997 resultados para Indicators (Biology)


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Thecamoebian (testate amoeba) species diversity and assemblages in reclamation wetlands and lakes in northeastern Alberta respond to chemical and physical parameters associated with oil sands extraction. Ecosystems more impacted by OSPM (oil sands process-affected material) contain sparse, low-diversity populations dominated by centropyxid taxa and Arcella vulgaris. More abundant and diverse thecamoebian populations rich in difflugiid species characterize environments with lower OSPM concentrations. These shelled protists respond quickly to environmental change, allowing year-to-year variations in OSPM impact to be recorded. Their fossil record thus provides corporations with interests in the Athabasca Oil Sands with a potential means of measuring the progression of highlyimpacted aquatic environments to more natural wetlands. Development of this metric required investigation of controls on their fossil assemblage (e.g. seasonal variability, fossilization potential) and their biogeographic distribution, not only in the constructed lakes and wetlands on the oil sands leases, but also in natural environments across Alberta.

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Science Foundation Ireland (CSET - Centre for Science, Engineering and Technology, Grant No. 07/CE/11147)

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Ambient (03) ozone concentrations were compared to ozone damage on milkweed plants to determine if there was a correlation. Eight survey sites of at least 100 plants each were located within 5 kilometers of Air Quality Index (AQI) stations in southern Ontario. Sites were visited nine times from June-September (2007) and milkweed leaves from 75 plants were assessed using methods pioneered in the United States. Ambient 0 3 results were calculated into SUM65, seasonal cumulative 0 3, and total 03. The 0 3 exposure indices SUM65 and cumulative 0 3 were tested statistically to determine which index is biologically relevant to milkweed as an 0 3 damage indicator species. The milkweed damage indices were incidence of leaves damaged per plant, incidence of plants damaged per site, and total 0 3• The incidence of plants injured per site was the best damage parameter with an F(1,28)=17.37, p=0.0003 for SUM65 and F(1,28)=7.5, p=O.0106 for cumulative 03 .. Milkweed plants showed quantifiable ozone damage with minimal spatial differences in damage and thus have potential use as a biomonitor species in southern Ontario.

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Antioxidant enzymes are involved in important processes of cell detoxification during oxidative stress and have, therefore, been used as biomarkers in algae. Nevertheless, their limited use in fluvial biofilms may be due to the complexity of such communities. Here, a comparison between different extraction methods was performed to obtain a reliable method for catalase extraction from fluvial biofilms. Homogenization followed by glass bead disruption appeared to be the best compromise for catalase extraction. This method was then applied to a field study in a metal-polluted stream (Riou Mort, France). The most polluted sites were characterized by a catalase activity 4–6 times lower than in the low-polluted site. Results of the comparison process and its application are promising for the use of catalase activity as an early warning biomarker of toxicity using biofilms in the laboratory and in the field

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Among increasingly used pharmaceutical products, β-blockers have been commonly reported at low concentrations in rivers and littoral waters of Europe and North America. Little is known about the toxicity of these chemicals in freshwater ecosystems while their presence may lead to chronic pollution. Hence, in this study the acute toxicity of 3 β-blockers: metoprolol, propranolol and atenolol on fluvial biofilms was assessed by using several biomarkers. Some were indicative of potential alterations in biofilm algae (photosynthetic efficiency), and others in biofilm bacteria (peptidase activity, bacterial mortality). Propranolol was the most toxic β-blocker, mostly affecting the algal photosynthetic process. The exposure to 531 μg/L of propranolol caused 85% of inhibition of photosynthesis after 24 h. Metoprolol was particularly toxic for bacteria. Though estimated No-Effect Concentrations (NEC) were similar to environmental concentrations, higher concentrations of the toxic (503 μg/L metoprolol) caused an increase of 50% in bacterial mortality. Atenolol was the least toxic of the three tested β-blockers. Effects superior to 50% were only observed at very high concentration (707 mg/L). Higher toxicity of metoprolol and propranolol might be due to better absorption within biofilms of these two chemicals. Since β-blockers are mainly found in mixtures in rivers, their differential toxicity could have potential relevant consequences on the interactions between algae and bacteria within river biofilms

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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"July 1996."

