A modified dual-population approach for solving multi-objective problems

Maintaining the balance between convergence and diversity plays a vital role in multi-objective evolutionary algorithms (MOEAs). However, most MOEAs cannot reach a satisfying balance, especially when solving problems having complicated pareto optimal sets. In this paper, we present a modified cooperative co-evolution approach for achieving better convergence and diversity simultaneously (namely DPP2). In DPP2, while populations are trying to achieve both criteria, the priority being set for these criteria will be different. One population focuses on achieving better convergence (by using pareto-based ranking scheme), while the other is for ensuring the population diversity (by using the decomposition-based method). After that, we use a cooperation mechanism to integrate the two populations and create a new combined population with hopes of having both characteristics (i.e. converged and diverse). Performance of DPP2 is examined on the well-known benchmarks of multiobjective optimization problems (MOPs) using the hypervolume (HV), the generational distance (GD), the inverted generational distance (IGD) metrics. In comparison with the original version DPP algorithm, experimental results indicated that DPP2 can significantly outperform DPP on the benchmark problems with stable results

A competitive co-evolutionary approach for the multi-objective evolutionary algorithms

In multi-objective evolutionary algorithms (MOEAs), convergence and diversity are two basic issues and keeping a balance between them plays a vital role. There are several studies that have attempted to address this problem, but this is still an open challenge. It is thus the purpose of this research to develop a dual-population competitive co-evolutionary approach to improving the balance between convergence and diversity. We utilize two populations to solve separate tasks. The first population uses Pareto-based ranking scheme to achieve better convergence, and the second one tries to guarantee population diversity via the use of a decomposition-based method. Next, by operating a competitive mechanism to combine the two populations, we create a new one with a view to having both characteristics (i.e. convergence and diversity). The proposed method’s performance is measured by the renowned benchmarks of multi-objective optimization problems (MOPs) using the hypervolume (HV) and the inverted generational distance (IGD) metrics. Experimental results show that the proposed method outperforms cutting-edge coevolutionary algorithms with a robust performance

Detection and monitoring of cancers with biosensors in Vietnam

Biosensors are able to provide fast, accurate and reliable detec-tions and monitoring of cancer cells, as well as to determine the effectiveness of anticancer chemotherapy agents in cancer treatments. These have attracted a great attention of research communities, especially in the capabilities of detecting the path-ogens, viruses and cancer cells in narrow scale that the conven-tional apparatus and techniques do not have. This paper pre-sents technologies and applications of biosensors for detections of cancer cells and related diseases, with the focus on the cur-rent research and technology development about biosensors in Vietnam, a typical developing country with a very high number of patients diagnosed with cancers in recent years, but having a very low cancer survival rate. The role of biosensors in early detections of diseases, cancer screening, diagnosis and treat-ment, is more and more important; especially it is estimated that by 2020, 60-70% new cases of cancers and nearly 70% of cancer deaths will be in economically disadvantaged countries. The paper is also aimed to open channels for the potential R&D collaborations with partners in Vietnam in the areas of innovative design and development of biosensors in particular and medical technology devices in general

Barriers-enablers-ownership approach: A mixed methods analysis of a social intervention to improve surgical antibiotic prescribing in hospitals

Objectives To assess an intervention for surgical antibiotic prophylaxis (SAP) improvement within surgical teams focused on addressing barriers and fostering enablers and ownership of guideline compliance. Design The Queensland Surgical Antibiotic Prophylaxis (QSAP) study was a multicentre, mixed methods study designed to address barriers and enablers to SAP compliance and facilitate engagement in self-directed audit/feedback and assess the efficacy of the intervention in improving compliance with SAP guidelines. The implementation was assessed using a 24-month interrupted time series design coupled with a qualitative evaluation. Setting The study was undertaken at three hospitals (one regional, two metropolitan) in Australia. Participants SAP-prescribing decisions for 1757 patients undergoing general surgical procedures from three health services were included. Six bimonthly time points, pre-implementation and post implementation of the intervention, were measured. Qualitative interviews were performed with 29 clinical team members. SAP improvements varied across site and time periods. Intervention QSAP embedded ownership of quality improvement in SAP within surgical teams and used known social influences to address barriers to and enablers of optimal SAP prescribing. Results The site that reported senior surgeon engagement showed steady and consistent improvement in prescribing over 24 months (prestudy and poststudy). Multiple factors, including resource issues, influenced engagement and sites/time points where these were present had no improvement in guideline compliance. Conclusions The barriers-enablers-ownership model shows promise in its ability to facilitate prescribing improvements and could be expanded into other areas of antimicrobial stewardship. Senior ownership was a predictor of success (or failure) of the intervention across sites and time periods. The key role of senior leaders in change leadership indicates the critical need to engage other specialties in the stewardship agenda. The influence of contextual factors in limiting engagement clearly identifies issues of resource distributions/inequalities within health systems as limiting antimicrobial optimisation potential

Prevalence of Hepatitis B Virus (HBV) Infection Among Hmong Immigrants in the San Joaquin Valley

Chronic hepatitis B infection (HBV) is the major cause of primary liver cancer worldwide and Asians are disproportionately affected. The prevalence of HBV among most Asian American groups has been well documented, except in Hmong immigrants in the United States. The aim of this study was to determine the prevalence of HBV among Hmong immigrants in the San Joaquin Valley of California. A convenient sample of 534 Hmong age ≥18 years was recruited at various locations throughout Fresno County. Blood samples from study participants were collected and tested for hepatitis B surface antigen (HBsAg) by enzyme-immunoassay. Two hundred and eighty-nine females and 245 males of Hmong descent (mean age, 43.93) were screened. Eighty-nine (41 males and 48 females) were positive for HBsAg, which accounts for a prevalence of 16.7% (95% C.I. 13.5–19.9). The majorities of HBsAg positive patients were ≥40 years (64.2%), married (66.7%), born in Laos (87.3%), and had lived in the United States ≥20 years (62.5%). Only 37.5% of the participants reported having a primary care physician. Our study revealed that approximately one out of every six Hmong immigrants screened was infected with HBV. Based on our findings, more than one-third of these infected patients have no primary care physician to provide further treatment, surveillance for liver cancer, or vaccination of their families. This supports the Institute of Medicine’s recent recommendations to the Center for Disease Control to engage in a national Hepatitis B surveillance system

Reproductive tract infections in women seeking abortion in Vietnam

<p>Abstract</p> <p>Background</p> <p>Women requesting abortion are at increased risk of developing RTI complications. However, RTI control in many resource-poor countries including Vietnam have been faced with logistical and methodological problems due to lack of standardized definitions of RTIs, lack of well-validated diagnostic criteria, lack of accurate laboratory tests, and lack of diagnostic equipment and skills. This article investigates the prevalence of RTIs among Vietnamese abortion-seeking women, to evaluate the available diagnostic techniques, and to assess antibiotic resistance among aetiological agents of RTI.</p> <p>Method</p> <p>The study was conducted in Phu-San hospital (PSH) from December 2003 through April 2004 among 748 abortion clients. A structured questionnaire was used to collect data on socio-economic and reproductive characteristics. Specimens were collected for laboratory analyses of chlamydia, gonorrhoea, trichomoniasis, vaginal candidiasis (VC), bacterial vaginosis (BV) and syphilis. To assess the validity of the obtained results, the study was repeated among 100 women and the duplicate samples were analysed at PSH and Copenhagen University Hospital (CUH).</p> <p>Results</p> <p>In all 54% of the women were diagnosed as having an RTI, including 3.3% with sexually transmitted infections. Endogenous infections were most prevalent (VC 34% and BV 12%) followed by chlamydia (1.3%) and trichomoniasis (0.7%). The sensitivity of culture for VC and BV was 30% and 88%, respectively, when tests in PSH were measured against tests in CUH. Antibiotic resistance was common among bacterial isolates.</p> <p>Conclusion</p> <p>RTIs are common among women seeking abortion. The presence of RTIs is associated with an increased risk of developing iatrogenic infections, routine administration of prophylactic antibiotic to all women undergoing abortion should be considered. However, the choice of routine prophylactic antibiotics should be based on relevant surveillance data of antibiotic resistance. Moreover, since the accuracy of diagnosis is doubtful and to address the problem of under-diagnosed and treated RTIs new investment in diagnostic facilities with simple performed microscopy or improved rapid tests should also be taken into consideration.</p

Klebsiella pneumoniae Multiresistance Plasmid pMET1: Similarity with the Yersinia pestis Plasmid pCRY and Integrative Conjugative Elements

Dissemination of antimicrobial resistance genes has become an important public health and biodefense threat. Plasmids are important contributors to the rapid acquisition of antibiotic resistance by pathogenic bacteria.The nucleotide sequence of the Klebsiella pneumoniae multiresistance plasmid pMET1 comprises 41,723 bp and includes Tn1331.2, a transposon that carries the bla(TEM-1) gene and a perfect duplication of a 3-kbp region including the aac(6')-Ib, aadA1, and bla(OXA-9) genes. The replication region of pMET1 has been identified. Replication is independent of DNA polymerase I, and the replication region is highly related to that of the cryptic Yersinia pestis 91001 plasmid pCRY. The potential partition region has the general organization known as the parFG locus. The self-transmissible pMET1 plasmid includes a type IV secretion system consisting of proteins that make up the mating pair formation complex (Mpf) and the DNA transfer (Dtr) system. The Mpf is highly related to those in the plasmid pCRY, the mobilizable high-pathogenicity island from E. coli ECOR31 (HPI(ECOR31)), which has been proposed to be an integrative conjugative element (ICE) progenitor of high-pathogenicity islands in other Enterobacteriaceae including Yersinia species, and ICE(Kp1), an ICE found in a K. pneumoniae strain causing primary liver abscess. The Dtr MobB and MobC proteins are highly related to those of pCRY, but the endonuclease is related to that of plasmid pK245 and has no significant homology with the protein of similar function in pCRY. The region upstream of mobB includes the putative oriT and shares 90% identity with the same region in the HPI(ECOR31).The comparative analyses of pMET1 with pCRY, HPI(ECOR31), and ICE(Kp1 )show a very active rate of genetic exchanges between Enterobacteriaceae including Yersinia species, which represents a high public health and biodefense threat due to transfer of multiple resistance genes to pathogenic Yersinia strains