Anomalous double peak structure in Nb/Ni superconductor/ferromagnet tunneling DOS

We have experimentally investigated the density of states (DOS) in Nb/Ni (S/F) bilayers as a function of Ni thickness, $d_F$. Our thinnest samples show the usual DOS peak at $\pm\Delta_0$, whereas intermediate-thickness samples have an anomalous ``double-peak'' structure. For thicker samples ($d_F \geq 3.5$ nm), we see an ``inverted'' DOS which has previously only been reported in superconductor/weak-ferromagnet structures. We analyze the data using the self-consistent non-linear Usadel equation and find that we are able to quantitatively fit the features at $\pm\Delta_0$ if we include a large amount of spin-orbit scattering in the model. Interestingly, we are unable to reproduce the sub-gap structure through the addition of any parameter(s). Therefore, the observed anomalous sub-gap structure represents new physics beyond that contained in the present Usadel theory.Comment: 4 pages, 3 figure

Solid CO_2 in low-mass young stellar objects: Comparison between Spitzer and laboratory spectra

Context. Solid interstellar CO_2 is an abundant component of ice dust mantles. Its ubiquity towards quiescent molecular clouds, as well as protostellar envelopes, has recently been confirmed by the IRS (InfraRed Spectrograph) aboard the Spitzer Space Telescope. Although it has been shown that CO_2 cannot be efficiently formed in the gas phase, the CO_2 surface formation pathway is still unclear. To date several CO_2 surface formation mechanisms induced by energetic (e.g., UV photolysis and cosmic ray irradiation) and non-energetic (e.g., cold atom addition) input have been proposed. Aims. Our aim is to investigate the contribution of cosmic ray irradiation to the formation of CO_2 in different regions of the interstellar medium (ISM). To achieve this goal we compared quantitatively laboratory data with the CO_2 bending mode band profile observed towards several young stellar objects (YSOs) and a field star by the Spitzer Space Telescope. Methods. All the experiments presented here were performed at the Laboratory for Experimental Astrophysics in Catania (Italy). The interstellar relevant samples were all irradiated with fast ions (30−200 keV) and subsequently annealed in a stainless steel high vacuum chamber (P < 10^(-7) mbar). Chemical and structural modifications of the ice samples were monitored by means of infrared spectroscopy. Laboratory spectra were then used to fit some thirty observational spectra. Results. A qualitative analysis shows that a good fit can be obtained with a minimum of two components. The choice of the laboratory components is based on the chemical-physical condition of each source. A quantitative analysis of the sources with known visual extinction (A_V) and methanol abundances highlights that the solid carbon dioxide can be efficiently and abundantly formed after ion irradiation of interstellar ices in all the selected YSOs in a time compatible with cloud lifetimes (3 × 10^7 years). Only in the case of field stars can the expected CO_2 column density formed upon energetic input not explain the observed abundances. This result, to be confirmed along the line of sight to different quiescent clouds, gives an indirect indication that CO_2 can also be formed in an early cloud stage through surface reactions induced by non-energetic mechanisms. In a later stage, when ices are exposed to higher UV and cosmic ray doses, the CO_2 total abundance is strongly affected by energetic formation mechanisms. Conclusions. Our results indicate that energetic processing of icy grain mantles significantly contribute to the formation of solid phase interstellar CO_2

Does organic farming increase raspberry quality, aroma and beneficial bacterial biodiversity?

Plant-associated microbes can shape plant phenotype, performance, and productivity. Cultivation methods can influence the plant microbiome structure and differences observed in the nutritional quality of differently grown fruits might be due to variations in the microbiome taxonomic and functional composition. Here, the influence of organic and integrated pest management (IPM) cultivation on quality, aroma and microbiome of raspberry (Rubus idaeus L.) fruits was evaluated. Differences in the fruit microbiome of organic and IPM raspberry were examined by next-generation sequencing and bacterial isolates characterization to highlight the potential contribution of the resident-microflora to fruit characteristics and aroma. The cultivation method strongly influenced fruit nutraceutical traits, aroma and epiphytic bacterial biocoenosis. Organic cultivation resulted in smaller fruits with a higher anthocyanidins content and lower titratable acidity content in comparison to IPM berries. Management practices also influenced the amounts of acids, ketones, aldehydes and monoterpenes, emitted by fruits. Our results suggest that the effects on fruit quality could be related to differences in the population of Gluconobacter, Sphingomonas, Rosenbergiella, Brevibacillus and Methylobacterium on fruit. Finally, changes in fruit aroma can be partly explained by volatile organic compounds (VOCs) emitted by key bacterial genera characterizing organic and IPM raspberry fruit

