Time and periodicity from Ptolemy to Schrödinger: paradigm shifts vs continuity in history of mathematics

I briefly consider the Kuhnian notion of "paradigm shifts" applied to the history of mathematics and argue that the succession and intergenerational continuity of mathematical thought was undeservedly neglected in the historical studies. To this end, I focus on the history of mathematical theory of time and periodicity, from Ptolemy's epicycles to Schroedinger's quantum amplitudes interference and contemporary cosmological models

Complex Population Dynamics in Mussels Arising from Density-Linked Stochasticity

Population fluctuations are generally attributed to the deterministic consequences of strong non-linear interactions among organisms, or the effects of random stochastic environmental variation superimposed upon the deterministic skeleton describing population change. Analysis of the population dynamics of the mussel Mytilus californianus taken in 16 plots over 18-years found no evidence that these processes explained observed strong fluctuations. Instead, population fluctuations arose because environmental stochasticity varied with abundance, which we term density-linked stochasticity. This phenomenon arises from biologically relevant mechanisms: recruitment variation and transmission of disturbance among neighboring individuals. Density-linked stochasticity is probably present frequently in populations, as it arises naturally from several general ecological processes, including stage structure variation with density, ontogenetic niche shifts, and local transmission of stochastic perturbations. More thoroughly characterizing and interpreting deviations from the mean behavior of a system will lead to better ecological prediction and improved insight into the important processes affecting populations and ecosystems.</p

En tornar de Murèth /

Localització de l'original digitalitzat: Hons Aran Cultura

Tradition and Prudence in Locke's Exceptions to Toleration

Why did Locke exclude Catholics and atheists from toleration? Not, I contend, because he was trapped by his context, but because his prudential approach and practica ljudgments led him to traditiona ltexts. I make this argumentfirst by outlining the connections among prudential exceptionality, practical judgments, and traditional texts. I then describe important continuities betweenc onventional English understandings of the relationship between state and religion and Locke's writings on toleration, discuss Locke's conception of rights, and illustrate his use of prudential exceptions and distinctions. I conclude by arguing that Locke's problems are relevant to assessingc ontemporary liberal discussions of tolerationa nd the separation of state and religion that lean heavily on practical justification

Estimating travel reduction associated with the use of telemedicine by patients and healthcare professionals: proposal for quantitative synthesis in a systematic review

<p>Abstract</p> <p>Background</p> <p>A major benefit offered by telemedicine is the avoidance of travel, by patients, their carers and health care professionals. Unfortunately, there is very little published information about the extent of avoided travel. We propose to undertake a systematic review of literature which reports credible data on the reductions in travel associated with the use of telemedicine.</p> <p>Method</p> <p>The conventional approach to quantitative synthesis of the results from multiple studies is to conduct a meta analysis. However, too much heterogeneity exists between available studies to allow a meaningful meta analysis of the avoided travel when telemedicine is used across all possible settings. We propose instead to consider all credible evidence on avoided travel through telemedicine by fitting a linear model which takes into account the relevant factors in the circumstances of the studies performed. We propose the use of stepwise multiple regression to identify which factors are significant.</p> <p>Discussion</p> <p>Our proposed approach is illustrated by the example of teledermatology. In a preliminary review of the literature we found 20 studies in which the percentage of avoided travel through telemedicine could be inferred (a total of 5199 patients). The mean percentage avoided travel reported in the 12 store-and-forward studies was 43%. In the 7 real-time studies and in a single study with a hybrid technique, 70% of the patients avoided travel. A simplified model based on the modality of telemedicine employed (i.e. real-time or store and forward) explained 29% of the variance. The use of store and forward teledermatology alone was associated with 43% of avoided travel. The increase in the proportion of patients who avoided travel (25%) when real-time telemedicine was employed was significant (<it>P </it>= 0.014). Service planners can use this information to weigh up the costs and benefits of the two approaches.</p