Quantum integrability and exact solution of the supersymmetric U model with boundary terms

Quantum integrability is established for the one-dimensional supersymmetric U model with boundary terms by means of the quantum inverse-scattering method. The boundary supersymmetric U chain is solved by using the coordinate-space Bethe-ansatz technique and Bethe-ansatz equations are derived. This provides us with a basis for computing the finite-size corrections to the low-lying energies in the system. [S0163-1829(98)00425-1].

Energy as an entanglement witness for quantum many-body systems

We investigate quantum many-body systems where all low-energy states are entangled. As a tool for quantifying such systems, we introduce the concept of the entanglement gap, which is the difference in energy between the ground-state energy and the minimum energy that a separable (unentangled) state may attain. If the energy of the system lies within the entanglement gap, the state of the system is guaranteed to be entangled. We find Hamiltonians that have the largest possible entanglement gap; for a system consisting of two interacting spin-1/2 subsystems, the Heisenberg antiferromagnet is one such example. We also introduce a related concept, the entanglement-gap temperature: the temperature below which the thermal state is certainly entangled, as witnessed by its energy. We give an example of a bipartite Hamiltonian with an arbitrarily high entanglement-gap temperature for fixed total energy range. For bipartite spin lattices we prove a theorem demonstrating that the entanglement gap necessarily decreases as the coordination number is increased. We investigate frustrated lattices and quantum phase transitions as physical phenomena that affect the entanglement gap.

Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K-T boundary Takatika Grit

Cretaceous-Tertiaty (K-T) boundary (ca. 65 Ma) sections on a Southwest Pacific island containing dinosaurs were unknown until March 2003 when theropod bones were recovered from the Takatika Grit on the remote Chatham Islands (latitude 44 degrees S, longitude 176 degrees W), along the Chatham Rise. Tectonic and palaeontologic evidence support the eastward extension of a ca. 900 km land bridge that connected the islands to what is now New Zealand prior to the K-T boundary. The Chathams terrestrial fauna inhabited coastal, temperate environments along a low-lying, narrow, crustal extension of the New Zealand subcontinent, characterised by a tectonically dynamic, volcanic landscape with eroding hills (horsts) adjacent to flood plains and deltas, all sediments accumulating in grabens. This finger-like tract was blanketed with a conifer and clubmoss (Lycopodiopsida) dominated forest. The Chatham Islands region would have, along with New Zealand, provided a dinosaur island sanctuary after separating from the Gondwana margin ca. 80 Ma. (c) 2005 Elsevier B.V. All rights reserved.

Violation of multiparticle Bell inequalities for low- and high-flux parametric amplification using both vacuum and entangled input states

We show how polarization measurements on the output fields generated by parametric down conversion will reveal a violation of multiparticle Bell inequalities, in the regime of both low- and high-output intensity. In this case, each spatially separated system, upon which a measurement is performed, is comprised of more than one particle. In view of the formal analogy with spin systems, the proposal provides an opportunity to test the predictions of quantum mechanics for spatially separated higher spin states. Here the quantum behavior possible even where measurements are performed on systems of large quantum (particle) number may be demonstrated. Our proposal applies to both vacuum-state signal and idler inputs, and also to the quantum-injected parametric amplifier as studied by De Martini The effect of detector inefficiencies is included, and weaker Bell-Clauser-Horne inequalities are derived to enable realistic tests of local hidden variables with auxiliary assumptions for the multiparticle situation.

Low renin hypertensive states: perspectives, unsolved problems, future research

Some causes of low renin hypertension are familial with known genetic bases. One of them, primary aldosteronism, is specifically treatable by mineralocorticoid receptor blockers or by surgery, and has at least two different familial varieties. These have provided insights into its natural history, with long normotensive and normokalemic phases, and variable expression within the same family. Primary aldosteronism was considered rare, but recent work beginning in 1992 suggests that it might be the most common curable cause of hypertension, worth screening for in every hypertensive. Evidence is now compelling that inappropriate aldosterone for salt status can cause not only hypertension, but vascular inflammation and end-organ damage, preventable by mineralocorticoid receptor blockade.

