Improved methods for estimating abundance and related demographic parameters from mark-resight data.

Over the past decade, there has been much methodological development for the estimation of abundance and related demographic parameters using mark-resight data. Often viewed as a less-invasive and less-expensive alternative to conventional mark recapture, mark-resight methods jointly model marked individual encounters and counts of unmarked individuals, and recent extensions accommodate common challenges associated with imperfect detection. When these challenges include both individual detection heterogeneity and an unknown marked sample size, we demonstrate several deficiencies associated with the most widely used mark-resight models currently implemented in the popular capture-recapture freeware Program MARK. We propose a composite likelihood solution based on a zero-inflated Poisson log-normal model and find the performance of this new estimator to be superior in terms of bias and confidence interval coverage. Under Pollock's robust design, we also extend the models to accommodate individual-level random effects across sampling occasions as a potentially more realistic alternative to models that assume independence. As a motivating example, we revisit a previous analysis of mark-resight data for the New Zealand Robin (Petroica australis) and compare inferences from the proposed estimators. For the all-too-common situation where encounter rates are low, individual detection heterogeneity is non-negligible, and the number of marked individuals is unknown, we recommend practitioners use the zero-inflated Poisson log-normal mark-resight estimator as now implemented in Program MARK.

Molecular characterisation of beak and feather disease virus (BFDV) in New Zealand and its implications for managing an infectious disease.

Beak and feather disease virus (BFDV) infections are often fatal to both captive and wild parrot populations. Its recent discovery in a wild population of native red-fronted parakeets has raised concerns for the conservation of native parrots, all of which are threatened or endangered. The question of a recent introduction versus a native genotype of the virus poses different conservation-management challenges, and thus, a clear understanding of the molecular phylogeny of BDFV is a crucial step towards integrated management planning. This study represents the first comprehensive attempt to screen New Zealand's endangered and threatened psittacines systematically for BFDV. We sampled and screened kakapos (Strigops habroptilus), kakas (Nestor meridionalis), keas (N. notabilis), Chatham parakeets (Cyanoramphus forbesi), Malherbe's parakeets (Cyanoramphus malherbi), yellow-crowned parakeets (C. auriceps) and red-fronted parakeets (Cyanoramphus novaezelandiae), as well as eastern rosellas (Platycercus eximius), an introduced species that is now common throughout the North Island, for BFDV. Out of all species and populations sampled (786 individuals), we found 16 BFDV-positive red-fronted parakeets from Little Barrier Island/Hauturu, seven eastern rosellas from the Auckland region, and eight yellow-crowned parakeets from the Eglinton Valley in the South Island. The full genomes of the viral isolates from the red-fronted parakeets share 95-97 % sequence identity to those from the invasive eastern rosellas and 92.7-93.4 % to those isolates from the South Island yellow-crowned parakeets. The yellow-crowned parakeet BFDV isolates share 92-94 % sequence identity with those from eastern rosellas. The low level of diversity among all BFDV isolates from red-fronted parakeets could suggest a more recent infection among these birds compared to the yellow-crowned parakeets, whereas the diversity in the eastern rosellas indicates a much more established infection. Pro-active screening and monitoring of BFDV infection rates in aviaries as well as in wild populations are necessary to limit the risk of transmission among threatened and endangered parrot populations in New Zealand.

Efficacy of dietary behavior modification for preserving cardiovascular health and longevity.

Cardiovascular disease (CVD) and its predisposing risk factors are major lifestyle and behavioral determinants of longevity. Dietary lifestyle choices such as a heart healthy diet, regular exercise, a lean weight, moderate alcohol consumption, and smoking cessation have been shown to substantially reduce CVD and increase longevity. Recent research has shown that men and women who adhere to this lifestyle can substantially reduce their risk of coronary heart disease (CHD). The preventive benefits of maintaining a healthy lifestyle exceed those reported for using medication and procedures. Among the modifiable preventive measures, diet is of paramount importance, and recent data suggest some misconceptions and uncertainties that require reconsideration. These include commonly accepted recommendations about polyunsaturated fat intake, processed meat consumption, fish choices and preparation, transfatty acids, low carbohydrate diets, egg consumption, coffee, added sugar, soft drink beverages, glycemic load, chocolate, orange juice, nut consumption, vitamin D supplements, food portion size, and alcohol.

Cross-sectional relations of digital vascular function to cardiovascular risk factors in the Framingham Heart Study.

BACKGROUND: Digital pulse amplitude augmentation in response to hyperemia is a novel measure of peripheral vasodilator function that depends partially on endothelium-derived nitric oxide. Baseline digital pulse amplitude reflects local peripheral arterial tone. The relation of digital pulse amplitude and digital hyperemic response to cardiovascular risk factors in the community is unknown. METHODS AND RESULTS: Using a fingertip peripheral arterial tonometry (PAT) device, we measured digital pulse amplitude in Framingham Third Generation Cohort participants (n=1957; mean age, 40+/-9 years; 49% women) at baseline and in 30-second intervals for 4 minutes during reactive hyperemia induced by 5-minute forearm cuff occlusion. To evaluate the vascular response in relation to baseline, adjusting for systemic effects and skewed data, we expressed the hyperemic response (called the PAT ratio) as the natural logarithm of the ratio of postdeflation to baseline pulse amplitude in the hyperemic finger divided by the same ratio in the contralateral finger that served as control. The relation of the PAT ratio to cardiovascular risk factors was strongest in the 90- to 120-second postdeflation interval (overall model R(2)=0.159). In stepwise multivariable linear regression models, male sex, body mass index, ratio of total to high-density lipoprotein cholesterol, diabetes mellitus, smoking, and lipid-lowering treatment were inversely related to PAT ratio, whereas increasing age was positively related to PAT ratio (all P<0.01). CONCLUSIONS: Reactive hyperemia produced a time-dependent increase in fingertip pulse amplitude. Digital vasodilator function is related to multiple traditional and metabolic cardiovascular risk factors. Our findings support further investigations to define the clinical utility and predictive value of digital pulse amplitude.