Nasal disease and quality of life in athletes.

OBJECTIVES: Nasal disease imposes a significant disease burden upon the individual in the general population, but is relatively under studied in athletes. This study sought to define the frequency of nasal symptoms in the active population, and to quantify the impact of these symptoms on quality of life and on the frequency of upper respiratory tract infections. RESULTS: A total of 296 participants completed the study (246 athletes and 50 sedentary controls). Nasal symptoms were significantly more frequent in the active group than in the sedentary controls (70 per cent vs 52 per cent). Upper respiratory tract infections were significantly more common in athletes with regular nasal symptoms than in athletes without nasal symptoms. Quality-of-life scores, as measured by the 22-item Sino-Nasal Outcome Test, were significantly worse in athletes with regular nasal symptoms. CONCLUSION: This study suggests that regular exercise is associated with a significant increase in the prevalence of troubling nasal symptoms, and nasal symptoms in athletes are associated with increased susceptibility to upper respiratory tract infections. Quality of life was negatively affected, confirming the importance of nasal health to athlete welfare.

Potential role of endothelin receptor antagonists in the setting of cardiopulmonary bypass: relevance to myocardial performance.

The ET system is activated in cardiac surgical setting as evidenced by elevated systemic and myocardial ET-1 levels after coronary bypass grafting surgery which requires hypothermic cardioplegic arrest and cardiopulmonary bypass. Increased ET-1 may influence a number of clinical parameters in this setting. First, ET-1 may directly modulate myocardial contractile performance in the early postoperative period resulting in LV dysfunction and a complex postoperative course. Second, elevated ET-1 levels may exacerbate increased pulmonary vascular resistance and contribute to the development of transient pulmonary hypertension following bypass. Finally, augmented postoperative ET-1 levels could contribute to changes in the caliber and flow of vascular conduits used for coronary bypass. In this review, a current perspective on the ET system in the setting of cardiopulmonary bypass grafting surgery is provided and the potential use of ET receptor antagonists in this setting is discussed.

Low-order adaptive optics for free-space optoelectronic interconnects.

The concept of adaptive optics for improving the cost-performance of free-space optoelectronic interconnects is discussed. Adaptive optics as a design option for optical interconnect systems is presented and discussed. A practical demonstrator that performs low-order correction was built and tested. Slowly varying misalignments, including thermal effects, were compensated for in a 622-Mbit/s free-space optical data link.

Performance and design of InGaAs /InP photodiodes for single-photon counting at 1.55 microm.

The performance of selected, commercially available InGaAs/InP avalanche photodiodes operating in a photon-counting mode at an incident wavelength of 1.55 microm is described. A discussion on the optimum operating conditions and their relationship to the electric field distribution within the device is presented.

Optics in Computing: Introduction to the Feature issue.

This feature issue of Applied Optics on optics in computing comprises 14 papers. Most of the papers are expanded versions of papers presented at the Optical Society of America Topical Meeting on Optics in Computing held 16-21 March 1997 in Lake Tahoe, Nevada.

Optoelectronic Systems Based on InGaAs- Complementary-Metal-Oxide-Semiconductor Smart-Pixel Arrays and Free-Space Optical Interconnects.

Free-space optical interconnects have been identified as a potentially important technology for future massively parallel-computing systems. The development of optoelectronic smart pixels based on InGaAs/AlGaAs multiple-quantum-well modulators and detectors flip-chip solder-bump bonded onto complementary-metal-oxide-semiconductor (CMOS) circuits and the design and construction of an experimental processor in which the devices are linked by free-space optical interconnects are described. For demonstrating the capabilities of the technology, a parallel data-sorting system has been identified as an effective demonstrator. By use of Batcher's bitonic sorting algorithm and exploitation of a perfect-shuffle optical interconnection, the system has the potential to perform a full sort on 1024, 16-bit words in less than 16 mus. We describe the design, testing, and characterization of the smart-pixel devices and free-space optical components. InGaAs-CMOS smart-pixel, chip-to-chip communication has been demonstrated at 50 Mbits/s. It is shown that the initial system specifications can be met by the component technologies.

Time-of-Flight Optical Ranging System Based on Time-Correlated Single-Photon Counting.

