A Continuation Method for Weakly Kannan Maps

The first continuation method for contractive maps in the setting of a metric space was given by Granas. Later, Frigon extended Granas theorem to the class of weakly contractive maps, and recently Agarwal and O'Regan have given the corresponding result for a certain type of quasicontractions which includes maps of Kannan type. In this note we introduce the concept of weakly Kannan maps and give a fixed point theorem, and then a continuation method, for this class of maps

A fixed point theorem for weakly Zamfirescu mappings

In [13] T. Zamfirescu, Fixed point theorems in metric spaces, Arch. Math. 23 (1972), 292–298. Zamfirescu gave a fixed point theorem that generalizes the classical fixed point theorems by Banach, Kannan and Chatterjea. In this paper, we follow the ideas of Dugundji and Granas to extend Zamfirescu’s fixed point theorem to the class of weakly Zamfirescu maps. A continuation method for this class of maps is also given.Junta de AndalucíaDirección General de Enseñanza Superio

Rate of convergence under weak contractiveness conditions

We introduce a new class of selfmaps T of metric spaces, which generalizes the weakly Zamfirescu maps (and therefore weakly contraction maps, weakly Kannan maps, weakly Chatterjea maps and quasi-contraction maps with constant h < 1 / 2). We give an explicit Cauchy rate for the Picard iteration sequences {T nx0}n∈N for this type of maps, and show that if the space is complete, then all Picard iteration sequences converge to the unique fixed point of T. Our Cauchy rate depends on the space (X, d), the map T, and the starting point x0 ∈ X only through an upper bound b ≥ d(x0, T x0) and certain moduli θ, µ for the map, but is otherwise fully uniform. As a step on the way to proving our fixed point result we also calculate a modulus of uniqueness for this type of maps.Junta de AndalucíaResearch Council of NorwayDirección General de Enseñanza Superio

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Precariedad, exclusión social y diversidad funcional (discapacidad): lógicas y efectos subjetivos del sufrimiento social contemporáneo (II). Innovación docente en Filosofía

El PIMCD "Precariedad, exclusión social y diversidad funcional (discapacidad): lógicas y efectos subjetivos del sufrimiento social contemporáneo (II). Innovación docente en Filosofía" se ocupa de conceptos generalmente eludidos por la tradición teórica (contando como núcleos aglutinantes los de la precariedad laboral, la exclusión social y diversidad funcional o discapacidad), cuyo análisis propicia nuevas prácticas en la enseñanza universitaria de filosofía, adoptando como meta principal el aprendizaje centrado en el estudiantado, el diseño de nuevas herramientas de enseñanza y el fomento de una universidad inclusiva. El proyecto cuenta con 26 docentes de la UCM y otros 28 docentes de otras 17 universidades españolas (UV, UNED, UGR, UNIZAR, UAH, UC3M, UCA, UNIOVI, ULL, EHU/UPV, UA, UAM, Deusto, IFS/CSIC, UCJC, URJC y Univ. Pontificia de Comillas), que permitirán dotar a las actividades programadas de un alcance idóneo para consolidar la adquisición de competencias argumentativas y dialécticas por parte de lxs estudiantes implicados en el marco de los seminarios previstos. Se integrarán en el PIMCD, aparte de PDI, al menos 26 estudiantes de máster y doctorado de la Facultad de Filosofía, a lxs que acompañarán durante el desarrollo del PIMCD 4 Alumni de la Facultad de Filosofía de la UCM, actualmente investigadores post-doc y profesorxs de IES, cuya experiencia será beneficiosa para su introducción en la investigación. Asimismo, el equipo cuenta con el apoyo de varixs profesorxs asociadxs, que en algunos casos son también profesores de IES. Varixs docentes externos a la UCM participantes en el PIMCD poseen una dilatada experiencia en la coordinación de proyectos de innovación de otras universidades, lo que redundará en beneficio de las actividades a desarrollar. La coordinadora y otrxs miembros del PIMCD pertenecen a la Red de Innovación Docente en Filosofia (RIEF), puesta en marcha desde la Universitat de València (http://rief.blogs.uv.es/encuentros-de-la-rief/), a la que mantendremos informada de las actividades realizadas en el proyecto. Asimismo, lxs 6 miembros del PAS permitirán difundir debidamente las actividades realizadas en el PIMCD entre lxs estudiantes Erasmus IN del curso 2019/20 en la Facultad de Filosofía, de la misma manera que orientar en las tareas de maquetación y edición que puedan ser necesarias de cara a la publicación de lxs resultados del PIMCD y en las tareas de pesquisa bibliográfica necesarias para el desarrollo de los objetivos propuestos. Han manifestado su interés en los resultados derivados del PIMCD editoriales especializadas en la difusión de investigaciones predoctorales como Ápeiron y CTK E-Books

Asymptotic Behavior of Solutions to a Vector Integral Equation with Deviating Arguments

In this paper, we propose the study of an integral equation, with deviating arguments, of the type ( ) = ( ) −

An Application of Krasnoselskii Fixed Point Theorem to the Asymptotic Behavior of Solutions of Difference Equations in Banach Spaces

AbstractIn this paper we consider the first order difference equationΔxn=∑i=0∞ainfxn+i+∑i=0∞bingxn+i+ynand the second order difference equationΔqnΔxn+rnfxn+sngxn+zn=0,where f is a Lipschitz mapping and g is a compact operator, both defined on a Banach space X. We give sufficient conditions so that there exist solutions which are asymptotically constant. These results generalize those given by A. Drozdowicz and J. Popenda (1987, Proc. Amer. Math. Soc.99, 135–140), J. Popenda and E. Schmeidel (1994, Publ. Mat.38, 3–9; 1997, Indian J. Pure Appl. Math.28, 319–327), and E. Schmeidel (1997, Demonstratio Math.30, 193–197; 1997; Comm. Appl. Nonlinear Anal.4, 87–92)

Asymptotic Behavior of Solutions to a Vector Integral Equation with Deviating Arguments

In this paper, we propose the study of an integral equation, with deviating arguments, of the type y(t)=ω(t)-∫0∞‍f(t,s,y(γ1(s)),…,y(γN(s)))ds,t≥0, in the context of Banach spaces, with the intention of giving sufficient conditions that ensure the existence of solutions with the same asymptotic behavior at ∞ as ω(t). A similar equation, but requiring a little less restrictive hypotheses, is y(t)=ω(t)-∫0∞‍q(t,s)F(s,y(γ1(s)),…,y(γN(s)))ds,t≥0. In the case of q(t,s)=(t-s)+, its solutions with asymptotic behavior given by ω(t) yield solutions of the second order nonlinear abstract differential equation y''(t)-ω''(t)+F(t,y(γ1(t)),…,y(γN(t)))=0, with the same asymptotic behavior at ∞ as ω(t)