ABSTRACT Root biomass plays a vital role in nutrient cycling for the maintenance and functioning of different ecosystems. In this context, this study aimed to determine the stocks of elements in root biomass under different covers in the Cerrado of Tocantins, Brazil. The research was conducted in different vegetal coverings: agriculture, pasture, Eucalyptus sp., and native Cerrado forest. Root biomass was collected in six trenches, 70 x 70 cm, and a depth of 50 cm through sieving. Macro and microelement stocks were determined in root biomass. Macros and microelements showed higher average values for the native forest. With the change in vegetation cover, N, P, and S were higher in agriculture, with stocks of 1.82 Mg ha-1, 1.83 Mg ha-1, and 9.6 Mg ha-1. In a planted forest of Eucalyptus sp., macroelements K, Ca, and Mg were higher, with stock values of 16.06 Mg ha-1, 25.91 Mg ha-1, and 5.02 Mg ha-1, and microelements, B, Cu, Fe, Mn, and Zn with values of 0.05 Mg ha-1, 0.04 Mg ha-1, 5 Mg ha-1, 0.7 Mg ha-1, and 0.08 Mg ha-1 in root biomass, respectively. Thus, the planted forest of Eucalyptus sp. promoted greater stocks and cycling of elements, with greater stability of the organic material.

RESUMO As biomassas radiculares desempenham um papel importante na ciclagem de nutrientes, para manutenção e funcionamento dos diferentes ecossistemas. Diante desse contexto, o trabalho teve como objetivo determinar os estoques de elementos em biomassa radiculares sob diferentes coberturas no Cerrado em Tocantins, Brasil. A pesquisa foi conduzida em diferentes coberturas vegetais: agricultura, pastagem, Eucalyptus sp. e floresta nativa de cerrado. As biomassas radiculares foram coletadas em seis trincheiras com dimensões 70 x 70 cm, e profundidade de 50 cm através do peneiramento. Os estoques dos macros e microelementos foram determinados em biomassas radiculares. Os macros e microelementos apresentaram valores médios maiores para floresta nativa. Com a mudança de cobertura vegetal N, P, S, foram maiores em agricultura, com estoques de 1,82 Mg ha-1, 1,83 Mg ha-1 e 9,6 Mg ha-1. Em floresta plantada de Eucalyptus sp., os macroelementos K, Ca e Mg foram maiores tendo valores de estoques respectivamente de 16,06 Mg ha-1, 25,91 Mg ha-1 e 5,02 Mg ha-1 e microelementos B, Cu, Fe, Mn e Zn com valores de 0,05 Mg ha-1, 0,04 Mg ha-1, 5 Mg ha-1, 0,7 Mg ha-1 e 0,08 Mg ha-1 em biomassas radiculares. Deste modo a floresta plantada de Eucalyptus sp. promoveu maiores estoques e ciclagem de elementos, com maior estabilidade do material orgânico.

ABSTRACT. This study aimed to evaluate cassava genotypes to identify the ones with the best nutritional values for ruminant diets. Nine genotypes were used: Amansa Burro (BGM 549), Aramaris (BGM 116), Brasília, Cambadinha (BRS Guaíra), Curvelinha, Engana Ladrão (BGM 1269), Trouxinha (BGM 1468), BRS Gema de Ovo, and BRS Dourada. A completely randomized block experimental design with nine treatments (genotypes) and three blocks (replicates) were employed. The roots were analyzed for dry matter production (DMP) in tonnes per hectare, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), starch, and in vitro dry matter digestibility (IVDMD). The multivariate analysis was carried out using Ward’s hierarchical agglomerative clustering based on Mahalanobis distance. The groups formed were evaluated by Scott-Knott test. The group formed by genotype Engana Ladrão was chosen as the best one for having the highest DMP t ha-1 and IVDMD values and the lowest NDF and ADF contents.

