The reproductive cycle of the male sleep snake Sibynomorphus mikanii (Schlegel, 1837) from southeastern brazil

This study describes the male reproductive cycle of Sibynomorphus mikanii from southeastern Brazil considering macroscopic and microscopic variables. Spermatogenesis occurs during spring-summer (September-December) and spermiogenesis or maturation occurs in summer (December-February). The length and width of the kidney, the tubular diameter, and the epithelium height of the sexual segment of the kidney (SSK) are larger in summer-autumn (December-May). Histochemical reaction of the SSK [periodic acid-Schiff (PAS) and bromophenol blue (BB)] shows stronger results during summer-autumn, indicating an increase in the secretory activity of the granules. Testicular regression is observed in autumn and early winter (March-June) when a peak in the width of the ductus deferens occurs. The distal ductus deferens as well as the ampulla ductus deferentis exhibit secretory activities with positive reaction for PAS and BB. These results suggest that this secretion may nourish the spermatozoa while they are being stored in the ductus deferens. The increase in the Leydig cell nuclear diameter in association with SSK hypertrophy and the presence of sperm in the female indicate that the mating season occurs in autumn when testes begin to decrease their activity. The peak activity of Leydig cells and SSK exhibits an associated pattern with the mating season. However, spermatogenesis is dissociated of the copulation characterizing a complex reproductive cycle. At the individual level, S. mikanii males present a continuous cyclical reproductive pattern in the testes and kidneys (SSK), whereas at the populational level the reproductive pattern may be classified as seasonal semisynchronous. © 2012 Wiley Periodicals, Inc.

Immunoexpression of aromatase and estrogen receptors β in stem spermatogonia of bullfrogs indicates a role of estrogen in the seasonal spermatogonial mitotic activity

Bullfrog stem spermatogonia, also named primordial germ cells (PGCs), show strong testosterone immunolabeling in winter, but no or weak testosterone immunoexpression in summer. Thus, the role of testosterone in these cells needs to be clarified. In this study, we proposed to evaluate whether PGCs express aromatase and estrogen receptors, and verify a possible role of estrogen in PGCs seasonal proliferation. Testes of male adult bullfrogs, collected in winter (WG) and summer (SG), were fixed and embedded in historesin, for quantitative analysis, or paraffin for immunohistochemistry (IHC). The number of haematoxylin/eosin stained PGCs/lobular area was obtained. Proliferating cell nuclear antigen (PCNA), aromatase, estrogen receptor β (ERβ) and PCNA/ERβ double immunolabeling were detected by IHC. The number of PCNA-positive PGCs and the histological score (HSCORE) of aromatase and ERβ immunolabeled PGCs were obtained. Although the number of PGCs increased significantly in WG, a high number of PCNA-positive PGCs was observed in summer. Moreover, aromatase and ERβ HSCORE was higher in SG than WG. The results indicate that PGCs express a seasonal proliferative activity; the low mitotic activity in winter is related to the maximal limit of germ cells which can be supported in the large lobules. In SG, the increased ERβ and aromatase HSCORE suggests that testosterone is converted into estrogen from winter to summer. Moreover, the parallelism between the high PGCs mitotic activity and ERβ immunoexpression suggest a participation of estrogen in the control of the PGCs seasonal proliferative activity which guarantee the formation of new germ cysts from summer to next autumn. © 2012 Elsevier Inc.

Indices of competition and bio-agroeconomic efficiency of lettuce and tomato intercrops in greenhouses

Intercropping is a cropping system for the production of greenhouse vegetables. It uses space more efficiently, thus reducing the cost of production. Intercropping tomato and lettuce has not been studied, but knowledge of the competitive and agroeconomic indices of these vegetables can help in the management of the intercropping system. The objectives of this study were to assess, through biological and agroeconomic indices, the competition between species and the profitability of intercropping tomato and lettuce at different times of transplantation over two growing seasons (autumn-winter and summer-winter) in greenhouse conditions. In autumn-winter, two experiments were conducted with a randomised complete-block design and five replicates. Tomato and lettuce were the main crops in the individual experiments. Treatments were arranged in a factorial of two cropping systems (intercropping and individual crops) with four transplants of the secondary crop (0, 10, 20 and 30 days after) plus an additional treatment (individual main crop). These two experiments were repeated in summer-winter. Tomato was the dominant crop regardless of transplant order. Intercropping systems established with transplants of both species on the same day had higher values of indices of competition and bio-agroeconomic efficiency than systems with longer periods of transplants between main and secondary crops. The intercropping of lettuce and tomato in greenhouses, regardless of transplant time or order, had bio-agroeconomic advantages over individual crops. The transplantation of tomato after lettuce is recommended for greater profitability.

