utjecaj sezonskih promjena tropske klime na reprodukcijske pokazatelje i hormonski status jaraca sanske pasmine

This study evaluated the effects different seasons (rainy, rainy-dry transition, dry, dry-rainy transition) throughout the year on the reproduction and endocrine profile of Saanen bucks reared in a tropical climate. During these seasons environmental data were recorded (ambient temperature and relative air humidity) to calculate the temperature and humidity index. Reproductive parameters were also evaluated in the same periods to check seasonal variations, wherey semen was collected twice a month from nine Saanen bucks using an artificial vagina. Furthermore, scrotal circumference, scrotal surface temperature and serum levels of testosterone, triiodothyronine (T3), thyroxine (T4) and cortisol were measured. The climate parameters influenced the reproductive parameters, mainly during the dry period, when higher values of ambient temperature reduced sperm quality, however, scrotal circumference and surface temperature, as well as serum levels of testosterone increased. In conclusion, Saanen bucks reared in a tropical climate are subject to heat stress, evinced by transient seasonal variations in reproductive parameters, where the first season is the most favorable to reproduction.U ovom je radu istražen utjecaj različitih sezona (kišna, prijelaz iz kišne u suhu, suha, prijelaz iz suhe u kišnu) tijekom godine na reprodukcijski i endokrini status jaraca sanske pasmine uzgojenih u tropskoj klimi. Zabilježeni su podaci iz okoliša (temperatura i relativna vlažnost zraka) za vrijeme različitih sezona kako bi se izračunao indeks topline. Za ista su razdoblja procijenjeni reprodukcijski pokazatelji kako bi se istražile njihove sezonske varijacije u koju je svrhu od 9 jaraca sanske pasmine primjenom umjetne vagine, prikupljano sjeme dva puta mjesečno. Osim toga mjereni su obujam skrotuma, temperatura površine skrotuma te razina testosterona, trijodotironina (T3), tiroksina (T4) i kortizola u serumu. Klimatski uvjeti su utjecali na reprodukcijske pokazatelje, najviše za vrijeme suhog razdoblja, kad veće vrijednosti temperature okoliša smanjuju kvalitetu sjemena jaraca. Obujam i temperatura površine skrotuma, kao i serumska razina testosterona, u navedenoj sezoni su povećani. Zaključeno je da su sanski jarci uzgojeni u tropskoj klimi pod utjecajem toplinskog stresa, što se vidi iz sezonskih varijacija njihovih reprodukcijskih pokazatelja, pri čemu je kišna sezona najpovoljnija za reprodukciju

CD8+ T-Cells Expressing Interferon Gamma or Perforin Play Antagonistic Roles in Heart Injury in Experimental Trypanosoma Cruzi-Elicited Cardiomyopathy

In Chagas disease, CD8+ T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8+ T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC). Here we explored the role of CD8+ T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8+ T-cell capacity to produce interferon-gamma (IFNγ) and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8+ T-cells segregated into IFNγ+ perforin (Pfn)neg or IFNγnegPfn+ cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8+Pfn+ cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8−/− recipients showed that the CD8+ cells from infected ifnγ−/−pfn+/+ donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8+ cells from ifnγ+/+pfn−/− donors. Moreover, the reconstitution of naïve cd8−/− mice with CD8+ cells from naïve ifnγ+/+pfn−/− donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ+ cells accumulation, whereas reconstitution with CD8+ cells from naïve ifnγ−/−pfn+/+ donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn+ cells in the cardiac tissue. Our data support a possible antagonist effect of CD8+Pfn+ and CD8+IFNγ+ cells during CCC. CD8+IFNγ+ cells may exert a beneficial role, whereas CD8+Pfn+ may play a detrimental role in T. cruzi-elicited heart injury

Spatio-Temporal Tracking and Phylodynamics of an Urban Dengue 3 Outbreak in São Paulo, Brazil

