Light scattering and atomic force microscopy study of InAs island formation on InP

Some aspects of the morphology of InAs island formation on InP have been studied by atomic force microscopy, photoluminescence, photoluminescence excitation spectroscopy, and Raman scattering. The InAs layer is grown by chemical beam epitaxy on top of InP surfaces with sawtooth-like channels. The deposition of a thin InAs layer results in quantum dots strongly aligned along the InP channels. Subsequent annealing in an arsenic atmosphere produces growth and loss of coherency of the islands. Atomic force microscopy shows the changes in size and alignment of the islands. Optical measurements serve to give quantitative estimates of the strain distribution among the top of the InP buffer layer, the wetting layer and the islands for the differently treated samples. (C) 2000 American Institute of Physics. [S0021-8979(00)02003-X].8731165117

On the optical properties of InAs/InP systems: The role of two-dimensional structures and three-dimensional islands

We investigate the effects of the interface morphology on the electronic properties of InAs/In systems using in-air atomic force microscopy and low temperature photoluminescence. Atomic force microscopy results show that the distribution of InAs strained film into three-dimensional islands and the two-dimensional wetting layer-typical of the Stranski-Krastanov growth mode-is strongly affected by the characteristics of the substrate and by the morphology of the InP buffer layer. The differences in the optical data are correlated to the different interface characteristics observed by atomic force microscopy. We discuss the origin of emission peaks taking into account the diffusion process of adsorbed atoms on the different types of surface. (C) 1998 American Institute of Physics.7291015101

Optical properties of multi-layer type II InP/GaAs quantum dots studied by surface photovoltage spectroscopy

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We present a low-temperature (73 K) study of the optical properties of multi-layer type II InP/GaAs self-assembled quantum dots by means of surface photovoltage (SPV) spectroscopy, taking advantage of its high sensitivity and contactless nature. The samples contain 10 periods of InP quantum dot planes separated by 5 nm GaAs spacers. The SPV amplitude spectra reveal two major broad peaks, situated at low and high energies, respectively. These features are analyzed taking into account the type II character of the structure, the quantum coupling effects, the spectral behavior of the SPV phase, and the photoluminescence spectra. As a result they have been attributed to optical transitions in the quantum dots and the wetting layers, respectively. The main mechanism for carrier separation in the SPV generation process is clarified via the analysis of the SPV phase spectra. The influence of the substrate absorption on the SPV spectra is discussed in details. (C) 2011 American Institute of Physics. [doi:10.1063/1.3638705]1106Bulgarian National Science Fund [D01-463/12.7.06]Alexander von Humboldt FoundationCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Bulgarian National Science Fund [D01-463/12.7.06

