Mecanismos de transferência de massa na desidratação osmótica de goiaba em soluções de sacarose, sucralose e açúcar invertido Mass transfer mechanisms during the osmotic dehydration of guava in sucrose, sucralose and inverted sugar solutions

O objetivo deste trabalho foi avaliar o efeito da concentração de soluções de sacarose, sucralose e açúcar invertido sobre a cinética da desidratação osmótica de pedaços de goiaba. Frações de 1/12 do fruto foram imersas em soluções de sacarose a 0,5 e 0,4 g mL-1; de sacarose a 0,3 g mL-1 + sucralose a 0,2 g L-1 e em xarope de açúcar invertido, a 50 ºC, por 2 h, sob agitação de 60 min. A solução de açúcar invertido promoveu maior perda de água e redução de massa nas amostras de goiaba submetidas à desidratação osmótica. O melhor desempenho foi obtido para o tratamento em solução de sacarose a 0,4 g mL-1; com perda de água e redução de massa semelhantes aos valores obtidos na imersão em solução de sacarose a 0,5 g mL-1 e ganho de sólidos similar ao observado em solução de sacarose a 0,3 g mL-1.The present work aimed at investigating the effect of sucrose, sucralose and inverted sugar solutions on the kinetics of osmotic dehydration of guava pieces. The fruits were cut in twelfths and immersed in sucrose solutions at 0.5 and 0.4 g mL-1; of sucrose at 0.3 g mL-1 + sucralose at 0.2 g L-1 and in inverted sugar syrup for 2 h at 50 ºC, under agitation of 60 min. The undiluted inverted sugar solution promoted the highest levels of water loss and weight reduction in osmo-dehydrated guava pieces. The best overall performance was achieved by immersing guava pieces in sucrose solutions at 0.4 g mL-1 which led to water loss and mass reduction of similar values attained with sucrose solutions at 0.5 g mL-1; whereas maintaining the same level of solids gain achieved with sucrose solutions at 0.3 g mL-1

Adaptability and stability evaluation of maize hybrids using Bayesian segmented regression models.

The occurrence of genotype by environment interaction (G x E), which is defined as the differential response of genotypes to environmental variation, is frequently reported in maize cultures, making it challenging to recommend cultivars. Methods allowing to study the potential nonlinear pattern of genotype responses to environmental variation allied to prior beliefs on unknown parameters are interesting to evaluate the phenotypic adaptability and stability of genotypes. In this context, the present study aimed to assess the adaptability and stability of maize hybrids, by using the Bayesian segmented regression model, and evaluate the efficacy of using informative and minimally informative prior distributions for the selection of cultivars. Randomized complete-block design experiments were carried out to study the yield (kg/ha) of 25 maize hybrids, in 22 different environments, in Northeastern Brazil. The Bayesian segmented regression model fitted using informative prior distributions presented lower credibility intervals and Deviance Criterium of Information values, compared to those obtained by fitting using minimally informative distributions. Therefore, the model using informative prior distributions was considered for the adaptability and stability evaluation of maize genotypes. Once most northeastern farmers in Brazil have limited capital, the genotype P4285HX should be considered for planting, due to its high yield performance and adaptability to unfavorable environments

The drebrin/EB3 pathway drives invasive activity in prostate cancer

Prostate cancer is the most common cancer in men and the metastatic form of the disease is incurable. We show here that the drebrin/EB3 pathway, which co-ordinates dynamic microtubule/actin filament interactions underlying cell shape changes in response to guidance cues, plays a role in prostate cancer cell invasion. Drebrin expression is restricted to basal epithelial cells in benign human prostate but is upregulated in luminal epithelial cells in foci of prostatic malignancy. Drebrin is also upregulated in human prostate cancer cell lines and co-localizes with actin filaments and dynamic microtubules in filopodia of pseudopods of invading cells under a chemotactic gradient of the chemokine CXCL12. Disruption of the drebrin/EB3 pathway using BTP2, a small molecule inhibitor of drebrin binding to actin filaments, reduced the invasion of prostate cancer cell lines in 3D in vitro assays. Furthermore, gain- or loss-of-function of drebrin or EB3 by over-expression or siRNA-mediated knockdown increases or decreases invasion of prostate cancer cell lines in 3D in vitro assays, respectively. Finally, expression of a dominant-negative construct that competes with EB3 binding to drebrin, also inhibited invasion of prostate cancer cell lines in 3D in vitro assays. Our findings show that co-ordination of dynamic microtubules and actin filaments by the drebrin/EB3 pathway drives prostate cancer cell invasion and is therefore implicated in disease progression