4,690 research outputs found

    Potential uses of Numerical Simulation for the Modelling of Civil Conflict

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    This paper explores ways in which civil conflict can be simulated using numerical methods. A general two-party model of conflict is developed by extending an approach proposed by [Christia, F., (2012), Alliance Formation in Civil Wars, Cambridge University Press, New York], which is based on a metric of the 'relative power' that exists between the state and a rebel group. Various definitions of relative power are considered and one of these is chosen to illustrate different types of two-sided armed conflict, namely direct-fire, guerrilla and asymmetric warfare. The additional suggestion of Christia that random or stochastic events can lead to unexpected conflict outcomes is also further extended in this paper. The inclusion in the model of terms describing concurrent rebel recruitment of civilians and state deployment of troops are then described. Examples are presented for various hypothetical cases. It is demonstrated that numerical simulation techniques have great potential for modelling civil war. The Christia approach is shown to provide an excellent basis from which numerical models of civil conflict can be built and from which the progress of a conflict can usefully be visualised graphically

    Qualitative Factors as Determinants of Continued Success:An Examination of eBusiness Entrepreneurial Firms Using the NewVenture Template

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    In this study, we analyze eBusiness entrepreneurs nominated by the Ernst & Young Entrepreneur of the Year Award program to ascertain whether qualitative factors are correlated with success. We find qualitative factors are incrementally informative above and beyond the information provided by quantitative factors. More specifically, firms that are able to maintain their innovative strategies by improving upon the product (or service) they offer and are able to meet the long-term needs of the customer are more likely to experience increased sales growth and have greater access to capital which results in a successful harvest strategy

    Live Cell Imaging Unveils Multiple Domain Requirements for In Vivo Dimerization of the Glucocorticoid Receptor

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    Glucocorticoids are essential for life, but are also implicated in disease pathogenesis and may produce unwanted effects when given in high doses. Glucocorticoid receptor (GR) transcriptional activity and clinical outcome have been linked to its oligomerization state. Although a point mutation within the GR DNA-binding domain (GRdim mutant) has been reported as crucial for receptor dimerization and DNA binding, this assumption has recently been challenged. Here we have analyzed the GR oligomerization state in vivo using the number and brightness assay. Our results suggest a complete, reversible, and DNA-independent ligand-induced model for GR dimerization. We demonstrate that the GRdim forms dimers in vivo whereas adding another mutation in the ligand-binding domain (I634A) severely compromises homodimer formation. Contrary to dogma, no correlation between the GR monomeric/dimeric state and transcriptional activity was observed. Finally, the state of dimerization affected DNA binding only to a subset of GR binding sites. These results have major implications on future searches for therapeutic glucocorticoids with reduced side effects.Fil: Presman, Diego Martin. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica BiolĂłgica; ArgentinaFil: Ogara, Maria Florencia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica BiolĂłgica; ArgentinaFil: Stortz, Martin Dario. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica BiolĂłgica; ArgentinaFil: Alvarez, Lautaro Damian. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Unidad de MicroanĂĄlisis y MĂ©todos FĂ­sicos en QuĂ­mica OrgĂĄnica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de MicroanĂĄlisis y MĂ©todos FĂ­sicos en QuĂ­mica OrgĂĄnica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica OrgĂĄnica; ArgentinaFil: Pooley, John R.. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados Unidos. University of Bristol; Reino UnidoFil: Schiltz, R. Louis. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: GrĂžntved, Lars. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Johnson, Thomas A.. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Mittelstadt, Paul R.. National Cancer Institute. Laboratory of Immune Cell Biology; Estados UnidosFil: Ashwell, Jonathan D.. National Cancer Institute. Laboratory of Immune Cell Biology; Estados UnidosFil: Ganesan, Sundar. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados Unidos. National Institute of Allergy and Infectious Diseases; Estados UnidosFil: Burton, Gerardo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Unidad de MicroanĂĄlisis y MĂ©todos FĂ­sicos en QuĂ­mica OrgĂĄnica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de MicroanĂĄlisis y MĂ©todos FĂ­sicos en QuĂ­mica OrgĂĄnica; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica OrgĂĄnica; ArgentinaFil: Levi, Valeria. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂ­mica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica BiolĂłgica; ArgentinaFil: Hager, Gordon L.. National Cancer Institute. Laboratory of Receptor Biology and Gene Expression; Estados UnidosFil: Pecci, Adali. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂ­a, BiologĂ­a Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂ­mica BiolĂłgica; Argentin

    Fast coarsening in unstable epitaxy with desorption

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    Homoepitaxial growth is unstable towards the formation of pyramidal mounds when interlayer transport is reduced due to activation barriers to hopping at step edges. Simulations of a lattice model and a continuum equation show that a small amount of desorption dramatically speeds up the coarsening of the mound array, leading to coarsening exponents between 1/3 and 1/2. The underlying mechanism is the faster growth of larger mounds due to their lower evaporation rate.Comment: 4 pages, 4 PostScript figure

    Joint analysis of stressors and ecosystem services to enhance restoration effectiveness

