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Mortality Patterns (mortality + pattern)
Selected AbstractsMortality 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] Mortality patterns among workers exposed to arsenic, cadmium, and other substances in a copper smelterAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2009Gary M. Marsh PhD Abstract Objective To evaluate the long-term mortality experience of workers exposed to arsenic, cadmium, and other substances at a copper mine and smelter in Copperhill, Tennessee studied earlier as part of an industry-wide study. Methods Subjects were 2,422 male workers employed three or more years in the smelter or mill between 1/1/46 until the plant strike and scale-down of operations in April 1996. Vital status was determined through 2000 for 99.4% of subjects and cause of death for 91.3% of 878 deaths. Historical exposures were estimated for lead, SO2, arsenic, cadmium, dust, and cobalt. We computed standardized mortality ratios (SMRs) based on U.S. and local county rates and modeled internal relative risks (RRs). Results We observed overall deficits in deaths based on national and local county comparisons from all causes, all cancers and most of the cause of death categories examined. We found limited evidence of increasing mortality risks from cerebrovascular disease with increasing duration and cumulative arsenic exposure, but no evidence of an exposure,response relationship for cadmium exposure and bronchitis. Conclusions Our limited evidence of an association between inhaled arsenic exposure and CVD is an exploratory finding not observed in other epidemiology studies of more highly exposed occupational populations. Possible alternative explanations include chance alone and uncontrolled confounding or effect modification by co-exposures or other factors correlated with arsenic exposure and unique to the Copperhill facility. Am. J. Ind. Med. 52:633,644, 2009. © 2009 Wiley-Liss, Inc. [source] Causes of death among HIV-infected patients in the era of highly active antiretroviral therapy, Bordeaux, France, 1998,1999HIV MEDICINE, Issue 3 2002F Bonnet Objectives To describe the causes of death in HIV-infected patients in the era of highly active antiretroviral therapy (HAART). Method A retrospective survey conducted in Bordeaux, France. Medical records of all deaths that had occurred in 1998 and 1999 amongst patients followed within the Aquitaine cohort were reviewed by the same physician. Immediate and underlying causes of death were described, taking into account the morbidity at the time of death. Results Sixty-six deaths occurred in 1998, and 41 in 1999. Sixty-seven per cent of deceased patients were male. Median age at time of death was 43 years (range 25,71), median CD4 was 162 cells/µL (0,957); 28% of patients had a CD4 count > 200 cells/µL and 7% plasma viral load < 500 HIV-RNA copies/mL. Amongst morbidity present at the time of death, there were 23 bacterial infections, 16 non-Hodgkin's lymphomas, 16 cirrhoses, 15 non HIV-related malignancies, 13 central nervous system diseases and 10 myocardiopathies. The main immediate causes of death were: multiple organ failure (21%), coma (18%), septic shock (15%) and acute respiratory failure (14%). Underlying causes of death were AIDS-defining events (48%), non AIDS HIV-related infection (3%), hepatitis B- or C-associated cirrhosis (14%), non HIV-related malignancies (11%), cardiovascular events (10%), suicide and overdose (6%), treatment-related fatalities (4%), injury (2%) and unknown (2%). Patients dying from AIDS-related events were more often female, had a lower CD4 count, a higher level of HIV-RNA, a shorter history of HIV infection and were less often coinfected with hepatitis B and C viruses than those dying from other underlying causes. Conclusions AIDS-related events are no longer the major causes of death of HIV-infected patients in the era of HAART. This evolving mortality pattern justifies an adaptation of both the epidemiological surveillance and the clinical monitoring of HIV-infected patients. [source] Evaluation of predictors of mortality in Frontotemporal Dementia,methodological aspectsINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 7 2003A. Gräsbeck Abstract Objectives To retrospectively evaluate pre-diagnostic clinical features (predictors) of mortality in frontotemporal dementia (FTD). The main aim was to investigate if there were indications against interpreting missing data as signs of absence. Material and methods 96 cases with FTD, here defined as Dementia in Pick's disease according to ICD-10. The predictors were behavioural/psychiatric features, language impairment and neurological deficits up to the date of diagnosis. Each predictor was rated as present (Yes), absent (No) or not recorded (Missing), and evaluated according to its distribution and mortality pattern: if a feature was not recorded because it was absent, the mortality of the Missing and the No-category should hypothetically be close. Statistical methods included Kaplan-Meier survival