Culture on trust within organizations between China and the UK

This research paper looks into the social aspect of the topic "Trust" in between the Chinese and British construction industry. It will also see how culture affects trust in the relationships between management levels within contracting organisations. Many theories by other scholars have looked upon and developed on further. The research consists of analysis of questionnaires filled out by different management levels in many organisations between China and the UK, and are presented in graphs and tables of data

Creation of a multiple-use recombinant inbred line population for the development of molecular markers in soft white winter wheat

Tese de doutoramento em Física (Pré-Bolonha), especialidade de Física Experimental, apresentada à Faculdade de Ciências e Tecnologia da Universidade de CoimbraPositron emission tomography based on resistive plate chambers (RPC-PET) has been proposed for both preclinical and clinical applications. We firstly present imaging results of needle-like and planar 22Na sources obtained with a prototype of a high-acceptance small-animal RPC-PET. The two detector modules utilized in this experiment had an effective front face of 6.4 x 6.4 cm^2 and consisted of 5 gas gaps and 6 glass electrodes with a total thickness of 5 mm. The data included lines of response (LORs) inclined up to 58º, and the depth of interaction (DOI) was accurately measured, demonstrating the parallax-free property inherent to RPC-PET. The maximum likelihood expectation-maximization (MLEM) reconstruction of the acquired data yielded an excellent and stable resolution of 0.4 mm full width at half maximum (FWHM). Concurrently, we pursued studies of a suggested whole-body single-bed RPC-PET. It has been shown by simulation that RPC-PET with an axial field-of-view (AFOV) of 2.4 m is feasible and yields an absolute sensitivity at least one order of magnitude superior to that of typical crystal-based PET scanners. In addition, RPC-PET offers an important time-of-flight (TOF) advantage and provides a potentially very-high spatial resolution at the detector level. In the second part of this work, a fully three-dimensional reconstruction algorithm capable of processing the very inclined LORs from large AFOV systems such as RPC-PET is demonstrated. It relies on the application of a TOF-based-kernel into the MLEM algorithm. With the 300 ps FWHM time resolution, already experimentally demonstrated, a rejection of 63% of the body-scattered events is obtained. We present reconstructed results from blind simulations corresponding to the anthropomorphic phantom, NCAT, with oncological lesions introduced into different locations within the human body. A comparison between 300 and 600 ps FWHM TOF reconstructed images is performed, with an increasing detectability being observed for a better TOF resolution. We finally compare issues related to image convergence speed. An alternative new approach, which consists in dividing the full-body data into nine different image regions that are reconstructed independently with graphical processing unit (GPU) assistance, provides a six times faster reconstruction compared with a GPU-based whole-body reconstruction. For a 300 ps FWHM RPC-PET scanner, this allows reaching a reconstructed image, that results from 1.6 x 10^10 annihilations within 7 minutes and upon injection of 2 mCi, just 4 minutes after the end of data acquisition. We conclude that RPC-PET is well oriented to compete with other commercial PET scanners in the global market.A tomografia por emissão de positrões baseada em detectores do tipo câmaras de placas resistivas (RPC-PET) foi proposta para aplicação em ensaios com pequenos animais e na prática clínica. Neste trabalho, apresentamos primeiramente resultados experimentais obtidos a partir de um protótipo RPC-PET de alta aceitação para pequenos animais. Foram obtidas imagens de fontes do radioisótopo 22Na, uma quase pontual e outra planar. Usámos dois módulos de detectores RPC com uma área activa de 6.4 x 6.4 cm^2 e uma espessura de 5 mm, constituída por 6 vidros empilhados e 5 espaços gasosos definidos entre eles. Os dados adquiridos incluíram linhas de coincidência (LORs) inclinadas até um ângulo de 58º, tornando essencial a medida precisa da profundidade de interacção. A identificação dos espaços gasosos onde ocorreram as avalanches permitiu demonstrar a ausência de erro de paralaxe nas medidas realizadas com o RPC-PET para pequenos animais. A partir da reconstrução dos dados processados com o algoritmo maximum likelihood expectation-maximization (MLEM), obtivemos uma resolução espacial com largura a meia altura (FWHM) de 0.4 mm, excelente e estável. Em paralelo, continuámos a estudar as potencialidades de um protótipo RPC-PET de corpo inteiro e cama única, orientado para pessoas. Já foi anteriormente demonstrado por simulação que um scanner RPC-PET com 2.4 m de campo de visão axial (AFOV) é viável e permitirá o aumento de sensibilidade de pelo menos uma ordem de grandeza em relação aos scanners PET com cristais. Duas outras virtudes do RPC-PET são a sua capacidade de medição do tempo de voo (TOF) dos fotões e a elevada resolução espacial ao nível do detector. Na segunda parte deste trabalho apresentamos um algoritmo de reconstrução, totalmente tridimensional, capaz de processar LORs muito inclinadas em sistemas com um AFOV longo, como é o caso do RPC-PET. Este algoritmo acrescenta um kernel ao algoritmo MLEM, baseado na informação de TOF. Com uma resolução temporal de 300 ps FWHM, já experimentalmente comprovada, é possível rejeitar 63% dos eventos dispersados no corpo humano. Exibimos imagens reconstruídas obtidas a partir de simulações do fantoma antropomórfico, NCAT, com lesões oncológicas situadas em diferentes locais do corpo humano. A comparação entre imagens conseguidas com resoluções temporais de 300 ps e 600 ps FWHM, permite observar uma detectabilidade acrescida associada à melhor resolução de TOF. Por último, são estudados os tempos de convergência da reconstrução. Um método inovador e alternativo, que consiste na divisão dos dados do corpo humano em nove regiões e na reconstrução independente desses dados com recurso a unidades de processamento gráfico (GPUs), permite uma reconstrução seis vezes mais rápida do que a reconstrução de corpo inteiro também com o auxílio de GPUs. A partir de dados de 1.6 x 10^10 aniquilações ocorridas durante uma aquisição de 7 minutos e para uma actividade injectada de 2 mCi, um scanner RPC-PET com uma resolução temporal de 300 ps FWHM permitirá obter uma imagem reconstruída apenas 4 minutos após o fim da aquisição. Podemos assim concluir que o RPC-PET está bem colocado para competir no mercado dos scanners PET comerciais

