Risky behavior and its effect on survival: snowshoe hare behavior under varying moonlight conditions

USGS Publications Warehouse

Gigliotti, Laura C.; Diefenbach, Duane R.

2018-01-01

Predation and predation risk can exert strong influences on the behavior of prey species. However, risk avoidance behaviors may vary among populations of the same species. We studied a population of snowshoe hares (Lepus americanus) near the southern edge of their range, in Pennsylvania. This population occupies different habitat types, experiences different environmental conditions, and are exposed to different predator species and densities than northern hare populations; therefore, they might exhibit differences in risk avoidance behaviors. We analyzed hare survival, movement rates, and habitat use under different levels of predation risk, as indexed by moonlight. Similar to previous work, we found snowshoe hare survival decreased with increased moon illumination during the winter, but we found differences in behavioral responses to increased predation risk. We found that snowshoe hares did not reduce movement rates during high‐risk nights, but instead found that hares selected areas with denser canopy cover, compared to low‐risk nights. We suggest that behavioral plasticity in response to predation risk allows populations of the same species to respond to localized conditions.

Women live longer than men even during severe famines and epidemics.

PubMed

Zarulli, Virginia; Barthold Jones, Julia A; Oksuzyan, Anna; Lindahl-Jacobsen, Rune; Christensen, Kaare; Vaupel, James W

2018-01-23

Women in almost all modern populations live longer than men. Research to date provides evidence for both biological and social factors influencing this gender gap. Conditions when both men and women experience extremely high levels of mortality risk are unexplored sources of information. We investigate the survival of both sexes in seven populations under extreme conditions from famines, epidemics, and slavery. Women survived better than men: In all populations, they had lower mortality across almost all ages, and, with the exception of one slave population, they lived longer on average than men. Gender differences in infant mortality contributed the most to the gender gap in life expectancy, indicating that newborn girls were able to survive extreme mortality hazards better than newborn boys. Our results confirm the ubiquity of a female survival advantage even when mortality is extraordinarily high. The hypothesis that the survival advantage of women has fundamental biological underpinnings is supported by the fact that under very harsh conditions females survive better than males even at infant ages when behavioral and social differences may be minimal or favor males. Our findings also indicate that the female advantage differs across environments and is modulated by social factors. Copyright © 2018 the Author(s). Published by PNAS.

Comparisons of Growth and Survival Performance Among Selected Families and Wild Populations of Fenneropenaeus chinensis

NASA Astrophysics Data System (ADS)

Luo, Kun; Kong, Jie; Meng, Xianhong; Luan, Sheng; Cao, Baoxiang; Chen, Baolong

2018-04-01

In this study, families of selected population for growth (SP_BWT), selected population for white spot syndrome virus (WSSV) resistance (SP_RW), Bohai wild population (WP_BH) and Huanghai wild population (WP_HH) of F. chinensis were constructed through artificial insemination and with the standardized procedure of larvae rearing. Growth and survival performance were studied among four populations after a 70 days common test. The results showed that the maximum least square mean of body weight was 17.50 g in SP_BWT while the minimum was 13.03 g in WP_HH. Compared with WP_BH, body weight of SP_BWT increased by 23.41% ( P < 0.01) and that of SP_RW by 12.20% ( P > 0.05). Body weights of SP_BWT and SP_RW were significantly higher than that of WP_HH, which increased by 34.31% ( P < 0.01) and 22.10% ( P < 0.05), respectively. The mean AGR of four populations was 0.19, 0.18, 0.17 and 0.16 g d-1, respectively. Coefficient of variation of body weight among four populations was high, which ranged from 32.67% to 35.25%. Such a range showed that there was the potentiality for further improvement in selected populations. Coefficient of variation of survival rate among four populations was low, varying between 3.20% and 5.90%. The difference of survival was highly significant ( P < 0.01) between SP_BWT and WP_BH, and significant ( P < 0.05) between SP_RW and WP_BH. However, no significant difference among other populations ( P < 0.05) was observed. Different growth performances were also observed among different families in each population. The body weight of 798F family was the highest. The absolute growth rate (AGR) was 0.25 g d-1, 150% higher than that of the lowest one, 0.1 g d-1 in 807F family. Survival rate of families among four populations was different. The highest was 94.74%, and the lowest was 71.88%.

Demographic analysis of Lost River sucker and shortnose sucker populations in Upper Klamath Lake, Oregon

USGS Publications Warehouse

Janney, E.C.; Shively, R.S.; Hayes, B.S.; Barry, P.M.; Perkins, D.

2008-01-01

We used 13 years (1995-2007) of capture-mark-recapture data to assess population dynamics of endangered Lost River suckers Deltistes luxatus and shortnose suckers Chasmistes brevirostris in Upper Klamath Lake, Oregon. The Cormack-Jolly-Seber method was used to estimate survival, and information theoretic modeling was used to assess variation due to time, gender, species, and spawning subpopulations. Length data were used to detect multiple year-class failures and events of high recruitment into adult spawning populations. Average annual survival probability was 0.88 for Lost River suckers and 0.76 for shortnose suckers. Mean life span estimates based on these survival rates indicated that Lost River suckers survived long enough on average to attempt reproduction eight times, whereas shortnose suckers only survived to spawn three to four times. Shortnose sucker survival was not only poor in years of fish kills (1995-1997) but also was low in years without fish kills (i.e., 2002 and 2004). This suggests that high mortality occurs in some years but is not necessarily associated with fish kills. Annual survival probabilities were not only different between the two species but also differed between two spawning subpopulations of Lost River suckers. Length composition data indicated that recruitment into spawning populations only occurred intermittently. Populations of both species transitioned from primarily old individuals with little size diversity and consistently poor recruitment in the late 1980s and early 1990s to mostly small, recruit-sized fish by the late 1990s. A better understanding of the factors influencing adult survival and recruitment into spawning populations is needed. Monitoring these vital parameters will provide a quantitative means to evaluate population status and assess the effectiveness of conservation and recovery efforts.

Regional differences in population-based cancer survival between six prefectures in Japan: application of relative survival models with funnel plots.

PubMed

Ito, Yuri; Ioka, Akiko; Tsukuma, Hideaki; Ajiki, Wakiko; Sugimoto, Tomoyuki; Rachet, Bernard; Coleman, Michel P

2009-07-01

We used new methods to examine differences in population-based cancer survival between six prefectures in Japan, after adjustment for age and stage at diagnosis. We applied regression models for relative survival to data from population-based cancer registries covering each prefecture for patients diagnosed with stomach, lung, or breast cancer during 1993-1996. Funnel plots were used to display the excess hazard ratio (EHR) for each prefecture, defined as the excess hazard of death from each cancer within 5 years of diagnosis relative to the mean excess hazard (in excess of national background mortality by age and sex) in all six prefectures combined. The contribution of age and stage to the EHR in each prefecture was assessed from differences in deviance-based R(2) between the various models. No significant differences were seen between prefectures in 5-year survival from breast cancer. For cancers of the stomach and lung, EHR in Osaka prefecture were above the upper 95% control limits. For stomach cancer, the age- and stage-adjusted EHR in Osaka were 1.29 for men and 1.43 for women, compared with Fukui and Yamagata. Differences in the stage at diagnosis of stomach cancer appeared to explain most of this excess hazard (61.3% for men, 56.8% for women), whereas differences in age at diagnosis explained very little (0.8%, 1.3%). This approach offers the potential to quantify the impact of differences in stage at diagnosis on time trends and regional differences in cancer survival. It underlines the utility of population-based cancer registries for improving cancer control.

Recent cancer survival in Germany: an analysis of common and less common cancers.

PubMed

Jansen, Lina; Castro, Felipe A; Gondos, Adam; Krilaviciute, Agne; Barnes, Benjamin; Eberle, Andrea; Emrich, Katharina; Hentschel, Stefan; Holleczek, Bernd; Katalinic, Alexander; Brenner, Hermann

2015-06-01

The monitoring of cancer survival by population-based cancer registries is a prerequisite to evaluate the current quality of cancer care. Our study provides 1-, 5- and 10-year relative survival as well as 5-year relative survival conditional on 1-year survival estimates and recent survival trends for Germany using data from 11 population-based cancer registries, covering around one-third of the German population. Period analysis was used to estimate relative survival for 24 common and 11 less common cancer sites for the period 2007-2010. The German and the United States survival estimates were compared using the Surveillance, Epidemiology and End Results 13 database. Trends in cancer survival in Germany between 2002-2004 and 2008-2010 were described. Five-year relative survival increased in Germany from 2002-2004 to 2008-2010 for most cancer sites. Among the 24 most common cancers, largest improvements were seen for multiple myeloma (8.0% units), non-Hodgkin lymphoma (6.2% units), prostate cancer (5.2% units) and colorectal cancer (4.6% units). In 2007-2010, the survival disadvantage in Germany compared to the United States was largest for cancers of the mouth/pharynx (-11.0% units), thyroid (-6.8% units) and prostate (-7.5% units). Although survival estimates were much lower for elderly patients in both countries, differences in age patterns were observed for some cancer sites. The reported improvements in cancer survival might reflect advances in the quality of cancer care on the population level as well as increased use of screening in Germany. The survival differences across countries and the survival disadvantage in the elderly require further investigation. © 2014 UICC.

Sex-based differences in the adaptive value of social behavior contrasted against morphology and environment.

PubMed

Vander Wal, E; Festa-Bianchet, M; Réale, D; Coltman, D W; Pelletier, F

2015-03-01

The adaptive nature of sociality has long been a central question in ecology and evolution. However, the relative importance of social behavior for fitness, compared to morphology and environment, remains largely unknown. We assessed the importance of sociality for fitness (lamb production and survival) in a population of mark6d bighorn sheep (Ovis canadensis) over 16 years (n = 1022 sheep-years). We constructed social networks from observations (n = 38,350) of group membership (n = 3150 groups). We then tested whether consistent individual differences in social behavior (centrality) exist and evaluated their relative importance compared to factors known to affect fitness: mass, age, parental effects, and population density. Sheep exhibited consistent individual differences in social centrality. Controlling for maternal carryover effects and age, the positive effect of centrality in a social network on adult female lamb production and survival was equal or greater than the effect of body mass or population density. Social centrality had less effect on male survival and no effect on adult male lamb production or lamb survival. Through its effect on lamb production and survival, sociality in fission-fusion animal societies may ultimately influence population dynamics equally or more than morphological or environmental effects.

The non-linear, interactive effects of population density and climate drive the geographical patterns of waterfowl survival

USGS Publications Warehouse

Zhao, Qing; Boomer, G. Scott; Kendall, William L.

2018-01-01

On-going climate change has major impacts on ecological processes and patterns. Understanding the impacts of climate on the geographical patterns of survival can provide insights to how population dynamics respond to climate change and provide important information for the development of appropriate conservation strategies at regional scales. It is challenging to understand the impacts of climate on survival, however, due to the fact that the non-linear relationship between survival and climate can be modified by density-dependent processes. In this study we extended the Brownie model to partition hunting and non-hunting mortalities and linked non-hunting survival to covariates. We applied this model to four decades (1972–2014) of waterfowl band-recovery, breeding population survey, and precipitation and temperature data covering multiple ecological regions to examine the non-linear, interactive effects of population density and climate on waterfowl non-hunting survival at a regional scale. Our results showed that the non-linear effect of temperature on waterfowl non-hunting survival was modified by breeding population density. The concave relationship between non-hunting survival and temperature suggested that the effects of warming on waterfowl survival might be multifaceted. Furthermore, the relationship between non-hunting survival and temperature was stronger when population density was higher, suggesting that high-density populations may be less buffered against warming than low-density populations. Our study revealed distinct relationships between waterfowl non-hunting survival and climate across and within ecological regions, highlighting the importance of considering different conservation strategies according to region-specific population and climate conditions. Our findings and associated novel modelling approach have wide implications in conservation practice.

Demographic responses to weather fluctuations are context dependent in a long-lived amphibian.

PubMed

Cayuela, Hugo; Arsovski, Dragan; Thirion, Jean-Marc; Bonnaire, Eric; Pichenot, Julian; Boitaud, Sylvain; Miaud, Claude; Joly, Pierre; Besnard, Aurélien

2016-08-01

Weather fluctuations have been demonstrated to affect demographic traits in many species. In long-lived organisms, their impact on adult survival might be buffered by the evolution of traits that reduce variation in interannual adult survival. For example, skipping breeding is an effective behavioral mechanism that may limit yearly variation in adult survival when harsh weather conditions occur; however, this in turn would likely lead to strong variation in recruitment. Yet, only a few studies to date have examined the impact of weather variation on survival, recruitment and breeding probability simultaneously in different populations of the same species. To fill this gap, we studied the impact of spring temperatures and spring rainfall on survival, on reproductive skipping behavior and on recruitment in five populations of a long-lived amphibian, the yellow-bellied toad (Bombina variegata). Based on capture-recapture data, our findings demonstrate that survival depends on interactions between age, population and weather variation. Varying weather conditions in the spring result in strong variation in the survival of immature toads, whereas they have little effect on adult toads. Breeding probability depends on both the individual's previous reproductive status and on the weather conditions during the current breeding season, leading to high interannual variation in recruitment. Crucially, we found that the impact of weather variation on demographic traits is largely context dependent and may thus differ sharply between populations. Our results suggest that studies predicting the impact of climate change on population dynamics should be taken with caution when the relationship between climate and demographic traits is established using only one population or few populations. We therefore highly recommend further research that includes surveys replicated in a substantial number of populations to account for context-dependent variation in demographic processes. © 2016 John Wiley & Sons Ltd.

Effect of experimental manipulation on survival and recruitment of feral pigs

USGS Publications Warehouse

Hanson, L.B.; Mitchell, M.S.; Grand, J.B.; Jolley, D.B.; Sparklin, B.D.; Ditchkoff, S.S.

2009-01-01

Lethal removal is commonly used to reduce the density of invasive-species populations, presuming it reduces population growth rate; the actual effect of lethal removal on the vital rates contributing to population growth, however, is rarely tested. We implemented a manipulative experiment of feral pig (Sus scrofa) populations at Fort Benning, Georgia, USA, to assess the demographic effects of harvest intensity. Using markrecapture data, we estimated annual survival, recruitment, and population growth rates of populations in a moderately harvested area and a heavily harvested area for 200406. Population growth rates did not differ between the populations. The top-ranked model for survival included a harvest intensity effect; model-averaged survival was lower for the heavily harvested population than for the moderately harvested population. Increased immigration and reproduction likely compensated for the increased mortality in the heavily harvested population. We conclude that compensatory responses in feral pig recruitment can limit the success of lethal control efforts. ?? 2009 CSIRO.

Cancer of the ovary, fallopian tube, and peritoneum: a population-based comparison of the prognostic factors and outcomes.

PubMed

Rottmann, Miriam; Burges, A; Mahner, S; Anthuber, C; Beck, T; Grab, D; Schnelzer, A; Kiechle, M; Mayr, D; Pölcher, M; Schubert-Fritschle, G; Engel, J

2017-09-01

The objective was to compare the prognostic factors and outcomes among primary ovarian cancer (OC), fallopian tube cancer (FC), and peritoneal cancer (PC) patients in a population-based setting. We analysed 5399 OC, 327 FC, and 416 PC patients diagnosed between 1998 and 2014 in the catchment area of the Munich Cancer Registry (meanwhile 4.8 million inhabitants). Tumour site differences were examined by comparing prognostic factors, treatments, the time to progression, and survival. The effect of the tumour site was additionally analysed by a Cox regression model. The median age at diagnosis, histology, and FIGO stage significantly differed among the tumour sites (p < 0.001); PC patients were older, more often diagnosed with a serous subtype, and in FIGO stage III or IV. The time to progression and survival significantly differed among the tumour sites. When stratified by FIGO stage, the differences in time to progression disappeared, and the differences in survival considerably weakened. The differences in the multivariate survival analysis showed an almost identical outcome in PC patients (HR 1.07 [0.91-1.25]) and an improved survival of FC patients (HR 0.63 [0.49-0.81]) compared to that of OC patients. The comparison of OC, FC, and PC patients in this large-scale population-based study showed differences in the prognostic factors. These differences primarily account for the inferior outcome of PC patients, and for the improved survival of FC compared to OC patients.

Survival and recovery rates of American woodcock banded in Michigan

USGS Publications Warehouse

Krementz, David G.; Hines, James E.; Luukkonen, David R.

2003-01-01

American woodcock (Scolopax minor) population indices have declined since U.S. Fish and Wildlife Service (USFWS) monitoring began in 1968. Management to stop and/or reverse this population trend has been hampered by the lack of recent information on woodcock population parameters. Without recent information on survival rate trends, managers have had to assume that the recent declines in recruitment indices are the only parameter driving woodcock declines. Using program MARK, we estimated annual survival and recovery rates of adult and juvenile American woodcock, and estimated summer survival of local (young incapable of sustained flight) woodcock banded in Michigan between 1978 and 1998. We constructed a set of candidate models from a global model with age (local, juvenile, adult) and time (year)-dependent survival and recovery rates to no age or time-dependent survival and recovery rates. Five models were supported by the data, with all models suggesting that survival rates differed among age classes, and 4 models had survival rates that were constant over time. The fifth model suggested that juvenile and adult survival rates were linear on a logit scale over time. Survival rates averaged over likelihood-weighted model results were 0.8784 +/- 0.1048 (SE) for locals, 0.2646 +/- 0.0423 (SE) for juveniles, and 0.4898 +/- 0.0329 (SE) for adults. Weighted average recovery rates were 0.0326 +/- 0.0053 (SE) for juveniles and 0.0313 +/- 0.0047 (SE) for adults. Estimated differences between our survival estimates and those from prior years were small, and our confidence around those differences was variable and uncertain. juvenile survival rates were low.

Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis)

PubMed Central

Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

2014-01-01

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes. PMID:24552840

Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis).

PubMed

Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

2014-04-07

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes.

WAERS: an application for Web-assisted estimation of relative survival.

PubMed

Clèries, Ramon; Valls, Joan; Esteban, Laura; Gálvez, Jordi; Pareja, Laura; Sanz, Xavier; Alliste, Luisa; Martínez, José Miguel; Moreno, Víctor; Bosch, Xavier; Borràs, Josep Maria; Ribes, Josepa Maria

2007-09-01

Net cancer survival estimation is usually performed by computing relative survival (RS), which is defined as the ratio between observed and expected survival rates. The mortality of a reference population is required in order to compute the expected survival rate, which can be performed using a variety of statistical packages. A new Web interface to compute RS, called WAERS, has been developed by the Catalan Institute of Oncology. The reference population is first selected, and then the RS of a cohort is computed. A remote server is used for this purpose. A mock example serves to illustrate the use of the tool with a hypothetical cohort, for which RS is estimated based on three different reference populations (a province of Spain, an autonomous community (Region), and the entire Spanish population). At present, only mortality tables for different areas of Spain are available. Future improvements of this application will include mortality tables of Latin American and European Union countries, and stratified (control variable) analysis. This application can be also useful for cohort mortality studies and for registries of several diseases.

Effects of yearling, juvenile and adult survival on reef manta ray (Manta alfredi) demography

PubMed Central

van der Ouderaa, Isabelle B.C.; Tibiriçá, Yara

2016-01-01

Background The trade in manta ray gill plates has considerably increased over the last two decades. The resulting increases in ray mortality, in addition to mortality caused by by-catch, has caused many ray populations to decrease in size. The aim of this study was to ascertain how yearling and juvenile growth and survival, and adult survival and reproduction affect reef manta ray (Manta alfredi) population change, to increase our understanding of manta ray demography and thereby improve conservation research and measures for these fish. Methods We developed a population projection model for reef manta rays, and used published life history data on yearling and juvenile growth and adult reproduction to parameterise the model. Because little is known about reef manta ray yearling and juvenile survival, we conducted our analyses using a range of plausible survival rate values for yearlings, juveniles and adults. Results The model accurately captured observed variation in population growth rate, lifetime reproductive success and cohort generation time in different reef manta ray populations. Our demographic analyses revealed a range of population consequences in response to variation in demographic rates. For example, an increase in yearling or adult survival rates always elicited greater responses in population growth rate, lifetime reproductive success and cohort generation time than the same increase in juvenile survival rate. The population growth rate increased linearly, but lifetime reproductive success and cohort generation time increased at an accelerating rate with increasing yearling or adult survival rates. Hence, even a small increase in survival rate could increase lifetime reproductive success by one pup, and cohort generation time by several years. Elasticity analyses revealed that, depending on survival rate values of all life stages, the population growth rate is either most sensitive to changes in the rate with which juveniles survive but stay juveniles (i.e., do not mature into adults) or to changes in adult survival rate. However, when assessing these results against estimates on population growth and adult survival rates for populations off the coasts of Mozambique and Japan, we found that the population growth rate is predicted to be always most sensitive to changes in the adult survival rate. Discussion It is important to gain an in-depth understanding of reef manta ray life histories, particularly of yearling and adult survival rates, as these can influence reef manta ray population dynamics in a variety of ways. For declining populations in particular, it is crucial to know which life stage should be targeted for their conservation. For one such declining population off the coast of Mozambique, adult annual survival rate has the greatest effect on population growth, and by increasing adult survival by protecting adult aggregation sites, this population’s decline could be halted or even reversed. PMID:27635337

Projecting demographic responses to climate change: adult and juvenile survival respond differently to direct and indirect effects of weather in a passerine population

USGS Publications Warehouse

Dybala, Kristen E.; Eadie, John M.; Gardali, Thomas; Seavy, Nathaniel E.; Herzog, Mark P.

2013-01-01

Few studies have quantitatively projected changes in demography in response to climate change, yet doing so can provide important insights into the processes that may lead to population declines and changes in species distributions. Using a long-term mark-recapture data set, we examined the influence of multiple direct and indirect effects of weather on adult and juvenile survival for a population of Song Sparrows (Melospiza melodia) in California. We found evidence for a positive, direct effect of winter temperature on adult survival, and a positive, indirect effect of prior rainy season precipitation on juvenile survival, which was consistent with an effect of precipitation on food availability during the breeding season. We used these relationships, and climate projections of significantly warmer and slightly drier winter weather by the year 2100, to project a significant increase in mean adult survival (12-17%) and a slight decrease in mean juvenile survival (4-6%) under the B1 and A2 climate change scenarios. Together with results from previous studies on seasonal fecundity and postfledging survival in this population, we integrated these results in a population model and projected increases in the population growth rate under both climate change scenarios. Our results underscore the importance of considering multiple, direct, and indirect effects of weather throughout the annual cycle, as well as differences in the responses of each life stage to climate change. Projecting demographic responses to climate change can identify not only how populations will be affected by climate change but also indicate the demographic process(es) and specific mechanisms that may be responsible. This information can, in turn, inform climate change adaptation plans, help prioritize future research, and identify where limited conservation resources will be most effectively and efficiently spent.

Winter survival of adult female harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill

USGS Publications Warehouse

Esler, Daniel N.; Schmutz, J.A.; Jarvis, R.L.; Mulcahy, D.M.

2000-01-01

Harlequin duck (Histrionicus histrionicus) life-history characteristics make their populations particularly vulnerable to perturbations during nonbreeding periods. The 1989 Exxon Valdez oil spill was a major perturbation to nonbreeding habitats of harlequin ducks in Prince William Sound, Alaska, which resulted in population injury. To assess the status of population recovery from the oil spill and to evaluate factors potentially constraining full recovery, we used radiotelemetry to examine survival of adult female harlequin ducks during winters of 1995-96, 1996-97, and 1997-98. We implanted 294 harlequin ducks (154 and 140 in oiled and unoiled areas, respectively) with transmitters and tracked their signals from aircraft during October through March. We examined variation in survival rates relative to area and season (early, mid, and late winter) through comparisons of models using Akaike's information criterion (AIC(c)) values. The 3 models best supported by the data indicated that survival of birds in oiled areas was lower than in unoiled areas. Inclusion of standardized body mass during wing molt in the 3 best models did not improve their fit, indicating that body mass during wing molt did not affect subsequent winter survival. In the model that best fit our data, survival was high in early winter for both areas, lower during mid and late winter seasons, and lowest in oiled areas during mid winter. Cumulative winter survival estimated from this model was 78.0% (SE = 3.3%) in oiled areas and 83.7% (SE = 2.9%) in unoiled areas. We determined that area differences in survival were more likely related to oiling history than intrinsic geographic differences. Based on a demographic model, area differences in survival offer a likely mechanism for observed declines in populations on oiled areas. Concurrent studies indicated that harlequin ducks continued to be exposed to residual Exxon Valdez oil as much as 9 years after the spill. We suggest that oil exposure, mortality, and population dynamics were linked and conclude that continued effects of the oil spill likely restricted recovery of harlequin duck populations through at least 1998.

Valuing the chances of survival of two distinct Eurasian lynx populations in Poland - do people want to keep the doors open?

PubMed

Bartczak, Anna; Meyerhoff, Jürgen

2013-11-15

This study investigates individuals' preferences toward protection programs aimed at increasing the chances of survival of the two distinct Eurasian lynx populations in Poland. Those two groups, the Lowland and the Carpathian population, are exposed to different risks of extinction as they have different numbers, different-sized areas of occupation and different migration possibilities. Using a discrete choice experiment we examine the influence of the initial degree of endangerment on the allocation of respondents' funds. The results show that people prefer to invest in the conservation of the lynx population, which has initially lower chances of survival. The main driver of respondents' choices seems to be loss aversion rather than the urge to invest in an option with an expected higher outcome. This observation can be interpreted as people trying to keep all the options - doors - open by devoting more funds to the more vulnerable population than to the more stable one. Employing a scale-extended latent class model allowed us to detect segments among individuals showing different types of response behavior, including a form of serial non-participation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Estimation of survival of adult Florida manatees in the Crystal River, at Blue Spring, and on the Atlantic Coast

USGS Publications Warehouse

O'Shea, Thomas J.; Langtimm, Catherine A.; O'Shea, Thomas J.; Ackerman, B.B.; Percival, H. Franklin

1995-01-01

We applied Cormack-Jolly-Seber open population models to manatee (Trichechus manatus latirostris) photo-identification databases to estimate adult survival probabilities. The computer programs JOLLY and RECAPCO were used to estimate survival of 677 individuals in three study areas: Crystal River (winters 1977-78 to 1990-91), Blue Spring (winters 1977-78 to 1990-91), and the Atlantic Coast (winters 1984-85 to 1990-91). We also estimated annual survival from observations of 111 manatees tagged for studies with radiotelemetry. Survival estimated from observations with telemetry had broader confidence intervals than survival estimated with the Cormack-Jolly-Seber models. Annual probabilities of capture based on photo-identification records were generally high. The mean annual adult survival estimated from sighting-resighting records was 0.959-0.962 in the Crystal River and 0.936-0.948 at Blue Spring and may be high enough to permit population growth, given the values of other life-history parameters. On the Atlantic Coast, the estimated annual adult survival (range of means = 0.877-0.885) may signify a declining population. However, for several reasons, interpretation of data from the latter study group should be tempered with caution. Adult survivorship seems to be constant with age in all three study groups. No strong differences were apparent between adult survival ofmales and females in the Crystal River or at Blue Spring; the basis of significant differences between sexes on the Atlantic Coast is unclear. Future research into estimating survival with photo-identification and the Cormack-Jolly-Seber models should be vigorously pursued. Estimates of annual survival can provide an additional indication of Florida manatee population status with a stronger statistical basis than aerial counts and carcass totals.

White-Black Differences in Cancer Incidence, Stage at Diagnosis, and Survival among Adults Aged 85 Years and Older in the United States.

PubMed

Krok-Schoen, Jessica L; Fisher, James L; Baltic, Ryan D; Paskett, Electra D

2016-11-01

Increased life expectancy, growth of minority populations, and advances in cancer screening and treatment have resulted in an increasing number of older, racially diverse cancer survivors. Potential black/white disparities in cancer incidence, stage, and survival among the oldest old (≥85 years) were examined using data from the SEER Program of the National Cancer Institute. Differences in cancer incidence and stage at diagnosis were examined for cases diagnosed within the most recent 5-year period, and changes in these differences over time were examined for white and black cases aged ≥85 years. Five-year relative cancer survival rate was also examined by race. Among those aged ≥85 years, black men had higher colorectal, lung and bronchus, and prostate cancer incidence rates than white men, respectively. From 1973 to 2012, lung and bronchus and female breast cancer incidence increased, while colorectal and prostate cancer incidence decreased among this population. Blacks had higher rates of unstaged cancer compared with whites. The 5-year relative survival rate for all invasive cancers combined was higher for whites than blacks. Notably, whites had more than three times the relative survival rate of lung and bronchus cancer when diagnosed at localized (35.1% vs. 11.6%) and regional (12.2% vs. 3.2%) stages than blacks, respectively. White and black differences in cancer incidence, stage, and survival exist in the ≥85 population. Continued efforts are needed to reduce white and black differences in cancer prevention and treatment among the ≥85 population. Cancer Epidemiol Biomarkers Prev; 25(11); 1517-23. ©2016 AACR. ©2016 American Association for Cancer Research.

Breast cancer patients survival and associated factors: reported outcomes from the Southern Cancer Registry in Portugal.

PubMed

André, Maria Rosario; Amaral, Sandra; Mayer, Alexandra; Miranda, Ana

2014-01-01

Although the breast cancer incidence in Portugal is lower than the European average, it is the most frequent cancer in women. Overall, mortality rates are heterogeneous throughout Portugal. Implicated factors may include demographic and socioeconomic aspects, tumor biological characteristics, and access to medical care. The aim of this study is to detect survival differences in female breast cancer and identify the main associated factors. We have conducted a population-based, retrospective cohort study with follow-up. Incident breast cancer cases diagnosed in 2005 of residents in the southern region of Portugal were included. Data was collected from the Southern Portugal Cancer Registry (ROR-Sul) database and completed with clinical chart information. A total of 1 354 patients were included in this study. Observed geographical variations were as follows: for age distribution, with an aging population in Alentejo; for tumor sub-types, there was a higher incidence of HER2-positive tumors in the Algarve and a higher incidence of HER2-negative tumors in Região Autónoma da Madeira. Reported estimated 5-year overall survival was 80%, with significant association with tumor stage, hormone receptor and HER2 status. No survival differences were identified among women from distinct geographical regions. Although we found differences in age and tumor sub-type distribution between geographical regions, our study does not support the existence of discrepancies in breast cancer survival between these regions. Tumor biological characteristics seem to be the main associated factor with breast cancer survival in our population. Our study confirms the association between patient survival and tumor stage, hormone receptor and HER2 status. However, no differences in patient survival were observed among different regions of residence.

Survival in macaroni penguins and the relative importance of different drivers: individual traits, predation pressure and environmental variability

PubMed Central

Horswill, Catharine; Matthiopoulos, Jason; Green, Jonathan A; Meredith, Michael P; Forcada, Jaume; Peat, Helen; Preston, Mark; Trathan, Phil N; Ratcliffe, Norman

2014-01-01

Understanding the demographic response of free-living animal populations to different drivers is the first step towards reliable prediction of population trends. Penguins have exhibited dramatic declines in population size, and many studies have linked this to bottom-up processes altering the abundance of prey species. The effects of individual traits have been considered to a lesser extent, and top-down regulation through predation has been largely overlooked due to the difficulties in empirically measuring this at sea where it usually occurs. For 10 years (2003–2012), macaroni penguins (Eudyptes chrysolophus) were marked with subcutaneous electronic transponder tags and re-encountered using an automated gateway system fitted at the entrance to the colony. We used multistate mark–recapture modelling to identify the different drivers influencing survival rates and a sensitivity analysis to assess their relative importance across different life stages. Survival rates were low and variable during the fledging year (mean = 0·33), increasing to much higher levels from age 1 onwards (mean = 0·89). We show that survival of macaroni penguins is driven by a combination of individual quality, top-down predation pressure and bottom-up environmental forces. The relative importance of these covariates was age specific. During the fledging year, survival rates were most sensitive to top-down predation pressure, followed by individual fledging mass, and finally bottom-up environmental effects. In contrast, birds older than 1 year showed a similar response to bottom-up environmental effects and top-down predation pressure. We infer from our results that macaroni penguins will most likely be negatively impacted by an increase in the local population size of giant petrels. Furthermore, this population is, at least in the short term, likely to be positively influenced by local warming. More broadly, our results highlight the importance of considering multiple causal effects across different life stages when examining the survival rates of seabirds. PMID:24846695

Age at Vaccination May Influence Response to Sylvatic Plague Vaccine (SPV) in Gunnison's Prairie Dogs (Cynomys gunnisoni).

PubMed

Rocke, Tonie E; Tripp, Dan; Lorenzsonn, Faye; Falendysz, Elizabeth; Smith, Susan; Williamson, Judy; Abbott, Rachel

2015-06-01

Gunnison's prairie dogs (Cynomys gunnisoni) have been considered at greater risk from Yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. To test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (SPV) improved survival, we captured prairie dogs from a C. g. gunnisoni or "montane" population and a C. g. zuniensis or "prairie" population for vaccine efficacy and challenge studies. No differences (P = 0.63) were found in plague susceptibility in non-vaccinated animals between these two populations; however, vaccinates from the prairie population survived plague challenge at significantly higher rates (P < 0.01) than those from the montane population. Upon further analysis, we determined that response to immunization was most likely associated with differences in age, as the prairie group was much younger on average than the montane group. Vaccinates that were juveniles or young adults survived plague challenge at a much higher rate than adults (P < 0.01 and P = 0.02, respectively), but no difference (P = 0.83) was detected in survival rates between control animals of different ages. These results suggest that host susceptibility is probably not related to the assumed greater risk from plague in the C. g. gunnisoni or "montane" populations of Gunnison's prairie dogs, and that SPV could be a useful plague management tool for this species, particularly if targeted at younger cohorts.

Resource allocation and post-reproductive degeneration in the freshwater cnidarian Hydra oligactis (Pallas, 1766).

PubMed

Tökölyi, Jácint; Ősz, Zsófia; Sebestyén, Flóra; Barta, Zoltán

2017-02-01

Freshwater hydra are among the few animal groups that show negligible senescence and can maintain high survival and reproduction rates when kept under stable conditions in the laboratory. Yet, one species of Hydra (H. oligactis) undergoes a senescence-like process in which polyps degenerate and die after sexual reproduction. The ultimate factors responsible for this phenomenon are unclear. High mortality in reproducing animals could be the consequence of increased allocation of resources to reproduction at the expense of somatic maintenance. This hypothesis predicts that patterns of reproduction and survival are influenced by resource availability. To test this prediction we investigated survival and reproduction at different levels of food availability in 10 lineages of H. oligactis derived from a single Hungarian population. Sexual reproduction was accompanied by reduced survival, but a substantial proportion of animals regenerated after sexual reproduction and continued reproducing asexually. Polyps belonging to different lineages showed differences in their propensity to initiate sexual reproduction, gonad number and survival rate. Food availability significantly affected fecundity (number of eggs or testes produced), with the largest number of gonads being produced by animals kept on a high food regime. On the other hand, survival rate was not affected by the amount of food. These results show that survival is conserved at the expense of reproduction in this population when food is low. It remains a question still to be answered why survival is prioritized over reproduction in this population. Copyright © 2016 Elsevier GmbH. All rights reserved.

Potential Factors Affecting Survival Differ by Run-Timing and Location: Linear Mixed-Effects Models of Pacific Salmonids (Oncorhynchus spp.) in the Klamath River, California

PubMed Central

Quiñones, Rebecca M.; Holyoak, Marcel; Johnson, Michael L.; Moyle, Peter B.

2014-01-01

Understanding factors influencing survival of Pacific salmonids (Oncorhynchus spp.) is essential to species conservation, because drivers of mortality can vary over multiple spatial and temporal scales. Although recent studies have evaluated the effects of climate, habitat quality, or resource management (e.g., hatchery operations) on salmonid recruitment and survival, a failure to look at multiple factors simultaneously leaves open questions about the relative importance of different factors. We analyzed the relationship between ten factors and survival (1980–2007) of four populations of salmonids with distinct life histories from two adjacent watersheds (Salmon and Scott rivers) in the Klamath River basin, California. The factors were ocean abundance, ocean harvest, hatchery releases, hatchery returns, Pacific Decadal Oscillation, North Pacific Gyre Oscillation, El Niño Southern Oscillation, snow depth, flow, and watershed disturbance. Permutation tests and linear mixed-effects models tested effects of factors on survival of each taxon. Potential factors affecting survival differed among taxa and between locations. Fall Chinook salmon O. tshawytscha survival trends appeared to be driven partially or entirely by hatchery practices. Trends in three taxa (Salmon River spring Chinook salmon, Scott River fall Chinook salmon; Salmon River summer steelhead trout O. mykiss) were also likely driven by factors subject to climatic forcing (ocean abundance, summer flow). Our findings underscore the importance of multiple factors in simultaneously driving population trends in widespread species such as anadromous salmonids. They also show that the suite of factors may differ among different taxa in the same location as well as among populations of the same taxa in different watersheds. In the Klamath basin, hatchery practices need to be reevaluated to protect wild salmonids. PMID:24866173

Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations.

PubMed

Bradley, Paul W; Gervasi, Stephanie S; Hua, Jessica; Cothran, Rickey D; Relyea, Rick A; Olson, Deanna H; Blaustein, Andrew R

2015-10-01

Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies. We experimentally investigated intraspecific differences in host sensitivity to Bd across 10 populations of wood frogs (Lithobates sylvaticus) raised from eggs to metamorphosis. We exposed the post-metamorphic wood frogs to Bd and monitored survival for 30 days under controlled laboratory conditions. Populations differed in overall survival and mortality rate. Infection load also differed among populations but was not correlated with population differences in risk of mortality. Such population-level variation in sensitivity to Bd may result in reservoir populations that may be a source for the transmission of Bd to other sensitive populations or species. Alternatively, remnant populations that are less sensitive to Bd could serve as sources for recolonization after epidemic events. © 2015 Society for Conservation Biology.

Increased survival and prolonged longevity mainly contribute to the temperature-adaptive evolutionary strategy in invasive Bemisia tabaci (Hemiptera: Aleyrodidae) Middle East Asia Minor 1.

PubMed

Lü, Zhi-Chuang; Gao, Qing-Lei; Wan, Fang-Hao; Yu, Hao; Guo, Jian-Ying

2014-10-15

With increasing global climate change, analyses of stress-inducing conditions have important significance in ecological adaptation and the biological distribution of species. To reveal the difference in temperature-adaptive strategy between Turpan and Beijing populations of Bemisia tabaci (Gennadius) Middle East Asia Minor 1 (MEAM1) under high-temperature stress conditions, we compared thermal tolerance and life history traits between Beijing and Turpan populations of MEAM1 after exposure to different heat shock treatments for different times. The experimental design reflected the nature of heat stress conditions suffered by MEAM1. The results showed that eggs, red-eyed pupae, and adults of the Turpan population were more heat tolerant than those of the Beijing population under the same stress conditions. Additionally, it was found that longevity and F1 adult survival rate were significantly higher in the Turpan population than in the Beijing population after heat shock stress, but egg number and F1 female ratio were not significantly different between Turpan population and Beijing population. Overall, it was suggested that heat tolerance and longevity traits were the most relevant for climate characteristics and not reproductive traits, and improved heat tolerance and prolonged longevity were important adaptive strategies that helped MEAM1 to survive in harsh high-temperature conditions such as Turpan arid desert climate. The present results provided further insight into the modes of heat tolerance and the ways in which survival and longevity traits respond to environmental selection pressures. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

A historical estimate of apparent survival of American oystercatcher (Haematopus palliatus) in Virginia

USGS Publications Warehouse

Nol, Erica; Murphy, Sean P.; Cadman, Michael D.

2012-01-01

Using mark-recapture models, apparent survival was estimated from older banding and re-sighting data (1978–1983) of American Oystercatchers (Haematopus palliatus) nesting on beaches and in salt marshes of coastal Virginia, USA. Oystercatchers nesting in salt marshes exhibited higher apparent survival (0.94 ±0.03) than birds nesting on beaches (0.81 ±0.06), a difference due to variation in mortality, permanent emigration, or both. Nesting on exposed barrier beaches may subject adults and young to higher risk of predation. These early estimates of adult survival for a species that is heavily monitored along the Atlantic and Gulf Coasts can be used to (1) develop demographic models to determine population stability, (2) compare with estimates of adult survival from populations that have reached carrying capacity, and (3) compare with estimates of survival from other oystercatcher populations and species.

Sex-specific early survival drives adult sex ratio bias in snowy plovers and impacts mating system and population growth

PubMed Central

Küpper, Clemens; Miller, Tom E. X.; Cruz-López, Medardo; Maher, Kathryn H.; dos Remedios, Natalie; Stoffel, Martin A.; Hoffman, Joseph I.; Krüger, Oliver; Székely, Tamás

2017-01-01

Adult sex ratio (ASR) is a central concept in population biology and a key factor in sexual selection, but why do most demographic models ignore sex biases? Vital rates often vary between the sexes and across life history, but their relative contributions to ASR variation remain poorly understood—an essential step to evaluate sex ratio theories in the wild and inform conservation. Here, we combine structured two-sex population models with individual-based mark–recapture data from an intensively monitored polygamous population of snowy plovers. We show that a strongly male-biased ASR (0.63) is primarily driven by sex-specific survival of juveniles rather than adults or dependent offspring. This finding provides empirical support for theories of unbiased sex allocation when sex differences in survival arise after the period of parental investment. Importantly, a conventional model ignoring sex biases significantly overestimated population viability. We suggest that sex-specific population models are essential to understand the population dynamics of sexual organisms: reproduction and population growth are most sensitive to perturbations in survival of the limiting sex. Overall, our study suggests that sex-biased early survival may contribute toward mating system evolution and population persistence, with implications for both sexual selection theory and biodiversity conservation. PMID:28634289

Disentangling density-dependent dynamics using full annual cycle models and Bayesian model weight updating

USGS Publications Warehouse

Robinson, Orin J.; McGowan, Conor P.; Devers, Patrick K.

2017-01-01

Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processes such as survival and recruitment throughout the annual cycle. These effects must be accounted for when characterizing migratory populations via population models.To evaluate effects of density on seasonal survival and recruitment of a migratory species, we used an existing full annual cycle model framework for American black ducks Anas rubripes, and tested different density effects (including no effects) on survival and recruitment. We then used a Bayesian model weight updating routine to determine which population model best fit observed breeding population survey data between 1990 and 2014.The models that best fit the survey data suggested that survival and recruitment were affected by density dependence and that density effects were stronger on adult survival during the breeding season than during the non-breeding season.Analysis also suggests that regulation of survival and recruitment by density varied over time. Our results showed that different characterizations of density regulations changed every 8–12 years (three times in the 25-year period) for our population.Synthesis and applications. Using a full annual cycle, modelling framework and model weighting routine will be helpful in evaluating density dependence for migratory species in both the short and long term. We used this method to disentangle the seasonal effects of density on the continental American black duck population which will allow managers to better evaluate the effects of habitat loss and potential habitat management actions throughout the annual cycle. The method here may allow researchers to hone in on the proper form and/or strength of density dependence for use in models for conservation recommendations.

Age at vaccination may influence response to sylvatic plague vaccine (SPV) in Gunnison’s prairie dogs (Cynomys gunnisoni)

USGS Publications Warehouse

Rocke, Tonie E.; Tripp, Daniel W.; Lorenzsonn, Faye; Falendysz, Elizabeth A.; Smith, Susan; Williamson, Judy L.; Abbott, Rachel C.

2015-01-01

Gunnison’s prairie dogs (Cynomys gunnisoni) have been considered at greater risk from Yersinia pestis (plague) infection in the montane portion of their range compared to populations at lower elevations, possibly due to factors related to flea transmission of the bacteria or greater host susceptibility. To test the latter hypothesis and determine whether vaccination against plague with an oral sylvatic plague vaccine (SPV) improved survival, we captured prairie dogs from a C. g. gunnisoni or “montane” population and a C. g. zuniensis or “prairie” population for vaccine efficacy and challenge studies. No differences (P = 0.63) were found in plague susceptibility in non-vaccinated animals between these two populations; however, vaccinates from the prairie population survived plague challenge at significantly higher rates (P < 0.01) than those from the montane population. Upon further analysis, we determined that response to immunization was most likely associated with differences in age, as the prairie group was much younger on average than the montane group. Vaccinates that were juveniles or young adults survived plague challenge at a much higher rate than adults (P < 0.01 and P = 0.02, respectively), but no difference (P = 0.83) was detected in survival rates between control animals of different ages. These results suggest that host susceptibility is probably not related to the assumed greater risk from plague in the C. g. gunnisoni or “montane” populations of Gunnison’s prairie dogs, and that SPV could be a useful plague management tool for this species, particularly if targeted at younger cohorts.

Biological variation in two Anopheles vestitipennis populations with different feeding preferences in southern Mexico.

PubMed

Ulloa, Armando; Rodríguez, Mario H; Arredondo-Jimenez, Juan I; Fernandez-Salas, Ildefonso

2005-12-01

The lengths of gonotrophic cycle and egg development and survival rate were studied in Anopheles vestitipennis collected in horse and human-baited traps in southern Mexico. The gonotrophic cycle duration was estimated using cross-correlation analysis, whereas the survival rate was assessed using a vertical method. Daily changes of parity rates gave significant correlation indices at 3 and 4 days in the zoophilic and anthropophilic populations, respectively. The minimum time required to develop mature eggs after blood feeding was 54 and 60 h, and the survival rate was 0.93 and 0.88 in zoophilic and anthropophilic female mosquito populations, respectively. These biological differences provide additional support for the existence of subpopulations with distinctive feeding preferences within An. vestitipennis in southern Mexico.

Compensatory effects of recruitment and survival when amphibian populations are perturbed by disease

USGS Publications Warehouse

Muths, E.; Scherer, R. D.; Pilliod, D.S.

2011-01-01

The need to increase our understanding of factors that regulate animal population dynamics has been catalysed by recent, observed declines in wildlife populations worldwide. Reliable estimates of demographic parameters are critical for addressing basic and applied ecological questions and understanding the response of parameters to perturbations (e.g. disease, habitat loss, climate change). However, to fully assess the impact of perturbation on population dynamics, all parameters contributing to the response of the target population must be estimated. We applied the reverse-time model of Pradel in Program mark to 6years of capture-recapture data from two populations of Anaxyrus boreas (boreal toad) populations, one with disease and one without. We then assessed a priori hypotheses about differences in survival and recruitment relative to local environmental conditions and the presence of disease. We further explored the relative contribution of survival probability and recruitment rate to population growth and investigated how shifts in these parameters can alter population dynamics when a population is perturbed. High recruitment rates (0??41) are probably compensating for low survival probability (range 0??51-0??54) in the population challenged by an emerging pathogen, resulting in a relatively slow rate of decline. In contrast, the population with no evidence of disease had high survival probability (range 0??75-0??78) but lower recruitment rates (0??25). Synthesis and applications.We suggest that the relationship between survival and recruitment may be compensatory, providing evidence that populations challenged with disease are not necessarily doomed to extinction. A better understanding of these interactions may help to explain, and be used to predict, population regulation and persistence for wildlife threatened with disease. Further, reliable estimates of population parameters such as recruitment and survival can guide the formulation and implementation of conservation actions such as repatriations or habitat management aimed to improve recruitment. ?? 2011 The Authors. Journal of Applied Ecology ?? 2011 British Ecological Society.

Cancer survival in Europe 1999-2007 by country and age: results of EUROCARE--5-a population-based study.

PubMed

De Angelis, Roberta; Sant, Milena; Coleman, Michel P; Francisci, Silvia; Baili, Paolo; Pierannunzio, Daniela; Trama, Annalisa; Visser, Otto; Brenner, Hermann; Ardanaz, Eva; Bielska-Lasota, Magdalena; Engholm, Gerda; Nennecke, Alice; Siesling, Sabine; Berrino, Franco; Capocaccia, Riccardo

2014-01-01

Cancer survival is a key measure of the effectiveness of health-care systems. EUROCARE-the largest cooperative study of population-based cancer survival in Europe-has shown persistent differences between countries for cancer survival, although in general, cancer survival is improving. Major changes in cancer diagnosis, treatment, and rehabilitation occurred in the early 2000s. EUROCARE-5 assesses their effect on cancer survival in 29 European countries. In this retrospective observational study, we analysed data from 107 cancer registries for more than 10 million patients with cancer diagnosed up to 2007 and followed up to 2008. Uniform quality control procedures were applied to all datasets. For patients diagnosed 2000-07, we calculated 5-year relative survival for 46 cancers weighted by age and country. We also calculated country-specific and age-specific survival for ten common cancers, together with survival differences between time periods (for 1999-2001, 2002-04, and 2005-07). 5-year relative survival generally increased steadily over time for all European regions. The largest increases from 1999-2001 to 2005-07 were for prostate cancer (73.4% [95% CI 72.9-73.9] vs 81.7% [81.3-82.1]), non-Hodgkin lymphoma (53.8% [53.3-54.4] vs 60.4% [60.0-60.9]), and rectal cancer (52.1% [51.6-52.6] vs 57.6% [57.1-58.1]). Survival in eastern Europe was generally low and below the European mean, particularly for cancers with good or intermediate prognosis. Survival was highest for northern, central, and southern Europe. Survival in the UK and Ireland was intermediate for rectal cancer, breast cancer, prostate cancer, skin melanoma, and non-Hodgkin lymphoma, but low for kidney, stomach, ovarian, colon, and lung cancers. Survival for lung cancer in the UK and Ireland was much lower than for other regions for all periods, although results for lung cancer in some regions (central and eastern Europe) might be affected by overestimation. Survival usually decreased with age, although to different degrees depending on region and cancer type. The major advances in cancer management that occurred up to 2007 seem to have resulted in improved survival in Europe. Likely explanations of differences in survival between countries include: differences in stage at diagnosis and accessibility to good care, different diagnostic intensity and screening approaches, and differences in cancer biology. Variations in socioeconomic, lifestyle, and general health between populations might also have a role. Further studies are needed to fully interpret these findings and how to remedy disparities. Italian Ministry of Health, European Commission, Compagnia di San Paolo Foundation, Cariplo Foundation. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Natural History of Nonobstructive Hypertrophic Cardiomyopathy.

PubMed

Hebl, Virginia B; Miranda, William R; Ong, Kevin C; Hodge, David O; Bos, J Martijn; Gentile, Federico; Klarich, Kyle W; Nishimura, Rick A; Ackerman, Michael J; Gersh, Bernard J; Ommen, Steve R; Geske, Jeffrey B

2016-03-01

To describe the survival of a large nonobstructive hypertrophic cardiomyopathy (NO-HCM) cohort and to identify risk factors for increased mortality in this population. Patients were identified from the Mayo Clinic HCM database from January 1, 1975, through November 30, 2006, for this retrospective observational study. Patients with resting or provocable left ventricular outflow tract gradients were excluded. Echocardiographic, clinical, and genetic data were compared between subgroups, and survival data were compared with expected population rates. A total of 706 patients with NO-HCM were identified. During median follow-up of 5 years (mean, 7 years), there were 208 deaths. Overall survival was no different than expected compared with age- and sex-matched white US population mortality rates (P=.77). Independent predictors of death were age at diagnosis, "burned out" HCM, and history of transient ischemic attack or stroke; use of an implantable cardioverter defibrillator (ICD) was inversely related to death. After exclusion of patients with an ICD, there was no difference in survival compared with age- and sex- matched individuals (P=.39); age, previous transient ischemic attack/stroke, and burned out HCM were predictors of death. In this cohort, patients with NO-HCM had similar survival rates as age- and sex-matched white US population mortality rates. Although use of an ICD was inversely related to death, no differences in overall survival were seen after those patients were excluded. Burned out HCM was independently associated with an increased risk of death, identifying a subset of patients who may benefit from more aggressive therapies. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Proximate Sources of Population Sex Imbalance in India

PubMed Central

OSTER, EMILY

2009-01-01

There is a population sex imbalance in India. Despite a consensus that this imbalance is due to excess female mortality, the specific source of this excess mortality remains poorly understood. I use microdata on child survival in India to analyze the proximate sources of the sex imbalance. I address two questions: when in life does the sex imbalance arise, and what health or nutritional investments are specifically responsible for its appearance? I present a new methodology that uses microdata on child survival. This methodology explicitly takes into account both the possibility of naturally occurring sex differences in survival and possible differences between investments in their importance for survival. Consistent with existing literature, I find significant excess female mortality in childhood, particularly between the ages of 1 and 5, and argue that the sex imbalance that exists by age 5 is large enough to explain virtually the entire imbalance in the population. Within this age group, sex differences in vaccinations explain between 20% and 30% of excess female mortality, malnutrition explains an additional 20%, and differences in treatment for illness play a smaller role. Together, these investments account for approximately 50% of the sex imbalance in mortality in India. PMID:21305396

Swift Foxes and Ideal Free Distribution: Relative Influence of Vegetation and Rodent Prey Base on Swift Fox Survival, Density, and Home Range Size

DTIC Science & Technology

2012-01-01

of exploiting a wide range of habitats, reported population parameters such as density and survival vary widely indicating variation in habitat quality...more strongly influenced by the “riskiness” of the habitat than by resource availability [8]. Swift fox population parameters in different landscapes...we explored the effects of landscape heterogeneity on population parameters likely to reflect habitat quality, such as population density, home range

Public health surveillance of cancer survival in the United States and worldwide: The contribution of the CONCORD programme.

PubMed

Allemani, Claudia; Coleman, Michel P

2017-12-15

CONCORD is a programme for the global surveillance of cancer survival. In 2015, the second cycle of the program (CONCORD-2) established long-term surveillance of cancer survival worldwide, for the first time, in the largest cancer survival study published to date. CONCORD-2 provided cancer survival trends for 25,676,887 patients diagnosed during the 15-year period between 1995 and 2009 with 1 of 10 common cancers that collectively represented 63% of the global cancer burden in 2009. Herein, the authors summarize the past, describe the present, and outline the future of the CONCORD programme. They discuss the difference between population-based studies and clinical trials, and review the importance of international comparisons of population-based cancer survival. This study will focus on the United States. The authors explain why population-based survival estimates are crucial for driving effective cancer control strategies to reduce the wide and persistent disparities in cancer survival between white and black patients, which are likely to be attributable to differences in access to early diagnosis and optimal treatment. Cancer 2017;123:4977-81. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

A minimum version of log-rank test for testing the existence of cancer cure using relative survival data.

PubMed

Yu, Binbing

2012-01-01

Cancer survival is one of the most important measures to evaluate the effectiveness of treatment and early diagnosis. The ultimate goal of cancer research and patient care is the cure of cancer. As cancer treatments progress, cure becomes a reality for many cancers if patients are diagnosed early and get effective treatment. If a cure does exist for a certain type of cancer, it is useful to estimate the time of cure. For cancers that impose excess risk of mortality, it is informative to understand the difference in survival between cancer patients and the general cancer-free population. In population-based cancer survival studies, relative survival is the standard measure of excess mortality due to cancer. Cure is achieved when the survival of cancer patients is equivalent to that of the general population. This definition of cure is usually called the statistical cure, which is an important measure of burden due to cancer. In this paper, a minimum version of the log-rank test is proposed to test the equivalence of cancer patients' survival using the relative survival data. Performance of the proposed test is evaluated by simulation. Relative survival data from population-based cancer registries in SEER Program are used to examine patients' survival after diagnosis for various major cancer sites. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The relationship between annual survival rate and migration distance in mallards: an examination of the time-allocation hypothesis for the evolution of migration

USGS Publications Warehouse

Hestbeck, J.B.; Nichols, J.D.; Hines, J.E.

1992-01-01

Predictions of the time-allocation hypothesis were tested with several a posteriori analyses of banding data for the mallard (Anas platyrhynchos). The time-allocation hypothesis states that the critical difference between resident and migrant birds is their allocation of time to reproduction on the breeding grounds and survival on the nonbreeding grounds. Residents have higher reproduction and migrants have higher survival. Survival and recovery rates were estimated by standard band-recovery methods for banding reference areas in the central United States and central Canada. A production-rate index was computed for each reference area with data from the U.S. Fish and Wildlife Service May Breeding Population Survey and July Production Survey. An analysis of covariance was used to test for the effects of migration distance and time period (decade) on survival, recovery, and production rates. Differences in migration chronology were tested by comparing direct-recovery distributions for different populations during the fall migration. Differences in winter locations were tested by comparing distributions of direct recoveries reported during December and January. A strong positive relationship was found between survival rate, and migration distance for 3 of the 4 age and sex classes. A weak negative relationship was found between recovery rate and migration distance. No relationship was found between production rate and migration distance. During the fall migration, birds from the northern breeding populations were located north of birds from the southern breeding populations. No pattern could be found in the relative locations of breeding and wintering areas. Although our finding that survival rate increased with migration distance was consistent with the time-allocation hypothesis, our results on migration chronology and location of wintering areas were not consistent with the mechanism underlying the time-allocation hypothesis. Neither this analysis nor other recent studies of life-history characteristics of migratory and resident birds supported the timeallocation hypothesis.

Seasonal productivity in a population of migratory songbirds: why nest data are not enough

USGS Publications Warehouse

Streby, Henry M.; Andersen, David E.

2011-01-01

Population models for many animals are limited by a lack of information regarding juvenile survival. In particular, studies of songbird reproductive output typically terminate with the success or failure of nests, despite the fact that adults spend the rest of the reproductive season rearing dependent fledglings. Unless fledgling survival does not vary, or varies consistently with nest productivity, conclusions about population dynamics based solely on nest data may be misleading. During 2007 and 2008, we monitored nests and used radio telemetry to monitor fledgling survival for a population of Ovenbirds (Seiurus aurocapilla) in a managed-forest landscape in north-central Minnesota, USA. In addition to estimating nest and fledgling survival, we modeled growth for population segments partitioned by proximity to edges of non-nesting cover types (regenerating clearcuts). Nest survival was significantly lower, but fledgling survival was significantly higher, in 2007 than in 2008. Despite higher nest productivity in 2008, seasonal productivity (number of young surviving to independence per breeding female) was higher in 2007. Proximity to clearcut edge did not affect nest productivity. However, fledglings from nests near regenerating sapling-dominated clearcuts (7–20 years since harvest) had higher daily survival (0.992 ± 0.005) than those from nests in interior forest (0.978 ± 0.006), which in turn had higher daily survival than fledglings from nests near shrub-dominated clearcuts (≤6 years since harvest; 0.927 ± 0.030) in 2007, with a similar but statistically non-significant trend in 2008. Our population growth models predicted growth rates that differed by 2–39% (x¯ = 25%) from simpler models in which we replaced our estimates of first-year survival with one-half adult annual survival (an estimate commonly used in songbird population growth models). We conclude that nest productivity is an inadequate measure of songbird seasonal productivity, and that results based exclusively on nest data can yield misleading conclusions about population growth and clearcut edge effects. We suggest that direct estimates of juvenile survival could provide more accurate information for the management and conservation of many animal taxa.

Lambda-Cyhalothrin Resistance in the Lady Beetle Eriopis connexa (Coleoptera: Coccinellidae) Confers Tolerance to Other Pyrethroids.

PubMed

Torres, J B; Rodrigues, A R S; Barros, E M; Santos, D S

2015-02-01

Pyrethroid insecticides are widely recommended to control insect defoliators but lack efficacy against most aphid species. Thus, conserving aphid predators such as the lady beetle Eriopis connexa (Germar) is important to pest management in crop ecosystems that require pyrethroid sprays. In a greenhouse, early fourth-instar larvae and 5-day-old adults from susceptible (S) and resistant (R) E. connexa populations were caged on lambda-cyhalothrin-treated cotton plants, after which survival and egg production (for those caged at adult stage) were assessed. In the laboratory, similar groups were subjected to dried residues and topical treatment with one of eight pyrethroids (alpha-cypermethrin, bifenthrin, deltamethrin, esfenvalerate, fenpropathrin, permethrin, zeta-cypermethrin, and lambda-cyhalothrin), the organophosphate methidathion, or water and wetting agent. After caging on treated cotton terminals, 66% of the R-population larvae survived to adulthood, compared with 2% of those from the S-population. At 12 d after caging at adult stage under the same conditions, 64% of the females from the R-population survived and laid eggs, compared with 100% mortality and no oviposition for the S-females. In trials involving dried insecticide residues, gain in survival based on the survival difference (percentage for R-population minus percentage for S-population) across all tested pyrethroids varied from 3 to 63% for larvae and from 3 to 70% for adults. In trials involving topical sprays of the tested pyrethroids, survival differences ranged from 36 to 96% for larvae and from 21 to 82% for adults. Fenpropathrin and bifenthrin were the least and most toxic, respectively. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Individual covariation in life-history traits: seeing the trees despite the forest

USGS Publications Warehouse

Cam, E.; Link, W.A.; Cooch, E.G.; Monnat, J.-Y.; Danchin, E.

2002-01-01

We investigated the influence of age on survival and breeding rates in a long-lived species Rissa tridactyla using models with individual random effects permitting variation and covariation in fitness components among individuals. Differences in survival or breeding probabilities among individuals are substantial, and there was positive covariation between survival and breeding probability; birds that were more likely to survive were also more likely to breed, given that they survived. The pattern of age-related variation in these rates detected at the individual level differed from that observed at the population level. Our results provided confirmation of what has been suggested by other investigators: within-cohort phenotypic selection can mask senescence. Although this phenomenon has been extensively studied in humans and captive animals, conclusive evidence of the discrepancy between population-level and individual-level patterns of age-related variation in life-history traits is extremely rare in wild animal populations. Evolutionary studies of the influence of age on life-history traits should use approaches differentiating population level from the genuine influence of age: only the latter is relevant to theories of life-history evolution. The development of models permitting access to individual variation in fitness is a promising advance for the study of senescence and evolutionary processes.

Survival and metamorphosis of low-density populations of larval sea lampreys (Petromyzon marinus) in streams following lampricide treatment

USGS Publications Warehouse

Johnson, Nicholas S.; Swink, William D.; Brenden, Travis O.; Slade, Jeffrey W.; Steeves, Todd B.; Fodale, Michael F.; Jones, Michael L.

2014-01-01

Sea lamprey Petromyzon marinus control in the Great Lakes primarily involves application of lampricides to streams where larval production occurs to kill larvae prior to their metamorphosing and entering the lakes as parasites (juveniles). Because lampricides are not 100% effective, larvae that survive treatment maymetamorphose before streams are again treated. Larvae that survive treatment have not beenwidely studied, so their dynamics are notwell understood.Wetagged and released larvae in six Great Lake tributaries following lampricide treatment and estimated vital demographic rates using multistate tag-recovery models. Model-averaged larval survivals ranged from 56.8 to 57.6%. Model-averaged adult recovery rates, which were the product of juvenile survivals and adult capture probabilities, ranged from 6.8 to 9.3%. Using stochastic simulations, we estimated production of juvenile sea lampreys from a hypothetical population of treatment survivors under different growth conditions based on parameter estimates from this research. For fast-growing populations, juvenile production peaked 2 years after treatment. For slow-growing populations, juvenile production was approximately one-third that of fast-growing populations,with production not peaking until 4 years after treatment. Our results suggest that dynamics (i.e., survival, metamorphosis) of residual larval populations are very similar to those of untreated larval populations. Consequently, residual populations do not necessarily warrant special consideration for the purpose of sea lamprey control and can be ranked for treatment along with other populations. Consecutive lampricide treatments, which are under evaluation by the sea lamprey control program, would bemost effective for reducing juvenile production in large, fast-growing populations.

Morphometrics of cellular damage in mice testis receiving X-ray and high-energy particle irradiation

NASA Technical Reports Server (NTRS)

Sapp, Walter J.

1987-01-01

Murine tests were exposed to single, low doses of either X-ray, helium, or argon radiation. Animals were sacrificed seventy-two hours later. Testes were fixed for transmission electron microscopy (TEM) and sectioned at either 60 nm for TEM observation or at 2 micron for counting using routine light microscope methods. Counts of the total population of surviving spermatogonia, including all type A cells, intermediate, and type B cells, were taken from tubule cross sections identified as Stage 6 and Stage 1 according to spermatogonial configuration. The surviving fraction of spermatogonia as compared to control, S/S sub o, was calculated for each dose. For both ions and X-rays, there was a rapid decline in survival at dose levels of .10 to .15 Gy in Stage 6 tubules. This was followed by a more gradual decrease in population. At higher doses, 0.30 Gy for argon and 0.80 Gy for helium and X-rays, the cell survival rates declined rapidly. Pre-leptotene spermatocytes in Stage 1 tubules exhibited a different survival curve indicating the extreme radio-sensitivity of type B spermatogonia. Data verify that the seminiferous tubules are composed of a heterogeneous population of cells with different radio-sensitivities and that these differences are manifested even at very low doses.

The Influence of Individual Variability on Zooplankton Population Dynamics under Different Environmental Conditions

NASA Astrophysics Data System (ADS)

Bi, R.; Liu, H.

2016-02-01

Understanding how biological components respond to environmental changes could be insightful to predict ecosystem trajectories under different climate scenarios. Zooplankton are key components of marine ecosystems and changes in their dynamics could have major impact on ecosystem structure. We developed an individual-based model of a common coastal calanoid copepod Acartia tonsa to examine how environmental factors affect zooplankton population dynamics and explore the role of individual variability in sustaining population under various environmental conditions consisting of temperature, food concentration and salinity. Total abundance, egg production and proportion of survival were used to measure population success. Results suggested population benefits from high level of individual variability under extreme environmental conditions including unfavorable temperature, salinity, as well as low food concentration, and selection on fast-growers becomes stronger with increasing individual variability and increasing environmental stress. Multiple regression analysis showed that temperature, food concentration, salinity and individual variability have significant effects on survival of A. tonsa population. These results suggest that environmental factors have great influence on zooplankton population, and individual variability has important implications for population survivability under unfavorable conditions. Given that marine ecosystems are at risk from drastic environmental changes, understanding how individual variability sustains populations could increase our capability to predict population dynamics in a changing environment.

Egg hatch and survival and development of beet webworm (Lepidoptera: Crambidae) larvae at different combinations of temperature and relative humidity

USDA-ARS?s Scientific Manuscript database

To understand the role that temperature and humidity play in the population dynamics of the beet webworm, Loxostege sticticalis L. (Lepidoptera: Crambidae), egg hatchability, survival of 1st - 5th instars, survival of the complete larval stage, survival curves, and larval development rates were inve...

Predicting long-term graft survival in adult kidney transplant recipients.

PubMed

Pinsky, Brett W; Lentine, Krista L; Ercole, Patrick R; Salvalaggio, Paolo R; Burroughs, Thomas E; Schnitzler, Mark A

2012-07-01

The ability to accurately predict a population's long-term survival has important implications for quantifying the benefits of transplantation. To identify a model that can accurately predict a kidney transplant population's long-term graft survival, we retrospectively studied the United Network of Organ Sharing data from 13,111 kidney-only transplants completed in 1988- 1989. Nineteen-year death-censored graft survival (DCGS) projections were calculated and compared with the population's actual graft survival. The projection curves were created using a two-part estimation model that (1) fits a Kaplan-Meier survival curve immediately after transplant (Part A) and (2) uses truncated observational data to model a survival function for long-term projection (Part B). Projection curves were examined using varying amounts of time to fit both parts of the model. The accuracy of the projection curve was determined by examining whether predicted survival fell within the 95% confidence interval for the 19-year Kaplan-Meier survival, and the sample size needed to detect the difference in projected versus observed survival in a clinical trial. The 19-year DCGS was 40.7% (39.8-41.6%). Excellent predictability (41.3%) can be achieved when Part A is fit for three years and Part B is projected using two additional years of data. Using less than five total years of data tended to overestimate the population's long-term survival, accurate prediction of long-term DCGS is possible, but requires attention to the quantity data used in the projection method.

Survival of patients with hepatocellular carcinoma in the San Joaquin Valley: a comparison with California Cancer Registry data.

PubMed

Atla, Pradeep R; Sheikh, Muhammad Y; Mascarenhas, Ranjan; Choudhury, Jayanta; Mills, Paul

2012-01-01

Variation in the survival of patients with hepatocellular carcinoma (HCC) is related to racial differences, socioeconomic disparities and treatment options among different populations. A retrospective review of the data from medical records of patients diagnosed with HCC were analyzed at an urban tertiary referral teaching hospital and compared to patients in the California Cancer Registry (CCR) - a participant in the Survival Epidemiology and End Results (SEER)program of the National Cancer Institute (NCI). The main outcome measure was overall survival rates. 160 patients with the diagnosis of HCC (M/F=127/33), mean age 59.7±10 years, 32% white, 49% Hispanic, 12% Asian and 6% African American. Multivariate analysis identified tumor size, model for end-stage liver disease (MELD) score, portal vein invasion and treatment offered as the independent predictors of survival (p <0.05). Survival rates across racial groups were not statistically significant. 5.6% received curative treatments (orthotopic liver transplantation, resection, rediofrequency ablation) (median survival 69 months), 34.4% received nonsurgical treatments (trans-arterial chemoembolization, systemic chemotherapy) (median survival 9 months), while 60% received palliative or no treatment (median survival 3 months) (p <0.001). There was decreased survival in our patient population with HCC beyond 2 years. 60% of our study population received only palliative or no treatment suggesting a possible lack of awareness of chronic liver disease as well as access to appropriate surveillance modalities. Ethnic disparities such as Hispanic predominance in this study in contrast to the CCR/SEER database may have been a contributing factor for poorer outcome.

Modeling tradeoffs in avian life history traits and consequences for population growth

USGS Publications Warehouse

Clark, M.E.; Martin, T.E.

2007-01-01

Variation in population dynamics is inherently related to life history characteristics of species, which vary markedly even within phylogenetic groups such as passerine birds. We computed the finite rate of population change (??) from a matrix projection model and from mark-recapture observations for 23 bird species breeding in northern Arizona. We used sensitivity analyses and a simulation model to separate contributions of different life history traits to population growth rate. In particular we focused on contrasting effects of components of reproduction (nest success, clutch size, number of clutches, and juvenile survival) versus adult survival on ??. We explored how changes in nest success or adult survival coupled to costs in other life history parameters affected ?? over a life history gradient provided by our 23 Arizona species, as well as a broader sample of 121 North American passerine species. We further examined these effects for more than 200 passeriform and piciform populations breeding across North America. Model simulations indicate nest success and juvenile survival exert the largest effects on population growth in species with moderate to high reproductive output, whereas adult survival contributed more to population growth in long-lived species. Our simulations suggest that monitoring breeding success in populations across a broad geographic area provides an important index for identifying neotropical migratory populations at risk of serious population declines and a potential method for identifying large-scale mechanisms regulating population dynamics. ?? 2007 Elsevier B.V. All rights reserved.

Postoperative radioactive iodine-131 ablation is not necessary among patients with intermediate-risk differentiated thyroid carcinoma: a population-based study.

PubMed

Zhang, Hong; Cai, Yuechang; Zheng, Li; Zhang, Zhanlei; Jiang, Ningyi

2017-01-01

To assess the effectiveness of radioactive iodine (RAI) ablation among patients with intermediate-risk differentiated thyroid cancer (DTC) following surgery. This population based study obtained information from the Surveillance, Epidemiology, and End Results (SEER) Program Research Data (1973-2013). National Cancer Institute, DCCPS, Surveillance Research Programme, Surveillance Systems Branch, released April 2016, based on the November 2015 submission. A total of 93,530 patients with primary thyroid cancer were identified in the SEER database during the period of 2004-2013 and focused on patients with DTC post-operatively treated or not treated with radioactive iodine (RAI). From these 9,127 patients were selected who had intermediate-risk DTC. A total of 8,601 patients were included in this study. For the overall population, the mean age of the population was 47.3 years and the majority were female (70.5%). Kaplan-Meier analysis found the mean overall survival time (os) for subjects with no radiation therapy which was 112.9 months and 114.9 months for those who received RAI ablation treatment (P<0.001). However, thyroid cancer-specific survival was not significantly different between treatment groups (117.7 vs. 118.0 months, log-rank test P=0.164). Overall survival and thyroid cancer-specific 1 year, 5 years, and 10-years survival rates were ≥89.8% and were similar between both treated groups. Multivariate analysis found age, gender, histologic type, and degree of lymph node metastases to be associated with OS, and age, gender, degree of lymph node metastasis and extra-thyroid tumor spread were independent factors for cancer-specific survival. In DTC patients with intermediate cancer risk multivariate analysis found that RAI was associated with a reduced risk of mortality compared with no radiation therapy (HR=0.710, 95% CI: 0.562-0.897, P=0.004) but no significant difference was seen in cancer-specific survival, either based on whole study population or on tumor size category. In DTC patients with intermediate cancer risk although postoperative RAI ablation following surgery showed a benefit in overall survival, no significant difference was seen in cancer-specific survival, either based on whole study population or on tumor size category.

Coyote removal, understory cover, and survival of white-tailed deer neonates: Coyote Control and Fawn Survival

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kilgo, John C.; Vukovich, Mark; Ray, H. Scott

Predation by coyotes (Canis latrans) on white-tailed deer (Odocoileus virginianus) neonates has led to reduced recruitment in many deer populations in southeastern North America. This low recruitment combined with liberal antlerless deer harvest has resulted in declines in some deer populations, and consequently, increased interest in coyote population control. We investigated whether neonate survival increased after coyote removal, whether coyote predation on neonates was additive to other mortality sources, and whether understory vegetation density affected neonate survival. We monitored neonate survival for 4 years prior to (2006–2009) and 3 years during (2010–2012) intensive coyote removal on 3 32-km 2 unitsmore » on the United States Department of Energy’s Savannah River Site, South Carolina. We removed 474 coyotes (1.63 coyotes/km 2 per unit per year), reducing coyote abundance by 78% from pre-removal levels. The best model (w i = 0.927) describing survival probability among 216 radio-collared neonates included a within-year quadratic time trend variable, date of birth, removal treatment, and a varying removal year effect. Under this model, survival differed between pre-treatment and removal periods and it differed among years during the removal period, being >100% greater than pre-treatment survival (0.228) during the first removal year (0.513), similar to pre-treatment survival during the second removal year (0.202), and intermediate during the third removal year (0.431). Despite an initial increase, the overall effect of coyote removal on neonate survival was modest. Mortality rate attributable to coyote predation was lowest during the first removal year (0.357) when survival was greatest, but the mortality rate from all other causes did not differ between the pretreatment period and any year during removals, indicating that coyote predation acted as an additive source of mortality. Survival probability was not related to vegetation cover, either directly or in interaction with coyote abundance. When the objective is to increase the recruitment of white-tailed deer, we conclude that neither coyote control nor vegetation management appear effective. Reduction of the antlerless harvest may be necessary to meet this objective, but this harvest strategy warrants additional research in Southeastern deer populations.« less

The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves.

PubMed

Stahler, Daniel R; MacNulty, Daniel R; Wayne, Robert K; vonHoldt, Bridgett; Smith, Douglas W

2013-01-01

Reproduction in social organisms is shaped by numerous morphological, behavioural and life-history traits such as body size, cooperative breeding and age of reproduction, respectively. Little is known, however, about the relative influence of these different types of traits on reproduction, particularly in the context of environmental conditions that determine their adaptive value. Here, we use 14 years of data from a long-term study of wolves (Canis lupus) in Yellowstone National Park, USA, to evaluate the relative effects of different traits and ecological factors on the reproductive performance (litter size and survival) of breeding females. At the individual level, litter size and survival improved with body mass and declined with age (c. 4-5 years). Grey-coloured females had more surviving pups than black females, which likely contributed to the maintenance of coat colour polymorphism in this system. The effect of pack size on reproductive performance was nonlinear as litter size peaked at eight wolves and then declined, and litter survival increased rapidly up to three wolves, beyond which it increased more gradually. At the population level, litter size and survival decreased with increasing wolf population size and canine distemper outbreaks. The relative influence of these different-level factors on wolf reproductive success followed individual > group > population. Body mass was the primary determinant of litter size, followed by pack size and population size. Body mass was also the main driver of litter survival, followed by pack size and disease. Reproductive gains because of larger body size and cooperative breeding may mitigate reproductive losses because of negative density dependence and disease. These findings highlight the adaptive value of large body size and sociality in promoting individual fitness in stochastic and competitive environments. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Monitoring survival rates of landbirds at varying spatial scales: An application of the MAPS Program

USGS Publications Warehouse

Rosenberg, D.K.; DeSante, D.F.; Hines, J.E.; Bonney, Rick; Pashley, David N.; Cooper, Robert; Niles, Larry

2000-01-01

Survivorship is a primary demographic parameter affecting population dynamics, and thus trends in species abundance. The Monitoring Avian Productivity and Survivorship (MAPS) program is a cooperative effort designed to monitor landbird demographic parameters. A principle goal of MAPS is to estimate annual survivorship and identify spatial patterns and temporal trends in these rates. We evaluated hypotheses of spatial patterns in survival rates among a collection of neighboring sampling sites, such as within national forests, among biogeographic provinces, and between breeding populations that winter in either Central or South America, and compared these geographic-specific models to a model of a common survival rate among all sampling sites. We used data collected during 1992-1995 from Swainson's Thrush (Cathorus ustulatus) populations in the western region of the United States. We evaluated the ability to detect spatial and temporal patterns of survivorship with simulated data. We found weak evidence of spatial differences in survival rates at the local scale of 'location,' which typically contained 3 mist-netting stations. There was little evidence of differences in survival rates among biogeographic provinces or between populations that winter in either Central or South America. When data were pooled for a regional estimate of survivorship, the percent relative bias due to pooling 'locations' was 12 years of monitoring. Detection of spatial patterns and temporal trends in survival rates from local to regional scales will provide important information for management and future research directed toward conservation of landbirds.

Prognostic discrimination in "good-risk" chronic granulocytic leukemia.

PubMed

Sokal, J E; Cox, E B; Baccarani, M; Tura, S; Gomez, G A; Robertson, J E; Tso, C Y; Braun, T J; Clarkson, B D; Cervantes, F

1984-04-01

The prognostic significance of disease features recorded at the time of diagnosis was examined among 813 patients with Philadelphia chromosome-positive, nonblastic chronic granulocytic leukemia (CGL) collected from six European and American series. The survival pattern for this population was typical of "good-risk" patients, and median survival was 47 mo. There were multiple interrelationships among different disease features, which led to highly significant correlations with survival for some that had no primary prognostic significance, such as hematocrit. Multivariable regression analysis indicated that spleen size and the percentage of circulating blasts were the most important prognostic indicators. These features, and age, behaved as continuous variables with progressively unfavorable import at higher values. The platelet count did not influence survival significantly at values below 700 X 10(9)/liter but was increasingly unfavorable above this level. Basophils plus eosinophils over 15%, more than 5% marrow blasts, and karyotypic abnormalities in addition to the Ph1 were also significant unfavorable signs. The Cox model, generated with four variables representing percent blasts, spleen size, platelet count, and age, provided a useful representation of risk status in this population, with good fit between predicted and observed survival over more than a twofold survival range. A hazard function derived from half of the patient population successfully segregated the remainder into three groups with significantly different survival patterns. We conclude that it should be possible to identify a lower risk group of patients with a 2-yr survival of 90%, subsequent risk averaging somewhat less than 20%/yr and median survival of 5 yr, an intermediate group, and a high-risk group with a 2-yr survival of 65%, followed by a death rate of about 35%/yr and median survival of 2.5 yr.

Climatic conditions produce contrasting influences on demographic traits in a long-distance Arctic migrant.

PubMed

Cleasby, Ian R; Bodey, Thomas W; Vigfusdottir, Freydis; McDonald, Jenni L; McElwaine, Graham; Mackie, Kerry; Colhoun, Kendrew; Bearhop, Stuart

2017-03-01

The manner in which patterns of variation and interactions among demographic rates contribute to population growth rate (λ) is key to understanding how animal populations will respond to changing climatic conditions. Migratory species are likely to be particularly sensitive to climatic conditions as they experience a range of different environments throughout their annual cycle. However, few studies have provided fully integrated demographic analyses of migratory populations in response to changing climatic conditions. Here, we employed integrated population models to demonstrate that the environmental conditions experienced during a short but critical period play a central role in the demography of a long-distance migrant, the light-bellied Brent goose (Branta bernicla hrota). Female survival was positively associated with June North Atlantic Oscillation (NAO) values, whereas male survival was not. In contrast, breeding productivity was negatively associated with June NAO, suggesting a trade-off between female survival and reproductive success. Both adult female and adult male survival showed low temporal variation, whereas there was high temporal variation in recruitment and breeding productivity. In addition, while annual population growth was positively correlated with annual breeding productivity, a sensitivity analysis revealed that population growth was most sensitive to changes in adult survival. Our results demonstrate that the environmental conditions experienced during a relatively short-time window at the start of the breeding season play a critical role in shaping the demography of a long-distant Arctic migrant. Crucially, different demographic rates responded in opposing directions to climatic variation, emphasising the need for integrated analysis of multiple demographic traits when understanding population dynamics. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

Inter-class competition in stage-structured populations: effects of adult density on life-history traits of adult and juvenile common lizards.

PubMed

San-Jose, Luis M; Peñalver-Alcázar, Miguel; Huyghe, Katleen; Breedveld, Merel C; Fitze, Patrick S

2016-12-01

Ecological and evolutionary processes in natural populations are largely influenced by the population's stage-structure. Commonly, different classes have different competitive abilities, e.g., due to differences in body size, suggesting that inter-class competition may be important and largely asymmetric. However, experimental evidence states that inter-class competition, which is important, is rare and restricted to marine fish. Here, we manipulated the adult density in six semi-natural populations of the European common lizard, Zootoca vivipara, while holding juvenile density constant. Adult density affected juveniles, but not adults, in line with inter-class competition. High adult density led to lower juvenile survival and growth before hibernation. In contrast, juvenile survival after hibernation was higher in populations with high adult density, pointing to relaxed inter-class competition. As a result, annual survival was not affected by adult density, showing that differences in pre- and post-hibernation survival balanced each other out. The intensity of inter-class competition affected reproduction, performance, and body size in juveniles. Path analyses unravelled direct treatment effects on early growth (pre-hibernation) and no direct treatment effects on the parameters measured after hibernation. This points to allometry of treatment-induced differences in early growth, and it suggests that inter-class competition mainly affects the early growth of the competitively inferior class and thereby their future performance and reproduction. These results are in contrast with previous findings and, together with results in marine fish, suggest that the strength and direction of density dependence may depend on the degree of inter-class competition, and thus on the availability of resources used by the competing classes.

Older fathers' children have lower evolutionary fitness across four centuries and in four populations

PubMed Central

Willführ, Kai P.; Frans, Emma M.; Verweij, Karin J. H.; Bürkner, Paul-Christian; Myrskylä, Mikko; Voland, Eckart; Zietsch, Brendan P.; Penke, Lars

2017-01-01

Higher paternal age at offspring conception increases de novo genetic mutations. Based on evolutionary genetic theory we predicted older fathers' children, all else equal, would be less likely to survive and reproduce, i.e. have lower fitness. In sibling control studies, we find support for negative paternal age effects on offspring survival and reproductive success across four large populations with an aggregate N > 1.4 million. Three populations were pre-industrial (1670–1850) Western populations and showed negative paternal age effects on infant survival and offspring reproductive success. In twentieth-century Sweden, we found minuscule paternal age effects on survival, but found negative effects on reproductive success. Effects survived tests for key competing explanations, including maternal age and parental loss, but effects varied widely over different plausible model specifications and some competing explanations such as diminishing paternal investment and epigenetic mutations could not be tested. We can use our findings to aid in predicting the effect increasingly older parents in today's society will have on their children's survival and reproductive success. To the extent that we succeeded in isolating a mutation-driven effect of paternal age, our results can be understood to show that de novo mutations reduce offspring fitness across populations and time periods. PMID:28904145

Wild turkey poult survival in southcentral Iowa

USGS Publications Warehouse

Hubbard, M.W.; Garner, D.L.; Klaas, E.E.

1999-01-01

Poult survival is key to understanding annual change in wild turkey (Meleagris gallopavo) populations. Survival of eastern wild turkey poults (M. g. silvestris) 0-4 weeks posthatch was studied in southcentral Iowa during 1994-97. Survival estimates of poults were calculated based on biweekly flush counts and daily locations acquired via radiotelemetry. Poult survival averaged 0.52 ?? 0.14% (?? ?? SE) for telemetry counts and 0.40 ?? 0.15 for flush counts. No within-year or across-year differences were detected between estimation techniques. More than 72% (n = 32) of documented poult mortality occurred ???14 days posthatch, and mammalian predation accounted for 92.9% of documented mortality. If mortality agents are not of concern, we suggest biologists conduct 4-week flush counts to obtain poult survival estimates for use in population models and development of harvest recommendations.

The demographic consequences of mutualism: ants increase host-plant fruit production but not population growth.

PubMed

Ford, Kevin R; Ness, Joshua H; Bronstein, Judith L; Morris, William F

2015-10-01

The impact of mutualists on a partner's demography depends on how they affect the partner's multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and simulations of long-term population dynamics to quantify the demographic impact of a guild of ant species on the plant Ferocactus wislizeni. The ants feed at the plant's extrafloral nectaries and attack herbivores attempting to consume reproductive organs. Ant-guarded plants produced significantly more fruit, but ants had no significant effect on individual growth or survival. After integrating ant effects across these vital rates, we found that projected population growth was not significantly different between unguarded and ant-guarded plants because population growth was only weakly influenced by differences in fruit production (though strongly influenced by differences in individual growth and survival). However, simulations showed that ants could positively affect long-term plant population dynamics through services provided during rare but important events (herbivore outbreaks that reduce survival or years of high seedling recruitment associated with abundant precipitation). Thus, in this seemingly clear example of mutualism, the interaction may actually yield no clear benefit to plant population growth, or if it does, may only do so through the actions of the ants during rare events. These insights demonstrate the value of taking a demographic approach to studying the consequences of mutualism.

Temperature-Dependent Development and Survival of Brazilian Populations of the Mediterranean Fruit Fly, Ceratitis capitata, from Tropical, Subtropical and Temperate Regions

PubMed Central

Ricalde, Marcelo P.; Nava, Dori E.; Loeck, Alci E.; Donatti, Michele G.

2012-01-01

The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the principal exotic pests affecting Brazilian production in the northeastern and southeastern regions of Brazil. In the south, it is has potential as a serious threat to temperate-climate fruit farms, since it is already found in urban and suburban communities in this region. We studied the biological characteristics of C. capitata populations from Pelotas-RS (temperate climate), Petrolina-PE (tropical), and Campinas-SP (subtropical). Ceratitis capitata biology was studied under controlled temperature (15, 20, 25, 30, and 35 ± 1 °C), 70 ± 10% RH, and 14:10 L:D photoperiod. The duration and survival rate of the egg, larval, and pupal stages were evaluated and the thermal requirements of these three populations were determined. The duration and survival of these developmental stages varied with temperature, with similar values for the three populations, except for some variation in the egg phase. Egg to adult developmental time for all three populations was inversely proportional to temperature; from 15 to 30 °C developmental time varied from 71.2 to 17.1, 70.2 to 17.1, and 68.5 to 16.9 days, respectively. Survival during development was affected at 15 to 30 °C, and differed significantly from survival at 20 to 25 °C. At 35 °C, immature stages did not develop. The basal temperature and degree-day requirement were similar for all immature stages except for the egg stage. The basal temperatures and thermal constants were 9.30 and 350, 8.47 and 341, and 9.60 °C and 328 degree-days for the Pelotas, Petrolina, and Campinas populations, respectively. Results suggested that survival and thermal requirements are similar for these tropical, subtropical, and temperate populations of C. capitata, and demonstrate the species' capacity to adapt to different climate conditions. PMID:22963468

Survival of the biological control agent Candida sake CPA-1 on grapes under the influence of abiotic factors.

