360 research outputs found

    Elligator : elliptic-curve points indistinguishable from uniform random strings

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    Censorship-circumvention tools are in an arms race against censors. The censors study all traffic passing into and out of their controlled sphere, and try to disable censorship-circumvention tools without completely shutting down the Internet. Tools aim to shape their traffic patterns to match unblocked programs, so that simple traffic profiling cannot identify the tools within a reasonable number of traces; the censors respond by deploying rewalls with increasingly sophisticated deep-packet inspection. Cryptography hides patterns in user data but does not evade censorship if the censor can recognize patterns in the cryptography itself. In particular, elliptic-curve cryptography often transmits points on known elliptic curves, and those points are easily distinguishable from uniform random strings of bits. This paper introduces high-security high-speed elliptic-curve systems in which elliptic-curve points are encoded so as to be indistinguishable from uniform random strings. At a lower level, this paper introduces a new bijection between strings and about half of all curve points; this bijection is applicable to every odd-characteristic elliptic curve with a point of order 2, except for curves of j-invariant 1728. This paper also presents guidelines to construct, and two examples of, secure curves suitable for these encodings

    The Barkhatny ultramafic-mafic massif (Kuznetsk Alatau Ridge, SW Siberia): structural and compositional evolutions of rocks

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    A complex of petrographic and petrofabric analyses that was carried out for rocks from an ultramafic-mafic massif of the Barkhatnaya Mountain in the Northern part of the Kuznetsk Alatau allowed us to prove that internal anisotropy of mineral aggregates had deformation-type evolution, which indicates possible plastic exhumation of lithosphere mantle fragments into upper crust levels. Additional mineralogical and geochemical researches of the basic component point out high possibility of multistage model for obduction of ophiolite association segments proposed for this region

    Поражение почек при системной красной волчанке: современные представления о патогенезе, клинике, подходы к лечению

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    The paper deals with the pathogenesis, clinical picture, and treatment of renal involvement in patients with systemic lupus erythematosus (SLE). It is noted that at the onset of the disease, there are signs of renal involvement in 25-50% of patients with SLE; they are further detectable in almost 60% of adults and in 80% of children. The types of renal lesion are described in SLE. The pathogenesis of SLE as a whole is examined on a model of lupus nephritis. The morphological classification of lupus nephritis, the specific features of major nephrological syndromes, and the clinical types (active and inactive) are given. Treatment policy is stated to depend on the activity of the disease, the clinical and morphological type of lupus nephritis. Current immunosuppressive therapy can reduce the proportion of patients with terminal renal failure on the one hand and shows the prognostic value of renal involvement for the course of the disease as a whole, on the other. New immunological involvement strategies are associated with total irradiation of the lymphoid system or marrow, followed by stem cell grafting.Рассмотрены патогенез, клиника и лечение поражения почек у больных системной красной волчанкой (СКВ). Отмечено, что, если в начале заболевания признаки поражения почек имеются у 25-50% больных СКВ, то в дальнейшем они определяется почти у 60% взрослых и 80% детей. Описаны варианты поражения почек при СКВ. Патогенез СКВ в целом рассмотрен на модели волчаночного нефрита. Представлены морфологическая классификация волчаноч-ного нефрита, особенности основных нефрологических синдромов, клинические варианты (активный и неактивный). Указано, что лечебная тактика зависит от активности болезни, клинического и морфологического варианта волчаночного нефрита. Возможности современной иммуносупрессивной терапии, с одной стороны, позволили снизить долю больных с терминальной почечной недостаточностью, а с другой - продемонстрировали прогностическую важность поражения почек для течения болезни в целом. Новые стратегии иммунологического вмешательства связаны с тотальным облучением лимфоидной системы или костного мозга с последующей пересадкой стволовых клеток

