407 resultados para Fish-culture
Resumo:
1. The ability of many introduced fish species to thrive in degraded aquatic habitats and their potential to impact on aquatic ecosystem structure and function suggest that introduced fish may represent both a symptom and a cause of decline in river health and the integrity of native aquatic communities. 2. The varying sensitivities of many commonly introduced fish species to degraded stream conditions, the mechanism and reason for their introduction and the differential susceptibility of local stream habitats to invasion because of the environmental and biological characteristics of the receiving water body, are all confounding factors that may obscure the interpretation of patterns of introduced fish species distribution and abundance and therefore their reliability as indicators of river health. 3. In the present study, we address the question of whether alien fish (i.e. those species introduced from other countries) are a reliable indicator of the health of streams and rivers in south-eastern Queensland, Australia. We examine the relationships of alien fish species distributions and indices of abundance and biomass with the natural environmental features, the biotic characteristics of the local native fish assemblages and indicators of anthropogenic disturbance at a large number of sites subject to varying sources and intensities of human impact. 4. Alien fish species were found to be widespread and often abundant in south-eastern Queensland rivers and streams, and the five species collected were considered to be relatively tolerant to river degradation, making them good candidate indicators of river health. Variation in alien species indices was unrelated to the size of the study sites, the sampling effort expended or natural environmental gradients. The biological resistance of the native fish fauna was not concluded to be an important factor mediating invasion success by alien species. Variation in alien fish indices was, however, strongly related to indicators of disturbance intensity describing local in-stream habitat and riparian degradation, water quality and surrounding land use, particularly the amount of urban development in the catchment. 5. Potential confounding factors that may influence the likelihood of introduction and successful establishment of an alien species and the implications of these factors for river bioassessment are discussed. We conclude that the potentially strong impact that many alien fish species can have on the biological integrity of natural aquatic ecosystems, together with their potential to be used as an initial basis to find out other forms of human disturbance impacts, suggest that some alien species (particularly species from the family Poeciliidae) can represent a reliable 'first cut' indicator of river health.
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This paper reports the results of a mixed method approach to answer: To what extent do cultural values impact on e-service use in Saudi Arabia, and if so how? This paper will firstly, introduce the importance of culture and define the aspects of Saudi culture with focus on our scope: the need for Service Oriented Culture. It will then, briefly, describe the method used and present the qualitative and quantitative findings related to the need for Service Oriented Culture. This research aims to cover a gap in the literature by investigating to what extent the presence of Service Oriented Culture, as one of Saudi Arabia’s cultural values, impacts on e-service use in Saudi Arabia. Surprisingly, the tested hypothesis was rejected: the presence of Service Oriented Culture is not a positive predictor of Intention to Use e-services in Saudi Arabia. It is evidenced that consideration of the impact of the cultural values will mainly contribute to the enhancement of ICTs implementation and use.
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This research proposed a new framework for safety culture and examined the influence that culture has on safety in the heavy vehicle industry. The results gave evidence for an industry wide culture, allowing future safety interventions to be designed in a culturally-relevant manner. Designing culturally-relevant interventions may maximise their effectiveness and reduce the levels of resistance to safety that have been evident in past years.
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Introduction: Relatively few attempts have been made to describe and understand women’s alcohol consumption beyond adolescence and young adulthood. In particular, there has been a lack of studies focusing on the alcohol culture that surrounds and guides mature-aged women’s drinking. As part of a larger cross-national comparison, the present study sought to address this gap by identifying the shared beliefs and values that impact on drinking outcomes among mature-aged women in Sweden and Australia. Method: The study was guided by an ethnographic methodology. To generate data, a series of semi-structured interview were conducted with 17 Australian (age = 45-57 years; M = 52.1, SD = 3.9) and 19 Swedish (age = 45-58 years; M = 52.2, SD = 4.8) women. All interviews were transcribed verbatim and thematically analysed. Results: With age, the focus of alcohol as a single purpose vehicle for intoxication had given way to a focus on the enjoyment and ritual of drinking itself; taste had become increasingly important and alcohol was strongly associated with pleasurable environments and experiences. The view of alcohol as a taste experience was particularly pronounced among the Swedish women, with alcohol (most commonly wine) often seen as inseparable from food. Among the Swedish women, this view of alcohol was also associated with a strong de-emphasis of the pharmacological effects of alcohol. In contrast, several Australian women understood and used alcohol as relief for anxiety and stress. Moderate drinking was linked to the social construction of both age and gender in the two samples, while heavy or abusive alcohol consumption was associated with strong proscriptive norms and stigma. Conclusions: Australian and Swedish women share a number of beliefs and values around alcohol, however, these findings also show unique country-level differences. Implications for drinking outcomes are discussed.
