139 research outputs found
Integrating remote sensing and species' traits to assess bird responses to wildfire in agropastoral landscapes
No full textThe climate-induced increase in wildfires has made them a critical research priority for biodiversity in Europe. Yet, studies leveraging species traits to explain varying responses to wildfires and inform targeted conservation efforts remain limited. To address this gap, we surveyed bird communities one-year post-wildfire across a 4450-hectare burnt and adjacent unburnt agropastoral landscape in the Classic Karst, a protected area spanning Italy and Slovenia undergoing reductions in agropastoral farming. Remote sensing data and machine learning were employed to map wildfire severity and finely classify bird-habitat associations based on 139 bird point counts. Wildfire substantially reduced woody biomass and was associated with lower bird species richness (mean/point = 5.09 SE ± 0.22) and abundance (mean/point = 6.69 SE ± 0.35) compared to unburnt areas (richness mean/point = 6.43 SE ± 0.22; abundance mean/point = 8.71 SE ± 0.32). However, its impacts varied considerably depending on species traits. Among the species with the lowest post-fire occurrences were high shrub and forest-dwelling birds that rely on vegetation cover, particularly those with open-cup nests and branch-edge foraging behaviours. Conversely, cavity nesters and trunk/bark foragers were more frequent in burned areas, potentially due to the structural resilience of their nests and the post-fire availability of saproxylic invertebrates. Some semi-open habitat species of conservation concern, particularly those employing ground-nesting and ground-foraging strategies, also showed increased occurrence in burnt areas. Smaller-bodied species were more frequently detected in heterogeneous unburned shrub patches, consistent with the Textural Discontinuity Hypothesis. Resident/short-distance migrants appeared less affected than long-distance migrants, probably due to their continuous or partial presence year-round. Our results highlight the value of combining trait-based and remote sensing analysis to identifying species responses following wildfire, providing critical insights for conservation strategies that aim to balance the needs of both open-habitat and forest species in Mediterranean fire-prone landscapes
Measurement of the charm-mixing parameter y(CP) in D-0 -> K-S(0)omega decays at Belle
No full textWe report the first measurement of the charm-mixing parameter y(CP) in D-0 decays to the CP-odd final state K-S(0 omega). The study uses the full Belle e(+)e(-) annihilation data sample of 976 fb(-1) taken at or near the gamma (4S) centre-of-mass energy. We find y(CP) = (0.96 +/- 0.91 +/- 0.62(-0.00)+0.17)%, where the first uncertainty is statistical, the second is systematic due to event selection and background, and the last is due to possible presence of CP-even decays in the data sample.LPH
Search for and at = 10.52, 10.58, and 10.867 GeV
No full textInternational audienceThe first search for double charged charmoniumlike state production in ϒ(1S) and ϒ(2S) decays and in e+e- annihilation at s=10.52, 10.58, and 10.867 GeV is conducted using data collected with the Belle detector at the KEKB asymmetric energy electron-positron collider. No significant signals are observed in any of the studied modes, and the 90% credibility level upper limits on their product branching fractions in ϒ(1S) and ϒ(2S) decays [B(ϒ(1S,2S)→Zc+Zc(′)-)×B(Zc+→π++cc¯) (cc¯=J/ψ, χc1(1P), ψ(2S))] and the product of Born cross section and branching fraction for e+e-→Zc+Zc(′)- (σ(e+e-→Zc+Zc(′)-)×B(Zc+→π++cc¯)) at s=10.52, 10.58, and 10.867 GeV are determined. Here, Zc refers to the Zc(3900) and Zc(4200) observed in the πJ/ψ final state, the Zc1(4050) and Zc2(4250) in the πχc1(1P) final state, and the Zc(4050) and Zc(4430) in the πψ(2S) final state
Evidence for a mixed mass composition at the ‘ankle’ in the cosmic-ray spectrum
No full textWe report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the ‘ankle’ at lg(E/eV)=18.5–19.0lg(E/eV)=18.5–19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A>4A>4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth
WATER MANAGEMENT OF THE CLASSICAL KARST AQUIFER (NE ITALY, SW SLOVENIA)
No full textClassical Karst is a broad area located between the north-eastern Italian sector and the south-western Slovenian side. The area is about 40 km long and 15 wide (SE-NW
direction) bounded by the Isonzo/Soča and Vipacco/Vipava rivers, by the Pivka River basin, Cicarija structure and the Gulf of Trieste. The plateau, slightly inclined towards NW, consists of limestone lithotypes deeply karstified. Rainfall and surface waters are immediately swallowed by the karst bedrock, where a network of caves is developed, transferring
vertically the waters through the epikarst and vadose zone and collecting them in the aquifer characterized by large horizontal or sub-horizontal conduits quickly transporting the waters to the spring’s area. Data analysis obtained from Classical Karst groundwater monitoring networks highlights the complexity of the hydrostructure. In this framework, the Hydrokarst Project (Italy-Slovenia’s transboundary cooperation program 2007-2013), is focused on the joint protection and management of the transboundary aquifer through quantitative and qualitative monitoring.
