PadChest: A large chest x-ray image dataset with multi-label annotated reports

We present a labeled large-scale, high resolution chest x-ray dataset for the automated exploration of medical images along with their associated reports. This dataset includes more than 160,000 images obtained from 67,000 patients that were interpreted and reported by radiologists at Hospital San Juan Hospital (Spain) from 2009 to 2017, covering six different position views and additional information on image acquisition and patient demography. The reports were labeled with 174 different radiographic findings, 19 differential diagnoses and 104 anatomic locations organized as a hierarchical taxonomy and mapped onto standard Unified Medical Language System (UMLS) terminology. Of these reports, 27% were manually annotated by trained physicians and the remaining set was labeled using a supervised method based on a recurrent neural network with attention mechanisms. The labels generated were then validated in an independent test set achieving a 0.93 Micro-F1 score. To the best of our knowledge, this is one of the largest public chest x-ray database suitable for training supervised models concerning radiographs, and the first to contain radiographic reports in Spanish. The PadChest dataset can be downloaded from http://bimcv.cipf.es/bimcv-projects/padchest/

On the lower semicontinuous envelope of functionals defined on polyhedral chains

In this note we prove an explicit formula for the lower semicontinuous envelope of some functionals defined on real polyhedral chains. More precisely, denoting by $H \colon \mathbb{R} \to \left[ 0,\infty \right)$ an even, subadditive, and lower semicontinuous function with $H(0)=0$, and by $\Phi_H$ the functional induced by $H$ on polyhedral $m$-chains, namely \Phi_{H}(P) := \sum_{i=1}^{N} H(\theta_{i}) \mathcal{H}^{m}(\sigma_{i}), \quad\mbox{for every }P=\sum_{i=1}^{N} \theta_{i} [[ \sigma_{i} ]] \in\mathbf{P}_m(\mathbb{R}^n), we prove that the lower semicontinuous envelope of $\Phi_H$ coincides on rectifiable $m$-currents with the $H$-mass \mathbb{M}_{H}(R) := \int_E H(\theta(x)) \, d\mathcal{H}^m(x) \quad \mbox{ for every } R= [[ E,\tau,\theta ]] \in \mathbf{R}_{m}(\mathbb{R}^{n}). Comment: 14 page

Calibration of a visual method for the analysis of the mechanical properties of historic masonry

The conservation and preservation of historic buildings affords many challenges to those who aim to retain our building heritage. In this area, the knowledge of the mechanical characteristics of the masonry material is fundamental. However, mechanical destructive testing is always expensive and time-consuming, especially when applied to masonry historic structures. In order to overcome such kind of problems, the authors of this article, proposed in 2014 a visual method for the estimation of some critical mechanical parameters of the masonry material. Based on the fact that the mechanical behavior of masonry material depends on many factors, such as compressive or shear strength of components (mortar and masonry units), unit shape, volumetric ratio between components and stone arrangement, that is the result of applying a series of construction solutions which form the "rule of art". Taking into account the complexity of the problem due to the great number of variables, and being on-site testing a not-always viable solution, a visual estimate of the mechanical parameters of the walls can be made on the basis of a qualitative criteria evaluation. A revision of this visual method is proposed in this paper. The draft version of new Italian Building Code have been used to re-calibrate this visual method and more tests results have been also considered for a better estimation of the mechanical properties of masonry

Plant surfaces as vehicles of Bacillus cereus responsible of human food poisoning

• Introduction A major concern in food safety is the contamination of fresh and stored food with spoiling bacteria that provoke human poisoning. Bacillus cereus is a common food-borne pathogen responsible of important poisoning outbreaks and severe bacteraemia and septicaemia. Poisoning caused by B. cereus is classified in two main categories: emetic and diarrheic. The emetic poisoning is correlated to the production of cereulide. This toxin is very heat stable, and it can be produced in the food contaminated by B. cereus cells. Diarrheic poisoning is provoked by the enterotoxin hemolysin BL, the non-hemolytic enterotoxin and the cytotoxin K. • Objective To study the interaction of B. cereus with plants as a bacteria reservoir, and in ready-to-eat fruits and vegetables. • Materials & Methods A collection of strains implicated in food-borne outbreaks were tested in vitro for a battery of phenotypes related to bacterial multicellular behaviour and thus interaction with host. 1. Solid or liquid media were used to study biofilm formation, motility or adhesion to surfaces. 2. Leaves, fruits and vegetables (melon leaf, cucumber leaf and fruit and endive) were used to study the persistence of B. cereus over time and their distribution and organization by electron microscopy. • Results All the strains behaved similarly in vitro, only some persisted on plant surfaces. Among them, the emetic strain AH187 was selected because bacterial cells persisted on a concentration of 104-105 CFU per gram of leaf, vegetable or fruit, with a sporulation rate of 40%. The electron microscopy images showed the organization of bacteria in well-developed biofilms with visible extracellular matrix. Finally, mass spectrometry analysis proved the presence of some isoforms of cereluide on the different surfaces. • Conclusion The fact that cells of B. cereus persist in leaf surface mainly as vegetative cells are indicative of their ability to adapt to the physico-chemical changeable phyllosphere, and thus to produce the emetic toxin cereulide. The presence of spores, and the formation of biofilms can be indicative of the versatile adhesive properties of this strain to diverse surfaces. Altogether are supportive of the importance of plant surfaces either as reservoir of bacterial cells or as vehicles for further contamination and food poisoning.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

