15,135 research outputs found
Formal integration archetypes in ambidextrous organizations
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordResearch suggests that organizational ambidexterity, an organization's capacity to pursue both exploratory and exploitative activities, is critical to firm innovation and performance. Extant research primarily emphasizes several firm‐level informal integration mechanisms, such as creating a common vision and relying on social integration, for integrating structurally ambidextrous units. Research has largely ignored, however, the formal mechanisms by which organizations have integrated such units. In this inductive study, using archival and interview data from organizations in Silicon Valley, we address this gap by identifying the formal integration archetypes that enable core business units to collaborate with new venture units to incubate new businesses. The four integration archetypes that enable collaboration vary along two key dimensions: who initiates new ventures and when collaboration is solicited. We identify formal administrative and resource mechanisms that enable such collaboration. We combine the disparate literatures of temporal and spatial separation of ambidextrous structures, and demonstrate how these must be combined at the business unit and new venture levels of analysis to achieve integration. The practical contribution of this study lies in identifying suitable contexts in which each of these archetypes can be utilized by practitioners for reintegrating new venture projects developed in separate structures
MAC Performance Analysis for Drive-Thru Internet Networks with Rayleigh Capture
© 2013 IEEE. In practical radio transmissions, channel capture is a dominating factor that affects wireless network performance. The capture effect can occur in wireless network when packets arrive with different powers. Packets with high power can effectively swamp low power packets, such that they are received successfully, when otherwise a collision would have occurred. We present a vehicular network performance-prediction model for a Rayleigh capture channel in Drive-thru Internet scenario. The model incorporates the capture effect into a 2-D Markov chain modeling the high-node mobility and distributed coordination function broadcast scheme. The performance-prediction model unveils the impacts of mobility velocity and number of vehicles on the throughput in a Rayleigh capture channel. We use a vehicular traffic flow model to predict vehicular movement on road by aggregating all vehicles into a flow. Simulation results confirm that our performance-prediction model accurately predicts the performance of traveling vehicles with Rayleigh capture channel in the Drive-thru Internet scenario. We demonstrate that using our performance-prediction model, we can obtain optimal contention window value, by which the best system throughput can be reached without wasting contention time. This is also proved by Anastasi et al
Automated Policy Combination for Secure Data Sharing in Cross-Organizational Collaborations
© 2016 IEEE. During business collaborations, multiple participating organizations often need to share data for common interests. In such cases, it is necessary to combine local policies from different organizations into a global one in order to manage access to the shared data. However, local policies of organizations may be different or even conflicting, due to diverse rules and rule combining algorithms chosen. Few existing methods for policy combination are able to automatically combine multiple local policies into a global one. In this paper, we propose a bottom-up approach to address the issues of multiple policy combinations. The key idea is to first classify the rules based on attribute constraints in each policy, and then reduce the rules of the corresponding classes to one with the same attribute constraints. The reduced rules are then combined into a new global policy by choosing the appropriate rule combining algorithm in XACML. The latter ensures compliance with each of the local policies at syntax and semantic levels. To validate our approach, we develop a proof-of-concept implementation of the automated policy combination. Experimental results demonstrate that our approach is highly scalable and supports a number of attribute constraints in each local policy
Phage inducible islands in the gram-positive cocci
The SaPIs are a cohesive subfamily of extremely common phage-inducible chromosomal islands (PICIs) that reside quiescently at specific att sites in the staphylococcal chromosome and are induced by helper phages to excise and replicate. They are usually packaged in small capsids composed of phage virion proteins, giving rise to very high transfer frequencies, which they enhance by interfering with helper phage reproduction. As the SaPIs represent a highly successful biological strategy, with many natural Staphylococcus aureus strains containing two or more, we assumed that similar elements would be widespread in the Gram-positive cocci. On the basis of resemblance to the paradigmatic SaPI genome, we have readily identified large cohesive families of similar elements in the lactococci and pneumococci/streptococci plus a few such elements in Enterococcus faecalis. Based on extensive ortholog analyses, we found that the PICI elements in the four different genera all represent distinct but parallel lineages, suggesting that they represent convergent evolution towards a highly successful lifestyle. We have characterized in depth the enterococcal element, EfCIV583, and have shown that it very closely resembles the SaPIs in functionality as well as in genome organization, setting the stage for expansion of the study of elements of this type. In summary, our findings greatly broaden the PICI family to include elements from at least three genera of cocci
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De novo design of bioactive protein switches.
