Ocean data manager: practical software for oceanographic sensors

Peer Reviewe

Assessment of the antioxidant properties of tomato extracts: A synergistic approach using in vitro chemical tests and cell-based assays

The aim of this research was to assess the total antioxidant activity (TAA) of lipophilic (Lextr) and hydrophilic (Hextr) tomato extracts using in vitro chemical tests and cell-based assays, focusing on possible synergistic actions between tomato antioxidants. Both Hextr and Lextr were HPLC analysed for their carotenoids, phenolic compounds, and ascorbic acid contents. For the evaluation of TAA, extracts were assayed alone or in combination using in vitro chemical tests (TEAC, FRAP) and cell-based (CAA) assays using human hepatoma (HepG2) and human histiocytic lymphoma (U937) cells. The only carotenoid detected in Lextr was lycopene, while a mixture of phenolic compounds (chlorogenic acid, caffeic acid, and rutin) was identified in Hextr. Ascorbic acid was not found either in Hextr or in Lextr. Upon extract combination (1:1, v/v), the FRAP assay revealed additive action between Lextr and Hextr, whilst a slight synergistic action was observed in TAA as measured by the TEAC assay. Synergistic action was better revealed when TAA was analysed using either U937 or HepG2 cells. This could be explained by the presence of a multiphase media (cell membrane and extra- and intracellular media) that might facilitate the distribution and interaction of antioxidants with different polarities and different mechanisms of action

Osteosarcoma telangiectásico: a propósito de un caso localizado en tibia distal

El osteosarcoma telangiectásico es una rara variedad de osteosarcoma. La característica principal que lo diferencia del osteosarcoma convencional es la anatomía patológica, ya que está formado por áreas quísticas ocupadas por material hemático, siendo la producción de osteoide por las células malignas muy escasa. El pronóstico de este tumor ha variado radicalmente desde la introducción de la quimioterapia a la que responde incluso mejor que el osteosarcoma convencional. Presentamos un caso de osteosarcoma telangiectásico en un niño de 8 años a nivel de la tibia distal, revisando la literatura sobre este tema.The telangiectatic osteosarcoma is a rare variety of osteogenic sarcoma. The main characteristic that make it different is the histology, because is formed by cistic spaces that contain blood. The osteoid production used to be limited. The prognosis of this tumor has change since the introduction of adjuvant chemotherapy. This type of tumor respond to chemotherapy even better than the primary osteogenic sarcoma. We present a case of telangiectatic osteosarcoma in a 8-year-old located in the distal tibia and we review the literature about this item

A basic probability assignment methodology for unsupervised wireless intrusion detection

YesThe broadcast nature of wireless local area networks has made them prone to several types of wireless injection attacks, such as Man-in-the-Middle (MitM) at the physical layer, deauthentication, and rogue access point attacks. The implementation of novel intrusion detection systems (IDSs) is fundamental to provide stronger protection against these wireless injection attacks. Since most attacks manifest themselves through different metrics, current IDSs should leverage a cross-layer approach to help toward improving the detection accuracy. The data fusion technique based on the Dempster–Shafer (D-S) theory has been proven to be an efficient technique to implement the cross-layer metric approach. However, the dynamic generation of the basic probability assignment (BPA) values used by D-S is still an open research problem. In this paper, we propose a novel unsupervised methodology to dynamically generate the BPA values, based on both the Gaussian and exponential probability density functions, the categorical probability mass function, and the local reachability density. Then, D-S is used to fuse the BPA values to classify whether the Wi-Fi frame is normal (i.e., non-malicious) or malicious. The proposed methodology provides 100% true positive rate (TPR) and 4.23% false positive rate (FPR) for the MitM attack and 100% TPR and 2.44% FPR for the deauthentication attack, which confirm the efficiency of the dynamic BPA generation methodology.Gulf Science, Innovation and Knowledge Economy Programme of the U.K. Government under UK-Gulf Institutional Link Grant IL 279339985 and in part by the Engineering and Physical Sciences Research Council (EPSRC), U.K., under Grant EP/R006385/1

Fretting fatigue life prediction using the extended finite element method

In this work, fretting fatigue tests available in the literature are modeled using the extended finite element method (XFEM). The aim is to numerically evaluate the stress intensity factors (SIFs) for cracks of different lengths emanating at the end of the contact zone and to estimate the propagation life corresponding to each of the tests. This propagation life is combined with the initiation life calculated analytically using a multiaxial fatigue criterion (Fatemi-Socie), following a initiation-propagation approach for life estimation. The predicted lives are then compared with the reported experimental lives. It is shown that the consideration of the crack-contact interaction through the numerical models tends to improve the life estimation when compared with a fully analytical approach for the calculation of both initiation and propagation lives.Ministerio de Ciencia y Tecnología DPI2007-66995-C0301Ministerio de Ciencia y Tecnología DPI2007-66995-C03-02

