680 research outputs found

    Fermi systems with long scattering lengths

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    Ground state energies and superfluid gaps are calculated for degenerate Fermi systems interacting via long attractive scattering lengths such as cold atomic gases, neutron and nuclear matter. In the intermediate region of densities, where the interparticle spacing (1/kF)(\sim 1/k_F) is longer than the range of the interaction but shorter than the scattering length, the superfluid gaps and the energy per particle are found to be proportional to the Fermi energy and thus differs from the dilute and high density limits. The attractive potential increase linearly with the spin-isospin or hyperspin statistical factor such that, e.g., symmetric nuclear matter undergoes spinodal decomposition and collapses whereas neutron matter and Fermionic atomic gases with two hyperspin states are mechanically stable in the intermediate density region. The regions of spinodal instabilities in the resulting phase diagram are reduced and do not prevent a superfluid transition.Comment: extended and revised version, 7 pages including new phase diagra

    Early start and stop of biologics: has the time come?

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    Despite considerable advances in the management of rheumatoid arthritis, results are still not satisfactory for all patients. The treatment goal in rheumatoid arthritis is remission, and there currently are numerous conventional and biological medications available to reach this aim. There are also different treatment strategies but with only limited comparative evidence about their efficacies. More patients now achieve remission while on treatment, but it remains elusive in the majority of patients. Treatment-free remission, the ultimate goal of therapy, is only achieved in very few patients; even when this happens, it is most likely due to the natural course of the disease rather than to any specific therapies. Modern treatment is based on the initiation of aggressive therapy as soon as the diagnosis is established, and on modifying or intensifying therapy guided by frequent assessment of disease activity. In this commentary we will discuss the current treatment paradigm as well as the possibility of an induction-maintenance regimen with biological disease-modifying antirheumatic drugs in early rheumatoid arthriti

    Inducing Ni Sensitivity in the Ni Hyperaccumulator Plant Alyssum inflatum Nyárády (Brassicaceae) by Transforming with CAX1, a Vacuolar Membrane Calcium Transporter

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    The importance of calcium in nickel tolerance was studied in the nickel hyperaccumulator plant Alyssum inflatum by gene transformation of CAX1, a vacuolar membrane transporter that reduces cytosolic calcium. CAX1 from Arabidopsis thaliana with a CaMV35S promoter accompanying a kanamycin resistance gene was transferred into A. inflatum using Agrobacterium tumefaciens. Transformed calli were subcultured three times on kanamycin-rich media and transformation was confirmed by PCR using a specific primer for CAX1. At least 10 callus lines were used as a pool of transformed material. Both transformed and untransformed calli were treated with varying concentrations of either calcium (1–15 mM) or nickel (0– 500 lM) to compare their responses to those ions. Increased external calcium generally led to increased callus biomass, however, the increase was greater for untransformed callus. Further, increased external calcium led to increased callus calcium concentrations. Transformed callus was less nickel tolerant than untransformed callus: under increasing nickel concentrations callus relative growth rate was significantly less for transformed callus. Transformed callus also contained significantly less nickel than untransformed callus when exposed to the highest external nickel concentration (200 lM). We suggest that transformation with CAX1 decreased cytosolic calcium and resulted in decreased nickel tolerance. This in turn suggests that, at low cytosolic calcium concentrations, other nickel tolerance mechanisms (e.g., complexation and vacuolar sequestration) are insufficient for nickel tolerance. We propose that high cytosolic calcium is an important mechanism that results in nickel tolerance by nickel hyperaccumulator plants

    Management of rheumatoid arthritis: consensus recommendations from the Hong Kong Society of Rheumatology

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    Given the recent availability of novel biologic agents for the treatment of rheumatoid arthritis (RA), the Hong Kong Society of Rheumatology has developed consensus recommendations on the management of RA, which aim at providing guidance to local physicians on appropriate, literature-based management of this condition, specifically on the indications and monitoring of the biologic disease-modifying anti-rheumatic drugs (DMARDs). The recommendations were developed using the European League Against Rheumatism (EULAR) recommendations for the management of early arthritis as a guide, along with local expert opinion. As significant joint damage occurs early in the course of RA, initiating therapy early is key to minimizing further damage and disability. Patients with serious disease or poor prognosis should receive early, aggressive therapy. Because of its good efficacy and safety profile, methotrexate is considered the standard first-line DMARD for most treatment-naïve RA patients. Patients with a suboptimal response to methotrexate monotherapy should receive step-up (combination) therapy with either the synthetic or biologic DMARDs. In recent years, combinations of methotrexate with tocilizumab, abatacept, or rituximab have emerged as effective therapies in patients who are unresponsive to traditional DMARDs or the anti-tumor necrosis factor (TNF)-α agents. As biologic agents can increase the risk of infections such as tuberculosis and reactivation of viral hepatitis, screening for the presence of latent tuberculosis and chronic viral hepatitis carrier state is recommended before initiating therapy

    Complexity Theory for a New Managerial Paradigm: A Research Framework

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    In this work, we supply a theoretical framework of how organizations can embed complexity management and sustainable development into their policies and actions. The proposed framework may lead to a new management paradigm, attempting to link the main concepts of complexity theory, change management, knowledge management, sustainable development, and cybernetics. We highlight how the processes of organizational change have occurred as a result of the move to adapt to the changes in the various global and international business environments and how this transformation has led to the shift toward the present innovation economy. We also point how organizational change needs to deal with sustainability, so that the change may be consistent with present needs, without compromising the future

    Untangling knowledge creation and knowledge integration in enterprise wikis

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    A central challenge organizations face is how to build, store, and maintain knowledge over time. Enterprise wikis are community-based knowledge systems situated in an organizational context. These systems have the potential to play an important role in managing knowledge within organizations, but the motivating factors that drive individuals to contribute their knowledge to these systems is not very well understood. We theorize that enterprise wiki initiatives require two separate and distinct types of knowledge-sharing behaviors to succeed: knowledge creation (KC) and knowledge integration (KI). We examine a Wiki initiative at a major German bank to untangle the motivating factors behind KC and KI. Our results suggest KC and KI are indeed two distinct behaviors, reconcile inconsistent findings from past studies on the role of motivational factors for knowledge sharing to establish shared electronic knowledge resources in organizations, and identify factors that can be leveraged to tilt behaviors in favor of KC or KI
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