The design and implementation of a prototype time-of-flight optical ranging system based on the time-correlated single-photon-counting technique are described. The sensor is characterized in terms of its longitudinal and transverse spatial resolution, single-point measurement time, and long-term stability. The system has been operated at stand-off distances of 0.5-5 m, has a depth repeatability of <30 mum, and has a lateral spatial resolution of <500 mum.

Malnutrition and microcephaly in Australian aboriginal children.

OBJECTIVE: To examine the association between malnutrition and microcephaly in the first two years of life. DESIGN: Cross-sectional study. SETTING AND PARTICIPANTS: Royal Darwin Hospital (a tertiary referral centre); 157 of 165 previously studied Aboriginal children aged under two years who were admitted with diarrhoea between May 1990 and April 1991. Birth weight, birth length, birth head circumference, admission head circumference and admission nutritional status were examined. Nutritional status was categorised according to World Health Organization (WHO) criteria for wasting (thinness) and stunting (shortness). Microcephaly on admission was defined as a head circumference less than the second percentile on Australian reference charts. Small-for-gestational-age (SGA) and birth microcephaly were defined as being less than the tenth percentile for an Australian hospitalised population, corrected for gestational age at confinement. Low birth weight (LBW) was defined as less than 2500 g. MAIN OUTCOME MEASURE: Microcephaly on admission. RESULTS: Of the 157 children, 76 (48%) were wasted, 36 (23%) stunted and 37 (24%) microcephalic on admission. A total of 26 (17%) children had been of LBW, 17 (11%) SGA and 21 (13%) microcephalic at birth. On univariate analysis, microcephaly on admission was associated with wasting (crude odds ratio [OR], 3.91; 95% confidence interval [CI], 1.6-9.7; P < 0.005), but not stunting. There were no significant associations between microcephaly on admission and LBW, being SGA, microcephaly at birth, age or sex. With multivariate analysis, birth head circumference was significantly associated with microcephaly on admission (adjusted OR, 3.62; 95% CI, 1.28-10.23; P < 0.05), as was wasting (adjusted OR, 4.38; 95% CI, 1.88-10.20; P < 0.001). CONCLUSIONS: Wasting was significantly associated with microcephaly, independent of intrauterine growth retardation (as measured by being SGA) and LBW. As malnutrition in critical periods of both intra- and extrauterine development may have irreversible effects on intellectual potential and behaviour, the emphasis on improved nutrition must begin during pregnancy, and should continue in infancy and early childhood.

Helicobacter pylori serology and the management of young dyspeptics: a UK survey of gastroenterologists and general practitioners with an interest in gastroenterology.

AIM: To survey the current use of Helicobacter pylori serology for pre-endoscopy screening and management of young dyspeptics amongst gastroenterologists and general practitioners with an interest in gastroenterology in the United Kingdom. METHODS: A postal questionnaire was sent to 536 members of the British Society of Gastroenterology and 164 members of the Primary Care Society in Gastroenterology. RESULTS: Of those who responded (66%), 25% of general practitioners and 17% of gastroenterologists were using H. pylori serology as a screening test for young dyspeptics. General practitioners and gastroenterologists differed in their use of serology to guide management strategies (P < 0.0003): general practitioners eradicate infection from sero-positive patients prior to endoscopy (92%), whilst the majority of gastroenterologists endoscope sero-positive patients before treatment (55%). More gastroenterologists (89%) would re-test all or selected patients to assess eradication compared to general practitioners (45%). 106 different drug regimes were being used as first line treatment. CONCLUSIONS: H. pylori serology as a pre-endoscopy screening test for young dyspeptic patients was used by only a fifth of respondents. There were wide variations in attitudes and practice in the way H. pylori serology was used in the management of young dyspeptics. Trials comparing clinical outcome and cost-effectiveness of different serology-based strategies are needed.

Laser depth measurement based on time-correlated single-photon counting.

A method for acquiring range data based on time-correlated single-photon counting is described. This method uses a short-pulse ( approximately 10-ps) laser diode, a detector based on a silicon single-photon avalanche diode, and standard photon-counting timing electronics. The accuracy of the technique has been measured as approximately +/-30 microm in a laboratory experiment and corresponds closely to the results of a theoretical simulation.

