Stage-specific Survival Rates Research Articles

Multifaceted density dependence: Social structure and seasonality effects on Serengeti lion demography.

Interactions between density and environmental conditions have important effects on vital rates and consequently on population dynamics and can take complex pathways in species whose demography is strongly influenced by social context, such as the African lion, Panthera leo. In populations of such species, the response of vital rates to density can vary depending on the social structure (e.g. effects of group size or composition). However, studies assessing density dependence in populations of lions and other social species have seldom considered the effects of multiple socially explicit measures of density, and-more particularly for lions-of nomadic males. Additionally, vital-rate responses to interactions between the environment and various measures of density remain largely uninvestigated. To fill these knowledge gaps, we aimed to understand how a socially and spatially explicit consideration of density (i.e. at the local scale) and its interaction with environmental seasonality affect vital rates of lions in the Serengeti National Park, Tanzania. We used a Bayesian multistate capture-recapture model and Bayesian generalized linear mixed models to estimate lion stage-specific survival and between-stage transition rates, as well as reproduction probability and recruitment, while testing for season-specific effects of density measures at the group and home-range levels. We found evidence for several such effects. For example, resident-male survival increased more strongly with coalition size in the dry season compared with the wet season, and adult-female abundance affected subadult survival negatively in the wet season, but positively in the dry season. Additionally, while our models showed no effect of nomadic males on adult-female survival, they revealed strong effects of nomads on key processes such as reproduction and takeover dynamics. Therefore, our results highlight the importance of accounting for seasonality and social context when assessing the effects of density on vital rates of Serengeti lions and of social species more generally.

Taiwan national lung cancer early detection program for heavy smokers and non-smokers with family history of lung cancer.

8009 Background: Lung cancer incidence in Taiwan has been rising with the epidemiological profiles distinct from Western country. Notably, nonsmoking lung cancers accounts for more than 60% and half of lung cancers were diagnosed in advanced stages. For early detection, a national program is therefore initiated to offer biennial low-dose computed tomography (LDCT) screening for heavy smokers and subjects with lung cancer family history (LCFH). Here, we report basic screening findings, analyze relevant effectiveness in reducing advanced lung cancer, and project the potential benefit of mortality reduction. Methods: Taiwan National Lung Cancer Early Detection Program was launched on July 1, 2022 to offer heavy smokers (30 pack-years) and nonsmokers (including light smokers) with a LCFH aged 45-74 years for female and aged 50-74 years for male. This is a continuous screening program using before and after study design for evaluation. We provided the overall first-year basic screening findings until Dec 31, 2023 and did per protocol analysis of stage II+ cancer reduction in comparison with tumor stage distribution in the year preceding the introduction of the national program. The corresponding findings were presented for subjects with LCFH and heavy smokers. The result for heavy smoker was compared with those per-protocol findings from previous randomized controlled trials. The potential mortality reduction was further projected. Results: A total of 78,000 individuals participated in this program, male 44,381 (56.9%) female 33,619 (43.1%); 31,111 participants (39.9%) were heavy smokers, 43,853 (56.2%) nonsmokers but with a LCFH, and 3,036 (3.9%) had both risk factors. Lung cancer confirmed in 956 subjects by surgery or biopsy, 85.0% were stage 0-1. The lung cancer detection rate was 1.2%. Subjects with a LCFH exhibited a higher detection rate (overall: 1.6%, nonsmokers: 1.7% and light smokers 0.9%) compared to heavy smokers (0.7%) and both (1.1%). Early detection of LDCT led to a statistically significant 77% (51%-89%) of reducing advanced stage of lung cancer, 53% (-3%-78%) reduction for heavy smokers, consistent with the corresponding 36%-64% reduction derived from the NLST trial and the Nelson trial, and 85% (67%-93%) reduction for nonsmokers with a LCFH. The benefit of reducing stage II or severe in conjunction with five-year stage-specific survival rate further projected 55% (10%-78%) of mortality reduction from lung cancer. Conclusions: This is the first large-scale LC screening service enrolling 40% heavy smokers and 60% non-smoker with a LCFH. The potential effectiveness of early detection was demonstrated for both targets. As the results based on per-protocol analysis for heavy smoker were consistent with those of previous evidence-based studies the similar and significant intention-to-treat results as before while waiting for the subsequent follow-up would be expected.

Progress against lung cancer, Denmark, 2008-2022.

