921 research outputs found

    Imaging methods for understanding and improving visual training in the geosciences

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    Experience in the field is a critical educational component of every student studying geology. However, it is typically difficult to ensure that every student gets the necessary experience because of monetary and scheduling limitations. Thus, we proposed to create a virtual field trip based off of an existing 10-day field trip to California taken as part of an undergraduate geology course at the University of Rochester. To assess the effectiveness of this approach, we also proposed to analyze the learning and observation processes of both students and experts during the real and virtual field trips. At sites intended for inclusion in the virtual field trip, we captured gigapixel resolution panoramas by taking hundreds of images using custom built robotic imaging systems. We gathered data to analyze the learning process by fitting each geology student and expert with a portable eye- tracking system that records a video of their eye movements and a video of the scene they are observing. An important component of analyzing the eye-tracking data requires mapping the gaze of each observer into a common reference frame. We have made progress towards developing a software tool that helps automate this procedure by using image feature tracking and registration methods to map the scene video frames from each eye-tracker onto a reference panorama for each site. For the purpose of creating a virtual field trip, we have a large scale semi-immersive display system that consists of four tiled projectors, which have been colorimetrically and photometrically calibrated, and a curved widescreen display surface. We use this system to present the previously captured panoramas, which simulates the experience of visiting the sites in person. In terms of broader geology education and outreach, we have created an interactive website that uses Google Earth as the interface for visually exploring the panoramas captured for each site

    A Hybrid Cellular Automata Model for the Role of Reactive Oxygen Species in Novel Tumour Treatments Strategies

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    Cancer is a disease that entails uncontrolled proliferation and a disruption of tissue function that often results in a poor clinical outcome. Furthermore, it has continued to elude any universal treatment or cure in part because of the complexity seen across multiple spatial and temporal scales. In silico modelling techniques, such as hybrid cellular automata (HCA), provide an inexpensive and versatile means of incorporating experimental factors that are either impossible or infeasible to control and investigate when using in vivo or in vivo experimental settings. Reactive oxygen species (ROS) are critical molecules in cellular processes and have been demonstrated to induce effects on cellular processes ranging from proliferation to metabolic reprogramming and cell death. Dichloroacetate (DCA) and intravenous vitamin C (VC) are two proposed treatments that induce death via ROS and have begun to gain attention from the oncology community for their relative lack of toxicity and potential efficacy. Thus, investigating a HCA model to optimize their effects can be influential in the success of these drugs. The model employed uses discrete rules for the evolution of each cell, and continuous equations for diffusible elements so that multiple time scales may be incorporated effectively. The implementation of components such as necrotic cell removal and accurate pharmacokinetics in the model has a considerable effect on outcome of VC treatment individually and in combination. Furthermore, VC is most effective at removing tumour cells entirely when its plasma concentration is maximized, while DCA’s cytotoxic action plateaus as its concentration increases and is only effective at removing cell types that exist within the interior of the tumour

    The effects of ractopamine-HCl (optaflexx) on performance, carcass characteristics, and meat quality of finishing feedlot heifers

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    Beta-adrenergic agonists are commonly used in livestock production to accelerate growth by enhancing lean tissue gain. These compounds repartition nutrients away from fat deposition and toward protein accretion. Generally, increased growth is associated with ractopamine feeding, which improves feed conversion and increases body weight gain. However, little data exists on the effects of ractopamine-HCl on live performance or carcass characteristics of beef heifers. Data released from Elanco Animal Health indicate that differences between gender may exist in response to ractopamine, and therefore appropriate strategies for the administration of this compound must be defined for heifers independent of those for steers. The objective of this study was to determine the effects of Optaflexx, when fed for different dosages over different durations, on finishing heifer performance

    Evolution of the Toxins Muscarine and Psilocybin in a Family of Mushroom-Forming Fungi

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    Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10–20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa. DOI: 10.1371/journal.pone.006464

    Evolution of the Toxins Muscarine and Psilocybin in a Family of Mushroom-Forming Fungi