curves and Cox regression analyses. Results Neurological deficits and language impairments were frequently recorded as present or absent, while non-recordings were more prevalent among the behavioural/psychiatric features. Some features were excluded as predictors because they showed too little variation. Analyses of the survival pattern indicated that in some features, the observations of the Missing-category could be interpreted as absence of the symptoms. In other features these observations had to be regarded as truly missing. Conclusions In the retrospective evaluation of predictors of mortality a method for treating missing data was applied. The interpretation of non-recordings as signs of absence was supported by the analyses of the survival patterns in some of the studied features. However, the study underscores the importance of systematic estimations of pre-diagnostic clinical features in dementia. Copyright © 2003 John Wiley & Sons, Ltd. [source] Dynamics of black spot sea bream (Pagellus bogaraveo) mean length: evaluating the influence of life history parameters, recruitment, size selectivity and exploitation ratesJOURNAL OF APPLIED ICHTHYOLOGY, Issue 3 2006K. Erzini Summary Stochastic simulations were used to evaluate the influence of recruitment pattern (log-normal, decreasing), size selectivity (normal, logistic model) and fishing mortality pattern (abrupt, continuous increase in fishing mortality) on the evolution of mean length and the dispersion of mean length for a relatively long-lived deep-water species, the black spot sea bream (Pagellus bogaraveo). An abrupt increase in fishing mortality resulted in mean size decreasing and stabilizing at a lower level while a steady increase in fishing mortality caused the continuous decrease in mean size that has been reported for many long-lived species. Decrease in mean size was greatest for logistic model simulations and for cases where fish were susceptible to capture at a small size. Logistic selectivity, with decreasing recruitment and increasing fishing mortality over time, resulted in mean length and variability in mean length trends similar to that observed for the Strait of Gibraltar fishery. Furthermore, it was found with the declining recruitment that moderate increases in fishing mortality can result in significant decreases in mean length. Given the importance of mean size as an indicator of the state of a resource, these simulations are a useful alternative or complement to standard fisheries assessment methods, helping to provide information on exploitation patterns and rates that can be used for conservation and management. [source] Experimental susceptibility of different life-stages of the giant freshwater prawn, Macrobrachium rosenbergii (de Man), to white spot syndrome virus (WSSV)JOURNAL OF FISH DISEASES, Issue 4 2002R B Pramod Kiran Studies were conducted by injecting/feeding white spot syndrome virus (WSSV) derived from infected shrimp, Penaeus monodon (Fabricius), to different life-stages, namely post-larvae, juveniles, sub-adults and adults of Macrobrachium rosenbergii (de Man). The disease was also induced in brood stock, and the eggs and larvae derived from these animals were subsequently tested for WSSV infection. All the stages except egg used for the experiment were found WSSV positive in histopathology, cross infection bioassay and polymerase chain reaction (PCR) analysis. Experimentally infected post-larvae and juveniles showed a high percentage of mortality and an increased rate of cannibalism. The cumulative mortality in post-larvae was up to 28%; with 28,40% cannibalism resulting in a maximum loss of up to 68%. In juveniles, observed mortality and cannibalism were 10,20% and 6.7,30.0%, respectively, and the maximum loss recorded was 50%. In sub-adults, mortality ranged from 2.8 to 6.7%, cannibalism was up to 20% and the total loss was up to 26.7%. Sub-adults and adults were found to be more tolerant to the infection as evidenced by the mortality pattern. A nested (two-step) PCR resulted in a 570-bp product specific to WSSV in all stages, except the eggs. [source] Mortality among Ontario members of the International Union of Bricklayers and Allied CraftworkersAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2005Murray M. Finkelstein PhD Abstract Background Dust exposed workers may be at increased risk of pneumoconiosis, stomach cancer, lung cancer, and obstructive lung disease. Bricklayers may experience high exposures to silica and inorganic dusts. The aim of this study was to examine the mortality pattern of bricklayers to identify occupational associations with mortality. Methods A cohort of 10,953 workers was assembled from records of the International Union of Bricklayers and Allied Craftworkers (IUBAC). Mortality was ascertained by linkage to the Canadian Mortality Registry at Statistics Canada. Standardized Mortality Ratios (SMRs) were computed using Ontario general population mortality rates as the reference. Results Twenty or more years from first membership, SMRs for lung (158; 