ABSTRACT. The study of traits in crops enables breeders to guide strategies for selecting and accelerating the progress of genetic breeding. Although the simultaneous evaluation of characteristics in the plant breeding programme provides large quantities of information, identifying which phenotypic characteristic is the most important is a challenge facing breeders. Thus, this work aims to quantify the best approaches for prediction and establish a network of better predictive power in flood-irrigated rice via methodologies based on regression, artificial intelligence, and machine learning. Multiple regression, computational intelligence, and machine learning were used to predict the importance of the characteristics. Computational intelligence and machine learning were notable for their ability to extract nonlinear information from model inputs. Predicting the relative contribution of auxiliary characteristics in rice through computational intelligence and machine learning proved to be efficient in determining the relative importance of variables in flood-irrigated rice. The characteristics indicated to assist in decision making are flowering, number of grains filled by panicles and length of panicles for this study. The network with only one hidden layer with 15 neurons was observed to be efficient in determining the relative importance of variables in flooded rice.

Extraction of inbred lines is a very important step in maize breeding since these lines will be used to obtain hybrids intended for the market. However, this expensive process, hinders genotype evaluation in contrasting environments, especially regarding nitrogen (N) content. This study aimed to evaluate the potential of maize populations for line extraction and select partially inbred lines under different soil nitrogen (N) availability. Five populations were evaluated regarding their potential for line extraction. Fifty-five S1 partially inbred lines were extracted from these populations. The top-cross method was used to evaluate lines by crossing them with two testers. Hybrids evaluation used 110 top-cross hybrids, five base populations, and six checks. Two trials were carried out in Dourados and Caarapó. One trial had adequate fertilization (high N) while the other was under stress condition (low N). Hybrid DKB 789 showed potential for extraction of partially inbred lines, aiming at selecting N use efficiency. Base population BP (07) was the most suitable for the extraction of partially inbred lines aiming at N use efficiency. Partially inbred lines BP (07) 13, BP (07) 14, and BP (07) 17 are the most suitable for the extraction of top-cross hybrids with high grain yield, efficiency, and responsiveness to N.

La extracción de líneas endogámicas es un paso muy importante para el mejoramiento del maíz, ya que estas líneas se utilizan para obtener híbridos destinados al mercado. Sin embargo, este es un proceso costoso que dificulta la evaluación de genotipos en ambientes contrastantes, especialmente respecto del contenido de Nitrógeno edáfico. El objetivo de este estudio fue evaluar el potencial de las poblaciones de maíz para la extracción de líneas y seleccionar líneas parcialmente endogámicas con diferente respuesta a la disponibilidad de nitrógeno (N). Se evaluaron cinco poblaciones en cuanto a su potencial de extracción de líneas. A partir de estas poblaciones, se extrajeron cincuenta y cinco líneas S1 (parcialmente endogámicas). El método de top-cross se usó para evaluar líneas cruzándolas con dos probadores. La evaluación de los híbridos utilizó 110 híbridos superiores, cinco poblaciones base y seis controles. Se realizaron dos ensayos en Dourados and Caarapó, uno con una fertilización adecuada (alto N) y otro en condiciones de estrés (bajo N). El híbrido DKB 789 mostró potencial para extraer líneas parcialmente endogámicas con el objetivo de mejorar la eficiencia de uso de N. La población base BP (07) fue la más adecuada para la extracción de líneas parcialmente endogámicas destinadas a eficiencia de uso de N. Las líneas BP (07) 13, BP (07) 14 y BP (07) 17 son las más adecuadas para la extracción de híbridos top-cross con alto rendimiento de grano, eficiencia y capacidad de respuesta a N.

ABSTRACT. The effects of the dose and application method of limestone - broadcast or in furrow - and of agricultural gypsum on soil fertility, the control of clubroot, and cauliflower development in mountain farming areas were evaluated. Initially, four doses of broadcast limestone (0.0, 1.0, 2.0, and 4.0 Mg ha-1) and two cauliflower cultivars (Sharon and Piracicaba Precoce) were analyzed. A second experiment evaluated limestone (4.0 Mg ha-1) application treatments: broadcast and in furrow, broadcast limestone + gypsum (3.0 + 1.0 Mg ha-1), and broadcast gypsum (1.0 Mg ha-1). Soil fertility was improved, and significant increases were observed in the total and healthy root volume with increasing doses of limestone. With 4.0 Mg ha-1, a 58 and 85% increase in yield was observed in Sharon and Piracicaba, respectively, compared to the control. Treatments with limestone and limestone + gypsum, regardless of the application method, elevated pH (≥ 10%), base saturation (V%) (≥ 37%), and calcium (Ca) contents (≥ 100%), and reduced the levels of aluminum ions (Al3+) (≥ 60%) and clubroot severity (≥ 64%) and favored biomass accumulation (≥ 27%) and yield (≥ 9.2%). The application of limestone in the furrow yielded results similar to the broadcast application.

