Energy levels and magneto-optical transitions in parabolic quantum dots with spin-orbit coupling

We report on the electronic properties of few interacting electrons confined in a parabolic quantum dot based on a theoretical approach developed to investigate the influence of Bychkov-Rashba spin-orbit (SO) interaction on such a system. We note that the spin-orbit coupling profoundly influences the energy spectrum of interacting electrons in a quantum dot. Here we present accurate results for the energy levels and optical-absorption spectra for parabolic quantum dots containing upto four interacting electrons, in the presence of spin-orbit coupling and under the influence of an externally applied, perpendicular magnetic field. We have described in detail about a very accurate numerical scheme to evaluate these quantities. We have evaluated the effects of SO coupling on the Fock-Darwin spectra for quantum dots made out of three different semiconductor systems, InAs, InSb, and GaAs.Comment: expanded version of cond-mat/0501642 to be published in Phys. Rev. Let

Perioperative safety of two-team simultaneous bilateral total knee arthroplasty in the obese patient

<p>Abstract</p> <p>Background</p> <p>Although the rates of perioperative morbidity and mortality with simultaneous bilateral total knee arthroplasty remain a concern, multiple studies have shown the procedure to be safe in selected patient populations. Evidence also remains mixed regarding the outcomes of total knee arthroplasty in obese patients. The purpose of this paper is to compare the rates of perioperative morbidity and mortality in consecutive obese patients undergoing two-team simultaneous bilateral total knee arthroplasty and unilateral total knee arthroplasty.</p> <p>Methods</p> <p>The records on all two-team simultaneous total knee arthroplasties and unilateral total knee arthroplasties from October 1997 to December 2007 were reviewed. A total of 151 patients with a body mass index (BMI) >30 undergoing two-team simultaneous total knee arthroplasty and 148 patients with a BMI >30 undergoing unilateral total knee arthroplasty were retrospectively reviewed and analyzed to determine perioperative morbidity and mortality as well as one-year mortality rates.</p> <p>Results</p> <p>Preoperative patient characteristics did not show any significant differences between groups. The simultaneous bilateral group had significantly longer operative times (127.4 versus 112.7 minutes, p < 0.01), estimated blood loss (176.7 versus 111.6 mL, p = 0.01), percentage of patients requiring blood transfusion (64.9% versus 13.9%, p < 0.01), length of hospital stay (3.72 versus 3.30 days, p < 0.01), and percentage of patients requiring extended care facility usage at discharge (63.6% versus 27.8%, p < 0.01). No significant difference between unilateral and bilateral groups was seen in regards to total complication rate, major or minor complication subgroup rate, or any particular complication noted. Doubling the variables in the unilateral group for a staged total knee arthroplasty scenario did create significant increases over the simultaneous data in almost every data category.</p> <p>Conclusions</p> <p>Two-team simultaneous total knee arthroplasty appears to be safe in obese patients, with similar complication rates as compared to unilateral procedures. Two-team simultaneous total knee arthroplasty also appears to have potential benefits over a staged procedure in the obese patient, although more study is required regarding this topic.</p

An active registry for bioinformatics web services

Summary: The EMBRACE Registry is a web portal that collects and monitors web services according to test scripts provided by the their administrators. Users are able to search for, rank and annotate services, enabling them to select the most appropriate working service for inclusion in their bioinformatics analysis tasks

The Importance of Context in Understanding Homelessness and Mental Illness: Lessons Learned From a Research Demonstration Project

Research reports on the housing outcomes for persons who are homeless and mentally ill have focused on client characteristics, program type, and services as independent variables, with mixed results. From social work practice, evaluation theory, and public policy perspectives, context is an important variable. Yet, it has received scant research attention in studies of the outcomes of persons who are mentally ill and homeless. This article summarizes research results from a demonstration project providing outreach or linkage services to this target population, illustrating the significant impact of context variables (site and recruitment source) on client characteristics, implementation, qualitative and quantitative service assessments, and housing outcomes. The discussion suggests how these contextual factors may operate, and it goes on to make recommendations to improve social work research and practice concerning the important dimensions of context that should be assessed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69136/2/10.1177_104973159800800203.pd

Channeling of charge carrier plasmons in carbon nanotubes

Ab initio calculations of the loss function of potassium-intercalated and electron-loaded bundles of single-walled carbon nanotubes yield a channeled-charge-carrier plasmon without perpendicular dispersion. Experimentally, we probe the momentum-dependent loss function of thin bundles consisting of only a few potassium-intercalated single-walled carbon nanotubes by angle-resolved electron-energy-loss spectroscopy and confirm this intrinsic channeling. The charge-carrier-plasmon energy is via in situ intercalation and is tunable in the near-visible infrared-energy range from 0.85 to 1.15 eV

Raising our sites: Dissemination of supported education

In order to promote replication of supported education, an exemplary rehabilitation model for adults with psychiatric disabilities, funds were accessed through a Community Action Grant from the Center for Mental Health Services of the Substance Abuse and Mental Health Services Administration. Three communities in Michigan participated in a multistage process designed to maximize community ownership by encouraging local adaptations involving all stakeholder groups and providing technical assistance. The stages in the process were organizing the community for supported education development, acquiring knowledge about supported education basics, collecting information (needs assessment and barrier identification), and developing the plan. All three sites have begun implementation, providing services to adults with psychiatric disabilities who wish to pursue post-secondary education. The approach employed has applicability for other local communities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45773/1/11414_2005_Article_BF02287778.pd

Critical Ingredients of Consumer Run Services: Results of a National Survey

Fidelity criteria are increasingly used in program monitoring and evaluation, but are difficult to derive for emerging models (i.e., those not based on theory or a research demonstration project). We describe steps used to develop and operationalize fidelity criteria for consumer-run (CR) mental health services: articulating and operationalizing criteria based on published literature, then revising and validating the criteria through expert judgments using a modified Delphi method. Respondents rated highest those structural and process components emphasizing the value of consumerism: consumer control, consumer choices and opportunities for decision-making, voluntary participation (and the absence of coercion), and respect for members by staff.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44316/1/10597_2004_Article_480623.pd

Transform-domain analysis of packet delay in network nodes with QoS-aware scheduling

In order to differentiate the perceived QoS between traffic classes in heterogeneous packet networks, equipment discriminates incoming packets based on their class, particularly in the way queued packets are scheduled for further transmission. We review a common stochastic modelling framework in which scheduling mechanisms can be evaluated, especially with regard to the resulting per-class delay distribution. For this, a discrete-time single-server queue is considered with two classes of packet arrivals, either delay-sensitive (1) or delay-tolerant (2). The steady-state analysis relies on the use of well-chosen supplementary variables and is mainly done in the transform domain. Secondly, we propose and analyse a new type of scheduling mechanism that allows precise control over the amount of delay differentiation between the classes. The idea is to introduce N reserved places in the queue, intended for future arrivals of class 1