Batch size estimate

In this work we analyze the main batch resolution algorithms. We particularly focus on the tree-based class to underline how their efficiency depends on the batch size. In fact, batch size is a critical parameter when using smart resolution strategies that take advantage this information to improve resolution efficiency. The dissertation will continue with the analysis of noteworthy techniques available in literature for the batch size estimate: in fact, original papers pay attention on the resolution process and leave the estimate problem in the background. Finally we propose and analyze GEGA, an estimate algorithm particularly good in terms of estimate accuracy over time taken by the estimate process.ope

¿De la deslocalización al "backshoring"? Evidencia de los distritos industriales italianos

In recent decades, industrial districts (ID) have experienced intense delocalisation to low-cost countries, with implications for IDs’ internal structure. Recent studies, however, highlight the advantages of relocalising manufacturing in home countries. This paper investigates ID firms’ production-location strategies and backshoring decisions. The results from a survey of 259 firms in eight Italian IDs show that firms that delocalise production do not change their strategies over time and make limited recourse to backshoring. ID production is still important to guarantee product quality and access to specialised know-how.En las últimas décadas, los distritos industriales experimentaron una deslocalización intensa hacia países de bajo costo, con implicaciones en la estructura interna del distrito. Estudios recientes destacan las ventajas de volver a localizar la producción en el mercado nacional. Este artículo analiza las estrategias de localización de las empresas del distrito de producción y las decisiones de “backshoring”. El trabajo empírico consiste en un análisis descriptivo de 259 empresas ubicadas en 8 distritos industriales en Italia. Los resultados muestran que las empresas que deslocalizaron la producción no han cambiado sus estrategias con el tiempo, con un limitado recurso al “back-shoring”. No obstante, la producción del distrito es todavía importante para garantizar la calidad del producto y el acceso a un “know-how” especializado

Is this time different?: how Industry 4.0 affects firms' labor productivity

Does Industry 4.0 technology adoption push firms’ labor productivity? We contribute to the literature debate—mainly focused on robotics and large firms—by analyzing adopters’ labor productivity returns when micro, small, and medium enterprises (MSME) are concerned. We employ original survey data on Italian MSMEs’ adoption investments related to a multiplicity of technologies and rely on a difference-in-differences estimation strategy. Results highlight that Industry 4.0 technology adoption leads to a 7% increase in labor productivity. However, this effect decreases over time and is highly heterogeneous with respect to the type, the number, and the variety of technologies adopted. We also identify potential channels explaining the labor productivity returns of technology adoption: cost-related efficiency, new knowledge creation, and greater integration/collaboration both within the firm and with suppliers

Risk factors for the increasing trend in low birth weight among live births born by vaginal delivery, Brazil

OBJECTIVE: To identify risk factors for low birth weight (LBW) among live births by vaginal delivery and to determine if the disappearance of the association between LBW and socioeconomic factors was due to confounding by cesarean section. METHODS: Data were obtained from two population-based cohorts of singleton live births in Ribeirão Preto, Southeastern Brazil. The first one comprised 4,698 newborns from June 1978 to May 1979 and the second included 1,399 infants born from May to August 1994. The risks for LBW were tested in a logistic model, including the interaction of the year of survey and all independent variables under analysis. RESULTS: The incidence of LBW among vaginal deliveries increased from 7.8% in 1978--79 to 10% in 1994. The risk was higher for: female or preterm infants; newborns of non-cohabiting mothers; newborns whose mothers had fewer prenatal visits or few years of education; first-born infants; and those who had smoking mothers. The interaction of the year of survey with gestational age indicated that the risk of LBW among preterm infants fell from 17.75 to 8.71 in 15 years. The mean birth weight decreased more significantly among newborns from qualified families, who also had the highest increase in preterm birth and non-cohabitation. CONCLUSIONS: LBW among vaginal deliveries increased mainly due to a rise in the proportion of preterm births and non-cohabiting mothers. The association between cesarean section and LBW tended to cover up socioeconomic differences in the likelihood of LBW. When vaginal deliveries were analyzed independently, these socioeconomic differences come up again.OBJETIVO: Identificar fatores de risco para o baixo peso ao nascer (BPN) entre nascidos vivos de parto vaginal e verificar se o desaparecimento da associação entre BPN e fatores socioeconômicos foi devido ao confundimento pela cesariana. MÉTODOS: Foram estudadas duas coortes de base populacional de recém-nascidos únicos de parto vaginal em Ribeirão Preto, Sudeste do Brasil. A primeira incluiu 4.698 crianças nascidas entre junho de 1978 e maio de 1979 e a segunda 1.399 crianças nascidas entre maio e agosto de 1994. Os riscos de BPN foram testados num modelo de regressão logística, incluindo interações entre ano da pesquisa e todas as variáveis independentes em análise. RESULTADOS: A incidência de BPN entre partos vaginais aumentou de 7,8% em 1978/79 para 10% em 1994 para crianças do sexo feminino, para os primogênitos, para nascidos de mães sem companheiro, para nascidos de mães que fizeram menor número de consultas pré-natais ou com menos anos de estudo e para nascidos de mães fumantes. A interação entre ano do parto e idade gestacional indicou que o risco de BPN entre os nascidos prematuros caiu de 17,8 para 8,7 em 15 anos. A média do peso ao nascer reduziu-se mais entre os filhos de famílias mais qualificadas, que tiveram o maior aumento nos nascimentos pré-termo e nas mães sem companheiro. CONCLUSÕES: O BPN entre partos vaginais aumentou principalmente devido ao incremento nos nascimentos pré-termo e nas mães sem companheiro. A associação entre cesariana e BPN tendeu a encobrir as diferenças socioeconômicas na probabilidade do BPN. Na análise dos partos vaginais isoladamente, as diferenças socioeconômicas reapareceram

