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11.
Athlua B. Attygalle Karla Jessen Hans-Jürgen Bestmann Alfred Buschinger Ulrich Maschwitz 《Chemoecology》1996,7(1):8-12
Summary Gas chromatographic analyses of volatizable material from gaster intersegmental complex glands ofP. tridentata revealed the presence of linoleic acid, palmitic acid, methyl oleate, and several long-chain hydrocarbons as major constituents, which form an oily fluid mixture. The nest relocation communication ofP. tridentata is tandem running. Tandem following is mediated by pheromones as demonstrated by dummy experiments with isolated gasters and thoraces and with glass balls. The secretions of all gaster complex glands, as well as hind gut contents and metapleural gland secretions, were unable to evoke tandem following. Morphology and position of the glands, lack of pheromonal function, oily properties, low volatility, and lack of antibiotic effects of these secretions strongly suggest a function as lubricants for the ants' gastral segments. 相似文献
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Juan Salvador Chin-Pampillo Mario Masís-Mor Karla Ruiz-HidalgoElizabeth Carazo-Rojas Carlos E. Rodríguez-Rodríguez 《环境科学学报(英文版)》2016,28(8):182-189
Biomixtures constitute the biologically active part of biopurification systems(BPS), which are used to treat pesticide-containing wastewater. The aim of this work was to determine whether co-application of chlorpyrifos(CLP) affects the removal of carbofuran(CFN)(both insecticide/nematicides) in a coconut fiber–compost–soil biomixture(FCS biomixture), after aging or previous exposure to CFN. Removal of CFN and two of its transformation products(3-hydroxycarbofuran and 3-ketocarbofuran) was enhanced in pre-exposed biomixtures in comparison to aged biomixtures. The co-application of CLP did not affect CFN removal, which suggests that CLP does not inhibit microbial populations in charge of CFN transformation.Contrary to the removal behavior, mineralization of radiolabeled14C-pesticides showed higher mineralization rates of CFN in aged biomixtures(with respect to freshly prepared or pre-exposed biomixtures). In the case of CLP, mineralization was favored in freshly prepared biomixtures, which could be ascribed to high sorption during aging and microbial inhibition by CFN in pre-exposure. Regardless of removal and mineralization results, toxicological assays revealed a steep decrease in the acute toxicity of the matrix on the microcrustacean Daphnia magna(over 97%) after 8 days of treatment of individual pesticides or the mixture CFN/CLP.Results suggest that FCS biomixtures are suitable to be used in BPS for the treatment of wastewater in fields where both pesticides are employed. 相似文献
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Locher-Krause Karla E. Lautenbach Sven Volk Martin 《Regional Environmental Change》2017,17(8):2477-2493
Regional Environmental Change - The understanding of how ecosystem services are distributed across the landscape and their change over time provides key information to manage multi-functional... 相似文献
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Indra?Elena?C.?EscobarEmail author Vilma?M.?Santos Danielle?Karla?A.?da?Silva Marcelo?F.?Fernandes Uided?Maaze?T.?Cavalcante Leonor?C.?Maia 《Environmental management》2015,55(6):1433-1445
The aim of this study was to describe the impact of re-vegetation on the restoration of microbial community structure and soil microbiological properties in sand dunes that had been affected by mining activity. Soil samples were collected during the dry and rainy seasons from a chronosequence (1, 9, 21 years) of re-vegetated dunes using a single preserved dune as a reference. The composition of the fatty acid methyl esters and soil microbial properties were evaluated. The results showed that the changes in microbial community structure were related to seasonal variations: biomarkers of Gram-positive bacteria were higher than Gram-negative bacteria during the dry season, showing that this group of organisms is more tolerant to these stressful conditions. The microbial community structure in the natural dune was less affected by seasonal variation compared to the re-vegetated areas, whereas the opposite was observed for microbiological properties. Thus, in general, the proportion of saprobic fungi was higher in the natural dune, whereas Gram-negative bacteria were proportionally more common in the younger areas. Although over time the re-vegetation allows the recovery of the microbial community and the soil functions, these communities and functions are different from those found in the undisturbed areas. 相似文献
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Glenda Dias Karla S. C. Yotoko Luiz F. Gomes José Lino-Neto 《Die Naturwissenschaften》2012,99(9):773-777
Several species of Tenebrionidae are stored-grain pests. Since they belong to a specious family, the systematics of these beetles is still in doubt. In insects, spermatogenesis and the spermatozoa exhibit great diversity, and are therefore commonly used in phylogenetic and taxonomic analyses. During the spermatogenetic process in these organisms, the cells originating from a single spermatogonium develop synchronically in groups referred to as cysts. At the end of this process, there is usually only one sperm bundle per cyst, with all the cells in the same orientation. This paper details the spermiogenesis of the tenebrionid beetles Tenebrio molitor, Zophobas confusa, Tribolium castaneum and Palembus dermestoides using whole mount and histological sections of the cysts. In these species, spermatogenesis is similar to that which occurs in most insects. However, during spermiogenesis, the nuclei of the spermatids migrate to two opposite regions at the periphery of the cyst, leading to the uncommon formation of two bundles of spermatozoa per cyst. This feature is possibly an apomorphy for Tenebrionidae. 相似文献