Inequalities in public water supply fluoridation in Brazil: An ecological study

Background. The literature is scarce on the social and geographic inequalities in the access to and implementation of the fluoridation of public water supplies. This study adds knowledge to the Brazilian experience of the chronic privation of water and wastewater policies, access to potable water and fluoridation in the country. Thus, the aim of this study was to verify possible inequalities in the population's access to fluoridated drinking water in 246 Brazilian municipalities. Methods. The information on the process of water fluoridation in the municipalities and in the macro region in which each municipality is located was obtained from the national epidemiological survey which was concluded in 2003. The data relating to the human development index at municipal level (HDI-M) and access to mains water came from the Brazilian Human Development Atlas, whilst the size of the population was obtained from a governmental source. The Fisher exact test (P < 0.05) was employed to identify significant associations between the explanatory variables and their ability to predict the principal outcomes of interest to this study, namely the presence or absence of the water fluoridation process in the municipalities as well as the length of time during which this measure has been implemented. Linear regression was used to observe the associations between the relevant variables in a multivariate environment. Results. The results clearly showed that there is a relationship between municipalities with larger populations, located in more socio-economically advantaged regions and with better HDI-M, and where fluoridation is both present and has been implemented for a longer period of time (started before 1990). Conclusion. The findings suggest that the aim of treating water with fluoride may not be being adequately achieved, requiring more effective strategies so that access to this measure can be expanded equitably.81Hart, J.T., The inverse care law (1971) Lancet, 1 (7696), pp. 405-12. , 4100731Victora, C.G., Vaughan, J.P., Barros, F.C., Silva, A.C., Tomasi, E., Explaining trends in inequities: Evidence from Brazilian child health studies (2000) Lancet, 356 (9235), pp. 1093-98. , 10.1016/S0140-6736(00)02741-0 11009159Basting, R.T., Pereira, A.C., Meneghim, M.C., Evaluation of dental caries prevalence in students from Piracicaba, SP, Brazil, after 25 years of fluoridation of the public water supply (1997) Rev Odontol Univ São Paulo, 11 (4), pp. 287-92. , 10.1590/S0103-06631997000400010Lawrence, H.P., Sheiham, A., Caries progression in 12 to 16-year-old schoolchildren in fluoridated and fluoride-deficient areas in Brazil (1997) Community Dent Oral Epidemiol, 25 (6), pp. 402-11. , 10.1111/j.1600-0528.1997.tb01730.x 9429812Pereira, A.C., Mialhe, F.L., Bianchini, F.L.C., Prevalence of caries and dental floozies in scholars from cities with different fluoride concentrations in drinking water (2001) Rev Bras Odontol Sade Coletiva, 2 (1), pp. 34-9For Disease Control, C., Prevention, Achievementsin Public Health, 1900-1999: Fluoridation of drinking water to prevent dental caries (1999) Morbidity and Mortality Weekly Report, 48 (41), pp. 933-40For Disease Control, C., Prevention, Ten great public health achievements -United Sates, 1900-1999 (1999) Morbidity and Mortality Weekly Report, 48 (12), pp. 241-3. , 10220250American Health Organization, P., XV Directing Council of the Pan American Health Organization - Resolutions, 1964, , http://www.paho.org/English/GOV/CD/ftcd_15.htm(2003) The World Oral Health Report 2003, , http://www.who.int/oral_health, Geneva: WHOMcDonagh, M.S., Whiting, P.F., Wilson, P.M., Sutton, A.J., Chestnutt, I., Cooper, J., Misso, K., Kleijnen, J., Systematic review of water fluoridation (2000) BMJ, 321 (7265), pp. 855-9. , 11021861 10.1136/bmj.321.7265.855Bratthall, D., Hänsel-Petersson, G., Sundberg, H., Reasons for the caries decline: What do the experts believe? (1996) Eur J Oral Sci, 104 (4 PART 2), pp. 416-22. , 10.1111/j.1600-0722.1996.tb00104.x 8930592Narvai, P.C., Dental caries and fluorine: A twentieth century relation (2000) Cinc Sade Coletiva, 5 (2), pp. 381-92. , 10.1590/S1413-81232000000200011Peres, M.A., Fernandes, L.S., Peres, K.G., Inequality of water fluoridation in Southern Brazil - The inverse equity hypothesis revisited (2004) Soc Sci Med, 58 (6), pp. 1181-9. , 10.1016/S0277-9536(03)00289-2 14723912Peres, M.A., Antunes, J.L.F., Peres, K.G., Is water fluoridation effective in reducing inequalities in dental caries distribution in developing countries? (2006) Sozial und Präventiv Medizin, 51 (5), pp. 1-9Peres, K.G., Bastos, J.R., Mrdo, L., Relationship between severity of dental caries and social and behavioral factors in children (2000) Rev Saude Publica, 34 (4), pp. 402-8. , 10973161Maltz, M., Barbachan Silva, E.B., Relationship between caries, gingivitis and fluorosis and the socioeconomic status among school children (2001) Rev Saude Publica, 35 (2), pp. 170-6. , 11359204Moysés, S.J., Desigualdades em Sade Bucal e Desenvolvimento Humano: Um ensaio em preto, branco