76 research outputs found
Beneficial effects of bunch-zone late defoliations and shoot positioning on berry composition and colour components of wines undergoing aging in an organically-managed and rainfed Sangiovese vineyard
n the context of climate change, where high temperatures are frequent in the first phases of ripening, protecting grapevine bunches from solar radiation is essential for preserving berry composition and wine colour. The effects of bunch-zone late defoliations (DEFs) and “semi-ballerina” shoot positioning (SB) on vine physiology and grape and wine quality of organic cv. Sangiovese wines during storage were assessed in two contrasting seasons (2013 and 2014). The treatments altered neither vine physiology (leaf photosynthetic activity and stomatal conductance, stem water potential) nor vine phenology, yield, budburst and fruitfulness. Defoliations imposed at post-veraison (DEF I) and pre-harvest (DEF II), but not shoot positioning imposed at post-veraison, enhanced the concentration of berry skin flavonols at harvest, compared to an untreated control. Late defoliations and SB did not change berry weight, anthocyanins, soluble solids, pH or titratable acidity at harvest.
The severity of Botrytis bunch rot was assessed in both seasons. In 2013, it was negligible regardless of the treatment.
In 2014 (characterised by higher rainfall and lower average temperatures than in 2013), late defoliations (DEF I and DEF II), especially DEF I, and SB to a minor extent, limited the severity of Botrytis bunch rot. The oenological benefits of late defoliations and shoot positioning were observed during wine storage. These canopy management practices positively influenced wine components (polymeric pigments; namely short polymeric pigments) that might have a marked effect on the final colour intensity, without altering the basic chemical characteristics of the wine. When choosing the timing for carrying out defoliation in order to improve grape quality and bunch rot containment, the meteorological conditions should be properly considered. Our results may contribute to providing further recommendations for canopy management for grape growers who produce organic Sangiovese wines that undergo aging
Mortality attributable to COVID-19 in nursing home residents: a retrospective study
Aim: Coronavirus-19 disease (COVID-19) is a widespread condition in nursing home (NH). It is not known whether COVID-19 is associated with a higher risk of death than residents without COVID-19. Therefore, the aim of this study was to assess whether COVID-19 is associated with a higher mortality rate in NH residents, considering frailty status assessed with the Multidimensional Prognostic Index (MPI). Methods: In this retrospective study, made in 31 NHs in Venice, Italy, the presence of COVID-19 was ascertained with a nasopharyngeal swab. Frailty was evaluated using the MPI, modified according to the tools commonly used in our NHs. A Cox’s regression analysis was used reporting the results as hazard ratios (HRs) with 95% confidence intervals (CIs), using COVID-19 as exposure and mortality as outcome and stratified by MPI tertiles. Similar analyses were run using MPI tertiles as exposure. Results: Overall, 3946 NH residents (median age = 87 years, females: 73.9%) were eligible, with 1136 COVID-19 +. During a median follow-up of 275 days, higher values of MPI, indicating frailer people, were associated with an increased risk of mortality. The incidence of mortality in COVID-19 + was more than doubled than COVID-19- either in MPI-1, MPI-2 and MPI-3 groups. The presence of COVID-19 increased the risk of death (HR = 1.85; 95% CI 1.59–2.15), also in the propensity score model using MPI as confounder (HR = 2.48; 95% CI 2.10–2.93). Conclusion: In this retrospective study of NH residents, COVID-19 was associated with a higher risk of all-cause mortality than those not affected by COVID-19 also considering the different grades of frailty. © 2021, The Author(s)
Evidence for Quark-Hadron Duality in the Proton Spin Asymmetry
Spin-dependent lepton-nucleon scattering data have been used to investigate
the validity of the concept of quark-hadron duality for the spin asymmetry
. Longitudinally polarised positrons were scattered off a longitudinally
polarised hydrogen target for values of between 1.2 and 12 GeV and
values of between 1 and 4 GeV. The average double-spin asymmetry in
