156 research outputs found
How to compute one-loop Feynman diagrams in lattice QCD with Wilson fermions
We describe an algebraic algorithm which allows to express every one-loop
lattice integral with gluon or Wilson-fermion propagators in terms of a small
number of basic constants which can be computed with arbitrary high precision.
Although the presentation is restricted to four dimensions the technique can be
generalized to every space dimension. We also give a method to express the
lattice free propagator for Wilson fermions in coordinate space as a linear
function of its values in eight points near the origin. This is an essential
step in order to apply the recent methods of L\" uscher and Weisz to
higher-loop integrals with fermions.Comment: Talk presented at LATTICE96(theoretical developments) Postscript file
avalaible at http://www1.le.infn.it:8080/~caraccio/TCMS.htm
Lattice energy-momentum tensor with Symanzik improved actions
We define the energy-momentum tensor on lattice for the and
for the nonlinear -model Symanzik tree-improved actions, using Ward
identities or an explicit matching procedure. The resulting operators give the
correct one loop scale anomaly, and in the case of the sigma model they can
have applications in Monte Carlo simulations.Comment: Self extracting archive fil
Drinking wine at home: Hedonic analysis of sicilian wines using quantile regression
Abstract: In recent decades, the Sicilian wine industry has experienced a booming expansion because of the growing preferences of Italian consumers for Sicilian wines, especially in extra-regional markets. These consumers have been paying closer attention to Sicilian premium wines.
For this reason, the objective of this study is to inform professional investors and wine managers about the consumer preferences with respect to the most important segment categories of domestically consumed Sicilian wines. Using the quantile regression technique, we analyzed the
role of wine attributes and prices as an information tool in order to value for each wine segment the implicit price of the attributes affecting wine consumers\u2019 choices. The results indicate that Protected Designation of Origin (PDO) and Geographical Indication (PGI) certification is the main determinant in the wine price mechanisms and certified wines achieve premium prices that are progressively higher as the price level of the wine increases. Furthermore the effect of the brand on price formation seems to have a significant impact for low-end wines, whereas it has no specific impact on the price mechanism for high-end wines.
Keywords: Consumer Scan Dataset, Geographic Origin, Hedonic Price, Robust Regression, Wine Consumptio
Picking out a wine: Consumer motivation behind different quality wines choice
The quality scale of Italian wines is mainly organized in four categories: PDO, PGI, basic and bulk wine. Our analysis explicitly investigates the patterns and determinants of consumption for these four different types of wine by analyzing a representative sample of consumers from a traditional wine-producing country. This study provides for first time insights on quality perceptions of wines and verifies whether Italian consumers perceive significant differences among the different categories of wines. The overall results, obtained through a system of equation estimates, show that consumer motivations and wine consumption determinants change according to each different range of wine quality and thereby support a hierarchical scale of quality wines, as a fact consumers' motivation progressively changes as the quality scales of the wine increase or decrease. In addition, this study highlights for first time any differences in the consumption determinants between the PDO and the PGI wines in a national context and it suggests that the influence of the two different GI labels on the wine choice of consumers is truly different. Important insights were also provided for bulk wine whose consumption seems to be closely related to wine tourism and the desire to buy locally produced wines. Keywords: Basic wines, Bulk wines, Local wines, PDO, PG
Probing the role of nuclear-envelope invaginations in the nuclear-entry route of lipofected DNA by multi-channel 3D confocal microscopy.
