An Empirical Study of Price Correlations: 2. The Decrease in Price Correlation with Distance and the Concept of Correlation Length
The dependence of the correlation between wheat price fluctuations on different markets with respect to the distance between those markets is investigated. It is shown that the decrease in the correlation is exponential and is governed by a characteristic distance which is called the correlation length for wheat prices. This is a measure of the level of market integration in a given area. The magnitude of the correlation length is compared for different cereals: wheat, rye, and oats, and the evolution of the correlation length during the 19th century is studied. In particular, it is observed that subsistence crises are characterised by a collective behaviour of the economy which results in a sudden peak in the correlation length. Last, the part played by the spatial correlation between precipitations is investigated. It appears to be rather small; consequently, the price-correlation length is primarily the result of economic factors.
Unraveling the Allosteric Mechanism of Four Cancer-related Mutations in the Disruption of p53-DNA Interaction.
The p53 protein plays active roles in the physiological regulation of cell cycle as well as in cancer developments. In more than half of human cancers, the protein is inactivated by mutations located primarily in its DNA-binding domain (DBD), and some mutations located in the β-sandwich region of DBD are reported to decrease p53-DNA binding affinities. To understand the long-range correlation between p53 β-sandwich and DNA, and the allosteric mechanism of β-sandwich mutations in the disruption of p53-DNA interactions, we first identify three regions with a strong correlation with DNA based on microsecond molecular dynamics (MD) simulations of wild-type p53-DNA complex and then perform multiple MD simulations on four cancer-related mutants L145Q, P151S, Y220C, and G266R, which are located in these three regions. Our simulations show that these mutations allosterically destabilize the structural stability of the DNA-binding groove in p53 and disrupt the p53-DNA interactions. Network analyses reveal optimal correlation paths through which the mutation-induced allosteric signal passes to DNA, and the disturbance effect of these mutations on the global connectivity and dynamical correlation of the p53-DNA complex. This work paves the way for the in-depth understanding of the mutation-induced loss in p53's DNA-recognition ability and the pathological mechanism of cancer development.
Test security in medicolegal cases: proposed guidelines for attorneys utilizing neuropsychology practice.
In the context of forensic neuropsychological assessments, the professional interaction of law and psychology is viewed primarily as one where the retaining attorney or court dictates its needs to psychologists when resolving legal disputes. While this perspective is conceptually accurate, the positive and practical collaboration of law and psychology also relies on attorneys adhering to basic protections of sensitive psychological assessment procedures and tests. Objective testing is undermined when a practitioner of law engages in actions prior to, during, or following a neuropsychological examination in a manner that threatens the test security. An appreciation among practitioners of law and psychology regarding the necessity of test security is essential. This article reviews attorney actions that can affect test security, proposes a distinction by psychology between appropriate and problematic client preparation for a neuropsychological examination, integrates the available legal precedent regarding test security, and suggests productive measures to protect test security in medicolegal settings.