2,858 research outputs found

    Human embryos from overweight and obese women display phenotypic and metabolic abnormalities

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    STUDY QUESTION Is the developmental timing and metabolic regulation disrupted in embryos from overweight or obese women? SUMMARY ANSWER Oocytes from overweight or obese women are smaller than those from women of healthy weight, yet post-fertilization they reach the morula stage faster and, as blastocysts, show reduced glucose consumption and elevated endogenous triglyceride levels. WHAT IS KNOWN ALREADY Female overweight and obesity is associated with infertility. Moreover, being overweight or obese around conception may have significant consequences for the unborn child, since there are widely acknowledged links between events occurring during early development and the incidence of a number of adult disorders. STUDY DESIGN, SIZE, DURATION We have performed a retrospective, observational analysis of oocyte size and the subsequent developmental kinetics of 218 oocytes from 29 consecutive women attending for ICSI treatment and have related time to reach key developmental stages to maternal bodyweight. In addition, we have measured non-invasively the metabolic activity of 150 IVF/ICSI embryos from a further 29 consecutive women who donated their surplus embryos to research, and have related the data retrospectively to their body mass index (BMI). PARTICIPANTS/MATERIALS, SETTING, METHODS In a clinical IVF setting, we compared oocyte morphology and developmental kinetics of supernumerary embryos collected from overweight and obese women, with a BMI in excess of 25 kg/m2 to those from women of healthy weight. A Primovision Time-Lapse system was used to measure developmental kinetics and the non-invasive COnsumption/RElese of glucose, pyruvate, amino acids and lactate were measured on spent droplets of culture medium. Total triglyceride levels within individual embryos were also determined. MAIN RESULTS AND THE ROLE OF CHANCE Human oocytes from women presenting for fertility treatment with a BMI exceeding 25 kg/m2 are smaller (R2 = −0.45; P = 0.001) and therefore less likely to complete development post-fertilization (P < 0.001). Those embryos that do develop reach the morula stage faster than embryos from women of a BMI < 25 kg/m2

    Unequal relationships in high and low power distance societies: a comparative study of tutor - student role relations in Britain and China

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    This study investigated people's conceptions of an unequal role relationship in two different types of society: a high power distance society and a low power distance society. The study focuses on the role relationship of tutor and student. British and Chinese tutors and postgraduate students completed a questionnaire that probed their conceptions of degrees of power differential and social distance/closeness in this role relationship. ANOVA results yielded a significant nationality effect for both aspects. Chinese respondents judged the relationship to be closer and to have a greater power differential than did British respondents. Written comments on the questionnaire and interviews with 9 Chinese academics who had experienced both British and Chinese academic environments supported the statistical findings and indicated that there are fundamental ideological differences associated with the differing conceptions. The results are discussed in relation to Western and Asian concepts of leadership and differing perspectives on the compatibility/incompatibility of power and distance/closeness

    A Molecular Platinum Cluster Junction: A Single-Molecule Switch

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    We present a theoretical study of the electronic transport through single-molecule junctions incorporating a Pt6 metal cluster bound within an organic framework. We show that the insertion of this molecule between a pair of electrodes leads to a fully atomically engineered nano-metallic device with high conductance at the Fermi level and two sequential high on/off switching states. The origin of this property can be traced back to the existence of a HOMO which consists of two degenerate and asymmetric orbitals, lying close in energy to the Fermi level of the metallic leads. Their degeneracy is broken when the molecule is contacted to the leads, giving rise to two resonances which become pinned close to the Fermi level and display destructive interference.Comment: 4 pages, 4 figures. Reprinted (adapted) with permission from J. Am. Chem. Soc., 2013, 135 (6), 2052. Copyright 2013 American Chemical Societ

    Cervical Cancer

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    This chapter in Cancer Concepts: A Guidebook for the Non-Oncologist presents provides an overview of cervical cancer. The etiology, pathology, staging, and principles of treatment will be reviewed.https://escholarship.umassmed.edu/cancer_concepts/1014/thumbnail.jp

    High-Frequency InAIAs/InGaAs Metal-Insulator-Doped Semiconductor Field-Effect Transistors (MIDFETs) for Telecommunications

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    Contains an introduction, reports on two research projects and a list of publications and conference papers.Charles S. Draper Laboratory Contract DL-H-418488Joint Services Electronics Program Contract DAAL03-89-C-000

    Unbiased Global Optimization of Lennard-Jones Clusters for N <= 201 by Conformational Space Annealing Method

