Dietary protein and energy requirements of Venda village chickens

The objective of this study was to determine the dietary protein and apparent metabolisable energy (AME) requirements of local chickens. Freshly laid eggs of scavenging chickens collected in rural villages were hatched and randomly distributed to 27 floor pens, 10 chicks per pen. Chicks were fed 9 experimental diets that were combinations of three CP levels (140, 170 and 190 g kg−1 DM) and three AME levels (11.0, 11.7 and 12 MJ kg−1) during the starter phase (0–6 weeks) and combinations of three CP levels (120, 150 and 180 g kg−1 DM) and three ME levels (11.3, 12.0 and 12.4 MJ kg−1) during the grower phase (7–17) weeks. Significant differences within means on CP × AME interaction effect were observed in all parameters measured, except feed intake during starter period and dressing percentage (%) and breast yield of 17 weeks old chickens. The results of the present study indicated that during the starter and grower phases, unsexed chickens would require dietary combinations of 170 g CP kg−1 and 11.0 AME MJ kg−1 and 150 g CP kg−1 and 12 AME MJ kg−1 in their diets to optimise weight gain and FCR, and 150 g CP kg−1 and 11.3 MJ kg−1 to optimise ash content of muscles, protein content of the breast and fat content of the leg muscle. Supplementation of 27 g CP kg−1 feed to grower scavenging chickens would be enough to improve chicken production in the rural villages

Growth performance and digestive tract development of indigenous scavenging chickens under village management

The study was conducted on indigenous scavenging chickens under village management firstly, to evaluate the early development of the digestive tract to 28 days of age and secondly, to determine the growth performance of these chickens up to 20 weeks of age. One hundred and seventeen chicks, 13 chicks per age class (day 1, 4, 7, 10, 14, 17, 21, 24, 28) were randomly purchased from six rural villages in the Vhembe District, Venda, South Africa. The chickens were weighed and sacrificed for measurement of the different parts of its gastrointestinal tract. The liver and pancreas were also weighed. The relative weight of the storage organs and liver peaked at day 4 while that of the small intestine and duodenum peaked at day 10. The relative lengths of the small intestine and jejunum peaked at day 7, duodenum at day 10 and ileum at day 4. Four hundred and forty four (444) chicks from 13 households were recorded at two weekly intervals starting from day old until 20 weeks of age. The mean body weight obtained for males and females were 201.7 and 171.5 g at six weeks of age and 1048.1 and 658.6 g at 20 weeks of age, respectively. The indigenous chickens under village management were characterised by slow digestive tract development, poor growth performance and high mortalities. Further research needs to be conducted to determine the effect of early feed supplementation on the development of the digestive tract and the performance of indigenous chickens under village management

Paediatric cardiac anaesthesia in sickle cell disease: a case series

Sickle cell disease (SCD) is the most common inherited haematological disorder, producing a mutation of the haemoglobin molecule known as haemoglobin S (HbS). The presence of HbS in the erythrocyte makes it prone to sickling — a process that may lead to vaso-occlusive injury, haemolysis and a hypercoagulable state. Sickling is precipitated by dehydration, hypoxia, hypothermia, acidosis and low flow situations. Over time, multi-organ damage develops with significant morbidity and mortality. Paediatric patients with SCD and congenital heart defects may require anaesthesia for corrective cardiac surgery on cardiopulmonary bypass (CPB). During the perioperative period these high-risk patients may suffer significant complications when exposed to the conditions that favour erythrocyte sickling. This case series details experience of four paediatric patients with SCD who underwent corrective cardiac surgery at Red Cross War Memorial Children’s Hospital. The pathophysiology is discussed and the perioperative management of transfusion, cardiopulmonary bypass and temperature regulation is highlighted.Keywords: anaesthesia, cardiopulmonary bypass, sickle cell anaemia, sickle cell disease, transfusio

The use of phylogenetic reconstruction as a predictive tool to functionally identify raffinose family oligosaccharide (RFO) producing glycosyltransferases

