10,654 research outputs found
Cholesterol and Alzheimer's Disease Risk: A Meta-Meta-Analysis
Background: Alzheimer''s disease (AD) is the most common subtype of dementia. In the last ten years, the relationship between cholesterol and AD has been investigated. Evidence suggests that cholesterol is associated with AD and represents promising targets for intervention. However, the causality of these associations is unclear. Therefore, we sought to conduct a meta-meta-analysis to determine the effect of cholesterol on the development AD. Then, we assessed the effect of serum levels of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) and triglycerides (TG), on AD risk. Methods: A systematic search of meta-analyses was conducted. Scopus, Web of Science, Science direct, PubMed and Google academic system databases were reviewed. Results: We found 100 primary studies and five meta-analyses to analyze the relationships between cholesterol and AD. The total effect of cholesterol on risk of AD was significant and heterogeneous. Subgroup analysis shows that LDL-C levels influence the development of AD. However, non-significant effects of HDL-C, TC and TG levels on AD were found. Conclusions: These results strengthen the evidence that LDL-C cholesterol levels increase risk for AD. More initiatives to investigate the relationship between cholesterol and AD are needed
Measurement of the Stray Light in the Advanced Virgo Input Mode Cleaner Cavity using an instrumented baffle
A new instrumented baffle was installed in Spring 2021 at Virgo surrounding
the suspended mirror in the input mode cleaner triangular cavity. It serves as
a demonstrator of the technology designed to instrument the baffles in the main
arms in the near future. We present, for the first time, results on the
measured scattered light distribution inside the cavity as determined by the
new device using data collected between May and July 2021, with Virgo in
commissioning phase and operating with an input laser power in the cavity of
28.5~W. The sensitivity of the baffle is discussed and the data is compared to
scattered light simulations.Comment: 4 pages, 5 figures, 1 tabl
Strength and ductility demands on wind turbine towers due to earthquake and wind load
In earthquake prone areas, wind and earthquake loads are assumed to be statistically uncorrelated, therefore their interaction is ignored by existing design guidelines. However, the fact that strong earthquake events are commonly followed by aftershocks and that wind is constantly flowing at high speeds around wind farms increase the probability of their joint occurrence, thus making current design assumptions questionable. This investigation shows that multi-hazard scenarios magnify strength demands of wind turbine towers designed against isolated load conditions, hence modifying their performance level. It is also shown that, under certain conditions, the probabilities associated to the joint occurrence of earthquake and low to strong wind events match or exceed those related to the original design, thus rendering wind energy infrastructure susceptible to unforeseen damage
An instrumented baffle for the Advanced Virgo Input Mode Cleaner End Mirror
A novel instrumented baffle surrounding the suspended end mirror in the input
mode cleaner cavity of the Virgo interferometer was installed in spring 2021.
Since then, the device has been regularly operated in the experiment and the
obtained results indicate a good agreement with simulations of the stray light
inside the optical cavity. The baffle will operate in the upcoming O4
observation run, serving as a demonstrator of the technology designed to
instrument the baffles in front of the main mirrors in time for O5. In this
paper we present a detailed description of the baffle design, including
mechanics, front-end electronics, data acquisition, as well as optical and
vacuum tests, calibration and installation procedures, and performance results.Comment: 12 pages, 21 figures, 3 tables, to be submitted to PR
Glyphosate does not substitute for glycine in proteins of actively dividing mammalian cells
Glyphosate (N-phosphonomethyl glycine) and its commercial herbicide formulations have been shown to exert toxicity via various mechanisms. It has been asserted that glyphosate substitutes for glycine in polypeptide chains leading to protein misfolding and toxicity. However, as no direct evidence exists for glycine to glyphosate substitution in proteins, including in mammalian organisms, we tested this claim by conducting a proteomics analysis of MDA-MB-231 human breast cancer cells grown in the presence of 100 mg/L glyphosate for 6 days. Protein extracts from three treated and three untreated cell cultures were analysed as one TMT-6plex labelled sample, to highlight a specific pattern (+/+/+/−/−/−) of reporter intensities for peptides bearing true glyphosate treatment induced-post translational modifications as well as allowing an investigation of the total proteome
Mutational Analysis of the Cyanobacterial Nitrogen Regulator PipX
PipX provides a functional link between the cyanobacterial global transcriptional regulator NtcA and the signal transduction protein PII, a protein found in all three domains of life as integrators of signals of the nitrogen and carbon balance. PipX, which is toxic in the absence of PII, can form alternative complexes with NtcA and PII and these interactions are respectively stimulated and inhibited by 2-oxoglutarate, providing a mechanism by which PII can modulate expression at the NtcA regulon. Structural information on PipX-NtcA complexes suggests that PipX coactivates NtcA controlled genes by stabilizing the active conformation of NtcA bound to 2-oxoglutarate and by possibly helping recruit RNA polymerase. To get insights into PipX functions, we perform here a mutational analysis of pipX informed by the structures of PipX-PII and PipX-NtcA complexes and evaluate the impact of point mutations on toxicity and gene expression. Two amino acid substitutions (Y32A and E4A) were of particular interest, since they increased PipX toxicity and activated NtcA dependent genes in vivo at lower 2-oxoglutarate levels than wild type PipX. While both mutations impaired complex formation with PII, only Y32A had a negative impact on PipX-NtcA interactions
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
Observation of resonances consistent with pentaquark states in decays
Observations of exotic structures in the channel, that we refer to
as pentaquark-charmonium states, in decays are
presented. The data sample corresponds to an integrated luminosity of 3/fb
acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude
analysis is performed on the three-body final-state that reproduces the
two-body mass and angular distributions. To obtain a satisfactory fit of the
structures seen in the mass spectrum, it is necessary to include two
Breit-Wigner amplitudes that each describe a resonant state. The significance
of each of these resonances is more than 9 standard deviations. One has a mass
of MeV and a width of MeV, while the second
is narrower, with a mass of MeV and a width of MeV. The preferred assignments are of opposite parity, with one
state having spin 3/2 and the other 5/2.Comment: 48 pages, 18 figures including the supplementary material, v2 after
referee's comments, now 19 figure
Observation of the decay
The decay is observed in collision
data corresponding to an integrated luminosity of 3 fb recorded by the
LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first
observation of this decay channel, with a statistical significance of 15
standard deviations. The mass of the meson is measured to be
MeV/c. The branching fraction ratio
is measured to be 0.0115\,\pm\, 0.0012\, ^{+0.0005}_{-0.0009}.
In both cases, the first uncertainty is statistical and the second is
systematic. No evidence for non-resonant or decays is found.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-033.htm
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