Measurement of solar UVB exposures in sea water with a high exposure dosimeter

For several decades, marine scientists have investigated the underwater ultraviolet light environment using a wide variety of spectroradiometric and radiometric equipment. These types of instruments are extremely useful for taking underwater measurements of the solar UV within a short window of time, for example recording fluctuations in UV levels caused by rapidly changing environmental parameters, like cloud cover or water turbidity. However, over long phases these spectroradiometers and radiometers become increasingly problematic to use, with high amounts of maintenance time necessary involving routine calibrations and corrections for the immersion effect. However, to supplement the short – term underwater measurements using spectroradiometers and radiometers, a new long – term dosimetric system employing Poly (2,6-dimethyl-1, 4-phenylene oxide) (PPO) film has been developed. The PPO film dosimeter has proven to be capable of measuring underwater UV dosages of at least five times that of the more commonly used polysulphone dosimeter, at a level of accuracy close to what would be expected of dosimetric measurements made in air provided that the necessary calibrations are completed correctly. This presentation details a measurement campaign made in a simulated sea water environment using a batch of PPO dosimeters set at different depths and aligned to a range of different inclinations and azimuths by means of attachment to a custom built dosimeter submersible float (DSF) unit. The results obtained from this measurement campaign were used to compute a diffuse attenuation coefficient (Kd) for the sea water. This Kd value was compared to a Kd value derived from results taken using a radiometer in the same water

UV protection and shade structures

[Abstract]: Broadband field measurements were conducted beneath three different sized public shade structures at a sub-tropical Southern Hemisphere site for relatively clear skies and for a changing solar zenith angle (SZA) of 13o to 76o. These data were compared to the diffuse UV to quantify the relationship between diffuse UV and the UV in the shade of the structures. On the horizontal plane, the ultraviolet protection factors (UPF) for the shade structures ranged from 1.5 to 18 for a decreasing SZA. The data from this research is significant, because it shows that as the SZA of the sun increases so does the relative proportion of scattered UV beneath the shade structures which in turn decreases the shade structures UPF. In Australia, erythemal UV in full sun can reach levels of approximately 2.5 MED/h or more in the middle of the day during winter. Therefore, it is necessary for people that live in similar latitudes to minimise UV exposure in all climatic conditions throughout the year. Based on this research, a standard for reporting the UV protection provided by shade structures is essential for the public to make an informed decision on the efficacy of particular structures in reducing personal UV exposure

An Empirical Determination Of The Electric Dipole Moment Function And Transition Probabilities Of Hydroxyl(chi(2)pi)

Although intensity distributions derived from hydroxyl, OH({dollar}X\sp2\pi{dollar}), airglow observations are routinely used to determine rotational temperatures and vibrational level populations, the transition probabilities required to do so are in fact inadequately known. The set now in common use has come under attack both on theoretical grounds (because of the choice of theoretical dipole moment used in its derivation) and on experimental grounds (because of its failure to represent accurately measured intensity ratios).;An electric dipole moment function (EDMF) for OH has been derived by combining recent high precision measurements of the permanent dipole moments with laboratory and airglow intensity measurements, including new night airglow measurements made specifically for this work. This empirical EDMF, while showing remarkable agreement with some a priori EDMF\u27s, differs sufficiently to produce transition probabilities which are in much better agreement with airglow observations than previously available sets

Environmental determinants of escape reflex performance in a freshwater oligochaete

This study examines the effects of a variety of environmental stresses on the physiological of selected neural elements on the rapid escape reflex behavior in two freshwater oligochaetes, Lumbriculus variegatus and Branchiura sowerbyi. The stresses include Cd, anoxia, pH, ammonia/ammonium, temperature, and repeated mechanosensory stimuli. Neural parameters that were studied included: touch sensitivity, giant fiber excitability, and initiation of giant fiber-mediated muscle potentials. The rationale for this study is that impairment of these functions due to environmental stresses could reduce the effectiveness of rapid escape behavior. The primary method for assessing effects was non-invasive extracellular recordings of giant fiber spike activity and corresponding muscle potentials. In addition, the concentration of metal-binding proteins, as a result of Cd pre-treatment, was also assessed;Pre-treatment with 0.01 ppm CdCl2 rescued worms from a 100% lethal Cd pulse (1 ppm CdCl2 for 30 min). This protection was correlated to increases in metal-binding protein concentration; maximum induction occurred after 48 h and persisted for at least 14 days. Acute (5 min) or prolonged (7 day) exposure to anoxia had no apparent effect of neural parameters associated with the rapid escape behavior. Exposure to a wide range of pH (4-8) also had no apparent effect on the neural parameters. Worms did not survive exposure to pHs outside this range (pH 3 or 9). Exposure to 260 ppm NH4OH (pH 9.2) for 30 min reduced giant fiber conduction velocity by approximately 50%. Conduction velocity continued to be affected at least 7 days after the exposure ended. Changing the pH of the 260 ppm NH4OH solution alleviated the effects of the exposure. Conduction velocity was also reduced as temperature decreased below 20 ∘C. No acclimation of conduction velocity occurred between worms maintained at 10, 21, or 30 ∘C. Below 10 ∘C, efferent connection failed and a muscle potential could not be evoked despite being able to touch-evoke giant fiber spikes at temperatures as low as 2 ∘C. Touch-evoked spikes were easier to initiate when a second spike was preceded by an initial giant fiber spike (30% vs. 60%, respectively)

