River corridors. A study of spatial configuration along two small rivers in London

Increasing urbanisation puts more pressure on urban river banks in terms of their use as recreational areas as well as their potential for development. Usually, interventions on rivers and riversides are focused on improving their ecological and hydrological aspects. However, to better define objectives for interventions and conservation of urban rivers we need a better understanding of how cities have shaped around rivers and the relationship between these elements and the whole city system. This paper argues that the current interaction between small rivers, urban form and socio-economic outcomes can be investigated through the analysis of the spatial network and land use patterns surrounding them. Using a statistical comparison of the spatial network, land use, demographic data and movement along with an assessment of historic maps, this study analysed the areas surrounding two small London rivers as well as four case studies. The study of the river corridors suggests that their urban form and function are strongly shaped by the connections with the city centre and historical land uses. At the same time, river areas are spatially segregated in comparison with their surrounding areas and they are crossed by routes that are important at city scale while local scale connections are more limited. In addition, the study found that spaces that were better utilised on riversides have a relationship with local centralities in their urban context providing more potential benefits for their communities. A better understanding of the characteristics of river areas and their relationship with the urban environment, particularly the level of accessibility of these natural areas, is relevant to improve policymaking and design interventions that can foster a better relationship between natural resources and the city

Non-Central Beta Type 3 Distribution

Let $X$ and $Y$ be independent random variables, $X$ having a gamma distribution with  shape parameter  $a$ and $Y$ having a non-centralgamma distribution with shape and non-centrality parameters $b$ and$\delta$, respectively. Define $W ={X}/(X + 2 Y)$. Then, the randomvariable $W$ has a non-central beta type 3 distribution, $W\sim\textnormal{NCB3} (a,b;\delta)$. In this article we study several of itsproperties. We also give a multivariate generalization of thenon-central beta type 3 distribution and derive its properties

Combined molecular/continuum modeling reveals the role of friction during fast unfolding of coiled-coil proteins

Coiled-coils are filamentous proteins that form the basic building block of important force-bearing cellular elements, such as intermediate filaments and myosin motors. In addition to their biological importance, coiled-coil proteins are increasingly used in new biomaterials including fibers, nanotubes, or hydrogels. Coiled-coils undergo a structural transition from an a-helical coil to an unfolded state upon extension, which allows them to sustain large strains and is critical for their biological function. By performing equilibrium and out-of-equilibrium all-atom molecular dynamics (MD) simulations of coiledcoils in explicit solvent, we show that two-state models based on Kramers’ or Bell’s theories fail to predict the rate of unfolding at high pulling rates. We further show that an atomistically informed continuum rod model accounting for phase transformations and for the hydrodynamic interactions with the solvent can reconcile two-state models with our MD results. Our results show that frictional forces, usually neglected in theories of fibrous protein unfolding, reduce the thermodynamic force acting on the interface, and thus control the dynamics of unfolding at different pulling rates. Our results may help interpret MD simulations at high pulling rates, and could be pertinent to cytoskeletal networks or protein-based artificial materials subjected to shocks or blasts.Peer ReviewedPostprint (author's final draft

Neutrino-less Double Beta Decay and Particle Physics

We review the particle physics aspects of neutrino-less double beta decay. This process can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). The physics potential of both interpretations is summarized and the consequences of future measurements or improved limits on the half-life of neutrino-less double beta decay are discussed. We try to cover all proposed alternative realizations of the decay, including light sterile neutrinos, supersymmetric or left-right symmetric theories, Majorons, and other exotic possibilities. Ways to distinguish the mechanisms from one another are discussed. Experimental and nuclear physics aspects are also briefly touched, alternative processes to double beta decay are discussed, and an extensive list of references is provided.Comment: 96 pages, 38 figures. Published versio

Use of Multidetector Computed Tomography in the Assessment of Dogs with Pericardial Effusion

