Attachment and Treatment Response for PTSD Patients

Attachment is an important factor to address with trauma patients. Using an inpatient, group therapy setting can enhance the impact of treatment, increase secure attachments with others, and reduce trauma symptoms.York’s Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected] www.researchimpact.c

Nanoscale assembly processes revealed in the nacroprismatic transition zone of Pinna nobilis mollusc shells

Intricate biomineralization processes in molluscs engineer hierarchical structures with meso-, nano-, and atomic architectures that give the final composite material exceptional mechanical strength and optical iridescence on the macroscale. This multiscale biological assembly inspires new synthetic routes to complex materials. Our investigation of the prism-nacre interface reveals nanoscale details governing the onset of nacre formation using high-resolution scanning transmission electron microscopy. A wedge polishing technique provides unprecedented, large-area specimens required to span the entire interface. Within this region, we find a transition from nanofibrillar aggregation to irregular early-nacre layers, to well-ordered mature nacre suggesting the assembly process is driven by aggregation of nanoparticles (~50-80 nm) within an organic matrix that arrange in fiber-like polycrystalline configurations. The particle number increases successively and, when critical packing is reached, they merge into early-nacre platelets. These results give new insights into nacre formation and particle-accretion mechanisms that may be common to many calcareous biominerals.Comment: 5 Figure

The effects of oestradiol-17beta on the synthesis of ribosomal proteins in the immature rat uterus

The effects of oestrogen on the immature rat uterus may be summarised as follows. The hormone, circulating in the bloodstream enters uterine cells and binds to a receptor. The hormone receptor complex binds to chromatin and this leads to quantitative and qualitative changes in transcription. Newly synthesised hnRNA matures to mRNA and is translated by pre-existing ribosomes in the cytoplasm. A small number of new proteins are synthesised which are required for the subsequent stimulation of RNA and protein synthesis. These proteins are required for the transcription of new rRNA and mRNA encoding ribosomal proteins. New polysomes are then assembled and are responsible for protein synthesis in the developing uterus. Changes in RNA and protein bring about tissue hypertrophy which is followed by DNA replication and cell division. The resulting growth and development of the tissue initiates its preparation for the possible implantation of a fertilised ovum. Studies of protein synthesis in the uterus responding to oestrogen have revealed that major changes in the gross protein population were not to be found. The changes oestrogens induced were altogether too subtle to be revealed by the crude analysis of total protein. Therefore, one group of oestrogen-induced proteins was selected for detailed study, namely the ribosomal proteins. Previous work had shown that the synthesis of these proteins coincided with the appearance of new polysomes in vivo. However, the small quantity of ribosomal proteins in the uterus relative to the whole body of the rat severely limited these studies, and thus it was decided to pursue further studies by the use of two different procedures in vitro. The first of these procedures required the incubation, with radio-labelled precursors, of whole uteri in vitro after oestrogen stimulation vivo. The uteri, removed from immature rats after various periods of oestrogen treatment, were incubated with either [3H]-leucine, [35S]-methionine or [32P]-phosphate. In this way, the synthesis of total ribosomal proteins, and the synthesis and post-translational modification of individual proteins could be analysed. It was found that oestrogen stimulated ribosomal protein synthesis vitro in the same way as in vivo and that the maximal incorporation of new ribosomal proteins into ribosomes coincided with maximal polysome assembly. Incorporation of radioactivity into ribosomal proteins of the unstimulated rat uterus was insignificant, except in the case of the large-subunit protein L10. Oestradiol treatment of rats at various times before death was followed by stimulated incorporation of radio-labelled precursor into individual ribosomal proteins in vitro. This stimulation was maximal 12 hours after hormone administration and could not be accounted for by increased pool sizes. It was possible to quantify the effect of oestradiol on 17 small subunit proteins and 16 large subunit proteins. Response to the hormone was not uniform and varied from 3-fold stimulation of synthesis of L10 to an almost 5-fold increase in the synthesis of protein L19. Incubation of uteri with [32P]-inorganic phosphate resulted in the labelling of 2 large subunit proteins and 1 protein of the small subunit. However, an apparent increase in the incorporation of label after oestrogen stimulation could be accounted for by changes in the size of precursor pools. A second analytical approach involved the isolation of active uterine polysomes and their subsequent translation in a cell free protein synthesisiing system. The synthesis of total proteins increased from control levels until 8-12 hours after oestrogen treatment and then declined to control levels once more. The proportion of ribosomal proteins synthesised in this system became nearly maximal at 2 hours and their synthesis remained a constant proportion of the total activity of uterine polysomes until polysome disassembly after 12 hours. An anti-ribosomal protein antibody was raised in rabbits and used to determine the antigenicity of uterine homogenate after oestrogen treatment of rats. The results produced by this analysis were unexpected in that they revealed an apparent decrease in antigenicity after 12 hours. This conflicted with the current idea of ribosome turnover requiring many days, but could be rationalised in terms of a pool of free ribosomal proteins becoming less antigenic as they were incorporated into ribonucleoprotein particles. These results were compared to other relevant work and discussed with a view to future studies

A checklist of zooplankters from the Gulf of the Farallones and off Northern California

Plankton samples were collected from January through June 1975-80 as part of the Dungeness Crab Research Program. Zooplankters were identified and enumerated from 1975-77 and 1979 samples taken in the Gulf of the Farallones and from 1979 samples off northern California. A checklist of zooplankters found in these samples is presented along with information on location, frequency of occurrence, and density. (57pp.

