10 research outputs found

    Habitat partitioning and vulnerability of sharks in the Great Barrier Reef Marine Park

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    Sharks present a critical conservation challenge, but little is known about their spatial distribution and vulnerability, particularly in complex seascapes such as Australia's Great Barrier Reef Marine Park (GBRMP). We review (1) the distribution of shark species among the primary habitats of the GBRMP (coral reefs, inshore/shelf, pelagic and deep-water habitats) (2) the relative exploitation of each species by fisheries, and (3) how current catch rates interact with their vulnerability and trophic index. Excluding rays and chimaeras, we identify a total of 82 shark species in the GBRMP. We find that shark research in the GBRMP has yielded little quantitative information on most species. Reef sharks are largely site-fidelic, but can move large distances and some regularly use non-reef habitats. Inshore and shelf sharks use coastal habitats either exclusively or during specific times in their life cycle (e.g. as nurseries). Virtually nothing is known about the distribution and habitat use of the GBRMP's pelagic and deep-water sharks. At least 46 species (53.5 %) are caught in one or more fisheries, but stock assessments are lacking for most. At least 17 of the sharks caught are considered highly vulnerable to exploitation. We argue that users of shark resources should be responsible for demonstrating that a fishery is sustainable before exploitation is allowed to commence or continue. This fundamental change in management principle will safeguard against stock collapses that have characterised many shark fisheries

    Sinorhizobium fredii HH103 cgs Mutants Are Unable to Nodulate Determinate- and Indeterminate Nodule–Forming Legumes and Overproduce an Altered EPS

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    Sinorhizobium fredii HH103 produces cyclic P glucans (CG) composed of 18 to 24 glucose residues without or with 1-phosphoglycerol as the only substituent. The S. fredii HH103-Rifr cgs gene (formerly known as ndvB) was sequenced and mutated with the lacZ-gentamicin resistance cassette. Mutant SVQ562 did not produce CG, was immobile, and grew more slowly in the hypoosmotic GYM medium, but its survival in distilled water was equal to that of HH103-Rifr. Lipopolysaccharides and K-antigen polysac-charides produced by SVQ562 were not apparently altered. SVQ562 overproduced exopolysaccharides (EPS) and its exoA gene was transcribed at higher levels than in HH103-Rifr. In GYM medium, the EPS produced by SVQ562 was of higher molecular weight and carried higher levels of sub-stituents than that produced by HH103-Rifr. The expression of the SVQ562 cgs::lacZ fusion was influenced by the pH and the osmolarity of the growth medium. The S. fredii cgs mutants SVQ561 (carrying cgs and SVQ562 only formed pseudonodules on Glycine max (determinate nodules) and on Glycyrrhiza uralensis (indeterminate nodules). Although nodulation factors were detected in SVQ561 cultures, none of the cgs mutants induced any macroscopic response in Vigna unguiculata roots. Thus, the nodulation process induced by S. fredii cgs mutants is aborted at earlier stages in V. unguiculata than in Glycine max.</p

    Assessing the Perceptions of Fibromyalgia Syndrome in United States Among Academic Physicians and Medical Students: Where are We and Where are We Headed?

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    Objectives: Fibromyalgia syndrome [FMS] is a common condition, often diagnosed in the primary care setting, causing diffuse pain with additional somatic symptoms. Many physicians have questioned the existence of FMS due to an unclear pathophysiological origin and its overlap with other somatic syndromes. We sought to assess the perceptions of FMS among United States medical students and internal medicine and family medicine trained physicians working in an academic hospital. Methods: Residents and attendings working in a local teaching hospital were given questionnaires during undergraduate medical education sessions and academic conferences in internal medicine and family medicine. Medical students received surveys during small group sessions and through student mailboxes. Results: Seventy-two internal and family medicine trained physicians and 211 medical students were surveyed. In assessing whether FMS was primarily physiological or psychological in origin, 66% of physicians compared to only 29% of medical students [p < 0.001] chose a psychological etiology. Among physicians, women [82%] and American medical graduates [77%] were more likely to endorse a psychological mechanism than their counterparts [53% p < 0.010, 50% p = 0.022, respectively]. Additionally, when physicians were asked whether they believed FMS was an "actual illness," 19% responded "no." Conclusions: Fibromyalgia syndrome continues to be a controversial illness in the United States, especially when compared with values attained from international studies. Although current academic physicians appear to be skeptical of FMS's existence or its potential physiological mechanisms, medical students are more likely to support a physiological mechanism

    Review of the life history characteristics, ecology and fisheries for deep-water tropical demersal fish in the Indo-Pacific region

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    © 2016, Her majesty the Queen in Right of Australia.Deep-water tropical fishes support locally significant commercial fisheries, high value recreational fisheries, and culturally and economically important artisanal and subsistence fisheries throughout the Indo-Pacific region. The main species captured by these fisheries are deep-water snappers (Lutjanidae), groupers (Epinephelidae), and emperors (Lethrinidae). Quantitative assessments of deep-water tropical fisheries have been limited by a lack of adequate biological and fisheries data. We review the biology and ecology of deep-water tropical fishes, discuss the implications for assessment and management of tropical deep-water fisheries, and provide perspectives on future research priorities. We found that biological and fisheries information is lacking for the majority of deep-water tropical fishes. Furthermore, many studies were constrained by low samples sizes and the use of methods that have not been validated or verified. Most species for which reliable information was available were reported to have extended longevities (&gt;20 years), low rates of natural mortality (M &lt; 0.15), and slow to modest growth rates (K = 0.12–0.25). These life history traits indicate a low production potential for many deep-water tropical fishes, and suggest that sustainable exploitation rates and potential yields may be low. There is a need for more representative and adequate studies of deep-water tropical fishes and for improved fisheries data collection and the use of consistent methods in addition to information sharing to facilitate the development of robust data-poor assessment techniques for these species
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