130,190) and stomach (235; 140,370) cancers were significantly elevated. There were four deaths from pneumoconiosis, but non-malignant respiratory mortality SMRs were not increased. Conclusions Bricklayers and Allied Craftworkers are at risk from diseases associated with heavy exposure to inorganic dust: lung cancer, stomach cancer, and pneumoconiosis. Dust control as well as education and training of these workers to protect themselves against inhalation hazards is necessary. Am. J. Ind. Med. 47:4,9, 2005. © 2004 Wiley-Liss, Inc. [source] Mortality in a cohort of Danish patients with fibromyalgia: Increased frequency of suicideARTHRITIS & RHEUMATISM, Issue 10 2010Lene Dreyer Objective A previous study demonstrated an association between self-reported widespread body pain and increased mortality. The aim of this study was to analyze whether fibromyalgia (FM) and FM-like symptoms are related to increased mortality. Methods From hospital records, we identified 1,361 patients referred during the period 1984,1999 because of the suspicion of FM. The cases were reviewed by reviewers who were blinded to the outcome. The cohort was followed up for a total of 5,295 person-years at risk and was linked to the Danish Mortality Register. Using the number of years at risk and sex-, age-, and calendar-specific mortality rates from the general population, cause-specific standardized mortality ratios [SMRs] were calculated. Results We observed no overall increased mortality among patients with FM. Among the 1,269 female patients, the SMRs (95% confidence intervals [95% CIs]) for an increased risk of death from suicide, liver cirrhosis/biliary tract disease, and cerebrovascular disease were 10.5 (95% CI 4.5,20.7), 6.4 (95% CI 2.3,13.9), and 3.1 (95% CI 1.1,6.8), respectively. The suicide risk was increased at the time of diagnosis and remained increased after 5 years. Patients meeting the American College of Rheumatology criteria for FM and patients with possible FM had the same cause-specific mortality pattern. No increased cause-specific mortality was observed in the 84 male patients. Conclusion The causes of a markedly increased rate of suicide among female patients with FM are at present unknown but may be related to increased rates of lifetime depression, anxiety, and psychiatric disorders. Risk factors for suicide should be sought at the time of the diagnosis of FM and at followup. The results also suggest that risk factors for liver disease and cerebrovascular disease should be evaluated in patients with FM. [source] Could accelerated aging explain the excess mortality in patients with seropositive rheumatoid arthritis?ARTHRITIS & RHEUMATISM, Issue 2 2010Cynthia S. Crowson Objective To determine whether the mortality pattern in patients with seropositive rheumatoid arthritis (RA) is consistent with the concept of accelerated aging, by comparing the observed mortality rates in patients with RA with the age-accelerated mortality rates from the general population. Methods A population-based inception cohort of patients with seropositive RA (according to the American College of Rheumatology 1987 criteria) was assembled and followed up for vital status until July 1, 2008. The expected mortality rate was obtained by applying the death rates from the general population to the age, sex, and calendar year distribution of the RA population. The observed mortality was estimated using Kaplan-Meier methods. Acceleration factors for the expected mortality were estimated in accelerated failure time models. Results A total of 755 patients with seropositive RA (mean age 55.6 years, 69% women) were followed up for a mean of 12.5 years, during which 315 patients died. The expected median survival was age 82.4 years, whereas the median survival of the RA patients was age 76.7 years. Results of statistical modeling suggested that, in terms of mortality rates, patients with RA were effectively 2 years older than actual age at RA incidence, and thereafter the patients underwent 11.4 effective years of aging for each 10 years of calendar time. Conclusion The overall observed mortality experience of patients with seropositive RA is consistent with the hypothesis of accelerated aging. The causes of accelerated aging in RA deserve further investigation. [source] Noninvasive Stress and Reproductive Measures of Social and Ecological Pressures in Free-Ranging African ElephantsCONSERVATION BIOLOGY, Issue 4 2001C. A. H. Foley This, coupled with political pressures to delist the elephant, has created a need for noninvasive physiological measures that can quantify the long-term effects of past mortality patterns of this long-lived species. We collected fresh fecal samples from 16 female elephants in three different groups over 23 months at Tarangire National Park, Tanzania, and analyzed them for fecal progesterone and cortisol metabolites. Social and ecological measures were collected concurrently. Fecal progesterone metabolite measures corresponded significantly with stage of gestation, and appear to be able to confirm