2,190 research outputs found
Preventing incident infections in long-term partnerships: a role for microbicides [Rapid response]
Antiferromagnetic order and dielectric gap within the vortex core of antiferromagnetic superconductor
The structure of a superconducting vortex has been studied theoretically for
a dirty antiferromagnetic superconductor (AFSC), modelling an AFSC as a doped
semi-metal with s-wave superconducting pairing and antiferromagnetic
(dielectric) interaction between electrons (holes). It is also supposed that
the quasiparticles dispersion law possesses the property of nesting. The
distribution of the superconducting and magnetic order parameters near the
vortex core is calculated. It is shown that the antiferromagnetic order, been
suppressed at large distances, is restored around the superconducting flux and
the vortex core is in fact insulating and antiferromagnetic, in stark contrast
to the normal metal cores of traditional superconductors. Moreover, our model
calculations predict that as the temperature decreases the flux region of the
superconductivity and antiferromagnetism coexistence increases.Comment: 9 pages, 3 Postscript figures,NATO Advanced Research Workshop on
"Vortex dynamics in superconductors and other complex systems" Yalta, Crimea,
Ukraine, 13-17 September 200
ESHAP and G-CSF is a superior blood stem cell mobilizing regimen compared to cyclophosphamide 1.5 g m−2 and G-CSF for pre-treated lymphoma patients: a matched pairs analysis of 78 patients
Cyclophosphamide 1.5 g m−2followed by granulocyte colony-stimulating factor (G-CSF) is an effective peripheral blood stem cell (PBSC) mobilizing regimen, but has limited anti-lymphoma activity. We therefore assessed the mobilizing potential of ESHAP (etoposide, ara-C, methylprednisolone and cisplatin), a potent second-line lymphoma regimen followed by G-CSF. The results were compared in 78 patients with relapsed or resistant lymphomas with the use of cyclophosphamide 1.5 g m−2followed by G-CSF in a matched pairs analysis, matching the ESHAP recipients (for predetermined prognostic factors) from a cohort of 178 lymphoma patients mobilized with cyclophosphamide and G-CSF. The total numbers of mononuclear cells collected at apheresis was similar with both regimens but ESHAP plus G-CSF resulted in a significantly higher percentage of CD34+ cells, absolute number of CD34+ cells and GM-CFC (all with P -values < 0.001). The number of patients requiring only one apheresis harvest to achieve a CD34+ cell yield of > 2.0 × 106kg−1was greatly increased in the ESHAP recipients (56/78 vs 17/78, P< 0.001). The total number of progenitor cells collected was not significantly different with the two mobilization regimens because of this higher number of apheresis in the cyclophosphamide group. The proportion of patients who failed to achieve a minimum CD34+ cell target of 1 × 106kg−1with the pooled harvests was less in the ESHAP arm (four patients vs nine patients) despite an increased number of aphereses in the cyclophosphamide recipients. ESHAP plus G-CSF is well tolerated and is an excellent mobilization regimen in patients with pre treated lymphoma. © 2000 Cancer Research Campaig
Network community cluster-based analysis for the identification of potential leukemia drug targets
Leukemia is a hematologic cancer which develops in blood tissue and causes rapid generation of immature and abnormal-shaped white blood cells. It is one of the most prominent causes of death in both men and women for which there is currently not an effective treatment. For this reason, several therapeutical strategies to determine potentially relevant genetic factors are currently under development, as targeted therapies promise to be both more effective and less toxic than current chemotherapy. In this paper, we present a network community cluster-based analysis for the identification of potential gene drug targets for acute lymphoblastic leukemia and acute myeloid leukemia.Peer ReviewedPostprint (author's final draft
Universality of the Crossing Probability for the Potts Model for q=1,2,3,4
The universality of the crossing probability of a system to
percolate only in the horizontal direction, was investigated numerically by
using a cluster Monte-Carlo algorithm for the -state Potts model for
and for percolation . We check the percolation through
Fortuin-Kasteleyn clusters near the critical point on the square lattice by
using representation of the Potts model as the correlated site-bond percolation
model. It was shown that probability of a system to percolate only in the
horizontal direction has universal form for
as a function of the scaling variable . Here,
is the probability of a bond to be closed, is the
nonuniversal crossing amplitude, is the nonuniversal metric factor,
is the nonuniversal scaling index, is the correlation
length index.
The universal function . Nonuniversal scaling factors
were found numerically.Comment: 15 pages, 3 figures, revtex4b, (minor errors in text fixed,
journal-ref added
Using data from 'visible' populations to estimate the size and importance of 'hidden' populations in an epidemic: A modelling technique.
