Nesting ecology of migratory golden eagles (Aquila chrysaetos) in Denali National Park, AK

Thesis (M.S.) University of Alaska Fairbanks, 1995Between 1988 and 1993 I measured occupancy of nesting territories and reproduction of golden eagles (Aquila chrysaetos) in Denali National Park, Alaska. I collected data occupancy of nesting territories and three reproductive variables (pairs nesting, pairs producing fledglings, and fledgling production) at 74 nesting territories using three aerial surveys each year. During my study, annual fledgling production varied nearly threefold, from 20 fledglings in 1992 to 58 fledglings in 1989. Although rates of nesting territory occupancy did not vary significantly among years (yj = 8.21, d.f. = 5, P = 0.114), I noted significant variation in the proportion of pairs laying eggs (X2 = 33.12, d.f. = 5, P < 0.001) and the proportion of pairs fledging young (X2 = 16.03, d.f. = 5, P = 0.007) among years. Decreases in pairs laying eggs were correlated with decreases in average daily numbers of snowshoe hare (Lepus americanus) and willow ptarmigan (Lagopus lagopus) observed in the study area (rs = 0.83, P = 0.04)

Golden Eagles in Denali National Park and Preserve : productivity and survival in relation to landscape characteristics of nesting territories

Denali National Park and Preserve (Denali) contains one of the highest densities of nesting Golden Eagles (Aquila cluysaetos) in North America. Productivity of this migratory population varies both temporally and spatially. Regardless of prey abundance, more fledglings are consistently produced at some nesting territories than others. In many raptor studies, the areas where the most fledglings are produced are often considered the highest quality nesting territories; however, few studies have examined the relationship between productivity and survival of juvenile Golden Eagles. I studied the effects of landscape characteristics of nesting territories on the productivity and survival of Golden Eagle in Denali. I quantitatively described the landscape characteristics including land cover composition, elevation, and terrain ruggedness, surrounding 36 Golden Eagle nesting sites and compared the landscape characteristics between 18 low and 18 high production nesting territories. I also instrumented 48 fledgling Golden Eagles with satellite radio transmitters to estimate the length of the post-fledging dependence period, survival during the post-fledging dependence period, and survival during the first year of independence. I identified 27 unique land cover types within nesting territories and found a negative relationship between the amount of Upland land cover and productivity; the probability of being a high production nesting territory decreased as the amount of the Upland land cover within a nesting territory increased. Satellite telemetry was useful for estimating the length of the post-fledging dependence period, fledgling survival, and first-year survival of Golden Eagles. The post-fledging dependence period of Golden Eagles in Denali is shorter than reported for Golden Eagles in temperate latitudes. Fledgling survival during the post-fledging dependence period was high and counts of fledglings made before actual fledging occurs provide realistic estimates of the reproductive success of Golden Eagles in Denali. First-year survival of Golden Eagles from Denali was lower than survival of Golden Eagles from temperature latitudes. By contrasting several models of survival using program MARK, I found evidence that Golden Eagles from single-fledgling broods had a higher first year survival rate than those from two-fledgling broods. Thus, productivity may not be a good predictor of survival of Golden Eagles in Denali

Infant feeding knowledge, perceptions and practices among women with and without HIV in Johannesburg, South Africa: a survey in healthcare facilities

BACKGROUND: South Africa has a history of low breastfeeding rates among women with and without Human Immunodeficiency Virus (HIV). In this study, we assessed infant feeding knowledge, perceptions and practices among pregnant and postpartum women with and without HIV, in the context of changes in infant feeding and Prevention of Mother-to-Child Transmission of HIV (PMTCT) guidelines. METHODS: This was a cross-sectional survey conducted from April 2014 to March 2015 in 10 healthcare facilities in Johannesburg, South Africa. A total of 190 pregnant and 180 postpartum women (74 and 67, respectively, were HIV positive) were interviewed using a semi-structured questionnaire. Multiple regression analyses assessed factors associated with an intention to exclusively breastfeed, and exclusive breastfeeding of infants less than six months of age. RESULTS: Women with HIV had better overall knowledge on safe infant feeding practices, both in general and in the context of HIV infection. There were however gaps in knowledge among women with and without HIV. Information from healthcare facilities was the main source of information for all groups of women in the study. A greater percentage of women without HIV 80.9% (93/115), reported an intention to exclusively breastfeed, compared to 64.9% (48/74) of women with HIV, p = 0.014. Not having HIV was positively associated with a reported intention to breastfeed, Adjusted Odds Ratio (AOR) 3.60, 95% CI 1.50, 8.62. Other factors associated with a reported intention to exclusively breastfeed were prior breastfeeding experience and higher knowledge scores on safe infant feeding practices in the context of HIV infection. Among postpartum women, higher scores on general knowledge of safe infant feeding practices were positively associated with reported exclusive breastfeeding, AOR 2.18, 95% CI 1.52, 3.12. Most women perceived that it was difficult to exclusively breastfeed and that cultural factors were a barrier to exclusive breastfeeding. CONCLUSIONS: While a greater proportion of women are electing to breastfeed, HIV infection and cultural factors remain an important influence on safe infant feeding practices. Healthcare workers are the main source of information, and highlight the need for accurate and consistent messaging for both women with and without HIV

