3,571 research outputs found
Mitochondrial DNA lineages of Italian Giara and Sarcidano horses
Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed
Statistical model of dephasing in mesoscopic devices introduced in the scattering matrix formalism
We propose a phenomenological model of dephasing in mesoscopic transport,
based on the introduction of random phase fluctuations in the computation of
the scattering matrix of the system. A Monte Carlo averaging procedure allows
us to extract electrical and microscopic device properties. We show that, in
this picture, scattering matrix properties enforced by current conservation and
time reversal invariance still hold. In order to assess the validity of the
proposed approach, we present simulations of conductance and magnetoconductance
of Aharonov-Bohm rings that reproduce the behavior observed in experiments, in
particular as far as aspects related to decoherence are concerned.Comment: 6 pages, 6 figure
Superconducting proximity effect in interacting double-dot systems
We study subgap transport from a superconductor through a double quantum dot
with large on-site Coulomb repulsion to two normal leads. Non-local
superconducting correlations in the double dot are induced by the proximity to
the superconducting lead, detectable in non-local Andreev transport that splits
Cooper pairs in locally separated, spin-entangled electrons. We find that the
-- characteristics are strongly asymmetric: for a large bias voltage of
certain polarity, transport is blocked by populating the double dot with states
whose spin symmetry is incompatible with the superconductor. Furthermore, by
tuning gate voltages one has access to splitting of the Andreev excitation
energies, which is visible in the differential conductance.Comment: 5 pages, 4 figure
Effect of dephasing on the current statistics of mesoscopic devices
We investigate the effects of dephasing on the current statistics of
mesoscopic conductors with a recently developed statistical model, focusing in
particular on mesoscopic cavities and Aharonov-Bohm rings. For such devices, we
analyze the influence of an arbitrary degree of decoherence on the cumulants of
the current. We recover known results for the limiting cases of fully coherent
and totally incoherent transport and are able to obtain detailed information on
the intermediate regime of partial coherence for a varying number of open
channels. We show that dephasing affects the average current, shot noise, and
higher order cumulants in a quantitatively and qualitatively similar way, and
that consequently shot noise or higher order cumulants of the current do not
provide information on decoherence additional or complementary to what can be
already obtained from the average current.Comment: 4 pages, 4 figure
Enzymatic upgrade of old paperboard containers
The use of enzymes in secondary fiber (old paperboard containers) upgrading was investigated. The following aspects were analyzed:
(i) the effect of several enzymes and (non-hydrolytic) cellulose-binding domains on the pulp and paper properties; (ii) factors influencing
enzymatic treatment of secondary fiber: enzyme dosage and reaction time; and (iii) enzyme action on fractions with different fiber-length.
In general, all the tested enzymatic preparations were able to improve the pulp drainability. In most cases this improvement was obtained
at the expense of paper strength. The use of cellulose-binding domains allowed for the simultaneous increase in drainability and strength properties
Catching VY Sculptoris in a low state
Context. In the context of a large campaign to determine the system
parameters of high mass transfer cataclysmic variables, we found VY Scl in a
low state in 2008. Aims. Making use of this low state, we study the stellar
components of the binary with little influence of the normally dominating
accretion disc. Methods. Time-resolved spectroscopy and photometry of VY Scl
taken during the low state are presented. We analysed the light-curve and
radial velocity curve and use time-resolved spectroscopy to calculate Doppler
maps of the dominant emission lines. Results. The spectra show narrow emission
lines of Halpha, Hbeta, HeI, NaID, and FeII, as well as faint TiO absorption
bands that trace the motion of the irradiated secondary star, and Halpha and
HeI emission line wings that trace the motion of the white dwarf. From these
radial velocities, we find an orbital period of 3.84 h, and put constraints on
binary parameters such as the mass ratio M2/M1 of 0.43 and the inclination of
15 deg. With a secondary's mass between 0.3 and 0.35 Msol, we derive the mass
for the white dwarf as M1 = 0.6-0.1 Msol.Comment: 8 pages, 9 figures, accepted for publication in A&
Lineamenti morfologici e cartografia dei popolamenti bentonici di Rada della Reale nell'isola dell’Asinara (Sardegna NW)= Morphological elements and cartography of benthic community in Rada della Reale, Asinara Island (Sardinia NW)
A detailed investigation of bottom types in Rada della Reale has been carried out in 1998 as part of resources study of Asinara National Park. The study area, along 23 km of coastline between Punta Barbatossa and Punta Trabucato, has a surface of 15 km2. Detailed informattin on biotic communities in the area has been recorded and transferred in a thematic map together with geomorphological features. The main benthic community is represented by the Posidonia oceanica meadow, wlth a denslty up to 700-800 shootslm2. Other seagrasses like Cymodocea nodosa and Caulerpa prolifera are also present. In the mediolittoral zone assemblages of Patella ferruginea are of main importance.
Considering the great value of the area, in the future an integrated management strategy that improves conservation and enhances the value of the resources must be developed
Cellulose-binding domains as a tool for paper recycling
Treatment of secondary paper fibres with cellulose-binding domains allows for improvements of pulp drainability and of paper mechanical properties. The interfacial system fibrewater- fibre, and after drying, fibre-air-fibre, may be affected by the CBD treatment, influencing the pulp and paper technical properties. Inverse Gas Chromatography provides experimental evidence that support this hypothesis
A review on diversity, conservation and nutrition of wild edible fruits
The United Nations adopted the Millennium Declaration of September 2009 to improve the global living conditions through reducing poverty and hunger. However, considerable numbers of people are still living in utter penury and are deprived of a dignified living. In such tough circumstances nature’s free gift in the form of wild edible foods are benefiting the vulnerable and dependent communities. Wild edible plants (WEPs) are the species those are neither cultivated nor domesticated however are available in their wild natural habitat and used as sources of these plants have played a significant role in the development and civilization of human history throughout the ages and globe. These wild edible plants have played a significant role in supplying food and nutritional requirements of poor communities in many rural parts of the world. These wild edibles can be popularized only when they are comparedfor their nutritional and health benefits with major or widely used cultivated plants. The social, cultural, religious, and belief system of the rural communities are incomplete without these wild edible plants. Domestication of these wild edible plants can increase their use and their conservation as well. The present review paper has described the wild edible plants in context of their diversity, traditional knowledge, conservation practices and nutritional composition from the available secondary literature. Authors feel there is still scope to incorporate more contextual variables for explaining more variations embedded with local people’s perception on values and usage of these wild edible fruits
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