Allosteric regulation of protein function is widespread in biology, but is challenging for de novo protein design as it requires the explicit design of multiple states with comparable free energies. Here we explore the possibility of designing switchable protein systems de novo, through the modulation of competing inter- and intramolecular interactions. We design a static, five-helix 'cage' with a single interface that can interact either intramolecularly with a terminal 'latch' helix or intermolecularly with a peptide 'key'. Encoded on the latch are functional motifs for binding, degradation or nuclear export that function only when the key displaces the latch from the cage. We describe orthogonal cage-key systems that function in vitro, in yeast and in mammalian cells with up to 40-fold activation of function by key. The ability to design switchable protein functions that are controlled by induced conformational change is a milestone for de novo protein design, and opens up new avenues for synthetic biology and cell engineering
Evaluation of a Bayesian inference network for ligand-based virtual screening
Background
Bayesian inference networks enable the computation of the probability that an event will occur. They have been used previously to rank textual documents in order of decreasing relevance to a user-defined query. Here, we modify the approach to enable a Bayesian inference network to be used for chemical similarity searching, where a database is ranked in order of decreasing probability of bioactivity.
Results
Bayesian inference networks were implemented using two different types of network and four different types of belief function. Experiments with the MDDR and WOMBAT databases show that a Bayesian inference network can be used to provide effective ligand-based screening, especially when the active molecules being sought have a high degree of structural homogeneity; in such cases, the network substantially out-performs a conventional, Tanimoto-based similarity searching system. However, the effectiveness of the network is much less when structurally heterogeneous sets of actives are being sought.
Conclusion
A Bayesian inference network provides an interesting alternative to existing tools for ligand-based virtual screening
On nonoscillatory solutions tending to zero of third-order nonlinear dynamic equations on time scales
General disease resistance loci against biotrophic pathogens in wheat
Dissertação de Mestrado Integrado em Arquitectura, apresentada ao Departamento de Arquitectura da Faculdade de Ciências e Tecnologia da Universidade de Coimbra, sob a orientação do Prof. Doutor Walter Rossa.Um ano depois de a UNESCO inscrever a “Universidade de Coimbra - Alta e
Sofia” na lista do Património Mundial da Humanidade e face ao desafio académico
de Coimbra Capital Europeia da Cultura em 2027, este trabalho tem como objectivo
analisar e perceber como se alterou a imagem urbana da cidade e de que maneira o
branding que proponho para a mesma vai clarificar essa imagem, de forma a criar
uma linguagem coerente e clara, que traga valor para Coimbra.
O trabalho divide-se em quatro partes. A primeira exibe a importância do
branding para as cidades, entendendo que este conceito é fundamental para que
Coimbra construa uma visão de futuro, com uma melhoria no espaço público e
com uma linguagem coerente entre a Universidade a tudo o que a dinamiza. A
segunda parte, analisa a evolução da imagem e do sistema urbano do espaço que
escolhi como exemplo de trabalho, a antiga Quinta de Santa Cruz, onde foi criado
o “boulevard” da cidade, a Avenida Sá da Bandeira e a Praça da República. Na
terceira parte, vou analisar criticamente estes dois espaços de maneira a perceber
como alterar a imagem suja que a cidade tem hoje, clarificando-a e sabendo que
esta zona tem tudo para ser o verdadeiro centro cosmopolita de Coimbra.
Por último, associo a esse exemplo um de outra natureza, mas com ele coerente
no compto geral do processo, a criação de um logótipo que vai qualificar a cidade
e que vai estar presente na mudança do sistema urbano, ajudando a clarificar a
imagem da cidade.One year later that UNESCO aggregated “Universidade de Coimbra - Alta
e Sofia” at the list of World Heritage Site and the academic challenge of Coimbra
European Capital of Culture in 2027, this work aims to analyze and understand
how changed the image of urban city , and that way, how the branding that i’ll
propose for the city, will clarify this image in order to create a coherent and clear
language that bring value to Coimbra.
The work is divided into four parts. A first that displays the importance of
branding for cities, and how these concept is fundamental to Coimbra build a
vision of future, with an improvement in public space and with identical language
between the University and everything that surrounds it. The second part examines
the evolution of the urban system and the image of the space that i found as an
example to work, the old Quinta de Santa Cruz, where the “boulevard” of the city
with the Avenue Sá da Bandeira and Republic Square was created. In the third
part i will analyze and criticize these two spaces so that you can understand how
to clean the soiled image that the city transpires today, in order to make clear that
this space has everything to be the true cosmopolitan center of Coimbra.
Finally i will associate this example to other of a diferent nature, but coherent
in the overall process, the creation of a logo that will qualify the city and that will
be present in the changing of urban system helping to clarify the city’s image
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