Breed Ancestry, Divergence, Admixture, and Selection Patterns of the Simbra Crossbreed.

In this study, we evaluated an admixed South African Simbra crossbred population, as well as the Brahman (Indicine) and Simmental (Taurine) ancestor populations to understand their genetic architecture and detect genomic regions showing signatures of selection. Animals were genotyped using the Illumina BovineLD v2 BeadChip (7K). Genomic structure analysis confirmed that the South African Simbra cattle have an admixed genome, composed of 5/8 Taurine and 3/8 Indicine, ensuring that the Simbra genome maintains favorable traits from both breeds. Genomic regions that have been targeted by selection were detected using the linkage disequilibrium-based methods iHS and Rsb. These analyses identified 10 candidate regions that are potentially under strong positive selection, containing genes implicated in cattle health and production (e.g., TRIM63, KCNA10, NCAM1, SMIM5, MIER3, and SLC24A4). These adaptive alleles likely contribute to the biological and cellular functions determining phenotype in the Simbra hybrid cattle breed. Our data suggested that these alleles were introgressed from the breed's original indicine and taurine ancestors. The Simbra breed thus possesses derived parental alleles that combine the superior traits of the founder Brahman and Simmental breeds. These regions and genes might represent good targets for ad-hoc physiological studies, selection of breeding material and eventually even gene editing, for improved traits in modern cattle breeds. This study represents an important step toward developing and improving strategies for selection and population breeding to ultimately contribute meaningfully to the beef production industry.

An assessment of nurse-led triage at Connaught Hospital, Sierra Leone in the immediate post-Ebola period.

INTRODUCTION: Nurse-led triage, using the South African Triage Scale, was introduced to the emergency centre of the tertiary referral hospital in Freetown, Sierra Leone in early 2014 prior to the Ebola epidemic. The aim of this study was to measure the effectiveness of the process now that the country has been declared free of Ebola. METHODS: The study was conducted over a five-day consecutive period in the adult emergency centre of the main government teaching hospital in December 2015. The times from arrival to triage and medical assessment were recorded and compared for each triage category. We also assessed the inter-rater reliability of the process. RESULTS: 111 patients were included during the study period. In terms of acuity, 6% were categorised as red, 27% were orange, 20% yellow and 47% green. Triage Early Warning Score was correctly calculated in 90% of cases and there was inter-rater agreement of colour code and triage category on 92% of occasions (k = 0.877, p < 0.001). Median time from triage to assessment was 15 min for red patients, 20 min for orange, 40 min for yellow and 72 min for green. DISCUSSION: The triage process is functioning effectively in the emergency centre after the Ebola epidemic and provides a reliable assessment of undifferentiated patients presenting to the hospital to ensure that they are seen in a timely manner based on acuity.

INTRODUCTION: Le triage réalisé par les infirmières, qui se base sur l'Echelle de triage sud-africaine (SATS, South African Triage Scale), a été introduit au service des urgences de l'hôpital tertiaire de référence de Freetown, en Sierra Leone, au début d'année 2014, avant l'épidémie d'Ebola. L'objectif était d'évaluer l'efficacité du processus maintenant que le risque pour le pays a été déclaré inexistant.Méthodes : L'étude a été menée sur une période consécutive de cinq jours au service des urgences du principal hôpital universitaire public en décembre 2015. Le temps écoulé entre l'arrivée et le triage et l'examen médical a été consigné et comparé pour chaque catégorie de triage. Nous avons également évalué le coefficient d'objectivité du processus. RÉSULTATS: 111 patients ont été inclus sur la période de l'étude. En termes de gravité, 6 % étaient classés en rouge, 27 % en orange, 20 % en jaune et 47 % en vert. La note accordée aux alertes rapides découlant du triage (TEWS, Triage Early Warning Score) a été correctement calculée dans 90 % des cas et la concordance inter-évaluateurs sur les codes couleurs et les catégories de triage a été observée dans 92 % des cas (k = 0,877, p < 0,001). Le temps moyen du triage à l'examen était de 15 minute pour les patients en catégorie rouge, de 20 minute en catégorie orange, 40 minute en catégorie jaune et 72 minute en catégorie verte. DISCUSSION: Le processus de triage fonctionne efficacement au service des urgences après l'épidémie d'Ebola et fournit une évaluation fiable des patients non différentiés se présentant à l'hôpital, afin de s'assurer qu'ils voient un médecin en temps opportun en fonction de la gravité de leur état.

