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Mortality Levels (mortality + level)
Selected AbstractsSalmonid alphavirus (SAV) and pancreas disease (PD) in Atlantic salmon, Salmo salar L., in freshwater and seawater sites in Norway from 2006 to 2008JOURNAL OF FISH DISEASES, Issue 5 2010M D Jansen Abstract A cohort study was initiated in the spring of 2006 to investigate epidemiological aspects and pathogenesis of salmonid alphavirus (SAV) subtype 3 infections and pancreas disease (PD). The aims were to assess involvement of the freshwater production phase, the extent and frequency of subclinical infections and to follow PD-affected populations throughout the entire seawater production cycle, as well as investigate possible risk factors for PD outbreaks. Fish groups from 46 different Atlantic salmon freshwater sites in six counties were sampled once prior to seawater transfer and followed onto their seawater sites. A total of 51 Atlantic salmon seawater sites were included, and fish groups were sampled three times during the seawater production phase. SAV subtype 3 was not identified by real-time RT-PCR from samples collected in the freshwater phase, nor were any SAV-neutralizing antibodies or histopathological changes consistent with PD. In the seawater phase, SAV was detected in samples from 23 of 36 (63.9%) studied sites located within the endemic region. No SAV subtype 3 was detected in samples from seawater sites located outside the endemic region. The cumulative incidence of PD during the production cycle amongst sites with SAV detected was 87% (20 of 23 sites). Average fish weight at time of PD diagnosis ranged from 461 to 5978 g, because of a wide variation in the timing of disease occurrence throughout the production cycle. Mortality levels following a PD diagnosis varied greatly between populations. The mean percentage mortality was 6.9% (±7.06) (range 0.7,26.9), while the mean duration of increased mortality following PD diagnosis was 2.8 months (±1.11) (range 1,6). [source] Mortality patterns in infectious salmon anaemia virus outbreaks in New Brunswick, CanadaJOURNAL OF FISH DISEASES, Issue 11 2005K L Hammell Abstract Mortality levels attributed to infectious salmon anaemia viral (ISAV) infections were examined at the net pen and site level in the 1996 smolt year class in three areas of New Brunswick, Canada. The year class in this region was the first known to have potential exposure to ISAV beginning at the time of seawater transfer. There was considerable variability in mortality patterns among net pen groups of fish. Net pen outbreak definitions were based on at least seven high mortality days in which there were at least 100 per 100 000 fish per day or >5% cumulative mortality for the study period. There were 106 net pen outbreaks in a study population consisting of 218 net pens. Although the number of new cases decreased as water temperature decreased, overall mortality levels at the study sites did not decrease noticeably. The median peak daily mortality rate during outbreaks was 492 per 100 000 fish per day, with 10% of cases experiencing >5200 mortalities per 100 000 fish per day. The median duration of outbreaks in net pens for which the fish were not slaughtered during the outbreak was 33 days and the median total loss in those outbreaks was 6600 per 100 000 fish. [source] A new role for MSY in single-species and ecosystem approaches to fisheries stock assessment and managementFISH AND FISHERIES, Issue 1 2001In 1977, Peter Larkin published his now-famous paper, ,An epitaph for the concept of maximum sustained yield'. Larkin criticized the concept of single-species maximum sustained yield (MSY) for many reasons, including the possibility that it may not guard against recruitment failure, and the impossibility of maximising sustainable yields for all species simultaneously. However, in recent years, there has been a fundamental change in the perception of the fishing mortality associated with MSY (FMSY) as a limit to be avoided rather than a target that can routinely be exceeded. The concept of FMSY as a limit is embodied in several United Nations Food and Agriculture Organization (FAO) agreements and guidelines, and has now been incorporated into the US Magnuson,Stevens Fishery Conservation and Management Act. As a result, the United States now requires the development of overfishing definitions based on biological reference points that treat the FMSY as a limit reference point and must also define a lower limit on biomass below which rebuilding plans with strict time horizons must be developed. This represents a major paradigm shift from the previously mandated (but often unachieved) objective to simply maintain fishing mortalities