Universal simulation of Hamiltonian dynamics for qudits

What interactions are sufficient to simulate arbitrary quantum dynamics in a composite quantum system? Dodd et al. (quant-ph/0106064) provided a partial solution to this problem in the form of an efficient algorithm to simulate any desired two-body Hamiltonian evolution using any fixed two-body entangling N-qubit Hamiltonian, and local unitaries. We extend this result to the case where the component systems have D dimensions. As a consequence we explain how universal quantum computation can be performed with any fixed two-body entangling N-qudit Hamiltonian, and local unitaries.Comment: 13 pages, an error in the "Pauli-Euclid-Gottesman Lemma" fixed, main results unchange

Number and Amplitude of Limit Cycles emerging from {\it Topologically Equivalent} Perturbed Centers

We consider three examples of weekly perturbed centers which do not have {\it geometrical equivalence}: a linear center, a degenerate center and a non-hamiltonian center. In each case the number and amplitude of the limit cycles emerging from the period annulus are calculated following the same strategy: we reduce of all of them to locally equivalent perturbed integrable systems of the form: $dH(x,y)+\epsilon(f(x,y)dy-g(x,y)dx)=0$, with $H(x,y)={1/2}(x^2+y^2)$. This reduction allows us to find the Melnikov function, $M(h)=\int_{H=h}fdy-gdx$, associated to each particular problem. We obtain the information on the bifurcation curves of the limit cycles by solving explicitly the equation $M(h)=0$ in each case.Comment: 17 pages, 0 figure

The impact of age, gender and severity of overactive bladder wet on quality of life, productivity, treatment patterns and satisfaction

Objective: The objective of this article is to determine the impact of idiopathic overactive bladder wet (OAB wet) severity, age and gender on health-related quality of life (HRQoL), productivity, treatment patterns and treatment satisfaction. Materials and methods: A prospective, cross-sectional online survey of adults in the United Kingdom was performed to screen for self-reported symptoms of OAB wet. Respondents completed the King’s Health Questionnaire or the Incontinence Quality of Life, as well as the Euroqol 5D, and the Work Productivity and Activity Impairment Specific Health Problem questionnaire, and questions pertaining to distress, treatment and treatment satisfaction. Results: A total of 249 of 1126 respondents (22.1%) met the criteria for OAB wet. Respondents with moderate/severe OAB wet and all women experienced significantly worse HRQoL and work productivity than those with mild symptoms and all men, respectively. Among all OAB wet responders, 62.7% were receiving treatment for their condition, predominantly pads (40.2%); only 1.6% were receiving specialised treatment. Nearly one-half (44.6%) were somewhat or completely dissatisfied with their current treatment. Conclusion: In individuals with OAB wet, severity and gender negatively impact HRQoL and work productivity. A substantial proportion of OAB wet individuals were untreated, and low treatment satisfaction was reported in those receiving treatment. Treatment was generally conservative

Adaptation of Left Ventricular Twist Mechanics in Exercise-Trained Children Is Only Evident after the Adolescent Growth Spurt.

The extent of structural cardiac remodeling in response to endurance training is maturity dependent. In adults, this structural adaptation is often associated with the adaptation of left ventricular (LV) twist mechanics. For example, an increase in LV twist often follows an expansion in end-diastolic volume, whereas a reduction in twist may follow a thickening of the LV walls. While structural cardiac remodeling has been shown to be more prominent post-peak height velocity (PHV), it remains to be determined how this maturation-dependent structural remodeling influences LV twist. Therefore, we aimed to (1) compare LV twist mechanics between trained and untrained children pre- and post-PHV and (2) investigate how LV structural variables relate to LV twist mechanics pre- and post-PHV. Left ventricular function and morphology were assessed (echocardiography) in endurance-trained and untrained boys (n = 38 and n = 28, respectively) and girls (n = 39 and n = 34, respectively). Participants were categorized as either pre- or post-PHV using maturity offset to estimate somatic maturation. Pre-PHV, there were no differences in LV twist or torsion between trained and untrained boys (twist: P = .630; torsion: P = .382) or girls (twist: P = .502; torsion: P = .316), and LV twist mechanics were not related with any LV structural variables (P > .05). Post-PHV, LV twist was lower in trained versus untrained boys (P = .004), with torsion lower in trained groups, irrespective of sex (boys: P < .001; girls: P = .017). Moreover, LV torsion was inversely related to LV mass (boys: r = -0.55, P = .001; girls: r = -0.46, P = .003) and end-diastolic volume (boys: r = -0.64, P < .001; girls: r = -0.36, P = .025) in both sexes. A difference in LV twist mechanics between endurance-trained and untrained cohorts is only apparent post-PHV, where structural and functional remodeling were related