The pentose phosphate pathway leads to enhanced succinic acid flux in biofilms of wild-type Actinobacillus succinogenes.

Increased pentose phosphate pathway flux, relative to total substrate uptake flux, is shown to enhance succinic acid (SA) yields under continuous, non-growth conditions of Actinobacillus succinogenes biofilms. Separate fermentations of glucose and xylose were conducted in a custom, continuous biofilm reactor at four different dilution rates. Glucose-6-phosphate dehydrogenase assays were performed on cell extracts derived from in situ removal of biofilm at each steady state. The results of the assays were coupled to a kinetic model that revealed an increase in oxidative pentose phosphate pathway (OPPP) flux relative to total substrate flux with increasing SA titre, for both substrates. Furthermore, applying metabolite concentration data to metabolic flux models that include the OPPP revealed similar flux relationships to those observed in the experimental kinetic analysis. A relative increase in OPPP flux produces additional reduction power that enables increased flux through the reductive branch of the TCA cycle, leading to increased SA yields, reduced by-product formation and complete closure of the overall redox balance.

Succinic acid production on xylose-enriched biorefinery streams by Actinobacillus succinogenes in batch fermentation.

BACKGROUND: Co-production of chemicals from lignocellulosic biomass alongside fuels holds promise for improving the economic outlook of integrated biorefineries. In current biochemical conversion processes that use thermochemical pretreatment and enzymatic hydrolysis, fractionation of hemicellulose-derived and cellulose-derived sugar streams is possible using hydrothermal or dilute acid pretreatment (DAP), which then offers a route to parallel trains for fuel and chemical production from xylose- and glucose-enriched streams. Succinic acid (SA) is a co-product of particular interest in biorefineries because it could potentially displace petroleum-derived chemicals and polymer precursors for myriad applications. However, SA production from biomass-derived hydrolysates has not yet been fully explored or developed. RESULTS: Here, we employ Actinobacillus succinogenes 130Z to produce succinate in batch fermentations from various substrates including (1) pure sugars to quantify substrate inhibition, (2) from mock hydrolysates similar to those from DAP containing single putative inhibitors, and (3) using the hydrolysate derived from two pilot-scale pretreatments: first, a mild alkaline wash (deacetylation) followed by DAP, and secondly a single DAP step, both with corn stover. These latter streams are both rich in xylose and contain different levels of inhibitors such as acetate, sugar dehydration products (furfural, 5-hydroxymethylfurfural), and lignin-derived products (ferulate, p-coumarate). In batch fermentations, we quantify succinate and co-product (acetate and formate) titers as well as succinate yields and productivities. We demonstrate yields of 0.74 g succinate/g sugars and 42.8 g/L succinate from deacetylated DAP hydrolysate, achieving maximum productivities of up to 1.27 g/L-h. Moreover, A. succinogenes is shown to detoxify furfural via reduction to furfuryl alcohol, although an initial lag in succinate production is observed when furans are present. Acetate seems to be the main inhibitor for this bacterium present in biomass hydrolysates. CONCLUSION: Overall, these results demonstrate that biomass-derived, xylose-enriched hydrolysates result in similar yields and titers but lower productivities compared to clean sugar streams, which can likely be improved via fermentation process developments and metabolic engineering. Overall, this study comprehensively examines the behavior of A. succinogenes on xylose-enriched hydrolysates on an industrially relevant, lignocellulosic feedstock, which will pave the way for future work toward eventual SA production in an integrated biorefinery.

Continuous succinic acid production from xylose by Actinobacillus succinogenes.

