4,790 research outputs found

    Modeling large Ethernet networks for the ATLAS high level trigger system using parameterized models of switches and nodes

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    Large local area Ethernet networks are strong candidates to connect data sources and processing nodes in high energy physics experiments. In the high level trigger system of the ATLAS LHC experiment several Gbytes/s of data, distributed over 1700 buffers, have to be delivered to around a thousand processing nodes. Due to the network size, its performance and scalability can only be assessed by modeling. To avoid lengthy simulation runs, and concentrate only on characteristics important for network transfers, the components of the system need to be parameterized. The network performance depends on traffic patterns generated by processing nodes and switching capabilities of the network, we therefore evaluated and modeled both processing nodes and switches. We have developed a parameterized model of a class of switches, where a limited set of parameters, collected from measurements on real devices, is used to model switching characteristics. Another set of simple measurements is used to collect values for parameters used to model processing nodes running the Linux operating system and the TCP/IP communications protocol suite. In this paper we present the set of parameters used in the models together with measuring procedures used to calibrate our models. Calibrated models are used to model small test-bed setups with random traffic to validate our approach

    The Chlamydia trachomatis Type III Secretion Chaperone Slc1 Engages Multiple Early Effectors, Including TepP, a Tyrosine-phosphorylated Protein Required for the Recruitment of CrkI-II to Nascent Inclusions and Innate Immune Signaling

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    Chlamydia trachomatis, the causative agent of trachoma and sexually transmitted infections, employs a type III secretion (T3S) system to deliver effector proteins into host epithelial cells to establish a replicative vacuole. Aside from the phosphoprotein TARP, a Chlamydia effector that promotes actin re-arrangements, very few factors mediating bacterial entry and early inclusion establishment have been characterized. Like many T3S effectors, TARP requires a chaperone (Slc1) for efficient translocation into host cells. In this study, we defined proteins that associate with Slc1 in invasive C. trachomatis elementary bodies (EB) by immunoprecipitation coupled with mass spectrometry. We identified Ct875, a new Slc1 client protein and T3S effector, which we renamed TepP (Translocated early phosphoprotein). We provide evidence that T3S effectors form large molecular weight complexes with Scl1 in vitro and that Slc1 enhances their T3S-dependent secretion in a heterologous Yersinia T3S system. We demonstrate that TepP is translocated early during bacterial entry into epithelial cells and is phosphorylated at tyrosine residues by host kinases. However, TepP phosphorylation occurs later than TARP, which together with the finding that Slc1 preferentially engages TARP in EBs leads us to postulate that these effectors are translocated into the host cell at different stages during C.trachomatis invasion. TepP co-immunoprecipitated with the scaffolding proteins CrkI-II during infection and Crk was recruited to EBs at entry sites where it remained associated with nascent inclusions. Importantly, C. trachomatis mutants lacking TepP failed to recruit CrkI-II to inclusions, providing genetic confirmation of a direct role for this effector in the recruitment of a host factor. Finally, endocervical epithelial cells infected with a tepP mutant showed altered expression of a subset of genes associated with innate immune responses. We propose a model wherein TepP acts downstream of TARP to recruit scaffolding proteins at entry sites to initiate and amplify signaling cascades important for the regulation of innate immune responses to Chlamydia.Fil: Chen, Yi-Shan. University of Duke; Estados UnidosFil: Bastidas, Robert J.. University of Duke; Estados UnidosFil: Saka, Hector Alex. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. University of Duke; Estados UnidosFil: Carpenter, Victoria K.. Duke University Medical Center; . University of Duke; Estados UnidosFil: Richards, Kristian L.. Miami University; Estados UnidosFil: Plano, Gregory V.. Miami University; Estados UnidosFil: Valdivia, Raphael H.. University of Duke; Estados Unido

    A slow mode wave as a possible source of Pi 2 and associated particle precipitation: a case study

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    International audienceAn intensification of auroral luminosity referred to as an auroral break-up often accompanies the onset of geomagnetic pulsation (Pi 2) at the dip-equator. One such auroral break-up occurred at 2239 UT on 16 June, 1986, being accompanied by weak substorm activity (AE~50 nT) which was recorded in all-sky image of Syowa Station, Antarctica (66.2°S, 71.8°E in geomagnetic coordinates). The associated Pi 2 magnetic pulsation was detected by a fluxgate magnetometer in the afternoon sector at the dip-equator (Huancayo, Peru; 1.44°N, 355.9° in geomagnetic coordinates; 12.1°S, 75.2°W in geographic coordinates; L=1.00). In spite of the large separation of the two stations in longitude and latitude, the auroral break-up and subsequent luminosity modulation were seen to be correlated with the wave form of the ground Pi 2 pulsation. This occurred in such a way that the luminosity maximum was seen to occur at the phase of maximum amplitudes of Pi 2 wave form. We argue that the observed correlation could be interpreted as indicating a Pi 2-modulation of a field-aligned acceleration of the low energy electrons that may occur near the equator of the midnight magnetosphere

    The Effects of Pregnancy and Nutritional Stress on Fat Partitioning in The Body of Ewes

