996 resultados para marine hydrokinetic devices


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When the availability of sperm limits female reproductive success, competition for sperm, may be an important broker of sexual selection. This is because sperm limitation can increase the variance in female reproductive success, resulting in strong selection on females to compete for limited fertilization opportunities. Sperm limitation is probably common in broadcast-spawning marine invertebrates, making these excellent candidates for investigating scramble competition between broods of eggs and its consequences for female reproductive success. Here, we report our findings from a series of experiments that investigate egg competition in the sessile, broadcast-spawning polychaete Galeolaria caespitosa. We initially tested whether the order in which eggs encounter sperm affects their fertilization success at two ecologically relevant current regimes. We used a split-clutch-split-ejaculate technique to compare the fertilization success of eggs from individual females that had either first access (competition-free treatment) or second access (egg competition treatment) to a batch of sperm. We found that fertilization success depended on the order in which eggs accessed sperm; eggs that were assigned to the competition-free treatment exhibited significantly higher fertilization rates than those assigned to the egg competition treatment at both current speeds. In subsequent experiments we found that prior exposure of sperm to eggs significantly reduced both the quantity and quality of sperm available to fertilize a second clutch of eggs, resulting in reductions in fertilization success at high and low sperm concentrations. These findings suggest that female traits that increase the likelihood of sperm-egg interactions (e.g. egg size) will respond to selection imposed by egg competition.

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In marine invertebrates, the larval and adult stages of many species are often ecologically distinct and as consequence these stages have been traditionally been viewed as physiologically separate. More recently, we have begun to recognize that metamorphosis does not represent a new beginning and events during the larval stage can influence adult performance. I will discuss recent work that suggests that the links between life-history stages are even more pervasive than we currently appreciate. For several species of marine invertebrate, I have found that events during one generation can strongly affect performance in the subsequent generation and events during the haploid phase can affect performance in the diploid phase. All of these links are mediated by changes in offspring size or offspring quality. I will discuss the implication of these strong links for the way we view the ecology of marine invertebrates and the evolution of offspring size in this group.

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The genera Lobatocreadium, Pseudocreadium, Hypocreadium and Dermadena are redefined and host lists given. Provisional keys to species of Lobatocreadium, Hypocreadium and Dermadena are presented. The following species are described from (1) the Great Barrier Reef: Lobatocreadium exiguum from Balistapus undulatus and Sufflamen bursa; Hypocreadium cavum n. sp. from Abalistes stellatus (type-host) and Cantheschenia grandisquamis; H. grandisquamis n. sp. from Cantheschenia grandisquamis; Dermadena spatiosa n. sp, from Cantheschenia grandisquamis; and (2) southwestern Australia: D. stirlingi n. sp. from Meeschenia hippocrepis. The following new combinations are made: Lobatocreadium vitellosum (Ozaki, 1936) n. comb. (originally Leptocreadium); Hypocrendium balistes (Nagaty, 1942) n. comb. (originally Pseudocreadium); H. biminensis (Sogandares-Bernal, 1959) n. comb. (originally Pseudocreadium); H. indicum (Madhavi, 1972) n. comb. (originally Pseudocreadium); and H. galapagoensis (Manter, 1945) n. comb. (originally Pseudocreadium). Several nominal species of Pseudocreadium and Hypocreadium are considered incertae sedis.

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Telecanthus, the lateral displacement of the medial canthus, can be a congenital deformity or can occur after facial trauma or tumor resection. Treatment of telecanthus remains a challenge for plastic surgeons. For proper correction, it is necessary to shift the medial canthus medially, fixing its tendon to the bone. The ideal technique would allow easy, safe, and stable fixation of the tendon, permit a unilateral approach with minimal incisions, and be cost-effective. The purpose of this study was to evaluate the feasibility and results (immediate and long-term) of medial telecanthus repair using ipsilateral titanium microanchor fixation. Nine patients, 7 with unilateral telecanthus and 2 with bilateral telecanthus, underwent ipsilateral canthopexy involving a microanchor device. Anthropometric measurements of the orbital regions were taken before, immediately after, and at 1 year after surgery. Data for the affected sides were compared with those for the unaffected sides, and the evolution of those values was assessed throughout the 1-year follow-up period. For all patients, the final values were lower than those initially obtained. At 1 year after surgery, the intercanthal distance was reduced to age-adjusted normal values in all cases. On the operated side, stable improvement was observed in terms of the distance from the medial canthus to the midline, although some degree of recurrence was noted in most of the patients. The use of a microanchor system for medial canthopexy can be considered an easily performed and effective option for treating canthal dystopia, especially when an ipsilateral approach is preferred.

