976 resultados para Mammal composition
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Introduction The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. Methods The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. Results A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. Conclusions The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração.
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ABSTRACT INTRODUCTION: In this study, we evaluated the chemical composition of a commercial sample of essential oil from Eucalyptus smithii R.T. Baker and its antifungal activity against Microsporum canis ATCC 32903, Microsporum gypseum ATCC 14683, Trichophyton mentagrophytes ATCC 9533, T. mentagrophytes ATCC 11480, T. mentagrophytes ATCC 11481, and Trichophyton rubrum CCT 5507. METHODS: Morphological changes in these fungi after treatment with the oil were determined by scanning electron microscopy (SEM). The antifungal activity of the oil was determined on the basis of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values. RESULTS: The compound 1,8-cineole was found to be the predominant component (72.2%) of the essential oil. The MIC values of the oil ranged from 62.5μg·mL−1 to >1,000μg·mL−1, and the MFC values of the oil ranged from 125μg·mL−1 to >1,000μg·mL−1. SEM analysis showed physical damage and morphological alterations in the fungi exposed to this oil. CONCLUSIONS: We demonstrated the potential of Eucalyptus smithii essential oil as a natural therapeutic agent for the treatment of dermatophytosis.
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This paper studies the changes in European stock market indexes composition from 1995 to 2015. It was found that there are mixed price effects producing abnormal returns around the effective replacement of added and deleted stocks. The price pressure hypothesis seems to hold for added stocks in some indexes but not for deleted stocks as there is not a clear inversion of behaviour after the replacement. Finally, the building and back testing of a trading strategy aiming to capture some of those abnormal returns shows it yields a Sharpe Ratio of 1.4 and generates an annualised alpha of 11%.
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The impact of the Board of Directors’ composition on companies’ performance This paper studies the impact that the board of directors’ composition has on companies’ performance in the Italian market. The research has been carried out by using a sample of 10 Italian companies, across different market sectors, over a period of 10 years (2005-2014). The characteristics of the BoD taken into consideration are the following: board size, board diversity (% of female directors), board independence and CEO duality. Results from the sample data collected concluded that these factors have a statistically significant impact on the performance of the companies that have been analysed.
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Field measurement programs in Brazil during the dry season months of August and September in 1979 and 1980 have demonstrated the great importance of the continental tropics in global air chemistry. Especially in the mixed layer, the air composition over land is much different from that over the ocean and the land areas are clearly longe scale sources of many inportant trace gases. During the dry season much biomass, burning takes place especially in the cerrado regions leading to substantial emission of air pollutants, such as CO, NOx, N2O, CH4 and other hydrocarbons. Ozone concentrations are alsoenhanced due to photochemical reactions. Biogenic organic emissions from tropical forests play likewise an important role in the photochemistry of the atmosphere. Carbon monoxide was found to be present in high concentrations in the boundary layer of the tropical forest, but ozone concentrations were much lower than in the cerrado.
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Some of the trends and characteristics of the isotopic composition oh precipitation in tropical stations are discussed. Stations in small Pacific islands show a variation with latitude, with lower 8-values between 15°N and 1S°S and higher values at higher. Inland stations are depleted in heavy isotopes with respect to coastal stations but sometimes this continental effect is rather complex, as f,or instance in África. Mean monthly 8-values show a remarkable correlation with the amount of precipitation, but the slope variations do not show a clear dependence on the mean long term 8-value,as should be expected theoretically. In Southern American stations the seasonal variations of the meanmonthly 5-values are correlated and they are greater in inland stations due to con-tinentaly. The possible effects of recycling of water vapour by evapotranspiration are also discussed.
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Abundances of msmall terrestrial mammals were estimated in 10 and 100-ha, isolated and non-isolated primary forest reserves near, Manaus, Brazil between October 1983 and March 1984. The smalt mammal abundance pattern In a 10 ha reserve isolated fan appoximately three years differed significantly from that in othen reserves, primarily due to higher capture rates of Marmosa cinerea, Rhipidomys mastacalis, and Onyzomys paricola in the isolated reserve. Viet type and re-invasion potential may be important factors the small mammal communities in forest patches. Variation the small mammal community among othen reserves was pnimanlty due to variatton In the abundances of Proechimys and 0. capito. At least pant of this vantation was attributable to temporal efects, but variation due to reserve effects also was suggested. Small mammals were much more abundant in the reserves during the present study than in 1982.
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One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.
