We report on a test of a straw tube detector design having several anode (sense) wires inside a straw tube. The anode wires form a circle inside the tube and are read out independently. This design ...could solve several shortcomings of the traditional single wire straw tube design such as double hit capability and stereo configuration.
Little is known about the bovine milk proteome or whether it can be affected by diet. The objective of this study was to determine if the dietary rumen degradable protein (RDP):rumen undegradable ...protein (RUP) ratio could alter the bovine milk proteome. Six Holstein cows (parity: 2.5 ± 0.8) in mid lactation were blocked by days in milk (80 ± 43 d in milk) and milk yield (57.5 ± 6.0 kg) and randomly assigned to treatment groups. The experiment was conducted as a double-crossover design consisting of three 21-d periods. Within each period, treatment groups received diets with either (1) a high RDP:RUP ratio (RDP treatment: 62.4:37.6% of crude protein) or (2) a low RDP:RUP ratio (RUP treatment: 51.3:48.7% of crude protein). Both diets were isonitrogenous and isoenergetic (crude protein: 18.5%, net energy for lactation: 1.8 Mcal/kg of dry matter). To confirm N and energy status of cows, dry matter intake was determined daily, rumen fluid samples were collected for volatile fatty acid analysis, blood samples were collected for plasma glucose, β-hydroxybutyrate, urea nitrogen, and fatty acid analysis, and total 24-h urine and fecal samples were collected for N analysis. Milk samples were collected to determine the general milk composition and the protein profile. Milk samples collected for high-abundance protein analysis were subjected to HPLC analysis to determine the content of α-casein, β-casein, and κ-casein, as well as α-lactalbumin and β-lactoglobulin. Samples collected for low-abundance protein analysis were fractionated, enriched using ProteoMiner treatment, and separated using sodium dodecyl sulfate-PAGE. After excision and digestion, the peptides were analyzed using liquid chromatography (LC) tandem mass spectrometry (MS/MS). The LC-MS/MS data were analyzed using PROC GLIMMIX of SAS (version 9.4, SAS Institute Inc., Cary, NC) and adjusted using the MULTTEST procedure. All other parameters were analyzed using PROC MIXED of SAS. No treatment differences were observed in dry matter intake, milk yield, general milk composition, plasma parameters, or rumen volatile fatty acid concentrations, indicating no shift in total energy or protein available. Milk urea N and plasma urea N concentrations were higher in the RDP group, indicating some shift in N partitioning due to diet. A total of 595 milk proteins were identified, with 83% of these proteins known to be involved in cellular processes. Although none of the low-abundance proteins identified by LC-MS/MS were affected by diet, feeding a diet high in RUP decreased β-casein, κ-casein, and total milk casein concentration. Further investigations of the interactions between diet and the milk protein profile are needed to manipulate the milk proteome using diet.
The objective of this experiment was to identify and characterize the bovine milk proteome within the skim milk fraction and milk fat globule membrane (MFGM)-associated fraction from 16 organically ...certified lactating Jersey cows after a short term of grazing pastures with or without annual forage crops (AFC). Cows were offered a partial mixed ration (∼60% of dry matter intake) and approximately 40% of their total dry matter intake as herbage. Eight cows were offered a cool-season grass–legume herbage (GLH), which included orchardgrass (Dactylis glomerata), timothy (Phleum pratense), Kentucky bluegrass (Poa pratensis), and white clover (Trifolium repens). The other 8 cows were offered the same GLH strip-tilled with the AFC, including oat (Avena sativa), millet (Pennisetum glaucum), teff (Eragrostis tef), buckwheat (Fagopyrum esculentum), and chickling vetch (Lathyrus sativus). Milk samples were collected from each cow during a.m. and p.m. milkings on d 19 to 21 of grazing, and composite milk samples per cow were analyzed for (1) the high-abundance milk protein profile, (2) the skim milk low-abundance protein-enriched proteome, and (3) the MFGM proteome. Of the 443 proteins identified in the skim and MFGM proteomes, 433 were included in statistical analysis, including 68 proteins identified in the skim milk fraction and 365 in the MFGM-associated fraction. Analysis of the skim and MFGM proteomes encompassed unique gene ontology profiles and proportions of functional classifications. In response to diet, αS1-casein as well as 8 low-abundance proteins were present in higher concentration or abundance in milk from cows grazing the GLH strip-tilled with the AFC compared with milk from cows grazing GLH, suggesting that even short-term grazing of pastures including some AFC may affect the milk proteome.
