Large‐scale predator control increases population viability of a rare New Zealand riverine duck

The introduction of mammalian predators to oceanic islands has led to dramatic declines in the abundance of many native species. Conservation management of these species often relies on low‐cost predator control techniques that can be implemented over large scales. Assessing the effectiveness of such management techniques is difficult, but using population viability analyses (PVA), which identify the population growth rate (λ) and extinction risk of threatened species, may offer a solution. PVA provide the opportunity to compare the relative effectiveness of various management options and can identify knowledge gaps to prioritize research efforts. We used PVA to assess the population viability of whio (Hymenolaimus malacorhynchos), a rare riverine duck endemic to New Zealand. Current populations are threatened by introduced mammalian predators and are rapidly declining in both distribution and abundance. Whio conservation management is dominated by large‐scale, low‐intensity predator control, targeting introduced stoats (Mustela erminea). There is evidence that such control increases whio productivity but it is unknown if this increase is sufficient for long‐term population persistence. We undertook a stochastic PVA to assess the viability of whio populations under different management scenarios using data obtained from a 6‐year study of whio demographic responses to predator control. Populations with no predator control and low productivity will rapidly decline to extinction. Increasing productivity through predator control increased population viability but populations still showed a declining trajectory. A perturbation analysis showed that the growth rate of whio populations was largely driven by adult survival. Therefore, future research should target obtaining more robust estimates of adult survival, particularly how it is affected by predator control. Overall, our analysis indicated that large‐scale predator control increases the short‐term viability of whio populations but is insufficient for long‐term population persistence.     

Habitat management as a generalized tool to boost European rabbit Oryctolagus cuniculus populations in the Iberian Peninsula: a cost‐effectiveness analysis

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Using genetic techniques to quantify reinvasion,survival and in situ breeding rates during control operations

Determining the origin of individuals caught during a control/eradication programme enables conservation managers to assess the reinvasion rates of their target species and evaluate the level of success of their control methods. We examine how genetic techniques can focus management by distinguishing between hypotheses of ‘reinvasion’ and ‘survivor’, and defining kin groups for invasive stoats (Mustela erminea) on Secretary Island, New Zealand. 205 stoats caught on the island were genotyped at 16 microsatellite loci, along with 40 stoats from the opposing mainland coast, and the age and sex were determined for each individual. Using these data, we compare and combine a variety of genetic techniques including genetic clustering, population assignment and kinship‐based techniques to assess the origin of each stoat. The population history and individual movement could be described in fine detail, with results indicating that both in‐situ survival and breeding, and reinvasion are occurring. Immigration to the island was found to be generally low, apart from in 1 year where around 8 stoats emigrated from the mainland. This increased immigration was probably linked to a stoat population spike on the mainland in that year, caused by a masting event of southern beech forest (Nothofagus sp.) and the subsequent rodent irruption. Our study provides an example of some of the ways genetic analyses can feed directly into informing management practices for invasive species.     

Personality assessment in the gorilla and its utility as a management tool

Goals of the Gorilla Species Survival Plan (SSP) include increased captive propagation, maintenance of genetic diversity, and consideration of the psychological well-being of the population. The SSP Propagation Group has attempted to accomplish these goals through recommendations based on assessment of genetic, behavioral, and demographic variables. A need is recognized for the development of a methodology to assess behavioral variables that contribute to the success of animal moves. Personality profiles have been used in the past to aid animal management decisions in laboratory settings. This paper describes personality assessment techniques, reviews historical perspectives on primate personality assessment, and reports on a study to assess gorilla personality. The Gorilla Behavior Index (GBI), a subjective assessment instrument consisting of behaviorally based adjectives, was completed for 298 of 303 captive gorillas over 1 year of age. The results were subjected to common factor analysis, resulting in the identification of four main factors: extroverted, dominant, fearful, and understanding. Frequency distributions were calculated illustrating the ranges of each factor. Potential management uses for the GBI scores are discussed. © 1994 Wiley-Liss, Inc.     

