STR-988: POST-FIRE RESIDUAL STRENGTH OF GLASS FIBRE REINFORCED POLYMER (GFRP) BARS

Lack of reliable and adequate information on material characteristics of glass fibre reinforced polymer (GFRP) at elevated temperatures lowers the accuracy of analytical and design models developed to predict the behaviour of GFRP reinforced concrete members. There is an essential need to assess the remaining strength of bridge and building components after exposure to fire to determine if repair or replacement is required. This paper presents experimental results of a series of tensile tests on GFRP reinforcing bars after exposure to elevated temperatures. GFRP specimens with nominal diameter of 16 mm were exposed to different temperatures in an electric furnace. During the heat exposure, the samples were loaded with 25 % of their ultimate tensile strength to simulate the sustained load that a reinforcing bar in a concrete member may carry in a fire incident. After the samples cooled to room temperature, they were loaded to failure. The same type of GFRP bars had been tested earlier by the authors under simultaneous effects of heat and load. At high temperature, the bars had considerable strength loss. However, the results presented in this paper show notable tensile strength recovery when the specimens were cooled before loading to failure. This information is essential for studying the post-fire evaluation of GFRP reinforced concrete members exposed to fires

Population level trends in the distribution of body mass index in England, 1992-2013

Background: Changes over time of mean body weight or prevalence of overweight and obesity have been well documented. Less consideration has been given to describing the distribution to these changes particularly by socioeconomic status and sex. Methods: We use data from the Health Survey for England for the years 1992 to 2013 to calculate the median, 5th and 95th percentiles, and standard deviation of BMI (body mass index). We tested differences using ANOVA and quantile regression. Analyses were stratified by sex and level of education. Results: There have been increases in the standard deviation of BMI values over the period. Whilst median BMI has increased, there has been a larger increase of the 95th percentile. These trends were consistent by sex and level of education, although significant differences were observed in values. Conclusion: Our results demonstrate that changes in median BMI over time do not reflect changes in the distribution of BMI. Failing to understand the distribution of body weight in the population will hamper our projections of future patterns, as well as our ability to design effective public health strategies

STR-924: EFFECT OF LOW TEMPERATURE ON THE SHEAR-FATIGUE PERFORMANCE OF REINFORCED CONCRETE BEAMS

This paper investigates the fatigue behaviour of a reinforced concrete beam (without shear reinforcement) at low temperature (-20°C) compared to a similar beam tested near room temperature (+16°C). Two large-scale steel reinforced beams (200 mm x 400 mm x 4200 mm) were fabricated and tested. The beams had temperature differentials over their depth to simulate solar radiation and in-service temperature of the bridges. The beams were cyclically loaded to failure with a stress range representing the ratio of live to dead loads found in most bridges. This study showed that low temperature increased the fatigue life of the reinforced concrete beam by 51%, and changed the mode of failure of the beam from shear fatigue failure at room temperature to flexural fatigue failure at low temperature. It was observed that the low and room temperature beams maintained 65% and 31% of their original flexural rigidity indicating that low temperature mitigated the stiffness degradation of the reinforced concrete caused by fatigue loading. The strains in the tensile reinforcement of the low temperature beam were much lower than the room temperature beam which could be due to the higher strength of concrete and reduction in concrete softening at low temperature which resulted in lower stresses in the tensile reinforcement. The findings of this study show that the contribution of concrete under either static or cyclic load becomes much higher at low temperature