One of Hydrokarst’s outputs is the shared GeoDatabase collecting all the available and newly obtained geological, hydrological, hydrodynamic, geochemical and biological data. Unified maps as the Integrated Vulnerability Map obtained from the collected, validated and analyzed data are the common base to prepare cooperation agreements able to promote and implement action focused on the protection areas identification and realization. This common vision implements strategies able to prevent and/or reduce risks in emergencies. In this framework, also the support to the water consumption’s reduction as the efficiency of the water network management and the improvement of drinking water quality, guarantee, to the future generations, an abundance of good quality waters
Measurement of time-dependent asymmetries in decays
No full textInternational audienceWe report a measurement of time-dependent CP violation parameters in B0→KS0ηγ decays. The study is based on a data sample, containing 772×106BB¯ pairs, that was collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the CP violation parameters of S=-1.32±0.77(stat)±0.36(syst) and A=-0.48±0.41(stat)±0.07(syst) for the invariant mass of the KS0η system up to 2.1 GeV/c2
Erratum: Search for photons with energies above 1018 eV using the hybrid detector of the Pierre Auger Observatory
No full textExposure calculation Due to a mistake in the numerical integration following eq. (6.2) of the original article [1], the exposure shown in figure 5 of the original article was incorrect. The correct exposure is shown in figure 1. 2 Upper limits on the integral photon flux and fraction The incorrect exposure affects the calculation of the upper limits on the integral photon flux following eq. (6.1) of the original article. The correct values for the upper limits are 0.038, 0.010, 0.009, 0.008 and 0.007 km−2 sr−1 yr−1 for threshold energies of 1, 2, 3, 5 and 10 EeV. The correct values for the upper limits on the integral photon fraction subsequently derived are 0.14 %, 0.17 %, 0.42 %, 0.86 % and 2.9 % for the same threshold energies. 3 Author list The author list of this erratum also corrects a mistake made in the original article, where F. Zuccarello was missing and Z. Zong was listed twice
Measurement of time-dependent violation parameters in decays at Belle
No full textInternational audienceWe measure the time-dependent CP violation parameters in B0→KS0KS0KS0 decays using 772×106BB¯ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. The obtained mixing-induced and direct CP asymmetries are -0.71±0.23 (stat)±0.05 (syst) and 0.12±0.16 (stat)±0.05 (syst), respectively. These values are consistent with the Standard Model predictions. The significance of CP violation differs from zero by 2.5 standard deviations
Prospects for -ray observations of the Perseus galaxy cluster with the Cherenkov Telescope Array
No full textGalaxy clusters are expected to be dark matter (DM) reservoirs and storage rooms for the cosmic-ray protons (CRp) that accumulate along the cluster\u27s formation history. Accordingly, they are excellent targets to search for signals of DM annihilation and decay at gamma-ray energies and are predicted to be sources of large-scale gamma-ray emission due to hadronic interactions in the intracluster medium. We estimate the sensitivity of the Cherenkov Telescope Array (CTA) to detect diffuse gamma-ray emission from the Perseus galaxy cluster. We perform a detailed spatial and spectral modelling of the expected signal for the DM and the CRp components. For each, we compute the expected CTA sensitivity. The observing strategy of Perseus is also discussed. In the absence of a diffuse signal (non-detection), CTA should constrain the CRp to thermal energy ratio within the radius down to about s for DM masses above 1 TeV. These constraints will provide unprecedented sensitivity to the physics of both CRp acceleration and transport at cluster scale and to TeV DM particle models, especially in the decay scenario.93 pages (including author list, appendix and references), 143 figures. Submitted to JCA
Search for the decay <math display="inline"><msubsup><mi>B</mi><mi>s</mi><mn>0</mn></msubsup><mo stretchy="false">→</mo><msup><mi>η</mi><mo>′</mo></msup><msubsup><mi>K</mi><mi>S</mi><mn>0</mn></msubsup></math>
No full textInternational audienceWe report the results of the first search for the decay Bs0→η′KS0 using 121.4 fb-1 of data collected at the ϒ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We observe no signal and set a 90% confidence-level upper limit of 8.16×10-6 on the Bs0→η′KS0 branching fraction
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