Forest structure of artificial islands in the Tucuruí dam reservoir in northern Brazil: a test core-area model

Construction of hydroelectric dams in tropical regions has been contributing significantly to forest fragmentation. Alterations at edges of forest fragments impact plant communities that suffer increases in tree damage and dead, and decreases in seedling recruitment. This study aimed to test the core-area model in a fragmented landscape caused by construction of a hydroelectric power plant in the Brazilian Amazon. We studied variations in forest structure between the margin and interiors of 17 islands of 8-100 hectares in the Tucuruí dam reservoir, in two plots (30 and >100m from the margin) per island. Mean tree density, basal area, seedling density and forest cover did not significantly differ between marginal and interior island plots. Also, no significant differences were found in liana density, dead tree or damage for margin and interior plots. The peculiar topographic conditions associated with the matrix habitat and shapes of the island seem to extend edge effects to the islands' centers independently of the island size, giving the interior similar physical microclimatic conditions as at the edges. We propose a protocol for assessing the ecological impacts of edge effects in fragments of natural habitat surrounded by induced (artificial) edges. The protocol involves three steps: (1) identification of focal taxa of particular conservation or management interest, (2) measurement of an "edge function" that describes the response of these taxa to induced edges, and (3) use of a "Core-Area Model" to extrapolate edge function parameters to existing or novel situations.

Comparing different methods to measure biofilm thickness: the techniques are: optical coherence tomography, confocal laser scanning microscopy and low load compression test

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialização em Engenharia Clínica)

Alcohol Use Disorder Identification Test (AUDIT): explorando seus parâmetros psicométricos

OBJETIVO: O presente estudo teve como objetivo conhecer evidências de validade e precisão do Alcohol Use Disorder Identification Test (AUDIT). MÉTODOS: Contou-se com uma amostra de conveniência (não probabilística) de 547 estudantes universitários de Fortaleza (CE), com idade média de 21,6 anos (dp = 4,86; amplitude de 18 a 53), a maioria do sexo masculino (51,5%), solteira (91,4%) e católica (62,5%). Os participantes responderam ao AUDIT e a perguntas demográficas. Procurando conhecer a estrutura fatorial, além de estatísticas descritivas, realizou-se uma Análise de Componentes Principais. Adicionalmente, a fim de avaliar a precisão do instrumento, efetuaram-se cálculos de alfa de Cronbach (consistência interna), correlações de r de Pearson e coeficiente de correlação intraclasse - ICC (precisão teste-reteste). RESULTADOS: De acordo com a análise de componentes principais com rotação oblimin, a estrutura bifatorial do AUDIT mostrou-se coerente, com todos os itens apresentando saturações satisfatórias, superior a |0,40|, tendo o Fator 1 explicado 47,5% da variância total com alfa de 0,84 e o Fator 2 explicado 11,6% da variância total com alfa de 0,69. Os resultados do teste-reteste indicaram correlação forte entre os dados obtidos na primeira (t1) e segunda (t2) aplicação (r tt = 0,94, p < 0,01), sem diferença significativa de médias nos dois tempos (m t1 = 0,37, dp = 0,49; m t2 = 0,34, dp2= 0,47; p > 0,05), com ICC satisfatório (0,96). CONCLUSÕES: Os achados apoiaram a adequação psicométrica do AUDIT, com as análises fatoriais exploratórias apontando como mais satisfatória a estrutura com dois fatores, bem como atestaram sua boa estabilidade temporal.

Repeated assessment and practice effects of the written symbol digit modalities test using a short inter-test interval

The Symbol Digit Modalities Test (SDMT) is a widely used instrument to assess information processing speed, attention, visual scanning, and tracking. Considering that repeated evaluations are a common need in neuropsychological assessment routines, we explored test–retest reliability and practice effects of two alternate SDMT forms with a short inter-assessment interval. A total of 123 university students completed the written SDMT version in two different time points separated by a 150-min interval. Half of the participants accomplished the same form in both occasions, while the other half filled different forms. Overall, reasonable test–retest reliabilities were found (r = .70), and the subjects that completed the same form revealed significant practice effects (p < .001, dz = 1.61), which were almost non-existent in those filling different forms. These forms were found to be moderately reliable and to elicit a similar performance across participants, suggesting their utility in repeated cognitive assessments when brief inter-assessment intervals are required.

Faux Pas Test in schizophrenic patients

ABSTRACT Objective The aim of this study is to validate the adult version of “Faux Pas Recognition Test” created by Stone and colleagues (1998) as a reliable instrument assess and discriminate social cognition among schizophrenia patients and healthy controls. Methods This is a cross-sectional study with a total of 196 participants (mean age = 26.45; CI (95%) [25.10; 27.83]) 51% male. From those, 44 (22.4%) patients with schizophrenia and 152 (77.6%) healthy controls. The participants answered a short version of the Faux Pas Recognition Test, composed by 10 stories. Results Significant differences were found between both groups regarding their scores on Faux Pas Recognition Test (p = 0.003). Patients with schizophrenia had lower score, compared to healthy controls. Story 14 was the best to distinguish both groups, and Story 16, the worst. Among the questions of Faux Pas stories, the one related to intuition presented the most significant difference between the groups (p = 0.001), followed by the one related to understanding (p = 0.003). Conclusion The Brazilian version of the Faux Pas Recognition Test is a valid test to assess social cognition in schizophrenia and can be an important instrument to be used on the clinical practice.

Age effects on EEG correlates of the Wisconsin card sorting test

Body and brain undergo several changes with aging. One of the domains in which these changes are more remarkable relates with cognitive performance. In the present work, electroencephalogram (EEG) markers (power spectral density and spectral coherence) of age-related cognitive decline were sought whilst the subjects performed the Wisconsin Card Sorting Test (WCST). Considering the expected age-related cognitive deficits, WCST was applied to young, mid-age and elderly participants, and the theta and alpha frequency bands were analyzed. From the results herein presented, higher theta and alpha power were found to be associated with a good performance in the WCST of younger subjects. Additionally, higher theta and alpha coherence were also associated with good performance and were shown to decline with age and a decrease in alpha peak frequency seems to be associated with aging. Additionally, inter-hemispheric long-range coherences and parietal theta power were identified as age-independent EEG correlates of cognitive performance. In summary, these data reveals age-dependent as well as age-independent EEG correlates of cognitive performance that contribute to the understanding of brain aging and related cognitive deficits.

Fetal tachyarrhythmia with 1:1 atrioventricular conduction. Adenosine infusion in the umbilical vein as a diagnostic test

This is the report of a case of fetal tachyarrhythmia with 1:1 atrioventricular conduction detected by pre-natal echocardiography in a fetus at 25-weeks gestation. Adenosine infusion via cordocentesis was performed as a diagnostic test to differentiate between atrioventricular nodal reentrant supraventricular tachyarrhythmia and atrial flutter. After infusion, transient 2:1 atrioventricular dissociation was obtained and the diagnosis of atrial flutter was made. Transplacental therapy with digoxin and amiodarone was then successfully used.

Diagnostic value of the tilt-table test for the assessment of syncope in children and adolescents

OBJECTIVE - To assess the diagnostic value, the characteristics, and feasibility of tilt-table testing in children and adolescents. METHODS - From August 1991 to June 1997, we retrospectively assessed 94 patients under the age of 18 years who had a history of recurring syncope and presyncope of unknown origin and who were referred for tilt-table testing. These patients were divided into 2 groups: group I (children) - 36 patients with ages ranging from 3 to 12 (mean of 9.19±2.31) years; group II (adolescents) - 58 patients with ages ranging from 13 to 18 (mean of 16.05±1.40) years. We compared the positivity rate, the type of hemodynamic response, and the time period required for the test to become positive in the 2 groups. RESULTS - The positivity rates were 41.6 % and 50% for groups I and II, respectively. The pattern of positive hemodynamic response that predominated in both groups was the mixed response. The mean time period required for the test to become positive was shorter in group I (11.0±7.23 min) than in group II (18.44±7.83 min). No patient experienced technical difficulty or complications. CONCLUSION - No difference was observed in regard to feasibility, positivity rate, and pattern of positive response for the tilt-table test in children and adolescents. Pediatric patients had earlier positive responses.

The Portuguese version of the Psychological Adjustment to Separation Test-Part A (PAST-A): a study with recently and non-recently divorced adults

Past research has demonstrated that divorced adults show more health problems and psychological distress than married adults. Considering the high prevalence rates of divorce among Western countries, new and robust measures should be developed to measure psychological distress after this specific transition in adulthood. The aim of this study was to adapt and validate a Portuguese version of the Psychological Adjustment to Separation Test-Part A (PAST-A; Sweeper and Halford in J Family Psychol 20(4):632–640, 2006). PAST-A is a self-report measure that assesses two key dimensions of separation adjustment problems: lonely-negativity and former partner attachment. Psychometric properties of the Portuguese version of PAST-A were assessed in terms of factor structure, internal consistency, and convergent and divergent validity, in an online convenience sample with divorced adults (N = 460). The PAST-A two-factor structure was confirmed by exploratory and confirmatory factor analyses, with each factor demonstrating very satisfactory internal consistency and good convergence. In terms of discriminant validity, the Portuguese PAST-A reveals a distinct factor from psychological growth after divorce. The results provided support for the use of the Portuguese PAST-A with divorced adults and also suggested that the explicative factors of the psychological adjustment to divorce may be cross-cultural stable. The non-existence of validated divorce-related well-being measures and its implications for divorce research are also discussed.

Can the Cardiopulmonary 6-Minute Walk Test Reproduce the Usual Activities of Patients with Heart Failure?

OBJECTIVE: The 6-minute walk test is an way of assessing exercise capacity and predicting survival in heart failure. The 6-minute walk test was suggested to be similar to that of daily activities. We investigated the effect of motivation during the 6-minute walk test in heart failure. METHODS: We studied 12 males, age 45±12 years, ejection fraction 23±7%, and functional class III. Patients underwent the following tests: maximal cardiopulmonary exercise test on the treadmill (max), cardiopulmonary 6-minute walk test with the walking rhythm maintained between relatively easy and slightly tiring (levels 11 and 13 on the Borg scale) (6EB), and cardiopulmonary 6-minute walk test using the usual recommendations (6RU). The 6EB and 6RU tests were performed on a treadmill with zero inclination and control of the velocity by the patient. RESULTS: The values obtained in the max, 6EB, and 6RU tests were, respectively, as follows: O2 consumption (ml.kg-1.min-1) 15.4±1.8, 9.8±1.9 (60±10%), and 13.3±2.2 (90±10%); heart rate (bpm) 142±12, 110±13 (77±9%), and 126±11 (89±7%); distance walked (m) 733±147, 332±66, and 470±48; and respiratory exchange ratio (R) 1.13±0.06, 0.9±0.06, and 1.06±0.12. Significant differences were observed in the values of the variables cited between the max and 6EB tests, the max and 6RU tests, and the 6EB and 6RU tests (p<0.05). CONCLUSION: Patients, who undergo the cardiopulmonary 6-minute walk test and are motivated to walk as much as they possibly can, usually walk almost to their maximum capacity, which may not correspond to that of their daily activities. The use of the Borg scale during the cardiopulmonary 6-minute walk test seems to better correspond to the metabolic demand of the usual activities in this group of patients.

Creación de un test neuropsicológico de denominación confrontacional

La evaluación de la capacidad de denominar (encontrar las palabras adecuadas para nombrar objetos) tiene una importancia decisiva en el diagnóstico temprano de la enfermedad de Alzheimer ya que la anomia (pérdida de esta capacidad) es uno de los signos más tempranos de la enfermedad. Dicha evaluación también adquiere importancia en el diagnóstico de otras patologías tales como la demencia semántica o la afasia. Por lo tanto es importante contar con un test de denominación que sea adecuadamente diseñado para nuestro contexto cultural. Debido a que las pruebas de denominación creadas en otros contextos culturales no funcionan adecuadamente al aplicarse transculturalmente es que se comenzó, hace algunos años, a construir el Test de Denominación Córdoba. Éste es un test neuropsicológico para evaluar la capacidad de denominación confrontacional (implica la producción de los nombres correctos de figuras que se le presentan al individuo). Se diseñaron las láminas, y se realizó un estudio piloto para determinar el orden correcto de las mismas y eliminar láminas técnicamente inadecuadas. Luego se comenzaron los estudios de validez y la estandarización del test. En este proyecto se propone finalizar con los estudios de validez, confiabilidad y los baremos. Para ello se propone administrar alrededor de 200 tests a personas cognitivamente sanas para completar el baremo y alrededor de 20 a 25 personas con Enfermedad de Alzheimer para el estudio de validez

Desarrollo de un test de detección temprana de trastornos de aprendizaje- test de velocidad de denominación.

La evaluación de la velocidad de denominación permite la identificación temprana de niños en riesgo de desarrollar dislexia. Por lo tanto es importante contar con un test de velocidad de denominación que sea adecuadamente diseñado para nuestro contexto cultural. Debido a que las pruebas de denominación creadas en otros contextos culturales no funcionan adecuadamente al aplicarse transculturalmente, es que se propone construir el Test de Velocidad de Denominación. Éste es un test neuropsicológico para evaluar la velocidad de denominación (implica cronometrar el tiempo necesario para la producción de los nombres correctos de figuras que se le presentan al individuo). Se diseñarán las láminas y se realizará un estudio piloto para determinar las figuras más adecuadas a incluir. Luego se realizará un estudio de validez del test. Para completar ambos estudios se propone administrar alrededor de cincuenta tests a niños en edad pre-escolar (cuatro y cinco años) para el estudio de diseño de las láminas; y a alrededor de cien niños de primer a tercer grado se les administrará el Test de Velocidad de Denominación y dos subtests de la batería de lectura LEE, para el estudio de validez.