17,463 research outputs found
Structural properties and quasiparticule energies of cubic SrO, MgO and SrTiO3
The structural properties and the band structures of the charge-transfer
insulating oxides SrO, MgO and SrTiO3 are computed both within density
functional theory in the local density approximation (LDA) and in the Hedin's
GW scheme for self-energy corrections, by using a model dielectric function,
which approximately includes local field and dynamical effects. The deep
valence states are shifted by the GW method to higher binding energies, in very
good agreement with photoemission spectra. Since in all of these oxides the
direct gaps at high-symmetry points of the Brillouin zone may be very sensitive
to the actual value of the lattice parameter a, already at the LDA level,
self-energy corrections are computed both at the theoretical and the
experimental a. For MgO and SrO, the values of the transition energies between
the valence and the conduction bands are improved by GW corrections, while for
SrTiO3 they are overestimated. The results are discussed in relation to the
importance of local field effects and to the nature of the electronic states in
these insulating oxides.Comment: 3 figures, accepted in J. Phys.: Condens. Matte
Synthesis of finite displacements and displacements in continental margins
The scope of the project is the analysis of displacement-rate fields in the transitional regions between cratonal and oceanic lithospheres over Phanerozoic time (last 700 ma). Associated goals are an improved understanding of range of widths of major displacement zones; the partition of displacement gradients and rotations with position and depth in such zones; the temporal characteristics of such zones-the steadiness, episodicity, and duration of uniform versus nonunifrom fields; and the mechanisms and controls of the establishment and kinematics of displacement zones. The objective is to provide a context of time-averaged kinematics of displacement zones. The initial phase is divided topically among the methodology of measurement and reduction of displacements in the lithosphere and the preliminary analysis from geologic and other data of actual displacement histories from the Cordillera, Appalachians, and southern North America
Real decoupling ghost quantization of the CGHS model for two dimensional black holes
A complete RST quantization of a CGHS model plus Strominger term is carried
out. In so doing a conformal invariant theory with is
found, that is, without ghosts contribution. The physical consequences of the
model are analysed and positive definite Hawking radiation is found.Comment: 14 pages, latex, no figures, marginal errors correcte
Preliminary genetic variability analysis of the native Garfagnina goats based on microsatellite polymorphism
For the development of an appropriate programme for conservation of animal genetic resources, genetic typifying is considered an important preliminary step. In this paper, we have done a preliminary genetic variability analysis of 48 adult Garfagnina goats belonging to a single flock of Tuscany using 12 STR markers (MAF065, SRCRSP05, INRA023, McM527, CSRD247, SRCRSP23, OarFCB20, TGLA53, INRA005, INRA063, ETH10, ILSTS87) some of which belonged to a markers panel validated by the International Society of Animal Genetics (ISAG) and others routinely used by the facilities of the Laboratorio di Genetica e Servizi (Associazione Italiana Allevatori, Migliaro, Italy). Garfagnina is an Italian native goat breed registered on the Tuscan regional repertory of genetic resources at risk of extinction and have a total of about 745 animals belonging to 17 flocks. Garfagnina breed is important for livestock biodiversity preservation, being a key animal for specialized cheese market in the Tuscan region. For each marker the following parameters were computed: number of alleles, effective allele size, observed heterozygosity and polymorphism information content (PIC). Allelic frequencies were estimated by direct counting. To analyze the genetic variability of the population, the following parameters were computed at population level: molecular co-ancestry coefficients (fij), kinship distance (Dk), and inbreeding coefficient (Fi). Moreover, genetic similarities (GS) among all animals were investigated using the Individual Multilocus Genotype. The number of alleles ranged from 3 to 9 (mean 5.92) whereas the expected heterozygosity ranged from 0.48 to 0.83 (mean 0.69). There was a high genetic similarity within the whole population (0.43) showing the great homogeneity of the sampled animals, as confirmed also by the small kinship distance (0.34). However inbreeding coefficient was low (0.32). The results of this research indicate that, despite the fact that animals are considered to belong to the same breeding, the genetic variability of this Garfagnina goat population is acceptable for a population with a reduced numerical value
