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821.
The current status of the oak and oak-pine forests in the Sierra de La Laguna range of the Baja California peninsula is examined from four perspectives: (1) the structural analysis of the woodlands; (2) the natural regeneration of hurricane windfall clearings and its effect on the oak-pine community; (3) the density, mortality, size, and commercial potential of the only pine species Pinus lagunae; and (4) the possible destruction of this endemic species by attack from moths. These factors were evaluated to make recommendations regarding the management and/or commercialization of the forest resources of this proposed Biosphere Reserve. Results show that the oak woodlands occurring at low elevations contain many tropical plants from the tropical dry forest that surrounds these woodlands, and that the tropical elements decrease at higher altitudes. In forest gaps, oaks were more abundant than pines. Gaps contained a lower diversity of perennial plants than mature oak-pine forest. P. lagunae has a high adult mortality, which can be attributed to the joint effect of fire and insect attack. Results indicate that the forest in this region does not have timber-yielding potential because of the small area it covers and because of the low tree diameters and volume, which are insufficient to carry out a continuous and income-producing extraction of the pine resource of Baja California Sur. Finally, options for management are discussed and future studies are proposed to determine the life cycle and extent of the moth populations. 相似文献
822.
Emilio D’Ugo Stefania Marcheggiani Ilaria Fioramonti Roberto Giuseppetti Roberto Spurio Karim Helmi Delphine Guillebault Linda K. Medlin Ivan Simeonovski Bas Boots Ulrich Breitenbach Latife Koker Meric Albay Laura Mancini 《Food and environmental virology》2016,8(3):206-214
The transmission of water-borne pathogens typically occurs by a faecal–oral route, through inhalation of aerosols, or by direct or indirect contact with contaminated water. Previous molecular-based studies have identified viral particles of zoonotic and human nature in surface waters. Contaminated water can lead to human health issues, and the development of rapid methods for the detection of pathogenic microorganisms is a valuable tool for the prevention of their spread. The aims of this work were to determine the presence and identity of representative human pathogenic enteric viruses in water samples from six European countries by quantitative polymerase chain reaction (q-PCR) and to develop two quantitative PCR methods for Adenovirus 41 and Mammalian Orthoreoviruses. A 2-year survey showed that Norovirus, Mammalian Orthoreovirus and Adenoviruses were the most frequently identified enteric viruses in the sampled surface waters. Although it was not possible to establish viability and infectivity of the viruses considered, the detectable presence of pathogenic viruses may represent a potential risk for human health. The methodology developed may aid in rapid detection of these pathogens for monitoring quality of surface waters. 相似文献
823.
Laura Tozer 《Journal of Environmental Planning and Management》2018,61(1):176-194
This paper clarifies the competing discourses of sustainability and climate change and examines the manifestation of these discourses in local government planning. Despite the increasingly significant role of sustainability and climate change response in urban governance, it is unclear whether local governments are constructing different discourses that may result in conflicting approaches to policy-making. Using a governmentality approach, this paper dissects the contents of 15 Canadian local governments’ sustainability plans. The findings show that there are synergies and tensions between discourses of sustainability and climate change. Both share discursive space and shape local governance rationalities, though climate change response logics are not necessarily highlighted even where the action could result in greenhouse gas (GHG) emission reductions. In some cases, existing GHG intensive practices are being rebranded as ‘sustainable’. This suggests a tension between discourses of sustainability and climate change that may complicate attempts to address climate change through local sustainability planning. 相似文献
824.
We present reports of sightings of living and stranded specimens of Rhizostoma luteum on the Atlantic coast of Morocco and along the south shore of the Iberian Peninsula in June–July 2012 and in January–February 2013. During summer 2012 and following the dominant currents, the jellyfish first appeared in the Gulf of Cadiz west of the Strait of Gibraltar. Subsequently, seven additional sightings were reported east of the Strait, in the Alboran Sea. In winter 2013, another event of stranded individuals of this species occurred in the Gulf of Cadiz. A phylogenetic analysis performed on the mitochondrial cytochrome c oxidase I (COI) gene sequence in specimens from both stranding events confirmed the morphological classification, ratifying that R. luteum differs from Rhizostoma octopus and Rhizostoma pulmo. This study records the presence of this species for the first time in 60 years. 相似文献
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826.
Michelle E. H. Helinski Laura C. Harrington 《Behavioral ecology and sociobiology》2012,66(8):1131-1140
Sexual harassment studies in insects suggest that females can incur several kinds of costs from male harassment and mating. Here, we examined direct and indirect costs of male harassment on components of female fitness in the predominantly monandrous mosquito Aedes aegypti. To disentangle the costs of harassment versus the costs of mating, we held females at a low or high density with males whose claspers were modified to prevent insemination and compared these to females held with normal males and to those held with females or alone. A reduced longevity was observed when females were held under high-density conditions with males or females, regardless if male claspers had been modified. There was no consistent effect of harassment on female fecundity. Net reproductive rate (R 0) was higher in females held at low density with normal males compared to females held with males in the other treatments, even though only a small number of females showed direct evidence of remating. Indirect costs and benefits that were not due to harassment alone were observed. Daughters of females held with normal males at high density had reduced longevity compared to daughters from females held without conspecifics. However, their fitness (R 0) was higher compared to females in all other treatments. Overall, our results indicate that A. aegypti females do not suffer a fitness cost from harassment of males when kept at moderate densities, and they suggest the potential for benefits obtained from ejaculate components. 相似文献
827.
Thousands of unaddressed brownfields sites remain in our nation's poorest urban neighborhoods, despite almost two decades of federal and state attention to cleaning up and redeveloping these sites. Many of these neighborhoods have active community‐based organizations (CBOs) whose mission it is to improve the quality of life for disadvantaged residents whose lives are negatively impacted by these decaying, contaminated properties. Under the assumption that greater involvement of community organizations, specifically community development corporations (CDCs), would help to spur increased attention to and progress toward remediating these sites, we developed a pilot technical assistance program to build CDC capacity to facilitate or actually undertake brownfields redevelopment projects. This article describes the process of development and the program's content and structure and evaluates the program based on a pilot test conducted with two CDCs in a major US city. Future prospects for expansion of this type of program are discussed. © 2011 Wiley Periodicals, Inc. 相似文献
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830.
Aline Brum Geovana Dotta Katina Roumbedakis Eduardo L. T. Gonçalves Laura P. Garcia Patrícia Garcia 《Journal of environmental science and health. Part. B》2013,48(3):169-175
This study evaluated the influence of the clomazone herbicide (2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone) contamination on the hematological parameters and histological changes in gills and liver of silver catfish (Rhamdia quelen) from Madre River, Santa Catarina State, Southern Brazil. Fish were collected between March 2010 and January 2012 at two different sites of the Madre River, one site receiving residual water (contaminated site) from rice culture (n = 49) and another that do not receive residual water (reference site) (n = 48). The herbicide clomazone analysis detected 3.40 ± 1.70 μg/L in the contaminated site and 1.1 ± 0.33 μg/L in the reference site. Fish from contaminated site showed increased (P < 0.05) number of monocytes suggesting the possible defense response as a result of chronic exposure to clomazone. On the other hand, no difference was found in the hematocrit percentage, red blood cell count, total thrombocyte number, white blood cell count, lymphocytes, and neutrophils number. Fish from both sites showed histopathological changes in gills and liver, possibly caused by chronic exposure to contamination. The influence of herbicide sub doses on fish health is also discussed. 相似文献