2,356 research outputs found

    Rovibrational Resonance Effects In Collision-Induced Electronic Energy Transfer: I2(E,v=0-2)+CF4

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    Collisions of I-2 in the E(0(g)(+)) electronic state with CF4 molecules induce electronic energy transfer to the nearby D, beta, and D-\u27 ion-pair states. Simulations of dispersed fluorescence spectra reveal collision-induced electronic energy transfer rate constants and final vibrational state distributions within each final electronic state. In comparison with earlier reports on I-2(upsilon(E)=0-2) collisions with He or Ar atoms, we find markedly different dynamics when I-2, excited to the same rovibronic states, collides with CF4. Final vibrational state distributions agree with the associated Franck-Condon factors with the initially prepared state to a greater degree than those found with He or Ar collision partners and suggest that internal degrees of freedom in the CF4 molecule represent a substantial means for accepting the accompanying loss of I-2 vibronic energy. Comparison of the E -\u3e D transfer of I-2 excited to the J=23 and J=55 levels of the upsilon(E)=0 state reveals the onset of specific, nonstatistical dynamics as the available energy is increased above the threshold for excitation of the low frequency nu(2) bending mode of CF4. (c) 2006 American Institute of Physics

    Evaluating the contributions of regional trade agreements to governance of service trade

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    Since the early 1990s, regional trade agreements (RTAs) covering trade in services have proliferated, with 95 RTAs on services notified to the World Trade Organization (WTO) under Article V of the General Agreement on Trade in Services (GATS), as of June 2011. This paper discusses how RTAs support or debilitate the GATS in its governance function as the keeper of rules and liberalization commitments on services trade for WTO members. It addresses this question and its implications for governance by focusing on four different issues: architecture; compliance; ability to promote reforms; and actual impact of RTAs on fostering services trade

    Open Source/Open Course Learning: Lessons for Educators from Free and Open Source Software

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    Free/Open Source Software (FOSS) has transformed the software industry. As noted by other authors in this issue, academic information technology (IT) is already realizing many benefits by adopting open software; such benefits include reduced cost, absence of user restrictions and vendor lock-in, and consistency with traditional academic values of openness and sharing. The greatest benefit of the FOSS movement for educators, however, is not cheaper or better software but the model it provides of a social, cultural, and legal framework capable of harnessing IT to improve learning. At this point, some may object: "Universities have been using IT for a half-century and hardly need a new model. " But formal education has used IT principally to support administration and research and has been slow to adapt it to improve its core business of teaching and learning. Traditional learning is still too passive, too parochial, too hierarchical, and too artificial. By harnessing IT effectively, educators can make instruction more graphic, dynamic, and active than it is now. They can introduce students to real-world experts and real-world problems and create communities of practice that promote learning. Others may object that a huge amount of online content is already available at no charge, so open source learning is old news. But price is the least important issue in open source learning, as a review of the factors critical to the success of FOSS will make clear

    The Spectroscopy And A State Dynamics Of The NeIBr Van Der Waals Complex

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    The A  3Π1←X  1Σ+ laser‐induced fluorescence excitation spectrum of the NeIBr van der Waals complex is reported and analyzed to extract information regarding the structure and vibrational predissociation dynamics of the complex. While no definitive geometric information regarding NeIBr is obtained, our data indicate that a linear geometry is at least plausible. The vibrational predissociation lifetimes are a strong function of A state vibrational level and range from 2.6 to 23 ps. The variation in lifetime with vibrational level is consistent with the results of previous measurements on rare gas–halogen complexes, particularly NeBr2

    Activated lymphocyte recruitment into the tumor microenvironment following preoperative sipuleucel-T for localized prostate cancer.

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    BackgroundSipuleucel-T is a US Food and Drug Administration-approved immunotherapy for asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer (mCRPC). Its mechanism of action is not fully understood. This prospective trial evaluated the direct immune effects of systemically administered sipuleucel-T on prostatic cancer tissue in the preoperative setting.MethodsPatients with untreated localized prostate cancer were treated on an open-label Phase II study of sipuleucel-T prior to planned radical prostatectomy (RP). Immune infiltrates in RP specimens (posttreatment) and in paired pretreatment biopsies were evaluated by immunohistochemistry (IHC). Correlations between circulating immune response and IHC were assessed using Spearman rank order.ResultsOf the 42 enrolled patients, 37 were evaluable. Adverse events were primarily transient, mild-to-moderate and infusion related. Patients developed T cell proliferation and interferon-γ responses detectable in the blood following treatment. Furthermore, a greater-than-three-fold increase in infiltrating CD3(+), CD4(+) FOXP3(-), and CD8(+) T cells was observed in the RP tissues compared with the pretreatment biopsy (binomial proportions: all P < .001). This level of T cell infiltration was observed at the tumor interface, and was not seen in a control group consisting of 12 concurrent patients who did not receive any neoadjuvant treatment prior to RP. The majority of infiltrating T cells were PD-1(+) and Ki-67(+), consistent with activated T cells. Importantly, the magnitude of the circulating immune response did not directly correlate with T cell infiltration within the prostate based upon Spearman's rank order correlation.ConclusionsThis study is the first to demonstrate a local immune effect from the administration of sipuleucel-T. Neoadjuvant sipuleucel-T elicits both a systemic antigen-specific T cell response and the recruitment of activated effector T cells into the prostate tumor microenvironment

