2,160 research outputs found
Habitat Preferences of Italian Freshwater Fish: A Systematic Review of Data Availability for Applications of the MesoHABSIM Model
The MesoHABitat SImulation Model (MesoHABSIM) is the preferred method to calculate spatio-temporal variation in the fish habitat availability in Italian rivers. With the aim of improving the applicability of the MesoHABSIM approach in the Italian territory, we carried out a systematic review of physical habitat preferences for 31 freshwater fish species and three freshwater lampreys, representing 75% of the total indigenous freshwater fish community of Italy. Information related to suitable ranges of depth, flow velocity, biotic/abiotic substrates, covers/shelters was collected and summarized for two critical life stages (adult and juvenile) and two bioperiods (rearing/growth and spawning). Overall, 250 publications were reviewed, classified as 206 peer-reviewed papers, 20 books, 7 PhD thesis, and 17 grey literature sources. Our analysis revealed substantial deficits of information about habitat requirements for more than 30% of Italian freshwater fish species. This information is particularly scarce for the most threatened endemic species, especially for their most critical bioperiod (i.e., spawning). With the aim of preserving freshwater fish biodiversity as required in the EU Biodiversity Strategy for 2030 (European Commission, 2020), accurate information on physical habitat requirements for spawning is crucial. As an example application of MesoHABSIM, the collected habitat preference information was used to define and apply mesohabitat suitability criteria for one fish species (Telestes muticellus) in a regulated river reach of Argentina Creek (Province of Imperia, Italy). This analysis demonstrates the potential for applying information from the current review to other fish species
u-RANIA: a neutron detector based on \mu -RWELL technology
In the framework of the ATTRACT-uRANIA project, funded by the European
Community, we are developing an innovative neutron imaging detector based on
micro-Resistive WELL ( -RWELL) technology. The -RWELL, based on the
resistive detector concept, ensuring an efficient spark quenching mechanism, is
a highly reliable device. It is composed by two main elements: a readout-PCB
and a cathode. The amplification stage for this device is embedded in the
readout board through a resistive layer realized by means of an industrial
process with DLC (Diamond-Like Carbon). A thin layer of BC on the copper
surface of the cathode allows the thermal neutrons detection through the
release of Li and particles in the active volume. This technology
has been developed to be an efficient and convenient alternative to the He
shortage. The goal of the project is to prove the feasibility of such a novel
neutron detector by developing and testing small planar prototypes with readout
boards suitably segmented with strip or pad read out, equipped with existing
electronics or readout in current mode. Preliminary results from the test with
different prototypes, showing a good agreement with the simulation, will be
presented together with construction details of the prototypes and the future
steps of the project.Comment: Prepared for the INSTR20 Conference Proceeding for JINS
Electoral Dioramas: On the Problem of Representation in Voting Advice Applications
Voting Advice Applications (VAAs) are online tools designed to help citizens decide how to vote. They typically offer their users a representation of what is at stake in an election by matching user preferences on issues with those of parties or candidates. While the use of VAAs has boomed in recent years in both established and new democracies, this new phenomenon in the electoral landscape has received little attention from political theorists. The current academic debate is focused on epistemic aspects of the question how a VAA can adequately represent electoral politics. We argue that conceptual and normative presuppositions at play in the background of the tool are at least as important. Even a well-developed VAA does not simply reflect what is at stake in the election by neutrally passing along information. Rather, it structures political information in a way that is informed by the developers’ presuppositions. Yet, these presuppositions remain hidden if we interpret the tool as a mirror that offers the user a reflection of him/herself situated within the political landscape. VAAs should therefore be understood as electoral dioramas, staged according to a contestable picture of politics
A model to explain angular distributions of and decays into and
BESIII data show a particular angular distribution for the decay of the
and mesons into the hyperons
and . More in details the angular distribution of
the decay exhibits an opposite trend
with respect to that of the other three channels: , and
. We define a model to explain the
origin of this phenomenon.Comment: 6 pages, 7 figures, to be published in Chinese Physics
A Cylindrical GEM Inner Tracker for the BESIII experiment at IHEP
The Beijing Electron Spectrometer III (BESIII) is a multipurpose detector
that collects data provided by the collision in the Beijing Electron Positron
Collider II (BEPCII), hosted at the Institute of High Energy Physics of
Beijing. Since the beginning of its operation, BESIII has collected the world
largest sample of J/{\psi} and {\psi}(2s). Due to the increase of the
luminosity up to its nominal value of 10^33 cm-2 s-1 and aging effect, the MDC
decreases its efficiency in the first layers up to 35% with respect to the
value in 2014. Since BESIII has to take data up to 2022 with the chance to
continue up to 2027, the Italian collaboration proposed to replace the inner
part of the MDC with three independent layers of Cylindrical triple-GEM (CGEM).
The CGEM-IT project will deploy several new features and innovation with
respect the other current GEM based detector: the {\mu}TPC and analog readout,
with time and charge measurements will allow to reach the 130 {\mu}m spatial
resolution in 1 T magnetic field requested by the BESIII collaboration. In this
proceeding, an update of the status of the project will be presented, with a
particular focus on the results with planar and cylindrical prototypes with
test beams data. These results are beyond the state of the art for GEM
technology in magnetic field
Measurement of Branching Fractions and Rate Asymmetries in the Rare Decays B -> K(*) l+ l-
In a sample of 471 million BB events collected with the BABAR detector at the
PEP-II e+e- collider we study the rare decays B -> K(*) l+ l-, where l+ l- is
either e+e- or mu+mu-. We report results on partial branching fractions and
isospin asymmetries in seven bins of di-lepton mass-squared. We further present
CP and lepton-flavor asymmetries for di-lepton masses below and above the J/psi
resonance. We find no evidence for CP or lepton-flavor violation. The partial
branching fractions and isospin asymmetries are consistent with the Standard
Model predictions and with results from other experiments.Comment: 16 pages, 14 figures, accepted by Phys. Rev.
Recommended from our members
Measurement of B(B-->X_s {\gamma}), the B-->X_s {\gamma} photon energy spectrum, and the direct CP asymmetry in B-->X_{s+d} {\gamma} decays
The photon spectrum in B --> X_s {\gamma} decay, where X_s is any strange
hadronic state, is studied using a data sample of (382.8\pm 4.2) \times 10^6
e^+ e^- --> \Upsilon(4S) --> BBbar events collected by the BABAR experiment at
the PEP-II collider. The spectrum is used to measure the branching fraction B(B
--> X_s \gamma) = (3.21 \pm 0.15 \pm 0.29 \pm 0.08)\times 10^{-4} and the
first, second, and third moments = 2.267 \pm 0.019 \pm 0.032 \pm
0.003 GeV,, )^2> = 0.0484 \pm 0.0053 \pm 0.0077 \pm
0.0005 GeV^2, and )^3> = -0.0048 \pm 0.0011 \pm 0.0011
\pm 0.0004 GeV^3, for the range E_\gamma > 1.8 GeV, where E_{\gamma} is the
photon energy in the B-meson rest frame. Results are also presented for
narrower E_{\gamma} ranges. In addition, the direct CP asymmetry A_{CP}(B -->
X_{s+d} \gamma) is measured to be 0.057 \pm 0.063. The spectrum itself is also
unfolded to the B-meson rest frame; that is the frame in which theoretical
predictions for its shape are made.Comment: 37 pages, 19 postscript figures, submitted to Phys. Rev. D. No
analysis or results have changed from previous version. Some changes to
improve clarity based on interactions with Phys. Rev. D referees, including
one new Figure (Fig. 13), and some minor wording/punctuation/spelling
mistakes fixe
- …