4,029 research outputs found

    Monetary cost for time spent in everyday physical activities.

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    publisher: Elsevier articletitle: Monetary cost for time spent in everyday physical activities journaltitle: Social Science & Medicine articlelink: http://dx.doi.org/10.1016/j.socscimed.2014.02.043 content_type: article copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.publisher: Elsevier articletitle: Monetary cost for time spent in everyday physical activities journaltitle: Social Science & Medicine articlelink: http://dx.doi.org/10.1016/j.socscimed.2014.02.043 content_type: article copyright: Copyright © 2014 Elsevier Ltd. All rights reserved.We measured utility curves for the hypothetical monetary costs as a function of time engaged in three everyday physical activities: walking, standing, and sitting. We found that activities requiring more physical exertion resulted in steeper discount curves, i.e., perceived cost as a function of time. We also examined the effects of gain vs. loss framing (whether the activity brought additional rewards or prevented losses) as well as the effects of the individual factors of gender, income, and BMI. Steeper discount curves were associated with higher income (annual household ≥ median of $45,000) and gain framing (which indicates loss aversion). There were interactions between gender and frame, and also income and frame: Females and higher income participants showed loss aversion whereas males and lower income participants were not affected by framing. Males showed less discounting in gain frames relative to females, whereas females showed less discounting in loss frames relative to males. In gain frames, higher income participants discounted more but in loss frames there was no effect of income. We also found individual tendencies for discounting across activities: if an individual exhibited steeper discounting for one activity, they were also more likely to exhibit steeper discounting for the other activities. These results have implications for designers of interventions to encourage non-exercise physical activities, suggesting that loss-framed incentives are more effective for women and those with middle class (or greater) incomes. Furthermore loss framed incentives have more uniform impact across income brackets because people discount loss frames similarly regardless of income whereas those with middle-class incomes are not as motivated by gain frames. Our results also demonstrate a general method for examining the costs of effort associated with everyday activities

    Determinants of the creatinine clearance to glomerular filtration rate ratio in patients with chronic kidney disease: a cross-sectional study

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    BACKGROUND: Creatinine secretion, as quantified by the ratio of creatinine clearance (CrCl) to glomerular filtration rate (GFR), may introduce another source of error when using serum creatinine concentration to estimate GFR. Few studies have examined determinants of the CrCl/GFR ratio. We sought to study whether higher levels of albuminuria would be associated with higher, and being non-Hispanic black with lower, CrCl/GFR ratio. METHODS: We did a cross-sectional analysis of 1342 patients with chronic kidney disease from the Chronic Renal Insufficiency Cohort (CRIC) who had baseline measure of iothalamate GFR (iGFR) and 24-hour urine collections. Our predictors included urine albumin as determined from 24-hour urine collections (categorized as: <30, 30-299, 300-2999 and ≥3000 mg), and race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic). Our outcome was CrCl/iGFR ratio, a measure of creatinine secretion. RESULTS: Mean iGFR was 48.0 ± 19.9 mL/min/1.73 m(2), median albuminuria was 84 mg per day, and 36.8% of the study participants were non-Hispanic black. Mean CrCl/iGFR ratio was 1.19 ± 0.48. There was no association between the CrCl/iGFR ratio and urine albumin (coefficient 0.11 [95% CI−0.01-0.22] for higest verus lowest levels of albuminuria, p = 0.07). Also, there was no association between race/ethnicity and CrCl/iGFR ratio (coefficient for non-Hispanic blacks was−0.03 [95% CI−0.09-0.03] compared with whites, p = 0.38). CONCLUSIONS: Contrary to what had been suggested by prior smaller studies, CrCl/GFR ratio does not vary with degree of proteinuria or race/ethnicity. The ratio is also closer to 1.0 than reported by several frequently cited reports in the literature

    Is it better to treat chronic hepatitis B as early as possible?—Con

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    Ideally, treatment of chronic hepatitis B in its early stage prior to irreversible liver damage should be most effective in preventing adverse clinical outcome. However, currently available treatments have low efficacy in achieving sustained response among patients in the early phase of chronic hepatitis B infection when the immune response to hepatitis B virus is weak. This review will provide evidence why a ‘wait and monitor’ approach is appropriate for chronic hepatitis B patients who are in the immune tolerant phase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73513/1/j.1440-1746.2004.03660.x.pd

