When the signal is in the noise: Exploiting Diffix's Sticky Noise

Anonymized data is highly valuable to both businesses and researchers. A large body of research has however shown the strong limits of the de-identification release-and-forget model, where data is anonymized and shared. This has led to the development of privacy-preserving query-based systems. Based on the idea of "sticky noise", Diffix has been recently proposed as a novel query-based mechanism satisfying alone the EU Article~29 Working Party's definition of anonymization. According to its authors, Diffix adds less noise to answers than solutions based on differential privacy while allowing for an unlimited number of queries. This paper presents a new class of noise-exploitation attacks, exploiting the noise added by the system to infer private information about individuals in the dataset. Our first differential attack uses samples extracted from Diffix in a likelihood ratio test to discriminate between two probability distributions. We show that using this attack against a synthetic best-case dataset allows us to infer private information with 89.4% accuracy using only 5 attributes. Our second cloning attack uses dummy conditions that conditionally strongly affect the output of the query depending on the value of the private attribute. Using this attack on four real-world datasets, we show that we can infer private attributes of at least 93% of the users in the dataset with accuracy between 93.3% and 97.1%, issuing a median of 304 queries per user. We show how to optimize this attack, targeting 55.4% of the users and achieving 91.7% accuracy, using a maximum of only 32 queries per user. Our attacks demonstrate that adding data-dependent noise, as done by Diffix, is not sufficient to prevent inference of private attributes. We furthermore argue that Diffix alone fails to satisfy Art. 29 WP's definition of anonymization. [...

The interplay between high energy physics and cosmology: an example

Cosmology and high energy physics are two closely connected areas. In this lecture I present an example of their rich interplay.Comment: Invited talk at the DPU workshop: The density fluctuations in the Universe: Beyond the inflationary paradigm (Dimokritos, Athens 2004) (see http://physics.ntua.gr/dpu/). 8 two column page

Supersymmetric Inflation with the Ordinary Higgs?

We consider a model of D-term inflation in which the inflaton coincides with the standard Higgs doublet. Non-renormalizable terms are controlled by a discrete R-symmetry of the superpotential. We consider radiative corrections to the scalar potential and find that Higgs inflation in the slow-roll approximation is viable and consistent with CMB data, although with a rather large value of the non-renormalizable coupling involved.Comment: 7 pages, 1 figure, published version, comments and reference added, typos and factor of 2 corrected

Halo Occupation Distribution of Emission Line Galaxies: fitting method with Gaussian Processes

The halo occupation distribution (HOD) framework is an empirical method to describe the connection between dark matter halos and galaxies, which is constrained by small scale clustering data. Efficient fitting procedures are required to scan the HOD parameter space. This paper describes such a method based on Gaussian Processes to iteratively build a surrogate model of the posterior of the likelihood surface from a reasonable amount of likelihood computations, typically two orders of magnitude less than standard Monte Carlo Markov chain algorithms. Errors in the likelihood computation due to stochastic HOD modelling are also accounted for in the method we propose. We report results of reproducibility, accuracy and stability tests of the method derived from simulation, taking as a test case star-forming emission line galaxies, which constitute the main tracer of the Dark Energy Spectroscopic Instrument and have so far a poorly constrained galaxy-halo connection from observational data

Identificação dos agentes agressivos e das patologias em pisos industriais de frigorífico de suínos

