10 resultados para Biodiversidade Insular

em Deakin Research Online - Australia


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In the light of the currently increasing drought frequency and water scarcity on oceanic islands, it is crucial for the conservation of threatened insular vertebrates to assess how they will be affected. A 4000 yr old fossil assemblage in the Mare Aux Songes (MAS), southwest Mauritius, Mascarene Islands, contains bones of 100 000+ individual vertebrates, dominated by two species of giant tortoises Cylindraspis triserrata and C. inepta, the dodo Raphus cucullatus, and 20 other vertebrate species (Rijsdijk, Hume, Bunnik, Florens, Baider, Shapiro et al. (2009) Mid-Holocene vertebrate bone Concentration-Lagerstätte on oceanic island Mauritius provides a window into the ecosystem of the dodo (Raphus cucullatus). Quaternary Science Reviews 28: 14–24). Nine radiocarbon dates of bones statistically overlap and suggest mass mortality occurred between 4235 and 4100 cal. yr BP. The mortality period coincides with a widely recognized megadrought event. Our multidisciplinary investigations combining geological, paleontological and hydrological evidence suggests the lake was located in a dry coastal setting and had desiccated during this period. Oxygen isotope data from a Uranium-series dated stalagmite from Rodrigues, an island 560 km east of Mauritius, supports this scenario by showing frequently alternating dry and wet periods lasting for decades between 4122 and 2260 cal. yr BP. An extreme drought resulted in falling water-tables at MAS and elsewhere on the island, perhaps deprived these insular vertebrates of fresh water, which led to natural mass mortalities and possibly to extirpations. In spite of these events, all insular species survived until at least the seventeenth century, confirming their resistance to climatic extremes. Despite this, the generally exponential increase of combined human impacts on islands including loss of geodiversity, habitats, and stocks of fresh water, there will be less environmental safe-haven options for insular endemic and native vertebrates during future megadrought conditions; and therefore will be more prone to extinction.

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There are only 5,000 patients in psychoanalysis with members of the American Psychoanalytic Association (APsaA), and these analysts are often viewed as arrogant and insular. As a laboratory for psychoanalytic institutions the APsaA provides crucial lessons for the future across the field. What ingredients are needed for psychoanalysis to be a vibrant discipline? What factors have prevailed where psychoanalysis is successful? The author explores the cases of Argentina and France, where psychoanalysis is relatively popular, and then returns to the U.S. situation. Insular mind-sets led to many missed opportunities for cultural and academic engagement in the United States. As an example, the author explores responses to the making of John Huston's film Freud: The Secret Passion. To become revitalized, psychoanalysis needs to be a cultural asset. Psychoanalysts need to build bridges, engage in partnerships, and emphasize the exciting method of philosophical probing of the human mind and the nature of human nature.

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Careful consideration by managers of the potential impact of the popular strategy of economic restructuring (downsizing) on organisational structure and culture could improve the quality of organisational knowledge sharing, however this influence has not yet been addressed in the knowledge management literature. This paper explores how a strategy of downsizing may reshape organisational structure and culture and inhibit organisational knowledge sharing, drawing on an interpretive case study of knowledge sharing in an information technology services function at a large Australian education service provider. Key findings indicate that when specialised teams are downsized, subcultures may develop where teams become mistrustful and insular, and knowledge sharing is constrained across teams. Further, when a hierarchical structure is present and downsizing occurs, managers may become more cautious about sharing knowledge with subordinates. The study also suggests that Internet technologies may play a key role in helping to compensate for the shortfall in knowledge stock resulting from downsizing. In conclusion, this paper highlights an important need for companies to consider the potential negative influences of downsizing on organisationalknowledge sharing.

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Background: 'MRI negative PET positive temporal lobe epilepsy' represents a substantial minority of temporal lobe epilepsy (TLE). Clinicopathological and qualitative imaging differences from mesial temporal lobe epilepsy are reported. We aimed to compare TLE with hippocampal sclerosis (HS+ve) and non lesional TLE without HS (HS-ve) on MRI, with respect to quantitative FDG-PET and MRI measures.

Methods: 30 consecutive HS-ve patients with well-lateralised EEG were compared with 30 age- and sex-matched HS+ve patients with well-lateralised EEG. Cerebral, cortical lobar and hippocampal volumetric and co-registered FDG-PET metabolic analyses were performed.

