Brain Spectroscopy Analysis in Retired Soccer Players With Chronic Exposure to Mild Traumatic Brain Injuries.

Soccer players are at risk of suffering cranial injuries in the short and long term. There is growing concern that this may lead to traumatic brain injury in soccer players. Magnetic resonance spectroscopy (MRS) is an analytical method that enables the measurement of changes in brain metabolites that usually occur before significant structural changes. This study aimed to use MRS to compare variations in brain metabolite levels between retired soccer players and a control group. Twenty retired professional soccer players and 22 controls underwent magnetic resonance imaging, including MRS sequences and Mini-Mental State Examination (MMSE). Metabolite analysis was conducted based on absolute concentration and relative ratios. N-acetyl-aspartate, choline, glutamate, glutamine, and myoinositol were the metabolites of interest for the statistical analysis. Retired soccer players had an average age of 57.8 years, whereas the control group had an average age of 63.2 years. Median cognitive evaluation score, assessed using the MMSE, was 28 [26-29] for athletes and 29 [28-30] for controls (p = 0.01). Uni- and multi-variate analyses of the absolute concentration of metabolites (mM) between former athletes and controls did not yield any statistically significant results. Comparison of metabolites to creatine ratio concentrations did not yield any statistically significant results. There were no changes in concentrations of brain metabolites that indicated brain metabolic changes in retired soccer players compared with controls.

Association of gloves change and surgical site complications in elective cesarean sections of low-risk pregnancies.

BACKGROUND: The aim of this study was to assess whether the change of gloves is associated with reduced surgical site complications of elective cesarean sections in low-risk pregnancies. METHODS: A prospective and observational study was conducted, with 169 patients selected for elective cesarean sections, and divided into two groups: group 1 (N.=100) (no change of gloves); and group 2 (N.=94) (gloves changed during surgery). Fisher's Exact Test was used to test hypotheses and existence of associations between variables. The receiver operating characteristic curve (ROC) was used to determine the best value of surgical time to identify complications in the surgical site. RESULTS: There was significant effect on surgical time (group 1: 72.6 vs. group 2: 65.1 min, P=0.006). There was no association between changing gloves and the presence of complications of the surgical site. Approximately 22.5% of patients had at least one complication up to 60 days after cesarean section, with no association between the change of gloves and the presence of comorbidities during prenatal follow-up (P>0.999). Surgical time >70 min was able to correctly identify 59.1% of cases of surgical site complications up to 60 days after cesarean section with a false positive rate of 34% (area under ROC curve: 0.627, P=0.0126, 95% CI: 0.554-0.695). CONCLUSIONS: In low-risk patients submitted to elective cesarean sections, change of gloves did not reduce the incidence of complications of the surgical site. Surgical time was an independent predictor for the presence of complications of the surgical site up to 60 days after cesarean section.

Contributions to Dynamic Analysis of Differential Evolution Algorithms.

The Differential Evolution (DE) algorithm is one of the most successful evolutionary computation techniques. However, its structure is not trivially translatable in terms of mathematical transformations that describe its population dynamics. In this work, analytical expressions are developed for the probability of enhancement of individuals after each application of a mutation operator followed by a crossover operation, assuming a population distributed radially around the optimum for the sphere objective function, considering the DE/rand/1/bin and the DE/rand/1/exp algorithm versions. These expressions are validated by numerical experiments. Considering quadratic functions given by f(x)=xTDTDx and populations distributed according to the linear transformation D-1 of a radially distributed population, it is also shown that the expressions still hold in the cases when f(x) is separable (D is diagonal) and when D is any nonsingular matrix and the crossover rate is Cr=1.0. The expressions are employed for the analysis of DE population dynamics. The analysis is extended to more complex situations, reaching rather precise predictions of the effect of problem dimension and of the choice of algorithm parameters.

Quantifying protocols for safe school activities.

