Familias de curvas elípticas adecuadas para Criptografía Basada en la Identidad

La Criptografía Basada en la Identidad hace uso de curvas elípticas que satisfacen ciertas condiciones (pairingfriendly curves), en particular, el grado de inmersión de dichas curvas debe ser pequeño. En este trabajo se obtienen familias explicitas de curvas elípticas idóneas para este escenario. Dicha criptografía está basada en el cálculo de emparejamientos sobre curvas, cálculo factible gracias al algoritmo de Miller. Proponemos una versión más eficiente que la clásica de este algoritmo usando la representación de un número en forma no adyacente (NAF).Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad con los proyectos MTM2010-21580-C02-01/02 y MTM2010-16051

The characteristic numbers of the variety of P3

In this note we obtain, phrased in present day geometric and computational frameworks, the characteristic numbers of the family Unod of non–degenerate nodal plane cubics in P3, first obtained by Schubert in his Kalk¨ul der abz¨ahlenden Geometrie. The main geometric contribution is a detailed study of a variety Xnod, which is a compactification of the family Unod, including the boundary components (degenerations) and a generalization to P3 of a formula of Zeuthen for nodal cubics in P2. The computations have been carried out with the OmegaMath intersection theory module WIT

Bone-Mimicking Injectable Gelatine/Hydroxyapatite Hydrogels

[EN] Bioactive synthetic hydrogels have emerged as promising materials because they can provide molecularly tailored biofunctions and adjustable mechanical properties. To mimic the mineralogical and organic components of the natural bone, hydroxyapatite and a tyramine conjugate of gelatine were combined in this study. The effect of various amounts of in situ synthesized hydroxyapatite in gelatine-tyramine on the morphology and physical properties of injectable hydrogels was investigated. Mineralogical identification confirmed successful precipitation of in situ formed hydrox yapatite. Better distribution of hydroxyapatite crystal agglomerates within modified gelatine was found at 5 % of hydroxyapatite, which could be responsible for increased storage modulus with respect to pure gelatine hydrogel. Prepared composite hydrogels are non-toxic and support the proliferation of Hek293 cells.The authors are grateful for the financial support of the Spanish Ministry of Economy and Competitiveness through the MAT2016-76039-C4-1-R project (including Feder funds) and the Croatian Science Foundation under the project IP-2014-09-3752.Rogina, A.; Sandrk, N.; Teruel Biosca, L.; Antunovic, M.; Ivankovic, M.; Gallego Ferrer, G. (2019). Bone-Mimicking Injectable Gelatine/Hydroxyapatite Hydrogels. Chemical and Biochemical Engineering Quarterly Journal. 33(3):325-335. https://doi.org/10.15255/CABEQ.2019.1663S32533533

Algorithms and cryptographic protocols using elliptic curves

En els darrers anys, la criptografia amb corbes el.líptiques ha adquirit una importància creixent, fins a arribar a formar part en la actualitat de diferents estàndards industrials. Tot i que s'han dissenyat variants amb corbes el.líptiques de criptosistemes clàssics, com el RSA, el seu màxim interès rau en la seva aplicació en criptosistemes basats en el Problema del Logaritme Discret, com els de tipus ElGamal. En aquest cas, els criptosistemes el.líptics garanteixen la mateixa seguretat que els construïts sobre el grup multiplicatiu d'un cos finit primer, però amb longituds de clau molt menor. Mostrarem, doncs, les bones propietats d'aquests criptosistemes, així com els requeriments bàsics per a que una corba sigui criptogràficament útil, estretament relacionat amb la seva cardinalitat. Revisarem alguns mètodes que permetin descartar corbes no criptogràficament útils, així com altres que permetin obtenir corbes bones a partir d'una de donada. Finalment, descriurem algunes aplicacions, com són el seu ús en Targes Intel.ligents i sistemes RFID, per concloure amb alguns avenços recents en aquest camp.The relevance of elliptic curve cryptography has grown in recent years, and today represents a cornerstone in many industrial standards. Although elliptic curve variants of classical cryptosystems such as RSA exist, the full potential of elliptic curve cryptography is displayed in cryptosystems based on the Discrete Logarithm Problem, such as ElGamal. For these, elliptic curve cryptosystems guarantee the same security levels as their finite field analogues, with the additional advantage of using significantly smaller key sizes. In this report we show the positive properties of elliptic curve cryptosystems, and the requirements a curve must meet to be useful in this context, closely related to the number of points. We survey methods to discard cryptographically uninteresting curves as well as methods to obtain other useful curves from a given one. We then describe some real world applications such as Smart Cards and RFID systems and conclude with a snapshot of recent developments in the field