PubMed

Calvo-Garrido, C; Viñas, I; Usall, J; Rodríguez-Romera, M; Ramos, M C; Teixidó, N

2014-09-01

As reliability of preharvest applications of biological control agents (BCAs) to control fruit pathogens is highly dependent on the survival of the selected organism, this study aimed to describe the population dynamics of the yeast-BCA Candida sake (Saito & Ota) CPA-1 on grape berries under the effect of abiotic factors such as temperature, relative humidity, sunlight and rainfall. Candida sake (5 × 10(7) CFU ml(-1)), combined with different concentrations of the food additive Fungicover(®), was applied on grape berry clusters. Treated clusters were then exposed to abiotic factors in field or laboratory conditions, recovering populations to describe C. sake population dynamics. The addition of Fungicover significantly increased C. sake multiplication under optimal growth conditions and improved survival under fluctuating abiotic factors. After field applications, significant differences in populations on grape bunches exposed or covered by fine foliage were detected. Simulated rainfall washed off C. sake populations by 0·6-0·9 log units after 20 mm of rain volume. Allowing populations to establish for 24 h or more, prior to a rain event, persistence on grape berries significantly increased and the effect of rain intensity was not observable. Candida sake demonstrated high survival ability under unfavourable environmental conditions and persistence under intense rain. The study evidenced the importance of the first period just after application for C. sake survival on grape tissues and also the protective effect of the additive Fungicover. This research provides new information on the survival of C. sake under field conditions and its practical implications for recommending timing of spray with this antagonist. Our results could be useful for other yeast antagonists applied before harvest. This work, for the first time, defines population dynamics of a yeast BCA using simulated rainfall. © 2014 The Society for Applied Microbiology.

Parental identity influences progeny responses to incubation thermal stress in sockeye salmon Onchorhynchus nerka.

PubMed

Burt, J M; Hinch, S G; Patterson, D A

2012-02-01

The influence of individual parentage on progeny responses to early developmental temperature stress was examined in a cross-fertilization experiment using sockeye salmon Oncorhynchus nerka. Differences in survival, hatch timing and size were examined among five paternally linked and five maternally linked offspring families (Weaver Creek population, British Columbia, Canada) incubated at 12, 14 and 16° C from just after fertilization to hatch. Mean embryonic survival was significantly lower at 14 and 16° C; however, offspring families had substantially different survival responses across the thermal gradient (crossing reaction norms). Within temperature treatments, substantial variation in embryonic survival, alevin mass, time-to-hatch and hatch duration were attributable to family identity; however, most traits were governed by significant temperature-family interactions. For embryonic survival, large differences between families at 16° C were due to both female and male spawner influence, whereas inter-family differences were obscured at 14° C (high intra-family variation), and minimal at 12° C (only maternal influence detected). Despite post-hatch rearing under a common cool thermal regime, persistent effects of both temperature and parentage were detected in alevin and 3 week-old fry. Collectively, these findings highlight the crucial role that parental influences on offspring may have in shaping future selection within salmonid populations exposed to elevated thermal regimes. An increased understanding of parental and temperature influences and their persistence in early development will be essential to developing a more comprehensive view of population spawning success and determining the adaptive capacity of O. nerka populations in the face of environmental change. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Survival Comparison of Patients With Cystic Fibrosis in Canada and the United States: A Population-Based Cohort Study.

PubMed

Stephenson, Anne L; Sykes, Jenna; Stanojevic, Sanja; Quon, Bradley S; Marshall, Bruce C; Petren, Kristofer; Ostrenga, Josh; Fink, Aliza K; Elbert, Alexander; Goss, Christopher H

2017-04-18

In 2011, the median age of survival of patients with cystic fibrosis reported in the United States was 36.8 years, compared with 48.5 years in Canada. Direct comparison of survival estimates between national registries is challenging because of inherent differences in methodologies used, data processing techniques, and ascertainment bias. To use a standardized approach to calculate cystic fibrosis survival estimates and to explore differences between Canada and the United States. Population-based study. 42 Canadian cystic fibrosis clinics and 110 U.S. cystic fibrosis care centers. Patients followed in the Canadian Cystic Fibrosis Registry (CCFR) and U.S. Cystic Fibrosis Foundation Patient Registry (CFFPR) between 1990 and 2013. Cox proportional hazards models were used to compare survival between patients followed in the CCFR (n = 5941) and those in the CFFPR (n = 45 448). Multivariable models were used to adjust for factors known to be associated with survival. Median age of survival in patients with cystic fibrosis increased in both countries between 1990 and 2013; however, in 1995 and 2005, survival in Canada increased at a faster rate than in the United States (P < 0.001). On the basis of contemporary data from 2009 to 2013, the median age of survival in Canada was 10 years greater than in the United States (50.9 vs. 40.6 years, respectively). The adjusted risk for death was 34% lower in Canada than the United States (hazard ratio, 0.66 [95% CI, 0.54 to 0.81]). A greater proportion of patients in Canada received transplants (10.3% vs. 6.5%, respectively [standardized difference, 13.7]). Differences in survival between U.S. and Canadian patients varied according to U.S. patients' insurance status. Ascertainment bias due to missing data or nonrandom loss to follow-up might affect the results. Differences in cystic fibrosis survival between Canada and the United States persisted after adjustment for risk factors associated with survival, except for private-insurance status among U.S. patients. Differential access to transplantation, increased posttransplant survival, and differences in health care systems may, in part, explain the Canadian survival advantage. U.S. Cystic Fibrosis Foundation.

Survival differences and the effect of environmental instability on breeding dispersal in an Adélie penguin meta-population

PubMed Central

Dugger, Katie M.; Ainley, David G.; Lyver, Phil O'B.; Barton, Kerry; Ballard, Grant

2010-01-01

High survival and breeding philopatry was previously confirmed for the Adélie penguin (Pygoscelis adeliae) during a period of stable environmental conditions. However, movements of breeding adults as a result of an unplanned natural experiment within a four-colony meta-population provided interesting insights into this species’ population dynamics. We used multistate mark-recapture models to investigate apparent survival and dispersal of breeding birds in the southwestern Ross Sea during 12 breeding seasons (1996–2007). The natural experiment was facilitated by the temporary grounding of two immense icebergs that (i) erected a veritable fence separating colonies and altering migration routes and (ii) added additional stress by trapping extensive sea ice in the region during 5 of 12 y. Colony size varied by orders of magnitude, allowing investigation of apparent survival and dispersal rates in relation to both environmental conditions and colony size within this meta-population. Apparent survival was lowest for the smallest colony (4,000 pairs) and similar for the medium (45,000 pairs) and large colonies (155,000 pairs), despite increased foraging effort expended by breeders at the largest colony. Dispersal of breeding birds was low (<1%), except during years of difficult environmental conditions when movements increased, especially away from the smallest colony (3.5%). Decreased apparent survival at the smallest colony could reflect differences in migration chronology and winter habitat use compared with the other colonies, or it may reflect increased permanent emigration to colonies outside this meta-population. Contrary to current thought, breeding penguins are not always philopatric. Rather, stressful conditions can significantly increase dispersal rates. PMID:20566874

Survival models for harvest management of mourning dove populations

USGS Publications Warehouse

Otis, D.L.

2002-01-01

Quantitative models of the relationship between annual survival and harvest rate of migratory game-bird populations are essential to science-based harvest management strategies. I used the best available band-recovery and harvest data for mourning doves (Zenaida macroura) to build a set of models based on different assumptions about compensatory harvest mortality. Although these models suffer from lack of contemporary data, they can be used in development of an initial set of population models that synthesize existing demographic data on a management-unit scale, and serve as a tool for prioritization of population demographic information needs. Credible harvest management plans for mourning dove populations will require a long-term commitment to population monitoring and iterative population analysis.

Does framing of cancer survival affect perceived value of care? A willingness-to-pay survey of US residents.

PubMed

Lin, Pei-Jung; Concannon, Thomas W; Greenberg, Dan; Cohen, Joshua T; Rossi, Gregory; Hille, Jeffrey; Auerbach, Hannah R; Fang, Chi-Hui; Nadler, Eric S; Neumann, Peter J

2013-08-01

To investigate the relationship between the framing of survival gains and the perceived value of cancer care. Through a population-based survey of 2040 US adults, respondents were randomized to one of the two sets of hypothetical scenarios, each of which described the survival benefit for a new treatment as either an increase in median survival time (median survival), or an increase in the probability of survival for a given length of time (landmark survival). Each respondent was presented with two randomly selected scenarios with different prognosis and survival improvements, and asked about their willingness to pay (WTP) for the new treatments. Predicted WTP increased with survival benefits and respondents' income, regardless of how survival benefits were described. Framing therapeutic benefits as improvements in landmark rather than median time survival increased the proportion of the population willing to pay for that gain by 11-35%, and the mean WTP amount by 42-72% in the scenarios we compared. How survival benefits are described may influence the value people place on cancer care.

Survival of patients with hepatocellular carcinoma in the San Joaquin Valley: a comparison with California Cancer Registry data

PubMed Central

Atla, Pradeep R.; Sheikh, Muhammad Y.; Mascarenhas, Ranjan; Choudhury, Jayanta; Mills, Paul

2012-01-01

Background Variation in the survival of patients with hepatocellular carcinoma (HCC) is related to racial differences, socioeconomic disparities and treatment options among different populations. Methods A retrospective review of the data from medical records of patients diagnosed with HCC were analyzed at an urban tertiary referral teaching hospital and compared to patients in the California Cancer Registry (CCR) – a participant in the Survival Epidemiology and End Results (SEER)program of the National Cancer Institute (NCI). The main outcome measure was overall survival rates. Results 160 patients with the diagnosis of HCC (M/F=127/33), mean age 59.7±10 years, 32% white, 49% Hispanic, 12% Asian and 6% African American. Multivariate analysis identified tumor size, model for end-stage liver disease (MELD) score, portal vein invasion and treatment offered as the independent predictors of survival (p <0.05). Survival rates across racial groups were not statistically significant. 5.6% received curative treatments (orthotopic liver transplantation, resection, rediofrequency ablation) (median survival 69 months), 34.4% received nonsurgical treatments (trans-arterial chemoembolization, systemic chemotherapy) (median survival 9 months), while 60% received palliative or no treatment (median survival 3 months) (p <0.001). Conclusion There was decreased survival in our patient population with HCC beyond 2 years. 60% of our study population received only palliative or no treatment suggesting a possible lack of awareness of chronic liver disease as well as access to appropriate surveillance modalities. Ethnic disparities such as Hispanic predominance in this study in contrast to the CCR/SEER database may have been a contributing factor for poorer outcome. PMID:24714222

Environmental factors affecting survival of immature Ixodes scapularis and implications for geographical distribution of lyme disease: The climate/behavior hypothesis

USGS Publications Warehouse

Ginsberg, Howard; Albert, Marisa; Acevedo, Lixis; Dyer, Megan C.; Arsnoe, Isis M.; Tsao, Jean I.; Mather, Thomas N.; LeBrun, Roger A.

2017-01-01

Recent reports suggest that host-seeking nymphs in southern populations of Ixodes scapularis remain below the leaf litter surface, while northern nymphs seek hosts on leaves and twigs above the litter surface. This behavioral difference potentially results in decreased tick contact with humans in the south, and fewer cases of Lyme disease. We studied whether north-south differences in tick survival patterns might contribute to this phenomenon. Four month old larvae resulting from a cross between Wisconsin males and South Carolina females died faster under southern than under northern conditions in the lab, as has previously been reported for ticks from both northern and southern populations. However, newly-emerged larvae from Rhode Island parents did not differ consistently in mortality under northern and southern conditions, possibly because of their younger age. Survival is lower, and so the north-south survival difference might be greater in older ticks. Larval survival was positively related to larval size (as measured by scutal area), while survival was positively related to larval fat content in some, but not all, trials. The difference in larval survival under northern vs. southern conditions might simply result from faster metabolism under warmer southern conditions leading to shorter life spans. However, ticks consistently died faster under southern than under northern conditions in the laboratory when relative humidity was low (75%), but not under moderate (85%) or high (95%) RH. Therefore, mortality due to desiccation stress is greater under southern than under northern conditions. We hypothesize that mortality resulting from the greater desiccation stress under southern conditions acts as a selective pressure resulting in the evolution of host-seeking behavior in which immatures remain below the leaf litter surface in southern I. scapularis populations, so as to avoid the desiccating conditions at the surface. If this hypothesis is correct, it has implications for the effect of climate change on the future distribution of Lyme disease.

The survival benefit of dual dispatch of EMS and fire-fighters in out-of-hospital cardiac arrest may differ depending on population density--a prospective cohort study.

PubMed

Nordberg, Per; Jonsson, Martin; Forsberg, Sune; Ringh, Mattias; Fredman, David; Riva, Gabriel; Hasselqvist-Ax, Ingela; Hollenberg, Jacob

2015-05-01

Outcome after out-of-hospital cardiac arrest (OHCA) varies between contexts. Dual dispatching of fire-fighters or police in addition to emergency medical services (EMS) has the potential to increase survival, but the effect in urban vs. rural areas is unknown. The aim of this study was to determine the effects of dual dispatching on response times and outcome in regions with different population density. The study design was a prospective cohort study of EMS-treated OHCAs from 2004 (historical controls, only EMS dispatch) and 2006-2009 (intervention, dual dispatch of EMS and fire-fighters), with data on exact geographical coordinates. Patients were divided into four subgroups depending on population density: rural (<250 persons/km2), suburban (250-2999/km2), urban (3000-5999/km2) and downtown (≥6000/km2). Totally, 2513 OHCAs were included (historical controls, n=571 and intervention, n=1942). Median time to arrival of first unit shortened significantly in all subgroups, ranging from 0.8 to 3.2 min, with the main time gain in the rural area. There were significant differences in 30-day survival between the historical controls vs. the intervention group in the suburban population (3.1% vs. 7.0%, p=0.02) and in downtown (4.1 vs. 14.6, p=0.04). In the urban population the difference was 2.7 vs. 6.9% (p=0.06) and in the rural population (4.7 vs. 5.3, p=0.82). Dual dispatch of fire-fighters and EMS in OHCA significantly reduced response times in all studied regions. The 30-day survival increased significantly in the downtown and suburban populations, while a limited impact was seen in the rural areas. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Investigating Rates of Hunting and Survival in Declining European Lapwing Populations

PubMed Central

2016-01-01

Understanding effects of harvest on population dynamics is of major interest, especially for declining species. European lapwing Vanellus vanellus populations increased from the 1960s until the 1980s and declined strongly thereafter. About 400,000 lapwings are harvested annually and it is thus of high conservation relevance to assess whether hunting was a main cause for the observed changes in lapwing population trends. We developed a multi-event cause-specific mortality model which we applied to a long-term ring-recovery data set (1960–2010) of > 360,000 records to estimate survival and cause-specific mortalities. We found no temporal change in survival over the last 50 years for first-year (FY) and older birds (after first-year; AFY) originating from different ringing areas. Mean survival was high, around 0.60 and 0.80 for FY and AFY individuals, respectively. The proportion of total mortality due to hunting was <0.10 over the study period and the estimated proportion of harvested individuals (kill rate) was <0.05 in each year. Our result of constant survival indicates that demographic processes other than survival were responsible for the pronounced change in lapwing population trends in the 1980s. Our findings lend support to the hypothesis that hunting was not a significant contributor to the large-scale decline of lapwing populations. To halt the ongoing decline of European lapwing populations management should focus on life history stages other than survival (e.g. productivity). Further analyses are required to investigate the contribution of other demographic rates to the decline of lapwings and to identify the most efficient conservation actions. PMID:27685660

Interactions between Soil Habitat and Geographic Range Location Affect Plant Fitness

PubMed Central

Stanton-Geddes, John; Shaw, Ruth G.; Tiffin, Peter

2012-01-01

Populations are often found on different habitats at different geographic locations. This habitat shift may be due to biased dispersal, physiological tolerances or biotic interactions. To explore how fitness of the native plant Chamaecrista fasciculata depends on habitat within, at and beyond its range edge, we planted seeds from five populations in two soil substrates at these geographic locations. We found that with reduced competition, lifetime fitness was always greater or equivalent in one habitat type, loam soils, though early-season survival was greater on sand soils. At the range edge, natural populations are typically found on sand soil habitats, which are also less competitive environments. Early-season survival and fitness differed among source populations, and when transplanted beyond the range edge, range edge populations had greater fitness than interior populations. Our results indicate that even when the optimal soil substrate for a species does not change with geographic range location, the realized niche of a species may be restricted to sub-optimal habitats at the range edge because of the combined effects of differences in abiotic and biotic effects (e.g. competitors) between substrates. PMID:22615745

Winter survival of lesser scaup in east-central Florida

USGS Publications Warehouse

Herring, G.; Collazo, J.A.

2004-01-01

The North American continental population of lesser scaup (Aythya affinis) has been declining since the mid-1980s. Seasonal survival estimates may provide insights about the ecological basis for this decline, but such data are not available. We estimated post-harvest winter survival of lesser scaup in east-central Florida, USA, where 62% of the Atlantic Flyway population winters. The Kaplan-Meier survival estimate from 11 January to 14 March 2002 was 0.95 ?? 0.04 (SE) for females and 0.90 ?? 0.09 for males. These estimates were not different (P = 0.64), and pooled survival was 0.93 ?? 0.04. Temporary emigration (movement out of and return to the study area) was exhibited by 25% of the birds during survey periods, but absences were short and were believed to have had little effect on precision of survival estimates. Our findings suggested that natural mortality at Merritt Island National Wildlife Refuge (MINWR) and surrounding estuarine areas was relatively low. Our results also indicate that habitat quality in this portion of east-central Florida was sufficient to meet overwintering requirements and likely contributed to the reported survival rates. Estimating survival during other stages of the annual cycle, as well as an overall winter estimate reflecting harvest mortality, is necessary to determine whether low survival rates are responsible for continental population declines.

Poor horse traders: large mammals trade survival for reproduction during the process of feralization

PubMed Central

Grange, Sophie; Duncan, Patrick; Gaillard, Jean-Michel

2009-01-01

We investigated density dependence on the demographic parameters of a population of Camargue horses (Equus caballus), individually monitored and unmanaged for eight years. We also analysed the contributions of individual demographic parameters to changes in the population growth rates. The decrease in resources caused a loss of body condition. Adult male survival was not affected, but the survival of foals and adult females decreased with increasing density. Prime-aged females maintained high reproductive performance at high density, and their survival decreased. The higher survival of adult males compared with females at high density presumably results from higher investment in reproduction by mares. The high fecundity in prime-aged females, even when at high density, may result from artificial selection for high reproductive performance, which is known to have occurred in all the major domestic ungulates. Other studies suggest that feral ungulates including cattle and sheep, as these horses, respond differently from wild ungulates to increases in density, by trading adult survival for reproduction. As a consequence, populations of feral animals should oscillate more strongly than their wild counterparts, since they should be both more invasive (as they breed faster), and more sensitive to harsh environmental conditions (as the population growth rate of long-lived species is consistently more sensitive to a given proportional change in adult survival than to the same change in any other vital rate). If this principle proves to be general, it has important implications for management of populations of feral ungulates. PMID:19324787

Estimates of annual survival probabilities for adult Florida manatees (Trichechus manatus latirostris)

USGS Publications Warehouse

Langtimm, C.A.; O'Shea, T.J.; Pradel, R.; Beck, C.A.

1998-01-01

The population dynamics of large, long-lived mammals are particularly sensitive to changes in adult survival. Understanding factors affecting survival patterns is therefore critical for developing and testing theories of population dynamics and for developing management strategies aimed at preventing declines or extinction in such taxa. Few studies have used modern analytical approaches for analyzing variation and testing hypotheses about survival probabilities in large mammals. This paper reports a detailed analysis of annual adult survival in the Florida manatee (Trichechus manatus latirostris), an endangered marine mammal, based on a mark-recapture approach. Natural and boat-inflicted scars distinctively 'marked' individual manatees that were cataloged in a computer-based photographic system. Photo-documented resightings provided 'recaptures.' Using open population models, annual adult-survival probabilities were estimated for manatees observed in winter in three areas of Florida: Blue Spring, Crystal River, and the Atlantic coast. After using goodness-of-fit tests in Program RELEASE to search for violations of the assumptions of mark-recapture analysis, survival and sighting probabilities were modeled under several different biological hypotheses with Program SURGE. Estimates of mean annual probability of sighting varied from 0.948 for Blue Spring to 0.737 for Crystal River and 0.507 for the Atlantic coast. At Crystal River and Blue Spring, annual survival probabilities were best estimated as constant over the study period at 0.96 (95% CI = 0.951-0.975 and 0.900-0.985, respectively). On the Atlantic coast, where manatees are impacted more by human activities, annual survival probabilities had a significantly lower mean estimate of 0.91 (95% CI = 0.887-0.926) and varied unpredictably over the study period. For each study area, survival did not differ between sexes and was independent of relative adult age. The high constant adult-survival probabilities estimated for manatees in the Blue Spring and Crystal River areas were consistent with current mammalian life history theory and other empirical data available for large, long-lived mammals. Adult survival probabilities in these areas appeared high enough to maintain growing populations if other traits such as reproductive rates and juvenile survival were also sufficiently high lower and variable survival rates on the Atlantic coast are cause for concern.

Evaluation of Delisting Criteria and Rebuilding Schedules for Snake River Spring/Summer Chinook, Fall Chinook and Sockeye Salmon : Recovery Issues for Threatened and Endangered Snake River Salmon : Technical Report 10 of 11.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cramer, Steven P.; Neeley, Doug

1993-06-01

We develop a framework for distinguishing healthy and threatened populations, and we analyze specific criteria by which these terms can be measured for threatened populations of salmon in the Snake River. We review reports and analyze existing data on listed populations of salmon in the Snake River to establish a framework for two stages of the recovery process: (1) defining de-listing criteria, and (2) estimating the percentage increase in survival that will be necessary for recovery of the population within specified time frames, given the de-listing criteria that must be achieved. We develop and apply a simplified population model tomore » estimate the percentage improvement in survival that will be necessary to achieve different rates of recovery. We considered five main concepts identifying de-listing criteria: (1) minimum population size, (2) rates of population change, (3) number of population subunits, (4) survival rates, and (5) driving variables. In considering minimum population size, we conclude that high variation in survival rates poses a substantially greater probability of causing extinction than does loss of genetic variation. Distinct population subunits exist and affect both the genetic variability of the population and the dynamics of population decline and growth. We distinguish between two types of population subunits, (1) genetic and (2) geographic, and we give examples of their effects on population recovery.« less

Linking vital rates to invasiveness of a perennial herb.

PubMed

Ramula, Satu

2014-04-01

Invaders generally show better individual performance than non-invaders and, therefore, vital rates (survival, growth, fecundity) could potentially be used to predict species invasiveness outside their native range. Comparative studies have usually correlated vital rates with the invasiveness status of species, while few studies have investigated them in relation to population growth rate. Here, I examined the influence of five vital rates (plant establishment, survival, growth, flowering probability, seed production) and their variability (across geographic regions, habitat types, population sizes and population densities) on population growth rate (λ) using data from 37 populations of an invasive, iteroparous herb (Lupinus polyphyllus) in a part of its invaded range in Finland. Variation in vital rates was often related to habitat type and population density. The performance of the populations varied from declining to rapidly increasing independently of habitat type, population size or population density, but differed between regions. The population growth rate increased linearly with plant establishment, and with the survival and growth of vegetative individuals, while the survival of flowering individuals and annual seed production were not related to λ. The vital rates responsible for rapid population growth varied among populations. These findings highlight the importance of both regional and local conditions to plant population dynamics, demonstrating that individual vital rates do not necessarily correlate with λ. Therefore, to understand the role of individual vital rates in a species ability to invade, it is necessary to quantify their effect on population growth rate.

Survival, cause-specific mortality, and harvesting of male black-tailed deer in washington

USGS Publications Warehouse

Bender, L.C.; Schirato, G.A.; Spencer, R.D.; McAllister, K.R.; Murphie, B.L.

2004-01-01

We determined survival rates, causes of mortality, and documented impacts of harvest on ???1.5-year-old male (hereafter, male) Columbian black-tailed deer (Odocoileus hemionus columbianus) in 2 Washington, USA, game management units (GMUs; Skookumchuck and Snoqualmie) characterized by different hunting-season structures. We monitored 66 males (n = 28 and 38 annually) in Skookumchuck and 58 males (n = 26 and 32 annually) in Snoqualmie, September 1999-September 2001. Annual survival rates were 0.498 (SE = 0.066) in Skookumchuck and 0.519 (SE = 0.067) in Snoqualmie. Survival rates derived from population age structure did not differ from rates derived from radiotelemetry. Harvest was the primary mortality factor for each population, accounting for 67% (SE = 7; Skookumchuck) to 44% (SE = 9; Snoqualmie) of total annual mortality. Annual harvest-specific mortality rates were 0.317 (SE = 0.032) in Skookumchuck and 0.211 (SE = 0.021) in Snoqualmie, likely due to longer hunting seasons and greater hunter effort in Skookumchuck. Following the elimination of a late buck season centered on the rut in Snoqualmie, male harvest declined 56% and annual survival increased 60%, indicating that male harvest was largely additive to other mortality. Our results indicated that harvest was the primary influence on male black-tailed deer populations in Washington, was additive, and that the effect of harvest varied with hunting-season structure and hunter effort. Managers should not assume that harvesting removes a constant proportion of the male population annually, and management models that assume compensatory mortality in adult harvest may result in over-harvest of male populations.

Winter distribution, movements, and annual survival of radiomarked Vancouver Canada geese in southeast Alaska

USGS Publications Warehouse

Hupp, Jerry W.; Hodges, John I.; Conant, Bruce P.; Meixell, Brandt W.; Groves, Debbie J.

2010-01-01

Management of Pacific Flyway Canada geese (Branta canadensis) requires information on winter distribution of different populations. Recoveries of tarsus bands from Vancouver Canada geese (B. canadensis fulva) marked in southeast Alaska, USA, ≥4 decades ago suggested that ≥83% of the population was non-migratory and that annual adult survival was high (Ŝ = 0.836). However, recovery distribution of tarsus bands was potentially biased due to geographic differences in harvest intensity in the Pacific Flyway. Also, winter distribution of Vancouver Canada geese could have shifted since the 1960s, as has occurred for some other populations of Canada geese. Because winter distribution and annual survival of this population had not recently been evaluated, we surgically implanted very high frequency radiotransmitters in 166 adult female Canada geese in southeast Alaska. We captured Vancouver Canada geese during molt at 2 sites where adults with goslings were present (breeding areas) and 2 sites where we observed nonbreeding birds only. During winter radiotracking flights in southeast Alaska, we detected 98% of 85 females marked at breeding areas and 83% of 70 females marked at nonbreeding sites, excluding 11 females that died prior to the onset of winter radiotracking. We detected no radiomarked females in coastal British Columbia, or western Washington and Oregon, USA. Most (70%) females moved ≤30 km between November and March. Our model-averaged estimate of annual survival (Ŝ = 0.844, SE = 0.050) was similar to the estimate of annual survival of geese marked from 1956 to 1960. Likely <2% of Vancouver Canada geese that nest in southeast Alaska migrate to winter areas in Oregon or Washington where they could intermix with Canada geese from other populations in the Pacific Flyway. Because annual survival of adult Vancouver Canada geese was high and showed evidence of long-term consistency, managers should examine how reproductive success and recruitment may affect the population.

Home parenteral nutrition for advanced cancer patients: Contributes to survival?

PubMed

Theilla, Miriam; Cohen, Johnathan; Kagan, Ilia; Attal-Singer, Joelle; Lev, Shaul; Singer, Pierre

2017-03-24

Patients with advanced cancer often suffer from severe malnutrition and gastrointestinal obstruction. This population could benefit from home parenteral nutrition (HPN). The aim of this study was to observe the outcome of patients with advanced cancer patients who were eligible for HPN. All patients in the nutrition clinic who received HPN over the past 7 y were included in the present study. We compared patients with advanced cancer with the noncancer population in terms of hospitalization rate and mortality. Of 221 advanced cancer patients, 153 who had no oral/enteral intake and who received HPN survived. Of these, 35% survived for 6 mo, 27% for 1 y, 18.9% survived 2 y, and 3.9% survived for the 7 y of the follow-up. Hospitalization rate was not significantly different from the noncancer population. These results show that HPN is a relevant palliative therapy for patients with advanced cancer patients without oral or enteral feeding access. Copyright © 2017 Elsevier Inc. All rights reserved.

Estimating the personal cure rate of cancer patients using population-based grouped cancer survival data.

PubMed

Binbing Yu; Tiwari, Ram C; Feuer, Eric J

2011-06-01

Cancer patients are subject to multiple competing risks of death and may die from causes other than the cancer diagnosed. The probability of not dying from the cancer diagnosed, which is one of the patients' main concerns, is sometimes called the 'personal cure' rate. Two approaches of modelling competing-risk survival data, namely the cause-specific hazards approach and the mixture model approach, have been used to model competing-risk survival data. In this article, we first show the connection and differences between crude cause-specific survival in the presence of other causes and net survival in the absence of other causes. The mixture survival model is extended to population-based grouped survival data to estimate the personal cure rate. Using the colorectal cancer survival data from the Surveillance, Epidemiology and End Results Programme, we estimate the probabilities of dying from colorectal cancer, heart disease, and other causes by age at diagnosis, race and American Joint Committee on Cancer stage.

The use of sequential mark-release-recapture experiments to estimate population size, survival and dispersal of male mosquitoes of the  Anopheles gambiae complex in Bana, a west African humid savannah village.

PubMed

Epopa, Patric Stephane; Millogo, Abdoul Azize; Collins, Catherine Matilda; North, Ace; Tripet, Frederic; Benedict, Mark Quentin; Diabate, Abdoulaye

2017-08-07

Vector control is a major component of the malaria control strategy. The increasing spread of insecticide resistance has encouraged the development of new tools such as genetic control which use releases of modified male mosquitoes. The use of male mosquitoes as part of a control strategy requires an improved understanding of male mosquito biology, including the factors influencing their survival and dispersal, as well as the ability to accurately estimate the size of a target mosquito population. This study was designed to determine the seasonal variation in population size via repeated mark-release-recapture experiments and to estimate the survival and dispersal of male mosquitoes of the Anopheles gambiae complex in a small west African village. Mark-release-recapture experiments were carried out in Bana Village over two consecutive years, during the wet and the dry seasons. For each experiment, around 5000 (3407-5273) adult male Anopheles coluzzii mosquitoes were marked using three different colour dye powders (red, blue and green) and released in three different locations in the village (centre, edge and outside). Mosquitoes were recaptured at sites spread over the village for seven consecutive days following the releases. Three different capture methods were used: clay pots, pyrethroid spray catches and swarm sampling. Swarm sampling was the most productive method for recapturing male mosquitoes in the field. Population size and survival were estimated by Bayesian analyses of the Fisher-Ford model, revealing an about 10-fold increase in population size estimates between the end of dry season (10,000-50,000) to the wet season (100,000-500,000). There were no detectable seasonal effects on mosquito survival, suggesting that factors other than weather may play an important role. Mosquito dispersal ranged from 40 to 549 m over the seven days of each study and was not influenced by the season, but mainly by the release location, which explained more than 44% of the variance in net dispersal distance. This study clearly shows that male-based MRR experiments can be used to estimate some parameters of wild male populations such as population size, survival, and dispersal and to estimate the spatial patterns of movement in a given locality.

Adult survival of Black-legged Kittiwakes Rissa tridactyla in a Pacific colony

USGS Publications Warehouse

Hatch, Scott A.; Roberts, Bay D.; Fadely, Brian S.

1993-01-01

Breeding Black-legged Kittiwakes Rissa tridactyla survived at a mean annual rate of 0.926 in four years at a colony in Alaska. Survival rates observed in sexed males (0.930) and females (0.937) did not differ significantly. The rate of return among nonbreeding Kittiwakes (0.839) was lower than that of known breeders, presumably because more nonbreeders moved away from the study plots where they were marked. Individual nonbreeders frequented sites up to 5 km apart on the same island, while a few established breeders moved up to 2.5 km between years. Mate retention in breeding Kittiwakes averaged 69% in three years. Among pairs that split, the cause of changing mates was about equally divided between death (46%) and divorce (54%). Average adult life expectancy was estimated at 13.0 years. Combined with annual productivity averaging 0.17 chick per nest, the observed survival was insufficient for maintaining population size. Rather, an irregular decline observed in the study colony since 1981 is consistent with the model of a closed population with little or no recruitment. Compared to their Atlantic counterparts, Pacific Kittiwakes have low productivity and high survival. The question arises whether differences reflect phenotypic plasticity or genetically determined variation in population parameters.

Movements and survival of black-footed ferrets associated with an experimental translocation in South Dakota

USGS Publications Warehouse

Biggins, D.E.; Godbey, J.L.; Horton, B.M.; Livieri, T.M.

2011-01-01

Black-footed ferrets (Mustela nigripes) apparently were extirpated from all native habitats by 1987, and their repatriation requires a combination of captive breeding, reintroductions, and translocations among sites. Improvements in survival rates of released ferrets have resulted from experience in quasi-natural environments during their rearing. Reestablishment of a self-sustaining wild population by 1999 provided the 1st opportunity to initiate new populations by translocating wild-born individuals. Using radiotelemetry, we compared behaviors and survival of 18 translocated wild-born ferrets and 18 pen-experienced captive-born ferrets after their release into a prairie dog colony not occupied previously by ferrets. Translocated wild-born ferrets moved significantly less and had significantly higher short-term survival rates than their captive-born counterparts. Using markrecapture methods, we also assessed potential impacts to the established donor population of removing 37% of its estimated annual production of kits. Annual survival rates for 30 ferret kits remaining at the donor subcomplex were higher than rates for 54 ferret kits at the control subcomplex (unmanipulated) for males (+82%) and females (+32%). Minimum survival of translocated kits did not differ significantly from survival of those at the control subcomplex. Direct translocation of young, wild-born ferrets from site to site appears to be an efficient method to establish new populations. ?? 2011 American Society of Mammalogists.

Assessment of survival rates and reproductive success of captive bred milky stork released at Kuala Gula Bird Sanctuary, Perak

NASA Astrophysics Data System (ADS)

Faiq, H.; Safie, M. Y.; Shukor, M. N.

2016-11-01

A release programme of captive bred Milky Storks was initiated to increase population size in the wild. Population size depends on the survival rate and breeding success of individuals in the population. Among factors that affect survival rate and breeding success are population age class and sex ratio. The main objective of this study was to estimate the survival rate of Mycteria cinerea that has been released in Kuala Gula Bird Sanctuary since 2007. The estimation of the survival rate was done across gender and age class. This study was conducted in 2012 at Kuala Gula Bird Sanctuary. The presence of M. cinerea individuals were recorded at the sanctuary and identified to background information, such as date of birth, gender and date of release. Females of M. cinerea were estimated to have a higher survival rate (30.0%) than male (16.7%). Across gender, each individual was assigned into 4 different age classes, namely less than 1 year, between 1 and 2 years, between 2 and 3 years, and more than 3 years. The survival rate of individuals less than 1 year was about 50%, between 1 and 2 years was 25%, between 2 and 3 years was 9.1%, and more than 3 years was 0%. This study was intended to facilitate future release programmeme on which gender and age class to emphasize.

Population dynamics of mallards breeding in eastern Washington

USGS Publications Warehouse

Dugger, Bruce D.; Coluccy, John M.; Dugger, Katie M.; Fox, Trevor T.; Kraege, Donald K.; Petrie, Mark J.

2016-01-01

Variation in regional population trends for mallards breeding in the western United States indicates that additional research into factors that influence demographics could contribute to management and understanding the population demographics of mallards across North America. We estimated breeding incidence and adult female, nest, and brood survival in eastern Washington in 2006 and 2007 by monitoring female mallards with radio telemetry and tested how those parameters were influenced by study year (2006 vs. 2007), landscape type (agricultural vs. natural), and age (second year [SY] vs. after second year [ASY]). We also investigated the effects of female body condition and capture date on breeding incidence, and nest initiation date and hatch date on nest and brood survival, respectively. We included population parameters in a stage-based demographic model and conducted a perturbation analysis to identify which vital rates were most influential on population growth rate (λ). Adult female survival was best modeled with a constant weekly survival rate (0.994, SE = 0.003). Breeding incidence differed between years and was higher for birds in better body condition. Nest survival was higher for ASY females (0.276, SE = 0.118) than SY females (0.066, SE = 0.052), and higher on publicly managed lands (0.383, SE = 0.212) than agricultural (0.114, SE = 0.058) landscapes. Brood survival was best modeled with a constant rate for the 7-week monitoring period (0.50, SE = 0.155). The single variable having the greatest influence on λ was non-breeding season survival, but the combination of parameters from the breeding grounds explained a greater percent of the variance in λ. Mallard population growth rate was most sensitive to changes in non-breeding survival, nest success, brood survival, and breeding incidence. Future management decisions should focus on activities that improve these vital rates if managers want to increase the production of mallards in eastern Washington.

Testing for genetic differences in survival and growth between hatchery and wild Chinook salmon from Warm Springs River, Oregon (Study sites: Warm Springs Hatchery and Little White Salmon River; Stocks: Warm Springs hatchery and Warm Springs River wild; Year classes: 1992 and 1996): Chapter 8

USGS Publications Warehouse

Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Leonetti,; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

2012-01-01

The program at Warm Springs National Fish Hatchery in north - central Oregon was initiated with spring Chinook salmon Oncorhynchus tshawytscha from the Warm Springs River. Managers included wild fish in the broodstock most years and avoided artificial selection to minimize genetic divergence from the wild founder population. We tested for genetic differences in survival and growth between the hatchery and wild populations to ascertain whether this goal has been achieved. Progeny of hatchery x hatchery (HH), hatchery female x wild male (HW), and wild x wild (WW) crosses were genetically marked at the sSOD - 1* allozyme locus and released together as unfed fry in hatchery ponds in 1992 and 1996 and in the Little White Salmon River, in south - central Washington, in 1996. Fish were evaluated to returning adult at the hatchery and over their freshwater residence of 16 months in the stream. The three crosses differed on several measures including survival to outmigration in the stream (WW>HH>HW) and juvenile growth in the hatchery (1992 year - class; WW>HW>HH); however, results may have been confounded. The genetic marks were found to differentially effect survival in a companion study (HH mark favored over WW mark; HW mark intermediate). Furthermore, HW survival in the current study was neither intermediate, as would be expect ed from additive genetic effects, nor similar to that of HH fish as would be expected from maternal effects since HW and HH fish were maternal half - siblings. Finally, the unexpected performance of HW fish precludes ruling out maternal differences between hatchery and wild mothers as the cause of differences between HH and WW fish. The key finding that survival of HH fish in a stream was 0.91 that for WW fish, indicating a small loss of fitness for natural rearing in the hatchery population, is valid only if three conditions hold: (1) any selection on the genetic marks was in the same direction as in the companion study, (2) lower survival in the stream for HW than for HH fish resulted because some HW families were genetically atypical, not from problems w ith either pure type, and (3) lower survival for HH than for WW fish was not due to maternal effects. Although all three conditions had support, none of it was conclusive. This study provides only suggestions, not definitive answers for the primary quest ion of whether the hatchery population has diverged genetically from its wild founder population in fitness - related traits.

Establishing a Wild, Ex Situ Population of a Critically Endangered Shade-Tolerant Rainforest Conifer: A Translocation Experiment

PubMed Central

Zimmer, Heidi C.; Offord, Catherine A.; Auld, Tony D.; Baker, Patrick J.

2016-01-01

Translocation can reduce extinction risk by increasing population size and geographic range, and is increasingly being used in the management of rare and threatened plant species. A critical determinant of successful plant establishment is light environment. Wollemia nobilis (Wollemi pine) is a critically endangered conifer, with a wild population of 83 mature trees and a highly restricted distribution of less than 10 km2. We used under-planting to establish a population of W. nobilis in a new rainforest site. Because its optimal establishment conditions were unknown, we conducted an experimental translocation, planting in a range of different light conditions from deeply shaded to high light gaps. Two years after the experimental translocation, 85% of plants had survived. There were two distinct responses: very high survival (94%) but very low growth, and lower survival (69%) and higher growth, associated with initial plant condition. Overall survival of translocated W. nobilis was strongly increased in planting sites with higher light, in contrast to previous studies demonstrating long-term survival of wild W. nobilis juveniles in deep shade. Translocation by under-planting may be useful in establishing new populations of shade-tolerant plant species, not least by utilizing the range of light conditions that occur in forest understories. PMID:27403527

Establishing a Wild, Ex Situ Population of a Critically Endangered Shade-Tolerant Rainforest Conifer: A Translocation Experiment.

PubMed

Zimmer, Heidi C; Offord, Catherine A; Auld, Tony D; Baker, Patrick J

2016-01-01

Translocation can reduce extinction risk by increasing population size and geographic range, and is increasingly being used in the management of rare and threatened plant species. A critical determinant of successful plant establishment is light environment. Wollemia nobilis (Wollemi pine) is a critically endangered conifer, with a wild population of 83 mature trees and a highly restricted distribution of less than 10 km2. We used under-planting to establish a population of W. nobilis in a new rainforest site. Because its optimal establishment conditions were unknown, we conducted an experimental translocation, planting in a range of different light conditions from deeply shaded to high light gaps. Two years after the experimental translocation, 85% of plants had survived. There were two distinct responses: very high survival (94%) but very low growth, and lower survival (69%) and higher growth, associated with initial plant condition. Overall survival of translocated W. nobilis was strongly increased in planting sites with higher light, in contrast to previous studies demonstrating long-term survival of wild W. nobilis juveniles in deep shade. Translocation by under-planting may be useful in establishing new populations of shade-tolerant plant species, not least by utilizing the range of light conditions that occur in forest understories.

Comment on 'Are survival rates for northern spotted owls biased?'

USGS Publications Warehouse

Franklin, A.B.; Nichols, J.D.; Anthony, R.G.; Burnham, K.P.; White, Gary C.; Forsman, E.D.; Anderson, D.R.

2006-01-01

Loehle et al. recently estimated survival rates from radio-telemetered northern spotted owls (Strix occidentalis caurina (Merriam, 1898)) and suggested that survival rates estimated for this species from capture-recapture studies were negatively biased, which subsequently resulted in the negatively biased estimates of rates of population change (lambda) reported by Anthony et al. (Wildl. Monogr. No. 163, pp. 1-47 (2006)). We argue that their survival estimates were inappropriate for comparison with capture-recapture estimates because (i) the manner in which they censored radio-telemetered individuals had the potential to positively bias their survival estimates, (ii) their estimates of survival were not valid for evaluating bias, and (iii) the size and distribution of their radiotelemetry study areas were sufficiently different from capture-recapture study areas to preclude comparisons. In addition, their inferences of negative bias in rates of population change estimated by Anthony et al. were incorrect and reflected a misunderstanding about those estimators.

Desert tortoise (Gopherus agassizii) survival at two eastern Mojave Desert sites: Death by short-term drought?

USGS Publications Warehouse

Longshore, Kathleen M.; Jaeger, Jef R.; Sappington, J. Mark

2003-01-01

Survival of adult Desert Tortoises (Gopherus agassizii) appears related to site-specific variation in precipitation and productivity of annual plants. We studied adult tortoise survival rates at two closely situated, but physiographically different, sites in the eastern Mojave Desert over a nine-year period (spring 1992 to spring 2001). Survival rates were initially derived from population surveys conducted over a three-year period and by radio-telemetry monitoring over a seven-year period beginning in 1994. After a period of initial stability, survival rates on the two sites diverged over the study period, and seven-year survival rates estimated from radio-telemetry monitoring were 0.900 and 0.269, respectively. A die-off in 1996 on the latter site appears to have been triggered by a period of drought, which began in the summer of 1995, coupled with a failure of annual vegetation production in 1996. Depressed survival rates on this site were associated with drought conditions during three of four years. Although the decline had the appearance of an epizootic, there were no clinical signs of disease. Relatively short-term drought, combined with little or no annual biomass, appears to have caused severe reductions in tortoise survival. If periods of drought-induced low survival are common over relatively small areas, then source-sink population dynamics may be an important factor determining tortoise population densities.

Thermal plasticity in life-history traits in the polymorphic blue-tailed damselfly, Ischnura elegans: no differences between female morphs.

PubMed

Bouton, Niels; Iserbyt, Arne; Van Gossum, Hans

2011-01-01

Female polymorphism is observed in various animal species, but is particularly common in damselflies. The maintenance of this polymorphism has traditionally been explained from frequency and density dependent sexual conflict, however, the role of abiotic factors has recently attracted more interest. Here, the role of ambient temperature in shaping life-history was investigated for the three female morphs of Ischnura elegans (Vander Linden) (Zygoptera: Coenagrionidae). Eggs were obtained from the three mature female morphs for two populations in the Netherlands. Using a split-brood design, eggs of both populations were divided between a cold and a warm treatment group in the laboratory, and egg survival and hatching time were measured. Significant thermal plasticity was found in both hatching time and egg survival between both temperature treatments. However, individuals born to mothers belonging to different colour morphs did not differ in their response to temperature treatment. Independent of colour morph, clear differences in both life-history traits between the populations were found, suggesting local adaptation. Specifically, individuals from one population hatched faster but had lower egg survival in both thermal regimes. The selection force establishing fast hatching could be (facultative) bivoltinism in one of the populations compared to univoltinism in the other. This would be in line with the more southern (and more coastal) location of the presumed bivoltine population and the inverse relation between voltinism and latitude known from earlier studies. However, other natural selection forces, e.g. deterioration of the aquatic habitat, may also drive fast hatching.

Survival of Patients with Oral Cavity Cancer in Germany

PubMed Central

Listl, Stefan; Jansen, Lina; Stenzinger, Albrecht; Freier, Kolja; Emrich, Katharina; Holleczek, Bernd; Katalinic, Alexander; Gondos, Adam; Brenner, Hermann

2013-01-01

The purpose of the present study was to describe the survival of patients diagnosed with oral cavity cancer in Germany. The analyses relied on data from eleven population-based cancer registries in Germany covering a population of 33 million inhabitants. Patients with a diagnosis of oral cavity cancer (ICD-10: C00-06) between 1997 and 2006 are included. Period analysis for 2002–2006 was applied to estimate five-year age-standardized relative survival, taking into account patients' sex as well as grade and tumor stage. Overall five-year relative survival for oral cavity cancer patients was 54.6%. According to tumor localization, five-year survival was 86.5% for lip cancer, 48.1% for tongue cancer and 51.7% for other regions of the oral cavity. Differences in survival were identified with respect to age, sex, tumor grade and stage. The present study is the first to provide a comprehensive overview on survival of oral cavity cancer patients in Germany. PMID:23349710

Estimating survival and breeding probability for pond-breeding amphibians: a modified robust design

USGS Publications Warehouse

Bailey, L.L.; Kendall, W.L.; Church, D.R.; Wilbur, H.M.

2004-01-01

Many studies of pond-breeding amphibians involve sampling individuals during migration to and from breeding habitats. Interpreting population processes and dynamics from these studies is difficult because (1) only a proportion of the population is observable each season, while an unknown proportion remains unobservable (e.g., non-breeding adults) and (2) not all observable animals are captured. Imperfect capture probability can be easily accommodated in capture?recapture models, but temporary transitions between observable and unobservable states, often referred to as temporary emigration, is known to cause problems in both open- and closed-population models. We develop a multistate mark?recapture (MSMR) model, using an open-robust design that permits one entry and one exit from the study area per season. Our method extends previous temporary emigration models (MSMR with an unobservable state) in two ways. First, we relax the assumption of demographic closure (no mortality) between consecutive (secondary) samples, allowing estimation of within-pond survival. Also, we add the flexibility to express survival probability of unobservable individuals (e.g., ?non-breeders?) as a function of the survival probability of observable animals while in the same, terrestrial habitat. This allows for potentially different annual survival probabilities for observable and unobservable animals. We apply our model to a relictual population of eastern tiger salamanders (Ambystoma tigrinum tigrinum). Despite small sample sizes, demographic parameters were estimated with reasonable precision. We tested several a priori biological hypotheses and found evidence for seasonal differences in pond survival. Our methods could be applied to a variety of pond-breeding species and other taxa where individuals are captured entering or exiting a common area (e.g., spawning or roosting area, hibernacula).

Development and Survival of Spodoptera exigua (Lepidoptera: Noctuidae) on Alternate Crops in Cotton Cropping Pattern, With Implications to Integrated Pest Management.

PubMed

Saeed, Qamar; Ahmad, Faheem; Saeed, Shafqat

2017-06-01

Spodoptera exigua (Hübner) is a polyphagous pest that shifts its population to different hosts during its life cycle to receive nutritive advantages. Therefore, demographic evaluation of alternate hosts is important for effective pest management. Here, we have evaluated castor (Ricinus communis L.), cauliflower (Brassica oleracea L.), cotton (Gossypium hirsutum L.), okra (Abelmoschus esculentus L.), and spinach (Spinacia oleracea L.) for growth, survival, and population development of S. exigua. Development of early populations of S. exigua is best supported on castor where earlier instars had least mortalities (10%) compared with spinach (36%), although later instars and pupae had significantly higher mortalities (20.8%) on it. Spinach and okra, on the other hand, promote larval survivals in later instars. Little or no differences in stadia lengths were observed during early development of larvae and, interestingly, the longevity of female moths increased significantly when reared on castor, cauliflower, and spinach (12.3, 11.3, and 11.7 d, respectively), resulting into significantly higher fecundity. The survival curves of all five populations have clearly demonstrated a steep early decline in larval numbers when reared on okra and only 60% larvae could survive. These findings conclude that S. exigua when fed on spinach was greatly disadvantaged in terms of growth and development; hence, the pest's field population can be opportunistically controlled by spraying adjacent spinach fields. In addition, the results highlight the vulnerable stages in pest's life cycle in the field where we can apply integrated control strategies for its effective management. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Desiccation tolerance as a function of age, sex, humidity and temperature in adults of the African malaria vectors Anopheles arabiensis and Anopheles funestus.

PubMed

Lyons, Candice L; Coetzee, Maureen; Terblanche, John S; Chown, Steven L

2014-11-01

Adult mosquito survival is strongly temperature and moisture dependent. Few studies have investigated the interacting effects of these variables on adult survival and how this differs among the sexes and with age, despite the importance of such information for population dynamic models. For these reasons, the desiccation tolerance of Anopheles arabiensis Patton and Anopheles funestus Giles males and females of three different ages was assessed under three combinations of temperature and humidity. Females were more desiccation tolerant than males, surviving for longer periods than males under all experimental conditions. In addition, younger adults were more tolerant of desiccation than older groups. Both species showed reduced water loss rate (WLR) as the primary mechanism by which they tolerate desiccation. Although A. arabiensis is often considered to be the more arid-adapted of the two species, it showed lower survival times and higher WLR than A. funestus. The current information could improve population dynamic models of these vectors, given that adult survival information for such models is relatively sparse. © 2014. Published by The Company of Biologists Ltd.

Comparison of survival patterns of northern and southern genotypes of the North American tick Ixodes scapularis (Acari: Ixodidae) under northern and southern conditions

USGS Publications Warehouse

Ginsberg, Howard S.; Rulison, Eric L.; Azevedo, Alexandra; Pang, Genevieve C.; Kuczaj, Isis M.; Tsao, Jean I.; LeBrun, Roger A.

2014-01-01

BackgroundSeveral investigators have reported genetic differences between northern and southern populations of Ixodes scapularis in North America, as well as differences in patterns of disease transmission. Ecological and behavioral correlates of these genetic differences, which might have implications for disease transmission, have not been reported. We compared survival of northern with that of southern genotypes under both northern and southern environmental conditions in laboratory trials.MethodsSubadult I. scapularis from laboratory colonies that originated from adults collected from deer from several sites in the northeastern, north central, and southern U.S. were exposed to controlled conditions in environmental chambers. Northern and southern genotypes were exposed to light:dark and temperature conditions of northern and southern sites with controlled relative humidities, and mortality through time was recorded.ResultsTicks from different geographical locations differed in survival patterns, with larvae from Wisconsin surviving longer than larvae from Massachusetts, South Carolina or Georgia, when held under the same conditions. In another experiment, larvae from Florida survived longer than larvae from Michigan. Therefore, survival patterns of regional genotypes did not follow a simple north–south gradient. The most consistent result was that larvae from all locations generally survived longer under northern conditions than under southern conditions.ConclusionsOur results suggest that conditions in southern North America are less hospitable than in the north to populations of I. scapularis. Southern conditions might have resulted in ecological or behavioral adaptations that contribute to the relative rarity of I. scapularis borne diseases, such as Lyme borreliosis, in the southern compared to the northern United States.

Estimating latent time of maturation and survival costs of reproduction in continuous time from capture-recapture data

USGS Publications Warehouse

Ergon, T.; Yoccoz, N.G.; Nichols, J.D.; Thomson, David L.; Cooch, Evan G.; Conroy, Michael J.

2009-01-01

In many species, age or time of maturation and survival costs of reproduction may vary substantially within and among populations. We present a capture-mark-recapture model to estimate the latent individual trait distribution of time of maturation (or other irreversible transitions) as well as survival differences associated with the two states (representing costs of reproduction). Maturation can take place at any point in continuous time, and mortality hazard rates for each reproductive state may vary according to continuous functions over time. Although we explicitly model individual heterogeneity in age/time of maturation, we make the simplifying assumption that death hazard rates do not vary among individuals within groups of animals. However, the estimates of the maturation distribution are fairly robust against individual heterogeneity in survival as long as there is no individual level correlation between mortality hazards and latent time of maturation. We apply the model to biweekly capture?recapture data of overwintering field voles (Microtus agrestis) in cyclically fluctuating populations to estimate time of maturation and survival costs of reproduction. Results show that onset of seasonal reproduction is particularly late and survival costs of reproduction are particularly large in declining populations.

Factors that influence vital rates of Seaside and Saltmarsh sparrows in coastal New Jersey, USA

PubMed Central

Roberts, Samuel G.; Longenecker, Rebecca A.; Etterson, Matthew A.; Ruskin, Katharine J.; Elphick, Chris S.; Olsen, Brian J.; Shriver, W. Gregory

2018-01-01

As saltmarsh habitat continues to disappear, understanding the factors that influence saltmarsh breeding bird population dynamics is an important step for the conservation of these declining species. Using five years (2011 – 2015) of demographic data, we evaluated and compared Seaside (Ammodramus maritimus) and Saltmarsh (A. caudacutus) sparrow apparent adult survival and nest survival at the Edwin B. Forsythe National Wildlife Refuge, New Jersey, USA. We determined the effect of site management history (unditched vs. ditched marsh) on adult and nest survival to aid in prioritizing future management or restoration actions. Seaside Sparrow apparent adult survival (61.6%, 95% CI: 52.5 – 70.0%) averaged >1.5 times greater than Saltmarsh Sparrow apparent adult survival (39.9%, 95% CI: 34.0 – 46.2%). Nest survival and predation and flooding rates did not differ between species, and predation was the primary cause of failure for both species. Apparent adult survival and nest survival did not differ between unditched and ditched marshes for either species, indicating that marsh ditching history may not affect breeding habitat quality for these species. With predation as the primary cause of nest failure for both species in New Jersey, we suggest that future research should focus on identification of predator communities in salt marshes and the potential for implementing predator-control programs to limit population declines. PMID:29479129

Adjusting Expected Mortality Rates Using Information From a Control Population: An Example Using Socioeconomic Status.

PubMed

Bower, Hannah; Andersson, Therese M-L; Crowther, Michael J; Dickman, Paul W; Lambe, Mats; Lambert, Paul C

2018-04-01

Expected or reference mortality rates are commonly used in the calculation of measures such as relative survival in population-based cancer survival studies and standardized mortality ratios. These expected rates are usually presented according to age, sex, and calendar year. In certain situations, stratification of expected rates by other factors is required to avoid potential bias if interest lies in quantifying measures according to such factors as, for example, socioeconomic status. If data are not available on a population level, information from a control population could be used to adjust expected rates. We have presented two approaches for adjusting expected mortality rates using information from a control population: a Poisson generalized linear model and a flexible parametric survival model. We used a control group from BCBaSe-a register-based, matched breast cancer cohort in Sweden with diagnoses between 1992 and 2012-to illustrate the two methods using socioeconomic status as a risk factor of interest. Results showed that Poisson and flexible parametric survival approaches estimate similar adjusted mortality rates according to socioeconomic status. Additional uncertainty involved in the methods to estimate stratified, expected mortality rates described in this study can be accounted for using a parametric bootstrap, but this might make little difference if using a large control population.

Incorporating Temperature-driven Seasonal Variation in Survival, Growth, and Reproduction Models for Small Fish

EPA Science Inventory

Seasonal variation in survival and reproduction can be a large source of prediction uncertainty in models used for conservation and management. A seasonally varying matrix population model is developed that incorporates temperature-driven differences in mortality and reproduction...

Cancer survival in Australia, Canada, Denmark, Norway, Sweden, and the UK, 1995–2007 (the International Cancer Benchmarking Partnership): an analysis of population-based cancer registry data

PubMed Central

Coleman, MP; Forman, D; Bryant, H; Butler, J; Rachet, B; Maringe, C; Nur, U; Tracey, E; Coory, M; Hatcher, J; McGahan, CE; Turner, D; Marrett, L; Gjerstorff, ML; Johannesen, TB; Adolfsson, J; Lambe, M; Lawrence, G; Meechan, D; Morris, EJ; Middleton, R; Steward, J; Richards, MA

2011-01-01

Summary Background Cancer survival is a key measure of the effectiveness of health-care systems. Persistent regional and international differences in survival represent many avoidable deaths. Differences in survival have prompted or guided cancer control strategies. This is the first study in a programme to investigate international survival disparities, with the aim of informing health policy to raise standards and reduce inequalities in survival. Methods Data from population-based cancer registries in 12 jurisdictions in six countries were provided for 2·4 million adults diagnosed with primary colorectal, lung, breast (women), or ovarian cancer during 1995–2007, with follow-up to Dec 31, 2007. Data quality control and analyses were done centrally with a common protocol, overseen by external experts. We estimated 1-year and 5-year relative survival, constructing 252 complete life tables to control for background mortality by age, sex, and calendar year. We report age-specific and age-standardised relative survival at 1 and 5 years, and 5-year survival conditional on survival to the first anniversary of diagnosis. We also examined incidence and mortality trends during 1985–2005. Findings Relative survival improved during 1995–2007 for all four cancers in all jurisdictions. Survival was persistently higher in Australia, Canada, and Sweden, intermediate in Norway, and lower in Denmark, England, Northern Ireland, and Wales, particularly in the first year after diagnosis and for patients aged 65 years and older. International differences narrowed at all ages for breast cancer, from about 9% to 5% at 1 year and from about 14% to 8% at 5 years, but less or not at all for the other cancers. For colorectal cancer, the international range narrowed only for patients aged 65 years and older, by 2–6% at 1 year and by 2–3% at 5 years. Interpretation Up-to-date survival trends show increases but persistent differences between countries. Trends in cancer incidence and mortality are broadly consistent with these trends in survival. Data quality and changes in classification are not likely explanations. The patterns are consistent with later diagnosis or differences in treatment, particularly in Denmark and the UK, and in patients aged 65 years and older. Funding Department of Health, England; and Cancer Research UK. PMID:21183212

The TP53 gene polymorphisms and survival of sporadic breast cancer patients.

PubMed

Bišof, V; Salihović, M Peričić; Narančić, N Smolej; Skarić-Jurić, T; Jakić-Razumović, J; Janićijević, B; Rudan, P

2012-06-01

The TP53 gene polymorphisms, Arg72Pro and PIN3 (+16 bp), can have prognostic and predictive value in different cancers including breast cancer. The aim of the present study is to investigate a potential association between different genotypes of these polymorphisms and clinicopathological variables with survival of breast cancer patients in Croatian population. Ninety-four women with sporadic breast cancer were retrospectively analyzed. Median follow-up period was 67.9 months. The effects of basic clinical and histopathological characteristics of tumor on survival were tested by Cox's proportional hazards regression analysis. The TNM stage was associated with overall survival by Kaplan-Meier analysis, univariate, and multivariate Cox's proportional hazards regression analysis, while grade was associated with survival by Kaplan-Meier analysis and univariate Cox's proportional hazards regression analysis. Different genotypes of the Arg72Pro and PIN3 (+16 bp) polymorphisms had no significant impact on survival in breast cancer patients. However, in subgroup of patients treated with chemotherapy without anthracycline, the A2A2 genotype of the PIN3 (+16 bp) polymorphism was associated with poorer overall survival than other genotypes by Kaplan-Meier analysis (P = 0.048). The TP53 polymorphisms, Arg72Pro and PIN3 (+16 bp), had no impact on survival in unselected sporadic breast cancer patients in Croatian population. However, the results support the role of the A2A2 genotype of the PIN3 (+16 bp) polymorphism as a marker for identification of patients that may benefit from anthracycline-containing chemotherapy.

Environmental pollution has sex-dependent effects on local survival

PubMed Central

Eeva, Tapio; Hakkarainen, Harri; Laaksonen, Toni; Lehikoinen, Esa

2006-01-01

Environmental pollutants cause a potential hazard for survival in free-living animal populations. We modelled local survival (including emigration) by using individual mark–recapture histories of males and females in a population of a small insectivorous passerine bird, the pied flycatcher (Ficedula hypoleuca) living around a point source of heavy metals (copper smelter). Local survival of F. hypoleuca females did not differ between polluted and unpolluted environments. Males, however, showed a one-third higher local-survival probability in the polluted area. Low fledgling production was generally associated with decreased local survival, but males in the polluted area showed relatively high local survival, irrespective of their fledgling number. A possible explanation of higher local survival of males in the polluted area could be a pollution-induced change in hormone (e.g. corticosterone or testosterone) levels of males. It could make them to invest more on their own survival or affect the hormonal control of breeding dispersal. The local survival of males decreased in the polluted area over the study period along with the simultaneous decrease in heavy metal emissions. This temporal trend is in agreement with the stress hormone hypothesis. PMID:17148387

Winter fidelity and apparent survival of lesser snow goose populations in the Pacific flyway

USGS Publications Warehouse

Williams, C.K.; Samuel, M.D.; Baranyuk, Vasily V.; Cooch, E.G.; Kraege, Donald K.

2008-01-01

The Beringia region of the Arctic contains 2 colonies of lesser snow geese (Chen caerulescens caerulescens) breeding on Wrangel Island, Russia, and Banks Island, Canada, and wintering in North America. The Wrangel Island population is composed of 2 subpopulations from a sympatric breeding colony but separate wintering areas, whereas the Banks Island population shares a sympatric wintering area in California, USA, with one of the Wrangel Island subpopulations. The Wrangel Island colony represents the last major snow goose population in Russia and has fluctuated considerably since 1970, whereas the Banks Island population has more than doubled. The reasons for these changes are unclear, but hypotheses include independent population demographics (survival and recruitment) and immigration and emigration among breeding or wintering populations. These demographic and movement patterns have important ecological and management implications for understanding goose population structure, harvest of admixed populations, and gene flow among populations with separate breeding or wintering areas. From 1993 to 1996, we neckbanded molting birds at their breeding colonies and resighted birds on the wintering grounds. We used multistate mark-recapture models to evaluate apparent survival rates, resighting rates, winter fidelity, and potential exchange among these populations. We also compared the utility of face stain in Wrangel Island breeding geese as a predictor of their wintering area. Our results showed similar apparent survival rates between subpopulations of Wrangel Island snow geese and lower apparent survival, but higher emigration, for the Banks Island birds. Males had lower apparent survival than females, most likely due to differences in neckband loss. Transition between wintering areas was low (<3%), with equal movement between northern and southern wintering areas for Wrangel Island birds and little evidence of exchange between the Banks and northern Wrangel Island populations. Face staining was an unreliable indicator of wintering area. Our findings suggest that northern and southern Wrangel Island subpopulations should be considered a metapopulation in better understanding and managing Pacific Flyway lesser snow geese. Yet the absence of a strong population connection between Banks Island and Wrangel Island geese suggests that these breeding colonies can be managed as separate but overlapping populations. Additionally, winter population fidelity may be more important in lesser snow geese than in other species, and both breeding and wintering areas are important components of population management for sympatric wintering populations.

Annual survival and population estimates of Mountain Plovers in Southern Phillips County, Montana

USGS Publications Warehouse

Dinsmore, S.J.; White, Gary C.; Knopf, F.L.

2003-01-01

Information about the demography of declining species is especially relevant to their conservation and future recovery. Knowledge of survival rates and population size can be used to assess long-term viability and population trends, both of which are of interest to conservation biologists. We used capture–recapture techniques to study the demography of Mountain Plovers (Charadrius montanus Townsend) in southern Phillips County, Montana, USA, in 1995–2000. We used the robust design to estimate annual survival (φ), conditional capture (p and r) and recapture (c) probabilities, and the annual population size (N) in the presence of temporary emigration. The results support age-specific differences in annual survival that are a function of juvenile body mass and are correlated with the area occupied by prairie dogs. Body mass had a positive effect on juvenile survival; the slope coefficient for the additive effect of body mass on juvenile survival was 0.77 (95% ci = 0.25, 1.28) on a logit scale. A measure of plover habitat (the area occupied by prairie dogs) appeared to have no effect on survival; the slope coefficient for the additive effect of area occupied by prairie dogs on survival was –0.00004 (95% ci = –0.00003, –0.0001) on a logit scale. Estimated annual apparent survival rates were 0.46–0.49 for juveniles and 0.68 for adult plovers. Using these estimates, the life span of a Mountain Plover was 1.92 ± 0.17 years (mean ± 1 se) from time of capture as a chick. Resighting rates positively influenced capture probabilities; the slope coefficient for the additive resighting effect was –0.49 (95% ci = –0.86, –0.11) on a logit scale. The size of this adult Mountain Plover population was estimated at 95–180 adults annually. Population size closely tracked annual changes in the area occupied by black-tailed prairie dogs, with both plovers and prairie dogs rapidly recovering from an outbreak of sylvatic plague in the mid-1990s. Given the low annual survival rates and low mean life expectancy of Mountain Plovers, we conclude that sustainable local populations are currently maintained by annual rates of productivity greater than those for other ground-nesting birds.

["That flesh, pink and perishable": analysis of disease-free survival analysis in breast cancer in Gipuzkoa (Spain) in the presence of competing risks].

PubMed

Martínez-Camblor, Pablo; Larrañaga, Nerea; Sarasqueta, Cristina; Mitxelena, María José; Basterretxea, Mikel

2009-01-01

To analyze time of disease-free survival and relative survival in women diagnosed with breast cancer in the province of Gipuzkoa within the context of competing risks by assessing differences between the direct use of the Kaplan-Meier estimator and the multiple decrement method on the one hand, and relative survival on the other. All registered breast cancer cases in Gipuzkoa in 1995 and 1996 with stages other than stage IV were included. An 8-year follow-up for recurrence and a 10-year follow-up for survival were performed. Time of disease-free survival was studied by the multiple decrement model. Observed survival and survival corrected by the expected mortality in the population (relative survival) were also studied. Estimation of the probability of recurrence at 8 years with the multiple decrement method was 8.8% lower than that obtained with the Kaplan-Meier method. The difference between the observed and relative survival rates at 10 years was 10.8%. Both results show how, in this case, the Kaplan-Meier estimator overestimates both the probability of recurrence and that of mortality from the disease. Two issues are often overlooked when performing survival analyses: firstly, because of the lack of independence between survival time and censoring time, the results obtained by the Kaplan-Meier estimator are uninterpretable; secondly, it is an incontrovertible fact that one way or another, everyone causes failures. In this approach, survival analyses must take into account the probability of failure in the general population of reference. The results obtained in this study show that superficial use of the Kaplan Meier estimator overestimates both the probability of recurrence and that of mortality caused by the disease.

Provenance matters: thermal reaction norms for embryo survival among sockeye salmon Oncorhynchus nerka populations.

PubMed

Whitney, C K; Hinch, S G; Patterson, D A

2013-04-01

Differences in thermal tolerance during embryonic development in Fraser River sockeye salmon Oncorhynchus nerka were examined among nine populations in a controlled common-garden incubation experiment. Forcing embryonic development at an extreme temperature (relative to current values) of 16° C, representing a future climate change scenario, significantly reduced survival compared to the more ecologically moderate temperature of 10° C (55% v. 93%). Survival at 14° C was intermediate between the other two temperatures (85%). More importantly, this survival response varied by provenance within and between temperature treatments. Thermal reaction norms showed an interacting response of genotype and environment (temperature), suggesting that populations of O. nerka may have adapted differentially to elevated temperatures during incubation and early development. Moreover, populations that historically experience warmer incubation temperatures at early development displayed a higher tolerance for warm temperatures. In contrast, thermal tolerance does not appear to transcend life stages as adult migration temperatures were not related to embryo thermal tolerance. The intra-population variation implies potential for thermal tolerance at the species level. The differential inter-population variation in thermal tolerance that was observed suggests, however, limited adaptive potential to thermal shifts for some populations. This infers that the intergenerational effects of increasing water temperatures may affect populations differentially, and that such thermally mediated adaptive selection may drive population, and therefore species, persistence. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

Young breast cancer patients who develop distant metastasis after surgery have better survival outcomes compared with elderly counterparts.

PubMed

Wang, Jingjing; Wang, Jiayu; Li, Qing; Zhang, Pin; Yuan, Peng; Ma, Fei; Luo, Yang; Cai, Ruigang; Fan, Ying; Chen, Shanshan; Li, Qiao; Xu, Binghe

2017-07-04

To investigate the recurrence pattern and subsequent survival outcomes in young breast cancer population, 483 young patients (≤ 35) and 739 elderly patients (≥ 65), who received mastectomy or breast-conserving surgery from 2008 to 2012, were included in this study. The young population presented with a higher rate of pathologic tumor stage (P < 0.001), positive pathologic lymph node (P < 0.001), grade III tumors (P < 0.001), and lymphovascular invasion (P < 0.001). With a median follow-up of 56.5 months, young patients had a significantly lower 5-year disease-free survival (73.7% vs 83.4%, P = 0.001), while no difference in 5-year overall survival was observed (91.7% vs 91.7%, P = 0.721). The 5-year cumulative incidences of locoregional relapse (8.9% vs 4.3%, P = 0.009) and distant metastasis (18.8% vs 9.5%, P < 0.001) were significantly higher in the young population. However, for patients with distant metastasis, the survival outcomes were significantly better in the young patients (5-year overall survival since diagnosis: 60.0% vs 47.3%, P = 0.025; 5-year overall survival after recurrence: 31.0% vs 24.3%, P = 0.001). Young breast cancer patients present with more aggressive clinicopathological features and have poor prognosis compared with elderly. But young patients with distant metastasis might have better survival outcomes.

Life history and dynamics of a platypus (Ornithorhynchus anatinus) population: four decades of mark-recapture surveys

PubMed Central

Bino, Gilad; Grant, Tom R.; Kingsford, Richard T.

2015-01-01

Knowledge of the life-history and population dynamics of Australia’s iconic and evolutionarily distinct platypus (Ornithorhynchus anatinus) remains poor. We marked-recaptured 812 unique platypuses (total 1,622 captures), over four decades (1973–2014) in the Shoalhaven River, Australia. Strong sex-age differences were observed in life-history, including morphology and longevity. Apparent survival of adult females (Φ = 0.76) were higher than adult males (Φ = 0.57), as in juveniles: females Φ = 0.27, males Φ = 0.13. Females were highly likely to remain in the same pool (adult: P = 0.85, juvenile: P = 0.88), while residency rates were lower for males (adult: P = 0.74, juvenile: P = 0.46). We combined survival, movement and life-histories to develop population viability models and test the impact of a range of life-history parameters. While using estimated apparent survival produced unviable populations (mean population growth rate r = −0.23, extinction within 20 years), considering residency rates to adjust survival estimates, indicated more stable populations (r = 0.004, p = 0.04 of 100-year extinction). Further sensitivity analyses highlighted adult female survival and overall success of dispersal as most affecting viability. Findings provide robust life-history and viability estimates for a difficult study species. These could support developing large-scale population dynamics models required to underpin a much needed national risk assessment for the platypus, already declining in parts of its current distribution. PMID:26536832

Life history and dynamics of a platypus (Ornithorhynchus anatinus) population: four decades of mark-recapture surveys.

PubMed

Bino, Gilad; Grant, Tom R; Kingsford, Richard T

2015-11-05

Knowledge of the life-history and population dynamics of Australia's iconic and evolutionarily distinct platypus (Ornithorhynchus anatinus) remains poor. We marked-recaptured 812 unique platypuses (total 1,622 captures), over four decades (1973-2014) in the Shoalhaven River, Australia. Strong sex-age differences were observed in life-history, including morphology and longevity. Apparent survival of adult females (Φ = 0.76) were higher than adult males (Φ = 0.57), as in juveniles: females Φ = 0.27, males Φ = 0.13. Females were highly likely to remain in the same pool (adult: P = 0.85, juvenile: P = 0.88), while residency rates were lower for males (adult: P = 0.74, juvenile: P = 0.46). We combined survival, movement and life-histories to develop population viability models and test the impact of a range of life-history parameters. While using estimated apparent survival produced unviable populations (mean population growth rate r = -0.23, extinction within 20 years), considering residency rates to adjust survival estimates, indicated more stable populations (r = 0.004, p = 0.04 of 100-year extinction). Further sensitivity analyses highlighted adult female survival and overall success of dispersal as most affecting viability. Findings provide robust life-history and viability estimates for a difficult study species. These could support developing large-scale population dynamics models required to underpin a much needed national risk assessment for the platypus, already declining in parts of its current distribution.

Effect of storage temperature on survival and recovery of thermal and extrusion injured Escherichia coli K-12 in whey protein concentrate and corn meal.

PubMed

Ukuku, Dike O; Mukhopadhyay, Sudarsan; Onwulata, Charles

2013-01-01

Previously, we reported inactivation of Escherichia coli populations in corn product (CP) and whey protein product (WPP) extruded at different temperatures. However, information on the effect of storage temperatures on injured bacterial populations was not addressed. In this study, the effect of storage temperatures on the survival and recovery of thermal death time (TDT) disks and extrusion injured E. coli populations in CP and WPP was investigated. CP and WPP inoculated with E. coli bacteria at 7.8 log(10) CFU/g were conveyed separately into the extruder with a series 6300 digital type T-35 twin screw volumetric feeder set at a speed of 600 rpm and extruded at 35°C, 55°C, 75°C, and 95°C, or thermally treated with TDT disks submerged into water bath set at 35°C, 55°C, 75°C, and 95°C for 120 s. Populations of surviving bacteria including injured cells in all treated samples were determined immediately and every day for 5 days, and up to 10 days for untreated samples during storage at 5°C, 10°C, and 23°C. TDT disks treatment at 35°C and 55°C did not cause significant changes in the population of the surviving bacteria including injured populations. Extrusion treatment at 35°C and 55°C led to significant (p<0.05) reduction of E. coli populations in WPP as opposed to CP. The injured populations among the surviving E. coli cells in CP and WPP extruded at all temperatures tested were inactivated during storage. Population of E. coli inactivated in samples extruded at 75°C was significantly (p<0.05) different than 55°C during storage. Percent injured population could not be determined in samples extruded at 95°C due to absence of colony forming units on the agar plates. The results of this study showed that further inactivation of the injured populations occurred during storage at 5°C for 5 days suggesting the need for immediate storage of 75°C extruded CP and WPP at 5°C for at least 24 h to enhance their microbial safety.

Interacting stressors and the potential for adaptation in a changing world: responses of populations and individuals

PubMed Central

French, Susannah S.; Brodie, Edmund D.

2017-01-01

To accurately predict the impact of environmental change, it is necessary to assay effects of key interacting stressors on vulnerable organisms, and the potential resiliency of their populations. Yet, for the most part, these critical data are missing. We examined the effects of two common abiotic stressors predicted to interact with climate change, salinity and temperature, on the embryonic survival and development of a model freshwater vertebrate, the rough-skinned newt (Taricha granulosa) from different populations. We found that salinity and temperature significantly interacted to affect newt embryonic survival and development, with the negative effects of salinity most pronounced at temperature extremes. We also found significant variation among, and especially within, populations, with different females varying in the performance of their eggs at different salinity–temperature combinations, possibly providing the raw material for future natural selection. Our results highlight the complex nature of predicting responses to climate change in space and time, and provide critical data towards that aim. PMID:28680662

Using cure models for analyzing the influence of pathogens on salmon survival

USGS Publications Warehouse

Ray, Adam R; Perry, Russell W.; Som, Nicholas A.; Bartholomew, Jerri L

2014-01-01

Parasites and pathogens influence the size and stability of wildlife populations, yet many population models ignore the population-level effects of pathogens. Standard survival analysis methods (e.g., accelerated failure time models) are used to assess how survival rates are influenced by disease. However, they assume that each individual is equally susceptible and will eventually experience the event of interest; this assumption is not typically satisfied with regard to pathogens of wildlife populations. In contrast, mixture cure models, which comprise logistic regression and survival analysis components, allow for different covariates to be entered into each part of the model and provide better predictions of survival when a fraction of the population is expected to survive a disease outbreak. We fitted mixture cure models to the host–pathogen dynamics of Chinook Salmon Oncorhynchus tshawytscha and Coho Salmon O. kisutch and the myxozoan parasite Ceratomyxa shasta. Total parasite concentration, water temperature, and discharge were used as covariates to predict the observed parasite-induced mortality in juvenile salmonids collected as part of a long-term monitoring program in the Klamath River, California. The mixture cure models predicted the observed total mortality well, but some of the variability in observed mortality rates was not captured by the models. Parasite concentration and water temperature were positively associated with total mortality and the mortality rate of both Chinook Salmon and Coho Salmon. Discharge was positively associated with total mortality for both species but only affected the mortality rate for Coho Salmon. The mixture cure models provide insights into how daily survival rates change over time in Chinook Salmon and Coho Salmon after they become infected with C. shasta.

Hodgkin disease survival in Europe and the U.S.: prognostic significance of morphologic groups.

PubMed

Allemani, Claudia; Sant, Milena; De Angelis, Roberta; Marcos-Gragera, Rafael; Coebergh, Jan Willem

2006-07-15

The survival of patients with Hodgkin disease (HD) varies markedly across Europe and generally is shorter than the survival of patients in the U.S. To investigate these differences, the authors compared population-based HD survival in relation to morphologic type among populations in Europe and the U.S. The authors analyzed 6726 patients from 37 cancer registries that participated in EUROCARE-3 and 3442 patients from 9 U.S. Surveillance, Epidemiology, and End Results (SEER) registries. Patients were diagnosed during 1990 to 1994 and were followed for at least 5 years. The European registries were grouped into EUROCARE West, EUROCARE UK, and EUROCARE East. Morphologic groups were nodular sclerosis, mixed cellularity, lymphocyte depletion, lymphocyte predominance, and not otherwise specified (NOS). The influence of morphology on geographic differences in 5-year relative survival was explored by using multiple regression analysis. In the model that was adjusted by age, gender, and years since diagnosis, the relative excess risk (RER) of death was 0.93 (95% confidence interval [95% CI], 0.81-1.05) in EUROCARE West, 1.15 (95% CI, 1.04-1.28) in EUROCARE UK, and 1.39 (95% CI, 1.21-1.60) in EUROCARE East (compared with the SEER data). When morphology was included, EUROCARE UK and SEER no longer differed (RER, 1.06; 95% CI, 0.95-1.18). Morphology distribution varied markedly across Europe and much less in the U.S., with nodular sclerosis less common in Europe (45.9%) than the U.S. (61.7%). The RER data showed that patients who had lymphocyte depletion, NOS, and mixed cellularity had a significantly worse prognoses compared with patients who had nodular sclerosis, whereas patients who had lymphocyte predominance had the best prognosis. The current results provide population-based evidence that morphology strongly influences the prognosis of patients with HD. However differences in the morphologic case mix explains only some of the geographic variations observed in survival.

Differential adult survival at close seabird colonies: The importance of spatial foraging segregation and bycatch risk during the breeding season.

PubMed

Genovart, Meritxell; Bécares, Juan; Igual, José-Manuel; Martínez-Abraín, Alejandro; Escandell, Raul; Sánchez, Antonio; Rodríguez, Beneharo; Arcos, José M; Oro, Daniel

2018-03-01

Marine megafauna, including seabirds, are critically affected by fisheries bycatch. However, bycatch risk may differ on temporal and spatial scales due to the uneven distribution and effort of fleets operating different fishing gear, and to focal species distribution and foraging behavior. Scopoli's shearwater Calonectris diomedea is a long-lived seabird that experiences high bycatch rates in longline fisheries and strong population-level impacts due to this type of anthropogenic mortality. Analyzing a long-term dataset on individual monitoring, we compared adult survival (by means of multi-event capture-recapture models) among three close predator-free Mediterranean colonies of the species. Unexpectedly for a long-lived organism, adult survival varied among colonies. We explored potential causes of this differential survival by (1) measuring egg volume as a proxy of food availability and parental condition; (2) building a specific longline bycatch risk map for the species; and (3) assessing the distribution patterns of breeding birds from the three study colonies via GPS tracking. Egg volume was very similar between colonies over time, suggesting that environmental variability related to habitat foraging suitability was not the main cause of differential survival. On the other hand, differences in foraging movements among individuals from the three colonies expose them to differential mortality risk, which likely influenced the observed differences in adult survival. The overlap of information obtained by the generation of specific bycatch risk maps, the quantification of population demographic parameters, and the foraging spatial analysis should inform managers about differential sensitivity to the anthropogenic impact at mesoscale level and guide decisions depending on the spatial configuration of local populations. The approach would apply and should be considered in any species where foraging distribution is colony-specific and mortality risk varies spatially. © 2017 John Wiley & Sons Ltd.

Comparison of clinicopathologic features and survival between eastern and western population with esophageal squamous cell carcinoma.

PubMed

Zhang, Jie; Jiang, Yizhou; Wu, Chunxiao; Cai, Shuang; Wang, Rui; Zhen, Ying; Chen, Sufeng; Zhao, Kuaile; Huang, Yangle; Luketich, James; Chen, Haiquan

2015-10-01

Esophageal squamous cell carcinoma (ESCC) is the major histologic subtype of esophageal cancer, characterized by a high mortality rate and geographic differences in incidences. It is unknown whether there is difference between "eastern" ESCC and "western" ESCC. This study is attempted to demonstrate the hypothesis by comparing ESCC between Chinese residents and Caucasians living in the US. The data sources of this study are from United States SEER limited-use database and Shanghai Cancer Registries by Shanghai Municipal Center for Disease Control (SMCDC). Consecutive, non-selected patients with pathologically diagnosed ESCC, between January 1, 2002 and December 31, 2006, were included in this analysis. 1-year, 3-year and 5-year survival estimates were computed and compared between two populations. A Cox proportional hazards model was used to determine factors affecting survival differences. A total of 1,718 Chinese, 1,624 Caucasians ESCC patients with individual American Joint Commission on Cancer (AJCC) staging information were included in this study. The Caucasian group had a significantly higher proportion of female patients than Chinese (38.24% vs. 18.68% P<0.01). ESCC was diagnosed in Chinese patients at an earlier age and stage than Caucasians. Generally, Chinese patients had similar overall survival rate with Caucasian by both univariate and multivariate analysis. Overall survival was significantly worse only in male Caucasians compared to Chinese patients (median survival time, 12.4 vs. 14.5 months, P<0.01, respectively). ESCC from eastern and western countries might have some different features. These differences need to be taken into account for the management of ESCC patients in different ethnic groups.

Survival and growth of foodborne pathogens in minimally processed vegetables at 4 and 15 °C.

PubMed

Tian, Jun-Qi; Bae, Young-Min; Choi, Na-Young; Kang, Dong-Hyun; Heu, Sunggi; Lee, Sun-Young

2012-01-01

We conducted this study to investigate the survival and growth of pathogens on fresh vegetables stored at 4 and 15 °C. Vegetables (romaine lettuce, iceberg lettuce, perilla leaves, and sprouts) were inoculated with 4 pathogens (Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli O157:H7) and stored at 2 different temperatures for different periods of time (3, 6, 9, 12, and 15 d at 4 °C and 1, 2, 3, 5, and 7 d at 15 °C). Populations of the 4 pathogens tended to increase on all vegetables stored at 15 °C for 7 d. Populations of E. coli O157:H7 and S. Typhimurium increased significantly, by approximately 2 log₁₀ CFU/g, on loose and head lettuce stored at 15 °C for 1 d. No significant differences were observed in the growth of different pathogens on vegetables stored at 4 °C for 15 d. E. coli O157:H7 did not survive on sprouts stored at 15 or 4 °C. The survival and growth of food pathogens on fresh vegetables were very different depending on the pathogen type and storage temperature. Survivals and growth of pathogens on various vegetables at 4 and 15 °C were observed in this study. Survivals and growth of pathogens on vegetables were different depending on the pathogen type and storage temperature. Therefore, vegetables should be stored under refrigerated conditions (below 4 °C) prior to consumption. This recommendation may vary depending on the type of vegetable. © 2011 Institute of Food Technologists®

Population dynamics of ring-necked ducks in the Atlantic and Mississippi flyways

USGS Publications Warehouse

Conroy, M.J.

1982-01-01

Band-recovery data, harvest surveys, and spring and winter population surveys were used to estimate population parameters of ring-necked ducks (Aythya collaris). Mean annual survival rates of adult males (0.63 to 0.69) were higher (P < 0.05) than those of either adult females (0.48 to 0.58) or juveniles (0.31 to 0.41). Survival rates of winter-banded adult males were highest in the Mississippi Flyway (0.69), whereas those of females were highest in the Atlantic Flyway (0.58). Recovery rates varied little geographically, were similar for adult males and females, and were higher (P < 0.01) for juveniles. Survival rates of winter-banded adult males in the Mississippi Flyway were negatively correlated with annual harvest rate indices (r = -0.78, P < 0.01) and breeding population indices r = -0.68, P< 0.05). These results are contradictory, because the 1st correlation suggests an additive relationship between hunting and non-hunting mortality, whereas the 2nd suggests compensatory (density-dependent) mortality. Fall age-ratios of ring-necked ducks for 1961-80 were not significantly different between the Mississippi (1.29 young/adult) and the Atlantic (1.18 young/adult) Flyways. Estimated survival rates were used in conjunction with these age-ratios to project finite rates of increase at stable age distributions of approximately 1.0 for the Mississippi and the Atlantic Flyways. Mixing between the 2 Flyway populations and temporal variability in survival rates and age-ratios suggest a population with long-term stationarity but subject to large short-term fluctuations in growth rate. Breeding population surveys for 1960-80 corroborate these results, with breeding populations ranging from 200,000 to 800,000 ( = 500,000) but exhibiting no overall trends

Population differences in host immune factors may influence survival of Gunnison's prairie dogs (Cynomys Gunnisoni) during plague outbreaks

USGS Publications Warehouse

Busch, Joseph D.; Van Andel, Roger; Cordova, Jennifer; Colman, Rebecca E.; Keim, Paul; Rocke, Tonie E.; Leid, Jeff G.; Van Pelt, William E.; Wagner, David M.

2011-01-01

Over the past 40 yr, epizootics of plague (Yersinia pestis) in northern Arizona have reduced populations of the Gunnison’s prairie dog (Cynomys gunnisoni), with the exception of a large population found in the Aubrey Valley (AV). To examine potential mechanisms accounting for their survival, we collected prairie dog serum samples in 2005–2006 from AV and a neighboring population near Seligman (SE), Arizona. We quantified gene expression at 58 diverse immune proteins using a multiplexed enzyme-linked immunosorbent assay panel. We found a subset of proteins important in coagulation and inflammation (tissue factor [TF], calbindin [Cal], and thrombopoietin [TPO]) and T-cell responses (CD40L and CD40) that were present in AV at levels two to eight times greater than SE. These results suggest that AV and SE animals might differ in their ability to mount an immune response.

