A practical scheme for quantum computation with any two-qubit entangling gate

Which gates are universal for quantum computation? Although it is well known that certain gates on two-level quantum systems (qubits), such as the controlled-not (CNOT), are universal when assisted by arbitrary one-qubit gates, it has only recently become clear precisely what class of two-qubit gates is universal in this sense. Here we present an elementary proof that any entangling two-qubit gate is universal for quantum computation, when assisted by one-qubit gates. A proof of this important result for systems of arbitrary finite dimension has been provided by J. L. and R. Brylinski [arXiv:quant-ph/0108062, 2001]; however, their proof relies upon a long argument using advanced mathematics. In contrast, our proof provides a simple constructive procedure which is close to optimal and experimentally practical [C. M. Dawson and A. Gilchrist, online implementation of the procedure described herein (2002), http://www.physics.uq.edu.au/gqc/].Comment: 3 pages, online implementation of procedure described can be found at http://www.physics.uq.edu.au/gqc

Mechanism of Vanadium Leaching during Surface Weathering of Basic Oxygen Furnace Steel Slag Blocks: A Microfocus X-ray Absorption Spectroscopy and Electron Microscopy Study

© 2017 American Chemical Society. Basic oxygen furnace (BOF) steelmaking slag is enriched in potentially toxic V which may become mobilized in high pH leachate during weathering. BOF slag was weathered under aerated and air-excluded conditions for 6 months prior to SEM/EDS and μXANES analysis to determine V host phases and speciation in both primary and secondary phases. Leached blocks show development of an altered region in which free lime and dicalcium silicate phases were absent and Ca-Si-H was precipitated (CaCO 3 was also present under aerated conditions). μXANES analyses show that V was released to solution as V(V) during dicalcium silicate dissolution and some V was incorporated into neo-formed Ca-Si-H. Higher V concentrations were observed in leachate under aerated conditions than in the air-excluded leaching experiment. Aqueous V concentrations were controlled by Ca 3 (VO 4 ) 2 solubility, which demonstrate an inverse relationship between Ca and V concentrations. Under air-excluded conditions Ca concentrations were controlled by dicalcium silicate dissolution and Ca-Si-H precipitation, leading to relatively high Ca and correspondingly low V concentrations. Formation of CaCO 3 under aerated conditions provided a sink for aqueous Ca, allowing higher V concentrations limited by kinetic dissolution rates of dicalcium silicate. Thus, V release may be slowed by the precipitation of secondary phases in the altered region, improving the prospects for slag reuse

Would Functional Agricultural Foods Improve Human Health?

Concern over diet-health relationships has moved to the forefront of public health concerns in the UK and much of the developed world. It has been estimated, for example, that obesity costs the UK National Health Service up to £6b per year (Rayner and Scarborough, 2005), but if all consumers were to follow recommended healthy eating guidelines there would be major implications for food consumption, land use and international trade (Srinivasan et al, 2006). This is unlikely to happen, at least in the short term, but it is realistic to anticipate some dietary adjustment toward the recommendations, resulting in an improvement in diet quality (Mazzocchi et al, 2007). Although consumers are reluctant to make major changes to their diets, they may be prepared to substitute existing foods for healthier alternatives. Three of the most prominent nutritional recommendations are to consume more fruit and vegetables, which contain phytochemicals beneficial to health, reduce consumption of saturated fatty acids (SFA) and increase intake of long-chain n-3 fatty acids (FA). In the first case, consumption of fruit and vegetables has been stable at around three 80 g portions per person per day according to the Health Survey for England. It is estimated that 42,200 deaths per year could be avoided in England and 411,000 Quality Adjusted Life Years (QALYs) could be saved if fruit and vegetable consumption were increased to the recommended 5 portions per day (Ofcom 2006). As well as continuing to encourage people to eat more, it could be desirable to ‘intensify’ the beneficial phytochemical content of existing fruit and vegetables.Agribusiness, Agricultural and Food Policy, Farm Management, Food Consumption/Nutrition/Food Safety, Industrial Organization,

Mechanism of Vanadium Leaching during Surface Weathering of Basic Oxygen Furnace Steel Slag Blocks: A Microfocus X-ray Absorption Spectroscopy and Electron Microscopy Study

Basic oxygen furnace (BOF) steelmaking slag is enriched in potentially toxic V which may become mobilized in high pH leachate during weathering. BOF slag was weathered under aerated and air-excluded conditions for 6 months prior to SEM/EDS and μXANES analysis to determine V host phases and speciation in both primary and secondary phases. Leached blocks show development of an altered region in which free lime and dicalcium silicate phases were absent and Ca–Si–H was precipitated (CaCO₃ was also present under aerated conditions). μXANES analyses show that V was released to solution as V(V) during dicalcium silicate dissolution and some V was incorporated into neo-formed Ca–Si–H. Higher V concentrations were observed in leachate under aerated conditions than in the air-excluded leaching experiment. Aqueous V concentrations were controlled by Ca₃(VO₄)₂ solubility, which demonstrate an inverse relationship between Ca and V concentrations. Under air-excluded conditions Ca concentrations were controlled by dicalcium silicate dissolution and Ca–Si–H precipitation, leading to relatively high Ca and correspondingly low V concentrations. Formation of CaCO₃ under aerated conditions provided a sink for aqueous Ca, allowing higher V concentrations limited by kinetic dissolution rates of dicalcium silicate. Thus, V release may be slowed by the precipitation of secondary phases in the altered region, improving the prospects for slag reuse

