Активные фильтры аналогового тракта построителя сейсмических разрезов

Secure, anonymous and unobservable communication is becoming increasingly important due to the gradual erosion of privacy in many aspects of everyday life. This prompts the need for various anonymity- and privacy-enhancing techniques, e.g., group signatures, anonymous e-cash and secret handshakes. In this paper, we investigate an interesting and practical cryptographic construct Oblivious Signature-Based Envelopes (OS-BEs) recently introduced in [15]. OSBEs are very useful in anonymous communication since they allow a sender to communicate information to a receiver such that the receiver s rights (or roles) are unknown to the sender. At the same time, a receiver can obtain the information only if it is authorized to access it. This makes OSBEs a natural fit for anonymity-oriented and privacy-preserving applications, such as Automated Trust Negotiation and Oblivious Subscriptions. Previous results yielded three OSBE constructs: one based on RSA and two based on Identity-Based Encryption (IBE). Our work focuses on the ElGamal signature family: we succeed in constructing practical and secure OSBE schemes for several well-known signature schemes, including: Schnorr, Nyberg-Rueppel, ElGamal and DSA. As experiments with the prototype implementation il-lustrate, our schemes are more efficient than previous techniques. Furthermore, we show that some OSBE schemes, despite offering affiliation privacy for the receiver, introduce no additional cost over schemes that do not offer this feature

Quasi-stationary States of Two-Dimensional Electron Plasma Trapped in Magnetic Field

We have performed numerical simulations on a pure electron plasma system under a strong magnetic field, in order to examine quasi-stationary states that the system eventually evolves into. We use ring states as the initial states, changing the width, and find that the system evolves into a vortex crystal state from a thinner-ring state while a state with a single-peaked density distribution is obtained from a thicker-ring initial state. For those quasi-stationary states, density distribution and macroscopic observables are defined on the basis of a coarse-grained density field. We compare our results with experiments and some statistical theories, which include the Gibbs-Boltzmann statistics, Tsallis statistics, the fluid entropy theory, and the minimum enstrophy state. From some of those initial states, we obtain the quasi-stationary states which are close to the minimum enstrophy state, but we also find that the quasi-stationary states depend upon initial states, even if the initial states have the same energy and angular momentum, which means the ergodicity does not hold.Comment: 9 pages, 7 figure

Low-dose glucocorticoid treatment affects multiple aspects of intermediary metabolism in healthy humans: a randomised controlled trial

AIM/HYPOTHESIS: To assess whether low-dose glucocorticoid treatment induces adverse metabolic effects, as is evident for high glucocorticoid doses. METHODS: In a randomised placebo-controlled double-blind (participants and the investigators who performed the studies and assessed the outcomes were blinded) dose-response intervention study, 32 healthy men (age 22 +/- 3 years; BMI 22.4 +/- 1.7 kg/m(2)) were allocated to prednisolone 7.5 mg once daily (n = 12), prednisolone 30 mg once daily (n = 12), or placebo (n = 8) for 2 weeks using block randomisation. Main outcome measures were glucose, lipid and protein metabolism, measured by stable isotopes, before and at 2 weeks of treatment, in the fasted state and during a two-step hyperinsulinaemic clamp conducted in the Clinical Research Unit of the Academic Medical Centre, Amsterdam, the Netherlands RESULTS: Prednisolone, compared with placebo, dose dependently and significantly increased fasting plasma glucose levels, whereas only prednisolone 30 mg increased fasting insulin levels (29 +/- 15 pmol/l). Prednisolone 7.5 mg and prednisolone 30 mg decreased the ability of insulin to suppress endogenous glucose production (by 17 +/- 6% and 46 +/- 7%, respectively, vs placebo). Peripheral glucose uptake was not reduced by prednisolone 7.5 mg, but was decreased by prednisolone 30 mg by 34 +/- 6% (p < 0.0001). Compared with placebo, prednisolone treatment tended to decrease lipolysis in the fasted state (p = 0.062), but both prednisolone 7.5 mg and prednisolone 30 mg decreased insulin-mediated suppression of lipolysis by 11 +/- 5% and 34 +/- 6%, respectively. Finally, prednisolone treatment increased whole-body proteolysis during hyperinsulinaemia, which tended to be driven by prednisolone 30 mg (5 +/- 2%; p = 0.06). No side effects were reported by the study participants. All participants completed the study and were analysed. CONCLUSIONS/INTERPRETATION: Not only at high doses but also at low doses, glucocorticoid therapy impaired intermediary metabolism by interfering with the metabolic actions of insulin on liver and adipose tissue. These data indicate that even low-dose glucocorticoids may impair glucose tolerance when administered chronically. TRIAL REGISTRATION: ISRCTN83991850

