939 research outputs found
Modeling 21st century project teams: docking workflow and knowledge network computational models
This paper reports on an attempt to integrate and extend two established computational
organizational models\u2014SimVision\uae and Blanche\u2014to examine the co-evolution of workflow
and knowledge networks in 21st century project teams. Traditionally, workflow in project teams
has been modeled as sets of sequential and/or parallel activities each assigned to a responsible
participant, organized in a fixed structure. In the spirit of Jay Galbraith\u2019s (1973) information
processing view of organizations, exceptions\u2014situations in which participants lack the required
knowledge to complete a task\u2014are referred up the hierarchy for resolution. However, recent
developments in digital technologies have created the possibility to design project teams that are
more flexible, self-organizing structures, in which exceptions can be resolved much more
flexibly through knowledge networks that extend beyond the project or even the company
boundaries. In addition to seeking resolution to exceptions up the hierarchy, members of project
teams may be motivated to retrieve the necessary expertise from other knowledgeable members
in the project team. Further, they may also retrieve information from non-human agents, such as
knowledge repositories or databases, available to the project team. Theories, such as Transactive
Memory, Public Goods, Social Exchange and Proximity may guide their choice of retrieving
information from a specific project team member or database. This paper reports on a \u201cdocked\u201d computational model that can be used to generate and test hypotheses about the co-evolution of
workflow and knowledge networks of these 21st century project teams in terms of their
knowledge distribution and performance. The two computational models being docked are
SimVision (Jin & Levitt, 1999) which has sophisticated processes to model organizations
executing project-oriented workflows, and Blanche (Hyatt, Contractor, & Jones, 1997), a multiagent computational network environment, which models multitheoretical mechanisms for the
retrieval and allocation of information in knowledge networks involving human and non-human
agents.
This paper was supported in part by a grant from the U.S. National Science Foundation for
the project \u201cCo-Evolution of Knowledge Networks and 21st Century Organizational Forms (IIS-
9980109)
From sparse to dense and from assortative to disassortative in online social networks
Inspired by the analysis of several empirical online social networks, we
propose a simple reaction-diffusion-like coevolving model, in which individuals
are activated to create links based on their states, influenced by local
dynamics and their own intention. It is shown that the model can reproduce the
remarkable properties observed in empirical online social networks; in
particular, the assortative coefficients are neutral or negative, and the power
law exponents are smaller than 2. Moreover, we demonstrate that, under
appropriate conditions, the model network naturally makes transition(s) from
assortative to disassortative, and from sparse to dense in their
characteristics. The model is useful in understanding the formation and
evolution of online social networks.Comment: 10 pages, 7 figures and 2 table
Lactation and neonatal nutrition: defining and refining the critical questions.
This paper resulted from a conference entitled "Lactation and Milk: Defining and refining the critical questions" held at the University of Colorado School of Medicine from January 18-20, 2012. The mission of the conference was to identify unresolved questions and set future goals for research into human milk composition, mammary development and lactation. We first outline the unanswered questions regarding the composition of human milk (Section I) and the mechanisms by which milk components affect neonatal development, growth and health and recommend models for future research. Emerging questions about how milk components affect cognitive development and behavioral phenotype of the offspring are presented in Section II. In Section III we outline the important unanswered questions about regulation of mammary gland development, the heritability of defects, the effects of maternal nutrition, disease, metabolic status, and therapeutic drugs upon the subsequent lactation. Questions surrounding breastfeeding practice are also highlighted. In Section IV we describe the specific nutritional challenges faced by three different populations, namely preterm infants, infants born to obese mothers who may or may not have gestational diabetes, and infants born to undernourished mothers. The recognition that multidisciplinary training is critical to advancing the field led us to formulate specific training recommendations in Section V. Our recommendations for research emphasis are summarized in Section VI. In sum, we present a roadmap for multidisciplinary research into all aspects of human lactation, milk and its role in infant nutrition for the next decade and beyond
Predicting language diversity with complex network
Evolution and propagation of the world's languages is a complex phenomenon,
driven, to a large extent, by social interactions. Multilingual society can be
seen as a system of interacting agents, where the interaction leads to a
modification of the language spoken by the individuals. Two people can reach
the state of full linguistic compatibility due to the positive interactions,
like transfer of loanwords. But, on the other hand, if they speak entirely
different languages, they will separate from each other. These simple
observations make the network science the most suitable framework to describe
and analyze dynamics of language change. Although many mechanisms have been
explained, we lack a qualitative description of the scaling behavior for
different sizes of a population. Here we address the issue of the language
diversity in societies of different sizes, and we show that local interactions
are crucial to capture characteristics of the empirical data. We propose a
model of social interactions, extending the idea from, that explains the growth
of the language diversity with the size of a population of country or society.
