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31.
Short-term experiments were used to isolate the detrimental effects of grazer disturbance on young corals, and determine the
stage of development at which recruits are no longer susceptible to this disturbance. Artificial substrata containing an algal
matrix and coral recruits of different life stages were exposed to grazing by epilithic algal matrix (EAM) feeding combtoothed
blennies, Salarias fasciatus. Single polyp recruits were vulnerable to grazer disturbance, while multi-polyp recruits (ca. 6–8 polyps) survived with evidence of minor damage in the form of tissue and polyp loss. The result indicates that blennies,
although small and possessing weak dentition, can negatively influence the survival of young coral recruits. The protruding
structure of micro-nubbins, representing juvenile corals were not damaged, suggesting that coral achieving that size and form
can escape such damage.
Communicated by Ecology Editor Prof. Peter Mumby 相似文献
32.
A total of 211 poisoning incidents registered over the period 1990–2007 and affecting 294 Egyptian vultures (Neophron percnopterus) were studied to address the impact of poison-related mortality in the Spanish population. Poison-related mortality mainly
affected the birds on an individual level, with low numbers of individuals being found in each incident (mean 1.39) with 94.9%
being adults. Deaths were largely recorded (81.8%) during the breeding season, with mortality peaking during May and June
(52.1%). In contrast with other raptor species, a high proportion of adult individuals (74.2%) were found in the nest or its
surroundings. Age-related differences in the poisoning rate are probably related with different feeding and behavioral strategies
between age classes. The illegal use of poison to control predators was the main cause of mortality (93.8%), and particularly
in small hunting reserves (74.9%), since the kind of food resources that adults exploit are coincident with the type of baits
employed to illegally control predators and the preferred habitat coincides with areas of small game hunting. Our results
suggest that poisoning is probably one of the main causes of Egyptian vulture mortality in Spain. The eradication of the illegal
use of poisoning and supplementary feeding in specific territories to provide safe food seems priority for its conservation. 相似文献
33.
I.D. Ridgway A.C. Taylor E.S. Chang 《Journal of experimental marine biology and ecology》2006,339(2):135-147
For economic and logistical reasons, an increased proportion of landings from trawl caught Nephrops norvegicus is being used in the live export trade. This paper reports a series of trials that investigate the impact of capture method and trawl duration on the levels of stress, damage and mortality of N. norvegicus. The stress of N. norvegicus captured during trials in spring and autumn by means of short trawl (1 h duration), long trawl (5 h duration) and creeling was assessed using a range of physiological measures (for haemolymph l-lactate, crustacean hyperglycaemic hormone (CHH) and abdominal muscle glycogen concentrations), the immunological status (total haemocyte counts (THC)) and physical assessments (mortality, damage indices). N. norvegicus caught by creeling were generally less stressed (i.e. significantly lower haemolymph l-lactate and CHH concentrations) than their trawled counterparts. Increased duration of trawl did not significantly alter physiological parameters, while time of landing did have a significant effect on l-lactate concentrations, as individuals landed in the morning exhibited higher concentrations. Irrespective of the season in which trawling occurred, individuals captured by short trawls in the morning suffered lowest mortalities. Damage assessment data revealed that a greater proportion of individuals was categorised as heavily damaged following longer trawls conducted in spring. 相似文献
34.
Freddy Sitas Alison Gibberd Clare Kahn Marianne F. Weber May Chiew Rajah Supramaniam Louiza Velentzis Carolyn Nickson David P. Smith Dianne O’Connell Megan A. Smith Katie Armstrong Xue Qin Yu Karen Canfell Monica Robotin Eleonora Feletto Andrew Penman 《Cancer epidemiology》2013,37(6):780-787
BackgroundAustralia has one of the highest rates of cancer incidence worldwide and, despite improving survival, cancer continues to be a major public health problem. Our aim was to provide simple summary measures of changes in cancer mortality and incidence in Australia so that progress and areas for improvement in cancer control can be identified.MethodsWe used national data on cancer deaths and newly registered cancer cases and compared expected and observed numbers of deaths and cases diagnosed in 2007. The expected numbers were obtained by applying 1987 age–sex specific rates (average of 1986–1988) directly to the 2007 population. The observed numbers of deaths and incident cases were calculated for 2007 (average of 2006–2008). We limited the analyses to people aged less than 75 years.ResultsThere was a 28% fall in cancer mortality (7827 fewer deaths in 2007 vs. 1987) and a 21% increase in new cancer diagnoses (13,012 more diagnosed cases in 2007). The greatest reductions in deaths were for cancers of the lung in males (?2259), bowel (?1797), breast (?773) and stomach (?577). Other notable falls were for cancers of the prostate (?295), cervix (?242) and non-Hodgkin lymphoma (?240). Only small or no changes occurred in mortality for cancers of the lung (female only), pancreas, brain and related, oesophagus and thyroid, with an increase in liver cancer (267). Cancer types that showed the greatest increase in incident cases were cancers of the prostate (10,245), breast (2736), other cancers (1353), melanoma (1138) and thyroid (1107), while falls were seen for cancers of the lung (?1705), bladder (?1110) and unknown primary (?904).ConclusionsThe reduction in mortality indicates that prevention strategies, improvements in cancer treatment, and screening programmes have made significant contributions to cancer control in Australia since 1987. The rise in incidence is partly due to diagnoses being brought forward by technological improvements and increased coverage of screening and early diagnostic testing. 相似文献
35.