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The novel bicyclic lipid, dictyosphaerin (1), has been isolated from the southern Australian marine green alga Dictyosphaeria sericea. The molecular structure for 1 was secured by chemical derivatization and detailed spectroscopic analysis.

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The genera Preptetos Pritchard, 1960 and Neopreptetos Machida, 1982 are redefined. The following species are described and/or recorded from marine fishes. From the Great Barrier Reef: Preptetos caballeroi Pritchard, 1960 in Naso annulatus, N. brevirostris and N. vlamingii; P. xesuri (Yamaguti, 1940) in Zebrasoma veliferum and Z.scopas; Preptetos cannoni Barker, Bray et Cribb, 1993 in Siganus doliatus and S. fuscescens; Preptetas luguncula sp. n. in Naso unicoris (type-host); P. impar sp. n. in Lutjanus erythropterus (type-host) and L. malabaricus; Neopreptetos arursettae Machida, 1982 in Pomacanthus semicirculatus; and N. kurochkini (Toman, 1989) in Chaetodontoplus meredithi. From southwestern Australia: Preptetos rotto sp. n. in Nelusetta ayraudi (type-host), Neosebastes pandus, Oplegnathus woodwardi and Pagrus auratus. The new combination Preptetos trulla (Linton, 1907) (originally Distormum then Lepocreadium) is made and the species Lepocreadium areolatum (Linton, 1900) is considered likely to belong in Preptetos.

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Biologic valve re-replacement was examined in a series of 1343 patients who underwent aortic valve replacement at The Prince Charles Hospital, Brisbane, with a cryopreserved or 4 degrees C stored allograft valve or a xenograft valve, A parametric model approach was used to simultaneously model the competing risks of death without re-replacement and re-replacement before death, One hundred eleven patients underwent a first re-replacement for a variety of reasons (69 patients with xenograft valves, 28 patients with 4 degrees C stored allograft valves, and 14 patients with cryopreserved allograft valves), By multivariable analysis younger age at operation was associated with xenograft, 4 degrees C stored allograft, and cryopreserved allograft valve re-replacement, However, this effect was examined in the context of longer survival of younger patients, which increases their exposure to the risk of re-replacement as compared with that in older patients whose decreased survival reduced their probability of requiring valve re-replacement, In patients older than 60 years at the time of aortic valve replacement, the probability of re-replacement (for any reason) before death was similar for xenografts and cryopreserved allograft valves but higher for 4 degrees C stored valves, However, in patients younger than 60 years, the probability of re-replacement at any time during the remainder of the life of the patient was lower with the cryopreserved allograft valve compared with the xenograft valve and 4 degrees C stored allografts.

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A specimen of the sponge Callyspongia sp. collected off the coast of New South Wales, Australia, has yielded the novel lipid (6Z,9Z,12Z,15Z)-1, 6, 9, 12, 15-octadecapenten-3-one, together with (4Z,7Z,10Z,13Z)-4, 7, 10, 13-hexadecatetraenoic acid.

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The following lepocreadiid species are described from Cheilodactylidae from south-western Australia. Cliveus peroni n. g., n. sp, from Nemadactylus valenciennesi is characterised by its attenuated forebody and C. acaenodera n. sp. from Dactylophora nigricans by its attenuated forebody, the pattern of forebody spination and the large cirrus-sac. Jericho chojeri n. g., n. sp. from N. valenciennesi has a large infundibuliform oral sucker and paired ani. Rugocavum n. g. is distinguished by the possession of a blind, wrinkled glandular pit on the postero-ventral surface of the forebody. R. nemadactyli n. sp. from N. valenciennesi has its vitelline field restricted to the hindbody, whereas in R. morwong n. sp, from N. valenciennesi the vitelline field reaches into the forebody. Paraneocreadium australiense Kruse, 1978 from N. valenciennesi is redescribed and its coiled internal seminal vesicle and lobed gonads are considered distinctive features. Scaphatrema nemadactyli (Kurochkin & Korotaeva, 1972) n. g., n. comb. from N. valenciennesi has a wrinkled, boat-shaped body, a 'Lepidapedon-like' cirrus-sac and multiple testes; it was originally placed in the genus Multitestis, but these characters suggest that a new genus should be erected for it within the subfamily Lepidapedinae.

