A General Solution Framework for Component-Commonality Problems

Component commonality - the use of the same version of a component across multiple products - is being increasingly considered as a promising way to offer high external variety while retaining low internal variety in operations. However, increasing commonality has both positive and negative cost effects, so that optimization approaches are required to identify an optimal commonality level. As components influence to a greater or lesser extent nearly every process step along the supply chain, it is not surprising that a multitude of diverging commonality problems is being investigated in literature, each of which are developing a specific algorithm designed for the respective commonality problem being considered. The paper on hand aims at a general framework which is flexible and efficient enough to be applied to a wide range of commonality problems. Such a procedure based on a two-stage graph approach is presented and tested. Finally, flexibility of the procedure is shown by customizing the framework to account for different types of commonality problems.

In disperse solution, “osmotic stress” is a restricted case of preferential interactions

In the practice of “osmotic stress,” the effect of excluded cosolvents on a biochemical equilibrium is interpreted as the number of water molecules participating in the reaction. This action is attributed to lowering of solvent water activity by the cosolvent. This concept of osmotic stress in disperse solution is erroneous: (i) A cosolvent cannot be both excluded and inert, i.e., noninteracting, because exclusion requires a positive free energy change; (ii) a decrease in water activity alone by addition of solute cannot affect an equilibrium when the reacting surface is in contact with the solvent; and (iii) osmotic stress in disperse solution is a restricted case of preferential interactions; the reaction is driven by the free energy of cosolvent exclusion, and the derived number of water molecules is solely a measure of the mutual perturbations of the chemical potentials of the cosolvent and the protein.

Solution structure and peptide binding studies of the C-terminal Src homology 3-like domain of the diphtheria toxin repressor protein

The diphtheria toxin repressor (DtxR) is the best-characterized member of a family of homologous proteins that regulate iron uptake and virulence gene expression in the Gram-positive bacteria. DtxR contains two domains that are separated by a short, unstructured linker. The N-terminal domain is structurally well-defined and is responsible for Fe2+ binding, dimerization, and DNA binding. The C-terminal domain adopts a fold similar to eukaryotic Src homology 3 domains, but the functional role of the C-terminal domain in repressor activity is unknown. The solution structure of the C-terminal domain, consisting of residues N130-L226 plus a 13-residue N-terminal extension, has been determined by using NMR spectroscopy. Residues before A147 are highly mobile and adopt a random coil conformation, but residues A147-L226 form a single structured domain consisting of five β-strands and three helices arranged into a partially orthogonal, two-sheet β-barrel, similar to the structure observed in the crystalline Co2+ complex of full-length DtxR. Chemical shift perturbation studies demonstrate that a proline-rich peptide corresponding to residues R125-G139 of intact DtxR binds to the C-terminal domain in a pocket formed by residues in β-strands 2, 3, and 5, and helix 3. Binding of the proline-rich peptide by the C-terminal domain of DtxR presents an example of peptide binding by a prokaryotic Src homology 3-like protein. The results of this study, combined with previous x-ray studies of intact DtxR, provide insights into a possible biological function of the C-terminal domain in regulating repressor activity.

Dissidents with an innovation cause? Non-institutionalized actors’ online social knowledge sharing, solution-finding tensions and technology management innovation

Purpose – Traditionally, most studies focus on institutionalized management-driven actors to understand technology management innovation. The purpose of this paper is to argue that there is a need for research to study the nature and role of dissident non-institutionalized actors’ (i.e. outsourced web designers and rapid application software developers). The authors propose that through online social knowledge sharing, non-institutionalized actors’ solution-finding tensions enable technology management innovation. Design/methodology/approach – A synthesis of the literature and an analysis of the data (21 interviews) provided insights in three areas of solution-finding tensions enabling management innovation. The authors frame the analysis on the peripherally deviant work and the nature of the ways that dissident non-institutionalized actors deviate from their clients (understood as the firm) original contracted objectives. Findings – The findings provide insights into the productive role of solution-finding tensions in enabling opportunities for management service innovation. Furthermore, deviant practices that leverage non-institutionalized actors’ online social knowledge to fulfill customers’ requirements are not interpreted negatively, but as a positive willingness to proactively explore alternative paths. Research limitations/implications – The findings demonstrate the importance of dissident non-institutionalized actors in technology management innovation. However, this work is based on a single country (USA) and additional research is needed to validate and generalize the findings in other cultural and institutional settings. Originality/value – This paper provides new insights into the perceptions of dissident non-institutionalized actors in the practice of IT managerial decision making. The work departs from, but also extends, the previous literature, demonstrating that peripherally deviant work in solution-finding practice creates tensions, enabling management innovation between IT providers and users.