pregnancy in female elephants from as early as 3 months of gestation. We found that progesterone metabolite concentrations were significantly lower during the dry season than during the wet season after controlling for stage of gestation. Fecal cortisol metabolite concentrations showed the opposite seasonal pattern, being significantly higher in the dry season and inversely correlated with rainfall across seasons. Fecal cortisol metabolite concentrations also increased with group size and were correlated positively with dominance rank in the largest group. Our results suggest that measures of progesterone and cortisol metabolites in feces provide indices of reproductive function and physiological stress that can quantify both natural and human disturbances in African elephants. These measures are ideally suited for monitoring the long-term effects of social disruption from poaching and a variety of other management concerns. Resumen: Debido a la cacería furtiva, la población de elefante africano ( Loxodonta africana) declinó en un 60%, principalmente adultos, entre 1979 y 1988. Esto, aunado a presiones políticas para eliminar al elefante de las listas de especies en peligro, ha creado la necesidad de medidas fisiológicas no invasivas que puedan cuantificar efectos a largo plazo de patrones de mortalidad en el pasado de esta especie longeva. Recolectamos muestras fecales de 16 elefantes hembras en tres grupos diferentes en el Parque Nacional Tarangire, Tanzania a lo largo de 23 meses, y las analizamos para detectar metabolitos de progesterona fecal y de cortisol. Al mismo tiempo se recolectaron medidas sociales y ecológicas. Las medidas de metabolitos de progesterona fecal correspondieron significativamente con la etapa de gestación, y parecen permitir la confirmación de preñez en elefantes hembras tan temprano como a los tres meses de gestación. Las concentraciones de metabolitos de progesterona fueron significativamente menores durante la época de sequía que en la de lluvias después de controlar para la etapa de gestación. Las concentraciones de metabolitos de cortisol fecal mostraron un patrón estacional opuesto, siendo significativamente más altas en la época de sequía e inversamente correlacionados con la precipitación en todas las estaciones. Las concentraciones de metabolitos de cortisol fecal también incrementaron con el tamaño del grupo y se correlacionaron positivamente con el rango de dominancia en el grupo más grande. Nuestros resultados sugieren que las medidas de metabolitos de progesterona y cortisol en las heces proporcionan índices de la función reproductiva y del estrés fisiológico que puede cuantificar perturbaciones, tanto naturales como humanas, en elefantes africanos. Estas medidas son idealmente adecuadas para monitorear efectos a largo plazo de la disrupción social por la cacería furtiva y así como una variedad de aspectos del manejo. [source] Temperature and hen harrier productivity: from local mechanisms to geographical patternsECOGRAPHY, Issue 5 2002S. M. Redpath Climate is an important factor limiting demography and distribution patterns in many organisms. For species with a broad geographical distribution, the mechanism by which climate influences demography is likely to vary dramatically from one end of the range to the other. In this paper we first assess, in a Scottish population of hen harriers Circus cyaneus, how temperature and rainfall influence adult behaviour and chick mortality patterns at the nest. We then test for associations between harrier productivity and weather across Scotland, towards the northern edge of the range, and Spain, towards the southern edge of the range. We show that during the nestling period, female brooding time increased in cold weather. Male provisioning rate was negatively related to temperature and rainfall. Chick mortality increased in cold temperatures and was most likely to occur at nests where male prey delivery rates were low relative to temperature. Annual values of harrier fledged brood size across Scotland were positively related to summer temperature suggesting that the patterns seen in one population held at a national scale. In Spain, however, the opposite patterns were observed with fledged brood size being negatively related to temperature. This shows that whilst the impact of weather on productivity may be equally strong at two ends of a geographical range, the mechanisms vary dramatically. Large-scale predictive models need to take such patterns into account. [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] Uncertainties in interpretation of isotope signals for estimation of fine root longevity: theoretical considerationsGLOBAL CHANGE BIOLOGY, Issue 7 2003YIQI LUOArticle first published online: 25 JUN 200 Abstract This paper examines uncertainties in the interpretation of isotope signals when estimating fine root longevity, particularly in forests. The isotope signals are depleted ,13C values from elevated CO2 experiments and enriched ,14C values from bomb 14C in atmospheric CO2. For the CO2 experiments, I