There has been marked progress against lung cancer in Denmark. To gain further insight into the different aspects of the improvement, we examined the stage-specific incidence rates, stage-specific survival and mortality rates. We used information from the Danish Lung Cancer Registry on date of diagnosis and clinical stage to calculate age-standardised incidence rates and patient survival by sex, period and stage. Information about age-standardised lung cancer-specific mortality rates by sex and period was extracted from The Danish Health Data Authority. Firstly, the decrease in incidence rates was due to a reduction in the rates of advanced stages. Secondly, there was a gradual increase in survival across all stages, and thirdly, the mortality rates gradually decreased over time. The improvements in survival and mortality from lung cancer were due to decreasing incidence rates of advanced cancer and improvement in survival at all stages of the disease.

Identifying minimum freshwater habitat conditions for an endangered fish using life cycle analysis

AbstractIdentifying the most important factors affecting population growth in animal life cycles is an important tool of species conservation. Delta Smelt (Hypomesus transpacificus), an annual fish endemic to the San Francisco Estuary in California (USA), has been provided legal protection since 1993 but 30 years later exists in a conservation‐reliant state on the brink of extinction. Despite considerable controversies about what factors are most responsible for the species' decline, no population growth rate sensitivity comparisons between the most important factors regulating growth have been done. Nor has anyone attempted to quantitatively identify habitat conditions needed to support positive population growth. We developed a set of stage‐structured population models to link habitat indices regulating recruitment of new generations of fish as they metamorphosed into juveniles and the subsequent survival of those fish over several seasons until they reached adulthood. These models are used to quantify drivers of growth rate variation over 30 years. Several complimentary sensitivity analyses indicated freshwater outflow to the estuary during summer had the largest potential to change population growth. Multiple habitat metrics (e.g., food availability, temperature) influencing recruitment and life stage specific survival rates across different seasons interacted in nonlinear ways to determine habitat conditions and water management targets associated with positive population growth. We discuss the implications for freshwater management, Delta Smelt conservation, and the challenges climate change poses for co‐implementation of these two societal priorities.

Does the ypTNM-stage adequately predict long-term survival rates in gastric cancer patients receiving neoadjuvant chemotherapy followed by radical resection?

Background Following neoadjuvant chemotherapy (NAC) for resectable gastric cancer, the prognostic adequacy of the UICC staging system needs to be investigated. In particular to explore whether the ypTNM curves for radically resected gastric cancer patients receiving NAC follow the stage-matched survival curves of radically resected chemo-naïve patients (pTNM). Further, to disclose any interaction between the TNM-response mode to NAC and stage-specific survival rates, i.e., whether survival for a particular pathological disease stage was dependent on whether this was reached through a downstaging or as stable disease following NAC. Material and methods Retrospective study on radically resected patients ≤ 75 years of age with gastric adenocarcinoma stages I-III diagnosed during 2001–2016. The patients constitute two population-based cohorts; the SURG-group with n = 121 patients treated before 2007 when NAC was introduced, and the NAC-group with n = 126 patients diagnosed since early 2007, receiving NAC and subsequent radical resection. Results Long-term survival rates were similar when specific ypTNM-stages were compared to their corresponding pTNM chemo-naïve counterparts. The dichotomised N0 vs. N + had a substantial impact on the long-term survival rates in both groups, however, no discrepancy in long-term survival rates between pN0 vs. ypN0, and pN + vs. ypN + was found. The pathological stage determined long-term survival rates irrespective of the baseline disease stage, as no interaction between the response mode and stage-specific survival rates was found. Conclusions Survival curves for specific ypTNM-stages following NAC did not differ from the corresponding survival curves of their chemo-naïve pTNM counterparts. The interpretation is that NAC affected the gastric cancer, lymph nodes, and micrometastases, in such a way that the final ypTNM-stage provided similar prognostic information as the chemo-naïve pTNM-stages. Survival rates were contingent on the final ypTNM-stages alone, and not influenced by the response mode to reach that particular disease stage, or predetermined by the original clinical TNM-stage.