Deterministic single-photon source from a single ion
We realize a deterministic single-photon source from one and the same calcium
ion interacting with a high-finesse optical cavity. Photons are created in the
cavity with efficiency (88 +- 17)%, a tenfold improvement over previous
cavity-ion sources. Results of the second-order correlation function are
presented, demonstrating a high suppression of two-photon events limited only
by background counts. The cavity photon pulse shape is obtained, with good
agreement between experiment and simulation. Moreover, theoretical analysis of
the temporal evolution of the atomic populations provides relevant information
about the dynamics of the process and opens the way to future investigations of
a coherent atom-photon interface
Detection of bovine papillomavirus type 2 in the peripheral blood of cattle with urinary bladder tumours: possible biological role
Bovine papillomavirus type 2 (BPV-2) infection has been associated with urinary bladder tumours in adult cattle grazing on bracken fern-infested land. In this study, we investigated the
simultaneous presence of BPV-2 in whole blood and urinary bladder tumours of adult cattle in an attempt to better understand the biological role of circulating BPV-2. Peripheral blood samples were collected from 78 cattle clinically suffering from a severe chronic enzootic haematuria. Circulating BPV-2 DNA was detected in 61 of them and in two blood samples from healthy cows. Fifty of the affected animals were slaughtered at public slaughterhouses and neoplastic proliferations in the urinary bladder were detected in all of them. BPV-2 DNA was amplified and sequenced in 78% of urinary bladder tumour samples and in 38.9% of normal samples as a control. Circulating episomal BPV-2 DNA was detected in 78.2% of the blood samples. Simultaneous presence of BPV-2 DNA in neoplastic bladder and blood samples was detected in 37 animals. Specific viral E5 mRNA and E5 oncoprotein were also detected in blood by RT-PCR
and Western blot/immunocytochemistry, respectively. It is likely that BPV-2 can persist and be maintained in an active status in the bloodstream, in particular in the lymphocytes, as a reservoir of viral infection that, in the presence of co-carcinogens, may cause the development of urinary bladder tumours
Microwave-induced thermal escape in Josephson junctions
We investigate, by experiments and numerical simulations, thermal activation
processes of Josephson tunnel junctions in the presence of microwave radiation.
When the applied signal resonates with the Josephson plasma frequency
oscillations, the switching current may become multi-valued in a temperature
range far exceeding the classical to quantum crossover temperature. Plots of
the switching currents traced as a function of the applied signal frequency
show very good agreement with the functional forms expected from Josephson
plasma frequency dependencies on the bias current. Throughout, numerical
simulations of the corresponding thermally driven classical Josephson junction
model show very good agreement with the experimental data.Comment: 10 pages and 4 figure
Changing Personal Values through Value-Manipulation Tasks: A Systematic Literature Review Based on Schwartz’s Theory of Basic Human Values
According to the Theory of Basic Human Values, values are relatively stable, but not immutable, abstract goals which strongly influence peoples' lives. Since their relative stability, psychosocial research is attempting to understand the extent to which it is possible to induce a voluntary change in people's personal values. The main aim of this study was to systematically review the existing literature on experiments to induce a value change, also highlighting the theoretical perspectives used to develop the experimental tasks. We conducted a literature search of five databases (SCOPUS, ProQuest, PsycINFO, PubMed, and Web of Science). After the screening and the eligibility phase, we included a total of 14 articles (25 experiments). Most of these studies involved university students and adopted a pre-and post-test design, using different manipulation tasks. The results highlighted the possibility of inducing a voluntary value change, assessed in terms of mean levels and/or rank order. These findings provide new insights regarding the stability of values in the light of the Theory of Basic Human Values. The practical implications and future research directions are discussed
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