4,593 research outputs found
Critical Current Peaks at in Superconductors with Columnar Defects: Recrystalizing the Interstitial Glass
The role of commensurability and the interplay of correlated disorder and
interactions on vortex dynamics in the presence of columnar pins is studied via
molecular dynamics simulations. Simulations of dynamics reveal substantial
caging effects and a non-monotonic dependence of the critical current with
enhancements near integer values of the matching field and
in agreement with experiments on the cuprates. We find qualitative
differences in the phase diagram for small and large values of the matching
field.Comment: 5 pages, 4 figures (3 color
Epigenetic approaches in the treatment of myelodysplastic syndromes: clinical utility of azacitidine
Myelodysplastic syndromes (MDS) are a varied group of diseases leading to significant morbidity and mortality. Therapy of MDS has been difficult, with supportive cares used to ameliorate symptoms, and hematopoietic stem cell transplantation the only curative option. Agents, such as the cytidine analog azacitidine, exert an effect on DNA methyltransferase leading to a reduction in DNA methylation, a process thought to be key to the pathogenesis of MDS. Recently, azacitidine has been shown to prolong survival and improve quality of life in patients with MDS, while maintaining a favorable adverse effect profile. This review highlights the scientific rationale for the use of azacitidine in addition to its application in current clinical practice for patients with MDS
Duration judgements in patients with schizophrenia
Background. The ability to encode time cues underlies many cognitive processes. In the light of schizophrenic patients' compromised cognitive abilities in a variety of domains, it is noteworthy that there are numerous reports of these patients displaying impaired timing abilities. However, the timing intervals that patients have been evaluated on in prior studies vary considerably in magnitude (e.g. 1 s, 1 min, 1 h etc.).
Method. In order to obviate differences in abilities in chronometric counting and place minimal demands on cognitive processing, we chose tasks that involve making judgements about brief durations of time (<1 s).
Results. On a temporal generalization task, patients were less accurate than controls at recognizing a standard duration. The performance of patients was also significantly different from controls on a temporal bisection task, in which participants categorized durations as short or long. Although time estimation may be closely intertwined with working memory, patients' working memory as measured by the digit span task did not correlate significantly with their performance on the duration judgement tasks. Moreover, lowered intelligence scores could not completely account for the findings.
Conclusions. We take these results to suggest that patients with schizophrenia are less accurate at estimating brief time periods. These deficits may reflect dysfunction of biopsychological timing processes
CHEM2D-OPP: A new linearized gas-phase ozone photochemistry parameterization for high-altitude NWP and climate models
The new CHEM2D-Ozone Photochemistry Parameterization (CHEM2D-OPP) for high-altitude numerical weather prediction (NWP) systems and climate models specifies the net ozone photochemical tendency and its sensitivity to changes in ozone mixing ratio, temperature and overhead ozone column based on calculations from the CHEM2D interactive middle atmospheric photochemical transport model. We evaluate CHEM2D-OPP performance using both short-term (6-day) and long-term (1-year) stratospheric ozone simulations with the prototype high-altitude NOGAPS-ALPHA forecast model. An inter-comparison of NOGAPS-ALPHA 6-day ozone hindcasts for 7 February 2005 with ozone photochemistry parameterizations currently used in operational NWP systems shows that CHEM2D-OPP yields the best overall agreement with both individual Aura Microwave Limb Sounder ozone profile measurements and independent hemispheric (10°–90° N) ozone analysis fields. A 1-year free-running NOGAPS-ALPHA simulation using CHEM2D-OPP produces a realistic seasonal cycle in zonal mean ozone throughout the stratosphere. We find that the combination of a model cold temperature bias at high latitudes in winter and a warm bias in the CHEM2D-OPP temperature climatology can degrade the performance of the linearized ozone photochemistry parameterization over seasonal time scales despite the fact that the parameterized temperature dependence is weak in these regions
Ample consumption period available until use-by dates: a potential, marketing position for store brands
Traditionally store brands in Australia are viewed with suspicion in regard to their quality and are usually purchased because of the "value for money" that they offer. Australian supermarket majors are considering introducing a new suite of store brands in the higher price brackets. The danger of moving upscale however is that these store brands are relinquishing their value for money appeal and will come head to head with the manufactured brands. Store brands will now require some quality dimension to compete. This paper after studying the attitudes and behavioural response of grocery shoppers to use by dates, is proposing that that the promise of "generous" use-by dates as a surrogate for quality, could be considered as a positioning plank to promote store brands as alternatives to manufactured brands. Logit analysis is employed to explain shoppers' perception and response to use-by dates, of products that they regularly buy, and of alternative products which they have never bought before if the use-by dates of their regular items are perceived to be too shor
Cosmological gravitomagnetism and Mach's principle
The spin axes of gyroscopes experimentally define local non-rotating frames.