Verification of the prognostic precision of the new 2023 FIGO staging system in endometrial cancer patients – An international pooled analysis of three ESGO accredited centres

BackgroundRecently, the new 2023 International Federation of Gynecology and Obstetrics (FIGO) staging system for endometrial cancer (EC) critically integrating new pathological and molecular features was published. The present study evaluated the clinical impact of the new 2023 FIGO staging system by comparing it to the previous 2009 system. MethodsThis is an international, pooled retrospective study of 519 EC patients who underwent primary treatment (and molecular characterisation) at three European Society of Gynaecological Oncology (ESGO) accredited centres in Austria/Italy. Patients were categorised according to the 2009 and the 2023 FIGO staging systems. Stage shifts were analysed and (sub)stage specific 5-year progression-free (PFS) and overall survival (OS) rates were calculated and compared. Different statistical tests were applied to evaluate the prognostic precision of the two FIGO staging systems and to compare them to each other. Results(Sub)stage shifts occurred in 143/519 (27.6%) patients: 123 upshifts (23.7%) and 20 (3.9%) downshifts. 2023 FIGO staging system identified a stage I cohort with a notably higher 5-year PFS rate compared to 2009 (93.0% versus 87.4%, respectively). For stage II disease, the 5-year PFS rate was similar in the 2023 and the 2009 FIGO staging systems (70.2% versus 71.2%, respectively). The two new molecularly defined 2023 FIGO substages IAmPOLEmut and IICmp53abn displayed distinct, particularly favourable and adverse oncologic outcomes within early stage disease, respectively. A remarkably lower 5-year PFS rate for stage III patients was revealed in the 2023 FIGO staging system compared to 2009 (44.4% versus 54.1%, respectively). All applied statistical tests confirmed a more accurate prediction of PFS and OS by the 2023 FIGO staging system compared to 2009. ConclusionThe new 2023 FIGO stating system led to a substantial stage shift in about one quarter of patients leading to a higher prognostic precision. In early stage disease, the new substages added further prognostic granularity and identified treatment relevant subgroups.

On the road to self-sustainability: reintroduced migratory European northern bald ibises Geronticus eremita still need management interventions for population viability

AbstractThe northern bald ibis Geronticus eremita disappeared from Europe in the Middle Ages. Since 2003 a migratory population has been reintroduced in Central Europe. We conducted demographic analyses of the survival and reproduction of 384 northern bald ibises over a period of 12 years (2008–2019). These data also formed the basis for a population viability analysis simulating the possible future development of the northern bald ibis population under different scenarios. We analysed life stage-specific survival rates, rearing protocols and colonies, and the influence of stochastic catastrophic events and reinforcement translocations on population growth. Life stage-specific survival probabilities were 0.64–0.78. Forty-five per cent of the mature females reproduced, with a mean fecundity of 2.15 fledglings per nest. The complementary population viability analysis indicated that the Waldrappteam population is close to self-sustainability, with an estimated population growth rate of 0.95 and a 24% extinction probability within 50 years. Of the 326 future scenarios tested, 94% reached the criteria of extinction probabilities < 5% and population growth rates > 1. Stochastic catastrophic events had only a limited effect. Despite comparatively high survival and fecundity rates the population viability analysis indicated that to achieve self-sustainability the Waldrappteam population needs further translocations to support population growth and the implementation of effective measures against major mortality threats: illegal hunting in Italy and electrocution on unsecured power poles. The findings of this study are to be implemented as part of a second European LIFE project.

Racial and Ethnic Trends and Disparities in NSCLC

IntroductionDetailed evaluations of racial and ethnic trends and disparities in NSCLC outcomes are lacking, and it remains unclear whether recent advances in screening and targeted therapies for NSCLC have benefited all population groups equally. MethodsUsing the Surveillance, Epidemiology, and End Results 18-registry data, we evaluated trends in overall and stage-specific NSCLC incidence (2007–2018) among patients aged 55 to 79 years by sex and race and ethnicity. Overall and stage-specific 2-year cause-specific survival rates were calculated by sex and race and ethnicity. Health Disparities software calculated absolute (difference) and relative (ratio) disparity measures comparing racial and ethnic groups with the highest and lowest rates (range measures) and comparing white patients (reference group) with other groups (pairwise rate measures). Joinpoint software assessed changes in rates and disparities. ResultsBoth men and women experienced substantial declines in NSCLC incidence from 2007 to 2018, largely due to significant declines in the incidence of distant-stage NSCLC over the study period (p < 0.05). During the same time period, the incidence of local-stage NSCLC significantly increased among black and Hispanic women (p < 0.05) and remained stable among all other groups. Overall, 2-year cause-specific survival rates improved across most racial and ethnic groups, especially among those diagnosed in regional and distant stages. For both sexes, absolute disparities in overall and stage-specific incidence of NSCLC significantly decreased over time (p < 0.05), whereas relative disparities remained unchanged. Pairwise comparison revealed persistent disparities in NSCLC burden between black and white men. ConclusionWe found evidence of narrowing racial and ethnic disparities in NSCLC incidence over time; however, important disparities persist. More work is needed to ensure consistent and equitable access to high-quality screening, diagnosis, and treatment to reduce and eliminate cancer disparities.

Demographic and life history traits explain patterns in species vulnerability to extinction.

As ecosystems face disruption of community dynamics and habitat loss, the idea of determining ahead of time which species can become extinct is an important subject in conservation biology. A species’ vulnerability to extinction is dependent upon both intrinsic (life-history strategies, genetics) and extrinsic factors (environment, anthropogenic threats). Studies linking intrinsic traits to extinction risk have shown variable results, and to our knowledge, there has not been a systematic analysis looking at how demographic patterns in stage-specific survival and reproductive rates correlate to extinction risk. We used matrix projection models from the COMPADRE and COMADRE matrix databases and IUCN Red List status as our proxy of extinction risk to investigate if some demographic patterns are more vulnerable to extinction than others. We obtained data on demographic rates, phylogeny, and IUCN status for 159 species of herbaceous plants, trees, mammals, and birds. We calculated 14 demographic metrics related to different aspects of life history and elasticity values and analyzed whether they differ based on IUCN categories using conditional random forest analysis and phylogenetic generalized least square regressions. We mapped all species within the database, both with IUCN assessment and without, and overlaid them with biodiversity hotspots to investigate if there is bias within the assessed species and how many of the non-assessed species could use the demographic information recorded in COMPADRE and COMADRE for future IUCN assessments. We found that herbaceous perennials are more vulnerable when they mature early and have high juvenile survival rates; birds are more vulnerable with high progressive growth and reproduction; mammals are more vulnerable when they have longer generation times. These patterns may be used to assess relative vulnerability across species when lacking abundance or trend data.

Midterm survival of imaging-assisted robotic lung segmentectomy for non-small-cell lung cancer.

OBJECTIVESOur goal was to report our midterm results using imaging-assisted modalities with robotic segmentectomies for non-small-cell lung cancer (NSCLC).METHODSThis was a retrospective study of all robotic segmentectomies, with confirmed NSCLC, performed at our general and thoracic surgery unit in the Rouen University Hospital (France), from January 2012 through December 2019. Benign and metastatic lesions were excluded. Data were extracted from the EPITHOR French nationwide database.RESULTSA total of 121 robotic segmentectomies were performed for 118 patients with a median age of 65 (interquartile range: 60, 69) years. The majority had clinical stage T1aN0M0 (71.9%) or T1bN0M0 (13.2%). The mean (standard deviation) number of resected segments was 1.93 (1.09) with 80.2% imaging-assisted segmentectomies. Oriented (according to tumour location) or systematic lymphadenectomy or sampling was performed for 72.7%, 23.1% and 4.1% of patients. The postoperative course was uneventful for 94 patients (77.7%), whereas 34 complications occurred for 27 patients (22.3%), including 2 patients (1.7%) with Clavien-Dindo ≥III complications. The mean thoracic drainage duration was 4.12 days, and the median hospital stay was 4 days (interquartile range: 3, 5) after the operation. The 2-year survival rate was 93.9% (95% confidence interval: 86.4–97.8%). Excluding stage IV (n = 3) and stage 0 tumours (n = 6), the 2-year survival rate was 95.7% (95% confidence interval: 88.4–98.8%) compared to an expected survival rate of 94.0% according to stage-specific survival rates found in a large external reference cohort.CONCLUSIONSImaging-guided robotic-assisted thoracic surgery segmentectomy seems to be useful and oncological with good midterm results, especially for patients with early-stage NSCLC.