Extinction risk assessment for the species survival plan (SSP®) population of the Bali mynah (Leucopsar rothschildi)

The Bali mynah Species Survival Plan (SSP^®), an Association of Zoos and Aquariums program, strives to maintain the genetic and demographic health of its population, avoid unplanned changes in size, and minimize the risk of population extinction. The SSP population meets current demographic and genetic objectives with a population size of 209 birds at 61 institutions and 96% genetic diversity (GD) retained from the source population. However, participating institutions have expressed concerns regarding space allocation, target population size (TPS), breeding restrictions, inbreeding depression, and harvest in relation to future population availability and viability. Based on these factors, we assess five questions with a quantitative risk assessment, specifically a population viability analysis (PVA) using ZooRisk software. Using an individual-based stochastic model, we project potential population changes under different conditions (e.g. changes in TPS and genetic management) to identify the most effective management actions. Our projections indicate that under current management conditions, population decline and extinction are unlikely and that although GD will decline over 100 years the projected loss does not exceed levels acceptable to population managers (less than 90% GD retained). Model simulations indicate that the combination of two genetic management strategies (i.e. priority breeding based on mean kinship and inbreeding avoidance) benefits the retention of GD and reduces the accumulation of inbreeding. The current TPS (250) is greater than necessary to minimize the risk of extinction for the SSP population but any reduction in TPS must be accompanied by continued application of genetic management. If carefully planned, birds can be harvested for transfer to Bali for a reintroduction program without jeopardizing the SSP population. Zoo Biol 28:230–252, 2009. © 2009 Wiley-Liss, Inc.     

Hemorrhage During Long-Term Anticoagulant Drug Therapy—Part IV: Selection and Management of Patients

Most serious hemorrhages that occur during long-term anticoagulant drug therapy are due either to poor patient selection or to poor management of the patient, or both.In each patient being considered for treatment, the risk of bleeding must be evaluated and classified as high, moderate or low.The clinician must especially assess the risk of intracranial hemorrhage in hypertensive patients, and must screen all patients for potential sources of gastrointestinal bleeding. There is ample time for such investigations, since initiating long-term anticoagulant therapy is not an emergency procedure.The desired level of prothrombin activity must be adjusted to the risks determined for each individual patient. There is no single “therapeutic range” applicable to all patients with their varying hemorrhagenic risks.Proper management includes sufficient laboratory testing to maintain the desired prothrombin level, and continued vigilance to detect signs of early bleeding.Preventable hemorrhage cannot be cited as evidence against the value of anticoagulant drug therapy.     

Two criteria for evaluating risk prediction models

Summary We propose and study two criteria to assess the usefulness of models that predict risk of disease incidence for screening and prevention, or the usefulness of prognostic models for management following disease diagnosis. The first criterion, the proportion of cases followed PCF (q) , is the proportion of individuals who will develop disease who are included in the proportion q of individuals in the population at highest risk. The second criterion is the proportion needed to follow‐up, PNF (p) , namely the proportion of the general population at highest risk that one needs to follow in order that a proportion p of those destined to become cases will be followed. PCF (q) assesses the effectiveness of a program that follows 100q % of the population at highest risk. PNF (p) assess the feasibility of covering 100p % of cases by indicating how much of the population at highest risk must be followed. We show the relationship of those two criteria to the Lorenz curve and its inverse, and present distribution theory for estimates of PCF and PNF. We develop new methods, based on influence functions, for inference for a single risk model, and also for comparing the PCFs and PNFs of two risk models, both of which were evaluated in the same validation data.     

