464 research outputs found

    Analisa Persepsi Atas Five Aspect Meal Model Dan Pengaruhnya Terhadap Minat Beli Ulang Konsumen Folks Coffee and Tea

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    Dewasa ini, orang-orang memperhatikan hal-hal lain di luar produk dan jasa yang ditawarkan. Perhatian tersebut lebih besar lagi diberikan pada hospitality industry. Kepuasan secara keseluruhan yang dirasakan oleh konsumen di dalam restoran disebut dining experience. Untuk menciptakan suatu pengalaman berkesan (dining experience) ada 5 aspek penting yang harus diperhatikan, yaitu room, meeting, product, management control system, dan atmosphere. Teknik analisa yang digunakan adalah deskriptif dan kausal dengan pendekatan kuantitatif. Hasil penelitian menunjukkan bahwa variable room, product, dan atmosphere merupakan variabel-variabel yang mempengaruhi minat beli ulang konsumen di Folks Coffee and Tea

    Sixth-Order Vacuum-Polarization Contribution to the Lamb Shift of the Muonic Hydrogen

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    The sixth-order electron-loop vacuum-polarization contribution to the 2P1/22S1/22P_{1/2} - 2S_{1/2} Lamb shift of the muonic hydrogen (μp+\mu^{-} p^+ bound state) has been evaluated numerically. Our result is 0.007608(1) meV. This eliminates the largest uncertainty in the theoretical calculation. Combined with the proposed precision measurement of the Lamb shift it will lead to a very precise determination of the proton charge radius.Comment: 4 pages, 5 figures the totoal LS number is change

    Ventricular structure, function, and mechanics at high altitude: chronic remodeling in Sherpa vs. short-term lowlander adaptation

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    Short-term, high-altitude (HA) exposure raises pulmonary artery systolic pressure (PASP) and decreases left-ventricular (LV) volumes. However, relatively little is known of the long-term cardiac consequences of prolonged exposure in Sherpa, a highly adapted HA population. To investigate short-term adaptation and potential long-term cardiac remodeling, we studied ventricular structure and function in Sherpa at 5,050 m (n = 11; 31 ± 13 yr; mass 68 ± 10 kg; height 169 ± 6 cm) and lowlanders at sea level (SL) and following 10 ± 3 days at 5,050 m (n = 9; 34 ± 7 yr; mass 82 ± 10 kg; height 177 ± 6 cm) using conventional and speckle-tracking echocardiography. At HA, PASP was higher in Sherpa and lowlanders compared with lowlanders at SL (both P < 0.05). Sherpa had smaller right-ventricular (RV) and LV stroke volumes than lowlanders at SL with lower RV systolic strain (P < 0.05) but similar LV systolic mechanics. In contrast to LV systolic mechanics, LV diastolic, untwisting velocity was significantly lower in Sherpa compared with lowlanders at both SL and HA. After partial acclimatization, lowlanders demonstrated no change in the RV end-diastolic area; however, both RV strain and LV end-diastolic volume were reduced. In conclusion, short-term hypoxia induced a reduction in RV systolic function that was also evident in Sherpa following chronic exposure. We propose that this was consequent to a persistently higher PASP. In contrast to the RV, remodeling of LV volumes and normalization of systolic mechanics indicate structural and functional adaptation to HA. However, altered LV diastolic relaxation after chronic hypoxic exposure may reflect differential remodeling of systolic and diastolic LV function. exposure to high altitude (HA) challenges the cardiovascular system to meet the metabolic demand for oxygen (O2) in an environment where arterial O2 content is markedly reduced. The drop in arterial O2 has both direct and indirect consequences for the heart, including depressed inotropy of cardiac muscle (40, 44), changes in blood volume and viscosity, and vasoconstriction of the pulmonary arteries (33). Despite these broad physiological changes, which have been reviewed previously (28, 49), there is evidence that the heart copes relatively well at HA (29, 34). Short-term HA exposure in lowland natives is characterized by a decreased plasma volume (PV), an increased sympathetic nerve activity, and pulmonary vasoconstriction (17, 30, 37), all of which have considerable impact on cardiac function and in time, could stimulate cardiac remodeling. Himalayan native Sherpa, who are of Tibetan lineage and have resided at HA for ∼25,000 yr (2), are well adapted to life at HA, demonstrating greater lung-diffusing capacity (11) and an absence of polycythemia compared with acclimatized lowlanders (4). Previous studies have also reported Sherpa to have higher maximal heart rates (HRs) and only moderate pulmonary hypertension compared with lowlanders at HA (11, 25). Due to their longevity at HA, Sherpa provide an excellent model to investigate the effects of chronic hypoxic exposure. Despite this, neither the acute nor lifelong effects of HA on right- and left-ventricular (RV and LV, respectively) structure and function have been fully assessed in lowlanders or the unique Sherpa population. Due to the unique arrangement of myofibers, cardiac form and function are intrinsically linked, as reflected in the cardiac mechanics (LV twist and rotation and ventricular strain) that underpin ventricular function. In response to altered physiological demand, ventricular mechanics acutely change (16, 41) and chronically remodel (31, 42) to reduce myofiber stress and achieve efficient ejection (5, 47). Therefore, concomitant examination of myocardial mechanics and ventricular structure in both the acute and chronic HA setting will provide novel insight into human adaptation to hypoxia. To investigate the effects of chronic hypoxic exposure, we compared ventricular volumes and mechanics in Sherpa at 5,050 m with lowlanders at sea level (SL). In addition, to reveal potential stimuli for remodeling and to examine the time course of adaptation, we compared Sherpa with lowlanders after short-term HA exposure. We hypothesized that: 1) Sherpa would exhibit smaller LV volumes and a higher RV/LV ratio than lowlanders at SL, 2) LV mechanics in Sherpa will closely resemble those of lowlanders at SL, and 3) following partial acclimatization to HA, LV volumes would be reduced in lowlanders and LV mechanics acutely increased

