3,031 research outputs found

    The Drosophila Caspase DRONC Cleaves following Glutamate or Aspartate and Is Regulated by DIAP1, HID, and GRIM

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    The caspase family of cysteine proteases plays important roles in bringing about apoptotic cell death. All caspases studied to date cleave substrates COOH-terminal to an aspartate. Here we show that the Drosophila caspase DRONC cleaves COOH-terminal to glutamate as well as aspartate. DRONC autoprocesses itself following a glutamate residue, but processes a second caspase, drICE, following an aspartate. DRONC prefers tetrapeptide substrates in which aliphatic amino acids are present at the P2 position, and the P1 residue can be either aspartate or glutamate. Expression of a dominant negative form of DRONC blocks cell death induced by the Drosophila cell death activators reaper, hid, and grim, and DRONC overexpression in flies promotes cell death. Furthermore, the Drosophila cell death inhibitor DIAP1 inhibits DRONC activity in yeast, and DIAP1's ability to inhibit DRONC-dependent yeast cell death is suppressed by HID and GRIM. These observations suggest that DRONC acts to promote cell death. However, DRONC activity is not suppressed by the caspase inhibitor and cell death suppressor baculovirus p35. We discuss possible models for DRONC function as a cell death inhibitor

    Psychosocial factors underlying physical activity

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    © 2007 Zhang et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Restoration of Sp4 in Forebrain GABAergic Neurons Rescues Hypersensitivity to Ketamine in Sp4 Hypomorphic Mice.

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    BackgroundKetamine produces schizophrenia-like behavioral phenotypes in healthy people. Prolonged ketamine effects and exacerbation of symptoms after the administration of ketamine have been observed in patients with schizophrenia. More recently, ketamine has been used as a potent antidepressant to treat patients with major depression. The genes and neurons that regulate behavioral responses to ketamine, however, remain poorly understood. Sp4 is a transcription factor for which gene expression is restricted to neuronal cells in the brain. Our previous studies demonstrated that Sp4 hypomorphic mice display several behavioral phenotypes relevant to psychiatric disorders, consistent with human SP4 gene associations with schizophrenia, bipolar disorder, and major depression. Among those behavioral phenotypes, hypersensitivity to ketamine-induced hyperlocomotion has been observed in Sp4 hypomorphic mice.MethodsIn the present study, we used the Cre-LoxP system to restore Sp4 gene expression, specifically in either forebrain excitatory or GABAergic inhibitory neurons in Sp4 hypomorphic mice. Mouse behavioral phenotypes related to psychiatric disorders were examined in these distinct rescue mice.ResultsRestoration of Sp4 in forebrain excitatory neurons did not rescue deficient sensorimotor gating nor ketamine-induced hyperlocomotion. Restoration of Sp4 in forebrain GABAergic neurons, however, rescued ketamine-induced hyperlocomotion, but did not rescue deficient sensorimotor gating.ConclusionsOur studies suggest that the Sp4 gene in forebrain GABAergic neurons regulates ketamine-induced hyperlocomotion

    A study of the motion of the three-linked swimmer in viscous fluid using computational and experimental methods

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    Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaves 29-31).An experimental and numerical study was conducted to better understand the mechanics of motion of the three-linked swimmer in viscous fluid. Numerical studies in C++ were used to predict the velocity and motion of the swimmer using a modified analytical model that considers the dynamical and orientational effects of rods at the surface of a fluid. Computational simulations were graphically used to understand the pressure and velocity distributions of the fluid-structure interactions of the three-linked swimmer, with slightly different movement, using an immersed boundary method computer program. Experiments using a mechanical prototype of a three-linked swimmer were conducted to validate and compare the numerical predictions derived from computational studies. Experimental results indicate that a flexible armed swimmer is more than three times as fast as its rigid armed counterpart. The analytical model presented in this study and the corresponding computational numerical simulations were found to capture the trends of the motion, and the predicted horizontal velocity came within 66% in value of the recorded experimental data.by Susan YeYoung Ji.S.B

    Primary Care PhysiciansĘĽ Adherence to Expert Recommendations for Cervical Cancer Screening and Prevention in the Context of Human Papillomavirus Vaccination