Seasonal effects on semen and testosterone in zebu and taurine bulls

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Season of birth as a risk factor for multiple sclerosis in Brazil

Risk factors for development of multiple sclerosis (MS) are still a matter of debate. Latitude gradient, vitamin D deficiency and season of birth are among the most investigated environmental factors associated with the disease. Several international studies suggest that birth in spring is a substantial risk factor for MS. We investigated the season of birth as a potential risk for MS in different geographical regions of Brazil. We conducted a cross-sectional retrospective study with 2257 clinically definite MS patients enrolled in 13 Brazilian MS clinics in the south, southeast, and northeast regions of Brazil. Demographic and clinical data relating to date of birth and clinical features of the disease were collected and analysed, and subsequently compared with birth date among the general Brazilian population. The distribution of date of birth of MS patients showed an increase in spring and a decrease in autumn, with no difference being observed in the other seasons. In conclusion, season of birth is a probable risk factor for MS in most parts of Brazil. These findings may be related to the role that vitamin D plays in MS pathogenesis. © 2013 Elsevier B.V. All rights reserved.

Evaluation of ornamental grasses submitted to water stress

The work was carried out at the College of Agricultural and Veterinary Sciences of the State University of São Paulo (UNESP/FCAV), Campus of Jaboticabal, Brazil, aiming to study the tolerance response to water stress and capacity of regeneration after mowing three different ornamental grasses used in Brazilian landscaping: Imperial zoysia grass (Zoysia japonica 'Imperial'), zoysia grass (Zoysia japonica) and St. Augustine grass (Stenotaphrum secundatum). The experimental design was entirely randomized in a factorial scheme 33 (three grass species: Zoysia japonica 'Imperial', Zoysia japonica and Stenotaphrum secundatum; in three water stress conditions: under full sun, with and without irrigation, and under greenhouse conditions without irrigation) with four replications per plot. The irrigation was performed using microsprinklers with a flow of 0.28 L s-1, and the grasses of all plots were mowed monthly. The evaluations were executed monthly, before mowing the grass, in the beginning of each season, that means, in October (for Spring evaluation), January (for Summer), April (for Autumn) and July (for Winter), considering the Brazilian climate conditions. The evaluated parameters were shoot height and total dry mass. The data were submitted to the variance analysis and the means were compared by the Tukey test at 5% confidence level. The grasses grown under greenhouse conditions, without irrigation, showed higher height and lower dry mass weight averages, what possibly indicates that the plants etiolated. The grasses grown under full sun, either with or without irrigation, showed a similar plant development. The S. secundatum species showed greater tolerance to water stress in October, month that followed the longest dry period. The total dry mass was gradually reduced during the experiment for all grasses grown under greenhouse conditions without irrigation; however, a great general tolerance to water stress was observed for all grasses because all of them survived along nine months without irrigation.

