Management of cryptococcal meningitis in adults at Mthatha Hospital Complex, Eastern Cape, South Africa

Background. Cryptoccocal meningitis (CM) remains prevalent in HIV-infected individuals across South Africa (SA). Early diagnosis and management, aided by the existing Southern African HIV Clinicians Society (SAHIVSoc) 2007 guidelines on management of CM, could reduce the mortality associated with this condition. Objective. To review the management of adult patients with CM and adherence to the SAHIVSoc 2007 guidelines in a district hospital. Methods. A retrospective chart review of patients admitted with CM from December 2011 to May 2012 was performed. The following key recommendations of the guidelines were evaluated: measurement of cerebrospinal fluid (CSF) opening pressure at the first lumbar puncture (LP), prescription of amphotericin B (AMB)/fluconazole therapy, intravenous prehydration preceding administration of AMB, monitoring of renal function and performance of serial LPs to manage raised intracranial pressure (ICP). Results. A total of 57 patient charts were reviewed, of which 40 (70%) were of females. The mean age (range) of the cohort was 36 (21 - 60) years. Fifty-two (91%) patients presented with headache. Confusion was recorded in 30 (53%) and vomiting in 26 (46%). The major signs observed were fever (n=29 (51%)) and neck stiffness (n=34 (60%)). Fifty-five (96%) patients were HIVinfected at presentation, with a median (range) CD4+ count of 77 (13 - 90) cells/μl. None of the patients had a CSF opening pressure measured at first LP. AMB was used as an induction agent in 51 (89%) patients, of whom 47 (92%) completed 2 weeks of AMB. Of these 51, only 20 (40%) were prehydrated and 10 (18%) had two repeat LPs performed 1 week apart. Renal function was monitored in only 27 (53%) of the patients receiving AMB. This was done at baseline and twice weekly, and was consistent with the guidelines. No abnormality in renal function was recorded in these cases during the study. The mortality rate was 30% in the first 10 days of admission. Conclusion. This chart review showed inadequate adherence to the recommendations of the 2007 SAHIVSoc guidelines in the majority of cases except for the use of AMB as a first-line antifungal agent. Control of ICP and monitoring for drug toxicity were not done as per guidelines and may impact on clinical care and outcome. Despite this, the early 30% mortality is comparable with published reports from other regions in SA, but is higher than in developed health systems

Development and performance of the Fast Neutron Imaging Telescope for SNM detection

FNIT (the Fast Neutron Imaging Telescope), a detector with both imaging and energy measurement capabilities, sensitive to neutrons in the range 0.8-20 MeV, was initially conceived to study solar neutrons as a candidate design for the Inner Heliosphere Sentinel (IHS) spacecraft of NASA\u27s Solar Sentinels program and successively reconfigured to locate fission neutron sources. By accurately identifying the position of the source with imaging techniques and reconstructing the Watt spectrum of fission neutrons, FNIT can detect samples of special nuclear material (SNM), including heavily shielded and masked ones. The detection principle is based on multiple elastic neutron-proton scatterings in organic scintillators. By reconstructing n-p event locations and sequence and measuring the recoil proton energies, the direction and energy spectrum of the primary neutron flux can be determined and neutron sources identified. We describe the design of the FNIT prototype and present its energy reconstruction and imaging performance, assessed by exposing FNIT to a neutron beam and to a Pu fission neutron source

Development of the fast neutron imaging telescope

We report on the development of a next generation neutron telescope, with imaging and energy measurement capabilities, sensitive to neutrons in the 2-20 MeV energy range. The Fast Neutron Imaging Telescope (FNIT) was initially conceived to study solar neutrons as a candidate instrument for the Inner Heliosphere Sentinels (IHS) program under formulation at NASA. This detector is now being adapted to locate Special Nuclear Material (SNM) for homeland security purposes by detecting fission neutrons and reconstructing the image of their source. In either case, the detection principle is based on multiple elastic neutron-proton scatterings in organic scintillator. By reconstructing the scattering coordinates and measuring the recoil proton energy, the direction and energy of each neutron can be determined and discrete neutron sources identified. We describe the performance of the FNIT prototype, report on the current status of R&D efforts and present the results of recent laboratory measurements

