Shear Capacity of Reinforced Concrete T-Beams Retrofit with Externally Bonded CFRP Fabric: A New Perspective

Unanchored U-wrapped externally bonded carbon-fiber-reinforced polymer (CFRP) fabrics are widely used to increase the design shear strength of existing reinforced concrete slab-on-beam structures, but current design models do not accurately predict the degree of enhancement. Experimental investigations further indicate that some T-beams retrofit with externally bonded CFRP fabric fail at lower shear loads than nominally identical nonretrofit reference counterparts, suggesting a negative experimental CFRP contribution. This work finds a new application for the upper-bound theorem of plasticity in analyzing the problem of U-wrapped externally bonded CFRP-retrofit beam behavior. The study provides insight into the poor historical prediction of the CFRP contribution, and demonstrates the limitations of a widely used experimental approach to determining this contribution. The analysis suggests a new way of thinking about the behavior of slab-on-beam structures retrofit with unanchored U-wrapped externally bonded CFRP. The upper-bound plastic analysis provides better predictions of retrofit shear capacity than some widely used design models, indicating that this approach can lead to better design of retrofit interventions in future. This work proposes a new design limit on enhancement that can reduce the likelihood of unsafe design in practice

Superconducting and normal-state properties of the noncentrosymmetric superconductor Re3Ta

The noncentrosymmetric superconductor, Re3Ta, has been characterized in detail with a combination of magnetization, heat capacity, and electrical resistivity measurements, as well as a microscopic investigation of the internal magnetic fields using muon spin spectroscopy (μSR). In low applied fields, we observe 100% flux expulsion at a temperature of Tc = 4.68 K, which is concomitant with a sudden decrease of the electrical resistivity to zero and a sharp discontinuity in the heat capacity, confirming bulk superconductivity in this material. We find that Re3Ta is a poor metal, with superconductivity occurring in the dirty limit, and in which the disorder in the structure dominates the physical properties. Zero-field μSR shows that the superconducting state preserves time-reversal symmetry, and transverse-field measurements of the superfluid density are well described by an isotropic s-wave model. A careful analysis of the internal field distribution reveals a high level of disorder in the vortex lattice. Furthermore, we have combined the experimental data and calculated the effective mass, carrier density, and electronic mean-free path in this material, and ultimately show that Re3Ta lies close to the unconventional region of the Uemura plot

A Preliminary Study of Peer-to-Peer Human-Robot Interaction

The Peer-to-Peer Human-Robot Interaction (P2P-HRI) project is developing techniques to improve task coordination and collaboration between human and robot partners. Our work is motivated by the need to develop effective human-robot teams for space mission operations. A central element of our approach is creating dialogue and interaction tools that enable humans and robots to flexibly support one another. In order to understand how this approach can influence task performance, we recently conducted a series of tests simulating a lunar construction task with a human-robot team. In this paper, we describe the tests performed, discuss our initial results, and analyze the effect of intervention on task performance

Assessing the Accuracy of Adherence and Sexual Behaviour Data in the MDP301 Vaginal Microbicides Trial Using a Mixed Methods and Triangulation Model

Background: Accurate data on adherence and sexual behaviour are crucial in microbicide (and other HIV-related) research. In the absence of a “gold standard” the collection of such data relies largely on participant self-reporting. The Microbicides Development Programme has developed a mixed method/triangulation model for generating more accurate data on adherence and sexual behaviour. Methodology/Principal Findings: Data were collected from a random subsample of 725 women using structured case record form (CRF) interviews, coital diaries (CD) and in-depth interviews (IDI). Returned used and unused gel applicators were counted and additional data collected through focus group discussions and ethnography. The model is described in detail in a companion paper [1]. When CRF, CD and IDI are compared there is some inconsistency with regard to reporting of sexual behaviour, gel or condom use in more than half. Inaccuracies are least prevalent in the IDI and most prevalent in the CRF, where participants tend to under-report frequency of sex and gel and condom use. Women reported more sex, gel and condom use than their partners. IDI data on adherence match the applicator-return data more closely than the CRF. The main reasons for inaccuracies are participants forgetting, interviewer error, desirability bias, problems with the definition and delineation of key concepts (e.g. “sex act”). Most inaccuracies were unintentional and could be rectified during data collection. Conclusions/Significance: The CRF – the main source of self-report data on behaviour and adherence in many studies – was the least accurate with regard to measuring sexual behaviour, gel and condom use. This has important implications for the use of structured questionnaires for the collection of data on sexual behaviour and adherence. Integrating in-depth interviews and triangulation into clinical trials could increase the richness and accuracy of behavioural and adherence data

Bostonia: The Boston University Alumni Magazine. Volume 10

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

New functional families (FunFams) in CATH to improve the mapping of conserved functional sites to 3D structures.

CATH version 3.5 (Class, Architecture, Topology, Homology, available at http://www.cathdb.info/) contains 173 536 domains, 2626 homologous superfamilies and 1313 fold groups. When focusing on structural genomics (SG) structures, we observe that the number of new folds for CATH v3.5 is slightly less than for previous releases, and this observation suggests that we may now know the majority of folds that are easily accessible to structure determination. We have improved the accuracy of our functional family (FunFams) sub-classification method and the CATH sequence domain search facility has been extended to provide FunFam annotations for each domain. The CATH website has been redesigned. We have improved the display of functional data and of conserved sequence features associated with FunFams within each CATH superfamily

Continuing versus stopping prestroke antihypertensive therapy in acute intracerebral hemorrhage: a subgroup analysis of the efficacy of nitric oxide in stroke trial

Background and purpose: More than 50% of patients with acute intracerebral haemorrhage (ICH) are taking antihypertensive drugs before ictus. Although antihypertensive therapy should be given long term for secondary prevention, whether to continue or stop such treatment during the acute phase of ICH remains unclear, a question that was addressed in the Efficacy of Nitric Oxide in Stroke (ENOS) trial. Methods: ENOS was an international multicenter, prospective, randomized, blinded endpoint trial. Among 629 patients with ICH and systolic blood pressure between 140 and 220 mmHg, 246 patients who were taking antihypertensive drugs were assigned to continue (n = 119) or to stop (n = 127) taking drugs temporarily for 7 days. The primary outcome was the modified Rankin Score at 90 days. Secondary outcomes included death, length of stay in hospital, discharge destination, activities of daily living, mood, cognition, and quality of life. Results: Blood pressure level (baseline 171/92 mmHg) fell in both groups but was significantly lower at 7 days in those patients assigned to continue antihypertensive drugs (difference 9.4/3.5 mmHg, P < .01). At 90 days, the primary outcome did not differ between the groups; the adjusted common odds ratio (OR) for worse outcome with continue versus stop drugs was .92 (95% confidence interval, .45- 1.89; P = .83). There was no difference between the treatment groups for any secondary outcome measure, or rates of death or serious adverse events. Conclusions: Among patients with acute ICH, immediate continuation of antihypertensive drugs during the first week did not reduce death or major disability in comparison to stopping treatment temporarily