Habitat use by demersal nekton on the continental shelf in the Benguela ecosystem, southern Africa

Videotapes collected by the research submersible Jago in the Benguela ecosystem during spring 1997 were analyzed to determine demersal nekton assemblage composition, fish behavior, and microscale habitat association, and habitat selection. Demersal fish assemblage diversity was generally low, and their composition was a function of substratum type. Individual species showed an often marked association with either rocky or soft substrata (or both), and a strong or weak selection for the associated biota. Soles and dragonets actively selected areas of bioactive soft substrata, to which they are behaviorally and morphologically adapted. False jacopever were associated with crevices in areas of high-relief rocky substrata. Kingklip are piscivorous and were largely confined to holes at the base of rocks and favored areas without a conspicuous epifauna. Juvenile hake and gobies avoided extremely rocky areas and were largely indifferent to the presence of benthic invertebrates—behavior that is consistent with their planktonic diets. These results represent the first direct observations of demersal nekton in the region and are important because they allow better interpretations of the results of trawl studies

Advancing animal tuberculosis surveillance using culture-independent long-read whole-genome sequencing

Acknowledgments Some of the figures (Figures 4–6 and Supplementary Material S1) were generated using BioRender and draw.io, respectively. Funding The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This research was funded by the Wellcome Foundation (grant #222941/Z/21/Z), the South African Medical Research Council, American Association of Zoo Veterinarians Wild Animal Health Fund [S005651 and S007355], the National Research Foundation South African Research Chair Initiative [grant #86949], and MHM was supported by Wellcome Trust (grant #216634/Z/19/Z). AGL is supported by the EDCTP TESA III network (CSA2020NoE-3104).Peer reviewedPublisher PD

Temperature Sensitivity of Silicon Cantilevers with the Pull-in Instability Method

AbstractIn this paper the temperature effects on [110] Silicon cantilevers is analyzed and measured in the range of 25 -100 °C. The quasi-static electrostatic pull-in instability method developed recently for ultra-thin cantilevers [“Characterizing Size-dependent Effective Elastic Modulus of Silicon Nanocantilevers Using Electrostatic Pull-in Instability”, Applied Physics Letters, Vol. 94(22), p. 221903, 2009] is employed to measure the temperature sensitivity of ultra-thin cantilevers. A temperature sensitivity of 81.3 °C/V is obtained. The temperature sensitivity is mostly due to the temperature dependence of the effective Young’s Modulus of silicon. It is shown that changes in geometrical dimensions due to the change in temperature can be neglected. The changes in the effective Young’s Modulus due to the changes in temperature are extracted using an electromechanical-coupled system. The pull-in method showed substantial advantages over other methods used for the study of the thermal effects on micron and sub-micron structures. The results demonstrate a new concept for a temperature sensor with ultra high sensitivity

Some considerations of effects-induced errors in resonant cantilevers with the laser deflection method

Micro/nano resonant cantilevers with a laser deflection readout have been very popular in sensing applications over the past years. Despite the popularity, however, most of the research has been devoted to increasing the sensitivity, and very little attention has been focused on effects-induced errors. Among these effects, the surface effects and the so-called readout back-action are the two most influential causes of errors. In this paper, we investigate (1) the influence of the surface effects such as water adsorption, gas adsorption, and generally surface contaminations, and (2) the effect of the laser deflection detection, including power and positions of the laser, on the resonance frequency of silicon cantilevers. Our results show that both the surface contaminations and the laser back-action effects can significantly change the resonant response of the cantilevers. We conclude that the effects have to be taken into account, particularly in the case of ultra high sensitivity cantilevers.Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin