A memetic algorithm with adaptive hill climbing strategy for dynamic optimization problems

Copyright @ Springer-Verlag 2008Dynamic optimization problems challenge traditional evolutionary algorithms seriously since they, once converged, cannot adapt quickly to environmental changes. This paper investigates the application of memetic algorithms, a class of hybrid evolutionary algorithms, for dynamic optimization problems. An adaptive hill climbing method is proposed as the local search technique in the framework of memetic algorithms, which combines the features of greedy crossover-based hill climbing and steepest mutation-based hill climbing. In order to address the convergence problem, two diversity maintaining methods, called adaptive dual mapping and triggered random immigrants, respectively, are also introduced into the proposed memetic algorithm for dynamic optimization problems. Based on a series of dynamic problems generated from several stationary benchmark problems, experiments are carried out to investigate the performance of the proposed memetic algorithm in comparison with some peer evolutionary algorithms. The experimental results show the efficiency of the proposed memetic algorithm in dynamic environments.This work was supported by the National Nature Science Foundation of China (NSFC) under Grant Nos. 70431003 and 70671020, the National Innovation Research Community Science Foundation of China under Grant No. 60521003, and the National Support Plan of China under Grant No. 2006BAH02A09 and the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/01

A Rapid Assessment of the Quality of Neonatal Healthcare in Kilimanjaro Region, Northeast Tanzania.

While child mortality is declining in Africa there has been no evidence of a comparable reduction in neonatal mortality. The quality of inpatient neonatal care is likely a contributing factor but data from resource limited settings are few. The objective of this study was to assess the quality of neonatal care in the district hospitals of the Kilimanjaro region of Tanzania. Clinical records were reviewed for ill or premature neonates admitted to 13 inpatient health facilities in the Kilimanjaro region; staffing and equipment levels were also assessed. Among the 82 neonates reviewed, key health information was missing from a substantial proportion of records: on maternal antenatal cards, blood group was recorded for 52 (63.4%) mothers, Rhesus (Rh) factor for 39 (47.6%), VDRL for 59 (71.9%) and HIV status for 77 (93.1%). From neonatal clinical records, heart rate was recorded for3 (3.7%) neonates, respiratory rate in 14, (17.1%) and temperature in 33 (40.2%). None of 13 facilities had a functioning premature unit despite calculated gestational age <36 weeks in 45.6% of evaluated neonates. Intravenous fluids and oxygen were available in 9 out of 13 of facilities, while antibiotics and essential basic equipment were available in more than two thirds. Medication dosing errors were common; under-dosage for ampicillin, gentamicin and cloxacillin was found in 44.0%, 37.9% and 50% of cases, respectively, while over-dosage was found in 20.0%, 24.2% and 19.9%, respectively. Physician or assistant physician staffing levels by the WHO indicator levels (WISN) were generally low. Key aspects of neonatal care were found to be poorly documented or incorrectly implemented in this appraisal of neonatal care in Kilimanjaro. Efforts towards quality assurance and enhanced motivation of staff may improve outcomes for this vulnerable group

Los clubes deportivos de natación de Cataluña en el actual contexto competitivo del sector de las instalaciones deportivas

Swimming clubs are non-profit entities for sports and social purposes. The general objective of the study was to know the management of swimming clubs in Catalonia, fulfilling their social and sports role in the current competitive environment of sports facilities. As specific objectives were to know their values on management indicators, as well as to know if significant differences between swimming clubs are found, taking in consideration their areas and sports offer. The study sample consists of 19 swimming clubs of Catalonia. The data collection instrument was a questionnaire adapted to the objectives of the study, administered by email to the managers of each club. The clubs obtain the necessary income to achieve their sporting and social goals thanks to the fees of their members. It was found significant differences between them according to the spaces and sports offer in different management indicators analyzed.Los clubes de natación son entidades sin ánimo de lucro con fines deportivos y sociales. El objetivo general del estudio fue conocer la gestión de los clubes de natación en Cataluña cumpliendo su función social y deportiva en el actual entorno competitivo de instalaciones deportivas. Los objetivos específicos fueron conocer sus valores en indicadores de gestión, así como saber si existen diferencias significativas entre los clubes según sus espacios y oferta deportiva. La muestra del estudio ha sido formada por 19 clubes deportivos de natación de Cataluña. El instrumento de recogida de datos fue un cuestionario adaptado a los objetivos del estudio, administrado por correo electrónico a los gerentes de cada club. Los clubes obtienen los ingresos necesarios para lograr sus fines deportivos y sociales gracias a las cuotas de sus socios. Se encontraron diferencias significativas entre ellos según los espacios y oferta deportiva en diferentes indicadores de gestión analizados