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    Mushroom-forming fungi produce a wide array of toxic alkaloids. However, evolutionary analyses aimed at exploring the evolution of muscarine, a toxin that stimulates the parasympathetic nervous system, and psilocybin, a hallucinogen, have never been performed. The known taxonomic distribution of muscarine within the Inocybaceae is limited, based only on assays of species from temperate regions of the northern hemisphere. Here, we present a review of muscarine and psilocybin assays performed on species of Inocybaceae during the last fifty years. To supplement these results, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to determine whether muscarine was present in 30 new samples of Inocybaceae, the majority of which have not been previously assayed or that originated from either the tropics or temperate regions of the southern hemisphere. Our main objective is to test the hypothesis that the presence of muscarine is a shared ancestral feature of the Inocybaceae. In addition, we also test whether species of Inocyabceae that produce psilocybin are monophyletic. Our findings suggest otherwise. Muscarine has evolved independently on several occasions, together with several losses. We also detect at least two independent transitions of muscarine-free lineages to psilocybin-producing states. Although not ancestral for the family as a whole, muscarine is a shared derived trait for an inclusive clade containing three of the seven major lineages of Inocybaceae (the Inocybe, Nothocybe, and Pseudosperma clades), the common ancestor of which may have evolved ca. 60 million years ago. Thus, muscarine represents a conserved trait followed by several recent losses. Transitions to psilocybin from muscarine-producing ancestors occurred more recently between 10–20 million years ago after muscarine loss in two separate lineages. Statistical analyses firmly reject a single origin of muscarine-producing taxa. DOI: 10.1371/journal.pone.006464

    Gray Matter Volumes Discriminate Cognitively Impaired and Unimpaired People with HIV

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    BACKGROUND: Current diagnostic criteria of HIV-associated neurocognitive disorders (HAND) rely on neuropsychological assessments. The aim of this study was to evaluate if gray matter volumes (GMV) can distinguish people with HAND, neurocognitively unimpaired people with HIV (unimpaired PWH), and uninfected controls using linear discriminant analyses. METHODS: A total of 231 participants, including 110 PWH and 121 uninfected controls, completed a neuropsychological assessment and an MRI protocol. Among PWH, HAND (n = 48) and unimpaired PWH (n = 62) designations were determined using the widely accepted Frascati criteria. We then assessed the extent to which GMV, corrected for intracranial volume, could accurately distinguish the three groups using linear discriminant analysis. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, area under the curve (AUC), and accuracy were computed for each model using the classification results based on GMV compared to the neuropsychological assessment. RESULTS: The best performing model was comprised of bilaterally combined GMV and was stratified by sex. Among males, sensitivity was 85.2% (95% CI: 66.3%-95.8%), specificity was 97.0% (95% CI: 91.6%-99.4%), and the AUC was 0.91 (95% CI: 0.83-0.99). Among females, sensitivity was 100.0% (95% CI: 83.9%-100.0%), specificity was 98.8% (95% CI: 93.4%-100.0%), and the AUC was 0.99 (95% CI: 0.98-1.00). CONCLUSIONS: GMV accurately discriminated HAND from unimpaired PWH and controls. Measures of GMV may be highly sensitive to HAND, and revisions to the Frascati criteria should consider including GMV in conjunction with a neuropsychological assessment to diagnose HAND

    What asteroseismology can do for exoplanets

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    We describe three useful applications of asteroseismology in the context of exoplanet science: (1) the detailed characterisation of exoplanet host stars; (2) the measurement of stellar inclinations; and (3) the determination of orbital eccentricity from transit duration making use of asteroseismic stellar densities. We do so using the example system Kepler-410 (Van Eylen et al. 2014). This is one of the brightest (V = 9.4) Kepler exoplanet host stars, containing a small (2.8 Rearth) transiting planet in a long orbit (17.8 days), and one or more additional non-transiting planets as indicated by transit timing variations. The validation of Kepler-410 (KOI-42) was complicated due to the presence of a companion star, and the planetary nature of the system was confirmed after analyzing a Spitzer transit observation as well as ground-based follow-up observations.Comment: 4 pages, Proceedings of the CoRoT Symposium 3 / Kepler KASC-7 joint meeting, Toulouse, 7-11 July 2014. To be published by EPJ Web of Conference

    AFLES’s Inspirations and Its ASEAN Youth Community Development (ASEAN Future Leaders Summit)

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    This article is discussing about experiences of conducting AFLES (ASEAN Future Leaders Summit), which started in 2013 with the collaboration between Universiti Sains Malaysia (USM) and Prince of Songkla University, Thailand (PSU). AFLES is an action-packed summit meant for ASEAN youth with exciting forums, discussions, lectures, team-work, outdoor activities, community work, services, sight-seeing and cultural events. With the main objectives of developing ASEAN youth community in terms of their leadership skills and to serve as a platform for ASEAN youth to get together and connected to each other, AFLES for the last sixth term (2013-2018), has evolved to be a looking after summit to participate by ASEAN university student leaders. Over the years AFLES has developed and progressed with a few more collaborators, namely AKEPT (Malaysia Higher Education Leadership Academy), UiTM (Universiti Teknologi MARA), UUM (Universiti Utara Malaysia) and UKM (Universiti Kebangsaan Malaysia). Community development, ASEAN unity and harmonization, and Internationalization of Higher Education Institutions in ASEAN are discussed regarding to the sustainability of AFLES in conducting an international program for youth across ASEAN region
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