1,087 research outputs found
Magnetohydrodynamic properties of incompressible Meissner fluids
We consider a superconducting material that exists in the liquid state, more
precisely, in which the Meissner-Ochsenfeld effect persists in the liquid
state. First, we investigate how the shape of such a hypothetical Meissner
liquid will adapt to accomodate for an applied external field. In particular,
we analyse the case of a droplet of Meissner fluid, and compute the elongation
of the droplet and its quadrupole frequency as a function of the applied field.
Next, the influence of an applied field on the flow of the liquid is studied
for the case of a surface wave. We derive the dispersion relation for surface
waves on an incompressible Meissner fluid. We discuss some candidate
realizations of the Meissner fluids and for the case of a superconducting
colloid discuss which regime of wave lengths would be most affected by the
Meissner effect.Comment: 12 pages, 3 figure
The Sleep Condition Indicator: a clinical screening tool to evaluate insomnia disorder
Objective: Describe the development and psychometric validation of a brief scale (the Sleep Condition Indicator (SCI)) to evaluate insomnia disorder in everyday clinical practice.<p></p>
Design: The SCI was evaluated across five study samples. Content validity, internal consistency and concurrent validity were investigated.<p></p>
Participants: 30 941 individuals (71% female) completed the SCI along with other descriptive demographic and clinical information.<p></p>
Setting: Data acquired on dedicated websites.<p></p>
Results: The eight-item SCI (concerns about getting to sleep, remaining asleep, sleep quality, daytime personal functioning, daytime performance, duration of sleep problem, nights per week having a sleep problem and extent troubled by poor sleep) had robust internal consistency (α≥0.86) and showed convergent validity with the Pittsburgh Sleep Quality Index and Insomnia Severity Index. A two-item short-form (SCI-02: nights per week having a sleep problem, extent troubled by poor sleep), derived using linear regression modelling, correlated strongly with the SCI total score (r=0.90).<p></p>
Conclusions: The SCI has potential as a clinical screening tool for appraising insomnia symptoms against Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria.<p></p>
Status of Rockwell-ERC high efficiency solar cell programs
Programs aimed at developing large area, high efficiency GaAs heteroface cells for low concentration space applications and high concentration terrestrial applications as well as other programs aimed at developing high efficiency multicolor devices for use in similar applications are described. An additional program aimed at achieving improved power to weight ratio by parting thin film solar cells from their growth substrates prior to their incorporation into an array assembly is also described. There is potential for multiple reuse of the substrates which could lead to reduced costs for such devices. Highlights of these programs and their interrelated contributions toward the goals of reducing specific weight, volume and cost of photovoltaic space power systems are discussed. Overall goals are summarized and current programs and their funding sources are listed
Dihomotopic Deadlock Detection Via Progress Shell Decomposition
The classical problem of deadlock detection for concurrent programs has traditionally been accomplished by symbolic methods or by search of a state transition system. This work examines an approach that uses geometric semantics involving the topological notion of dihomotopy to partition the state space into components, followed by search of a reduced state space. Prior work partitioned the state-space inductively. in this work, a decomposition technique motivated by recursion coupled with a search guided by the decomposition is shown to effectively reduce the size of state transition systems. the reduced state space yields asymptotic improvement in overall runtime for verification. a prototype implementation of this method is introduced here, including a description of its theoretical foundation and its performance benchmarked against the SPIN model checker. © 2010 IEEE
Survey of Infections Transmissible Between Baboons and Humans, Cape Town, South Africa
Baboons on South Africa’s Cape Peninsula come in frequent contact with humans. To determine potential health risks for both species, we screened 27 baboons from 5 troops for 10 infections. Most (56%) baboons had antibodies reactive or cross-reactive to human viruses. Spatial overlap between these species poses low but potential health risks
Experimental field estimation of organic nitrogen formation in tree canopies
The content of organic N has been shown in many studies to increase during the passage of rain water through forest canopies. The source of this organic N is unknown, but generally assumed to come from canopy processing of wet or dry-deposited inorganic N. There have been very few experimental studies in the field to address the canopy formation or loss of organic N. We report two studies: a Scots pine canopy exposed to ammonia gas, and a Sitka spruce canopy exposed to ammonium and nitrate as wet deposition. In both cases, organic N deposition in throughfall was increased, but only represented a small fraction (<10%) of the additional inorganic N supplied, suggesting a limited capacity for net organic N production, similar in both conifer canopies under Scottish summertime conditions, of less than 1.6 mmol Nm2 mth1 (equivalent to 3 kg N ha1 y1)
Broadband Adoption in Illinois
This research paper discusses broadband demographic factors which may affect adoption in Illinois. Primary data was collected by the PEW Internet & American Life Project, which has made multiple data sets available for public use. Calculations were conducted to specifically analyze Illinois broadband adoption by demographic variables of income, ethnicity/race, education, gender, and age.
