A search for predictive biomarkers of ovine pre-partum vaginal prolapse

Ovine pre-partum vaginal prolapse (known as bearings in sheep) occurs within a few weeks prior to lambing and unless treated both ewes and unborn lambs will die. It is a worldwide problem with no clear aetiology. Rates of prolapse in New Zealand typically vary from 0.1 to 2% per annum, varying between seasons and farms. In order to determine preclinical changes leading to prolapse, blood samples were collected prior to prolapse occurring and analysed for changes in both protein and specific hormone and vitamin levels. 650 ewes were ear tagged and blood samples were taken one month prior to the beginning of lambing; 28 of these ewes subsequently prolapsed. Using an improved proteomic method plasma samples were subjected to 2D DIGE (two dimensional differential in gel electrophoresis) to determine if there were differences between the pre-prolapse and non-prolapsing ewes. Acidic isoforms of haptoglobin, a major acute phase protein in ruminants, increased approximately 3-fold in ewes prior to prolapse occurring. Total haptoglobin quantitation was confirmed with an independent assay. Although another plasma protein, α-1B-glycoprotein, was down regulated close to prolapse, the biological significance of this is unknown. While vitamin D levels were not associated with subsequent prolapse there was, however, a negative correlation between cortisol and days to prolapse from sampling (r² = 0.36); i.e. ewes sampled closest to prolapse had higher plasma cortisol concentrations than controls. This raises the possibility that the ewes which prolapsed may have been suffering from chronic stress. Further research is needed.

The perceived effects and comfort of various body armour systems on police officers while performing occupational tasks

Background

The nature of police work often necessitates use of Individual Light Armour Vests (ILAVs) for officer protection. Previous research has demonstrated various biomechanical and physical performance impacts of ILAVs, however, little knowledge exists on the individual officer’s perceptions of ILAV. The aim of this study was to investigate officers’ perceptions of the impacts of three different ILAVs and normal station wear whilst performing police occupational tasks.

Methods

A prospective, within subjects, repeated measures design was employed in which 11 serving police officers wore each of three different types of body armour (ILAV A, ILAV B or ILAV C) and normal station wear for a full day while performing tasks including a simulated victim drag, a patrol vehicle exit and a marksmanship shoot. Ratings of Perceived Exertion (RPE) and a Visual Analogue Scale (VAS; − 10 to + 10) were used to examine officer perceptions of each ILAV. Finally, officers were asked to indicate areas of both discomfort and comfort of each ILAV on a mannequin chart.

Results

Officers perceived less effort was required for the victim drag whilst wearing ILAV B (RPE = 3.6/10) when compared to ILAV A, ILAV C and even station wear (RPE = 4.7/10, 4.0/10, 3.8/10, respectively). A positive impact on performance was perceived for ILAV B (VAS = + 0.26) when performing a patrol vehicle exit and sprint task but not for the other two ILAVs (VAS = − 3.58, − 0.55, − 0.85, respectively). Officers perceived a positive impact of ILAV B (VAS = + 2.7) and station wear (VAS = + 1.4) and a negative impact of ILAVs A and C (VAS = − 2.1, − 1.7 respectively) on marksmanship. Despite all armour types being criticized for discomfort, ILAV B received lower ratings of discomfort overall, and some positive comments regarding both comfort and performance.

Conclusions

Officers perceived ILAV B to have positive effects on task performance. It was also rated more comfortable than the other two, possibly due to a longer torso design which shifted load from the shoulders to the hips and pelvis. Officer perceptions of comfort and effects on occupational performance should be considered when designing and procuring armour systems. Although ILAVs may be similar, perceived impacts may vary between officers.

