21,222 research outputs found

    Precision Flavour Physics and Supersymmetry

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    We review the salient features of a comparative study of the profile of the CKM unitarity triangle, and the resulting CP-violating phases α\alpha, ÎČ\beta and Îł\gamma in B decays, in the standard model and in several variants of the minimal supersymmetric standard model (MSSM), reported recently by us. These theories are characterized by a single phase in the quark flavour mixing matrix and give rise to well-defined contributions in the flavour-changing-neutral-current transitions in K and B decays. We analyse the supersymmetric contributions to the mass differences in the Bd-Bd(bar) and Bs-Bs(bar) systems, ΔMd\Delta M_d and ΔMs\Delta M_s, respectively, and to the CP-violating quantity ∣epsilon∣|epsilon| in K decays. Our analysis shows that the predicted ranges of ÎČ\beta in the standard model and in MSSM models are very similar. However, precise measurements at B-factories and hadron machines may be able to distinguish these theories in terms of the other two CP-violating phases α\alpha and Îł\gamma. (Contribution to the Festschrift for L.B. Okun, to appear in a special issue of Physics Reports, eds. V.L. Telegdi and K. Winter)Comment: 35 pages, 12 figure

    Temporal and spatial combining for 5G mmWave small cells

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    This chapter proposes the combination of temporal processing through Rake combining based on direct sequence-spread spectrum (DS-SS), and multiple antenna beamforming or antenna spatial diversity as a possible physical layer access technique for fifth generation (5G) small cell base stations (SBS) operating in the millimetre wave (mmWave) frequencies. Unlike earlier works in the literature aimed at previous generation wireless, the use of the beamforming is presented as operating in the radio frequency (RF) domain, rather than the baseband domain, to minimise power expenditure as a more suitable method for 5G small cells. Some potential limitations associated with massive multiple input-multiple output (MIMO) for small cells are discussed relating to the likely limitation on available antennas and resultant beamwidth. Rather than relying, solely, on expensive and potentially power hungry massive MIMO (which in the case of a SBS for indoor use will be limited by a physically small form factor) the use of a limited number of antennas, complimented with Rake combining, or antenna diversity is given consideration for short distance indoor communications for both the SBS) and user equipment (UE). The proposal’s aim is twofold: to solve eroded path loss due to the effective antenna aperture reduction and to satisfy sensitivity to blockages and multipath dispersion in indoor, small coverage area base stations. Two candidate architectures are proposed. With higher data rates, more rigorous analysis of circuit power and its effect on energy efficiency (EE) is provided. A detailed investigation is provided into the likely design and signal processing requirements. Finally, the proposed architectures are compared to current fourth generation long term evolution (LTE) MIMO technologies for their anticipated power consumption and EE

    The New Zealand Construction Contracts Amendment Act 2015 - For Better or Worse?

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    Adjudication has been statutorily introduced as an alternative dispute resolution method in 14 jurisdictions including New Zealand. Whilst adjudication under the New Zealand Construction Contracts Act 2002 has been hailed a success, further refinements were proposed in the Construction Contracts Amendment Bill first published in 2013. As part of the legislative process, 48 submissions were made to the Commerce Committee. There was general support for most of the amendments, but some parties expressed concerns on some of the changes. A documentary analysis of the Amendment Bills and submissions to the Commerce Committee was made to critically evaluate the changes proposed and establish if they were improvements. The findings show the major changes proposed include (i) removing most of the distinctions between the treatment of residential and commercial contracts under the Act, (ii) extending the scope of the Act to apply to contracts for certain professional services, (iii) removing the distinction between enforcement of payment determinations and of those relating to rights and obligations, and (iv) making the enforcement process more efficient. The findings also show that during a period of over two years from when the Bill was first introduced in January 2013, one other significant improvement for retentions to be held in trust was made. A few proposals to further refine the Bill such as the suggestion to mandate retentions to be kepts in a separate trust account were however not accepted. The Construction Contract Amendment Bill (Bill 97-3) was uninanimously passed during the third and final reading in Parliament on 20 October 2015 with most of the amendments coming into force on 1 December 2015, those incorporating professional services on 1 September 2016, and the retention provisions on 31 March 2017. Royal assent was given on 11 October 2015 leading to the enactment of the Construction Contracts Amendment Act 2015

    Chitin-Induced Airway Epithelial Cell Innate Immune Responses Are Inhibited by Carvacrol/Thymol.

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    Chitin is produced in large amounts by fungi, insects, and other organisms and has been implicated in the pathogenesis of asthma. Airway epithelial cells are in direct contact with environmental particles and serve as the first line of defense against inhaled allergens and pathogens. The potential contributions of airway epithelial cells to chitin-induced asthma remain poorly understood. We hypothesized that chitin directly stimulates airway epithelial cells to release cytokines that promote type 2 immune responses and to induce expression of molecules which are important in innate immune responses. We found that chitin exposure rapidly induced the expression of three key type 2-promoting cytokines, IL-25, IL-33 and TSLP, in BEAS-2B transformed human bronchial epithelial cells and in A549 and H292 lung carcinoma cells. Chitin also induced the expression of the key pattern recognition receptors TLR2 and TLR4. Chitin induced the expression of miR-155, miR-146a and miR-21, each of which is known to up-regulate the expression of pro-inflammatory cytokines. Also the expression of SOCS1 and SHIP1 which are known targets of miR-155 was repressed by chitin treatment. The monoterpene phenol carvacrol (Car) and its isomer thymol (Thy) are found in herbal essential oils and have been shown to inhibit allergic inflammation in asthma models. We found that Car/Thy inhibited the effects of chitin on type 2-promoting cytokine release and on the expression of TLRs, SOCS1, SHIP1, and miRNAs. Car/Thy could also efficiently reduce the protein levels of TLR4, inhibit the increase in TLR2 protein levels in chitin plus Car/Thy-treated cells and increase the protein levels of SHIP1 and SOCS1, which are negative regulators of TLR-mediated inflammatory responses. We conclude that direct effects of chitin on airway epithelial cells are likely to contribute to allergic airway diseases like asthma, and that Car/Thy directly inhibits epithelial cell pro-inflammatory responses to chitin

    A study of project planning on Libyan construction projects

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    Construction projects are regularly faced by scheduling problems causing the projects to finish beyond their predetermined due date; this is a global phenomenon. The main purpose of this study is to consider the problems associated with project planning generally, with specific reference to construction projects in Libya. This study is unique in two respects. First, despite the recent high volume of infrastructure work in the country, there have been few investigations into construction delays in Libya. Secondly, earlier studies have considered the causes or the effects of project delays, whereas the present aim is to evaluate the potential of applying a planning and scheduling technique that is entirely novel in the Libyan context. The paper reports the results of Phase I of this research

    Social music in cars

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    This paper builds an understanding of how music is currently experienced by a social group travelling together in a car - how songs are chosen for playing, how music both reflects and influences the group’s mood and social interaction, who supplies the music, the hardware/software that supports song selection and presentation. This fine-grained context emerges from a qualitative analysis of a rich set of ethnographic data (participant observations and interviews) focusing primarily on the experience of in-car music on moderate length and long trips. We suggest features and functionality for music software to enhance the social experience when travelling in cars, and prototype and test a user interface based on design suggestions drawn from the data
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