Weather-driven change in primary productivity explains variation in the amplitude of two herbivore population cycles in a boreal system

Vertebrate populations throughout the circumpolar north often exhibit cyclic dynamics, and predation is generally considered to be a primary driver of these cycles in a variety of herbivore species. However, weather and climate play a role in entraining cycles over broad landscapes and may alter cyclic dynamics, although the mechanism by which these processes operate is uncertain. Experimental and observational work has suggested that weather influences primary productivity over multi-year time periods, suggesting a pathway through which weather and climate may influence cyclic herbivore dynamics. Using long-term monitoring data, we investigated the relationships among multi-year weather conditions, measures of primary productivity, and the abundance of two cyclic herbivore species: snowshoe hare and northern red-backed vole. We found that precipitation (rain and snow) and growing season temperatures were strongly associated with variation in primary productivity over multi-year time horizons. In turn, fourfold variation in the amplitude of both the hare and vole cycles observed in our study area corresponded to long-term changes in primary productivity. The congruence of our results for these two species suggests a general mechanism by which weather and climate might influence cyclic herbivore population dynamics. Our findings also suggested that the association between climate warming and the disappearance of cycles might be initiated by changes in primary productivity. This work provides an explanation for observed influences of weather and climate on primary productivity and population cycles and will help our collective understanding of how future climate warming may influence these ecological phenomena in the future.PostprintPeer reviewe

PPAR? Downregulation by TGF in Fibroblast and Impaired Expression and Function in Systemic Sclerosis: A Novel Mechanism for Progressive Fibrogenesis

The nuclear orphan receptor peroxisome proliferator-activated receptor-gamma (PPAR-γ) is expressed in multiple cell types in addition to adipocytes. Upon its activation by natural ligands such as fatty acids and eicosanoids, or by synthetic agonists such as rosiglitazone, PPAR-γ regulates adipogenesis, glucose uptake and inflammatory responses. Recent studies establish a novel role for PPAR-γ signaling as an endogenous mechanism for regulating transforming growth factor-ß (TGF-ß)- dependent fibrogenesis. Here, we sought to characterize PPAR-γ function in the prototypic fibrosing disorder systemic sclerosis (SSc), and delineate the factors governing PPAR-γ expression. We report that PPAR-γ levels were markedly diminished in skin and lung biopsies from patients with SSc, and in fibroblasts explanted from the lesional skin. In normal fibroblasts, treatment with TGF-ß resulted in a time- and dose-dependent down-regulation of PPAR-γ expression. Inhibition occurred at the transcriptional level and was mediated via canonical Smad signal transduction. Genome-wide expression profiling of SSc skin biopsies revealed a marked attenuation of PPAR-γ levels and transcriptional activity in a subset of patients with diffuse cutaneous SSc, which was correlated with the presence of a ''TGF-ß responsive gene signature'' in these biopsies. Together, these results demonstrate that the expression and function of PPAR-γ are impaired in SSc, and reveal the existence of a reciprocal inhibitory cross-talk between TGF-ß activation and PPAR-γ signaling in the context of fibrogenesis. In light of the potent anti-fibrotic effects attributed to PPAR-γ, these observations lead us to propose that excessive TGF-ß activity in SSc accounts for impaired PPAR-γ function, which in turn contributes to unchecked fibroblast activation and progressive fibrosis. © 2010 Wei et al

Circumpolar status of Arctic ptarmigan: population dynamics and trends

Rock ptarmigan (Lagopus muta) and willow ptarmigan (L. lagopus) are Arctic birds with a circumpolar distribution but there is limited knowledge about their status and trends across their circumpolar distribution. Here, we compiled information from 90 ptarmigan study sites from 7 Arctic countries, where almost half of the sites are still monitored. Rock ptarmigan showed an overall negative trend on Iceland and Greenland, while Svalbard and Newfoundland had positive trends, and no significant trends in Alaska. For willow ptarmigan, there was a negative trend in mid-Sweden and eastern Russia, while northern Fennoscandia, North America and Newfoundland had no significant trends. Both species displayed some periods with population cycles (short 3–6 years and long 9–12 years), but cyclicity changed through time for both species. We propose that simple, cost-efficient systematic surveys that capture the main feature of ptarmigan population dynamics can form the basis for citizen science efforts in order to fill knowledge gaps for the many regions that lack systematic ptarmigan monitoring programs.acceptedVersio

The effectiveness of interventions to change six health behaviours: a review of reviews

