Improving time-randomized cache design

Enabling timing analysis for caches has been pursued by the critical real-time embedded systems (CRTES) community for years due to their potential to reduce worstcase execution times (WCET). Measurement-based protabilistic timing analysis (MBPTA) techniques have emerged as a solution to time-analyze complex hardware including caches, as long as they implement some random policies. Existing random placement and replacement policies have been proven efficient to some extent for single-level caches. However, they may lead to some probabilistic pathological eviction scenarios. In this work we propose new random placement and replacement policies specifically tailored for multi-level caches and for avoiding any type of pathological case

PKIX Certificate Status in Hybrid MANETs

Certificate status validation is a hard problem in general but it is particularly complex in Mobile Ad-hoc Networks (MANETs) because we require solutions to manage both the lack of fixed infrastructure inside the MANET and the possible absence of onnectivity to trusted authorities when the certification validation has to be performed. In this sense, certificate acquisition is usually assumed as an initialization phase. However, certificate validation is a critical operation since the node needs to check the validity of certificates in real-time, that is, when a particular certificate is going to be used. In such MANET environments, it may happen that the node is placed in a part of the network that is disconnected from the source of status data at the moment the status checking is required. Proposals in the literature suggest the use of caching mechanisms so that the node itself or a neighbour node has some status checking material (typically on-line status responses or lists of revoked certificates). Howeve to the best of our knowledge the only criterion to evaluate the cached (obsolete) material is the time. In this paper, we analyse how to deploy a certificate status checking PKI service for hybrid MANET and we propose a new criterion based on risk to evaluate cached status data that is much more appropriate and absolute than time because it takes into account the revocation process.Peer ReviewedPostprint (author’s final draft

Low-Dose PET/CT and Full-Dose Contrast-Enhanced CT at the Initial Staging of Localized Diffuse Large B-Cell Lymphomas

Computed tomography (CT) has been used as the reference imaging technique for the initial staging of diffuse large B-cell lymphoma until recent days, when the introduction of positron emission tomography (PET)/CT imaging as a hybrid technique has become of routine use. However, the performance of both examinations is still common. The aim of this work was to compare the findings between low-dose 2-deoxy-2-(F-18) fluoro-D-glucose (F-18-FDG) PET/CT and full-dose contrast-enhanced CT (ceCT) in 28 patients with localized diffuse large B-cell lymphoma according to PET/CT findings, in order to avoid the performance of ceCT. For each technique, a comparison in the number of nodal and extranodal involved regions was performed. PET/CT showed more lesions than ceCT in both nodal (41 vs. 36) and extranodal localizations (16 vs. 15). Disease staging according to both techniques was concordant in 22 patients (79%) and discordant in 6 patients (21%), changing treatment management in 3 patients (11%). PET/CT determined a better staging and therapeutic approach, making the performance of an additional ceCT unnecessary

Effect of osteoprotegerin and Dickkopf-related protein 1 on radiological progression in tightly controlled rheumatoid arthritis.

OBJECTIVE: To analyze the association between circulating osteoprotegerin (OPG) and Dickkopf-related protein 1 (DKK-1) and radiological progression in patients with tightly controlled rheumatoid arthritis (RA). METHODS: Serum levels of OPG and DKK-1 were measured in 97 RA patients who were treated according to a treat-to-target strategy (T2T) aimed at remission (DAS28<2.6). Radiologic joint damage progression was assessed by changes in the total Sharp-van der Heijde score (SHS) on serial radiographs of the hands and feet. The independent association between these biomarker levels and the structural damage endpoint was examined using regression analysis. RESULTS: The mean age of the 97 RA patients (68 women) at the time of the study was 54 ± 14 years, and the median disease duration was 1.6 ± 1.5 years. Most patients were seropositive for either RF or ACPA, and the large majority (76%) were in remission or had low disease activity. After a median follow-up time of 3.3 ± 1.5 years (range, 1-7.5 yrs.), the mean total SHS annual progression was 0.88 ± 2.20 units. Fifty-two percent of the patients had no progression (defined as a total SHS of zero). The mean serum OPG level did not change significantly over the study period (from 3.9 ± 1.8 to 4.07 ± 2.23 pmol/L), whereas the mean serum DKK-1 level decreased, although not significantly (from 29.9 ± 10.9 to 23.6 ± 18.8 pmol/L). In the multivariate analysis, the predictive factors increasing the likelihood of total SHS progression were age (OR per year = 1.10; p = 0.003) and a high mean C-reactive protein level over the study period (OR = 1.29; p = 0.005). Circulating OPG showed a protective effect reducing the likelihood of joint space narrowing by 60% (95% CI: 0.38-0.94) and the total SHS progression by 48% (95% CI: 0.28-0.83). The DKK-1 levels were not associated with radiological progression. CONCLUSION: In patients with tightly controlled RA, serum OPG was inversely associated with progression of joint destruction. This biomarker may be useful in combination with other risk factors to improve prediction in patients in clinical remission or low disease activity state