Heat treatment of colostrum is performed on modern dairy farms to reduce pathogenic contamination before hand-feeding the colostrum to newborn calves; however, limited data are available concerning ...effects of heat treatment on biologically active proteins in colostrum. The objective of this exploratory study was to investigate effects of heat treatment and length of heat treatment on colostrum protein profile. Colostrum samples were collected from Holstein cows within 12 h after parturition and assigned to the following groups: heat treatment at 60°C for 0 (untreated control), 30, 60, or 90 min. Samples were fractionated using acid precipitation, followed by ultracentrifugation and ProteoMiner (Bio-Rad Laboratories, Hercules, CA) treatment, and tandem-mass tagging was used to comparatively assess the low abundance protein profile. A total of 162 proteins were identified with more than 2 peptides in the low abundance protein enriched fraction. Of these, 62 differed in abundance by more than 2-fold in heat-treated samples compared with the unheated control. The majority of proteins affected by heat treatment were involved in immunity, enzyme function, and transport-related processes; affected proteins included lactadherin, chitinase-3-like protein 1, and complement component C9. These results provide a foundation for further research to determine optimum heat treatment practices to ensure newborn calves are fed colostrum-containing proteins with the highest nutritional and biological value.
Aging studies for the ATLAS Transition Radiation Tracker (TRT) Akesson, T.; Barberio, E.; Bondarenko, V. ...
International Workshop on Aging Phenomena in Gaseous Detectors,Hamburg, Germany,2001-10-02 - 2001-10-05,
12/2003, Letnik:
515, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
A summary of the aging and material validation studies carried out for the ATLAS Transition Radiation Tracker (TRT) is presented. Particular emphasis is put on the different phenomena observed in ...straw tubes operating with the chosen Xe/CF
4/CO
2 mixture. The most serious effects observed are silicon deposition on the anode wire and damage of the anode wire gold plating. Etching phenomena and active radical effects are also discussed. With a careful choice of all materials and components, and with good control of the water contamination in the active gas, the ATLAS TRT will operate reliably for 10 years at the LHC design luminosity. To demonstrate this fully, more work is still needed on the gas system purification elements, in particular to understand their interplay with the active species containing fluorine created in the avalanche process under irradiation.
The ATLAS Transition Radiation Tracker (TRT) performance depends critically on the choice of the active gas and on its properties. The most important operational aspects, which have led to the final ...choice of the active gas for the operation of the TRT at the LHC design luminosity, are presented. The TRT performance expected at these conditions is reviewed, including pile-up effects at high luminosity.
A super high rate straw drift chamber Oh, S.H; Wang, C.H; Ebenstein, W.L
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/1999, Letnik:
425, Številka:
1
Journal Article
Recenzirano
We have devised a technique to read out a sense wire inside a straw tube in many independent sections without bulky plates between sections, thus reducing the occupancy considerably. Based on this ...technique, a prototype chamber is constructed, which is suitable for extremely high rate environments.
Test-beam studies of the ATLAS Transition Radiation Tracker (TRT) straw tube performance in terms of electron–pion separation using a time-over-threshold method are described. The test-beam data are ...compared with Monte Carlo simulations of charged particles passing through the straw tubes of the TRT. For energies below
10
GeV
, the time-over-threshold method combined with the standard transition-radiation cluster-counting technique significantly improves the electron–pion separation in the TRT. The use of the time-over-threshold information also provides some kaon–pion separation, thereby significantly enhancing the B-physics capabilities of the ATLAS detector.
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