We argue that high clustering and network disintegration are the most important
characteristics of models properly describing empirical data. Furthermore, we
cancel the contradiction between previous models and the Solomon Islands case.
Our results demonstrate the importance of the topology of the network, and the
rewiring mechanism in the process of language change
Metabolic alterations during the growth of tumour spheroids
Solid tumours undergo considerable alterations in their metabolism of nutrients in order to generate sufficient energy and biomass for sustained growth and proliferation. During growth, the tumour microenvironment exerts a number of influences (e.g. hypoxia and acidity) that affect cellular biology and the flux or utilisation of fuels including glucose. The tumour spheroid model was used to characterise the utilisation of glucose and describe alterations to the activity and expression of key glycolytic enzymes during the tissue growth curve. Glucose was avidly consumed and associated with the production of lactate and an acidified medium, confirming the reliance on glycolytic pathways and a diminution of oxidative phosphorylation. The expression levels and activities of hexokinase, phosphofructokinase-1, pyruvate kinase and lactate dehydrogenase in the glycolytic pathway were measured to assess glycolytic capacity. Similar measurements were made for glucose-6-phosphate dehydrogenase, the entry point and regulatory step of the pentose-phosphate pathway (PPP) and for cytosolic malate dehydrogenase, a key link to TCA cycle intermediates. The parameters for these key enzymes were shown to undergo considerable variation during the growth curve of tumour spheroids. In addition, they revealed that the dynamic alterations were influenced by both transcriptional and posttranslational mechanisms
Metabolic alterations during the growth of tumour spheroids
Solid tumours undergo considerable alterations in their metabolism of nutrients in order to generate sufficient energy and biomass for sustained growth and proliferation. During growth, the tumour microenvironment exerts a number of influences (e.g. hypoxia and acidity) that affect cellular biology and the flux or utilisation of fuels including glucose. The tumour spheroid model was used to characterise the utilisation of glucose and describe alterations to the activity and expression of key glycolytic enzymes during the tissue growth curve. Glucose was avidly consumed and associated with the production of lactate and an acidified medium, confirming the reliance on glycolytic pathways and a diminution of oxidative phosphorylation. The expression levels and activities of hexokinase, phosphofructokinase-1, pyruvate kinase and lactate dehydrogenase in the glycolytic pathway were measured to assess glycolytic capacity. Similar measurements were made for glucose-6-phosphate dehydrogenase, the entry point and regulatory step of the pentose-phosphate pathway (PPP) and for cytosolic malate dehydrogenase, a key link to TCA cycle intermediates. The parameters for these key enzymes were shown to undergo considerable variation during the growth curve of tumour spheroids. In addition, they revealed that the dynamic alterations were influenced by both transcriptional and posttranslational mechanisms
Photoactivatable drugs for nicotinic optopharmacology
Photoactivatable pharmacological agents have revolutionized neuroscience, but the palette of available compounds is limited. We describe a general method for caging tertiary amines by using a stable quaternary ammonium linkage that elicits a red shift in the activation wavelength. We prepared a photoactivatable nicotine (PA-Nic), uncageable via one- or two-photon excitation, that is useful to study nicotinic acetylcholine receptors (nAChRs) in different experimental preparations and spatiotemporal scales
Acceleration and Deceleration in the Internationalization Process of the Firm
By adopting a processual and dynamic view on internationalization, we develop the concepts of acceleration and deceleration, providing analytical tools to enhance our understanding of the non-linearity and multidimensionality of internationalization. We argue that acceleration and deceleration are embedded in the internationalization process and are a consequence of the firm’s capability to absorb and integrate acquired knowledge, and to find and exploit opportunities. In addition, we advance the idea that changes in speed are further influenced by how the firm integrates and coordinates the resources it has deployed within and across various internationalization dimensions. Thus, it emerges that the overall evolution of commitment to internationalization is more complex than received theories tend to present; therefore, empirical studies should aim to include a wide set of international activities and processes embedded in time
The impact of licensed-knowledge attributes on the innovation performance of licensee firms: evidence from the Chinese electronic industry
We All Know How, Don’t We? On the Role of Scrum in IT-Offshoring
Part 2: Creating Value through Software DevelopmentInternational audienceOffshoring in the IT-industry involves dual interactions between a mother company and an external supplier, often viewed with an implicit perspective from the mother company. This article review general off shoring and IT offshoring literature, focusing on the proliferation of a globally available set of routines; Scrum and Agile. Two cases are studied; a small company and short process and a large mother company with a long process. The interactions of the set ups shows that global concepts like Scrum and Agile are far from a common platform. The “well known” concepts are locally shaped and the enterprises have mixed experiences
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