How citation boosts promote scientific paradigm shifts and Nobel Prizes

Nobel Prizes are commonly seen to be among the most prestigious achievements of our times. Based on mining several million citations, we quantitatively analyze the processes driving paradigm shifts in science. We find that groundbreaking discoveries of Nobel Prize Laureates and other famous scientists are not only acknowledged by many citations of their landmark papers. Surprisingly, they also boost the citation rates of their previous publications. Given that innovations must outcompete the rich-gets-richer effect for scientific citations, it turns out that they can make their way only through citation cascades. A quantitative analysis reveals how and why they happen. Science appears to behave like a self-organized critical system, in which citation cascades of all sizes occur, from continuous scientific progress all the way up to scientific revolutions, which change the way we see our world. Measuring the "boosting effect" of landmark papers, our analysis reveals how new ideas and new players can make their way and finally triumph in a world dominated by established paradigms. The underlying "boost factor" is also useful to discover scientific breakthroughs and talents much earlier than through classical citation analysis, which by now has become a widespread method to measure scientific excellence, influencing scientific careers and the distribution of research funds. Our findings reveal patterns of collective social behavior, which are also interesting from an attention economics perspective. Understanding the origin of scientific authority may therefore ultimately help to explain, how social influence comes about and why the value of goods depends so strongly on the attention they attract.Comment: 6 pages, 6 figure

SILAC-based phosphoproteomics reveals an inhibitory role of KSR1 in p53 transcriptional activity via modulation of DBC1

BACKGROUND We have previously identified kinase suppressor of ras-1 (KSR1) as a potential regulatory gene in breast cancer. KSR1, originally described as a novel protein kinase, has a role in activation of mitogen-activated protein kinases. Emerging evidence has shown that KSR1 may have dual functions as an active kinase as well as a scaffold facilitating multiprotein complex assembly. Although efforts have been made to study the role of KSR1 in certain tumour types, its involvement in breast cancer remains unknown. METHODS A quantitative mass spectrometry analysis using stable isotope labelling of amino acids in cell culture (SILAC) was implemented to identify KSR1-regulated phosphoproteins in breast cancer. In vitro luciferase assays, co-immunoprecipitation as well as western blotting experiments were performed to further study the function of KSR1 in breast cancer. RESULTS Of significance, proteomic analysis reveals that KSR1 overexpression decreases deleted in breast cancer-1 (DBC1) phosphorylation. Furthermore, we show that KSR1 decreases the transcriptional activity of p53 by reducing the phosphorylation of DBC1, which leads to a reduced interaction of DBC1 with sirtuin-1 (SIRT1); this in turn enables SIRT1 to deacetylate p53. CONCLUSION Our findings integrate KSR1 into a network involving DBC1 and SIRT1, which results in the regulation of p53 acetylation and its transcriptional activity