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-graduação em Engenharia CivilNos frigoríficos de suínos, observa-se a presença de muitos problemas existentes nos pisos, como buracos, rachaduras, desgastes acentuados, quebras, descolamentos de camadas, formação de pó, deterioração de juntas e outros que são formas de patologias ocasionadas por diferentes agentes agressivos como urina, fezes, sangue, gordura, sal, águas quente e fria, produtos químicos do processo de produção e ainda aqueles empregados nas diversas atividades de limpeza como detergentes e sanitizantes, além de meios mecânicos utilizados em operações de movimentação de cargas, que são altamente abrasivos e de impacto danificando as superfícies. O trabalho teve por objetivo identificar e caracterizar esses agentes presentes nas instalações, além de sugerir indicação de materiais para mais bem resistir aos meios agressivos, minimizando-se a degradação dos pisos. Observa-se que em grande parte dos setores da indústria, não é possível mudar as condições ambientais devido aos processos de produção, então a alternativa é melhorar os procedimentos para a confecção e uso de novos pisos, criando-se mecanismos que possam barrar esses agentes. Levando-se em consideração os dados obtidos na pesquisa, foi sugerida uma classificação dada pelo grau de agressividade, em função dos agentes agressivos atuantes nos pisos em cada setor. A partir desta classificação foi apresentada uma proposta para utilização de revestimentos especiais que aplicados sobre os pisos de concreto suportariam as agressividades impostas. Os resultados mostraram que esses revestimentos usados conforme sugeridos neste trabalho, servem para a obtenção de pisos com melhor qualidade, proporcionando maior durabilidade, pois têm grande capacidade de resistência química e física. Assim terá maior vida útil com menor número de intervenções para reformas, diminuindo-se a quantidade de paradas técnicas para se efetuar pequenos reparos ou substituições. Desta forma, conclui-se que o uso desses materiais reduz os custos com manutenções além de eliminar grande parte das patologias verificadas, o que facilita os processos de produção e atividades internas de movimentação das matérias-primas e de produtos acabados. Tem-se também como resultados uma acentuada redução dos problemas de contaminação microbiológica nos ambientes e uma significativa melhora na aparência estética dos pisos industriais. In swine slaughterhouses, many problems are observed in relation to the floors, such as holes, cracks, accentuated wear, breaks, detachment of layers, formation of dust, deterioration of joins and others which are types of pathologies caused by different aggressive agents such as urine, feces, blood, fat, salt, hot and cold water, chemical products from the production process and also those employed in the various cleaning activities, such as detergents and sanitizers, besides mechanical means used in operations involving the movement of loads, which are highly abrasive and have a damaging effect on surfaces. This study aimed to identify and characterize the agents present in the installations, and to recommend materials to better resist the aggressive agents, minimizing the degradation of the floors. In most sectors of slaughterhouses, it is not possible to change the environmental conditions due to the production processes, thus, the alternative is to better the procedures for the making and use of new floors, creating mechanisms which can bar these agents. Taking into consideration the data obtained in this research, a classification based on the degree of aggressiveness, as a function of the aggressive agents acting on the floors in each sector, was suggested. According to this classification, a proposal for the use of special coverings which, when applied over the concrete floors, would endure the aggressive intruders, was presented. The results showed that these coverings, when used according to the recommendations of this study, lead to the obtainment of better quality floors, with higher durability, since they have a great chemical and physical resistance capacity. Thus, they will have a longer useful life with less intervention for improvements, reducing the quantity of technical stoppages required to carry out small repairs or replacements. It is concluded that the use of these materials reduces the maintenance costs and also eliminates a large number of the pathologies verified, which facilitates the production processes and also the internal activities of the movement of raw materials and finished products. Other results were a clear reduction in the microbiological contamination problems of these environments and a significantly better esthetic appearance of industrial floors

Prospectives

Tiré de: Prospectives, vol. 11, no 4, oct. 1975Titre de l'écran-titre (visionné le 24 janv. 2013

Les villes-usines face à la problématique environnementale : réflexions à partir de l’exemple de l’agglomération dunkerquoise

