360 research outputs found

    High Throughput Modeling of Post-Traumatic Stress Disorder

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    poster abstractCombat veterans, have higher instances of PTSD only about 7% of the US population will develop this pathology. The low ratio of individuals exposed to a traumatic event to individuals who develop PTSD (75%: 7%) highlights that most individuals can successfully cope with the emotional aftermath of stressful situations. Individuals suffering from PTSD seem to have a fundamental impairment in this stress coping ability, or the ability to progress past the event. It is common for people to report PTSD like symptoms in the following days or weeks after a traumatic event and is considered to be perfectly natural. It is not until these symptoms persist for more than a month before a diagnosis of PTSD can be made. Given the incidence of natural disasters, violent/sexual assaults, and other traumatic incidents in the United States, there is a great need to develop tools directed at studying PTSD. Preclinical modeling of PTSD can be achieved by using Pavlovian fear conditioning where a rat associates a mild foot shock with neutral tone. Details associated with a past traumatic can elicit a fearful reaction in PTSD, the tone previously paired with foot shock can elicit a fearful response in a rat, when not presented with a shock. The ability of an animal to disassociate the tone from the foot shock can be achieved by repeated exposure to the tone in the absence of the shock. After this repeated exposure to the tone the animal learns to “extinguish” the previous fearful memory of the footshock is very relevant to PTSD which is characterized by fearful memories that persist for an extended period of time. In the current work, we characterize a new apparatus for fear conditioning / extinction in rats that allows for the running of multiple animals paired with automated behavioral scoring

    Remote Sensing Of The Cryosphere In High Mountain Asia

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    High Mountain Asia (HMA), often referred to as the "third pole" of the world because its high elevation glaciers, contains the largest amount of fresh water outside the polar ice sheets. The region's hydrology is strongly controlled by variations in the timing and distribution of runoff from snow and glacier melt. Recent improvements in remote sensing technologies and atmospheric / land surface models provides new approaches for assessing the HMA cryosphere. A recently-funded NASA program aims to apply these tools to advance understanding of HMA cryospheric processes. Here we present an overview of planned team activities during the three-year project

    Nuance and behavioral cogency: How the Visible Burrow System inspired the Stress-Alternatives Model and conceptualization of the continuum of anxiety

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    By creating the Visible Burrow System (VBS) Bob Blanchard found a way to study the interaction of genetics, physiology, environment, and adaptive significance in a model with broad validity. The VBS changed the way we think about anxiety and affective disorders by allowing the mechanisms which control them to be observed in a dynamic setting. Critically, Blanchard used the VBS and other models to show how behavioral systems like defense are dependent upon context and behavioral elements unique to the individual. Inspired by the VBS, we developed a Stress Alternatives Model (SAM) to further explore the multifaceted dynamics of the stress response with a dichotomous choice condition. Like the VBS, the SAM is a naturalistic model built upon risk assessment and defensive behavior, but with a choice of response: escape or submission to a large conspecific aggressor. The anxiety of novelty during the first escape must be weighed against fear of the aggressor, and a decision must be made. Both outcomes are adaptively significant, evidenced by a 50/50 split in outcome across several study systems. By manipulating the variables of the SAM, we show that a gradient of anxiety exists that spans the contextual settings of escaping an open field, escaping from aggression, and submitting to aggression. These findings correspond with increasing levels of corticosterone and increasing levels of NPS and BDNF in the central amygdala as the context changes.Whereas some anxiolytics were able to reduce the latency to escape for some animals, only with the potent anxiolytic drug antalarmin (CRF1R-blocker) and the anxiogenic drug yohimbine (α2 antagonist) were we able to reverse the outcome for a substantial proportion of individuals. Our findings promote a novel method for modeling anxiety, offering a distinction between low-and-high levels, and accounting for individual variability. The translational value of the VBS is immeasurable, and it guided us and many other researchers to seek potential clinical solutions through a deeper understanding of regional neurochemistry and gene expression in concert with an ecological behavioral model

    Maximal regularity for non-autonomous equations with measurable dependence on time

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    In this paper we study maximal LpL^p-regularity for evolution equations with time-dependent operators AA. We merely assume a measurable dependence on time. In the first part of the paper we present a new sufficient condition for the LpL^p-boundedness of a class of vector-valued singular integrals which does not rely on H\"ormander conditions in the time variable. This is then used to develop an abstract operator-theoretic approach to maximal regularity. The results are applied to the case of mm-th order elliptic operators AA with time and space-dependent coefficients. Here the highest order coefficients are assumed to be measurable in time and continuous in the space variables. This results in an Lp(Lq)L^p(L^q)-theory for such equations for p,q∈(1,∞)p,q\in (1, \infty). In the final section we extend a well-posedness result for quasilinear equations to the time-dependent setting. Here we give an example of a nonlinear parabolic PDE to which the result can be applied.Comment: Application to a quasilinear equation added. Accepted for publication in Potential Analysi

    Integrated metabolomics identifies CYP72A67 and CYP72A68 oxidases in the biosynthesis of Medicago truncatula oleanate sapogenins