Efficient public-key cryptography with bounded leakage and tamper resilience

We revisit the question of constructing public-key encryption and signature schemes with security in the presence of bounded leakage and tampering memory attacks. For signatures we obtain the first construction in the standard model; for public-key encryption we obtain the first construction free of pairing (avoiding non-interactive zero-knowledge proofs). Our constructions are based on generic building blocks, and, as we show, also admit efficient instantiations under fairly standard number-theoretic assumptions. The model of bounded tamper resistance was recently put forward by Damgård et al. (Asiacrypt 2013) as an attractive path to achieve security against arbitrary memory tampering attacks without making hardware assumptions (such as the existence of a protected self-destruct or key-update mechanism), the only restriction being on the number of allowed tampering attempts (which is a parameter of the scheme). This allows to circumvent known impossibility results for unrestricted tampering (Gennaro et al., TCC 2010), while still being able to capture realistic tampering attack

An Efficient Large-Area Grating Coupler for Surface Plasmon Polaritons

We report the design, fabrication and characterization of a periodic grating of shallow rectangular grooves in a metallic film with the goal of maximizing the coupling efficiency of an extended plane wave (PW) of visible or near-infrared light into a single surface plasmon polariton (SPP) mode on a flat metal surface. A PW-to-SPP power conversion factor > 45 % is demonstrated at a wavelength of 780 nm, which exceeds by an order of magnitude the experimental performance of SPP grating couplers reported to date at any wavelength. Conversion efficiency is maximized by matching the dissipative SPP losses along the grating surface to the local coupling strength. This critical coupling condition is experimentally achieved by tailoring the groove depth and width using a focused ion beam.Comment: The final publication is available at http://www.springerlink.com. http://dx.doi.org/10.1007/s11468-011-9303-

A Tunable Two-impurity Kondo system in an atomic point contact

Two magnetic atoms, one attached to the tip of a Scanning Tunneling Microscope (STM) and one adsorbed on a metal surface, each constituting a Kondo system, have been proposed as one of the simplest conceivable systems potentially exhibiting quantum critical behaviour. We have succeeded in implementing this concept experimentally for cobalt dimers clamped between an STM tip and a gold surface. Control of the tip-sample distance with sub-picometer resolution allows us to tune the interaction between the two cobalt atoms with unprecedented precision. Electronic transport measurements on this two-impurity Kondo system reveal a rich physical scenario which is governed by a crossover from local Kondo screening to non-local singlet formation due to antiferromagnetic coupling as a function of separation of the cobalt atoms.Comment: 22 pages, 5 figure