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Changes in the floristic composition over an eight-year period in a logged area at the Tapajós National Forest in Brazilian Amazonia arc discussed. Two treatments of different intensities of logging were compared with an undisturbed (control) forest. Data were collected from permanent sample-plots. The effects of logging on floristic composition were stronger in the more heavily logged treatment. The number of species decreased immediately after logging, but started to increase before the fifth year after logging and was higher at the end of the study period than before logging. The more heavily logged plots responded more to disturbances, as judged by the increase in the number of species during the period after logging. This forest appears to recover its initial floristic composition after disturbance without intervention.
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Using a sample of Portuguese audit firms and their client companies, this study examines the association between gender composition of the partnership structure oaudit firms and audit quality. Audit quality is measured through the earnings quality of audit clients. We find that gender diversity in the partnership structure of audit firms, per se, has no association with audit quality. In turn, we find significant evidence that a predominant presence of female Certified Public Accountants (CPAs) in partner positions in audit firms is associated with higher audit quality. In particular, the results indicate that audit firms with female-dominated partnership structures are negatively related with aggressive accounting practices in audit clients.
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Bryophyte diversity in Amazonian Brazil is high, presently recorded at 514 species distributed among 36 families and 89 genera. Comparisions of species richness among the Amazonian states of Brazil suggests that the bryoflora of Acre is still underestimated, presently recorded at 106 species distributed among 33 families and 63 genera. After two field trips, the diversity increased 50% showing that the bryoflora is still poorly known. Collection data and comments on morphology, ecology and distribution are given for sixty-two species of bryophytes collected in the state of Acre, Brazil, which are new (fifty-two species) or interesting floristic records (ten species). Microlejeunea crenulifolia (Gottsche) Steph. and Stictolejeunea balfourdii Mitt. are new records for Brazil and fifty species are new records for Acre.
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The herb community of tropical forests is very little known, with few studies addressing its structure quantitatively. Even with this scarce body of information, it is clear that the ground herbs are a rich group, comprising 14 to 40% of the species found in total species counts in tropical forests. The present study had the objective of increasing the knowledge about the structure and composition of the ground-herb community and to compare the sites for which there are similar studies. The study was conducted in a tropical non-inundated and evergreen forest 90 km north of Manaus, AM. Ground herbs were surveyed in 22 transects of 40 m², distributed in five plots of 4 ha. The inventoried community was composed of 35 species, distributed in 24 genera and 18 families. Angiosperms were represented by 8 families and Pteridophytes by 10 families. Marantaceae (12 sp) and Cyperaceae (4 sp) were the richest families. Marantaceae and Poaceae were the families with greatest abundance and cover. Marantaceae, Poaceae, Heliconiaceae and Pteridophytes summed 96% of total herb cover, and therefore were responsible for almost all the cover of the community. The 10 most important species had 83.7% of the individuals. In general, the most abundant species were also the most frequent. Richness per transect varied from 7 to 19 species, and abundance varied from 30 to 114 individuals. The community structure was quite similar to 3 other sites in South America and one site in Asia.
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This study, which involved a target population comprised by 292 workers of different industrial areas (metalmechanics, foundry, chemical, wood, food), aimed to verify the association between energy expenditure-EE, physical activity level-PAL and body composition (Body Mass Index-BMI, Waist-Hip Ratio-WHR and Waist To Height Ratio, WTHR) of participants. The work was completed with the description of the variables relating to the gender of the individuals (male and female) and the activities carried out in the two sectors of industrial work (administrative sector and productive sector). In this research, the statistical technique of principal components analysis (PCA) and the hierarchical analysis of clusters (HCA) were used. Sociodemographic and anthropometric data were collected as well as the level of physical activity and energy expenditure were assessed. The vast majority of individuals who spend greater energy expenditure and has more intense physical activity were male. Most of these workers are in the production sector. We can confirm that that both, gender and labor activity, are factors that have influence on the EE and the PAL.
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The essential oil of the leaves and fine stems of Aniba canelilla (Kunth) Mez collected in the city of Manaus, AM, Brazil, were obtained by hydrodistillation and analyzed by GC/MS. Forty-two components were identified, of which 1-nitro-2-phenylethane, as expected, was the major (71.2%-68.2%).
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Essential oils from leaves and fruits of Protiumheptaphyllum collected in Tamandaré beach Pernambuco/Brazil were analysed by GC/MS and tested for toxicity and repellent effect against the two spotted spider mite (Tetranychus urticae). The major constituent identified in the fruits was alpha-terpinene (47.6 %) whereas oil from leaf contained mainly sesquiterpenes such as 9-epi-caryophyllene (21.4 %), trans-isolongifolanone (10.7 %) and 14-hydroxi-9-epi-caryophyllene (16.7 %). The fruit oil was found to be more effective against the mite when compared to the leaf oil. Both showed mortality properties and oviposition deterrence in higher concentration (10 µl.l-1 air), but only the essential oil from fruits induced repellence on T. urticae.