3,235 research outputs found

    Network orchestration in a large inter-organizational project

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    Multiple organizations working jointly on shared activities in inter-organizational projects for a defined period of time are used increasingly to coordinate the supply of complex products, subsystems, and services across many industries. Despite the growth in inter-organizational networks as an organizational form, scholars have only recently begun to identify how lead organizations orchestrate the coordination of multiple parties with disparate goals, responsibilities, and capabilities. Prior work offers limited insights into the choice of network governance forms, and how coordination is undertaken by the network orchestrator to govern these networks. We conducted a longitudinal study of four networks to deliver vital services into a large project. We identified how the choice of network governance form was based on task complexity. A shared governance form was chosen for networks developed to deliver routine services, whereas a lead organization governance form was chosen for networks set up to deliver complex services. However, findings showed that the selection of an appropriate governance form was not sufficient for ensuring high performance. The network orchestrator's mode of coordination (formal or informal), the intensity of coordination (active or passive), and fit with the form of governance form (shared or lead organization governed) was important in driving performance

    A simple interpretation of quantum mirages

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    In an interesting new experiment the electronic structure of a magnetic atom adsorbed on the surface of Cu(111), observed by STM, was projected into a remote location on the same surface. The purpose of the present paper is to interpret this experiment with a model Hamiltonian, using ellipses of the size of the experimental ones, containing about 2300 atoms. The charge distribution for the different wavefunctions is analyzed, in particular, for those with energy close to the Fermi energy of copper Ef. Some of them show two symmetric maxima located on the principal axis of the ellipse but not necessarily at the foci. If a Co atom is adsorbed at the site where the wavefunction with energy EFE_F has a maximum and the interaction is small, the main effect of the adsorbed atom will be to split this particular wavefunction in two. The total charge density will remain the same but the local density of states will present a dip at Ef at any site where the charge density is large enough. We relate the presence of this dip to the observation of quantum mirages. Our interpretation suggests that other sites, apart from the foci of the ellipses, can be used for projecting atomic images and also indicates the conditions for other non magnetic adsorbates to produce mirages.Comment: 3 pages, 3 Fig

    Quantitative Imaging of Protein-Protein Interactions by Multiphoton Fluorescence Lifetime Imaging Microscopy using a Streak camera

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    Fluorescence Lifetime Imaging Microscopy (FLIM) using multiphoton excitation techniques is now finding an important place in quantitative imaging of protein-protein interactions and intracellular physiology. We review here the recent developments in multiphoton FLIM methods and also present a description of a novel multiphoton FLIM system using a streak camera that was developed in our laboratory. We provide an example of a typical application of the system in which we measure the fluorescence resonance energy transfer between a donor/acceptor pair of fluorescent proteins within a cellular specimen.Comment: Overview of FLIM techniques, StreakFLIM instrument, FRET application

    Enumerating Cyclic Orientations of a Graph

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    Acyclic and cyclic orientations of an undirected graph have been widely studied for their importance: an orientation is acyclic if it assigns a direction to each edge so as to obtain a directed acyclic graph (DAG) with the same vertex set; it is cyclic otherwise. As far as we know, only the enumeration of acyclic orientations has been addressed in the literature. In this paper, we pose the problem of efficiently enumerating all the \emph{cyclic} orientations of an undirected connected graph with nn vertices and mm edges, observing that it cannot be solved using algorithmic techniques previously employed for enumerating acyclic orientations.We show that the problem is of independent interest from both combinatorial and algorithmic points of view, and that each cyclic orientation can be listed with O~(m)\tilde{O}(m) delay time. Space usage is O(m)O(m) with an additional setup cost of O(n2)O(n^2) time before the enumeration begins, or O(mn)O(mn) with a setup cost of O~(m)\tilde{O}(m) time

    In-hospital worsening heart failure: a clinically relevant endpoint?

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    Outcome measures used for the clinical evaluation of patients with acute heart failure differ between studies and may neither adequately address the characteristic presenting symptoms and signs nor reflect the pathophysiological processes involved. In‐hospital worsening of heart failure (WHF) is associated with poor outcomes and thus a potential endpoint conveying clinically meaningful prognostic information.Current definitions of WHF are based on the combination of worsening symptoms and signs and the intensification of treatment during admission. Definitions vary across studies and do not fully account for baseline therapy or circumstances in which there is failure to respond to treatment. Further, there are limited data to inform healthcare professionals as to which patients are most at risk of developing in‐hospital WHF.In this opinion piece, we review the definitions for WHF used in recent and ongoing clinical trials and propose a novel definition, which captures failure to respond to treatment as well as clinical worsening (deterioration of symptoms and signs) of the patient's condition. Such a definition, applied consistently across studies, would help clarify the characteristics of patients likely to develop in‐hospital WHF, allow comparative assessments of the effectiveness of interventions, and help guide appropriate patient management in order to improve outcomes

