957 resultados para Site Selection
Resumo:
There have been over 3000 bridge weigh-in-motion (B-WIM) installations in 25 countries worldwide, this has led vast improvements in post processing of B-WIM systems since its introduction in the 1970’s. Existing systems are based on electrical resistance strain gauges which can be prohibitive in achieving data for long term monitoring of rural bridges due to power consumption. This paper introduces a new low-power B-WIM system using fibre optic sensors (FOS). The system consisted of a series of FOS which were attached to the soffit of an existing integral bridge with a single span of 19m. The site selection criteria and full installation process has been detailed in the paper. A method of calibration was adopted using live traffic at the bridge site and based on this calibration the accuracy of the system was determined. New methods of axle detection for B-WIM were investigated and verified in the field.
Resumo:
Oyster populations around the world have seen catastrophic decline which has been largely attributed to overexploitation, disease and pollution. While considerable effort and resources have been implemented into restoring these important environmental engineers, the success of oyster populations is often limited by poor understanding of site-specific dispersal patterns of propagules. Water-borne transport is a key factor controlling or regulating the dispersal of the larval stage of benthic marine invertebrates which have limited mobility. The distribution of the native oyster Ostrea edulis in Strangford Lough, Northern Ireland, together with their densities and population structure at subtidal and intertidal sites has been documented at irregular intervals between 1997 and 2013. This paper revisits this historical data and considers whether different prevailing environmental conditions can be used to explain the distribution, densities and population structure of O. edulis in Strangford Lough. The approach adopted involved comparing predictive 2D hydrodynamic models coupled with particle tracking to simulate the dispersal of oyster larvae with historical and recent field records of the distribution of both subtidal and intertidal, populations since 1995. Results from the models support the hypothesis that commercial stocks of O. edulis introduced into Strangford Lough in the 1990s resulted in the re-establishment of wild populations of oysters in the Northern Basin which in turn provided a potential source of propagules for subtidal populations. These results highlight that strategic site selection (while inadvertent in the case of the introduced population in 1995) for the re-introduction of important shellfish species can significantly accelerate their recovery and restoration.
Resumo:
Tese de Doutoramento, Geografia (Ordenamento do Território), 25 de Novembro de 2013, Universidade dos Açores.
Resumo:
Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.
Resumo:
Dissertation presented to obtain the Ph.D degree in Molecular Biology
Resumo:
The purpose ofthis study was to explore the process oftherapeutic riding as an experiential and holistic approach to learning and recovery for people with disabilities as perceived by the providers oftherapeutic riding. To enhance the connection between theory and practice and to suggest future research, the researcher endeavoured to develop a theory that contributed to the knowledge base oftherapeutic riding, animal-assisted therapy and education, experiential education, and experiential therapy in addition to contributing to connections among them. This topic was investigated because ofthe lack ofresearch about the process of therapeutic riding, particularly from learning and a recovery perspective. Few studies have addressed how therapeutic riding outcomes are achieved or how the therapeutic riding process actually works. This study was identified as grounded theory using qualitative data through interviews and narrative reflections with therapeutic riding providers, a researcher's journal, field notes, and written documents. Grounded theory analysis was used to analyze the qualitative data. This consisted ofdoing open, axial, and selective coding. This study provided detailed descriptions ofthe research approach, researcher's involvement, participant and site selection, data collection and analysis, methodological assumptions and limitations, credibility established, and ethical considerations. The findings ofthe data analysis revealed the theme ofrelationships as central to the learning and recovery process oftherapeutic riding for people with disabilities. The significance ofthe team relationships, the horse and rider relationship, and the providers and rider relationship was found. The essential components ofthe learning and recovery process were presented in a diagram in the selective coding phase. Goals oftherapeutic riding included psycho-education; behavioural and social; physical; and equestrian. Parts ofthe process ofhow outcomes were achieved included motivation; "opens new doors;" risk; task analysis; control; communication; and environmental factors. Outcomes of therapeutic riding included independence and mobility; confidence; and transfer abilities or skills. The implications ofthese findings for theory, practice, and further research were also. explored.