Thesis (MScAgric)--Stellenbosch University, 2022.ENGLISH ABSTRACT: Carbohydrate active enzymes (CAZymes) are numerous and diverse enzymes that are involved with the transport, synthesis, and catalysis of carbohydrates. All known and predicted CAZymes are housed on the CAZy database (www.cazy.org). Two classes of CAZymes, the glycosyltransferases (GTs) and glycosyl hydrolases (GHs) are important classes in the biosynthesis of a group of galacto- oligosaccharides termed the raffinose family of oligosaccharides (RFOs). The RFOs are the most widespread D-galactose (Gal) containing oligosaccharides in higher plants where they present a number of vital natural functions including carbon transport and storage and amelioration of both abiotic and biotic stresses. Recently, they have also emerged as powerful prebiotic agents, as they provided usable carbon stimulating the growth of health beneficial gut microbes. Their biosynthesis occurs through a distinct series of enzymatic reactions that begin with the biosynthesis of galactinol (Gol) catalysed by the action of a galactinol synthase (GolS, GT8, EC 2.4.1.67). It is Gol that serves as the galactosyl donor toward the biosynthesis of raffinose (Raf) and stachyose (Sta). These reactions are catalysed by the GHs raffinose synthase (RafS, GH36, EC 2.4.1.82) and stachyose synthase (StaS, GH36, EC 2.4.1.67), respectively. Numerous entries into genome databases and the CAZy repository, which lack functional biochemical description are only putatively annotated according to sequence similarities to orthologous gene sequences. Here, the use of orthologous genes to putatively annotate proteins, specifically RFO synthesising enzymes, has led to inaccuracies in database records with regards to the functional enzyme annotations – with many RFO related CAZymes putatively annotated as being similar to GTs (involved in synthesis) and GHs (involved in hydrolysis). Consequently, functional characterisations of RafSs and StaSs are historically underrepresented in literature as they are difficult to identify – despite the extensive genome resource databases available for numerous plants models. The emerging repurposing of phylogenetic reconstructions has shown increased accuracy when annotating putative enzymes. Online resources such as SIFTER and PhyloGenes (https://sifter.berkeley.edu/, http://www.phylogenes.org/) have the ability to use phylogenetic trees as a means to accurately identify groupings of proteins which share functional identities. In this study, we sought to use a phylogenetic reconstruction as a predictive tool toward function, to identify RFO biosynthetic genes (RafS and StaS) from publicly available genome resource databases where their functional annotations are either putative or unclear. We focused largely to the newly established legume genome databases, using the known orthologues from Arabidopsis RafS (AtRS5, At5G40390) and StaS (AtRS4, At4G01970) in BLASTn and BLASTp searches, to identify candidate genes. We subsequently focused to key signatures in the amino acid sequences of the candidate genes, including a hallmark 80 amino acid signature which represents a potential functional discriminator between RafS and StaS proteins to carefully curate the candidate genes. We then generated Maximum Likelihood and Bayesian Inference trees, rooting them against Arabidopsis ATSIP2 (At3G56590), a known Raf hydrolysing alkaline α-galactosidase (α-Gal, EC 3.2.1.22.). Based on the outcomes of the trees, we selected two legume RafS candidates from barrel medic (Medicago truncatula) and chickpea (Cicer arietinum). The coding sequences of these genes were isolated, cloned into a bacterial expression vector and heterologously expressed in E. coli. Using crude protein extracts, we then sought to determine if they demonstrated the ability to produce Raf, when incubated in vitro in the presence of sucrose and galactinol. Using quantitative tandem mass spectrometry (LC-MS/MS), we were not able to identify a distinct Raf producing capacity for either gene candidate, nor was a recombinant protein produced when using the bacterial expression vector pSF-OXB20 (constitutive promoter). However, the candidate RafS gene from M. truncatula was then cloned into the pDEST17™ bacterial expression vector (arabinose inducible promoter) and we could then identify Raf synthesis capacity in crude protein extracts. This provided some evidence toward the validity of our phylogenetic reconstruction as this RafS gene candidate has an unclear functional annotation in the genome resource databases for M. truncatula.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaar.Master

Rare event sampling with stochastic growth algorithms

We discuss uniform sampling algorithms that are based on stochastic growth methods, using sampling of extreme configurations of polymers in simple lattice models as a motivation. We shall show how a series of clever enhancements to a fifty-odd year old algorithm, the Rosenbluth method, led to a cutting-edge algorithm capable of uniform sampling of equilibrium statistical mechanical systems of polymers in situations where competing algorithms failed to perform well. Examples range from collapsed homo-polymers near sticky surfaces to models of protein folding.Comment: First International Conference on Numerical Physic