A minimum cross entropy model to generate disaggregated agricultural data at the local level

This work presents an entropy approach to disaggregate agricultural data at a local level. It comprises two different steps. In a first one, an information prior at disaggregated level based on experts’ opinions, available cartography of land use and biophysical data is created. In a second step, it’s used a minimum cross entropy process in order to manage these information inputs and to guaranty a solution compatible with all the different restrictions. The model was applied to the region of Algarve in the year of 1999, in order to disaggregate the data at the pixel and county level. Results show that the model was able to provide some satisfactory results since the estimated values obtained for the different areas revealed a good approximation to the true values. These results were then analyzed and provided a new insight about the policies’ consequences in the territory.Minimum cross entropy, data disaggregation, local level, Algarve, agricultural policies, Agricultural and Food Policy, C11, C81, Q15, R14,

Recovery of Incomplete Data of Statistical Livestock Number Applying an Entropy Approach

Livestock Production/Industries, Research Methods/ Statistical Methods,

Macroscopic elastic anisotropy in tough ceramics from the single crystal elastic behaviour

The modern techniques for engineering analysis are based on a deep understanding of the proportional relationship between stress and strain and the description in terms of isotropic elastic constants, in many cases, is enough. In anisotropic materials the knowledge of the elastic constants is important for the manufacturing process and for micro mechanical modelling behaviour of the material to develop the new composite materials. Theoretical calculations of elastics constants and anisotropies are applied to tough ceramics ZrO2, HfO2 and in rutile TiO2 and SnO2. Their dependence of the residual hydrostatic stress in the crystal are given. The microscopic elastic anisotropy determined in this work, could be applied in the macro scale in the case the constituent grains have a preferred orientation in the crystal lattice or the grains shape is not spherical (faceted) and it is aligned to a common crystal axis. To cover the case where the grains are distributed at randomly, the Voigt-Reuss-Hill polycrystalline approach is applied to obtain the average values of Young, bulk, shear modules, Poisson coefficient and sound velocity in the transversal and longitudinal modes. These theoretical results, could be useful in the interpretation of experimental results obtained with the method known as diffraction elastic constant (DEC).Fil: Caravaca, Maria de Los Angeles Dominga. Universidad Nacional del Nordeste. Facultad de Ingeniería; ArgentinaFil: Casali, Ricardo Antonio. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; ArgentinaFil: Ponce Altamirano, Claudio Ariel. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Naturalness of MSSM dark matter

There exists a vast literature examining the electroweak (EW) fine-tuning problem in supersymmetric scenarios, but little concerned with the dark matter (DM) one, which should be combined with the former. In this paper, we study this problem in an, as much as possible, exhaustive and rigorous way. We have considered the MSSM framework, assuming that the LSP is the lightest neutralino, $\chi_1^0$, and exploring the various possibilities for the mass and composition of $\chi_1^0$, as well as different mechanisms for annihilation of the DM particles in the early Universe (well-tempered neutralinos, funnels and co-annihilation scenarios). We also present a discussion about the statistical meaning of the fine-tuning and how it should be computed for the DM abundance, and combined with the EW fine-tuning. The results are very robust and model-independent and favour some scenarios (like the h-funnel when $M_{\chi_1^0}$ is not too close to $m_h/2$) with respect to others (such as the pure wino case). These features should be taken into account when one explores "natural SUSY" scenarios and their possible signatures at the LHC and in DM detection experiments.Comment: 28 pages, 18 figures. References added, matches JHEP published versio