Bubble kinetics in a steady-state column of aqueous foam

We measure the liquid content, the bubble speeds, and the distribution of bubble sizes, in a vertical column of aqueous foam maintained in steady-state by continuous bubbling of gas into a surfactant solution. Nearly round bubbles accumulate at the solution/foam interface, and subsequently rise with constant speed. Upon moving up the column, they become larger due to gas diffusion and more polyhedral due to drainage. The size distribution is monodisperse near the bottom and polydisperse near the top, but there is an unexpected range of intermediate heights where it is bidisperse with small bubbles decorating the junctions between larger bubbles. We explain the evolution in both bidisperse and polydisperse regimes, using Laplace pressure differences and taking the liquid fraction profile as a given.Comment: 7 pages, 3 figure

Need morphology always be required for new species descriptions?

Despite the widespread and common use of DNA-sequence data to estimate phylogenies, support or contest classifications, and identify species using barcodes, they are not commonly used as the primary or sole source of data for describing species. This is possibly due to actual or perceived pressure from peers to include morphology as the primary source of data for species descriptions. We find no compelling evidence to exclude DNA-only descriptions, or to insist that morphology always be included in a species description. It is not the data type per se that is important, but the science behind the taxonomic conclusions. Using alternative kinds of data for descriptions should not cause problems for taxonomy if links are kept with type specimens

Rapamycin-inspired macrocycles with new target specificity

Rapamycin and FK506 are macrocyclic natural products with an extraordinary mode of action, in which they form binary complexes with FK506-binding protein (FKBP) through a shared FKBP-binding domain before forming ternary complexes with their respective targets, mechanistic target of rapamycin (mTOR) and calcineurin, respectively. Inspired by this, we sought to build a rapamycin-like macromolecule library to target new cellular proteins by replacing the effector domain of rapamycin with a combinatorial library of oligopeptides. We developed a robust macrocyclization method using ring-closing metathesis and synthesized a 45,000-compound library of hybrid macrocycles (named rapafucins) using optimized FKBP-binding domains. Screening of the rapafucin library in human cells led to the discovery of rapadocin, an inhibitor of nucleoside uptake. Rapadocin is a potent, isoform-specific and FKBP-dependent inhibitor of the equilibrative nucleoside transporter 1 and is efficacious in an animal model of kidney ischaemia reperfusion injury. Together, these results demonstrate that rapafucins are a new class of chemical probes and drug leads that can expand the repertoire of protein targets well beyond mTOR and calcineurin.Peer reviewe

Efeito da utilização da somatotropina bovina recombinante (bST) sobre a produção de leite em búfalas Effect of recombinant bovine somatotropin (bST) utilization on milk production from buffaloes

O objetivo deste trabalho foi estudar o resultado da utilização da somatotropina bovina recombinante (bST) atuando na produção de leite em búfalas da raça Murrah. Empregaram-se 28 búfalas multíparas da raça Murrah, divididas em dois grupos homogêneos de 14 animais, recebendo os seguintes tratamentos: Grupo 1 <FONT FACE=Symbol>&frac34;</FONT> Controle (solução salina) e Grupo 2 <FONT FACE=Symbol>&frac34;</FONT> 500 mg de bST/cabeça a cada 14 dias, durante 7 meses. Búfalas tratadas com bST exibiram incrementos de 48,52%, 32,80% e 32,80% nas produções total de leite, corrigida, depois, para 4% de gordura e média diária, respectivamente. A somatotropina elevou a produção total de gordura sem alterar a porcentagem dela no leite. A administração de bST não afetou a porcentagem de proteína do leite todavia, a produção total de proteína foi aumentada. Quanto à duração da lactação, o tratamento com bST diferiu do controle, o que demonstra a maior persistência da lactação de búfalas tratadas com bST.<br>The objective of this work was to study the effect of recombinant bovine somatotropin (bST) utilization on milk production from Murrah buffaloes. Twenty eight multiparous Murrah buffaloes were used and divided into two homogeneous groups of 14 animals, receiving the following treatments: Group 1 <FONT FACE=Symbol>&frac34;</FONT> Control (salt solution) and Group 2 <FONT FACE=Symbol>&frac34;</FONT> 500 mg of bST/head every 14 days during 7 months. Buffaloes treated with bST presented increase of 48.52%, 32.80% and 32.80% on total milk yield, adjusted to 4% of fat and average daily milk yield, respectively. Somatotropin increased total fat milk yield without alter fat percentage of milk. Administration of bST did not affect protein percentage of milk while total protein milk yield increased. As for the lactating period, the treatment with bST differed of the control, what might have denoted in larger persistence of the lactation from buffaloes treated with bST