930 research outputs found

    Endogenous testosterone is associated with lower amygdala reactivity to angry faces and reduced aggressive behavior in healthy young women

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    Testosterone and cortisol have been proposed to influence aggressive behavior by altering the neural processing of facial threat signals. However, this has not been investigated in direct social interactions. Here, we explored the joint impact of testosterone, cortisol, and brain reactivity to anger expressions on women's reactive aggression in the Social Threat Aggression Paradigm (STAP). The STAP is a competitive reaction time task in which the purported opponent displays either an angry or a neutral facial expression at the beginning of each trial and delivers increasingly loud sound blasts to the participants, successfully provoking them. Strikingly, salivary testosterone at scan-time was negatively related to both aggression and basolateral amygdala (BLA) reactivity to angry faces, whereas cortisol had no effect. When the opponent looked angry, BLA-orbitofrontal coupling was reduced, and BLA reactivity was positively related to aggression. The latter relationship was fully mediated by bilateral superior temporal gyrus (STG) activation. Our results thus support previous neurobiological models of aggression, and extend them by demonstrating that fast amygdala responses to threat modulate STG activity in order to favor aggressive retaliation. Furthermore, our study agrees with recent evidence underscoring a fear-reducing and strategically prosocial effect of testosterone on human social behavior

    Static and mobile DXA scanner in-vivo cross-calibration study

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    Copyright © 2012 The College of Radiographers. Published by Elsevier Ltd. NOTICE: this is the author’s version of a work that was accepted for publication in Radiography. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Radiography Vol. 19 (2013), DOI: 10.1016/j.radi.2012.08.005In-vitro cross-calibration of DXA scanning equipment, with a phantom device, has been recommended for assessing agreement between devices co-located within DXA scanning services. This study evaluated in-vivo and in-vitro cross-calibration of a static and a mobile DXA scanner within the same service in their individual clinical settings. 50 individuals from a volunteer group were recruited to take part in this study and had DXA measurements made on two GE Lunar Prodigy Advance (GE Lunar, Bedford, UK) scanners. Results in this study showed that the scanners agreed, with no clinically significant differences in BMD measurements made at the same site on the individual devices used in this study. The in-vivo cross-calibration of the instruments was a useful experience, which demonstrated closely calibrated systems and raised the profile of the bone densitometry service within the hospital

    Enhanced Biostability and Cellular Uptake of Zinc Oxide Nanocrystals Shielded with Phospholipid Bilayer

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    The widespread use of ZnO nanomaterials for biomedical applications, including therapeutic drug delivery or stimuli-responsive activation, as well as imaging, imposes a careful control over the colloidal stability and long-term behaviour of ZnO in biological media. Moreover, the effect of ZnO nanostructures on living cells, in particular cancer cells, is still under debate. This paper discusses the role of surface chemistry and charge of zinc oxide nanocrystals, of around 15 nm in size, which influence their behaviour in biological fluids and effect on cancer cells. In particular, we address this problem by modifying the surface of pristine ZnO nanocrystals (NCs), rich of hydroxyl groups, with positively charged amino-propyl chains or, more innovatively, by self-assembling a double-lipidic membrane, shielding the ZnO NCs. Our findings show that the prolonged immersion in simulated human plasma and in the cell culture medium leads to highly colloidally dispersed ZnO NCs only when coated by the lipidic bilayer. In contrast, the pristine and amine-functionalized NCs form huge aggregates after already one hour of immersion. Partial dissolution of these two samples into potentially cytotoxic Zn2+ cations takes place, together with the precipitation of phosphate and carbonate salts on the NCs’ surface. When exposed to living HeLa cancer cells, higher amounts of lipid-shielded ZnO NCs are internalized with respect to the other samples, thus showing a reduced cytotoxicity, based on the same amount of internalized NCs. These results pave the way for the development of novel theranostic platforms based on ZnO NCs. The new formulation of ZnO shielded with a lipid-bilayer will prevent strong aggregation and premature degradation into toxic by-products, and promote a highly efficient cell uptake for further therapeutic or diagnostic functions

    Psychophysiology-based QoE assessment : a survey

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    We present a survey of psychophysiology-based assessment for quality of experience (QoE) in advanced multimedia technologies. We provide a classification of methods relevant to QoE and describe related psychological processes, experimental design considerations, and signal analysis techniques. We summarize multimodal techniques and discuss several important aspects of psychophysiology-based QoE assessment, including the synergies with psychophysical assessment and the need for standardized experimental design. This survey is not considered to be exhaustive but serves as a guideline for those interested to further explore this emerging field of research

    Dynamic nuclear polarization at high magnetic fields in liquids

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    High field dynamic nuclear polarization spectrometer for liquid samples have been constructed. â–º The field dependence of the Overhauser DNP efficiency has been measured for the first time up to 9.2 T. â–º High DNP enhancements for liquid samples have been observed at high magnetic fields. â–º The enhancements have been compared with results from NMRD, MD and theoretical models. â–º Coherent and relaxation effects within fast magnetic field changes have been analyzed

    Ovarian Cyst Fluid of Serous Ovarian Tumors Contains Large Quantities of the Brain Amino Acid N-acetylaspartate

