Search

The only previous study on the macrobiota of South African boulder shores showed this assemblage to be more diverse than on nearby rocky platforms, but the drivers of that difference remain unresolved. We recorded water and air temperatures under intertidal boulders and on adjacent exposed rocky platforms, at both the upper- and lower-shore level, at Kommetjie, South Africa, over 2-week tidal cycles, repeating this during summer and winter. The macrobiota in each location was also sampled during diurnal low tides. The most-extreme temperatures, and greatest ranges, occurred during summer on upper-shore open rock (13.9–37.7 °C, range difference of 23.8 °C), while under upper-shore boulders the maximum temperature was lower at 28.9 °C and the range spanned only 15.5 °C. In winter, maximum temperatures and ranges were lower at all locations. Maximum temperatures did not coincide with spring tides, but occurred several days later, when low tides happened during the heat of the day. Closer analysis of daily fluctuations revealed influence of weather on temperatures attained and showed that durations of elevated temperatures were much shorter in the lower shore. The upper shore exhibited low biodiversity, supporting only 9 species, with 8 found only under boulders during diurnal low tide; the lower shore was more diverse, with 11 species on open rock and 29 under boulders. Biomass and abundance were also higher under boulders at both levels, especially on the upper shore. More-benign under-boulder conditions thus facilitate more abundant and diverse biota sheltering there than occurs on adjacent exposed rocks, particularly on the upper shore. [ABSTRACT FROM AUTHOR]

The next era of ground-based Cherenkov telescope development will see a great increase in both quantity and quality of γ-ray morphological data. This initiated the development of a spatiotemporal leptonic transport code to model pulsar wind nebulae. We present results from this code that predicts the evolution of the leptonic particle spectrum and radiation at different radii in a spherically symmetric source. We simultaneously fit the overall broad-band spectral energy distribution, the surface brightness profile, and the X-ray photon index versus radius for PWN 3C 58, PWN G21.5 − 0.9, and PWN G0.9 + 0.1. Such concurrent fitting of disparate data sets is non-trivial and we thus investigate the utility of different goodness-of-fit statistics, specifically the traditional χ2 test statistic and a newly developed scaled-flux-normalized test statistic to obtain best-fitting parameters. We find reasonable fits to the spatial and spectral data of all three sources, but note some remaining degeneracies that will have to be broken by future observations. [ABSTRACT FROM AUTHOR]

Introduction: Gastro-oesophageal Reflux Disease (GORD) is a common disorder associated with significant impairment in quality of life. The effect of Helicobacter pylori (H pylori) eradication on GORD symptoms is not clear. Our aim was to determine whether eradication of H pylori is associated with decreased symptom response to GORD treatment. Methods: We recruited 45 consecutive patients presenting to our Tygerberg Hospital gastroenterology department with reflux symptoms and a GerdQ symptom score of 8 or more. Oesophagogastroduodenoscopy with gastric biopsies and a rapid urease test for H pylori was done. All patients were started on omeprazole 20 mg daily. After 4 weeks a second GerdQ questionnaire was administered and patients with H pylori were started on eradication therapy. After 6 weeks a third GerdQ questionnaire was administered. Four categories of outcome were created based on Antral and Corpus Helicobacter pylori result, whether positive or negative or both and associated risk factors were assessed using binary logistic regression. Results with p-values<0.05 were statistically significant. Results: Of the 45 patients evaluated, 73% (n=33) were H pylori positive and 27% (n=12) were negative. There were no statistically significant differences between the two groups (H. Pylori positive and H. Pylori negative) in gender distribution, smoking status, body mass index, waist-hip ratio or haemoglobin A1C levels. All except two patients were of mixed race. The H pylori negative group had a mean 1stGerdQ score of 12.41 compared to 11.45 (p-value 0.37) for the H pylori positive group. There were no statistical difference in the 2nd score (4.08 vs 4.47, p-value 0.316) or the 3rdGORDQ (3.67 vs 3.19, p-value 0.926) comparing the H pylori negative group and H pylori positive groups. Conclusions: Our results demonstrated that eradication of H pylori had no influence on response to proton pump inhibitors among GORD patients. Clinicians should eradicate H pylori if it is found in GORD patients and may prevent future H pylori complications. [ABSTRACT FROM AUTHOR]

