246 research outputs found
Length scales, collective modes, and type-1.5 regimes in three-band superconductors
The recent discovery of iron pnictide superconductors has resulted in a
rapidly growing interest in multiband models with more than two bands. In this
work we specifically focus on the properties of three-band Ginzburg-Landau
models which do not have direct counterparts in more studied two-band models.
First we derive normal modes and characteristic length scales in the
conventional U(1) three-band Ginzburg-Landau model as well as in its time
reversal symmetry broken counterpart with symmetry. We show
that in the latter case, the normal modes are mixed phase/density collective
excitations. A possibility of the appearance of a massless phase-difference
mode associated with fluctuations of the phase difference is also discussed.
Next we show that gradients of densities and phase differences can be
inextricably intertwined in vortex excitations in three-band models. This can
lead to very long-range attractive intervortex interactions and appearance of
type-1.5 regimes even when the intercomponent Josephson coupling is large. In
some cases it also results in the formation of a domain-like structures in the
form of a ring of suppressed density around a vortex across which one of the
phases shifts by . We also show that field-induced vortices can lead to a
change of broken symmetry from U(1) to in the system. In the
type-1.5 regime, it results in a semi-Meissner state where the system has a
macroscopic phase separation in domains with broken U(1) and
symmetries.Comment: Version 3: Corrected som inconstancies in the parameter set in Fig.2
Also som minor typos corrected. No changes to results or conclusion
Semi-Meissner state and non-pairwise intervortex interactions in type-1.5 superconductors
We demonstrate existence of non-pairwise interaction forces between vortices
in multicomponent and layered superconducting systems. That is, in contrast to
most common models, the interactions in a group of such vortices is not a
universal superposition of Coulomb or Yukawa forces. Next we consider the
properties of vortex clusters in Semi-Meissner state of type-1.5 two-component
superconductors. We show that under certain condition non-pairwise forces can
contribute to formation of very complex vortex states in type-1.5 regimes.Comment: v2: replaced with version to appear in Phys.Rev. B. Substantially
exteded, title changed. Animation of the vortex clusters formation in
type-1.5 superconductors is available at
http://people.umass.edu/garaud/NonPairwise.htm
Venous thrombosis in immunocompetent patients with acute cytomegalovirus infection: a complication that may be underestimated
In the present study, we retrospectively studied clinical and laboratory findings associated with cytomegalovirus (CMV) infection in immunocompetent patients. We focused on severe CMV infection. Among 38 patients, five had a severe form of infection: one had meningitis, one had symptomatic thrombocytopenia and three had venous thromboses with pulmonary embolism, a rarely described complication. CMV-induced thrombosis has been reported in immunocompromised patients such as transplant recipients and patients with AIDS. Recent case reports have also described thrombotic phenomena in immunocompetent patients with CMV infection. Our study suggests that venous thrombosis during acute CMV infection is an underestimated complication
Don’t forget the porpoise: acoustic monitoring reveals fine scale temporal variation between bottlenose dolphin and harbour porpoise in Cardigan Bay SAC
Populations of bottlenose dolphin and harbour porpoise inhabit Cardigan Bay, which was designated a Special Area of Conservation (SAC), with bottlenose dolphin listed as a primary feature for its conservation status. Understanding the abundance, distribution and habitat use of species is fundamental for conservation and the implementation of management. Bottlenose dolphin and harbour porpoise usage of feeding sites within Cardigan Bay SAC was examined using passive acoustic monitoring. Acoustic detections recorded with calibrated T-PODs (acoustic data loggers) indicated harbour porpoise to be present year round and in greater relative abundance than bottlenose dolphin. Fine-scale temporal partitioning between the species occurred at three levels: (1) seasonal differences, consistent between years, with porpoise detections peaking in winter months and dolphin detections in summer months; (2) diel variation, consistent across sites, seasons and years, with porpoise detections highest at night and dolphin detections highest shortly after sunrise; and (3) tidal variation was observed with peak dolphin detections occurring during ebb at the middle of the tidal cycle and before low tide, whereas harbour porpoise detections were highest at slack water, during and after high water with a secondary peak recorded during and after low water. General Additive Models (GAMs) were applied to better understand the effects of each covariate. The reported abundance and distribution of the two species, along with the temporal variation observed, have implications for the design and management of protected areas. Currently, in the UK, no SACs have been formally designated for harbour porpoise while three exist for bottlenose dolphins. Here, we demonstrate a need for increased protection and species-specific mitigation measures for harbour porpoise
