Developing elementary algebraic reasoning through counting with patterns activities

Las tareas de recuento con patrones son un contexto privilegiado para el desarrollo del razonamiento algebraico. La complejidad ontosemiótica de las tareas permite identificar procesos de estudio para hacer progresar el desempeño en sucesivos niveles de algebrización, desde la manipulación meramente aritmética hasta una práctica con un nivel algebraico consolidado. El objetivo es doble: por un lado, elaborar indicadores que permitan valorar el desempeño de una práctica operatoria y discursiva en la resolución de tareas de recuento de patrones; por otro lado, proponer una secuencia que tenga en cuenta las restricciones epistemológicas, cognitivas y de enseñanza propias de estas prácticas. Un diseño pre-test y post-test mediante un cuestionario de preguntas abiertas y el análisis cualitativo de las respuestas por estudio de casos aporta información relevante sobre el desarrollo del razonamiento algebraico de los sujetos en los sucesivos niveles de algebrización. Se concluye que el Pensamiento Matemático Flexible es un indicador clave de la competencia algebraica de los sujetos, y se aporta una secuencia de enseñanza que parte de una estrategia inicial, basada en manipulaciones concretas y generalizaciones cercanas hasta el análisis de distintas expresiones analíticas.The counting tasks with patterns are a privileged context for the development of algebraic reasoning. The onto-semiotic complexity of tasks allows the identification of study processes to improve performance in successive algebrization levels, from purely arithmetic manipulation to a practice with a consolidated algebraic level. The objective is twofold: on the one hand, to elaborate indicators that allow evaluating the performance of an operative and discursive practice in the task resolution of counting patterns. On the other hand, to propose a sequence that takes into account the epistemological, cognitive, and teaching restrictions common to these practices. A pre-test and post-test design is proposed using an open-ended questionnaire. A qualitative analysis is carried out through a case study, which provides relevant information on the development of the subjects' algebraic reasoning in the successive algebrization levels. It is concluded that Flexible Mathematical Thinking is a key indicator of the subjects' algebraic competence; we also provided a teaching sequence that start from a basic strategy based on concrete manipulations and close generalizations to the analysis of different analytical expressions

Etiological diagnosis, prognostic significance and role of electrophysiological study in patients with Brugada ECG and syncope.

BACKGROUND: Syncope is considered a risk factor for life-threatening arrhythmias in Brugada patients. Distinguishing a benign syncope from one due to ventricular arrhythmias is often difficult, unless an ECG is recorded during the episode. Aim of the study was to analyze the characteristics of syncopal episodes in a large population of Brugada patients and evaluate the role of electrophysiological study (EPS) and the prognosis in the different subgroups. METHODS AND RESULTS: One hundred ninety-five Brugada patients with history of syncope were considered. Syncope were classified as neurally mediated (group 1, 61%) or unexplained (group 2, 39%) on the basis of personal and family history, clinical features, triggers, situations, associated signs, concomitant therapy. Most patients underwent EPS; they received ICD or implantable loop-recorder on the basis of the result of investigations and physician's judgment. At 62±45months of mean follow-up, group 1 showed a significantly lower incidence of arrhythmic events (2%) as compared to group 2 (9%, p<0.001). Group 2 patients with positive EPS showed the highest risk of arrhythmic events (27%). No ventricular events occurred in subjects with negative EPS. CONCLUSION: Etiological definition of syncope in Brugada patients is important, as it allows identifying two groups with different outcome. Patients with unexplained syncope and ventricular fibrillation induced at EPS have the highest risk of arrhythmic events. Patients presenting with neurally mediated syncope showed a prognosis similar to that of the asymptomatic and the role of EPS in this group is unproven

Aesthetic experience and spiritual well-being: locating the role of theological commitments

I discuss three accounts of the spiritual significance of aesthetic experience. Two of these perspectives I have taken from the recent literature in theological aesthetics, and the third I have constructed, building on Thomas Aquinas’s conception of the goods of the infused moral virtues. This broadly Thomistic approach occupies, I argue, a middle ground between the other two, on account of its distinctive understanding of the role of theological context in defining spiritually significant goods. These perspectives are not mutually exclusive, but they do present rather different conceptions of the ways in which aesthetic goods can contribute to spiritual well-being, and provide a focus for religious practice

Incidence, etiology and predictors of adverse outcomes in 43,315 patients presenting to the Emergency Department with syncope: An international meta-analysis.

