Comparing Three Spaceborne Optical Sensors via Fine Scale Pixel-based Urban Land Cover Classification Products

Accessibility to higher resolution earth observation satellites suggests an improvement in the potential for fine scale image classification. In this comparative study, imagery from three optical satellites (WorldView-2, Pleiades and RapidEye) were used to extract primary land cover classesfrom a pixel-based classification principle in a suburban area. Following a systematic working procedure, manual segmentation and vegetation indices were applied to generate smaller subsets to in turn develop sets of ISODATA unsupervised classification maps. With the focus on the land cover classification differences detected between the sensors at spectral level, the validation of accuracies and their relevance for fine scale classification in the built-up environment domain were examined. If an overview of an urban area is required, RapidEye will provide an above average (0.69 k) result with the built-up class sufficiently extracted. The higher resolution sensors such as WorldView-2 and Pleiades in comparison delivered finer scale accuracy at pixel and parcel level with high correlation and accuracy levels (0.65-0.71k) achieved from these two independent classifications

Bydraende faktore tot leerderdissiplineprobleme: ’n Multiveranderlike analise

Contributory factors to learner discipline problems: A multivariate approach. Hitherto, researchers in the field of the various causal or contributory factors of learner discipline problems in schools tended to approach each of those factors in isolation. This article reported on research regarding the theoretically justifiable notion of the confluence of the various factors that culminate in learner discipline problems at school. Grade 9 learners as well as their educators completed questionnaires in which they had to indicate on a semantic differential scale the extent to which they thought each of the 36 possible causes played a role in the incidence of learner discipline problems in their school. Routine factor analysis revealed that seven factors contributed to learner misbehaviour in their particular school, namely social problems in society, the influence of parents on the behaviour of their children, the authority of the educator, democratic participation in school governance, the nature of school structures, and also physical and psychological disabilities

Direct anthelmintic effects of Cereus jamacaru (Cactaceae) on trichostrongylid nematodes of sheep : in vivo studies

Following claims of anthelmintic activity of Cereus jamacaru DC (Cactaceae) by a commercial farmer, in vivo studies were conducted to determine the possible direct anthelmintic effects of the plant on ovine gastrointestinal nematodes. Eighteen sheep were infected with 4000 Haemonchus contortus and 6000 Trichostrongylus colubriformis larvae given in three divided doses over a period of three days. Once the infections were patent, the sheep were allocated to three groups and were drenched once a week for six weeks with fresh blended C. jamacaru plant material at a single (32.3 g/sheep) or double dose (64.6 g/sheep) or they remained as undrenched controls. Faeces were collected from individual animals on the day of treatment and three days thereafter on a weekly basis for seven weeks for faecal egg count. While there were no statistically significant differences in the egg counts between the groups, a double dose of C. jamacaru was effective in reducing the egg counts in the sheep by 18-65% over the 49 days of the experiment. Given that all animals remained in good health throughout the course of the experiment, with no adverse events occurring during the study, further experiments using higher doses or administering the plant material for a longer period of time than in the present study would be warranted.The National Research Foundation of South Africa (NRF), the Phytomedicine Programme of the Faculty of Veterinary Science, University of Pretoria and the Onderstepoort Veterinary Institute (OVI) provided financial support.http://www.elsevier.com/locate/vetpa

Investigation of the mechanism of anti-inflammatory action and cytotoxicity of a semipurified fraction and isolated compounds from the leaf of Peltophorum africanum (Fabaceae)

Peltophorum africanum extracts have been shown to possess many important medicinal benefits, including anti-inflammatory and antiviral activities. However, the mechanism of action is poorly understood. The mechanism of anti-inflammatory action was determined by measuring the synthesis of cytokines in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophage cells in vitro. Compound 1 (CP1), compound 2 (CP2), and fraction F3.3.0 (F3.3.0) significantly reduced the synthesis of interleukin 1β (IL-1β) from RAW 264.7 cells (1.18, 1.32, and 0.92 ng/mL), respectively. Similarly, CP1, CP2, and F3.3.0 inhibited the production of IL-2 and tumor necrosis factor-α (TNF-α) by RAW 264.7 cells (0.41, 0.60, 0.74 and 0.11, 0.27, 0.24 ng/mL, respectively. In addition, CP1 and CP2 had lower cytotoxicity toward RAW 264.7 cells, with CP2 indicating the lowest cytotoxicity (LD50 = 207.88 µg/mL). The mechanism of action was found to be via the inhibition of pro-inflammation cytokines (IL-1 β and TNF-α). This observation may support the use of P africanum to treat pain-related conditions.The National Research Foundation of South Africa through grant number SFP150708124126.http://journals.sagepub.com/home/chpam2018Immunolog

