The impact of threat of shock on the framing effect and temporal discounting: executive functions unperturbed by acute stress?

PubMed

Robinson, Oliver J; Bond, Rebecca L; Roiser, Jonathan P

2015-01-01

Anxiety and stress-related disorders constitute a large global health burden, but are still poorly understood. Prior work has demonstrated clear impacts of stress upon basic cognitive function: biasing attention toward unexpected and potentially threatening information and instantiating a negative affective bias. However, the impact that these changes have on higher-order, executive, decision-making processes is unclear. In this study, we examined the impact of a translational within-subjects stress induction (threat of unpredictable shock) on two well-established executive decision-making biases: the framing effect (N = 83), and temporal discounting (N = 36). In both studies, we demonstrate (a) clear subjective effects of stress, and (b) clear executive decision-making biases but (c) no impact of stress on these decision-making biases. Indeed, Bayes factor analyses confirmed substantial preference for decision-making models that did not include stress. We posit that while stress may induce subjective mood change and alter low-level perceptual and action processes (Robinson et al., 2013c), some higher-level executive processes remain unperturbed by these impacts. As such, although stress can induce a transient affective biases and altered mood, these need not result in poor financial decision-making.

Risk-prone individuals prefer the wrong options on a rat version of the Iowa Gambling Task.

PubMed

Rivalan, Marion; Ahmed, Serge H; Dellu-Hagedorn, Françoise

2009-10-15

Decision making in complex and conflicting situations, as measured in the widely used Iowa Gambling Task (IGT), can be profoundly impaired in psychiatric disorders, such as attention-deficit/hyperactivity disorder, drug addiction, and also in healthy individuals for whom immediate gratification prevails over long-term gain. The cognitive processes underlying these deficits are poorly understood, in part due to a lack of suitable animal models assessing complex decision making with good construct validity. We developed a rat gambling task analogous to the IGT that tracks, for the first time, the ongoing decision process within a single session in an operant cage. Rats could choose between various options. Disadvantageous options, as opposed to advantageous ones, offered bigger immediate food reward but were followed by longer, unpredictable penalties (time-out). The majority of rats can evaluate and deduce favorable options more or less rapidly according to task complexity, whereas others systematically choose disadvantageously. These interindividual differences are stable over time and do not depend on task difficulty or on the level of food restriction. We find that poor decision making does not result from a failure to acquire relevant information but from hypersensitivity to reward and higher risk taking in anxiogenic situations. These results suggest that rats, as well as human poor performers, share similar traits to those observed in decision-making related psychiatric disorders. These traits could constitute risk factors of developing such disorders. The rapid identification of poor decision makers using the rat gambling task should promote the discovery of the specific brain dysfunctions that cause maladapted decision making.

Low Cognitive Impulsivity Is Associated with Better Gain and Loss Learning in a Probabilistic Decision-Making Task

PubMed Central

Cáceres, Pablo; San Martín, René

2017-01-01

Many advances have been made over the last decades in describing, on the one hand, the link between reward-based learning and decision-making, and on the other hand, the link between impulsivity and decision-making. However, the association between reward-based learning and impulsivity remains poorly understood. In this study, we evaluated the association between individual differences in loss-minimizing and gain-maximizing behavior in a learning-based probabilistic decision-making task and individual differences in cognitive impulsivity. We found that low cognitive impulsivity was associated both with a better performance minimizing losses and maximizing gains during the task. These associations remained significant after controlling for mathematical skills and gender as potential confounders. We discuss potential mechanisms through which cognitive impulsivity might interact with reward-based learning and decision-making. PMID:28261137

Low Cognitive Impulsivity Is Associated with Better Gain and Loss Learning in a Probabilistic Decision-Making Task.

PubMed

Cáceres, Pablo; San Martín, René

2017-01-01

Many advances have been made over the last decades in describing, on the one hand, the link between reward-based learning and decision-making, and on the other hand, the link between impulsivity and decision-making. However, the association between reward-based learning and impulsivity remains poorly understood. In this study, we evaluated the association between individual differences in loss-minimizing and gain-maximizing behavior in a learning-based probabilistic decision-making task and individual differences in cognitive impulsivity. We found that low cognitive impulsivity was associated both with a better performance minimizing losses and maximizing gains during the task. These associations remained significant after controlling for mathematical skills and gender as potential confounders. We discuss potential mechanisms through which cognitive impulsivity might interact with reward-based learning and decision-making.

Expected utility violations evolve under status-based selection mechanisms.

PubMed

Dickson, Eric S

2008-10-07

The expected utility theory of decision making under uncertainty, a cornerstone of modern economics, assumes that humans linearly weight "utilities" for different possible outcomes by the probabilities with which these outcomes occur. Despite the theory's intuitive appeal, both from normative and from evolutionary perspectives, many experiments demonstrate systematic, though poorly understood, patterns of deviation from EU predictions. This paper offers a novel theoretical account of such patterns of deviation by demonstrating that EU violations can emerge from evolutionary selection when individual "status" affects inclusive fitness. In humans, battles for resources and social standing involve high-stakes decision making, and assortative mating ensures that status matters for fitness outcomes. The paper therefore proposes grounding the study of decision making under uncertainty in an evolutionary game-theoretic framework.

Economic inequality increases risk taking.

PubMed

Payne, B Keith; Brown-Iannuzzi, Jazmin L; Hannay, Jason W

2017-05-02

Rising income inequality is a global trend. Increased income inequality has been associated with higher rates of crime, greater consumer debt, and poorer health outcomes. The mechanisms linking inequality to poor outcomes among individuals are poorly understood. This research tested a behavioral account linking inequality to individual decision making. In three experiments ( n = 811), we found that higher inequality in the outcomes of an economic game led participants to take greater risks to try to achieve higher outcomes. This effect of unequal distributions on risk taking was driven by upward social comparisons. Next, we estimated economic risk taking in daily life using large-scale data from internet searches. Risk taking was higher in states with greater income inequality, an effect driven by inequality at the upper end of the income distribution. Results suggest that inequality may promote poor outcomes, in part, by increasing risky behavior.

Sources of heavy metals in urban wastewater in Stockholm.

PubMed

Sörme, L; Lagerkvist, R

2002-10-21

The sources of heavy metals to a wastewater treatment plant was investigated. Sources can be actual goods, e.g. runoff from roofs, wear of tires, food, or activities, e.g. large enterprises, car washes. The sources were identified by knowing the metals content in various goods and the emissions from goods to sewage or stormwater. The sources of sewage water and stormwater were categorized to enable comparison with other research and measurements. The categories were households, drainage water, businesses, pipe sediment (all transported in sewage water), atmospheric deposition, traffic, building materials and pipe sediment (transported in stormwater). Results show that it was possible to track the sources of heavy metals for some metals such as Cu and Zn (110 and 100% found, respectively) as well as Ni and Hg (70% found). Other metals sources are still poorly understood or underestimated (Cd 60%, Pb 50%, Cr 20% known). The largest sources of Cu were tap water and roofs. For Zn the largest sources were galvanized material and car washes. In the case of Ni, the largest sources were chemicals used in the WTP and drinking water itself. And finally, for Hg the most dominant emission source was the amalgam in teeth. For Pb, Cr and Cd, where sources were more poorly understood, the largest contributors for all were car washes. Estimated results of sources from this study were compared with previously done measurements. The comparison shows that measured contribution from households is higher than that estimated (except Hg), leading to the conclusion that the sources of sewage water from households are still poorly understood or that known sources are underestimated. In the case of stormwater, the estimated contributions are rather well in agreement with measured contributions, although uncertainties are large for both estimations and measurements. Existing pipe sediments in the plumbing system, which release Hg and Pb, could be one explanation for the missing amount of these metals. Large enterprises were found to make a very small contribution, 4% or less for all metals studied. Smaller enterprises (with the exception of car washes) have been shown to make a small contribution in another city; the contribution in this case study is still unknown.

Economic inequality increases risk taking

PubMed Central

Payne, B. Keith; Brown-Iannuzzi, Jazmin L.; Hannay, Jason W.

2017-01-01

Rising income inequality is a global trend. Increased income inequality has been associated with higher rates of crime, greater consumer debt, and poorer health outcomes. The mechanisms linking inequality to poor outcomes among individuals are poorly understood. This research tested a behavioral account linking inequality to individual decision making. In three experiments (n = 811), we found that higher inequality in the outcomes of an economic game led participants to take greater risks to try to achieve higher outcomes. This effect of unequal distributions on risk taking was driven by upward social comparisons. Next, we estimated economic risk taking in daily life using large-scale data from internet searches. Risk taking was higher in states with greater income inequality, an effect driven by inequality at the upper end of the income distribution. Results suggest that inequality may promote poor outcomes, in part, by increasing risky behavior. PMID:28416655

Making sense by making sentient: effectance motivation increases anthropomorphism.

PubMed

Waytz, Adam; Morewedge, Carey K; Epley, Nicholas; Monteleone, George; Gao, Jia-Hong; Cacioppo, John T

2010-09-01

People commonly anthropomorphize nonhuman agents, imbuing everything from computers to pets to gods with humanlike capacities and mental experiences. Although widely observed, the determinants of anthropomorphism are poorly understood and rarely investigated. We propose that people anthropomorphize, in part, to satisfy effectance motivation-the basic and chronic motivation to attain mastery of one's environment. Five studies demonstrated that increasing effectance motivation by manipulating the perceived unpredictability of a nonhuman agent or by increasing the incentives for mastery increases anthropomorphism. Neuroimaging data demonstrated that the neural correlates of this process are similar to those engaged when mentalizing other humans. A final study demonstrated that anthropomorphizing a stimulus makes it appear more predictable and understandable, suggesting that anthropomorphism satisfies effectance motivation. Anthropomorphizing nonhuman agents seems to satisfy the basic motivation to make sense of an otherwise uncertain environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Frustration influences impact of history and disciplinary attitudes on physical discipline decision making.

PubMed

Russa, Mary B; Rodriguez, Christina M; Silvia, Paul J

2014-01-01

Although intergenerational patterns of punitive physical punishment garner considerable research attention, the mechanisms by which historical, cognitive, and contextual factors interplay to influence disciplinary responding remains poorly understood. Disciplinary attitudes have been shown to mediate the association between disciplinary history and disciplinary responding. The present study investigated whether frustration influences these mediation effects. Half of a sample of 330 undergraduates was randomly assigned to frustration induction. Structural equation modeling confirmed that, for participants in the frustration condition, the relation between disciplinary history and physical discipline decision-making was fully mediated by attitudes approving physical discipline. In contrast, for respondents in the no-frustration condition, the pathway from disciplinary history to discipline decision-making was only partially mediated by attitudes. Under conditions of frustration, attitudes may become a more central means by which personal disciplinary history is associated with disciplinary decision-making. © 2013 Wiley Periodicals, Inc.

Genetically Engineered Mouse Models of Pituitary Tumors

PubMed Central

Cano, David A.; Soto-Moreno, Alfonso; Leal-Cerro, Alfonso

2014-01-01

Animal models constitute valuable tools for investigating the pathogenesis of cancer as well as for preclinical testing of novel therapeutics approaches. However, the pathogenic mechanisms of pituitary-tumor formation remain poorly understood, particularly in sporadic adenomas, thus, making it a challenge to model pituitary tumors in mice. Nevertheless, genetically engineered mouse models (GEMMs) of pituitary tumors have provided important insight into pituitary tumor biology. In this paper, we review various GEMMs of pituitary tumors, highlighting their contributions and limitations, and discuss opportunities for research in the field. PMID:25136513

Neural architecture of hunger-dependent multisensory decision making in C. elegans

PubMed Central

Ghosh, D. Dipon; Sanders, Tom; Hong, Soonwook; McCurdy, Li Yan; Chase, Daniel L.; Cohen, Netta; Koelle, Michael R.; Nitabach, Michael N.

2016-01-01

SUMMARY Little is known about how animals integrate multiple sensory inputs in natural environments to balance avoidance of danger with approach to things of value. Furthermore, the mechanistic link between internal physiological state and threat-reward decision making remains poorly understood. Here we confronted C. elegans worms with the decision whether to cross a hyperosmotic barrier presenting the threat of desiccation to reach a source of food odor. We identified a specific interneuron that controls this decision via top-down extrasynaptic aminergic potentiation of the primary osmosensory neurons to increase their sensitivity to the barrier. We also establish that food deprivation increases the worm’s willingness to cross the dangerous barrier by suppressing this pathway. These studies reveal a potentially general neural circuit architecture for internal state control of threat-reward decision making. PMID:27866800

Temporal competition between differentiation programs determines cell fate choice

NASA Astrophysics Data System (ADS)

Kuchina, Anna; Espinar, Lorena; Cagatay, Tolga; Balbin, Alejandro; Alvarado, Alma; Garcia-Ojalvo, Jordi; Suel, Gurol

2011-03-01

During pluripotent differentiation, cells adopt one of several distinct fates. The dynamics of this decision-making process are poorly understood, since cell fate choice may be governed by interactions between differentiation programs that are active at the same time. We studied the dynamics of decision-making in the model organism Bacillus subtilis by simultaneously measuring the activities of competing differentiation programs (sporulation and competence) in single cells. We discovered a precise switch-like point of cell fate choice previously hidden by cell-cell variability. Engineered artificial crosslinks between competence and sporulation circuits revealed that the precision of this choice is generated by temporal competition between the key players of two differentiation programs. Modeling suggests that variable progression towards a switch-like decision might represent a general strategy to maximize adaptability and robustness of cellular decision-making.

Self-expanding stent for spontaneous coronary artery dissection: a rational choice.

PubMed

Mele, Marco; Langialonga, Tommaso; Maggi, Alessandro; Villella, Massimo; Villella, Alessandro

2016-12-01

: Spontaneous coronary artery dissection (SCAD) is a rare and poorly understood cause of acute coronary syndrome in relatively young patients. Nowadays, the optimal treatment of SCAD is uncertain. A conservative approach seems to be preferable, but in particular conditions, an invasive strategy is necessary. The poor rate of procedural success, the high risk of procedural complications and the uncertain long and mid-term results make the interventional treatment of SCAD a challenge. We report a case of a young male patient presenting with SCAD successfully treated with a sirolimus-eluting self-expanding coronary stent. To our knowledge, the use of self-expanding coronary stent for SCAD has never been described yet and we discuss about the rationale of a possible larger use in clinical practice.

The Importance Of Integrating Narrative Into Health Care Decision Making.

PubMed

Dohan, Daniel; Garrett, Sarah B; Rendle, Katharine A; Halley, Meghan; Abramson, Corey

2016-04-01

When making health care decisions, patients and consumers use data but also gather stories from family and friends. When advising patients, clinicians consult the medical evidence but also use professional judgment. These stories and judgments, as well as other forms of narrative, shape decision making but remain poorly understood. Furthermore, qualitative research methods to examine narrative are rarely included in health science research. We illustrate how narratives shape decision making and explain why it is difficult but necessary to integrate qualitative research on narrative into the health sciences. We draw on social-scientific insights on rigorous qualitative research and our ongoing studies of decision making by patients with cancer, and we describe new tools and approaches that link qualitative research findings with the predominantly quantitative health science scholarship. Finally, we highlight the benefits of more fully integrating qualitative research and narrative analysis into the medical evidence base and into evidence-based medical practice. Project HOPE—The People-to-People Health Foundation, Inc.

Should Social Value Obligations be Local or Global?

PubMed

Nayak, Rahul; Shah, Seema K

2017-02-01

According to prominent bioethics scholars and international guidelines, researchers and sponsors have obligations to ensure that the products of their research are reasonably available to research participants and their communities. In other words, the claim is that research is unethical unless it has local social value. In this article, we argue that the existing conception of reasonable availability should be replaced with a social value obligation that extends to the global poor (and not just research participants and host communities). To the extent the social value requirement has been understood as geographically constrained to the communities that host research and the countries that can afford the products of research, it has neglected to include the global poor as members of the relevant society. We argue that a new conception of social value obligations is needed for two reasons. First, duties of global beneficence give reason for researchers, sponsors, and institutions to take steps to make their products more widely accessible. Second, public commitments made by many institutions acknowledge and engender responsibilities to make the products of research more accessible to the global poor. Future research is needed to help researchers and sponsors discharge these obligations in ways that unlock their full potential. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Composite collective decision-making

PubMed Central

Czaczkes, Tomer J.; Czaczkes, Benjamin; Iglhaut, Carolin; Heinze, Jürgen

2015-01-01

Individual animals are adept at making decisions and have cognitive abilities, such as memory, which allow them to hone their decisions. Social animals can also share information. This allows social animals to make adaptive group-level decisions. Both individual and collective decision-making systems also have drawbacks and limitations, and while both are well studied, the interaction between them is still poorly understood. Here, we study how individual and collective decision-making interact during ant foraging. We first gathered empirical data on memory-based foraging persistence in the ant Lasius niger. We used these data to create an agent-based model where ants may use social information (trail pheromones), private information (memories) or both to make foraging decisions. The combined use of social and private information by individuals results in greater efficiency at the group level than when either information source was used alone. The modelled ants couple consensus decision-making, allowing them to quickly exploit high-quality food sources, and combined decision-making, allowing different individuals to specialize in exploiting different resource patches. Such a composite collective decision-making system reaps the benefits of both its constituent parts. Exploiting such insights into composite collective decision-making may lead to improved decision-making algorithms. PMID:26019155

Postgraduate nursing student knowledge, attitudes, skills, and confidence in appropriately referencing academic work.

PubMed

Greenwood, Melanie; Walkem, Kerrie; Smith, Lindsay Mervyn; Shearer, Toniele; Stirling, Christine

2014-08-01

Preventing plagiarism is an ongoing issue for higher education institutions. Although plagiarism has been traditionally seen as cheating, it is increasingly thought to be the result of poor referencing, with students reporting difficulties citing and referencing bibliographic sources. This study examined the academic knowledge, attitude, skills, and confidence of students in a school of nursing to understand poor referencing. A cross-sectional quantitative and qualitative survey was distributed to postgraduate (N = 1,000) certificate, diploma, and master's students. Quantitative data gathered demographics, cultural and linguistic background, and use of technology. Thematic analysis discovered patterns and themes. Results showed participants understood requirements for referencing; half indicated poor referencing was due to difficulty referencing Internet sources or losing track of sources, and many lacked confidence in key referencing tasks. Despite this, 50% did not make use of referencing resources. Overall, these data suggest incorrect referencing is rarely intentional and predominantly caused by skills deficit. Copyright 2014, SLACK Incorporated.

Laboratory tests for mumps vaccines.

PubMed

Minor, P D

1997-03-01

The action of live attenuated vaccines against mumps is poorly understood although their clinical efficacy is beyond doubt. The attenuated character of the vaccine is assured by consistency of production related to clinical trials, and limited studies of vaccine seeds in primates. Potency is assessed by infectivity in vitro and is subject to poorly understood sources of variation. Molecular biological studies are at an early stage.

Tailoring Medulloblastoma Treatment Through Genomics: Making a Change, One Subgroup at a Time.

PubMed

Holgado, Borja L; Guerreiro Stucklin, Ana; Garzia, Livia; Daniels, Craig; Taylor, Michael D

2017-08-31

After more than a decade of genomic studies in medulloblastoma, the time has come to capitalize on the knowledge gained and use it to directly improve patient care. Although metastatic and relapsed disease remain poorly understood, much has changed in how we define medulloblastoma, and it has become evident that with conventional therapies, specific groups of patients are currently under- or overtreated. In this review, we summarize the latest insights into medulloblastoma biology, focusing on how genomics is affecting patient stratification, informing preclinical studies of targeted therapies, and shaping the new generation of clinical trials.

Thermal Cycling Fatigue in DIPs Mounted with Eutectic Tin-Lead Solder Joints in Stub and Gullwing Geometries

NASA Technical Reports Server (NTRS)

Winslow, J. W.; Silveira, C. de

1993-01-01

It has long been known that solder joints under mechanical stress are subject to failure. In early electronic systems, such failures were avoided primarily by avoiding the use of solder as a mechanical structural component. The rule was first to make sound wire connections that did not depend mechanically on solder, and only then to solder them. Careful design and miniaturization in modern electronic systems limits the mechanical stresses exerted on solder joints to values less than their yield points, and these joints have become integral parts of the mechanical structures. Unfortunately, while these joints are strong enough when new, they have proven vulnerable to fatigue failures as they age. Details of the fatigue process are poorly understood, making predictions of expected lifetimes difficult.

Composite collective decision-making.

PubMed

Czaczkes, Tomer J; Czaczkes, Benjamin; Iglhaut, Carolin; Heinze, Jürgen

2015-06-22

Individual animals are adept at making decisions and have cognitive abilities, such as memory, which allow them to hone their decisions. Social animals can also share information. This allows social animals to make adaptive group-level decisions. Both individual and collective decision-making systems also have drawbacks and limitations, and while both are well studied, the interaction between them is still poorly understood. Here, we study how individual and collective decision-making interact during ant foraging. We first gathered empirical data on memory-based foraging persistence in the ant Lasius niger. We used these data to create an agent-based model where ants may use social information (trail pheromones), private information (memories) or both to make foraging decisions. The combined use of social and private information by individuals results in greater efficiency at the group level than when either information source was used alone. The modelled ants couple consensus decision-making, allowing them to quickly exploit high-quality food sources, and combined decision-making, allowing different individuals to specialize in exploiting different resource patches. Such a composite collective decision-making system reaps the benefits of both its constituent parts. Exploiting such insights into composite collective decision-making may lead to improved decision-making algorithms. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Supporting Pakistani and Chinese families with young children: perspectives of mothers and health visitors.

PubMed

Hogg, R; de Kok, B; Netto, G; Hanley, J; Haycock-Stuart, E

2015-05-01

In the UK, public health nurses (health visitors) provide support and advice to families with young children, including those from minority ethnic communities. While the need for cultural sensitivity is being increasingly recognized, the factors which contribute to this sensitivity are poorly understood. The Pakistani and Chinese communities constitute the two largest minority ethnic groups in Scotland. This study explored Pakistani and Chinese women's experience of motherhood and of the health visiting service and public health nurses' experiences of working with Chinese and Pakistani mothers. Semi-structured individual interviews were carried out with 16 Pakistani and 15 Chinese mothers. Eight health visitors took part in two focus groups. The study was undertaken in an urban area of Scotland. Data were analysed thematically. Chinese and Pakistani mothers negotiate complex processes in order to ensure that their children maintain their own ethnic identity while fitting in with their peers in their adopted country. Health visitors were seen as supportive, although sometimes advice and information given was culturally inappropriate, and their role was often poorly understood. Health visitors were anxious to be sensitive to families' religious and cultural beliefs. Cultural sensitivity is an important factor in providing appropriate advice and help to Pakistani and Chinese families, and involves health visitors in considering views and practices on parenting which may differ across cultures, including their own. Family characteristics need to be understood on an individual basis, rather than making assumptions about clients' cultural norms and lifestyles. This is best achieved by exploring with mothers if they understand the advice and information they are being offered and also if it is appropriate to their cultural and religious beliefs. © 2014 John Wiley & Sons Ltd.

Translation of Real-Time Infectious Disease Modeling into Routine Public Health Practice

PubMed Central

Chughtai, Abrar A.; Heywood, Anita; Gardner, Lauren M.; Heslop, David J.; MacIntyre, C. Raina

2017-01-01

Infectious disease dynamic modeling can support outbreak emergency responses. We conducted a workshop to canvas the needs of stakeholders in Australia for practical, real-time modeling tools for infectious disease emergencies. The workshop was attended by 29 participants who represented government, defense, general practice, and academia stakeholders. We found that modeling is underused in Australia and its potential is poorly understood by practitioners involved in epidemic responses. The development of better modeling tools is desired. Ideal modeling tools for operational use would be easy to use, clearly indicate underlying parameterization and assumptions, and assist with policy and decision making. PMID:28418309

Preservation of Fertility Potential for Gender and Sex Diverse Individuals.

PubMed

Johnson, Emilie K; Finlayson, Courtney

2016-01-01

Gender and sex diverse individuals-transgender individuals and those with disorders of sex development (DSD)-both face medical treatments that may impair biological fertility potential. Young DSD patients also often have abnormal gonadal development. Fertility preservation for these populations has historically been poorly understood and rarely addressed. Future fertility should be discussed with gender and sex diverse individuals, particularly given recent advances in fertility preservation technologies and evolving views of fertility potential. Key ethical issues include parental proxy decision-making and uncertainty regarding prepubertal fertility preservation technologies. Many opportunities exist for advancing fertility-related care and research for transgender and DSD patients.

Arcus: Observatory Science

NASA Astrophysics Data System (ADS)

Valencic, Lynne; Arcus Team

2018-01-01

Arcus is a free-flying MIDEX satellite selected for Phase A and planned to launch in 2023. Its bandpass (~12-50 Å), high resolution (R > 2500 between 22-25 Å), and effective area (450 cm2 between 22-25 Å) make it ideal for studying numerous systems after its baseline mission concludes in 2026. For instance, hot star winds show strong but poorly understood variable spectra, as do cataclysmic variables and super-soft sources that may be the progenitors of Type Ia supernovae, and the nature of the ISM is still not well known. Arcus will also allow observations of small extended sources like supernova remnants and planetary nebulae.

Disorders of Excessive Daytime Sleepiness Including Narcolepsy and Idiopathic Hypersomnia.

PubMed

Berkowski, Joseph Andrew; Shelgikar, Anita Valanju

2016-09-01

Central disorders of hypersomnolence are rare conditions with a poorly understood pathophysiology, making the identification and management challenging for sleep clinicians. Clinical history is essential for ruling out secondary causes of hypersomnolence and distinguishing among diagnoses. Current diagnostic criteria rely heavily on the polysomnogram and multiple sleep latency test. The current focus of treatment of hypersomnolence is on drugs that promote alertness. Additionally, in the case of narcolepsy type 1, medication management addresses control of cataplexy, the hallmark symptom of this disorder. Elucidation of pathophysiology of these disorders in the future will be essential to better categorization and management. Published by Elsevier Inc.

Hypersomnia: Evaluation, Treatment, and Social and Economic Aspects.

PubMed

Saini, Prabhjyot; Rye, David B

2017-03-01

Most central disorders of hypersomnolence are conditions with poorly understood pathophysiologies, making their identification, treatment, and management challenging for sleep clinicians. The most challenging to diagnose and treat is idiopathic hypersomnia. There are no FDA-approved treatments, and off-label usage of narcolepsy treatments seldom provide benefit. Patients are largely left on their own to alleviate the compound effects of this disorder on their quality of life. This review covers the major points regarding clinical features and diagnosis of idiopathic hypersomnia, reviews current evidence supporting the available treatment options, and discusses the psychosocial impact and effects of idiopathic hypersomnia. Copyright © 2016 Elsevier Inc. All rights reserved.

Manuscript peer review at the AJR: facts, figures, and quality assessment.

PubMed

Friedman, D P

1995-04-01

Concern by the government, funding institutions, and the public for quality assurance in all aspects of medical endeavors mandates critical examination of various professional activities. Although peer review is generally regarded as the best system for selecting and improving scientific papers for publication, the efficacy of this process has never been proved. Moreover, the administrative functions of the editorial staff are often poorly understood. The purpose of this article is to make peer review a the AJR less esoteric and more understandable by quantifying some of its activities. This information is then assessed as it relates to the quality of this important step in scientific publication.

Engagement in decision-making and patient satisfaction: a qualitative study of older patients' perceptions of dialysis initiation and modality decisions.

PubMed

Ladin, Keren; Lin, Naomi; Hahn, Emily; Zhang, Gregory; Koch-Weser, Susan; Weiner, Daniel E

2017-08-01

Although shared decision-making (SDM) can better align patient preferences with treatment, barriers remain incompletely understood and the impact on patient satisfaction is unknown. This is a qualitative study with semistructured interviews. A purposive sample of prevalent dialysis patients ≥65 years of age at two facilities in Greater Boston were selected for diversity in time from initiation, race, modality and vintage. A codebook was developed and interrater reliability was 89%. Codes were discussed and organized into themes. A total of 31 interviews with 23 in-center hemodialysis patients, 1 home hemodialysis patient and 7 peritoneal dialysis patients were completed. The mean age was 76 ± 9 years. Two dominant themes (with related subthemes) emerged: decision-making experiences and satisfaction, and barriers to SDM. Subthemes included negative versus positive decision-making experiences, struggling for autonomy, being a 'good patient' and lack of choice. In spite of believing that dialysis initiation should be the patient's choice, no patients perceived that they had made a choice. Patients explained that this is due to the perception of imminent death or that the decision to start dialysis belonged to physicians. Clinicians and family frequently overrode patient preferences, with patient autonomy honored mostly to select dialysis modality. Poor decision-making experiences were associated with low treatment satisfaction. Despite recommendations for SDM, many older patients were unaware that dialysis initiation was voluntary, held mistaken beliefs about their prognosis and were not engaged in decision-making, resulting in poor satisfaction. Patients desired greater information, specifically focusing on the acuity of their choice, prognosis and goals of care. © The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

From Blame to Punishment: Disrupting Prefrontal Cortex Activity Reveals Norm Enforcement Mechanisms.

PubMed

Buckholtz, Joshua W; Martin, Justin W; Treadway, Michael T; Jan, Katherine; Zald, David H; Jones, Owen; Marois, René

2015-09-23

The social welfare provided by cooperation depends on the enforcement of social norms. Determining blameworthiness and assigning a deserved punishment are two cognitive cornerstones of norm enforcement. Although prior work has implicated the dorsolateral prefrontal cortex (DLPFC) in norm-based judgments, the relative contribution of this region to blameworthiness and punishment decisions remains poorly understood. Here, we used repetitive transcranial magnetic stimulation (rTMS) and fMRI to determine the specific role of DLPFC function in norm-enforcement behavior. DLPFC rTMS reduced punishment for wrongful acts without affecting blameworthiness ratings, and fMRI revealed punishment-selective DLPFC recruitment, suggesting that these two facets of norm-based decision making are neurobiologically dissociable. Finally, we show that DLPFC rTMS affects punishment decision making by altering the integration of information about culpability and harm. Together, these findings reveal a selective, causal role for DLPFC in norm enforcement: representational integration of the distinct information streams used to make punishment decisions. Copyright © 2015 Elsevier Inc. All rights reserved.

Lab Astro and the Origins of the Chemical Elements

NASA Astrophysics Data System (ADS)

Lawler, James E.

2010-03-01

Interpretation of the spectra of metal-poor Galactic halo stars is dependent on AMO laboratory data [1,2]. Metal-poor Galactic halo stars were born when the Milky Way was young and they provide a record of the chemical evolution of the Galaxy. Elements heavier than iron are produced via r(apid)-process and s(low)-process n(eutron)-capture mechanisms. The s-process mechanism, which occurs in certain AGB stars, is relatively well understood. The explosive r-process is not well understood. The r-process n-capture mechanism was dominant early in the Galaxy's history [3]. New large aperture telescopes make it possible to record high-resolution spectra with high signal-to-noise ratios on a growing number of metal-poor stars. In addition to mapping the chemical evolution of the Galaxy, these studies are yielding an increasingly well-defined r-process elemental abundance pattern which constrains models of r-process nucleosynthesis [1]. The next phase of this ongoing research will address challenges in modeling stellar photospheres. Peculiar trends in abundances of specific Fe-group elements as a function of stellar age or metallicity may be due to limitations in traditional one dimensional (1d) local thermodynamic equilibrium (LTE) models of stellar photospheres or may be due to poorly understood nucleosynthesis [4]. Efforts are now underway to test the Saha or ionization equilibrium in a variety of stellar atmospheres for several Fe-group elements using the best available spectroscopic data for selected transitions. More comprehensive spectroscopic data of improved accuracy and accurate collisional data, especially for inelastic collisions of H atoms with metal atoms and ions, will be needed to fully develop 3d/non-LTE models of photospheres [e.g. 5]. [4pt] [1] C. Sneden, J. E. Lawler, J. J. Cowan, I. I. Ivans, and E. A. Den Hartog, Astrophys. J. Suppl. Ser. 182, 80-96 (2009). [0pt] [2] J. E. Lawler, C. Sneden, J. J. Cowan, I. I. Ivans, and E. A. Den Hartog, Astrophys. J. Suppl. Ser. 182, 51-79 (2009). [0pt] [3] J. Simmerer, C. Sneden, J. J. Cowan, J. Collier, V. M. Woolf, and J. E. Lawler, Astrophys. J. 617, 1091-1114 (2004). [0pt] [4] A. McWilliam, Ann. Rev. Astron. & Astrophys. 35, 503 (1997). [0pt] [5] M. Asplund, Ann. Rev. Astron. & Astrophys. 43, 481 (2005).

Combined Effects of Glucocorticoid and Noradrenergic Activity on Loss Aversion.

PubMed

Margittai, Zsofia; Nave, Gideon; Van Wingerden, Marijn; Schnitzler, Alfons; Schwabe, Lars; Kalenscher, Tobias

2018-01-01

Loss aversion is a well-known behavioral regularity in financial decision making, describing humans' tendency to overweigh losses compared to gains of the same amount. Recent research indicates that stress and associated hormonal changes affect loss aversion, yet the underlying neuroendocrine mechanisms are still poorly understood. Here, we investigated the causal influence of two major stress neuromodulators, cortisol and noradrenaline, on loss aversion during financial decision making. In a double-blind, placebo-controlled between-subject design, we orally administered either the α2-adrenergic antagonist yohimbine (increasing noradrenergic stimulation), hydrocortisone, both substances, or a placebo to healthy young men. We tested the treatments' influence on a financial decision-making task measuring loss aversion and risk attitude. We found that both drugs combined, relative to either drug by itself, reduced loss aversion in the absence of an effect on risk attitude or choice consistency. Our data suggest that concurrent glucocorticoid and noradrenergic activity prompts an alignment of reward- with loss-sensitivity, and thus diminishes loss aversion. Our results have implications for the understanding of the susceptibility to biases in decision making.

Posterior cingulate cortex mediates outcome-contingent allocation of behavior

PubMed Central

Hayden, Benjamin Y.; Nair, Amrita C.; McCoy, Allison N.; Platt, Michael L.

2008-01-01

SUMMARY Adaptive decision making requires selecting an action and then monitoring its consequences to improve future decisions. The neuronal mechanisms supporting action evaluation and subsequent behavioral modification, however, remain poorly understood. To investigate the contribution of posterior cingulate cortex (CGp) to these processes, we recorded activity of single neurons in monkeys performing a gambling task in which the reward outcome of each choice strongly influenced subsequent choices. We found that CGp neurons signaled reward outcomes in a nonlinear fashion, and that outcome-contingent modulations in firing rate persisted into subsequent trials. Moreover, firing rate on any one trial predicted switching to the alternative option on the next trial. Finally, microstimulation in CGp following risky choices promoted a preference reversal for the safe option on the following trial. Collectively, these results demonstrate that CGp directly contributes to the evaluative processes that support dynamic changes in decision making in volatile environments. PMID:18940585

Rational noncompliance with prescribed medical treatment.

PubMed

Stewart, Douglas O; DeMarco, Joseph P

2010-09-01

Despite the attention that patient noncompliance has received from medical researchers, patient noncompliance remains poorly understood and difficult to alter. With a better theory of patient noncompliance, both greater success in achieving compliance and greater respect for patient decision making are likely. The theory presented, which uses a microeconomic approach, bridges a gap in the extant literature that has so far ignored the contributions of this classic perspective on decision making involving the tradeoff of costs and benefits. The model also generates a surprising conclusion: that patients are typically acting rationally when they refuse to comply with certain treatments. However, compliance is predicted to rise with increased benefits and reduced costs. The prediction that noncompliance is rational is especially true in chronic conditions at the point that treatment begins to move closer to the medically ideal treatment level. Although the details of this theory have not been tested empirically, it is well supported by existing prospective and retrospective studies.

Orthopedic Implant Value Drivers: A Qualitative Survey Study of Hospital Purchasing Administrators.

PubMed

Li, Chuan Silvia; Vannabouathong, Christopher; Sprague, Sheila; Bhandari, Mohit

2015-01-01

Osteoarthritis (OA) is a chronic, degenerative disease that is highly prevalent in the population, yet the factors that affect purchasing decisions related to this condition are poorly understood. A questionnaire was developed and administered to hospital executives across North America to determine the factors that affect purchasing decisions related to OA. Thirty-four individuals participated in the survey. Clinical evidence and cost effectiveness were deemed to be the most important factors in the process of making purchasing decisions. The most important considerations for adopting new technology were whether there was sufficient evidence in the literature, followed by thoughts of key opinion leaders, and cost of intervention/device. Ongoing research is still needed, but the current study allowed us to identify some trends in the data, providing new insight on how hospital purchasing decisions are made, which could have an immediate impact on those currently involved with making these decisions.

The Intensity, Directionality, and Statistics of Underwater Noise From Melting Icebergs

NASA Astrophysics Data System (ADS)

Glowacki, Oskar; Deane, Grant B.; Moskalik, Mateusz

2018-05-01

Freshwater fluxes from melting icebergs and glaciers are important contributors to both sea level rise and anomalies of seawater salinity in polar regions. However, the hazards encountered close to icebergs and glaciers make it difficult to quantify their melt rates directly, motivating the development of cryoacoustics as a remote sensing technique. Recent studies have shown a qualitative link between ice melting and the accompanying underwater noise, but the properties of this signal remain poorly understood. Here we examine the intensity, directionality, and temporal statistics of the underwater noise radiated by melting icebergs in Hornsund Fjord, Svalbard, using a three-element acoustic array. We present the first estimate of noise energy per unit area associated with iceberg melt and demonstrate its qualitative dependence on exposure to surface current. Finally, we show that the analysis of noise directionality and statistics makes it possible to distinguish iceberg melt from the glacier terminus melt.

Poor environmental tracking can make extinction risk insensitive to the colour of environmental noise

PubMed Central

van de Pol, Martijn; Vindenes, Yngvild; Sæther, Bernt-Erik; Engen, Steinar; Ens, Bruno J.; Oosterbeek, Kees; Tinbergen, Joost M.

2011-01-01

The relative importance of environmental colour for extinction risk compared with other aspects of environmental noise (mean and interannual variability) is poorly understood. Such knowledge is currently relevant, as climate change can cause the mean, variability and temporal autocorrelation of environmental variables to change. Here, we predict that the extinction risk of a shorebird population increases with the colour of a key environmental variable: winter temperature. However, the effect is weak compared with the impact of changes in the mean and interannual variability of temperature. Extinction risk was largely insensitive to noise colour, because demographic rates are poor in tracking the colour of the environment. We show that three mechanisms—which probably act in many species—can cause poor environmental tracking: (i) demographic rates that depend nonlinearly on environmental variables filter the noise colour, (ii) demographic rates typically depend on several environmental signals that do not change colour synchronously, and (iii) demographic stochasticity whitens the colour of demographic rates at low population size. We argue that the common practice of assuming perfect environmental tracking may result in overemphasizing the importance of noise colour for extinction risk. Consequently, ignoring environmental autocorrelation in population viability analysis could be less problematic than generally thought. PMID:21561978

Chemical kinetics and modeling of planetary atmospheres

NASA Technical Reports Server (NTRS)

Yung, Yuk L.

1990-01-01

A unified overview is presented for chemical kinetics and chemical modeling in planetary atmospheres. The recent major advances in the understanding of the chemistry of the terrestrial atmosphere make the study of planets more interesting and relevant. A deeper understanding suggests that the important chemical cycles have a universal character that connects the different planets and ultimately link together the origin and evolution of the solar system. The completeness (or incompleteness) of the data base for chemical kinetics in planetary atmospheres will always be judged by comparison with that for the terrestrial atmosphere. In the latter case, the chemistry of H, O, N, and Cl species is well understood. S chemistry is poorly understood. In the atmospheres of Jovian planets and Titan, the C-H chemistry of simple species (containing 2 or less C atoms) is fairly well understood. The chemistry of higher hydrocarbons and the C-N, P-N chemistry is much less understood. In the atmosphere of Venus, the dominant chemistry is that of chlorine and sulfur, and very little is known about C1-S coupled chemistry. A new frontier for chemical kinetics both in the Earth and planetary atmospheres is the study of heterogeneous reactions. The formation of the ozone hole on Earth, the ubiquitous photochemical haze on Venus and in the Jovian planets and Titan all testify to the importance of heterogeneous reactions. It remains a challenge to connect the gas phase chemistry to the production of aerosols.

Zebrafish models in neuropsychopharmacology and CNS drug discovery.

PubMed

Khan, Kanza M; Collier, Adam D; Meshalkina, Darya A; Kysil, Elana V; Khatsko, Sergey L; Kolesnikova, Tatyana; Morzherin, Yury Yu; Warnick, Jason E; Kalueff, Allan V; Echevarria, David J

2017-07-01

Despite the high prevalence of neuropsychiatric disorders, their aetiology and molecular mechanisms remain poorly understood. The zebrafish (Danio rerio) is increasingly utilized as a powerful animal model in neuropharmacology research and in vivo drug screening. Collectively, this makes zebrafish a useful tool for drug discovery and the identification of disordered molecular pathways. Here, we discuss zebrafish models of selected human neuropsychiatric disorders and drug-induced phenotypes. As well as covering a broad range of brain disorders (from anxiety and psychoses to neurodegeneration), we also summarize recent developments in zebrafish genetics and small molecule screening, which markedly enhance the disease modelling and the discovery of novel drug targets. © 2017 The British Pharmacological Society.

Single-Dose Testosterone Administration Impairs Cognitive Reflection in Men.

PubMed

Nave, Gideon; Nadler, Amos; Zava, David; Camerer, Colin

2017-10-01

In nonhumans, the sex steroid testosterone regulates reproductive behaviors such as fighting between males and mating. In humans, correlational studies have linked testosterone with aggression and disorders associated with poor impulse control, but the neuropsychological processes at work are poorly understood. Building on a dual-process framework, we propose a mechanism underlying testosterone's behavioral effects in humans: reduction in cognitive reflection. In the largest study of behavioral effects of testosterone administration to date, 243 men received either testosterone or placebo and took the Cognitive Reflection Test (CRT), which estimates the capacity to override incorrect intuitive judgments with deliberate correct responses. Testosterone administration reduced CRT scores. The effect remained after we controlled for age, mood, math skills, whether participants believed they had received the placebo or testosterone, and the effects of 14 additional hormones, and it held for each of the CRT questions in isolation. Our findings suggest a mechanism underlying testosterone's diverse effects on humans' judgments and decision making and provide novel, clear, and testable predictions.

Subsurface metabolic potential on the Costa Rican Margin

NASA Astrophysics Data System (ADS)

Biddle, J.; Leon, Z. R.; Martino, A. J.; Bousses, K.; House, C. H.

2017-12-01

The distribution of archaea and bacteria and their associated metabolic abilities in the deep subseafloor are poorly understood. In order to explore this, we focused on samples from the Costa Rica margin IODP Expedition 334. The microbial community was analyzed via metagenomics in two different sites at multiple depths. At Site 1378, samples are from 2 meters below the sea floor (mbsf), 33 mbsf and 93 mbsf, and at Site 1379 from 22 mbsf to 45 mbsf. Whole community analysis of conserved gene markers in the metagenome show that the microbial community varies with depth, and drastically differs between the two geographically close sites. Thirty-two genomes were recovered from the metagenomic data with more than 30% completion. Archaea make 49% of all genomes recovered and over 90% of these recovered genomes belong to recently discovered and poorly characterized groups of Archaea. This study explored the relative dynamics of microbial communities in the deep biosphere and presents the metabolic potential of distinct subsurface biosphere archaeal groups.

Policy and technology for clean air - the federal government must make a strong commitment to applying state-of-art technologies to the challenge of clearing the air.

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

Streets, D. G.; Decision and Information Sciences

1999-01-01

The federal government must make a strong commitment to applying state-of-the-art technologies to the challenge of clearing the air. Environmental hazards in one form or another surround us. While essentially all of them threaten our health and well-being, our ability to respond to them varies. We can move away from toxic waste sites; we can sanitize our water before we drink it; we can shield ourselves from harmful radiation. But we cannot escape the air. As a fluid medium, the air accepts all the contaminants we inject into it, mixes them together, and delivers the resulting concoction directly into ourmore » lungs. Though our exposure to air pollutants varies by time and place, and the effect depends on our individual susceptibilities, one truth remains: if we live, we breathe. Today, in many parts of the United States and in many other countries around the world, poor air quality threatens human health and the environment. But our expectations for clean air are higher today than they have ever been, and the damage caused by poor air quality is better understood than ever.« less

What makes champions? A review of the relative contribution of genes and training to sporting success.

PubMed

Tucker, Ross; Collins, Malcolm

2012-06-01

Elite sporting performance results from the combination of innumerable factors, which interact with one another in a poorly understood but complex manner to mould a talented athlete into a champion. Within the field of sports science, elite performance is understood to be the result of both training and genetic factors. However, the extent to which champions are born or made is a question that remains one of considerable interest, since it has implications for talent identification and management, as well as for how sporting federations allocate scarce resources towards the optimisation of high-performance programmes. The present review describes the contributions made by deliberate practice and genetic factors to the attainment of a high level of sporting performance. The authors conclude that although deliberate training and other environmental factors are critical for elite performance, they cannot by themselves produce an elite athlete. Rather, individual performance thresholds are determined by our genetic make-up, and training can be defined as the process by which genetic potential is realised. Although the specific details are currently unknown, the current scientific literature clearly indicates that both nurture and nature are involved in determining elite athletic performance. In conclusion, elite sporting performance is the result of the interaction between genetic and training factors, with the result that both talent identification and management systems to facilitate optimal training are crucial to sporting success.