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Stephanie Mesías Monsalve Leonardo Martínez Karla Yohannessen Vásquez Sergio Alvarado Orellana José Klarián Vergara Miguel Martín Mateo Rogelio Costilla Salazar Mauricio Fuentes Alburquenque Dante D. Cáceres Lillo 《Environmental geochemistry and health》2018,40(3):1077-1091
Air quality in schools is an important public health issue because children spend a considerable part of their daily life in classrooms. Particulate size and chemical composition has been associated with negative health effects. We studied levels of trace element concentrations in fine particulate matter (PM2.5) in indoor versus outdoor school settings from six schools in Chañaral, a coastal city with a beach severely polluted with mine tailings. Concentrations of trace elements were measured on two consecutive days during the summer and winter of 2012 and 2013 and determined using X-ray fluorescence. Source apportionment and element enrichment were measured using principal components analysis and enrichment factors. Trace elements were higher in indoor school spaces, especially in classrooms compared with outdoor environments. The most abundant elements were Na, Cl, S, Ca, Fe, K, Mn, Ti, and Si, associated with earth’s crust. Conversely, an extremely high enrichment factor was determined for Cu, Zn, Ni and Cr; heavy metals associated with systemic and carcinogenic risk effects, whose probably origin sources are industrial and mining activities. These results suggest that the main source of trace elements in PM2.5 from these school microenvironments is a mixture of dust contaminated with mine tailings and marine aerosols. Policymakers should prioritize environmental management changes to minimize further environmental damage and its direct impact on the health of children exposed. 相似文献
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Stephen G. Perz Jeffrey Hoelle Karla Rocha Veronica Passos Flavia Leite Julia Cortes 《Journal of Land Use Science》2017,12(4):231-251
In the complex causation behind land change, dependent causation can play a central role. A case in point concerns land tenure diversity, where contrasting use rules for different lands may affect the impacts of other drivers on land use outcomes. We therefore evaluate the evolutionary theory of land rights (ETLR), which assumes homogeneous private property rights, in order to test for dependent causation due to distinct use rules among various types of private lands. In the present analysis, we focus on whether land tenure type modifies the effects of highway infrastructure on key outcomes highlighted in the ETLR framework. We take up the case of rural settlements along the Inter-Oceanic Highway in the eastern part of the Brazilian state of Acre, where there is considerable land tenure diversity. Findings from multivariate models for land titling, the castanha nut harvest, and cattle pasture all indicate that the effects of infrastructure depend on land tenure type. These results confirm the importance of dependent causation behind land use and bear implications for theory on land change, infrastructure impacts, and land system science. 相似文献
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Saulo R. Freitas Karla M. Longo Maria A. F. Silva Dias Pedro L. Silva Dias Robert Chatfield Elaine Prins Paulo Artaxo Georg A. Grell Fernando S. Recuero 《Environmental Fluid Mechanics》2005,5(1-2):135-167
The atmospheric transport of biomass burning emissions in the South American and African continents is being monitored annually using a numerical simulation of air mass motions; we use a tracer transport capability developed within RAMS (Regional Atmospheric Modeling System) coupled to an emission model. Mass conservation equations are solved for carbon monoxide (CO) and particulate material (PM2.5). Source emissions of trace gases and particles associated with biomass burning activities in tropical forest, savanna and pasture have been parameterized and introduced into the model. The sources are distributed spatially and temporally and assimilated daily using the biomass burning locations detected by remote sensing. Advection effects (at grid scale) and turbulent transport (at sub-grid scale) are provided by the RAMS parameterizations. A sub-grid transport parameterization associated with moist deep and shallow convection, not explicitly resolved by the model due to its low spatial resolution, has also been introduced. Sinks associated with the process of wet and dry removal of aerosol particles and chemical transformation of gases are parameterized and introduced in the mass conservation equation. An operational system has been implemented which produces daily 48-h numerical simulations (including 24-h forecasts) of CO and PM2.5, in addition to traditional meteorological fields. The good prediction skills of the model are demonstrated by comparisons with time series of PM2.5 measured at the surface. 相似文献