Processing of ultrafine-size particulate metal matrix composites by advanced shear technology

Copyright @ 2009 ASM International. This paper was published in Metallurgical & Materials Transactions A 40A(3) and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this paper for a fee or for commercial purposes, or modification of the content of this paper are prohibited.Lack of efficient mixing technology to achieve a uniform distribution of fine-size reinforcement within the matrix and the high cost of producing components have hindered the widespread adaptation of particulate metal matrix composites (PMMCs) for engineering applications. A new rheo-processing method, the melt-conditioning high-pressure die-cast (MC-HPDC) process, has been developed for manufacturing near-net-shape components of high integrity. The MC-HPDC process adapts the well-established high shear dispersive mixing action of a twin-screw mechanism to the task of overcoming the cohesive force of the agglomerates under a high shear rate and high intensity of turbulence. This is followed by direct shaping of the slurry into near-net-shape components using an existing cold-chamber die-casting process. The results indicate that the MC-HPDC samples have a uniform distribution of ultrafine-sized SiC particles throughout the entire sample in the as-cast condition. Compared to those produced by conventional high-pressure die casting (HPDC), MC-HPDC samples have a much improved tensile strength and ductility.EP-SR

Mutations in multidomain protein MEGF8 identify a Carpenter syndrome subtype associated with defective lateralization

Carpenter syndrome is an autosomal-recessive multiple-congenital-malformation disorder characterized by multisuture craniosynostosis and polysyndactyly of the hands and feet; many other clinical features occur, and the most frequent include obesity, umbilical hernia, cryptorchidism, and congenital heart disease. Mutations of RAB23, encoding a small GTPase that regulates vesicular transport, are present in the majority of cases. Here, we describe a disorder caused by mutations in multiple epidermal-growth-factor-like-domains 8 (MEGF8), which exhibits substantial clinical overlap with Carpenter syndrome but is frequently associated with abnormal left-right patterning. We describe five affected individuals with similar dysmorphic facies, and three of them had either complete situs inversus, dextrocardia, or transposition of the great arteries; similar cardiac abnormalities were previously identified in a mouse mutant for the orthologous Megf8. The mutant alleles comprise one nonsense, three missense, and two splice-site mutations; we demonstrate in zebrafish that, in contrast to the wild-type protein, the proteins containing all three missense alterations provide only weak rescue of an early gastrulation phenotype induced by Megf8 knockdown. We conclude that mutations in MEGF8 cause a Carpenter syndrome subtype frequently associated with defective left-right patterning, probably through perturbation of signaling by hedgehog and nodal family members. We did not observe any subject with biallelic loss-of function mutations, suggesting that some residual MEGF8 function might be necessary for survival and might influence the phenotypes observed

Effective flexural stiffness of slender reinforced concrete columns under axial forces and biaxial bending

Most of the design codes (ACI-318-2008 and Euro Code-2-2004) propose the moment magnifier method in order to take into account the second order effect to design slender reinforced concrete columns. The accuracy of this method depends on the effective flexural stiffness of the column. This paper proposes a new equation to obtain the effective stiffness EI of slender reinforced concrete columns. The expression is valid for any shape of cross-section, subjected to combined axial loads and biaxial bending, both for short-time and sustained loads, normal and high strength concretes, but it is only suitable for columns with equal effective buckling lengths in the two principal bending planes. The new equation extends the proposed EI equation in the "Biaxial bending moment magnifier method" by Bonet et al. (2004) [6], which is valid only for rectangular sections. The method was compared with 613 experimental tests from the literature and a good degree of accuracy was obtained. It was also compared with the design codes ACI-318 (08) and EC-2 (2004) improving the precision. The method is capable to verify and design with sufficient accuracy slender reinforced concrete columns in practical engineering design applications. © 2010 Elsevier Ltd.The authors wish to express their sincere gratitude to the Spanish "Ministerio de Ciencia e Innovacion" for help provided through projects BIA2008-03734 and BIA2009-10207 and to the European Community with the Feder funds.Bonet Senach, JL.; Romero, ML.; Miguel Sosa, P. (2011). Effective flexural stiffness of slender reinforced concrete columns under axial forces and biaxial bending. Engineering Structures. 33:881-893. doi:10.1016/j.engstruct.2010.12.009S8818933

