108 research outputs found

    The Mersenne Low Hamming Combination Search Problem can be reduced to an ILP Problem

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    In 2017, Aggarwal, Joux, Prakash, and Santha proposed an innovative NTRU-like public-key cryptosystem that was believed to be quantum resistant, based on Mersenne prime numbers q = 2^N-1. After a successful attack designed by Beunardeau, Connolly, Geraud, and Naccache, the authors revised the protocol which was accepted for Round 1 of the Post-Quantum Cryptography Standardization Process organized by NIST. The security of this protocol is based on the assumption that a so-called Mersenne Low Hamming Combination Search Problem (MLHCombSP) is hard to solve. In this work, we present a reduction of MLHCombSP to Integer Linear Programming (ILP). This opens new research directions for assessing the concrete robustness of such cryptosystem. In particular, we uncover a new family of weak keys, for whose our attack runs in polynomial time

    Probabilistic analysis on Macaulay matrices over finite fields and complexity of constructing Gröbner bases

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    Gröbner basis methods are used to solve systems of polynomial equations over finite fields, but their complexity is poorly understood. In this work an upper bound on the time complexity of constructing a Gröbner basis and finding a solutions of a system is proved. A key parameter in this estimate is the degree of regularity of the leading forms of the polynomials. Therefore, we provide an upper bound on the degree of regularity for a sufficiently overdetermined system of forms over any finite field. The bound holds with probability tending to 1 and depends only on the number of variables, the number of polynomials, and their degrees. Our results imply that sufficiently overdetermined systems of polynomial equations are solvable in polynomial time with high probability

    Long-term complete response in a patient with liver metastases from breast cancer treated with metronomic chemotherapy

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    Background. Preclinical studies have shown that several chemotherapeutic agents at low doses may affect the vascular system. Here we report the case of a patient with long-term cancer control by metronomic chemotherapy. Case presentation. A 62-year-old woman with breast cancer underwent a left mastectomy in July 2007. For a liver metastasis she was given first-line chemotherapy with doxorubicin plus paclitaxel every 21 days. A CT scan after the sixth cycle showed a partial response. It was decided to stop the treatment with doxorubicin and paclitaxel, and start metronomic therapy with cyclophosphamide 50 mg daily orally and methotrexate 2.5 mg twice daily, 2 days a week. After 6 months of this maintenance treatment, CT scan showed a complete response. We examined the expression of vascular endothelial growth factor receptor 2 (VEGFR2) in histological sections of the primary tumor of our patient, finding evidence of overexpression of the receptor. The metronomic treatment is still ongoing, and after 60 months the patient maintains a complete response. Conclusion. This clinical case highlights how suitable metronomic chemotherapy can be used as maintenance therapy, allowing long-term treatment with no significant toxicity. This case suggests that the level of VEGFR2 is predictive of best response to antiangiogenic therapy

    Separate episodes of capillary leak syndrome and pulmonary hypertension after adjuvant gemcitabine and three years later after nab-paclitaxel for metastatic disease

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    Background: Systemic capillary leak syndrome is a rare disease with a high mortality rate. This syndrome is characterised by generalised edema, hypotension, hemoconcentration, and hypoproteinemia. The cause is the sudden onset of capillary hyperpermeability with extravasations of plasma from the intravascular to the extravascular compartment. We present the case of a patient who experienced two episodes of systemic capillary leak syndrome and pulmonary hypertension; the first after gemcitabine in an adjuvant setting and the second three years later after treatment with nab-paclitaxel for metastatic disease.Case presentation: A 65-year-old patient underwent a pancreatectomy in January 2010 for ductal carcinoma (pT3 N0 M0, stage IIa), followed by adjuvant chemotherapy. Seven days after the last cycle, she developed dyspnea associated with orthopnea and cough. A transthoracic cardiac ecocolordoppler was performed, with evidence of pulmonary hypertension (58 mmHg). Blood tests showed an increase in creatinine, pro-BNP and D-Dimer. She began high-dose diuretic therapy combined with cortisone. After a month, the patient was eupneic and the anasarca had resolved. We decided gradually to reduce the steroid and diuretic therapy. After ten days of the reduction, the patient began to re-present the same symptoms after treatment with gemcitabine. Corticosteroid therapy was restored with rapid clinical benefit and decreased pro-BNP after a week of treatment. After two years, the disease returned. As a first line treatment, it was decided to use nab-paclitaxel 100 mg/m2 weekly. After two doses, followed by approximately 14 days of treatment, the patient developed acute respiratory distress syndrome. The clinical suspicion was a relapse of capillary leak syndrome and treatment with a high-dose diuretic (furosemide 250 mg daily) was started combined with cortisone (40 mg methylprednisolone). The patient showed a progressive clinical benefit.Conclusions: In patients treated with gemcitabine and nab-paclitaxel who experience a sudden onset of diffuse edema with respiratory distress, capillary leak syndrome should be suspected. Immediate treatment with corticosteroids may be life-saving. © 2013 Casadei Gardini et al.; licensee BioMed Central Ltd

