465 research outputs found
Status of the second phase of the MAGIC telescope
The MAGIC 17m diameter Cherenkov telescope will be upgraded with a second
telescope with advanced photon detectors and ultra fast readout within the year
2007. The sensitivity of MAGIC-II, the two telescope system, will be improved
by a factor of 2. In addition the energy threshold will be reduced and the
energy and angular resolution will be improved. The design, status and expected
performance of MAGIC-II is presented here.Comment: 4 pages, 5 figures, to appear in the proceedings of the 30th
International Cosmic Ray Conference, Merida, July 200
Break in the VHE spectrum of PG 1553+113: new upper limit on its redshift?
PG 1553+113 is a known BL Lac object, newly detected in the GeV-TeV energy
range by H.E.S.S and MAGIC. The redshift of this source is unknown and a lower
limit of was recently estimated. The very high energy (VHE) spectrum
of PG 1553+113 is attenuated due to the absorption by the low energy photon
field of the extragalactic background light (EBL). Here we correct the combined
H.E.S.S and MAGIC spectrum of PG 1553+113 for this absorption assuming a
minimum density of the evolving EBL. We use an argument that the intrinsic
photon index cannot be harder than and derive an upper limit on
the redshift of . Moreover, we find that a redshift above
implies a possible break of the intrinsic spectrum at about 200 GeV. Assuming
that such a break is absent, we derive a much stronger upper limit of . Alternatively, this break might be attributed to an additional emission
component in the jet of PG 1553+113. This would be the first evidence for a
second component is detected in the VHE spectrum of a blazar.Comment: revised version submitted to Ap
Upgrade of the MAGIC Telescope with a Multiplexed Fiber-Optic 2 GSamples/s FADC Data Acquisition system
In February 2007 the MAGIC Air Cherenkov Telescope for gamma ray astronomy
was fully upgraded with a fast 2 GSamples/s digitization system. The upgraded
readout system uses a novel fiber-optic multiplexing technique. It consists of
10-bit 2 GSamples/s FADCs to digitize 16 channels consecutively and optical
fibers to delay the analog signals. A distributed data acquisition system using
GBit Ethernet and FiberChannel technology allows to read out the 100 kByte
events with a continuous rate of up to 1 kHz.Comment: 4 pages, 6 figures, to appear in the proceedings of the 30th
International Cosmic Ray Conference, Merida, July 200
Attack Forecast and Prediction
Cyber-security has emerged as one of the most pressing issues for society with actors trying to use offensive capabilities and those who try to leverage on defensive capabilities to secure their assets or knowledge. However, in cyber-space attackers oftentimes have a significant first mover advantage leading to a dynamic cat and mouse game with defenders. Cyber Threat Intelligence (CTI) on past attacks bears potentials that can be used by means of predictive analytics to minimize the attackers first mover advantage. Yet, attack prediction is not an established means and automation levels are low. Within this work, we present Attack Forecast and Prediction ( ) which is based on MITRE Adversarial Tactics, Techniques and Common Knowledge (ATT&CK). consists of three modules representing different analytical procedures which are clustering, time series analysis, and genetic algorithms. identifies trends in the usage of attack techniques and crafts forecasts and predictions on future malware and the attack techniques used. We rely on time sorting to generate subgraphs of MITRE ATT&CK and evaluate the accuracy of predictions generated by based on these. Results of an experiment performed on the basis of 493 different malware, validate the utility of using for attack prediction. reaches for each module an F-score which is higher than an extrapolation of observed probabilities (baseline) with an F-score of up to 0.83 for a single module. It can hence be considered an effective means for predicting future attack patterns and help security professionals with preparing for future attacks
Monitoring of Bright Blazars with MAGIC in the 2007/2008 Season
Because of the short duty-cycles and observation-time constraints, studies of
bright TeV (E>100 GeV) blazars are mostly restricted to flaring episodes or
rather short (days to few weeks) multiwavelength campaigns. At the same time,
long-term studies of these objects are essential to gain a more complete
understanding of the blazar phenomenon and to constrain theoretical models
concerning jet physics. Only unbiased long-term studies are adequate for the
determination of flaring state probabilities and for estimating the statistical
significance of possible correlations between TeV flaring states and other
wavebands or observables, such as neutrino events. Regular observations also
provide triggers for multiwavelength ToO observations originating from the TeV
waveband. These are particularly needed to identify and study orphan TeV
flares, i.e. flares without counterparts in other wavebands. In 2007/8 the
MAGIC telescope has monitored three TeV blazars on a regular basis: Mrk 501,
Mrk 421, and 1ES 1959+650. We present preliminary results of these observations
including the measured light curves and a correlation study for VHE gamma-rays
and X-rays and VHE gamma-rays and optical R-band for Mrk 421.Comment: 10 pages, 7 figures, Proceedings of the SciNEGHE'0
Weak Boson Production Amplitude Zeros; Equalities of the Helicity Amplitudes
We investigate the radiation amplitude zeros exhibited by many Standard Model
amplitudes for triple weak gauge boson production processes. We show that
production amplitudes have especially rich structure in terms of
zeros, these amplitudes have zeros originating from several different sources.
