844 research outputs found

    Islands Containing Slowly Hydrolyzable GTP Analogs Promote Microtubule Rescues

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    Microtubules are dynamic polymers of GTP- and GDP-tubulin that undergo stochastic transitions between growing and shrinking phases. Rescues, the conversion from shrinking to growing, have recently been proposed to be to the result of regrowth at GTP-tubulin islands within the lattice of growing microtubules. By introducing mixed GTP/GDP/GMPCPP (GXP) regions within the lattice of dynamic microtubules, we reconstituted GXP islands in vitro (GMPCPP is the slowly hydrolyzable GTP analog guanosine-5′-[(α,β)-methyleno]triphosphate). We found that such islands could reproducibly induce rescues and that the probability of rescue correlated with both the size of the island and the percentage of GMPCPP-tubulin within the island. The islands slowed the depolymerization rate of shortening microtubules and promoted regrowth more readily than GMPCPP seeds. Together, these findings provide new mechanistic insights supporting the possibility that rescues could be triggered by enriched GTP-tubulin regions and present a new tool for studying such rescue events in vitro

    Translating a health behavior change intervention for delivery to 2-year college students: the importance of formative research

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    Young adults are at risk for weight gain in the transition to independent adulthood; 2-year college students are at greater risk and understudied relative to 4-year students. This project conducted formative research for a randomized controlled weight gain prevention trial among 2-year college students, to ensure appropriateness of content and delivery of a curriculum originally developed for 4-year college students. Data were collected from community college students, faculty, and staff from October 2009 to August 2011. Work included focus groups and key informant interviews, curriculum pilot testing, and social network and support website beta testing. Based on focus groups and interviews, program content, course delivery modes, and communication channels were adjusted to meet population interests and preferences. The course was delivered successfully in pilot testing, and the website was received well by beta testers. Formative work successfully guided program adaptations to address population needs

    Weight and Weight-Related Behaviors Among 2-Year College Students

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    The purpose of this paper is to describe weight indicators and weight-related behaviors of students enrolled in 2-year colleges, including sex differences

    Model Convolution: A Computational Approach to Digital Image Interpretation

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    Digital fluorescence microscopy is commonly used to track individual proteins and their dynamics in living cells. However, extracting molecule-specific information from fluorescence images is often limited by the noise and blur intrinsic to the cell and the imaging system. Here we discuss a method called “model-convolution,” which uses experimentally measured noise and blur to simulate the process of imaging fluorescent proteins whose spatial distribution cannot be resolved. We then compare model-convolution to the more standard approach of experimental deconvolution. In some circumstances, standard experimental deconvolution approaches fail to yield the correct underlying fluorophore distribution. In these situations, model-convolution removes the uncertainty associated with deconvolution and therefore allows direct statistical comparison of experimental and theoretical data. Thus, if there are structural constraints on molecular organization, the model-convolution method better utilizes information gathered via fluorescence microscopy, and naturally integrates experiment and theory

    Cone photoreceptor structure in patients with x-linked cone dysfunction and red-green color vision deficiency

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    PURPOSE: Mutations in the coding sequence of the L and M opsin genes are often associated with X-linked cone dysfunction (such as Bornholm Eye Disease, BED), though the exact color vision phenotype associated with these disorders is variable. We examined individuals with L/M opsin gene mutations to clarify the link between color vision deficiency and cone dysfunction. METHODS: We recruited 17 males for imaging. The thickness and integrity of the photoreceptor layers were evaluated using spectral-domain optical coherence tomography. Cone density was measured using high-resolution images of the cone mosaic obtained with adaptive optics scanning light ophthalmoscopy. The L/M opsin gene array was characterized in 16 subjects, including at least one subject from each family. RESULTS: There were six subjects with the LVAVA haplotype encoded by exon 3, seven with LIAVA, two with the Cys203Arg mutation encoded by exon 4, and two with a novel insertion in exon 2. Foveal cone structure and retinal thickness was disrupted to a variable degree, even among related individuals with the same L/M array. CONCLUSIONS: Our findings provide a direct link between disruption of the cone mosaic and L/M opsin variants. We hypothesize that, in addition to large phenotypic differences between different L/M opsin variants, the ratio of expression of first versus downstream genes in the L/M array contributes to phenotypic diversity. While the L/M opsin mutations underlie the cone dysfunction in all of the subjects tested, the color vision defect can be caused either by the same mutation or a gene rearrangement at the same locus

