Resumo Anaplasma marginale é uma bactéria Gram-negativa intracelular obrigatória de eritrócitos de ruminantes e responsável pela anaplasmose bovina. A diversidade genética de A. marginale tem sido caracterizada com base nas sequências das principais proteínas de superfície (MSPs), como a MSP1α. O objetivo deste estudo foi investigar a diversidade genética de A. marginale em bovinos no estado do Maranhão, Nordeste do Brasil. Dessa forma, 343 amostras de sangue foram submetidas ao ensaio iELISA, utilizando-se a proteína recombinante MSP5. Das 343 amostras de sangue, 235 (68,5%) foram escolhidas aleatoriamente e submetidas à extração de DNA, qPCR e PCR convencional para gene msp1α, para determinação das sequências de aminoácidos e classificação dos genótipos. Os resultados do iELISA mostraram 81,34% de soropositividade (279/343), enquanto qPCR revelou 224 amostras positivas (95,32%). Dentre estas na qPCR, 67,4% (151/224) mostraram-se positivas no PCR convencional. Das 50 sequências obtidas, 21 cepas não haviam sido relatadas anteriormente. Em relação aos genótipos, H (26/50) e E (18/50) foram os mais frequentes, enquanto os genótipos F e C foram identificados apenas duas vezes cada, e B e G uma vez cada. Em conclusão, alta prevalência e marcante diversidade genética de A. marginale foram observadas em rebanhos leiteiros no estado do Maranhão.

Abstract Anaplasma marginale is an obligate intracellular Gram-negative bacterium found in ruminants’ erythrocytes and is the etiological agent of bovine anaplasmosis. The bacterium’s genetic diversity has been characterized based on sequences of major surface proteins (MSPs), such as MSP1α. The aim of the present study was to investigate the genetic diversity of A. marginale in cattle in the state of Maranhão, northeastern Brazil. To this end, 343 blood samples were harvested and subjected to iELISA assays using the recombinant surface protein MSP5. Out of 343 blood samples, 235 (68.5%) were randomly chosen and submitted to DNA extraction, qPCR and conventional PCR targeting the msp1α gene to determine amino acid sequences and classify the genotypes. The iELISA results showed 81.34% seropositivity (279/343), whereas qPCR revealed 224 positive samples (95.32%). Among these qPCR-positive samples, 67.4% (151/224) were also positive in the cPCR. Among the 50 obtained sequences, 21 strains had not been previously reported. Regarding the genotypes, H (26/50) and E (18/50) were identified most often, while genotypes F and C were only identified twice each and B and G once each. In conclusion, high prevalence and genetic diversity for A. marginale were observed in dairy cattle herds in the state of Maranhão.

RESUMO Objetivos Identificar como é a formação de profissionais da saúde quanto à Língua Brasileira de Sinais (Libras). Métodos Trata-se de estudo descritivo e transversal, desenvolvido com dados secundários, coletados no banco de dados eletrônico do Ministério da Educação. Foram analisados a grade curricular e o projeto pedagógico de todos os cursos de graduação na área da saúde em Instituições de Ensino Superior (IES) brasileiras, procurando-se identificar e caracterizar a disciplina de Libras. Resultados Foram localizados 5317 cursos e, destes, 2293 (43,1%) ofereciam disciplina de Libras, sendo 16,7% como disciplina obrigatória e a maioria (83,3%) como optativa. Em relação ao período ofertado, não houve um padrão, variando desde o primeiro até o décimo. Quanto à carga horária destinada à disciplina, dentre os 2077 cursos que disponibilizavam essa informação, 11,1% ofertavam a disciplina com carga horária de até 20 horas, 49,4% com carga horária entre 21 e 40 horas, 29,9% entre 41 e 60 horas, 9,1% entre 61 e 80 horas. Apenas 0,5% dos cursos destinavam mais que 80 horas para o ensino de Libras. Em média, os cursos de graduação em IES públicas (N=217) dedicavam 53,1 horas ao ensino de Libras, enquanto os cursos de IES privadas (N=1860) dedicavam 45,8 horas. Conclusão Há evidências de fragilidade na formação dos profissionais de saúde quanto ao ensino da Libras, o que reflete diretamente no atendimento integral dos surdos.