Abstract Measurements of the marine carbonate system on tropical and subtropical continental margins are poorly distributed in space and time, with many uncertainties persisting regarding the role of carbon exchanges at the ocean-atmosphere interface in these areas. To calculate sea-to-air CO 2 fluxes in Marine Ecoregions along the Brazilian continental margin (4°N to 34°S), we used data from the Surface Ocean CO 2 Atlas (SOCAT v2020), collected up to 400 km from the coast, at the surface (5 m), between 1991 and 2018, with the aim of investigating the role of ecoregions as potential sinks or sources of atmospheric CO 2. The temperature and salinity of seawater presented variability in the north-south direction mainly because of the broad latitudinal range, reflecting typical patterns of tropical (T = 27.4°C ±1.49; S = 36.4 ±1.91) and subtropical waters (T = 22.8°C ±3.41; S = 35 ±2.91), in addition to the greater or lesser influence of river inputs in each ecoregion. The pCO 2 values in the surface waters varied from 121.81 (Amazon) to 478.92 μatm (Eastern), differing significantly between ecoregions and showing an expected decadal increasing trend, both in the atmosphere and in the seawater. The calculated values of CO 2 fluxes showed non-homogeneous spatio-temporal variations, from -24.37 mmol m-2 d-1 (Rio Grande) to 9.87 mmol m- 2 d-1 (Southeastern). Throughout the analyzed time series, we observed that the Northeast, Amazon and Eastern ecoregions acted predominantly as sources of CO 2 and the Southeastern ecoregions and, mainly, Rio Grande, acted predominantly as sinks of atmospheric CO 2.

Abstract The steady-state is a situation of little variability of species dominance and total biomass over time. Maintenance of cyanobacteria are often observed in tropical and eutrophic ecosystems and can cause imbalances in aquatic ecosystem. Bayeasian networks allow the construction of simpls models that summarizes a large amount of variables and can predict the probability of occurrence of a given event. Studies considering Bayeasian networks built from environmental data to predict the occurrence of steady-state in aquatic ecosystems are scarce. This study aims to propose a Bayeasian network model to assess the occurrence, composition and duration of cyanobacteria steady-state in a tropical and eutrophic ecosystem. It was hypothesized long lasting steady-state events, composed by filamentous cyanobacteria species and directly influenced by eutrophication and drought. Our model showed steady-state lasting between 3 and 17 weeks with the monodominance or co-dominance of filamentous species, mainly Raphidiopsis raciborskii and Planktothrix agardhii. These evens occurred frequently under drought and high turbidity, however higher nutrients concentrations did not increase the probability steady-state occurrence or longer duration. The proposed model appears as a tool to assess the effects of future warming on steady-state occurrence and it can be a useful to more traditional process-based models for reservoirs.

Abstract Intense soil preparation and disturbance in crops, over time, reduces the quantity and quality of soil organic matter. Given this context, this work aimed to determine soil carbon stocks and labile fractions under agroforestry system (AFS) and toposequences in an altitude marsh, Taquaritinga do Norte, Pernambuco, Brazil. The study was carried out at the Yaguara farm, and the areas studied were native forest with 4.57 ha and coffee plantation in shade with native forest with 25.59 ha. Soil samples were collected in four trenches measuring 1.5 x 1.5 x 0.60 m, with a distance of 50 meters. Soils were collected at depths of 0-20, 20-40 and 40-60 cm, followed by chemical, physical and density analyzes to determine soil carbon stocks and labile fractions. The area with shaded coffee showed higher values of soil carbon stocks at depths of 0-20 cm and 20-40 cm. At a depth of 40-60 cm, the AFS top toposequence showed the highest carbon stock with 11.73 Mg ha-1, followed by the area with native vegetation with 10.6 Mg ha-1, slope with 9.23 Mg ha-1 and pediment with 7.00 Mg ha-1. It was found that the top toposequence with shaded coffee exhibited a greater stock of labile carbon at depth 0-20 cm with a value of 1.06 Mg ha-1, followed by the bedding areas (SAF) with 0.88 Mg ha-1, native forest with 0.79 Mg ha-1 and slope with 0.67 g kg-1. However, the area of native vegetation showed the highest value of labile carbon at a depth of 40-60 cm. It was concluded that the area with shaded coffee in the top toposequence showed great capacity to increase total carbon stocks and labile carbon stocks of soil organic matter.

