed

Meehan, William; Mannix, Rebekah; Zafonte, Ross; Pascual-Leone, Alvaro

2015-10-27

Recent case reports have described athletes previously exposed to repetitive head trauma while participating in contact sports who later in life developed mood disorders, headaches, cognitive difficulties, suicidal ideation, difficulties with speech, and aggressive behavior. Postmortem discoveries show that some of these athletes have pathologic findings that are collectively termed chronic traumatic encephalopathy (CTE). Current hypotheses suggest that concussions or perhaps blows to the head that do not cause the signs and symptoms necessary for making the diagnosis of concussion, so-called subconcussive blows, cause both the clinical and pathologic findings. There are, however, some athletes who participate in contact sports who do not develop the findings ascribed to CTE. Furthermore, there are people who have headaches, mood disorders, cognitive difficulties, suicidal ideation, and other clinical problems who have neither been exposed to repeated head trauma nor possessed the pathologic postmortem findings of those currently diagnosed with CTE. The current lack of prospective data and properly designed case-control studies limits the current understanding of CTE, leading to debate about the causes of the neuropathologic findings and the clinical observations. Given the potential for referral and recall bias in available studies, it remains unclear whether or not the pathologic findings made postmortem cause the presumed neurobehavioral sequela and whether the presumed risk factors, such as sports activity, cerebral concussions, and subconcussive blows, are solely causative of the clinical signs and symptoms. This article discusses the current evidence and the associated limitations. © 2015 American Academy of Neurology.

Perceptions as Hypotheses

NASA Astrophysics Data System (ADS)

Gregory, R. L.

1980-07-01

Perceptions may be compared with hypotheses in science. The methods of acquiring scientific knowledge provide a working paradigm for investigating processes of perception. Much as the information channels of instruments, such as radio telescopes, transmit signals which are processed according to various assumptions to give useful data, so neural signals are processed to give data for perception. To understand perception, the signal codes and the stored knowledge or assumptions used for deriving perceptual hypotheses must be discovered. Systematic perceptual errors are important clues for appreciating signal channel limitations, and for discovering hypothesis-generating procedures. Although this distinction between `physiological' and `cognitive' aspects of perception may be logically clear, it is in practice surprisingly difficult to establish which are responsible even for clearly established phenomena such as the classical distortion illusions. Experimental results are presented, aimed at distinguishing between and discovering what happens when there is mismatch with the neural signal channel, and when neural signals are processed inappropriately for the current situation. This leads us to make some distinctions between perceptual and scientific hypotheses, which raise in a new form the problem: What are `objects'?

Breast cancer risk associated with genotypic polymorphism of the nonhomologous end-joining genes: a multigenic study on cancer susceptibility.

PubMed

Fu, Yi-Ping; Yu, Jyh-Cherng; Cheng, Ting-Chih; Lou, M Ann; Hsu, Giu-Cheng; Wu, Chia-Yun; Chen, Sou-Tong; Wu, Hurng-Sheng; Wu, Pei-Ei; Shen, Chen-Yang

2003-05-15

The role of the familial breast cancer susceptibility genes, BRCA1 and BRCA2, in the homologous recombination pathway for DNA double-strand break (DSB) repair suggests that the mechanisms involved in DNA DSB repair are of particular etiological importance during breast tumorigenesis. However, there is currently no evidence for an association between breast cancer and the other DSB repair pathway, the nonhomologous end-joining (NHEJ) pathway. It is possible that, because this DNA repair pathway is so crucial for mammalian cells to maintain genomic stability, any severe defects in it would result in serious outcomes, such as genomic instability and cell death, and block subsequent cell outgrowth and tumor formation. Thus, only subtle defects arising from low-penetrance alleles would escape lethality accumulating essential genetic changes and be associated with cancer formation, and the tumorigenic contribution of these alleles would become more obvious if individual putative high-risk genotypes of each NHEJ gene act jointly. Furthermore, this joint effect might be modified by specific environmental factors, and we hypothesized that estrogen exposure might be one such factor because estrogen is suggested to cause DNA DSBs, triggering breast tumorigenesis. Because single nucleotide polymorphisms (SNPs) are the most subtle genetic variation in the genome, to examine these hypotheses, we have genotyped 30 SNPs in all five NHEJ genes (Ku70, Ku80, DNA-PKcs, Ligase IV, and XRCC4) in 254 primary breast cancer patients and 379 healthy controls. Support for these hypotheses came from the observations that (a) two SNPs in Ku70 and XRCC4 were associated with breast cancer risk (P < 0.05); (b) a trend toward increased risk of developing breast cancer was found in women harboring a greater number of putative high-risk genotypes of NHEJ genes (an adjusted odds ratio of 1.46 for having one additional putative high-risk genotype; 95% confidence interval, 1.19-1.80); (c) this association between risk and the number of putative high-risk genotypes was stronger and more significant in women thought to be more susceptible to estrogen, i.e., those with no history of full-term pregnancy; and (d) the protective effect conferred by a history of full-term pregnancy was only significant in women with a lower number of putative high-risk genotypes of NHEJ genes. Based on comprehensive NHEJ gene profiles, this study provides new insights to suggest the role of the NHEJ pathway in breast cancer development and supports the possibility that breast cancer is initiated by estrogen exposure, which causes DNA DSBs.

Prefrontal mechanisms of behavioral flexibility, emotion regulation and value updating

PubMed Central

Rudebeck, Peter H.; Saunders, Richard C.; Prescott, Anna T.; Chau, Lily S.; Murray, Elisabeth A.

2013-01-01

Two ideas have dominated the neuropsychology of the orbitofrontal cortex (OFC). One holds that OFC regulates emotion and enhances behavioral flexibility through inhibitory control. The other ascribes to OFC a role in updating valuations based on current motivational states. Neuroimaging, neurophysiological and clinical observations are consistent with either or both hypotheses. Although these hypotheses are compatible in principle, the present results support the latter view of OFC function and argue against the former. We show that excitotoxic, fibersparing lesions confined to OFC in monkeys do not alter either behavioral flexibility, as measured by object reversal learning, or emotion regulation, as assessed by snake fear. A follow-up experiment indicates that previous reports of a loss of inhibitory control resulted from damage to nearby fiber tracts and not from OFC dysfunction. Thus, OFC plays a more specialized role in reward-guided behavior and emotion than currently thought, a function that includes value updating. PMID:23792944

Family stress and parental responses to children's negative emotions: tests of the spillover, crossover, and compensatory hypotheses.

PubMed

Nelson, Jackie A; O'Brien, Marion; Blankson, A Nayena; Calkins, Susan D; Keane, Susan P

2009-10-01

The relations between 4 sources of family stress (marital dissatisfaction, home chaos, parental depressive symptoms, and job role dissatisfaction) and the emotion socialization practice of mothers' and fathers' responses to children's negative emotions were examined. Participants included 101 couples with 7-year-old children. Dyadic analyses were conducted using the Actor-Partner Interdependence Model and relations were tested in terms of the spillover, crossover, and compensatory hypotheses. Results suggest that measures of family stress relate to supportive and nonsupportive parental responses, though many of these relations differ by parent gender. The results are discussed in terms of the 3 theoretical hypotheses, all of which are supported to some degree depending on the family stressor examined.

[Decreased A-type potassium current mediates the hyperexcitability of nociceptive neurons in the chronically compressed dorsal root ganglia].

PubMed

Yan, Ni; Li, Xiao-Han; Cheng, Qi; Yan, Jin; Ni, Xin; Sun, Ji-Hu

2007-04-25

The excitability of nociceptive neurons increases in the intact dorsal root ganglion (DRG) after a chronic compression, but the underlying mechanisms are still unclear. The aim of this study was to investigate the ionic mechanisms underlying the hyperexcitability of nociceptive neurons in the compressed ganglion. Chronic compression of DRG (CCD) was produced in adult rats by inserting two rods through the intervertebral foramina to compress the L4 DRG and the ipsilateral L5 DRG. After 5-7 d, DRG somata were dissociated and placed in culture for 12-18 h. In sharp electrode recording model, the lower current threshold and the depolarized membrane potential in the acutely dissociated CCD neurons were detected, indicating that hyperexcitability is intrinsic to the soma. Since voltage-gated K(+) (Kv) channels in the primary sensory neurons are important for the regulation of excitability, we hypothesized that CCD would alter K(+) current properties in the primary sensory neurons. We examined the effects of 4-aminopyridine (4-AP), a specific antagonist of A-type potassium channel, on the excitability of the control DRG neurons. With 4-AP in the external solution, the control DRG neurons depolarized (with discharges in some cells) and their current threshold decreased as the CCD neurons demonstrated, indicating the involvement of decreased A-type potassium current in the hyperexcitability of the injured neurons. Furthermore, the alteration of A-type potassium current in nociceptive neurons in the compressed ganglion was investigated with the whole-cell patch-clamp recording model. CCD significantly decreased A-type potassium current density in nociceptive DRG neurons. These data suggest that a reduction in A-type potassium current contributes, at least in part, to the increase in neuron excitability that may lead to the development of pain and hyperalgesia associated with CCD.

Language of sport fans: sportugese revisited.

PubMed

Wann, D L; Metcalf, L A; Adcock, M L; Choi, C C; Dallas, M B; Slaton, E

1997-12-01

In 1959, Tannenbaum and Noah reported that sports writers and readers possessed a better understanding of sport terminology than nonreaders. The current investigation extended Tannenbaum and Noah's research using current sport terms. A positive relationship between understanding sport terminology, extent of team identification, strength of sport fandom, and self-proclaimed sport knowledge was hypothesized. Scores of 57 participants confirmed the predicted pattern. Discussion concerned research examining sport terminology.

Validity of Memory Tasks across the WJ III COG, NEPSYII, and WRAML-2 in a Mixed Clinical Sample of Children: Applicability to Four Neurocognitive Theories

ERIC Educational Resources Information Center

Psimas, J. Lynsey

2012-01-01

Current research regarding the neurocognitive construct of memory in children and adolescents within clinical populations is insufficient (Hughes & Graham, 2002). Controversial theories of memory have led to divergent hypotheses about the construct of memory. Based on current disparity regarding the theoretical paradigm of memory, it cannot be…

Metabolic and hemodynamic events following changes in neuronal activity: current hypotheses, theoretical predictions and in vivo NMR experimental findings

PubMed Central

Mangia, Silvia; Giove, Federico; Tkáč, Ivan; Logothetis, Nikos K.; Henry, Pierre-Gilles; Olman, Cheryl A.; Maraviglia, Bruno; Di Salle, Francesco; Uğurbil, Kâmil

2009-01-01

Unraveling the energy metabolism and the hemodynamic outcomes of excitatory and inhibitory neuronal activity is critical not only for our basic understanding of overall brain function, but also for the understanding of many brain disorders. Methodologies of magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) are powerful tools for the non-invasive investigation of brain metabolism and physiology. However, the temporal and spatial resolution of in vivo MRS and MRI is not suitable to provide direct evidence for hypotheses that involve metabolic compartmentalization between different cell types, or to untangle the complex neuronal micro-circuitry which results in changes of electrical activity. This review aims at describing how the current models of brain metabolism, mainly built on the basis of in vitro evidence, relate to experimental findings recently obtained in vivo by 1H MRS, 13C MRS and MRI. The hypotheses related to the role of different metabolic substrates, the metabolic neuron-glia interactions, along with the available theoretical predictions of the energy budget of neurotransmission, will be discussed. In addition, the cellular and network mechanisms that characterize different types of increased and suppressed neuronal activity will be considered within the sensitivity-constraints of MRS and MRI. PMID:19002199

Evolutionary origin and early biogeography of otophysan fishes (Ostariophysi: Teleostei).

PubMed

Chen, Wei-Jen; Lavoué, Sébastien; Mayden, Richard L

2013-08-01

The biogeography of the mega-diverse, freshwater, and globally distributed Otophysi has received considerable attention. This attraction largely stems from assumptions as to their ancient origin, the clade being almost exclusively freshwater, and their suitability as to explanations of trans-oceanic distributions. Despite multiple hypotheses explaining present-day distributions, problems remain, precluding more parsimonious explanations. Underlying previous hypotheses are alternative phylogenies for Otophysi, uncertainties as to temporal diversification and assumptions integral to various explanations. We reexamine the origin and early diversification of this clade based on a comprehensive time-calibrated, molecular-based phylogenetic analysis and event-based approaches for ancestral range inference of lineages. Our results do not corroborate current phylogenetic classifications of otophysans. We demonstrate Siluriformes are never sister to Gymnotiformes and Characiformes are most likely nonmonophyletic. Divergence time estimates specify a split between Cypriniformes and Characiphysi with the fragmentation of Pangea. The early diversification of characiphysans either predated, or was contemporary with, the separation of Africa and South America, and involved a combination of within- and between-continental divergence events for these lineages. The intercontinental diversification of siluroids and characoids postdated major intercontinental tectonic fragmentations (<90 Mya). Post-tectonic drift dispersal events are hypothesized to account for their current distribution patterns. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Monitoring-induced disruption in skilled typewriting.

PubMed

Snyder, Kristy M; Logan, Gordon D

2013-10-01

It is often disruptive to attend to the details of one's expert performance. The current work presents four experiments that utilized a monitor to report protocol to evaluate the sufficiency of three accounts of monitoring-induced disruption. The inhibition hypothesis states that disruption results from costs associated with preparing to withhold inappropriate responses. The dual-task hypothesis states that disruption results from maintaining monitored information in working memory. The implicit-explicit hypothesis states that disruption results from explicitly monitoring details of performance that are normally implicit. The findings suggest that all three hypotheses are sufficient to produce disruption, but inhibition and dual-task costs are not necessary. Experiment 1 showed that monitoring to report was disruptive even when there was no requirement to inhibit. Experiment 2 showed that maintaining information in working memory caused some disruption but much less than monitoring to report. Experiment 4 showed that monitoring to inhibit was more disruptive than monitoring to report, suggesting that monitoring is more disruptive when it is combined with other task requirements, such as inhibition. PsycINFO Database Record (c) 2013 APA, all rights reserved.

EVENT PREDICTION AND AFFECTIVE FORECASTING IN DEPRESSIVE COGNITION: USING EMOTION AS INFORMATION ABOUT THE FUTURE

PubMed Central

MARROQUÍN, BRETT; NOLEN-HOEKSEMA, SUSAN

2015-01-01

Depression is characterized by a bleak view of the future, but the mechanisms through which depressed mood is integrated into basic processes of future-oriented cognition are unclear. We hypothesized that dysphoric individuals’ predictions of what will happen in the future (likelihood estimation) and how the future will feel (affective forecasting) are attributable to individual differences in incorporating present emotion as judgment-relevant information. Dysphoric individuals (n = 77) made pessimistic likelihood estimates and blunted positive affective forecasts relative to controls (n = 84). These differences were mediated by dysphoric individuals’ tendencies to rely on negative emotion as information more than controls—and on positive emotion less—independent of anhedonia. These findings suggest that (1) blunted positive affective forecasting is a distinctive component of depressive future-oriented cognition, and (2) future-oriented cognitive processes are linked not just to current emotional state, but also to individual variation in using that emotion as information. This role of individual differences elucidates basic mechanisms in future-oriented cognition, and suggests routes for intervention on interrelated cognitive and affective processes in depression. PMID:26146452

Cortical functional connectivity decodes subconscious, task-irrelevant threat-related emotion processing

PubMed Central

Pantazatos, Spiro P.; Talati, Ardesheer; Pavlidis, Paul; Hirsch, Joy

2012-01-01

It is currently unclear to what extent cortical structures are required for and engaged during subconscious processing of biologically salient affective stimuli (i.e. the ‘low-road’ vs. ‘many-roads’ hypotheses). Here we show that cortical-cortical and cortical-subcortical functional connectivity (FC) contain substantially more information, relative to subcortical-subcortical FC (i.e. ‘subcortical alarm’ and other limbic regions), that predicts subliminal fearful face processing within individuals using training data from separate subjects. A plot of classification accuracy vs. number of selected whole-brain FC features revealed 92% accuracy when learning was based on the top 8 features from each training set. The most informative FC was between right amygdala and precuneus, which increased during subliminal fear conditions, while left and right amygdala FC decreased, suggesting a bilateral decoupling of this key limbic region during processing of subliminal fear-related stimuli. Other informative FC included angular gyrus, middle temporal gyrus and cerebellum. These findings identify FC that decodes subliminally perceived, task-irrelevant affective stimuli, and suggest that cortical structures are actively engaged by and appear to be essential for subliminal fear processing. PMID:22484206

Cortical functional connectivity decodes subconscious, task-irrelevant threat-related emotion processing.

PubMed

Pantazatos, Spiro P; Talati, Ardesheer; Pavlidis, Paul; Hirsch, Joy

2012-07-16

It is currently unclear to what extent cortical structures are required for and engaged during subconscious processing of biologically salient affective stimuli (i.e. the 'low-road' vs. 'many-roads' hypotheses). Here we show that cortical-cortical and cortical-subcortical functional connectivity (FC) contain substantially more information, relative to subcortical-subcortical FC (i.e. 'subcortical alarm' and other limbic regions), that predicts subliminal fearful face processing within individuals using training data from separate subjects. A plot of classification accuracy vs. number of selected whole-brain FC features revealed 92% accuracy when learning was based on the top 8 features from each training set. The most informative FC was between right amygdala and precuneus, which increased during subliminal fear conditions, while left and right amygdala FC decreased, suggesting a bilateral decoupling of this key limbic region during processing of subliminal fear-related stimuli. Other informative FC included angular gyrus, middle temporal gyrus and cerebellum. These findings identify FC that decodes subliminally perceived, task-irrelevant affective stimuli, and suggest that cortical structures are actively engaged by and appear to be essential for subliminal fear processing. Published by Elsevier Inc.

Statistical learning of novel graphotactic constraints in children and adults.

PubMed

Samara, Anna; Caravolas, Markéta

2014-05-01

The current study explored statistical learning processes in the acquisition of orthographic knowledge in school-aged children and skilled adults. Learning of novel graphotactic constraints on the position and context of letter distributions was induced by means of a two-phase learning task adapted from Onishi, Chambers, and Fisher (Cognition, 83 (2002) B13-B23). Following incidental exposure to pattern-embedding stimuli in Phase 1, participants' learning generalization was tested in Phase 2 with legality judgments about novel conforming/nonconforming word-like strings. Test phase performance was above chance, suggesting that both types of constraints were reliably learned even after relatively brief exposure. As hypothesized, signal detection theory d' analyses confirmed that learning permissible letter positions (d'=0.97) was easier than permissible neighboring letter contexts (d'=0.19). Adults were more accurate than children in all but a strict analysis of the contextual constraints condition. Consistent with the statistical learning perspective in literacy, our results suggest that statistical learning mechanisms contribute to children's and adults' acquisition of knowledge about graphotactic constraints similar to those existing in their orthography. Copyright © 2013 Elsevier Inc. All rights reserved.

Historical approaches to post-combat disorders.

PubMed

Jones, Edgar

2006-04-29

Almost every major war in the last century involving western nations has seen combatants diagnosed with a form of post-combat disorder. Some took a psychological form (exhaustion, combat fatigue, combat stress reaction and post-traumatic stress disorder), while others were characterized by medically unexplained symptoms (soldier's heart, effort syndrome, shell shock, non-ulcer dyspepsia, effects of Agent Orange and Gulf War Syndrome). Although many of these disorders have common symptoms, the explanations attached to them showed considerable diversity often reflected in the labels themselves. These causal hypotheses ranged from the effects of climate, compressive forces released by shell explosions, side effects of vaccinations, changes in diet, toxic effects of organophosphates, oil-well fires or depleted-uranium munitions. Military history suggests that these disorders, which coexisted in the civilian population, reflected popular health fears and emerged in the gaps left by the advance of medical science. While the current Iraq conflict has yet to produce a syndrome typified by medically unexplained symptoms, it is unlikely that we have seen the last of post-combat disorders as past experience suggests that they have the capacity to catch both military planners and doctors by surprise.

Redefining meaningful age groups in the context of disease.

PubMed

Geifman, Nophar; Cohen, Raphael; Rubin, Eitan

2013-12-01

Age is an important factor when considering phenotypic changes in health and disease. Currently, the use of age information in medicine is somewhat simplistic, with ages commonly being grouped into a small number of crude ranges reflecting the major stages of development and aging, such as childhood or adolescence. Here, we investigate the possibility of redefining age groups using the recently developed Age-Phenome Knowledge-base (APK) that holds over 35,000 literature-derived entries describing relationships between age and phenotype. Clustering of APK data suggests 13 new, partially overlapping, age groups. The diseases that define these groups suggest that the proposed divisions are biologically meaningful. We further show that the number of different age ranges that should be considered depends on the type of disease being evaluated. This finding was further strengthened by similar results obtained from clinical blood measurement data. The grouping of diseases that share a similar pattern of disease-related reports directly mirrors, in some cases, medical knowledge of disease-age relationships. In other cases, our results may be used to generate new and reasonable hypotheses regarding links between diseases.

EVENT PREDICTION AND AFFECTIVE FORECASTING IN DEPRESSIVE COGNITION: USING EMOTION AS INFORMATION ABOUT THE FUTURE.

PubMed

Marroquín, Brett; Nolen-Hoeksema, Susan

2015-02-01

Depression is characterized by a bleak view of the future, but the mechanisms through which depressed mood is integrated into basic processes of future-oriented cognition are unclear. We hypothesized that dysphoric individuals' predictions of what will happen in the future ( likelihood estimation ) and how the future will feel ( affective forecasting ) are attributable to individual differences in incorporating present emotion as judgment-relevant information. Dysphoric individuals ( n = 77) made pessimistic likelihood estimates and blunted positive affective forecasts relative to controls ( n = 84). These differences were mediated by dysphoric individuals' tendencies to rely on negative emotion as information more than controls-and on positive emotion less-independent of anhedonia. These findings suggest that (1) blunted positive affective forecasting is a distinctive component of depressive future-oriented cognition, and (2) future-oriented cognitive processes are linked not just to current emotional state, but also to individual variation in using that emotion as information. This role of individual differences elucidates basic mechanisms in future-oriented cognition, and suggests routes for intervention on interrelated cognitive and affective processes in depression.

The Effect of Noise on the Relationship Between Auditory Working Memory and Comprehension in School-Age Children.

PubMed

Sullivan, Jessica R; Osman, Homira; Schafer, Erin C

2015-06-01

The objectives of the current study were to examine the effect of noise (-5 dB SNR) on auditory comprehension and to examine its relationship with working memory. It was hypothesized that noise has a negative impact on information processing, auditory working memory, and comprehension. Children with normal hearing between the ages of 8 and 10 years were administered working memory and comprehension tasks in quiet and noise. The comprehension measure comprised 5 domains: main idea, details, reasoning, vocabulary, and understanding messages. Performance on auditory working memory and comprehension tasks were significantly poorer in noise than in quiet. The reasoning, details, understanding, and vocabulary subtests were particularly affected in noise (p < .05). The relationship between auditory working memory and comprehension was stronger in noise than in quiet, suggesting an increased contribution of working memory. These data suggest that school-age children's auditory working memory and comprehension are negatively affected by noise. Performance on comprehension tasks in noise is strongly related to demands placed on working memory, supporting the theory that degrading listening conditions draws resources away from the primary task.

Prevalence of Hypertension by Duration and Age at Exposure to the Stroke Belt

PubMed Central

Howard, Virginia J; Woolson, Robert F.; Egan, Brent M.; Nicholas, Joyce S.; Adams, Robert J.; Howard, George; Lackland, Daniel T.