ABSTRACT Purpose To identify how Brazilian Sign Language (Libras) training is being conducted in undergraduate health care courses at Higher Education Institutions. Methods This is a descriptive and cross-sectional study, developed using secondary data taken from the Ministry of Education electronic database. The curriculum and pedagogical design of all undergraduate health care courses at Brazilian Higher Education Institutions (HEIs) were analyzed, aiming to identify and characterize the Libras discipline. Results 5317 courses were found and, from these, 2293 (43.1%) offered Libras, 16.7% as mandatory and the majority (83.3%) as optional. Regarding the period offered, there was no pattern, ranging from the first to the tenth. Regarding the workload for the discipline, among the 2077 courses that provided this information, 11.1% offered the discipline with a workload of up to 20 hours, 49.4% with a workload between 21 and 40 hours, 29.9% between 41 and 60 hours, and 9.1% between 61 and 80 hours. Only 0.5% of the courses devoted more than 80 hours to teaching Libras. On average, undergraduate courses in public HEIs (N = 217) devoted 53.1 hours to teaching Libras, while private HEI courses (N = 1860) dedicated 45.8 hours. Conclusion There is evidence of weakness in training programs for health professionals regarding teaching Libras, which directly reflects in comprehensive care for the deaf.

Due to the increase of bacterial resistance, the search for new antibiotics is necessary and the medicinal plants represent its most important source. The aim of this study was to evaluate the antibacterial property of extract and fractions from Protium spruceanum leaves, against pathogenic bacteria. By means of diffusion and microdilution assays, the crude extract was active against the nine bacteria tested being the hydromethanolic fraction the most active. During phytochemical procedures, procyanidin (1) and catechin (2) were identified as the main antibacterial constituents of this fraction. In silico results obtained using PASSonline tool indicated 1 and 2 as having good potential to interact with different targets of currently used antibiotics. These results no indicated potential to none DNA effect and indicated the cell wall as mainly target. Electrophoresis result supported that had no DNA damage. Cell wall damage was confirmed by propidium iodide test that showed increased membrane permeability and by cell surface deformations observed in scanning electronic microscopy. The in vitro assays together with the in silico prediction results establish the potential of P. spruceanum as source of antibacterial compounds that acts on important bacterial targets. These results contribute to the development of natural substances against pathogenic bacteria and to discovery of new antibiotics.

Abstract: We evaluated the antifungal and antibiofilm potential of the hydroalcoholic extract of bark from Anadenanthera colubrina (vell.) Brenan, known as Angico, against Candida spp. Antifungal activity was evaluated using the microdilution technique through the Minimum Inhibitory and Fungicide Concentrations (MIC and MFC). The antibiofilm potential was tested in mature biofilms formed by Candida species and analyzed through the counting of CFU/mL and scanning electron micrograph (SEM). In vivo toxicity and therapeutic action was evaluated in the Galleria mellonella model. The treatment with the extract, in low doses, was able to reduce the growth of planktonic cells of Candida species. MIC values range between 19.5 and 39 µg/mL and MFC values range between 79 and 625 µg/mL. In addition was able to reduce the number of CFU/mL in biofilms and to cause structural alteration and cellular destruction, observed via SEM. A. colubrina showed low toxicity in the in vivo assay, having not affected the viability of the larvae at doses below 100mg/kg and high potential in the treatment of C. albicans infection. Considering its high antifungal potential, its low toxicity and potential to treatment of infections in in vivo model, A. colubrina extract is a strong candidate for development of a new agent for the treatment of oral candidiasis.

Objetivo : Analisar a relevância da mensuração objetiva de rítides nasogenianas de mulheres em diferentes faixas etárias, utilizando-se osoftware radiocef 2.0® como ferramenta complementar na avaliação do cronoenvelhecimento facial. Método: Trata-se de um estudo observacional descritivo envolvendo 100 voluntárias do sexo feminino, com idade entre 20 e 70 anos, dispostas em cinco grupos de 20 voluntárias de acordo com a faixa etária. Os instrumentos utilizados foram o Protocolo de Avaliação Facial, o cefalostato para padronização das fotos, câmera digital e o software radiocef 2.0®. Foi aplicado o teste Kolmogorov-Smirnov para a confirmação da normalidade e todos os dados foram submetidos à análise estatística, usando o teste ANOVA e post hoc de Tukey. Foi realizado o teste Qui-quadrado e a correlação de Pearson. Foi adotado um nível de significância de 5% (p≤0,05). Resultados : Foi observado que todas as faixas etárias apresentaram rugas na localização do sulco nasogeniano. Observou-se também uma associação entre a idade e as escalas de Goglau e Lapiere e Pierard. Essa incidência surgiu progressivamente com o aumento da faixa etária. Foi verificada correlação moderada (r=0,67) entre a idade e a distância do sulco nasogeniano, enquanto o seu ângulo diminui com correlação fraca (r=0,3), sendo mais significativa a faixa etária que obteve a menor distância e o maior ângulo. Conclusão: O estudo demonstrou relevância do software radiocef 2.0®. para a análise mais detalhada do sulco nasogeniano, surgindo assim como uma complementação da avaliação, podendo se tornar um protocolo de investigação para identificar a eficácia dos tratamentos realizados, otimizando o método avaliativo.