Resumo O intenso preparo e revolvimento do solo em cultivos, com o tempo, reduz a quantidade e a qualidade da matéria orgânica do solo. Diante desse contexto, este trabalho teve como objetivo determinar os estoques de carbono do solo e frações lábeis sob sistema agroflorestal (SAF) e topossequências em brejo de altitude, em Taquaritinga do Norte, Pernambuco, Brasil. O estudo foi desenvolvido na fazenda Yaguara, e as áreas estudadas foram mata nativa com 4,57 ha e plantio de café sombreado com mata nativa com 25,59 ha. As amostras de solos foram coletadas em quatro trincheiras 1,5 x 1,5 x 0,60 m, com distância de 50 metros. Foram coletados solos nas profundidades de 0-20, 20-40 e 40-60 cm, seguido de análises químicas, físicas e densidade para determinação dos estoques de carbono no solo e frações lábeis. A área com café sombreado apresentou maiores valores de estoques de carbono no solo nas profundidades de 0-20 cm e 20-40 cm. Na profundidade de 40-60 cm, a topossequência de topo do SAF apresentou maior estoque de carbono com 11,73 Mg ha-1, seguido da área com vegetação nativa com 10,6 Mg ha-1 , encosta com 9,23 Mg ha-1 e pedimento com 7,00 Mg ha-1. Verificou-se que a topossequência de topo com café sombreado exibiu maior estoque de carbono lábil na profundidade 0-20 cm com o valor de 1,06 Mg ha-1, sucedido das áreas de pedimento (SAF) com 0,88 Mg ha-1, mata nativa com 0,79 Mg ha-1e encosta com 0,67 Mg ha-1. No entanto, a área de vegetação nativa apresentou o maior valor de carbono lábil na profundidade de 40-60 cm. Concluiu-se que a área com café sombreado na topossequência topo mostrou grande capacidade para elevar os estoques de carbono total e estoques de carbono lábil da matéria orgânica do solo.

Sporothrix consists of the dimorphic genus of fungi, among the species, S. schenckii, S. mexicana, S. globosa and S. brasiliensis. It can be found in soil and decaying plant matter around the world, especially in tropical and subtropical regions. Infections produced by the fungus result from the traumatic inoculation of fungal filaments through the skin. There are increasing occurrences of contamination between humans and domestic animals in Brazil. The objective was to reflect on research at the postgraduate level carried out in Brazilian universities, optionally considering doctoral theses. State-of-the-art and bibliographic methodologies were used, considering the time frame from 2011 to 2020, in the databases, CAPES and BDBTD platforms. With the data, statistical analysis of ANOVA and geospatialization with the QGIS software were used. With the results, 18 and 31 theses were retrieved respectively from the platforms, analyzed from the perspective of the thematic axes, public health, infection and treatment, pharmacology and veterinary sciences. It can be concluded that there are records of the presence of the fungus in the country since the 80s, and the treatment of the disease depends on the therapy, it is a zoonosis and, therefore, a public health issue in some states by mandatory notification

O Sporothrix consiste no gênero de fungos tipo dimórfico, dentre as espécies, S. schenckii, S. mexicana, S. globosa e S. brasiliensis. Pode ser encontrado no solo e em matéria vegetal em vias de decomposição no mundo, sobretudo, regiões tropicais e subtropicais. Infecções produzidas pelo fungo resultam da inoculação traumática de filamentos fúngicos através da pele. Há crescentes ocorrências de contaminação entre humanos e animais domésticos no Brasil. Objetivou-se refletir sobre pesquisas ao nível de pós-graduação realizadas em universidades brasileiras, considerando opcionalmente teses de doutoramento. Utilizou-se das metodologias Estado da Arte e bibliográfica, considerando o recorte temporal de 2011 a 2020, nos bancos de dados, plataformas CAPES e BDBTD. Com os dados fez-se uso da análise estatística da ANOVA e geoespacialização com o software QGIS. Com os resultados foram recuperadas 18 e 31 teses respectivamente das plataformas, analisadas sob a perspectiva dos eixos temáticos, saúde pública, infecção e tratamento, farmacologia e ciências veterinárias. Pode-se concluir que há registros da presença do fungo no país desde os anos 80, bem como o tratamento da doença depende da terapêutica, trata-se de uma zoonose e, portanto, questão de saúde púbica em alguns estados por notificação obrigatória

