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991.
The Pasteurized Milk Ordinance (PMO) mandates milk hauling sanitation and operational practices; however, the use of vague language (i.e., “as needed”) and gaps in processes lead to variability in industry practices. Our aim was to characterize industry milk hauling practices and identify areas that may be an unexplained source of contamination in the dairy processing continuum, and communicate this information with industry to cultivate best practices. The objectives of this study were to (1) survey industry hauling sanitation and operation practices in the Pacific Northwest region of the United States, and (2) quantify microbial populations [aerobic plate count (APC), lactic acid bacteria, coliforms] on the internal surfaces of transfer hoses (tanker and receiving bay) to determine their potential contribution to the microbiological quality of raw milk. Eleven facilities (78% response rate) participated in our survey. All facilities surveyed were compliant with the PMO; however, overall milk reception layout, sanitation practices, and routine maintenance greatly varied between facilities. Farm hose samples (n = 115) had significantly higher microbial loads (APC: mean 4.7 log cfu/100 cm2; median 5.1 log cfu/cm2) than receiving hose samples (n = 57; APC: mean: 2.1 log cfu/100 cm2; median 1.9 log cfu/100 cm2). Microbial populations on transfer hose surfaces did not correlate with time since last cleaning for either tanker or receiving bay hoses. Microbial content of farm hoses is likely to reflect the microbial quality of the previous milk transferred through the hose, making on-farm management practices the primary consideration to maintain low microbiological counts downstream. Upon arrival at the processor, 10% of farm hoses were missing caps. Although this did not correlate with elevated microbiological counts, uncapped farm hoses are exposed to the farm environment, provide opportunity for contamination, and are in violation of the PMO. Through observations made during our studies, manual cleaning procedures appear to be a major weakness in hauling practices and need more attention. Recognizing and communicating variability and areas of weakness allows industry to elevate their hauling sanitation and operational practices to maintain optimum milk microbiological quality. 相似文献
992.
Thomas M. Cooper Joy E. Haley David J. Stewart Stephanie Long Douglas M. Krein Aaron R. Burke Eduardo Arias Ivana Moggio Gleb Turlakov Ronald F. Ziolo Michal Biler Mathieu Linares Patrick Norman 《Advanced functional materials》2020,30(28)
The fabrication, molecular structure, and spectroscopy of a stable cholesteric liquid crystal platinum acetylide glass obtained from trans‐Pt(PEt3)2(C?C?C6H5?C?N)(C?C?C6H5?COO?Cholesterol), are described and designated as PE1‐CN‐Chol. Polarized optical microscopy, differential scanning calorimetry, and wide‐angle X‐ray scattering experiments show room temperature glassy/crystalline texture with crystal formation upon heating to 165 °C. Further heating results in conversion to cholesteric phase. Cooling to room temperature leads to the formation of a cholesteric liquid crystal glass. Scanning tunneling microscopy of a PE1‐CN‐Chol monolayer reveals self‐assembly at the solid?liquid interface with an array of two molecules arranged in pairs, oriented head‐to‐head through the CN groups, giving rise to a lamella arrangement. The lamella structure obtained from molecular dynamics calculations shows a clear phase separation between the conjugated platinum acetylide and the hydrophobic cholesterol moiety with the lamellae separation distance being 4.0 nm. Ultrafast transient absorption and flash photolysis spectra of the glass show intersystem crossing to the triplet state occurring within 100 ps following excitation. The triplet decay time of the film compared to aerated and deoxygenated solutions is consistent with oxygen quenching at the film surface but not within the film. The high chromophore concentration, high glass thermal stability, and long triplet lifetime in air show that these materials have potential as nonlinear absorbing materials. 相似文献
993.
