Adjustment to college among trauma survivors: An exploratory study of resilience

Researchers have examined students\u27 adjustment to college—why some students make the transition successfully, whereas others struggle or leave school after only a short time (e.g., Ezezek, 1994; Holmbek & Wandrei, 1993). Efforts to support students through this transition must draw upon a more complete understanding of variables that place students at risk for a stressful transition and protective factors that promote positive adaptation. Recent research has been focused on both individual and contextual variables including gender, racial identity, coping strategies, stress, social support and attachment (Feenstra, Banyard, Rines, & Hopkins, 2000; Klasner & Pistole, 2003; Pritchard & Wilson, 2003) and suggests the need for more research that goes beyond explaining academic success from demographic and academic variables (Pritchard & Wilson, p. 18). The current study is an examination of a group of students potentially at risk for a stressful transition to college: students who are survivors of traumatic stress. For the purposes of this research, trauma is defined broadly as a range of events that overwhelm an individual\u27s coping capacities and involves threats of serious injury or death to self or someone close to the individual (e.g., Pynoos, 1993). This examination was of variation in the transition to college among a sample of trauma survivors, of the roles of social relationships and supports, coping, and making meaning of the trauma in explaining variance in resilience in adjusting to college

How the Justice System Responds to Juvenile Victims: A Comprehensive Model.

The justice system handles thousands of cases involving juvenile victims each year. These victims are served by a complex set of agencies and institutions, including police, prosecutors, courts, and child protection agencies. Despite the many cases involving juvenile victims and the structure in place for responding to them, the juvenile victim justice system model presented in this Bulletin is a new concept. Although the juvenile victim justice system has a distinct structure and sequence, its operation is not very well understood. Unlike the more familiar juvenile offender justice system, the juvenile victim justice system has not been conceptualized as a whole or implemented by a common set of statutes. This Bulletin identifies the major elements of the juvenile victim justice system by delineating how cases move through the system. It reviews each step in the case flow process for the child protection and criminal justice systems and describes the interaction of the agencies an individuals involved. Recognizing how the juvenile victim justice system works can inform policy decisions and improve outcomes for juvenile victims. Acknowledging the existence of the system has important implications for system integration, information sharing, and data collection—all of which play a key role in ensuring the safety and well-being of juvenile victims

Stretching an heteropolymer

We study the influence of some quenched disorder in the sequence of monomers on the entropic elasticity of long polymeric chains. Starting from the Kratky-Porod model, we show numerically that some randomness in the favoured angles between successive segments induces a change in the elongation versus force characteristics, and this change can be well described by a simple renormalisation of the elastic constant. The effective coupling constant is computed by an analytic study of the low force regime.Comment: Latex, 7 pages, 3 postscript figur

Non-uniqueness in conformal formulations of the Einstein constraints

Standard methods in non-linear analysis are used to show that there exists a parabolic branching of solutions of the Lichnerowicz-York equation with an unscaled source. We also apply these methods to the extended conformal thin sandwich formulation and show that if the linearised system develops a kernel solution for sufficiently large initial data then we obtain parabolic solution curves for the conformal factor, lapse and shift identical to those found numerically by Pfeiffer and York. The implications of these results for constrained evolutions are discussed.Comment: Arguments clarified and typos corrected. Matches published versio

Osmotic pressure induced coupling between cooperativity and stability of a helix-coil transition

Most helix-coil transition theories can be characterized by a set of three parameters: energetic, describing the (free) energy cost of forming a helical state in one repeating unit; entropic, accounting for the decrease of entropy due to the helical state formation; and geometric, indicating how many repeating units are affected by the formation of one helical state. Depending on their effect on the helix-coil transition, solvents or co-solutes can be classified with respect to their action on these parameters. Solvent interactions that alter the entropic cost of helix formation by their osmotic action can affect both the stability (transition temperature) and the cooperativity (transition interval) of the helix-coil transition. A consistent inclusion of osmotic pressure effects in a description of helix-coil transition for poly(L-glutamic acid) in solution with polyethylene glycol can offer an explanation of the experimentally observed linear dependence of transition temperature on osmotic pressure as well as the concurrent changes in the cooperativity of the transition.Comment: 5 pages, 3 figures. To be submitted to Phys.Rev.Let

Master equation approach to DNA-breathing in heteropolymer DNA

After crossing an initial barrier to break the first base-pair (bp) in double-stranded DNA, the disruption of further bps is characterized by free energies between less than one to a few kT. This causes the opening of intermittent single-stranded bubbles. Their unzipping and zipping dynamics can be monitored by single molecule fluorescence or NMR methods. We here establish a dynamic description of this DNA-breathing in a heteropolymer DNA in terms of a master equation that governs the time evolution of the joint probability distribution for the bubble size and position along the sequence. The transfer coefficients are based on the Poland-Scheraga free energy model. We derive the autocorrelation function for the bubble dynamics and the associated relaxation time spectrum. In particular, we show how one can obtain the probability densities of individual bubble lifetimes and of the waiting times between successive bubble events from the master equation. A comparison to results of a stochastic Gillespie simulation shows excellent agreement.Comment: 12 pages, 8 figure

Trapped Surfaces in Vacuum Spacetimes

An earlier construction by the authors of sequences of globally regular, asymptotically flat initial data for the Einstein vacuum equations containing trapped surfaces for large values of the parameter is extended, from the time symmetric case considered previously, to the case of maximal slices. The resulting theorem shows rigorously that there exists a large class of initial configurations for non-time symmetric pure gravitational waves satisfying the assumptions of the Penrose singularity theorem and so must have a singularity to the future.Comment: 14 page

Initial data for fluid bodies in general relativity

We show that there exist asymptotically flat almost-smooth initial data for Einstein-perfect fluid's equation that represent an isolated liquid-type body. By liquid-type body we mean that the fluid energy density has compact support and takes a strictly positive constant value at its boundary. By almost-smooth we mean that all initial data fields are smooth everywhere on the initial hypersurface except at the body boundary, where tangential derivatives of any order are continuous at that boundary. PACS: 04.20.Ex, 04.40.Nr, 02.30.JrComment: 38 pages, LaTeX 2e, no figures. Accepted for publication in Phys. Rev.

Gating-by-tilt of mechanosensitive membrane channels

We propose an alternative mechanism for the gating of biological membrane channels in response to membrane tension that involves a change in the slope of the membrane near the channel. Under biological membrane tensions we show that the energy difference between the closed (tilted) and open (untilted) states can far exceed kBT and is comparable to what is available under simple ilational gating. Recent experiments demonstrate that membrane leaflet asymmetries (spontaneous curvature) can strong effect the gating of some channels. Such a phenomenon would be more easy to explain under gating-by-tilt, given its novel intrinsic sensitivity to such asymmetry.Comment: 10 pages, 2 figure

Effect of Lipid Characteristics on the Structure of Transmembrane Proteins

AbstractThe activity of embedded proteins is known to vary with lipid characteristics. Indeed, it has been shown that some cell-membrane proteins cannot function unless certain non-bilayer-forming lipids (i.e., nonzero spontaneous curvature) are present. In this paper we show that membranes exert a line tension on transmembrane proteins. The line tension, on the order of 1–100kT/protein, varies with the lipid properties and the protein configuration. Thus, membranes composed of different lipids favor different protein conformations. Model predictions are in excellent agreement with the data of Keller et al. (Biophys. J. 1993, 65:23–27) regarding the conductance of alamethicin channels