90 research outputs found

    Meerkat Maths – a comprehensive maths learning programme for Grade-R

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    Abstract: Background: Several studies have shown the influence of mathematical knowledge on both individual opportunities and chances for a self-determined and prosperous life as well as the welfare of nations. Against this background, the contents of maths education in the foundation phase as well as the way in which it is conveyed gain importance. While competence-oriented approaches (e.g. the Curriculum Assessment Policy Statements [CAPS]) state learning goals that all learners should achieve, developmental approaches (e.g. developmental models) describe typical learning trajectories of learners. As both approaches are quite separated, there is a need for bridging the gap between them. Aim: This article aims at revisiting the CAPS critically and comparing contents for early numeracy instruction. A possible alternative to the CAPS is intended. Setting: In this article, we describe a maths learning programme for Grade-R (Meerkat Maths) that combines and integrates empirical findings and curricular demands. The presented maths training aims at teaching maths in such a way that it suits children’s development, raises a positive attitude towards maths and also meets educational expectations. Methods: Contents of the training programme and the CAPS are compared against the background of empirical research on numerical development and predictors for arithmetic performance. Results: The results reveal that research based math instruction can be conveyed in a formal training programme. Conclusion: Keeping in mind the qualifications and training of Grade-R teachers, teacher training is necessarily embedded in the programme. Thus, the described programme is a comprehensive application of recent research for maths classes in the early grades

    Geographic range of vector-borne infections and their vectors : the role of African wildlife

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    The role of African wildlife in the occurrence of vector-borne infections in domestic animals has gained renewed interest as emerging and re-emerging infections occur worldwide at an increasing rate. In Africa, biodiversity conservation and the expansion of livestock production have increased the risk of transmitting vector-borne infections between wildlife and livestock. The indigenous African pathogens with transboundary potential, such as Rift Valley fever virus, African horse sickness virus, bluetongue virus, lumpy skin disease virus, African swine fever virus, and blood-borne parasites have received the most attention. There is no evidence for persistent vector-borne viral infections in African wildlife. For some viral infections, wildlife may act as a reservoir through the inter-epidemic circulation of viruses with mild or subclinical manifestations. Wildlife may also act as introductory or transporting hosts when moved to new regions, e.g. for lumpy skin disease virus, Rift Valley fever virus and West Nile virus. Wildlife may also act as amplifying hosts when exposed to viruses in the early part of the warm season when vectors are active, with spillover to domestic animals later in the season, e.g. with bluetongue and African horse sickness. Some tick species found on domestic animals are more abundant on wildlife hosts; some depend on wildlife hosts to complete their life cycle. Since the endemic stability of a disease depends on a sufficiently large tick population to ensure that domestic animals become infected at an early age, the presence of wildlife hosts that augment tick numbers may be beneficial. Many wild ungulate species are reservoirs of Anaplasma spp., while the role of wildlife in the epidemiology of heartwater (Ehrlichia ruminantium infection) has not been elucidated. Wild ungulates are not usually reservoirs of piroplasms that affect livestock; however, there are two exceptions: zebra, which are reservoirs of Babesia caballi and Theileria equi, and buffalo, which are reservoirs of Theileria parva. The latter causes Corridor disease when transmitted from buffalo to cattle, but this appears to be a self-limiting condition, at least in southern Africa. Wild animals are important reservoirs of tsetse-transmitted Trypanosoma spp. infection. The distribution and abundance of some tsetse species, e.g. Glossina morsitans and G. pallidipes, are closely related to the occurrence of their preferred wildlife hosts.http://www.oie.int/en/publications-and-documentation/scientific-and-technical-review-free-accessam201

    Bluetongue: a historical and epidemiological perspective with the emphasis on South Africa

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    Bluetongue (BT) is a non-contagious, infectious, arthropod transmitted viral disease of domestic and wild ruminants that is caused by the bluetongue virus (BTV), the prototype member of the Orbivirus genus in the family Reoviridae. Bluetongue was first described in South Africa, where it has probably been endemic in wild ruminants since antiquity. Since its discovery BT has had a major impact on sheep breeders in the country and has therefore been a key focus of research at the Onderstepoort Veterinary Research Institute in Pretoria, South Africa. Several key discoveries were made at this Institute, including the demonstration that the aetiological agent of BT was a dsRNA virus that is transmitted by Culicoides midges and that multiple BTV serotypes circulate in nature. It is currently recognized that BT is endemic throughout most of South Africa and 22 of the 26 known serotypes have been detected in the region. Multiple serotypes circulate each vector season with the occurrence of different serotypes depending largely on herd-immunity. Indigenous sheep breeds, cattle and wild ruminants are frequently infected but rarely demonstrate clinical signs, whereas improved European sheep breeds are most susceptible. The immunization of susceptible sheep remains the most effective and practical control measure against BT. In order to protect sheep against multiple circulating serotypes, three pentavalent attenuated vaccines have been developed. Despite the proven efficacy of these vaccines in protecting sheep against the disease, several disadvantages are associated with their use in the field

