4,999 research outputs found
LHC physics: the first one--two year(s)
We discuss the strategy to commission the LHC experiments and understand
standard physics at sqrt{s}=14TeV before data taking starts and in the early
phases of the LHC operation. In particular, we review the various steps needed
to understand and calibrate the ATLAS and CMS detectors, from construction
quality checks, to beam tests, to cosmics runs, to first collisions. We also
review the preparation and tuning of Monte Carlo tools, and present a few
examples of physics goals for integrated luminosities of up to a few inverse
fb.Comment: Proceedings of the 2nd Italian Workshop on the physics of Atlas and
CM
GRB Observed by IBIS/PICsIT in the MeV Energy Range
We present the preliminary results of a systematic search for GRB and other
transients in the publicly available data for the IBIS/PICsIT (0.2-10 MeV)
detector on board INTEGRAL. Lightcurves in 2-8 energy bands with time
resolution from 1 to 62.5 ms have been collected and an analysis of spectral
and temporal characteristics has been performed. This is the nucleus of a
forthcoming first catalog of GRB observed by PICsIT.Comment: 6 pages, 3 figures. Poster presented at COSPAR 2008. Advaces in Space
Research, accepted for publicatio
Evaluation of a combination of alfaxalone and methadone, with or without midazolam, for premedication in healthy dogs
Introduction: The study objective was to evaluate sedative and physiologic effects of midazolam associated with a combination of methadone and alfaxalone for IM premedication in dogs.
Methods: Sixteen healthy dogs of various breeds, weighing 5–12 kg, classified ASA status I-II, randomly received a combination of 0.5 mg kg−1 of methadone and 1 mg kg−1 of alfaxalone with (MMA) or without (MA) 0.5 mg kg−1 of midazolam by IM injection. Quality of sedation was assessed at 10, 15, 20 and 25 minutes post-injection, by an observer blinded to treatment. Cardiovascular, respiratory variables and additional intravenous alfaxalone required for endotracheal intubation were recorded. Data were analyzed with mixed-effect linear model on rank or Mann-Whitney rank-sum test (p≤0.05).
Results: There was no significant difference over time in heart rate, respiratory rate, systolic blood pressure, SpO2 and temperature between MA and MMA premedication. Sedation increased over time (p < 0.01), however dogs premedicated with MMA appeared significantly less sedated than dogs premedicated with MA at 15 (p=0.02), 20 (p=0.02) and 25 minutes (p=0.01) post-injection. This was substantiated by the fact that dogs premedicated with MMA were almost four times more likely to show delirium than those premedicated with MA (OR 3.95, CI 0.69-7.21, p=0.02). The amount of alfaxalone needed for intubation did not differ between treatments (p=0.92).
Conclusion: Results suggest that adding midazolam to an IM combination of methadone and alfaxalone does not improve sedation scores or amount of agent needed for intubation in healthy dogs
Impact of cooking methods of red-skinned onion on metabolic transformation of phenolic compounds and gut microbiota changes
Herein, we investigated the stability and bioaccessibility of phenolics in differently cooked red-skinned onion (RSO) and consequently their impact on the gut microbiota and metabolism of phenolics. In fact, the different processes used to cook vegetables can modify and re-arrange the molecular profiles of bioactive compounds, such as phenolics in phenolic-rich vegetables, such as RSO. Fried and grilled RSO were compared to raw RSO and a blank control and subjected to oro-gastro-intestinal digestion and subsequent colonic fermentation. For upper gut digestion, the INFOGEST protocol was used, and for lower gut fermentation, a short-term batch model, namely, MICODE (multi-unit in vitro colon gut model), was employed. During the process, phenolic compound profile (through high-resolution mass spectrometry) and colon microbiomics (qPCR of 14 core taxa) analyses were performed. According to the results, the degradation driven by the colon microbiota of RSO flavonols resulted in the accumulation of three main metabolites, i.e., 3-(3 '-hydroxyphenyl)propanoic acid, 3-(3 '-hydroxyphenyl)acetic acid and 3-(3 ',4 '-dihydroxyphenyl)acetic acid. Also, colonic fermentation of raw onions resulted in a substantial increase in beneficial taxa, which was larger compared to the heat-treated onions, particularly Lactobacillales and beneficial clostridia. Also, a higher level of inhibition of opportunistic bacteria was seen for the raw onion samples, namely, Clostridium perfringens group and Escherichia coli. Thus, our results showed that RSO, and especially the raw one, is an excellent dietary source of flavonols that are strongly metabolized by gut bacteria and can positively modulate the gut microbiota. Although additional in vivo studies are necessary, this work is one of the first to explore how RSO processed with different cooking methods can differently impact the phenolic metabolism and microbiota composition in the large intestine of humans, fine-tuning the antioxidant nature of foods
Changes in carotenoids, phenolic acids and antioxidant capacity in bread wheat doughs fermented with different lactic acid bacteria strains
Amongst the processing technologies able to improve the functional features of cereal-based foods, sourdough fermentation using Lactic Acid Bacteria (LAB) has been recently rediscovered for its beneficial effects. Wheat (Triticum aestivum L.) bread doughs were prepared using LAB strains belonging to different Lactobacillus species and changes in phenolic acid, carotenoid content and antioxidant capacity were evaluated. Two L. plantarum strains out of six were able to significantly increase carotenoid content in the dough, suggesting that a higher mobilization/solubilisation of these antioxidant compounds occurs. Within different fractions (free, soluble-conjugated, insoluble-bound), the relative distribution of ferulic acid and antioxidant activity changes depending on the specific strain. Overall, results indicate that some LAB strains cause in situ changes, significantly increasing the content of functional compounds in doughs during fermentation. This, in turn, could improve the functional features of bakery foods characterised by a high content in carotenoids and other bioactive compounds