A simple but precise method for quantitative measurement of the quality of the laser focus in a scanning optical microscope

We report a method for characterizing the focussing laser beam exiting the objective in a laser scanning microscope. This method provides the size of the optical focus, the divergence of the beam, the ellipticity and the astigmatism. We use a microscopic‐scale knife edge in the form of a simple transmission electron microscopy grid attached to a glass microscope slide, and a light‐collecting optical fibre and photodiode underneath the specimen. By scanning the laser spot from a reflective to a transmitting part of the grid, a beam profile in the form of an error function can be obtained and by repeating this with the knife edge at different axial positions relative to the beam waist, the divergence and astigmatism of the postobjective laser beam can be obtained. The measured divergence can be used to quantify how much of the full numerical aperture of the lens is used in practice. We present data of the beam radius, beam divergence, ellipticity and astigmatism obtained with low (0.15, 0.7) and high (1.3) numerical aperture lenses and lasers commonly used in confocal and multiphoton laser scanning microscopy. Our knife‐edge method has several advantages over alternative knife‐edge methods used in microscopy including that the knife edge is easy to prepare, that the beam can be characterized also directly under a cover slip, as necessary to reduce spherical aberrations for objectives designed to be used with a cover slip, and it is suitable for use with commercial laser scanning microscopes where access to the laser beam can be limited.

Energy shedding during nonlinear self-focusing of optical beams

Self-focusing of intense laser beams and pulses of light in real nonlinear media is in general accompanied by material losses that require corrections to the conservative Nonlinear Schrödinger equations describing their propagation. Here we examine loss mechanisms that exist even in lossless media and are caused by shedding of energy away from the self-trapping beam making it to relax to an exact solution of lower energy. Using the conservative NLS equations with absorbing boundary conditions we show that energy shedding not only occurs during the initial reshaping process but also during oscillatory propagation induced by saturation of the nonlinear effect. For pulsed input we also show that, depending on the sign and magnitude of dispersion, pulse splitting, energy shedding, collapse or stable self-focusing may result.

Increased signals from short-wavelength-excited fluorescent molecules using sub-Ti:Sapphire wavelengths

We report the use of an all-solid-state ultrashort pulsed source specifically for two-photon microscopy at wavelengths shorter than those of the conventional Ti:Sapphire laser. Our approach involves sum-frequency mixing of the output from an optical parametric oscillator (λ= 1400-1640 nm) synchronously pumped by a Yb-doped fibre laser (λ= 1064 nm), with the residual pump radiation. This generated an fs-pulsed output tunable in the red spectral region (λ= 620-636 nm, ~150 mW, 405 fs, 80 MHz, M(2) ~ 1.3). We demonstrate the performance of our ultrashort pulsed system using fluorescently labelled and autofluorescent tissue, and compare with conventional Ti:Sapphire excitation. We observe a more than 3-fold increase in fluorescence signal intensity using our visible laser source in comparison with the Ti:Sapphire laser for two-photon excitation at equal illumination peak powers of 1.16 kW or less.

A compact instrument for adjusting laser beams to be accurately coincident and coaxial and its use in biomedical imaging using wave-mixed laser sources

Biomedical imaging applications that involve nonlinear optical processes such as sum-frequency generation (SFG) and four-wave mixing require that the pulses are synchronized in time and the beams are coaxial to better than 400 μrad. For this reason, folding mirrors are normally used to extend the beam path over a few meters so that detectors can be put into the beams to check their overlap at the start of a long path and also at the end of it. We have made a portable instrument with a footprint of only 22 cm × 11 cm × 16 cm that uses a short focal length lens and a telephoto combination for viewing the near-field and far-field simultaneously. Our instrument is simple to build and use, and we show its application in coherent anti-Stokes Raman scattering microscopy and SFG-based two-photon fluorescence microscopy.

