Yield estimation of forage oat (Avena sativa L.) Chihuahua variety: ruler and plate methods

Objetive: To analyze forage estimations with the direct method and the plant height. Diseño/Metodología/Aproximación: The treatments were the plants age, assessed in a random block design, with three repetitions. Simple linear regressions were carried out and adjusted using the SPSS statistical software. Resultados: The highest and lowest yields occurred at 105 and 30 days after sowing (DAS), with 5,412 and 783 kg DM ha-1, respectively. Height with the rule had a significant effect on forage production, with an R2 of 0.83. For each increase per cm the plants increased 56,134 kg DM ha-1. The height with the plate had an R2 of 0.97, so that 65.032 kg DM ha-1 are produced for each cm in height. Limitaciones del estudio/implicaciones: None Hallazgos/conclusiones: The forage accumulation in Avena sativa L., var. Chihuahua varied depending on the age of the plant. The heights calculated with the plate method, had greater reliability for the forage yield estimate, compared to the graduated rule method

Chronic arthritis leads to disturbances in the bone collagen network

Peer reviewe

Increased autophagy in EphrinB2-deficient osteocytes is associated with elevated secondary mineralization and brittle bone

Mineralized bone forms when collagen-containing osteoid accrues mineral crystals. This is initiated rapidly (primary mineralization), and continues slowly (secondary mineralization) until bone is remodeled. The interconnected osteocyte network within the bone matrix differentiates from bone-forming osteoblasts; although osteoblast differentiation requires EphrinB2, osteocytes retain its expression. Here we report brittle bones in mice with osteocyte-targeted EphrinB2 deletion. This is not caused by low bone mass, but by defective bone material. While osteoid mineralization is initiated at normal rate, mineral accrual is accelerated, indicating that EphrinB2 in osteocytes limits mineral accumulation. No known regulators of mineralization are modified in the brittle cortical bone but a cluster of autophagy-associated genes are dysregulated. EphrinB2-deficient osteocytes displayed more autophagosomes in vivo and in vitro, and EphrinB2-Fc treatment suppresses autophagy in a RhoA-ROCK dependent manner. We conclude that secondary mineralization involves EphrinB2-RhoA-limited autophagy in osteocytes, and disruption leads to a bone fragility independent of bone mass

Development of an operational synaptobrevin-based fluorescent substrate for tetanus neurotoxin quantification

Tetanus neurotoxin (TTx), produced by Clostridium tetani, is a two-chain polypeptide with a heavy molecular chain (HC; 100 kDa) and a light molecular chain (LC; 50 kDa) linked by a disulphide bridge. the low-molecular-mass chain is classified as a zinc metalloprotease (EC 3.4.24.68) with specific hydrolysis on synaptobrevin. With the known enzymic activity for the LC of TTx, we developed a quantification method using a quenched fluorescence peptide substrate based on the synaptobrevin sequence (fragments 73-82), suitable for direct determination of the whole TTx (HC+LC) even in crude production batches, without the necessity of purification and reduction steps to isolate the LC of TTx. the rate of substrate hydrolysis was 200 nmol/min and it was totally inhibited by EDTA, anti-recombinant fragment C antibody, and the cleavage was in a single bond (Gln-Phe) with purified and crude TTx. Besides, ELISA applied to the anti-TTx serum produced at our Institute showed cross-reaction with every fraction of the crude TTx extract. Another aspect is that TTx activity depends on the storage time, reaching a maximum on day 10. the results obtained suggest that the use of the new fluorescent substrate, Abz-synaptobrevin(73-82)-EDDnp, enables easy and quick determination of TTx. It is a good alternative to some of the existing methods such as flocculation assay, and it can replace, under some conditions, the biological assays (minimal mortal dose).CEPID, Ctr Appl Toxinol, Biochem & Biophys Lab, BR-05503900 São Paulo, BrazilButanan Inst, Immunopathol Lab, BR-05503900 São Paulo, BrazilButanan Inst, Sect Anaerob Vaccine, BR-05503900 São Paulo, BrazilUNIFESP, CEPID, Ctr Appl Toxinol, Dept Biophys, BR-05503900 São Paulo, BrazilUNIFESP, CEPID, Ctr Appl Toxinol, Dept Biophys, BR-05503900 São Paulo, BrazilWeb of Scienc