    Role of Fiber Orientation in Atrial Arrythmogenesis

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    Electrical wave-front propagation in the atria is determined largely by local fiber orientation. Recent study suggests that atrial fibrillation (AF) progresses with enhanced anisotropy. In this work, a 3D rabbit atrial anatomical model at 20 × 20 × 20 μm3 resolution with realistic fiber orientation was constructed based on the novel contrast-enhanced micro-CT imaging. The Fenton-Karma cellular activation model was adapted to reproduce rabbit atrial action potential period of 80 ms. Diffusivities were estimated for longitudinal and transverse directions of the fiber orientation respectively. Pacing was conducted in the 3D anisotropic atrial model with a reducing S2 interval to facilitate initiation of atrial arrhythmia. Multiple simulations were conducted with varying values of diffusion anisotropy and stimulus locations to evaluate the role of anisotropy in initiating AF. Under physiological anisotropy conditions, a rapid right atrial activation was followed by the left atrial activation. Excitation waves reached the atrio-ventricular border where they terminated. Upon reduction of conduction heterogeneity, re-entry was initiated by the rapid pacing and the activation of both atrial chambers was almost simultaneous. Myofiber orientation is an effective mechanism for regulating atrial activation. Modification of myoarchitecture is proarrhythmic

    Physical and Mechanical Properties of LoVAR: A New Lightweight Particle-Reinforced Fe-36Ni Alloy

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    Fe-36Ni is an alloy of choice for low thermal expansion coefficient (CTE) for optical, instrument and electrical applications in particular where dimensional stability is critical. This paper outlines the development of a particle-reinforced Fe-36Ni alloy that offers reduced density and lower CTE compared to the matrix alloy. A summary of processing capability will be given relating the composition and microstructure to mechanical and physical properties

    Multidimensional apathy in ALS:validation of the Dimensional Apathy Scale

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    AIM: Apathy is a prominent symptom of amyotrophic lateral sclerosis (ALS), but measurement is confounded by physical disability. Furthermore, it has been traditionally measured as a unidimensional symptom despite research demonstrating a multifaceted construct. The new Dimensional Apathy Scale (DAS) has been specifically designed for patients with motor disability to measure 3 neurologically based subtypes of apathy: Executive, Emotional and Initiation. We aimed to explore this behavioural symptom by examining the substructure of apathy in ALS and to determine the reliability and validity of the DAS in patients and their carers.  METHOD: Patients and carers were recruited through the national Scottish Motor Neurone Disease Register and were asked to complete the DAS, the standardised Apathy Evaluation Scale, and the Geriatric Depression Scale-Short Form. 83 patients with ALS, 75 carers and 83 sex-matched, age-matched and education-matched controls participated.  RESULTS: When compared with healthy controls, patients showed a significant increase in apathy on the Initiation subscale, and were significantly less apathetic on the Emotional subscale. Scores on the DAS patient and carer versions did not significantly differ. Internal consistency reliability, convergent and discriminant validity were found to be good for the DAS subscales. There was no association between the DAS and functional disability using the ALS Functional Rating Scale.  CONCLUSIONS: Apathy in ALS is characterised by a specific profile of increased initiation apathy and reduced emotional apathy. The DAS is a reliable and valid measure for the assessment of multidimensional apathy in ALS

    Evaluation Framework for Water Quality Trading Programs in the Chesapeake Bay Watershed

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    Water quality trading programs are being proposed and implemented across the US in a variety of forms and with differing objectives. The programs being proposed and implemented in the Chesapeake Bay region are no exception. Against this background the Chesapeake Bay Program's Scientific and Technical Advisory Committee and the Mid-Atlantic Water Program requested a general framework to inform and guide the evaluation of the performance trading programs. This resulting report was developed by a workgroup comprised of ten individuals with extensive experience in the study, design, and evaluation of trading programs. While the impetus for this report was to improve evaluation of trading programs in the Chesapeake Bay region, the evaluation framework is broad enough to apply to trading programs in general

    Effects of Cardiac Structural Remodelling During Heart Failure on Cardiac Excitation – Insights from a Heterogeneous 3D Model of the Rabbit Atria

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    Heart failure is a leading cause of morbidity and mortality in the western world. One of the effects of heart failure is the structural remodelling of cardiac tissue, including tissue dilation and development of fibrosis. It is therefore important to study these changes and their effect on cardiac activity, in order to gain a better understanding of the underlying mechanisms in arrhythmogenesis, which will hopefully enable us to develop better treatments for heart failure. In this study we developed biophysically detailed models of the rabbit atria for normal and heart failure conditions. These models were used to study the effects of structural remodelling of heart failure on cardiac excitation wave conduction. Anatomical reconstructions of the control and heart failure hearts were based on contrast enhanced micro-CT imaging. Fibre orientation was extracted from the control and heart failure datasets. Effects of heart failure geometry on the activation pattern of atrial excitation waves were analyzed. It was found that atrial activation time increased from the control to the heart failure case in both isotropic and anisotropic conditions, which is attributed primarily to the dilation of tissue caused by heart failure
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