Resumo:
Land managers often respond to declining numbers of target species by creating additional areas of habitat. If these habitats are also subject to human disturbance, then their efforts may be wasted. The European Nightjar (Caprimulgus europaeus) is a ground-nesting bird that is listed as a species of European Conservation Concern. It appears to be susceptible to human disturbance during the breeding season. We examined habitat use and reproductive success over 10 years in a breeding population on 1335 ha of managed land in Nottinghamshire, England. The study site was divided into a heavily disturbed section and a less disturbed section of equal habitat availability, forming a natural long-term experiment. The site is open to the public, and visitor numbers approximately doubled during the study. We found that overall Nightjar density was significantly lower and there were significantly fewer breeding pairs in the heavily disturbed habitat compared with the less disturbed habitat. However, average breeding success per pair, in terms of eggs and fledglings produced, was not significantly different between the two sections across years. Our findings suggest that human recreational disturbance may drastically alter settlement patterns and nest site selection of arriving females in some migratory ground-nesting species and may reduce the utility of apparently suitable patches of remnant and created habitat. Land managers should bear this in mind when creating new areas of habitat that will also be accessible to the public. Our study also highlights the value of long-term population monitoring, which can detect trends that short-term studies may miss.
Resumo:
Nest site selection in arboreal, domatia-dwelling ants, particularly those coexisting on a single host plant, is little understood. To examine this phenomenon we studied the African savannah tree Vachellia erioloba, which hosts ants in swollen-thorn domatia. We found four ant species from different genera (Cataulacus intrudens, Tapinoma subtile, Tetraponera ambigua and an unidentified Crematogaster species). In contrast to other African ant plants, many V. erioloba trees (41 % in our survey) were simultaneously co-occupied by more than one ant species. Our study provides quantitative field data describing: (1) aspects of tree and domatia morphology relevant to supporting a community of mutualist ants, (2) how ant species occupancy varies with domatia morphology and (3) how ant colony size varies with domatia size and species. We found that Crematogaster sp. occupy the largest thorns, followed by C. intrudens, with T. subtile in the smallest thorns. Thorn age, as well as nest entrance hole size correlated closely with ant species occupant. These differing occupancy patterns may help to explain the unusual coexistence of three ant species on individual myrmecophytic trees. In all three common ant species, colony size, as measured by total number of ants, increased with domatia size. Additionally, domatia volume and species identity interact to predict ant numbers, suggesting differing responses between species to increased availability of nesting space. The proportion of total ants in nests that were immatures varied with thorn volume and species, highlighting the importance of domatia morphology in influencing colony structure.
Resumo:
The old paradigm that Amazonia's tropical ecosystems prevented cultural development beyond small-scale shifting agricultural economies, that had little environmental impact, no longer holds true for much of Amazonia. A diversity of archaeological evidence, including terra preta soils, raised fields, causeways, large habitation mounds, geometric earthworks, and megalithic monuments, all point to considerable cultural complexity and environmental impacts. However, uncertainty remains over the chronology of these cultures, their diet and economy, and the scale of environmental impact and land use associated with them. Here, we argue that a cross-disciplinary approach, closely coupling palaeoecology and archaeology, can potentially resolve these uncertainties. We show how, with careful site selection (pairing small and large lakes, close proximity to archaeological sites, transects of soil pits) and choice of techniques (e.g., pollen, phytoliths, starch grains, charcoal, stable isotopes), these two disciplines can be successfully integrated to provide a powerful tool for investigating the relationship between pre-Columbian cultures and their environment.