Slow relaxation in the two dimensional electron plasma under the strong magnetic field

We study slow relaxation processes in the point vortex model for the two-dimensional pure electron plasma under the strong magnetic field. By numerical simulations, it is shown that, from an initial state, the system undergoes the fast relaxation to a quasi-stationary state, and then goes through the slow relaxation to reach a final state. From analysis of simulation data, we find (i) the time scale of the slow relaxation increases linearly to the number of electrons if it is measured by the unit of the bulk rotation time, (ii) during the slow relaxation process, each electron undergoes an superdiffusive motion, and (iii) the superdiffusive motion can be regarded as the Levy flight, whose step size distribution is of the power law. The time scale that each electron diffuses over the system size turns out to be much shorter than that of the slow relaxation, which suggests that the correlation among the superdiffusive trajectories is important in the slow relaxation process.Comment: 11pages, 19 figures. Submitted to J. Phys. Soc. Jp

How dentists and oral and maxillofacial surgeons deal with tooth extraction without a valid clinical indication

Objectives: This study pertains to a secondary data analysis aimed at determining differences between oral and maxillofacial surgeons (OMFSs) and dentists handling dental extractions without an evident clinical indication. Study design: A survey of 18 questions was conducted among 256 OMFSs in the Netherlands and a random sample of 800 dentists Respondents could answer the questions in writing or online. The data was collected in the period from November 2019 to January 2020, during which two reminders were sent. Analysis of the data took place via descriptive statistics and Chi Square test. Results: The response rate was 28.1% (n = 72) for OMFSs and 30.3% (n = 242) for dentists. In the past three years, 81.9% (n = 59) of the OMFSs and 68.0% (n = 164) of the dentists received a request for extraction without a clinical indication. The most common reasons were financial and severe dental fear (OMFSs: 64.9 and 50.9% vs dentists: 77.4 and 36.5%). Dentists were significantly more likely (75.6%, n = 114) than OMFS (60.7%, n = 34) to comply with their last extraction request without a clinical indication. Almost none of them regretted the extraction afterwards. As for the request itself, it was found that 17.5% (n = 10) of the OMFSs and 12.5% (n = 20) of the dentists did not check for patients’ mental competency (p = 0.352). Conclusions: Given that most of the interviewed dental professionals complied with non-dental extraction requests when such extractions are ethically and legally precarious, recommendations for handling such requests are greatly needed

Mucopolysaccharidosis type VI phenotypes-genotypes and antibody response to galsulfase

