Ricardo Halpern

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Many children are at risk of not achieving their full potential for development. Epidemiological studies have the advantage of being able to identify a number of associated factors potentially amenable to intervention. Our purpose was to identify risk factors for suspected developmental delay (SDD) at age 2 years among all children born in the city of(More)
  • R Halpern
  • 1990
The relationship between poverty and child rearing has been a persistent source of social concern in the United States. Drawing on available literature, this paper seeks to establish a conceptual approach to the interaction of these two complex variables. Appropriate interventions and strategies for their implementation are considered.
This study assessed the sensitivity, specificity and predictive value of hearing complaints in outpatients attending an university ear, nose and throat clinic. A cross-sectional study was carried out in Canoas, Southern Brazil, from 1999 to 2002. Seven-hundred and ninety-five subjects who underwent the audiometric test were analyzed. The results showed that(More)
BACKGROUND Due to the mechanism of action of the dopamine transporter (DAT) in drug addiction, the DAT1 gene is a potential candidate for molecular studies. This paper aims to compare the prevalence of allele and genotype frequencies created by the 3' UTR variable number of tandem repeats (VNTR) of this gene between crack cocaine users and controls. (More)
BACKGROUND Child health has improved in many developing countries, bringing new challenges, including realization of the children's full physical and intellectual potential. This study explored child development within a birth cohort, its psychosocial determinants and interactions with maternal schooling and economic position. METHODS All children born in(More)
Acoustic analysis of infants crying, a sensitive and selective index for measuring the effect of pre and perinatal lead exposure, may provide an early marker for central nervous system damage produced by the toxic. The present study evaluated the effects of exposure to low lead levels during perinatal and early postnatal periods on ultrasonic vocalization(More)
OBJECTIVE To determine the prevalence of bullying (victims and perpetrators) in a representative sample of sixth graders from schools located in the city of Caxias do Sul, RS, Brazil and to determine possible associations with maternal education, socioeconomic level, sedentary habits, nutritional status, dissatisfaction with body image, gender, and age. (More)
OBJECTIVES To describe the main aspects of attention deficit/hyperactivity disorder, including history, epidemiology, etiology, neurobiology, clinical features, comorbidities, diagnosis, outcome and treatment. SOURCES OF DATA Comprehensive, non-systematic review of the literature on attention deficit/hyperactivity disorder. SUMMARY OF THE FINDINGS(More)
OBJECTIVE To investigate the relationship between socioeconomic factors, maternal characteristics, breastfeeding, and hospitalization for bronchiolitis in the post-neonatal period. METHODS A nested case-control study with a cohort of 5,304 children born in the city of Pelotas, Brazil, was conducted. The cohort study consisted of four sub-studies with(More)
OBJECTIVE To measure the main risk factors associated with the occurrence of accidental injuries in children aged 4-5 years. METHODS The study included a prospective cohort of children whose parents filled in a diary recording accidents and injuries during a period of one-month. The children represented a systematic subsample from a population-based birth(More)