The physician: From certainty to complexity

There is no doubt that during the nineteenth and the first half of the twentieth century physicians were considered less as simple prescribers of medicaments and a source of ready cash, and more as the bearers of a precious patrimony of science and wisdom destined to be passed on to others and further enriched over time. Such figures are becoming extinct. Their epigones (by now considered old-fashioned) are going through a profound crisis which reflects the status of the medical world as a whole. The rapid growth of social needs seems to parallel the disappearance of the very foundations onwhich this kind of doctor based his existence, but the intricate and intriguing historical regression of clinical medicine, and the disordered rhythm of its scientific revolutions, can also be identified as significant epistemiological and ethical elements.An analysis exploring the decline of this typology of physician is not easy because the number of intelligible real facts exceeds the cognitive and organisational capacities of a single human mind. This obliges us to gather causes and connections, and bring different events together into ad hoc historical units. A criterion for ordering the set of  events concerning the evolution of the physician figure can be the concept of complexity,which has shaken the certainties of the logical bases of traditional medicine. In the light of this concept, the course of the development of medicine can be divided into three epochs:- the first epoch is characterised by the episteme of the certainty derived from transcendental faith;- the second, which began in the Baroque age, by an episteme based on the certainties deriving from faith in scientific research;Paper partially sponsorized by: Fondazione Michele Rodriguez - Scientific Foundation for Quantitative Measurements in Medicine, Milan Italy and Quantitative Measurements Centre, Scientific Department, Istituto Clinico Humanitas, Rozzano Milan Italy.- the third and present epoch is increasingly characterised by an episteme whose essence lies in uncertainty due to the complexity highlighted by technology

Palatini F(R,X)F(R,X): a new framework for inflationary attractors

Palatini $F(R)$ gravity proved to be a powerful tool in order to realize asymptotically flat inflaton potentials. Unfortunately, it also inevitably implies higher-order inflaton kinetic terms in the Einstein frame that might jeopardize the evolution of the system out of the slow-roll regime. We prove that a $F(R-X)$ gravity, where $X$ is the inflaton kinetic term, solves the issue. Moreover, when $F$ is a quadratic function such a choice easily leads to a new class of inflationary attractors, fractional attractors, that generalizes the already well-known polynomial $\alpha$-attractors.Comment: 6 pages, 3 figure

PYFLOW_2.0: a computer program for calculating flow properties and impact parameters of past dilute pyroclastic density currents based on field data

This paper presents PYFLOW_2.0, a hazard tool for the calculation of the impact parameters of dilute pyroclastic density currents (DPDCs). DPDCs represent the dilute turbulent type of gravity flows that occur during explosive volcanic eruptions; their hazard is the result of their mobility and the capability to laterally impact buildings and infrastructures and to transport variable amounts of volcanic ash along the path. Starting from data coming from the analysis of deposits formed by DPDCs, PYFLOW_2.0 calculates the flow properties (e.g., velocity, bulk density, thickness) and impact parameters (dynamic pressure, deposition time) at the location of the sampled outcrop. Given the inherent uncertainties related to sampling, laboratory analyses, and modeling assumptions, the program provides ranges of variations and probability density functions of the impact parameters rather than single specific values; from these functions, the user can interrogate the program to obtain the value of the computed impact parameter at any specified exceedance probability. In this paper, the sedimentological models implemented in PYFLOW_2.0 are presented, program functionalities are briefly introduced, and two application examples are discussed so as to show the capabilities of the software in quantifying the impact of the analyzed DPDCs in terms of dynamic pressure, volcanic ash concentration, and residence time in the atmosphere. The software and user’s manual are made available as a downloadable electronic supplement

Beyond (and back to) Palatini quadratic gravity and inflation

We study single-field slow-roll inflation embedded in Palatini $F(R)$ gravity where $F(R)$ grows faster than $R^2$. Surprisingly, the consistency of the theory requires the Jordan frame inflaton potential to be unbounded from below. Even more surprisingly, this corresponds to an Einstein frame inflaton potential bounded from below and positive definite. We prove that for all such Palatini $F(R)$'s, there exists a universal strong coupling limit corresponding to a quadratic $F(R)$ with the wrong sign for the linear term and a cosmological constant in the Jordan frame. In such a limit, the tensor-to-scalar ratio $r$ does not depend on the original inflaton potential, while the scalar spectral index $n_s$ does. Unfortunately, the system is ill-defined out of the slow-roll regime. A possible way out is to upgrade to a $F(R,X)$ model, with $X$ the Jordan frame inflaton kinetic term. Such a modification essentially leaves the inflationary predictions unaffected.Comment: 21 pages, 7 figures, revised version: added a section on $F(R,X)$ models, title, abstract and conclusions revise

Stroller Attachment to Promote Natural Coordination in Running Gait

It is known from prior research that when a subject’s hands are held in a fixed position whilst running, the lower body compensates, therefore creating additional stresses on the lower back. Due to this, it is theorized that if full range of motion is allowed in the arms while running, the rest of the body will move more comfortably and without compensation. This would reduce the risk of a mechanopathological injury from consistently running with fixed arms, such as when using a stroller. In addition, if an energy conversion system is applied, the momentum from the runner\u27s arm swing can be further added to the stroller\u27s motion to create a more efficient and natural run with the stroller. To research this problem, the group designed and built a stroller attachment that simulates the motion of an elliptical to allow the user full range of arm motion. Testing of the attachments on the stroller to validate the ergonomically designed handlebars, as well as comfortability is being performed. A comparison of the gait cycle will also be tested to see variance from running freely, constrained, and using the stroller attachments. Once finished, this research will be applied to better the jogging stroller attachments so as to create an efficient and cost effective device