Review and Synthesis of Estimated Vital Rates for Terrestrial Salamanders in the Family Plethodontidae

Population models depend on reliable estimates of vital rates, yet for many taxa, such estimates and how they vary in response to spatial or temporal environmental gradients are lacking. The goal of this review was to determine whether existing estimates of vital rates for temperate, direct-developing plethodontid salamanders (subfamily Plethodontinae) could be used to reasonably project values for populations or species where such estimates are lacking, or whether current estimates are biased in a manner that limits their utility. We synthesized current knowledge of stage-specific survival rates, age- and size-at-maturity at first clutch, and clutch frequency. We tested for expected correlations among published vital rates (e.g., age at maturity and survival) and between vital rates and factors such as body size or latitude. We used matrix projection models to judge whether published estimates were reasonably possible for stable salamander populations. The largest number of published vital rates were for clutch size, clutch frequency (proportion of females with clutches), size at maturity or first clutch, and age at maturity or first clutch, though the latter vital rate is primarily inferred from size distribution and growth rate data. Among these vital rates, we found expected correlations with body size and latitude suggesting these rates were reasonable and somewhat predictable among species or populations. In contrast, there were few estimates of egg hatch rate or juvenile or adult survival. Hatch and survival rate estimates were widely variable; estimates seldom included measures of uncertainty, but when uncertainty measurements were included, they were generally high. Based on projection models, few survival estimates were likely unbiased or realistic for stable populations given other salamander vital rates. Additionally, few studies quantified how vital rates vary with spatial or temporal environmental gradients. We outline the key knowledge gaps that limit basic demographic modeling of these remarkably common, influential, and otherwise well-studied salamanders, and make recommendations for future research efforts.

Comparison of ICC patients with hepatitis B infection to those with no major risk factors for HCC

BackgroundThere has been renewed interest in HBV-associated ICC, because it could share a common carcinogenesis disease process with HCC. We investigated whether there is a difference in clinical outcome between ICC patients with HBV infection and those without any major risk factors for HCC. MethodsA total of 253 curatively resected, surgically diagnosed ICC patients were analyzed and divided into two groups according to the presence or absence of major risk factors for HCC: an HBV group (n = 45) and a non–HCC–risk (NHR) group (n = 208). ResultsLymph node metastasis was more frequently observed in the NHR group (HBV vs. NHR: 8.89% vs. 24.52%, P = 0.027). Patients in the HBV group demonstrated more favorable survival than those in the NHR group. However, this difference was not statistically significant (5-year survival rate, 54.7% vs. 42.3%, P = 0.128). Cumulative recurrence rate in the HBV group was 62.2%, which was not significantly different from 63.0% in the NHR group (P = 1.000). ConclusionThis study found that while ICC patients with HBV infection showed some favorable tumor characteristics, patients' stage-specific survival and recurrence rates were not significantly different compared to those without any major risk factors for HCC.

Demographic dynamics of Peruvian black-faced spider monkeys (&lt;i&gt;Ateles chamek&lt;/i&gt;) reintroduced in the Peruvian Amazon

&#x0D; &#x0D; &#x0D; Reintroductions of animals are important conservation tools for different taxa around the world. A reintroduction program in the Peruvian Amazon is focusing on black-faced spider monkeys (Ateles chamek). We investigated life-history parameters such as stage-specific survival and female fertility rates using a capture-mark-recapture framework and data from the literature. We estimated growth rate and probability of extinction for a reintroduced group using matrix models, as well as testing whether population growth depends more on survival of juvenile females or adult females. Our results suggest the population of the reintroduced group is decreasing. After projecting the group size for the next 25 years using different scenarios, we found that in order for the group to persist, survival rate of the female adult stage needs to exceed 79 %. Given that group growth rate is more sensitive to the survival of adult females, management measures actions that target this demographic are required to guarantee survival of the group. Extrapolations of our results are subject to restrictions imposed by the small sample size and the conditions specific to this reintroduction program. However, this study may provide valuable lessons for reintroduction programs attempting the recovery of wild populations of similar species.&#x0D; &#x0D; &#x0D;

Stage-Specific Survival Rate of Breast Cancer Patients in Northern Thailand in Accordance with Two Different Staging Systems.

Objective:This study was attempted to investigate overall survival by stage at diagnosis in female breast cancer patients in Northern Thailand by using 2 different staging systems; namely, American Joint Committee on Cancer (AJCC) Tumor (T), Nodal (N) and Metastatic (M) staging system and Surveillance Epidemiology and End Results (SEER) summary staging system. Methods:We studies female breast cancer patients whose data were registered in Chiang Mai cancer registries between January 2006 and December 2015. Data were recorded in SEER summary staging system. The TNM AJCC staging was searched in the medical records. Results:A total of 3,873 female breast cancer patients were diagnosed from 2006-2015. All data sets were recorded in SEER summary stage 2000. Early stage was the most prevalent stage at the time of diagnosis (58%), followed by loco-regional advanced stage (32%), and metastatic breast cancer (10%). The 5-year overall survival rate of early, loco-regional advanced, and metastatic stages were 85.3%, 66.4%, and 26.2%, respectively. After examining the medical records, we excluded patients who had no data on T, N, and M in their records. Finally, only 3,251 patients were analyzed for AJCC stage-specific survival. The 5-year overall survival rate in stages I, II, III, and IV were 94.4%, 85.0%, 56.6%, and 28.3%, respectively. Conclusion:Comparing to more stable economic countries, the 5-year overall survival rate for a specific stage of breast cancer in Northern Thailand was slightly lower in early stage and stage I-II in accordance with AJCC, but much lower in loco-regional stage and stage III with respect to AJCC. Nevertheless, it was similar in metastatic stage and stage IV according to AJCC.