Abstract An adequate amount of soil organic matter is considered essential for long-term sustainable agriculture, ensuring good productivity. Therefore, the present study quantified carbon and nitrogen stocks and microbiological activity in soil of three different areas: Forest-pasture System, Pasture System and preserved Caatinga - used as a reference of the experiment - located in a semi-arid region, in Watershed of Pajeú River, state of Pernambuco, Brazil. Eight trenches were opened in each system to collect soil samples at depths of 0 - 10, 20 - 30 and 50 - 60 cm, for chemical and microbiological analysis. In general, attributes of soil showed better results of land use in the following order: preserved Caatinga - Forest-pasture System - Pasture System.

Resumen La clasificación de la madera aserrada es una de las actividades más subjetivas de la fase final del proceso de aserrado de trozas en los aserríos. La presente investigación tuvo como objetivo proponer herramientas de auxilio en la clasificación de madera aserrada de coníferas. El estudio se realizó en el aserrío Combate de Tenerías de la Empresa Forestal Integral (EFI) Macurije, Pinar del Río, Cuba. Los datos utilizados proceden de 259 tablas de Pinus caribaea var. caribaea clasificadas siguiendo las exigencias (24 variables) y clases establecidas por el clasificador de madera aserrada de coníferas utilizado en Cuba. Se procedió al ajuste de un modelo de Regresión Logística Multinomial Ordinal (RLMO) y al entrenamiento de Redes Neuronales Artificiales (RNAs). Los parámetros del modelo RLMO fueron estimados usando el método de máxima verosimilitud optimizada con el algoritmo de Newton-Raphson. El entrenamiento de las RNAs se realizó con el algoritmo Broyden-Fletcher-Goldfarb-Shanno (BFGS). El problema de multicolinearidad, casi siempre presente en modelaciones con numerosas variables predictivas, fue abordado con el análisis factorial, utilizando los factores retenidos como entradas de los modelos. Con base en el porcentaje de aciertos en la clasificación, la RNA RBF 24-8-4 fue superior a las ecuaciones de regresión logística ordinal.

Abstract Lumber classification is one of the most subjective activities of the final phase of log sawing process in sawmills. The objective of this research was to propose tools that assist in conifers lumber grading. The research was carried out at the sawmill Combate de Tenerías of Macurije integrated forest company, Pinar del Río, Cuba. The data used comes from 259 lumber pieces of Pinus caribaea var. caribaea classified following the requirements (24 variables) and classes established by the conifers lumber grader used in Cuba. We proceeded to fit a Multinomial and Ordinal Logistic Regression (MOLR) model and train Artificial Neural Networks (ANNs). The parameters of the MOLR model were estimated using the maximum likelihood method optimized with the Newton Raphson algorithm. ANNs were trained with Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. The multicollinearity problem, usually present in modeling with numerous predictive variables, was addressed with factor analysis, using the factors retained as inputs to the models. Based on the percentage of correct classification, the ANN RBF 24-8-4 was superior to the ordinal logistic regression equations.

Resumo A atividade microbiana se mostra bastante sensível a mudanças da cobertura, tornando-se um importante indicador de qualidade do solo. O estudo teve como objetivo avaliar as alterações nas atividades microbiológicas do solo sob as diferentes coberturas vegetais no cerrado do Tocantins. O trabalho foi desenvolvido em áreas de Eucalyptus sp., pastagem, agricultura e cerrado sensu stricto na fazenda experimental da Universidade Federal do Tocantins. As amostras de solo foram coletadas em trincheiras de 70 x 70 cm nas profundidades 0-10 e 10-20 cm, com seis repetições. As variáveis avaliadas foram: concentração e estoque de carbono na biomassa microbiana, respiração basal do solo, quociente metabólico e quociente microbiano. A análise estatística foi realizada por meio do teste de normalidade, análise de variância e comparação das médias pelo teste Tukey a 5% de significância. A área com Eucalyptus sp. com 11 anos apresentou uma atividade microbiológica do solo estável, apresentando estoques de carbono na biomassa microbiana superiores em 57,32 % aos da vegetação de mata nativa, 84,29 % ao da pastagem e 290,91 % ao da agricultura. As atividades microbiológicas do solo são afetadas pela variação da cobertura vegetal do solo, sendo eficiente como indicador de qualidade do solo.