Relaxed damage threshold intensity conditions and nonlinear increase in the conversion efficiency of an optical parametric oscillator using a bi-directional pump geometry

A novel bi-directional pump geometry that nonlinearly increases the nonlinear optical conversion efficiency of a synchronously pumped optical parametric oscillator (OPO) is reported. This bi-directional pumping method synchronizes the circulating signal pulse with two counter-propagating pump pulses within a linear OPO resonator. Through this pump scheme, an increase in nonlinear optical conversion efficiency of 22% was achieved at the signal wavelength, corresponding to a 95% overall increase in average power. Given an almost unchanged measured pulse duration of 260 fs under optimal performance conditions, this related to a signal wavelength peak power output of 18.8 kW, compared with 10 kW using the traditional single-pass geometry. In this study, a total effective peak intensity pump-field of 7.11 GW/cm(2) (corresponding to 3.55 GW/cm(2) from each pump beam) was applied to a 3 mm long periodically poled lithium niobate crystal, which had a damage threshold intensity of 4 GW/cm(2), without impairing crystal integrity. We therefore prove the application of this novel pump geometry provides opportunities for power-scaling of synchronously pumped OPO systems together with enhanced nonlinear conversion efficiency through relaxed damage threshold intensity conditions.

Life cycle assessment part 1: framework, goal and scope definition, inventory analysis, and applications

Sustainable development requires methods and tools to measure and compare the environmental impacts of human activities for the provision of goods and services (both of which are summarized under the term "products"). Environmental impacts include those from emissions into the environment and through the consumption of resources, as well as other interventions (e.g., land use) associated with providing products that occur when extracting resources, producing materials, manufacturing the products, during consumption/use, and at the products' end-of-life (collection/sorting, reuse, recycling, waste disposal). These emissions and consumptions contribute to a wide range of impacts, such as climate change, stratospheric ozone depletion, tropospheric ozone (smog) creation, eutrophication, acidification, toxicological stress on human health and ecosystems, the depletion of resources, water use, land use, and noise-among others. A clear need, therefore, exists to be proactive and to provide complimentary insights, apart from current regulatory practices, to help reduce such impacts. Practitioners and researchers from many domains come together in life cycle assessment (LCA) to calculate indicators of the aforementioned potential environmental impacts that are linked to products-supporting the identification of opportunities for pollution prevention and reductions in resource consumption while taking the entire product life cycle into consideration. This paper, part 1 in a series of two, introduces the LCA framework and procedure, outlines how to define and model a product's life cycle, and provides an overview of available methods and tools for tabulating and compiling associated emissions and resource consumption data in a life cycle inventory (LCI). It also discusses the application of LCA in industry and policy making. The second paper, by Pennington et al. (Environ. Int. 2003, in press), highlights the key features, summarises available approaches, and outlines the key challenges of assessing the aforementioned inventory data in terms of contributions to environmental impacts (life cycle impact assessment, LCIA).

Sampling artifacts from the use of denuder tubes with glycerol based coatings in the measurement of atmospheric particulate matter

Chemical speciation studies use sampling configurations that often require the deployment of denuder tubes of various types to measure certain species or control particulate sampling artifacts. Concurrent sets of measurements on Teflon membrane and quartz filters in specific sampling configurations were used to evaluate the potential influence of denuder tubes with glycerol-based coatings on particulate mass and carbon measurements on downstream filters. Positive biases were observed in the measurement of gravimetric mass and carbon on Teflon and quartz filters, respectively, downstream of sodium carbonate/ glycerol and citric acid/glycerol coated denuder tubes relative to those without upstream denuder tubes. The magnitude of the bias is dependent on the level of ambient particulate loading.

Cognitive-behavioural assessment and treatment of maladaptive help-seeking behaviour in a patient with schizophrenia

OBJECTIVE

Maladaptive help-seeking behaviour in psychiatric patients is a significant problem for public mental health services, yet it is not addressed in the mainstream literature. We present a report on the successful treatment of a person with schizophrenia who displayed this common dilemma for patients and clinicians.

CLINICAL PICTURE

A 31-year-old man with borderline intellectual functioning had a 10-year history of schizophrenia marked by negative features. He frequently presented in crisis to public mental health services, the local hospital, and his general practitioner; this resulted in excessive use of services, including admissions.

