2,375 research outputs found

    Stealthy Deception Attacks Against SCADA Systems

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    SCADA protocols for Industrial Control Systems (ICS) are vulnerable to network attacks such as session hijacking. Hence, research focuses on network anomaly detection based on meta--data (message sizes, timing, command sequence), or on the state values of the physical process. In this work we present a class of semantic network-based attacks against SCADA systems that are undetectable by the above mentioned anomaly detection. After hijacking the communication channels between the Human Machine Interface (HMI) and Programmable Logic Controllers (PLCs), our attacks cause the HMI to present a fake view of the industrial process, deceiving the human operator into taking manual actions. Our most advanced attack also manipulates the messages generated by the operator's actions, reversing their semantic meaning while causing the HMI to present a view that is consistent with the attempted human actions. The attacks are totaly stealthy because the message sizes and timing, the command sequences, and the data values of the ICS's state all remain legitimate. We implemented and tested several attack scenarios in the test lab of our local electric company, against a real HMI and real PLCs, separated by a commercial-grade firewall. We developed a real-time security assessment tool, that can simultaneously manipulate the communication to multiple PLCs and cause the HMI to display a coherent system--wide fake view. Our tool is configured with message-manipulating rules written in an ICS Attack Markup Language (IAML) we designed, which may be of independent interest. Our semantic attacks all successfully fooled the operator and brought the system to states of blackout and possible equipment damage

    Primer informe de Aelurostrongylus abstrusus en el caracol de tierra Rumina decollata, en la Ciudad Autónoma de Buenos Aires

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    Aelurostrongylus abstrusus (Railliet, 1898) is a worldwide distributed lungworm that affects wild and domestic cats, causing bronchopneumonia of varying intensity. Cats became infected by eating slugs and snails with third infective stage larvae (L3). The aim of the study was to describe the presence of A. abstrusus in R. decollate snails. R. decollata specimens and samples of cats’ faeces were collected from the open spaces of a public institution of Buenos Aires city, inhabited by a stray cat population. Cats’ faeces were processed by Baermman´s technique and snails were digested in pool, by artificial digestion method. First stage larvae of A. abstrusus were recovered from 35.30 % (6/17) of the sampled faeces. An 80 % (20/25) snails pools were positive for the second and third larval stages. Mean value of total larvae recovered per pool was 150.64 and mean value of L3/pool was 93.89. This is the first report of the development of A. abstrusus infective larvae in R. decollate snail as intermediate host, since the relationship between high levels of infection in snails and in cats’ faeces could be demonstrated in cats’ habitat.Aelurostrongylus abstrusus (Railliet, 1898) es un helminto pulmonar mundialmente distribuido que afecta a los gatos, causando bronconeumonias de variada intensidad. La infección se produce por ingestión de babosas y caracoles terrestres con larvas infectantes (L3). El objetivo del estudio fue describir la presencia de A. abstrusus en el caracol R. decollata. Se recolectaron muestras de heces felinas y caracoles presentes en una institución pública de la Ciudad Autónoma de Buenos Aires, habitada por una población de gatos sin propietario. Las heces fueron procesadas mediante la técnica de Baermman y los caracoles fueron digeridos en pool por digestión artificial enzimática. Larvas de primer estadio (L1) de A. abstrusus fueron recuperadas en el 35,30% (6/17) de las heces. El 80% (20/25) de los pooles de caracoles presentó larvas de segundo y tercer estadio. El promedio de larvas totales recuperado por pool fue de 150,64 y el valor medio de L3/pool fue de 93.89. Este es el primer hallazgo del desarrollo de larvas infectivas de A. abstrusus en el caracol doméstico R. decollata. Los altos niveles de infección encontrados en los caracoles y en las heces de los gatos demuestran el potencial de R. decollata como hospedador intermediario de A. abstrusus.Fil: Cardillo, Natalia Marina. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Area de Parasitología y Enfermedades Parasitarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Clemente, A.. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Area de Parasitología y Enfermedades Parasitarias; ArgentinaFil: Pasqualetti, M.. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Area de Parasitología y Enfermedades Parasitarias; ArgentinaFil: Borrás, P.. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Area de Parasitología y Enfermedades Parasitarias; ArgentinaFil: Rosa, A.. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Area de Parasitología y Enfermedades Parasitarias; ArgentinaFil: Ribicich, M.. Universidad de Buenos Aires. Facultad de Cs.veterinarias. Area de Parasitología y Enfermedades Parasitarias; Argentin

    The upstream Variable Number Tandem Repeat polymorphism of the monoamine oxidase type A gene influences trigeminal pain-related evoked responses