    Racial Differences in the Association Between Luminal Master Regulator Gene Expression Levels and Breast Cancer Survival

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    Compared with their European American (EA) counterparts, African American (AA) women are more likely to die from breast cancer in the United States. This disparity is greatest in hormone receptor-positive subtypes. Here we uncover biological factors underlying this disparity by comparing functional expression and prognostic significance of master transcriptional regulators of luminal differentiation.Fil: Byun, Jung S.. National Institutes of Health; Estados UnidosFil: Singhal, Sandeep K.. Columbia University; Estados UnidosFil: Park, Samson. National Institutes of Health; Estados UnidosFil: Yi, Dae Ik. National Institutes of Health; Estados UnidosFil: Yan, Tingfen. National Institutes of Health; Estados UnidosFil: Caban, Ambar. Columbia University Medical Center; Estados UnidosFil: Jones, Alana. National Institutes of Health; Estados UnidosFil: Mukhopadhyay, Partha. Columbia University Medical Center; Estados UnidosFil: Gille, Sarah. National Institutes of Health; Estados UnidosFil: Hewitt, Stephen M.. No especifíca;Fil: Newman, Lisa. No especifíca;Fil: Davis, Melissa B.. Henry Ford Health System; Estados UnidosFil: Jenkins, Brittany D.. Henry Ford Health System; Estados UnidosFil: Sepulveda, Jorge L.. Columbia University Medical Center; Estados UnidosFil: de Siervi, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Nápoles, Anna María. National Institute On Minority Health And Health Disparities; Estados UnidosFil: Vohra, Nasreen A.. East Carolina University; Estados UnidosFil: Gardner, Kevin. Columbia University Medical Center; Estados Unido

    Reduction of missed appointments at an urban primary care clinic: a randomised controlled study

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    <p>Abstract</p> <p>Background</p> <p>Missed appointments are known to interfere with appropriate care and to misspend medical and administrative resources. The aim of this study was to test the effectiveness of a sequential intervention reminding patients of their upcoming appointment and to identify the profile of patients missing their appointments.</p> <p>Methods</p> <p>We conducted a randomised controlled study in an urban primary care clinic at the Geneva University Hospitals serving a majority of vulnerable patients. All patients booked in a primary care or HIV clinic at the Geneva University Hospitals were sent a reminder 48 hrs prior to their appointment according to the following sequential intervention: 1. Phone call (fixed or mobile) reminder; 2. If no phone response: a Short Message Service (SMS) reminder; 3. If no available mobile phone number: a postal reminder. The rate of missed appointment, the cost of the intervention, and the profile of patients missing their appointment were recorded.</p> <p>Results</p> <p>2123 patients were included: 1052 in the intervention group, 1071 in the control group. Only 61.7% patients had a mobile phone recorded at the clinic. The sequential intervention significantly reduced the rate of missed appointments: 11.4% (n = 122) in the control group and 7.8% (n = 82) in the intervention group (p < 0.005), and allowed to reallocate 28% of cancelled appointments. It also proved to be cost effective in providing a total net benefit of 1846. - EUR/3 months. A satisfaction survey conducted with 241 patients showed that 93% of them were not bothered by the reminders and 78% considered them to be useful. By multivariate analysis, the following characteristics were significant predictors of missed appointments: younger age (OR per additional decade 0.82; CI 0.71-0.94), male gender (OR 1.72; CI 1.18-2.50), follow-up appointment >1year (OR 2.2; CI: 1.15-4.2), substance abuse (2.09, CI 1.21-3.61), and being an asylum seeker (OR 2.73: CI 1.22-6.09).</p> <p>Conclusion</p> <p>A practical reminder system can significantly increase patient attendance at medical outpatient clinics. An intervention focused on specific patient characteristics could further increase the effectiveness of appointment reminders.</p