explored the effects of six root mortality patterns (on,off, proportional, constant, normal, left skew, and right skew distributions), five levels of nonstructural carbohydrate (NSC) reserves, and increased root growth on root ,13C values after CO2 fumigation. My analysis indicates that fitting a linear equation to ,13C data provides unbiased estimates of longevity only if root mortality follows an on,off model, without dilution of isotope signals by pretreatment NSC reserves, and under a steady state between growth and death. If root mortality follows the other patterns, the linear extrapolation considerably overestimates root longevity. In contrast, fitting an exponential equation to ,13C data underestimates longevity with all the mortality patterns except the proportional one. With either linear or exponential extrapolation, dilution of isotope signals by pretreatment NSC reserves could result in overestimation of root longevity by several-fold. Root longevity is underestimated if elevated CO2 stimulates fine root growth. For the bomb 14C approach, I examined the effects of four mortality patterns (on,off, proportional, constant, and normal distribution) on root ,14C values. For a given ,14C value, the proportional pattern usually provides a shorter estimate of root longevity than the other patterns. Overall, we have to improve our understanding of root growth and mortality patterns and to measure NSC reserves in order to reduce uncertainties in estimated fine root longevity from isotope data. [source] Size-dependent predation risk in tree-feeding insects with different colouration strategies: a field experimentJOURNAL OF ANIMAL ECOLOGY, Issue 5 2009Triinu Remmel Summary 1. Body size is positively correlated with fecundity in various animals, but the factors that counterbalance the resulting selection pressure towards large size are difficult to establish. Positively size-dependent predation risk has been proposed as a selective factor potentially capable of balancing the fecundity advantage of large size. 2. To construct optimality models of insect body size, realistic estimates of size-dependent predation rates are necessary. Moreover, prey traits such as colouration should be considered, as they may substantially alter the relationship between body size and mortality risk. 3. To quantify mortality patterns, we conducted field experiments in which we exposed cryptic and conspicuous artificial larvae of different sizes to bird predators, and recorded the incidence of bird attacks. 4. The average daily mortality rate was estimated to vary between 4% and 10%. In both cryptic and conspicuous larvae, predation risk increased with prey size, but the increase tended to be steeper in the conspicuous group. No main effect of colour type was found. All the quantitative relationships were reasonably consistent across replicates. 5. Our results suggest that the size dependence of mortality risk in insect prey is primarily determined by the probability of being detected by a predator rather than by a size-dependent warning effect associated with conspicuous colouration. Our results therefore imply that warningly coloured insects do not necessarily benefit more than the cryptic species from large body size, as has been previously suggested. [source] Sex-biased juvenile survival in a bird with extreme size dimorphism, the great bustard Otis tardaJOURNAL OF AVIAN BIOLOGY, Issue 3 2007Carlos A. Martín We explored sex-biased mortality patterns in a species showing the most extreme sexual dimorphism among birds, the great bustard Otis tarda. Between 1991 and 2005 we studied juvenile and immature survival in a sample of 361 great bustards radio-tagged at two different populations in Spain, Villafáfila and Madrid. Mortality decreased with age, from high rates during the first year (0.70), to 0.10 in the second year. Using the known-fate model in program MARK we found that monthly survival increased throughout the first year. Offspring showing higher body mass at marking, i.e. those hatched earlier in the season and those with better body condition, survived in higher proportion. This was probably related to the earlier breeding dates of more experienced mothers, as well as to the observed decrease in food availability as the season progresses. Monthly survival estimates were higher in females than in males, which suggests that juvenile males are more vulnerable to reduced food availability and other factors due to their much faster growth rates. The proportion of non-natural deaths increased with age, and was higher in the Madrid population, where illegal hunting and collision with powerlines showed a high incidence. The male-biased mortality found in young birds in this study explains the female-biased population sex ratios observed in great bustard populations. The different degrees of incidence of human-induced causes of mortality found between both populations studied suggest that such differences may contribute to the variation observed in the adult sex ratio among populations. [source] Plasticity