4,385 research outputs found
Spin-dependent pump current and noise in an adiabatic quantum pump based on domain walls in a magnetic nanowire
We study the pump current and noise properties in an adiabatically modulated
magnetic nanowire with double domain walls (DW). The modulation is brought
about by applying a slowly oscillating magnetic and electric fields with a
controllable phase difference. The pumping mechanism resembles the case of the
quantum dot pump with two-oscillating gates. The pump current, shot noise, and
heat flow show peaks when the Fermi energy matches with the spin-split resonant
levels localized between the DWs. The peak height of the pump current is an
indicator for the lifetime of the spin-split quasistationary states between the
DWs. For sharp DWs, the energy absorption from the oscillating fields results
in side-band formations observable in the pump current. The pump noise carries
information on the correlation properties between the nonequilibrium electrons
and the quasi-holes created by the oscillating scatterer. The ratio between the
pump shot noise and the heat flow serves as an indicator for quasi-particle
correlation.Comment: 18 pages, 5 figure
Some issues in data model mapping
Numerous data models have been reported in the literature since the early 1970's. They have been used as database interfaces and as conceptual design tools. The mapping between schemas expressed according to the same data model or according to different models is interesting for theoretical and practical purposes. This paper addresses some of the issues involved in such a mapping. Of special interest are the identification of the mapping parameters and some current approaches for handling the various situations that require a mapping
Does land use and landscape contribute to self-harm? A sustainability cities framework
Self-harm has become one of the leading causes of mortality in developed countries.
The overall rate for suicide in Canada is 11.3 per 100,000 according to Statistics Canada in 2015.
Between 2000 and 2007 the lowest rates of suicide in Canada were in Ontario, one of the most
urbanized regions in Canada. However, the interaction between land use, landscape and self-harm
has not been significantly studied for urban cores. It is thus of relevance to understand the impacts of
land-use and landscape on suicidal behavior. This paper takes a spatial analytical approach to assess
the occurrence of self-harm along one of the densest urban cores in the country: Toronto. Individual
self-harm data was gathered by the National Ambulatory Care System (NACRS) and geocoded into
census tract divisions. Toronto’s urban landscape is quantified at spatial level through the calculation
of its land use at di erent levels: (i) land use type, (ii) sprawl metrics relating to (a) dispersion and
(b) sprawl/mix incidence; (iii) fragmentation metrics of (a) urban fragmentation and (b) density and
(iv) demographics of (a) income and (b) age. A stepwise regression is built to understand the most
influential factors leading to self-harm from this selection generating an explanatory model.This research was supported by the Canadian Institutes of
Health Research Strategic Team Grant in Applied Injury Research # TIR-103946 and the Ontario Neurotrauma
Foundation grantinfo:eu-repo/semantics/publishedVersio
Drell-Yan production and Lam-Tung relation in the Color Glass Condensate formalism
We study the Drell-Yan production cross section and structure functions in
proton (deuteron)-nucleus collisions using the Color Glass Condensate
formalism. The nucleus is treated in the Color Glass Condensate framework which
includes both higher twist effects due to the inclusion of multiple scatterings
and leading twist pQCD shadowing due to the small x resummation, while the
proton (or deuteron) is treated within the DGLAP improved parton model. In
particular, the Drell-Yan structure functions are used in order to investigate
the Lam-Tung relation at small x, which is known to be identically zero at
leading twist up to Next-to-Leading order, and is thus a good playground for
studying higher twist effects. In agreement with this, we find that violations
of this relation are more important for low momentum and invariant mass of the
Drell-Yan pair, and also in the region of rapidity that corresponds to smaller
values of x in the nucleus.Comment: 25 pages, 16 postscript figure
Screening for HLA-B*1502 Polymorphism in Febrile Seizure Predicted Lead to Epilepsy
Mutation in neuronal sodium channel -1-subunit gene (SCN1A) and neuronal sodium channel -1-subunit gene (SCN1B) has been linked with forms of generalized epilepsy with febrile seizure plus (GEFS+) and epileptic infantile syndrome like severe myoclonic epilepsy of infancy (SMEI) (Mulley et al., 2005; Scheffer et al., 2007). Since this idiopathic epilepsy typically begins with prolonged febrile seizures (FS) in the first year of life, therefore febrile seizure patient with mutation in SCN1A has a high risk to develop epilepsy on their later life (Dube et al., 2009). Carbamazepine (CBZ) has been known as the most common anti-epileptic drug which can cause Steven-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients with HLA-B*1502 polymorphism. Since the Javanese population have 16,67% of these allele, studying the presence of these allele in patients predicted epilepsy is important.
Furthermore, this study was intended to develop a PCR-based diagnostic protocol to screen HLA-B*1502 polymorphism in epileptic patients to prevent SJS/TEN by carbamazepine. Focusing on epileptic predicted patients, HLA-B*1502 genotyping by sequence specific primer (SSP)-PCR was performed on 31 repeated FS patients with mutation in SCN1A and SCN1A/SCN1B gene.
The result show that the HLA-B*1502 polymorphism was detected in 14 (45,2%) individuals including 8 cases related to mutation SCN1A gene and 6 to SCN1A/SCN1B gene. It illustrates that HLA-B*1502 allele is frequent in these patients. It can thus be suggested that detection of this allele should be done before epilepsy treatment. Later, patients with this allele should avoid CBZ to prevent SJS/TEN during drug administration
Magnetization reversal and spin dynamics exchange in biased F/AF bilayers probed with complex permeability spectra
The spin dynamics of the ferromagnetic pinned layer of
ferro-antiferromagnetic coupled NiFe/MnNi bilayers is investigated in a broad
frequency range (30 MHz-6 GHz). A phenomenological model based on the
Landau-Lifshitz equation for the complex permeability of the F/AF bilayer is
proposed. The experimental results are compared to theoretical predictions. We
show that the resonance frequencies, measured during the magnetization, are
likewise hysteretic.Comment: 4 pages, 4 figure
Constraints on stable equilibria with fluctuation-induced forces
We examine whether fluctuation-induced forces can lead to stable levitation.
First, we analyze a collection of classical objects at finite temperature that
contain fixed and mobile charges, and show that any arrangement in space is
unstable to small perturbations in position. This extends Earnshaw's theorem
for electrostatics by including thermal fluctuations of internal charges.
Quantum fluctuations of the electromagnetic field are responsible for
Casimir/van der Waals interactions. Neglecting permeabilities, we find that any
equilibrium position of items subject to such forces is also unstable if the
permittivities of all objects are higher or lower than that of the enveloping
medium; the former being the generic case for ordinary materials in vacuum.Comment: 4 pages, 1 figur
Allosteric modulation of beta1 integrin function induces lung repair in animal model of emphysema.
Emphysema is a progressive lung disease characterised by loss of lung parenchyma with associated functional changes including decreased tissue elastance. Here we report beta1 integrin is a novel target for tissue repair and regeneration in emphysema. We show a single dose of a monoclonal antibody against beta1 integrin induced both functional and structural reversal of elastase-induced lung injury in vivo, and we found that similar matrix remodelling changes occurred in human lung tissue. We also identified a potential mechanism of action as this allosteric modulation of beta1 integrin inhibited elastase-induced caspase activation, F-actin aggregate formation and changes in cellular ATP levels. This was accompanied by maintenance of beta1?integrin levels and inhibition of caveolin-1 phosphorylation. We propose that allosteric modulation of beta1 integrin-mediated mechanosensing prevents cell death associated with lung injury and progressive emphysema, thus allowing cells to survive and for repair and regeneration to ensue
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