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Over time, humanity began to realize the negative impact that the modern world has caused to the environment. The Atlantic Forest is one of the richest biomes in biodiversity, covering more than 60% of all species on the planet. This biome covered about 15% of the Brazilian territory, leaving currently only 7% of its fully fragmented forest remnants. This was the biome that suffered most from modernization and strong anthropogenic pressures in Brazil. For the account of environmental degradation, in the second half of the nineteenth century there was a shift in thinking, giving greater emphasis on conservation of some natural landscapes, with the intention of removing the man still preserved nature. Based on American models of conservation there were created the Nature Conservation Units. This study aimed to analyze the environmental quality of the State Park Vitório Piassa, a Conservation Unit located in the city of Pato Branco - PR. The environmental quality was measured by use of bio-indicators and some environmental pressures that the Park has suffered over the years also were identified. Beetles of the familiy Scarabaeinae (Coleoptera: Scarabaeidae) were used as the bioindicators. To compare the most conserved areas and the most degraded areas of the Park, three specific sites were defined within the Atlantic Forest fragment, these insects were captured with pitfall traps and identified as to their species and genera. There were two collections in February and March 2015, which resulted in 945 individuals in 22 species and nine different genus. Then the population of beetles in each area were classified based on ecological measures such as species richness, abundance of individuals of each species through diversity index (Shannon and Simpson) to identify the differences between the sampled groups and equitability (Pielou) to measure the distribution of the total abundance of the species in each area. To meet the objective of identifying the environmental pressures that occur in PEVP, evidence were collected through photographs, watching the field, aerial images and conversations with the resident population in the park. Similarly, if made relevant to build on the project running by the municipality for the construction of infrastructure for public viewing. These data served as subsidies to confront the current situation of the park and the current Brazilian legislation for UC's of full protection, highlighting the existing socio-environmental conflicts in the park, involving political issues and the proximity of the Conservation Unit with the urban area of the city.

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Air pollution can threat the environment and public health, and is assess by pollutant ́s concentration measurements in order to verify whether the limits set by environmental agencies are being respected. However, these measures do not indicate immediately the impacts to living beings. To faced this problem, plants are been investigated as potential bioindicators of air pollution and, among them, stand out bromeliads Tillandsia genus which colonize various substrates,. obtaining water and nutrients from the atmosphere directly. In this context, this research assessed the potential of epiphytic bromeliad Tillandsia recurvata (L.) L. found in urbanized areas of the city of Curitiba - PR as a bioindicator of urban air pollution. According to vehicle traffic, five sample points were selected and classified. Points P1 and P2 were classified as high-traffic vehicle due presenting trucks and urban transport; point P3 was classified as moderate traffic due the predominance of private vehicles and urban transport; and points P4 and P5 were classified as low-traffic, presenting circulation of private vehicles only. There were analyzed the abundance of T. recurvata, morphophysiological parameters (leaf area, leaf specific area, sclerophylly index, percentage dry weight / fresh weight, chlorophyll (a + b), analysis of structural mesophyll organization) and the heavy metals accumulation (Fe, Cd, Cr, Cu, Pb and Zn). The abundance analysis and the results obtained for metals analysis were correlated with the intensity of vehicular traffic, directing the sampling points P1 > P2 = P3 > P4 = P5. This result demonstrate that the abundance of T. recurvata is greater in urban air pollution impacted areas, thus indicating that T. recurvata absorbs and accumulates metals and can be used in biomonitoring of urban air pollution in areas impacted by vehicular traffic. Morphophysiological parameters analyzed shows that the internal plant ́s structure is not significantly impacted by urban air pollution due plant ́s adptations. The presence of absorbing scales, the CAM metabolism pathway and it ́s store water ability, among other features, demonstrate their potential as bio-indicator in urban areas, especially regarding heavy metals accumulation .

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Recent epidemiologic studies have suggested that ultraviolet radiation (UV) may protect against non-Hodgkin lymphoma (NHL), but few, if any, have assessed multiple indicators of ambient and personal UV exposure. Using the US Radiologic Technologists study, we examined the association between NHL and self-reported time outdoors in summer, as well as average year-round and seasonal ambient exposures based on satellite estimates for different age periods, and sun susceptibility in participants who had responded to two questionnaires (1994–1998, 2003–2005) and who were cancer-free as of the earlier questionnaire. Using unconditional logistic regression, we estimated the odds ratio (OR) and 95% confidence intervals for 64,103 participants with 137 NHL cases. Self-reported time outdoors in summer was unrelated to risk. Lower risk was somewhat related to higher average year-round and winter ambient exposure for the period closest in time, and prior to, diagnosis (ages 20–39). Relative to 1.0 for the lowest quartile of average year-round ambient UV, the estimated OR for successively higher quartiles was 0.68 (0.42–1.10); 0.82 (0.52–1.29); and 0.64 (0.40–1.03), p-trend = 0.06), for this age period. The lower NHL risk associated with higher year-round average and winter ambient UV provides modest additional support for a protective relationship between UV and NHL.