The Autism - Tics, AD/HD and other Comorbidities inventory (A-TAC): further validation of a telephone interview for epidemiological research
<p>Abstract</p> <p>Background</p> <p>Reliable, valid, and easy-to-administer instruments to identify possible caseness and to provide proxies for clinical diagnoses are needed in epidemiological research on child and adolescent mental health.</p> <p>The aim of this study is to provide further validity data for a parent telephone interview focused on Autism - Tics, Attention-deficit/hyperactivity disorder (AD/HD), and other Comorbidities (A-TAC), for which reliability and preliminary validation data have been previously reported.</p> <p>Methods</p> <p>Parents of 91 children clinically diagnosed at a specialized Child Neuropsychiatric Clinic, 366 control children and 319 children for whom clinical diagnoses had been previously assigned were interviewed by the A-TAC over the phone. Interviewers were blind to clinical information. Different scores from the A-TAC were compared to the diagnostic outcome.</p> <p>Results</p> <p>Areas under ROC curves for interview scores as predictors of clinical diagnoses were around 0.95 for most disorders, including autism spectrum disorders (ASDs), attention deficit/hyperactivity disorder (AD/HD), tic disorders, developmental coordination disorders (DCD) and learning disorders, indicating excellent screening properties. Screening cut-off scores with sensitivities above 0.90 (0.95 for ASD and AD/HD) were established for most conditions, as well as cut-off scores to identify proxies to clinical diagnoses with specificities above 0.90 (0.95 for ASD and AD/HD).</p> <p>Conclusions</p> <p>The previously reported validity of the A-TAC was supported by this larger replication study using broader scales from the A-TAC-items and a larger number of diagnostic categories. Short versions of algorithms worked as well as larger. Different cut-off levels for screening versus identifying proxies for clinical diagnoses are warranted. Data on the validity for mood problems and oppositional defiant/conduct problems are still lacking. Although the A-TAC is principally intended for epidemiological research and general investigations, the instrument may be useful as a tool to collect information in clinical practice as well.</p
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Person-centred care in interventions to limit weight gain in pregnant women with obesity - a systematic review
Background
Person-centred care, asserting that individuals are partners in their care, has been associated with care satisfaction but the value of using it to support women with obesity during pregnancy is unknown. Excessive gestational weight gain is associated with increased risks for both mother and baby and weight gain therefore is an important intervention target. The aims of this review was to 1) explore to what extent and in what manner interventions assessing weight in pregnant women with obesity use person-centred care and 2) assess if interventions including aspects of person-centred care are more effective at limiting weight gain than interventions not employing person-centred care.
Methods
Ten databases were systematically searched in January 2014. Studies had to report an intervention offered to pregnant women with obesity and measure gestational weight gain to be included. All included studies were independently double coded to identify to what extent they included three defined aspects of person-centred care: 1) “initiate a partnership” including identifying the person’s circumstances and motivation; 2) “working the partnership” through sharing the decision-making regarding the planned action and 3) “safeguarding the partnership through documentation” of care preferences. Information on gestational weight gain, study quality and characteristics were also extracted.
Results
Ten studies were included in the review, of which five were randomised controlled trials (RCT), and the remaining observational studies. Four interventions included aspects of person-centred care; two observational studies included both “initiating the partnership”, and “working the partnership”. One observational study included “initiating the partnership” and one RCT included “working the partnership”. No interventions included “safeguarding the partnership through documentation”. Whilst all studies with person-centred care aspects showed promising findings regarding limiting gestational weight gain, so did the interventions not including person-centred care aspects.
Conclusions
The use of an identified person-centred care approach is presently limited in interventions targeting gestational weight gain in pregnant women with obesity. Hence to what extent person-centred care may improve health outcomes and care satisfaction in this population is currently unknown and more research is needed. That said, our findings suggest that use of routines incorporating person-centredness are feasible to include within these interventions
Attempting to Compensate for Reduced Neuronal Nitric Oxide Synthase Protein with Nitrate Supplementation Cannot Overcome Metabolic Dysfunction but Rather Has Detrimental Effects in Dystrophin-Deficient mdx Muscle
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