Magnetic-crystallographic phase diagram of superconducting parent compound Fe1+x_{1+x}Te

hrough neutron diffraction experiments, including spin-polarized measurements, we find a collinear incommensurate spin-density wave with propagation vector $\mathbf k =$ ($0.4481(4) \, \,0 \, \, \frac1 2$) at base temperature in the superconducting parent compound Fe$_{1+x}$Te. This critical concentration of interstitial iron corresponds to $x \approx 12$ and leads crystallographic phase separation at base temperature. The spin-density wave is short-range ordered with a correlation length of 22(3) \AA, and as the ordering temperature is approached its propagation vector decreases linearly in the H-direction and becomes long-range ordered. Upon further populating the interstitial iron site, the spin-density wave gives way to an incommensurate helical ordering with propagation vector $\mathbf k =$ ($0.3855(2) \, \,0 \, \, \frac1 2$) at base temperature. For a sample with $x \approx 9(1)$, we also find an incommensurate spin-density wave that competes with the bicollinear commensurate ordering close to the N\'eel point. The shifting of spectral weight between competing magnetic orderings observed in several samples is supporting evidence for the phase separation being electronic in nature, and hence leads to crystallographic phase separation around the critical interstitial iron concentration of 12%. With results from both powder and single crystal samples, we construct a magnetic-crystallographic phase diagram of Fe$_{1+x}$Te for $ 5% < x <17%

Assessing neural tuning for object perception in schizophrenia and bipolar disorder with multivariate pattern analysis of fMRI data.

IntroductionDeficits in visual perception are well-established in schizophrenia and are linked to abnormal activity in the lateral occipital complex (LOC). Related deficits may exist in bipolar disorder. LOC contains neurons tuned to object features. It is unknown whether neural tuning in LOC or other visual areas is abnormal in patients, contributing to abnormal perception during visual tasks. This study used multivariate pattern analysis (MVPA) to investigate perceptual tuning for objects in schizophrenia and bipolar disorder.MethodsFifty schizophrenia participants, 51 bipolar disorder participants, and 47 matched healthy controls completed five functional magnetic resonance imaging (fMRI) runs of a perceptual task in which they viewed pictures of four different objects and an outdoor scene. We performed classification analyses designed to assess the distinctiveness of activity corresponding to perception of each stimulus in LOC (a functionally localized region of interest). We also performed similar classification analyses throughout the brain using a searchlight technique. We compared classification accuracy and patterns of classification errors across groups.ResultsStimulus classification accuracy was significantly above chance in all groups in LOC and throughout visual cortex. Classification errors were mostly within-category confusions (e.g., misclassifying one chair as another chair). There were no group differences in classification accuracy or patterns of confusion.ConclusionsThe results show for the first time MVPA can be used successfully to classify individual perceptual stimuli in schizophrenia and bipolar disorder. However, the results do not provide evidence of abnormal neural tuning in schizophrenia and bipolar disorder

Trimerisation of carbon suboxide at a di-titanium centre to form a pyrone ring system

The reaction of the syn-bimetallic bis(pentalene)dititanium complex Ti2(μ:η5,η5-Pn†)2 (Pn† = C8H4(1,4-SiiPr3)2) 1 with carbon suboxide (O[double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash]C[double bond, length as m-dash]O, C3O2) results in trimerisation of the latter and formation of the structurally characterised complex [{Ti2(μ:η5,η5-Pn†)2}{μ-C9O6}]. The trimeric bridging C9O6 unit in the latter contains a 4-pyrone core, a key feature of both the hexamer and octamer of carbon suboxide which are formed in the body from trace amounts of C3O2 and are, for example, potent inhibitors of Na+/K+-ATP-ase. The mechanism of this reaction has been studied in detail by DFT computational studies, which also suggest that the reaction proceeds via the initial formation of a mono-adduct of 1 with C3O2. Indeed, the carefully controlled reaction of 1 with C3O2 affords [Ti2(μ:η5,η5-Pn†)2 (η2-C3O2)], as the first structurally authenticated complex of carbon suboxide

Coyotes Go “Bridge and Tunnel”: A Narrow Opportunity to Study the Socio-ecological Impacts of Coyote Range Expansion on Long Island, NY Pre- and Post-Arrival