Atmospheric neutron measurements with the SONTRAC science model

–The SOlar Neutron TRACking (SONTRAC) telescope was originally developed to measure the energy spectrum and incident direction of neutrons produced in solar flares, in the energy range 20 - 250 MeV. While developed primarily for solar physics, the SONTRAC detector may be employed in virtually any application requiring both energy measurement and imaging capabilities. The SONTRAC Science Model (SM) is presently being operated at the University of New Hampshire (UNH) as a ground-based instrument to investigate the energy spectrum, zenith and azimuth angle dependence of the cosmic-ray induced sea-level atmospheric neutron flux. SONTRAC measurements are based on the non-relativistic double scatter of neutrons off ambient protons within a block of scintillating fibers. Using the n-p elastic double-scatter technique, it is possible to uniquely determine the neutron’s energy and direction on an event-by-event basis. The 3D SM consists of a cube of orthogonal plastic scintillating fiber layers with 5 cm sides, read out by two CCD cameras. Two orthogonal imaging chains allow full 3D reconstruction of scattered proton tracks

A reservoir for inverse power law decoherence of a qubit

The exact dynamics of a Jaynes-Cummings model for a qubit interacting with a continuous distribution of bosons, characterized by a special form of the spectral density, is evaluated analytically. The special reservoir is designed to induce anomalous decoherence, resulting in an inverse power law relaxation, of power 3/2, over an evaluated long time scale. If compared to the exponential-like relaxation obtained from the original Jaynes-Cummings model for Lorentzian-type spectral density functions, decoherence is strongly suppressed. The special reservoir exhibits an upper band edge frequency coinciding with the qubit transition frequency. Known theoretical models of photonic band gap media suitable for the realization of the designed reservoir are proposed.Comment: 5 pages, 2 figure

Search for a Solution of the Pioneer Anomaly

In 1972 and 1973 the Pioneer 10 and 11 missions were launched. They were the first to explore the outer solar system and achieved stunning breakthroughs in deep-space exploration. But beginning in about 1980 an unmodeled force of \sim 8 \times 10^{-8} cm/s^2, directed approximately towards the Sun, appeared in the tracking data. It later was unambiguously verified as being in the data and not an artifact. The cause remains unknown (although radiant heat remains a likely origin). With time more and more effort has gone into understanding this anomaly (and also possibly related effects). We review the situation and describe ongoing programs to resolve the issue.Comment: 24 pages 8 figure

Design optimization and performance capabilities of the fast neutron imaging telescope (FNIT)

We describe the design optimization process and performance characterization of a next generation neutron telescope, with imaging and energy measurement capabilities, sensitive to neutrons in the 1-20 MeV energy range. The response of the Fast Neutron Imaging Telescope (FNIT), its efficiency in neutron detection, energy resolution and imaging capabilities were characterized through a combination of lab tests and Monte Carlo simulations. Monte Carlo simulations, together with experimental data, are also being used in the development and testing of the image reconstruction algorithm. FNIT was initially conceived to study solar neutrons as a candidate instrument for the Inner Heliosphere Sentinel (IHS) spacecraft. However, the design of this detector was eventually adapted to locate Special Nuclear Material (SNM) sources for homeland security purposes, by detecting fission neutrons. In either case, the detection principle is based on multiple elastic neutron-proton scatterings in organic scintillator. By reconstructing event locations and measuring the recoil proton energies, the direction and energy spectrum of the primary neutron flux can be determined and neutron sources identified. This paper presents the most recent results arising from our efforts and outlines the performance of the FNIT detector

Patients want to know about the \u27cardiac blues\u27

BACKGROUND: Much attention has been given to identifying and supporting the minority of patients who develop severe clinical depression after a cardiac event. However, relatively little has been given to supporting the many patients who experience transient but significant emotional disturbance that we term the \u27cardiac blues\u27. OBJECTIVE: The aim of this study was to investigate patients\u27 preferences regarding information provision about cardiac blues. METHODS: One hundred and sixty consecutive cardiac patients admitted to two Victorian hospitals in Australia were interviewed three times over six months. They were asked about emotional issues, including information provision preferences. RESULTS: Four out of five (81%) patients would like to have received information about the cardiac blues, but only a minority received this information. CONCLUSION: Most patients want to know about cardiac blues. The development and evaluation of resources for health professionals and patients to support recovery through cardiac blues appears warranted

Localization of Light: Dual Symmetry between Absorption and Amplification

We study the propagation of radiation through a disordered waveguide with a complex dielectric constant $\epsilon$, and show that dual systems, which differ only in the sign of the imaginary part of $\epsilon$, have the same localization length. Paradoxically, absorption and stimulated emission of radiation suppress the transmittance of the waveguide in the same way.Comment: Added a reference to the paper by Z.Q. Zhang, Phys.Rev.B. 52, 7960 (1995