Zsuzsanna Kuklenyik Jeffrey I. Jones Christopher A. Toth Michael S. Gardner James L. Pirkle John R. Barr 《仪器科学与技术》2018,46(1):102-114
Tandem mass spectrometry (MS/MS)-based proteomic workflows with a bottom-up approach require enzymatic digestion of proteins to peptide analytes, usually by trypsin. Online coupling of trypsin digestion of proteins, using an immobilized enzyme reactor (IMER), with liquid chromatography (LC) and MS/MS is becoming a frequently used approach. However, finding IMER digestion conditions that allow quantitative analysis of multiple proteins with wide range of endogenous concentration requires optimization of multiple interactive parameters: digestion buffer flow rate, injection volume, sample dilution, and surfactant type/concentration. In this report, we present a design of experiment approach for the optimization of an integrated IMER-LC–MS/MS platform. With bovine serum albumin as a model protein, the digestion efficacy and digestion rate were monitored based on LC–MS/MS peak area count versus protein concentration regression. The optimal parameters were determined through multivariate surface response modeling and consideration of diffusion controlled immobilized enzyme kinetics. The results may provide guidance to other users for the development of quantitative IMER-LC–MS/MS methods for other proteins. 相似文献
994.
Modern public transport networks provide an efficient medium for the spread of infectious diseases within a region. The ability to identify components of the public transit system most likely to be carrying infected individuals during an outbreak is critical for public health authorities to be able to plan for outbreaks, and control their spread. In this study we propose a novel network structure, denoted as the vehicle trip network, to capture the dynamic public transit ridership patterns in a compact form, and illustrate how it can be used for efficient detection of the high risk network components. We evaluate a range of network-based statistics for the vehicle trip network, and validate their ability to identify the routes and individual vehicles most likely to spread infection using simulated epidemic scenarios. A variety of outbreak scenarios are simulated, which vary by their set of initially infected individuals and disease parameters. Results from a case study using the public transit network from Twin Cities, MN are presented. The results indicate that the set of transit vehicle trips at highest risk of infection can be efficiently identified, and are relatively robust to the initial conditions of the outbreak. Furthermore, the methods are illustrated to be robust to two types of data uncertainty, those being passenger infection levels and travel patterns of the passengers. 相似文献
995.
International Journal of Steel Structures - The Wagner coefficient is a key parameter used to describe the inelastic lateral-torsional buckling (LTB) behaviour of the I-beam, since even for a... 相似文献
996.
Ademola Adetokunbo Oyagbemi Foluso Bolawaye Bolaji-Alabi Temitayo Olabisi Ajibade Olumuyiwa Abiola Adejumobi Olumide Samuel Ajani Theophilus Aghogho Jarikre Temidayo Olutayo Omobowale Olufunke Eunice Ola-Davies Kehinde Olugboyega Soetan Abimbola Obemisola Aro Benjamin Obukowho Emikpe Adebowale Benard Saba Adeolu Alex Adedapo Matthew Olugbenga Oyeyemi Sanah Malomile Nkadimeng Prudence Ngalula Kayoka-Kabongo Lyndy Joy McGaw Oluwafemi Omoniyi Oguntibeju Momoh Audu Yakubu 《Journal of Food Biochemistry》2020,44(12):e13534
997.
This paper presents a new and effective method to achieve fast machining simulation via the frame-sliced voxel representation (FSV-rep) workpiece modeling environment. The FSV-rep workpiece... 相似文献
998.
Daniel Cook Dale R. Gardner Michael H. Ralphs James A. Pfister Kevin D. Welch Benedict T. Green 《Journal of chemical ecology》2009,35(10):1272-1278
Locoweeds are Astragalus and Oxytropis species that contain the toxic alkaloid swainsonine. Swainsonine accumulates in all parts of the plant with the highest concentrations
found in the above ground parts. A fungal endophyte, Undifilum oxytropis, found in locoweed plant species, is responsible for the synthesis of swainsonine. By using quantitative PCR, the endophyte
can be quantified in locoweed species. Endophyte amounts differ between plant parts and in some instances do not mirror the
concentrations of swainsonine in the corresponding parts. Two groups of Oxytropis sericea were identified: one that accumulated high concentrations of swainsonine and another where swainsonine was not detected,
or concentrations were near the detection threshold. The plants with high swainsonine concentrations had quantitatively higher
amounts of endophyte. Alternatively, plants with low or no swainsonine detected had quantitatively lower endophyte amounts.
In addition, swainsonine and endophyte concentrations were not distributed uniformly within the same plant when separated
into stalks (leaves, scape(s), and flowers/pods). These findings provide evidence as to why plants in the same population
accumulate different concentrations of swainsonine, and they have important implications for sampling of locoweed plants. 相似文献
999.
1000.