ABSTRACT An alternative to increase yield without raising the production costs and minimizing the dependence of agricultural inputs is the development of maize genotypes presenting high nitrogen (N) use efficiency under low N level conditions. Thus, the objective of this study was to estimate the specific combining ability of maize top-crosses under high and low nitrogen (N) conditions and to select high-yielding hybrids for both conditions. The grain yield of 110 top-cross hybrids was evaluated in 2012 in two locations in the Brazilian Midwest. Partial diallel analysis was performed with the adjusted means of each of the individual top-cross analyses. Specific combining ability (SCA) of the hybrids and their interaction with N levels was estimated for each location. The mean grain yield of the 11 hybrids selected by the highest SCA estimates for high and low N was higher than the controls mean in approximately 330 and 241 kg∙ha-1. These results demonstrate that the selection for each environment was efficient and reveals the possibility of developing new hybrids for the Brazilian Cerrado region.

ABSTRACT. The objective of this work was to estimate the general combining ability of partially inbred lines under high and low nitrogen (N) conditions and to select promising lines to obtain high yields for both conditions. Fifty-five partially inbred S1 progenies were evaluated using the top-cross method, where the lines were crossed with two testers. The 110 top-cross hybrids were evaluated for grain yield during the off-season of 2012 at two sites in the Brazilian Midwest. Partial diallel analysis was performed with the adjusted means of each of the individual analyses of the top crosses. The combining ability of partially inbred lines and testers as well as their interaction with N levels, was estimated for each site. The coefficient of concordance among 15 partially inbred lines selected by the highest general combining ability estimates for each N level was 0.60. The S1 lines 39, 11, 41, 55, 38, 37, 6, 8, and 14 were selected at both N levels. This indicates that these lines can be used to identify ideal hybrids for growing in the off-season in the Brazilian Midwest.

O objetivo deste trabalho foi estimar o ganho genético em pinhão-manso (Jatropha curcas) com uso de diferentes índices de seleção e estabelecer a melhor estratégia de seleção para a espécie. A seleção direta e indireta foi realizada com diferentes índices de seleção, o que totalizou 14 estratégias. Foram analisadas 175 famílias pertencentes ao banco ativo de germoplasma da Embrapa Agroenergia, em blocos ao acaso, com duas repetições. Foram avaliadas as variáveis: produtividade de grãos; sementes por fruto; razão endosperma/semente; peso, comprimento, largura e espessura de sementes; número de ramos a 0,5, 1,0 e 1,5 m; altura de plantas; diâmetro do caule; projeção da copa nas linhas e nas entrelinhas; volume da copa; juvenilidade (dias até o florescimento); e altura de inserção da primeira inflorescência. As avaliações foram realizadas durante o segundo ano de cultivo. A utilização de índices de seleção é relevante para maximizar os ganhos genéticos em pinhão-manso e favorece uma melhor distribuição de características desejáveis. Os índices multiplicativos e restritivos são considerados os mais promissores para uso na seleção.

The objective of this work was to estimate genetic gains in physic nut (Jatropha curcas) using selection indexes and to establish the best selection strategy for the species. Direct and indirect selection was carried out using different selection indexes, totalizing 14 strategies. One hundred and seventy five families from the active germplasm bank of Embrapa Agroenergy, Brasília, Brazil, were analyzed in a randomized complete block design with two replicates. The evaluated traits were: grain yield; seeds per fruit; endosperm/seed ratio; seed weight, length, width, and thickness; branches per plant at 0.5, 1.0, and 1.5 m; plant height; stem diameter; canopy projection on rows and between lines; canopy volume; juvenility (days to the first flowering); and height of the first inflorescence. Evaluations were done during the second year of cultivation. The use of selection indexes is relevant to maximize the genetic gains in physic nut, favoring a better distribution of desirable traits. The multiplicative and restrictive indexes are considered the most promising for selection.

