Optimum Watermark Detection and Embedding in Digital Images

This work concentrates on the problem of watermarking of still images using the luminance component, through the use of spread spectrum techniques, both in space (direct sequence spread spectrum or DSSS) and frequency (frequency hopping or FH), following the guidelines of Delaigle et al. (1998). The system described is able to embed watermarks and recover them with zero probability of error. The problem is faced from a statistical detection point of view through the analysis of the density function of the image to be marked. A Cauchy model is found to be very accurate and some tests are performed in order to assess improved detection quality. The resulting system turns out to be easy to encrypt and very robust to filtering and JPEG compression.Peer ReviewedPostprint (published version

Non-noticeable information embedding in color images: marking and detection

One of the problems arising from the use of digital media is the ease of obtaining identical copies of digital images or audio files, allowing manipulation and unauthorized use. Copyright is an effective tool for preserving intellectual property of those documents but authors and publishers need effective techniques preventing copyright modification, due to the straightforward access to multimedia applications and the wider use of digital publications through the WWW. These techniques are generally called watermarking and allow the introduction of side information (i.e. author identification, copyrights, dates, etc.). This work concentrates on the problem of watermarking embedding and optimum detection in color images through the use of spread spectrum techniques, both in space (direct sequence spread spectrum or DSSS) and frequency (frequency hopping). It is applied to RGB and opponent color component representations. Perceptive information is considered in both color systems. Some tests are performed in order to ensure imperceptibility and to assess detection quality of the optimum color detectors.Peer ReviewedPostprint (published version

Data hidding in color images using perceptual models

One of the problems arising from the use of digital media is the ease of identical copies of digital images or audio files, allowing manipulation and unauthorized use. Copyright is an effective tool for preserving intellectual property of those documents but authors and publishers need effective techniques that prevent from copyright modification, due to the straightforward access to multimedia applications and the wider use of digital publications through the www. These techniques are generally called watermarking and allow the introduction of side information (i.e. author identification, copyrights, dates, etc.). This work concentrates on the problem embedding and optimum blind detection of data in color images through the use of spread spectrum techniques, both in space (Direct Sequence Spread Spectrum or DSSS) and frequency (Frequency Hopping). It is applied to RGB and opponent color component representations. Perceptive information is considered in both color systems. Some tests are performed in order to ensure imperceptibility and to assess detection quality of the optimum color detectors.Peer ReviewedPostprint (published version

p-Filiform Zinbiel algebras

The paper deals with the classification of a subclass of finite-dimensional Zinbiel algebras: the naturally graded p-filiform Zinbiel algebras. A Zinbiel algebra is the dual to Leibniz algebra in Koszul sense. We prove that there exists, up to isomorphism, only one family of naturally graded p-filiform Zinbiel algebras under hypothesis n − p 4

Executive functions and sense of smell: a study in patients with Parkinson's disease