Disinfection of clinical materials using photo-activated tolonium chloride solution

Photo-activated disinfection is beginning to be used in dental surgery to treat deep seated bacterial infection. It works by combining a photosensitiser and light of a specific frequency to generate singlet oxygen which is toxic to many types of bacteria. It is suggested that this technique could be used as a means to help treat infection more generally. To do so, it needs to work with materials and geometries exhibiting different physical and optical characteristics to teeth. In these trials, samples of stainless steel and polymethylmethacrylate were exposed to bacterial solutions of Staphylococcus aureus and Staphylococcus epidermis. These were treated with tolonium chloride-based photo-activated disinfection regimes showing positive results with typically 4 log10 reductions in colony forming units. Tests were also carried out using slotted samples to represent geometric features which might be found on implants. These tests, showed disinfectant effect however to a much lesser degree. © 2011 Inderscience Enterprises Ltd.

Az egyensúlyi ráták unicitása és a bérráta pozitivitása a Neumann-modell általánosításaiban (Uniqueness of equilibrium rates and the positive value of the wage rate in generalizations from the Neumann model)

Cikkünk arról a paradox jelenségről szól, hogy a fogyasztást explicit módon megjelenítő Neumann-modell egyensúlyi megoldásaiban a munkabért meghatározó létszükségleti termékek ára esetenként nulla lehet, és emiatt a reálbér egyensúlyi értéke is nulla lesz. Ez a jelenség mindig bekövetkezik az olyan dekomponálható gazdaságok esetén, amelyekben eltérő növekedési és profitrátájú, alternatív egyensúlyi megoldások léteznek. A jelenség sokkal áttekinthetőbb formában tárgyalható a modell Leontief-eljárásra épülő egyszerűbb változatában is, amit ki is használunk. Megmutatjuk, hogy a legnagyobbnál alacsonyabb szintű növekedési tényezőjű megoldások közgazdasági szempontból értelmetlenek, és így érdektelenek. Ezzel voltaképpen egyrészt azt mutatjuk meg, hogy Neumann kiváló intuíciója jól működött, amikor ragaszkodott modellje egyértelmű megoldásához, másrészt pedig azt is, hogy ehhez nincs szükség a gazdaság dekomponálhatóságának feltételezésére. A vizsgált téma szorosan kapcsolódik az általános profitráta meghatározásának - Sraffa által modern formába öntött - Ricardo-féle elemzéséhez, illetve a neoklasszikus növekedéselmélet nevezetes bér-profit, illetve felhalmozás-fogyasztás átváltási határgörbéihez, ami jelzi a téma elméleti és elmélettörténeti érdekességét is. / === / In the Marx-Neumann version of the Neumann model introduced by Morishima, the use of commodities is split between production and consumption, and wages are determined as the cost of necessary consumption. In such a version it may occur that the equilibrium prices of all goods necessary for consumption are zero, so that the equilibrium wage rate becomes zero too. In fact such a paradoxical case will always arise when the economy is decomposable and the equilibrium not unique in terms of growth and interest rate. It can be shown that a zero equilibrium wage rate will appear in all equilibrium solutions where growth and interest rate are less than maximal. This is another proof of Neumann's genius and intuition, for he arrived at the uniqueness of equilibrium via an assumption that implied that the economy was indecomposable, a condition relaxed later by Kemeny, Morgenstern and Thompson. This situation occurs also in similar models based on Leontief technology and such versions of the Marx-Neumann model make the roots of the problem more apparent. Analysis of them also yields an interesting corollary to Ricardo's corn rate of profit: the real cause of the awkwardness is bad specification of the model: luxury commodities are introduced without there being a final demand for them, and production of them becomes a waste of resources. Bad model specification shows up as a consumption coefficient incompatible with the given technology in the more general model with joint production and technological choice. For the paradoxical situation implies the level of consumption could be raised and/or the intensity of labour diminished without lowering the equilibrium rate of the growth and interest. This entails wasteful use of resources and indicates again that the equilibrium conditions are improperly specified. It is shown that the conditions for equilibrium can and should be redefined for the Marx-Neumann model without assuming an indecomposable economy, in a way that ensures the existence of an equilibrium unique in terms of the growth and interest rate coupled with a positive value for the wage rate, so confirming Neumann's intuition. The proposed solution relates closely to findings of Bromek in a paper correcting Morishima's generalization of wage/profit and consumption/investment frontiers.

