7,090 research outputs found

    Quantum-proof randomness extractors via operator space theory

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    Quantum-proof randomness extractors are an important building block for classical and quantum cryptography as well as device independent randomness amplification and expansion. Furthermore they are also a useful tool in quantum Shannon theory. It is known that some extractor constructions are quantum-proof whereas others are provably not [Gavinsky et al., STOC'07]. We argue that the theory of operator spaces offers a natural framework for studying to what extent extractors are secure against quantum adversaries: we first phrase the definition of extractors as a bounded norm condition between normed spaces, and then show that the presence of quantum adversaries corresponds to a completely bounded norm condition between operator spaces. From this we show that very high min-entropy extractors as well as extractors with small output are always (approximately) quantum-proof. We also study a generalization of extractors called randomness condensers. We phrase the definition of condensers as a bounded norm condition and the definition of quantum-proof condensers as a completely bounded norm condition. Seeing condensers as bipartite graphs, we then find that the bounded norm condition corresponds to an instance of a well studied combinatorial problem, called bipartite densest subgraph. Furthermore, using the characterization in terms of operator spaces, we can associate to any condenser a Bell inequality (two-player game) such that classical and quantum strategies are in one-to-one correspondence with classical and quantum attacks on the condenser. Hence, we get for every quantum-proof condenser (which includes in particular quantum-proof extractors) a Bell inequality that can not be violated by quantum mechanics.Comment: v3: 34 pages, published versio

    Neutral helium spectral lines in dense plasmas

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    Variations on Classical and Quantum Extractors

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    Many constructions of randomness extractors are known to work in the presence of quantum side information, but there also exist extractors which do not [Gavinsky {\it et al.}, STOC'07]. Here we find that spectral extractors ψ\psi with a bound on the second largest eigenvalue λ2(ψψ)\lambda_{2}(\psi^{\dagger}\circ\psi) are quantum-proof. We then discuss fully quantum extractors and call constructions that also work in the presence of quantum correlations decoupling. As in the classical case we show that spectral extractors are decoupling. The drawback of classical and quantum spectral extractors is that they always have a long seed, whereas there exist classical extractors with exponentially smaller seed size. For the quantum case, we show that there exists an extractor with extremely short seed size d=O(log(1/ϵ))d=O(\log(1/\epsilon)), where ϵ>0\epsilon>0 denotes the quality of the randomness. In contrast to the classical case this is independent of the input size and min-entropy and matches the simple lower bound dlog(1/ϵ)d\geq\log(1/\epsilon).Comment: 7 pages, slightly enhanced IEEE ISIT submission including all the proof

    Islam dan Kebudayaan Melayu di Era Globalisasi di Malaysia

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    Sejarah telah menunjukkan bahwa dunia Melayu-Islam merupakan pusat peradaban, pusat perkembangan budaya dan pusat perdagangan yang penting. Kebudayaan Melayu-Islam sejak ratusan tahun telah memperlihatkan kemampuannya untuk berkembang pesat merangkumi bahasa, kesusasteraan, kesenian, pemikiran, dan norma hidup. memang tidak dapat dinafikan bahwa fenomena globalisasi memberikan pengaruh kepada kehidupan umat Melayu-Islam. Namun, pengaruhnya lebih cenderung kepada negatif berbanding positif. Cuma ia bergantung kepada umat Islam untuk mendepaninya dengan berpegang kepada ajaran Islam yang sebenar dengan berpaksikan kepada al-Qur'an dan al-Hadits. Pegangan yang kukuh dan utuh terhadap dua sumber Perundangan ini mampu menyelamatkan umat manusia khususnya umat Islam daripada terjerumus ke dalam kemungkaran yang tjidak dituntut dalam syariat Isla

    I am the melting pot: Multiple identity integration among gay/bisexual/questioning male ethnic minority adolescents