But what physical cause governs the time-evolution of gyroscope axes? We
consider linear perturbations of Friedmann-Robertson-Walker cosmologies with
k=0. We ask: Will cosmological vorticity perturbations exactly drag the spin
axes of gyroscopes relative to the directions of geodesics to quasars in the
asymptotic unperturbed FRW space? Using Cartan's formalism with local
orthonormal bases we cast the laws of linear cosmological gravitomagnetism into
a form showing the close correspondence with the laws of ordinary magnetism.
Our results, valid for any equation of state for cosmological matter, are: 1)
The dragging of a gyroscope axis by rotational perturbations of matter beyond
the Hubble-dot radius from the gyroscope is exponentially suppressed, where dot
is the derivative with respect to cosmic time. 2) If the perturbation of matter
is a homogeneous rotation inside some radius around a gyroscope, then exact
dragging of the gyroscope axis by the rotational perturbation is reached
exponentially fast as the rotation radius grows beyond the H-dot radius. 3) For
the most general linear cosmological perturbations the time-evolution of all
gyroscope spin axes exactly follow a weighted average of the energy currents of
cosmological matter. The weight function is the same as in Ampere's law except
that the inverse square law is replaced by the Yukawa force with the Hubble-dot
cutoff. Our results demonstrate (in first order perturbation theory for FRW
cosmologies with k = 0) the validity of Mach's hypothesis that axes of local
non-rotating frames precisely follow an average of the motion of cosmic matter.Comment: 18 pages, 1 figure. Comments and references adde
A review of solar and visible light active TiO2 photocatalysis for treating bacteria, cyanotoxins and contaminants of emerging concern
Researchintothedevelopmentofsolarandvisiblelightactivephotocatalystshasbeensignificantlyincreased\ud
inrecentyearsduetoitswiderangeofapplicationsintreatingcontaminantsofemergingconcern(CECs),\ud
endocrine disruptingcompounds(EDCs), bacteriaandcyanotoxins.Solarphotocatalysisisfoundtobehighly\ud
effectiveintreatingawiderangeofCECsfromsourcessuchaspharmaceuticals,steroids,antibiotics,phthalates,\ud
disinfectants,pesticides,fragrances(musk),preservativesandadditives.Similarly,anumberofEDCsincluding\ud
polycyclicaromatichydrocarbons(PAHs),alkylphenols(APs),bisphenolA(BPA),organotins(OTs),volatileor-\ud
ganic compounds(VOCs),naturalandsyntheticestrogenicandandrogenicchemicals,pesticides,andheavy\ud
metalscanberemovedfromcontaminatedwaterbyusingsolarphotocatalysis.Photocatalysiswasalsofound\ud
effectiveintreatingawiderangeofbacteriasuchas Staphylococcusaureus,Bacillussubtilis,Escherichiacoli,\ud
Salmonellatyphi and Micrococcuslylae. Thecurrentreviewalsocomparestheeffectivenessofvariousvisible\ud
lightactivatedTiO2 photocatalystsfortreatingthesepollutants. Dopingorco-dopingofTiO2 usingnitrogen,\ud
nitrogen–silver,sulphur,carbon,copperandalsoincorporation ofgraphenenano-sheetsarediscussed.Theuse\ud
of immobilisedTiO2 for improvingthephotocatalyticactivityisalso presented.Decoratingtitaniaphotocatalyst\ud
withgrapheneoxide(GO)isofparticularinterestduetoGO'sabilitytoincreasethephotocatalyticactivityof\ud
TiO2. TheuseGOtoincreasethephotocatalyticactivityofTiO2 againstmicrocystin-LR(MC-LR)underUV-Aand\ud
solarirciationisdiscussed.TheenhancedphotocatalyticactivityofGO–TiO2 comparedtothecontrolmaterialis\ud
attributedtotheeffectiveinhibitionoftheelectron–holerecombinationbycontrollingtheinterfacialcharge\ud
transferprocess.Itisconcludedthatthereisacriticalneedforfurtherimprovementoftheefficiencyofthese\ud
materialsiftheyaretobeconsideredforbulkindustrialuse
Theorizing Masculinities in Contemporary Britain
This chapter examines two key issues about masculinities in contemporary Britain. First, we examine what the evidence says about the extent to which British masculinities are changing, and how this is manifest in contemporary society. Second, we explore how theoretical understandings of masculinities both shape one’s findings, and evolve in relation to a changing culture. We thus provide a partial history of masculinity theory and contextualise the chapters of this edited volume, in order to advance theoretical and empirical understanding of British masculinities. We argue that far from being a crisis of masculinities, the gendered changes in the social lives of British men are positive and to be welcomed
Patellofemoral contact forces and pressures during intramedullary tibial nailing
Patellofemoral joint forces and pressures
were measured in a cadaver model during
intramedullary nailing of the tibia. A significant
increase in contact pressures was found at the
lateral facet of the patellofemoral articulation
using the medial paratendinous approach (P= 0.01)
and at the medial facet when using the trans-patellar
tendon approach (P = 0.001) to the proximal
tibia. Increased contact pressures at the patellofemoral
joint may result in chondral injury, which
in turn may cause anterior knee pain, a common
complication of tibial nailing
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