245 research outputs found

    Temporal Brain Dynamics of Multiple Object Processing: The Flexibility of Individuation

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    The ability to process concurrently multiple visual objects is fundamental for a coherent perception of the world. A core component of this ability is the simultaneous individuation of multiple objects. Many studies have addressed the mechanism of object individuation but it remains unknown whether the visual system mandatorily individuates all relevant elements in the visual field, or whether object indexing depends on task demands. We used a neural measure of visual selection, the N2pc component, to evaluate the flexibility of multiple object individuation. In three ERP experiments, participants saw a variable number of target elements among homogenous distracters and performed either an enumeration task (Experiment 1) or a detection task, reporting whether at least one (Experiment 2) or a specified number of target elements (Experiment 3) was present. While in the enumeration task the N2pc response increased as a function of the number of targets, no such modulation was found in Experiment 2, indicating that individuation of multiple targets is not mandatory. However, a modulation of the N2pc similar to the enumeration task was visible in Experiment 3, further highlighting that object individuation is a flexible mechanism that binds indexes to object properties and locations as needed for further object processing

    The time course of exogenous and endogenous control of covert attention

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    Studies of eye-movements and manual response have established that rapid overt selection is largely exogenously driven toward salient stimuli, whereas slower selection is largely endogenously driven to relevant objects. We use the N2pc, an event-related potential index of covert attention, to demonstrate that this time course reflects an underlying pattern in the deployment of covert attention. We find that shifts of attention that occur soon after the onset of a visual search array are directed toward salient, task-irrelevant visual stimuli and are associated with slow responses to the target. In contrast, slower shifts are target-directed and are associated with fast responses. The time course of exogenous and endogenous control provides a framework in which some inconsistent results in the capture literature might be reconciled; capture may occur when attention is rapidly deployed

    Impact of prolonged sitting on vascular function in young girls

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    Excessive sedentary behaviour has serious clinical and public health implications; however, the physiological changes that accompany prolonged sitting in the child are not completely understood. Herein, we examined the acute effect a prolonged period of sitting has upon superficial femoral artery function in 7- to 10-year-old girls and the impact of interrupting prolonged sitting with exercise breaks. Superficial femoral artery endothelium-dependent flow-mediated dilatation, total shear rate, anterograde and retrograde shear rates and oscillatory shear index were assessed before and after two experimental conditions: a 3 h uninterrupted period of sitting (SIT) and a 3 h period of sitting interrupted each hour with 10 min of moderate-intensity exercise (EX). A mixed-model analysis of variance was used to compare between-condition and within-condition main effects, controlling for the within-subject nature of the experiment by including random effects for participant. Superficial femoral artery endothelium-dependent flow-mediated dilatation decreased significantly from pre- to post-SIT (mean difference 2.2% flow-mediated dilatation; 95% confidence interval = 0.60–2.94%, P < 0.001). This relative decline of 33% was abolished in the EX intervention. Shear rates were not significantly different within conditions. Our data demonstrate the effectiveness of short but regular exercise breaks in offsetting the detrimental effects of uninterrupted sitting in young girls

    The prevalence of pelvic organ prolapse symptoms and signs and their relation with bladder and bowel disorders in a general female population

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    Contains fulltext : 81191.pdf (publisher's version ) (Closed access)INTRODUCTION AND HYPOTHESIS: In selected populations, pelvic organ prolapse (POP) was associated with bladder/bowel symptoms, but data on the general female population are lacking. Our aim was to obtain normative data on the prevalence of POP and pelvic floor dysfunction (PFD) symptoms and signs and to identify associations. METHODS: Validated questionnaires on POP and PFD (urogenital distress inventory, (UDI) and defaecation distress inventory (DDI)) were sent to a general population of 2,979 women (aged 45-85 years). Data were analysed using the Kruskal-Wallis test, chi square test and Spearman's rank correlation coefficient. RESULTS: Response rate was 62.7%. Associations between POP stage and parity (0.002) and vaginal bulging (<0.001) are significant. Anatomical locations of POP and PFD symptoms correlated significantly with incontinence of flatus, feeling anal prolapse, manual evacuation of stool, vaginal bulging, constipation and pain during faecal urge (p < or = 0.005). CONCLUSIONS: Strategies should be developed to alleviate obstructive bowel disorders associated with POP

    The socio-spatial design of community and governance: Interdisciplinary urban design in China

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    This book proposes a new interdisciplinary understanding of urban design in China based on a study of the transformative effects of socio-spatial design and planning on communities and their governance. This is framed by an examination of the social projects, spaces, and realities that have shaped three contexts critical to the understanding of urban design problems in China: the histories of “collective forms” and “collective spaces”, such as that of the urban danwei (work-unit), which inform current community building and planning; socio-spatial changes in urban and rural development; and disparate practices of “spatialised governmentality”. These contexts and an attendant transformation from planning to design and from government to governance, define the current urban design challenges found in the dominant urban xiaoqu (small district) and shequ (community) development model. Examining the histories, transformations, and practices that have shaped socio-spatial epistemologies and experiences in China – including a specific sense of community and place that is rather based on a concrete “collective” than abstract “public” space and underpinned by socialised governance – this book brings together a diverse range of observations, thoughts, analyses, and projects by urban researchers and practitioners. Thereby discussing emerging interdisciplinary urban design practices in China, this book offers a valuable resource for all academics, practitioners, and stakeholders with an interest in socio-spatial design and development