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    For adolescents who belong to multiple minority groups, such as those who are ethnic and sexual minorities, they must develop both their ethnic and sexual identities as they develop their overall identity (Chung & Katayama, 1998). The goal of this study was to examine the ways in which ethnic and sexual minority male adolescents integrate their multiple identities, and to examine how their presentation of their identities changes depending on context. Because of the various types of data collected for each participant, a case study analysis (Yin, 1981) was employed to determine the themes and differences across participants and within each participant. The data that composed each individual participant’s case included the quantitative survey, the qualitative interview, and the Man Drawings. The results indicated that the youth in the study were able to integrate their multiple identities into their larger self-concept in spite of the various barriers to identity integration in all the communities in which they interacted. However, this was not completed without significant effort, as the participants indicated that they were developing their sense of ethnic, sexual, and gender identities at the time of data collection. The results indicated that the youth were able to develop a complex sense of self despite the presence of both positive and negative messages maintained by elements of all the communities of their membership. This process was further complicated because these identities were still under development during the integration process. Despite these challenges, the youth were able to integrate the many parts of themselves into one larger cohesive self-concept. Concerning the presentation of these multiple identities, the youth also engaged in a creative process to avoid the negative elements within their multiple communities by managing the expression of particular identities while participating in various aspects of their communities. The youth were adept in understanding the level of acceptance concerning their identities, and managed their behaviors to either minimize or enhance the visibility of particular aspects of themselves. Similar to the process of identity integration, the ways in which youth presented their identities was unique to the individual and their circumstances

    Effect of Aloe vera on some serum bioactive parameters in male Wistar albino rats

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    For centuries, Aloe vera has been hailed as a natural remedy with a plethora of health benefits. The present study aimed to evaluate the impact of A. vera on their haematological, biochemical, and immunological parameters. Twenty male Wistar albino rats were taken and split into two groups. Group I (Treatment Group)received a prepared aqueous A. vera extract at a concentration of 50 mg/kg of body weight for a full 30 days. Group II (Control Group) was given 0.9% normal saline as a placebo.The study found that the rats that received the A. vera extract had significantly (p<0.05) higher packed cell volume (14.8±1.08) compared to the control group (11.26±0.45). However, there were no significant changes in the levels of hemoglobin (Hb), red blood cell count (RBC),mean corpuscular hemoglobin (MCH) concentration, white blood cells (WBC) count, platelets count, and mean corpuscular volume (MCV). The serum alanine transaminase (ALT) concentration (U/L) was significantly (p<0.05)  lower in the treated group (39.54±7.74) than in the control group (77.68±6.96), while there were no significant changes in the levels of urea and creatinine compared to the control group. The plasma levels of proinflammatory markers(TNFa, IL-6, and IFNγ) showed no significant differences between both groups. Overall, A. vera showed promise as a natural remedy for improving certain aspects of health, but more research is needed to understand its effects fully.

    Global existence and exponential decay for hyperbolic dissipative relativistic fluid theories

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    We consider dissipative relativistic fluid theories on a fixed flat, compact, globally hyperbolic, Lorentzian manifold. We prove that for all initial data in a small enough neighborhood of the equilibrium states (in an appropriate Sobolev norm), the solutions evolve smoothly in time forever and decay exponentially to some, in general undetermined, equilibrium state. To prove this, three conditions are imposed on these theories. The first condition requires the system of equations to be symmetric hyperbolic, a fundamental requisite to have a well posed and physically consistent initial value formulation. The second condition is a generic consequence of the entropy law, and is imposed on the non principal part of the equations. The third condition is imposed on the principal part of the equations and it implies that the dissipation affects all the fields of the theory. With these requirements we prove that all the eigenvalues of the symbol associated to the system of equations of the fluid theory have strictly negative real parts, which in fact, is an alternative characterization for the theory to be totally dissipative. Once this result has been obtained, a straight forward application of a general stability theorem due to Kreiss, Ortiz, and Reula, implies the results above mentioned.Comment: 10 pages, Late
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