Nuclear breakdown was found to be the dominant route for DNA entry into the nucleus in actively dividing cells. The possibility that alternative routes contribute to DNA entry into the nucleus, however, cannot be ruled out. Here we address the process of lipofection by monitoring the localization of fluorescently-labelled DNA plasmids at the single-cell level by confocal imaging in living interphase cells. As test formulation we choose the cationic 3β-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic helper lipid dioleoylphosphatidylethanolamine (DOPE) with plasmidic DNA pre-condensed by means of protamine. By exploiting the spectral shift of the fluorescent dye FM4-64 (N-(3-triethylammoniumpropyl)-4-(p-diethylaminophenylhexatrienyl)-pyridinium 2Br) we monitor the position of the nuclear envelope (NE), while concomitantly imaging the whole nucleus (by Hoechst) and the DNA (by Cy3 fluorophore) in a multi-channel 3D confocal imaging experiment. Reported results show that DNA clusters are typically associated with the NE membrane in the form of tubular invaginations spanning the nuclear environment, but not completely trapped within the NE invaginations, i.e. the DNA may use these NE regions as entry-points towards the nucleus. These observations pave the way to investigating the molecular details of the postulated processes for a better exploitation of gene-delivery vectors, particularly for applications in non-dividing cells
Influence of Genetics and Gender in Takotsubo Syndrome: Unexplored Areas of an Incompletely Understood Disease
Stress cardiomyopathy, also known as "Takotsubo syndrome" (TS), is a complex disease that typically affects postmenopausal women. The pathophysiology is still largely unknown, but evidence of a frequent association between TS and stressful events has evoked the hypothesis of a pathophysiologic role of sympathetic overdrive in the myocardial dysfunction. However, despite several studies, the role gender plays in TS onset remains unclear because stress cardiomyopathy also has been described in young women and in men. Moreover, although several cases of a familial cluster of TS have been reported, no responsible gene mutations or polymorphisms have been clearly identified so far, and neither the modality of transmission or the true impact of genetic background. In this review, we discuss the role of gender in the onset, course, and outcomes of TS and we report the available data about polymorphisms and gene mutations so far investigated, trying to critically analyze the evidence reported in the literature
Physical exercise and Sport activities in patients with and without coronary heart disease
Background: The quantity and intensity of physical activity required for the primary prevention of coronary heart disease remain unclear. Therefore, we examined the association between physical activity and coronary risk. Methods: We studied 100 patients with chest pain, 78 men and 22 women, not older than 65 years, admitted to a coronary care unit. Patients were subdivided in 3 groups: the first group included patients with acute myocardial infarction, the second group included patients with chronic heart disease, the third included patients with non-ischemic chest-pain. A questionnaire on daily physical activity was filled by each patient. Results: A significantly higher percentage of patients with myocardial infarction and coronary heart disease had a sedentary life style compared to patients of the third group. Compared with subjects without heart disease, a significantly higher percentage of patients of the first and second group covered a daily average distance shorter than 500 meters, while a significantly inferior percentage covered a distance longer than 1 Km every day. A significantly lower percentage of patients with coronary heart disease practised sport compared with the third group. At the time of hospitalization a very small percentage of coronary heart disease patients still practised sport. Conclusions: The association between physical activity and reduced coronary risk is clear; in order to obtain benefits it is sufficient just walking every day. Regarding physical activity, continuity is important: patients, who practised sport only in juvenile age, breaking off when older, may lose the obtained advantages
Determinants of Sicilian Wine Consumption: Evidence from a Binary Response Model
The growing importance of Sicilian wines in the Italian market provides the context in which this paper is set. This study presents the results of a recent survey on Sicilian wine consumption in Italy. By means of a binary response model, this paper evaluates the main determinants (demographic profile, preference and attitudes) that influence Italian consumers' preferences for Sicilian wines. The estimates, based on the stated preference of 953 Italian wine consumers, emphasize that income and habits to purchase at wine shops and the habit to drink between meals significantly influence the willingness to consume Sicilian wines. Furthermore the sample propensity to consume the Sicilian wine increases for white wines and when the consumption takes placed in public spaces
Petrological characterization of the Triassic red beds of the Tabular Cover of the Iberian Meseta (Alcaraz area)
Las capas rojas triásicas de la Cobertera Tabular de la Meseta Ibérica
consisten en cuerpos de arenisca de origen fluvial embebidos en sedimentos
finos. Los cuerpos estudiados pertenecen a dos de las cuatro secuencias
de la sucesión estratigráfica y se formaron en ambientes sedimentarios diferentes,
como son: (i) depósitos de desbordamiento y depósitos canalizados
(secuencia II) y (ii) llanura fluvial de tipo trenzado (secuencia IV). El estudio
petrológico ha revelado que existen diferencias entre ellos en cuanto a la
composición modal del esqueleto, la textura sedimentaria y los procesos diagenéticos
ocurridos. La señal composicional revela una disminución del contenido
en plagioclasa, que se corresponde con un aumento del contenido en
fragmentos de rocas, así como una disminución en la compactación y grado
de cementación de la secuencia II a la IV. La tipología y cronología de los cementos
indica una profundidad de enterramiento coherente con una etapa
mesodiagenética tempThe Triassic Red Beds of the Tabular Cover of the Iberian Meseta consist
on fluvial sandstone bodies embedded in overbank fines. The studied deposits
correspond to two of the four sequences of the stratigraphic succession
and developed under different sedimentary environments as: (i) overbank
and channel deposits (sequence II) and (ii) braidplain deposits (sequence
IV). The petrological study has revealed the main differences between
them as a function of framework composition, textural parameters and diagenetic
processes. Compositional trends highlighted a decrease of plagioclase
content to which correspond major content in rock fragments, as well
as a minor compaction and degree of cementation from sequence II to IV. Cements
types and chronology suggest a depth of burial according to an early
meso-diagenesis stag
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