    Finite-size effects on multibody neutrino exchange

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    The effect of multibody massless neutrino exchanges between neutrons inside a finite-size neutron star is studied. We use an effective Lagrangian, which incorporates the effect of the neutrons on the neutrinos. Following Schwinger, it is shown that the total interaction energy density is computed by comparing the zero point energy of the neutrino sea with and without the star. It has already been shown that in an infinite-size star the total energy due to neutrino exchange vanishes exactly. The opposite claim that massless neutrino exchange would produce a huge energy is due to an improper summation of an infrared-divergent quantity. The same vanishing of the total energy has been proved exactly in the case of a finite star in a one-dimensional toy model. Here we study the three-dimensional case. We first consider the effect of a sharp star border, assumed to be a plane. We find that there is a non- vanishing of the zero point energy density difference between the inside and the outside due to the refraction index at the border and the consequent non-penetrating waves. An analytical and numerical calculation for the case of a spherical star with a sharp border confirms that the preceding border effect is the dominant one. The total result is shown to be infrared-safe, thus confirming that there is no need to assume a neutrino mass. The ultraviolet cut-offs, which correspond in some sense to the matching of the effective theory with the exact one, are discussed. Finally the energy due to long distance neutrino exchange is of the order of 1081013GeVperneutron10^{-8} -- 10^{-13} GeV per neutron, i.e. negligible with respect to the neutron mass density.Comment: Latex file (Revtex), 34 pages, 8 postscripted figure

    End-stage renal disease preceded by rapid declines in kidney function: a case series

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    <p>Abstract</p> <p>Background</p> <p>Few studies have defined alternate pathways by which chronic kidney disease (CKD) patients transition into end-stage renal disease (ESRD).</p> <p>Methods</p> <p>We studied all consecutive patients initiated on maintenance hemodialysis or peritoneal dialysis over several years at two dialysis units in Northern California. Rapid decline in kidney function was considered to have occurred if a patient was documented to have estimated GFR > 30 ml/min/1.73 m<sup>2 </sup>within three months prior to the initiation of chronic dialysis.</p> <p>Results</p> <p>We found that 8 out of 105 incident chronic dialysis patients one dialysis unit (7.6%; 95% confidence interval 3.4-14.5%) and 9 out of 71 incident patients at another (12.7%, 95% CI 6.0%-22.7%) suffered rapid decline in kidney function that was the immediate precipitant for the need for permanent renal replacement therapy. All these patients started hemodialysis and all relied on catheters for vascular access. Documentation submitted to United States Renal Data System did not fully reflect the health status of these patients during their "pre-ESRD" period.</p> <p>Conclusions</p> <p>A sizeable minority of ESRD cases are preceded by rapid declines in kidney function. The importance of these periods of rapid decline may have been under-appreciated in prior studies of the natural history of CKD and ESRD.</p

    Flood impact assessment under climate change scenarios in central Taipei area, Taiwan

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    Providing effective information regarding flood control for responding climate change is essential to future flood risk management for cities. This study simulated and assessed the impacts of flooding for future climate change scenarios in Taipei city, Taiwan. We modelled rainfall events, generated by general circulation models, with different return periods. The flood extents and damage in the Central Taipei Area for the A1B climate change scenarios were compared to the ones, caused by the rainfall events with same return periods, without climate change (baseline scenario). The proposed approach provides potential flooding maps and flood damage assessment for climate change scenarios as useful information for flood risk management in urban areas.The work is supported by the National Science Council, Taiwan (NSC 99-2915-I-002-120) and the CORFU project, funded by the European Commission through Framework Programme 7, Grant Number 244047

