110 research outputs found

    Probing Spin-Polarized Currents in the Quantum Hall Regime

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    An experiment to probe spin-polarized currents in the quantum Hall regime is suggested that takes advantage of the large Zeeman-splitting in the paramagnetic diluted magnetic semiconductor zinc manganese selenide (Zn1−x_{1-x}Mnx_xSe). In the proposed experiment spin-polarized electrons are injected by ZnMnSe-contacts into a gallium arsenide (GaAs) two-dimensional electron gas (2DEG) arranged in a Hall bar geometry. We calculated the resulting Hall resistance for this experimental setup within the framework of the Landauer-B\"uttiker formalism. These calculations predict for 100% spininjection through the ZnMnSe-contacts a Hall resistance twice as high as in the case of no spin-polarized injection of charge carriers into a 2DEG for filling factor ν=2\nu=2. We also investigated the influence of the equilibration of the spin-polarized electrons within the 2DEG on the Hall resistance. In addition, in our model we expect no coupling between the contact and the 2DEG for odd filling factors of the 2DEG for 100% spininjection, because of the opposite sign of the g-factors of ZnMnSe and GaAs.Comment: 7 pages, 5 figure

    Urban informality and confinement: toward a relational framework

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    In the 21st century, a growing number of people live ‘informal’ lives within fissures between legality and informality. Concomitantly, power relations are increasingly expressed through devices of confinement. While urban informality and confinement are on the rise often occurring simultaneously, scholars have so far studied them separately. By contrast, this article proposes a new framework for analysing urban informality and confinement relationally. It generates new insights into the role of informality in the (re)production of confinement and, vice versa, the role of confinement in shaping informal practices. While these insights are valuable for urban studies in general, the article charts new lines of research on urban marginality. It also discusses how the six articles included in this special issue signal the heuristic potential of this relational framework by empirically examining distinct urban configurations of ‘confined informalities’ and ‘informal confinements’ across the Global North and the Global South

    Improving Colorectal Cancer Screening Decision Making Processes

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    Introduction: Although shared decision making is recommended for cancer screening, it is not routinely completed in practice because of time constraints. We evaluated a process for improving decision making about colorectal cancer (CRC) screening using mailed decision aids (DA) with follow-up telephone support in primary care practices. Methods: We identified patients aged 50-75 who were not up to date with CRC screening in three primary care practices. DA were distributed via mail with telephone follow-up to eligible patients, and charts were reviewed six months later for CRC screening completion. Results: Among 1,064 eligible patients who received the mailed DA, 513 (48.2%) were reached by phone. During the six months after the intervention, 148/1064 (13.9%) patients were screened for CRC (4.8% underwent FIT, 9.1% underwent colonoscopy). Younger patients (aged 50-54) had higher rates of any screening (32.4%) compared with all other age groups (range 12.8%-19.6%), p=0.026, while Medicaid patients had the lowest rates of screening (4.0%), and insured patients had the highest rates (45.3%), p=0.003. Overall, 113/513 (22.0%) who were reached by phone went on to complete screening within 6 months, compared with 35/551 (6.4%) of patients who were not reached by phone (p Conclusion: A standard process for identifying patients unscreened for CRC and DA distribution via mail with telephone decision support modestly increased CRC screening and is consistent with the goal of providing preference-sensitive care and informed decision making. Improving care processes to include decision support outside of office visits is possible in primary care practices

    A toolbox for a structured risk-based prehabilitation program in major surgical oncology

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    Prehabilitation is a multimodal concept to improve functional capability prior to surgery, so that the patients’ resilience is strengthened to withstand any peri- and postoperative comorbidity. It covers physical activities, nutrition, and psychosocial wellbeing. The literature is heterogeneous in outcomes and definitions. In this scoping review, class 1 and 2 evidence was included to identify seven main aspects of prehabilitation for the treatment pathway: (i) risk assessment, (ii) FITT (frequency, interventions, time, type of exercise) principles of prehabilitation exercise, (iii) outcome measures, (iv) nutrition, (v) patient blood management, (vi) mental wellbeing, and (vii) economic potential. Recommendations include the risk of tumor progression due to delay of surgery. Patients undergoing prehabilitation should perceive risk assessment by structured, quantifiable, and validated tools like Risk Analysis Index, Charlson Comorbidity Index (CCI), American Society of Anesthesiology Score, or Eastern Co-operative Oncology Group scoring. Assessments should be repeated to quantify its effects. The most common types of exercise include breathing exercises and moderate- to high-intensity interval protocols. The program should have a duration of 3–6 weeks with 3–4 exercises per week that take 30–60 min. The 6-Minute Walking Testing is a valid and resource-saving tool to assess changes in aerobic capacity. Long-term assessment should include standardized outcome measurements (overall survival, 90-day survival, Dindo–Clavien/CCI®) to monitor the potential of up to 50% less morbidity. Finally, individual cost-revenue assessment can help assess health economics, confirming the hypothetic saving of 8fortreatmentfor8 for treatment for 1 spent for prehabilitation. These recommendations should serve as a toolbox to generate hypotheses, discussion, and systematic approaches to develop clinical prehabilitation standards
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