245 research outputs found
Crecimiento y contenido de larvas de atún rojo (Thunnus thynnus) y atún blanco (Thunnus alalunga)
The waters surrounding the Balearic archipelago are considered to be prime spawning habitats of the bluefin tuna (Thunnus thynnus) and other tuna species such as albacore (T. alalunga) in the Mediterranean. During the 2003 bluefin and albacore spawning season, a tuna larval survey (TUNIBAL 0703) was carried out to assess the distribution of bluefin larvae in relation to hydrographic mesoscale features. Tuna larvae were collected by means of surface plankton tows with a bongo gear with a quadrangular mouth measuring 1 m diagonally. The otolith microstructure of 157 and 71 field-captured larvae of Mediterranean bluefin and albacore, respectively, were analyzed to estimate the daily growth pattern. Furthermore, biochemical analysis to estimate DNA, RNA and protein content was done on another batch of 114 bluefin and 132 albacore larvae. The size range included pre-flexion to post-flexion larvae, from 2.8 to 8.6 mm in body length. bluefin and albacore larvae grew linearly in standard length (0.35 and 0.33 mm/day, respectively) and potentially with respect to dry weight. No significant differences between species were observed in the size-weight relationship, or in the allometric relationship of body size and weight to otolith radius. However, the relationship of DNA and RNA to body size and weight showed a significant difference between species. Bluefin tuna larvae showed a greater nucleic acid content than albacore larvae. Protein content showed no significant differences with respect to body length.Las aguas de las Islas Baleares representan una de las zonas más importantes de puesta del atún rojo (Thunnus thynnus) y de otras especies asociadas, como el atún blanco albacore (T. alalunga). En julio del 2003, época de puesta del atún, se realizó la campaña TUNIBAL, con el fin de delimitar las zonas de puesta del atún rojo, así como su relación con el modelo de circulación en el área. Las larvas de atunes se muestrearon mediante arrastres superficiales con una red Bongo de boca cuadrangular (1 m en diagonal). Para el estudio del crecimiento diario, 157 larvas de atún rojo y 71 larvas de atún blanco fueron analizadas. Para el estudio de la condición larvaria (DNA, RNA y proteínas), 119 larvas de atún rojo y 138 larvas de atún blanco fueron analizadas. Se analizaron larvas desde estados de pre-flexión a post-flexión, desde 2.8 a 8.6 mm de longitud estándar. Las larvas de atún rojo y atún blanco crecen linealmente en longitud estándar (0.35 y 0.33 mm/día respectivamente) y potencialmente en peso seco. No se encontraron diferencias significativas en la relación talla-peso, o en la relación del radio del otolito con talla o peso. Sin embargo, la relación entre DNA y RNA con talla o peso mostró diferencias significativas entre especies, siendo el atún rojo el que mostró mayores contenidos en ácidos nucleicos. No obstante, el contenido en proteínas no mostró diferencias significativas con la talla entre especies
Anomaly-based network intrusion detection: Techniques, systems and challenges.
Threat Intrusion detection Anomaly detection IDS systems and platforms Assessment a b s t r a c t The Internet and computer networks are exposed to an increasing number of security threats. With new types of attacks appearing continually, developing flexible and adaptive security oriented approaches is a severe challenge. In this context, anomaly-based network intrusion detection techniques are a valuable technology to protect target systems and networks against malicious activities. However, despite the variety of such methods described in the literature in recent years, security tools incorporating anomaly detection functionalities are just starting to appear, and several important problems remain to be solved. This paper begins with a review of the most well-known anomaly-based intrusion detection techniques. Then, available platforms, systems under development and research projects in the area are presented. Finally, we outline the main challenges to be dealt with for the wide scale deployment of anomaly-based intrusion detectors, with special emphasis on assessment issues. ª 2008 Elsevier Ltd. All rights reserved. Introduction Intrusion Detection Systems (IDS) are security tools that, like other measures such as antivirus software, firewalls and access control schemes, are intended to strengthen the security of information and communication systems. Although, as shown i
Integrated Clustering and Anomaly Detection (INCAD) for Streaming Data (Revised)
Most current clustering based anomaly detection methods use scoring schema
and thresholds to classify anomalies. These methods are often tailored to
target specific data sets with "known" number of clusters. The paper provides a
streaming clustering and anomaly detection algorithm that does not require
strict arbitrary thresholds on the anomaly scores or knowledge of the number of
clusters while performing probabilistic anomaly detection and clustering
simultaneously. This ensures that the cluster formation is not impacted by the
presence of anomalous data, thereby leading to more reliable definition of
"normal vs abnormal" behavior. The motivations behind developing the INCAD
model and the path that leads to the streaming model is discussed.Comment: 13 pages; fixes typos in equations 5,6,9,10 on inference using Gibbs
samplin
BOOTES-IR: Near IR follow-up GRB observations by a robotic system
“BOOTES-IR” is the extension of the BOOTES experiment, which
operates in Southern Spain since 1998, to the near IR (NIR). The goal is to follow up the early stage of the gamma ray burst (GRB) afterglow emission in the NIR, alike BOOTES does already at optical wavelengths. The scientific case that drives the BOOTES-IR performance is the study of GRBs with the support of spacecraft like INTEGRAL, SWIFT and GLAST. Given that the afterglow emission in both, the NIR and the optical, in the instances immediately following a GRB, is extremely bright (reached V = 8.9 in one case), it should be possible to detect this prompt emission at NIR wavelengths too. The combined observations by BOOTES-IR and
BOOTES-1 and BOOTES-2 will allow for real time identification of trustworthy candidates to have a high redshift (z > 5). It is expected that, few minutes after
a GRB, the IR magnitudes be H ∼ 7–10, hence very high quality spectra can be obtained for objects as far as z = 10 by larger instruments
R-Locker: Thwarting Ransomware Action through a Honey le-based Approach
Ransomware has become a pandemic nowadays. Although some proposals
exist to fight against this increasing type of extorsion, most of them are prevention like and rely on the assumption that early detection is not so effective
once the victim is infected. This paper presents a novel approach intended
not just to early detect ransomware but to completly thwart its action. For
that, a set of honeyfiles are deployed around the target environment in order
to catch the ransomware. Instead of being normal archives, honeyfiles are
FIFO like, so that the ransomware is blocked once it starts reading the file.