    Being user-oriented: convergences, divergences, and the potentials for systematic dialogue between disciplines and between researchers, designers, and providers

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    The challenge this panel addresses is drawn from intersecting literature reviews and critical commentaries focusing on: 1) user studies in multiple fields; and 2) the difficulties of bringing different disciplines and perspectives to bear on user‐oriented research, design, and practice. 1 The challenge is that while we have made some progress in collaborative work, we have some distance to go to become user‐oriented in inter‐disciplinary and inter‐perspective ways. The varieties of our approaches and solutions are, as some observers suggest, an increasing cacophony. One major difficulty is that most discussions are solution‐oriented, offering arguments of this sort ‐‐ if only we addressed users in this way… Each solution becomes yet another addition to the cacophony. This panel implements a central approach documented for its utility by communication researchers and long used by communication mediators and negotiators ‐‐ that of focusing not on communication but rather on meta‐communication: communicating about communication. The intent in the context of this panel is to help us refocus attention from too frequent polarizations between alternative solutions to the possibility of coming to understand what is behind the alternatives and where they point to experientially‐based convergences and divergences, both of which might potentially contribute to synergies. The background project for this panel comes from a series of in‐depth interviews with expert researchers, designers, and providers in three field groupings ‐‐ library and information science; human computer interaction/information technology; and communication and media studies. One set of interviews involved 5‐hour focus groups with directors of academic and public libraries serving 44 colleges and universities in central Ohio; the second involved one‐on‐one interviews averaging 50 minutes with 81 nationally‐internationally known experts in the 3 fields, 25‐27 interviews per field. Using Dervin\u27s Sense‐Making Methodological approach to interviewing, the expert interviews of both kinds asked each interviewee: what he/she considered to be the big unanswered questions about users and what explained why the questions have not been answered; and, what he/she saw as hindering versus helping in attempts to communicate about users across disciplinary and perspective gaps. 2 The panel consists of six teams, two from each field. Prior to the panel presentation at ASIST, each team will have read the set of interviews and completed impressionistic essays of what patterns and themes they saw as emerging. At this stage, team members will purposively not homogenize their differences and most will write solo‐authored essays that will be placed on a web‐site accessible to ASIST members prior to the November meeting. In addition, at least one systematic analysis will be completed and available online. 3 At the ASIST panel, each team\u27s leader will present a brief and intentionally provocative impressionist account of what his/her team came to understand about our struggles communicating across fields and perspectives about users. Again, each team will purposively not homogenize its own differences in viewpoints, but rather highlight them as fodder for discussion. A major purpose will be to invite audience members to join the panel in discussion. At least 20 minutes will be left open for this purpose

    Pan-Cancer Analysis of lncRNA Regulation Supports Their Targeting of Cancer Genes in Each Tumor Context

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    Long noncoding RNAs (lncRNAs) are commonly dys-regulated in tumors, but only a handful are known toplay pathophysiological roles in cancer. We inferredlncRNAs that dysregulate cancer pathways, onco-genes, and tumor suppressors (cancer genes) bymodeling their effects on the activity of transcriptionfactors, RNA-binding proteins, and microRNAs in5,185 TCGA tumors and 1,019 ENCODE assays.Our predictions included hundreds of candidateonco- and tumor-suppressor lncRNAs (cancerlncRNAs) whose somatic alterations account for thedysregulation of dozens of cancer genes and path-ways in each of 14 tumor contexts. To demonstrateproof of concept, we showed that perturbations tar-geting OIP5-AS1 (an inferred tumor suppressor) andTUG1 and WT1-AS (inferred onco-lncRNAs) dysre-gulated cancer genes and altered proliferation ofbreast and gynecologic cancer cells. Our analysis in-dicates that, although most lncRNAs are dysregu-lated in a tumor-specific manner, some, includingOIP5-AS1, TUG1, NEAT1, MEG3, and TSIX, synergis-tically dysregulate cancer pathways in multiple tumorcontexts
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