Correlations between the stability and adaptability statistics of popcorn cultivars

In plant breeding, correlations between the statistics of stability and adaptability of popcorn cultivars are not yet well understood. Therefore, the objectives of the present experiment was to investigate the correlations between s_di² \sigma_{\rm di}^{2} and b_i \beta_{\rm i} from Eberhart and Russell, ω_i from Wricke, \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} , \textS_\texti⁽²⁾ {\text{S}}_{\text{i}}^{(2)} and \textS_\texti⁽³⁾ {\text{S}}_{\text{i}}^{(3)} from Huehn, P_i from Lin and Binns and the rank-sum from Kang, and indicate the most reliable method for selecting popcorn cultivars. These statistics were estimated by data of crop yield from 19 Brazilian genotypes under 21 environments and popping expansion under 16 environments. The ω_i, \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} , \textS_\texti⁽²⁾ {\text{S}}_{\text{i}}^{(2)} , \textS_\texti⁽³⁾ {\text{S}}_{\text{i}}^{(3)} and s_di² \sigma_{\rm di}^{2} were positively and significantly correlated indicating that just one in these five statistics is sufficient for selecting stable genotypes although they were not correlated with the means of crop yield and popping expansion. The b_i \beta_{\rm i} was negatively and significantly correlated with P_i for crop yield indicating that the most adaptable genotypes tend to have the lowest estimates of P_i. Although P_i was not correlated with ω_i, \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} , \textS_\texti⁽²⁾ {\text{S}}_{\text{i}}^{(2)} , \textS_\texti⁽³⁾ {\text{S}}_{\text{i}}^{(3)} , or s_di² \sigma_{\rm di}^{2} statistics, it displayed positive correlation with the Index 1 (crop yield and popping expansion +  \textS_\texti⁽¹⁾ {\text{S}}_{\text{i}}^{(1)} rank) and Index 2 (crop yield and popping expansion + W_i) indicating that superior popcorn genotypes are also stable. Finally, both P_i and the rank-sum are useful statistics in breeding programmes where crop yield, popping expansion and stability are essential traits for selecting genotypes.     

A Web-based system for vineyards management, relating inventory data, vectors and images

A Web-based system is presented, integrating spatial information from remote sensing images, GPS measurements and inventory data. Monitoring, research and management of the grape production at Rio Grande do Sul State, Brazil (624,000 metric tons in 2006) can be done through a system entirely based in open-source codes. Information from three different sources are integrated: Information on production comes from the State’s Viticultural Inventory, detailing the regional yearly grape production; positional information comes from field GPS measurements of vine parcels and the system’s capabilities of making maps; imagery information comes from aerial or satellite images. Further capabilities on image classification leads to the identification of vine areas; this allows crossing this data with information provided by owners. This system allows both the monitoring of grape production for administrative purposes and investigations either on regional land and soil cover, or in other applications derived from image classification. The system concept can be readily extended to other applications in land use monitoring.     

Morphological comparison of wild,farmed and hybrid specimens of two South American silversides,Odontesthes bonariensis and Odontesthes hatcheri

In this study, body shape of hybrid and presumptive introgressed South American silversides was studied. Body shape of O. bonariensis and O. hatcheri from wild populations and farmed stocks was compared to provide basic information on the effects of fish farming on morphometric parameters. Subsequently, wild presumptive introgressed individuals and artificially hybridized farmed individuals were morphologically analysed to assess the effects of hybridization on the same parameters. Most farmed purebred individuals were shorter and higher than their wild counterparts, which is probably due to the favourable growth conditions compared to the wild habitat. However, the results evidenced that purebred individuals were more slender than both hybrid (farmed) fish and introgressed (wild) fish. Further studies on the growth performance of hybrid Odontesthes will be required in order to assess whether the combination of hybridization and sterilization could produce, under farming conditions, growth performances which satisfy the requirements of aquaculture.     

Daily rhythm of salivary and serum urea concentration in sheep

Background  

In domestic animals many biochemical and physiological processes exhibit daily rhythmicity. The aim of the present study was to investigate the rhythmic pattern of salivary and serum urea concentrations in sheep.     

The use of Kohonen neural networks for runoff–erosion modeling

Purpose

We investigated the application of Kohonen Neural Networks (KNNs) in order to estimate sediment yield based on runoff and climatological data in a semiarid region of Brazil. Accurate estimations of sediment yield are essential to improve the management of soil erosion in semiarid areas, where large quantities of sediments tend to be produced only periodically.

