1,665 research outputs found
MiniGRAIL progress report 2004
The MiniGRAIL detector was improved. The sphere was replaced by a slightly larger one, having a diameter of 68 cm (instead of 65 cm), reducing the resonant frequency by about 200 Hz to around 2.9 kHz. The last four masses of the attenuation system were machined to increase their resonant frequency and improve the attenuation around the resonant frequency of the sphere. In the new sphere, six holes were machined on the TIGA positions for easy mounting of the transducers. During the last cryogenic run, two capacitive transducers and a calibrator were mounted on the sphere. The first transducer was coupled to a double-stage SQUID amplifier having a commercial quantum design SQUID as a first stage and a DROS as a second stage. The second transducer was read by a single-stage quantum design SQUID. During the cryogenic run, the sphere was cooled down to 4 K. The two-stage SQUID had a flux noise of about 1.6 ÎŒ0 Hzâ1/2. The detector was calibrated and the sensitivity curve of MiniGRAIL was determined
Hypotheses, evidence and relationships: The HypER approach for representing scientific knowledge claims
Biological knowledge is increasingly represented as a collection of (entity-relationship-entity) triplets. These are queried, mined, appended to papers, and published. However, this representation ignores the argumentation contained within a paper and the relationships between hypotheses, claims and evidence put forth in the article. In this paper, we propose an alternate view of the research article as a network of 'hypotheses and evidence'. Our knowledge representation focuses on scientific discourse as a rhetorical activity, which leads to a different direction in the development of tools and processes for modeling this discourse. We propose to extract knowledge from the article to allow the construction of a system where a specific scientific claim is connected, through trails of meaningful relationships, to experimental evidence. We discuss some current efforts and future plans in this area
Sensitivity of the spherical gravitational wave detector MiniGRAIL operating at 5 K
We present the performances and the strain sensitivity of the first spherical
gravitational wave detector equipped with a capacitive transducer and read out
by a low noise two-stage SQUID amplifier and operated at a temperature of 5 K.
We characterized the detector performance in terms of thermal and electrical
noise in the system output sygnal. We measured a peak strain sensitivity of
at 2942.9 Hz. A strain sensitivity of better than
has been obtained over a bandwidth of 30 Hz. We expect
an improvement of more than one order of magnitude when the detector will
operate at 50 mK. Our results represent the first step towards the development
of an ultracryogenic omnidirectional detector sensitive to gravitational
radiation in the 3kHz range.Comment: 8 pages, 5 figures, submitted to Physical Review
Other road usersâ adaptations to increase safety in response to older driversâ behaviour
Changes in physical and cognitive abilities not only challenge the driving ability of older adults, in some situations age-related changes in driving behaviour require other road users to adapt their behaviour to maintain a safe traffic situation. In this study, we aimed to map age-related differences in driving behaviour and assess the impact on other road users. A group younger and a group older adults drove four different routes containing challenging situations (e.g., merging into motorway traffic) in a driving simulator while measures of driving behaviour were collected. Other road usersâ deceleration responses to the driver's behaviour were also collected as a measure of behavioural adaptation. Our results showed similar driving performance between young and older drivers when task complexity was low, but reduced performance in older drivers when tasks requirements increased. Lower driving speed and longer waiting times that were observed in older drivers can be interpreted as compensatory behaviour aimed at creating more time to lower task requirements. Crucially, in a non-time critical situation this compensatory behaviour was found to be successful, however in a time-critical situation (merging onto a motorway) this strategy had negative side effects because other road users had to decelerate in order to keep a safe distance. Our results show the importance of anticipation and adaptation by other road users for the success of older driver's strategies and traffic safety
Pectin limits epithelial barrier disruption by Citrobacter rodentium through anti-microbial effects