2010-01-01

Background Geographic variation in hypertension is hypothesized as contributing to the stroke belt, an area in southeastern United States with high stroke mortality. No study has examined hypertension by lifetime exposure to the stroke belt. Methods This association was studied in 19 385 participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study, a national population-based cohort. Prevalent hypertension was defined as SBP ≥ 140, DBP ≥ 90, or use of antihypertensive medications. Stroke belt exposure was assessed by residence at birth, currently, early childhood, adolescence, early adulthood, mid-adulthood, and recently. Results After adjustment for age, race, sex, physical activity level, body mass index, smoking, alcohol, education, and income, the prevalence of hypertension was significantly more strongly related (p < 0.0001) with lifetime exposure, adolescence or early adulthood exposure than exposures at other times. Birthplace and current residence were independently associated with hypertension; however, lifetime, adolescence or early adulthood exposures were more predictive than joint model with both birthplace and current residence. Conclusions That adolescence and early adulthood periods are more predictive than residence in the stroke belt for most recent 20-year period suggests community and environmental strategies to prevent hypertension need to start earlier in life. PMID:20374949

Sequence-related amplified polymorphism (SRAP) markers: A potential resource for studies in plant molecular biology(1.).

PubMed

Robarts, Daniel W H; Wolfe, Andrea D

2014-07-01

In the past few decades, many investigations in the field of plant biology have employed selectively neutral, multilocus, dominant markers such as inter-simple sequence repeat (ISSR), random-amplified polymorphic DNA (RAPD), and amplified fragment length polymorphism (AFLP) to address hypotheses at lower taxonomic levels. More recently, sequence-related amplified polymorphism (SRAP) markers have been developed, which are used to amplify coding regions of DNA with primers targeting open reading frames. These markers have proven to be robust and highly variable, on par with AFLP, and are attained through a significantly less technically demanding process. SRAP markers have been used primarily for agronomic and horticultural purposes, developing quantitative trait loci in advanced hybrids and assessing genetic diversity of large germplasm collections. Here, we suggest that SRAP markers should be employed for research addressing hypotheses in plant systematics, biogeography, conservation, ecology, and beyond. We provide an overview of the SRAP literature to date, review descriptive statistics of SRAP markers in a subset of 171 publications, and present relevant case studies to demonstrate the applicability of SRAP markers to the diverse field of plant biology. Results of these selected works indicate that SRAP markers have the potential to enhance the current suite of molecular tools in a diversity of fields by providing an easy-to-use, highly variable marker with inherent biological significance.

Sequence-related amplified polymorphism (SRAP) markers: A potential resource for studies in plant molecular biology1

PubMed Central

Robarts, Daniel W. H.; Wolfe, Andrea D.

2014-01-01

In the past few decades, many investigations in the field of plant biology have employed selectively neutral, multilocus, dominant markers such as inter-simple sequence repeat (ISSR), random-amplified polymorphic DNA (RAPD), and amplified fragment length polymorphism (AFLP) to address hypotheses at lower taxonomic levels. More recently, sequence-related amplified polymorphism (SRAP) markers have been developed, which are used to amplify coding regions of DNA with primers targeting open reading frames. These markers have proven to be robust and highly variable, on par with AFLP, and are attained through a significantly less technically demanding process. SRAP markers have been used primarily for agronomic and horticultural purposes, developing quantitative trait loci in advanced hybrids and assessing genetic diversity of large germplasm collections. Here, we suggest that SRAP markers should be employed for research addressing hypotheses in plant systematics, biogeography, conservation, ecology, and beyond. We provide an overview of the SRAP literature to date, review descriptive statistics of SRAP markers in a subset of 171 publications, and present relevant case studies to demonstrate the applicability of SRAP markers to the diverse field of plant biology. Results of these selected works indicate that SRAP markers have the potential to enhance the current suite of molecular tools in a diversity of fields by providing an easy-to-use, highly variable marker with inherent biological significance. PMID:25202637

Online gaming in the context of social anxiety.

PubMed

Lee, Bianca W; Leeson, Peter R C

2015-06-01

In 2014, over 23 million individuals were playing massive multiplayer online role-playing games (MMORPGs). In light of the framework provided by Davis's (2001) cognitive-behavioral model of pathological Internet use, social anxiety, expressions of true self, and perceived in-game and face-to-face social support were examined as predictors of Generalized Problematic Internet Use Scale (GPIUS) scores and hours spent playing MMORPGs per week. Data were collected from adult MMORPG players via an online survey (N = 626). Using structural equation modeling, the hypothesized model was tested on 1 half of the sample (N = 313) and then retested on the other half of the sample. The results indicated that the hypothesized model fit the data well in both samples. Specifically, expressing true self in game, higher levels of social anxiety, larger numbers of in-game social supports, and fewer supportive face-to-face relationships were significant predictors of higher GPIUS scores, and the number of in-game supports was significantly associated with time spent playing. The current study provides clinicians and researchers with a deeper understanding of MMORPG use by being the first to apply, test, and replicate a theory-driven model across 2 samples of MMORPG players. In addition, the present findings suggest that a psychometric measure of MMORPG usage is more indicative of players' psychological and social well-being than is time spent playing these games. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Improving Adolescent Judgment and Decision Making

PubMed Central

Dansereau, Donald F.; Knight, Danica K.; Flynn, Patrick M.

2013-01-01

Human judgment and decision making (JDM) has substantial room for improvement, especially among adolescents. Increased technological and social complexity “ups the ante” for developing impactful JDM interventions and aids. Current explanatory advances in this field emphasize dual processing models that incorporate both experiential and analytic processing systems. According to these models, judgment and decisions based on the experiential system are rapid and stem from automatic reference to previously stored episodes. Those based on the analytic system are viewed as slower and consciously developed. These models also hypothesize that metacognitive (self-monitoring) activities embedded in the analytic system influence how and when the two systems are used. What is not included in these models is the development of an intersection between the two systems. Because such an intersection is strongly suggested by memory and educational research as the basis of wisdom/expertise, the present paper describes an Integrated Judgment and Decision-Making Model (IJDM) that incorporates this component. Wisdom/expertise is hypothesized to contain a collection of schematic structures that can emerge from the accumulation of similar episodes or repeated analytic practice. As will be argued, in comparisons to dual system models, the addition of this component provides a broader basis for selecting and designing interventions to improve adolescent JDM. Its development also has implications for generally enhancing cognitive interventions by adopting principles from athletic training to create automated, expert behaviors. PMID:24391350

Characterization of the expression patterns of LEAFY/FLORICAULA and NEEDLY orthologs in female and male cones of the conifer genera Picea, Podocarpus, and Taxus: implications for current evo-devo hypotheses for gymnosperms.

PubMed

Vázquez-Lobo, Alejandra; Carlsbecker, Annelie; Vergara-Silva, Francisco; Alvarez-Buylla, Elena R; Piñero, Daniel; Engström, Peter

2007-01-01

The identity of genes causally implicated in the development and evolutionary origin of reproductive characters in gymnosperms is largely unknown. Working within the framework of plant evolutionary developmental biology, here we have cloned, sequenced, performed phylogenetic analyses upon and tested the expression patterns of LEAFY/FLORICAULA and NEEDLY orthologs in reproductive structures from selected species of the conifer genera Picea, Podocarpus, and Taxus. Contrary to expectations based on previous assessments, expression of LFY/FLO and NLY in cones of these taxa was found to occur simultaneously in a single reproductive axis, initially overlapping but later in mutually exclusive primordia and/or groups of developing cells in both female and male structures. These observations directly affect the status of the "mostly male theory" for the origin of the angiosperm flower. On the other hand, comparative spatiotemporal patterns of the expression of these genes suggest a complex genetic regulatory network of cone development, as well as a scheme of functional divergence for LFY/FLO with respect to NLY homologs in gymnosperms, both with clear heterochronic aspects. Results presented in this study contribute to the understanding of the molecular-genetic basis of morphological evolution in conifer cones, and may aid in establishing a foundation for gymnosperm-specific, testable evo-devo hypotheses.

Multi-Phase Solvation Model for Biological Membranes: Molecular Action Mechanism of Amphotericin B.

PubMed

Falcón-González, J M; Jiménez-Domínguez, G; Ortega-Blake, I; Carrillo-Tripp, M

2017-07-11

Amphotericin B (AmB) is still the most effective drug for the treatment of systemic fungal infections in humans. Despite significant theoretical and experimental efforts trying to understand its molecular mechanism of action, the answer has remained elusive. In this work, we present a computational methodology to test the current membrane related hypotheses, namely, transmembrane ion channel, adsorption, and sterol sponge. We use a thermodynamic approach in which we represent the membrane by a multiphase solvation model with atomic detail (MMPSM) and calculate the free energy of transferring the drug between phases with different dielectric properties. Furthermore, we compare AmB to a chemical analogue with increased safety, an l-histidine methyl ester of AmB. Our findings reveal that both drugs dimerize in all solvents studied here. Also, it is energetically unfavorable for the drugs to penetrate into the hydrophobic core of the membrane, unless their concentration is high. Finally, it is thermodynamically possible that the sterols migrate from the membrane into a drug droplet adsorbed at the surface of the bilayer. In light of our results, several effects could take place in the complex antibiotic process. We suggest a molecular mechanism that connects all three hypotheses through a drug concentration dependence and propose that the drug promotes the formation of membrane toroidal pores. Because MMPSM is of general interest, we made it available at http://tripplab.com/tools/mmpsm .

Self-reported concussion history: impact of providing a definition of concussion.

PubMed

Robbins, Clifford A; Daneshvar, Daniel H; Picano, John D; Gavett, Brandon E; Baugh, Christine M; Riley, David O; Nowinski, Christopher J; McKee, Ann C; Cantu, Robert C; Stern, Robert A

2014-01-01

In recent years, the understanding of concussion has evolved in the research and medical communities to include more subtle and transient symptoms. The accepted definition of concussion in these communities has reflected this change. However, it is unclear whether this shift is also reflected in the understanding of the athletic community. Self-reported concussion history is an inaccurate assessment of someone's lifetime exposure to concussive brain trauma. However, unfortunately, in many cases it is the only available tool. We hypothesize that athletes' self-reported concussion histories will be significantly greater after reading them the current definition of concussion, relative to the reporting when no definition was provided. An increase from baseline to post-definition response will suggest that athletes are unaware of the currently accepted medical definition. Cross-sectional study of 472 current and former athletes. Investigators conducted structured telephone interviews with current and former athletes between January 2010 and January 2013, asking participants to report how many concussions they had received in their lives. Interviewers then read participants a current definition of concussion, and asked them to re-estimate based on that definition. THE TWO ESTIMATES WERE SIGNIFICANTLY DIFFERENT (WILCOXON SIGNED RANK TEST: z=15.636, P<0.001). Comparison of the baseline and post-definition medians (7 and 15, respectively) indicated that the post-definition estimate was approximately twice the baseline. Follow-up analyses indicated that this effect was consistent across all levels of competition examined and across type of sport (contact versus non-contact). Our results indicate that athletes' current understandings of concussions are not consistent with a currently accepted medical definition. We strongly recommend that clinicians and researchers preface requests for self-reported concussion history with a definition. In addition, it is extremely important that researchers report the definition they used in published manuscripts of their work. Our study shows that unprompted reporting of concussion history produces results that are significantly different from those provided after a definition has been given, suggesting one possible mechanism to improve the reliability of self-reported concussion history across multiple individuals.

Organizational Effectiveness in Libraries: A Review and Some Suggestions.

ERIC Educational Resources Information Center

Aversa, Elizabeth

1981-01-01

Reviews some approaches to organizational effectiveness suggested by organizational theorists, reports on the applications of these theories in libraries, develops some hypotheses regarding the assessment of performance in libraries, and describes a model which synthesizes some of the approaches. A 52-item reference list is attached. (Author/JL)

New strategies for drug discovery in tropical forests based on ethnobotanical and chemical ecological studies.

PubMed

Albuquerque, Ulysses Paulino; Ramos, Marcelo Alves; Melo, Joabe Gomes

2012-03-06

Hypotheses from ethnobotany and chemical ecology can increase our ability to predict the pharmaceutical potential of tropical flora. In order to illustrate how bioprospecting studies can benefit from the incorporation of these hypotheses, especially in tropical dry forests, we discuss evidence from ethnobotanical studies that examine hypotheses about the ecology of plant defense against herbivory. We focus on two hypotheses regarding defense patterns in plants-the plant apparency hypothesis and the resource availability hypothesis-and analyze how these can help us understand the use of medicinal plants by traditional communities. The evidence suggests that medicinal plants in the dry forest are a rich source of drugs in which phenolic compounds, especially tannins, are directly responsible for the therapeutic activity. Phenolic compounds and their potential therapeutic activity are likely good candidates for bioprospecting efforts. We believe that following strategies to link ethnobotanical and chemical ecological approaches will increase the efficiency of bioprospecting studies in tropical forests. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Geologic map of the Agnesi quadrangle (V-45), Venus

USGS Publications Warehouse

Hansen, Vicki L.; Tharalson, Erik R.

2014-01-01

Two general classes of hypotheses have emerged to address the near random spatial distribution of ~970 apparently pristine impact craters across the surface of Venus: (1) catastrophic/episodic resurfacing and (2) equilibrium/evolutionary resurfacing. Catastrophic/episodic hypotheses propose that a global-scale, temporally punctuated event or events dominated Venus’ evolution and that the generally uniform impact crater distribution (Schaber and others, 1992; Phillips and others, 1992; Herrick and others, 1997) reflects craters that accumulated during relative global quiescence since that event (for example, Strom and others, 1994; Herrick, 1994; Turcotte and others, 1999). Equilibrium/evolutionary hypotheses suggest instead that the near random crater distribution results from relatively continuous, but spatially localized, resurfacing in which volcanic and (or) tectonic processes occur across the planet through time, although the style of operative processes may have varied temporally and spatially (for example, Phillips and others, 1992; Guest and Stofan, 1999; Hansen and Young, 2007). Geologic relations within the map area allow us to test the catastrophic/episodic versus equilibrium/evolutionary resurfacing hypotheses.

I Am Aware of My Inconsistencies but Can Tolerate Them: The Effect of High Quality Listening on Speakers' Attitude Ambivalence.

PubMed

Itzchakov, Guy; Kluger, Avraham N; Castro, Dotan R

2017-01-01

We examined how listeners characterized by empathy and a non-judgmental approach affect speakers' attitude structure. We hypothesized that high quality listening decreases speakers' social anxiety, which in turn reduces defensive processing. This reduction in defensive processing was hypothesized to result in an awareness of contradictions (increased objective-attitude ambivalence), and decreased attitude extremity. Moreover, we hypothesized that experiencing high quality listening would enable speakers to tolerate contradictory responses, such that listening would attenuate the association between objective- and subjective-attitude ambivalence. We obtained consistent support for our hypotheses across four laboratory experiments that manipulated listening experience in different ways on a range of attitude topics. The effects of listening on objective-attitude ambivalence were stronger for higher dispositional social anxiety and initial objective-attitude ambivalence (Study 4). Overall, the results suggest that speakers' attitude structure can be changed by a heretofore unexplored interpersonal variable: merely providing high quality listening.

Diagnosis by integrating model-based reasoning with knowledge-based reasoning

NASA Technical Reports Server (NTRS)

Bylander, Tom

1988-01-01

Our research investigates how observations can be categorized by integrating a qualitative physical model with experiential knowledge. Our domain is diagnosis of pathologic gait in humans, in which the observations are the gait motions, muscle activity during gait, and physical exam data, and the diagnostic hypotheses are the potential muscle weaknesses, muscle mistimings, and joint restrictions. Patients with underlying neurological disorders typically have several malfunctions. Among the problems that need to be faced are: the ambiguity of the observations, the ambiguity of the qualitative physical model, correspondence of the observations and hypotheses to the qualitative physical model, the inherent uncertainty of experiential knowledge, and the combinatorics involved in forming composite hypotheses. Our system divides the work so that the knowledge-based reasoning suggests which hypotheses appear more likely than others, the qualitative physical model is used to determine which hypotheses explain which observations, and another process combines these functionalities to construct a composite hypothesis based on explanatory power and plausibility. We speculate that the reasoning architecture of our system is generally applicable to complex domains in which a less-than-perfect physical model and less-than-perfect experiential knowledge need to be combined to perform diagnosis.

[An approach to the executive functions in autism spectrum disorder].

PubMed

Martos-Pérez, Juan; Paula-Pérez, Isabel

2011-03-01

The psychological hypothesis of executive dysfunction plays a crucial role in explaining the behavioural phenotype of persons with autism spectrum disorders (ASD), along with other hypotheses such as the deficit in the theory of mind or the weak central coherence hypothesis. Yet, none of these hypotheses are mutually exclusive and behaviours that have their origins in one of these three hypotheses are also shaped and upheld by other processes and factors. This article reviews the behavioural manifestation and current state of research on the executive functions in persons with ASD. It also examines its impact on planning, mental flexibility and cognitive skills, generativity, response inhibition, mentalist skills and sense of activity. Although executive dysfunction has become more significant as a hypothesis explaining persons with ASD, there remain some important difficulties in need of further, more detailed research. Moreover, very few intervention programmes have been proved to be effective in minimising the effects of executive dysfunction in autism.

Dark traits and suicide: Associations between psychopathy, narcissism, and components of the interpersonal-psychological theory of suicide.

PubMed

Harrop, Tiffany M; Preston, Olivia C; Khazem, Lauren R; Anestis, Michael D; Junearick, Regis; Green, Bradley A; Anestis, Joye C

2017-10-01

Studies have identified independent relationships between psychopathy, narcissism, and suicidality. The current study expands upon the extant literature by exploring psychopathic and narcissistic personality traits and components of the interpersonal-psychological theory of suicide, utilizing a 3-factor model of psychopathy and 2-factor model of pathological narcissism in community, undergraduate, and military individuals. We hypothesized that the impulsive-antisocial facets of psychopathy would be related to suicidal desire, whereas all facets of psychopathy would relate to the capability for suicide. We anticipated an association between pathological narcissism, thwarted belongingness, and capability for suicide, but not perceived burdensomeness. We further hypothesized a relationship between physical pain tolerance and persistence and the affective (i.e., callousness) facet of psychopathy. Results partially supported these hypotheses and underscore the need for further examination of these associations utilizing contemporary models of psychopathy and narcissism. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Origin and evolution of planetary atmospheres

NASA Technical Reports Server (NTRS)

Pollack, J. B.; Yung, Y. L.

1980-01-01

The current understanding of the origin and evolution of the atmospheres of solar system objects is reviewed. Physical processes that control this evolution are described in an attempt to develop a set of general principles that can help guide studies of specific objects. Particular emphasis is placed on the planetary and satellite atmospheres of the inner solar system objects; current hypotheses on the origin and evolution of these objects are critically considered.

Intracranial Pressure and Its Relationship to Glaucoma: Current Understanding and Future Directions

PubMed Central

ROY CHOWDHURY, Uttio; FAUTSCH, Michael P.

2015-01-01

Retrospective and prospective studies looking at the role of cerebrospinal fluid pressure (CSFP)/intracranial pressure (ICP) have stimulated new theories and hypotheses regarding the underlying causal events for glaucoma. Most recently, studies supporting a low CSFP/ICP as a risk factor for glaucoma have been published. This review summarizes the current understanding of CSFP/ICP and its potential role in the pathogenicity of the disease. PMID:27350948

Transfer of Information from Short- to Long-Term Memory

ERIC Educational Resources Information Center

Modigliani, Vito; Seamon, John G.

1974-01-01

The present study examined current hypotheses concerning information transfer from short-term memory (STM) to long-term memory (LTM) using a Peterson STM task with word triplets presented over retention intervals of 0, 3, 6, 9, and 18 sec. (Editor)

TRICHLOROETHYLENE IHIBITS VOLTAGE-SENSITIVE CALCIUM CURRENTS IN DIFFERENTIATED PC 12 CELLS.

EPA Science Inventory

ABSTRACT BODY: It has been demonstrated recently that volatile organic compounds (VOCs)such as toluene, perchloroethylene and trichloroethylene inhibit function of voltage-sensitive calcium channels (VSSC). Such actions are hypothesized to contribute to the acute neurotoxicity of...

Predicting General Aviation Accident Frequency From Pilot Total Flight Hours

DOT National Transportation Integrated Search

2012-10-01

Craig (2001) hypothesized a killing zonea range of pilot total flight hours (TFH) from about 50-350, over : which general aviation (GA) pilots are at greatest risk. The current work tested a number of candidate modeling : functions on eight ...

Biological determination of mental disorders: a discussion based on recent hypotheses from neuroscience.

PubMed

Freitas-Silva, Luna Rodrigues; Ortega, Francisco

2016-08-29

Understanding the processes involved in the development of mental disorders has proven challenging ever since psychiatry was founded as a field. Neuroscience has provided new expectations that an explanation will be found for the development of mental disorders based on biological functioning alone. However, such a goal has not been that easy to achieve, and new hypotheses have begun to appear in neuroscience research. In this article we identify epigenetics, neurodevelopment, and plasticity as the principal avenues for a new understanding of the biology of mental phenomena. Genetic complexity, the environment's formative role, and variations in vulnerability involve important changes in the principal hypotheses on biological determination of mental disorders, suggesting a reconfiguration of the limits between the "social" and the "biological" in neuroscience research.

Family Stress and Parental Responses to Children’s Negative Emotions: Tests of the Spillover, Crossover, and Compensatory Hypotheses

PubMed Central

Nelson, Jackie A.; O’Brien, Marion; Blankson, A. Nayena; Calkins, Susan D.; Keane, Susan P.

2010-01-01

The relations between 4 sources of family stress (marital dissatisfaction, home chaos, parental depressive symptoms, and job role dissatisfaction) and the emotion socialization practice of mothers’ and fathers’ responses to children’s negative emotions were examined. Participants included 101 couples with 7-year-old children. Dyadic analyses were conducted using the Actor–Partner Interdependence Model and relations were tested in terms of the spillover, crossover, and compensatory hypotheses. Results suggest that measures of family stress relate to supportive and nonsupportive parental responses, though many of these relations differ by parent gender. The results are discussed in terms of the 3 theoretical hypotheses, all of which are supported to some degree depending on the family stressor examined. PMID:19803603

Harmonizing Biodiversity Conservation and Productivity in the Context of Increasing Demands on Landscapes

PubMed Central

Seppelt, Ralf; Beckmann, Michael; Ceauşu, Silvia; Cord, Anna F.; Gerstner, Katharina; Gurevitch, Jessica; Kambach, Stephan; Klotz, Stefan; Mendenhall, Chase; Phillips, Helen R. P.; Powell, Kristin; Verburg, Peter H.; Verhagen, Willem; Winter, Marten; Newbold, Tim

2016-01-01

Abstract Biodiversity conservation and agricultural production are often seen as mutually exclusive objectives. Strategies for reconciling them are intensely debated. We argue that harmonization between biodiversity conservation and crop production can be improved by increasing our understanding of the underlying relationships between them. We provide a general conceptual framework that links biodiversity and agricultural production through the separate relationships between land use and biodiversity and between land use and production. Hypothesized relationships are derived by synthesizing existing empirical and theoretical ecological knowledge. The framework suggests nonlinear relationships caused by the multifaceted impacts of land use (composition, configuration, and intensity). We propose solutions for overcoming the apparently dichotomous aims of maximizing either biodiversity conservation or agricultural production and suggest new hypotheses that emerge from our proposed framework. PMID:29599534

Recalled peer relationship experiences and current levels of self-criticism and self-reassurance.

