A probabilistic approach for quantitative identification of multiple delaminations in laminated composite beams using guided waves

Available online 16 September 2016In this study a probabilistic approach is proposed to identify multiple delaminations in laminated composite beams using guided waves. The proposed method is a model-based approach, which provides a quantitative identification of the delaminations. This study puts forward a practical damage identification method, and hence, it can identify multiple delaminations using guided wave signal measured at a single measurement point on the laminated composite beams. The proposed method first determines the number of delaminations using Bayesian model class selection method. The Bayesian statistical framework is then employed to not only identify the delamination locations, lengths and through-thickness locations, but also quantify the associated uncertainties, which provides valuable information for engineers in making decision on necessary remedial work. In addition the proposed method employs the time-domain spectral finite element method and Bayesian updating with Subset simulation to further improve the computational efficiency. The proposed probabilistic approach is verified and demonstrated using data obtained from numerical simulations, which consider both measurement noise and modeling error, and experimental data. The results show that the proposed method can accurately determine the number of delaminations, and the identified delamination locations, lengths and through-thickness locations are closed to the true values.Shuai He, Ching-Tai N

University Staff’s Perceptions of Community College Transfer Students’ Transition Experiences Within a “2+2” Pathway in an Asian Educational Context

Various countries have alternative pathway policies for 2-year community college graduates to articulate to 2-year university study, forming a “2+2” pathway. However, few studies have explored university staff members’ perceptions of this “2+2” transfer pathway and their understanding of transfer students’ (TSs) transition experiences. This descriptive qualitative study addressed this research gap. Forty-two academic and supporting staff participated in the focus group interviews. Specifically, the study explored the assets and challenges of the “2+2” pathway from the university staff perspective in Hong Kong. The articulation pathway and TSs are highly recognized for their prior learning, academic performances, and the value of the second chance. However, while the university staff were sympathetic to the challenges filling these transfer pathways, their offering of help was limited by government funding and policies restrictions. It is recommended that policies should be established at government and university levels to recognize and tackle TSs’ unique needs to alleviate their heavy workloads through better articulation between community college and university studies. Improving articulation will allow TSs time for social involvement in university life and thus enhance their mental well-being

Bridging dentistry and traditional Chinese medicine : a study on the current mutual understanding among the future practitioners

Objectives: This project aimed to promote the mutual understanding between dental and TCM students. The objectives were to describe the current teaching of dentistry in the TCM schools and that of TCM in the dental school, to describe the TCM students’ knowledge on dentistry and the dental students’ knowledge on TCM, and to produce promotional materials for enhancing the mutual understanding between dental and TCM students. Methods: Information on the current teaching of dentistry in the TCM schools and that of TCM in the dental school was collected through a search on the undergraduate programme syllabus and conducting interviews with the leaders of the schools. Questionnaire surveys were conducted among the final year students of the TCM and the dental schools to collect information on their knowledge of the counter profession. Two leaflets and a short video were produced with the aid of computer software and used in the promotional activities. Results: It was found that very little information on dentistry was covered in the undergraduate programmes of the three TCM schools, and vice versa in the dental school. A total of 39 TCM students and 55 dental students completed the questionnaire survey. Most of the students did not know the basic theories and practice of the counter profession. Less than half of the student knew what types of patient cases may be suitable for cross-referral to the other profession. Conclusions: The TCM and dental schools in Hong Kong do not have scheduled teaching on the counter profession. The TCM students have little knowledge on dentistry and how to collaborate with dental practitioners on patients presented with oral problems. Conversely, it is the same for the dental students. Lastly, informative printed and audio-visual promotional materials can be produced with limited resources and used to facilitate the mutual understanding between TCM and dental practitioners.published_or_final_versio

Association of antipsychotic use with breast cancer:a systematic review and meta-analysis of observational studies with over 2 million individuals-CORRIGENDUM

AIMS: Despite reports of an elevated risk of breast cancer associated with antipsychotic use in women, existing evidence remains inconclusive. We aimed to examine existing observational data in the literature and determine this hypothesised association. METHODS: We searched Embase, PubMed and Web of Science™ databases on 27 January 2022 for articles reporting relevant cohort or case-control studies published since inception, supplemented with hand searches of the reference lists of the included articles. Quality of studies was assessed using the Newcastle-Ottawa Scale. We generated the pooled odds ratio (OR) and pooled hazard ratio (HR) using a random-effects model to quantify the association. This study was registered with PROSPERO (CRD42022307913). RESULTS: Nine observational studies, including five cohort and four case-control studies, were eventually included for review (N = 2 031 380) and seven for meta-analysis (N = 1 557 013). All included studies were rated as high-quality (seven to nine stars). Six studies reported a significant association of antipsychotic use with breast cancer, and a stronger association was reported when a greater extent of antipsychotic use, e.g. longer duration, was operationalised as the exposure. Pooled estimates of HRs extracted from cohort studies and ORs from case-control studies were 1.39 [95% confidence interval (CI) 1.11–1.73] and 1.37 (95% CI 0.90–2.09), suggesting a moderate association of antipsychotic use with breast cancer. CONCLUSIONS: Antipsychotic use is moderately associated with breast cancer, possibly mediated by prolactin-elevating properties of certain medications. This risk should be weighed against the potential treatment effects for a balanced prescription decision