Resumo:
Met Office station data from 1980 to 2012 has been used to characterise the interannual variability of incident solar irradiance across the UK. The same data are used to evaluate four popular historical irradiance products to determine which are most suitable for use by the UK PV industry for site selection and system design. The study confirmed previous findings that interannual variability is typically 3–6% and weighted average probability of a particular percentage deviation from the mean at an average site in the UK was calculated. This weighted average showed that fewer than 2% of site-years could be expected to fall below 90% of the long-term site mean. The historical irradiance products were compared against Met Office station data from the input years of each product. This investigation has found that all products perform well. No products have a strong spatial trend. Meteonorm 7 is most conservative (MBE = −2.5%), CMSAF is most optimistic (MBE = +3.4%) and an average of all four products performs better than any one individual product (MBE = 0.3%)
Resumo:
Although studies classify the polygynous mating system of a given species into female defense polygyny (FDP) or resource defense polygyny (RDP), the boundary between these two categories is often slight. Males of some species may even shift between these two types of polygyny in response to temporal variation in social and environmental conditions. Here, we examine the mating system of the Neotropical harvestman Acutisoma proximum and, in order to assess if mate acquisition in males corresponds to FDP or RDP, we tested four contrasting predictions derived from the mating system theory. At the beginning of the reproductive season, males fight with other males for the possession of territories on the vegetation where females will later oviposit, as expected in RDP. Females present a marked preference for specific host plant species, and males establish their territories in areas where these host plants are specially abundant, which is also expected in RDP. Later in the reproductive season, males reduce their patrolling activity and focus on defending individual females that are ovipositing inside their territories, as what occurs in FDP. This is the first described case of an arachnid that exhibits a shift in mating system over the reproductive season, revealing that we should be cautious when defining the mating system of a species based on few observations concentrated in a brief period.
Resumo:
Stingless bees (Meliponini) construct their own species-specific nest entrance. The size of this entrance is under conflicting selective pressures. Smaller entrances are easier to defend; however, a larger entrance accommodates heavier forager traffic. Using a comparative approach with 26 species of stingless bees, we show that species with greater foraging traffic have significantly larger entrances. Such a strong correlation between relative entrance area and traffic across the different species strongly suggests a trade-off between traffic and security. Additionally, we report on a significant trend for higher forager traffic to be associated with more guards and for those guards to be more aggressive. Finally, we discuss the nest entrance of Partamona, known in Brazil as boca de sapo, or toad mouth, which has a wide outer entrance but a narrow inner entrance. This extraordinary design allows these bees to finesse the defensivity/traffic trade-off.
Resumo:
Cell division in bacteria is carried out by an elaborate molecular machine composed of more than a dozen proteins and known as the divisome. Here we describe the characterization of a new divisome protein in Bacillus subtilis called YpsB. Sequence comparisons and phylogentic analysis demonstrated that YpsB is a paralog of the division site selection protein DivIVA. YpsB is present in several gram-positive bacteria and likely originated from the duplication of a DivIVA-like gene in the last common ancestor of bacteria of the orders Bacillales and Lactobacillales. We used green fluorescent protein microscopy to determine that YpsB localizes to the divisome. Similarly to that for DivIVA, the recruitment of YpsB to the divisome requires late division proteins and occurs significantly after Z-ring formation. In contrast to DivIVA, however, YpsB is not retained at the newly formed cell poles after septation. Deletion analysis suggests that the N terminus of YpsB is required to target the protein to the divisome. The high similarity between the N termini of YpsB and DivIVA suggests that the same region is involved in the targeting of DivIVA. YpsB is not essential for septum formation and does not appear to play a role in septum positioning. However, a ypsB deletion has a synthetic effect when combined with a mutation in the cell division gene ftsA. Thus, we conclude that YpsB is a novel B. subtilis cell division protein whose function has diverged from that of its paralog DivIVA.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Patterns of nest construction and nest site selection of two murid rodents of the Brazilian Atlantic rainforest were described. The animals were captured in an area of about 1.5 ha of primary forest, marked, equipped with a spool-and-line device and released at the capture point. The next day we followed the thread to find their nests. In total 11 nests of Nectomys squamipes (Brants, 1827) and 13 of Oryzomys intermedius (Leche, 1886) were found. They were all egg-shaped, about 15 cm long and 10 cm wide, without any apparent entrance and consisted of dry leaves and grass. The two species differed in the selection of nest sites. The nests of N. squamipes were close to streams and built inside decomposed fallen logs or using natural entrances between the soil and tangled roots or rocky crevices. Nests of O. intermedius were built under or inside fallen logs and inside aerial root systems of palms. The spool-and-line technique used here is useful to provide detailed information on several aspects of the ecology and natural history of small mammals.