2,628 research outputs found
Distributing fully optomechanical quantum correlations
We present a scheme to prepare quantum correlated states of two mechanical
systems based on the pouring of pre-available all-optical entanglement into the
state of two micro-mirrors belonging to remote and non-interacting
optomechanical cavities. We show that, under realistic experimental conditions,
the protocol allows for the preparation of a genuine quantum state of a
composite mesoscopic system whose non-classical features extend far beyond the
occurrence of entanglement. We finally discuss a way to access such mechanical
correlations.Comment: 5 pages, 4 figures, to appear in Physical Review
The Relationship between Restricted, Repetitive Behavior and Anxiety in Adults with Intellectual Disability
This study investigated the relationship between restricted, repetitive behavior (RRB) and anxiety in a sample of adults with intellectual disability (ID). Six regression analyses were conducted. Predictor variables were age, severity of autism spectrum disorder (ASD) symptoms, level of adaptive functioning, and anxiety; RRB (in general and specific subtypes) was the criterion. Together, the four predictor variables accounted for a significant proportion of the variance in total RRB, Stereotypic Behavior, Compulsive Behavior, Ritualistic/Sameness Behavior, and Restricted Interests. Self-injurious behavior (SIB) was the only subtype of RRB in which the results of the regression analysis were not significant. Anxiety was found to independently account for a significant proportion of the variance in total RRB, Compulsive Behavior, and Ritualistic/Sameness Behavior. This suggests that changes in RRB in general and in particular subtypes, specifically compulsive behavior and ritualistic/sameness behavior, may be observable indicators of anxiety in adults with ID. Overall, this study highlights the need for more research on RRB in general and on the relationship between RRB and anxiety, especially across different populations and settings
Improving operation of a complex headworks system for municipal use and hydropower production by mathematical programming
The paper presents a Mixed Integer Non Linear Programming (MINLP) model of the water resources system supplying Genoa, in northern Italy. The system presently features five reservoirs, three main river intakes, and two well fields. The hydrological regime is typically Mediterranean; water availability is however relatively abundant, so that drought issues are limited, especially now that water demand from the supply sources has decreased due to reduced population, deindustrialization and to improvement in the operation and maintenance of the water distribution network. In this context, it is worthwhile considering the possibility to relax an over-conservative management of resources, justified by the experience of previous drought events, and to explore the viability of exploiting resources from reservoirs for hydropower production.
The MINLP model expresses cost minimization over a 40 year time period on a monthly basis, subject to physical constraints. Costs include scarcity costs (the economic value of possible water deficits) and extraction costs from wells, minus hydropower production. The model has been written in GAMS and solved through the SBB (Simple Branch and Bound) solver.
Results show that the system is able to meet demand over the 40 year hydrologic scenario with negligible water deficits and that hydropower production may be enhanced compared to present by increasing releases from reservoirs, which ultimately implies accepting keeping reservoirs emptier than presently done
Improvement through process integration using a simulative, dynamic method
The need for globalisation, the saturation and instability of markets, the life-cycle time reduction of products, the growth of item variety, the customer demands have been main factors contributing to a radical change of management conceptions and strategies. This complex environment has induced companies to search the keys to achieve competitiveness, focusing on process integration. The purpose of the paper is to explain how managing the internal functions of a company in an integrated way can lead to an effective improvement. In order to represent the flows and to quantify improvements, a simulative, dynamic and integrated model is developed
On second order necessary conditions in infinite dimensional optimal control with state constraints
This paper is devoted to second order necessary optimality conditions for control problems in infinite dimensions. The main novelty of our work is the presence of pure state constraints together with end point constraints, quite useful in the applications. Second order analysis for control problems involving PDEs has been extensively discussed in the literature. The most usual approach to derive necessary optimality conditions is to rewrite the control problem as an abstract mathematical programming one. Our approach is different, we avoid the reformulation of the optimal control problem and use instead second order variational analysis. The necessary optimality conditions are in the form of a maximum principle and a second order variational inequality. They are first obtained in the form of nonintersection of convex sets. A suitable separation theorem allows to deduce their dual characterization
