Harvesting Site Influenced the Concentration Level of Nitrogen and Mineral Status of Woody Species in Semi-Arid Areas of South Africa

Feed shortages in semi-arid areas cause a major set-back for livestock production. An understanding of the nutritive value of woody species in most parts of savanna regions can be vital to predicting what these species can offer for livestock productivity. The study assessed the variation in nitrogen and mineral concentration of leaves of woody species as influenced by harvesting site in South Africa. The study sites were communal areas in Limpopo and North West provinces. A total of 52 browse species were selected and used for this study. All statistical tests showed that there was a significant effect of species and site on both nitrogen and mineral concentrations of species. In Limpopo Province, the concentration of phosphorus and calcium was high in Adansonia Digitata species, while Androstachys Johnsonii had the lowest concentration of P and Ca. The highest (P \u3c 0.05) nitrogen level was obtained in Berchemia discolour, while the lowest (P \u3c 0.05) value was obtained in Euclea divinorum in Limpopo province. Bridelia mollis H. had the highest (P \u3c 0.05) zinc (Zn) concentration, whereas Berchemia zyheri had the lowest (P \u3c 0.05) Zn value in Limpopo province. Searsia lancea and Searsia pyroides in North-West sites had higher P when compared to all other species in the same sites. Diospyros lycioides also exhibited the highest (P \u3c 0.05) magnesium concentration level of all other species in the same sites. Prosopis velutina had the highest (P \u3c 0.05) copper (Cu) and zinc (Zn) compared to all other species in the same NW sites. Senegalia caffra, Grewia flava, Vachellia karroo, Vachellia nilotica subsp. kraussiana, Searsia leptodictya, and Melia azedarach found in the Limpopo province had the highest (P \u3c 0.05) phosphorus level when compared to the same species found in the North-West province. Senegalia caffra, Peltophorum africanum, Grewia. flava, Vachellia hebeclada, and Terminalia sericea found in the North-West province sites had the highest (P \u3c 0.05) iron levels when compared to the same species found in Limpopo province. Nitrogen concentration was regulated by the harvesting location and woody species. With the exception of Terminalia sericea, P Peltophorum africanum from Limpopo province, all browse species from all sites exhibited N concentrations more than 1.28%. There is a need to provide supplementation to those animals exposed to species that have a lower concentration of certain elements

Chlorophyll and Mineral Dynamics of Perennial Grass Species Found in Semi- Arid Rangelands of South Africa

Minerals are essential for ruminants and are mostly provided by grass species. Their growth stage is vital in the supply of these minerals. Perennial grass species have been mostly undervalued, owing to the scarce information concerning their potential feeding value and little documentation about their potential nutritive value in different growth stages. This study was conducted to investigate the chlorophyll and mineral concentration of grass species at different growth stages under greenhouse conditions at the North-West University Experimental farm, North West province, South Africa. The soil, collected from different villages, was mixed and samples were drawn for chemical analysis before being used as a potting medium. Nine grass species viz., Anthephora pubescens, Cenchrus ciliaris, Chloris gayana, Dactylis glomerata, Digitaria eriantha, Eragrostis curvula, Festuca arundinacea, Panicum maximum and Themeda triandra were used for the experiment. The grasses were harvested at different growth stages and analysed for nitrogen and minerals, and chlorophyll content (chlorophyll content index-CCI) was checked at the elongation stage only. Eragrostis curvula (47.28 CCI±1.25) had a higher (P F. arundinacea (34.50 CCI±1.25) had a lower (P \u3e 0.05) chlorophyll content. At the elongation stage, P. maximum had the highest (PA. pubescens and F. arundinacea had the lowest (PPanicum maximum (503 mg/kg) had a higher (PE. curvula at maturity stage. Anthephora pubescens, Dactylis glomerata, Eragrostis curvula, Festuca arundinacea, Panicum maximum and Themeda triandra had greater Ca, Na, N, P, Mg, K, Fe, Cu and Mn mineral concentrations. Since these grass species cannot individually supply the adequate minerals required by each livestock in different production stages, they can complement each other to meet the nutrient requirements for all livestock

Survival of atraumatic restorative treatment (ART) sealants and restorations: a meta-analysis