Continuous, anaerobic fermentations of D-xylose were performed by Actinobacillus succinogenes 130Z in a custom, biofilm reactor at dilution rates of 0.05, 0.10 and 0.30 h(-1). Succinic acid yields on xylose (0.55-0.68 g g(-1)), titres (10.9-29.4 g L(-1)) and productivities (1.5-3.4 g L(-1) h(-1)) were lower than those of a previous study on glucose, but product ratios (succinic acid/acetic acid = 3.0-5.0 g g(-1)) and carbohydrate consumption rates were similar. Also, mass balance closures on xylose were up to 18.2 % lower than those on glucose. A modified HPLC method revealed pyruvic acid excretion at appreciable concentrations (1.2-1.9 g L(-1)) which improved the mass balance closure by up to 16.8 %. Furthermore, redox balances based on the accounted xylose consumed and the excreted metabolites, indicated an overproduction of reducing power. The oxidative pentose phosphate pathway was shown to be a plausible source of the additional reducing power.

Continuous succinic acid production by Actinobacillus succinogenes on xylose-enriched hydrolysate.

BACKGROUND: Bio-manufacturing of high-value chemicals in parallel to renewable biofuels has the potential to dramatically improve the overall economic landscape of integrated lignocellulosic biorefineries. However, this will require the generation of carbohydrate streams from lignocellulose in a form suitable for efficient microbial conversion and downstream processing appropriate to the desired end use, making overall process development, along with selection of appropriate target molecules, crucial to the integrated biorefinery. Succinic acid (SA), a high-value target molecule, can be biologically produced from sugars and has the potential to serve as a platform chemical for various chemical and polymer applications. However, the feasibility of microbial SA production at industrially relevant productivities and yields from lignocellulosic biorefinery streams has not yet been reported. RESULTS: Actinobacillus succinogenes 130Z was immobilised in a custom continuous fermentation setup to produce SA on the xylose-enriched fraction of a non-detoxified, xylose-rich corn stover hydrolysate stream produced from deacetylation and dilute acid pretreatment. Effective biofilm attachment, which serves as a natural cell retention strategy to increase cell densities, productivities and resistance to toxicity, was accomplished by means of a novel agitator fitting. A maximum SA titre, yield and productivity of 39.6 g L(-1), 0.78 g g(-1) and 1.77 g L(-1) h(-1) were achieved, respectively. Steady states were obtained at dilution rates of 0.02, 0.03, 0.04, and 0.05 h(-1) and the stirred biofilm reactor was stable over prolonged periods of operation with a combined fermentation time of 1550 h. Furthermore, it was found that a gradual increase in the dilution rate was required to facilitate adaptation of the culture to the hydrolysate, suggesting a strong evolutionary response to the toxic compounds in the hydrolysate. Moreover, the two primary suspected fermentation inhibitors, furfural and HMF, were metabolised during fermentation with the concentration of each remaining at zero across all steady states. CONCLUSIONS: The results demonstrate that immobilised A. succinogenes has the potential for effective conversion of an industrially relevant, biomass-derived feed stream to succinic acid. Furthermore, due to the attractive yields, productivities and titres achieved in this study, the process has the potential to serve as a means for value-added chemical manufacturing in the integrated biorefinery.

A campus-community partnership for farmworkers' health: interventions for tomato workers in Tennessee.

BACKGROUND: Migrant farm workers are exposed to job hazards in Tennessee, which is among the top five tomato-producing states. OBJECTIVES: This project sought to cultivate and evaluate a partnership to marshal greater resources to address migrants' concerns and to better prepare future health professionals to address occupational issues. METHODS: In the spring of 2008, an interprofessional student-faculty team at a regional university catalyzed a partnership with a clinic for migrants and a national network caring for the itinerant underserved. RESULTS: Several community-based participatory research (CBPR) activities are underway. The partnership has resulted in the following projects: Use of the Rapid Entire Body Assessment (REBA) method to identify job tasks likely to be injurious, development and use of a health screening questionnaire to capture more information about occupational health, and continuing education seminars for providers and a case-based curriculum module for third-year medical students. CONCLUSIONS: Interprofessional service learning about migrant occupational health issues may have its greatest impact as participating students enter the regional workforce, caring for patients employed in slow-to-change agricultural operations.