Analysis confirmed previous studies showing similar demographic factors affecting adoption of broadband apply to Illinois. The most prevalent factor in determining adoption is education. This study shows 90% of Illinois residents who have a college degree or higher adopts broadband. Income results are in line with previous studies in which households with earnings of 40,000 are significant as a predictor of non-adoption, and 64% are non-adopters. Gender was determined to be a predictor of broadband adoption which was not in line with other studies
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Dynamic interpersonal therapy for moderate to severe depression: A pilot randomized controlled and feasibility trial
Background: Improving Access to Psychological Therapies (IAPT) services treat most patients in England who present to primary care with major depression. Psychodynamic psychotherapy is one of the psychotherapies offered. Dynamic Interpersonal Therapy (DIT) is a psychodynamic and mentalization-based treatment for depression. 16 sessions are delivered over approximately 5 months. Neither DIT's effectiveness relative to low-intensity treatment (LIT), nor the feasibility of randomizing patients to psychodynamic or cognitive-behavioural treatments (CBT) in an IAPT setting has been demonstrated.
Methods: 147 patients were randomized in a 3:2:1 ratio to DIT (n = 73), LIT (control intervention; n = 54) or CBT (n = 20) in four IAPT treatment services in a combined superiority and feasibility design. Patients meeting criteria for major depressive disorder were assessed at baseline, mid-treatment (3 months) and post-treatment (6 months) using the Hamilton Rating Scale for Depression (HRSD-17), Beck Depression Inventory-II (BDI-II) and other self-rated questionnaire measures. Patients receiving DIT were also followed up 6 months post-completion.
Results: The DIT arm showed significantly lower HRSD-17 scores at the 6-month primary end-point compared with LIT (d = 0.70). Significantly more DIT patients (51%) showed clinically significant change on the HRSD-17 compared with LIT (9%). The DIT and CBT arms showed equivalence on most outcomes. Results were similar with the BDI-II. DIT showed benefit across a range of secondary outcomes.ConclusionsDIT delivered in a primary care setting is superior to LIT and can be appropriately compared with CBT in future RCTs
Evaluation of the pathways of tropospheric nitrophenol formation using a multiphase model
International audiencePhenols are a major class of volatile organic compounds (VOC) whose reaction within, and partitioning between, the gas and liquid phases affects their lifetime within the atmosphere, the local oxidising capacity, and the extent of production of nitrophenols, which are toxic chemicals. In this work, a zero-dimension box model was constructed to quantify the relative nitration pathways, and partitioning into the liquid phase, of mono-aromatic compounds in order to help elucidate the formation pathways of 2- and 4-nitrophenol in the troposphere. The liquid phase contributed significantly to the production of nitrophenols for liquid water content (Lc) values exceeding 3×10-9, and for a range of assumed liquid droplet diameter, even though the resultant equilibrium partitioning to the liquid phase was much lower. For example, in a ''typical'' model scenario, with Lc=3×10-7, 58% of nitrophenol production occurred in the liquid phase but only 2% of nitrophenol remained there, i.e. a significant proportion of nitrophenol observed in the gas phase may actually be produced via the liquid phase. The importance of the liquid phase was enhanced at lower temperatures, by a factor ~1.5?2 at 278 K cf. 298 K. The model showed that nitrophenol production was particularly sensitive to the values of the rate coefficients for the liquid phase reactions between phenol and OH or NO3 reactions, but insensitive to the rate coefficient for the reaction between benzene and OH, thus identifying where further experimental data are required
Recursive Decomposition of Progress Graphs
Search of a state transition system is traditionally how deadlock detection for concurrent programs has been accomplished. This paper examines an approach to deadlock detection that uses geometric semantics involving the topo-logical notion of dihomotopy to partition the state space into components; after that the reduced state space is exhaustively searched. Prior work partitioned the state space inductively. in this paper we show that a recursive technique provides greater reduction of the size of the state transition system and therefore more efficient deadlock detection. If the preprocessing can be done efficiently, then for large problems we expect to see more efficient deadlock detection and eventually more efficient verification of some temporal properties. © 2009 IEEE
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