A viabilidade de escleródios de Sclerotinia sclerotiorum foi avaliada durante oito meses em três solos de Cerrado cultivados. Escleródios produzidos "in vitro", mantidos em invólucros de náilon perfurados, foram enterrados a 5 cm de profundidade, em solos previamente fumigados ou não fumigados com brometo de metila. Após 10 dias de incubação, os escleródios foram examinados quanto à viabilidade e a presença de fungos antagônicos. A viabilidade foi estimada através do número de escleródios germinados 7 dias após plaqueamento em meio semi seletivo Neon-S. A viabilidade dos escleródios variou com o solo de Cerrado. Escleródios incubados em solos não fumigados com brometo de metila apresentaram menor viabilidade e maior presença de fungos antagônicos, indicando que estes solos contêm elementos supressivos de origem biológica. A viabilidade dos escleródios foi relacionada negativamente com a população de alguns microorganismos de solo. Nos tratamentos de maior incidência de Trichoderma spp. observou-se menor viabilidade de escleródios e solos fumigados suprimiram fortemente a ocorrência deste antagonista.

The viability of sclerotia of Sclerotinia sclerotiorum was assessed for eight months in three cultivated Cerrado soils. Sclerotia produced in vitro were placed in nylon mesh bags and buried 5 cm deep in soils either previously treated or untreated with methyl bromide. After 10 days of incubation, sclerotia were retrieved and were examined for viability and presence of antagonistic fungi. Viability was assessed based on the number of sclerotia germinated after a 7-day incubation period on semi-selective Neon-S medium. Viability of the sclerotia varied among Cerrado soils. Sclerotia from soils not treated with methyl bromide were less viable and were often contaminated by antagonistic fungi, indicating the presence of suppressive elements of biological origin in the untreated Cerrado soils. Sclerotium viability was negatively related to the population of some soil microorganisms. Treatments with higher incidences of Trichoderma spp. also presented lower sclerotium viability, and fumigation strongly suppressed this antagonist.

Geomorphometric variables are applied in digital soil mapping because of their strong correlation with the disposition and distribution of pedological components of the landscapes. In this research, the relationship between environmental components of tropical hillslope areas in the Rio de Janeiro State, Brazil, artificial neural networks (ANN), and maximum likelihood algorithm (MaxLike) were evaluated with the aid of geoprocessing techniques. ANN and MaxLike were applied to soilscape mapping and the results were compared to the original map. The ANN architectures with seven and five neurons in the hidden layer produced the best classifications when using samples obtained systematically. When random samples were applied, the best neural net architectures were within 22 and 16 neurons in the hidden layer. In conclusion, the ANN can contribute to soilscape surveys, making map delineation faster and less expensive. The digital elevation model (DEM) and its derived attributes can contribute to the understanding of the soil-landscape relationship of tropical hillslope areas; the use of artificial neural networks and MaxLike is feasible for digital soilscape mapping. The systematic sampling method provided a global accuracy of 70 % and 65.9 % for the ANN and the MaxLike, respectively. When the random sampling method was applied, the ANN had a global accuracy of 69.6 %, and the MaxLike had an accuracy of 62.1 %, considering the total study area in relation to the reference map.

O artigo apresenta resultados de pesquisa de avaliação sobre a qualidade da educação infantil no Brasil, desenvolvida em parceria com a Fundação Carlos Chagas, o Ministério da Educação e o Banco Interamericano de Desenvolvimento. Os dados foram colhidos em 147 instituições de educação infantil em seis capitais brasileiras, durante o segundo semestre de 2009. Para a observação dos ambientes de creches e pré-escolas foram utilizadas versões adaptadas das escalas Infant/Toddler Environment Rating Scale Revised Edition e Early Childhood Environment Rating Scale Revised Edition. Foram também aplicados questionários a diretores das instituições e professoras das turmas avaliadas. Os principais resultados revelaram que: creches e pré-escolas apresentam em média níveis de qualidade insatisfatórios; os níveis de qualidade mais comprometidos se referem às atividades (creche e pré-escola), rotinas de cuidado pessoal (creche) e estrutura do programa (pré-escola); mudanças em determinadas características das instituições poderiam levar à melhoria da qualidade da educação infantil nos municípios investigados