By the peak of COVID-19 restrictions on April 8, 2020, up to 1.5 billion students across 188 countries were affected by the suspension of physical attendance in schools. Schools were among the first services to reopen as vaccination campaigns advanced. With the emergence of new variants and infection waves, the question now is to find safe protocols for the continuation of school activities. We need to understand how reliable these protocols are under different levels of vaccination coverage, as many countries have a meager fraction of their population vaccinated, including Uganda where the coverage is about 8%. We investigate the impact of face-to-face classes under different protocols and quantify the surplus number of infected individuals in a city. Using the infection transmission when schools were closed as a baseline, we assess the impact of physical school attendance in classrooms with poor air circulation. We find that (i) resuming school activities with people only wearing low-quality masks leads to a near fivefold city-wide increase in the number of cases even if all staff is vaccinated, (ii) resuming activities with students wearing good-quality masks and staff wearing N95s leads to about a threefold increase, (iii) combining high-quality masks and active monitoring, activities may be carried out safely even with low vaccination coverage. These results highlight the effectiveness of good mask-wearing. Compared to ICU costs, high-quality masks are inexpensive and can help curb the spreading. Classes can be carried out safely, provided the correct set of measures are implemented.

Arteriopathy in pediatric stroke: an underestimated clinical entity.

BACKGROUND: Pediatric arterial ischemic stroke (AIS), which was thought to be a rare disorder, is being increasingly recognized as an important cause of neurological morbidity, thanks to new advances in neuroimaging. OBJECTIVE: The aim of this study was to review the main etiologies of stroke due to arteriopathy in children. METHODS: Using a series of cases from our institution, we addressed its epidemiological aspects, physiopathology, imaging findings from CT, MR angiography, MR conventional sequences and MR DWI, and nuclear medicine findings. RESULTS: Through discussion of the most recent classification for childhood AIS (Childhood AIS Standardized Classification and Diagnostic Evaluation, CASCADE), we propose a modified classification based on the anatomical site of disease, which includes vasculitis, varicella, arterial dissection, moyamoya, fibromuscular dysplasia, Takayasu's arteritis and genetic causes (such as ACTA-2 mutation, PHACE syndrome and ADA-2 deficiency). We have detailed each of these separately. Conclusions: Prompt recognition of AIS and thorough investigation for potential risk factors are crucial for a better outcome. In this scenario, neurovascular imaging plays an important role in diagnosing AIS and identifying children at high risk of recurrent stroke.

Imaging of brain tumors in children: the basics-a narrative review.

Primary pediatric brain tumors comprise a broad group of neoplasm subtypes that can be categorized based on their histological and molecular features according to the 2016 World Health Organization (WHO) classification of central nervous system (CNS) tumors. The majority of the pediatric brain tumors demonstrate a singular preference for this age group and have a unique molecular profile. The separation of certain tumor entities, including different types of embryonal tumors, low-grade gliomas, and high-grade gliomas, may have a significant impact by guiding appropriate treatment for these children and potentially changing their outcomes. Currently, the focus of the imaging diagnostic studies is to follow the molecular updates, searching for potential imaging patterns that translate this information in molecular profile results, therefore helping the final diagnosis. Due to the high impact of accurate diagnosis in this context, the scientific community has presented extensive research on imaging pediatric tumors in recent years. This article summarizes the key characteristics of the imaging features of the most common primary childhood brain tumors, categorizing them according to the recent WHO classification update, which is based on each of their molecular profiles. The purpose of this review article is to familiarize radiologists with their key imaging features and thereby improve diagnostic accuracy.