PubMed

Kopala-Sibley, Daniel C; Zuroff, David C; Leybman, Michelle J; Hope, Nora

2013-03-01

Numerous studies have shown that personality factors may increase or decrease individuals' vulnerability to depression, but little research has examined the role of peer relationships in the development of these factors. Accordingly, this study examined the role of recalled parenting and peer experiences in the development of self-criticism and self-reassurance. It was hypothesized that, controlling for recalled parenting behaviours, specific recalled experiences of peer relationships would be related to current levels of specific forms of self-criticism and self-reassurance. Hypotheses were tested using a retrospective design in which participants were asked to recall experiences of parenting and peer relationships during early adolescence. This age was chosen as early adolescence has been shown to be a critical time for the development of vulnerability to depression. A total of 103 female and 97 male young adults completed measures of recalled parenting, overt and relational victimization and prosocial behaviour by peers, and current levels of self-criticism and self-reassurance. Hierarchical regression analyses showed that parents and peers independently contributed to the development of self-criticism and self-reassurance. Specifically, controlling for parental care and control, overt victimization predicted self-hating self-criticism, relational victimization predicted inadequacy self-criticism, and prosocial behaviour predicted self-reassurance. As well, prosocial behaviour buffered the effect of overt victimization on self-reassurance. Findings highlight the importance of peers in the development of personality risk and resiliency factors for depression, and suggest avenues for interventions to prevent the development of depressive vulnerabilities in youth. The nature of a patient's personality vulnerability to depression may be better understood through a consideration of the patient's relationships with their peers as well as with parents during adolescence. An understanding of adult patients' past peer relationships may further the therapist's understanding of the client's core schemas and dysfunctional attitudes, as well as potential transference reactions during therapy. Identifying and helping youth to better cope with peer victimization may help prevent the development of a vulnerable personality style in adulthood. Fostering positive peer relationships in adolescence may buffer the effects of other more negative relationships with peers. © 2011 The British Psychological Society.

Right wing authoritarianism is associated with race bias in face detection

PubMed Central

Bret, Amélie; Beffara, Brice; McFadyen, Jessica; Mermillod, Martial

2017-01-01

Racial discrimination can be observed in a wide range of psychological processes, including even the earliest phases of face detection. It remains unclear, however, whether racially-biased low-level face processing is influenced by ideologies, such as right wing authoritarianism or social dominance orientation. In the current study, we hypothesized that socio-political ideologies such as these can substantially predict perceptive racial bias during early perception. To test this hypothesis, 67 participants detected faces within arrays of neutral objects. The faces were either Caucasian (in-group) or North African (out-group) and either had a neutral or angry expression. Results showed that participants with higher self-reported right-wing authoritarianism were more likely to show slower response times for detecting out- vs. in-groups faces. We interpreted our results according to the Dual Process Motivational Model and suggest that socio-political ideologies may foster early racial bias via attentional disengagement. PMID:28692705

Mitigating Physiological Responses to Layoff Threat: An Experimental Test of the Efficacy of Two Coping Interventions

PubMed Central

Probst, Tahira M.; Jiang, Lixin

2016-01-01

The purpose of the current study was to assess real-time physiological reactions to the threat of layoffs and to determine whether the use of an emotion-focused vs. problem-focused coping intervention would be more efficacious in attenuating these physiological reactions. A 2 (coping intervention) × 4 (within-subjects time points) mixed experimental design was used to test the hypotheses. Eighty-four undergraduates participated in this laboratory experiment during which their galvanic skin response (GSR) and heart rate (HR) were continuously monitored. Analyses indicate that individuals instructed to utilize an emotion-focused coping strategy experienced a significantly greater decline in their GSR compared to those utilizing the problem-focused coping method. Results suggest organizations conducting layoffs might focus first on dealing with the emotional aftermath of downsizing before focusing on problem-solving tasks, such as resume writing and other traditional outplacement activities. PMID:26999186

Generalized anxiety disorder and social anxiety disorder in youth: are they distinguishable?

PubMed

Whitmore, Maria J; Kim-Spoon, Jungmeen; Ollendick, Thomas H

2014-08-01

The current study was designed to examine diagnostic validity of social anxiety disorder (SOC) and generalized anxiety disorder (GAD) in youth, and implications of comorbidity of the disorders for nosology. Children (n = 130) with SOC, GAD, or both disorders (COMORBID) and their parents were administered diagnostic interviews and self-report measures. Confirmatory factor analyses (CFAs) and ANOVAs were performed for the three groups (SOC, GAD, COMORBID). Second-order CFAs for both parent and child informants suggested that SOC and GAD are two specific facets of a general anxiety factor. ANOVA analyses revealed the two pure groups differed only on parent-reported SOC symptoms and GAD worry symptoms, as hypothesized. COMORBID children had higher scores than SOC group on parent-reported GAD symptoms, worry, and behavioral inhibition, and COMORBID children had higher scores than GAD group on parent-reported SOC symptoms and social anxiety. Results may have implications for assessment of GAD and SOC.

Social Anxiety and Biased Recall of Positive Information: It's Not the Content, It's the Valence.

PubMed

Glazier, Brianne L; Alden, Lynn E

2017-07-01

Cognitive theorists hypothesize that individuals with social anxiety are prone to memory biases such that event recall becomes more negative over time. With few exceptions, studies have focused primarily on changes in negative self-judgments. The current study examined whether memory for positive social events is also subject to recall bias. Undergraduate participants (N = 138) engaged in an unexpected public speaking task and received standardized positive or neutral feedback on their performance. They rated their memory of the received feedback following a 5-minute delay and again 1 week later. Results revealed that higher scores on social anxiety symptoms predicted significant reductions in the recalled valence of positive feedback over time, whereas no changes were observed for neutral feedback. The results suggest that social anxiety may lead to erosion in memory of positive events. Copyright © 2016. Published by Elsevier Ltd.

The role of age in understanding the psychological effects of racism for African Americans.

PubMed

Greer, Tawanda M; Spalding, Abby

2017-10-01

The purpose of the current study was to test age as a moderator of the effects of types of racism on psychological symptoms for a sample of 184 African American women. We hypothesized that increased age would be associated with greater severity in psychological symptoms in relation to exposure to types of racism. Moderated hierarchical regression analyses were performed to test our hypothesis. Findings revealed significant interactions between institutional racism and age in predicting anxiety. Younger women experienced more severe anxiety in relation to greater exposure to institutional racism compared to older African American women. Findings suggest that older age may function as a buffer to psychological outcomes related to racism exposure. Additional studies are needed to understand the ways in which older African American adults cope with racism-related experiences. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Motivated prediction of future feelings: effects of negative mood and mood orientation on affective forecasts.

PubMed

Buehler, Roger; McFarland, Cathy; Spyropoulos, Vassili; Lam, Kent C H

2007-09-01

This article examines the role of motivational factors in affective forecasting. The primary hypothesis was that people predict positive emotional reactions to future events when they are motivated to enhance their current feelings. Three experiments manipulated participants' moods (negative vs. neutral) and orientation toward their moods (reflective vs. ruminative) and then assessed the positivity of their affective predictions for future events. As hypothesized, when participants adopted a reflective orientation, and thus should have been motivated to engage in mood-regulation processes, they predicted more positive feelings in the negative than in the neutral mood condition. This pattern of mood-incongruent affective prediction was not exhibited when participants adopted a ruminative orientation. Additionally, within the negative mood condition, generating affective forecasts had a more positive emotional impact on reflectors than on ruminators. The findings suggest that affective predictions are sometimes driven by mood-regulatory motives.

Attitudes toward sex, arousal, and the retention of contraceptive information.

PubMed

Goldfarb, L; Gerrard, M; Gibbons, F X; Plante, T

1988-10-01

Previous research has suggested that women with a negative emotional orientation toward sexuality (i.e., erotophobia) have difficulty learning and retaining sexually relevant material such as contraceptive information. It has been hypothesized that these women become aroused by this material and that this arousal interferes with their ability to learn it. The importance of this issue led us to conduct the current study. Erotophobic and erotophilic women viewed presentations about contraception while their physiological responses were being monitored. In addition, they were tested on the information contained in the presentation before, immediately after, and again 4-6 weeks after the presentation. The results indicated that the erotophobic women knew less contraceptive information before the presentation and were more aroused by the presentation. This arousal, however, did not interfere with retention of the material. These results are discussed in terms of individual differences in reactions to sexual material and the ability to learn, retain, and use contraceptive information.

Pineal Calcification, Melatonin Production, Aging, Associated Health Consequences and Rejuvenation of the Pineal Gland.

PubMed

Tan, Dun Xian; Xu, Bing; Zhou, Xinjia; Reiter, Russel J

2018-01-31

The pineal gland is a unique organ that synthesizes melatonin as the signaling molecule of natural photoperiodic environment and as a potent neuronal protective antioxidant. An intact and functional pineal gland is necessary for preserving optimal human health. Unfortunately, this gland has the highest calcification rate among all organs and tissues of the human body. Pineal calcification jeopardizes melatonin's synthetic capacity and is associated with a variety of neuronal diseases. In the current review, we summarized the potential mechanisms of how this process may occur under pathological conditions or during aging. We hypothesized that pineal calcification is an active process and resembles in some respects of bone formation. The mesenchymal stem cells and melatonin participate in this process. Finally, we suggest that preservation of pineal health can be achieved by retarding its premature calcification or even rejuvenating the calcified gland.

Dimensions of parenting among mothers and fathers in relation to social anxiety among female adolescents.

PubMed

Bynion, Teah-Marie; Blumenthal, Heidemarie; Bilsky, Sarah A; Cloutier, Renee M; Leen-Feldner, Ellen W

2017-10-01

Social anxiety is the most common anxiety disorder among youth; theoretical and empirical work suggest specific parenting behaviors may be relevant. However, findings are inconsistent, particularly in terms of maternal as compared to paternal effects. In the current study, we evaluated the indirect effects of perceived psychological control on the relation between anxious rearing behaviors and child social anxiety among 112 community-recruited girls (ages 12-15 years). In addition to self-report, adolescent participants completed a laboratory-based social stress task. In line with hypotheses, results indicated indirect effects of psychological control on the relation between anxious rearing behaviors and child social anxiety in maternal but not paternal models. Findings are discussed in terms of their theoretical and empirical implications for clarifying the role of parental relations in adolescent social anxiety. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Retirement and drinking outcomes: lingering effects of workplace stress?

PubMed

Richman, Judith A; Zlatoper, Kenneth W; Zackula Ehmke, Jennifer L; Rospenda, Kathleen M

2006-05-01

This study assesses the degree to which sexual harassment (SH), generalized workplace abuse (GWA), and psychological workload (PWL) impact drinking behaviors in retirement. A mail survey was completed at four points in time by a cohort of 1654 employees initially drawn from a university workplace. Questionnaires assessed experiences of SH, GWA, PWL and drinking behaviors. Hypotheses were tested involving (1) the extent to which SH, GWA, and PWL experienced while working were associated with frequency and quantity of drinking in retirement, (2) the extent to which drinking levels of retirees differed from those of current employees experiencing similar stress levels, and (3) the extent to which gender moderated these relationships. Retirees reporting earlier stressful work environments report higher levels of alcohol consumption during retirement compared to those retirees reporting less stressful earlier work environments. Gender moderated these relationships. The findings of this study suggest that there may be a residual effect of workplace stress during retirement.

Expectancy-related changes in firing of dopamine neurons depend on orbitofrontal cortex.

PubMed

Takahashi, Yuji K; Roesch, Matthew R; Wilson, Robert C; Toreson, Kathy; O'Donnell, Patricio; Niv, Yael; Schoenbaum, Geoffrey

2011-10-30

The orbitofrontal cortex has been hypothesized to carry information regarding the value of expected rewards. Such information is essential for associative learning, which relies on comparisons between expected and obtained reward for generating instructive error signals. These error signals are thought to be conveyed by dopamine neurons. To test whether orbitofrontal cortex contributes to these error signals, we recorded from dopamine neurons in orbitofrontal-lesioned rats performing a reward learning task. Lesions caused marked changes in dopaminergic error signaling. However, the effect of lesions was not consistent with a simple loss of information regarding expected value. Instead, without orbitofrontal input, dopaminergic error signals failed to reflect internal information about the impending response that distinguished externally similar states leading to differently valued future rewards. These results are consistent with current conceptualizations of orbitofrontal cortex as supporting model-based behavior and suggest an unexpected role for this information in dopaminergic error signaling.

Attention: oscillations and neuropharmacology.

PubMed

Deco, Gustavo; Thiele, Alexander

2009-08-01

Attention is a rich psychological and neurobiological construct that influences almost all aspects of cognitive behaviour. It enables enhanced processing of behaviourally relevant stimuli at the expense of irrelevant stimuli. At the cellular level, rhythmic synchronization at local and long-range spatial scales complements the attention-induced firing rate changes of neurons. The former is hypothesized to enable efficient communication between neuronal ensembles tuned to spatial and featural aspects of the attended stimulus. Recent modelling studies suggest that the rhythmic synchronization in the gamma range may be mediated by a fine balance between N-methyl-D-aspartate and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate postsynaptic currents, whereas other studies have highlighted the possible contribution of the neuromodulator acetylcholine. This review summarizes some recent modelling and experimental studies investigating mechanisms of attention in sensory areas and discusses possibilities of how glutamatergic and cholinergic systems could contribute to increased processing abilities at the cellular and network level during states of top-down attention.

Sodium and potassium in the lunar atmosphere

NASA Technical Reports Server (NTRS)

Potter, A. E.; Morgan, T. H.

1991-01-01

The discovery that sodium and potassium vapor can be observed in the lunar atmosphere using ground-based telescopes has opened up a field of investigation that was closed after the last Apollo mission to the Moon. Sodium has been detected at altitudes up to 1500 km above the surface. This implies a high effective temperature for sodium, of the order of 1000 K. However, there is some evidence for two populations of sodium and potassium, one at temperatures corresponding to the surface, and another corresponding to high temperatures. The sources for the lunar atmosphere are not understood. Meteoric bombardment of the surface, solar wind sputtering of the surface, and photo-sputtering of the surface have all been suggested as possible sources for the lunar atmosphere. One of the objectives of the current research is to test different hypotheses by measurements of the atmosphere under different conditions of solar illumination and shielding from the solar wind by the Earth.

The faculty of language: what is it, who has it, and how did it evolve?

PubMed

Hauser, Marc D; Chomsky, Noam; Fitch, W Tecumseh

2002-11-22

We argue that an understanding of the faculty of language requires substantial interdisciplinary cooperation. We suggest how current developments in linguistics can be profitably wedded to work in evolutionary biology, anthropology, psychology, and neuroscience. We submit that a distinction should be made between the faculty of language in the broad sense (FLB) and in the narrow sense (FLN). FLB includes a sensory-motor system, a conceptual-intentional system, and the computational mechanisms for recursion, providing the capacity to generate an infinite range of expressions from a finite set of elements. We hypothesize that FLN only includes recursion and is the only uniquely human component of the faculty of language. We further argue that FLN may have evolved for reasons other than language, hence comparative studies might look for evidence of such computations outside of the domain of communication (for example, number, navigation, and social relations).

Parents of adolescents with psychiatric disorders: insight into the disorder, self-stigma and parental stress.

PubMed

Hasson-Ohayon, Ilanit; Tuval-Mashiach, Rivka; Morag-Yaffe, Mayad; Gaziel, Meyrav; Schapir, Lior; Zalsman, Gil; Shoval, Gal

2014-07-01

Parents of adolescents with mental disorders experience stress partially due to the way they perceive and experience their offspring's disorder. The current study assessed the mediator role of self-stigma in the relationship between insight into the disorder and parental stress of parents of adolescents with mental disorders. A total of 37 parents of adolescents with psychiatric disorders were assessed for their level of insight, self-stigma and parental stress. The hypothesized mediation model was confirmed and is consistent with previous study on parents of adults with severe mental illness. The positive association between insight and parental stress is mediated by these parents' self-stigma, suggesting that insight increases the self-stigma, which in turn increases the parental stress. These results may have clinical implications with regard to the treatment of the family of adolescents with mental disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

Health risk perception and betel chewing behavior--the evidence from Taiwan.

PubMed

Chen, Chiang-Ming; Chang, Kuo-Liang; Lin, Lin; Lee, Jwo-Leun

2013-11-01

In this study, we provided an empirical examination of the interaction between people's health risk perception and betel chewing. We hypothesized that a better knowledge of possible health risks would reduce both the number of individuals who currently chew betel and the likelihood of those who do not yet chew betel to begin the habit. We constructed a simultaneous equation model with Bayesian two-stage approach to control the endogeneity between betel chewing and risk perception. Using a national survey of 26,684 observations in Taiwan, our study results indicated that better health knowledge reduced the possibility that people would become betel chewers. We also found that, in general, betel chewers have a poorer health risk perception than other population. Overall, the empirical evidence suggested that health authorities could reduce the odds of people becoming betel chewers by improving their knowledge of betel-chewing's harmful effects. © 2013 Elsevier Ltd. All rights reserved.

Metamorphosis of mesothelial cells with active horizontal motility in tissue culture.

PubMed

Nagai, Hirotaka; Chew, Shan Hwu; Okazaki, Yasumasa; Funahashi, Satomi; Namba, Takashi; Kato, Takuya; Enomoto, Atsushi; Jiang, Li; Akatsuka, Shinya; Toyokuni, Shinya

2013-01-01

Mesothelial cells, which have diverse roles in physiology and pathology, constitute the mesothelium along with connective tissue and the basement membrane; the mesothelium serves to shield the somatic cavities. After mesothelial injury, mesothelial cells undergo tissue recovery. However, the mechanism of mesothelial regeneration remains poorly understood. In this study, we used confocal time-lapse microscopy to demonstrate that transformed mesothelial cells (MeT5A) and mouse peritoneal mesothelial cells can randomly migrate between cells in cell culture and in ex vivo tissue culture, respectively. Moreover, peritoneal mesothelial cells changed their morphology from a flattened shape to a cuboidal one prior to the migration. Conversely, MDCKII epithelial cells forming tight cell-cell contacts with one another do not alter the arrangement of adjacent cells during movement. Our evidence complements the current hypotheses of mesothelial regeneration and suggests that certain types of differentiated mesothelial cells undergo morphological changes before initiating migration to repair injured sites.

Dysfunctional Metacognitive Beliefs Are Associated with Decreased Executive Control

PubMed Central

Kraft, Brage; Jonassen, Rune; Stiles, Tore C.; Landrø, Nils. I.

2017-01-01

Dysfunctional metacognitive beliefs (“metacognitions”) and executive control are important factors in mental disorders such as depression and anxiety, but the relationship between these concepts has not been studied systematically. We examined whether there is an association between metacognitions and executive control and hypothesized that decreased executive control statistically predicts increased levels of metacognitions. Two hundred and ninety-nine individuals recruited from the general population and outpatient psychiatric clinics completed the Metacognitions Questionnaire-30 and three subtests from the Cambridge Neuropsychological Test Automated Battery corresponding to the three-component model of executive functions. Controlling for current depression and anxiety symptoms, decreased ability to shift between mental sets was associated with increased negative beliefs about the uncontrollability and danger of worry and beliefs about the need to control thoughts. The results suggest a basic association between metacognitions and executive control. Individual differences in executive control could prove important in the personalization of metacognitive therapy. PMID:28469590

The interaction between embodiment and empathy in facial expression recognition

PubMed Central

Jospe, Karine; Flöel, Agnes; Lavidor, Michal

2018-01-01

Abstract Previous research has demonstrated that the Action-Observation Network (AON) is involved in both emotional-embodiment (empathy) and action-embodiment mechanisms. In this study, we hypothesized that interfering with the AON will impair action recognition and that this impairment will be modulated by empathy levels. In Experiment 1 (n = 90), participants were asked to recognize facial expressions while their facial motion was restricted. In Experiment 2 (n = 50), we interfered with the AON by applying transcranial Direct Current Stimulation to the motor cortex. In both experiments, we found that interfering with the AON impaired the performance of participants with high empathy levels; however, for the first time, we demonstrated that the interference enhanced the performance of participants with low empathy. This novel finding suggests that the embodiment module may be flexible, and that it can be enhanced in individuals with low empathy by simple manipulation of motor activation. PMID:29378022

Working Memory and Parent-Rated Components of Attention in Middle Childhood: A Behavioral Genetic Study

PubMed Central

Deater-Deckard, Kirby; Cutting, Laurie; Thompson, Lee A.; Petrill, Stephen A.

2012-01-01

The purpose of the current study was to investigate potential genetic and environmental correlations between working memory and three behavioral aspects of the attention network (i.e., executive, alerting, and orienting) using a twin design. Data were from 90 monozygotic (39% male) and 112 same-sex dizygotic (41% male) twins. Individual differences in working memory performance (digit span) and parent-rated measures of executive, alerting, and orienting attention included modest to moderate genetic variance, modest shared environmental variance, and modest to moderate nonshared environmental variance. As hypothesized, working memory performance was correlated with executive and alerting attention, but not orienting attention. The correlation between working memory, executive attention, and alerting attention was completely accounted for by overlapping genetic covariance, suggesting a common genetic mechanism or mechanisms underlying the links between working memory and certain parent-rated indicators of attentive behavior. PMID:21948215

The future of epigenetic therapy in solid tumours--lessons from the past.

PubMed

Azad, Nilofer; Zahnow, Cynthia A; Rudin, Charles M; Baylin, Stephen B

2013-05-01

The promise of targeting epigenetic abnormalities for cancer therapy has not been realized for solid tumours, although increasing evidence is demonstrating its worth in haematological malignancies. In fact, true clinical efficacy in haematopoietic-related neoplasms has only become evident at low doses of epigenetic-targeting drugs (namely, inhibitors of histone deacetylase and DNA methyltransferases). Describing data from preclinical studies and early clinical trial results, we hypothesize that in using low-dose epigenetic-modulating agents, tumour cells can be reprogrammed, which overrides any immediate cytotoxic and off-target effect observed at high dose. We suggest that such optimization of drug dosing and scheduling of currently available agents could give these agents a prominent place in cancer management--when used alone or in combination with other therapies. If so, optimal use of these known agents might also pave the way for the introduction of other agents that target the epigenome.

Darwin's dilemma: the realities of the Cambrian ‘explosion’

PubMed Central

Conway Morris, Simon

2006-01-01

The Cambrian ‘explosion’ is widely regarded as one of the fulcrum points in the history of life, yet its origins and causes remain deeply controversial. New data from the fossil record, especially of Burgess Shale-type Lagerstätten, indicate, however, that the assembly of bodyplans is not only largely a Cambrian phenomenon, but can already be documented in fair detail. This speaks against a much more ancient origin of the metazoans, and current work is doing much to reconcile the apparent discrepancies between the fossil record, including the Ediacaran assemblages of latest Neoproterozoic age and molecular ‘clocks’. Hypotheses to explain the Cambrian ‘explosion’ continue to be generated, but the recurrent confusion of cause and effect suggests that the wrong sort of question is being asked. Here I propose that despite its step-like function this evolutionary event is the inevitable consequence of Earth and biospheric change. PMID:16754615

Category-specific semantic deficits: the role of familiarity and property type reexamined.

PubMed

Bunn, E M; Tyler, L K; Moss, H E

1998-07-01

Category-specific deficits for living things have been explained variously as an artifact due to differences in the familiarity of concepts in different categories (E. Funnell & J. Sheridan, 1992) or as the result of an underlying impairment to sensory knowledge (E. K. Warrington & T. Shallice, 1984). Efforts to test these hypotheses empirically have been hindered by the shortcomings of currently available stimulus materials. A new set of stimuli are described that the authors developed to overcome the limitations of existing sets. The set consists of color photographs, matched across categories for familiarity and visual complexity. This set was used to test the semantic knowledge of a classic patient, J.B.R. (E. K. Warrington & T. Shallice, 1984). The results suggest that J.B.R.'s deficit for living things cannot be explained in terms of familiarity effects and that the most severely affected categories are those whose identification is most dependent on sensory information.

Detection of infrasound and linear acceleration in fishes.

PubMed

Sand, O; Karlsen, H E

2000-09-29

Fishes have an acute sensitivity to extremely low-frequency linear acceleration, or infrasound, even down to below 1 Hz. The otolith organs are the sensory system responsible for this ability. The hydrodynamic noise generated by swimming fishes is mainly in the infrasound range, and may be important in courtship and prey predator interactions. Intense infrasound has a deterring effect on some species, and has a potential in acoustic barriers. We hypothesize that the pattern of ambient infrasound in the oceans may be used for orientation in migratory fishes, and that pelagic fishes may detect changes in the surface wave pattern associated with altered water depth and distant land formations. We suggest that the acute sensitivity to linear acceleration could be used for inertial guidance, and to detect the relative velocity of layered ocean currents. Sensitivity to infrasound may be a widespread ability among aquatic organisms, and has also been reported in cephalopods and crustaceans.