This article presents results from a research on the quality of Early Childhood Education in Brazil that was conducted in a collaborative effort between Fundação Carlos Chagas, the Ministry of Educations and the Inter-American Development Bank. Data were collected in 147 crèches and preschools in six state capitals, during the second semester of 2009. The instruments applied for the observation of classes were the translated versions of the Infant/Toddler Environment Rating Scale Revised Edition and the Early Childhood Environment Rating Scale Revised Edition. Questionnaires for principals and for teachers of the observed classes were also applied. The main results are: crèches and preschools average scores were in the basic level; the lowest scores received were related to Activities (crèche and preschool), Personal care routines (crèche), and Program structure (preschool); if changes were promoted in some of the institutions characteristics, those scores could be significantly improved

OBJETIVOS: Determinar a incidência de falha de extubação em recém-nascidos prematuros com peso de nascimento < 1.250 g extubados para pressão positiva contínua nas vias aéreas nasais e identificar os principais fatores de risco que possam estar associados à necessidade de reintubação nessa população. MÉTODOS: Análise retrospectiva dos prontuários de pacientes internados e ventilados mecanicamente durante o período de julho de 2002 a junho de 2004. Falha na extubação foi definida como necessidade de reintubação nos primeiros 7 dias após a primeira tentativa de extubação. RESULTADOS: Entre 52 pacientes estudados, 13 faleceram antes da primeira tentativa de extubação. Do restante, apenas nove falharam na extubação (23,1%). Comparando esses recém-nascidos com aqueles extubados com sucesso, houve diferença estatisticamente significativa em relação a peso de nascimento, idade gestacional e escore de Apgar no 5º minuto. Após a regressão logística, apenas a idade gestacional se manteve significativa. Alguns resultados secundários também foram significativamente diferentes: incidência de hemorragia intracraniana graus III e/ou IV, persistência do canal arterial e óbito. CONCLUSÕES: Nosso estudo demonstrou uma incidência de falha na extubação semelhante à da literatura. O principal fator de risco para falha nessa população foi a prematuridade (≤ 28 semanas). Nesses prematuros extremos, a implementação de estratégias para extubação precoce, o uso de metilxantinas, a prevenção da abertura do canal arterial e o uso de outros métodos de assistência ventilatória pós-extubação podem contribuir para a melhora desses resultados.

OBJECTIVES: To determine the incidence of extubation failure in preterm newborns with birth weight < 1,250 g extubated to nasal continuous positive airway pressure and to identify the main risk factors associated with the need for reintubation in this population. METHODS: A retrospective review of eligible infants admitted and mechanically ventilated between July 2002 and June 2004 was performed. Extubation failure was defined as the need for reintubation within 7 days after the first extubation attempt. RESULTS: Of the 52 patients included in the study, 13 died before the first extubation attempt. Of the remaining 39 patients, only nine failed extubation (23.1%) Comparing the two groups (failure vs. successful), there was a statistically significant difference regarding birth weight, gestational age and 5-minute Apgar score. After logistic regression, only gestational age was significant. Other secondary outcomes showed significant difference between the groups: intracranial hemorrhage grade III and/or IV, patent ductus arteriosus and death. CONCLUSIONS: The incidence of extubation failure in our population was similar to the rate reported in the literature. The main risk factor for extubation failure was prematurity (≤ 28 weeks). In this population of extreme preterm infants, implementation of strategies for early extubation, use of methylxanthines, prevention of patent ductus arteriosus, and use of different modes of assisted ventilation after extubation may improve the outcomes.

Este trabalho teve como objetivo avaliar o efeito da temperatura de armazenamento na viabilidade e vigor de sementes de angico (A. peregrina). As sementes utilizadas neste estudo foram colhidas na região de Viçosa, MG, em setembro de 2005, e armazenadas em câmara fria no Laboratório de Análise de Sementes Florestais (LASF) da Universidade Federal de Viçosa (UFV) por 150 dias, em uma temperatura de aproximadamente 5 ºC. A partir daí, as sementes foram armazenadas a aproximadamente a 20 ºC por mais 150 dias. O teor de água das sementes foi determinado após a secagem em estufa a 105 ± 3 ºC por 24 h. As sementes foram analisadas, mensalmente, pelo teste de germinação, teste de tetrazólio, teste de condutividade elétrica e osmocondicionamento, durante os 300 dias de armazenamento e com quatro repetições de 25 sementes. As sementes de A. peregrina mantiveram as porcentagens de germinação e a porcentagem de sementes viáveis pelo teste do tetrazólio constantes por cinco meses de armazenamento, tanto a 5 ºC quanto a 20 ºC. O teste de condutividade elétrica apresentou diferenças significativas em relação ao período de armazenamento, sendo mais sensível que o teste de germinação-padrão. O osmocondicionamento das sementes em solução de PEG -0,4 MPa não foi eficiente na recuperação da viabilidade e vigor das sementes armazenadas tanto a 5 ºC quanto a 20 ºC.