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The whale shark is the largest fish in the ocean, A tourism industry based on interacting with whale sharks has developed recently in Ningaloo Marine Park, off the coast of Western Australia, This is the only known, accessible place in the world where whale sharks congregate in significant numbers, Results from surveys of participants in the 'whale shark experience' are reported, with the experience found to be extremely satisfying for most consumers, Yet management questions relating to diver-to-shark separation distances, the appropriate number of operators, and the use of regulation, self-regulation and economic instruments, remain, The nexus between experiential aspects of the whale shark attraction and such management concerns is examined, and the usefulness of appropriate research in resolving management questions established, It is concluded that a judicious combination of management approaches is required to ensure the sustainable development of the whale shark tourism industry. (C) 1997 Elsevier Science Ltd.

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The biomimetic synthesis of novel lipids 1, 2, 8 and 10 obtained from the southern Australian marine brown alga Notheia anomala has been achieved, and features the acid mediated conversion of methylene interrupted bisepoxides to tetrahydrofurans. (C) 1997 Elsevier Science Ltd.

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Background. Several medical devices used during hemodynamic procedures, particularly angiographic diagnostic and therapeutic cardiac catheters, are manufactured for single use only. However, reprocessing and reuse of these devices has been reported, to determine the frequency of reuse and reprocessing of single-use medical devices used during hemodynamic procedures in Brazil and to evaluate how reprocessing is performed. Design. National survey, conducted from December 1999 to July 2001. Methods. Most of the institutions affiliated with the Brazilian Society of Hemodynamic and Interventional Cardiology were surveyed by use of a questionnaire sent in the mail. Results. The questionnaire response rate was 50% (119 of 240 institutions). Of the 119 institutions that responded, 116 (97%) reported reuse of single-use devices used during hemodynamic procedures, and only 26 (22%) reported use of a standardized reprocessing protocol. Cleaning, flushing, rinsing, drying, sterilizing and packaging methods varied greatly and were mostly inadequate. Criteria for discarding reused devices varied widely. Of the 119 institutions that responded, 80 (67%) reported having a surveillance system for adverse events associated with the reuse of medical devices, although most of these institutions did not routinely review the data, and only 38 (32%) described a training program for the personnel who reprocessed single-use devices. Conclusions. The reuse of single-use devices used during hemodynamic procedures was very frequent in hospitals in Brazil. Basic guidance on how to reuse and reprocess single-use medical devices is urgently needed, because, despite the lack of studies to support reusing and reprocessing single-use medical devices, such devices are necessary in limited-resource areas in which these practices are current.

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Purpose: To compare the ability of Subjective assessment of optic nerve head (ONH) and retinal nerve fiber layer (RNFL) by general ophthalmologists and by a glaucoma expert with objective measurements by optical coherence tomography (Stratus OCT, Carl Zeiss Meditec Inc), confocal scanning laser ophthalmoscope (HRT III; Heidelberg Engineering, Heidelberg. Germany), and scanning laser polarimetry (GDx enhanced corneal compensation; Carl Zeiss Meditec Inc, Dublin, CA) in discriminating glaucomatous and normal eyes. Methods: Sixty-one glaucomatous and 57 normal eyes or 118 subjects Were included in the study. Three independent general ophthalmologists and I glaucoma expert evaluated ONH stereo-photographs. Receiver operating characteristic curves were constructed for each imaging technique and sensitivity at fixed specificity was estimated. Comparisons or areas under these curves (aROCs) and agreement (k) were determined between stereophoto grading and best parameter from each technique. Results: Best parameter from each technique showed larger aROC (Stratus OCT RNFL 0.92; Stratus OCT ONH vertical integrated area = 0.86; Stratus OCT macular thickness = 0.82; GDx enhanced corneal compensation = 0.91, HRT3 global cup-to-disc ratio = 0.83; HRT3 glaucoma probability score numeric area score 0.83) compared with stereophotograph grading by general ophthalmologists (0.80) in separating glaucomatous and normal eyes. Glaucoma expert stereophoto grading provided equal or larger aROC (0.92) than best parameter of each computerized imaging device. Stereophoto evaluated by a glaucoma expert showed better agreement with best parameter of each quantitative imaging technique in classifying eyes either as glaucomatous or normal compared with stereophoto grading by general ophthalmologists, The combination Of Subjective assessment of the optic disc by general ophthalmologists with RNFL objective parameters improved identification of glaucoma patients in a larger proportion than the combination of these objective parameters with Subjective assessment of the optic disc by a glaucoma expert (29.5% vs. 19.7%, respectively). Conclusions: Diagnostic ability of all imaging techniques showed better performance than subjective assessment of the ONH by general ophthalmologists, but not by It glaucoma expert, Objective RNFL measurements may provide improvement in glaucoma detection when combined with subjective assessment of the optic disc by general ophthalmologists or by a glaucoma expert.