Plasma renin and aldosterone measurements in low renin hypertensive states

Plasma renin concentrations are extremely low, requiring high sensitivity methods to detect low renin hypertensive states. Moreover, plasma prorenin must not cryoactivate to renin to avoid falsely high values. The enzyme kinetic plasma renin activity (PRA) test has the required sensitivity, whereas direct renin assays and PRA tests with short incubation times are usually not accurate enough. Test specificity is essential for plasma aldosterone. The Nichols Advantage aldosterone assay is fast and automated but requires great attention to quality control. Here, the impact of renin on the aldosterone:renin ratio as a screening test for primary aldosteronism is reviewed. A sensitive plasma renin test is essential for the diagnosis of low renin hypertensive states and, currently, can be consistently achieved only with the PRA radioimmunoassay.

Determination of chromophore charge states in the low pH color transition of the fluorescent protein Rtms5(H146S) via time-dependent DFT

The red fluorescent protein Rtms5H146S displays a transition from blue (absorbance λmax 590 nm) to yellow (absorbance λmax not, vert, similar453 nm) upon titration to low pH. The pKa of the reaction depends on the concentration of halide, offering promise for new expressible halide sensors. The protonation state involved in the low pH form of the chromophore remains, however, ambiguous. We report calculated excitation energies of different protonation states of an RFP chromophore model. These suggest that the relevant titration site is the phenoxy moiety of the chromophore, and the relevant base and conjugate acid are anionic and neutral chromophore species, respectively.

Prevalence of patient with low intensity pain symptom severity states during treatment with Rofecoxib and Ibuprofen for osteoarthritis

Aim of study: To examine the prevalence of low intensity symptom severity states in patients taking placebo, rofecoxib 12.5 mg once daily, rofecoxib 25 mg once daily, or ibuprofen 800 mg three times daily using a post-hoc definition of low pain intensity states (BLISS Index) based on the WOMAC Index. Methods: Two 6-week, double-blind, parallel-group, placebocontrolled, ibuprofen-comparator studies were conducted to measure the efficacy of rofecoxib in patients with knee or hip osteoarthritis. These studies employed a flare design requiring a minimum level of symptoms at entry following discontinuation of prior analgesics. The WOMAC Pain subscale (100 mm visual analog scale) was used as the pain measure. In separate analyses, WOMAC pain subscale scores from each patient were compared to five thresholds of pain:%5 mm, %10 mm, %15 mm, %20 mm, and %25 mm. The percent of patients with BLISS states (1) on average over 6 weeks, (2) at any time during the study, and (3) at week 6 was computed for each treatment group and threshold. The treatment group percentages were compared using Fisher’s exact test. Results: During the study, patients received placebo (N Z 143), rofecoxib 12.5 mg (N Z 461), rofecoxib 25 mg (N Z 459), or ibuprofen (N Z 465). For each pain threshold and treatment group, the percent of patients with BLISS states at any time (e.g., 50% for rofecoxib 25 mg) exceeded the percentage at week 6 (e.g., 40% for rofecoxib 25 mg) which, in turn, exceeded the percentage with BLISS states on average (e.g., 32% for rofecoxib 25 mg). The percentages of patients in the active treatment groups with BLISS states on average were significantly different than observed in the placebo group at the%15 mm threshold (8–11% points vs placebo, P ! 0.01), %20 mm level (10–15% points, P ! 0.01), and %25 mm level (14–17% points, P ! 0.001). Significant differences between the active treatments and placebo were also observed at the %10 mm threshold (8–9% points, P ! 0.05) for measurements at week 6 and at the%10 (12–14% points, P !0.001) and%5 mm thresholds (5–7% points, P ! 0.05) for patients with BLISS states at any time. Conclusion: These measures of BLISS states differentiate all three active treatment groups from placebo and further confirm, at an individual patient level, the clinical benefit of rofecoxib in the treatment of osteoarthritis. Furthermore, they provide information on the prevalence of patients achieving low (%15 mm, %20 mm, %25 mm), and very low (%5 mm, %10 mm) pain severity states.

