2,080 research outputs found
Perception of Food Safety Risk from Animal Contact Questionnaire for Extension Audiences
Animal contact in public settings for both leisure and work increases the odds of infectious diseases. This circumstance is exacerbated by inadequate understanding of the connection between exposure to animals and food safety risks. The purpose of our research was to develop a survey for assessing adults\u27 perceptions of food safety risk from exposure to animals. Results of our study suggest that the survey has acceptable internal structure and reliability. It may prove useful to Extension professionals who are assessing the need for associated programming or seeking to track progress toward relevant outcomes
Age, Gender, and Socioeconomic Status Differences in Explicit and Implicit Beliefs About Effortlessly Perfect Self-Presentation
Feeling pressure to project an image of effortless perfection -- always appearing to perform with self-confidence and ease --- has been portrayed in the media as an increasingly common mental health vulnerability with potentially serious implications for college women. Despite this, almost no empirical research exists on effortlessly perfect self–presentation (EPSP) or demographic differences in it.
• Some recent research suggests that perfectionism is on the rise among young people (Curran & Hill, 2017), and that it is more associated with mental health problems among students with high rather than low socioeconomic status (Lyman & Luthar, 2014). However, these studies did not focus specifically on EPSP, which differs from more typical perfectionism in that it prohibits apparent effort or anxiety while striving for perfection. Of the two published studies on EPSP, one did not examine demographic differences (Flett et al., 2016) and the other found higher endorsement of EPSP among men than among women (Travers et al., 2016).
• Anonymous interviews we conducted about EPSP in 40 college students (Glazer et al., in prep) yielded very complex, self-contradictory responses suggesting that beliefs about EPSP may be characterized by stigma and ambivalence. For this reason we decided to focus the current study on indirect and implicit measures of EPSP.
• In this study, participants completed three new scales about EPSP, along with the two existing measures of this phenomenon, several mental health measures, and demographics questions. They also rated the perceived social status and self-esteem of two target individuals in a within-person experimental design
History of Glial Cell Line-Derived Neurotrophic Factor (GDNF) and Its Use for Spinal Cord Injury Repair
Following an initial mechanical insult, traumatic spinal cord injury (SCI) induces a secondary wave of injury, resulting in a toxic lesion environment inhibitory to axonal regeneration. This review focuses on the glial cell line-derived neurotrophic factor (GDNF) and its application, in combination with other factors and cell transplantations, for repairing the injured spinal cord. As studies of recent decades strongly suggest that combinational treatment approaches hold the greatest therapeutic potential for the central nervous system (CNS) trauma, future directions of combinational therapies will also be discussed
Bridging adaptive management and reinforcement learning for more robust decisions
From out-competing grandmasters in chess to informing high-stakes healthcare
decisions, emerging methods from artificial intelligence are increasingly
capable of making complex and strategic decisions in diverse, high-dimensional,
and uncertain situations. But can these methods help us devise robust
strategies for managing environmental systems under great uncertainty? Here we
explore how reinforcement learning, a subfield of artificial intelligence,
approaches decision problems through a lens similar to adaptive environmental
management: learning through experience to gradually improve decisions with
updated knowledge. We review where reinforcement learning (RL) holds promise
for improving evidence-informed adaptive management decisions even when
classical optimization methods are intractable. For example, model-free deep RL
might help identify quantitative decision strategies even when models are
nonidentifiable. Finally, we discuss technical and social issues that arise
when applying reinforcement learning to adaptive management problems in the
environmental domain. Our synthesis suggests that environmental management and
computer science can learn from one another about the practices, promises, and
perils of experience-based decision-making.Comment: In press at Philosophical Transactions of the Royal Society
Multiple Instance Learning for Heterogeneous Images: Training a CNN for Histopathology
Multiple instance (MI) learning with a convolutional neural network enables
end-to-end training in the presence of weak image-level labels. We propose a
new method for aggregating predictions from smaller regions of the image into
an image-level classification by using the quantile function. The quantile
function provides a more complete description of the heterogeneity within each
image, improving image-level classification. We also adapt image augmentation
to the MI framework by randomly selecting cropped regions on which to apply MI
aggregation during each epoch of training. This provides a mechanism to study
the importance of MI learning. We validate our method on five different
classification tasks for breast tumor histology and provide a visualization
method for interpreting local image classifications that could lead to future
insights into tumor heterogeneity
Determination of Endocannabinoid Receptor Antagonist SR141716 (Rimonabant) in Plasma by Liquid Chromatograph Tandem Mass Spectrometry
SR141716 (rimonabant) is an endocannabinoid receptor antagonist. Endocannabinoids are a class of chemicals that affect neurotransmission via G-protein coupled CB1 (brain) and CB2 (peripheral tissue) receptors. Numerous animal studies have shown that SR141716 binds with the CB1 receptor in the brain, resulting in several biological consequences including reduced alcohol intake and reward as well as reduced food consumption. In this work, an analytical method based on liquid chromatography and electrospray ionization tandem mass spectrometry (LC–ESI-MS/MS) has been developed and validated for the quantitative measurement of SR141716 in both human and rat plasma to support the investigation of this compound. A suitable internal standard (AM251) has been chosen and the experimental conditions have been optimized for the separation and detection of singly charged positive ions of SR141716 and the internal standard. A protein precipitation protocol has been developed for extraction of SR141716 and the internal standard from plasma samples. Quantitation was achieved using multiple-reaction-monitoring (MRM) mode for SR141716 (m/z 463 → m/z 363) and the internal standard (m/z 555 → m/z 455) and calibration curve over the concentration range of 5.00–1000 ng/ml was plotted using the peak-area ratio versus the concentration of SR141716 with a LOD and LLOQ of 1.09 and 3.62 ng/ml, respectively. The method developed has been used to analyze SR141716 in rat plasma samples from an animal study