Validity and worth in the science curriculum: learning school science outside the laboratory

It is widely acknowledged that there are problems with school science in many developed countries of the world. Such problems manifest themselves in a progressive decline in pupil enthusiasm for school science across the secondary age range and the fact that fewer students are choosing to study the physical sciences at higher levels and as careers. Responses to these developments have included proposals to reform the curriculum, pedagogy and the nature of pupil discussion in science lessons. We support such changes but argue from a consideration of the aims of science education that secondary school science is too rooted in the science laboratory; substantially greater use needs to be made of out-of-school sites for the teaching of science. Such usage should result in a school science education that is more valid and more motivating and is better at fulfilling defensible aims of school science education. Our contention is that laboratory-based school science teaching needs to be complemented by out-of-school science learning that draws on the actual world (e.g. through fieldtrips), the presented world (e.g. in science centres, botanic gardens, zoos and science museums) and the virtual worlds that are increasingly available through information and communications technologies (ICT)

Quantum dynamics as a physical resource

How useful is a quantum dynamical operation for quantum information processing? Motivated by this question we investigate several strength measures quantifying the resources intrinsic to a quantum operation. We develop a general theory of such strength measures, based on axiomatic considerations independent of state-based resources. The power of this theory is demonstrated with applications to quantum communication complexity, quantum computational complexity, and entanglement generation by unitary operations.Comment: 19 pages, shortened by 3 pages, mainly cosmetic change

Mutations in GATA2 cause primary lymphedema associated with a predisposition to acute myeloid leukemia (Emberger syndrome).

We report an allelic series of eight mutations in GATA2 underlying Emberger syndrome, an autosomal dominant primary lymphedema associated with a predisposition to acute myeloid leukemia. GATA2 is a transcription factor that plays an essential role in gene regulation during vascular development and hematopoietic differentiation. Our findings indicate that haploinsufficiency of GATA2 underlies primary lymphedema and predisposes to acute myeloid leukemia in this syndrome

Platelet Factor 4 Activity against P. falciparum and Its Translation to Nonpeptidic Mimics as Antimalarials

SummaryPlasmodium falciparum pathogenesis is affected by various cell types in the blood, including platelets, which can kill intraerythrocytic malaria parasites. Platelets could mediate these antimalarial effects through human defense peptides (HDPs), which exert antimicrobial effects by permeabilizing membranes. Therefore, we screened a panel of HDPs and determined that human platelet factor 4 (hPF4) kills malaria parasites inside erythrocytes by selectively lysing the parasite digestive vacuole (DV). PF4 rapidly accumulates only within infected erythrocytes and is required for parasite killing in infected erythrocyte-platelet cocultures. To exploit this antimalarial mechanism, we tested a library of small, nonpeptidic mimics of HDPs (smHDPs) and identified compounds that kill P. falciparum by rapidly lysing the parasite DV while sparing the erythrocyte plasma membrane. Lead smHDPs also reduced parasitemia in a murine malaria model. Thus, identifying host molecules that control parasite growth can further the development of related molecules with therapeutic potential

Inflammatory bowel disease, such as Ulcerative colitis, is a risk factor for recurrent thromboembolic events: a case report

Ulcerative colitis (UC), a member of the family of inflammatory bowel disease (IBD), occurs worldwide. It has an incidence which in recent years has been rising in areas such as Southern Europe and Asia, while remaining relatively constant in Northern Europe and North America

The burden and determinants of post-TB lung disease in Tanzanian adults: a cross-sectional study

BACKGROUND: Post-TB lung disease (PTLD) is an important but under-recognised chronic respiratory disease in high TB burden settings such as Tanzania. METHODS: This was a cross-sectional survey of adults within 2 years of completion of TB treatment in Kilimanjaro, Tanzania. Data were collected using questionnaires (symptoms and exposures), spirometry and chest radiographs to assess outcome measures, which were correlated with daily life exposures, including environment and diet. RESULTS: Of the 219 participants enrolled (mean age: 45 years ± 10; 193 [88%] males), 98 (45%) reported chronic respiratory symptoms; 46 (22%) had received treatment for TB two or more times; and HIV prevalence was 35 (16%). Spirometric abnormalities were observed in 146 (67%). Chest X-ray abnormalities occurred in 177 (86%). A diagnosis of PTLD was made in 200 (91%), and half had clinically relevant PTLD. The prevalence of ≥Grade 3 modified Medical Research Council chronic bronchitis and dyspnoea was respectively 11% and 26%. Older age, multiple episodes of TB and poverty indicators were linked with clinically relevant PTLD. CONCLUSIONS: We found a substantial burden of PTLD in adults who had recently completed TB treatment in Tanzania. There is a pressing need to identify effective approaches for both the prevention and management of this disease