e alguns tons de cinza (2001) Rev Bras Odontol Sade Coletiva, 1 (1), pp. 7-17Patussi, M.P., Marcenes, W., Croucher, R., Sheiham, A., Social deprivation, income inequality, social cohesion and dental caries in Brazilian school children (2001) Soc Sci Med, 53 (7), pp. 915-25. , 10.1016/S0277-9536(00)00391-9 11522137Antunes, J.L.F., Frazão, P., Narvai, P.C., Bispo, C.M., Pegoretti, T., Spatial analysis to identify differentials in dental needs by area-based measures (2002) Community Dent Oral Epidemiol, 30 (2), pp. 133-42. , 10.1034/j.1600-0528.2002.300207.x 12000354Peres, M.A., Peres, K.G., Antunes, J.L.F., Junqueira, S.R., Frazão, P., Narvai, P.C., The association between socioeconomic development at the town level and the distribution of dental caries in Brazilian children (2003) Rev Panam Salud Publica, 14 (3), pp. 149-57. , 10.1590/S1020-49892003000800001 14653902Antunes, J.L.F., Narvai, P.C., Nugent, Z.J., Measuring inequalities in the distribution of dental caries (2004) Community Dent Oral Epidemiol, 32 (1), pp. 41-8. , 10.1111/j.1600-0528.2004.00125.x 14961839Antunes, J.L.F., Peres, M.A., De Campos Mello, T.R., Waldman, E.A., Multilevel assessment of determinants of dental caries experience in Brazil (2006) Community Dent Oral Epidemiol, 34 (2), pp. 146-152. , 10.1111/j.1600-0528.2006.00274.x 16515679Narvai, P.C., Frazão, P., Roncalli, A.G., Antunes, J.L.F., Dental caries in Brazil: Decline, polarization, inequality and social exclusion (2006) Rev Panam Salud Publica, 19 (6), pp. 385-93. , 10.1590/S1020-49892006000600004 16968593Projeto, S.B., Brasil, Condiçes de sade bucal da população brasileira 2002-2003. Resultados principais (2004) Brasília-DF: Ministério da Sade, Secretaria de Atenção Sade, Departamento de Atenção Básica, Coordenação Nacional de Sade BucalCarmichael, C.L., Rugg-Gunn, A.J., French, A.D., Cranage, J.D., The effect of fluoridation upon the relationship between caries experience and social class in 5-year-old children in Newcastle and Northumberland in 1987 (1980) Br Dent J, 149 (6), pp. 163-7. , 10.1038/sj.bdj.4804479 6931610Bradnock, G., Marchment, M.D., Anderson, R.J., Social background, fluoridation and caries experience in 5-year-old population in the West Midlands (1984) Br Denl J, 156 (4), pp. 127-31. , 10.1038/sj.bdj.4805287 6584119Jones, C.M., Taylor, G.O., Whittle, J.G., Evans, D., Trotter, D.P., Water fluoridation, tooth decay in 5 years olds, and social deprivation measured by the Jarman score: Analysis of data from British dental surveys (1997) BMJ, 315 (7107), pp. 514-17. , 9329305Riley, J.C., Lennon, M.A., Ellwood, R.P., The effect of water fluoridation and social inequalities on dental caries in 5-year-old children (1999) Int Dent J, 28 (2), pp. 300-5. , 10342695Congresso Nacional, Brasil., Lei Federal no. de 19/09/1990 (1990) Diário Oficial da União 20 Set, p. 18055Morgenstern, H., Ecological studies (1998) Modern Epidemiology, pp. 459-80. , Baltimore: Lippincot Williamns & Wilkins Rothman K, Greenland S(2000) Informaçes de Sade: População Residente, , http://w3.datasus.gov.br/datasus/datasus.php?area= 359A1B379C6D0E0F359G23HIJd6L26M0N&VInclude=./site/infsaude.php, Departamento de Informática do Sistema nico de Sade (DATASUS)(2003) Atlas Do Desenvolvimento Humano No Brasil, Versão 1.0.0, , Programa das Naçes Unidas para o Desenvolvimento Brasília: PNUDLallo, R., Myburgh, N.G., Hobdell, M.H., Dental caries, socio-economic development and national oral health profiles (1999) Int Dent J, 49, pp. 196-202. , 10858754Baldani, M.H., Narvai, P.C., Antunes, J.L.F., Cárie dentária e condiçes scio-econômicas no Estado do Paraná, Brasil, 1996 (2002) Cad Sade Pblica, 18 (3), pp. 755-63. , 10.1590/S0102-311X2002000300024Qizilbash, M., On the Measurement of Human Development (2002) UNDP, , http://hdr.undp.org/docs/training/oxford/presentations/ Qizilbash_HDIcritique.pdfBurt, B.A., Fluoridation and social equity (2002) J Public Health Dent, 62 (4), pp. 195-200. , 10.1111/j.1752-7325.2002.tb03445.x 12474623For Disease Control, C., Prevention, Recommendation focusing fluoride to prevent and control dental caries in the United States (2001) Morbidity and Mortality Weekly Report, 50 (14), pp. 1-42Griffin, S.O., Jones, K., Tomar, S.L., An economic evaluation of community water fluoridation (2001) J Public Health Dent, 61 (2), pp. 78-86. , 10.1111/j.1752-7325.2001.tb03370.x 11474918Bleicher, L., Frota, F.H.S., Fluoretação da água: Uma questão de política pblica - O caso do Estado do Ceará (2006) Cin Sade Coletiva, 11 (1), pp. 71-8Frias, A.C., Narvai, P.C., Arajo, M.E., Zilbovicius, C., Antunes, J.L.F., Custo da fluoretação das águas de abastecimento pblico, estudo de caso -Município de São Paulo, Brasil, período de 1985-2003 (2006) Cad Sade Pblica, 22 (6), pp. 1237-46. , 10.1590/S0102-311X2006000600013Congresso Nacional, Brasil., (1974) Lei Federal No. 6.050, 3, p. 107. , Brasília: Departamento de Imprensa Nacional Atos do Poder Legislativo. 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Clinical Outcomes of Thirteen Patients with Acute Chagas Disease Acquired through Oral Transmission from Two Urban Outbreaks in Northeastern Brazil