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The 2010 biodiversity target agreed by signatories to the Convention on Biological Diversity directed the attention of conservation professionals toward the development of indicators with which to measure changes in biological diversity at the global scale. We considered why global biodiversity indicators are needed, what characteristics successful global indicators have, and how existing indicators perform. Because monitoring could absorb a large proportion of funds available for conservation, we believe indicators should be linked explicitly to monitoring objectives and decisions about which monitoring schemes deserve funding should be informed by predictions of the value of such schemes to decision making. We suggest that raising awareness among the public and policy makers, auditing management actions, and informing policy choices are the most important global monitoring objectives. Using four well-developed indicators of biological diversity (extent of forests, coverage of protected areas, Living Planet Index, Red List Index) as examples, we analyzed the characteristics needed for indicators to meet these objectives. We recommend that conservation professionals improve on existing indicators by eliminating spatial biases in data availability, fill gaps in information about ecosystems other than forests, and improve understanding of the way indicators respond to policy changes. Monitoring is not an end in itself, and we believe it is vital that the ultimate objectives of global monitoring of biological diversity inform development of new indicators. ©2010 Society for Conservation Biology.

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Three species of Australian endemic catsharks (grey spotted catshark Asymbolus analis, orange spotted catshark A. rubiginosus and Australian sawtail shark Figaro boardmani) were collected from the trawl grounds of a highly seasonal commercial fishery off southern Queensland, Australia. Specimens were collected on the mid to outer continental shelf at depths between 78 and 168 m. This study provides the first information on the reproductive biology of these three poorly-known species. Mature female and male A. analis were observed from 455 mm total length (TL), mature female A. rubiginosus from 410 mm TL, mature male A. rubiginosus from 405 mm TL, mature female F. boardmani from 402 mm TL and mature male F. boardmani from 398 mm TL (although a lack of immature specimens precluded more accurate assessments of size at maturity). The reproductive mode of all species was confirmed as single oviparous (carrying only one egg case in each uterus at a time). Ovarian fecundity (the number of vitellogenic follicles) ranged from 7-20 in A. analis, 5-23 in A. rubiginosus and 9-13 in F. boardmani. Several indicators suggest that Asymbolus catsharks off southern Queensland are reproductively active year-round. The proportion of female A. rubiginosus carrying egg cases was highest in spring (60%), intermediate in autumn (50%) and lowest in winter (44%).

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Temporal and spatial patterns in parasite assemblages were examined to evaluate the degree of movement and connectivity of post-recruitment life-history stages of a large, non-diadromous tropical estuarine teleost, king threadfin Polydactylus macrochir, collected from 18 locations across northern Australia. Ten parasites types (juvenile stages of two nematodes and seven cestodes, and adults of an acanthocephalan) were deemed to be suitable for use as biological tags, in that they were considered to have a long residence time in the fish, were relatively easy to find and were morphologically very different to each other which aided discrimination. Univariate and discriminant function analysis of these parasites revealed little difference in temporal replicates collected from five locations, suggesting that the parasite communities were stable over the timeframes explored. Univariate, discriminant function, and BrayCurtis similarity analyses indicated significant spatial heterogeneity, with BrayCurtis classification accuracies ranging from 55 to 100% for locations in north-western and northern Australia, 24 to 88% in the Gulf of Carpentaria, and 39 to 88% on the east coast of Queensland. Few differences were observed among locations separated by <200 km. The observed patterns of parasite infection are in agreement with concurrent studies of movement and connectivity of P. macrochir in that they indicate a complex population structure across northern Australia. These results should be considered when reviewing the management arrangements for this species.

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ENGLISH: The purpose of this study was to investigate the possibility that certain species of Chaetognatha found in Eastern Tropical Pacific waters can serve as biological indicators of oceanographic features. "Indicator" organisms have been found useful in identifying water types, in tracing the pattern of current systems, and in tracing the origin of moving water masses. To be of use in this type of study, the organisms must be sufficiently abundant to be readily sampled, and easily identified to species; they must also, at least partially, fulfill the additional requisites listed and discussed by Sverdrup, Johnson, and Fleming (1942, pp. 866-867). Among several groups of organisms fulfilling these requirements are the Chaetognatha. Specimens of this group of animals occurred in large numbers in the plankton samples used for this study. The works of Thomson (1947), Fraser (1942), Ritter-Zahony (1911), and Sund (1959) were used for identification. SPANISH: El objetivo de este estudio ha sido el de investigar la posibilidad de utilizar ciertas especies de quetognatos encontrados en el Pacífico Oriental Tropical como indicadoras biológicas de características oceanográficas. Organismos "indicadores" fueron encontrados útiles para la identificación de tipos de agua, el trazado del régimen de los sistemas de corrientes y la determinación del origen de masas de agua en movimiento. Para servir a este tipo de estudios, los organismos deben ser lo suficientemente abundantes como para ser fácilmente muestreados e identificados hasta la especie; también deben satisfacer, por lo menos parcialmente, los requerimientos indicados y discutidos par Sverdrup, Johnson y Fleming (1942, pags. 866-867).