8,588 research outputs found

    Measurements of charged-particle distributions with the ATLAS detector

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    Inclusive charged-particle measurements probe the low-energy region of the non-perturbative quantum chromodynamics. The ATLAS collaboration has recently measured the charged-particle multiplicity and its dependence on transverse momentum and pseudorapidity in special data sets with low LHC beam currents, recorded at centre-of-mass energies of 8 TeV and 13 TeV. The measurements at 8 TeV cover a wide spectrum using charged-particle selections with minimum transverse momentum of both 100 MeV and 500 MeV and in various phase space regions of low and high charged-particle multiplicities, some of which are studied for the first time by ATLAS. The measurements at 13 TeV also present detailed studies with a minimum transverse momentum of both 100 MeV and 500 MeV. The measurements are compared with predictions of various tuned Monte Carlo generators and are found to provide strong constraints on these. None of the Monte Carlo generators with their respective tunes are able to reproduce all the features of the data.Comment: Proceedings of Low-x Meeting 201

    Decoding Hidden Markov Models Faster Than Viterbi Via Online Matrix-Vector (max, +)-Multiplication

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    In this paper, we present a novel algorithm for the maximum a posteriori decoding (MAPD) of time-homogeneous Hidden Markov Models (HMM), improving the worst-case running time of the classical Viterbi algorithm by a logarithmic factor. In our approach, we interpret the Viterbi algorithm as a repeated computation of matrix-vector (max,+)(\max, +)-multiplications. On time-homogeneous HMMs, this computation is online: a matrix, known in advance, has to be multiplied with several vectors revealed one at a time. Our main contribution is an algorithm solving this version of matrix-vector (max,+)(\max,+)-multiplication in subquadratic time, by performing a polynomial preprocessing of the matrix. Employing this fast multiplication algorithm, we solve the MAPD problem in O(mn2/logn)O(mn^2/ \log n) time for any time-homogeneous HMM of size nn and observation sequence of length mm, with an extra polynomial preprocessing cost negligible for m>nm > n. To the best of our knowledge, this is the first algorithm for the MAPD problem requiring subquadratic time per observation, under the only assumption -- usually verified in practice -- that the transition probability matrix does not change with time.Comment: AAAI 2016, to appea

    Optimization of indirubin and indigo production in E.coli

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    The goal of this thesis is to determine the conditions that give the highest yield of indigo and indirubin in recombinant E.coli. This E.coli has been transformed with a P450 gene from woad, an indigo producing plant. The conditions investigated were the type of media, the amount of inducer, the presences of supplements, and the induction time. The techniques used during the experiments were liquid-liquid extraction using separatory funnels and centrifugation, rotary evaporation, UV-vis spectrophotometry, and thin layer chromatography. Thin layer chromatography showed that the products of the reaction are indigo and indirubin; UV-vis spectrophotometry was used to find the absorbance at different wavelengths, which were used to calculate the concentration of indigo and indirubin in each sample, and determine the conditions that gave the highest yield. These conditions were found to be TB for the medium, 40 µL of IPTG, the presence of supplements, and 96 hours for the induction time

    Effects of Nostalgia on Responses to Negative Feedback

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    Nostalgia is a bittersweet emotion evoked by memories of cherished personal experiences. Though nostalgia is a self-focused emotion, it has many interpersonal effects as well. Feeling nostalgia increases feelings of social connectedness and self esteem, and may protect against negative effects of existential threat (Wildschut et al., 2006). However, less is known about the extent to which nostalgia relates to anger and aggression. We hypothesized that nostalgia would buffer against the effect of negative feedback on feelings of anger and motivation to aggress. Undergraduate students wrote about a nostalgic or objective memory, and then received negative feedback about another personal writing project. Participants reported their feelings of anger, then had the opportunity to punish the individual who gave them negative feedback by administering loud noise blasts in a competitive game. We discuss the results and real-world implications of these findings.https://scholarscompass.vcu.edu/uresposters/1283/thumbnail.jp

    How Charts Lie: What You Design Is Not What People See

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    Visualizations such as charts, maps and infographics are ubiquitous nowadays. They are useful because they can reveal patterns and trends in data. Good visualizations make us smarter - if we know how to read them. However, visualizations can also deceive us by displaying incomplete or inaccurate data, suggesting misleading patterns, and concealing uncertainty. They are also frequently misunderstood. Many of us are ill-equipped to interpret the visuals that politicians, journalists, advertisers and even our employers present each day. We are in need of expanding the notion of literacy to include numeracy (numerical literacy) and graphicacy (graphical literacy)

    HEBI SANI: MENTAL WELL BEING AMONG THE WORKING CLASS AFRO-SURINAMESE IN PARAMARIBO, SURINAME

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    This dissertation describes the results of a two year anthropological investigation into the concept of mental well being among the working class Afro-Surinamese population in Paramaribo, Suriname. More specifically, the research investigated how working class Afro-Surinamese in Paramaribo, Suriname define and maintain their sense of mental well-being, given their unique ethnic identity within a multi-ethnic and multicultural society, and given that their environment is heavily compromised by negative globalizing forces Over the course of two years a total of 62 people contributed information through group and individual interviews, which was supplemented by information obtained through participant observation. Findings show a highly complex system of mental well being that consists of a number of interlocking and interdependent factors, which, when kept in a harmonious relationship with each other, are presumed to bring mental well being. There are unique Afro-Surinamese measures available for strengthening mental well being based in rich and historical cultural traditions that are currently under-utilized, but have the potential to be revived and introduced for the benefit of peoples mental well being. Suriname was selected as a Caribbean country that struggles in a marginalized political and economic position in regards to the rest of the Caribbean, and in relation to the world powers. Suriname is also a Dutch Caribbean country about which little academic information has been published. This research aimed to bring forth a story of a globally marginalized people, and particularly of a population of African descent. It aimed to bring attention to the concept of mental well being among African Diaspora people, and to use the story of a small population as a starting point to connect with and look at other populations, Diaspora based or otherwise. Theoretical viewpoints of African Diaspora, Globalization, and a combination of Black Feminist/Third World Feminist/Caribbean Feminist theories were used to guide and shape this research. Lastly, an attempt was made to introduce the concept of Spirituality as a new and complementary aspect of ethnographic methodology

    Atmospheric Thermodynamics

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    Studies in SEOP Hyperpolarized 3He: Measuring Ko and the Spatial Dependence of Alkali Polarization

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    3He is an isotope of helium whose nucleus is composed of two protons and one neutron. The proportion of atoms whose spins are pointed along the same direction in a volume of 3He gas is known as the polarization. This study entails two experiments in the field of 3He polarimetry concerned with measuring the polarization of a 3He cell and reducing the uncertainty associated with it. 3He cells are full of gaseous 3He, along with alkali metal vapors, K and Rb in our case. The polarization of a 3He cell can be measured using an electron paramagnetic resonance (EPR) frequency shift. The EPR frequency is related to the 3He polarization through a constant, Ko. The first experiment in this study involves isolating Ko by varying the geometry of the magnetic field generated by the polarized 3He. The spatial dependence of the polarization is also of interest. To measure this, we use Faraday rotation. For a 3He cell, the amount of rotation is determined by the polarization of the alkali gas. The second experiment in the study involves inferring the polarization of a path through a cell using Faraday rotation measurements. This will establish a spatial mapping of polarization in the cell that will help improve our understanding of its overall polarization
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