Methods and Apparatus for In Vivo Identification and Characterization of Vulnerable Atherosclerotic Plaques

Methods and apparatus for analyzing the chemical composition of vulnerable plaques with an intravascular catheter having a near-infrared light source, a fiber-optic probe, a mechanism for directing the light from the light source into a blood vessel, and detectors for detecting light reflected or scattered by the tissue. The light source may be a tunable laser, and may transmit an incident beam having a wavelength ranging from 1400 to 4100 nm. A computer may be included to receive and process the spectral data in the analysis of the vulnerable plaques. A catheter system may be configured to provide near-IR spectrometric imaging of arteries to non-destructively locate and determine lipid pool and fibrous cap size and composition. Additionally, mediators and cellular components may be also determined that are typically associated with vulnerable plaques which have an increased risk of rupture. The lipid pool, fibrous cap, and inflammatory response may serve as an in vivo marker for vulnerable atherosclerotic plaques. Methods are further provided for prospectively identifying and characterizing vulnerable plaques which may include the steps of focusing near-IR light onto a blood vessel wall; detecting the scattered light in the region; and analyzing the resulting spectra across the full preselected wavelength range, particularly in the ranges that include identifying peaks for vulnerable plaque constituents

Towards Gravitational Wave Signals from Realistic Core Collapse Supernova Models

We have computed the gravitational wave signal from supernova core collapse using the presently most realistic input physics available. We start from state-of-the-art progenitor models of rotating and non-rotating massive stars, and simulate the dynamics of their core collapse by integrating the equations of axisymmetric hydrodynamics together with the Boltzmann equation for the neutrino transport including an elaborate description of neutrino interactions, and a realistic equation of state. We compute the quadrupole wave amplitudes, the Fourier wave spectra, the amount of energy radiated in form of gravitational waves, and the S/N ratios for the LIGO and the tuned Advanced LIGO interferometers resulting both from non-radial mass motion and anisotropic neutrino emission. The simulations demonstrate that the dominant contribution to the gravitational wave signal is produced by neutrino-driven convection behind the supernova shock. For stellar cores rotating at the extreme of current stellar evolution predictions, the core-bounce signal is detectable with advanced LIGO up to a distance of 5kpc, whereas the signal from post-shock convection is observable up to a distance of about 100kpc. If the core is non-rotating its gravitational wave emission can be measured up to a distance of 15kpc, while the signal from the Ledoux convection in the deleptonizing, nascent neutron star can be detected up to a distance of 10kpc. Both kinds of signals are generically produced by convection in any core collapse supernova.Comment: 9 pages, 13 figures, Latex, submitted to ApJ, error in ps-file fixed; figures in full resolution are available upon reques

Analysis of Diffusion of Ras2 in Saccharomyces cerevisiae Using Fluorescence Recovery after Photobleaching

Binding, lateral diffusion and exchange are fundamental dynamic processes involved in protein association with cellular membranes. In this study, we developed numerical simulations of lateral diffusion and exchange of fluorophores in membranes with arbitrary bleach geometry and exchange of the membrane localized fluorophore with the cytosol during Fluorescence Recovery after Photobleaching (FRAP) experiments. The model simulations were used to design FRAP experiments with varying bleach region sizes on plasma-membrane localized wild type GFP-Ras2 with a dual lipid anchor and mutant GFP-Ras2C318S with a single lipid anchor in live yeast cells to investigate diffusional mobility and the presence of any exchange processes operating in the time scale of our experiments. Model parameters estimated using data from FRAP experiments with a 1 micron x 1 micron bleach region-of-interest (ROI) and a 0.5 micron x 0.5 micron bleach ROI showed that GFP-Ras2, single or dual lipid modified, diffuses as single species with no evidence of exchange with a cytoplasmic pool. This is the first report of Ras2 mobility in yeast plasma membrane. The methods developed in this study are generally applicable for studying diffusion and exchange of membrane associated fluorophores using FRAP on commercial confocal laser scanning microscopes.Comment: Accepted for publication in Physical Biology (2010). 28 pages, 7 figures, 3 table

Investigating the medium range order in amorphous Ta₂O₅ coatings

Ion-beam sputtered amorphous heavy metal oxides, such as Ta2O5, are widely used as the high refractive index layer of highly reflective dielectric coatings. Such coatings are used in the ground based Laser Interferometer Gravitational-wave Observatory (LIGO), in which mechanical loss, directly related to Brownian thermal noise, from the coatings forms an important limit to the sensitivity of the LIGO detector. It has previously been shown that heat-treatment and TiO2 doping of amorphous Ta2O5 coatings causes significant changes to the levels of mechanical loss measured and is thought to result from changes in the atomic structure. This work aims to find ways to reduce the levels of mechanical loss in the coatings by understanding the atomic structure properties that are responsible for it, and thus helping to increase the LIGO detector sensitivity. Using a combination of Reduced Density Functions (RDFs) from electron diffraction and Fluctuation Electron Microscopy (FEM), we probe the medium range order (in the 2-3 nm range) of these amorphous coatings

INITIAL IMAGES FROM A 24-WIRE LIQUID XENON Y -CAMERA.

A prototype liquid xenon {gamma}-camera has been constructed and preliminary results obtained. The sensitive volume is 7 c x 7 cm in area and 1.5 cm thick. Orthogonal coordinates for each interacting {gamma}-ray are provided by 24 anode wires 5 {micro} in diameter spaced 2.8 mm apart and 24 cathode strips