Large phonon-drag enhancement induced by narrow quantum confinement at the LaAlO3/SrTiO3 interface

The thermoelectric power of the two-dimensional electron system (2DES) at the LaAlO3/SrTiO3 interface is explored below room temperature, in comparison with that of Nb-doped SrTiO3 single crystals. For the interface we find a region below T =50 K where thermopower is dominated by phonon-drag, whose amplitude is hugely amplified with respect to the corresponding bulk value, reaching values ~mV/K and above. The phonon-drag enhancement at the interface is traced back to the tight carrier confinement of the 2DES, and represents a sharp signature of strong electron-acoustic phonon coupling at the interface

A custom-built simple system for conditioning and measurement of in situ whole-cluster transpiration

A custom-built, low-cost gas exchange system designed for conditioning of the cluster microclimate and for fully automated measurements of in situ whole-cluster transpiration is presented. Measurements were carried out on potted Sangiovese grapevines at the onset of veraison, To increase the range of variability in cluster transpiration, air streams of different vapor pressure deficits (VPD) were created by conditioning the temperature of the incoming flow. Heating was created and maintained for 10 d (26 June - 5 July) by air flow through a metal segment equipped with three 75 W (warm) or 100 W (hot) light bulbs, The cluster transpiration rates recorded for the unheated (control) clusters throughout the conditioning period varied from 0.18 to 0.28 mmol m-2 s-1. While the daily transpiration rates of clusters supplied with warm air were similar to those of the control, water loss began to decrease significantly in clusters treated with hot air from day 4 onward and stayed lower throughout the remaining conditioning period. The gas exchange system presented here proved sensitive enough to detect the typically low transpiration rates of berries during ripening; effects due to air heating could be separated from fluctuations caused by daily variation of weather.

Molecular characterization of officially registered Sangiovese clones and of other Sangiovese-like biotypes in Tuscany, Corsica and Emilia-Romagna

The present study was designed (1) to identify and determine the origin of the genetic variability via SSR and AFLP within a group of 39 Sangiovese clones officially listed in the National Grapevine Registry, (2) to pinpoint varietal differences and potential family relations among 34 Sangiovese-like biotypes, via the SSR markers. Most biotypes are regarded as Sangiovese but sometimes are known under different names. In both studies the reference standard was the registered Sangiovese clone SG 12T.No polymorphism was found among the officially listed 39 clones analysed at 6 microsatellite loci. This enabled us to confirm their origin from a single mother plant, thereby supporting the view that any morphological or qualitative differences may be the result of propagation-related mutagenic events. A subsequent AFLP analysis of 26 of the 39 clones showed polymorphic bands in three of them (two identical) that may correspond to a mutagenic event. Assays with SSR markers on 34 Sangiovese-like biotypes collected in Tuscany, Corsica and Emilia-Romagna showed that 28 are identical with the reference Sangiovese clone SG 12T, while the remaining 6 (Sangiovese 1, Sangiovese 6, Morellino, Poverina, Sangiovese forte and Brunellone) are genetically different from SG 12T and among one another so that no direct family relations could be established

Involvement of cocaine-amphetamine regulated transcript in the differential feeding responses to nociceptin/orphanin FQ in dark agouti and Wistar Ottawa Karlsburg W rats

Wistar Ottawa Karlsburg W (WOKW) rats and their controls, dark agouti (DA), present different features: in particular, DA rats are lean, while the WOKW are obese and present symptoms of hypertension, dyslipidemia, hyperinsulinemia, and impaired glucose tolerance. The present study tested the hypothesis that these two strains would demonstrate different sensitivity to nociceptin/orphanin FQ (N/OFQ). N/OFQ was injected into the lateral brain ventricle (LBV) of sated DA and WOKW rats, and corticosterone levels in both strains were measured after LBV injection of N/OFQ. LBV N/OFQ injections dose-dependently produced a significant increase in food intake (4 h) in DA rats, but not in WOKW. However, corticosterone levels were increased by N/OFQ to a greater degree in WOKW than in DA rats. Gene sequencing and gene expression of ORL1 receptor and cocaine-amphetamine regulated transcript (Cart) peptide were evaluated to study the difference in N/OFQ-induced feeding behavior in the two strains. WOKW rats had a different amino acid sequence of Cart peptide and a significantly higher expression of Cart in the hypothalamus. The present data show that DA and WOKW rats demonstrate different sensitivity to N/OFQ, and suggest that Cart peptide might be the underlying mechanism of this difference

Giant Oscillating Thermopower at Oxide Interfaces

Understanding the nature of charge carriers at the LaAlO3/SrTiO3 interface is one of the major open issues in the full comprehension of the charge confinement phenomenon in oxide heterostructures. Here, we investigate thermopower to study the electronic structure in LaAlO3/SrTiO3 at low temperature as a function of gate field. In particular, under large negative gate voltage, corresponding to the strongly depleted charge density regime, thermopower displays record-high negative values of the order of 10^4 - 10^5 microV/K, oscillating at regular intervals as a function of the gate voltage. The huge thermopower magnitude can be attributed to the phonon-drag contribution, while the oscillations map the progressive depletion and the Fermi level descent across a dense array of localized states lying at the bottom of the Ti 3d conduction band. This study is the first direct evidence of a localized Anderson tail in the two-dimensional (2D) electron liquid at the LaAlO3/SrTiO3 interface.Comment: Main text: 28 pages and 3 figures; Supplementary information: 29 pages, 5 figures and 1 tabl

