Momentum Distribution in Nuclear Matter and Finite Nuclei

A simple method is presented to evaluate the effects of short-range correlations on the momentum distribution of nucleons in nuclear matter within the framework of the Green's function approach. The method provides a very efficient representation of the single-particle Green's function for a correlated system. The reliability of this method is established by comparing its results to those obtained in more elaborate calculations. The sensitivity of the momentum distribution on the nucleon-nucleon interaction and the nuclear density is studied. The momentum distributions of nucleons in finite nuclei are derived from those in nuclear matter using a local-density approximation. These results are compared to those obtained directly for light nuclei like $^{16}O$.Comment: 17 pages REVTeX, 10 figures ps files adde

A Semiparametric Method for Estimating Local House Price Indices

Spatial autoregressive hedonic models utilize house prices lagged in space and time to produce local house price indices, for example, the spatial and temporal autoregressive (STAR) model might be used this way. This paper complements these models with a semiparametric approach, the Local Regression Model (LRM). The greater flexibility of the LRM may allow it to identify space-time asymmetries missed by other models. The LRM is fitted to 49,511 sales from 1972Q1 to 1991Q2 in Fairfax County, Virginia. The local price indices display plausible and significant variations over space and time. The LRM price indices in selected neighborhoods are shown to differ significantly from those in some other neighborhoods. A new method for estimating standard errors addresses an overlooked problem common to all local price indices: how to evaluate the amount of noise in the estimates. Out-of-sample prediction errors demonstrate that LRM adds significant information to the hedonic model. Copyright 2004 by the American Real Estate and Urban Economics Association

CHCHD10 mutations p. R15L and p. G66V cause motoneuron disease by haploinsufficiency.

Mutations in the mitochondrially located protein CHCHD10 cause motoneuron disease by an unknown mechanism. In this study, we investigate the mutations p. R15L and p. G66V in comparison to wild-type CHCHD10 and the non-pathogenic variant p. P34S in vitro, in patient cells as well as in the vertebrate in vivo model zebrafish. We demonstrate a reduction of CHCHD10 protein levels in p. R15L and p. G66V mutant patient cells to approximately 50%. Quantitative real-time PCR revealed that expression of CHCHD10 p. R15L, but not of CHCHD10 p. G66V, is already abrogated at the mRNA level. Altered secondary structure and rapid protein degradation are observed with regard to the CHCHD10 p. G66V mutant. In contrast, no significant differences in expression, degradation rate or secondary structure of non-pathogenic CHCHD10 p. P34S are detected when compared with wild-type protein. Knockdown of CHCHD10 expression in zebrafish to about 50% causes motoneuron pathology, abnormal myofibrillar structure and motility deficits in vivo. Thus, our data show that the CHCHD10 mutations p. R15L and p. G66V cause motoneuron disease primarily based on haploinsufficiency of CHCHD10

Promoting family: A contingency model of family business succession

Succession is a challenge to family businesses for a number of reasons, including the need to address the issue of intergenerational handover. This article focuses on one aspect of succession in family business by investigating when family members are preferred as successors. Results from 860 family businesses indicate that specific (tacit) knowledge characteristics combined with a favorable transaction atmosphere, in certain contexts, make a family member the most suitable successor. A conceptual model is presented that outlines when inside-family succession is preferred