Abstract The microbial activity is very sensitive to changes in soil cover, making it an important indicator of soil quality. The study aimed to assess changes in soil microbiological activities under different vegetation coverings in the Cerrado biome of Tocantins state. The work was developed in areas of Eucalyptus sp., Pasture, agriculture and Cerrado sensu stricto in the experimental farm of the Federal University of Tocantins. The soil samples were collected in trenches of 70 x 70 cm at depths 0-10 and 10-20 cm, with six replications. The variables evaluated were: concentration and stock in the microbial biomass carbon, basal soil respiration, metabolic quotient and microbial quotient. The statistical analysis was performed using the normality test, analysis of variance and comparison of means by the Tukey test at 5% significance. The area with Eucalyptus sp. at 11 years of age, he had a stable soil microbiological activity, showing stocks in microbial biomass carbon 57.32% higher than that native forest vegetation, 84.29% that pasture and 290.91% that agriculture. The soil microbiological activities are affected by the variation of the soil vegetation cover, being efficient as an indicator of soil quality.

RESUMO A intensa antropização no baixo do rio São Francisco e áreas adjacentes geram risco de degradação ambiental e, sobretudo, torna essa área mais suscetível a processos erosivos. O objetivo do estudo identificar e correlacionar os atributos físicos e químicos que potencializam os processos erosivos e estabilidade dos taludes em margens de curso de água no baixo curso do Rio São Francisco, estado Sergipe, Brasil. As amostras de solos deformada e indeformadas foram coletadas na região do Baixo rio São Francisco, município de Amparo de São Francisco, Sergipe, em Neossolo Flúvico. Foram realizadas análises físicas (densidade, porosidade e textura) e químicas (pH, Capacidade de Troca de Cátions, saturação por bases, micro e macronutrientes no solo). Os camadas superficiais (Ap e AC) apresentaram superiores atributos físicos e maior teor de carbono orgânico que os demais camadas. O carbono orgânico, fosfóro e os micronutrientes obtiveram correlação negativa com a densidade do solo, onde um maior teor destes elementos nos camadas Ap e AC resultam em menor densidade do solo. As caracteristicas pedologicas das camadas do perfil avaliado não proporcionam uma resistência a erosão hidrica.

ABSTRACT The intense anthropization in the lower São Francisco River and surrounding areas can lead to environmental degradation risks and, above all, makes the area more susceptible to soil erosion. This study aimed to identify and correlate the physical and chemical properties able to enhance erosive processes and slope instability in the watercourse margins of the lower São Francisco River, in Sergipe State, Brazil. To this end, disturbed and undisturbed samples of an Entisol-Fluvent soil were collected in the region, specifically in the city of Amparo de São Francisco. Physical (density, porosity, and texture) and chemical (pH, cation exchange capacity, base saturation, micro-, and macronutrients) analyses were performed. All physical properties and organic carbon contents were higher in the surface layers (Ap and AC) compared to the others. Organic carbon, phosphorus, and micronutrients had a negative correlation with soil density, showing higher contents and lower soil densities in the Ap and AC layers. The pedological characteristics of the evaluated soil layers are unable to provide soil resistance to water erosion.