Lags in the response of mountain plant communities to climate change

PubMed Central

Alexander, Jake M.; Chalmandrier, Loïc; Lenoir, Jonathan; Burgess, Treena I.; Essl, Franz; Haider, Sylvia; Kueffer, Christoph; McDougall, Keith; Milbau, Ann; Nuñez, Martin A.; Pauchard, Aníbal; Rabitsch, Wolfgang; Rew, Lisa J.; Sanders, Nathan J.; Pellissier, Loïc

2018-01-01

Rapid climatic changes and increasing human influence at high elevations around the world will have profound impacts on mountain biodiversity. However, forecasts from statistical models (e.g. species distribution models) rarely consider that plant community changes could substantially lag behind climatic changes, hindering our ability to make temporally realistic projections for the coming century. Indeed, the magnitudes of lags, and the relative importance of the different factors giving rise to them, remain poorly understood. We review evidence for three types of lag: “dispersal lags” affecting plant species’ spread along elevational gradients, “establishment lags” following their arrival in recipient communities, and “extinction lags” of resident species. Variation in lags is explained by variation among species in physiological and demographic responses, by effects of altered biotic interactions, and by aspects of the physical environment. Of these, altered biotic interactions could contribute substantially to establishment and extinction lags, yet impacts of biotic interactions on range dynamics are poorly understood. We develop a mechanistic community model to illustrate how species turnover in future communities might lag behind simple expectations based on species’ range shifts with unlimited dispersal. The model shows a combined contribution of altered biotic interactions and dispersal lags to plant community turnover along an elevational gradient following climate warming. Our review and simulation support the view that accounting for disequilibrium range dynamics will be essential for realistic forecasts of patterns of biodiversity under climate change, with implications for the conservation of mountain species and the ecosystem functions they provide. PMID:29112781

Parental Decisions regarding pre-hospital therapy and costing of the Emergency Department Visit.

PubMed

McGovern, M; Kernan, R; O'Neill, M B

2017-02-10

Paediatric patients represent a large percentage of Emergency Department (ED) visits and there is often a perception that the acuity of these presentations is low. The decision-making process that results in parents attending the ED is poorly understood. We designed a cross-sectional cohort study to explore the reasons for attendance, the treatment initiated at home and to assess parental perception of the economic cost of attendance. Data was collected on 200 patients using a survey administered to parents in ED with a follow-up phone call 4-6 weeks later. Our results suggest that attendances are often prompted by parental anxiety rather than clinical deterioration and that prior ED usage is common among those presenting for assessment. Many parents had attempted community therapy with 128/200 patients (64%) having been referred by a healthcare professional and medical therapy at home having been employed by 114/200 (57%) parents before attendance. Parental knowledge of the safety of over-the-counter medications was variable the economic cost of an ED visit was poorly understood by participants. The results of our study suggest that parental desire for control over worrisome symptoms drives much of their management strategy prior to hospital attendance. Strategies in the ED may need to focus more on managing parental expectations than on managing the illness itself and management strategies employed should focus not only on medical therapy of the child's illness but on educating and empowering the parent.

Risky decision making in adults with ADHD.

PubMed

Matthies, S; Philipsen, A; Svaldi, J

2012-09-01

Risky decision making and disadvantageous choices constitute core characteristics of patients with attention-deficit/hyperactivity disorder (ADHD). Consequences include negative psychosocial and health-related outcomes. However, risky decision making and its interrelations with emotional states in ADHD are poorly understood. Therefore, the authors investigated risky decision making without and after boredom induction in adults with and without ADHD. In study 1, ADHD patients (n = 15) and age/education matched controls (CG; n = 16) were compared on the Game of Dice Task (GDT), an established task measuring decision making in unambiguous situations. In study 2, ADHD patients (n = 14) and CG (n = 13) underwent boredom induction prior to the GDT. In study 1, ADHD patients selected the disadvantageous alternatives significantly more often than CG. In study 2, no significant group differences were found due to an increase in risky decision making in CG following the boredom induction. Even if severity of depression did not affect our results, it may be necessary to compare GDT responses in ADHD patients with and without current depression. Risk as a motor of disadvantageous decision making needs to be taken into account in therapeutic contexts as a maintenance factor of dysfunctional behaviour. The findings of study 2 are in line with postulated alterations of emotional state adjustment in ADHD. The link between decisions making and emotional regulation in ADHD needs further attention in research. Copyright © 2012 Elsevier Ltd. All rights reserved.

Nonarteritic anterior ischemic optic neuropathy (NAION) and its experimental models

PubMed Central

Bernstein, Steven L.; Johnson, Mary A.; Miller, Neil R.

2011-01-01

Anterior ischemic optic neuropathy (AION) can be divided into nonarteritic (NAION) and arteritic (AAION) forms. NAION makes up ~85% of all cases of AION, and until recently was poorly understood. There is no treatment for NAION, and its initiating causes are poorly understood, in part because NAION is not lethal, making it difficult to obtain fresh, newly affected tissue for study. In-vivo electrophysiology and post-mortem studies reveal specific responses that are associated with NAION. New models of NAION have been developed which enable insights into the pathophysiological events surrounding this disease. These models include both rodent and primate species, and the power of a `vertically integrated' multi-species approach can help in understanding the common cellular mechanisms and physiological responses to clinical NAION, and to identify potential approaches to treatment. The models utilize laser light to activate intravascular photoactive dye to induce capillary vascular thrombosis, while sparing the larger vessels. The observable optic nerve changes associated with rodent models of AION (rAION) and primate NAION (pNAION) are indistinguishable from that seen in clinical disease, including sectoral axonal involvement, and in-vivo electrophysiological data from these models are consistent with clinical data. Early post-infarct events reveal an unexpected inflammatory response, and changes in intraretinal gene expression for both stress response, while sparing outer retinal function, which occurs in AAION models. Histologically, the NAION models reveal an isolated loss of retinal ganglion cells by apoptosis. There are changes detectable by immunohistochemistry suggesting that other retinal cells mount a brisk response to retinal ganglion cell distress without themselves dying. The optic nerve ultimately shows axonal loss and scarring. Inflammation is a prominent early histological feature. This suggests that clinically, specific modulation of inflammation may be a useful approach to NAION treatment early in the course of the disease. PMID:21376134

3D animation model with augmented reality for natural science learning in elementary school

NASA Astrophysics Data System (ADS)

Hendajani, F.; Hakim, A.; Lusita, M. D.; Saputra, G. E.; Ramadhana, A. P.

2018-05-01

Many opinions from primary school students' on Natural Science are a difficult lesson. Many subjects are not easily understood by students, especially on materials that teach some theories about natural processes. Such as rain process, condensation and many other processes. The difficulty that students experience in understanding it is that students cannot imagine the things that have been taught in the material. Although there is material to practice some theories but is actually quite limited. There is also a video or simulation material in the form of 2D animated images. Understanding concepts in natural science lessons are also poorly understood by students. Natural Science learning media uses 3-dimensional animation models (3D) with augmented reality technology, which offers some visualization of science lessons. This application was created to visualize a process in Natural Science subject matter. The hope of making this application is to improve student's concept. This app is made to run on a personal computer that comes with a webcam with augmented reality. The app will display a 3D animation if the camera can recognize the marker.

Seasonality in communication and collective decision-making in ants.

PubMed

Stroeymeyt, N; Jordan, C; Mayer, G; Hovsepian, S; Giurfa, M; Franks, N R

2014-04-07

The ability of animals to adjust their behaviour according to seasonal changes in their ecology is crucial for their fitness. Eusocial insects display strong collective behavioural seasonality, yet the mechanisms underlying such changes are poorly understood. We show that nest preference by emigrating Temnothorax albipennis ant colonies is influenced by a season-specific modulatory pheromone that may help tune decision-making according to seasonal constraints. The modulatory pheromone triggers aversion towards low-quality nests and enhances colony cohesion in summer and autumn, but not after overwintering-in agreement with reports that field colonies split in spring and reunite in summer. Interestingly, we show that the pheromone acts by downgrading the perceived value of marked nests by informed and naive individuals. This contrasts with theories of collective intelligence, stating that accurate collective decision-making requires independent evaluation of options by individuals. The violation of independence highlighted here was accordingly shown to increase error rate during emigrations. However, this is counterbalanced by enhanced cohesion and the transmission of valuable information through the colony. Our results support recent claims that optimal decisions are not necessarily those that maximize accuracy. Other criteria-such as cohesion or reward rate-may be more relevant in animal decision-making.

Serotonin shapes risky decision making in monkeys.

PubMed

Long, Arwen B; Kuhn, Cynthia M; Platt, Michael L

2009-12-01

Some people love taking risks, while others avoid gambles at all costs. The neural mechanisms underlying individual variation in preference for risky or certain outcomes, however, remain poorly understood. Although behavioral pathologies associated with compulsive gambling, addiction and other psychiatric disorders implicate deficient serotonin signaling in pathological decision making, there is little experimental evidence demonstrating a link between serotonin and risky decision making, in part due to the lack of a good animal model. We used dietary rapid tryptophan depletion (RTD) to acutely lower brain serotonin in three macaques performing a simple gambling task for fluid rewards. To confirm the efficacy of RTD experiments, we measured total plasma tryptophan using high-performance liquid chromatography (HPLC) with electrochemical detection. Reducing brain serotonin synthesis decreased preference for the safe option in a gambling task. Moreover, lowering brain serotonin function significantly decreased the premium required for monkeys to switch their preference to the risky option, suggesting that diminished serotonin signaling enhances the relative subjective value of the risky option. These results implicate serotonin in risk-sensitive decision making and, further, suggest pharmacological therapies for treating pathological risk preferences in disorders such as problem gambling and addiction.

Decision-making for risky gains and losses among college students with Internet gaming disorder.

PubMed

Yao, Yuan-Wei; Chen, Pin-Ru; Li, Song; Wang, Ling-Jiao; Zhang, Jin-Tao; Yip, Sarah W; Chen, Gang; Deng, Lin-Yuan; Liu, Qin-Xue; Fang, Xiao-Yi

2015-01-01

Individuals with Internet gaming disorder (IGD) tend to exhibit disadvantageous risky decision-making not only in their real life but also in laboratory tasks. Decision-making is a complex multifaceted function and different cognitive processes are involved in decision-making for gains and losses. However, the relationship between impaired decision-making and gain versus loss processing in the context of IGD is poorly understood. The main aim of the present study was to separately evaluate decision-making for risky gains and losses among college students with IGD using the Cups task. Additionally, we further examined the effects of outcome magnitude and probability level on decision-making related to risky gains and losses respectively. Sixty college students with IGD and 42 matched healthy controls (HCs) participated. Results indicated that IGD subjects exhibited generally greater risk taking tendencies than HCs. In comparison to HCs, IGD subjects made more disadvantageous risky choices in the loss domain (but not in the gain domain). Follow-up analyses indicated that the impairment was associated to insensitivity to changes in outcome magnitude and probability level for risky losses among IGD subjects. In addition, higher Internet addiction severity scores were associated with percentage of disadvantageous risky options in the loss domain. These findings emphasize the effect of insensitivity to losses on disadvantageous decisions under risk in the context of IGD, which has implications for future intervention studies.

The impacts of livestock diseases and their control on growth and development processes that are pro-poor

PubMed Central

Perry, Brian; Grace, Delia

2009-01-01

Poverty is now at the heart of development discourse; we discuss how it is measured and understood. We next consider the negative and positive impacts of livestock on pro-poor development. Taking a value-chain approach that includes keepers, users and eaters of livestock, we identify diseases that are road blocks on the ‘three livestock pathways out of poverty’. We discuss livestock impacts on poverty reduction and review attempts to prioritize the livestock diseases relevant to the poor. We make suggestions for metrics that better measure disease impact and show the benefits of more rigorous evaluation before reviewing recent attempts to measure the importance of disease to the poor. High impact of a disease does not guarantee high benefits from its control; other factors must be taken into consideration, including technical feasibility and political desirability. We conclude by considering how we might better understand and exploit the roles of livestock and improved animal health by posing three speculative questions on the impact of livestock diseases and their control on global poverty: how can understanding livestock and poverty links help disease control?; if global poverty reduction was the aim of livestock disease control, how would it differ from the current model?; and how much of the impact of livestock disease on poverty is due to disease control policy rather than disease itself? PMID:19687035

The role of the family in HIV status disclosure among women in Vietnam: Familial dependence and independence.

PubMed

Dinh, H T; White, J L; Hipwell, M; Nguyen, C T K; Pharris, A

2018-04-01

Insights into disclosure by people living with HIV and AIDS (PLWHA) can inform strategies for treatment and support, yet Vietnamese women's self-disclosure patterns are poorly understood. We conducted interviews with 12 HIV-positive women, identifying three principal factors influencing disclosure to family members: patrilocal residence, desire to protect own family, and the need for financial support. Women's decision-making about disclosure was significantly affected by dependence on or independence of parents-in-law and their own parents. We believe that our findings reveal the complex interplay of stigma and disclosure within Vietnamese families, highlighting the need for specific social measures that promote self-disclosure combined with family support for female PLWHA.

Human casualties in earthquakes: Modelling and mitigation

USGS Publications Warehouse

Spence, R.J.S.; So, E.K.M.

2011-01-01

Earthquake risk modelling is needed for the planning of post-event emergency operations, for the development of insurance schemes, for the planning of mitigation measures in the existing building stock, and for the development of appropriate building regulations; in all of these applications estimates of casualty numbers are essential. But there are many questions about casualty estimation which are still poorly understood. These questions relate to the causes and nature of the injuries and deaths, and the extent to which they can be quantified. This paper looks at the evidence on these questions from recent studies. It then reviews casualty estimation models available, and finally compares the performance of some casualty models in making rapid post-event casualty estimates in recent earthquakes.

Mutations that alter the equilibrium between open and closed conformations of Escherichia coli maltose-binding protein impede its ability to enhance the solubility of passenger proteins

PubMed Central

Nallamsetty, Sreedevi; Waugh, David S.

2007-01-01

Certain highly soluble proteins, such as Escherichia coli maltose-binding protein (MBP), have the ability to enhance the solubility of their fusion partners, making them attractive vehicles for the production of recombinant proteins, yet the mechanism of solubility enhancement remains poorly understood. Here, we report that the solubility-enhancing properties of MBP are dramatically affected by amino acid substitutions that alter the equilibrium between its “open” and “closed” conformations. Our findings indicate that the solubility-enhancing activity of MBP is mediated by its open conformation and point to a likely role for the ligand-binding cleft in the mechanism of solubility enhancement. PMID:17964542

The Role of Institutional Factors on On-Campus Reported Rape Prevalence.

PubMed

Stotzer, Rebecca L; MacCartney, Danielle

2016-10-01

Sexual assault is a serious concern on college and university campuses across the United States. However, the institutional factors that may make campuses more or less prone to rape are poorly understood. This study utilizes routine activities theory (RAT) to examine campus-related factors across 524 four-year campuses in the United States to determine what features of a campus community are most closely associated with increased reports of sexual assault. Results suggest that the type of athletic program, the number of students who live on campus, and the institution's alcohol policy were all found to be related to reported sexual assaults. Implications for understanding campus communities and prevention of sexual assaults are discussed. © The Author(s) 2015.

Language, embodiment, and the cognitive niche.

PubMed

Clark, Andy

2006-08-01

Embodied agents use bodily actions and environmental interventions to make the world a better place to think in. Where does language fit into this emerging picture of the embodied, ecologically efficient agent? One useful way to approach this question is to consider language itself as a cognition-enhancing animal-built structure. To take this perspective is to view language as a kind of self-constructed cognitive niche: a persisting but never stationary material scaffolding whose crucial role in promoting thought and reason remains surprisingly poorly understood. It is the very materiality of this linguistic scaffolding, I suggest, that gives it some key benefits. By materializing thought in words, we create structures that are themselves proper objects of perception, manipulation, and (further) thought.

Engineering education as a complex system

NASA Astrophysics Data System (ADS)

Gattie, David K.; Kellam, Nadia N.; Schramski, John R.; Walther, Joachim

2011-12-01

This paper presents a theoretical basis for cultivating engineering education as a complex system that will prepare students to think critically and make decisions with regard to poorly understood, ill-structured issues. Integral to this theoretical basis is a solution space construct developed and presented as a benchmark for evaluating problem-solving orientations that emerge within students' thinking as they progress through an engineering curriculum. It is proposed that the traditional engineering education model, while analytically rigorous, is characterised by properties that, although necessary, are insufficient for preparing students to address complex issues of the twenty-first century. A Synthesis and Design Studio model for engineering education is proposed, which maintains the necessary rigor of analysis within a uniquely complex yet sufficiently structured learning environment.

A Qualitative Systematic Review of the Bereavement Process Following Suicide.

PubMed

Shields, Chris; Kavanagh, Michele; Russo, Kate

2017-03-01

Despite the fact that a large number of people are bereaved by suicide each year, the experiences of those bereaved by suicide are poorly understood. It has been suggested that a contributing factor in relation to this lack of understanding has been the use of quantitative methods, which may not be sensitive to the bereavement process and its thematic content. Therefore, the current article outlines a systematic review of 11 qualitative studies that address issues related to the bereavement process following suicide. The results indicate that those bereaved by suicide encounter a range of difficult feelings following suicide including blame, guilt, and emptiness and that these feelings are affected by participants' ability to make meaning of the event. The meaning-making process is a complex one that occurs within a difficult social context in which both those bereaved by suicide and members of the wider community struggle to interact with each other in a beneficial way. Clinical implications of these findings are discussed.

Mining Social Entrepreneurship Strategies Using Topic Modeling

PubMed Central

2016-01-01

Despite the burgeoning research on social entrepreneurship (SE), SE strategies remain poorly understood. Drawing on extant research on the social activism and social change, empowerment and SE models, we explore, classify and validate the strategies used by 2,334 social entrepreneurs affiliated with the world’s largest SE support organization, Ashoka. The results of the topic modeling of the social entrepreneurs’ strategy profiles reveal that they employed a total of 39 change-making strategies that vary across resources (material versus symbolic strategies), specificity (general versus specific strategies), and mode of participation (mass versus elite participation strategies); they also vary across fields of practice and time. Finally, we identify six meta-SE strategies―a reduction from the 39 strategies―and identify four new meta-SE strategies (i.e., system reform, physical capital development, evidence-based practices, and prototyping) that have been overlooked in prior SE research. Our findings extend and deepen the research into SE strategies and offer a comprehensive model of SE strategies that advances theory, practice and policy making. PMID:26998970

Food that makes you different: the stigma experienced by adolescents with celiac disease.

PubMed

Olsson, Cecilia; Lyon, Phil; Hörnell, Agneta; Ivarsson, Anneli; Sydner, Ylva Mattsson

2009-07-01

For adolescents with celiac disease (CD), a gluten-free diet (GFD) is crucial for health, but compliance is problematic and noncompliance is common even among those aware of the risks. To better understand their lives with the disease, Swedish CD adolescents were invited to take part in focus group discussions. Data were analyzed for recurrent stigma-related themes across the groups. Adolescents described an awareness of being different from others that was produced by meal appearance and the poor availability of gluten-free food. The GFD often required discussions and special requests, so eating in public had the effect of making an invisible condition visible, and thereby creating a context for felt or enacted stigma. Maintaining invisibility avoided negative consequences of stigma, and other strategies were used to reduce the costs of visibility. The results of the study show that the GFD can produce stigma experiences in adolescence, and that dietary compliance (or lack thereof) can be understood in terms of dealing with GFD concealment and disclosure.

Evolution of plant–pollinator mutualisms in response to climate change

PubMed Central

Gilman, R Tucker; Fabina, Nicholas S; Abbott, Karen C; Rafferty, Nicole E

2012-01-01

Climate change has the potential to desynchronize the phenologies of interdependent species, with potentially catastrophic effects on mutualist populations. Phenologies can evolve, but the role of evolution in the response of mutualisms to climate change is poorly understood. We developed a model that explicitly considers both the evolution and the population dynamics of a plant–pollinator mutualism under climate change. How the populations evolve, and thus whether the populations and the mutualism persist, depends not only on the rate of climate change but also on the densities and phenologies of other species in the community. Abundant alternative mutualist partners with broad temporal distributions can make a mutualism more robust to climate change, while abundant alternative partners with narrow temporal distributions can make a mutualism less robust. How community composition and the rate of climate change affect the persistence of mutualisms is mediated by two-species Allee thresholds. Understanding these thresholds will help researchers to identify those mutualisms at highest risk owing to climate change. PMID:25568025

Mining Social Entrepreneurship Strategies Using Topic Modeling.

PubMed

Chandra, Yanto; Jiang, Li Crystal; Wang, Cheng-Jun

2016-01-01

Despite the burgeoning research on social entrepreneurship (SE), SE strategies remain poorly understood. Drawing on extant research on the social activism and social change, empowerment and SE models, we explore, classify and validate the strategies used by 2,334 social entrepreneurs affiliated with the world's largest SE support organization, Ashoka. The results of the topic modeling of the social entrepreneurs' strategy profiles reveal that they employed a total of 39 change-making strategies that vary across resources (material versus symbolic strategies), specificity (general versus specific strategies), and mode of participation (mass versus elite participation strategies); they also vary across fields of practice and time. Finally, we identify six meta-SE strategies-a reduction from the 39 strategies-and identify four new meta-SE strategies (i.e., system reform, physical capital development, evidence-based practices, and prototyping) that have been overlooked in prior SE research. Our findings extend and deepen the research into SE strategies and offer a comprehensive model of SE strategies that advances theory, practice and policy making.

The meaning of the virtual Midas touch: an ERP study in economic decision making.

PubMed

Spapé, Michiel M; Hoggan, Eve E; Jacucci, Giulio; Ravaja, Niklas

2015-03-01

The Midas touch refers to the altruistic effects of a brief touch. Though these effects have often been replicated, they remain poorly understood. We investigate the psychophysiology of the effect using remotely transmitted, precisely timed, tactile messages in an economic decision-making game called Ultimatum. Participants were more likely to accept offers after receiving a remotely transmitted touch. Furthermore, we found distinct effects of touch on event-related potentials evoked by (a) feedback regarding accepted and rejected offers, (b) decision cues related to proposals, and (c) the haptic and auditory cues themselves. In each case, a late positive effect of touch was observed and related to the P3. Given the role of the P3 in memory-related functions, the results indicate an indirect relationship between touch and generosity that relies on memory. This hypothesis was further tested and confirmed in the positive effects of touch on later proposals. © 2014 Society for Psychophysiological Research.

NASA Aims to Create First-Ever Space-Based Sodium Lidar to Study Poorly Understood Mesosphere

NASA Image and Video Library

2017-12-08

Caption: Mike Krainak (left) and Diego Janches recently won NASA follow-on funding to advance a spaceborne sodium lidar needed to probe Earth’s poorly understood mesosphere. Credits: NASA/W. Hrybyk More: A team of NASA scientists and engineers now believes it can leverage recent advances in a greenhouse-detecting instrument to build the world’s first space-based sodium lidar to study Earth’s poorly understood mesosphere. Scientist Diego Janches and laser experts Mike Krainak and Tony Yu, all of whom work at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, are leading a research-and-development effort to further advance the sodium lidar, which the group plans to deploy on the International Space Station if it succeeds in proving its flightworthiness. Read more: go.nasa.gov/2rcGpSM NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Auditory Processing Disorders: Acquisition and Treatment

ERIC Educational Resources Information Center

Moore, David R.

2007-01-01

Auditory processing disorder (APD) describes a mixed and poorly understood listening problem characterised by poor speech perception, especially in challenging environments. APD may include an inherited component, and this may be major, but studies reviewed here of children with long-term otitis media with effusion (OME) provide strong evidence…

Neuropsychological Markers of Suicidal Risk in the Context of Medical Rehabilitation.

PubMed

Pustilnik, Alexandra; Elkana, Odelia; Vatine, Jean-Jacques; Franko, Motty; Hamdan, Sami

2017-01-01

While great strides have been made to advance the understanding of the neurobiology of suicidal behavior (SB), the neural and neuropsychological mechanisms associated with SB are not well understood. The purpose of the current study is to identify neurocognitive markers of SB in the context of medical rehabilitation. The performances of 39 patients at a medical rehabilitation center, aged 21-78, were examined on a series of neurocognitive executive tasks-decision-making (Iowa Gambling Task - IGT), mental flexibility (WCST), response inhibition (SST) and working memory (digit span). Self-report questionnaires were administered, for Suicidal behaviors, depression, Anxiety, and PTSD as well as perceived social support. Suicidal participants performed more poorly on the IGT. A mediation analysis presented a significant direct effect of decision making on suicidal risk (p < 0.14) as well as significant indirect effect of decision making on suicidal risk that was mediated by the depressive symptoms (95% BCa CI [-0.15, -0.018]) with a medium effect size (κ 2  = 0.20, 95% BCa CI [0.067, 0.381]). Despite the complexity of relationship between decision-making and suicidal risk, these results suggest that clinicians should routinely assess decision-making abilities in adults at risk for suicide due to the fact that impaired decision-making may increase suicidal risk above and beyond that conferred by depression.

Developmental changes and individual differences in risk and perspective taking in adolescence.

PubMed

Crone, Eveline A; Bullens, L; van der Plas, E A A; Kijkuit, E J; Zelazo, P D

2008-01-01

Despite the assumed prevalence of risk-taking behavior in adolescence, the laboratory evidence of risk taking remains scarce, and the individual variation poorly understood. Drawing from neuroscience studies, we tested whether risk and reward orientation are influenced by the perspective that adolescents take when making risky decisions. Perspective taking was manipulated by cuing participants prior to each choice whether the decision was made for "self," or from the perspective of an "other" (the experimenter in Experiment 1; a hypothetical peer in Experiment 2). In Experiment 1, we show a developmental decrease in risk-taking behavior across different stages of adolescence. In addition, all age groups made fewer risky choices for the experimenter, but the difference between self and other was larger in early adolescence. In Experiment 2, we show that high sensation-seeking (SS) adolescents make more risky choices than low SS adolescents, but both groups make a similar differentiation for other individuals (low risk-taking or high risk-taking peers). Together, the results show that younger adolescents and high SS adolescents make more risky choices for themselves, but can appreciate that others may make fewer risky choices. The developmental change toward more rational decisions versus emotional, impulsive decisions may reflect, in part, more efficient integration of others' perspectives into one's decision making. These developmental results are discussed regarding brain systems important for risk taking and perspective taking.

Decision making by patients with breast cancer: the role of information in treatment selection.

PubMed

Hughes, K K

1993-05-01

In recent years, patients have become more involved in the clinical decision-making process, yet the nature of this process, including the role of information, is poorly understood. The purpose of this exploratory study was to examine the relationship between information about breast cancer treatment alternatives and patients' choices of treatments. The target population was all patients with breast cancer in the process of deciding between breast conservation (lumpectomy plus irradiation) and more traditional management (modified radical mastectomy, with or without reconstruction). A convenience sample of 71 female patients with stage I or II breast cancer was drawn from a breast clinic affiliated with a 1,000-bed tertiary medical center. The amount of information provided to each subject and the nature of its presentation were recorded using an observer checklist. Recall of information and final treatment selection were ascertained during telephone interviews conducted six to eight weeks after surgery. The results indicate that subjects' choice of treatment was unrelated to the amount of information they received during the clinic visit. Manner of presentation also did not influence treatment selection. However, treatment selection was related to the amount of information subjects received prior to their clinic visit (p < 0.01). The results also indicate that patients' recall of information about treatments and associated risks is exceedingly poor. Clinical and legal implications are discussed and recommendations for further research are offered in this article.

Lags in the response of mountain plant communities to climate change.

PubMed

Alexander, Jake M; Chalmandrier, Loïc; Lenoir, Jonathan; Burgess, Treena I; Essl, Franz; Haider, Sylvia; Kueffer, Christoph; McDougall, Keith; Milbau, Ann; Nuñez, Martin A; Pauchard, Aníbal; Rabitsch, Wolfgang; Rew, Lisa J; Sanders, Nathan J; Pellissier, Loïc

2018-02-01

Rapid climatic changes and increasing human influence at high elevations around the world will have profound impacts on mountain biodiversity. However, forecasts from statistical models (e.g. species distribution models) rarely consider that plant community changes could substantially lag behind climatic changes, hindering our ability to make temporally realistic projections for the coming century. Indeed, the magnitudes of lags, and the relative importance of the different factors giving rise to them, remain poorly understood. We review evidence for three types of lag: "dispersal lags" affecting plant species' spread along elevational gradients, "establishment lags" following their arrival in recipient communities, and "extinction lags" of resident species. Variation in lags is explained by variation among species in physiological and demographic responses, by effects of altered biotic interactions, and by aspects of the physical environment. Of these, altered biotic interactions could contribute substantially to establishment and extinction lags, yet impacts of biotic interactions on range dynamics are poorly understood. We develop a mechanistic community model to illustrate how species turnover in future communities might lag behind simple expectations based on species' range shifts with unlimited dispersal. The model shows a combined contribution of altered biotic interactions and dispersal lags to plant community turnover along an elevational gradient following climate warming. Our review and simulation support the view that accounting for disequilibrium range dynamics will be essential for realistic forecasts of patterns of biodiversity under climate change, with implications for the conservation of mountain species and the ecosystem functions they provide. © 2017 John Wiley & Sons Ltd.

Laser Shock Peening on Zr-based Bulk Metallic Glass and Its Effect on Plasticity: Experiment and Modeling

NASA Astrophysics Data System (ADS)

Cao, Yunfeng; Xie, Xie; Antonaglia, James; Winiarski, Bartlomiej; Wang, Gongyao; Shin, Yung C.; Withers, Philip J.; Dahmen, Karin A.; Liaw, Peter K.

2015-05-01

The Zr-based bulk metallic glasses (BMGs) are a new family of attractive materials with good glass-forming ability and excellent mechanical properties, such as high strength and good wear resistance, which make them candidates for structural and biomedical materials. Although the mechanical behavior of BMGs has been widely investigated, their deformation mechanisms are still poorly understood. In particular, their poor ductility significantly impedes their industrial application. In the present work, we show that the ductility of Zr-based BMGs with nearly zero plasticity is improved by a laser shock peening technique. Moreover, we map the distribution of laser-induced residual stresses via the micro-slot cutting method, and then predict them using a three-dimensional finite-element method coupled with a confined plasma model. Reasonable agreement is achieved between the experimental and modeling results. The analyses of serrated flows reveal plentiful and useful information of the underlying deformation process. Our work provides an easy and effective way to extend the ductility of intrinsically-brittle BMGs, opening up wider applications of these materials.

Epidemiology, biology and treatment of sarcomatoid RCC: current state of the art.

PubMed

Lebacle, Cedric; Pooli, Aydin; Bessede, Thomas; Irani, Jacques; Pantuck, Allan J; Drakaki, Alexandra

2018-06-01

Long recognized to confer an extremely poor prognosis, sarcomatoid dedifferentiation of renal cell carcinoma (sRCC) is a tumor phenotype that is finally beginning to be better understood on the molecular and genetic levels. With an overall incidence that ranges from 1 to 32% depending on associated RCC subtype, the survival of sarcomatoid RCC patients rarely exceeds 2 years. The main reasons for its poor outcome include its aggressive biology, its tendency to present at an advanced or metastatic stage at the time of diagnosis, its high rate of tumor recurrence after nephrectomy, and its limited response to systemic therapies. Molecular pathology studies suggest that sarcomatoid dedifferentiation originates from a focal epithelial-mesenchymal transition (EMT) arising in the carcinomatous component of the tumor. It is hoped that the growing understanding of the molecular biology of sRCC will soon make it possible to adapt treatments based on the identification of actionable tumor alterations. The deliberate inclusion of these patients in the multicenter clinical trials of immune, targeted and combination therapies is a necessary next step in pioneering future treatment strategies.

Africa: continent of genome contrasts with implications for biomedical research and health.

PubMed

Ramsay, Michèle

2012-08-31

The genomic architecture of African populations is poorly understood and there is considerable variation between ethno-linguistic groups. Genome-wide approaches have been extensively applied to search for genetic associations to complex traits in Europeans, but rarely in Africans. This is largely attributed to lower levels of funding, poor infrastructure and public health systems, and to the small pool of trained scientists. High levels of genetic variation and underlying population structure in Africans present significant challenges, but lower levels of linkage disequilibrium provide an opportunity for more effective localisation of causal variants. High throughput technologies, including dense genotyping arrays, genome sequencing and epigenome studies, together with plummeting costs, are making research more affordable, even for African scientists. Understanding the interactions between genome structure and environmental influences is essential to interpreting their contributions to the increase in infectious diseases and non-communicable diseases, exacerbated by adverse environments and lifestyle choices. The unique genome dynamics in African populations have an important role to play in understanding human health and susceptibility to disease. Copyright © 2012. Published by Elsevier B.V.

Laser shock peening on Zr-based bulk metallic glass and its effect on plasticity: Experiment and modeling

DOE PAGES

Cao, Yunfeng; Xie, Xie; Antonaglia, James; ...

2015-05-20

The Zr-based bulk metallic glasses (BMGs) are a new family of attractive materials with good glass-forming ability and excellent mechanical properties, such as high strength and excellent wear resistance, which make them candidates for structural and biomedical materials. Although the mechanical behavior of BMGs has been widely investigated, their deformation mechanisms are still poorly understood. In particular, their poor ductility significantly impedes their industrial application. In the present work, we show that the ductility of Zr-based BMGs with nearly zero plasticity is improved by a laser shock peening technique. Moreover, we map the distribution of laser-induced residual stresses via themore » micro-slot cutting method, and then predict them using a three dimensional finite-element method coupled with a confined plasma model. Reasonable agreement is achieved between the experimental and modeling results. The analysis of serrated flow reveals plentiful and useful information of the underlying deformation process. As a result, our work provides an easy and effective way to extend the ductility of intrinsically-brittle BMGs, opening up wider applications of these materials.« less

A model for genetic and epigenetic regulatory networks identifies rare pathways for transcription factor induced pluripotency

NASA Astrophysics Data System (ADS)

Artyomov, Maxim; Meissner, Alex; Chakraborty, Arup

2010-03-01

Most cells in an organism have the same DNA. Yet, different cell types express different proteins and carry out different functions. This is because of epigenetic differences; i.e., DNA in different cell types is packaged distinctly, making it hard to express certain genes while facilitating the expression of others. During development, upon receipt of appropriate cues, pluripotent embryonic stem cells differentiate into diverse cell types that make up the organism (e.g., a human). There has long been an effort to make this process go backward -- i.e., reprogram a differentiated cell (e.g., a skin cell) to pluripotent status. Recently, this has been achieved by transfecting certain transcription factors into differentiated cells. This method does not use embryonic material and promises the development of patient-specific regenerative medicine, but it is inefficient. The mechanisms that make reprogramming rare, or even possible, are poorly understood. We have developed the first computational model of transcription factor-induced reprogramming. Results obtained from the model are consistent with diverse observations, and identify the rare pathways that allow reprogramming to occur. If validated, our model could be further developed to design optimal strategies for reprogramming and shed light on basic questions in biology.

Do people really know what makes a family history of cancer?

PubMed

Lim, Jennifer N W; Hewison, Jenny

2014-12-01

Family history is often referred to as a family tree in casual everyday conservations, but it carries a different connotation in medicine. This study is the first to investigate people's understanding of 'family medical history' and the concept of 'family' in the context of inherited cancer. Three hundred and nine staff at the Faculty of Medicine and Health, University of Leeds completed an online web survey. Not all respondents understood or knew what makes a family history of cancer. Only 54% knew exactly the type of information required to make a family history. Apart from blood relatives, adopted and step-siblings, step parents, in-laws, spouses, friends and colleagues were also named as 'family' for family history taking. Personal experience of living with cancer and academic qualification were not significant in influencing knowledge of family history. There is misunderstanding and poor knowledge of family history of cancer and the type of information required to make a family history even in a sample of people teaching and researching medicine and health issues. Public understanding of the value of family medical history in cancer prevention and management is important if informed clinical decisions and appropriate health care are to be delivered. © 2012 John Wiley & Sons Ltd.

Health decision-making preferences among African American men recruited from urban barbershops.

PubMed

Hart, Alton; Smith, Wally R; Tademy, Raymond H; McClish, Donna K; McCreary, Micah

2009-07-01

To examine general health decision-making roles among African American men ages 40 to 70 recruited in barbershops in the Richmond, Virginia, metropolitan area. We adapted the 1-item Control Preference scale to study the associations between health decision-making role preferences and demographic variables. Forty African-American men were recruited from barbershops to complete a self-administered survey. After performing descriptive statistics, we dichotomized our outcome into active vs nonactive (collaborative or passive) decision makers. Data were then analyzed using chi2, Wilcoxon-Mann-Whitney rank sum, and multiple logistic regression. Fifteen subjects responded that they engaged in active decision making, 20 in collaborative, and 5 in passive decision making. Almost all (86.7%) active decision makers were home owners, vs 41.7% of nonactive decision makers. Among active decision makers, 46.7% had incomes of more than $70000, vs 12.5% of nonactive decision makers. The active group reported health status that was good to excellent, while 20.8% of those in the nonactive group reported poor/fair health. African American male barbershop clients preferred an active or collaborative health decision-making role with their physician, rather than a passive role. The relationship among home ownership, income, and decision style may best be understood by considering the historical and cultural influences on gender role socialization among African American males. More comprehensive assessment of decision styles is necessary to better understand health decision making among African American male patients.

Opening the Black Box: Understanding the Science Behind Big Data and Predictive Analytics.

PubMed

Hofer, Ira S; Halperin, Eran; Cannesson, Maxime

2018-05-25

Big data, smart data, predictive analytics, and other similar terms are ubiquitous in the lay and scientific literature. However, despite the frequency of usage, these terms are often poorly understood, and evidence of their disruption to clinical care is hard to find. This article aims to address these issues by first defining and elucidating the term big data, exploring the ways in which modern medical data, both inside and outside the electronic medical record, meet the established definitions of big data. We then define the term smart data and discuss the transformations necessary to make big data into smart data. Finally, we examine the ways in which this transition from big to smart data will affect what we do in research, retrospective work, and ultimately patient care.

Emergency warning for people with disabilities.

PubMed

Putkovich, Kenneth

2013-01-01

The intent of this article is to assess the current state of Emergency Warning capabilities in the United States and make recommendations on what needs to be done to cost effectively establish a National Emergency Warning System to best serve the people of the United States, including those with disabilities. As part of this assessment, terminology will be defined, existing systems will be examined, critical needs and functions will be explained, and recommendations made for a system to deliver emergency messages to those people immediately at risk from natural and human-caused disasters in a timely and effective manner, regardless of location or situational circumstance. The assessment will include the needs and available technologies for delivering emergency warnings to people with disabilities, which are generally little understood, poorly addressed, and often ignored.

Controversies in HIV-associated neurocognitive disorders

PubMed Central

Nightingale, Sam; Winsto, Alan; Letendre, Scott; Michael, Benedict D; McArthur, Justin C; Khoo, Saye; Solomon, Tom

2015-01-01

Cross-sectional studies show that around half of individuals infected with HIV-1 have some degree of cognitive impairment despite the use of antiretroviral drugs. However, prevalence estimates vary depending on the population and methods used to assess cognitive impairment. Whether asymptomatic patients would benefit from routine screening for cognitive difficulties is unclear and the appropriate screening method and subsequent management is the subject of debate. In some patients, HIV-1 RNA can be found at higher concentrations in CSF than in blood, which potentially results from the poor distribution of antiretroviral drugs into the CNS. However, the clinical relevance of so-called CSF viral escape is not well understood. The extent to which antiretroviral drug distribution and toxicity in the CNS affect clinical decision making is also debated. PMID:25316020

Social Information Links Individual Behavior to Population and Community Dynamics.

PubMed

Gil, Michael A; Hein, Andrew M; Spiegel, Orr; Baskett, Marissa L; Sih, Andrew

2018-05-07

When individual animals make decisions, they routinely use information produced intentionally or unintentionally by other individuals. Despite its prevalence and established fitness consequences, the effects of such social information on ecological dynamics remain poorly understood. Here, we synthesize results from ecology, evolutionary biology, and animal behavior to show how the use of social information can profoundly influence the dynamics of populations and communities. We combine recent theoretical and empirical results and introduce simple population models to illustrate how social information use can drive positive density-dependent growth of populations and communities (Allee effects). Furthermore, social information can shift the nature and strength of species interactions, change the outcome of competition, and potentially increase extinction risk in harvested populations and communities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Genes, molecules and patients—Emerging topics to guide clinical pain research

PubMed Central

Sikandar, Shafaq; Patel, Ryan; Patel, Sital; Sikander, Sanam; Bennett, David L.H.; Dickenson, Anthony H.

2013-01-01

This review selectively explores some areas of pain research that, until recently, have been poorly understood. We have chosen four topics that relate to clinical pain and we discuss the underlying mechanisms and related pathophysiologies contributing to these pain states. A key issue in pain medicine involves crucial events and mediators that contribute to normal and abnormal pain signaling, but remain unseen without genetic, biomarker or imaging analysis. Here we consider how the altered genetic make-up of familial pains reveals the human importance of channels discovered by preclinical research, followed by the contribution of receptors as stimulus transducers in cold sensing and cold pain. Finally we review recent data on the neuro-immune interactions in chronic pain and the potential targets for treatment in cancer-induced bone pain. PMID:23500200

Introduced Species, Disease Ecology, and Biodiversity-Disease Relationships.

PubMed

Young, Hillary S; Parker, Ingrid M; Gilbert, Gregory S; Sofia Guerra, Ana; Nunn, Charles L

2017-01-01

Species introductions are a dominant component of biodiversity change but are not explicitly included in most discussions of biodiversity-disease relationships. This is a major oversight given the multitude of effects that introduced species have on both parasitism and native hosts. Drawing on both animal and plant systems, we review the competing mechanistic pathways by which biological introductions influence parasite diversity and prevalence. While some mechanisms - such as local changes in phylogenetic composition and global homogenization - have strong explanatory potential, the net effects of introduced species, especially at local scales, remain poorly understood. Integrative, community-scale studies that explicitly incorporate introduced species are needed to make effective predictions about the effects of realistic biodiversity change and conservation action on disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

The computational worm: spatial orientation and its neuronal basis in C. elegans.

PubMed

Lockery, Shawn R

2011-10-01

Spatial orientation behaviors in animals are fundamental for survival but poorly understood at the neuronal level. The nematode Caenorhabditis elegans orients to a wide range of stimuli and has a numerically small and well-described nervous system making it advantageous for investigating the mechanisms of spatial orientation. Recent work by the C. elegans research community has identified essential computational elements of the neural circuits underlying two orientation strategies that operate in five different sensory modalities. Analysis of these circuits reveals novel motifs including simple circuits for computing temporal derivatives of sensory input and for integrating sensory input with behavioral state to generate adaptive behavior. These motifs constitute hypotheses concerning the identity and functionality of circuits controlling spatial orientation in higher organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Oral splint for temporomandibular joint disorders with revolutionary fluid system

PubMed Central

Srivastava, Rahul; Jyoti, Bhuvan; Devi, Parvathi

2013-01-01

Temporomandibular joint (TMJ) diseases and disorders refer to a complex and poorly understood set of conditions, manifested by pain in the area of the jaw and associated muscles and limitations in the ability to make the normal movements of speech, facial expression, eating, chewing, and swallowing. The conventional soft occlusal splint therapy is a much safer and effective mode of a conservative line of therapy in comparison to the surgical therapy for temporomandibular joint disorders (TMD). The purpose of this article is to review the Aqualizer™, an hydrostatic oral splint, as accurate, effective treatment and differential diagnostic tool in TMD that allow treating the patient's pain quickly and accurately saving valuable treatment time. The review article has been prepared doing a literature review from the world-wide web and pubmed/medline. PMID:24019797

Charting the expansion of strategic exploratory behavior during adolescence.

PubMed

Somerville, Leah H; Sasse, Stephanie F; Garrad, Megan C; Drysdale, Andrew T; Abi Akar, Nadine; Insel, Catherine; Wilson, Robert C

2017-02-01

Although models of exploratory decision making implicate a suite of strategies that guide the pursuit of information, the developmental emergence of these strategies remains poorly understood. This study takes an interdisciplinary perspective, merging computational decision making and developmental approaches to characterize age-related shifts in exploratory strategy from adolescence to young adulthood. Participants were 149 12-28-year-olds who completed a computational explore-exploit paradigm that manipulated reward value, information value, and decision horizon (i.e., the utility that information holds for future choices). Strategic directed exploration, defined as information seeking selective for long time horizons, emerged during adolescence and maintained its level through early adulthood. This age difference was partially driven by adolescents valuing immediate reward over new information. Strategic random exploration, defined as stochastic choice behavior selective for long time horizons, was invoked at comparable levels over the age range, and predicted individual differences in attitudes toward risk taking in daily life within the adolescent portion of the sample. Collectively, these findings reveal an expansion of the diversity of strategic exploration over development, implicate distinct mechanisms for directed and random exploratory strategies, and suggest novel mechanisms for adolescent-typical shifts in decision making. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The effect of boldness on decision-making in barnacle geese is group-size-dependent

PubMed Central

Kurvers, Ralf H. J. M.; Adamczyk, Vena M. A. P.; van Wieren, Sipke E.; Prins, Herbert H. T.

2011-01-01

In group-living species, decisions made by individuals may result in collective behaviours. A central question in understanding collective behaviours is how individual variation in phenotype affects collective behaviours. However, how the personality of individuals affects collective decisions in groups remains poorly understood. Here, we investigated the role of boldness on the decision-making process in different-sized groups of barnacle geese. Naive barnacle geese, differing in boldness score, were introduced in a labyrinth in groups with either one or three informed demonstrators. The demonstrators possessed information about the route through the labyrinth. In pairs, the probability of choosing a route prior to the informed demonstrator increased with increasing boldness score: bolder individuals decided more often for themselves where to go compared with shyer individuals, whereas shyer individuals waited more often for the demonstrators to decide and followed this information. In groups of four individuals, however, there was no effect of boldness on decision-making, suggesting that individual differences were less important with increasing group size. Our experimental results show that personality is important in collective decisions in pairs of barnacle geese, and suggest that bolder individuals have a greater influence over the outcome of decisions in groups. PMID:21123271

The effect of boldness on decision-making in barnacle geese is group-size-dependent.

