Design and characteristics of the twice-over rotation grazing system

R-1006; This circular focuses on designing twice-over rotation grazin

Tracked vehicle effects on vegetation and soil characteristics

A 3-year experiment to evaluate tracked vehicle effects on vegetation and soil characteristics was established on the Gilbert C. Grafton South State Military Reservation (CGS) in North Dakota. Study objectives were to evaluate the effects of 3 tracked vehicle use intensity treatments on plant species cover and frequency, and soil compaction. The 3 treatments evaluated include heavy use (74 passes), moderate use (37 passes) and no use. The moderate use treatment represents a typical use of 1 battalion unit at CGS with the heavy use treatment classified as 2 battalion units. This land area comprised a 50 by 150 meter block subdivided into three, 50 by 50 meter blocks. Each 50 by 50 meter block was subdivided into three, 16.7 by 50 meter blocks with each block treated with 1 of the 3 treatments. Soil bulk density increased (P \u3c 0.05) on the moderate and heavy use treatments in the 0 to 15, 30 to 45, and 45 to 60 cm soil depths. Kentucky bluegrass (Poa pratensis L.) cover (P \u3c 0.05) decreased in 1996 on both the moderate and heavy use treatments but was not (P \u3e 0.05) different among all treatments in 1997. The tracked vehicle use on the heavy and moderate treatments did not change species composition or litter amounts after 2 years; however, bulk density and bare ground increased on both treatments in 1996 and 1997. Se establecio un experimento de 3 aiios en la Reservacion Militar Estatal Gilbert C. Grafon (CGS) de North Dakota para evaluar los efectos del paso de vehaiculos militares en la vegetacion y suelo. Los objetivos del estudio fueron evaluar los efectos de 3 intensidades de paso de vehaiculos militares en la cobertura y frecuencia de especies vegetales y la compactacion del suelo. Los 3 tratamientos evaluados fueron: uso alto (74 pasos), uso moderado (37 pasos) y sin uso. El uso moderado representa el uso taipico de una unidad de batallon en el CGS y el tratamiento de uso alto representa el paso de dos unidades de batallon. El aea experimental fue un bloque de 50 x 150 m dividido en tres bloques, cada bloque de 50 x 50 m se subdividido en 3 bloques de 16.7 x 50 m y en cada uno de estos bloque se aplico uno de los tratamientos. La densidad aparente del suelo a las profundidades de 0-15, 30-45 y 45-60 cm aumento (P \u3c 0.05) en los tratamientos de uso moderado y alto. En 1996, la cobertura del zacate Kentucky bluegrass (Poa pratensis L.) disminuyo (P \u3c 0 .05) en los tratamientos de uso moderado y alto, pero en 1997 la cobertura de esta especie no difirio entre tratamientos (P \u3e 0.05). Despues de 2 anios, el uso moderado y alto de vehaiculos militares no cambio la composicion de especies ni la cantidad de mantillo; sin embargo, la densidad aparente y el suelo desnudo aumento en ambos tratamientos en 1996 y 1997

RNA dependent DNA synthesis in cell free preparations of human leukemia cells

A cell free preparation of human leukemic cells, grown in tissue culture, incorporated H3-thymidine phosphate into an acid insoluble product which was rendered acid soluble by the action of DNAase but not KOH or RNAase. RNAase, if added before incubation of the reaction mixture, prevented incorporation of the isotope into the product. For maximum incorporation Mg and all four deoxyribonucleotide triphosphates must be present. The enzyme has the properties of an RNA dependent DNA polymerase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33705/1/0000217.pd

What We Believe

https://digitalcommons.acu.edu/crs_books/1379/thumbnail.jp

Prevalence of Campylobacter and Salmonella in African food animals and meat: a systematic review and meta-analysis

Background: Campylobacter and Salmonella, particularly non-typhoidal Salmonella, are important bacterial enteric pathogens of humans which are often carried asymptomatically in animal reservoirs. Bacterial foodborne infections, including those derived from meat, are associated with illness and death globally but the burden is disproportionately high in Africa. Commercial meat production is increasing and intensifying in many African countries, creating opportunities and threats for food safety. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, we searched six databases for English language studies published through June 2016, that reported Campylobacter or Salmonella carriage or infection prevalence in food animals and contamination prevalence in food animal products from African countries. A random effects meta-analysis and multivariable logistic regression were used to estimate the species-specific prevalence of Salmonella and Campylobacter and assess relationships between sample type and region and the detection or isolation of either pathogen. Results: Seventy-three studies reporting Campylobacter and 187 studies reporting Salmonella across 27 African countries were represented. Adjusted prevalence calculations estimate Campylobacter detection in 37.7% (95% CI 31.6–44.3) of 11,828 poultry samples; 24.6% (95% CI 18.0–32.7) of 1975 pig samples; 17.8% (95% CI 12.6–24.5) of 2907 goat samples; 12.6% (95% CI 8.4–18.5) of 2382 sheep samples; and 12.3% (95% CI 9.5–15.8) of 6545 cattle samples. Salmonella were detected in 13.9% (95% CI 11.7–16.4) of 25,430 poultry samples; 13.1% (95% CI 9.3–18.3) of 5467 pig samples; 9.3% (95% CI 7.2–12.1) of 2988 camel samples; 5.3% (95% CI 4.0–6.8) of 72,292 cattle samples; 4.8% (95% CI 3.6–6.3) of 11,335 sheep samples; and 3.4% (95% CI 2.2–5.2) of 4904 goat samples. ‘External’ samples (e.g. hide, feathers) were significantly more likely to be contaminated by both pathogens than ‘gut’ (e.g. faeces, cloaca) while meat and organs were significantly less likely to be contaminated than gut samples. Conclusions: This study demonstrated widespread prevalence of Campylobacter species and Salmonella serovars in African food animals and meat, particularly in samples of poultry and pig origin. Source attribution studies could help ascertain which food animals are contributing to human campylobacteriosis and salmonellosis and direct potential food safety interventions

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells

Dengue illness impacts daily human mobility patterns in Iquitos, Peru

Background Human mobility plays a central role in shaping pathogen transmission by generating spatial and/or individual variability in potential pathogen-transmitting contacts. Recent research has shown that symptomatic infection can influence human mobility and pathogen transmission dynamics. Better understanding the complex relationship between symptom severity, infectiousness, and human mobility requires quantification of movement patterns throughout infectiousness. For dengue virus (DENV), human infectiousness peaks 0–2 days after symptom onset, making it paramount to understand human movement patterns from the beginning of illness. Methodology and principal findings Through community-based febrile surveillance and RT-PCR assays, we identified a cohort of DENV+ residents of the city of Iquitos, Peru (n = 63). Using retrospective interviews, we measured the movements of these individuals when healthy and during each day of symptomatic illness. The most dramatic changes in mobility occurred during the first three days after symptom onset; individuals visited significantly fewer locations (Wilcoxon test, p = 0.017) and spent significantly more time at home (Wilcoxon test, p = 0.005), compared to when healthy. By 7–9 days after symptom onset, mobility measures had returned to healthy levels. Throughout an individual’s symptomatic period, the day of illness and their subjective sense of well-being were the most significant predictors for the number of locations and houses they visited. Conclusions/Significance Our study is one of the first to collect and analyze human mobility data at a daily scale during symptomatic infection. Accounting for the observed changes in human mobility throughout illness will improve understanding of the impact of disease on DENV transmission dynamics and the interpretation of public health-based surveillance data