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    ABSTRACT: The present study was conducted 10 deternmie the effects or pregnaaey and nutritional stress on fat partitioning in the body of man Twenty pregaant. and 2(1 non- pregnant. 3 to 4 year old Pappui Merino ewes were placed in individual pens in anwaned house The pregnant and nonpregnant ewes were allocated to inaintenance and weight loss treatment groups on the basis of their liveweight and placed ai pens. To achieve the required 20% decrease in maternal body weight it was calculated that the low nutrition animals be offered Mi% or the ration real lo the 1111altellAck: group. After adjUS11114:11t to the same maternal body weight. there was no effect of nutntion un the weights of body components Pregnancy status of the MC did affect body cOnipoS/110a, whereby the pregnant ewes had 0 75 and 0.25 kg less carcass muscle and bone respectively. Than uon-pregnant ewes Pregnant ewes had a greater weight or dissected fai in the subcutaneous depot (0.16 kg) and less in die kainay fat depot (007 kg, P.:-.(1.05) than non-pregnant ewes There was also a trend for pregnant ewes to have less fat in the mental depot (0 IN kg). although this dificrenee failed to reach significant,: (P tI (Ja5) The nutrition effect interacted with total disstaaible body fat weight Al the same total chemical body fat weight. pregnant cams had 0.22 and 0 1i1) kg more chemical fat in the subcutaneous and intmuuscular depots, respectively, and tt 05 kg less chemical fat in both the carcass muscle arid skin depots. than non-pregnant ewes Key Words FNAZ. Pregnancy. Nutritional Stress, Fat Partitionin

    Diamagnetic effects, Impulsive Alfven waves, Cavity etc, stemming from the busing of bi-directional flow burst and energetic ion injections in nighttime magnetosphere

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    第2回極域科学シンポジウム/第35回極域宙空圏シンポジウム 11月16日(水) 統計数理研究所 セミナー室

    Void formation by thermal stress concentration at twin interfaces in Cu thin films

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    科研費報告書収録論文(課題番号:13450281・基盤研究(B)(2) ・H13~H15/研究代表者:小池, 淳一/超高速LSI用Cu配線におけるボイド形成機構の研究

    Void formation by thermal stress concentration at twin interfaces in Cu thin films

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    科研費報告書収録論文(課題番号:13450281・基盤研究(B)(2) ・H13~H15/研究代表者:小池, 淳一/超高速LSI用Cu配線におけるボイド形成機構の研究

    Antibiogram of Bacteria Isolated from Patients with Lower Respiratory Tract Infection at the general outpatient department of some hospitals in Kebbi State, Nigeria

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    The rise in antibiotic resistance could be a growing public health concern among agents of respiratory tract infection, which is liable for morbidity, mortality, and costs in Africa. This study was designed to determine the antimicrobial susceptibility pattern of bacteria isolated from patients with lower respiratory tract infection (LRTI) attending some Kebbi State, Nigeria hospitals. Three hundred and fifty sputum samples were collected from consented patients with the symptoms of LRTI attending six different hospitals in Kebbi State. The samples were all screened for significant bacterial growth using standard microbiological techniques. The bacterial isolates were identified using conventional biochemical tests and then confirmed using a commercial biochemical test kit (MICROBACT) according to the manufacturer's instructions. Antimicrobial susceptibility tests were identified using the disc diffusion method. Staphylococcus aureus was the foremost predominant bacteria isolated, followed by Klebsiella pneumoniae, with an estimated percentage occurrence of 31.1% and 22.2%, respectively. Other bacteria isolated include Klebsiella oxytoca (13.9%), Escherichia coli (11.1%), Pseudomonas aeruginosa (5.6%), Aeromonas hydrophila (5.6%), Acinetobacter baumannii (4.6%), B. pseudomallei (2.8%) and Proteus spp (2.8%). Most of the isolates were ssusceptible to piperacilin (51%), trimethoprim-sulfamethoxazole (61%), Azithromycin (70%), Ciprofloxacin (71%) and Gentamycin (74%), so as of ranking. High resistance was recorded in βeta-lactam antibiotics, erythromycin and vancomycin tested. Finally, it was revealed that Staphylococcus aureus is the most predominant bacteria isolated. Most of the isolates were resistant to the β-lactam antibiotic tested. Azithromycin, Ciprofloxacin, Gentamycin, and piperacillin remain helpful antibiotics for treating LRTIs in these centers

    Effect of Methanol extract of Musca domestica larva on some Enzymes and Haematological parameters in Trypanosoma brucei brucei - infected rats

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    This study investigated the effect of methanol extract of Musca domestica (400mg/kg body weight) on some biomarker enzymes and haematological parameters in Trypanosoma brucei  brucei - infected rats. Twenty albino rats were intraperitoneally infected with Trypanosoma brucei brucei and were grouped into five (5) groups of four (4) rats each. Group1 was set up as infected not treated (0.2ml normal saline/kg body weight), group 2 was treated with diaminazene aceturate (standard drug), group 3 as prophylactic treated (treatment for 72 hours before inoculation of parasite), group 4 as early treatment with the extract (treatment commenced after the sight of parasite) and group 5 as the control (uninfected untreated) group. Results shows significant (p<0.05) decrease in liver AST and ALT activities with concomitant increase in serum activities of the infected untreated rats when compared with the early treated, prophylactic treated, standard treated and normal control. Serum ALP activity of the infected not treated group was significantly (p<0.05) higher when compared to the control group and other experimental groups. No significant (p>0.05) difference in the liver ALP activities of the extract treated infected groups with standard drug treated group However, serum and liver GGT activities of the uninfected untreated (control) was significantly lower (p<0.05) than all the other experimental groups. Haematological studies shows significant decrease (p<0.05) in packed cell volume (PCV) , haemoglobin concentration (Hb) and red blood cell count (RBC) of infected not treated when compared to infected prophylactic treated and infected early treated. There was likewise significant increase in white blood cell count (WBC) of infected not treated compared to infected prophylactic treated and infected early treated. Findings from this study showed that methanol extract of Musca domestica larva has trypanocidal properties thereby ameliorating the T. brucei induced biochemical changes in rats.Key words: Musca domestica larva, Haematology, Trypanosomiasis, Enzymes, Methanol, Extract
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