The dengue virus has a single-stranded positive-sense RNA genome of ∼10.700 nucleotides with a single open reading frame that encodes three structural (C, prM, and E) and seven nonstructural (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) proteins. It possesses four antigenically distinct serotypes (DENV 1–4). Many phylogenetic studies address particularities of the different serotypes using convenience samples that are not conducive to a spatio-temporal analysis in a single urban setting. We describe the pattern of spread of distinct lineages of DENV-3 circulating in São José do Rio Preto, Brazil, during 2006. Blood samples from patients presenting dengue-like symptoms were collected for DENV testing. We performed M-N-PCR using primers based on NS5 for virus detection and identification. The fragments were purified from PCR mixtures and sequenced. The positive dengue cases were geo-coded. To type the sequenced samples, 52 reference sequences were aligned. The dataset generated was used for iterative phylogenetic reconstruction with the maximum likelihood criterion. The best demographic model, the rate of growth, rate of evolutionary change, and Time to Most Recent Common Ancestor (TMRCA) were estimated. The basic reproductive rate during the epidemics was estimated. We obtained sequences from 82 patients among 174 blood samples. We were able to geo-code 46 sequences. The alignment generated a 399-nucleotide-long dataset with 134 taxa. The phylogenetic analysis indicated that all samples were of DENV-3 and related to strains circulating on the isle of Martinique in 2000–2001. Sixty DENV-3 from São José do Rio Preto formed a monophyletic group (lineage 1), closely related to the remaining 22 isolates (lineage 2). We assumed that these lineages appeared before 2006 in different occasions. By transforming the inferred exponential growth rates into the basic reproductive rate, we obtained values for lineage 1 of R0 = 1.53 and values for lineage 2 of R0 = 1.13. Under the exponential model, TMRCA of lineage 1 dated 1 year and lineage 2 dated 3.4 years before the last sampling. The possibility of inferring the spatio-temporal dynamics from genetic data has been generally little explored, and it may shed light on DENV circulation. The use of both geographic and temporally structured phylogenetic data provided a detailed view on the spread of at least two dengue viral strains in a populated urban area

Development and reproductive performance of Hereford heifers of different frame sizes up to mating at 14-15 months of age

ABSTRACT Body development and reproductive performance of a hundred forty-two 14 to 15-month-old heifers, classified at weaning according to frame size as small, medium, and large, were evaluated. The parameters evaluated were: body weight, hip height, body condition score, weight gain, ovarian activity, and pregnancy rate. At weaning, body weight and hip height were significantly different among frame scores, (small – 133.0 kg, 92.2 cm; medium – 158.5 kg, 96.6 cm; and large – 185.2 kg; 100.2 cm). After weaning, heifers grazed together on natural pastures during the autumn and on ryegrass (Lolium multiflorum La.) during the winter and spring. Frame score differences remained until the beginning of the breeding season (BS), starting on average at 14 months of age. Weight gain between weaning and the beginning of BS was not different among frame scores (0.740 kg/day, on average). Body weights at the beginning of the BS were significantly different, of 255.7 kg (53.3% of the mature weight) for small heifers, 285.0 kg (59.4%) for medium heifers, and 307.6 kg (64.1%) for large heifers. Ovarian activity at the beginning of the BS was not different among the three groups. The average weight gain values during the BS of 0.492, 0.472, and 0.421 kg/day for small, medium, and large heifers, respectively, were significantly different. Pregnancy rates were not different among groups (small, 71.4%; medium, 76.4%; and large, 76.5%). Frame score did not influence the reproductive performance of heifers, but the small and medium heifers conceived 29 and 20 days earlier, respectively, than the large heifers

Teores de enxofre de um latossolo amarelo, após manejos tradicionais de capoeira sem adubação.