Arteriopathy in pediatric stroke: an underestimated clinical entity / Arteriopatia em crianças com acidente vascular cerebral: uma entidade clínica subestimada

ABSTRACT Background: Pediatric arterial ischemic stroke (AIS), which was thought to be a rare disorder, is being increasingly recognized as an important cause of neurological morbidity, thanks to new advances in neuroimaging. Objective: The aim of this study was to review the main etiologies of stroke due to arteriopathy in children. Methods: Using a series of cases from our institution, we addressed its epidemiological aspects, physiopathology, imaging findings from CT, MR angiography, MR conventional sequences and MR DWI, and nuclear medicine findings. Results: Through discussion of the most recent classification for childhood AIS (Childhood AIS Standardized Classification and Diagnostic Evaluation, CASCADE), we propose a modified classification based on the anatomical site of disease, which includes vasculitis, varicella, arterial dissection, moyamoya, fibromuscular dysplasia, Takayasu's arteritis and genetic causes (such as ACTA-2 mutation, PHACE syndrome and ADA-2 deficiency). We have detailed each of these separately. Conclusions: Prompt recognition of AIS and thorough investigation for potential risk factors are crucial for a better outcome. In this scenario, neurovascular imaging plays an important role in diagnosing AIS and identifying children at high risk of recurrent stroke.

RESUMO Introdução: O acidente vascular cerebral (AVC) pediátrico, considerado um distúrbio raro, está sendo cada vez mais reconhecido como importante causa de morbidade neurológica, graças aos novos avanços na neuroimagem. Objetivo: Revisar as principais etiologias do AVC por arteriopatia em crianças. Métodos: Utilizando-se de uma série de casos de nossa instituição, abordamos seus aspectos epidemiológicos, fisiopatológicos e de imagem na angiotomografia computadorizada e angiorressonância magnética, sequências convencionais e avançadas de ressonância magnética e medicina nuclear. Resultados: Com base na classificação mais recente de AVC na infância (Classificação Padronizada e Avaliação Diagnóstica do AVC na Infância - CASCADE) propusemos uma classificação modificada com base no local anatômico da doença, que inclui vasculite, varicela, dissecção arterial, Moyamoya, displasia fibromuscular, arterite de Takayasu e causas genéticas (como mutação ACTA-2, síndrome PHACE e deficiência de ADA-2), detalhando cada uma separadamente. Conclusões: O reconhecimento imediato do AVC na infância e a investigação minuciosa de possíveis fatores de risco são cruciais para um melhor resultado. Nesse cenário, a imagem neurovascular desempenha papel importante no diagnóstico de AVC e na identificação de crianças com alto risco de recorrência.

Hemorragia puerperal por inversão uterina: relato de caso / Puerperal hemorrhage after uterine inversion: a case report

A inversão uterina aguda no pós-parto é uma emergência obstétrica rara e potencialmente fatal, que ocorre nas primeiras 24 horas do puerpério e tem importante associação com hemorragia puerperal. Relata-se um caso de uma primípara de 19 anos, que após indução de parto devido a oligoâmnio, apresentou importante sangramento transvaginal, com instabilidade hemodinâmica. Teve seu reconhecimento e tratamento prontamente realizados, e assim não evoluiu com complicações. O reposicionamento é primeiramente tentado pela manobra de Taxe com uso de relaxantes uterinos, e caso falhe, opta-se por cirurgia. O prognóstico depende justamente da agilidade da intervenção terapêutica, que permite completa recuperação do quadro e ausência de sequelas.

Acute postpartum uterine inversion is a rare, potentially fatal obstetric emergency occurring within the first 24 hours of the puerperium, and which is closely associated with puerperal hemorrhage. In this case report, a 19-year-old primiparous woman had significant transvaginal bleeding, with hemodynamic instability, after induction of labor due to oligoamnios. The case was diagnosed and treated promptly, thus the patient evolved without complications. The standard treatment protocol usually comprises Taxe maneuver (manual uterine replacement) followed by uterine relaxants; only if it fails, surgery is performed. The prognosis depends precisely on prompt therapeutic intervention, which leads to complete recovery of the condition, as well as absence of sequelae.

Adult Leukodystrophies: A Step-by-Step Diagnostic Approach.

