Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Ambio ; 52(3): 598-615, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36583831

RESUMEN

Conservationists speculated on potential benefits to wildlife of lockdown restrictions because of the COVID-19 pandemic but voiced concern that restrictions impeded nature conservation. We assessed the effects of lockdown restrictions on biodiversity conservation in South Africa, a biodiverse country with economic inequality and reliance on wildlife resources. We solicited expert opinion using the IUCN's Threats Classification Scheme to structure a questionnaire and illustrated responses with individual case studies from government parastatal and non-governmental conservation organisations. The most highly reported threats were biological resource use, residential/commercial developments, invasive species, and human intrusions. The trends reported by 90 survey respondents were supported by case studies using environmental compliance data from parastatal conservation organisations. Lack of tourism revenue and funding were cited as hindrances to conservation. Mechanisms to prevent environmental degradation in the face of global emergencies must be implemented and 'ring-fenced' to ensure conservation is not a casualty during future global crises.


Asunto(s)
COVID-19 , Conservación de los Recursos Naturales , Animales , Humanos , Animales Salvajes , Control de Enfermedades Transmisibles/legislación & jurisprudencia , COVID-19/prevención & control , Sudáfrica , Encuestas y Cuestionarios
2.
Pest Manag Sci ; 75(1): 63-78, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30094905

RESUMEN

BACKGROUND: The route and rate of degradation of thiamethoxam in the laboratory and field was investigated. The effect of dark incubation versus light/dark cycles, seed treatment versus spray, and watering-in for spray application was explored in side-by-side trials. RESULTS: Geometric mean DT50 values were 75.4 days in OECD307 studies, and 18.3 (spray) and 16.5 (seed treatment) days in the field. In laboratory soil core studies DT50 values were 24.9 to 43.5 days, with the lowest value from the light/dark incubated soil core. Mean clothianidin formation was 19.7% applied thiamethoxam [mol/mol] in OECD307 studies and 17.5 (spray) and 3.4% (seed) in field trials. CONCLUSION: Soil DT50 values decreased with increasingly realistic tests (laboratory OECD307 to soil cores to soil cores with a light/dark cycle to field trials). The majority of the differences were associated with the soil treatment in OECD307 studies which destroys soil structure and retards the degradation rate; and from the impact on soil pore water movement in light/dark conditions. Degradation rates in the field were comparable between spray application and seed treatments. Maximum clothianidin concentrations were four-fold lower for seed treatments than for spray application in field studies. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Asunto(s)
Insecticidas/química , Contaminantes del Suelo/química , Suelo/química , Tiametoxam/química
3.
Pest Manag Sci ; 72(2): 388-97, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25884469

RESUMEN

BACKGROUND: Thiamethoxam is a systemic and contact pesticidal active substance in the neonicotinoid class of insecticides used worldwide to control a range of insects. Recently, concerns have been expressed regarding possible effects of neonicotinoids on bees and other wildlife. The DT50 of thiamethoxam in soil may be crucial to assessing the potential long-term exposure of non-target organisms to thiamethoxam. There are currently no detailed publicly available data for the field soil degradation of thiamethoxam under European conditions. We give field soil DT50 values of thiamethoxam from studies conducted in several European locations, under a range of realistic agronomic conditions. RESULTS: Field soil DT50 values normalised to 20 °C ranged between 7.1 and 92.3 days (geomean = 31.2 days; n = 18). CONCLUSION: The degradation rate of thiamethoxam was not significantly affected by application type, cropped fields versus bare soil, soil pH, organic matter content or repeated annual applications. Soil photolysis and leaching were negligible; therefore, calculated DT50 values were taken to represent microbial degradation. The field degradation rates of thiamethoxam were faster than those previously reported from laboratory degradation studies. They demonstrate that thiamethoxam will degrade to concentrations that are <10% of the maximum within a year of application, and will not accumulate in soil after repeated applications.


Asunto(s)
Abejas/efectos de los fármacos , Nitrocompuestos/química , Oxazinas/química , Plaguicidas/química , Contaminantes del Suelo/química , Suelo/química , Tiazoles/química , Animales , Concentración de Iones de Hidrógeno , Insecticidas/química , Insecticidas/metabolismo , Neonicotinoides , Nitrocompuestos/metabolismo , Oxazinas/metabolismo , Plaguicidas/metabolismo , Contaminantes del Suelo/metabolismo , Tiametoxam , Tiazoles/metabolismo
4.
Anal Bioanal Chem ; 376(5): 701-5, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12768264

RESUMEN

A liquid chromatography method was developed for the determination of antifungal/antimicrobial proteins Rs-AFP1 and Dm-AMP1 in sandy loam soils. The extraction of these highly basic proteins was achieved by mechanical shaking with aqueous Tris buffer pH 9 containing guanidinium thiocyanate salt (4.1 M), EDTA and nonionic polyoxyethylene 20 cetyl ether, Brij-58 detergent. The extracts were cleaned up on Oasis HLB polymer solid-phase extraction cartridges and quantified by liquid chromatography fluorescence detection based on the fluorescence properties of the tryptophan content of these proteins. The detector response was linear for 0.3-10 microg mL(-1). Procedural recoveries were tested in the range 10-100 mg kg(-1). The limit of quantification was 10 mg kg(-1 )protein in the soil sample representing the lowest validated fortification level. The antifungal proteins were found to be stable in soil extract tested up to 9 days when stored at 4 degrees C.


Asunto(s)
Cromatografía Liquida/métodos , Defensinas , Proteínas de Plantas/análisis , Suelo/análisis , Antifúngicos/análisis , Antifúngicos/química , Proteínas de Plantas/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...