Ministério da Educação e do Desporto e Faculdade de Ciências Agrárias do Pará.1) Foi determinada a capacidade de troca de cátions das séries Sede e Babaçu, integrantes dos Podzólicos Vermelho-amarelo existentes na Estação Experimental da Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC),localizada no município de Santa Inês, Estado do Maranhão. Usou-se a metodologia tradicional, que consiste em somar os cátions trocáveis, também conhecida como CTC indireta, e a metodologia da saturação do solo com cátions monovalentes, a CTC direta. Embora apresentando minerologia semelhante ao longo dos subhorizontes, a Série Babaçu apresentou, em média, o dobro da capacidade de troca da Série Sede. A CTC direta apresentou valores mais altos que a CTC indireta.2) O efeito da inoculação de fungos micorrízicos Acaulospora sp, Gigaspora margarita e Scutellospora heterogama (isolados de Brachiaria decunbens) em plantas de taxi branco da terra firme {Sclerolobiumpaniculatum. Vogel) foi estudado em ensaio conduzido em vasos plásticos contendo 3 kg de Latossolo Amarelo Álico de textura média, fumigado com brometo de metila, em casa de vegetação. Utilizou-se como delineamento experimental blocos ao acaso com quatro repetições. As sementes foram coletadas no campo do Centro de Pesquisa Agrofloreslal da Amazônia Oriental-EMBRAPA/CPATU/Belém- PA e semeadas em caixas de plástico contendo areia de mina lavada. Como adubo foram utilizadas três fontes naturais de fósforo: Pirocaua, Jandiá e Trauíra. Foram avaliados a percentagem de colonização das raízes e o número de esporos. Acaulospora sp apresentou efeito positivo na taxa de colonização micorrizica (TMC), seguido de Scutellospora heterogama e Gigaspora margarita quando combinado com adubo Jandiá.3) Com o objetivo de avaliar os teores de N, P, K, Ca, Mg e S nas diversas partes de plantas de malva, mediante a técnica do elemento faltante em solução nutritiva, conduziu-se um experimento em casa de vegetação. O delineamento experimental foi inteiramente casualizado com 5 repetições e os tratamentos foram: completo, omissões de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. A coleta foi feita 60 dias após iniciada a aplicação dos tratamentos. Os resultados analíticos demonstraram que as concentrações dos macronutrientes nas diferentes partes da planta de malva diminuíram quando um determinado nutriente foi omitido na solução.4) Com o objetivo de avaliar a melhor combinação dos efeitos da inoculação de fungos micorrizicos arbusculares (FMAs) com diferentes tipos de fontes de fósforo natural, no desenvolvimento de plantas de taxi branco da terra firme (Sclerolobium paniculatum Vogel), foi realizado um experimento em casa de vegetação no Departamento de Solos da Faculdade de Ciências Agrárias do Pará em 1995. O solo utilizado no experimento foi um Latossolo Amarelo Alico de textura média, fumigado com brometo de metila, peneirado e colocado em vasos com capacidade de 3kg de solo. Utilizou-se como delineamento experimental blocos ao acaso com quatro repetições. As sementes foram coletadas nos campos do Centro de Pesquisa Agroflorestal da Amazônia Orientai (EMBRAPA/CPATU/Belém-PA) e semeadas em caixas de plástico contendo areia de mina lavada. Como adubo foram utilizados três fontes naturais de fósforo: Pirocaua, Jandiá e Trauíra. Os fungos micorrizicos arbusculares testados no experimento foram: Acaulospora sp, Gigaspora margarita e Scutellospora heterogama. provenientes de vasos de cultivo tendo como planta hospedeira Brachiaria decumbens, sendo fornecidos no ato do transplantio, aproximadamente, em média, 206, 430 e 1.904 esporos viáveis dos respectivos fungos, retirados de uma amostragem de mais ou menos 20g de uma mistura solo inóculo. A aplicação de fósforo teve efeito diferenciado sobre a infecção micorrízica nas raízes. Acaulospora sp apresentou efeito positivo na taxa de colonização micorrízica (TCM), seguido de Scutellospora heterogama e Gigaspora margarita quando combinado com adubo Jandiá. Embora pouco estudada a relação de fungos micorrízicos em solos amazônicos de baixa fertilidade natural, há necessidade de estudos alternativos para se obter uma produção satisfatória das culturas sem onerar os gastos com fertilizantes.5) O experimento foi realizado em casa de