Effect of pre-bloom anti-transpirant treatments and leaf removal on 'Sangiovese' (Vitis vinifera L.) winegrapes

Recent trials have shown that basal shoot leaf removal at pre-bloom is effective in reducing fruit-set and yield, leading to better grape quality composition. The present trial was designed to determine whether similar results can be achieved with 'Sangiovese' vines by testing a pre-bloom spray of film-forming anti-transpirant (P) against pre-bloom hand defoliation of basal shoots (HD) and no defoliation (C). The results of our threeyear experiment show that, compared to C, P reduced net assimilation of treated leaves for 20-40 days and photosynthetic compensation was not found after treatments in the upper untreated leaves of P and in the remaining upper HD leaves; berry-set, cluster weight and yield were significantly reduced in P and HD; bunch compactness decreased in HD, with P clusters registering an intermediate value; must soluble solids content (°Brix) and pH of P and HD were higher; no differences were found among treatments for titratable acidity. Berry and skin weight and anthocyanin content of P and C berries were similar, whereas HD berries, which were fully exposed to ambient light and temperature throughout each season, showed higher skin weight and skin weight-to-berry weight ratio, but a decreasing of total skin anthocyanins content compared to C and P.

Application of kaolin and italian natural chabasite-rich zeolitite to mitigate the effect of global warming in vitis vinifera l. Cv. sangiovese

High temperatures and the anomalous distribution of rainfall during the growing season may have a negative impact on grapevine yield and berry composition. In recent years, many studies have focused on the application of agronomical techniques to reduce the negative impact of heat waves on secondary metabolites such as phenols. In particular, treatments with kaolin have shown positive effects on reducing canopy temperatures, enhancing the accumulation of anthocyanins. In regard to the above, three treatments were evaluated: untreated control (C), kaolin (CAO), and chabasite-rich zeolitites (ZEO) applications on cv. Sangiovese in order to verify the cooling effects on leaves and bunches, and the impact on gas exchange, yield parameters, berry composition, and on both chemical and sensory notes of wine. Minerals were sprayed twice around the veraison on the entire canopy at a 3% concentration. The results showed that the application of the minerals was able to reduce the berry temperatures in both years of the trial as compared to the untreated control (C), without affecting vine gas exchange, yield, and soluble solid accumulation. Furthermore, the cooling effect determined an increase in anthocyanin on both the grapes and the wine. At testing, CAO and ZEO wines stood out regarding greater color intensity and were preferred by the judges

Double exchange-driven spin pairing at the (001) surface of manganites

The (001) surface of La_{1-x}Ca_xMnO_3 system in various magnetic orderings is studied by first principle calculations. A general occurrence is that z^2 dangling bond charge -- which is ``invisible'' in the formal valence picture -- is promoted to the bulk gap/Fermi level region. This drives a double-exchange-like process that serves to align the surface Mn spin with its subsurface neighbor, regardless of the bulk magnetic order. For heavy doping, the locally ``ferromagnetic'' coupling is very strong and the moment enhanced by as much as 30% over the bulk value.Comment: 6 pages, 4 figure

Effects of Mechanical Winter Pruning on Vine Performances and Management Costs in a Trebbiano Romagnolo Vineyard: A Five-Year Study

Vineyard mechanical winter pruning has been spreading worldwide, and the physiological basis ascribable to it has been consolidated throughout the years. Despite labor savings and reduction of costs having been proven, the demonstration of its economic viability might be challenging. In this context, this work aims to evaluate the vine performances and the costs of different degrees of the mechanization of winter pruning over a five-year trial (2011-2015). In a vineyard of cv. Trebbiano Romagnolo (Vitis vinifera L.) located in northern Italy, three pruning treatments were laid out as follows: (a) manual pruning (MAN); (b) mechanical pre-pruning and simultaneous manual follow-up (MP + F); (c) mechanical pruning without a manual follow-up (MP). The results showed a strong increase in the node number of MP. Nevertheless, the yield compensation factors (i.e., the shoot fruitfulness and cluster weight) limited the increase in productivity. Soluble solids did not differ between the pruning treatments, while titratable acidity resulted slightly higher only on the MP berries. The MP treatment was the most economically convenient, with a vineyard surface of 1.5 hectares, while mechanical pruning with manual finishing resulted more advantageous, compared to manual pruning when the vineyard surface was greater than 2.9 hectares. The agronomic and economic results obtained in this five-year trial suggest that mechanical pruning may be profitably applied also on grapevine varieties characterized by low basal bud fruitfulness, such as Trebbiano Romagnolo

Magnetic stress as a driving force of structural distortions: the case of CrN

We show that the observed transition from rocksalt to orthorhombic P$_{nma}$ symmetry in CrN can be understood in terms of stress anisotropy. Using local spin density functional theory, we find that the imbalance between stress stored in spin-paired and spin-unpaired Cr nearest neighbors causes the rocksalt structure to be unstable against distortions and justifies the observed antiferromagnetic ordering. This stress has a purely magnetic origin, and may be important in any system where the coupling between spin ordering and structure is strong.Comment: 4 pages (two columns) 4 figure