TREATMENT

The patient was reassessed from a cognitive-behavioural perspective rather than a syndromal perspective. Specific behaviours were modified, cognitions were identified, challenged and restructured, and other service providers were provided with an alternative to admission or acute community care.

OUTCOME

At 24 months the maladaptive behaviour remains in remission.

CONCLUSIONS

Behavioural problems in persons with chronic schizophrenia may be effectively treated by reconceptualising the behaviour as distinct from the major diagnosis.

Asthma aggravation, combustion, and stagnant air

BACKGROUND

The relationship between current concentrations of ambient air pollution and adverse health effects is controversial. We report a meteorological index of air stagnation that is associated with daily visits to the emergency department for asthma in two urban areas.

METHODS

Data on daily values of a stagnation persistence index and visits to the emergency department for asthma were collected for approximately two years in Spokane, Washington, USA and for 15 months in Seattle, Washington, USA. The stagnation persistence index represents the number of hours during the 24 hour day when surface wind speeds are less than the annual hourly median value, an index readily available for most urban areas. Associations between the daily stagnation persistence index and daily emergency department visits for asthma were tested using a generalised additive Poisson regression model. A factor analysis of particulate matter (PM(2.5)) composition was performed to identify the pollutants associated with increased asthma visits.

RESULTS

The relative rate of the association between a visit to the emergency department for asthma and the stagnation persistence index was 1. 12 (95% CI 1.05 to 1.19) in Spokane and 1.21 (95% CI 1.09 to 1.35) in Seattle for an increase of 11 and 10 hours, respectively, of low wind speed in a given day. The stagnation persistence index was only correlated with one set of factor loadings; that cluster included the stagnation persistence index, carbon monoxide, and organic/elemental carbon.

CONCLUSION

Increased air stagnation was shown to be a surrogate for accumulation of the products of incomplete combustion, including carbon monoxide and fine particulate levels of organic and elemental carbon, and was more strongly associated with asthma aggravation than any one of the measured pollutants.

Spatial and temporal measurements of NO2 in an urban area using continuous mobile monitoring and passive samplers

This paper describes the use of a continuous mobile monitor and passive samplers to estimate the spatial distribution of NO2 in an urban area for the purpose of siting a continuous monitor to measure population exposure. Monitoring sites were sites selected based on the State and Local Air Monitoring Stations (SLAMS) and National Air Monitoring Station (NAMS) siting criteria required by the U.S. Environmental Protection Agency (U.S. EPA). SLAMS monitoring objectives define scales in which the NO2 concentration and land use are homogeneous. The SLAMS scales relevant to NO2 monitoring for NAMS NO2 monitoring sites are neighborhood (0.5 to 4 km), and urban (several to 50 km). SLAMS siting objectives also define four categories of sites: highest concentration, representative concentration, impacts of major sources, and background sites. Mobile monitoring with a Scintrex LMA-3 luminal monitor was used on a neighborhood scale to measure the NO2 concentration at sites that covered a large geographical area. Passive samplers were then located at candidate mobile monitoring locations for long-term sampling which covered the neighborhood to the urban scale. These two methods complement each other by combining short-term continuous measurements and integrated long-term measurements which reflect the National Ambient Air Quality Standard for NO2 which is based on an annual average. The neighborhood site with the highest concentration was not only in the area of highest population density, but was also representative of the larger urban scale. The magnitude of this urban scale is approximately 20 km.

