115 research outputs found
Holographic multiverse and the measure problem
We discuss the duality, conjectured in earlier work, between the wave
function of the multiverse and a 3D Euclidean theory on the future boundary of
spacetime. In particular, we discuss the choice of the boundary metric and the
relation between the UV cutoff scale xi on the boundary and the hypersurfaces
Sigma on which the wave function is defined in the bulk. We propose that in the
limit of xi going to 0 these hypersurfaces should be used as cutoff surfaces in
the multiverse measure. Furthermore, we argue that in the inflating regions of
spacetime with a slowly varying Hubble rate H the hypersurfaces Sigma are
surfaces of constant comoving apparent horizon (CAH). Finally, we introduce a
measure prescription (called CAH+) which appears to have no pathological
features and coincides with the constant CAH cutoff in regions of slowly
varying H.Comment: A minor change: the discussion of unitarity on p.9 is clarifie
Empirical Evidence on the Use of Credit Scoring for Predicting Insurance Losses with Psycho-social and Biochemical Explanations
An important development in personal lines of insurance in the United States is the use of credit history data for insurance risk classification to predict losses. This research presents the results of collaboration with industry conducted by a university at the request of its state legislature. The purpose was to see the viability and validity of the use of credit scoring to predict insurance losses given its controversial nature and criticism as redundant of other predictive variables currently used. Working with industry and government, this study analyzed more than 175,000 policyholders’ information for the relationship between credit score and claims. Credit scores were significantly related to incurred losses, evidencing both statistical and practical significance. We investigate whether the revealed relationship between credit score and incurred losses was explainable by overlap with existing underwriting variables or whether the credit score adds new information about losses not contained in existing underwriting variables. The results show that credit scores contain significant information not already incorporated into other traditional rating variables (e.g., age, sex, driving history). We discuss how sensation seeking and self-control theory provide a partial explanation of why credit scoring works (the psycho-social perspective). This article also presents an overview of biological and chemical correlates of risk taking that helps explain why knowing risk-taking behavior in one realm (e.g., risky financial behavior and poor credit history) transits to predicting risk-taking behavior in other realms (e.g., automobile insurance incurred losses). Additional research is needed to advance new nontraditional loss prediction variables from social media consumer information to using information provided by technological advances. The evolving and dynamic nature of the insurance marketplace makes it imperative that professionals continue to evolve predictive variables and for academics to assist with understanding the whys of the relationships through theory development.IC2 Institut
Out of equilibrium: understanding cosmological evolution to lower-entropy states
Despite the importance of the Second Law of Thermodynamics, it is not
absolute. Statistical mechanics implies that, given sufficient time, systems
near equilibrium will spontaneously fluctuate into lower-entropy states,
locally reversing the thermodynamic arrow of time. We study the time
development of such fluctuations, especially the very large fluctuations
relevant to cosmology. Under fairly general assumptions, the most likely
history of a fluctuation out of equilibrium is simply the CPT conjugate of the
most likely way a system relaxes back to equilibrium. We use this idea to
elucidate the spacetime structure of various fluctuations in (stable and
metastable) de Sitter space and thermal anti-de Sitter space.Comment: 27 pages, 11 figure
Avaliação da albuminúria e da eletroforese de proteÃnas urinárias de cães com hiperadrenocorticismo e a relação com a pressão arterial sistêmica
O hiperadrenocorticismo é uma das endocrinopatias mais comuns em cães, sendo caracterizado pela exposição excessiva de glicocorticóides secretados pelas adrenais. A hipercortisolemia crônica pode promover várias complicações, incluindo hipertensão sistêmica e glomerulonefrite. A glomerulonefrite pode desencadear variáveis graus de proteinúria e uma tendência de evolução para doença renal crônica. A perda de proteÃnas na urina, principalmente da albumina, é uma caracterÃstica das doenças glomerulares e a determinação de variáveis laboratoriais, como a razão proteÃna:creatinina urinária (RPC), albuminúria (teste de ELISA) e eletroforese das proteÃnas urinárias, são recomendadas para a elucidação do diagnóstico. Assim, o objetivo do estudo é avaliar a relação entre proteinúria e hipertensão arterial sistêmica em cães com hiperadrenocorticismo e verificar, pela avaliação da albuminúria e do peso molecular das proteÃnas urinárias, o segmento do néfron que foi comprometido ou lesado. Foram avaliados 30 cães com diagnóstico de hiperadrenocorticismo, subdivididos em 13 cães com hipertensão arterial sistêmica (grupo I) e 17 cães normotensos (grupo II). Foram determinados a RPC; a albuminúria pela avaliação da albumina normalizada e razão albumina:creatinina urinária (RAC) e a eletroforese de proteÃnas pela técnica em gel de poliacrilamida, contendo dodecil sulfato de sódio (SDS-PAGE). Os resultados foram comparados com os dados obtidos de 30 cães clinicamente saudáveis. Foi constatado que não houve influência da hipertensão arterial sistêmica nos cães com hiperadrenocorticismo em relação à quantificação da albuminúria, determinada pelo método ELISA, e nem na qualidade e quantidade das bandas de proteÃnas de baixo (60 kDa). No entanto foi determinado que cães com hiperadrenocorticismo podem desenvolver lesões glomerulares e tubulares, caracterizadas pela presença de albuminúria e de proteÃnas de alto e de baixo pesos moleculares, independentemente da presença de hipertensão arterial sistêmica. Conclui-se que a avaliação quantitativa (RPC e RAC) e qualitativa (SDS-PAGE) das proteÃnas urinárias traz informações adicionais que indicam os possÃveis segmentos comprometidos dos néfrons que causaram as perdas de proteÃnas na urina
Higher cortisol:cortisone ratios in the preovulatory follicle of completely unstimulated IVF cycles indicate oocytes with increased pregnancy potential
BACKGROUND: Conception following gonadotrophin-stimulated IVF and embryo transfer has been associated with a higher intrafollicular cortisol:cortisone ratio and decreased metabolism of cortisol to cortisone. The role of glucocorticoids in human oocyte maturation is not fully understood, but active glucocorticoid (cortisol) may be important. This study relates intrafollicular cortisol and cortisone concentrations to oocyte fertilization and embryo implantation in unstimulated cycles. METHODS: Patients aged <40 years with favourable sperm underwent unstimulated IVF–embryo transfer. Study 1 related intrafollicular cortisol levels to oocyte and IVF outcome: (i) fertilized, pregnant (n = 9); (ii) fertilized, not pregnant (n = 21); and (iii) unfertilized (n = 12). Study 2 was a case–control study of 27 patients (same outcome groups of equal size) which measured intrafollicular cortisol, cortisone and the cortisol:cortisone ratio. RESULTS: Conception cycles demonstrated higher cortisol concentrations compared with the fertilized group (study 1) [median (95% confidence interval): 299 (249–330) versus 227 nmol/l (185–261); P < 0.05] and higher cortisol:cortisone ratios when compared with the unfertilized group (study 2) [7.38 (5.23–9.19) versus 3.56 (1.75–7.46) respectively; P = 0.02]. Of the women with cortisol:cortisone ratios greater than the outcome independent mean of 5.90, 58% conceived compared with only 13% with ratios <5.90 (P < 0.02). CONCLUSION: Higher cortisol:cortisone ratios in conception cycles suggest that active glucocorticoid may be important for final oocyte maturation and embryo implantation in unstimulated cycles
- …