The rate of colonization by macro-invertebrates on artificial substrate samplers

The influence of exposure time upon macro-invertebrate colonization on modified Hester-Dendy substrate samplers was investigated over a 60-day period. The duration of exposure affected the number of individuals, taxa and community diversity. The numbers of individuals colonizing the samplers reached a maximum after 39 days and then began to decrease, due to the emergence of adult insects. Coefficients of variation for the four replicate samples retrieved each sampling day fluctuated extensively throughout the study. No tendencies toward increasing or decreasing coefficients of variation were noted with increasing time of sampler exposure. The number of taxa colonizing the samplers increased throughout the study period. The community diversity index was calculated for each sampling day and this function tended to increase throughout the same period. This supports the hypothesis that an exposure period of 6 weeks, as recommended by the United States Environmental Protection Agency, may not always provide adequate opportunity for a truly representative community of macro-invertebrates to colonize multiplate samplers. Many of the taxa were collected in quite substantial proportions after periods of absence or extreme sparseness. This is attributed to the growth of periphyton and the collection of other materials that created food and new habitats suitable for the colonization of new taxa. Investigation of the relationship between ‘equitability’ and length of exposure revealed that equitability did not vary like diversity with increased time of exposure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72073/1/j.1365-2427.1979.tb01522.x.pd

Social-ecological, motivational and volitional factors for initiating and maintaining physical activity in the context of HIV

Sport and exercise can have several health benefits for people living with HIV. These benefits can be achieved through different types of physical activity, adapting to disease progression, motivation and social-ecological options. However, physical activity levels and adherence to exercise are generally low in people living with HIV. At the same time, high drop-out rates in intervention studies are prevalent; even though they often entail more favourable conditions than interventions in the natural settings. Thus, in the framework of an intervention study, the present study aims to explore social-ecological, motivational and volitional correlates of South African women living with HIV with regard to physical activity and participation in a sport and exercise health promotion programme. The qualitative data was produced in the framework of a non-randomised pre-post intervention study that evaluated structure, processes and outcomes of a 10-week sport and exercise programme. All 25 participants of the programme were included in this analysis, independent of compliance. Data was produced through questionnaires, participatory group discussions, body image pictures, research diaries and individual semi-structured interviews. All participants lived in a low socioeconomic, disadvantaged setting. Hence, the psychological correlates are contextualised and social-ecological influences on perception and behaviour are discussed. The results show the importance of considering social-cultural and environmental influences on individual motives, perceptions and expectancies, the fear of disclosure and stigmatisation, sport and exercise-specific group dynamics and self-supporting processes. Opportunities and strategies to augment physical activity and participation in sport and exercise programmes in the context of HIV are discussed.Scopu

The Mathematical Universe

I explore physics implications of the External Reality Hypothesis (ERH) that there exists an external physical reality completely independent of us humans. I argue that with a sufficiently broad definition of mathematics, it implies the Mathematical Universe Hypothesis (MUH) that our physical world is an abstract mathematical structure. I discuss various implications of the ERH and MUH, ranging from standard physics topics like symmetries, irreducible representations, units, free parameters, randomness and initial conditions to broader issues like consciousness, parallel universes and Godel incompleteness. I hypothesize that only computable and decidable (in Godel's sense) structures exist, which alleviates the cosmological measure problem and help explain why our physical laws appear so simple. I also comment on the intimate relation between mathematical structures, computations, simulations and physical systems.Comment: Replaced to match accepted Found. Phys. version, 31 pages, 5 figs; more details at http://space.mit.edu/home/tegmark/toe.htm