Chagas disease is caused by a parasitic protozoan transmitted to humans by the contaminated feces of blood-feeding assassin bugs from the Triatominae subfamily. It may also be transmitted from mother to baby during pregnancy, by breastfeeding, blood transfusion or organ transplant. In rare cases, the disease can also be caused by accidental ingestion of contaminated food (sugar cane or açaí juice, drinking water, etc.). Acute Chagas disease often presents itself as a mononucleosis-like syndrome, with symptoms including fever, lymph node enlargement and muscle pain. The mortality rate of acute Chagas disease is high, mainly due to heart failure as a consequence of cardiac fiber lesions. There are few studies describing clinical outcomes and the disease progression of patients who receive therapeutic treatment, especially with regard to cardiac exam findings. In this report, the authors describe clinical findings from two micro-outbreaks occurring in impoverished towns in northeastern Brazil. Prior to receiving treatment, patient mortality rate was 28.6% in one of the outbreaks, and one pregnant woman experienced a spontaneous abortion due to the disease in the other outbreak. Most patients complained of fever, dyspnea, myalgia and periorbital edema. After receiving a two-month course of treatment, clinical symptoms improved and the number of abnormalities in cardiac exams decreased

CONTRIBUCIONES Y COMPLICACIONES DE MICHEL MAFFESOLI EN EL ESTUDIO DE LAS NEOCOMUNIDADES ESTUDIANTILES POSTMODERNAS1

En este texto se debaten las implicaciones de los aportes teóricos de Michel Maffesoli (1998; 2003; 2005a; 2005b; 2005c) en el campo de la investigación educativa. Este autor invita a los científicos sociales a contemplar la “respiración social” propia del espacio civilizatorio actual, donde han caído el mito de progreso, los proyectos futuristas y los grandes ideales utópicos. Dentro de esta realidad, cada día una mayor cantidad de jóvenes se muestran irreverentes a la pertinencia de la educación en sus vidas y centran sus expectativas de futuro en sus propias conquistas personales y están fuertemente marcados por una cultura presentista que favorece el disfrute inmediato en detrimento del trabajo, el esfuerzo y la postergación del placer. Estos jóvenes componen las “neocomunidades estudiantiles postmodernas” siendo común entre ellos “deserción” “repititencia” “exclusión” y “fracaso escolar”, su crecimiento constante invita a los investigadores educativos a generar estudios que partan de una lógica sensible (Maffesoli, 1998) y no la lógica del deber ser que tradicionalmente imperó en la ciencia moderna.Palabras Clave: Postmodernidad, Juventudes, Investigación en Educación.MICHEL MAFFESOLI´S CONTRIBUTIONS AND COMPLICATIONS IN THE STUDY OF POSTMODERN STUDENT COMMUNITIESAbstractA this paper it`s discuss implications of the theoretical contributions of Michel Maffesoli (1998; 2003; 2005a; 2005b; 2005c) in the field of the educational research. This writher invites social scientists to contemplate the social breathing of present civilization, in which progress myths, futurist projects and great utopical ideals have fallen. Within this reality, a greater amount of young people have become every day irreverent in front of educational demands. They seems to focus their future expectations in their own personal conquests, strongly marked by a culture of present that favors pleasure here and now, as opposed to work, endurance and postponement. These youngsters integrate students post modern neo-communities where it is common to find school dropouts and all sort of failures and socially excluded people. These neo-communities are growing steadily, inviting us to study the situation from a sensitive logic (Maffesoly, 1998) as opposed to the rational tradition used in modern science. Key words: Postmodernity, Youths, Research in Education.