Integral projection models perform better for small demographic data sets than matrix population models: a case study of two perennial herbs

1. Matrix population models are widely used to describe population dynamics, conduct population viability analyses and derive management recommendations for plant populations. For endangered or invasive species, management decisions are often based on small demographic data sets. Hence, there is a need for population models which accurately assess population performance from such small data sets.
2. We used demographic data on two perennial herbs with different life histories to compare the accuracy and precision of the traditional matrix population model and the recently developed integral projection model (IPM) in relation to the amount of data.
3. For large data sets both matrix models and IPMs produced identical estimates of population growth rate (λ). However, for small data sets containing fewer than 300 individuals, IPMs often produced smaller bias and variance for λ than matrix models despite different matrix structures and sampling techniques used to construct the matrix population models.
4. Synthesis and applications . Our results suggest that the smaller bias and variance of λ estimates make IPMs preferable to matrix population models for small demographic data sets with a few hundred individuals. These results are likely to be applicable to a wide range of herbaceous, perennial plant species where demographic fate can be modelled as a function of a continuous state variable such as size. We recommend the use of IPMs to assess population performance and management strategies particularly for endangered or invasive perennial herbs where little demographic data are available.     

Biostatistics and epidemiology: measuring the risk attributable to an environmental or genetic factor

Disease frequency is measured through estimating incidence rates or disease risk. Several measures are used for assessing exposure-disease association, with adjusted estimates based on standardization, stratification, or more flexible regression techniques. Several measures are available to assess an exposure impact in terms of disease occurrence at the population level, including the commonly used attributable risk (AR). Adjusted AR estimation relies on stratification or regression techniques. Sequential and partial ARs have been proposed to handle the situation of multiple exposures and circumvent the associated non-additivity problem. Despite remaining issues in properly interpreting AR, AR remains a useful guide to assess prevention strategies.     

Factors contributing to discrepancies in population monitoring studies

A review of the scientific literature on population monitoring studies (on non-accidentally exposed populations) frequently show that many of these studies using similarly exposed populations and the same laboratory techniques do not produce consistent results. To illustrate the problem, a brief review of studies using well validated techniques (chromosome aberrations and hprt gene mutation) to elucidate genotoxic effects of cigarette smoking is presented. Although many factors can contribute to the generation of discrepant results, two obvious factors are small sample sizes and inadequate experimental data. In addition, a new factor on genetic susceptibility should be considered in population studies whenever appropriate. The new factor is based on recent data showing the influence of polymorphic metabolizing genes on response to environmental mutagens towards biological effects and disease outcome. The common ones include the cytochrome P450 and the glutathione S-transferase genes. The inclusion of susceptibility factors in population monitoring may revolutionize the approach for health risk assessment and for environmental regulations.     

Long-Term Evaluation of Cougar Density and Application of Risk Analysis for Harvest Management

Estimates of cougar (Puma concolor) density are among the least available of any big game species in North America because of monetary and logistical challenges. Thus, wildlife managers identify cougar density estimates as a high priority need for population estimation, developing harvest guidelines, and evaluating management objectives. Cougar densities range from <1 to almost 7 cougars/100 km²; however, the magnitude of spatial and temporal variation associated with these estimates is difficult to assess because this range of densities could potentially be reported for any given population using different demographic, temporal, durational, and analytical approaches. We used long-term global positioning system (GPS) data from collared cougars across 5 diverse study areas in Washington, USA, as the basis for calculating multiple annual independent-aged (≥18 months) cougar densities, using consistent methods, and conducted a meta-analysis to assist with statewide harvest guidelines. To generate specific harvest guidelines for unobserved populations at the management unit scale, we employed a Bayesian decision-theoretic approach that minimizes statistical risk of failing to achieve a defined harvest rate. For the 16-year field effort, we calculated 24 annual densities for independent-aged cougars. Average annual densities ranged from 1.55 ± 0.44 (SD) cougars/100 km² (n = 5 years) to 2.79 ± 0.35 cougars/100 km² (n = 5 years) among the 5 study areas. Explicit delineation of the cougar population demonstrated that contribution to density can vary considerably by sex and age class. Application of a 12–16% harvest rate within the risk analysis framework yielded a potential annual harvest of 249 cougars over 91,000 km² of cougar habitat in Washington. Given the importance of density for establishing harvest guidelines, and the degree of uncertainty in projecting derived densities to future years and unstudied management units, our approach may lessen the ambiguity of extrapolations and increase the longevity of research results. Our risk analysis can be used for a diverse array of species and management objectives and be incorporated into an adaptive management framework for minimizing management risk. Our recommendations can improve standardization in reporting and interpretation of cougar density comparisons and bring clarity to the sources of variability observed in cougar populations. © 2021 The Wildlife Society.     