vegetação na Faculdade de Ciências Agrárias do Pará com o objetivo de determinar as deficiências nutricionais do capim quicuio da Amazônia (Brachiaria humidicola (Rendle) Schweickerdt), cultivado em um Plintossolo da ilha de Marajó, PA. O experimento constou de 13 tratamentos com 3 repetições, em um delineamento inteiramente casualizado. Os tratamentos foram: solução completa; solução completa mais calagem; testemunha e soluções obtidas com omissão de N, P, K, Ca, Mg, S, B, Cu, Zn e Mo; a partir da completa. Foram avaliadas a produção forrageira das raízes, parte aérea e o teor de elementos nutritivos das gramíneas aos 43 dias de idade. O quicuio da amazônia respondeu à aplicação de fertilizantes nas condições de solo da ilha de Marajó. O nutriente mais limitante foi o fósforo, havendo também respostas à aplicação de Mo, S e Ca. A calagem, através da neutralização do alumínio trocável, melhorou a produção do quicuio da Amazônia. O cálcio e, principalmente, o fósforo foram essenciais para o desenvolvimento radicular desta gramínea. O molibdênio foi a principal deficiência de micronutriente no solo.6) Com o propósito de comparar os efeitos da calagem e de doses crescentes de enxofre sobre as propriedades químicas de dois solos: Latossolo Vermelho Amarelo (LV) e Latossolo Vermelho escuro (LE), produção de matéria seca, teor e acúmulo de N, P, K, Ca, Mg e S do sorgo granífero, procedeu-se a incubação, por 25 dias, de amostras de solo com calcário e conduziu-se um ensaio em casa de vegetação com seis doses de enxofre: 0; 10; 20; 40; 80 e 160 mg/dm3, na forma de Na2S04. Cinqüenta dias após a semeadura, coletou-se a parte aérea das plantas e determinaram-se os teores e acúmulos de N, P, K, Ca, Mg e S. Os teores das bases trocáveis do solo aumentaram com a calagem, sendo que a saturação em bases ficou próxima a 80% nos dois solos. Os valores de pH e os teores de Ca e Mg nos tecidos de sorgo aumentaram com as adições de CaO e MgO aos solos. A produção de matéria seca do sorgo cultivado no solo LV foi superior em relação ao solo LE, e as doses crescentes de enxofre não influenciaram os teores foliares de N, P, K, Ca, Mg e S nos dois solos.7) A produção de liteira e os teores de nutrientes em plantio de eucalipto (Eucalyptus citriodora Hook.) foram estudados durante o período de janeiro a dezembro de 1993, em uma área no município de Barcarena (1° 30' S e 48° 42' W) microrregião de Belém, em Latossolo Amarelo, regime climático Afi na classificação de Kõppen, com espaçamento de l,5m x 1,5 m entre as árvores. Os resultados obtidos mostraram que a liteira alcançou valor da ordem de 2.643,60 kg/ha. Os nutrientes alcançaram os seguintes valores em kg/ha: N 18,18; P 0,52; K 5,60; Ca 29,50 e Mg 3,15. A fração folhas contribuiu com 1.335,1 kg/ha para a composição total da liteira.8) As várias formas isoenzimáticas de invertase desempenham importante papel no metabolismo de açúcar, como parte integrante do sistema fonte reservatório em cana-de-açúcar,sendo que os cultivares têm como característica genética um comportamento fisiológico e agronômico diferenciado. Os cvs. SP701143 e SP71-799foram plantados no campo em solo Podzólico Vermelho-Amarelo no município de Piracicaba, SP, com manejo adequado a essa cultura. Amostras das folhas (lâminas e bainhas) + 3 e +4 e dos 3S! e 4!i intemódios dos colmos foram colhidas em intervalos de tempo no período entre o 5" e o 7a mês após o plantio. Foram realizadas análises de proteína total solúvel, açúcares redutores, açúcares solúveis totais, estimado o valor de sacarose e determinação das isoenzimas de invertase ácida solúvel (pH 5,5), neutra (pH 7,0), da parede celular da lâmina foliar (pH 3,8), da bainha foliar (pH 3,5) e da parede celular do tecido do colmo (pH 2,2). O cv. SP71-799 mostrou-se mais eficiente do que o cv. SP70-1143, em termos de teor de sacarose, apresentando teores baixos de açúcares redutores nos intemódios do colmo. Os tecidos da lâmina foliar bainha e colmo de ambos os cultivares possuem duas invertases solúveis (uma ácida pH 5,5 e uma neutra pH 7,0) e uma ácida ligada à parede celular. Cada uma dessas isoformas apresenta um valor de pH ótimo. O cv. SP70-1143 apresenta teores relativamente altos de sacarose no colmo e alta atividade de invertase ácida nas