WEB PISTON: CHOOSING A NEW STRATEGY

Web Piston is a successful enterprise that provides its small business and individual clients with automated web design and web hosting services. Owing to the rapidly changing competitive environment, however, the company’s founder, Ricardo Lasa, feels that a change in strategy is necessary. The case describes the competitive environment for web hosting and outlines four alternative strategies: 1) becoming a “freemium” player, 2) becoming a custom web site developer, 3) creating a marketplace to match web clients and developers, and 4) focusing on developing portals for deployment on social networking sites. The principal objective of the case is to provide a rationale for making the decision, or to offer an alternative strategy. A teaching note may be obtained from Dr. T. Grandon Gill ([email protected]). The case is almost entirely undisguised and was specifically intended to focus on building judgment/evaluation skills in the presence of considerable uncertainty

SiteWit Corporation: SQL or NoSQL that is the Question

This teaching case focuses on a start-up company in the Web analytics and online advertising space, which faces a database scaling challenge. The case covers the rapidly emerging NoSQL database products that can be used to implement very large distributed databases. These are exciting times in the database marketplace, with a flock of new companies offering scalable database systems for the cloud. These products challenge the existing relational database vendors that have come to dominate the market. The case outlines four potential solutions and asks students to make a choice or suggest a different alternative

Microscope System

This project aims to improve upon the current microscope stand for the Olympus compound microscope in the Microcirculation and Vascular Regeneration (MaVR) laboratory in order to minimize angular deflection of the microscope objective with respect to surgical stage

α-MSH regulates intergenic splicing of MC1R and TUBB3 in human melanocytes

Alternative splicing enables higher eukaryotes to increase their repertoire of proteins derived from a restricted number of genes. However, the possibility that functional diversity may also be augmented by splicing between adjacent genes has been largely neglected. Here, we show that the human melanocortin 1 receptor (MC1R) gene, a critical component of the facultative skin pigmentation system, has a highly complex and inefficient poly(A) site which is instrumental in allowing intergenic splicing between this locus and its immediate downstream neighbour tubulin-β-III (TUBB3). These transcripts, which produce two distinct protein isoforms localizing to the plasma membrane and the endoplasmic reticulum, seem to be restricted to humans as no detectable chimeric mRNA could be found in MC1R expressing mouse melanocytes. Significantly, treatment with the MC1R agonist α-MSH or activation of the stress response kinase p38-MAPK, both key molecules associated with ultraviolet radiation dermal insult and subsequent skin tanning, result in a shift in expression from MC1R in favour of chimeric MC1R-TUBB3 isoforms in cultured melanocytes. We propose that these chimeric proteins serve to equip melanocytes with novel cellular phenotypes required as part of the pigmentation response

Stable N-heterocyclic carbene (NHC)-palladium(0) complexes as active catalysts for olefin cyclopropanation reactions with ethyl diazoacetate

The Pd(0) complexes NHCPdLn (NHC = N-heterocyclic carbene ligand; L = styrene for n = 2 or PR3 for n = 1) efficiently catalyze the olefin cyclopropanation using ethyl diazoacetate (EDA) as the carbene source with activities that improve any other previous described catalytic system based on this metal. Mechanistic studies have shown that all those catalyst precursors deliver in solution the same catalytic species (IPr)Pd(sty), a 14e, unsaturated intermediate that further reacts with EDA to afford (IPr)Pd(=CHCO2Et)(sty), from which cyclopropane is formed.We thank Prof. P. J. Pérez (Univ. Huelva) for helpful and constructive comments on these studies. We thank the Ministerio de Ciencia e Innovación (grants CTQ2008–00042BQU and CTQ2011–24502) and the Junta de Andalucía (Proyecto P07-FQM-02794) for financial support. CM thanks the MEC for a research fellowshipWe thank Prof. P.J. Perez (Univ. Huelva) for helpful and constructive comments on these studies. We thank the Ministerio de Ciencia e Innovacion (grants CTQ2008-00042BQU and CTQ2011-24502) and the Junta de Andalucia (Proyecto P07-FQM-02794) for financial support. CM thanks the MEC for a research fellowship

Development Of A Robust Methodology To Obtain And Assess Myogenic Precursor Cells For Their Use In Regenerative Therapies