    Vortex Core Structure and Dynamics in Layered Superconductors

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    We investigate the equilibrium and nonequilibrium properties of the core region of vortices in layered superconductors. We discuss the electronic structure of singly and doubly quantized vortices for both s-wave and d-wave pairing symmetry. We consider the intermediate clean regime, where the vortex-core bound states are broadened into resonances with a width comparable to or larger than the quantized energy level spacing, and calculate the response of a vortex core to an {\em a.c.} electromagnetic field for vortices that are pinned to a metallic defect. We concentrate on the case where the vortex motion is nonstationary and can be treated by linear response theory. The response of the order parameter, impurity self energy, induced fields and currents are obtained by a self-consistent calculation of the distribution functions and the excitation spectrum. We then obtain the dynamical conductivity, spatially resolved in the region of the core, for external frequencies in the range, 0.1\Delta < \hbar\omega \lsim 3\Delta. We also calculate the dynamically induced charge distribution in the vicinity of the core. This charge density is related to the nonequilibrium response of the bound states and collective mode, and dominates the electromagnetic response of the vortex core.Comment: Presented at the 2000 Workshop on ``Microscopic Structure and Dynamics of Vortices in Unconventional Superconductors and Superfluids'', held at the Max Planck Institute for the Physics of Complex Systems in Dresden, Germany (28 pages with 15 figures). Alternate version with higher resolution figures: http://snowmass.phys.nwu.edu/~sauls/Eprints/Dresden2000.htm

    Potential role of differential medication use in explaining excess risk of cardiovascular events and death associated with chronic kidney disease: A cohort study

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    <p>Abstract</p> <p>Background</p> <p>Patients with chronic kidney disease (CKD) are less likely to receive cardiovascular medications. It is unclear whether differential cardiovascular drug use explains, in part, the excess risk of cardiovascular events and death in patients with CKD and coronary heart disease (CHD).</p> <p>Methods</p> <p>The ADVANCE Study enrolled patients with new onset CHD (2001-2003) who did (N = 159) or did not have (N = 1088) CKD at entry. The MDRD equation was used to estimate glomerular filtration rate (eGFR) using calibrated serum creatinine measurements. Patient characteristics, medication use, cardiovascular events and death were ascertained from self-report and health plan electronic databases through December 2008.</p> <p>Results</p> <p>Post-CHD event ACE inhibitor use was lower (medication possession ratio 0.50 vs. 0.58, P = 0.03) and calcium channel blocker use higher (0.47 vs. 0.38, P = 0.06) in CKD vs. non-CKD patients, respectively. Incidence of cardiovascular events and death was higher in CKD vs. non-CKD patients (13.9 vs. 11.5 per 100 person-years, P < 0.001, respectively). After adjustment for patient characteristics, the rate of cardiovascular events and death was increased for eGFR 45-59 ml/min/1.73 m<sup>2 </sup>(hazard ratio [HR] 1.47, 95% CI: 1.10 to 2.02) and eGFR < 45 ml/min/1.73 m<sup>2 </sup>(HR 1.58, 95% CI: 1.00 to 2.50). After further adjustment for statins, β-blocker, calcium channel blocker, ACE inhibitor/ARB use, the association was no longer significant for eGFR 45-59 ml/min/1.73 m<sup>2 </sup>(HR 0.82, 95% CI: 0.25 to 2.66) or for eGFR < 45 ml/min/1.73 m<sup>2 </sup>(HR 1.19, 95% CI: 0.25 to 5.58).</p> <p>Conclusions</p> <p>In adults with CHD, differential use of cardiovascular medications may contribute to the higher risk of cardiovascular events and death in patients with CKD.</p

    Brain changes associated with cognitive and emotional factors in chronic pain : a systematic review

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    An emerging technique in chronic pain research is MRI, which has led to the understanding that chronic pain patients display brain structure and function alterations. Many of these altered brain regions and networks are not just involved in pain processing, but also in other sensory and particularly cognitive tasks. Therefore, the next step is to investigate the relation between brain alterations and pain related cognitive and emotional factors. This review aims at providing an overview of the existing literature on this subject. Pubmed, Web of Science and Embase were searched for original research reports. Twenty eight eligible papers were included, with information on the association of brain alterations with pain catastrophizing, fear-avoidance, anxiety and depressive symptoms. Methodological quality of eligible papers was checked by two independent researchers. Evidence on the direction of these associations is inconclusive. Pain catastrophizing is related to brain areas involved in pain processing, attention to pain, emotion and motor activity, and to reduced top-down pain inhibition. In contrast to pain catastrophizing, evidence on anxiety and depressive symptoms shows no clear association with brain characteristics. However, all included cognitive or emotional factors showed significant associations with resting state fMRI data, providing that even at rest the brain reserves a certain activity for these pain-related factors. Brain changes associated with illness perceptions, pain attention, attitudes and beliefs seem to receive less attention in literature. Significance: This review shows that maladaptive cognitive and emotional factors are associated with several brain regions involved in chronic pain. Targeting these factors in these patients might normalize specific brain alterations
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