Currently, Long Island, NY is without a breeding population of northeastern coyote (Canis latras var.), yet recent evidence of dispersing individuals on the island, coupled with the “dogged” momentum of coyote range expansion across North America, suggests a Long Island coyote population is close at hand. We highlighted the fleeting opportunity to takes advantage of this natural experiment by developing a multidisciplinary research framework to investigate the ecological and social impacts of the coyote, pre- and post- range expansion. We reviewed coyote spatial ecology, community ecology, and human dimensions research and identified three components of future investigation: predicting future occupancy, monitoring colonization, testing hypotheses of trophic cascades by leveraging and expanding existing ecological data, and exploring attitudes towards coyotes to better understand and mitigate human-wildlife conflicts. Each proposed component will integrate for a comprehensive investigation to advance theory and applied management of northeastern coyotes

Data-Driven Audiogram Classification for Mobile Audiometry

Recent mobile and automated audiometry technologies have allowed for the democratization of hearing healthcare and enables non-experts to deliver hearing tests. The problem remains that a large number of such users are not trained to interpret audiograms. In this work, we outline the development of a data-driven audiogram classification system designed specifically for the purpose of concisely describing audiograms. More specifically, we present how a training dataset was assembled and the development of the classification system leveraging supervised learning techniques. We show that three practicing audiologists had high intra- and inter-rater agreement over audiogram classification tasks pertaining to audiogram configuration, symmetry and severity. The system proposed here achieves a performance comparable to the state of the art, but is signific

Neural substrates of visual masking by object substitution in schizophrenia

Despite a well-known behavioral finding of visual backward masking impairment in schizophrenia, its underlying neural mechanism remains obscure. This study examined neural correlates of a distinct type of visual backward masking, object substitution masking (OSM), in schizophrenia. Twenty schizophrenia patients and 26 healthy controls completed a 4-Dot OSM task and three functional localizer tasks for the lateral occipital (LO), human motion-sensitive (hMT+), and retinotopic areas in the scanner. In 4-dot masking, subjects detected a target that was followed by a mask consisting of 4 dots that surrounded a target. Stimulus-onset asynchrony (SOA) between target and mask was varied to examine the modulation of masking: (1) within three visual processing areas regions of interest (ROI) (i.e., ROI analysis) and (2) in brain regions outside the three visual processing areas (i.e., whole brain analysis). In the ROI analyses, LO and retinotopic areas showed increased peak amplitude when SOA become longer in both patients and controls. There was also an effect of ROI in that both groups showed higher activation in LO and hMT+ compared with the retinotopic areas. The whole brain analyses revealed a significantly activated area for longer SOAs vs. a short SOA in the occipital cortex in controls only, but the group contrast was not significant. Overall, this study did not find strong evidence for neural abnormalities of OSM in schizophrenia, suggesting that neural substrates of OSM in schizophrenia are not as compromised as those involved in the more common masking methods that rely on disruption of object formation

Generalized Analysis of Weakly-Interacting Massive Particle Searches

We perform a generalized analysis of data from WIMP search experiments for point-like WIMPs of arbitrary spin and general Lorenz-invariant WIMP-nucleus interaction. We show that in the non-relativistic limit only spin-independent (SI) and spin-dependent (SD) WIMP-nucleon interactions survive, which can be parameterized by only five independent parameters. We explore this five-dimensional parameter space to determine whether the annual modulation observed in the DAMA experiment can be consistent with all other experiments. The pure SI interaction is ruled out except for very small region of parameter space with the WIMP mass close to 50 GeV and the ratio of the WIMP-neutron to WIMP-proton SI couplings $-0.77\le f_n/f_p\le -0.75$. For the predominantly SD interaction, we find an upper limit to the WIMP mass of about 18 GeV, which can only be weakened if the constraint stemming from null searches for energetic neutrinos from WIMP annihilation the Sun is evaded. None of the regions of the parameter space that can reconcile all WIMP search results can be easily accommodated in the minimal supersymmetric extension of the standard model.Comment: 27 pages, 3 figure