    Improved α4\alpha^4 Term of the Muon Anomalous Magnetic Moment

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    We have completed the evaluation of all mass-dependent α4\alpha^4 QED contributions to the muon g2g-2, or aμa_\mu, in two or more different formulations. Their numerical values have been greatly improved by an extensive computer calculation. The new value of the dominant α4\alpha^4 term A2(8)(mμ/me)A_2^{(8)} (m_\mu / m_e) is 132.6823 (72), which supersedes the old value 127.50 (41). The new value of the three-mass term A3(8)(mμ/me,mμ/mτ)A_3^{(8)} (m_\mu / m_e, m_\mu / m_\tau) is 0.0376 (1). The term A2(8)(mμ/mτ)A_2^{(8)} (m_\mu / m_\tau) is crudely estimated to be about 0.005 and may be ignored for now. The total QED contribution to aμa_\mu is 116584719.58(0.02)(1.15)(0.85)×1011116 584 719.58 (0.02)(1.15)(0.85) \times 10^{-11}, where 0.02 and 1.15 are uncertainties in the α4\alpha^4 and α5\alpha^5 terms and 0.85 is from the uncertainty in α\alpha measured by atom interferometry. This raises the Standard Model prediction by 13.9×101113.9 \times 10^{-11}, or about 1/5 of the measurement uncertainty of aμa_\mu. It is within the noise of current uncertainty (100×1011\sim 100 \times 10^{-11}) in the estimated hadronic contributions to aμa_\mu.Comment: Appendix A has been rewritten extensively. It includes the 4th-order calculation for illustration. Version accepted by PR

    Techniques in Analytic Lamb Shift Calculations

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    Quantum electrodynamics has been the first theory to emerge from the ideas of regularization and renormalization, and the coupling of the fermions to the virtual excitations of the electromagnetic field. Today, bound-state quantum electrodynamics provides us with accurate theoretical predictions for the transition energies relevant to simple atomic systems, and steady theoretical progress relies on advances in calculational techniques, as well as numerical algorithms. In this brief review, we discuss one particular aspect connected with the recent progress: the evaluation of relativistic corrections to the one-loop bound-state self-energy in a hydrogenlike ion of low nuclear charge number, for excited non-S states, up to the order of alpha (Zalpha)^6 in units of the electron mass. A few details of calculations formerly reported in the literature are discussed, and results for 6F, 7F, 6G and 7G states are given.Comment: 16 pages, LaTe

    One-loop self-energy correction to the 1s and 2s hyperfine splitting in H-like systems

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    The one-loop self-energy correction to the hyperfine splitting of the 1s and 2s levels in H-like low-Z atoms is evaluated to all orders in Z\alpha. The results are compared to perturbative calculations. The residual higher-order contribution is evaluated. Implications to the specific difference of the hyperfine structure intervals 8\Delta \nu_2 - \Delta \nu_1 in He^+ are investigated.Comment: 17 pages, RevTeX, 3 figure

    Thermal Properties of Two-Dimensional Advection Dominated Accretion Flow

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    We study the thermal structure of the widely adopted two-dimensional advection dominated accretion flow (ADAF) of Narayan & Yi (1995a). The critical radius for a given mass accretion rate, outside of which the optically thin hot solutions do not exist in the equatorial plane, agrees with one-dimensional study. However, we find that, even within the critical radius, there always exists a conical region of the flow, around the pole, which cannot maintain the assumed high electron temperature, regardless of the mass accretion rate, in the absence of radiative heating. This could lead to torus-like advection inflow shape since, in general, the ions too will cool down. We also find that Compton preheating is generally important and, if the radiative efficiency, defined as the luminosity output divided by the mass accretion rate times the velocity of light squared, is above sim 4x10^-3, the polar region of the flow is preheated above the virial temperature by Compton heating and it may result in time-dependent behaviour or outflow while accretion continues in the equatorial plane. Thus, under most relevant circumstances, ADAF solutions may be expected to be accompanied by polar outflow winds. While preheating instabilities exist in ADAF, as for spherical flows, the former are to some extent protected by their characteristically higher densities and higher cooling rates, which reduce their susceptibility to Compton driven overheating.Comment: 18 pages including 4 figures. AASTEX. Submitted to Ap

    Living with multimorbidity? The lived experience of multiple chronic conditions in later life

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    Multimorbidity is defined biomedically as the co-existence of two or more long-term conditions in an individual. Globally, the number of people living with multiple conditions is increasing, posing stark challenges both to the clinical management of patients and the organisation of health systems. Qualitative literature has begun to address how concurrency affects the self-management of chronic conditions, and the concept of illness prioritisation predominates. In this article, we adopt a phenomenological lens to show how older people with multiple conditions experience illness. This UK study was qualitative and longitudinal in design. Sampling was purposive and drew upon an existing cohort study. In total, 15 older people living with multiple conditions took part in 27 in-depth interviews. The practical stages of analysis were guided by Constructivist Grounded Theory. We argue that the concept of multimorbidity as biomedically imagined has limited relevance to lived experience, while concurrency may also be erroneous. In response, we outline a lived experience of multiple chronic conditions in later life, which highlights differences between clinical and lay assumptions and makes the latter visible
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