Characteristics of impala (Aepyceros melampus) skeletal muscles

The aim of this study was to determine citrate synthase (CS), phosphofructokinase (PFK) activities and myosin heavy chain (MHC) isoform contents in four muscle groups (semimembranosus (S), deltoideus (D), longissimus lumborum (LL), and psoas major (PM)) of impala (n=6). All four muscle groups expressed predominantly MHC IIa (means of 55±22-93±12%). MHC IIx was only expressed in D. In D, positive correlations were found between MHC I and age (r=0.93; P<0.05) and the weight of the animals (r=0.94; P<0.01). PFK (means of 175±179-374±181), CS (means of 100±23-126±38 μmol/min/gdw) and MHC content indicated that energy provision in the impala is produced to a large extent via oxidative pathways and fibre types vary with animal characteristics.     

Contamination of freshly harvested Bambara groundnut (Vigna subterranea) seed from Mpumalanga,South Africa,with mycotoxigenic fungi

Freshly harvested Bambara groundnut (BGN) is occasionally consumed raw and can potentially become infected with mycotoxingenic field fungi. In this study, BGN samples were obtained from 12 farms in three districts of Mpumalanga in South Africa. Eight pooled samples were screened for multi-mycotoxin contamination using Ultra Performance Liquid-Chromatography tandem mass spectrometry (UPLC-MS/MS). To identify mycoflora, 12 samples were screened using conventional and molecular methods. Selected potential mycotoxin producing isolates were screened for mycotoxins using UPLC-MS/MS. No mycotoxins were detected on the freshly harvested BGN samples, but they were infected with various mycotoxin producing fungal species namely Aspergillus flavus (50%), Penicillium citrinum (25%), Penicillium oxalicum (17%), Penicillium citreoviridin (0.8%), and Fusarium verticillioides (0.8%). Following screening of selected fungal cultures, aflatoxin B₁ (0.4, 0.45 and 0.4 ppm) and fumonisin B₁ (0.7 ppm) were detected from A. flavus and F. verticillioides, respectively. Identification of mycotoxigenic fungi on freshly harvested BGN presents a potential health risk.     

Management of retinal vein occlusion

Retinal vein occlusion is a common cause of visual loss. The clinical features, pathogenesis, aetiology and management of this condition are presented and discussed. It is an advantage to involve both the physician and the ophthalmologist in the management of the condition.     

Multiple-Shockley unfaulting of single-layer faulted defects

The general principles laid down by Swart & Kritzinger (1974a) in a paper dealing with the unfaulting of Frank dislocation loops by the simultaneous action of two shearing Shockley dislocations are applied to explain the structure and electron diffraction contrast behaviour of certain complex single-layer dislocation configurations observed in quenched aluminium and dilute Al-Mg alloys. In these cases the simultaneous operation of three Shockley dislocations is employed. It is also demonstrated that adequate stresses, such as those encountered during annealing at temperatures ～150°C, serve to transform butterfly hexagons to normal hexagonal prismatic dislocation loops, confirming the expectation that the butterfly defects are in a metastable state.     

The effects of sex and region on the carcass yield and m longissimus lumborum proximate composition of impala

Physical morphological measurements and m longissimus lumborum proximate chemical composition of impala (Aepyceros melampus) and the effects of age, sex and region on these parameters were investigated. Impala were randomly sampled from Mara (n = 40, 24 males, 16 females), situated in the Arid Sweet Bushveld region, and Musina (n = 28, 15 males, 13 females), situated in the Mopane Bushveld region in the Limpopo Province of South Africa. The live weights of the Mara (50.23 ± 9.32 kg) animals were higher (p < 0.05) than those of the Musina animals (44.25 ± 10.81 kg). The male animals from both regions were significantly heavier than the females (p < 0.05), particularly for the older animals (～5 kg for 30‐month‐old animals and ～10 kg for 42‐month‐old animals); however, the dressing percentages between the sexes did not differ. The Mara female group (～62%) had significantly (p < 0.05) higher mean dressing percentages than the Musina females (～58%). The mean proportions of external and internal offal were relatively higher in the Musina animals. No significant differences in the dressing percentages between the five age groups were found. Carcass measurements increased linearly with age. Age showed no effect on the m longissimus lumborum chemical carcass composition. Female animals (～19.4 g kg^?1) had higher (p < 0.05) lipid contents for both regions than the males (～14.0 g kg^?1) but the sex of the animal had no effect on the remaining chemical carcass composition parameters. The crude protein content of the Musina animals (248.8 ± 10.44 g kg^?1) was higher (p < 0.05) than for the Mara animals (238.0 ± 8.404 g kg^?1). The mean ash content of the impala m longissimus lumborum was ～12 g kg^?1. The results indicated that age effects are caused by the increases in size brought about by the growth of the animal and by the development of sexual dimorphism. Age, however, had no effect on the m longissimus lumborum proximate chemical composition. Regional differences were also shown for both the physical parameters as well as for the proximate chemical composition of the muscle. Similarly, females also differed from males for the parameters measured. These factors will have to be taken into consideration by the meat trade when purchasing, processing and marketing impala game meat. Copyright © 2004 Society of Chemical Industry     

The effects of region and gender on the fatty acid, amino acid, mineral, myoglobin and collagen contents of impala (Aepyceros melampus) meat

The effects of sex and region on the fatty acid profile, mineral contents, collagen and myoglobin contents of impala (Aepyceros melampus) meat were investigated. The study was conducted in the Limpopo Province of South Africa where impala were sampled from two separate regions. Female animals at Mara showed higher levels (P<0.05) of saturated (SFA), and mono-unsaturated fatty acids (MUFA) in their tissues than the male animals. The females at Musina also showed a tendency (P<0.10) towards higher levels of SFA and MUFA than the males. Males from both regions showed higher levels (P<0.05) of poly-unsaturated fat than the females. Myristic, palmitic and stearic acid made up the greatest proportion of the SFA component for the males and females from both regions. Oleic acid represented the largest component of the MUFA, with the Mara animals showing higher levels than the Musina animals. α-linoleic, γ-linoleic, and linolenic acid made up the largest proportions of the poly-unsaturated component for both of the regions. Neither region nor sex had any influence on the amino acid content of the meat. The male animals at Mara had lower (P<0.05) myoglobin contents than the females for that region. Region had no effect on the myoglobin content of the meat. No significant sex or regional differences were found in the hydroxyproline and collagen contents of the meat (P>0.05). Regional differences (P<0.05) were found in the amounts of phosphorous and calcium present in the meat. The male animals at Mara were found to have higher levels of zinc than the females.     

Modeling buffer utilization in cell-based networks

Variable bit rate traffic is characteristically bursty and the arrivals are highly correlated. New network technology carries such traffic in cell-based networks where the service is a discrete time, deterministic process with the service rate determined by bandwidth negotiated by the user. Managing such networks is hard, and predicting cell loss at a station with limited buffer capacity K is essential to enable the user to negotiate his quality of service requirements. We present an analysis to determine the queue length distribution and the loss probability in such circumstances. For our analysis, we use an m-phase Markov Modulated Bernoulli Process with binomial distributed batch arrivals and deterministic service and limited capacity K, i.e. a MMBP^[X]_(m)/D/1 − K queuing system. We show that the system can be analyzed using the so-called unfinished work approach. The validity of our evaluation technique is illustrated by comparing our analytical results against those obtained from an event-driven siimulation of the same system.