Intermolecular interactions in the TMEM16A dimer controlling channel activity
TMEM16A and TMEM16B are plasma membrane proteins with Ca2+ -dependent Cl- channel function. By replacing the carboxy-terminus of TMEM16A with the equivalent region of TMEM16B, we obtained channels with potentiation of channel activity. Progressive shortening of the chimeric region restricted the "activating domain" to a short sequence close to the last transmembrane domain and led to TMEM16A channels with high activity at very low intracellular Ca2+ concentrations. To elucidate the molecular mechanism underlying this effect, we carried out experiments based on double chimeras, Forster resonance energy transfer, and intermolecular cross-linking. We also modeled TMEM16A structure using the Nectria haematococca TMEM16 protein as template. Our results indicate that the enhanced activity in chimeric channels is due to altered interaction between the carboxy-terminus and the first intracellular loop in the TMEM16A homo-dimer. Mimicking this perturbation with a small molecule could be the basis for a pharmacological stimulation of TMEM16A-dependent Cl- transport
Effects of the replacement of nitrates/nitrites in salami by plant extracts on colon microbiota
Salami is a cured sausage consisting of fermented and air-dried meat obtained from a mixture of meat and fat with spices and other ingredients. Excessive processed meat consumption is negatively considered because of its high fat and salt contents and few bioactive molecules. Notwithstanding, salami is largely consumed, and there is a strong interest to produce better and healthier products by substituting nitrites and nitrates with natural extracts. This work produced four different salami, two controls including nitrates and two alternative preparations where nitrates were substituted with plant extract and ascorbic acid. The products were in vitro digested with the INFOGEST protocol to simulate the oro-gastro-duodenal phase and in vitro fermented with MICODE model to simulate the colon phase. Samples were analyzed by microbiomics and metabolomics approaches to study the changes in bacterial populations and in metabolites production. The results showed that the clean-label formulations promote a general eubiosis of the intestinal microbiota, including favorable F/B ratio, the proliferation of beneficial microbial taxa (Bifidobacteriaceae), and reduction of negative microbial populations (Enterobacteriaceae). Volatilome analysis highlighted a marked production of beneficial molecules, including acetate, propionate and butyrate, and a reduction in host negative molecules such as phenol and p-cresol. Our results tell that the plant extracts could be used to replace nitrates, because the features obtained are comparable to those of controls. This work could represent an encouraging starting point for the processed meat industry for the development of clean-label formulations aimed at reducing the negative impact of these products on consumers
The potential for environmental management to contribute to malaria vector control in western Niger
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2008.Includes bibliographical references (leaves 88-93).This thesis investigated the potential for environmental management techniques to contribute to malaria vector control in Niger, with a case study on Banizoumbou village in western Niger. Numerical modeling was used to simulate habitat modifications in the form of leveling a topographic depression, ploughing the land surface to enhance infiltration and providing barriers to surface runoff on hillslopes. The hydrologic model described by Bomblies et al. (2008) was used for the modeling investigation, calibrated using environmental observations obtained in Banizoumbou for the years 2005, 2006 and 2007. The modeling investigation showed that leveling of topographic depressions could reduce the persistence time of a pool to less than the time needed for establishment of mosquito breeding, approximately 7 days. Increasing the surface soil permeability by ploughing also reduced the persistence time of the pool but was not as effective as leveling. Therefore leveling is the recommended intervention for pools of a small to intermediate size, while ploughing would be recommended for large pools where leveling would require too much work to implement. Interception of hillslope runoff using a barrier was demonstrated to be the most effective way to prevent a pool from becoming breeding habitat. However, this method has the most risk of creating unintended downstream impacts and therefore must be used with extreme caution. A field trial was also undertaken during July to September 2007 in Banizoumbou to investigate the efficacy of neem seeds as a larvicide and to reduce adult emergence from breeding pools.(cont.) The neem field trial showed that twice-weekly applications of neem seed powder to known breeding habitats of Anopheles larvae in 2007 resulted in 49% fewer adult female Anopheles gambiae s.L mosquitoes in Banizoumbou compared with previous captures under similar environmental conditions and with similar habitat characteristics in 2005 and 2006. The results of the neem field trial suggest that neem seeds could provide an appropriate, sustainable larvicide for the malaria vector An. gambiae s.I. in the Sahel region of Niger and adjacent areas having similar environmental characteristics and vector dynamics.by Rebecca L. Gianotti.S.M
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