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    We apply the conformational space annealing (CSA) method to the Lennard-Jones clusters and find all known lowest energy configurations up to 201 atoms, without using extra information of the problem such as the structures of the known global energy minima. In addition, the robustness of the algorithm with respect to the randomness of initial conditions of the problem is demonstrated by ten successful independent runs up to 183 atoms. Our results indicate that the CSA method is a general and yet efficient global optimization algorithm applicable to many systems.Comment: revtex, 4 pages, 2 figures. Physical Review Letters, in pres

    Thermodynamics of C incorporation on Si(100) from ab initio calculations

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    We study the thermodynamics of C incorporation on Si(100), a system where strain and chemical effects are both important. Our analysis is based on first-principles atomistic calculations to obtain the important lowest energy structures, and a classical effective Hamiltonian which is employed to represent the long-range strain effects and incorporate the thermodynamic aspects. We determine the equilibrium phase diagram in temperature and C chemical potential, which allows us to predict the mesoscopic structure of the system that should be observed under experimentally relevant conditions.Comment: 5 pages, 3 figure

    Construction, gene delivery, and expression of DNA tethered nanoparticles

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    PURPOSE: Layered nanoparticles have the potential to deliver any number of substances to cells both in vitro and in vivo. The purpose of this study was to develop and test a relatively simple alternative to custom synthesized nanoparticles for use in multiple biological systems, with special focus on the eye. METHODS: The biotin-labeled transcriptionally active PCR products (TAP) were conjugated to gold, semiconductor nanocrystals, and magnetic nanoparticles (MNP) coated with streptavidin. The process of nanoparticle construction was monitored with gel electrophoresis. Fluorescence microscopy followed by image analysis was used to examine gene expression levels from DNA alone and tethered MNP in human hepatoma derived Huh-7 cells. Adult retinal endothelial cells from both dog (ADREC) and human (HREC) sources were transfected with nanoparticles and reporter gene expression evaluated with confocal and fluorescent microscopy. Transmission electron microscopy was used to quantify the concentration of nanoparticles in a stock solution. Nanoparticles were evaluated for transfection efficiency, determined by fluorescence microscopy cell counts. Cells treated with MNP were evaluated for increased reactive oxygen species (ROS) and necrosis with flow cytometry. RESULTS: Both 5' and 3' biotin-labeled TAP bound equally to MNP and there were no differences in functionality between the two tethering orientations. Free DNA was easily removed by the use of magnetic columns. These particles were also able to deliver genes to a human hepatoma cell line, Huh-7, but transfection efficiency was greater than TAP. The semiconductor nanocrystals and MNP had the highest transfection efficiencies. The MNP did not induce ROS formation or necrosis after 48 h of incubation. CONCLUSIONS: Once transfected, the MNP had reporter gene expression levels equivalent to TAP. The nanoparticles, however, had better transfection efficiencies than TAP. The magnetic nanoparticles were the most easily purified of all the nanoparticles tested. This strategy for bioconjugating TAP to nanoparticles is valuable because nanoparticle composition can be changed and the system optimized quickly. Since endothelial cells take up MNP, this strategy could be used to target neovascularization as occurs in proliferative retinopathies. Multiple cell types were used to test this technology and in each the nanoparticles were capable of transfection. In adult endothelial cells the MNP appeared innocuous, even at the highest doses tested with respect to ROS and necrosis. This technology has the potential to be used as more than just a vector for gene transfer, because each layer has the potential to perform its own unique function and then degrade to expose the next functional layer

    State authenticity

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    State authenticity is the sense that one is currently in alignment with one’s true or real self. We discuss state authenticity as seen by independent raters, describe its phenomenology, outline its triggers, consider its well-being and behavioral implications, and sketch out a cross-disciplinary research agenda

    The Interpersonal Style and Complementarity Between Crisis Negotiators and Forensic Inpatients

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    Previous negotiation research has explored the interaction and communication between crisis negotiators and perpetrators. A crisis negotiator attempts to resolve a critical incident through negotiation with an individual, or group of persons in crisis. The purpose of this study was to establish the interpersonal style of crisis negotiators and complementarity of the interpersonal interaction between them and forensic inpatients. Crisis negotiators, clinical workers and students (n = 90) used the Check List of Interpersonal Transactions-Revised (CLOIT-R) to identify interpersonal style, along with eight vignettes detailing interpersonal styles. Crisis negotiators were most likely to have a friendly interpersonal style compared to the other non-trained groups. Complementarity theory was not exclusively supported as submissive individuals did not show optimistic judgments in working with dominant forensic inpatients and vice versa. Exploratory analysis revealed that dominant crisis negotiators were optimistic in working with forensic inpatients with a dominant interpersonal style. This study provides insight into the area of interpersonal complementarity of crisis negotiators and forensic inpatients. Whilst further research is required, a potential new finding was established, with significant ‘similarity’ found when dominant crisis negotiators are asked to work with dominant forensic inpatients
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