What are the economic prospects of developing aquaculture in Queensland to supply the low price white fillet market? Lessons from the US channel catfish industry

The farming of channel catfish (Ictalurus punctatus) is the largest (by volume and value) and most successful (in terms of market impact) aquaculture industry in the United States of America. Farmed channel catfish is the most consumed (in terms of volume per capita) fish fillet in the U.S. market. Within Australia, it has long been suggested by researchers and industry that silver perch (Bidyanus bidyanus) and possibly other endemic teraponid species possess similar biological attributes for aquaculture as channel catfish and may have the potential to generate a similar industry. The current teraponid industry in Australia, however, shows very little resemblance to the catfish industry, either in production style or market philosophy. A well established budget framework from the literature on U.S. channel catfish farming has been adapted for cost and climate conditions of the Burdekin region, Queensland, Australia. Breakeven prices for the hypothetical teraponid farms were found to be up to 50% higher than those published for catfish farms however were much lower than those reported for silver perch production in Australia using current, endemic styles of production. The breakeven prices for the hypothetical teraponid farms were most sensitive (in order of significance) to feed prices, production rates, interest rates, fingerling prices and electricity prices. At equivalent feed costs the costs of production between the hypothetical catfish farms in the Mississippi, U.S. and the hypothetical teraponid farms in the Burdekin, Australia were remarkably similar. The cost of feeds suitable for teraponid production in Australia are currently around double that of catfish feeds in the U.S. Issues currently hindering the development of a large scale teraponid industry in Australia are discussed.

Quantum oscillations in quasi-one-dimensional metals with spin-density-wave ground states

We consider the magnetoresistance oscillation phenomena in the Bechgaard salts (TMTSF)(2)X, where X = ClO4, PF6, and AsF6 in pulsed magnetic fields to 51 T. Of particular importance is the observation of a new magnetoresistance oscillation for X = ClO4 in its quenched state. In the absence of any Fermi-surface reconstruction due to anion order at low temperatures, all three materials exhibit nonmonotonic temperature dependence of the oscillation amplitude in the spin-density-wave (SDW) state. We discuss a model where, below a characteristic temperature T* within the SDW state, a magnetic breakdown gap opens. [S0163-1829(99)00904-2].

Mortality variation across Australia: descriptive data for States and Territories, and statistical divisions

OBJECTIVE: To describe variation in all cause and selected cause-specific mortality rates across Australia. METHODS: Mortality and population data for 1997 were obtained from the Australian Bureau of Statistics. All cause and selected cause-specific mortality rates were calculated and directly standardised to the 1997 Australian population in 5-year age groups. Selected major causes of death included cancer, coronary artery disease, cerebrovascular disease, diabetes, accidents and suicide. Rates are reported by statistical division, and State and Territory. RESULTS: All cause age-standardised mortality was 6.98 per 1000 in 1997 and this varied 2-fold from a low in the statistical division of Pilbara, Western Australia (5.78, 95% confidence interval 5.06-6.56), to a high in Northern Territory-excluding Darwin (11.30, 10.67-11.98). Similar mortality variation (all p<0.0001) exists for cancer (1.01-2.23 per 1000) and coronary artery disease (0.99-2.23 per 1000), the two biggest killers. Larger variation (all p<0.0001) exists for cerebrovascular disease (0.7-11.8 per 10,000), diabetes (0.7-6.9 per 10,000), accidents (1.7-7.2 per 10,000) and suicide (0.6-3.8 per 10,000). Less marked variation was observed when analysed by State and Territory. but Northern Territory consistently has the highest age-standardised mortality rates. CONCLUSIONS: Analysed by statistical division, substantial mortality gradients exist across Australia, suggesting an inequitable distribution of the determinants of health. Further research is required to better understand this heterogeneity.