PubMed

Kurvers, Ralf H J M; Adamczyk, Vena M A P; van Wieren, Sipke E; Prins, Herbert H T

2011-07-07

In group-living species, decisions made by individuals may result in collective behaviours. A central question in understanding collective behaviours is how individual variation in phenotype affects collective behaviours. However, how the personality of individuals affects collective decisions in groups remains poorly understood. Here, we investigated the role of boldness on the decision-making process in different-sized groups of barnacle geese. Naive barnacle geese, differing in boldness score, were introduced in a labyrinth in groups with either one or three informed demonstrators. The demonstrators possessed information about the route through the labyrinth. In pairs, the probability of choosing a route prior to the informed demonstrator increased with increasing boldness score: bolder individuals decided more often for themselves where to go compared with shyer individuals, whereas shyer individuals waited more often for the demonstrators to decide and followed this information. In groups of four individuals, however, there was no effect of boldness on decision-making, suggesting that individual differences were less important with increasing group size. Our experimental results show that personality is important in collective decisions in pairs of barnacle geese, and suggest that bolder individuals have a greater influence over the outcome of decisions in groups.

Isotopic signals of summer denitrification in a northern hardwood forested catchment

Treesearch

Sarah K. Wexler; Christine L. Goodale; Kevin J. McGuire; Scott W. Bailey; Peter M. Groffman

2014-01-01

Despite decades of measurements, the nitrogen balance of temperate forest catchments remains poorly understood. Atmospheric nitrogen deposition often greatly exceeds streamwater nitrogen losses; the fate of the remaining nitrogen is highly uncertain. Gaseous losses of nitrogen to denitrification are especially poorly documented and are often ignored. Here, we provide...

Punishment and Welfare: Paternal Incarceration and Families' Receipt of Public Assistance

ERIC Educational Resources Information Center

Sugie, Naomi F.

2012-01-01

The United States criminal justice and welfare systems are two important government institutions in the lives of the poor. Despite many theoretical discussions about their relationship, their operation at the level of offenders and families remains poorly understood. This paper utilizes Fragile Families and Child Wellbeing data to examine how…

The role of decision-making ability in HIV/AIDS: impact on prospective memory.

PubMed

Coulehan, Kelly; Byrd, Desiree; Arentoft, Alyssa; Monzones, Jennifer; Fuentes, Armando; Fraser, Felicia; Rosario, Ana; Morgello, Susan; Mindt, Monica Rivera

2014-01-01

Prospective memory (ProM), a form of episodic memory related to execution of future intentions, is important for everyday functioning. Among persons living with HIV (PLWH), executive dysfunction is implicated in ProM impairments. However, specific subcomponents of executive functioning involved in ProM deficits remain poorly understood. Unlike more "traditional" neurocognitive (NC) measures of executive functioning associated with dorsolateral prefrontal cortex (i.e., conceptual reasoning, abstraction), those associated with medial orbitofrontal/ventromedial prefrontal (mOF/vmP) cortex (i.e., decision making, inhibitory control, goal-oriented behavior) have yet to be examined in ProM. This study characterized ProM ability in a sample of 89 HIV-seropositive adults and examined the unique role of decision-making ability in ProM. Participants completed a standard NC battery, the Iowa Gambling Task (IGT; a decision-making measure), and the Memory for Intentions Screening Test (MIST; a ProM measure). Correlational analyses revealed that both traditional executive functioning measures and the IGT were associated with ProM. Regression analyses revealed that the IGT significantly predicted ProM, even after accounting for NC measures. Among all NC measures, only executive functioning significantly contributed to ProM. Further examination of mOF/vmP-sensitive executive dysfunction within this population is needed as PLWH may require more tailored treatment recommendations due to specific decision-making difficulties that can impact medication management.

Assessment of cognitive bias in decision-making and leadership styles among critical care nurses: a mixed methods study.

PubMed

Lean Keng, Soon; AlQudah, Hani Nawaf Ibrahim

2017-02-01

To raise awareness of critical care nurses' cognitive bias in decision-making, its relationship with leadership styles and its impact on care delivery. The relationship between critical care nurses' decision-making and leadership styles in hospitals has been widely studied, but the influence of cognitive bias on decision-making and leadership styles in critical care environments remains poorly understood, particularly in Jordan. Two-phase mixed methods sequential explanatory design and grounded theory. critical care unit, Prince Hamza Hospital, Jordan. Participant sampling: convenience sampling Phase 1 (quantitative, n = 96), purposive sampling Phase 2 (qualitative, n = 20). Pilot tested quantitative survey of 96 critical care nurses in 2012. Qualitative in-depth interviews, informed by quantitative results, with 20 critical care nurses in 2013. Descriptive and simple linear regression quantitative data analyses. Thematic (constant comparative) qualitative data analysis. Quantitative - correlations found between rationality and cognitive bias, rationality and task-oriented leadership styles, cognitive bias and democratic communication styles and cognitive bias and task-oriented leadership styles. Qualitative - 'being competent', 'organizational structures', 'feeling self-confident' and 'being supported' in the work environment identified as key factors influencing critical care nurses' cognitive bias in decision-making and leadership styles. Two-way impact (strengthening and weakening) of cognitive bias in decision-making and leadership styles on critical care nurses' practice performance. There is a need to heighten critical care nurses' consciousness of cognitive bias in decision-making and leadership styles and its impact and to develop organization-level strategies to increase non-biased decision-making. © 2016 John Wiley & Sons Ltd.

Evolution of a sediment wave in an experimental channel

Treesearch

Thomas E. Lisle; James E. Pizzuto; Hiroshi Ikeda; Fujiko Iseya; Yoshinori Kodama

1997-01-01

Abstract - The routing of bed material through channels is poorly understood. We approach the problem by observing and modeling the fate of a low-amplitude sediment wave of poorly sorted sand that we introduced into an experimental channel transporting sediment identical to that of the introduced wave. The wave essentially dispersed upstream and downstream without...

Independent Learning--What We Do When You're Not There

ERIC Educational Resources Information Center

Hockings, Christine; Thomas, Liz; Ottaway, Jim; Jones, Rob

2018-01-01

Independent learning is one of the cornerstones of UK higher education yet it is poorly understood by students and is seen by politicians as a poor substitute for face to face teaching. This paper explores students' understandings, approaches and experiences of independent learning and how they may become more effective independent learners. This…

The role of bedrock groundwater in rainfall-runoff response at hillslope and catchment scales

Treesearch

C. Gabrielli; J.J. McDonnell; W.T. Jarvis

2012-01-01

Bedrock groundwater dynamics in headwater catchments are poorly understood and poorly characterized. Direct hydrometric measurements have been limited due to the logistical challenges associated with drilling through hard rock in steep, remote and often roadless terrain. We used a new portable bedrock drilling system to explore bedrock groundwater dynamics aimed at...

Asian and Pacific Islander American Poverty: The Working Poor and the Jobless Poor.

ERIC Educational Resources Information Center

Toji, Dean S.; Johnson, James H.

1992-01-01

Assesses the incidence of Asian-American and Pacific Islander-American poverty, and offers a theoretical explanation for its existence. It is argued that poverty of Americans of Asian and Pacific Island descent is best understood in the context of the linkage of labor migration and U.S. labor market segmentation. (SLD)

'Why didn't you write a not-for-cardiopulmonary resuscitation order?' Unexpected death or failure of process?

PubMed

Levinson, Michele; Mills, Amber; Barrett, Jonathan; Sritharan, Gaya; Gellie, Anthea

2018-02-01

Objective The aim of the present study was to understand the reasons for the delivery of non-beneficial cardiopulmonary resuscitation (CPR) attempts in a tertiary private hospital over 12 months. We determined doctors' expectations of survival after CPR for their patient, whether they had considered a not-for-resuscitation (NFR) order and the barriers to completion of NFR orders. Methods Anonymous questionnaires were sent to the doctors primarily responsible for a given patient's care in the hospital within 2 weeks of the unsuccessful CPR attempt. The data were analysed quantitatively where appropriate and qualitatively for themes for open-text responses Results Most doctors surveyed in the present study understood the poor outcome after CPR in the older person. Most doctors had an expectation that their own patient had a poor prognosis and a poor likely predicted outcome after CPR. This implied that the patient's death was neither unexpected nor likely to be reversible. Some doctors considered NFR orders, but multiple barriers to completion were cited, including the family's wishes, being time poor and diffusion or deferral of responsibility. Conclusions It is likely that futile CPR is provided contrary to policy and legal documents relating to end-of-life care, with the potential for harms relating to both patient and family, and members of resuscitation teams. The failure appears to relate to process rather than recognition of poor patient outcome. What is known about the topic? Mandatory CPR has been established in Australian hospitals on the premise that it will save lives. The outcome from in-hospital cardiac arrest has not improved despite significant training and resources. The outcome for those acutely hospitalised patients aged over 80 years has been repeatedly demonstrated to be poor with significant morbidity in the survivors. There is emerging literature on the extent of the delivery of non-beneficial treatments at the end of life, including futile CPR, the recognition of harms incurred by patients, families and members of the resuscitation teams and on the opportunity cost of the inappropriate use of resources. What does this paper add? This is the first study, to our knowledge, that has demonstrated that doctors understood the outcomes for CPR, particularly in those aged 80 years and older, and that failure to recognise poor outcome and prognosis in their own patients is not a barrier to writing NFR orders. What are the implications for practitioners? Recognition of the poor outcomes from CPR for the elderly patient for whom the doctor has a duty of care should result in a discussion with the patients, allowing an exploration of values and expectations of treatment. This would promote shared decision making, which includes the use of CPR. Facilitation of these discussions should be the focus of health service review.

Cheaper fuel and higher health costs among the poor in rural Nepal.

PubMed

Pant, Krishna Prasad

2012-05-01

Biomass fuels are used by the majority of resource poor households in low-income countries. Though biomass fuels, such as dung-briquette and firewood are apparently cheaper than the modern fuels indoor pollution from burning biomass fuels incurs high health costs. But, the health costs of these conventional fuels, mostly being indirect, are poorly understood. To address this gap, this study develops probit regression models using survey data generated through interviews from households using either dung-briquette or biogas as the primary source of fuel for cooking. The study investigates factors affecting the use of dung-briquette, assesses its impact on human health, and estimates the associated household health costs. Analysis suggests significant effects of dung-briquette on asthma and eye diseases. Despite of the perception of it being a cheap fuel, the annual health cost per household due to burning dung-briquette (US$ 16.94) is 61.3% higher than the annual cost of biogas (US$ 10.38), an alternative cleaner fuel for rural households. For reducing the use of dung-briquette and its indirect health costs, the study recommends three interventions: (1) educate women and aboriginal people, in particular, and make them aware of the benefits of switching to biogas; (2) facilitate tree planting in communal as well as private lands; and (3) create rural employment and income generation opportunities.

Respiratory-deficient mutants of the unicellular green alga Chlamydomonas: a review.

PubMed

Salinas, Thalia; Larosa, Véronique; Cardol, Pierre; Maréchal-Drouard, Laurence; Remacle, Claire

2014-05-01

Genetic manipulation of the unicellular green alga Chlamydomonas reinhardtii is straightforward. Nuclear genes can be interrupted by insertional mutagenesis or targeted by RNA interference whereas random or site-directed mutagenesis allows the introduction of mutations in the mitochondrial genome. This, combined with a screen that easily allows discriminating respiratory-deficient mutants, makes Chlamydomonas a model system of choice to study mitochondria biology in photosynthetic organisms. Since the first description of Chlamydomonas respiratory-deficient mutants in 1977 by random mutagenesis, many other mutants affected in mitochondrial components have been characterized. These respiratory-deficient mutants increased our knowledge on function and assembly of the respiratory enzyme complexes. More recently some of these mutants allowed the study of mitochondrial gene expression processes poorly understood in Chlamydomonas. In this review, we update the data concerning the respiratory components with a special focus on the assembly factors identified on other organisms. In addition, we make an inventory of different mitochondrial respiratory mutants that are inactivated either on mitochondrial or nuclear genes. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Crystal structures of Lymnaea stagnalis AChBP in complex with neonicotinoid insecticides imidacloprid and clothianidin

PubMed Central

Ihara, Makoto; Okajima, Toshihide; Yamashita, Atsuko; Oda, Takuma; Hirata, Koichi; Nishiwaki, Hisashi; Morimoto, Takako; Akamatsu, Miki; Ashikawa, Yuji; Kuroda, Shun’ichi; Mega, Ryosuke; Kuramitsu, Seiki; Sattelle, David B.

2008-01-01

Neonicotinoid insecticides, which act on nicotinic acetylcholine receptors (nAChRs) in a variety of ways, have extremely low mammalian toxicity, yet the molecular basis of such actions is poorly understood. To elucidate the molecular basis for nAChR–neonicotinoid interactions, a surrogate protein, acetylcholine binding protein from Lymnaea stagnalis (Ls-AChBP) was crystallized in complex with neonicotinoid insecticides imidacloprid (IMI) or clothianidin (CTD). The crystal structures suggested that the guanidine moiety of IMI and CTD stacks with Tyr185, while the nitro group of IMI but not of CTD makes a hydrogen bond with Gln55. IMI showed higher binding affinity for Ls-AChBP than that of CTD, consistent with weaker CH–π interactions in the Ls-AChBP–CTD complex than in the Ls-AChBP–IMI complex and the lack of the nitro group-Gln55 hydrogen bond in CTD. Yet, the NH at position 1 of CTD makes a hydrogen bond with the backbone carbonyl of Trp143, offering an explanation for the diverse actions of neonicotinoids on nAChRs. PMID:18338186

The crossing statistic: dealing with unknown errors in the dispersion of Type Ia supernovae

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

Shafieloo, Arman; Clifton, Timothy; Ferreira, Pedro, E-mail: arman@ewha.ac.kr, E-mail: tclifton@astro.ox.ac.uk, E-mail: p.ferreira1@physics.ox.ac.uk

2011-08-01

We propose a new statistic that has been designed to be used in situations where the intrinsic dispersion of a data set is not well known: The Crossing Statistic. This statistic is in general less sensitive than χ{sup 2} to the intrinsic dispersion of the data, and hence allows us to make progress in distinguishing between different models using goodness of fit to the data even when the errors involved are poorly understood. The proposed statistic makes use of the shape and trends of a model's predictions in a quantifiable manner. It is applicable to a variety of circumstances, althoughmore » we consider it to be especially well suited to the task of distinguishing between different cosmological models using type Ia supernovae. We show that this statistic can easily distinguish between different models in cases where the χ{sup 2} statistic fails. We also show that the last mode of the Crossing Statistic is identical to χ{sup 2}, so that it can be considered as a generalization of χ{sup 2}.« less

Successful choice behavior is associated with distinct and coherent network states in anterior cingulate cortex

PubMed Central

Lapish, Christopher C.; Durstewitz, Daniel; Chandler, L. Judson; Seamans, Jeremy K.

2008-01-01

Successful decision making requires an ability to monitor contexts, actions, and outcomes. The anterior cingulate cortex (ACC) is thought to be critical for these functions, monitoring and guiding decisions especially in challenging situations involving conflict and errors. A number of different single-unit correlates have been observed in the ACC that reflect the diverse cognitive components involved. Yet how ACC neurons function as an integrated network is poorly understood. Here we show, using advanced population analysis of multiple single-unit recordings from the rat ACC during performance of an ecologically valid decision-making task, that ensembles of neurons move through different coherent and dissociable states as the cognitive requirements of the task change. This organization into distinct network patterns with respect to both firing-rate changes and correlations among units broke down during trials with numerous behavioral errors, especially at choice points of the task. These results point to an underlying functional organization into cell assemblies in the ACC that may monitor choices, outcomes, and task contexts, thus tracking the animal's progression through “task space.” PMID:18708525

Assembly and enlargement of the primary cell wall in plants

NASA Technical Reports Server (NTRS)

Cosgrove, D. J.

1997-01-01

Growing plant cells are shaped by an extensible wall that is a complex amalgam of cellulose microfibrils bonded noncovalently to a matrix of hemicelluloses, pectins, and structural proteins. Cellulose is synthesized by complexes in the plasma membrane and is extruded as a self-assembling microfibril, whereas the matrix polymers are secreted by the Golgi apparatus and become integrated into the wall network by poorly understood mechanisms. The growing wall is under high tensile stress from cell turgor and is able to enlarge by a combination of stress relaxation and polymer creep. A pH-dependent mechanism of wall loosening, known as acid growth, is characteristic of growing walls and is mediated by a group of unusual wall proteins called expansins. Expansins appear to disrupt the noncovalent bonding of matrix hemicelluloses to the microfibril, thereby allowing the wall to yield to the mechanical forces generated by cell turgor. Other wall enzymes, such as (1-->4) beta-glucanases and pectinases, may make the wall more responsive to expansin-mediated wall creep whereas pectin methylesterases and peroxidases may alter the wall so as to make it resistant to expansin-mediated creep.

Assembly and enlargement of the primary cell wall in plants.

PubMed

Cosgrove, D J

1997-01-01

Growing plant cells are shaped by an extensible wall that is a complex amalgam of cellulose microfibrils bonded noncovalently to a matrix of hemicelluloses, pectins, and structural proteins. Cellulose is synthesized by complexes in the plasma membrane and is extruded as a self-assembling microfibril, whereas the matrix polymers are secreted by the Golgi apparatus and become integrated into the wall network by poorly understood mechanisms. The growing wall is under high tensile stress from cell turgor and is able to enlarge by a combination of stress relaxation and polymer creep. A pH-dependent mechanism of wall loosening, known as acid growth, is characteristic of growing walls and is mediated by a group of unusual wall proteins called expansins. Expansins appear to disrupt the noncovalent bonding of matrix hemicelluloses to the microfibril, thereby allowing the wall to yield to the mechanical forces generated by cell turgor. Other wall enzymes, such as (1-->4) beta-glucanases and pectinases, may make the wall more responsive to expansin-mediated wall creep whereas pectin methylesterases and peroxidases may alter the wall so as to make it resistant to expansin-mediated creep.

Smokers' knowledge and understanding of advertised tar numbers: health policy implications.

PubMed

Cohen, J B

1996-01-01

This article examines health policy implications of providing smokers with numerical tar yield information in cigarette advertising. Results of a national probability telephone survey regarding smokers' knowledge and understanding of numerical tar yields and deliveries are reported. Few smokers knew the tar level of their own cigarettes (the exception being smokers of 1- to 5-mg tar cigarettes), and a majority could not correctly judge the relative tar levels of cigarettes. Smokers were unsure whether switching to lower-tar cigarettes would reduce their personal health risks. Many smokers relied on absolute numbers in making trade-offs between number of cigarettes smoked and their tar levels, thus confusion machine-rated tar-yields with actual amounts ingested. The wisdom of the present method of providing tar and nicotine numbers in ads and recommendations for modifying the test protocol are now under discussion. This research indicates that these tar numbers and their implications are poorly understood. The paper recommends revisions in tar ratings to make them more useful and a required statement on cigarette packages to more explicitly relate tar levels to major health risks.

Smokers' knowledge and understanding of advertised tar numbers: health policy implications.

PubMed Central

Cohen, J B

1996-01-01

OBJECTIVES. This article examines health policy implications of providing smokers with numerical tar yield information in cigarette advertising. METHODS. Results of a national probability telephone survey regarding smokers' knowledge and understanding of numerical tar yields and deliveries are reported. RESULTS. Few smokers knew the tar level of their own cigarettes (the exception being smokers of 1- to 5-mg tar cigarettes), and a majority could not correctly judge the relative tar levels of cigarettes. Smokers were unsure whether switching to lower-tar cigarettes would reduce their personal health risks. Many smokers relied on absolute numbers in making trade-offs between number of cigarettes smoked and their tar levels, thus confusion machine-rated tar-yields with actual amounts ingested. CONCLUSIONS. The wisdom of the present method of providing tar and nicotine numbers in ads and recommendations for modifying the test protocol are now under discussion. This research indicates that these tar numbers and their implications are poorly understood. The paper recommends revisions in tar ratings to make them more useful and a required statement on cigarette packages to more explicitly relate tar levels to major health risks. PMID:8561236

Surface tension propulsion of fungal spores by use of microdroplets

NASA Astrophysics Data System (ADS)

Noblin, Xavier; Yang, Sylvia; Dumais, Jacques

2010-11-01

Most basidiomycete fungi (such as edible mushrooms) actively eject their spores. The process begins with the condensation of a water droplet at the base of the spore. The fusion of the droplet onto the spore creates a momentum that propels the spore forward. The use of surface tension for spore ejection offers a new paradigm to perform work at small length scales. However, this mechanism of force generation remains poorly understood. To elucidate how fungal spores make effective use of surface tension, we performed high-speed video imaging of spore ejection in Auricularia auricula and Sporobolomyces yeast, along with a detailed mechanical analysis of the spore ejection. We developed an explicit relation for the conversion of surface energy into kinetic energy during the coalescence process. The relation was validated with a simple artificial system.

Conflicting health information: a critical research need.

PubMed

Carpenter, Delesha M; Geryk, Lorie L; Chen, Annie T; Nagler, Rebekah H; Dieckmann, Nathan F; Han, Paul K J

2016-12-01

Conflicting health information is increasing in amount and visibility, as evidenced most recently by the controversy surrounding the risks and benefits of childhood vaccinations. The mechanisms through which conflicting information affects individuals are poorly understood; thus, we are unprepared to help people process conflicting information when making important health decisions. In this viewpoint article, we describe this problem, summarize insights from the existing literature on the prevalence and effects of conflicting health information, and identify important knowledge gaps. We propose a working definition of conflicting health information and describe a conceptual typology to guide future research in this area. The typology classifies conflicting information according to four fundamental dimensions: the substantive issue under conflict, the number of conflicting sources (multiplicity), the degree of evidence heterogeneity and the degree of temporal inconsistency. © 2015 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Genetic models of homosexuality: generating testable predictions

PubMed Central

Gavrilets, Sergey; Rice, William R

2006-01-01

Homosexuality is a common occurrence in humans and other species, yet its genetic and evolutionary basis is poorly understood. Here, we formulate and study a series of simple mathematical models for the purpose of predicting empirical patterns that can be used to determine the form of selection that leads to polymorphism of genes influencing homosexuality. Specifically, we develop theory to make contrasting predictions about the genetic characteristics of genes influencing homosexuality including: (i) chromosomal location, (ii) dominance among segregating alleles and (iii) effect sizes that distinguish between the two major models for their polymorphism: the overdominance and sexual antagonism models. We conclude that the measurement of the genetic characteristics of quantitative trait loci (QTLs) found in genomic screens for genes influencing homosexuality can be highly informative in resolving the form of natural selection maintaining their polymorphism. PMID:17015344

Sediment, land use, and freshwater mussels: Prospects and problems

USGS Publications Warehouse

Brim-Box, J.; Mossa, J.

1999-01-01

The decline in freshwater mussel populations in many river basins throughout North America has been attributed, in part, to land-use modifications that cause changes in sediment regimes. However, the specific associations that mussels have with stream sediments are poorly understood, making it difficult to assess the impacts of changes in sedimentation rates on unionid mussels. Both bed and suspended materials, and concomitant changes in channel form associated with changes in sediment supply, may affect mussels in numerous ways at various stages in their life cycle. Considerable debate and uncertainty remains regarding the strength of associations between sediments and mussels, including whether increased sedimentation is a cause of recent mussel declines. It is important to be aware of appropriate procedures for sampling and analyzing fluvial sediments, and the nature of sediment sources, to adequately assess relationships between unionid mussels and fluvial sediments.

Elevated arousal levels enhance contrast perception.

PubMed

Kim, Dongho; Lokey, Savannah; Ling, Sam

2017-02-01

Our state of arousal fluctuates from moment to moment-fluctuations that can have profound impacts on behavior. Arousal has been proposed to play a powerful, widespread role in the brain, influencing processes as far ranging as perception, memory, learning, and decision making. Although arousal clearly plays a critical role in modulating behavior, the mechanisms underlying this modulation remain poorly understood. To address this knowledge gap, we examined the modulatory role of arousal on one of the cornerstones of visual perception: contrast perception. Using a reward-driven paradigm to manipulate arousal state, we discovered that elevated arousal state substantially enhances visual sensitivity, incurring a multiplicative modulation of contrast response. Contrast defines vision, determining whether objects appear visible or invisible to us, and these results indicate that one of the consequences of decreased arousal state is an impaired ability to visually process our environment.

Einstein's Jury: Trial by Telescope

NASA Astrophysics Data System (ADS)

Crelinsten, Jeffrey

2007-03-01

While Einstein's theory of relativity ultimately laid the foundation for modern studies of the universe, it took a long time to be accepted. Between 1905 and 1930, relativity was poorly understood and Einstein worked hard to try to make it more accessible to scientists and scientifically literate laypeople. Its acceptance was largely due to the astronomy community, which undertook precise measurements to test Einstein's astronomical predictions. The well-known 1919 British eclipse expeditions that made Einstein famous did not convince most scientists to accept relativity. The 1920s saw numerous attempts to measure light-bending, as well as solar line displacements and even ether-drift. How astronomers approached the ``Einstein problem'' in these early years before and after the First World War, and how the public reacted to what they reported, helped to shape attitudes we hold today about Einstein and his ideas.

Cancer Patient Navigator Tasks across the Cancer Care Continuum

PubMed Central

Braun, Kathryn L.; Kagawa-Singer, Marjorie; Holden, Alan E. C.; Burhansstipanov, Linda; Tran, Jacqueline H.; Seals, Brenda F.; Corbie-Smith, Giselle; Tsark, JoAnn U.; Harjo, Lisa; Foo, Mary Anne; Ramirez, Amelie G.

2011-01-01

Cancer patient navigation (PN) programs have been shown to increase access to and utilization of cancer care for poor and underserved individuals. Despite mounting evidence of its value, cancer patient navigation is not universally understood or provided. We describe five PN programs and the range of tasks their navigators provide across the cancer care continuum (education and outreach, screening, diagnosis and staging, treatment, survivorship, and end-of-life). Tasks are organized by their potential to make cancer services understandable, available, accessible, affordable, appropriate, and accountable. Although navigators perform similar tasks across the five programs, their specific approaches reflect differences in community culture, context, program setting, and funding. Task lists can inform the development of programs, job descriptions, training, and evaluation. They also may be useful in the move to certify navigators and establish mechanisms for reimbursement for navigation services. PMID:22423178

Biofiltration of Volatile Pollutants: Engineering Mechanisms for Improved Design, Long-term Operation, Prediction and Implementation

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

Davison, Brian H.

1999-06-01

Biofiltration systems can be used for treatment of volatile organic compounds (VOCs); however, the systems are poorly understood and are currently operated as ''black boxes''. Common operational problems associated with biofilters include fouling, deactivation, and overgrowth, all of which make them ineffective for continuous, long-term use. The objective of this investigation is to develop generic methods for longterm stable operation, in particular by using selective limitation of supplemental nutrients while maintaining high activity. As part of this effort, we will provide deeper fundamental understanding of the important biological and transport mechanisms in biodestruction of sparingly soluble VOCs and extend thismore » approach and mathematical models to additional systems of high priority EM relevance--direct degradation and cometabolic degradation of priority pollutants such as BTEX and chlorinated organics.« less

BIOFILTRATION OF VOLATILE POLLUTANTS: Fundamental Mechanisms for Improved Design, Long-term Operation, Prediction, and Implementation

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

Davison, Brian H.; Klasson, K. Thomas; Barton, John W.

2000-06-01

Biofiltration systems can be used for treatment of volatile organic compounds (VOCs); however, the systems are poorly understood and are currently operated as ''black boxes''. Common operational problems associated with biofilters include fouling, deactivation, and overgrowth, all of which make them ineffective for continuous, long-term use. The objective of this investigation is to develop generic methods for long-term stable operation, in particular by using selective limitation of supplemental nutrients while maintaining high activity. As part of this effort, we will provide deeper fundamental understanding of the important biological and transport mechanisms in biodestruction of sparingly soluble VOCs and extend thismore » approach and mathematical models to additional systems of high priority EM relevance--direct degradation and cometabolic degradation of priority pollutants such as BTEX and chlorinated organics.« less

Inheritance Patterns in Citation Networks Reveal Scientific Memes

NASA Astrophysics Data System (ADS)

Kuhn, Tobias; Perc, Matjaž; Helbing, Dirk

2014-10-01

Memes are the cultural equivalent of genes that spread across human culture by means of imitation. What makes a meme and what distinguishes it from other forms of information, however, is still poorly understood. Our analysis of memes in the scientific literature reveals that they are governed by a surprisingly simple relationship between frequency of occurrence and the degree to which they propagate along the citation graph. We propose a simple formalization of this pattern and validate it with data from close to 50 million publication records from the Web of Science, PubMed Central, and the American Physical Society. Evaluations relying on human annotators, citation network randomizations, and comparisons with several alternative approaches confirm that our formula is accurate and effective, without a dependence on linguistic or ontological knowledge and without the application of arbitrary thresholds or filters.

Cutting-edge endonasal surgical approaches to thyroid ophthalmopathy.

PubMed

Tyler, Matthew A; Zhang, Caroline C; Saini, Alok T; Yao, William C

2018-04-01

Thyroid orbitopathy is a poorly understood extrathyroidal manifestation of Graves' disease that can cause disfiguring proptosis and vision loss. Orbital decompression surgery for Graves' orbitopathy (GO) can address both cosmetic and visual sequelae of this autoimmune condition. Endonasal endoscopic orbital decompression provides unmatched visualization and access to inferomedial orbital wall and orbital apex. This review examines the state of the art approaches employed in endonasal endoscopic orbital decompression for GO. Review of literature evaluating novel surgical maneuvers for GO. Studies examining the efficacy of endonasal endoscopic orbital decompression are heterogenous and retrospective in design; however, they reveal this approach to be a safe and effective technique in the management of GO. Subtle variations in endoscopic techniques significantly affect postsurgical outcomes and can be tailored to the specific clinical indication in GO making endonasal endoscopic decompression the most versatile approach available. NA.

The properties and causes of rippling in quasi-perpendicular collisionless shock fronts

NASA Astrophysics Data System (ADS)

Lowe, R. E.; Burgess, D.

2003-03-01

The overall structure of quasi-perpendicular, high Mach number collisionless shocks is controlled to a large extent by ion reflection at the shock ramp. Departure from a strictly one-dimensional structure is indicated by simulation results showing that the surface of such shocks is rippled, with variations in the density and all field components. We present a detailed analysis of these shock ripples, using results from a two-dimensional hybrid (particle ions, electron fluid) simulation. The process that generates the ripples is poorly understood, because the large gradients at the shock ramp make it difficult to identify instabilities. Our analysis reveals new features of the shock ripples, which suggest the presence of a surface wave mode dominating the shock normal magnetic field component of the ripples, as well as whistler waves excited by reflected ions.

Why does starvation make bones fat?

PubMed Central

Devlin, Maureen J.

2011-01-01

Body fat, or adipose tissue, is a crucial energetic buffer against starvation in humans and other mammals, and reserves of white adipose tissue (WAT) rise and fall in parallel with food intake. Much less is known about the function of bone marrow adipose tissue (BMAT), which are fat cells found in bone marrow. BMAT mass actually increases during starvation, even as other fat depots are being mobilized for energy. Here I review the possible reasons for this poorly understood phenomenon. Is BMAT a passive filler that occupies spaces left by dying bone cells, a pathological consequence of suppressed bone formation, or potentially an adaptation for surviving starvation? To evaluate these possibilities, here I review what is known about the effects of starvation on the body, particularly the skeleton, and the mechanisms involved in storing and metabolizing BMAT during negative energy balance. PMID:21793093

Why does starvation make bones fat?

PubMed

Devlin, Maureen J

2011-01-01

Body fat, or adipose tissue, is a crucial energetic buffer against starvation in humans and other mammals, and reserves of white adipose tissue (WAT) rise and fall in parallel with food intake. Much less is known about the function of bone marrow adipose tissue (BMAT), which are fat cells found in bone marrow. BMAT mass actually increases during starvation, even as other fat depots are being mobilized for energy. This review considers several possible reasons for this poorly understood phenomenon. Is BMAT a passive filler that occupies spaces left by dying bone cells, a pathological consequence of suppressed bone formation, or potentially an adaptation for surviving starvation? These possibilities are evaluated in terms of the effects of starvation on the body, particularly the skeleton, and the mechanisms involved in storing and metabolizing BMAT during negative energy balance. Copyright © 2011 Wiley-Liss, Inc.

Artificial intelligence for breast cancer screening: Opportunity or hype?

PubMed

Houssami, Nehmat; Lee, Christoph I; Buist, Diana S M; Tao, Dacheng

2017-12-01

Interpretation of mammography for breast cancer (BC) screening can confer a mortality benefit through early BC detection, can miss a cancer that is present or fast growing, or can result in false-positives. Efforts to improve screening outcomes have mostly focused on intensifying imaging practices (double instead of single-reading, more frequent screens, or supplemental imaging) that may add substantial resource expenditures and harms associated with population screening. Less attention has been given to making mammography screening practice 'smarter' or more efficient. Artificial intelligence (AI) is capable of advanced learning using large complex datasets and has the potential to perform tasks such as image interpretation. With both highly-specific capabilities, and also possible un-intended (and poorly understood) consequences, this viewpoint considers the promise and current reality of AI in BC detection. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Small Acceptance Vertex Detector of NA61/SHINE

NASA Astrophysics Data System (ADS)

Deveaux, M.; Aduszkiewicz, A.; Ali, Y.; Baszczyk, M.; Brylinski, W.; Dorosz, P.; Di Luise, S.; Feofilov, G.; Gazdzicki, M.; Igolkin, S.; Jablonski, M.; Kovalenko, V.; Koziel, M.; Kucewicz, W.; Larsen, D.; Lazareva, T.; Martinengo, P.; Merzlaya, A.; Mik, L.; Planeta, R.; Snoch, A.; Vechernin, V.; Tefelski, D.; Suljic, M.; Staszel, P.

2018-02-01

Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150 AGeV/c Pb+Pb collision system will be reported.

What does productivity really mean? Towards an integrative paradigm in the search for biodiversity-productivity relationships

Treesearch

Liangjun Hu; Qinfeng Guo

2013-01-01

How species diversity relates to productivity remains a major debate. To date, however, the underlying mechanisms that regulate the ecological processes involved are still poorly understood. Three major issues persist in early efforts at resolution. First, in the context that productivity drives species diversity, how the pathways operate is poorly-explained. Second,...

Low serum omega-3 and omega-6 polyunsaturated fatty acids and other metabolites are associated with poor linear growth in young children from rural Malawi

USDA-ARS?s Scientific Manuscript database

Stunting affects ~25% of children <5 y of age and is associated with impaired cognitive and motor development and increased morbidity and mortality. The pathogenesis of stunting is poorly understood. The purpose of this study was to identify altered metabolic pathways associated with child stunting...

The potential of critical social theory as an educational framework for people with epilepsy.

PubMed

Bennett, Louise; Bergin, Michael; Wells, John S G

2016-01-01

Effective education can support people with epilepsy to develop the attributes and skills required to function as equal partners with clinical service providers, make informed decisions, and competently self-manage their healthcare. However, despite knowledge deficits, unmet information needs, and a poor sense of empowerment, the study of education for people with epilepsy is often neglected and is a poorly understood component of holistic practice within epilepsy healthcare. Historically, the only debate with regard to education and people with epilepsy has been guided either within a positivist or within a constructivist philosophy. We argue that new pedagogies are warranted, recognizing the views of people with epilepsy regarding their illness. Therefore, this paper explores the potential of an educational framework for people with epilepsy based upon critical social theory (CST). By utilizing a CST approach for education, people with epilepsy are engaged with as active 'participants'. This is a key difference that distinguishes CST from other metatheoretical frameworks. It has the potential to support people with epilepsy to acquire the skills and confidence to manage the biopsychosocial challenges associated with their condition. Copyright © 2015 Elsevier Inc. All rights reserved.

Color discrimination deficits in Parkinson's disease are related to cognitive impairment and white-matter alterations.

PubMed

Bertrand, Josie-Anne; Bedetti, Christophe; Postuma, Ronald B; Monchi, Oury; Génier Marchand, Daphné; Jubault, Thomas; Gagnon, Jean-François

2012-12-01

Color discrimination deficit is a common nonmotor manifestation of Parkinson's disease (PD). However, the pathophysiology of this dysfunction remains poorly understood. Although retinal structure changes found in PD have been suggested to cause color discrimination deficits, the impact of cognitive impairment and cortical alterations remains to be determined. We investigated the contribution of cognitive impairment to color discrimination deficits in PD and correlated them with cortical anomalies. Sixty-six PD patients without dementia and 20 healthy controls performed the Farnsworth-Munsell 100 hue test and underwent a comprehensive neuropsychological assessment for mild cognitive impairment diagnosis. In a subgroup of 26 PD patients, we also used high-definition neuroanatomical magnetic resonance imaging for cortical thickness and diffusion tensor analysis. PD patients with mild cognitive impairment performed poorly on the Farnsworth-Munsell 100 hue test compared with PD patients without mild cognitive impairment and controls. In PD patients, performance on the Farnsworth-Munsell 100 hue test was correlated with measures of visuospatial abilities and executive functions. Neuroimaging analysis revealed higher mean and radial diffusivity values in right posterior white-matter structures that correlated with poor performance on the Farnsworth-Munsell 100 hue test. No cortical thickness correlation reached significance. This study showed that cognitive impairment makes a major contribution to the color discrimination deficits reported in PD. Thus, performance on the Farnsworth-Munsell 100 hue test may reflect cognitive impairment more than color discrimination deficits in PD. Poor performance on the Farnsworth-Munsell 100 hue test was also associated with white-matter alterations in right posterior brain regions. Copyright © 2012 Movement Disorder Society.

Adolescent Risk Taking, Cocaine Self-Administration, and Striatal Dopamine Signaling

PubMed Central

Mitchell, Marci R; Weiss, Virginia G; Beas, B Sofia; Morgan, Drake; Bizon, Jennifer L; Setlow, Barry

2014-01-01

Poor decision making and elevated risk taking, particularly during adolescence, have been strongly linked to drug use; however the causal relationships among these factors are not well understood. To address these relationships, a rat model (the Risky Decision-making Task; RDT) was used to determine whether individual differences in risk taking during adolescence predict later propensity for cocaine self-administration and/or whether cocaine self-administration causes alterations in risk taking. In addition, the RDT was used to determine how risk taking is modulated by dopamine signaling, particularly in the striatum. Results from these experiments indicated that greater risk taking during adolescence predicted greater intake of cocaine during acquisition of self-administration in adulthood, and that adult cocaine self-administration in turn caused elevated risk taking that was present following 6 weeks of abstinence. Greater adolescent risk taking was associated with lower striatal D2 receptor mRNA expression, and pharmacological activation of D2/3 receptors in the ventral, but not dorsal, striatum induced a decrease in risk taking. These findings indicate that the relationship between elevated risk taking and cocaine self-administration is bi-directional, and that low striatal D2 receptor expression may represent a predisposing factor for both maladaptive decision making and cocaine use. Furthermore, these findings suggest that striatal D2 receptors represent a therapeutic target for attenuating maladaptive decision making when choices include risk of adverse consequences. PMID:24145852

Appropriate and inappropriate influences on outpatient discharge decision making in dermatology: a prospective qualitative study.

PubMed

Harun, N A; Finlay, A Y; Salek, M S; Piguet, V

2015-09-01

Outpatient discharge decision making in dermatology is poorly understood. To identify the influences on clinicians' thought processes when making discharge decisions in dermatology outpatient clinics. Forty clinicians from 11 National Health Service Trusts in England were interviewed. The interviews were audiorecorded, transcribed, coded and thematically analysed. The mean age of the clinicians was 48.8 years (range 33.0-67.0), 17 (43%) were men and 19 (48%) had > 20 years of clinical experience. One hundred and forty-eight influences were reported, with five main themes: (i) disease-based influences included type of diagnosis (100% of clinicians), guidelines (100%) and treatment needed (100%); (ii) clinician-based influences included the clinician's level of experience (100%), seniority (37%), emotional attitude (95%), 'gut feeling' (25%), personal attitude towards discharge (45%) and level of perception (100%); (iii) patient-based influences included patients' ability to cope with their disease (100%), wishes (70%), quality of life (32%), command of English (40%) and cultural background (25%); (iv) practice-based influences included good primary care (100%), secondary support structure (100%) and clinic capacity pressure (67%); (v) policy-based influences included pressure from hospital managers (57%) and an active discharge policy (7%). Fourteen (9%) influences were potentially inappropriate. This study has identified multiple factors influencing outpatient discharge decision making. This provides the basis for developing evidence-based training to improve discharge decision appropriateness. © 2015 British Association of Dermatologists.

Lateral, not medial, prefrontal cortex contributes to punishment and aversive instrumental learning

PubMed Central

Jean-Richard-dit-Bressel, Philip

2016-01-01

Aversive outcomes punish behaviors that cause their occurrence. The prefrontal cortex (PFC) has been implicated in punishment learning and behavior, although the exact roles for different PFC regions in instrumental aversive learning and decision-making remain poorly understood. Here, we assessed the role of the orbitofrontal (OFC), rostral agranular insular (RAIC), prelimbic (PL), and infralimbic (IL) cortex in instrumental aversive learning and decision-making. Rats that pressed two individually presented levers for pellet rewards rapidly suppressed responding to one lever if it also caused mild punishment (punished lever) but continued pressing the other lever that did not cause punishment (unpunished lever). Inactivations of OFC, RAIC, IL, or PL via the GABA agonists baclofen and muscimol (BM) had no effect on the acquisition of instrumental learning. OFC inactivations increased responding on the punished lever during expression of well-learned instrumental aversive learning, whereas RAIC inactivations increased responding on the punished lever when both levers were presented simultaneously in an unpunished choice test. There were few effects of medial PFC (PL and IL) inactivation. These results suggest that lateral PFC, notably OFC and RAIC, have complementary functions in aversive instrumental learning and decision-making; OFC is important for using established aversive instrumental memories to guide behavior away from actions that cause punishment, whereas RAIC is important for aversive decision-making under conditions of choice. PMID:27918280

Digestive tract absorption of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in a nursing infant

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

McLachlan, M.S.

The digestive tract absorption of environmental contaminants is an important but poorly understood parameter in contaminant is an important but poorly understood parameter in contaminant risk assessments. The net absorption of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in a nursing infant was measured under natural conditions over 12 days. The levels of the substances in the mother's milk were typical for Germany. It was found that for almost all congeners over 90% of the ingested compound was absorbed. This indicates that the common assumption of 100% absorption in nursing infants is reasonable. No firm conclusions could be drawn regarding the absorptionmore » of Cl7- and Cl8DD/F due to high blank levels in the cotton diapers used.« less

Poorly Understood Aspects of Striated Muscle Contraction

PubMed Central

Månsson, Alf

2015-01-01

Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs. PMID:25961006

Poorly understood aspects of striated muscle contraction.

PubMed

Månsson, Alf; Rassier, Dilson; Tsiavaliaris, Georgios

2015-01-01

Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs.

The role of decision-making ability in HIV/AIDS: Impact on prospective memory

PubMed Central

Coulehan, Kelly; Byrd, Desiree; Arentoft, Alyssa; Monzones, Jennifer; Fuentes, Armando; Fraser, Felicia; Rosario, Ana; Morgello, Susan; Rivera Mindt, Monica

2017-01-01

Background Prospective memory (ProM), a form of episodic memory related to execution of future intentions, is important for everyday functioning. Among persons living with HIV (PLWH), executive dysfunction is implicated in ProM impairments. However, specific subcomponents of executive functioning involved in ProM deficits remain poorly understood. Unlike more “traditional” neurocognitive (NC) measures of executive functioning associated with dorsolateral prefrontal cortex (i.e., conceptual reasoning, abstraction), those associated with medial orbitofrontal/ventromedial prefrontal (mOF/vmP) cortex (i.e., decision making, inhibitory control, goal-oriented behavior) have yet to be examined in ProM. Method This study characterized ProM ability in a sample of 89 HIV-seropositive adults and examined the unique role of decision-making ability in ProM. Participants completed a standard NC battery, the Iowa Gambling Task (IGT; a decision-making measure), and the Memory for Intentions Screening Test (MIST; a ProM measure). Results Correlational analyses revealed that both traditional executive functioning measures and the IGT were associated with ProM. Regression analyses revealed that the IGT significantly predicted ProM, even after accounting for NC measures. Among all NC measures, only executive functioning significantly contributed to ProM. Discussion Further examination of mOF/vmP-sensitive executive dysfunction within this population is needed as PLWH may require more tailored treatment recommendations due to specific decision-making difficulties that can impact medication management. PMID:25089330

What is the veterinary professional identity? Preliminary findings from web-based continuing professional development in veterinary professionalism.

PubMed

Armitage-Chan, E; Maddison, J; May, S A

2016-03-26

Professionalism and professional skills are increasingly being incorporated into veterinary curricula; however, lack of clarity in defining veterinary professionalism presents a potential challenge for directing course outcomes that are of benefit to the veterinary professional. An online continuing education course in veterinary professionalism was designed to address a deficit in postgraduate support in this area; as part of this course, delegates of varying practice backgrounds participated in online discussions reflecting on the implications of professional skills for their clinical practice. The discussions surrounding the role of the veterinary professional and reflecting on strengths and weaknesses in professional skills were analysed using narrative methodology, which provided an understanding of the defining skills and attributes of the veterinary professional, from the perspectives of those involved (i.e. how vets understood their own career identity). The veterinary surgeon was understood to be an interprofessional team member, who makes clinical decisions in the face of competing stakeholder needs and works in a complex environment comprising multiple and diverse challenges (stress, high emotions, financial issues, work-life balance). It was identified that strategies for accepting fallibility, and those necessary for establishing reasonable expectations of professional behaviour and clinical ability, are poorly developed. British Veterinary Association.

Linking Early Environmental Exposures to Adult Diseases

MedlinePlus

... diseases. Given that many disorders arise during fetal development from disruptions in the dynamic but still poorly understood interplay of genes, environment and nutrition, prevention may have to occur decades ...