at levels below those associated with recruitment overfishing. In many cases, it requires substantial reductions in current fishing mortality levels. Therefore, the necessity of the new paradigm is continually questioned. This paper draws on examples from several fisheries, but specifically focuses on the recent US experience illustrating the practical difficulties of reducing fishing mortality to levels below those corresponding to MSY. However, several studies suggest that even more substantial reductions in fishing mortality may be necessary if ecosystem considerations, such as multispecies interactions, maintenance of biodiversity and genetic diversity, and reduction of bycatch and waste, are taken into account. The pros and cons of moving beyond single-species assessment and management are discussed. A US plan for improving stock assessments indicates that even a ,basic' objective such as ,adequate baseline monitoring of all managed species' may be extremely costly. Thus, the suggestion of Larkin (1983, 1997) that the costs of research and management should not exceed 10,20% of the landed value of the catch may preclude comprehensive ecosystem management. More importantly, neither single-species nor ecosystem-based fisheries management is likely to improve appreciably unless levels of fishing capacity are aligned with resource productivity, as is currently being promoted by FAO and several individual nations. [source] Behaviour of walleye, Sander vitreus, and largemouth bass, Micropterus salmoides, exposed to different wave intensities and boat operating conditions during livewell confinementFISHERIES MANAGEMENT & ECOLOGY, Issue 1 2005C. D. SUSKI Abstract, During live-release angling tournaments in North America, fish are typically retained in livewells onboard boats during the angling day. Mortality of fish occurs at some tournaments, and wave intensities and livewell conditions may influence mortality levels. This study used two species of fish targeted in live-release angling tournaments in North America (largemouth bass Micropterus salmoides L. and walleye Sander vitreus L.) to quantify the response(s) of fish in livewells to different wave treatments. Video analyses revealed that largemouth bass were active during low intensity disturbances, but during violent boat movements tended to settle to the bottom of the livewell and orient to face the direction of the disturbance. Walleye were less active than bass for all treatments, and additionally did not orient to face the direction of disturbance, consequently contacting the side of the livewell during boat rocking. These results are considered in the context of mortality at live-release tournaments. [source] Seasonal and spatial mortality patterns of holm oak seedlings in a reforested soil infected with Phytophthora cinnamomiFOREST PATHOLOGY, Issue 6 2005M. C. Rodríguez-Molina Summary The viability of 1-year-old holm oak (Quercus ilex) seedlings in a soil naturally infected with Phytophthora cinnamomi was studied during 2 consecutive years in a plot located in south-western Spain. In both years, total mortality during autumn and winter was not noticeable (<2.1%). In spring, mortality levels were higher (8.3,4.6%), especially the first year. A steep increase in total mortality occurred in summer, both in the first (11.4%) and second (24.2%) year, but mortality attributable to P. cinnamomi was 1.9 and 7.6%, respectively. Thus, 2 years after planting, total cumulative mortality was 43.4%, and that attributable to P. cinnamomi 9.6% (i.e. 22.1% of total mortality). Fungus-derived mortality followed a spatially aggregated pattern in the reforestation plot, suggesting a clustered distribution of the inoculum in the soil. Furthermore, mortality by P. cinnamomi was also associated with nearness of infected adult trees in the plot. Results obtained are discussed in the framework of seasonal water deficit, P. cinnamomi damage, weed competition and sanitation techniques to be used in declined holm oak stands in Spain. Résumé La viabilité de semis de chênes verts d'un an dans un sol naturellement infecté par P. cinnamomi a été suivie pendant deux années consécutives dans une parcelle du sud-ouest de l'Espagne. La mortalité en automne et hiver a été négligeable (<2.1%) au cours des deux années. La mortalité a été plus forte au printemps (8.3 ,4.6%), particulièrement la première année. Un pic de mortalité a été observé pendant l'été, aussi bien la première (11.4%) que la deuxième année (24.2%) mais la mortalité attribuable àP. cinnamomi n'est que de 1.9% et 7.6% respectivement. Deux ans après plantation, la mortalité cumulée est de 43.4%, dont 9.6% attribuable àP. cinnamomi (22% de la mortalité totale). La mortalité