Evaluation of the IL-Phoenix chemistry electrolyte analyser

This paper reports an evaluation of the IL-Phoenix Chemistry/Electrolyte Analyser; the evaluation was carried out in accordance with internationally recognized guidelines. The evaluation was performed in three steps: evaluation in routine conditions; assessment of interferences; and study of practicability. Seven constituents were studied under routine working conditions. Within-run imprecision rangedfrom 0.6% (CV) for chloride to 3.1% (CV) for glucose. Between-run imprecision ranged from 0.9% for sodium to 6.0% (CV) for urea. Sample-related carryover was not significant. The relative inaccuracy was acceptable; drift was negligible; linearity was agreed with the range showed by the supplier. Haemoglobin produced negative interferences with sodium and chloride. Turbidity interfered negatively with sodium, chloride, potassium and total calcium, andpositively with glucose. Bilirubin showed a negative interference with sodium, chloride and creatinine

Modelling the enantioresolution capability of cellulose tris(3,5-dichlorophenylcarbamate) stationary phase in reversed phase conditions for neutral and basic chiral compounds

[EN] To the best of our knowledge, the prediction of the enantioresolution ability of polysaccharides-based stationary phases in liquid chromatography for structurally unrelated compounds has not been previously reported. In this study, structural information of neutral and basic compounds is used to model their enantioresolution levels obtained from an immobilised cellulose tris(3,5-dichlorophenylcarbamate) stationary phase in reversed phase conditions. Thirty-four structurally unrelated chiral drugs and pesticides, from seven families, are studied. Categorical enantioresolution levels (RsC, 0 = no baseline enantioresolution and 1 = baseline enantioresolution) are established from the experimental enantioresolution values obtained at a fixed experimental conditions. From 58 initial structural variables, three topological parameters (two of them connected to the chiral carbon), and six molecular descriptors (one of them also related with the chiral carbon), are selected after a discriminant partial least squares refinement process. The molar total charge of the molecule at the working pH is the most important variable. The relationships between RsC and the most important structural variables and the drug/pesticide family are evaluated. An explicit model is proposed to anticipate the RsC levels, which provides 100% of correct anticipations. A criterion is introduced to alert about the compounds that should not be anticipated.The authors acknowledge the Spanish Ministerio de Economia y Competitividad (MINECO) and the European Regional Development Fund (ERDF) for the financial support (Project CTQ2015-70904-R, MINECO/FEDER, UE).Martin-Biosca, Y.; Escuder-Gilabert, L.; Medina-Hernandez, MJ.; Sagrado Vives, S. (2018). Modelling the enantioresolution capability of cellulose tris(3,5-dichlorophenylcarbamate) stationary phase in reversed phase conditions for neutral and basic chiral compounds. Journal of Chromatography A. 1567:111-118. https://doi.org/10.1016/j.chroma.2018.06.061S111118156

An Elliptic Curve Based Homomorphic Remote Voting System

A remote voting system allows participants to cast their ballots through the Internet. Remote voting systems based on the use of homomorphic public key cryptography have proven to be a good option for carrying out simple elections with a reduced amount of candidates. In this paper, we present a new system that makes use of the additive homomorphic capabilities of the Elliptic Curve ElGamal (EC-ElGamal) cryptosystem. All the stages of the system are described together with an experimental analysis section which provides an assessment on the type of election our system would be suitable for.Research of the authors was supported in part by grants MTM2010-21580-C02-01 (Spanish Ministerio de Ciencia e Innovación), 2014SGR-1666 (Generalitat de Catalunya) and IPT-2012-0603-430000 (Spanish Ministerio de Economía y Competitividad)

Combining statistical learning with metaheuristics for the multi-depot vehicle routing problem with market segmentation

