Different Conditions for the Modification of Polycaprolactone Films with L-Arginine

Poly-ε-caprolactone (PCL) is a biodegradable polymer used in regenerative medicine. Mesenchymal stem cells (MSCs) play an important role in the regeneration of different tissues. The hydrophobicity and neutrality of a PCL surface reduce MSCs’ adhesion and proliferation. In this study, PCL films were treated with arginine to improve surface hydrophilicity. The influences of arginine concentration, temperature, and solvent on PCL surface properties were investigated. PCL films treated with a solution of arginine in isopropyl alcohol were found to have the maximum number of amino groups. The greatest number of cells, 2 h after seeding, adhered to such films. It was shown that amino groups affect the interaction of cells with a modified surface and the hydrolysis reaction after treatment with isopropyl alcohol promotes the formation of adhesive focal contacts. Hence, our results illustrate that functional groups on the PCL surface after arginine solution treatment regulate MSC adhesion and focal contact formation.

Formation of Aberrant Myotubes by Myoblasts Lacking Myosin VI Is Associated with Alterations in the Cytoskeleton Organization, Myoblast Adhesion and Fusion

We have previously postulated that unconventional myosin VI (MVI) could be involved in myoblast differentiation. Here, we addressed the mechanism(s) of its involvement using primary myoblast culture derived from the hindlimb muscles of Snell’s waltzer mice, the natural MVI knockouts (MVI-KO). We observed that MVI-KO myotubes were formed faster than control heterozygous myoblasts (MVI-WT), with a three-fold increase in the number of myosac-like myotubes with centrally positioned nuclei. There were also changes in the levels of the myogenic transcription factors Pax7, MyoD and myogenin. This was accompanied by changes in the actin cytoskeleton and adhesive structure organization. We observed significant decreases in the levels of proteins involved in focal contact formation, such as talin and focal adhesion kinase (FAK). Interestingly, the levels of proteins involved in intercellular communication, M-cadherin and drebrin, were also affected. Furthermore, time-dependent alterations in the levels of the key proteins for myoblast membrane fusion, myomaker and myomerger, without effect on their cellular localization, were observed. Our data indicate that in the absence of MVI, the mechanisms controlling cytoskeleton organization, as well as myoblast adhesion and fusion, are dysregulated, leading to the formation of aberrant myotubes.

Driving Mobile Accounts Sales: Strategic Imperative for Telenor Pakistan

In October 2013, Mahboob Ali Shah Manager Financial Services Planning Telenor Pakistan (TP) needed to make decisions on the future of Mobile Accounts Sales officers (MASOs). TP had two businesses, i.e., GSM (96 per cent revenue contribution in TP 2012 sales) and financial services offering (4 per cent revenue contribution in TP 2012 sales) under the brand name of EasyPaisa. TP launched EasyPaisa in 2009 with a view to reach out to the unbanked segment (60 million people). By 2012, EasyPaisa had a brand awareness of 80 per cent with the largest footprint of 36,000 EasyPaisa shops. Mobile accounts (MAs) were introduced in 2010 which could be operated only by Telenor sim and; hence, offered a great opportunity for TP to attract and retain customers for continual usage of its complete offerings. TP developed an elaborate go to market strategy (direct as well as indirect) to reach its customers effectively. Territory Sales Supervisors (TSS) has been the focal contact point between TP and their franchises since the launch of GSM services in 2005; however, as TP increased their offerings in the realm of financial services and offered diverse services such as MAs it became difficult for TSS to focus on MA and other financial services products whereas ironically MA contributed only (5 per cent) in KPI of TSS. At the same time, selling of MAs required different selling process as opposed to selling GSM services to franchisees and subsequently to retailers. Due to this change in the selling process, highly successful TSS had not been able to achieve sales targets for MA. In order to achieve corporate objectives for MA sales, Mahboob needed to make a choice from among different possible options for MASO’s expansion to achieve this year’s target of 350,000 MA, out of which until now he could achieve only 224,000.

Cell motion as a stochastic process controlled by focal contacts dynamics

SUMMARYDirected cell motion is essential in physiological and pathological processes such as morphogenesis, wound healing and cancer spreading. Chemotaxis has often been proposed as the driving mechanism, even though evidence of long-range gradients is often lacking in vivo. By patterning adhesive regions in space, we control cell shape and the associated potential to move along one direction in another mode of migration coined ratchetaxis. We report that focal contacts distributions collectively dictate cell directionality, and bias is non-linearly increased by gap distance between adhesive regions. Focal contact dynamics on micro-patterns allow to integrate these phenomena in a consistent model where each focal contact can be translated into a force with known amplitude and direction, leading to quantitative predictions for cell motion in every condition. Altogether, our study shows how local and minutes timescale dynamics of focal adhesions and their distribution lead to long term cellular motion with simple geometric rules.

Optimization of synchronizer cone angle with regard to manufacturing tolerances of cone roundness and cone angle

The effects of manufacturing tolerances on the maximum focal temperature has been investigated by transient thermomechanical simulations. Both relative cone angle and cone out-of-roundness for molybdenum and carbon fibre reinforced polymer synchronizers were evaluated. It was shown that cone out-of-roundness significantly increases the focal contact temperature for that specific cone but has little impact on the opposing cone. Two populations of measured synchronizers were evaluated, and it was shown that the maximum focal surface temperature can be decreased in almost all tolerance cases by introducing a relative angle between the cones.