Objective : To evaluate the facial aging of women of different ages using a software program to assist in the classification of wrinkles and sagging in the nasogenian region. Method : A descriptive observational study of 100 female volunteers was performed. The women were aged between 20 and 70 years old and were sorted by age group into five groups of 20 volunteers each. The instruments used were the Facial Assessment Protocol, a cephalostat for the standardization of photos, a 14.1 megapixel Sony digital camera, and the Radiocef 2.0® software program. The Kolmogorov-Smirnov (KS) test was used for confirmation of normality and all data was statistically analyzed using ANOVA and Tukey's post hoc analysis. The Chi-squared and Pearson's correlation tests were also performed. A significance level of 5% and a p value of ≤0.05 were adopted. Results : It was observed that all age groups had wrinkles in the nasolabial fold region. There was an association between age and the Goglau, Lapiere and Pierard scale. This incidence increased progressively with aging. A moderate correlation (r=0.67) was observed between age and distance from the nasolabial folds, while angle represented only a weak correlation (r=0.3), with the most significant age group that with the shortest distance and the widest angle. Conclusion : The present study demonstrated the importance of the Radiocef 2.0® software program in providing a more detailed analysis of the nasolabial folds. It is therefore a complementary assessment to the Facial Assessment Protocol, representing a research protocol for identifying the effectiveness of treatments and improving the evaluative procedure.

PURPOSE:To characterize bone marrow progenitors cells grown in vitro,using native goats from northeastern Brazil as animal model.METHODS:Ten northeastern Brazil native goats of both genders were used from the Piauí Federal University Agricultural Science Center's (UFPI) - Goat Farming Sector. Bone marrow aspirates where taken from the tibial ridge and seeded on culture plates for isolation, expansion and Flow Cytometry (expression markers - Oct-3/4, PCNA, Ck-Pan, Vimentina, Nanog).RESULTS:Progenitor cells showed colonies characterized by the presence of cell pellets with fibroblastoid morphology. Cell confluence was taken after 14 days culture and the non-adherent mononuclear cell progressive reduction. After the first passage, 94.36% cell viability was observed, starting from 4.6 x 106 cell/mL initially seeded. Cells that went through flow cytometry showed positive expression for Oct-3/4, PCNA, Ck-Pan, Vimentina, and Nanog.CONCLUSIONS:Bone marrow progenitor isolated of native goats from northeastern Brazil showed expression markers also seen in embryonic stem cells (Oct-3/4, Nanog), markers of cell proliferation (PCNA) and markers for mesenchymal cells (Vimentina and Ck-pan), which associated to morphological and culture growth features, suggest the existence of a mesenchymal stem cell (MSC) population in the goat bone marrow stromal cells studied.

This experiment was carried out with the objectives of determining repeatability coefficients, the number of harvests necessary to increase accuracy and the genotypic stability of yield characteristics in Brachiaria brizantha cultivars in the northeast region of Brazil in the period from July 2009 to March 2011. The experimental design used was completely randomized with three treatments (Brachiaria brizantha var. Marandu, Xaraés and Piatã) and three replications. Each plot was harvested seven times: five in the rainy season and two in the dry season. Immediately after each harvest, the forage was weighed and dried to obtain total, stem, leaf and dead dry matter yields. For the estimation of the repeatability coefficient, analysis of variance, principal components (correlation and covariance matrices) and structural analyses were used. The repeatability coefficients (r) obtained by the different methods, for all characteristics evaluated, varied from 0.009 to 0.837. The estimates of the repeatability coefficients obtained for all characteristics evaluated by the method of analyses of variance were almost always lower than those obtained by the other methods. By the principal components method (based on the covariance matrix), the estimates were always higher than those from other methods. Considering that levels of 80 or 90% confidence are satisfactory in the evaluation of the relative superiority of the cultivars for all the evaluated characteristics, with the exception of dead matter yield, the seven harvests are sufficient for the choice of the best cultivar to be used in the northeast region of Brazil.