Understanding of the farmers' privilege concept by smallholder farmers in South Africa

Legislation on plant breeders’ rights – the Plant Breeders’ Rights Act, 1976 (Act No. 15 of 1976) – currently is being reviewed by the Department of Agriculture, Forestry and Fisheries. This legislation provides for farmers’ privilege, which is one of the exceptions to plant breeders’ rights. It allows farmers to save seed of protected varieties for their own use. Farmers’ privilege, and particularly its impact on smallholder farmers in developing countries, is a widely debated issue. During the public consultation process, several comments proposing amendments to the farmers’ privilege provision were received from various stakeholders. However, no comments were received from the smallholder farmers who may be directly impacted by this provision. This pilot study was undertaken to assess the understanding of the farmers’ privilege concept by smallholder farmers from the historically disadvantaged communities and their current practices with regard to seed saving. The results showed that the majority of the smallholder farmers were not aware of the existence of the legislation on plant breeders’ rights and therefore do not understand the farmers’ privilege concept and its implications. They also did not know whether the varieties they were using were protected by plant breeders’ rights or not. Little information has been published on the impact of plant breeders’ rights in South Africa in general. We hope that this study might inform policy decisions on matters related to plant breeders’ rights and the farmers’ privilege.http://www.sajs.co.za/hb201

Application of direct bioautography and SPME-GC-MS for the study of antibacterial chamomile ingredients

The isolation and characterization of antibacterial chamomile components were performed by the use of direct bioautography and solid phase microextraction (SPME)-GC-MS. Four ingredients, active against Vibrio fischeri, were identified as the polyacetylene geometric isomers cis- and trans-spiroethers, the coumarin related herniarin, and the sesquiterpene alcohol (-)-alpha-bisabolol

Novel Mycobacterium avium species isolated from Black Wildebeest (Connochaetes gnou) in 5 South Africa

A study was undertaken to isolate and characterize Mycobacterium species from black wildebeest suspected of being infected with tuberculosis in South Africa. This led to the discovery of a new Mycobacterium avium species, provisionally referred to as the Gnou isolate from black wildebeest (Connochaetus gnou). Sixteen samples from nine black wildebeest were processed for Mycobacterium isolation. Following decontamination; samples were incubated in an ordinary incubator at 37°C on Löwenstein-Jensen slants and in liquid medium tubes using the BACTECTM MGITTM 960 system respectively. Identification of the isolate was done by standard biochemical tests and using the line probe assay from the GenoType® CM/AS kit (Hain Life Science GmbH, Nehren, Germany). The DNA extract was also analyzed using gene sequencing. Partial gene sequencing and analysis of 16S rRNA gene, 16S-23S rRNA (ITS), rpoB and hsp65 and phylogenetic analyses by searching GenBank using the BLAST algorithm were conducted. Phylogenetic trees were constructed using four methods, namely Bayesian inference, maximum likelihood, maximum parsimony and neighbor-joining methods. The isolate was identified as Mycobacterium intracellulare using the GenoType® CM/AS kit and as Mycobacterium avium complex (MAC) by gene sequencing. The gene sequence targeting all the genes, ITS, 16S rRNA, rpoB and hsp65 and phylogenetic analyses indicated that this isolate presented a nucleotide sequence different from all currently published sequences, and its position was far enough from other MAC species to suggest that it might be a new species.NRF; Bilateral research collaboration between South Africa and the Japan Society for the Promotion of Science (JSPS); UnisaAgriculture and  Animal Healt

Conservation law enforcement : policing protected areas

This article examines how recent increases in commercial poaching of wildlife intensify the dictates that underpin conservation law and its enforcement; namely, the securing of space, punishing of transgressors, and protecting of nonhuman life. Drawing on ethnographic research with antipoaching personnel in Mozambique, I examine how rangers translate these legal and normative manifestations of conservation law enforcement on the ground and in their daily practices to police protected areas and the wildlife within them. This article makes two contributions. First, drawing on insights from the political geography and ecology of conservation with the political geography of policing, I demonstrate how territorial, sovereign, and biopolitical practices and logics coalesce to secure the spaces and the lives of the nonhuman from ostensible human threats. Second, it is rangers who are deployed as petty environmental sovereigns to achieve these objectives through often violent practices. Although many rangers might feel uncomfortable with the use of violence, their agency to commit or resist using violence is authorized, enabled, and constrained by the normative and legal structures of conservation law enforcement within which they operate. The social differentiation among rangers also means that some have more agency to navigate these structures than others. These insights help understand the actually existing operationalization of delegated and performative power over bodies, space, and the use of direct violence. I suggest that critiques of conservation violence, and the use of violence by those acting as petty sovereigns more broadly, should be primarily oriented at the broader structures within which they operate