    Multicentric survey on dose reduction/interruption of cancer drug therapy in 12.472 patients: Indicators of suspected adverse reactions

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    Antiblastic drugs have a high number of potential side-effects. Paradoxically, according to the National Network of Pharmacovigilance, the number of reported adverse reactions to these agents is proportionally lower than that registered for non antiblastic drugs. Critical phenomena such as treatment interruptions and significant dose reductions within the first two months of use may be indicators of adverse drug reactions. The aim of the present study was to increase our knowledge of pharmacovigilance to facilitate the actions taken to improve the risk-benefit profile of cancer drugs and, consequently, their safety. This retrospective observational survey was carried out on prescriptions from 1st January 2012 to 31st December 2012.Dose reductions of more than 10% during the first 90 days of therapy were considered as a surrogate indicator of an adverse reaction. Dose interruptions during the first 60 days of therapy were taken into consideration. Of the12,472 patients 1,248 underwent a dose reduction. The drugs that most often required a dose reduction were paclitaxel and oxaliplatin (17.4% and 17.3%, respectively), docetaxel (14.8%), carboplatin (15%), fluorouracil (10.7%) and, among oral medications, capecitabine (6.9%). Of the 1896 patients treated with the same drugs, 9.7% interrupted treatment. Patients required a lower dose reduction than that reported by other authors. Around 15% of cases underwent a 30% dose reduction within three months of starting therapy, indicating a possible adverse reaction. Constant monitoring of dose prescription and continuous training of medical and nursing staff are clearly needed to increase awareness of the importance of reporting adverse events.Antiblastic drugs have a high number of potential side-effects. Paradoxically, according to the National Network of Pharmacovigilance, the number of reported adverse reactions to these agents is proportionally lower than that registered for non antiblastic drugs. Critical phenomena such as treatment interruptions and significant dose reductions within the first two months of use may be indicators of adverse drug reactions. The aim of the present study was to increase our knowledge of pharmacovigilance to facilitate the actions taken to improve the risk-benefit profile of cancer drugs and, consequently, their safety. This retrospective observational survey was carried out on prescriptions from 1st January 2012 to 31st December 2012. Dose reductions of more than 10% during the first 90 days of therapy were considered as a surrogate indicator of an adverse reaction. Dose interruptions during the first 60 days of therapy were taken into consideration. Of the12,472 patients 1,248 underwent a dose reduction. The drugs that most often required a dose reduction were paclitaxel and oxaliplatin (17.4% and 17.3%, respectively), docetaxel (14.8%), carboplatin (15%), fluorouracil (10.7%) and, among oral medications, capecitabine (6.9%). Of the 1896 patients treated with the same drugs, 9.7% interrupted treatment. Patients required a lower dose reduction than that reported by other authors. Around 15% of cases underwent a 30% dose reduction within three months of starting therapy, indicating a possible adverse reaction. Constant monitoring of dose prescription and continuous training of medical and nursing staff are clearly needed to increase awareness of the importance of reporting adverse events

    Effects of metformin on clinical outcome in diabetic patients with advanced HCC receiving sorafenib

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    Background and objective: Several studies have reported an association between type 2 diabetes mellitus and hepatocellular carcinoma (HCC). Data from several retrospective studies and meta-analyses have highlighted a reduction of about 50% in the risk of developing HCC in cirrhotic patients treated with metformin for diabetes. The aim of this study was to evaluate the different outcomes of patients who received or did not receive metformin during treatment with sorafenib.Methods: We analyzed 93 patients consecutively treated with sorafenib. Forty-two (45.2%) patients were diabetic, of whom 31 were on metformin. Progression-free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method and compared with the log-rank test.Results: The concomitant use of sorafenib and metformin was associated with a median PFS of 2.6 months (95% CI 1.9-3.3) compared to 5.0 months (95% CI 2.5-8.2) for patients receiving sorafenib alone (p = 0.029). The median OS of patients treated with the combination was 10.4 months (95% CI 3.9-14.4) compared to 15.1 months (95% CI 11.7-17.8) for those who were not given metformin (p = 0.014).Conclusions: Our findings could be the result of increased tumor aggressiveness and resistance to sorafenib in metformin-treated patients

    L. Evidence of spatial variation of the polarized thermal dust spectral energy distribution and implications for CMB B-mode analysis