    Interactive technologies in electronic educational resources

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    © by The Author(s). Modern professional education in the transition to a tiered system of specialists training is focused not on the transfer of ready knowledge but on teaching to find this knowledge and to apply them in situations close to the professional conditions. The educational process, relying on use of interactive methods of teaching, which is organized with involvement of all students of the group, without exception, in the learning process, facilitates this. The problem of introduction of interactive forms of teaching in the educational process of higher education institutions is considered in the article, the experience of use of interactive technologies in electronic educational resources of physico-mathematical faculty of the Elabuga Institute of the Kazan (Volga region) Federal University is presented. On the basis of the received results the importance of the developed electronic educational resources in the context of the competence-based approach to training of bachelors, increase of their competitiveness is proved

    LET\u27S COLLABORATE, BUT I WILL BE THE FIRST AUTHOR! EXPLORING THE IMPORTANCE OF THE FIRST AUTHORSHIP FOR IS RESEARCHERS

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    Collaboration among researchers is typically seen as the quintessence of academic excellence, leading to improvements in the research quality, capitalization on the diversity of perspectives and gains in productivity. Despite these benefits, many research teams find themselves torn by competition, antagonism and resentment. Desire to be the first author and resultant underperformance of non-first co-authors is often at the root of these conflicts. At the same time little is known about what motivates researchers in general and IS researchers in particular to engage as first authors. To fill this gap, this study uses survey methodology to explore the attitudes of IS researchers and their resulting behavior when it comes to authors order. Qualitative and quantitative evidence collected from 398 IS researchers is used to support our analysis. We find that researchers\u27 desire to be the first authors is mainly driven by such determinants as career aspirations, visibility, leadership and sense of ownership, and less so by the desire to satisfy their self-esteem and self-actualization needs. In addition, the value placed on being the first author appears to be the function of researchers? career level, with Ph.D. students attaching significantly higher value to it than senior scholars

    Why Participate in an Online Social Network? An Empirical Analysis

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    Despite their enormous success the motivation behind user participation in Online Social Networks is still little understood. This study explores a variety of possible incentives and provides an empirical evaluation of their subjective relevance. The analysis is based on survey data from 129 test subjects. Using Structural Equation Modeling, we identified that the satisfaction of the needs for belongingness and the esteem needs through self-presentation together with peer pressure are the main drivers of participation. The analysis of a sub-sample of active users pointed out the satisfaction of the cognitive needs as an additional participation determinant. Based on these findings, recommendations for online social network providers are made

    Matter and physical anisotropy of ultramafites of the Barkhatny massif (Kuznetsk Alatau ridge, Western Siberia) as criteria of their mineral potential for geological prospecting works

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    A complex of petrographic, petrofabric, and paleomagnetic analyses that was carried out for rocks from an ultrabasic massif of the Barkhatnaya Mountain in the Northern part of the Kuznetsk Alatau allowed us to prove that internal anisotropy of mineral aggregates had deformation-type evolution, which indicates possible plastic exhumation of lithosphere mantle fragments into upper crust levels. Complete conformity of geophysical and petrofabric parameters points out high possibility of multistage model for obduction of ophiolite association segments proposed for this region. Taking into account specifics of minerageny for such complexes (chromite ores and noble metals, asbestos and nephrites), we offer a new technology for geological prospecting works at the stage of estimating mineral potential of such geological objects, which is based on the presence of differently oriented systems of mineral plane orientation.Проведенный нами комплекс структурно-петрологических и палеомагнитных исследований для ультрабазитов Бархатно- го массива на северном склоне Кузнецкого Алатау подтверждает, что внутренняя анизотропия минеральных агрегатов име- ла деформационную эволюцию, которая указывает на возможную пластическую эксгумацию фрагментов мантии литосферы в верхние горизонты земной коры. Полное соответствие геофизических и петроструктурных параметров отмечает высокую вероятность многостадийной обдукции фрагментов офиолитовой ассоциации, предлагаемой для этого региона. Принимая во внимание особенности минерагении (хромитовые руды и благородные металлы, асбест и нефрит) для таких комплексов мы предлагаем новые методы геологоразведочных работ на стадии оценки рудоносности геологических объектов, которые харак- теризуются дискретными вариациями пространственной ориентировки элементов текстурной анизотропии пород