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    BACKGROUND: In humans, N-acetyl L-aspartate (NAA) has not been detected in other tissues than the brain. The physiological function of NAA is yet undefined. Recently, it has been suggested that NAA may function as a molecular water pump, responsible for the removal of large amounts of water from the human brain. Ovarian tumors typically present as large cystic masses with considerable fluid accumulation. METHODOLOGY AND PRINCIPAL FINDINGS: Using Gas Chromatography-Mass Spectrometry, we demonstrated that NAA was present in a high micromolar concentration in oCF of epithelial ovarian tumors (EOTs) of serous histology, sometimes in the same range as found in the extracellular space of the human brain. In contrast, oCF of EOTs with a mucinous, endometrioid and clear cell histological subtype contained a low micromolar concentration of NAA. Serous EOTs have a cellular differentiation pattern which resembles the lining of the fallopian tube and differs from the other histological subtypes. The NAA concentration in two samples of fluid accumulation in the fallopian tube (hydrosalpinx) was in the same ranges as NAA found in oCF of serous EOTs. The NAA concentration in oCF of patients with serous EOTs was mostly 10 to 50 fold higher than their normal serum NAA concentration, whereas in patients with other EOT subtypes, serum and cyst fluid NAA concentration was comparable. CONCLUSIONS AND SIGNIFICANCE: The high concentration of NAA in cyst fluid of serous EOTs and low serum concentrations of NAA in these patients, suggest a local production of NAA in serous EOTs. Our findings provide the first identification of NAA concentrations high enough to suggest local production outside the human brain. Our findings contribute to the ongoing research understanding the physiological function of NAA in the human body

    GALEX selected Lyman Break Galaxies at z~2: Comparison with other Populations

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    We present results of a search for bright Lyman break galaxies at 1.5<=z<=2.5 in the GOODS-S field using a NUV-dropout technique in combination with color-selection. We derived a sample of 73 LBG candidates. We compare our selection efficiencies to BM/BX- and BzK methods (techniques solely based on ground-based data sets), and find the NUV data to provide greater efficiency for selecting star-forming galaxies. We estimate LBG candidate ages, masses, star formation rates, and extinction from fitting PEGASE synthesis evolution models. We find about 20% of our LBG candidates are comparable to infrared luminous LBGs or sub-millimeter galaxies which are thought to be precursors of massive elliptical galaxies today. Overall, we can show that although BM/BX and BzK methods do identify star-forming galaxies at z~2, the sample they provide biases against those star-forming galaxies which are more massive and contain sizeable red stellar populations. A true Lyman break criterion at z~2 is therefore more directly comparable to the populations found at z~3, which does contain a red fraction.Comment: 14 pages, 11 figures, accepted for publication in Ap

    A common framework for the evaluation of psychophysiological visual quality assessment

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    The assessment of perceived quality based on psychophysiological methods recently gained attraction as it potentiallyovercomes certain flaws of psychophysical approaches. Although studies report promising results, it is not possible toarrive at decisive and comparable conclusions that recommend the use of one or another method for a specific applicationor research question. The video quality expert group started a project on psychophysiological quality assessment to studythese novel approaches and to develop a test plan that enables more systematic research. This test plan comprises of a specificallydesigned set of quality annotated video sequences, suggestions for psychophysiological methods to be studied inquality assessment, and recommendations for the documentation and publications of test results. The test plan is presentedin this article.Celtc-Next 5G Perfecta (2018-00735

    Human PrimPol is a highly error-prone polymerase regulated by single-stranded DNA binding proteins

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    PrimPol is a recently identified polymerase involved in eukaryotic DNA damage tolerance, employed in both re-priming and translesion synthesis mechanisms to bypass nuclear and mitochondrial DNA lesions. In this report, we investigate how the enzymatic activities of human PrimPol are regulated. We show that, unlike other TLS polymerases, PrimPol is not stimulated by PCNA and does not interact with it in vivo. We identify that PrimPol interacts with both of the major single-strand binding proteins, RPA and mtSSB in vivo. Using NMR spectroscopy, we characterize the domains responsible for the PrimPol-RPA interaction, revealing that PrimPol binds directly to the N-terminal domain of RPA70. In contrast to the established role of SSBs in stimulating replicative polymerases, we find that SSBs significantly limit the primase and polymerase activities of PrimPol. To identify the requirement for this regulation, we employed two forward mutation assays to characterize PrimPol's replication fidelity. We find that PrimPol is a mutagenic polymerase, with a unique error specificity that is highly biased towards insertion-deletion errors. Given the error-prone disposition of PrimPol, we propose a mechanism whereby SSBs greatly restrict the contribution of this enzyme to DNA replication at stalled forks, thus reducing the mutagenic potential of PrimPol during genome replication

    Sheep Updates 2005 - Part 3

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    This session covers seven papers from different authors: CUSTOMER 1. Benefits VIAscanR to producers and WAMMCO, Rob Davidson, Supply Development Manager, David Pethick, School of Veterinary and Biomedical Studies, Murdock University. 2. Healthy fats in lamb: how WA lambs compare with others, C. F. Engelke Animal Biology, University of Western Australia, bCSIRO Livestock Industries, Western Australia B.D. Siebert, Department of Animal Science, University of Adelaide, South Australia, K. Gregg, Centre for High-Throughput Agricultural Genetic Analysis, Murdoch University, Western Australia. A-D.G. Wright CSIRO Livestock Industries, Western Australia, P.E Vercoe Animal Biology, University of Western Australia 3. Shelf life of fresh lamb meat: lamb age & electrical stimulation, Dr Robin Jacob, Department of Agriculture, Western Australia 4. Pastures from space - An evaluation of adoption of by Australian woolgrowers, Russell Barnett, Australian Venture Consultants, Joanne Sneddon, University of Western Australia 5. Your clients can learn from ASHEEP\u27s example, Sandra Brown Department of Agriculture Western Australia 6. Lifetime Wool - Farmers attitudes affect their adoption of recommended ewe management, G. Rose Department of Agriculture Western Australia, C. Kabore, Kazresearch, Lower Templestowe Vic, J. Dart, Clear Horizons, Hastings Vic 7. Sustainable certification of Australian Merino, what will customers be looking for? Stuart Adams, i-merino / iZWool International Pty Lt
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