Leprosy transmission still occurs despite the availability of highly effective treatment. The next step towards successfully eliminating leprosy is interrupting the chain of transmission of the aetiological agent, Mycobacterium leprae. In this investigation, we provide evidence that household contacts (HHCs) of leprosy patients might not only have subclinical infections, but may also be actively involved in bacilli transmission. We studied 444 patients and 1,352 contacts using anti-phenolic glycolipid-I (PGL-I) serology and quantitative polymerase chain reaction (qPCR) to test for M. leprae DNA in nasal swabs. We classified the patients according to the clinical form of their disease and the contacts according to the characteristics of their index case. Overall, 63.3% and 34.2% of patients tested positive by ELISA and PCR, respectively. For HHCs, 13.3% had a positive ELISA test result and 4.7% had a positive PCR test result. The presence of circulating anti-PGL-I among healthy contacts (with or without a positive PCR test result from nasal swabs) was considered to indicate a subclinical infection. DNA detected in nasal swabs also indicates the presence of bacilli at the site of transmission and bacterial entrance. We suggest that the concomitant use of both assays may allow us to detect subclinical infection in HHCs and to identify possible bacilli carriers who may transmit and disseminate disease in endemic regions. Chemoprophylaxis of these contacts is suggested.

O experimento foi realizado com o objetivo de avaliar os efeitos da forma de aplicação de fósforo, da amostragem do solo e do espaçamento entre linhas de plantio sobre os níveis críticos de fósforo no solo e na planta para o estabelecimento de capim-elefante (Pennisetum purpureum Schum.) cv. Napier. Os tratamentos foram distribuídos em três blocos ao acaso e consistiram de cinco níveis de fósforo (0; 1; 2; 3,3 e 5, correspondentes às doses de 0, 30, 60, 100 e 150 kg/ha de P, na aplicação localizada no fundo do sulco e a 0, 60, 120, 200 e 300 kg/ha de P, na aplicação distribuída no sulco), duas formas de aplicação (localizada e distribuída no sulco) e dois espaçamentos entre linhas de plantio (0,5 e 1,0 m). Os teores de fósforo foram quantificados nas amostras de solo retiradas à profundidade de 0 a 20 cm sobre as linhas de plantas recém-colhidas e entre as linhas de plantio. Nas amostras de forragem colhidas em dois cortes, foram determinadas as concentrações de fósforo e a produção de matéria seca. A produção de matéria seca no maior espaçamento foi bastante inferior à do espaçamento de 0,5 m entre linhas de plantio. No maior espaçamento, maiores níveis críticos foram observados, tanto no solo quanto na planta. O fósforo aplicado localizadamente resultou em maiores valores de nível crítico no solo, enquanto, na parte aérea das plantas, verificou-se o inverso. Os níveis críticos de fósforo na parte aérea diminuíram do primeiro para o segundo corte, independentemente da forma de aplicação, enquanto no solo esse efeito só ocorreu quando o fósforo foi aplicado de forma localizada.

This experiment was carried out to evaluate the forms of phosphorus application, soil sampling and row spacing on critical levels of phosphorus in the soil and shoot for the establishment of elephant grass cv. Napier. The treatments were arranged in three randomized blocks and consisted of five phosphorus levels (0, 1, 2, 3.3 and 5) corresponding, respectively, to 0, 30, 60, 100 and 150 kg/ha P for application on the bottom of the furrow and to 0, 60, 120, 200 and 300 kg/ha P thoroughly mixed in the furrow, two types of application (localized and distributed in the furrow) and two spacings (0.5 and 1.0 m). The phosphorus content were quantified in soil samples removed at 0-20 cm depth on the rows of the newly cut rows and between the planted rows. In the forage samples harvested in two cuttings, the phosphorus concentration and dry matter production were determined. Dry matter yield in the wider spacing was considerably lower than in the 0.5 m spacing between plating rows. In the wider spacing, greater critical levels were observed in both the soil and the plants. The phosphorus applied in the furrow resulted in greater values of the critical level in the soil, while the opposite was observed in the shoots. Critical phosphorus levels in the shoot of the plants decreased from the first to the second cutting, regardless of the application, whereas in the soil this occurred only when phosphorus was applied on the bottom of the furrow.