Imaging of skull vault tumors in adults

The skull vault, formed by the flat bones of the skull, has a limited spectrum of disease that lies between the fields of neuro- and musculoskeletal radiology. Its unique abnormalities, as well as other ubiquitous ones, present particular features in this location. Moreover, some benign entities in this region may mimic malignancy if analyzed using classical bone-tumor criteria, and proper patient management requires being familiar with these presentations. This article is structured as a practical review offering a systematic diagnostic approach to focal calvarial lesions, broadly organized into four categories: (1) pseudolesions: arachnoid granulations, meningo-/encephaloceles, vascular canals, frontal hyperostosis, parietal thinning, parietal foramina, and sinus pericrani; (2) lytic: fibrous dysplasia, epidermal inclusion and dermoid cysts, eosinophilic granuloma, hemangioma, aneurysmal bone cyst, giant cell tumor, metastasis, and myeloma; (3) sclerotic: osteomas, osteosarcoma, and metastasis; (4) transdiploic: meningioma, hemangiopericytoma, lymphoma, and metastasis, along with other less common entities. Tips on the potential usefulness of functional imaging techniques such as MR dynamic susceptibility (T2*) perfusion, MR spectroscopy, diffusion-weighted imaging, and PET imaging are provided

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Universidad y sociedad: comunicación e integración en empresas e instituciones públicas y organizaciones no lucrativas: innovación y progreso

Depto. de Teorías y Análisis de la ComunicaciónFac. de Ciencias de la InformaciónFALSEsubmitte

Mecanismo para evitar ataques por confabulación basados en code passing

Los agentes móviles son entidades software formadas por código, datos, itinerario y estado, que pueden migrar de host en host autónomamente ejecutando su código. A pesar de sus ventajas, los aspectos de seguridad restringen enormemente el uso de código móvil. La protección del agente ante ataques de hosts maliciosos, es el problema de seguridad más difícil de resolver en los sistemas de agentes móviles. En particular, los ataques por confabulación han sido poco estudiados en la literatura. Este paper presenta un mecanismo de protección ante ataques por confabulación basados en code passing. Nuestra propuesta es un Multi-Code Agent que contiene diferentes variantes del código para cada host. Una Trusted Third Party es la responsable de proporcionar la información para extraer cada variante, y de tomar referencias temporales que se usarán para verificar la coherencia temporal.Peer ReviewedPostprint (published version

Mecanismo para evitar ataques por confabulación basados en code passing

Los agentes móviles son entidades software formadas por código, datos, itinerario y estado, que pueden migrar de host en host autónomamente ejecutando su código. A pesar de sus ventajas, los aspectos de seguridad restringen enormemente el uso de código móvil. La protección del agente ante ataques de hosts maliciosos, es el problema de seguridad más difícil de resolver en los sistemas de agentes móviles. En particular, los ataques por confabulación han sido poco estudiados en la literatura. Este paper presenta un mecanismo de protección ante ataques por confabulación basados en code passing. Nuestra propuesta es un Multi-Code Agent que contiene diferentes variantes del código para cada host. Una Trusted Third Party es la responsable de proporcionar la información para extraer cada variante, y de tomar referencias temporales que se usarán para verificar la coherencia temporal.Peer Reviewe

Mecanismo para evitar ataques por confabulación basados en code passing

Los agentes móviles son entidades software formadas por código, datos, itinerario y estado, que pueden migrar de host en host autónomamente ejecutando su código. A pesar de sus ventajas, los aspectos de seguridad restringen enormemente el uso de código móvil. La protección del agente ante ataques de hosts maliciosos, es el problema de seguridad más difícil de resolver en los sistemas de agentes móviles. En particular, los ataques por confabulación han sido poco estudiados en la literatura. Este paper presenta un mecanismo de protección ante ataques por confabulación basados en code passing. Nuestra propuesta es un Multi-Code Agent que contiene diferentes variantes del código para cada host. Una Trusted Third Party es la responsable de proporcionar la información para extraer cada variante, y de tomar referencias temporales que se usarán para verificar la coherencia temporal.Peer Reviewe