Smoke and mirrors: Testing the scope of chimpanzees’ appearance-reality understanding

PubMed Central

Lurz, Robert; Russell, Jamie L.; Hopkins, William D.

2016-01-01

The ability to make appearance-reality (AR) discriminations is an important higher-order cognitive adaptation in humans but is still poorly understood in our closest primate relatives. Previous research showed that chimpanzees are capable of AR discrimination when choosing between food items that appear, due to the effects of distorting lenses, to be smaller or larger than they actually are (Krachun, Call & Tomasello, 2009). In the current study, we investigated the scope and flexibility of chimpanzees’ AR discrimination abilities by presenting them with a wider range of illusory stimuli. In addition to using lenses to change the apparent size of food items (Experiment 1), we used a mirror to change the apparent number of items (Experiment 2), and tinted filters to change their apparent color (Experiment 3). In all three experiments, some chimpanzees were able to maximize their food rewards by making a choice based on the real properties of the stimuli in contrast to their manifest apparent properties. These results replicate the earlier findings for size illusions and extend them to additional situations involving illusory number and color. Control tests, together with findings from previous studies, ruled out lower-level explanations for the chimpanzees’ performance. The findings thus support the hypothesis that chimpanzees are capable of making AR discriminations with a range of illusory stimuli. PMID:26848736

"Not here": making the spaces and subjects of "global health" in Botswana.

PubMed

Brada, Betsey

2011-06-01

This essay argues that what makes "global health" "global" has more to do with configurations of space and time, and the claims to expertise and moral stances these configurations make possible, than with the geographical distribution of medical experts or the universal, if also uneven, distribution of threats to health. Drawing on a study of public-private partnerships supporting Botswana's HIV/AIDS treatment program, this essay demonstrates ethnographically the processes by which "global health" and its quintessential spaces, namely "resource-limited" or "resource-poor settings," are constituted, reinforced, and contested in the context of medical education and medical practice in Botswana's largest hospital. Using Silverstein's work on orders of indexicality, I argue that the terms of "global health" are best understood as chronotopic, and demonstrate how actors orient themselves and others spatio-temporally, morally, and professionally by using or refuting those terms. I conclude by arguing that taking "global health" on its own terms obscures the powerful forces by which it becomes intelligible. At stake are the frames within which medical anthropologists understand their objects of study, as well as the potential for the spaces of "global health" intervention to expand ever outward as American medical personnel attempt to calibrate their experiences to their expectations.

An inexpensive and portable drill rig for bedrock groundwater studies in headwater catchments

Treesearch

C. Gabrielli; J.J. McDonnell

2011-01-01

Bedrock groundwater dynamics in headwater catchments are poorly understood and poorly characterized. Here, we present an inexpensive and portable bedrock drilling system designed for use in remote locations. Our system is capable of drilling bedrock wells up to 11 m deep and 38 mm in diameter in a wide range of bedrock types. The drill consists of a lawn mower engine...

Researchers Realize Major Breakthrough in Understanding Endometriosis

MedlinePlus

... a rarely studied and poorly understood disease that affects many, many women.” Health Terms: Women's Health RELATED LINKS RSS LISTSERV YOUTUBE FACEBOOK TWITTER GOOGLE+ NIH...T URNING D ISCOVERY I ...

Exploratory Decision-Making as a Function of Lifelong Experience, Not Cognitive Decline

PubMed Central

2016-01-01

Older adults perform worse than younger adults in some complex decision-making scenarios, which is commonly attributed to age-related declines in striatal and frontostriatal processing. Recently, this popular account has been challenged by work that considered how older adults’ performance may differ as a function of greater knowledge and experience, and by work showing that, in some cases, older adults outperform younger adults in complex decision-making tasks. In light of this controversy, we examined the performance of older and younger adults in an exploratory choice task that is amenable to model-based analyses and ostensibly not reliant on prior knowledge. Exploration is a critical aspect of decision-making poorly understood across the life span. Across 2 experiments, we addressed (a) how older and younger adults differ in exploratory choice and (b) to what extent observed differences reflect processing capacity declines. Model-based analyses suggested that the strategies used by the 2 groups were qualitatively different, resulting in relatively worse performance for older adults in 1 decision-making environment but equal performance in another. Little evidence was found that differences in processing capacity drove performance differences. Rather the results suggested that older adults’ performance might result from applying a strategy that may have been shaped by their wealth of real-word decision-making experience. While this strategy is likely to be effective in the real world, it is ill suited to some decision environments. These results underscore the importance of taking into account effects of experience in aging studies, even for tasks that do not obviously tap past experiences. PMID:26726916

Models for small-scale structure on cosmic strings. II. Scaling and its stability

NASA Astrophysics Data System (ADS)

Vieira, J. P. P.; Martins, C. J. A. P.; Shellard, E. P. S.

2016-11-01

We make use of the formalism described in a previous paper [Martins et al., Phys. Rev. D 90, 043518 (2014)] to address general features of wiggly cosmic string evolution. In particular, we highlight the important role played by poorly understood energy loss mechanisms and propose a simple Ansatz which tackles this problem in the context of an extended velocity-dependent one-scale model. We find a general procedure to determine all the scaling solutions admitted by a specific string model and study their stability, enabling a detailed comparison with future numerical simulations. A simpler comparison with previous Goto-Nambu simulations supports earlier evidence that scaling is easier to achieve in the matter era than in the radiation era. In addition, we also find that the requirement that a scaling regime be stable seems to notably constrain the allowed range of energy loss parameters.

Measurements of Long-Lived Trace Gases from Commercial Aircraft Platforms: Development of Instrumentation

NASA Technical Reports Server (NTRS)

2002-01-01

The upper troposphere (6-12 km altitude) is a poorly understood and highly vulnerable region of the atmosphere. It is important because many trace species, including ozone, have their greatest impact as greenhouse (infrared-absorbing) gases in this region. The addition of relatively small amounts of anthropogenic chemicals, such as nitrogen oxides, can have a dramatic effect on the abundance of ozone. Some of these pollutants are deposited directly, e.g., by aircraft, while others are transported in. The primary goal of this project was to measure several chemical compounds in the upper troposphere that will help us to understand how air is to transported to that part of the atmosphere; that is, does it come down from the stratosphere, does it rise from the surface via convection, and so on. To obtain adequate sampling to accomplish this goal, we proposed to make measurements from revenue aircraft during normal flight operations.

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

Chen, Wei; Rosser, Ethan W.; Zhang, Di

Hydrogen polysulfides (H 2S n, n>1) have been recently suggested to be the actual signalling molecules that involved in sulfur-related redox biology. However the exact mechanisms of H 2S n are still poorly understood and a major hurdle in this field is the lack of reliable and convenient methods for H 2S n detection. In this work we report a unique ring-opening reaction of N-sulfonylaziridine by Na 2S 2 under mild conditions. Based on this reaction a novel H 2S n-specific fluorescent probe (AP) was developed. The probe showed high sensitivity and selectivity for H 2S n. Notably, the fluorescentmore » turn-on product, i.e. compound 1, exhibited excellent two-photon photophysical properties and a large Stokes shift. Moreover, the high solid state luminescent efficiency of compound 1 makes it a potential candidate for organic emitters and solid-state lighting devices.« less

The mechanical response of talin

NASA Astrophysics Data System (ADS)

Yao, Mingxi; Goult, Benjamin T.; Klapholz, Benjamin; Hu, Xian; Toseland, Christopher P.; Guo, Yingjian; Cong, Peiwen; Sheetz, Michael P.; Yan, Jie

2016-07-01

Talin, a force-bearing cytoplasmic adapter essential for integrin-mediated cell adhesion, links the actin cytoskeleton to integrin-based cell-extracellular matrix adhesions at the plasma membrane. Its C-terminal rod domain, which contains 13 helical bundles, plays important roles in mechanosensing during cell adhesion and spreading. However, how the structural stability and transition kinetics of the 13 helical bundles of talin are utilized in the diverse talin-dependent mechanosensing processes remains poorly understood. Here we report the force-dependent unfolding and refolding kinetics of all talin rod domains. Using experimentally determined kinetics parameters, we determined the dynamics of force fluctuation during stretching of talin under physiologically relevant pulling speeds and experimentally measured extension fluctuation trajectories. Our results reveal that force-dependent stochastic unfolding and refolding of talin rod domains make talin a very effective force buffer that sets a physiological force range of only a few pNs in the talin-mediated force transmission pathway.

Cutting‐edge endonasal surgical approaches to thyroid ophthalmopathy

PubMed Central

Tyler, Matthew A.; Zhang, Caroline C.; Saini, Alok T.

2018-01-01

Objective Thyroid orbitopathy is a poorly understood extrathyroidal manifestation of Graves' disease that can cause disfiguring proptosis and vision loss. Orbital decompression surgery for Graves' orbitopathy (GO) can address both cosmetic and visual sequelae of this autoimmune condition. Endonasal endoscopic orbital decompression provides unmatched visualization and access to inferomedial orbital wall and orbital apex. This review examines the state of the art approaches employed in endonasal endoscopic orbital decompression for GO. Methods Review of literature evaluating novel surgical maneuvers for GO. Results Studies examining the efficacy of endonasal endoscopic orbital decompression are heterogenous and retrospective in design; however, they reveal this approach to be a safe and effective technique in the management of GO. Conclusion Subtle variations in endoscopic techniques significantly affect postsurgical outcomes and can be tailored to the specific clinical indication in GO making endonasal endoscopic decompression the most versatile approach available. Level of Evidence NA. PMID:29721541

Peptidomic analysis reveals proteolytic activity of kefir microorganisms on bovine milk proteins

PubMed Central

Dallas, David C.; Citerne, Florine; Tian, Tian; Silva, Vitor L. M.; Kalanetra, Karen M.; Frese, Steven A.; Robinson, Randall C.; Mills, David A.; Barile, Daniela

2015-01-01

Scope The microorganisms that make up kefir grains are well known for lactose fermentation, but the extent to which they hydrolyze and consume milk proteins remains poorly understood. Peptidomics technologies were used to examine the proteolytic activity of kefir grains on bovine milk proteins. Methods and results Gel electrophoresis revealed substantial digestion of milk proteins by kefir grains, with mass spectrometric analysis showing the release of 609 protein fragments and alteration of the abundance of >1,500 peptides that derived from 27 milk proteins. Kefir contained 25 peptides identified from the literature as having biological activity, including those with antihypertensive, antimicrobial, immunomodulatory, opioid and anti-oxidative functions. 16S rRNA and shotgun metagenomic sequencing identified the principle taxa in the culture as Lactobacillus species. Conclusion The model kefir sample contained thousands of protein fragments released in part by kefir microorganisms and in part by native milk proteases. PMID:26616950

Reading Level and Comprehension of Research Consent Forms: An Integrative Review.

PubMed

Foe, Gabriella; Larson, Elaine L

2016-02-01

Consent forms continue to be at a higher reading level than the recommended sixth to eighth grade, making it difficult for participants to comprehend information before enrolling in research. To assess and address the extent of the problem regarding the level of literacy of consent forms and update previously published reports, we conducted an integrative literature review of English language research published between January 1, 2000, and December 31, 2013; 35 descriptive and eight intervention studies met inclusion criteria. Results confirmed that developing forms at eighth-grade level was attainable though not practiced. It was found that risks of participation was the section most poorly understood. There was also a lack of consensus regarding the most effective method to increase comprehension. Further research using standardized tools is needed to determine the best approach for improving consent forms and processes. © The Author(s) 2016.

Functional specificity of a Hox protein mediated by the recognition of minor groove structure.

PubMed

Joshi, Rohit; Passner, Jonathan M; Rohs, Remo; Jain, Rinku; Sosinsky, Alona; Crickmore, Michael A; Jacob, Vinitha; Aggarwal, Aneel K; Honig, Barry; Mann, Richard S

2007-11-02

The recognition of specific DNA-binding sites by transcription factors is a critical yet poorly understood step in the control of gene expression. Members of the Hox family of transcription factors bind DNA by making nearly identical major groove contacts via the recognition helices of their homeodomains. In vivo specificity, however, often depends on extended and unstructured regions that link Hox homeodomains to a DNA-bound cofactor, Extradenticle (Exd). Using a combination of structure determination, computational analysis, and in vitro and in vivo assays, we show that Hox proteins recognize specific Hox-Exd binding sites via residues located in these extended regions that insert into the minor groove but only when presented with the correct DNA sequence. Our results suggest that these residues, which are conserved in a paralog-specific manner, confer specificity by recognizing a sequence-dependent DNA structure instead of directly reading a specific DNA sequence.

Dorsal hippocampus contributes to model-based planning.

PubMed

Miller, Kevin J; Botvinick, Matthew M; Brody, Carlos D

2017-09-01

Planning can be defined as action selection that leverages an internal model of the outcomes likely to follow each possible action. Its neural mechanisms remain poorly understood. Here we adapt recent advances from human research for rats, presenting for the first time an animal task that produces many trials of planned behavior per session, making multitrial rodent experimental tools available to study planning. We use part of this toolkit to address a perennially controversial issue in planning: the role of the dorsal hippocampus. Although prospective hippocampal representations have been proposed to support planning, intact planning in animals with damaged hippocampi has been repeatedly observed. Combining formal algorithmic behavioral analysis with muscimol inactivation, we provide causal evidence directly linking dorsal hippocampus with planning behavior. Our results and methods open the door to new and more detailed investigations of the neural mechanisms of planning in the hippocampus and throughout the brain.

Neural Substrates of Counterfactual Emotions After Risky Decisions in Late Adolescents and Young Adults.

PubMed

Rodrigo, María José; Padrón, Iván; de Vega, Manuel; Ferstl, Evelyn

2018-03-01

Adolescents' neural substrates of emotional reactions to the consequences of risky decisions are poorly understood. In this functional magnetic resonance imaging study, 30 late adolescents and 30 young adults made risky and neutral decisions in social scenarios and received valenced outcomes. Negative outcomes in risky decisions eliciting regret, as compared with negative outcomes in neutral decisions eliciting disappointment, activated executive control (orbitofrontal cortex) and self-relevance regions (middle temporal gyrus [MTG], posterior cingulate cortex, and precuneus) for both age groups. Young adults showed more activation than adolescents in regret and disappointment as compared with relief and elation conditions in the avoidance (insula), action monitoring (inferior frontal gyrus, pre-SMA, and caudate), and social-cognition regions (superior temporal sulcus and MTG). These late socio-emotional developments may pave the way for more adaptive decision-making behavior in social contexts. © 2018 Society for Research on Adolescence.

Astronomers' Race to Test Relativity, 1911-1930

NASA Astrophysics Data System (ADS)

Crelinsten, Jeffrey

2006-11-01

Einstein's theory of relativity changed our notions of space and time and has dramatically altered the way we look at the universe and our place in it. Yet to this day a working knowledge of the theory is beyond most people. In today's popular culture, Einstein is a remote, loveable genius and his theory is incomprehensible. While Einstein's theory ultimately laid the foundation for modern studies of the universe, it took a long time to be accepted. Between 1905 and 1930, relativity was poorly understood and Einstein worked hard to try to make it more accessible to scientists and scientifically literate laypeople. Its acceptance was largely due to the astronomy community, which undertook precise measurements to test Einstein's astronomical predictions. How astronomers approached the ``Einstein problem'' in these early years and how the public reacted to what they reported helped to shape attitudes we hold today about Einstein and his ideas.

The psychology and neuroscience of curiosity

PubMed Central

Kidd, Celeste; Hayden, Benjamin Y.

2015-01-01

SUMMARY Curiosity is a basic element of our cognition, yet its biological function, mechanisms, and neural underpinning remain poorly understood. It is nonetheless a motivator for learning, influential in decision-making, and crucial for healthy development. One factor limiting our understanding of it is the lack of a widely agreed upon delineation of what is and is not curiosity; another factor is the dearth of standardized laboratory tasks that manipulate curiosity in the lab. Despite these barriers, recent years have seen a major growth of interest in both the neuroscience and psychology of curiosity. In this Perspective, we advocate for the importance of the field, provide a selective overview of its current state, and describe tasks that are used to study curiosity and information-seeking. We propose that, rather than worry about defining curiosity, it is more helpful to consider the motivations for information-seeking behavior and to study it in its ethological context. PMID:26539887

The Psychology and Neuroscience of Curiosity.

PubMed

Kidd, Celeste; Hayden, Benjamin Y

2015-11-04

Curiosity is a basic element of our cognition, but its biological function, mechanisms, and neural underpinning remain poorly understood. It is nonetheless a motivator for learning, influential in decision-making, and crucial for healthy development. One factor limiting our understanding of it is the lack of a widely agreed upon delineation of what is and is not curiosity. Another factor is the dearth of standardized laboratory tasks that manipulate curiosity in the lab. Despite these barriers, recent years have seen a major growth of interest in both the neuroscience and psychology of curiosity. In this Perspective, we advocate for the importance of the field, provide a selective overview of its current state, and describe tasks that are used to study curiosity and information-seeking. We propose that, rather than worry about defining curiosity, it is more helpful to consider the motivations for information-seeking behavior and to study it in its ethological context. Copyright © 2015 Elsevier Inc. All rights reserved.

Striatal BOLD Response Reflects the Impact of Herd Information on Financial Decisions

PubMed Central

Burke, Christopher J.; Tobler, Philippe N.; Schultz, Wolfram; Baddeley, Michelle

2010-01-01

Like other species, humans are sensitive to the decisions and actions of conspecifics, which can lead to herd behavior and undesirable outcomes such as stock market bubbles and bank runs. However, how the brain processes this socially derived influence is only poorly understood. Using functional magnetic resonance imaging (fMRI), we scanned participants as they made decisions on whether to buy stocks after observing others’ buying decisions. We demonstrate that activity in the ventral striatum, an area heavily implicated in reward processing, tracked the degree of influence on participants’ decisions arising from the observation of other peoples’ decisions. The signal did not track non-human, non-social control decisions. These findings lend weight to the notion that the ventral striatum is involved in the processing of complex social aspects of decision making and identify a possible neural basis for herd behavior. PMID:20589242

The Effects of Performance Fatigability on Postural Control and Rehabilitation in the Older Patient

PubMed Central

Hassan, Mahdi; Bugnariu, Nicoleta

2016-01-01

Fatigue is common in older adults and has a significant effect on quality of life. Despite the high prevalence of fatigue in older individuals, several aspects are poorly understood. It is important to differentiate subjective fatigue complaints from fatigability of motor performance because the two are independent constructs with potentially distinct consequences on mobility. Performance fatigability is the magnitude of change in a performance criterion over a given time of task performance. Performance fatigability is a compulsory element of any strength training program, yet strength training is an important component of rehabilitation programs for older adults. The consequences of fatigability for older adults suggest that acute exercise of various types may result in acute impairments in postural control. The effects of performance fatigability on postural control in older adults are evaluated here to aid the rehabilitation clinician in making recommendations for evaluation of fall risks and exercise prescription. PMID:28154794

The Effects of Performance Fatigability on Postural Control and Rehabilitation in the Older Patient.

PubMed

Papa, Evan V; Hassan, Mahdi; Bugnariu, Nicoleta

2016-09-01

Fatigue is common in older adults and has a significant effect on quality of life. Despite the high prevalence of fatigue in older individuals, several aspects are poorly understood. It is important to differentiate subjective fatigue complaints from fatigability of motor performance because the two are independent constructs with potentially distinct consequences on mobility. Performance fatigability is the magnitude of change in a performance criterion over a given time of task performance. Performance fatigability is a compulsory element of any strength training program, yet strength training is an important component of rehabilitation programs for older adults. The consequences of fatigability for older adults suggest that acute exercise of various types may result in acute impairments in postural control. The effects of performance fatigability on postural control in older adults are evaluated here to aid the rehabilitation clinician in making recommendations for evaluation of fall risks and exercise prescription.

Meaning-making in the aftermath of sudden infant death syndrome.

PubMed

Krueger, Guenther

2006-09-01

The reconstruction of meaning in the aftermath of sudden infant death syndrome (SIDS) is part of the grieving process but has to date been poorly understood. Earlier theorists including Freud, Bowlby and Kübler-Ross provided a foundation for what occurs during this time using stage theories. More recent researchers, often using qualitative techniques, have provided a more complex and expanded view that enhances our knowledge of meaning reconstruction following infant loss. This overview of representative contemporary authors compares and contrasts them with the longstanding models that are being supplanted within the emerging field of thanatology. Understanding parental reactions within this new framework can help healthcare professionals in dealing with those affected by SIDS and provide a more empathic and sensitive approach to individual differences. Parents' own accounts of their post-SIDS experience are consistent with these newer theories. Comprehending how parents cope and reconstruct their lives is an important element in providing appropriate psychological support services.

The yeast transcription elongation factor Spt4/5 is a sequence‐specific RNA binding protein

PubMed Central

Blythe, Amanda J.; Yazar‐Klosinski, Berra; Webster, Michael W.; Chen, Eefei; Vandevenne, Marylène; Bendak, Katerina; Mackay, Joel P.; Hartzog, Grant A.

2016-01-01

Abstract The heterodimeric transcription elongation factor Spt4/Spt5 (Spt4/5) tightly associates with RNAPII to regulate both transcriptional elongation and co‐transcriptional pre‐mRNA processing; however, the mechanisms by which Spt4/5 acts are poorly understood. Recent studies of the human and Drosophila Spt4/5 complexes indicate that they can bind nucleic acids in vitro. We demonstrate here that yeast Spt4/5 can bind in a sequence‐specific manner to single stranded RNA containing AAN repeats. Furthermore, we show that the major protein determinants for RNA‐binding are Spt4 together with the NGN domain of Spt5 and that the KOW domains are not required for RNA recognition. These findings attribute a new function to a domain of Spt4/5 that associates directly with RNAPII, making significant steps towards elucidating the mechanism behind transcriptional control by Spt4/5. PMID:27376968

The alignment of molecular cloud magnetic fields with the spiral arms in M33.

PubMed

Li, Hua-bai; Henning, Thomas

2011-11-16

The formation of molecular clouds, which serve as stellar nurseries in galaxies, is poorly understood. A class of cloud formation models suggests that a large-scale galactic magnetic field is irrelevant at the scale of individual clouds, because the turbulence and rotation of a cloud may randomize the orientation of its magnetic field. Alternatively, galactic fields could be strong enough to impose their direction upon individual clouds, thereby regulating cloud accumulation and fragmentation, and affecting the rate and efficiency of star formation. Our location in the disk of the Galaxy makes an assessment of the situation difficult. Here we report observations of the magnetic field orientation of six giant molecular cloud complexes in the nearby, almost face-on, galaxy M33. The fields are aligned with the spiral arms, suggesting that the large-scale field in M33 anchors the clouds. ©2011 Macmillan Publishers Limited. All rights reserved

Current challenges in organic photovoltaic solar energy conversion.

PubMed

Schlenker, Cody W; Thompson, Mark E

2012-01-01

Over the last 10 years, significant interest in utilizing conjugated organic molecules for solid-state solar to electric conversion has produced rapid improvement in device efficiencies. Organic photovoltaic (OPV) devices are attractive for their compatibility with low-cost processing techniques and thin-film applicability to flexible and conformal applications. However, many of the processes that lead to power losses in these systems still remain poorly understood, posing a significant challenge for the future efficiency improvements required to make these devices an attractive solar technology. While semiconductor band models have been employed to describe OPV operation, a more appropriate molecular picture of the pertinent processes is beginning to emerge. This chapter presents mechanisms of OPV device operation, based on the bound molecular nature of the involved transient species. With the intention to underscore the importance of considering both thermodynamic and kinetic factors, recent progress in elucidating molecular characteristics that dictate photovoltage losses in heterojunction organic photovoltaics is also discussed.

Paleo-tribology: development of wear measurement techniques and a three-dimensional model revealing how grinding dentitions self-wear to enable functionality

NASA Astrophysics Data System (ADS)

Erickson, Gregory M.; Sidebottom, Mark A.; Curry, John F.; Kay, David Ian; Kuhn-Hendricks, Stephen; Norell, Mark A.; Sawyer, W. Gregory; Krick, Brandon A.

2016-06-01

In most mammals and a rare few reptilian lineages the evolution of precise dental occlusion led to the capacity to form functional chewing surfaces due to pressures generated while feeding. The complex dental architectures of such teeth and the biomechanics of their self-wearing nature are poorly understood. Our research team composed of paleontologists, evolutionary biologists, and engineers have developed a protocol to: (1) determine the histological make-up of grinding dentitions in extant and fossil taxa; (2) ascertain wear-relevant material properties of the tissues; (3) determine how those properties relate to inter-tissue-biomechanics leading the dental functionality using a three-dimensional Archard’s wear model developed specifically for dental applications; (4) analyze those data in phylogenetic contexts to infer evolutionary patterns as they relate to feeding. Finally we discuss industrial applications that are emerging from our paleontologically-inspired research.

3D Protein Dynamics in the Cell Nucleus.

PubMed

Singh, Anand P; Galland, Rémi; Finch-Edmondson, Megan L; Grenci, Gianluca; Sibarita, Jean-Baptiste; Studer, Vincent; Viasnoff, Virgile; Saunders, Timothy E

2017-01-10

The three-dimensional (3D) architecture of the cell nucleus plays an important role in protein dynamics and in regulating gene expression. However, protein dynamics within the 3D nucleus are poorly understood. Here, we present, to our knowledge, a novel combination of 1) single-objective based light-sheet microscopy, 2) photoconvertible proteins, and 3) fluorescence correlation microscopy, to quantitatively measure 3D protein dynamics in the nucleus. We are able to acquire >3400 autocorrelation functions at multiple spatial positions within a nucleus, without significant photobleaching, allowing us to make reliable estimates of diffusion dynamics. Using this tool, we demonstrate spatial heterogeneity in Polymerase II dynamics in live U2OS cells. Further, we provide detailed measurements of human-Yes-associated protein diffusion dynamics in a human gastric cancer epithelial cell line. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Learning Collaboratives: Insights And A New Taxonomy From AHRQ's Two Decades Of Experience.

PubMed

Nix, Mary; McNamara, Peggy; Genevro, Janice; Vargas, Natalia; Mistry, Kamila; Fournier, Alaina; Shofer, Margie; Lomotan, Edwin; Miller, Therese; Ricciardi, Richard; Bierman, Arlene S

2018-02-01

Learning collaboratives are increasingly used as mechanisms to support and hasten the diffusion and implementation of innovation, clinical evidence, and effective models of care. Factors contributing to the collaboratives' success or failure are poorly understood. The Agency for Healthcare Research and Quality (AHRQ) has sponsored collaboratives for nearly two decades to support improvements in health care quality and value by accelerating the diffusion and implementation of innovation. We examined AHRQ's experience with these collaboratives to characterize their attributes, identify factors that might contribute to their success or failure, and assess the challenges they encountered. Building on the literature and insights from AHRQ's experience, we propose a taxonomy that can offer guidance to decision makers and funders about the factors they should consider in developing collaboratives and planning their evaluation, as well as to researchers who seek to conduct research that will ultimately help decision makers make better investments in diffusing innovation and evidence.

Regional climatic warming drives long-term community changes of British marine fish.

PubMed Central

Genner, Martin J.; Sims, David W.; Wearmouth, Victoria J.; Southall, Emily J.; Southward, Alan J.; Henderson, Peter A.; Hawkins, Stephen J.

2004-01-01

Climatic change has been implicated as the cause of abundance fluctuations in marine fish populations worldwide, but the effects on whole communities are poorly understood. We examined the effects of regional climatic change on two fish assemblages using independent datasets from inshore marine (English Channel, 1913-2002) and estuarine environments (Bristol Channel, 1981-2001). Our results show that climatic change has had dramatic effects on community composition. Each assemblage contained a subset of dominant species whose abundances were strongly linked to annual mean sea-surface temperature. Species' latitudinal ranges were not good predictors of species-level responses, however, and the same species did not show congruent trends between sites. This suggests that within a region, populations of the same species may respond differently to climatic change, possibly owing to additional local environmental determinants, interspecific ecological interactions and dispersal capacity. This will make species-level responses difficult to predict within geographically differentiated communities. PMID:15156925

Unexpected rewards induce dopamine-dependent positive emotion-like state changes in bumblebees.

PubMed

Perry, Clint J; Baciadonna, Luigi; Chittka, Lars

2016-09-30

Whether invertebrates exhibit positive emotion-like states and what mechanisms underlie such states remain poorly understood. We demonstrate that bumblebees exhibit dopamine-dependent positive emotion-like states across behavioral contexts. After training with one rewarding and one unrewarding cue, bees that received pretest sucrose responded in a positive manner toward ambiguous cues. In a second experiment, pretest consumption of sucrose solution resulted in a shorter time to reinitiate foraging after a simulated predator attack. These behavioral changes were abolished with topical application of the dopamine antagonist fluphenazine. Further experiments established that pretest sucrose does not simply cause bees to become more exploratory. Our findings present a new opportunity for understanding the fundamental neural elements of emotions and may alter the view of how emotion states affect decision-making in animals. Copyright © 2016, American Association for the Advancement of Science.

Peptidomic analysis reveals proteolytic activity of kefir microorganisms on bovine milk proteins.

PubMed

Dallas, David C; Citerne, Florine; Tian, Tian; Silva, Vitor L M; Kalanetra, Karen M; Frese, Steven A; Robinson, Randall C; Mills, David A; Barile, Daniela

2016-04-15

The microorganisms that make up kefir grains are well known for lactose fermentation, but the extent to which they hydrolyze and consume milk proteins remains poorly understood. Peptidomics technologies were used to examine the proteolytic activity of kefir grains on bovine milk proteins. Gel electrophoresis revealed substantial digestion of milk proteins by kefir grains, with mass spectrometric analysis showing the release of 609 protein fragments and alteration of the abundance of >1500 peptides that derived from 27 milk proteins. Kefir contained 25 peptides identified from the literature as having biological activity, including those with antihypertensive, antimicrobial, immunomodulatory, opioid and anti-oxidative functions. 16S rRNA and shotgun metagenomic sequencing identified the principle taxa in the culture as Lactobacillus species. The model kefir sample contained thousands of protein fragments released in part by kefir microorganisms and in part by native milk proteases. Copyright © 2015 Elsevier Ltd. All rights reserved.

76 FR 61379 - Final Recovery Plan, Bexar County Karst Invertebrates

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-04

... 200, Austin, TX (512-490-0057 ext. 223). FOR FURTHER INFORMATION CONTACT: Adam Zerrenner, at the above... poorly understood, recovery is also dependant on incorporating research findings into adaptive management...

Fine-scale landscape genetics of the American badger (Taxidea taxus): disentangling landscape effects and sampling artifacts in a poorly understood species

PubMed Central

Kierepka, E M; Latch, E K

2016-01-01

Landscape genetics is a powerful tool for conservation because it identifies landscape features that are important for maintaining genetic connectivity between populations within heterogeneous landscapes. However, using landscape genetics in poorly understood species presents a number of challenges, namely, limited life history information for the focal population and spatially biased sampling. Both obstacles can reduce power in statistics, particularly in individual-based studies. In this study, we genotyped 233 American badgers in Wisconsin at 12 microsatellite loci to identify alternative statistical approaches that can be applied to poorly understood species in an individual-based framework. Badgers are protected in Wisconsin owing to an overall lack in life history information, so our study utilized partial redundancy analysis (RDA) and spatially lagged regressions to quantify how three landscape factors (Wisconsin River, Ecoregions and land cover) impacted gene flow. We also performed simulations to quantify errors created by spatially biased sampling. Statistical analyses first found that geographic distance was an important influence on gene flow, mainly driven by fine-scale positive spatial autocorrelations. After controlling for geographic distance, both RDA and regressions found that Wisconsin River and Agriculture were correlated with genetic differentiation. However, only Agriculture had an acceptable type I error rate (3–5%) to be considered biologically relevant. Collectively, this study highlights the benefits of combining robust statistics and error assessment via simulations and provides a method for hypothesis testing in individual-based landscape genetics. PMID:26243136

Biodiversity and ecosystem function in species-poor communities: community structure and leaf litter breakdown in a Pacific island stream

Treesearch

Jonathan P. Benstead; James G. March; Catherine M. Pringle; Katherine C. Ewel; John W. Short

2009-01-01

Pacific island stream communities are species-poor because of the effects of extreme geographic isolation on colonization rates of taxa common to continental regions. The effects of such low species richness on stream ecosystem function are not well understood. Here, we provide data on community structure and leaf litter breakdown rate in a virtually pristine stream on...

Private health insurance: implications for developing countries.

PubMed Central

Sekhri, Neelam; Savedoff, William

2005-01-01

Private health insurance is playing an increasing role in both high- and low-income countries, yet is poorly understood by researchers and policy-makers. This paper shows that the distinction between private and public health insurance is often exaggerated since well regulated private insurance markets share many features with public insurance systems. It notes that private health insurance preceded many modern social insurance systems in western Europe, allowing these countries to develop the mechanisms, institutions and capacities that subsequently made it possible to provide universal access to health care. We also review international experiences with private insurance, demonstrating that its role is not restricted to any particular region or level of national income. The seven countries that finance more than 20% of their health care via private health insurance are Brazil, Chile, Namibia, South Africa, the United States, Uruguay and Zimbabwe. In each case, private health insurance provides primary financial protection for workers and their families while public health-care funds are targeted to programmes covering poor and vulnerable populations. We make recommendations for policy in developing countries, arguing that private health insurance cannot be ignored. Instead, it can be harnessed to serve the public interest if governments implement effective regulations and focus public funds on programmes for those who are poor and vulnerable. It can also be used as a transitional form of health insurance to develop experience with insurance institutions while the public sector increases its own capacity to manage and finance health-care coverage. PMID:15744405

Private health insurance: implications for developing countries.

PubMed

Sekhri, Neelam; Savedoff, William

2005-02-01

Private health insurance is playing an increasing role in both high- and low-income countries, yet is poorly understood by researchers and policy-makers. This paper shows that the distinction between private and public health insurance is often exaggerated since well regulated private insurance markets share many features with public insurance systems. It notes that private health insurance preceded many modern social insurance systems in western Europe, allowing these countries to develop the mechanisms, institutions and capacities that subsequently made it possible to provide universal access to health care. We also review international experiences with private insurance, demonstrating that its role is not restricted to any particular region or level of national income. The seven countries that finance more than 20% of their health care via private health insurance are Brazil, Chile, Namibia, South Africa, the United States, Uruguay and Zimbabwe. In each case, private health insurance provides primary financial protection for workers and their families while public health-care funds are targeted to programmes covering poor and vulnerable populations. We make recommendations for policy in developing countries, arguing that private health insurance cannot be ignored. Instead, it can be harnessed to serve the public interest if governments implement effective regulations and focus public funds on programmes for those who are poor and vulnerable. It can also be used as a transitional form of health insurance to develop experience with insurance institutions while the public sector increases its own capacity to manage and finance health-care coverage.

Poor supplementary motor area activation differentiates auditory verbal hallucination from imagining the hallucination☆

PubMed Central

Raij, Tuukka T.; Riekki, Tapani J.J.

2012-01-01

Neuronal underpinnings of auditory verbal hallucination remain poorly understood. One suggested mechanism is brain activation that is similar to verbal imagery but occurs without the proper activation of the neuronal systems that are required to tag the origins of verbal imagery in one's mind. Such neuronal systems involve the supplementary motor area. The supplementary motor area has been associated with awareness of intention to make a hand movement, but whether this region is related to the sense of ownership of one's verbal thought remains poorly known. We hypothesized that the supplementary motor area is related to the distinction between one's own mental processing (auditory verbal imagery) and similar processing that is attributed to non-self author (auditory verbal hallucination). To test this hypothesis, we asked patients to signal the onset and offset of their auditory verbal hallucinations during functional magnetic resonance imaging. During non-hallucination periods, we asked the same patients to imagine the hallucination they had previously experienced. In addition, healthy control subjects signaled the onset and offset of self-paced imagery of similar voices. Both hallucinations and the imagery of hallucinations were associated with similar activation strengths of the fronto-temporal language-related circuitries, but the supplementary motor area was activated more strongly during the imagery than during hallucination. These findings suggest that auditory verbal hallucination resembles verbal imagery in language processing, but without the involvement of the supplementary motor area, which may subserve the sense of ownership of one's own verbal imagery. PMID:24179739

The public's belief about biology.

PubMed

Wolpert, L

2007-02-01

This short review is concerned with a topic that has been neglected and is still very poorly understood: what the general public think and believe about biology (including health and medicine, and bioethics), and, in particular, about biotechnology.

A Production Function Approach to Regional Environmental-Economic Assessments

EPA Science Inventory

Numerous difficulties await those creating regional-scale environmental assessments, from data having inconsistent spatial or temporal scales to poorly understood environmental processes and indicators. Including socioeconomic variables further complicates the situation. In place...

Elucidating Poor Decision-Making in a Rat Gambling Task

PubMed Central

Seriès, Peggy; Marchand, Alain R.; Dellu-Hagedorn, Françoise

2013-01-01

Although poor decision-making is a hallmark of psychiatric conditions such as attention deficit/hyperactivity disorder, pathological gambling or substance abuse, a fraction of healthy individuals exhibit similar poor decision-making performances in everyday life and specific laboratory tasks such as the Iowa Gambling Task. These particular individuals may provide information on risk factors or common endophenotypes of these mental disorders. In a rodent version of the Iowa gambling task – the Rat Gambling Task (RGT), we identified a population of poor decision makers, and assessed how these rats scored for several behavioral traits relevant to executive disorders: risk taking, reward seeking, behavioral inflexibility, and several aspects of impulsivity. First, we found that poor decision-making could not be well predicted by single behavioral and cognitive characteristics when considered separately. By contrast, a combination of independent traits in the same individual, namely risk taking, reward seeking, behavioral inflexibility, as well as motor impulsivity, was highly predictive of poor decision-making. Second, using a reinforcement-learning model of the RGT, we confirmed that only the combination of extreme scores on these traits could induce maladaptive decision-making. Third, the model suggested that a combination of these behavioral traits results in an inaccurate representation of rewards and penalties and inefficient learning of the environment. Poor decision-making appears as a consequence of the over-valuation of high-reward-high-risk options in the task. Such a specific psychological profile could greatly impair clinically healthy individuals in decision-making tasks and may predispose to mental disorders with similar symptoms. PMID:24339988

Elucidating poor decision-making in a rat gambling task.

PubMed

Rivalan, Marion; Valton, Vincent; Seriès, Peggy; Marchand, Alain R; Dellu-Hagedorn, Françoise

2013-01-01

Although poor decision-making is a hallmark of psychiatric conditions such as attention deficit/hyperactivity disorder, pathological gambling or substance abuse, a fraction of healthy individuals exhibit similar poor decision-making performances in everyday life and specific laboratory tasks such as the Iowa Gambling Task. These particular individuals may provide information on risk factors or common endophenotypes of these mental disorders. In a rodent version of the Iowa gambling task--the Rat Gambling Task (RGT), we identified a population of poor decision makers, and assessed how these rats scored for several behavioral traits relevant to executive disorders: risk taking, reward seeking, behavioral inflexibility, and several aspects of impulsivity. First, we found that poor decision-making could not be well predicted by single behavioral and cognitive characteristics when considered separately. By contrast, a combination of independent traits in the same individual, namely risk taking, reward seeking, behavioral inflexibility, as well as motor impulsivity, was highly predictive of poor decision-making. Second, using a reinforcement-learning model of the RGT, we confirmed that only the combination of extreme scores on these traits could induce maladaptive decision-making. Third, the model suggested that a combination of these behavioral traits results in an inaccurate representation of rewards and penalties and inefficient learning of the environment. Poor decision-making appears as a consequence of the over-valuation of high-reward-high-risk options in the task. Such a specific psychological profile could greatly impair clinically healthy individuals in decision-making tasks and may predispose to mental disorders with similar symptoms.

Clinical Trials, Data Protection and Patient Empowerment in the Era of the New EU Regulations.

PubMed

Negrouk, Anastassia; Horgan, Denis; Gorini, Alessandra; Cutica, Ilaria; Leyens, Lada; Schee genannt Halfmann, Sebastian; Pravettoni, Gabriella

2015-01-01

Cancer clinical trials and, in general, cancer clinical research by definition need a multi-modality approach. It is not enough to discover and register new drugs. To get cancer under control requires us to perform complex clinical studies that integrate drugs, companion diagnostics, new or improved surgical procedures and new radiotherapy approaches as well as, most importantly, to integrate all available information. This includes biological material and, of increasing importance, large amounts of data using big data technologies. To personalise treatment, genetic data are more and more frequently used. Therefore, the general approach is holistic. Legislators, on the other hand, work in a silo mentality; the needs of clinical research are poorly understood, and legislation focuses on either health care or the commercialisation of a product, and not on clinical research. In the last 2 years the EU has drafted several major regulations touching on clinical trials, in vitro diagnostics, medical devices and data protection, all of which will impact clinical research, although the silo mentality makes the overall framework inconsistent and potentially highly damaging to the EU's capacity to make rapid progress in the field of personalised medicine. © 2015 S. Karger AG, Basel.

Mechano-logical model of C. elegans germ line suggests feedback on the cell cycle

PubMed Central

Atwell, Kathryn; Qin, Zhao; Gavaghan, David; Kugler, Hillel; Hubbard, E. Jane Albert; Osborne, James M.

2015-01-01

The Caenorhabditis elegans germ line is an outstanding model system in which to study the control of cell division and differentiation. Although many of the molecules that regulate germ cell proliferation and fate decisions have been identified, how these signals interact with cellular dynamics and physical forces within the gonad remains poorly understood. We therefore developed a dynamic, 3D in silico model of the C. elegans germ line, incorporating both the mechanical interactions between cells and the decision-making processes within cells. Our model successfully reproduces key features of the germ line during development and adulthood, including a reasonable ovulation rate, correct sperm count, and appropriate organization of the germ line into stably maintained zones. The model highlights a previously overlooked way in which germ cell pressure may influence gonadogenesis, and also predicts that adult germ cells might be subject to mechanical feedback on the cell cycle akin to contact inhibition. We provide experimental data consistent with the latter hypothesis. Finally, we present cell trajectories and ancestry recorded over the course of a simulation. The novel approaches and software described here link mechanics and cellular decision-making, and are applicable to modeling other developmental and stem cell systems. PMID:26428008

Blaming the helpers: the marginalization of teachers and parents of the urban poor.

PubMed

Farber, B A; Azar, S T

1999-10-01

The nature and origins of the current tendency toward disparaging parents and teachers of the urban poor are examined. It is suggested that the influence of parents and teachers must be understood in the context of multiple intervening variables. Several explanations are offered for the phenomenon of blame, including the fact that women constitute the great majority of teachers and are often the primary agents of parenting.

Any qualified provider: a qualitative case study of one community NHS Trust's response

PubMed Central

Walumbe, Jackie; Swinglehurst, Deborah; Shaw, Sara

2016-01-01

Objective To examine how those managing and providing community-based musculoskeletal (MSK) services have experienced recent policy allowing patients to choose any provider that meets certain quality standards from the National Health Service (NHS), private or voluntary sector. Design Intrinsic case study combining qualitative analysis of interviews and field notes. Setting An NHS Community Trust (the main providers of community health services in the NHS) in England, 2013–2014. Participants NHS Community Trust employees involved in delivering MSK services, including clinical staff and managerial staff in senior and mid-range positions. Findings Managers (n=4) and clinicians (n=4) working within MSK services understood and experienced the Any Qualified Provider (AQP) policy as involving: (1) a perceived trade-off between quality and cost in its implementation; (2) deskilling of MSK clinicians and erosion of professional values; and (3) a shift away from interprofessional collaboration and dialogue. These ways of making sense of AQP policy were associated with dissatisfaction with market-based health reforms. Conclusions AQP policy is poorly understood. Clinicians and managers perceive AQP as synonymous with competition and privatisation. From the perspective of clinicians providing MSK services, AQP, and related health policy reforms, tend, paradoxically, to drive down quality standards, supporting reconfiguration of services in which the complex, holistic nature of specialised MSK care may become marginalised by policy concerns about efficiency and cost. Our analysis indicates that the potential of AQP policy to increase quality of care is, at best, equivocal, and that any consideration of how AQP impacts on practice can only be understood by reference to a wider range of health policy reforms. PMID:26908521

Any qualified provider: a qualitative case study of one community NHS Trust's response.

PubMed

Walumbe, Jackie; Swinglehurst, Deborah; Shaw, Sara

2016-02-23

To examine how those managing and providing community-based musculoskeletal (MSK) services have experienced recent policy allowing patients to choose any provider that meets certain quality standards from the National Health Service (NHS), private or voluntary sector. Intrinsic case study combining qualitative analysis of interviews and field notes. An NHS Community Trust (the main providers of community health services in the NHS) in England, 2013-2014. NHS Community Trust employees involved in delivering MSK services, including clinical staff and managerial staff in senior and mid-range positions. Managers (n=4) and clinicians (n=4) working within MSK services understood and experienced the Any Qualified Provider (AQP) policy as involving: (1) a perceived trade-off between quality and cost in its implementation; (2) deskilling of MSK clinicians and erosion of professional values; and (3) a shift away from interprofessional collaboration and dialogue. These ways of making sense of AQP policy were associated with dissatisfaction with market-based health reforms. AQP policy is poorly understood. Clinicians and managers perceive AQP as synonymous with competition and privatisation. From the perspective of clinicians providing MSK services, AQP, and related health policy reforms, tend, paradoxically, to drive down quality standards, supporting reconfiguration of services in which the complex, holistic nature of specialised MSK care may become marginalised by policy concerns about efficiency and cost. Our analysis indicates that the potential of AQP policy to increase quality of care is, at best, equivocal, and that any consideration of how AQP impacts on practice can only be understood by reference to a wider range of health policy reforms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

PHYTOASSESSMENT OF ESTUARINE SEDIMENTS

EPA Science Inventory

Most sediment quality assessments and quality guidelines are based on the laboratory response of single animal species and benthic animal community composition. The role of plants in this hazard assessment process is poorly understood despite the fact that plant-dominated habitat...

FACTORS INFLUENCING LIGHT-INDUCED MORTALITY OF ENTEROCOCCI IN SEDIMENT SUSPENSIONS

EPA Science Inventory

Contamination of recreational waters by pathogenic microorganisms occurs through complex, poorly understood interactions involving variable microbial sources, hydrodynamic transport, arid microbial fate processes. Fecal indicator bacteria such as enterococci have been used to ass...

Plantation management intensity affects belowground carbon and nitrogen storage in northern California

Treesearch

K. J. McFarlane; S. H. Schoenholtz; R. F. Powers

2009-01-01

Belowground C and N storage is important in maintaining forestproductivity and to CO2 sequestration. How these pools respondto management is poorly understood. We investigated effectsof repeated applications of complete fertilizer and competing...

Predictive Models of Liver Cancer

EPA Science Inventory

Predictive models of chemical-induced liver cancer face the challenge of bridging causative molecular mechanisms to adverse clinical outcomes. The latent sequence of intervening events from chemical insult to toxicity are poorly understood because they span multiple levels of bio...

What Can Plasticity Contribute to Insect Responses to Climate Change?

PubMed

Sgrò, Carla M; Terblanche, John S; Hoffmann, Ary A

2016-01-01

Plastic responses figure prominently in discussions on insect adaptation to climate change. Here we review the different types of plastic responses and whether they contribute much to adaptation. Under climate change, plastic responses involving diapause are often critical for population persistence, but key diapause responses under dry and hot conditions remain poorly understood. Climate variability can impose large fitness costs on insects showing diapause and other life cycle responses, threatening population persistence. In response to stressful climatic conditions, insects also undergo ontogenetic changes including hardening and acclimation. Environmental conditions experienced across developmental stages or by prior generations can influence hardening and acclimation, although evidence for the latter remains weak. Costs and constraints influence patterns of plasticity across insect clades, but they are poorly understood within field contexts. Plastic responses and their evolution should be considered when predicting vulnerability to climate change-but meaningful empirical data lag behind theory.

Activity-Induced Remodeling of Olfactory Bulb Microcircuits Revealed by Monosynaptic Tracing

PubMed Central

Arenkiel, Benjamin R.; Hasegawa, Hiroshi; Yi, Jason J.; Larsen, Rylan S.; Wallace, Michael L.; Philpot, Benjamin D.; Wang, Fan; Ehlers, Michael D.

2011-01-01

The continued addition of new neurons to mature olfactory circuits represents a remarkable mode of cellular and structural brain plasticity. However, the anatomical configuration of newly established circuits, the types and numbers of neurons that form new synaptic connections, and the effect of sensory experience on synaptic connectivity in the olfactory bulb remain poorly understood. Using in vivo electroporation and monosynaptic tracing, we show that postnatal-born granule cells form synaptic connections with centrifugal inputs and mitral/tufted cells in the mouse olfactory bulb. In addition, newly born granule cells receive extensive input from local inhibitory short axon cells, a poorly understood cell population. The connectivity of short axon cells shows clustered organization, and their synaptic input onto newborn granule cells dramatically and selectively expands with odor stimulation. Our findings suggest that sensory experience promotes the synaptic integration of new neurons into cell type-specific olfactory circuits. PMID:22216277

The Multifactorial Epidemiology of Blackwater Fever.

PubMed

Shanks, G Dennis

2017-12-01

Blackwater fever is a massive hemolytic event usually occurring in the context of repeated falciparum malaria infections and intermittent quinine use. Its etiology is poorly understood, and it is rarely seen today. Historical epidemiological observations from the 20th century demonstrated variable patterns in prisoners in Andaman Islands, refugees in Macedonia, canal workers in Panama, expatriates in Rhodesia, and Second World War soldiers. Rates of blackwater fever per 1,000 malaria cases varied over two orders of magnitude. Islands, such as the Andaman Islands and New Guinea, had lower blackwater fever rates than continental areas. During the Second World War, blackwater fever rates in British soldiers in West Africa and Australian soldiers in New Guinea differed by a factor of 40 despite similar treatment regimens and falciparum malaria transmission risks. Blackwater fever is a complex interaction between host erythrocyte, falciparum malaria, and antimalarial drugs which remains poorly understood.

Differences in interfacial bond strengths of graphite fiber-epoxy resin composites

NASA Technical Reports Server (NTRS)

Needles, H. L.

1985-01-01

The effect of epoxy-size and degree of cure on the interfacial bonding of an epoxy-amine-graphite fiber composite system is examined. The role of the fiber-resin interface in determining the overall mechanical properties of composites is poorly understood. A good interfacial adhesive bond is required to achieve maximum stress transfer to the fibers in composites, but at the same time some form of energy absorbing interfacial interaction is needed to achieve high fracture toughening. The incompatibility of these two processes makes it important to understand the nature and basic factors involved at the fiber-resin interface as stress is applied. The mechanical properties including interlaminar shear values for graphite fiber-resin composites are low compared to glass and boron-resin composites. These differences have been attributed to poor fiber-matrix adhesion. Graphite fibers are commonly subjected to post-treatments including application of organic sizing in order to improve their compatibility with the resin matrix and to protect the fiber tow from damage during processing and lay-up. In such processes, sized graphite fiber tow is impregnated with epoxy resin and then layed-up i nto the appropriate configuration. Following an extended ambient temperature cure, the graphite-resin composite structure is cured at elevated temperature using a programmed temperature sequence to cure and then cool the product.

Continental-scale patterns of canopy tree composition and function across Amazonia.

PubMed

ter Steege, Hans; Pitman, Nigel C A; Phillips, Oliver L; Chave, Jerome; Sabatier, Daniel; Duque, Alvaro; Molino, Jean-François; Prévost, Marie-Françoise; Spichiger, Rodolphe; Castellanos, Hernán; von Hildebrand, Patricio; Vásquez, Rodolfo

2006-09-28

The world's greatest terrestrial stores of biodiversity and carbon are found in the forests of northern South America, where large-scale biogeographic patterns and processes have recently begun to be described. Seven of the nine countries with territory in the Amazon basin and the Guiana shield have carried out large-scale forest inventories, but such massive data sets have been little exploited by tropical plant ecologists. Although forest inventories often lack the species-level identifications favoured by tropical plant ecologists, their consistency of measurement and vast spatial coverage make them ideally suited for numerical analyses at large scales, and a valuable resource to describe the still poorly understood spatial variation of biomass, diversity, community composition and forest functioning across the South American tropics. Here we show, by using the seven forest inventories complemented with trait and inventory data collected elsewhere, two dominant gradients in tree composition and function across the Amazon, one paralleling a major gradient in soil fertility and the other paralleling a gradient in dry season length. The data set also indicates that the dominance of Fabaceae in the Guiana shield is not necessarily the result of root adaptations to poor soils (nodulation or ectomycorrhizal associations) but perhaps also the result of their remarkably high seed mass there as a potential adaptation to low rates of disturbance.

An Ethnographic Study of the Social Context of Migrant Health in the United States

PubMed Central

Holmes, Seth M

2006-01-01

Background Migrant workers in the United States have extremely poor health. This paper aims to identify ways in which the social context of migrant farm workers affects their health and health care. Methods and Findings This qualitative study employs participant observation and interviews on farms and in clinics throughout 15 months of migration with a group of indigenous Triqui Mexicans in the western US and Mexico. Study participants include more than 130 farm workers and 30 clinicians. Data are analyzed utilizing grounded theory, accompanied by theories of structural violence, symbolic violence, and the clinical gaze. The study reveals that farm working and housing conditions are organized according to ethnicity and citizenship. This hierarchy determines health disparities, with undocumented indigenous Mexicans having the worst health. Yet, each group is understood to deserve its place in the hierarchy, migrant farm workers often being blamed for their own sicknesses. Conclusions Structural racism and anti-immigrant practices determine the poor working conditions, living conditions, and health of migrant workers. Subtle racism serves to reduce awareness of this social context for all involved, including clinicians. The paper concludes with strategies toward improving migrant health in four areas: health disparities research, clinical interactions with migrant laborers, medical education, and policy making. PMID:17076567

Continental-scale patterns of canopy tree composition and function across Amazonia

NASA Astrophysics Data System (ADS)

Ter Steege, Hans; Pitman, Nigel C. A.; Phillips, Oliver L.; Chave, Jerome; Sabatier, Daniel; Duque, Alvaro; Molino, Jean-François; Prévost, Marie-Françoise; Spichiger, Rodolphe; Castellanos, Hernán; von Hildebrand, Patricio; Vásquez, Rodolfo

2006-09-01

The world's greatest terrestrial stores of biodiversity and carbon are found in the forests of northern South America, where large-scale biogeographic patterns and processes have recently begun to be described. Seven of the nine countries with territory in the Amazon basin and the Guiana shield have carried out large-scale forest inventories, but such massive data sets have been little exploited by tropical plant ecologists. Although forest inventories often lack the species-level identifications favoured by tropical plant ecologists, their consistency of measurement and vast spatial coverage make them ideally suited for numerical analyses at large scales, and a valuable resource to describe the still poorly understood spatial variation of biomass, diversity, community composition and forest functioning across the South American tropics. Here we show, by using the seven forest inventories complemented with trait and inventory data collected elsewhere, two dominant gradients in tree composition and function across the Amazon, one paralleling a major gradient in soil fertility and the other paralleling a gradient in dry season length. The data set also indicates that the dominance of Fabaceae in the Guiana shield is not necessarily the result of root adaptations to poor soils (nodulation or ectomycorrhizal associations) but perhaps also the result of their remarkably high seed mass there as a potential adaptation to low rates of disturbance.

Of all foods bread is the most noble: Carl von Linné (Carl Linneaus) on bread1

PubMed Central

Räsänen, Leena

2007-01-01

Carl von Linné was interested in dietetics, which in his time covered all aspects of a healthy life. As a utilitarian he understood the importance of private economy and paid attention to bread in many of his publications. Two texts, Ceres noverca arctoum and De pane diaetetico, were wholly devoted to bread and bread-making. Linné classified different types of bread, and described their nutritional value and health-related aspects, as well as milling, baking and storing, in detail. While discussing the food habits of social classes Linné accepted as a fact that the peasants and the poor should eat less tasty bread than the rich. The less palatable bread had, however, many nutritional and health advantages. Linné paid much attention to substitutes for grain to be used in times of famine, an important topic in eighteenth century Sweden. He regarded flour made of pine bark or water arum roots as excellent famine food, was enthusiastic about the new plant, maize, but considered potato only as a poor substitute for grain. Linné and his followers praised bread not only as the core component of diet, but also for its versatile role both in health and in disease.

Factors influencing nurses' judgements about self-neglect cases.

PubMed

Lauder, W; Ludwick, R; Zeller, R; Winchell, J

2006-06-01

From the perspective of the practising nurse self-neglect may best be understood in terms of a set of complex and often poorly defined clinical problems in which two key clinical issues are "how do I judge whether this person has the capacity to make decisions about their lifestyle?" and "do we need to treat this person using mental health legislation?" These are taxing questions as judging if a patient has the capacity to make decisions about their lifestyle choices is difficult for even the most experienced clinicians. Such determinations require nurses to form a judgement as to mental capacity of the patient. We do not know what patient characteristics and in what combination nurses use these when making these judgements. This factorial survey aimed to identify which patient characteristics influenced Registered Nurses' judgements on decision-making capacity and decisions on the use of interventions which require statutory interventions in cases of self-neglect. Judgements on decision-making capacity were overwhelmingly predicted by information of the patients' mental health status. Nurses place patients in one of three broad categories of no mental illness, minor mental illness and severe mental illness. This categorization appears to operate as a fast and frugal heuristic indicating that nurses may use mental status as a cognitive screen to work from in judging self-neglect. Although there is a correlation between the severity of mental illness and the capacity for making decisions they are not the same. This study shows the continued work that needs done in educating nurses not only about self-neglect but also about the role a patient's mental status may have in assessment of problems.

Dissociable roles for the basolateral amygdala and orbitofrontal cortex in decision-making under risk of punishment.

PubMed

Orsini, Caitlin A; Trotta, Rose T; Bizon, Jennifer L; Setlow, Barry

2015-01-28

Several neuropsychiatric disorders are associated with abnormal decision-making involving risk of punishment, but the neural basis of this association remains poorly understood. Altered activity in brain systems including the basolateral amygdala (BLA) and orbitofrontal cortex (OFC) can accompany these same disorders, and these structures are implicated in some forms of decision-making. The current study investigated the role of the BLA and OFC in decision-making under risk of explicit punishment. Rats were trained in the risky decision-making task (RDT), in which they chose between two levers, one that delivered a small safe reward, and the other that delivered a large reward accompanied by varying risks of footshock punishment. Following training, they received sham or neurotoxic lesions of BLA or OFC, followed by RDT retesting. BLA lesions increased choice of the large risky reward (greater risk-taking) compared to both prelesion performance and sham controls. When reward magnitudes were equated, both BLA lesion and control groups shifted their choice to the safe (no shock) reward lever, indicating that the lesions did not impair punishment sensitivity. In contrast to BLA lesions, OFC lesions significantly decreased risk-taking compared with sham controls, but did not impair discrimination between different reward magnitudes or alter baseline levels of anxiety. Finally, neither lesion significantly affected food-motivated lever pressing under various fixed ratio schedules, indicating that lesion-induced alterations in risk-taking were not secondary to changes in appetitive motivation. Together, these findings indicate distinct roles for the BLA and OFC in decision-making under risk of explicit punishment. Copyright © 2015 the authors 0270-6474/15/351368-12$15.00/0.

Pandemic influenza: certain uncertainties

PubMed Central

Morens, David M.; Taubenberger, Jeffery K.

2011-01-01

SUMMARY For at least five centuries, major epidemics and pandemics of influenza have occurred unexpectedly and at irregular intervals. Despite the modern notion that pandemic influenza is a distinct phenomenon obeying such constant (if incompletely understood) rules such as dramatic genetic change, cyclicity, “wave” patterning, virus replacement, and predictable epidemic behavior, much evidence suggests the opposite. Although there is much that we know about pandemic influenza, there appears to be much more that we do not know. Pandemics arise as a result of various genetic mechanisms, have no predictable patterns of mortality among different age groups, and vary greatly in how and when they arise and recur. Some are followed by new pandemics, whereas others fade gradually or abruptly into long-term endemicity. Human influenza pandemics have been caused by viruses that evolved singly or in co-circulation with other pandemic virus descendants and often have involved significant transmission between, or establishment of, viral reservoirs within other animal hosts. In recent decades, pandemic influenza has continued to produce numerous unanticipated events that expose fundamental gaps in scientific knowledge. Influenza pandemics appear to be not a single phenomenon but a heterogeneous collection of viral evolutionary events whose similarities are overshadowed by important differences, the determinants of which remain poorly understood. These uncertainties make it difficult to predict influenza pandemics and, therefore, to adequately plan to prevent them. PMID:21706672

Intrinsic Valuation of Information in Decision Making under Uncertainty

PubMed Central

Bode, Stefan; Brydevall, Maja; Murawski, Carsten

2016-01-01

In a dynamic world, an accurate model of the environment is vital for survival, and agents ought regularly to seek out new information with which to update their world models. This aspect of behaviour is not captured well by classical theories of decision making, and the cognitive mechanisms of information seeking are poorly understood. In particular, it is not known whether information is valued only for its instrumental use, or whether humans also assign it a non-instrumental intrinsic value. To address this question, the present study assessed preference for non-instrumental information among 80 healthy participants in two experiments. Participants performed a novel information preference task in which they could choose to pay a monetary cost to receive advance information about the outcome of a monetary lottery. Importantly, acquiring information did not alter lottery outcome probabilities. We found that participants were willing to incur considerable monetary costs to acquire payoff-irrelevant information about the lottery outcome. This behaviour was well explained by a computational cognitive model in which information preference resulted from aversion to temporally prolonged uncertainty. These results strongly suggest that humans assign an intrinsic value to information in a manner inconsistent with normative accounts of decision making under uncertainty. This intrinsic value may be associated with adaptive behaviour in real-world environments by producing a bias towards exploratory and information-seeking behaviour. PMID:27416034

Interacting Supernovae: Types IIn and Ibn

NASA Astrophysics Data System (ADS)

Smith, Nathan

Supernovae that show evidence of strong shock interaction between their ejecta and pre-existing slower circumstellar material (CSM) constitute an interesting, diverse, and still poorly understood category of explosive transients. The chief reason they are extremely interesting is because they tell us that in a subset of stellar deaths, the progenitor star becomes wildly unstable in the years, decades, or centuries before explosion. This is something that has not been included in standard stellar evolution models but may significantly change the end product and yield of that evolution and complicates our attempts to map SNe to their progenitors. Another reason they are interesting is because CSM interaction is an efficient engine for making bright transients, allowing superluminous transients to arise from normal SN explosion energy, and transients of normal supernova luminosity to arise from sub-energetic explosions or low radioactivity yield. CSM interaction shrouds the fast ejecta in bright shock emission, obscuring our view of the underlying explosion, and the radiation hydrodynamics is challenging to model. The CSM interaction may also be highly nonspherical, perhaps linked to binary interaction in the progenitor system. In some cases, these complications make it difficult to tell the difference between a core-collapse and thermonuclear explosion or to discern between a nonterminal eruption, failed supernova, or weak supernova. Efforts to uncover the physical parameters of individual events and connections to progenitor stars make this a rapidly evolving topic that challenges paradigms of stellar evolution.

Tracking contaminant flux from aquatic to terrestrial food webs

EPA Science Inventory

Aquatic insects provide a critical energy subsidy to riparian food webs, yet their role as vectors of contaminants to terrestrial ecosystems is poorly understood. We investigated aquatic resource utilization and contaminant exposure among riparian invertivores (spiders and herpt...

Asthma and Respiratory Allergic Disease

EPA Science Inventory

The pathogenesis of non-communicable diseases such as allergy is complex and poorly understood. The causes of chronic allergic diseases including asthma involve to a large extent, immunomodulation of the adaptive and particularly the innate immune systems and are markedly influen...

A Production Function Approach to Regional Environmental Economic Assessments

EPA Science Inventory

Regional-scale environmental assessments require integrating many available types of data having inconsistent spatial or temporal scales. Moreover, the relationships among the environmental variables in the assessment tend to be poorly understood, a situation made even more compl...

AtCHX13 is a plasma membrane K(+) transporter

USDA-ARS?s Scientific Manuscript database

Potassium (K+) homeostasis is essential for diverse cellular processes, although how various cation transporters collaborate to maintain a suitable K(+) required for growth and development is poorly understood. The Arabidopsis ("Arabidopsis thaliana") genome contains numerous cation:proton antiporte...

AtCHX13 is a plasma membrane K+ transporter

USDA-ARS?s Scientific Manuscript database

Potassium (K+) homeostasis is essential for diverse cellular processes, although how various cation transporters collaborate to maintain a suitable K+ required for growth and development is poorly understood. The Arabidopsis (Arabidopsis thaliana) genome contains numerous cation:proton antiporters (...

The 2011 National Wetland Condition Assessment

EPA Science Inventory

The ecological condition of wetland resources across the conterminous United States is poorly understood. To address this issue, the U.S. Environmental Protection Agency (USEPA), in collaboration with states, tribes, and other federal partners, is conducting the first-ever Natio...

Impacts of Human Activity on the Microbial Communities of Devon Island, Canadian High Arctic

NASA Astrophysics Data System (ADS)

Bywaters, K. B.; Burton, A. S.; Wallace, S. L.; Glass, B. J.

2016-09-01

The impacts of human activities on microbial communities in arctic environments are poorly understood. This project compares the distribution of microbes at the HMP Mars analog site prior to and after human settlement.

AN IMPROVED METHOD FOR DETECTING VIRUSES IN WATER

EPA Science Inventory

Enteroviruses are important etiological agents of waterborne disease and are responsible for outbreaks of gastroenteritis. However, the prevalence and occurrence of these pathogens in raw drinking water sources is poorly understood. This is primarily due to the limited methods ...

The mechanisms of intrarenal hemodynamic changes following acute arterial occlusion.

DOT National Transportation Integrated Search

1963-10-01

The hemodynamic response of the kidney to acute arterial occlusion is poorly understood. The purpose of the present study was to determine intrarenal hemodynamic changes in intact and isolated kidneys following arterial occlusion. : The relative role...

Prediction of Membership in Rehabilitation Counseling Professional Associations

ERIC Educational Resources Information Center

Phillips, Brian N.; Leahy, Michael J.

2012-01-01

Declining membership is a concerning yet poorly understood issue affecting professional associations across disciplines (Bauman, 2008). Rehabilitation counseling association membership is in decline even while number of certified rehabilitation counselors continues to increase (Leahy, 2009). Factors influencing rehabilitation counseling…

The prevalence and causes of autistic spectrum disorders.

PubMed

Hainsworth, Terry

Autism and autistic spectrum disorders are still relatively poorly understood. This article outlines the results of new research into the prevalence of autism and into the causes of the condition and highlights implications for nurses from the findings.

Familiarity and Aptness in Metaphor Comprehension.

PubMed

Damerall, Alison Whiteford; Kellogg, Ronald T

2016-01-01

The career of metaphor hypothesis suggests that novel metaphors are understood through a search for shared features between the topic and vehicle, but with repeated exposure, the figurative meaning is understood directly as a new category is established. The categorization hypothesis argues that instead good or apt metaphors are understood through a categorization process, whether or not they are familiar. Only poor metaphors ever invoke a literal comparison. In Experiment 1, with aptness equated, we found that high familiarity speeded comprehension time over low-familiarity metaphors. In Experiment 2a, providing a literal prime failed to facilitate interpretation of low-familiarity metaphors, contrary to the career of metaphor hypothesis. In Experiment 2b, with familiarity equated, high- and low-aptness metaphors did not differ, contrary to the categorization hypothesis.

Loneliness in psychosis: a systematic review.

PubMed

Lim, Michelle H; Gleeson, John F M; Alvarez-Jimenez, Mario; Penn, David L

2018-03-01

The aim of the review is to understand the relationships between loneliness and related psychological and social factors in individuals with psychosis. Loneliness is poorly understood in people with psychosis. Given the myriad of social challenges facing individuals with psychosis, these findings can inform psychosocial interventions that specifically target loneliness in this vulnerable group. We adhered to the PRISMA guidelines and systematically reviewed empirical studies that measured loneliness either as a main outcome or as an associated variable in individuals with psychosis. A total of ten studies examining loneliness in people diagnosed with a psychotic disorder were examined. Heterogeneity in the assessment of loneliness was found, and there were contradictory findings on the relationship between loneliness and psychotic symptomatology. In individuals with psychosis, loneliness may be influenced by psychological and social factors such as increased depression, psychosis, and anxiety, poor social support, poor quality of life, more severe internalised stigma and perceived discrimination, and low self-esteem. The relationship between loneliness and psychosis remains poorly understood due to a lack of rigorous studies. Although having strong social relationships is crucial to facilitate recovery from serious mental illness, psychosocial interventions that specifically target loneliness in individuals with psychosis are lacking and sorely needed. Interventions targeting loneliness in those with psychosis will also need to account for additional barriers associated with psychosis (e.g., social skill deficits, impoverished social networks, and negative symptoms).

Predictors of Decision-Making on the Iowa Gambling Task: Independent Effects of Lifetime History of Substance Use Disorders and Performance on the Trail Making Test

ERIC Educational Resources Information Center

Barry, D.; Petry, N. M.

2008-01-01

Poor decision-making and executive function deficits are frequently observed in individuals with substance use disorders (SUDs), and executive deficits may contribute to poor decision-making in this population. This study examined the influence of lifetime history of an alcohol, cocaine, heroin, or polysubstance use disorder on decision-making as…

Bewildering Education

ERIC Educational Resources Information Center

Snaza, Nathan

2013-01-01

Theorists as diverse as Plato, Rousseau, Freire, Apple, and the New London Group have understood education as a practice that "makes" humans. Positing education as a practice of humanization has long been understood to be the highest, most lofty good. By drawing on feminism, critical race studies, and postcolonial studies, the author of…

Continuous-variable quantum key distribution protocols over noisy channels.

PubMed

García-Patrón, Raúl; Cerf, Nicolas J

2009-04-03

A continuous-variable quantum key distribution protocol based on squeezed states and heterodyne detection is introduced and shown to attain higher secret key rates over a noisy line than any other one-way Gaussian protocol. This increased resistance to channel noise can be understood as resulting from purposely adding noise to the signal that is converted into the secret key. This notion of noise-enhanced tolerance to noise also provides a better physical insight into the poorly understood discrepancies between the previously defined families of Gaussian protocols.

Predictive Models of Nanotoxicity: Relationship of Physicochemical Properties to Particle Movement Through Biological Barriers

EPA Science Inventory

Understanding the linkage between the physicochemical (PC) properties of nanoparticles (NP) and their activation of biological systems is poorly understood, yet fundamental to predicting nanotoxicity, idenitifying mode of actions and developing appropriate and effective regul...

Physiological benefits of nectar-feeding by a predatory beetle

USDA-ARS?s Scientific Manuscript database

Extrafloral nectar is an important food source for many animals, including predatory lady beetles (Coleoptera: Coccinellidae), although the physiological benefits of nectar consumption are poorly understood for most consumers. Under laboratory conditions, we confined new females of Coleomegilla macu...

Fructose, high fructose corn syrup, sucrose, and non-alcoholic liver disease

USDA-ARS?s Scientific Manuscript database

Nonalcoholic fatty liver disease (NAFLD), formerly called nonalcoholic steatohepatitis, is characterized by hepatic steatosis and abnormal triglyceride accumulation in liver cells. Its etiology, pathophysiology, and pathogenesis are still poorly understood. Some have suggested that the increased in...

Salary, Performance, and Superintendent Turnover

ERIC Educational Resources Information Center

Grissom, Jason A.; Mitani, Hajime

2016-01-01

Purpose: Superintendent retention is an important goal for many school districts, yet the factors contributing to superintendent turnover are poorly understood. Most prior quantitative studies of superintendent turnover have relied on small, cross-sectional samples, limiting the evidence base. Utilizing longitudinal administrative records from…

New perspectives on microbial community distortion after whole-genome amplification

EPA Science Inventory

Whole-genome amplification (WGA) has become an important tool to explore the genomic information of microorganisms in an environmental sample with limited biomass, however potential selective biases during the amplification processes are poorly understood. Here, we describe the e...

Ankle ligament injuries.

PubMed

Abbassian, Ali; Thomas, Rhidian

2008-06-01

Ankle ligament injuries in the presence or in the absence of fractures are common. They often present a diagnostic challenge, and their management is poorly understood and subject to debate. This article reviews and discusses the current literature on the management and diagnosis of these injuries.

Accurately Characterizing the Importance of Wave-Particle Interactions in Radiation Belt Dynamics: The Pitfalls of Statistical Wave Representations

NASA Technical Reports Server (NTRS)

Murphy, Kyle R.; Mann, Ian R.; Rae, I. Jonathan; Sibeck, David G.; Watt, Clare E. J.

2016-01-01

Wave-particle interactions play a crucial role in energetic particle dynamics in the Earths radiation belts. However, the relative importance of different wave modes in these dynamics is poorly understood. Typically, this is assessed during geomagnetic storms using statistically averaged empirical wave models as a function of geomagnetic activity in advanced radiation belt simulations. However, statistical averages poorly characterize extreme events such as geomagnetic storms in that storm-time ultralow frequency wave power is typically larger than that derived over a solar cycle and Kp is a poor proxy for storm-time wave power.

Perfectionism related to self-reported insomnia severity, but not when controlled for stress and emotion regulation.

PubMed

Brand, Serge; Kirov, Roumen; Kalak, Nadeem; Gerber, Markus; Pühse, Uwe; Lemola, Sakari; Correll, Christoph U; Cortese, Samuele; Meyer, Till; Holsboer-Trachsler, Edith

2015-01-01

Perfectionism is understood as a set of personality traits such as unrealistically high and rigid standards for performance, fear of failure, and excessive self-criticism. Previous studies showed a direct association between increased perfectionism and poor sleep, though without taking into account possible mediating factors. Here, we tested the hypothesis that perfectionism was directly associated with poor sleep, and that this association collapsed, if mediating factors such as stress and poor emotion regulation were taken into account. Three hundred and forty six young adult students (M=23.87 years) completed questionnaires relating to perfectionism traits, sleep, and psychological functioning such as stress perception, coping with stress, emotion regulation, and mental toughness. Perfectionism was directly associated with poor sleep and poor psychological functioning. When stress, poor coping, and poor emotion regulation were entered in the equation, perfectionism traits no longer contributed substantively to the explanation of poor sleep. Though perfectionism traits seem associated with poor sleep, the direct role of such traits seemed small, when mediating factors such as stress perception and emotion regulation were taken into account.

Perfectionism related to self-reported insomnia severity, but not when controlled for stress and emotion regulation

PubMed Central

Brand, Serge; Kirov, Roumen; Kalak, Nadeem; Gerber, Markus; Pühse, Uwe; Lemola, Sakari; Correll, Christoph U; Cortese, Samuele; Meyer, Till; Holsboer-Trachsler, Edith

2015-01-01

Background Perfectionism is understood as a set of personality traits such as unrealistically high and rigid standards for performance, fear of failure, and excessive self-criticism. Previous studies showed a direct association between increased perfectionism and poor sleep, though without taking into account possible mediating factors. Here, we tested the hypothesis that perfectionism was directly associated with poor sleep, and that this association collapsed, if mediating factors such as stress and poor emotion regulation were taken into account. Methods Three hundred and forty six young adult students (M=23.87 years) completed questionnaires relating to perfectionism traits, sleep, and psychological functioning such as stress perception, coping with stress, emotion regulation, and mental toughness. Results Perfectionism was directly associated with poor sleep and poor psychological functioning. When stress, poor coping, and poor emotion regulation were entered in the equation, perfectionism traits no longer contributed substantively to the explanation of poor sleep. Conclusion Though perfectionism traits seem associated with poor sleep, the direct role of such traits seemed small, when mediating factors such as stress perception and emotion regulation were taken into account. PMID:25678791

Mineral potential for incompatible element deposits hosted in pegmatites, alkaline rocks, and carbonatites in the Islamic Republic of Mauritania (phase V, deliverable 87): Chapter Q in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

USGS Publications Warehouse

Taylor, Cliff D.; Giles, Stuart A.

2015-01-01

USGS review of PRISM-I data suggests that there is abundant documentation of the Bou Naga alkaline complex and to a lesser degree, the Guelb er Richat carbonatite complex, but that all other occurrences of U, Th, REE, and associated elements are poorly described, and poorly understood (Taylor, 2007)

Atherosclerosis associated with pericardial effusion in a central bearded dragon (Pogona vitticeps).

PubMed

Schilliger, Lionel; Lemberger, Karin; Chai, Norin; Bourgeois, Aude; Charpentier, Maud

2010-09-01

Atherosclerosis is a common disease in pet birds, particularly in psittacines, and is frequently found when performing postmortem examinations on adult and old dogs, in which it is mainly associated with endocrine diseases, such as hypothyroidism and diabetes mellitus. However, atherosclerosis is poorly documented in reptiles and consequently poorly understood. In the current case report, atherosclerosis and pericardial effusion were diagnosed in a 2-year-old male central bearded dragon (Pogona vitticeps) based on ultrasound visualization, necropsy, and histologic examination.

USING MOLECULAR PROBES TO STUDY INTERFACIAL REDOX REACTION AT FE-BEARING SMECTITES

EPA Science Inventory

The interfacial electron transfer of clay-water systems has a wide range of significance in geochemical and biogeochernical environments. However the mechanism of interfacial electron transport is poorly understood. The electron transfer mechanism at the solid-water interfaces of...

Larval fish distribution in the St. Louis River estuary

EPA Science Inventory

Our objective was to determine what study design, environmental, and habitat variables contribute to the distribution and abundance of larval fish in the St. Louis River estuary. Larval fish habitat associations are poorly understood in Great Lakes coastal wetlands, yet critical ...

Post-traumatic unilateral plantar hyperhidrosis.

PubMed

Eren, Y; Yavasoglu, N G; Comoglu, S S

2016-02-01

Localized unilateral hyperhidrosis is rare and poorly understood, sometimes stemming from trauma. Feet, quite vulnerable to trauma are affected by disease-mediated plantar hyperhidrosis, usually bilaterally. This report describes partial hyperhidrosis developing post-traumatically on the left plantar region of a 52-year-old male.

Predator-prey interaction reveals local effects of high-altitude insect migration

USDA-ARS?s Scientific Manuscript database

High-altitude nocturnal insect migrations represent significant pulses of resources, yet are difficult to study and poorly understood. Predator-prey interactions, specifically migratory moth consumption by high-flying bats, potentially reveal flows of migratory insects across a landscape. In North...

Assessing Effects of Pesticides on the Bee Immune System

EPA Science Inventory

Populations of some managed and wild pollinators are in decline as a result of multiple interacting factors including parasites, disease, poor nutrition and pesticides. The role that diminished immunity plays in these declines is not understood. The U.S. Environmental Protection ...

DISSECTING COLONY DEVELOPMENT OF NEUROSPORA CRASSA USING mRNA PROFILING AND COMPARTATIVE GENOMICS APPROACHES

USDA-ARS?s Scientific Manuscript database

Colony development, which includes hyphal extension, branching, anastomosis and asexual sporulation are fundamental aspects of the lifecycle of filamentous fungi; genetic mechanisms underlying these phenomena are poorly understood. We conducted transcriptional profiling during colony development of...

USEPA RESEARCH ON FISH - HABITAT RELATIONSHIPS IN GREAT LAKES COASTAL MARSHES

EPA Science Inventory

Despite numerous studies documenting fish use of particular habitat elements, the role of habitat mosaics in supporting wetland fishes is poorly understood. USEPA's Mid-Continent Ecology Division has initiated research to identify relationships of fish and habitat in coastal mars...

A Cellular Game of Telephone: Trans Tissue Reprogramming of Responses to Toxic Stimuli

EPA Science Inventory

Exposure to air pollution is a leading cause of cardiopulmonary morbidity and mortality; however, while these effects outside the lung have been associated with aberrant oxidative stress and inflammation, the underlying molecular mechanisms are poorly understood. We hypothesized ...

Cellular Plasticity in the Diabetic Myocardium

DTIC Science & Technology

2017-09-01

demonstrated that obese diabetic db/db mice in a C57Bl6J background exhibit cardiac remodeling, associated with modest ventricular dilation...HFpEF, the cellular basis for fibrotic remodeling of the ventricle is poorly understood. Metabolic diseases (such as obesity and diabetes) are

Reduce Confusion about Diffusion.

ERIC Educational Resources Information Center

Hebrank, Mary R.

1997-01-01

Presents activities that allow students to explore the fundamental but poorly understood concept of diffusion by appealing to their kinesthetic senses first, then challenging their analytical skills as they try to deduce the mathematical principle involved. Presents a computer simulation of diffusion and discusses diffusion's limitations and…

INTERNATIONAL CHILDHOOD CANCER COHORT CONSORTIUM (Journal Article)

EPA Science Inventory

Childhood cancers are rare conditions whose etiology is poorly understood. There is evidence that for some, the causal pathway may commence in utero or during peri-conception. One traditional epidemiologic approach to the study of rare diseases is the use of a retrospective cas...

A Multilevel Investigation of Neighborhood Effects on Parental Warmth

ERIC Educational Resources Information Center

Tendulkar, Shalini A.; Buka, Stephen; Dunn, Erin C.; Subramanian, S. V.; Koenen, Karestan C.

2010-01-01

Although researchers recognize that social contexts shape parenting behaviors, the relationship between neighborhood environment and parenting remains poorly understood. To address this gap, we investigated the associations between compositional and contextual (structural, social, and safety) characteristics of neighborhoods and parental warmth.…

Origins of Brain Tumor Macrophages.

PubMed

De Palma, Michele

2016-12-12

The ontogeny of brain-tumor-associated macrophages is poorly understood. New findings indicate that both resident microglia and blood-derived monocytes generate the pool of macrophages that infiltrate brain tumors of either primary or metastatic origin. Copyright © 2016 Elsevier Inc. All rights reserved.

Pollinator guilds respond differently to urban habitat fragmentation in a oak-savannah ecosystem

USDA-ARS?s Scientific Manuscript database

Habitat fragmentation is widely thought to threaten biodiversity. However, response of pollinators to habitat fragmentation is still poorly understood, as pollinator communities are notoriously spatially variable. We investigated pollinator community structure in a highly fragmented oak-savannah ec...

Effects of ecosystem development on benthic secondary production in restored and created mangrove habitats

EPA Science Inventory

Wetland creation, enhancement, and restoration activities are commonly implemented to compensate for wetland loss or degradation. However, functional equivalence in restored and created wetland habitats is often poorly understood. In estuarine habitats, changes in habitat qualit...

Ozone-Induced Metabolic Impairment is Attenuated in Adrenalectomized Wistar Kyoto Rats

EPA Science Inventory

Rationale: Air pollutants have been linked to increased incidence of metabolic syndrome however the mechanisms are poorly understood. We have recently shown that ozone exposure induces significant hyperglycemia together with elevated serum leptin and epinephrine in the Wistar Ky...

THE INTERACTION OF VAPOUR PHASE ORGANIC COMPOUNDS WITH INDOOR SINKS

EPA Science Inventory

The interaction of indoor air pollutants with interior surfaces (i.e., sinks) is a well known, but poorly understood, phenomenon. Studies have shown that re-emissions of adsorbed organic vapours can contribute to elevated concentrations of organics in indoor environments. Researc...

Preschool Executive Functioning Abilities Predict Early Mathematics Achievement

ERIC Educational Resources Information Center

Clark, Caron A. C.; Pritchard, Verena E.; Woodward, Lianne J.

2010-01-01

Impairments in executive function have been documented in school-age children with mathematical learning difficulties. However, the utility and specificity of preschool executive function abilities in predicting later mathematical achievement are poorly understood. This study examined linkages between children's developing executive function…

HYDRAULIC REDISTRIBUTION IN THE PACIFIC NORTHWEST: TWEAKING THE SYSTEM

EPA Science Inventory

Hydraulic redistribution (HR) has recently been documented in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the soil-root system to tease apart ...

REVIEW OF QUANTITATIVE STANDARDS AND GUIDELINES FOR FUNGI IN INDOOR AIR

EPA Science Inventory

Exposure to fungal aerosols clearly causes human disease. However, methods for assessing exposure remain poorly understood, and guidelines for interpreting data are often contradictory. The purposes of this paper are to review and compare existing guidelines for indoor airborne...

What can the rangeland decision-making survey do for you?

USDA-ARS?s Scientific Manuscript database

Every day, rangeland managers make complicated decisions to balance multiple outcomes. The complex nature of ranch decision-making is not well understood by scientists, policy makers or the general public. To fill this gap, the Wyoming Stock Growers Association has partnered with the Agricultural Re...

Out-of-Hospital Decision-Making and Factors Influencing the Regional Distribution of Injured Patients in a Trauma System

PubMed Central

Newgard, Craig D.; Nelson, Maria J.; Kampp, Michael; Saha, Somnath; Zive, Dana; Schmidt, Terri; Daya, Mohamud; Jui, Jonathan; Wittwer, Lynn; Warden, Craig; Sahni, Ritu; Stevens, Mark; Gorman, Kyle; Koenig, Karl; Gubler, Dean; Rosteck, Pontine; Lee, Jan; Hedges, Jerris R.

2011-01-01

Background The decision-making processes used for out-of-hospital trauma triage and hospital selection in regionalized trauma systems remain poorly understood. The objective of this study was to understand the process of field triage decision-making in an established trauma system. Methods We used a mixed methods approach, including EMS records to quantify triage decisions and reasons for hospital selection in a population-based, injury cohort (2006 - 2008), plus a focused ethnography to understand EMS cognitive reasoning in making triage decisions. The study included 10 EMS agencies providing service to a 4-county regional trauma system with 3 trauma centers and 13 non-trauma hospitals. For qualitative analyses, we conducted field observation and interviews with 35 EMS field providers and a round-table discussion with 40 EMS management personnel to generate an empirical model of out-of-hospital decision making in trauma triage. Results 64,190 injured patients were evaluated by EMS, of whom 56,444 (88.0%) were transported to acute care hospitals and 9,637 (17.1% of transports) were field trauma activations. For non-trauma activations, patient/family preference and proximity accounted for 78% of destination decisions. EMS provider judgment was cited in 36% of field trauma activations and was the sole criterion in 23% of trauma patients. The empirical model demonstrated that trauma triage is driven primarily by EMS provider “gut feeling” (judgment) and relies heavily on provider experience, mechanism of injury, and early visual cues at the scene. Conclusions Provider cognitive reasoning for field trauma triage is more heuristic than algorithmic and driven primarily by provider judgment, rather than specific triage criteria. PMID:21817971

Recovery of Sleep or Recovery of Self? A Grounded Theory Study of Residents' Decision Making Regarding How to Spend Their Nonclinical Postcall Time.

PubMed

Taylor, Taryn S; Nisker, Jeff; Teunissen, Pim W; Dornan, Tim; Lingard, Lorelei

2016-03-01

As resident work hours policies evolve, residents' off-duty time remains poorly understood. Despite assumptions about how residents should be using their postcall, off-duty time, there is little research on how residents actually use this time and the reasoning underpinning their activities. This study sought to understand residents' nonclinical postcall activities when they leave the hospital, their decision-making processes, and their perspectives on the relationship between these activities and their well-being or recovery. The study took place at a Liaison Committee on Medical Education-accredited Canadian medical school from 2012 to 2014. The authors recruited a purposive and convenience sample of postgraduate year 1-5 residents from six surgical and nonsurgical specialties at three hospitals affiliated with the medical school. Using a constructivist grounded theory approach, semistructured interviews were conducted, audio-taped, transcribed, anonymized, and combined with field notes. The authors analyzed interview transcripts using constant comparative analysis and performed post hoc member checking. Twenty-four residents participated. Residents characterized their predominant approach to postcall decision making as one of making trade-offs between multiple, competing, seemingly incompatible, but equally valuable, activities. Participants exhibited two different trade-off orientations: being oriented toward maintaining a normal life or toward mitigating fatigue. The authors' findings on residents' trade-off orientations suggest a dual recovery model with postcall trade-offs motivated by the recovery of sleep or of self. This model challenges the dominant viewpoint in the current duty hours literature and suggests that the duty hours discussion must be broadened to include other recovery processes.

High-Throughput Sequencing of Microbial Community Diversity and Dynamics during Douchi Fermentation.

PubMed

Yang, Lin; Yang, Hui-Lin; Tu, Zong-Cai; Wang, Xiao-Lan

2016-01-01

Douchi is a type of Chinese traditional fermented food that is an important source of protein and is used in flavouring ingredients. The end product is affected by the microbial community present during fermentation, but exactly how microbes influence the fermentation process remains poorly understood. We used an Illumina MiSeq approach to investigate bacterial and fungal community diversity during both douchi-koji making and fermentation. A total of 181,443 high quality bacterial 16S rRNA sequences and 221,059 high quality fungal internal transcribed spacer reads were used for taxonomic classification, revealing eight bacterial and three fungal phyla. Firmicutes, Actinobacteria and Proteobacteria were the dominant bacterial phyla, while Ascomycota and Zygomycota were the dominant fungal phyla. At the genus level, Staphylococcus and Weissella were the dominant bacteria, while Aspergillus and Lichtheimia were the dominant fungi. Principal coordinate analysis showed structural separation between the composition of bacteria in koji making and fermentation. However, multivariate analysis of variance based on unweighted UniFrac distances did identify distinct differences (p <0.05), and redundancy analysis identified two key genera that are largely responsible for the differences in bacterial composition between the two steps. Staphylococcus was enriched in koji making, while Corynebacterium was enriched in fermentation. This is the first investigation to integrate douchi fermentation and koji making and fermentation processes through this technological approach. The results provide insight into the microbiome of the douchi fermentation process, and reveal a structural separation that may be stratified by the environment during the production of this traditional fermented food.

Treatment decision-making among Canadian youth with severe haemophilia: a qualitative approach.

PubMed

Lane, S J; Walker, I; Chan, A K; Heddle, N M; Poon, M-C; Minuk, L; Jardine, L; Arnold, E; Sholapur, N; Webert, K E

2015-03-01

The first generation of young men using primary prophylaxis is coming of age. Important questions regarding the management of severe haemophilia with prophylaxis persist: Can prophylaxis be stopped? At what age? To what effect? Can the regimen be individualized? The reasons why some individuals discontinue or poorly comply with prophylaxis are not well understood. These issues have been explored using predominantly quantitative research approaches, yielding little insight into treatment decision-making from the perspectives of persons with haemophilia (PWH). Positioning the PWH as a source of expertise about their condition and its management, we undertook a qualitative study: (i) to explore and understand the lived experience of young men with severe haemophilia A or B and (ii) to identify the factors and inter-relationships between factors that affect young men's treatment decision-making. This manuscript reports primarily on the second objective. A modified Straussian, grounded theory methodology was used for data collection (interviews) and preliminary analysis. The study sample, youth aged 15-29, with severe haemophilia A or B, was chosen selectively and recruited through three Canadian Haemophilia Treatment Centres. We found treatment decision-making to be multi-factorial and used the Framework method to analyze the inter-relationships between factors. A typology of four distinct approaches to treatment was identified: lifestyle routine prophylaxis, situational prophylaxis, strict routine prophylaxis and no prophylaxis. Standardized treatment definitions (i.e.: 'primary' and 'secondary', 'prophylaxis') do not adequately describe the ways participants treat. Naming the variation of approaches documented in this study can improve PWH/provider communication, treatment planning and education. © 2014 John Wiley & Sons Ltd.