The solution-seeking behavior of small Hungarian enterprises between 2006 and 2010

This paper describes the results of an investigation into the finance-related innovative ability of Hungarian micro, small and medium sized enterprises (SMEs) by using two datasets (from 2006 and 2010). The author explored SMEs’ levels of openness to new financial solutions and identified features which influence their innovative solution-seeking behavior. Additionally, changes in innovation between 2006 and 2010 were analyzed according to the SME sector and whether there is a correlation between having an active solution seeking attitude and business performance was examined. The findings show that shared/multiple ownership in businesses (having interests in different enterprises simultaneously) has a significant positive effect on flexibility and innovative ability. However, the size of the business, industrial sector, type of ownership and market of the SME also have some effect. Furthermore, the hypothesis that an active solution-seeking attitude increases after-tax performance per employee was confirmed.

Class Size Reduction for the State of Florida: Is This the Solution for a Better Education?

Smaller class sizes have a positive impact on student achievement but Florida struggles with the problem of how to achieve smaller classes. Through a review of the literature, this paper discusses some of the programs currently used across the US, with the focus on Florida. Conclusions and implications are presented.

Le vieillissement du personnel enseignant au Québec : une approche systémique de solution de problèmes

Le vieillissement du personnel enseignant se manifeste à la grandeur du Québec. Partout, dans toutes les commissions scolaires, on parle du besoin de se renouveler, d'avoir du "sang neuf". Pourtant, on oublie une réalité cruciale. Ces hommes et ces femmes qui ont donné 20, 30, parfois 40 ans de leur vie à l'enseignement, ont atteint une maturité incontestable. Ces personnes ont tout un bagage de connaissances et d'expériences à apporter aux enseignants débutants. L'envers de la médaille, c'est aussi le fait que l'absence de jeunes enseignants se fait cruellement sentir dans nos écoles. Les étudiants manifestent clairement le besoin de voir autres choses que des têtes blanches... Ils ont besoin de grands-parents, bien sûr, mais aussi de parents et plus que tout, de grands frères et de grandes soeurs qui ont le goût d'être avec eux et de vivre avec eux des expériences enrichissantes tous les jours, et non pas uniquement de temps en temps... Oui, le personnel enseignant du Québec a pris de l'âge (moyenne d'âge: 48 ans pour les enseignants(tes) du primaire et du secondaire). Peut-on espérer des stratégies qui géreraient ce vieillissement de façon positive? Ce travail veut souligner qu'avec le vieillissement vient aussi l'expérience, les connaissances et la maturité. Il voudrait de plus explorer des façons de vivre le vieillissement de façon à ce que chacun(e) puisse donner le meilleur de soi-même. Il voudrait surtout apporter des pistes pour que tous, jeunes et moins jeunes, trouvent leur vrai place dans l'organisation scolaire.