associée à l'agent pathogène présente une agrégation spatiale dans la parcelle reboisée, suggérant une distribution en agrégats de l'inoculum dans le sol. De plus cette mortalité est associée à la proximitéà des arbres infectés dans la parcelle. Les résultats sont discutés dans la perspective du déficit hydrique estival, des dégâts causés par P. cinnamomi, de la compétition herbacée et des techniques sanitaires à utiliser dans les peuplements dépérissants de chênes verts en Espagne. Zusammenfassung Während zwei aufeinander folgenden Jahren wurde die Überlebensrate von einjährigen Steineichen (Quercus ilex)-Sämlingen in einem natürlich mit Phytophthora cinnamomi infizierten Boden auf einer Versuchsfläche in Süd-West-Spanien untersucht. In beiden Jahren war die Mortalität im Herbst und Winter sehr gering (<2.1%). Im Frühling lag die Absterberate besonders im ersten Jahr höher (8,3,4,6%). Im Sommer stieg die Gesamtmortalität stark an, im ersten Jahr betrug sie 11,4%, im zweiten Jahr 24,2%, jedoch lagen die P. cinnamomi zuzuordnenden Raten bei nur 1,9 bzw. 7,6%. Somit lag die Gesamtmortalität zwei Jahre nach der Pflanzung bei 43,4%, die P. cinnamomi zuzuordnende Mortalität bei 9,6% (d.h. 22,1% der abgestorbenen Pflanzen). Die pilzbedingte Mortalität war in der Aufforstungsfläche räumlich aggregiert, was auf eine klumpige Verteilung des Inokulums im Boden schliessen lässt. Zudem war die Mortalität durch P. cinnamomi mit der Nähe zu infizierten adulten Bäumen assoziiert. Diese Ergebnisse werden in Zusammenhang mit jahreszeitlichem Wassermangel, Schäden durch P. cinnamomi, Konkurrenz durch Unkräuter und mögliche phytosanitäre Massnahmen an Standorten mit absterbenden Steineichen diskutiert. [source] Mortality patterns in infectious salmon anaemia virus outbreaks in New Brunswick, CanadaJOURNAL OF FISH DISEASES, Issue 11 2005K L Hammell Abstract Mortality levels attributed to infectious salmon anaemia viral (ISAV) infections were examined at the net pen and site level in the 1996 smolt year class in three areas of New Brunswick, Canada. The year class in this region was the first known to have potential exposure to ISAV beginning at the time of seawater transfer. There was considerable variability in mortality patterns among net pen groups of fish. Net pen outbreak definitions were based on at least seven high mortality days in which there were at least 100 per 100 000 fish per day or >5% cumulative mortality for the study period. There were 106 net pen outbreaks in a study population consisting of 218 net pens. Although the number of new cases decreased as water temperature decreased, overall mortality levels at the study sites did not decrease noticeably. The median peak daily mortality rate during outbreaks was 492 per 100 000 fish per day, with 10% of cases experiencing >5200 mortalities per 100 000 fish per day. The median duration of outbreaks in net pens for which the fish were not slaughtered during the outbreak was 33 days and the median total loss in those outbreaks was 6600 per 100 000 fish. [source] Feeding responses of carabid beetles to dimethoate-contaminated preyAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2004Alice L. Mauchline Abstract 1,The feeding responses of Pterostichus madidus Fab., P. melanarius Illiger and Nebria brevicollis Fab. (Coleoptera: Carabidae) to dimethoate-contaminated prey were investigated in ,no-choice' and ,choice' feeding tests. 2,In the no-choice tests, starved beetles were presented with aphid prey treated with four concentrations of dimethoate. In the choice tests, treated and untreated prey were presented together and the feeding preferences of the starved beetles observed. 3,No avoidance or rejection behaviour was seen in any of the carabids in either of the tests, i.e. no discrimination of the treated and untreated prey was observed. 4,Sufficient dimethoate was consumed with the aphid prey to cause significant mortality levels in the carabids. 5,The concentrations of dimethoate used in these experiments are comparable to field exposure, so carabids feeding in treated fields and field margins could potentially suffer lethal effects via the indirect exposure route of consuming contaminated prey. [source] Rates of caesarean section: analysis of global, regional and national estimatesPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 2 2007Ana P. Betrán Summary Rates of caesarean section are of concern in both developed and developing countries. We set out to estimate the proportion of births by caesarean section (CS) at national, regional and global levels, describe regional and subregional patterns and correlate rates with other reproductive health indicators. We analysed nationally representative data available