Simulation of smoke plumes from agricultural burns: application to the San Luis/Rio Colorado airshed along the U.S./Mexico border

Vegetation fires emit a number of air pollutants, thus impacting air quality at local, regional and global scales. One such pollutant is the particulate matter (PM) that is known to trigger adverse health effects. In this study, the CALPUFF/CALMET/MM5 modeling system is employed to simulate PM(10) dispersion (PM with aerodynamic diameter less than 10 microm) from agricultural fires in the Yuma/San Luis area along the U.S./Mexico border, with the aim of investigating local and regional air quality impacts of fires. To the extent possible the data collected from and observations made in the study area were employed to infer inputs to the modeling system, but insufficient information available on burning practices and input parameters, such as the duration of fire, PM(10) emission rate and plume rise, necessitated relying on some previously published research as well as the Fire Emission Production Simulator (FEPS) model to provide necessary inputs. Under the simulated conditions the fire plumes did not disperse much, and thus mostly affected the area near the sources. The PM impact of fires on populated (receptor) areas in Yuma/San Luis was less than 15 microg/m(3), calculated on the basis of EPA-recommended 24-hr averaged PM(10). If the formation of secondary particles is considered, the impacts could have been greater. In order to conduct more realistic fire plume simulations, it is imperative to have accurate fire-activity records such as the firing technique applied, fuel condition, time of burning as well as some model updates. In all, this paper presents a methodology for calculating agricultural-burns introduced PM, while identifying critical improvements that need to be made in future work.     

Post-mortem metabolism in fresh porcine, ovine and frozen bovine muscle

After slaughter, beef carcasses (n = 20) in groups of two were subjected to five treatments (one side only) including intermittent spray-chilling using water, 1% acetic acid or 1% lactic acid, or a single spray treatment with 1% acetic acid or 1% lactic acid. Intermittent spray-chilling consisted of two sprays of 30 s duration per hour for 12h. Single spray treatment consisted of one 30 s spray after entering the chill cooler. The other side of each carcass (control) was air chilled (at 2 to 3°C; air velocity 1 to 3 m/s) only. Five subprimal cuts were taken from each side at 48 h post mortem, vacuum packaged and stored for 28 days at 2°C. Intermittent sprays of sides with acetic or lactic acid resulted in significant (1.8-4.3 log/cm(2)) reductions in aerobic plate count of the strip loin, boneless rib and clod over their controls after these subprimal cuts had been vacuum packaged and stored for 28 days at 2°C in high-oxygen barrier (HOB) film. Lactobacillus spp. were dominant in the microflora of the subprimals from the control and treated sides. When sides were treated with a single sprays of acid, significant reductions in APC were noted only for some cuts of sides treated with lactic acid. After 28 days of storage, there were few significant differences in percentage purge, lean color, and off-odor scores between subprimals from control and treated sides.     

Improved immobilization yields by addition of protecting agents in glutaraldehyde-induced immobilization of protease

The effects of peptides and polyethylene glycol (PEG) on the immobilization of protease using glutaraldehyde-activated Lewatit R258-K resin were investigated. When soy peptide was added at 0.1 g/l, the activity recovery and effectiveness factor increased by 20% and 38%, respectively. When PEG4000 (0.5 g/l) was used as a protecting agent, the activity recovery and effectiveness factor were improved by 35% and 60%, respectively, leading to an increased specific activity of the immobilized enzyme. The addition of PEG4000 is suggested to improve the cost-effectiveness for the production of immobilized enzymes.     

Water distribution and mobility in meat during the conversion of muscle to meat and ageing and the impacts on fresh meat quality attributes--a review

This paper reviews current knowledge on the distribution and mobility of water in muscle (myowater) ante- and post mortem and factors affecting these in relation to fresh meat quality parameters; water-holding capacity (WHC), tenderness and juiciness. NMR transverse relaxometry (T(2)) using bench-top Low-Field Nuclear Magnetic Resonance (LF-NMR) has characterised myowater distribution and mobility as well as structural features in meat which directly affect WHC. The current literature demonstrates that WHC is correlated to the water located outside the myofibrillar network (extra-myofibrillar). This review identifies the critical stages which affect the translocation of water into the extra-myofibrillar space and thus the potential for decreased WHC during proteolysis (the conversion of muscle to meat). This review discusses how the intrinsic properties of the water held within the meat could contribute to juiciness and tenderness. Tenderness has been shown to correlate to T(2), however breed and species differences made it difficult to draw firm conclusions. Further understanding of the inherent water properties of fresh meat and the factors affecting water distribution and mobility using NMR technologies will increase the understanding of WHC and tenderisation of fresh meat.     

Spermatogenesis in testes of Dazl null mice after transplantation of wild-type germ cells

Dazl knockout male mice are infertile because their germ cells are unable to complete the first meiotic prophase in the first wave of spermatogenesis and thereafter decrease in number due to a block at the A-aligned to A1 transition. The ability of the surviving somatic components of the testes to retain their function in the absence of mature germ cells was tested by injecting marked wild-type germ cell suspensions containing spermatogonial stem cells. Comparison of the frequency and extent of colonization of Dazl knockout testes with that of testes chemically depleted of germ cells showed little if any difference. It was concluded that Dazlko testes seem unimpaired in their ability to support spermatogenesis. Therefore, Dazlko testes provide a useful and reliable recipient in which to evaluate spermatogonial stem cells. The results furthermore demonstrate that the somatic compartment of the testis of these animals retains functionality.     