Fortement dépendantes de secteurs industriels en déclin ou disparus, les villes-usines sont confrontées depuis quelques années à des problématiques de reconversion et de (ré)attractivité. Dans ce cadre, la dimension environnementale, largement sacrifiée pendant les années de croissance, constitue un enjeu majeur, renforcé encore par la perspective de la transition écologique et sociale. Dans cet article, nous tentons de formuler quelques pistes de réflexion pour esquisser les contours d’une articulation de ces villes-usines à une reconsidération du rôle et de l’importance de l’environnement naturel dans le développement territorial. Pour cela, nous prenons appui sur l’exemple du territoire urbano-industriel de l’agglomération dunkerquoise, dont nous tirons des enseignements mis en perspective avec le cas particulier des villes-usines.Highly dependent on declining or disappeared industrial sectors, company towns have been faced in recent years with problems of renovation and (re)attractiveness. In this context, the environmental dimension, which was largely surrendered during the years of growth, is a major challenge, further reinforced by the perspective of ecological and social transition. In this article, our main objective is to expose some avenues for reflection to outline the contours of an articulation of these company towns with a reconsideration of the role and importance of the natural environment in their territorial development. In fact, we use the example of the urban-industrial territory of Dunkerque (France), from which we draw lessons put into perspective with the particular case of factory towns.Die von rückläufigen oder schwindenden Industriebereichen stark abhängigen Fabrikstädte sind seit einigen Jahren mit Problemen der Umstellung und (Wieder-) Attraktivität konfrontiert. In diesem Zusammenhang stellt die Umweltdimension, die in den Jahren des Wachstums weitgehend geopfert wurde, eine große Herausforderung dar, die durch die Aussicht auf einen ökologischen und sozialen Wandel noch verstärkt wird. In diesem Artikel versuchen wir, einige Gedankengänge zu formulieren, um die Konturen einer Artikulation dieser Fabrikstädte zu skizzieren und die Rolle und Bedeutung der natürlichen Umwelt für die territoriale Entwicklung zu überdenken. Dafür stützen wir uns auf das Beispiel des städtischen Industriegebiets der Agglomeration Dünkirchen, aus dem wir Lehren ziehen, die mit dem besonderen Fall der Fabrikenstädte in Beziehung gesetzt werden

The role of dihydropydine-sensitive Ca2 + channels in stimulus-evoked catecholamine release from chemoreceptor cells of the carotid body

Producción CientíficaAhatraet-The present study utilized an in vitro preparation of the rabbit carotid body, with tissue catecholamine stores labeled by incubation with ‘H-tyrosine. The goal was to characterize pharmacologically the vol~g~~n&nt Ca*+ channels present in the type I (glomus) cells of this arterial chemoreceptor organ, and to elucidate their role as pathways for Ca2+ entry. We found that release of ‘H-dopamine induced by high external potassium was over 95% dependent on external cakium concentration and that this release was 9&100% inhibited by the dihydropy~~ne antagonists, nisoldipine and nitrendipine, and was potentiated by the dihydropyridine agonist, BayK 8444. Therefore, any stimulus-induced, cakiumdependent release of 3H-dopamine that was inhibited by nisoldipine and potentiated by BayK 8644, was considered to be supported by Ca2+ entry into the cells via voltage-dependent Ca2+ channels. Significant differences were observed in the release of ‘H-dopamine induced by 75 vs 25mM K+. On prolonged stimulation, release induced by 75 mM K+ was large and transient, whilst that induced by 25 mM K+, although more moderate, was sustained. The release elicited by 75 mM K+ was inhibited approximately 90% by 1.5 mM Co2+ or 625 nM nisoldipine, while release by 25 mM K+ was completely blocked by 0.6 mM Co*+ or 125 nM nisoldipine. Low PO,-induced release of 3H-dopamine was 95% dependent on Ca*+, and was inhibited by nisoldipine (625 nM) in a manner inversely proportional to the intensity of hypoxic stimulation, i.e. 79% inhibition at a PO, of 49 Torr, and 20% inhibition at PO2 of 0 Torr. BayK 8644 potentiatcd the release induced by moderate hypoxic stimuli. Release elicited by high PCOJlow pH, or by Na+-propionate or dinitrophenol~n~ining solutions, was approximately 80% Ca’+-dependent, and the ~hyd~y~din~ failed to modify this release. It is concluded that type I mlls possess vol~~de~nd~t Ca ‘+ channels sensitive to the dihydropy~dines, which in agreement with previous el~trophysiolo~~l data should be defined as L-type Ca*+ channels. Calcium entry which supports the release of 3H-dopamine elicited by moderate hypoxia should occur mainly through these channels while the release induced by strong hypoxic stimuli will be SetNed by Ca2+ entry which occurs in part via voltage-dependent Ca2+ channels, and in part through an additional pathway, probably a Na+/Ca2+ exchanger. The insensitivity to dihydropyridines of the release of )H-dopamine induced by high 1DC02/low pH, Na+-propionate and dinitrophenol may indicate a complete loss of efficacy of the drugs to modulate Ca 2+ channels under these conditions or more likely, that other mechanisms are activated, probably the Na+-Ca’+ exchanger. Carotid body (CB) chemoreceptors are thought to be composite receptors in which the type I (glomus) cells detect changes in blood PO,, PCO, and pH and respond with the release of neurotransmitt~ to activate the closely apposed chemosensory nerve terminals.~** One such neurotransmitter that has received considerable attention in recent years and is known to be released by the type I cells is dopamine (DA). This biogenic amine has been shown to be released in proportion to both the intensity of stimulation and the resultant sensory discharge recorded from the carotid sinus nerve $To whom correspondence should be addressed. Abbr~~~~~~ CB, carotid body; CSN, carotid sinus nerve; DA, dopamine; DHMA, dihydrox~~delic acid, DOPAC, dihydroxyphenyl acetic acid; NE, norepinephrine. (CSN). This relationship between stimulu