Avaliaram-se a demografia de perfilhos, a composição morfológica do pasto, o índice de área foliar (IAF), a taxa de acúmulo de massa seca de forragem (TAcMS) e os teores de proteína bruta, fibra em detergente neutro e lignina e os coeficientes de digestibilidade in vitro da massa seca de Brachiaria decumbens cv. Basilisk submetido a adubação nitrogenada (75, 150, 225 e 300 kg/ha.ano de N), em lotação contínua com taxa de lotação variável em dois anos agrícolas consecutivos. O delineamento foi em blocos casualizados, com duas repetições. No primeiro ano, a demografia de perfilhos vivos não foi alterada pelos meses de avaliação, mas, no segundo ano, foi maior nos meses de março e abril. A adubação nitrogenada promoveu resposta linear positiva na demografia de perfilhos vivos, no índice de área foliar e na taxa de acúmulo de massa seca. Maiores proporções de lâminas foliares foram constatadas em março do primeiro ano e em dezembro e janeiro do segundo ano, entretanto, as proporções de colmos no pasto não diferiram entre os meses de avaliação nos dois anos. Também foram observadas respostas lineares positivas dos teores de PB às doses de nitrogênio aplicadas em todos os meses nos dois anos. Os teores de FDN e lignina do capim-braquiária são influenciados pelos meses de avaliação e variam entre anos.

The objective of this study was to evaluate tiller demography, pasture morphological composition, leaf area index, dry matter herbage accumulation, dry matter in vitro digestibility and crude protein, neutral detergent fiber (NDF) and lignin contents of Brachiaria decumbens cv. Basilisk (Signalgrass), under nitrogen fertilization (75, 150, 225, 300 kg/ha.year of N) and continuous stock management with variable stocking rates, for two consecutive years. A randomized complete block design was used with two replications. In the first year, tiller demography did not differ, but in the second year it was increased in March and April. Nitrogen fertilization promoted a linear effect on tiller demography, leaf area index and dry matter accumulation. The percentage of leaf blades increased in March of the first year and in December/January of the second year, but stem percentage did not differ among the evaluated months in the two years. Positive linear response to the crude protein levels was observed as a result of applying nitrogen rates throughout the entire experiment. In both years, levels of NDF and lignin were not altered during the evaluation months.

OBJETIVO: Testar a hipótese de que colecistectomias agulhascópicas oferecem resultados superiores aos da colecistectomia laparoscópica usual (CL). MÉTODOS: Sessenta pacientes consecutivos com colecistopatia submetidos à CA ou CV foram avaliados quanto ao tempo operatório, freqüência de acidentes peroperatórios, dor pós-operatória, sintomas pós-operatórios tardios, comprimento das cicatrizes e grau de satisfação. RESULTADOS: O tempo operatório médio foi semelhante em ambos os grupos. A maioria dos pacientes, independentemente da técnica, relataram dor pós-operatória leve. Aqueles operados por CA tiveram menores níveis de dor no 7º dia de pós-operatório (PO7) (p<0.01) e menor necessidade de analgesia adicional. Menor freqüência de dor epigástrica foi observada no grupo CA até o PO4 (p<0.01). O resultado estético foi amplamente superior após CA (comprimento total das cicatrizes menor que a metade após CL). Não houve diferença quanto ao grau de satisfação entre os grupos. CONCLUSÕES: As duas técnicas foram seguras e eficazes, apresentando tempos operatórios semelhantes e baixos níveis de dor pós-operatória. A redução dos portais para 2-3 mm associou-se a menor freqüência de dor pós-operatória apenas na incisão epigástrica até o PO4. O resultado estético da agulhascopia foi significantemente superior ao da laparoscopia, apesar desta vantagem não ter influenciado o grau de satisfação dos doentes.

PURPOSE: To test the hypothesis that needlescopic cholecystectomies (NC) offer superior outcomes in comparison to common laparoscopic cholecystectomies (LC). METHODS: Sixty consecutive patients with gallbladder disease undergoing either LC or NC were evaluated with respect to differences in operative time, frequency of per-operative incidents, post-operative pain, late postoperative symptoms, length of scars and level of postoperative satisfaction. RESULTS: Mean operative time was similar in both groups. Most of the patients, irrespective of the technique, informed mild postoperative pain. NC patients had lower levels of pain on the 7th postoperative day (PO7) (p<0.01) and decreased need for additional analgesia. Less frequency of epigastric wound pain was observed in NC patients until PO4 (p<0.01). Aesthetic result was far superior after NC (total length of scars less than half after LC). No differences regarding postoperative satisfaction with the operation were observed between the studied groups. CONCLUSIONS: Both techniques were safe and effective, presenting similar operative times and low levels of postoperative pain. Downsizing the ports to 2-3 mm was associated with significantly less frequency of postoperative pain only in the epigastric wound until PO4. Aesthetic outcome of NC was significantly superior to LC, although this advantage did not influence patient level of satisfaction.