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    With increasing pressure placed on natural systems by growing human populations, both scientists and resource managers need a better understanding of the relationships between cumulative stress from human activities and valued ecosystem services. Societies often seek to mitigate threats to these services through large-scale, costly restoration projects, such as the over one billion dollar Great Lakes Restoration Initiative currently underway. To help inform these efforts, we merged high-resolution spatial analyses of environmental stressors with mapping of ecosystem services for all five Great Lakes. Cumulative ecosystem stress is highest in near-shore habitats, but also extends offshore in Lakes Erie, Ontario, and Michigan. Variation in cumulative stress is driven largely by spatial concordance among multiple stressors, indicating the importance of considering all stressors when planning restoration activities. In addition, highly stressed areas reflect numerous different combinations of stressors rather than a single suite of problems, suggesting that a detailed understanding of the stressors needing alleviation could improve restoration planning. We also find that many important areas for fisheries and recreation are subject to high stress, indicating that ecosystem degradation could be threatening key services. Current restoration efforts have targeted high-stress sites almost exclusively, but generally without knowledge of the full range of stressors affecting these locations or differences among sites in service provisioning. Our results demonstrate that joint spatial analysis of stressors and ecosystem services can provide a critical foundation for maximizing social and ecological benefits from restoration investments. www.pnas.org/lookup/suppl/doi:10.1073/pnas.1213841110/-/DCSupplementa

    Oat consumption reduced intestinal fat deposition and improved health span in Caenorhabditis elegans model

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    © 2015 The Authors. In addition to their fermentable dietary fiber and the soluble ÎČ-glucan fiber, oats have unique avenanthramides that have anti-inflammatory and antioxidant properties that reduce coronary heart disease in human clinical trials. We hypothesized that oat consumption will increase insulin sensitivity, reduce body fat, and improve health span in Caenorhabditis elegans through a mechanism involving the daf-2 gene, which codes for the insulin/insulin-like growth factor-1-like receptor, and that hyperglycemia will attenuate these changes. Caenorhabditis elegans wild type (N2) and the null strains sir-2.1, daf-16, and daf-16/daf-2 were fed Escherichia coli (OP50) and oat flakes (0.5%, 1.0%, or 3%) with and without 2% glucose. Oat feeding decreased intestinal fat deposition in N2, daf-16, or daf-16/daf-2 strains (P \u3c.05); and glucose did not affect intestinal fat deposition response. The N2, daf-16, or sir-2.1 mutant increased the pharyngeal pumping rate (P \u3c.05), a surrogate marker of life span, following oat consumption. Oat consumption increased ckr-1, gcy-8, cpt-1, and cpt-2 mRNA expression in both the N2 and the sir-2.1 mutant, with significantly higher expression in sir-2.1 than in N2 (P \u3c.01). Additional glucose further increased expression 1.5-fold of the 4 genes in N2 (P \u3c.01), decreased the expression of all except cpt-1 in the daf-16 mutant, and reduced mRNA expression of the 4 genes in the daf-16/daf-2 mutant (P \u3c.01). These data suggest that oat consumption reduced fat storage and increased ckr-1, gcy-8, cpt-1, or cpt-2 through the sir-2.1 genetic pathway. Oat consumption may be a beneficial dietary intervention for reducing fat accumulation, augmenting health span, and improving hyperglycemia-impaired lipid metabolism

    Experiences and views of receiving and delivering information about recovery in acquired neurological conditions: a systematic review of qualitative literature

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    Objective To review and synthesise qualitative literature relating to the views, perceptions and experiences of patients with acquired neurological conditions and their caregivers about the process of receiving information about recovery; as well as the views and experiences of healthcare professionals involved in delivering this information. Design Systematic review of qualitative studies. Data sources MEDLINE, Embase, AMED, CINAHL, PsycINFO, Web of Science and the Cochrane library were searched from their inception to July 2019. Data extraction and synthesis Two reviewers extracted data from the included studies and assessed quality using an established tool. Thematic synthesis was used to synthesise the findings of included studies. Results Searches yielded 9105 titles, with 145 retained for full-text screening. Twenty-eight studies (30 papers) from eight countries were included. Inductive analysis resulted in 11 descriptive themes, from which 5 analytical themes were generated: the right information at the right time; managing expectations; it’s not what you say, it’s how you say it; learning how to talk about recovery and manage emotions; the context of uncertainty. Conclusions Our findings highlight the inherent challenges in talking about recovery in an emotional context, where breaking bad news is a key feature. Future interventions should focus on preparing staff to meet patients’ and families’ information needs, as well as ensuring they have the skills to discuss potential recovery and break bad news compassionately and share the uncertain trajectory characteristic of acquired neurological conditions. An agreed team-based approach to talking about recovery is recommended to ensure consistency and improve the experiences of patients and their families

    Why are the K dwarfs in the Pleiades so Blue?

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    The K dwarfs in the Pleiades fall nearly one half magnitude below a main sequence isochrone when plotted in a color-magnitude diagram utilizing V magnitude as the luminosity index and B-V as the color index. This peculiarity has been known for forty years but has gone unexplained and mostly ignored. When compared to Praesepe members, the Pleiades K dwarfs again are subluminous (or blue) in a color-magnitude diagram using B-V as the color index. However, using V-I as the color index, stars in the two clusters are coincident to M_V ~ 10; using V-K as the color index, Pleiades late K and M stars fall above the main sequence locus defined by Praesepe members. We believe that the anomalous spectral energy distributions for the Pleiades K dwarfs, as compared to older clusters, are a consequence of rapid stellar rotation and may be primarily due to spottedness. If so, the required areal filling factor for the cool component has to be very large (=> 50%). Weak-lined T Tauri stars have similar color anomalies, and we suspect this is a common feature of all very young K dwarfs (sp. type > K3). The peculiar spectral energy distribution needs to be considered in deriving accurate pre-main sequence isochrone-fitting ages for clusters like the Pleiades since the age derived will depend on the temperature index used.Comment: 41 pages, 15 figures, AASTeX5.0. Accepted 05 May 2003; Scheduled for publication in the Astronomical Journal (August 2003
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