612 research outputs found

    Undergraduate students use moral reasoning and belief in genetic determinism in response to a CRISPR/Cas9 socioscientific Issue.

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    This dissertation explores how students reason about genetic engineering socioscientific issues (SSIs) related to a recently developed, powerful genome editing technology called CRISPR/Cas9. It is divided into three chapters. Chapter One describes an exploratory study that characterized students’ moral reasoning using a sociocultural theoretical framework. I used content analysis and logistic regression to investigate how academic and social factors influenced moral reasoning. Students generally opposed the use of CRISPR/Cas9 technology for non-medical enhancements, and the moral considerations used were influenced by genetics knowledge level and demographic variables such as gender and socio-economic status. Further investigation of moral perspectives for students from traditionally marginalized groups should be considered so they can be integrated into curricula to foster diverse classroom environments. Chapter Two describes how I investigated belief in genetic determinism, a dimension of genetic essentialism that is inconsistent with the current multifactorial model of genetics because it overestimates the impact genes have on character expression, while underestimating environmental impacts. Quantitative measures of belief in genetic determinism from questionnaires indicated students held an accurate understanding of genetics and low-to-medium BGD, but BGD was widespread in students’ writing. Although biology students were more likely to express BGD, non-major students were more likely to display one-gene-one-trait misconceptions. These results underscore the need to alter genetics instruction so that it reflects the ongoing paradigm shift of genetics understanding. Chapter Three describes a practitioner study that used a jigsaw activity to engage students in a recent, real-life CRISPR/Cas9 research study as an SSI. The purpose was to teach students about bioethics without promoting the use of BGD. After the lesson, students demonstrated an appreciation for bioethics related to the case study they evaluated and acknowledged environmental influences on complex characteristics. The developed lesson is an ideal method for integrating SSIs and bioethics into undergraduate biology curricula

    Acute Myeloid Leukemia and Fatal Scedosporium prolificans Sepsis After Eculizumab Treatment for Paroxysmal Nocturnal Hemoglobinuria: a Case Report

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    Eculizumab has become the standard of care for patients with paroxysmal nocturnal hemoglobinuria (PNH). As more patients are treated, the long-term outcomes of these patients will become apparent. We recently treated a patient who developed PNH in the setting of aplastic anemia. The patient developed acute myeloid leukemia less than three years after initiating eculizumab. The patient also died suddenly from Scedosporium sepsis during induction therapy. This patient\u27s course seemed more aggressive than would be expected. The possible effect of complement blockade is discussed

    U.S. Army Corps of Engineers Freshwater Harmful Algal Bloom Research & Development Initiative

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    Freshwater Harmful Algal Blooms (HABs) are particularly impactful to the U.S. Army Corps of Engineers (USACE), which manages vast freshwater resources and waterways that provide a variety of services including navigation, flood risk reduction, recreation, fish and wildlife management, as well as potable water supply. The Water Resources Development Act of 2018 (WRDA 2018) authorized the U.S. Army Engineer Research Development Center (USACE-ERDC) to implement a 5-year technology demonstration program to deliver scalable technologies for HAB prevention, detection and management that will reduce HAB frequency and effects to our nation’s freshwater resources across scales (e.g. small waterbodies to river reaches), ecoregions (e.g. subtropical Florida to temperate Ohio and New York), and system types (e.g. reservoirs, riverine, lakes). The USACE-ERDC HAB Research & Development (R&D) portfolio features a range of HAB-combatting methods, models, and technologies that may be used alone or in combination to effectively reduce HAB frequency and impacts to water resource development projects across the nation. An overview of USACE-ERDC sponsored HAB R&D projects will highlight the range of HAB methods, models, and technologies in development, and will provide an opportunity to engage with federal, state, local, and university partners

    Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens

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    Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators

    Unsupervised online activity discovery using temporal behaviour assumption

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    We present a novel unsupervised approach, UnADevs, for discovering activity clusters corresponding to periodic and stationary activities in streaming sensor data. Such activities usually last for some time, which is exploited by our method; it includes mechanisms to regulate sensitivity to brief outliers and can discover multiple clusters overlapping in time to better deal with deviations from nominal behaviour. The method was evaluated on two activity datasets containing large number of activities (14 and 33 respectively) against online agglomerative clustering and DBSCAN. In a multi-criteria evaluation, our approach achieved significantly better performance on majority of the measures, with the advantages that: (i) it does not require to specify the number of clusters beforehand (it is open ended); (ii) it is online and can find clusters in real time; (iii) it has constant time complexity; (iv) and it is memory efficient as it does not keep the data samples in memory. Overall, it has managed to discover 616 of the total 717 activities. Because it discovers clusters of activities in real time, it is ideal to work alongside an active learning system

    The benthic carbon mineralization on a global scale

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    In this study we present a global distribution pattern and budget of the minimum flux of particulate organic carbon to the sea floor (JPOCα). The estimations are based on regionally specific correlations between the diffusive oxygen flux across the sediment-water interface, the total organic carbon content in surface sediments, and the oxygen concentration in bottom waters. For this, we modified the principal equation of Cai and Reimers [1995] as a basic monod reaction rate, applied within 11 regions where in situ measurements of diffusive oxygen uptake exist. By application of the resulting transfer functions to other regions with similar sedimentary conditions and areal interpolation, we calculated a minimum global budget of particulate organic carbon that actually reaches the sea floor of ∼0.5 GtC yr−1 (>1000 m water depth (wd)), whereas approximately 0.002–0.12 GtC yr−1 is buried in the sediments (0.01–0.4% of surface primary production). Despite the fact that our global budget is in good agreement with previous studies, we found conspicuous differences among the distribution patterns of primary production, calculations based on particle trap collections of the POC flux, and JPOCα of this study. These deviations, especially located at the southeastern and southwestern Atlantic Ocean, the Greenland and Norwegian Sea and the entire equatorial Pacific Ocean, strongly indicate a considerable influence of lateral particle transport on the vertical link between surface waters and underlying sediments. This observation is supported by sediment trap data. Furthermore, local differences in the availability and quality of the organic matter as well as different transport mechanisms through the water column are discussed

    Caracteres agronômicos da mamona influenciados pela época de semeadura.

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