Results: There was no difference in whole brain, cerebral or cerebral cortical volumes. Both groups showed marginally smaller cerebral volumes ipsilateral to epileptogenic side (HS-ve 0.99, p = 0.02, HS+ve 0.98, p < 0.001). In HS+ve, the ratio of epileptogenic cerebrum to whole brain volume was less (p = 0.02); the ratio of epileptogenic cerebral cortex to whole brain in the HS+ve group approached significance (p = 0.06). Relative volume deficits were seen in HS+ve in insular and temporal lobes. Both groups showed marked ipsilateral hypometabolism (p < 0.001), most marked in temporal cortex. Mean hypointensity was more marked in epileptogenic-to-contralateral hippocampus in HS+ve (ratio: 0.86 vs 0.95, p < 0.001). The mean FDG-PET ratio of ipsilateral to contralateral cerebral cortex however was low in both groups (ratio: HS-ve 0.97, p < 0.0001; HS+ve 0.98, p = 0.003), and more marked in HS-ve across all lobes except insula.

Conclusion: Overall, HS+ve patients showed more hippocampal, but also marginally more ipsilateral cerebral and cerebrocortical atrophy, greater ipsilateral hippocampal hypometabolism but similar ipsilateral cerebral cortical hypometabolism, confirming structural and functional differences between these groups.

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Australia’s encounters with the Middle East have historically been defined initially through its membership of the British Empire, later as a key Commonwealth player and more recently through Australia's close strategic relationship with the US. This book traces the nature of the Australia-Middle East relationship, from an insular ‘White Australia’ ideology through to the global impact of September 11, the wars in Afghanistan and Iraq and the new and menacing terror threat that has arrived on its own doorstep. A comprehensive analysis of this complex relationship provides an essential basis for understanding past encounters, evaluating present policies and developing a framework for future interactions. The book seeks to draw together the various dimensions and themes of this relationship – from trade and migration, to Australia’s increasing strategic interest and current military involvement in the region.

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Good governance is recognized as a fundamental indicator of the success of a company. For a small- midsized company, this is particularly so, as such companies must be able to competitively demonstrate their flexibility in the face of market forces. This flexibility is the primary advantage they hold over larger firms (Dalton, Daily, Ellstrand and Johnson, 1998).

Such companies, however, can find it difficult to attract good directors (Daum and Neff, 2003) and this makes developing improved strategies of governance a challenge. Taylor, Chait and Holland suggest top directors are not attracted to small/ medium companies because "the stakes remain low, the meetings process-driven, the outcomes ambiguous, and the deliberations insular" (Taylor, Chait and Holland, 2001). We suggest that the attraction of quality directors is a uniquely impacting situation for small and mid-size firms, as it is there where additional management resources should be needed most urgently.

Directors on the boards of small-medium sized businesses are often lagging behind directors of large companies in that they are less likely to be independent external directors and are less likely to represent a diversity of attributes (Dalton, Daily, Ellstrand and Johnson, 1998). Arthur Levitt, former United States Securities and Exchange Commission Chair, describes the culture of medium sized business directorships as a "kind of a fraternity of CEOs who serve on one another's boards" (Stainburn, 2005). In addition, evidence suggests directors of small- medium businesses are often insufficiently trained for the role. Uncertain directors may, for example, be unwilling to ask crucial questions of managers before making major decisions. "Board members sometimes are made to feel that asking a thorny question or advancing an alternative opinion is disloyal to the administration" (Taylor, Chait and Holland, 2001).

Small and medium businesses, however, are a growing contributor to the national economies of countries internationally. In New Zealand, small and medium-size firms recording large GDP values, ahead of many large businesses, which makes our investigation into good governance practices of SMEs relevant to suggest areas in which these firms can improve their governance policies and practices.

We have reviewed more than 2,000 directors, executives and investors in New Zealand, making this one of the largest non-government surveys in governance. Supported by 16 large corporate organizations, such as KPMG, Business New Zealand, Simpson Grierson, Brook Asset Management, Porter Novelli, Sheffield and 'Management' Magazine, this work suggests that the current processes through which directors are selected and trained to serve on Boards of small and medium businesses needs to be altered. We are also concerned over the lack of director education and the close involvement of the Chief Executives as members of the Boards. There is a general concern over the lack of director independence and whether directors are effective in their roles.

We are recommending an alternative process for SMEs to select directors, which will hopefully expand the available pool of directors in quantity and quality.

