444 research outputs found
Holographic Principle bounds on Primordial Black Hole abundances
The generalized Second Law of thermodynamics and the Holographic Principle
are combined to obtain the maximum mass of black holes formed inside a static
spherical box of size filled with radiation at initial temperature .
The final temperature after the formation of black holes is evaluated, and we
show that a critical threshold exists for the radiation to be fully consumed by
the process. We next argue that if some form of Holographic Principle holds,
upper bounds to the mass density of PBHs formed in the early universe may be
obtained. The limits are worked out for inflationary and non-inflationary
cosmological models. This method is independent of the known limits based on
the background fluxes (from cosmic rays, radiation and other forms of energy)
and applies to potentially important epochs of PBH formation, resulting in
quite strong constraints to .Comment: Latex file, 2 .ps figures. To appear in Classical and Quantum Gravit
Political Regimes and Sovereign Credit Risk in Europe, 1750-1913
This article uses a new panel data set to perform a statistical analysis of political regimes and sovereign credit risk in Europe from 1750 to 1913. Old Regime polities typically suffered from fiscal fragmentation and absolutist rule. By the start of World War I, however, many such countries had centralized institutions and limited government. Panel regressions indicate that centralized and?or limited regimes were associated with significant improvements in credit risk relative to fragmented and absolutist ones. Structural break tests also reveal close relationships between major turning points in yield series and political transformations
The effect on melanoma risk of genes previously associated with telomere length.
Telomere length has been associated with risk of many cancers, but results are inconsistent. Seven single nucleotide polymorphisms (SNPs) previously associated with mean leukocyte telomere length were either genotyped or well-imputed in 11108 case patients and 13933 control patients from Europe, Israel, the United States and Australia, four of the seven SNPs reached a P value under .05 (two-sided). A genetic score that predicts telomere length, derived from these seven SNPs, is strongly associated (P = 8.92x10(-9), two-sided) with melanoma risk. This demonstrates that the previously observed association between longer telomere length and increased melanoma risk is not attributable to confounding via shared environmental effects (such as ultraviolet exposure) or reverse causality. We provide the first proof that multiple germline genetic determinants of telomere length influence cancer risk.This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/jnci/dju26
Insulin/IGF and Sex Hormone Axes in Human Endometrium and Associations with Endometrial Cancer Risk Factors
Given an ordered set of points and an ordered set of geometric objects in the plane, we are interested in finding a non-crossing matching between point-object pairs. In this paper, we address the algorithmic problem of determining whether a non-crossing matching exists between a given point-object pair. We show that when the objects we match the points to are finite point sets, the problem is NP-complete in general, and polynomial when the objects are on a line or when their size is at most 2. When the objects are line segments, we show that the problem is NP-complete in general, and polynomial when the segments form a convex polygon or are all on a line. Finally, for objects that are straight lines, we show that the problem of finding a min-max non-crossing matching is NP-complete. © 2012 Elsevier B.V.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Genome-wide meta-analysis identifies five new susceptibility loci for cutaneous malignant melanoma.
Thirteen common susceptibility loci have been reproducibly associated with cutaneous malignant melanoma (CMM). We report the results of an international 2-stage meta-analysis of CMM genome-wide association studies (GWAS). This meta-analysis combines 11 GWAS (5 previously unpublished) and a further three stage 2 data sets, totaling 15,990 CMM cases and 26,409 controls. Five loci not previously associated with CMM risk reached genome-wide significance (P < 5 × 10(-8)), as did 2 previously reported but unreplicated loci and all 13 established loci. Newly associated SNPs fall within putative melanocyte regulatory elements, and bioinformatic and expression quantitative trait locus (eQTL) data highlight candidate genes in the associated regions, including one involved in telomere biology.[Please see the Supplementary Note for acknowledgments.]This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ng.337
The Basilicata Wealth Fund: Resource Policy and Long-Run Economic Development in Southern Italy
This paper contributes to the growing political economy literature of within-country natural resources management, by proposing a new resource policy for the oil-rich southern Italian region of Basilicata. The policy proposal is to establish a (regional) wealth fund in which all the royalty revenues from non-renewable natural resource exploitation in Basilicata would be stored and fully converted into low-risk financial assets. The scope is to give priority to long-run investments as to better exploit revenues from large-scale extraction of natural capital. Establishing a wealth fund at the regional sub-national level is a novel approach that can be applied to other resource-rich regions in the world. I label the fund as the Basilicata Wealth Fund (BWF). The BWF would be a regionally owned investment fund, however independently administered from national authorities (for instance, as an independent legal entity under the jurisdiction of the Bank of Italy). In addition, the paper posits a transparent and clear-cut spending fiscal rule in order to let regional authorities use the resource revenues to finance economic policy. The clear advantage from the BWF would be the stronger focus on long-run economic development and the higher accountability, hence avoiding misuse of resource revenues for myopic fiscal spending
Health utilities for non‐melanoma skin cancers and precancerous lesions: A systematic review
Background
Non-melanoma skin cancers (NMSCs) are common and consume many healthcare resources. A health utility is a single preference-based value for assessing health-related quality of life, which can be used in economic evaluations. There are scarce data on health utilities for NMSCs.
Objectives
Using a systematic review approach, we synthesized the current data on NMSC-related health utilities.
Methods
A systematic review of studies of NMSC-related health utilities was conducted in Medline, Embase, and Cochrane databases. Data were extracted based on the protocol and a quality assessment was performed for each study.
Results
The protocol resulted in 16 studies, involving 121 621 participants. Mean utility values across the studies ranged from 0.56 to 1 for undifferentiated NMSC, 0.84 to 1 for actinic keratosis, 0.45 to 1 for squamous cell carcinoma, and 0.67 to 1 for basal cell carcinoma. There was considerable variability in utilities by type of cancer, stage of diagnosis, time to treatment, treatment modality, and quality of life instrument or method. Utility values were predominantly based on the EuroQol 5-dimension instrument and ranged from 0.45 to 0.96, while other measurement methods produced values ranging from 0.67 to 1. Lower utility values were observed for advanced cancers and for the time period during and immediately after treatment, after which values gradually returned to pre-treatment levels.
Conclusions
Most utility values clustered around relatively high values of 0.8 to 1, suggesting small decrements in quality of life associated with most NMSCs and their precursors. Variability in utilities indicates that careful characterization is required for measures to be used in economic evaluations
Dietary glycaemic index, glycaemic load and endometrial and ovarian cancer risk: a systematic review and meta-analysis
Long-term consumption of a high glycaemic index (GI) or glycaemic load (GL) diet may lead to chronic hyperinsulinaemia, which is a potential risk factor for cancer. To date, many studies have examined the association between GI, GL and cancer risk, although results have been inconsistent, therefore our objective was to conduct a systematic review of the literature. Medline and Embase were systematically searched using terms for GI, GL and cancer to identify studies published before December 2007. Random effects meta-analyses were performed for endometrial cancer, combining maximally adjusted results that compared risk for those in the highest versus the lowest category of intake. Separate analysis examined risk by body mass index categories. Five studies examining GI and/or GL intake and endometrial cancer risk were identified. Pooled effect estimates for endometrial cancer showed an increased risk for high GL consumers (RR 1.20; 95% CI: 1.06–1.37), further elevated in obese women (RR 1.54; 95% CI: 1.18–2.03). No significant associations were observed for GI. Only two studies examined ovarian cancer and therefore no meta-analysis was performed, but results indicate positive associations for GL also. A high GL, but not a high GI, diet is positively associated with the risk of endometrial cancer, particularly among obese women
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