In addition to frustrate its action, our honeyfile solution is able to automatically launch countermeasures to solve the infection. Moreover, as it does not
require previous training or knowledge, the approach allows fighting against
unknown, zero-day ransomware related attacks. As a proof of concept, we
have developed the approach for Unix platforms. The tool, named R-Locker,
shows excellent performance both from the perspective of its accuracy as well
as in terms of complexity and resource consumption. In addition, it has no
special needs or privileges and does not affect the normal operation of the
overall environment
<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7.
Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release.
Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue.
Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7.
Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data
Bortezomib plus melphalan and prednisone in elderly untreated patients with multiple myeloma: updated time-to-events results and prognostic factors for time to progression
New treatment options offering enhanced activity in elderly, newly diagnosed patients with multiple
myeloma are required. One strategy is to combine melphalan and prednisone with novel agents.
We previously reported an 89% response rate, including 32% complete responses and 11% near
complete responses, in our phase 1/2 study of bortezomib plus melphalan and prednisone (VMP)
in 60 newly diagnosed multiple myeloma patients with a median age of 75 years. Here, we report
updated time-to-events data and the impact of poor prognosis factors on outcome
Molecular analysis of Mycobacterium isolates from extrapulmonary specimens obtained from patients in Mexico
<p>Abstract</p> <p>Background</p> <p>Little information is available on the molecular epidemiology in Mexico of <it>Mycobacterium </it>species infecting extrapulmonary sites in humans. This study used molecular methods to determine the <it>Mycobacterium </it>species present in tissues and body fluids in specimens obtained from patients in Mexico with extrapulmonary disease.</p> <p>Methods</p> <p>Bacterial or tissue specimens from patients with clinical or histological diagnosis of extrapulmonary tuberculosis were studied. DNA extracts from 30 bacterial cultures grown in Löwenstein Jensen medium and 42 paraffin-embedded tissues were prepared. Bacteria were cultured from urine, cerebrospinal fluid, pericardial fluid, gastric aspirate, or synovial fluid samples. Tissues samples were from lymph nodes, skin, brain, vagina, and peritoneum. The DNA extracts were analyzed by PCR and by line probe assay (INNO-LiPA MYCOBACTERIA v2. Innogenetics NV, Gent, Belgium) in order to identify the <it>Mycobacterium </it>species present. DNA samples positive for <it>M. tuberculosis </it>complex were further analyzed by PCR and line probe assay (INNO-LiPA Rif.TB, Innogenetics NV, Gent, Belgium) to detect mutations in the <it>rpo</it>B gene associated with rifampicin resistance.</p> <p>Results</p> <p>Of the 72 DNA extracts, 26 (36.1%) and 23 (31.9%) tested positive for <it>Mycobacterium species </it>by PCR or line probe assay, respectively. In tissues, <it>M. tuberculosis </it>complex and <it>M. genus </it>were found in lymph nodes, and <it>M. genus </it>was found in brain and vagina specimens. In body fluids, <it>M. tuberculosis </it>complex was found in synovial fluid. <it>M. gordonae</it>, <it>M. smegmatis</it>, <it>M. kansasii</it>, <it>M. genus</it>, <it>M. fortuitum/M. peregrinum </it>complex and <it>M. tuberculosis </it>complex were found in urine. <it>M. chelonae/M. abscessus </it>was found in pericardial fluid and <it>M. kansasii </it>was found in gastric aspirate. Two of <it>M. tuberculosis </it>complex isolates were also PCR and LiPA positive for the <it>rpo</it>B gene. These two isolates were from lymph nodes and were sensitive to rifampicin.</p> <p>Conclusion</p> <p>1) We describe the <it>Mycobacterium </it>species diversity in specimens derived from extrapulmonary sites in symptomatic patients in Mexico; 2) Nontuberculous mycobacteria were found in a considerable number of patients; 3) Genotypic rifampicin resistance in <it>M. tuberculosis </it>complex infections in lymph nodes was not found.</p
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