We present results from a leptonic emission code that models the spectral energy distribution of a pulsar wind nebula by solving a Fokker–Planck-type transport equation and calculating inverse Compton and synchrotron emissivities. We have created this time-dependent, multizone model to investigate changes in the particle spectrum as they traverse the pulsar wind nebula, by considering a time and spatially dependent B-field, spatially dependent bulk particle speed implying convection and adiabatic losses, diffusion, as well as radiative losses. Our code predicts the radiation spectrum at different positions in the nebula, yielding the surface brightness versus radius and the nebular size as function of energy. We compare our new model against more basic models using the observed spectrum of pulsar wind nebula G0.9+0.1, incorporating data from H.E.S.S. as well as radio and X-ray experiments. We show that simultaneously fitting the spectral energy distribution and the energy-dependent source size leads to more stringent constraints on several model parameters. [ABSTRACT FROM AUTHOR]

During July 2009 and 2010 surveys of snail-borne larval trematodes of the Okavango Delta floodplains and lagoons were undertaken.Cercaria mohemboensewere shed byPila occidentalis(Mousson, 1887) andCercaria dubaensisandCercaria indistinctuswere shed byBiomphalaria pfeifferi(Krauss, 1848), respectively. Morphological descriptions of these fork-tailed cercariae are given, with suggestions on the possible life cycles of these parasites. [ABSTRACT FROM AUTHOR]

The aim of the study was to evaluate the nutritional status of scavenging chickens by assessing the composition of their crop contents. The study was conducted on 288 free-ranging indigenous chickens from six adjacent rural villages in Venda region of South Africa over three seasons (autumn, winter and spring). The chickens consumed grains, kitchen waste, seeds from the environment, plant materials, worms and insects, and some undistinguishable materials. Household waste accounted for 78.6%, 91.1% and 75.8% and materials of animal origin, including insects and worms, accounted for 7.4%, 10.4% and 16% of the crop content in autumn, winter and spring, respectively. Grains and kitchen waste consumption and macro- and micro-nutrient concentrations varied with season. The crude protein (CP) level of the crop contents of adult chickens in all seasons and the calcium and phosphorus levels in winter corresponded with the requirements of poultry for maintenance and growth, but not egg production. Supplementation of CP to young birds in all seasons and calcium and phosphorus in autumn and spring might be necessary to improve their growth. Concentrations of copper, manganese, zinc and cobalt were above the requirements of poultry, but below their maximum tolerance levels (MTL). Iron concentrations ranged from 2907 mg/kg DM to 6424 mg/kg DM, which are well above MTL, suggesting potential detrimental effects on the birds if the iron in the crop contents is bioavailable. Aluminium concentrations ranged from 2256 mg/kg DM to 4192 mg/kg DM, though aluminium is considered non-toxic. It was concluded that the birds would not suffer from micro-mineral deficiencies, and that a risk of toxicity would depend on the bioavailability of the consumed element. [ABSTRACT FROM AUTHOR]

The cellular uptake by human neutrophils and the intraphagocytic biological activity of the new macrolide antimicrobial agent dirithromycin (0.01-2 mg/L) compared with erythromycin was investigated in vitro. Staphylococcus aureus, Listeria monocytogenes and Legionella pneumophila were used as the test intracellular microbial pathogens. After coincubation (45 min at 37 degrees C) of neutrophils with a fixed concentration of 2 mg/L of each antibiotic the respective intracellular/extracellular ratios for erythromycin and dirithromycin were 6.1 +/- 2.5 and 10.6 +/- 2 respectively (P < 0.005). Using a combination of techniques (colony counting, radiometry and fluorescence microscopy) both erythromycin and dirithromycin at concentrations of 0.01 and 0.5 mg/L and higher, respectively, were found to possess dose-related intraphagocytic bacteristatic activity for each of the test microbial pathogens. The effects of dirithromycin and erythromycin (1-20 mg/L) on neutrophil chemotaxis and generation of reactive oxidants by these cells were also investigated in vitro. Both antimicrobial agents caused a dose-related stimulation of neutrophil migration which was associated with inhibition of leucoattractant-activated generation of superoxide and activity of the myeloperoxidase/H2O2/halide system. However, superoxide generation by neutrophils activited with opsonized zymosan or phorbol myristate acetate was unaffected by the macrolides. These findings demonstrate that dirithromycin accumulates in human neutrophils, is biologically active intracellularly and modulates leucoattractant-activated superoxide generation and chemotaxis. [ABSTRACT FROM AUTHOR]