No inequalities in survival from colorectal cancer by education and socioeconomic deprivation - a population-based study in the North Region of Portugal, 2000-2002.

PubMed

Antunes, Luís; Mendonça, Denisa; Bento, Maria José; Rachet, Bernard

2016-08-05

Association between cancer survival and socioeconomic status has been reported in various countries but it has never been studied in Portugal. We aimed here to study the role of education and socioeconomic deprivation level on survival from colorectal cancer in the North Region of Portugal using a population-based cancer registry dataset. We analysed a cohort of patients aged 15-84 years, diagnosed with a colorectal cancer in the North Region of Portugal between 2000 and 2002. Education and socioeconomic deprivation level was assigned to each patient based on their area of residence. We measured socioeconomic deprivation using the recently developed European Deprivation Index. Net survival was estimated using Pohar-Perme estimator and age-adjusted excess hazard ratios were estimated using parametric flexible models. Since no deprivation-specific life tables were available, we performed a sensitivity analysis to test the robustness of the results to life tables adjusted for education and socioeconomic deprivation level. A total of 4,105 cases were included in the analysis. In male patients (56.3 %), a pattern of worse 5- and 10-year net survival in the less educated (survival gap between extreme education groups: -7 % and -10 % at 5 and 10 years, respectively) and more deprived groups (survival gap between extreme EDI groups: -5 % both at 5 and 10 years) was observed when using general life tables. No such clear pattern was found among female patients. In both sexes, when likely differences in background mortality by education or deprivation were accounted for in the sensitivity analysis, any differences in net survival between education or deprivation groups vanished. Our study shows that observed differences in survival by education and EDI level are most likely attributable to inequalities in background survival. Also, it confirms the importance of using the relevant life tables and of performing sensitivity analysis when evaluating socioeconomic inequalities in cancer survival. Comparison studies of different healthcare systems organization should be performed to better understand its influence on cancer survival inequalities.

Compensatory mortality in mule deer populations: Final technical report, January 1, 1985--December 31, 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, G.C.

1989-03-01

The hypothesis of compensatory mortality is critical to understanding population dynamics of wildlife species. This knowledge is vital regardless of whether populations are managed for recreational hunting or habitats are altered via energy development projects. This research tested for compensatory mortality in the juvenile (fawn) portion of a mule deer population. Two experimental manipulations were used employing radio-collared deer. In this study, /approximately/20% of the population was moved from a treatment area and fawn survival rates compared to those on the control area. In the pasture study, deer were stocked in pastures at 3 densities of 44, 89, and 139more » deer/km/sup 2/. Lowering of density in the field portion of the study did not appear to affect fawn survival. This is attributed to not removing enough animals for existing range conditions that have been imparted by high deer densities during the last 3 decades. Also, the effect of removal was tempered by an increase in yearling males brought about by antler-point restrictions during the harvest. Deer removed from the treatment area were used to stock 3 large pastures at low, medium, and high densities of 44, 89, and 139 deer/km/sup 2/, respectively. Fawn survival was significantly different between densities (P < 0.001), with the low density pasture showing the highest survival and the high density pasture showing the lowest survival. The main cause of death was starvation suggesting that food supplies were limiting. A strong compensatory mortality process is operating in this mule deer population as evidenced by the pasture data. We did not detect this process in the field portion of the study because the removal of /approximately/20% of the population was insufficient to allow an immediate improvement in fawn nutrition. The density-dependent survival response in the controlled pasture study demonstrated that compensatory mortality is operating in this population. 57 refs., 7 figs., 6 tabs.« less

Climate variability drives population cycling and synchrony

Treesearch

Lars Y. Pomara; Benjamin Zuckerberg

2017-01-01

Aim There is mounting concern that climate change will lead to the collapse of cyclic population dynamics, yet the influence of climate variability on population cycling remains poorly understood. We hypothesized that variability in survival and fecundity, driven by climate variability at different points in the life cycle, scales up from...

Gender- and ethnicity-specific survival trends of oral cavity and oropharyngeal cancers in British Columbia.

PubMed

Auluck, Ajit; Hislop, Greg; Bajdik, Chris; Hay, John; Bottorff, Joan L; Zhang, Lewei; Rosin, Miriam P

2012-12-01

A shift in etiology of oral cancers has been associated with a rise in incidence for oropharyngeal cancers (OPC) and decrease for oral cavity cancers (OCC); however, there is limited information about population-based survival trends. We report epidemiological transitions in survival for both OPC and OCC from a population-based cancer registry, focusing upon gender and ethnic differences. All primary oral cancers diagnosed between 1980 and 2005 were identified from the British Columbia Cancer Registry and regrouped into OPC and OCC by topographical subsites, time periods (1980-1993 and 1994-2005), stage at diagnosis, and ethnicity. Cases were then followed up to December 2009. Using gender-based analysis, actuarial life tables were used to calculate survival rates, which were compared using Kaplan-Meier curves and log-rank tests. For OPC, survival improved, significant for tonsil and base of tongue in men and marginally significant at base of tongue in women. This improvement occurred in spite of an increase in late-stage diagnosis for OPC in both genders. Interestingly, there was no difference in survival for early- and late-stage disease for OPC in men. For OCC, there was a decrease in survival for floor of mouth cancers in both genders although significant in women only. South Asians had the poorest survival for OCC in both genders. Survival for OPC improved, more dramatically in men than women, in spite of late-stage diagnosis and increasing nodal involvement. Given the poor survival rates and need for early detection, targeted OCC screening programs are required for South Asians.

A model of northern pintail productivity and population growth rate

USGS Publications Warehouse

Flint, Paul L.; Grand, James B.; Rockwell, Robert F.

1998-01-01

Our objective was to synthesize individual components of reproductive ecology into a single estimate of productivity and to assess the relative effects of survival and productivity on population dynamics. We used information on nesting ecology, renesting potential, and duckling survival of northern pintails (Anas acuta) collected on the Yukon-Kuskokwim Delta (Y-K Delta), Alaska, 1991-95, to model the number of ducklings produced under a range of nest success and duckling survival probabilities. Using average values of 25% nest success, 11% duckling survival, and 56% renesting probability from our study population, we calculated that all young in our population were produced by 13% of the breeding females, and that early-nesting females produced more young than later-nesting females. Further, we calculated, on average, that each female produced only 0.16 young females/nesting season. We combined these results with estimates of first-year and adult survival to examine the growth rate (X) of the population and the relative contributions of these demographic parameters to that growth rate. Contrary to aerial survey data, the population projection model suggests our study population is declining rapidly (X = 0.6969). The relative effects on population growth rate were 0.1175 for reproductive success, 0.1175 for first-year survival, and 0.8825 for adult survival. Adult survival had the greatest influence on X for our population, and this conclusion was robust over a range of survival and productivity estimates. Given published estimates of annual survival for adult females (61%), our model suggested nest success and duckling survival need to increase to approximately 40% to achieve population stability. We discuss reasons for the apparent discrepancy in population trends between our model and aerial surveys in terms of bias in productivity and survival estimates.

Adult survival and population growth rate in Colorado big brown bats (Eptesicus fuscus)

USGS Publications Warehouse

O'Shea, T.J.; Ellison, L.E.; Stanley, T.R.

2011-01-01

We studied adult survival and population growth at multiple maternity colonies of big brown bats (Eptesicus fuscus) in Fort Collins, Colorado. We investigated hypotheses about survival using information-theoretic methods and mark-recapture analyses based on passive detection of adult females tagged with passive integrated transponders. We constructed a 3-stage life-history matrix model to estimate population growth rate (??) and assessed the relative importance of adult survival and other life-history parameters to population growth through elasticity and sensitivity analysis. Annual adult survival at 5 maternity colonies monitored from 2001 to 2005 was estimated at 0.79 (95% confidence interval [95% CI] = 0.77-0.82). Adult survival varied by year and roost, with low survival during an extreme drought year, a finding with negative implications for bat populations because of the likelihood of increasing drought in western North America due to global climate change. Adult survival during winter was higher than in summer, and mean life expectancies calculated from survival estimates were lower than maximum longevity records. We modeled adult survival with recruitment parameter estimates from the same population. The study population was growing (?? = 1.096; 95% CI = 1.057-1.135). Adult survival was the most important demographic parameter for population growth. Growth clearly had the highest elasticity to adult survival, followed by juvenile survival and adult fecundity (approximately equivalent in rank). Elasticity was lowest for fecundity of yearlings. The relative importances of the various life-history parameters for population growth rate are similar to those of large mammals. ?? 2011 American Society of Mammalogists.

Development of a five-year mortality model in systemic sclerosis patients by different analytical approaches.

PubMed

Beretta, Lorenzo; Santaniello, Alessandro; Cappiello, Francesca; Chawla, Nitesh V; Vonk, Madelon C; Carreira, Patricia E; Allanore, Yannick; Popa-Diaconu, D A; Cossu, Marta; Bertolotti, Francesca; Ferraccioli, Gianfranco; Mazzone, Antonino; Scorza, Raffaella

2010-01-01

Systemic sclerosis (SSc) is a multiorgan disease with high mortality rates. Several clinical features have been associated with poor survival in different populations of SSc patients, but no clear and reproducible prognostic model to assess individual survival prediction in scleroderma patients has ever been developed. We used Cox regression and three data mining-based classifiers (Naïve Bayes Classifier [NBC], Random Forests [RND-F] and logistic regression [Log-Reg]) to develop a robust and reproducible 5-year prognostic model. All the models were built and internally validated by means of 5-fold cross-validation on a population of 558 Italian SSc patients. Their predictive ability and capability of generalisation was then tested on an independent population of 356 patients recruited from 5 external centres and finally compared to the predictions made by two SSc domain experts on the same population. The NBC outperformed the Cox-based classifier and the other data mining algorithms after internal cross-validation (area under receiving operator characteristic curve, AUROC: NBC=0.759; RND-F=0.736; Log-Reg=0.754 and Cox= 0.724). The NBC had also a remarkable and better trade-off between sensitivity and specificity (e.g. Balanced accuracy, BA) than the Cox-based classifier, when tested on an independent population of SSc patients (BA: NBC=0.769, Cox=0.622). The NBC was also superior to domain experts in predicting 5-year survival in this population (AUROC=0.829 vs. AUROC=0.788 and BA=0.769 vs. BA=0.67). We provide a model to make consistent 5-year prognostic predictions in SSc patients. Its internal validity, as well as capability of generalisation and reduced uncertainty compared to human experts support its use at bedside. Available at: http://www.nd.edu/~nchawla/survival.xls.

Evaluation of mist-netting, nest-searching and other methods for monitoring demographic processes in landbird populations

Treesearch

Nadav Nur; Geoffrey R. Geupel

1993-01-01

Demographic processes (reproductive success, survival of young and adults, recruitment of young into the breeding population) are critical to monitoring and managing landbird populations. We discuss different techniques that have been used to monitor these demographic processes in landbird populations, focusing on constant-effort mist-netting (CEM). We assess whether...

Genetic variation in blue spruce: A test of populations in Nebraska

Treesearch

David F. Van Haverbeke

1984-01-01

Analyses of 43 blue spruce populations at age 12 (9 years in the field) revealed significant differences among populations for survival, height, vigor, crown diameter, frost injury, and foliage color. Use of regions increases the probability of locating better seeds sources, but high variability among individual populations within regions limits their value in...

Demographic drivers of a refugee species: Large‐scale experiments guide strategies for reintroductions of hirola

USGS Publications Warehouse

Ali, Abdullahi H.; Kauffman, Matthew J.; Amin, Rajan; Kibara, Amos; King, Juliet; Mallon, David P.; Musyoki, Charles; Goheen, Jacob R.

2018-01-01

Effective reintroduction strategies require accurate estimates of vital rates and the factors that influence them. The hirola (Beatragus hunteri) is the rarest antelope on Earth, with a global population size of <500 individuals restricted to the Kenya–Somali border. We estimated vital rates of hirola populations exposed to varying levels of predation and rangeland quality from 2012 to 2015, and then built population matrices to estimate the finite rate of population change (λ) and demographic sensitivities. Mean survival for all age classes and population growth was highest in the low‐predation–high‐rangeland‐quality setting (λ = 1.08 ± 0.03 [mean ± SE]), and lowest in the high‐predation–low‐rangeland‐quality setting (λ = 0.70 ± 0.22). Retrospective demographic analyses revealed that increased fecundity (the number of female calves born to adult females annually) and female calf survival were responsible for higher population growth where large carnivores were absent. In contrast, variation in adult female survival was the primary contributor to differences in population growth attributable to rangeland quality. Our analyses suggest that hirola demography is driven by a combination of top‐down (predation) and bottom‐up (rangeland quality) forces, with populations in the contemporary geographic range impacted both by declining rangeland quality and predation. To enhance the chances of successful reintroductions, conservationists can consider rangeland restoration to boost both the survival and fecundity of adult females within the hirola's historical range.

[Effects of pomegranate varieties on the development and fecundity of Assara inouei Yamanaka (Lepidoptera: Pyralidae)].

PubMed

He, Chao; Shen, Deng Rong; Yin, Li Hong; Li, Xi Liang; He, Jian Cai; Yuan, Sheng Yong; Tian, Xue Jun

2017-03-18

Assara inouei Yanmanaka is an important pest of pomegranate fruits in Yunnan Province. To examine the effects of different pomegranate varieties on the development and reproduction of A. inouei, the biological characteristics, such as the developmental duration, the survival rate and reproduction of this pest feeding on five pomegranate varieties including Tianlvzi, Houpitianshazi, Tianguangyan, Suanlvzi and Suanshazi were observed respectively, and the life table parameters were established under the laboratory conditions of (25±1) ℃, RH (70±10)% and a photoperiod of 15 L:9 D. The results showed that there were no significant differences in the egg stage, larval stage, pupal stage, the longevity of male adults, generation duration form egg to adult and egg hatch rate among the five varieties. There were significant differences in the pre-pupal stage, the longevity of female adults, larval survival, pupation, eclosion and total survival rates, the number of eggs laid per female as well as male and female pupal mass among the five varieties, and all of which except the larval survival were higher on Suanlvzi, followed by Houpitianshazi, but there was no significant difference between these two varieties. The results of life table showed the net reproduction rate, the intrinsic rate of increase and finite rate of increase of the Suanlvzi population were the highest. There were no significant differences in the mean generation time among the five varieties, but significant difference was observed in the population doubling time, which was the shortest on Suanlvzi population. The development and reproduction of A. inouei were better on the Suanlvzi and Houpitianshazi among the five varieties.

Population growth, fecundity, and survivorship in recovering populations of bighorn sheep

USGS Publications Warehouse

Singer, F.J.; Williams, E.; Miller, M.W.; Zeigenfuss, L.C.

2000-01-01

The single greatest obstacle to the restoration of large, healthy, populations of bighorn sheep (Ovis canadensis) in the western United States is epizootic outbreaks of bronchopneumonia that may kill 20–100% of the animals in populations. Although the species is capable of rapid initial growth rates following restoration into new habitat (λ = 1.23–1.30 have been observed), these rates of increase are typical only a few years following the release of a population, and then most populations either decline to extirpation or remnant status (<30 animals) or remain at <100 individuals. We studied the fecundity and survivorship of three increasing, and three declining and suspected diseased, populations of bighorn sheep (the latter were subjected to outbreaks of bronchopneumonia) located in or near several large national parks in the western United States from 1991 to 1996. Titers verified both population categories were exposed to the bacteria Pasteurella haemolytica serotypes 3; 4; and 3, 4, 10; Moraxella sp., and parainfluenza-3 and bluetongue (BT) viruses. Pregnancy rates of adult ewes were not different in increasing or decreasing populations (pooled rate = 0.93; p = 0.57), but pregnancy rates of yearlings were lower (0.00 for decreasing vs. 0.33 for increasing populations), initial production of lambs and annual recruitment of lambs was lower (0.14, decreasing vs. 0.66, p < 0.05). Adult survival was lower during the first year of an epizootic, 0.62, in one population, but recovered to 0.85 by the second and subsequent years. Survival of adult rams was variable in diseased populations; in two populations rams appeared to be disproportionately impacted, but in a third population rams survived better during the epizootic. In all the increasing park (unhunted) populations, adult ram survival (0.94 ± 0.01) was higher than adult ewe survival (0.89 ± 0.02) (p = 0.10), in contrast to published information from hunted populations where ram survival was lower. Removal of about 20% of one population for restorations severely impacted one declining population. Removals of 12–20% appeared to be excessive and were not readily compensated for in the Canyonlands National Park desert bighorn population. Disease was a significant limiting factor to restoration of bighorn sheep in the study areas; six of 11 total recovering populations we monitored closely were negatively influenced by apparent disease at some time during our observations.

Dying like rabbits: general determinants of spatio-temporal variability in survival.

PubMed

Tablado, Zulima; Revilla, Eloy; Palomares, Francisco

2012-01-01

1. Identifying general patterns of how and why survival rates vary across space and time is necessary to truly understand population dynamics of a species. However, this is not an easy task given the complexity and interactions of processes involved, and the interpopulation differences in main survival determinants. 2. Here, using European rabbits (Oryctolagus cuniculus) as a model and information from local studies, we investigated whether we could make inferences about trends and drivers of survival of a species that are generalizable to large spatio-temporal scales. To do this, we first focused on overall survival and then examined cause-specific mortalities, mainly predation and diseases, which may lead to those patterns. 3. Our results show that within the large-scale variability in rabbit survival, there exist general patterns that are explained by the integration of factors previously known to be important at the local level (i.e. age, climate, diseases, predation or density dependence). We found that both inter- and intrastudy survival rates increased in magnitude and decreased in variability as rabbits grow old, although this tendency was less pronounced in populations with epidemic diseases. Some causes leading to these higher mortalities in young rabbits could be the stronger effect of rainfall at those ages, as well as, other death sources like malnutrition or infanticide. 4. Predation is also greater for newborns and juveniles, especially in population without diseases. Apart from the effect of diseases, predation patterns also depended on factors, such as, density, season, and type and density of predators. Finally, we observed that infectious diseases also showed general relationships with climate, breeding (i.e. new susceptible rabbits) and age, although the association type varied between myxomatosis and rabbit haemorrhagic disease. 5. In conclusion, large-scale patterns of spatio-temporal variability in rabbit survival emerge from the combination of different factors that interrelate both directly and through density dependence. This highlights the importance of performing more comprehensive studies to reveal combined effects and complex relationships that help us to better understand the mechanisms underlying population dynamics. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.

Functional analysis of Normalized Difference Vegetation Index curves reveals overwinter mule deer survival is driven by both spring and autumn phenology

PubMed Central

Hurley, Mark A.; Hebblewhite, Mark; Gaillard, Jean-Michel; Dray, Stéphane; Taylor, Kyle A.; Smith, W. K.; Zager, Pete; Bonenfant, Christophe

2014-01-01

Large herbivore populations respond strongly to remotely sensed measures of primary productivity. Whereas most studies in seasonal environments have focused on the effects of spring plant phenology on juvenile survival, recent studies demonstrated that autumn nutrition also plays a crucial role. We tested for both direct and indirect (through body mass) effects of spring and autumn phenology on winter survival of 2315 mule deer fawns across a wide range of environmental conditions in Idaho, USA. We first performed a functional analysis that identified spring and autumn as the key periods for structuring the among-population and among-year variation of primary production (approximated from 1 km Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index (NDVI)) along the growing season. A path analysis showed that early winter precipitation and direct and indirect effects of spring and autumn NDVI functional components accounted for 45% of observed variation in overwinter survival. The effect size of autumn phenology on body mass was about twice that of spring phenology, while direct effects of phenology on survival were similar between spring and autumn. We demonstrate that the effects of plant phenology vary across ecosystems, and that in semi-arid systems, autumn may be more important than spring for overwinter survival. PMID:24733951

Size-sex variation in survival rates and abundance of pig frogs, Rana grylio, in northern Florida wetlands

USGS Publications Warehouse

Wood, K.V.; Nichols, J.D.; Percival, H.F.; Hines, J.E.

1998-01-01

During 1991-1993, we conducted capture-recapture studies on pig frogs, Rana grylio, in seven study locations in northcentral Florida. Resulting data were used to test hypotheses about variation in survival probability over different size-sex classes of pig frogs. We developed multistate capture-recapture models for the resulting data and used them to estimate survival rates and frog abundance. Tests provided strong evidence of survival differences among size-sex classes, with adult females showing the highest survival probabilities. Adult males and juvenile frogs had lower survival rates that were similar to each other. Adult females were more abundant than adult males in most locations at most sampling occasions. We recommended probabilistic capture-recapture models in general, and multistate models in particular, for robust estimation of demographic parameters in amphibian populations.

Survival rate variation with different histological subtypes of poor prognostic male anal squamous cell carcinoma: a population-based study.

PubMed

Wan, Zihao; Huang, Zhihao; Vikash, Vikash; Rai, Kelash; Vikash, Sindhu; Chen, Liaobin; Li, Jingfeng

2017-10-13

The prognosis of male anal squamous cell carcinoma (MASCC) and female anal squamous cell carcinoma (FASCC) is variable. The influence of tumor subtype on the survival rate and gender is poorly known. Our study is the largest population-based study and aims to outline the difference in survival between MASCC and FASCC patients. A retrospective population-based study was performed to compare the disease-specific mortalities (DSMs) between genders related to the tumor subtypes. The Surveillance, Epidemiology, and End Results (SEER) program database was employed to obtain the data from January 1988 to December 2014. A total of 4,516, (3,249 males and 1,267 females), patients with anal squamous cell carcinomas (ASCC) were investigated. The 5-year DSMs were 24.18% and 18.08% for men and women, respectively. The univariate analysis of the male basaloid squamous cell carcinoma (BSCC) and cloacogenic carcinoma (CC) patients demonstrated higher DSMs (P <0.001). Moreover, in the multivariate analysis, BSCC and CC were associated with soaring DSMs in male patients (P < 0.05). In the cohort of BSCC and CC patients, male patients demonstrated a considerable decrease in survival rate compared to females. A more precise classification of ASCC and individualized management for MASCC are warranted.

Survival and harvest-related mortality of white-tailed deer in Massachusetts

USGS Publications Warehouse

Mcdonald, John E.; DeStefano, Stephen; Gaughan, Christopher; Mayer, Michael; Woytek, William A.; Christensen, Sonja; Fuller, Todd K.

2011-01-01

We monitored 142 radiocollared adult (≥1.0 yr old) white-tailed deer (Odocoileus virginianus) in 3 study areas of Massachusetts, USA, to estimate annual survival and mortality due to legal hunting. We then applied these rates to deer harvest information to estimate deer population trends over time, and compared these to trends derived solely from harvest data estimates. Estimated adult female survival rates were similar (0.82–0.86), and uniformly high, across 3 management zones in Massachusetts that differed in landscape composition, human density, and harvest regulations. Legal hunting accounted for 16–29% of all adult female mortality. Estimated adult male survival rates varied from 0.55 to 0.79, and legal hunting accounted for 40–75% of all mortality. Use of composite hunting mortality rates produced realistic estimates for adult deer populations in 2 zones, but not for the third, where estimation was hindered by regulatory restrictions on antlerless deer harvest. In addition, the population estimates we calculated were generally higher than those derived from population reconstruction, likely due to relatively low harvest pressure. Legal harvest may not be the dominant form of deer mortality in developed landscapes; thus, estimates of populations or trends that rely solely on harvest data will likely be underestimates.

Effects of Clonal Reproduction on Evolutionary Lag and Evolutionary Rescue.

PubMed

Orive, Maria E; Barfield, Michael; Fernandez, Carlos; Holt, Robert D

2017-10-01

Evolutionary lag-the difference between mean and optimal phenotype in the current environment-is of keen interest in light of rapid environmental change. Many ecologically important organisms have life histories that include stage structure and both sexual and clonal reproduction, yet how stage structure and clonality interplay to govern a population's rate of evolution and evolutionary lag is unknown. Effects of clonal reproduction on mean phenotype partition into two portions: one that is phenotype dependent, and another that is genotype dependent. This partitioning is governed by the association between the nonadditive genetic plus random environmental component of phenotype of clonal offspring and their parents. While clonality slows phenotypic evolution toward an optimum, it can dramatically increase population survival after a sudden step change in optimal phenotype. Increased adult survival slows phenotypic evolution but facilitates population survival after a step change; this positive effect can, however, be lost given survival-fecundity trade-offs. Simulations indicate that the benefits of increased clonality under environmental change greatly depend on the nature of that change: increasing population persistence under a step change while decreasing population persistence under a continuous linear change requiring de novo variation. The impact of clonality on the probability of persistence for species in a changing world is thus inexorably linked to the temporal texture of the change they experience.

Survival of American Black Ducks radiomarked in Quebec, Nova Scotia and Vermont

USGS Publications Warehouse

Longcore, J.R.; McAuley, D.G.; Clugston, D.A.; Bunck, C.M.; Giroux, J.-F.; Ouellet, C.; Parker, G.R.; Dupuis, P.; Stotts, D.B.; Goldsberry, J.R.

2000-01-01

We monitored survival of 397 radiomarked juvenile American black ducks (Anas rubripes) distributed among Les Escoumins (n = 75) and Kamouraska, Quebec (n = 84), Amherst Point, Nova Scotia (n = 89), and a site on the Vermont-Quebec border (n = 149) during autumn 1990 and 1991. Eighty-six percent (215 of 250) of all confirmed mortalities during the study was from hunting; 72% of marked ducks were shot and retrieved and 14% were shot and unretrieved. We tested for differences in survival in relation to sex, body mass, year (1990-91, 1991-92), and among the 4 locations for each of 2 monitoring periods (early, EMP; late, LMP). With data from the EMP for Vermont-Quebec in 1990 and 1991, Les Escoumins in 1990, and Amherst Point in 1991, survival of hatching-year (HY) males and females did not differ (P = 0.357). For sexes combined for the EMP, survival of ducks was greater in 1991 than 1990 (P = 0.086), and differed among locations (P = 0.013). Survival (years combined) was greater at Amherst Point than at Kamouraska (P = 0.003) and Vermont-Quebec (P = 0.002) during the EMP. The highest survival rate at Amherst Point (0.545 ? 0.056 [SE]) was associated with the latest date (8 Oct) of season opening; the lowest survival rate (0.395 ? 0.043) was at the Vermont-Quebec border, where hunter numbers and activity were greatest. For the LMP, no interaction between years and locations was detected (P = 0.942), and no differences in survival existed between years (P = 0.102) and among locations (P = 0.349). No association was detected between body mass at capture and survival of combined males and females during the EMP (P = 0.572) or during the LMP (P = 0.965). When we censored hunting losses for combined years for each period, EMP or LMP, all survival estimates exceeded 0.800 (0.809-0.965). These data emphasize need for an improved harvest strategy for American black ducks in North America to allow for increases in breeding populations to achieve population goals.

Survival in patients with acute myeloblastic leukemia in Germany and the United States: Major differences in survival in young adults.

PubMed

Pulte, Dianne; Jansen, Lina; Castro, Felipe A; Krilaviciute, Agne; Katalinic, Alexander; Barnes, Benjamin; Ressing, Meike; Holleczek, Bernd; Luttmann, Sabine; Brenner, Hermann

2016-09-15

Previous epidemiologic studies on AML have been limited by the rarity of the disease. Here, we present population level data on survival of patients with AML in Germany and the United States (US). Data were extracted from 11 population-based cancer registries in Germany and the Surveillance, Epidemiology, and End Results (SEER13) database in the US. Patients diagnosed with AML in 1997-2011 were included. Period analysis was used to estimate 5-year relative survival (RS) and trends in survival in the early 21st century. Overall 5-year age-adjusted RS for patients with AML in 2007-2011 was greater in Germany than in the US at 22.8% and 18.8%, respectively. Five-year RS was higher in Germany than in the US at all ages, with particularly large differences at ages 15-24 for whom 5-year RS was 64.3% in Germany and 55.0% in the US and 35-44, with 5-year RS estimates of 61.8% in Germany and 46.6% in the US. Most of the difference in 5-year RS was due to higher 1-year RS, with overall 1-year RS estimates of 47.0% in Germany and 38.5% in the US. A small increase in RS was observed between 2003-2005 and 2009-2011 in both countries, but no increase in survival was observed in either country for ages 75+. To our knowledge, this is the first detailed description of AML survival in Germany. Comparison to the US suggests that further analysis into risk factors for poor outcomes in AML in the US may be useful in improving survival. © 2016 UICC.

Extensive variation, but not local adaptation in an Australian alpine daisy.

PubMed

Hirst, Megan J; Sexton, Jason P; Hoffmann, Ary A

2016-08-01

Alpine plants often occupy diverse habitats within a similar elevation range, but most research on local adaptation in these plants has focused on elevation gradients. In testing for habitat-related local adaptation, local effects on seed quality and initial plant growth should be considered in designs that encompass multiple populations and habitats. We tested for local adaptation across alpine habitats in a morphologically variable daisy species, Brachyscome decipiens, in the Bogong High Plains in Victoria, Australia. We collected seed from different habitats, controlled for maternal effects through initial seed size estimates, and characterized seedling survival and growth in a field transplant experiment. We found little evidence for local adaptation for survival or plant size, based on three adaptation measures: Home versus Away, Local versus Foreign, and Sympatric versus Allopatric (SA). The SA measure controlled for planting site and population (site-of-origin) effects. There were significant differences due to site-of-origin and planting site effects. An important confounding factor was the size of plants directly after transplantation of seedlings, which had a large impact on subsequent seedling survival and growth. Initial differences in plant width and height influenced subsequent survival across the growing season but in opposing directions: wide plants had higher survival, but tall plants had lower survival. In an additional controlled garden experiment at Cranbourne Royal Botanic Gardens, site-of-origin effects detected in the field experiments disappeared under more benign homogeneous conditions. Although B. decipiens from different source areas varied significantly when grown across a range of alpine habitats, these differences did not translate into a local or habitat-related fitness advantage. This lack of local advantage may signal weak past selection, and/or weak adaptive transgeneration (plasticity) effects.

Parallel and costly changes to cellular immunity underlie the evolution of parasitoid resistance in three Drosophila species.

PubMed

McGonigle, John E; Leitão, Alexandre B; Ommeslag, Sarah; Smith, Sophie; Day, Jonathan P; Jiggins, Francis M

2017-10-01

A priority for biomedical research is to understand the causes of variation in susceptibility to infection. To investigate genetic variation in a model system, we used flies collected from single populations of three different species of Drosophila and artificially selected them for resistance to the parasitoid wasp Leptopilina boulardi, and found that survival rates increased 3 to 30 fold within 6 generations. Resistance in all three species involves a large increase in the number of the circulating hemocytes that kill parasitoids. However, the different species achieve this in different ways, with D. melanogaster moving sessile hemocytes into circulation while the other species simply produce more cells. Therefore, the convergent evolution of the immune phenotype has different developmental bases. These changes are costly, as resistant populations of all three species had greatly reduced larval survival. In all three species resistance is only costly when food is in short supply, and resistance was rapidly lost from D. melanogaster populations when food is restricted. Furthermore, evolving resistance to L. boulardi resulted in cross-resistance against other parasitoids. Therefore, whether a population evolves resistance will depend on ecological conditions including food availability and the presence of different parasite species.

Parallel and costly changes to cellular immunity underlie the evolution of parasitoid resistance in three Drosophila species

PubMed Central

Ommeslag, Sarah; Smith, Sophie; Day, Jonathan P.

2017-01-01

A priority for biomedical research is to understand the causes of variation in susceptibility to infection. To investigate genetic variation in a model system, we used flies collected from single populations of three different species of Drosophila and artificially selected them for resistance to the parasitoid wasp Leptopilina boulardi, and found that survival rates increased 3 to 30 fold within 6 generations. Resistance in all three species involves a large increase in the number of the circulating hemocytes that kill parasitoids. However, the different species achieve this in different ways, with D. melanogaster moving sessile hemocytes into circulation while the other species simply produce more cells. Therefore, the convergent evolution of the immune phenotype has different developmental bases. These changes are costly, as resistant populations of all three species had greatly reduced larval survival. In all three species resistance is only costly when food is in short supply, and resistance was rapidly lost from D. melanogaster populations when food is restricted. Furthermore, evolving resistance to L. boulardi resulted in cross-resistance against other parasitoids. Therefore, whether a population evolves resistance will depend on ecological conditions including food availability and the presence of different parasite species. PMID:29049362

Survival rates among Seventh Day Adventists compared with the general population in Poland.

PubMed

Jedrychowski, W; Tobiasz-Adamczyk, B; Olma, A; Gradzikiewicz, P

1985-01-01

The purpose of the work was to test the hypothesis that the survival rate is higher among the Seventh Day Adventists (SDA) than in the general population of Poland, because of the strictly respected customs adhered to by members of this church community, such as abstinence from smoking and from alcohol. The data on life expectancy in the SDA community covered a total of 236 members of this denomination in Kraków (86 males and 150 females). The survival probability rates were estimated by the life table method, for both men and women separately, and were subsequently compared with the corresponding parameters of the Polish Life Tables. Over a period of 10 years, in which these data were studied, there were 11 deaths in males and 24 deaths in females. Mean age at death was 71.9 years among men and 75.1 among women. The survival curves traced over the age groups of both sexes of SDA members were fairly similar, but they were markedly higher than in the general population of Poland. In the general population the survival rates for people over 40 years old were higher in females than in males, whereas no corresponding sex differences in rates concerning SDA members were observed. The greater benefit in life expectancy is gained in the SDA group in comparison with men in the general population. This is attributable to their abstinence from very harmful habits, otherwise more widespread in this sex group.

Emergence and Evolution of Cooperation Under Resource Pressure

PubMed Central

Pereda, María; Zurro, Débora; Santos, José I.; Briz i Godino, Ivan; Álvarez, Myrian; Caro, Jorge; Galán, José M.

2017-01-01

We study the influence that resource availability has on cooperation in the context of hunter-gatherer societies. This paper proposes a model based on archaeological and ethnographic research on resource stress episodes, which exposes three different cooperative regimes according to the relationship between resource availability in the environment and population size. The most interesting regime represents moderate survival stress in which individuals coordinate in an evolutionary way to increase the probabilities of survival and reduce the risk of failing to meet the minimum needs for survival. Populations self-organise in an indirect reciprocity system in which the norm that emerges is to share the part of the resource that is not strictly necessary for survival, thereby collectively lowering the chances of starving. Our findings shed further light on the emergence and evolution of cooperation in hunter-gatherer societies. PMID:28362000

Emergence and Evolution of Cooperation Under Resource Pressure.

PubMed

Pereda, María; Zurro, Débora; Santos, José I; Briz I Godino, Ivan; Álvarez, Myrian; Caro, Jorge; Galán, José M

2017-03-31

We study the influence that resource availability has on cooperation in the context of hunter-gatherer societies. This paper proposes a model based on archaeological and ethnographic research on resource stress episodes, which exposes three different cooperative regimes according to the relationship between resource availability in the environment and population size. The most interesting regime represents moderate survival stress in which individuals coordinate in an evolutionary way to increase the probabilities of survival and reduce the risk of failing to meet the minimum needs for survival. Populations self-organise in an indirect reciprocity system in which the norm that emerges is to share the part of the resource that is not strictly necessary for survival, thereby collectively lowering the chances of starving. Our findings shed further light on the emergence and evolution of cooperation in hunter-gatherer societies.

Emergence and Evolution of Cooperation Under Resource Pressure

NASA Astrophysics Data System (ADS)

Pereda, María; Zurro, Débora; Santos, José I.; Briz I Godino, Ivan; Álvarez, Myrian; Caro, Jorge; Galán, José M.

2017-03-01

We study the influence that resource availability has on cooperation in the context of hunter-gatherer societies. This paper proposes a model based on archaeological and ethnographic research on resource stress episodes, which exposes three different cooperative regimes according to the relationship between resource availability in the environment and population size. The most interesting regime represents moderate survival stress in which individuals coordinate in an evolutionary way to increase the probabilities of survival and reduce the risk of failing to meet the minimum needs for survival. Populations self-organise in an indirect reciprocity system in which the norm that emerges is to share the part of the resource that is not strictly necessary for survival, thereby collectively lowering the chances of starving. Our findings shed further light on the emergence and evolution of cooperation in hunter-gatherer societies.

Survival of radio-implanted drymarchon couperi (Eastern Indigo Snake) in relation to body size and sex

USGS Publications Warehouse

Hyslop, N.L.; Meyers, J.M.; Cooper, R.J.; Norton, Terry M.

2009-01-01

Drymarchon couperi (eastern indigo snake) has experienced population declines across its range primarily as a result of extensive habitat loss, fragmentation, and degradation. Conservation efforts for D. couperi have been hindered, in part, because of informational gaps regarding the species, including a lack of data on population ecology and estimates of demographic parameters such as survival. We conducted a 2- year radiotelemetry study of D. couperi on Fort Stewart Military Reservation and adjacent private lands located in southeastern Georgia to assess individual characteristics associated with probability of survival. We used known-fate modeling to estimate survival, and an information-theoretic approach, based on a priori hypotheses, to examine intraspecific differences in survival probabilities relative to individual covariates (sex, size, size standardized by sex, and overwintering location). Annual survival in 2003 and 2004 was 0.89 (95% CI = 0.73-0.97, n = 25) and 0.72 (95% CI = 0.52-0.86; n = 27), respectively. Results indicated that body size, standardized by sex, was the most important covariate determining survival of adult D. couperi, suggesting lower survival for larger individuals within each sex. We are uncertain of the mechanisms underlying this result, but possibilities may include greater resource needs for larger individuals within each sex, necessitating larger or more frequent movements, or a population with older individuals. Our results may also have been influenced by analysis limitations because of sample size, other sources of individual variation, or environmental conditions. ?? 2009 by The Herpetologists' League, Inc.

Population genetic structure and its implications for adaptive variation in memory and the hippocampus on a continental scale in food-caching black-capped chickadees.

PubMed

Pravosudov, V V; Roth, T C; Forister, M L; Ladage, L D; Burg, T M; Braun, M J; Davidson, B S

2012-09-01

Food-caching birds rely on stored food to survive the winter, and spatial memory has been shown to be critical in successful cache recovery. Both spatial memory and the hippocampus, an area of the brain involved in spatial memory, exhibit significant geographic variation linked to climate-based environmental harshness and the potential reliance on food caches for survival. Such geographic variation has been suggested to have a heritable basis associated with differential selection. Here, we ask whether population genetic differentiation and potential isolation among multiple populations of food-caching black-capped chickadees is associated with differences in memory and hippocampal morphology by exploring population genetic structure within and among groups of populations that are divergent to different degrees in hippocampal morphology. Using mitochondrial DNA and 583 AFLP loci, we found that population divergence in hippocampal morphology is not significantly associated with neutral genetic divergence or geographic distance, but instead is significantly associated with differences in winter climate. These results are consistent with variation in a history of natural selection on memory and hippocampal morphology that creates and maintains differences in these traits regardless of population genetic structure and likely associated gene flow. Published 2012. This article is a US Government work and is in the public domain in the USA.

Cancer survival in Eastern and Western Germany after the fall of the iron curtain.

PubMed

Jansen, Lina; Gondos, Adam; Eberle, Andrea; Emrich, Katharina; Holleczek, Bernd; Katalinic, Alexander; Brenner, Hermann

2012-09-01

Prior to the German reunification, cancer survival was much lower in East than in West Germany. We compare cancer survival between Eastern and Western Germany in the early twenty-first century, i.e. the second decade after the German reunification. Using data from 11 population-based cancer registries covering a population of 33 million people, 5-year age-standardized relative survival for the time period 2002-2006 was estimated for the 25 most common cancers using model-based period analysis. In 2002-2006, 5-year relative survival was very similar for most cancers, with differences below 3% units for 20 of 25 cancer sites. Larger, statistically significant survival advantages were seen for oral cavity, oesophagus, and gallbladder cancer and skin melanoma in the West and for leukemia in the East. Our study shows that within two decades after the assimilation of political and health care systems, the former major survival gap of cancer patients in Eastern Germany has been essentially overcome. This result is encouraging as it suggests that, even though economic conditions have remained difficult in Eastern Germany, comparable health care provision may nevertheless enable comparable levels of cancer survival within a relatively short period of time.

Restoring depleted coral-reef fish populations through recruitment enhancement: a proof of concept.

PubMed

Heenan, A; Simpson, S D; Meekan, M G; Healy, S D; Braithwaite, V A

2009-11-01

To determine whether enhancing the survival of new recruits is a sensible target for the restorative management of depleted coral-reef fish populations, settlement-stage ambon damsel fish Pomacentrus amboinensis were captured, tagged and then either released immediately onto small artificial reefs or held in aquaria for 1 week prior to release. Holding conditions were varied to determine whether they affected survival of fish: half the fish were held in bare tanks (non-enriched) and the other half in tanks containing coral and sand (enriched). Holding fish for this short period had a significantly positive effect on survivorship relative to the settlement-stage treatment group that were released immediately. The enrichment of holding conditions made no appreciable difference on the survival of fish once released onto the reef. It did, however, have a positive effect on the survival of fish while in captivity, thus supporting the case for the provision of simple environmental enrichment in fish husbandry. Collecting and holding settlement-stage fish for at least a week before release appear to increase the short-term survival of released fish; whether it is an effective method for longer-term enhancement of locally depleted coral-reef fish populations will require further study.

Surgical treatment for women with breast cancer: do randomized clinical trials represent current medical practices?

PubMed

Frederick, Wayne A I; Ames, Sarah; Downing, Stephanie R; Oyetunji, Tolulope A; Chang, David C; Leffall, Lasalle D

2010-06-01

Randomized clinical trials have not shown survival differences between breast cancer patients who undergo breast-conserving surgery and those who undergo modified radical mastectomy (MRM). Recent studies however, have suggested that these randomized clinical trials findings may not be representative of the entire population or the nature of current patient care. A retrospective analysis of female invasive breast cancer patients who underwent surgery in the Surveillance, Epidemiology, and End Results database (1990-2003) was performed. Survival was compared amongst women who underwent partial mastectomy, partial mastectomy plus radiation (PMR), or MRM. Cox proportional hazards regressions were used to investigate the impact of method of treatment upon survival, after adjusting for patient and tumor characteristics. A total of 218,043 patients, mean age 62 years, were identified. MRM accounted for 51.5 per cent of the study population whereas PMR accounted for 34.9 per cent. On multivariate analyses, significant improvement was observed in patient survival associated with PMR when compared with MRM patients (hazard ratio = 0.71, 95% confidence interval = 0.67-0.74, P < 0.001). This population-based study suggests that there is a survival benefit for women undergoing PMR in the treatment of breast cancer.

Low survival rates of Swan Geese (Anser cygnoides) estimated from neck-collar resighting and telemetry

USGS Publications Warehouse

Choi, Chang-Yong; Lee, Ki-Sup; Poyarkov, Nikolay D.; Park, Jin-Young; Lee, Hansoo; Takekawa, John Y.; Smith, Lacy M.; Ely, Craig R.; Wang, Xin; Cao, Lei; Fox, Anthony D.; Goroshko, Oleg; Batbayar, Nyambayar; Prosser, Diann J.; Xiao, Xiangming

2016-01-01

Waterbird survival rates are a key component of demographic modeling used for effective conservation of long-lived threatened species. The Swan Goose (Anser cygnoides) is globally threatened and the most vulnerable goose species endemic to East Asia due to its small and rapidly declining population. To address a current knowledge gap in demographic parameters of the Swan Goose, available datasets were compiled from neck-collar resighting and telemetry studies, and two different models were used to estimate their survival rates. Results of a mark-resighting model using 15 years of neck-collar data (2001–2015) provided age-dependent survival rates and season-dependent encounter rates with a constant neck-collar retention rate. Annual survival rate was 0.638 (95% CI: 0.378–0.803) for adults and 0.122 (95% CI: 0.028–0.286) for first-year juveniles. Known-fate models were applied to the single season of telemetry data (autumn 2014) and estimated a mean annual survival rate of 0.408 (95% CI: 0.152–0.670) with higher but non-significant differences for adults (0.477) vs. juveniles (0.306). Our findings indicate that Swan Goose survival rates are comparable to the lowest rates reported for European or North American goose species. Poor survival may be a key demographic parameter contributing to their declining trend. Quantitative threat assessments and associated conservation measures, such as restricting hunting, may be a key step to mitigate for their low survival rates and maintain or enhance their population.

Age and case mix-standardised survival for all cancer patients in Europe 1999-2007: Results of EUROCARE-5, a population-based study.

PubMed

Baili, Paolo; Di Salvo, Francesca; Marcos-Gragera, Rafael; Siesling, Sabine; Mallone, Sandra; Santaquilani, Mariano; Micheli, Andrea; Lillini, Roberto; Francisci, Silvia

2015-10-01

Overall survival after cancer is frequently used when assessing a health care service's performance as a whole. It is mainly used by the public, politicians and the media, and is often dismissed by clinicians because of the heterogeneous mix of different cancers, risk factors and treatment modalities. Here we give survival details for all cancers combined in Europe, correlating it with economic variables to suggest reasons for differences. We computed age and cancer site case-mix standardised relative survival for all cancers combined (ACRS) for 29 countries participating in the EUROCARE-5 project with data on more than 7.5million cancer cases from 87 population-based cancer registries, using complete and period approach. Denmark, United Kingdom (UK) and Eastern European countries had lower survival than neighbouring countries. Five-year ACRS has been increasing throughout Europe, and substantial increases, between 1999-2001 and 2005-2007, have been achieved in countries where survival was lower in the past. Five-year ACRS for men and women are positively correlated with macro-economic variables like the Gross Domestic Product (GDP) and Total National Expenditure on Health (TNEH) (R 2 about 70%). Countries with recent larger increases in GDP and TNEH had greater increases in cancer survival. ACRS serves to compare all cancer survival in Europe taking account of the geographical variability in case-mixes. The EUROCARE-5 data on ACRS confirm previous EUROCARE findings. Survival appears to correlate with macro-economic determinants, particularly with investments in the health care system. Copyright © 2015 Elsevier Ltd. All rights reserved.

Populational divergence in the impact of three nitrogenous compounds and their combination on larvae of the frog Pelophylax perezi (Seoane, 1885).

PubMed

Egea-Serrano, Andrés; Tejedo, Miguel; Torralva, Mar

2009-08-01

Pollution by nitrogenous compounds is a putative stressful factor that may be causally linked to the decline of amphibians. One way to understand the potentially detrimental consequences of eutrophication on amphibian populations is to investigate variation among populations differing in exposure to nitrogen, this variation potentially indicating evolutionary potential to cope with this stressor. We have examined the effect of nitrogenous compounds (NH(4)(+); NO(2)(-); NO(3)(-), both alone and in combination) on fitness-related larval traits in four populations of Pelophylax perezi naturally exposed to different degrees of eutrophication. The results indicate that both survival and larval final size decrease at higher concentrations of these compounds, either singly or in combination. Additionally, the nitrogenous compounds were more lethal and larval food consumption and final mass were significantly reduced when they were exposed to combinations of compounds. Populations inhabiting highly polluted aquatic environments tolerated higher levels of nitrogenous compounds and showed higher survival rates and larger final size than the populations of less polluted environments, suggesting the potential to adapt to increased nitrogenous contamination in this species.

Modeling Disjunct Gray Wolf Populations in Semi-Wild Landscapes

Treesearch

Robert G. Haight; David J. Mladenoff; Adrian P. Wydeven

1998-01-01

Gray wolves (Canis lupus) in parts of the United States and Europe live in networks of disjunct populations, many of which are close to human settlement. Because wolf management goals include sustaining disjunct populations, it is important to ask what types of areas and protections are needed for population survival. To predict the effects of different levels of human...

Natural variation in resistance to desiccation and heat shock protein expression in the land snail Theba pisana along a climatic gradient.

PubMed

Mizrahi, Tal; Goldenberg, Shoshana; Heller, Joseph; Arad, Zeev

2015-01-01

Land snails frequently encounter desiccating conditions, and their survival depends on a suite of morphological, physiological, and molecular adaptations to the specific microhabitat. Strategies of survival can be determined by integrating information from various levels of biological organization. In this study, we used a combination of physiological parameters related to water economy and molecular factors (stress protein expression) to investigate the strategies of survival adopted by seven populations of the Mediterranean-type land snail Theba pisana from different habitats. We analyzed water compartmentalization during aestivation and used experimental desiccation to compare desiccation resistance. We also measured the endogenous levels of heat shock proteins (HSPs) Hsp72, Hsp74, and Hsp90 under nonstress conditions and analyzed the HSP response to desiccation in two populations that differed mostly in their resistance to desiccation. We revealed significant intraspecific differences in resistance to desiccation that seem to be determined by the speed of recruitment of the water-preserving mechanisms. The ability to cope with desiccating conditions was correlated with habitat temperature but not with the rainfall gradient, implying that in the coastal region, temperature is likely to have a major impact on desiccation resistance rather than precipitation. Also, higher desiccation resistance was correlated with higher constitutive levels of Hsp74 in the foot tissue. HSPs were upregulated during desiccation, but the response was delayed and was milder in the most resistant population compared to the most susceptible one. Our study suggests that T. pisana populations from warmer habitats were more resistant to desiccation and developed distinct strategies of HSP expression for survival, namely, the maintenance of high constitutive levels of Hsp70 together with a delayed and limited response to stress.

Survival Differences among Native-Born and Foreign-Born Older Adults in the United States

PubMed Central

Dupre, Matthew E.; Gu, Danan; Vaupel, James W.

2012-01-01

Background Studies show that the U.S. foreign-born population has lower mortality than the native-born population before age 65. Until recently, the lack of data prohibited reliable comparisons of U.S. mortality by nativity at older ages. This study provides reliable estimates of U.S. foreign-born and native-born mortality at ages 65 and older at the end of the 20th century. Life expectancies of the U.S. foreign born are compared to other developed nations and the foreign-born contribution to total life expectancy (TLE) in the United States is assessed. Methods Newly available data from Medicare Part B records linked with Social Security Administration files are used to estimate period life tables for nearly all U.S. adults aged 65 and older in 1995. Age-specific survival differences and life expectancies are examined in 1995 by sex, race, and place of birth. Results Foreign-born men and women had lower mortality at almost every age from 65 to 100 compared to native-born men and women. Survival differences by nativity were substantially greater for blacks than whites. Foreign-born blacks had the longest life expectancy of all population groups (18.73 [95% confidence interval {CI}, 18.15–19.30] years at age 65 for men and 22.76 [95% CI, 22.28–23.23] years at age 65 for women). The foreign-born population increased TLE in the United States at older ages, and by international comparison, the U.S. foreign born were among the longest-lived persons in the world. Conclusion Survival estimates based on reliable Medicare data confirm that foreign-born adults have longer life expectancy at older ages than native-born adults in the United States. PMID:22615929

Survival estimates of wild and captive-bred released Puaiohi, an endangered Hawaiian thrush

USGS Publications Warehouse

VanderWerf, Eric; Crampton, Lisa H.; Diegmann, Julia; Atkinson, Carter T.; Leonard, David L.

2014-01-01

Estimating and monitoring adult and juvenile survival are vital to understanding population status, informing recovery planning for endangered species, and quantifying the success of management. We used mark–recapture models to estimate apparent annual survival of the Puaiohi (Myadestes palmeri), an endangered thrush endemic to the Hawaiian island of Kauai, from 2005 to 2011. Our sample included 87 wild birds and 123 captive-bred birds that were released at various ages. Survival was higher for wild adult males (0.71 ± 0.09) than for wild adult females (0.46 ± 0.12). Survival of wild juveniles (0.23 ± 0.06) was lower than that of wild adults of both sexes, indicating that recruitment may limit population growth. Captive-bred birds released when <1 yr old had survival (0.26 ± 0.21) comparable with that of wild juveniles, but captive-bred birds released at 1–3 yr old had very low survival (0.05 ± 0.06). Only 8 of 123 (7%) captive birds were seen again after release. Two wild birds resighted five years after marking are the oldest known individuals, being at least six years of age. Malarial infection did not affect survival of wild Puaiohi, unlike many Hawaiian forest birds. The difference between adult male and adult female survival is consistent with rat (Rattusspp.) predation of females on the nest as a major source of mortality. As such, attempting to reduce nest predation by controlling rats may be the best available management option. Releasing captive-bred birds has had little effect on the wild population in recent years.

Improved long-term survival with subdural drains following evacuation of chronic subdural haematoma.

PubMed

Guilfoyle, Mathew R; Hutchinson, Peter J A; Santarius, Thomas

2017-05-01

Chronic subdural haematoma (CSDH) is a common condition that is effectively managed by burrhole drainage but requires repeat surgery in a significant minority of patients. The Cambridge Chronic Subdural Haematoma Trial (CCSHT) was a randomised controlled study that showed placement of subdural drains for 48 h following burrhole evacuation significantly reduces the incidence of reoperation and improves survival at 6 months. The present study examined the long-term survival of the patients in the trial. In the original trial patients at a single neurosurgical centre from 2004-2007 were randomly assigned to receive a drain (n = 108) or no drain (n = 107) following burrhole drainage of CSDH. We ascertained whether the trial patients were alive in February 2016-a minimum of 8 years following enrollment-via the UK NHS tracing service. Survival was compared between the trial groups and against expected survival for the UK general population matched for age and sex. At 5 years following surgery the drain group continued to have significantly better survival than the no drain patients (p = 0.027), but this was no longer apparent at 10 years. Survival of patients in the drain group did not differ significantly from that of the general population whereas patients who did not receive a drain had significantly lower survival than expected (p = 0.0006). Subdural drains following CSDH evacuation are associated with improved long-term survival, which appears similar to that expected for the general population of the same age and sex. All patients having burrhole CSDH evacuation should receive a drain as standard practice unless specifically contraindicated.

Challenges in the estimation of Net SURvival: The CENSUR working survival group.

PubMed

Giorgi, R

2016-10-01

Net survival, the survival probability that would be observed, in a hypothetical world, where the cancer of interest would be the only possible cause of death, is a key indicator in population-based cancer studies. Accounting for mortality due to other causes, it allows cross-country comparisons or trends analysis and provides a useful indicator for public health decision-making. The objective of this study was to show how the creation and formalization of a network comprising established research teams, which already had substantial and complementary experience in both cancer survival analysis and methodological development, make it possible to meet challenges and thus provide more adequate tools, to improve the quality and the comparability of cancer survival data, and to promote methodological transfers in areas of emerging interest. The Challenges in the Estimation of Net SURvival (CENSUR) working survival group is composed of international researchers highly skilled in biostatistics, methodology, and epidemiology, from different research organizations in France, the United Kingdom, Italy, Slovenia, and Canada, and involved in French (FRANCIM) and European (EUROCARE) cancer registry networks. The expected advantages are an interdisciplinary, international, synergistic network capable of addressing problems in public health, for decision-makers at different levels; tools for those in charge of net survival analyses; a common methodology that makes unbiased cross-national comparisons of cancer survival feasible; transfer of methods for net survival estimations to other specific applications (clinical research, occupational epidemiology); and dissemination of results during an international training course. The formalization of the international CENSUR working survival group was motivated by a need felt by scientists conducting population-based cancer research to discuss, develop, and monitor implementation of a common methodology to analyze net survival in order to provide useful information for cancer control and cancer policy. A "team science" approach is necessary to address new challenges concerning the estimation of net survival. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Stochastic population dynamics under resource constraints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gavane, Ajinkya S., E-mail: ajinkyagavane@gmail.com; Nigam, Rahul, E-mail: rahul.nigam@hyderabad.bits-pilani.ac.in

This paper investigates the population growth of a certain species in which every generation reproduces thrice over a period of predefined time, under certain constraints of resources needed for survival of population. We study the survival period of a species by randomizing the reproduction probabilities within a window at same predefined ages and the resources are being produced by the working force of the population at a variable rate. This randomness in the reproduction rate makes the population growth stochastic in nature and one cannot predict the exact form of evolution. Hence we study the growth by running simulations formore » such a population and taking an ensemble averaged over 500 to 5000 such simulations as per the need. While the population reproduces in a stochastic manner, we have implemented a constraint on the amount of resources available for the population. This is important to make the simulations more realistic. The rate of resource production then is tuned to find the rate which suits the survival of the species. We also compute the mean life time of the species corresponding to different resource production rate. Study for these outcomes in the parameter space defined by the reproduction probabilities and rate of resource production is carried out.« less

Comparison of cancer survival in New Zealand and Australia, 2006-2010.

PubMed

Aye, Phyu S; Elwood, J Mark; Stevanovic, Vladimir

2014-12-19

Previous studies have shown substantially higher mortality rates from cancer in New Zealand compared to Australia, but these studies have not included data on patient survival. This study compares the survival of cancer patients diagnosed in 2006-10 in the whole populations of New Zealand and Australia. Identical period survival methods were used to calculate relative survival ratios for all cancers combined, and for 18 cancers each accounting for more than 50 deaths per year in New Zealand, from 1 to 10 years from diagnosis. Cancer survival was lower in New Zealand, with 5-year relative survival being 4.2% lower in women, and 3.8% lower in men for all cancers combined. Of 18 cancers, 14 showed lower survival in New Zealand; the exceptions, with similar survival in each country, being melanoma, myeloma, mesothelioma, and cervical cancer. For most cancers, the differences in survival were maximum at 1 year after diagnosis, becoming smaller later; however, for breast cancer, the survival difference increased with time after diagnosis. The lower survival in New Zealand, and the higher mortality rates shown earlier, suggest that further improvements in recognition, diagnosis, and treatment of cancer in New Zealand should be possible. As the survival differences are seen soon after diagnosis, issues of early management in primary care and time intervals to diagnosis and treatment may be particularly important.

The regrowth kinetic of the surviving population is independent of acute and chronic responses to temozolomide in glioblastoma cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, Andrew Oliveira, E-mail: andrewbiomed@gmail.com; Dalsin, Eloisa, E-mail: dalsineloisa@gmail.com; Onzi, Giovana Ravizzoni, E-mail: gioonzi@gmail.com

Chemotherapy acts on cancer cells by producing multiple effects on a cell population including cell cycle arrest, necrosis, apoptosis and senescence. However, often a subpopulation of cells survives and the behavior of this subpopulation, which is responsible for cancer recurrence, remains obscure. Here we investigated the in vitro short- and long-term responses of six glioblastoma cell lines to clinically relevant doses of temozolomide for 5 days followed by 23 days of recovery, mimicking the standard schedule used in glioblastoma patient for this drug. These cells presented different profiles of sensitivity to temozolomide with varying levels of cell cycle arrest, autophagymore » and senescence, followed by a regrowth of the surviving cells. The initial reduction in cell number and the subsequent regrowth was analyzed with four new parameters applied to Cumulative Population Doubling (CPD) curves that describe the overall sensitivity of the population and the characteristic of the regrowth: the relative end point CPD (RendCPD); the relative Area Under Curve (rAUC); the Relative Time to Cross a Threshold (RTCT); and the Relative Proliferation Rate (RPR). Surprisingly, the kinetics of regrowth were not predicted by the mechanisms activated after treatment nor by the acute or overall sensitivity. With this study we added new parameters that describe key responses of glioblastoma cell populations to temozolomide treatment. These parameters can also be applied to other cell types and treatments and will help to understand the behavior of the surviving cancer cells after treatment and shed light on studies of cancer resistance and recurrence. - Highlights: • Little is known about the behavior of the glioma cells surviving to TMZ. • The short- and long-term response of six glioma cells lines to TMZ varies considerably. • These glioma cells lines recovered proliferation after therapeutic levels of TMZ. • The growth velocity of the surviving cells was different from the untreated cells. • The kinetic of regrowth was not predicted by any TMZ-triggered mechanism.« less

Perceptions of Oncologists, Healthcare Policy Makers, Patients and the General Population on the Value of Pharmaceutical Treatments in Oncology.

PubMed

Sacristán, José A; Lizan, Luís; Comellas, Marta; Garrido, Pilar; Avendaño, Cristina; Cruz-Hernández, Juan J; Espinosa, Javier; Dilla, Tatiana

2016-11-01

The purpose of this study was to explore the main factors explaining the relative weight of the different attributes that determine the value of oncologic treatments from the different perspectives of healthcare policy makers (HCPM), oncologists, patients and the general population in Spain. Structured interviews were conducted to assess: (1) the importance of the attributes on treatment choice when comparing a new cancer drug with a standard cancer treatment; (2) the importance of survival, quality of life (QoL), costs and innovation in cancer; and (3) the most worrying side effects related to cancer drugs. A total of 188 individuals participated in the study. For all participants, when choosing treatments, the best rated characteristics were greater efficacy, greater safety, treatment adaptation to patients' individual requirements and the rapid reincorporation of patients to their daily activities. There were important differences among participants in their opinion about survival, QoL and cost. In general, oncologists, patients, and the general population gave greater value to gains in QoL than healthcare policy makers. Compared to other participants healthcare policy makers gave greater importance to the economic impact related to oncology treatments. Gains in QoL, survival, safety, cost and innovation are perceived differently by different groups of stakeholders. It is recommended to consider the perspective of different stakeholders in the assessment of a new cancer drugs to obtain more informed decisions when deciding on the most appropriate treatment to use. Eli Lilly & Co, Madrid (Spain).

Age and condition of juvenile catostomids in Clear Lake Reservoir, California

USGS Publications Warehouse

Burdick, Summer M.; Rasmussen, Josh

2013-01-01

Although infrequent recruitment of new individuals into the adult spawning populations of Lost River suckers (Deltistes luxatus) and shortnose suckers (Chasmistes brevirostris) limits recovery of these species in Upper Klamath Lake, it is not clear that populations are recruitment limited in Clear Lake Reservoir (hereafter Clear Lake). Specifically, some evidence indicates that shortnose suckers may regularly recruit to the adult spawning population in Clear Lake. Therefore, a study of early life history patterns and recruitment dynamics in Clear Lake may lead to a better understanding of what is limiting recovery of suckers in both lakes. Adult suckers in Clear Lake migrate up Willow Creek and its tributaries to spawn in some years, but low flow in Willow Creek may inhibit spawning migrations in other years. It is unclear whether spawning is successful, larvae survive, or how frequently juveniles persist to adulthood. Environmental variables associated with successful spawning or young-of-year survival have not been identified, and early life history for these populations is poorly understood. The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, initiated a study in 2011 to better understand juvenile sucker life history in Clear Lake, and to identify constraints in the early life history that may limit recruitment to the adult spawning populations. The relative weights of shortnose suckers from Clear Lake and Upper Klamath Lake were compared to examine differences in condition. However, it is unclear whether the disparity in relative weights between the populations reflects differences in condition, phenotype, or both. Approximately 80 percent of juvenile suckers in Clear Lake are shortnose suckers with some morphologic features similar to Klamath largescale suckers (Catostomus snyderi), whereas juvenile suckers in Upper Klamath Lake can be clearly classified as either shortnose or Lost River suckers. The presence of juvenile suckers age-3 and older indicate that production, larval survival, and juvenile survival are at least periodically sufficient to lead to recruitment into the adult population of shortnose suckers in Clear Lake.

Diminished Disease-Free Survival After Lobectomy: Screening Implications.

PubMed

Reich, Jerome M; Kim, Jong S; Asaph, James W

2015-09-01

The aim of this study was to estimate the effect of lobectomy on life expectancy in healthy smokers and consider the implications for lung cancer screening. In a retrospective cohort study that provided a minimum of 15 years of follow-up, we analyzed lung cancer survival, all-cause survival, and fatality (1-survival) of 261 persons with stage I non-small-cell lung cancer who underwent lobectomy at Portland Providence Medical Center between 1978 and 1994. We: (1) compared 5-year disease-free fatality (non-lung-cancer fatality) with lung cancer fatality; and (2) based on actuarial data that demonstrated life expectancy equivalence of the healthiest smokers (whom we assumed would be comparable with subjects judged eligible for lobectomy) in the US population, we compared their long-term, disease-free survival (our primary end point) with actuarial expectations by computing the Kaplan-Meier survival function of the differences between lifetimes since surgery in disease-free persons versus matched, expected remaining lifetimes in the US population. (1) Five-year disease-free fatality (16.1%) was 58% as high as 5-year lung cancer fatality (27.6%); (2) disease-free survival was reduced by 6.9-years (95% confidence interval, 5.5-8.3), 41% of actuarial life expectancy (17 years). The divergence from expected survival took place largely after 6 years of follow-up. Lobectomy materially diminishes long-term disease-free survival in the healthiest smokers--persons judged healthy enough to tolerate major surgery and to have sufficient pulmonary reserve to sustain loss of one-fifth of their lung tissue. In screened populations, diminished survival in overdiagnosed persons will offset, to an undetermined extent, the mortality benefit imparted by preemption of advanced lung cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

Survival of adult female northern pintails in Sacramento Valley, California

USGS Publications Warehouse

Miller, Michael R.; Fleskes, Joseph P.; Orthmeyer, Dennis L.; Newton, Wesley E.; Gilmer, David S.

1995-01-01

North American populations of northern pintails (Anas acuta) declined between 1979 and the early 1990s. To determine if low survival during winter contributed to declines, we estimated winter (last week of Aug-Feb 1987-90) survival for 190 adult (after hatching yr [AHY]) female radio-tagged pintails in late summer in Sacramento Valley (SACV), California. Survival rates did not vary by winter (P = 0.808), among preseason, hunting season, or postseason intervals (P = 0.579), or by body mass at time of capture (P = 0.127). Premolt (wing) pintails (n = 10) tended to survive at a lower rate (0.622, SE = 0.178) than pintails that had already replaced flight feathers (0.887, SE = 0.030) (P = 0.091). The pooled survival (all years) estimate for the 180-day winter was 0.874 (SE = 0.031). Hunting mortality rate (0.041-0.087) and nonhunting mortality rate (0.013-0.076) did not differ among years (P = 0.332) or within years (all P > 0.149). Legal hunting (n = 7), predation (n = 4), cholera (n = 2), illegal shooting (n = 2), botulism (n = 1), and unknown cause (n = 1) accounted for all mortality. Nonwintering survival (annu. survival/winter survival = 0.748) was lower than winter survival; thus, if gains in annual survival are desired for this population, managers should first examine the breeding-migration period for opportunities to achieve increases.

Real-life 10-year retention rate of first-line anti-TNF drugs for inflammatory arthritides in adult- and juvenile-onset populations: similarities and differences.

PubMed

Favalli, Ennio Giulio; Pontikaki, Irene; Becciolini, Andrea; Biggioggero, Martina; Ughi, Nicola; Romano, Micol; Crotti, Chiara; Gattinara, Maurizio; Gerloni, Valeria; Marchesoni, Antonio; Meroni, Pier Luigi

2017-08-01

The aim of this study is to retrospectively analyze 10-year drug survival of first-line TNF inhibitor (TNFi) in rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), and juvenile idiopathic arthritis (JIA) patients, comparing withdrawal rates and discontinuation pattern between adult- and juvenile-onset populations. RA, AS, PsA, and JIA patients treated with infliximab, etanercept, or adalimumab as first TNFi between 1999 and 2015 were extracted from a local registry. Drug survival up to 10-year follow-up was evaluated by the Kaplan-Meier method and compared according to age (adult vs juvenile onset), TNFi agent, and discontinuation reason by a stratified log-rank test. Three hundred sixty JIA (205 etanercept, 66 adalimumab, and 89 infliximab) and 951 (607 RA, 188 AS, and 156 PsA) adult patients (464 infliximab, 262 adalimumab, and 225 etanercept) were included. After exclusion of systemic-onset JIA (18.5%), overall 10-year retention rate was 31.8%, with no difference between adult- and juvenile-onset patients (32.1 and 30.2%, respectively; HR 0.938 [95% CI 0.782-1.125]). Etanercept showed the highest drug survival in adult-onset population (p < 0.0001 vs both monoclonal antibodies) and infliximab the lowest in juvenile-onset population (p = 0.005 vs adalimumab and p < 0.0001 vs etanercept). Inefficacy was the most frequent reason for TNFi withdrawal in adult population (29.75%) with a significantly higher risk of discontinuation than in juvenile-onset subgroup (HR 1.390 [95% CI 1.060-1.824]). Serious infections and malignancies caused TNFi withdrawal only in adult whereas gastrointestinal, neuropsychiatric, and ocular complications quite only in juvenile patients. Despite a similar 10-year drug survival, adult- and juvenile-onset subpopulations showed a significantly different pattern of TNFi reasons for discontinuation.

Thermal responses and survival after heat exposure are modulated by maintained differences in body temperature in mice

NASA Astrophysics Data System (ADS)

Fishman, Rachelle H. B.

1988-03-01

When individual mice were examined, it was found that the colonic body temperature T col of each individual within a genetically heterogeneous population tended to remain either above (“warm”) or below (“cool”) the population mean. T col of warm, but not cool, mice showed circadian variation. When exposed to a T a of 43° C, the T col of cool mice increased by as musch as 2.4° C more than that of warm mice for a given 15 min increment of heating at 43°C. Survival of mice after acute lethal heat load (LD75, -45°C) was significantly inversely correlated with T col. Small persistent differences in body temperature of individuals may indicate differing thermal adaptedness.

Effects of individual quality, reproductive success and environmental variability on survival of a long-lived seabird.

PubMed

Lescroël, Amélie; Dugger, Katie M; Ballard, Grant; Ainley, David G

2009-07-01

1. Heterogeneity in individual quality (i.e. individuals having different performance levels that are consistent throughout life) can drive the demography of iteroparous species, but quality in the context of environmental variability has rarely been evaluated. 2. We investigated the demographic responses of a long-lived seabird, the Adélie penguin (Pygoscelis adeliae), to contrasting environmental conditions as a function of reproductive success, breeding quality (BQ) and experience. A continuous index of BQ (BQI) was developed to reflect an individual's ability, relative to others, to produce viable offspring. 3. First, we assessed the relative importance of costs of reproduction vs. heterogeneity in quality by comparing survival and reproductive probabilities among deferred, successful and unsuccessful breeders under 'demanding' conditions using multistate capture-mark-recapture modelling. Then, we quantified the influence of BQI on adult survival among experienced breeders vs. the whole study population under both 'normal' and 'demanding' conditions. 4. Higher survival rates were exhibited by successful (74-76%) compared to unsuccessful breeders (64%); the former also more frequently reproduced successfully at year t + 1. 5. From 1997 to 2006, adult survival ranged from 64-79%, with BQI accounting for 91% of variability in the entire study population, but only 17% in experienced breeders. The weakened relationship between BQI and survival in experienced breeders supports the theory that selection during the first reproductive event accounts for a more homogeneous pool of experienced breeders. 6. No significant effect of environmental covariates on survival was evident, suggesting that what appeared to be demanding conditions were within the range that could be buffered by this species. 7. For the first time in seabirds, a quadratic relationship between adult survival and BQI showed that adult survival is shaped by both heterogeneity in quality and reproductive costs. Our study confirms that population demographic patterns are affected by factors at the individuals' level (e.g., individual quality) that are obscured at population-scale levels.

The influence of disturbance events on survival and dispersal rates of Florida box turtles

USGS Publications Warehouse

Dodd, C.K.; Ozgul, A.; Oli, M.K.

2006-01-01

Disturbances have the potential to cause long-term effects to ecosystem structure and function, and they may affect individual species in different ways. Long-lived vertebrates such as turtles may be at risk from such events, inasmuch as their life histories preclude rapid recovery should extensive mortality occur. We applied capture–mark–recapture models to assess disturbance effects on a population of Florida box turtles (Terrapene carolina bauri) on Egmont Key, Florida, USA. Near the midpoint of the study, a series of physical disturbances affected the island, from salt water overwash associated with several tropical storms to extensive removal of nonindigenous vegetation. These disturbances allowed us to examine demographic responses of the turtle population and to determine if they affected dispersal throughout the island. Adult survival rates did not vary significantly either between sexes or among years of the study. Survival rates did not vary significantly between juvenile and adult turtles, or among years of the study. Furthermore, neither adult nor juvenile survival rates differed significantly between pre- and post-disturbance. However, dispersal rates varied significantly among the four major study sites, and dispersal rates were higher during the pre-disturbance sampling periods compared to post-disturbance. Our results suggest few long-term effects on the demography of the turtle population. Florida box turtles responded to tropical storms and vegetation control by moving to favorable habitats minimally affected by the disturbances and remaining there. As long as turtles and perhaps other long-lived vertebrates can disperse to non-disturbed habitat, and high levels of mortality do not occur in a population, a long life span may allow them to wait out the impact of disturbance with potentially little effect on long-term population processes.

Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

PubMed Central

Shu, Longfei; Laurila, Anssi; Räsänen, Katja

2015-01-01

Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca2+ influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca2+ balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress. PMID:26381453

Effect of storage temperature on survival and recovery of thermal and extrusion injured Escherichia coli populations in whey protein concentrate and corn meal

USDA-ARS?s Scientific Manuscript database

In a previous study, we reported viability loss of Escherichia coli populations in corn (CP) and whey protein products (WPP) extruded at different temperatures. However, information on the effect of storage temperatures on injured bacterial populations was not addressed. The objective of this study ...

Endometrial cancer: socioeconomic status and racial/ethnic differences in stage at diagnosis, treatment, and survival.

PubMed

Madison, Terri; Schottenfeld, David; James, Sherman A; Schwartz, Ann G; Gruber, Stephen B

2004-12-01

We evaluated the association between socioeconomic status and racial/ ethnic differences in endometrial cancer stage at diagnosis, treatment, and survival. We conducted a population-based study among 3656 women. Multivariate analyses showed that either race/ethnicity or income, but not both, was associated with advanced-stage disease. Age, stage at diagnosis, and income were independent predictors of hysterectomy. African American ethnicity, increased age, aggressive histology, poor tumor grade, and advanced-stage disease were associated with increased risk for death; higher income and hysterectomy were associated with decreased risk for death. Lower income was associated with advanced-stage disease, lower likelihood of receiving a hysterectomy, and lower rates of survival. Earlier diagnosis and removal of barriers to optimal treatment among lower-socioeconomic status women will diminish racial/ethnic differences in endometrial cancer survival.

Count trends for migratory Bald Eagles reveal differences between two populations at a spring site along the Lake Ontario shoreline

PubMed Central

2016-01-01

The recovery of Bald Eagles (Haliaeetus leucophalus), after DDT and other organochlorine insecticides were banned in the United States, can be regarded as one of the most iconic success stories resulting from the Endangered Species Act. Interest remains high in the recovery and growth of the Bald Eagle population. Common to evaluating growth and recovery rates are counts at nesting sites and analyses of individuals fledged per season. But this is merely one snapshot that ignores survival rates as eagles grow to maturity. By analyzing indices from migration counts, we get a different snapshot better reflecting the survival of young birds. Different populations of Bald Eagles breed at different sites at different times of the year. Typical migration count analyses do not separate the populations. A separation of two distinct populations can be achieved at spring count sites by taking advantage of the tendency for northern summer breeding birds to migrate north in spring earlier than southern winter breeding birds who disperse north later in spring. In this paper I analyze migratory indices at a spring site along Lake Ontario. The analysis shows that eagles considered to be primarily of the northern summer breeding population showed an estimated growth rate of 5.3 ± 0.85% (SE) per year with 49% of eagles tallied in adult plumage, whereas the migrants considered to be primarily of the southern breeding population had an estimated growth rate of 14.0 ± 1.79% with only 22% in adult plumage. Together these results argue that the populations of southern breeding Bald Eagles are growing at a substantially higher rate than northern breeding eagles. These findings suggest that aggregate population indices for a species at migration counting sites can sometimes obscure important differences among separate populations at any given site and that separating counts by time period can be a useful way to check for differences among sub-populations. PMID:27231647

Geographic variation in the response of Culex pipiens life history traits to temperature.

PubMed

Ruybal, Jordan E; Kramer, Laura D; Kilpatrick, A Marm

2016-02-29

Climate change is predicted to alter the transmission of many vector-borne pathogens. The quantitative impact of climate change is usually estimated by measuring the temperature-performance relationships for a single population of vectors, and then mapping this relationship across a range of temperatures or locations. However, life history traits of different populations often differ significantly. Specifically, performance across a range of temperatures is likely to vary due to local adaptation to temperature and other factors. This variation can cause spatial variation in pathogen transmission and will influence the impact of climate change on the transmission of vector-borne pathogens. We quantified variation in life history traits for four populations of Culex pipiens (Linnaeus) mosquitoes. The populations were distributed along altitudinal and latitudinal gradients in the eastern United States that spanned ~3 °C in mean summer temperature, which is similar to the magnitude of global warming expected in the next 3-5 decades. We measured larval and adult survival, development rate, and biting rate at six temperatures between 16 and 35 °C, in a common garden experiment. Temperature had strong and consistent non-linear effects on all four life history traits for all four populations. Adult female development time decreased monotonically with increasing temperature, with the largest decrease at cold temperatures. Daily juvenile and adult female survival also decreased with increasing temperature, but the largest decrease occurred at higher temperatures. There was significant among-population variation in the thermal response curves for the four life history traits across the four populations, with larval survival, adult survival, and development rate varying up to 45, 79, and 84 % among populations, respectively. However, variation was not correlated with local temperatures and thus did not support the local thermal adaptation hypothesis. These results suggest that the impact of climate change on vector-borne disease will be more variable than previous predictions, and our data provide an estimate of this uncertainty. In addition, the variation among populations that we observed will shape the response of vectors to changing climates.

Population dynamics of Microtus pennsylvanicus in corridor-linked patches

USGS Publications Warehouse

Coffman, C.J.; Nichols, J.D.; Pollock, K.H.

2001-01-01

Corridors have become a key issue in the discussion of conservation planning: however, few empirical data exist on the use of corridors and their effects on population dynamics. The objective of this replicated, population level, capture-re-capture experiment on meadow voles was to estimate and compare population characteristics of voles between (1) corridor-linked fragments, (2) isolated or non-linked fragments, and (3) unfragmented areas. We conducted two field experiments involving 22600 captures of 5700 individuals. In the first, the maintained corridor study, corridors were maintained at the time of fragmentation, and in the second, the constructed corridor study, we constructed corridors between patches that had been fragmented for some period of time. We applied multistate capture-recapture models with the robust design to estimate adult movement and survival rates, population size, temporal variation in population size, recruitment, and juvenile survival rates. Movement rates increased to a greater extent on constructed corridor-linked grids than on the unfragmented or non-linked fragmented grids between the pre- and post-treatment periods. We found significant differences in local survival on the treated (corridor-linked) grids compared to survival on the fragmented and unfragmented grids between the pre- and post-treatment periods. We found no clear pattern of treatment effects on population size or recruitment in either study. However, in both studies, we found that unfragmented grids were more stable than the fragmented grids based on lower temporal variability in population size. To our knowledge, this is the first experimental study demonstrating that corridors constructed between existing fragmented populations can indeed cause increases in movement and associated changes in demography, supporting the use of constructed corridors for this purpose in conservation biology.

Application of the stage-projection model with density-dependent fecundity to the population dynamics of Spanish ibex

USGS Publications Warehouse

Escos, J.; Alados, C.L.; Emlen, John M.

1994-01-01

A stage-class population model with density-feedback term included was used to identify the most critical parameters determining the population dynamics of female Spanish ibex (Capra pyrenaica) in southern Spain. A population in the Cazorla and Segura mountains is rapidly declining, but the eastern Sierra Nevada population is growing. The stable population density obtained using estimated values of kid and adult survival (0.49 and 0.87, respectively) and with fecundity equal to 0.367 in the absence of density feedback is 12.7 or 16.82 individuals/km2, based on a non-time-lagged and a time-lagged model, respectively. Given the maximum estimate of fecundity and an adult survival rate of 0.87, a kid survival rate of at least 0.41 is required to avoid extinction. At the minimum fecundity estimate, kid survival would have to exceed 0.52. Elasticities were used to estimate the influence of variation in life-cycle parameters on the intrinsic rate of increase. Adult survival is the most critical parameter, while fecundity and juvenile survival are less important. An increase in adult survival from 0.87 to 0.91 in the Cazorla and Segura mountains population would almost stabilize the population in the absence of stochastic variation, while the same increase in the Sierra Nevada population would yield population growth of 4–5% per annum. A reduction in adult survival to 0.83 results in population decline in both cases.

Association between population density and reported incidence, characteristics and outcome after out-of-hospital cardiac arrest in Sweden.

PubMed

Strömsöe, A; Svensson, L; Claesson, A; Lindkvist, J; Lundström, A; Herlitz, J

2011-10-01

To describe the reported incidence of out of hospital cardiac arrest (OHCA) and the characteristics and outcome after OHCA in relation to population density in Sweden. All patients participating in the Swedish Cardiac Arrest Register between 2008 and 2009 in (a) 20 of 21 regions (n=6457) and in (b) 165 of 292 municipalities (n=3522) in Sweden, took part in the survey. The regional population density varied between 3 and 310 inhabitants per km(2) in 2009. In 2008-2009, the number of reported cardiac arrests varied between 13 and 52 per 100,000 inhabitants and year. Survival to 1 month varied between 2% and 14% during the same period in different regions. With regard to population density, based on municipalities, bystander CPR (p=0.04) as well as cardiac etiology (p=0.002) were more frequent in less populated areas. Ambulance response time was longer in less populated areas (p<0.0001). There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. However, bystander CPR, cardiac etiology and longer response times were more frequent in less populated areas. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Survival rate variation with different histological subtypes of poor prognostic male anal squamous cell carcinoma: a population-based study

PubMed Central

Rai, Kelash; Vikash, Sindhu; Chen, Liaobin; Li, Jingfeng

2017-01-01

Background and objective The prognosis of male anal squamous cell carcinoma (MASCC) and female anal squamous cell carcinoma (FASCC) is variable. The influence of tumor subtype on the survival rate and gender is poorly known. Our study is the largest population-based study and aims to outline the difference in survival between MASCC and FASCC patients. Methods A retrospective population-based study was performed to compare the disease-specific mortalities (DSMs) between genders related to the tumor subtypes. The Surveillance, Epidemiology, and End Results (SEER) program database was employed to obtain the data from January 1988 to December 2014. Results A total of 4,516, (3,249 males and 1,267 females), patients with anal squamous cell carcinomas (ASCC) were investigated. The 5-year DSMs were 24.18% and 18.08% for men and women, respectively. The univariate analysis of the male basaloid squamous cell carcinoma (BSCC) and cloacogenic carcinoma (CC) patients demonstrated higher DSMs (P <0.001). Moreover, in the multivariate analysis, BSCC and CC were associated with soaring DSMs in male patients (P < 0.05). Conclusions In the cohort of BSCC and CC patients, male patients demonstrated a considerable decrease in survival rate compared to females. A more precise classification of ASCC and individualized management for MASCC are warranted. PMID:29137429

Annual survival and recruitment in a Ruby-throated Hummingbird population, excluding the effect of transient individuals

USGS Publications Warehouse

Hilton, B.; Miller, M.W.

2003-01-01

We estimated annual apparent survival, recruitment, and rate of population growth of breeding Ruby-throated Hummingbirds (Archilochus colubris), while controlling for transients, by using 18 years of capture-mark-recapture data collected during 1984-2001 at Hilton Pond Center for Piedmont Natural History near York, South Carolina. Resident males had lower apparent survival (0.30 +/- 0.05 SE) than females (0.43 +/- 0.04). Estimates of apparent survival did not differ by age. Point estimates suggested that newly banded males were less likely than females to be residents, but standard errors of these estimates overlapped (males: 0.60 +/- 0.14 SE; females: 0.67 +/- 0.09). Estimated female recruitment was 0.60 +/- 0.06 SE, meaning that 60% of adult females present in any given year had entered the population during the previous year. Our estimate for rate of change indicated the population of female hummingbirds was stable during the study period (1.04 +/- 0.04 SE). We suggest an annual goal of greater than or equal to 64 adult females and greater than or equal to 64 immature females released per banding area to enable rigorous future tests for effects of covariates on population dynamics. Development of a broader cooperating network of hummingbird banders in eastern North America could allow tests for regional or metapopulation dynamics in this species.

Survival of elderly patients with multiple myeloma-Effect of upfront autologous stem cell transplantation.

PubMed

Merz, Maximilian; Jansen, Lina; Castro, Felipe A; Hillengass, Jens; Salwender, Hans; Weisel, Katja; Scheid, Christof; Luttmann, Sabine; Emrich, Katharina; Holleczek, Bernd; Katalinic, Alexander; Nennecke, Alice; Straka, Christian; Langer, Christian; Engelhardt, Monika; Einsele, Hermann; Kröger, Nicolaus; Beelen, Dietrich; Dreger, Peter; Brenner, Hermann; Goldschmidt, Hartmut

2016-07-01

The aim of this study was to determine the value of upfront autologous transplantation (ASCT) in elderly patients (60-79 years) with myeloma. We analysed relative survival (RS) of patients diagnosed in 1998-2011 and treated with ASCT within 12 months after diagnosis in Germany (n = 3591; German Registry of Stem Cell Transplantation) and compare RS with survival of myeloma patients diagnosed in the same years in Germany (n = 13,903; population-based German Cancer Registries). Utilisation of ASCT has increased rapidly between 2000-2002 and 2009-2011 (60-64years: 7.0-43.0%; 65-69 years: 6.6-23.7%; 70-79 years: 0.4-4.0%). Comparison of 5-year RS of patients from the general German myeloma population who have survived the first year after diagnosis with 5-year RS of patients treated with ASCT revealed higher survival for transplanted patients among all age groups (60-64: 59.2% versus 66.1%; 65-69: 57.4% versus 61.7%; 70-79: 51.0% versus 56.6%). RS increased strongly between 2003-2005 and 2009-2011 for the general German myeloma population (+8.5%) and for patients treated with ASCT (+11.8%). Differences in RS between these groups increased over time from +1.9% higher age-standardised survival in transplanted patients in 2003-2005 to 5.2% higher survival in 2009-2011. We conclude that upfront ASCT might be a major contributor to improved survival for elderly myeloma patients in Germany. Copyright © 2016 Elsevier Ltd. All rights reserved.

Animal Ownership Among Vulnerable Populations in Regional South Australia: Implications for Natural Disaster Preparedness and Resilience.

PubMed

Thompson, Kirrilly; Trigg, Joshua; Smith, Bradley

Few studies have examined the prevalence of animal ownership among populations likely to be at greater risk from disaster events within a bushfire context. To investigate the proportion of vulnerable community members keeping animals and the types of animals kept, as well as perceived risk of harm to pets, and their inclusion in bushfire survival planning. Statewide anonymous online survey in 2014 of adult South Australian animal owners threatened by bushfire in January 2014. Respondents were asked about animal ownership, their bushfire risk perception, and household survival planning. Descriptive statistics are presented for 5 groups considered likely to contribute to increased risk of harm for households: linguistically diverse, older adults, families with young children, physically frail, and self-identifying disabled, as well as individuals with mental health considerations. An opt-in purposively targeted sample of anonymous South Australians living in high fire-risk locations. Adult South Australian animal owners threatened or directly impacted by bushfire events, including individuals matching 1 of the 5 vulnerable groups. Self-reported details of animal ownership, perceived fire risk, survival planning, and vulnerability characteristics. Animal ownership was found to be more prevalent in these 5 populations than in the wider South Australian population. Perceived risk to pets was low to moderately low in these individuals. Variation was observed in the role of animals generally and pets specifically as motivators for preparing bushfire survival plans. Emergency services and associated agencies need to consider how the unique needs of vulnerable populations that keep animals, and their potential differences in risk perception, relate to their bushfire survival planning and preparedness requirements.