Global Distribution of Key Features of Streamer Corona Discharges in Thunderclouds

We present nighttime worldwide distributions of key features of Blue LUminous Events (BLUEs) detected by the Modular Multispectral Imaging Array of the Atmosphere-Space Interaction Monitor. Around 10% of all detected BLUEs exhibit an impulsive single pulse shape. The rest of BLUEs are unclear (impulsive or not) single, multiple or with ambiguous pulse shapes. BLUEs exhibit two distinct populations with peak power density <25 µWm−2 (common) and ≥25 µWm−2 (rare) with different rise times and durations. The altitude (and depth below cloud tops) zonal distribution of impulsive single pulse BLUEs indicate that they are commonly present between cloud tops and a depth of ≤4 km in the tropics and ≤1 km in mid and higher latitudes. Impulsive single pulse BLUEs in the tropics are the longest (up to ∼4 km height) and have the largest number of streamers (up to ∼3 × 109). Additionally, the analysis of BLUEs has turned out to be particularly complex due to the abundance of radiation belt particles (at high latitudes and in the South Atlantic Anomaly [SAA]) and cosmic rays all over the planet. True BLUEs can not be fully distinguished from radiation belt particles and cosmic rays unless other ground-based measurements associated with the optically detected BLUEs are available. Thus, the search algorithm of BLUEs presented in Soler et al. (2021), https://doi.org/10.1029/2021gl094657 is now completed with a new additional step that, if used, can considerably smooth the SAA shadow but can also underestimate the number of BLUEs worldwide.publishedVersio

Hidden Markov models and alert correlations for the prediction of advanced persistent threats

YesCyber security has become a matter of a global interest, and several attacks target industrial companies and governmental organizations. The advanced persistent threats (APTs) have emerged as a new and complex version of multi-stage attacks (MSAs), targeting selected companies and organizations. Current APT detection systems focus on raising the detection alerts rather than predicting APTs. Forecasting the APT stages not only reveals the APT life cycle in its early stages but also helps to understand the attacker's strategies and aims. This paper proposes a novel intrusion detection system for APT detection and prediction. This system undergoes two main phases; the first one achieves the attack scenario reconstruction. This phase has a correlation framework to link the elementary alerts that belong to the same APT campaign. The correlation is based on matching the attributes of the elementary alerts that are generated over a configurable time window. The second phase of the proposed system is the attack decoding. This phase utilizes the hidden Markov model (HMM) to determine the most likely sequence of APT stages for a given sequence of correlated alerts. Moreover, a prediction algorithm is developed to predict the next step of the APT campaign after computing the probability of each APT stage to be the next step of the attacker. The proposed approach estimates the sequence of APT stages with a prediction accuracy of at least 91.80%. In addition, it predicts the next step of the APT campaign with an accuracy of 66.50%, 92.70%, and 100% based on two, three, and four correlated alerts, respectively.The Gulf Science, Innovation and Knowledge Economy Programme of the U.K. Government under UK-Gulf Institutional Link Grant IL 279339985 and in part by the Engineering and Physical Sciences Research Council (EPSRC), U.K., under Grant EP/R006385/1

ESTUDIO DEL PERFORMANCE DE LOS GRUPOS ESTRATÉGICOS EN EL SISTEMA DE FRANQUICIA ESPAÑOL

La preocupación por considerar la heterogeneidad en los comportamientos empresariales dentro de un sector de actividad, ha sido uno de los principales motivos para la búsqueda e identificación de grupos estratégicos, generando un debate inagotable en el ámbito de la estrategia empresarial. Sin embargo, esta preocupación no se ha limitado a identificar arquetipos o configuraciones empresariales, sino que también se ha extendido al estudio de posibles diferencias en el rendimiento entre los grupos identificados. En el presente trabajo, intentamos dar respuesta a esta doble preocupación y todo ello centrándonos en el ámbito de la franquicia. Para ello, se ha elaborado una base de datos con el total de cadenas franquiciadoras (664) que en el año 2005 operaban en España. Los resultados obtenidos revelan la existencia de cinco grupos estratégicos (tipos de franquiciadores) perfectamente diferenciados, los cuales son descritos a partir de las variables estratégicas que los definen. Igualmente, se demuestra la existencia de diferencias en los resultados inter-grupales a partir de determinados indicadores de desempeño (ingresos, resultados ordinarios y rentabilidad)