folhas.9) A utilização de micorriza no preparo das mudas pode contribuir para aumentar esta taxa de crescimento e a sobrevivência, entretanto é necessário determinar a ocorrência de VAM e o grau de infecção. Com este objetivo analisou-se raízes de mudas originadas de sementes produzidas no viveiro da FCAP, raízes de mudas coletadas na floresta e raízes de árvores adultas. Amostras de solo foram também analisadas para quantificar e identificar os esporos. Todas as raízes examinadas mostraram bifas inter e intracelulares e arbúsculos. Nas amostras de material do solo foram encontrados esporos dos generos Acaulospora, Glomus e Scutellospora com oito diferentes espécies de Fungos VAM.10) O trabalho foi realizado em uma área no Município de Barcarena (le 30' S e 48s 42' W) em Latossolo Amarelo, regime climático Afi na classificação de Kõppen, com o objetivo de avaliar a produção de liteira e os teores de nutrientes em plantio de Tatapiririca {Tapirira guianensis Aubl.) estabelecido no espaçamento de l,5m x 1,5 m, durante o período de janeiro a dezembro de 1993. Os resultados obtidos mostraram que a liteira alcançou valor da ordem de 4.828,60 kg/ha e os nutrientes alcançaram os seguintes valores em kg/ha: N 42,57; P 1,05; K 9,35; Ca 93,61 e Mg 12,93. A fração folhas contribuiu com 3.698,10 kg/ha para a composição total da liteira.11) Foi estudada a dinâmica do enxofre num Latossolo Amarelo sob quatro sistemas de manejo de capoeira, no Município de Igarapé-Açu, Estado do Pará. Foram comparados quatro tratamentos: a) parcelas com a vegetação queimada e não-adubadas; b) parcelas onde a vegetação derrubada permaneceu como cobertura morta e não-adubadas; c) incorporação da vegetação triturada ao solo, sem adubo; d) parcelas testemunhas - vegetação de capoeira de 4 anos. Foram feitas coletas de solo durante os ciclos de cultivo, com amostras de quatro profundidades e épocas diferentes. Foi determinado o teor de enxofre e o pFÍ das amostras. Constatou-se, após a queima, a adição de grande quantidade de enxofre ao solo, porém logo se perdendo. A incorporação imobilizou parcialmente o enxofre contido na matéria orgânica. A cobertura morta diminuiu as perdas por lixiviaçào e erosão laminar, porém a mineralização do enxofre é mais lenta. O solo sob capoeira apresentou teores de enxofre sempre decrescentes durante a pesquisa.1) The CEC of the soil Sede and Babaçu belonging to the podzolic soil great group, from CEPLAC experimental station in the Santa Inês (Maranhão State), was determined. The methodologies used consisted. 1) Additon of exchangeable cations, known as indired CEC; 2) Soil saturation with monovalente cations known as direct CEC. Despite the fact that both soil series presented a similar mineralogy along the soil horizons, the Babaçu soil serie presented, in average, twice the value of CEC of the soil Sede serie, The direct CEC presented higher values than the indirect CEC.2) The inoculation ofmycorrhizal fungi Acaulospora sp, Gigaspora margarita e Scutellospora heterogama (isolated from Brachiaria decumhens) in plant of taxi-branco-da-terra-firme (Sclerohium paniculatum. Vogel) was studied in a glasshouse plastic plot containing 3 kg of yellow latosol fumigated by methyl bromide. A randomized blocks experimental desingn with four replicates per treatment was used. The seeds coilected in EMBRAPA/CPATU/ Belém-PA were sowed in plastic tray, containing washed sand. The sources of natural P used were Pirocaua, Jandiá and Trauíra. Percentage ofroot colonization and spore number were delermined. Plants inoculated with Acaulospora sp and fertilized with Jandiá schowed the higlest percentage of root colonization, followed by Scutellospora heterogama and Gigaspora margarita.3) Concentrations of N, P, K, Ca, Mg and S in the shoot and root tissues ofmalva were determined under greenhouse conditions using the missing element technique. A randomized experiment with five replicates and the: complete, omisson ofN, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn from a complete solution was used. Tissue harvest was done 60 days after application of the nutrient treatments. Results showed that the nutrients concentration in the diferent plants tissue varied as a function ofthe element omitted from the nutrient solution.4) The