The aim of this experiment was to evaluate the effect of storage temperature on the viability and vigour of A. peregrina seeds. Seeds of A. peregrina harvested in Viçosa-MG, in September 2005 were used. The seeds were stored in the Laboratory of Forest Seeds Analysis (LASF) of the Universidade Federal de Viçosa (UFV), in a cold chamber, under approximately 5ºC over150 days. The seeds were stored under 20ºC for 150 days more. Seed moisture was determined after oven-drying at 105 ± 3ºC for 24 hours. The seeds were analyzed monthly using germination, tetrazolium and electrical conductivity tests and Osmopriming during 300 days, with four repetitions of 25 seeds. A. peregrina seeds kept a constant percentage of germination and viable seeds under the tetrazolium test for five months of storage, under either 5ºC and 20ºC. The electrical conductivity test showed significant differences in relation to the storage period, proving to be more sensitive than the standard germination test. Seed priming in PEG -0,4 MPa solution was not efficient in recovering the viability and vigor of the stored seeds at 5ºC and 20ºC.

OBJETIVO: Desenvolver um modelo preditivo capaz de identificar, ao final da primeira semana de vida, os recém-nascidos prematuros com maior probabilidade de evoluir para displasia broncopulmonar (DBP). MÉTODOS: Os dados foram coletados retrospectivamente entre janeiro de 1998 e julho de 2001, e prospectivamente de agosto de 2001 a julho de 2003. Foram incluídas todas as crianças nascidas na Instituição, com idade gestacional < 34 semanas e peso de nascimento < 1.500 g. Os principais fatores de risco foram submetidos inicialmente a uma análise univariada, seguida de regressão logística. As variáveis significativas foram utilizadas na montagem da fórmula para cálculo da probabilidade de ocorrência de DBP. O modelo foi calibrado, e a discriminação avaliada pela curva ROC. De agosto de 2003 a julho de 2005, o modelo foi aplicado em outra população para validação. RESULTADOS: Foram incluídas 247 crianças, das quais 68 evoluíram para DBP, sendo divididas da seguinte maneira: leve = 35 (51,4%), moderada = 20 (29,4%) e grave = oito (11,7 %). Quatro variáveis mantiveram significância em relação à DBP: idade gestacional < 30 semanas, persistência do canal arterial, ventilação mecânica > 2 dias e perda de > 15% do peso de nascimento no sétimo dia de vida. Nos pacientes com todas as variáveis presentes, o modelo permitiu uma probabilidade de acerto de 93,7%. Valores semelhantes foram obtidos com as 61 crianças utilizadas na validação do modelo. CONCLUSÕES O modelo preditivo desenvolvido em nossa população foi capaz de identificar com elevado grau de sensibilidade, ao final da primeira semana de vida, os recém-nascidos sob maior risco de evoluir para DBP.

OBJECTIVE: To develop a predictive model capable of identifying which premature infants have the greatest probability of presenting bronchopulmonary dysplasia (BPD), based on assessment at the end of their first week of life. METHODS: Data were collected retrospectively from January 1998 to July 2001, and prospectively from August 2001 to July 2003. All children born at the institution with gestational age < 34 weeks and birth weight < 1,500 g were included. The principal risk factors for BPD were subjected to univariate analysis followed by logistic regression. Significant variables were used to construct a formula to calculate the probability of BPD. The model was calibrated and its discriminative power assessed using receiver operating characteristic (ROC) curves. Between August 2003 and July 2005 the model was then applied to a different population for validation. RESULTS: The sample comprised 247 children, of whom 68 developed BPD, classified as follows: mild = 35 (51.4%), moderate = 20 (29.4%) and severe = 8 (11.7 %). Four variables maintained significance with relation to BPD: gestational age < 30 weeks, persistent ductus arteriosus, mechanical ventilation > 2 days and loss of > 15% of birth weight on the seventh day of life. Where patients exhibited all of these variables, the model had a 93.7% probability of being correct. The model was further validated when using another sample of 61 newborns; similar figures were obtained. CONCLUSIONS: At the end of the first week of life, the predictive model developed from our population was capable of identifying newborn infants at increased risk of developing BPD with a high degree of sensitivity.

