192,595 research outputs found

    Fast Exact Algorithms Using Hadamard Product of Polynomials

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    Let C be an arithmetic circuit of poly(n) size given as input that computes a polynomial f in F[X], where X={x_1,x_2,...,x_n} and F is any field where the field arithmetic can be performed efficiently. We obtain new algorithms for the following two problems first studied by Koutis and Williams [Ioannis Koutis, 2008; Ryan Williams, 2009; Ioannis Koutis and Ryan Williams, 2016]. - (k,n)-MLC: Compute the sum of the coefficients of all degree-k multilinear monomials in the polynomial f. - k-MMD: Test if there is a nonzero degree-k multilinear monomial in the polynomial f. Our algorithms are based on the fact that the Hadamard product f o S_{n,k}, is the degree-k multilinear part of f, where S_{n,k} is the k^{th} elementary symmetric polynomial. - For (k,n)-MLC problem, we give a deterministic algorithm of run time O^*(n^(k/2+c log k)) (where c is a constant), answering an open question of Koutis and Williams [Ioannis Koutis and Ryan Williams, 2016]. As corollaries, we show O^*(binom{n}{downarrow k/2})-time exact counting algorithms for several combinatorial problems: k-Tree, t-Dominating Set, m-Dimensional k-Matching. - For k-MMD problem, we give a randomized algorithm of run time 4.32^k * poly(n,k). Our algorithm uses only poly(n,k) space. This matches the run time of a recent algorithm [Cornelius Brand et al., 2018] for k-MMD which requires exponential (in k) space. Other results include fast deterministic algorithms for (k,n)-MLC and k-MMD problems for depth three circuits

    Transfected poly(I:C) activates different dsRNA receptors leading to apoptosis or immunoadjuvant response in androgen-independent prostate cancer cells

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    Background: Castration-resistant prostate cancer (CRPC) is refractory to chemo-radiotherapy. Results: Transfection of the synthetic analog of dsRNA poly(I:C) simultaneously stimulates apoptosis and IFN- expression through different pathways in androgen-independent prostate cancer (PCa) cells. Conclusion: Dual parallel pathways triggered by distinct receptors activate direct and immunologically mediated antitumor effects in advanced PCa. Significance: The proapoptotic/immunoadjuvant poly(I:C)-Lipofectamine complex may offer new therapeutic insights into CRPC

    Exchangeable Variable Models

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    A sequence of random variables is exchangeable if its joint distribution is invariant under variable permutations. We introduce exchangeable variable models (EVMs) as a novel class of probabilistic models whose basic building blocks are partially exchangeable sequences, a generalization of exchangeable sequences. We prove that a family of tractable EVMs is optimal under zero-one loss for a large class of functions, including parity and threshold functions, and strictly subsumes existing tractable independence-based model families. Extensive experiments show that EVMs outperform state of the art classifiers such as SVMs and probabilistic models which are solely based on independence assumptions.Comment: ICML 201

    Noise-Resilient Group Testing with Order-Optimal Tests and Fast-and-Reliable Decoding

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    Group testing (GT) is the Boolean counterpart of compressed sensing and the marketplace of new ideas for related problems such as cognitive radio and heavy hitter. A GT scheme is considered good if it is nonadaptive, uses O(klogn)O(k \log n) tests, resists noise, can be decoded in O(kpoly(logn))O(k \operatorname{poly}(\log n)) time, and makes nearly no mistakes. In this paper, we propose "Gacha GT", an elementary, self-contained, and unified randomized scheme that, for the first time, satisfies all criteria for a fairly large region of parameters, namely when logk<log(n)11/O(1)\log k < \log(n)^{1-1/O(1)}. Outside this parameter region, Gacha can be specialized to outperform the state-of-the-art partial-recovery GTs, exact-recovery GTs, and worst-case GTs. The new idea that runs through this paper, using an analogy, is to ask every person to break her 99-digit "phone number" into three 33-digit numbers xx, yy, and zz and write (b,x)(b, x), (b,y)(b, y), and (b,z)(b, z) on three pieces of sticky notes, where bb is her "birthday". This way, one can sort the sticky notes by birthday to reassemble the phone numbers. This birthday--number code and other coded constructions can be stacked like a multipartite graph pyramid. Gacha's encoder will synthesize the test results from the bottom up; and Gacha's decoder will reassemble the phone numbers from the top down.Comment: 23 pages, 8 figure
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