3,012 research outputs found

    Northrop Frye in context

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    “Diane Dubois takes a contextual approach to Northrop Frye’s work and claims that it is best assessed in relation to his biographical circumstances. In context and in specific details, Dubois’ book seeks to illuminate Frye’s Ɠuvre as a personal, lifelong project. This volume successfully situates Frye’s work within the social, political, religious and philosophical conditions of the time and place of conception and writing. Dubois ranges from Frye’s critical utopia and views on criticism and education through the university, church and William Blake to politics and the Canadian and academic milieu. This book, which is particularly good at tracing Frye’s academic influences and his roots in Methodism and Canada, will have a strong appeal to an international audience of general readers, students, teachers and specialists. Frye is a key figure in the cultural and literary theory of the twentieth century, and Dubois’ accomplished discussion helps us to see his work anew.” Jonathan Hart, author of Northrop Frye: The Theoretical Imagination (1994), Interpreting Cultures (2006), Empires and Colonies (2008) and Literature, Theory, History (2011

    Robustness: a New Form of Heredity Motivated by Dynamic Networks

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    We investigate a special case of hereditary property in graphs, referred to as {\em robustness}. A property (or structure) is called robust in a graph GG if it is inherited by all the connected spanning subgraphs of GG. We motivate this definition using two different settings of dynamic networks. The first corresponds to networks of low dynamicity, where some links may be permanently removed so long as the network remains connected. The second corresponds to highly-dynamic networks, where communication links appear and disappear arbitrarily often, subject only to the requirement that the entities are temporally connected in a recurrent fashion ({\it i.e.} they can always reach each other through temporal paths). Each context induces a different interpretation of the notion of robustness. We start by motivating the definition and discussing the two interpretations, after what we consider the notion independently from its interpretation, taking as our focus the robustness of {\em maximal independent sets} (MIS). A graph may or may not admit a robust MIS. We characterize the set of graphs \forallMIS in which {\em all} MISs are robust. Then, we turn our attention to the graphs that {\em admit} a robust MIS (\existsMIS). This class has a more complex structure; we give a partial characterization in terms of elementary graph properties, then a complete characterization by means of a (polynomial time) decision algorithm that accepts if and only if a robust MIS exists. This algorithm can be adapted to construct such a solution if one exists

    A study of methyl ethyl ketone and butanol-2 by gas-liquid partition chromatography

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    The problem of analysis of commercial and student preparations of butanol-2 from methyl ethyl ketone by gas-liquid partition chromatography is presented. The retention times of butanol-2 and methyl ethyl ketone are determined under varying conditions of temperature, flowrate, carrier gas, column packing and fixed phase concentrations. Optimum conditions are selected for the separation of butanol-2 and methyl ethyl ketone. Several methods are discussed for the quantitative interpretation of the data. The presence of an unknown component in commercial methyl ethyl and ketone and butanol-2 is found and possible identification is discussed. A brief outline of the apparatus is involved and of the theory of gas liquid partition chromatography is included

    Shadow of noncommutativity

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    We analyse the structure of the Îș=0\kappa=0 limit of a family of algebras AÎșA_\kappa describing noncommutative versions of space-time, with Îș\kappa a parameter of noncommutativity. Assuming the Poincar\'e covariance of the Îș=0\kappa=0 limit, we show that, besides the algebra of functions on Minkowski space, A0A_0 must contain a nontrivial extra factor A0IA^I_0 which is Lorentz covariant and which does not commute with the functions whenever it is not commutative. We give a general description of the possibilities and analyse some representative examples.Comment: 19 pages, Latex2e, available at http://qcd.th.u-psud.f

    Neurologic Complications Of Phenothiazine Therapy

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    Clinical Features and Outcomes Differ between Skeletal and Extraskeletal Osteosarcoma.