An association between fine particles and asthma emergency department visits for children in Seattle

Asthma is the most common chronic illness of childhood and its prevalence is increasing, causing much concern for identification of risk factors such as air pollution. We previously conducted a study showing a relationship between asthma visits in all persons < 65 years of age to emergency departments (EDs) and air pollution in Seattle, Washington. In that study the most frequent zip codes of the visits were in the inner city. The Seattle-King County Department of Public Health (Seattle, WA) subsequently published a report which showed that the hospitalization rate for children in the inner city was over 600/100,000, whereas it was < 100/100,000 for children living in the suburbs. Therefore, we conducted the present study to evaluate whether asthma visits to hospital emergency departments in the inner city of Seattle were associated with outdoor air pollution levels. ED visits to six hospitals for asthma and daily air pollution data were obtained for 15 months during 1995 and 1996. The association between air pollution and childhood ED visits for asthma from the inner city area with high asthma hospitalization rates were compared with those from lower hospital utilization areas. Daily ED counts were regressed against fine particulate matter (PM), carbon monoxide (CO), sulfur dioxide, and nitrogen dioxide using a semiparametric Poisson regression model. Significant associations were found between ED visits for asthma in children and fine PM and CO. A change of 11 microg/m3 in fine PM was associated with a relative rate of 1.15 [95% confidence interval (CI), 1.08-1.23]. There was no stronger association between ED visits for asthma and air pollution in the higher hospital utilization area than in the lower utilization area. These findings were seen when estimated PM2.5 concentrations were below the newly adopted annual National Ambient Air Quality Standard of 15 microg/m3.

An association between fine particles and asthma emergency department visits for children in Seattle

Asthma is the most common chronic illness of childhood and its prevalence is increasing, causing much concern for identification of risk factors such as air pollution. We previously conducted a study showing a relationship between asthma visits in all persons < 65 years of age to emergency departments (EDs) and air pollution in Seattle, Washington. In that study the most frequent zip codes of the visits were in the inner city. The Seattle-King County Department of Public Health (Seattle, WA) subsequently published a report which showed that the hospitalization rate for children in the inner city was over 600/100,000, whereas it was < 100/100,000 for children living in the suburbs. Therefore, we conducted the present study to evaluate whether asthma visits to hospital emergency departments in the inner city of Seattle were associated with outdoor air pollution levels. ED visits to six hospitals for asthma and daily air pollution data were obtained for 15 months during 1995 and 1996. The association between air pollution and childhood ED visits for asthma from the inner city area with high asthma hospitalization rates were compared with those from lower hospital utilization areas. Daily ED counts were regressed against fine particulate matter (PM), carbon monoxide (CO), sulfur dioxide, and nitrogen dioxide using a semiparametric Poisson regression model. Significant associations were found between ED visits for asthma in children and fine PM and CO. A change of 11 microg/m3 in fine PM was associated with a relative rate of 1.15 [95% confidence interval (CI), 1.08-1.23]. There was no stronger association between ED visits for asthma and air pollution in the higher hospital utilization area than in the lower utilization area. These findings were seen when estimated PM2.5 concentrations were below the newly adopted annual National Ambient Air Quality Standard of 15 microg/m3.

Episodes of high coarse particle concentrations are not associated with increased mortality

Fine particle concentration (i.e., particles <2.5 microm in aerodynamic diameter; PM2.5), but not coarse particle concentration, was associated with increased mortality in six U.S. cities. Others criticized this result, arguing that it could result from differences in measurement error between the two size ranges. Fine particles are primarily from combustion of fossil fuel, whereras coarse particles (i.e., particles between 2.5 and 10 microm in aerodynamic diameter) are all crustal material, i.e., dust. One way to determine if coarse particles are a risk for mortality is to identify episodes of high concentrations of coarse, but not fine, particles. Spokane, Washington, is located in an arid area and is subject to occasional dust storms after crops have been harvested. Between 1989 and 1995, we identified 17 dust storms in Spokane. The 24-hr mean PM10 concentration during those storms was 263 microg/m3. Using control dates that were the same day of the year in other years (but with no dust storm on that day) and that had a mean PM10 concentration of 42 microg/m3, we compared the rate of nonaccidental deaths on the episode versus nonepisode days. There was little evidence of any risk [relative risk (RR) = 1.00; 95% confidence interval (CI), 0.81-1.22] on the episode days. Defining episode deaths as those occurring on the same or following day as the dust storm produced similar results (RR = 1.01; CI, 0.87-1.17). Sensitivity analyses, which tested more extensive seasonal control, produced smaller estimates. We conclude that coarse particles from windblown dust are not associated with mortality risk.