Abstract Soil organic matter has great importance in chemical, physical and biological processes in soil-plant system. This study aimed to evaluate changes in carbon humic fractions of soil organic matter under different vegetation coverings in Cerrado in Tocantins, Brazil. The work was developed in Eucalyptus sp., Pasture, Agriculture and Cerrado sensu stricto areas. Soil samples were collected in dry period, October, 2018, in trenches 70 x 70 cm at depths 0-10, 10-20, 20-30, 30-40 and 40-50 cm, with six replications. The vegetation cover in Eucalyptus sp. area showed higher levels of total carbon in soil humic fraction. Respectively fulvic acid, humic acid and humin in Eucalyptus sp. area had stocks of 22.09; 2.71 and 20.01% higher than native forest, 32.04; 2.57 and 35.59% higher than pasture and 10.59; 19.19 and 7.61% higher than the agriculture area. Among the different areas evaluated, the soil of Eucalyptus sp. has great potential to increase carbon storage in soil humic fractions.

RESUMO A erosão do solo é um dos maiores problemas em muitas partes do mundo com impactos diretos e indiretos representando um problema muito sério na agricultura e sustentabilidade ambiental, afetando a fertilidade e qualidade do solo. Elevada erosão do solo e altas cargas de sedimentos são problemas sérios em várias regiões semiáridas no Brasil. No intuito de aplicar procedimentos de mitigação, são necessários uma estimação precisa da erosão do solo e produção de sedimentos. Este trabalho visa a abordagem do Water Erosion Prediction Project (WEPP) na quantificação da erosão em sulcos e avaliação das relações físicas e hidráulicas, essenciais para investigar o desempenho do modelo. Com este objetivo, o experimento foi desenvolvido na região semiárida da bacia hidrográfica do Exu, Serra Talhada - Pernambuco (Brasil), através de aplicações crescentes de diferentes vazões: T1: 5,87 L min-1; T2: 12,10 L min-1; T3: 20,33 L min-1 e T4: 27,57 L min-1. Amostras de descargas líquidas e sólidas foram coletadas para determinação e caracterização dos parâmetros hidráulicos da vazão nos sulcos pré-estabelecidos. Os números de Reynolds entre 2.019 e 6.929 e de Froude abaixo de 1, atestaram a ocorrência de sulcos erosivos. As perdas de solo devido à erosão nos sulcos foram elevadas após os crescentes fluxos aplicados e o valor da erodibilidade do sulco obtido foi de 0,0011 kg N-1 s-1 e a tensão crítica de cisalhamento (tc) de 1,91 Pa causando o colapso das paredes laterais, elevação da área, perímetro molhado e o raio hidráulico dos sulcos experimentais.

ABSTRACT Soil erosion is a major environmental problem in many parts of the world and represents a serious problem for sustainable agriculture and the environment, with direct and indirect impacts on soil quality and fertility. This study aimed to use the Water Erosion Prediction Project (WEPP) model to estimate rill erosion and determine soil physical and hydraulic properties, which are essential to investigate its performance. To this end, an experiment was carried out in the Exu Creek watershed, in Serra Talhada, semi -arid region of Pernambuco State (Brazil), under increasing flow rates: T1: 5.87 L min-1; T2: 12.10 L min-1; T3: 20.33 L min1; and T4: 27.57 L min-1. Liquid and solid discharges were sampled for determination and characterization of hydraulic parameters in preformed rill flows. Reynolds numbers between 2,019 and 6,929 and Froude numbers below 1 found in this study attest to occurrence of erosive rills. Soil losses due to rill erosion increased as flow rates increased. Rill erodibility was 0.0011 kg N-1 s-1, and critical shear stress (tc) was 1.91 Pa, collapsing rill sidewalls and increasing local uplift, wet perimeter, and rill hydraulic radius.

Abstract This study aimed to assess soil chemical attributes, organic matter fractions and carbon stocks of forest in three different regeneration stages in the Serra de Itabaiana National Park, Sergipe. The study was conducted in three areas: open white sands, intermediate white sands, and closed white sands, with a history of differentiated degradation. Soil samples were collected at 0-20 cm depth for chemical characterization and for fractionation of soil organic matter and C stock. The open white sands obtained the best results regarding levels of macronutrients, total organic carbon, and total soil nitrogen, as well as higher carbon/nitrogen ratio compared with intermediate white sands and closed white sands, with such effects being attributed to recent exposure to fire. Carbon concentrations in humic fractions of organic matter were little influenced by different vegetation in regeneration, except the carbon fraction of humic acid, which is more sensitive to different management and soil usage.