We used reported behavioural data from cisgender men who have sex with men and transgender women (MSM/TGW) in Bangalore, mainly collected from 'hot-spot' locations that attract MSM/TGW, to illustrate a technique to deal with potential issues with the representativeness of this sample. A deterministic dynamic model of HIV transmission was developed, incorporating three subgroups of MSM/TGW, grouped according to their reported predominant sexual role (insertive, receptive or versatile). Using mathematical modelling and data triangulation for 'balancing' numbers of partners and role preferences, we compared three different approaches to determine if our technique could be useful for inferring characteristics of a more 'hidden' insertive MSM subpopulation, and explored their potential importance for the HIV epidemic. Projections for 2009 across all three approaches suggest that HIV prevalence among insertive MSM was likely to be less than half that recorded in the surveys (4.5-6.5% versus 13.1%), but that the relative size of this subgroup was over four times larger (61-69% of all MSM/TGW versus 15%). We infer that the insertive MSM accounted for 10-20% of all prevalent HIV infections among urban males aged 15-49. Mathematical modelling can be used with data on 'visible' MSM/TGW to provide insights into the characteristics of 'hidden' MSM. A greater understanding of the sexual behaviour of all MSM/TGW is important for effective HIV programming. More broadly, a hidden subgroup with a lower infectious disease prevalence than more visible subgroups, has the potential to contain more infections, if the hidden subgroup is considerably larger in size
Quantification of the performance of chaotic micromixers on the basis of finite time Lyapunov exponents
Chaotic micromixers such as the staggered herringbone mixer developed by
Stroock et al. allow efficient mixing of fluids even at low Reynolds number by
repeated stretching and folding of the fluid interfaces. The ability of the
fluid to mix well depends on the rate at which "chaotic advection" occurs in
the mixer. An optimization of mixer geometries is a non trivial task which is
often performed by time consuming and expensive trial and error experiments. In
this paper an algorithm is presented that applies the concept of finite-time
Lyapunov exponents to obtain a quantitative measure of the chaotic advection of
the flow and hence the performance of micromixers. By performing lattice
Boltzmann simulations of the flow inside a mixer geometry, introducing massless
and non-interacting tracer particles and following their trajectories the
finite time Lyapunov exponents can be calculated. The applicability of the
method is demonstrated by a comparison of the improved geometrical structure of
the staggered herringbone mixer with available literature data.Comment: 9 pages, 8 figure
A Simple Iterative Model Accurately Captures Complex Trapline Formation by Bumblebees Across Spatial Scales and Flower Arrangements
PMCID: PMC3591286This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Improving corporate governance in state-owned corporations in China: which way forward?
This article discusses corporate governance in China. It outlines the basic agency problem in Chinese listed companies and questions the effectiveness of the current mechanisms employed to improve their standards of governance. Importantly, it considers alternative means through which corporate practice in China can be brought into line with international expectations and stresses the urgency with which this task must be tackled. It concludes that regulators in China must construct a corporate governance model which is compatible with its domestic setting and not rush to adopt governance initiatives modelled on those in cultures which are fundamentally different in the hope of also reproducing their success
Effectiveness of bisphosphonates on nonvertebral and hip fractures in the first year of therapy: The risedronate and alendronate (REAL) cohort study
INTRODUCTION: Randomized clinical trials have shown that risedronate and alendronate reduce fractures among women with osteoporosis. The aim of this observational study was to observe, in clinical practice, the incidence of hip and nonvertebral fractures among women in the year following initiation of once-a-week dosing of either risedronate or alendronate. METHODS: Using records of health service utilization from July 2002 through September 2004, we created two cohorts: women (ages 65 and over) receiving risedronate (n = 12,215) or alendronate (n = 21,615). Cox proportional hazard modeling was used to compare the annual incidence of nonvertebral fractures and of hip fractures between cohorts, adjusting for potential differences in risk factors for fractures. RESULTS: There were 507 nonvertebral fractures and 109 hip fractures. Through one year of therapy, the incidence of nonvertebral fractures in the risedronate cohort (2.0%) was 18% lower (95% CI 2% – 32%) than in the alendronate cohort (2.3%). The incidence of hip fractures in the risedronate cohort (0.4%) was 43% lower (95% CI 13% – 63%) than in the alendronate cohort (0.6%). These results were consistent across a number of sensitivity analyses. CONCLUSION: Patients receiving risedronate have lower rates of hip and nonvertebral fractures during their first year of therapy than patients receiving alendronate
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