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    Background. Extraskeletal osteosarcoma (ESOS) is a rare subtype of osteosarcoma. We investigated patient characteristics, overall survival, and prognostic factors in ESOS. Methods. We identified cases of high-grade osteosarcoma with known tissue of origin in the Surveillance, Epidemiology, and End Results database from 1973 to 2009. Demographics were compared using univariate tests. Overall survival was compared with log-rank tests and multivariate analysis using Cox proportional hazards methods. Results. 256/4,173 (6%) patients with high-grade osteosarcoma had ESOS. Patients with ESOS were older, were more likely to have an axial tumor and regional lymph node involvement, and were female. Multivariate analysis showed ESOS to be favorable after controlling for stage, age, tumor site, gender, and year of diagnosis [hazard ratio 0.75 (95% CI 0.62 to 0.90); p = 0.002]. There was an interaction between age and tissue of origin such that older patients with ESOS had superior outcomes compared to older patients with skeletal osteosarcoma. Adverse prognostic factors in ESOS included metastatic disease, larger tumor size, older age, and axial tumor site. Conclusion. Patients with ESOS have distinct clinical features but similar prognostic factors compared to skeletal osteosarcoma. Older patients with ESOS have superior outcomes compared to older patients with skeletal osteosarcoma

    Development of a human model for the study of effects of hypoxia, exercise, and sildenafil on cardiac and vascular function in chronic heart failure

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    Background: Pulmonary hypertension is associated with poor outcome in patients with chronic heart failure (CHF) and may be a therapeutic target. Our aims were to develop a noninvasive model for studying pulmonary vasoreactivity in CHF and characterize sildenafil's acute cardiovascular effects. Methods and Results: In a crossover study, 18 patients with CHF participated 4 times [sildenafil (2 × 20 mg)/or placebo (double-blind) while breathing air or 15% oxygen] at rest and during exercise. Oxygen saturation (SaO2) and systemic vascular resistance were recorded. Left and right ventricular (RV) function and transtricuspid systolic pressure gradient (RVTG) were measured echocardiographically. At rest, hypoxia caused SaO2 (P = 0.001) to fall and RVTG to rise (5 ± 4 mm Hg; P = 0.001). Sildenafil reduced SaO2 (−1 ± 2%; P = 0.043), systemic vascular resistance (−87 ± 156 dyn·s−1·cm−2; P = 0.034), and RVTG (−2 ± 5 mm Hg; P = 0.05). Exercise caused cardiac output (2.1 ± 1.8 L/min; P < 0.001) and RVTG (19 ± 11 mm Hg; P < 0.0001) to rise. The reduction in RVTG with sildenafil was not attenuated by hypoxia. The rise in RVTG with exercise was not substantially reduced by sildenafil. Conclusions: Sildenafil reduces SaO2 at rest while breathing air, this was not exacerbated by hypoxia, suggesting increased ventilation–perfusion mismatching due to pulmonary vasodilation in poorly ventilated lung regions. Sildenafil reduces RVTG at rest and prevents increases caused by hypoxia but not by exercise. This study shows the usefulness of this model to evaluate new therapeutics in pulmonary hypertension

    Thermodynamic Studies of [H_(2)Rh(diphosphine)_2]^+ and [HRh(diphosphine)_(2)(CH_(3)CN)]^(2+) Complexes in Acetonitrile

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    Thermodynamic studies of a series of [H_(2)Rh(PP)_2]^+ and [HRh(PP)_(2)(CH_(3)CN)]^(2+) complexes have been carried out in acetonitrile. Seven different diphosphine (PP) ligands were selected to allow variation of the electronic properties of the ligand substituents, the cone angles, and the natural bite angles (NBAs). Oxidative addition of H_2 to [Rh(PP)_2]^+ complexes is favored by diphosphine ligands with large NBAs, small cone angles, and electron donating substituents, with the NBA being the dominant factor. Large pK_a values for [HRh(PP)_(2)(CH_(3)CN)]^(2+) complexes are favored by small ligand cone angles, small NBAs, and electron donating substituents with the cone angles playing a major role. The hydride donor abilities of [H_(2)Rh(PP)_2]^+ complexes increase as the NBAs decrease, the cone angles decrease, and the electron donor abilities of the substituents increase. These results indicate that if solvent coordination is involved in hydride transfer or proton transfer reactions, the observed trends can be understood in terms of a combination of two different steric effects, NBAs and cone angles, and electron-donor effects of the ligand substituents
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