Propagation of Camptosema grandiflorum native to Brazil by seeds and cuttings

Camptosema grandiflorum Benth., belonging to Fabaceae, is a voluble climber plant native to Brazil. Plants bloom in autumn-winter, producing long and hanging inflorescences with showy red flowers, which are much visited by hummingbirds. The leaves are also attractive, composed by three leaflets. It can be propagated by seeds or cuttings, but both seed germination and cutting rooting percentages are very low. Thus, the objective of this work was to study the effect of different temperatures on seed germination and of different indolebutyric acid (IBA) concentrations on the rooting of cuttings of C. grandiflorum. The experiment was set up at the São Paulo State University, located in Jaboticabal, São Paulo State, Brazil. The germination study was conducted in an entirely randomized design with six different temperatures (constant at 20, 25, 30 and 35°C; and alternated at 20-30 and 25-35°C, with a photoperiod of 12 hours) and four replications of 25 seeds each, placed in plastic boxes with vermiculite. The percentage of germination and the speed germination index (SGI) were evaluated. An entirely randomized block design was adopted for the cutting rooting evaluation, with four IBA concentrations (0; 1,000; 2,000; and 3,000 mg kg-1) and five replications of ten cuttings each, comprising 200 cuttings. After 30 days from the beginning of the rooting experiment, data referring to rooting percentage, number and length of roots and dry weight of roots were collected. For the seed germination experiment, fastest germination and highest germination percentage (87%) were obtained when seeds were maintained under the constant temperature of 30°C. For the cutting experiment, the concentrations of 2,000 and 3,000 mg kg-1 of IBA promoted the highest rooting percentages (98.5 and 94.1%, respectively) and number of roots. There were no statistical differences among the IBA concentrations for length of roots and dry weight of roots.

Biologia populacional e reprodutiva do camarão sete-barbas na Baía de Santos, São Paulo

We investigated the sexual maturity, reproductive period and juvenile recruitment (both associated with salinity and temperature of bottom water) and sex-ratio of Xiphopenaeus kroyeri in Santos Bay, São Paulo. Monthly samples were obtained from June 2008 through May 2009 along four transects. Individuals were measured, sexed and the developmental stage of the reproductive system was macroscopically determined. The mean carapace length of females was larger than that of males. Females attained physiological maturity with 25.5 mm and males with 16.8 mm. The reproductive period was continuous with higher proportions of reproductive females in autumn. Although not significant, in February occurs a peak of reproductive females similar to March. An intermediate peak of these females occurs between August and October and it contributed to the recruitment in summer. The smallest amount of juveniles after the main peak of spawning (February, March and April) can be explained by migration or consequences of open access for fishery that occurs on June. The overall sex-ratio was approximately 1:1. However, when considering the spatial distribution, we observed a greater amount of reproductive females in shallow waters in the bay. The differential distribution between the sexes could be associated with appropriated areas to spawn. The current legal off-season occurs between March and May, and, according to our results of the frequency of reproductive females, we suggest the inclusion of February in the off-season.

Estimativas da radiação global incidente em superfícies inclinadas com base na razáo de insolação

Estimating equations of global radiation based on the sunshine duration were proposed for horizontal surface and with inclination of 12.85, 22.85 and 32.85° facing the North in Botucatu, SP, Brazil, in monthly, seasonal and annual groupings of data. Simple linear correlations were applied (for definition of the linear and angular coefficients of Angstrom-Prescott model), in a database measured in all three inclinations in different periods (22.85°: 04/1998 to 07/2001; 12.85°: 08/2011 to 02/2003; and 32.85°: 03/2003 to 12/2007) concomitant with horizontal measures and sunshine duration. The statistical performance of the model was analysed by the means absolute error (MBE), the square root of the mean square error (RMSE) and the index adjustment (d). The minimum global radiation transmissivity varied from 14.35% in August (12.85°) to 27.86% in December (32.85°) and the maximum transmissivity ranged between 62.10% and 78.90%, for June (32.85°) and December (12.85°). Increasing the angle of inclination surface increased the scattering and decreased the index of adjustment and performance. The worst results were found for application of the seasonal and annual models in the months of autumn and winter for 32.85° (RMSE below 42.93% and adjustment superior to 0.4693).

Épocas de semeadura e manejos de corte de milheto cultivado no outono-inverno e efeitos na cultura da soja em sucessão sob plantio direto

Pós-graduação em Agronomia (Agricultura) - FCA

Análise do período de defeso do camarão marinho Artemesia longinaris através da maturidade ovariana anual

Pós-graduação em Aquicultura - FCAV

Biologia reprodutiva de três espécies de serpentes da Família Viperiade da região neotropical

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dinâmica populacional das macrófitas aquáticas emersas Spartina alterniflora Loiseleur, Crinum procerum Carey e Scirpus californicus Steud, na bacia do rio Itanhaém, SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de alface crespa, acúmulo de nitrato na planta e lixiviação do íon no solo em função de adubação nitrogenada

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produtividade de milho em plantio direto após plantas de cobertura

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)