Projected population persistence of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) using a stage-structured life-history model and population viability analysis

The population of eastern hellbenders (Cryptobranchus alleganiensis alleganiensis) in the Blue River, Indiana has undergone a dramatic decline over the last decade. Recruitment in these declining populations has been negligible, and populations are now composed almost entirely of older age classes (upwards of 20 years old). Given this dramatic decline, it is imperative to assess the impacts of these demographic patterns on population growth and long-term stability. Therefore, we developed a stage-structured, life-history model to examine the effects of varying levels of egg, juvenile, and adult survivorship on abundance, recruitment, and long-term population projections. We performed a sensitivity analysis of the model and determine which life-history parameters have the greatest potential to increase/stabilise hellbender population growth. Finally, we conducted a population viability analysis to determine the probability of extinction associated with varying management strategies. For eastern hellbender populations in Indiana, adults (especially females) are the most important component of long-term population viability. Sensitivity and elasticity analyses of the Lefkovitch matrix revealed that survival of adult and egg/larvae life-history stages are the most important for focused management efforts. Indeed, adults had the highest elasticity and reproductive value in the matrix model. Increasing survival by as little as 20% corresponded to the turning point at which the population ceased to decline and increased abundance (28% survival of egg/larvae). The importance of the transition from subadult to adult (transitional matrix element) was identified as an additional factor in maintaining abundance based on the relatively long period spent in this life-history stage (seven years for females). A population viability analysis was conducted to assess the likelihood and projected time frame of extinction for this population under no management (～25 years to complete extirpation; probability of extinction = 1) and if management efforts such as captive rearing and headstarting are undertaken (probability of extinction <0.2 at 25–30% survival of egg/larvae). Adult females had the greatest effect in reducing growth rate and population abundance when removed in exploitation simulations (91.3% versus 51.8% reduction in population growth rate), indicating translocation efforts should be designed to maintain females in the breeding pool. These models indicated that conservation management strategies aimed at ensuring the presence of adult females while concomitantly ameliorating survival at early life stages (population augmentation, translocations, introduction of artificial nest structures) are needed to stabilise the Indiana population of eastern hellbenders. This stage-structured model is the first to model eastern hellbenders and has broad implications for use across the geographic range where populations of eastern hellbenders are monitored and vital rates can be estimated.     

Do doctors accurately assess coronary risk in their patients? Preliminary results of the coronary health assessment study.

OBJECTIVE--To evaluate the ability of doctors in primary care to assess risk patients'' risk of coronary heart disease. DESIGN--Questionnaire survey. SETTING--Continuing medical education meetings, Ontario and Quebec, Canada. SUBJECTS--Community based doctors who agreed to enroll in the coronary health assessment study. MAIN OUTCOME MEASURE--Ratings of coronary risk factors and estimates by doctors of relative and absolute coronary risk of two hypothetical patients and the "average" 40 year old Canadian man and 70 year old Canadian woman. RESULTS--253 doctors answered the questionnaire. For 30 year olds the doctors rated cigarette smoking as the most important risk factor and raised serum triglyceride concentrations as the least important; for 70 year old patients they rated diabetes as the most important risk factor and raised serum triglyceride concentrations as the least important. They rated each individual risk factor as significantly less important for 70 year olds than for 30 year olds (all risk factors, P < 0.001). They showed a strong understanding of the relative importance of specific risk factors, and most were confident in their ability to estimate coronary risk. While doctors accurately estimated the relative risk of a specific patient (compared with the average adult) they systematically overestimated the absolute baseline risk of developing coronary disease and the risk reductions associated with specific interventions. CONCLUSIONS--Despite guidelines on targeting patients at high risk of coronary disease accurate assessment of coronary risk remains difficult for many doctors. Additional strategies must be developed to help doctors to assess better their patients'' coronary risk.     