    Seroepidemiological survey of sympatric domestic and wild dogs (Lycaon pictus) in Tsumkwe District, north-eastern Namibia

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    Disease is a potential threat to many endangered populations and may originate from sympatric domestic species. This paper describes a cross-sectional serological survey of canine pathogens carried out in domestic (n = 70) and wild dogs (Lycaon pictus) (n = 6), in Tsumkwe District, northeastern Namibia. Evidence of past exposure to canine distemper virus, canine adenovirus and parainfluenza virus was evident in both wild and domestic dogs with this, the first, documented exposure of free-living wild dogs to canine distemper. Domestic dogs were also exposed to rabies virus, canine parvovirus and coronavirus. There was no pathogen to which wild dogs, but not domestic dogs, were exposed. With wild dogs known to be susceptible to rabies and canine distemper, these may be the greatest threat to this population of wild dogs, although some wild dogs can clearly survive infection with canine distemper.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.British Ecological Society. Grand Canyon Spur, Windhoek. Ministry of Environment and Tourism. WWF (US)

    Comparing the minimum inhibitory and mutant prevention concentrations of selected antibiotics against animal isolates of Pasteurella multocida and Salmonella typhimurium

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    This article forms part of the published thesis of J.M.W. submitted in partial fulfilment of the requirements for the degree of Magister Scientiae (Veterinary Tropical Diseases) in the Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, South Africa, entitled ‘A comparative study of the minimum inhibitory and mutant prevention concentrations of florfenicol and oxytetracycline for animal isolates of Pasteurella multocida and Salmonella Typhimurium’. Supervisor: M.v.V., 2012. Refer to link: https://repository.up.ac.za/handle/ 2263/26219.DATA AVAILABILITY : The raw data is available on the University of Pretoria repository as part of the M. thesis at https://repository. up.ac.za/handle/2263/26219.Historically, the use of antibiotics was not well regulated in veterinary medicine. The emergence of antibiotic resistance (ABR) in pathogenic bacteria in human and veterinary medicine has driven the need for greater antibiotic stewardship. The preservation of certain antibiotic classes for use exclusively in humans, especially in cases of multidrug resistance, has highlighted the need for veterinarians to reduce its use and redefine dosage regimens of antibiotics to ensure efficacy and guard against the development of ABR pathogens. The minimum inhibitory concentration (MIC), the lowest concentration of an antibiotic drug that will prevent the growth of a bacterium, is recognised as a method to assist in antibiotic dosage determination. Minimum inhibitory concentrations sometimes fail to deal with first-step mutants in bacterial populations; therefore dosing regimens based solely on MIC can lead to the development of ABR. The mutant prevention concentration (MPC) is the minimum inhibitory antibiotic concentration of the most resistant first-step mutant. Mutant prevention concentration determination as a complementary and sometimes preferable alternative to MIC determination for veterinarians when managing bacterial pathogens. The results of this study focused on livestock pathogens and antibiotics used to treat them, which had a MIC value of 0.25 μg/mL for enrofloxacin against all 27 isolates of Salmonella typhimurium. The MPC values were 0.50 μg/mL, with the exception of five isolates that had MPC values of 4.00 μg/mL. The MPC test yielded 65.52% (18 isolates) Salmonella isolates with florfenicol MICs in the sensitive range, while 11 isolates were in the resistant range. Seventeen isolates (58.62%) of Pasteurella multocida had MIC values in the susceptible range and 41.38% (12 isolates) had an intermediate MIC value. Mutant prevention concentration determinations as done in this study is effective for the antibiotic treatment of bacterial infections and minimising the development of resistance. The MPC method can be used to better control to prevent the development of antibiotic drug resistance used in animals.http://www.ojvr.orgam2023Production Animal StudiesVeterinary Tropical Disease

    Comparison of nucleotide sequences of recent and previous lineages of peste-des-petits-ruminants viruses of sheep and goats in Nigeria

