1,037 research outputs found
The biotic adversities of poplar in Italy: a reasoned analysis of factors determining the current state and future perspectives
Poplar cultivation in Italy since its early stages has been conditioned and orientated by biotic and abiotic adversities. Spontaneous hybrids between European black poplar (Populus nigra L.) and Eastern cottonwood (Populous deltoides W. Bartram (Marshall)) were empirically introduced into cultivation for their suitable characters of branchiness, rooting and tolerance to root rots; nevertheless, the first true scientific programme of genetic improvement began after leaf and shoot blight epidemics from Venturia populina during the second and third decades of the twentieth century. The resulting selection of resistant ‘I-214’ clone fostered poplar cultivation in Italy, but at the same time «crystallised» it in a condition of delay with respect to other European countries. With the arrival of leaf spot disease from Marssonina brunnea in the Sixties, phytoiatric treatments were introduced rather than diversifying with more resistant genotypes. Similarly, the increased virulence of leaf rusts from Melampsora spp. starting from about twenty years later, did not succeed in undermining the near monopolisation of ‘I-214’. At present, Marssonina leaf spot and leaf rusts are the most incident diseases: fungicide treatments are carried out mainly on the plantation against the former and mainly in the nursery against the latter. The woolly aphid (Phloeomyzus passerinii) is the most constant and incident pest in plantations. Besides, persisting problems are associated with new pests mainly of exotic origin, especially with the brown marmorated stink bug (Halyomorpha halys).Experiences in other important European poplar cultivation systems highlight the suitability of genetic control, together with a diversification of planted material and efficient agronomic practices. It is advisable to undertake research programmes for vertical and horizontal or quantitative (QTL) resistances, recurring to molecular markers, associated with studies on epigenetics and on microbial communities of various tissues through the new approach offered by metagenomics. The complexity of poplar agrosystems should be increased promoting a homeostatic control of pathogens and pests through antibiotic or competitive features triggered by other microbiota components
Relaxation due to random collisions with a many-qudit environment
We analyze the dynamics of a system qudit of dimension mu sequentially
interacting with the nu-dimensional qudits of a chain playing the ore of an
environment. Each pairwise collision has been modeled as a random unitary
transformation. The relaxation to equilibrium of the purity of the system
qudit, averaged over random collisions, is analytically computed by means of a
Markov chain approach. In particular, we show that the steady state is the one
corresponding to the steady state for random collisions with a single
environment qudit of effective dimension nu_e=nu*mu. Finally, we numerically
investigate aspects of the entanglement dynamics for qubits (mu=nu=2) and show
that random unitary collisions can create multipartite entanglement between the
system qudit and the qudits of the chain.Comment: 7 pages, 6 figure
EXPERIENCES OF AUTOMATED CARTOGRAPHIC GENERALIZATION IN ITALY: TECHNIQUES AND RESULTS OF THE CARGEN PROJECT
La generalizzazione automatica è un campo di ricerca attivo da ormai oltre trenta anni.
Recentemente il costante progresso delle tecniche e il miglioramento dei risultati ha portato
all'introduzione di procedure di derivazione automatica all'interno dei processi produttivi
di alcuni enti cartografici europei.
Questo articolo illustra lo stato della ricerca nel campo della generalizzazione cartografica
automatica in Italia e mostra come anche nel nostro paese si stiano conseguendo risultati
significativi; in particolare verranno descritti i progressi del progetto CARGEN, che studia
la derivazione alla scala 1:25000 e 1:50000 del DBT nazionale.The achievements in the field of automated cartographic generalization have recently
lead to the actual deployment of automatic processes in the production workflow of
some European NMAs.
This article describes the state of the research on automated cartographic generalization
in Italy, focusing in particular on the results of the CARGEN project, studying
the generalization of the National DBT to the 1:25000 and 1:50000 scales
Possible predicative role of electrical risk score on transcatheter aortic valve replacement outcomes in older patients. preliminary data
Background:Transcatheter aortic valve replacement (TAVR) is an effective procedure capable to change the natural history of the degenerative aortic valve stenosis. Despite the TAVR, the patients with advanced valve disease and severe myocardial damage (low flow, gradient and ejection fraction)show high mortality level. Aim of this study was toevaluate the predicative power of a noninvasive and inexpensive test obtained by means of a simple standard 12-leads electrocardiogram,known as the Electrical Risk Score (ERS).
Methods: ERS was composed by seven simple ECG markers: heart rate (>75 bpm); QRS duration (>110 ms), left ventricular hypertrophy (Sokolow-Lyon criteria), delayed QRS transition zone (≥ V4), frontal QRS-T angle (>90°), long QTBazett (>450 ms for men and >460 in women) or JTBazett(330 ms for men and > 340 ms for women);long T peak to T end interval (Tp-e)( >89 ms). An ERS ≥ 4was considered high risk for all-cause or cardiovascular mortality.We calculated retrospectively the pre-procedure ERS in 40 TAVR patients after one year of follow-up.
Results: In the follow up the all-cause and cardiovascular mortality were respectively 25% and 15%.None of survivors reported ERS ≥ 4,moreover, the ERS was the strongest predictor of all-cause (odd ratio 3.73, 95% CI: 1.44-9.66, p<0.05) or cardiovascular (odd ratio 3.95, 95% CI: 1.09-14.27, p<0.05) mortality.ROC curves showed that ERS had the widest significant sensitivity-specificity area under the curve (auc) predicting all-cause (auc: 0.855, p<0.05) or cardiovascular mortality (auc: 0.908, p<0.05).
Conclusions:In this pivotal study, ERS resulted an useful tool to stratify the risk of mortality in one-year follow-up TAVR patients. Obviously, it is necessary to confirm these data in large prospective studies
Genetic, Epigenetic and Molecular Changes in Melanoma: A New Paradigm for Biological Classification
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