effects of different sources of natural P and arbuscular mycorrhizal fungi (FMAs) inoculation on the growth of Taxi-branco-da-terrafirme {Sclerolobium paniculatum Vogel) were evaluated under greenhouse conditions at Departamento de Solos, Faculdade de Ciências Agrárias do Pará- FCAP, Belém, Pará state, Brazil, in 1995. The experiment was carried out in 3 Kg plastic pot, containing sieved yellow alie latosol, fumigated with methyl bromide, under randomized blocks design with four replicales per tratment. The seeds collected in Embrapa/Cpatu-Belém/ PA were sowed in plastic tray, containing washed sand. The sources of natural P used were Pirocaua, Jandia and Trauíra.Three FMAs Acaulospora sp, Gigaspora margarita and Scutellospora heterogama which were previously multipiied in culture pot, containing Brachiaria decumbens as host plant. Inoculation was done at transplanting by depositing approximately 20g of soil inoculum, containing 206, 430 and 1904 spores, respectively, undereath the seedlings. The different sources of namral P demonstrated different effects on mycorrhizal root infection, Plants inoculated with Acaulospora sp and fertilized with Jandia showed the higlest percentage of root colonization, followed by Scutellospora heterogama and Gigaspora margarita. More study should be done to obtain the satisfactory crop produetion with reduced fertilization cost, by using FMAs in low fertility soil of Amazon.5) The missing element technique was used to determine nutrient deficiencies of the introduced pasture quicuio da amazônia {Brachiaria humidicola (Rendle) Schweickerdt) grown in greenhouse conditions on a piinthic soil ofthe Marajó island. The experimental design was a randomized experiment, with three replicates. Results showed that fertilizers application increased (a < 0,01) the top and root production ofthis grass specie. P was the principal nutrient which limited top growth of quicuio, followed by Mo, S, Ca and N. Liming also improved growth ofquicuio da amazônia. The quicuio da Amazônia root growth was limited by Zn, Mo, P, Ca.6) The effects ofliming and sulphur leveis on the chemical properties ofthe soil, dry matter production and nutrients accumulation on tops of sorghum cultivated on a Red Yellow (YRL) and Dark Red (DRL) latosol were determined by means of laboratory incubation and greenhouse pot trial. Soil samples were incubated with lime for 25 days, to which six dosis of sulphur (source: Na,S04) 0; 10; 20; 40; 80 and 160 mg/dm3. Fifty days after sowing, plants shoots were harvested and N, P, K, Ca, Mg and S contents were determined. Exchangeable cations and base saturation (V%) ofthe soils increased after liming, The pH, Ca and Mg contents of the plant shoots increased with the addition of CaO and MgO. The dry matter yield of sorghum was higher in plants cultivated on YRL than in DRL. Increasing sulphur concentration did not show any effect on nutrient contents of plant shoots in both soils.7) The litter production and nutrients supply of an Eucalyptus citriodora Hook pure stand were estimated at the Barcarena region of Pará State. The predominam soil site is an Yellow Latosol and the climate is classified as Afí according to Kõppen classification. The results showed that the litterfall reached values of 2.643,60 kg.ha-the leaf litter contributed with 3.698,10 of such total. The nutrients retum in kg.ha"1 were: 18,18 ofN; 0,52 of P;5,60of K; 29,50 of Ca and 3,15 of Mg.8) An important role is played by invertase isoenzymes in sugar metabolism, as part of the source-sink system in sugarcane, contributing to the physiological and agronomic behavior of the different cultivars. To test this, cvs. SP70-1143 and SP71-799 were cultivated in the field, Samples of leaves (blades and sheats) and stalks were harvested in time intervals between the 5th and the 7th month of growth. Total soluble protein, reducing and total soluble sugars were analysed and sucrose has been estimated. Determination of the activity ofthe following invertase isoenzymes: acidic (pH 5.5), neutral (pH 7.0), cell wall-linked (pH 2.2, 3.5 and 3.8) weere carried out. Cv. SP7I-799 showed higher leveis of sucrose than cv. SP70-1143, presenting low leveis of reducing sugars in the stalks intemodes. In both cultivars, the