POSITIVE FILTERED P_N METHOD FOR LINEAR TRANSPORT EQUATIONS AND THE ASSOCIATED OPTIMIZATION ALGORITHM

We propose a positive, accurate moment closure for linear kinetic transport equations based on a filtered spherical harmonic (FP_N) expansion in the angular variable. The FP_N moment equations are accurate approximations to linear kinetic equations, but they are known to suffer from the occurrence of unphysical, negative particle concentrations. The new positive filtered P_N (FP_N+) closure is developed to address this issue. The FP_N+ closure approximates the kinetic distribution by a spherical harmonic expansion that is non-negative on a finite, predetermined set of quadrature points. With an appropriate numerical PDE solver, the FP_N+ closure generates particle concentrations that are guaranteed to be non-negative. Under an additional, mild regularity assumption, we prove that as the moment order tends to infinity, the FP_N+ approximation converges, in the L2 sense, at the same rate as the FP_N approximation; numerical tests suggest that this assumption may not be necessary. By numerical experiments on the challenging line source benchmark problem, we confirm that the FP_N+ method indeed produces accurate and non-negative solutions. To apply the FP_N+ closure on problems at large temporal-spatial scales, we develop a positive asymptotic preserving (AP) numerical PDE solver. We prove that the propose AP scheme maintains stability and accuracy with standard mesh sizes at large temporal-spatial scales, while, for generic numerical schemes, excessive refinements on temporal-spatial meshes are required. We also show that the proposed scheme preserves positivity of the particle concentration, under some time step restriction. Numerical results confirm that the proposed AP scheme is capable for solving linear transport equations at large temporal-spatial scales, for which a generic scheme could fail. Constrained optimization problems are involved in the formulation of the FP_N+ closure to enforce non-negativity of the FP_N+ approximation on the set of quadrature points. These optimization problems can be written as strictly convex quadratic programs (CQPs) with a large number of inequality constraints. To efficiently solve the CQPs, we propose a constraint-reduced variant of a Mehrotra-predictor-corrector algorithm, with a novel constraint selection rule. We prove that, under appropriate assumptions, the proposed optimization algorithm converges globally to the solution at a locally q-quadratic rate. We test the algorithm on randomly generated problems, and the numerical results indicate that the combination of the proposed algorithm and the constraint selection rule outperforms other compared constraint-reduced algorithms, especially for problems with many more inequality constraints than variables.

On a Limit of Perturbed Conservation Laws with Diffusion and Non-Positive Dispersion

We consider a conservation law perturbed by a linear diffusion and a general form of non-positive dispersion. We prove the convergence of the corresponding solution to the entropy weak solution of the hyperbolic conservation law.

Comparison Of The Solution Of Histidine-tryptophan-alfacetoglutarate With Histidine-tryptophan-glutamate As Cardioplegic Agents In Isolated Rat Hearts: An Immunohistochemical Study.

Cardiac arrest during heart surgery is a common procedure and allows the surgeon to perform surgical procedures in an environment free of blood and movement. Using a model of isolated rat heart, the authors compare a new cardioplegic solution containing histidine-tryptophan-glutamate (group 2) with the histidine-tryptophan-alphacetoglutarate (group 1) routinely used by some cardiac surgeons. To assess caspase, IL-8 and KI-67 in isolated rat hearts using immunohistochemistry. 20 Wistar male rats were anesthetized and heparinized. The chest was opened, cardioctomy was performed and 40 ml/kg of the appropriate cardioplegic solution was infused. The hearts were kept for 2 hours at 4ºC in the same solution, and thereafter, placed in the Langendorff apparatus for 30 minutes with Ringer-Locke solution. Immunohistochemistry analysis of caspase, IL-8, and KI-67 were performed. The concentration of caspase was lower in group 2 and Ki-67 was higher in group 2, both P<0.05. There was no statistical difference between the values of IL-8 between the groups. Histidine-tryptophan-glutamate solution was better than histidine-tryptophan-alphacetoglutarate solution because it reduced caspase (apoptosis), increased KI-67 (cell proliferation), and showed no difference in IL-8 levels compared to group 1. This suggests that the histidine-tryptophan-glutamate solution was more efficient than the histidine-tryptophan-alphacetoglutarate for the preservation of hearts of rat cardiomyocytes.

Islet Neogenesis-associated Protein (ingap): The Role Of Its Endogenous Production As A Positive Modulator Of Insulin Secretion.

Islet neogenesis-associated protein (INGAP) is a peptide found in pancreatic exocrine-, duct- and islet- non-β-cells from normal hamsters. Its increase induced by either its exogenous administration or by the overexpression of its gene enhances β-cell secretory function and increases β-cell mass by a combination of stimulation of cell replication and islet neogenesis and reduction of β-cell apoptosis. We studied the potential modulatory role of endogenous INGAP in insulin secretion using two different experimental approaches. Hamster islets transfected with INGAP-small interfering RNA (INGAP-siRNA) were used to study glucose-stimulated insulin secretion (GSIS). In parallel, freshly isolated islets were incubated with high glucose and the same concentration of either a specific anti-INGAP rabbit serum or normal rabbit serum. INGAP-siRNA transfected islets reduced their INGAP mRNA and protein content by 35.1% and 47.2%, respectively whereas GSIS decreased by 25.8%. GSIS by transfected islets attained levels comparable to those recorded in control islets when INGAP pentadecapeptide (INGAP-PP) was added to the culture medium. INGAP antibody in the medium decreased significantly GSIS in a dose-dependent manner. These results indicate that endogenous INGAP plays a physiological positive modulatory role in insulin secretion, supporting its possible use in the treatment of prediabetes and Type 2 diabetes.