Os efeitos da freqüência de rega e da umidade do solo na germinação carpogênica de Sclerotinia sclerotiorum foram estudados em condições ambientais controladas. Solo e escleródios foram acondicionados em caixas tipo gerbox e umedecidos uma, duas, três e cinco vezes por semana até os níveis de 75 e 100% da saturação. O solo regado uma vez por semana até 75% da saturação não permitiu a germinação dos escleródios, enquanto o solo molhado até 100% da saturação permitiu a germinação de até 70% dos escleródios, assim como um grande número de apotécios. Regas mais freqüentes, nos dois níveis de umidade do solo, aumentaram a germinação de escleródios e a produção de apotécios. Tão importante quanto a umidade do solo foi o intervalo entre regas, pois regas mais freqüentes, mesmo com volumes menores de água, favoreceram a maior germinação carpogênica do patógeno.

The effects of watering frequency and soil moisture status on the carpogenic germination of Sclerotinia sclerotiorum were studied under controlled environmental conditions. Soil and sclerotia were placed in gerbox and periodically watered up to 75 and 100% of saturation, one, two, three and five times a week. There was no sclerotium germination when the soil was watered up to 75% of saturation once a week. On the other hand, soils saturated frequently allowed higher percentage of sclerotia germination, until 70%, as well as higher numbers of apothecia. Independently of the soil water content, germination of sclerotia and production of apothecia increased with watering frequency. Important factors on the carpogenic germination of S. sclerotiorum were the soil moisture and the watering frequency. Frequent watering, even with low water volumes applied, also increased the carpogenic germination.

Este artigo tem como objetivo analisar os fatores que são identificados como atuantes para a ocorrência das situações de maus-tratos cometidos contra crianças, presentes nos três principais periódicos brasileiros de Pediatria. A produção bibliográfica foi tratada com base na análise de conteúdo. Considerando os critérios de inclusão dos artigos, foram analisados 14 trabalhos. Em termos de resultados, ressaltam-se como modelos teóricos explicativos: (a) a reprodução das experiências de violência; (b) os desajustes familiares, psíquicos e alcoolismo; (c) a ordem macro estrutural. Dentre as conclusões, destaca-se que as políticas de prevenção e intervenção dos maus-tratos cometidos contra a infância terão maior êxito se conseguirem articular uma compreensão teórico-prática. É preciso integrar a singularidade de cada caso ao conhecimento acumulado no atendimento a milhares de famílias envolvidas na prática de maus-tratos (no Brasil e no mundo).

This article analyzes the factors related to child abuse that have been published in three of the main Brazilian pediatrics journals. The literature was assessed by content analysis. Fourteen studies were analyzed. The main explanatory factors were: (a) reproduction of violence; (b) family and psychological disorders and alcohol abuse; and (c) the structural or macro-social order. The authors conclude that prevention or intervention policies can be more successful if a theoretical/practical understanding is achieved, and that it is necessary to integrate each unique case with the knowledge based on care for thousands of families involved in child abuse both in Brazil and worldwide.

Este artigo tem como objetivo analisar os fatores que são identificados como atuantes para a ocorrência das situações de maus-tratos cometidos contra crianças, presentes nos três principais periódicos brasileiros de Pediatria. A produção bibliográfica foi tratada com base na análise de conteúdo. Considerando os critérios de inclusão dos artigos, foram analisados 14 trabalhos. Em termos de resultados, ressaltam-se como modelos teóricos explicativos: (a) a reprodução das experiências de violência; (b) os desajustes familiares, psíquicos e alcoolismo; (c) a ordem macro estrutural. Dentre as conclusões, destaca-se que as políticas de prevenção e intervenção dos maus-tratos cometidos contra a infância terão maior êxito se conseguirem articular uma compreensão teórico-prática. É preciso integrar a singularidade de cada caso ao conhecimento acumulado no atendimento a milhares de famílias envolvidas na prática de maus-tratos (no Brasil e no mundo).

This article analyzes the factors related to child abuse that have been published in three of the main Brazilian pediatrics journals. The literature was assessed by content analysis. Fourteen studies were analyzed. The main explanatory factors were: (a) reproduction of violence; (b) family and psychological disorders and alcohol abuse; and (c) the structural or macro-social order. The authors conclude that prevention or intervention policies can be more successful if a theoretical/practical understanding is achieved, and that it is necessary to integrate each unique case with the knowledge based on care for thousands of families involved in child abuse both in Brazil and worldwide.