Materials and methods

The case study is an erosion plot within the São João do Cariri Experimental Basin, which is located in the semiarid portion of Paraíba State, Brazil. KNNs are unsupervised neural networks capable of reducing a multidimensional data set to a bidimensional matrix of features, which can be used for analysis and prediction purposes. A total of 60 rainfall events, which occurred between 1999 and 2002, were used to calibrate and test the model. The application of a multivariate linear regression (MLR) model was also carried out.

Results and discussion

Statistical indexes were used as criteria for evaluating the performance of the KNN and MLR models for the test data set. The correlation and relative bias of the KNN model estimations with those from observed data were 0.90 and ?4.39 %, respectively. A correlation of 0.70 and a relative bias of 15.63 % were found from the comparison of sediment yields obtained by the MLR model with those of the observed data. Analysis of the outcomes indicates that the KNN model, which is capable of detecting and extracting nonlinear trends, produced more reliable results than the regression model.

Conclusions

The KNN model results appear to be superior to those generated by the MLR model and suggest that the developed methodology may be applied to similar case studies.     

Prior and concomitant dehydroepiandrosterone treatment affects immunologic response of cultured macrophages infected with Trypanosoma cruzi in vitro?

DHEA, a steroid hormone synthesized from cholesterol by cells of the adrenal cortex, plays an essential role in enhancing the host's resistance to different experimental infections. Receptors for this hormone can be found in distinct immune cells (especially macrophages) that are known to be the first line defense against Trypanosoma cruzi infection. These cells operate through an indirect pathway releasing nitric oxide (NO) and cytokines such TNF-α and IL-12 which in turn trigger an enhancement of natural killer cells and lymphocytes which finally secrete pro and anti-inflammatory cytokines. The effects of pre- and post-infection DHEA treatment on production of IL-12, TNFα and NO were evaluated. T. cruzi infected macrophages post treated with DHEA displayed enhanced concentrations of TNF-α, IL-12 and NO. Probably, the mechanisms that induced the production of cytokines by infected cells are more efficient when the immune system has been stimulated first by parasite invasion, suggesting that the protective role of DHEA is greater when administered post infection.     

Determination of in vitro digestibility of forage species used in ruminant feeding

Within the evaluation of the quality of forage resources, the main parameter that defines it is the digestibility of dry matter, which together with the amount of neutral and acidic detergent fibers and crude protein constitutes the basic information to assess forages which are supplied in the diet of the cattle. This research was carried out at the University of Los Llanos (Villavicencio, Colombia), and its objective was to determine the digestibility of three forages in cattle through three different in vitro techniques: inoculation with ruminal fluid and with feces and enzymatic digestibility technique, making the comparison with the in situ technique in order to validate the techniques and equipment that are being used for these procedures. The following species were evaluated: Pennisetum purpureum (PP), Tithonia diversifolia (TD), and Bauhinia variegata (BV), assessing the curve and rate of degradation of dry matter (DM), neutral detergent fiber (NDF), and total protein (TP) (0 to 72 h). A design of repeated measures was used, under which the analysis of variance was carried out to determine the ranges of deviation between the techniques and thus establish the trend of the data; the variables evaluated were the DM, NDF, and TP digestibilities of the three forages using the four techniques (three in vitro and one in situ). After verifying the differences between the variances of the digestibilities and checking the sphericity assumption with the Mauchly test, multiple comparisons were made with the Bonferroni test with a significance of 5%. The digestibility of DM, NDF, and TP varied between 38.62 and 44.22, 54.18 and 66.97, and 47.54 and 57.05%; 49.07 and 70.70, 72.52 and 75.44, and 62.61 and 74.02%; 29.93 and 34.84, 26.21 and 70.88, and 25.67 and 50.60% respectively in forages PP, TD, and BV, depending on the technique used for their estimation. Despite finding statistically significant differences between several of the comparisons made in the digestibility techniques, a high coefficient of determination and a high correlation between the in vitro estimations with respect to the in situ estimation were found; therefore, it is possible to use these techniques routinely thus avoiding the need to have cattle with fistulae to perform digestibility tests, with enzymatic digestibility technique being the most practical one.