Comparison of methods for final height assessment in adolescents with a normal variant short stature

Introduction: patients with low stature normal variant growth have peculiar evolutionary patterns making it difficult to precisely define when final stature will be reached, since prediction methods are based on parameters of difficult quantification, such as bone age. Objective: To assess the agreement between two methods for prediction of final height based on family target range regarding the final height reached by adolescents with a diagnosis of normal variant short stature.  Methods: Thirty-three subjects were evaluated using height of parents for the calculation of family target range and Bayley-Pinneau and Tanner-Whitehouse methods for prediction of final height. Spearman correlation coefficient was calculated to correlate final height with the mean of the family target range, and the St. Laurent concordance coefficient was used to assess concordance between final stature and predictive methods. Results:  87.9% (29/33) subjects kept short stature at the end of growth and 90.9% (30/33) had a final height within family target range. A very strong positive correlation (Cs = 0.77; p < 0.01) was observed between parental mean and final height. Bayley-Pinneau method showed a 0.47 concordance coefficient with final height (95% CI: 0.34; 0.57), and Tanner-Whitehouse 3 method showed a concordance coefficient of 0.58 (95% CI: 0.41; 0.75). Conclusion: The strong positive correlation observed demonstrates the significant influence of parental height on final height. Neither method showed good concordance when used as a predictor of final height, with height values being overestimated

Diferença notável nas taxas de parto cesariano em hospital público e hospital privado no Brasil

This paper evaluates the association of maternal variables and of variables related to prenatal and delivery care with cesarean sections at a public and at a private maternity. A retrospective cross-sectional study was performed at a public maternity clinic (2,889 deliveries) and at a private maternity clinic (2,911 deliveries) in the city of Ribeirão Preto, São Paulo State, Brazil. The prevalence of cesarean sections was 18.9% at the public maternity clinic and 84.3% at the private one. The factors associated with cesarean sections at both hospitals were: mothers from other cities, aged > 25 years and with hypertension. Having more than one child was a protective factor. At the public hospital, cesarean sections were more frequent on Wednesdays and from 12:00 to 23:59 hours of any day of the week, whereas at the private hospital they occurred on any day, though were less common on Sundays, and at any time except in the early morning. At the private hospital, cesarean sections were more frequent when performed by the doctor who had provided the prenatal care. Non-medical factors were more associated with cesarean sections in the private maternity clinic than biological or clinical factors related to pregnancy.Este artigo avalia a associação de variáveis maternas e aquelas relacionadas ao cuidado pré-natal e ao parto com a ocorrência de cesáreas em um hospital público e em um hospital privado. Um estudo de corte transversal, retrospectivo, foi desenvolvido em uma maternidade pública (2.889 partos) e em uma maternidade privada (2.911 partos) em Ribeirão Preto, São Paulo, Brasil. A prevalência de cesárea foi 18,9% e 84,3%, respectivamente, na maternidade pública e na particular. Os fatores associados ao parto cesariano nos dois hospitais foram: mães procedentes de outras cidades, com idade > 25 anos e hipertensas. Ter mais de um filho foi fator protetor. No hospital público, a cesárea foi mais freqüente às quartas-feiras e das 12h00min às 23h59min de qualquer dia da semana, enquanto no hospital privado prevaleceram em qualquer dia, exceto aos domingos, e em qualquer horário, exceto de madrugada. Neste hospital, a cesárea foi mais freqüente quando realizada pelo médico que acompanhou o pré-natal. Fatores não médicos foram mais associados com os partos operatórios na maternidade privada do que fatores biológicos ou clínicos das gestantes