Detection of infrasound and linear acceleration in fishes.

PubMed Central

Sand, O; Karlsen, H E

2000-01-01

Fishes have an acute sensitivity to extremely low-frequency linear acceleration, or infrasound, even down to below 1 Hz. The otolith organs are the sensory system responsible for this ability. The hydrodynamic noise generated by swimming fishes is mainly in the infrasound range, and may be important in courtship and prey predator interactions. Intense infrasound has a deterring effect on some species, and has a potential in acoustic barriers. We hypothesize that the pattern of ambient infrasound in the oceans may be used for orientation in migratory fishes, and that pelagic fishes may detect changes in the surface wave pattern associated with altered water depth and distant land formations. We suggest that the acute sensitivity to linear acceleration could be used for inertial guidance, and to detect the relative velocity of layered ocean currents. Sensitivity to infrasound may be a widespread ability among aquatic organisms, and has also been reported in cephalopods and crustaceans. PMID:11079418

3D Visualization in Elementary Education Astronomy: Teaching Urban Second Graders about the Sun, Earth, and Moon

NASA Astrophysics Data System (ADS)

Isik-Ercan, Zeynep; Kim, Beomjin; Nowak, Jeffrey

This research-in-progress hypothesizes that urban second graders can have an early understanding about the shape of Sun, Moon, and Earth, how day and night happens, and how Moon appears to change its shape by using three dimensional stereoscopic vision. The 3D stereoscopic vision system might be an effective way to teach subjects like astronomy that explains relationships among objects in space. Currently, Indiana state standards for science teaching do not suggest the teaching of these astronomical concepts explicitly before fourth grade. Yet, we expect our findings to indicate that students can learn these concepts earlier in their educational lives with the implementation of such technologies. We also project that these technologies could revolutionize when these concepts could be taught to children and expand the ways we think about children's cognitive capacities in understanding scientific concepts.

Science, population ecology, and the management of the American black duck

USGS Publications Warehouse

Nichols, J.D.

1991-01-01

This essay deals with the relevance of some of the ideas of Romesburg (1981) to population ecology and management of the American black duck (Anas rubripes). Most investigations dealing with the effects of hunting regulations on black duck populations have used the hypothetico-deductive (H-D) approach of specifying a priori hypotheses and associated deduced predictions. These investigations have not used manipulative experimentation, however, but have involved severely constrained analyses of historical data and have thus produced weak inferences. The 1982 lawsuit over black duck hunting regulations, the current uncertainty about appropriate black duck management actions, and the frequent skirmishes in the published literature of black duck population ecology are natural consequences of these weak inferences. I suggest that we attempt to take advantage of management and other manipulations by treating them as an opportunity to learn something via experimentation, as recommended by Macnab (1983) and Walters (1986).

Running away from unwanted feelings: culture matters.

PubMed

Su, Jenny C; Wei, Meifen; Tsai, Hsiao-Tien

2014-01-01

Findings from past research have suggested a link between experiential avoidance and expressive suppression. However, there is emerging evidence showing that the suppression of emotional expression may have different meanings depending on the specific cultural context. Taking a cultural perspective, the present study aimed to examine whether the link between experiential avoidance and expressive suppression is comparable or divergent between two cultural groups [i.e., European Americans (EAs) and Chinese (CH)] with different cultural norms surrounding emotional expression. We hypothesised that the positive association between experiential avoidance and expressive suppression typically found among EAs would be attenuated among CH. Furthermore, the observed cultural group difference in the experiential avoidance-suppression link was hypothesised to be mediated by beliefs in emotional self-control. Data from 224 EA college students and 190 CH college students provided a clear pattern of support for our hypotheses. Implications for current theories on experiential avoidance are discussed.

Behavioral measures of implicit theory of mind in adults with high functioning autism.

PubMed

Deschrijver, Eliane; Bardi, Lara; Wiersema, Jan R; Brass, Marcel

2016-01-01

Theory of mind (ToM) research has shown that adults with high functioning autism (HFA) demonstrate typical performance on tasks that require explicit belief reasoning, despite clear social difficulties in everyday life situations. In the current study, we used implicit belief manipulations that are task-irrelevant and therefore less susceptible to strategies. In a ball-detection task, it was shown that neurotypical individuals detect a ball faster if an agent believed the ball was present. We predicted that adults with high functioning autism (HFA) would not show this effect. While we found a numerical difference in the hypothesized direction, we did not find a reliable group effect. Interestingly, the implicit ToM-index showed a strong negative correlation with both self-reported and observational measures of social difficulties in the HFA group. This suggests that the relationship between implicit ToM reasoning and the symptomatology of HFA might be subtler than assumed.

Coral mass spawning predicted by rapid seasonal rise in ocean temperature

PubMed Central

Maynard, Jeffrey A.; Edwards, Alasdair J.; Guest, James R.; Rahbek, Carsten

2016-01-01

Coral spawning times have been linked to multiple environmental factors; however, to what extent these factors act as generalized cues across multiple species and large spatial scales is unknown. We used a unique dataset of coral spawning from 34 reefs in the Indian and Pacific Oceans to test if month of spawning and peak spawning month in assemblages of Acropora spp. can be predicted by sea surface temperature (SST), photosynthetically available radiation, wind speed, current speed, rainfall or sunset time. Contrary to the classic view that high mean SST initiates coral spawning, we found rapid increases in SST to be the best predictor in both cases (month of spawning: R2 = 0.73, peak: R2 = 0.62). Our findings suggest that a rapid increase in SST provides the dominant proximate cue for coral mass spawning over large geographical scales. We hypothesize that coral spawning is ultimately timed to ensure optimal fertilization success. PMID:27170709

Auditory Temporal Processing and Working Memory: Two Independent Deficits for Dyslexia

ERIC Educational Resources Information Center

Fostick, Leah; Bar-El, Sharona; Ram-Tsur, Ronit

2012-01-01

Dyslexia is a neuro-cognitive disorder with a strong genetic basis, characterized by a difficulty in acquiring reading skills. Several hypotheses have been suggested in an attempt to explain the origin of dyslexia, among which some have suggested that dyslexic readers might have a deficit in auditory temporal processing, while others hypothesized…

On the use of three hydrological models as hypotheses to investigate the behaviour of a small Mediterranean catchment

NASA Astrophysics Data System (ADS)

Ruiz Pérez, Guiomar; Latron, Jérôme; Llorens, Pilar; Gallart, Francesc; Francés, Félix

2017-04-01

Selecting an adequate hydrological model is the first step to carry out a rainfall-runoff modelling exercise. A hydrological model is a hypothesis of catchment functioning, encompassing a description of dominant hydrological processes and predicting how these processes interact to produce the catchment's response to external forcing. Current research lines emphasize the importance of multiple working hypotheses for hydrological modelling instead of only using a single model. In line with this philosophy, here different hypotheses were considered and analysed to simulate the nonlinear response of a small Mediterranean catchment and to progress in the analysis of its hydrological behaviour. In particular, three hydrological models were considered representing different potential hypotheses: two lumped models called LU3 and LU4, and one distributed model called TETIS. To determine how well each specific model performed and to assess whether a model was more adequate than another, we raised three complementary tests: one based on the analysis of residual errors series, another based on a sensitivity analysis and the last one based on using multiple evaluation criteria associated to the concept of Pareto frontier. This modelling approach, based on multiple working hypotheses, helped to improve our perceptual model of the catchment behaviour and, furthermore, could be used as a guidance to improve the performance of other environmental models.

Testing the Right Target and the Right Drug at the Right Stage

PubMed Central

Sperling, Reisa A.; Jack, Clifford R.; Aisen, Paul S.

2013-01-01

Alzheimer’s disease (AD) is the only leading cause of death for which no disease-modifying therapy is currently available. Recent disappointing trial results at the dementia stage of AD have raised multiple questions about our current approaches to the development of disease-modifying agents. Converging evidence suggests that the pathophysiological process of AD begins many years before the onset of dementia. So why do we keep testing drugs aimed at the initial stages of the disease process in patients at the end-stage of the illness? Alzheimer’s disease (AD) remains one of the most feared consequences of aging, affecting more than one out of every ten individuals over the age of 65. With more than 10,000 baby boomers turning 65 every day in the United States alone, we are truly facing an AD epidemic. Over the past decade, a string of disappointing clinical trial results have raised concerns about our current strategy for development of AD-modifying therapies. Three hypotheses can explain these recent AD trial failures: (i) We are targeting the wrong pathophysiological mechanisms; (ii) The drugs do not engage the intended targets in patients; and (iii) The drugs are hitting the right targets, but are doing so at the wrong stage of the disease. Here, we address the third supposition and suggest that specific amyloid-based therapies be directed at much earlier stages of ADperhaps even prior to the emergence of clinical symptoms. Furthermore, we argue that the field has sufficient tools to begin “secondary prevention” trials in asymptomatic individuals whoare at high risk for progression to cognitive impairment and AD dementia. PMID:22133718

Cannabis withdrawal is common among treatment-seeking adolescents with cannabis dependence and major depression, and is associated with rapid relapse to dependence.

PubMed

Cornelius, Jack R; Chung, Tammy; Martin, Christopher; Wood, D Scott; Clark, Duncan B

2008-11-01

Recently, reports have suggested that cannabis withdrawal occurs commonly in adults with cannabis dependence, though it is unclear whether this extends to those with comorbid depression or to comorbid adolescents. We hypothesized that cannabis withdrawal would be common among our sample of comorbid adolescents and young adults, and that the presence of cannabis withdrawal symptoms would be associated with a self-reported past history of rapid reinstatement of cannabis dependence symptoms (rapid relapse). The participants in this study included 170 adolescents and young adults, including 104 with cannabis dependence, 32 with cannabis abuse, and 34 with cannabis use without dependence or abuse. All of these subjects demonstrated current depressive symptoms and cannabis use, and most demonstrated current DSM-IV major depressive disorder and current comorbid cannabis dependence. These subjects had presented for treatment for either of two double-blind, placebo-controlled trials involving fluoxetine. Cannabis withdrawal was the most commonly reported cannabis dependence criterion among the 104 subjects in our sample with cannabis dependence, being noted in 92% of subjects, using a two-symptom cutoff for determination of cannabis withdrawal. The most common withdrawal symptoms among those with cannabis dependence were craving (82%), irritability (76%), restlessness (58%), anxiety (55%), and depression (52%). Cannabis withdrawal symptoms (in the N=170 sample) were reported to have been associated with rapid reinstatement of cannabis dependence symptoms (rapid relapse). These findings suggest that cannabis withdrawal should be included as a diagnosis in the upcoming DSM-V, and should be listed in the upcoming criteria list for the DSM-V diagnostic category of cannabis dependence.

Preservation of cardiac function by prolonged action potentials in mice deficient of KChIP2.

PubMed

Grubb, Søren; Aistrup, Gary L; Koivumäki, Jussi T; Speerschneider, Tobias; Gottlieb, Lisa A; Mutsaers, Nancy A M; Olesen, Søren-Peter; Calloe, Kirstine; Thomsen, Morten B

2015-08-01

Inherited ion channelopathies and electrical remodeling in heart disease alter the cardiac action potential with important consequences for excitation-contraction coupling. Potassium channel-interacting protein 2 (KChIP2) is reduced in heart failure and interacts under physiological conditions with both Kv4 to conduct the fast-recovering transient outward K(+) current (Ito,f) and with CaV1.2 to mediate the inward L-type Ca(2+) current (ICa,L). Anesthetized KChIP2(-/-) mice have normal cardiac contraction despite the lower ICa,L, and we hypothesized that the delayed repolarization could contribute to the preservation of contractile function. Detailed analysis of current kinetics shows that only ICa,L density is reduced, and immunoblots demonstrate unaltered CaV1.2 and CaVβ₂ protein levels. Computer modeling suggests that delayed repolarization would prolong the period of Ca(2+) entry into the cell, thereby augmenting Ca(2+)-induced Ca(2+) release. Ca(2+) transients in disaggregated KChIP2(-/-) cardiomyocytes are indeed comparable to wild-type transients, corroborating the preserved contractile function and suggesting that the compensatory mechanism lies in the Ca(2+)-induced Ca(2+) release event. We next functionally probed dyad structure, ryanodine receptor Ca(2+) sensitivity, and sarcoplasmic reticulum Ca(2+) load and found that increased temporal synchronicity of the Ca(2+) release in KChIP2(-/-) cardiomyocytes may reflect improved dyad structure aiding the compensatory mechanisms in preserving cardiac contractile force. Thus the bimodal effect of KChIP2 on Ito,f and ICa,L constitutes an important regulatory effect of KChIP2 on cardiac contractility, and we conclude that delayed repolarization and improved dyad structure function together to preserve cardiac contraction in KChIP2(-/-) mice. Copyright © 2015 the American Physiological Society.

Enhanced motor skill acquisition in the non-dominant upper extremity using intermittent theta burst stimulation and transcranial direct current stimulation.

PubMed

Butts, Raymond J; Kolar, Melissa B; Newman-Norlund, Roger D

2014-01-01

Individuals suffering from motor impairments often require physical therapy (PT) to help improve their level of function. Previous investigations suggest that both intermittent theta burst stimulation (iTBS) and bihemispheric transcranial direct current stimulation (tDCS) may increase the speed and extent of motor learning/relearning. The purpose of the current study was to explore the feasibility and effectiveness of a novel, non-invasive brain stimulation approach that combined an iTBS primer, and bihemispheric stimulation coupled with motor training. We hypothesized that individuals exposed to this novel treatment would make greater functional improvements than individuals undergoing sham stimulation when tested immediately following, 24-h, and 7-days post-training. A total of 26 right-handed, healthy young adults were randomly assigned to either a treatment (n = 15) or control group (n = 12). iTBS (20 trains of 10 pulse triplets each delivered at 80% active motor threshold (AMT) / 50 Hz over 191.84 s) and bihemispheric tDCS (1.0 ma for 20 min) were used as a primer to, and in conjunction with, 20 min of motor training, respectively. Our primary outcome measure was performance on the Jebsen-Taylor Hand Function (JTHF) test. Participants tolerated the combined iTBS/bihemispheric stimulation treatment without complaint. While performance gains in the sham and stimulation group were not significant immediately after training, they were nearly significant 24-h post training (p = 0.055), and were significant at 7-days post training (p < 0.05). These results suggest that the combined iTBS/bihemispheric stimulation protocol is both feasible and effective. Future research should examine the mechanistic explanation of this approach as well as the potential of using this approach in clinical populations.

Occupational and Environmental Exposures Associated with Testicular Germ Cell Tumours: Systematic Review of Prenatal and Life-Long Exposures

PubMed Central

Béranger, Rémi; Le Cornet, Charlotte; Schüz, Joachim; Fervers, Béatrice

2013-01-01

Background Testicular germ cell tumours (TGCT) are the most common cancers in men aged between 15 and 44 years and the incidence has increased steeply over the past 30 years. The rapid increase in the incidence, the spatial variation and the evolution of incidence in migrants suggest that environmental risk factors play a role in TGCT aetiology. The purpose of our review is to summarise the current state of knowledge on occupational and environmental factors thought to be associated with TGCT. Methods A systematic literature search of PubMed. All selected articles were quality appraised by two independent researchers using the ‘Newcastle-Ottawa Quality Assessment Scale’. Results After exclusion of duplicate reports, 72 relevant articles were selected; 65 assessed exposure in adulthood, 7 assessed parental exposures and 2 assessed both. Associations with occupation was reported for agricultural workers, construction workers, firemen, policemen, military personnel, as well as workers in paper, plastic or metal industries. Electromagnetic fields, PCBs and pesticides were also suggested. However, results were inconsistent and studies showing positive associations tended to had lower quality ranking using the assessment scale (p=0.02). Discussion Current evidence does not allow concluding on existence of any clear association between TGCT and adulthood occupational or environmental exposure. The limitations of the studies may partly explain the inconsistencies observed. The lack of association with adulthood exposure is in line with current hypotheses supporting the prenatal origin of TGCT. Future research should focus on prenatal or early life exposure, as well as combined effect of prenatal and later life exposure. National and international collaborative studies should allow for more adequately powered epidemiological studies. More sophisticated methods for assessing exposure as well as evaluating gene–environment interactions will be necessary to establish clear conclusion. PMID:24155923

Using Self-affirmation to Increase the Effects of Emotive Health Warnings on Smoking: A Randomized Exploratory Trial.

PubMed

Memish, Kate E; Schüz, Natalie; Frandsen, Mai; Ferguson, Stuart G; Schüz, Benjamin

2017-10-01

Emotive health messages are widely used tools in tobacco control. However, under some circumstances, they can be less effective than desired by eliciting defensive responses in smokers. This study tests whether enhancing a currently used emotive graphic smoking health warning with a self-affirmation component reduces cigarette consumption and whether potential effects are stronger in heavier smokers, as suggested by previous research. Participants (n = 265) were randomly allocated to a self-affirmation (reflecting on personal values and positive traits using a questionnaire) or matched control condition before viewing an emotive graphic health message from a current Australian government public health campaign. The primary outcome (cigarettes per day [CPD]) was assessed both before and a week following the intervention. No main effect of self-affirmation on smoking, but as hypothesized, a significant interaction between baseline smoking and self-affirmation was found that showed that heavier smokers (>21 CPD) who self-affirmed significantly reduced CPD compared to nonaffirmed smokers. These findings support the use of self-affirmation to enhance smoking awareness campaigns in heavier smokers. This study shows that enhancing emotive graphic smoking health messages with self-affirmation (the act of reflecting on positive aspects of oneself) increases their effectiveness in heavier smokers. This suggests that self-affirmation might be a particularly useful tool for health promotion targeting heavier smokers. This study adds to previous research in that it is the first to test the add-on effects of self-affirmation to current graphic health messages on smoking rather than smoking-related cognitions. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Occupational and environmental exposures associated with testicular germ cell tumours: systematic review of prenatal and life-long exposures.

PubMed

Béranger, Rémi; Le Cornet, Charlotte; Schüz, Joachim; Fervers, Béatrice

2013-01-01

Testicular germ cell tumours (TGCT) are the most common cancers in men aged between 15 and 44 years and the incidence has increased steeply over the past 30 years. The rapid increase in the incidence, the spatial variation and the evolution of incidence in migrants suggest that environmental risk factors play a role in TGCT aetiology. The purpose of our review is to summarise the current state of knowledge on occupational and environmental factors thought to be associated with TGCT. A systematic literature search of PubMed. All selected articles were quality appraised by two independent researchers using the 'Newcastle-Ottawa Quality Assessment Scale'. After exclusion of duplicate reports, 72 relevant articles were selected; 65 assessed exposure in adulthood, 7 assessed parental exposures and 2 assessed both. Associations with occupation was reported for agricultural workers, construction workers, firemen, policemen, military personnel, as well as workers in paper, plastic or metal industries. Electromagnetic fields, PCBs and pesticides were also suggested. However, results were inconsistent and studies showing positive associations tended to had lower quality ranking using the assessment scale (p=0.02). Current evidence does not allow concluding on existence of any clear association between TGCT and adulthood occupational or environmental exposure. The limitations of the studies may partly explain the inconsistencies observed. The lack of association with adulthood exposure is in line with current hypotheses supporting the prenatal origin of TGCT. Future research should focus on prenatal or early life exposure, as well as combined effect of prenatal and later life exposure. National and international collaborative studies should allow for more adequately powered epidemiological studies. More sophisticated methods for assessing exposure as well as evaluating gene-environment interactions will be necessary to establish clear conclusion.

Atypical resource allocation may contribute to many aspects of autism

PubMed Central

Goldknopf, Emily J.

2013-01-01

Based on a review of the literature and on reports by people with autism, this paper suggests that atypical resource allocation is a factor that contributes to many aspects of autism spectrum conditions, including difficulties with language and social cognition, atypical sensory and attentional experiences, executive and motor challenges, and perceptual and conceptual strengths and weaknesses. Drawing upon resource theoretical approaches that suggest that perception, cognition, and action draw upon multiple pools of resources, the approach hypothesizes that compared with resources in typical cognition, resources in autism are narrowed or reduced, especially in people with strong sensory symptoms. In narrowed attention, resources are restricted to smaller areas and to fewer modalities, stages of processing, and cognitive processes than in typical cognition; narrowed resources may be more intense than in typical cognition. In reduced attentional capacity, overall resources are reduced; resources may be restricted to fewer modalities, stages of processing, and cognitive processes than in typical cognition, or the amount of resources allocated to each area or process may be reduced. Possible neural bases of the hypothesized atypical resource allocation, relations to other approaches, limitations, and tests of the hypotheses are discussed. PMID:24421760

Detection of hydrodynamic stimuli by the postcranial body of Florida manatees (Trichechus manatus latirostris).

PubMed

Gaspard, Joseph C; Bauer, Gordon B; Mann, David A; Boerner, Katharine; Denum, Laura; Frances, Candice; Reep, Roger L

2017-02-01

Manatees live in shallow, frequently turbid waters. The sensory means by which they navigate in these conditions are unknown. Poor visual acuity, lack of echolocation, and modest chemosensation suggest that other modalities play an important role. Rich innervation of sensory hairs that cover the entire body and enlarged somatosensory areas of the brain suggest that tactile senses are good candidates. Previous tests of detection of underwater vibratory stimuli indicated that they use passive movement of the hairs to detect particle displacements in the vicinity of a micron or less for frequencies from 10 to 150 Hz. In the current study, hydrodynamic stimuli were created by a sinusoidally oscillating sphere that generated a dipole field at frequencies from 5 to 150 Hz. Go/no-go tests of manatee postcranial mechanoreception of hydrodynamic stimuli indicated excellent sensitivity but about an order of magnitude less than the facial region. When the vibrissae were trimmed, detection thresholds were elevated, suggesting that the vibrissae were an important means by which detection occurred. Manatees were also highly accurate in two-choice directional discrimination: greater than 90% correct at all frequencies tested. We hypothesize that manatees utilize vibrissae as a three-dimensional array to detect and localize low-frequency hydrodynamic stimuli.

Disease Suppressive Soils: New Insights from the Soil Microbiome

USDA-ARS?s Scientific Manuscript database

In this review, we will present three currently-studied model systems with features representative of specific and general suppressiveness. Based on these systems, we will consider hypotheses about the fundamental nature of specific and general disease-suppressive soil microbial communities, explore...

Social Relatedness and Autism: Current Research, Issues, Directions.

ERIC Educational Resources Information Center

Walters, Anne S.; And Others

1990-01-01

This literature review focuses on recent studies devoted to hypothesized aspects of social relatedness in autism, discussing attachment and social interest, recognition of and communication of emotions, social cognition, social communication, symbolic play, neuroanatomy of social relatedness, and neurochemistry of social relatedness. (JDD)

Experimenting with Extinction

ERIC Educational Resources Information Center

DeSantis, Larisa; DeSantis, Derek

2017-01-01

This article describes a lesson in which high school biology, ecology, environmental science, anatomy, and physiology students can devise hypotheses and test them with scientific data, identify unanswered questions, and design an additional study to answer those questions. This module connects students with exciting research and current science…

JPRS Report. Science & Technology: Europe.

DTIC Science & Technology

1991-03-29

systems (wind power engines, thermal collectors, etc.). Minister of Research and Technology Hubert Curien and Minister of Public Works, Housing...similar to those currently being manufac- tured in the USSR is being hypothesized, together with studies on the development of the new San Marco Scout

Life Among the Stars

ERIC Educational Resources Information Center

MOSAIC, 1977

1977-01-01

Explores possibility of extra-terrestrial life, reviewing current hypotheses regarding where in space life would most likely occur. Discusses astrometry and spectroscopy as methods for determining stellar motions. Describes United States and Soviet projects for receiving stellar communications. Relates origin of life on earth to observed high…

Research priorities: women in Africa.