Farmers' choice of medical treatment of mastitis in Danish dairy herds based on qualitative research interviews

A qualitative research study was conducted to describe and analyze farmers' perspectives on their own choices regarding decisions to have cows treated for mastitis. Through qualitative research interviews of 16 Danish dairy farmers, four levels of the decision-making process used by farmers to decide whether or not to treat a cow with antibiotics were identified. Those levels were: 1) symptom level (seriousness of the mastitis case), 2) cow level (to the extent a cow fulfilled goals of the farmer and the herd), 3) herd level (the situation of the herd, e.g., in relation to milk quota), and 4) level of alternatives (whether the farmer regards such practices as blinding of teats or homoeopathy as serious alternatives to antibiotic treatment). All four levels could be recognized in all herds, but with differing weights and relative importance across herds. Directions of different possibilities within each level also varied among farmers. By identifying those four levels, a model for understanding the farmers' choices is provided. This provides background for dialogue with each farmer about choices in the context of each specific herd. It also provides insight into implications of mastitis treatments for effective treatment versus issues of antibiotic resistance when discussing choices on a more general level. Communication and understanding between farmers and their veterinarians and cattle-oriented advisors is essential. Farmers were shown to be coherent in their choices of treatment, but their decisions often seemed to differ from normal veterinary recommendations. Such differences have to be understood and implemented into effective decisions for the whole farm.     

Characterization of Listeria monocytogenes from an ice cream plant by serotyping and pulsed-field gel electrophoresis

One dominating strain of serotype 1/2b was found when serotyping and pulsed-field gel electrophoresis (PFGE) patterns were used for the characterization of 41 Listeria monocytogenes isolates originating from an ice cream plant. Samples were taken from the production environment, equipment and ice cream during the years 1990-1997. Serotyping divided the isolates into two serovars, 1/2b and 4b. Three rare-cutting enzymes (ApaI, AscI and SmaI) were used in the creation of PFGE patterns. AscI resulted in the best restriction enzyme digestion patterns (REDPs) for visual comparison. Eight different AscI REDPs were obtained, whereas ApaI produced six and SmaI seven banding patterns. When one-band differences are taken into account, 12 different PFGE types were distinguished based on information obtained with all three enzymes. The dominant PFGE type was found to have persisted in the ice cream plant for seven years. Improved and precisely targeted cleaning and disinfection practices combined with structural changes making for easier cleaning of the packaging machine, resulted in eradication of L. monocytogenes from this plant.     

Model-driven design for the visual analysis of heterogeneous data

As heterogeneous data from different sources are being increasingly linked, it becomes difficult for users to understand how the data are connected, to identify what means are suitable to analyze a given data set, or to find out how to proceed for a given analysis task. We target this challenge with a new model-driven design process that effectively codesigns aspects of data, view, analytics, and tasks. We achieve this by using the workflow of the analysis task as a trajectory through data, interactive views, and analytical processes. The benefits for the analysis session go well beyond the pure selection of appropriate data sets and range from providing orientation or even guidance along a preferred analysis path to a potential overall speedup, allowing data to be fetched ahead of time. We illustrate the design process for a biomedical use case that aims at determining a treatment plan for cancer patients from the visual analysis of a large, heterogeneous clinical data pool. As an example for how to apply the comprehensive design approach, we present Stack'n'flip, a sample implementation which tightly integrates visualizations of the actual data with a map of available data sets, views, and tasks, thus capturing and communicating the analytical workflow through the required data sets.     

Detection of colorectal adenoma and cancer based on transthyretin and C3a-desArg serum levels

Colorectal cancer is the second leading cause of cancer death, and it develops from benign colorectal adenomas in over 95% of patients. Early detection of these cancer precursors by screening tests and their removal can potentially eradicate more than 95% of colorectal cancers before they develop. To discover sensitive and specific biomarkers for improvement of pre‐clinical diagnosis of colorectal adenoma and cancer, we analysed in two independent studies (n = 87 and n = 83 patients) serum samples from colorectal cancer (stage III), colorectal adenoma and control patients using SELDI‐TOF‐MS. Extensive statistical analysis was performed to establish homogeneous patient groups based on their clinical data. Two biomarkers that were each able to distinguish control patients from either colorectal adenoma or colorectal cancer patients (p<0.001) were identified as transthyretin (pre‐albumin) and C3a‐desArg by MS/MS and were further validated by antibody‐based assays (radial immunodiffusion, ELISA). A combination of both proteins clearly indicated the presence of colorectal adenoma or carcinoma. Using a cut‐off of <0.225 g/L for transthyretin and >1974 ng/mL for C3a‐desArg, we found a sensitivity and specificity for colorectal adenoma of 96% and 70%, respectively.