It is also shown that TYPE I current null zone is the special case of the
equality of the specific helicity amplitudes.Comment: 27 pages, 12 figures, 2 table
Standards for the diagnosis and management of Complex Regional Pain Syndrome: Results of a European Pain Federation task force
Background: Complex Regional Pain Syndrome is a painful and disabling post-traumatic primary pain disorder. Acute and chronic CRPS are major clinical challenges. In Europe progress is hampered by significant heterogeneity in clinical practice. We sought to establish standards for the diagnosis and management of CPRS. Methods: The European Pain Federation established a pan-European task force of experts in CRPS who followed a four-stage consensus challenge process to produce mandatory quality standards worded as grammatically imperative (must-do) statements. Results: We developed 17 standards in 8 areas of care. There are 2 standards in diagnosis, 1 in multi-disciplinary care, 1 on assessment, 3 for care pathways, 1 on information and education, 4 in pain management, 3 in physical rehabilitation, and 2 on distress management. The standards are presented, summarised, and their generation and consequences discussed. Also presented are domains of practice for which no agreement on a standard could be reached. Areas of research needed to improve the validity and uptake of these standards are discussed. Conclusion: The European Pain Federation task force present 17 standards of the diagnosis and management of CPRS for use in Europe. These are considered achievable for most countries, and aspirational for a minority of countries depending on their healthcare resource and structures.Significance: This position statement summarizes expert opinion on acceptable standards for CRPS care in Europe
A tiered approach to the use of alternatives to animal testing for the safety assessment of cosmetics: Eye irritation
AbstractThe need for alternative approaches to replace the in vivo rabbit Draize eye test for evaluation of eye irritation of cosmetic ingredients has been recognised by the cosmetics industry for many years. Extensive research has lead to the development of several assays, some of which have undergone formal validation. Even though, to date, no single in vitro assay has been validated as a full replacement for the rabbit Draize eye test, organotypic assays are accepted for specific and limited regulatory purposes. Although not formally validated, several other in vitro models have been used for over a decade by the cosmetics industry as valuable tools in a weight of evidence approach for the safety assessment of ingredients and finished products. In light of the deadlines established in the EU Cosmetics Directive for cessation of animal testing for cosmetic ingredients, a COLIPA scientific meeting was held in Brussels on 30th January, 2008 to review the use of alternative approaches and to set up a decision-tree approach for their integration into tiered testing strategies for hazard and safety assessment of cosmetic ingredients and their use in products. Furthermore, recommendations are given on how remaining data gaps and research needs can be addressed
A Preoperative Clinical Risk Score Including C-Reactive Protein Predicts Histological Tumor Characteristics and Patient Survival after Surgery for Sporadic Non-Functional Pancreatic Neuroendocrine Neoplasms:An International Multicenter Cohort Study
Background: Oncological survival after resection of pancreatic neuroendocrine neoplasms (panNEN) is highly variable depending on various factors. Risk stratification with preoperatively available parameters could guide decision-making in multidisciplinary treatment concepts. C-reactive Protein (CRP) is linked to inferior survival in several malignancies. This study assesses CRP within a novel risk score predicting histology and outcome after surgery for sporadic non-functional panNENs. Methods: A retrospective multicenter study with national exploration and international validation. CRP and other factors associated with overall survival (OS) were evaluated by multivariable cox-regression to create a clinical risk score (CRS). Predictive values regarding OS, disease-specific survival (DSS), and recurrence-free survival (RFS) were assessed by time-dependent receiver-operating characteristics. Results: Overall, 364 patients were included. Median CRP was significantly higher in patients >60 years, G3, and large tumors. In multivariable analysis, CRP was the strongest preoperative factor for OS in both cohorts. In the combined cohort, CRP (cut-off >= 0.2 mg/dL; hazard-ratio (HR):3.87), metastases (HR:2.80), and primary tumor size >= 3.0 cm (HR:1.83) showed a significant association with OS. A CRS incorporating these variables was associated with postoperative histological grading, T category, nodal positivity, and 90-day morbidity/mortality. Time-dependent area-under-the-curve at 60 months for OS, DSS, and RFS was 69%, 77%, and 67%, respectively (all p <0.001), and the inclusion of grading further improved the predictive potential (75%, 84%, and 78%, respectively). Conclusions: CRP is a significant marker of unfavorable oncological characteristics in panNENs. The proposed internationally validated CRS predicts histological features and patient survival
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