Background: Several World Health Organisation reports over recent years have highlighted the high incidence of chronic diseases such as diabetes, coronary heart disease and cancer. Contributory factors include unhealthy diets, alcohol and tobacco use and sedentary lifestyles. This paper reports the findings of a review of reviews of behavioural change interventions to reduce unhealthy behaviours or promote healthy behaviours. We included six different health-related behaviours in the review: healthy eating, physical exercise, smoking, alcohol misuse, sexual risk taking (in young people) and illicit drug use. We excluded reviews which focussed on pharmacological treatments or those which required intensive treatments (e. g. for drug or alcohol dependency). Methods: The Cochrane Library, Database of Abstracts of Reviews of Effectiveness (DARE) and several Ovid databases were searched for systematic reviews of interventions for the six behaviours (updated search 2008). Two reviewers applied the inclusion criteria, extracted data and assessed the quality of the reviews. The results were discussed in a narrative synthesis. Results: We included 103 reviews published between 1995 and 2008. The focus of interventions varied, but those targeting specific individuals were generally designed to change an existing behaviour (e. g. cigarette smoking, alcohol misuse), whilst those aimed at the general population or groups such as school children were designed to promote positive behaviours (e. g. healthy eating). Almost 50% (n = 48) of the reviews focussed on smoking (either prevention or cessation). Interventions that were most effective across a range of health behaviours included physician advice or individual counselling, and workplace- and school-based activities. Mass media campaigns and legislative interventions also showed small to moderate effects in changing health behaviours. Generally, the evidence related to short-term effects rather than sustained/longer-term impact and there was a relative lack of evidence on how best to address inequalities. Conclusions: Despite limitations of the review of reviews approach, it is encouraging that there are interventions that are effective in achieving behavioural change. Further emphasis in both primary studies and secondary analysis (e.g. systematic reviews) should be placed on assessing the differential effectiveness of interventions across different population subgroups to ensure that health inequalities are addressed.</p

The role of microRNA-155/liver X receptor pathway in experimental and idiopathic pulmonary fibrosis

Background: Idiopathic Pulmonary Fibrosis (IPF) is progressive and rapidly fatal. Improved understanding of pathogenesis is required to prosper novel therapeutics. Epigenetic changes contribute to IPF therefore microRNAs may reveal novel pathogenic pathways. Objectives: To determine the regulatory role of microRNA(miR)-155 in the pro-fibrotic function of murine lung macrophages and fibroblasts, IPF lung fibroblasts and its contribution to experimental pulmonary fibrosis. Methods: Bleomycin-induced lung fibrosis in wild-type and miR-155-/- mice was analyzed by histology, collagen and pro-fibrotic gene expression. Mechanisms were identified by in silico and molecular approaches; validated in mouse lung fibroblasts and macrophages, and in IPF lung fibroblasts, using loss-and-gain of function assays, and in vivo using specific inhibitors. Results: miR-155-/- mice developed exacerbated lung fibrosis, increased collagen deposition, collagen 1 and 3 mRNA expression, TGFβ production, and activation of alternatively-activated macrophages, contributed by deregulation of the microRNA-155 target gene the liver X receptor (LXR)α in lung fibroblasts and macrophages. Inhibition of LXRα in experimental lung fibrosis and in IPF lung fibroblasts reduced the exacerbated fibrotic response. Similarly, enforced expression of miR-155 reduced the pro-fibrotic phenotype of IPF and miR-155-/- fibroblasts. Conclusion: We describe herein a molecular pathway comprising miR-155 and its epigenetic LXRα target that when deregulated enables pathogenic pulmonary fibrosis. Manipulation of the miR-155/LXR pathway may have therapeutic potential for IPF

Genome-wide association of multiple complex traits in outbred mice by ultra low-coverage sequencing

The authors wish to acknowledge excellent technical assistance from A. Kurioka, L. Swadling, C. de Lara, J. Ussher, R. Townsend, S. Lionikaite, A.S. Lionikiene, R. Wolswinkel and I. van der Made. We would like to thank T.M. Keane and A.G. Doran for their help in annotating variants and adding the FVB/NJ strain to the MGP. We thank the High-Throughput Genomics Group at the Wellcome Trust Centre for Human Genetics and the Wellcome Trust Sanger Institute for the generation of the sequencing data. This work was funded by Wellcome Trust grant 090532/Z/09/Z (J.F.). Primary phenotyping of the mice was supported by the Mary Lyon Centre and Mammalian Genetics Unit (Medical Research Council, UK Hub grant G0900747 91070 and Medical Research Council, UK grant MC U142684172). D.A.B. acknowledges support from NIH R01AR056280. The sleep work was supported by the state of Vaud (Switzerland) and the Swiss National Science Foundation (SNF 14694 and 136201 to P.F.). The ECG work was supported by the Netherlands CardioVascular Research Initiative (Dutch Heart Foundation, Dutch Federation of University Medical Centres, Netherlands Organization for Health Research and Development and the Royal Netherlands Academy of Sciences) PREDICT project, InterUniversity Cardiology Institute of the Netherlands (ICIN; 061.02; C.A.R. and C.R.B.). N.C. is supported by the Agency of Science, Technology and Research (A*STAR) Graduate Academy. R.W.D. is supported by a grant from the Wellcome Trust (097308/Z/11/Z).Peer reviewedPostprin