Characterization of the Neuroligin gene family expression and evolution in zebrafish

Neuroligins constitute a family of transmembrane proteins localized at the postsynaptic side of both excitatory and inhibitory synapses of the central nervous system. They are involved in synaptic function and maturation and recent studies have linked mutations in specific human Neuroligins to mental retardation and autism. We isolated the human Neuroligin homologs in Danio rerio. Next, we studied their gene structures and we reconstructed the evolution of the Neuroligin genes across vertebrate phyla. Using reverse-transcriptase polymerase chain reaction, we analyzed the expression and alternative splicing pattern of each gene during zebrafish embryonic development and in different adult organs. By in situ hybridization, we analyzed the temporal and spatial expression pattern during embryonic development and larval stages and we found that zebrafish Neuroligins are expressed throughout the nervous system. Globally, our results indicate that, during evolution, specific subfunctionalization events occurred within paralogous members of this gene family in zebrafish

Variation of leaf litter decomposition among rivers, lagoons and sea: an experiment from Corfu island (Greece)

In aquatic ecosystems, the decomposition of organic detritus represents one of the most important ecosystem functions, which support complex detritus-based food webs that determine the critical balance between carbon mineralization and sequestration. The performance of the decomposition process is usually expressed as rate of decomposition, being a synthetic measure that take into account both abiotic and biotic factors. Decomposition rates have been also applied to evaluate the ecological status in terms of ecological functionality. However, despite a growing number of studies have tested the rate of decomposition between leaves of different riparian tree species in different aquatic ecosystems including rivers, transitional waters and sea, no comparative study among ecosystems typology is available up to date. Here, we compare decomposition rates from rivers, lagoons and sea of Corfu island (Greece). Five sampling sites were fixed in each of the three of the most important rivers and lagoons; other five sampling sites were fixed in the sea around the island. Twelve leaf packs containing 3±0.005 g of oven-dried Phragmites australis leaves were submerged in April 2014 and retrieved in May 2014 (after 30 days). Abiotic parameters were recorded in both sampling times. The retrieved leaf packs were cleaned and the macroinvertebrates retained were removed, counted, identified at lower taxonomic level and weighted. Leaf pack decomposition rates were calculated, and their variability was compared within each aquatic ecosystem, within each ecosystem typology (river, lagoon, sea) and among ecosystem typology. The results are going to be presented on the poster

A New Limit on the Neutrinoless DBD of 130Te

We report the present results of CUORICINO a cryogenic experiment on neutrinoless double beta decay (DBD) of 130Te consisting of an array of 62 crystals of TeO2 with a total active mass of 40.7 kg. The array is framed inside of a dilution refrigerator, heavily shielded against environmental radioactivity and high-energy neutrons, and operated at a temperature of ~8 mK in the Gran Sasso Underground Laboratory. Temperature pulses induced by particle interacting in the crystals are recorded and measured by means of Neutron Transmutation Doped thermistors. The gain of each bolometer is stabilized with voltage pulses developed by a high stability pulse generator across heater resistors put in thermal contact with the absorber. The calibration is performed by means of two thoriated wires routinely inserted in the set-up. No evidence for a peak indicating neutrinoless DBD of 130Te is detected and a 90% C.L. lower limit of 1.8E24 years is set for the lifetime of this process. Taking largely into account the uncertainties in the theoretical values of nuclear matrix elements, this implies an upper boud on the effective mass of the electron neutrino ranging from 0.2 to 1.1 eV. This sensitivity is similar to those of the 76Ge experiments.Comment: 4 pages, 2 figure

Double-beta decay of 130^{130}Te to the first 0+^{+} excited state of 130^{130}Xe with CUORICINO

The CUORICINO experiment was an array of 62 TeO$_{2}$ single-crystal bolometers with a total $^{130}$Te mass of $11.3\,$kg. The experiment finished in 2008 after more than 3 years of active operating time. Searches for both $0\nu$ and $2\nu$ double-beta decay to the first excited $0^{+}$ state in $^{130}$Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N($^{130}$Te)$\cdot$t=$9.5\times10^{25}\,$y. No evidence for a signal was found. The resulting lower limits on the half lives are $T^{2\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>1.3\times10^{23}\,$y (90% C.L.), and $T^{0\nu}_{1/2}(^{130} Te\rightarrow^{130} Xe^{*})>9.4\times10^{23}\,$y (90% C.L.).Comment: 6 pages, 4 figure