Remediation Of 17-α-ethinylestradiol Aqueous Solution By Photocatalysis And Electrochemically-assisted Photocatalysis Using Tio2 And Tio2/wo3 Electrodes Irradiated By A Solar Simulator.

TiO2 and TiO2/WO3 electrodes, irradiated by a solar simulator in configurations for heterogeneous photocatalysis (HP) and electrochemically-assisted HP (EHP), were used to remediate aqueous solutions containing 10 mg L(-1) (34 μmol L(-1)) of 17-α-ethinylestradiol (EE2), active component of most oral contraceptives. The photocatalysts consisted of 4.5 μm thick porous films of TiO2 and TiO2/WO3 (molar ratio W/Ti of 12%) deposited on transparent electrodes from aqueous suspensions of TiO2 particles and WO3 precursors, followed by thermal treatment at 450 (°)C. First, an energy diagram was organized with photoelectrochemical and UV-Vis absorption spectroscopy data and revealed that EE2 could be directly oxidized by the photogenerated holes at the semiconductor surfaces, considering the relative HOMO level for EE2 and the semiconductor valence band edges. Also, for the irradiated hybrid photocatalyst, electrons in TiO2 should be transferred to WO3 conduction band, while holes move toward TiO2 valence band, improving charge separation. The remediated EE2 solutions were analyzed by fluorescence, HPLC and total organic carbon measurements. As expected from the energy diagram, both photocatalysts promoted the EE2 oxidation in HP configuration; after 4 h, the EE2 concentration decayed to 6.2 mg L(-1) (35% of EE2 removal) with irradiated TiO2 while TiO2/WO3 electrode resulted in 45% EE2 removal. A higher performance was achieved in EHP systems, when a Pt wire was introduced as a counter-electrode and the photoelectrodes were biased at +0.7 V; then, the EE2 removal corresponded to 48 and 54% for the TiO2 and TiO2/WO3, respectively. The hybrid TiO2/WO3, when compared to TiO2 electrode, exhibited enhanced sunlight harvesting and improved separation of photogenerated charge carriers, resulting in higher performance for removing this contaminant of emerging concern from aqueous solution.

Granulocyte Colony-stimulating Factor (g-csf) Positive Effects On Muscle Fiber Degeneration And Gait Recovery After Nerve Lesion In Mdx Mice.

G-CSF has been shown to decrease inflammatory processes and to act positively on the process of peripheral nerve regeneration during the course of muscular dystrophy. The aims of this study were to investigate the effects of treatment of G-CSF during sciatic nerve regeneration and histological analysis in the soleus muscle in MDX mice. Six-week-old male MDX mice underwent left sciatic nerve crush and were G-CSF treated at 7 days prior to and 21 days after crush. Ten and twenty-one days after surgery, the mice were euthanized, and the sciatic nerves were processed for immunohistochemistry (anti-p75(NTR) and anti-neurofilament) and transmission electron microscopy. The soleus muscles were dissected out and processed for H&E staining and subsequent morphologic analysis. Motor function analyses were performed at 7 days prior to and 21 days after sciatic crush using the CatWalk system and the sciatic nerve index. Both groups treated with G-CSF showed increased p75(NTR) and neurofilament expression after sciatic crush. G-CSF treatment decreased the number of degenerated and regenerated muscle fibers, thereby increasing the number of normal muscle fibers. The reduction in p75(NTR) and neurofilament indicates a decreased regenerative capacity in MDX mice following a lesion to a peripheral nerve. The reduction in motor function in the crushed group compared with the control groups may reflect the cycles of muscle degeneration/regeneration that occur postnatally. Thus, G-CSF treatment increases motor function in MDX mice. Nevertheless, the decrease in baseline motor function in these mice is not reversed completely by G-CSF.