Applications of spectral methods to turbulent magnetofluids in space and fusion research

Recent and potential applications of spectral method computation to incompressible, dissipative magnetohydrodynamics are surveyed. Linear stability problems for one dimensional, quasi-equilibria are approachable through a close analogue of the Orr-Sommerfeld equation. It is likely that for Reynolds-like numbers above certain as-yet-undetermined thresholds, all magnetofluids are turbulent. Four recent effects in MHD turbulence are remarked upon, as they have displayed themselves in spectral method computations: (1) inverse cascades; (2) small-scale intermittent dissipative structures; (3) selective decays of ideal global invariants relative to each other; and (4) anisotropy induced by a mean dc magnetic field. Two more conjectured applications are suggested. All the turbulent processes discussed are sometimes involved in current carrying confined fusion magnetoplasmas and in space plasmas

The diagnostic value of adenosine deaminase activity in the ascitic fluid of patients with tuberculous peritonitis

This study was designed to: 1. Examine the diagnostic value of ADA levels in ascitic fluid, 2. Establish the sensitivity and specificity of this test in the diagnosis of tuberculous peritonitis, in a large number of patients, 3. Establish levels of adenosine deaminase activity which give the best discriminatory information in patients with ascites. 4. Determine what conditions may give rise to false positive or false negative results. 5. Finally, the study was designed to assess the relative diagnostic accuracy of previously used biochemical and haematological data, such as ascites total protein and white cell count. The diagnostic value of these tests alone, and combined with ADA activity in a descriminant analysis, was compared with the diagnostic accuracy of adenosine deaminase activity alone

Maximally Entangled Mixed-State Generation via Local Operations

We present a general theoretical method to generate maximally entangled mixed states of a pair of photons initially prepared in the singlet polarization state. This method requires only local operations upon a single photon of the pair and exploits spatial degrees of freedom to induce decoherence. We report also experimental confirmation of these theoretical results.Comment: 5 pages, 2 figures, to be published in Physical Review

The light CP-even MSSM Higgs mass resummed to fourth logarithmic order

We present the calculation of the light neutral CP-even Higgs mass in the MSSM for a heavy SUSY spectrum by resumming enhanced terms through fourth logarithmic order (N$^3$LL), keeping terms of leading order in the top Yukawa coupling $\alpha_t$, and NNLO in the strong coupling $\alpha_s$. To this goal, the three-loop matching coefficient for the quartic Higgs coupling of the SM to the MSSM is derived to order $\alpha_t^2\alpha_s^2$ by comparing the perturbative EFT to the fixed-order expression for the Higgs mass. The new matching coefficient is made available through an updated version of the program Himalaya. Numerical effects of the higher-order resummation are studied using specific examples, and sources of theoretical uncertainty on this result are discussed.Comment: 26 pages, 3 figures, matches version published in EPJ

A new technique for the separation of radiophosphorus from sulfur

A new approach to the separation of radiophosphorus from sulfur has been found which makes a unique use of ion exchange resins. Separations using resin columns are especially suited to problems involving radioactivity since they require a minimum of handling

Hepatitis C - a South African perspective

The existence of non-A, non-B (NANB) hepatitis was established in the 1970s, when accurate serological tests allowed exclusion of hepatitis A and B viruses as the cause of most cases of post-transfusion hepatitis. The term 'hepatitis C' was coined after molecular cloning of nucleic acid from highly infectious sera of chimpanzees identified an RNA virus as the primary cause of post-transfusion hepatitis (PTH). Sequence analysis and expression of the RNA has shown it to be closely related to the flavi- and pestiviruses. It has marked genomic variability which may affect its biological and immunological characteristics, is transmitted parenterally and sporadically, by as yet unidentified routes, and causes chronic indolent liver disease in 50 - 75% of infected patients. It is associated with hepatocellular carcinoma, glomerulonephritis, cryoglobulinaemia, auto-immune liver disease, lymphocytic sialadenitis and porphyria cutanea tarda. Up to 500 million people worldwide may be infected with hepatitis C virus (HCV), and many questions about the disease remain unanswered. Therapy is still largely ineffective and our current understanding of the long-term natural history, our methods of diagnosis, therapy, prevention and immunisation are suboptimal

Selecting Acid-Soil Tolerant White Clover

A two-stage, tandem, recurrent-selection program is proposed to improve acid-soil tolerance of white clover, Trifolium repens L. In stage one, we evaluate root growth of very young seedlings, grown in an highly-acid Al toxic soil. Although the relationship between the acid-soil response of very young seedlings and that of mature white clover is unknown, the failure of white clover to become established on a highly-acid, Al-toxic soil suggests that establishment is a critical stage of plant development on such soils. In stage two we reevaluate genotypes selected in stage one, in a small-pot study at two lime levels, to separate the effects of plant vigor and acid-soil tolerance, account for any effects of growth stage on evaluation results and ensure that all genotypes selected are vigorous in soils with a higher pH