PubMed

Okeyo, A P

1979-01-01

In December 1979, an Expert Meeting on Research and Data Collection on Women and Development was convened in Nairobi for the purpose of defining research priorities and methodological approaches for studying the role of African women in development. After reviewing current literature relevant to the subject matter, the participants developed a number of hypotheses regarding the impact of development activities on the role and status of women, and recommended that these hypotheses be tested in future reserach. In general, agrarian reform, mechanization of agriculture, the introduction of cash cropping, and modernization were hypothesized as having a negative impact on the role, status, productive activities, and nutritional standards of women. Other hypotheses stated that development programs and agricultural extension services tended to neglect women. Recommended research methodologies include: 1) efforts to involve the community members in the development and implementation of research projects undertaken in their communities; 2) increased use of local experts and community members in data collection; and 3) interdisciplinary collaboration. The participants also recommended that each country compile a statistical profile on the women in their countries. The profiles should include comparable information on: 1) fertility; 2) educational levels, employment status, and income levels for women; 3) household composition; and 4) types of services available to women.

Incentives and intrinsic motivation in healthcare.

PubMed

Berdud, Mikel; Cabasés, Juan M; Nieto, Jorge

It has been established in the literature that workers within public organisations are intrinsically motivated. This paper is an empirical study of the healthcare sector using methods of qualitative analysis research, which aims to answer the following hypotheses: 1) doctors are intrinsically motivated; 2) economic incentives and control policies may undermine doctors' intrinsic motivation; and 3) well-designed incentives may encourage doctors' intrinsic motivation. We conducted semi-structured interviews à-la-Bewley with 16 doctors from Navarre's Healthcare Service (Servicio Navarro de Salud-Osasunbidea), Spain. The questions were based on current theories of intrinsic motivation and incentives to test the hypotheses. Interviewees were allowed to respond openly without time constraints. Relevant information was selected, quantified and analysed by using the qualitative concepts of saturation and codification. The results seem to confirm the hypotheses. Evidence supporting hypotheses 1 and 2 was gathered from all interviewees, as well as indications of the validity of hypothesis 3 based on interviewees' proposals of incentives. The conclusions could act as a guide to support the optimal design of incentive policies and schemes within health organisations when healthcare professionals are intrinsically motivated. Copyright © 2016 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Hopelessness, individualism, collectivism, and substance use among young rural-to-urban migrants in China.

PubMed

Du, Hongfei; Li, Xiaoming; Lin, Danhua; Tam, Cheuk Chi

2014-01-01

The current study aimed to investigate the impact of individualism, collectivism, and hopelessness on substance use. Hopelessness was hypothesized as a mediator between individualism and substance use, and between collectivism and substance use. We tested the hypothesis using a survey of 641 young rural-to-urban migrants in China. Consistent with our hypotheses, individualistic orientation predicted increased hopelessness and subsequently predicted more substance use, whereas collectivistic orientation was associated with decreased hopelessness and subsequently predicted less substance use. Hopelessness fully mediated the relations between individualism and substance use and between collectivism and substance use. The theoretical and practical implications of these findings were discussed.

Soy-Based Therapeutic Baby Formulas: Testable Hypotheses Regarding the Pros and Cons.

PubMed

Westmark, Cara J

2016-01-01

Soy-based infant formulas have been consumed in the United States since 1909, and currently constitute a significant portion of the infant formula market. There are efforts underway to generate genetically modified soybeans that produce therapeutic agents of interest with the intent to deliver those agents in a soy-based infant formula platform. The threefold purpose of this review article is to first discuss the pros and cons of soy-based infant formulas, then present testable hypotheses to discern the suitability of a soy platform for drug delivery in babies, and finally start a discussion to inform public policy on this important area of infant nutrition.

Migrating songbirds tested in computer-controlled Emlen funnels use stellar cues for a time-independent compass.

PubMed

Mouritsen, H; Larsen, O N

2001-11-01

This paper investigates how young pied flycatchers, Ficedula hypoleuca, and blackcaps, Sylvia atricapilla, interpret and use celestial cues. In order to record these data, we developed a computer-controlled version of the Emlen funnel, which enabled us to make detailed temporal analyses. First, we showed that the birds use a star compass. Then, we tested the birds under a stationary planetarium sky, which simulated the star pattern of the local sky at 02:35 h for 11 consecutive hours of the night, and compared the birds' directional choices as a function of time with the predictions from five alternative stellar orientation hypotheses. The results supported the hypothesis suggesting that birds use a time-independent star compass based on learned geometrical star configurations to pinpoint the rotational point of the starry sky (north). In contrast, neither hypotheses suggesting that birds use the stars for establishing their global position and then perform true star navigation nor those suggesting the use of a time-compensated star compass were supported.

Disgust and Obsessive Beliefs in Contamination-related OCD

PubMed Central

Cisler, Josh M.; Brady, Robert E.; Olatunji, Bunmi O.; Lohr, Jeffrey M.

2010-01-01

A large body of evidence suggests that disgust is an important affective process underlying contamination fear. An independent line of research demonstrates that obsessive beliefs, particularly overestimations of threat, are also an important cognitive process underlying contamination fear. The present study attempts to integrate these two lines of research by testing whether obsessive beliefs potentiate the influence of disgust propensity on contamination fear. The interaction between disgust propensity and obsessive beliefs was tested in two large non-clinical samples (N = 252 in Study 1; N = 308 in Study 2) using two different self-report measures of contamination fear. Regression analyses supported the hypotheses in both samples. The interaction remained significant when controlling for negative affect. The results are hypothesized to suggest that contamination fear results, at least partly, from obsessive beliefs about the contamination-based appraisals that accompany heightened disgust responding. These results complement previous affective-driven explanations of the role of disgust in contamination fear by suggesting cognitive factors that similarly potentiate disgust’s role in contamination fear. PMID:20877585

Women’s Education, Marital Violence, and Divorce: A Social Exchange Perspective

PubMed Central

Kreager, Derek A.; Felson, Richard B.; Warner, Cody; Wenger, Marin R.

2013-01-01

Drawing on social exchange theories, the authors hypothesized that educated women are more likely than uneducated women to leave violent marriages and suggested that this pattern offsets the negative education – divorce association commonly found in the United States. They tested these hypotheses using 2 waves of young adult data on 914 married women from the National Longitudinal Study of Adolescent Health. The evidence suggests that the negative relationship between women’s education and divorce is weaker when marriages involve abuse than when they do not. The authors observed a similar pattern when they examined the association of women’s proportional earnings and divorce, controlling for education. Supplementary analyses suggested that marital satisfaction explains some of the association among women’s resources, victimization, and divorce but that marital violence continues to be a significant moderator of the education – divorce association. In sum, education appears to benefit women by both maintaining stable marriages and dissolving violent ones. PMID:24357879

Neural Dynamics Underlying Event-Related Potentials

NASA Technical Reports Server (NTRS)

Shah, Ankoor S.; Bressler, Steven L.; Knuth, Kevin H.; Ding, Ming-Zhou; Mehta, Ashesh D.; Ulbert, Istvan; Schroeder, Charles E.

2003-01-01

There are two opposing hypotheses about the brain mechanisms underlying sensory event-related potentials (ERPs). One holds that sensory ERPs are generated by phase resetting of ongoing electroencephalographic (EEG) activity, and the other that they result from signal averaging of stimulus-evoked neural responses. We tested several contrasting predictions of these hypotheses by direct intracortical analysis of neural activity in monkeys. Our findings clearly demonstrate evoked response contributions to the sensory ERP in the monkey, and they suggest the likelihood that a mixed (Evoked/Phase Resetting) model may account for the generation of scalp ERPs in humans.

Inhibitory effects of KN-93, an inhibitor of Ca2+ calmodulin-dependent protein kinase II, on light-regulated root gravitropism in maize

NASA Technical Reports Server (NTRS)

Feldman, L. J.; Hidaka, H.

1993-01-01

Light is essential for root gravitropism in Zea mays L., cultivar Merit. It is hypothesized that calcium mediates this light-regulated response. KN-93, an inhibitor of calcium/calmodulin kinase II (CaMK II), inhibits light-regulated root gravitropism but does not affect light perception. We hypothesize that CaMK II, or a homologue, operates late in the light/gravity signal transduction chain. Here we provide evidence suggesting a possible physiological involvement of CaMK II in root gravitropism in plants.

Phylogenomics resolves a spider backbone phylogeny and rejects a prevailing paradigm for orb web evolution.

PubMed

Bond, Jason E; Garrison, Nicole L; Hamilton, Chris A; Godwin, Rebecca L; Hedin, Marshal; Agnarsson, Ingi

2014-08-04

Spiders represent an ancient predatory lineage known for their extraordinary biomaterials, including venoms and silks. These adaptations make spiders key arthropod predators in most terrestrial ecosystems. Despite ecological, biomedical, and biomaterial importance, relationships among major spider lineages remain unresolved or poorly supported. Current working hypotheses for a spider "backbone" phylogeny are largely based on morphological evidence, as most molecular markers currently employed are generally inadequate for resolving deeper-level relationships. We present here a phylogenomic analysis of spiders including taxa representing all major spider lineages. Our robust phylogenetic hypothesis recovers some fundamental and uncontroversial spider clades, but rejects the prevailing paradigm of a monophyletic Orbiculariae, the most diverse lineage, containing orb-weaving spiders. Based on our results, the orb web either evolved much earlier than previously hypothesized and is ancestral for a majority of spiders or else it has multiple independent origins, as hypothesized by precladistic authors. Cribellate deinopoid orb weavers that use mechanically adhesive silk are more closely related to a diverse clade of mostly webless spiders than to the araneoid orb-weaving spiders that use adhesive droplet silks. The fundamental shift in our understanding of spider phylogeny proposed here has broad implications for interpreting the evolution of spiders, their remarkable biomaterials, and a key extended phenotype--the spider web. Copyright © 2014 Elsevier Ltd. All rights reserved.

Understanding the elevated suicide risk of female soldiers during deployments.

PubMed

Street, A E; Gilman, S E; Rosellini, A J; Stein, M B; Bromet, E J; Cox, K L; Colpe, L J; Fullerton, C S; Gruber, M J; Heeringa, S G; Lewandowski-Romps, L; Little, R J A; Naifeh, J A; Nock, M K; Sampson, N A; Schoenbaum, M; Ursano, R J; Zaslavsky, A M; Kessler, R C

2015-03-01

The Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) has found that the proportional elevation in the US Army enlisted soldier suicide rate during deployment (compared with the never-deployed or previously deployed) is significantly higher among women than men, raising the possibility of gender differences in the adverse psychological effects of deployment. Person-month survival models based on a consolidated administrative database for active duty enlisted Regular Army soldiers in 2004-2009 (n = 975,057) were used to characterize the gender × deployment interaction predicting suicide. Four explanatory hypotheses were explored involving the proportion of females in each soldier's occupation, the proportion of same-gender soldiers in each soldier's unit, whether the soldier reported sexual assault victimization in the previous 12 months, and the soldier's pre-deployment history of treated mental/behavioral disorders. The suicide rate of currently deployed women (14.0/100,000 person-years) was 3.1-3.5 times the rates of other (i.e. never-deployed/previously deployed) women. The suicide rate of currently deployed men (22.6/100,000 person-years) was 0.9-1.2 times the rates of other men. The adjusted (for time trends, sociodemographics, and Army career variables) female:male odds ratio comparing the suicide rates of currently deployed v. other women v. men was 2.8 (95% confidence interval 1.1-6.8), became 2.4 after excluding soldiers with Direct Combat Arms occupations, and remained elevated (in the range 1.9-2.8) after adjusting for the hypothesized explanatory variables. These results are valuable in excluding otherwise plausible hypotheses for the elevated suicide rate of deployed women and point to the importance of expanding future research on the psychological challenges of deployment for women.

Iterative Strategies for Aftershock Classification in Automatic Seismic Processing Pipelines

NASA Astrophysics Data System (ADS)

Gibbons, Steven J.; Kværna, Tormod; Harris, David B.; Dodge, Douglas A.

2016-04-01

Aftershock sequences following very large earthquakes present enormous challenges to near-realtime generation of seismic bulletins. The increase in analyst resources needed to relocate an inflated number of events is compounded by failures of phase association algorithms and a significant deterioration in the quality of underlying fully automatic event bulletins. Current processing pipelines were designed a generation ago and, due to computational limitations of the time, are usually limited to single passes over the raw data. With current processing capability, multiple passes over the data are feasible. Processing the raw data at each station currently generates parametric data streams which are then scanned by a phase association algorithm to form event hypotheses. We consider the scenario where a large earthquake has occurred and propose to define a region of likely aftershock activity in which events are detected and accurately located using a separate specially targeted semi-automatic process. This effort may focus on so-called pattern detectors, but here we demonstrate a more general grid search algorithm which may cover wider source regions without requiring waveform similarity. Given many well-located aftershocks within our source region, we may remove all associated phases from the original detection lists prior to a new iteration of the phase association algorithm. We provide a proof-of-concept example for the 2015 Gorkha sequence, Nepal, recorded on seismic arrays of the International Monitoring System. Even with very conservative conditions for defining event hypotheses within the aftershock source region, we can automatically remove over half of the original detections which could have been generated by Nepal earthquakes and reduce the likelihood of false associations and spurious event hypotheses. Further reductions in the number of detections in the parametric data streams are likely using correlation and subspace detectors and/or empirical matched field processing.

Numerical modeling of a sub Plinian eruption at La Soufrière de Guadeloupe: implications for pyroclastic density currents hazard assessment.

NASA Astrophysics Data System (ADS)

Esposti Ongaro, Tomaso; Neri, Augusto; Komorowski, Jean-Christophe

2013-04-01

We present three-dimensional numerical simulations of a sub-Plinian eruptive scenario at La Soufrière de Guadeloupe, aimed at assessing the capability of pyroclastic density currents to reach the inhabited regions on the volcano slopes, in case of the future resumption of the explosive activity. The selected eruptive scenario is similar to that hypothesized for the 1530 a.D. eruption, but several eruptive conditions have been analyzed to account for different behaviours of the eruptive column and percentages of collapse. Numerical results describe, in 3D and in time, the formation, instability and partial collapse of the eruptive column, and the simultaneous formation of a convective plume and several branched pyroclastic density currents. The proximal volcano morphology, characterized by the presence of ancient caldera rims and the remnants of the old edifice, controls the areal distribution of the collapsed material and the paths of channelized flows along the incised topography. The analysis of the 3D runs suggests that partial collapse scenarios produce steeply stratified pyroclastic density currents, which are strongly controlled by the topography and whose propagation is likely driven by the dynamics of the dense, basal layer. Although vertical grid size still does not allow the resolution of the dynamics of such concentrated flows, preliminary georeferenced maps of pyroclastic density currents' hazardous actions (temperature and dynamic pressure) provide interesting and useful information which can serve as a basis for elaborating a quantitative framework for the assessment of their impact on vulnerable infrastructures, networks, and population.

Role of Active Versus Passive Complementary and Integrative Health Approaches in Pain Management.

PubMed

Cosio, David; Lin, Erica

2018-01-01

A general conclusion about the treatment of chronic, noncancer pain is that the results from traditional, passive modalities are disheartening. Perhaps this may be due to the propensity of patients to seek out passive versus active treatments. In pain management, active treatments should be the primary focus, with passive interventions as an adjunct. The current study tested the hypotheses that Veterans would report a greater significant increase in active versus transitional and active versus passive complementary and integrative health (CIH) utilization after completing a formal pain education program. The current study is a secondary analysis of existing data from an original study. The current study used a quasi-experimental, 1-group, pre-/posttest design. One hundred three Veterans completed a 12-week, "Pain Education School" program at a Midwestern VA Medical Center between November 4, 2011, and October 26, 2012. As part of the introduction and conclusion of the program, all Veterans completed a pre- and posteducation assessment which included an adaptation of the Complementary and Alternative Medicine Questionnaire©, SECTION A: Use of Alternative Health Care Providers measure. Significant differences were found between the pre- and posttest measures of use of active ( P  = .000) ( p <.001), transitional ( P  = .011), and passive ( P  = .007) CIH modalities. The current findings suggest that an educational intervention in conjunction with the availability of treatment options has the potential to increase the use of those treatments. The current pain education program also seems to be aligned with the goal of pain self-management, which is to utilize more active interventions as a primary therapy.

Current and Potential Tree Locations in Tree Line Ecotone of Changbai Mountains, Northeast China: The Controlling Effects of Topography

PubMed Central

Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

2014-01-01

Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountains. To test the hypothesis, we used IKONOS images and WorldView-1 image to identify the tree locations and developed a logistic regression model using topographical variables to identify the dominant controls of the tree locations. The results showed that aspect, wetness, and slope were dominant controls for tree locations on western side of the mountains, whereas altitude, SPI, and aspect were the dominant factors on northern side. The upmost altitude a tree can currently reach was 2140 m asl on the northern side and 2060 m asl on western side. The model predicted results showed that habitats above the current tree line on the both sides were available for trees. Tree recruitments under the current tree line may take advantage of the available habitats at higher elevations based on the current tree location. Our research confirmed the controlling effects of topography on the tree locations in the tree line ecotone of Changbai Mountains and suggested that it was essential to assess the tree response to topography in the research of tree line ecotone. PMID:25170918

Current and potential tree locations in tree line ecotone of Changbai Mountains, Northeast China: the controlling effects of topography.

PubMed

Zong, Shengwei; Wu, Zhengfang; Xu, Jiawei; Li, Ming; Gao, Xiaofeng; He, Hongshi; Du, Haibo; Wang, Lei

2014-01-01

Tree line ecotone in the Changbai Mountains has undergone large changes in the past decades. Tree locations show variations on the four sides of the mountains, especially on the northern and western sides, which has not been fully explained. Previous studies attributed such variations to the variations in temperature. However, in this study, we hypothesized that topographic controls were responsible for causing the variations in the tree locations in tree line ecotone of the Changbai Mountains. To test the hypothesis, we used IKONOS images and WorldView-1 image to identify the tree locations and developed a logistic regression model using topographical variables to identify the dominant controls of the tree locations. The results showed that aspect, wetness, and slope were dominant controls for tree locations on western side of the mountains, whereas altitude, SPI, and aspect were the dominant factors on northern side. The upmost altitude a tree can currently reach was 2140 m asl on the northern side and 2060 m asl on western side. The model predicted results showed that habitats above the current tree line on the both sides were available for trees. Tree recruitments under the current tree line may take advantage of the available habitats at higher elevations based on the current tree location. Our research confirmed the controlling effects of topography on the tree locations in the tree line ecotone of Changbai Mountains and suggested that it was essential to assess the tree response to topography in the research of tree line ecotone.

Age Effects in Postural Control Analyzed via a Principal Component Analysis of Kinematic Data and Interpreted in Relation to Predictions of the Optimal Feedback Control Theory

PubMed Central

Haid, Thomas H.; Doix, Aude-Clémence M.; Nigg, Benno M.; Federolf, Peter A.

2018-01-01

Optimal feedback control theory suggests that control of movement is focused on movement dimensions that are important for the task's success. The current study tested the hypotheses that age effects would emerge in the control of only specific movement components and that these components would be linked to the task relevance. Fifty healthy volunteers, 25 young and 25 older adults, performed a 80s-tandem stance while their postural movements were recorded using a standard motion capture system. The postural movements were decomposed by a principal component analysis into one-dimensional movement components, PMk, whose control was assessed through two variables, Nk and σk, which characterized the tightness and the regularity of the neuro-muscular control, respectively. The older volunteers showed less tight and more irregular control in PM2 (N2: −9.2%, p = 0.007; σ2: +14.3.0%, p = 0.017) but tighter control in PM8 and PM9 (N8: +4.7%, p = 0.020; N9: +2.5%, p = 0.043; σ9: −8.8%, p = 0.025). These results suggest that aging effects alter the postural control system not as a whole, but emerge in specific, task relevant components. The findings of the current study thus support the hypothesis that the minimal intervention principle, as described in the context of optimal feedback control (OFC), may be relevant when assessing aging effects on postural control. PMID:29459826

Women's experiences of continuous fetal monitoring - a mixed-methods systematic review.

PubMed

Crawford, Alexandra; Hayes, Dexter; Johnstone, Edward D; Heazell, Alexander E P

2017-12-01

Antepartum stillbirth is often preceded by detectable signs of fetal compromise, including changes in fetal heart rate and movement. It is hypothesized that continuous fetal monitoring could detect these signs more accurately and objectively than current forms of fetal monitoring and allow for timely intervention. This systematic review aimed to explore available evidence on women's experiences of continuous fetal monitoring to investigate its acceptability before clinical implementation and to inform clinical studies. Systematic searching of four electronic databases (Embase, PsycINFO, MEDLINE and CINAHL), using key terms defined by initial scoping searches, identified a total of 35 studies. Following title and abstract screening by two independent researchers, five studies met the inclusion criteria. Studies were not excluded based on language, methodology or quality assessment. An integrative methodology was used to synthesize qualitative and quantitative data together. Forms of continuous fetal monitoring used included Monica AN24 monitors (n = 4) and phonocardiography (n = 1). Four main themes were identified: practical limitations of the device, negative emotions, positive perceptions, and device implementation. Continuous fetal monitoring was reported to have high levels of participant satisfaction and was preferred by women to intermittent cardiotocography. This review suggests that continuous fetal monitoring is accepted by women. However, it has also highlighted both the paucity and heterogeneity of current studies and suggests that further research should be conducted into women's experiences of continuous fetal monitoring before such devices can be used clinically. © 2017 Nordic Federation of Societies of Obstetrics and Gynecology.

Masculine Traits and Depressive Symptoms in Older and Younger Men and Women

PubMed Central

Price, Elizabeth C.; Gregg, Jeffrey J.; Smith, Merideth D.; Fiske, Amy

2015-01-01

Evidence suggests that men who strongly endorse masculine traits display an atypical presentation of depression, including more externalizing symptoms (e.g., anger or substance use), but fewer typical, internalizing symptoms (e.g., depressed mood or crying). This phenomenon has not been adequately explored in older adults or women. The current study used the externalizing subscale of the Masculine Depression Scale in older and younger men and women to detect atypical symptoms. It was predicted that individuals who more strongly endorsed masculine traits would have higher scores on the measure of externalizing symptoms relative to a measure of typical depressive symptoms Center for Epidemiologic Studies–Depression Scale. It was anticipated that results would differ by age-group but not by gender. Multigroup path analysis was used to test the hypothesis. The hypothesized path model, in which endorsement of masculine traits was associated with lower scores on the Center for Epidemiologic Studies–Depression Scale and with scores on the externalizing, but not internalizing, factor of the Masculine Depression Scale, fit the data well. Results differed significantly by age-group and gender. Masculine individuals reported lower levels of typical depressive symptoms relative to externalizing symptoms, but further research is needed within age- and gender groups. Results are consistent with the gendered responding framework and suggest that current assessment tools, which tend to focus on internalizing symptoms of depression, may not detect depression in individuals who endorse masculine traits. PMID:26634856

The impact of binaural beats on creativity

PubMed Central

Reedijk, Susan A.; Bolders, Anne; Hommel, Bernhard

2013-01-01

Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale—mood State questionnaire (PANAS-S) and an affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs). Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBRs were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods. PMID:24294202

The impact of binaural beats on creativity.