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    Peste-des-petits-ruminants virus (PPRV) is a highly contagious, fatal and economically important viral disease of small ruminants that is still endemic and militates against the production of sheep and goats in endemic areas of the world. The aim of this study was to describe the viral strains within the country. This was carried out by collecting tissue and swab samples from sheep and goats in various agro-ecological zones of Nigeria. The phylogeny of archived PPRV strains or isolates and those circulating and causing recent outbreaks was determined by sequencing of the nucleoprotein (N)-gene. Twenty tissue and swab samples from apparently healthy and sick sheep and goats were collected randomly from 18 states, namely 3 states in each of the 6 agro-ecological zones visited. A total of 360 samples were collected. A total of 35 samples of 360 (9.7%) tested positive by reverse transcriptase–polymerase chain reaction, of which 25 were from oculo-nasal swabs and 10 were from tissue samples. Neighbour-joining phylogenetic analysis using Phylogenetic Analysis Using Parsimony (PAUP) identified four different lineages, that is, lineages I, II, III and IV. Interestingly, the Nigerian strains described in this study grouped in two separate major lineages, that is, lineages II and IV. Strains from Sokoto, Oyo, Plateau and Ondo states grouped according to the historical distribution of PPRV together with the Nigerian 75/1 strain of lineage II, while other strains from Sokoto, Oyo, Plateau, Akwa-Ibom, Adamawa, Kaduna, Lagos, Bauchi, Niger and Kano states grouped together with the East African and Asian strains of lineage IV. This finding confirms that both lineage II and IV strains of PPRV are circulating in Nigeria. Previously, only strains of lineage II were found to be present in the country.Dr Mohammed S. Ahmed, Executive Director, NVRI Vomhttp://www.ojvr.orgam2016Veterinary Tropical Disease

    The prevalence of Culicoides spp.in 3 geographic areas of South Africa

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    The seasonal abundance of Culicoides midges, the vector of Bluetongue and African horse sickness viruses (BTV/AHSV) and the presence of viruses in midges were determined in 3 geographic areas in South Africa. In the Onderstepoort area, more than 500,000 Culicoides midges belonging to 27 species were collected. Eighteen midge species were collected throughout Winter and the presence of AHSV and BTV RNA in midges was detected using real time reverse transcription quantitative polymerase chain reaction. The nucleic acid of AHSV was found in 12 pools out of total pools of 35 Culicoides. Twenty‑five Culicoides species were detected in the Mnisi area. The RNA of BTV was detected in 75.9% of the midge pools collected during Winter and 51.2% of those collected during Autumn. Antibodies for BTV were detected in 95% of cattle sampled using a competitive enzyme‑linked immunosorbent assay (cELISA). The dominant species in these 2 areas was Culicoides imicola. Eight Culicoides species were collected in Namaqualand. Culicoides imicola represented the 0.9% and Culicoides bolitinos the 1.5% of total catches, respectively. Antibodies for AHSV were detected in 4.4% of 874 equines tested using an indirect ELISA. Results showed that transmission of AHSV and BTV can carry on throughout Winter and the outbreak may begin as soon as Culicoides populations reach a certain critical level. [Abstract] I Culicoides sono noti vettori del virus della Bluetongue (BTV) e del virus della Peste equina africana (AHSV). Il lavoro riporta i risultati sull'abbondanza stagionale di Culicoides e sulla presenza di BTV e AHSV in diversi vettori, in tre aree geografiche del Sudafrica. Nell'area di Onderstepoort sono stati individuati più di 500.000 esemplari di Culicoides appartenenti a 27 specie diverse. Durante la stagione invernale sono state individuate 18 specie. Frammenti di RNA di AHSV e BTV sono stati rilevati mediante specifiche RT-qPCR. L'RNA del virus AHSV è stato individuato in 12 pool di Culicoides su 35 esaminati. Nell'area di Mnisi sono state identificate 25 specie di Culicoides. L'RNA di BTV è stato rilevato nel 75,9% dei pool di Culicoides catturati durante la stagione invernale e nel 51,2% di quelli catturati durante la stagione autunnale. Anticorpi contro BTV sono stati osservati nel 95% dei sieri prelevati da bovini dell'area di Mnisi ed esaminati con il metodo c‑ELISA. La specie dominante in queste due aree è risultata Culicoides imicola. Nella regione di Namaqualand sono state individuate otto specie, C. imicola ha rappresentato lo 0,9% delle specie catturate e Culicoides bolitinos l'1,5%. Anticorpi contro il virus AHSV sono stati individuati mediante ELISA nel 4,4% degli 874 equini esaminati. I risultati ottenuti hanno dimostrato che in Sudafrica la trasmissione di BTV e AHSV può continuare durante la stagione invernale mentre, con ogni probabilità, si ha la comparsa dei primi focolai quando le diverse popolazioni di Culicoides raggiungono un livello riproduttivo critico

