Stony Brook University

About: Stony Brook University is a education organization based out in Stony Brook, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 32534 authors who have published 68218 publications receiving 3035131 citations. The organization is also known as: State University of New York at Stony Brook & SUNY Stony Brook.

PIP2 and Proteins: Interactions, Organization, and Information Flow

Abstract: ▪ Abstract We review the physical properties of phosphatidylinositol 4,5-bisphosphate (PIP2) that determine both its specific interactions with protein domains of known structure and its nonspecific electrostatic sequestration by unstructured domains. Several investigators have postulated the existence of distinct pools of PIP2 within the cell to account for the myriad functions of this lipid. Recent experimental work indicates certain regions of the plasma membrane—membrane ruffles and nascent phagosomes—do indeed concentrate PIP2. We consider two mechanisms that could account for this phenomenon: local synthesis and electrostatic sequestration. We conclude by considering the hypothesis that proteins such as MARCKS bind a significant fraction of the PIP2 in a cell, helping to sequester it in lateral membrane domains, then release this lipid in response to local signals such as an increased concentration of Ca++/calmodulin or activation of protein kinase C.

The influence of suggestion on suicide: substantive and theoretical implications of the Werther effect.

Abstract: This paper shows that suicides increase immediately after a suicide story has been publicized in the newspapers in Britain and in the United States, 1947-1968. The more publicity devoted to a suicide story, the larger the rise in suicides thereafter. The rise in suicides after a story is restricted mainly to the area in which the story was publicized. Alternative explanations of these findings are examined; the evidence indicates that the rise in suicides is due to the influence of suggestion on suicide, an influence not previously demonstrated on the national level of suicides. The substantive, theoretical, and methodological implications of these findings are examined.

The equation of state from observed masses and radii of neutron stars

Abstract: We determine an empirical dense matter equation of state (EOS) from a heterogeneous data set of six neutron stars: three Type-I X-ray bursters with photospheric radius expansion, studied by ?zel et?al., and three transient low-mass X-ray binaries. We critically assess the mass and radius determinations from the X-ray burst sources and show explicitly how systematic uncertainties, such as the photospheric radius at touchdown, affect the most probable masses and radii. We introduce a parameterized EOS and use a Markov chain Monte Carlo algorithm within a Bayesian framework to determine nuclear parameters such as the incompressibility and the density dependence of the bulk symmetry energy. Using this framework we show, for the first time, that these parameters, predicted solely on the basis of astrophysical observations, all lie in ranges expected from nuclear systematics and laboratory experiments. We find significant constraints on the mass-radius relation for neutron stars, and hence on the pressure-density relation of dense matter. The predicted symmetry energy and the EOS near the saturation density are soft, resulting in relatively small neutron star radii around 11-12?km for M = 1.4 M ?. The predicted EOS stiffens at higher densities, however, and our preferred model for X-ray bursts suggests that the neutron star maximum mass is relatively large, 1.9-2.2 M ?. Our results imply that several commonly used equations of state are inconsistent with observations.