Research article about dinosaurs published in the prestigious journal, Nature

The Department of Paraclinical Sciences of the Faculty of Veterinary Science is not only expanding its horizons, it is also digging deeper into the past. Dr Fritz Huchzermeyer, an extraordinary lecturer in the Department, was a co-author of an article that was recently published in the prestigious journal, Nature. The work was done in collaboration with paleontologists in China. This publication reported the preservation of ovarian follicles in Mesozoic birds from China and the early evolution of avian reproductive behaviour. Crocodilians and birds are closely related to dinosaurs and are, therefore, ideal models to explain the reproductive behaviour of these extinct animals.Originally published as HTML file, converted to PDF with Adobe Acrobat 9 Pro Version 9.0.0.ab2013ab201

Investigation of stillbirths, perinatal mortality and weakness in beef calves with low-selenium whole blood concentrations

In this on-farm investigation, we report on stillbirths, weakness and perinatal mortality seen in calves on a commercial beef farm in the Roossenekal area, Mpumalanga province, South Africa. Post-mortem examination of these calves and histopathological examination of organ and tissue samples did not indicate an infectious aetiology. Affected calves had marginal to deficient whole blood selenium concentrations. Whole blood samples collected from adult cattle on this farm and five neighbouring farms were deficient in selenium. The potential contributions of other minerals to the symptoms seen are a subject of ongoing investigation, but selenium deficiency was marked in this herd and required urgent correction. Methods to correct the deficiency included the use of injectable products, and an oral selenium supplement chelated to methionine. Selenium availability to plants is primarily determined by the selenium content of the parent bedrock, the presence of other minerals and the pH of the soil. The apparent sudden onset of this problem implicates a soil factor as being responsible for reducing selenium’s bioavailability in this area. Selenium deficiency can have a significant impact on human health. HIV and/or AIDS, various forms of cancer and several specific clinical syndromes are associated with selenium deficiency in humans, and the impact on human health in this area also requires further investigation.http://www.jsava.co.zaam2016Paraclinical Science

In ovo manipulation of Nile crocodile embryos: egg windowing and potential dental research applications

Crocodilians exhibit continuous tooth replacement (i.e., polyphyodonty) and have been identified as suitable models for tooth regeneration research due to the similarity in dental cavity and tooth anatomy between these creatures and humans. Various studies reporting in ovo bird embryo manipulation exist, but such reports for reptiles are virtually non-existent. Egg windowing enables direct access to oviparous vertebrate embryos and is therefore an important component of in ovo embryo manipulation experiments. The aim of the present study was to window Nile crocodile, Crocodylus niloticus eggs and assess the potential of direct manipulations, targeting the pharyngeal region where the maxilla and mandible originates. Crocodylus niloticus eggs were successfully windowed, and a limited number of individuals survived the entire gestation period. The 1st trimester of gestation was the most sensitive, and 96.78% of the mortalities occurred within this period. Our data indicate the suitable window for embryo manipulation targeting the mandibular arch and maxillary process, without a risk of damaging the chorioallantoic membrane (CAM) (which may be fatal), was between day six and eight after laying for embryos incubated at 31°C. This data will be of use for future embryo-based experiments related to jaw and tooth development in crocodiles as well as human tooth regeneration research.http://www.ijdb.ehu.es/webhj2022Paraclinical Science

Serological evidence of Q fever in cattle in Malawi

The serological prevalence of Coxiella burnetii in cattle in Malawi is unknown. Serum samples from 200 Malawian zebu cattle were tested for C. burnetii antibodies using the complement fixation test. The percentage of positive and suspicious titres was 1,5 % and 5 % respectively.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

The effect of acid drinking water on rumen protozoa in the blesbok (Damaliscus dorcas phillipsi)

Rumen contents were collected from ten adult female blesbok, five from a mine area with only acid drinking water available and five from a control group consuming normal, non-polluted drinking water. The mean concentration of total protozoa in the normal water group was almost double that in the acid drinking water group, 24.9 x 103 versus 14.7 x 103 . Percent of Entodinium was higher and Diplodinium lower in those animals drinking the acid water. The number of different protozoa species present in animals from both locations was fairly similar. Diplodinium bubalidis, Ostracodinium gracile and Diplodinium consors were present in the highest percentage in the normal water group, 18.8, 18.4 and 17.7 %, respectively. The same three species, plus Entodinium dubardi, were also highest in the acid water group, O. gracile, 21.3 %; D. consors, 12.6 %; E. dubardi, 11.4 % and D. bubalidis, 10.3 %. Seventeen species of protozoa found in this study were a new host record for the blesbok, bringing the total number of species reported from the blesbok to 29.http://www.mapress.com/zootaxahb2016Anatomy and PhysiologyParaclinical Science

Evaluation of the genotoxic potential of water impacted by acid mine drainage from a coal mine in Mpumalanga, South Africa, using the Ames test and Comet assay