The purpose of this study is to perform a systematic investigation plus meta-analysis into survival of atraumatic restorative treatment (ART) sealants and restorations using high-viscosity glass ionomers and to compare the results with those from the 2005 ART meta-analysis. Until February 2010, four databases were searched. Two hundred four publications were found, and 66 reported on ART restorations or sealant survival. Based on five exclusion criteria, two independent reviewers selected the 29 publications that accounted for the meta-analysis. Confidence intervals (CI) and or standard errors were calculated and the heterogeneity variance of the survival rates was estimated. Location (school/clinic) was an independent variable. The survival rates of single-surface and multiple-surface ART restorations in primary teeth over the first 2 years were 93% (CI, 91–94%) and 62% (CI, 51–73%), respectively; for single-surface ART restorations in permanent teeth over the first 3 and 5 years it was 85% (CI, 77–91%) and 80% (CI, 76–83%), respectively and for multiple-surface ART restorations in permanent teeth over 1 year it was 86% (CI, 59–98%). The mean annual dentine lesion incidence rate, in pits and fissures previously sealed using ART, over the first 3 years was 1%. No location effect and no differences between the 2005 and 2010 survival rates of ART restorations and sealants were observed. The short-term survival rates of single-surface ART restorations in primary and permanent teeth, and the caries-preventive effect of ART sealants were high. Clinical relevance: ART can safely be used in single-surface cavities in both primary and permanent teeth. ART sealants have a high caries preventive effect

EVALUATION OF ANTIMICROBIAL AND CYTOTOXIC ACTIVITIES OF PLANT EXTRACTS FROM SOUTHERN MINAS GERAIS CERRADO

The antimicrobial activity of plant hidroethanolic extracts on bacteria Gram positive, Gram negative, yeasts, Mycobacterium tuberculosis H37 and Mycobacterium bovis was evaluated by using the technique of Agar diffusion and microdilution in broth. Among the extracts evaluated by Agar diffusion, the extract of Bidens pilosa leaf presented the most expressive average of haloes of growth inhibition to the microorganisms, followed by the extract of B. pilosa flower, of Eugenia pyriformis' leaf and seed, of Plinia cauliflora leaf which statistically presented the same average of haloes inhibitory formation on bacteria Gram positive, Gram negative and yeasts. The extracts of Heliconia rostrata did not present activity. Mycobacterium tuberculosis H37 and Mycobacterium bovis (BCG) appeared resistant to all the extracts. The susceptibility profile of Candida albicans and Saccharomyces cerevisiae fungi were compared to one another and to the Gram positive Bacillus subtilis, Enterococcus faecalis and the Gram negative Salmonella typhimurium bacteria (p > 0.05). The evaluation of cytotoxicity was carried out on C6-36 larvae cells of the Aedes albopictus mosquito. The extracts of stem and flower of Heliconia rostrata, leaf and stem of Plinia cauliflora, seed of Anonna crassiflora and stem, flower and root of B. pilosa did not present toxicity in the analyzed concentrations. The highest rates of selectivity appeared in the extracts of stem of A. crassiflora and flower of B. pilosa to Staphylococcus aureus, presenting potential for future studies about a new drug development

Isotopic composition and elemental concentrations in groundwater in the Kuiseb Basin and the Cuvelai-Etosha Basin, Namibia

We assessed environmental tracers in groundwater in two contrasting basins in Namibia; the Kuiseb Basin, which is a predominantly dry area and the Cuvelai-Etosha Basin, which is prone to alternating floods and droughts. We aimed to determine why the quality of groundwater was different in these two basins which occur in an arid environment. We analysed groundwater and surface water for the stable isotope ratios of hydrogen (δ2H) and oxygen (δ18O) by cavity ring-down spectroscopy and metals by inductively coupled plasma mass spectrometry. The δ2H and δ18O of surface water in the Cuvelai-Etosha Basin plot on an evaporation trend below the global meteoric water line (GMWL) and the local meteoric water line (LMWL). The δ2H and δ18O of some groundwater samples in the Cuvelai-Etosha Basin also plot on the evaporation trend, indicating recharge by evaporated rain or evaporated surface water. In contrast, the δ2H and δ18O of groundwater samples in the Kuiseb Basin plot mostly along the GMWL and the LMWL, indicating direct recharge from unevaporated rain or unevaporated surface water. Fifty percent of groundwater samples in the Cuvelai-Etosha Basin was potable (salinity < 1 ppt) compared to 79 % in the Kuiseb Basin. The high salinity in the groundwater of the Cuvelai-Etosha Basin does not appear to be caused by evaporation of water (evapo-concentration) on surface prior to groundwater recharge, but rather by the weathering of the Kalahari sediments. The low salinity in the Kuiseb Basin derives from rapid recharge of groundwater by unevaporated rain and limited weathering of the crystalline rocks. The order of abundance of cations in the Kuiseb Basin is Na > K > Ca > Mg vs. Na > Mg > Ca > K for the Cuvelai-Etosha Basin. For metals in the Kuiseb Basin the order of abundance is Fe > Al > V > As > Zn vs. Al > Fe > V> As > Zn for the Cuvelai-Etosha Basin. The relative abundance of cations and metals are attributed to the differences in geology of the basins and the extent of water-rock interaction. Our results show that the quality of groundwater in Cuvelai-Etosha Basin and Kuiseb Basin which vary in the extent of aridity, is controlled by the extent of water-rock interaction at the surface and in the groundwater aquifer

