24,742 research outputs found

    Response of Bird Populations to Long-term Changes in Local Vegetation and Regional Forest Cover

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    We analyzed data from a woodland site for a 59-year period to determine whether changes in bird populations are related to changes in the diversity and relative abundance of woody plant species even when vegetation structure, degree of forest fragmentation in the surrounding landscape, and regional changes in bird populations are taken into account. Principal component analyses generated vegetation factors encompassing variables such as total basal area, shrub density, basal area of common tree species, and measures of tree and shrub species diversity. We also calculated a forest edge/ forest area index based on GIS analysis of the landscape within 2 km of the study site. Poisson regression models revealed relationships between these covariates and population changes for 19 bird species and for seven groups of species characterized by similar migration strategies or habitat requirements. All groups of habitat specialists showed a positive relationship with the first vegetation factor, which indicates that they declined as total basal area and dominance of oaks and maples increased and as tree and shrub diversity decreased. This suggests that floristic diversity may be important for determining habitat quality. Bird species associated with the shrub layer and with hemlock stands showed positive relationships with the second vegetation factor, suggesting that the recent decline in eastern hemlocks (Tsuga canadensis) because of hemlock woolly adelgid (Adelges tsugae) had an adverse impact on these species. Forest migrants, shrub-layer specialists, long-distance migrants and permanent residents showed negative relationships with the forest edge/forest interior index, indicating that conservation efforts to protect bird communities should take the wider landscape into account. The strongest relationship for most species and species groups was with the first vegetation factor, which suggests that species composition and diversity of trees and shrubs may be especially important in determining abundance of many forest bird species

    The International Health Regulations 10 Years On: The Governing Framework for Global Health Security

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    The World Health Organization (WHO) and its global health security treaty, the International Health Regulations (2005) (IHR) have lost the world\u27s confidence after the West African Ebola epidemic. The epidemic led to several high-level reviews of the IHR and global health security more broadly. Here, we propose a series of recommendations for operational and legal reforms to enhance the functioning of the FCGH. It is critical that WHO act on them quickly, before the window of opportunity for fundamental reform closes. WHO should ensure that all states fulfill their obligations to develop national core surveillance and response capacities, including through funding, possibly through additional assessed contributions, and an independent peer-review assessment process, with assessments identifying gaps and strategies and financing to fill those gaps. Civil society could also participate in ensure the validity of assessments. Independent assessments will improve confidence in the IHR, as would increasing the transparency of Emergency Committees deliberations, supplemented by an independent body to review disease data and offer recommendations to the WHO Director-General. States might more promptly notify WHO of events that may constitute public health emergencies of international concern with enhanced training and if the IHR\u27s decision instrument is amended to make more diseases automatically notifiable. WHO should also further encourage and facilitate reporting from non-governmental sources. A harmonized, gradient system for health emergencies would also bring greater clarity to disease response, while maintaining the power of a declaration of a public health emergency of international concern. To improve compliance with temporary recommendations and deter harmful additional measures, WHO could use public pressure, acknowledging compliance while publicly naming states parties and businesses that fail to comply, along with requesting justification for additional measures. States could use dispute mediation, arbitration, or other legal procedures, such as through the World Trade Organization, to discourage harmful trade and travel restrictions. And to advance a One Health approach, based on the links between human, animal, and environmental health, WHO should increase its use of cooperative agreements with other intergovernmental bodies, while integrating the Pandemic Influenza Pandemic Framework with the IHR to encourage equitable sharing of vaccines and therapies

    Prevalence of Bacteria of Division TM7 in Human Subgingival Plaque and Their Association with Disease

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    Members of the uncultivated bacterial division TM7 have been detected in the human mouth, but little information is available regarding their prevalence and diversity at this site. Human subgingival plaque samples from healthy sites and sites exhibiting various stages of periodontal disease were analyzed for the presence of TM7 bacteria. TM7 ribosomal DNA (rDNA) was found in 96% of the samples, and it accounted for approximately 0.3%, on average, of all bacterial rDNA in the samples as determined by real-time quantitative PCR. Two new phylotypes of this division were identified, and members of the division were found to exhibit filamentous morphology by fluorescence in situ hybridization. The abundance of TM7 rDNA relative to total bacterial rDNA was higher in sites with mild periodontitis (0.54% ± 0.1%) than in either healthy sites (0.21% ± 0.05%, P \u3c 0.01) or sites with severe periodontitis (0.29% ± 0.06%, P \u3c 0.05). One division subgroup, the I025 phylotype, was detected in 1 of 18 healthy samples and 38 of 58 disease samples. These data suggest that this phylotype, and the TM7 bacterial division in general, may play a role in the multifactorial process leading to periodontitis

    The structure of degradable quantum channels

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    Degradable quantum channels are among the only channels whose quantum and private classical capacities are known. As such, determining the structure of these channels is a pressing open question in quantum information theory. We give a comprehensive review of what is currently known about the structure of degradable quantum channels, including a number of new results as well as alternate proofs of some known results. In the case of qubits, we provide a complete characterization of all degradable channels with two dimensional output, give a new proof that a qubit channel with two Kraus operators is either degradable or anti-degradable and present a complete description of anti-degradable unital qubit channels with a new proof. For higher output dimensions we explore the relationship between the output and environment dimensions (dBd_B and dEd_E respectively) of degradable channels. For several broad classes of channels we show that they can be modeled with a environment that is "small" in the sense dE≤dBd_E \leq d_B. Perhaps surprisingly, we also present examples of degradable channels with ``large'' environments, in the sense that the minimal dimension dE>dBd_E > d_B. Indeed, one can have dE>14dB2d_E > \tfrac{1}{4} d_B^2. In the case of channels with diagonal Kraus operators, we describe the subclass which are complements of entanglement breaking channels. We also obtain a number of results for channels in the convex hull of conjugations with generalized Pauli matrices. However, a number of open questions remain about these channels and the more general case of random unitary channels.Comment: 42 pages, 3 figures, Web and paper abstract differ; (v2 contains only minor typo corrections

    Variability of Objectively Measured Sedentary Behavior

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    The primary purpose of this study was to evaluate variability of sedentary behavior (SB) throughout a 7-d measurement period and to determine if G7 d of SB measurement would be comparable with the typical 7-d measurement period. Methods: Retrospective data from Ball State University_s Clinical Exercise Physiology Laboratory on 293 participants (99 men, 55 T 14 yr, body mass index = 29 T 5 kgImj2; 194 women, 51 T 12 yr, body mass index = 27 T 7 kgImj2) with seven consecutive days of data collected with ActiGraph accelerometers were analyzed (ActiGraph, Fort Walton Beach, FL). Time spent in SB (either G100 counts per minute or G150 counts per minute) and breaks in SB were compared between days and by sex using a two-way repeated-measures ANOVA. Stepwise regression was performed to determine if G7 d of SB measurement were comparable with the 7-d method, using an adjusted R2 of Q0.9 as a criterion for equivalence. Results: There were no differences in daily time spent in SB between the 7 d for all participants. However, there was a significant interaction between sex and days, with women spending less time in SB on both Saturdays and Sundays than men when using the 100 counts per minute cut-point. Stepwise regression showed using any 4 d would be comparable with a 7-d measurement (R2 9 0.90). Conclusions: When assessed over a 7-d measurement period, SB appears to be very stable from day to day, although there may be some small differences in time spent in SB and breaks in SB between men and women, particularly on weekend days. The stepwise regression analysis suggests that a measurement period as short as 4 d could provide comparable data (91% of variance) with a 1-wk assessment. Shorter assessment periods would reduce both researcher and subject burden in data collection
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