Advances in prevention and therapy of neonatal dairy calf diarrhoea : a systematical review with emphasis on colostrum management and fluid therapy

Neonatal calf diarrhoea remains the most common cause of morbidity and mortality in preweaned dairy calves worldwide. This complex disease can be triggered by both infectious and non-infectious causes. The four most important enteropathogens leading to neonatal dairy calf diarrhoea are Escherichia coli, rota-and coronavirus, and Cryptosporidium parvum. Besides treating diarrhoeic neonatal dairy calves, the veterinarian is the most obvious person to advise the dairy farmer on prevention and treatment of this disease. This review deals with prevention and treatment of neonatal dairy calf diarrhoea focusing on the importance of a good colostrum management and a correct fluid therapy

Intracellular directed evolution of proteins from combinatorial libraries based on conditional phage replication

Directed evolution is a powerful tool to improve the characteristics of biomolecules. Here we present a protocol for the intracellular evolution of proteins with distinct differences and advantages in comparison with established techniques. These include the ability to select for a particular function from a library of protein variants inside cells, minimizing undesired coevolution and propagation of nonfunctional library members, as well as allowing positive and negative selection logics using basally active promoters. A typical evolution experiment comprises the following stages: (i) preparation of a combinatorial M13 phagemid (PM) library expressing variants of the gene of interest (GOI) and preparation of the Escherichia coli host cells; (ii) multiple rounds of an intracellular selection process toward a desired activity; and (iii) the characterization of the evolved target proteins. The system has been developed for the selection of new orthogonal transcription factors (TFs) but is capable of evolving any gene—or gene circuit function—that can be linked to conditional M13 phage replication. Here we demonstrate our approach using as an example the directed evolution of the bacteriophage λ cI TF against two synthetic bidirectional promoters. The evolved TF variants enable simultaneous activation and repression against their engineered promoters and do not cross-react with the wild-type promoter, thus ensuring orthogonality. This protocol requires no special equipment, allowing synthetic biologists and general users to evolve improved biomolecules within ~7 weeks

Secagem da madeira de louro preto (Nectandra cuspidata) em estufa de micro-ondas

Microwave drying will play an important role in the industrialization of timber in the near future, because improved dimensional stability and increased mechanical strength of wood are dependent on its drying. The objective of this study was to evaluate the drying of Louro preto wood using the microwave process and its influence on drying time, final moisture content, and formation of checks. A program originally developed for Mahogany wood was used due to the similarity between the basic density values of the two wood species. To this end, three (3) drying processes were conducted: drying S1, with initial average moisture content above the fiber saturation point (FSP), reached 13.99% of the final average moisture content after 2h 25min; whereas drying S2 and S3, with initial average moisture contents below the FSP, showed 14.00 and 14.62% of the final average moisture content after 2h 8min and 2h 2min, respectively. The drying processes were considered fast, and the difference in the initial moisture contents of the samples showed the influence of the treatments in the formation of end and surface checks. Drying S2 was more prone to present surface checks than end checks, whereas internal checks were not found in any of the drying processes performed