The 'expert' nurse comforter: perceptions of medical/surgical patients.

An interpretative study of Australian adult medical-surgical patients' experiences and perceptions of comfort and discomfort in hospital uncovered a number of themes. One theme, patients' perceptions of and experiences with nurses they called 'good' or 'expert', is the subject of this paper. Informants provided brief vignettes of 'expert' nurses and glimpses of skilled nursing that depicted nurses as important sources of comfort and well-being. Nurses who 'knew what they were doing' in intensive care units and in high-dependency, medical-surgical, postnatal and short-stay wards were reassuring, caring and 'expert'. Informants' descriptions of expert nursing are briefly compared with descriptions found in the professional nursing literature. Because nursing work is poorly understood and because it is immensely comforting for patients to know that nurses are both competent and caring, nursing comfort and safety work deserve to have a higher profile in the public perception of nursing.

Time-resolved photoluminescence measurements of InGaAs/ InP multiple-quantum-well structures at 1.3-µm wavelengths by use of germanium single-photon avalanche photodiodes.

A commercially available germanium avalanche photodiode operating in the single-photon-counting mode has been used to perform time-resolved photoluminescence measurements on InGaAs/lnP multiple-quantum-well structures. Photoluminescence in the spectral region of 1.3-1.48 µm was detected with picosecond timing accuracy by use of the time-correlated single-photon counting technique. The carrier dynamics were monitored for excess photogenerated carrier densities in the range 10(18)-10(15) cm(-3). The recombination time is compared for similar InGaAs-based quantum-well structures grown by use of different epitaxial processes.

Components for the implementation of free-space optical crossbars.

We describe an optical system developed to form the basis of a 64 × 64 free-space optical matrix-matrix crossbar switch. The design and performance of each of the main optical components is discussed: lenses, diffractive optical elements, and polarizing beamsplitters, together with the optomechanical hardware design. For these components, throughput levels of -6.9 dB have been achieved, which is compatible with full system operation at 10(-12) bit error rates at ≥270 Mbits s(-1).

Malnutrition among rural aboriginal children in the Top End of the Northern Territory.

OBJECTIVE: To calculate the minimum prevalence of malnutrition among rural Aboriginal children under two years of age in the Top End of the Northern Territory (NT) using World Health Organization (WHO) criteria. METHODS: We calculated weight-for-height and height-for-age Z-scores (WHO-endorsed references) for all children under two years who were admitted to hospital with diarrhoeal disease between May 1990 and April 1991. Weights recorded 48 hours after admission were used to allow for acute dehydration. Malnutrition was defined in terms of "wasting" and "stunting" when weight-for-height and height-for-age were more than two standard deviations below the median of the WHO reference population. The denominator population was calculated from NT Department of Health and Australian Bureau of Statistics data. RESULTS: From an average population of no more than 480 children under two years, 34% were admitted to hospital at least once with diarrhoeal disease in the 12 months; 59% were malnourished (wasting alone, 36%; stunting alone, 10%; both, 13%). In the study period an estimated minimum of 20% of all Aboriginal children in the Top End were malnourished (wasted, 12%; stunted, 3%; both, 5%). CONCLUSIONS: The 20% prevalence of malnutrition is many times higher than would be expected statistically, and higher than in many underdeveloped countries. International relief agencies regard a prevalence of wasting in children of more than 8% as a nutritional emergency. We urge that programs to alleviate the poor socioeconomic conditions, and mechanisms for early detection and intervention in childhood malnutrition, be offered to Aboriginal communities.

Impact of culture on pain management: an Australian nursing perspective.

Pain assessment and pain management are complex tasks. Knowledge and beliefs of patients, physicians, and nurses about pain are key determinants of clinical decision making. Despite new theoretical insights, routine approaches to pain assessment and management persist in practice. Culture is a potent force in shaping beliefs, behavior, and meaning about pain. In health care contexts, there may be conflict between care and cure and differing perceptions about the role and status of nurses that impinge on the provision of pain relief. The article explores aspects of culture, knowledge, and belief and their influence on pain management from an Australian perspective.