Low coral cover in a high-CO2 world

Coral reefs generally exist within a relatively narrow band of temperatures, light, and seawater aragonite saturation states. The growth of coral reefs is minimal or nonexistent outside this envelope. Climate change, through its effect on ocean temperature, has already had an impact on the world's coral reefs, with almost 30% of corals having disappeared since the beginning of the 1980s. Abnormally warm temperatures cause corals to bleach ( lose their brown dinoflagellate symbionts) and, if elevated for long enough, to die. Increasing atmospheric CO2 is also potentially affecting coral reefs by lowering the aragonite saturation state of seawater, making carbonate ions less available for calcification. The synergistic interaction of elevated temperature and CO2 is likely to produce major changes to coral reefs over the next few decades and centuries. Known tolerances of corals to projected changes to sea temperatures indicate that corals are unlikely to remain abundant on reefs and could be rare by the middle of this century if the atmospheric CO2 concentration doubles or triples. The combination of changes to sea temperature and carbonate ion availability could trigger large- scale changes in the biodiversity and function of coral reefs. The ramifications of these changes for the hundred of millions of coral reef - dependent people and industries living in a high- CO2 world have yet to be properly defined. The weight of evidence suggests, however, that projected changes will cause major shifts in the prospects for industries and societies that depend on having healthy coral reefs along their coastlines.

A low-temperature insulating phase at v=1.5 for 2D holes in high-mobility SiSi1-xGex heterostructures with Landau level degeneracy

Magneto-transport measurements of the 2D hole system (2DHS) in p-type Si-Si1-xGex heterostructures identify the integer quantum Hall effect (IQHE) at dominantly odd-integer filling factors v and two low-temperature insulating phases (IPs) at v = 1.5 and v less than or similar to 0.5, with re-entrance to the quantum Hall effect at v = 1. The temperature dependence, current-voltage characteristics, and tilted field and illumination responses of the IP at v = 1.5 indicate that the important physics is associated with an energy degeneracy of adjacent Landau levels of opposite spin, which provides a basis for consideration of an intrinsic, many-body origin.

Polychlorinated Dibenzodioxins and Dibenzofurans in Butter from Different States in Australia

Nine samples of butter from producers in various states of Australia were analysed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Detectable concentrations of 2,3,7,8-chlorine substituted PCDD/Fs were found in all samples. The mean PCDD/F concentration expressed as 2',3,7,8-TCDD equivalents (TEQs) was 0.19 pg TEQ g(-1) fat. The highest concentration (0.46 pg TEQ g(-1) fat) was observable in a sample from Victoria which is the most densely populated state. Overall the results indicate that PCDD/F concentrations in dairy products from Australia are low in comparison to the levels in dairy products of industrialized countries on the Northern Hemisphere. As expected, this study provides evidence that the environmental and consequently the human body burden of PCDD/ Fs to be relatively low in Australia.

A comparison of low-storage strategies for spectral analysis in dissipative systems: filter diagonalisation in the Lanczos representation and harmonic inversion of the Chebychev-order-domain autocorrelation function

We compare the performance of two different low-storage filter diagonalisation (LSFD) strategies in the calculation of complex resonance energies of the HO2, radical. The first is carried out within a complex-symmetric Lanczos subspace representation [H. Zhang, S.C. Smith, Phys. Chem. Chem. Phys. 3 (2001) 2281]. The second involves harmonic inversion of a real autocorrelation function obtained via a damped Chebychev recursion [V.A. Mandelshtam, H.S. Taylor, J. Chem. Phys. 107 (1997) 6756]. We find that while the Chebychev approach has the advantage of utilizing real algebra in the time-consuming process of generating the vector recursion, the Lanczos, method (using complex vectors) requires fewer iterations, especially for low-energy part of the spectrum. The overall efficiency in calculating resonances for these two methods is comparable for this challenging system. (C) 2001 Elsevier Science B.V. All rights reserved.