Airborne Particulate Matter Size Distributions in an Arid Urban Area

While there is a growing body of data on the health effects of particulate matter, there is little information available from areas that experience frequent dust storms, such as Spokane, WA. As part of a three-year study to investigate the health effects associated with exposure to atmospheric aerosols, ambient particulate matter in Spokane is being characterized according to particle size and chemical composition. In this report, particulate matter concentrations measured using continuous tapered-element oscillating microbalances for three size ranges are discussed. Particles with aerodynamic diameters less than 10 micrometers (PM₁₀), less than 2.5 micrometers (PM₂₅), and less than 1.0 micrometer (PM_1.0) were measured at a residential site; PM₁₀ and PM_2.5 were measured at an industrial site. Based upon 1.5 years of data, PM₁₀ was found, on average, to consist of approximately 40% PM_2.5 at the industrial site and approximately 50% at the residential site, with higher fractions (up to 50% at the industrial site and up to 80% at the residential site) observed in the late fall or early winter (October-November). At the residential site, PM₂₅ was comprised of approximately 80% particles 1.0 micrometer and smaller. Only one windblown dust storm occurred during the sampling period, on July 24, 1994, during which both PM₁₀ and PM_2.5 concentrations were enhanced.

Effects of ambient air pollution on nonelderly asthma hospital admissions in Seattle, Washington, 1987-1994

As part of the Clean Air Act, Congress has directed EPA to set air quality standards to protect sensitive population groups from air pollutants in the ambient environment. People with asthma represent one such group. We undertook a study of the relation between measured ambient air pollutants in Seattle and nonelderly hospital admissions with a principal diagnosis of asthma. We regressed daily hospital admissions to local hospitals for area residents from 1987 through 1994 on particulate matter less than 10 and 2.5 microm in aerodynamic diameter (PM10 and PM2.5, respectively); coarse particulate mass; sulfur dioxide (SO2); ozone (O3); and carbon monoxide (CO) in a Poisson regression model with control for time trends, seasonal variations, and temperature-related weather effects. With the exception of seasonally monitored O3, we supplemented incomplete pollutant measures in a multiple imputation model to create a complete time series of exposure measures. We found an estimated 4-5% increase in the rate of asthma hospital admissions associated with an interquartile range change in PM (19 microg/m3 PM(10),11.8 microg/m3 PM2.5, and 9.3 microg/m3 coarse particulate mass) lagged 1 day; relative rates were as follows: for PM10, 1.05 [95% confidence interval (CI) = 1.02-1.08]; for PM2.5, 1.04 (95% CI = 1.02-1.07); and for coarse particulate mass, 1.04 (95% CI = 1.01-1.07). In single-pollutant models we also found that a 6% increase in the rate of admission was associated with an interquartile range change in CO (interquartile range, 924 parts per billion; 95% CI = 1.03-1.09) at a lag of 3 days and an interquartile range change in O3 (interquartile range, 20 parts per billion; 95% CI = 1.02-1.11) at a lag of 2 days. We did not observe an association for SO2. We found PM and CO to be jointly associated with asthma admissions. We estimated the highest increase in risk in the spring and fall seasons.

Mental health and general practice: improving linkages using a total quality management approach

This paper reports on a project to implement total quality management strategies to improve the linkages between general practitioners and specialist mental health services. The project implemented a process of change and objectively assessed the success of the process. The project involved all mental health staff (n = 100) in the St George Division of Psychiatry and Mental Health. General practitioners registered with the St George Division of General Practice were invited to participate in the change process. The project showed that the attempts to engage general practitioners in the ongoing care of patients with chronic mental illness is unlikely to be successful until mental health services promote general practitioner linkages as an ongoing service goal, relevant at all levels of delivery.