SCOPE: C. rodentium is the murine equivalent of Enteropathogenic Escherichia. coli (EPEC) and Enterohemorrhagic Escherichia coli (EHEC) which induce damage to the intestinal epithelial barrier that results in diarrhea and intestinal inflammation. Dietary fibre intake can be an effective approach to limit epithelial damage by these enteric pathogens. Therefore, the protective effect of dietary fibre pectin against dysfunction of epithelial barrier integrity upon C. rodentium infection was investigated. METHODS AND RESULTS: Pectins that structurally differed in the degree and distribution of methylesters were tested on barrier protective effects on epithelial cells against C. rodentium by measuring transepithelial electrical resistance and lucifer yellow fluxes. All three pectins protected the epithelial barrier from C. rodentium induced damage in a structure-independent manner. These barrier protective effects were also independent of pectin-induced TLR2 activation. Furthermore, the pectins induced anti-adhesive effects on C. rodentium by interacting with C. rodentium and not with epithelial cells. This may be explained by antimicrobial effects of pectins on C. rodentium and not on other enteric bacteria including Lactobacillus plantarum and E. coli. A competition ELISA for binding of C. rodentium to pectin supported this finding as it showed that pectin interacts strongly with C. rodentium, whereas it interacts weakly or not with L. plantarum or E. coli. CONCLUSION: These findings demonstrate that pectin protects the epithelial barrier from C. rodentium induced damage by inducing anti-microbial effects
GCâMS profile, anti-seizure and anti-pyretic activities of palm kernel nut oil and its isolate, N-Octanoic acid from specially breed palm kernel Elaeis guineensis
PURPOSE: Palm kernel nut oil (PKNO) from palm fruit of a rare breed of Elaeis guineensis (virescens), and one of the species belonging to the Elaeis genre of arecaceae family was subjected to Gas chromatography - Mass spectroscopic studies as well as anti-seizure and anti-pyretic studies. It is used in South-Eastern part of Nigeria as antipyretic and anti-seizure agents especially in children. The aim of this study was to evaluate the chemical contents of PKNO using GC-MS and to investigate the antiseizure and antipyretic properties of PKNO using animal model.METHOD: 1500 g Palm Kernels (PK) of the rare breed collected from Abia State were cracked open and the nuts (1000 g) poured into steel vessel and heated until oil was produced after charring the nuts. The oil (PKNO) was analyzed using GC-MS to determine its chemical composition. Yeast induced hyperthermia method was used for anti-pyretic studies while strychnine sulphate induced method was used for anti-seizure studies. PKNO and Octanoic acid (0.5 mg/kg ,1 mg/kg, 2 mg/kg) were administered intraperitoneally (IP).Paracetamol (0.15mg/kg) was used as reference standard for anti-pyretic assay while epilim and tegretol (0.14mg/kg, resp.) were used as reference standards for anti-seizure assay.RESULTS: The major component identified in the extract include: Dodecanoic acid,2,3-dihydroxypropyl ester(19.36 %),n-Hexadecanoic acid(15.49 %),Dodecanoic acid( 12.51 %),Myristic acid ( 6.47 %), Dodecanedioic acid (3.93 %),n-Acetylpyrrolidone (3.67 %) , Thiazole (0.98 %) and Octanoic acid, OA ( 3.19 %).The anti-seizure results showed that doses of PKNO and OA used had Significant (p<0.02) anti-seizure activities by delaying the on-set of seizure from time of induction to time of first seizure observed. In yeast induced hyperthermia model, PKNO exhibited good level of anti-pyretic activities by direct reduction of pyrexia with the highest dose, 2.0 mg/kg. The PKNO and OA are proven to be safe till 3000 Όl/kg as indicated by LD50 results.CONCLUSION: PKNO and its components mainly fatty acids, thiazole, and n- acetylpyrrolidone are potent and promising agents with anti-pyretic and antiseizure activities.Keywords: Anti-Seizure, anti-pyretic, Octanoic acid, elaeis virescens, GC-MS, Palm kernel nut oil (PKNO
Psychophysiological measures of driver distraction and workload while intoxicated
The crash risk associated with cell phone use while driving is a contentious issue. Many states are introducing Advanced Traveler Information Systems (ATIS) that may be accessed with cell phones while driving (e.g., 511 Traveler Information Services). In these contexts, there is a need for relevant research to determine the risk of cell phone use. This study compared driver performance while conversing on a hands-free cell phone to conditions of operating common in-vehicle controls (e.g., radio, fan, air conditioning) and alcohol intoxication (BAC 0.08). In addition, the study examined the combined effects of being distracted and being intoxicated given that there may be a higher risk of a crash if the driver engages in a combination of risk factors. During simulated traffic scenarios, resource allocation was assessed through an eventrelated potential (ERP) novelty oddball paradigm. Intoxicated drivers were less attentive to all stimuli and drivers engaged in secondary tasks had weaker responses to unexpected novel sounds in brain regions associated with evaluative processing. Drivers conversing on the cell phone and in-vehicle tasks while sober had lower accuracy during the target tone task than intoxicated drivers not completing any secondary task
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