817 research outputs found

    Toward Strategy Implementation Success: An Empirical Study of the Role of Senior-Level Leaders in the Nevada Gaming Industry

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    The study is an investigation of the relationship between effective leadership behavior and successful strategy implementation in the Nevada casino industry. The study\u27s findings mostly agree with earlier research on the concept of strategy implementation and reaffirm the role that strategic consensus plays in the strategy implementation process. The study also reinforces findings that frequent communication up and down the organization structure enhances strategic consensus through the fostering of shared attitudes and values. In addition, it reaffirms the concept that an organization which ties rewards to the success of the strategy employed is rewarded with higher levels of organizational performance and concludes that strategy implementation plans must be clearly developed, indicating particular tasks for individuals, with clear-cut time frames, and identifying the people responsible for task completion

    Are the mission statements of two large U.S. public business university systems inspiring? You decide!

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    Mission statements have become increasingly important for the accreditation of business universities and colleges. Thus, understanding similarities and differences in the content of business school mission statements is especially timely. The mission statement is also the first component of the strategic management process. It provides the framework or context within which strategies are formulated. This descriptive/informative study aims to present a background that describes and explains institutional mission statements and removes the so-called uncertainty encompassing the foci while preserving exceptional quality—a necessary quality for a compelling mission statement. We question whether all California State University (CSU) and The State University of New York (SUNY) business colleges/schools have developed enduring and inspiring mission statements for their employees and students? While no specific rule regarding length exists, we examined the word count length of these two school system mission statements. Institutions must not make their mission statements too long or too short, or they will risk losing focus and missing essential elements to guide their organization. The mission statement must be long enough to achieve its purpose. Based on our findings, we recommend that all CSU and SUNY campuses embrace a more straightforward, easy-to-understand, hard-hitting, lasting, and inspirational mission statement for their business colleges/schools, one directly relevant to faculty, staff, students, and their families

    Maintaining The Integrity Of Turnover Measurements When There Are Layoffs

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    Bonuses for improvements in employee retention rates should be calculated on the actual savings due to fewer terminations and reduced replacement costs. Permanent layoffs and hiring freezes distort the turnover rate and make the normal bonus calculations invalid. A new method for calculating a manager’s bonus for reducing the turnover rate is illustrated. It isolates the number of terminations due to changes in the size of the workforce from the terminations due to the improved retention rate. The size of the savings in terminations due to the improved retention rate can be accurately measured in situations where hiring freezes negate normal calculations

    Cell visco-elasticity measured with AFM and optical trapping at sub-micrometer deformations

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    The measurement of the elastic properties of cells is widely used as an indicator for cellular changes during differentiation, upon drug treatment, or resulting from the interaction with the supporting matrix. Elasticity is routinely quantified by indenting the cell with a probe of an AFM while applying nano-Newton forces. Because the resulting deformations are in the micrometer range, the measurements will be affected by the finite thickness of the cell, viscous effects and even cell damage induced by the experiment itself. Here, we have analyzed the response of single 3T3 fibroblasts that were indented with a micrometer-sized bead attached to an AFM cantilever at forces from 30–600 pN, resulting in indentations ranging from 0.2 to 1.2 micrometer. To investigate the cellular response at lower forces up to 10 pN, we developed an optical trap to indent the cell in vertical direction, normal to the plane of the coverslip. Deformations of up to two hundred nanometers achieved at forces of up to 30 pN showed a reversible, thus truly elastic response that was independent on the rate of deformation. We found that at such small deformations, the elastic modulus of 100 Pa is largely determined by the presence of the actin cortex. At higher indentations, viscous effects led to an increase of the apparent elastic modulus. This viscous contribution that followed a weak power law, increased at larger cell indentations. Both AFM and optical trapping indentation experiments give consistent results for the cell elasticity. Optical trapping has the benefit of a lower force noise, which allows a more accurate determination of the absolute indentation. The combination of both techniques allows the investigation of single cells at small and large indentations and enables the separation of their viscous and elastic components

    Infinitely many states and stochastic symmetry in a Gaussian Potts-Hopfield model

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    We study a Gaussian Potts-Hopfield model. Whereas for Ising spins and two disorder variables per site the chaotic pair scenario is realized, we find that for q-state Potts spins [{q(q-1} \over 2]-tuples occur. Beyond the breaking of a continous stochastic symmetry, we study the fluctuations and obtain the Newman-Stein metastate description for our model.Comment: latex, 17 page

    A numerical comparison of theories of violent relaxation

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    Using N-body simulations with a large set of massless test particles we compare the predictions of two theories of violent relaxation, the well known Lynden-Bell theory and the more recent theory by Nakamura. We derive ``weaken'' versions of both theories in which we use the whole equilibrium coarse-grained distribution function as a constraint instead of the total energy constraint. We use these weaken theories to construct expressions for the conditional probability Ki(τ)K_i(\tau) that a test particle initially at the phase-space coordinate τ\tau would end-up in the ii'th macro-cell at equilibrium. We show that the logarithm of the ratio Rij(τ)≡Ki(τ)/Kj(τ)R_{ij}(\tau) \equiv K_i(\tau)/K_j(\tau) is directly proportional to the initial phase-space density f0(τ)f_0(\tau) for the Lynden-Bell theory and inversely proportional to f0(τ)f_0(\tau) for the Nakamura theory. We then measure Rij(τ)R_{ij}(\tau) using a set of N-body simulations of a system undergoing a gravitational collapse to check the validity of the two theories of violent relaxation. We find that both theories are at odds with the numerical results, qualitatively and quantitatively.Comment: Replaced with a revised version, which is now accepted to MNRAS. LaTeX, 12 pages, 6 figure

