59 research outputs found
First Beam Tests for the Prototype LHC Orbit and Trajectory System in the CERN-SPS
The first beam tests for the prototype LHC orbit and trajectory system were performed during the year 2000 in the CERN-SPS. The system is composed of a wide-bande time normaliser, which converts the analogue pick-up signals into a 10 bit position at 40 MHz, and a digital acquisition board, which is used to process and store the relevant data. This paper describes the hardware involved and presents the results of the first tests with beam
Nanoscale structure of amyloid-β plaques in Alzheimer’s disease
Abstract Soluble amyloid-β (Aβ) is considered to be a critical component in the pathogenesis of Alzheimer’s disease (AD). Evidence suggests that these non-fibrillar Aβ assemblies are implicated in synaptic dysfunction, neurodegeneration and cell death. However, characterization of these species comes mainly from studies in cellular or animal models, and there is little data in intact human samples due to the lack of adequate optical microscopic resolution to study these small structures. Here, to achieve super-resolution in all three dimensions, we applied Array Tomography (AT) and Stimulated Emission Depletion microscopy (STED), to characterize in postmortem human brain tissue non-fibrillar Aβ structures in amyloid plaques of cases with autosomal dominant and sporadic AD. Ultrathin sections scanned with super-resolution STED microscopy allowed the detection of small Aβ structures of the order of 100 nm. We reconstructed a whole human amyloid plaque and established that plaques are formed by a dense core of higher order Aβ species (~0.022 µm3) and a peripheral halo of smaller Aβ structures (~0.003 µm3). This work highlights the potential of AT-STED for human neuropathological studies
Short-Term Enrichment Makes Male Rats More Attractive, More Defensive and Alters Hypothalamic Neurons
Innate behaviors are shaped by contingencies built during evolutionary history. On the other hand, environmental stimuli play a significant role in shaping behavior. In particular, a short period of environmental enrichment can enhance cognitive behavior, modify effects of stress on learned behaviors and induce brain plasticity. It is unclear if modulation by environment can extend to innate behaviors which are preserved by intense selection pressure. In the present report we investigate this issue by studying effects of relatively short (14-days) environmental enrichment on two prominent innate behaviors in rats, avoidance of predator odors and ability of males to attract mates. We show that enrichment has strong effects on both the innate behaviors: a) enriched males were more avoidant of a predator odor than non-enriched controls, and had a greater rise in corticosterone levels in response to the odor; and b) had higher testosterone levels and were more attractive to females. Additionally, we demonstrate decrease in dendritic length of neurons of ventrolateral nucleus of hypothalamus, important for reproductive mate-choice and increase in the same in dorsomedial nucleus, important for defensive behavior. Thus, behavioral and hormonal observations provide evidence that a short period of environmental manipulation can alter innate behaviors, providing a good example of gene-environment interaction
Secret talk between adipose tissue and central nervous system via secreted factors—an emerging frontier in the neurodegenerative research
Kinetics of cellular viability in warm versus cold ischemia conditions of kidney preservation - A biometric study
Kinetic of Cellular Viability in Warm versus Cold Ischemia Condition of Kidney Preservation: A Biometric Study.
Représentations et pratiques des pédiatres face à la maltraitance infantile dans le canton de Vaud
The LHC Fast BCT system: A comparison of Design Parameters with Initial Performance
The fast beam current transformers (FBCTs) for the Large Hadron Collider (LHC) were designed to provide bunch to bunch and turn by turn intensity measurements. The required bunch to bunch measurements together with a large machine circumference call for stringent control of the transmission bandwidth, droop and DC offsets in the front-end electronics. In addition, two measurement dynamic ranges are needed to achieve the required measurement precision, increasing the complexity of the calibration. This paper reports on the analysis of the measurement and calibration methods, discusses theoretical precision limits and system limitations and provides a comparison of the theoretical results with the real data measured during the LHC start-up
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