PubMed

Reedijk, Susan A; Bolders, Anne; Hommel, Bernhard

2013-01-01

Human creativity relies on a multitude of cognitive processes, some of which are influenced by the neurotransmitter dopamine. This suggests that creativity could be enhanced by interventions that either modulate the production or transmission of dopamine directly, or affect dopamine-driven processes. In the current study we hypothesized that creativity can be influenced by means of binaural beats, an auditory illusion that is considered a form of cognitive entrainment that operates through stimulating neuronal phase locking. We aimed to investigate whether binaural beats affect creative performance at all, whether they affect divergent thinking, convergent thinking, or both, and whether possible effects may be mediated by the individual striatal dopamine level. Binaural beats were presented at alpha and gamma frequency. Participants completed a divergent and a convergent thinking task to assess two important functions of creativity, and filled out the Positive And Negative Affect Scale-mood State questionnaire (PANAS-S) and an affect grid to measure current mood. Dopamine levels in the striatum were estimated using spontaneous eye blink rates (EBRs). Results showed that binaural beats, regardless of the presented frequency, can affect divergent but not convergent thinking. Individuals with low EBRs mostly benefitted from alpha binaural beat stimulation, while individuals with high EBRs were unaffected or even impaired by both alpha and gamma binaural beats. This suggests that binaural beats, and possibly other forms of cognitive entrainment, are not suited for a one-size-fits-all approach, and that individual cognitive-control systems need to be taken into account when studying cognitive enhancement methods.

The Glutamatergic Aspects of Schizophrenia Molecular Pathophysiology: Role of the Postsynaptic Density, and Implications for Treatment

PubMed Central

Iasevoli, Felice; Tomasetti, Carmine; Buonaguro, Elisabetta F.; de Bartolomeis, Andrea

2014-01-01

Schizophrenia is one of the most debilitating psychiatric diseases with a lifetime prevalence of approximately 1%. Although the specific molecular underpinnings of schizophrenia are still unknown, evidence has long linked its pathophysiology to postsynaptic abnormalities. The postsynaptic density (PSD) is among the molecular structures suggested to be potentially involved in schizophrenia. More specifically, the PSD is an electron-dense thickening of glutamatergic synapses, including ionotropic and metabotropic glutamate receptors, cytoskeletal and scaffolding proteins, and adhesion and signaling molecules. Being implicated in the postsynaptic signaling of multiple neurotransmitter systems, mostly dopamine and glutamate, the PSD constitutes an ideal candidate for studying dopamine-glutamate disturbances in schizophrenia. Recent evidence suggests that some PSD proteins, such as PSD-95, Shank, and Homer are implicated in severe behavioral disorders, including schizophrenia. These findings, further corroborated by genetic and animal studies of schizophrenia, offer new insights for the development of pharmacological strategies able to overcome the limitations in terms of efficacy and side effects of current schizophrenia treatment. Indeed, PSD proteins are now being considered as potential molecular targets against this devastating illness. The current paper reviews the most recent hypotheses on the molecular mechanisms underlying schizophrenia pathophysiology. First, we review glutamatergic dysfunctions in schizophrenia and we provide an update on postsynaptic molecules involvement in schizophrenia pathophysiology by addressing both human and animal studies. Finally, the possibility that PSD proteins may represent potential targets for new molecular interventions in psychosis will be discussed. PMID:24851087

How are lung cancer risk perceptions and cigarette smoking related?-testing an accuracy hypothesis.

PubMed

Chen, Lei-Shih; Kaphingst, Kimberly A; Tseng, Tung-Sung; Zhao, Shixi

2016-10-01

Subjective risk perception is an important theoretical construct in the field of cancer prevention and control. Although the relationship between subjective risk perception and health behaviors has been widely studied in many health contexts, the causalities and associations between the risk perception of developing lung cancer and cigarette smoking have been inconsistently reported among studies. Such inconsistency may be from discrepancies between study designs (cross-sectional versus longitudinal designs) and the three hypotheses (i.e., the behavior motivation hypothesis, the risk reappraisals hypothesis, and the accuracy hypothesis) testing different underlying associations between risk perception and cigarette-smoking behaviors. To clarify this issue, as an initial step, we examined the association between absolute and relative risk perceptions of developing lung cancer and cigarette-smoking behaviors among a large, national representative sample of 1,680 U.S. adults by testing an accuracy hypothesis (i.e., people who smoke accurately perceived a higher risk of developing lung cancer). Data from the U.S. Health Information National Trends Survey (HINTS) were analyzed using logistic regression and multivariate linear regression to examine the associations between risk perception and cigarette-smoking behaviors among 1,680 U.S. adults. Findings from this cross-sectional survey suggest that absolute and relative risk perceptions were positively and significantly correlated with having smoked >100 cigarettes during lifetime and the frequency of cigarette smoking. Only absolute risk perception was significantly associated with the number of cigarettes smoked per day among current smokers. Because both absolute and relative risk perceptions are positively related to most cigarette-smoking behaviors, this study supports the accuracy hypothesis. Moreover, absolute risk perception might be a more sensitive measurement than relative risk perception for perceived lung cancer risk. Longitudinal research is needed in the future to investigate other types of risk perception-risk behavior hypotheses-the behavior motivation and the risk reappraisals hypotheses-among nationally representative samples to further examine the causations between risk perception of obtaining lung cancer and smoking behaviors.

Why do some, but not all, tropical birds migrate? A comparative study of diet breadth and fruit preference

USGS Publications Warehouse

Boyle, W.A.; Conway, C.J.; Bronstein, Judith L.

2011-01-01

Annual migrations of birds profoundly influence terrestrial communities. However, few empirical studies examine why birds migrate, in part due to the difficulty of testing causal hypotheses in long-distance migration systems. Short-distance altitudinal migrations provide relatively tractable systems in which to test explanations for migration. Many past studies explain tropical altitudinal migration as a response to spatial and temporal variation in fruit availability. Yet this hypothesis fails to explain why some coexisting, closely-related frugivorous birds remain resident year-round. We take a mechanistic approach by proposing and evaluating two hypotheses (one based on competitive exclusion and the other based on differences in dietary specialization) to explain why some, but not all, tropical frugivores migrate. We tested predictions of these hypotheses by comparing diets, fruit preferences, and the relationships between diet and preference in closely-related pairs of migrant and resident species. Fecal samples and experimental choice trials revealed that sympatric migrants and residents differed in both their diets and fruit preferences. Migrants consumed a greater diversity of fruits and fewer arthropods than did their resident counterparts. Migrants also tended to have slightly stronger fruit preferences than residents. Most critically, diets of migrants more closely matched their preferences than did the diets of residents. These results suggest that migrants may be competitively superior foragers for fruit compared to residents (rather than vice versa), implying that current competitive interactions are unlikely to explain variation in migratory behavior among coexisting frugivores. We found some support for the dietary specialization hypothesis, propose refinements to the mechanism underlying this hypothesis, and discuss how dietary specialization might ultimately reflect past interspecific competition. We recommend that future studies quantify variation in nutritional content of tropical fruits, and determine whether frugivory is a consequence or a cause of migratory behaviour. ?? 2010 Springer Science+Business Media B.V.

Cnidarian phylogenetic relationships as revealed by mitogenomics

PubMed Central

2013-01-01

Background Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia + Octocorallia) – cnidarians with a reproductive polyp and the absence of a medusa stage – and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) – cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. Results We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia + Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae + Coronatae], Acraspeda [Cubozoa + Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. Conclusions Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa. The expansion of mitogenomic data along with improvements in phylogenetic inference methods and use of additional nuclear markers will further enhance our understanding of the phylogenetic relationships and character evolution within Cnidaria. PMID:23302374

Cnidarian phylogenetic relationships as revealed by mitogenomics.

PubMed

Kayal, Ehsan; Roure, Béatrice; Philippe, Hervé; Collins, Allen G; Lavrov, Dennis V

2013-01-09

Cnidaria (corals, sea anemones, hydroids, jellyfish) is a phylum of relatively simple aquatic animals characterized by the presence of the cnidocyst: a cell containing a giant capsular organelle with an eversible tubule (cnida). Species within Cnidaria have life cycles that involve one or both of the two distinct body forms, a typically benthic polyp, which may or may not be colonial, and a typically pelagic mostly solitary medusa. The currently accepted taxonomic scheme subdivides Cnidaria into two main assemblages: Anthozoa (Hexacorallia + Octocorallia) - cnidarians with a reproductive polyp and the absence of a medusa stage - and Medusozoa (Cubozoa, Hydrozoa, Scyphozoa, Staurozoa) - cnidarians that usually possess a reproductive medusa stage. Hypothesized relationships among these taxa greatly impact interpretations of cnidarian character evolution. We expanded the sampling of cnidarian mitochondrial genomes, particularly from Medusozoa, to reevaluate phylogenetic relationships within Cnidaria. Our phylogenetic analyses based on a mitochogenomic dataset support many prior hypotheses, including monophyly of Hexacorallia, Octocorallia, Medusozoa, Cubozoa, Staurozoa, Hydrozoa, Carybdeida, Chirodropida, and Hydroidolina, but reject the monophyly of Anthozoa, indicating that the Octocorallia + Medusozoa relationship is not the result of sampling bias, as proposed earlier. Further, our analyses contradict Scyphozoa [Discomedusae + Coronatae], Acraspeda [Cubozoa + Scyphozoa], as well as the hypothesis that Staurozoa is the sister group to all the other medusozoans. Cnidarian mitochondrial genomic data contain phylogenetic signal informative for understanding the evolutionary history of this phylum. Mitogenome-based phylogenies, which reject the monophyly of Anthozoa, provide further evidence for the polyp-first hypothesis. By rejecting the traditional Acraspeda and Scyphozoa hypotheses, these analyses suggest that the shared morphological characters in these groups are plesiomorphies, originated in the branch leading to Medusozoa. The expansion of mitogenomic data along with improvements in phylogenetic inference methods and use of additional nuclear markers will further enhance our understanding of the phylogenetic relationships and character evolution within Cnidaria.

Quantal amplitude at the cone ribbon synapse can be adjusted by changes in cytosolic glutamate

PubMed Central

Bartoletti, Theodore M.

2011-01-01

Purpose Vision is encoded at photoreceptor synapses by the number of released vesicles and size of the post-synaptic response. We hypothesized that elevating cytosolic glutamate could enhance quantal size by increasing glutamate in vesicles. Methods We introduced glutamate (10–40 mM) into cone terminals through a patch pipette and recorded excitatory post-synaptic currents (EPSCs) from horizontal or OFF bipolar cells in the Ambystoma tigrinum retinal slice preparation. Results Elevating cytosolic glutamate in cone terminals enhanced EPSCs as well as quantal miniature EPSCs (mEPSCs). Enhancement was prevented by inhibiting vesicular glutamate transport with 1S,3R-1-aminocyclopentane-1,3-dicarboxylate in the patch pipette. A low affinity glutamate receptor antagonist, γD-glutamylglycine (1 mM), less effectively inhibited EPSCs evoked from cones loaded with glutamate than control cones indicating that release from cones with supplemental glutamate produced higher glutamate levels in the synaptic cleft. Raising presynaptic glutamate did not alter exocytotic capacitance responses and exocytosis was observed after inhibiting glutamate loading with the vesicular ATPase inhibitor, concanamycin A, suggesting that release capability is not restricted by low vesicular glutamate levels. Variance-mean analysis of currents evoked by flash photolysis of caged glutamate indicated that horizontal cell AMPA receptors have a single channel conductance of 10.1 pS suggesting that ~8.7 GluRs contribute to each mEPSC. Conclusions Quantal amplitude at the cone ribbon synapse is capable of adjustment by changes in cytosolic glutamate levels. The small number of channels contributing to each mEPSC suggests that stochastic variability in channel opening could be an important source of quantal variability. PMID:21541265

Efficacy-mediated effects of spirituality and physical activity on quality of life: A path analysis

PubMed Central

2012-01-01

Background Physical activity has been established as an important determinant of quality of life, particularly among older adults. Previous research has suggested that physical activity’s influence on quality of life perceptions is mediated by changes in self-efficacy and health status. In the same vein, spirituality may be a salient quality of life determinant for many individuals. Methods In the current study, we used path analysis to test a model in which physical activity, spirituality, and social support were hypothesized to influence global quality of life in paths mediated by self-efficacy and health status. Cross-sectional data were collected from a sample of 215 adults (male, n = 51; female, n = 164) over the age of 50 (M age = 66.55 years). Results The analysis resulted in a model that provided acceptable fit to the data (χ2 = 33.10, df = 16, p < .01; RMSEA = .07; SRMR = .05; CFI = .94). Conclusions These results support previous findings of an efficacy-mediated relationship between physical activity and quality of life, with the exception that self-efficacy in the current study was moderately associated with physical health status (.38) but not mental health status. Our results further suggest that spirituality may influence health and well-being via a similar, efficacy-mediated path, with strongest effects on mental health status. These results suggest that those who are more spiritual and physically active report greater quality of life, and the effects of these factors on quality of life may be partially mediated by perceptions of self-efficacy. PMID:22642832

Exosomes confer pro-survival signals to alter the phenotype of prostate cells in their surrounding environment

PubMed Central

Hosseini-Beheshti, Elham; Choi, Wendy; Weiswald, Louis-Bastien; Kharmate, Geetanjali; Ghaffari, Mazyar; Roshan-Moniri, Mani; Hassona, Mohamed D.; Chan, Leslie; Chin, Mei Yieng; Tai, Isabella T.; Rennie, Paul S.; Fazli, Ladan; Guns, Emma S. Tomlinson

2016-01-01

Prostate cancer (PCa) is the most frequently diagnosed cancer in men. Current research on tumour-related extracellular vesicles (EVs) suggests that exosomes play a significant role in paracrine signaling pathways, thus potentially influencing cancer progression via multiple mechanisms. In fact, during the last decade numerous studies have revealed the role of EVs in the progression of various pathological conditions including cancer. Moreover, differences in the proteomic, lipidomic, and cholesterol content of exosomes derived from PCa cell lines versus benign prostate cell lines confirm that exosomes could be excellent biomarker candidates. As such, as part of an extensive proteomic analysis using LCMS we previously described a potential role of exosomes as biomarkers for PCa. Current evidence suggests that uptake of EV's into the local tumour microenvironment encouraging us to further examine the role of these vesicles in distinct mechanisms involved in the progression of PCa and castration resistant PCa. For the purpose of this study, we hypothesized that exosomes play a pivotal role in cell-cell communication in the local tumour microenvironment, conferring activation of numerous survival mechanisms during PCa progression and development of therapeutic resistance. Our in vitro results demonstrate that PCa derived exosomes significantly reduce apoptosis, increase cancer cell proliferation and induce cell migration in LNCaP and RWPE-1 cells. In conjunction with our in vitro findings, we have also demonstrated that exosomes increased tumor volume and serum PSA levels in vivo when xenograft bearing mice were administered DU145 cell derived exosomes intravenously. This research suggests that, regardless of androgen receptor phenotype, exosomes derived from PCa cells significantly enhance multiple mechanisms that contribute to PCa progression. PMID:26840259

Symptom changes in five dimensions of the Positive and Negative Syndrome Scale in refractory psychosis.

PubMed

Woodward, Todd S; Jung, Kwanghee; Smith, Geoffrey N; Hwang, Heungsun; Barr, Alasdair M; Procyshyn, Ric M; Flynn, Sean W; van der Gaag, Mark; Honer, William G

2014-12-01

Refractory psychosis units currently have little information regarding which symptoms profiles should be expected to respond to treatment. In the current study, we provide this information using structural equation modeling of Positive and Negative Syndrome Scale (PANSS) ratings at admission and discharge on a sample of 610 patients admitted to a treatment refractory psychosis program at a Canadian tertiary care unit between 1990 and 2011. The hypothesized five-dimensional structure of the PANSS fit the data well at both admission and discharge, and the latent variable scores are reported as a function of symptom dimension and diagnostic category. The results suggest that, overall, positive symptoms (POS) responded to treatment better than all other symptoms dimensions, but for the schizoaffective and bipolar groups, greater response on POS was observed relative to the schizophrenia and major depression groups. The major depression group showed the most improvement on negative symptoms and emotional distress, and the bipolar group showed the most improvement on disorganization. Schizophrenia was distinct from schizoaffective disorder in showing reduced treatment response on all symptom dimensions. These results can assist refractory psychosis units by providing information on how PANSS symptom dimensions respond to treatment and how this depends on diagnostic category.

Temperature mediated moose survival in Northeastern Minnesota

USGS Publications Warehouse

Lenarz, M.S.; Nelson, M.E.; Schrage, M.W.; Edwards, A.J.

2009-01-01

The earth is in the midst of a pronounced warming trend and temperatures in Minnesota, USA, as elsewhere, are projected to increase. Northern Minnesota represents the southern edge to the circumpolar distribution of moose (Alces alces), a species intolerant of heat. Moose increase their metabolic rate to regulate their core body temperature as temperatures rise. We hypothesized that moose survival rates would be a function of the frequency and magnitude that ambient temperatures exceeded the upper critical temperature of moose. We compared annual and seasonal moose survival in northeastern Minnesota between 2002 and 2008 with a temperature metric. We found that models based on January temperatures above the critical threshold were inversely correlated with subsequent survival and explained >78 of variability in spring, fall, and annual survival. Models based on late-spring temperatures also explained a high proportion of survival during the subsequent fall. A model based on warm-season temperatures was important in explaining survival during the subsequent winter. Our analyses suggest that temperatures may have a cumulative influence on survival. We expect that continuation or acceleration of current climate trends will result in decreased survival, a decrease in moose density, and ultimately, a retreat of moose northward from their current distribution.

The John Charnley Award Paper. The role of joint fluid in the tribology of total joint arthroplasty.

PubMed

Mazzucco, Daniel; Spector, Myron

2004-12-01

The effect of joint fluid on the tribology (ie, lubrication, friction, and wear) of total hip arthroplasty has not yet been investigated adequately. In the current study, a friction assay was used to assess four hypotheses relating to the effect of human joint fluid and its principal components on the articulation of metal-on-polyethylene. First, joint fluid was found to produce a widely varying amount of friction between cobalt-chromium and polyethylene; this range exceeded the range produced when the articulation was lubricated by water or bovine serum. Second, it was shown that hyaluronic acid, phospholipid, albumin, and gamma-globulin were not acting as boundary lubricants, but that one or more other proteins (as yet unidentified) were responsible for reducing friction in this couple. Third, lower friction was found when oxidized zirconium alloy replaced cobalt-chromium as a bearing surface on polyethylene. Finally, a pilot study suggested that lubricin, which contributes to cartilage-on-cartilage lubrication, is not a protein responsible for the tribological variabiation found among joint fluid samples. The current study showed that joint fluid is a patient factor that influences the tribology of metal-on-polyethylene arthroplasty.

Does Reconsolidation Occur in Humans?

PubMed Central

Schiller, Daniela; Phelps, Elizabeth A.

2011-01-01

Evidence for reconsolidation in non-human animals has accumulated rapidly in the last decade, providing compelling` demonstration for this phenomenon across species and memory paradigms. In vast contrast, scant evidence exists for human reconsolidation to date. A major reason for this discrepancy is the invasive nature of current techniques used to investigate reconsolidation, which are difficult to apply in humans. Pharmacological blockade of reconsolidation, for example, has been typically used in animals as a proof of concept. However, most compounds used in these studies are toxic for humans, and those compounds that are safe target related, but not direct mechanisms of reconsolidation. Thus, although human reconsolidation has been hypothesized, there is limited evidence it actually exists. The best evidence for human reconsolidation emerges from non-invasive techniques that “update” memory during reconsolidation rather than block it, a technique only rarely used in animal research. Here we discuss the current state of human reconsolidation and the challenges ahead. We review findings on reconsolidation of emotional associative, episodic, and procedural memories, using invasive and non-invasive techniques. We discuss the possible interpretation of these results, attempt to reconcile some inconsistencies, and suggest a conceptual framework for future research. PMID:21629821

Delay of gratification by orangutans (Pongo pygmaeus) in the accumulation task.

PubMed

Parrish, Audrey E; Perdue, Bonnie M; Stromberg, Erin E; Bania, Amanda E; Evans, Theodore A; Beran, Michael J

2014-05-01

There is considerable evidence indicating that chimpanzees can delay gratification for extended time intervals, particularly in the accumulation task in which food items accumulate within a participant's reach until the participant begins to consume them. However, there is limited evidence that other ape species might also exhibit this capacity, despite there being a number of similar studies indicating that nonape species (e.g., monkeys and birds) can delay gratification, but not for nearly as long as chimpanzees. To help define the taxonomic distribution of delay of gratification behavior in the order Primates, we tested 6 orangutans in the current experiments and compared their performance with comparable data from a previous study with capuchin monkeys. We varied delay length and visibility of the items that were still available for accumulation to determine the impact of these factors on performance. Species differences on the accumulation task emerged when comparing the current data to data from a previous study. Orangutans outperformed capuchin monkeys, suggesting that ape species may generally show better delay of gratification and delay maintenance abilities than monkeys. However, more studies are necessary to rule out alternative hypotheses on the distribution of delay maintenance abilities across primate species. ©2014 APA, all rights reserved.

Neural mechanisms of the link between giving social support and health.

PubMed

Inagaki, Tristen K

2018-05-11

Giving social support to others has emerged as an additional route by which social ties influence health. Thus, giving support to others not only influences the health of the individual receiving support, but also the health of the individual giving the support. However, the neural mechanisms by which giving support leads to health are only beginning to be explored. In hopes of consolidating and guiding future research on giving support and health, the current review considers why, how, and when giving support is health promoting. Special emphasis is placed on neural regions known to contribute to parental care in animals that both reinforce giving support behavior (ventral striatum and septal area) and reduce stress-related responding (e.g., amygdala) to facilitate care. Hypothesized links between neural regions involved in giving support and peripheral physiology (sympathetic nervous system, hypothalamic-pituitary-adrenal axis, and related inflammatory responding) are considered as well as the conditions under which giving support should be most beneficial for health. Finally, the implications of the current perspective for understanding how social relationships, more broadly, contribute to health and suggestions for future directions are offered. © 2018 New York Academy of Sciences.

Interactome Mapping Guided by Tissue-Specific Phosphorylation in Age-Related Macular Degeneration

PubMed Central

Sripathi, Srinivas R.; He, Weilue; Prigge, Cameron L.; Sylvester, O’Donnell; Um, Ji-Yeon; Powell, Folami L.; Neksumi, Musa; Bernstein, Paul S.; Choo, Dong-Won; Bartoli, Manuela; Gutsaeva, Diana R.; Jahng, Wan Jin

2017-01-01

The current study aims to determine the molecular mechanisms of age-related macular degeneration (AMD) using the phosphorylation network. Specifically, we examined novel biomarkers for oxidative stress by protein interaction mapping using in vitro and in vivo models that mimic the complex and progressive characteristics of AMD. We hypothesized that the early apoptotic reactions could be initiated by protein phosphorylation in region-dependent (peripheral retina vs. macular) and tissue-dependent (retinal pigment epithelium vs. retina) manner under chronic oxidative stress. The analysis of protein interactome and oxidative biomarkers showed the presence of tissue- and region-specific post-translational mechanisms that contribute to AMD progression and suggested new therapeutic targets that include ubiquitin, erythropoietin, vitronectin, MMP2, crystalline, nitric oxide, and prohibitin. Phosphorylation of specific target proteins in RPE cells is a central regulatory mechanism as a survival tool under chronic oxidative imbalance. The current interactome map demonstrates a positive correlation between oxidative stress-mediated phosphorylation and AMD progression and provides a basis for understanding oxidative stress-induced cytoskeletal changes and the mechanism of aggregate formation induced by protein phosphorylation. This information could provide an effective therapeutic approach to treat age-related neurodegeneration. PMID:28580316

Interactome Mapping Guided by Tissue-Specific Phosphorylation in Age-Related Macular Degeneration.

