39 research outputs found
Ante‐natal and post‐natal influences on neonatal immunity, growth and puberty of calves—a review
Calf immunity, growth and puberty are important factors affecting heifer productivity. The first four weeks of age are critical for reducing calf morbidity and mortality. It is well documented that colostrum is paramount to neonatal nutrition and passive immunity, however, adap-tation to extra‐uterine life starts early during embryonic development. Therefore, successful calf rearing strategies are underpinned by adequate maternal nutrition during gestation, and good co-lostrum management. A deeper understanding of these interactions paves the way for developing strategies to improve immune responses to environmental pathogens, optimal growth and timely attainment of puberty in calves. The literature reviewed here shows that there are opportunities to enhance the future performance of cattle paying attention to the interaction of nutrition and immunity at each developmental stage. Therefore, the objective of this review is to give the reader an overview of interactions between immunity, growth and puberty in dairy calves and highlight how these influence future performances
Improvement of Energy Efficiency for Wastewater Treatment
Wastewater treatment requires the elimination of pathogens and reduction of organic matter in the treated sludge to acceptable levels. One process used to achieve this is Autothermal Thermophylic Aerobic Digestion (ATAD), which relies on promoting non-pathogenic thermophilic bacteria to digest organic matter and kill pathogens through metabolic heat generation. This process requires continuous aeration that may be energy consuming, and the final aim of the study is to identify how the process design can minimize the energy input per mass of treated sludge. Appropriate modeling of the reactor process is an essential ingredient, so we explore properties of an existing model and propose a simplified alternative model
Some optimised schemes for 1D Korteweg-de-Vries equation
Two new explicit finite difference schemes for the solution of the one-dimensional Korteweg-de-Vries equation are proposed. This equation describes the character of a wave generated by an incompressible fluid. We analyse the spectral properties of our schemes against two existing schemes proposed by Zabusky and Kruskal (1965) and Wang et al. (2008). An optimisation technique based on minimisation of the dispersion error is implemented to compute the optimal value of the spatial step size at a given value of the temporal step size and this is validated by some numerical experiments. The performance of the four methods are compared in regard to dispersive and dissipative errors and their ability to conserve mass, momentum and energy by using two numerical experiments which involve solitons.South African DST/NRF SARChI Chair on Mathematical Models and Methods in Bioengineering and Biosciences (M3B2) of the University of Pretoria and the National Research Foundation of South Africa [95864, 93476].http://www.inderscience.com/jhome.php?jcode=PCFD2017-12-21hj2017Mathematics and Applied Mathematic
The ovine hepatic mitochondrial proteome: understanding seasonal weight loss tolerance in two distinct breeds
Research ArticleSeasonal weight loss (SWL) is a primary constraint for farmers in the Mediterranean and
tropics. One cost-effective solution to SWL is utilizing breeds like the Damara sheep that
have adapted to deal with nutritional stress. Previous studies concluded that one of the
adaptation mechanisms of SWL is a specialized fatty acid metabolism. Accordingly,
hepatic-mitochondrial proteomes were compared across two different breeds (24 sheep
total, Merino, n = 12 and Damara, n = 12) and two different diets (restricted vs unrestricted
diet, 6 per breed, per diet, 24 total). Mitochondrial-proteins were isolated and relatively quantified
using Blue native PAGE / 2D-electrophoresis and then analyzed via mass spectrometry.
The tool ReviGO summarized the proteomes’ gene-ontology terms. A total of 50
proteins were identified with 7 changing significantly in abundance (ANOVA p-value<0.05).
Specific abundance patterns of corticosteroid and inflammatory response-associated proteins
such as annexin and glutamate dehydrogenase suggests that the Damara has an
unusual inflammation response when subjected to SWL in addition to its unique metabolism.
All significant proteins warrant further study; Annexin in particular shows promise as a
potentially useful biomarkerinfo:eu-repo/semantics/publishedVersio
A model for reactive porous transport during re-wetting of hardened concrete
A mathematical model is developed that captures the transport of liquid water
in hardened concrete, as well as the chemical reactions that occur between the
imbibed water and the residual calcium silicate compounds residing in the
porous concrete matrix. The main hypothesis in this model is that the reaction
product -- calcium silicate hydrate gel -- clogs the pores within the concrete
thereby hindering water transport. Numerical simulations are employed to
determine the sensitivity of the model solution to changes in various physical
parameters, and compare to experimental results available in the literature.Comment: 30 page
Influence of energy balance on the antimicrobial peptides S100A8 and S100A9 in the endometrium of the postpartum dairy cow
Uterine inflammation occurs after calving in association with extensive endometrial remodelling and bacterial contamination. If the inflammation persists, it leads to reduced fertility. Chronic endometritis is highly prevalent in high-yielding cows that experience negative energy balance (NEB) in early lactation. This study investigated the effect of NEB on the antimicrobial peptides S100A8 and S100A9 in involuting uteri collected 2 weeks post partum. Holstein-Friesian cows (six per treatment) were randomly allocated to two interventions designed to produce mild or severe NEB (MNEB and SNEB) status. Endometrial samples were examined histologically, and the presence of neutrophils, macrophages, lymphocytes and natural killer cells was confirmed using haematoxylin and eosin and immunostaining. SNEB cows had greater signs of uterine inflammation. Samples of previously gravid uterine horn were used to localise S100A8 and S100A9 by immunohistochemistry. Both S100 proteins were present in bovine endometrium with strong staining in epithelial and stromal cells and in infiltrated leucocytes. Immunostaining was significantly higher in SNEB cows along with increased numbers of segmented neutrophils. These results suggest that the metabolic changes of a post-partum cow suffering from NEB delay uterine involution and promote a chronic state of inflammation. We show that upregulation of S100A8 and S100A9 is clearly a key component of the early endometrial response to uterine infection. Further studies are warranted to link the extent of this response after calving to the likelihood of cows developing endometritis and to their subsequent fertility
Feasibility and economic costs of syphilis self-testing to expand test uptake among gay, bisexual and transgender men: results from a randomised controlled trial in Zimbabwe
Background
Access to syphilis testing and treatment is frequently limited for men who have sex with men (MSM). A two-armed randomised controlled trial compared feasibility and costs of facility-based syphilis testing with self-testing among MSM in Zimbabwe.
Methods
This randomised controlled trial was conducted in Harare, with participants randomised 1:1. Syphilis self-testing was offered in community-based settings. The primary outcome was the relative proportion of individuals taking up testing. Total incremental economic provider and user costs, and cost per client tested, diagnosed and treated were assessed using ingredients-based costing in 2020 US859 and US30 and US107 and US215 and US9.
Conclusion
Syphilis self-testing may increase test uptake among MSM in Zimbabwe. However, some barriers limit uptake including lack of self-testing and poor service access. Bringing syphilis testing services to communities, simplifying service delivery and increasing self-testing access through community-based organisations are useful strategies to promote health-seeking behaviours among MSM