O trabalho foi realizado com o objetivo de avaliar as características morfogênicas de Panicum maximum x Panicum infestum cv. Massai submetido a quatro doses de nitrogênio (0, 40, 80 e 120 mg/dm³) e três regimes de desfolhação (três, quatro e cinco folhas completamente expandidas), em um esquema fatorial 4 x 3, em um delineamento inteiramente casualizado, com quatro repetições. Após semeadura, transplantio e desbaste, três plantas permaneceram em vasos com capacidade para 5,8 dm³ de solo. As adubações fosfatada e potássica foram realizadas de acordo com os resultados da análise do solo. A adubação nitrogenada, via solução aquosa, de acordo com os tratamentos experimentais, foi parcelada em quatro vezes. Quando as plantas apresentavam o número de folhas expandidas indicador da desfolhação, foram colhidas e avaliadas quanto às características morfogênicas. Ao findar o período experimental, as plantas foram colhidas e levadas à estufa, para determinação do teor de MS. A taxa de alongamento foliar (TAlF) aumentou linearmente até 64% na dose de 120 mg/dm³ de N, em comparação à ausência de nitrogênio. O filocrono reduziu com a adubação nitrogenada. A produção de MS da parte aérea do capim-massai e a relação lâmina:colmo aumentaram linearmente com as doses de N e a redução do número de folhas expandidas antes da colheita.

This work was carried out to evaluate the morphogenetic and structural characteristics of the hybrid Panicum maximum x Panicum infestum cv. Massai in response to four nitrogen doses (0, 40, 80 and 120 mg/dm³) and three defoliation intervals (two, three and four completely expanded leaves), in a 4 x 3 factorial treatment combination. The experiment was carried out in greenhouse according to a completely randomized design, with four replications. Sowing was achieved in plastic tray filled with sand and seedlings were transplanted to pots with 5.8 dm³ of soil. Pots were thinned to three plants/pot. The phosphate and potash fertilization was accomplished according to soil fertility analysis. The nitrogen fertilization was split in four applications in aqueous solution, according to the experimental doses. As the plants presented the number of expanded leaves, indicating their defoliation interval, they were harvested to 5 cm from soil level; this harvest marked the beginning of the evaluation period of the morphogenetic and structural characteristics of the grass. At the end of these evaluations, the plants were harvested, dried and weighted. Nitrogen fertilization doses had marked effects on the morphogenetic and structural characteristics of Massaigrass, as well as on its shoot dry weight. Leaf elongation rate (TAlF) showed linear increase of 64% to N doses. The phyllochron decreased as nitrogen dose increased. Shoot dry matter weight and lamina:stem ratio increased linearly with the increment of N doses but decreased as the number of expanded leaves increased before harvest.

Em um ensaio de pastejo sob lotação contínua avaliaram-se as taxas de aparecimento, mortalidade e sobrevivência, a porcentagem de florescimento e a densidade populacional de perfilhos basilares em uma pastagem de Brachiaria decumbens adubada com quatro doses de nitrogênio (75, 150, 225 e 300 kg/ha.ano). Os resultados foram agrupados em três períodos do ano: fevereiro a abril, maio a agosto e setembro a novembro. O experimento foi conduzido em parcelas subdivididas no tempo segundo delineamento em blocos completos casualizados, com duas repetições. A adubação nitrogenada foi parcelada em três aplicações: a primeira no mês de dezembro de 2002, a segunda em janeiro de 2003 e a terceira em março de 2003. A avaliação demográfica foi realizada em perfilhos demarcados por um anel de PVC. A partir da população inicial, a cada mês os perfilhos foram identificados utilizando-se arames de cores diferenciadas. Para avaliação da densidade populacional de perfilhos basilares (vegetativos, reprodutivos e mortos), foram colhidas amostras de plantas delimitadas por três quadrados de 25 x 25 cm por piquete. A adubação nitrogenada influenciou as taxas de aparecimento e sobrevivência, o número de perfilhos vegetativos e a mortalidade de perfilhos na primeira e segunda gerações após o início das avaliações. As maiores taxas de aparecimento ocorreram nos períodos de fevereiro/abril e setembro/novembro, enquanto a maior taxa de mortalidade, em fevereiro/abril. A densidade populacional de perfilhos também variou, atingido os maiores valores no período de fevereiro/abril. O florescimento do capim-braquiária se concentrou nos meses de fevereiro a maio.

