31 research outputs found
Remarks on Renormalization of Black Hole Entropy
We elaborate the renormalization process of entropy of a nonextremal and an
extremal Reissner-Nordstr\"{o}m black hole by using the Pauli-Villars
regularization method, in which the regulator fields obey either the
Bose-Einstein or Fermi-Dirac distribution depending on their spin-statistics.
The black hole entropy involves only two renormalization constants. We also
discuss the entropy and temperature of the extremal black hole.Comment: 14 pages, revtex, no figure
Renormalized Thermodynamic Entropy of Black Holes in Higher Dimensions
We study the ultraviolet divergent structures of the matter (scalar) field in
a higher D-dimensional Reissner-Nordstr\"{o}m black hole and compute the matter
field contribution to the Bekenstein-Hawking entropy by using the Pauli-Villars
regularization method. We find that the matter field contribution to the black
hole entropy does not, in general, yield the correct renormalization of the
gravitational coupling constants. In particular we show that the matter field
contribution in odd dimensions does not give the term proportional to the area
of the black hole event horizon.Comment: Final Revision Form as to be published in Physical Review D, ReVTeX,
No Figure
Quantum Creation of Black Hole by Tunneling in Scalar Field Collapse
Continuously self-similar solution of spherically symmetric gravitational
collapse of a scalar field is studied to investigate quantum mechanical black
hole formation by tunneling in the subcritical case where, classically, the
collapse does not produce a black hole.Comment: t clarification of the quantization method in Sec. IV, version to
appear in PR
Exisulind and CP248 induce growth inhibition and apoptosis in human esophageal adenocarcinoma and squamous carcinoma cells
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75468/1/j.1359-4117.2003.01076.x.pd
Black Hole Decay and Quantum Instantons
We study the analytic structure of the S-matrix which is obtained from the
reduced Wheeler-DeWitt wave function describing spherically symmetric
gravitational collapse of massless scalar fields. The complex simple poles in
the S-matrix lead to the wave functions that satisfy the same boundary
condition as quasi-normal modes of a black hole, and correspond to the bounded
states of the Euclidean Wheeler-DeWitt equation. These wave function are
interpreted as quantum instantons.Comment: RevTex, 7 pages, no figure; The wave functions of gr-qc/9912115 are
newly interpreted as quantum instantons describing a black hole decay.
Replaced by the version to be published in Phys. Rev. D, in which the
boundary condition on the apparent horizon is clarifie
Boundary degrees of freedom in fractional quantum Hall effect: Excitations on common boundary of two samples
Using the Carlip's method we have derived the boundary action for the fermion
Chern-Simons theory of quantum Hall effects on a planar region with a boundary.
We have computed both the bulk and edge responses of currents to the external
electric field. From this we obtain the well-known anomaly relation and the
boundary Hall current without introducing any ad hoc assumptions such as the
chirality condition. In addition, the edge current on the common boundary of
two samples is found to be proportional to the difference between Chern-Simons
coupling strengths.Comment: 20 pages, uses revte
25th annual computational neuroscience meeting: CNS-2016
The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong
Hepatitis C testing trends among large commercially insured populations, 2011â2017
ObjectiveWe estimated the rate of hepatitis C testing between 2011 and 2017 among persons with commercial health insurance coverage and compared rates by birth cohort.IntroductionHepatitis C virus (HCV) infection is the most common blood-borne infection in the US, and a leading cause of liver-related morbidity and mortality. Approximately 3.5 million individuals in the US were estimated to have been living with hepatitis C in 2010, and approximately half of them were unaware that they were infected. Among HCV infected individuals, those born between 1945 and 1965 (usually referred to as the baby boomer cohort) represent approximately 75% of current cases. Because of the substantial burden of disease among this age group, CDC expanded its existing hepatitis C risk-based testing recommendations to include a one-time HCV antibody test for all persons born between 1945 and 1965. The United States Preventive Services Task Force (USPSTF) subsequently made the same recommendation in June 2013.DescriptionWe obtained data from the 2011â2017 IBM MarketScanÂź Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases. These data consist of inpatient and outpatient service claims for persons with employer-sponsored health insurance coverage and their dependents. This analysis was restricted to adults 18 years of age and older with continuous enrollment in a commercial or Medicare Supplemental plan for at least one calendar year during the study period (a 45-day gap in coverage was allowed) who received outpatient prescription drug claims data feeds. Claims for hepatitis C antibody testing were identified using Current Procedural Terminology (CPT) codes (80074, 86803). We defined the annual hepatitis C testing rate as the number of patients with an HCV antibody test claim divided by the total number of study-eligible enrollees in a given calendar year. Testing rates were calculated for persons born between 1945 and 1965 and all other adults.There were 54,298,561 unique adults who were continuously enrolled for at least one calendar year during the study period. Among these, 4,629,040 (9%) had one or more inpatient or outpatient service claim with a CPT code for hepatitis C antibody testing during the study period. The overall estimated annual testing rate increased from 2.2% in 2011 to 5.3% in 2017. The testing rate increased from 1.7% to 7.8% among the 1945â1965 birth cohort and 2.5% to 4.0% in other birth cohorts. The average annual percent change in testing was 30.1% among the 1945â1965 birth cohort and 8.2% among other birth cohorts. Testing rate increased markedly (64.1%) between 2016 and 2017 in the 1945â1965 birth cohort, but not in other birth cohorts (7.7%).In this sample of individuals covered by commercial insurance, hepatitis C testing rates have increased slowly between 2011 and 2016. In 2017, there was a substantial increase in testing rates among the Baby Boomer cohort due most likely to an increase in awareness of CDC and USPSTF recommendations by both providers and individual patients associated with CDC health promotion efforts and increased marketing efforts by drug manufacturers. Efforts should continue to promote and increase the awareness of these recommendations and have people tested and treated for HCV.How the Moderator Intends to Engage the Audience in Discussions on the TopicThis panel will discuss strengths and weaknesses for monitoring hepatitis C testing using alternative data sources including self-reported data, insurance claims data, and laboratory testing data.
