32 resultados para Resident fishes

em Deakin Research Online - Australia


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Twenty-one molecular genetic studies of thirteen antitropical Pacific fishes are herein reviewed. High dispersal potentials and Plio-Pleistocene transequatorial divergence are suggested for approximately half of the taxa studied, consistent with movement across the tropics during glacial periods. Divergences within two fish groups were mid-Miocene in age, corresponding to a period suggested for vicariant isolation associated with equatorial warming, but high dispersal potentials complicate the interpretation of biogeographic history. Only one study suggested transequatorial divergence older than 20 million years. There is a greater proportion of Pleistocene transequatorial divergences in the East Pacific than the West Pacific, consistent with the suggestion that conditions in the East Pacific are more amenable to the formation of antitropical distributions. Multiple transequatorial divergences have been observed within at least two groups, and instances of cryptic speciation have been identified twice. Areas for future research concern taxa that differ from the majority studied to date with respect to latitudinal distribution, bathymetry, evolutionary age, and dispersal potential. Molecular characters have demonstrated utility for the study of antitropical fishes, but with limitations.

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This paper analyses the impact of a boom in tourism on the welfare of the residents in the presence of guest workers. Guest workers are employed in the tourism industry and they consume non-traded goods and services. This consumption by guest workers converts non-traded goods into
exportables and creates guest worker generated monopoly power in trade in the home country. It is established that under certain plausible conditions a tourist boom (in the presence of guest workers) results in the immiserization of the resident population. This result arises due to an adverse movement in the terms-of-trade, specifically those associated with the guest workers consumption of non-traded goods. These results are based on a static model of trade and may not be necessarily
valid in a growth model with guest workers, tourism and labor shortages. It is not the object of the paper to be either anti-tourism or anti-guest worker, but only to show a possible source of resident immiserization that is associated with guest workers. This possibility may require correction via a suitable policy both in static and dynamic models.

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This print hung in Alfred Deakin's study in 'Llanarth', South Yarra. It is a print of Raphael's original cartoon for the Sistine Chapel tapestries, drawn by him and his workshop in 1515. The original cartoona are in the Victoria and Albert Museum.

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The gills are considered major targets for cardiac natriuretic peptides with studies confirming natriuretic peptide receptor presence on vascular and sometimes epithelial tissues. Natriuretic peptide intracellular signalling is via guanylyl cyclase receptors and the cGMP pathway, and via inhibitory G-proteins linked to cyclic AMP pathways. Natriuretic peptides in the gills alter branchial blood flow and may also alter ion transport in various salinities. We present an overview of natriuretic peptide cGMP and cAMP signalling in fishes and consider the implications of the recent discovery of several CNPs and BNP in bony fishes on natriuretic peptide receptor studies.

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Background Identifying the factors associated with greater increases in resident engagement has the potential to enhance the effectiveness of active support (AS).

Method Observational data from Stancliffe, Harman, Toogood, and McVilly's (2007) study of AS were analysed to evaluate amount of staff help, effectiveness of staff help, and staff use of praise.

Results Lag analyses showed that antecedent staff help was consistently followed by resident engagement at pre-test. This strong association did not increase significantly at post-test. Resident engagement was more likely to follow staff help than the other way around. There was an increase from pre-test to post-test in help and praise by staff. The higher absolute amount of praise was largely the result of the increase in staff help.

Conclusions The amount of staff help, its effectiveness, and use of praise by staff may each be important in increasing engagement. These factors should continue to be the focus of research attention and applied efforts to help ensure active support is consistently effective.

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Natriuretic peptide hormones exert their effects by binding to receptor proteins and activating cellular responses. Fish gills interface with the aquatic environment. Therefore, natriuretic peptide receptor activity in gills from marine and freshwater fishes was examined. The potencies of natriuretic peptides were compared and a novel cellular response was identified.

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Fish must maintain their internal ionic concentration. This occurs through co-ordination of cellular ion channels and transporters, and hormones acting on and within the cells of the gill, kidney, intestine, and, in some species, unique organs. This study measured some of these transporters and hormones in unusual species of the Australasian region.

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Nitric oxide is an important molecule in the regulation of the cardiovascular system and blood pressure. This research provided new insights into the evolution of nitric oxide control of blood vessels by showing how nitric oxide signalling causes vasodilation in the circulation of amphibians and fishes.

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The exchange of sodium and protons across the gills of fishes has long been associated with osmoregulatory and acid-base regulatory mechanisms in both freshwater and marine fishes. This thesis identifies several types of sodium/proton exchangers in the gills of fishes from different taxonomic classes. In addition, it was observed that the expression of sodium/proton exchanger messenger RNA was upregulated for 24 hours following induced metabolic acidosis in the Atlantic hagfish suggesting that sodium/proton exchangers have functioned in acid/base regulation from early in vertebrate history.