Adult brain cancer in the U.S. black population: a Surveillance, Epidemiology, and End Results (SEER) analysis of incidence, survival, and trends.

PubMed

Gabriel, Abigail; Batey, Jason; Capogreco, Joseph; Kimball, David; Walters, Andy; Tubbs, R Shane; Loukas, Marios

2014-08-25

Despite much epidemiological research on brain cancer in the United States, the etiology for the various subtypes remains elusive. The black population in the United States currently experiences lower incidence but higher survival rates when compared to other races. Thus, the aim of this study is to analyze the trends in incidence and survival for the 6 most common primary brain tumors in the black population of the United States. The Surveillance, Epidemiology, and End Results (SEER) database was utilized in this study to analyze the incidence and survival rates for the 6 most common brain tumor subtypes. Joinpoint 3.5.2 software was used to analyze trends in the incidence of diagnosis from 1973 to 2008. A Kaplan-Meier curve was generated to analyze mean time to death and survival at 60 months. Joinpoint analysis revealed that per year the incidence of brain cancer in the U.S. black population increased by 0.11 between 1973 and 1989. After this period, a moderate decrease by 0.06 per annum was observed from 1989 to 2008. Lymphoma was the most common primary tumor subtype for black individuals ages 20-34, and glioblastoma was identified as the most common tumor subtype for black individuals in the age groups of 35-49, 50-64, 65-79, and 80+. This population-based retrospective study of brain cancer in black adults in the United States revealed significant sex and age differences in the incidence of the 6 most common brain tumor subtypes from 1973 to 2008.

Identification of lactic acid bacteria in the feces of dairy cows fed whole crop maize silage to assess the survival of silage bacteria in the gut.

PubMed

Han, Hongyan; Wang, Chao; Li, Yanbing; Yu, Zhu; Xu, Qingfang; Li, Guangpeng; Minh, Tang Thuy; Nishino, Naoki

2018-01-01

In order to assess the survival of lactic acid bacteria (LAB) in whole crop maize silage in the gut of dairy cows, one representative silage sample and three different feces samples were collected from dairy cows on three dairy farms in Hua Bei, China and three dairy farms in Kyushu, Japan. The composition of the bacterial community was examined by denaturing gradient gel electrophoresis and quantitative polymerase chain reaction. Lactobacillus acetotolerans was detected in all bunker-made maize silage samples, regardless of the dairy farm or sampling region from which they were sourced. A total of eight LAB species were detected in the maize silage samples, of which three (L. acetotolerans, L. pontis and L. casei) appeared to survive digestion. The populations of L. acetotolerans in silage and feces were 10 6-7 and 10 3-4 copies/g, respectively, indicating that, even for the LAB species showing potential survival in the gut, competition in this niche may be harsh and the population may substantially decrease during the digestion process. It may be difficult for silage LAB to survive in the gut of silage-fed dairy cows, because marked decrease in population can take place during the digestion process, even for surviving species. © 2017 Japanese Society of Animal Science.

Crash and rebound of indigenous populations in lowland South America

NASA Astrophysics Data System (ADS)

Hamilton, Marcus J.; Walker, Robert S.; Kesler, Dylan C.

2014-04-01

Lowland South America has long been a battle-ground between European colonization and indigenous survival. Initial waves of European colonization brought disease epidemics, slavery, and violence that had catastrophic impacts on indigenous cultures. In this paper we focus on the demography of 238 surviving populations in Brazil. We use longitudinal censuses from all known indigenous Brazilian societies to quantify three demographic metrics: 1) effects of European contact on indigenous populations; 2) empirical estimates of minimum viable population sizes; and 3) estimates of post-contact population growth rates. We use this information to conduct population viability analysis (PVA). Our results show that all surviving populations suffered extensive mortality during, and shortly after, contact. However, most surviving populations exhibit positive growth rates within the first decade post-contact. Our findings paint a positive demographic outlook for these indigenous populations, though long-term survival remains subject to powerful externalities, including politics, economics, and the pervasive illegal exploitation of indigenous lands.

Sex-based differences in veterans with pulmonary hypertension: Results from the veterans affairs-clinical assessment reporting and tracking database.

PubMed

Ventetuolo, Corey E; Hess, Edward; Austin, Eric D; Barón, Anna E; Klinger, James R; Lahm, Tim; Maddox, Thomas M; Plomondon, Mary E; Thompson, Lauren; Zamanian, Roham T; Choudhary, Gaurav; Maron, Bradley A

2017-01-01

Women have an increased risk of pulmonary hypertension (PH) but better survival compared to men. Few studies have explored sex-based differences in population-based cohorts with PH. We sought to determine whether sex was associated with hemodynamics and survival in US veterans with PH (mean pulmonary artery pressure [mPAP] ≥ 25 mm Hg) from the Veterans Affairs Clinical Assessment, Reporting, and Tracking database. The relationship between sex and hemodynamics was assessed with multivariable linear mixed modeling. Cox proportional hazards models were used to compare survival by sex for those with PH and precapillary PH (mPAP ≥ 25 mm Hg, pulmonary artery wedge pressure [PAWP] ≤ 15 mm Hg and pulmonary vascular resistance [PVR] > 3 Wood units) respectively. The study population included 15,464 veterans with PH, 516 (3%) of whom were women; 1,942 patients (13%) had precapillary PH, of whom 120 (6%) were women. Among those with PH, women had higher PVR and pulmonary artery pulse pressure, and lower right atrial pressure and PAWP (all p <0.001) compared with men. There were no significant differences in hemodynamics according to sex in veterans with precapillary PH. Women with PH had 18% greater survival compared to men with PH (adjusted HR 0.82, 95% CI 0.69-0.97, p = 0.020). Similarly, women with precapillary PH were 29% more likely to survive as compared to men with PH (adjusted HR 0.71, 95% CI 0.52-0.98, p = 0.040). In conclusion, female veterans with PH have better survival than males despite higher pulmonary afterload.

Survival of high-risk pediatric neuroblastoma patients in a developing country.

PubMed

Easton, Joseph C; Gomez, Sergio; Asdahl, Peter H; Conner, J Michael; Fynn, Alcira B; Ruiz, Claudia; Ojha, Rohit P

2016-09-01

Little information is available about survival of high-risk pediatric neuroblastoma patients in developing countries. We aimed to assess survival among high-risk pediatric neuroblastoma patients in La Plata, Argentina. Individuals eligible for our cohort were aged <20 yr when diagnosed with high-risk neuroblastoma and received cancer-directed therapy including stem cell transplantation at Hospital de Niños Sor Maria Ludovica between February 1999 and February 2015. We estimated overall survival probabilities using an extended Kaplan-Meier approach. Our study population comprised 39 high-risk neuroblastoma patients, of whom 39% were aged >4 yr at diagnosis, 54% were male, and 62% had adrenal neuroblastoma. We observed 18 deaths, and the median survival time of our study population was 1.7 yr. The five-yr overall survival probability was 24% (95% CL: 10%, 41%). In contrast, five-yr survival of high-risk neuroblastoma patients ranges between 23% and 76% in developed countries. Survival among high-risk neuroblastoma patients is generally poor regardless of geographic location, but our results illustrate dramatically worse survival for patients in a developing country. We speculate that the observed survival differences could be attenuated or eliminated with improvements in treatment and supportive care, but addressing these issues will require creative solutions because of resource limitations. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sex- and age-dependent patterns of survival and breeding success in a long-lived endangered avian scavenger

NASA Astrophysics Data System (ADS)

Sanz-Aguilar, Ana; Cortés-Avizanda, Ainara; Serrano, David; Blanco, Guillermo; Ceballos, Olga; Grande, Juan M.; Tella, José L.; Donázar, José A.

2017-01-01

In long-lived species, the age-, stage- and/or sex-dependent patterns of survival and reproduction determine the evolution of life history strategies, the shape of the reproductive value, and ultimately population dynamics. We evaluate the combined effects of age and sex in recruitment, breeder survival and breeding success of the globally endangered Egyptian vulture (Neophron percnopterus), using 31-years of exhaustive data on marked individuals in Spain. Mean age of first reproduction was 7-yrs for both sexes, but females showed an earlier median and a larger variance than males. We found an age-related improvement in breeding success at the population level responding to the selective appearance and disappearance of phenotypes of different quality but unrelated to within-individual aging effects. Old males (≥8 yrs) showed a higher survival than both young males (≤7 yrs) and females, these later in turn not showing aging effects. Evolutionary trade-offs between age of recruitment and fitness (probably related to costs of territory acquisition and defense) as well as human-related mortality may explain these findings. Sex- and age-related differences in foraging strategies and susceptibility to toxics could be behind the relatively low survival of females and young males, adding a new concern for the conservation of this endangered species.

A Population-Based Observational Study of First-Course Treatment and Survival for Adolescent and Young Adult Females with Breast Cancer

PubMed Central

DeRouen, Mindy C.; Gomez, Scarlett L.; Press, David J.; Tao, Li; Kurian, Allison W.

2013-01-01

Purpose Young age at breast cancer diagnosis is associated with poor survival. However, little is known about factors associated with first-course treatment receipt or survival among adolescent and young adult (AYA) females aged 15–39 years. Methods Data regarding 19,906 eligible AYA breast cancers diagnosed in California during 1992–2009 were obtained from the population-based California Cancer Registry. Multivariable logistic regression was used to evaluate clinical and sociodemographic differences in treatment receipt. Multivariable Cox proportional hazards regression was used to examine differences in survival by initial treatment, and by patient and tumor characteristics. Results Black and Hispanic AYAs diagnosed with in situ or stages I–III breast cancer were more likely than White AYAs to receive breast-conserving surgery (BCS) without radiation; Asian and Hispanic AYAs were more likely than Whites to receive mastectomy. Women in lower socioeconomic status (SES) neighborhoods were more likely to omit radiation after BCS, more likely to receive mastectomy, and less likely to receive chemotherapy, compared to those in higher SES neighborhoods. Among patients with invasive disease, survival improved an average of 5% per year during 1992–2009. AYAs who received BCS with radiation experienced better survival than other surgery/radiation options. Black AYAs had poorer survival than Whites. AYAs who resided in higher SES neighborhoods had better survival. Conclusions Treatment receipt among AYAs with breast cancer varied by race/ethnicity and neighborhood SES. Poor survival for Black AYAs and AYAs living in low SES neighborhoods in models adjusted for treatment receipt suggests that factors other than treatment may also be important to disease outcome. PMID:24066271

Nest visits and capture events affect breeding success of Yellow-billed and Pacific loons

USGS Publications Warehouse

Uher-Koch, Brian D.; Schmutz, Joel A.; Wright, Kenneth G.

2015-01-01

Accurate estimates of breeding success are essential for understanding population dynamics and for managing populations. Unfortunately, research activities to collect these data can negatively impact the breeding success of the study species and bias estimates of breeding success. Despite the potential for negative impacts, few studies have documented the effect of capturing incubating adults on nest survival or compared nest survival following different capture methods. In this study we evaluate the impacts of investigator disturbance associated with captures and nest visits on nest survival of Yellow-billed Loons (Gavia adamsii) and Pacific Loons (Gavia pacifica) in the National Petroleum Reserve-Alaska (NPR-A), an area of conservation concern, in 2011–2013. In an effort to reduce capture-related nest failures, we developed a new suspended dive net technique to catch territorial aquatic birds while off their nests. We then compared nest survival following suspended dive net captures to bow-net trap captures of breeding adult loons. Daily nest survival following bow-net trap or suspended dive net capture was about 30% lower than when adults were not captured. The effect of captures on nest survival was similar between bow-net trap and suspended dive net capture methods. Nest visits without captures also negatively impacted nest survival, although less than captures. If not accounted for, nest visitation biased daily survival rates of nests downward 6%. Effects of investigator disturbance did not differ by species or between years. Our results suggest that any source of disturbance that displaces incubating adult loons could potentially reduce nest survival. To maximize breeding success, human disturbance factors should be limited near loon nests.

Accurate computation of survival statistics in genome-wide studies.

PubMed

Vandin, Fabio; Papoutsaki, Alexandra; Raphael, Benjamin J; Upfal, Eli

2015-05-01

A key challenge in genomics is to identify genetic variants that distinguish patients with different survival time following diagnosis or treatment. While the log-rank test is widely used for this purpose, nearly all implementations of the log-rank test rely on an asymptotic approximation that is not appropriate in many genomics applications. This is because: the two populations determined by a genetic variant may have very different sizes; and the evaluation of many possible variants demands highly accurate computation of very small p-values. We demonstrate this problem for cancer genomics data where the standard log-rank test leads to many false positive associations between somatic mutations and survival time. We develop and analyze a novel algorithm, Exact Log-rank Test (ExaLT), that accurately computes the p-value of the log-rank statistic under an exact distribution that is appropriate for any size populations. We demonstrate the advantages of ExaLT on data from published cancer genomics studies, finding significant differences from the reported p-values. We analyze somatic mutations in six cancer types from The Cancer Genome Atlas (TCGA), finding mutations with known association to survival as well as several novel associations. In contrast, standard implementations of the log-rank test report dozens-hundreds of likely false positive associations as more significant than these known associations.

Accurate Computation of Survival Statistics in Genome-Wide Studies

PubMed Central

Vandin, Fabio; Papoutsaki, Alexandra; Raphael, Benjamin J.; Upfal, Eli

2015-01-01

A key challenge in genomics is to identify genetic variants that distinguish patients with different survival time following diagnosis or treatment. While the log-rank test is widely used for this purpose, nearly all implementations of the log-rank test rely on an asymptotic approximation that is not appropriate in many genomics applications. This is because: the two populations determined by a genetic variant may have very different sizes; and the evaluation of many possible variants demands highly accurate computation of very small p-values. We demonstrate this problem for cancer genomics data where the standard log-rank test leads to many false positive associations between somatic mutations and survival time. We develop and analyze a novel algorithm, Exact Log-rank Test (ExaLT), that accurately computes the p-value of the log-rank statistic under an exact distribution that is appropriate for any size populations. We demonstrate the advantages of ExaLT on data from published cancer genomics studies, finding significant differences from the reported p-values. We analyze somatic mutations in six cancer types from The Cancer Genome Atlas (TCGA), finding mutations with known association to survival as well as several novel associations. In contrast, standard implementations of the log-rank test report dozens-hundreds of likely false positive associations as more significant than these known associations. PMID:25950620

Childhood cancer survival in Switzerland (1976-2013): Time-trends and predictors.

PubMed

Schindler, Matthias; Belle, Fabiën N; Grotzer, Michael A; von der Weid, Nicolas X; Kuehni, Claudia E

2017-01-01

Population-based studies on childhood cancer survival are key to monitor progress against cancer and to detect potential differences between regions and other subgroups in the population. We investigated time trends and factors associated with childhood cancer survival on a national level in Switzerland, from 1976 to 2013. We extracted data from the population-based Swiss Childhood Cancer Registry of 5,776 children (age 0-14 years) diagnosed with cancer from 1985 to 2014 in Switzerland. We calculated age-adjusted 5-year survival, defined the annual reduction in risk of death (ARR), and explored associations of survival with clinical and demographic factors. Overall, 5-year survival improved significantly, from 64% in 1976-1983 to 88% in 2004-2013. ARR over the whole period was 4% for all diagnostic groups, greatest for Hodgkin lymphomas (8%), ependymomas (6%), Burkitt's lymphomas (6%) and germ cell tumours (6%). Children treated in hospitals without specialised paediatric cancer centre for leukaemia (HR 12.9), lymphoma (HR 5.0) and neuroblastoma (HR 3.7) were at higher risk of death. In French-speaking Switzerland, risk of death was lower for lymphoma (HR 0.6), CNS tumours (HR 0.7) and neuroblastoma (HR 0.5). Children with migration background had a higher risk of death from all tumours except bone tumours. Childhood cancer survival significantly improved from 1976 to 2013, but there is room for further improvement. Survival rates varied by type of clinical treatment, language region and nationality. All paediatric cancer patients should be referred to a specialised paediatric cancer centre. Further research is needed to intervene and completely eliminate inequalities in survival. © 2016 UICC.

Population-specific demographic estimates provide insights into declines of Lark Buntings (Calamospiza melanocorys)

USGS Publications Warehouse

Yackel Adams, A.A.; Skagen, S.K.; Savidge, J.A.

2007-01-01

Many North American prairie bird populations have recently declined, and the causes of these declines remain largely unknown. To determine whether population limitation occurs during breeding, we evaluated the stability of a population of prairie birds using population-specific values for fecundity and postfledging survival. During 2001-2003, we radiomarked 67 female Lark Buntings (Calamospiza melanocorys) to determine annual fecundity and evaluate contributing factors such as nest survival and breeding response (number of breeding attempts and dispersal). Collectively, 67 females built 112 nests (1.67 ± 0.07 nests female−1 season−1; range: 1–3); 34 were second nests and 11 were third nests. Daily nest survival estimates were similar for initial and later nests with overall nest survival (DSR19) of 30.7% and 31.7%, respectively. Nest predation was the most common cause of failure (92%). Capture and radiomarking of females did not affect nest survival. Lark Bunting dispersal probabilities increased among females that fledged young from initial nests and females that lost their original nests late in the season. Conservative and liberal estimates of mean annual fecundity were 0.96 ±0.11 and 1.24 ± 0.09 female offspring per female, respectively. Given the fecundity and juvenile-survival estimates for this population, annual adult survival values of 71–77% are necessary to achieve a stable population. Because adult survival of prairie passerines ranges between 55% and 65%, this study area may not be capable of sustaining a stable population in the absence of immigration. We contrast our population assessment with one that assumes indirect values of fecundity and juvenile survival. To elucidate limiting factors, estimation of population-specific demographic parameters is desirable. We present an approach for selecting species and areas for evaluation of population stability.

Overall mortality among patients surviving an episode of peptic ulcer bleeding

PubMed Central

Ruigomez, A.; Rodriguez, L. A.; Hasselgren, G.; Johansson, S.; Wallander, M.

2000-01-01

STUDY OBJECTIVE—The authors investigated whether patients who have survived an acute episode of peptic ulcer bleeding (PUB) have an excess long term all cause mortality compared with the general population free of PUB.
DESIGN—Follow up study of previously identified cohort of patients with a PUB episode and a general population cohort.
SETTING—The source population included all people aged 30 to 89 years, registered with general practitioners in the United Kingdom.
PATIENTS—All patients alive one month after the PUB episode constituted the cohort of PUB patients (n=978). A control group of 5000 people was randomly sampled from the source population. The same eligibility criteria as for patients with PUB were applied to the control series. Also, controls had to be free of PUB before start date.
MAIN RESULTS—Relative risk of mortality among PUB patients was 2.1, 95%CI: 1.7, 2.6) compared with the general population. This increased mortality risk occurred mainly in the patients less than 60 years old. No difference was observed between men and women. The excess mortality was not only circumscribed to deaths attributable to recurrent gastrointestinal bleed, but also cardiovascular, cancer and other causes.
CONCLUSIONS—People who have survived an acute episode of PUB have a reduced long term survival compared with the general population.This reduction was stronger among middle age patients than in the elderly.


Keywords: cohort study; mortality; peptic ulcer; bleeding; population-based study PMID:10715746

Effect of water temperature and population density on the population dynamics of Schistosoma mansoni intermediate host snails.

PubMed

McCreesh, Nicky; Arinaitwe, Moses; Arineitwe, Wilber; Tukahebwa, Edridah M; Booth, Mark

2014-11-12

Mathematical models can be used to identify areas at risk of increased or new schistosomiasis transmission as a result of climate change. The results of these models can be very different when parameterised to different species of host snail, which have varying temperature preferences. Currently, the experimental data needed by these models are available for only a few species of snail. The choice of density-dependent functions can also affect model results, but the effects of increasing densities on Biomphalaria populations have only previously been investigated in artificial aquariums. Laboratory experiments were conducted to estimate Biomphalaria sudanica mortality, fecundity and growth rates at ten different constant water temperatures, ranging from 13-32°C. Snail cages were used to determine the effects of snail densities on B. sudanica and B. stanleyi mortality and fecundity rates in semi-natural conditions in Lake Albert. B. sudanica survival and fecundity were highest at 20°C and 22°C respectively. Growth in shell diameter was estimated to be highest at 23°C in small and medium sized snails, but the relationship between temperature and growth was not clear. The fecundity of both B. sudanica and B. stanleyi decreased by 72-75% with a four-fold increase in population density. Increasing densities four-fold also doubled B. stanleyi mortality rates, but had no effect on the survival of B. sudanica. The optimum temperature for fecundity was lower for B. sudanica than for previously studied species of Biomphalaria. In contrast to other Biomphalaria species, B. sudanica have a distinct peak temperature for survival, as opposed to a plateau of highly suitable temperatures. For both B. stanleyi and B. sudanica, fecundity decreased with increasing population densities. This means that snail populations may experience large fluctuations in numbers, even in the absence of any external factors such as seasonal temperature changes. Survival also decreased with increasing density for B. stanleyi, in contrast to B. sudanica and other studied Biomphalaria species where only fecundity has been shown to decrease.

Effects of livestock exclusion on density, survival and biomass of the perennial sagebrush grass Hymenachne pernambucense (Poaceae) from a temperate fluvial wetland

NASA Astrophysics Data System (ADS)

Magnano, Andrea L.; Nanni, Analía S.; Krug, Pamela; Astrada, Elizabeth; Vicari, Ricardo; Quintana, Rubén D.

2018-01-01

In Argentina, the intensification of soybean production has displaced a substantial proportion of cattle ranching to fluvial wetlands such as those in the Delta of the Paraná River. Cattle grazing affects structure and dynamics of native forage plants but there is little information on this impact in populations from fluvial wetlands. This study addresses the effect of cattle ranching on density, survival, mean life-span and aerial biomass of Hymenachne pernambucense (Poaceae), an important forage species in the region. The study was carried out monthly for one year in permanents plots subject to continuous grazing and plots excluded from grazing in the Middle Delta of the Paraná River. In plots excluded from grazing, tillers showed significantly higher population density and survival, and a two-fold increase in mean life-span, while continuous grazing decreased survival of cohorts. The largest contribution to tiller density in ungrazed and grazed populations was made by spring and summer cohorts, respectively. Total and green biomass were significantly higher in the ungrazed population, with highest differences in late spring-early summer. Cattle grazing affected the relationship between tiller density and green biomass suggesting that cattle prefer sprouts because they are more palatable and nutritious than older tissue.

Survival and health in liveborn infants with transposition of great arteries--a population-based study.

PubMed

Garne, Ester; Loane, Maria A; Nelen, Vera; Bakker, Marian K; Gener, Blanca; Abramsky, Lenore; Addor, Marie-Claude; Queisser-Luft, Annette

2007-01-01

To describe treatment, survival, and morbidity for liveborn infants with isolated transposition of great arteries (TGA). Population-based data from 7 European registries of congenital malformations (EUROCAT). Ninety-seven infants were diagnosed with isolated TGA and livebirth prevalence was 2.0 per 10,000 livebirths. The majority of infants were treated with prostaglandins (83%) and 57% had a catheter atrial septostomia performed. Arterial switch surgery was performed in 78 infants, other or unknown type of surgery was performed in 3 cases, and for 6 infants there was no information on surgery. At 1 year of age 69 infants were alive (71%) and 24 (25%) were dead (4 unknown). There were 10 deaths before surgery and 58% of all deaths took place during the first week. There was no statistically significant regional difference in mortality. Eight infants diagnosed prenatally all survived to 1 year and only 71% of infants diagnosed after birth survived (P = 0.08). Data on morbidity at 1 year of age was available for 57 infants. Fifty-one infants were reported with normal health and development. In this population-based study survival for liveborn infants with TGA is lower than in studies published from tertiary centers. Outcome for survivors at 1 year of age seems favorable.

Population Response to Habitat Fragmentation in a Stream-Dwelling Brook Trout Population

PubMed Central

Letcher, Benjamin H.; Nislow, Keith H.; Coombs, Jason A.; O'Donnell, Matthew J.; Dubreuil, Todd L.

2007-01-01

Fragmentation can strongly influence population persistence and expression of life-history strategies in spatially-structured populations. In this study, we directly estimated size-specific dispersal, growth, and survival of stream-dwelling brook trout in a stream network with connected and naturally-isolated tributaries. We used multiple-generation, individual-based data to develop and parameterize a size-class and location-based population projection model, allowing us to test effects of fragmentation on population dynamics at local (i.e., subpopulation) and system-wide (i.e., metapopulation) scales, and to identify demographic rates which influence the persistence of isolated and fragmented populations. In the naturally-isolated tributary, persistence was associated with higher early juvenile survival (∼45% greater), shorter generation time (one-half) and strong selection against large body size compared to the open system, resulting in a stage-distribution skewed towards younger, smaller fish. Simulating barriers to upstream migration into two currently-connected tributary populations caused rapid (2–6 generations) local extinction. These local extinctions in turn increased the likelihood of system-wide extinction, as tributaries could no longer function as population sources. Extinction could be prevented in the open system if sufficient immigrants from downstream areas were available, but the influx of individuals necessary to counteract fragmentation effects was high (7–46% of the total population annually). In the absence of sufficient immigration, a demographic change (higher early survival characteristic of the isolated tributary) was also sufficient to rescue the population from fragmentation, suggesting that the observed differences in size distributions between the naturally-isolated and open system may reflect an evolutionary response to isolation. Combined with strong genetic divergence between the isolated tributary and open system, these results suggest that local adaptation can ‘rescue’ isolated populations, particularly in one-dimensional stream networks where both natural and anthropogenically-mediated isolation is common. However, whether rescue will occur before extinction depends critically on the race between adaptation and reduced survival in response to fragmentation. PMID:18188404

Population response to habitat fragmentation in a stream-dwelling brook trout population

USGS Publications Warehouse

Letcher, B.H.; Nislow, K.H.; Coombs, J.A.; O'Donnell, M. J.; Dubreuil, T.L.

2007-01-01

Fragmentation can strongly influence population persistence and expression of life-history strategies in spatially-structured populations. In this study, we directly estimated size-specific dispersal, growth, and survival of stream-dwelling brook trout in a stream network with connected and naturally-isolated tributaries. We used multiple-generation, individual-based data to develop and parameterize a size-class and location-based population projection model, allowing us to test effects of fragmentation on population dynamics at local (i.e., subpopulation) and system-wide (i.e., metapopulation) scales, and to identify demographic rates which influence the persistence of isolated and fragmented populations. In the naturally-isolated tributary, persistence was associated with higher early juvenile survival (-45% greater), shorter generation time (one-half) and strong selection against large body size compared to the open system, resulting in a stage-distribution skewed towards younger, smaller fish. Simulating barriers to upstream migration into two currently-connected tribuory populations caused rapid (2-6 generations) local extinction. These local extinctions in turn increased the likelihood of system-wide extinction, as tributaries could no longer function as population sources. Extinction could be prevented in the open system if sufficient immigrants from downstream areas were available, but the influx of individuals necessary to counteract fragmentation effects was high (7-46% of the total population annually). In the absence of sufficient immigration, a demographic change (higher early survival characteristic of the isolated tributary) was also sufficient to rescue the population from fragmentation, suggesting that the observed differences in size distributions between the naturally-isolated and open system may reflect an evolutionary response to isolation. Combined with strong genetic divergence between the isolated tributary and open system, these results suggest that local adaptation can 'rescue' isolated populations, particularly in one-dimensional stream networks where both natural and anthropegenically-mediated isolation is common. However, whether rescue will occur before extinction depends critically on the race between adaptation and reduced survival in response to fragmentation.

Field-evolved resistance to λ-cyhalothrin in the lady beetle Eriopis connexa.

PubMed

Costa, P M G; Torres, J B; Rondelli, V M; Lira, R

2018-06-01

Natural enemies are exposed to insecticide sprays for herbivorous species and may evolve field resistance to insecticides. Natural enemies selected for resistance in the field, however, are welcome for pest control. The susceptibility of 20 populations of Eriopis connexa from various crop ecosystems to λ-cyhalothrin was tested. Three bioassays were conducted: (i) topical treatment with lethal dose (LD)50 previously determined for populations considered standard for susceptibility (LD50S) and for resistance (LD50R) to λ-cyhalothrin at technical grade; (ii) dose-mortality assay to calculate the LD for populations exhibiting significant survival to the LD50R; and (iii) determination of survival when exposed to dried residues at field rates. Among the 20 tested populations, seven populations did not survive or survival rates were lower than 10% when treated with LD50R; three populations survived >20%, but lower than 50%; while ten populations exhibited equal or greater survival rates compared with the 50% expected survival for the LD50R. Thus, these ten populations were subjected to dose-mortality response, and the LD50 values varied from 0.046 to 5.44 µg a.i./insect with resistance ratio of 8.52- to 884.08-folds. Adults from these ten populations that were ranked as resistant according to the LD50R exhibited survival from 44.5 to 100% exposed to the lowest and from 38.8 to 100% exposed to the highest field rates of λ-cyhalothrin, respectively. Otherwise, the remaining ten populations ranked as susceptible according to the LD50R showed survival from 3.3 to 56% exposed to the lowest and from 0 to 17.7% exposed to the highest field rates of λ-cyhalothrin, respectively. Therefore, 50% of the tested E. connexa populations exhibited field-evolved resistance to λ-cyhalothrin and the use of a discriminatory LD50 for resistance matched the survival obtained when exposed to the insecticide field rates.

Effects of amphibian chytrid fungus on individual survival probability in wild boreal toads

USGS Publications Warehouse

Pilliod, D.S.; Muths, E.; Scherer, R. D.; Bartelt, P.E.; Corn, P.S.; Hossack, B.R.; Lambert, B.A.; Mccaffery, R.; Gaughan, C.

2010-01-01

Chytridiomycosis is linked to the worldwide decline of amphibians, yet little is known about the demographic effects of the disease. We collected capture-recapture data on three populations of boreal toads (Bufo boreas [Bufo = Anaxyrus]) in the Rocky Mountains (U.S.A.). Two of the populations were infected with chytridiomycosis and one was not. We examined the effect of the presence of amphibian chytrid fungus (Batrachochytrium dendrobatidis [Bd]; the agent of chytridiomycosis) on survival probability and population growth rate. Toads that were infected with Bd had lower average annual survival probability than uninfected individuals at sites where Bd was detected, which suggests chytridiomycosis may reduce survival by 31-42% in wild boreal toads. Toads that were negative for Bd at infected sites had survival probabilities comparable to toads at the uninfected site. Evidence that environmental covariates (particularly cold temperatures during the breeding season) influenced toad survival was weak. The number of individuals in diseased populations declined by 5-7%/year over the 6 years of the study, whereas the uninfected population had comparatively stable population growth. Our data suggest that the presence of Bd in these toad populations is not causing rapid population declines. Rather, chytridiomycosis appears to be functioning as a low-level, chronic disease whereby some infected individuals survive but the overall population effects are still negative. Our results show that some amphibian populations may be coexisting with Bd and highlight the importance of quantitative assessments of survival in diseased animal populations. Journal compilation. ?? 2010 Society for Conservation Biology. No claim to original US government works.

Harvesting, predation and competition effects on a red coral population

NASA Astrophysics Data System (ADS)

Abbiati, M.; Buffoni, G.; Caforio, G.; Di Cola, G.; Santangelo, G.

A Corallium rubrum population, dwelling in the Ligurian Sea, has been under observation since 1987. Biometric descriptors of colonies (base diameter, weight, number of polyps, number of growth rings) have been recorded and correlated. The population size structure was obtained by distributing the colonies into diameter classes, each size class representing the average annual increment of diameter growth. The population was divided into ten classes, including a recruitment class. This size structure showed a fairly regular trend in the first four classes. The irregularity of survival in the older classes agreed with field observations on harvesting and predation. Demographic parameters such as survival, growth plasticity and natality coefficients were estimated from the experimental data. On this basis a discrete nonlinear model was implemented. The model is based on a kind of density-dependent Leslie matrix, where the feedback term only occurs in survival of the first class; the recruitment function is assumed to be dependent on the total biomass and related to inhibiting effects due to competitive interactions. Stability analysis was applied to steady-state solutions. Numerical simulations of population evolution were carried out under different conditions. The dynamics of settlement and the effects of disturbances such as harvesting, predation and environmental variability were studied.

The impact of the Catechol-O-methyltransferase Val158Met polymorphism on survival in the general population – the HUNT study

PubMed Central

Hagen, Knut; Stovner, Lars J; Skorpen, Frank; Pettersen, Elin; Zwart, John-Anker

2007-01-01

Background The catechol-O-methyltransferase (COMT) gene contains a functional polymorphism, Val158Met which has been related to common diseases like cancer, psychiatric illness and myocardial infarction. Whether the Val158Met polymorphism is associated with survival has not been evaluated in the general population. The aim of this prospective study was to evaluate the impact of codon 158 COMT gene polymorphism on survival in a population-based cohort. Methods The sample comprised 2979 non-diabetic individuals who participated in the Nord-Trøndelag Health Study (HUNT) in the period 1995–97. The subjects were followed up with respect to mortality throughout year 2004. Results 212 men and 183 women died during the follow up. No association between codon 158 COMT gene polymorphism and survival was found. The unadjusted relative risk of death by non-ischemic heart diseases with Met/Met or Met/Val genotypes was 3.27 (95% confidence interval, 1.19–9.00) compared to Val/Val genotype. When we adjusted for age, gender, smoking, coffee intake and body mass index the relative risk decreased to 2.89 (95% confidence interval, 1.04–8.00). Conclusion During 10 year of follow-up, the Val158Met polymorphism had no impact on survival in a general population. Difference in mortality rates from non-ischemic heart diseases may be incidental and should be evaluated in other studies. PMID:17577421

The rare peat moss Sphagnum wulfianum (Sphagnaceae) did not survive the last glacial period in northern European refugia.

PubMed

Kyrkjeeide, Magni Olsen; Hassel, Kristian; Flatberg, Kjell I; Stenøien, Hans K

2012-04-01

Organisms may survive unfavorable conditions either by moving to more favorable areas by means of dispersal or by adapting to stressful environments. Pleistocene glacial periods represent extremely unfavorable conditions for the majority of life forms, especially sessile organisms. Many studies have revealed placements of refugial areas and postglacial colonization patterns of seed plants, but little is still known about areas of long-term survival and historical migration routes of bryophytes. Given overall differences in stress tolerance between seed plants and bryophytes, it is of interest to know whether bryophytes have survived periods of extreme climatic conditions better then seed plants in northern areas. The haploid and rarely spore-producing peat moss Sphagnum wulfianum is mostly found in areas that were covered by ice during the last glacial maximum. Twelve microsatellite markers were amplified from 43 populations (367 shoots) of this species, and data were analyzed using population genetic diversity statistics, Bayesian clustering methods, and coalescence-based inference tools to estimate historical and demographic parameters. Genetic diversity within populations was low, but populations were highly differentiated, with two main genetic clusters being recognized. The two main genetic groups have diverged quite recently in the Holocene, and the pattern of genetic variability and structuring gives no support for survival in Scandinavian refugia during the last glacial period in this species. The dispersal ability of this plant thus seems surprisingly high despite its infrequent spore production.

Linking Resilience of Aquatic Species to Watershed Condition

NASA Astrophysics Data System (ADS)

Flitcroft, R. L.

2017-12-01

Watershed condition means different things to different people. From the perspective of aquatic ecology, watershed condition may be interpreted to mean the capacity of a watershed to support life history diversity of native species. Diversity in expression of life history is thought to confer resilience allowing portions of the broader population to survive stressful conditions. Different species have different life history strategies, many of which were developed through adaptation to regional or local environmental conditions and natural disturbance regimes. By reviewing adaptation strategies for species of interest at regional scales, characteristics of watersheds that confer resilience may be determined. Such assessments must be completed at multiple levels of spatial organization (i.e. sub-watershed, watershed, region) allowing assessments to be inferred across broad spatial extents. In a project on the Wenatchee River watershed, we guided models of wildfire effects on bull trout and spring Chinook from a meta-population perspective to determine risks to survival at local and population scales over multiple extents of spatial organization. In other work in the Oregon Coast Range, we found that historic landslides continue to exert habitat-forming pressure at local scales, leading to patchiness in distribution of habitats for different life stages of coho salmon. Further, climate change work in Oregon estuaries identified different vulnerabilities in terms of juvenile rearing habitat depending on the species of interest and the intensity of future changes in climate. All of these studies point to the importance of considering physical conditions in watersheds at multiple spatial extents from the perspective of native aquatic species in order to understand risks to long-term survival. The broader implications of watershed condition, from this perspective, is the determination of physical attributes that confer resilience to native biota. This may require regionally specific metrics, and across-species synthesis of survival strategies and environmental conditions that confer resilience.

Long-Term Effects of Tetanus Toxoid Inoculation on the Demography and Life Expectancy of the Cayo Santiago Rhesus Macaques

PubMed Central

KESSLER, MATTHEW J.; PACHECO, RAISA HERNÁNDEZ; RAWLINS, RICHARD G.; RUIZ-LAMBRIDES, ANGELINA; DELGADO, DIANA L.; SABAT, ALBERTO M.

2014-01-01

Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys on Cayo Santiago prior to 1985 when the entire colony was given its first dose of tetanus toxoid. The immediate reduction in mortality that followed tetanus toxoid inoculation (TTI) has been documented, but the long-term demographic effects of eliminating tetanus infections have not. This study uses the Cayo Santiago demographic database to construct comparative life tables 12 years before, and 12 years after, TTI. Life tables and matrix projection models are used to test for differences in: (i) survival among all individuals as well as among social groups, (ii) long-term fitness of the population, (iii) age distribution, (iv) reproductive value, and (v) life expectancy. A retrospective life table response experiment (LTRE) was performed to determine which life cycle transition contributed most to observed changes in long-term fitness of the population post-TTI. Elimination of clinical tetanus infections through mass inoculation improved the health and well-being of the monkeys. It also profoundly affected the population by increasing survivorship and long-term fitness, decreasing the differences in survival rates among social groups, shifting the population’s age distribution towards older individuals, and increasing reproductive value and life expectancy. These findings are significant because they demonstrate the long-term effects of eradicating a major cause of mortality at a single point in time on survival, reproduction, and overall demography of a naturalistic population of primates. PMID:25230585

Long-term effects of tetanus toxoid inoculation on the demography and life expectancy of the Cayo Santiago rhesus macaques.

PubMed

Kessler, Matthew J; Hernández Pacheco, Raisa; Rawlins, Richard G; Ruiz-Lambrides, Angelina; Delgado, Diana L; Sabat, Alberto M

2015-02-01

Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys on Cayo Santiago prior to 1985 when the entire colony was given its first dose of tetanus toxoid. The immediate reduction in mortality that followed tetanus toxoid inoculation (TTI) has been documented, but the long-term demographic effects of eliminating tetanus infections have not. This study uses the Cayo Santiago demographic database to construct comparative life tables 12 years before, and 12 years after, TTI. Life tables and matrix projection models are used to test for differences in: (i) survival among all individuals as well as among social groups, (ii) long-term fitness of the population, (iii) age distribution, (iv) reproductive value, and (v) life expectancy. A retrospective life table response experiment (LTRE) was performed to determine which life cycle transition contributed most to observed changes in long-term fitness of the population post-TTI. Elimination of clinical tetanus infections through mass inoculation improved the health and well-being of the monkeys. It also profoundly affected the population by increasing survivorship and long-term fitness, decreasing the differences in survival rates among social groups, shifting the population's age distribution towards older individuals, and increasing reproductive value and life expectancy. These findings are significant because they demonstrate the long-term effects of eradicating a major cause of mortality at a single point in time on survival, reproduction, and overall demography of a naturalistic population of primates. © 2014 Wiley Periodicals, Inc.

Survival Disparities within American and Israeli Dialysis Populations: Learning from Similarities and Distinctions across Race and Ethnicity

PubMed Central

Kalantar-Zadeh, Kamyar; Golan, Eliezer; Shohat, Tamy; Streja, Elani; Norris, Keith C.; Kopple, Joel D.

2013-01-01

There are counterintuitive but consistent observations that African American maintenance dialysis patients have greater survival despite their less favorable socioeconomic status, high burden of cardiovascular risks including hypertension and diabetes, and excessively high chronic kidney disease prevalence. The fact that such individuals have a number of risk factors for lower survival and yet live longer when undergoing dialysis treatment is puzzling. Similar findings have been made among Israeli maintenance dialysis patients, in that those who are ethnically Arab have higher end-stage renal disease but exhibit greater survival than Jewish Israelis. The juxtaposition of these two situations may provide valuable insights into racial/ethnic-based mechanisms of survival in chronic diseases. Survival advantages of African American dialysis patients may be explained by differences in nutritional status, inflammatory profile, dietary intake habits, body composition, bone and mineral disorders, mental health and coping status, dialysis treatment differences, and genetic differences among other factors. Prospective studies are needed to examine similar models in other countries and to investigate the potential causes of these paradoxes in these societies. Better understanding the roots of racial/ethnic survival differences may help improve outcomes in both patients with chronic kidney disease and other individuals with chronic disease states. PMID:21175833

Endometrial Cancer: Socioeconomic Status and Racial/Ethnic Differences in Stage at Diagnosis, Treatment, and Survival

PubMed Central

Madison, Terri; Schottenfeld, David; James, Sherman A.; Schwartz, Ann G.; Gruber, Stephen B.

2004-01-01

Objective. We evaluated the association between socioeconomic status and racial/ ethnic differences in endometrial cancer stage at diagnosis, treatment, and survival. Methods. We conducted a population-based study among 3656 women. Results. Multivariate analyses showed that either race/ethnicity or income, but not both, was associated with advanced-stage disease. Age, stage at diagnosis, and income were independent predictors of hysterectomy. African American ethnicity, increased age, aggressive histology, poor tumor grade, and advanced-stage disease were associated with increased risk for death; higher income and hysterectomy were associated with decreased risk for death. Conclusions. Lower income was associated with advanced-stage disease, lower likelihood of receiving a hysterectomy, and lower rates of survival. Earlier diagnosis and removal of barriers to optimal treatment among lower-socioeconomic status women will diminish racial/ethnic differences in endometrial cancer survival. PMID:15569961

Effects of illegal harvest of eggs on the population decline of leatherback turtles in Las Baulas Marine National Park, Costa Rica.

PubMed

Tomillo, Pilar Santidrián; Saba, Vincent S; Piedra, Rotney; Paladino, Frank V; Spotila, James R

2008-10-01

Within 19 years the nesting population of leatherback turtles (Dermochelys coriacea) at Parque Nacional Marino Las Baulas declined from 1500 turtles nesting per year to about 100. We analyzed the effects of fishery bycatch and illegal harvesting (poaching) of eggs on this population. We modeled the population response to different levels of egg harvest (90, 75, 50, and 25%) and the effect of eradicating poaching at different times during the population decline. We compared effects of 90% poaching with those of 20% adult mortality because both of these processes were present in the population at Las Baulas. There was a stepwise decline in number of nesting turtles at all levels of egg harvest. Extirpation times for different levels of poaching ranged from 45 to 282 years. The nesting population declined more slowly and survived longer with 20% adult mortality (146 years) than it did with 90% poaching (45 years). Time that elapsed until poaching stopped determined the average population size at which the population stabilized, ranging from 90 to 420 nesting turtles. Our model predicted that saving clutches lost naturally would restore the population when adult mortality rates were low and would contribute more to population recovery when there were short remigration intervals between nesting seasons and a large proportion of natural loss of clutches. Because the model indicated that poaching was the most important cause of the leatherback decline at Las Baulas, protecting nests on the beach and protecting the beach from development are critical for survival of this population. Nevertheless, the model predicted that current high mortality rates of adults will prevent population recovery. Therefore, protection of the beach habitat and nests must be continued and fishery bycatch must be reduced to save this population.

Sex-specific movements in postfledging juvenile Ovenbirds (Seiurus aurocapilla)

Treesearch

Julianna M. A. Jenkins; Mikenzie Hart; Lori S. Eggert; John Faaborg

2017-01-01

Understanding sex-specific differences in behavior and survival is essential for informative population modeling and evolutionary biology in animal populations. Uneven sex ratios are common in many migrant passerine species; however, the underlying mechanisms remain unclear. We used molecular sex determination, nest monitoring, and radio telemetry of fledgling...

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection.

PubMed

Oddie, Melissa A Y; Dahle, Bjørn; Neumann, Peter

2017-01-01

Managed, feral and wild populations of European honey bee subspecies, Apis mellifera , are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor , that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera , is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor , we suggest learning more from nature, i.e., identifying the obviously efficient mechanisms favored by natural selection.

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection

PubMed Central

Dahle, Bjørn; Neumann, Peter

2017-01-01

Background Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Methods Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Results Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Discussion Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor, we suggest learning more from nature, i.e., identifying the obviously efficient mechanisms favored by natural selection. PMID:29085753

Survival trends among patients with advanced renal cell carcinoma in the United States.

PubMed

Shah, Binay Kumar; Ghimire, Krishna Bilas

2015-01-01

Since the approval of sorafenib in December 2005, several targeted therapeutic agents have been approved by the FDA for the treatment of advanced renal cell carcinoma (RCC). This study was conducted to find out whether the improvements in survival of advanced RCC patients with targeted agents have translated into a survival benefit in a population-based cohort. We analyzed the SEER 18 (Surveillance, Epidemiology and End RESULTS) registry database to calculate the relative survival rates for advanced RCC patients during 2001-2009, 2001-2005, 2006-2007 and 2008-2009. We also evaluated the survival rates by age (<65 and ≥65 years) and sex. The total number of advanced RCC patients during 2001-2009, 2001-2005, 2006-2007 and 2008-2009 were 7,047, 4,059, 1,548 and 1,440, respectively. During 2001-2009, the 1- and 3-year relative survival rates were 26.7±0.6 and 10.0±0.4%, respectively. There was no significant difference in 1-year relative survival rates for patients diagnosed during 2006-2007 and 2008-2009 compared to those diagnosed during 2001-2005. Similarly, the 3-year survival rates for patients diagnosed during 2006-2007 were similar to those diagnosed during 2001-2005. This population-based study showed that there was no significant improvement in relative survival rates among advanced RCC patients in the era of targeted agents. © 2014 S. Karger AG, Basel.

Assessing cancer drugs for reimbursement: methodology, relationship between effect size and medical need.

PubMed

de Sahb-Berkovitch, Rima; Woronoff-Lemsi, Marie-Christine; Molimard, Mathieu

2010-01-01

Reimbursement is assessed by the Transparency Commission from the Health Authority (HAS) using a medical benefit (SMR) score that gives access to reimbursement, an "improvement of medical service rendered" (ASMR) that determines the added therapeutic value, and the target population. Assessing cancer drugs for reimbursement raises the same issues as other therapeutic classes, with some key differences. Overall survival (OS) is considered by the Transparency Commission as the endpoint for assessing clinical benefit, and yet it is not an applicable primary endpoint in all types of cancer. Later lines of treatment, particularly during the development process, may make it difficult to interpret OS as the primary endpoint. Therefore, progression-free survival (PFS) for metastatic situations and disease-free survival (DFS) in adjuvant situations are wholly relevant endpoints for decisions on the reimbursement of a new cancer drug. Effect size is assessed using actuarial survival curves of the product versus the comparator, and it is difficult to summarise them into one single parameter. Results are generally interpreted based on median survival, which is fragmented because it only measures one point of the curve. The hazard ratio measures the effect of treatment throughout the duration of survival and is therefore more comprehensive in quantifying clinical benefit. Determining an effect size threshold for granting reimbursement is difficult given the diversity of cancer settings and the level of medical need, which influences assessment of the clinical relevance of the observed difference. Rapid progress in comparators (700 molecules in development) and the identification of predictive factors of efficacy (biomarkers, histology, etc.) during development may lead to different ASMR scores per population, or to the restriction of the target population to a subgroup of the marketing authorisation (MA) population in which the expected effect size is greater. To address these issues, the roundtable recommends the possibility of early scientific opinions by the office of the Transparency Commission in order to discuss comparators and the relevance of responder subgroups. It also recommends the possibility of granting a temporary ASMR, on condition of subsequent confirmation by production of data, when reimbursement appears justified in a subpopulation of the MA for which only subgroup analysis is available. © 2010 Société Française de Pharmacologie et de Thérapeutique.

Sociodemographic disparities in survival from colorectal cancer in South Australia: a population-wide data linkage study.

PubMed

Beckmann, Kerri R; Bennett, Alice; Young, Graeme P; Cole, Stephen R; Joshi, Rohit; Adams, Jacqui; Singhal, Nimit; Karapetis, Christos; Wattchow, David; Roder, David

2016-01-20

Inequalities in survival from colorectal cancer (CRC) across socioeconomic groups and by area of residence have been described in various health care settings. Few population-wide datasets which include clinical and treatment information are available in Australia to investigate disparities. This study examines socio-demographic differences in survival for CRC patients in South Australia (SA), using a population-wide database derived via linkage of administrative and surveillance datasets. The study population comprised all cases of CRC diagnosed in 2003-2008 among SA residents aged 50-79 yrs in the SA Central Cancer Registry. Measures of socioeconomic status (area level), geographical remoteness, clinical characteristics, comorbid conditions, treatments and outcomes were derived through record linkage of central cancer registry, hospital-based clinical registries, hospital separations, and radiotherapy services data sources. Socio-demographic disparities in CRC survival were examined using competing risk regression analysis. Four thousand six hundred and forty one eligible cases were followed for an average of 4.7 yrs, during which time 1525 died from CRC and 416 died from other causes. Results of competing risk regression indicated higher risk of CRC death with higher grade (HR high v low =2.25, 95% CI 1.32-3.84), later stage (HR C v A = 7.74, 95% CI 5.75-10.4), severe comorbidity (HR severe v none =1.21, 95% CI 1.02-1.44) and receiving radiotherapy (HR = 1.41, 95% CI 1.18-1.68). Patients from the most socioeconomically advantaged areas had significantly better outcomes than those from the least advantaged areas (HR =0.75, 95% 0.62-0.91). Patients residing in remote locations had significantly worse outcomes than metropolitan residents, though this was only evident for stages A-C (HR = 1.35, 95 % CI 1.01-1.80). These disparities were not explained by differences in stage at diagnosis between socioeconomic groups or area of residence. Nor were they explained by differences in patient factors, other tumour characteristics, comorbidity, or treatment modalities. Socio-economic and regional disparities in survival following CRC are evident in SA, despite having a universal health care system. Of particular concern is the poorer survival for patients from remote areas with potentially curable CRC. Reasons for these disparities require further exploration to identify factors that can be addressed to improve outcomes.

Abundance, survival, recruitment and effectiveness of sterilization of free-roaming dogs: A capture and recapture study in Brazil

PubMed Central

Struchiner, Claudio José; Werneck, Guilherme Loureiro; Teixeira Neto, Rafael Gonçalves; Tonelli, Gabriel Barbosa; de Carvalho Júnior, Clóvis Gomes; Ribeiro, Renata Aparecida Nascimento; da Silva, Eduardo Sérgio

2017-01-01

The existence of free-roaming dogs raises important issues in animal welfare and in public health. A proper understanding of these animals’ ecology is useful as a necessary input to plan strategies to control these populations. The present study addresses the population dynamics and the effectiveness of the sterilization of unrestricted dogs using capture and recapture procedures suitable for open animal populations. Every two months, over a period of 14 months, we captured, tagged, released and recaptured dogs in two regions in a city in the southeast region of Brazil. In one of these regions the animals were also sterilized. Both regions had similar social, environmental and demographic features. We estimated the presence of 148 females and 227 males during the period of study. The average dog:man ratio was 1 dog for each 42 and 51 human beings, in the areas without and with sterilization, respectively. The animal population size increased in both regions, due mainly to the abandonment of domestic dogs. Mortality rate decreased throughout the study period. Survival probabilities did not differ between genders, but males entered the population in higher numbers. There were no differences in abundance, survival and recruitment between the regions, indicating that sterilization did not affect the population dynamics. Our findings indicate that the observed animal dynamics were influenced by density-independent factors, and that sterilization might not be a viable and effective strategy in regions where availability of resources is low and animal abandonment rates are high. Furthermore, the high demographic turnover rates observed render the canine free-roaming population younger, thus more susceptible to diseases, especially to rabies and leishmaniasis. We conclude by stressing the importance of implementing educational programs to promote responsible animal ownership and effective strategies against abandonment practices. PMID:29091961

Abundance, survival, recruitment and effectiveness of sterilization of free-roaming dogs: A capture and recapture study in Brazil.

PubMed

Belo, Vinícius Silva; Struchiner, Claudio José; Werneck, Guilherme Loureiro; Teixeira Neto, Rafael Gonçalves; Tonelli, Gabriel Barbosa; de Carvalho Júnior, Clóvis Gomes; Ribeiro, Renata Aparecida Nascimento; da Silva, Eduardo Sérgio

2017-01-01

The existence of free-roaming dogs raises important issues in animal welfare and in public health. A proper understanding of these animals' ecology is useful as a necessary input to plan strategies to control these populations. The present study addresses the population dynamics and the effectiveness of the sterilization of unrestricted dogs using capture and recapture procedures suitable for open animal populations. Every two months, over a period of 14 months, we captured, tagged, released and recaptured dogs in two regions in a city in the southeast region of Brazil. In one of these regions the animals were also sterilized. Both regions had similar social, environmental and demographic features. We estimated the presence of 148 females and 227 males during the period of study. The average dog:man ratio was 1 dog for each 42 and 51 human beings, in the areas without and with sterilization, respectively. The animal population size increased in both regions, due mainly to the abandonment of domestic dogs. Mortality rate decreased throughout the study period. Survival probabilities did not differ between genders, but males entered the population in higher numbers. There were no differences in abundance, survival and recruitment between the regions, indicating that sterilization did not affect the population dynamics. Our findings indicate that the observed animal dynamics were influenced by density-independent factors, and that sterilization might not be a viable and effective strategy in regions where availability of resources is low and animal abandonment rates are high. Furthermore, the high demographic turnover rates observed render the canine free-roaming population younger, thus more susceptible to diseases, especially to rabies and leishmaniasis. We conclude by stressing the importance of implementing educational programs to promote responsible animal ownership and effective strategies against abandonment practices.

Isolation Driven Divergence in Osmoregulation in Galaxias maculatus (Jenyns, 1848) (Actinopterygii: Osmeriformes).

PubMed

Ruiz-Jarabo, Ignacio; González-Wevar, Claudio A; Oyarzún, Ricardo; Fuentes, Juan; Poulin, Elie; Bertrán, Carlos; Vargas-Chacoff, Luis

2016-01-01

Marine species have colonized extreme environments during evolution such as freshwater habitats. The amphidromous teleost fish, Galaxias maculatus is found mainly migrating between estuaries and rivers, but some landlocked populations have been described in lakes formed during the last deglaciation process in the Andes. In the present study we use mtDNA sequences to reconstruct the historical scenario of colonization of such a lake and evaluated the osmoregulatory shift associated to changes in habitat and life cycle between amphidromous and landlocked populations. Standard diversity indices including the average number of nucleotide differences (Π) and the haplotype diversity index (H) indicated that both populations were, as expected, genetically distinctive, being the landlocked population less diverse than the diadromous one. Similarly, pairwise GST and NST comparison detected statistically significant differences between both populations, while genealogy of haplotypes evidenced a recent founder effect from the diadromous stock, followed by an expansion process in the lake. To test for physiological differences, individuals of both populations were challenged with a range of salinities from 0 to 30 ppt for 8 days following a period of progressive acclimation. The results showed that the landlocked population had a surprisingly wider tolerance to salinity, as landlocked fish survival was 100% from 0 to 20 ppt, whereas diadromous fish survival was 100% only from 10 to 15 ppt. The activity of ATPase enzymes, including Na+/K+-ATPase (NKA), and H+-ATPase (HA) was measured in gills and intestine. Activity differences were detected between the populations at the lowest salinities, including differences in ATPases other than NKA and HA. Population differences in mortality are not reflected in enzyme activity differences, suggesting divergence in other processes. These results clearly demonstrate the striking adaptive changes of G. maculatus osmoregulatory system, especially at hyposmotic environments, associated to a drastic shift in habitat and life cycle at a scale of a few thousand years.

Isolation Driven Divergence in Osmoregulation in Galaxias maculatus (Jenyns, 1848) (Actinopterygii: Osmeriformes)

PubMed Central

Ruiz-Jarabo, Ignacio; Oyarzún, Ricardo; Fuentes, Juan; Poulin, Elie; Bertrán, Carlos; Vargas-Chacoff, Luis

2016-01-01

Background Marine species have colonized extreme environments during evolution such as freshwater habitats. The amphidromous teleost fish, Galaxias maculatus is found mainly migrating between estuaries and rivers, but some landlocked populations have been described in lakes formed during the last deglaciation process in the Andes. In the present study we use mtDNA sequences to reconstruct the historical scenario of colonization of such a lake and evaluated the osmoregulatory shift associated to changes in habitat and life cycle between amphidromous and landlocked populations. Results Standard diversity indices including the average number of nucleotide differences (Π) and the haplotype diversity index (H) indicated that both populations were, as expected, genetically distinctive, being the landlocked population less diverse than the diadromous one. Similarly, pairwise GST and NST comparison detected statistically significant differences between both populations, while genealogy of haplotypes evidenced a recent founder effect from the diadromous stock, followed by an expansion process in the lake. To test for physiological differences, individuals of both populations were challenged with a range of salinities from 0 to 30 ppt for 8 days following a period of progressive acclimation. The results showed that the landlocked population had a surprisingly wider tolerance to salinity, as landlocked fish survival was 100% from 0 to 20 ppt, whereas diadromous fish survival was 100% only from 10 to 15 ppt. The activity of ATPase enzymes, including Na+/K+-ATPase (NKA), and H+-ATPase (HA) was measured in gills and intestine. Activity differences were detected between the populations at the lowest salinities, including differences in ATPases other than NKA and HA. Population differences in mortality are not reflected in enzyme activity differences, suggesting divergence in other processes. Conclusions These results clearly demonstrate the striking adaptive changes of G. maculatus osmoregulatory system, especially at hyposmotic environments, associated to a drastic shift in habitat and life cycle at a scale of a few thousand years. PMID:27168069

Survival, growth, and movement of subadult humpback chub, Gila cypha, in the Little Colorado River, Arizona

USGS Publications Warehouse

Dzul, Maria C.; Yackulic, Charles B.; Stone, Dennis M.; Van Haverbeke, David R.

2016-01-01

Ecologists estimate vital rates, such as growth and survival, to better understand population dynamics and identify sensitive life history parameters for species or populations of concern. Here, we assess spatiotemporal variation in growth, movement, density, and survival of subadult humpback chub living in the Little Colorado River, Grand Canyon, AZ from 2001–2002 and 2009–2013. We divided the Little Colorado River into three reaches and used a multistate mark-recapture model to determine rates of movement and differences in survival and density between sites for different cohorts. Additionally, site-specific and year-specific effects on growth were evaluated using a linear model. Results indicate that summer growth was higher for upstream sites compared with downstream sites. In contrast, there was not a consistent spatial pattern across years in winter growth; however, river-wide winter growth was negatively related to the duration of floods from 1 October to 15 May. Apparent survival was estimated to be lower at the most downstream site compared with the upstream sites; however, this could be because in part of increased emigration into the Colorado River at downstream sites. Furthermore, the 2010 cohort (i.e. fish that are age 1 in 2010) exhibited high apparent survival relative to other years. Movement between reaches varied with year, and some years exhibited preferential upstream displacement. Improving understanding of spatiotemporal effects on age 1 humpback chub survival can help inform current management efforts to translocate humpback chub into new locations and give us a better understanding of the factors that may limit this tributary's carrying capacity for humpback chub.

Survival of northern pintails banded during winter in North America, 1950-88

USGS Publications Warehouse

Hestbeck, J.B.

1993-01-01

From 1950 through 1988, the continental breeding population of northern pintails (Anas acuta) varied from 2.0 million to 9.9 million. Because pintails have high fidelity to certain wintering grounds along coasts and large bodies of water, management on these wintering areas may increase population size if changes in winter survival rate are related to changes in population size. I used band-recovery data to estimate survival rates for winter-banded pintails and to test for sex-specific, temporal, and geographic variation in survival rates. Survival rate estimates varied between 0.632 and 0.806 for males, and 0.421 and 0.769 for females. Males had higher (P lt 0.0001) average annual survival rates than females. Limited geographic variation occurred in estimates of average annual survival rates for males, and no variation occurred for females. Males had lower average annual survival rates in the Imperial Valley than in central California (P = 0.007) or in the Gulf Coast (P = 0.092). Little annual variation was found within time periods. However, longer-term variation was found in survival rate estimates for males and females. Males had higher (P = 0.054) average annual survival rates in the Pacific Flyway during 1959-61, a period of drought, breeding-population decline, and restrictive hunting regulations, than during 1950-58, a period with a higher breeding population and liberal regulations. The increase in wintering population size in the Pacific Flyway during the 1970's was associated with a higher average annual survival rate for females in the Pacific Flyway than during the 1950's. Results from the Pacific Flyway suggested that an interaction may exist between population size and the effect of harvest regulations on survival of males. Changes in harvest regulations appeared to have a greater effect at lower population levels.

Spatiotemporal variation in survival rates: implications for population dynamics of yellow-bellied marmots.

PubMed

Ozgul, Arpat; Armitage, Kenneth B; Blumstein, Daniel T; Oli, Madan K

2006-04-01

Spatiotemporal variation in age-specific survival rates can profoundly influence population dynamics, but few studies of vertebrates have thoroughly investigated both spatial and temporal variability in age-specific survival rates. We used 28 years (1976-2003) of capture-mark-recapture (CMR) data from 17 locations to parameterize an age-structured Cormack-Jolly-Seber model, and investigated spatial and temporal variation in age-specific annual survival rates of yellow-bellied marmots (Marmota flaviventris). Survival rates varied both spatially and temporally, with survival of younger animals exhibiting the highest degree of variation. Juvenile survival rates varied from 0.52 +/- 0.05 to 0.78 +/- 0.10 among sites and from 0.15 +/- 0.14 to 0.89 +/- 0.06 over time. Adult survival rates varied from 0.62 +/- 0.09 to 0.80 +/- 0.03 among sites, but did not vary significantly over time. We used reverse-time CMR models to estimate the realized population growth rate (lamda), and to investigate the influence of the observed variation in age-specific survival rates on lamda. The realized growth rate of the population closely covaried with, and was significantly influenced by, spatiotemporal variation in juvenile survival rate. High variability in juvenile survival rates over space and time clearly influenced the dynamics of our study population and is also likely to be an important determinant of the spatiotemporal variation in the population dynamics of other mammals with similar life history characteristics.

Predictive and Prognostic Implications of Variant Philadelphia Translocations in CML: Experience From a Tertiary Oncology Center in Southern India.

PubMed

Kanakasetty, Govind Babu; Kuntejowdahalli, Lakshmaiah; Thanky, Aditi Harsh; Dasappa, Lokanatha; Jacob, Linu Abraham; Mallekavu, Suresh Babu; Kumari, Prasanna

2017-01-01

Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by Philadelphia (Ph) chromosome with classical t(9;22)(q34;q11) seen in up to 90% of cases. However 5% to 10% of patients who present with variant Ph translocations (vPh) have been an area of research for their significance in predicting response to various therapies including tyrosine kinase inhibitors as well as prognosticating survival outcomes for many years involving varied patient populations, with conflicting results. We retrospectively analyzed our data from January 2002 to December 2014. Patients with vPh in chronic phase of CML (CML-CP) were analyzed with respect to their demographic parameters, response to imatinib therapy, and survival and their data were compared with data of patients with classical Ph translocation (cPh). Of 615 patients diagnosed with CML-CP, 72 patients (11.7%) showed vPh. Most common chromosomes involved in these translocations were 14 (13.9%), 11 (12.5%), 19 (9.7%), and 7 (8.3%). Rates of complete hematological response, complete cytogenetic response, and major molecular response were not statistically different between the groups. At 5 years, event-free survival, failure-free survival, progression-free survival, and overall survival were 60% versus 67.9%, 62.7% versus 69.7%, 84.7% versus 92.1%, and 87.5% versus 92.4%, respectively, in vPh and cPh. The differences in survival were statistically not significant. To our knowledge, this is the largest series of variant translocations in CML-CP, pertaining to the Indian population. Our data suggest that the presence of vPh in CML has no significant effect in predicting response to imatinib as well as in prognosticating survival. Copyright © 2016 Elsevier Inc. All rights reserved.

Plumage polymorphism and fitness in Swainson's hawks.

PubMed

Briggs, C W; Collopy, M W; Woodbridge, B

2011-10-01

We examine the maintenance of a plumage polymorphism, variation in plumages among the same age and sex class within a population, in a population of Swainson's Hawks. We take advantage of 32 years of data to examine two prevalent hypotheses used to explain the persistence of morphs: apostatic selection and heterozygous advantage. We investigate differences in fitness among three morph classes of a melanistic trait in Swainson's Hawks: light (7% of the local breeding population), intermediate (57%) and dark (36%). Specifically, we examined morph differences in adult apparent survival, breeding success, annual number of fledglings produced, probability of offspring recruitment into the breeding population and lifetime reproductive success (LRS). If apostatic selection were a factor in maintaining morphs, we would expect that individuals with the least frequent morph would perform best in one or more of these fitness categories. Alternatively, if heterozygous advantage played a role in the maintenance of this polymorphism, we would expect heterozygotes (i.e. intermediate morphs) to have one or more increased rates in these categories. We found no difference in adult apparent survival between morph classes. Similarly, there were no differences in breeding success, nest productivity, LRS or probability of recruitment of offspring between parental morph. We conclude that neither apostatic selection nor heterozygous advantage appear to play a role in maintaining morphs in this population. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

Racial differences in colorectal cancer survival at a safety net hospital.

PubMed

Tapan, Umit; Lee, Shin Yin; Weinberg, Janice; Kolachalama, Vijaya B; Francis, Jean; Charlot, Marjory; Hartshorn, Kevan; Chitalia, Vipul

2017-08-01

While racial disparity in colorectal cancer survival have previously been studied, whether this disparity exists in patients with metastatic colorectal cancer receiving care at safety net hospitals (and therefore of similar socioeconomic status) is poorly understood. We examined racial differences in survival in a cohort of patients with stage IV colorectal cancer treated at the largest safety net hospital in the New England region, which serves a population with a majority (65%) of non-Caucasian patients. Data was extracted from the hospital's electronic medical record. Survival differences among different racial and ethnic groups were examined graphically using Kaplan-Meier analysis. A univariate cox proportional hazards model and a multivariable adjusted model were generated. Black patients had significantly lower overall survival compared to White patients, with median overall survival of 1.9 years and 2.5 years respectively. In a multivariate analysis, Black race posed a significant hazard (HR 1.70, CI 1.01-2.90, p=0.0467) for death. Though response to therapy emerged as a strong predictor of survival (HR=0.4, CI=0.2-0.7, p=0.0021), it was comparable between Blacks and Whites. Despite presumed equal access to healthcare and socioeconomic status within a safety-net hospital system, our results reinforce findings from previous studies showing lower colorectal cancer survival in Black patients, and also point to the importance of investigating other factors such as genetic and pathologic differences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Females lead population collapse of the endangered Hawaii creeper.

PubMed

Freed, Leonard A; Cann, Rebecca L

2013-01-01

Population collapses result from drastic environmental changes, but the sexes may differ in vulnerability. Collapse of the endangered Hawaii creeper (Oreomystis mana) at Hakalau Forest National Wildlife Refuge resulted from food limitation associated with increased numbers of an introduced bird (Japanese white-eye, Zosterops japonicus), which competes with the creeper for food. Both creeper sexes had stunted bill growth and the greatest change in molt of native species in the community. With a surge in numbers of white-eyes, a recent cohort of adult females had very low survival after breeding, while adult males from the same cohort, and older females and males, continued to have high survival. Lower female survival resulted in a significantly more male-biased adult sex ratio. Recent low female survival was based on a great cost of reproduction, indicated by molt-breeding overlap that was previously avoided, and lower fat during the lengthy fledgling period. The difference in female survival between cohorts was associated with stunted bills from being reared in and then breeding in an increasingly poor food environment. Trend analysis of survey data indicate that the bird is declining throughout the refuge, with males being 72-80% of adults left six years after the white-eye increased. Competition over time was consistent with that previously documented over space on the Island of Hawaii. Adaptive management to recover the bird in this protected area needs to focus on improving both adult female survival and the adult sex ratio.

Females Lead Population Collapse of the Endangered Hawaii Creeper

PubMed Central

Freed, Leonard A.; Cann, Rebecca L.

2013-01-01

Population collapses result from drastic environmental changes, but the sexes may differ in vulnerability. Collapse of the endangered Hawaii creeper (Oreomystis mana) at Hakalau Forest National Wildlife Refuge resulted from food limitation associated with increased numbers of an introduced bird (Japanese white-eye, Zosterops japonicus), which competes with the creeper for food. Both creeper sexes had stunted bill growth and the greatest change in molt of native species in the community. With a surge in numbers of white-eyes, a recent cohort of adult females had very low survival after breeding, while adult males from the same cohort, and older females and males, continued to have high survival. Lower female survival resulted in a significantly more male-biased adult sex ratio. Recent low female survival was based on a great cost of reproduction, indicated by molt-breeding overlap that was previously avoided, and lower fat during the lengthy fledgling period. The difference in female survival between cohorts was associated with stunted bills from being reared in and then breeding in an increasingly poor food environment. Trend analysis of survey data indicate that the bird is declining throughout the refuge, with males being 72–80% of adults left six years after the white-eye increased. Competition over time was consistent with that previously documented over space on the Island of Hawaii. Adaptive management to recover the bird in this protected area needs to focus on improving both adult female survival and the adult sex ratio. PMID:23861831

Cure fraction model with random effects for regional variation in cancer survival.

PubMed

Seppä, Karri; Hakulinen, Timo; Kim, Hyon-Jung; Läärä, Esa

2010-11-30

Assessing regional differences in the survival of cancer patients is important but difficult when separate regions are small or sparsely populated. In this paper, we apply a mixture cure fraction model with random effects to cause-specific survival data of female breast cancer patients collected by the population-based Finnish Cancer Registry. Two sets of random effects were used to capture the regional variation in the cure fraction and in the survival of the non-cured patients, respectively. This hierarchical model was implemented in a Bayesian framework using a Metropolis-within-Gibbs algorithm. To avoid poor mixing of the Markov chain, when the variance of either set of random effects was close to zero, posterior simulations were based on a parameter-expanded model with tailor-made proposal distributions in Metropolis steps. The random effects allowed the fitting of the cure fraction model to the sparse regional data and the estimation of the regional variation in 10-year cause-specific breast cancer survival with a parsimonious number of parameters. Before 1986, the capital of Finland clearly stood out from the rest, but since then all the 21 hospital districts have achieved approximately the same level of survival. Copyright © 2010 John Wiley & Sons, Ltd.

Effect of canopy position on germination and seedling survival of epiphytic bromeliads in a Mexican humid montane forest.

PubMed

Winkler, Manuela; Hülber, Karl; Hietz, Peter

2005-05-01

Seeds of epiphytes must land on branches with suitable substrates and microclimates to germinate and for the resulting seedlings to survive. It is important to understand the fate of seeds and seedlings in order to model populations, but this is often neglected when only established plants are included in analyses. The seeds of five bromeliad species were exposed to different canopy positions in a Mexican montane forest, and germination and early seedling survival were recorded. Additionally, the survival of naturally dispersed seedlings was monitored in a census over 2.5 years. Survival analysis, a procedure rarely used in plant ecology, was used to study the influence of branch characteristics and light on germination and seedling survival in natural and experimental populations. Experimental germination percentages ranged from 7.2 % in Tillandsia deppeana to 33.7 % in T. juncea, but the seeds of T. multicaulis largely failed to germinate. Twenty months after exposure between 3.5 and 9.4 % of the seedlings were still alive. There was no evidence that canopy position affected the probability of germination, but time to germination was shorter in less exposed canopy positions indicating that higher humidity accelerates germination. More experimental seedlings survived when canopy openness was high, whereas survival in census-seedlings was influenced by moss cover. While mortality decreased steadily with age in juveniles of the atmospheric Tillandsia, in the more mesomorphic Catopsis sessiliflora mortality increased dramatically in the dry season. Seedling mortality, rather than the failure to germinate, accounts for the differential distribution of epiphytes within the canopy studied. With few safe sites to germinate and high seedling mortality, changes of local climate may affect epiphyte populations primarily through their seedling stage.

The effect of the AED and AED programs on survival of individuals, groups and populations.

PubMed

Stokes, Nathan Allen; Scapigliati, Andrea; Trammell, Antoine R; Parish, David C

2012-10-01

The automated external defibrillator (AED) is a tool that contributes to survival with mixed outcomes. This review assesses the effectiveness of the AED, consistencies and variations among studies, and how varying outcomes can be resolved. A worksheet for the International Liaison Committee on Resuscitation (ILCOR) 2010 science review focused on hospital survival in AED programs was the foundation of the articles reviewed. Articles identified in the search covering a broader range of topics were added. All articles were read by at least two authors; consensus discussions resolved differences. AED use developed sequentially. Use of AEDs by emergency medical technicians (EMTs) compared to manual defibrillators showed equal or superior survival. AED use was extended to trained responders likely to be near victims, such as fire/rescue, police, airline attendants, and casino security guards, with improvement in all venues but not all programs. Broad public access initiatives demonstrated increased survival despite low rates of AED use. Home AED programs have not improved survival; in-hospital trials have had mixed results. Successful programs have placed devices in high-risk sites, maintained the AEDs, recruited a team with a duty to respond, and conducted ongoing assessment of the program. The AED can affect survival among patients with sudden ventricular fibrillation (VF). Components of AED programs that affect outcome include the operator, location, the emergency response system, ongoing maintenance and evaluation. Comparing outcomes is complicated by variations in definitions of populations and variables. The effect of AEDs on individuals can be dramatic, but the effect on populations is limited.

Variation in performance on cry1Ab-transformed and nontransgenic rice varieties among populations of Scirpophaga incertulas (Lepidoptera: Pyralidae) from Luzon Island, Philippines.

PubMed

Bentur, J S; Cohen, M B; Gould, F

2000-12-01

We quantified variation in performance under greenhouse conditions among seven populations of Scirpophaga incertulas (Walker) from Luzon Island, Philippines, on three rice varieties: 'IR58' transformed with the cry1Ab gene from Bacillus thuringiensis Berliner, and nontransgenic IR58 and IR62. On IR62, S. incertutas performance did not differ among provinces for any of the 10 parameters measured, but there was a significant effect of town within province for one parameter, 20-d-old larval weight. Larval survival after 48 h on cy1Ab-transformed IR58 did not differ significantly among provinces, but did differ significantly among towns within a province. There was no geographic variation in larval survival after 48 h on control plants of IR58. Surviving insects from the cry1Ab-transformed IR58 were transferred to IR62 to complete development. There was no geographic variation in the percentage of insects completing development to adult emergence and the time required by the transferred female insects to complete development. However, there was variation among provinces in male developmental time. The absence of geographic variation on nontransgenic IR58 and the very limited variation on IR62 indicated that there was little variation in general vigor among the S. incertulas populations and thus that the variation in performance oil cry1Ab-transformed IR58 was probably attributable to differences in susceptibility to Cry1Ab.

Constructing stage-structured matrix population models from life tables: comparison of methods

PubMed Central

Diaz-Lopez, Jasmin

2017-01-01

A matrix population model is a convenient tool for summarizing per capita survival and reproduction rates (collectively vital rates) of a population and can be used for calculating an asymptotic finite population growth rate (λ) and generation time. These two pieces of information can be used for determining the status of a threatened species. The use of stage-structured population models has increased in recent years, and the vital rates in such models are often estimated using a life table analysis. However, potential bias introduced when converting age-structured vital rates estimated from a life table into parameters for a stage-structured population model has not been assessed comprehensively. The objective of this study was to investigate the performance of methods for such conversions using simulated life histories of organisms. The underlying models incorporate various types of life history and true population growth rates of varying levels. The performance was measured by comparing differences in λ and the generation time calculated using the Euler-Lotka equation, age-structured population matrices, and several stage-structured population matrices that were obtained by applying different conversion methods. The results show that the discretization of age introduces only small bias in λ or generation time. Similarly, assuming a fixed age of maturation at the mean age of maturation does not introduce much bias. However, aggregating age-specific survival rates into a stage-specific survival rate and estimating a stage-transition rate can introduce substantial bias depending on the organism’s life history type and the true values of λ. In order to aggregate survival rates, the use of the weighted arithmetic mean was the most robust method for estimating λ. Here, the weights are given by survivorship curve after discounting with λ. To estimate a stage-transition rate, matching the proportion of individuals transitioning, with λ used for discounting the rate, was the best approach. However, stage-structured models performed poorly in estimating generation time, regardless of the methods used for constructing the models. Based on the results, we recommend using an age-structured matrix population model or the Euler-Lotka equation for calculating λ and generation time when life table data are available. Then, these age-structured vital rates can be converted into a stage-structured model for further analyses. PMID:29085763

Constructing stage-structured matrix population models from life tables: comparison of methods.

PubMed

Fujiwara, Masami; Diaz-Lopez, Jasmin

2017-01-01

A matrix population model is a convenient tool for summarizing per capita survival and reproduction rates (collectively vital rates) of a population and can be used for calculating an asymptotic finite population growth rate ( λ ) and generation time. These two pieces of information can be used for determining the status of a threatened species. The use of stage-structured population models has increased in recent years, and the vital rates in such models are often estimated using a life table analysis. However, potential bias introduced when converting age-structured vital rates estimated from a life table into parameters for a stage-structured population model has not been assessed comprehensively. The objective of this study was to investigate the performance of methods for such conversions using simulated life histories of organisms. The underlying models incorporate various types of life history and true population growth rates of varying levels. The performance was measured by comparing differences in λ and the generation time calculated using the Euler-Lotka equation, age-structured population matrices, and several stage-structured population matrices that were obtained by applying different conversion methods. The results show that the discretization of age introduces only small bias in λ or generation time. Similarly, assuming a fixed age of maturation at the mean age of maturation does not introduce much bias. However, aggregating age-specific survival rates into a stage-specific survival rate and estimating a stage-transition rate can introduce substantial bias depending on the organism's life history type and the true values of λ . In order to aggregate survival rates, the use of the weighted arithmetic mean was the most robust method for estimating λ . Here, the weights are given by survivorship curve after discounting with λ . To estimate a stage-transition rate, matching the proportion of individuals transitioning, with λ used for discounting the rate, was the best approach. However, stage-structured models performed poorly in estimating generation time, regardless of the methods used for constructing the models. Based on the results, we recommend using an age-structured matrix population model or the Euler-Lotka equation for calculating λ and generation time when life table data are available. Then, these age-structured vital rates can be converted into a stage-structured model for further analyses.

Fluctuating survival selection explains variation in avian group size

PubMed Central

Brown, Charles R.; Brown, Mary Bomberger; Roche, Erin A.; O’Brien, Valerie A.; Page, Catherine E.

2016-01-01

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark–recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population. PMID:27091998

Fluctuating survival selection explains variation in avian group size.

PubMed

Brown, Charles R; Brown, Mary Bomberger; Roche, Erin A; O'Brien, Valerie A; Page, Catherine E

2016-05-03

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark-recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

Fluctuating survival selection explains variation in avian group size

USGS Publications Warehouse

Brown, Charles B.; Brown, Mary Bomberger; Roche, Erin A.; O'brien, Valerie A; Page, Catherine E.

2016-01-01

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark–recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

Intraspecific variation in the growth and survival of juvenile fish exposed to Eucalyptus leachate

PubMed Central

Morrongiello, John R; Bond, Nicholas R; Crook, David A; Wong, Bob B M

2013-01-01

Whilst changes in freshwater assemblages along gradients of environmental stress have been relatively well studied, we know far less about intraspecific variation to these same stressors. A stressor common in fresh waters worldwide is leachates from terrestrial plants. Leachates alter the physiochemical environment of fresh waters by lowering pH and dissolved oxygen and also releasing toxic compounds such as polyphenols and tannins, all of which can be detrimental to aquatic organisms. We investigated how chronic exposure to Eucalyptus leaf leachate affected the growth and survival of juvenile southern pygmy perch (Nannoperca australis) collected from three populations with different litter inputs, hydrology and observed leachate concentrations. Chronic exposure to elevated leachate levels negatively impacted growth and survival, but the magnitude of these lethal and sublethal responses was conditional on body size and source population. Bigger fish had increased survival at high leachate levels but overall slower growth rates. Body size also varied among populations and fish from the population exposed to the lowest natural leachate concentrations had the highest average stress tolerance. Significant intraspecific variation in both growth and survival caused by Eucalyptus leachate exposure indicates that the magnitude (but not direction) of these stress responses varies across the landscape. This raises the potential for leachate-induced selection to operate at an among-population scale. The importance of body size demonstrates that the timing of leachate exposure during ontogeny is central in determining the magnitude of biological response, with early life stages being most vulnerable. Overall, we demonstrate that Eucalyptus leachates are prevalent and potent selective agents that can trigger important sublethal impacts, beyond those associated with more familiar fish kills, and reiterate that dissolved organic carbon is more than just an energy source in aquatic environments. PMID:24198944

Coding completeness and quality of relative survival-related variables in the National Program of Cancer Registries Cancer Surveillance System, 1995-2008.

PubMed

Wilson, Reda J; O'Neil, M E; Ntekop, E; Zhang, Kevin; Ren, Y

2014-01-01

Calculating accurate estimates of cancer survival is important for various analyses of cancer patient care and prognosis. Current US survival rates are estimated based on data from the National Cancer Institute's (NCI's) Surveillance, Epidemiology, and End RESULTS (SEER) program, covering approximately 28 percent of the US population. The National Program of Cancer Registries (NPCR) covers about 96 percent of the US population. Using a population-based database with greater US population coverage to calculate survival rates at the national, state, and regional levels can further enhance the effective monitoring of cancer patient care and prognosis in the United States. The first step is to establish the coding completeness and coding quality of the NPCR data needed for calculating survival rates and conducting related validation analyses. Using data from the NPCR-Cancer Surveillance System (CSS) from 1995 through 2008, we assessed coding completeness and quality on 26 data elements that are needed to calculate cancer relative survival estimates and conduct related analyses. Data elements evaluated consisted of demographic, follow-up, prognostic, and cancer identification variables. Analyses were performed showing trends of these variables by diagnostic year, state of residence at diagnosis, and cancer site. Mean overall percent coding completeness by each NPCR central cancer registry averaged across all data elements and diagnosis years ranged from 92.3 percent to 100 percent. RESULTS showing the mean percent coding completeness for the relative survival-related variables in NPCR data are presented. All data elements but 1 have a mean coding completeness greater than 90 percent as was the mean completeness by data item group type. Statistically significant differences in coding completeness were found in the ICD revision number, cause of death, vital status, and date of last contact variables when comparing diagnosis years. The majority of data items had a coding quality greater than 90 percent, with exceptions found in cause of death, follow-up source, and the SEER Summary Stage 1977, and SEER Summary Stage 2000. Percent coding completeness and quality are very high for variables in the NPCR-CSS that are covariates to calculating relative survival. NPCR provides the opportunity to calculate relative survival that may be more generalizable to the US population.

Long-term survival and conditional survival of cancer patients in Japan using population-based cancer registry data

PubMed Central

Ito, Yuri; Miyashiro, Isao; Ito, Hidemi; Hosono, Satoyo; Chihara, Dai; Nakata-Yamada, Kayo; Nakayama, Masashi; Matsuzaka, Masashi; Hattori, Masakazu; Sugiyama, Hiromi; Oze, Isao; Tanaka, Rina; Nomura, Etsuko; Nishino, Yoshikazu; Matsuda, Tomohiro; Ioka, Akiko; Tsukuma, Hideaki; Nakayama, Tomio

2014-01-01

Although we usually report 5-year cancer survival using population-based cancer registry data, nowadays many cancer patients survive longer and need to be followed-up for more than 5 years. Long-term cancer survival figures are scarce in Japan. Here we report 10-year cancer survival and conditional survival using an established statistical approach. We received data on 1 387 489 cancer cases from six prefectural population-based cancer registries in Japan, diagnosed between 1993 and 2009 and followed-up for at least 5 years. We estimated the 10-year relative survival of patients who were followed-up between 2002 and 2006 using period analysis. Using this 10-year survival, we also calculated the conditional 5-year survival for cancer survivors who lived for some years after diagnosis. We reported 10-year survival and conditional survival of 23 types of cancer for 15–99-year-old patients and four types of cancer for children (0–14 years old) and adolescent and young adults (15–29 years old) patients by sex. Variation in 10-year cancer survival by site was wide, from 5% for pancreatic cancer to 95% for female thyroid cancer. Approximately 70–80% of children and adolescent and young adult cancer patients survived for more than 10 years. Conditional 5-year survival for most cancer sites increased according to years, whereas those for liver cancer and multiple myeloma did not increase. We reported 10-year cancer survival and conditional survival using population-based cancer registries in Japan. It is important for patients and clinicians to report these relevant figures using population-based data. PMID:25183551

Phenotypically heterogeneous populations in spatially heterogeneous environments

NASA Astrophysics Data System (ADS)

Patra, Pintu; Klumpp, Stefan

2014-03-01

The spatial expansion of a population in a nonuniform environment may benefit from phenotypic heterogeneity with interconverting subpopulations using different survival strategies. We analyze the crossing of an antibiotic-containing environment by a bacterial population consisting of rapidly growing normal cells and slow-growing, but antibiotic-tolerant persister cells. The dynamics of crossing is characterized by mean first arrival times and is found to be surprisingly complex. It displays three distinct regimes with different scaling behavior that can be understood based on an analytical approximation. Our results suggest that a phenotypically heterogeneous population has a fitness advantage in nonuniform environments and can spread more rapidly than a homogeneous population.

Effect of storage temperatures and stresses on the survival of Salmonella spp. in halva.

PubMed

Osaili, T M; Al-Nabulsi, A A; Nazzal, D S; Shaker, R R

2017-11-01

The presence of Salmonella spp. in halva has been associated with foodborne illnesses and product recalls from the markets. This study investigated the effect of environmental stresses on the survival of Salmonella spp. in halva during storage for 12 months at 10 and 25°C (log (N 0 /N) g -1 ). Halva samples were inoculated with a cocktail of four strains of unstressed, desiccation stressed or heat stressed Salmonella (10 6 -10 7  CFU per gram). In general, survival of Salmonella spp. in halva decreased significantly (P ˂ 0·05) as storage time and temperature increased. At the end of halva shelf life at 10°C, the initial populations of unstressed, desiccation stressed or heat stressed Salmonella spp. decreased by 2·7, 2·6 or 2·8 log CFU per gram (reduction rate c. 0·2 log CFU per month), respectively. While at 25°C, the populations decreased 5·2, 6·7 or 6·3 log CFU per gram, respectively (reduction rate c. 0·4-0·5 log CFU per month). The populations of stressed Salmonella spp. in halva samples were not significantly different (P ≥ 0·05) from populations of unstressed cells during storage at 10 and 25°C, except during the last 3 months of storage at 25°C when populations of unstressed cells were higher (P < 0·05). Exposing Salmonella spp. to desiccation or heat stress prior product contamination may play a role in Salmonella spp. survival in halva during storage. Contamination of halva (tahini halva) with Salmonella from raw materials or during production was documented. Halva and tahini have been involved in salmonellosis outbreaks in different countries. The study demonstrated enhanced survivability of stressed and unstressed Salmonella spp. in halva over a 12-month storage period at 10 and 25°C with lower log reductions than expected. Exposing Salmonella spp. to desiccation or heat stress prior product contamination may play a role in microbial survival in halva during storage. These findings serve as a model to halva producers to implement control measures to prevent Salmonella spp. contamination in halva. © 2017 The Society for Applied Microbiology.