the nucleon resonance region is found to agree with that measured in
deep-inelastic scattering at the same values of the Bjorken scaling variable
. This finding implies that the description of in terms of quark
degrees of freedom is valid also in the nucleon resonance region for values of
above 1.6 GeV.Comment: 5 pages, 1 eps figure, table added, new references added, in print in
Phys. Rev. Let
The Q^2-Dependence of Nuclear Transparency for Exclusive Production
Exclusive coherent and incoherent electroproduction of the meson
from H and N targets has been studied at the HERMES experiment as a
function of coherence length (), corresponding to the lifetime of hadronic
fluctuations of the virtual photon, and squared four-momentum of the virtual
photon (). The ratio of N to H cross sections per nucleon,
known as nuclear transparency, was found to increase (decrease) with increasing
coherence length for coherent (incoherent) electroproduction. For
fixed coherence length, a rise of nuclear transparency with is observed
for both coherent and incoherent production, which is in agreement
with theoretical calculations of color transparency.Comment: 5 pages, 4 figure
The -dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron
The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution
to the magnetic moment of the target nucleus with an energy-weighted integral
of the difference of the helicity-dependent photoabsorption cross sections. The
data collected by HERMES with a deuterium target are presented together with a
re-analysis of previous measurements on the proton. This provides a measurement
of the generalised GDH integral covering simultaneously the nucleon-resonance
and the deep inelastic scattering regions. The contribution of the
nucleon-resonance region is seen to decrease rapidly with increasing . The
DIS contribution is sizeable over the full measured range, even down to the
lowest measured . As expected, at higher the data are found to be in
agreement with previous measurements of the first moment of . From data on
the deuteron and proton, the GDH integral for the neutron has been derived and
the proton--neutron difference evaluated. This difference is found to satisfy
the fundamental Bjorken sum rule at GeV.Comment: 12 pages, 10 figure
Single-spin Azimuthal Asymmetries in Electroproduction of Neutral Pions in Semi-inclusive Deep-inelastic Scattering
A single-spin asymmetry in the azimuthal distribution of neutral pions
relative to the lepton scattering plane has been measured for the first time in
deep-inelastic scattering of positrons off longitudinally polarized protons.
The analysing power in the sin(phi) moment of the cross section is 0.019 +/-
0.007(stat.) +/- 0.003(syst.). This result is compared to single-spin
asymmetries for charged pion production measured in the same kinematic range.
The pi^0 asymmetry is of the same size as the pi^+ asymmetry and shows a
similar dependence on the relevant kinematic variables. The asymmetry is
described by a phenomenological calculation based on a fragmentation function
that represents sensitivity to the transverse polarization of the struck quark.Comment: 4 pages, 1 figure, replaced to correct eprint author field, 2nd
replacement to correct figure; upper limit of model predictions are
corrected. No correction to data or conclusion
Granulomatous Lymphocytic Interstitial Lung Disease (GLILD) in Common Variable Immunodeficiency (CVID): A Multicenter Retrospective Study of Patients From Italian PID Referral Centers
Background: Granulomatous and Lymphocytic Interstitial Lung Diseases (GLILD) is a severe non-infectious complication of Common Variable Immunodeficiency (CVID), often associated with extrapulmonary involvement. Due to a poorly understood pathogenesis, GLILD diagnosis and management criteria still lack consensus. Accordingly, it is a relevant cause of long-term loss of respiratory function and is closely associated with a markedly reduced survival. The aim of this study was to describe clinical, immunological, laboratory and functional features of GLILD, whose combination in a predictive model might allow a timely diagnosis. Methods: In a multicenter retrospective cross-sectional study we enrolled 73 CVID patients with radiologic features of interstitial lung disease (ILD) associated to CVID (CVID-ILD) and 125 CVID patients without ILD (controls). Of