Intracellular Ca2 + deposits and catecholamine secretion by chemoreceptor cells of the rabbit carotid body

Producción CientíficaThe pívotal role of íntracellular free [Ca2+] fluctuatíons in the control of cellular functíons such as contraction and secretíon, íncludíng the release of neurotransmítters, was recognized many decades ago (see Rubín, 1982). More recently, the list of cellular functíons tríggered or modulated by the levels of Ca2+¡ has grown enormously. Addítional functíons regulated by [Ca2+)¡ include neuronal excítabílity, synaptic plastícíty, gene ex­ pressíon, cellular metabolísm, cell dívísíon and dífferentíatíon, and programmed cell dead (Míller, 1991; Clapham, 1995). Parallelíng the growth in this líst of Ca2+-controlled func­ tíons, a multíplicity of cellular mechanísms aimed at maintaining resting free [Ca2+)¡ in the range of l 00 nM for most cells has been described, allowing increases in Ca2+¡ levels that are specific in their magnitude, time course and spatial distributíon, accordíng to the cell function activated (Toescu, 1995). Since Ca2+ cannot be metabolized, cells regulate theír cytoplasmic levels of free Ca2+ through numerous bínding proteíns and influx and efflux mechanisms (Fíg 1). Ca2+ ínflux to cell cytoplasm from the extracellular milieu occurs vía voltage or receptor operated channels or vía yet ill-defined capacítatíve pathways; the Na+/Ca 2+ exchanger can also produce in sorne círcumstances net ínflux of Ca2+ (Míller, 1991; Clapham, 1995). Ca2+ ef­ flux to the extracellular space occurs against electrochemical gradíents, and thereby the pumpíng out of Ca2+ is directly (Caz+ pump) or indirectly (Na+/Ca2+) coupled to the hy­ drolysis of ATP

A proposal for a method of forensic medical evaluation of the aesthetic damage of scarring

Una de las principales actividades en el ámbito médico forense es la valoración del perjuicio estético. Son diferentes los métodos recogidos en la literatura para efectuar esta valoración, pero sólo tres son dirigidos exclusivamente al daño estético ocasionado por cicatrices. Proponemos en este trabajo un método para la valoración médico legal del perjuicio estético por cicatrices: inicialmente se valoran y puntúan tres parámetros: zona del cuerpo donde está la cicatriz, longitud en centímetros y distancia a la que se ve la cicatriz. Cada uno de estos parámetros se pondera de forma diferente en la valoración global del perjuicio estético. El resultado podrá incrementarse o reducirse en función del grado de deformidad y del color de la cicatriz, aplicando una tabla cruzada. La puntuación final (sobre 100) se puede dividir por dos para asimilarla al RD Legislativo 8/2004 que contiene el baremo, actualmente vigente para la valoración de secuelas de un accidente de tráfico.One of the main activities in the medical forensic area is the evaluation of aesthetic damage. There are different methods reported in the literature to perform this evaluation, but only three are intended solely for the aesthetic damage caused by scarring. We propose, in this paper, a method for evaluation the damage forensic aesthetic scars: initially three parameters are evaluated and given a numerical value: the area of the body, the length in cm and distance at which the scar is seen. Each of these parameters is pondered differently in the overall evaluation of aesthetic damage. The result may be increased or decreased depending on the degree of deformity and scar color, applying a crossed table. The final result (out of 100) can be divided by two to assimilate the RDL 8/2004 containing the scale, currently applicable to the assessment of the consequences of an accident