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Good governance is recognized as a fundamental indicator of the success of a company. For a small- midsized company, this is particularly so, as such companies must be able to competitively demonstrate their flexibility in the face of market forces. This flexibility is the primary advantage they hold over larger firms (Dalton, Daily, Ellstrand and Johnson, 1998). Such companies, however, can find it difficult to attract good directors (Daum and Neff, 2003) and this makes developing improved strategies of governance a challenge. Taylor, Chait and Holland suggest top directors are not attracted to small/ medium companies because “the stakes remain low, the meetings process-driven, the outcomes ambiguous, and the deliberations insular” (Taylor, Chait and Holland, 2001). We suggest that the attraction of quality directors is a uniquely impacting situation for small and mid-size firms, as it is there where additional management resources should be needed most urgently. Directors on the boards of small-medium sized businesses are often lagging behind directors of large companies in that they are less likely to be independent external directors and are less likely to represent a diversity of attributes (Dalton, Daily, Ellstrand and Johnson, 1998). Arthur Levitt, former United States Securities and Exchange Commission Chair, describes the culture of medium sized business directorships as a “kind of a fraternity of CEOs who serve on one another's boards” (Stainburn, 2005). In addition, evidence suggests directors of small- medium businesses are often insufficiently trained for the role. Uncertain directors may, for example, be unwilling to ask crucial questions of managers before making major decisions. “Board members sometimes are made to feel that asking a thorny question or advancing an alternative opinion is disloyal to the administration” (Taylor, Chait and Holland, 2001). Small and medium businesses, however, are a growing contributor to the national economies of countries internationally. In New Zealand, small and medium-size firms recording large GDP values, ahead of many large businesses, which makes our investigation into good governance practices of SMEs relevant to suggest areas in which these firms can improve their governance policies and practices. We have reviewed more than 2,000 directors, executives and investors in New Zealand, making this one of the largest non-government surveys in governance. Supported by 16 large corporate organizations, such as KPMG, Business New Zealand, Simpson Grierson, Brook Asset Management, Porter Novelli, Sheffield and ‘Management’ Magazine, this work suggests that the current processes through which directors are selected and trained to serve on Boards of small and medium businesses needs to be altered. We are also concerned over the lack of director education and the close involvement of the Chief Executives as members of the Boards. There is a general concern over the lack of director independence and whether directors are effective in their roles. We are recommending an alternative process for SMEs to select directors, which will hopefully expand the available pool of directors in quantity and quality.

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Objective This study aimed to identify persistent morphological changes subsequent to an acute single-time exposure to sarin, a highly poisonous organophosphate, and the neurobiological basis of long-lasting somatic and cognitive symptoms in victims exposed to sarin.

Methods Thirty-eight victims of the 1995 Tokyo subway sarin attack, all of whom had been treated in an emergency department for sarin intoxication, and 76 matched healthy control subjects underwent T1-weighted and diffusion tensor magnetic resonance imaging (DTI) in 2000 to 2001. Serum cholinesterase (ChE) levels measured immediately and longitudinally after the exposure and the current severity of chronic reports in the victims were also evaluated.

Results The voxel-based morphometry exhibited smaller than normal regional brain volumes in the insular cortex and neighboring white matter, as well as in the hippocampus in the victims. The reduced regional white matter volume correlated with decreased serum cholinesterase levels and with the severity of chronic somatic complaints related to interoceptive awareness. Voxel-based analysis of diffusion tensor magnetic resonance imaging further demonstrated an extensively lower than normal fractional anisotropy in the victims. All these findings were statistically significant (corrected p < 0.05).

Interpretation Sarin intoxication might be associated with structural changes in specific regions of the human brain, including those surrounding the insular cortex, which might be related to elevated subjective awareness of internal bodily status in exposed individuals.

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Invasive rodent species have established on 80% of the world's islands causing significant damage to island environments. Insular ecosystems support proportionally more biodiversity than comparative mainland areas, highlighting them as critical for global biodiversity conservation. Few techniques currently exist to adequately detect, with high confidence, species that are trap-adverse such as the black rat, Rattus rattus, in high conservation priority areas where multiple non-target species persist. This study investigates the effectiveness of camera trapping for monitoring invasive rodents in high conservation areas, and the influence of habitat features and density of colonial-nesting seabirds on rodent relative activity levels to provide insights into their potential impacts. A total of 276 camera sites were established and left in situ for 8 days. Identified species were recorded in discrete 15 min intervals, referred to as 'events'. In total, 19 804 events were recorded. From these, 31 species were identified comprising 25 native species and six introduced. Two introduced rodent species were detected: the black rat (90% of sites), and house mouse Mus musculus (56% of sites). Rodent activity of both black rats and house mice were positively associated with the structural density of habitats. Density of seabird burrows was not strongly associated with relative activity levels of rodents, yet rodents were still present in these areas. Camera trapping enabled a large number of rodents to be detected with confidence in site-specific absences and high resolution to quantify relative activity levels. This method enables detection of multiple species simultaneously with low impact (for both target and non-target individuals); an ideal strategy for monitoring trap-adverse invasive rodents in high conservation areas.