the 73 CVID-ILD patients, 47 received a definite GLILD diagnosis while 26 received a clinical-radiologic diagnosis of CVID related ILD defined as uILD. Results: In GLILD group we found a higher prevalence of splenomegaly (84.8 vs. 39.2%), autoimmune cytopenia (59.6 vs. 6.4%) and bronchiectasis (72.3 vs. 28%), and lower IgA and IgG serum levels at CVID diagnosis. GLILD patients presented lower percentage of switched-memory B cells and marginal zone B cells, and a marked increase in the percentage of circulating CD21lo B cells (14.2 vs. 2.9%). GLILD patients also showed lower total lung capacity (TLC 87.5 vs. 5.0%) and gas transfer (DLCO 61.5 vs. 5.0%) percent of predicted. By univariate logistic regression analysis, we found IgG and IgA levels at CVID diagnosis, presence of splenomegaly and autoimmune cytopenia, CD21lo B cells percentage, TLC and DCLO percent of predicted to be associated to GLILD. The joint analysis of four variables (CD21lo B cells percentage, autoimmune cytopenia, splenomegaly and DLCO percent of predicted), together in a multiple logistic regression model, yielded an area under the ROC curve (AUC) of 0.98 (95% CI: 0.95-1.0). The AUC was only slightly modified when pooling together GLILD and uILD patients (0.92, 95% CI: 0.87-0.97). Conclusions: we propose the combination of two clinical parameters (splenomegaly and autoimmune cytopenia), one lung function index (DLCO%) and one immunologic variable (CD21lo%) as a promising tool for early identification of CVID patients with interstitial lung disease, limiting the use of aggressive diagnostic procedures
Exclusive Leptoproduction of rho^0 Mesons from Hydrogen at Intermediate Virtual Photon Energies
Measurements of the cross section for exclusive virtual-photoproduction of
rho^0 mesons from hydrogen are reported. The data were collected by the HERMES
experiment using 27.5 GeV positrons incident on a hydrogen gas target in the
HERA storage ring. The invariant mass W of the photon-nucleon system ranges
from 4.0 to 6.0 GeV, while the negative squared four-momentum Q^2 of the
virtual photon varies from 0.7 to 5.0 GeV^2. The present data together with
most of the previous data at W > 4 GeV are well described by a model that
infers the W-dependence of the cross section from the dependence on the Bjorken
scaling variable x of the unpolarized structure function for deep-inelastic
scattering. In addition, a model calculation based on Off-Forward Parton
Distributions gives a fairly good account of the longitudinal component of the
rho^0 production cross section for Q^2 > 2 GeV^2.Comment: 10 pages, 6 embedded figures, LaTeX for SVJour(epj) document class.
Revisions: curves added to Fig. 1, several clarifications added to tex
Double-Spin Asymmetry in the Cross Section for Exclusive rho^0 Production in Lepton-Proton Scattering
Evidence for a positive longitudinal double-spin asymmetry = 0.24
+-0.11 (stat) +-0.02 (syst) in the cross section for exclusive diffractive
rho^0(770) vector meson production in polarised lepton-proton scattering was
observed by the HERMES experiment. The longitudinally polarised 27.56 GeV HERA
positron beam was scattered off a longitudinally polarised pure hydrogen gas
target. The average invariant mass of the photon-proton system has a value of
= 4.9 GeV, while the average negative squared four-momentum of the virtual
photon is = 1.7 GeV^2. The ratio of the present result to the
corresponding spin asymmetry in inclusive deep-inelastic scattering is in
agreement with an early theoretical prediction based on the generalised vector
meson dominance model.Comment: 10 pages, 4 embedded figures, LaTe
Measurement of single-spin azimuthal asymmetries in semi-inclusive electroproduction of pions and kaons on a longitudinally polarised deuterium target
Single-spin asymmetries have been measured for semi-inclusive
electroproduction of , , and mesons in
deep-inelastic scattering off a longitudinally polarised deuterium target. The
asymmetries appear in the distribution of the hadrons in the azimuthal angle
around the virtual photon direction, relative to the lepton scattering
plane. The corresponding analysing powers in the moment of the
cross section are for ,
for ,
for and for . The moments are
compatible with zero for all particles.Comment: Revised version shortened 9 pages, 3 tables, 7 figure
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