Parent Genotype and Environmental Factors Influence Introduction Success of the Critically Endangered Savannas Mint (Dicerandra immaculata var. savannarum)

PubMed Central

Peterson, Cheryl L.; Kaufmann, Gregory S.; Vandello, Christopher; Richardson, Matthew L.

2013-01-01

Species previously unknown to science are continually discovered and some of these species already face extinction at the time of their discovery. Conserving new and rare species in these cases becomes a trial-and-error process and conservationists will attempt to manage them by using knowledge of closely related species, or those that fill the same ecological niche, and then adapting the management program as needed. Savannas Mint (Dicerandra immaculata Lakela var. savannarum Huck) is a perennial plant that was discovered in Florida scrub habitat at two locations in 1995, but is nearly extinct at these locations. We tested whether shade, leaf litter, propagation method, parent genotype, parent collection site, planting date, and absorbent granules influenced survival, reproduction, and recruitment of Savannas Mint in a population of 1,614 plants that we introduced between June 2006 and July 2009 into a state protected site. Survival and reproduction of introduced plants, and recruitment of new plants, was higher in microhabitats in full sun and no leaf litter and lower in partially shaded habitats. The two sites from which parent plants were collected differentially influenced survival and reproduction of introduced plants. These differences in survival and reproduction are likely due to underlying genetic differences. Differential survival of progeny from different parent genotypes further supports the idea that underlying genetics is an important consideration when restoring plant populations. The most successful progeny of parent genotypes had survival rates nearly 12 times higher than the least successful progeny. We speculate that many of these environmental and genetic factors are likely to influence allopatric congeners and other critically endangered gap specialists that grow in Florida scrub and our results can be used to guide their conservation. PMID:23593479

Comparative genet survival after fire in woody Mediterranean species.

PubMed

López-Soria, Luis; Castell, Carles

1992-10-01

Using data from three fires in northeastern Spain, we tested a condition necessary to support the idea that fire has been a factor in the evolution of the resprouting habit: populations of all resprouting species within a community should show high levels of genet survival after fires and show a low coefficient of variation. Species with high mean survival values were:Quercus ilex L.,Phillyrea latifolia L., andViburnum tinus L., with 88, 86 and 83% survival respectively; these groups had resprouts emerging from rootcrowns. Then followedArbutus unedo L. (75%),Pistacia lentiscus L. (73%),Erica arborea L. (77%),Erica multiflora L. (57%) andJuniperus oxycedrus L. (55%). This last group had resprouts from lignotubers or burls. These two groups also differed in the variability around the mean: the first showed a lower coefficient of variation, 6-12, and the second ranged from 19 to 26. Slope exposure had no significant influence on the process of resprouting, but soil depth did, with precipitation as a covariate. In the shallow soil category, the difference in genet survival between southern and northern exposures was 14% (71% vs. 57%); while the difference in the deep soil category was low, 5% (87% vs. 82%). There was no significant interaction. The component of variance for soils was larger than that for species-specific effects; substantial overlap of the within-species variance indicated that species responded as if they were a single hypothetical population, in which most of the variation in chances of survival was due to the soil conditions. The possession of the resprouting habit did not ensure a high performance. Hence, we find weak support for fire as a factor in the evolution of the resprouting habit.

Pup Mortality in a Rapidly Declining Harbour Seal (Phoca vitulina) Population

PubMed Central

Hanson, Nora; Thompson, Dave; Duck, Callan; Moss, Simon; Lonergan, Mike

2013-01-01

The harbour seal population in Orkney, off the north coast of Scotland, has reduced by 65% between 2001 and 2010. The cause(s) of this decline are unknown but must affect the demographic parameters of the population. Here, satellite telemetry data were used to test the hypothesis that increased pup mortality could be a primary driver of the decline in Orkney. Pup mortality and tag failure parameters were estimated from the duration of operation of satellite tags deployed on harbour seal pups from the Orkney population (n = 24) and from another population on the west coast of Scotland (n = 24) where abundance was stable. Survival probabilities from both populations were best represented by a common gamma distribution and were not different from one another, suggesting that increased pup mortality is unlikely to be the primary agent in the Orkney population decline. The estimated probability of surviving to 6 months was 0.390 (95% CI 0.297 – 0.648) and tag failure was represented by a Gaussian distribution, with estimated mean 270 (95% CI = 198 – 288) and s.d. 21 (95% CI = 1 – 66) days. These results suggest that adult survival is the most likely proximate cause of the decline. They also demonstrate a novel technique for attaining age-specific mortality rates from telemetry data. PMID:24312239

Adaptations of an RNA virus to increasing thermal stress

PubMed Central

Singhal, Sonia; Leon Guerrero, Cierra M.; Whang, Stella G.; McClure, Erin M.; Busch, Hannah G.; Kerr, Benjamin

2017-01-01

Environments can change in incremental fashions, where a shift from one state to another occurs over multiple organismal generations. The rate of the environmental change is expected to influence how and how well populations adapt to the final environmental state. We used a model system, the lytic RNA bacteriophage Φ6, to investigate this question empirically. We evolved viruses for thermostability by exposing them to heat shocks that increased to a maximum temperature at different rates. We observed increases in the ability of many heat-shocked populations to survive high temperature heat shocks. On their first exposure to the highest temperature, populations that experienced a gradual increase in temperature had higher average survival than populations that experienced a rapid temperature increase. However, at the end of the experiment, neither the survival of populations at the highest temperature nor the number of mutations per population varied significantly according to the rate of thermal change. We also evaluated mutations from the endpoint populations for their effects on viral thermostability and growth. As expected, some mutations did increase viral thermostability. However, other mutations decreased thermostability but increased growth rate, suggesting that benefits of an increased replication rate may have sometimes outweighed the benefits of enhanced thermostability. Our study highlights the importance of considering the effects of multiple selective pressures, even in environments where a single factor changes. PMID:29267297

Survival of Alzheimer's disease patients in Korea.

PubMed

Go, Seok Min; Lee, Kang Soo; Seo, Sang Won; Chin, Juhee; Kang, Sue J; Moon, So Young; Na, Duk L; Cheong, Hae-Kwan

2013-01-01

The natural history of Alzheimer's disease (AD) has rarely been studied in the Korean population. Our study on survival analyses in Korean AD patients potentially provides a basis for cross-cultural comparisons. We studied 724 consecutive patients from a memory disorder clinic in a tertiary hospital in Seoul, who were diagnosed as having AD between April 1995 and December 2005. Deaths were identified by the Statistics Korea database. The Kaplan-Meier method was used for survival analysis, and a Cox proportional hazard model was used to assess factors related to patient survival. The overall median survival from the onset of first symptoms and from the time of diagnosis was 12.6 years (95% confidence interval 11.7-13.4) and 9.3 years (95% confidence interval 8.7-9.9), respectively. The age of onset, male gender, history of diabetes mellitus, lower Mini-Mental State Examination score, and higher Clinical Dementia Rating score were negatively associated with survival. There was a reversal of risk of AD between early-onset and later-onset AD, 9.1 years after onset. The results of our study show a different pattern of survival compared to those studies carried out with western AD populations. Mortality risk of early-onset AD varied depending on the duration of follow-up. Copyright © 2013 S. Karger AG, Basel.

The effect of stochiastic technique on estimates of population viability from transition matrix models

USGS Publications Warehouse

Kaye, T.N.; Pyke, David A.

2003-01-01

Population viability analysis is an important tool for conservation biologists, and matrix models that incorporate stochasticity are commonly used for this purpose. However, stochastic simulations may require assumptions about the distribution of matrix parameters, and modelers often select a statistical distribution that seems reasonable without sufficient data to test its fit. We used data from long-term (5a??10 year) studies with 27 populations of five perennial plant species to compare seven methods of incorporating environmental stochasticity. We estimated stochastic population growth rate (a measure of viability) using a matrix-selection method, in which whole observed matrices were selected at random at each time step of the model. In addition, we drew matrix elements (transition probabilities) at random using various statistical distributions: beta, truncated-gamma, truncated-normal, triangular, uniform, or discontinuous/observed. Recruitment rates were held constant at their observed mean values. Two methods of constraining stage-specific survival to a??100% were also compared. Different methods of incorporating stochasticity and constraining matrix column sums interacted in their effects and resulted in different estimates of stochastic growth rate (differing by up to 16%). Modelers should be aware that when constraining stage-specific survival to 100%, different methods may introduce different levels of bias in transition element means, and when this happens, different distributions for generating random transition elements may result in different viability estimates. There was no species effect on the results and the growth rates derived from all methods were highly correlated with one another. We conclude that the absolute value of population viability estimates is sensitive to model assumptions, but the relative ranking of populations (and management treatments) is robust. Furthermore, these results are applicable to a range of perennial plants and possibly other life histories.

Factors influencing breeding success, ovarian cyclicity, and cub survival in zoo-managed tigers (Panthera tigris).

PubMed

Saunders, Sarah P; Harris, Tara; Traylor-Holzer, Kathy; Beck, Karen Goodrowe

2014-01-10

Understanding factors that influence reproduction and offspring survival in zoo populations is critical for management of threatened and endangered species. Examination of long-term data (1989-2011) compiled from the Association of Zoos and Aquarium's zoo-managed tiger breeding program provides the basis for a more thorough understanding of reproduction and scientifically based decisions for effective population management in this endangered felid. Biological and management-related factors that could influence tiger breeding success and cub survival were evaluated using logistic mixed models. Breeding success improved with female age until approximately age five, then declined thereafter. Experienced female breeders had greater breeding success than inexperienced females. Litter size was most predictive of cub survival, with average-sized litters (3-4 cubs) experiencing the highest proportional survival. Management-related factors, such as whether the breeding institution had a recent tiger litter and whether both animals were already located at the same institution, also influenced breeding success and cub survival. These results highlight the importance of institutional husbandry experience and the need to retain knowledge through staff turnovers to achieve optimal reproductive success. Using fecal estrogen data, frequency of ovarian cyclicity and mean cycle length did not differ by female age or parity; thus, lack of cyclicity and/or increased cycle duration are not likely explanations for declining breeding success with age. These results provide valuable reproductive information that should improve scientific management of zoo-based tiger populations. Copyright © 2013 Elsevier B.V. All rights reserved.

[Incidence and survival of esophageal cancer with different histological types in Linzhou between 2003 and 2012].

PubMed

Liu, S Z; Yu, L; Chen, Q; Quan, P L; Cao, X Q; Sun, X B

2017-05-06

Objective: To investigate the incidence and survival of esophageal cancer with different histological types and to understand the incidence trend and burden of esophageal cancer in Linzhou during 2003-2012. Methods: All incidence records of esophageal cancer and population reported were collected from Linzhou Cancer Registry during 2003-2012. Incidence rate was calculated using gender and histological types. Age standardized incidence rate was calculated according to world Segi's population and Chinese census data in 2000. Age standardized incidence rate by world population between 2003 and 2012 was analyzed with JoinPoint regression model and estimated annual percentage change (EAPC) was calculated. 5-year survival rate was calculated with Kaplan-Meier model. Results: There were 8 229 esophageal cancer cases in Linzhou during 2003-2012. The average annual incidence rate was 80.08/100 000 (8 229/10 276 481). Among all esophageal cancer cases, 7 019 (85.3%) were diagnosed as esophageal squamous cell carcinoma (ESCC). In Linzhou, the age standardized incidence rate by Chinese standard population and by world standard population was 80.92/100 000 and 81.85/100 000 in 2003, 67.97/100 000 and 68.63/100 000 in 2012. JoinPoint regression model showed that EAPC was-12.9% (95 %CI: -16.4%--9.1%) for other and unspecified histological type between 2003 and 2012. The EAPC was-5.5% (95 %CI: -9.2%--1.6%) for esophageal cancer between 2007 and 2012,-5.4% (95 %CI: -7.0%--3.9%) for esophageal cancer in female between 2006 and 2012,-4.9% (95 %CI: -9.5%--0.1%) for ESCC between 2007 and 2012. The 5-year prevalence of esophageal cancer was 215.49 per 100 000 (2 337/1 084 493), and 5 489 died within 5 years after incidence. 5-year survival rate of esophageal cancer was 34.6% (95 %CI: 33.5%-35.6%). Conclusion: Esophageal cancer had a decreasing trend in Linzhou. The survival rate was increasing. But, esophageal cancer was still a major burden in Linzhou. The major histological type was ESCC. ESCC had a similar decreasing trend with esophageal cancer.

Growth and survival of uninjured and sublethally heat-injured Escherichia coli O157:H7 on beef extract medium as influenced by package atmosphere and storage temperature.

PubMed

Semanchek, J J; Golden, D A; Williams, R C

1999-03-01

The effect of atmospheric composition and storage temperature on growth and survival of uninjured and sublethally heat-injured Escherichia coli O157:H7, inoculated onto brain heart infusion agar containing 0.3% beef extract (BEM), was determined. BEM plates were packaged in barrier bags in air, 100% CO2, 100% N2, 20% CO2: 80% N2, and vacuum and were stored at 4, 10, and 37 degrees C for up to 20 days. Package atmosphere and inoculum status (i.e., uninjured or heat-injured) influenced (P < 0.01) growth and survival of E. coli O157:H7 stored at all test temperatures. Growth of heat-injured E. coli O157:H7 was slower (P < 0.01) than uninjured E. coli O157:H7 stored at 37 degrees C. At 37 degrees C, uninjured E. coli O157:H7 reached stationary phase growth earlier than heat-injured populations. Uninjured E. coli O157:H7 grew during 10 days of storage at 10 degrees C, while heat-injured populations declined during 20 days of storage at 10 degrees C. Uninjured E. coli O157:H7 stored at 10 degrees C reached stationary phase growth within approximately 10 days in all packaging atmospheres except CO2. Populations of uninjured and heat-injured E. coli O157:H7 declined throughout storage for 20 days at 4 degrees C. Survival of uninjured populations stored at 4 degrees C, as well as heat-injured populations stored at 4 and 10 degrees C, was enhanced in CO2 atmosphere. Survival of heat-injured E. coli O157:H7 at 4 and 10 degrees C was not different (P > 0.05). Uninjured and heat-injured E. coli O157:H7 are able to survive at low temperatures in the modified atmospheres used in this study.

Mortality experience of the 1986-2000 National Health Interview Survey Linked Mortality Files participants.

PubMed

Ingram, Deborah D; Lochner, Kimberly A; Cox, Christine S

2008-10-01

The National Center for Health Statistics (NCHS) has produced the 1986-2000 National Health Interview Survey (NHIS) Linked Mortality Files by linking eligible adults in the 1986-2000 NHIS cohorts through probabilistic record linkage to the National Death Index to obtain mortality follow-up through December 31, 2002. The resulting files contain more than 120,000 deaths and an average of 9 years of survival time. To assess how well mortality was ascertained in the linked mortality files, NCHS has conducted a comparison of the mortality experience of the 1986-2000 NHIS cohorts with that of the U.S. population. This report presents the results of this comparative mortality assessment. Methods The survival of each annual NHIS cohort was compared with that of the U.S. population during the same period. Cumulative survival probabilities for each annual NHIS cohort were derived using the Kaplan-Meier product limit method, and corresponding cumulative survival probabilities were computed for the U.S. population using information from annual U.S. life tables. The survival probabilities were calculated at various lengths of follow-up for each age-race-sex group of each NHIS cohort and for the U.S. population. Results As expected, mortality tended to be underestimated in the NHIS cohorts because the sample includes only civilian, noninstitutionalized persons, but this underestimation generally was not statistically significant. Statistically significant differences increased with length of follow-up, occurred more often for white females than for the other race-sex groups, and occurred more often in the oldest age groups. In general, the survival experience of the age-race-sex groups of each NHIS cohort corresponds quite closely to that of the U.S. population, providing support that the ascertainment of mortality through the probabilistic record linkage accurately reflects the mortality experience of the NHIS cohorts.

Mutation supply and the repeatability of selection for antibiotic resistance

NASA Astrophysics Data System (ADS)

van Dijk, Thomas; Hwang, Sungmin; Krug, Joachim; de Visser, J. Arjan G. M.; Zwart, Mark P.

2017-10-01

Whether evolution can be predicted is a key question in evolutionary biology. Here we set out to better understand the repeatability of evolution, which is a necessary condition for predictability. We explored experimentally the effect of mutation supply and the strength of selective pressure on the repeatability of selection from standing genetic variation. Different sizes of mutant libraries of antibiotic resistance gene TEM-1 β-lactamase in Escherichia coli, generated by error-prone PCR, were subjected to different antibiotic concentrations. We determined whether populations went extinct or survived, and sequenced the TEM gene of the surviving populations. The distribution of mutations per allele in our mutant libraries followed a Poisson distribution. Extinction patterns could be explained by a simple stochastic model that assumed the sampling of beneficial mutations was key for survival. In most surviving populations, alleles containing at least one known large-effect beneficial mutation were present. These genotype data also support a model which only invokes sampling effects to describe the occurrence of alleles containing large-effect driver mutations. Hence, evolution is largely predictable given cursory knowledge of mutational fitness effects, the mutation rate and population size. There were no clear trends in the repeatability of selected mutants when we considered all mutations present. However, when only known large-effect mutations were considered, the outcome of selection is less repeatable for large libraries, in contrast to expectations. We show experimentally that alleles carrying multiple mutations selected from large libraries confer higher resistance levels relative to alleles with only a known large-effect mutation, suggesting that the scarcity of high-resistance alleles carrying multiple mutations may contribute to the decrease in repeatability at large library sizes.

The effects of dietary protein levels on the population growth, performance, and physiology of honey bee workers during early spring.

PubMed

Zheng, Benle; Wu, Zaifu; Xu, Baohua

2014-01-01

This study was conducted to investigate the effects of dietary protein levels on honey bee colonies, specifically the population growth, physiology, and longevity of honey bee workers during early spring. Diets containing four different levels of crude protein (25.0, 29.5, 34.0, or 38.5%) and pure pollen (control) were evaluated. Twenty-five colonies of honey bees with sister queens were used in the study. We compared the effects of the different bee diets by measuring population growth, emergent worker weight, midgut proteolytic enzyme activity, hypopharyngeal gland development, and survival. After 48 d, the cumulative number of workers produced by the colonies ranged from 22,420 to 29,519, providing a significant fit to a quadratic equation that predicts the maximum population growth when the diet contains 31.7% crude protein. Significantly greater emergent worker weight, midgut proteolytic enzyme activity, hypopharyngeal gland acini, and survival were observed in the colonies that were fed diets containing 34.0% crude protein compared with the other crude protein levels. Although higher emergent worker weight and survival were observed in the colonies that were fed the control diet, there were no significant differences between the control colonies and the colonies that were fed 34.0% crude protein. Based on these results, we concluded that a dietary crude protein content of 29.5-34.0% is recommended to maximize the reproduction rate of honey bee colonies in early spring. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Comparison of outcomes in Australian indigenous and non-indigenous children and adolescents undergoing cardiac surgery.

PubMed

Justo, Edward R; Reeves, Benjamin M; Ware, Robert S; Johnson, Janelle C; Karl, Tom R; Alphonso, Nelson D; Justo, Robert N

2017-11-01

Population-based registries report 95% 5-year survival for children undergoing surgery for CHD. This study investigated paediatric cardiac surgical outcomes in the Australian indigenous population. All children who underwent cardiac surgery between May, 2008 and August, 2014 were studied. Demographic information including socio-economic status, diagnoses and co-morbidities, and treatment and outcome data were collected at time of surgery and at last follow-up. A total of 1528 children with a mean age 3.4±4.6 years were studied. Among them, 123 (8.1%) children were identified as indigenous, and 52.7% (62) of indigenous patients were in the lowest third of the socio-economic index compared with 28.2% (456) of non-indigenous patients (p⩽0.001). The indigenous sample had a significantly higher Comprehensive Aristotle Complexity score (indigenous 9.4±4.2 versus non-indigenous 8.7±3.9, p=0.04). The probability of having long-term follow-up did not differ between groups (indigenous 93.8% versus non-indigenous 95.6%, p=0.17). No difference was noted in 30-day mortality (indigenous 3.2% versus non-indigenous 1.4%, p=0.13). The 6-year survival for the entire cohort was 95.9%. The Cox survival analysis demonstrated higher 6-year mortality in the indigenous group - indigenous 8.1% versus non-indigenous 5.0%; hazard ratio (HR)=2.1; 95% confidence intervals (CI): 1.1, 4.2; p=0.03. Freedom from surgical re-intervention was 79%, and was not significantly associated with the indigenous status (HR=1.4; 95% CI: 0.9, 1.9; p=0.11). When long-term survival was adjusted for the Comprehensive Aristotle Complexity score, no difference in outcomes between the populations was demonstrated (HR=1.6; 95% CI: 0.8, 3.2; p=0.19). The indigenous population experienced higher late mortality. This apparent relationship is explained by increased patient complexity, which may reflect negative social and environmental factors.

Development of National Program of Cancer Registries SAS Tool for Population-Based Cancer Relative Survival Analysis.

PubMed

Dong, Xing; Zhang, Kevin; Ren, Yuan; Wilson, Reda; O'Neil, Mary Elizabeth

2016-01-01

Studying population-based cancer survival by leveraging the high-quality cancer incidence data collected by the Centers for Disease Control and Prevention's National Program of Cancer Registries (NPCR) can offer valuable insight into the cancer burden and impact in the United States. We describe the development and validation of a SASmacro tool that calculates population-based cancer site-specific relative survival estimates comparable to those obtained through SEER*Stat. The NPCR relative survival analysis SAS tool (NPCR SAS tool) was developed based on the relative survival method and SAS macros developed by Paul Dickman. NPCR cancer incidence data from 25 states submitted in November 2012 were used, specifically cases diagnosed from 2003 to 2010 with follow-up through 2010. Decennial and annual complete life tables published by the National Center for Health Statistics (NCHS) for 2000 through 2009 were used. To assess comparability between the 2 tools, 5-year relative survival rates were calculated for 25 cancer sites by sex, race, and age group using the NPCR SAS tool and the National Cancer Institute's SEER*Stat 8.1.5 software. A module to create data files for SEER*Stat was also developed for the NPCR SAS tool. Comparison of the results produced by both SAS and SEER*Stat showed comparable and reliable relative survival estimates for NPCR data. For a majority of the sites, the net differences between the NPCR SAS tool and SEER*Stat-produced relative survival estimates ranged from -0.1% to 0.1%. The estimated standard errors were highly comparable between the 2 tools as well. The NPCR SAS tool will allow researchers to accurately estimate cancer 5-year relative survival estimates that are comparable to those produced by SEER*Stat for NPCR data. Comparison of output from the NPCR SAS tool and SEER*Stat provided additional quality control capabilities for evaluating data prior to producing NPCR relative survival estimates.

Atrial Fibrillation and Cardiovascular Comorbidities, Survival and Mortality: A Real-Life Observational Study

PubMed Central

Clua-Espuny, Jose Luis; Panisello-Tafalla, Anna; Lopez-Pablo, Carlos; Lechuga-Duran, Inigo; Bosch-Princep, Ramon; Lucas-Noll, Jorgina; Gonzalez-Henares, Antonia; Queralt-Tomas, Lluisa; Ripolles-Vicente, Rosa; Calduch-Noll, Cristina; Gonzalez-Rojas, Nuria; Gallofre-Lopez, Miguel

2014-01-01

Background Atrial fibrillation (AF) is the most common cardiac tachyarrhythmia encountered in clinical practice affecting up to 10% of the population over 60 years old and its prevalence rises with age. The main goals were to characterize the AF patient population after the initial diagnosis of AF and to determine overall survival. Methods It is a real-life observational study of 269 subjects with an AF diagnosis over 60 years old randomly selected. The collected variables were: sociodemographic, cardiovascular complications/comorbidities (CVCs) included in the CHA2DS2-VASc and HAS_BLED scores, drug assigned as clinical treatment, mean range INR and CVCs and death dates (all-cause mortality). The survival curve and the risk of death were assessed using Kaplan-Meier survival curve and comparisons with log-rank. Results The average following time was 6.2 ± 3.7 years (0.2-20.4). Eleven point five percent died. Sixty-five point four percent had some CVCs. There were no differences in the overall incidence of CVCs by gender. The survival probability was 0.86 ± DE 0.03 among men and 0.90 ± DE 0.04 among women without differences. Thirty-six point eight percent (95% CI: 30.8 - 42.7) were diagnosed vascular complications before AF diagnosis, being ischemic cardiopathy (24.2%) and ischemic stroke (23.2%) the most frequent. The mortality is higher (P < 0.036) among those who suffered ≥ 3 vascular complications and significantly lower among those treated with statins (P = 0.032). After AF diagnosis, the most frequent was the cardiac heart failure (46.7%), significantly higher among women (P = 0.037). The mortality is significantly lower in those treated with OAC (P = 0.003). Conclusions AF is associated with ischemic heart disease, ischemic stroke and congestive heart failure, but the average mortality age is not different from the global population in Spain and Catalonia. PMID:28392870

Incidence and early outcomes associated with pre-transplant antivimentin antibodies in the cardiac transplantation population.

PubMed

Young, Raymond K; Dale, Bethany; Russell, Stuart D; Zachary, Andrea A; Tedford, Ryan J

2015-08-01

In cardiac transplant recipients, the development of antibodies to the endothelial intermediate filament protein vimentin (antivimentin antibodies, AVA) has been associated with rejection and poor outcomes. However, the incidence of these antibodies prior to transplantation and their association with early rejection has not been investigated. Pre-transplant serum was analyzed from 50 patients who underwent de novo cardiac transplant at Johns Hopkins Hospital from 2004 to 2012. Demographic, one-yr rejection, and survival data were obtained from the transplant database. The incidence of pre-transplant AVA was 34%. AVA-positive patients were younger (p = 0.03), and there was an a trend toward incidence in females (p = 0.08). Demographic data were similar among both groups. AVA positivity did not predict rejection in the first year post-transplant. There was no difference in rejection-free graft survival (53 vs. 52%, p = 0.85) at one yr. Similarly, there was no difference in graft survival at one yr (82 vs. 88%, p = 0.56) or graft survival at a median follow-up of 23 and 26 months, respectively (76 vs. 85%, p = 0.41). AVA is common in the cardiac pre-transplant population with a higher incidence in the young. The presence of detectable AVA did not correlate with early post-transplant rejection or graft survival. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

INCIDENCE AND EARLY OUTCOMES ASSOCIATED WITH PRE-TRANSPLANT ANTI-VIMENTIN ANTIBODIES IN THE CARDIAC TRANSPLANTATION POPULATION

PubMed Central

Young, Raymond K.; Dale, Bethany; Russell, Stuart D.; Zachary, Andrea A.; Tedford, Ryan J.

2015-01-01

Background In cardiac transplant recipients, the development of antibodies to the endothelial intermediate filament protein vimentin (anti-vimentin antibodies, AVA) has been associated with rejection and poor outcomes. However, the incidence of these antibodies prior to transplantation and their association with early rejection has not been investigated. Methods Pre-transplant serum was analyzed from 50 patients who underwent de novo cardiac transplant at Johns Hopkins Hospital from 2004-2012. Demographic, one year rejection, and survival data were obtained from the transplant database. Results The incidence of pre-transplant AVA was 34%. AVA positive patients were younger (p=0.03) and there was an increased incidence in females (p=0.08). Demographic data were similar among both groups. AVA positivity did not predict rejection in the 1st year post-transplant. There was no difference in rejection-free graft survival (53 vs. 52%, p=0.85) at 1 year. Similarly there was no difference in graft survival at 1 year (82 vs. 88%, p=0.56) or graft survival at a median follow up of 23 and 26 months, respectively (76 vs. 85%, p=0.41). Conclusions AVA is common in the cardiac pre-transplant population with a higher incidence in the young. The presence of detectable AVA did not correlate with early post-transplant rejection or graft survival. PMID:25982351

Ovarian cancer survival population differences: a "high resolution study" comparing Philippine residents, and Filipino-Americans and Caucasians living in the US.

PubMed

Redaniel, Maria Theresa M; Laudico, Adriano; Mirasol-Lumague, Maria Rica; Gondos, Adam; Uy, Gemma Leonora; Toral, Jean Ann; Benavides, Doris; Brenner, Hermann

2009-09-24

In contrast to most other forms of cancer, data from some developing and developed countries show surprisingly similar survival rates for ovarian cancer. We aimed to compare ovarian cancer survival in Philippine residents, Filipino-Americans and Caucasians living in the US, using a high resolution approach, taking potential differences in prognostic factors into account. Using databases from the SEER 13 and from the Manila and Rizal Cancer Registries, age-adjusted five-year absolute and relative survival estimates were computed using the period analysis method and compared between Filipino-American ovarian cancer patients with cancer patients from the Philippines and Caucasians in the US. Cox proportional hazards modelling was used to determine factors affecting survival differences. Despite more favorable distribution of age and cancer morphology and similar stage distribution, 5-year absolute and relative survival were lower in Philippine residents (Absolute survival, AS, 44%, Standard Error, SE, 2.9 and Relative survival, RS, 49.7%, SE, 3.7) than in Filipino-Americans (AS, 51.3%, SE, 3.1 and RS, 54.1%, SE, 3.4). After adjustment for these and additional covariates, strong excess risk of death for Philippine residents was found (Relative Risk, RR, 2.45, 95% confidence interval, 95% CI, 1.99-3.01). In contrast, no significant differences were found between Filipino-Americans and Caucasians living in the US. Multivariate analyses disclosed strong survival disadvantages of Philippine residents compared to Filipino-American patients, for which differences in access to health care might have played an important role. Survival is no worse among Filipino-Americans than among Caucasians living in the US.

[Is survival enough? Challenges of the integration of health and well-being in the third world].

PubMed

Brachet-Márquez, V

1992-01-01

In this paper the paths taken by developing countries to improve the health and well-being of their populations in a context of diminishing resources is discussed. Emphasis is placed on Latin American countries and the objective is to clarify the changing nature of the relationship between health and social well-being in the 1970s and 1980s. In the second part of the paper three viable and different political scenarios to confront this problem are presented: 1) survival without well-being; 2) survival and eradication of extreme poverty, and 3) survival, eradication of extreme poverty, and selective reconversion of the poor.

Mortality risks and limits to population growth of fishers

Treesearch

Rick A. Sweitzer; Viorel D. Popescu; Craig M. Thompson; Kathryn L. Purcell; Reginald H. Barrett; Greta M. Wengert; Mourad W. Gabriel; Leslie W. Woods

2015-01-01

Fishers (Pekania pennanti) in the west coast states of Washington, Oregon, and California, USA have not recovered from population declines and the United States Fish and Wildlife Service has proposed options for listing them as threatened. Our objectives were to evaluate differences in survival and mortality risk from natural (e.g., predation, disease, injuries,...

Population dynamics of the California Spotted Owl (Strix occidentalis occidentalis): a meta-analysis

USGS Publications Warehouse

Franklin, A.B.; Gutierrez, R.J.; Nichols, J.D.; Seamans, M.E.; White, Gary C.; Zimmerman, G.S.; Hines, J.E.; Munton, T.E.; LaHaye, W.S.; Blakesley, J.A.; Steger, G.N.; Noon, B.R.; Shaw, D.W.H.; Keane, J.J.; McDonald, T.L.; Britting, S.

2004-01-01

We conducted a meta-analysis to provide a current assessment of the population characteristics of California Spotted Owls (Strix occidentalis occidentalis) resident on four study areas in the Sierra Nevada and one study area in southern California. Our meta-analysis followed rigorous a priori analysis protocols, which we derived through extensive discussion during a week-long analysis workshop. Because there is great interest in the owl?s population status, we used state-of-the-art analytical methods to obtain results as precise as possible. Our meta-analysis included data from five California study areas located on the Lassen National Forest (1990-2000), Eldorado National Forest (1986-2000), Sierra National Forest (1990-2000), Sequoia and Kings Canyon national parks (1990-2000), and San Bernardino National Forest (1987-1998). Four of the five study areas spanned the length of the Sierra Nevada, whereas the fifth study area encompassed the San Bernardino Mountains in southern California. Study areas ranged in size from 343 km2 (Sequoia and Kings Canyon) to 2,200 km (Lassen). All studies were designed to use capture-recapture methods and analysis. We used survival in a meta-analysis because field methods were very similar among studies. However, we did not use reproduction in a meta-analysis because it was not clear if variation among individual study-area protocols used to assess reproductive output of owls would confound results. Thus, we analyzed fecundity only by individual study area. We examined population trend using the reparameterized Jolly-Seber capture-recapture estimator (8t) We did not estimate juvenile survival rates because of estimation problems and potential bias because of juvenile emigration from study areas. We used mark-recapture estimators under an information theoretic framework to assess apparent survival rates of adult owls. The pooled estimate for adult apparent survival for the five study areas was 0.833, which was lower than pooled adult survival rates (0.850) from 15 Northern Spotted Owl (S. o. caurina) studies. Estimates of survival from the best model on the Lassen (N = 0.829, 95% confidence intervals [CI = 0.798 to 0.857), Eldorado (N = 0.815, 95% CI = 0.772 to 0.851), Sierra (N = 0.818, 95% CI = 0.781 to 0.850), and San Bernardino (N = 0.813, 95% CI = 0.782 to 0.841) were not different. However, the Sequoia and Kings Canyon population had a higher survival rate (N = 0.877, 95% CI = 0.842 to 0.905) than the other study areas. Management history and forest structure (e.g. presence of giant sequoia [Sequoiadendron giganteum]) on the Sequoia and Kings Canyon study area differed from all other study areas. There appears to be little or no evidence for temporal variation in adult apparent survival on any of the study areas. Although we did not directly compare fecundity estimates were highly variable among years within all study areas (CV of temporal process variation = 0.672-0.817). Estimates for fecundity among the study populations were Lassen (b = 0.336, SE = 0.083), Eldorado (b = 0.409, SE = 0.087), Sierra (b = 0.284, SE = 0.073), Sequoia and Kings Canyon (b = 0.289, SE = 0.074), and San Bernardino (b = 0.362, SE = 0.038). During most years, the Sierra Nevada populations showed either moderate or poor fecundity. However, 1992 appeared to be an exceptional reproductive year for owls in the Sierra Nevada. In contrast, the San Bernardino population had less variable reproduction (CV of temporal process variation = 0.217), but experienced neither the exceptional reproduction of 1992 nor the extremely poor years that characterized all of the Sierra Nevada study areas. Because fecundity may be influenced by weather patterns, it was possible that the different weather patterns between southern California and the Sierra Nevada accounted for that difference. Except for Eldorado, all estimates for 8t, were <1.0, but none was different from 8 = 1.0 given the 95% confidence i

Growth, survival, longevity, and population size of the Big Mouth Cave salamander (Gyrinophilus palleucus necturoides) from the type locality in Grundy County, Tennessee, USA

USGS Publications Warehouse

Niemiller, Matthew L.; Glorioso, Brad M.; Fenolio, Dante B.; Reynolds, R. Graham; Taylor, Steven J.; Miller, Brian T.

2016-01-01

Salamander species that live entirely in subterranean habitats have evolved adaptations that allow them to cope with perpetual darkness and limited energy resources. We conducted a 26-month mark–recapture study to better understand the individual growth and demography of a population of the Big Mouth Cave Salamander (Gyrinophilus palleucus necturoides). We employed a growth model to estimate growth rates, age at sexual maturity, and longevity, and an open population model to estimate population size, density, detectability, and survival rates. Furthermore, we examined cover use and evidence of potential predation. Individuals probably reach sexual maturity in 3–5 years and live at least nine years. Survival rates were generally high (>75%) but declined during the study. More than 30% of captured salamanders had regenerating tails or tail damage, which presumably represent predation attempts by conspecifics or crayfishes. Most salamanders (>90%) were found under cover (e.g., rocks, trash, decaying plant material). Based on 11 surveys during the study, population size estimates ranged from 21 to 104 individuals in the ca. 710 m2 study area. Previous surveys indicated that this population experienced a significant decline from the early 1970s through the 1990s, perhaps related to silvicultural and agricultural practices. However, our data suggest that this population has either recovered or stabilized during the past 20 years. Differences in relative abundance between early surveys and our survey could be associated with differences in survey methods or sampling conditions rather than an increase in population size. Regardless, our study demonstrates that this population is larger than previously thought and is in no immediate risk of extirpation, though it does appear to exhibit higher rates of predation than expected for a species believed to be an apex predator of subterranean food webs.

Microbial abundance on the eggs of a passerine bird and related fitness consequences between urban and rural habitats

PubMed Central

Lee, Sang-im; Lee, Hyunna; Jablonski, Piotr G.; Choe, Jae Chun

2017-01-01

Urban environments present novel and challenging habitats to wildlife. In addition to well-known difference in abiotic factors between rural and urban environments, the biotic environment, including microbial fauna, may also differ significantly. In this study, we aimed to compare the change in microbial abundance on eggshells during incubation between urban and rural populations of a passerine bird, the Eurasian Magpie (Pica pica), and examine the consequences of any differences in microbial abundances in terms of hatching success and nestling survival. Using real-time PCR, we quantified the abundances of total bacteria, Escherichia coli/Shigella spp., surfactin-producing Bacillus spp. and Candida albicans on the eggshells of magpies. We found that urban magpie eggs harboured greater abundances of E. coli/Shigella spp. and C. albicans before incubation than rural magpie eggs. During incubation, there was an increase in the total bacterial load, but a decrease in C. albicans on urban eggs relative to rural eggs. Rural eggs showed a greater increase in E. coli/Shigella spp. relative to their urban counterpart. Hatching success of the brood was generally lower in urban than rural population. Nestling survival was differentially related with the eggshell microbial abundance between urban and rural populations, which was speculated to be the result of the difference in the strength of the interaction among the microbes. This is the first demonstration that avian clutches in urban and rural populations differ in eggshell microbial abundance, which can be further related to the difference in hatching success and nestling survival in these two types of environments. We suggest that future studies on the eggshell microbes should investigate the interaction among the microbes, because the incubation and/or environmental factors such as urbanization or climate condition can influence the dynamic interactions among the microbes on the eggshells which can further determine the breeding success of the parents. PMID:28953940

Microbial abundance on the eggs of a passerine bird and related fitness consequences between urban and rural habitats.

PubMed

Lee, Sang-Im; Lee, Hyunna; Jablonski, Piotr G; Choe, Jae Chun; Husby, Magne

2017-01-01

Urban environments present novel and challenging habitats to wildlife. In addition to well-known difference in abiotic factors between rural and urban environments, the biotic environment, including microbial fauna, may also differ significantly. In this study, we aimed to compare the change in microbial abundance on eggshells during incubation between urban and rural populations of a passerine bird, the Eurasian Magpie (Pica pica), and examine the consequences of any differences in microbial abundances in terms of hatching success and nestling survival. Using real-time PCR, we quantified the abundances of total bacteria, Escherichia coli/Shigella spp., surfactin-producing Bacillus spp. and Candida albicans on the eggshells of magpies. We found that urban magpie eggs harboured greater abundances of E. coli/Shigella spp. and C. albicans before incubation than rural magpie eggs. During incubation, there was an increase in the total bacterial load, but a decrease in C. albicans on urban eggs relative to rural eggs. Rural eggs showed a greater increase in E. coli/Shigella spp. relative to their urban counterpart. Hatching success of the brood was generally lower in urban than rural population. Nestling survival was differentially related with the eggshell microbial abundance between urban and rural populations, which was speculated to be the result of the difference in the strength of the interaction among the microbes. This is the first demonstration that avian clutches in urban and rural populations differ in eggshell microbial abundance, which can be further related to the difference in hatching success and nestling survival in these two types of environments. We suggest that future studies on the eggshell microbes should investigate the interaction among the microbes, because the incubation and/or environmental factors such as urbanization or climate condition can influence the dynamic interactions among the microbes on the eggshells which can further determine the breeding success of the parents.

GONe: Software for estimating effective population size in species with generational overlap

USGS Publications Warehouse

Coombs, J.A.; Letcher, B.H.; Nislow, K.H.

2012-01-01

GONe is a user-friendly, Windows-based program for estimating effective size (N e) in populations with overlapping generations. It uses the Jorde-Ryman modification to the temporal method to account for age structure in populations. This method requires estimates of age-specific survival and birth rate and allele frequencies measured in two or more consecutive cohorts. Allele frequencies are acquired by reading in genotypic data from files formatted for either GENEPOP or TEMPOFS. For each interval between consecutive cohorts, N e is estimated at each locus and over all loci. Furthermore, N e estimates are output for three different genetic drift estimators (F s, F c and F k). Confidence intervals are derived from a chi-square distribution with degrees of freedom equal to the number of independent alleles. GONe has been validated over a wide range of N e values, and for scenarios where survival and birth rates differ between sexes, sex ratios are unequal and reproductive variances differ. GONe is freely available for download at. ?? 2011 Blackwell Publishing Ltd.

Life expectancy of colon, breast, and testicular cancer patients: an analysis of US-SEER population-based data.

PubMed

Capocaccia, R; Gatta, G; Dal Maso, L

2015-06-01

Cancer survivorship is an increasingly important issue in cancer control. Life expectancy of patients diagnosed with breast, colon, and testicular cancers, stratified by age at diagnosis and time since diagnosis, is provided as an indicator to evaluate future mortality risks and health care needs of cancer survivors. The standard period life table methodology was applied to estimate excess mortality risk for cancer patients diagnosed in 1985-2011 from SEER registries and mortality data of the general US population. The sensitivity of life expectancy estimates on different assumptions was evaluated. Younger patients with colon cancer showed wider differences in life expectancy compared with that of the general population (11.2 years in women and 10.7 in men at age 45-49 years) than older patients (6.3 and 5.8 at age 60-64 years, respectively). Life expectancy progressively increases in patients surviving the first years, up to 4 years from diagnosis, and then starts to decrease again, approaching that of the general population. For breast cancer, the initial drop in life expectancy is less marked, and again with wider differences in younger patients, varying from 8.7 at age 40-44 years to 2.4 at ages 70-74 years. After diagnosis, life expectancy still decreases with time, but less than that in the general population, slowly approaching that of cancer-free women. Life expectancy of men diagnosed with testicular cancer at age 30 years is estimated as 45.2 years, 2 years less than cancer-free men of the same age. The difference becomes 1.3 years for patients surviving the first year, and then slowly approaches zero with increasing survival time. Life expectancy provides meaningful information on cancer patients, and can help in assessing when a cancer survivor can be considered as cured. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Nest and chick survival and colony-site dynamics of least terns in the U.S. Virgin Islands

USGS Publications Warehouse

Lombard, Claudia D.; Collazo, Jaime; McNair, Douglas B.

2010-01-01

We report nest and chick survival and colony-site dynamics of the Least Tern (Sternula antillarum). These results are the first for the Caribbean and were derived with likelihood-based approaches from 4640 nests and 44 chicks fitted with transmitters monitored in 52 colonies at St. Croix, U.S. Virgin Islands, 2003–2006. Managed colonies excluded, overall daily nest survival (±SE) was 0.92 ± 0.03 (period survival = 0.18). Daily nest survival of managed colonies (fenced) was significantly higher (0.97 ± 0.02; period survival = 0.51). Variation in nest survival was best explained by a negative linear trend in daily survival, influenced by year, rain, large colony size, and nesting habitat. Daily nest-survival rates at sandy beaches (0.94 ± 0.02), offshore cays (0.93 ± 0.005), and saltflats (0.91 ± 0.02) did not differ significantly. The period survival of chicks was 0.30 ± 0.11. Estimated fledglings per nest attempt were 0.06. Demographic assessments suggested that higher reproductive rates are required for maintenance (λ ≥ 1). Managed colonies could meet nest-survival thresholds, but complementary measures are needed to increase chick survival. Our findings suggest that management should target sites harboring large colonies because they had higher nest success and higher probability of use in subsequent seasons. The colonies' site dynamics suggested that immigration from other populations is plausible. This possibility relaxes breeding-productivity thresholds and advocates for coordinated conservation among populations on neighboring islands. Estimates of age-specific survival and connectivity are needed for the status of the species to be assessed appropriately and conservation priorities set.

Rapid expansion of the invasive oyster Crassostrea gigas at its northern distribution limit in Europe: Naturally dispersed or introduced?

PubMed Central

Anglès d’Auriac, Marc B.; Norling, Pia; Lapègue, Sylvie; Staalstrøm, André; Hjermann, Dag Ø.; Thaulow, Jens

2017-01-01

The Pacific oyster, Crassostrea gigas, was introduced to Europe for aquaculture purposes, and has had a rapid and unforeseen northward expansion in northern Europe. The recent dramatic increase in number of C. gigas populations along the species’ northern distribution limit has questioned the efficiency of Skagerrak as a dispersal barrier for transport and survival of larvae. We investigated the genetic connectivity and possible spreading patterns between Pacific oyster populations on the southern Norwegian coast (4 localities) and Swedish and Danish populations by means of DNA microsatellite analysis of adult oysters, and by simulating larvae drift. In the simulations we used a 3D oceanographic model to explore the influence of recent climate change (1990–2010) on development, survival, and successful spreading of Danish and Swedish Pacific oyster larvae to Norwegian coastal waters. The simulations indicated adequate temperature conditions for development, survival, and settlement of larvae across the Skagerrak in warm years since 2000. However, microsatellite genotyping revealed genetic differences between the Norwegian populations, and between the Norwegian populations and the Swedish and Danish populations, the latter two populations being more similar. This patchwork pattern of genetic dissimilarity among the Norwegian populations points towards multiple local introduction routes rather than the commonly assumed unidirectional entry of larvae drifted from Denmark and Sweden. Alternative origins of introduction and implications for management, such as forecasting and possible mitigation actions, are discussed. PMID:28486520

Drought survival is a threshold function of habitat size and population density in a fish metapopulation.

PubMed

White, Richard S A; McHugh, Peter A; McIntosh, Angus R

2016-10-01

Because smaller habitats dry more frequently and severely during droughts, habitat size is likely a key driver of survival in populations during climate change and associated increased extreme drought frequency. Here, we show that survival in populations during droughts is a threshold function of habitat size driven by an interaction with population density in metapopulations of the forest pool dwelling fish, Neochanna apoda. A mark-recapture study involving 830 N. apoda individuals during a one-in-seventy-year extreme drought revealed that survival during droughts was high for populations occupying pools deeper than 139 mm, but declined steeply in shallower pools. This threshold was caused by an interaction between increasing population density and drought magnitude associated with decreasing habitat size, which acted synergistically to increase physiological stress and mortality. This confirmed two long-held hypotheses, firstly concerning the interactive role of population density and physiological stress, herein driven by habitat size, and secondly, the occurrence of drought survival thresholds. Our results demonstrate how survival in populations during droughts will depend strongly on habitat size and highlight that minimum habitat size thresholds will likely be required to maximize survival as the frequency and intensity of droughts are projected to increase as a result of global climate change. © 2016 John Wiley & Sons Ltd.

Worldwide comparison of survival from childhood leukaemia for 1995-2009, by subtype, age, and sex (CONCORD-2): a population-based study of individual data for 89 828 children from 198 registries in 53 countries.

PubMed

Bonaventure, Audrey; Harewood, Rhea; Stiller, Charles A; Gatta, Gemma; Clavel, Jacqueline; Stefan, Daniela C; Carreira, Helena; Spika, Devon; Marcos-Gragera, Rafael; Peris-Bonet, Rafael; Piñeros, Marion; Sant, Milena; Kuehni, Claudia E; Murphy, Michael F G; Coleman, Michel P; Allemani, Claudia

2017-05-01

Global inequalities in access to health care are reflected in differences in cancer survival. The CONCORD programme was designed to assess worldwide differences and trends in population-based cancer survival. In this population-based study, we aimed to estimate survival inequalities globally for several subtypes of childhood leukaemia. Cancer registries participating in CONCORD were asked to submit tumour registrations for all children aged 0-14 years who were diagnosed with leukaemia between Jan 1, 1995, and Dec 31, 2009, and followed up until Dec 31, 2009. Haematological malignancies were defined by morphology codes in the International Classification of Diseases for Oncology, third revision. We excluded data from registries from which the data were judged to be less reliable, or included only lymphomas, and data from countries in which data for fewer than ten children were available for analysis. We also excluded records because of a missing date of birth, diagnosis, or last known vital status. We estimated 5-year net survival (ie, the probability of surviving at least 5 years after diagnosis, after controlling for deaths from other causes [background mortality]) for children by calendar period of diagnosis (1995-99, 2000-04, and 2005-09), sex, and age at diagnosis (<1, 1-4, 5-9, and 10-14 years, inclusive) using appropriate life tables. We estimated age-standardised net survival for international comparison of survival trends for precursor-cell acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML). We analysed data from 89 828 children from 198 registries in 53 countries. During 1995-99, 5-year age-standardised net survival for all lymphoid leukaemias combined ranged from 10·6% (95% CI 3·1-18·2) in the Chinese registries to 86·8% (81·6-92·0) in Austria. International differences in 5-year survival for childhood leukaemia were still large as recently as 2005-09, when age-standardised survival for lymphoid leukaemias ranged from 52·4% (95% CI 42·8-61·9) in Cali, Colombia, to 91·6% (89·5-93·6) in the German registries, and for AML ranged from 33·3% (18·9-47·7) in Bulgaria to 78·2% (72·0-84·3) in German registries. Survival from precursor-cell ALL was very close to that of all lymphoid leukaemias combined, with similar variation. In most countries, survival from AML improved more than survival from ALL between 2000-04 and 2005-09. Survival for each type of leukaemia varied markedly with age: survival was highest for children aged 1-4 and 5-9 years, and lowest for infants (younger than 1 year). There was no systematic difference in survival between boys and girls. Global inequalities in survival from childhood leukaemia have narrowed with time but remain very wide for both ALL and AML. These results provide useful information for health policy makers on the effectiveness of health-care systems and for cancer policy makers to reduce inequalities in childhood cancer survival. Canadian Partnership Against Cancer, Cancer Focus Northern Ireland, Cancer Institute New South Wales, Cancer Research UK, US Centers for Disease Control and Prevention, Swiss Re, Swiss Cancer Research foundation, Swiss Cancer League, and the University of Kentucky. Copyright © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license. Published by Elsevier Ltd.. All rights reserved.

Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary

USGS Publications Warehouse

Hayden, Todd A.; Binder, Thomas; Holbrook, Christopher; Vandergoot, Christopher; Fielder, David G.; Cooke, Steven J.; Dettmers, John M.; Krueger, Charles C.

2018-01-01

Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.

Experimental evolution in Drosophila melanogaster: interaction of temperature and food quality selection regimes.

PubMed

Bochdanovits, Zoltán; de Jong, Gerdien

2003-08-01

In Drosophila, both the phenotypic and evolutionary effect of temperature on adult size involves alterations to larval resource processing and affects other life-history traits, that is, development time but most notably, larval survival. Therefore, thermal evolution of adult body size might not be independent of simultaneous adaptation of larval traits to resource availability. Using experimental evolution lines adapted to high and low temperatures at different levels of food, we show that selection pressures interact in shaping larval resource processing. Evolution on poor food invariably leads to lower resource acquisition suggesting a cost to feeding behavior. However, following low temperature selection, lower resource acquisition led to a higher adult body size, probably by more efficient allocation to growth. In contrast, following high temperature selection, low resource acquisition benefited larval survival, possibly by reducing feeding-associated costs. We show that evolved differences to larval resource processing provide a possible proximate mechanism to variation in a suite of correlated life-history traits during adaptation to different climates. The implication for natural populations is that in nature, thermal evolution drives populations to opposite ends of an adult size versus larval survival trade-off by altering resource processing, if resource availability is limited.

Multiple Weather Factors Affect Apparent Survival of European Passerine Birds

PubMed Central

Salewski, Volker; Hochachka, Wesley M.; Fiedler, Wolfgang

2013-01-01

Weather affects the demography of animals and thus climate change will cause local changes in demographic rates. In birds numerous studies have correlated demographic factors with weather but few of those examined variation in the impacts of weather in different seasons and, in the case of migrants, in different regions. Using capture-recapture models we correlated weather with apparent survival of seven passerine bird species with different migration strategies to assess the importance of selected facets of weather throughout the year on apparent survival. Contrary to our expectations weather experienced during the breeding season did not affect apparent survival of the target species. However, measures for winter severity were associated with apparent survival of a resident species, two short-distance/partial migrants and a long-distance migrant. Apparent survival of two short distance migrants as well as two long-distance migrants was further correlated with conditions experienced during the non-breeding season in Spain. Conditions in Africa had statistically significant but relatively minor effects on the apparent survival of the two long-distance migrants but also of a presumably short-distance migrant and a short-distance/partial migrant. In general several weather effects independently explained similar amounts of variation in apparent survival for the majority of species and single factors explained only relatively low amounts of temporal variation of apparent survival. Although the directions of the effects on apparent survival mostly met our expectations and there are clear predictions for effects of future climate we caution against simple extrapolations of present conditions to predict future population dynamics. Not only did weather explains limited amounts of variation in apparent survival, but future demographics will likely be affected by changing interspecific interactions, opposing effects of weather in different seasons, and the potential for phenotypic and microevolutionary adaptations. PMID:23593131

Juvenile survival in a tropical population of roseate terns: Interannual variation and effect of tick parasitism

USGS Publications Warehouse

Monticelli, David; Ramos, Jaime A.; Hines, James E.; Nichols, James D.; Spendelow, Jeffrey A.

2008-01-01

Many demographic studies on long-lived seabirds have focused on the estimation of adult survival, but much less is known about survival during the early years of life, especially in tropical species. We report analyses of a capture–recapture dataset of 685 roseate terns ringed as fledglings and adults between 1998 and 2005 on Aride Island, Seychelles, and recaptured/resighted at the same colony site over a 5 yr (2002 to 2006) period. A multistate model was used to estimate survival for different age classes, including juvenile (first-year) birds returning as non-breeding prospectors. The effect of infestation by parasites (ticks) on survival was also examined. Overall, the estimated return of first-year individuals to the natal colony was very variable, ranging from 2 to 22%. Conditioned on survival, the probability of returning from Age 2 yr onwards increased to 70%. Survival rates were best modeled as time-specific, with estimates varying from 0.02 to 1.00 (mean 0.69) in first-year birds with a marked negative effect of tick infestation. In older birds (minimum age of 2 yr), the annual estimates fell between 0.69 and 0.86 (mean 0.77). Using a components of variance approach for estimation of year-to-year variation, we found high temporal variability for first-year individuals (coefficient of variation [CV] = 65%) compared to much less variation in the survival rate of older birds (CV = 9%). These findings agree with the life-history prediction that demographic rates of juveniles are usually lower and more variable than those of older individuals. Our results are also consistent with the predicted negative effect of tick parasitism on juvenile survival. Compared with data from other roseate tern populations, survival over the first 2 yr (Age 0 to 2 yr) was 18 to 40% higher in this study, suggesting that a high ‘young’ survival rate may be an important demographic trait in this tropical population to compensate for the low annual reproductive success. Our data show that estimating survival of young individuals may be crucial to elucidating the demographic tactics of seabirds.

Nest survival relative to patch size in a highly fragmented shortgrass prairie landscape

USGS Publications Warehouse

Skagen, S.K.; Yackel Adams, A.A.; Adams, R.D.

2005-01-01

Understanding the influences of habitat fragmentation on vertebrate populations is essential for the protection and ecological restoration of strategic sites for native species. We examined the effects of prairie fragmentation on avian reproductive success using artificial and natural nests on 26 randomly selected, privately owned patches of shortgrass prairie ranging in size from 7 to 454 ha within a cropland matrix in Washington County, Colorado, summer 2000. Survival trends of artificial and natural nests differed. Daily survival of artificial nests increased with patch size up to about 65 ha and differed little at larger patch sizes, whereas daily survival of Lark Bunting (Calamospiza melanocorys) and Horned Lark (Eremophila alpestris) nests decreased with increasing size of the grassland patch. We hypothesize that our unexpected findings of lower survival of natural nests with increasing patch sizes and different trends between artificial and natural nests are due to the particular structure of predator communities in our study area and the ways in which individual predators respond to artificial and natural nests. We recommend that the value of small habitat patches in highly fragmented landscapes not be overlooked.

Genetic differences in growth, migration, and survival between hatchery and wild steelhead and Chinook salmon: Introduction and executive summary

USGS Publications Warehouse

Rubin, Steve P.; Reisenbichler, Reginald; Wetzel, Lisa A.; Hayes, Michael C.

2012-01-01

This report presents results of studies testing for genetically based differences in performance (growth, migration, and survival) between hatchery and wild populations of steelhead and Chinook salmon (Project Number 90-052). The report is organized into 10 chapters with a general study introduction preceding the first chapter. A growing body of data shows that domestication and a resulting loss of fitness for natural rearing occur in hatchery populations of anadromous salmonids; however, the magnitude of domestication will vary among species and hatchery programs. Better information on domestication is needed to accurately predict the consequences when hatchery and wild fish interbreed. The intent of hatchery supplementation is to increase natural production through introduction of hatchery fish into natural production areas. The goal of this study was to provide managers with information on the genetic risks of hatchery supplementation to wild populations of Columbia River Basin summer steelhead and spring Chinook salmon.

Inferences about ungulate population dynamics derived from age ratios

USGS Publications Warehouse

Harris, N.C.; Kauffman, M.J.; Mills, L.S.

2008-01-01

Age ratios (e.g., calf:cow for elk and fawn:doe for deer) are used regularly to monitor ungulate populations. However, it remains unclear what inferences are appropriate from this index because multiple vital rate changes can influence the observed ratio. We used modeling based on elk (Cervus elaphus) life-history to evaluate both how age ratios are influenced by stage-specific fecundity and survival and how well age ratios track population dynamics. Although all vital rates have the potential to influence calf:adult female ratios (i.e., calf:xow ratios), calf survival explained the vast majority of variation in calf:adult female ratios due to its temporal variation compared to other vital rates. Calf:adult female ratios were positively correlated with population growth rate (??) and often successfully indicated population trajectories. However, calf:adult female ratios performed poorly at detecting imposed declines in calf survival, suggesting that only the most severe declines would be rapidly detected. Our analyses clarify that managers can use accurate, unbiased age ratios to monitor arguably the most important components contributing to sustainable ungulate populations, survival rate of young and ??. However, age ratios are not useful for detecting gradual declines in survival of young or making inferences about fecundity or adult survival in ungulate populations. Therefore, age ratios coupled with independent estimates of population growth or population size are necessary to monitor ungulate population demography and dynamics closely through time.

ypTNM staging after neoadjuvant chemotherapy in the Chinese gastric cancer population: an evaluation on the prognostic value of the AJCC eighth edition cancer staging system.

PubMed

Li, Ziyu; Wang, Yinkui; Shan, Fei; Ying, Xiangji; Wu, Zhouqiao; Xue, Kan; Miao, Rulin; Zhang, Yan; Ji, Jiafu

2018-05-10

This study aims to evaluate the new ypTNM staging system in Chinese gastric cancer patients. We conducted retrospective survival and regression analyses using a database of gastric cancer patients who underwent neoadjuvant chemotherapy at the Peking University Cancer Hospital and Institute from January 2007 to January 2015. A total of 473 patients were included in the study with 28 pathological complete response (pCR) cases, 3 ypT0N1 cases, 65 stage I cases, 126 stage II cases, and 251 stage III cases. The pCR cases had similar survival to stage I patients (p > 0.05). The 3-year disease-free survival (DFS) and 5-year overall survival (OS) rates of stage I, II and III patients were significantly different (3-year DFS: 89.0, 75.5, and 39.6%, p < 0.001; 5-year OS: 89.6, 65.5, and 36.5%, p = 0.001). Both ypT and ypN are independent predictors of patient survival, while further log-rank tests showed that the ypN stage is of better prognostic value than ypT. Subgrouping analysis revealed that stage III patients of ypT4b and ypN3 had worse survival compared to the rest of stage III cases (p < 0.001). The c-index values of the ypTNM stage and modified ypTNM stage (stage III divided into IIIa and IIIb) were 0.657 and 0.708, respectively (p < 0.001). Our data showed significant differences in survival among gastric cancer patients at different ypTNM stages, indicating its prognostic value in the Chinese population. Further detailed analyses may facilitate the subgrouping of each stage to allow for a more accurate evaluation of disease prognosis in gastric cancer patients.

How Life History Can Sway the Fixation Probability of Mutants

PubMed Central

Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

2016-01-01

In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

Evidence of local adaptation in westslope cutthroat trout

USGS Publications Warehouse

Drinan, Daniel P.; Zale, Alexander V.; Webb, Molly A.H.; Taper, Mark L.; Shepard, Bradley B.; Kalinowski, Steven T.

2012-01-01

An understanding of the process of local adaptation would allow managers to better protect and conserve species. Many salmonids are in need of such efforts, and because they often persist in differing, isolated environments, they are useful organisms for studying local adaptation. In addition, the temperature sensitivity of salmonids provides a likely target for natural selection. We studied thermal adaptation in four wild populations and one hatchery stock of westslope cutthroat trout Oncorhynchus clarkii lewisi . The mean summer temperatures of source streams ranged from 6.7°C to 11.2°C. Embryos were collected from the wild, and embryonic development, embryonic survival, and juvenile growth were determined. A significant relationship between median embryonic survival and source stream temperature was detected. Based on a rank test, populations from colder streams had a greater decline in median embryonic survival at warm temperatures than populations from warmer streams. Embryonic development and juvenile growth did not appear to be influenced by source. These findings suggest that populations are thermally adapted to their source streams and this should be considered by managers. However, further study is necessary to sort out the potential confounding factors, whether genetic or epigenetic.

Roles of survival and dispersal in reintroduction success of Griffon vulture (Gyps fulvus).

PubMed

Le Gouar, Pascaline; Robert, Alexandre; Choisy, Jean-Pierre; Henriquet, Sylvain; Lecuyer, Philippe; Tessier, Christian; Sarrazin, François

2008-06-01

The success of reintroduction programs greatly depends on the amount of mortality and dispersal of the released individuals. Although local environmental pressures are likely to play an important role in these processes, they have rarely been investigated because of the lack of spatial replicates of reintroduction. In the present study, we analyzed a 25-year data set encompassing 272 individuals released in five reintroduction programs of Griffon Vultures (Gyps fulvus) in France to examine the respective roles of survival and dispersal in program successes and failures. We use recent developments in multi-strata capture-recapture models to take into account tag loss in survival estimates and to consider and estimate dispersal among release areas. We also examined the effects of sex, age, time, area, and release status on survival, and we tested whether dispersal patterns among release areas were consistent with habitat selection theories. Results indicated that the survival of released adults was reduced during the first year after release, with no difference between sexes. Taking into account local observations only, we found that early survival rates varied across sites. However when we distinguished dispersal from mortality, early survival rates became equal across release sites. It thus appears that among reintroduction programs difference in failure and success was due to differential dispersal among release sites. We revealed asymmetrical patterns of dispersal due to conspecific attraction: dispersers selected the closest and the largest population. We showed that mortality can be homogeneous from one program to another while, on the contrary, dispersal is highly dependent on the matrix of established populations. Dispersal behavior is thus of major interest for metapopulation restoration and should be taken into account in planning reintroduction designs.

Survival of Salmonella on chamomile, peppermint, and green tea during storage and subsequent survival or growth following tea brewing.

PubMed

Keller, Susanne E; Stam, Christina N; Gradl, Dana R; Chen, Zhengzai; Larkin, Emily L; Pickens, Shannon R; Chirtel, Stuart J

2015-04-01

The survival of Salmonella on dried chamomile flowers, peppermint leaves, and green tea leaves stored under different conditions was examined. Survival and growth of Salmonella was also assessed after subsequent brewing using dried inoculated teas. A Salmonella enterica serovar cocktail was inoculated onto different dried tea leaves or flowers to give starting populations of approximately 10 log CFU/g. The inoculum was allowed to dry (at ambient temperature for 24 h) onto the dried leaves or flowers prior to storage under 25 and 35 °C at low (<30% relative humidity [RH]) and high (>90% RH) humidity levels. Under the four storage conditions tested, survival followed the order 25 °C with low RH > 35 °C with low RH > 25 °C with high RH > 35 °C with high RH. Salmonella losses at 25 °C with low RH occurred primarily during drying, after which populations showed little decline over 6 months. In contrast, Salmonella decreased below detection after 45 days at 35 °C and high RH in all teas tested. The thermal resistance of Salmonella was assessed at 55 °C immediately after inoculation of tea leaves or flowers, after drying (24 h) onto tea leaves or flowers, and after 28 days of storage at 25 °C with low RH. All conditions resulted in similar D-values (2.78 ± 0.12, 3.04 ± 0.07, and 2.78 ± 0.56, at 0 h, 24 h, and 28 days, respectively), indicating thermal resistance of Salmonella in brewed tea did not change after desiccation and 28 days of storage. In addition, all brewed teas tested supported the growth of Salmonella. If Salmonella survives after storage, it may also survive and grow after a home brewing process.

Childhood cancer incidence and survival in Japan and England: A population-based study (1993-2010).

PubMed

Nakata, Kayo; Ito, Yuri; Magadi, Winnie; Bonaventure, Audrey; Stiller, Charles A; Katanoda, Kota; Matsuda, Tomohiro; Miyashiro, Isao; Pritchard-Jones, Kathy; Rachet, Bernard

2018-02-01

The present study aimed to compare cancer incidence and trends in survival for children diagnosed in Japan and England, using population-based cancer registry data. The analysis was based on 5192 children with cancer (age 0-14 years) from 6 prefectural cancer registries in Japan and 21 295 children diagnosed in England during 1993-2010. Differences in incidence rates between the 2 countries were measured with Poisson regression models. Overall survival was estimated using the Kaplan-Meier method. Incidence rates for Hodgkin lymphoma, renal tumors and Ewing sarcomas in England were more than twice as high as those in Japan. Incidence of germ cell tumors, hepatic tumors, neuroblastoma and acute myeloid leukemia (AML) was higher in Japan than in England. Incidence of all cancers combined decreased in Japan throughout the period 1993 to 2010, which was mainly explained by a decrease in registration of neuroblastoma in infants. For many cancers, 5-year survival improved in both countries. The improvement in survival in chronic myeloid leukemia (CML) was particularly dramatic in both countries. However, 5-year survival remained less than 80% in 2005-2008 in both countries for AML, brain tumors, soft tissue sarcomas, malignant bone tumors and neuroblastoma (age 1-14 years). There were significant differences in incidence of several cancers between countries, suggesting variation in genetic susceptibility and possibly environmental factors. The decrease in incidence for all cancers combined in Japan was related to the cessation of the national screening program for neuroblastoma. The large improvement in survival in CML coincided with the introduction of effective therapy (imatinib). © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Public goods games in populations with fluctuating size.

PubMed

McAvoy, Alex; Fraiman, Nicolas; Hauert, Christoph; Wakeley, John; Nowak, Martin A

2018-05-01

Many mathematical frameworks of evolutionary game dynamics assume that the total population size is constant and that selection affects only the relative frequency of strategies. Here, we consider evolutionary game dynamics in an extended Wright-Fisher process with variable population size. In such a scenario, it is possible that the entire population becomes extinct. Survival of the population may depend on which strategy prevails in the game dynamics. Studying cooperative dilemmas, it is a natural feature of such a model that cooperators enable survival, while defectors drive extinction. Although defectors are favored for any mixed population, random drift could lead to their elimination and the resulting pure-cooperator population could survive. On the other hand, if the defectors remain, then the population will quickly go extinct because the frequency of cooperators steadily declines and defectors alone cannot survive. In a mutation-selection model, we find that (i) a steady supply of cooperators can enable long-term population survival, provided selection is sufficiently strong, and (ii) selection can increase the abundance of cooperators but reduce their relative frequency. Thus, evolutionary game dynamics in populations with variable size generate a multifaceted notion of what constitutes a trait's long-term success. Copyright © 2018 Elsevier Inc. All rights reserved.

Men and women show similar survival outcome in stage IV breast cancer.

PubMed

Wu, San-Gang; Zhang, Wen-Wen; Liao, Xu-Lin; Sun, Jia-Yuan; Li, Feng-Yan; Su, Jing-Jun; He, Zhen-Yu

2017-08-01

To evaluate the clinicopathological features, patterns of distant metastases, and survival outcome between stage IV male breast cancer (MBC) and female breast cancer (FBC). Patients diagnosed with stage IV MBC and FBC between 2010 and 2013 were included using the Surveillance, Epidemiology, and End Results program. Univariate and multivariate Cox regression analyses were used to analyze risk factors for overall survival (OS). A total of 4997 patients were identified, including 60 MBC and 4937 FBC. Compared with FBC, patients with MBC were associated with a significantly higher rate of estrogen receptor-positive, progesterone receptor-positive, unmarried, lung metastases, and a lower frequency of liver metastases. Univariate and multivariate analyses showed no significant difference in OS between MBC and FBC. In the propensity score-matched population, there was also no difference in survival between MBC and FBC. Multivariate analysis of MBC showed that OS was longer for patients aged 50-69 years and with estrogen receptor-positive disease. There was no significant difference in survival outcome between stage IV MBC and FBC, but significant differences in clinicopathological features and patterns of metastases between the genders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Does community deprivation determine longevity after the age of 75? A cross-national analysis.

PubMed

Ribeiro, Ana Isabel; Krainski, Elias Teixeira; Carvalho, Marilia Sá; Launoy, Guy; Pornet, Carole; de Pina, Maria de Fátima

2018-05-01

Analyze the association between socioeconomic deprivation and old-age survival in Europe, and investigate whether it varies by country and gender. Our study incorporated five countries (Portugal, Spain, France, Italy, and England). A 10-year survival rate expressing the proportion of population aged 75-84 years who reached 85-94 years old was calculated at area-level for 2001-11. To estimate associations, we used Bayesian spatial models and a transnational measure of deprivation. Attributable/prevention fractions were calculated. Overall, there was a significant association between deprivation and survival in both genders. In England that association was stronger, following a dose-response relation. Although lesser in magnitude, significant associations were observed in Spain and Italy, whereas in France and Portugal these were even weaker. The elimination of socioeconomic differences between areas would increase survival by 7.1%, and even a small reduction in socioeconomic differences would lead to a 1.6% increase. Socioeconomic deprivation was associated with survival among older adults at ecological-level, although with varying magnitude across countries. Reasons for such cross-country differences should be sought. Our results emphasize the importance of reducing socioeconomic differences between areas.

PARP-1 serves as a novel molecular marker for hepatocellular carcinoma in a Southern Chinese Zhuang population.

PubMed

Li, Jiatong; Dou, Dongwei; Li, Ping; Luo, Wenqi; Lv, Wenxin; Zhang, Chengdong; Song, Xiaowei; Yang, Yuan; Zhang, Yuening; Xu, Yanzhen; Xiao, Feifan; Wei, Yan; Qin, Jian; Li, Hongtao; Yang, Xiaoli

2017-07-01

PARP-1 (poly(ADP-ribose) polymerase-1) plays an important role in tumorigenesis. Since its effects on different populations are varied, this study investigated the impact of PARP-1 on primary hepatocellular carcinoma in a Southern Chinese Zhuang population. We assessed the global PARP-1 messenger RNA expression in patients with hepatocellular carcinoma using The Cancer Genome Atlas dataset. Increased PARP-1 expression, related to alpha-fetoprotein level, was observed. The area under the receiver operating characteristic curve value was 0.833. Kaplan-Meier survival curves indicated that higher PARP-1 expression was not correlated with poorer overall survival and recurrence-free survival. In a Zhuang population, PARP-1 messenger RNA and protein levels were increased in the hepatocellular carcinoma tissue and its adjacent liver tissues as assessed by quantitative polymerase chain reaction, immunohistochemistry, and western blotting. Higher PARP-1 level was associated with a higher tumor stage (p < 0.05), without correlation with age, gender, smoking, drinking, tumor size, serum alpha-fetoprotein level, hepatitis B virus infection, metastasis, and invasion (p > 0.05). Further analysis suggested that H2AX, a PARP-1 protein interaction partner, was coordinated with PARP-1 in hepatocellular carcinoma tumorigenesis. Overall, some new characteristics of PARP-1 expression were noted in the Zhuang population. PARP-1 is a novel promising diagnostic marker for hepatocellular carcinoma in the Southern Chinese Zhuang population.

Global cardiovascular mortality risk in the adult Polish population: prospective assessment of the cohorts studied in multicentre national WOBASZ and WOBASZ Senior studies.

PubMed

Piotrowski, Walerian; Waśkiewicz, Anna; Cicha-Mikołajczyk, Alicja

2016-01-01

To develop a global cardiovascular disease (CVD) mortality risk model for the Polish population and to verify these data in the context of the SCORE risk algorithm. We analysed data obtained in two multicentre national population studies, the WOBASZ study which was conducted in 2003-2005 and included 14,769 subjects aged 20-74 years, and the WOBASZ Senior study which was conducted in 2007 and included 1096 subjects above 74 years of age. All these subjects were followed for survival status until 2012 and the cause of death was determined. The mean duration of follow-up was 8.2 years for WOBASZ study participants and about 5 years for WOBASZ Senior study participants. Overall, 1436 subjects died, including 568 due to CVD. For the purpose of our analysis of overall and CVD mortality, 15 established risk factors were selected. Survival was analysed separately in WOBASZ and WOBASZ Senior study participants. Statistical methods included descriptive statistics, Kaplan-Meier curves, Cox proportional hazard models, and the SCORE risk algorithm. Measure of incompatibility of the SCORE risk model to the Polish population was determined as the difference between mortality rates by the SCORE risk quartiles and the Cox approach. During the 8-year follow-up of the WOBASZ study population, mortality due to CVD was 38% among men and 31% among women. The most common causes of CVD mortality were ischaemic heart disease (IHD, 33%) followed by cerebro-vascular disease (17%) in men, and cerebrovascular disease (31%) followed by IHD (23%) in women. We found significant differences between men and women in regard to survival curves for both overall mortality and CVD mortality (p < 0.0001). For overall mortality among men and women, nearly all selected risk factors were shown to be significant in univariate analyses, except for high density lipoprotein cholesterol (HDL-C) level and the total cholesterol/HDL-C ratio in men, and smoking status in women. In multivariate analysis, independent predictors in men included age, glucose level, systolic blood pressure, and smoking status. In women, independent predictors were age, smoking status, and diabetes. During the 5-year follow-up of the WOBASZ Senior study population, mortality due to CVD was 48% among men and 58% among women. The most common cause of CVD mortality in both men and women was IHD (29% and 24%, respectively), followed by cerebrovascular disease (16% and 21%, respectively). We found significant differences between men and women in regard to survival curves for overall mortality (p < 0.0001) but not for CVD mortality (p = 0.0755). Due to the fact that survival curves for CVD mortality did not differ between men and women, we estimated the cut-off age for no survival difference in the WOBASZ study. By selecting the oldest patients and adding them to the WOBASZ Senior cohort, we obtained the cut-off age of 70 years above which the survival curves were not significantly different between men and women. In univariate analyses, independent predictors in men were age and creatinine level. These factors remained significant in multivariate analysis. In women above 74 years of age, independent predictors in univariate analyses included age, HDL-C level, creatinine level, total cholesterol/HDL-C ratio, and smoking status. Age, HDL-C level, creatinine level, and smoking status remained independent predictors of overall mortality in multivariate analysis. For CVD mortality, significant predictors were the same as for overall mortality. In women, significant predictors in uni- and multivariate analyses were age and smoking status. Overall disagreement between CVD mortality rates by the SCORE risk model and the Cox model was 5.7% in men and 2% in women. 1. Long-term follow-up of WOBASZ and WOBASZ Senior study participants allowed assessment of the inde-pendent association of the evaluated cardiovascular risk factors with CVD mortality in the Polish population. 2. Validation of the SCORE risk algorithm to estimate individual global CVD risk in the Polish population showed a high predictive value of this algorithm.

The influence of urban, suburban, or rural locale on survival from refractory prehospital cardiac arrest.

PubMed

Vukmir, Rade B

2004-03-01

There are many variables that can have an effect on survival in cardiopulmonary arrest. This study examined the effect of urban, suburban, or rural location on the outcome of prehospital cardiac arrest as a secondary end point in a study evaluating the effect of bicarbonate on survival. The proportion of survivors within a type of EMS provider system as well as response times were compared. This prospective, randomized, double-blind clinical intervention trial enrolled 874 prehospital cardiopulmonary arrest patients encountered by prehospital urban, suburban, and rural regional EMS area. Population density (patients per square mile) calculation allowed classification into urban (>2000/mi2), suburban (>400/mi2), and rural (0-399/mi2) systems. This group underwent standard advanced cardiac life support (ACLS) intervention with or without early empiric administration of bicarbonate in a 1-mEq/kg dose. A group of demographic, diagnostic, and therapeutic variables were analyzed for their effect on survival. Times were measured from collapse until onset of medical intervention and survival measured as the presence of ED vital signs on arrival. Data analysis used chi-squared with Pearson correlation for survivorship and Student t test comparisons for response times. The overall survival rate was approximately 13.9% (110 of 793), ranging from 9% rural, 14% for suburban, and 23% for urban sites for 372 patients (P=.007). Survival differences were associated with classification of arrest locale in this sample-best for urban, suburban, followed by rural sites. There was no difference in time to bystander cardiopulmonary resuscitation, but medical response time (basic life support) was decreased for suburban or urban sites, and intervention (ACLS) and transport times were decreased for suburban sites alone. Although response times were differentiated by location, they were not necessarily predictive of survival. Factors other than response time such as patient population or resuscitation skill could influence survival from cardiac arrest occurring in diverse prehospital service areas.

Population dynamics of Greater Scaup breeding on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Flint, Paul L.; Grand, J. Barry; Fondell, Thomas F.; Morse, Julie A.

2006-01-01

Using a stochastic model, we estimated that, on average, breeding females produced 0.57 young females/nesting season. We combined this estimate of productivity with our annual estimates of adult survival and an assumed population growth rate of 1.0, then solved for an estimate of first-year survival (0.40). Under these conditions the predicted stable age distribution of breeding females (i.e., the nesting population) was 15.1% 1-year-old, 4.1% 2-year-old first-time breeders, and 80.8% 2-year-old and older, experienced breeders. We subjected this stochastic model to perturbation analyses to examine the relative effects of demographic parameters on k. The relative effects of productivity and adult survival on the population growth rate were 0.26 and 0.72, respectively. Thus, compared to productivity, proportionally equivalent changes in annual survival would have 2.8 times the effect on k. However, when we examined annual variation in predicted population size using standardized regression coefficients, productivity explained twice as much variation as annual survival. Thus, management actions focused on changes in survival or productivity have the ability to influence population size; however, substantially larger changes in productivity are required to influence population trends.

The Impact of Race on Survival After Hepatocellular Carcinoma in a Diverse American Population.

PubMed

Jones, Patricia D; Diaz, Carlos; Wang, Danlu; Gonzalez-Diaz, Joselin; Martin, Paul; Kobetz, Erin

2018-02-01

Hepatocellular carcinoma (HCC) incidence is increasing at differential rates depending on race. We aimed to identify associations between race and survival after HCC diagnosis in a diverse American population. Using the cancer registry from Sylvester Comprehensive Cancer Center, University of Miami and Jackson Memorial Hospitals, we performed retrospective analysis of 999 patients diagnosed with HCC between 9/24/2004 and 12/19/2014. We identified clinical characteristics by reviewing available electronic medical records. The association between race and survival was analyzed using Cox proportional hazards regression. Median survival in days was 425 in Blacks, 904.5 in non-Hispanic Whites, 652 in Hispanics, 570 in Asians, and 928 in others, p < 0.01. Blacks and Asians presented at more advanced stages with larger tumors. Although Whites had increased severity of liver disease at diagnosis compared to other races, they had 36% reduced rate of death compared to Blacks, [hazard ratio (HR) 0.64, 95% confidence interval (CI) 0.51-0.8, p < 0.01]. After adjusting for significant covariates, Whites had 22% (HR 0.78, 95% CI 0.61-0.99, p 0.04) reduced risk of death, compared to Blacks. Transplant significantly reduced rate of death; however, only 13.3% of Blacks had liver transplant, compared to 40.1% of Whites, p < 0.01. In this diverse sample of patients, survival among Blacks is the shortest after HCC diagnosis. Survival differences reflect a more advanced tumor stage at presentation rather than severity of underlying liver disease precluding treatment. Improving survival in minority populations, in whom HCC incidence is rapidly increasing, requires identification and modification of factors contributing to late-stage presentation.

Disparities in survival improvement for metastatic colorectal cancer by race/ethnicity and age in the United States.

PubMed

Sineshaw, Helmneh M; Robbins, Anthony S; Jemal, Ahmedin

2014-04-01

Previous studies documented significant increase in overall survival for metastatic colorectal cancer (CRC) since the late 1990s coinciding with the introduction and dissemination of new treatments. We examined whether this survival increase differed across major racial/ethnic populations and age groups. We identified patients diagnosed with primary metastatic colorectal cancer during 1992-2009 from 13 population-based cancer registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results Program, which cover about 14 % of the US population. The 5-year cause-specific survival rates were calculated using SEER*Stat software. From 1992-1997 to 2004-2009, 5-year cause-specific survival rates increased significantly from 9.8 % (95 % CI 9.2-10.4) to 15.7 % (95 % CI 14.7-16.6) in non-Hispanic whites and from 11.4 % (95 % CI 9.4-13.6) to 17.7 % (95 % CI 15.1-20.5) in non-Hispanic Asians, but not in non-Hispanic blacks [from 8.6 % (95 % CI 7.2-10.1) to 9.8 % (95 % CI 8.1-11.8)] or Hispanics [from 14.0 % (95 % CI 11.8-16.3) to 16.4 % (95 % CI 14.0-19.0)]. By age group, survival rates increased significantly for the 20-64-year age group and 65 years or older age group in non-Hispanic whites, although the improvement in the older non-Hispanic whites was substantially smaller. Rates also increased in non-Hispanic Asians for the 20-64-year age group although marginally nonsignificant. In contrast, survival rates did not show significant increases in both younger and older age groups in non-Hispanic blacks and Hispanics. Non-Hispanic blacks, Hispanics, and older patients diagnosed with metastatic CRC have not equally benefitted from the introduction and dissemination of new treatments.

Canada goose nest survival at rural wetlands in north-central Iowa

USGS Publications Warehouse

Ness, Brenna N.; Klaver, Robert W.

2016-01-01

The last comprehensive nest survival study of the breeding giant Canada goose (Branta canadensis maxima) population in Iowa, USA, was conducted >30 years ago during a period of population recovery, during which available nesting habitat consisted primarily of artificial nest structures. Currently, Iowa's resident goose population is stable and nests in a variety of habitats. We analyzed the effects of available habitat on nest survival and how nest survival rates compared with those of the expanding goose population studied previously to better understand how to maintain a sustainable Canada goose population in Iowa. We documented Canada goose nest survival at rural wetland sites in north-central Iowa. We monitored 121 nests in 2013 and 149 nests in 2014 at 5 Wildlife Management Areas (WMAs) with various nesting habitats, including islands, muskrat (Ondatra zibethicus) houses, and elevated nest structures. We estimated daily nest-survival rate using the nest survival model in Program MARK. Survival was influenced by year, site, stage, presence of a camera, nest age, and an interaction between nest age and stage. Nest success rates for the 28-day incubation period by site and year combination ranged from 0.10 to 0.84. Nest survival was greatest at sites with nest structures (β = 17.34). Nest survival was negatively affected by lowered water levels at Rice Lake WMA (2013 β = −0.77, nest age β = −0.07). Timing of water-level drawdowns for shallow lake restorations may influence nest survival rates.

Dynamics of a black-capped chickadee population, 1958-1983

USGS Publications Warehouse

Loery, G.; Nichols, J.D.

1985-01-01

The dynamics of a wintering population of Black-capped Chickadees (Parus atricapillus) were studied from 1958-1983 using capture-recapture methods. The Jolly-Seber model was used to obtain annual estimates of population size, survival rate, and recruitment. The average estimated population size over this period was ?160 birds. The average estimated number of new birds entering the population each year and alive at the time of sampling was ?57. The arithmetic mean annual survival rate estimate was ?0.59. We tested hypothesis about possible relationships between these population parameters and (1) the natural introduction of Tufted Titmice (Parus bicolor) to the area, (2) the clear-cutting of portions of nearby red pine (Pinus resinosa) plantations, and (3) natural variations in winter temperatures. The chickadee population exhibited a substantial short-term decline following titmouse establishment, produced by decreases in both survival rate and number of new recruits. Survival rate decline somewhat after the initiation of the pine clear-cutting, but population size was very similar before and after clear-cutting. Weighted least squares analyses provided no evidence of a relationship between survival rate and either of two winter temperature variables.

Breast cancer survival in New Zealand women.

PubMed

Campbell, Ian D; Scott, Nina; Seneviratne, Sanjeewa; Kollias, James; Walters, David; Taylor, Corey; Webster, Fleur; Zorbas, Helen; Roder, David M

2015-01-01

The Quality Audit (BQA) of Breast Surgeons of Australia and New Zealand includes a broad range of data and is the largest New Zealand (NZ) breast cancer (BC) database outside the NZ Cancer Registry. We used BQA data to compare BC survival by ethnicity, deprivation, remoteness, clinical characteristic and case load. BQA and death data were linked using the National Health Index. Disease-specific survival for invasive cases was benchmarked against Australian BQA data and NZ population-based survivals. Validity was explored by comparison with expected survival by risk factor. Compared with 93% for Australian audit cases, 5-year survival was 90% for NZ audit cases overall, 87% for Maori, 84% for Pacific and 91% for other. BC survival in NZ appears lower than in Australia, with inequities by ethnicity. Differences may be due to access, timeliness and quality of health services, patient risk profiles, BQA coverage and death-record methodology. © 2014 Royal Australasian College of Surgeons.

Demography of a reintroduced population: moving toward management models for an endangered species, the whooping crane

USGS Publications Warehouse

Servanty, Sabrina; Converse, Sarah J.; Bailey, Larissa L.

2014-01-01

The reintroduction of threatened and endangered species is now a common method for reestablishing populations. Typically, a fundamental objective of reintroduction is to establish a self-sustaining population. Estimation of demographic parameters in reintroduced populations is critical, as these estimates serve multiple purposes. First, they support evaluation of progress toward the fundamental objective via construction of population viability analyses (PVAs) to predict metrics such as probability of persistence. Second, PVAs can be expanded to support evaluation of management actions, via management modeling. Third, the estimates themselves can support evaluation of the demographic performance of the reintroduced population, e.g., via comparison with wild populations. For each of these purposes, thorough treatment of uncertainties in the estimates is critical. Recently developed statistical methods - namely, hierarchical Bayesian implementations of state-space models - allow for effective integration of different types of uncertainty in estimation. We undertook a demographic estimation effort for a reintroduced population of endangered whooping cranes with the purpose of ultimately developing a Bayesian PVA for determining progress toward establishing a self-sustaining population, and for evaluating potential management actions via a Bayesian PVA-based management model. We evaluated individual and temporal variation in demographic parameters based upon a multi-state mark-recapture model. We found that survival was relatively high across time and varied little by sex. There was some indication that survival varied by release method. Survival was similar to that observed in the wild population. Although overall reproduction in this reintroduced population is poor, birds formed social pairs when relatively young, and once a bird was in a social pair, it had a nearly 50% chance of nesting the following breeding season. Also, once a bird had nested, it had a high probability of nesting again. These results are encouraging considering that survival and reproduction have been major challenges in past reintroductions of this species. The demographic estimates developed will support construction of a management model designed to facilitate exploration of management actions of interest, and will provide critical guidance in future planning for this reintroduction. An approach similar to what we describe could be usefully applied to many reintroduced populations.