Entomologic and molecular investigation into Plasmodium vivax transmission in Singapore, 2009

<p>Abstract</p> <p>Background</p> <p>Singapore has been certified malaria free since November 1982 by the World Health Organization and despite occasional local transmission, the country has maintained the standing. In 2009, three clusters of malaria cases were reported in Singapore.</p> <p>Methods</p> <p>Epidemiological, entomological and molecular studies were carried out to investigate the three clusters, namely Mandai-Sungei Kadut, Jurong Island and Sembawang.</p> <p>Results</p> <p>A total of 29 malaria patients, with no recent travel history, were reported in the three clusters. Molecular analysis based on the <it>msp3α </it>and <it>msp1 </it>genes showed two independent local transmissions: one in Mandai-Sungei Kadut and another in Sembawang. Almost all cases within each cluster were epidemiologically linked. In Jurong Island cluster, epidemiological link remains uncertain, as almost all cases had a unique genetic profile. Only two cases shared a common profile and were found to be linked to the Mandai-Sungei Kadut cluster. Entomological investigation found <it>Anopheles sinensis </it>to be the predominant Anopheline in the two areas where local transmission of <it>P. vivax </it>was confirmed. <it>Anopheles sinensis </it>was found to be attracted to human bait and bites as early as 19:45 hrs. However, all <it>Anopheles </it>mosquitoes caught were negative for sporozoites and oocysts by dissection.</p> <p>Conclusion</p> <p>Investigation of <it>P. vivax </it>cases from the three cluster areas confirmed the occurrence of local transmission in two areas. Although <it>An. sinensis </it>was the predominant Anopheline found in areas with confirmed transmission, the vector/s responsible for the outbreaks still remains cryptic.</p

Non-adjacent dependency learning in Cantonese-speaking children with and without a history of specific language impairment

Purpose: This study investigated non-adjacent dependency learning in Cantonese-speaking children with and without a history of Specific Language Impairment (SLI) in an artificial linguistic context. Method: Sixteen Cantonese-speaking children with SLI history and 16 Cantonese-speaking children with typical language development (TLD) were tested with a non-adjacent dependency learning task using artificial languages that mimic Cantonese. Results: Children with TLD performed above chance and were able to discriminate between trained and untrained non-adjacent dependencies. However, children with SLI history performed at chance and were not able to differentiate trained versus untrained non-adjacent dependencies. Conclusions: These findings, together with previous findings with English-speaking adults and adolescents with language impairments, suggested that individuals with atypical language development, regardless of age, diagnostic status, language and culture, showed difficulties in learning non-adjacent dependencies. This study provides evidence for early impairments to statistical learning in individuals with atypical language development

Characterization of partitioning behaviors of immunoglobulin G in polymer-salt aqueous two-phase systems

The partitioning behavior of immunoglobulin G (IgG) in the aqueous two-phase system (ATPS) composed of poly(ethylene glycol) (PEG) and phosphate was studied. The parameters of ATPS exhibiting the pronounced effects on the partitioning behavior of IgG include phase composition, PEG molecular weight, and the addition of sodium chloride (NaCl). The accumulation of IgG at the interface of the ATPS increased drastically as the tie-line length (TLL) was increased. This trend was correlated with a linear relationship relating the natural logarithm of interfacial partition coefficient (ln G) to the difference of PEG concentration between the top phase and the bottom phase (Δ[PEG]), and a good fit was obtained. An attempt was made to correlate the natural logarithm of partition coefficient (ln K) to the presence of NaCl with the proposed linear relationship, ln K = α″ ln [Cl-] + β″. The proposed relationship, which serves as a better description of the underlying mechanics of the protein partitioning behavior in the polymer-salt ATPS, provides a good fit (r2 > 0.95) for the data of IgG partitioning. An optimum recovery of 99.97% was achieved in an ATPS (pH 7.5) composed of 14.0% (w/w) PEG 1450, 12.5% (w/w) phosphate and 5.0% (w/w) NaCl

Locating delaminations in laminated composite beams using nonlinear guided waves

Available online 14 November 2016This paper proposes a new method for detecting and locating delaminations in laminated composite beams using nonlinear guided wave. It is shown that when incident wave interacts at the delamination, the nonlinear effect of wave interaction with contact interfaces at the delamination generates higher harmonic guided waves due to contact acoustic nonlinearity (CAN). The proposed method employs a transducer network to detect and locate the delamination using the higher harmonic guided waves. A sequential scan is used to inspect the laminated composite beams by actuating the fundamental anti-symmetric mode (A0) of guided wave at one of the transducers while the rest of the transducers are used for measuring the impinging waves. A series of numerical case studies are performed using three-dimensional explicit finite element simulations, which consider different delamination locations, lengths and through-thickness locations. Experimental case studies are carried out to further validate and demonstrate the capability of the proposed method. The results show that the proposed method is able to accurately detect and locate the delamination in the laminated composite beams using the higher harmonic guided waves. One of the advantages of the proposed method is that it does not rely on baseline data to detect and locate the delamination, and hence, it has less influence by varying operational and environmental conditions.Reza Soleimanpour, Ching-Tai N

Prevalence of Cataract Surgery and Visual Outcomes in Indian Immigrants in Singapore: The Singapore Indian Eye Study

10.1371/journal.pone.0075584PLoS ONE810-POLN