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Background
The Resident Assessment Instrument-Minimum Data Set (RAI-MDS) 2.0 is designed to collect the minimum amount of data to guide care planning and monitoring for residents in long-term care settings. These data have been used to compute indicators of care quality. Use of the quality indicators to inform quality improvement initiatives is contingent upon the validity and reliability of the indicators. The purpose of this review was to systematically examine published and grey research reports in order to assess the state of the science regarding the validity and reliability of the RAI-MDS 2.0 Quality Indicators (QIs).

Methods
We systematically reviewed the evidence for the validity and reliability of the RAI-MDS 2.0 QIs. A comprehensive literature search identified relevant original research published, in English, prior to December 2008. Fourteen articles and one report examining the validity and/or reliability of the RAI-MDS 2.0 QIs were included.

Results
The studies fell into two broad categories, those that examined individual quality indicators and those that examined multiple indicators. All studies were conducted in the United States and included from one to a total of 209 facilities. The number of residents included in the studies ranged from 109 to 5758. One study conducted under research conditions examined 38 chronic care QIs, of which strong evidence for the validity of 12 of the QIs was found. In response to these findings, the 12 QIs were recommended for public reporting purposes. However, a number of observational studies (n=13), conducted in "real world" conditions, have tested the validity and/or reliability of individual QIs, with mixed results. Ten QIs have been studied in this manner, including falls, depression, depression without treatment, urinary incontinence, urinary tract infections, weight loss, bedfast, restraint, pressure ulcer, and pain. These studies have revealed the potential for systematic bias in reporting, with under-reporting of some indicators and over-reporting of others.

Conclusion

Evidence for the reliability and validity of the RAI-MDS QIs remains inconclusive. The QIs provide a useful tool for quality monitoring and to inform quality improvement programs and initiatives. However, caution should be exercised when interpreting the QI results and other sources of evidence of the quality of care processes should be considered in conjunction with QI results.

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Improved access to multibeam sonar and underwater video technology is enabling scientists to use spatially-explicit, predictive modelling to improve our understanding of marine ecosystems. With the growing number of modelling approaches available, knowledge of the relative performance of different models in the marine environment is required. Habitat suitability of 5 demersal fish taxa in Discovery Bay, south-east Australia, were modelled using 10 presence-only algorithms: BIOCLIM, DOMAIN, ENFA (distance geometric mean [GM], distance harmonic mean [HM], median [M], area-adjusted median [Ma], median + extremum [Me], area-adjusted median + extremum [Mae] and minimum distance [Min]), and MAXENT. Model performance was assessed using kappa and area under curve (AUC) of the receiver operator characteristic. The influence of spatial range (area of occupancy) and environmental niches (marginality and tolerance) on modelling performance were also tested. MAXENT generally performed best, followed by ENFA-GM and -HM, DOMAIN, BIOCLIM, ENFA-M, -Min, -Ma, -Mae and -Me algorithms. Fish with clearly definable niches (i.e. high marginality) were most accurately modelled. Generally, Euclidean distance to nearest reef, HSI-b (backscatter), rugosity and maximum curvature were the most important variables in determining suitable habitat for the 5 demersal fish taxa investigated. This comparative study encourages ongoing use of presence-only approaches, particularly MAXENT, in modelling suitable habitat for demersal marine fishes.

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Accurate estimates of fish species occurrence are important to any species’ assessments and distribution model. With increasing emphasis on nondestructive sampling, underwater video techniques are commonly used without a thorough understanding of their advantages and disadvantages. This study compared data collected from baited remote underwater stereo-video systems (stereo BRUVS) and towed-video systems to determine; (1) the differences between these video techniques in terms of fish assemblages, functional groups (i.e. pelagic carnivore, epibenthic carnivore/omnivore or herbivore) and observability (i.e. conspicuous or cryptic), and (2) what impact do these two techniques have on the interpretation of spatially-explicit, predictive models. We found stereo BRUVS and towedvideo techniques recorded very different assemblages, functional groups and observability categories across structurally complex benthic biological habitats (i.e. macroalgae dominated habitats). However, as the habitat complexity became less (e.g. seagrass and areas with no visible macro-biota) both techniques appeared to provide similar fish assemblage information. We also found considerable differences in the predicted extents of habitat suitability between the two video techniques.

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Accurate estimates of fish species occurrence are important to any species’ assessments and habitat suitability model. However, surveys of marine fishes are often biased by method. Surveys of marine fishes are often biased by method. Such bias could influence the interpretation of any habitat suitability model. With increasing emphasis on non-destructive sampling, underwater video techniques are commonly used without a thorough understanding of their advantages and disadvantages. This study compared data collected from baited remote underwater stereo-video systems and towed-video systems to provide occurrence data to develop habitat suitability models of nine temperate marine fishes. While numerous studies have compared modelling approaches in terms of model performance (i.e. via AUC or Kappa) the point of this paper was to highlight how very sensiblelooking, well-performing (based on AUC) models can provide different predictions of habitat suitability depending on which dataset is used.