In real-life logistics and distribution activities it is usual to face situations in which the distribution of goods has to be made from multiple warehouses or depots to the nal customers. This problem is known as the Multi-Depot Vehicle Routing Problem (MDVRP), and it typically includes two sequential and correlated stages: (a) the assignment map of customers to depots, and (b) the corresponding design of the distribution routes. Most of the existing work in the literature has focused on minimizing distance-based distribution costs while satisfying a number of capacity constraints. However, no attention has been given so far to potential variations in demands due to the tness of the customerdepot mapping in the case of heterogeneous depots. In this paper, we consider this realistic version of the problem in which the depots are heterogeneous in terms of their commercial o er and customers show di erent willingness to consume depending on how well the assigned depot ts their preferences. Thus, we assume that di erent customer-depot assignment maps will lead to di erent customer-expenditure levels. As a consequence, market-segmentation strategies need to be considered in order to increase sales and total income while accounting for the distribution costs. To solve this extension of the MDVRP, we propose a hybrid approach that combines statistical learning techniques with a metaheuristic framework. First, a set of predictive models is generated from historical data. These statistical models allow estimating the demand of any customer depending on the assigned depot. Then, the estimated expenditure of each customer is included as part of an enriched objective function as a way to better guide the stochastic local search inside the metaheuristic framework. A set of computational experiments contribute to illustrate our approach and how the extended MDVRP considered here diré in terms of the proposed solutions from the traditional one.Peer ReviewedPreprin

Efectos de la alteración endocrina durante la gestación: una revisión sistemática

Los alteradores endocrinos son contaminantes ambientales, naturales y sintéticos, ubicuos, que pueden mimetizar, bloquear o alterar funciones hormonales. La exposición ambiental a estos contaminantes es prácticamente imposible de evitar debido a que están presentes en el aire, en el agua, en los suelos, en los alimentos, y en muchos de los materiales con los que estamos en contacto diariamente, como los plásticos. La gestación supone una etapa de vulnerabilidad para el feto porque su organismo está en proceso de desarrollo y cualquier alteración puede afectar su salud a corto o largo plazo. Hay cierta evidencia de que estas sustancias alteran procesos de crecimiento y diferenciación de tejidos, producen malformaciones y afectan la duración del embarazo. Hasta el momento se conoce algo de sus efectos en la etiología de la criptorquidia, hipospadias y micropene, abortos espontáneos, partos prematuros y el bajo peso al nacimiento, efectos que serán revisados en este documento que quiere aportar una actualización del conocimiento, concentrándose en la epidemiología ambiental y la literatura relacionada. La dificultad para estudiar este tema por la cantidad de factores que intervienen hace que los resultados existentes no sean concluyentes o incluso contradictorios, por lo que es necesario que se siga investigando Abstract.Endocrine disruptors are ubiquitous natural and synthetic environmental pollutants that can mimic, block or disturb normal hormonal function. Environmental exposure to these pollutants is almost impossible to prevent due to their presence in the air,water, soil, food and in many other materials with which we come in contact daily, such as plastics. Foetuses are vulnerable during pregnancy because their organism is in a developmental stage, and any disruption may affect their health in the short and/or long term. There is some evidence that these substances disrupt tissue differentiation and growth processes, cause birth defects and affect the length of pregnancy. In this review we will focus on environmental epidemiology and related literature in order to update current knowledge based on the actual evidence of the effects of these substances on the aetiology of preterm delivery, miscarriages, low birth weight, malformations, cryptorchidism, hypospadias and micropenis. The difficulty in studying this topic is due to the high number of involved factors, which makes the available results inconclusive or even contradictory. Consequently,further research is necessary

Bullous pemphigoid and dipeptidyl peptidase-4 inhibitors: The importance of the pharmacotherapeutic history

A 97-year-old man with a history of type II diabetes mellitus was treated with oral antidiabetic agents. He went to the emergency department after the appearance of blister-like itchy lesions on the abdomen and extremities since 2 months. The examination revealed eczematous lesions on the back, abdomen and extremities along with tense blisters on an erythematous base and serous content (figure 1A). In the blood test carried out, 285?mg/dL glucose and 7.1% eosinophilia stood out, with no associated leucocytosis or other relevant findings. Positive glycosuria (+++) was observed in urinalysis without other alterations. A skin biopsy was performed for histological and immunofluorescence studies that confirmed the diagnosis of bullous pemphigoid (figure 1B–D). Given the poor control of autoimmune blistering disease, possible triggers were looked for and linagliptin intake could be associated with the appearance of skin lesions 1?month earlier. ..