25 research outputs found

    Does Habitual Physical Activity Increase the Sensitivity of the Appetite Control System? A Systematic Review.

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    BACKGROUND: It has been proposed that habitual physical activity improves appetite control; however, the evidence has never been systematically reviewed. OBJECTIVE: To examine whether appetite control (e.g. subjective appetite, appetite-related peptides, food intake) differs according to levels of physical activity. DATA SOURCES: Medline, Embase and SPORTDiscus were searched for articles published between 1996 and 2015, using keywords pertaining to physical activity, appetite, food intake and appetite-related peptides. STUDY SELECTION: Articles were included if they involved healthy non-smoking adults (aged 18-64 years) participating in cross-sectional studies examining appetite control in active and inactive individuals; or before and after exercise training in previously inactive individuals. STUDY APPRAISAL AND SYNTHESIS: Of 77 full-text articles assessed, 28 studies (14 cross-sectional; 14 exercise training) met the inclusion criteria. RESULTS: Appetite sensations and absolute energy intake did not differ consistently across studies. Active individuals had a greater ability to compensate for high-energy preloads through reductions in energy intake, in comparison with inactive controls. When physical activity level was graded across cross-sectional studies (low, medium, high, very high), a significant curvilinear effect on energy intake (z-scores) was observed. LIMITATIONS: Methodological issues existed concerning the small number of studies, lack of objective quantification of food intake, and various definitions used to define active and inactive individuals. CONCLUSION: Habitually active individuals showed improved compensation for the energy density of foods, but no consistent differences in appetite or absolute energy intake, in comparison with inactive individuals. This review supports a J-shaped relationship between physical activity level and energy intake. Further studies are required to confirm these findings. PROSPERO REGISTRATION NUMBER: CRD42015019696

    Acoustic Oddball during NREM Sleep: A Combined EEG/fMRI Study

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    Background: A condition vital for the consolidation and maintenance of sleep is generally reduced responsiveness to external stimuli. Despite this, the sleeper maintains a level of stimulus processing that allows to respond to potentially dangerous environmental signals. The mechanisms that subserve these contradictory functions are only incompletely understood. Methodology/Principal Findings: Using combined EEG/fMRI we investigated the neural substrate of sleep protection by applying an acoustic oddball paradigm during light NREM sleep. Further, we studied the role of evoked K-complexes (KCs), an electroencephalographic hallmark of NREM sleep with a still unknown role for sleep protection. Our main results were: (1) Other than in wakefulness, rare tones did not induce a blood oxygenation level dependent (BOLD) signal increase in the auditory pathway but a strong negative BOLD response in motor areas and the amygdala. (2) Stratification of rare tones by the presence of evoked KCs detected activation of the auditory cortex, hippocampus, superior and middle frontal gyri and posterior cingulate only for rare tones followed by a KC. (3) The typical high frontocentral EEG deflections of KCs were not paralleled by a BOLD equivalent. Conclusions/Significance: We observed that rare tones lead to transient disengagement of motor and amygdala responses during light NREM sleep. We interpret this as a sleep protective mechanism to delimit motor responses and to reduce the sensitivity of the amygdala towards further incoming stimuli. Evoked KCs are suggested to originate from a brain state wit

    CD4-Specific Designed Ankyrin Repeat Proteins Are Novel Potent HIV Entry Inhibitors with Unique Characteristics

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    Here, we describe the generation of a novel type of HIV entry inhibitor using the recently developed Designed Ankyrin Repeat Protein (DARPin) technology. DARPin proteins specific for human CD4 were selected from a DARPin DNA library using ribosome display. Selected pool members interacted specifically with CD4 and competed with gp120 for binding to CD4. DARPin proteins derived in the initial selection series inhibited HIV in a dose-dependent manner, but showed a relatively high variability in their capacity to block replication of patient isolates on primary CD4 T cells. In consequence, a second series of CD4-specific DARPins with improved affinity for CD4 was generated. These 2nd series DARPins potently inhibit infection of genetically divergent (subtype B and C) HIV isolates in the low nanomolar range, independent of coreceptor usage. Importantly, the actions of the CD4 binding DARPins were highly specific: no effect on cell viability or activation, CD4 memory cell function, or interference with CD4-independent virus entry was observed. These novel CD4 targeting molecules described here combine the unique characteristics of DARPins—high physical stability, specificity and low production costs—with the capacity to potently block HIV entry, rendering them promising candidates for microbicide development

    Search for a new gauge boson in π0\pi^{0} decays

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    A search was made for a new light gauge boson XX which might be produced in π0→γ+X\pi^{0}\to\gamma + X decay from neutral pions generated by 450-GeV protons in the CERN SPS neutrino target. The X's would penetrate the downstream shielding and be observed in the NOMAD detector via the Primakoff effect, in the process of X→π0X \to\pi^{0} conversion in the external Coulomb field of a nucleus. With 1.45×10181.45\times10^{18} protons on target, 20 candidate events with energy between 8 and 140 GeV were found from the analysis of neutrino data. This number is in agreement with the expectation of 18.1±\pm2.8 background events from standard neutrino processes. A new 90% C.L. upper limit on the branching ratio Br(π0→γ+X)<(3.3to1.9)×10−5Br(\pi^{0}\to\gamma + X)< (3.3 to 1.9) \times10^{-5} for XX masses ranging from 0 to 120 MeV/c^2 is obtained.Comment: 15 pages, LaTex, 6 eps figures included, submitted to Physics Letters

    A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment

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    We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions (v(mu)n -> mu(-)p and (v) over bar mu p -> mu(+)n) using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total v(mu) ((v) over bar mu) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti) neutrino energy interval 3-100 GeV are v(mu) = (0.92 +/- 0.02(stat) +/- 0.06(syst)) x 10(-38) cm(2) and (v) over bar (mu) = (0.81 +/- 0.05(stat) +/- 0.09(syst)) x 10(-38) cm(2) for neutrino and antineutrino, respectively. The axial mass parameter M(A) was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M(A) = 1.05 +/- 0.02(stat)+/- 0.06(syst) GeV. It is consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q(2) shape analysis of the high purity sample of v(mu) quasi-elastic 2-track events, but has smaller systematic error and should be quoted as the main result of this work. Our measured MA is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of MA is lower than those recently published by K2K and Mini-BooNE Collaborations. However, within the large errors quoted by these experiments on MA, these results are compatible with the more precise NOMAD value

    Heat-pipe earth

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    The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics. © 2013 Macmillan Publishers Limited. All rights reserved.Link_to_subscribed_fulltex

    Electroweak parameters of the z0 resonance and the standard model

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    Contains fulltext : 124399.pdf (publisher's version ) (Open Access
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