Several potential genotoxins found in water samples arise from anthropogenic activities. Acid mine effluent resulting from coal mining poses serious environment concerns all over the world. The use of toxicity tests to evaluate the quality of streams add value by providing site-specific toxicological data. Treatment systems such as the use of natural wetlands (passive) or conventional physical and chemical pH-neutralised processes (active) are employed mainly to meet certain water quality guidelines. Nonetheless, potential genotoxins or residues remain which influence the quality of discharged effluents. The objective of this study was to evaluate the genotoxic potential of acid mine drainage (AMD) released into a natural stream following treatment by passive and active methods. This study aimed to identify the extent of AMD mutagenicity and genotoxicity to African Vero monkey kidney cell line and a fish gill cell line (RTgill-W1) using two assays, the Ames test, and the comet assay, as a rapid and effective screening tool. The Ames test performed without metabolic activation using Salmonella typhimurium TA98 and TA100 strains showed no indication of mutagenicity in the water samples tested. Differing results were however obtained for the comet assay using the African Vero monkey kidney cell line and a fish gill cell line (RTgill-W1), which revealed DNA fragmentation and variations in morphologies indicative of genotoxicity in the water samples following the two treatment processes. A significant reduction in DNA damage was observed in water samples following active treatment of the AMD, evidenced by reduced damage frequency and a lowered comet score. This bioassay confirms the urgency of integrating high-throughput screening in aquatic toxicity assessment at genetic levels, giving further evidence that in-vitro bioassays can be incorporated for use in short-term genotoxicity assays. The result suggests that the comet assay proved sensitive at detecting genotoxicity, supporting the integration of this into environmental monitoring frameworks targeted at AMD-contaminated sites

Serological reactions to Leptospira species in buffalo (Syncerus caffer) from the Kruger National Park

Four hundred and six serum samples from buffalo (Syncerus caffer) were tested for leptospirosis, using the microscopic agglutination test. Seven buffaloes (1,7%) reacted positive and 27 (6,6%) inconclusive. Reactions against L. tarassovi and L. hardjo were the most prevalent.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

A reduction in the duration of infection with Tritrichomonas foetus following vaccination in heifers and the failure to demonstrate a curative effect in infected bulls

Seven batches of 25% water-phase, oil-in-water vaccine were prepared from whole cultures of Tritrichomonas foetus. Two inoculations were given, spaced 6 weeks apart, to virgin heifers and infected bulls. A significant reduction (P < 0,01) in the duration of infection in vaccinated heifers was seen when they were challenged by being bred to a bull infected with the same isolate as that contained in the vaccine. Only 1/12 vaccinated heifers were pregnant 4,5 months after the end of the breeding season compared to 2/12 in the control group. The vaccine, therefore, has no practical advantage. Vaccine was supplied to 2 724 bulls on properties where the infection was present. From these bulls, 110 reliable results were obtained, where bulls had been infected, been inoculated and tested 1 month later. No curative effect was demonstrable with 69/110 (62,7%) bulls, remaining infected after the course of inoculations. There was also no difference between vaccine batches or between bulls of different ages. Further work on improving the vaccine is indicated. Three media suitable for the culture of T. foetus are described in detail.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Heavy metal partitioning in sediments from rivers flowing through coal fields in Mpumalanga, South Africa

The association of elements Cd, Co, Cr, Fe, Mn, Pb, Ti and V with various geochemical phases in the sediments from the Olifants, Klein Olifants, Wilge rivers and a tributary of the Olifants River was studied using a four step sequential extraction scheme. By employing enrichment factors these elements were found to be contaminating the sediments. Sequential extraction enabled partitioning of the metals into exchangeable, reducible, oxidizable and residual fractions. Most of the elements were found to exist in the residual fraction, characterized by stable compounds. Application of risk assessment code (RAC) to the exchangeable fraction revealed that most of the elements posed a medium risk to aquatic life, with the exception of Co, Pb, and Mn which were classified into the high risk category. Non-residual/more bioavailable fractions were examined using statistics. Correlation analysis was employed to understand the interaction between the more bioavailable fractions of the metals with the reducible phase consisting of oxides of Fe-and Mn. These oxides contribute to the adsorption of trace metals onto sediments. Elements Co, V, Pb, Cr and Cd in the reducible fraction were found to be associated with Fe-oxides, while some V, Cr and Ti were associated with Mnoxides, as indicated by significantly high correlation coefficients. Through cluster and factor analysis three anthropogenic activities associated with mining and use of coal and iron and steel manufacturing were found to be contributing metals to the sediments.Tshwane University of Technology (TUT) and the National Research Fund (NRF).http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1863-06692016-06-30hb201

The effect of body size on the rate of decomposition in a temperate region of South Africa

Forensic anthropologists rely on the state of decomposition of a body to estimate the post-mortem- interval (PMI) which provides information about the natural events and environmental forces that could have affected the remains after death. Various factors are known to influence the rate of decomposition, among them temperature, rainfall and exposure of the body. However, conflicting reports appear in the literature on the effect of body size on the rate of decay. The aim of this project was to compare decomposition rates of large pigs (Sus scrofa; 60–90 kg), with that of small pigs (<35 kg), to assess the influence of body size on decomposition rates. For the decomposition rates of small pigs, 15 piglets were assessed three times per week over a period of three months during spring and early summer. Data collection was conducted until complete skeletonization occurred. Stages of decomposition were scored according to separate categories for each anatomical region, and the point values for each region were added to determine the total body score (TBS), which represents the overall stage of decomposition for each pig. For the large pigs, data of 15 pigs were used. Scatter plots illustrating the relationships between TBS and PMI as well as TBS and accumulated degree days (ADD) were used to assess the pattern of decomposition and to compare decomposition rates between small and large pigs. Results indicated that rapid decomposition occurs during the early stages of decomposition for both samples. Large pigs showed a plateau phase in the course of advanced stages of decomposition, during which decomposition was minimal. A similar, but much shorter plateau was reached by small pigs of >20 kg at a PMI of 20–25 days, after which decomposition commenced swiftly. This was in contrast to the small pigs of <20 kg, which showed no plateau phase and their decomposition rates were swift throughout the duration of the study. Overall, small pigs decomposed 2.82 times faster than large pigs, indicating that body size does have an effect on the rate of decomposition.University of Pretoria and the National Research Foundation (NRF) of South Africa.http://www.elsevier.com/locate/forsciinthb201