Salinity Tolerance of Early-Stage Oyster Larvae in the Choptank River, Chesapeake Bay, USA

NASA Astrophysics Data System (ADS)

Scharping, R. J.; North, E. W.; Plough, L. V.

2016-02-01

The eastern oyster (Crassostrea virginica) is ecologically and economically important to the Chesapeake Bay, Maryland, USA. Its population, however, is currently estimated to be less than one percent of what it was historically. To restore oyster populations, techniques such as larval transport modeling are being implemented to aid the selection of sanctuary locations. These models can incorporate biological factors such as salinity-induced mortality, but no data from low-salinity areas such as the oligohaline Choptank River, a major focus of oyster restoration in the Chesapeake, exist. The purpose of our study was to generate salinity-induced mortality data for oyster larvae from the Choptank River and compare their tolerances to those of oysters from different salinity regimes. We performed three experiments looking at the effect of salinities from 3 to 26 on the survival of larvae from 4 to 48 hrs post-fertilization. While overall survival differed across experiments, we found a consistent minimum survival threshold between 5-7 and peak survival window between 9-16. These salinity values were about 7 lower than those of oysters from the polyhaline Long Island Sound (threshold: 12.5-15; peak: 17.5-27). This research has direct application to oyster restoration in the Choptank River and similar low-salinity areas by improving larval transport model predictions.

Improving but Inferior Survival in Patients with Chronic Lymphocytic Leukemia in Taiwan: A Population-Based Study, 1990–2004

PubMed Central

Wu, Shang-Ju; Chiang, Chun-Ju; Lin, Chien-Ting; Tien, Hwei-Fang; Lai, Mei-Shu

2013-01-01

Background Chronic lymphocytic leukemia (CLL) is much less prevalent in Asian countries. Whether there are differences in survival outcomes between the East and West, however, remain unclear. Methods The survival data for CLL patients identified in the Taiwan Cancer Registry database between 1990 and 2004, together with corresponding data in the US Surveillance, Epidemiology, and End Results database, were retrieved. The relative survivals (RS, adjusted for the expected survival in the general population) were estimated in patients diagnosed in three 5-year periods of time. Results CLL drastically shortened patients’ life expectancy; more importantly, this negative impact in Taiwan was much larger than that in the US: the 5-year RS in Taiwan and US were 59% and 76%, and the 10-year RS, 45% and 56%, respectively. Nevertheless, survival in Taiwan was better in the periods after 1995 (5-year RS, from 53.0% to 60.6%), a time period corresponding to the introduction of the Taiwan National Health Insurance scheme. Such improvement was largely due to decreased mortality in patients younger than 65 (5-year RS, from 53.5% to 69.1%). Despite the improvement, patients’ RS in Taiwan in recent periods remain steadily 15∼20% inferior to that in the US in both younger and older patient groups. Conclusions The improved RS in Taiwan implies that therapeutic advances are changing the prognosis of CLL. The stable RS gap between Taiwanese and the US patients suggests the existence of an ethnic difference in CLL patients’ outcomes. PMID:23638168

Population genetics of the westernmost distribution of the glaciations-surviving black truffle Tuber melanosporum.

PubMed

García-Cunchillos, Iván; Sánchez, Sergio; Barriuso, Juan José; Pérez-Collazos, Ernesto

2014-04-01

The black truffle (Tuber melanosporum Vittad.) is an important natural resource due to its relevance as a delicacy in gastronomy. Different aspects of this hypogeous fungus species have been studied, including population genetics of French and Italian distribution ranges. Although those studies include some Spanish populations, this is the first time that the genetic diversity and genetic structure of the wide geographical range of the natural Spanish populations have been analysed. To achieve this goal, 23 natural populations were sampled across the Spanish geographical distribution. ISSR technique demonstrated its reliability and capability to detect high levels of polymorphism in the species. Studied populations showed high levels of genetic diversity (h N  = 0.393, h S  = 0.678, Hs = 0.418), indicating a non threatened genetic conservation status. These high levels may be a consequence of the wide distribution range of the species, of its spore dispersion by animals, and by its evolutionary history. AMOVA analysis showed a high degree of genetic structure among populations (47.89%) and other partitions as geographical ranges. Bayesian genetic structure analyses differentiated two main Spanish groups separated by the Iberian Mountain System, and showed the genetic uniqueness of some populations. Our results suggest the survival of some of these populations during the last glaciation, the Spanish southern distribution range perhaps surviving as had occurred in France and Italy, but it is also likely that specific northern areas may have acted as a refugia for the later dispersion to other calcareous areas in the Iberian Peninsula and probably France.

Using demography and movement behavior to predict range expansion of the southern sea otter.

USGS Publications Warehouse

Tinker, M.T.; Doak, D.F.; Estes, J.A.

2008-01-01

In addition to forecasting population growth, basic demographic data combined with movement data provide a means for predicting rates of range expansion. Quantitative models of range expansion have rarely been applied to large vertebrates, although such tools could be useful for restoration and management of many threatened but recovering populations. Using the southern sea otter (Enhydra lutris nereis) as a case study, we utilized integro-difference equations in combination with a stage-structured projection matrix that incorporated spatial variation in dispersal and demography to make forecasts of population recovery and range recolonization. In addition to these basic predictions, we emphasize how to make these modeling predictions useful in a management context through the inclusion of parameter uncertainty and sensitivity analysis. Our models resulted in hind-cast (1989–2003) predictions of net population growth and range expansion that closely matched observed patterns. We next made projections of future range expansion and population growth, incorporating uncertainty in all model parameters, and explored the sensitivity of model predictions to variation in spatially explicit survival and dispersal rates. The predicted rate of southward range expansion (median = 5.2 km/yr) was sensitive to both dispersal and survival rates; elasticity analysis indicated that changes in adult survival would have the greatest potential effect on the rate of range expansion, while perturbation analysis showed that variation in subadult dispersal contributed most to variance in model predictions. Variation in survival and dispersal of females at the south end of the range contributed most of the variance in predicted southward range expansion. Our approach provides guidance for the acquisition of further data and a means of forecasting the consequence of specific management actions. Similar methods could aid in the management of other recovering populations.

The Role of Wildfire, Prescribed Fire, and Mountain Pine Beetle Infestations on the Population Dynamics of Black-Backed Woodpeckers in the Black Hills, South Dakota

PubMed Central

Rota, Christopher T.; Millspaugh, Joshua J.; Rumble, Mark A.; Lehman, Chad P.; Kesler, Dylan C.

2014-01-01

Wildfire and mountain pine beetle infestations are naturally occurring disturbances in western North American forests. Black-backed woodpeckers (Picoides arcticus) are emblematic of the role these disturbances play in creating wildlife habitat, since they are strongly associated with recently-killed forests. However, management practices aimed at reducing the economic impact of natural disturbances can result in habitat loss for this species. Although black-backed woodpeckers occupy habitats created by wildfire, prescribed fire, and mountain pine beetle infestations, the relative value of these habitats remains unknown. We studied habitat-specific adult and juvenile survival probabilities and reproductive rates between April 2008 and August 2012 in the Black Hills, South Dakota. We estimated habitat-specific adult and juvenile survival probability with Bayesian multi-state models and habitat-specific reproductive success with Bayesian nest survival models. We calculated asymptotic population growth rates from estimated demographic rates with matrix projection models. Adult and juvenile survival and nest success were highest in habitat created by summer wildfire, intermediate in MPB infestations, and lowest in habitat created by fall prescribed fire. Mean posterior distributions of population growth rates indicated growing populations in habitat created by summer wildfire and declining populations in fall prescribed fire and mountain pine beetle infestations. Our finding that population growth rates were positive only in habitat created by summer wildfire underscores the need to maintain early post-wildfire habitat across the landscape. The lower growth rates in fall prescribed fire and MPB infestations may be attributed to differences in predator communities and food resources relative to summer wildfire. PMID:24736502

The influence of climatic variability on local population dynamics of Cercidium microphyllum (foothill paloverde)

USGS Publications Warehouse

Bowers, Janice E.; Turner, R.M.

2002-01-01

This study investigated correlations among climatic variability, population age structure, and seedling survival of a dominant Sonoran Desert tree, Cercidium microphyllum (foothill paloverde), at Tucson, Arizona, USA. A major goal was to determine whether wet years promote seedling establishment and thereby determine population structure. Plant age was estimated from basal circumference for a sample of 980 living and dead trees in twelve 0.5-ha plots. Ages ranged from 1 to 181 years. Age frequency distribution showed that the population is in decline. Most (51.2%) of the 814 living trees were 40-80 years old; only 6.5% were younger than 20 years. The average age of the 166 dead trees was 78 years. Fifty-nine percent of dead trees were aged 60-100 years. Survival of newly emerged seedlings was monitored for 7 years in a 557-m2 permanent plot. Mean survival in the 1st year of life was 1.7%. Only 2 of 1,008 seedlings lived longer than 1 year. Length of survival was not correlated with rainfall. Residual regeneration, an index of the difference between predicted and observed cohort size, showed that regeneration was high during the first half of the twentieth century and poor after the mid-1950s. Trends in regeneration did not reflect interannual variation in seasonal temperature or rain before 1950, that is, in the years before urban warming. Taken together, the seedling study and the regeneration analysis suggest that local population dynamics reflect biotic factors to such an extent that population age structure might not always be a reliable clue to past climatic influences.

The role of wildfire, prescribed fire, and mountain pine beetle infestations on the population dynamics of black-backed woodpeckers in the black hills, South Dakota.

PubMed

Rota, Christopher T; Millspaugh, Joshua J; Rumble, Mark A; Lehman, Chad P; Kesler, Dylan C

2014-01-01

Wildfire and mountain pine beetle infestations are naturally occurring disturbances in western North American forests. Black-backed woodpeckers (Picoides arcticus) are emblematic of the role these disturbances play in creating wildlife habitat, since they are strongly associated with recently-killed forests. However, management practices aimed at reducing the economic impact of natural disturbances can result in habitat loss for this species. Although black-backed woodpeckers occupy habitats created by wildfire, prescribed fire, and mountain pine beetle infestations, the relative value of these habitats remains unknown. We studied habitat-specific adult and juvenile survival probabilities and reproductive rates between April 2008 and August 2012 in the Black Hills, South Dakota. We estimated habitat-specific adult and juvenile survival probability with Bayesian multi-state models and habitat-specific reproductive success with Bayesian nest survival models. We calculated asymptotic population growth rates from estimated demographic rates with matrix projection models. Adult and juvenile survival and nest success were highest in habitat created by summer wildfire, intermediate in MPB infestations, and lowest in habitat created by fall prescribed fire. Mean posterior distributions of population growth rates indicated growing populations in habitat created by summer wildfire and declining populations in fall prescribed fire and mountain pine beetle infestations. Our finding that population growth rates were positive only in habitat created by summer wildfire underscores the need to maintain early post-wildfire habitat across the landscape. The lower growth rates in fall prescribed fire and MPB infestations may be attributed to differences in predator communities and food resources relative to summer wildfire.

Status and trends in demography of northern spotted owls, 1985-2003

USGS Publications Warehouse

Anthony, R.G.; Forsman, E.D.; Franklin, A.B.; Anderson, D.R.; Burnham, K.P.; White, Gary C.; Schwarz, C.J.; Nichols, J.D.; Hines, J.E.; Olson, G.S.; Ackers, S.H.; Andrews, L.S.; Biswell, B.L.; Carlson, P.C.; Diller, L.V.; Dugger, K.M.; Fehring, K.E.; Fleming, T.L.; Gerhardt, R.P.; Gremel, S.A.; Gutierrez, R.J.; Happe, P.J.; Herter, D.R.; Higley, J.M.; Horn, R.B.; Irwin, L.L.; Loschl, P.J.; Reid, J.A.; Sovern, S.G.; Krausman, P.R.

2006-01-01

We analyzed demographic data from northern spotted owls (Strix occidentalis caurina) from 14 study areas in Washington, Oregon, and California for 1985-2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14 study areas made up approximately 12% of the range of the subspecies and included federal, tribal, private, and mixed federal and private lands. The study areas also included all the major forest types that the subspecies inhabits. The analyses followed rigorous protocols that were developed a priori and were the result of extensive discussions and consensus among the authors. Our primary objectives were to estimate fecundity, apparent survival (??), and annual rate of population change (??) and to determine if there were any temporal trends in these population parameters. In addition to analyses of data from individual study areas, we conducted 2 meta-analyses on each demographic parameter. One meta-analysis was conducted on all 14 areas, and the other was restricted to the 8 areas that constituted the Effectiveness Monitoring Plan for northern spotted owls under the Northwest Forest Plan. The average number of years of reproductive data per study area was 14 (range = 5-19), and the average number of recapture occasions per study area was 13 (range = 4-18). Only 1 study area had 1 year old. We found no differences in apparent survival rates between sexes except for 1 area (Marin), which had only 6 years of data. Estimates of apparent survival from individual study areas indicated that there were differences among age classes with adults generally having higher survival than 1- and 2-year-olds. Apparent survival rates ranged from 0.750 (SE=0.026) to 0.886 (SE=0.010) for adults, 0.626 (SE=0.073) to 0.886 (SE=0.010) for 2-year-olds, and 0.415 (SE=0.111) to 0.860 (SE=0.017) for 1-year-olds. These estimates were comparable to survival rates from previous studies on the subspecies. We found evidence for negative time trends in survival rate

Longevity of outstanding sporting achievers: Mind versus muscle

PubMed Central

Smerdon, David C.; Clarke, Philip M.

2018-01-01

Background While there is strong evidence showing the survival advantage of elite athletes, much less is known about those engaged in mind sports such as chess. This study aimed to examine the overall as well as regional survival of International Chess Grandmasters (GMs) with a reference to the general population, and compare relative survival (RS) of GMs with that of Olympic medallists (OMs). Methods Information on 1,208 GMs and 15,157 OMs, respectively, from 28 countries were extracted from the publicly available data sources. The Kaplan-Meier method was used to estimate the survival rates of the GMs. A Cox proportional hazards model was used to adjust the survival for region, year at risk, age at risk and sex, and to estimate the life expectancy of the GMs. The RS rate was computed by matching each GM or OM by year at risk, age at risk and sex to the life table of the country the individual represented. Results The survival rates of GMs at 30 and 60 years since GM title achievement were 87% and 15%, respectively. The life expectancy of GMs at the age of 30 years (which is near the average age when they attained a GM title) was 53.6 ([95% CI]: 47.7–58.5) years, which is significantly greater than the overall weighted mean life expectancy of 45.9 years for the general population. Compared to Eastern Europe, GMs in North America (HR [95% CI]: 0.51 [0.29–0.88]) and Western Europe (HR [95% CI]: 0.53 [0.34–0.83]) had a longer lifespan. The RS analysis showed that both GMs and OMs had a significant survival advantage over the general population, and there was no statistically significant difference in the RS of GMs (RS [95% CI]: 1.14 [1.08–1.20]) compared to OMs: (RS [95% CI]: 1.09 [1.07–1.11]) at 30 years. Conclusion Elite chess players live longer than the general population and have a similar survival advantage to elite competitors in physical sports. PMID:29723296

Survival and recovery rates of mottled ducks banded in Texas and Louisiana

USGS Publications Warehouse

Haukos, David A.

2015-01-01

The Western Gulf Coast population of the mottled duck (Anas fulvigula) is dependent on the Gulf coastal marsh to complete its entire life cycle. Band recovery data can be used to monitor mottled duck populations by estimating annual survival, indexing harvest rate, and assessing movements. Band returns from hunting seasons 1997–2013 were used to evaluate factors influencing annual survival, recovery rates, and movements of mottled ducks in Texas and Louisiana. For banding years of 1997–2013, 58,349 normal, wild mottled ducks were banded and released in Texas and Louisiana. Since 2002, 86% of mottled duck bandings have occurred on the Chenier Plain of Texas and Louisiana. Hunters shot, recovered, and reported 7,061birds with bands during this period. Direct recovery rates were greater for juveniles than adults but changed little since the 1970s. Estimates of annual survival did not differ between Texas and Louisiana, but did among years and between sex and age classes. Adult male and juvenile female mottled ducks had the greatest and lowest annual survival rates, respectively. Recovery of birds banded on the Chenier Plain was four times greater for birds banded in Texas and harvested in Louisiana than banded in Louisiana and harvested in Texas. Much of the current inference of results from banding mottled ducks is limited to the Chenier Plain. To monitor the entire Western Gulf Coast population of mottled ducks, managers can consider expanding operational banding operations with annual quotas, which would improve survival and recovery estimates and allow for inference beyond the Chenier Plain region.

Early establishment response of different Pinus nigra ssp. salzmanii seed sources on contrasting environments: Implications for future reforestation programs and assisted population migration.

PubMed

Taïbi, K; del Campo, A D; Aguado, A; Mulet, J M

2016-04-15

Forest restoration constitutes an important issue within adaptive environmental management for climate change at global scale. However, effective implementation of these programs can only be achieved by revising current seed transfer guidelines, as they lack inherent spatial and temporal dynamics associated with climate change. In this sense, provenance trials may provide key information on the relative performance of different populations and/or genotypes under changing ecological conditions. This study addresses a methodological approach to evaluate early plantation performance and the consequent phenotypic plasticity and the pattern of the adaptation of different seed sources in contrasting environments. To this end, six seed sources of Salzmann pine were tested at three contrasting trial sites testing a hypothetical assisted population migration. Adaptation at each site was assessed through Joint Regression and Additive Main effect and Multiplication Interaction (AMMI) models. Most of the observed variation was attributed to the environment (above 90% for all traits), even so genotype and genotype by environment interaction (GxE) were significant. Seedlings out-planted under better site conditions did not differ in survival but in height growth. However, on sites with higher constraints, survival differed among seed sources and diameter growth was high. The adaptation analyses (AMMI) indicated that the cold-continental seed source 'Soria' performed as a generalist seed source, whereas 'Cordilleras Béticas', the southernmost seed source, was more adapted to harsh environments (frost and drought) in terms of survival. The results supported partially the hypothesis that assisted migration of seed sources makes sense within limited transfer distances, and this was reinforced by the GxE results. The present study could be valuable to address adaptive transfer of seedings in ecological restoration and to determine the suitable seed sources for reforestation programs and assisted population migration under climatic changes. The reported results are based on 3 years' data and need to be considered in this context. Copyright © 2016 Elsevier Ltd. All rights reserved.

Population dynamics of long-tailed ducks breeding on the Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Schamber, Jason L.; Flint, Paul L.; Grand, J. Barry; Wilson, Heather M.; Morse, Julie A.

2009-01-01

Population estimates for long-tailed ducks in North America have declined by nearly 50% over the past 30 years. Life history and population dynamics of this species are difficult to ascertain, because the birds nest at low densities across a broad range of habitat types. Between 1991 and 2004, we collected information on productivity and survival of long-tailed ducks at three locations on the Yukon-Kuskokwim Delta. Clutch size averaged 7.1 eggs, and nesting success averaged 30%. Duckling survival to 30 days old averaged 10% but was highly variable among years, ranging from 0% to 25%. Apparent annual survival of adult females based on mark-recapture of nesting females was estimated at 74%. We combined these estimates of survival and productivity into a matrix-based population model, which predicted an annual population decline of 19%. Elasticities indicated that population growth rate (λ) was most sensitive to changes in adult female survival. Further, the relatively high sensitivity of λ to duckling survival suggests that low duckling survival may be a bottleneck to productivity in some years. These data represent the first attempt to synthesize a population model for this species. Although our analyses were hampered by the small sample sizes inherent in studying a dispersed nesting species, our model provides a basis for management actions and can be enhanced as additional data become available.

Predicting Douglas-fir's response to a warming climate

Treesearch

Andrea Watts; Sheel Bansal; Connie Harrington; Brad St. Clair

2015-01-01

Douglas-fir is an iconic tree in the Pacific Northwest. Although individual trees may appear to be identical, genetic differences within each tree have resulted from adaptation to the local environment. These genetic differences over time have resulted in differences among populations that are important to the species' survival and growth in changing climates....

Overall Survival of Patients with Locally Advanced or Metastatic Esophageal Squamous Cell Carcinoma Treated with Nimotuzumab in the Real World.

PubMed

Saumell, Yaimarelis; Sanchez, Lizet; González, Sandra; Ortiz, Ramón; Medina, Edadny; Galán, Yaima; Lage, Agustin

2017-12-01

Despite improvements in surgical techniques and treatments introduced into clinical practice, the overall survival of patients with esophageal squamous cell carcinoma remains low. Several epidermal growth factor receptor inhibitors are being evaluated in the context of clinical trials, but there is little evidence of effectiveness in real-world conditions. This study aimed at assessing the effectiveness of nimotuzumab combined with onco-specific treatment in Cuban real-life patients with locally advanced or metastatic esophageal squamous cell carcinoma. A comparative and retrospective effectiveness study was performed. The 93 patients treated with nimotuzumab were matched, with use of propensity score matching, with patients who received a diagnosis of locally advanced or metastatic squamous cell carcinoma of the esophagus in three Cuban provinces reported between 2011 and 2015 to the National Cancer Registry. The Kaplan-Meier method was used to estimate event-time distributions. Log-rank statistics were used for comparisons of overall survival between groups. A two-component mixture model assuming a Weibull distribution was fitted to assess the effect of nimotuzumab on short-term and long-term survival populations. There was an increase in median overall survival in patients treated with nimotuzumab (11.9 months versus 6.5 months without treatment) and an increase in the 1-year survival rate (54.0% versus 21.9% without treatment). The 2-year survival rates were 21.1% for patients treated with nimotuzumab and 0% in the untreated cohort. There were statistically significant differences in survival between groups treated and not treated with nimotuzumab, both in the short-term survival population (6.0 months vs 4.0 months, p = 0.009) and in the long-term survival population (18.0 months vs 11.0 months, p = 0.001). Our study shows that nimotuzumab treatment concurrent with chemoradiotherapy increases the survival of real-world patients with locally advanced or metastatic esophageal squamous cell carcinoma. Further prospective studies are required to confirm the therapeutic effectiveness of nimotuzumab in esophageal cancer.

Demography and movement in a relocated population of Oregon Spotted Frogs (Rana pretiosa): Influence of season and gender

USGS Publications Warehouse

Chelgren, N.D.; Pearl, C.A.; Adams, M.J.; Bowerman, J.

2008-01-01

We used five years of recapture data and Bayesian estimation to assess seasonal survival, movement, and growth of Oregon Spotted Frogs (Rana pretiosa) relocated into created ponds at Dilman Meadow in Oregon, USA. We evaluate hypotheses specific to the relocation and elucidate aspects of R. pretiosa life history that are poorly known. The odds of survival of relocated individuals during the first year following relocation were 0.36 times the survival odds of relocated and non-relocated frogs after one year since the relocation. Survival rate was higher for large frogs. After accounting for frog size, we found little variation in survival between ponds at Dilman Meadow. Survival was lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. The highest survival rates occurred during winter for both genders, and one small spring was used heavily during winter but was used rarely during the rest of the year. Individual growth was higher in ponds that were not used for breeding, and increased with increasing pond age. Our study supports other evidence that R. pretiosa use different habitats seasonally and are specific in their overwintering habitat requirements. Because frogs were concentrated during winter, predator-free overwintering springs are likely to be of particular value for R. pretiosa populations. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

Higher frequency of genetic variants conferring increased risk for ADRs for commonly used drugs treating cancer, AIDS and tuberculosis in persons of African descent.

PubMed

Aminkeng, F; Ross, C J D; Rassekh, S R; Brunham, L R; Sistonen, J; Dube, M-P; Ibrahim, M; Nyambo, T B; Omar, S A; Froment, A; Bodo, J-M; Tishkoff, S; Carleton, B C; Hayden, M R

2014-04-01

There is established clinical evidence for differences in drug response, cure rates and survival outcomes between different ethnic populations, but the causes are poorly understood. Differences in frequencies of functional genetic variants in key drug response and metabolism genes may significantly influence drug response differences in different populations. To assess this, we genotyped 1330 individuals of African (n=372) and European (n=958) descent for 4535 single-nucleotide polymorphisms in 350 key drug absorption, distribution, metabolism, elimination and toxicity genes. Important and remarkable differences in the distribution of genetic variants were observed between Africans and Europeans and among the African populations. These could translate into significant differences in drug efficacy and safety profiles, and also in the required dose to achieve the desired therapeutic effect in different populations. Our data points to the need for population-specific genetic variation in personalizing medicine and care.

Higher frequency of genetic variants conferring increased risk for ADRs for commonly used drugs treating cancer, AIDS and tuberculosis in persons of African descent

PubMed Central

Aminkeng, F; Ross, CJD; Rassekh, SR; Brunham, LR; Sistonen, J; Dube, M-P; Ibrahim, M; Nyambo, TB; Omar, SA; Froment, A; Bodo, J-M; Tishkoff, S; Carleton, BC; Hayden, MR

2015-01-01

There is established clinical evidence for differences in drug response, cure rates and survival outcomes between different ethnic populations, but the causes are poorly understood. Differences in frequencies of functional genetic variants in key drug response and metabolism genes may significantly influence drug response differences in different populations. To assess this, we genotyped 1330 individuals of African (n = 372) and European (n = 958) descent for 4535 single-nucleotide polymorphisms in 350 key drug absorption, distribution, metabolism, elimination and toxicity genes. Important and remarkable differences in the distribution of genetic variants were observed between Africans and Europeans and among the African populations. These could translate into significant differences in drug efficacy and safety profiles, and also in the required dose to achieve the desired therapeutic effect in different populations. Our data points to the need for population-specific genetic variation in personalizing medicine and care. PMID:23588107

Thinking Differently in Global Health in Oncology Using a Diagonal Approach: Harnessing Similarities, Improving Education, and Empowering an Alternative Oncology Workforce.

PubMed

Rodriguez, Natalia M; Brant, Jeannine M; Pendharkar, Dinesh; Arreola-Ornelas, Hector; Bhadelia, Afsan; de Lima Lopes, Gilberto; Knaul, Felicia M

2017-01-01

Cancer is a leading global cause of death, and diverse and minority populations suffer worse outcomes compared with white people from Western societies. Within the United States, African Americans and other blacks, Hispanics, Asians, and American Indians have lower cancer survival rates than whites. In the rest of the world, those from low- and middle-income countries have the greatest disparities, but even those from non-Western high-income countries such as Oman and the United Arab Emirates are diagnosed with cancer at later stages and suffer increased mortality. Although considerable differences exist among these populations, similarities and synergies are also apparent. Challenges can be very similar in reaching these populations effectively for cancer control to improve outcomes, and innovative strategies are needed to effectively make change. In this review, the authors discuss new approaches to the prevention and early detection of cancer as well as the implementation of programs in global oncology and put in evidence cultural similarities and challenges of different populations, highlighting strategies to improve cancer survival and quality care around the world through innovations in training and education, empowerment of an alternative workforce, and a diagonal approach to cancer care using case studies drawn from the authors' work and experience.

Survival and growth of American alligator (Alligator mississippiensis) hatchlings after artificial incubation and repatriation

USGS Publications Warehouse

Temsiripong, Y.; Woodward, A.R.; Ross, J.P.; Kubilis, P.S.; Percival, H.F.

2006-01-01

Hatchling American Alligators (Alligator mississippiensis) produced from artificially incubated wild eggs were returned to their natal areas (repatriated). We compared artificially incubated and repatriated hatchlings released within and outside the maternal alligator's home range with naturally incubated hatchlings captured and released within the maternal alligator's home range on Lake Apopka, Lake Griffin, and Orange Lake in Florida. We used probability of recapture and total length at approximately nine months after hatching as indices of survival and growth rates. Artificially incubated hatchlings released outside of the maternal alligator's home range had lower recapture probabilities than either naturally incubated hatchlings or artificially incubated hatchlings released near the original nest site. Recapture probabilities of other treatments did not differ significantly. Artificially incubated hatchlings were approximately 6% shorter than naturally incubated hatchlings at approximately nine months after hatching. We concluded that repatriation of hatchlings probably would not have long-term effects on populations because of the resiliency of alligator populations to alterations of early age-class survival and growth rates of the magnitude that we observed. Repatriation of hatchlings may be an economical alternative to repatriation of older juveniles for population restoration. However, the location of release may affect subsequent survival and growth. Copyright 2006 Society for the Study of Amphibians and Reptiles.

Demography of a forest elephant population

PubMed Central

Turkalo, Andrea K.; Wrege, Peter H.

2018-01-01

African forest elephants face severe threats from illegal killing for ivory and bushmeat and habitat conversion. Due to their cryptic nature and inaccessible range, little information on the biology of this species has been collected despite its iconic status. Compiling individual based monitoring data collected over 20 years from the Dzanga Bai population in Central African Republic, we summarize sex and age specific survivorship and female age specific fecundity for a cohort of 1625 individually identified elephants. Annual mortality (average = 3.5%) and natality (average = 5.3%) were lower and markedly less variable relative to rates reported for savanna elephant populations. New individuals consistently entered the study system, leading to a 2.5% average annual increase in the registered population. Calf sex ratios among known birth did not differ from parity. A weak seasonal signal in births was detected suggesting increased conceptions during the wet season. Inter-calf intervals and age of primiparity were longer relative to savanna elephant populations. Within the population, females between the ages of 25–39 demonstrated the shortest inter-calf intervals and highest fecundity, and previous calf sex had no influence on the interval. Calf survivorship was high (97%) the first two years after birth and did not differ by sex. Male and female survival began to differ by the age of 13 years, and males demonstrated significantly lower survival relative to females by the age of 20. It is suspected these differences are driven by human selection for ivory. Forest elephants were found to have one of the longest generation times recorded for any species at 31 years. These data provide fundamental understanding of forest elephant demography, providing baseline data for projecting population status and trends. PMID:29447207

The Role of Population Origin and Microenvironment in Seedling Emergence and Early Survival in Mediterranean Maritime Pine (Pinus pinaster Aiton)

PubMed Central

Vizcaíno-Palomar, Natalia; Revuelta-Eugercios, Bárbara; Zavala, Miguel A.; Alía, Ricardo; González-Martínez, Santiago C.

2014-01-01

Understanding tree recruitment is needed to forecast future forest distribution. Many studies have reported the relevant ecological factors that affect recruitment success in trees, but the potential for genetic-based differences in recruitment has often been neglected. In this study, we established a semi-natural reciprocal sowing experiment to test for local adaptation and microenvironment effects (evaluated here by canopy cover) in the emergence and early survival of maritime pine (Pinus pinaster Aiton), an emblematic Mediterranean forest tree. A novel application of molecular markers was also developed to test for family selection and, thus, for potential genetic change over generations. Overall, we did not find evidence to support local adaptation at the recruitment stage in our semi-natural experiment. Moreover, only weak family selection (if any) was found, suggesting that in stressful environments with low survival, stochastic processes and among-year climate variability may drive recruitment. Nevertheless, our study revealed that, at early stages of recruitment, microenvironments may favor the population with the best adapted life strategy, irrespectively of its (local or non-local) origin. We also found that emergence time is a key factor for seedling survival in stressful Mediterranean environments. Our study highlights the complexity of the factors influencing the early stages of establishment of maritime pine and provides insights into possible management actions aimed at environmental change impact mitigation. In particular, we found that the high stochasticity of the recruitment process in stressful environments and the differences in population-specific adaptive strategies may difficult assisted migration schemes. PMID:25286410

The role of population origin and microenvironment in seedling emergence and early survival in Mediterranean maritime pine (Pinus pinaster Aiton).

PubMed

Vizcaíno-Palomar, Natalia; Revuelta-Eugercios, Bárbara; Zavala, Miguel A; Alía, Ricardo; González-Martínez, Santiago C

2014-01-01

Understanding tree recruitment is needed to forecast future forest distribution. Many studies have reported the relevant ecological factors that affect recruitment success in trees, but the potential for genetic-based differences in recruitment has often been neglected. In this study, we established a semi-natural reciprocal sowing experiment to test for local adaptation and microenvironment effects (evaluated here by canopy cover) in the emergence and early survival of maritime pine (Pinus pinaster Aiton), an emblematic Mediterranean forest tree. A novel application of molecular markers was also developed to test for family selection and, thus, for potential genetic change over generations. Overall, we did not find evidence to support local adaptation at the recruitment stage in our semi-natural experiment. Moreover, only weak family selection (if any) was found, suggesting that in stressful environments with low survival, stochastic processes and among-year climate variability may drive recruitment. Nevertheless, our study revealed that, at early stages of recruitment, microenvironments may favor the population with the best adapted life strategy, irrespectively of its (local or non-local) origin. We also found that emergence time is a key factor for seedling survival in stressful Mediterranean environments. Our study highlights the complexity of the factors influencing the early stages of establishment of maritime pine and provides insights into possible management actions aimed at environmental change impact mitigation. In particular, we found that the high stochasticity of the recruitment process in stressful environments and the differences in population-specific adaptive strategies may difficult assisted migration schemes.

Racial Differences in the Overall Survival of Hairy Cell Leukemia in the United States: A Population-Based Analysis of the Surveillance, Epidemiology, and End Results Database.

PubMed

Giri, Smith; Shrestha, Rajesh; Pathak, Ranjan; Bhatt, Vijaya Raj

2015-08-01

Several studies have reported excellent long-term overall survival (OS) of patients with hairy cell leukemia (HCL) without racial disparity. Studies in other cancers have demonstrated worse mortality among African American (AA) individuals. We used the Surveillance, Epidemiology, and End Results 18 database to identify HCL patients diagnosed between 1978 and 2011. Kaplan-Meier curves were plotted to estimate OS. Univariate analysis using the life table method and multivariate Cox regression model were used to determine the independent effect of race on OS. The study population included 78% men and had a median age of 56 years. Race included 93% white, 3.5% Asian/Pacific Islander, and 3.5% AA. The 10-year OS was significantly less for AA as compared with white and Asian/Pacific Islander individuals (54% vs. 72% vs. 75%; P < .001). A Kaplan-Meier survival curve showed a significantly worse OS for AA versus other races (P < .001). In a multivariate analysis, AA race remained an independent predictor for a worse OS (hazard ratio 1.77; 95% confidence interval, 1.30-2.40; P < .001) after adjusting for age, sex, year of diagnosis, and marital status. In this population-based study, only half of AA patients but more than two-thirds of HCL patients from other racial groups were alive at 10 years. Such drastic racial differences in OS of HCL patients at the population level mandates further evaluation of the contributory biological, socioeconomic, health system, and other factors. Understanding and overcoming such racial disparities might close the racial differences in OS of this potentially curable disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Protein deprivation decreases male survival and the intensity of sexual antagonism in southern field crickets Gryllus bimaculatus.

PubMed

Han, C S; Dingemanse, N J

2017-04-01

Recent theory predicts that the magnitude of sexual antagonism should depend on how well populations are adapted to their environment. We tested this idea experimentally by comparing intersexual genetic correlations for adult survival in pedigreed populations of southern field crickets (Gryllus bimaculatus) raised on naturally balanced (free-choice) vs. imbalanced (protein-deprived) diets. We tested for (1) sex differences in nutritional intake and preference, (2) sex-specific effects of protein deprivation on survival and (3) diet dependence of the level of sexual antagonism. Adult males and females consumed a similar amount of protein, but protein deprivation decreased male survival but not female survival. Protein deprivation appeared to decrease the degree of sexual antagonism as intersexual genetic correlations were significantly lower than 1 only for the complementary free-choice diet group but close to 1 for the protein-deficient diet group. Our findings thereby implied that variation in nutritional environments can alter the magnitude of sexual antagonism. This research represents an important step towards understanding the relationship between sexual antagonism and adaptation in heterogeneous environments. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Wilms' tumor in New York State: epidemiology and survivorship.

PubMed

Griffel, M

1977-12-01

The outcomes during the period 1950--1972 were compared for Wilms' tumor patients in Erie County, New York (Buffalo and environs) and in a random selection of 23 counties having much smaller populations. For the Erie cohorts of 1967 to 1972 an 87 per cent 7-year survival rate was found as compared with a 50 per cent survival for the corresponding cohorts of the less populous couties. For the years 1960--1966 the 5-year survival rates were respectively 67 and 25 per cent and for the decade 1950--1959, 26 and 23 per cent. The principal conclusion is that within the last 15 years the Erie residents have fared better than residents of the smaller counties. The difference is attributed to the better treatment and care available at some of the hospitals in Buffalo. Data on incidence, age at diagnosis, male/female ratio, and laterality are presented.

Disparities in Adolescent and Young Adult Survival After Testicular Cancer Vary by Histologic Subtype: A Population-Based Study in California 1988–2010

PubMed Central

Mujahid, Mahasin; Srinivas, Sandy; Keegan, Theresa H.M.

2016-01-01

Purpose: Testicular cancer is the most common cancer among adolescent and young adult (AYA) men 15–39 years of age. This study aims to determine whether race/ethnicity and/or neighborhood socioeconomic status (SES) contribute independently to survival of AYAs with testicular cancer. Methods: Data on 14,249 eligible AYAs with testicular cancer diagnosed in California between 1988 and 2010 were obtained from the population-based California Cancer Registry. Multivariable Cox proportional hazards regression was used to examine overall and testicular cancer-specific survival and survival for the seminoma and nonseminoma histologic subtypes according to race/ethnicity, census-tract level neighborhood SES, and other patient and clinical characteristics. Results: Compared with White AYAs, Hispanic AYAs had worse overall and testicular cancer-specific survival (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.07–1.37) and Black AYAs had worse overall survival (HR, 1.41; 95% CI, 1.01–1.97), independent of neighborhood SES and other demographic and clinical factors. Racial/ethnic disparities in survival were more pronounced for nonseminoma than for seminoma. AYAs residing in middle and low SES neighborhoods experienced worse survival across both histologic subtypes independent of race/ethnicity and other factors, while improvements in survival over time were more pronounced for seminoma. Longer time to treatment was also associated with worse survival, particularly for AYAs with nonseminoma. Conclusion: Among AYAs, race/ethnicity, and neighborhood SES are independently associated with survival after testicular cancer. Variation in disparities by histologic type according to demographic factors, year of diagnosis, and time to treatment may reflect differences in prognosis and extent of treatment for the two histologies. PMID:26812451

Disparities in Adolescent and Young Adult Survival After Testicular Cancer Vary by Histologic Subtype: A Population-Based Study in California 1988-2010.

PubMed

DeRouen, Mindy C; Mujahid, Mahasin; Srinivas, Sandy; Keegan, Theresa H M

2016-03-01

Testicular cancer is the most common cancer among adolescent and young adult (AYA) men 15-39 years of age. This study aims to determine whether race/ethnicity and/or neighborhood socioeconomic status (SES) contribute independently to survival of AYAs with testicular cancer. Data on 14,249 eligible AYAs with testicular cancer diagnosed in California between 1988 and 2010 were obtained from the population-based California Cancer Registry. Multivariable Cox proportional hazards regression was used to examine overall and testicular cancer-specific survival and survival for the seminoma and nonseminoma histologic subtypes according to race/ethnicity, census-tract level neighborhood SES, and other patient and clinical characteristics. Compared with White AYAs, Hispanic AYAs had worse overall and testicular cancer-specific survival (hazard ratio [HR], 1.21; 95% confidence interval [CI], 1.07-1.37) and Black AYAs had worse overall survival (HR, 1.41; 95% CI, 1.01-1.97), independent of neighborhood SES and other demographic and clinical factors. Racial/ethnic disparities in survival were more pronounced for nonseminoma than for seminoma. AYAs residing in middle and low SES neighborhoods experienced worse survival across both histologic subtypes independent of race/ethnicity and other factors, while improvements in survival over time were more pronounced for seminoma. Longer time to treatment was also associated with worse survival, particularly for AYAs with nonseminoma. Among AYAs, race/ethnicity, and neighborhood SES are independently associated with survival after testicular cancer. Variation in disparities by histologic type according to demographic factors, year of diagnosis, and time to treatment may reflect differences in prognosis and extent of treatment for the two histologies.

Racial disparities in advanced stage colorectal cancer survival

PubMed Central

Wallace, Kristin; Hill, Elizabeth G.; Lewin, David N.; Williamson, Grace; Oppenheimer, Stephanie; Ford, Marvella E.; Wargovich, Michael J.; Berger, Franklin G.; Bolick, Susan W.; Thomas, Melanie B.; Alberg, Anthony J.

2013-01-01

Purpose African Americans (AA) have a higher incidence and lower survival from colorectal cancer (CRC) compared to European Americans (EA). In the present study, statewide, population-based data from South Carolina Central Cancer Registry (SCCCR) is used to investigate the relationship between race and age on advanced stage CRC survival. Methods The study population was comprised of 3865 advanced pathologically documented colon and rectal adenocarcinoma cases diagnosed between 01 January 1996 and 31 December 2006: 2673 (69%) EA and 1192 (31%) AA. Kaplan-Meier methods were used to generate median survival time and corresponding 95% confidence intervals (CI) by race, age, and gender. Factors associated with survival were evaluated by fitting Cox proportional hazards (CPH) regression models to generate Hazard Ratios (HR) and 95% CI. Results We observed a significant interaction between race and age on CRC survival (p = 0.04). Among younger patients (< 50 years), AA race was associated with a 1.34 (95% CI 1.06-1.71) higher risk of death compared to EA. Among older patients, we observed a modest increase risk of death among AA men compared to EA (HR 1.16 (95% CI 1.01-1.32) but no difference by race among women (HR 0.94 (95% CI 0.82-1.08)). Moreover, we observed that the disparity in survival has worsened over the past 15 years. Conclusions Future studies that integrate clinical, molecular, and treatment-related data are needed for advancing understanding of the racial disparity in CRC survival, especially for those < 50 years old. PMID:23296454

Stochastic variation in avian survival rates: Life-history predictions, population consequences, and the potential responses to human perturbations and climate change

USGS Publications Warehouse

Schmutz, Joel A.; Thomson, David L.; Cooch, Evan G.; Conroy, Michael J.

2009-01-01

Stochastic variation in survival rates is expected to decrease long-term population growth rates. This expectation influences both life-history theory and the conservation of species. From this expectation, Pfister (1998) developed the important life-history prediction that natural selection will have minimized variability in those elements of the annual life cycle (such as adult survival rate) with high sensitivity. This prediction has not been rigorously evaluated for bird populations, in part due to statistical difficulties related to variance estimation. I here overcome these difficulties, and in an analysis of 62 populations, I confirm her prediction by showing a negative relationship between the proportional sensitivity (elasticity) of adult survival and the proportional variance (CV) of adult survival. However, several species deviated significantly from this expectation, with more process variance in survival than predicted. For instance, projecting the magnitude of process variance in annual survival for American redstarts (Setophaga ruticilla) for 25 years resulted in a 44% decline in abundance without assuming any change in mean survival rate. For most of these species with high process variance, recent changes in harvest, habitats, or changes in climate patterns are the likely sources of environmental variability causing this variability in survival. Because of climate change, environmental variability is increasing on regional and global scales, which is expected to increase stochasticity in vital rates of species. Increased stochasticity in survival will depress population growth rates, and this result will magnify the conservation challenges we face.

From genome-wide to candidate gene: an investigation of variation at the major histocompatibility complex in common bottlenose dolphins exposed to harmful algal blooms.

PubMed

Cammen, Kristina M; Wilcox, Lynsey A; Rosel, Patricia E; Wells, Randall S; Read, Andrew J

2015-02-01

The role the major histocompatibility complex (MHC) plays in response to exposure to environmental toxins is relatively poorly understood, particularly in comparison to its well-described role in pathogen immunity. We investigated associations between MHC diversity and resistance to brevetoxins in common bottlenose dolphins (Tursiops truncatus). A previous genome-wide association study investigating an apparent difference in harmful algal bloom (HAB) resistance among dolphin populations in the Gulf of Mexico identified genetic variation associated with survival in close genomic proximity to multiple MHC class II loci. Here, we characterized genetic variation at DQA, DQB, DRA, and DRB loci in dolphins from central-west Florida and the Florida Panhandle, including dolphins that died during HABs and dolphins presumed to have survived HAB exposure. We found that DRB and DQB exhibited patterns of genetic differentiation among geographic regions that differed from neutral microsatellite loci. In addition, genetic differentiation at DRB across multiple pairwise comparisons of live and dead dolphins was greater than differentiation observed at neutral loci. Our findings at these MHC loci did not approach the strength of association with survival previously described for a nearby genetic variant. However, the results provide evidence that selective pressures at the MHC vary among dolphin populations that differ in the frequency of HAB exposure and that the overall composition of DRB variants differs between dolphin survivors and non-survivors of HABs. These results may suggest a potential role of MHC diversity in variable survival of bottlenose dolphins exposed to HABs.

Adult survival, apparent lamb survival, and body condition of desert bighorn sheep in relation to habitat and precipitation on the Kofa National Wildlife Refuge, Arizona

USGS Publications Warehouse

Overstreet, Matthew; Caldwell, Colleen A.; Cain, James W.

2014-01-01

The decline of desert bighorn sheep on the Kofa National Wildlife Refuge (KNWR) beginning in 2003 stimulated efforts to determine the factors limiting survival and recruitment. We 1) determined pregnancy rates, body fat, and estimated survival rates of adults and lambs; 2) investigated the relationship between precipitation, forage conditions, previous year’s reproductive success, and adult body condition; 3) assessed the relative influence of body condition of adult females, precipitation, and forage characteristics on apparent survival of lambs; and 4) determined the prevalence of disease. To assess the influence of potential limiting factors on female desert bighorn sheep on the KNWR, we modeled percent body fat of adult females as a function of previous year’s reproductive effort, age class, and forage conditions (i.e., seasonal NDVI and seasonal precipitation). In addition, we assessed the relative influence of the body condition of adult females, precipitation, and forage conditions (NDVI) on length of time a lamb was observed at heel.Adult female survival was high in both 2009 (0.90 [SE = 0.05]) and 2010 (0.96 [SE = 0.03]). Apparent lamb survival to 6 months of age was 0.23 (SE = 0.05) during 2009-2010 and 0.21 (SE = 0.05) during 2010-2011 lambing seasons. Mean body fat for adult females was 12.03% (SE = 0.479) in 2009-2010 and 11.11% (SE= 0.486) in 2010-2011 and was not significantly different between years. Pregnancy rate was 100% in 2009 and 97.5% in 2010.Models containing the previous year’s reproductive effort, spring NDVI and previous year’s reproductive effort and spring precipitation best approximated data on percent body fat in adult females in 2009-2010. In 2010-2011, the two highest-ranking models included the previous year’s reproductive effort and winter NDVI and previous year’s reproductive effort, and winter and spring NDVI. None of the models assessing the influence of maternal body fat, precipitation, or forage conditions were particularly useful for predicting apparent lamb survival.The high pregnancy rates and body fat levels in excess of 11% do not indicate that this population of desert bighorn was nutritionally stressed during our study and are thus likely not contributing to the low lamb survival estimates we observed. However, body condition data during the population decline is not available and whether this population was nutritionally limited during the initial population decline remains unknown.The prevalence of disease in the Kofa herd may be a limiting factor; however, due to a lack of disease monitoring during the population decline it is uncertain if disease contributed to the decline. Further research is needed to fully understand the complex interaction of disease in this population at the individual and population level and determine to what extent disease predisposes individuals to predation or other causes of mortality.

Managing white-tailed deer: eastern North America

USGS Publications Warehouse

Robinson, Kelly F.; Diefenbach, Duane R.; Fuller, Angela K.; Hurst, Jeremy E.; Rosenberry, Christopher S.

2014-01-01

Many studies have documented that coyotes (Canis latrans) are the greatest source of natural mortality for white-tailed deer (Odocoileus virginianus) neonates (<3 months old). With the range expansion of coyotes eastward in North America, many stakeholders are concerned that coyote predation may be affecting deer populations adversely. We hypothesized that declines in neonate survival, perhaps caused by increasing coyote predation, could be offset by adjusting or eliminating antlerless harvest allocations. We used a stochastic, age-based population simulation model to evaluate combinations of low neonate survival rates, severe winters, and low adult deer survival rates to determine the effectiveness of reduced antlerless harvest at stabilizing deer populations. We found that even in regions with high winter mortality, reduced antlerless harvest rates could stabilize deer populations with recruitment and survival rates reported in the literature. When neonate survival rates were low (25%) and yearling and adult female survival rates were reduced by 10%, elimination of antlerless harvests failed to stabilize populations. Our results suggest increased deer mortality from coyotes can be addressed through reduced hunting harvest of adult female deer in most circumstances throughout eastern North America. However, specific knowledge of adult female survival rates is important for making management decisions in areas where both neonate and adult survival may be affected by predation and other mortality factors.

Can managers compensate for coyote predation of white-tailed deer?

USGS Publications Warehouse

Robinson, Kelly F.; Diefenbach, Duane R.; Fuller, Angela K.; Hurst, Jeremy E.; Rosenberry, Christopher S.

2014-01-01

Many studies have documented that coyotes (Canis latrans) are the greatest source of natural mortality for white-tailed deer (Odocoileus virginianus) neonates (<3 months old). With the range expansion of coyotes eastward in North America, many stakeholders are concerned that coyote predation may be affecting deer populations adversely. We hypothesized that declines in neonate survival, perhaps caused by increasing coyote predation, could be offset by adjusting or eliminating antlerless harvest allocations. We used a stochastic, age-based population simulation model to evaluate combinations of low neonate survival rates, severe winters, and low adult deer survival rates to determine the effectiveness of reduced antlerless harvest at stabilizing deer populations. We found that even in regions with high winter mortality, reduced antlerless harvest rates could stabilize deer populations with recruitment and survival rates reported in the literature. When neonate survival rates were low (25%) and yearling and adult female survival rates were reduced by 10%, elimination of antlerless harvests failed to stabilize populations. Our results suggest increased deer mortality from coyotes can be addressed through reduced hunting harvest of adult female deer in most circumstances throughout eastern North America. However, specific knowledge of adult female survival rates is important for making management decisions in areas where both neonate and adult survival may be affected by predation and other mortality factors.

Density-Dependent Recycling Promotes the Long-Term Survival of Bacterial Populations during Periods of Starvation.

PubMed

Takano, Sotaro; Pawlowska, Bogna J; Gudelj, Ivana; Yomo, Tetsuya; Tsuru, Saburo

2017-02-07

The amount of natural resources in the Earth's environment is in flux, which can trigger catastrophic collapses of ecosystems. How populations survive under nutrient-poor conditions is a central question in ecology. Curiously, some bacteria persist for a long time in nutrient-poor environments. Although this survival may be accomplished through cell death and the recycling of dead cells, the importance of these processes and the mechanisms underlying the survival of the populations have not been quantitated. Here, we use microbial laboratory experiments and mathematical models to demonstrate that death and recycling are essential activities for the maintenance of cell survival. We also show that the behavior of the survivors is governed by population density feedback, wherein growth is limited not only by the available resources but also by the population density. The numerical simulations suggest that population density-dependent recycling could be an advantageous behavior under starvation conditions. How organisms survive after exhaustion of resources is a central question in ecology. Starving Escherichia coli constitute a model system to understand survival mechanisms during long-term starvation. Although death and the recycling of dead cells might play a key role in the maintenance of long-term survival, their mechanisms and importance have not been quantitated. Here, we verified the significance of social recycling of dead cells for long-term survival. We also show that the survivors restrained their recycling and did not use all available nutrients released from dead cells, which may be advantageous under starvation conditions. These results indicate that not only the utilization of dead cells but also restrained recycling coordinate the effective utilization of limited resources for long-term survival under starvation. Copyright © 2017 Takano et al.

The influence of agroforestry and other land-use types on the persistence of a Sumatran tiger (Panthera tigris sumatrae) population: an individual-based model approach.

PubMed

Imron, Muhammad Ali; Herzog, Sven; Berger, Uta

2011-08-01

The importance of preserving both protected areas and their surrounding landscapes as one of the major conservation strategies for tigers has received attention over recent decades. However, the mechanism of how land-use surrounding protected areas affects the dynamics of tiger populations is poorly understood. We developed Panthera Population Persistence (PPP)--an individual-based model--to investigate the potential mechanism of the Sumatran tiger population dynamics in a protected area and under different land-use scenarios surrounding the reserve. We tested three main landscape compositions (single, combined and real land-uses of Tesso-Nilo National Park and its surrounding area) on the probability of and time to extinction of the Sumatran tiger over 20 years in Central Sumatra. The model successfully explains the mechanisms behind the population response of tigers under different habitat landscape compositions. Feeding and mating behaviours of tigers are key factors, which determined population persistence in a heterogeneous landscape. All single land-use scenarios resulted in tiger extinction but had a different probability of extinction within 20 years. If tropical forest was combined with other land-use types, the probability of extinction was smaller. The presence of agroforesty and logging concessions adjacent to protected areas encouraged the survival of tiger populations. However, with the real land-use scenario of Tesso-Nilo National Park, tigers could not survive for more than 10 years. Promoting the practice of agroforestry systems surrounding the park is probably the most reasonable way to steer land-use surrounding the Tesso-Nilo National Park to support tiger conservation.

Exploring the Association between Macroeconomic Indicators and Dialysis Mortality

PubMed Central

Stel, Vianda S.; Caskey, Fergus J.; Stengel, Benedicte; Elliott, Robert F.; Covic, Adrian; Geue, Claudia; Cusumano, Ana; MacLeod, Alison M.; Jager, Kitty J.

2012-01-01

Summary Background and objectives Mortality on dialysis varies greatly worldwide, with patient-level factors explaining only a small part of this variation. The aim of this study was to examine the association of national-level macroeconomic indicators with the mortality of incident dialysis populations and explore potential explanations through renal service indicators, incidence of dialysis, and characteristics of the dialysis population. Design, setting, participants, & measurements Aggregated unadjusted survival probabilities were obtained from 22 renal registries worldwide for patients starting dialysis in 2003–2005. General population age and health, macroeconomic indices, and renal service organization data were collected from secondary sources and questionnaires. Linear modeling with log–log transformation of the outcome variable was applied to establish factors associated with survival on dialysis. Results Two-year survival on dialysis ranged from 62.3% in Iceland to 89.8% in Romania. A higher gross domestic product per capita (hazard ratio=1.02 per 1000 US dollar increase), a higher percentage of gross domestic product spent on healthcare (1.10 per percent increase), and a higher intrinsic mortality of the dialysis population (i.e., general population-derived mortality risk of the dialysis population in that country standardized for age and sex; hazard ratio=1.04 per death per 10,000 person years) were associated with a higher mortality of the dialysis population. The incidence of dialysis and renal service indicators were not associated with mortality on dialysis. Conclusions Macroeconomic factors and the intrinsic mortality of the dialysis population are associated with international differences in the mortality on dialysis. Renal service organizational factors and incidence of dialysis seem less important. PMID:22837275

Exploring the association between macroeconomic indicators and dialysis mortality.

PubMed

Kramer, Anneke; Stel, Vianda S; Caskey, Fergus J; Stengel, Benedicte; Elliott, Robert F; Covic, Adrian; Geue, Claudia; Cusumano, Ana; Macleod, Alison M; Jager, Kitty J

2012-10-01

Mortality on dialysis varies greatly worldwide, with patient-level factors explaining only a small part of this variation. The aim of this study was to examine the association of national-level macroeconomic indicators with the mortality of incident dialysis populations and explore potential explanations through renal service indicators, incidence of dialysis, and characteristics of the dialysis population. Aggregated unadjusted survival probabilities were obtained from 22 renal registries worldwide for patients starting dialysis in 2003-2005. General population age and health, macroeconomic indices, and renal service organization data were collected from secondary sources and questionnaires. Linear modeling with log-log transformation of the outcome variable was applied to establish factors associated with survival on dialysis. Two-year survival on dialysis ranged from 62.3% in Iceland to 89.8% in Romania. A higher gross domestic product per capita (hazard ratio=1.02 per 1000 US dollar increase), a higher percentage of gross domestic product spent on healthcare (1.10 per percent increase), and a higher intrinsic mortality of the dialysis population (i.e., general population-derived mortality risk of the dialysis population in that country standardized for age and sex; hazard ratio=1.04 per death per 10,000 person years) were associated with a higher mortality of the dialysis population. The incidence of dialysis and renal service indicators were not associated with mortality on dialysis. Macroeconomic factors and the intrinsic mortality of the dialysis population are associated with international differences in the mortality on dialysis. Renal service organizational factors and incidence of dialysis seem less important.

Long-term survival in women with borderline ovarian tumors: a population-based survey of borderline ovarian tumors in Sweden 1960-2007.

PubMed

Kalapotharakos, Grigorios; Högberg, Thomas; Bergfeldt, Kjell; Borgfeldt, Christer

2016-04-01

We conducted an evaluation of incidence and survival of women with borderline ovarian tumors in Sweden. All women diagnosed with borderline ovarian tumor in the Swedish Cancer Register 1960-2007 (n = 6252) combined with follow up in the Swedish Death Registry to 1 July 2009 were included. Estimation of age-standardized relative survival rate according to time periods for diagnosis. The incidence of borderline ovarian tumors increased during the study period, with a steep increase during the 1980s. The age standardized 5-year relative survival including all borderline tumors diagnosed 2000-07 was 97% (95% CI 92-99%). In women aged ≤64 years, the 10-year relative survival related to age at diagnosis of borderline tumors ranged from 95 to 98% and was 89% in women aged 65-74 years. In a multivariable analysis including age and decade of diagnosis relative survival for every decade increased. The 10-year relative survival in women with mucinous and serous borderline tumors did not differ significantly (p = 0.121). Results of the present study are reassuring about long-term survival in women with borderline ovarian tumors. The age-standardized relative survival rate increased across time periods for diagnosis. There was no difference in long-term survival between mucinous and serous borderline ovarian tumors. © 2016 Nordic Federation of Societies of Obstetrics and Gynecology.

Robust estimates of environmental effects on population vital rates: an integrated capture–recapture model of seasonal brook trout growth, survival and movement in a stream network

USGS Publications Warehouse

Letcher, Benjamin H.; Schueller, Paul; Bassar, Ronald D.; Nislow, Keith H.; Coombs, Jason A.; Sakrejda, Krzysztof; Morrissey, Michael; Sigourney, Douglas B.; Whiteley, Andrew R.; O'Donnell, Matthew J.; Dubreuil, Todd L.

2015-01-01

Modelling the effects of environmental change on populations is a key challenge for ecologists, particularly as the pace of change increases. Currently, modelling efforts are limited by difficulties in establishing robust relationships between environmental drivers and population responses.We developed an integrated capture–recapture state-space model to estimate the effects of two key environmental drivers (stream flow and temperature) on demographic rates (body growth, movement and survival) using a long-term (11 years), high-resolution (individually tagged, sampled seasonally) data set of brook trout (Salvelinus fontinalis) from four sites in a stream network. Our integrated model provides an effective context within which to estimate environmental driver effects because it takes full advantage of data by estimating (latent) state values for missing observations, because it propagates uncertainty among model components and because it accounts for the major demographic rates and interactions that contribute to annual survival.We found that stream flow and temperature had strong effects on brook trout demography. Some effects, such as reduction in survival associated with low stream flow and high temperature during the summer season, were consistent across sites and age classes, suggesting that they may serve as robust indicators of vulnerability to environmental change. Other survival effects varied across ages, sites and seasons, indicating that flow and temperature may not be the primary drivers of survival in those cases. Flow and temperature also affected body growth rates; these responses were consistent across sites but differed dramatically between age classes and seasons. Finally, we found that tributary and mainstem sites responded differently to variation in flow and temperature.Annual survival (combination of survival and body growth across seasons) was insensitive to body growth and was most sensitive to flow (positive) and temperature (negative) in the summer and fall.These observations, combined with our ability to estimate the occurrence, magnitude and direction of fish movement between these habitat types, indicated that heterogeneity in response may provide a mechanism providing potential resilience to environmental change. Given that the challenges we faced in our study are likely to be common to many intensive data sets, the integrated modelling approach could be generally applicable and useful.

Robust estimates of environmental effects on population vital rates: an integrated capture-recapture model of seasonal brook trout growth, survival and movement in a stream network.

PubMed

Letcher, Benjamin H; Schueller, Paul; Bassar, Ronald D; Nislow, Keith H; Coombs, Jason A; Sakrejda, Krzysztof; Morrissey, Michael; Sigourney, Douglas B; Whiteley, Andrew R; O'Donnell, Matthew J; Dubreuil, Todd L

2015-03-01

Modelling the effects of environmental change on populations is a key challenge for ecologists, particularly as the pace of change increases. Currently, modelling efforts are limited by difficulties in establishing robust relationships between environmental drivers and population responses. We developed an integrated capture-recapture state-space model to estimate the effects of two key environmental drivers (stream flow and temperature) on demographic rates (body growth, movement and survival) using a long-term (11 years), high-resolution (individually tagged, sampled seasonally) data set of brook trout (Salvelinus fontinalis) from four sites in a stream network. Our integrated model provides an effective context within which to estimate environmental driver effects because it takes full advantage of data by estimating (latent) state values for missing observations, because it propagates uncertainty among model components and because it accounts for the major demographic rates and interactions that contribute to annual survival. We found that stream flow and temperature had strong effects on brook trout demography. Some effects, such as reduction in survival associated with low stream flow and high temperature during the summer season, were consistent across sites and age classes, suggesting that they may serve as robust indicators of vulnerability to environmental change. Other survival effects varied across ages, sites and seasons, indicating that flow and temperature may not be the primary drivers of survival in those cases. Flow and temperature also affected body growth rates; these responses were consistent across sites but differed dramatically between age classes and seasons. Finally, we found that tributary and mainstem sites responded differently to variation in flow and temperature. Annual survival (combination of survival and body growth across seasons) was insensitive to body growth and was most sensitive to flow (positive) and temperature (negative) in the summer and fall. These observations, combined with our ability to estimate the occurrence, magnitude and direction of fish movement between these habitat types, indicated that heterogeneity in response may provide a mechanism providing potential resilience to environmental change. Given that the challenges we faced in our study are likely to be common to many intensive data sets, the integrated modelling approach could be generally applicable and useful. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Variation in survivorship of a migratory songbird throughout its annual cycle

USGS Publications Warehouse

Sillett, T. Scott; Holmes, Richard T.

2002-01-01

1. Demographic data from both breeding and non-breeding periods are needed to manage populations of migratory birds, many of which are declining in abundance and are of conservation concern. Although habitat associations, and to a lesser extent, reproductive biology, are known for many migratory species, few studies have measured survival rates of these birds at different parts of their annual cycle. 2. Cormack-Jolly-Seber models and Akaike's information criterion model selection were used to investigate seasonal variation in survival of a Nearctic - Neotropical migrant songbird, the black-throated blue warbler, Dendroica caerulescens. Seasonal and annual survival were estimated from resightings of colour-ringed individuals on breeding grounds in New Hampshire, USA from 1986 to 2000 and on winter quarters in Jamaica, West Indies from 1986 to 1999. Warblers were studied each year during the May-August breeding period in New Hampshire and during the October-March overwinter period in Jamaica. 3. In New Hampshire, males had higher annual survival (0.51 + 0.03) and recapture probabilities (0.93 + 0.03) than did females (survival: 0.40 + 0.04; recapture: 0'87 + 0.06). In Jamaica, annual survival (0.43 + 0.03) and recapture (0'95 + 0.04) probabilities did not differ between sexes. Annual survival and recapture probabilities of young birds (i.e. yearlings in New Hampshire and hatch-year birds in Jamaica) did not differ from adults, indicating that from the time hatch-year individuals acquire territories on winter quarters in mid-October, they survive as well as adults within the same habitat. 4. Monthly survival probabilities during the summer (May-August) and winter (October-March) stationary periods were high: 1'0 for males in New Hampshire, and 0.99 + 0.01 for males in Jamaica and for females in both locations. 5. These annual and seasonal survival estimates were used to calculate warbler survival for the migratory periods. Monthly survival probability during migration ranged from 0.77 to 0.81 -+ 0.02. Thus, apparent mortality rates were at least 15 times higher during migration compared to that in the stationary periods, and more than 85% of apparent annual mortality of D. caerulescens occurred during migration. 6. Additional data from multiple species, especially measures of habitat-specific demography and dispersal, will improve our understanding of the relative impacts of the breeding, migratory, and winter periods on population dynamics of migratory birds and thus enhance future conservation efforts.

Variation in survivorship of a migratory songbird throughout its annual cycle

USGS Publications Warehouse

Scott, Sillett T.; Holmes, Richard T.

2002-01-01

1. Demographic data from both breeding and non-breeding periods are needed to manage populations of migratory birds, many of which are declining in abundance and are of conservation concern. Although habitat associations, and to a lesser extent, reproductive biology, are known for many migratory species, few studies have measured survival rates of these birds at different parts of their annual cycle. 2. Cormack-Jolly-Seber models and Akaike's information criterion model selection were used to investigate seasonal variation in survival of a Nearctic - Neotropical migrant songbird, the black-throated blue warbler, Dendroica caerulescens. Seasonal and annual survival were estimated from resightings of colour-ringed individuals on breeding grounds in New Hampshire, USA from 1986 to 2000 and on winter quarters in Jamaica, West Indies from 1986 to 1999. Warblers were studied each year during the May-August breeding period in New Hampshire and during the October-March overwinter period in Jamaica. 3. In New Hampshire, males had higher annual survival (0.51 ?? 0.03) and recapture probabilities (0.93 ?? 0.03) than did females (survival: 0.40 ?? 0.04; recapture: 0.87 ?? 0.06). In Jamaica, annual survival (0.43 ?? 0.03) and recapture (0.95 ?? 0.04) probabilities did not differ between sexes. Annual survival and recapture probabilities of young birds (i.e. yearlings in New Hampshire and hatch-year birds in Jamaica) did not differ from adults, indicating that from the time hatch-year individuals acquire territories on winter quarters in mid-October, they survive as well as adults within the same habitat. 4. Monthly survival probabilities during the summer (May-August) and winter (October-March) stationary periods were high: 1.0 for males in New Hampshire, and 0.99 ?? 0.01 for males in Jamaica and for females in both locations. 5. These annual and seasonal survival estimates were used to calculate warbler survival for the migratory periods. Monthly survival probability during migration ranged from 0.77 to 0.81 ?? 0.02. Thus, apparent mortality rates were at least 15 times higher during migration compared to that in the stationary periods, and more than 85% of apparent annual mortality of D. caerulescens occurred during migration. 6. Additional data from multiple species, especially measures of habitat-specific demography and dispersal, will improve our understanding of the relative impacts of the breeding, migratory, and winter periods on population dynamics of migratory birds and thus enhance future conservation efforts.

Effects of habitat disturbance on survival rates of softshell turtles (Apalone spinifera) in an urban stream

USGS Publications Warehouse

Plummer, M.V.; Krementz, D.G.; Powell, L.A.; Mills, N.E.

2008-01-01

We monitored Spiny Softshell Turtles (Apalone spinifera) using mark-recapture during 1994-2005 in Gin Creek, Searcy, Arkansas. In 1997-2000 the creek bed and riparian zone were bulldozed in an effort to remove debris and improve water flow. This disturbance appeared to reduce the quantity and quality of turtle habitat. We tested for the potential effect of this habitat disturbance on the survival rates of marked turtles. We estimated annual survival rates for the population using models that allowed for variation in survival by state of maturation, year, and effects of the disturbance; we evaluated two different models of the disturbance impact. The first disturbance model incorporated a single change in survival rates, following the disturbance, whereas the second disturbance model incorporated three survival rates: pre- and postdisturbance, as well as a short-term decline during the disturbance. We used a state-transition model for our mark-recapture analysis, as softshells transition from juveniles to adults in a variable period of time. Our analysis indicated that survival varied by maturation state and was independent of a time trend or the disturbance. Annual survival rates were lower for juveniles (S?? = 0.717, SE = 0.039) than for adults (S?? = 0.836, SE = 0.025). Despite the dramatic habitat disturbance, we found no negative effects on survival rates. Our results demonstrate that, like a few other freshwater turtle species known to thrive in urban environments, populations of A. spinifera are resilient and can persist in urban environments despite periodic habitat disturbances. Copyright 2008 Society for the Study of Amphibians and Reptiles.

High CD8+ and absence of Foxp3+ T lymphocytes infiltration in gallbladder tumors correlate with prolonged patients survival.

PubMed

Fluxá, Paula; Rojas-Sepúlveda, Daniel; Gleisner, María Alejandra; Tittarelli, Andrés; Villegas, Pablo; Tapia, Loreto; Rivera, María Teresa; López, Mercedes Natalia; Catán, Felipe; Uribe, Mario; Salazar-Onfray, Flavio

2018-03-02

Gallbladder cancer (GBC), although infrequent in industrialized countries, has high incidence rates in certain world regions, being a leading cause of death among elderly Chilean women. Surgery is the only effective treatment, and a five-year survival rate of advanced-stage patients is less than 10%. Hence, exploring immunotherapy is relevant, although GBC immunogenicity is poorly understood. This study examined the relationship between the host immune response and GBC patient survival based on the presence of tumor-infiltrating lymphocytes at different disease stages. Tumor tissues from 80 GBC patients were analyzed by immunohistochemistry for the presence of CD3 + , CD4 + , CD8 + , and Foxp3 + T cell populations, and the results were associated with clinical stage and patient survival. The majority of tumor samples showed CD3 + T cell infiltration, which correlated with better prognosis, particularly in advanced disease stages. CD8 + , but not CD4 + , T cell infiltration correlated with improved survival, particularly in advanced disease stages. Interestingly, a < 1 CD4 + /CD8 + T cell ratio was related with increased survival. Additionally, the presence of Foxp3 + T cells correlated with decreased patient survival, whereas a ≤ 1 Foxp3 + /CD8 + T cell ratio was associated with improved patient survival. Depending on the disease stage, the presence of CD8 + and absence of Foxp3 + T cell populations in tumor tissues correlated with improved GBC patient survival, and thus represent potential markers for prognosis and management of advanced disease, and supports testing of immunotherapy.

Quantifying avian nest survival along an urbanization gradient using citizen- and scientist-generated data.

PubMed

Ryder, Thomas B; Reitsma, Robert; Evans, Brian; Marra, Peter P

2010-03-01

Despite the increasing pace of urbanization little is known about the factors that limit bird populations (i.e., population-level processes) within the urban/suburban land-use matrix. Here, we report rates of nest survival within the matrix of an urban land-use gradient in the greater Washington, D.C., USA, area for five common songbirds using data collected by scientists and citizens as part of a project called Neighborhood Nestwatch. Using program MARK, we modeled the effects of species, urbanization at multiple spatial scales (canopy cover and impervious surface), and observer (citizen vs. scientist) on nest survival of four open-cup and one cavity-nesting species. In addition, artificial nests were used to determine the relative impacts of specific predators along the land-use gradient. Our results suggest that predation on nests within the land-use matrix declines with urbanization but that there are species-specific differences. Moreover, variation in nest survival among species was best explained by urbanization metrics measured at larger "neighborhood" spatial scales (e.g., 1000 m). Trends were supported by data from artificial nests and suggest that variable predator communities (avian vs. mammalian) are one possible mechanism to explain differential nest survival. In addition, we assessed the quality of citizen science data and show that citizens had no negative effect on nest survival and provided estimates of nest survival comparable to Smithsonian biologists. Although birds nesting within the urban matrix experienced higher nest survival, individuals also faced a multitude of other challenges such as contaminants and invasive species, all of which could reduce adult survival.

Outcomes of thyroid cancer in African Americans.

PubMed

Hollenbeak, Christopher S; Wang, Li; Schneider, Patrick; Goldenberg, David

2011-01-01

Thyroid cancer, the most common endocrine cancer, is on the rise. It is less common in the African American (AA) population in the United States. Few studies have looked at outcome disparities for different patient populations, particularly those involving race. Using data from the SEER registry, we sought to determine whether five-year survival differed significantly between AA and White patients and, whether differences were due to patient or disease characteristics. Retrospective cohort analysis. Univariate comparisons were made using Student-t tests for continuous variables, chi-square tests for categorical variables. Survivor functions were estimated using Kaplan-Meier curves, and comparisons were made by log rank tests. 26,902 patients (25,210 White and 1,692 AA) were diagnosed with thyroid cancer between 1992 and 2006. Five-year survival defined as time from diagnosis to death from cancer within five years. AA had a significantly lower rate of five-year survival compared to Whites (96.5% vs 97.4%, P = .006). AA patients were 2.3 times more likely to be diagnosed with anaplastic disease (Risk ratio [RRI = 2.33 (95% CI: 1.52-3.58), P = .0001), and were also nearly 80% more likely to be diagnosed with follicular disease (RR = 1.78 [95% CI: 1.59-1.99], P < .0001). They were nearly twice as likely to have larger tumors (> or = 4 cm) than White patients (RR = 1.94 [95% CI: 1.78-2.12], P < .0001). AA had poorer survival from thyroid cancer relative to White patients; this difference may be explained by differences in disease characteristics such as a relatively higher rate of anaplastic thyroid cancer, follicular cancer and larger tumors at presentation.

Spatial variation in senescence rates in a bird metapopulation.

PubMed

Holand, H; Kvalnes, T; Gamelon, M; Tufto, J; Jensen, H; Pärn, H; Ringsby, T H; Sæther, B-E

2016-07-01

Investigating factors which affect the decline in survival with age, i.e. actuarial senescence, is important in order to understand how demographic rates vary in wild populations. Although the evidence for the occurrence of actuarial senescence in wild populations is growing, very few studies have compared actuarial senescence rates between wild populations of the same species. We used data from a long-time study of demography of house sparrows (Passer domesticus) to investigate differences in rates of actuarial senescence between habitats and sub-populations. We also investigated whether rates of actuarial senescence differed between males and females. We found that rates of actuarial senescence showed large spatial variation. We also found that the onset of actuarial senescence varied between sub-populations. However, these differences were not significantly explained by a general difference in habitat type. We also found no significant difference in actuarial senescence rates between males and females. This study shows that senescence rates in natural populations may vary significantly between sub-populations and that failing to account for such differences may give a biased estimate of senescence rates of a species.

Effect of Canopy Position on Germination and Seedling Survival of Epiphytic Bromeliads in a Mexican Humid Montane Forest

PubMed Central

WINKLER, MANUELA; HÜLBER, KARL; HIETZ, PETER

2005-01-01

• Background and Aims Seeds of epiphytes must land on branches with suitable substrates and microclimates to germinate and for the resulting seedlings to survive. It is important to understand the fate of seeds and seedlings in order to model populations, but this is often neglected when only established plants are included in analyses. • Methods The seeds of five bromeliad species were exposed to different canopy positions in a Mexican montane forest, and germination and early seedling survival were recorded. Additionally, the survival of naturally dispersed seedlings was monitored in a census over 2·5 years. Survival analysis, a procedure rarely used in plant ecology, was used to study the influence of branch characteristics and light on germination and seedling survival in natural and experimental populations. • Key Results Experimental germination percentages ranged from 7·2 % in Tillandsia deppeana to 33·7 % in T. juncea, but the seeds of T. multicaulis largely failed to germinate. Twenty months after exposure between 3·5 and 9·4 % of the seedlings were still alive. There was no evidence that canopy position affected the probability of germination, but time to germination was shorter in less exposed canopy positions indicating that higher humidity accelerates germination. More experimental seedlings survived when canopy openness was high, whereas survival in census-seedlings was influenced by moss cover. While mortality decreased steadily with age in juveniles of the atmospheric Tillandsia, in the more mesomorphic Catopsis sessiliflora mortality increased dramatically in the dry season. • Conclusions Seedling mortality, rather than the failure to germinate, accounts for the differential distribution of epiphytes within the canopy studied. With few safe sites to germinate and high seedling mortality, changes of local climate may affect epiphyte populations primarily through their seedling stage. PMID:15767270

Differences in incidence and survival of oral cavity and pharyngeal cancers between Germany and the United States depend on the HPV-association of the cancer site.

PubMed

Jansen, L; Buttmann-Schweiger, N; Listl, S; Ressing, M; Holleczek, B; Katalinic, A; Luttmann, S; Kraywinkel, K; Brenner, H

2018-01-01

The epidemiology of squamous cell oral cavity and pharyngeal cancers (OCPC) has changed rapidly during the last years, possibly due to an increase of human papilloma virus (HPV) positive tumors and successes in tobacco prevention. Here, we compare incidence and survival of OCPC by HPV-relation of the site in Germany and the United States (US). Age-standardized and age-specific incidence and 5-year relative survival was estimated using data from population-based cancer registries in Germany and the US Surveillance Epidemiology and End Results (SEER) 13 database. Incidence was estimated for each year between 1999 and 2013. Relative survival for 2002-2005, 2006-2009, and 2010-2013 was estimated using period analysis. The datasets included 52,787 and 48,861 cases with OCPC diagnosis between 1997 and 2013 in Germany and the US. Incidence was much higher in Germany compared to the US for HPV-unrelated OCPC and more recently also for HPV-related OCPC in women. Five-year relative survival differences between Germany and the US were small for HPV-unrelated OCPC. For HPV-related OCPC, men had higher survival in the US (62.1%) than in Germany (45.4%) in 2010-2013. These differences increased over time and were largest in younger patients and stage IV disease without metastasis. In contrast, women had comparable survival for HPV-related OCPC in both countries. Strong survival differences between Germany and the US were observed for HPV-related OCPC in men, which might be explained by differences in HPV-attributable proportions. Close monitoring of the epidemiology of OCPC in each country is needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Black bear population and connectivity in the Sky Islands of Mexico and the United States

Treesearch

N. E. Lara-Diaz; C. A. Lopez-Gonzalez; H. Coronel-Arellano; A. Gonzalez-Bernal

2013-01-01

The Sky Island region is a mountainous region surrounded by grasslands, deserts and intermountain valleys, located between Mexico and the United States. However, different land management and human impact can have an effect on its wildlife populations. Currently, the border wall poses an immediate threat to the survival of black bears (Ursus americanus), considered an...

Henslow's sparrow winter-survival estimates and response to prescribed burning

USGS Publications Warehouse

Thatcher, B.S.; Krementz, D.G.; Woodrey, M.S.

2006-01-01

Wintering Henslow's sparrow (Ammodramus henslowii) populations rely on lands managed with prescribed burning, but the effects of various burn regimes on their overwinter survival are unknown. We studied wintering Henslow's sparrows in coastal pine savannas at the Mississippi Sandhill Crane National Wildlife Refuge, Jackson County, Mississippi, USA, during January and February 2001 and 2002. We used the known-fate modeling procedure in program MARK to evaluate the effects of burn age (1 or 2 growing seasons elapsed), burn season (growing, dormant), and calendar year on the survival rates of 83 radiomarked Henslow's sparrows. We found strong evidence that Henslow's sparrow survival rates differed by burn age (with higher survival in recently burned sites) and by year (with lower survival rates in 2001 likely because of drought conditions). We found some evidence that survival rates also differed by bum season (with higher survival in growing-season sites), although the effects of burn season were only apparent in recently burned sites. Avian predation was the suspected major cause of mortality (causing 6 of 14 deaths) with 1 confirmed loggerhead shrike (Lanius ludovicianus) depredation. Our results indicated that recently burned savannas provide high-quality wintering habitats and suggested that managers can improve conditions for wintering Henslow's sparrows by burning a large percentage of savannas each year.

Landscape‐level patterns in fawn survival across North America

USGS Publications Warehouse

Gingery, Tess M.; Diefenbach, Duane R.; Wallingford, Bret D.; Rosenberry, Christopher S.

2018-01-01

A landscape‐level meta‐analysis approach to examining early survival of ungulates may elucidate patterns in survival not evident from individual studies. Despite numerous efforts, the relationship between fawn survival and habitat characteristics remains unclear and there has been no attempt to examine trends in survival across landscape types with adequate replication. In 2015–2016, we radiomarked 98 white‐tailed deer (Odocoileus virginianus) fawns in 2 study areas in Pennsylvania. By using a meta‐analysis approach, we compared fawn survival estimates from across North America using published data from 29 populations in 16 states to identify patterns in survival and cause‐specific mortality related to landscape characteristics, predator communities, and deer population density. We modeled fawn survival relative to percentage of agricultural land cover and deer density. Estimated average survival to 3–6 months of age was 0.414 ± 0.062 (SE) in contiguous forest landscapes (no agriculture) and for every 10% increase in land area in agriculture, fawn survival increased 0.049 ± 0.014. We classified cause‐specific mortality as human‐caused, natural (excluding predation), and predation according to agriculturally dominated, forested, and mixed (i.e., both agricultural and forest cover) landscapes. Predation was the greatest source of mortality in all landscapes. Landscapes with mixed forest and agricultural cover had greater proportions and rates of human‐caused mortalities, and lower proportions and rates of mortality due to predators, when compared to forested landscapes. Proportion and rate of natural deaths did not differ among landscapes. We failed to detect any relationship between fawn survival and deer density. The results highlight the need to consider multiple spatial scales when accounting for factors that influence fawn survival. Furthermore, variation in mortality sources and rates among landscapes indicate the potential for altered landscape mosaics to influence fawn survival rates. Wildlife managers can use the meta‐analysis to identify factors that will facilitate comparisons of results among studies and advance a better understanding of patterns in fawn survival.

Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.

HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation processmore » including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness landscapes influenced the shape of phylogenies, diversity trends, and survival of virus with latent genomic fragments. Furthermore, our model predicts that the persistence of latent genomic fragments from multiple different ancestral origins increases sequence diversity in plasma for reasonable fitness landscapes.« less

Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

DOE PAGES

Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; ...

2015-12-22

HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation processmore » including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness landscapes influenced the shape of phylogenies, diversity trends, and survival of virus with latent genomic fragments. Furthermore, our model predicts that the persistence of latent genomic fragments from multiple different ancestral origins increases sequence diversity in plasma for reasonable fitness landscapes.« less

Dispersal-mediated effect of microhabitat availability and density dependence determine population dynamics of a forest floor web spider.

PubMed

Takada, Mayura B; Miyashita, Tadashi

2014-09-01

Landscapes in nature can be viewed as a continuum of small total habitable area with high fragmentation to widely spreading habitats. The dispersal-mediated rescue effect predominates in the former landscapes, while classical density-dependent processes generally prevail in widely spread habitats. A similar principle should be applied to populations of organisms utilizing microhabitats in limited supply. To test this hypothesis, we examined the population dynamics of a web spider, Neriene brongersmai, in 16 populations with varying degrees of microhabitat availability, and we explored whether: (i) high microhabitat availability improves survival rate during density-independent movement, while the resultant high density reduces survival rate in a density-dependent manner; and (ii) temporal population stability increases with microhabitat availability at the population level. Furthermore, we conducted two types of field experiments to verify whether high microhabitat availability actually reduces mortality associated with web-site movement. Field observations revealed that demographic change in N. brongersmai populations was affected by three factors at different stages, namely the microhabitat limitation from the early to late juvenile stages, the density dependence from the late juvenile to adult stages and the food limitation from the adult to the next early juvenile stages. In addition, there was a tendency for a positive association between population stability and microhabitat availability at the population level. A small-scale experiment, where the frequency of spider web relocation was equalized artificially, revealed that high microhabitat availability elevated the survival rate during a movement event between web-sites. The larger spatiotemporal scale experiment also revealed an improved spider survival rate following treatment with high microhabitat availability, even though spider density was kept at a relatively low level. The population dynamics of N. brongersmai can be determined primarily by density-independent processes based on web-site fragmentation and density-dependent processes driven by interference competition. We conclude that depending on the amount of habitat resources, the relative importance of the two contrasting paradigms-equilibrium and non-equilibrium-appears to vary, even within a particular system. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Evaluating mortality rates with a novel integrated framework for nonmonogamous species.

PubMed

Tenan, Simone; Iemma, Aaron; Bragalanti, Natalia; Pedrini, Paolo; De Barba, Marta; Randi, Ettore; Groff, Claudio; Genovart, Meritxell

2016-12-01

The conservation of wildlife requires management based on quantitative evidence, and especially for large carnivores, unraveling cause-specific mortalities and understanding their impact on population dynamics is crucial. Acquiring this knowledge is challenging because it is difficult to obtain robust long-term data sets on endangered populations and, usually, data are collected through diverse sampling strategies. Integrated population models (IPMs) offer a way to integrate data generated through different processes. However, IPMs are female-based models that cannot account for mate availability, and this feature limits their applicability to monogamous species only. We extended classical IPMs to a two-sex framework that allows investigation of population dynamics and quantification of cause-specific mortality rates in nonmonogamous species. We illustrated our approach by simultaneously modeling different types of data from a reintroduced, unhunted brown bear (Ursus arctos) population living in an area with a dense human population. In a population mainly driven by adult survival, we estimated that on average 11% of cubs and 61% of adults died from human-related causes. Although the population is currently not at risk, adult survival and thus population dynamics are driven by anthropogenic mortality. Given the recent increase of human-bear conflicts in the area, removal of individuals for management purposes and through poaching may increase, reversing the positive population growth rate. Our approach can be generalized to other species affected by cause-specific mortality and will be useful to inform conservation decisions for other nonmonogamous species, such as most large carnivores, for which data are scarce and diverse and thus data integration is highly desirable. © 2016 Society for Conservation Biology.

[Survival capacity of Corynebacterium pseudotuberculosis biovar ovis in different soil types from Chubut, Argentine Patagonia].

PubMed

Alvarez, Laura; William, Aillin; Castro, Isabel; Valenzuela, Fernanda; Estevao Belchior, Silvia

Corynebacterium pseudotuberculosis is transmitted among sheep in Argentine Patagonia causing pseudotuberculosis. The bacterium penetrates the skin or mucous membrane wounds, infecting the superficial lymph nodes and viscera. When surface abscesses are cut during shearing, they drain their purulent contents and contaminate tools and the soil. The objective of this work was to evaluate the survival capacity of C. pseudotuberculosis over time, in soils from the extra-Andean Patagonia region. Five types of superficial soils were collected from different areas in Chubut province (extra-Andean Patagonia), having distinctive physicochemical properties including organic matter content (very high to nonexistent), pH (neutral to strongly alkaline), electrical conductivity (saline to non-saline) and texture (sandy, clayey, silty loam). Different aliquots of each type of soil were inoculated with C. pseudotuberculosis PAT10 strain isolated from a Patagonian sheep, and were stored at room temperature. The number of surviving bacteria was determined at various times. Sixty percent (60%) of the inoculated C. pseudotuberculosis population survived for 80 to 210 days in soils with moderate to high organic matter content respectively. Silty soils favored bacterial survival, whereas the variables pH and salinity had no effect on survival. Copyright © 2016 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Coronary artery bypass surgery: are outcomes influenced by demographics or ability to pay?

PubMed

Mancini, M C; Cush, E M; Sweatman, K; Dansby, J

2001-05-01

To examine the relation of financial status and demographics to the outcomes of coronary artery bypass surgery (CABG) in the public hospital setting. Coronary artery bypass surgery is one of the most expensive and frequently performed surgical procedures in the United States. Considerable controversy surrounds the accessibility to quality cardiac care of indigent and minority populations. This study examines the hypothesis that demographics rather than access to care and economics influences outcomes in CABG. A retrospective review of 1,556 charts of patients who underwent CABG at Louisiana State University Health Sciences Center-Shreveport, a public hospital, during a 10-year period was performed. The parameters analyzed included sex, age, race, education, ejection fraction, comorbidities, surgical parameters, economics, complications, and cost of care. Comparisons were made between the insured and uninsured groups. Univariate statistical analysis was used to assess differences between groups. Kaplan-Meier survival curves were also generated. Two thirds of the patients were uninsured. The mean age of the uninsured patients was significantly lower than that of the insured patients. Ejection fractions were comparable. Comorbidities were similar, with a greater percentage of tobacco use in the uninsured population. Kaplan-Meier survival curves showed that the uninsured group had better overall survival and that the insured group manifested an increased rate of late death. The financially challenged population appears to present for treatment earlier in life with coronary artery disease. Risk factors between the two groups were similar, except that tobacco use appears to be a significant problem in the disadvantaged population. The disease severity in both populations appeared to be similar; however, the uninsured patients had equivalent early survival with better late survival. Access to care in both groups was equal. In the public hospital setting for the disease state described, the financially challenged are afforded access to the current treatment technology with quality results.