    Efficacy of vaccination at 4 and 6 weeks in the control of canine parvovirus

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    Seroconversion after early vaccination at four weeks against canine parvovirus (CPV) using a high antigen titre vaccine was evaluated in 121 puppies from three breeds of dogs housed in kennels representative of the private practitioner's environment. The trial included 52 German shepherd pups, 25 Rottweiler pups and 44 Boerboel pups. From each group 11, 4, and 18 puppies acted as control dogs, respectively. Depending on the different groups, puppies were vaccinated at 4, 6, 9 and 12 weeks. The experimental group differed from the control group in that they received the high titre vaccine at 4 weeks of age, whereas the control group was not vaccinated at 4 weeks. Blood was collected from all pups prior to vaccination to measure maternally derived colostral antibody. The results indicated that vaccination at 4 weeks of age in pups with high maternally derived antibody levels, results in seroconversion rates that may lead to a reduction in the window of susceptibility with respect to CPV infection. The implications of the findings with respect to dogs in heavily contaminated environments are discussed.Appendix A. Supplementary datahttp://www.elsevier.com/locate/vetmi

    Malignant catarrhal fever : an emerging disease in the African buffalo (Syncerus caffer)

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    Within the tribe Bovini in the subfamily Bovinae, the water buffalo (Bubalus Bubalis), American bison (Bison bison), European bison (Bubalus bonasus) and yak (Bos grunniens) are recognized as species highly susceptible to malignant catarrhal fever (MCF). In contrast, the lack of reports describing clinical MCF in the African buffalo (Syncerus caffer) whether free ranging or captive has led to a perception that African buffaloes are resistant to MCF. During the last decade, several cases of MCF in African buffaloes were confirmed in South Africa and experience with seven of these cases is described in this report. Detection of viral nucleic acid in blood or tissues was successful in six African buffaloes that suffered from clinical signs compatible with MCF. Four were positive for infection with ovine herpesvirus type 2 (the causative virus of sheep-associated MCF), and two were positive for alcelaphine herpesvirus type 1 (causative virus of wildebeestassociated MCF). Histopathological examination of tissue samples from all the animals yielded typical lesions that were consistent with those described for MCF in domestic cattle. Developments in the management of African buffaloes translocated from their traditional habitats have likely contributed to the identification of another susceptible host in the subfamily Bovinae.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1865-16822016-06-30hb201

    Molecular characterisation of Mycoplasma species isolated from the genital tract of Dorper sheep in South Africa

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    Biochemical and molecular analysis were conducted on 34 strains of Mycoplasma species isolated between 2003 and 2009 from the genital tract of clinically healthy Dorper sheep and sheep with ulcerative vulvitis and balanitis. Earlier publications identified the causative agent as Mycoplasma mycoides mycoides large colony (MmmLC) and Arcanobacterium pyogenes. The aims of the study were to characterise Mycoplasma species isolated from the genital tract of Dorper sheep with polymerase chain reaction assay, cloning and gene sequencing. Basic Local Alignment Search Tool (BLAST) results revealed six predominant Mycoplasma species: Mycoplasma arginini, Mycoplasma bovigenitalium, Arcanobacterium laidlawii, MmmLC, Mycoplasma sp. ovine/caprine serogroup II and M. canadense. Sequencing of the 34 isolates were analysed using phylogenetic methods, and 18 (50%) were identified as M. arginini with 99% – 100% similarity to M. arginini from England and Sweden. Six isolates showed 99% similarity to M. bovigenitalium strains from Turkey and Germany. Two isolates had 99% similarity to an M. sp. ovine/caprine sero group II from the United Kingdom. BLAST for two isolates revealed 99% similarity to Acholeplasma laidlawii from India, another two were 99% similar to MmmLC strain from Sweden, two showed 98% similarity to Mycoplasma sp. Usp 120 from Brazil, and two isolates have a 97% – 99% similarity to M. mm. Jcv1 strain from the United States of America. Finally, one isolate showed similarity of 99% to Mycoplasma canadense strain from Italy. The findings support the hypothesis that ulcerative vulvitis and balanitis of Dorper sheep in South Africa (SA) is a multifactorial disease with involvement of different Mycoplasma species.http://www.jsava.co.zaam201
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