Simple, reproducible methods for thermal shock testing of brittle materials

Technique requires radio frequency induction power source, induction furnace and good vacuum system to induce brittle material thermal shock testing

Repeatable method of thermal stress fracture test of brittle materials

Method heats specimens slowly and with sufficient control so that the critical temperature gradient in the specimens cannot occur before temperature equilibrium is reached

Fusion barrier distributions in systems with finite excitation energy

Eigen-channel approach to heavy-ion fusion reactions is exact only when the excitation energy of the intrinsic motion is zero. In order to take into account effects of finite excitation energy, we introduce an energy dependence to weight factors in the eigen-channel approximation. Using two channel problem, we show that the weight factors are slowly changing functions of incident energy. This suggests that the concept of the fusion barrier distribution still holds to a good approximation even when the excitation energy of the intrinsic motion is finite. A transition to the adiabatic tunneling, where the coupling leads to a static potential renormalization, is also discussed.Comment: 9 pages, 4 figures, Submitted to Physical Review

Evidence of Double Phonon Excitations in ^{16}O + ^{208}Pb Reaction

The fusion cross-sections for ^{16}O + ^{208}Pb, measured to high precision, enable the extraction of the distribution of fusion barriers. This shows a structure markedly different from the single-barrier which might be expected for fusion of two doubly-closed shell nuclei. The results of exact coupled channel calculations performed to understand the observations are presented. These calculations indicate that coupling to a double octupole phonon excited state in ^{208}Pb is necessary to explain the experimental barrier distributions.Comment: 6 pages, 2 figures, To be published in the Proceedings of the FUSION 97 Conference, South Durras, Australia, March 1997 (J. Phys. G

Contributions of Tropodithietic Acid and Biofilm Formation to the Probiotic Activity of Phaeobacter Inhibens

Background: The probiotic bacterium Phaeobacter inhibens strain S4Sm, isolated from the inner shell surface of a healthy oyster, secretes the antibiotic tropodithietic acid (TDA), is an excellent biofilm former, and increases oyster larvae survival when challenged with bacterial pathogens. In this study, we investigated the specific roles of TDA secretion and biofilm formation in the probiotic activity of S4Sm. Results: Mutations in clpX (ATP-dependent ATPase) and exoP (an exopolysaccharide biosynthesis gene) were created by insertional mutagenesis using homologous recombination. Mutation of clpX resulted in the loss of TDA production, no decline in biofilm formation, and loss of the ability to inhibit the growth of Vibrio tubiashii and Vibrio anguillarum in co-colonization experiments. Mutation of exoP resulted in a ~60 % decline in biofilm formation, no decline in TDA production, and delayed inhibitory activity towards Vibrio pathogens in co-colonization experiments. Both clpX and exoP mutants exhibited reduced ability to protect oyster larvae from death when challenged by Vibrio tubiashii. Complementation of the clpX and exoP mutations restored the wild type phenotype. We also found that pre-colonization of surfaces by S4Sm was critical for this bacterium to inhibit pathogen colonization and growth. Conclusions: Our observations demonstrate that probiotic activity by P. inhibens S4Sm involves contributions from both biofilm formation and the production of the antibiotic TDA. Further, probiotic activity also requires colonization of surfaces by S4Sm prior to the introduction of the pathogen. Keywords: Phaeobacter inhibens, Tropodithietic acid, Biofilm formation, Probiotic, Marine pathogens, Vibrio tubiashii, Vibrio anguillarum, Oyster disease, ClpX, Exo

How do hospitals respond to feedback about blood transfusion practice? A multiple case study investigation