Metastatic patterns and prognostic significance of signet ring cell carcinoma of the colon: Retrospective analysis of SEER database.

488 Background: Signet ring cell carcinoma of the colon (SRCC) represents less than 1% of all colon carcinomas. We retrospectively examined the metastatic patterns and prognosis of SRCC in comparison to adenocarcinoma (AC) of the colon. Methods: A total of 763 patients diagnosed with SRCC and 42,875 patients with AC of the colon from 2010 to 2012 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Age, race, gender, primary site, grade, stage, metastatic site and survival data were collected. Results: Out of 43,638 patients, 78.7% were white, 12.5% black and 8.8% other races. Median age of diagnosis was 67.5 years for SRCC as compared to 69.1 years for AC . SRCC was more likely to be grade III or IV (92% vs 21.6%; p &lt; 0.001), to be found in the right colon (63.7% vs 49.4%; p &lt; 0.001) and to present as advanced stage (40.2% vs 29.4% for stage III and 37.1% vs 22.3% for stage IV; p &lt; 0.001). SRCC was more likely to present with metastases to the brain (11.0% vs 1.3%; p &lt; 0.001) and bone (6.4% vs 4.1%; p &lt; 0.001), while AC subjects were more likely to present with metastases to the liver (77.0% vs 22.1%; p &lt; 0.001) and lung (21.2% vs 5.8%; p &lt; 0.001). The 5 year overall survival rate (5-YSR) was 28.2% (CI, 24.5% to 32.4%) for SRCC compared to 50.8% (CI, 50.1% to 51.6%) for AC (Hazard ratio for death, 1.38; CI, 1.26 to 1.52; P &lt; 0.001). The differences in stage specific 5-year survival rates for SRCC and AC were not statistically significant for stage I and stage II. However, SRCC had a lower 5-YSR for stage III (34.5% vs 55.4%) and stage IV (3.3% vs 10.8%). Conclusions: SRCC of the colon has worse survival rates for advanced stages when compared to AC. SRCC presents at earlier age, with advanced tumor grade and stage at diagnosis. The metastatic behavior of SRCC is different than AC with a higher incidence of brain and bone metastases at diagnosis.

Response to Short-Term Cold Storage for Eggs of Agasicles hygrophila (Coleoptera: Chrysomelidae), a Biological Control Agent of Alligator Weed Alternanthera philoxeroides (Caryophyllales: Amaranthaceae).

The alligator weed flea beetle, Agasicles hygrophila Selman & Vogt (Coleoptera: Chrysomelidae) has been used very successfully for the biological control of the widely-distributed invasive weed Alternanthera philoxeroides (Mart.) Griseb (Caryophyllales: Amaranthaceae). In order to extend the 'shelf life' of natural enemies released in biological control programs, cold storage has proven to be a valuable commercial procedure. To determine a suitable low temperature for storage of A. hygrophila, we conducted short-term cold storage treatments of eggs (4°C for 0.5, 1, 2, 5 d, and 7.5, 10, 15°C for 5 d and a control of 25°C; all eggs were returned to 25°C after the treatments). We evaluated the effects of these treatments on the subsequent fitness of the populations based on a demographic analysis using group-reared age-stage two-sex life tables. For 5 d storage, temperatures below 10°C had lethal effects, which were also observed at 4°C for 2 d storage. Storage at 4°C for 0.5 d did not affect the fitness of A. hygrophila, but it did not prolong the developmental time. Storage at 10°C for 5 d significantly decreased rates of population increase compared with 25°C. A. hygrophila stored at 15°C for 5 d had similar age-(stage) specific survival rates, rates of population increase, increased longevity and reproductive capability to the controls at 25°C. It is concluded that there were no significant fitness costs after 5 d storage at 15°C, which is therefore potentially a suitable storage temperature for A. hygrophila eggs.