openLa Malattia di Parkinson (MP) è una patologia neurodegenerativa multisistemica con manifestazioni motorie (bradicinesia, rigidità, tremori) e non motorie (disturbi neuropsichiatrici, del sonno, della funzione gastrointestinale, della cognizione e dei sistemi sensoriali). Tale patologia è determinata dal deterioramento dei neuroni nigro-striatali deputati alla produzione di dopamina nel cervello, che porta ad una degenerazione a carico di strutture sottocorticali note come gangli della base. Esse, oltre ad essere deputate al controllo del tono muscolare e della corretta esecuzione dei movimenti, sono risultate implicate nella supervisione delle funzioni esecutive. La MP è caratterizzata dalla progressiva insorgenza di deficit a carico delle funzioni esecutive, specificamente nei domini di: attenzione divisa, set-shifting, problem solving, inibizione degli impulsi, Working-Memory (WM) e flessibilità cognitiva. Evidenze scientifiche riportano inoltre come prodromo di malattia la disfunzione olfattiva, una delle prime manifestazioni della MP, che compare molti anni prima dei segni motori. Inoltre, ricerche recenti, hanno osservato che le strutture sottocorticali sono coinvolte nel controllo degli impulsi, infatti nei pazienti affetti da malattia di Parkinson vi è spesso una parziale sovrapposizione tra disfunzione esecutiva e deficit nel controllo inibitorio delle risposte comportamentali. Gli obiettivi del mio lavoro di tesi sono tre: confermare la presenza di una correlazione lineare positiva tale per cui al peggiorare dell’olfatto si assiste ad una maggiore compromissione esecutiva in pazienti con diagnosi di MP; valutare la capacità olfattiva soggettiva, correlando tale indice con le prestazioni cognitive a carico delle funzioni esecutive nei pazienti con MP; ed infine indagare la presenza di una relazione tra disfunzione della capacità olfattiva e deficit del controllo inibitorio dei comportamenti (ICD) nei pazienti con MP.Parkinson's disease (PD) is a multisystem neurodegenerative disease with motor (bradykinesia, rigors, tremors) and non-motor (neuropsychiatric, sleep, gastrointestinal function, cognition, and sensory system disorders) manifestations. This pathology is determined by the deterioration of the nigro-striatal neurons responsible for the production of dopamine in the brain, which leads to a degeneration of subcortical structures known as basal ganglia. In addition to being responsible for controlling muscle tone and the correct execution of movements, they have been implicated in the supervision of executive functions. PD is characterized by the progressive onset of deficits in executive functions, specifically in the domains of: divided attention, set-shifting, problem solving, impulse inhibition, Working-Memory (WM) and cognitive flexibility. Scientific evidence also reports olfactory dysfunction as a prodrome of the disease, one of the first manifestations of PD, which appears many years before the motor signs. Furthermore, recent research has observed that subcortical structures are involved in impulse control, in fact in patients with Parkinson's disease there is often a partial overlap between executive dysfunction and deficits in the inhibitory control of behavioral responses. The objectives of my thesis work are three: to confirm the presence of a positive linear correlation such that as the sense of smell worsens, there is a greater executive impairment in patients diagnosed with PD; evaluate the subjective olfactory ability, correlating this index with the cognitive performance of executive functions in patients with PD; and finally to investigate the presence of a relationship between dysfunction of the olfactory capacity and deficit of the inhibitory control of behaviors (ICD) in patients with PD

Utilizando a lingua inglesa para mostrar os benefícios de uma alimentação saudável as crianças e adolescentes

Orientadora: Elizabeth BernardinoMonografia (Especialização) - Universidade Aberta do Brasil Universidade Federal do Paraná. Coordenação de Integração de Politica de Educação a Distancia.Setor de Ciências da Saúde.Departamento de Enfermagem. Curso de Especialização em Saúde para Professores do Ensino Fundamental e Médi

La caixa de núvia. Un procés del segle XIV

A fourteenth century caixa de nuvia (a bride’s case). This article studies a bride’s case, or chest described in the records of a trial that took place in the late fourteenth century, preserved in the Archives of Crown of Aragon. The case was claimed by Eulàlia, a commoner from the region of Barcelona. We study the circumstances of the claim, and then consider the descriptions of the items and the relations between the items and the owner. We stress the structures and the functionality of the chest itself and the meticulous description of contents , mainly second hand household wear and engagement presents. We highlight the relationship between women, especially between the mother and the daughter, and the relationship between these women and their possessions

