Two-qubit non-Markovianity induced by a common environment

We study non-Markovianity as backflow of information in two-qubit systems. We consider a setting where, by changing the distance between the qubits, one can interpolate between independent reservoir and common reservoir scenarios. We demonstrate that non-Markovianity can be induced by the common reservoir and single out the physical origin of this phenomenon. We show that two-qubit non-Markovianity coincides with instances of non-divisibility of the corresponding dynamical map, and we discuss the pair of states maximizing information flowback. We also discuss the issue of additivity for the measure we use and in doing so, give an indication of its usefulness as a resource for multipartite quantum systems.Comment: 9 pages, 5 figures, Published version with minor modification

GaAs solar cells for laser power beaming

Efforts to develop GaAs solar cells for coupling to laser beams in the wavelength range of 800 to 840 nm are described. This work was motivated primarily by interests in space-tp-space power beaming applications. In particular, the Battelle Pacific Northwest Laboratories is conducting studies of the utilization of power beaming for several future space missions. Modeling calculations of GaAs cell performance were carried out using PC-1D to determine an appropriate design for a p/n cell structure. Epitaxial wafers were grown by MOCVD and cells fabricated at WSU Tri-Cities. Under simulated conditions, an efficiency of 53 percent was achieved for a cell coupled to 806 nm light at 400 mW/sq cm

Ulva as potential stimulant and attractant for a valuable sea urchin species: a chemosensory study

The green seaweed Ulva is close to becoming popular due to its suitability as potential feedstock production and for food items. However, there is a general lack of studies on the aversion or acceptability of this alga by marine organisms, particularly on its role as a chemoattractant and/or phagostimulant activity. Here we tested the effect of Ulva compressa and other biochemicals as potential chemostimulating compounds for a valuable sea urchin species, Paracentrotus lividus, selected as model species for our tests. Sea urchins’ chemical sensitivity was estimated by analysing movements of spines, pedicellariae, tube feet, and individual locomotion using an innovative bioassay. Our results showed that all forms of Ulva (fresh, defrosted, and fragmented) resulted in an effective stimulus, evoking in sea urchins strong responses with robust activation of spines and tube feet, where the defrosted one was the most stimulating. Among the amino acids tested, glycine, alanine, and glutamine produced a significant response, highlighting for the latter a concentration–response relationship. Sea urchins responded to glucose, not to fructose and sucrose. Spirulina resulted as the most effective stimulus, acting in a dose-dependent manner. Major results indicate the role of Ulva as a chemostimulant and strongly attractant for such herbivore species. From an applied point of view, the presence of potential Ulva’s feed-related compounds, acting as chemoattractants (to reduce food searching time) and/or feeding stimulants (to stimulate ingestion), would improve the several applications of Ulva in the formulation of the feeds for sustainable aquacultur

Outcomes of feeding activity of the sea cucumber Holothuria tubulosa on quantity, biochemical composition, and nutritional quality of sedimentary organic matter

Introduction: Holothuria tubulosa is one of the most common sea cucumbers in the Mediterranean Sea, generally associated with organically enriched coastal sediments and seagrass beds. As a deposit-feeder, it is responsible for strong bioturbation processes and plays a putative key role in sedimentary carbon cycling and benthic trophodynamics. With the aim of exploring the potential use of holothuroids as a tool for remediating eutrophicated sediments, we investigated the effects of H. tubulosa on sedimentary organic matter quantity, biochemical composition, and nutritional quality. Methods: Holothuroids and associated samples of ambient sediments were collected in two sites located in the Central-Western Mediterranean Sea (Sardinia, Italy) and characterized by different trophic status backgrounds: the site of Oristano characterized by sandy-muddy sediments and the presence of mariculture plants (ranked as meso-eutrophic) and the site of Teulada characterized by sandy sediments and Posidonia oceanica meadows (ranked as oligo-mesotrophic). We compared the biochemical composition (proteins, carbohydrates, lipids) of ambient sediment vs sea cucumbers feces and the sedimentary protein content vs protein content in the sediments retrieved in different gut sections (esophagus, mid gut, end gut) of the holothuroid. Results: Our results reveal that holothuroids feeding on meso-eutrophic sediments can increase protein (1.5 times) and lipid (1.3 times) content through their defecation, thus making these substrates a more labile food source for other benthic organisms. We report here that H. tubulosa feeding on meso-eutrophic sediment is most likely able to actively select particles rich in labile organic matter with buccal tentacles, as revealed by the protein content in the esophagus that is up to 2-folds higher than that in the source sediment. According to the inverse relationship between assimilation rates and availability of organic substrates and the optimal foraging theory, H. tubulosa feeding on oligo-mesotrophic sediments showed potential assimilation of proteins ca. 25% higher than that of specimens feeding on meso-eutrophic sediments. Discussion: Our results reveal that H. tubulosa feeding on meso-eutrophic sediments can profoundly influence the benthic trophic status, specifically modifying the biochemical composition and nutritional quality of organic matter, thus paving the way to its possible use in bioremediation actions of eutrophicated sediments and in Integrated Multi-Trophic Aquaculture systems

