Bounded variation in the mean

It is shown that the concept of bounded variation in the mean is not a meaningful generalization of ordinary bounded variation. In fact, it is a characterization of functions which differ from functions of bounded variation on a zero set.

     

Flow-Induced Precipitation in Thin Capillaries Creates Helices,Lamellae, and Tubes

Precipitation reactions under flow in confined media are relevant to the control of pathological biomineralization, processes affecting aquifers, and challenges in the petroleum industry. Here we show that for a simple geometry, such conditions create macroscopic structures including helices, tubes, lamellae, slugs, and disordered patterns. All structures emerge when salt solution is slowly injected into thin capillaries filled with hydroxide solution. For the helices, the pitch is proportional to the pump rate revealing a constant period of 0.63 s. Different morphologies of the insoluble metal hydroxide can co-exist causing random transitions along the capillary. On average, 15 % of the final system contains residual hydroxide solution. While mechanically stable for flow speeds above 25 mm min⁻¹, structures collapse and sediment for slower injection speeds. Some of the observed features share similarities with precipitate tubes in chemical gardens and the dynamics of liquid–liquid pipe flow.     

Norms and essential norms of linear combinations of endomorphisms

We compute norms and essential norms of linear combinations of endomorphisms on uniform algebras.

     

Male pheromone protein components activate female vomeronasal neurons in the salamander Plethodon shermani

Background  

The mental gland pheromone of male Plethodon salamanders contains two main protein components: a 22 kDa protein named Plethodon Receptivity Factor (PRF) and a 7 kDa protein named Plethodon Modulating Factor (PMF), respectively. Each protein component individually has opposing effects on female courtship behavior, with PRF shortening and PMF lengthening courtship. In this study, we test the hypothesis that PRF or PMF individually activate vomeronasal neurons. The agmatine-uptake technique was used to visualize chemosensory neurons that were activated by each protein component individually.     

Drift-resistant SNR scalable video coding.

We address the problem of enhancement layer drift estimation for fine granular scalable video. An optimal per-pixel drift estimation algorithm is introduced. The encoder assumes that there is some truncation of the enhancement layer, which does not allow the enhancement layer reference to be properly reconstructed, and the encoder recursively estimates the associated drift and chooses coding modes accordingly. The approach yields performance gains of about 1 dB across low to medium rates. In addition, we investigate dual frame prediction, for both base and enhancement layer, with pulsed-quality allocation in the base     

Experimental studies of the Progressing Batch Reactor

The data obtained in the single reactor experiments has shown the use of 1/2-in. chips to produce results that are reliable and repeatable. These data are not sensitive to variations in wood chip packing or prehydrolysis procedures. The latter is important since multireactor studies will try various prehydrolysis strategies while investigating the operational characteristics of a multireactor system. The possible importance of hydrodynamics within the wood chip bed was demonstrated by the data from the 1/4- and 1/8-in. chip experiments. The importance of shrinking wood chip bed was demonstrated by the reactor’s inferior performance in the upflow versus the downflow mode. A hydrodynamic study should be undertaken to investigate these phenomena. This study can proceed concurrently with work on a tworeactor system that can give a preliminary glimpse at the operation and benefits of a multireactor system.     

Dicobaltoctacarbonyl-alkyne complexes as intermediates in the synthesis of bicyclo[3.3.0]octenones for the synthesis of coriolin and hirsutic acid

Treatment of the readily prepared enzymes 12, 21 and 45 with Co₂(CO) at ca 110° results in high yields (80%) of substituted bicyclo[3.3.0]octenones, that are suitable for straightforward elaboration into coriolin and hirsutic acid precursors. A mechanistic hypothesis to explain the observed stereospecificity is presented.     

Identification of novel sesterterpenes by genome mining of phytopathogenic fungi Phoma and Colletotrichum sp.

Two homologous gene clusters for the biosynthesis of sesterterpenes betaestacins were identified from two phytopathogens, Phoma betae and Colletotrichum orbiculare. Heterologous expression of identified oxidation enzymes with previously-characterized PbTS1 (BtcA_Pb) resulted in the production of seven novel sesterterpenes. Although both strains possessed homologous enzymes, oxidation state of corresponding products were different from each other, suggesting that structural diversification of sesterterpene skeletons might be achieved by these homologous enzymes with different functions.     

Electric Field Assisted Microfluidic Platform for Generation of Tailorable Porous Microbeads as Cell Carriers for Tissue Engineering

Injection of cell‐laden scaffolds in the form of mesoscopic particles directly to the site of treatment is one of the most promising approaches to tissue regeneration. Here, a novel and highly efficient method is presented for preparation of porous microbeads of tailorable dimensions (in the range ≈300–1500 mm) and with a uniform and fully interconnected internal porous texture. The method starts with generation of a monodisperse oil‐in‐water emulsion inside a flow‐focusing microfluidic device. This emulsion is later broken‐up, with the use of electric field, into mesoscopic double droplets, that in turn serve as a template for the porous microbeads. By tuning the amplitude and frequency of the electric pulses, the template droplets and the resulting porous bead scaffolds are precisely produced. Furthermore, a model of pulsed electrodripping is proposed that predicts the size of the template droplets as a function of the applied voltage. To prove the potential of the porous microbeads as cell carries, they are tested with human mesenchymal stem cells and hepatic cells, with their viability and degree of microbead colonization being monitored. Finally, the presented porous microbeads are benchmarked against conventional microparticles with nonhomogenous internal texture, revealing their superior performance.