PubMed

Sripathi, Srinivas R; He, Weilue; Prigge, Cameron L; Sylvester, O'Donnell; Um, Ji-Yeon; Powell, Folami L; Neksumi, Musa; Bernstein, Paul S; Choo, Dong-Won; Bartoli, Manuela; Gutsaeva, Diana R; Jahng, Wan Jin

2017-02-01

The current study aims to determine the molecular mechanisms of age-related macular degeneration (AMD) using the phosphorylation network. Specifically, we examined novel biomarkers for oxidative stress by protein interaction mapping using in vitro and in vivo models that mimic the complex and progressive characteristics of AMD. We hypothesized that the early apoptotic reactions could be initiated by protein phosphorylation in region-dependent (peripheral retina vs. macular) and tissue-dependent (retinal pigment epithelium vs. retina) manner under chronic oxidative stress. The analysis of protein interactome and oxidative biomarkers showed the presence of tissue- and region-specific post-translational mechanisms that contribute to AMD progression and suggested new therapeutic targets that include ubiquitin, erythropoietin, vitronectin, MMP2, crystalline, nitric oxide, and prohibitin. Phosphorylation of specific target proteins in RPE cells is a central regulatory mechanism as a survival tool under chronic oxidative imbalance. The current interactome map demonstrates a positive correlation between oxidative stress-mediated phosphorylation and AMD progression and provides a basis for understanding oxidative stress-induced cytoskeletal changes and the mechanism of aggregate formation induced by protein phosphorylation. This information could provide an effective therapeutic approach to treat age-related neurodegeneration.

Real and virtual worlds alike: Adolescents' psychopathology is reflected in their videogame virtual behaviors.

PubMed

Segev, Aviv; Gabay-Weschler, Hila; Naar, Yossi; Maoz, Hagai; Bloch, Yuval

2017-01-01

Current research refers to videogames as a constant variable. However, games today are designed to be highly interactive and versatile: two players may be using the same videogame, but as a result of different using patterns, the game will not necessarily encompass the same content and gameplay. The current study examined the possible relationship between psychopathology and in-game playing patterns. We hypothesized that adolescents would play videogames differently, in a manner that would reflect their particular psychopathologies. We examined 47 male adolescents from three diagnostic groups: those suffering from externalizing psychopathologies, internalizing psychopathologies and controls. We performed a high-resolution examination of their gameplay, using in-game quantitative statistics mechanisms of two fundamentally different games, a structured racing game and an unstructured adventure game. While there was no difference in the groups' using patterns of the structured game, there was a high variability between the groups' using patterns when they were using a non-structured game. These findings suggest that virtual behavior in unstructured games is reflective of adolescent-players psychopathology, and might shed light on an unexplored facet of videogames research. Possible implications are discussed.

Real and virtual worlds alike: Adolescents' psychopathology is reflected in their videogame virtual behaviors

PubMed Central

Gabay-Weschler, Hila; Naar, Yossi; Maoz, Hagai; Bloch, Yuval

2017-01-01

Current research refers to videogames as a constant variable. However, games today are designed to be highly interactive and versatile: two players may be using the same videogame, but as a result of different using patterns, the game will not necessarily encompass the same content and gameplay. The current study examined the possible relationship between psychopathology and in-game playing patterns. We hypothesized that adolescents would play videogames differently, in a manner that would reflect their particular psychopathologies. We examined 47 male adolescents from three diagnostic groups: those suffering from externalizing psychopathologies, internalizing psychopathologies and controls. We performed a high-resolution examination of their gameplay, using in-game quantitative statistics mechanisms of two fundamentally different games, a structured racing game and an unstructured adventure game. While there was no difference in the groups' using patterns of the structured game, there was a high variability between the groups' using patterns when they were using a non-structured game. These findings suggest that virtual behavior in unstructured games is reflective of adolescent-players psychopathology, and might shed light on an unexplored facet of videogames research. Possible implications are discussed. PMID:28708879

Intra-tidal variability of the vertical current structure in the western Dutch Wadden Sea

NASA Astrophysics Data System (ADS)

de Vries, Jurre; Ridderinkhof, Herman; van Aken, Hendrik

2014-05-01

Long-term velocity measurements are presented which were collected during three different seasons at one single location in an estuarine basin of the western Dutch Wadden Sea. These data are used to investigate the processes that determine the variability of the vertical current structure in the western Dutch Wadden Sea, in combination with simplified model runs using the one-dimensional water column model GETM (http://www.getm.eu/). Jay and Musiak [1996] were the first to suggest that intra-tidal variations in the vertical current might be important in determining the residual circulation patterns. More research [e.g. Stacey et al., 2001; Burchard and Hetland, 2010] has supported this hypothesis. Recently, lateral processes have been shown to influence the vertical current structure of alongstream velocity and hence the residual circulation [e.g. Lerczak and Geyer, 2004; Burchard and Schuttelaars, 2012]. Therefore to better understand the tidal dynamics in the western Dutch Wadden Sea, it is crucial to understand the processes that determine the vertical current structure. The two main findings of this study are that the complex bathymetry at the study site seems to produce an intra-tidal asymmetry in near-bed velocities and secondly that cross-stream processes strongly modify the current structure during late flood. Near-bed velocity and the bed roughness are greater during ebb than during flood. The GETM simulations suggest that vertical mixing during ebb is sufficient to destroy vertical stratification generated by classical tidal straining. The cross-stream current during late flood generate vertical stratification and drive an early reversal of the flood current near the surface. Therefore, it is hypothesized that this processes might increase the residual estuarine circulation at the study site. References - Burchard, H., Hetland, R.D. (2010), Quantifying the contributions of tidal straining and gravitational circulation to residual circulation in periodically stratified tidal estuaries, Journal of Physical Oceanography, 40(6), 1243-1262 - Burchard, H., Schuttelaars, H.M. (2012), Analysis of tidal straining as driver for estuarine circulation in well-mixed estuaries, Journal of Physical Oceanography, 42(2), 261-271 - Jay, D.A., Musiak, J.D. (1996), Internal tidal asymmetry in channel flows' origins and consequences, Coastal and Estuarine Studies, 50, 211-249 - Stacey, M.T., Burau J.R., Monismith, S.G. (2001), Creation of residual flows in a partially stratified estuary, Journal of Physical Oceanography, 34, 1410-1428

Phenoscape: Identifying Candidate Genes for Evolutionary Phenotypes

PubMed Central

Edmunds, Richard C.; Su, Baofeng; Balhoff, James P.; Eames, B. Frank; Dahdul, Wasila M.; Lapp, Hilmar; Lundberg, John G.; Vision, Todd J.; Dunham, Rex A.; Mabee, Paula M.; Westerfield, Monte

2016-01-01

Phenotypes resulting from mutations in genetic model organisms can help reveal candidate genes for evolutionarily important phenotypic changes in related taxa. Although testing candidate gene hypotheses experimentally in nonmodel organisms is typically difficult, ontology-driven information systems can help generate testable hypotheses about developmental processes in experimentally tractable organisms. Here, we tested candidate gene hypotheses suggested by expert use of the Phenoscape Knowledgebase, specifically looking for genes that are candidates responsible for evolutionarily interesting phenotypes in the ostariophysan fishes that bear resemblance to mutant phenotypes in zebrafish. For this, we searched ZFIN for genetic perturbations that result in either loss of basihyal element or loss of scales phenotypes, because these are the ancestral phenotypes observed in catfishes (Siluriformes). We tested the identified candidate genes by examining their endogenous expression patterns in the channel catfish, Ictalurus punctatus. The experimental results were consistent with the hypotheses that these features evolved through disruption in developmental pathways at, or upstream of, brpf1 and eda/edar for the ancestral losses of basihyal element and scales, respectively. These results demonstrate that ontological annotations of the phenotypic effects of genetic alterations in model organisms, when aggregated within a knowledgebase, can be used effectively to generate testable, and useful, hypotheses about evolutionary changes in morphology. PMID:26500251

Bovid mortality profiles in paleoecological context falsify hypotheses of endurance running-hunting and passive scavenging by early Pleistocene hominins

NASA Astrophysics Data System (ADS)

Bunn, Henry T.; Pickering, Travis Rayne

2010-11-01

The world's first archaeological traces from 2.6 million years ago (Ma) at Gona, in Ethiopia, include sharp-edged cutting tools and cut-marked animal bones, which indicate consumption of skeletal muscle by early hominin butchers. From that point, evidence of hominin meat-eating becomes increasingly more common throughout the Pleistocene archaeological record. Thus, the substantive debate about hominin meat-eating now centers on mode(s) of carcass resource acquisition. Two prominent hypotheses suggest, alternatively, (1) that early Homo hunted ungulate prey by running them to physiological failure and then dispatching them, or (2) that early Homo was relegated to passively scavenging carcass residues abandoned by carnivore predators. Various paleontologically testable predictions can be formulated for both hypotheses. Here we test four predictions concerning age-frequency distributions for bovids that contributed carcass remains to the 1.8 Ma. old FLK 22 Zinjanthropus (FLK Zinj, Olduvai Gorge, Tanzania) fauna, which zooarchaeological and taphonomic data indicate was formed predominantly by early Homo. In all but one case, the bovid mortality data from FLK Zinj violate test predictions of the endurance running-hunting and passive scavenging hypotheses. When combined with other taphonomic data, these results falsify both hypotheses, and lead to the hypothesis that early Homo operated successfully as an ambush predator.

Healing and/or breaking? The mental health implications of repeated economic insecurity.

PubMed

Watson, Barry; Osberg, Lars

2017-09-01

Current literature confirms the negative consequences of contemporaneous economic insecurity for mental health, but ignores possible implications of repeated insecurity. This paper asks how much a person's history of economic insecurity matters for psychological distress by contrasting the implications of two models. Consistent with the health capital literature, the Healing model suggests psychological distress is a stock variable affected by shocks from life events, with past events having less impact than more recent shocks. Alternatively, the Breaking Point model considers that high levels of distress represent a distinct shift in life state, which occurs if the accumulation of past life stresses exceeds some critical value. Using five cycles of Canadian National Population Health Survey data (2000-2009), we model the impact of past economic insecurity shocks on current psychological distress in a way that can distinguish between these hypotheses. In our sample of 1775 males and 1883 females aged 25 to 64, we find a robust healing effect for one-time economic insecurity shocks. For males, only a recent one-time occurrence of economic insecurity is predictive of higher current psychological distress (0.19 standard deviations). Moreover, working age adults tend to recover from past accumulated experiences of economic insecurity if they were recently economically secure. However, consistent with the Breaking Point hypothesis, males experiencing three or four cycles of recent insecurity are estimated to have a level of current psychological distress that is 0.26-0.29 standard deviations higher than those who were employed and job secure throughout the same time period. We also find, consistent with other literature, distinct gender differences - for working age females, all economic insecurity variables are statistically insignificant at conventional levels. Our results suggest that although Canadians are resilient to one-time insecurity shocks, males most vulnerable to repeated bouts suffer from elevated levels of psychological distress. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Social Context of Infant Intention Understanding

ERIC Educational Resources Information Center

Dunphy-Lelii, Sarah; LaBounty, Jennifer; Lane, Jonathan D.; Wellman, Henry M.

2014-01-01

Traditional looking-time paradigms are often used to assess infants' attention to sociocognitive phenomena, but the link between these laboratory scenarios and real-world interactions is unclear. The current study investigated hypothesized relations between traditional social-cognitive looking-time paradigms and their real-world counterparts…

Hope as a Predictor of Interpersonal Suicide Risk

ERIC Educational Resources Information Center

Davidson, Collin L.; Wingate, LaRicka R.; Rasmussen, Kathy A.; Slish, Meredith L.

2009-01-01

The current study hypothesized that (1) hope would negatively predict burdensomeness, thwarted belongingness, and acquired capability to enact lethal injury; (2) hope would negatively predict suicidal ideation; and (3) the interpersonal suicide risk factors would predict suicidal ideation. Results indicated that hope negatively predicted…

Magnetic and electric fields induce directional response in Steinernema carpocapsae

USDA-ARS?s Scientific Manuscript database

Entomopathogenic nematode species respond directionally to various cues including electrical stimuli. For example, in prior research Steinernema carpocapsae was shown to be attracted to an electrical current that was applied to an agar dish. Thus, we hypothesized that these nematodes may use elect...

Assaults on Inmates and Staff by Perpetrators of Intimate Partner Homicide: An Examination of Competing Hypotheses.

PubMed

Sorensen, Jonathan R; Vigen, Mark P; Woods, S O; Williams, Bradley D

2015-11-01

The current study presents the results of an analysis of serious and assaultive prison rule violating behavior among male perpetrators of intimate partner homicide (IPH). Data on prison rule violations were collected from a sample of 189 inmates convicted of IPH in a large, southern prison system. The study focused on the degree of continuity in violent behavior among IPH offenders from the community to the prison setting. The current study tested hypotheses derived from both the feminist perspective (FP) and the general violence perspective (GVP). As a group, IPH offenders were better behaved in prison than other incarcerated homicide offenders, thereby offering some support for the FP. However, the lower level of assaultive behavior among the group was not universal. Characteristics associated with continued violent offending in the prison environment were the same as those found in previous studies of incarcerated homicide offenders, thereby lending greater support to the GVP. © The Author(s) 2014.

The Interpersonal Theory of Suicide

PubMed Central

Van Orden, Kimberly A.; Witte, Tracy K.; Cukrowicz, Kelly C.; Braithwaite, Scott; Selby, Edward A.; Joiner, Thomas E.

2011-01-01

Suicidal behavior is a major problem worldwide and at the same time has received relatively little empirical attention. This relative lack of empirical attention may be due in part to a relative absence of theory development regarding suicidal behavior. The current paper presents the Interpersonal Theory of Suicidal Behavior. We propose that the most dangerous form of suicidal desire is caused by the simultaneous presence of two interpersonal constructs—thwarted belongingness and perceived burdensomeness (and hopelessness about these states)—and further, that the capability to engage in suicidal behavior is separate from the desire to engage in suicidal behavior. According to the theory, the capability for suicidal behavior emerges, via habituation and opponent processes, in response to repeated exposure to physically painful and/or fear-inducing experiences. In the current paper, the theory’s hypotheses are more precisely delineated than in previous presentations (Joiner, 2005), with the aim of inviting scientific inquiry and potential falsification of the theory’s hypotheses. PMID:20438238

Elaborating on theory with middle managers' experience implementing healthcare innovations in practice.

PubMed

Birken, Sarah A; DiMartino, Lisa D; Kirk, Meredith A; Lee, Shoou-Yih D; McClelland, Mark; Albert, Nancy M

2016-01-04

The theory of middle managers' role in implementing healthcare innovations hypothesized that middle managers influence implementation effectiveness by fulfilling the following four roles: diffusing information, synthesizing information, mediating between strategy and day-to-day activities, and selling innovation implementation. The theory also suggested several activities in which middle managers might engage to fulfill the four roles. The extent to which the theory aligns with middle managers' experience in practice is unclear. We surveyed middle managers (n = 63) who attended a nursing innovation summit to (1) assess alignment between the theory and middle managers' experience in practice and (2) elaborate on the theory with examples from middle managers' experience overseeing innovation implementation in practice. Middle managers rated all of the theory's hypothesized four roles as "extremely important" but ranked diffusing and synthesizing information as the most important and selling innovation implementation as the least important. They reported engaging in several activities that were consistent with the theory's hypothesized roles and activities such as diffusing information via meetings and training. They also reported engaging in activities not described in the theory such as appraising employee performance. Middle managers' experience aligned well with the theory and expanded definitions of the roles and activities that it hypothesized. Future studies should assess the relationship between hypothesized roles and the effectiveness with which innovations are implemented in practice. If evidence supports the theory, the theory should be leveraged to promote the fulfillment of hypothesized roles among middle managers, doing so may promote innovation implementation.

Data mining through simulation.

PubMed

Lytton, William W; Stewart, Mark

2007-01-01

Data integration is particularly difficult in neuroscience; we must organize vast amounts of data around only a few fragmentary functional hypotheses. It has often been noted that computer simulation, by providing explicit hypotheses for a particular system and bridging across different levels of organization, can provide an organizational focus, which can be leveraged to form substantive hypotheses. Simulations lend meaning to data and can be updated and adapted as further data come in. The use of simulation in this context suggests the need for simulator adjuncts to manage and evaluate data. We have developed a neural query system (NQS) within the NEURON simulator, providing a relational database system, a query function, and basic data-mining tools. NQS is used within the simulation context to manage, verify, and evaluate model parameterizations. More importantly, it is used for data mining of simulation data and comparison with neurophysiology.

The marketing implications of affective product design.

PubMed

Seva, Rosemary R; Duh, Henry Been-Lirn; Helander, Martin G

2007-11-01

Emotions are compelling human experiences and product designers can take advantage of this by conceptualizing emotion-engendering products that sell well in the market. This study hypothesized that product attributes influence users' emotions and that the relationship is moderated by the adherence of these product attributes to purchase criteria. It was further hypothesized that the emotional experience of the user influences purchase intention. A laboratory study was conducted to validate the hypotheses using mobile phones as test products. Sixty-two participants were asked to assess eight phones from a display of 10 phones and indicate their emotional experiences after assessment. Results suggest that some product attributes can cause intense emotional experience. The attributes relate to the phone's dimensions and the relationship between these dimensions. The study validated the notion of integrating affect in designing products that convey users' personalities.

Mismatch between aspects of hearing impairment and hearing disability/handicap in adult/elderly Cantonese speakers: some hypotheses concerning cultural and linguistic influences.

PubMed

Doyle, J; Wong, L L

1996-12-01

This paper addresses the observation that some Cantonese-speaking adults do not perceive a hearing problem even when hearing screening identifies hearing loss. A sample of 49 Cantonese speakers was surveyed about their self-perceptions of hearing prior to a 25 dB HTL pure-tone screening test. All 49 persons failed the screening test, yet 34 (69.4%) reported that they had no problems hearing during conversations. Persons who admitted hearing difficulties tended to have mean hearing levels in excess of 45 dB HTL. A number of hypotheses concerning cultural and linguistic influences are proposed as explanations for the apparent lack of significance of auditory sensitivity loss for some Cantonese speakers. Ways in which these hypotheses might be tested are suggested.

Thinking Evolutionarily About Obesity

PubMed Central

Genné-Bacon, Elizabeth A.

2014-01-01

Obesity, diabetes, and metabolic syndrome are growing worldwide health concerns, yet their causes are not fully understood. Research into the etiology of the obesity epidemic is highly influenced by our understanding of the evolutionary roots of metabolic control. For half a century, the thrifty gene hypothesis, which argues that obesity is an evolutionary adaptation for surviving periods of famine, has dominated the thinking on this topic. Obesity researchers are often not aware that there is, in fact, limited evidence to support the thrifty gene hypothesis and that alternative hypotheses have been suggested. This review presents evidence for and against the thrifty gene hypothesis and introduces readers to additional hypotheses for the evolutionary origins of the obesity epidemic. Because these alternate hypotheses imply significantly different strategies for research and clinical management of obesity, their consideration is critical to halting the spread of this epidemic. PMID:24910556

A Guard Dog Perspective on the Role of Media.

ERIC Educational Resources Information Center

Donohue, George A.; And Others

1995-01-01

Offers a "guard dog" metaphor for the functioning of the mass media, suggesting that media perform as a sentry for groups having sufficient power and influence to create and control their own security systems. Delineates this perspective from others, and suggests several hypotheses that may be derived for testing the utility of the guard dog…

The Composition of the TV Picture: Suggested Hypotheses to Test the Forces That Operate within the Television Screen.

ERIC Educational Resources Information Center

Metallinos, Nikos

This paper suggests specific experimental designs, criteria measures, and testing procedures for the empirical study of various field forces operative in the structure of the television picture. The purpose of the paper is twofold: first, to illustrate, through selected videotapes, the various field forces and, second, to provide specific…

Actual Change and Inaccurate Recall Contribute to Posttraumatic Growth following Radiotherapy

ERIC Educational Resources Information Center

Ransom, Sean; Sheldon, Kennon M.; Jacobsen, Paul B.

2008-01-01

People with cancer often report that they experience personal growth as a result of the disease, but such reports have unclear validity. Some suggest such growth results from Rogers's (1951) hypothesized organismic valuing process (OVP), an innate tendency for people to gravitate toward well-being; others suggest this growth may be a positive…

Do Dispositional Pessimism and Optimism Predict Ambulatory Blood Pressure During Schooldays and Nights in Adolescents?

PubMed Central

Räikkönen, Katri; Matthews, Karen A.

2010-01-01

We tested the hypotheses that (1) high pessimism and low optimism (LOT-R overall and subscale scores) would predict high ambulatory blood pressure (ABP) level and 24-hour load (percentage of ABP values exceeding the pediatric 95th percentile) among healthy Black and White adolescents (n = 201; 14–16 yrs) across 2 consecutive school days and (2) that the relationships for the pessimism and optimism subscales would show nonlinear effects. The hypotheses were confirmed for pessimism but not for optimism. The results suggest that high pessimism may have different effects than low optimism on ABP and that even moderate levels of pessimism may effect blood pressure regulation. These results suggest that optimism and pessimism are not the opposite poles on a single continuum but ought to be treated as separate constructs. PMID:18399951

Pubertal timing and sexual risk behaviors among rural African American male youth: testing a model based on life history theory.

PubMed

Kogan, Steven M; Cho, Junhan; Simons, Leslie Gordon; Allen, Kimberly A; Beach, Steven R H; Simons, Ronald L; Gibbons, Frederick X

2015-04-01

Life History Theory (LHT), a branch of evolutionary biology, describes how organisms maximize their reproductive success in response to environmental conditions. This theory suggests that challenging environmental conditions will lead to early pubertal maturation, which in turn predicts heightened risky sexual behavior. Although largely confirmed among female adolescents, results with male youth are inconsistent. We tested a set of predictions based on LHT with a sample of 375 African American male youth assessed three times from age 11 to age 16. Harsh, unpredictable community environments and harsh, inconsistent, or unregulated parenting at age 11 were hypothesized to predict pubertal maturation at age 13; pubertal maturation was hypothesized to forecast risky sexual behavior, including early onset of intercourse, substance use during sexual activity, and lifetime numbers of sexual partners. Results were consistent with our hypotheses. Among African American male youth, community environments were a modest but significant predictor of pubertal timing. Among those youth with high negative emotionality, both parenting and community factors predicted pubertal timing. Pubertal timing at age 13 forecast risky sexual behavior at age 16. Results of analyses conducted to determine whether environmental effects on sexual risk behavior were mediated by pubertal timing were not significant. This suggests that, although evolutionary mechanisms may affect pubertal development via contextual influences for sensitive youth, the factors that predict sexual risk behavior depend less on pubertal maturation than LHT suggests.

Progress in violence risk assessment and communication: hypothesis versus evidence.

PubMed

Harris, Grant T; Rice, Marnie E

2015-02-01

We draw a distinction between hypothesis and evidence with respect to the assessment and communication of the risk of violent recidivism. We suggest that some authorities in the field have proposed quite valid and reasonable hypotheses with respect to several issues. Among these are the following: that accuracy will be improved by the adjustment or moderation of numerical scores based on clinical opinions about rare risk factors or other considerations pertaining to the applicability to the case at hand; that there is something fundamentally distinct about protective factors so that they are not merely the obverse of risk factors, such that optimal accuracy cannot be achieved without consideration of such protective factors; and that assessment of dynamic factors is required for optimal accuracy and furthermore interventions aimed at such dynamic factors can be expected to cause reductions in violence risk. We suggest here that, while these are generally reasonable hypotheses, they have been inappropriately presented to practitioners as empirically supported facts, and that practitioners' assessment and communication about violence risk run beyond that supported by the available evidence as a result. We further suggest that this represents harm, especially in impeding scientific progress. Nothing here justifies stasis or simply surrendering to authoritarian custody with somatic treatment. Theoretically motivated and clearly articulated assessment and intervention should be provided for offenders, but in a manner that moves the field more firmly from hypotheses to evidence. Copyright © 2015 John Wiley & Sons, Ltd.