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    Monoamines have an important role in neural plasticity, a key factor in cortical pain processing that promotes changes in neuronal network connectivity. Monoamine oxidase type A (MAOA) is an enzyme that, due to its modulating role in monoaminergic activity, could play a role in cortical pain processing. The X-linked MAOA gene is characterized by an allelic variant of length, the MAOA upstream Variable Number Tandem Repeat (MAOA-uVNTR) region polymorphism. Two allelic variants of this gene are known, the high-activity MAOA (HAM) and low-activity MAOA (LAM). We investigated the role of MAOA-uVNTR in cortical pain processing in a group of healthy individuals measured by the trigeminal electric pain-related evoked potential (tPREP) elicited by repeated painful stimulation. A group of healthy volunteers was genotyped to detect MAOA-uVNTR polymorphism. Electrical tPREPs were recorded by stimulating the right supraorbital nerve with a concentric electrode. The N2 and P2 component amplitude and latency as well as the N2-P2 inter-peak amplitude were measured. The recording was divided into three blocks, each containing 10 consecutive stimuli and the N2-P2 amplitude was compared between blocks. Of the 67 volunteers, 37 were HAM and 30 were LAM. HAM subjects differed from LAM subjects in terms of amplitude of the grand-averaged and first-block N2-P2 responses (HAM>LAM). The N2-P2 amplitude decreased between the first and third block in HAM subjects but not LAM subjects. The MAOA-uVNTR polymorphism seemed to influence the brain response in a repeated tPREP paradigm and suggested a role of the MAOA as a modulator of neural plasticity related to cortical pain processing

    Sensitivity Studies for Third-Generation Gravitational Wave Observatories

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    Advanced gravitational wave detectors, currently under construction, are expected to directly observe gravitational wave signals of astrophysical origin. The Einstein Telescope, a third-generation gravitational wave detector, has been proposed in order to fully open up the emerging field of gravitational wave astronomy. In this article we describe sensitivity models for the Einstein Telescope and investigate potential limits imposed by fundamental noise sources. A special focus is set on evaluating the frequency band below 10Hz where a complex mixture of seismic, gravity gradient, suspension thermal and radiation pressure noise dominates. We develop the most accurate sensitivity model, referred to as ET-D, for a third-generation detector so far, including the most relevant fundamental noise contributions.Comment: 13 pages, 7 picture

    Reconstruction of the gravitational wave signal h(t)h(t) during the Virgo science runs and independent validation with a photon calibrator

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    The Virgo detector is a kilometer-scale interferometer for gravitational wave detection located near Pisa (Italy). About 13 months of data were accumulated during four science runs (VSR1, VSR2, VSR3 and VSR4) between May 2007 and September 2011, with increasing sensitivity. In this paper, the method used to reconstruct, in the range 10 Hz-10 kHz, the gravitational wave strain time series h(t)h(t) from the detector signals is described. The standard consistency checks of the reconstruction are discussed and used to estimate the systematic uncertainties of the h(t)h(t) signal as a function of frequency. Finally, an independent setup, the photon calibrator, is described and used to validate the reconstructed h(t)h(t) signal and the associated uncertainties. The uncertainties of the h(t)h(t) time series are estimated to be 8% in amplitude. The uncertainty of the phase of h(t)h(t) is 50 mrad at 10 Hz with a frequency dependence following a delay of 8 μ\mus at high frequency. A bias lower than 4μs4\,\mathrm{\mu s} and depending on the sky direction of the GW is also present.Comment: 35 pages, 16 figures. Accepted by CQ

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

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    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far

    Astrophysically Triggered Searches for Gravitational Waves: Status and Prospects

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    In gravitational-wave detection, special emphasis is put onto searches that focus on cosmic events detected by other types of astrophysical observatories. The astrophysical triggers, e.g. from gamma-ray and X-ray satellites, optical telescopes and neutrino observatories, provide a trigger time for analyzing gravitational wave data coincident with the event. In certain cases the expected frequency range, source energetics, directional and progenitor information is also available. Beyond allowing the recognition of gravitational waveforms with amplitudes closer to the noise floor of the detector, these triggered searches should also lead to rich science results even before the onset of Advanced LIGO. In this paper we provide a broad review of LIGO's astrophysically triggered searches and the sources they target

    Is psychiatric residential facility discharge possible and predictable? A multivariate analytical approach applied to a prospective study in Italy

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    A growing number of severely ill patients require long-term care in non-hospital residential facilities (RFs). Despite the magnitude of this development, longitudinal studies surveying fairly large resident samples and yielding important information on this population have been very few

    Sensitivity to Gravitational Waves from Compact Binary Coalescences Achieved during LIGO's Fifth and Virgo's First Science Run

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    We summarize the sensitivity achieved by the LIGO and Virgo gravitational wave detectors for compact binary coalescence (CBC) searches during LIGO's fifth science run and Virgo's first science run. We present noise spectral density curves for each of the four detectors that operated during these science runs which are representative of the typical performance achieved by the detectors for CBC searches. These spectra are intended for release to the public as a summary of detector performance for CBC searches during these science runs.Comment: 12 pages, 5 figure

    Search for gravitational waves associated with the InterPlanetary Network short gamma ray bursts

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    We outline the scientific motivation behind a search for gravitational waves associated with short gamma ray bursts detected by the InterPlanetary Network (IPN) during LIGO's fifth science run and Virgo's first science run. The IPN localisation of short gamma ray bursts is limited to extended error boxes of different shapes and sizes and a search on these error boxes poses a series of challenges for data analysis. We will discuss these challenges and outline the methods to optimise the search over these error boxes.Comment: Methods paper; Proceedings for Eduardo Amaldi 9 Conference on Gravitational Waves, July 2011, Cardiff, U
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