At the crossroads of survival and death : the reactive oxygen species-ethylene-sugar triad and the unfolded protein response

Upon stress, a trade-off between plant growth and defense responses defines the capacity for survival. Stress can result in accumulation of misfolded proteins in the endoplasmic reticulum (ER) and other organelles. To cope with these proteotoxic effects, plants rely on the unfolded protein response (UPR). The involvement of reactive oxygen species (ROS), ethylene (ETH), and sugars, as well as their crosstalk, in general stress responses is well established, yet their role in UPR deserves further scrutiny. Here, a synopsis of current evidence for ROS-ETH-sugar crosstalk in UPR is discussed. We propose that this triad acts as a major signaling hub at the crossroads of survival and death, integrating information from ER, chloroplasts, and mitochondria, thereby facilitating a coordinated stress response

Water and salt balances of two shallow groundwater cropping systems using subjective and objective irrigation scheduling

Evidence suggests that, in general, subjective rather than objective irrigation  scheduling decisions are adopted by farmers. Irrigators have ‘calibrated’ themselves with years of experience to irrigate subjectively according to perceived crop water requirements. This study aimed to determine the associated benefits of objective versus subjective scheduling of two shallow groundwater cropping systems. Weekly measurements included rainfall and irrigation amounts, soil water content, groundwater table depth, artificial drainage volumes, and electrical conductivity of irrigation water, groundwater and drainage water.  Simulations of evaporation and transpiration were done with the SWAMP model. Based on soil water and salinity status, matric and osmotic stress during the four cropping seasons is considered unlikely. When rainfall-plusirrigation was compared to evapotranspiration, objective scheduling resulted in an under-supply of 15%, and rainfall and shallow groundwater served as supplementary water sources. Subjective scheduling did not use rainfall efficiently as a source of water and resulted in an over-supply of 10%.  Approximately 50% less salt was leached with objective compared to subjective irrigation scheduling. Under shallow groundwater conditions, irrigating subjectively according to crop water requirement results in excessive irrigation, salt addition and leaching compared to objective scheduling. Farmers can address some of the environmental problems  associated with irrigation by adopting objective scheduling and reducing the leaching fraction (< 0.15) of shallow groundwater cropping  systems.Keywords: evapotranspiration, leaching, salinity, water conservation, water degradatio

Chest pain : the importance of serial ECGs

A 44-year-old man, previously well, presented to the emergency department with severe hypertension and a 4-hour history of typical angina-like chest pain with associated diaphoresis. He had dyslipidemia, a 5-pack-year history of smoking, and, likely, undiagnosed hypertension.https://www.ccjm.orghj2022Cardiolog

Preventing Anorexia in Adolescents Through Empowerment and Education (PAATTEE)

Preventing Anorexia in Adolescents Through Empowerment and Education (PAATEE) is a primary preventive program that aims to reduce the risk of adolescent females from developing anorexia nervosa (AN) by using an evidence-based, multilevel approach. The program intends to reduce the risk of AN by influencing the social environment surrounding body image, increasing self-efficacy in program participants, providing education about eating disorders, and promoting intuitive eating practices

Deception in network defences using unpredictability

In this article, we propose a novel method that aims to improve upon existing moving-target defences by making them unpredictably reactive using probabilistic decision-making. We postulate that unpredictability can improve network defences in two key capacities: (1) by re-configuring the network in direct response to detected threats, tailored to the current threat and a security posture, and (2) by deceiving adversaries using pseudo-random decision-making (selected from a set of acceptable set of responses), potentially leading to adversary delay and failure. Decisions are performed automatically, based on reported events (e.g., Intrusion Detection System (IDS) alerts), security posture, mission processes, and states of assets. Using this codified form of situational awareness, our system can respond differently to threats each time attacker activity is observed, acting as a barrier to further attacker activities. We demonstrate feasibility with both anomaly-and misuse-based detection alerts, for a historical dataset (playback), and a real-time network simulation where asset-to-mission mappings are known. Our findings suggest that unpredictability yields promise as a new approach to deception in laboratory settings. Further research will be necessary to explore unpredictability in production environments