of death rates in stationary phase in Saccharomyces cerevisiaeAGING CELL, Issue 1 2009Nadège Minois Summary For the species that have been most carefully studied, mortality rises with age and then plateaus or declines at advanced ages, except for yeast. Remarkably, mortality for yeast can rise, fall and rise again. In the present study we investigated (i) if this complicated shape could be modulated by environmental conditions by measuring mortality with different food media and temperature; (ii) if it is triggered by biological heterogeneity by measuring mortality in stationary phase in populations fractionated into subpopulations of young, virgin cells, and replicatively older, non-virgin cells. We also discussed the results of a staining method to measure viability instead of measuring the number of cells able to exit stationary phase and form a colony. We showed that different shapes of age-specific death rates were observed and that their appearance depended on the environmental conditions. Furthermore, biological heterogeneity explained the shapes of mortality with homogeneous populations of young, virgin cells exhibiting a simple shape of mortality in conditions under which more heterogeneous populations of older cells or unfractionated populations displayed complicated death rates. Finally, the staining method suggested that cells lost the capacity to exit stationary phase and to divide long before they died in stationary phase. These results explain a phenomenon that was puzzling because it appeared to reflect a radical departure from mortality patterns observed for other species. [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] Risk factors associated with mortalities attributed to infectious salmon anaemia virus in New Brunswick, CanadaJOURNAL OF FISH DISEASES, Issue 11 2005K L Hammell Abstract Outbreaks of unexplained mortalities attributed to infectious salmon anaemia (ISA) were examined in the 1996 year class of Atlantic salmon in three regions of New Brunswick, Canada. A total of 218 net pens at 14 sites deemed to have been exposed to ISA virus (ISAV) were surveyed for mortality records and management, environmental and host characteristics. Based on definitions of mortality patterns, clinical ISA disease outbreaks occurred in 106 net pens. There were eight sites in which >50% of net pens experienced ISA outbreaks during the study period. Factors related to their potential role in transmission of virus to new sites or new net pens at the same site were identified as sea lice vectors, divers visiting multiple sites, sites belonging to companies with more than one site, exposure to other year classes at the site, and proximity to other infected net pens. Host resistance factors associated with greater risk of outbreaks were identified as larger groupings, general health following smolt transfer, stressful husbandry procedures during growout, and health or productivity during colder water periods. Despite very close proximity between sites, modification of these management factors would probably influence the severity of mortalities caused by ISAV. [source] Age Estimation by Pulp/Tooth Ratio in Canines by Peri-Apical X-RaysJOURNAL OF FORENSIC SCIENCES, Issue 1 2007Roberto Cameriere Ph.D. ABSTRACT: Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x1) and lower (x2) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x1 and x2 and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years. [source] Detecting year-of-birth mortality patterns with limited dataJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2008S. J. Richards Summary., Late life mortality patterns are of crucial interest to actuaries assessing risk of longevity, most obviously for annuities and defined benefit pension schemes. The stability of public finances is also affected, as the governments have very substantial risk of longevity in the form of state benefits and public sector pension schemes. One important explanatory variable for late life mortality patterns is year of birth. Previous work has demonstrated various techniques for detecting such patterns, but always with long time series of mortality rates. The paper describes two alternative ways to detect such patterns, even with missing population data or the absence of a time series. The paper finds support for the idea that different birth cohorts have different rates of aging. [source] Memory, Forgetting, and Economic Crisis:MEDICAL ANTHROPOLOGY QUARTERLY, Issue 1 2010Drug Use, Social Fragmentation in an Argentine Shantytown Closely linked to the increase in psychotropic pill consumption, forgetting and remembering emerged from devastated social scenarios as a new local idiom among poor youth in the late 1990s and the new millennium. Drawing on ethnographic fieldwork carried out during the years of the deepest economic crisis in Argentina (2001,03), I argue that psychotropic pill consumption is associated with not only deteriorating economic conditions but also changes in the quality and price of cocaine, and in the scarcity