Background: Mucopolysaccharidosis type VI (Maroteaux-Lamy syndrome; MPS VI) is an autosomal recessive lysosomal storage disorder in which deficiency of N-acetylgalactosamine 4-sulfatase (arylsulfatase B; ARSB) leads to the storage of glycosaminoglycans (GAGs) in connective tissue. The genotype-phenotype correlation has been addressed in several publications but the picture is not complete. Since 2007, enzyme-replacement therapy (ERT) has been available for patients with MPS VI in the Netherlands. The purpose of our study was to learn more about the genotype-phenotype correlations in MPS VI and the antibody response to ERT with galsulfase (recombinant human arylsulfatase B). Methods. We identified ARSB mutations in 12 patients and used site-directed mutagenesis to study their effect. Antibody levels to galsulfase were measured using ELISA and a semi-quantitative immunoprecipitation method. We assessed the in vitro inhibitory effect of antibodies on galsulfase uptake and their effect on clinical outcome. Results: Five patients had a rapidly progressive phenotype and seven a slowly progressive phenotype. In total 9 pathogenic mutations were identified including 4 novel mutations (N301K, V332G, A237D, and c.1142 + 2 T > C) together composing 8 pathogenic genotypes. Most mutations appeared not to affect the synthesis of ARSB (66 kD precursor), but to hamper its maturation (43 kD ARSB). Disease severity was correlated with urinary GAG excretion. All patients developed antibodies to galsulfase within 26 weeks of treatment. It was demonstrated that these antibodies can inhibit the uptake of galsulfase in vitro. Conclusions: The clinical phenotypes and the observed defects in the biosynthesis of ARSB show that some of the mutations that we identified are clearly more severe than others. Patients receiving galsulfase as enzyme-replacement therapy can develop antibodies towards the therapeutic protein. Though most titers are modest, they can exceed a level at which they potentially affect the clinical outcome of enzyme-replacement therapy

SRSF2 Mutations in Uveal Melanoma: A Preference for In-Frame Deletions?

Background: Uveal melanoma (UM) is the most common primary ocular malignancy in adults in the Western world. UM with a mutation in SF3B1, a spliceosome gene, is characterized by three or more structural changes of chromosome 1, 6, 8, 9, or 11. Also UM without a mutation in SF3B1 harbors similar chromosomal aberrations. Since, in addition to SF3B1, mutations in U2AF1 and SRSF2 have also been observed in hematological malignancies, UM without a SF3B1 mutation—but with the characteristic chromosomal pattern—might harbor mutations in one of these genes. Methods: 42 UMs were selected based on their chromosomal profile and wildtype SF3B1 status. Sanger sequencing covering the U2AF1 (exon 2 and 7) hotspots and SRSF2 (exon 1 and 2) was performed on DNA extracted from tumor tissue. Data of three UM with an SRSF2 mutation was extracted from the The Cancer Genome Atlas (TCGA). Results: Heterozygous in-frame SRSF2 deletions affecting amino acids 92–100 were detected in two UMs (5%) of 42 selected tumors and in three TGCA UM specimens. Both the UM with an SRSF2 mutation from our cohort and the UM samples from the TCGA showed more than four structural chromosomal aberrations including (partial) gain of chromosome 6 and 8, although in two TCGA UMs monosomy 3 was observed. Conclusions: Whereas in myelodysplastic syndrome predominantly missense SRSF2 mutations are described, the observed SRSF2 mutations in UM are all in-frame deletions of 8–9 amino acids. This suggests that the R625 missense SF3B1 mutations and SRSF2 mutations in UM are different compared to the spliceosome gene mutations in hematological cancers, and probably target a different, as yet unknown, set of genes involved in uv

Security and Privacy Issues in Wireless Mesh Networks: A Survey

This book chapter identifies various security threats in wireless mesh network (WMN). Keeping in mind the critical requirement of security and user privacy in WMNs, this chapter provides a comprehensive overview of various possible attacks on different layers of the communication protocol stack for WMNs and their corresponding defense mechanisms. First, it identifies the security vulnerabilities in the physical, link, network, transport, application layers. Furthermore, various possible attacks on the key management protocols, user authentication and access control protocols, and user privacy preservation protocols are presented. After enumerating various possible attacks, the chapter provides a detailed discussion on various existing security mechanisms and protocols to defend against and wherever possible prevent the possible attacks. Comparative analyses are also presented on the security schemes with regards to the cryptographic schemes used, key management strategies deployed, use of any trusted third party, computation and communication overhead involved etc. The chapter then presents a brief discussion on various trust management approaches for WMNs since trust and reputation-based schemes are increasingly becoming popular for enforcing security in wireless networks. A number of open problems in security and privacy issues for WMNs are subsequently discussed before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the author's previous submission in arXiv submission: arXiv:1102.1226. There are some text overlaps with the previous submissio