Duration of Adulthood Overweight,Obesity, and Cancer Risk in the Women’s Health Initiative: A Longitudinal Study from the United States

BackgroundHigh body mass index (BMI) has become the leading risk factor of disease burden in high-income countries. While recent studies have suggested that the risk of cancer related to obesity is mediated by time, insights into the dose-response relationship and the cumulative impact of overweight and obesity during the life course on cancer risk remain scarce. To our knowledge, this study is the first to assess the impact of adulthood overweight and obesity duration on the risk of cancer in a large cohort of postmenopausal women.ConclusionsIn summary, this study showed that a longer duration of overweight and obesity is associated with an increased risk of developing several forms of cancer. Furthermore, the degree of overweight experienced during adulthood seemed to play an important role in the risk of developing cancer, especially for endometrial cancer. Although the observational nature of our study precludes inferring causality or making clinical recommendations, our findings suggest that reducing overweight duration in adulthood could reduce cancer risk and that obesity prevention is important from early onset. If this is true, health care teams should recognize the potential of obesity management in cancer prevention and that excess body weight in women is important to manage regardless of the age of the patient.     

Attitudes toward genetic testing for cancer risk after genetic counseling and decision support: a qualitative comparison between hereditary cancer types

This study aimed to qualitatively assess individuals' attitudes toward genetic testing for cancer risk after genetic counseling and decision support. As part of a larger study, 78 women considering genetic testing for hereditary breast/ovarian cancer (HBOC) risk and 22 individuals considering genetic testing for hereditary nonpolyposis colorectal cancer (HNPCC) completed an open-ended table of their perceived pros and cons of genetic testing. The most frequently reported pros were "to help manage my risk of developing cancer," "to help my family," and "to know my cancer risk." With regards to risk management, the HBOC group perceived genetic testing as most helpful in informing their general risk management practices, while the HN-PCC group focused on the potential to clarify their need for bowel cancer screening, suggesting that patients' perceptions of the benefits of genetic testing may differ across cancer syndromes. Individuals in both groups expressed concern about the potential psychological impact of genetic testing. We also found that some affected individuals may not fully comprehend the meaning of their potential test results. Eliciting patients' perceived pros and cons during genetic counseling is likely to be a valuable tool for improving patient care. This data also provides an improved evidence base for the development of patient education tools.     

Common Infections in Patients Prescribed Systemic Glucocorticoids in Primary Care: A Population-Based Cohort Study

BackgroundLittle is known about the relative risk of common bacterial, viral, fungal, and parasitic infections in the general population of individuals exposed to systemic glucocorticoids, or about the impact of glucocorticoid exposure duration and predisposing factors on this risk.ConclusionsThe relative risk of LRTI and local candidiasis is very high during the first weeks of glucocorticoid exposure. Further studies are needed to assess whether low albumin level is a risk factor for infection by itself (e.g., by being associated with a higher free glucocorticoid fraction) or whether it reflects other underlying causes of general debilitation.     

RADIATION: MEDICAL DIAGNOSTIC USES

Use of radiologic procedures in diagnosis now contributes a significant dose of ionizing radiation to our population. Whether this presents a real risk to the health of the present and future population cannot be determined with certainty from evidence available at this time. Hence, it appears proper to keep the dose to every patient as low as practical consistent with good medical practice. The average dose can be significantly reduced by having more physicians apply the known techniques for minimizing the exposure to the patient.The medical profession has a direct professional concern for the actual or potential risk of damage resulting from the radiation that patients are exposed to during diagnostic x-ray procedures, since these procedures constitute the largest single man-made source of genetically significant radiation our population is now exposed to.It is important to distinguish two distinctly different types of radiation effects—somatic effect, in which the damage affects the health of the person irradiated, and genetic effect that is capable of producing constitutional defects in future progeny over many generations.     