Background: Contrast-enhanced multidetector computed tomography ( MDCT) allows high spatial and temporal resolution imaging of cardiac, thoracic, and abdominal structures. Accurate determination of the cause of pericardial effusion ( PE) is essential to providing appropriate treatment and prognosis. Echocardiography and pericardial fluid analysis may not differentiate between causes of PE and cannot identify extracardiac metastasis. Hypothesis/ Objectives: Describe the thoracic and abdominal MDCT findings and evaluate the utility of MDCT to differentiate between neoplastic and nonneoplastic causes of PE in dogs. Animals: Eleven client-owned dogs with PE diagnosed by echocardiography. Methods: Prospective observational study. Transthoracic echocardiography ( TTE), 3-view thoracic radiography, and contrast-enhanced thoracic and abdominal MDCT images were evaluated for the presence of cardiac masses, pulmonary metastases, and abdominal masses. Histopathology in 5 dogs and survival analysis in all dogs were evaluated. Results: A neoplastic cause was identified in 6/ 11 dogs and a nonneoplastic cause was identified in 5/ 11. Cardiac MDCT findings were consistent with TTE findings in all dogs with right atrial ( 5/ 5) and heart base masses ( 1/ 1). Pulmonary metastases were identified in 1/ 11 dogs by thoracic radiography and in 2/ 11 dogs by MDCT. MDCT identified splenic or hepatic lesions consistent with neoplasia in 6/ 11 and 5/ 11 dogs, respectively. Focal MDCT pericardial changes at the pericardiocentesis site were noted in 3/ 11 dogs. Conclusions and Clinical Importance: Multidetector computed tomography did not improve the detection of cardiac masses in dogs with PE over echocardiography. The benefit of MDCT was primarily in the detection of pulmonary metastases and extracardiac lesions using a single imaging modality.Keywords: Cardiac tumors, Echocardiography, Cardiolog

Principal component and Voronoi skeleton alternatives for curve reconstruction from noisy point sets

Surface reconstruction from noisy point samples must take into consideration the stochastic nature of the sample -- In other words, geometric algorithms reconstructing the surface or curve should not insist in following in a literal way each sampled point -- Instead, they must interpret the sample as a “point cloud” and try to build the surface as passing through the best possible (in the statistical sense) geometric locus that represents the sample -- This work presents two new methods to find a Piecewise Linear approximation from a Nyquist-compliant stochastic sampling of a quasi-planar C1 curve C(u) : R → R3, whose velocity vector never vanishes -- One of the methods articulates in an entirely new way Principal Component Analysis (statistical) and Voronoi-Delaunay (deterministic) approaches -- It uses these two methods to calculate the best possible tape-shaped polygon covering the planarised point set, and then approximates the manifold by the medial axis of such a polygon -- The other method applies Principal Component Analysis to find a direct Piecewise Linear approximation of C(u) -- A complexity comparison of these two methods is presented along with a qualitative comparison with previously developed ones -- It turns out that the method solely based on Principal Component Analysis is simpler and more robust for non self-intersecting curves -- For self-intersecting curves the Voronoi-Delaunay based Medial Axis approach is more robust, at the price of higher computational complexity -- An application is presented in Integration of meshes originated in range images of an art piece -- Such an application reaches the point of complete reconstruction of a unified mes