Insufficient birth weight: factors associated in two cohorts of newborns in Ribeirão Preto, São Paulo, Brazil

OBJETIVO: Avaliar fatores associados ao aumento das taxas de peso insuficiente (PI) em duas coortes de recém-nascidos (RN) vivos e de parto único de Ribeirão Preto, São Paulo, separadas por 15 anos (1978/79 e 1994). MÉTODOS: Foram estudados 6.223 partos em 1978/79 e 2.522 em 1994, excluindo-se os RN de baixo peso. Associação entre PI e variáveis independentes (idade, trabalho, escolaridade e tabagismo maternos, abortos e natimortos prévios, número de filhos, situação conjugal, visitas de pré-natal, tipo de parto e hospital, categoria de internação, renda familiar, idade gestacional e sexo do RN) foi analisada por cálculo da Odds Ratio (OR) bruto e intervalo de confiança 95%, seguida de regressão logística múltipla. RESULTADOS: Em 1978/79, na análise ajustada, idade materna <20 anos (p=0,014), renda familiar <5 salários-mínimos (p=0,030), menos de quatro consultas de pré-natais (p=0,003), parto vaginal (p<0,001), sexo feminino (p<0,001), tabagismo materno (p<0,001) e prematuridade (p<0,001) estiveram associados a PI. Em 1994, os fatores associados ao PI foram: trabalho materno fora do lar (p=0,020), sexo feminino (p<0,001), tabagismo materno (p<0,001) e prematuridade (p<0,001). CONCLUSÕES: Variáveis socioeconômicas que atuaram em 1978/79 desapareceram em 1994, restando o sexo do RN, o hábito de fumar e a prematuridade nos dois períodos. Como houve diminuição do tabagismo materno e não houve modificação na proporção de nascimentos do sexo feminino, uma explicação para o aumento do PI seria o aumento nos nascimentos pré-termo entre as duas coortes.OBJECTIVE: To evaluate factors associated to the increase in insufficient birth weight (IBW) rates in two population-based-cohorts of singletons born alive in Ribeirão Preto, São Paulo, Brazil, separated by 15 years (1978/79 and 1994). METHODS: The first cohort (1978/79) comprised 6,223 newborns and the second (1994), 2,522, excluding low birth weight newborns. Independent variables association with IBW (maternal age, work, schooling and smoking; previous abortion, previous stillbirth, number of live births, maternal marital status, family income, occupation group, type of hospital, mode of insurance, number of antenatal visits, type of delivery; newborn gender and gestational age) were analyzed. The Odds Ratio (OR) was determined using a logistic regression model and 95% confidence limits were calculated. RESULTS: In 1978/79, maternal age <20 years (p=0.014), family income <5 minimum Brazilian wages (p=0.030), <4 antenatal visits (p=0.003), vaginal delivery (p<0.001), female newborn gender (p<0.001), maternal smoking (p<0.001) and preterm birth (p<0.001) were associated with IBW. In 1994, maternal work outside home (p=0.020), female newborn gender (p<0.001), maternal smoking (p<0.001) and preterm births (p<0.001) were associated with IBW. CONCLUSIONS: Socioeconomics variables associated with IBW in 1978/79 were not determinants in 1994. Newborn gender, maternal smoking and preterm birth remained significant determinants of IBW in both moments. Considering the decrease in rate of maternal smoking and the maintenance of female births, the increase in IBW could be explained by increasing rates of preterm birth in this interval of 15 years.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Risk factors associated with preterm birth: identification, prediction and evaluation in the BRISA cohort