S. C. Wijers B. Y. M. van der Kolk A. E. Tuinenburg P. A. F. Doevendans M. A. Vos M. Meine 《Netherlands heart journal》2013,21(6):274-283
Purpose
Based on multiple large clinical trials conducted over the last decades guidelines for implantable cardioverter-defibrillator (ICD) implantations have been evolving. The increase in primary prophylactic ICD implantations challenges us to be critical towards the indications in certain patient populations.Methods
We retrospectively collected patient characteristics and rates of appropriate and inappropriate ICD therapy, appropriate and inappropriate ICD shock and mortality of all patients who received an ICD in the University Medical Center Utrecht (UMCU) over the years 2006–2011.Results
A total of 1075 patients were included in this analysis (74 % male, mean age 61 ± 13 years, left ventricular ejection fraction 30 ± 13 %); 61 % had a primary indication and 58 % had ischaemic heart disease. During a mean follow-up period of 31 ± 17 months, 227 of the patients (21 %) received appropriate ICD therapy (149 (14 %) patients received an appropriate ICD shock). Females, patients with a primary prophylactic indication and patients with non-ischaemic heart disease experienced significantly less ICD therapy. Only a few patients (54, 5 %) received inappropriate ICD therapy; 33 (3 %) patients received an inappropriate ICD shock. Fifty-five patients died within one year after ICD implantation and were therefore, in retrospect, not eligible for ICD implantation.Conclusion
Our study confirms the benefit of ICD implantation in clinical practice. Nevertheless, certain patients experience less benefit than others. A more patient-tailored risk stratification based on electrophysiological parameters would be lucrative to improve clinical benefit and cost-effectiveness. 相似文献36.
FrancisLEMCKERT 《动物学报》2005,51(3):393-400
在澳大利亚新南威尔士南部沿海,作者搜集了一个池塘繁殖的斑索蟾(Crinia signifera)的种群统计资料。通过捕捉进出池塘的1 612只个体,获得种群大小、结构、生长率、性成熟时的大小和年龄、死亡率及寿命资料。迁移高峰从6月持续到11月,蛙的最高、最低遇见数量分别出现在春季和秋季。但第2年,该池塘蛙的数量明显减少,可能是由于补充到种群中的幼体数量很少的缘故。6个月后个体的重捕率很低;但距第一次捕获18个月以后,仍有个别个体再次被捕获。性成熟时,雌性比雄性的身体大一些。生长曲线显示,雌性比雄性的生长更快,所以更早地达到性成熟。研究种群的数量、结构和死亡率趋势等与已知的其它Crinia signifera种群基本一致。但研究种群迁移活动的高峰出现较晚,并且夏季的活动水平明显很高。这种长的活动时间可能会导致存活率的下降,同时有利于选择迅速性成熟的雌性[动物学报51 (3) : 393 -400 , 2005]。 相似文献
37.
Karen L. Overholtzer-McLeod 《Coral reefs (Online)》2005,24(2):283-291
Understanding the dynamics of open marine populations is inherently complex, and this complexity has led to decades of debate regarding the relative importance of pre- versus post-settlement processes in structuring these populations. Movement between patches may be an important modifier of patterns established at settlement, yet local immigration and emigration have received less attention than other demographic rates. I examined loss rates from tagged populations of juvenile wrasses (yellowhead wrasse Halichoeres garnoti and bluehead wrasse Thalassoma bifasciatum) at two sites in the Bahamas. Assuming that all losses were due solely to mortality would have significantly underestimated survivorship of yellowhead wrasse by 29% and bluehead wrasse by 14%. On average, per capita mortality and emigration rates were higher for yellowhead than bluehead wrasse, but neither demographic rate differed between sites for either species. With respect to within-species density, bluehead wrasse mortality was density-dependent at the patch reef site, but mortality rates of yellowhead wrasse were consistently density-independent. Evaluating the effects of between-species density, yellowhead wrasse mortality increased with a decrease in bluehead wrasse density, but this effect was limited to the patch reef site. Emigration rates were not a function of either within-species or between-species density, but instead varied inversely with isolation distance. Numerous previous studies of coral-reef fish, conducted on patch reefs separated by only a few meters of sand and often using untagged fish, may have confounded losses due to emigration with those due to mortality. A better understanding of the factors affecting emigration in marine fishes is important to their effective management using spatial tools such as marine protected areas. 相似文献
38.
Mary Leighton 《Ethnos》2013,78(1):78-101
Death and the bodies of the dead are managed and handled in contemporary Western society by various professions that include archaeology. The bodies of the dead exist in a variety of material forms, and generate conflicting responses from the archaeologists who work with them. Positioning archaeologists as professionals within a wider society, this article explores the relationship between the physicality of the body, the (de)construction of personhood and the problem of mortality in contemporary Western (British) society. 相似文献
39.
40.
M. K. Mukerji 《Population Ecology》1973,15(2):50-63
Summary The relationship of ‘mean crowding’ to mean density showed that counts of nymphs and adults of the tarnished plant bug,Lygus lineolaris (Beauv.), on birdsfoot trefoil were aggregated and that the index of basic contagion approached zero for each developing stage. Aggregation
increased gradually from the first to the fourth instar and then decreased through the adult stage. The mortality process
from the first to the fifth instar was inversely density dependent.
Inter-sample variance was the major source of population variance although significant variance was occasionally associated
with blocks and plots owing to heterogeneity of the host stand. The most appropriate sample unit was a 3 sq. ft. area of foliage
and substrate. This was divided into four quarters; application of the variance component technique indicated that in most
cases one quarter drawn at random was optimal for sampling different stages. The number of samples required to attain a given
level of precision varied inversely with population density. The cost function for sampling was determined for specified levels
of precision. 相似文献