Concepciones culturales del VIH/Sida de adolescentes de Bolivia, Chile y México

OBJETIVO: Comprender las dimensiones culturales del VIH/Sida de estudiantes adolescentes. MÉTODOS: Estudio antropológico cognitivo. Realizado en Cochabamba (Bolivia), Talca (Chile) y Guadalajara (México) entre 2007 y 2008. Un total de 184 jóvenes (de 14 y 19 años de edad) fueron seleccionados por muestreo propositivo en centros de estudios de educación media superior de cada país. Fueron utilizadas las técnicas de listados libres y el sorteo de montones. Se indagaron términos asociados al concepto VIH/Sida y grupos de dimensiones conceptuales. Posteriormente se aplicó análisis de consenso mediante factorización de componentes principales y análisis dimensional mediante conglomerados jerárquicos y escalas multidimensionales. RESULTADOS: Las diferencias entre los contextos fueron en el grado de consenso en relación al término de VIH/Sida, ya que fue mayor en Cochabamba. En Talca y Guadalajara los jóvenes mencionaron metáforas de lucha frente a la enfermedad, mientras en Cochabamba se refirieron a la ayuda, apoyo y amor que las personas infectadas deberían recibir. Las coincidencias entre las conceptualizaciones de los jóvenes de los tres países fueron: los riesgos (las prácticas sexuales desprotegidas y el contacto con algunos grupos poblacionales específicos), las consecuencias (muerte física y social, entendida ésta última como el rechazo de la sociedad hacia los enfermos) y la prevención de la enfermedad (con base en la información así como uso del condón). CONCLUSIONES: Para los estudiantes adolescentes el VIH/Sida es una enfermedad causada por prácticas sexuales y consumo de drogas que implica daño, dolor y muerte. Los programas preventivos del VIH/Sida para los adolescentes deben promover la búsqueda de información sobre el tema con bases científicas, y no centrarse en las consecuencias emocionales y sociales de la enfermedad.OBJETIVO: Compreender as dimensões culturais do HIV/Aids por estudantes adolescentes. MÉTODOS: Estudo antropológico cognitivo realizado em Cochabamba (Bolívia), Talca (Chile) e Guadalajara (México), entre 2007 e 2008. O total de 184 jovens (de 14 e 19 anos de idade) foi selecionado por amostragem propositiva em centros de estudos de educação média superior de cada país. Foram utilizadas técnicas de listas livres e classificação da pilha. Foi feita a indagação de termos associados ao conceito HIV/Aids e grupos de dimensões conceituais. Posteriormente, fez-se análise de consenso mediante a fatorização dos componentes principais e análise dimensional mediante conglomerados hierárquicos e escalas multidimensionais. RESULTADOS: As diferenças entre os contextos foram no grau de consenso em relação ao termo HIV/Aids, que foi maior em Cochabamba. Em Talca e Guadalajara os jovens mencionaram metáforas de luta diante da doença, enquanto em Cochabamba eles referiram ajuda, apoio e amor que as pessoas infectadas deveriam receber. As coincidências entre as conceitualizações dos jovens dos três países foram: os riscos (as práticas sexuais desprotegidas e o contato com alguns grupos populacionais específicos), as conseqüências (morte física e social, entendida esta última como o rechaço da sociedade aos doentes) e a prevenção da doença (com base na informação e no uso do preservativo). CONCLUSIONES: Para os estudantes adolescentes, o HIV/Aids é uma doença causada por práticas sexuais e uso de drogas que envolve dano, dor e morte. Os programas preventivos do HIV/Aids para os e as adolescentes devem promover a busca de informação com bases científicas sobre o tema, e não só a que se centra nas conseqüências emocionais e sociais da doença.OBJECTIVE: To understand the cultural dimensions of HIV/AIDS among adolescent students. METHODS: A cognitive anthropological study was undertaken in Cochabamba (Bolivia), Talca (Chile) and Guadalajara (Mexico), during 2007 and 2008. A total of 184 teenagers (from 14 to 19 years old) were selected by purposeful sampling at secondary schools in each country. Free association lists and pile sorts were utilized. Terms associated with the concept of HIV/AIDS and groups of conceptual dimensions were investigated. Subsequently, consensus analysis was performed using factorial principal components and dimensional analysis through hierarchical clusters and multidimensional scales. RESULTS: The differences between the country contexts were in the degree of consensus in relation to the term HIV/AIDS, which was greater in Cochabamba. In Talca and Guadalajara the youths mentioned metaphors of fighting against HIV/AIDS, while in Cochabamba participants talked about help, support and love that infected people should receive. The similarities among conceptions by youth from the three countries were: the risk factors (unprotected sexual practice and contact with specific population groups), the consequences (physical and social death, being the latter understood as social rejection of people living with HIV/AIDS) and the prevention of illness (based on information and condom use). CONCLUSIONS: For adolescent students, HIV/AIDS is a disease caused by sexual practices and drug use and involves harm, pain and death. HIV/AIDS prevention programs for adolescents should promote science based information on the topic and not concentrate only on the emotional and social consequences of HIV/AIDS

An assessment of opportunities and challenges for public sector involvement in the maternal health voucher program in Uganda

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Continued inequities in coverage, low quality of care, and high out-of-pocket expenses for health services threaten attainment of Millennium Development Goals 4 and 5 in many sub-Saharan African countries. Existing health systems largely rely on input-based supply mechanisms that have a poor track record meeting the reproductive health needs of low-income and underserved segments of national populations. As a result, there is increased interest in and experimentation with results-based mechanisms like supply-side performance incentives to providers and demand-side vouchers that place purchasing power in the hands of low-income consumers to improve uptake of facility services and reduce the burden of out-of-pocket expenditures. This paper describes a reproductive health voucher program that contracts private facilities in Uganda and explores the policy and implementation issues associated with expansion of the program to include public sector facilities. Methods: Data presented here describes the results of interviews of six district health officers and four health facility managers purposefully selected from seven districts with the voucher program in southwestern Uganda. Interviews were transcribed and organized thematically, barriers to seeking RH care were identified, and how to address the barriers in a context where voucher coverage is incomplete as well as opportunities and challenges for expanding the program by involving public sector facilities were investigated. Results: The findings show that access to sexual and reproductive health services in southwestern Uganda is constrained by both facility and individual level factors which can be addressed by inclusion of the public facilities in the program. This will widen the geographical reach of facilities for potential clients, effectively addressing distance related barriers to access of health care services. Further, intensifying ongoing health education, continuous monitoring and evaluation, and integrating the voucher program with other services is likely to address some of the barriers. The public sector facilities were also seen as being well positioned to provide voucher services because of their countrywide reach, enhanced infrastructure, and referral networks. The voucher program also has the potential to address public sector constraints such as understaffing and supply shortages.Conclusions: Accrediting public facilities has the potential to increase voucher program coverage by reaching a wider pool of poor mothers, shortening distance to service, strengthening linkages between public and private sectors through public-private partnerships and referral systems as well as ensuring the awareness and buy-in of policy makers, which is crucial for mobilization of resources to support the sustainability of the programs. Specifically, identifying policy champions and consulting with key policy sectors is key to the successful inclusion of the public sector into the voucher program