Metrological challenges for measurements of key climatological observables: Oceanic salinity and pH, and atmospheric humidity. Part 1: Overview.

Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth's radiation balance, atmospheric water vapour is the strongest "greenhouse" gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organisations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.

Automated high precision secondary pH measurements.

A new setup for high precision, automated secondary pH measurements together with a reference measurement procedure has been developed and tested in interlaboratory comparisons using buffers pH 4.005, pH 7.000, and pH 10.012 at 25 °C and 37 °C. Using primary buffers as standards, a standard uncertainty in pH better than 0.005 can be reached. The central measuring device is a one piece, thermostatted cell of PFA (perfluoroalkoxy) with a built-in Hamilton(®) Single Pore™ Glass electrode. Due to its flow-through principle this device allows pH measurements with low consumption of measurement solutions. The very hydrophobic and smooth PFA as construction material facilitates complete emptying of the cell. Furthermore, the tempering unit affords very precise temperature control and hence contributes to the low target uncertainty of the produced secondary buffer solutions. Use of a symmetric measurement sequence and the two point calibration was sufficient to reach high precision and accuracy.

Decreased circulating CD34+ stem cells in early Alzheimer's disease: Evidence for a deficient hematopoietic brain support?

Hematopoietic stem cells contribute to mammalian brain tissue regeneration by transdifferentiation processes. We found decreased counts of circulating CD34+ cells in early Alzheimer's dementia (AD; P = 0.01), which significantly correlated with age (r = -0.661; P = 0.001), cerebrospinal fluid beta-amyloid (Abeta)1-42 (r = -0.467; P = 0.025) and most pronounced the Abeta42/40 ratio (r = -0.688; P = 0.005). Our data suggest a deficient regenerative hematopoietic support for the central nervous system in early AD.

Traceability of pH measurements by glass electrode cells: performance characteristic of pH electrodes by multi-point calibration.

Routine pH measurements are carried out with pH meter-glass electrode assemblies. In most cases the glass and reference electrodes are thereby fashioned into a single probe, the so-called 'combination electrode' or simply 'the pH electrode'. The use of these electrodes is subject to various effects, described below, producing uncertainties of unknown magnitude. Therefore, the measurement of pH of a sample requires a suitable calibration by certified standard buffer solutions (CRMs) traceable to primary pH standards. The procedures in use are based on calibrations at one point, at two points bracketing the sample pH and at a series of points, the so-called multi-point calibration. The multi-point calibration (MPC) is recommended if minimum uncertainty and maximum consistency are required over a wide range of unknown pH values. Details of uncertainty computations for the two-point and MPC procedure are given. Furthermore, the multi-point calibration is a useful tool to characterise the performance of pH electrodes. This is demonstrated with different commercial pH electrodes. ELECTRONIC SUPPLEMENTARY MATERIAL is available if you access this article at http://dx.doi.org/10.1007/s00216-002-1506-5. On that page (frame on the left side), a link takes you directly to the supplementary material.

The clown doctors.

BACKGROUND: In 1996 The Humour Foundation was established in Australia, drawing on inspiration from the work of Patch Adams and the Clown Care Unit in New York. The mission statement of the Foundation is to introduce and promote the health benefits of humour to patients, their families and health care professionals. OBJECTIVE: To describe the work of the Clown Doctors in Australia and the role of humour in relieving suffering. DISCUSSION: Clown Doctor Units have been established at several major hospitals throughout Australia. They use performance skills, humour, empathy and sensitivity to support, nourish, divert and help patients (and staff) cope with difficult situations.

Improved traceability of pH measurements.

Traceability is a prerequisite for the comparability and uniformity of measurements. Although pH-measurements are carried out on a large scale in laboratory and industry, the problems involved in the traceability of pH values have not adequately been solved in the past. The comparability of pH measurements is limited, among other parameters, by the accuracy of the pH values of the standard buffer solutions used to calibrate the pH meter-electrode assemblies. The measured pH(X) value must be traceable to primary standard pH(PS) values through an unbroken chain of comparisons, all values having stated uncertainties. A new primary standard measurement device for pH is used to certify primary pH reference materials from which these secondary reference materials can be derived.

Playground accidents.

To study the causes and sequelae of playground accidents we analysed, in a retrospective study, 374 playground accidents. Questionnaires were sent to the parents and 103 parents (28%) provided detailed information on the playground accidents of their children. Thirty-one percent of the children injured in playground accidents sustained fractures of the extremities or concussion of the brain. Swings, slides, climbing frames, metal bars and merry-go-round accidents accounted for 71% of the 338 playground equipment-related accidents, whereas 36 accidents (10%) occurred without the use of playground equipment. The majority of these accidents were caused by children fighting. Rope-plank-type swings were frequently involved in backward falling accidents and 86% of the slide accidents were fall accidents. Climbing frames should not be taller than 1.6 m. Further efforts are mandatory to create and maintain playgrounds which help children develop their skills with a minimal risk to injury.

Health care organizational uses of information technology.

