508 research outputs found

    Feasibility Study of Waste Isolation and Characterization by Instrumental Methods

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    The original focus of this project was to develop an in house procedure for the recovery of commonly used science laboratory solvents consisting of Acetone, Ethyl (Ethanol) Alcohol, Hexane, Methanol and Hydrochloric Acid from everyday laboratory waste. However, the projects scope shifted a little further back to basics when it was discovered that Laboratory Waste Safety and Accounting practices were insufficient. It was assumed that identification of waste products was being recorded accurately. It became apparent with the very first waste bottle analysis that chemicals recorded on the standardized waste log sheets were not always what was in the waste bottles. Therefore the focus was changed to verify if the existing waste disposal procedures are properly being followed with the expectation that future ongoing experiments can focus on the original recovery aspect of the project. The experimental procedures of this project have zeroed in the Non-Halogenated and Halogenated labeled Waste. These chemicals have been chosen for the case study for the following reasons. These groups of chemicals: 1) Are a standard in numerous labs across the chemistry disciples. 2) Generate the largest volumes of waste. 3) Analysis can be conducted using currently available instrumentation. 4) Theoretically will provide quality standards of recovery The experimental procedures have been theorized and developed from various chemistry curriculums over the past 13 years from the perspective of the Lab Manager

    Sampled Policy Gradient for Learning to Play the Game Agar.io

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    In this paper, a new offline actor-critic learning algorithm is introduced: Sampled Policy Gradient (SPG). SPG samples in the action space to calculate an approximated policy gradient by using the critic to evaluate the samples. This sampling allows SPG to search the action-Q-value space more globally than deterministic policy gradient (DPG), enabling it to theoretically avoid more local optima. SPG is compared to Q-learning and the actor-critic algorithms CACLA and DPG in a pellet collection task and a self play environment in the game Agar.io. The online game Agar.io has become massively popular on the internet due to intuitive game design and the ability to instantly compete against players around the world. From the point of view of artificial intelligence this game is also very intriguing: The game has a continuous input and action space and allows to have diverse agents with complex strategies compete against each other. The experimental results show that Q-Learning and CACLA outperform a pre-programmed greedy bot in the pellet collection task, but all algorithms fail to outperform this bot in a fighting scenario. The SPG algorithm is analyzed to have great extendability through offline exploration and it matches DPG in performance even in its basic form without extensive sampling

    A toolset of functionalized porphyrins with different linker strategies for application in bioconjugation

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    The reaction of amines with pentafluorophenyl-substituted A3B-porphyrins has been used to obtain different useful reactive groups for further functionalization and/or conjugation of these porphyrins to other substrates or materials. Porphyrins with alkenyl, alkynyl, amino, azido, epoxide, hydroxyl, and maleimido groups have thus been synthesized. For the first time such functionalized porphyrins have been conjugated to hyperbranched polyglycerol (hPG) as a biocompatible carrier system for photodynamic therapy (PDT) using the copper(I)-catalyzed 1,3-dipolar cycloaddition (CuAAC). The photocytotoxicity of selected porphyrins as well as of the porphyrin-hPG- conjugates has been assessed in cellular assays with human epidermoid carcinoma A-253 and squamous carcinoma CAL-27 cells. For several biomedical applications a release of the active drug and/or fluorescent dye is desired. Therefore, additionally, the synthesis of A3B-porphyrins with cleavable linker moieties is presented, namely disulfide, cleavable in a reductive environment, and acetal linkers whose cleavage is pH triggered

    The normalization of sibling violence: Does gender and personal experience of violence influence perceptions of physical assault against siblings?

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    Despite its pervasive and detrimental nature, sibling violence (SV) remains marginalized as a harmless and inconsequential form of familial aggression. The present study investigates the extent to which perceptions of SV differ from those of other types of interpersonal violence. A total of 605 respondents (197 males, 408 females) read one of four hypothetical physical assault scenarios that varied according to perpetrator–victim relationship type (i.e., sibling vs. dating partner vs. peer vs. stranger) before completing a series of 24 attribution items. Respondents also reported on their own experiences of interpersonal violence during childhood. Exploratory factor analysis reduced 23 attribution items to three internally reliable factors reflecting perceived assault severity, victim culpability, and victim resistance ratings. A 4 × 2 MANCOVA—controlling for respondent age—revealed several significant effects. Overall, males deemed the assault less severe and the victim more culpable than did females. In addition, the sibling assault was deemed less severe compared to assault on either a dating partner or a stranger, with the victim of SV rated just as culpable as the victim of dating, peer, or stranger-perpetrated violence. Finally, respondents with more (frequent) experiences of childhood SV victimization perceived the hypothetical SV assault as being less severe, and victim more culpable, than respondents with no SV victimization. Results are discussed in the context of SV normalization. Methodological limitations and applications for current findings are also outlined

    The genetic factors of bilaterian evolution

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    The Cambrian explosion was a unique animal radiation ~540 million years ago that produced the full range of body plans across bilaterians. The genetic mechanisms underlying these events are unknown, leaving a fundamental question in evolutionary biology unanswered. Using large-scale comparative genomics and advanced orthology evaluation techniques, we identified 157 bilaterian-specific genes. They include the entire Nodal pathway, a key regulator of mesoderm development and left-right axis specification; components for nervous system development, including a suite of G protein-coupled receptors that control physiology and behaviour, the Robo-Slit midline repulsion system, and the neurotrophin signalling system; a high number of zinc finger transcription factors; and novel factors that previously escaped attention. Contradicting the current view, our study reveals that genes with bilaterian origin are robustly associated with key features in extant bilaterians, suggesting a causal relationship