High-Throughput Sequencing of Microbial Community Diversity and Dynamics during Douchi Fermentation

PubMed Central

Tu, Zong-cai; Wang, Xiao-lan

2016-01-01

Douchi is a type of Chinese traditional fermented food that is an important source of protein and is used in flavouring ingredients. The end product is affected by the microbial community present during fermentation, but exactly how microbes influence the fermentation process remains poorly understood. We used an Illumina MiSeq approach to investigate bacterial and fungal community diversity during both douchi-koji making and fermentation. A total of 181,443 high quality bacterial 16S rRNA sequences and 221,059 high quality fungal internal transcribed spacer reads were used for taxonomic classification, revealing eight bacterial and three fungal phyla. Firmicutes, Actinobacteria and Proteobacteria were the dominant bacterial phyla, while Ascomycota and Zygomycota were the dominant fungal phyla. At the genus level, Staphylococcus and Weissella were the dominant bacteria, while Aspergillus and Lichtheimia were the dominant fungi. Principal coordinate analysis showed structural separation between the composition of bacteria in koji making and fermentation. However, multivariate analysis of variance based on unweighted UniFrac distances did identify distinct differences (p <0.05), and redundancy analysis identified two key genera that are largely responsible for the differences in bacterial composition between the two steps. Staphylococcus was enriched in koji making, while Corynebacterium was enriched in fermentation. This is the first investigation to integrate douchi fermentation and koji making and fermentation processes through this technological approach. The results provide insight into the microbiome of the douchi fermentation process, and reveal a structural separation that may be stratified by the environment during the production of this traditional fermented food. PMID:27992473

Age-Related Changes in Decision Making: Comparing Informed and Noninformed Situations

ERIC Educational Resources Information Center

Van Duijvenvoorde, Anna C. K.; Jansen, Brenda R. J.; Bredman, Joren C.; Huizenga, Hilde M.

2012-01-01

Advantageous decision making progressively develops into early adulthood, most specifically in complex and motivationally salient decision situations in which direct feedback on gains and losses is provided (Figner & Weber, 2011). However, the factors that underlie this developmental improvement in decision making are still not well understood.…

Decision making, cognitive distortions and emotional distress: A comparison between pathological gamblers and healthy controls.

PubMed

Ciccarelli, Maria; Griffiths, Mark D; Nigro, Giovanna; Cosenza, Marina

2017-03-01

The etiology of problem gambling is multifaceted and complex. Among others factors, poor decision making, cognitive distortions (i.e., irrational beliefs about gambling), and emotional factors (e.g., negative mood states) appear to be among the most important factors in the development and maintenance of problem gambling. Although empirical evidence has suggested that cognitive distortions facilitate gambling and negative emotions are associated with gambling, the interplay between cognitive distortions, emotional states, and decision making in gambling remains unexplored. Pathological gamblers (N = 54) and healthy controls (N = 54) completed the South Oaks Gambling Screen (SOGS), the Iowa Gambling Task (IGT), the Gambling Related Cognitions Scale (GRCS), and the Depression Anxiety Stress Scale (DASS-21). Compared to healthy controls, pathological gamblers showed poorer decision making and reported higher scores on measures assessing cognitive distortions and emotional distress. All measures were positively associated with gambling severity. A significant negative correlation between decision making and cognitive distortions was also observed. No associations were found between poor decision making and emotional distress. Logistic regression analysis indicated that cognitive distortions, emotional distress, and poor decision making were significant predictors of problem gambling. The use of self-report measures and the absence of female participants limit the generalizability of the reported findings. The present study is the first to demonstrate the mutual influence between irrational beliefs and poor decision making, as well as the role of cognitive bias, emotional distress, and poor decision making in gambling disorder. Copyright © 2016 Elsevier Ltd. All rights reserved.

Do arterial stiffness and wave reflection underlie cardiovascular risk in ethnic minorities?

PubMed

Faconti, Luca; Nanino, Elisa; Mills, Charlotte E; Cruickshank, Kennedy J

2016-01-01

Increasing evidence indicates that remarkable differences in cardiovascular risk between ethnic groups cannot be fully explained by traditional risk factors such as hypertension, diabetes or dislipidemia measured in midlife. Therefore, the underlying pathophysiology leading to this "excess risk" in ethnic minority groups is still poorly understood, and one way to address this issue is to shift the focus from "risk" to examine target organs, particularly blood vessels and their arterial properties more directly. In fact, structural and functional changes of the vascular system may be identifiable at very early stages of life when traditional factors are not yet developed. Arterial stiffening, measured as aortic pulse wave velocity, and wave reflection parameters, especially augmentation index, seem to be an important pathophysiological mechanism for the development of cardiovascular disease and predict mortality independent of other risk factors. However, data regarding these arterial indices in ethnic minorities are relatively rare and the heterogeneity between populations, techniques and statistical methods make it difficult to fully understand their role.

Selective entrainment of brain oscillations drives auditory perceptual organization.

PubMed

Costa-Faidella, Jordi; Sussman, Elyse S; Escera, Carles

2017-10-01

Perceptual sound organization supports our ability to make sense of the complex acoustic environment, to understand speech and to enjoy music. However, the neuronal mechanisms underlying the subjective experience of perceiving univocal auditory patterns that can be listened to, despite hearing all sounds in a scene, are poorly understood. We hereby investigated the manner in which competing sound organizations are simultaneously represented by specific brain activity patterns and the way attention and task demands prime the internal model generating the current percept. Using a selective attention task on ambiguous auditory stimulation coupled with EEG recordings, we found that the phase of low-frequency oscillatory activity dynamically tracks multiple sound organizations concurrently. However, whereas the representation of ignored sound patterns is circumscribed to auditory regions, large-scale oscillatory entrainment in auditory, sensory-motor and executive-control network areas reflects the active perceptual organization, thereby giving rise to the subjective experience of a unitary percept. Copyright © 2017 Elsevier Inc. All rights reserved.

Evangelical Protestants and the ACA: An Opening for Community-Based Primary Care?

PubMed

Franz, Berkeley; Skinner, Daniel

2016-07-01

Evangelical Protestants make up the largest religious subgroup in the United States, and previous research has shown that Evangelical churches are disproportionately active in community engagement and efforts toward social change. Although Evangelical Protestant perspectives have been considered with regard to persistent socioeconomic stratification and racial discrimination, less focus has been given to how churches interpret poor health outcomes within the United States. In particular, this research addresses how enduring health disparities are understood within the larger discussion of healthcare reform. Due to the similarity of approaches favored by participants in this study and community-based philosophy, a suggestion is made for future health policy dialogue. Although Evangelical Protestants have been most likely to reject all aspects of the Affordable Care Act, in many ways the findings of this study suggest the potential for successful future health policy collaboration. In particular, community-based primary care might appeal to Evangelicals and health professionals in the ongoing effort to improve population health and the quality of healthcare in the United States.

The Effect of Childhood Family Size on Fertility in Adulthood: New Evidence From IV Estimation.

PubMed

Cools, Sara; Kaldager Hart, Rannveig

2017-02-01

Although fertility is positively correlated across generations, the causal effect of children's experience with larger sibships on their own fertility in adulthood is poorly understood. With the sex composition of the two firstborn children as an instrumental variable, we estimate the effect of sibship size on adult fertility using high-quality data from Norwegian administrative registers. Our study sample is all firstborns or second-borns during the 1960s in Norwegian families with at least two children (approximately 110,000 men and 104,000 women). An additional sibling has a positive effect on male fertility, mainly causing them to have three children themselves, but has a negative effect on female fertility at the same margin. Investigation into mediators reveals that mothers of girls shift relatively less time from market to family work when an additional child is born. We speculate that this scarcity in parents' time makes girls aware of the strains of life in large families, leading them to limit their own number of children in adulthood.

Description of a method to support public health information management: organizational network analysis

PubMed Central

Merrill, Jacqueline; Bakken, Suzanne; Rockoff, Maxine; Gebbie, Kristine; Carley, Kathleen

2007-01-01

In this case study we describe a method that has potential to provide systematic support for public health information management. Public health agencies depend on specialized information that travels throughout an organization via communication networks among employees. Interactions that occur within these networks are poorly understood and are generally unmanaged. We applied organizational network analysis, a method for studying communication networks, to assess the method’s utility to support decision making for public health managers, and to determine what links existed between information use and agency processes. Data on communication links among a health department’s staff was obtained via survey with a 93% response rate, and analyzed using Organizational Risk Analyzer (ORA) software. The findings described the structure of information flow in the department’s communication networks. The analysis succeeded in providing insights into organizational processes which informed public health managers’ strategies to address problems and to take advantage of network strengths. PMID:17098480

Role of cognitive parameters in dengue hemorrhagic fever and dengue shock syndrome

PubMed Central

2013-01-01

Dengue is becoming recognized as one of the most important vector-borne human diseases. It is predominant in tropical and subtropical zones but its geographical distribution is progressively expanding, making it an escalating global health problem of today. Dengue presents with spectrum of clinical manifestations, ranging from asymptomatic, undifferentiated mild fever, dengue fever (DF), to dengue hemorrhagic fever (DHF) with or without shock (DSS), a life-threatening illness characterized by plasma leakage due to increased vascular permeability. Currently, there are no antiviral modalities or vaccines available to treat and prevent dengue. Supportive care with close monitoring is the standard clinical practice. The mechanisms leading to DHF/DSS remains poorly understood. Multiple factors have been attributed to the pathological mechanism, but only a couple of these hypotheses are popular in scientific circles. The current discussion focuses on underappreciated factors, temperature, natural IgM, and endotoxin, which may be critical components playing roles in dengue pathogenesis. PMID:24305068

Computational Precision of Mental Inference as Critical Source of Human Choice Suboptimality.

PubMed

Drugowitsch, Jan; Wyart, Valentin; Devauchelle, Anne-Dominique; Koechlin, Etienne

2016-12-21

Making decisions in uncertain environments often requires combining multiple pieces of ambiguous information from external cues. In such conditions, human choices resemble optimal Bayesian inference, but typically show a large suboptimal variability whose origin remains poorly understood. In particular, this choice suboptimality might arise from imperfections in mental inference rather than in peripheral stages, such as sensory processing and response selection. Here, we dissociate these three sources of suboptimality in human choices based on combining multiple ambiguous cues. Using a novel quantitative approach for identifying the origin and structure of choice variability, we show that imperfections in inference alone cause a dominant fraction of suboptimal choices. Furthermore, two-thirds of this suboptimality appear to derive from the limited precision of neural computations implementing inference rather than from systematic deviations from Bayes-optimal inference. These findings set an upper bound on the accuracy and ultimate predictability of human choices in uncertain environments. Copyright © 2016 Elsevier Inc. All rights reserved.

Structural Basis of Actin Filament Nucleation by Tandem W Domains

PubMed Central

Chen, Xiaorui; Ni, Fengyun; Tian, Xia; Kondrashkina, Elena; Wang, Qinghua; Ma, Jianpeng

2013-01-01

SUMMARY Spontaneous nucleation of actin is very inefficient in cells. To overcome this barrier, cells have evolved a set of actin filament nucleators to promote rapid nucleation and polymerization in response to specific stimuli. However, the molecular mechanism of actin nucleation remains poorly understood. This is hindered largely by the fact that actin nucleus, once formed, rapidly polymerizes into filament, thus making it impossible to capture stable multisubunit actin nucleus. Here, we report an effective double-mutant strategy to stabilize actin nucleus by preventing further polymerization. Employing this strategy, we solved the crystal structure of AMPPNP-actin in complex with the first two tandem W domains of Cordon-bleu (Cobl), a potent actin filament nucleator. Further sequence comparison and functional studies suggest that the nucleation mechanism of Cobl is probably shared by the p53 cofactor JMY, but not Spire. Moreover, the double-mutant strategy opens the way for atomic mechanistic study of actin nucleation and polymerization. PMID:23727244

Generating Soap Bubbles by Blowing on Soap Films

NASA Astrophysics Data System (ADS)

Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

2016-02-01

Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors.

How does creating a concept map affect item-specific encoding?

PubMed

Grimaldi, Phillip J; Poston, Laurel; Karpicke, Jeffrey D

2015-07-01

Concept mapping has become a popular learning tool. However, the processes underlying the task are poorly understood. In the present study, we examined the effect of creating a concept map on the processing of item-specific information. In 2 experiments, subjects learned categorized or ad hoc word lists by making pleasantness ratings, sorting words into categories, or creating a concept map. Memory was tested using a free recall test and a recognition memory test, which is considered to be especially sensitive to item-specific processing. Typically, tasks that promote item-specific processing enhance free recall of categorized lists, relative to category sorting. Concept mapping resulted in lower recall performance than both the pleasantness rating and category sorting condition for categorized words. Moreover, concept mapping resulted in lower recognition memory performance than the other 2 tasks. These results converge on the conclusion that creating a concept map disrupts the processing of item-specific information. (c) 2015 APA, all rights reserved.

Integration of sensory force feedback is disturbed in CRPS-related dystonia.

PubMed

Mugge, Winfred; van der Helm, Frans C T; Schouten, Alfred C

2013-01-01

Complex regional pain syndrome (CRPS) is characterized by pain and disturbed blood flow, temperature regulation and motor control. Approximately 25% of cases develop fixed dystonia. The origin of this movement disorder is poorly understood, although recent insights suggest involvement of disturbed force feedback. Assessment of sensorimotor integration may provide insight into the pathophysiology of fixed dystonia. Sensory weighting is the process of integrating and weighting sensory feedback channels in the central nervous system to improve the state estimate. It was hypothesized that patients with CRPS-related dystonia bias sensory weighting of force and position toward position due to the unreliability of force feedback. The current study provides experimental evidence for dysfunctional sensory integration in fixed dystonia, showing that CRPS-patients with fixed dystonia weight force and position feedback differently than controls do. The study shows reduced force feedback weights in CRPS-patients with fixed dystonia, making it the first to demonstrate disturbed integration of force feedback in fixed dystonia, an important step towards understanding the pathophysiology of fixed dystonia.

Studying the Role of the Mitotic Exit Network in Cytokinesis.

PubMed

Foltman, Magdalena; Sanchez-Diaz, Alberto

2017-01-01

In budding yeast cells, cytokinesis is achieved by the successful division of the cytoplasm into two daughter cells, but the precise mechanisms of cell division and its regulation are still rather poorly understood. The Mitotic Exit Network (MEN) is the signaling cascade that is responsible for the release of Cdc14 phosphatase leading to the inactivation of the kinase activity associated to cyclin-dependent kinases (CDK), which drives exit from mitosis and a rapid and efficient cytokinesis. Mitotic CDK impairs the activation of MEN before anaphase, and activation of MEN in anaphase leads to the inactivation of CDK, which presents a challenge to determine the contribution that each pathway makes to the successful onset of cytokinesis. To determine CDK and MEN contribution to cytokinesis irrespectively of each other, here we present methods to induce cytokinesis after the inactivation of CDK activity in temperature sensitive mutants of the MEN pathway. An array of methods to monitor the cellular events associated with the successful cytokinesis is included.

Cardiovascular Impact in Patients Undergoing Maintenance Hemodialysis: Clinical Management Considerations

PubMed Central

Chirakarnjanakorn, Srisakul; Navaneethan, Sankar D.; Francis, Gary S.; Tang, W.H. Wilson

2017-01-01

Patients undergoing maintenance hemodialysis develop both structural and functional cardiovascular abnormalities. Despite improvement of dialysis technology, cardiovascular mortality of this population remains high. The pathophysiological mechanisms of these changes are complex and not well understood. It has been postulated that several non-traditional, uremic-related risk factors, especially the long-term uremic state, which may affect the cardiovascular system. There are many cardiovascular changes that occur in chronic kidney disease including left ventricular hypertrophy, myocardial fibrosis, microvascular disease, accelerated atherosclerosis and arteriosclerosis. These structural and functional changes in patients receiving chronic dialysis make them more susceptible to myocardial ischemia. Hemodialysis itself may adversely affect the cardiovascular system due to non-physiologic fluid removal, leading to hemodynamic instability and initiation of systemic inflammation. In the past decade there has been growing awareness that pathophysiological mechanisms cause cardiovascular dysfunction in patients on chronic dialysis, and there are now pharmacological and non-pharmacological therapies that may improve the poor quality of life and high mortality rate that these patients experience. PMID:28108129

Smallholder farms as stepping stone corridors for crop-raiding elephant in northern Tanzania: integration of Bayesian expert system and network simulator.

PubMed

Pittiglio, Claudia; Skidmore, Andrew K; van Gils, Hein A M J; McCall, Michael K; Prins, Herbert H T

2014-03-01

Crop-raiding elephants affect local livelihoods, undermining conservation efforts. Yet, crop-raiding patterns are poorly understood, making prediction and protection difficult. We hypothesized that raiding elephants use corridors between daytime refuges and farmland. Elephant counts, crop-raiding records, household surveys, Bayesian expert system, and least-cost path simulation were used to predict four alternative categories of daily corridors: (1) footpaths, (2) dry river beds, (3) stepping stones along scattered small farms, and (4) trajectories of shortest distance to refuges. The corridor alignments were compared in terms of their minimum cumulative resistance to elephant movement and related to crop-raiding zones quantified by a kernel density function. The "stepping stone" corridors predicted the crop-raiding patterns. Elephant presence was confirmed along these corridors, demonstrating that small farms located between refuges and contiguous farmland increase habitat connectivity for elephant. Our analysis successfully predicted elephant occurrence in farmland where daytime counts failed to detect nocturnal presence. These results have conservation management implications.

What makes you tic? Translational approaches to study the role of stress and contextual triggers in Tourette syndrome

PubMed Central

Godar, Sean C; Bortolato, Marco

2016-01-01

Tourette syndrome (TS) is a neurodevelopmental condition characterized by multiple, recurring motor and phonic tics. Rich empirical evidence shows that the severity of tics and associated manifestations is increased by several stressors and contextual triggers; however, the neurobiological mechanisms responsible for symptom exacerbation in TS remain poorly understood. This conceptual gap partially reflects the high phenotypic variability in tics, as well as the existing difficulties in operationalizing and standardizing stress and its effects in a clinical setting. Animal models of TS may be highly informative tools to overcome some of these limitations; these experimental preparations have already provided critical insights on key aspects of TS pathophysiology, and may prove useful to identify the neurochemical alterations induced by different stressful contingencies. In particular, emerging knowledge on the role of contextual triggers in animal models of TS may inform the development of novel pharmacological interventions to reduce tic fluctuations in this disorder. PMID:27939782

Gas chromatography on wall-coated open-tubular columns with ionic liquid stationary phases.

PubMed

Poole, Colin F; Lenca, Nicole

2014-08-29

Ionic liquids have moved from novel to practical stationary phases for gas chromatography with an increasing portfolio of applications. Ionic liquids complement conventional stationary phases because of a combination of thermophysical and solvation properties that only exist for ionic solvents. Their high thermal stability and low vapor pressure makes them suitable as polar stationary phases for separations requiring high temperatures. Ionic liquids are good solvents and can be used to expand the chemical space for separations. They are the only stationary phases with significant hydrogen-bond acidity in common use; they extend the hydrogen-bond basicity of conventional stationary phases; they are as dipolar/polarizable as the most polar conventional stationary phases; and some ionic liquids are significantly less cohesive than conventional polar stationary phases. Problems in column coating techniques and related low column performance, column activity, and stationary phase reactivity require further exploration as the reasons for these features are poorly understood at present. Copyright © 2014 Elsevier B.V. All rights reserved.

Bacterial Translocation Ratchets: Shared Physical Principles with Different Molecular Implementations: How bacterial secretion systems bias Brownian motion for efficient translocation of macromolecules.

PubMed

Hepp, Christof; Maier, Berenike

2017-10-01

Secretion systems enable bacteria to import and secrete large macromolecules including DNA and proteins. While most components of these systems have been identified, the molecular mechanisms of macromolecular transport remain poorly understood. Recent findings suggest that various bacterial secretion systems make use of the translocation ratchet mechanism for transporting polymers across the cell envelope. Translocation ratchets are powered by chemical potential differences generated by concentration gradients of ions or molecules that are specific to the respective secretion systems. Bacteria employ these potential differences for biasing Brownian motion of the macromolecules within the conduits of the secretion systems. Candidates for this mechanism include DNA import by the type II secretion/type IV pilus system, DNA export by the type IV secretion system, and protein export by the type I secretion system. Here, we propose that these three secretion systems employ different molecular implementations of the translocation ratchet mechanism. © 2017 The Authors. BioEssays Published by WILEY Periodicals, Inc.

A Specific Nucleophilic Ring-Opening Reaction of Aziridines as a Unique Platform for the Construction of Hydrogen Polysulfides Sensors

DOE PAGES

Chen, Wei; Rosser, Ethan W.; Zhang, Di; ...

2015-05-11

Hydrogen polysulfides (H 2S n, n>1) have been recently suggested to be the actual signalling molecules that involved in sulfur-related redox biology. However the exact mechanisms of H 2S n are still poorly understood and a major hurdle in this field is the lack of reliable and convenient methods for H 2S n detection. In this work we report a unique ring-opening reaction of N-sulfonylaziridine by Na 2S 2 under mild conditions. Based on this reaction a novel H 2S n-specific fluorescent probe (AP) was developed. The probe showed high sensitivity and selectivity for H 2S n. Notably, the fluorescentmore » turn-on product, i.e. compound 1, exhibited excellent two-photon photophysical properties and a large Stokes shift. Moreover, the high solid state luminescent efficiency of compound 1 makes it a potential candidate for organic emitters and solid-state lighting devices.« less

Anxiety dissociates the adaptive functions of sensory and motor response enhancements to social threats

PubMed Central

El Zein, Marwa; Wyart, Valentin; Grèzes, Julie

2015-01-01

Efficient detection and reaction to negative signals in the environment is essential for survival. In social situations, these signals are often ambiguous and can imply different levels of threat for the observer, thereby making their recognition susceptible to contextual cues – such as gaze direction when judging facial displays of emotion. However, the mechanisms underlying such contextual effects remain poorly understood. By computational modeling of human behavior and electrical brain activity, we demonstrate that gaze direction enhances the perceptual sensitivity to threat-signaling emotions – anger paired with direct gaze, and fear paired with averted gaze. This effect arises simultaneously in ventral face-selective and dorsal motor cortices at 200 ms following face presentation, dissociates across individuals as a function of anxiety, and does not reflect increased attention to threat-signaling emotions. These findings reveal that threat tunes neural processing in fast, selective, yet attention-independent fashion in sensory and motor systems, for different adaptive purposes. DOI: http://dx.doi.org/10.7554/eLife.10274.001 PMID:26712157

Additional Electrochemical Treatment Effects on the Switching Characteristics of Anodic Porous Alumina Resistive Switching Memory

NASA Astrophysics Data System (ADS)

Otsuka, Shintaro; Takeda, Ryouta; Furuya, Saeko; Shimizu, Tomohiro; Shingubara, Shouso; Iwata, Nobuyuki; Watanabe, Tadataka; Takano, Yoshiki; Takase, Kouichi

2012-06-01

We have investigated the current-voltage characteristics of a resistive switching memory (ReRAM), especially the reproducibility of the switching voltage between an insulating state and a metallic state. The poor reproducibility hinders the practical use of this memory. According to a filament model, the variation of the switching voltage may be understood in terms of the random choice of filaments with different conductivities and lengths at each switching. A limitation of the number of conductive paths is expected to lead to the suppression of the variation of switching voltage. In this study, two strategies for the limitation have been proposed using an anodic porous alumina (APA). The first is the reduction of the number of conductive paths by restriction of the contact area between the top electrodes and the insulator. The second is the lowering of the resistivity of the insulator, which makes it possible to grow filaments with the same characteristics by electrochemical treatments using a pulse-electroplating technique.

De Novo Chromosome Structure Prediction

NASA Astrophysics Data System (ADS)

di Pierro, Michele; Cheng, Ryan R.; Lieberman-Aiden, Erez; Wolynes, Peter G.; Onuchic, Jose'n.

Chromatin consists of DNA and hundreds of proteins that interact with the genetic material. In vivo, chromatin folds into nonrandom structures. The physical mechanism leading to these characteristic conformations, however, remains poorly understood. We recently introduced MiChroM, a model that generates chromosome conformations by using the idea that chromatin can be subdivided into types based on its biochemical interactions. Here we extend and complete our previous finding by showing that structural chromatin types can be inferred from ChIP-Seq data. Chromatin types, which are distinct from DNA sequence, are partially epigenetically controlled and change during cell differentiation, thus constituting a link between epigenetics, chromosomal organization, and cell development. We show that, for GM12878 lymphoblastoid cells we are able to predict accurate chromosome structures with the only input of genomic data. The degree of accuracy achieved by our prediction supports the viability of the proposed physical mechanism of chromatin folding and makes the computational model a powerful tool for future investigations.

Toxoplasma gondii: history and diagnostic test development.

PubMed

Wyrosdick, Heidi M; Schaefer, John J

2015-12-01

Toxoplasma gondii is a protozoa that causes toxoplasmosis in people and other animals. It is considered one of the most common parasitic infections in the world due to its impressive range of hosts, widespread environmental contamination and the diverse means by which animals can be infected. Despite its ubiquity and numerous ongoing research efforts into both its basic biology and clinical management, many aspects of diagnosis and management of this disease are poorly understood. The range of diagnostic options that is available for veterinary diagnostic investigators are notably more limited than those available to medical diagnosticians, making accurate interpretation of each test result critical. The current review joins other reviews on the parasite with a particular emphasis on the history and continued development of diagnostic tests that are useful for veterinary diagnostic investigations. An understanding of the strengths and shortcomings of current diagnostic techniques will assist veterinary and public health officials in formulating effective treatment and control strategies in diverse animal populations.

Getting the Message? Native Reactive Electrophiles Pass Two Out of Three Thresholds to be Bona Fide Signaling Mediators.

PubMed

Poganik, Jesse R; Long, Marcus J C; Aye, Yimon

2018-05-01

Precision cell signaling activities of reactive electrophilic species (RES) are arguably among the most poorly-understood means to transmit biological messages. Latest research implicates native RES to be a chemically-distinct subset of endogenous redox signals that influence cell decision making through non-enzyme-assisted modifications of specific proteins. Yet, fundamental questions remain regarding the role of RES as bona fide second messengers. Here, we lay out three sets of criteria we feel need to be met for RES to be considered as true cellular signals that directly mediate information transfer by modifying "first-responding" sensor proteins. We critically assess the available evidence and define the extent to which each criterion has been fulfilled. Finally, we offer some ideas on the future trajectories of the electrophile signaling field taking inspiration from work that has been done to understand canonical signaling mediators. Also see the video abstract here: https://youtu.be/rG7o0clVP0c. © 2018 WILEY Periodicals, Inc.

Infrared emission spectra of candidate interstellar aromatic molecules

NASA Technical Reports Server (NTRS)

Schlemmer, S.; Balucani, N.; Wagner, D. R.; Steiner, B.; Saykally, R. J.

1996-01-01

Interstellar dust is responsible, through surface reactions, for the creation of molecular hydrogen, the main component of the interstellar clouds in which new stars form. Intermediate between small, gas-phase molecules and dust are the polycyclic aromatic hydrocarbons (PAHs). Such molecules could account for 2-30% of the carbon in the Galaxy, and may provide nucleation sites for the formation of carbonaceous dust. Although PAHs have been proposed as the sources of the unidentified infrared emission bands that are observed in the spectra of a variety of interstellar sources, the emission characteristics of such molecules are still poorly understood. Here we report laboratory emission spectra of several representative PAHs, obtained in conditions approximating those of the interstellar medium, and measured over the entire spectral region spanned by the unidentified infrared bands. We find that neutral PAHs of small and moderate size can at best make only a minor contribution to these emission bands. Cations of these molecules, as well as much larger PAHs and their cations, remain viable candidates for the sources of these bands.

DSCAM-mediated control of dendritic and axonal arbor outgrowth enforces tiling and inhibits synaptic plasticity

PubMed Central

Simmons, Aaron B.; Bloomsburg, Samuel J.; Sukeena, Joshua M.; Miller, Calvin J.; Ortega-Burgos, Yohaniz; Borghuis, Bart G.

2017-01-01

Mature mammalian neurons have a limited ability to extend neurites and make new synaptic connections, but the mechanisms that inhibit such plasticity remain poorly understood. Here, we report that OFF-type retinal bipolar cells in mice are an exception to this rule, as they form new anatomical connections within their tiled dendritic fields well after retinal maturity. The Down syndrome cell-adhesion molecule (Dscam) confines these anatomical rearrangements within the normal tiled fields, as conditional deletion of the gene permits extension of dendrite and axon arbors beyond these borders. Dscam deletion in the mature retina results in expanded dendritic fields and increased cone photoreceptor contacts, demonstrating that DSCAM actively inhibits circuit-level plasticity. Electrophysiological recordings from Dscam−/− OFF bipolar cells showed enlarged visual receptive fields, demonstrating that expanded dendritic territories comprise functional synapses. Our results identify cell-adhesion molecule-mediated inhibition as a regulator of circuit-level neuronal plasticity in the adult retina. PMID:29114051

Perineural invasion in head and neck cancers - a review-

PubMed Central

Frunza, A; Slavescu, D; Lascar, I

2014-01-01

Abstract Rationale: perineural invasion is an under-recognized way of metastatic spread via tumoral invasion of the nerves. It is encountered in malignancies located in the head and neck but also in cancers involving the pancreas, colon and rectum, prostate, biliary tract and stomach. For some tumors, it may be the only way of metastatic spread. It represents a marker for poor outcome, with increased risk for locoregional recurrence and reduced survival rates. The molecular mechanisms behind this process are not yet fully understood; research is done to identify new therapeutic targets in order to achieve disease control. Objective: to make a rigorous analysis of this phenomenon and to highlight the best therapeutic approach. Method and results: a review of the current literature in order to harmonize the international protocols to our local pathology. Discussions: the surgical intervention is decisive to defeat the malignant process but must be associated with modern therapeutic methods, such as the image-guided radiation therapy and immunotherapy. PMID:25408713

Biofiltration of volatile pollutants: Engineering mechanisms for improved design, long-term operation, prediction and implementation. 1998 annual progress report

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

Davison, B.H.; Klasson, K.T.; Barton, J.W.

1998-06-01

'Biofiltration systems can be used for treatment of volatile organic compounds (VOCs); however, the systems are poorly understood and are currently operated as black boxes. Common operational problems associated with biofilters include fouling, deactivation, and overgrowth, all of which make them ineffective for continuous, long-term use. The objective of this investigation is to develop generic methods for long-term stable operation, in particular by using selective limitation of supplemental nutrients while maintaining high activity. As part of this effort, the author will provide deeper fundamental understanding of the important biological and transport mechanisms in biodestruction of sparingly soluble VOCs and extendmore » this approach and mathematical models to additional systems of high priority EM relevance--direct degradation and cometabolic degradation of priority pollutants such as BTEX and chlorinated organics. This report summarizes work after 2 years of a 3-year project. Major results are enumerated and discussed'« less

Childhood functional abdominal pain: mechanisms and management.

PubMed

Korterink, Judith; Devanarayana, Niranga Manjuri; Rajindrajith, Shaman; Vlieger, Arine; Benninga, Marc A

2015-03-01

Chronic abdominal pain is one of the most common clinical syndromes encountered in day to day clinical paediatric practice. Although common, its definition is confusing, predisposing factors are poorly understood and the pathophysiological mechanisms are not clear. The prevailing viewpoint in the pathogenesis involves the inter-relationship between changes in hypersensitivity and altered motility, to which several risk factors have been linked. Making a diagnosis of functional abdominal pain can be a challenge, as it is unclear which further diagnostic tests are necessary to exclude an organic cause. Moreover, large, well-performed, high-quality clinical trials for effective agents are lacking, which undermines evidence-based treatment. This Review summarizes current knowledge regarding the epidemiology, pathophysiology, risk factors and diagnostic work-up of functional abdominal pain. Finally, management options for children with functional abdominal pain are discussed including medications, dietary interventions, probiotics and psychological and complementary therapies, to improve understanding and to maximize the quality of care for children with this condition.

A Comparison of Techniques for Scheduling Earth-Observing Satellites

NASA Technical Reports Server (NTRS)

Globus, Al; Crawford, James; Lohn, Jason; Pryor, Anna

2004-01-01

Scheduling observations by coordinated fleets of Earth Observing Satellites (EOS) involves large search spaces, complex constraints and poorly understood bottlenecks, conditions where evolutionary and related algorithms are often effective. However, there are many such algorithms and the best one to use is not clear. Here we compare multiple variants of the genetic algorithm: stochastic hill climbing, simulated annealing, squeaky wheel optimization and iterated sampling on ten realistically-sized EOS scheduling problems. Schedules are represented by a permutation (non-temperal ordering) of the observation requests. A simple deterministic scheduler assigns times and resources to each observation request in the order indicated by the permutation, discarding those that violate the constraints created by previously scheduled observations. Simulated annealing performs best. Random mutation outperform a more 'intelligent' mutator. Furthermore, the best mutator, by a small margin, was a novel approach we call temperature dependent random sampling that makes large changes in the early stages of evolution and smaller changes towards the end of search.

Influence of culture on contraceptive utilization among HIV-positive women in Brazil, Kenya, and South Africa.

PubMed

Todd, Catherine S; Stibich, Mark A; Laher, Fatima; Malta, Monica S; Bastos, Francisco I; Imbuki, Kennedy; Shaffer, Douglas N; Sinei, Samuel K; Gray, Glenda E

2011-02-01

Contraceptive choice and discontinuation are poorly understood among HIV-positive women, and HIV disease and culture may influence decisions. We assessed factors influencing contraceptive decision-making among HIV-positive women in three countries. This qualitative assessment of 108 HIV-positive women (36/site, selected by age and parity strata) was conducted in Rio de Janeiro, Brazil; Kericho, Kenya; and Soweto, South Africa. Freelist interviews assessed knowledge and attitudes towards contraception and were analyzed enumerating frequency and saliency of mentions. There was intersite consensus around list items but priority and themes varied. Site-specific factors influencing contraceptive choice were male partner wishes and fertility desire (Brazil), side-effects (South Africa), and impact on health and HIV progression (Kenya). Age, parity, and taking antiretroviral therapy (ART) impacted some themes. Contraceptive use among HIV-positive women is substantially influenced by culture and other factors. Counseling efforts should consider individual factors in method selection and offer method variety to accommodate changing needs.

Spatial and temporal variability of rainfall and their effects on hydrological response in urban areas - a review

NASA Astrophysics Data System (ADS)

Cristiano, Elena; ten Veldhuis, Marie-claire; van de Giesen, Nick

2017-07-01

In urban areas, hydrological processes are characterized by high variability in space and time, making them sensitive to small-scale temporal and spatial rainfall variability. In the last decades new instruments, techniques, and methods have been developed to capture rainfall and hydrological processes at high resolution. Weather radars have been introduced to estimate high spatial and temporal rainfall variability. At the same time, new models have been proposed to reproduce hydrological response, based on small-scale representation of urban catchment spatial variability. Despite these efforts, interactions between rainfall variability, catchment heterogeneity, and hydrological response remain poorly understood. This paper presents a review of our current understanding of hydrological processes in urban environments as reported in the literature, focusing on their spatial and temporal variability aspects. We review recent findings on the effects of rainfall variability on hydrological response and identify gaps where knowledge needs to be further developed to improve our understanding of and capability to predict urban hydrological response.

Generating Soap Bubbles by Blowing on Soap Films.

PubMed

Salkin, Louis; Schmit, Alexandre; Panizza, Pascal; Courbin, Laurent

2016-02-19

Making soap bubbles by blowing air on a soap film is an enjoyable activity, yet a poorly understood phenomenon. Working either with circular bubble wands or long-lived vertical soap films having an adjustable steady state thickness, we investigate the formation of such bubbles when a gas is blown through a nozzle onto a film. We vary film size, nozzle radius, space between the film and nozzle, and gas density, and we measure the gas velocity threshold above which bubbles are formed. The response is sensitive to containment, i.e., the ratio between film and jet sizes, and dissipation in the turbulent gas jet, which is a function of the distance from the film to the nozzle. We rationalize the observed four different regimes by comparing the dynamic pressure exerted by the jet on the film and the Laplace pressure needed to create the curved surface of a bubble. This simple model allows us to account for the interplay between hydrodynamic, physicochemical, and geometrical factors.

Cardiac Cachexia: Perspectives for Prevention and Treatment.

PubMed

Okoshi, Marina Politi; Capalbo, Rafael Verardino; Romeiro, Fernando G; Okoshi, Katashi

2017-01-01

Cachexia is a prevalent pathological condition associated with chronic heart failure. Its occurrence predicts increased morbidity and mortality independent of important clinical variables such as age, ventricular function, or heart failure functional class. The clinical consequences of cachexia are dependent on both weight loss and systemic inflammation, which accompany cachexia development. Skeletal muscle wasting is an important component of cachexia; it often precedes cachexia development and predicts poor outcome in heart failure. Cachexia clinically affects several organs and systems. It is a multifactorial condition where underlying pathophysiological mechanisms are not completely understood making it difficult to develop specific prevention and treatment therapies. Preventive strategies have largely focused on muscle mass preservation. Different treatment options have been described, mostly in small clinical studies or experimental settings. These include nutritional support, neurohormonal blockade, reducing intestinal bacterial translocation, anemia and iron deficiency treatment, appetite stimulants, immunomodulatory agents, anabolic hormones, and physical exercise regimens. Currently, nonpharmacological therapy such as nutritional support and physical exercise are considered central to cachexia prevention and treatment.

Statistical properties of Galactic CMB foregrounds: dust and synchrotron

NASA Astrophysics Data System (ADS)

Kandel, D.; Lazarian, A.; Pogosyan, D.

2018-07-01

Recent Planck observations have revealed some of the important statistical properties of synchrotron and dust polarization, namely, the B to E mode power and temperature-E (TE) mode cross-correlation. In this paper, we extend our analysis in Kandel et al. that studied the B to E mode power ratio for polarized dust emission to include TE cross-correlation and develop an analogous formalism for synchrotron signal, all using a realistic model of magnetohydrodynamical turbulence. Our results suggest that the Planck results for both synchrotron and dust polarization can be understood if the turbulence in the Galaxy is sufficiently sub-Alfvénic. Making use of the observed poor magnetic field-density correlation, we show that the observed positive TE correlation for dust corresponds to our theoretical expectations. We also show how the B to E ratio as well as the TE cross-correlation can be used to study media magnetization, compressibility, and level of density-magnetic field correlation.

The intellectual disability gene Kirrel3 regulates target-specific mossy fiber synapse development in the hippocampus.

PubMed

Martin, E Anne; Muralidhar, Shruti; Wang, Zhirong; Cervantes, Diégo Cordero; Basu, Raunak; Taylor, Matthew R; Hunter, Jennifer; Cutforth, Tyler; Wilke, Scott A; Ghosh, Anirvan; Williams, Megan E

2015-11-17

Synaptic target specificity, whereby neurons make distinct types of synapses with different target cells, is critical for brain function, yet the mechanisms driving it are poorly understood. In this study, we demonstrate Kirrel3 regulates target-specific synapse formation at hippocampal mossy fiber (MF) synapses, which connect dentate granule (DG) neurons to both CA3 and GABAergic neurons. Here, we show Kirrel3 is required for formation of MF filopodia; the structures that give rise to DG-GABA synapses and that regulate feed-forward inhibition of CA3 neurons. Consequently, loss of Kirrel3 robustly increases CA3 neuron activity in developing mice. Alterations in the Kirrel3 gene are repeatedly associated with intellectual disabilities, but the role of Kirrel3 at synapses remained largely unknown. Our findings demonstrate that subtle synaptic changes during development impact circuit function and provide the first insight toward understanding the cellular basis of Kirrel3-dependent neurodevelopmental disorders.

The Modern Primitives: Applying New Technological Approaches to Explore the Biology of the Earliest Red Blood Cells

PubMed Central

Fraser, Stuart T.

2013-01-01

One of the most critical stages in mammalian embryogenesis is the independent production of the embryo's own circulating, functional red blood cells. Correspondingly, erythrocytes are the first cell type to become functionally mature during embryogenesis. Failure to achieve this invariably leads to in utero lethality. The recent application of technologies such as transcriptome analysis, flow cytometry, mutant embryo analysis, and transgenic fluorescent gene expression reporter systems has shed new light on the distinct erythroid lineages that arise early in development. Here, I will describe the similarities and differences between the distinct erythroid populations that must form for the embryo to survive. While much of the focus of this review will be the poorly understood primitive erythroid lineage, a discussion of other erythroid and hematopoietic lineages, as well as the cell types making up the different niches that give rise to these lineages, is essential for presenting an appropriate developmental context of these cells. PMID:24222861

Cellulose Aggregation under Hydrothermal Pretreatment Conditions.

PubMed

Silveira, Rodrigo L; Stoyanov, Stanislav R; Kovalenko, Andriy; Skaf, Munir S

2016-08-08

Cellulose, the most abundant biopolymer on Earth, represents a resource for sustainable production of biofuels. Thermochemical treatments make lignocellulosic biomaterials more amenable to depolymerization by exposing cellulose microfibrils to enzymatic or chemical attacks. In such treatments, the solvent plays fundamental roles in biomass modification, but the molecular events underlying these changes are still poorly understood. Here, the 3D-RISM-KH molecular theory of solvation has been employed to analyze the role of water in cellulose aggregation under different thermodynamic conditions. The results show that, under ambient conditions, highly structured hydration shells around cellulose create repulsive forces that protect cellulose microfibrils from aggregating. Under hydrothermal pretreatment conditions, however, the hydration shells lose structure, and cellulose aggregation is favored. These effects are largely due to a decrease in cellulose-water interactions relative to those at ambient conditions, so that cellulose-cellulose attractive interactions become prevalent. Our results provide an explanation to the observed increase in the lateral size of cellulose crystallites when biomass is subject to pretreatments and deepen the current understanding of the mechanisms of biomass modification.

Force feedback controls motor activity and mechanical properties of self-assembling branched actin networks

PubMed Central

Bieling, Peter; Li, Tai-De; Weichsel, Julian; McGorty, Ryan; Jreij, Pamela; Huang, Bo; Fletcher, Daniel A.; Mullins, R. Dyche

2016-01-01

Branched actin networks–created by the Arp2/3 complex, capping protein, and a nucleation promoting factor– generate and transmit forces required for many cellular processes, but their response to force is poorly understood. To address this, we assembled branched actin networks in vitro from purified components and used simultaneous fluorescence and atomic force microscopy to quantify their molecular composition and material properties under various forces. Remarkably, mechanical loading of these self-assembling materials increases their density, power, and efficiency. Microscopically, increased density reflects increased filament number and altered geometry, but no change in average length. Macroscopically, increased density enhances network stiffness and resistance to mechanical failure beyond those of isotropic actin networks. These effects endow branched actin networks with memory of their mechanical history that shapes their material properties and motor activity. This work reveals intrinsic force feedback mechanisms by which mechanical resistance makes self-assembling actin networks stiffer, stronger, and more powerful. PMID:26771487

Electron Pair Repulsion Responsible for the Peculiar Edge Effects and Surface Chemistry of Black Phosphorus.

PubMed

Kong, Xiang-Peng; Shen, Xiaomei; Jang, Joonkyung; Gao, Xingfa

2018-03-01

The electronic and optical properties of black phosphorus (black-P) are significantly modulated by fabricating the edges of this two-dimensional material. Electron lone pairs (ELPs) are ubiquitous in black-P, but their role in creating the edge effects of black-P is poorly understood. Using first-principle calculations, we report ELPs of black-P experience severe Coulomb repulsion and play a central role in creating the edge effects of black-P. We discover the outermost P atoms of the zigzag edges of black-PQDs are free of the Coulomb repulsion, but the P atoms of the armchair edges do experience the Coulomb repulsion. The Coulomb repulsion serves as a new chemical driving force to make electron donor-acceptor bonds with chemical groups bearing vacant orbitals. Our results provide insights into the mechanism responsible for the peculiar edge effects of black-P and highlight the opportunity to use the ELPs of black-P for their damage-free surface functionalization.

Brachymyrmex species with tumuliform metathoracic spiracles: description of three new species and discussion of dimorphism in the genus (Hymenoptera, Formicidae)

PubMed Central

Ortiz, Claudia M.; Fernández, Fernando

2014-01-01

Abstract Brachymyrmex is a taxonomically challenging ant genus that is badly in need of review. Most species are very small and soft bodied and current descriptions regularly lack clarity making species identification a daunting task. Furthermore, the monophyly of Brachymyrmex has not been established and the relationships among its species and with closely related genera are poorly understood. Most species of Brachymyrmex are monomorphic, but two dimorphic species have been assigned to the genus before. Here, we redescribe these dimorphic taxa, B. pilipes and B. micromegas, and describe three new monomorphic species, B. brasiliensis sp. n., B. delabiei sp. n. and B. feitosai sp. n. All five species occur in Brazil and have tumuliform metathoracic spiracles, which are lacking in other Brachymyrmex species. We discuss dimorphism and its evolution in the genus and provide a distribution map, illustrations and a species identification key based on workers. PMID:24493952

The Voice of Conscience in Rousseau's Emile

ERIC Educational Resources Information Center

Kodelja, Zdenko

2015-01-01

According to Rousseau, conscience and conscience alone can elevate human beings to a level above that of animals. It is conscience, understood as infallible judge of good and bad, which makes man like God. Conscience itself is, in this context, understood as divine, as an "immortal and celestial voice". Therefore, if the voice of…

IN-STREAM AND WATERSHED PREDICTORS OF GENETIC DIVERSITY, EFFECTIVE POPULATION SIZE AND IMMIGRATION ACROSS RIVER-STREAM NETWORKS

EPA Science Inventory

The influence of spatial processes on population dynamics within river-stream networks is poorly understood. Utilizing spatially explicit analyses of temporal genetic variance, we examined whether persistence of Central Stonerollers (Campostoma anomalum) reflects differences in h...

Worldwide patterns of ancestry, divergence, and admixture in domesticated cattle

USDA-ARS?s Scientific Manuscript database

The domestication and development of cattle has considerably impacted human societies, but the histories of cattle breeds have been poorly understood especially for African, Asian, and American breeds. Using genotypes from 43,043 autosomal single nucleotide polymorphism markers scored in 1,543 anima...

