1,888 research outputs found

    Knight Shift and Nuclear Spin Relaxation Rate in a Charge-Ordered State of the One-Dimensional Extended Hubbard Model at Quarter Filling

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    We investigate Knight shift and nuclear spin relaxation rate in a charge ordered state of the one-dimensional extended Hubbard model with a quarter filled band by using RPA around the mean-field solution. It is shown that both quantities show splitting below the critical temperature of the charge order, as is experimentally observed. The relationship between the mount of the splitting in the both quantities and the charge disproportionation rate is discussed.Comment: 7 pages, 6 figures, submitted to J. Phys. Soc. Jp

    A role for TASK-1 (KCNK3) channels in the chemosensory control of breathing

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    Acid-sensitive K+ channels of the tandem P-domain K+-channel family (TASK-1 and TASK-3) have been implicated in peripheral and central respiratory chemosensitivity; however, because of the lack of decisive pharmacological agents, the final proof of the role of the TASK channel in the chemosensory control of breathing has been missing. In the mouse, TASK-1 and TASK-3 channels are dispensable for central respiratory chemosensitivity (Mulkey et al., 2007Go). Here, we have used knock-out animals to determine whether TASK-1 and TASK-3 channels play a role in the carotid body function and chemosensory control of breathing exerted by the carotid body chemoreceptors. Ventilatory responses to hypoxia (10% O2 in inspired air) and moderate normoxic hypercapnia (3–6% CO2 in inspired air) were significantly reduced in TASK-1 knock-out mice. In contrast, TASK-3-deficient mice showed responses to both stimuli that were similar to those developed by their wild-type counterparts. TASK-1 channel deficiency resulted in a marked reduction of the hypoxia (by 49%)- and CO2 (by 68%)-evoked increases in the carotid sinus nerve chemoafferent discharge recorded in the in vitro superfused carotid body/carotid sinus nerve preparations. Deficiency in both TASK-1 and TASK-3 channels increased baseline chemoafferent activity but did not cause a further reduction of the carotid body chemosensory responses. These observations provide direct evidence that TASK-1 channels contribute significantly to the increases in the carotid body chemoafferent discharge in response to a decrease in arterial PO2 or an increase in PCO2/[H+]. TASK-1 channels therefore play a key role in the control of ventilation by peripheral chemoreceptors

    EXAMINING THE MANAGERIAL SKILLS/COMPETENCIES NEEDED TO TRANSITION FROM A TRADITIONAL PERFORMANCE APPRAISAL TO A DEVELOPMENTAL PERFORMANCE APPRAISAL

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    The purpose of this qualitative methods case study was to examine the differences and difficulties of delivering a performance appraisal that was developmental in nature from that of a traditional appraisal, as well as to identify the skills/competencies required of store managers and developmental activities needed to make a transition from a traditional performance appraisal to a performance appraisal system that was developmental in nature. Such a change should not be taken lightly by organizations, given that the task of delivering an evaluation varies. Four research questions guided the study. First, what are the differences between a performance appraisal that is developmental in nature and a traditional one? Second, what are the difficulties in utilizing a performance appraisal as a means to developing talent? Third, what competencies/skills are needed by managers to develop successfully a developmental performance appraisal? Fourth, how can the organization for which you work, prepare a manager to deliver a meaningful evaluation that is part of a developmental program? Qualitative data included subject matter expert interviews to collect their perceptions of the performance evaluation process. Face-to-face interviews were conducted with the store managers to determine their perceptions about ways in which performance evaluation should be carried out to ensure proper feedback and continuous improvement. Statistical and content analysis were conducted on the collection information to answer the study\u27s research questions. The findings of this study did contribute to the literature by pointing to the specific skills that managers need when dealing with developmental appraisal. Furthermore, the time and resource implications to the organization were highlighted, which called for in-depth research on ways in which to either automate or streamline the process, as it could erode organizations’ bottom line. Pertaining to the appraisal tool itself, this study contributed to identifying the need for specific questions and going full circle with timely follow-up discussions with employees in determining the progress made by ensuring their personal and organizational success. This research aided companies in aligning the talent management process with policies and practices. By investing in a performance appraisal process that was developmental and empowering management to conduct appraisals, feedback, and development of employees, retail companies could achieve even more success as an organization can only be as successful as its employees and managers

    Dual-Frequency VSOP Observations of AO 0235+164

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    AO 0235+164 is a very compact, flat spectrum radio source identified as a BL Lac object at a redshift of z=0.94. It is one of the most violently variable extragalactic objects at both optical and radio wavelengths. The radio structure of the source revealed by various ground-based VLBI observations is dominated by a nearly unresolved compact component at almost all available frequencies. Dual-frequency space VLBI observations of AO 0235+164 were made with the VSOP mission in January-February 1999. The array of the Japanese HALCA satellite and co-observing ground radio telescopes in Australia, Japan, China and South Africa allowed us to study AO 0235+164 with an unprecedented angular resolution at frequencies of 1.6 and 5 GHz. We report on the sub-milliarcsecond structural properties of the source. The 5-GHz observations led to an estimate of T_B > 5.8 x 10^{13} K for the rest-frame brightness temperature of the core, which is the highest value measured with VSOP to date.Comment: 8 pages, 8 figures, to appear in Publ. Astron. Soc. Japa
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