Development of an improved shade environment for the reduction of personal UV exposure

The research from this project has quantified the solar UV environment beneath and surrounding typical local council public shade structures. The effects of changing seasons, atmospheric conditions, structural modifications and surrounding plant life on diffuse UV have been quantified. Strategies to improve current shade structures, so as to significantly reduce the levels of diffuse UV reaching the human body in the shade, have also been developed. For the shade structures used in this research it was found that ultraviolet protection factors ranged from 1.5 to 18.3 for a decreasing solar zenith angle. Correlations have been found relating diffuse erythemal UV to UV in the shade for clear skies and a changing solar zenith angle. The effect of changing atmospheric ozone levels on diffuse erythemal UV levels has been quantified. UV exposures were assessed for a decrease in scattered UV beneath specific shade structures by the use of two types of protection, namely, side-on polycarbonate sheeting and evergreen vegetation. Broadband radiometric and dosimetric measurements conducted in the shade of a scale model shade structure, during summer and winter, showed significant decreases in exposure of up to 65% for summer and 57% for winter when comparing the use and non-use of polycarbonate sheeting. Measurements conducted in the shade of four shade structures, with various amounts of vegetation blocking different sides, showed that adequate amounts and positioning of vegetation decreased the scattered UV in the shade by up to 89% when compared to the shade structure that had no surrounding vegetation. This research shows that major UV reduction could be achieved by the ‘shade creation and design industry’, and that shade guidelines should be updated as soon as possible

Dynamic Visualizations for the Analysis of Desert Tortoise Telemetry and Habitat in Joshua Tree National Park

Joshua Tree National Park (JOTR) has been monitoring their desert tortoise population’s telemetry since 2005 using transmitters attached to as many as 18 tortoises. JOTR needed to visualize tortoise telemetry data and temporal environmental datasets to see what factors may be affecting the movements of the tortoises. JOTR also needed to look at the telemetry data in relation to roads to see if curbing implementations have been effective. The foundation for this project is ArcMap™. This project includes various tools written in Python within ArcMap’s toolboxes that allow for automated data manipulation and analysis of the various datasets. These tools prepare the datasets for dynamic visualizations of the data in Google Earth®. Additionally, the preparation of the data will also enable it to be exploited by ArcGIS 10’s integrated time-visualization capability. ArcGIS Explorer™ can also be used to perform similar dynamic visualizations as Google Earth. The provided tools and visualizations aim to provide JOTR with a means to help analyze and monitor their tortoise population to improve their survivability

The Process of Adaptation in Inter-Firm Relationships

Ross Brennan and Peter W. Turnbull, 'The Process of Adaptation in Inter-Firm Relationships, in Proceedings of the 12th annual IMP Group conference, presented at Interaction, Relationships and Networks, University of Karlsruhe, Germany: IMP.Adaptations are an important, arguably a defining, component of a long-term buyer-seller relationship. Substantial research evidence exists on the nature of the adaptations which arise within such relationships. The processes involved in adapting for a customer or supplier organisation are not so well understood. Five process metaphors for adaptation within buyer-seller relationships are explored. Each is found helpful to some extent in illuminating the process of adaptation. The metaphors are found to be complementary, so that taken together they provide a coherent process view of buyer-seller adaptations.Final Published versio

A high-throughput screening method for determining the substrate scope of nitrilases

Nitrile compounds are intermediates in the synthesis of pharmaceuticals such as atorvastatin. We have developed a chromogenic reagent to screen for nitrilase activity as an alternative to Nessler's reagent. It produces a semi-quantifiable blue colour and hydrolysis of 38 nitrile substrates by 23 nitrilases as cell-free extracts has been shown

Short wavelength cut-offs and maximum spectral irradiance wavelengths comparisons of the spectra for erythema and pre-vitamin D3 synthesis

This paper has compared the short wavelength cut-offs and the wavelengths of the maximum irradiances for the biologically effective spectral UV for erythema (UVEry) and pre-vitamin D3 synthesis (UVD3) over a six month period for the range of solar zenith angles from 4.7o to 80o. When averaged over the six month period, the short wavelength cut-off for the UVD3 is higher by 0.9 nm than that for UVEry. The wavelength of the maximum spectral irradiance is higher for the UVD3 compared to the UVEry for SZA less than approximately 60o. For higher SZA, there is a change with the wavelength of the maximum spectral irradiance for UVD3 being reduced compared to that for the UVEry