The Near-Sun Streamer Belt Solar Wind: Turbulence and Solar Wind Acceleration

The fourth orbit of Parker Solar Probe (PSP) reached heliocentric distances down to 27.9 Rs, allowing solar wind turbulence and acceleration mechanisms to be studied in situ closer to the Sun than previously possible. The turbulence properties were found to be significantly different in the inbound and outbound portions of PSP's fourth solar encounter, likely due to the proximity to the heliospheric current sheet (HCS) in the outbound period. Near the HCS, in the streamer belt wind, the turbulence was found to have lower amplitudes, higher magnetic compressibility, a steeper magnetic field spectrum (with spectral index close to -5/3 rather than -3/2), a lower Alfv\'enicity, and a "1/f" break at much lower frequencies. These are also features of slow wind at 1 au, suggesting the near-Sun streamer belt wind to be the prototypical slow solar wind. The transition in properties occurs at a predicted angular distance of ~4{\deg} from the HCS, suggesting ~8{\deg} as the full-width of the streamer belt wind at these distances. While the majority of the Alfv\'enic turbulence energy fluxes measured by PSP are consistent with those required for reflection-driven turbulence models of solar wind acceleration, the fluxes in the streamer belt are significantly lower than the model predictions, suggesting that additional mechanisms are necessary to explain the acceleration of the streamer belt solar wind

Bˉ→Xsγ\bar{B}\to X_s \gamma in the Two Higgs Doublet Model up to Next-to-Next-to-Leading Order in QCD

We compute three-loop matching corrections to the Wilson coefficients $C_7$ and $C_8$ in the Two Higgs Doublet Model by applying expansions for small, intermediate and large charged Higgs boson masses. The results are used to evaluate the branching ratio of $\bar{B}\to X_s \gamma$ to next-to-next-to leading order accuracy, and to determine an updated lower limit on the charged Higgs boson mass. We find \mhplus \ge 380 GeV at 95% confidence level when the recently completed BABAR data analysis is taken into account. Our results for the charged Higgs contribution to the branching ratio exhibit considerably weaker sensitivity to the matching scale $\mu_0$, as compared to previous calculations.Comment: 20 pages, 15 figures; v2: minor modifications, matches published version in JHE

Automatic analysis of bronchus-artery dimensions to diagnose and monitor airways disease in cystic fibrosis

Background:Cystic fibrosis (CF) lung disease is characterised by progressive airway wall thickening and widening. We aimed to validate an artificial intelligence-based algorithm to assess dimensions of all visible bronchus-artery (BA) pairs on chest CT scans from patients with CF.Methods:The algorithm fully automatically segments the bronchial tree; identifies bronchial generations; matches bronchi with the adjacent arteries; measures for each BA-pair bronchial outer diameter (Bout), bronchial lumen diameter (Bin), bronchial wall thickness (Bwt) and adjacent artery diameter (A); and computes Bout/A, Bin/A and Bwt/A for each BA pair from the segmental bronchi to the last visible generation. Three datasets were used to validate the automatic BA analysis. First BA analysis was executed on 23 manually annotated CT scans (11 CF, 12 control subjects) to compare automatic with manual BA-analysis outcomes. Furthermore, the BA analysis was executed on two longitudinal datasets (Copenhagen 111 CTs, ataluren 347 CTs) to assess longitudinal BA changes and compare them with manual scoring results.Results:The automatic and manual BA analysis showed no significant differences in quantifying bronchi. For the longitudinal datasets the automatic BA analysis detected 247 and 347 BA pairs/CT in the Copenhagen and ataluren dataset, respectively. A significant increase of 0.02 of Bout/A and Bin/A was detected for Copenhagen dataset over an interval of 2 years, and 0.03 of Bout/A and 0.02 of Bin/A for ataluren dataset over an interval of 48 weeks (all p<0.001). The progression of 0.01 of Bwt/A was detected only in the ataluren dataset (p<0.001). BA-analysis outcomes showed weak to strong correlations (correlation coefficient from 0.29 to 0.84) with manual scoring results for airway disease.Conclusion:The BA analysis can fully automatically analyse a large number of BA pairs on chest CTs to detect and monitor progression of bronchial wall thickening and bronchial widening in patients with CF