National clinical audits play key roles in improving care and driving system-wide change. However, effects of audit and feedback depend upon both reach (e.g. relevant staff receiving the feedback) and response (e.g. staff regulating their behaviour accordingly). This study aimed to investigate which hospital staff initially receive feedback and formulate a response, how feedback is disseminated within hospitals, and how responses are enacted (including barriers and enablers to enactment). Using a multiple case study approach, we purposively sampled four UK hospitals for variation in infrastructure and resources. We conducted semi-structured interviews with staff from transfusion-related roles and observed Hospital Transfusion Committee meetings. Interviews and analysis were based on the Theoretical Domains Framework of behaviour change. We coded interview transcripts into theoretical domains, then inductively identified themes within each domain to identify barriers and enablers. We also analysed data to identify which staff currently receive feedback and how dissemination is managed within the hospital. Members of the hospital’s transfusion team initially received feedback in all cases, and were primarily responsible for disseminating and responding, facilitated through the Hospital Transfusion Committee. At each hospital, key individuals involved in prescribing transfusions reported never having received feedback from a national audit. Whether audits were discussed and actions explicitly agreed in Committee meetings varied between hospitals. Key enablers of action across all cases included clear lines of responsibility and strategies to remind staff about recommendations. Barriers included difficulties disseminating to relevant staff and needing to amend feedback to make it appropriate for local use. Appropriate responses by hospital staff to feedback about blood transfusion practice depend upon supportive infrastructures and role clarity. Hospitals could benefit from support to disseminate feedback systematically, particularly to frontline staff involved in the behaviours being audited, and practical tools to support strategic decision-making (e.g. action-planning around local response to feedback)

Grid Loss: Detecting Occluded Faces

Detection of partially occluded objects is a challenging computer vision problem. Standard Convolutional Neural Network (CNN) detectors fail if parts of the detection window are occluded, since not every sub-part of the window is discriminative on its own. To address this issue, we propose a novel loss layer for CNNs, named grid loss, which minimizes the error rate on sub-blocks of a convolution layer independently rather than over the whole feature map. This results in parts being more discriminative on their own, enabling the detector to recover if the detection window is partially occluded. By mapping our loss layer back to a regular fully connected layer, no additional computational cost is incurred at runtime compared to standard CNNs. We demonstrate our method for face detection on several public face detection benchmarks and show that our method outperforms regular CNNs, is suitable for realtime applications and achieves state-of-the-art performance.Comment: accepted to ECCV 201

Identifying SLI in deaf children acquiring British Sign Language: Implications for theory and practice

This paper presents the first ever group study of specific language impairment (SLI) in users of sign language. A group of 50 children were referred to the study by teachers and speech and language therapists. Individuals who fitted pre-determined criteria for SLI were then systematically assessed. Here, we describe in detail the performance of 13 signing deaf children aged 5–14 years on normed tests of British Sign Language (BSL) sentence comprehension, repetition of nonsense signs, expressive grammar and narrative skills, alongside tests of non-verbal intelligence and fine motor control. Results show these children to have a significant language delay compared to their peers matched for age and language experience. This impaired development cannot be explained by poor exposure to BSL, or by lower general cognitive, social, or motor abilities. As is the case for SLI in spoken languages, we find heterogeneity within the group in terms of which aspects of language are affected and the severity of the impairment. We discuss the implications of the existence of language impairments in a sign language for theories of SLI and clinical practice

RNA-Containing Cytoplasmic Inclusion Bodies in Ciliated Bronchial Epithelium Months to Years after Acute Kawasaki Disease

Kawasaki Disease (KD) is the most common cause of acquired heart disease in children in developed nations. The KD etiologic agent is unknown but likely to be a ubiquitous microbe that usually causes asymptomatic childhood infection, resulting in KD only in genetically susceptible individuals. KD synthetic antibodies made from prevalent IgA gene sequences in KD arterial tissue detect intracytoplasmic inclusion bodies (ICI) resembling viral ICI in acute KD but not control infant ciliated bronchial epithelium. The prevalence of ICI in late-stage KD fatalities and in older individuals with non-KD illness should be low, unless persistent infection is common.Lung tissue from late-stage KD fatalities and non-infant controls was examined by light microscopy for the presence of ICI. Nucleic acid stains and transmission electron microscopy (TEM) were performed on tissues that were strongly positive for ICI. ICI were present in ciliated bronchial epithelium in 6/7 (86%) late-stage KD fatalities and 7/27 (26%) controls ages 9-84 years (p = 0.01). Nucleic acid stains revealed RNA but not DNA within the ICI. ICI were also identified in lung macrophages in some KD cases. TEM of bronchial epithelium and macrophages from KD cases revealed finely granular homogeneous ICI.These findings are consistent with a previously unidentified, ubiquitous RNA virus that forms ICI and can result in persistent infection in bronchial epithelium and macrophages as the etiologic agent of KD