Leukodystrophies usually affect children, but in the last several decades, many instances of adult leukodystrophies have been reported in the medical literature. Because the clinical manifestation of these diseases can be nonspecific, MRI can help with establishing a diagnosis. A step-by-step approach to assist in the diagnosis of adult leukodystrophies is proposed in this article. The first step is to identify symmetric white matter involvement, which is more commonly observed in these patients. The next step is to fit the symmetric white matter involvement into one of the proposed patterns. However, a patient may present with more than one pattern of white matter involvement. Thus, the third step is to evaluate for five distinct characteristics-including enhancement, lesions with signal intensity similar to that of cerebrospinal fluid, susceptibility-weighted MRI signal intensity abnormalities, abnormal peaks at MR spectroscopy, and spinal cord involvement-to further narrow the differential diagnosis. ©RSNA, 2019.

Disease-specific quality of life after septoplasty and bilateral inferior turbinate outfracture in patients with nasal obstruction / Qualidade de vida específica da doença após septoplastia e fratura bilateral de concha inferior em pacientes com obstrução nasal

Abstract Introduction: Septal deviations might cause nasal obstruction and negative impact on the quality of life of individuals. The efficacy of septoplasty for treatment of septal deviation and the predictors of satisfactory surgical outcomes remain controversial. Technical variability, heterogeneity of research samples and absence of a solid tool for clinical evaluation are the main hindrances to the establishment of reliable statistical data regarding the procedure. Objective: To evaluate the clinical improvements in the disease-specific quality-of-life between patients submitted to septoplasty with bilateral outfracture of the inferior turbinate under sedation and local anesthesia in a tertiary hospital and to assess possible clinical-epidemiological variables associated with functional outcome. Methods: Fifty-two patients consecutively submitted to septoplasty with bilateral outfracture of the inferior turbinate for treatment of nasal obstruction filled in forms regarding clinical and epidemiological information during enrollment and had their symptom objectively quantified using the Nose Obstruction Symptom Evaluation (NOSE) scale preoperatively and one and three months after the procedure. Statistical analysis aimed to determine overall and stratified surgical outcomes and to investigate correlations between the clinical-epidemiological variables with the scores obtained. Results: Statistically significant improvement in the preoperative NOSE questionnaire compared to the scores obtained three months after surgery was demonstrated (p < 0.001, T-Wilcoxon), with strong correlation between the preoperative score and the postoperative improvement during this period (r = −0.614, p < 0.001, Spearman). After one month, patients reached in average 87.15% of the result obtained at the study termination. Smokers and patients with rhinitis and/or pulmonary comorbidity showed increased average preoperative NOSE scores, although without statistical significance (p > 0.05). Gender, age, history of rhinitis and presence of pulmonary comorbidity did not influence significantly surgical outcomes (p > 0.05). Smokers presented greater reduction in NOSE scores during the study (p = 0.043, U-Mann-Whitney). Conclusion: Septoplasty with bilateral outfracture of the inferior turbinate has proven to significantly improve disease-specific quality-of-life and this favorable outcome seems to occur precociously.

Resumo Introdução: Os desvios septais podem causar obstrução nasal e impacto negativo na qualidade de vida dos indivíduos. A eficácia da septoplastia para o tratamento do desvio septal e os preditores de resultados cirúrgicos satisfatórios continuam controversos. A variabilidade técnica, a heterogeneidade das amostras de estudo e a ausência de uma ferramenta sólida para avaliação clínica são os principais obstáculos ao estabelecimento de dados estatísticos confiáveis sobre o procedimento. Objetivo: Avaliar a melhora clínica na qualidade de vida específica da doença entre pacientes submetidos a septoplastia e fratura bilateral da concha inferior sob sedação e anestesia local em um hospital terciário e possíveis variáveis clínico-epidemiológicas associadas ao desfecho funcional. Método: Cinquenta e dois pacientes consecutivamente submetidos a septoplastia e fratura bilateral da concha inferior para o tratamento da obstrução nasal preencheram formulários com informações clínicas e epidemiológicas durante a inclusão no estudo e tiveram seus sintomas quantificados objetivamente utilizando a escala de Avaliação de Sintomas de Obstrução Nasal (Nose Obstruction Symptom Evaluation - NOSE) no pré-operatório e um e três meses após o procedimento. A análise estatística objetivou determinar resultados cirúrgicos globais e estratificados e investigar correlações entre as variáveis clínico-epidemiológicas e os escores obtidos. Resultados: Foi demonstrada uma melhora estatisticamente significativa nos escores obtidos no questionário NOSE três meses após a cirurgia (p < 0,001, T-Wilcoxon), quando comparado com os escores obtidos no pré-operatório, com uma forte correlação entre o escore pré-operatório e a melhora pós-operatória durante esse período (r = -0,614, p < 0,001, Spearman). Após um mês, os pacientes atingiram em média 87,15% do resultado obtido ao término do estudo. Fumantes e pacientes com rinite e/ou comorbidade pulmonar apresentaram valores médios pré-operatórios do escore NOSE aumentados, embora sem significância estatística (p > 0,05). Sexo, idade, história de rinite e presença de comorbidade pulmonar não influenciaram significativamente os resultados cirúrgicos (p > 0,05). Os fumantes apresentaram maior redução nos escores de NOSE (p = 0,043, U-Mann-Whitney). Conclusão: A septoplastia e a fratura bilateral da concha inferior demonstraram melhorar significativamente a qualidade de vida específica da doença e este resultado favorável parece ocorrer de forma precoce.

Prepartum supplementation of conjugated linoleic acids (CLA) increased milk energy output and decreased serum fatty acids and ß-hydroxybutyrate in early lactation dairy cows.

Prepartum supplementation with conjugated linoleic acid (CLA) may influence lipolysis and hyperketonemia in dairy cows. The objective of this study was to examine the effect of prepartum CLA supplementation on lactation performance and serum fatty acids (FA) and ß-hydroxybutyrate (BHB) in early lactation dairy cows, and secondarily on reproductive performance. Multiparous cows were enrolled in the study at 18 days prior to expected calving date, and randomly assigned 100 g/day of Lutrell Pure (BASF, Ludwigshafen, Germany; 75% FA), providing 10 g/day of each CLA isomer (trans-10 cis-12 and cis-9 trans-11 CLA) or equivalent amount of rumen inert fatty acids as control (78 g/day of Energy Booster 100; Milk Specialties Global, Eden Prairie, MN). Treatments were top dressed daily to individual cows from enrollment to calving and all cows were offered the same ration. Blood samples were collected on the first day of supplementation, 10 days prepartum, and 1, 7, 14, and 30 days postpartum. Hyperketonemia was defined as serum BHB ≥ 1.2 mM. Milk yield was recorded daily until 60 days postpartum and averaged weekly. Milk samples were obtained weekly for component analysis. Prepartum CLA supplementation tended to increase serum concentration of cis-9, trans-11 CLA and increased trans-10, cis-12 CLA prepartum. Cows supplemented with CLA had increased milk protein yield and tended to have increased milk fat yield and milk yield, which together resulted in greater energy content of milk. Cows supplemented with CLA had lower serum FA on day 1 and 7 postpartum and overall lower serum BHB postpartum, which resulted in decreased prevalence of hyperketonemia on day 14 postpartum. There were no differences in body condition score change, other health disorders, or reproductive outcomes by treatment. Together, these findings indicate that prepartum CLA supplementation may be a plausible strategy to positively influence postpartum performance.

Disease-specific quality of life after septoplasty and bilateral inferior turbinate outfracture in patients with nasal obstruction.

INTRODUCTION: Septal deviations might cause nasal obstruction and negative impact on the quality of life of individuals. The efficacy of septoplasty for treatment of septal deviation and the predictors of satisfactory surgical outcomes remain controversial. Technical variability, heterogeneity of research samples and absence of a solid tool for clinical evaluation are the main hindrances to the establishment of reliable statistical data regarding the procedure. OBJECTIVE: To evaluate the clinical improvements in the disease-specific quality-of-life between patients submitted to septoplasty with bilateral outfracture of the inferior turbinate under sedation and local anesthesia in a tertiary hospital and to assess possible clinical-epidemiological variables associated with functional outcome. METHODS: Fifty-two patients consecutively submitted to septoplasty with bilateral outfracture of the inferior turbinate for treatment of nasal obstruction filled in forms regarding clinical and epidemiological information during enrollment and had their symptom objectively quantified using the Nose Obstruction Symptom Evaluation (NOSE) scale preoperatively and one and three months after the procedure. Statistical analysis aimed to determine overall and stratified surgical outcomes and to investigate correlations between the clinical-epidemiological variables with the scores obtained. RESULTS: Statistically significant improvement in the preoperative NOSE questionnaire compared to the scores obtained three months after surgery was demonstrated (p<0.001, T-Wilcoxon), with strong correlation between the preoperative score and the postoperative improvement during this period (r=-0.614, p<0.001, Spearman). After one month, patients reached in average 87.15% of the result obtained at the study termination. Smokers and patients with rhinitis and/or pulmonary comorbidity showed increased average preoperative NOSE scores, although without statistical significance (p>0.05). Gender, age, history of rhinitis and presence of pulmonary comorbidity did not influence significantly surgical outcomes (p>0.05). Smokers presented greater reduction in NOSE scores during the study (p=0.043, U-Mann-Whitney). CONCLUSION: Septoplasty with bilateral outfracture of the inferior turbinate has proven to significantly improve disease-specific quality-of-life and this favorable outcome seems to occur precociously.

Low Ankle-Brachial Index is a Simple Physical Exam Sign Predicting Intracranial Atherosclerotic Stenosis in Ischemic Stroke Patients.

BACKGROUND: The investigation of ischemic stroke etiology is commonly limited to the heart and extracranial vessels. Nevertheless, the diagnosis of intracranial stenosis may carry important therapeutic implications. The aims of this study were to determine the prevalence and clinical predictors of intracranial atherosclerotic stenosis (ICAS) in a sample of patients with ischemic stroke. METHODS: Consecutive patients admitted to a university-based outpatient stroke clinic underwent CT angiography of the intracranial and extracranial brain vessels. Clinical, demographic, and laboratory characteristics were compared between patients with increasing levels of stenosis. Ankle-brachial index (ABI) was measured to quantify peripheral arterial disease, defined as an ABI less than or equal to .9. Multivariable ordinal logistic regression was constructed to predict increasing stenosis grades (none, 1%-49%-mild, 50%-69%-moderate, 70%-100%-severe). RESULTS: We studied 106 subjects, mean age 62 ± 15 years, 54% female. ICAS was present in 38 (36%) patients: 19 (50%) mild, 7 (18%) moderate, and 12 (32%) severe. Of 74 patients where ABI was measured, low ABI was found more frequently with increasing ICAS severity (26%, 42%, 67%, and 89% of patients with none, mild, moderate, and severe ICAS, respectively). In univariable analysis, higher age, presence of diabetes, abdominal obesity, and low ABI correlated with increasing stenosis grades. In multivariable analysis, only low ABI remained independently associated with increasing stenosis grades. CONCLUSIONS: The ABI is independently associated with increasing severity of ICAS, making it a potentially useful triaging tool for more invasive test selection.