WWW: The Scientific Method

ERIC Educational Resources Information Center

Blystone, Robert V.; Blodgett, Kevin

2006-01-01

The scientific method is the principal methodology by which biological knowledge is gained and disseminated. As fundamental as the scientific method may be, its historical development is poorly understood, its definition is variable, and its deployment is uneven. Scientific progress may occur without the strictures imposed by the formal…

From Movements to Actions: Two Mechanisms for Learning Action Sequences

ERIC Educational Resources Information Center

Endress, Ansgar D.; Wood, Justin N.

2011-01-01

When other individuals move, we interpret their movements as discrete, hierarchically-organized, goal-directed actions. However, the mechanisms that integrate visible movement features into actions are poorly understood. Here, we consider two sequence learning mechanisms--transitional probability-based (TP) and position-based encoding…

Accumulation of the Antibiotic Phenazine-1-Carboxylic Acid in the Rhizosphere of Dryland Cereals

USDA-ARS?s Scientific Manuscript database

Natural antibiotics are thought to function in the defense, fitness, competitiveness, biocontrol activity, communication and gene regulation of microorganisms. However, the scale and quantitative aspects of antibiotic production in natural settings are poorly understood. We addressed these fundament...

Size matters: The contribution of mega-infauna to the food webs and ecosystem services of an Oregon estuary - ESA

EPA Science Inventory

Background/Questions/Methods Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because ...

Olfactory disruption: towards controlling important insect vectors of disease

USDA-ARS?s Scientific Manuscript database

Chemical repellents are used to decrease contacts between insect disease vectors and their hosts, thus reducing the probability of disease transmission. The molecular mechanisms by which repellents have their effects are poorly understood and remain a controversial topic. Here we present recent re...

Environmental enteric dysfunction is associated with carnitine deficiency and altered fatty acid oxidation

USDA-ARS?s Scientific Manuscript database

Environmental enteric dysfunction (EED), a condition characterized by small intestine inflammation and abnormal gut permeability, is widespread in children in developing countries and a major cause of growth failure. The pathophysiology of EED remains poorly understood. We measured serum metabolite...

LOCAL VS. REGIONAL EFFECTS ON FISH DIVERSITY AS MEDIATED BY STREAMFLOW DISTURBANCE REGIME

EPA Science Inventory

abstract

The interplay of local and regional processes on fish diversity is poorly understood, especially related to patterns of streamflow disturbance regime. Articulation of the relationship between flow disturbance patterns and river fishes across local to regional scal...

Disruption of the circadian clock within the cardiomyocyte influences mycardial contractile function, metabolism, and gene expression

USDA-ARS?s Scientific Manuscript database

Virtually every mammalian cell, including cardiomyocytes, possesses an intrinsic circadian clock. The role of this transcriptionally based molecular mechanism in cardiovascular biology is poorly understood. We hypothesized that the circadian clock within the cardiomyocyte influences diurnal variatio...

The role of methionine metabolism in inflammatory bowel disease

USDA-ARS?s Scientific Manuscript database

Methionine (Met) cycle activity is critical for normal cell functions. Met metabolites S-adenosylmethionine (SAM) and methylthioadenosine (MTA) are anti-inflammatory, yet their role in inflammatory bowel disease (IBD) is poorly understood. We hypothesize that active IBD leads to changes in Met metab...

Molecular basis for the thermostability of Newcastle disease virus

USDA-ARS?s Scientific Manuscript database

Thermostable Newcastle disease virus (NDV) vaccines have been used widely to protect village chickens against Newcastle disease, due to their decreased dependence on cold chain for transport and storage. However, the genetic basis underlying the NDV thermostability is poorly understood. In this stud...

Do boll weevils really diapause?

USDA-ARS?s Scientific Manuscript database

Boll weevil, Anthonomus grandis grandis Boheman, diapause has been poorly understood since the term was first used 50 yrs ago to describe the pest’s winter dormancy in temperate regions. This literature-based study found that low temperature and changes in photoperiod are the boll weevil diapause-i...

Effects of exurban development on trophic interactions in a desert landscape

USDA-ARS?s Scientific Manuscript database

Context Mechanisms of ecosystem change in urbanizing landscapes are poorly understood, especially in exurban areas featuring residential or commercial development set in a matrix of modified and natural vegetation. We asked how development altered trophic interactions and ecosystem processes in the ...

Light absorption of secondary organic aerosol: Composition and contribution of nitro-aromatic compounds

EPA Science Inventory

Secondary organic aerosol (SOA) might affect the atmospheric radiation balance through absorbing light at shorter visible and UV wavelengths. However, the composition and optical properties of light-absorbing SOA is poorly understood. In this work, SOA filter samples were collect...

Reproductive responses of northern goshawks to variable prey populations

Treesearch

Susan R. Salafsky; Richard T. Reynolds; Barry R. Noon; John A. Wiens

2007-01-01

Developing comprehensive conservation strategies requires knowledge of factors influencing population growth and persistence. Although variable prey resources are often associated with fluctuations in raptor demographic parameters, the mechanisms of food limitation are poorly understood, especially for a generalist predator like the northern goshawk (Accipiter...

The dark side of suibsidies: quantifying contaminant exposure to riparian predators via stream insects

EPA Science Inventory

Aquatic insects provide a critical nutrient subsidy to riparian food webs, yet their role as vectors of contaminants to terrestrial ecosystems is poorly understood. We investigated relationships between aquatic (resource utilization) and contaminant exposure for a riparian invert...

Relations between Alcohol, Violence and Victimization in Adolescence

ERIC Educational Resources Information Center

Shepherd, J. P.; Sutherland, I.; Newcombe, R. G.

2006-01-01

Background: Compared to links between alcohol and aggression, links between alcohol and vulnerability are poorly understood. Objectives: To determine whether there is a significant relationship between vulnerability to physical violence and alcohol consumption in adolescence independent of a relationship between alcohol consumption and violent…

Heredity Factors in Spatial Visualization.

ERIC Educational Resources Information Center

Vandenberg, S. G.

Spatial visualization is not yet clearly understood. Some researchers have concluded that two factors or abilities are involved, spatial orientation and spatial visualization. Different definitions and different tests have been proposed for these two abilities. Several studies indicate that women generally perform more poorly on spatial tests than…

Ecosystem Development after Mangrove Wetland Creation: Plant-Soil Change across a 20-year Chronosequence

EPA Science Inventory

Mangrove wetland restoration and creation efforts are increasingly proposed as mechanisms to compensate for mangrove wetland loss. However, ecosystem development and functional equivalence in restored and created mangrove wetlands is poorly understood. We compared a 20-yr chrono...

Working Model Hearts

ERIC Educational Resources Information Center

Brock, David

2009-01-01

Despite student interest, the heart is often a poorly understood topic in biology. To help students understand this vital organ's physiology, the author created this investigation activity involving the mammalian heart and its role in the circulatory system. Students design, build, and demonstrate working artificial "hearts" to exhibit what they…

Technology-Enhanced Discovery

ERIC Educational Resources Information Center

Harrow, Chris; Chin, Lillian

2014-01-01

Exploration, innovation, proof: For students, teachers, and others who are curious, keeping an open mind and being ready to investigate unusual or unexpected properties will always lead to learning something new. Technology can further this process, allowing various behaviors to be analyzed that were previously memorized or poorly understood. This…

Multi-scale assessment of human-induced changes to Amazonian instream habitats

EPA Science Inventory

Context: Land use change and forest degradation have myriad effects on tropical ecosystems. Yet their consequences for low-order streams remain very poorly understood, including in the world´s largest freshwater basin, the Amazon.Objectives: Determine the degree to which ph...

Child stunting is associated with low circulating essential amino acids

USDA-ARS?s Scientific Manuscript database

Stunting affects about one-quarter of children under five worldwide. The pathogenesis of stunting is poorly understood. Nutritional interventions have had only modest effects in reducing stunting. We hypothesized that insufficiency in essential amino acids may be limiting the linear growth of childr...

Introduction to the Thematic Minireview Series: Brain glycogen metabolism.

PubMed

Carlson, Gerald M; Dienel, Gerald A; Colbran, Roger J

2018-05-11

The synthesis of glycogen allows for efficient intracellular storage of glucose molecules in a soluble form that can be rapidly released to enter glycolysis in response to energy demand. Intensive studies of glucose and glycogen metabolism, predominantly in skeletal muscle and liver, have produced innumerable insights into the mechanisms of hormone action, resulting in the award of several Nobel Prizes over the last one hundred years. Glycogen is actually present in all cells and tissues, albeit at much lower levels than found in muscle or liver. However, metabolic and physiological roles of glycogen in other tissues are poorly understood. This series of Minireviews summarizes what is known about the enzymes involved in brain glycogen metabolism and studies that have linked glycogen metabolism to multiple brain functions involving metabolic communication between astrocytes and neurons. Recent studies unexpectedly linking some forms of epilepsy to mutations in two poorly understood proteins involved in glycogen metabolism are also reviewed. © 2018 Carlson et al.

Immigrant dairy workers' perceptions of health and safety on the farm in America's Heartland.

PubMed

Liebman, Amy King; Juarez-Carrillo, Patricia Margarita; Reyes, Iris Anne Cruz; Keifer, Matthew Charles

2016-03-01

Dairy farming is dangerous. Yearly, farms grow fewer and larger by employing immigrant workers, who have limited industrial agriculture experience and safety and health training. We examined results of five focus groups with 37 Hispanic, immigrant dairy workers. Analysis followed a grounded theory approach and employed ATLAS.ti. Reported injury experience affirmed the hazardous nature of dairy. Some workers received appropriate worker compensation benefits, whereas others were instructed to deny work-relatedness. Some employers covered medical injury costs out-of-pocket, whereas others did not. Cows were a major injury source. Pressure to work and weather were noted as injury risk factors. Worker compensation was poorly understood, and immigration status and fear of deportation influenced injury and hazard reporting. Injury management practices range from benevolent to threatening. Workers compensation is poorly understood and undocumented status is an occupational hazard. We underscore the need for further research and immigration policy change. © 2015 Wiley Periodicals, Inc.

Direct observation of closed magnetic flux trapped in the high-latitude magnetosphere.

PubMed

Fear, R C; Milan, S E; Maggiolo, R; Fazakerley, A N; Dandouras, I; Mende, S B

2014-12-19

The structure of Earth's magnetosphere is poorly understood when the interplanetary magnetic field is northward. Under this condition, uncharacteristically energetic plasma is observed in the magnetotail lobes, which is not expected in the textbook model of the magnetosphere. Using satellite observations, we show that these lobe plasma signatures occur on high-latitude magnetic field lines that have been closed by the fundamental plasma process of magnetic reconnection. Previously, it has been suggested that closed flux can become trapped in the lobe and that this plasma-trapping process could explain another poorly understood phenomenon: the presence of auroras at extremely high latitudes, called transpolar arcs. Observations of the aurora at the same time as the lobe plasma signatures reveal the presence of a transpolar arc. The excellent correspondence between the transpolar arc and the trapped closed flux at high altitudes provides very strong evidence of the trapping mechanism as the cause of transpolar arcs. Copyright © 2014, American Association for the Advancement of Science.

Sea-level-induced seismicity and submarine landslide occurrence

USGS Publications Warehouse

Brothers, Daniel S.; Luttrell, Karen M.; Chaytor, Jason D.

2013-01-01

The temporal coincidence between rapid late Pleistocene sea-level rise and large-scale slope failures is widely documented. Nevertheless, the physical mechanisms that link these phenomena are poorly understood, particularly along nonglaciated margins. Here we investigate the causal relationships between rapid sea-level rise, flexural stress loading, and increased seismicity rates along passive margins. We find that Coulomb failure stress across fault systems of passive continental margins may have increased more than 1 MPa during rapid late Pleistocene–early Holocene sea-level rise, an amount sufficient to trigger fault reactivation and rupture. These results suggest that sea-level–modulated seismicity may have contributed to a number of poorly understood but widely observed phenomena, including (1) increased frequency of large-scale submarine landslides during rapid, late Pleistocene sea-level rise; (2) emplacement of coarse-grained mass transport deposits on deep-sea fans during the early stages of marine transgression; and (3) the unroofing and release of methane gas sequestered in continental slope sediments.

Inhibiting platelet-derived growth factor beta reduces Ewing's sarcoma growth and metastasis in a novel orthotopic human xenograft model.

PubMed

Wang, Yong Xin; Mandal, Deendayal; Wang, Suizhau; Hughes, Dennis; Pollock, Raphael E; Lev, Dina; Kleinerman, Eugenie; Hayes-Jordan, Andrea

2009-01-01

Despite aggressive therapy, Ewing's sarcoma (ES) patients have a poor five-year overall survival of only 20-40%. Pulmonary metastasis is the most common form of demise in these patients. The pathogenesis of pulmonary metastasis is poorly understood and few orthotopic models exist that allow study of spontaneous pulmonary metastasis in ES. We have developed a novel orthotopic xenograft model in which spontaneous pulmonary metastases develop. While the underlying biology of ES is incompletely understood, in addition to the EWS-FLI-1 mutation, it is known that platelet-derived growth factor receptor beta (PDGFR-beta) is highly expressed in ES. Hypothesizing that PDGFR-beta expression is indicative of a specific role for this receptor protein in ES progression, the effect of PDGFR-beta inhibition on ES growth and metastasis was assessed in this novel orthotopic ES model. Silencing PDGFR-beta reduced spontaneous growth and metastasis in ES. Preclinical therapeutically relevant findings such as these may ultimately lead to new treatment initiatives in ES.

Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents.

PubMed

Seibt, Julie; Richard, Clément J; Sigl-Glöckner, Johanna; Takahashi, Naoya; Kaplan, David I; Doron, Guy; de Limoges, Denis; Bocklisch, Christina; Larkum, Matthew E

2017-09-25

How sleep influences brain plasticity is not known. In particular, why certain electroencephalographic (EEG) rhythms are linked to memory consolidation is poorly understood. Calcium activity in dendrites is known to be necessary for structural plasticity changes, but this has never been carefully examined during sleep. Here, we report that calcium activity in populations of neocortical dendrites is increased and synchronised during oscillations in the spindle range in naturally sleeping rodents. Remarkably, the same relationship is not found in cell bodies of the same neurons and throughout the cortical column. Spindles during sleep have been suggested to be important for brain development and plasticity. Our results provide evidence for a physiological link of spindles in the cortex specific to dendrites, the main site of synaptic plasticity.Different stages of sleep, marked by particular electroencephalographic (EEG) signatures, have been linked to memory consolidation, but underlying mechanisms are poorly understood. Here, the authors show that dendritic calcium synchronisation correlates with spindle-rich sleep phases.

Reproductive autonomy as self-making: procreative liberty and the practice of ethical subjectivity.

PubMed

Mills, Catherine

2013-12-01

In this article, I consider recent debates on the notion of procreative liberty, to argue that reproductive freedom can be understood as a form of positive freedom-that is, the freedom to make oneself according to various ethical and aesthetic principles or values. To make this argument, I draw on Michel Foucault's later work on ethics. Both adopting and adapting Foucault's notion of ethics as a practice of the self and of liberty, I argue that reproductive autonomy requires enactment to gain meaning within the life contexts of prospective parents. Thus, I propose a shift away from the standard negative model of freedom that sees it solely as a matter of noninterference or nonimpedance, a view advocated by major commentators such as John Harris and John Robertson. Instead, reproduction should be understood as a deeply personal project of self-making that integrates both negative and positive freedom.

Altering risky decision-making: Influence of impulsivity on the neuromodulation of prefrontal cortex.

PubMed

Cheng, Gordon L F; Lee, Tatia M C

2016-01-01

The prefrontal cortex (PFC) subserves complex cognitive abilities, including risky decision-making; the modulation of this brain area is shown to alter the way people take risks. Yet, neuromodulation of the PFC in relation to risk-taking behavior remains relatively less well-studied. Moreover, the psychological variables that influence such neuromodulation remain poorly understood. To address these issues, 16 participants took part in 3 experimental sessions on separate days. They received: (i) left anodal-right cathodal transcranial direct current stimulation (tDCS); (ii) left cathodal-right anodal stimulation; or (iii) sham stimulation while they completed two risk-taking tasks. They also measured on several cognitive-affective abilities and personality traits. It was revealed that left cathodal-right anodal stimulation led to significantly reduced risk-taking under a context of haste. The reduction of risk-taking (relative to sham) correlated with state and trait impulsivity, such that the effect was larger in more impulsive individuals. For these individuals, the tDCS effect size was considered to be large (generalized partial η(2) > .17). The effect of prefrontal-neuromodulation in reducing risk-taking was influenced by baseline impulsivity, reflecting a state-dependent effect of neuromodulation on the PFC. The results of this study carry important insights into the use of neuromodulation to alter higher cognition.

BIOFILTRATION OF VOLATILE POLLUTANTS: Fundamental Mechanisms for Improved Design, Long-term Operation, Prediction, and Implementation

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

Davison,Brian H.

2000-12-31

Biofiltration systems can be used for treatment of volatile organic compounds (VOCs); however, the systems are poorly understood and are normally operated as ''black boxes''. Common operational problems associated with biofilters include fouling, deactivation, and overgrowth, all of which make them ineffective for continuous, long-term use. The objective of this investigation was to develop generic methods for long-term stable operation, in particular by using selective limitation of supplemental nutrients while maintaining high activity. As part of this effort, we have provided a deeper fundamental understanding of the important biological and transport mechanisms in biodestruction of sparingly soluble VOCs and havemore » extended this approach and mathematical models to additional systems of high priority EM relevance--direct degradation and cometabolic degradation of priority pollutants such as BTEX and chlorinated organics. Innovative aspects of this project included development of a user-friendly two-dimensional predictive model/program for MS Windows 95/98/2000 to elucidate mass transfer and kinetic limitations in these systems, isolation of a unique microorganism capable of using sparingly soluble organic and chloroorganic VOCs as its sole carbon and energy source, and making long-term growth possible by successfully decoupling growth and degradation metabolisms in operating trickle bed bioreactors.« less

Geostatistical analysis of effective vertical hydraulic conductivity and presence of confining layers in the Shallow Glacial Drift Aquifer, Oakland County, Michigan

USGS Publications Warehouse

Bissell, E.G.; Aichele, Stephen S.

2004-01-01

About 400,000 residents of Oakland County, Mich., rely on ground water for their primary drinking-water supply. More than 90 percent of these residents draw ground water from the shallow glacial drift aquifer. Understanding the vertical hydraulic conductivity of the shallow glacial drift aquifer is important both in identifying areas of ground-water recharge and in evaluating susceptibility to contamination. The geologic environment throughout much of the county, however, is poorly understood and heterogeneous, making conventional aquifer mapping techniques difficult. Geostatistical procedures are therefore used to describe the effective vertical hydraulic conductivity of the top 50 ft of the glacial deposits and to predict the probability of finding a potentially protective confining layer at a given location. The results presented synthesize the available well-log data; however, only about 40 percent of the explainable variation in the dataset is accounted for, making the results more qualitative than quantitative. Most of the variation in the effective vertical hydraulic conductivity cannot be explained with the well-log data currently available (as of 2004). Although the geologic environment is heterogeneous, the quality-assurance process indicated that more than half of the wells in the county’s Wellkey database (statewide database for monitoring drinking-water wells) had inconsistent identifications of lithology.

ERP Correlates of Simulated Purchase Decisions

PubMed Central

Gajewski, Patrick D.; Drizinsky, Jessica; Zülch, Joachim; Falkenstein, Michael

2016-01-01

Decision making in economic context is an everyday activity but its neuronal correlates are poorly understood. The present study aimed at investigating the electrophysiological brain activity during simulated purchase decisions of technical products for a lower or higher price relative to a mean price estimated in a pilot study. Expectedly, participants mostly decided to buy a product when it was cheap and not to buy when it was expensive. However, in some trials they made counter-conformity decisions to buy a product for a higher than the average price or not to buy it despite an attractive price. These responses took more time and the variability of the response latency was enhanced relative to conformity responses. ERPs showed enhanced conflict related fronto-central N2 during both types of counter-conformity compared to conformity decisions. A reverse pattern was found for the P3a and P3b. The response-locked P3 (r-P3) was larger and the subsequent CNV smaller for counter-conformity than conformity decisions. We assume that counter-conformity decisions elevate the response threshold (larger N2), intensify response evaluation (r-P3) and attenuate the preparation for the next trial (CNV). These effects were discussed in the framework of the functional role of the fronto-parietal cortex in economic decision making. PMID:27551258

ERP Correlates of Simulated Purchase Decisions.

PubMed

Gajewski, Patrick D; Drizinsky, Jessica; Zülch, Joachim; Falkenstein, Michael

2016-01-01

Decision making in economic context is an everyday activity but its neuronal correlates are poorly understood. The present study aimed at investigating the electrophysiological brain activity during simulated purchase decisions of technical products for a lower or higher price relative to a mean price estimated in a pilot study. Expectedly, participants mostly decided to buy a product when it was cheap and not to buy when it was expensive. However, in some trials they made counter-conformity decisions to buy a product for a higher than the average price or not to buy it despite an attractive price. These responses took more time and the variability of the response latency was enhanced relative to conformity responses. ERPs showed enhanced conflict related fronto-central N2 during both types of counter-conformity compared to conformity decisions. A reverse pattern was found for the P3a and P3b. The response-locked P3 (r-P3) was larger and the subsequent CNV smaller for counter-conformity than conformity decisions. We assume that counter-conformity decisions elevate the response threshold (larger N2), intensify response evaluation (r-P3) and attenuate the preparation for the next trial (CNV). These effects were discussed in the framework of the functional role of the fronto-parietal cortex in economic decision making.

A missed Fe-S cluster handoff causes a metabolic shakeup.

PubMed

Berteau, Olivier

2018-05-25

The general framework of pathways by which iron-sulfur (Fe-S) clusters are assembled in cells is well-known, but the cellular consequences of disruptions to that framework are not fully understood. Crooks et al. report a novel cellular system that creates an acute Fe-S cluster deficiency, using mutants of ISCU, the main scaffold protein for Fe-S cluster assembly. Surprisingly, the resultant metabolic reprogramming leads to the accumulation of lipid droplets, a situation encountered in many poorly understood pathological conditions, highlighting unanticipated links between Fe-S assembly machinery and human disease. © 2018 Berteau.

The mystery of a supposed massive star exploding in a brightest cluster galaxy

NASA Astrophysics Data System (ADS)

Hosseinzadeh, Griffin

2017-08-01

Most of the diversity of core-collapse supernovae results from late-stage mass loss by their progenitor stars. Supernovae that interact with circumstellar material (CSM) are a particularly good probe of these last stages of stellar evolution. Type Ibn supernovae are a rare and poorly understood class of hydrogen-poor explosions that show signs of interaction with helium-rich CSM. The leading hypothesis is that they are explosions of very massive Wolf-Rayet stars in which the supernova ejecta excites material previously lost by stellar winds. These massive stars have very short lifetimes, and therefore should only found in actively star-forming galaxies. However, PS1-12sk is a Type Ibn supernova found on the outskirts of a giant elliptical galaxy. As this is extraordinary unlikely, we propose to obtain deep UV images of the host environment of PS1-12sk in order to map nearby star formation and/or find a potential unseen star-forming host. If star formation is detected, its amount and location will provide deep insights into the progenitor picture for the poorly-understood Type Ibn class. If star formation is still not detected, these observations would challenge the well-accepted hypothesis that these are core-collapse supernovae at all.

The doctor-patient relationship as a toolkit for uncertain clinical decisions.

PubMed

Diamond-Brown, Lauren

2016-06-01

Medical uncertainty is a well-recognized problem in healthcare, yet how doctors make decisions in the face of uncertainty remains to be understood. This article draws on interdisciplinary literature on uncertainty and physician decision-making to examine a specific physician response to uncertainty: using the doctor-patient relationship as a toolkit. Additionally, I ask what happens to this process when the doctor-patient relationship becomes fragmented. I answer these questions by examining obstetrician-gynecologists' narratives regarding how they make decisions when faced with uncertainty in childbirth. Between 2013 and 2014, I performed 21 semi-structured interviews with obstetricians in the United States. Obstetricians were selected to maximize variation in relevant physician, hospital, and practice characteristics. I began with grounded theory and moved to analytical coding of themes in relation to relevant literature. My analysis renders it evident that some physicians use the doctor-patient relationship as a toolkit for dealing with uncertainty. I analyze how this process varies for physicians in different models of care by comparing doctors' experiences in models with continuous versus fragmented doctor-patient relationships. My key findings are that obstetricians in both models appealed to the ideal of patient-centered decision-making to cope with uncertain decisions, but in practice physicians in fragmented care faced a number of challenges to using the doctor-patient relationship as a toolkit for decision-making. These challenges led to additional uncertainties and in some cases to poor outcomes for doctors and/or patients; they also raised concerns about the reproduction of inequality. Thus organization of care delivery mitigates the efficacy of doctors' use of the doctor-patient relationship toolkit for uncertain decisions. These findings have implications for theorizing about decision-making under conditions of medical uncertainty, for understanding how the doctor-patient relationship and model of care affect physician decision-making, and for forming policy on the optimal structure of medical work. Copyright © 2016 Elsevier Ltd. All rights reserved.

New Insights into the Organization, Recombination, Expression and Functional Mechanism of Low Molecular Weight Glutenin Subunit Genes in Bread Wheat

PubMed Central

Fan, Huajie; Sun, Jiazhu; Zhang, Zhongjuan; Qin, Huanju; Li, Bin; Hao, Shanting; Li, Zhensheng; Wang, Daowen; Zhang, Aimin; Ling, Hong-Qing

2010-01-01

The bread-making quality of wheat is strongly influenced by multiple low molecular weight glutenin subunit (LMW-GS) proteins expressed in the seeds. However, the organization, recombination and expression of LMW-GS genes and their functional mechanism in bread-making are not well understood. Here we report a systematic molecular analysis of LMW-GS genes located at the orthologous Glu-3 loci (Glu-A3, B3 and D3) of bread wheat using complementary approaches (genome wide characterization of gene members, expression profiling, proteomic analysis). Fourteen unique LMW-GS genes were identified for Xiaoyan 54 (with superior bread-making quality). Molecular mapping and recombination analyses revealed that the three Glu-3 loci of Xiaoyan 54 harbored dissimilar numbers of LMW-GS genes and covered different genetic distances. The number of expressed LMW-GS in the seeds was higher in Xiaoyan 54 than in Jing 411 (with relatively poor bread-making quality). This correlated with the finding of higher numbers of active LMW-GS genes at the A3 and D3 loci in Xiaoyan 54. Association analysis using recombinant inbred lines suggested that positive interactions, conferred by genetic combinations of the Glu-3 locus alleles with more numerous active LMW-GS genes, were generally important for the recombinant progenies to attain high Zeleny sedimentation value (ZSV), an important indicator of bread-making quality. A higher number of active LMW-GS genes tended to lead to a more elevated ZSV, although this tendency was influenced by genetic background. This work provides substantial new insights into the genomic organization and expression of LMW-GS genes, and molecular genetic evidence suggesting that these genes contribute quantitatively to bread-making quality in hexaploid wheat. Our analysis also indicates that selection for high numbers of active LMW-GS genes can be used for improvement of bread-making quality in wheat breeding. PMID:20975830

A New Eusuchian Crocodyliform with Novel Cranial Integument and Its Significance for the Origin and Evolution of Crocodylia

PubMed Central

Holliday, Casey M.; Gardner, Nicholas M.

2012-01-01

Crocodyliforms were one of the most successful groups of Mesozoic tetrapods, radiating into terrestrial, semiaquatic and marine environments, while occupying numerous trophic niches, including carnivorous, insectivorous, herbivorous, and piscivorous species. Among these taxa were the enigmatic, poorly represented flat-headed crocodyliforms from the late Cretaceous of northern Africa. Here we report a new, giant crocodyliform from the early Late Cretaceous (Cenomanian) Kem Kem Formation of Morocco. Represented by a partial braincase, the taxon has an extremely long, flat skull with large jaw and craniocervical muscles. The skull roof is ridged and ornamented with a broad, rough boss surrounded by significant vascular impressions, likely forming an integumentary structure unique among crocodyliforms. Size estimates using endocranial volume indicate the specimen was very large. The taxon possesses robust laterosphenoids with laterally oriented capitate processes and isolated epipterygoids, features allying it with derived eusuchians. Phylogenetic analysis finds the taxon to be a derived eusuchian and sister taxon to Aegyptosuchus, a poorly understood, early Late Cretaceous taxon from the Bahariya formation. This clade forms the sister clade of crown-group Crocodylia, making these taxa the earliest eusuchian crocodyliforms known from Africa. These results shift phylogenetic and biogeographical hypotheses on the origin of modern crocodylians towards the circum-Tethyean region and provide important new data on eusuchian morphology and evolution. PMID:22303441

A Physiologically-Based Pharmacokinetic (PBPK) Model With Metabolic Interactions of Chloroform (CHCL3) and Trichloroethylene

EPA Science Inventory

Exposure to mixtures is frequent, but biologic pathways such as metabolic inhibition, are poorly understood. CHCl3 and TCE are model volatiles frequently co-occurring; combined exposure results in less than additive hepatotoxicity. Here, we explore the underlying metabolic inte...

Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

DOT National Transportation Integrated Search

1998-03-01

The contribution of a cement-stabilized base course to the strength of the rigid pavement structure is poorly understood. The objective of this research was to obtain data on the response of the rigid pavement slab-joint-foundation system by conducti...

Integrating Demographic, Clinical,and Environmental Exposure Information to Identify Genomic Biomarkers Associated With Subtypes of Childhood Asthma

EPA Science Inventory

Childhood asthma is a multifactorial disease with a disturbingly high incidence in urbanized areas. The pathogenesis of asthma is poorly understood due to the complex relationship between genetic susceptibility and modulating environmental factors. The Mechanistic Indicators of C...

NITROGEN OUTPUTS FROM FECAL AND URINE DEPOSITION OF SMALL MAMMALS: IMPLICATIONS FOR NITROGEN CYCLING

EPA Science Inventory

The contribution of small mammals to nitrogen cycling is poorly understood, but it could have reverberations back to the producer community by maintaining or perhaps magnifying nitrogen availability. Our objective was to model nitrogen outputs (deposition of feces and urine) of ...

Accumulation of the antibiotic phenazine-1-carboxylic acid in the rhizosphere of dryland cereals

USDA-ARS?s Scientific Manuscript database

Natural antibiotics are thought to function in microbial defense, fitness, competitiveness, biocontrol, communication and gene regulation. However, the frequency and amount of antibiotics produced in nature are poorly understood. In this study, we assessed the geographic distribution of indigenous p...

Genomic medicine and ethnic differences in cardiovascular disease risk

USDA-ARS?s Scientific Manuscript database

The origins of health disparities are a poorly understood public health problem. The effects of culture, environmental hazards, and social marginalization differ between ethnicities and have strong effects on health differences. The role of the genome in health is well established and we present a s...

Extreme Precipitation and Emergency Room Visits for Influenza in Massachusetts: A Case-Crossover Analysis

EPA Science Inventory

BACKGROUND: Influenza peaks during the wintertime in temperate regions and during the annual rainy season in tropical regions – however reasons for the observed differences in disease ecology are poorly understood. We hypothesize that episodes of extreme precipitation also result...

Interdependence of endomembrane trafficking and actin dynamics during polarized growth of Arabidopsis pollen tubes

USDA-ARS?s Scientific Manuscript database

During polarized growth of pollen tubes, endomembrane trafficking and actin polymerization are two critical processes that establish membrane/wall homeostasis and maintain growth polarity. Fine-tuned interactions between these two processes are therefore necessary but poorly understood. To better un...

Evaluating the relationship between the driver and roadway to address rural intersection safety using the SHRP 2 naturalistic driving study data.

DOT National Transportation Integrated Search

2016-02-01

Rural intersections account for 30% of crashes in rural areas and 6% of all fatal crashes, representing a significant but poorly : understood safety problem. Transportation agencies have traditionally implemented countermeasures to address rural inte...

Flavonoids, alkali earth and rare earth elements affect germination of pecan pollen

USDA-ARS?s Scientific Manuscript database

The factors regulating pecan [Carya illinoinensis (Wangenh.) K. Koch] pollen grain germination on receptive stigmatic flower surfaces in vivo or in vitro in pollen viability assays are poorly understood. While there are many potential regulating factors, there is evidence for involvement of flavonol...

Neural Correlates of Socioeconomic Status in the Developing Human Brain

ERIC Educational Resources Information Center

Noble, Kimberly G.; Houston, Suzanne M.; Kan, Eric; Sowell, Elizabeth R.

2012-01-01

Socioeconomic disparities in childhood are associated with remarkable differences in cognitive and socio-emotional development during a time when dramatic changes are occurring in the brain. Yet, the neurobiological pathways through which socioeconomic status (SES) shapes development remain poorly understood. Behavioral evidence suggests that…

Gastrointestinal toxicity, systemic inflammation, and liver biochemistry in allogeneic hematopoietic stem cell transplantation

USDA-ARS?s Scientific Manuscript database

Liver toxicity is frequently seen in relation to allogeneic hematopoietic stem cell transplantation (HSCT), but pathogenesis and the risk factors are poorly understood. The purpose of this study was to investigate associations between liver toxicity, gastrointestinal toxicity, and levels of immune-r...

NITROGEN OUTPUTS OF SMALL MAMMALS FROM FECAL AND URINE DEPOSITION: IMPLICATIONS FOR NITROGEN CYCLING

EPA Science Inventory

The contribution of small mammals in nitrogen cycling is poorly understood and could have reverberations back to the producer community by maintaining or even magnifying increased nitrogen availability. Our objective was to model nitrogen outputs (deposition of feces and urine) ...

Feeding behavior and injury caused by Lygus hesperus

USDA-ARS?s Scientific Manuscript database

Despite the importance of Lygus hesperus as a crop pest in the western United States, key aspects of its feeding behavior and consequent injury to cotton are poorly understood. Previous studies of Lygus stage-dependent injury to cotton produced conflicting results. We sought to clarify these relat...

Structural Equations and Causal Explanations: Some Challenges for Causal SEM

ERIC Educational Resources Information Center

Markus, Keith A.

2010-01-01

One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

Association between fertilizer-mediated changes in microbial communities and Aedes albopictus growth and survival

USDA-ARS?s Scientific Manuscript database

Contamination of aquatic habitats with anthropogenic nutrients has been associated with an increase in mosquito larval populations but the underlying mechanisms remain poorly understood. We examined the individual and combined effects of two synthetic fertilizers (ammonium sulfate and potassium chlo...

Verbal Understanding and Pavlovian Processes

ERIC Educational Resources Information Center

Tonneau, François

2004-01-01

The behavioral processes through which people react appropriately to verbal descriptions remain poorly understood. I argue here that these processes are Pavlovian. Common objections to a Pavlovian account of symbolic behavior evidence a lack of familiarity with the relevant data or misunderstandings of operant theory. Although much remains to be…

Redefining the Longitude/Latitude Experience with a Scaffolded Geocache

ERIC Educational Resources Information Center

Hammond, Thomas; Bozdin, Alec M.; Stanlick, Sarah E.

2014-01-01

Latitude and longitude are foundational concepts for geography education, yet they are typically poorly understood by students and receive indifferent attention from instructors and publishers' materials. Social studies teachers can take advantage of increasingly ubiquitous geolocating devices such as Global Positions Systems (GPS) to provide…

Wheat streak mosaic virus coat protein is a host-specific long-distance transport determinant in oat

USDA-ARS?s Scientific Manuscript database

Viral determinants involved in systemic infection of hosts by monocot-infecting plant viruses are poorly understood. Wheat streak mosaic virus (WSMV, genus Tritimovirus, family Potyviridae) exclusively infects monocotyledonous crops such as wheat, oat, barley, maize, triticale, and rye. Previously, ...

Genotype-specific responses of apple roots to pathogenic infection by Pythium ultimum

USDA-ARS?s Scientific Manuscript database

Resistance mechanisms employed to defend against soilborne necrotrophic pathogens are poorly understood, particularly with respect to perennial tree fruit crops such as apple. Pythium ultimum is a component of the pathogen complex that incites apple replant disease (ARD). Different levels of tolera...

The Structure of Integral Dimensions: Contrasting Topological and Cartesian Representations

ERIC Educational Resources Information Center

Jones, Matt; Goldstone, Robert L.

2013-01-01

Diverse evidence shows that perceptually integral dimensions, such as those composing color, are represented holistically. However, the nature of these holistic representations is poorly understood. Extant theories, such as those founded on multidimensional scaling or general recognition theory, model integral stimulus spaces using a Cartesian…

Speleothems as Examples of Chemical Equilibrium Processes.

ERIC Educational Resources Information Center

Wilson, James R.

1984-01-01

The chemical formation of speleothems such as stalactites and stalagmites is poorly understood by introductory geology instructors and misrepresented in most textbooks. Although evaporation may be a controlling factor in some caves, it is necessary to consider chemical precipitation as more important in controlling the diagenesis of calcium…

Aboveground and belowground net primary production

Treesearch

Hal O. Liechty; Mark H. Eisenbies

2000-01-01

The relationship among net primary productivity (NPP), hydroperiod, and fertility in forested wetlands is poorly understood (Burke and others 1999), particularly with respect to belowground NPP (Megonigal and others 1997). Although some researchers have studied aboveground and belowground primary production in depressional, forested wetland systems, e.g., Day and...

Remote Sensing and Underwater Glider Observations of a Springtime Plume in Western Lake Superior

EPA Science Inventory

Plumes are commonly observed in satellite imagery of western Lake Superior following storm events, and represent a significant cross-shelf pathway for sediment and other constituents. However, their subsurface extent is poorly understood. This study reports results from plume ob...

Effects of Rhododendron maximum L. on Acer rubrum L. Seedling Establishment

Treesearch

Barton D. Clinton; James M. Vose

1996-01-01

Rhododendron maximum L. restricts regeneration of overstory species; however, the mechanisms are poorly understood. Three treatments were used to examine the effects of R. maximum germination success and survival of Acer rubrum L. under a closed overstory canopy: (1) R. maximum understory, (2)...

PHOTOSYNTHETIC RESPONSES OF VALLISNERIA AMERICANA FOLLOWING EXPOSURE TO ATRAZINE AT THREE NUTRIENT REGIMES

EPA Science Inventory

The effects of anthropogenic contaminants on Gulf of Mexico plant communities are poorly understood despite the threatened condition of a number of seagrass communities and wetland habitats. In this study, we focused particular attention on the concern that elevated nutrient
l...

The Psychophysiological Mechanisms of Alexithymia in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Gaigg, Sebastian B.; Cornell, Anna S. F.; Bird, Geoffrey

2018-01-01

Accumulating evidence indicates that co-occurring alexithymia underlies several facets of the social-emotional difficulties common in individuals with autism spectrum disorder. The mechanisms involved, however, remain poorly understood because measuring alexithymia relies heavily on self-report. To address this issue, carefully matched groups of…

Sugary beverage intake and preclinical Alzheimer's disease in the community

USDA-ARS?s Scientific Manuscript database

IMPORTANCE: Sugary beverages are a key component of the Western diet, yet the long-term effects of these beverages on the brain are poorly understood. OBJECTIVE: To determine whether habitual sugary beverage consumption is associated with markers of preclinical Alzheimers disease (AD) and/or vascu...

Spread and development of Phytophthora ramorum in a California christmas tree farm

Treesearch

Gary A. Chastagner; Kathy Riley; Norm Dart

2008-01-01

The risk of conifers being infected by Phytophthora ramorum under natural conditions is poorly understood. In California, infected conifers commonly occur as understory plants beneath or adjacent to heavily infected plants like California bay laurel (Umbellularia californica). During wet periods, P. ramorum is...

Satellite observation of particulate organic carbon dynamics on the Louisiana continental shelf

EPA Science Inventory

Particulate organic carbon (POC) plays an important role in coastal carbon cycling and the formation of hypoxia. Yet, coastal POC dynamics are often poorly understood due to a lack of long-term POC observations and the complexity of coastal hydrodynamic and biogeochemical process...

HYDRAULIC REDISTRIBUTION IN A DOUGLAS-FIR FOREST: LESSONS FROM SYSTEM MANIPULATIONS

EPA Science Inventory

Hydraulic redistribution (HR) has been shown to slow drying of surface soils during drought in Pacific Northwest forests, but the controls governing this process and its importance to shallow-rooted species are poorly understood. Our objective in this study was to manipulate the...

Identification of a Pathway for Perfluorocompounds to Human Diet from Application of Biosolids to Agricultural Fields

EPA Science Inventory

Perfluoro compounds are ubiquitous contaminants in human blood. The pathways which result in near universal exposure to humans in modern societies are not clearly understood. Sources to environmental compartments and transport between compartments are only poorly studies, and thi...

Glucose supplementation has minimal effects on blood neutrophil functionand gene expression in vitro

USDA-ARS?s Scientific Manuscript database

During early lactation, glucose availability is low and the effect of glucose supply on bovine polymorphonuclear leukocyte (PMNL) function is poorly understood. The objective of this study was to determine the effect of glucose supplementation on the function and transcriptomic inflammatory respons...

Soil type and species diversity influence selection on physiology in Panicum virgatum

USDA-ARS?s Scientific Manuscript database

Species diversity influences the productivity and stability of plant communities, but its effect on the evolution of species within those communities is poorly understood. In this study, we tested whether species diversity and soil type influence selection on physiology in switchgrass (Panicum virga...

Mechanisms of increased lifespan in hypoxia in the alfalfa leafcutting bee, Megachile rotundata

USDA-ARS?s Scientific Manuscript database

Genetic variation accounts for a small amount of variation in lifespan, while environmental stressors are strong predictors. Hypoxia is an environmental stress that increases longevity in some contexts, but the mechanisms remain poorly understood. In the bee Megachile rotundata, lifespan doubles upo...

The role of emotions for moral judgments depends on the type of emotion and moral scenario.

PubMed

Ugazio, Giuseppe; Lamm, Claus; Singer, Tania

2012-06-01

Emotions seem to play a critical role in moral judgment. However, the way in which emotions exert their influence on moral judgments is still poorly understood. This study proposes a novel theoretical approach suggesting that emotions influence moral judgments based on their motivational dimension. We tested the effects of two types of induced emotions with equal valence but with different motivational implications (anger and disgust), and four types of moral scenarios (disgust-related, impersonal, personal, and beliefs) on moral judgments. We hypothesized and found that approach motivation associated with anger would make moral judgments more permissible, while disgust, associated with withdrawal motivation, would make them less permissible. Moreover, these effects varied as a function of the type of scenario: the induced emotions only affected moral judgments concerning impersonal and personal scenarios, while we observed no effects for the other scenarios. These findings suggest that emotions can play an important role in moral judgment, but that their specific effects depend upon the type of emotion induced. Furthermore, induced emotion effects were more prevalent for moral decisions in personal and impersonal scenarios, possibly because these require the performance of an action rather than making an abstract judgment. We conclude that the effects of induced emotions on moral judgments can be predicted by taking their motivational dimension into account. This finding has important implications for moral psychology, as it points toward a previously overlooked mechanism linking emotions to moral judgments.

The effects of stress and affiliation on social decision-making: Investigating the tend-and-befriend pattern.

PubMed

Steinbeis, Nikolaus; Engert, Veronika; Linz, Roman; Singer, Tania

2015-12-01

The prevalence of psychosocial stress in Western societies is constantly on the rise. Its influence on social decision-making, however, remains poorly understood. Whereas, it is known that stress triggers psychological and physiological defense mechanisms, indications of such patterns in social decisions are ambivalent. We sought to elucidate the underlying mechanisms of stress-induced social decisions. We recruited 145 men, who were individually exposed to either a psychosocial stressor or a control condition, while primed with affiliation by interacting either with members of an in- or an out-group. We found that stressed participants were less trusting and engaged in less costly punishment compared to the non-stressed control group. Interacting with out-group members led to less reciprocity and more spiteful punishment. There was no interaction between stress and the affiliation conditions in any of the used social-decision-making paradigms. Lastly, while stress-reactive cortisol levels had no effect on trust behavior, higher baseline cortisol was correlated with greater trust. Our findings suggest that previous ambiguities in data reported on the influence of stress on social decisions, namely tend-and-befriend behavior may have arisen through critical social confounds in the induction of stress. When controlling for potential social confounds, stress may trigger fight-or-flight behavior as indicated by increased social anxiety. These findings highlight the considerable context-dependence of psychosocial stress and its effects on social behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

A review of EEG, ERP, and neuroimaging studies of creativity and insight.

PubMed

Dietrich, Arne; Kanso, Riam

2010-09-01

Creativity is a cornerstone of what makes us human, yet the neural mechanisms underlying creative thinking are poorly understood. A recent surge of interest into the neural underpinnings of creative behavior has produced a banquet of data that is tantalizing but, considered as a whole, deeply self-contradictory. We review the emerging literature and take stock of several long-standing theories and widely held beliefs about creativity. A total of 72 experiments, reported in 63 articles, make up the core of the review. They broadly fall into 3 categories: divergent thinking, artistic creativity, and insight. Electroencephalographic studies of divergent thinking yield highly variegated results. Neuroimaging studies of this paradigm also indicate no reliable changes above and beyond diffuse prefrontal activation. These findings call into question the usefulness of the divergent thinking construct in the search for the neural basis of creativity. A similarly inconclusive picture emerges for studies of artistic performance, except that this paradigm also often yields activation of motor and temporoparietal regions. Neuroelectric and imaging studies of insight are more consistent, reflecting changes in anterior cingulate cortex and prefrontal areas. Taken together, creative thinking does not appear to critically depend on any single mental process or brain region, and it is not especially associated with right brains, defocused attention, low arousal, or alpha synchronization, as sometimes hypothesized. To make creativity tractable in the brain, it must be further subdivided into different types that can be meaningfully associated with specific neurocognitive processes.