Social Determinants of Health: official stance and critical views

ABSTRACT: The relationship between socioeconomic inequalities and the health-disease process has long been demonstrated. Its study and possibilities for intervention have been submitted to analysis by academic and institutional actors which take more or less critical stances depending on their paradigms. In order to analyze the causes of health inequities and provide some recommendations, the World Health Organization established the Commission on Social Determinants of Health in 2005. Latin American El análisis de la salud desde la perspectiva de los determinantes-determinación social de la salud approaches such as Social Medicine and Collective Health recognize the concern of the World Health Organization, yet they strongly criticize the position taken by the Commission, and organize the discussion around the conceptual, ethical and political action axes; in addition, and unlike the Commission, they propose to search for the causes of inequity and its solution in the meaning of social determination. Likewise, authors such as Vicente Navarro also questioned the Commission’s approach to social determinants. For Navarro, it is not inequalities that kill people, but the actors responsible for those inequalities. He also draws the attention towards the hidden power relationships and the entities responsible for inequity and those benefitting from it. Finally, in order to analyze the social determination and the hierarchical location of the social determinants of a particular problem, the issue of hunger is presented as embedded in a reproduction-determination cycle that makes it possible to locate the specificity and generality that are in constant interplay.RESUMEN: La relación entre las desigualdades socioeconómicas y el proceso salud enfermedad ha sido demostrada desde hace ya algún tiempo. Su estudio y posibilidades de intervención, han sido motivo de análisis de actores académicos e institucionales que asumen posturas según la ideología o corriente de pensamiento en la que se inscriben. Con el ánimo de analizar las causas de las inequidades en salud y hacer algunas recomendaciones, la Organización Mundial de la Salud estableció en el año 2005 la Comisión sobre Determinantes Sociales de la Salud. Perspectivas latinoamericanas como la Medicina Social y la Salud Colectiva reconocen la preocupación de la Organización Mundial de la Salud, sin embargo critican la posición asumida por la Comisión y organizan la discusión alrededor de los ejes conceptual, ético y de acción política, proponiendo, a diferencia de la Comisión, buscar las causas de la inequidad y sus vías de solución en lo que significa la determinación social. Cuestionamientos al enfoque de los determinantes sociales de la Comisión llegaron también desde autores como Vicente Navarro, para quien no son las desigualdades las que matan, sino los responsables de esas desigualdades, llamando la atención sobre las relaciones de poder que se ocultan y sobre los responsables y beneficiarios de la inequidad. Finalmente con el objetivo de analizar la determinación social y la ubicación jerárquica de los determinantes sociales, se presenta el problema del hambre, inscrito en un circuito de reproducción y determinación que permite ubicar la particularidad y la generalidad en permanente interrelación

Genomic epidemiology of NDM-1-encoding plasmids in latin American clinical isolates reveals insights into the evolution of multidrug resistance

Bacteria that produce the broad-spectrum Carbapenem antibiotic NewDelhi Metallo-b-lactamase (NDM) place a burden on health care systems worldwide, due to the limited treatment options for infections caused by them and the rapid global spread of this antibiotic resistancemechanism.Although it is believed that theassociated resistancegenebla NDM-1 originated inAcinetobacter spp., the role of Enterobacteriaceae in its dissemination remains unclear. In this study, we usedwhole genome sequencing to investigate the dissemination dynamics of blaNDM-1-positive plasmids in a set of 21 clinical NDM-1-positive isolates from Colombia and Mexico (Providencia rettgeri, Klebsiella pneumoniae, and Acinetobacter baumannii) aswell as six representative NDM-1-positive Escherichia coli transconjugants. Additionally, the plasmids from three representative P. rettgeri isolates were sequenced by PacBio sequencing and finished. Our results demonstrate the presence of previously reported plasmids from K. pneumoniae and A. baumannii in different genetic backgrounds and geographically distant locations in Colombia. Three new previously unclassified plasmids were also identified in P. rettgeri from Colombia and Mexico, plus an interesting genetic link between NDM-1-positive P. rettgeri from distant geographic locations (Canada, Mexico, Colombia, and Israel) without any reported epidemiological links was discovered. Finally, we detected a relationship between plasmids present in P. rettgeri and plasmids from A. baumannii and K. pneumoniae. Overall, our findings suggest a Russian dollmodel for the dissemination of blaNDM-1 in LatinAmerica,with P. rettgeri playing a central role in this process, andrevealnewinsights into the evolution and disseminationof plasmids carrying such antibiotic resistance genes

VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro