Neutrino oscillation studies and the neutrino cross section

The present uncertainties in the knowledge of the neutrino cross sections for E_nu \sim 1 GeV, that is in the energy range most important for atmospheric and long baseline accelerator neutrinos, are large. These uncertainties do not play a significant role in the interpretation of existing data, however they could become a limiting factor in future studies that aim at a complete and accurate determination of the neutrino oscillation parameters. New data and theoretical understanding on nuclear effects and on the electromagnetic structure functions at low Q^2 and in the resonance production region are available, and can be valuable in reducing the present systematic uncertainties. The collaboration of physicists working in different subfields will be important to obtain the most from this available information. It is now also possible, with the facilities developed for long baseline beams, to produce high intensity and well controlled neutrino beams to measure the neutrino interaction properties with much better precision that what was done in the past. Several projects and ideas to fully exploit these possibilities are under active investigation. These topics have been the object of the first neutrino interaction (NUINT01) workshop.Comment: Summary talk at the 1st workshop on neutrino-nucleus interactions in the few GeV region (NuInt01), Tsukuba, Japan, 13-16 Dec 2001. 14 pages, 7 figure

First-principles prediction of structure, energetics, formation enthalpy, elastic constants, polarization, and piezoelectric constants of AlN, GaN, and InN: comparison of local and gradient-corrected density-functional theory

A number of diverse bulk properties of the zincblende and wurtzite III-V nitrides AlN, GaN, and InN, are predicted from first principles within density functional theory using the plane-wave ultrasoft pseudopotential method, within both the LDA (local density) and GGA (generalized gradient) approximations to the exchange-correlation functional. Besides structure and cohesion, we study formation enthalpies (a key ingredient in predicting defect solubilities and surface stability), spontaneous polarizations and piezoelectric constants (central parameters for nanostructure modeling), and elastic constants. Our study bears out the relative merits of the two density functional approaches in describing diverse properties of the III-V nitrides (and of the parent species N$_2$, Al, Ga, and In), and leads us to conclude that the GGA approximation, associated with high-accuracy techniques such as multiprojector ultrasoft pseudopotentials or modern all-electron methods, is to be preferred in the study of III-V nitrides.Comment: RevTeX 6 pages, 12 tables, 0 figure

Investigation of antibacterial activity of new classes of essential oils derivatives

Essential oils (EOs) have deserved much attention in the past decades for their antimicrobial activity, since many of them have demonstrated efficacy against food-borne pathogenic and spoilage microorganisms. Moreover, they have potential application in animal nutrition as multifunctional feed supplements, avoiding or diminishing the use of antibiotics in livestock. However, low solubility and bioavailability as well as volatility and marked aromatic note are important limitations in food and feed applications. In this study we present the synthesis, characterization and evaluation of the antibacterial activity of new thymol, carvacrol and menthol derivatives. The new compounds have been designed to overcome the limitations of the precursors, such as poor water solubility and volatility, still maintaining a good antimicrobial profile. We evaluated the activity of the synthetized compounds against pathogens causing important foodborne diseases, . i.e. . Clostridium perfringens, . Salmonella typhimurium, . Salmonella enteritidis and . Escherichia coli. The low MICs and MBCs values for some of the studied compounds, combined with water solubility and negligible cytotoxicity towards HT-29 human cells, confirmed the potential use for EOs derivatives in the food industry

Roughening of close-packed singular surfaces

An upper bound to the roughening temperature of a close-packed singular surface, fcc Al (111), is obtained via free energy calculations based on thermodynamic integration using the embedded-atom interaction model. Roughening of Al (111) is predicted to occur at around 890 K, well below bulk melting (933 K), and it should therefore be observable, save for possible kinetic hindering.Comment: RevTeX 4 pages, embedded figure

Island nucleation in the presence of step edge barriers: Theory and applications

We develop a theory of nucleation on top of two-dimensional islands bordered by steps with an additional energy barrier $\Delta E_S$ for descending atoms. The theory is based on the concept of the residence time of an adatom on the island,and yields an expression for the nucleation rate which becomes exact in the limit of strong step edge barriers. This expression differs qualitatively and quantitatively from that obtained using the conventional rate equation approach to nucleation [J. Tersoff et al., Phys. Rev. Lett.72, 266 (1994)]. We argue that rate equation theory fails because nucleation is dominated by the rare instances when two atoms are present on the island simultaneously. The theory is applied to two distinct problems: The onset of second layer nucleation in submonolayer growth, and the distribution of the sizes of top terraces of multilayer mounds under conditions of strong step edge barriers. Application to homoepitaxial growth on Pt(111) yields the estimate $\Delta E_S \geq 0.33$ eV for the additional energy barrier at CO-decorated steps.Comment: 13 pages, 3 figure

Effects of macroscopic polarization in III-V nitride multi-quantum-wells

Huge built-in electric fields have been predicted to exist in wurtzite III-V nitrides thin films and multilayers. Such fields originate from heterointerface discontinuities of the macroscopic bulk polarization of the nitrides. Here we discuss the background theory, the role of spontaneous polarization in this context, and the practical implications of built-in polarization fields in nitride nanostructures. To support our arguments, we present detailed self-consistent tight-binding simulations of typical nitride QW structures in which polarization effects are dominant.Comment: 11 pages, 9 figures, uses revtex/epsf. submitted to PR

Men and wolves: Anthropogenic causes are an important driver of wolf mortality in human-dominated landscapes in Italy

Over the last 40 years the gray wolf (Canis lupus) re-colonized its historical range in Italy increasing human-predator interactions. However, temporal and spatial trends in wolf mortality, including direct and indirect persecution, were never summarized. This study aims to fill this gap by focusing on the situation of Tuscany and Emilia-Romagna regions, hosting a significant proportion of the Italian wolf population, by: (i) identifying the prevalent causes of wolf mortality, (ii) summarizing their temporal and spatial patterns and (iii) applying spatially-explicit Generalized Linear Models to predict wolf persecution. Between October 2005 and February 2021, 212 wolf carcasses were collected and subjected to necropsy, being involved in collisions with vehicles (n = 104), poisoned (n = 45), wounded with gunshot (n = 24) or blunt objects (n = 4) and being hanged (n = 2). The proportion of illegally killed wolves did not increase through time. Most persecution events occurred between October and February. None of our candidate models outperformed a null model and covariates such as the density of sheep farms, number of predations on livestock, or human density were never associated to the probability of having illegally killed wolves, at the municipal scale. Our findings show that conventional correlates of wolf persecution, combined with a supposedly high proportion of non-retrieved carcasses, fail to predict illegal wolf killings in areas where the species have become ubiquitous. The widespread spatial distribution of illegal killings indicates that persecution probably arises from multiple kinds of conflicts with humans, beyond those with husbandry. Wolf conservation in Italy should thus address cryptic wolf killings with multi-disciplinary approaches, such as shared national protocols, socioecological studies, the support of experts’ experience and effective sampling schemes for the detection of carcasses

Status of the LUNA experiment

Luna is a pilot project initially focused on the 3He(3He, 2p)4He cross section measurement within the thermal energy region of the Sun (15–27 keV). A compact high current 50 kV ion accelerator facility including a windowless gas target system, a beam calorimeter and four detector telescopes has been built, tested and installed underground at Laboratori Nazionali del Gran Sasso. In these conditions, thanks to the cosmic ray suppression, we could attain a background level of less than 1 event per week, a rate similar to the one expected from 3He(3He, 2p)4He at the lower edge of the Sun thermal energy region

Endothelial Cells Obtained from Patients Affected by Chronic Venous Disease Exhibit a Pro-Inflammatory Phenotype

The inflammatory properties of vein endothelium in relation to chronic venous disease (CVD) have been poorly investigated. Therefore, new insights on the characteristics of large vein endothelium would increase our knowledge of large vessel physiopathology. METHODOLOGY/PRINCIPAL FINDINGS: Surgical specimens of veins were obtained from the tertiary venous network (R3) and/or saphenous vein (SF) of patients affected by CVD and from control individuals. Highly purified venous endothelial cell (VEC) cultures obtained from CVD patients were characterized for morphological, phenotypic and functional properties compared to control VEC. An increase of CD31/PECAM-1, CD146 and ICAM-1 surface levels was documented at flow cytometry in pathological VEC with respect to normal controls. Of note, the strongest expression of these pro-inflammatory markers was observed in VEC obtained from patients with more advanced disease. Similarly, spontaneous cell proliferation and resistance to starvation was higher in pathological than in normal VEC, while the migratory response of VEC showed an opposite trend, being significantly lower in VEC obtained from pathological specimens. In addition, in keeping with a higher baseline transcriptional activity of NF-kB, the release of the pro-inflammatory cytokines osteoprotegerin (OPG) and vascular endothelial growth factor (VEGF) was higher in pathological VEC cultures with respect to control VEC. Interestingly, there was a systemic correlation to these in vitro data, as demonstrated by higher serum OPG and VEGF levels in CVD patients with respect to normal healthy controls. CONCLUSION/SIGNIFICANCE: Taken together, these data indicate that large vein endothelial cells obtained from CVD patients exhibit a pro-inflammatory phenotype, which might significantly contribute to systemic inflammation in CVD patients