    Finite-size scaling of the quasiespecies model

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    We use finite-size scaling to investigate the critical behavior of the quasiespecies model of molecular evolution in the single-sharp-peak replication landscape. This model exhibits a sharp threshold phenomenon at Q=Q_c=1/a, where Q is the probability of exact replication of a molecule of length L and a is the selective advantage of the master string. We investigate the sharpness of the threshold and find that its characteristic persist across a range of Q of order L^(-1) about Q_c. Furthermore, using the data collapsing method we show that the normalized mean Hamming distance between the master string and the entire population, as well as the properly scaled fluctuations around this mean value, follow universal forms in the critical region.Comment: 8 pages,tex. Submitted to Physical Review

    Science live: Surveying the landscape of live public science events

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    The field of informal science learning and communication is comprised of many sectors—after school programs, science center exhibitions and programs, television and film, print and new media, to name just a few. Each of these is understood to make unique contributions, present unique opportunities, and require unique support. Science Live began with the observation that it time to similarly acknowledge the practice of live public science events.Public science events are live, in-person programs designed to engage publics with science in a social context that is at least as meaningful as the content and messages delivered. The overall objective of Science Live is to support the development of a distinct professional sector based on live public science events so that the practitioners, researchers, and external supporters of this sector are able to maximize the beneficial impacts of events and widen participation in this activity.The following survey of the live public science events landscape is the product of a one-year, Phase I grant from the Science Learning+ funding program. This funding program has enabled Science Live to take a transatlantic approach, with an initial focus on fostering connections between the US and UK,and between practitioners and researchers.The following landscape survey is based on informal conversations, phone interviews following a research protocol, and two project convenings, one each in the US and UK. A total of 111 practitioners and researchers attended project convenings, and scores more were consulted by phone.The many quotes appearing in the following pages are taken directly from these conversations. This landscape survey seeks to summarize a year of dialogue, but is not explicitly endorsed by the many practitioners and researchers that participated.The world of live public science events is wide, varied, and rapidly changing. There is no way to represent the many initiatives that populate this remarkable landscape in a way that properly does each justice. Please see www.livescienceevents.org for links to participating programs, research,and sites for further exploration

    Brief report: Using global positioning system (GPS) enabled cell phones to examine adolescent travel patterns and time in proximity to alcohol outlets

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    As adolescents gain freedom to explore new environments unsupervised, more time in proximity to alcohol outlets may increase risks for alcohol and marijuana use. This pilot study: 1) Describes variations in adolescents' proximity to outlets by time of day and day of the week, 2) Examines variations in outlet proximity by drinking and marijuana use status, and 3) Tests feasibility of obtaining real-time data to study adolescent proximity to outlets. U.S. adolescents (N = 18) aged 16–17 (50% female) carried GPS-enabled smartphones for one week with their locations tracked. The geographic areas where adolescents spend time, activity spaces, were created by connecting GPS points sequentially and adding spatial buffers around routes. Proximity to outlets was greater during after school and evening hours. Drinkers and marijuana users were in proximity to outlets 1½ to 2 times more than non-users. Findings provide information about where adolescents spend time and times of greatest risk, informing prevention efforts

    The Purdue Extension and Indiana CTSI's Community Health Partnerships collaboration: An innovative, generalizable, state-wide model to help communities build a culture of health

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    The Indiana Clinical and Translational Sciences Institute's Community Engagement Partners-Purdue Extension collaborative model demonstrates tremendous potential for creating state-wide programmatic efforts and improvements in both the health culture and status of Indiana residents across the state. It can serve as a prototype not only for others interested in pursuing wide geographic health improvements through Clinical and Translational Sciences Award-Cooperative Extension partnerships but also for broader collaborations among United States Department of Agriculture, National Institutes of Health, Centers for Disease Control and Prevention, state and local health departments, and health foundation efforts to improve population health

    Visual Working Memory Recruits Two Functionally Distinct Alpha Rhythms in Posterior Cortex

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    Copyright © 2022 Rodriguez-Larios et al. Oscillatory activity in the human brain is dominated by posterior alpha oscillations (8–14 Hz), which have been shown to be functionally relevant in a wide variety of cognitive tasks. Although posterior alpha oscillations are commonly considered a single oscillator anchored at an individual alpha frequency (∼10 Hz), previous work suggests that individual alpha frequency reflects a spatial mixture of different brain rhythms. In this study, we assess whether independent component analysis (ICA) can disentangle functionally distinct posterior alpha rhythms in the context of visual short-term memory retention. Magnetoencephalography (MEG) was recorded in 33 subjects while performing a visual working memory task. Group analysis at sensor level suggested the existence of a single posterior alpha oscillator that increases in power and decreases in frequency during memory retention. Conversely, single-subject analysis of independent components revealed the existence of two dissociable alpha rhythms: one that increases in power during memory retention (Alpha1) and another one that decreases in power (Alpha2). Alpha1 and Alpha2 rhythms were differentially modulated by the presence of visual distractors (Alpha1 increased in power while Alpha2 decreased) and had an opposite relationship with accuracy (positive for Alpha1 and negative for Alpha2). In addition, Alpha1 rhythms showed a lower peak frequency, a narrower peak width, a greater relative peak amplitude and a more central source than Alpha2 rhythms. Together, our results demonstrate that modulations in posterior alpha oscillations during short-term memory retention reflect the dynamics of at least two distinct brain rhythms with different functions and spatiospectral characteristics.The Netherlands Organisation for Scientific Research (NWO) Vidi Grant 016.Vidi.185.137; National Institutes of Health Grant R01-MH123679
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