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The routine cultivation of human corneal endothelial cells, with the view to treating patients with endothelial dysfunction, remains a challenging task. While progress in this field has been buoyed by the proposed existence of progenitor cells for the corneal endothelium at the corneal limbus, strategies for exploiting this concept remain unclear. In the course of evaluating methods for growing corneal endothelial cells, we have noted a case where remarkable growth was achieved using a serial explant culture technique. Over the course of 7 months, a single explant of corneal endothelium, acquired from cadaveric human tissue, was sequentially seeded into 7 culture plates and on each occasion produced a confluent cell monolayer. Sample cultures were confirmed as endothelial in origin by positive staining for glypican-4. On each occasion, small cells, closest to the tissue explant, developed into a highly compact layer with an almost homogenous structure. This layer was resistant to removal with trypsin and produced continuous cell outgrowth during multiple culture periods. The small cells gave rise to larger cells with phase-bright cell boundaries and prominent immunostaining for both nestin and telomerase. Nestin and telomerase were also strongly expressed in small cells immediately adjacent to the wound site, following transfer of the explant to another culture plate. These findings are consistent with the theory that progenitor cells for the corneal endothelium reside within the limbus and provide new insights into expected expression patterns for nestin and telomerase within the differentiation pathway.
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This is a case study of a young university striving to generate and sustain a vibrant Research Training culture. The university’s research training framework is informed by a belief in a project management approach to achieving successful research candidature. This has led to the definition and reporting of key milestones during candidature. In turn, these milestones have generated a range of training programs to support Higher Degree Research (HDR) students to meet these milestones in a timely fashion. Each milestone focuses on a specific set of skills blended with supporting the development of different parts of the doctoral thesis. Data on student progress and completion has provided evidence in highlighting the role that the milestones and training are playing in supporting timely completion. A university-wide reporting cycle generated data on the range of workshops and training provided to Higher Degree Research students and supervisors. The report provided details of thesis topic and format, as well as participation in research training events and participant evaluation of those events. Analysis of the data led to recommendations and comments on the strengths and weaknesses of the current research training program. Discussion considered strategies and drivers for enhancements into the future. In particular, the paper reflects on the significant potential role of centrally curated knowledge systems to support HDR student and supervisor access, and engagement and success. The research training program was developed using blended learning as a model. It covered face-to-face workshops as well as online modules. These were supplemented by web portals that offered a range of services to inform and educate students and supervisors and included opportunities for students to interact with each other. Topics ranged from the research life cycle, writing and publication, ethics, managing research data, managing copyright, and project management to use of software and the University’s Code of Conduct for Research. The challenges discussed included: How to reach off campus students and those studying in external modes? How best to promote events to potential participants? How long and what format is best for face-to-face sessions? What online resources best supplement face-to-face offerings? Is there a place for peer-based learning and what form should this take? These questions are raised by a relatively young university seeking to build and sustain a vibrant research culture. The rapid growth in enrolments in recent years has challenged previous one-to-one models of support. This review of research training is timely in seeking strategies to address changing research training support capacity and student needs. Part of the discussion will focus on supervisory training, noting that good supervision is the one remaining place where one-to-one support is provided. Ensuring that supervisors are appropriately equipped to address student expectations is considered in the context of the research training provisions. The paper concludes with reflection on the challenges faced, and recommended ways forward as the number of research students grows into the future.
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Increasingly, the library and information science (LIS) practitioner is being challenged to incorporate research into the context of their professional work. This paper reports on the Researcher-Librarian Partnership, a research-mentoring program that was initiated by the International Federation of the Library Association and Institutions. Six new LIS practitioners within their first seven years of professional practice took part in the program. Each was partnered with an experienced LIS researcher who provided mentoring and support. During the 12-month program the new professionals designed and implemented a research project on a topic of interest. This paper outlines the details of the program providing observations on how research mentoring can be a powerful way to ensure all stakeholders – practitioners, educators and professional associations – can plan an active role in supporting the development of a research culture within the profession.