Wheat Cultivar-Specific Selection of 2,4-Diacetylphloroglucinol-Producing Fluorescent \u3ci\u3ePseudomonas\u3c/i\u3e Species from Resident Soil Populations
An emerging body of evidence indicates a role for plant genotype as a determinant of the species and genetic composition of the saprophytic microbial community resident to the rhizosphere. In this study, experiments were conducted to determine the capacity of five different wheat cultivars to enhance resident populations and support introduced strains of 2,4-diacetylphloroglucinol (2,4-DAPG)-producing fluorescent pseudomonads, a group of bacteria known to provide biological control of several soilborne diseases. When soils were cropped with three successive 28-day growth cycles of wheat, the 2,4- DAPG-producing strains were consistently recovered from the rhizosphere of the cultivar Lewjain, and commonly were present at populations higher than those recovered from other wheat cultivars. Based on restriction fragment length polymorphism and sequence analyses of phlD, a key gene involved in 2,4-DAPG production, two previously undefined phlD+ genotypes, referred to as genotypes PfZ and PfY, were discovered. Wheat cultivar Lewjain was the primary source of genotype PfY while cultivar Penawawa yielded the majority of genotype PfZ. Based on 16S rDNA sequence analysis, both new phlD genotypes were classified as P. fluorescens. Comparison of the rhizosphere competence of 2,4-DAPG-producing P. fluorescens Q2-87 (genotype B) and P. fluorescens LR3-A28 (genotype PfY) showed that both strains persisted at similar populations in the rhizosphere of all cultivars tested over a 30 day period when introduced as a seed inoculant. However, when strain LR3-A28 was applied as a soil inoculant, this strain was recovered at higher populations from the rhizosphere of wheat cultivar Lewjain than from the rhizospheres of two other cultivars. No cultivar effects were shown for strain Q2-87. Collectively, these results add further to evidence indicating a degree of specificity in interactions between plant cultivars and specific members of the saprophytic microbial community. Furthermore, as 2,4- DAPG-producing fluorescent Pseudomonas spp. have a central role in the spontaneous reduction in severity of take-all disease of wheat in response to continuous wheat monoculture, we postulate that the use of specific cultivars, such as Lewjain, which possess a superior capacity to enhance resident soil populations of these bacteria may have potential to reduce the length of the monoculture period required to induce natural suppressiveness of soils toward this disease
Phenomenological memory-kernel master equations and time-dependent Markovian processes
Do phenomenological master equations with memory kernel always describe a
non-Markovian quantum dynamics characterized by reverse flow of information? Is
the integration over the past states of the system an unmistakable signature of
non-Markovianity? We show by a counterexample that this is not always the case.
We consider two commonly used phenomenological integro-differential master
equations describing the dynamics of a spin 1/2 in a thermal bath. By using a
recently introduced measure to quantify non-Markovianity [H.-P. Breuer, E.-M.
Laine, and J. Piilo, Phys. Rev. Lett. 103, 210401 (2009)] we demonstrate that
as far as the equations retain their physical sense, the key feature of
non-Markovian behavior does not appear in the considered memory kernel master
equations. Namely, there is no reverse flow of information from the environment
to the open system. Therefore, the assumption that the integration over a
memory kernel always leads to a non-Markovian dynamics turns out to be
vulnerable to phenomenological approximations. Instead, the considered
phenomenological equations are able to describe time-dependent and
uni-directional information flow from the system to the reservoir associated to
time-dependent Markovian processes.Comment: 5 pages, no figure
Sepiolinae (Mollusca: Cephalopoda) from the Strait of Sicily
Nine species belonging to three genera of the subfamily Sepiolinae (Leach, 1817) were collected in the Strait of Sicily by two series of bottom trawl surveys carried out during the years 1985-87 and 1992: Sepiola rondeletii, Sepiola intermedia, Sepiola ligulata, Sepiola robusta, Sepiola affinis, Sepietta oweniana, Sepietta neglecta, Sepietta obscura and Rondeletiola minor. For each species, abundance, distribution, sex ratio and maturity condition were analysed. S. oweniana was the most abundant species, followed by R. minor, while the single record of S. ligulata indicates that the species is rare in the area. The bathymetric distributions observed generally agree with what is known for the species from the literature, but present data support the extension of the bathymetric range inhabited by S. robusta (down to 498 m). Mature specimens represented 81.8% of the examined sample, and no substantial differences in the percentages of mature individuals with season was noticeable; this supports the existence of an extended reproductive period in the Sepiolines
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