1,037 research outputs found

    Sequencing BPS spectra

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    Shaking Stakeholders to Leverage a Firm’s Unique Capacity in Issue Networks

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    Firms are often seen to react to stakeholder pressure. However, if one changes the unit of analysis to a social or environmental issue, a firm emerges as a key influencer in mobilizing and connecting other stakeholders. For a variety of reasons, including the firm’s raison d’etre of creating value, a firm may be a critical leader or lynchpin in a movement, especially where it bridges gaps in a previously disconnected network. Two previously underappreciated aspects of stakeholder ties are highlighted in this paper. First, the firm can be seen as shaking otherwise latent stakeholders out of complacency, inasmuch as a firm informs and stimulates concerns, emotions, and actions among stakeholders in relation to a particular issue. Second, the firm can be seen as shaking-up the connections between stakeholders, catalyzing new contacts and relationships within an issue network

    Wall-crossing, open BPS counting and matrix models

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    We consider wall-crossing phenomena associated to the counting of D2-branes attached to D4-branes wrapping lagrangian cycles in Calabi-Yau manifolds, both from M-theory and matrix model perspective. Firstly, from M-theory viewpoint, we review that open BPS generating functions in various chambers are given by a restriction of the modulus square of the open topological string partition functions. Secondly, we show that these BPS generating functions can be identified with integrands of matrix models, which naturally arise in the free fermion formulation of corresponding crystal models. A parameter specifying a choice of an open BPS chamber has a natural, geometric interpretation in the crystal model. These results extend previously known relations between open topological string amplitudes and matrix models to include chamber dependence.Comment: 25 pages, 8 figures, published versio

    Shake Your Stakeholder: Firms Leading Engagement to Cocreate Sustainable Value

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    © The Author(s) 2017. While most extant scholarship has focused on how stakeholders influence firms, we propose that firms play a critical role in “shaking” stakeholders. Shaking stakeholders means to proactively initiate cooperation with those affected by a firm to alter awareness, behavior, and networks so as to catalyze change in society and the marketplace to reward cocreated innovations in core operations of the firm that improve social and environmental impacts. Two previously underappreciated aspects of stakeholder relations are highlighted. First, the firm can be the entity that leads engagement that shakes stakeholders out of complacency. Second, firms can catalyze collaborative relationships to cocreate sustainable value that is shared with stakeholders. We offer several cases to illustrate this strategy. While stakeholder shaking may be useful in any business environment, global ecological crises, societal problems, and governance failures heighten the need for firms to take action to bring about profound and systemic changes

    The Extravehicular Suit Impact Load Attenuation Study for Use in Astronaut Bone Fracture Prediction

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    The NASA Integrated Medical Model (IMM) assesses the risk, including likelihood and impact of occurrence, of all credible in-flight medical conditions. Fracture of the proximal femur is a traumatic injury that would likely result in loss of mission if it were to happen during spaceflight. The low gravity exposure causes decreases in bone mineral density which heightens the concern. Researchers at the NASA Glenn Research Center have quantified bone fracture probability during spaceflight with a probabilistic model. It was assumed that a pressurized extravehicular activity (EVA) suit would attenuate load during a fall, but no supporting data was available. The suit impact load attenuation study was performed to collect analogous data. METHODS: A pressurized EVA suit analog test bed was used to study how the offset, defined as the gap between the suit and the astronaut s body, impact load magnitude and suit operating pressure affects the attenuation of impact load. The attenuation data was incorporated into the probabilistic model of bone fracture as a function of these factors, replacing a load attenuation value based on commercial hip protectors. RESULTS: Load attenuation was more dependent on offset than on pressurization or load magnitude, especially at small offsets. Load attenuation factors for offsets between 0.1 - 1.5 cm were 0.69 +/- 0.15, 0.49 +/- 0.22 and 0.35 +/- 0.18 for mean impact forces of 4827, 6400 and 8467 N, respectively. Load attenuation factors for offsets of 2.8 - 5.3 cm were 0.93 +/- 0.2, 0.94 +/- 0.1 and 0.84 +/- 0.5, for the same mean impact forces. Reductions were observed in the 95th percentile confidence interval of the bone fracture probability predictions. CONCLUSIONS: The reduction in uncertainty and improved confidence in bone fracture predictions increased the fidelity and credibility of the fracture risk model and its benefit to mission design and operational decisions

    KnotProt: a database of proteins with knots and slipknots.

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    The protein topology database KnotProt, http://knotprot.cent.uw.edu.pl/, collects information about protein structures with open polypeptide chains forming knots or slipknots. The knotting complexity of the cataloged proteins is presented in the form of a matrix diagram that shows users the knot type of the entire polypeptide chain and of each of its subchains. The pattern visible in the matrix gives the knotting fingerprint of a given protein and permits users to determine, for example, the minimal length of the knotted regions (knot's core size) or the depth of a knot, i.e. how many amino acids can be removed from either end of the cataloged protein structure before converting it from a knot to a different type of knot. In addition, the database presents extensive information about the biological functions, families and fold types of proteins with non-trivial knotting. As an additional feature, the KnotProt database enables users to submit protein or polymer chains and generate their knotting fingerprints

    Expression of the apoptotic markers in normal breast epithelium, benign mammary dysplasia and in breast cancer

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    Apoptosis and proliferation are processes associated with the development and progression of breast cancer. The sensitivity of tumour cells to the induction of apoptosis depends on the balance between pro- and anti-apoptotic proteins. The expression of Bak and Bcl-2 was examined using an immunohistochemical method in 71 primary breast cancers. Furthermore, Bcl-2 and Bak were assessed in the normal mammary gland as well as in benign mammary dysplasia adjacent to breast cancer. Positive immunostaining for Bcl-2 was observed in 77.8% of cases of normal breast epithelium (NBE), 93% of benign dysplasia without intraductal proliferation (BBD) as well as in 94% of intraductal proliferative lesions of the breast (BIPL). Expression of Bak was detected in 39% of cases of NBE, 45% of BBD and in 67% of BIPL. In breast cancer Bcl-2 and Bak expression was found in 83% and 70% of the cases studied, respectively. Increased Bcl-2 expression in primary tumours significantly correlated with favourable prognostic factors, namely pT1, G2 and lack of metastases to the regional lymph nodes (p < 0.01, p < 0.03, p < 0.02, respectively). There were no relationships between Bak and the clinicopathological features studied, but our results indicate changes in the expression of Bak during breast cancer development and progression. It would appear to be important to assess and compare pro- and anti-apoptotic proteins between normal mammary gland, benign mammary dysplasia and the primary tumours of breast cancer. This knowledge should be helpful in understanding breast cancer development and progression
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