Evaluation of automated emergency response systems

Automated Emergency Response (ER) systems are playing a greater role in providing prompt and reliable predictions of the impact of inadvertent releases of hazardous materials to the environment. Observed and forecast environmental and accident source term data are input into environmental transport and dispersion models to provide dosimetry estimates used as decision making aids for responding to emergencies. Several automated ER systems have been developed for US Federal Government facilities and many are available commercially. For such systems to be useful, they must reliably and consistently deliver a timely product to the decision makers. Evaluation of the entire ER system is essential to determine the performance that can be expected from the system during an emergency. Unfortunately, seldom are ER systems evaluated as a whole. Usually Quality Assurance programs evaluate the performance of individual components of the system. Most atmospheric pollution model evaluation methods usually involve an evaluation of the predictive performance of the transport and dispersion model when compared either with experimental tracer results or results from other models. Rarely, however, is the ability of the ER system to provide timely, reliable and consistent information evaluated. Such an evaluation is vital to determine the system performance during an emergency and to provide valuable information to aid in improving the system

Improving pacific oyster (Crassostrea gigas, Thunberg, 1793) production in Mediterranean coastal lagoons: Validation of the growth model “ShellSIM” on traditional and novel farming methods

Bivalve farming is a major European aquaculture activity, representing 48.5% of total biomass produced. Italy is one of the largest consumers of oysters but local production does not meet the market demand. Italy has approximately 384,000 ha of shallow lagoons in its coastal area, already devoted to extensive aquaculture activities, which could also represent potential locations for Pacific oyster (Crassostrea gigas, Thunberg, 1793) farming. The aim of this study is to enhance Pacific oyster farming in shallow coastal lagoons by testing novel farming technologies and validating an existing bioenergetic growth model (ShellSIM). Commercial performance of Pacific oysters and associated environmental parameters were monitored in two Sardinian coastal lagoons (San Teodoro and Santa Gilla, Italy). Oyster growth and survival were compared during a production cycle for two rearing systems: traditional systems (floating bags or lanterns) and Ortac units. The latter has not been previously tested in coastal lagoons. Measured performances were compared with ShellSIM predictions to evaluate the model's ability to predict growth and the potential production in other coastal lagoons. Results showed that at the end of a six months cycle the oysters mean weight and Condition Index were significantly higher (p valu

Clinical Evidence: a useful tool for promoting evidence-based practice?

Background: Research has shown that many healthcare professionals have problems with guidelines as they would prefer to be given all relevent information relevent to decision-making rather than being told what they should do. This study assesses doctors' judgement of the validity, relevance, clarity and usability of the Italian translation of Clinical Evidence (CE) after its free distribution launched by the Italian Ministry of Health. Methods: Opinions elicited using a standardised questionnaire delivered either by mail or during educational or professional meetings. Results: Twenty percent (n = 1350) doctors participated the study. Most of them found CE's content valid, useful and relevant for their clinical practice, and said CE can foster communications among clinicians, particularly among GPs and specialists. Hospital doctors (63%) more often than GPs (48%) read the detailed presentation of individual chapters. Twenty-nine percent said CE brought changes in their clinical practice. Doctors appreciated CE's nature of an evidence-based information compendium and would have not preferred a collection of practice guidelines. Conclusions: Overall, the pilot initiative launched by the Italian Ministry of Health seems to have been well received and to support the subsequent decision to make the Italian edition of Clinical Evidence concise available to all doctors practising in the country. Local implementation initiatives should be warranted to favour doctor's use of CE

Socioeconomic Profile and Gender Characteristics in Relation to Camel Management Practices in the Pastoral Communities of Ethiopia

Pastoralism was one of the oldest forms of organized human society in providing sustainable livelihood opportunities. However, this way of life is increasingly under threat due to a number of reasons. Today’s political, legal, social and economic policies and laws are not taking into consideration the needs of pastoral populations specially women and children. An attempt has been made to evaluate the socio-economic conditions among the pastoral households of Eastern and Southern parts of Ethiopia. The study involved three major pastoral areas of Ethiopia, namely, Somali, Afar and Oromiya regional states. The findings of this study revealed that lacking of formal education except limited religious education for male children, girl children are excluded from any type of literacy. Population size in the study areas reflects above national average, due to custom of polygon. Regionally there has been a variation in decision making on the issues like intensity of production, breeding, camel herding, milking, marketing and other related activities. In general this study observed that there has been a dominant role played by men in most of the revenue generating activities except in few areas of districts other than economic activities. Hence, different types of social and policy intervention should be made. Keywords: Pastoralism, education, Polygon, intensity of production, Breeding