4,950 research outputs found

    Dipole-interacting Fermionic Dark Matter in positron, antiproton, and gamma-ray channels

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    Cosmic ray signals from dipole-interacting dark matter annihilation are considered in the positron, antiproton and photon channels. The predicted signals in the positron channel could nicely account for the excess of positron fraction from Fermi LAT, PAMELA, HEAT and AMS-01 experiments for the dark matter mass larger than 100 GeV with a boost (enhancement) factor of 30-80. No excess of antiproton over proton ratio at the experiments also gives a severe restriction for this scenario. With the boost factors, the predicted signals from Galactic halo and signals as mono-energetic gamma-ray lines (monochromatic photons) for the region close to the Galactic center are investigated. The gamma-ray excess of recent tentative analyses based on Fermi LAT data and the potential probe of the monochromatic lines at a planned experiment, AMS-02, are also considered.Comment: Version to be published in PRD(2013), Title changed, text modifie

    Comparison of Post Hoc Multiple Pairwise Testing Procedures as Applied to Small k-Group Logrank Tests

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    Abstract: The logrank test is widely used to compare groups on distribution of survival time in the presence of censoring. There is no convention for post hoc pairwise comparisons after a significant omnibus k-group logrank test. This simulation study compares four post hoc pairwise testing procedures: Bonferroni, Dunn-Šidák, Hochberg, and unadjusted post hoc logrank test procedure. Evaluation criteria include, familywise type I error rate, correct decision rate, number of correctly rejected pairs, and false discovery rate. We demonstrated that when conditioned upon rejection of the omnibus test, multiplicity adjustments may be unnecessary and can be overly conservative when k is at most 4, or number of comparisons is no greater than 6. This is supported by the results that the performance of the unadjusted post hoc logrank test procedure is preferred over the others on all criteria except for the false discovery rate. The Hochberg procedure appears to be superior among the adjustments examined. Data from a clinical trial for suicide prevention illustrate these approaches where number of comparison groups is often limited

    The first report of Lasioderma Serricorne infestation on dried fish crackers in Malaysia

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    This paper is the first record of cigarette beetles collected from dried fish crackers (also known as “keropok ikan” in Malay) in Malaysia. The dead cigarette beetles were firstly isolated from a packet of dried fish crackers and were subsequently kept in 70% ethanol. The beetles were then identified as Lasioderma serricorne (Fabricius 1792) (Coleoptera: Anobiidae). They are common pests of stored products such as tobacco, flour, and cocoa beans but there is no record of this beetle infestation on dried fish crackers in Malaysia

    Bioactive composites for bone tissue engineering

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    One of the major challenges of bone tissue engineering is the production of a suitable scaffold material. In this review the current composite materials options available are considered covering both the methods of both production and assessing the scaffolds. A range of production routes have been investigated ranging from the use of porogens to produce the porosity through to controlled deposition methods. The testing regimes have included mechanical testing of the materials produced through to in vivo testing of the scaffolds. While the ideal scaffold material has not yet been produced, progress is being made

    Artificial Intelligence (AI)-Based Technology Adoption in the Construction Industry: A Cross National Perspective Using the Technology Acceptance Model

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    The research has chosen the workers in construction-related companies in South Korea and the United Kingdom (UK) as research subjects in order to analyse factors that influence their usage intention of Artificial Intelligence (AI) based technologies. The perceived usefulness had a positive impact (+) on technological satisfaction and usage intention in terms of the commonalities shown by the construction industry workers in both countries, South Korea and the UK, in adopting AI-based technologies. Moreover, the most remarkable differences were personal competence and social influence when choosing AI-based technologies. It was analysed that in the case of South Korea, personal competence had a positive impact (+) on perceived ease of use, whereas the UK had a positive impact (+) on perceived usefulness and perceived ease of use. This study holds particular significance in the domain of cross-cultural research within the construction industry. It conducts an analysis of the factors influencing the adoption of AI-driven technologies or products, with a specific focus on the cultural differences between two nations: South Korea and the UK, which represent Eastern and Western cultural paradigms, respectively

    Human and Animal Pentastomiasis in Malaysia : Review

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    Pentastomiasis is a zoonotic parasitic disease induced by the larval stages of pentasomes. The disease has been reported in Africa, the Middle East and Southeast Asia and caused by the nymphs of the two genera: Linguatula and Armillifer and the two species L. serrata and A. armillatus regard for more than 90% of human cases. The definitive hosts of Armillifer spp. are snakes, lizards and other reptiles. The parasites live in the upper respiratory tracts and lay eggs that are passed out through respiratory secretions, saliva or faeces. Intermediate hosts are humans, rodents and other mammals. Humans incidentally acquire the infestation by the consumption of uncooked infested snake meat or by drinking water contaminated with ova of the pentastomes. In the intestinal tract, the larvae hatch from the ova, penetrate the intestinal wall and migrate to organs in which the liver is the most common site. Human pentastomiasis was reported among aborigines in West and East Malaysia. Armillifer moniliformis was identified in wild animals and carnivores with infection rate 1.8% and 20.7% respectively. The adults of pentostomes (A. moniliformis) were recovered from two out of six snakes Python reticulates. Recently a case of human pentastomiasis was reported in Sabah, East Malaysia, caused by nymph of Armillifer moniliformis

    Spontaneous Symmetry Breaking of Population between Two Dynamic Attractors in a Driven Atomic Trap: Ising-class Phase Transition

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    We have observed spontaneous symmetry breaking of atomic populations in the dynamic phase-space double-potential system, which is produced in the parametrically driven magneto-optical trap of atoms. We find that the system exhibits similar characteristics of the Ising-class phase transition and the critical value of the control parameter, which is the total atomic number, can be calculated. In particular, the collective effect of the laser shadow becomes dominant at large atomic number, which is responsible for the population asymmetry of the dynamic two-state system. This study may be useful for investigation of dynamic phase transition and temporal behaviour of critical phenomena.Comment: 4 pages, 4 figure
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