It was evaluated tiller appearance, mortality and survival rates, the flowering percentage and the population density of basal tillers in pasture of Brachiaria decumbens under four doses of nitrogen (75, 150, 225 and 300 kg/ha/year), in three periods of the year: February to April, May to August and September to November. The experiment was conducted in a completely randomized design with periods as a split plot feature, with two replications. The nitrogen fertilization was split in three applications the first in December (2002), second in January (2003) and the third in March (2003). The evaluation of demography of basal tillers was accomplished by initial demarcation of all the tillers contained within a ring of PVC, followed by monthly identification of new tillers with wires of different colors. Evaluation of the population density of basal tillers (vegetative, reproductive and dead tillers) was performed from samples of plants harvested within 25 x 25 cm three squares from each paddock. The nitrogen fertilization positively influenced the tiller appearance, mortality and survival rates, number of vegetative tillers and the tillers mortality in the generations 1 and 2. Rates of tiller appearance were higher in February/April and September/November, while the rate of tiller mortality was higher in February/April period. Tiller population density also varied over the periods, higher figures being observed in Febrary/April period. The flowering of the Signalgrass flowering was most intense from February to May.

O trabalho foi realizado com o objetivo de se avaliarem as características morfogênicas e estruturais de Brachiaria brizantha cv. Xaraés, submetido a quatro doses de nitrogênio (0, 40, 80 e 120 mg/dm³) e três regimes de desfolhação (três, quatro e cinco folhas completamente expandidas), em um esquema fatorial 4 x 3. O experimento foi conduzido em casa de vegetação, com os tratamentos dispostos em um delineamento inteiramente casualizado, com quatro repetições. Após desbaste, foram mantidas três plantas por vaso com capacidade de 5,8 dm³. As plantas receberam adubação fosfatada e potássica, de acordo com análise de fertilidade do solo. A adubação nitrogenada, via solução aquosa, foi parcelada em quatro aplicações. Quando apresentaram número de folhas expandidas indicador de corte, as plantas foram colhidas a 5 cm do solo, iniciando-se as avaliações das características morfogênicas e estruturais. Os resultados indicaram que o nitrogênio tem efeito sobre as características morfogênicas e estruturais e sobre a produção de MS, com exceção da MS radicular. Observou-se incremento de até 37% na taxa de alongamento (cm/dia) para a mais elevada dose de N (120 mg/dm³ ) em relação ao tratamento sem adubação nitrogenada. A freqüência de corte influenciou a taxa de alongamento foliar, o filocrono, o comprimento final da lâmina, o número de folhas vivas por perfilhos, a taxa de senescência e o teor matéria seca da parte aérea e raiz.

The morphogenetic and structural traits of Brachiaria brizantha cv. Xaraés submitted to the treatment combinations of four nitrogen rates (0, 40, 80 and 120 mg/dm3) and three defoliation frequencies (two, four and five completely expanded leaves) were evaluated according to a 4 x 3 factorial arrangement. The experiments were conducted in a greenhouse, with the treatments arranged as factorial combination. The experimental design was completely randomized, with four replications. After thinning, three seedlings were left per pot (5,8 dm3). The phosphate fertilization was performed according to the soil fertility. The pots were fertilized with phosphorus and potassium, according to soil fertility. Nitrogen fertilization was split in four applications and applied in aqueous solution. When the plants reached the number of expanded leaves (defoliation moment), they were cut at 5 cm height from soil level before evaluation of morphogenetic and structural traits in the aftermath. Significant nitrogen effect was observed on morphogenetic and structural characteristics of xaraésgrass and on DM yield, except on root DM. Leaf elongation rate (LER) increased linearly up to 37% at the N rate of 120 mg/dm³. Defoliation influenced leaf elongation rate, phyllochron, blade length, number of live leaves per tiller, senescence rate and dry matter yield of shoot and root.