416 research outputs found
Optically induced spin to charge transduction in donor spin read-out
The proposed read-out configuration D+D- for the Kane Si:P
architecture[Nature 393, 133 (1998)] depends on spin-dependent electron
tunneling between donors, induced adiabatically by surface gates. However,
previous work has shown that since the doubly occupied donor state is so
shallow the dwell-time of the read-out state is less than the required time for
measurement using a single electron transistor (SET). We propose and analyse
single-spin read-out using optically induced spin to charge transduction, and
show that the top gate biases, required for qubit selection, are significantly
less than those demanded by the Kane scheme, thereby increasing the D+D-
lifetime. Implications for singlet-triplet discrimination for electron spin
qubits are also discussed.Comment: 8 pages, 10 figures; added reference, corrected typ
Gametic and somatic embryogenesis through in vitro anther culture of different Citrus genotypes
Abstract: In vitro tissue culture represents a useful technique for advancing Citrus breeding and propagation. Among in vitro regeneration systems, anther culture is commonly used to produce haploids and doubled haploids for a fast-track producing homozygous lines, in comparison with the traditional self-pollination approach, which involves several generations of selfing. In addition, anthers culture can produce somatic embryos that can also be used for clonal propagation. In this study, two thermal shocks were applied to the anthers of six Citrus genotypes (two clementine and four sweet oranges), just after they were put in culture. The response obtained was different depending on the genotype: both clementines, namely Hernandina and Corsica, produced homozygous and triploid regenerants (microspore-derived embryos), whereas all of the analyzed regenerants from sweet oranges, three cultivars of Tarocco and Moro, produced heterozygous and diploid regenerants similar to the parental genotypes (somatic embryos)
Quality of Living Perceived of the Young People of the Vale do Sinos / RS/Brazil
The objective of this study was to identify the Quality of Life level of young people from Vale do Sinos / RS. The methodology was observational, descriptive and transversal. The sample had 391 young people. The data collection instruments were the WHOQOL-Bref and a socioeconomic questionnaire. Resulting in a total average score of 52.37 points, the highest for the Social Relations Domain and the lowest for the Environment. When compared to the variables "Sex", "Income" and "Age", the one with the highest statistically significant association among the domains was "Income", followed by "Sex" and "Age". It was concluded that the QoL of young people is smaller when compared with other studies, being relevant investments in public policies
Global distribution and bioclimatic characterization of alpine biomes
BJ-A thanks the Marie Curie Clarín-COFUND program of the Principality of Asturias-EU (ACB17-26) and the regional grant IDI/2018/000151 for research groups
Effect of biostimulants on apple quality at harvest and after storage
Nutritional unbalances, such as calcium deficiency at the fruit level, are generally the causative agent of post-harvest disorders in apples. Foliar application of Ca as calcium chloride is the current solution to increase Ca concentration in apples, even though the effectiveness of this approach is often not satisfactory. In this research, we tested the efficacy of a combined application of Ca with selected biostimulants to improve apple quality and to reduce the incidence of storage disorders. The experiment was conducted in two \u201cJonathan\u201d apple orchards that differed in management systems and characteristics. Tree canopies were sprayed with calcium chloride alone and in combination with a commercial product containing zinc and silicon or a seaweed extract. The seaweed extract increased apple quality by boosting the reddish coloration (+32% of color index) and by enhancing final anthocyanin concentration of fruit skin. Both biostimulants significantly reduced (by 20%) the incidence of the physiological disorder, known as \u201cJonathan spot\u201d, after 160 days of storage. Increased concentration of nutrients (Ca, Zn, and Mn) in the skin of apples after biostimulant applications, together with changes of the phenolic profile during the storage, are discussed as the possible causes of the reduced fruit susceptibility to post-harvest disorders
Floristic changes of vascular flora in the city of Rome through grid-cell census over 23 years
Cities are considered important areas for biodiversity and host a high plant species richness. However, many factors, such as urbanisation or changes in land use, can affect the presence of spontaneous flora and, consequently, represent a threat for biodiversity. How species respond to these factors of change in cities over time is a relevant and current issue and spatiotemporal analyses represent an essential step forward to better understand these dynamic systems and to fill gaps of knowledge. In this paper we present a comparison between a floristic survey carried out in 1995 on a grid-cell for the city of Rome and a new survey, performed between 2015 and 2018, in order to verify if the species composition significantly changed over time and to which drivers this change was related to. For 76 grid-cells of the raster, each of which of 1.6 km(2), we recorded all spontaneous vascular species. We analysed the differences between the two surveys by means of statistical tests on species richness, by species turnover, by generalised linear models (GLMs) and by Ellenberg indicator values. The patterns of species richness are similar between the two surveys, although an increase in the number of species per grid-cell, on average, was observed. This increase regarded both native and alien richness, with significant differences only for aliens. Many species significantly reduced or increased their frequencies, comparing the two surveys. A set of environmental variables, among which the presence of protected areas, are relevant for explaining the pattern of species' frequencies and its change over time. Our results suggest that the flora of the city, notwithstanding the steady human pressure and the increase in alien species, maintained a high level of heterogeneity
Floristic changes of vascular flora in the city of Rome through grid-cell census over 23 years
Area, environmental heterogeneity, scale and the conservation of alpine diversity
AimArea and environmental heterogeneity together explain most patterns of species diversity but disentangling their relative importance has been difficult. Here, we empirically examined this relationship and parsed their relative importance, and that of the heterogeneity-effective area trade-off, at different spatial scales and in different spatial representations in simulations. LocationAlpine grasslands of 23 mountain ranges of southern and central Europe. TaxonVascular plants. MethodsWe developed metrics of climatic and edaphic heterogeneity, using principal components analyses and the shoelace algorithm, and added elevation range. We applied commonality analysis to partition the unique and shared explanation of the observed vascular plant species richness among selected metrics. A simulation was developed to separate the relative importance of area and heterogeneity at different extents and representations of spatial nestedness, and the heterogeneity-effective area trade-off was evaluated by altering spatial discreteness. ResultsThe explanation of the observed regional richness was shared by area and heterogeneity. The simulation revealed that heterogeneity was consistently more important, but less so among smaller areas. This qualitative pattern was maintained regardless of whether and how nestedness was represented. The heterogeneity-effective area trade-off occurred in a few simulations of more discrete habitats. Main ConclusionsScale dependence may account for discrepancies among past empirical studies wherein environmental heterogeneity has usually outweighed area in the explanation of species richness; and it is not affected by nestedness. The potential heterogeneity-effective area trade-off may be limited to locations where the environmental heterogeneity is quite discrete or if the added environment is beyond the niches of any species in the potential pool. The significant importance of area per se in small territories indicates that microrefugia, even with an unlikely full range of heterogeneity, will suffer local extinctions in the face of climate change
- …