from surveys or vital registration systems on the proportion of births by CS. We used local non-parametric regression techniques to correlate CS with maternal mortality ratio, infant and neonatal mortality rates, and the proportion of births attended by skilled health personnel. Although very unevenly distributed, 15% of births worldwide occur by CS. Latin America and the Caribbean show the highest rate (29.2%), and Africa shows the lowest (3.5%). In developed countries, the proportion of caesarean births is 21.1% whereas in least developed countries only 2% of deliveries are by CS. The analysis suggests a strong inverse association between CS rates and maternal, infant and neonatal mortality in countries with high mortality levels. There is some suggestion of a direct positive association at lower levels of mortality. CS levels may respond primarily to economic determinants. [source] Beyond Material Explanations: Family Solidarity and Mortality, a Small Area-level AnalysisPOPULATION AND DEVELOPMENT REVIEW, Issue 1 2010Jon Anson Social solidarity, being embedded in a network of binding social relationships, tends to extend human longevity. Yet while average incomes in the Western world, and with them, life expectancies, have risen dramatically, the second demographic transition has occasioned a breakdown in traditional family forms. This article considers whether these trends in family life may have slowed the rise in life expectancy. I present a cross-sectional analysis of Israeli statistical areas (SAs), for which I construct indexes of Standard of Living (SOL), Traditional Family Structure (TFS), and Religiosity (R). I show that (1) increases in all three of these indexes are associated with lower levels of mortality, (2) male mortality is more sensitive to differences in SOL and TFS than is female mortality, and (3) net of differences in SOL and TFS, there is no difference in the mortality levels of Arab and Jewish populations. [source] Political History and Disparities in Safe Motherhood Between Guatemala and HondurasPOPULATION AND DEVELOPMENT REVIEW, Issue 1 2006Jeremy Shiffman Each year, worldwide, more than 500,000 women die of complications from childbirth, making this a leading cause of death globally for adult women of reproductive age. Nearly all studies that have sought to explain the persistence of high maternal mortality levels have focused on the supply of and demand for particular health services. We argue that inquiry on health services is useful but insufficient. Robust explanations for safe motherhood outcomes require examination of factors lying deeper in the causal chain. We compare the cases of Guatemala and Honduras to examine historical and structural influences on maternal mortality. Despite being a poorer country than Guatemala, Honduras has a superior safe motherhood record. We argue that four historical and structural factors stand behind this difference: Honduras's relatively stable and Guatemala's turbulent modern political history; the presence of a marginalized indigenous population in Guatemala, but not in Honduras, that the state has had difficulty reaching; a conservative Catholic Church that has played a larger role in Guatemala than Honduras in blocking priority for reproductive health; and more effective advocacy for maternal mortality reduction in Honduras than Guatemala in the face of this opposition. [source] Urban-Rural Mortality Differentials: An Unresolved DebatePOPULATION AND DEVELOPMENT REVIEW, Issue 1 2003Robert Woods Historians and demographers have long debated the existence, causes, and consequences of historical differences between urban and rural mortality levels. In Europe it has been usual to observe excess mortality in cities compared to the countryside, but in East Asia, by contrast, it has been found that urban areas had relatively favorable mortality environments. The debate continues because a number of pertinent questions remain to be resolved. For example, the way in which mortality is measured may influence the apparent extent of the differential, as may the way in which"urban" and"rural" are defined. Cultural factors need to be taken into account, including the practices of childrearing and the conventions surrounding baptism. Examples drawn from Japan, China, England, and France illustrate the issues involved in comparative analysis, while the urban-rural mortality continuum is examined for nineteenth-century England and Wales using log-normal distributions. [source] The Epidemiologic Transition Revisited: Compositional Models for Causes of Death by Age and SexPOPULATION AND DEVELOPMENT REVIEW, Issue 2 2002Joshua A. Salomon For decades, researchers have noted systematic shifts in cause-of-death