Aerosol physicochemical properties in relation to meteorology: Case studies in urban, marine, and arid settings

NASA Astrophysics Data System (ADS)

Wonaschuetz, Anna

Atmospheric aerosols are a highly relevant component of the climate system affecting atmospheric radiative transfer and the hydrological cycle. As opposed to other key atmospheric constituents with climatic relevance, atmospheric aerosol particles are highly heterogeneous in time and space with respect to their size, concentration, chemical composition and physical properties. Many aspects of their life cycle are not understood, making them difficult to represent in climate models and hard to control as a pollutant. Aerosol-cloud interactions in particular are infamous as a major source of uncertainty in future climate predictions. Field measurements are an important source of information for the modeling community and can lead to a better understanding of chemical and microphysical processes. In this study, field data from urban, marine, and arid settings are analyzed and the impact of meteorological conditions on the evolution of aerosol particles while in the atmosphere is investigated. Particular attention is given to organic aerosols, which are a poorly understood component of atmospheric aerosols. Local wind characteristics, solar radiation, relative humidity and the presence or absence of clouds and fog are found to be crucial factors in the transport and chemical evolution of aerosol particles. Organic aerosols in particular are found to be heavily impacted by processes in the liquid phase (cloud droplets and aerosol water). The reported measurements serve to improve the process-level understanding of aerosol evolution in different environments and to inform the modeling community by providing realistic values for input parameters and validation of model calculations.

Microbial Biotechnology 2020; microbiology of fossil fuel resources.

PubMed

Head, Ian M; Gray, Neil D

2016-09-01

This roadmap examines the future of microbiology research and technology in fossil fuel energy recovery. Globally, the human population will be reliant on fossil fuels for energy and chemical feedstocks for at least the medium term. Microbiology is already important in many areas relevant to both upstream and downstream activities in the oil industry. However, the discipline has struggled for recognition in a world dominated by geophysicists and engineers despite widely known but still poorly understood microbially mediated processes e.g. reservoir biodegradation, reservoir souring and control, microbial enhanced oil recovery. The role of microbiology is even less understood in developing industries such as shale gas recovery by fracking or carbon capture by geological storage. In the future, innovative biotechnologies may offer new routes to reduced emissions pathways especially when applied to the vast unconventional heavy oil resources formed, paradoxically, from microbial activities in the geological past. However, despite this potential, recent low oil prices may make industry funding hard to come by and recruitment of microbiologists by the oil and gas industry may not be a high priority. With regards to public funded research and the imperative for cheap secure energy for economic growth in a growing world population, there are signs of inherent conflicts between policies aimed at a low carbon future using renewable technologies and policies which encourage technologies which maximize recovery from our conventional and unconventional fossil fuel assets. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Poor Decision Making Is a Consequence of Cognitive Decline among Older Persons without Alzheimer’s Disease or Mild Cognitive Impairment

PubMed Central

Boyle, Patricia A.; Yu, Lei; Wilson, Robert S.; Gamble, Keith; Buchman, Aron S.; Bennett, David A.

2012-01-01

Objective Decision making is an important determinant of health and well-being across the lifespan but is critical in aging, when many influential decisions are made just as cognitive function declines. Increasing evidence suggests that older adults, even those without dementia, often make poor decisions and are selectively vulnerable to scams. To date, however, the factors associated with poor decision making in old age are unknown. The objective of this study was to test the hypothesis that poor decision making is a consequence of cognitive decline among older persons without Alzheimer’s disease or mild cognitive impairment. Methods Participants were 420 non-demented persons from the Memory and Aging Project, a longitudinal, clinical-pathologic cohort study of aging in the Chicago metropolitan area. All underwent repeated cognitive evaluations and subsequently completed assessments of decision making and susceptibility to scams. Decision making was measured using 12 items from a previously established performance-based measure and a self-report measure of susceptibility to scams. Results Cognitive function data were collected over an average of 5.5 years prior to the decision making assessment. Regression analyses were used to examine whether the prior rate of cognitive decline predicted the level of decision making and susceptibility to scams; analyses controlled for age, sex, education, and starting level of cognition. Among 420 persons without dementia, more rapid cognitive decline predicted poorer decision making and increased susceptibility to scams (p’s<0.001). Further, the relations between cognitive decline, decision making and scams persisted in analyses restricted to persons without any cognitive impairment (i.e., no dementia or even mild cognitive impairment). Conclusions Poor decision making is a consequence of cognitive decline among older persons without Alzheimer’s disease or mild cognitive impairment, those widely considered “cognitively healthy.” These findings suggest that even very subtle age-related changes in cognition have detrimental effects on judgment. PMID:22916287

Collaborative Educational Leadership: The Emergence of Human Interactional Sense-Making Process as a Complex System

ERIC Educational Resources Information Center

Jäppinen, Aini-Kristiina

2014-01-01

The article aims at explicating the emergence of human interactional sense-making process within educational leadership as a complex system. The kind of leadership is understood as a holistic entity called collaborative leadership. There, sense-making emerges across interdependent domains, called attributes of collaborative leadership. The…

Emotions Targeting Moral Exemplarity: Making Sense of the Logical Geography of Admiration, Emulation and Elevation

ERIC Educational Resources Information Center

Kristjánsson, Kristján

2017-01-01

Despite renewed interest in moral role-modelling and its emotional underpinnings, further conceptual work is needed on the logical geography of the emotions purportedly driving it, in particular, admiration, emulation and elevation. In this article, I explore admiration (as understood by Linda Zagzebski), emulation (as understood by Aristotle) and…

Evidence synthesis and its role in evidence-based health care.

PubMed

Pearson, Alan

2014-12-01

The central role of evidence synthesis (or the systematic review of evidence) in evidence-based health care is often poorly understood. There are numerous examples in the literature of poorly conceived and/or executed systematic reviews and of a lack of awareness of the international standards developed by the international leaders in systematic reviews. The Cochrane Collaboration has played a critical global role in developing and refining systematic review methods in relation to evidence of effects and of diagnostic accuracy. Copyright © 2014 Elsevier Inc. All rights reserved.

Reduction of rainbow trout spleen size by splenectomy does not alter resistance against bacterial cold water disease

USDA-ARS?s Scientific Manuscript database

In lower vertebrates, the contribution of the spleen to anti-bacterial immunity is poorly understood. Researchers have previously reported a phenotypic and genetic correlation between resistance to Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD) and spleen so...

A sprinkling experiment to quantify celerity-velocity differences at the hillslope scale

EPA Science Inventory

The difference between celerity and velocity of hillslope water flow is poorly understood. We assessed these differences by combining a 24-day hillslope sprinkling experiment with a spatially explicit hydrologic model analysis. We focused our work at Watershed 10 at the H.J. And...

Impaired Associative Taste Learning and Abnormal Brain Activation in Kinase-Defective eEF2K Mice

ERIC Educational Resources Information Center

Gildish, Iness; Manor, David; David, Orit; Sharma, Vijendra; Williams, David; Agarwala, Usha; Wang, Xuemin; Kenney, Justin W.; Proud, Chris G.; Rosenblum, Kobi

2012-01-01

Memory consolidation is defined temporally based on pharmacological interventions such as inhibitors of mRNA translation (molecular consolidation) or post-acquisition deactivation of specific brain regions (systems level consolidation). However, the relationship between molecular and systems consolidation are poorly understood. Molecular…

METABOLISM OF PBDES IN FATHEAD MINNOWS (PIMEPHALES PROMELAS) AND EFFECTS ON THYROID REGULATION

EPA Science Inventory

PBDE effects on fish and other wildlife continue to be poorly understood, and this research will contribute to filling this data gap. It will increase our understanding of PBDE metabolic pathways and mechanisms of thyroid dysfunction in fish exposed to this important class of ...

Students' Perspective into the Apathy and Social Disconnectedness They Feel in Undergraduate Business Classrooms

ERIC Educational Resources Information Center

Sashittal, Hemant C.; Jassawalla, Avan R.; Markulis, Peter

2012-01-01

Apathy and social disconnectedness among undergraduate business students remain poorly understood and under-researched--despite evidence that they produce an adverse impact on learning-related outcomes. Qualitative research was initially conducted among a sample of undergraduate business students to identify the antecedents and learning-related…

Fishing for Features

ScienceCinema

Heredia-Langner, Alejandro; Cort, John; Bailey, Vanessa

2018-01-16

The Fishing for Features Signature Discovery project developed a framework for discovering signature features in challenging environments involving large and complex data sets or where phenomena may be poorly characterized or understood. Researchers at PNNL have applied the framework to the optimization of biofuels blending and to discover signatures of climate change on microbial soil communities.

INFILTRATION THROUGH DISTURBED URBAN SOILS AND COMPOST-AMENDED SOIL EFFECTS OF RUNOFF QUALITY AND QUANTITY

EPA Science Inventory

This project examined a common, but poorly understood, problem associated with land development, namely the modifications made to soil structure and the associated reduced rainfall infiltration and increased runoff. The project was divided into two separate major tasks: 1) to tes...

Can Near-Peer Teaching Improve Academic Performance?

ERIC Educational Resources Information Center

Williams, Brett; Fowler, James

2014-01-01

Near peer teaching is becoming increasingly popular within healthcare education. The experiences and effects of near-peer teaching upon the near-peer teachers' academic performance are poorly understood. In order to address this, the objective of this study was to examine whether a near-peer teaching program improved the overall clinical unit…

Stages and Spatial Scales of Recruitment Limitation in Southern Appalachain Forests

Treesearch

James S. Clark; Eric Macklin; Leslie Wood

1998-01-01

Recruitment limitation of tree population dynamics is poorly understood, because fecundity and dispersal are difficult to characterize in closed stands. We present an approach that estimates seed production and dispersal under closed canopies and four limitations on recruitment: tree density and location, fecundity, seed dispersal, and establishment. Consistent...

Genetic structure and domestication of carrot (Daucus carota subsp. sativus L.) (Apiaceae)

USDA-ARS?s Scientific Manuscript database

Analyses of genetic structure and phylogenetic relationships illuminate the origin and domestication of modern crops. Despite being an important world-wide vegetable, the genetic structure and domestication of carrot (Daucus carota L.) is poorly understood. We provide the first such study using a la...

Emotional climate and feeding styles: observational analysis of dinner in low-income families

USDA-ARS?s Scientific Manuscript database

Indulgent feeding styles have been associated with a higher risk for childhood overweight. The processes through which feeding styles impact child weight are poorly understood. The aim of this study was to observe differences in the emotional climate created by parents (affect, tone of voice, gest...

A small cysteine-rich protein from the Asian soybean rust fungus, Phakopsora pachyrhizi, suppresses plant immunity

USDA-ARS?s Scientific Manuscript database

The Asian soybean rust fungus, Phakopsora pachyrhizi, is an obligate pathogen capable of causing explosive disease epidemics that drastically reduce the yield of soybean (Glycine max). Currently, the molecular mechanisms by which P. pachyrhizi and other rust fungi cause disease are poorly understood...

Developing Research Relationships toward a Learning Partnership

ERIC Educational Resources Information Center

Kaasila, Raimo; Lutovac, Sonja

2015-01-01

Research relationships are often poorly understood. Why are some collaborations between research partners more productive than others? This question was a starting point of this paper. By describing their own experiences over a period of three years, the authors evaluated research relationships through collaborative self-study. At the beginning,…

Reciprocal Peer Coaching: A Critical Contributor to Implementing Individual Leadership Plans

ERIC Educational Resources Information Center

Goldman, Ellen; Wesner, Marilyn; Karnchanomai, Ornpawee

2013-01-01

Billions of dollars are spent annually on programs to develop organizational leaders, yet the effectiveness of these programs is poorly understood. Scholars advise that value is enhanced by the development of individual leadership plans at program completion, followed by implementation experience with subsequent coaching and reflection. The…

BEL1-LIKE HOMEODOMAIN 11 regulated chloroplast development and chlorophyll synthesis in tomato fruit

USDA-ARS?s Scientific Manuscript database

Chloroplast development and chlorophyll content and metabolism in unripe tomato contribute to the growth and development of the fruit, and also the ripe fruit quality, but the mechanism is poorly understood. In this work, seven homeobox-containing transcription factors (TFs) with specific ripening-a...

Geographic variation in mycangial communities of Xyleborus glabratus

USDA-ARS?s Scientific Manuscript database

Abstract Factors that influence fungal communities in ambrosia beetle mycangia are poorly understood. The beetle that is responsible for spreading laurel wilt in the SE USA, Xyleborus glabratus, was examined at three sites along a 500 km N-S transect in Florida, each populated by host trees in the ...

Effects of Post-Encoding Stress on Performance in the DRM False Memory Paradigm

ERIC Educational Resources Information Center

Pardilla-Delgado, Enmanuelle; Alger, Sara E.; Cunningham, Tony J.; Kinealy, Brian; Payne, Jessica D.

2016-01-01

Numerous studies have investigated how stress impacts veridical memory, but how stress influences false memory formation remains poorly understood. In order to target memory consolidation specifically, a psychosocial stress (TSST) or control manipulation was administered following encoding of 15 neutral, semantically related word lists (DRM false…

ROOT GROWTH AND TURNOVER IN DIFFERENT AGED PONDEROSA PINE STANDS IN OREGON, USA

EPA Science Inventory

The impacts of pollution and climate change on soil carbon dynamics are poorly understood, in part due to a lack of information regarding root production and turnover in natural ecosystems. In order to examine how root dynamics change with stand age in ponderosa pine forests (...

Critical role for CCAAT/Enhancer-binding protein beta in immune complex-induced acute lung injury

USDA-ARS?s Scientific Manuscript database

Although inflammation plays a central role in the pathogenesis of acute lung injury (ALI), the molecular mechanisms underlying inflammatory responses in ALI are poorly understood, and therapeutic options remain limited. The CCAAT/enhancer-binding protein (C/EBP) gamma and -gamma have been implicated...

Starvation Promotes Odor/Feeding-Time Associations in Flies

ERIC Educational Resources Information Center

Chouhan, Nitin Singh; Wolf, Reinard; Heisenberg, Martin

2017-01-01

Starvation causes a motivational state that facilitates diverse behaviors such as feeding, walking, and search. Starved "Drosophila" can form odor/feeding-time associations but the role of starvation in encoding of "time" is poorly understood. Here we show that the extent of starvation is correlated with the fly's ability to…

Cobalt Distribution and Speciation: Effect of Aging, Intermittent Submergence, In situ Rice Roots

EPA Science Inventory

The speciation and distribution of cobalt (Co) in soils is poorly understood. This study was conducted using X-ray absorption spectroscopy (XAS) techniques to examine the influence of soluble Co(II) aging, submergence-dried cycling, and the presence of in vivo rice roots on the...

Associations among plasma metabolite levels and short-term exposure to PM2.5 and ozone in a cardiac catheterization cohort.

EPA Science Inventory

RATIONALE: Exposure to ambient particulate matter (PM) and ozone has been associated with cardiovascular disease (CVD). However, the mechanisms linking PM and ozone exposure to CVD remain poorly understood .OBJECTIVE: This study explored associations between short-term exposures ...

Accessing and Selecting Word Meaning in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Henderson, L. M.; Clarke, P. J.; Snowling, M. J.

2011-01-01

Background: Comprehension difficulties are commonly reported in autism spectrum disorder (ASD) but the causes of these difficulties are poorly understood. This study investigates how children with ASD access and select meanings of ambiguous words to test four hypotheses regarding the nature of their comprehension difficulties: semantic deficit,…

Effort versus reward: preparing samples for fungal community characterization in high-throughput sequencing surveys of soils

USDA-ARS?s Scientific Manuscript database

Next generation fungal amplicon sequencing is being used with increasing frequency to study fungal diversity in various ecosystems; however, the influence of sample preparation on the characterization of fungal community is poorly understood. We investigated the effects of four procedural modificati...

Size matters: The contribution of mega-infauna to the food webs and ecosystem services of an Oregon estuary - 9-30-12

EPA Science Inventory

Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because they are difficult to sample and...

Coping Mediates the Association between Gender and Depressive Symptomatology in Adolescence

ERIC Educational Resources Information Center

Malooly, Ashley M.; Flannery, Kaitlin M.; Ohannessian, Christine McCauley

2017-01-01

Previous studies have found evidence for gender and racial/ethnic differences in depressive symptoms in adolescence; however, the mechanisms driving this relationship are poorly understood. The goal of this study was to examine the role of individual differences in dispositional coping in the relationships between gender and depressive…

Cotton defense induction patterns under spatially, temporally and quantitatively varying herbivory levels

USDA-ARS?s Scientific Manuscript database

The optimal defense theory (ODT) predicts that plants allocate defense compounds to their tissues depending on its value and the likelihood of herbivore attack. Whereas ODT has been confirmed for static damage levels it remains poorly understood if ODT holds true for defense organization of inducibl...

Drought and leaf herbivory influence floral volatiles and pollinator attraction

Treesearch

Laura A. Burkle; Justin B. Runyon

2016-01-01

The effects of climate change on species interactions are poorly understood. Investigating the mechanisms by which species interactions may shift under altered environmental conditions will help form a more predictive understanding of such shifts. In particular, components of climate change have the potential to strongly influence floral volatile organic...

CARRY-OVER EFFECTS OF OZONE ON ROOT GROWTH AND CARBOHYDRATE CONCENTRATIONS OF PONDEROSA PINE SEEDLINGS

EPA Science Inventory

Ozone exposure decreases belowground carbon allocation and root growth of plants;however,the extent to which these effects persist and the cumulative impact of ozone stress on plant growth are poorly understood.To evaluate the potential for plant compensation,we followed the prog...

Exposure for ultrafine carbon particles at levels below detectable pulmonary inflammation affects cardiovascular performance in spontaneously hypertensive rats*

EPA Science Inventory

Rationale: Exposure to particulate matter is a risk factor for cardiopulmonary disease but the related molecular mechanisms are poorly understood. Previously we studied cardiovascular responses in healthy WKY rats following inhalation exposure to ultrafine carbon particles (UfCPs...

Relationship of neuropeptide FF receptors with pubertal maturation of gilts

USDA-ARS?s Scientific Manuscript database

Mechanisms governing the timing of puberty in pigs are poorly understood. A genome-wide association study for age at first estrus in pigs identified candidate genes including NPFFR2, which is a putative receptor for RFamide-related peptides (RFRP). RFRP has been shown to negatively regulate secret...

Development of Sensitivity to Audiovisual Temporal Asynchrony during Midchildhood

ERIC Educational Resources Information Center

Kaganovich, Natalya

2016-01-01

Temporal proximity is one of the key factors determining whether events in different modalities are integrated into a unified percept. Sensitivity to audiovisual temporal asynchrony has been studied in adults in great detail. However, how such sensitivity matures during childhood is poorly understood. We examined perception of audiovisual temporal…

Understanding Authority in Classrooms: A Review of Theory, Ideology, and Research

ERIC Educational Resources Information Center

Pace, Judith L.; Hemmings, Annette

2007-01-01

Authority is a fundamental, problematic, and poorly understood component of classroom life. A better understanding of classroom authority can be achieved by reviewing writings on social theory, educational ideology, and qualitative research in schools. Social theories provide important analytical tools for examining the constitutive elements of…

Impacts of feral horse use on riparian vegetation within the sagebrush steppe

USDA-ARS?s Scientific Manuscript database

Feral horses inhabit rangeland ecosystems around the world, but their impacts on riparian ecosystems are poorly understood. We characterized impacts of a free-ranging horse population on the structure and composition of riparian plant communities in the sagebrush steppe ecosystem in the western US....

PERCHLOROETHYLENE (PERC) INHIBITS FUNCTION OF VOLTAGE-GATED CALCIUM CHANNELS IN PHEOCHROMOCYTOMA CELLS.

EPA Science Inventory

The industrial solvent perchloroethylene (PERC) is listed as a hazardous air pollutant in the 1990 Ammendments to Clean Air Act and is a known neurotoxicant. However, the mechanisms by which PERC alters nervous system function are poorly understood. In recent years, it has been d...

RNAi-mediated down-regulation of a melanin polyketide synthase (pks1) gene in the fungus Slafractonia leguminicola

USDA-ARS?s Scientific Manuscript database

The fungus Slafractonia leguminicola, the causal agent of blackpatch disease of legumes produces two mycotoxins slaframine and swainsonine, causing slobbers’ symptoms and locoism of grazing animals, respectively. The genetics of this important fungus is poorly understood. This work aimed to develop ...

Fishing for Features

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

Heredia-Langner, Alejandro; Cort, John; Bailey, Vanessa

2016-07-21

The Fishing for Features Signature Discovery project developed a framework for discovering signature features in challenging environments involving large and complex data sets or where phenomena may be poorly characterized or understood. Researchers at PNNL have applied the framework to the optimization of biofuels blending and to discover signatures of climate change on microbial soil communities.

Teaching the Role of Mitochondrial Transport in Energy Metabolism

ERIC Educational Resources Information Center

Passarella, Salvatore; Atlante, Anna

2007-01-01

Studies from our laboratories over recent years have uncovered the existence, and established the properties of a variety of mitochondrial transporters. The properties of these transporters throw light on a variety of biochemical phenomena that were previously poorly understood. In particular the role of mitochondrial transport in energy…

Tiered Pricing: Implications for Library Collections

ERIC Educational Resources Information Center

Hahn, Karla

2005-01-01

In recent years an increasing number of publishers have adopted tiered pricing of journals. The design and implications of tiered-pricing models, however, are poorly understood. Tiered pricing can be modeled using several variables. A survey of current tiered-pricing models documents the range of key variables used. A sensitivity analysis…

Feeding Patterns and Emotional Care in Breastfed Infants

ERIC Educational Resources Information Center

Smith, Julie P.; Ellwood, Mark

2011-01-01

A number of studies have suggested breastfed infants have improved bonding and attachment or cognitive development outcomes. However, mechanisms by which these differences might develop are poorly understood. We used maternal time use data to examine whether exclusively breastfeeding mothers spend more time in close interactive behaviors with…

AGING AND LIFE-STAGE SUSCEPTIBILITY: TOLUENE EFFECTS ON BRAIN OXIDATIVE STRESS PARAMETERS IN BROWN NORWAY RATS.

EPA Science Inventory

The influence of aging on susceptibility to environmental contaminants is poorly understood. The objectives of this study were to test whether oxidative stress (OS) is a potential toxicity pathway following toluene exposure and to determine if these effects are age-dependent. We ...

Altered belowground carbon cycling following land use change to perennial bioenergy crops

USDA-ARS?s Scientific Manuscript database

Belowground carbon (C) dynamics of terrestrial ecosystems play an important role in the global C cycle and thereby in climate regulation, yet remain poorly understood. Globally, land use change is a major driver of changes in belowground C storage; in general, land clearing and tillage for agricult...

Measuring and Inducing Brain Plasticity in Chronic Aphasia

ERIC Educational Resources Information Center

Fridriksson, Julius

2011-01-01

Brain plasticity associated with anomia recovery in aphasia is poorly understood. Here, I review four recent studies from my lab that focused on brain modulation associated with long-term anomia outcome, its behavioral treatment, and the use of transcranial brain stimulation to enhance anomia treatment success in individuals with chronic aphasia…

Adaptation of neuronal signaling and cell stress response pathways in a multigenic response of Drosophila melanogaster to DDT selection

USDA-ARS?s Scientific Manuscript database

The adaptation of insect populations to insecticidal control is a continual threat human health and sustainable agriculture practices, but many complex genomic mechanisms involved remain poorly understood. A systems approach was applied to investigate the interconnections between structural and func...

Life cycle expression analysis of three cell wall degradation-related genes in ethylene-treated grass

USDA-ARS?s Scientific Manuscript database

Ethylene regulates multiple developmental processes during a plant life cycle, but the effect of ethylene on the upregulation of senescence-, stress-, and post-harvest-related genes in forage grasses is poorly understood. In this work, we used quantitative PCR to determine whether ethylene applicat...

Deficit irrigation practices may alter Vitis vinifera L. resistance to cold injury: Empirical evidence from the field

USDA-ARS?s Scientific Manuscript database

Deficit irrigation reduces seasonal carbohydrate supply and decreases starch concentrations in vegetative tissues. The specific role of starch metabolism in conferring tolerance to cold is still poorly understood. A decrease in cold tolerance after sequential years of deficit irrigation would limit ...

Prevalence of obesity: A public health problem poorly understood

USDA-ARS?s Scientific Manuscript database

This review article discusses the Dietary Guidelines for Americans in support of a total diet approach to achieving diet and health goals, especially as they relate to the obesity epidemic. However, some scientists and organizations have identified one food, food group, or nutrient as the cause of t...

A Qualitative Approach to Understanding Audience's Perceptions of Creativity in Online Advertising

ERIC Educational Resources Information Center

McStay, Andrew

2010-01-01

In this paper I seek to inquire upon audience's perceptions of creativity in online advertising--a heretofore poorly understood area. This paper initially outlines current academic understanding of creativity in online advertising, mainly derived from quantitative assessments. It then advances a qualitative methodology including diary-interviews…

Secondary organic aerosol formation from fossil fuel sources contribute majority of summertime organic mass at Bakersfield

EPA Science Inventory

Secondary organic aerosols (SOA), known to form in the atmosphere from oxidation of volatile organic compounds (VOCs) emitted by anthropogenic and biogenic sources, are a poorly understood but substantial component of atmospheric particles. In this study, we examined the chemic...

Structuring Program Analysis for Educational Research.

ERIC Educational Resources Information Center

Levine, Donald M.

Education is too complex, multidimensional, and poorly understood to lend itself to a single cost/effectiveness criterion. Rather, analysts in the educational field seek to rank alternatives by their effectiveness, report separately on the cost implications, and leave the tradeoffs to the decisionmaker's judgment. In this context, a program is any…

Inhibition in Dot Comparison Tasks

ERIC Educational Resources Information Center

Clayton, Sarah; Gilmore, Camilla

2015-01-01

Dot comparison tasks are commonly used to index an individual's Approximate Number System (ANS) acuity, but the cognitive processes involved in completing these tasks are poorly understood. Here, we investigated how factors including numerosity ratio, set size and visual cues influence task performance. Forty-four children aged 7-9 years completed…

Social Attribution Processes and Comorbid Psychiatric Symptoms in Children with Asperger Syndrome

ERIC Educational Resources Information Center

Meyer, Jessica A.; Mundy, Peter C.; Van Hecke, Amy Vaughan; Durocher, Jennifer Stella

2006-01-01

The factors that place children with Asperger syndrome at risk for comorbid psychiatric symptoms, such as anxiety and depression, remain poorly understood. We investigated the possibility that the children's emotional and behavioral difficulties are associated with social information and attribution processing. Participants were children with…

What Is Lexical Proficiency? Some Answers from Computational Models of Speech Data

ERIC Educational Resources Information Center

Crossley, Scott A.; Salsbury, Tom; McNamara, Danielle S.; Jarvis, Scott

2011-01-01

Lexical proficiency, as a cognitive construct, is poorly understood. However, lexical proficiency is an important element of language proficiency and fluency, especially for second language (L2) learners. Lexical proficiency is also an important attribute of L2 academic achievement. Generally speaking, lexical proficiency comprises breadth of…

Exposure to pairs of Aeromonas strains enhances virulence in the Caenorhabditis elegans infection model

USDA-ARS?s Scientific Manuscript database

Aeromonad virulence remains poorly understood, and is difficult to predict from strain characteristics. In addition, infections are often polymicrobial (i.e., are mixed infections), and 5 -10% of such infections include two distinct aeromonads, which has an unknown impact on virulence. In this work,...

Rehabilitation Counseling Professional Associations: Membership, Membership Intentions, and Levels of Commitment among Rehabilitation Counseling Professionals

ERIC Educational Resources Information Center

Phillips, Brian N.

2011-01-01

Declining membership is a concerning, yet poorly understood issue affecting professional associations across many disciplines (Bauman, 2008). The discipline of rehabilitation counseling is experiencing membership decline even as the number of certified rehabilitation counselors continues to increase (Leahy, 2009). Little empirical research…

Contributions of hydrology to Vesicular Stomatitis Virus emergence in the Western United States

USDA-ARS?s Scientific Manuscript database

Relationships between environmental variables associated with the spread of vector-borne pathogens, such as RNA viruses transmitted to humans and animals, remain poorly understood. Vesicular stomatitis (VS) is caused by a vector-borne, zoonotic RNA virus (VSV), and is the most common vesicular dise...

Statistical Word Learning in Children with Autism Spectrum Disorder and Specific Language Impairment

ERIC Educational Resources Information Center

Haebig, Eileen; Saffran, Jenny R.; Ellis Weismer, Susan

2017-01-01

Background: Word learning is an important component of language development that influences child outcomes across multiple domains. Despite the importance of word knowledge, word-learning mechanisms are poorly understood in children with specific language impairment (SLI) and children with autism spectrum disorder (ASD). This study examined…

The role of CAX1 and CAX3 in elemental distribution and abundance in Arabidopsis seed

USDA-ARS?s Scientific Manuscript database

The ability to alter nutrient partitioning within plant cells is poorly understood. In Arabidopsis (Arabidopsis thaliana), a family of endomembrane cation exchangers (CAXs) transports Ca(2+) and other cations. However, experiments have not focused on how the distribution and partitioning of calcium ...

An Investigation of Factors Involved When Educational Psychologists sSupervise Other Professionals

ERIC Educational Resources Information Center

Callicott, Katie; Leadbetter, Jane

2013-01-01

Inter-professional supervision combines the social processes of supervision and multi-agency working: both complex and often poorly understood processes. This paper discusses the first author's research of inter-professional supervision, involving an educational psychologist (EP) supervising another professional and complements the recently…

Madrone duff and the natural regeneration of Douglas-fir.

Treesearch

Don Minore

1987-01-01

Excellent natural regeneration of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) often occurs under canopies of Pacific madrone (Arbutus menziesii Pursh), but the effects of madrone duff on regeneration are poorly understood. A field experiment was conducted in a thinned Douglas-fir stand in southwestern Oregon to see if...

Storage conditions affecting increase in falling number of soft red winter wheat grain

USDA-ARS?s Scientific Manuscript database

Falling number (FN) of wheat grain, a measure of preharvest sprouting, tends to increase during storage; however, grain and storage conditions that impact FN changes are poorly understood. Wheat grain samples of varying FN from several cultivars were obtained by malting, by incubating wheat stalks,...

Can Human Associated Bacteroides (HF183MGB) be used as a Pathogen Predictor in Urban Watersheds?

EPA Science Inventory

The fate and transport dynamics of fecal indicators and pathogenic microorganisms are poorly characterized in urban watersheds. Moreover, very little is understood about the actual relationship between fecal indicator bacteria (FIB) and the risk to public health. In this study we...

Vegetative biomass predicts inflorescence production along a CO2 concentration gradient in mesic grassland

USDA-ARS?s Scientific Manuscript database

Atmospheric CO2 concentration will likely exceed 500 uL L-1 by 2050, often increasing plant community productivity in part by increasing abundance of species favored by increased CA. Whether increased abundance translates to increased inflorescence production is poorly understood, and is important ...

Homing success in wintering sparrows

Treesearch

C. John Ralph; L. Richard Mewaldt

1976-01-01

The ability of birds to return "home" after displacement is generallywell known but poorly understood because of the multiplicity of variablesthat affect homing performance. These variables can include age andprevious experience of the bird, as well as the timing and distance of thedisplacement. The phenomenon of homing is also difficult to interpretbecause,...

TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

EPA Science Inventory

The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

Short-term Effects of Air Temperature on Blood Markers of Coagulation and Inflammation in Potentially Susceptible Individuals

EPA Science Inventory

Objectives: Changes in air temperature are associated with an increase in cardiovascular events, but the role of pro-coagulant and pro-inflammatory blood markers is still poorly understood. We investigated the association between air temperature and fibrinogen, plasminogen act...

Cardiomyopathy confers susceptibility to particulate matter-induced oxidative stress, vagal dominance, arrhythmia, pulmonary inflammation in heart failure-prone rats

EPA Science Inventory

Acute exposure to ambient fine particulate matter (PM2.5) is tied to cardiovascular morbidity and mortality, especially among those with prior cardiac injury. The mechanisms and pathophysiologic events precipitating these outcomes remain poorly understood but may involve inflamm...

Dysarthria and Friedreich's Ataxia: What Can Intelligibility Assessment Tell Us?

ERIC Educational Resources Information Center

Blaney, Bronagh; Hewlett, Nigel

2007-01-01

Background: Friedreich's ataxia is one of the most common hereditary disorders of the nervous system. Dysarthria is a pervasive symptom of Friedreich's ataxia, yet the clinical presentation of speech symptoms remains poorly understood, leaving clinicians without the evidence required to develop therapy interventions. Aims: The research reported…

Face Scanning Distinguishes Social from Communication Impairments in Autism

ERIC Educational Resources Information Center

Falck-Ytter, Terje; Fernell, Elisabeth; Gillberg, Christopher; Von Hofsten, Claes

2010-01-01

How closely related are the social and communicative impairments in Autism Spectrum Disorder (ASD)? Recent findings in typically developing children suggest that both types of impairment are highly heritable but have only moderate behavioural and genetic overlap. So far, their respective roles in social perception are poorly understood. Here we…

Regulating Approaches to Learning: Testing Learning Strategy Convergences across a Year at University

ERIC Educational Resources Information Center

Fryer, Luke K.; Vermunt, Jan D.

2018-01-01

Background: Contemporary models of student learning within higher education are often inclusive of processing and regulation strategies. Considerable research has examined their use over time and their (person-centred) convergence. The longitudinal stability/variability of learning strategy use, however, is poorly understood, but essential to…

Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna

USDA-ARS?s Scientific Manuscript database

The majority of research on savanna vegetation dynamics has focused on the coexistence of woody and herbaceous vegetation; interactions among woody plants in savannas are relatively poorly understood. We present data from a 10-year longitudinal study of spatially explicit growth patterns of woody ve...

Variable high pressure processing sensitivities for GII human noroviruses

USDA-ARS?s Scientific Manuscript database

Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is one of the most promising non-thermal technologies for decontamination of viral pathogens in foods. However, the survival of HuNoVs by HPP is poorly understood because these viruses cann...

High pressure treatment of human norovirus-like particles: factors affecting destruction efficacy

USDA-ARS?s Scientific Manuscript database

Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is considered a promising non-thermal technology to inactivate viral pathogens in foods. However, the effectiveness of HPP on inactivating HuNoV remains poorly understood because it cannot be...

The Reciprocity of "Imitative Learning" through Apprenticeship

ERIC Educational Resources Information Center

Chan, Selena

2017-01-01

Humans are proposed to have evolved to learn through observation, imitation and practice or mimesis. In this article, the contribution of imitation, as an important but poorly understood aspect of mimetic learning, is advocated to create affordances for dyadic learning. However, learning through imitation is often perceived with negative…

The Therapy Process Observational Coding System for Child Psychotherapy Strategies Scale

ERIC Educational Resources Information Center

McLeod, Bryce D.; Weisz, John R.

2010-01-01

Most everyday child and adolescent psychotherapy does not follow manuals that document the procedures. Consequently, usual clinical care has remained poorly understood and rarely studied. The Therapy Process Observational Coding System for Child Psychotherapy-Strategies scale (TPOCS-S) is an observational measure of youth psychotherapy procedures…

High School Dropout in Proximal Context: The Triggering Role of Stressful Life Events

ERIC Educational Resources Information Center

Dupéré, Véronique; Dion, Eric; Leventhal, Tama; Archambault, Isabelle; Crosnoe, Robert; Janosz, Michel

2018-01-01

Adolescents who drop out of high school experience enduring negative consequences across many domains. Yet, the circumstances triggering their departure are poorly understood. This study examined the precipitating role of recent psychosocial stressors by comparing three groups of Canadian high school students (52% boys; M[subscript…

Discrimination and Sleep: The Protective Role of School Belonging

ERIC Educational Resources Information Center

Huynh, Virginia W.; Gillen-O'Neel, Cari

2016-01-01

Ethnic minority adolescents experience certain sleep problems, yet factors that affect their sleep are poorly understood. This study examined the association between ethnic discrimination and sleep during adolescence and the extent to which perceived stress mediated these associations. This study also examined whether school belonging can protect…

Global diversity and geography of soil fungi

Treesearch

Leho Tedersoo; Mohammad Bahram; Sergei Põlme; Urmas Kõljalg; Nourou S. Yorou; Ravi Wijesundera; Luis Villarreal Ruiz; Aida M. Vasco-Palacios; Pham Quang Thu; Ave Suija; Matthew E. Smith; Cathy Sharp; Erki Saluveer; Alessandro Saitta; Miguel Rosas; Taavi Riit; David Ratkowsky; Karin Pritsch; Kadri Põldmaa; Meike Piepenbring; Cherdchai Phosri; Marko Peterson; Kaarin Parts; Kadri Pärtel; Eveli Otsing; Eduardo Nouhra; André L. Njouonkou; R. Henrik Nilsson; Luis N. Morgado; Jordan Mayor; Tom W. May; Luiza Majukim; D. Jean Lodge; Su See Lee; Karl-Henrik Larsson; Petr Kohout; Kentaro Hosaka; Indrek Hiiesalu; Terry W. Henkel; Helery Harend; Liang-dong Guo; Alina Greslebin; Gwen Gretlet; Jozsef Geml; Genevieve Gates; William Dunstan; Chris Dunk; Rein Drenkhan; John Dearnaley; André De Kesel; Tan Dang; Xin Chen; Franz Buegger; Francis Q. Brearley; Gregory Bonito; Sten Anslan; Sandra Abell; Kessy Abarenkov

2014-01-01

Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples,we demonstrate that fungal richness is decoupled from plant diversity.The plant-to-fungus richness ratio declines exponentially toward the poles....

Climate variability drives population cycling and synchrony

Treesearch

Lars Y. Pomara; Benjamin Zuckerberg

2017-01-01

Aim There is mounting concern that climate change will lead to the collapse of cyclic population dynamics, yet the influence of climate variability on population cycling remains poorly understood. We hypothesized that variability in survival and fecundity, driven by climate variability at different points in the life cycle, scales up from...

Mosquito host choices on livestock amplifiers of Rift Valley fever virus in Kenya

USDA-ARS?s Scientific Manuscript database

Animal hosts may vary in their attraction and acceptability as components of the host location process for assessing biting rates of vectors and risk of exposure to pathogens. However, these parameters remain poorly understood for mosquito vectors of the Rift Valley fever (RVF), an arboviral disease...

Dissecting genome-wide association signals for loss-of-function phenotypes in sorghum flavonoid pigmentation traits

USDA-ARS?s Scientific Manuscript database

Genome-wide association studies (GWAS) are a powerful method to dissect the genetic basis of traits, though in practice the effects of complex genetic architecture and population structure remain poorly understood. To compare mapping strategies we dissect the genetic control of flavonoid pigmentatio...

Is body size important? Seasonal changes in morphology in two grass-feeding Abacarus mites

USDA-ARS?s Scientific Manuscript database

Overwintering strategies in herbivorous mites (Acari: Eriophyoidea) are poorly understood. A study of two Abacarus spp., was conducted to compare body size parameters of adult females in different seasons. Mites of Abacarus n. sp. (under description) and A. lolli were sampled from Bromopsis inermis ...

Single Particulate SEM-EDX Analysis of Iron-Containing Coarse Particulate Matter in an Urban Environment: Sources and Distribution of Iron within Cleveland, Ohio

EPA Science Inventory

The physicochemical properties of coarse-mode, iron-containing particles, and their temporal and spatial distributions are poorly understood. Single particle analysis combining x-ray elemental mapping and computer-controlled scanning electron microscopy (CCSEM-EDX) of passively ...

Modeling Spatial and Temporal Aspects of Visual Backward Masking

ERIC Educational Resources Information Center

Hermens, Frouke; Luksys, Gediminas; Gerstner, Wulfram; Herzog, Michael H.; Ernst, Udo

2008-01-01

Visual backward masking is a versatile tool for understanding principles and limitations of visual information processing in the human brain. However, the mechanisms underlying masking are still poorly understood. In the current contribution, the authors show that a structurally simple mathematical model can explain many spatial and temporal…

Tackling the Difficulties in Learning Evolution: Effects of Adaptive Self-Explanation Prompts

ERIC Educational Resources Information Center

Neubrand, Charlotte; Harms, Ute

2017-01-01

Teaching and learning evolution is challenging. Biology education research shows that the underlying evolutionary concepts are poorly understood among students. This prevents a meaningful understanding of the central biological concepts. The instructional format of self-explanation prompts seems to be promising to respond to these difficulties.…

Environmental enteric dysfunction and growth failure/stunting in global child health

USDA-ARS?s Scientific Manuscript database

Approximately 25% of the world's children aged <5 years have stunted growth, which is associated with increased mortality, cognitive dysfunction, and loss of productivity. Reducing by 40% the number of stunted children is a global target for 2030. The pathogenesis of stunting is poorly understood. P...

Comparative analysis of gut microbiota of Culex restuans (Diptera: Culicidae) females from different parents

USDA-ARS?s Scientific Manuscript database

The potential for gut microbiota to impede or enhance pathogen transmission is well-documented but the factors that shape this microbiota in mosquito vectors are poorly understood. We characterized and compared the gut microbiota of adult females of Culex restuans Theobald from different parents. Cu...

The Role of the Basolateral Amygdala in Punishment

ERIC Educational Resources Information Center

Dit-Bressel, Philip Jean-Richard; McNally, Gavan P.

2015-01-01

Aversive stimuli not only support fear conditioning to their environmental antecedents, they also punish behaviors that cause their occurrence. The amygdala, especially the basolateral nucleus (BLA), has been critically implicated in Pavlovian fear learning but its role in punishment remains poorly understood. Here, we used a within-subjects…

Depression and Relational Health in Asian American and European American College Women

ERIC Educational Resources Information Center

Lund, Terese J.; Chan, Pauline; Liang, Belle

2014-01-01

Research consistently demonstrates elevated rates of depression among college-aged women, yet evidence of racial differences in depression among this population are poorly understood. Moreover, the correlates of depression among Asian American women are also understudied. In this exploratory analysis, we examined mean differences in depression…

Flexibility and extracellular opening determine the interaction between ligands and insect sulfakinin receptors

USDA-ARS?s Scientific Manuscript database

Despite their fundamental importance for growth, the mechanisms that regulate food intake are poorly understood. Our previous work demonstrated that insect sulfakinin (SK) signaling is involved in inhibiting feeding in an important model and pest insect, the red flour beetle Tribolium castaneum. B...

Soy protein isolate inhibits hepatic tumor promotion in mice fed a high-fat liquid diet

USDA-ARS?s Scientific Manuscript database

Alcoholic and nonalcoholic fatty liver disease are risk factors for development of hepatocellular carcinoma, but the underlying mechanisms are poorly understood. On the other hand, ingestion of soy-containing diets may oppose the development of certain cancers. We previously reported that replacing ...

Acute and Subchronic Toxicity of Inhaled Toluene in Male Long-Evans Rats: Oxidative Stress Markers in Brain

EPA Science Inventory

The effects of exposure to volatile organic compounds (VOCs), which are of concern to the EPA, are poorly understood, in part because of insufficient characterization of how human exposure duration impacts VOC effects. Two inhalation studies with multiple endpoints, one acute an...

The Importance of Allochthonous Subsidies to an Estuarine Food Web along a Salinity Gradient

EPA Science Inventory

Estuarine food webs function within a heterogeneous mosaic and are supported by a mix of primary producers from both local and distant sources. Processes governing the exchange and consumption of organic matter (OM), however, are poorly understood. To study the contribution of ...

Metabolic coevolution in the bacterial symbiosis of whiteflies and related plant sap-feeding insects

USDA-ARS?s Scientific Manuscript database

In animals dependent on intracellular bacteria with very small genomes, the host cell is adapted to support the function of its bacterial symbionts, but the molecular basis of these adaptations is poorly understood. We investigated the metabolic coevolution between the whitefly Bemisia tabaci and th...

How Do Teachers View Their Own Pedagogical Authority?

ERIC Educational Resources Information Center

Harjunen, Elina

2009-01-01

Authority, a fundamental part of the teaching-studying-learning process, is a problematic and poorly understood component of classroom life. It can be said, in practical terms, that pedagogical authority is constructed in classrooms, in teacher-student interaction and in the spirit of their physical presence, confidence, appreciation,…

Changes in Markers of Genotoxicity in Relation to Exposure to Disinfection By-Products in Swimming Pools

EPA Science Inventory

Exposure to disinfection by-products (DBPs) has been associated with cancer risk, but the mechanisms of action are poorly understood. A recent study found increased bladder cancer risk among subjects attending swimming pools, where uptake of DBPs, such as trihalomethanes (THMs) c...

Understanding the carotenoid biosynthetic pathway through observation of four color variants of developing watermelon (Citrullus lanatus (Thunb.) Matsum. & Nanai)

USDA-ARS?s Scientific Manuscript database

The carotenoid biosynthetic pathway regulatory mechanisms leading to lycopene accumulation are well defined in the model fruit, tomato (Lycopersicon esculentum L.). The regulatory mechanisms leading to accumulation of other carotenoids and flesh colors, however, are poorly understood. The variety ...

A COMPUTER-CONTROLLED SYSTEM FOR GENERATING UNIFORM SURFACE DEPOSITS TO STUDY THE TRANSPORT OF PARTICULATE MATTER

EPA Science Inventory

Improved methods for measuring and assessing microenvironmental exposure in individuals are needed. How human activities affect particulate matter in the personal cloud is poorly understood. A quality assurance tool to aid the study of particle transport mechanisms (e.g., re-en...

Luminal Starch Substrate "Brake" on Maltase-Glucoamylase Activity Is Located within the Glucoamylase Subunit

USDA-ARS?s Scientific Manuscript database

The detailed mechanistic aspects for the final starch digestion process leading to effective alpha-glucogenesis by the 2 mucosal alpha-glucosidases, human sucrase-isomaltase complex (SI) and human maltase-glucoamylase (MGAM), are poorly understood. This is due to the structural complexity and vast v...

Evidence of a sewer vapor transport pathway at the USEPA vapor intrusion research duplex

EPA Science Inventory

The role of sewer lines as preferential pathways for vapor intrusion is poorly understood. Although the importance of sewer lines for volatile organic compound (VOC) transport has been documented at a small number of sites with vapor intrusion, sewer lines are not routinely sampl...