732 research outputs found

    Simulations Reveal the Power and Peril of Articial Breeding Sites for Monitoring and Managing Animals

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    Despite common use, the efficacy of artificial breeding sites (e.g., nest boxes, bat houses, artificial burrows) as tools for monitoring and managing animals depends on the demography of target populations and availability of natural sites. Yet, the conditions enabling artificial breeding sites to be useful or informative have yet to be articulated. We use a stochastic simulation model to determine situations where artificial breeding sites are either useful or disadvantageous for monitoring and managing animals. Artificial breeding sites are a convenient tool for monitoring animals and therefore occupancy of artificial breeding sites is often used as an index of population levels. However, systematic changes in availability of sites that are not monitored might induce trends in occupancy of monitored sites, a situation rarely considered by monitoring programs. We therefore examine how systematic changes in unmonitored sites could bias inference from trends in the occupancy of monitored sites. Our model also allows us to examine effects on population levels if artificial breeding sites either increase or decrease population vital rates (survival and fecundity). We demonstrate that trends in occupancy of monitored sites are misleading if the number of unmonitored sites changes over time. Further, breeding site fidelity can cause an initial lag in occupancy of newly installed sites that could be misinterpreted as an increasing population, even when the population has been continuously declining. Importantly, provisioning of artificial breeding sites only benefits populations if breeding sites are limiting or if artificial sites increase vital rates. There are many situations where installation of artificial breeding sites, and their use in monitoring, can have unintended consequences. Managers should therefore not assume that provision of artificial breeding sites will necessarily benefit populations. Further, trends in occupancy of artificial breeding sites should be interpreted in light of potential changes in the availability of unmonitored sites and the potential of lags in occupancy owing to site fidelity

    Earlier Nesting by Generalist Predatory Bird is Associated with Human Responses to Climate Change

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    Warming temperatures cause temporal changes in growing seasons and prey abundance that drive earlier breeding by birds, especially dietary specialists within homogeneous habitat. Less is known about how generalists respond to climate-associated shifts in growing seasons or prey phenology, which may occur at different rates across land cover types. We studied whether breeding phenology of a generalist predator, the American kestrel (Falco sparverius), was associated with shifts in growing seasons and, presumably, prey abundance, in a mosaic of non-irrigated shrub/grasslands and irrigated crops/pastures. We examined the relationship between remotely-sensed normalized difference vegetation index (NDVI) and abundance of small mammals that, with insects, constitute approximately 93% of kestrel diet biomass. We used NDVI to estimate the start of the growing season (SoGS) in irrigated and non-irrigated lands from 1992 to 2015 and tested whether either estimate of annual SoGS predicted the timing of kestrel nesting. Finally, we examined relationships among irrigated SoGS, weather and crop planting. NDVI was a useful proxy for kestrel prey because it predicted small mammal abundance and past studies showed that NDVI predicts insect abundance. NDVI-estimated SoGS advanced significantly in irrigated lands (β = −1·09 ± 0·30 SE) but not in non-irrigated lands (β = −0·57 ± 0·53). Average date of kestrel nesting advanced 15 days in the past 24 years and was positively associated with the SoGS in irrigated lands, but not the SoGS in non-irrigated lands. Advanced SoGS in irrigated lands was related to earlier planting of crops after relatively warm winters, which were more common in recent years. Despite different patterns of SoGS change between land cover types, kestrel nesting phenology shifted with earlier prey availability in irrigated lands. Kestrels may preferentially track prey in irrigated lands over non-irrigated lands because of higher quality prey on irrigated lands, or earlier prey abundance may release former constraints on other selective pressures to breed early, such as seasonal declines in fecundity or competition for high-quality mates. This is one of the first examples of an association between human adaptation to climate change and shifts in breeding phenology of wildlife

    Commentary: Research Recommendations for Understanding the Decline of American Kestrels (\u3cem\u3eFalco sparverius\u3c/em\u3e) Across Much of North America

