145 research outputs found
Loss of ion homeostasis is not the cause of chill coma or impaired dispersal in false codling moth Thaumatotibia leucotreta (Lepidoptera: Tortricidae)
Dispersal is a central requirement of a successful sterile insect release programme, but field-released false codling moth (FCM) typically suffer from poor dispersal ability, especially at low ambient temperatures. Here we test the hypothesis that poor activity and dispersal in FCM is caused by delayed or perturbed recovery of ion and/or water homeostasis after chilling for handling and transport prior to field release. Hemolymph and flight muscle were collected from two treatment groups at three time points that targeted thermal conditions above and below the chill coma induction threshold of ~ 6 °C: 1) control moths kept at 25 °C, 2) moths exposed to 3 °C or 9 °C for 4 h, and 3) moths allowed to recover at 25 °C for 24 h after exposure to either 3 °C or 9 °C. We measured concentrations of Na+, K+ and Mg2+ in the hemolymph and muscle collected at each time point. Exposure to a chill-coma inducing temperature had little effect overall on ion balance in the hemolymph and flight muscle of false codling moth, but hemolymph [Na+] decreased from 10.4 ± 0.4 mM to 6.9 ± 0.7 mM as moths were chilled to 3 °C and then increased to 10.4 ± 0.9 mM after the 24 h recovery period. In the 9 °C cooling treatment, [K+] increased from 8.2 ± 0.5 mM during chilling to 14.1 ± 1.9 mM after the 24 h recovery period. No changes were seen in equilibrium potentials in either of the ions measured. Thus, we did not find evidence that water and ion homeostasis are lost by the moths in chill coma and conclude that reduced dispersal in field-released moths is not direct a consequence of the costs of re-establishment of homeostasis
Three new Drosophilidae species records for South Africa
CITATION: De Araujo, L. I., Karsten, M. & Terblanche, J. S. 2020. Three new Drosophilidae species records for South Africa. Bothalia, 49(1), a2429, doi:10.4102/abc.v49i1.2429.The original publication is available at https://journals.abcjournal.aosis.co.za/index.php/abcBackground: Data on the current species diversity from the Drosophilidae family in South Africa is limited or outdated. Objectives: Using haphazard, limited trapping for a different study, we serendipitously report on and document Drosophilidae species in two distinct regions (representing a sub-tropical and a Mediterranean climate region) of South Africa. Method: Drosophilidae were trapped using mixed fruit and mushroom traps around urban areas in two climatically distinct regions of South Africa. The flies were identified using standard barcoding ( Cytochrome c Oxidase Subunit I [COI] gene sequence) and, in some cases, additional identification from a taxonomical expert using morphological traits. Species were checked against literature, online resources and a previously compiled library of South African Drosophilidae to determine whether they were new records. Results: Thirteen species were readily collected and identified. Of these, three species (Drosophila ananassae, Drosophila nasuta and Zaprionus taronus) have not been reported previously in South Africa. One of the species (Z. taronus) was captured in a home garden, while the other two species were captured in an urban-agricultural region with a sub-tropical climate. Conclusions: From our limited serendipitous sampling, three new species records have been found in sub-tropical climates in South Africa. With more comprehensive, systematic sampling, a better understanding of the South African Drosophilidae composition, and thus the detection of alien or invasive species, can be pursued. Baseline data for understanding spatio-temporal patterns of native biodiversity, or for informing management actions in the case of alien or invasive species, are currently inadequate for this group in the region.Publisher's versio
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Using 3-D Modeling to Improve the Efficiency for Removing Plutonium Processing Equiment From Gloveboxes at the Plutonium Finishang Plant
The Plutonium Finishing Plant at the Department of Energy's Hanford Site in southeastern Washington State began operations in 1949 to process plutonium and plutonium products. Its primary mission was to produce plutonium metal, fabricate weapons parts, and stabilize reactive materials. These operations, and subsequent activities, were performed in production lines, consisting primarily of hundreds of gloveboxes. Over the years, these gloveboxes and attendant processes have been continuously modified. The plant is currently inactive and Fluor Hanford has been tasked with cleaning out contaminated equipment and gloveboxes from the facility so it can be demolished in the near future. Approximately 100 gloveboxes at PFP have been cleaned out in the past four years and about 90 gloveboxes remain to be cleaned out. Because specific commitment dates for this work have been established with the State of Washington and other entities, it is important to adopt work practices that increase the safety and speed of this effort. The most recent work practice to be adopted by Fluor Hanford D and D workers is the use of 3-D models to make the process of cleaning out the radioactive gloveboxes more efficient. The use of 3-D models has significantly improved the work-planning process by giving workers a clear image of glovebox construction and composition, which in turn is used to determine cleanout methods and work sequences. The 3-D visual products also enhance safety by enabling workers to more easily identify hazards and implement controls. Further, the ability to identify and target the removal of radiological material early in the D and D process provides substantial dose reduction for the workers
Evaluation intégrée des mesures agro-environnementales territorialisées à enjeu "qualité des eaux" sur la période 2007 à 2011 : le projet MAEVEAU
The MAEVEAU project has developed an approach for an integrated assessment of effectiveness of regionalized Agro-Environmental Measures (MAET) intended to preserve water quality in relation to pesticides. This approach investigates the concept of efficiency through a triple analysis: the impact (net effects), the environmental cost-effectiveness and the role of organizational factors in the contracting process. The impact is assessed by a quasi-experimental approach by counterfactuals and examines adaptation of the matching method to the regionalized MAET. Cost-effectiveness analysis is based on integrated modeling spatially distributed coupling the agro-hydrological SWAT model, pesticides pressure indicators and a bio-economic model optimizing gross margin. The effectiveness of organizational factors focuses on transaction costs, the role of collective action and preferences for alternative contracts.La recherche conduite dans le projet MAEVEAU a développé une démarche d'évaluation intégrée de l'efficacité des Mesures Agro-Environnementales Territorialisées (MAET) à enjeu préservation de la qualité de l'eau vis-à-vis des pesticides sur la période 2007 à 2011. La question scientifique traite le concept d'efficacité de la politique en s'appuyant sur une triangulation des approches: une évaluation de l'impact (c'est-à-dire des effets propres de la politique), une évaluation coût-efficacité environnementale et une évaluation du rôle des facteurs organisationnels dans le processus d'adhésion. L'impact est évalué par une approche quasi-expérimentale par contrefactuel et questionne l'adaptation de la méthode du matching à la territorialisation des MAET. L'analyse coût-efficacité s'appuie sur une modélisation intégrée spatialisée couplant modèle agro-hydrologique, indicateurs pesticides spatialisés et optimisation économique des marges brutes. L'efficacité des facteurs organisationnels s'est intéressée aux coûts de transaction, au rôle de l'action collective et aux préférences pour des contrats alternatifs
WORK PRECARIOUSNESS: ERGONOMIC RISKS TO OPERATORS OF MACHINES ADAPTED FOR FOREST HARVESTING
Avaliação das condições de segurança no trabalho nos setores florestais de uma Instituição Federal de Ensino Superior
Conformidade dos comandos de operação de tratores agrícolas nacionais com a norma NBR ISO 4253
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