Fish passage post-construction issues: analysis of distribution, attraction and passage efficiency metrics at the Baguari Dam fish ladder to approach the problem

Fish passages are considered the oldest management tool used to minimize the impact of blocking fish migratory routes by hydroelectric power plants. However, fish passages are being installed without specific criteria in Brazil, with severe consequences to the conservation of the local fish fauna. Therefore, basic data gathered for fish passages already constructed could contribute to define operational rules, in addition to offer subsidies to decision-making and design of future facilities. Thus, the fish ladder of Baguari Dam was evaluated regarding temporal distribution, attraction, and ascension of the local fish fauna. A total of 20 fish samples were conducted immediately downstream of the dam and inside the fish ladder, from January 2010 to June 2011. Seasonal variation in fish abundance and richness was registered below the dam and inside the passage, with higher number of migratory fish in the reproductive season (Kruskall-Wallis, p = 0.04 and p = 0.05). Furthermore, higher concentration of migratory allochthonous and non-migratory species was registered for the spill bay (Wilcoxon, p = 0.009 and p = 0.006) compared to the tailrace, where the fish ladder entrance is located. This result suggests low efficiency of the attraction system of the mechanism during the reproductive period. Once entering the fish ladder, migratory species apparently ascend the facility due to the similar distribution throughout different stretches. Generally, the results showed that an operational rule for the Baguari Dam fish ladder should consider running the facility only during the reproductive period, unless the objectives of the passage are well defined. The attraction system must be more precisely evaluated, using technologies such as radiotelemetry. Similarly, fish ascension also should be better analyzed to evaluate the time spent to ascend and its influence in the reproductive biology of the species using the ladder. Pit-tag system could be used to approach this analysis. It is expected that the discussion of these results would be useful for companies of the energy sector and for environmental agencies in Brazil, subsidizing decisions related to the management of fish passages already installed and to the construction of new facilities in the country.

As passagens ou sistemas de transposição de peixes são uma das ferramentas de manejo mais antigas utilizadas para minimizar o impacto do bloqueio de rota migratória de peixes pela implantação de barragens. Todavia, sua implantação tem sido realizada sem muito critério no Brasil, trazendo consequências muitas vezes graves à conservação da ictiofauna local. Por essa razão, dados básicos obtidos para as passagens de peixes em funcionamento podem contribuir para definição de sua regra operativa, além de subsidiar tomada de decisões e o design de futuros sistemas. Assim, a escada de peixes da UHE Baguari foi avaliada quanto à distribuição temporal, atração e subida da ictiofauna local. Foram realizadas 20 amostragens a jusante da barragem e no interior da escada de peixes entre janeiro de 2010 a junho de 2011. Observou-se variação sazonal na distribuição e riqueza de espécies de peixes a jusante da barragem e dentro da escada, sendo que as espécies migradoras foram registradas em maior abundância durante o período reprodutivo (Kruskall-Wallis, p = 0,04 e p = 0,05). Além disso, nesse mesmo período, maior concentração das espécies migradoras alóctones e não migradoras foi registrada para a bacia de dissipação da barragem (Wilcoxon, p = 0,009 e p = 0,006) quando comparado ao canal de fuga, local onde se encontra a entrada da escada. Isso sugere que a eficiência do sistema de atração do mecanismo não seja a esperada nesse período. Uma vez dentro da escada, aparentemente as espécies migradoras percorrem todo o mecanismo, distribuindo-se de forma similar ao longo de sua extensão. Em geral, os resultados obtidos demonstram que, aparentemente, a regra operativa da escada deva indicar seu funcionamento apenas no período reprodutivo, ao menos até que os objetivos da transposição de peixes na UHE Baguari sejam de fato definidos. Já o sistema de atração da escada deverá ser avaliado de forma mais precisa, utilizando-se tecnologias como radiotelemetria. Da mesma forma, a subida dos peixes pela escada deve ser melhor analisada para se avaliar o tempo gasto e a influência desse período sobre a biologia reprodutiva dos peixes. O sistema de Pit-tag pode ser utilizado para realizar essa análise. Espera-se que a discussão das informações obtidas no presente trabalho possa ser utilizada pelas empresas do setor elétrico e órgãos ambientais para subsidiar decisões relacionadas ao manejo de sistemas de transposição de peixes já em funcionamento e à construção de novos empreendimentos.