BACKGROUND: Syncope remains challenging for Emergency Department (ED) physicians due to difficulties in assessing the risk of future adverse outcomes. The aim of this meta-analysis is to establish the incidence and etiology of adverse outcomes as well as the predictors, in patients presenting with syncope to the ED. METHODS: A systematic electronic literature review was performed looking for eligible studies published between 1990 and 2010. Studies reporting multivariate predictors of adverse outcomes in patients presenting with syncope to the ED were included and pooled, when appropriate, using a random-effect method. Adverse events were defined as 'incidence of death, or of hospitalization and interventional procedures because of arrhythmias, ischemic heart disease or valvular heart disease'. RESULTS: 11 studies were included. Pooled analysis showed 42% (CI 95%; 32-52) of patients were admitted to hospital. Risk of death was 4.4% (CI 95%; 3.1-5.1) and 1.1% (CI 95%; 0.7-1.5) had a cardiovascular etiology. One third of patients were discharged without a diagnosis, while the most frequent diagnosis was 'situational, orthostatic or vasavagal syncope' in 29% (CI 95%; 12-47). 10.4% (CI 95%; 7.8-16) was diagnosed with heart disease, the most frequent type being bradyarrhythmia, 4.8% (CI 95%; 2.2-6.4) and tachyarrhythmia 2.6% (CI 95%; 1.1-3.1). Palpitations preceding syncope, exertional syncope, a history consistent of heart failure or ischemic heart disease, and evidence of bleeding were the most powerful predictors of an adverse outcome. CONCLUSION: Syncope carries a high risk of death, mainly related to cardiovascular disease. This large study which has established the most powerful predictors of adverse outcomes, may enable care and resources to be better focused at high risk patients. Copyright \ua9 2011 Elsevier Ireland Ltd. All rights reserved

Spectroscopic analysis of vibronic relaxation pathways in molecular spin qubit [Ho(W5O18)2]9−: sparse spectra are key

Vibrations play a prominent role in magnetic relaxation processes of molecular spin qubits as they couple to spin states, leading to the loss of quantum information. Direct experimental determination of vibronic coupling is crucial to understand and control the spin dynamics of these nano-objects, which represent the limit of miniaturization for quantum devices. Herein, we measure the magneto-infrared properties of the molecular spin qubit system Na9[Ho(W5O18)2]·35H2O. Our results place significant constraints on the pattern of crystal field levels and the vibrational excitations allowing us to unravel vibronic decoherence pathways in this system. We observe field-induced spectral changes near 63 and 370 cm-1 that are modeled in terms of odd-symmetry vibrations mixed with f-manifold crystal field excitations. The overall extent of vibronic coupling in Na9[Ho(W5O18)2]·35H2O is limited by a modest coupling constant (on the order of 0.25) and a transparency window in the phonon density of states that acts to keep the intramolecular vibrations and MJ levels apart. These findings advance the understanding of vibronic coupling in a molecular magnet with atomic clock transitions and suggest strategies for designing molecular spin qubits with improved coherence lifetimes

Does periprocedural anticoagulation management of atrial fibrillation affect the prevalence of silent thromboembolic lesion detected by diffusion cerebral magnetic resonance imaging in patients undergoing radiofrequency atrial fibrillation ablation with open irrigated catheters? Results from a prospective multicenter study

BackgroundSilent cerebral ischemia (SCI) has been reported in 14% of cases after catheter ablation of atrial fibrillation (AF) with radiofrequency (RF) energy and discontinuation of warfarin before AF ablation procedures.ObjectiveThe purpose of this study was to determine whether periprocedural anticoagulation management affects the incidence of SCI after RF ablation using an open irrigated catheter.MethodsConsecutive patients undergoing RF ablation for AF without warfarin discontinuation and receiving heparin bolus before transseptal catheterization (group I, n = 146) were compared with a group of patients who had protocol deviation in terms of maintaining the therapeutic preprocedural international normalized ratio (patients with subtherapeutic INR) and/or failure to receive pretransseptal heparin bolus infusion and/or ≥2 consecutive ACT measurements <300 seconds (noncompliant population, group II, n = 134) and with a group of patients undergoing RF ablation with warfarin discontinuation bridged with low molecular weight heparin (group III, n = 148). All patients underwent preablation and postablation (within 48 hours) diffusion magnetic resonance imaging.ResultsSCI was detected in 2% of patients (3/146) in group I, 7% (10/134) in group II, and 14% (21/148) in group III (P <.001). “Therapeutic INR” was strongly associated with a lower prevalence of postprocedural silent cerebral ischemia (SCI). Multivariable analysis demonstrated nonparoxysmal AF (odds ratio 3.8, 95% confidence interval 1.5–9.7, P = .005) and noncompliance to protocol (odds ratio 2.8, 95% confidence interval 1.5–5.1, P <.001] to be significant predictors of ischemic events.ConclusionStrict adherence to an anticoagulation protocol significantly reduces the prevalence of SCI after catheter ablation of AF with RF energy

Human rights and community work. Complementary theories and practices

Much effort has been placed on developing international understandings of human rights without the corresponding attention to responsibilities. The authors argue that a community development framework may be useful in re-conceiving human rights in a more holistic way, and that social workers and community development workers are well placed to be 'grass roots human rights workers