Evaluation of the antibacterial and anticancer activities of some South African medicinal plants

<p>Abstract</p> <p>Background</p> <p>Several herbs are traditionally used in the treatment of a variety of ailments particularly in the rural areas of South Africa where herbal medicine is mainly the source of health care system. Many of these herbs have not been assessed for safety or toxicity to tissue or organs of the mammalian recipients.</p> <p>Methods</p> <p>This study evaluated the cytotoxicity of some medicinal plants used, inter alia, in the treatment of diarrhoea, and stomach disorders. Six selected medicinal plants were assessed for their antibacterial activities against ampicillin-resistant and kanamycin-resistant strains of <it>Escherichia coli </it>by the broth micro-dilution methods. The cytotoxicities of methanol extracts and fractions of the six selected plants were determined using a modified tetrazolium-based colorimetric assay (3-(4, 5-dimethylthiazol)-2, 5-diphenyl tetrazolium bromide (MTT) assay).</p> <p>Results</p> <p>The average minimum inhibitory concentration (MIC) values of the plants extracts ranged from 0.027 mg/mℓ to 2.5 mg/mℓ after 24 h of incubation. <it>Eucomis autumnalis </it>and <it>Cyathula uncinulata </it>had the most significant biological activity with the least MIC values. The in vitro cytotoxicity assay on human hepatocarcinoma cell line (Huh-7) revealed that the methanol extract of <it>E. autumnalis </it>had the strongest cytotoxicity with IC₅₀of 7.8 μg/mℓ. Ethyl acetate and butanol fractions of <it>C. uncinulata, Hypoxis latifolia, E. autumnalis </it>and <it>Lantana camara </it>had lower cytotoxic effects on the cancer cell lines tested with IC₅₀values ranging from 24.8 to 44.1 μg/mℓ; while all the fractions of <it>Aloe arborescens </it>and <it>A. striatula </it>had insignificant or no cytotoxic effects after 72 h of treatment.</p> <p>Conclusions</p> <p>Our results indicate that the methanol fraction of <it>E. autumnalis </it>had a profound cytotoxic effect even though it possessed very significant antibacterial activity. This puts a query on its safety and hence a call for caution in its usage, thus a product being natural is not tantamount to being entirely safe. However, the antibacterial activities and non-cytotoxic effects of <it>A. arborescens </it>and <it>A. striatula </it>validates their continuous usage in ethnomedicine.</p

Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens

The aim of this study was to compare the effects of cryopreservation at approximately -196 °C in liquid nitrogen (N) and freezing at approximately -20 °C in a freezer, on the viability and survival of eight different mastitogenic bacteria inoculated in milk. Bacteria were frozen at approximately -20 °C in a freezer and cryopreserved at approximately -196 °C in liquid nitrogen. An effective preservation method was needed for follow-up samples from cows identified in the South African National Milk Recording Scheme (NMRS) with somatic cell counts above 250 000 cells/mL milk. The organisation responsible for sample collection of the NMRS milk samples also provides producers with liquid nitrogen for their semen flasks at the collection sites. This existing mode of storage and transport could therefore be utilised. Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH) (phage type lytic group III) or Sta. aureus (STA) (phage typed, other than lytic group III). Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation. Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds.I.M.P. (University of Pretoria) was the project leader. I.M.P. (University of Pretoria), J.C.W. (University of Pretoria) and T.J.v.d.S. (University of Pretoria) were responsible for experimental and project design. N.M.I. (Herd Husbandry Help CC) assisted with the storage of samples in liquid nitrogen (-196 ºC) by making facilities available. S.E. (University of Pretoria) assisted with data capturing. J.K. (University of Pretoria) and I.M.P. (University of Pretoria) were responsible for the literature review, the writing-up of the article, and G.T.F. (University of Pretoria) assisted with data utilisation and statistical analysis.http://www.ojvr.orgab201