The interacting effects of forestry and climate change on the demography of a group-living bird population.

Anthropogenic degradation of natural habitats is a global driver of wildlife population declines. Local population responses to such environmental perturbations are generally well understood, but in socially structured populations, interactions between environmental and social factors may influence population responses. Thus, understanding how habitat degradation affects the dynamics of these populations requires simultaneous consideration of social and environmental mechanisms underlying demographic responses. Here we investigated the effect of habitat degradation through commercial forestry on spatiotemporal dynamics of a group-living bird, the Siberian jay, Perisoreus infaustus, in boreal forests of northern Sweden. We assessed the interacting effects of forestry, climate and population density on stage-specific, seasonal life-history rates and population dynamics, using long-term, individual-based demographic data from 70 territories in natural and managed forests. Stage-specific survival and reproductive rates, and consequently population growth, were lower in managed forests than in natural forests. Population growth was most sensitive to breeder survival and was more sensitive to early dispersing juveniles than those delaying dispersal. Forestry decreased population growth in managed forests by reducing reproductive success and breeder survival. Increased snow depth improved winter survival, and warmer spring temperatures enhanced reproductive success, particularly in natural forests. Population growth was stable in natural forests but it was declining in managed forests, and this difference accelerated under forecasted climate scenarios. Thus, climatic change could exacerbate the rate of forestry-induced population decline through reduced snow cover in our study species, and in other species with similar life-history characteristics and habitat requirements.

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

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.

Population Dynamics and Survival Rates of American Oystercatchers (Haematopus palliatus) in Virginia, USA

Information on demographic parameters needed to inform conservation strategies for American Oystercatchers (Haematopus palliatus) is lacking. The population dynamics of American Oystercatchers in Virginia, USA, were examined using a multi-state analysis framework that modeled movement of American Oystercatchers into and out of the State. Change in breeding status, age-specific survival rates, and age at first breeding were investigated for three geographically distinct study sites. Non-breeding American Oystercatchers originating from Virginia readily moved in and out of the State among years. The immigration rate for birds breeding on barrier islands was 6% Emigration rates were 6% for the barrier island breeding population and 17% for the seaside lagoon population. Stage-specific annual survival rates were 0.66, 0.95 and 0.91 for juvenile, sub-adult and adult stages, respectively. Age at first breeding peaked in the fourth year for both the barrier island and seaside lagoon breeding populations. Movement and recruitment rates suggested that the barrier islands may provide the highest quality breeding habitat among the three study sites. This study showed that Virginia's American Oystercatcher population is linked with other Atlantic Coast populations, and these links should be considered when evaluating local population trends and management targets.

Colorectal Cancer Survival Disparities among Puerto Rican Hispanics: A Comparison to Racial/Ethnic Groups in the United States.

Ethnic/racial disparities in colorectal cancer (CRC) survival have been well documented. However, there is limited information regarding CRC survival among Hispanic subgroups. This study reports the 5-year relative survival of Puerto Rican Hispanic (PRH) CRC patients and the relative risk of death compared to other racial/ethnic groups in the US. CRC incidence data from subjects ≥50 years was obtained from the Puerto Rico Central Cancer Registry and the Surveillance, Epidemiology and End Results (SEER) database from January 1, 2001 to December 31, 2003. Relative survival rates were calculated using the life tables from the population of PR and SEER. A Poisson regression model was used to assess relative risk of death by stage, sex, and age. A total of 76,444 subjects with incident CRC were analyzed (non-Hispanic White (NHW) n=59,686; non-Hispanic black (NHB) n=7,700; US Hispanics (USH) n=5,699; PRH n=3,359). Overall and stage-specific five-year survival rates differed by race/ethnicity. When comparing PRH to the other racial/ethnic groups, PRH had the lowest survival rates in regional cancers and were the only racial/ethnic group where a marked 5-year survival advantage was observed among females (66.0%) compared to males (60.3%). A comparable and significantly higher relative risk of death of CRC was observed for PRH and NHB compared to NHW. Our findings establish baseline CRC survival data for PRH living in Puerto Rico. The gender and racial/ethnic disparities observed in PRH compared to US mainland racial/ethnic groups warrant further investigation of the risk factors affecting this Hispanic subgroup.