    Cause and Consequences of Genetic and Epigenetic Alterations in Human Cancer

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    Both genetic and epigenetic changes contribute to development of human cancer. Oncogenomics has primarily focused on understanding the genetic basis of neoplasia, with less emphasis being placed on the role of epigenetics in tumourigenesis. Genomic alterations in cancer vary between the different types and stages, tissues and individuals. Moreover, genomic change ranges from single nucleotide mutations to gross chromosomal aneuploidy; which may or may not be associated with underlying genomic instability. Collectively, genomic alterations result in widespread deregulation of gene expression profiles and the disruption of signalling networks that control proliferation and cellular functions. In addition to changes in DNA and chromosomes, it has become evident that oncogenomic processes can be profoundly influenced by epigenetic mechanisms. DNA methylation is one of the key epigenetic factors involved in regulation of gene expression and genomic stability, and is biologically necessary for the maintenance of many cellular functions. While there has been considerable progress in understanding the impact of genetic and epigenetic mechanisms in tumourigenesis, there has been little consideration of the importance of the interplay between these two processes. In this review we summarize current understanding of the role of genetic and epigenetic alterations in human cancer. In addition we consider the associated interactions of genetic and epigenetic processes in tumour onset and progression. Furthermore, we provide a model of tumourigenesis that addresses the combined impact of both epigenetic and genetic alterations in cancer cells

    Economic evaluation protocol of a short, all-oral bedaquiline-containing regimen for the treatment of rifampicin-resistant tuberculosis from the STREAM trial

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    Introduction: A December 2019 WHO rapid communication recommended the use of 9-month all-oral regimens for treating multidrug-resistant tuberculosis (MDR-TB). Besides the clinical benefits, they are thought to be less costly than the injectable-containing regimens, for both the patient and the health system. STREAM is the first randomised controlled trial with an economical evaluation to compare all-oral and injectable-containing 9–11-month MDR-TB treatment regimens. Methods and analysis: Health system costs of delivering a 9-month injectable-containing regimen and a 9-month all-oral bedaquiline-containing regimen will be collected in Ethiopia, India, Moldova and Uganda, using ‘bottom-up’ and ‘top-down’ costing approaches. Patient costs will be collected using questionnaires that have been developed based on the STOP-TB questionnaire. The primary objective of the study is to estimate the cost utility of the two regimens, from a health system perspective. Secondary objectives: include estimating the cost utility from a societal perspective as well as evaluating the cost-effectiveness of the regimens, using both health system and societal perspectives. The effect measure for the cost–utility analysis will be the quality-adjusted life years (QALY), while the effect measure for the cost-effectiveness analysis will be the efficacy outcome from the clinical trial. Ethics and dissemination: The study has been evaluated and approved by the Ethics Advisory Group of the International Union Against Tuberculosis and Lung Disease and also approved by ethics committees in all participating countries. All participants have provided written informed consent. The results of the economic evaluation will be published in a peer-reviewed journal

    The relentless spread of tuberculosis in Zambia - trends over the past 37 years (1964- 2000)

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    Objective. To review trends in the rates of tuberculosis (TB) case notifications over a 37-year period.Design. A retrospective study of Ministry of Health records on TB notifications between 1 January 1964 and 31 December 2000.Setting. Zambia, sub-Saharan Africa.Methods. Retrospective analysis of case-notification data for TB of the Zambia Ministry of Health annual returns.Outcome measures. Annual TB case-notification rates and trends over the past 37 years.Results. TB case-notification data from 1964 to 2000 show a 12-fold increase over the past two decades, and apparent gains in controlling TB seen in the 1960s and 1970s have been reversed over the past two decades. A stable situation during the period 1964 - 1984 (case-notification rate remained around 100 per 100 000 population) was followed by an exponential increase since the mid-1980s. The absolute number of new TBcases increased from 8 246 in 1985 (124/100 000) to 38 863 (409/100 000) in 1996 and 52 000 (512/100 000) in 2000. Comparison of case-notification rates over the past 2 decades with neighbouring countries (Zimbabwe, Malawi and Tanzania) show that Zambia has one of the highest case notification rates in the region.Conclusions. Zambia, like many countries in Africa, is in the midst of a serious TB epidemic and there are no signs that it is abating. This increase was most likely due to the impact of the HIV / AIDS epidemic and subsequent breakdown of TB services. Concerted donor-government efforts should invest appropriately in long-term plans for TB control
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