Diagnosing idiopathic dystonia: must it take so long?

Idiopathic dystonia is a chronic, disabling movement disorder. This study attempted to verify anecdotal evidence that sufferers experience delay in achieving a correct diagnosis. A survey of 133 patients revealed that diagnosis after first seeking help required a mean of 3.8 years. Diagnostic latency varied considerably, with 22 per cent of respondents reporting a diagnostic latency of more than five years, while a further 22 per cent reported a latency of one month or less, with a sample median of 1.5 years. Respondents consulted a mean of 8.3 practitioners, including a mean of 2.1 general practitioners and 1.6 neurologists. Results were consistent with reports of lengthy diagnostic delays and inappropriate referrals. Greater awareness of dystonia and referral of suspected cases to a neurologist interested in movement disorders are recommended.

Hominid radius from the middle Pliocene of Lake Turkana, Kenya.

A nearly complete left radius, KNM-ER 20419, was recovered from middle Pliocene sediments east of Lake Turkana, Kenya in 1988. Ape-like characteristics of the fossil include an eccentrically positioned articular fovea, relatively long radial neck, wide distal metaphysis, and large brachioradialis crest. The robustness of the radial neck in proportion to the radial head, and the semilunar shape of the distal diaphysis, however, clearly distinguish KNM-ER 20419 as hominid. The distal articular surface possesses a larger area for radius-lunate articulation than for radius and scaphoid, a radiocarpal arrangement that is associated with increased wrist adduction among quadrumanous climbers. Since this morphology is also found in hylobatids, Pongo, and other early australopithecines, it is argued to be plesiomorphic for hominoids. This further supports the argument that vertical climbing was an important locomotor behavior among both early hominoids and our more immediate prebipedal ancestors.

Improved method for determining the optical constants of thin films and its application to molecular-beam-deposited polycrystalline layers.

Polycrystalline, dielectric thin films are grown by the ultrahigh vacuum technique of molecular-beam deposition. A method of calculating the optical constants of such weakly absorbing, homogeneous layers from spectral transmission information alone, with no prior knowledge of their characteristics, is presented. Initially, the procedure uses transmission turning-point data to estimate refractive index and thickness by an analytical approach. These data are then fitted to a function that undergoes an iterative refinement routine by means of a weighted figure of merit to determine with good accuracy the film parameters as functions of wavelength. In this way the optimum conditions for the deposition of materials such as ZnS, ZnSe, LiF, CaF(2), and BaF(2) are found.

An analysis of codon usage in mammals: selection or mutation bias?

A new statistical test has been developed to detect selection on silent sites. This test compares the codon usage within a gene and thus does not require knowledge of which genes are under the greatest selection, that there exist common trends in codon usage across genes, or that genes have the same mutation pattern. It also controls for mutational biases that might be introduced by the adjacent bases. The test was applied to 62 mammalian sequences, and significant codon usage biases were detected in all three species examined (humans, rats, and mice). However, these biases appear not to be the consequence of selection, but of the first base pair in the codon influencing the mutation pattern at the third position.

Similarities in Aegyptopithecus and Afropithecus facial morphology.

Recently discovered cranial fossils from the Oligocene deposits of the Fayum depression in Egypt provide many details of the facial morphology of Aegyptopithecus zeuxis. Similar features are found in the Miocene hominoid Afropithecus turkanensis. Their presence is the first good evidence of a strong phenetic link between the Oligocene and Miocene hominoids of Africa. A comparison of trait lists emphasizes the similarities of the two fossil species, and leads us to conclude that the two fossil genera share many primitive facial features. In addition, we studied facial morphology using finite-element scaling analysis and found that the two genera show similarities in morphological integration, or the way in which biological landmarks relate to one another in three dimensions to define the form of the organism. Size differences between the two genera are much greater than the relatively minor shape differences. Analysis of variability in landmark location among the four Aegyptopithecus specimens indicates that variability within the sample is not different from that found within two samples of modern macaques. We propose that the shape differences found among the four Aegyptopithecus specimens simply reflect individual variation in facial characteristics, and that the similarities in facial morphology between Aegyptopithecus and Afropithecus probably represent a complex of primitive facial features retained over millions of years.