Landscape changes in Serra do Japi: legal protection or scientific expectation?

The creation of new legally protected areas brings many conflicts that distance the real landscape from the expected according to environmental law or conservation researchers. In this study, we mapped and compared the changes in Serra da Japi (Sao Paulo State, Brazil) throughout 40 years with scenarios of legal protection and scientific expectation on forest conservation, to evaluate the distance between them. This may allow us to infer the direction of historical changes and assist in the debate among decision makers. The results showed that most legal requirements on forest protection in the current landscape have been met. The 1960s was the period when the forest cover was closest to the desirable conservation stage. Although the Serra do Japi has maintained large areas of forests during the entire study period, human interference increased with the expansion of reforestation and urban areas, and access roads were identified as a primary potential driving forces of change. In addition, habitat loss was observed in the landscape, which can represent the first phase of a sequence of modifications detrimental to the environmental conservation of this protected area, including decision changes to land use. In conclusion, the changes evolved toward conservation expectations, but not toward the forest configuration of scientific expectation.

The influence of speech stimuli contrast in cortical auditory evoked potentials

Studies about cortical auditory evoked potentials using the speech stimuli in normal hearing individuals are important for understanding how the complexity of the stimulus influences the characteristics of the cortical potential generated. OBJECTIVE: To characterize the cortical auditory evoked potential and the P3 auditory cognitive potential with the vocalic and consonantal contrast stimuli in normally hearing individuals. METHOD: 31 individuals with no risk for hearing, neurologic and language alterations, in the age range between 7 and 30 years, participated in this study. The cortical auditory evoked potentials and the P3 auditory cognitive one were recorded in the Fz and Cz active channels using consonantal (/ba/-/da/) and vocalic (/i/-/a/) speech contrasts. Design: A crosssectional prospective cohort study. RESULTS: We found a statistically significant difference between the speech contrast used and the latencies of the N2 (p = 0.00) and P3 (p = 0.00) components, as well as between the active channel considered (Fz/Cz) and the P3 latency and amplitude values. These correlations did not occur for the exogenous components N1 and P2. CONCLUSION: The speech stimulus contrast, vocalic or consonantal, must be taken into account in the analysis of the cortical auditory evoked potential, N2 component, and auditory cognitive P3 potential.

Auditory processing in children and adolescents in situations of risk and vulnerability

CONTEXT AND OBJECTIVE: Children and adolescents who live in situations of social vulnerability present a series of health problems. Nonetheless, affirmations that sensory and cognitive abnormalities are present are a matter of controversy. The aim of this study was to investigate aspects to auditory processing, through applying the brainstem auditory evoked potential (BAEP) and behavioral auditory processing tests to children living on the streets, and comparison with a control group. DESIGN AND SETTING: Cross-sectional study in the Laboratory of Auditory Processing, School of Medicine, Universidade de São Paulo. METHODS: The auditory processing tests were applied to a group of 27 individuals, subdivided into 11 children (7 to 10 years old) and 16 adolescents (11 to 16 years old), of both sexes, in situations of social vulnerability, compared with an age-matched control group of 10 children and 11 adolescents without complaints. The BAEP test was also applied to investigate the integrity of the auditory pathway. RESULTS: For both children and adolescents, there were significant differences between the study and control groups in most of the tests applied, with significantly worse performance in the study group, except in the pediatric speech intelligibility test. Only one child had an abnormal result in the BAEP test. CONCLUSIONS: The results showed that the study group (children and adolescents) presented poor performance in the behavioral auditory processing tests, despite their unaltered auditory brainstem pathways, as shown by their normal results in the BAEP test.

Potencial evocado auditivo de média latência em crianças com dificuldades de aprendizagem

INTRODUÇÃO: Trata-se de uma semiologia laboratorial objetiva para avaliação do sistema auditivo de crianças com distúrbio de aprendizagem. OBJETIVO: Examinar os componentes do potencial evocado auditivo de média latência em uma amostra de crianças com distúrbio de aprendizagem e determinar suas propriedades. MÉTODO: O estudo realizado é do tipo prospectivo contemporâneo de corte transversal, quantitativo, descritivo e exploratório. 50 crianças de ambos os sexos com 8 a 14 anos de idade dividido em dois grupos iguais, com e sem distúrbio de aprendizagem. Causas orgânicas, ambientais ou genéticas foram excluídas do estudo. RESULTADOS E CONCLUSÃO: As ondas Na, Pa, Nb foram identificadas em todos os integrantes do estudo. Os valores de latência dos componentes foram Na= 19,2 ms, Pa= 32,5 ms, Nb= 46,4 ms (grupo controle) e Na= 19,7 ms, Pa= 35,1 ms, Nb= 49,6 ms (grupo pesquisa). O valor médio de amplitude Na-Pa foi 1,4 mV para ambos os grupos. As análises mostraram diferenças funcionais entre os grupos, foi observado o hemisfério esquerdo Nb latência mais longa de Nb no hemisfério esquerdo do grupo de estudo em relação ao controle. Tal estudo promoveu informações adicionais sobre PEAML e pode ser referência para outros estudos clínicos e experimentais nesta população.

Electrophysiological study of hearing in full-term small-for-gestational-age newborns

PURPOSE: To describe the Brainstem Auditory Evoked Potential (BAEP) results of full-term small-for-gestational-age newborns, comparing them to the results of full-term appropriate-for-gestational-age newborns, in order to verify whether the small-for-gestational-age condition is a risk indicator for retrocochlear hearing impairment. METHODS: This multicentric prospective cross-sectional study assessed 86 full-term newborns - 47 small- (Study Group) and 39 appropriate-for-gestational-age (Control Group - of both genders, with ages between 2 and 12 days. Newborns with presence of transient evoked otoacoustic emissions and type A tympanometry were included in the study. Quantitative analysis was based on the mean and standard deviation of the absolute latencies of waves I, III and V and interpeak intervals I-III, III-V and I-V, for each group. For qualitative analysis, the BAEP results were classified as normal or altered by analyzing these data considering the age range of the newborn at the time of testing. RESULTS: In the Study Group, nine of the 18 (38%) subjects with altered BAEP results had the condition of small-for-gestational-age as the only risk factor for hearing impairments. In the Control Group, seven (18%) had altered results. Female subjects from the Study Group tended to present more central alterations. In the Control Group, the male group tended to have more alterations. CONCLUSION: Full-term children born small or appropriate for gestational age might present transitory or permanent central hearing impairments, regardless of the presence of risk indicators.