Ethnicity and health care in cervical cancer survival: comparisons between a Filipino resident population, Filipino-Americans, and Caucasians.

PubMed

Redaniel, Maria Theresa; Laudico, Adriano; Mirasol-Lumague, Maria Rica; Gondos, Adam; Uy, Gemma Leonora; Toral, Jean Ann; Benavides, Doris; Brenner, Hermann

2009-08-01

Few studies have assessed and compared cervical cancer survival between developed and developing countries, or between ethnic groups within a country. Fewer still have addressed how much of the international or interracial survival differences can be attributed to ethnicity or health care. To determine the role of ethnicity and health care, 5-year survival of patients with cervical cancer was compared between patients in the Philippines and Filipino-Americans, who have the same ethnicity, and between Filipino-Americans and Caucasians, who have the same health care system. Cervical cancer databases from the Manila and Rizal Cancer Registries and Surveillance, Epidemiology, and End Results 13 were used. Age-adjusted 5-year survival estimates were computed and compared between the three patient groups. Using Cox proportional hazards modeling, potential determinants of survival differences were examined. Overall 5-year relative survival was similar in Filipino-Americans (68.8%) and Caucasians (66.6%), but was lower for Philippine residents (42.9%). Although late stage at diagnosis explained a large proportion of the survival differences between Philippine residents and Filipino-Americans, excess mortality prevailed after adjustment for stage, age, and morphology in multivariate analysis [relative risk (RR), 2.07; 95% confidence interval (CI), 1.68-2.55]. Excess mortality decreased, but persisted, when treatments were included in the multivariate models (RR, 1.78; 95% CI, 1.41-2.23). A moderate, marginally significant excess mortality was found among Caucasians compared with Filipino-Americans (adjusted RR, 1.22; 95% CI, 1.01-1.47). The differences in cervical cancer survival between patients in the Philippines and in the United States highlight the importance of enhanced health care and access to diagnostic and treatment facilities in the Philippines.

Chronic consequences of acute injuries: worse survival after discharge.

PubMed

Shafi, Shahid; Renfro, Lindsay A; Barnes, Sunni; Rayan, Nadine; Gentilello, Larry M; Fleming, Neil; Ballard, David

2012-09-01

The Trauma Quality Improvement Program uses inhospital mortality to measure quality of care, which assumes patients who survive injury are not likely to suffer higher mortality after discharge. We hypothesized that survival rates in trauma patients who survive to discharge remain stable afterward. Patients treated at an urban Level I trauma center (2006-2008) were linked with the Social Security Administration Death Master File. Survival rates were measured at 30, 90, and 180 days and 1 and 2 years from injury among two groups of trauma patients who survived to discharge: major trauma (Abbreviated Injury Scale score ≥ 3 injuries, n = 2,238) and minor trauma (Abbreviated Injury Scale score ≤ 2 injuries, n = 1,171). Control groups matched to each trauma group by age and sex were simulated from the US general population using annual survival probabilities from census data. Kaplan-Meier and log-rank analyses conditional upon survival to each time point were used to determine changes in risk of mortality after discharge. Cox proportional hazards models with left truncation at the time of discharge were used to determine independent predictors of mortality after discharge. The survival rate in trauma patients with major injuries was 92% at 30 days posttrauma and declined to 84% by 3 years (p > 0.05 compared with general population). Minor trauma patients experienced a survival rate similar to the general population. Age and injury severity were the only independent predictors of long-term mortality given survival to discharge. Log-rank tests conditional on survival to each time point showed that mortality risk in patients with major injuries remained significantly higher than the general population for up to 6 months after injury. The survival rate of trauma patients with major injuries remains significantly lower than survival for minor trauma patients and the general population for several months postdischarge. Surveillance for early identification and treatment of complications may be needed for trauma patients with major injuries. Prognostic study, level III.

Survival patterns and mortality in the North American population of silvered leaf monkeys (Trachypithecus cristatus).

PubMed

Shelmidine, Nichole; McAloose, Denise; McCann, Colleen

2013-03-01

This study examines mortality in the North American (N.A.) population of silvered leaf monkeys (Trachypithecus cristatus) maintained in Association of Zoos and Aquarium's zoos. Understanding the causes of death associated with mortality rates (MR) can highlight relative susceptibility to intrinsic/extrinsic factors and differences between age and sex classes. Overall, life tables can provide insight into a species' population dynamics. We expect that the MR will fit the general mammalian and primate trends of a U-shaped curve when graphed, that males will have a higher MR and shorter life expectancy than females and that infant survival will be higher in captivity than in wild populations. Our results indicate that the N.A. captive population fits expected MR trends of a U-shaped curve. However, no differences in MR or life expectancy were found between the sexes. Infant survivorship did not differ from the wild or other leaf monkey populations (both captive and wild). The majority of infant deaths occurred on day 1 of life (52.8% of all infant deaths) and infant survivorship to 1 year was 66%. Neonates (n = 6, 31.6%) and infants (n = 4, 44.4%) died from trauma, juveniles (n = 2, 33.3%) from nutritional reasons, adults from non-infectious diseases (n = 7, 29.2%) and from post-surgical complications (n = 7, 29.2%), and older adults from idiopathic diseases (n = 4, 26.7%) and non-infectious diseases (n = 4, 26.7%). Only older adult males died from degenerative diseases (i.e., heart failure, n = 3, 42.9%). In general, this captive population demonstrated some similar trends to those observed in mammalian and Old World monkey populations. © 2013 Wiley Periodicals, Inc.

Survival analysis: comparing peritoneal dialysis and hemodialysis in Taiwan.

PubMed

Huang, Chiu-Ching; Cheng, Kuang-Fu; Wu, Hong-Dar Isaac

2008-06-01

Comparisons of survival in patients on peritoneal dialysis (PD) and on hemodialysis (HD) have been conducted in many Western countries, but publications on this subject in Asian populations are scarce. The present study estimated the survival and the relative mortality hazard for HD and PD patients in Taiwan. Incident end-stage renal disease patients reported to the Taiwan Renal Registry during 1995 - 2002 were included in the study. Patients had to be 20 years of age or older and had to have survived for the first 90 days on dialysis. A total of 45,820 incident HD and 2,809 incident PD patients formed the study population. Patients on PD were treated mainly with traditional glucose-based solutions. Using an intent-to-treat analysis, the Cox proportional hazards (CPH) model was applied to identify the factors that predict survival by treatment modality. Subgroup analyses were conducted by stratifying patients according to sex, comorbidity, age, and diabetes status. Kaplan-Meier estimates were used to explore the survival of HD and PD patients. Adjustments were implemented using the CPH model. The overall 1-year, 2-year, 3-year, 5-year and 10-year survival rates for PD patients were 89.8%, 77.6%, 67.6%, 55.5%, and 35% respectively. The equivalent survival rates for HD patients were 87.5%, 76.6%, 68.1%, 54.3%, and 33.8%. The differences were not statistically significant (p = 0.125). The CPH analysis stratified by diabetes status and age revealed that PD patients 55 years of age or younger and nondiabetic had a lower mortality ratio (MR) of 0.94. But the MR increased to 1.31 for nondiabetic patients older than 55. The MR for PD versus HD further increased to 1.72 for diabetic patients 55 years of age or younger, and to 1.99 for diabetic patients older than 55. After adjusting for both demographic and clinical case-mix differences, PD and HD patients were observed to have similar long-term survival. Subgroup analyses revealed that, among diabetic patients and patients older than 55, those on HD experienced better survival than did those on PD.

Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA).

PubMed

Agha, Mickey; Lovich, Jeffrey E; Ennen, Joshua R; Augustine, Benjamin; Arundel, Terence R; Murphy, Mason O; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V; Price, Steven J

2015-08-01

With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

Turbines and terrestrial vertebrates: variation in tortoise survivorship between a wind energy facility and an adjacent undisturbed wildland area in the desert southwest (USA)

USGS Publications Warehouse

Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin J.; Arundel, Terry; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David F.; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

2015-01-01

With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises (Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18 year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility scale wind energy on long-lived terrestrial vertebrates.

Turbines and Terrestrial Vertebrates: Variation in Tortoise Survivorship Between a Wind Energy Facility and an Adjacent Undisturbed Wildland Area in the Desert Southwest (USA)

NASA Astrophysics Data System (ADS)

Agha, Mickey; Lovich, Jeffrey E.; Ennen, Joshua R.; Augustine, Benjamin; Arundel, Terence R.; Murphy, Mason O.; Meyer-Wilkins, Kathie; Bjurlin, Curtis; Delaney, David; Briggs, Jessica; Austin, Meaghan; Madrak, Sheila V.; Price, Steven J.

2015-08-01

With the recent increase in utility-scale wind energy development, researchers have become increasingly concerned how this activity will affect wildlife and their habitat. To understand the potential impacts of wind energy facilities (WEF) post-construction (i.e., operation and maintenance) on wildlife, we compared differences in activity centers and survivorship of Agassiz's desert tortoises ( Gopherus agassizii) inside or near a WEF to neighboring tortoises living near a wilderness area (NWA) and farther from the WEF. We found that the size of tortoise activity centers varied, but not significantly so, between the WEF (6.25 ± 2.13 ha) and adjacent NWA (4.13 ± 1.23 ha). However, apparent survival did differ significantly between the habitat types: over the 18-year study period apparent annual survival estimates were 0.96 ± 0.01 for WEF tortoises and 0.92 ± 0.02 for tortoises in the NWA. High annual survival suggests that operation and maintenance of the WEF has not caused considerable declines in the adult population over the past two decades. Low traffic volume, enhanced resource availability, and decreased predator populations may influence annual survivorship at this WEF. Further research on these proximate mechanisms and population recruitment would be useful for mitigating and managing post-development impacts of utility-scale wind energy on long-lived terrestrial vertebrates.

Implementing a novel movement-based approach to inferring parturition and neonate caribou calf survival.

PubMed

Bonar, Maegwin; Ellington, E Hance; Lewis, Keith P; Vander Wal, Eric

2018-01-01

In ungulates, parturition is correlated with a reduction in movement rate. With advances in movement-based technologies comes an opportunity to develop new techniques to assess reproduction in wild ungulates that are less invasive and reduce biases. DeMars et al. (2013, Ecology and Evolution 3:4149-4160) proposed two promising new methods (individual- and population-based; the DeMars model) that use GPS inter-fix step length of adult female caribou (Rangifer tarandus caribou) to infer parturition and neonate survival. Our objective was to apply the DeMars model to caribou populations that may violate model assumptions for retrospective analysis of parturition and calf survival. We extended the use of the DeMars model after assigning parturition and calf mortality status by examining herd-wide distributions of parturition date, calf mortality date, and survival. We used the DeMars model to estimate parturition and calf mortality events and compared them with the known parturition and calf mortality events from collared adult females (n = 19). We also used the DeMars model to estimate parturition and calf mortality events for collared female caribou with unknown parturition and calf mortality events (n = 43) and instead derived herd-wide estimates of calf survival as well as distributions of parturition and calf mortality dates and compared them to herd-wide estimates generated from calves fitted with VHF collars (n = 134). For our data, the individual-based method was effective at predicting calf mortality, but was not effective at predicting parturition. The population-based method was more effective at predicting parturition but was not effective at predicting calf mortality. At the herd-level, the predicted distributions of parturition date from both methods differed from each other and from the distribution derived from the parturition dates of VHF-collared calves (log-ranked test: χ2 = 40.5, df = 2, p < 0.01). The predicted distributions of calf mortality dates from both methods were similar to the observed distribution derived from VHF-collared calves. Both methods underestimated herd-wide calf survival based on VHF-collared calves, however, a combination of the individual- and population-based methods produced herd-wide survival estimates similar to estimates generated from collared calves. The limitations we experienced when applying the DeMars model could result from the shortcomings in our data violating model assumptions. However despite the differences in our caribou systems, with proper validation techniques the framework in the DeMars model is sufficient to make inferences on parturition and calf mortality.

Implementing a novel movement-based approach to inferring parturition and neonate caribou calf survival

PubMed Central

Ellington, E. Hance; Lewis, Keith P.; Vander Wal, Eric

2018-01-01

In ungulates, parturition is correlated with a reduction in movement rate. With advances in movement-based technologies comes an opportunity to develop new techniques to assess reproduction in wild ungulates that are less invasive and reduce biases. DeMars et al. (2013, Ecology and Evolution 3:4149–4160) proposed two promising new methods (individual- and population-based; the DeMars model) that use GPS inter-fix step length of adult female caribou (Rangifer tarandus caribou) to infer parturition and neonate survival. Our objective was to apply the DeMars model to caribou populations that may violate model assumptions for retrospective analysis of parturition and calf survival. We extended the use of the DeMars model after assigning parturition and calf mortality status by examining herd-wide distributions of parturition date, calf mortality date, and survival. We used the DeMars model to estimate parturition and calf mortality events and compared them with the known parturition and calf mortality events from collared adult females (n = 19). We also used the DeMars model to estimate parturition and calf mortality events for collared female caribou with unknown parturition and calf mortality events (n = 43) and instead derived herd-wide estimates of calf survival as well as distributions of parturition and calf mortality dates and compared them to herd-wide estimates generated from calves fitted with VHF collars (n = 134). For our data, the individual-based method was effective at predicting calf mortality, but was not effective at predicting parturition. The population-based method was more effective at predicting parturition but was not effective at predicting calf mortality. At the herd-level, the predicted distributions of parturition date from both methods differed from each other and from the distribution derived from the parturition dates of VHF-collared calves (log-ranked test: χ2 = 40.5, df = 2, p < 0.01). The predicted distributions of calf mortality dates from both methods were similar to the observed distribution derived from VHF-collared calves. Both methods underestimated herd-wide calf survival based on VHF-collared calves, however, a combination of the individual- and population-based methods produced herd-wide survival estimates similar to estimates generated from collared calves. The limitations we experienced when applying the DeMars model could result from the shortcomings in our data violating model assumptions. However despite the differences in our caribou systems, with proper validation techniques the framework in the DeMars model is sufficient to make inferences on parturition and calf mortality. PMID:29466451

Fire and ice: volcanic and glacial impacts on the phylogeography of the New Zealand forest fern Asplenium hookerianum.

PubMed

Shepherd, Lara D; Perrie, Leon R; Brownsey, Patrick J

2007-11-01

In the Southern Hemisphere there has been little phylogeographical investigation of forest refugia sites during the last glacial. Hooker's spleenwort, Asplenium hookerianum, is a fern that is found throughout New Zealand. It is strongly associated with forest and is a proxy for the survival of woody vegetation during the last glacial maximum. DNA sequence data from the chloroplast trnL-trnF locus were obtained from 242 samples, including c. 10 individuals from each of 21 focal populations. Most populations contained multiple, and in many cases unique, haplotypes, including those neighbouring formerly glaciated areas, while the predominant inference from nested clade analysis was restricted gene flow with isolation by distance. These results suggest that A. hookerianum survived the last glacial maximum in widespread populations of sufficient size to retain the observed phylogeography, and therefore that the sheltering woody vegetation must have been similarly abundant. This is consistent with palynological interpretations for the survival in New Zealand of thermophilous forest species at considerably smaller distances from the ice sheets than recorded for the Northern Hemisphere. Eastern and central North Island populations of A. hookerianum were characterized by a different subset of haplotypes to populations from the remainder of the country. A similar east-west phylogeographical pattern has been detected in a diverse array of taxa, and has previously been attributed to recurrent vulcanism in the central North Island.

Annual survival rate estimate of satellite transmitter–marked eastern population greater sandhill cranes

USGS Publications Warehouse

Fronczak, David L.; Andersen, David E.; Hanna, Everett E.; Cooper, Thomas R.

2015-01-01

Several surveys have documented the increasing population size and geographic distribution of Eastern Population greater sandhill cranes Grus canadensis tabida since the 1960s. Sport hunting of this population of sandhill cranes started in 2012 following the provisions of the Eastern Population Sandhill Crane Management Plan. However, there are currently no published estimates of Eastern Population sandhill crane survival rate that can be used to inform harvest management. As part of two studies of Eastern Population sandhill crane migration, we deployed solar-powered global positioning system platform transmitting terminals on Eastern Population sandhill cranes (n  =  42) at key concentration areas from 2009 to 2012. We estimated an annual survival rate for Eastern Population sandhill cranes from data resulting from monitoring these cranes by using the known-fates model in the MARK program. Estimated annual survival rate for adult Eastern Population sandhill cranes was 0.950 (95% confidence interval  =  0.885–0.979) during December 2009–August 2014. All fatalities (n  =  5) occurred after spring migration in late spring and early summer. We were unable to determine cause of death for crane fatalities in our study. Our survival rate estimate will be useful when combined with other population parameters such as the population index derived from the U.S. Fish and Wildlife Service fall survey, harvest, and recruitment rates to assess the effects of harvest on population size and trend and evaluate the effectiveness of management strategies.

Lack of active follow-up of cancer patients in Chennai, India: implications for population-based survival estimates

PubMed Central

Rama, Ranganathan; Shanta, Viswanathan

2008-01-01

Abstract Objective To measure the bias in absolute cancer survival estimates in the absence of active follow-up of cancer patients in developing countries. Methods Included in the study were all incident cases of the 10 most common cancers and corresponding subtypes plus all tobacco-related cancers not ranked among the top 10 that were registered in the population-based cancer registry in Chennai, India, during 1990–1999 and followed through 2001. Registered incident cases were first matched with those in the all-cause mortality database from the vital statistics division of the Corporation of Chennai. Unmatched incident cancer cases were then actively followed up to determine their survival status. Absolute survival was estimated by using an actuarial method and applying different assumptions regarding the survival status (alive/dead) of cases under passive and active follow-up. Findings Before active follow-up, matches between cases ranged from 20% to 66%, depending on the site of the primary tumour. Active follow-up of unmatched incident cases revealed that 15% to 43% had died by the end of the follow-up period, while the survival status of 4% to 38% remained unknown. Before active follow-up of cancer patients, 5-year absolute survival was estimated to be between 22% and 47% higher, than when conventional actuarial assumption methods were applied to cases that were lost to follow-up. The smallest survival estimates were obtained when cases lost to follow-up were excluded from the analysis. Conclusion Under the conditions that prevail in India and other developing countries, active follow-up of cancer patients yields the most reliable estimates of cancer survival rates. Passive case follow-up alone or applying standard methods to estimate survival is likely to result in an upward bias. PMID:18670662

Extinction and survival in two-species annihilation

NASA Astrophysics Data System (ADS)

Amar, J. G.; Ben-Naim, E.; Davis, S. M.; Krapivsky, P. L.

2018-02-01

We study diffusion-controlled two-species annihilation with a finite number of particles. In this stochastic process, particles move diffusively, and when two particles of opposite type come into contact, the two annihilate. We focus on the behavior in three spatial dimensions and for initial conditions where particles are confined to a compact domain. Generally, one species outnumbers the other, and we find that the difference between the number of majority and minority species, which is a conserved quantity, controls the behavior. When the number difference exceeds a critical value, the minority becomes extinct and a finite number of majority particles survive, while below this critical difference, a finite number of particles of both species survive. The critical difference Δc grows algebraically with the total initial number of particles N , and when N ≫1 , the critical difference scales as Δc˜N1 /3 . Furthermore, when the initial concentrations of the two species are equal, the average number of surviving majority and minority particles, M+ and M-, exhibit two distinct scaling behaviors, M+˜N1 /2 and M-˜N1 /6 . In contrast, when the initial populations are equal, these two quantities are comparable M+˜M-˜N1 /3 .

Age structure changes and extraordinary lifespan in wild medfly populations.

PubMed

Carey, James R; Papadopoulos, Nikos T; Müller, Hans-Georg; Katsoyannos, Byron I; Kouloussis, Nikos A; Wang, Jane-Ling; Wachter, Kenneth; Yu, Wei; Liedo, Pablo

2008-06-01

The main purpose of this study was to test the hypotheses that major changes in age structure occur in wild populations of the Mediterranean fruit fly (medfly) and that a substantial fraction of individuals survive to middle age and beyond (> 3-4 weeks). We thus brought reference life tables and deconvolution models to bear on medfly mortality data gathered from a 3-year study of field-captured individuals that were monitored in the laboratory. The average time-to-death of captured females differed between sampling dates by 23.9, 22.7, and 37.0 days in the 2003, 2004, and 2005 field seasons, respectively. These shifts in average times-to-death provided evidence of changes in population age structure. Estimates indicated that middle-aged medflies (> 30 days) were common in the population. A surprise in the study was the extraordinary longevity observed in field-captured medflies. For example, 19 captured females but no reference females survived in the laboratory for 140 days or more, and 6 captured but no reference males survived in the laboratory for 170 days or more. This paper advances the study of aging in the wild by introducing a new method for estimating age structure in insect populations, demonstrating that major changes in age structure occur in field populations of insects, showing that middle-aged individuals are common in the wild, and revealing the extraordinary lifespans of wild-caught individuals due to their early life experience in the field.

Pumas affect elk dynamics in absence of other large carnivores

Treesearch

Chadwick P. Lehman; Christopher T. Rota; Jarod D. Raithel; Joshua J. Millspaugh

2017-01-01

We investigated survival, reproduction, and population growth (λ) for a declining elk (Cervus canadensis nelsoni) population in South Dakota, USA, 2011-2015. We obtained survival data from 125 calves and 34 yearlings. We determined survival and pregnancy rates for 42 adults (2-8 years old) and 39 old adults (≥8 years old). We combined population vital rates into a...

Demographic origins of skewed operational and adult sex ratios: perturbation analyses of two-sex models.

PubMed

Veran, Sophie; Beissinger, Steven R

2009-02-01

Skewed sex ratios - operational (OSR) and Adult (ASR) - arise from sexual differences in reproductive behaviours and adult survival rates due to the cost of reproduction. However, skewed sex-ratio at birth, sex-biased dispersal and immigration, and sexual differences in juvenile mortality may also contribute. We present a framework to decompose the roles of demographic traits on sex ratios using perturbation analyses of two-sex matrix population models. Metrics of sensitivity are derived from analyses of sensitivity, elasticity, life-table response experiments and life stage simulation analyses, and applied to the stable stage distribution instead of lambda. We use these approaches to examine causes of male-biased sex ratios in two populations of green-rumped parrotlets (Forpus passerinus) in Venezuela. Female local juvenile survival contributed the most to the unbalanced OSR and ASR due to a female-biased dispersal rate, suggesting sexual differences in philopatry can influence sex ratios more strongly than the cost of reproduction.

Bladder Preservation for Localized Muscle-Invasive Bladder Cancer: The Survival Impact of Local Utilization Rates of Definitive Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozak, Kevin R.; Hamidi, Maryam; Manning, Matthew

2012-06-01

Purpose: This study examines the management and outcomes of muscle-invasive bladder cancer in the United States. Methods and Materials: Patients with muscle-invasive bladder cancer diagnosed between 1988 and 2006 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Patients were classified according to three mutually exclusive treatment categories based on the primary initial treatment: no local management, radiotherapy, or surgery. Overall survival was assessed with Kaplan-Meier analysis and Cox models based on multiple factors including treatment utilization patterns. Results: The study population consisted of 26,851 patients. Age, sex, race, tumor grade, histology, and geographic location were associated withmore » differences in treatment (all p < 0.01). Patients receiving definitive radiotherapy tended to be older and have less differentiated tumors than patients undergoing surgery (RT, median age 78 years old and 90.6% grade 3/4 tumors; surgery, median age 71 years old and 77.1% grade 3/4 tumors). No large shifts in treatment were seen over time, with most patients managed with surgical resection (86.3% for overall study population). Significant survival differences were observed according to initial treatment: median survival, 14 months with no definitive local treatment; 17 months with radiotherapy; and 43 months for surgery. On multivariate analysis, differences in local utilization rates of definitive radiotherapy did not demonstrate a significant effect on overall survival (hazard ratio, 1.002; 95% confidence interval, 0.999-1.005). Conclusions: Multiple factors influence the initial treatment strategy for muscle-invasive bladder cancer, but definitive radiotherapy continues to be used infrequently. Although patients who undergo surgery fare better, a multivariable model that accounted for patient and tumor characteristics found no survival detriment to the utilization of definitive radiotherapy. These results support continued research into bladder preservation strategies and suggest that definitive radiotherapy represents a viable initial treatment strategy for those who wish to attempt to preserve their native bladder.« less

A Laboratory Maintenance Regime for a Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

PubMed

Lee, Ching-Chen; Lee, Chow-Yang

2015-06-01

The optimum maintenance conditions of the fungus-growing termite, Macrotermes gilvus (Hagen) (Blattodea: Termitidae), in the laboratory were studied. Termites were kept on a matrix of moist sand and with fungus comb as food. The survival of groups of termites was measured when maintained at different population densities by changing group size and container volume. Larger groups (≥0.6 g) were more vigorous and had significant higher survival rates than smaller groups (≤0.3 g). The population density for optimal survival of M. gilvus is 0.0025 g per container volume (ml) or 0.0169 g per matrix volume (cm(3)), i.e., 1.2 g of termites kept in a 480-ml container filled with 71 cm3 of sand. In termite groups of smaller size (i.e., 0.3 g) or groups maintained in smaller container (i.e., 100 ml) the fungus comb was overgrown with Xylaria spp., and subsequently all termites died within the study period. The insufficient number of workers for regulating the growth of unwanted fungi other than Termitomyces spp. in the fungus comb is the most likely reason. Unlike some other mound-building termite species, M. gilvus showed satisfactory survival when maintained in non-nutritious matrix (i.e., sand). There was no significant difference in the survival rate between different colonies of M. gilvus (n=5), with survival in the range of 78.5-84.4% after 4 wk. Advances in the maintenance of Macrotermes will enable researchers to study with more biological relevance many aspects of the biology, behavior, and management of this species. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of Clinicopathologic Features and Survival of Histopathologically Amelanotic and Pigmented Melanomas: A Population-Based Study

PubMed Central

Thomas, Nancy E.; Kricker, Anne; Waxweiler, Weston T.; Dillon, Patrick M.; Busam, Klaus J.; From, Lynn; Groben, Pamela A.; Armstrong, Bruce K.; Anton-Culver, Hoda; Gruber, Stephen B.; Marrett, Loraine D.; Gallagher, Richard P.; Zanetti, Roberto; Rosso, Stefano; Dwyer, Terence; Venn, Alison; Kanetsky, Peter A.; Orlow, Drs. Irene; Paine, Susan; Ollila, David W.; Reiner, Anne S.; Luo, Li; Hao, Honglin; Frank, Jill S.; Begg, Colin B.; Berwick, Marianne

2014-01-01

Importance Previous studies have reported that histopathologically amelanotic melanoma is associated with poorer survival than pigmented melanoma; however, small numbers of amelanotic melanomas, selected populations, lack of centralized pathology review, or no adjustment for stage limit interpretation or generalization of results from prior studies. Objective To compare melanoma-specific survival between patients with histopathologically amelanotic and those with pigmented melanoma in a large international population-based study. Design Survival analysis with median follow-up of 7.6 years. Setting The Genes, Environment, and Melanoma study enrolled incident cases of melanoma diagnosed in 1998-2003 from international population-based cancer registries. Participants A total of 2,995 patients with 3,486 invasive primary melanomas centrally scored for histologic pigmentation. Main Outcomes and Measurements Clinicopathologic predictors and melanoma-specific survival of histologically amelanotic and pigmented melanoma were compared using generalized estimating equations and Cox regression models, respectively. Results Eight percent of melanomas (275 of 3,467) were histopathologically amelanotic. Female sex, nodular and unclassified or other histologic subtypes, increased Breslow thickness, presence of mitoses, severe solar elastosis, and lack of a co-existing nevus were independently associated with amelanotic melanoma (each P < .05). Amelanotic melanoma was generally of a higher American Joint Committee on Cancer (AJCC) tumor stage at diagnosis (P for trend <.001) than pigmented melanoma. Hazard of death from melanoma was higher for amelanotic than pigmented melanoma [hazard ratio (HR), 2.0; 95% confidence interval (CI), 1.4-3.0; P< .001], adjusted for age, sex anatomic site, and study design variables; but survival did not differ once AJCC tumor stage was also taken into account, (HR, 0.8; 95% CI, 0.5-1.2; P = .36). Conclusions and Relevance At the population level, survival after diagnosis of amelanotic melanoma is poorer than after pigmented melanoma because of its more advanced stage at diagnosis. It is probable that amelanotic melanomas present at more advanced tumor stages because they are difficult to diagnose. The association of amelanotic melanoma with presence of mitoses independently of Breslow thickness and other clinicopathologic characteristics suggests that amelanotic melanomas might also grow faster than pigmented melanomas. New strategies for early diagnosis and investigation of the biology of amelanotic melanoma are warranted. PMID:25162299

Determinants of emigration and their impact on survival during dispersal in fox and jackal populations

PubMed Central

Kapota, Dror; Dolev, Amit; Bino, Gilad; Yosha, Dotan; Guter, Amichai; King, Roni; Saltz, David

2016-01-01

Animals disperse in response to poor resource conditions as a strategy of escaping harsh competition and stress, but may also disperse under good resource conditions, as these provide better chances of surviving dispersal and gaining fitness benefits such as avoiding kin competition and inbreeding. Individual traits should mediate the effect of resources, yielding a complex condition-dependent dispersal response. We investigated how experimental food reductions in a food-rich environment around poultry-growing villages interact with individual-traits (age, gender, body-mass) in two sympatric canids, red foxes and golden jackals, to jointly affect emigration propensity and survival during dispersal. Sub-adult foxes emigrated more frequently from the food-rich habitat than from the pristine, food-limited habitat, while adult foxes showed the opposite trend. During dispersal, adults exhibited lower survival while sub-adults did not experience additional mortality costs. Although fox mortality rates increased in response to food reduction, dispersal remained unchanged, while jackals showed strong dispersal response in two of the three repetitions. Jackal survival under food reduction was lowest for the dispersing individuals. While resources are an important dispersal determinant, different age classes and species experience the same resource environment differently and consequently have different motivations, yielding different dispersal responses and consequences. PMID:27050564

Determinants of survival in patients receiving dialysis in Libya.

PubMed

Alashek, Wiam A; McIntyre, Christopher W; Taal, Maarten W

2013-04-01

Maintenance dialysis is associated with reduced survival when compared with the general population. In Libya, information about outcomes on dialysis is scarce. This study, therefore, aimed to provide the first comprehensive analysis of survival in Libyan dialysis patients. This prospective multicenter study included all patients in Libya who had been receiving dialysis for >90 days in June 2009. Sociodemographic and clinical data were collected upon enrollment and survival status after 1 year was determined. Two thousand two hundred seventy-three patients in 38 dialysis centers were followed up for 1 year. The majority were receiving hemodialysis (98.8%). Sixty-seven patients were censored due to renal transplantation, and 46 patients were lost to follow-up. Thus, 2159 patients were followed up for 1 year. Four hundred fifty-eight deaths occurred, (crude annual mortality rate of 21.2%). Of these, 31% were due to ischemic heart disease, 16% cerebrovascular accidents, and 16% due to infection. Annual mortality rate was 0% to 70% in different dialysis centers. Best survival was in age group 25 to 34 years. Binary logistic regression analysis identified age at onset of dialysis, physical dependency, diabetes, and predialysis urea as independent determinants of increased mortality. Patients receiving dialysis in Libya have a crude 1-year mortality rate similar to most developed countries, but the mean age of the dialysis population is much lower, and this outcome is thus relatively poor. As in most countries, cardiovascular disease and infection were the most common causes of death. Variation in mortality rates between different centers suggests that survival could be improved by promoting standardization of best practice. © 2012 The Authors. Hemodialysis International © 2012 International Society for Hemodialysis.

Post-transplant survival in idiopathic pulmonary fibrosis patients concurrently listed for single and double lung transplantation.

PubMed

Chauhan, Dhaval; Karanam, Ashwin B; Merlo, Aurelie; Tom Bozzay, P A; Zucker, Mark J; Seethamraju, Harish; Shariati, Nazly; Russo, Mark J

2016-05-01

Lung transplantation is a widely accepted treatment for patients with end-stage lung disease related to idiopathic pulmonary fibrosis (IPF). However, there are conflicting data on whether double lung transplant (DLT) or single lung transplant (SLT) is the superior therapy in these patients. The purpose of this study was to determine whether actuarial post-transplant graft survival among IPF patients concurrently listed for DLT and SLT is greater for recipients undergoing the former or the latter. The United Network for Organ Sharing provided de-identified patient-level data. Analysis included lung transplant candidates with IPF listed between January 1, 2001 and December 31, 2009 (n = 3,411). The study population included 1,001 (29.3%) lung transplant recipients concurrently listed for DLT and SLT, all ≥18 years of age. The primary outcome measure was actuarial post-transplant graft survival, expressed in years. Among the study population, 433 (43.26%) recipients underwent SLT and 568 (56.74%) recipients underwent DLT. The analysis included 2,722.5 years at risk, with median graft survival of 5.31 years. On univariate (p = 0.317) and multivariate (p = 0.415) regression analyses, there was no difference in graft survival between DLT and SLT. Among IPF recipients concurrently listed for DLT and SLT, there is no statistical difference in actuarial graft survival between recipients undergoing DLT vs SLT. This analysis suggests that increased use of SLT for IPF patients may increase the availability of organs to other candidates, and thus increase the net benefit of these organs, without measurably compromising outcomes. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Evaluation of red cell distribution width in dogs with pulmonary hypertension.

PubMed

Swann, James W; Sudunagunta, Siddharth; Covey, Heather L; English, Kate; Hendricks, Anke; Connolly, David J

2014-12-01

To compare red cell distribution width (RDW) between dogs with different causes of pulmonary hypertension (PH) and a control dog population to determine whether RDW was correlated with severity of PH as measured by echocardiography. A further aim was to determine the prognostic significance of increased RDW for dogs with PH. Forty-four client-owned dogs with PH and 79 control dogs presented to a single tertiary referral institution. Signalment, clinical pathological and echocardiographic data were obtained retrospectively from the medical records of dogs with PH, and RDW measured on a Cell-Dyn 3500 was compared between dogs with pre- and post-capillary PH and a control population. Referring veterinary surgeons were contacted for follow-up information and Kaplan-Meier analysis was conducted to investigate differences in survival time between affected dogs with different RDW values. The RDW was significantly greater in dogs with pre-capillary PH compared to control dogs. There was no difference in median survival times between dogs with PH divided according to RDW values. The RDW was positively correlated with mean corpuscular volume and haematocrit in dogs with PH, but did not correlate with echocardiographic variables. An association was found between dogs with PH and increased RDW; however there was considerable overlap in values between control dogs and dogs with PH. The RDW was not associated with survival in this study. Copyright © 2014 Elsevier B.V. All rights reserved.

Critical Stages in the Recruitment Process of Rhamnus alaternus L.

PubMed Central

GULIAS, J.; TRAVESET, A.; RIERA, N.; MUS, M.

2004-01-01

• Background and Aims Rhamnus alaternus is a Mediterranean shrub commonly used in reforestation programs. Although several aspects of its reproductive biology have been studied, little is known about the importance of the different recruitment stages in the overall regeneration process of this species, which limits its proper use in Mediterranean forests and shrubland management. The aim of the present work was to quantify the importance of the different recruitment stages in the regeneration process of R. alaternus. • Methods Two populations of Rhamnus alaternus on the island of Mallorca that differ in climatic conditions, type of habitat and sex ratio were studied. The importance of seed production, seed dispersal and predation, seedling emergence and seedling survival for the regeneration of this species were quantified. • Key Results In both populations, fruit set and fruit removal by animals were not critical stages, since almost half of the flowers became mature fruits and 90 % of those were dispersed. Most seeds were deposited under female conspecifics (86 and 47 %, at Lloret and Esporles, respectively), and very few were found in open inter‐spaces (1 and 5 %). Post‐dispersal seed predation (mostly by ants and rodents) was very high in both populations. Seedling emergence took place during autumn and early winter and it ranged from 31 to 68 % depending upon year and microhabitat. The majority of emerged seedlings died during the first year, mainly due to desiccation; such mortality was influenced by rainfall and differed among microhabitats (varying from 67 to 100 %). The general spatial distribution of seed rain was concordant with the seedling emergence and survival pattern in both populations. • Conclusions The recruitment of Rhamnus alaternus appeared to be mainly limited by seed and seedling survival, regardless of the type of habitat in which the species is found. PMID:15150073

Environmental endocrinology of salmon smoltification

USGS Publications Warehouse

Bjornsson, Bjorn Thrandur; Stefansson, S.O.; McCormick, S.D.

2011-01-01

Smolting is a hormone-driven developmental process that is adaptive for downstream migration and ocean survival and growth in anadromous salmonids. Smolting includes increased salinity tolerance, increased metabolism, downstream migratory and schooling behavior, silvering and darkened fin margins, and olfactory imprinting. These changes are promoted by growth hormone, insulin-like growth factor I, cortisol, thyroid hormones, whereas prolactin is inhibitory. Photoperiod and temperature are critical environmental cues for smolt development, and their relative importance will be critical in determining responses to future climate change. Most of our knowledge of the environmental control and endocrine mediation of smolting is based on laboratory and hatchery studies, yet there is emerging information on fish in the wild that indicates substantial differences. Such differences may arise from differences in environmental stimuli in artificial rearing environments, and may be critical to ocean survival and population sustainability. Endocrine disruptors, acidification and other contaminants can perturb smolt development, resulting in poor survival after seawater entry. ?? 2010.

Kin and birth order effects on male child mortality: three East Asian populations, 1716-1945.

PubMed

Dong, Hao; Manfredini, Matteo; Kurosu, Satomi; Yang, Wenshan; Lee, James Z

2017-03-01

Human child survival depends on adult investment, typically from parents. However, in spite of recent research advances on kin influence and birth order effects on human infant and child mortality, studies that directly examine the interaction of kin context and birth order on sibling differences in child mortality are still rare. Our study supplements this literature with new findings from large-scale individual-level panel data for three East Asian historical populations from northeast China (1789-1909), northeast Japan (1716-1870), and north Taiwan (1906-1945), where preference for sons and first-borns is common. We examine and compare male child mortality risks by presence/absence of co-resident parents, grandparents, and other kin, as well as their interaction effects with birth order. We apply discrete-time event-history analysis on over 172,000 observations of 69,125 boys aged 1-9 years old. We find that in all three populations, while the presence of parents is important for child survival, it is more beneficial to first/early-borns than to later-borns. Effects of other co-resident kin are however null or inconsistent between populations. Our findings underscore the importance of birth order in understanding how differential parental investment may produce child survival differentials between siblings.

Effect of Orthene on an unconfined population of the meadow vole (Microtus pennsylvanicus)

USGS Publications Warehouse

Jett, David A.; Nichols, James D.; Hines, James E.

1986-01-01

The possible impact on Microtus pennsylvanicus of ground applications of Orthene® insecticide was investigated in old-field habitats in northern Maryland during 1982 and 1983. The treatment grids in 1982 and 1983 were sprayed at 0.62 and 0.82 kg active ingredient/ha, respectively. A capture–recapture design robust to unequal capture probabilities was utilized to estimate population size, survival, and recruitment. Data on reproductive activity and relative weight change were also collected to investigate the effect of the insecticide treatment. There were no significant differences in population size or recruitment between control and treatment grids which could be directly related to the treatment. Survival rate was significantly lower on the treatment grid than on the control grid after spraying in 1983; however, survival rate was higher on the treatment grid after spraying in 1982. Significantly fewer pregnant adults were found on the treatment grid after spraying in 1982, whereas the proportions of voles lactating or with perforate vaginas or open pubic symphyses were slightly higher or remained unchanged during this period. Relative weight change was not affected by the treatment. Results do not indicate any pattern of inhibitory effects from the insecticide treatment. Field application of Orthene® did not have an adverse effect on this Microtus population.

Estimating survival rates with time series of standing age‐structure data

USGS Publications Warehouse

Udevitz, Mark S.; Gogan, Peter J.

2012-01-01

It has long been recognized that age‐structure data contain useful information for assessing the status and dynamics of wildlife populations. For example, age‐specific survival rates can be estimated with just a single sample from the age distribution of a stable, stationary population. For a population that is not stable, age‐specific survival rates can be estimated using techniques such as inverse methods that combine time series of age‐structure data with other demographic data. However, estimation of survival rates using these methods typically requires numerical optimization, a relatively long time series of data, and smoothing or other constraints to provide useful estimates. We developed general models for possibly unstable populations that combine time series of age‐structure data with other demographic data to provide explicit maximum likelihood estimators of age‐specific survival rates with as few as two years of data. As an example, we applied these methods to estimate survival rates for female bison (Bison bison) in Yellowstone National Park, USA. This approach provides a simple tool for monitoring survival rates based on age‐structure data.

A review of the factors affecting the survival of donkeys in semi-arid regions of sub-Saharan Africa.

PubMed

Smith, D G; Pearson, R A

2005-11-01

The large fluctuations seen in cattle populations during periods of drought in sub-Saharan Africa are not evident in the donkey population. Donkeys appear to have a survival advantage over cattle that is increasingly recognized by smallholder farmers in their selection of working animals. The donkey's survival advantages arise from both socioeconomic and biological factors. Socioeconomic factors include the maintenance of a low sustainable population of donkeys owing to their single-purpose role and their low social status. Also, because donkeys are not usually used as a meat animal and can provide a regular income as a working animal, they are not slaughtered in response to drought, as are cattle. Donkeys have a range of physiological and behavioural adaptations that individually provide small survival advantages over cattle but collectively may make a large difference to whether or not they survive drought. Donkeys have lower maintenance costs as a result of their size and spend less energy while foraging for food; lower energy costs result in a lower dry matter intake (DMI) requirement. In donkeys, low-quality diets are digested almost as efficiently as in ruminants and, because of a highly selective feeding strategy, the quality of diet obtained by donkeys in a given pasture is higher than that obtained by cattle. Lower energy costs of walking, longer foraging times per day and ability to tolerate thirst may allow donkeys to access more remote, under-utilized sources of forage that are inaccessible to cattle on rangeland. As donkeys become a more popular choice of working animal for farmers, specific management practices need to be devised that allow donkeys to fully maximize their natural survival advantages.

Treatment patterns and cost-effectiveness of first line treatment of advanced non-squamous non-small cell lung cancer in Medicare patients.

PubMed

Gilden, Daniel M; Kubisiak, Joanna M; Pohl, Gerhardt M; Ball, Daniel E; Gilden, David E; John, William J; Wetmore, Stewart; Winfree, Katherine B

2017-02-01

To assess the cost-effectiveness of first-line pemetrexed/platinum and other commonly administered regimens in a representative US elderly population with advanced non-squamous non-small cell lung cancer (NSCLC). This study utilized the Surveillance Epidemiology and End Results (SEER) cancer registry linked to Medicare claims records. The study population included all SEER-Medicare patients diagnosed in 2008-2009 with advanced non-squamous NSCLC (stages IIIB-IV) as their only primary cancer and who started chemotherapy within 90 days of diagnosis. The study evaluated the four most commonly observed first-line regimens: paclitaxel/carboplatin, platinum monotherapy, pemetrexed/platinum, and paclitaxel/carboplatin/bevacizumab. Overall survival and total healthcare cost comparisons as well as incremental cost-effectiveness ratios (ICERs) were calculated for pemetrexed/platinum vs each of the other three. Unstratified analyses and analyses stratified by initial disease stage were conducted. The final study population consisted of 2,461 patients. Greater administrative censorship of pemetrexed recipients at the end of the study period disproportionately reduced the observed mean survival for pemetrexed/platinum recipients. The disease stage-stratified ICER analysis found that the pemetrexed/platinum incurred total Medicare costs of $536,424 and $283,560 per observed additional year of life relative to platinum monotherapy and paclitaxel/carboplatin, respectively. The pemetrexed/platinum vs triplet comparator analysis indicated that pemetrexed/platinum was associated with considerably lower total Medicare costs, with no appreciable survival difference. Limitations included differential censorship of the study regimen recipients and differential administration of radiotherapy. Pemetrexed/platinum yielded either improved survival at increased cost or similar survival at reduced cost relative to comparator regimens in the treatment of advanced non-squamous NSCLC. Limitations in the study methodology suggest that the observed pemetrexed survival benefit was likely conservative.

Spatial Variation and Survival of Salmonella enterica Subspecies in a Population of Australian Sleepy Lizards (Tiliqua rugosa).

PubMed

Parsons, Sandra K; Bull, C Michael; Gordon, David M

2015-09-01

The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations. This study examined the distribution of four Salmonella enterica subspecies in a population of sleepy lizards, Tiliqua rugosa, in a semiarid region of South Australia. The lizards living within the 1,920-m by 720-m study site were radio tracked, and their enteric bacteria were sampled at regular intervals throughout their active seasons in the years 2001, 2002, and 2006. Four of the six subspecies of S. enterica were present in this population and were nonrandomly distributed among the lizards. In particular, S. enterica subsp. diarizonae was restricted to lizards living in the most shaded parts of the study site with an overstorey of Casuarina trees. Experiments undertaken to investigate the survival of S. enterica cells under seminatural conditions revealed that cell survival decreased with increased exposure to elevated temperatures and UV light. Among the three S. enterica subspecies tested, S. enterica subsp. diarizonae consistently had an average expected life span that was shorter than that observed for the other two subspecies. There was no indication in the data that there was any competitive dominance hierarchy among the S. enterica subspecies within individual hosts. Thus, the nonrandom distribution of S. enterica subspecies in this population of lizards appears to be driven by their different survival characteristics in the external environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size

PubMed Central

King, Richard B.

2016-01-01

Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females) and annual growth increments of individuals of unknown age (1,152 males, 730 females). We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631–820 mm snout-vent length in males and from 835–1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further investigation. PMID:26730712

Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size.

PubMed

King, Richard B; Stanford, Kristin M; Jones, Peter C; Bekker, Kent

2016-01-01

Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females) and annual growth increments of individuals of unknown age (1,152 males, 730 females). We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631-820 mm snout-vent length in males and from 835-1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further investigation.

Spatial Variation and Survival of Salmonella enterica Subspecies in a Population of Australian Sleepy Lizards (Tiliqua rugosa)

PubMed Central

Parsons, Sandra K.; Bull, C. Michael

2015-01-01

The life cycles of many enteric bacterial species require a transition between two very distinct environments. Their primary habitat is the gastrointestinal tract of the host, while their secondary habitat, during transmission from one host to another, consists of environments external to the host, such as soil, water, and sediments. Consequently, both host and environmental factors shape the genetic structure of enteric bacterial populations. This study examined the distribution of four Salmonella enterica subspecies in a population of sleepy lizards, Tiliqua rugosa, in a semiarid region of South Australia. The lizards living within the 1,920-m by 720-m study site were radio tracked, and their enteric bacteria were sampled at regular intervals throughout their active seasons in the years 2001, 2002, and 2006. Four of the six subspecies of S. enterica were present in this population and were nonrandomly distributed among the lizards. In particular, S. enterica subsp. diarizonae was restricted to lizards living in the most shaded parts of the study site with an overstorey of Casuarina trees. Experiments undertaken to investigate the survival of S. enterica cells under seminatural conditions revealed that cell survival decreased with increased exposure to elevated temperatures and UV light. Among the three S. enterica subspecies tested, S. enterica subsp. diarizonae consistently had an average expected life span that was shorter than that observed for the other two subspecies. There was no indication in the data that there was any competitive dominance hierarchy among the S. enterica subspecies within individual hosts. Thus, the nonrandom distribution of S. enterica subspecies in this population of lizards appears to be driven by their different survival characteristics in the external environment. PMID:26092451

Field-based estimates of avian mortality from West Nile virus infection.

PubMed

Ward, Michael P; Beveroth, Tara A; Lampman, Richard; Raim, Arlo; Enstrom, David; Novak, Robert

2010-11-01

One of the unique characteristics of West Nile virus (WNV) in North America is the large number of bird species for which the virus can be fatal. WNV mortality has been documented through experimental infections of captive birds and necropsies of free-ranging birds. Investigations of WNV-related mortality in wild birds often focus on species with dramatic population declines (e.g., American Crow, Corvus brachyrhynchos); however, few studies have addressed WNV-related mortality in species not exhibiting marked population declines since the arrival of WNV. We conducted a mark-recapture study of 204 Northern Cardinals (Cardinalis cardinalis) in an area with endemic WNV activity to estimate WNV-related mortality. Previous research has shown that once a bird is infected and recovers from WNV it develops antibodies making it resistant to future infection. Assuming that mortality risks from non-WNV causes were the same for individuals with (had been exposed to WNV) and without antibodies (had not been exposed to WNV), we compared the survival rates of birds with and without WNV antibodies to estimate the impact of WNV on wild birds. An information theoretic approach was used, and the apparent survival was found to be 34.6% lower for individuals without antibodies during the period when WNV was most active (July-September). However, the apparent survival rate was 9.0% higher for individuals without antibodies over the rest of the year. These differences in apparent survival suggest that WNV increases mortality during the WNV season and that chronic effects of WNV infection may also be contributing to mortality. Although WNV appears to have increased mortality rates within the population, population trend data do not indicate declines, suggesting that some cardinal populations can compensate for WNV-related mortality.

Effects of NaCl stress on seed germination and seedling development of Brassica insularis Moris (Brassicaceae).

PubMed

Santo, A; Mattana, E; Frigau, L; Marzo Pastor, A; Picher Morelló, M C; Bacchetta, G

2017-05-01

Brassica insularis is a protected plant that grows on both coastal and inland cliffs in the western Mediterranean Basin. The objective of this study was to test if any variability exists in the salt stress response during seed germination and seedling development in this species relative to its provenance habitat. Variability among three populations in the salt stress effects on seed germination and recovery under different temperatures was evaluated. The effect of nebulisation of a salt solution on seedling development was evaluated between populations growing at different distances from the sea. Seeds of B. insularis could germinate at NaCl concentrations up to 200 mm. Seed viability was negatively affected by salt, and recovery ability decreased with increasing temperature or salinity. Inter-population variability was detected in salt response during the seed germination phase, as well as in seedling salt spray tolerance. The inland population seedlings had drastically decreased survival and life span and failed to survive to the end of the experiment. In contrast, at least 90% of the coastal seedlings survived, even when sprayed at the highest frequency with salt solution. This study allowed investigation of two natural factors, soil salinity and marine aerosols, widely present in the B. insularis habitat, and provided the first insights into ecology of this protected species and its distribution in the Mediterranean. These results might be useful in understanding the actual distributions of other species with the same ecology that experience these same abiotic parameters. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

A case of low success of blind vaccination campaigns against myxomatosis and rabbit haemorrhagic disease on survival of adult European wild rabbits.

PubMed

Rouco, Carlos; Moreno, Sacramento; Santoro, Simone

2016-10-01

Vaccination campaigns against myxomatosis and rabbit haemorrhagic disease (RHD) are commonly used in translocation programs conducted for the purpose of recovering wild European rabbit populations in Iberian Mediterranean ecosystems. In most cases rabbits are vaccinated 'blind' (i.e. without assessing their prior immunological status) for economic and logistic reasons. However, there is conflicting evidence on the effectiveness of such an approach. We tested whether blind vaccination against myxomatosis and rabbit haemorrhagic disease improved rabbit survival in a rabbit translocation program where wild rabbits were kept in semi-natural conditions in three enclosures. We conducted nine capture sessions over two years (2008-2010) and used the information collected to compare the survival of vaccinated (n=511) versus unvaccinated (n=161) adult wild rabbits using capture-mark-recapture analysis. Average monthly survival was no different for vaccinated versus unvaccinated individuals, both in the period between release and first capture (short-term) and after the first capture onward (long-term). Rabbit survival was lower in the short term than in the long term regardless of whether rabbits were vaccinated or not. Lower survival in the short-term could be due to the stress induced by the translocation process itself (e.g. handling stress). However, we did not find any overall effect of vaccination on survival which could be explained by two non-exclusive reasons. First, interference of the vaccine with the natural antibodies in the donor population. Due to donor populations have high density of rabbits with, likely, high prevalence of antibodies as a result of previous natural exposure to these diseases. Second, the lack of severe outbreaks during the study period. Based on our findings we argue that blind vaccination of adult rabbits in translocation programs may be often mostly ineffective and unnecessarily costly. In particular, since outbreaks are hard to predict and vaccination of rabbits with natural antibodies is ineffective, it is crucial to assess the immunological status of the donor population before translocating adult rabbits. Copyright © 2016 Elsevier B.V. All rights reserved.

Incidence and survival for Merkel cell carcinoma in Queensland, Australia, 1993-2010.

PubMed

Youlden, Danny R; Soyer, H Peter; Youl, Philippa H; Fritschi, Lin; Baade, Peter D

2014-08-01

Merkel cell carcinoma (MCC) is an uncommon but highly invasive form of skin cancer. The mechanisms that cause MCC are yet to be fully determined. To compare the incidence and survival rates of MCC in Queensland, Australia, known to be a high-risk area, with MCC incidence and survival elsewhere in the world. We also analyzed incidence trends and differences in survival by key demographic and clinical characteristics. Retrospective cohort study of population-based administrative data for MCC collected by the Queensland Cancer Registry and supplemented with detailed histopathologic data. Deidentified records were obtained of all Queensland residents diagnosed as having MCC during the period from 1993 to 2010. A subsample of histopathologic records were reviewed by a senior dermatopathologist to determine the potential for misclassification. A total of 879 eligible cases of MCC were included in the study. Incidence rates were directly age standardized to the 2000 United States Standard Population. Trends were examined using Joinpoint software with results expressed in terms of the annual percentage change. The period method was used to calculate 5-year relative survival, and adjusted hazard ratios were obtained from multivariate Poisson models. There were 340 cases of MCC diagnosed in Queensland between 2006 and 2010, corresponding to an incidence rate of 1.6 per 100,000 population. Men (2.5 per 100,000) had higher incidence than women (0.9 per 100,000), and rates peaked at 20.7 per 100,000 for persons 80 years or older. The overall incidence of MCC increased by an average of 2.6% per year from 1993 onwards. Relative survival was 41% after 5 years, with significantly better survival found for those younger than 70 years at diagnosis (56%-60%), those with tumors on the face or ears (51%), and those with stage I lesions (49%). Incidence rates for MCC in Queensland are at least double those of any that have been previously published elsewhere in the world. It is likely that Queensland's combination of a predominantly white population, outdoor lifestyle, and exposure to sunlight has played a role in this unwanted result. Interventions are required to increase awareness of MCC among clinicians and the public.

Breast cancer survival rates among Seventh-day Adventists and non-Seventh-day Adventists.

PubMed

Zollinger, T W; Phillips, R L; Kuzma, J W

1984-04-01

Survival rates were compared among 282 Seventh-day Adventists and 1675 other white female cancer cases following diagnosis during the 30-year period, 1946 to 1976, at two California hospitals owned and operated by the Seventh-day Adventist Church. The Adventist women had a more favorable 5-year relative survival pattern than the other women (69.7% vs. 62.9%) as well as a higher probability of not dying of breast cancer. The differences, however, were no longer significant when stage at diagnosis was taken into account. It seems likely that the lower breast cancer death rates reported among Seventh-day Adventist women as compared with the general population result in part from better survival patterns due to earlier diagnosis and treatment.

Trends in survival of chronic lymphocytic leukemia patients in Germany and the USA in the first decade of the twenty-first century.

PubMed

Pulte, Dianne; Castro, Felipe A; Jansen, Lina; Luttmann, Sabine; Holleczek, Bernd; Nennecke, Alice; Ressing, Meike; Katalinic, Alexander; Brenner, Hermann

2016-03-22

Recent population-based studies in the United States of America (USA) and other countries have shown improvements in survival for patients with chronic lymphocytic leukemia (CLL) diagnosed in the early twenty-first century. Here, we examine the survival for patients diagnosed with CLL in Germany in 1997-2011. Data were extracted from 12 cancer registries in Germany and compared to the data from the USA. Period analysis was used to estimate 5- and 10-year relative survival (RS). Five- and 10-year RS estimates in 2009-2011 of 80.2 and 59.5%, respectively, in Germany and 82.4 and 64.7%, respectively, in the USA were observed. Overall, 5-year RS increased significantly in Germany and the difference compared to the survival in the USA which slightly decreased between 2003-2005 and 2009-2011. However, age-specific analyses showed persistently higher survival for all ages except for 15-44 in the USA. In general, survival decreased with age, but the age-related disparity was small for patients younger than 75. In both countries, 5-year RS was >80% for patients less than 75 years of age but <70% for those age 75+. Overall, 5-year survival for patients with CLL is good, but 10-year survival is significantly lower, and survival was much lower for those age 75+. Major differences in survival between countries were not observed. Further research into ways to increase survival for older CLL patients are needed to reduce the persistent large age-related survival disparity.

Male breast cancer: a nation-wide population-based comparison with female breast cancer.

PubMed

Lautrup, Marianne D; Thorup, Signe S; Jensen, Vibeke; Bokmand, Susanne; Haugaard, Karen; Hoejris, Inger; Jylling, Anne-Marie B; Joernsgaard, Hjoerdis; Lelkaitis, Giedrius; Oldenburg, Mette H; Qvamme, Gro M; Soee, Katrine; Christiansen, Peer

2018-05-01

Describe prognostic parameters of Danish male breast cancer patients (MBCP) diagnosed from 1980-2009. Determine all-cause mortality compared to the general male population and analyze survival/mortality compared with Danish female breast cancer patients (FBCP) in the same period. The MBCP cohort was defined from three national registers. Data was extracted from medical journals. Data for FBCP is from the DBCG database. Overall survival (OS) was quantified by Kaplan-Meier estimates. Standardized mortality ratios (SMRs) were calculated based on mortality rate among patients relative to the mortality rate in the general population. The association between SMR and risk factors were analyzed in univariate and multivariable Poisson regression models. Separate models for each gender were used for the analyses. We found a marked difference in OS for the two genders. For the total population of MBCP, 5- and 10-year survivals were 55.1% and 31.7%, respectively. For FBCP, the corresponding figures were 76.8% and 59.3%. Median age at diagnosis for FBCP was 61 years and 70 years for MBCP. By applying SMR, the difference in mortality between genders equalized and showed pronounced age-dependency. For males <40 years, SMR was 9.43 and for females 19.56 compared to SMR for males 80 + years (0.95) and females 80 + years (0.89). During the period 1980-2009, the risk of dying gradually decreased for FBCP (p < .0001). The risk 1980-1984 was 35% higher than 2005-2009 (RR 1.35). Although the risk of dying for MBCP was also lowest in 2005-2009, there was no clear tendency (p = .1439). The risk was highest in 1990-1994 (RR =2.48). We found better OS for FBCP than for MBCP. But SMR showed similar mortality rate for the two genders, except for very young FBCP, who had higher SMR. Furthermore, significantly improved survival over time for FBCP was observed, with no clear tendency for MBCP.

Efficacy of ultraviolet light exposure against survival of Listeria monocytogenes on conveyor belts.

PubMed

Morey, Amit; McKee, Shelly R; Dickson, James S; Singh, Manpreet

2010-06-01

Listeria monocytogenes has been repeatedly isolated from foods and food-processing facilities including food contact surfaces such as conveyor belts (CB). CBs are often difficult to clean and require rigorous sanitation programs for decontamination. Ultraviolet (UV) light has exhibited microbicidal properties on food contact surfaces and this study was conducted to determine the efficacy of UV against L. monocytogenes on CB made of different materials. A four-strain cocktail of L. monocytogenes (serotypes 3A, 4A, 4B, and 4C) was made to give a suspension of approximately 10(7) CFU/mL. CBs made from four different types of materials, (1) Ropanyl DM 8/2 A2 + 04 (belt 1), (2) Volta FRMW-3.0 (belt 2), (3) Volta FRMB-3.0 (belt 3), and (4) Ropanyl DM (belt 4), were inoculated with 1 mL of the four-strain cocktail (approximately 10(7) CFU/mL) of the bacterial suspension. CBs were treated with UV light (254 nm) for 1 and 3 sec at 5.53 and 5.95 mW/cm(2). Three replications of the experiments were conducted. Two-way analysis of variance of survival populations of L. monocytogenes showed that bacterial counts were significantly reduced (p < 0.05) on all belt types irrespective of UV light intensities and times of exposure. L. monocytogenes populations were reduced (p < 0.05) to below detection limits on belts 1, 2, and 3 after exposure to 5.95 mW/cm(2) UV light intensity for 3 sec. L. monocytogenes-inoculated CBs that were exposed to 5.53 mW/cm(2) showed higher (p < 0.05) survival populations of L. monocytogenes compared with 5.95 mW/cm(2) on all the four CBs. Belt 4 showed survival populations of L. monocytogenes ranging from 1.42 to 1.73 log(10) CFU/cm(2) after UV light treatment for 1 and 3 sec. UV light can be effectively used to reduce L. monocytogenes contamination on CBs.

DGKI methylation status modulates the prognostic value of MGMT in glioblastoma patients treated with combined radio-chemotherapy with temozolomide.

PubMed

Etcheverry, Amandine; Aubry, Marc; Idbaih, Ahmed; Vauleon, Elodie; Marie, Yannick; Menei, Philippe; Boniface, Rachel; Figarella-Branger, Dominique; Karayan-Tapon, Lucie; Quillien, Veronique; Sanson, Marc; de Tayrac, Marie; Delattre, Jean-Yves; Mosser, Jean

2014-01-01

Consistently reported prognostic factors for glioblastoma (GBM) are age, extent of surgery, performance status, IDH1 mutational status, and MGMT promoter methylation status. We aimed to integrate biological and clinical prognostic factors into a nomogram intended to predict the survival time of an individual GBM patient treated with a standard regimen. In a previous study we showed that the methylation status of the DGKI promoter identified patients with MGMT-methylated tumors that responded poorly to the standard regimen. We further evaluated the potential prognostic value of DGKI methylation status. 399 patients with newly diagnosed GBM and treated with a standard regimen were retrospectively included in this study. Survival modelling was performed on two patient populations: intention-to-treat population of all included patients (population 1) and MGMT-methylated patients (population 2). Cox proportional hazard models were fitted to identify the main prognostic factors. A nomogram was developed for population 1. The prognostic value of DGKI promoter methylation status was evaluated on population 1 and population 2. The nomogram-based stratification of the cohort identified two risk groups (high/low) with significantly different median survival. We validated the prognostic value of DGKI methylation status for MGMT-methylated patients. We also demonstrated that the DGKI methylation status identified 22% of poorly responding patients in the low-risk group defined by the nomogram. Our results improve the conventional MGMT stratification of GBM patients receiving standard treatment. These results could help the interpretation of published or ongoing clinical trial outcomes and refine patient recruitment in the future.

Atrial fibrillation among African Americans, Hispanics and Caucasians: clinical features and outcomes from the AFFIRM trial.

PubMed

Bush, David; Martin, Lisa W; Leman, Robert; Chandler, Mary; Haywood, L Julian

2006-03-01

The Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) study concluded that rate control with anticoagulation was equivalent overall to rhythm control with cardioversion for long-term survival and that anticoagulation reduced the risk of stroke. We compared baseline and follow-up data for three ethnic groups: Caucasians (n=3,599), African Americans (n=265) and Hispanics (n=132). Caucasians were older and more likely male, African Americans were more likely female and hypertensive, and Hispanics had higher prevalence of cardiomyopathy. Survival was better for rate control than rhythm control in Caucasians, equivalent in African Americans and better for rhythm control in Hispanics. Outcomes may be influenced by differential baseline characteristics, but low numbers of African Americans and Hispanics warrant caution in data interpretation. The AFFIRM study compared a rate-control strategy to a rhythm-control strategy for the treatment of atrial fibrillation (AF) in patients at high risk for stroke or death. It concluded that the rhythm-control strategy offered no survival advantage, and it also confirmed the value of anticoagulation to prevent complications of AF. Data have not previously been available for specific racial ethnic populations. We compared baseline and follow-up data for the patients randomized to rate-control versus rhythm-control in three population groups-Caucasian, African-American and Hispanic. Among 4,060 total patients, 3,599 were Caucasian, 265 were African-American and 132 were Hispanic. At baseline, Caucasians were older and had a higher percentage of males, normal ejection fractions, AF as their only cardiac diagnosis, a prior antiarrhythmic drug failure and less congestive heart failure. African Americans were more likely to be female, had more hypertension and qualified for the study with a first episode of AF, compared to Caucasians. Hispanics had more cardiomyopathy at baseline than Caucasians. Overall survival in Caucasians at five years for the rate-control and rhythm-control groups was 78.9% vs. 76.4%, respectively (p=0.04); for African Americans, 79.0% vs. 69.4% (p=0.22); and for Hispanics, 66.5% vs. 83.9% (p=0.01). Overall, survival was not different between the three populations. However, lower rates of event-free survival were recorded for Hispanics and for African Americans (p=0.0182). Different survival rates were found for rate-control versus rhythm-control in African-American and Hispanic patients, compared to Caucasian. These findings may be influenced by differences in baseline characteristics, but must be interpreted with caution because of the small sample sizes for African-American and Hispanic participants.

Demographic outcomes of diverse migration strategies assessed in a metapopulation of tundra swans.

PubMed

Ely, Craig R; Meixell, Brandt W

2016-01-01

Migration is a prominent aspect of the life history of many avian species, but the demographic consequences of variable migration strategies have only infrequently been investigated, and rarely when using modern technological and analytical methods for assessing survival, movement patterns, and long-term productivity in the context of life history theory. We monitored the fates of 50 satellite-implanted tundra swans (Cygnus columbianus) over 4 years from five disparate breeding areas in Alaska, and used known-fate analyses to estimate monthly survival probability relative to migration distance, breeding area, migratory flyway, breeding status, and age. We specifically tested whether migratory birds face a trade-off, whereby long-distance migrants realize higher survival rates at the cost of lower productivity because of reduced time on breeding areas relative to birds that migrate shorter distances and spend more time on breeding areas. Annual migration distances varied significantly among breeding areas (1020 to 12720 km), and were strongly negatively correlated with time spent on breeding areas (r = -0.986). Estimates of annual survival probability varied by wintering area (Pacific coast, Alaska Peninsula, and Eastern seaboard) and ranged from 0.79 (95%CI: 0.70-0.88) to 1.0, depending on criteria used to discern mortalities from radio failures. We did not find evidence for a linear relationship between migration distance and survival as swans from the breeding areas with the shortest and longest migration distances had the highest survival probabilities. Survival was lower in the first year post-marking than in subsequent years, but there was not support for seasonal differences in survival. Productivity varied among breeding populations and was generally inversely correlated to survival, but not migration distance or time spent on breeding areas. Tundra swans conformed to a major tenet of life history theory, as populations with the highest survival generally had the lowest productivity. The lack of a uniform relationship between time spent on breeding areas and productivity, or time spent on wintering areas and survival, indicates that factors other than temporal investment dictate demographic outcomes in this species. The tremendous diversity of migration strategies we identify in Alaskan tundra swans, without clear impacts on survival, underscores the ability of this species to adapt to different environments and climatic regimes.

Differential impacts of wildfire on the population dynamics of an old-forest species.

PubMed

Rockweit, Jeremy T; Franklin, Alan B; Carlson, Peter C

2017-06-01

Ecological disturbances shape and maintain natural communities, but climate change and human land use can alter disturbance regimes and affect population persistence and vital rates in unpredictable ways. Species inhabiting landscapes shaped by wildfire have evolved mechanisms allowing them to persist under this dynamic disturbance type, which creates habitats of varying quality for these species. We utilized data from a 26-yr demographic study of northern spotted owls to analyze the influence of wildfire on apparent survival and recruitment rates. Wildfires occurred across different years and affected different spotted owl territories, which allowed us to implement a retrospective Before-After-Control-Impact (BACI) analysis and model the potential effect of wildfire extent and severity. Our results indicated that mixed-severity fires that burned at predominantly low-severity had little effect on survival and recruitment while fires characterized by more medium to high burn severities negatively affected spotted owl survival, with varying effects on recruitment. Reduced survival and increased recruitment rates on some territories affected by medium to high severity fires suggested that post-fire habitat quality was reduced resulting in territories that were marginally capable of supporting owls. We hypothesize these territories may have represented "sinks" that were supported by nearby "source" territories in a spatially heterogeneous landscape created by the mixed-severity fire regime of the region. © 2017 by the Ecological Society of America.

Swift fox survival and production in southeastern Wyoming

USGS Publications Warehouse

Olson, Travis L.; Lindzey, Frederick G.

2002-01-01

We estimated annual survival rates of swift foxes (Vulpes velox) and documented number of young per pair in a transition zone between shortgrass prairie and sagebrush steppe plant communities in southeastern Wyoming during 1996-2000. Annual adult survival ranged from 40% to 69%, with predation by coyotes (Canis latrans) the primary cause of deaths. Two foxes died of canine distemper virus. Annual survival rates did not differ among years (P>0.12). Nineteen of 24 (79%) swift fox pairs were observed with young over 3 years. Mean minimum litter size was 4.6 based on these 19 litters and 6 others not associated with our radiocollared foxes. Adult survival was similar and litter size slightly larger than observed elsewhere in the species range, suggesting that viable swift fox populations can be supported by sagebrush steppe and shortgrass prairie transition habitat.

Population dynamics of king eiders breeding in northern Alaska

USGS Publications Warehouse

Bentzen, Rebecca L.; Powell, Abby N.

2012-01-01

The North American population of king eiders (Somateria spectabilis) has declined by more than 50% since the late 1970s for unknown reasons. King eiders spend most of their lives in remote areas, forcing managers to make regulatory and conservation decisions based on very little information. We incorporated available published estimates of vital rates with new estimates to build a female, stage-based matrix population model for king eiders and examine the processes underlying population dynamics of king eiders breeding at 2 sites, Teshekpuk and Kuparuk, on the coastal plain of northern Alaska and wintering around the Bering Sea (2001–2010). We predicted a decreasing population (λ = 0.981, 95% CI: 0.978–0.985), and that population growth was most sensitive to changes in adult female survival (sensitivity = 0.92). Low duckling survival may be a bottleneck to productivity (variation in ducking survival accounted for 66% of retrospective variation in λ). Adult survival was high (0.94) and invariant (σ = 0.0002, 95% CI: 0.0000–0.0007); however, catastrophic events could have a major impact and we need to consider how to mitigate and manage threats to adult survival. A hypothetical oil spill affecting breeding females in a primary spring staging area resulted in a severe population decline; although, transient population dynamics were relatively stable. However, if no catastrophic events occur, the more variable reproductive parameters (duckling and nest survival) may be more responsive to management actions.

No evidence for increased performance of a specialist psyllid on invasive French broom

NASA Astrophysics Data System (ADS)

Herrera, Angelica M.; Carruthers, Raymond I.; Mills, Nicholas J.

2011-03-01

Some invasive plants perform better in their area of introduction than in their native region. This may be a consequence of rapid evolutionary change due to different selection pressures encountered in introduced regions. The Evolution of Increased Competitive Ability hypothesis (EICA) suggests that release from natural enemies results in selection of more vigorous plant genotypes as a result of plants allocating resources away from costly herbivore-resistance traits and toward increased growth. We tested the prediction that introduced plant genotypes of Genista monspessulana (Fabaceae) are less resistant to herbivory by a specialist psyllid, Arytinnis hakani (Hemiptera: Psyllidae) by measuring and comparing A. hakani performance on plants from native (southern France) and introduced (California, U.S.) populations. A. hakani performed equally well on plants from the native and introduced regions; there were no significant differences in psyllid egg and nymphal development, nymphal survival rates, female longevity or fecundity between the test plants. Egg survival rates were significantly higher on native populations, but the difference was minimal. These results provide preliminary evidence that native and introduced G. monspessulana populations are equally resistant to A. hakani and do not support the EICA hypothesis prediction of reduced investment in defense in introduced plant populations. Possible explanations for the lack of effects found in this study include the type of parameters measured and the feeding ecology of the herbivore used to test EICA, and finally, that evolutionary changes in plant defense in introduced G. monspessulana populations may not have occurred.

Disparities in pediatric leukemia early survival in Argentina: a population-based study.

PubMed

Garibotti, Gilda; Moreno, Florencia; Dussel, Veronica; Orellana, Liliana

2014-10-01

To identify disparities-using recursive partitioning (RP)-in early survival for children with leukemias treated in Argentina, and to depict the main characteristics of the most vulnerable groups. This secondary data analysis evaluated 12-month survival (12-ms) in 3 987 children diagnosed between 2000 and 2008 with lymphoid leukemia (LL) and myeloid leukemia (ML) and registered in Argentina's population-based oncopediatric registry. Prognostic groups based on age at diagnosis, gender, socioeconomic index of the province of residence, and migration to a different province to receive health care were identified using the RP method. Overall 12-ms for LL and ML cases was 83.7% and 59.9% respectively. RP detected major gaps in 12-ms. Among 1-10-year-old LL patients from poorer provinces, 12-ms for those who did and did not migrate was 87.0% and 78.2% respectively. Survival of ML patients < 2 years old from provinces with a low/medium socioeconomic index was 38.9% compared to 62.1% for those in the same age group from richer provinces. For 2-14-year-old ML patients living in poor provinces, patient migration was associated with a 30% increase in 12-ms. Major disparities in leukemia survival among Argentine children were found. Patient migration and socioeconomic index of residence province were associated with survival. The RP method was instrumental in identifying and characterizing vulnerable groups.

Incidence, prevalence, and survival of chronic pancreatitis: a population-based study.

PubMed

Yadav, Dhiraj; Timmons, Lawrence; Benson, Joanne T; Dierkhising, Ross A; Chari, Suresh T

2011-12-01

Population-based data on chronic pancreatitis (CP) in the United States are scarce. We determined incidence, prevalence, and survival of CP in Olmsted County, MN. Using Mayo Clinic Rochester's Medical Diagnostic Index followed by a detailed chart review, we identified 106 incident CP cases from 1977 to 2006 (89 clinical cases, 17 diagnosed only at autopsy); CP was defined by previously published Mayo Clinic criteria. We calculated age- and sex-adjusted incidence (for each decade) and prevalence rate (1 January 2006) per 100,000 population (adjusted to 2000 US White population). We compared the observed survival rate for patients with expected survival for age- and sex-matched Minnesota White population. Median age at diagnosis of CP was 58 years, 56% were male, and 51% had alcoholic CP. The overall (clinical cases or diagnosed only at autopsy) age- and sex-adjusted incidence was 4.05/100,000 person-years (95% confidence interval (CI) 3.27-4.83). The incidence rate for clinical cases increased significantly from 2.94/100,000 during 1977-1986 to 4.35/100,000 person-years during 1997-2006 (P<0.05) because of an increase in the incidence of alcoholic CP. There were 51 prevalent CP cases on 1 January 2006 (57% male, 53% alcoholic). The age- and sex-adjusted prevalence rate per 100,000 population was 41.76 (95% CI 30.21-53.32). At last follow-up, 50 patients were alive. Survival among CP patients was significantly lower than age- and sex-specific expected survival in Minnesota White population (P<0.001). Incidence and prevalence of CP are low, and ∼50% are alcohol related. The incidence of CP cases diagnosed during life is increasing. Survival of CP patients is lower than in the Minnesota White population.

Estimates of annual survival, growth, and recruitment of a white-tailed ptarmigan population in Colorado over 43 years

USGS Publications Warehouse

Wann, Greg; Aldridge, Cameron L.; Braun, Clait E.

2014-01-01

Long-term datasets for high-elevation species are rare, and considerable uncertainty exists in understanding how high-elevation populations have responded to recent climate warming. We present estimates of demographic vital rates from a 43-year population study of white-tailed ptarmigan (Lagopus leucura), a species endemic to alpine habitats in western North America. We used capture-recapture models to estimate annual rates of apparent survival, population growth, and recruitment for breeding-age ptarmigan, and we fit winter weather covariates to models in an attempt to explain annual variation. There were no trends in survival over the study period but there was strong support for age and sex effects. The average rate of annual growth suggests a relatively stable breeding-age population ( λ ¯ = 1.036), but there was considerable variation between years for both population growth and recruitment rates. Winter weather covariates only explained a small amount of variation in female survival and were not an important predictor of male survival. Cumulative winter precipitation was found to have a quadratic effect on female survival, with survival being highest during years of average precipitation. Cumulative winter precipitation was positively correlated with population growth and recruitment rates, although this covariate only explained a small amount of annual variation in these rates and there was considerable uncertainty among the models tested. Our results provide evidence for an alpine-endemic population that has not experienced extirpation or drastic declines. However, more information is needed to understand risks and vulnerabilities of warming effects on juveniles as our analysis was confined to determination of vital rates for breeding-age birds.

Population-based cancer survival in the United States: Data, quality control, and statistical methods.

PubMed

Allemani, Claudia; Harewood, Rhea; Johnson, Christopher J; Carreira, Helena; Spika, Devon; Bonaventure, Audrey; Ward, Kevin; Weir, Hannah K; Coleman, Michel P

2017-12-15

Robust comparisons of population-based cancer survival estimates require tight adherence to the study protocol, standardized quality control, appropriate life tables of background mortality, and centralized analysis. The CONCORD program established worldwide surveillance of population-based cancer survival in 2015, analyzing individual data on 26 million patients (including 10 million US patients) diagnosed between 1995 and 2009 with 1 of 10 common malignancies. In this Cancer supplement, we analyzed data from 37 state cancer registries that participated in the second cycle of the CONCORD program (CONCORD-2), covering approximately 80% of the US population. Data quality checks were performed in 3 consecutive phases: protocol adherence, exclusions, and editorial checks. One-, 3-, and 5-year age-standardized net survival was estimated using the Pohar Perme estimator and state- and race-specific life tables of all-cause mortality for each year. The cohort approach was adopted for patients diagnosed between 2001 and 2003, and the complete approach for patients diagnosed between 2004 and 2009. Articles in this supplement report population coverage, data quality indicators, and age-standardized 5-year net survival by state, race, and stage at diagnosis. Examples of tables, bar charts, and funnel plots are provided in this article. Population-based cancer survival is a key measure of the overall effectiveness of services in providing equitable health care. The high quality of US cancer registry data, 80% population coverage, and use of an unbiased net survival estimator ensure that the survival trends reported in this supplement are robustly comparable by race and state. The results can be used by policymakers to identify and address inequities in cancer survival in each state and for the United States nationally. Cancer 2017;123:4982-93. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Survival Rate and Transcriptional Response upon Infection with the Generalist Parasite Beauveria bassiana in a World-Wide Sample of Drosophila melanogaster

PubMed Central

Paparazzo, Francesco; Tellier, Aurélien; Stephan, Wolfgang; Hutter, Stephan

2015-01-01

The ability to cope with infection by a parasite is one of the major challenges for any host species and is a major driver of evolution. Parasite pressure differs between habitats. It is thought to be higher in tropical regions compared to temporal ones. We infected Drosophila melanogaster from two tropical (Malaysia and Zimbabwe) and two temperate populations (the Netherlands and North Carolina) with the generalist entomopathogenic fungus Beauveria bassiana to examine if adaptation to local parasite pressures led to differences in resistance. Contrary to previous findings we observed increased survival in temperate populations. This, however, is not due to increased resistance to infection per se, but rather the consequence of a higher general vigor of the temperate populations. We also assessed transcriptional response to infection within these flies eight and 24 hours after infection. Only few genes were induced at the earlier time point, most of which are involved in detoxification. In contrast, we identified more than 4,000 genes that changed their expression state after 24 hours. This response was generally conserved over all populations with only few genes being uniquely regulated in the temperate populations. We furthermore found that the American population was transcriptionally highly diverged from all other populations concerning basal levels of gene expression. This was particularly true for stress and immune response genes, which might be the genetic basis for their elevated vigor. PMID:26154519

Survival Rate and Transcriptional Response upon Infection with the Generalist Parasite Beauveria bassiana in a World-Wide Sample of Drosophila melanogaster.

PubMed

Paparazzo, Francesco; Tellier, Aurélien; Stephan, Wolfgang; Hutter, Stephan

2015-01-01

The ability to cope with infection by a parasite is one of the major challenges for any host species and is a major driver of evolution. Parasite pressure differs between habitats. It is thought to be higher in tropical regions compared to temporal ones. We infected Drosophila melanogaster from two tropical (Malaysia and Zimbabwe) and two temperate populations (the Netherlands and North Carolina) with the generalist entomopathogenic fungus Beauveria bassiana to examine if adaptation to local parasite pressures led to differences in resistance. Contrary to previous findings we observed increased survival in temperate populations. This, however, is not due to increased resistance to infection per se, but rather the consequence of a higher general vigor of the temperate populations. We also assessed transcriptional response to infection within these flies eight and 24 hours after infection. Only few genes were induced at the earlier time point, most of which are involved in detoxification. In contrast, we identified more than 4,000 genes that changed their expression state after 24 hours. This response was generally conserved over all populations with only few genes being uniquely regulated in the temperate populations. We furthermore found that the American population was transcriptionally highly diverged from all other populations concerning basal levels of gene expression. This was particularly true for stress and immune response genes, which might be the genetic basis for their elevated vigor.

THE INFLUENCE OF MODEL TIME STEP ON THE RELATIVE SENSITIVITY OF POPULATION GROWTH TO SURVIVAL, GROWTH AND REPRODUCTION

EPA Science Inventory

Matrix population models are often used to extrapolate from life stage-specific stressor effects on survival and reproduction to population-level effects. Demographic elasticity analysis of a matrix model allows an evaluation of the relative sensitivity of population growth rate ...

Population dynamics along a primary succession gradient: do alpine species fit into demographic succession theory?

PubMed Central

Marcante, Silvia; Winkler, Eckart; Erschbamer, Brigitta

2009-01-01

Background and Aims Understanding processes and mechanisms governing changes in plant species along primary successions has been of major importance in ecology. However, to date hardly any studies have focused on the complete life cycle of species along a successional gradient, comparing pioneer, early and late-successional species. In this study it is hypothesized that pioneer species should initially have a population growth rate, λ, greater than one with high fecundity rates, and declining growth rates when they are replaced by late-successional species. Populations of late-successional species should also start, at the mid-successional stage (when pioneer species are declining), with growth rates greater than one and arrive at rates equal to one at the late successional stage, mainly due to higher survival rates that allow these species to persist for a long time. Methods The demography of pioneer- (Saxifraga aizoides), early (Artemisia genipi) and late-successional species (Anthyllis vulneraria ssp. alpicola) was investigated together with that of a ubiquitous species (Poa alpina) along the Rotmoos glacier foreland (2300–2400 m a.s.l., Central Alps, Austria) over 3 years. A matrix modelling approach was used to compare the main demographic parameters. Elasticity values were plotted in a demographic triangle using fecundity, individual growth and survival as vital rates contributing to the population growth rates. Key Results The results largely confirmed the predictions for population growth rates during succession. However, high survival rates of larger adults characterized all species, regardless of where they were growing along the succession. At the pioneer site, high mortality rates of seedlings, plantlets and young individuals were recorded. Fecundity was found to be of minor relevance everywhere, but it was nevertheless sufficient to increase or maintain the population sizes. Conclusions Demographically, all the species over all sites behaved like late-successional or climax species in secondary successions, mainly relying on survival of adult individuals. Survival serves as a buffer against temporal variation right from the beginning of the primary succession, indicating a major difference between primary and secondary succession. PMID:19273477

Breast cancer patients in Libya: Comparison with European and central African patients

PubMed Central

BODER, JAMELA MOSTAFA E.; ELMABROUK ABDALLA, FATHI B.; ELFAGEIH, MOHAMED AHMED; ABUSAA, ABUAGELA; BUHMEIDA, ABDELBASET; COLLAN, YRJÖ

2011-01-01

The present study evaluated the incidence of breast cancer in Libya and described the clinicopathological and demographic features. These features were then compared with corresponding data from patients from sub-Saharan Africa (Nigeria) and Europe (Finland). The study consisted of 234 patients with breast carcinoma, admitted to the African Oncology Institute in Sabratha, Libya, during the years 2002–2006. The pathological features were collected from pathology reports, patient histories from hospital files and the Sabratha Cancer Registry. The demographic differences between the Libyan, Nigerian and Finnish populations were prominent. The mean age of breast cancer patients in Libya was 46 years which was almost identical to that of Nigeria, but much lower than that of Finland. The Libyan breast cancer incidence was evaluated as 18.8 per 100,000 female individuals. This incidence was markedly higher in Finland, but was also high in Nigeria. Libyan and Nigerian breast cancer is predominantly of premenopausal type and exhibits unfavorable characteristics such as high histological grade and stage, large tumor size and frequent lymph node metastases. However, the histological types and histopathological risk features show similar importance regarding survival as European breast cancer cases. Survival in Libya ranks between the rates of survival in Nigeria (lowest) and Finland (highest). In conclusion, in Libya and other African countries, premenopausal breast cancer is more common than postmenopausal breast cancer. However, the opposite is true for Europe. Population differences may be involved, as suggested by the known variation, in the distribution of genetic markers in these populations. Different types of environmental impacts, however, cannot be excluded. PMID:22866085

Resistance rather than tolerance explains survival of savannah honeybees (Apis mellifera scutellata) to infestation by the parasitic mite Varroa destructor.

PubMed

Strauss, Ursula; Dietemann, Vincent; Human, Hannelie; Crewe, Robin M; Pirk, Christian W W

2016-03-01

Varroa destructor is considered the most damaging parasite affecting honeybees (Apis mellifera L.). However, some honeybee populations such as the savannah honeybee (Apis mellifera scutellata) can survive mite infestation without treatment. It is unclear if survival is due to resistance mechanisms decreasing parasite reproduction or to tolerance mechanisms decreasing the detrimental effects of mites on the host. This study investigates both aspects by quantifying the reproductive output of V. destructor and its physiological costs at the individual host level. Costs measured were not consistently lower when compared with susceptible honeybee populations, indicating a lack of tolerance. In contrast, reproduction of V. destructor mites was distinctly lower than in susceptible populations. There was higher proportion of infertile individuals and the reproductive success of fertile mites was lower than measured to date, even in surviving populations. Our results suggest that survival of savannah honeybees is based on resistance rather than tolerance to this parasite. We identified traits that may be useful for breeding programmes aimed at increasing the survival of susceptible populations. African honeybees may have benefited from a lack of human interference, allowing natural selection to shape a population of honeybees that is more resistant to Varroa mite infestation.

Managing American Oystercatcher (Haematopus palliatus) population qrowth by targeting nesting season vital rates

USGS Publications Warehouse

Felton, Shilo K.; Hostetter, Nathan J.; Pollock, Kenneth H.; Simons, Theodore R.

2017-01-01

In populations of long-lived species, adult survival typically has a relatively high influence on population growth. From a management perspective, however, adult survival can be difficult to increase in some instances, so other component rates must be considered to reverse population declines. In North Carolina, USA, management to conserve the American Oystercatcher (Haematopus palliatus) targets component vital rates related to fecundity, specifically nest and chick survival. The effectiveness of such a management approach in North Carolina was assessed by creating a three-stage female-based deterministic matrix model. Isoclines were produced from the matrix model to evaluate minimum nest and chick survival rates necessary to reverse population decline, assuming all other vital rates remained stable at mean values. Assuming accurate vital rates, breeding populations within North Carolina appear to be declining. To reverse this decline, combined nest and chick survival would need to increase from 0.14 to ≤ 0.27, a rate that appears to be attainable based on historical estimates. Results are heavily dependent on assumptions of other vital rates, most notably adult survival, revealing the need for accurate estimates of all vital rates to inform management actions. This approach provides valuable insights for evaluating conservation goals for species of concern.