patterns as mortality levels change. The notion of the "epidemiologic transition" has influenced thinking about the evolution of health in different societies and the response of the health system to these changes. This article re-examines the epidemiologic transition in terms of empirical regularities in the cause composition of mortality by age and sex since 1950, and considers whether the theory of epidemiologic transition presents a durable framework for understanding more recent patterns. Age-sex-specific mortality rates from three broad cause groups are analyzed: Group 1 (communicable diseases, maternal and perinatal causes, and nutritional deficiencies); Group 2 (noncommunicable diseases); and Group 3 (injuries), using the most extensive international database on mortality by cause, including 1,576 country-years of observation, and new statistical models for compositional data. The analyses relate changes in cause-of-death patterns to changing levels of all-cause mortality and income per capita. The results confirm that declines in overall mortality are accompanied by systematic changes in the composition of causes in many age groups. These changes are most pronounced among children, for whom Group 1 causes decline as overall mortality falls, and in younger adults, where strikingly different patterns are found for men (shift from Group 3 to Group 2) compared to women (shift toward Group 2 then Group 3). The underlying patterns that emerge from this analysis offer insights into the epidemiologic transition from high-mortality to low-mortality settings. [source] Implications of recreational fishing for elasmobranch conservation in the Great Barrier Reef Marine ParkAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 3 2010Ann-Maree J. Lynch Abstract 1.309 Great Barrier Reef Marine Park recreational fishers were surveyed to examine recreational catch and harvest of elasmobranchs and to explore recreational fishers' handling behaviour and attitudes. 2.Elasmobranchs represented 6% of fishers' total catch of all fish (including released individuals), and 0.8% of fishers' total harvest (i.e. retained individuals) across all survey days. The majority of elasmobranchs caught by fishers were released, primarily because they were perceived as being inedible. 3.Recreational fishers' self-reported handling and release behaviour for elasmobranchs is largely consistent with ,best practice' guidelines except that fishers had low use of circle hooks and barbless hooks, and a significant proportion (33%) reported using stainless steel hooks. 4.Most fishers had positive attitudes towards elasmobranchs, placing high importance on releasing sharks and rays in good condition (86%), high value on their existence (84%), and low value on catching them (63%). 5.Results indicate that post-release mortality is probably the largest source of recreational fishing mortality of elasmobranchs in the Great Barrier Reef. Future research should be targeted at obtaining better estimates of species-specific post-release mortality levels, understanding how post-release survival can be increased by changing fishing techniques or fisher behaviour, and developing more effective methods of engaging fishers in elasmobranch conservation. Copyright © 2009 John Wiley & Sons, Ltd. [source] Maternal Mortality, United States and Canada, 1982,1997BIRTH, Issue 1 2000Donna L. Hoyert PhD Background:The 1998 public awareness campaign on Safe Motherhood called attention to the issue of maternal mortality worldwide. This paper focuses upon maternal mortality trends in the United States and Canada, and examines differentials in maternal mortality in the United States by maternal characteristics. Methods:Data from the vital statistics systems of the United States and Canada were used in the analysis. Both systems identify maternal deaths using the definition of the World Health Organization's International Classification of Diseases. Numbers of deaths, maternal mortality rates, and confidence intervals for the rates are shown in the paper. Results:Maternal mortality declined for much of the century in both countries, but the rates have not changed substantially between 1982 and 1997. In this period the maternal mortality levels were lower in Canada than in the United States. Maternal mortality rates vary by maternal characteristics, especially maternal age and race. Conclusions:Maternal mortality continues to be an issue in developed countries, such as the United States and Canada. Maternal mortality rates have been stable recently, despite evidence that many maternal deaths continue to be preventable. Additional investment is needed to realize further improvements in maternal mortality. [source] | ||||||||||||||||