Archaeal Genome Organization and Stress Responses: Implications for the Origin and Evolution of Cellular Life

NASA Astrophysics Data System (ADS)

Musgrave, David; Zhang, Xiaoying; Dinger, Marcel

2002-08-01

For DNA to be used as an informational molecule it must exist in the cell on the edge of stability because all genomic processes require local controlled melting. This presents mechanistic opportunities and problems for genomic DNA from hyperthermophilic organisms, whose unpackaged DNA could melt at optimal temperatures for growth. Hyperthermophiles are suggested to employ the novel positively supercoiling topoisomerase enzyme reverse gyrase (RG) to form positively supercoiled DNA that is intrinsically resistant to thermal denaturation. RG is presently the only archaeal gene that is uniquely found in hyperthermophiles and therefore is central to hypotheses suggesting a hypothermophilic origin of life. However, the suggestion that RG has evolved by the fusion of two pre-existing enzymes has led to hypotheses for a lower temperature for the origin of life. In addition to the action of topoisomerases, DNA packaging and the intracellular ionic environment can also manipulate DNA topology significantly. In the Euryarchaeota, nucleosomes containing minimal histones can adopt two alternate DNA topologies in a salt-dependent manner. From this we hypothesize that since internal salt concentrations are increased following an increase in temperature, the genomic effects of temperature fluctuations could also be accommodated by changes in nucleosome organization. In addition, stress-induced changes in the nucleoid proteins could also play a role in maintaining the genome in the optimal topological state in changing environments. The function of these systems could therefore be central to temperature adaptation and thus be implicated in origin of life scenarios involving hyperthermophiles.

Action-related auditory ERP attenuation: Paradigms and hypotheses.

PubMed

Horváth, János

2015-11-11

A number studies have shown that the auditory N1 event-related potential (ERP) is attenuated when elicited by self-induced or self-generated sounds. Because N1 is a correlate of auditory feature- and event-detection, it was generally assumed that N1-attenuation reflected the cancellation of auditory re-afference, enabled by the internal forward modeling of the predictable sensory consequences of the given action. Focusing on paradigms utilizing non-speech actions, the present review summarizes recent progress on action-related auditory attenuation. Following a critical analysis of the most widely used, contingent paradigm, two further hypotheses on the possible causes of action-related auditory ERP attenuation are presented. The attention hypotheses suggest that auditory ERP attenuation is brought about by a temporary division of attention between the action and the auditory stimulation. The pre-activation hypothesis suggests that the attenuation is caused by the activation of a sensory template during the initiation of the action, which interferes with the incoming stimulation. Although each hypothesis can account for a number of findings, none of them can accommodate the whole spectrum of results. It is suggested that a better understanding of auditory ERP attenuation phenomena could be achieved by systematic investigations of the types of actions, the degree of action-effect contingency, and the temporal characteristics of action-effect contingency representation-buildup and -deactivation. This article is part of a Special Issue entitled SI: Prediction and Attention. Copyright © 2015. Published by Elsevier B.V.

Water-energy dynamics, habitat heterogeneity, history, and broad-scale patterns of mammal diversity

NASA Astrophysics Data System (ADS)

Ferrer-Castán, Dolores; Morales-Barbero, Jennifer; Vetaas, Ole R.

2016-11-01

Numerous hypotheses on diversity patterns are often presented as if they were mutually exclusive. However, because of multicollinearity, correlational analyses are not able to distinguish the causal effects of different factors on these patterns. For this reason, we examine the interrelationships among current climate, habitat heterogeneity and evolutionary history by partitioning the variation in both total and non-volant mammal species richness in the Iberian Peninsula. Thus, it is possible to determine the variation accounted for by each one of these three components that is not shared by the others, and the respective overlaps. More specifically, we hypothesize that (H1) in warm temperate zones, a small increase in the available energy has strong negative effects on mammal richness if water availability is limiting; (H2) there are functional relationships between woody plant species richness (WOOD) and the richness of mammal species; (H3) there is a signal of evolutionary history in contemporary patterns of species richness, and (H4) mammal richness and the historical variable mean root distance (MRD) respond to the same driving forces. Additionally, we also test for spatial autocorrelation. We found a sharp nonlinear decrease in mammal richness with increasing energy and a monotonic increase with increasing water availability. Moreover, an interaction term between these two climate factors appeared to be statistically significant, so H1 could not be rejected. WOOD remained significant after partialling out both current climate and MRD at the family level (MRDf), supporting H2. The relationship between mammal diversity and MRD averaged by species richness was found to be spurious, but there appeared a significant historical signal using MRDf (this supports H3). The overlaps among these factors are consistent with H4 and suggest that water-energy dynamics have probably been active drivers throughout evolutionary history with habitat heterogeneity, and biotic interactions playing an important role.

Standardization of the NEO-PI-3 in the Greek general population.

PubMed

Fountoulakis, Konstantinos N; Siamouli, Melina; Moysidou, Stefania; Pantoula, Eleonora; Moutou, Katerina; Panagiotidis, Panagiotis; Kemeridou, Marina; Mavridou, Eirini; Loli, Efimia; Batsiari, Elena; Preti, Antonio; Tondo, Leonardo; Gonda, Xenia; Mobayed, Nisreen; Akiskal, Kareen; Akiskal, Hagop; Costa, Paul; McCrae, Robert

2014-01-01

The revised NEO Personality Inventory (NEO-PI-3) includes 240 items corresponding to the Big Five personality traits (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience) and subordinate dimensions (facets). It is suitable for use with adolescents and adults (12 years or older). The aim of the current study was to validate the Greek translation of the NEO-PI-3 in the general Greek population. The study sample included 734 subjects from the general Greek population of whom 59.4% were females and 40.6% males aged 40.80 ± 11.48. The NEO-PI-3 was translated into Greek and back-translated into English, and the accuracy of the translation was confirmed and established. The statistical analysis included descriptive statistics, confirmatory factorial analysis (CFA), the calculation of Cronbach's alpha, and the calculation of Pearson product-moment correlations. Sociodemographics groups were compared by ANOVA. Most facets had Cronbach's alpha above 0.60. Confirmatory factor analysis showed acceptable loading of the facets on their own hypothesized factors and very good estimations of Cronbach's alphas for the hypothesized factors, so it was partially supportive of the five-factor structure of the NEO-PI-3.The factors extracted with Procrustes rotation analysis can be considered reasonably homologous to the factors of the American normative sample. Correlations between dimensions were as expected and similar to those reported in the literature. The literature suggests that overall, the psychometric properties of NEO-PI-3 scales have been found to generalize across ages, cultures, and methods of measurement. In accord with this, the results of the current study confirm the reliability of the Greek translation and adaptation of the NEO-PI-3. The inventory has comparable psychometric properties in its Greek version in comparison to the original and other national translations, and it is suitable for clinical as well as research use.

Testing co-evolutionary hypotheses over geological timescales: interactions between Mesozoic non-avian dinosaurs and cycads.

PubMed

Butler, Richard J; Barrett, Paul M; Kenrick, Paul; Penn, Malcolm G

2009-02-01

The significance of co-evolution over ecological timescales is well established, yet it remains unclear to what extent co-evolutionary processes contribute to driving large-scale evolutionary and ecological changes over geological timescales. Some of the most intriguing and pervasive long-term co-evolutionary hypotheses relate to proposed interactions between herbivorous non-avian dinosaurs and Mesozoic plants, including cycads. Dinosaurs have been proposed as key dispersers of cycad seeds during the Mesozoic, and temporal variation in cycad diversity and abundance has been linked to dinosaur faunal changes. Here we assess the evidence for proposed hypotheses of trophic and evolutionary interactions between these two groups using diversity analyses, a new database of Cretaceous dinosaur and plant co-occurrence data, and a geographical information system (GIS) as a visualisation tool. Phylogenetic evidence suggests that the origins of several key biological properties of cycads (e.g. toxins, bright-coloured seeds) likely predated the origin of dinosaurs. Direct evidence of dinosaur-cycad interactions is lacking, but evidence from extant ecosystems suggests that dinosaurs may plausibly have acted as seed dispersers for cycads, although it is likely that other vertebrate groups (e.g. birds, early mammals) also played a role. Although the Late Triassic radiations of dinosaurs and cycads appear to have been approximately contemporaneous, few significant changes in dinosaur faunas coincide with the late Early Cretaceous cycad decline. No significant spatiotemporal associations between particular dinosaur groups and cycads can be identified - GIS visualisation reveals disparities between the spatiotemporal distributions of some dinosaur groups (e.g. sauropodomorphs) and cycads that are inconsistent with co-evolutionary hypotheses. The available data provide no unequivocal support for any of the proposed co-evolutionary interactions between cycads and herbivorous dinosaurs - diffuse co-evolutionary scenarios that are proposed to operate over geological timescales are plausible, but such hypotheses need to be firmly grounded on direct evidence of interaction and may be difficult to support given the patchiness of the fossil record.

Multispacecraft Observations and 3D Structure of Electromagnetic Electron Phase-Space Holes

NASA Astrophysics Data System (ADS)

Holmes, J.; Ahmadi, N.; Ergun, R.; Wilder, F. D.; Newman, D. L.; Le Contel, O.; Torbert, R. B.; Burch, J. L.

2017-12-01

Electron phase-space holes are nonlinear plasma structures characterized by a unipolar trapping potential with a radial electric field. They commonly form from beam instabilities and other turbulent processes in many plasma environments. Due to their strong fields and long lifetimes, it has been hypothesized that phase-space holes can carry energy over long distances, contribute to large-scale currents, and accelerate individual particles to high energies. With electromagnetic field measurements at high cadence and precision on more than two spacecraft, we can compare the real 3D structure of electron phase-space holes to the models suggested by Andersson et al. (2009) and Treumann and Baumjohann (2012). In this case study, we consider a train of correlated electron phase-space holes observed by all four MMS spacecraft on the dusk flank within the magnetosphere. A number of the holes appear to pass directly through the 7 km tetrahedron formation. We use this data to compute the holes' phase velocity vector relative to the background magnetic field, and quantify their internal currents and associated magnetic moments. For these weak magnetic signatures, we find that the contribution from internal E×B0 currents is comparable to the v×E effect. This study will be interesting to compare with MMS observations in the magnetotail, which are expected to capture large, semi-relativistic phase-space holes with a strong magnetic component.

Breaking new ground in the mind: an initial study of mental brittle transformation and mental rigid rotation in science experts.

PubMed

Resnick, Ilyse; Shipley, Thomas F

2013-05-01

The current study examines the spatial skills employed in different spatial reasoning tasks, by asking how science experts who are practiced in different types of visualizations perform on different spatial tasks. Specifically, the current study examines the varieties of mental transformations. We hypothesize that there may be two broad classes of mental transformations: rigid body mental transformations and non-rigid mental transformations. We focus on the disciplines of geology and organic chemistry because different types of transformations are central to the two disciplines: While geologists and organic chemists may both confront rotation in the practice of their profession, only geologists confront brittle transformations. A new instrument was developed to measure mental brittle transformation (visualizing breaking). Geologists and organic chemists performed similarly on a measure of mental rotation, while geologists outperformed organic chemists on the mental brittle transformation test. The differential pattern of skill on the two tests for the two groups of experts suggests that mental brittle transformation and mental rotation are different spatial skills. The roles of domain general cognitive resources (attentional control, spatial working memory, and perceptual filling in) and strategy in completing mental brittle transformation are discussed. The current study illustrates how ecological and interdisciplinary approaches complement traditional cognitive science to offer a comprehensive approach to understanding the nature of spatial thinking.

Mental models accurately predict emotion transitions.

PubMed

Thornton, Mark A; Tamir, Diana I

2017-06-06

Successful social interactions depend on people's ability to predict others' future actions and emotions. People possess many mechanisms for perceiving others' current emotional states, but how might they use this information to predict others' future states? We hypothesized that people might capitalize on an overlooked aspect of affective experience: current emotions predict future emotions. By attending to regularities in emotion transitions, perceivers might develop accurate mental models of others' emotional dynamics. People could then use these mental models of emotion transitions to predict others' future emotions from currently observable emotions. To test this hypothesis, studies 1-3 used data from three extant experience-sampling datasets to establish the actual rates of emotional transitions. We then collected three parallel datasets in which participants rated the transition likelihoods between the same set of emotions. Participants' ratings of emotion transitions predicted others' experienced transitional likelihoods with high accuracy. Study 4 demonstrated that four conceptual dimensions of mental state representation-valence, social impact, rationality, and human mind-inform participants' mental models. Study 5 used 2 million emotion reports on the Experience Project to replicate both of these findings: again people reported accurate models of emotion transitions, and these models were informed by the same four conceptual dimensions. Importantly, neither these conceptual dimensions nor holistic similarity could fully explain participants' accuracy, suggesting that their mental models contain accurate information about emotion dynamics above and beyond what might be predicted by static emotion knowledge alone.

Connexin43 contributes to electrotonic conduction across scar tissue in the intact heart

NASA Astrophysics Data System (ADS)

Mahoney, Vanessa M.; Mezzano, Valeria; Mirams, Gary R.; Maass, Karen; Li, Zhen; Cerrone, Marina; Vasquez, Carolina; Bapat, Aneesh; Delmar, Mario; Morley, Gregory E.

2016-05-01

Studies have demonstrated non-myocytes, including fibroblasts, can electrically couple to myocytes in culture. However, evidence demonstrating current can passively spread across scar tissue in the intact heart remains elusive. We hypothesize electrotonic conduction occurs across non-myocyte gaps in the heart and is partly mediated by Connexin43 (Cx43). We investigated whether non-myocytes in ventricular scar tissue are electrically connected to surrounding myocardial tissue in wild type and fibroblast-specific protein-1 driven conditional Cx43 knock-out mice (Cx43fsp1KO). Electrical coupling between the scar and uninjured myocardium was demonstrated by injecting current into the myocardium and recording depolarization in the scar through optical mapping. Coupling was significantly reduced in Cx43fsp1KO hearts. Voltage signals were recorded using microelectrodes from control scars but no signals were obtained from Cx43fsp1KO hearts. Recordings showed significantly decreased amplitude, depolarized resting membrane potential, increased duration and reduced upstroke velocity compared to surrounding myocytes, suggesting that the non-excitable cells in the scar closely follow myocyte action potentials. These results were further validated by mathematical simulations. Optical mapping demonstrated that current delivered within the scar could induce activation of the surrounding myocardium. These data demonstrate non-myocytes in the scar are electrically coupled to myocytes, and coupling depends on Cx43 expression.

Neurotechnology for intelligence analysts

NASA Astrophysics Data System (ADS)

Kruse, Amy A.; Boyd, Karen C.; Schulman, Joshua J.

2006-05-01

Geospatial Intelligence Analysts are currently faced with an enormous volume of imagery, only a fraction of which can be processed or reviewed in a timely operational manner. Computer-based target detection efforts have failed to yield the speed, flexibility and accuracy of the human visual system. Rather than focus solely on artificial systems, we hypothesize that the human visual system is still the best target detection apparatus currently in use, and with the addition of neuroscience-based measurement capabilities it can surpass the throughput of the unaided human severalfold. Using electroencephalography (EEG), Thorpe et al1 described a fast signal in the brain associated with the early detection of targets in static imagery using a Rapid Serial Visual Presentation (RSVP) paradigm. This finding suggests that it may be possible to extract target detection signals from complex imagery in real time utilizing non-invasive neurophysiological assessment tools. To transform this phenomenon into a capability for defense applications, the Defense Advanced Research Projects Agency (DARPA) currently is sponsoring an effort titled Neurotechnology for Intelligence Analysts (NIA). The vision of the NIA program is to revolutionize the way that analysts handle intelligence imagery, increasing both the throughput of imagery to the analyst and overall accuracy of the assessments. Successful development of a neurobiologically-based image triage system will enable image analysts to train more effectively and process imagery with greater speed and precision.

The correlation between Prorocentrum donghaiense blooms and the Taiwan warm current in the East China Sea - evidence for the "Pelagic Seed Bank" hypothesis.

PubMed

Dai, Xinfeng; Lu, Douding; Guan, Weibing; Xia, Ping; Wang, Hongxia; He, Piaoxia; Zhang, Dongsheng

2013-01-01

During the last two decades, large-scale high biomass algal blooms of the dinoflagellate Prorocentrum donghaiense Lu have occurred frequently in the East China Sea (ECS). The role of increasing nutrient concentrations in driving those blooms is well-established, but the source population that initiates them is poorly understood. We hypothesized that the front of Taiwan Warm Current (TWC) may serve as a 'seed bank' that initiates P. donghaiense blooms in the ECS, as the physiochemical conditions in the TWC are suitable for the growth of P. donghaiense. In order to test this hypothesis, two surveys at different spatio-temporal scales were conducted in 2010 and 2011. We found a strong correlation in space and time between the abundance of P. donghaiense and the TWC. The spatial extent of the P. donghaiense bloom coincided with the TWC front in both 2010 and 2011. During the early development of the blooms, P. donghaiense concentration was highest at the TWC front, and then the bloom mass shifted inshore over the course of our 2011 survey. The TWC also moved inshore, albeit after the appearance of P. donghaiense. Overall, these results support our hypothesis that P. donghaiense blooms develop from the population at the TWC front in the ECS, suggesting the role of the ocean current front as a seed bank to dinoflagellate blooms.

Insulin Resistance as a Link between Amyloid-Beta and Tau Pathologies in Alzheimer’s Disease

PubMed Central

Mullins, Roger J.; Diehl, Thomas C.; Chia, Chee W.; Kapogiannis, Dimitrios

2017-01-01

Current hypotheses and theories regarding the pathogenesis of Alzheimer’s disease (AD) heavily implicate brain insulin resistance (IR) as a key factor. Despite the many well-validated metrics for systemic IR, the absence of biomarkers for brain-specific IR represents a translational gap that has hindered its study in living humans. In our lab, we have been working to develop biomarkers that reflect the common mechanisms of brain IR and AD that may be used to follow their engagement by experimental treatments. We present two promising biomarkers for brain IR in AD: insulin cascade mediators probed in extracellular vesicles (EVs) enriched for neuronal origin, and two-dimensional magnetic resonance spectroscopy (MRS) measures of brain glucose. As further evidence for a fundamental link between brain IR and AD, we provide a novel analysis demonstrating the close spatial correlation between brain expression of genes implicated in IR (using Allen Human Brain Atlas data) and tau and beta-amyloid pathologies. We proceed to propose the bold hypotheses that baseline differences in the metabolic reliance on glycolysis, and the expression of glucose transporters (GLUT) and insulin signaling genes determine the vulnerability of different brain regions to Tau and/or Amyloid beta (Aβ) pathology, and that IR is a critical link between these two pathologies that define AD. Lastly, we provide an overview of ongoing clinical trials that target IR as an angle to treat AD, and suggest how biomarkers may be used to evaluate treatment efficacy and target engagement. PMID:28515688

Form of the compensatory stepping response to repeated laterally directed postural disturbances.

PubMed

Hurt, Christopher P; Rosenblatt, Noah J; Grabiner, Mark D

2011-10-01

A compensatory stepping response (CSR) is a common strategy to restore dynamic stability in response to a postural disturbance. Currently, few studies have investigated the CSR to laterally directed disturbances delivered to subjects during quiet standing. The purpose of this study was to characterize the CSR of younger adults following exposure to a series of similar laterally directed disturbances for which no instructions were given with regard to the recovery response. We hypothesized that in the absence of externally applied constraints to the recovery response, subjects would be equally as likely to perform a crossover step as a sidestep sequence (SSS). We further hypothesized that there would be an asymmetry in arm abduction that would be dependent on the disturbance direction. Finally, we were interested in characterizing the effect of practice on the CSR to repeated disturbances. Ten younger adults were exposed to thirty laterally directed platform disturbances that forced a stepping response. Subjects responded by primarily utilizing a SSS that differs from previously reported results. Further, five of the ten subjects utilized a different recovery response that was dependent on the direction of the disturbance (i.e., left or right). Greater arm abduction was characterized for the arm in the direction of the external disturbance in comparison with the contralateral arm. Lastly, subjects modified their recovery response to this task within 12 disturbances. Taken together, these results suggest that recovery responses to laterally directed disturbances can be quickly modified but can be quite variable between and within subjects.

Panic attack history and anxiety sensitivity in relation to cognitive-based smoking processes among treatment-seeking daily smokers.

PubMed

Johnson, Kirsten A; Farris, Samantha G; Schmidt, Norman B; Smits, Jasper A J; Zvolensky, Michael J

2013-01-01

Empirical research has found that panic attacks are related to increased risk of more severe nicotine withdrawal and poor cessation outcome. Anxiety sensitivity (AS; fear of anxiety and related sensations) has similarly been found to be related to an increased risk of acute nicotine withdrawal and poorer cessation outcome. However, research has yet to examine the relative contributions of panic attacks and AS in terms of cognitive-based smoking processes (e.g., negative reinforcement smoking expectancies, addictive and negative affect-based reduction smoking motives, barriers to cessation, problem symptoms experienced while quitting). Participants (n = 242; 57.4% male; M (age) = 38.1) were daily smokers recruited as a part of a larger randomized control trial for smoking cessation. It was hypothesized that both panic attacks and AS would uniquely and independently predict the studied cognitive-based smoking processes. As hypothesized, AS was uniquely and positively associated with all smoking processes after controlling for average number of cigarettes smoked per day, current Axis I diagnosis, and participant sex. However, panic attack history was only significantly related to problem symptoms experienced while quitting smoking. Although past research has demonstrated significant associations between panic attacks and certain aspects of cigarette smoking (e.g., severity of nicotine withdrawal; lower abstinence rates, and negative affect reduction motives), the present findings suggest that AS may be more relevant to understanding beliefs about and motives for smoking behavior as well as perceptions of cessation-related difficulties.

Declines of the California red-legged frog: Climate, UV-B, habitat, and pesticides hypotheses

USGS Publications Warehouse

Davidson, C.; Shaffer, H.B.; Jennings, M.R.

2001-01-01

The federally threatened California red-legged frog (Rana aurora draytonii) has disappeared from much of its range for unknown reasons. We mapped 237 historic locations for the species and determined their current population status. Using a geographic information system (GIS), we determined latitude, elevation, and land use attributes for all sites and analyzed the spatial pattern of declines. We then compared the observed patterns of decline to those predicted by the climate change, UV-B radiation, pesticides, and habitat alteration hypotheses for amphibian decline. Declines were not consistent with the climate change hypothesis but showed a strong positive association with elevation, percentage upwind agricultural land use, and local urbanization. These results apply to patterns of decline across the entire range of R. a. draytonii in California, as well as within geographic subregions. The elevational gradient in declines is consistent with the UV-B hypothesis, although the UV-B hypothesis also predicts a north-to-south gradient in declines, which we did not observe. The association of declines with the amount of upwind agricultural land use strongly suggests that wind-borne agrochemicals may be an important factor in declines. This association was most pronounced within the Central Valley-Sierra region, where other studies have documented both transport and deposition of pesticides to the Sierra Nevada and the presence of pesticide residues in the bodies of congeneric (Rana muscosa) and more distantly related (Hyla regilla) frog species.

Drivers' social-work relationships as antecedents of unsafe driving: A social network perspective.

PubMed

Arizon Peretz, Renana; Luria, Gil

2017-09-01

In order to reduce road accidents rates, studies around the globe have attempted to shed light on the antecedents for unsafe road behaviors. The aim of the current research is to contribute to this literature by offering a new organizational antecedent of driver's unsafe behavior: The driver's relationships with his or her peers, as reflected in three types of social networks: negative relationships network, friendship networks and advice networks (safety consulting). We hypothesized that a driver's position in negative relationship networks, friendship networks, and advice networks will predict unsafe driving. Additionally, we hypothesized the existence of mutual influences among the driver's positions in these various networks, and suggested that the driver's positions interact to predict unsafe driving behaviors. The research included 83 professional drivers from four different organizations. Driving behavior data were gathered via the IVDR (In-Vehicle Data Recorder) system, installed in every truck to measure and record the driver's behavior. The findings indicated that the drivers' position in the team networks predicts safe driving behavior: Centrality in negative relationship networks is positively related to unsafe driving, and centrality in friendship networks is negatively related to unsafe driving, while centrality in advice networks is not related to unsafe driving. Furthermore, we found an interaction effect between negative network centrality and centrality in friendship networks. The relation between negative networks and unsafe behavior is weaker when high levels of friendship network centrality exist. The implications will be presented in the Discussion section. Copyright © 2017 Elsevier Ltd. All rights reserved.