Resumo A Reserva Biológica do Atol das Rocas situa-se no Oceano Atlântico, a 3º 51 'S e 33º 49' W, distante 143 milhas náuticas da cidade de Natal, estado do Rio Grande do Norte (Brasil). Este estudo teve como objetivo analisar a hidrologia, massas de água, correntes e o teor de clorofila a para determinar a dinâmica da biomassa fitoplanctônica em torno do Atol das Rocas. As amostras foram coletadas em julho de 2010 na área em torno do atol, usando o navio Oceanográfico da Marinha do Brasil, Cruzeiro do Sul. Dois transectos foram estabelecidos de acordo com a corrente superficial, um transecto em direção sudeste (SE) e o outro, em direção noroeste (NO) do Atol das Rocas. Nestes transectos foram determinados três pontos de coleta para cada um. As amostras foram coletadas em diferentes profundidades (superfície e PMC - Profundidade Máxima de Clorofila) e diferentes períodos do dia (dia e noite). De acordo com a ACP (Análise de Componentes Principais), observou-se que os nutrientes analisados, NID (nitrogênio inorgânico dissolvido), PID (fósforo inorgânico dissolvido) e silicato, correlacionaram-se inversamente com a temperatura e oxigênio dissolvido. A maioria das variáveis ambientais apresentou aumento significativo em função da turbulência no transecto noroeste. Pode-se observar que houve aumento dos teores de clorofila a e nutrientes, e redução da temperatura e oxigênio na camada de mistura em função da influência da ACAS (Água Central do Atlântico Sul). Apesar do aumento observado em algumas variáveis, como sais nutrientes e clorofila a, a temperatura na camada de mistura esteve com valor médio de 23,23 ºC, devido ao predomínio da Água Tropical. Portanto, o aumento de biomassa fitoplanctônica no transecto NW foi provocado pelo "efeito ilha" e não pela ressurgência.

Abstract The Rocas Atoll Biological Reserve is located in the Atlantic Ocean, at 3º 51' S and 33º 49' W. It lies 143 nautical miles from the City of Natal, Rio Grande do Norte (Brazil). The purpose of this study was to analyze the hydrology, water masses, currents and chlorophyll a content to determine the dynamics of phytoplankton biomass around the Rocas Atoll. Samples were collected in July 2010 in the area around the Atoll, using the Research Vessel Cruzeiro do Sul of the Brazilian Navy. Two transects were established according to the surface currents, one of which at the southeast of the Atoll (SE) and the other at norwest (NW). Three collection points were determined on each of these transects. Samples were collected at different depths (surface and DCM - Deep Chlorophyll Maximum) and different times (day and night). According to PCA (Principal Component Analysis), the nutrients analyzed, DIN (dissolved inorganic nitrogen), DIP (dissolved inorganic phosphorus) and silicate, were inversely correlated with temperature and dissolved oxygen. Most environmental variables showed a significant increase due to the turbulence on the Northwest transect. There was an increase in the concentration of chlorophyll a and nutrients when the temperature and oxygen in the mixed layer was reduced due to the influence of the SACW (South Atlantic Central Water). Despite the increase observed in some variables such as nutrient salts and chlorophyll a, the temperature in the mixed layer attained a mean value of 23.23 ºC due to the predominance of Tropical Water. The increase of the phytoplankton biomass on the NW transect was, therefore, caused by the "island effect" and not by upwelling.