and subsequent change of status of medications during the economic breakdown. Taking into account developments in the field of memory studies, I examine the relationship among political economy, social memory work, and changing drug-use practices. Regarding memory as a social practice, I argue that the growth of psychotropic pill consumption in the late 1990s can be understood through the interplay of Paul Ricoeur's notions regarding different kinds and levels of forgetting. By analyzing changing survival strategies, social network dismantlement, changing mortality patterns, and abusive police repression, I discuss how social fragmentation engendered by structural reforms has modified social memory work. [source] Multiple predator effects on size-dependent behavior and mortality of two species of anuran larvaeOIKOS, Issue 2 2000Peter Eklöv This study examined the effects of multiple predators on size-specific behavior and mortality of two species of anuran larvae. Particularly, we focused on how trait changes in predators and prey may be transmitted to other species in the food web. In laboratory experiments, we examined the effects of bluegill sunfish, Lepomis macrochirus, and the odonate larva Anax junius on behavior and mortality of tadpoles of the bullfrog, Rana catesbeiana, and the green frog R. clamitans. Experiments were conducted with predators alone and together to assess effects on behavior and mortality of the tadpoles. The experiments were replicated on five size classes of the tadpoles to evaluate how responses varied with body size. Predation rates by Anax were higher on bullfrogs than on green frogs, and both bullfrogs and green frogs suffered greater mortality from Anax than from bluegill. Bluegill only consumed green frogs. Predation rates by both predators decreased with increasing tadpole size and decreased in the non-lethal (caged) presence of the other predator. Both anuran larvae decreased activity when exposed to predators. Bullfrogs, however, decreased activity more in the presence of Anax than in the presence of bluegill, whereas green frogs decreased activity similarly in the presence of both predators. The largest size class of green frogs, but not of bullfrogs, exhibited spatial avoidance of bluegill. These responses were directly related to the risk posed by the different predators to each anuran species. Anax activity (speed and move frequency) also was higher when alone than in the non-lethal presence of bluegill. We observed decreased predation rate of each predator in the non-lethal presence of the other, apparently caused by two different mechanisms. Bluegill decreased Anax mortality on tadpoles by restricting the Anax activity. In contrast, Anax decreased bluegill mortality on tadpoles by reducing tadpole activity. We discuss how the activity and spatial responses of the tadpoles interact with palatability and body size to create different mortality patterns in the prey species and the implications of these results to direct and indirect interactions in this system. [source] Mortality among sheet metal workers participating in a medical screening programAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2009John Dement PhD Abstract Background The Sheet Metal Occupational Health Institute Trust (SMOHIT) was formed in 1985 to examine the health hazards of the sheet metal industry in the U.S. and Canada through an asbestos disease screening program. A study of mortality patterns among screening program participants was undertaken. Methods A cohort of 17,345 individuals with 20 or more years in the trade and who participated in the asbestos disease screening program were followed for vital status and causes of death between 1986 and 2004. Data from the screening program included chest X-ray results by International Labour Office (ILO) criteria and smoking history. Standardized mortality ratios (SMRs) by cause were generated using U.S. death rates and Cox proportional hazards models were used to investigate lung cancer risk relative to chest X-ray changes while controlling for smoking. Results A significantly reduced SMR of 0.83 (95% CI,=,0.80,0.85) was observed for all causes combined. Statistically significant excess mortality was observed for pleural cancers, mesothelioma, and asbestosis in the SMR analyses. Both lung cancer and COPD SMRs increased consistently and strongly with increasing ILO profusion score. In Cox models, which controlled for smoking, increased lung cancer risk was observed among workers with ILO scores of 0/1 (RR,=,1.17, 95% CI,=,0.89,1.54), with a strong trend for increasing lung cancer risk with increasing ILO profusion score >0/0. Conclusions Sheet metal workers are at increased risk for asbestos-related diseases. This study contributes to the literature demonstrating asbestos-related diseases among workers with largely indirect exposures and supports an increased lung cancer risk among workers with low ILO profusion scores. Am. J. Ind. Med. 52:603,613, 2009. © 2009 Wiley-Liss, Inc. [source] The effect of sex on risk of