Pennsylvania State University

About: Pennsylvania State University is a education organization based out in State College, Pennsylvania, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 79763 authors who have published 196876 publications receiving 8318601 citations. The organization is also known as: Penn State & PSU.

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015

Abstract: Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ‘accidental cell death’ (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. ‘Regulated cell death’ (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death.

Peer Relationships, Child Development, and Adjustment: A Developmental Psychopathology Perspective

Abstract: and distant from their actions. Children will not only match or imitate the pretend acts of other children but also attempt to recruit the partner to join their pretend play. These efforts are not routinely successful, but it is clear that children are beginning to understand that nonliteral meanings can be shared by partners. From 21 to 24 months, children engage in similar pretend actions in the context of broader joint activity. Attempts to recruit others into pretense are more frequent and more successful. Although children organize materials for sociodramatic play, there is little or no joint organization of the pretend play itself. Scripted joint play emerges from 25 to 30 months, and the assignment of social roles in play (e.g., doctor, mother, father, police officer) emerges shortly thereafter, from 31 to 36 months. At this point, children understand that nonliteral meaning can be shared and they can communicate these meanings effectively during pretense with partners.

Galaxy Clustering in the Completed SDSS Redshift Survey: The Dependence on Color and Luminosity

Abstract: We measure the luminosity and color dependence of galaxy clustering in the largest-ever galaxy redshift survey, the main galaxy sample of the Sloan Digital Sky Survey (SDSS) Seventh Data Release (DR7). We focus on the projected correlation function wp(rp) of volume-limited samples, extracted from the parent sample of ∼ 700,000 galaxies over 8000 deg 2 , extending up to redshift of 0.25. We interpret our measurements using halo occupation distribution (HOD) modeling assuming aCDM cosmol- ogy (inflationary cold dark matter with a cosmological constant). The amplitude of wp(rp) grows slowly with luminosity for L L) × (�8/0.8) = 1.06 + 0.21(L/L∗) 1.12 , where L is the sample luminosity threshold. At fixed luminosity, redder galaxies exhibit a higher amplitude and steeper correlation function, a steady trend that runs through the "blue cloud" and "green valley" and continues across the "red sequence." The cross-correlation of red and blue galaxies is close to the geometric mean of their auto- correlations, dropping slightly below at rp 4L∗, but the lowest luminosity red galaxies (0.04−0.25L∗) show very strong clustering on small scales (rp < 2h −1 Mpc). Most of the observed trends can be naturally understood within theCDM+HOD framework. The growth of wp(rp) for higher luminosity galaxies reflects an overall shift in the mass scale of their host dark matter halos, in particular an increase in the minimum host halo mass Mmin. The mass at which a halo has, on average, one satellite galaxy brighter than L is M1 ≈ 17Mmin(L) over most of the luminosity range, with a smaller ratio above L∗. The growth and steepening of wp(rp) for redder galaxies reflects the increasing fraction of galaxies that are satellite systems in high mass halos instead of central systems in low mass halos, a trend that is especially marked at low luminosities. Our exten- sive measurements, provided in tabular form, will allow detailed tests of theoretical models of galaxy formation, a firm grounding of semi-empirical models of the galaxy population, and new constraints on cosmological parameters from combining real-space galaxy clustering with mass-sensitive statistics such as redshift-space distortions, cluster mass-to-light ratios, and galaxy-galaxy lensing. Subject headings: cosmology: observations — cosmology: theory — galaxies: distances and redshifts — galaxies: halos — galaxies: statistics — large-scale structure of universe

The origin and evolution of model organisms.

Abstract: The phylogeny and timescale of life are becoming better understood as the analysis of genomic data from model organisms continues to grow. As a result, discoveries are being made about the early history of life and the origin and development of complex multicellular life. This emerging comparative framework and the emphasis on historical patterns is helping to bridge barriers among organism-based research communities.