    PI3Ks Maintain the Structural Integrity of T-Tubules in Cardiac Myocytes

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    Phosphoinositide 3-kinases (PI3Ks) regulate numerous physiological processes including some aspects of cardiac function. Although regulation of cardiac contraction by individual PI3K isoforms has been studied, little is known about the cardiac consequences of downregulating multiple PI3Ks concurrently.Genetic ablation of both p110α and p110β in cardiac myocytes throughout development or in adult mice caused heart failure and death. Ventricular myocytes from double knockout animals showed transverse tubule (T-tubule) loss and disorganization, misalignment of L-type Ca(2+) channels in the T-tubules with ryanodine receptors in the sarcoplasmic reticulum, and reduced Ca(2+) transients and contractility. Junctophilin-2, which is thought to tether T-tubules to the sarcoplasmic reticulum, was mislocalized in the double PI3K-null myocytes without a change in expression level.PI3K p110α and p110β are required to maintain the organized network of T-tubules that is vital for efficient Ca(2+)-induced Ca(2+) release and ventricular contraction. PI3Ks maintain T-tubule organization by regulating junctophilin-2 localization. These results could have important medical implications because several PI3K inhibitors that target both isoforms are being used to treat cancer patients in clinical trials

    Nuclear expression of Rac1 in cervical premalignant lesions and cervical cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Abnormal expression of Rho-GTPases has been reported in several human cancers. However, the expression of these proteins in cervical cancer has been poorly investigated. In this study we analyzed the expression of the GTPases Rac1, RhoA, Cdc42, and the Rho-GEFs, Tiam1 and beta-Pix, in cervical pre-malignant lesions and cervical cancer cell lines.</p> <p>Methods</p> <p>Protein expression was analyzed by immunochemistry on 102 cervical paraffin-embedded biopsies: 20 without Squamous Intraepithelial Lesions (SIL), 51 Low- grade SIL, and 31 High-grade SIL; and in cervical cancer cell lines C33A and SiHa, and non-tumorigenic HaCat cells. Nuclear localization of Rac1 in HaCat, C33A and SiHa cells was assessed by cellular fractionation and Western blotting, in the presence or not of a chemical Rac1 inhibitor (NSC23766).</p> <p>Results</p> <p>Immunoreacivity for Rac1, RhoA, Tiam1 and beta-Pix was stronger in L-SIL and H-SIL, compared to samples without SIL, and it was significantly associated with the histological diagnosis. Nuclear expression of Rac1 was observed in 52.9% L-SIL and 48.4% H-SIL, but not in samples without SIL. Rac1 was found in the nucleus of C33A and SiHa cells but not in HaCat cells. Chemical inhibition of Rac1 resulted in reduced cell proliferation in HaCat, C33A and SiHa cells.</p> <p>Conclusion</p> <p>Rac1 is expressed in the nucleus of epithelial cells in SILs and cervical cancer cell lines, and chemical inhibition of Rac1 reduces cellular proliferation. Further studies are needed to better understand the role of Rho-GTPases in cervical cancer progression.</p

    An AP-MS- and BioID-compatible MAC-tag enables comprehensive mapping of protein interactions and subcellular localizations

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    Protein-protein interactions govern almost all cellular functions. These complex networks of stable and transient associations can be mapped by affinity purification mass spectrometry (AP-MS) and complementary proximity-based labeling methods such as BioID. To exploit the advantages of both strategies, we here design and optimize an integrated approach combining AP-MS and BioID in a single construct, which we term MAC-tag. We systematically apply the MAC-tag approach to 18 subcellular and 3 sub-organelle localization markers, generating a molecular context database, which can be used to define a protein's molecular location. In addition, we show that combining the AP-MS and BioID results makes it possible to obtain interaction distances within a protein complex. Taken together, our integrated strategy enables the comprehensive mapping of the physical and functional interactions of proteins, defining their molecular context and improving our understanding of the cellular interactome.Peer reviewe

    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion related to the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA)

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    &lt;p&gt;Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to deliver a scientific opinion on the Tolerable Upper Intake Level (UL) of the n-3 LCPUFAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA). Available data are insufficient to establish a UL for n-3 LCPUFA (individually or combined) for any population group. At observed intake levels, consumption of n-3 LCPUFA has not been associated with adverse effects in healthy children or adults. Long-term supplemental intakes of EPA and DHA combined up to about 5 g/day do not appear to increase the risk of spontaneous bleeding episodes or bleeding complications, or affect glucose homeostasis immune function or lipid peroxidation, provided the oxidative stability of the n-3 LCPUFAs is guaranteed. Supplemental intakes of EPA and DHA combined at doses of 2 6 g/day, and of DHA at doses of 2 4 g/day, induce an increase in LDL-cholesterol concentrations of about 3 % which may not have an adverse effect on cardiovascular disease risk, whereas EPA at doses up to 4 g/day has no significant effect on LDL cholesterol. Supplemental intakes of EPA and DHA combined at doses up to 5 g/day, and supplemental intakes of EPA alone up to 1.8 g/day, do not raise safety concerns for adults. Dietary recommendations for EPA and DHA based on cardiovascular risk considerations for European adults are between 250 and 500 mg/day. Supplemental intakes of DHA alone up to about 1 g/day do not raise safety concerns for the general population. No data are available for DPA when consumed alone. In the majority of the human studies considered, fish oils, also containing DPA in generally unknown (but relatively low) amounts, were the source of EPA and DHA.&lt;/p&gt
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