INTRODUÇÃO: o sono é uma função biológica fundamental para a conservação da energia e a restauração do metabolismo energético.OBJETIVO: analisar o efeito de uma sessão do treinamento de força realizada em diferentes horários sobre a qualidade do sono de adolescentes e examinar se a relação entre a melhoria da qualidade do sono e o horário da sessão de treino se altera após o ajuste para idade.MÉTODOS: participaram do estudo seis estudantes do sexo masculino moradores internos do IFPE - Campus Vitória de Santo Antão, PE, Brasil. Foram realizadas três sessões de treinamento de força em diferentes horários manhã, tarde e noite, durante 12 semanas. A escala OMINI-RES foi utilizada para percepção do esforço. A qualidade do sono foi avaliada pelo Índice de Qualidade do Sono de Pittsburgh PSQI. Ainda foram avaliadas variáveis antropométricas massa corporal, estatura, IMC e a composição corporal % gordura, massa gorda e massa magra.RESULTADOS: foram observadas diferenças entre as sessões de treino realizadas em diferentes horários e a diagnose de qualidade do sono manhã: P < 0,001; tarde: P = 0,001; noite: P = 0,047. Houve correlação entre a sessão de treino realizada pela manhã r = 0,95 e à tarde r = 0,92 e a diagnose de qualidade do sono. Utilizando o modelo de regressão linear, as sessões de treinamento de força realizadas pela manhã R2= 0,91 e tarde R2= 0,75 explicaram de forma significativa a melhora da qualidade do sono em adolescentes, mesmo após o controle pela idade.CONCLUSÃO: as sessões de treinamento de força realizadas pela manhã e tarde apresentaram melhor resposta de qualidade do sono de adolescentes.

INTRODUCTION: sleep is a fundamental biological function for energy conservation and restoration of the energy metabolism.OBJECTIVE: To analyze the effect of a session of strength training performed at different times on the quality of sleep of adolescents and to examine the relationship between improving the quality of sleep and the time of the training session changes after adjusting for age.METHODS: participated in this investigation six male students internal residents of IFPE - Vitória de Santo Antão, PE, Brazil. Three strength training sessions were performed at different times morning, afternoon and evening for 12 weeks. The OMNI-RES scale was used to perceived exertion. Sleep quality was assessed using the Pittsburgh Sleep Quality Index PSQI. Anthropometric variables body weight, height, BMI and body composition %fat, fat mass and lean mass were evaluated.RESULTS: differences were observed between training sessions at different times and the diagnosis of sleep quality morning: P<0.001; afternoon: P=0.001; evening: P=0.047. There was a correlation between the training session held in the morning r=0.95 and in the afternoon r=0.92 and the diagnosis of sleep quality. Using the linear regression model, the strength training sessions held in the morning R2=0.91 and afternoon R2=0.75 explained the significantly improved quality of sleep in adolescents, even after adjusting for age.CONCLUSION: the strength training sessions in the morning and afternoon showed better response in the quality of sleep of adolescents.

INTRODUCCIÓN: el sueño es una función biológica básica en la conservación de la energía y la restauración del metabolismo energético.OBJETIVO: analizar el efecto de una sesión de entrenamiento de fuerza realizada en diferentes momentos en la calidad del sueño de los adolescentes y examinar si la relación entre la mejora de la calidad del sueño y el horario de la sesión de entrenamiento cambia después del ajuste para la edad.MÉTODOS: participaron del estudio seis estudiantes varones residentes internos de IFPE - Campus Vitória de Santo Antão, PE, Brasil. Tres sesiones de entrenamiento de fuerza se llevaron a cabo en diferentes momentos mañana, tarde y noche durante 12 semanas. La escala OMNI-RES se utilizó para el esfuerzo percibido. La calidad del sueño se evaluó mediante el Índice de Calidad del Sueño de Pittsburgh PSQI. Las variables antropométricas también fueron evaluadas peso, talla, índice de masa corporal y la composición corporal % de grasa, la masa grasa y la masa magra.RESULTADOS: se observaron diferencias entre las sesiones de entrenamiento realizadas en diferentes momentos y el diagnóstico de la calidad del sueño mañana: P < 0,001; tarde: P = 0,001; noche: P = 0,047. Hubo una correlación entre la sesión de entrenamiento realizada en la mañana r = 0,95 y la tarde r = 0,92 y el diagnóstico de la calidad del sueño. Usando el modelo de la regresión lineal las sesiones del entrenamiento de fuerza llevadas a cabo en la mañana R2 = 0,91 y R2 = 0,75 explicaron de modo significativo la mejora de la calidad del sueño en los adolescentes, incluso después del ajuste por edad.CONCLUSIÓN: las sesiones de entrenamiento de fuerza en la mañana y por la tarde tenían mejor respuesta de la calidad del sueño de adolescentes.