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The effects of a range of different sublethal salinities were assessed on physiological processes and growth performance in the freshwater ‘tra’ catfish (Pangasianodon hypophthalmus) juveniles over an 8-week experiment. Fish were distributed randomly among 6 salinity treatments [2, 6, 10, 14 and 18 g/L of salinity and a control (0 g/L)] with a subsequent 13-day period of acclimation. Low salinity conditions from 2 to 10 g/L provided optimal conditions with high survival and good growth performance, while 0 g/L and salinities[14 g/L gave poorer survival rates (p\0.05). Salinity levels from freshwater to 10 g/L did not have any negative effects on fish weight gain, daily weight gain, or specific growth rate. Food conversion ratio, however, was lowest in the control treatment (p\0.05) and highest at the maximum salinities tested (18 g/L treatment). Cortisol levels were elevated in the 14 and 18 g/L treatments after 6 h and reached a peak after 24-h exposure, and this also led to increases in plasma glucose concentration. After 14 days, surviving fish in all treatments appeared to have acclimated to their respective conditions with cortisol levels remaining under 5 ng/ mL with glucose concentrations stable. Tra catfish do not appear to be efficient osmoregulators when salinity levels exceed 10 g/L, and at raised salinity levels, growth performance is compromised. In general, results of this study confirm that providing culture environments in the Mekong River Basin do not exceed 10 g/L salinity and that cultured tra catfish can continue to perform well.
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The Weberian sense of work and life suggests that working is something around which the rest of life flows. Moreover, work life and domestic life have been defined as separate for most people based on physical structures. That is, being physically in a building at work limited your ability to interact with those who are not nearby – not part of work. As such, social conventions regarding the uses of media at work have become part of our cultural sensibilities – we “know” it is not proper to have romantic discourse over the office phone, much less romance during work! Doing so becomes news. Yet, despite the construction of such distinctions, these workspaces and places have always been difficult to render as such. For example, one might consider the relatively recent development of teleworking from the 1980s or the “putting out system”[1] which dates back to the 1400s – both requiring work in the home. The papers in this special issue draw our attention to some of the ethical issues raised by the growing pervasiveness of information and communications technologies (ICTs) in our everyday lives and the fact that it is becoming increasingly difficult to make distinctions between being somewhere (like work) and being away from some things (like one’s friends, social interests and other parts of life that are not integrated into this space or place [2] )...
Resumo:
The Third Sector is experiencing unprecedented change as nonprofit organisations pursue their mission, organisational excellence and sustainability. This research collected data from employees of Australian nonprofit human service organisations. Instruments to measure organisational culture and change readiness were validated. The relationships between perceptions of organisational cultures, change readiness, job satisfaction and intentions to leave were explored. Findings indicate flexible organisational cultures influence employee attitudes more positively than control cultures. It identified that leaders have a significant role to play in developing and fostering change readiness and job satisfaction. This improves employees' adaptation to change, increases staff retention and organisational sustainability.