Let's say that, by having read the many inspiring articles on medical informatics in this issue of Physician Executive, you are now ready to move ahead with some serious applications of information systems in your organization. Or, you were already a believer in the usefulness of information technology (IT), and are wondering how to proceed. What types of systems should your organization be looking at to acquire or build? How should you get to there from here? Perhaps you'll find what you're looking for in what follows--an initial roadmap through organizational "IT Land."

A comprehensive framework for I/S strategic planning.

Too often hospital information services departments fail to create a strategic plan or make, at best, a half-hearted attempt at it. And many times, sincere efforts are waylaid by poor preparation or inadequate communication with users and management. By applying a systematic planning methodology, however, many pitfalls can be avoided.

Information systems support for healthcare quality: Part II.

In the second and final part of his series of quality management, healthcare information systems consultant Peter Spitzer, M.D., describes how I/S can support quality healthcare services by improving the care-delivery process and by providing the data needed for quality support, monitoring and management.

Information systems support for healthcare quality: a comprehensive framework.

Although management concepts for delivering quality products and services have been employed extensively in other industries, their inroads into healthcare have been comparatively slight. In the first of a two-part series, healthcare information systems consultant Peter Spitzer, M.D., sets forth a framework for defining high-quality healthcare delivery, and he tells how information systems can be put to work to achieve this goal.

HL7, MEDIX and the pursuit of the unified standard.

The move toward open systems environments in healthcare computing has gained momentum in recent years. The authors, both deeply involved in the development of standard communication protocols for disparate systems, explain the status of current convergence efforts both here and abroad, with emphasis on HL7 and MEDIX.

Chronic fatigue syndrome and the diagnostic utility of antibody to Epstein-Barr virus early antigen.

Antibody to Epstein-Barr virus (EBV) early antigen has been said to be the most specific indicator of symptomatic chronic EBV infection. We studied the clinical utility of this serologic test in the evaluation of patients with chronic fatigue. Thirty patients with chronic fatigue and highly elevated titers of antibody to early antigen (greater than or equal to 1:160) were compared with 30 age- and sex-matched controls with no antibody to early antigen. There were no significant differences noted between patients and controls at the initial evaluation (symptoms, physical examination, laboratory data). Follow-up information, available for 15 matched pairs, showed no differences in outcome between patients and controls. We conclude that the antibody to EBV early antigen is not helpful in the clinical evaluation of patients with chronic fatigue.

Synergistic activity between vancomycin or teicoplanin and gentamicin or tobramycin against pathogenic diphtheroids.

The in vitro activities of vancomycin and teicoplanin alone and in combination with gentamicin or tobramycin were studied by time-kill techniques with 11 strains of pathogenic diphtheroids (Corynebacterium group JK). The activities of vancomycin and teicoplanin were similar (MIC for 90% of strains tested [MIC90], 1 microgram/ml), as were those of gentamicin and tobramycin (the MIC90 was 1 microgram/ml for five aminoglycoside-susceptible strains, and the MIC90 was greater than 1,024 micrograms/ml for six aminoglycoside-resistant strains). No consistent synergistic killing could be demonstrated by the combination of glycopeptide and aminoglycoside antibiotics at arbitrarily chosen concentrations within the range of clinically achievable levels. However, by careful adjustment of both vancomycin and gentamicin concentrations within a narrow range below the MIC of each antibiotic, synergistic killing could be seen with an aminoglycoside-susceptible strain but not with an aminoglycoside-resistant strain. Synergism between glycopeptide and aminoglycoside antibiotics occurs with some diphtheroid organisms, but it may not be clinically relevant.

Comparative in vitro activity of the new cyclic lipopeptide LY146032 against Corynebacterium species.

Agar dilution and time-kill techniques were used to assess the in vitro activity of LY146032 and several other antibacterial agents against Corynebacterium spp. The activity of LY146032 was similar to that of vancomycin and teicoplanin. Synergistic killing by a combination of LY146032 and gentamicin could be demonstrated under certain carefully controlled conditions.

In vitro and in vivo activity of LY 146032, a new cyclic lipopeptide antibiotic.

The in vitro activity of LY 146032, a cyclic lipopeptide antibiotic belonging to the class of agents designated A21978C, was compared with those of vancomycin, cefpirome, cefotaxime, and clindamycin against selected gram-positive bacteria. The new drug inhibited all staphylococcal isolates, including methicillin-resistant strains, at concentrations of less than or equal to 1.0 microgram/ml. The activity of LY 146032 was comparable to that of vancomycin against most streptococci, but the latter demonstrated greater potency against Streptococcus faecium and penicillin-resistant strains of pneumococci and viridans group streptococci. LY 146032 was markedly less active than vancomycin against Listeria monocytogenes (MICs for 90% of strains tested, 16 and 1.0 microgram/ml, respectively). The activity of LY 146032 was enhanced as the concentration of calcium in the test medium was increased. MBCs were within eightfold of the MIC for each of 12 strains tested. In a rat model of enterococcal endocarditis, the administration of LY 146032 resulted in increased survival and a reduction in the bacterial titer within cardiac vegetations compared with untreated control animals.