Schwann cell coculture improves the therapeutic effect of bone marrow stromal cells on recovery in spinal cord-injured mice
Studies of bone marrow stromal cells (MSCs) transplanted into the spinal cord-injured rat give mixed results: some groups report improved locomotor recovery while others only demonstrate improved histological appearance of the lesion. These studies show no clear correlation between neurological improvements and MSC survival. We examined whether MSC survival in the injured spinal cord could be enhanced by closely matching donor and recipient mice for genetic background and marker gene expression and whether exposure of MSCs to a neural environment (Schwann cells) prior to transplantation would improve their survival or therapeutic effects. Mice underwent a clip compression spinal cord injury at the fourth thoracic level and cell transplantation 7 days later. Despite genetic matching of donors and recipients, MSC survival in the injured spinal cord was very poor (~1%). However, we noted improved locomotor recovery accompanied by improved histopathological appearance of the lesion in mice receiving MSC grafts. These mice had more white and gray matter sparing, laminin expression, Schwann cell infiltration, and preservation of neurofilament and 5-HT-positive fibers at and below the lesion. There was also decreased collagen and chondroitin sulphate proteoglycan deposition in the scar and macrophage activation in mice that received the MSC grafts. The Schwann cell cocultured MSCs had greater effects than untreated MSCs on all these indices of recovery. Analyses of chemokine and cytokine expression revealed that MSC/Schwann cell cocultures produced far less MCP-1 and IL-6 than MSCs or Schwann cells cultured alone. Thus, transplanted MSCs may improve recovery in spinal cord-injured mice through immunosuppressive effects that can be enhanced by a Schwann cell coculturing step. These results indicate that the temporary presence of MSCs in the injured cord is sufficient to alter the cascade of pathological events that normally occurs after spinal cord injury, generating a microenvironment that favors improved recovery. © 2011 Cognizant Comm. Corp
Sources of influence on pregnant women's preferred mode of delivery in Buenos Aires, Argentina
Background: Understanding influences on women's preferred delivery mode is vital for planning interventions to reduce cesarean rates and for ensuring that women receive correct information. Our objectives were to: determine if sources of information influencing a pregnant woman's preferred delivery mode and knowledge of cesarean indications differ by sociodemographic characteristics; to conduct a factor analysis of items related to information sources influencing this preference; and to determine if knowledge differs by information sources influencing this preference or their underlying latent constructs. Methods: Data from a prospective cohort study conducted in Buenos Aires was analyzed. Healthy nulliparous women aged 18-35, at >32Â weeks of gestation and with live, singleton pregnancies participated. The primary research questions were evaluated using Chi-square tests, factor analysis, logistic regression, and generalized estimating equations. Results: A total of 382 women participated in the study. Women of lower socioeconomic status were more influenced by people, magazines and TV/movies in their mode of delivery preferences, and had poorer knowledge of cesarean indications. Sources of influence for preferred delivery mode and factors derived in factor analysis were not associated with knowledge level when considered individually or together, or when adjusted for sociodemographic characteristics, or when accounting for clustering by the hospital sector (public or private). Conclusions: Higher socioeconomic status is associated with being less influenced by people and with better knowledge of indications for cesarean delivery. Knowledge of cesarean indications was not associated with the source of information about mode of delivery preferences.Fil: Amyx, Melissa Michele. University of Tulane; Estados UnidosFil: Gibbons, Luz. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Pque. Centenario. Centro de Investigaciones En EpidemiologĂa y Salud Publica. Instituto de Efectividad Clinica y Sanitaria. Centro de Investigaciones En EpidemiologĂa y Salud Publica.; ArgentinaFil: Xiong, Xu. University of Tulane; Estados UnidosFil: Mazzoni, Agustina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Pque. Centenario. Centro de Investigaciones En EpidemiologĂa y Salud Publica. Instituto de Efectividad Clinica y Sanitaria. Centro de Investigaciones En EpidemiologĂa y Salud Publica.; ArgentinaFil: Althabe, Fernando. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Pque. Centenario. Centro de Investigaciones En EpidemiologĂa y Salud Publica. Instituto de Efectividad Clinica y Sanitaria. Centro de Investigaciones En EpidemiologĂa y Salud Publica.; ArgentinaFil: Buekens, Pierre. University of Tulane; Estados UnidosFil: Belizan, Jose. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Pque. Centenario. Centro de Investigaciones En EpidemiologĂa y Salud Publica. Instituto de Efectividad Clinica y Sanitaria. Centro de Investigaciones En EpidemiologĂa y Salud Publica.; Argentin
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Membrane mediated motor kinetics in microtubule gliding assays.
Motor-based transport mechanisms are critical for a wide range of eukaryotic cell functions, including the transport of vesicle cargos over long distances. Our understanding of the factors that control and regulate motors when bound to a lipid substrate is however incomplete. We used microtubule gliding assays on a lipid bilayer substrate to investigate the role of membrane diffusion in kinesin-1 on/off binding kinetics and thereby transport velocity. Fluorescence imaging experiments demonstrate motor clustering on single microtubules due to membrane diffusion in the absence of ATP, followed by rapid ATP-induced dissociation during gliding. Our experimental data combined with analytical modeling show that the on/off binding kinetics of the motors are impacted by diffusion and, as a consequence, both the effective binding and unbinding rates for motors are much lower than the expected bare rates. Our results suggest that motor diffusion in the membrane can play a significant role in transport by impacting motor kinetics and can therefore function as a regulator of intracellular transport dynamics
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