Resumo:
Thraustochytrids have become of considerable industrial and scientific interest in the past decade due to their health benefits. They have been proven to be the principle source in marine and estuarine fish diets with high percentage of long chain (LC) or polyunsaturated fatty acids (PUFA). Therefore, the oil extracted from fish for human document.forms[0].elements[13].select();consumption is rich in PUFA with high omega-3 fatty acid content. Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) of all of the omega-3 fatty acids, are considered beneficial essential oils for humans with a wide range of health benefits. These include brain and neural development in infants, general wellbeing of adults and drug delivery through precursor molecules. They have become one of the most extensively studied organisms for industrial oil preparations as PUFA extraction from fish becomes less profitable. Many forms of these Thraustochytrid oils are being trialled for human consumption all over the world. In Australia, there has been little research performed on these organisms in the past ten years. A few Australian studies have been conducted in the form of comparative studies related to PUFA production within the related genera, but not focussed on their identification or cellular and genomic characterisation. Therefore, the main aim of this study was to investigate the morphological and genetic characteristics of Australian Thraustochytrids in order to aid in their identification and characterisation, as well as to better understand the effect of environmental conditions in the regulation of PUFA production. It was also noted that there was a knowledge gap in the preservation and total genomic DNA extraction of these organisms for the purposes of scientific research. The cryopreservation of these organisms for studies around the world follows existing generic methods. However, it is well understood that many of these generic methods attract not only high costs for chemicals, but also uses considerable storage space and other resources, all of which can be improved with new or modified approaches. In this context, a simple and inexpensive bead preservation method is described, without compromising the storage shelf life. We also describe, for the first time, the effects of culture age on the successful cryopreservation of Thraustochytrids. It was evident in the literature that DNA and RNA extractions for molecular and genetic studies of Thraustochytrids follow the classical phenol-chloroform extraction methods. It was also observed that modern protocols failed to avoid the use of phenol-chloroform rather than improving preparation and cell disruption. In order to provide a high quantity and quality DNA extraction, a modified protocol has been introduced that employs the use of modern commercial extraction kits and standard laboratory equipment. Thraustochytrids have been shown to be highly conserved in their 18S rDNA gene sequences, which is used as the current standard for identification. It was demonstrated that the 18S rDNA gene sequence limits the recognition of closely related genera or within the genera from each member. Therefore, it was proposed that another profile, such as a randomly amplified polymorphic DNA (RAPD) based profiling system, be tested for use in the characterisation of Thraustochytrids. The RAPD profiles were shown to provide a unique DNA fingerprint for each isolate and small variations in their genome were able to be detected. This method involved the use of a minimum number of standard arbitrary primers and with an increase in the number of different primers used, a very high discrimination between organisms could be achieved. However, the method was not suitable for taxonomic purposes because the results did not correlate with other taxonomic features such as morphology. Another knowledge gap was found with respect to Australian Thraustochytrid growth characteristics, in that these had not been recorded and published. In order to rectify this, a record of colony and microscopic features of 12 selected isolates was performed. The results of preliminary studies indicated that further microbiological and biochemical studies are needed for full characterisation of these organisms. This information is of great importance to bio-prospecting of new Thraustochytrids from Australian ecosystems and would allow for their accurate identification, and so permit the prediction of their PUFA capability by comparison with related genera/species. It was well recognized that environmental stress plays a role in the PUFA production and is mainly due to the reactive oxygen species as abiotic stress (Chiou et al., 2001; Okuyama et al., 2008; Shabala et al., 2009; Shabala et al., 2001). In this aspect, this study makes the first attempt towards better understanding of this phenomenon by way of the use of real-time PCR for the detection of environmental effects on the regulation of PUFA production. Three main environmental conditions including temperature, pH and oxygen availability were monitored as stress inducers. In summary, this study provides novel approaches for the preservation and handling of Thraustochytrids, their molecular biological features, taxonomy, characterisation and responses to environmental factors with respect to their oil production enzymes. The information produced from this study will prove to be vital for both industrial and scientific investigations in the future.
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A review of Philip Glass's opera The Perfect American. The Brisbane Festival’s production of Philip Glass’s opera The Perfect American is only the third production of the 2012 work ever to be staged. That’s quite a coup for the Brisbane Festival and Opera Queensland. The Perfect American was commissioned by Madrid’s Teatro Real and London’s English National Opera to mark the American composer’s 75th birthday. Glass’s telling of the Disney myth focuses on the final stages of Walt Disney’s life and career – a high art critique of a popular culture icon...
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A travel article about a journey to the Cobourg Peninsula, Arnhem Land. "NOW I know I'm back,'' says our guide David McMahon as the scent of wood smoke makes its way into the 4WD. For McMahon, being back means Kakadu and Arnhem Land, and ultimately our final destination in the Northern Territory's Cobourg Peninsula. In the north, one of the first things you need to adjust is your attitude to fire. The indigenous people have long worked with it. The rangers perform controlled burns. The animals have adapted and know how to escape the flames. The smoke trail leads us down the old Jim Jim Rd, our first stretch of dirt track since leaving Darwin. Our destination is the Venture North campsite at Garig Gunak Barlu National Park...