The half-lives of biological activity of some pesticides in water

In the absence of analytical methods, the half-lives of biological activity of pesticides can be estimated by bioassays. To determine the half-lives of biological acivity of pesticides to fish, static bioassays were conducted in the laboratory with ten different formulations of pesticides using Labeo rohita as a bio-indicator. The half-lives of biological activity for ten different pesticides in soft water at pH 7.5 and 27°C, ranged from 4.6 days to 11.8 days. The half-life of biological activity of Sumithion 50% EC was only 4.6 days. In contrast, Dimecron 50% EC degraded very slowly and its half-life of biological activity on L. rohita was about 11.8 days. Sumithion 50% EC, Padan 50% SP, EPN 45% EC, Diazinon 40% EC and Diazinon 10 G degraded in less than five to seven days indicating that these pesticides are desirable for rice-fish culture. Contamination by pesticides with long-term residual toxicity in waters may eventually cause high levels of fish mortality

Tracking a table tennis ball for umpiring purposes

This study investigates tracking a table-tennis ball rapidly from video captured using low-cost equipment for umpiring purposes. A number of highly efficient algorithms have been developed for this purpose. The proposed system was tested using sequences capture from real match scenes. The preliminary results of experiments show that accurate and rapid tracking can be achieved even under challenging conditions, including occlusion and colour merging. This work can contribute to the development of an automatic umpiring system and also has the potential to provide amateur users open access to a detection tool for fast-moving, small, round objects

Collaboration for diagnosis of Xanthomonas citri pv. mangiferaeindicae causing mango bacterial canker on Mangifera indica in Myanmar : [P2-10]

During 2006-2008, mango disease survey training for pest Iist development was supported under the ASEAN Australia Development Co-operation Program (AADCP) Program Stream: Strengthening ASEAN Plant Health Capacity Project (1). The project involved regional training workshops and practical experience in surveying and disease diagnostics in selected ASEAN countries, in partnership with Australian mango pest and disease specialists. The surveying also provided an opportunity for extending collaboration with CIRAD and for strengthening CIRAD-ASEAN links, when specialist expertise in bacterial disease diagnostics was required. Bacterial canker of mango (or bacterial black spot) caused by #Xanthomonas citri pv. Mangiferaeindicae# (2) is a disease of economic importance in tropical and subtropical producing areas. #X. citri pv. Mangiferaeindicae# can cause severe infection in a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Suspected leaf lesions of bacterial canker were collected from mango nursery stock cv. Yin Kwe at a nursery in Yangon, Myanmar during March 2007. Sub-samples of representative accessions were dispatched by air-courier to 2CIRAD UMR PVBMT, La Réunion, with additional reference material retained in the plant disease herbarium of'PPD. In tests at CIRAD UMR PVBMT2, nonpigmented Xanthomonas-like bacterial colonies were isolated on KC and NCTM3 semiselective agar media (4,7). Amplified fragment length polymorphism analysis was performed on three isolates from Myanmar and additional reference isolates of xanthomonads originating from Anacardiaceae (#X. citri pv. Anacardii#, #X. citri pv. Mangiferaeindicae#, #X. axonopodis pv. Spondiae#, and #X. translucens# strains from pistachio) (2, 4). On the basis of multidimensional scaling (2), the Myanmar isolates were identified as #X. citri pv. Mangiferaeindicae# and were most closely related to group B strains that were isolated from mango in India and Eastern Asia (5). Mango cv. Maison Rouge leaves, inoculated as previously reported (3) with the Myanmar isolates, showed typical symptoms of bacterial canker 1 week after inoculation. One month after inoculation, mean #X. citri pv. Mangiferaeindicae# population sizes ranging from 5 x 106 to 8 x 106 CFU per lesion were recovered from leaf lesions, typical of a compatible interaction (3). #Mangifera indica# L. probably evolved in the area that includes northwestern Myanmar (6) and to our knowledge, this is the first confirmed detection of #X. citri pv. Mangiferaeindicae# from Myanmar. Further surveys and strain collection will be necessary to evaluate its geographic distribution and prevalence in the country (4). The diagnosis and confirmation of bacterial spot on mango from Myanmar (4) has assisted in the development of Myanmar's mango pest list, and enabled Myanmar partners to gain experience in international collaboration in plant disease specimen dispatch and diagnostics. (Résumé d'auteur

Patterns and Rates of Land Use Land Cover Change: A Case Study of Ambos Nogales (Arizona and Sonora), 1985-2004

Abstract The continued expansion of the paired U.S.–Mexican border cities of Ambos Nogales presents many environmental management and urban planning challenges. This study focuses on a comparative study of spatial patterns and rates of land-use and land-cover change, in relation to land degradation, deforestation, and urban growth over different time periods. Based on historical data the study suggests that both cities have experi- enced high land degradation; however, land on the Arizona-side has been more stable and less degraded. However, there were more severely degraded areas found in Nogales, Arizona, than in Nogales, Sonora. The delineation of land use change and the severity of land degradation provide important information to planners about areas that should be targeted for development and other areas that require restoration to natural settings. Keywords: Nogales, land use land cover, urban growth, land degradation Resumen La expansión continua de las ciudades gemelas de Ambos Nogales (USA-Mexico) presenta muchos desafíos de planificación urbana y manejo ambiental. Este estudio se concentra en un análisis comparativo de los patrones espaciales y velocidad de cambios de uso del suelo con relación a la degradación del terreno, deforestación, y crecimiento urbano durante distintos períodos de tiempo. Basado en datos históricos el estudio sugiere que ambas ciudades han experimentado alta degradación de tierra, pero la tierra en el lado de Arizona ha sido más estable y menos degradada. Sin embargo, en Nogales Arizona, habían áreas severamente más degradadas que en Nogales, Sonora. Palabras clave: Nogales, crecimiento urbano, uso de suelo, degradación de tierra