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    Planck Collaboration.The characterization of the Galactic foregrounds has been shown to be the main obstacle in thechallenging quest to detect primordial B-modes in the polarized microwave sky. We make use of the Planck-HFI 2015 data release at high frequencies to place new constraints on the properties of the polarized thermal dust emission at high Galactic latitudes. Here, we specifically study the spatial variability of the dust polarized spectral energy distribution (SED), and its potential impact on the determination of the tensor-to-scalar ratio, r. We use the correlation ratio of the angular power spectra between the 217 and 353 GHz channels as a tracer of these potential variations, computed on different high Galactic latitude regions, ranging from 80% to 20% of the sky. The new insight from Planck data is a departure of the correlation ratio from unity that cannot be attributed to a spurious decorrelation due to the cosmic microwave background, instrumental noise, or instrumental systematics. The effect is marginally detected on each region, but the statistical combination of all the regions gives more than 99% confidence for this variation in polarized dust properties. In addition, we show that the decorrelation increases when there is a decrease in the mean column density of the region of the sky being considered, and we propose a simple power-law empirical model for this dependence, which matches what is seen in the Planck data. We explore the effect that this measured decorrelation has on simulations of the BICEP2-Keck Array/Planck analysis and show that the 2015 constraints from these data still allow a decorrelation between the dust at 150 and 353 GHz that is compatible with our measured value. Finally, using simplified models, we show that either spatial variation of the dust SED or of the dust polarization angle are able to produce decorrelations between 217 and 353 GHz data similar to the values we observe in the data.The Planck Collaboration acknowledges the support of: ESA; CNES, and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MINECO, J.A., and RES (Spain); Tekes, AoF, and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); ERC and PRACE (EU). The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement No. 267934.Peer Reviewe

    Euclid Near Infrared Spectrometer and Photometer instrument concept and first test results obtained for different breadboards models at the end of phase C

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    The Euclid mission objective is to understand why the expansion of the Universe is accelerating through by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESA's Cosmic Vision program with its launch planned for 2020 (ref [1]). The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (900- 2000nm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a Silicon carbide structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with molybdenum and aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase C (Detailed Design Review), the expected performance, the technological key challenges and preliminary test results obtained for different NISP subsystem breadboards and for the NISP Structural and Thermal model (STM)

    Research and Development for Near Detector Systems Towards Long Term Evolution of Ultra-precise Long-baseline Neutrino Experiments

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    With the discovery of non-zero value of Ξ13\theta_{13} mixing angle, the next generation of long-baseline neutrino (LBN) experiments offers the possibility of obtaining statistically significant samples of muon and electron neutrinos and anti-neutrinos with large oscillation effects. In this document we intend to highlight the importance of Near Detector facilities in LBN experiments to both constrain the systematic uncertainties affecting oscillation analyses but also to perform, thanks to their close location, measurements of broad benefit for LBN physics goals. A strong European contribution to these efforts is possible

    Planck intermediate results. LV. Reliability and thermal properties of high-frequency sources in the Second Planck Catalogue of Compact Sources

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    We describe an extension of the most recent version of the Planck Catalogue of Compact Sources (PCCS2), produced using a new multi-band Bayesian Extraction and Estimation Package (BeeP). BeeP assumes that the compact sources present in PCCS2 at 857 GHz have a dust-like spectral energy distribution (SED), which leads to emission at both lower and higher frequencies, and adjusts the parameters of the source and its SED to fit the emission observed in Planck's three highest frequency channels at 353, 545, and 857 GHz, as well as the IRIS map at 3000 GHz. In order to reduce confusion regarding diffuse cirrus emission, BeeP's data model includes a description of the background emission surrounding each source, and it adjusts the confidence in the source parameter extraction based on the statistical properties of the spatial distribution of the background emission. BeeP produces the following three new sets of parameters for each source: (a) fits to a modified blackbody (MBB) thermal emission model of the source; (b) SED-independent source flux densities at each frequency considered; and (c) fits to an MBB model of the background in which the source is embedded. BeeP also calculates, for each source, a reliability parameter, which takes into account confusion due to the surrounding cirrus. This parameter can be used to extract sub-samples of high-frequency sources with statistically well-understood properties. We define a high-reliability subset (BeeP/base), containing 26 083 sources (54.1% of the total PCCS2 catalogue), the majority of which have no information on reliability in the PCCS2. We describe the characteristics of this specific high-quality subset of PCCS2 and its validation against other data sets, specifically for: the sub-sample of PCCS2 located in low-cirrus areas; the Planck Catalogue of Galactic Cold Clumps; the Herschel GAMA15-field catalogue; and the temperature- and spectral-index-reconstructed dust maps obtained with Planck's Generalized Needlet Internal Linear Combination method. The results of the BeeP extension of PCCS2, which are made publicly available via the Planck Legacy Archive, will enable the study of the thermal properties of well-defined samples of compact Galactic and extragalactic dusty sources
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