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    Across much of North America, populations of American Kestrels (Falco sparverius) have been in decline for decades (Farmer et al. 2008, Farmer and Smith 2009, Smallwood et al. 2009a, Paprocki et al. 2014, Sauer et al. 2014). Hypothesized causes of kestrel declines include predation by Cooper\u27s Hawks (Accipiter cooperii; Farmer et al. 2008), pathogens (e.g., Nemeth et al. 2006), habitat loss (Sullivan and Wood 2005, Farmer et al. 2008, Bolgiano et al. 2015), pesticides (Smallwood et al. 2009a, Rattner et al. 2015), and climate change (Steenhof and Peterson 2009b), yet no hypothesized factor has been supported empirically (Farmer et al. 2006, Smallwood et al. 2009a). Despite the effort spent evaluating threats, the lack of a “smoking-gun” to explain the decline of this charismatic species has led many professional and citizen scientists to call for action on several unlikely, and unsupported, threats. Here, we evaluate and build on hypothesized causes of declines considered by other authors (e.g., Sullivan and Wood 2005, Farmer et al. 2008, Smallwood et al. 2009a) to synthesize conclusions and articulate research needs

    Technoscience and the modernization of freshwater fisheries assessment and management

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    Inland fisheries assessment and management are challenging given the inherent com- plexity of working in diverse habitats (e.g., rivers, lakes, wetlands) that are dynamic on organisms that are often cryptic and where fishers are often highly mobile. Yet, technoscience is offering new tools that have the potential to reimagine how inland fisheries are assessed and managed. So-called ‘‘technoscience’’ refers to instances in which science and technology unfurl together, offering novel ways of spurring and achieving meaningful change. This paper considers the role of technoscience and its potential for modernizing the assessment and management of inland fisheries. It first explores technoscience and its potential benefits, followed by presentation of a series of synopses that explore the application (both successes and challenges) of new tech- nologies such as environmental DNA (eDNA), genomics, electronic tags, drones, phone apps, iEcology, and artificial intelligence to assessment and management. The paper also considers the challenges and barriers that exist in adopting new technologies. The paper concludes with a provocative assessment of the potential of technoscience to reform and modernize inland fisheries assessment and management. Although these tools are increasingly being embraced, there is a lack of platforms for aggregating these data streams and providing managers with actionable information in a timely manner. The ideas presented here should serve as a catalyst for beginning to work collectively and collaboratively towards fisheries assessment and management systems that harness the power of technology and serve to modernize inland fisheries management. Such transformation is urgently needed given the dynamic nature of environmental change, the evolving threat matrix facing inland waters, and the complex behavior of fishers. Quite simply, a dynamic world demands dynamic fisheries management; technoscience has made that within reach.publishedVersio

    Habitable Zones and UV Habitable Zones around Host Stars

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    Ultraviolet radiation is a double-edged sword to life. If it is too strong, the terrestrial biological systems will be damaged. And if it is too weak, the synthesis of many biochemical compounds can not go along. We try to obtain the continuous ultraviolet habitable zones, and compare the ultraviolet habitable zones with the habitable zones of host stars. Using the boundary ultraviolet radiation of ultraviolet habitable zone, we calculate the ultraviolet habitable zones of host stars with masses from 0.08 to 4.00 \mo. For the host stars with effective temperatures lower than 4,600 K, the ultraviolet habitable zones are closer than the habitable zones. For the host stars with effective temperatures higher than 7,137 K, the ultraviolet habitable zones are farther than the habitable zones. For hot subdwarf as a host star, the distance of the ultraviolet habitable zone is about ten times more than that of the habitable zone, which is not suitable for life existence.Comment: 5 pages, 3 figure

    Influence of Anodic Conditions on Self-ordered Growth of Highly Aligned Titanium Oxide Nanopores

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    Self-aligned nanoporous TiO2templates synthesized via dc current electrochemical anodization have been carefully analyzed. The influence of environmental temperature during the anodization, ranging from 2 °C to ambient, on the structure and morphology of the nanoporous oxide formation has been investigated, as well as that of the HF electrolyte chemical composition, its concentration and their mixtures with other acids employed for the anodization. Arrays of self-assembled titania nanopores with inner pores diameter ranging between 50 and 100 nm, wall thickness around 20–60 nm and 300 nm in length, are grown in amorphous phase, vertical to the Ti substrate, parallel aligned to each other and uniformly disordering distributed over all the sample surface. Additional remarks about the photoluminiscence properties of the titania nanoporous templates and the magnetic behavior of the Ni filled nanoporous semiconductor Ti oxide template are also included

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

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    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

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    A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

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    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

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    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO
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