528 research outputs found
Divergence of Vertebrate and Insect Specific Toxin Genes between Three Species of Widow Spider
The Brown widow spider, Latrodectus geometricus, is an introduced species to the southern United States (Brown 2008). The Brown widow is a member of the widow spider genus Latrodectus which includes the southern Black widow (L. mactans) and 29 other venomous species. All species of widow spiders produce venom which is used against both predator and prey. These venoms are composed of several different species-specific toxins, each encoded by a different gene (Graudins 2012). Previous research has shown that positive selection pressures affect the venom of snakes and snails, thus aiding in adaptive potential of the species (Gibbs 2008; Duda 1999). The study presented here was designed to sequence and characterize the α-latroinsectotoxin gene for the Brown and southern Black widow spiders. The sequence data was used to address two objectives: 1) quantify the nucleotide and amino acid divergence in the a-latroinsectotoxin gene between the Brown widow, southern Black widow, and Mediterranean Black widow spiders; and 2) compare levels of divergence to that of α-latrotoxin and a non-toxin gene Cytochrome Oxidase I. Results showed that nucleotide difference lead to large amino acid differences between species in the toxin genes. Nucleotide divergence between species was similar at all three genes while amino acid divergence was 2.3 to 3.2 times higher in the toxin genes relative to the non-toxin gene (COI). High amino acid variation in the toxin genes between species suggests a structural basis exists for potential differences in functionality and toxicity
Finger extensor variability in TMS parameters among chronic stroke patients
BACKGROUND: This study determined the reliability of topographic motor cortical maps and MEP characteristics in the extensor digitorum communis (EDC) evoked by single-pulse TMS among patients with chronic stroke. METHODS: Each of ten patients was studied on three occasions. Measures included location of the EDC hotspot and center of gravity (COG), threshold of activation and average amplitude of the hotspot, number of active sites, map volume, and recruitment curve (RC) slope. RESULTS: Consistent intrahemispheric measurements were obtained for the three TMS mapping sessions for all measured variables. No statistically significant difference was observed between hemispheres for the number of active sites, COG distance or the RC slope. The magnitude and range of COG movement between sessions were similar to those reported previously with this muscle in able-bodied individuals. The average COG movement over three sessions in both hemispheres was 0.90 cm. The average COG movement in the affected hemisphere was 1.13 (± 0.08) cm, and 0.68 (± 0.04) cm) for the less affected hemisphere. However, significant interhemispheric variability was seen for the average MEP amplitude, normalized map volume, and resting motor threshold. CONCLUSION: The physiologic variability in some TMS measurements of EDC suggest that interpretation of TMS mapping data derived from hemiparetic patients in the chronic stage following stroke should be undertaken cautiously. Irrespective of the muscle, potential causes of variability should be resolved to accurately assess the impact of pharmacological or physical interventions on cortical organization as measured by TMS among patients with stroke
Introduction to a Special Issue on the Impact of Immigrant Legalization Initiatives: International Perspectives on Immigration and the World of Work
This article is the third in a series to celebrate the 70th anniversary of the ILR Review. The series features articles that analyze the state of research and future directions for important themes the journal has featured over its many years of publication. In this issue, we also feature a special cluster of articles and book reviews on one of the most critical labor market issues across the globe—the legalization and integration of immigrants into national labor markets.
Despite the urgent need for immigration reform in the United States, there is a paucity of US research that looks at the impact of a shift from unauthorized to legal immigrant status in the workplace. The US immigration literature has also paid little attention to immigrant legalization policies outside of the United States, despite the fact that other countries have implemented such policies with far more regularity. The articles in this special issue draw on studies of legalization initiatives in major immigrant destinations: Canada, Italy, and the United Kingdom. Together they underscore the importance of cross-national perspectives for understanding the range of legalization programs and their impact on immigrant workers, the workplace, and the labor market. These findings contribute to key questions in migration scholarship and inform the global policy debate surrounding the integration and well-being of immigrant
The Diffusion of Innovation in a Math Professional Learning Community
AbstractIn a southern U.S. suburban middle school, officials required the implementation of professional learning communities (PLCs) to improve student achievement in math. Despite PLC implementation, math student achievement did not improve over 4 years since implementation in the fall of 2014. The problem was that middle school math teachers and educational personnel struggled to implement the innovation of a PLC at the target school. The purpose of this exploratory case study was to examine teachers’ and school officials’ perceptions of the math PLC process using Rogers’s diffusion of innovation (DOI) framework and archival documents to determine reasons for the challenges with PLC implementation. The research questions focused on PLC teachers’ and school officials’ perceptions of the relative advantage, compatibility, complexity, trialability, and observability of the math PLC as well as analysis of archived documents. Using exploratory case study design, data were collected through semistructured interviews with eight educators who met the criteria of being a current or previous math teacher or school official involved in PLC training and implementation. Inductive and thematic analysis yielded emergent themes: (a) relative advantage of the PLC as an innovation, (b) compatibility, (c) cohesive understanding, (d) time and complexity, (e) positive effects of trialability, (f) influence on instructional practices, and (g) collaboration. Findings indicated educators would benefit from a deeper understanding of PLC implementation using the DOI framework. The 3-day professional development project may strengthen the implementation of PLCs and may promote social change by serving as a model to other districts working to increase student achievement and informing leaders of any organization of the importance of considering DOI perceptions
Variation in Long-Term Acute Care Hospital Use After Intensive Care
Long-term acute care hospitals (LTACs) are an increasingly common discharge destination for patients recovering from intensive care. In this article the authors use U.S. Medicare claims data to examine regional- and hospital-level variation in LTAC utilization after intensive care to determine factors associated with their use. Using hierarchical regression models to control for patient characteristics, this study found wide variation in LTAC utilization across hospitals, even controlling for LTAC access within a region. Several hospital characteristics were independently associated with increasing LTAC utilization, including increasing hospital size, for-profit ownership, academic teaching status, and colocation of the LTAC within an acute care hospital. These findings highlight the need for research into LTAC admission criteria and the incentives driving variation in LTAC utilization across hospitals
Usability Testing of an Electronic Patient-Reported Outcome System for Survivors of Critical Illness
BACKGROUND: Web-based electronic patient-reported outcomes (ePRO) measures are increasingly used to facilitate patient-centered health assessments. However, it is unknown if ePRO completion is feasible for recently ill intensive care unit (ICU) survivors and their families.
OBJECTIVE: To develop and evaluate the usability of a novel ePRO system (ePRO to Support People and Enhance Recovery [ePROSPER]) among ICU survivors and their families within an ongoing clinical trial.
METHODS: Paper-based PROs were iteratively adapted to electronic forms (ePROs). Then, the usability of ePROSPER was assessed among 60 patients, their family members, and PRO and programming experts via questionnaires (eg, Systems Usability Scale), "think aloud" open-ended feedback, task completion times, and error rates.
RESULTS: Input from patients and their families was used to incorporate user-experience modifications into ePROSPER. This feedback also led to inclusion of automated reminders for questionnaire completion and real-time alerts for staff triggered by high symptom levels. Median usability scores increased over testing cycles from 40 to 73 to 95, nearing the maximum score and showing excellent usability. All users completed ePROSPER within 20 minutes; 87% preferred it to a written version. ePROSPER was then implemented in a clinical trial without data errors.
CONCLUSIONS: Automated ePRO systems can be successfully integrated in a post-ICU clinical trial setting. The value of integrating such systems in direct clinical care should be assessed in future studies
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