    Tensions experienced by teachers when participating in a professional learning community

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    Contains fulltext : 199560.pdf (publisher's version ) (Open Access)29 november 201

    Identification and functional characterization of novel xylose transporters from the cell factories Aspergillus niger and Trichoderma reesei

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    Background: Global climate change and fossil fuels limitations have boosted the demand for robust and efficient microbial factories for the manufacturing of bio-based products from renewable feedstocks. In this regard, efforts have been done to enhance the enzyme-secreting ability of lignocellulose-degrading fungi, aiming to improve protein yields while taking advantage of their ability to use lignocellulosic feedstocks. Access to sugars in complex polysaccharides depends not only on their release by specific hydrolytic enzymes, but also on the presence of transporters capable of effectively transporting the constituent sugars into the cell. This study aims to identify and characterize xylose transporters from Aspergillus Niger and Trichoderma reesei, two fungi that have been industrially exploited for decades for the production of lignocellulose-degrading hydrolytic enzymes. Results: A hidden Markov model for the identification of xylose transporters was developed and used to analyze the A. Niger and T. reesei in silico proteomes, yielding a list of candidate xylose transporters. From this list, three A. Niger (XltA, XltB and XltC) and three T. reesei (Str1, Str2 and Str3) transporters were selected, functionally validated and biochemically characterized through their expression in a Saccharomyces cerevisiae hexose transport null mutant, engineered to be able to metabolize xylose but unable to transport this sugar. All six transporters were able to support growth of the engineered yeast on xylose but varied in affinities and efficiencies in the uptake of the pentose. Amino acid sequence analysis of the selected transporters showed the presence of specific residues and motifs recently associated to xylose transporters. Transcriptional analysis of A. Niger and T. reesei showed that XltA and Str1 were specifically induced by xylose and dependent on the XlnR/Xyr1 regulators, signifying a biological role for these transporters in xylose utilization. Conclusions: This study revealed the existence of a variety of xylose transporters in the cell factories A. Niger and T. reesei. The particular substrate specificity and biochemical properties displayed by A. Niger XltA and XltB suggested a possible biological role for these transporters in xylose uptake. New insights were also gained into the molecular mechanisms regulating the pentose utilization, at inducer uptake level, in these fungi. Analysis of the A. Niger and T. reesei predicted transportome with the newly developed hidden Markov model showed to be an efficient approach for the identification of new xylose transporting proteins.</p

    Aspergillus niger citrate exporter revealed by comparison of two alternative citrate producing conditions

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    Currently, there is no consensus regarding the mechanism underlying Aspergillus niger citrate biosynthesis and secretion. We hypothesise that depending on the experimental setup, extracellular citrate accumulation can have fundamentally different underlying transcriptomic landscapes. We show that varying the amount and type of supplement of an arginine auxotrophic A. niger strain results in transcriptional down-regulation of citrate metabolising enzymes in the condition in which more citrate is accumulated extracellularly. This contrasts with the transcriptional adaptations when increased citrate production is triggered by iron limitation. By combining gene expression data obtained from these two very distinct experimental setups with hidden Markov models and transporter homology approaches, we were able to compile a shortlist of the most likely citrate transporter candidates. Two candidates (An17g01710 and An09g06720m.01) were heterologously expressed in the yeast Saccharomyces cerevisiae, and one of the resultant mutants showed the ability to secrete citrate. Our findings provide steps in untangling the complex interplay of different mechanisms underlying A. niger citrate accumulation, and we demonstrate how a comparative transcriptomics approach complemented with further bioinformatics analyses can be used to pinpoint a fungal citrate exporter

    The diacylglycerol kinase α/Atypical PKC/β1 integrin pathway in SDF-1α mammary carcinoma invasiveness

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    Diacylglycerol kinase α (DGKα), by phosphorylating diacylglycerol into phosphatidic acid, provides a key signal driving cell migration and matrix invasion. We previously demonstrated that in epithelial cells activation of DGKα activity promotes cytoskeletal remodeling and matrix invasion by recruiting atypical PKC at ruffling sites and by promoting RCP-mediated recycling of α5β1 integrin to the tip of pseudopods. In here we investigate the signaling pathway by which DGKα mediates SDF-1α-induced matrix invasion of MDA-MB-231 invasive breast carcinoma cells. Indeed we showed that, following SDF-1α stimulation, DGKα is activated and localized at cell protrusion, thus promoting their elongation and mediating SDF-1α induced MMP-9 metalloproteinase secretion and matrix invasion. Phosphatidic acid generated by DGKα promotes localization at cell protrusions of atypical PKCs which play an essential role downstream of DGKα by promoting Rac-mediated protrusion elongation and localized recruitment of β1 integrin and MMP-9. We finally demonstrate that activation of DGKα, atypical PKCs signaling and β1 integrin are all essential for MDA-MB-231 invasiveness. These data indicates the existence of a SDF-1α induced DGKα - atypical PKC - β1 integrin signaling pathway, which is essential for matrix invasion of carcinoma cells
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