The effects of erythromycin on neutrophil random migration and motility to the leucoattractant endotoxin-activated serum (EAS), post-phagocytic hexosemonophosphate shunt activity (HMS), myeloperoxidase (MPO)-mediated iodination of ingested and lymphocyte transformation to the mitogens phytohaemagglutinin (PHA) and concanavalin A (Con A) have been investigated and . For studies erythromycin was investigated as the base compound and as the stearate and succinate forms. Erythromycin stearate was used for studies in normal adult volunteers. Erythromycin but not caused significant stimulation of neutrophil motility and random migration at concentrations of 10 M -5 × 10 M. These concentrations caused inhibition of MPO-mediated iodination. Slight but insignificant stimulation of lymphocyte-transformation to both mitogens following ingestion of erythromycin was observed. The migration-stimulatory effects of erythromycin were potentiated by ascorbate and thiamine and by thiamine . Using the horse-radish peroxidase (HRP)/HO/sodium iodide system it was demonstrated that the enhancing effect of erythromycin on neutrophil motility and lymphocyte transformation was due to the anti-oxidant activity of the anti biotic. Exposure to the HRP/HO/iodide system had no adverse effects on the antimicrobial activity of erythromycin. [ABSTRACT FROM PUBLISHER]

The effects of erythromycin stearate over a concentration range of 10–10 on neutrophil functions were investigated. It was found that erythromycin at concentrations of 10–10 caused detectable stimulation of chemotaxis to autologous endotoxin-activated serum and inhibition of neutrophil post-phagocytic myelperoxidase mediated protein iodination at concentrations of >5×10. No effects on phagocytosis or post-phagocytic hexose monophosphate shunt activity were observed. studies before and after the ingestion of therapeutic doses of erythromycin by six individuals showed no change in neutrophil functions and levels of serum immunoglobulins IgG, IgA and IgM, total haemolytic complement and serum levels of the complement components C3 and C4. However ingestion of erythromycin was associated with increased lymphocyte transformation in five individuals. [ABSTRACT FROM PUBLISHER]

Heat processing is an effective way of reducing antinutritional factors (ANFs) in legumes, but requires expensive facilities and equipment. Accurate control of temperature is critical to avoid under- or overheating. Therefore, heat treatment of soybeans is not a viable option for the average small-scale farmer in remote areas. Germination and other traditional methods, namely soaking and dehulling, were evaluated as alternative processing methods for soybeans. The effect of the processing treatment on the level of different ANFs, nutritional composition and in vitro protein digestibility (IVPD) of soybean seeds was determined. Soybeans were soaked for 24 hours and allowed to germinate for one to six days. Soaked soybeans were manually dehulled. Changes within seeds were noted for nutritional and ANFs during germination. Crude protein and fat content increased with increasing number of days germinated, but germination caused a decrease in starch content. Dehulling also increased the crude protein and fat content of the seeds. All treatments caused a significant decrease in condensed tannins of the soybeans. Trypsin inhibitor levels were numerically lower after germinating, soaking and dehulling of seeds, but not significantly so. There were no changes in IVPD after treatment of the soybeans. It was concluded that germination for a period of three days effectively improved the nutritional value of soybeans and can be considered an alternative treatment of soybeans for the small-scale farmer where heat treatment is impractical or impossible. [ABSTRACT FROM AUTHOR]

The article reflects on the eradication of Helicobacter pylori (H.Pylori). It discusses the factors responsible for affecting the treatment for this disease which include non-ulcer dyspepsia, smoking, and obesity. It also describes urease breath test for the detection of H.Pylori infection in patient.