Population trends and survival of nesting green sea turtles Chelonia mydas on Aves Island, Venezuela

USGS Publications Warehouse

Garcia-Cruz, Marco A.; Lampo, Margarita; Peñaloza, Claudia L.; Kendall, William L.; Solé, Genaro; Rodriguez-Clark, Kathryn M.

2015-01-01

Long-term demographic data are valuable for assessing the effect of anthropogenic impacts on endangered species and evaluating recovery programs. Using a 2-state open robust design model, we analyzed mark-recapture data from green turtles Chelonia mydas sighted between 1979 and 2009 on Aves Island, Venezuela, a rookery heavily impacted by human activities before it was declared a wildlife refuge in 1972. Based on the encounter histories of 7689 nesting females, we estimated the abundance, annual survival, and remigration intervals for this population. Female survival varied from 0.14-0.91, with a mean of 0.79, which is low compared to survival of other populations from the Caribbean (mean = 0.84) and Australia (mean = 0.95), even though we partially corrected for tag loss, which is known to negatively bias survival estimates. This supports prior suggestions that Caribbean populations in general, and the Aves Island population in particular, may be more strongly impacted than populations elsewhere. It is likely that nesters from this rookery are extracted while foraging in remote feeding grounds where hunting still occurs. Despite its relatively low survival, the nesting population at Aves Island increased during the past 30 years from approx. 500 to >1000 nesting females in 2009. Thus, this population, like others in the Caribbean and the Atlantic, seems to be slowly recovering following protective management. Although these findings support the importance of long-term conservation programs aimed at protecting nesting grounds, they also highlight the need to extend management actions to foraging grounds where human activities may still impact green turtle populations.

The effects of body size and climate on post-weaning survival of elephant seals at Heard Island

USGS Publications Warehouse

McMahon, Clive R; New, Leslie; Fairley, E.J.; Hindell, M.A.; Burton, H.R.

2015-01-01

The population size of southern elephant seals in the southern Indian and Pacific Oceans decreased precipitously between the 1950s and 1990s. To investigate the reasons behind this, we studied the population of southern elephant seals at Heard Island between 1949 and 1954, using data collected by the early Australian National Antarctic Research Expeditions. Seals were marked and measured (lengths) as weaned pups, and resighted at Heard and Marion islands and in the Vestfold Hills, Antarctica in subsequent years. Bayesian state-space mark-recapture models were used to determine post-weaning survival. Yearling survival was consistently lower (ϕy: 0.28–0.40) than sub-adult survival (ϕs: 0.79–0.83). We found evidence for constant sub-adult survival and time-dependent resight probabilities. Weaning length was an important determinate of yearling survival, with the probability of survival increasing with individual length. There was some suggestion that the Southern Annular Mode influenced yearling survival but this evidence was not strong. Nonetheless, our results provide further support showing that size at independence affects yearling survival. Given the known sensitivity of southern elephant seal populations to survival early in life, it is possible that the decline in population size at Heard Island between the 1950s and 1990s like that at Macquarie Island was due to low yearling survival mediated through maternal ability to produce large pups and the dominant environmental conditions mothers experience during pregnancy.

Incidence and survival time trends for Spanish children and adolescents with leukaemia from 1983 to 2007.

PubMed

Marcos-Gragera, R; Galceran, J; Martos, C; de Munain, A L; Vicente-Raneda, M; Navarro, C; Quirós-Garcia, J R; Sánchez, M-J; Ardanaz, E; Ramos, M; Mateos, A; Salmerón, D; Felipe, S; Peris-Bonet, R

2017-03-01

We have analysed incidence and survival trends of children and adolescents with leukaemia registered in Spanish population-based cancer registries during the period 1983-2007. Childhood and adolescent leukaemia cases were drawn from the 11 Spanish population-based cancer registries. For survival, registries with data for the period 1991-2005 and follow-up until 31-12-2010 were included. Overall incidence trends were evaluated using joinpoint analysis. Observed survival rates were estimated using Kaplan-Meier, and trends were tested using the log-rank test. Based on 2606 cases (2274 children and 332 adolescents), the overall age-adjusted incidence rate (ASRw) of leukaemia was 47.9 cases per million child-years in children and 23.8 in adolescents. The ASRw of leukaemia increased with an annual percentage change of 9.6 % (95 % CI: 2.2-17.6) until 1990 followed by a stabilisation of rates. In adolescents, incidence did not increase. Five-year survival increased from 66 % in 1991-1995 to 76 % in 2001-2005. By age, survival was dramatically lower in infants (0) and adolescents (15-19) than in the other age groups and no improvement was observed. In both children and adolescents, differences in 5-year survival rates among major subgroups of leukaemias were significant. The increasing incidence trends observed in childhood leukaemias during the study period were confined to the beginning of the period. Remarkable improvements in survival have been observed in Spanish children with leukaemias. However, this improvement was not observed in infants and adolescents.

Racial disparities in advanced-stage colorectal cancer survival.

PubMed

Wallace, Kristin; Hill, Elizabeth G; Lewin, David N; Williamson, Grace; Oppenheimer, Stephanie; Ford, Marvella E; Wargovich, Michael J; Berger, Franklin G; Bolick, Susan W; Thomas, Melanie B; Alberg, Anthony J

2013-03-01

African-Americans (AA) have a higher incidence of and lower survival from colorectal cancer (CRC) compared with European Americans (EA). In the present study, statewide, population-based data from South Carolina Central Cancer Registry are used to investigate the relationship between race and age on advanced-stage CRC survival. The study population was comprised of 3,865 advanced pathologically documented colon and rectal adenocarcinoma cases diagnosed between 01 January 1996 and 31 December 2006: 2,673 (69 %) EA and 1,192 (31 %) AA. Kaplan-Meier methods were used to generate median survival time and corresponding 95 % confidence intervals (CI) by race, age, and gender. Factors associated with survival were evaluated by fitting Cox proportional hazards regression models to generate hazard ratios (HR) and 95 % CI. We observed a significant interaction between race and age on CRC survival (p = 0.04). Among younger patients (<50 years), AA race was associated with a 1.34 times (95 % CI 1.06-1.71) higher risk of death compared with EA. Among older patients, we observed a modest increase in risk of death among AA men compared with EA [HR 1.16 (95 % CI 1.01-1.32)] but no difference by race between women [HR 0.94 (95 % CI 0.82-1.08)]. Moreover, we observed that the disparity in survival has worsened over the past 15 years. Future studies that integrate clinical, molecular, and treatment-related data are needed for advancing understanding of the racial disparity in CRC survival, especially for those <50 years old.

Dynamics of the double-crested cormorant population on Lake Ontario

USGS Publications Warehouse

Blackwell, Bradley F.; Stapanian, Martin A.; Weseloh, D.V. Chip

2002-01-01

After nearly 30 years of recolonization and expansion across North America, the double-crested cormorant (Phalacrocorax auritus) occupies the role of a perceived and, in some situations, realized threat to fish stocks and other resources. However, population data necessary to plan, defend, and implement management of this species are few. Our purpose was to gain insight into the relative contribution of various population parameters to the overall rate of population growth and identify data needs critical to improving our understanding of the dynamics of double-crested cormorant populations. We demonstrated the construction of a biologically reasonable representation of cormorant population growth on Lake Ontario (1979-2000) by referencing literature values for fertility, age at first breeding, and survival. These parameters were incorporated into a deterministic stage-classified matrix model. By calculating the elasticity of matrix elements (i.e., statgspecific fertility and survival), we found that cormorant population growth on Lake Ontario was most sensitive to survival of birds about to turn age 3 and older. Finally, we demonstrated how this information could be used to evaluate management scenarios and direct future research by simulating potential environmental effects on fertility and survival, as well as a 5-year egg-oiling program. We also demonstrated that survival of older birds exerts more effective population control than changes in fertility.

Long-term survival following in-hospital cardiac arrest: A matched cohort study☆

PubMed Central

Feingold, Paul; Mina, Michael J.; Burke, Rachel M.; Hashimoto, Barry; Gregg, Sara; Martin, Greg S.; Leeper, Kenneth; Buchman, Timothy

2016-01-01

Background Each year, 200,000 patients undergo an in-hospital cardiac arrest (IHCA), with approximately 15–20% surviving to discharge. Little is known, however, about the long-term prognosis of these patients after discharge. Previous efforts to describe out-of-hospital survival of IHCA patients have been limited by small sample sizes and narrow patient populations Methods A single institution matched cohort study was undertaken to describe mortality following IHCA. Patients surviving to discharge following an IHCA between 2008 and 2010 were matched on age, sex, race and hospital admission criteria with non-IHCA hospital controls and follow-up between 9 and 45 months. Kaplan–Meier curves and Cox PH models assessed differences in survival. Results Of the 1262 IHCAs, 20% survived to hospital discharge. Of those discharged, survival at 1 year post-discharge was 59% for IHCA patients and 82% for controls (p < 0.0001). Hazard ratios (IHCA vs. controls) for mortality were greatest within the 90 days following discharge (HR = 2.90, p < 0.0001) and decreased linearly thereafter, with those surviving to one year post-discharge having an HR for mortality below 1.0. Survival after discharge varied amongst IHCA survivors. When grouped by discharge destination, out of hospital survival varied; in fact, IHCA patients discharged home without services demonstrated no survival difference compared to their non-IHCA controls (HR 1.10, p = 0.72). IHCA patients discharged to long-term hospital care or hospice, however, had a significantly higher mortality compared to matched controls (HR 3.91 and 20.3, respectively; p < 0.0001). Conclusion Among IHCA patients who survive to hospital discharge, the highest risk of death is within the first 90 days after discharge. Additionally, IHCA survivors overall have increased long-term mortality vs. controls. Survival rates were varied widely with different discharge destinations, and those discharged to home, skilled nursing facilities or to rehabilitation services had survival rates no different than controls. Thus, increased mortality was primarily driven by patients discharged to long-term care or hospice. PMID:26703463

Effects of weather on survival in populations of boreal toads in Colorado

USGS Publications Warehouse

Scherer, R. D.; Muths, E.; Lambert, B.A.

2008-01-01

Understanding the relationships between animal population demography and the abiotic and biotic elements of the environments in which they live is a central objective in population ecology. For example, correlations between weather variables and the probability of survival in populations of temperate zone amphibians may be broadly applicable to several species if such correlations can be validated for multiple situations. This study focuses on the probability of survival and evaluates hypotheses based on six weather variables in three populations of Boreal Toads (Bufo boreas) from central Colorado over eight years. In addition to suggesting a relationship between some weather variables and survival probability in Boreal Toad populations, this study uses robust methods and highlights the need for demographic estimates that are precise and have minimal bias. Capture-recapture methods were used to collect the data, and the Cormack-Jolly-Seber model in program MARK was used for analysis. The top models included minimum daily winter air temperature, and the sum of the model weights for these models was 0.956. Weaker support was found for the importance of snow depth and the amount of environmental moisture in winter in modeling survival probability. Minimum daily winter air temperature was positively correlated with the probability of survival in Boreal Toads at other sites in Colorado and has been identified as an important covariate in studies in other parts of the world. If air temperatures are an important component of survival for Boreal Toads or other amphibians, changes in climate may have profound impacts on populations. Copyright 2008 Society for the Study of Amphibians and Reptiles.

Survival estimates for reintroduced populations of the Chiricahua Leopard Frog (Lithobates chiricahuensis)

USGS Publications Warehouse

Howell, Paige E; Hossack, Blake R.; Muths, Erin L.; Sigafus, Brent H.; Chandler, Richard B.

2016-01-01

Global amphibian declines have been attributed to a number of factors including disease, invasive species, habitat degradation, and climate change. Reintroduction is one management action that is commonly used with the goal of recovering imperiled species. The success of reintroductions varies widely, and evaluating their efficacy requires estimates of population viability metrics, such as underlying vital rates and trends in abundance. Although rarely quantified, assessing vital rates for recovering populations provides a more mechanistic understanding of population growth than numerical trends in population occupancy or abundance. We used three years of capture-mark-recapture data from three breeding ponds and a Cormack-Jolly-Seber model to estimate annual apparent survival for reintroduced populations of the federally threatened Chiricahua Leopard Frog (Lithobates chiricahuensis) at the Buenos Aires National Wildlife Refuge (BANWR), in the Altar Valley, Arizona, USA. To place our results in context, we also compiled published survival estimates for other ranids. Average apparent survival of Chiricahua Leopard Frogs at BANWR was 0.27 (95% CI [0.07, 0.74]) and average individual capture probability was 0.02 (95% CI [0, 0.05]). Our apparent survival estimate for Chiricahua Leopard Frogs is lower than for most other ranids and is not consistent with recent research that showed metapopulation viability in the Altar Valley is high. We suggest that low apparent survival may be indicative of high emigration rates. We recommend that future research should estimate emigration rates so that actual, rather than apparent, survival can be quantified to improve population viability assessments of threatened species following reintroduction efforts.

On valuing patches: Estimating contributions to metapopulation growth with reverse-time capture-recapture modelling

USGS Publications Warehouse

Sanderlin, J.S.; Waser, P.M.; Hines, J.E.; Nichols, J.D.

2012-01-01

Metapopulation ecology has historically been rich in theory, yet analytical approaches for inferring demographic relationships among local populations have been few. We show how reverse-time multi-state capture-recapture models can be used to estimate the importance of local recruitment and interpopulation dispersal to metapopulation growth. We use 'contribution metrics' to infer demographic connectedness among eight local populations of banner-tailed kangaroo rats, to assess their demographic closure, and to investigate sources of variation in these contributions. Using a 7 year dataset, we show that: (i) local populations are relatively independent demographically, and contributions to local population growth via dispersal within the system decline with distance; (ii) growth contributions via local survival and recruitment are greater for adults than juveniles, while contributions involving dispersal are greater for juveniles; (iii) central populations rely more on local recruitment and survival than peripheral populations; (iv) contributions involving dispersal are not clearly related to overall metapopulation density; and (v) estimated contributions from outside the system are unexpectedly large. Our analytical framework can classify metapopulations on a continuum between demographic independence and panmixia, detect hidden population growth contributions, and make inference about other population linkage forms, including rescue effects and source-sink structures. Finally, we discuss differences between demographic and genetic population linkage patterns for our system. ?? 2011 The Royal Society.

Large-scale adaptive differentiation in the alpine perennial herb Arabis alpina.

PubMed

Toräng, Per; Wunder, Jörg; Obeso, José Ramón; Herzog, Michel; Coupland, George; Ågren, Jon

2015-04-01

Information about the incidence and magnitude of local adaptation can help to predict the response of natural populations to a changing environment, and should be of particular interest in arctic and alpine environments where the effects of climate change are expected to be severe. To quantify adaptive differentiation in the arctic-alpine perennial herb Arabis alpina, we conducted reciprocal transplant experiments for 3 yr between Spanish and Scandinavian populations. At the sites of one Spanish and one Scandinavian population, we planted seedlings representing two Spanish and four Scandinavian populations, and recorded survival, flowering propensity and fecundity. The experiment was replicated in two subsequent years. The results demonstrate strong adaptive differentiation between A. alpina populations from the two regions. At the field site in Spain, survival and fruit production of Spanish populations were higher than those of Scandinavian populations, while the opposite was true at the site in Scandinavia, and these differences were consistent across years. By comparison, fitness varied little among populations from the same region. The results suggest that the magnitude and geographical scale of local adaptation need to be considered in predictions of the effects of global change on the dynamics of arctic and alpine plant populations. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Efficacy and toxicity differences in lung cancer populations in the era of clinical trials globalization: the 'common arm' approach.

PubMed

Mack, Philip C; Gandara, David R; Lara, Primo N

2012-12-01

Historically, notable variability has been observed in clinical trial outcomes between different regions and populations worldwide, even when employing the same cytotoxic regimen in lung cancer. These divergent results underscore the inherent challenges in interpreting trials conducted abroad and raise questions regarding the general applicability of transnational clinical trials. Various reasons have been postulated to account for these differences in efficacy and toxicity, including trial design, eligibility criteria, patient demographics and, perhaps most intriguingly, population-related pharmacogenomics. However, without methodology to control for such variables, these hypotheses remain largely untested. The authors previously developed the 'common arm' approach in order to directly compare efficacy and toxicity results of trials simultaneously performed in different countries. By standardizing clinical trial-associated variables such as treatment regimens (dose, schedule, and so on), eligibility, staging, response and toxicity criteria, this approach has the potential to determine the underlying reasons for divergences in trial outcomes across countries, and whether population-associated polymorphisms contribute to these differences. In the past decade, Japanese and US investigators have applied the common arm analytic method to trials in both extensive-stage small-cell lung cancer (SCLC) and advanced nonSCLC. In the SCLC analysis, a comparison of the cisplatin/irinotecan arms from both trials revealed significant differences in response rates and overall survival. Significant differences were also observed in the distribution of gender and performance status. The common arm analysis in nonSCLC included two trials from Japan and one from the USA, each containing a 'common' carboplatin/paclitaxel arm. Clinical results were similar in the two Japanese trials, but were significantly different from the US trial with regard to survival, neutropenia, febrile neutropenia and anemia. The underlying basis for these divergent outcomes is discussed. The common arm methodology provides a template for identifying and interpreting patient outcome differences across populations, and is an instructive lesson in the burgeoning era of clinical trials globalization.

Population dynamics of American dog ticks (Acari: Ixodidae) along park trails

USGS Publications Warehouse

Carroll, J.F.; Russek-Cohen, E.; Nichols, J.D.; Hines, J.E.

1991-01-01

We conclude a mark-recapture study in which drag-collected ticks were removed from some park trails weekly from April to July. Weekly survival rates (probability of surviving and remaining on the trails) were significantly lower on trials used heavily by hikers, horses, and pets than on trails used less frequently. Although usage was the only obvious difference among these trails, differences in weekly survival rate estimates may be attributable to differential success in acquiring hosts. The estimated probability of capturing a host-seeking tick located along a trail on a single drag was 0.20 on the drag alone, and 0.25 including the person dragging. When routes parallel to the trails and of equal lengths were dragged immediately after sampling the trails, only .apprxeq. 5% as many ticks (including ticks on the person dragging) were found off the trails as on them. We found no evidence of reduced tick numbers on removal trails, but this result should be considered inconclusive because the power of the discerning test was low. However, the data reported here provide insights into turnover rates of the adult Dermacentor variabilis population and effectiveness of the drag as a sampling device.

Resistance of Feather-Associated Bacteria to Intermediate Levels of Ionizing Radiation near Chernobyl

PubMed Central

Ruiz-González, Mario Xavier; Czirják, Gábor Árpád; Genevaux, Pierre; Møller, Anders Pape; Mousseau, Timothy Alexander; Heeb, Philipp

2016-01-01

Ionizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different γ radiation doses ranging from 0.46 to 3.96 kGy to test whether chronic exposure to radiation had selected for resistant bacterial strains. Experimental radiation duration had an increasingly overall negative effect on the survival of all bacterial communities. After exposure to γ radiation, bacteria isolated from the site with intermediate background radiation levels survived better and produced more colonies than the bacterial communities from other study sites with higher or lower background radiation levels. Long-term effects of radiation in natural populations might be an important selective pressure on traits of bacteria that facilitate survival in certain environments. Our findings indicate the importance of further studies to understand the proximate mechanisms acting to buffer the negative effects of ionizing radiation in natural populations. PMID:26976674

Resistance of Feather-Associated Bacteria to Intermediate Levels of Ionizing Radiation near Chernobyl.

PubMed

Ruiz-González, Mario Xavier; Czirják, Gábor Árpád; Genevaux, Pierre; Møller, Anders Pape; Mousseau, Timothy Alexander; Heeb, Philipp

2016-03-15

Ionizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different γ radiation doses ranging from 0.46 to 3.96 kGy to test whether chronic exposure to radiation had selected for resistant bacterial strains. Experimental radiation duration had an increasingly overall negative effect on the survival of all bacterial communities. After exposure to γ radiation, bacteria isolated from the site with intermediate background radiation levels survived better and produced more colonies than the bacterial communities from other study sites with higher or lower background radiation levels. Long-term effects of radiation in natural populations might be an important selective pressure on traits of bacteria that facilitate survival in certain environments. Our findings indicate the importance of further studies to understand the proximate mechanisms acting to buffer the negative effects of ionizing radiation in natural populations.

Movement patterns, habitat use, and survival of Lahontan cutthroat trout in the Truckee River

USGS Publications Warehouse

Alexiades, Alexander V.; Peacock, Mary M.; Al-Chokhachy, Robert K.

2012-01-01

Habitat fragmentation, hybridization, and competition with nonnative salmonids are viewed as major threats to Lahontan cutthroat trout Oncorhynchus clarkii henshawi. Understanding Lahontan cutthroat trout behavior and survival is a necessary step in the reintroduction and establishment of naturally reproducing populations of Lahontan cutthroat trout. We used weekly radiotelemetry monitoring to examine movement patterns, habitat use, and apparent survival of 42 hatchery-reared Lahontan cutthroat trout in a 16.5-km stretch of the Truckee River, Nevada, across three reaches separated by barriers to upstream movement. We found differences in total movement distances and home range sizes of fish in different reaches within our study area. Fish used pool habitats more than fast water habitats in all reaches. Time of year, stream temperature, and fish standard length covariates had the strongest relationship with apparent survival. Monthly apparent survival was lowest in January, which coincided with the lowest flows and temperatures during the study period. Our results verify the mobility of Lahontan cutthroat trout and indicate that conditions during winter may limit the survival and reintroduction success in the portions of the Truckee River evaluated in this study.

Impact of hot events at different developmental stages of a moth: the closer to adult stage, the less reproductive output

PubMed Central

Zhang, Wei; Chang, Xiang-Qian; Hoffmann, AryA.; Zhang, Shu; Ma, Chun-Sen

2015-01-01

Hot days in summer (involving a few hours at particularly high temperatures) are expected to become more common under climate change. How such events at different life stages affect survival and reproduction remains unclear in most organisms. Here, we investigated how an exposure to 40 °C at different life stages in the global insect pest, Plutella xylostella, affects immediate survival, subsequent survival and reproductive output. First-instar larvae showed the lowest survival under heat stress, whereas 3rd-instar larvae were relatively heat resistant. Heat exposure at the 1st-instar or egg stage did not influence subsequent maturation success, while exposure at the 3rd-instar larval stage did have an effect. We found that heat stress at developmental stages closer to adult stage caused greater detrimental effects on reproduction than heat stress experienced at earlier life stages. The effects of hot events on insect populations can therefore depend critically on the timing of the event relative to an organism’s life-cycle. PMID:26000790

Modulating cell-to-cell variability and sensitivity to death ligands by co-drugging

NASA Astrophysics Data System (ADS)

Flusberg, Deborah A.; Sorger, Peter K.

2013-06-01

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) holds promise as an anti-cancer therapeutic but efficiently induces apoptosis in only a subset of tumor cell lines. Moreover, even in clonal populations of responsive lines, only a fraction of cells dies in response to TRAIL and individual cells exhibit cell-to-cell variability in the timing of cell death. Fractional killing in these cell populations appears to arise not from genetic differences among cells but rather from differences in gene expression states, fluctuations in protein levels and the extent to which TRAIL-induced death or survival pathways become activated. In this study, we ask how cell-to-cell variability manifests in cell types with different sensitivities to TRAIL, as well as how it changes when cells are exposed to combinations of drugs. We show that individual cells that survive treatment with TRAIL can regenerate the sensitivity and death-time distribution of the parental population, demonstrating that fractional killing is a stable property of cell populations. We also show that cell-to-cell variability in the timing and probability of apoptosis in response to treatment can be tuned using combinations of drugs that together increase apoptotic sensitivity compared to treatment with one drug alone. In the case of TRAIL, modulation of cell-to-cell variability by co-drugging appears to involve a reduction in the threshold for mitochondrial outer membrane permeabilization.

Prognostic factors and survival of colorectal cancer in Kurdistan province, Iran: A population-based study (2009-2014).

PubMed

Rasouli, Mohammad Aziz; Moradi, Ghobad; Roshani, Daem; Nikkhoo, Bahram; Ghaderi, Ebrahim; Ghaytasi, Bahman

2017-02-01

Colorectal cancer (CRC) survival varies at individual and geographically level. This population-based study aimed to evaluating various factors affecting the survival rate of CRC patients in Kurdistan province.In a retrospective cohort study, patients diagnosed as CRC were collected through a population-based study from March 1, 2009 to 2014. The data were collected from Kurdistan's Cancer Registry database. Additional information and missing data were collected reference to patients' homes, medical records, and pathology reports. The CRC survival was calculated from the date of diagnosis to the date of cancer-specific death or the end of follow-up (cutoff date: October 2015). Kaplan-Meier method and log-rank test were used for the univariate analysis of survival in various subgroups. The proportional-hazard model Cox was also used in order to consider the effects of different factors on survival including age at diagnosis, place of residence, marital status, occupation, level of education, smoking, economic status, comorbidity, tumor stage, and tumor grade.A total number of 335 patients affected by CRC were assessed and the results showed that 1- and 5-year survival rate were 87% and 33%, respectively. According to the results of Cox's multivariate analysis, the following factors were significantly related to CRC survival: age at diagnosis (≥65 years old) (HR 2.08, 95% CI: 1.17-3.71), single patients (HR 1.62, 95% CI: 1.10-2.40), job (worker) (HR 2.09, 95% CI: 1.22-3.58), educational level: diploma or below (HR 0.61, 95% CI: 0.39-0.92), wealthy economic status (HR 0.51, 95% CI: 0.31-0.82), tumor grade in poorly differentiated (HR 2.25, 95% CI: 1.37-3.69), and undifferentiated/anaplastic grade (HR 2.90, 95% CI: 1.67-4.98).We found that factors such as low education, inappropriate socioeconomic status, and high tumor grade at the time of disease diagnosis were effective in the poor survival of CRC patients in Kurdistan province; this, which need more attention.

Long term monitoring of jaguars in the Cockscomb Basin Wildlife Sanctuary, Belize; Implications for camera trap studies of carnivores.

PubMed

Harmsen, Bart J; Foster, Rebecca J; Sanchez, Emma; Gutierrez-González, Carmina E; Silver, Scott C; Ostro, Linde E T; Kelly, Marcella J; Kay, Elma; Quigley, Howard

2017-01-01

In this study, we estimate life history parameters and abundance for a protected jaguar population using camera-trap data from a 14-year monitoring program (2002-2015) in Belize, Central America. We investigated the dynamics of this jaguar population using 3,075 detection events of 105 individual adult jaguars. Using robust design open population models, we estimated apparent survival and temporary emigration and investigated individual heterogeneity in detection rates across years. Survival probability was high and constant among the years for both sexes (φ = 0.78), and the maximum (conservative) age recorded was 14 years. Temporary emigration rate for the population was random, but constant through time at 0.20 per year. Detection probability varied between sexes, and among years and individuals. Heterogeneity in detection took the form of a dichotomy for males: those with consistently high detection rates, and those with low, sporadic detection rates, suggesting a relatively stable population of 'residents' consistently present and a fluctuating layer of 'transients'. Female detection was always low and sporadic. On average, twice as many males than females were detected per survey, and individual detection rates were significantly higher for males. We attribute sex-based differences in detection to biases resulting from social variation in trail-walking behaviour. The number of individual females detected increased when the survey period was extended from 3 months to a full year. Due to the low detection rates of females and the variable 'transient' male subpopulation, annual abundance estimates based on 3-month surveys had low precision. To estimate survival and monitor population changes in elusive, wide-ranging, low-density species, we recommend repeated surveys over multiple years; and suggest that continuous monitoring over multiple years yields even further insight into population dynamics of elusive predator populations.

The Influence of Agroforestry and Other Land-Use Types on the Persistence of a Sumatran Tiger ( Panthera tigris sumatrae) Population: An Individual-Based Model Approach

NASA Astrophysics Data System (ADS)

Imron, Muhammad Ali; Herzog, Sven; Berger, Uta

2011-08-01

The importance of preserving both protected areas and their surrounding landscapes as one of the major conservation strategies for tigers has received attention over recent decades. However, the mechanism of how land-use surrounding protected areas affects the dynamics of tiger populations is poorly understood. We developed Panthera Population Persistence (PPP)—an individual-based model—to investigate the potential mechanism of the Sumatran tiger population dynamics in a protected area and under different land-use scenarios surrounding the reserve. We tested three main landscape compositions (single, combined and real land-uses of Tesso-Nilo National Park and its surrounding area) on the probability of and time to extinction of the Sumatran tiger over 20 years in Central Sumatra. The model successfully explains the mechanisms behind the population response of tigers under different habitat landscape compositions. Feeding and mating behaviours of tigers are key factors, which determined population persistence in a heterogeneous landscape. All single land-use scenarios resulted in tiger extinction but had a different probability of extinction within 20 years. If tropical forest was combined with other land-use types, the probability of extinction was smaller. The presence of agroforesty and logging concessions adjacent to protected areas encouraged the survival of tiger populations. However, with the real land-use scenario of Tesso-Nilo National Park, tigers could not survive for more than 10 years. Promoting the practice of agroforestry systems surrounding the park is probably the most reasonable way to steer land-use surrounding the Tesso-Nilo National Park to support tiger conservation.

Age-specific survival estimates of King Eiders derived from satellite telemetry

USGS Publications Warehouse

Oppel, Steffen; Powell, Abby N.

2010-01-01

Age- and sex-specific survival and dispersal are important components in the dynamics and genetic structure of bird populations. For many avian taxa survival rates at the adult and juvenile life stages differ, but in long-lived species juveniles' survival is logistically challenging to study. We present the first estimates of hatch-year annual survival rates for a sea duck, the King Eider (Somateria spectabilis), estimated from satellite telemetry. From 2006 to 2008 we equipped pre-fiedging King Eiders with satellite transmitters on breeding grounds in Alaska and estimated annual survival rates during their first 2 years of life with known-fate models. We compared those estimates to survival rates of adults marked in the same area from 2002 to 2008. Hatch-year survival varied by season during the first year of life, and model-averaged annual survival rate was 0.67 (95% CI: 0.48–0.80). We did not record any mortality during the second year and were therefore unable to estimate second-year survival rate. Adults' survival rate was constant through the year (0.94, 95% CI: 0.86–0.97). No birds appeared to breed during their second summer. While 88% of females with an active transmitter (n = 9) returned to their natal area at the age of 2 years, none of the 2-year old males (n = 3) did. This pattern indicates that females' natal philopatry is high and suggests that males' higher rates of dispersal may account for sex-specific differences in apparent survival rates of juvenile sea ducks when estimated with mark—recapture methods.

The Role of Stage at Diagnosis in Colorectal Cancer Black-White Survival Disparities: A Counterfactual Causal Inference Approach.

PubMed

Valeri, Linda; Chen, Jarvis T; Garcia-Albeniz, Xabier; Krieger, Nancy; VanderWeele, Tyler J; Coull, Brent A

2016-01-01

To date, a counterfactual framework has not been used to study determinants of social inequalities in cancer. Considering the case of colorectal cancer, for which racial/ethnic differences in stage at diagnosis and survival are well documented, we quantify the extent to which black versus white survival disparities would be reduced had disparities in stage at diagnosis been eliminated in a large patient population. We obtained data on colorectal cancer patients (diagnosed between 1992 and 2005 and followed until 2010) from US-SEER (Surveillance, Epidemiology, and End Results) cancer registries. We employed a counterfactual approach to estimate the mean survival time up to the 60th month since diagnosis for black colorectal cancer patients had black-white disparities in stage at diagnosis been eliminated. Black patients survive approximately 4.0 [confidence interval (CI), 4.6-3.2] months less than white patients within five years since diagnosis. Had disparities in stage at diagnosis been eliminated, survival disparities decrease to 2.6 (CI, 3.4-1.7) months, an approximately 35% reduction. For patients diagnosed after the age of 65 years, disparities would be halved, while reduction of approximately 30% is estimated for younger patients. Survival disparities would be reduced by approximately 44% for women and approximately 26% for men. Employing a counterfactual approach and allowing for heterogeneities in black-white disparities across patients' characteristics, we give robust evidence that elimination of disparities in stage at diagnosis contributes to a substantial reduction in survival disparities in colorectal cancer. We provide the first evidence in the SEER population that elimination of inequities in stage at diagnosis might lead to larger reductions in survival disparities among elderly and women. ©2015 American Association for Cancer Research.

Socioeconomic deprivation and survival after stroke: findings from the prospective South London Stroke Register of 1995 to 2011.

PubMed

Chen, Ruoling; McKevitt, Christopher; Rudd, Anthony G; Wolfe, Charles D A

2014-01-01

Previous findings of the association between socioeconomic deprivation (SED) and survival after stroke are inconsistent. There is less investigation on long-term survival. We assessed the associations in a multi-ethnic population in England. We examined data from 4398 patients (3103 whites, 932 blacks, and 253 Asians/others) with first-ever stroke, collected by a population-based stroke register in South London from 1995 to 2011. SED was measured using the Carstairs index score-the higher score, the more deprived. It was analyzed in multivariate Cox regression models in relation to survival after stroke. During 17-year follow-up 2754 patients died. The quartile data of Carstairs score showed no significant association of SED with survival in patients, except for black Caribbeans and Africans. Black patients with the fourth quartile SED had a multivariate adjusted hazard ratio of 1.76 (95% confidence interval, 1.06-2.94) for 3-month mortality and 1.54 (1.00-2.37) for 1-year mortality. After adjustment for acute stroke care provisions, these were no longer significant. However, the sextile data of Carstairs score showed a consistent association of SED with survival after stroke; all patients with the sixth sextile had a fully adjusted hazard ratio of 1.23 (1.05-1.44) for 3-month mortality and 1.13 (1.01-1.25) for 17-year mortality. There is a weak but significant association of SED with reduced survival after stroke in England. SED in blacks may have a stronger impact on short-term survival when compared with white patients. Further efforts are required to achieve equality in survival among patients with stroke of different socioeconomic groups.

Demographics of an ornate box turtle population experiencing minimal human-induced disturbances

USGS Publications Warehouse

Converse, S.J.; Iverson, J.B.; Savidge, J.A.

2005-01-01

Human-induced disturbances may threaten the viability of many turtle populations, including populations of North American box turtles. Evaluation of the potential impacts of these disturbances can be aided by long-term studies of populations subject to minimal human activity. In such a population of ornate box turtles (Terrapene ornata ornata) in western Nebraska, we examined survival rates and population growth rates from 1981-2000 based on mark-recapture data. The average annual apparent survival rate of adult males was 0.883 (SE = 0.021) and of adult females was 0.932 (SE = 0.014). Minimum winter temperature was the best of five climate variables as a predictor of adult survival. Survival rates were highest in years with low minimum winter temperatures, suggesting that global warming may result in declining survival. We estimated an average adult population growth rate (????) of 1.006 (SE = 0.065), with an estimated temporal process variance (????2) of 0.029 (95% CI = 0.005-0.176). Stochastic simulations suggest that this mean and temporal process variance would result in a 58% probability of a population decrease over a 20-year period. This research provides evidence that, unless unknown density-dependent mechanisms are operating in the adult age class, significant human disturbances, such as commercial harvest or turtle mortality on roads, represent a potential risk to box turtle populations. ?? 2005 by the Ecological Society of America.

Survival of Seasonal Flooding in the Amazon by the Terrestrial Insect Conotrachelus dubiae O'Brien & Couturier (Coleoptera: Curculionidae), a Pest of the Camu-Camu Plant, Myrciaria dubia (Myrtaceae).

PubMed

Delgado, C; Couturier, G; Fine, P V A

2014-08-01

The weevil Conotrachelus dubiae O'Brien & Couturier (Coleoptera: Curculionidae) is a pest of an economically important Amazonian fruit tree Myrciaria dubia (Myrtaceae). This tree grows in seasonally flooded environments, and how weevil larvae survive flooding has not been studied. From December 2004 to May 2009, five experiments were conducted in natural conditions and in the laboratory, with the aim of understanding the mechanisms that allow the survival of C. dubiae larvae in seasonal floods in Amazonia. The larvae of C. dubiae were kept under water for over 93 days. Older instars exposed to periodic circulation of water survived better than younger instars in addition to all larvae that were kept continuously under uncirculated water. Individuals that were collected from plots of M. dubia located in flooded soils and non-flooded soils did not exhibit statistically significant differences in their levels of survival indicating that the variation in survival of flooding events is due to phenotypic plasticity of the species and not to local adaptation by the populations in different environments. We speculate that larvae can survive floods without major physiological changes as larvae appear to obtain oxygen from water by cutaneous diffusion, assisted by caudal movements.

Assessment of Subyearling Chinook Salmon Survival through the Federal Hydropower Projects in the Main-Stem Columbia River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Skalski, J. R.; Eppard, M. B.; Ploskey, Gene R.

2014-07-11

High survival through hydropower projects is an essential element in the recovery of salmonid populations in the Columbia River. It is also a regulatory requirement under the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp) established under the Endangered Species Act. It requires dam passage survival to be ≥0.96 and ≥0.93 for spring and summer outmigrating juvenile salmonids, respectively, and estimated with a standard error ≤ 0.015. An innovative virtual/paired-release design was used to estimate dam passage survival, defined as survival from the face of a dam to the tailrace mixing zone. A coordinated four-dam study was conductedmore » during the 2012 summer outmigration using 14,026 run-of-river subyearling Chinook salmon surgically implanted with acoustic micro-transmitter (AMT) tags released at 9 different locations, and monitored on 14 different detection arrays. Each of the four estimates of dam passage survival exceeded BiOp requirements with values ranging from 0.9414 to 0.9747 and standard errors, 0.0031 to 0.0114. Two consecutive years of survival estimates must meet BiOp standards in order for a hydropower project to be in compliance with recovery requirements for a fish stock.« less

Differences in Childhood Leukemia Incidence and Survival between Southern Thailand and the United States: A Population-Based Analysis

PubMed Central

Demanelis, Kathryn; Sriplung, Hutcha; Meza, Rafael; Wiangnon, Surapon; Rozek, Laura S.; Scheurer, Michael E.; Lupo, Philip J.

2015-01-01

BACKGROUND Childhood leukemia incidence and survival varies globally, and this variation may be attributed to environmental risk factors, genetics, and/or disparities in diagnosis and treatment. PROCEDURE We analyzed childhood leukemia incidence and survival trends in children age 0–19 years from 1990 to 2011 in Songkhla, Thailand (n=316) and compared these results to US data from the Surveillance, Epidemiology, and End Results (SEER) registry (n=6,738). We computed relative survival using Ederer II and estimated survival functions using the Kaplan-Meier method. Changes in incidence and five-year survival by year of diagnosis were evaluated using joinpoint regression and are reported as annual percent changes (APC). RESULTS The age-standardized incidence of leukemia was 3.2 and 4.1 cases per 100,000 in Songkhla and SEER-9, respectively. In Songkhla, incidence from 1990–2011 significantly increased for leukemia (APC=1.7%, p=0.031) and acute lymphoblastic leukemia (ALL) (APC=1.8%, p=0.033). Acute myeloid leukemia (AML) incidence significantly increased (APC=4.2%, p=0.044) and was significantly different from the US (p=0.026), where incidence was stable during the same period (APC=0.3%, p=0.541). The overall five-year relative survival for leukemia was lower than that reported in the US (43% vs. 79%). Five-year survival significantly improved by at least 2% per year from 1990–2011 in Songkhla for leukemia, ALL, and AML (p<0.050). CONCLUSIONS While leukemia and ALL incidence increased in Songkhla, differences in leukemia trends, particularly AML incidence, may suggest etiologic or diagnostic differences between Songkhla and the US. This work highlights the importance of evaluating childhood cancer trends in low- and middle-income countries. PMID:25962869

Mortality in the Vertebroplasty Population

PubMed Central

McDonald, Robert J.; Achenbach, Sara; Atkinson, Elizabeth; Gray, Leigh A.; Cloft, Harry J.; Melton, L. Joseph; Kallmes, David F.

2011-01-01

Purpose Vertebroplasty is an effective treatment for painful compression fractures refractory to conservative management. Since there are limited data regarding the survival characteristics of this patient population, we compared the survival of a treated to an untreated vertebral fracture cohort to determine if vertebroplasty affects mortality rates. Materials and Methods The survival of a treated cohort, comprising 524 vertebroplasty recipients with refractory osteoporotic vertebral compression fractures, was compared to a separate, historical cohort of 589 subjects with fractures not treated by vertebroplasty who were identified from the Rochester Epidemiology Project. Mortality was compared between cohorts using Cox proportional hazard models adjusting for age, gender, and Charlson indices of co-morbidity. Mortality was also correlated with pre-, peri-, and post-procedural clinical metrics (e.g., cement volume utilization, Roland-Morris Disability Questionnaire score, analog pain scales, frequency of narcotic use, and improvements in mobility) within the treated cohort. Results Vertebroplasty recipients demonstrated 77% of the survival expected for individuals of similar age, ethnicity, and gender within the US population. When compared to individuals with both symptomatic and asymptomatic untreated vertebral fractures, vertebroplasty recipients retained a 17% greater mortality risk. However, when compared to symptomatic untreated vertebral fractures, vertebroplasty recipients had no increased mortality following adjustment for differences in age, sex and co-morbidity (HR 1.02; CI 0.82–1.25). In addition, no clinical metrics used to assess the efficacy of vertebroplasty were predictive of survival. Conclusion Vertebroplasty recipients have mortality rates similar to individuals with untreated symptomatic fractures but worse mortality compared to those with asymptomatic vertebral fractures. PMID:21998109

Impact of insect growth regulators on the predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae).

PubMed

Rugno, Gabriel Rodrigo; Zanardi, Odimar Zanuzo; Bajonero Cuervo, Johanna; de Morais, Matheus Rovere; Yamamoto, Pedro Takao

2016-07-01

The generalist predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae) is an important biological control agent of several arthropod pests in different agroecosystems. This study assessed the lethal and sublethal effects of six insect growth regulators sprayed on first-instar larvae of C. cincta. Lufenuron and diflubenzuron were highly harmful to first-instar larvae of C. cincta, causing 100 % of mortality before they reached the second instar. Buprofezin caused ~25 % mortality of the larvae and considerably reduced the fecundity and longevity of the insects, but substantially increased the proportion of females in the surviving population of C. cincta. Methoxyfenozide and tebufenozide did not affect the duration and survival of the immature stages, but methoxyfenozide significantly reduced the fecundity and longevity of the insects. Pyriproxyfen reduced the survival of the larval stage by 19.5 %, but did not affect the development, survival and reproduction of the surviving individuals. Based on reduction coefficient, the insecticides diflubenzuron and lufenuron were considered harmful to C. cincta, whereas buprofezin and methoxyfenozide were slightly harmful and tebufenozide and pyriproxyfen were harmless. The estimation of life-table parameters indicated that buprofezin and methoxyfenozide significantly reduced the R o , r and λ of C. cincta, whereas pyriproxyfen and tebufenozide caused no adverse effect on population parameters, indicating that these insecticides could be suitable for use in pest management programs towards the conservation and population increase of the predator in agroecosystems. However, more studies should be conducted to evaluate the compatibility of these insecticides with the predator C. cincta under semi-field and field conditions.

Conditional net survival: Relevant prognostic information for colorectal cancer survivors. A French population-based study.

PubMed

Drouillard, Antoine; Bouvier, Anne-Marie; Rollot, Fabien; Faivre, Jean; Jooste, Valérie; Lepage, Côme

2015-07-01

Traditionally, survival estimates have been reported as survival from the time of diagnosis. A patient's probability of survival changes according to time elapsed since the diagnosis and this is known as conditional survival. The aim was to estimate 5-year net conditional survival in patients with colorectal cancer in a well-defined French population at yearly intervals up to 5 years. Our study included 18,300 colorectal cancers diagnosed between 1976 and 2008 and registered in the population-based digestive cancer registry of Burgundy (France). We calculated conditional 5-year net survival, using the Pohar Perme estimator, for every additional year survived after diagnosis from 1 to 5 years. The initial 5-year net survival estimates varied between 89% for stage I and 9% for advanced stage cancer. The corresponding 5-year net survival for patients alive after 5 years was 95% and 75%. Stage II and III patients who survived 5 years had a similar probability of surviving 5 more years, respectively 87% and 84%. For survivors after the first year following diagnosis, five-year conditional net survival was similar regardless of age class and period of diagnosis. For colorectal cancer survivors, conditional net survival provides relevant and complementary prognostic information for patients and clinicians. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Monophasic versus biphasic defibrillation for pediatric out-of-hospital cardiac arrest patients: a nationwide population-based study in Japan

PubMed Central

2012-01-01

Introduction Conventional monophasic defibrillators for out-of-hospital cardiac-arrest patients have been replaced with biphasic defibrillators. However, the advantage of biphasic over monophasic defibrillation for pediatric out-of-hospital cardiac-arrest patients remains unknown. This study aimed to compare the survival outcomes of pediatric out-of-hospital cardiac-arrest patients who underwent monophasic defibrillation with those who underwent biphasic defibrillation. Methods This prospective, nationwide, population-based observational study included pediatric out-of-hospital cardiac-arrest patients from January 1, 2005, to December 31, 2009. The primary outcome measure was survival at 1 month with minimal neurologic impairment. The secondary outcome measures were survival at 1 month and the return of spontaneous circulation before hospital arrival. Multivariable logistic regression analysis was performed to identify the independent association between defibrillator type (monophasic or biphasic) and outcomes. Results Among 5,628 pediatric out-of-hospital cardiac-arrest patients (1 through 17 years old), 430 who received defibrillation shock with monophasic or biphasic defibrillator were analyzed. The number of patients who received defibrillation shock with monophasic defibrillator was 127 (30%), and 303 (70%) received defibrillation shock with biphasic defibrillator. The survival rates at 1 month with minimal neurologic impairment were 17.5% and 24.4%, the survival rates at 1 month were 32.3% and 35.6%, and the rates of return of spontaneous circulation before hospital arrival were 24.4% and 27.4% in the monophasic and biphasic defibrillator groups, respectively. Hierarchic logistic regression analyses by using generalized estimation equations found no significant difference between the two groups in terms of 1-month survival with minimal neurologic impairment (odds ratio (OR), 1.57; 95% confidence interval (CI), 0.87 to 2.83; P = 0.14) and 1-month survival (OR, 1.38; 95% CI, 0.87 to 2.18; P = 0.17). Conclusions The present nationwide population-based observational study could not confirm an advantage of biphasic over monophasic defibrillators for pediatric OHCA patients. PMID:23148767

Demography of a breeding population of whimbrel (Numenius phaeopus) near Churchill, Manitoba, Canada

NASA Astrophysics Data System (ADS)

Perz, Johanna

I used a GIS raster layer of an area in the Churchill, Manitoba region to investigate the effect of breeding habitat on demography and density of Whimbrel from 2010 through 2013. Program MARK was used to quantify adult and daily nest survival. Apparent annual survival of 0.73 +/- 0.06 SE (95% CI = 0.60-0.83) did not significantly differ between sexes or habitats and was lower than expected based on longevity records and estimates for other large-bodied shorebirds. Nest success, corrected for exposure days, was highly variable, ranging from a low of 3% (95% CI = 0-12%) in 2011 to a high of 71% (95% CI = 54-83%) in 2013. The highest rate of nest survival occurred in the spring with the warmest mean temperature. I developed a generalized linear model (GLM) with a negative-binomial distribution from random plots that were surveyed for abundance to extrapolate a local breeding population size of 410 +/- 230 SE and density of 3.2 birds per square km +/- 1.8 SE. The result of my study suggests that other aspects of habitat not captured by the land cover categories may be more important to population dynamics.

Integrating copper toxicity and climate change to understand extinction risk to two species of pond-breeding anurans.

PubMed

Weir, Scott M; Scott, David E; Salice, Christopher J; Lance, Stacey L

2016-09-01

Chemical contamination is often suggested as an important contributing factor to amphibian population declines, but direct links are rarely reported. Population modeling provides a quantitative method to integrate toxicity data with demographic data to understand the long-term effects of contaminants on population persistence. In this study we use laboratory-derived embryo and larval toxicity data for two anuran species to investigate the potential for toxicity to contribute to population declines. We use the southern toad (Anaxyrus terrestris) and the southern leopard frog (Lithobates sphenocephalus) as model species to investigate copper (Cu) toxicity. We use matrix models to project populations through time and quantify extinction risk (the probability of quasi-extinction in 35 yr). Life-history parameters for toads and frogs were obtained from previously published literature or unpublished data from a long-term (>35 yr) data set. In addition to Cu toxicity, we investigate the role of climate change on amphibian populations by including the probability of early pond drying that results in catastrophic reproductive failure (CRF, i.e., complete mortality of all larval individuals). Our models indicate that CRF is an important parameter for both species as both were unable to persist when CRF probability was >50% for toads or 40% for frogs. Copper toxicity alone did not result in significant effects on extinction risk unless toxicity was very high (>50% reduction in survival parameters). For toads, Cu toxicity and high probability of CRF both resulted in high extinction risk but no synergistic (or greater than additive) effects between the two stressors occurred. For leopard frogs, in the absence of CRF survival was high even under Cu toxicity, but with CRF Cu toxicity increased extinction risk. Our analyses highlight the importance of considering multiple stressors as well as species differences in response to those stressors. Our models were consistently most sensitive to juvenile and adult survival, further suggesting the importance of terrestrial stages to population persistence. Future models will incorporate multiple wetlands with different combinations of stressors to understand if our results for a single wetland result in a population sink within the landscape. © 2016 by the Ecological Society of America.

Gastrointestinal malignancies: when does race matter?

PubMed

Fitzgerald, Timothy L; Bradley, Cathy J; Dahman, Bassam; Zervos, Emmanuel E

2009-11-01

African Americans have a poorer survival from gastrointestinal cancers. We hypothesized that socioeconomic status may explain much of this disparity. Four years of population-based Medicare and Medicaid administrative claims files were merged with the Michigan Tumor Registry. Data were identified for 18,260 patients with colorectal (n = 13,001), pancreatic (n = 2,427), gastric (n = 1,739), and esophageal (n = 1,093) cancer. Three outcomes were studied: the likelihood of late stage diagnosis, the likelihood of surgery after diagnosis, and survival. Bivariate analysis was used to compare stage and operation between African-American and Caucasian patients. Cox proportional hazard models were used to evaluate differences in survival. Statistical significance was defined as p < 0.05. In unadjusted analyses, relative to Caucasian patients, African-American patients with colorectal and esophageal cancer were more likely to present with metastatic disease, were less likely to have surgery, and were less likely to survive during the study period (p < 0.05). In a multivariate analysis, African-American patients had a higher likelihood of death from colorectal cancer than Caucasian patients. This difference, however, did not persist when late stage and surgery were taken into account (hazard ratio = 1.15, 95% CI = 1.06 to 1.24). No racial differences in survival were observed among patients with esophagus, gastric, or pancreatic cancer. These data suggest that improvements in screening and rates of operation may reduce differences in colorectal cancer outcomes between African-American and Caucasian patients. But race has little influence on survival of patients with pancreatic, esophageal, or gastric cancer.

Antagonistic effect of helpers on breeding male and female survival in a cooperatively breeding bird

PubMed Central

Paquet, Matthieu; Doutrelant, Claire; Hatchwell, Ben J; Spottiswoode, Claire N; Covas, Rita

2015-01-01

1. Cooperatively breeding species are typically long lived and hence, according to theory, are expected to maximize their lifetime reproductive success through maximizing survival. Under these circumstances, the presence of helpers could be used to lighten the effort of current reproduction for parents to achieve higher survival. 2. In addition, individuals of different sexes and ages may follow different strategies, but whether male and female breeders and individuals of different ages benefit differently from the presence of helpers has often been overlooked. Moreover, only one study that investigated the relationship between parental survival and the presence of helpers used capture–mark–recapture analyses (CMR). These methods are important since they allow us to account for the non-detection of individuals that are alive in the population but not detected, and thus, the effects on survival and recapture probability to be disentangled. 3. Here, we used multi-event CMR methods to investigate whether the number of helpers was associated with an increase in survival probability for male and female breeders of different ages in the sociable weaver Philetairus socius. In this species, both sexes reduce their feeding rate in the presence of helpers. We therefore predicted that the presence of helpers should increase the breeders' survival in both sexes, especially early in life when individuals potentially have more future breeding opportunities. In addition, sociable weaver females reduce their investment in eggs in the presence of helpers, so we predicted a stronger effect of helpers on female than male survival. 4. As expected we found that females had a higher survival probability when breeding with more helpers. Unexpectedly, however, male survival probability decreased with increasing number of helpers. This antagonistic effect diminished as the breeders grew older. 5. These results illustrate the complexity of fitness costs and benefits underlying cooperative behaviours and how these may vary with the individuals' sex and age. They also highlight the need for further studies on the sex-specific effects of helpers on survival. PMID:25850564

Genetic Introgression and the Survival of Florida Panther Kittens

PubMed Central

Hostetler, Jeffrey A.; Onorato, David P.; Nichols, James D.; Johnson, Warren E.; Roelke, Melody E.; O’Brien, Stephen J.; Jansen, Deborah; Oli, Madan K.

2010-01-01

Estimates of survival for the young of a species are critical for population models. These models can often be improved by determining the effects of management actions and population abundance on this demographic parameter. We used multiple sources of data collected during 1982-2008 and a live recapture-dead recovery modeling framework to estimate and model survival of Florida panther (Puma concolor coryi) kittens (age 0 – 1 year). Overall, annual survival of Florida panther kittens was 0.323 ± 0.071 (SE), which was lower than estimates used in previous population models. In 1995, female pumas from Texas (P. c. stanleyana) were released into occupied panther range as part of an intentional introgression program to restore genetic variability. We found that kitten survival generally increased with degree of admixture: F1 admixed and backcrossed to Texas kittens survived better than canonical Florida panther and backcrossed to canonical kittens. Average heterozygosity positively influenced kitten and older panther survival, whereas index of panther abundance negatively influenced kitten survival. Our results provide strong evidence for the positive population-level impact of genetic introgression on Florida panthers. Our approach to integrate data from multiple sources was effective at improving robustness as well as precision of estimates of Florida panther kitten survival, and can be useful in estimating vital rates for other elusive species with sparse data. PMID:21113436

Genetic introgression and the survival of Florida panther kittens

USGS Publications Warehouse

Hostetler, Jeffrey A.; Onorato, David P.; Nichols, James D.; Johnson, Warren E.; Roelke, Melody E.; O'Brien, Stephen J.; Jansen, Deborah; Oli, Madan K.

2010-01-01

Estimates of survival for the young of a species are critical for population models. These models can often be improved by determining the effects of management actions and population abundance on this demographic parameter. We used multiple sources of data collected during 1982–2008 and a live-recapture dead-recovery modeling framework to estimate and model survival of Florida panther (Puma concolor coryi) kittens (age 0–1 year). Overall, annual survival of Florida panther kittens was 0.323 ± 0.071 (SE), which was lower than estimates used in previous population models. In 1995, female pumas from Texas (P. c. stanleyana) were released into occupied panther range as part of an intentional introgression program to restore genetic variability. We found that kitten survival generally increased with degree of admixture: F1 admixed and backcrossed to Texas kittens survived better than canonical Florida panther and backcrossed to canonical kittens. Average heterozygosity positively influenced kitten and older panther survival, whereas index of panther abundance negatively influenced kitten survival. Our results provide strong evidence for the positive population-level impact of genetic introgression on Florida panthers. Our approach to integrate data from multiple sources was effective at improving robustness as well as precision of estimates of Florida panther kitten survival, and can be useful in estimating vital rates for other elusive species with sparse data.

Cardiopulmonary resuscitation of out-of-hospital traumatic cardiac arrest in Qatar: A nationwide population-based study.

PubMed

Irfan, Furqan B; Consunji, Rafael; El-Menyar, Ayman; George, Pooja; Peralta, Ruben; Al-Thani, Hassan; Thomas, Stephen Hodges; Alinier, Guillaume; Shuaib, Ashfaq; Al-Suwaidi, Jassim; Singh, Rajvir; Castren, Maaret; Cameron, Peter A; Djarv, Therese

2017-08-01

Traumatic cardiac arrest studies have reported improved survival rates recently, ranging from 1.7-7.5%. This population-based nationwide study aims to describe the epidemiology, interventions and outcomes, and determine predictors of survival from out-of-hospital traumatic cardiac arrest (OHTCA) in Qatar. An observational retrospective population-based study was conducted on OHTCA patients in Qatar, from January 2010 to December 2015. Traumatic cardiac arrest was redefined to include out-of-hospital traumatic cardiac arrest (OHTCA) and in-hospital traumatic cardiac arrest (IHTCA). A total of 410 OHTCA patients were included in the 6-year study period. The mean annual crude incidence rate of OHTCA was 4.0 per 100,000 population, in Qatar. OHTCA mostly occurred in males with a median age of 33. There was a preponderance of blunt injuries (94.3%) and head injuries (66.3%). Overall, the survival rate was 2.4%. Shockable rhythm, prehospital external hemorrhage control, in-hospital blood transfusion, and surgery were associated with higher odds of survival. Adrenaline (Epinephrine) lowered the odds of survival. The incidence of OHTCA was less than expected, with a low rate of survival. Thoracotomy was not associated with improved survival while Adrenaline administration lowered survival in OHTCA patients with majority blunt injuries. Interventions to enable early prehospital control of hemorrhage, blood transfusion, thoracostomy and surgery improved survival. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of harvesting pressure on demographic tactics: Implications for wildlife management

USGS Publications Warehouse

Servanty, S.; Gaillard, J.-M.; Ronchi, F.; Focardi, S.; Baubet, E.; Gimenez, O.

2011-01-01

Demographic tactics within animal populations are shaped by selective pressures. Exploitation exerts additional pressures so that differing demographic tactics might be expected among populations with differences in levels of exploitation. Yet little has been done so far to assess the possible consequences of exploitation on the demographic tactics of mammals, even though such information could influence the choice of effective management strategies. Compared with similar-sized ungulate species, wild boar Sus scrofa has high reproductive capabilities, which complicates population management. Using a perturbation analysis, we investigated how population growth rates (??) and critical life-history stages differed between two wild boar populations monitored for several years, one of which was heavily harvested and the other lightly harvested. Asymptotic ?? was 1??242 in the lightly hunted population and 1??115 in the heavily hunted population, while the ratio between the elasticity of adult survival and juvenile survival was 2??63 and 1??27, respectively. A comparative analysis including 21 other ungulate species showed that the elasticity ratio in the heavily hunted population was the lowest ever observed. Compared with expected generation times of similar-sized ungulates (more than 6years), wild boar has a fast life-history speed, especially when facing high hunting pressure. This is well illustrated by our results, where generation times were 3??6years in the lightly hunted population and only 2??3years in the heavily hunted population. High human-induced mortality combined with non-limiting food resources accounted for the accelerated life history of the hunted population because of earlier reproduction. Synthesis and applications. For wild boar, we show that when a population is facing a high hunting pressure, increasing the mortality in only one age-class (e.g. adults or juveniles) may not allow managers to limit population growth. We suggest that simulations of management strategies based on context-specific demographic models are useful for selecting interventions for population control. This type of approach allows the assessment of population response to exploitation by considering a range of plausible scenarios, improving the chance of selecting appropriate management actions. ?? 2011 The Authors. Journal of Applied Ecology ?? 2011 British Ecological Society.

Multiple interactions and rapidity gap survival

NASA Astrophysics Data System (ADS)

Khoze, V. A.; Martin, A. D.; Ryskin, M. G.

2018-05-01

Observations of rare processes containing large rapidity gaps at high energy colliders may be exceptionally informative. However the cross sections of these events are small in comparison with that for the inclusive processes since there is a large probability that the gaps may be filled by secondary particles arising from additional soft interactions or from gluon radiation. Here we review the calculations of the probability that the gaps survive population by particles from these effects for a wide range of different processes.

Single Versus Double Lung Retransplantation Does Not Affect Survival Based on Previous Transplant Type.

PubMed

Schumer, Erin M; Rice, Jonathan D; Kistler, Amanda M; Trivedi, Jaimin R; Black, Matthew C; Bousamra, Michael; van Berkel, Victor

2017-01-01

Survival following retransplantation with a single lung is worse than after double lung transplant. We sought to characterize survival of patients who underwent lung retransplantation based on the type of their initial transplant, single or double. The United Network for Organ Sharing database was queried for adult patients who underwent lung retransplantation from 2005 onward. Patients were excluded if they underwent more than one retransplantation. The patient population was divided into 4 groups based on first followed by second transplant type, respectively: single then single, double then single, double then double, and single then double. Descriptive analysis and Kaplan-Meier survival analysis were performed. A p value less than 0.05 was considered significant. A total of 410 patients underwent retransplantation in the study time period. Overall mean survival for all patients who underwent retransplantation was 1,213 days. Kaplan-Meier survival analysis demonstrated no difference in graft survival between the 4 study groups (p = 0.146). There was no significant difference in graft survival between recipients of retransplant with single or double lungs when stratified by previous transplant type. These results suggest that when retransplantation is performed, single lung retransplantation should be considered, regardless of previous transplant type, in an effort to maximize organ resources. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

White-nose syndrome survivors do not exhibit frequent arousals associated with Pseudogymnoascus destructans infection.

PubMed

Lilley, Thomas Mikael; Johnson, Joseph Samuel; Ruokolainen, Lasse; Rogers, Elisabeth Jeannine; Wilson, Cali Ann; Schell, Spencer Mead; Field, Kenneth Alan; Reeder, DeeAnn Marie

2016-01-01

White-nose syndrome (WNS) has devastated bat populations in North America, with millions of bats dead. WNS is associated with physiological changes in hibernating bats, leading to increased arousals from hibernation and premature consumption of fat reserves. However, there is evidence of surviving populations of little brown myotis (Myotis lucifugus) close to where the fungus was first detected nearly ten years ago. We examined the hibernation patterns of a surviving population of little brown myotis and compared them to patterns in populations before the arrival of WNS and populations at the peak of WNS mortality. Despite infection with Pseudogymnoascus destructans, the causative fungal agent, the remnant population displayed less frequent arousals from torpor and lower torpid body temperatures than bats that died from WNS during the peak of mortality. The hibernation patterns of the remnant population resembled pre-WNS patterns with some modifications. These data show that remnant populations of little brown myotis do not experience the increase in periodic arousals from hibernation typified by bats dying from WNS, despite the presence of the fungal pathogen on their skin. These patterns may reflect the use of colder hibernacula microclimates by WNS survivors, and/or may reflect differences in how these bats respond to the disease.

Impact of biology knowledge on the conservation and management of large pelagic sharks.

PubMed

Yokoi, Hiroki; Ijima, Hirotaka; Ohshimo, Seiji; Yokawa, Kotaro

2017-09-06

Population growth rate, which depends on several biological parameters, is valuable information for the conservation and management of pelagic sharks, such as blue and shortfin mako sharks. However, reported biological parameters for estimating the population growth rates of these sharks differ by sex and display large variability. To estimate the appropriate population growth rate and clarify relationships between growth rate and relevant biological parameters, we developed a two-sex age-structured matrix population model and estimated the population growth rate using combinations of biological parameters. We addressed elasticity analysis and clarified the population growth rate sensitivity. For the blue shark, the estimated median population growth rate was 0.384 with a range of minimum and maximum values of 0.195-0.533, whereas those values of the shortfin mako shark were 0.102 and 0.007-0.318, respectively. The maturity age of male sharks had the largest impact for blue sharks, whereas that of female sharks had the largest impact for shortfin mako sharks. Hypotheses for the survival process of sharks also had a large impact on the population growth rate estimation. Both shark maturity age and survival rate were based on ageing validation data, indicating the importance of validating the quality of these data for the conservation and management of large pelagic sharks.

Nymphal survival and habitat distribution of Ixodes scapularis and Amblyomma americanum ticks (Acari:Ixodidae) on Fire Island, New York

USGS Publications Warehouse

Ginsberg, H.S.; Zhioua, E.

1996-01-01

The distribution and survival of Ixodes scapularis and Amblyomma americanum were studied in deciduous and coniferous wooded habitats and in open habitats on Fire Island, New York, USA. The survival of nymphal I. scapularis in field enclosures was greater in forests than in open habitats, suggesting that greater survival contributes to the higher tick population in the woods. The nymphs of each species were more common in deciduous thickets (predominantly Aronia arbutifolia and Vaccinium corynbosum) than in coniferous woods (mostly Pinus rigida) in most but not all years. Larval I. scapularis were more common in coniferous sites in 1994, while the same ticks, as nymphs, were more common in deciduous sites in 1995. The survival of the nymphs was not consistently greater in either the deciduous or coniferous woods. Therefore, factors other than nymphal survival (e.g. larval overwintering survival and tick movement on hosts) probably influenced the relative nymph abundance in different forest types. Overall, the survival of A. americanum was far higher than that of I. scapularis.

The impact of roads on the demography of grizzly bears in Alberta.

PubMed

Boulanger, John; Stenhouse, Gordon B

2014-01-01

One of the principal factors that have reduced grizzly bear populations has been the creation of human access into grizzly bear habitat by roads built for resource extraction. Past studies have documented mortality and distributional changes of bears relative to roads but none have attempted to estimate the direct demographic impact of roads in terms of both survival rates, reproductive rates, and the interaction of reproductive state of female bears with survival rate. We applied a combination of survival and reproductive models to estimate demographic parameters for threatened grizzly bear populations in Alberta. Instead of attempting to estimate mean trend we explored factors which caused biological and spatial variation in population trend. We found that sex and age class survival was related to road density with subadult bears being most vulnerable to road-based mortality. A multi-state reproduction model found that females accompanied by cubs of the year and/or yearling cubs had lower survival rates compared to females with two year olds or no cubs. A demographic model found strong spatial gradients in population trend based upon road density. Threshold road densities needed to ensure population stability were estimated to further refine targets for population recovery of grizzly bears in Alberta. Models that considered lowered survival of females with dependant offspring resulted in lower road density thresholds to ensure stable bear populations. Our results demonstrate likely spatial variation in population trend and provide an example how demographic analysis can be used to refine and direct conservation measures for threatened species.

The Impact of Roads on the Demography of Grizzly Bears in Alberta

PubMed Central

2014-01-01

One of the principal factors that have reduced grizzly bear populations has been the creation of human access into grizzly bear habitat by roads built for resource extraction. Past studies have documented mortality and distributional changes of bears relative to roads but none have attempted to estimate the direct demographic impact of roads in terms of both survival rates, reproductive rates, and the interaction of reproductive state of female bears with survival rate. We applied a combination of survival and reproductive models to estimate demographic parameters for threatened grizzly bear populations in Alberta. Instead of attempting to estimate mean trend we explored factors which caused biological and spatial variation in population trend. We found that sex and age class survival was related to road density with subadult bears being most vulnerable to road-based mortality. A multi-state reproduction model found that females accompanied by cubs of the year and/or yearling cubs had lower survival rates compared to females with two year olds or no cubs. A demographic model found strong spatial gradients in population trend based upon road density. Threshold road densities needed to ensure population stability were estimated to further refine targets for population recovery of grizzly bears in Alberta. Models that considered lowered survival of females with dependant offspring resulted in lower road density thresholds to ensure stable bear populations. Our results demonstrate likely spatial variation in population trend and provide an example how demographic analysis can be used to refine and direct conservation measures for threatened species. PMID:25532035

Cell populations can use aneuploidy to survive telomerase insufficiency

PubMed Central

Millet, Caroline; Ausiannikava, Darya; Le Bihan, Thierry; Granneman, Sander; Makovets, Svetlana

2015-01-01

Telomerase maintains ends of eukaryotic chromosomes, telomeres. Telomerase loss results in replicative senescence and a switch to recombination-dependent telomere maintenance. Telomerase insufficiency in humans leads to telomere syndromes associated with premature ageing and cancer predisposition. Here we use yeast to show that the survival of telomerase insufficiency differs from the survival of telomerase loss and occurs through aneuploidy. In yeast grown at elevated temperatures, telomerase activity becomes limiting: haploid cell populations senesce and generate aneuploid survivors—near diploids monosomic for chromosome VIII. This aneuploidy results in increased levels of the telomerase components TLC1, Est1 and Est3, and is accompanied by decreased abundance of ribosomal proteins. We propose that aneuploidy suppresses telomerase insufficiency through redistribution of cellular resources away from ribosome synthesis towards production of telomerase components and other non-ribosomal proteins. The aneuploidy-induced re-balance of the proteome via modulation of ribosome biogenesis may be a general adaptive response to overcome functional insufficiencies. PMID:26489519

Model structure of the stream salmonid simulator (S3)—A dynamic model for simulating growth, movement, and survival of juvenile salmonids

USGS Publications Warehouse

Perry, Russell W.; Plumb, John M.; Jones, Edward C.; Som, Nicholas A.; Hetrick, Nicholas J.; Hardy, Thomas B.

2018-04-06

Fisheries and water managers often use population models to aid in understanding the effect of alternative water management or restoration actions on anadromous fish populations. We developed the Stream Salmonid Simulator (S3) to help resource managers evaluate the effect of management alternatives on juvenile salmonid populations. S3 is a deterministic stage-structured population model that tracks daily growth, movement, and survival of juvenile salmon. A key theme of the model is that river flow affects habitat availability and capacity, which in turn drives density dependent population dynamics. To explicitly link population dynamics to habitat quality and quantity, the river environment is constructed as a one-dimensional series of linked habitat units, each of which has an associated daily time series of discharge, water temperature, and usable habitat area or carrying capacity. The physical characteristics of each habitat unit and the number of fish occupying each unit, in turn, drive survival and growth within each habitat unit and movement of fish among habitat units.The purpose of this report is to outline the underlying general structure of the S3 model that is common among different applications of the model. We have developed applications of the S3 model for juvenile fall Chinook salmon (Oncorhynchus tshawytscha) in the lower Klamath River. Thus, this report is a companion to current application of the S3 model to the Trinity River (in review). The general S3 model structure provides a biological and physical framework for the salmonid freshwater life cycle. This framework captures important demographics of juvenile salmonids aimed at translating management alternatives into simulated population responses. Although the S3 model is built on this common framework, the model has been constructed to allow much flexibility in application of the model to specific river systems. The ability for practitioners to include system-specific information for the physical stream structure, survival, growth, and movement processes ensures that simulations provide results that are relevant to the questions asked about the population under study.

Rectal cancer survival in the United States by race and stage, 2001 to 2009: Findings from the CONCORD-2 study.

PubMed

Joseph, Djenaba A; Johnson, Chris J; White, Arica; Wu, Manxia; Coleman, Michel P

2017-12-15

In the first CONCORD study, 5-year survival for patients with diagnosed with rectal cancer between 1990 and 1994 was <60%, with large racial disparities noted in the majority of participating states. We have updated these findings to 2009 by examining population-based survival by stage of disease at the time of diagnosis, race, and calendar period. Data from the CONCORD-2 study were used to compare survival among individuals aged 15 to 99 years who were diagnosed in 37 states encompassing up to 80% of the US population. We estimated net survival up to 5 years after diagnosis correcting for background mortality with state-specific and race-specific life table. Survival estimates were age-standardized with the International Cancer Survival Standard weights. We present survival estimates by race (all, black, and white) for 2001 through 2003 and 2004 through 2009 to account for changes in collecting the data for Surveillance, Epidemiology, and End Results Summary Stage 2000. There was a small increase in 1-year, 3-year, and 5-year net survival between 2001-2003 (84.6%, 70.7%, and 63.2%, respectively), and 2004-2009 (85.1%, 71.5%, and 64.1%, respectively). Black individuals were found to have lower 1-year, 3-year, and 5-year survival than white individuals in both periods; the absolute difference in survival between black and white individuals declined only for 5-year survival. Black patients had lower 5-year survival than whites at each stage at the time of diagnosis in both time periods. There was little improvement noted in net survival for patients with rectal cancer, with persistent disparities noted between black and white individuals. Additional investigation is needed to identify and implement effective interventions to ensure the consistent and equitable use of high-quality screening, diagnosis, and treatment to improve survival for patients with rectal cancer. Cancer 2017;123:5037-58. Published 2017. This article is a U.S. Government work and is in the public domain in the USA. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Escherichia coli Survival in, and Release from, White-Tailed Deer Feces

PubMed Central

Fry, Jessica; Ives, Rebecca L.; Rose, Joan B.

2014-01-01

White-tailed deer are an important reservoir for pathogens that can contribute a large portion of microbial pollution in fragmented agricultural and forest landscapes. The scarcity of experimental data on survival of microorganisms in and release from deer feces makes prediction of their fate and transport less reliable and development of efficient strategies for environment protection more difficult. The goal of this study was to estimate parameters for modeling Escherichia coli survival in and release from deer (Odocoileus virginianus) feces. Our objectives were as follows: (i) to measure survival of E. coli in deer pellets at different temperatures, (ii) to measure kinetics of E. coli release from deer pellets at different rainfall intensities, and (iii) to estimate parameters of models describing survival and release of microorganisms from deer feces. Laboratory experiments were conducted to study E. coli survival in deer pellets at three temperatures and to estimate parameters of Chick's exponential model with temperature correction based on the Arrhenius equation. Kinetics of E. coli release from deer pellets were measured at two rainfall intensities and used to derive the parameters of Bradford-Schijven model of bacterial release. The results showed that parameters of the survival and release models obtained for E. coli in this study substantially differed from those obtained by using other source materials, e.g., feces of domestic animals and manures. This emphasizes the necessity of comprehensive studies of survival of naturally occurring populations of microorganisms in and release from wildlife animal feces in order to achieve better predictions of microbial fate and transport in fragmented agricultural and forest landscapes. PMID:25480751

Sex differences in the consequences of early-life exposure to epidemiological stress--a life-history approach.

PubMed

Störmer, Charlotte

2011-01-01

Exposure to infectious disease in early life has been suggested to have a negative effect on later-life survival,possibly through the induction of inflammatory responses. Although a life-course perspective emphasizes the importance of both survival and reproduction for individual fitness, to date, no studies have investigated whether early-life exposure to infectious disease has an impact on reproduction as it has been suggested for later survival. To address this question, I have used family reconstitution data from a historical (18th and 19th century) human population in the Krummhörn (Germany) comparing survival and reproduction between an exposed and a non-exposed group. The exposed group comprised those exposed to a high-infectious disease load during prenatal and early postnatal development. The results show a marked sex difference in the impact of early-life exposure to infectious disease. Exposed females show no effect on their life expectancy but significantly reduced fertility (number of children). For exposed males, however, the effect on survival is opponent over time: mortality is increased during childhood but decreased in late adulthood. Above that, exposed males reproduce earlier and have a smaller proportion of surviving children. This study does not support former studies indicating a negative association between early-life disease load and later survival. I argue that due to differences in male and female life strategies, males in general are more vulnerable especially early in life. Hence, adverse environmental conditions may have a stronger effect on male survivability and reproductive performance.

Double lung transplants have significantly improved survival compared with single lung transplants in high lung allocation score patients.

PubMed

Black, Matthew C; Trivedi, Jaimin; Schumer, Erin M; Bousamra, Michael; van Berkel, Victor

2014-11-01

Historically, double lung transplantation survival rates are higher than those of single lung transplantation, but in critically ill patients a single lung transplant, with less associated operative morbidity, could afford a better outcome. This article evaluates how survival is affected in patients who have a high lung allocation score (LAS) and receive a single versus a double lung transplant. The UNOS Thoracic Transplant Database for lung transplants from January 2005 to June 2012 was used for analysis. Propensity matching was used to minimize differences between the high and low LAS groups and between single and double lung transplants in the high LAS group. Within this database, there were 8,778 patients, of whom 8,050 had an LAS less than 75 and 728 had an LAS greater than or equal to 75. Kaplan-Meier survival curves stratified by high and low LAS, and by single versus double lung transplants, showed a marked decrease in survival (p<0.001) in those with a high LAS who received a single lung transplant when compared with those with a high LAS who received a double lung transplant. This was a much greater difference in survival than was present in the low LAS patient population. Despite a higher operative morbidity, patients who had a high LAS did substantially better in terms of survival if two lungs were transplanted rather than only one, with a larger difference in survival than for patients with a lower LAS. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Developing population models with data from marked individuals

USGS Publications Warehouse

Hae Yeong Ryu,; Kevin T. Shoemaker,; Eva Kneip,; Anna Pidgeon,; Patricia Heglund,; Brooke Bateman,; Thogmartin, Wayne E.; Reşit Akçakaya,

2016-01-01

Population viability analysis (PVA) is a powerful tool for biodiversity assessments, but its use has been limited because of the requirements for fully specified population models such as demographic structure, density-dependence, environmental stochasticity, and specification of uncertainties. Developing a fully specified population model from commonly available data sources – notably, mark–recapture studies – remains complicated due to lack of practical methods for estimating fecundity, true survival (as opposed to apparent survival), natural temporal variability in both survival and fecundity, density-dependence in the demographic parameters, and uncertainty in model parameters. We present a general method that estimates all the key parameters required to specify a stochastic, matrix-based population model, constructed using a long-term mark–recapture dataset. Unlike standard mark–recapture analyses, our approach provides estimates of true survival rates and fecundities, their respective natural temporal variabilities, and density-dependence functions, making it possible to construct a population model for long-term projection of population dynamics. Furthermore, our method includes a formal quantification of parameter uncertainty for global (multivariate) sensitivity analysis. We apply this approach to 9 bird species and demonstrate the feasibility of using data from the Monitoring Avian Productivity and Survivorship (MAPS) program. Bias-correction factors for raw estimates of survival and fecundity derived from mark–recapture data (apparent survival and juvenile:adult ratio, respectively) were non-negligible, and corrected parameters were generally more biologically reasonable than their uncorrected counterparts. Our method allows the development of fully specified stochastic population models using a single, widely available data source, substantially reducing the barriers that have until now limited the widespread application of PVA. This method is expected to greatly enhance our understanding of the processes underlying population dynamics and our ability to analyze viability and project trends for species of conservation concern.

Population density predicts outcome from out-of-hospital cardiac arrest in Victoria, Australia.

PubMed

Nehme, Ziad; Andrew, Emily; Cameron, Peter A; Bray, Janet E; Bernard, Stephen A; Meredith, Ian T; Smith, Karen

2014-05-05

To examine the impact of population density on incidence and outcome of out-of-hospital cardiac arrest (OHCA). Data were extracted from the Victorian Ambulance Cardiac Arrest Registry for all adult OHCA cases of presumed cardiac aetiology attended by the emergency medical service (EMS) between 1 January 2003 and 31 December 2011. Cases were allocated into one of five population density groups according to their statistical local area: very low density (≤ 10 people/km(2)), low density (11-200 people/km(2)), medium density (201-1000 people/km(2)), high density (1001-3000 people/km(2)), and very high density (> 3000 people/km(2)). Survival to hospital and survival to hospital discharge. The EMS attended 27 705 adult presumed cardiac OHCA cases across 204 Victorian regions. In 12 007 of these (43.3%), resuscitation was attempted by the EMS. Incidence was lower and arrest characteristics were consistently less favourable for lower population density groups. Survival outcomes, including return of spontaneous circulation, survival to hospital and survival to hospital discharge, were significantly poorer in less densely populated groups (P < 0.001 for all comparisons). When compared with very low density populations, the risk-adjusted odds ratios of surviving to hospital discharge were: low density, 1.88 (95% CI, 1.15-3.07); medium density, 2.49 (95% CI, 1.55-4.02); high density, 3.47 (95% CI, 2.20-5.48) and very high density, 4.32 (95% CI, 2.67-6.99). Population density is independently associated with survival after OHCA, and significant variation in the incidence and characteristics of these events are observed across the state.

Survival probability for a diffusive process on a growing domain

NASA Astrophysics Data System (ADS)

Simpson, Matthew J.; Sharp, Jesse A.; Baker, Ruth E.

2015-04-01

We consider the motion of a diffusive population on a growing domain, 0

Functional Response and Matrix Population Model of Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae) fed on Chrysomya putoria (Wiedemann, 1818) (Diptera: Calliphoridae) as Alternative Prey.

PubMed

Botteon, V W; Neves, J A; Godoy, W A C

2017-04-01

Among the predators with high potential for use in biological control, the species of the genus Podisus (Hemiptera: Pentatomidae) have received special attention for laboratory rearing, since they feed on different agricultural and forestry pest insects. However, the type of diet offered to insects in the laboratory may affect the viability of populations, expressed essentially by demographic parameters such as survival and fecundity. This study assessed demographic and development aspects in experimental populations of Podisus nigrispinus (Dallas, 1851) fed on larvae of Chrysomya putoria (Wiedemann, 1818) (Diptera: Calliphoridae) as an alternative prey. The demographic parameters fecundity and survival were investigated in life stages of P. nigrispinus with ecological modeling, by applying the Leslie matrix population model, producing histograms of life stages in successive time steps. The functional response of P. nigrispinus was also investigated on seven densities of C. putoria third-instar larvae at 24 and 48 h. The survival of predators that reached adulthood was 65% and the development time from egg to adult was 23.15 days. The predator showed a type III functional response for consumption of C. putoria at 24 and 48 h. The Leslie-matrix simulation of the age structure provided perpetuation of the predator population over time steps and the prey proved to be feasible for use in rearing and maintenance of P. nigrispinus in the laboratory.

Survival of asbestos insulation workers with mesothelioma.

PubMed Central

Ribak, J; Selikoff, I J

1992-01-01

Malignant mesothelioma is a lethal disease. It is rare in the general population; however, workers exposed to asbestos suffer significant burdens of the neoplasm. The survival time of 457 consecutive fatal cases of pleural and peritoneal mesothelioma that occurred among 17,800 asbestos insulation workers observed prospectively from 1 January 1967 to 1 January 1987 was studied. Mean survival time from initial presentation of the disease to death was 11.4 months for the pleural mesothelioma patients compared with 7.4 months for the peritoneal group. This difference was statistically significant. Mean survival time from diagnosis to death was shorter for both groups of patients: 8.4 months for pleural mesothelioma v 5.8 months for the peritoneal cases. In conclusion, survival time in mesothelioma patients is short; most die within a year from the onset of the initial symptoms. No effective therapy is yet available. PMID:1419863

Elvis to Eminem: quantifying the price of fame through early mortality of European and North American rock and pop stars.

PubMed

Bellis, Mark A; Hennell, Tom; Lushey, Clare; Hughes, Karen; Tocque, Karen; Ashton, John R

2007-10-01

Rock and pop stars are frequently characterised as indulging in high-risk behaviours, with high-profile deaths amongst such musicians creating an impression of premature mortality. However, studies to date have not quantified differences between mortality experienced by such stars and general populations. This study measures survival rates of famous musicians (n = 1064) from their point of fame and compares them to matched general populations in North America and Europe. We describe and utilise a novel actuarial survival methodology which allows quantification of excess post-fame mortality in pop stars. Individuals from North America and Europe performing on any album in the All-Time Top 1000 albums from the music genres rock, punk, rap, R&B, electronica and new age. From 3 to 25 years post fame, both North American and European pop stars experience significantly higher mortality (more than 1.7 times) than demographically matched populations in the USA and UK, respectively. After 25 years of fame, relative mortality in European (but not North American) pop stars begins to return to population levels. Five-year post-fame survival rates suggest differential mortality between stars and general populations was greater in those reaching fame before 1980. Pop stars can suffer high levels of stress in environments where alcohol and drugs are widely available, leading to health-damaging risk behaviour. However, their behaviour can also influence would-be stars and devoted fans. Collaborations between health and music industries should focus on improving both pop star health and their image as role models to wider populations.

Survival of European patients diagnosed with lymphoid neoplasms in 2000–2002: results of the HAEMACARE project

PubMed Central

Marcos-Gragera, Rafael; Allemani, Claudia; Tereanu, Carmen; De Angelis, Roberta; Capocaccia, Riccardo; Maynadie, Marc; Luminari, Stefano; Ferretti, Stefano; Johannesen, Tom Børge; Sankila, Risto; Karjalainen-Lindsberg, Marja-Liisa; Simonetti, Arianna; Martos, Maria Carmen; Raphaël, Martine; Giraldo, Pilar; Sant, Milena

2011-01-01

Background The European Cancer Registry-based project on hematologic malignancies (HAEMACARE), set up to improve the availability and standardization of data on hematologic malignancies in Europe, used the European Cancer Registry-based project on survival and care of cancer patients (EUROCARE-4) database to produce a new grouping of hematologic neoplasms (defined by the International Classification of Diseases for Oncology, Third Edition and the 2001/2008 World Health Organization classifications) for epidemiological and public health purposes. We analyzed survival for lymphoid neoplasms in Europe by disease group, comparing survival between different European regions by age and sex. Design and Methods Incident neoplasms recorded between 1995 to 2002 in 48 population-based cancer registries in 20 countries participating in EUROCARE-4 were analyzed. The period approach was used to estimate 5-year relative survival rates for patients diagnosed in 2000–2002, who did not have 5 years of follow up. Results The 5-year relative survival rate was 57% overall but varied markedly between the defined groups. Variation in survival within the groups was relatively limited across European regions and less than in previous years. Survival differences between men and women were small. The relative survival for patients with all lymphoid neoplasms decreased substantially after the age of 50. The proportion of ‘not otherwise specified’ diagnoses increased with advancing age. Conclusions This is the first study to analyze survival of patients with lymphoid neoplasms, divided into groups characterized by similar epidemiological and clinical characteristics, providing a benchmark for more detailed analyses. This Europe-wide study suggests that previously noted differences in survival between regions have tended to decrease. The survival of patients with all neoplasms decreased markedly with age, while the proportion of ‘not otherwise specified’ diagnoses increased with advancing age. Thus the quality of diagnostic work-up and care decreased with age, suggesting that older patients may not be receiving optimal treatment. PMID:21330324

Construction of a North American Cancer Survival Index to Measure Progress of Cancer Control Efforts

PubMed Central

Weir, Hannah K; Mariotto, Angela; Wilson, Reda; Nishri, Diane

2017-01-01

Introduction Population-based cancer survival data provide insight into the effectiveness of health care delivery. Comparing survival for all cancer sites combined is challenging, because the primary cancer site and age distribution of patients may differ among areas or change over time. Cancer survival indices (CSIs) are summary measures of survival for cancers of all sites combined and are used in England and Europe to monitor temporal trends and examine geographic differences in survival. We describe the construction of the North American Cancer Survival Index and demonstrate how it can be used to compare survival by geographic area and by race. Methods We used data from 36 US cancer registries to estimate relative survival ratios for people diagnosed with cancer from 2006 through 2012 to create the CSI: the weighted sum of age-standardized, site-specific, relative survival ratios, with weights derived from the distribution of incident cases by sex and primary site from 2006 through 2008. The CSI was calculated for 32 registries for all races, 31 registries for whites, and 12 registries for blacks. Results The survival estimates standardized by age only versus age-, sex-, and site-standardized (CSI) were 64.1% (95% confidence interval [CI], 64.1%–64.2%) and 63.9% (95% CI, 63.8%–63.9%), respectively, for the United States for all races combined. The inter-registry ranges in unstandardized and CSI estimates decreased from 12.3% to 5.0% for whites, and from 5.4% to 3.9% for blacks. We found less inter-registry variation in CSI estimates than in unstandardized all-sites survival estimates, but disparities by race persisted. Conclusions CSIs calculated for different jurisdictions or periods are directly comparable, because they are standardized by age, sex, and primary site. A national CSI could be used to measure temporal progress in meeting public health objectives, such as Healthy People 2030. PMID:28910593