Peripheral arterial occlusive disease (PAOD) is characterized by buildup of atherosclerotic plaque in peripheral arteries that leads to an occlusion that can interrupt the supply of blood to the peripheral tissue, causing downstream tissue ischemia/hypoxia. PAOD is estimated to affect over 200 million patients worldwide. Current surgical revascularization treatments can be effective in about half of the patient population, leading to a significant number of patients with no treatment options beyond pharmacological intervention and lifestyle modification. The decrease in blood flow downstream of the occlusion leads to increased blood pressure gradient in the microvasculature, specifically in vessels that connect arterial trees (known as collaterals), which will structurally enlarge and increase blood flow to the downstream ischemic/hypoxic tissue. Targeting this process, known as arteriogenesis, can provide a potential treatment option for patients suffering from PAOD by redirecting blood flow around an occluded artery and therefore supplying hypoxic tissue with blood. In order to enhance this process, cellular transplantation has been used but the current cell types explored have not been successful in enhancing arteriogenesis. Myoblasts, proliferative muscle progenitor cells, mediate muscle regeneration, and promote angiogenesis (the growth of new capillaries to supply hypoxic tissue). Preliminary data indicates that myoblasts also promote arteriogenesis in obese mice, making them an attractive therapeutic candidate. However, the methods used in the preliminary studies limited our ability to confirm those findings and characterize the cell therapy candidate. Specifically, we lacked a reproducible and optimized method to isolate myogenic cells and characterize these cells during in vitro culture and after in vivo transplantation. Therefore, the 1st Aim of this study was to optimize the isolation to obtain the highest number possible of satellite cell-yielding myofibers by modification of enzymatic and mechanical digestion of extensor digitorum longus muscle. Modifications to this methodology increased myofiber yield by more than 150%. The 2nd Aim was to optimize the expansion of satellite cell-derived myoblasts by modification of culture media supplements to promote cell expansion while minimizing maturation. bFGF and SB 203580 supplementation improved cell proliferation and prevented myogenic cell maturation during 7-days of in vitro culture. The 3rd Aim was to develop a process for evaluating the quantity and identity of isolated myogenic cells before and after transplantation. This was achieved by implementing an immunofluorescent transcription factor labeling protocol to determine cell identity and a live/dead cell viability assay to determine cell viability and quantity. All 3 aims were integrated into a proof-of-concept pilot study on a hindlimb ischemic BALB/c mouse model. While myoblast transplantation failed to increase collateral arteriogenesis in this model, the process developed in this project provides a reproducible framework for future studies on myoblast-enhanced arteriogenesis. Further research on the effects of myoblast transplantation on arteriogenesis may facilitate the development of new therapies that improve the prognosis of patients with PAOD

Raspberry as a Source for the Development of <i>Drosophila suzukii</i> Attractants: Laboratory and Commercial Polytunnel Trials

Several commercial products and home-made attractants have been developed for monitoring and mass-trapping of the spotted wing drosophila, Drosophila suzukii. Growers in Mexico have adopted an attractant based on a fermenting mixture of raspberry pulp and sucrose, with anecdotally promising results. We compared the capture rates of traps baited with raspberry pulp + sucrose with captures from a range of alternative attractants. Raspberry pulp alone or with sucrose was more attractive than apple cider vinegar (ACV) or SuzukiiTrap and similar to baker's yeast + sucrose in laboratory cage studies. Synthetic raspberry aroma (0.1&#8211;10% concentration), in water or mixed with ACV, did not improve capture rates in the laboratory. Traps baited with raspberry + sucrose or ACV had similar captures of D. suzukii in raspberry or blackberry polytunnels in Michoac&#225;n, Mexico. Raspberry + sucrose baited traps captured significantly higher numbers of other drosophilid species, leading to higher total numbers of captured flies (all species), which may explain why Mexican growers favor the raspberry-based attractant. The commercial products SuzukiiTrap and Z-Kinol had lower captures than ACV in polytunnels, although SuzukiiTrap had the highest selectivity in captures of D. suzukii (81% of flies captured). A two-component trap (2C trap) baited with ACV + ethanol as the drowning solution and raspberry pulp + sucrose or baker&#8217;s yeast + sucrose in a ventilated tube device was markedly more effective than the trap currently used by growers. We conclude that raspberry pulp + sucrose is as effective for the attraction of D. suzukii as ACV under commercial polytunnel conditions. The 2C trap performed better than the transparent cup trap currently used by berry producers in Mexico

L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges

30 décembre 19251925/12/30 (A26,N9146)

Scaling-up fermentation of Escherichia coli for production of recombinant P64k protein from Neisseria meningitidis

Background: P64k is a Neisseria meningitidis high molecular weight protein present in meningococcal vaccine preparations. The lpdA gene, which encodes for this protein, was cloned in Escherichia coli and the P64k recombinant protein was expressed in E. coli K12 GC366 cells under the control of a tryptophan promoter. P64k was expressed as an intracellular soluble protein about 28% of the total cellular protein. Several scale-up criteria of fermentation processes were studied to obtain the recombinant P64k protein at the pilot production scale. Results: The best operational conditions at a larger scale production of P64k recombinant protein were studied and compared using the four following criteria: Constant Reynold's number (Re constant), Constant impeller tip speed (n di constant), Constant power consumption per unit liquid volume (P/V constant) and Constant volumetric oxygen transfer coefficients (KLa/k constant). The highest production of the recombinant protein was achieved based on the constant KLa/k scale-up fermentation criterion, calculating the aeration rate (Q) and the impeller agitation speed (n) by iterative process, keeping constant the KLa/k value from bench scale. The P64k protein total production at the 50 l culture scale was 546 mg l-1 in comparison with the 284 mg l-1 obtained at 1.5 l bench scale. Conclusions: The methodology described herein, for the KLa/k scale-up fermentation criterion, allowed us to obtain the P64k protein at 50 l scale. A fermentation process for the production of P64k protein from N. meningitidis was established, a protein to be used in future vaccine formulations in humans.How to cite: Espinosa R, García J, Narciandi E, et al. Scaling-up fermentation of Escherichia coli for production of recombinant P64k protein from Neisseria meningitidis. Electron J Biotechnol 2018;33. https://doi.org/10.1016/j.ejbt.2018.03.004. Keywords: Escherichia coli, Fermentation process, Fermentation, Gram negative diplococcus, High molecular weight protein, Meningococcal vaccine, Neisseria meningitidis, Obligate human pathogen, Recombinant P64k protein, Scale-up, Tryptophan promote