24 research outputs found

    Why discrepancies in searching the conservation biology literature matter

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    Conservation biologists seek as much information as possible for evidence-based conservation actions, so they have a special concern for variations in literature retrieval. We assessed the significance for biological conservation of differences in literature retrieval across databases by comparing five simple subject searches in Scopus, Web of Science (WoS) (comparing two different subscriptions), Web of Science (Core Collection) (WosCC) (comparing two different subscriptions) and Google Scholar (GS). The efficiency of a search (the number of references retrieved by a database as a percentage of the total number retrieved across all databases) ranged from 5% to 92%. Different subscriptions to WoS and WoSCC returned different numbers of references. Additionally, we asked 114 conservation biologists which databases they used, their awareness of differing search options within databases and their awareness of different subscription options. The four most widely used databases were GS (88%), WoS (59%), WoSCC (58%) and Scopus (27%). Most respondents (≥ 65%) were unsure about specific features in databases, although 66% knew of the service GS Citations, and 76% agreed that GS retrieved grey literature effectively. Respondents' publication history did not influence their responses. Researchers seeking comprehensive literature reviews should consult multiple databases, with online searches using GS important for locating books, book chapters and grey literature. Comparative evaluations of publication outputs of researchers or departments are susceptible to variations in content between databases and different subscriptions of the same database, so researchers should justify the databases used and, if applicable, the subscriptions. Students value convenience over thoroughness in literature searches, so relevant education is needed

    The Fueling and Evolution of AGN: Internal and External Triggers

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    In this chapter, I review the fueling and evolution of active galactic nuclei (AGN) under the influence of internal and external triggers, namely intrinsic properties of host galaxies (morphological or Hubble type, color, presence of bars and other non-axisymmetric features, etc) and external factors such as environment and interactions. The most daunting challenge in fueling AGN is arguably the angular momentum problem as even matter located at a radius of a few hundred pc must lose more than 99.99 % of its specific angular momentum before it is fit for consumption by a BH. I review mass accretion rates, angular momentum requirements, the effectiveness of different fueling mechanisms, and the growth and mass density of black BHs at different epochs. I discuss connections between the nuclear and larger-scale properties of AGN, both locally and at intermediate redshifts, outlining some recent results from the GEMS and GOODS HST surveys.Comment: Invited Review Chapter to appear in LNP Volume on "AGN Physics on All Scales", Chapter 6, in press. 40 pages, 12 figures. Typo in Eq 5 correcte

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990�2015: a systematic analysis for the Global Burden of Disease Study 2015

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    Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors�the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25 over the same period. All risks jointly evaluated in 2015 accounted for 57·8 (95 CI 56·6�58·8) of global deaths and 41·2 (39·8�42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million 192·7 million to 231·1 million global DALYs), smoking (148·6 million 134·2 million to 163·1 million), high fasting plasma glucose (143·1 million 125·1 million to 163·5 million), high BMI (120·1 million 83·8 million to 158·4 million), childhood undernutrition (113·3 million 103·9 million to 123·4 million), ambient particulate matter (103·1 million 90·8 million to 115·1 million), high total cholesterol (88·7 million 74·6 million to 105·7 million), household air pollution (85·6 million 66·7 million to 106·1 million), alcohol use (85·0 million 77·2 million to 93·0 million), and diets high in sodium (83·0 million 49·3 million to 127·5 million). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation. © 2016 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY licens

    A Colour atlas of human anatomy

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    Micro-Costing in Public Health Economics: Steps Towards a Standardized Framework, Using the Incredible Years Toddler Parenting Program as a Worked Example

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    Complex interventions, such as parenting programs, are rarely evaluated from a public sector, multi-agency perspective. An exception is the Incredible Years (IY) Basic Parenting Program; which has a growing clinical and cost-effectiveness evidence base for preventing or reducing children�s conduct problems. The aim of this paper was to provide a micro-costing framework for use by future researchers, by micro-costing the 12-session IY Toddler Parenting Program from a public sector, multi-agency perspective. This micro-costing was undertaken as part of a community-based randomized controlled trial of the program in disadvantaged Flying Start areas in Wales, U.K. Program delivery costs were collected by group leader cost diaries. Training and supervision costs were recorded. Sensitivity analysis assessed the effects of a London cost weighting and group size. Costs were reported in 2008/2009 pounds sterling. Direct program initial set-up costs were £3305.73; recurrent delivery costs for the program based on eight parents attending a group were £752.63 per child, falling to £633.61 based on 10 parents. Under research contexts (with weekly supervision) delivery costs were £1509.28 per child based on eight parents, falling to £1238.94 per child based on 10 parents. When applying a London weighting, overall program costs increased in all contexts. Costs at a micro-level must be accurately calculated to conduct meaningful cost-effectiveness/cost-benefit analysis. A standardized framework for assessing costs is needed; this paper outlines a suggested framework. In prevention science it is important for decision makers to be aware of intervention costs in order to allocate scarce resources effectively
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