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    BACKGROUND: Expert recommendations do not recommend using Papanicolaou (Pap) or human papillomavirus (HPV) test results to determine whether unvaccinated women should receive HPV vaccine, nor do they recommend using vaccine receipt to inform cervical cancer screening practices. This study characterizes physicians' HPV vaccine recommendations and practices in the context of HPV and Pap testing. METHODS: We surveyed family physicians and obstetrician-gynecologists randomly selected from the American Medical Association Masterfile in 2011 (n = 574). Physicians used a 5-point scale (never to always) to report the frequency of (1) using HPV testing results to decide whether to recommend HPV vaccine, and (2) recommending HPV vaccination to women (≤26 years) who had an abnormal Pap test. Physicians also reported (3) intention to change Pap screening frequency for vaccinated women. RESULTS: Across both specialties, 80% correctly reported rarely or never using HPV testing results to guide vaccine recommendations; 66% often or always recommended vaccination to patients with an abnormal Pap result; and 77% did not plan to change Pap screening frequency for vaccinated women. About 41% reported recommendation-consistent practices with all 3 measures. In multivariable analysis, obstetrician-gynecologist specialty and private practice type were associated with higher average overall adherence to recommendations. CONCLUSIONS: Contrary to expert recommendations, a considerable minority of physicians reported recommending HPV vaccination based on HPV and Pap test results. If these clinical practices persist, many young adult women will not realize the benefits of HPV vaccination. Additional efforts are needed to ensure all young women are screened and vaccinated appropriately

    Longitudinal Model Building Using Latent Transition Analysis: An Example Using School Bullying Data

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    Applications of latent transition analysis (LTA) have emerged since the early 1990s, with numerous scientific findings being published in many areas, including social and behavioral sciences, education, and public health. Although LTA is effective as a statistical analytic tool for a person-centered model using longitudinal data, model building in LTA has often been subjective and confusing for applied researchers. To fill this gap in the literature, we review the components of LTA, recommend a framework of fitting LTA, and summarize what acceptable model evaluation tools should be used in practice. The proposed framework of fitting LTA consists of six steps depicted in Figure 1 from step 0 (exploring data) to step 5 (fitting distal variables). We also illustrate the framework of fitting LTA with data on concerns about school bullying from a sample of 1,180 students ranging from 5th to 9th grade (mean age = 12.2 years, SD = 1.29 years at Time 1) over three semesters. We identified four groups of students with distinct patterns of bullying concerns, and found that their concerns about bullying decreased and narrowed to specific concerns about rumors, gossip, and social exclusion over time. The data and command (syntax) files needed for reproducing the results using SAS PROC LCA and PROC LTA (Version 1.3.2) (2015) and Mplus 7.4 (Muthén and Muthén, 1998–2015) are provided as online supplementary materials

    The Efficacy of Conjoint Behavioral Consultation on Parents and Children in the Home Setting: Results of a Randomized Controlled Trial

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    The present study is a large-scale randomized trial testing the effects of a family-school partnership model (i.e., Conjoint Behavioral Consultation, CBC) for promoting behavioral competence and decreasing problem behaviors of children identified by their teachers as disruptive. CBC is a structured approach to problem solving that involves consultants, parents, and teachers. The effects of CBC on family variables that are commonly associated with important outcomes among school-aged children (i.e., family involvement and parent competence in problem solving), as well as child outcomes at home, were evaluated. Participants were 207 children with disruptive behaviors from 91 classrooms in 21 schools in kindergarten through grade 3 and their parents and teachers. Results indicated that there were significantly different increases in home-school communication and parent competence in problem solving for participants in the CBC relative to control group. Likewise, compared to children in the control group, children in the CBC group showed significantly greater decreases in arguing, defiance, noncompliance, and tantrums. The degree of family risk moderated parents’ competence in problem solving and children’s total problem behaviors, teasing, and tantrums

    Multifunctional and robust composite materials comprising gold nanoparticles at a spherical polystyrene particle surface

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    The preparation of composite particles comprising gold nanoparticles (4.5–26 nm) assembled at a polystyrene (PS) surface with tunable loading is reported with wide ranging potentials from cellular studies to catalysis.</p

    Characterization of potential health promoting lipids in the co-products of de-flossed milkweed

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    The floss and oil of the common milkweed (Asclepias syriaca L.) seeds are currently used to produce comforters/pillows and skin care products, respectively. As an outcome of these products, copious quantities co-products (pressed seed meal and pod biomass) are disposed of each year despite the presence of potential health benefiting lipids. The objective of this project was to determine the feasibility of developing the lipid fraction from of these co-products for the fast growing dietary human health market. Although certain types of lipids were affected by the extraction solvent used (hexane and diethyl ether) as were overall amounts, analysis of the each extract showed novel lipid profiles with several potential health benefiting agents present at levels comparable to or exceeding those present in other typically consumed dietary oils or food systems (vitamin E, carotenoids, sterols and unsaturated free fatty acids, particularly the both omega 7-fatty acids)
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