手术后恶心呕吐的机制及其防治

在过去的几十年里,随着各种手术技术的不断提高和完善,已使外科手术的死亡率大幅降低,这使医生的注意力逐渐转向手术后的并发症和患者的满意程度上,如手术后恶心呕吐。恶心呕吐是术后严重的并发症之一,尽管术后恶心呕吐(Postoperativenausea and vomiting,PONV)是非致命性的并发症,但是PONV可导致严重的后果,并且增加了医疗费用,极大的影响了患者的满意程度。PONV高发率一直困扰着临床医生和患者。所以,探讨其发生及其风险因素是十分必要的。但是,术后恶心呕吐的病理生理学机制还不是十分清楚,本文总结了目前关于术后恶心呕吐发生机制的一些观点以及术后恶心呕吐的风险因素。虽然以往大量的文献报道了如何预防和治疗术后恶心呕吐,但迄今为止,5-HT3受体拮抗剂仍然是临床上使用的最主要的止吐药。目前,一些新药物,如NK-1受体拮抗剂、更加长效的5-HT3受体拮抗剂以及对于PONV高风险的病人实行的多模式管理和新技术的应用,正变得越来越突出。本文综述了现今手术后恶心呕吐的防治方法的最新进展。     

Effect of non-attenders on the potential of a primary care programme to reduce cardiovascular risk in the population. Family Heart Study Group.

OBJECTIVES--To determine the feasibility of enrolling non-attenders of a population based cardiovascular risk reduction programme (the British family heart study) into a further, similar programme and to assess the effect of non-attendance on the effectiveness of the programme. DESIGN--Follow up of non-attenders by practice nurses, including home visits if necessary, to administer questionnaires and obtain physiological measurements. SETTING--Eight general practices across England, Scotland, and Wales. SUBJECTS--Non-attenders in a cardiovascular risk factor screening and intervention programme compared with attenders. MAIN OUTCOME MEASURES--Number of non-attenders enrolled; sociodemographic characteristics; personal and family history of coronary heart disease; cardiovascular risk factors; and total coronary risk score. RESULTS--Data were collected from 106 (17%) of the 608 non-attending families (99 men and 42 women). Of the 543 non-attending families from five practices that attempted complete follow up, 256 had moved away or died. Only 76 were eventually enrolled into the study. The prevalence of coronary heart disease and a family history of coronary heart disease were similar among non-attenders and attenders as were the individual coronary risk factors studied except smoking. Women non-attenders were more likely to be current cigarette smokers than attenders (15/42 v 202/948, P = 0.02). CONCLUSIONS--The intensive follow up of non-attenders resulted in real intervention opportunities in only a small number. Since the effect of any intervention in a population is reduced by non-attendance audit of preventive medical programmes aimed at the population should allow for the effect of non-attenders on the overall results.     

New models for evaluation of radiation-induced lifetime cancer risk and its uncertainty employed in the UNSCEAR 2006 report

Generalized relative and absolute risk models are fitted to the latest Japanese atomic bomb survivor solid cancer and leukemia mortality data (through 2000), with the latest (DS02) dosimetry, by classical (regression calibration) and Bayesian techniques, taking account of errors in dose estimates and other uncertainties. Linear-quadratic and linear-quadratic-exponential models are fitted and used to assess risks for contemporary populations of China, Japan, Puerto Rico, the U.S. and the UK. Many of these models are the same as or very similar to models used in the UNSCEAR 2006 report. For a test dose of 0.1 Sv, the solid cancer mortality for a UK population using the generalized linear-quadratic relative risk model is estimated as 5.4% Sv(-1) [90% Bayesian credible interval (BCI) 3.1, 8.0]. At 0.1 Sv, leukemia mortality for a UK population using the generalized linear-quadratic relative risk model is estimated as 0.50% Sv(-1) (90% BCI 0.11, 0.97). Risk estimates varied little between populations; at 0.1 Sv the central estimates ranged from 3.7 to 5.4% Sv(-1) for solid cancers and from 0.4 to 0.6% Sv(-1) for leukemia. Analyses using regression calibration techniques yield central estimates of risk very similar to those for the Bayesian approach. The central estimates of population risk were similar for the generalized absolute risk model and the relative risk model. Linear-quadratic-exponential models predict lower risks (at least at low test doses) and appear to fit as well, although for other (theoretical) reasons we favor the simpler linear-quadratic models.