235 research outputs found
In Alzheimer's disease, 6-month treatment with GLP-1 analog prevents decline of brain glucose metabolism:Randomized, placebo-controlled, double-blind clinical trial
In animal models, the incretin hormone GLP-1 affects Alzheimer’s disease (AD). We hypothesized that treatment with GLP-1 or an analog of GLP-1 would prevent accumulation of Aβ and raise, or prevent decline of, glucose metabolism (CMR(glc)) in AD. In this 26-week trial, we randomized 38 patients with AD to treatment with the GLP-1 analog liraglutide (n = 18), or placebo (n = 20). We measured Aβ load in brain with tracer [(11)C]PIB (PIB), CMR(glc) with [(18)F]FDG (FDG), and cognition with the WMS-IV scale (ClinicalTrials.gov NCT01469351). The PIB binding increased significantly in temporal lobe in placebo and treatment patients (both P = 0.04), and in occipital lobe in treatment patients (P = 0.04). Regional and global increases of PIB retention did not differ between the groups (P ≥ 0.38). In placebo treated patients CMR(glc) declined in all regions, significantly so by the following means in precuneus (P = 0.009, 3.2 μmol/hg/min, 95% CI: 5.45; 0.92), and in parietal (P = 0.04, 2.1 μmol/hg/min, 95% CI: 4.21; 0.081), temporal (P = 0.046, 1.54 μmol/hg/min, 95% CI: 3.05; 0.030), and occipital (P = 0.009, 2.10 μmol/hg/min, 95% CI: 3.61; 0.59) lobes, and in cerebellum (P = 0.04, 1.54 μmol/hg/min, 95% CI: 3.01; 0.064). In contrast, the GLP-1 analog treatment caused a numerical but insignificant increase of CMR(glc) after 6 months. Cognitive scores did not change. We conclude that the GLP-1 analog treatment prevented the decline of CMR(glc) that signifies cognitive impairment, synaptic dysfunction, and disease evolution. We draw no firm conclusions from the Aβ load or cognition measures, for which the study was underpowered
Beacon Signalling for Expedited Cell Search Procedures in NTN NB-IoT
Three cellular standards have been considered for Non-Terrestrial Networks (NTN): NB-IoT, eMTC and NR, each having had features introduced to accommodate the challenges of the NTN case. In Terrestrial Networks (TNs), it is reasonable to expect continuous coverage when a UE is stationary within reach of a base-station (eNB) with rare exceptions of downtime due to failures or catastrophic events. The same continuity cannot be assumed in NTN for sparse eNB constellations or during the rollout of dense eNB constellations. Therefore, a feature of the NTN IoT protocols - NTN NB-IoT & NTN eMTC - is the support of discontinuous RAN coverage.
Cell search is a core task of NTN UEs serviced by non-geostationary (NGSO) constellations. Initially, when UEs are booted up, unless a recent ephemeris has been provisioned to it, the UE must first discover a valid eNB by employing repeated cell searching. UEs will have to keep doing cell search each time they wish to access a cell again after losing or dropping connectivity. Intermittent coverage gaps, which occur in dense constellations due to system failures, during rollout or inherently in sparse constellations, exaggerate the number of cell search attempts required by a UE before finding an appropriate cell to camp on. These latter cases of intermittent coverage can be mitigated by the coverage prediction features for discontinuous coverage.
In this paper, a beacon signal, which can be transmitted within the white-spaces of stand-alone NB-IoT, is introduced. The beacon signal is designed to expedite the cell search procedure in NTN NB-IoT in NGSO constellations by: (1) Allowing for easy and early detection of the presence of a cell, (2) encoding preliminary information for the UE to assess whether to continue cell search at that early point and (3) providing helpful information to the synchronisation procedure. The performance of the beacon signal is simulated and evaluations show a fair improvement over utilizing legacy synchronization signals for cell detection both in terms of speed and SNR
Readout for intersatellite laser interferometry: Measuring low frequency phase fluctuations of HF signals with microradian precision
Precision phase readout of optical beat note signals is one of the core
techniques required for intersatellite laser interferometry. Future space based
gravitational wave detectors like eLISA require such a readout over a wide
range of MHz frequencies, due to orbit induced Doppler shifts, with a precision
in the order of at frequencies between
and . In this paper, we present phase
readout systems, so-called phasemeters, that are able to achieve such
precisions and we discuss various means that have been employed to reduce noise
in the analogue circuit domain and during digitisation. We also discuss the
influence of some non-linear noise sources in the analogue domain of such
phasemeters. And finally, we present the performance that was achieved during
testing of the elegant breadboard model of the LISA phasemeter, that was
developed in the scope of an ESA technology development activity.Comment: submitted to Review of Scientific Instruments on April 30th 201
Home care providers to the rescue:a novel first-responder programme
To describe the implementation of a novel first-responder programme in which home care providers equipped with automated external defibrillators (AEDs) were dispatched in parallel with existing emergency medical services in the event of a suspected out-of-hospital cardiac arrest (OHCA).We evaluated a one-year prospective study that trained home care providers in performing cardiopulmonary resuscitation (CPR) and using an AED in cases of suspected OHCA. Data were collected from cardiac arrest case files, case files from each provider dispatch and a survey among dispatched providers. The study was conducted in a rural district in Denmark.Home care providers were dispatched to 28 of the 60 OHCAs that occurred in the study period. In ten cases the providers arrived before the ambulance service and subsequently performed CPR. AED analysis was executed in three cases and shock was delivered in one case. For 26 of the 28 cases, the cardiac arrest occurred in a private home. Ninety-five per cent of the providers who had been dispatched to a cardiac arrest reported feeling prepared for managing the initial resuscitation, including use of AED.Home care providers are suited to act as first-responders in predominantly rural and residential districts. Future follow-up will allow further evaluation of home care provider arrivals and patient survival
Intensity of Melanin-Based Color and Risk of Predation in the Barn Swallow Hirundo rustica
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