tissues of leaf blade and sheats and of the stalk intemodes have two soluble invertase isoenzyines, one acidic pH5.5 and one neutralpH 7.0, as well as an cell wall linked acidic isoenzyme; each one of lhese isoforms bears an optimum pH value. Cv. SP70- 1143 have relatively high leveis of sucrose in the stalks and high activity of acidic invertase in the leaves.9) Extractivism of the species {Aniba rosaeodora) once was very importam in the economy of the Amazon Region, however the intense pressure ofharvesting decreased considerably the population of the species. Plantation in agroforestry systems or reforestation is one altemative continuously to provide raw material but rosewood has showed slow growth rates. The utilization of mycorrhiza to produce seedlings in the norsery should contribute to increased rate of growth and survival. Roots of nursey seedlings of regenerants collected under the crown of trees in the forest and ffom mature trees were collected and analized with the objective to determine the occurrence of the Vesicular Arbuscular Mycorrhizal Fungi and the degree of infection. Soil samples near the roots were analized to quantitify and identify the spores. Ali root samples examined showed inter- and intracellulary hyphae, and arbuscles. In soil samples spores from eight differents species of the Vesicular-Arbuscular Mycorrhizal Fungi genera, Acaulospora, Glomus and Scutellospora, were found.10) It was determined the litterfall and nutrient content in a Tapirira guianensis forest, pure stand, for 12 months at the Barcarena region, Pará (Io 30' S, 48° 42' W). The predominam soil isan Yellow Latosoland the climate Afi according to Koppen classification. The spacing was 1.5 x 1.5m. The results of litterfall reached values of 4.828,60 kg.ha4 and nutrients leveis in kg.ha'1 were: 42,57 for N; 1,05 for PCkt; 9,35 for K+; 93,61 for Ca++ and 12,93 for Mg++. The leaf contributed with 3.698,10 kg.ha4 to the total litterfall.11) The sulphur dynamics of a Yellow Latosol in four managed secondary forest ecosystems in Igarapé-Açu, State of Pará was studied. The mangemenl systems were; a) buming of the secondary forest; b) mulching; c) biomass trituration of the secondary forest and incorporation to the soil; and d) secondary forest as the control plot. Soil samplings were collected during the culture cycle at four differents dephs and time. The pH and S leveis of the soils samples were determined in laboratory an increase in the S levei of the soil immediatelly after burning wich was lost by leaching. Biomass incorporation imobilized the S of the soil. Mulching decreased the losses of S by leaching but showed down the S mineralization. The control plot showed down the S mineralization. The control plot showed declining leveis of sulfur throught the research period

Genomic epidemiology reveals how restriction measures shaped the SARS-CoV-2 epidemic in Brazil

Abstract Brazil has experienced some of the highest numbers of COVID-19 infections and deaths globally and made Latin America a pandemic epicenter from May 2021. Although SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, important gaps remain in our understanding of local virus transmission dynamics. Here, we describe the genomic epidemiology of SARS-CoV-2 using near-full genomes sampled from 27 Brazilian states and an adjacent country - Paraguay. We show that the early stage of the pandemic in Brazil was characterised by the co-circulation of multiple viral lineages, linked to multiple importations predominantly from Europe, and subsequently characterized by large local transmission clusters. As the epidemic progressed, the absence of effective restriction measures led to the local emergence and international spread of Variants of Concern (VOC) and under monitoring (VUM), including the Gamma (P.1) and Zeta (P.2) variants. In addition, we provide a preliminary genomic overview of the epidemic in Paraguay, showing evidence of importation from Brazil. These data reinforce the need for the implementation of widespread genomic surveillance in South America as a toolkit for pandemic monitoring and providing a means to follow the real-time spread of emerging SARS-CoV-2 variants with possible implications for public health and immunization strategies