    Specifics of geological composition, geochemistry and geochronology of rocks from the Kresty alkaline-ultrabasic massif (Maimecha-Kotui province, Polar Siberia)

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    In this work, we demonstrate new data that allows us to accurate geochronological ranges of formation of the Kresty alkaline-ultrabasic massif, which is considered to be a satellite of the Gulinian giant pluton. We also interpreted geological, geochemical and isotope-geochemical data obtained earlier for major varieties of this volcanic-plutonic association taking into account new geochronological results, as well as considered new aspects/information on matter source of alkaline-ultrabasic massifs from this province. One of the main aspects is interaction of Siberian super plume matter with hosting substrate of Siberian craton continental crust

    Compulsive methamphetamine taking in the presence of punishment is associated with increased oxytocin expression in the nucleus accumbens of rats

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    Methamphetamine addiction is mimicked in rats that self-administer the drug. However, these self-administration (SA) models do not include adverse consequences that are necessary to reach a diagnosis of addiction in humans. Herein, we measured genome-wide transcriptional consequences of methamphetamine SA and footshocks in the rat brain. We trained rats to self-administer methamphetamine for 20 days. Thereafter, lever-presses for methamphetamine were punished by mild footshocks for 5 days. Response-contingent punishment significantly reduced methamphetamine taking in some rats (shock-sensitive, SS) but not in others (shock-resistant, SR). Rats also underwent extinction test at one day and 30 days after the last shock session. Rats were euthanized one day after the second extinction test and the nucleus accumbens (NAc) and dorsal striatum were collected to measure gene expression with microarray analysis. In the NAc, there were changes in the expression of 13 genes in the SRvsControl and 9 genes in the SRvsSS comparison. In the striatum, there were 9 (6 up, 3 down) affected genes in the SRvsSS comparison. Among the upregulated genes was oxytocin in the NAc and CARTpt in the striatum of SR rats. These observations support a regional role of neuropeptides in the brain after a long withdrawal interval when animals show incubation of methamphetamine craving

    Chronic Methamphetamine Administration Causes Differential Regulation of Transcription Factors in the Rat Midbrain

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    Methamphetamine (METH) is an addictive and neurotoxic psychostimulant widely abused in the USA and throughout the world. When administered in large doses, METH can cause depletion of striatal dopamine terminals, with preservation of midbrain dopaminergic neurons. Because alterations in the expression of transcription factors that regulate the development of dopaminergic neurons might be involved in protecting these neurons after toxic insults, we tested the possibility that their expression might be affected by toxic doses of METH in the adult brain. Male Sprague-Dawley rats pretreated with saline or increasing doses of METH were challenged with toxic doses of the drug and euthanized two weeks later. Animals that received toxic METH challenges showed decreases in dopamine levels and reductions in tyrosine hydroxylase protein concentration in the striatum. METH pretreatment protected against loss of striatal dopamine and tyrosine hydroxylase. In contrast, METH challenges caused decreases in dopamine transporters in both saline- and METH-pretreated animals. Interestingly, METH challenges elicited increases in dopamine transporter mRNA levels in the midbrain in the presence but not in the absence of METH pretreatment. Moreover, toxic METH doses caused decreases in the expression of the dopamine developmental factors, Shh, Lmx1b, and Nurr1, but not in the levels of Otx2 and Pitx3, in saline-pretreated rats. METH pretreatment followed by METH challenges also decreased Nurr1 but increased Otx2 and Pitx3 expression in the midbrain. These findings suggest that, in adult animals, toxic doses of METH can differentially influence the expression of transcription factors involved in the developmental regulation of dopamine neurons. The combined increases in Otx2 and Pitx3 expression after METH preconditioning might represent, in part, some of the mechanisms that served to protect against METH-induced striatal dopamine depletion observed after METH preconditioning
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