Electrodeposición de recubrimientos de fosfato de calcio sobre titanio

El titanio y sus aleaciones son biomateriales usados frecuentemente en implantes y prótesis. Sin embargo, estos biomateriales metálicos tienen limitaciones relacionadas con la bioactividad.Una vía para aumentar la bioactividad del titanio es añadir un recubrimiento de fosfato de calcio (CaP) a la superficie mediante deposición electroquímica. Esta técnica tiene como ventajas la baja temperatura del proceso y un buen control del espesor y la composición química de la capa depositada. Durante el proceso, sin embargo, se producen burbujas de hidrógeno en las proximidades del cátodo, que dificultan la obtención de capas uniformes.El presente estudio propone usar corriente pulsada para la electrodeposición como mecanismo para reducir la producción de burbujas de hidrógeno y mejorar el equilibrio de la concentración de iones en la solución, permitiendo la formación de capas de fosfato de calcio más uniformes.Peer Reviewe

Consumos culturales juveniles y prácticas educativas: los consumos musicales

Entre los diferentes consumos culturales, la música es una importante mediación en la conformación de las subjetividades juveniles. En particular, la adhesión a determinados ritmos y performances, como los del rock nacional y la cumbia, permite delinear identidades anheladas e imaginar instituciones alternativas o mundos utópicos. La música es el bien cultural que más alimenta las narrativas adolescentes, a partir de las cuales inician la comprensión del mundo que los rodea. El rock nacional ha proporcionado desde sus inicios en la Argentina un espacio de resistencia a los poderes hegemónicos y de conservación de un pensamiento nacional y popular, de larga tradición. La cumbia, en sus variantes romántica y villera, proporciona tanto espacios subjetivos de introspección y catarsis -vitales en períodos de crisis económico-sociales- como la posibilidad de reivindicar ciertas construcciones de la masculinidad y la femineidad estigmatizadas por otros sectores sociales. Las cuestiones abordadas no son para ser estudiadas en el aula ni para transformarlas en contenido curricular. Se pretende contribuir a la reconstrucción de un puente –quebrado por la violencia y el saqueo a cargo de los poderes dominantes– entre el mundo de nuestros alumnos como sujetos (no como objetos de aprendizaje simplemente) y los docentes, adultos capaces de interpretar ese mundo y ofrecer a la vez un espacio de protección para que ese mundo pueda ser comunicado

Efficacy and Safety of Oral Fosfomycin for Asymptomatic Bacteriuria in Kidney Transplant Recipients: Results from a Spanish Multicenter Cohort

Current guidelines recommend against systematic screening for or treating asymptomatic bacteriuria (AB) among kidney transplant (KT) recipients, although the evidence regarding episodes occurring early after transplantation or in the presence of anatomical abnormalities is inconclusive. Oral fosfomycin may constitute a good option for the treatment of posttransplant AB, particularly due to the emergence of multidrug-resistant (MDR) uropathogens. Available clinical evidence supporting its use in this specific setting, however, remains scarce. We performed a retrospective study in 14 Spanish institutions from January 2005 to December 2017. Overall, 137 episodes of AB diagnosed in 133 KT recipients treated with oral fosfomycin (calcium and trometamol salts) with a test-of-cure urine culture within the first 30 days were included. Median time from transplantation to diagnosis was 3.1 months (interquartile range [IQR], 1.1 to 10.5). Most episodes (96.4% [132/137]) were caused by Gram-negative bacteria (GNB), and 56.9% (78/137) were categorized as MDR (extended‐spectrum β‐lactamase‐producing Enterobacterales [20.4%] and carbapenem‐resistant GNB [2.9%]). Rate of microbiological failure at month 1 was 40.1% (95% confidence interval [CI], 31.9% to 48.9%) for the whole cohort and 42.3% (95% CI, 31.2% to 54.0%) for episodes due to MDR pathogens. Previous urinary tract infection (odds ratio [OR], 2.42; 95% CI, 1.11 to 5.29; P value = 0.027) and use of fosfomycin as salvage therapy (OR, 8.31; 95% CI, 1.67 to 41.35; P value = 0.010) were predictors of microbiological failure. No severe treatment-related adverse events were detected. Oral fosfomycin appears to be a suitable and safe alternative for the treatment (if indicated) of AB after KT, including those episodes due to MDR uropathogens