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Home range and nesting habitat were studied in two sympatric pelomedusid terrapins (Pelusios niger and Pelusios castaneus) from two study areas in the Niger Delta (Nigeria, West Africa), one with pristine habitat conditions and one which was polluted by a oil spill event some years before. Seventy-seven individuals (38 P. niger and 39 P. castaneus) were radiotracked, each for more than 60 days, and their home range was calculated by the minimum convex polygon method, with 95% of the point locations per individual. The mean home range size of females was significantly larger in the polluted area than in the pristine area in both P. niger and P. castaneus, and the mean home range size of female P. niger was significantly larger than that of female P. castaneus in the polluted area, but not in the pristine area. The mean home range size of males was significantly larger in the polluted area than in the pristine area in P. niger but not in P. castaneus, and the mean home range size of male P. niger was significantly larger than that of male P. castaneus in the polluted area but not in the pristine area. Radiotracked females of both species showed a clear preference for nesting sites situated along ponds and not along the banks of the river, on sandy soil, often with abundant vegetation around. Some females of both species deposited their eggs at greater distances from water bodies in the polluted area than in the pristine area. The comparative evidence of these patterns indicates consistent responses of the two species to the altered habitat, which further supports the general hypothesis that habitat pollution has seriously affected the ecological strategies of these terrapin species. [ABSTRACT FROM AUTHOR]

Deals with the aspects of the ecology of a population of Causus maculatus from southern Nigeria. Examination of the population structure, food habits and reproductive ecology of a free-living population from a swamp rainforest-plantation mosaic area; Food items found in the stomach of the viperids; Prefered prey of Causus maculatus.

Electrophoretic microfluidic paper-based analytical devices (e-µPADs) are promising for low-cost and portable technologies, but quantitative detection remains challenging. In this study, we develop a paper-based isotachophoretic preconcentration and separation method for the herbicide glyphosate as a model analyte. The device, consisting of two electrode chambers filled with leading and terminating electrolytes and a nitrocellulose strip as the separation carrier, was illuminated by a flat light source and operated with a voltage supply of 400 V. Detection was accomplished using a simple camera. Colorimetric detection was optimized through competitive complexation between glyphosate, copper ions, and pyrocatechol violet as a dye. The buffer system was optimized using simulations, (i) ensuring the pH was optimal for the demetallation of the blue pyrocatechol violet-copper complex [PV] to the yellow free dye and (ii) ensuring the electrophoretic migration of glyphosate into the slower [PV] for the colorimetric reaction. A new data evaluation method is presented, analyzing the RGB channel intensities. The linear range was between 0.8 and 25 µM, with a LOD of approximately 0.8 µM. The ITP separation preconcentrated glyphosate by a factor of 820 in numerical simulations. The method may be applied to control glyphosate formulations, especially in developing countries where herbicide sales and applications are poorly regulated., (© 2024. The Author(s).)

Capillary electrophoresis-mass spectrometry often lacks sufficient limits of detection for trace substances in the environment due to its low loadability. To overcome this problem, we conducted a feasibility study for column-coupling isotachophoresis to capillary electrophoresis-mass spectrometry. The first dimension isotachophoresis preconcentrated the analytes. The column-coupling of both dimensions was achieved by a hybrid capillary microfluidic chip setup. Reliable analyte transfer by voltage switching was enabled by an in-chip capacitively coupled contactless conductivity detector placed around the channel of the common section between two T-shaped crossings in the chip connecting both dimensions. This eliminated the need to calculate the moment of analyte transfer. A commercial capillary electrophoresis-mass spectrometry instrument with easily installable adaptations operated the setup. Prior to coupling isotachophoresis with capillary zone electrophoresis-mass spectrometry, both dimensions were optimized individually by simulations and verified experimentally. Both dimensions were able to stack/separate all degradation products of glyphosate, the most important herbicide applied worldwide. The first dimension isotachophoresis also removed phosphate, which is a critical matrix component in many environmental samples. Enrichment and separation of glyphosate and its main degradation product aminomethylphosphonic acid by the two-dimensional setup provided an excellent limit of detection of 150 pM (25 ng/L) for glyphosate., (© 2022 The Authors. Journal of Separation Science published by Wiley-VCH GmbH.)