Evaluation of glass ionomer sealants placed according to the ART approach in a community with high caries experience: 1-year follow-up Avaliação de selantes ionoméricos realizados pela técnica do ART em comunidade com alta experiência de cárie: 1 ano de acompanhamento

The aim of this study was to investigate the retention rates and effect on occlusal caries incidence of two glass ionomers used as sealants, placed according to the Atraumatic Restorative Treatment (ART) approach, in a high caries-risk community. A total of 150 newly erupted first molars of 42 schoolchildren, between 6-8 years of age were selected. The teeth were divided into two groups: experimental and control groups. In the experimental group, 76 teeth were sealed using Vidrion R-SS White (conventional GIC) and in the control group, 74 teeth were sealed using ChemFlex-Dentsply (high-viscosity conventional GIC). The sealants were applied by one operator following the "press finger technique", described in the ART-WHO manual. Two calibrated independent examiners carried out the evaluation according to the ART criteria. The intra and inter-examiner agreements were 0.84 and 0.81, respectively. Data were submitted to Mann-Whitney and Chi-square tests (p<0.05). At the 1-year follow-up, 136 (90.7%) sealants were evaluated. In the control group: 28 (41.8%) of the sealants were partially or completely retained, 38 (56.7%) completely lost, and 1 (1.5%) was replaced by another treatment. In the experimental group, 30 (43.5%) of the sealants were partially or completely retained, 38 (55.1%) were clinically scored as complete loss and 1 (1.4%) were replaced by another treatment. Seven sealants in both groups were not evaluated. Secondary caries was not observed in both groups. There was no statistically significant difference between the retention (p=0.49) and effect on caries incidence rates for both groups (p=0.84). The clinical performance of the glass ionomer sealants of both groups was considered satisfactory with a high success rate (98.5%). Although the sealants placed according to the ART approach showed retention rates lower than 50% after 1 year in newly erupted first molars, this approach seems to be appropriate for communities with high caries experience.<br>O objetivo deste trabalho foi avaliar o índice de retenção e o efeito na incidência de cárie oclusal de dois selantes ionoméricos realizados pela técnica do Tratamento Restaurador Atraumático (ART) em comunidades com alto índice de cárie. Foram selecionados 150 primeiros molares recém-erupcionados de 42 escolares, entre 6-8 anos de idade. Os dentes foram divididos em dois grupos: experimental e controle. No grupo experimental 76 dentes foram selados com Vidrion R-SSWhite (CIV-convencional) e no grupo controle, 74 dentes foram selados com ChemFlex-Dentsply (CIV-alta viscosidade). Os selantes foram realizados por apenas um operador pela técnica da "pressão digital", descrita no manual de ART da OMS. Dois avaliadores independentes e calibrados segundo os critérios do ART realizaram a avaliação. A concordância intra e inter-examinadores foi de 0,84 e 0,81, respectivamente. Os resultados foram submetidos aos testes Mann-Whitney e Q-quadrado (p<0,05). Após um ano, 136 (90,7%) selante foram avaliados. No grupo controle, 28 (41,8%) selantes estavam parcial ou completamente retidos, 38 (56,7%) completamente perdidos, 1 (1,5%) foi substituído por outro tratamento. No grupo experimental, 30 (43,5%) selantes estavam parcial ou completamente retidos, 38 (55,1%) foram classificados como completamente perdidos e 1(1,4%) foi substituído por outro tratamento. Sete selantes em ambos os grupos não foram avaliados. A presença de lesão cariosa secundária não foi observada em nenhum dos grupos. Não houve diferença estatisticamente significante entre a retenção (p=0,49) e efeito na incidência de cárie (p=0,84) entre os dois grupos. A performance clínica dos selantes ionoméricos foi considerada satisfatória com um alto índice de sucesso (98,5%). Embora os selantes aplicados de acordo com a técnica ART tenham mostrado índices de retenção abaixo de 50% depois de um ano nos primeiros molares recém-erupcionados, este método mostrou-se apropriado para comunidades com alta experiência de cárie