A voxel based morphometry study investigating brain structural changes in first episode psychosis.

Schizophrenia (SCZ) and bipolar disorder (BP) are associated with neuropathological brain changes, which are believed to disrupt connectivity between brain processes and may have common properties. Patients at first psychotic episode are unique, as one can assess brain alterations at illness inception, when many confounders are reduced or absent. SCZ (N=25) and BP (N=24) patients were recruited in a regional first episode psychosis MRI study. VBM methods were used to study gray matter (GM) and white matter (WM) differences between patient groups and case by case matched controls. For both groups, deficits identified are more discrete than those typically reported in later stages of illness. SCZ patients showed some evidence of GM loss in cortical areas but most notable were in limbic structures such as hippocampus, thalamus and striatum and cerebellum. Consistent with disturbed neural connectivity WM alterations were also observed in limbic structures, the corpus callosum and many subgyral and sublobar regions in the parietal, temporal and frontal lobes. BP patients displayed less evidence of volume changes overall, compared to normal healthy participants, but those changes observed were primarily in WM areas which overlapped with regions identified in SCZ, including thalamus and cerebellum and subgyral and sublobar sites. At first episode of psychosis there is evidence of a neuroanatomical overlap between SCZ and BP with respect to brain structural changes, consistent with disturbed neural connectivity. There are also important differences however in that SCZ displays more extensive structural alteration.

Structural changes in the hippocampus and amygdala at first episode of psychosis

<p>Hippocampus and amygdala changes have been implicated in the pathophysiology and symptomatology of both schizophrenia (SCZ) and bipolar disorder (BD). However relationships between illness course, neuropathological changes and variations in symptomatology remain unclear. This investigation examined the associations between hippocampus and amygdala volumes and symptom dimensions in schizophrenia and bipolar disorder patients after their first episode of psychosis. Symptom severity was associated with decreases in hippocampus/amygdala complex volume across groups. In keeping with previous work bilateral hippocampus and amygdala volume reductions were also identified in the SCZ patients while in BD patients only evidence of amygdala inflation reached significance. The study concludes that there appear to be important relationships between volume changes in the hippocampus and amygdala and dimensions and severity of symptomatology in psychosis. Structural alterations are apparent in both SCZ and BD after first episode of psychosis but present differently in each illness and are more severe in SCZ.</p>

Chemical and mechanical stability of sodium sulfate activated slag after exposure to elevated temperature

<p>The chemical and mechanical stability of slag activated with two different concentrations of sodium sulfate (Na<sub style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2</sub>SO<sub style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">4</sub>) after exposure to elevated temperatures ranging from 200 to 800 °C with an increment of 200 °C has been examined. Compressive strengths and pH of the hardened pastes before and after the exposure were determined. The various decomposition phases formed were identified using X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. The results indicated that Na<sub style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2</sub>SO<sub style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">4</sub> activated slag has a better resistance to the degradation caused by exposure to elevated temperature up to 600 °C than Portland cement system as its relative strengths are superior. The finer slag and higher Na<sub style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">2</sub>SO<sub style="border: 0px; font-size: 0.75em; margin: 0px; padding: 0px; line-height: 0; color: rgb(46, 46, 46); font-family: 'Arial Unicode MS', 'Arial Unicode', Arial, 'URW Gothic L', Helvetica, Tahoma, sans-serif; text-align: justify; word-spacing: -1px; background-color: rgb(255, 255, 255);">4 </sub>concentration gave better temperature resistance. Whilst the pH of the hardened pastes decreased with an increase in temperature, it still maintained a sufficiently high pH for the protection of reinforcing bar against corrosion.</p>

Parallel Peptidome and Transcriptome Analyses of Amphibian Skin Secretions Using Archived Frozen Acid-Solvated Samples

Amphibian skin secretions are unique sources of bioactive peptides and their donor species are currently rapidly disappearing from the biosphere. Here, we report that both peptides and polyadenylated mRNAs from skin granular glands remain amenable to study in samples of stimulated skin secretions following their storage in 0.1 % aqueous trifluoroacetic acid at -20 °C for many years. Frozen acidified solutions of toad (Bombina variegata) skin secretions, stored for 12 years, were thawed and samples removed for direct reverse phase HPLC fractionation. Additional samples were removed, snap frozen and lyophilised for construction of cDNA libraries following polyadenylated mRNA capture using magnetic oligo-dT beads and reverse transcription. Using the bombesin and bradykinin peptides found in bombinid toad skin as models, individual variant peptides of each type were located in reverse phase HPLC fractions and their corresponding biosynthetic precursor-encoding mRNA transcripts were cloned from the cDNA library using a RACE PCR strategy. This study illustrates unequivocally that both amphibian skin secretion peptides and their biosynthetic precursor-encoding polyadenylated mRNAs are stable in frozen acid-solvated skin secretion samples for considerable periods of time-a finding that may have fundamental implications in the study of archived materials but also in the wider field of molecular biology.

Fibre-optic strain sensor system with temperature compensation for arch bridge condition monitoring

This paper presents an innovative sensor system, created specifically for new civil engineering structural monitoring applications, allowing specially packaged fiber grating-based sensors to be used in harsh, in-the-field measurement conditions for accurate strain measurement with full temperature compensation. The sensor consists of two fiber Bragg gratings that are protected within a polypropylene package, with one of the fiber gratings isolated from the influence of strain and thus responding only to temperature variations, while the other is sensitive to both strain and temperature. To achieve this, the temperature-monitoring fiber grating is slightly bent and enclosed in a metal envelope to isolate it effectively from the strain. Through an appropriate calibration process, both the strain and temperature coefficients of each individual grating component when incorporated in the sensor system can be thus obtained. By using these calibrated coefficients in the operation of the sensor, both strain and temperature can be accurately determined. The specific application for which these sensors have been designed is seen when installed on an innovative small-scale flexi-arch bridge where they are used for real-time strain measurements during the critical installation stage (lifting) and loading. These sensors have demonstrated enhanced resilience when embedded in or surface-mounted on such concrete structures, providing accurate and consistent strain measurements not only during installation but subsequently during use. This offers an inexpensive and highly effective monitoring system tailored for the new, rapid method of the installation of small-scale bridges for a variety of civil engineering applications.