Problem: Preterm birth is the leading cause of death and can result in significant long-term loss of physical and psychological capacity among survivors.Background: An estimated 15 million babies are born preterm every year. Prediction models based on machine learning methods have reported promising results.Aims: To identify risk factors associated with preterm birth and to develop and validate a prediction model for this outcome in a Brazilian birth cohort.Methods: Cross-sectional study of all births that occurred in Ribeirão Preto-SP and of one in three births that occurred in São Luís-MA, Brazil, in 2010. Questionnaires were applied to obtain pregnancy-related data. Multivariate adaptive regression splines were used to determine the independent variables. Preterm birth, defined as birth before 37 weeks gestational age, was the dependent variable. A random forest model was developed and its performance was evaluated by ROC analysis.Findings: The preterm birth rates were 12.7% (RP) and 14.1% (SL). The prediction and validation accuracies of the RF-based model were 91.3% and 85.5% respectively. The model can be applied starting in the third month of gestation and is more effective in identifying preterm infants with GA&lt;31 weeks and 6 days (AUC=0.98).Discussion: It was possible to build a prediction model based on easily accessible low-cost data, without the need for complementary tests, providing results similar to those of other studies.Conclusions: Previous preterm birth and prenatal care were determinants. The use of an application for individualized patient monitoring an early stage can have positive effects on the quality of life of mother and child

Consumo de substâncias psicoativas por adolescentes escolares de Ribeirão Preto, SP (Brasil). I - Prevalência do consumo por sexo, idade e tipo de substância

INTRODUÇÃO: A preocupação suscitada quanto ao consumo de substâncias psicoativas pelos adolescentes tem mobilizado grandes esforços em todo o mundo na produção de conhecimento sobre este fenômeno. Decidiu-se estudar as taxas de prevalência de consumo de substâncias psicoativas de uso lícito e ilícito, sua distribuição por idade, sexo e a idade da primeira experiência com essas substâncias, entre adolescentes escolares do Município de Ribeirão Preto, SP, Brasil. MATERIAL DE MÉTODO: Um questionário devidamente adaptado e submetido a um teste de confiabilidade foi auto-aplicado a uma amostra proporcional de 1.025 adolescentes matriculados na oitava série do primeiro grau e primeiro, segundo e terceiro anos do segundo grau, das escolas públicas e privadas do município estudado. O questionário continha questões sobre o uso de dez classes de substâncias psicoativas, questões demográficas e informações de validação, além de questões de percepção e comportamento intrínseco ao consumo de drogas. RESULTADOS: Da amostra 88,9% consumiram bebidas alcoólicas alguma vez na vida; 37,7% utilizaram o tabaco; 31,1% os solventes; 10,5% os medicamentos; 6,8% a maconha; 2,7% a cocaína; 1,6% os alucinógenos e 0,3% consumiu alguma substância a base de opiácios. As taxas de consumo cresceram com a idade, para todas as substâncias; no entanto, o uso de tabaco e de substâncias ilícitas mostrou uma desaceleração nos anos que compreendem o final da adolescência. Verificou-se que os meninos consumiram mais do que as meninas, exceto para os medicamentos, com as meninas consumindo barbitúricos, anfetaminas e tranqüilizantes em proporções semelhantes ou maiores que os meninos. A idade da primeira experiência mostrou que o acesso às substâncias psicoativas ocorreu em idades bastante precoces. CONCLUSÕES: As substâncias psicoativas, sejam lícitas ou ilícitas, são freqüentemente experimentadas na adolescência, tanto pelos meninos como pelas meninas, muitas vezes em idades bem precoces.INTRODUCTION: Concern over the consumption of psychoactive substances by teenagers has given rise to a great wordwide effort to produce information about this phenomenon. This study set out to investigate the prevalence of consumption of legal and illegal psychoactive substances, its distribution by age, sex and age at first experience of them, among teenage pupils in county, Ribeirão Preto, SP, Southeastern Brazil. MATERIAL AND METHOD: A self-applicable questionnaire duly adapted and submitted to a reliability test was applied to a proportional sample of 1,025 teenagers enrolled in 8th, 9th, 10th and 11th grads at public and private city schools. The questionnaire contained questions about the use of ten classes of psychoactive substances, demographic questions and validation information, as well as questions about the perception and intrinsic behavior related to drug consumption. RESULTS: The sample of 88.9% had consumed alcoholic beverages sometime in their lives, 37.7% had used tobacco, 31.1% solvents, 10.5% medicines, 6.8% marihuana, 2.7% cocaine, 1.6% hallucinogens, and 0.3% of the sample had consumed some opiate substance. The rates of consumption increased with age for all substances; however, the use of tobacco and of illegal substances was less intense during the later years of adolescence. As to sex distribution, boys consumed more than girls, except for medicines, with girls consuming barbiturates, amphetamines and tranquilizers in proportions similar to or higher than those observed among boys. Age at first experience showed that access to psychoactive substances occurred at very early ages. CONCLUSIONS: Experimenting with psychoactive substances, whether legal or illegal, is a frequent phenomenon during adolescence, both among boys and girls, often at very early ages