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    Introduction: Triterpene saponins are important bioactive plant natural products found in many plant families including the Leguminosae. Objectives: We characterize two Medicago truncatula cytochrome P450 enzymes, MtCYP72A67 and MtCYP72A68, involved in saponin biosynthesis including both in vitro and in planta evidence. Methods: UHPLC-(-)ESI-QToF-MS was used to profile saponin accumulation across a collection of 106 M. truncatula ecotypes. The profiling results identified numerous ecotypes with high and low saponin accumulation in root and aerial tissues. Four ecotypes with significant differential saponin content in the root and/or aerial tissues were selected, and correlated gene expression profiling was performed. Results: Correlation analyses between gene expression and saponin accumulation revealed high correlations between saponin content with gene expression of -amyrin synthase, MtCYP716A12, and two cytochromes P450 genes, MtCYP72A67 and MtCYP72A68. In vivo and in vitro biochemical assays using yeast microsomes containing MtCYP72A67 revealed hydroxylase activity for carbon 2 of oleanolic acid and hederagenin. This finding was supported by functional characterization of MtCYP72A67 using RNAi-mediated gene silencing in M. truncatula hairy roots, which revealed a significant reduction of 2-hydroxylated sapogenins. In vivo and in vitro assays with MtCYP72A68 produced in yeast showed multifunctional oxidase activity for carbon 23 of oleanolic acid and hederagenin. These findings were supported by overexpression of MtCYP72A68 in M. truncatula hairy roots, which revealed significant increases of oleanolic acid, 2-hydroxyoleanolic acid, hederagenin and total saponin levels. Conclusions: The cumulative data support that MtCYP72A68 is a multisubstrate, multifunctional oxidase and MtCYP72A67 is a 2-hydroxylase, both of which function during the early steps of triterpene-oleanate sapogenin biosynthesis

    Effects of acute fatigue on the volitional and magnetically-evoked electromechanical delay of the knee flexors in males and females

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    Neuromuscular performance capabilities, including those measured by evoked responses, may be adversely affected by fatigue; however, the capability of the neuromuscular system to initiate muscle force rapidly under these circumstances is yet to be established. Sex-differences in the acute responses of neuromuscular performance to exercise stress may be linked to evidence that females are much more vulnerable to ACL injury than males. Optimal functioning of the knee flexors is paramount to the dynamic stabilisation of the knee joint, therefore the aim of this investigation was to examine the effects of acute maximal intensity fatiguing exercise on the voluntary and magnetically-evoked electromechanical delay in the knee flexors of males and females. Knee flexor volitional and magnetically-evoked neuromuscular performance was assessed in seven male and nine females prior to and immediately after: (i) an intervention condition comprising a fatigue trial of 30-seconds maximal static exercise of the knee flexors, (ii) a control condition consisting of no exercise. The results showed that the fatigue intervention was associated with a substantive reduction in volitional peak force (PFV) that was greater in males compared to females (15.0%, 10.2%, respectively, p < 0.01) and impairment to volitional electromechanical delay (EMDV) in females exclusively (19.3%, p < 0.05). Similar improvements in magnetically-evoked electromechanical delay in males and females following fatigue (21%, p < 0.001), however, may suggest a vital facilitatory mechanism to overcome the effects of impaired voluntary capabilities, and a faster neuromuscular response that can be deployed during critical times to protect the joint system

    The Origins of Novel Protein Interactions during Animal Opsin Evolution

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    Background. Biologists are gaining an increased understanding of the genetic bases of phenotypic change during evolution. Nevertheless, the origins of phenotypes mediated by novel protein-protein interactions remain largely undocumented. Methodology/Principle Findings. Here we analyze the evolution of opsin visual pigment proteins from the genomes of early branching animals, including a new class of opsins from Cnidaria. We combine these data with existing knowledge of the molecular basis of opsin function in a rigorous phylogenetic framework. We identify adaptive amino acid substitutions in duplicated opsin genes that correlate with a diversification of physiological pathways mediated by different protein-protein interactions. Conclusions/Significance. This study documents how gene duplication events early in the history of animals followed by adaptive structural mutations increased organismal complexity by adding novel protein-protein interactions that underlie different physiological pathways. These pathways are central to vision and other photo-reactive phenotypes in most extant animals. Similar evolutionary processes may have been a work in generating other metazoan sensory systems and other physiological processes mediated by signal transduction

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    A Reappraisal of Children’s ‘Potential’

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    What does it mean for a child to fulfil his or her potential? This article explores the contexts and implications of the much-used concept of potential in educational discourses. We claim that many of the popular, political and educational uses of the term in relation to childhood have a problematic blind spot: interpersonality, and the necessary coexistence for the concept to be receivable of all children’s ‘potentials’. Rather than advocating abandoning the term—a futile gesture given its emotive force—we argue that the concept of children’s potential must be profoundly rethought to be workable as a philosophical notion in education. In an era marked by the unspoken assumption that ‘unlimited potential’ is always a good thing, we argue that it might be necessary to think about the limitations of the notion of individual potential; namely, the moment when it comes into contact with other people’s projects. We propose a conceptualisation of potential as the negotiated, situated, ever-changing creation of a group of individuals, in a process marked by conflict, and which remains essentially difficult.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s11217-016-9508-
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