Trend analysis in hepatitis C testing, OptumLabsÂź Data Warehouse, 2011â2017
ObjectiveUsing administrative claims for privately insured and Medicare Advantage enrollees from a large, private, U.S. health plan, we estimated the prevalence of hepatitis C testing among individuals who were recommended to be tested (i.e., baby boomer cohort born between 1945 and 1965) by the CDC and United States Preventive Services Task Force. This panel will discuss strengths and weaknesses for monitoring hepatitis C testing using alternative data sources including self-reported data, insurance claims data, and laboratory testing data.IntroductionHepatitis C virus (HCV) infection is the most common blood-borne disease in the US and the leading cause of liver-related morbidity and mortality. Approximately 3.5 million individuals in the US were estimated to be living with HCV in 2010 and approximately half of them were unaware that they were currently infected. Among HCV infected individuals, those born between 1945 and 1965 (usually referred to as the baby boomer cohort) represents approximately 75% of current cases. Because of the substantial burden of disease among this age group, CDC expanded its existing HCV risk-based testing recommendations to include a one-time HCV antibody test for all persons born between 1945-1965. The United States Preventive Services Task Force (USPSTF) subsequently made the same recommendation in June 2013.MethodsWe obtained health plan enrollment information and claims data from the 2011 - 2017 OptumLabsÂź Data Warehouse, and utilized data from patients enrolled in either commercially insured programs or Medicare Advantage. We examined trends in HCV testing for the birth cohort born between 1945 and 1965 and compared their trend in testing to individuals who were not in the birth cohort. We developed two different estimates for HCV testing incidence in order to make comparisons to other commercial claims datasets. The denominator for both estimates was the number of adults continuously enrolled in one or more health plan(s) in a given calendar year (allowing up to a 45-day gap in coverage). The numerator for the first estimate was the number of people receiving any HCV related test in the current calendar year who had not received any HCV related test including HCV antibody test, HCV RNA test or HCV genotype test in the previous calendar years. The numerator for the second estimate was the number of people who were given an HCV antibody test (CPT: 86803 and 80074) in a given calendar year, irrespective of previous testing history.ResultsDuring the study period 2011 - 2017, there were 20,332,848 unique adults who met the inclusion criteria in the OptumLabsÂź data. Approximately 7.1 million (35.0%) of these individuals were born between 1945 and 1965. On average, there were approximately 2.8 million birth cohort enrollees for any given calendar year. For the birth cohort, the annual incidence of HCV testing was about 2% per year during the time period between 2008 and 2011 (data not shown). In general, between 2011 and 2017, the trends in testing rates were consistent across both estimation methods. Specifically for the birth cohort, the HCV testing rate increased substantially between 2012 and 2017, peaking in 2017 at 8.56% [95% CI: 8.53-8.59%] and 10.24% [95% CI: 10.21-10.27%]. The greatest increase occurred between 2016 and 2017 when the testing rate almost doubled. In contrast, for the non-birth cohort, the HCV testing rate started in 2012 at a rate similar to the birth cohort but did not increase in a similar fashion and did not see a substantial increase in HCV testing in 2016 or 2017.ConclusionsSince CDC and USPSTF recommended universal testing for the birth cohort in 2012 and 2013, respectively, hepatitis C testing rates have been increasing across all age groups. The rate of increase for the birth cohort was substantially greater than that for the non-birth cohort. CDC and USPSTF recommendations are likely a strong contributing factor impacting hepatitis C testing rates in the US. Efforts to promote hepatitis C testing should continue.