mortality during the Black Death in London, A.D. 1349,1350AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Sharon N. DeWitte Abstract The Black Death of 1347,1351 was one of the most devastating epidemics in human history, and though it is frequently assumed that the epidemic killed indiscriminately, recent research suggests that the disease was selective, at least with respect to frailty. The purpose of this study is to determine whether the Black Death was similarly selective with respect to biological sex,that is, did either sex face an elevated risk during the epidemic or were men and women at equal risk of dying? A sample of 298 victims of the Black Death, from the East Smithfield cemetery in London, is compared to a pre-Black Death normal mortality sample of 194 individuals from two Danish urban cemeteries, St Mikkel Church (Viborg) and St Albani Church (Odense). To assess the effect of sex on risk of death, sex is modeled as a covariate affecting the Gompertz,Makeham model of adult mortality. The results suggest that sex did not strongly affect risk of death in either the normal mortality or Black Death samples. These results are important for improving our understanding of Black Death mortality patterns. This is essential for understanding the effects the Black Death had on European populations, and the methods used here can potentially be informatively applied to investigations of other episodes of epidemic diseases in past populations. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Reconstruction of paleodemographic characteristics from skeletal age at death distributions: Perspectives from Hitotsubashi, JapanAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2007Tomohito Nagaoka Abstract This is a demographic exploration of the city of Edo, which reveals the changes that accompanied its urbanization and analyzes the skeletal remains of 207 individuals from a specific site in Tokyo (Hitotsubashi), using several paleodemographic approaches. A comparison of the three methods employed herein suggests that the Bayesian and maximum likelihood estimation techniques provide more plausible mortality patterns than the direct method of age estimation because the direct method of age estimation relies on published age intervals for the auricular surface and that would account for the underestimation of old people relative to the other two methods. Analyses using these new approaches indicate a short life span tendency for the people of Hitotsubashi. Although we cannot rule out methodological problems of adult-age estimation, one plausible interpretation of that life expectancy is an inadequate food supply and a poor public health situation. This study suggests that, in Tokugawa Japan, urbanization might have imposed health risks, increasing the risk of mortality. Analysis of demographic data from Hitotsubashi has refined our understanding on the impact of urbanization on the Edo period, and presents new perspectives on paleodemography in Japan. Am J Phys Anthropol 2007. © 2007 Wiley-Liss, Inc. [source] Physical maturation, life-history classes and age estimates of free-ranging western gorillas,insights from Mbeli Bai, Republic of CongoAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009Thomas Breuer Abstract Physical maturation and life-history parameters are seen as evolutionary adaptations to different ecological and social conditions. Comparison of life-history patterns of closely related species living in diverse environments helps to evaluate the validity of these assumptions but empirical data are lacking. The two gorilla species exhibit substantial differences in their environment, which allows investigation into the role of increased frugivory in shaping western gorilla life histories. We present behavioral and morphological data on western gorilla physical maturation and life-history parameters from a 12.5-year study at Mbeli Bai, a forest clearing in the Nouabalé-Ndoki National Park in northern Congo. We assign photographs of known individuals to different life-history classes and propose new age boundaries for life-history classes in western gorillas, which can be used and tested at other western gorilla research sites. Our results show that western gorillas are weaned at a later age compared with mountain gorillas and indicate slower physical maturation of immatures. These findings support the risk-aversion hypothesis for more frugivorous species. However, our methods need to be applied and tested with other gorilla populations. The slow life histories of western gorillas could have major consequences for social structure, mortality patterns and population growth rates that will affect recovery from population crashes of this critically endangered species. We emphasize that long-term studies can provide crucial demographic and life-history data that improve our understanding of life-history evolution and adaptation and help to refine conservation strategies. Am. J. Primatol. 71:106,119, 2009. © 2008 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||