SPATIAL ECOLOGY AND HABITAT USE OF THE WESTERN MASSASAUGA (SISTRURUS TERGEMINUS) IN NEBRASKA

We used radiotelemetry during 2004 and 2005 to investigate seasonal movements and habitat use and to improve our understanding of how land management practices were affecting Western Massasauga (Sistrurus tergeminus) populations in Nebraska. We found Western Massasaugas to brumate in crayfish burrows 100% of the time, and spring emergence occurred during March - April. The longest movements occurred during May when snakes were moving away from brumation sites to summer habitat, after which movements decreased until a second peak in August. We did not find significant differences between male and female activity area, range length, total distance moved, daily movement, or distance from spring and fall brumation sites. However the core activity range of females was significantly less than that of males. During the active season, grassland habitat was used 75.6% of the time compared to habitats of grassland-shrubs (10.7%), hydrophilic vegetation (9.1%), woodlands (3.1%), and shrublands (1.5%). Identifying variations in a species spatial ecology is important for achieving long-term conservation goals because life history events, resource availability, and land management practices may have an effect on seasonal movements and habitat use. The results of our study demonstrate the need for, and some of the necessary data for, improved land management planning in order to meet conservation needs of the Western Massasauga in Nebraska

1952 The Analysis

https://jdc.jefferson.edu/analysis/1012/thumbnail.jp

Seasonal and sex-specific differences in feeding site attendance by red foxes Vulpes vulpes

Food provided by householders represents a key resource for urban red foxes Vulpes vulpes. Using long-term video footage, we examined how patterns of feeding site attendance varied with season, sex and likely residence status. For foxes attending frequently (>15%) we found feeding site attendance highest for females in spring, probably because of feeding dependent young, and lowest for both sexes in autumn because of changes in seasonal food abundance or in time spent in other activities. For infrequent attenders (<15%), females attended most often in autumn and winter, coinciding with the dispersal period. Male attendance was not higher during the breeding season. Our combined results show how feeding site attendance changes throughout the year relative to potential intrinsic and extrinsic factors

Investigating impacts of calibration methodology and irradiance variations on lightweight drone-based sensor derived surface reflectance products

This is the final version. Available from SPIE via the DOI in this recordSPIE Remote Sensing 2019, 9-12 September 2019, Strasbourg, FranceThe miniaturisation of multispectral sensors in recent years have resulted in a proliferation of applications particularly in vegetation-focused studies using lightweight drones. Multi-camera arrays (MCAs), capable of capturing information over different wavelength intervals using separate cameras with specific band-pass filters, are now commonplace in this field. However, data from MCAs require a considerable amount of geometric and radiometric corrections if high quality reflectance products are to be delivered. Some aspects of this workflow can be handled by commercial software packages (e.g. Pix4D and Agisoft Metashape), using black box algorithms, however radiometric uncertainties within products are not reported to the end-user by the software. We present the results of two experiments using a low-cost MCA complete with irradiance sensor (Parrot Sequoia), which set out to assess the accuracy and consistency of hemispherical-conical surface reflectance factors from MCA data. Using reference panels in the field, we found that the empirical line method (ELM) generated the smallest RMSEs (0.0037) when compared to simplified single-panel based workflows; while for the latter there was little difference between using a calibrated Spectralon® panel or grey card imaged prior to the flight (0.0215 vs 0.0154 average over the four bands). Errors for a vegetated target within the survey flight were larger and comparable for all cases. Furthermore, a study on median vegetation index values for single vegetation canopies showed that illumination correction using irradiance data still yields significant differences in resulting values between two acquisitions during changing direct and diffuse irradiance conditions. We therefore highlight the importance of critical assessment prior to integrating drone derived MCA-measured reflectance factors into further geospatial workflows.European Union Horizon 202

Chemical immersion coatings to improve biological degradability of magnesium substrates for potential orthopaedic applications

Historically, cobalt-chromium, stainless steel and titanium alloys have been the main principal materials used in a variety of medical procedures for load-bearing implants in the body. Magnesium and magnesium-based alloys have the potential to be used as short-term structural support during the healing process of damaged hard tissues and diseased bone. Unlike traditional biologically compatible metals, which are not biologically degradable, magnesium based alloys offer both biological degradability and biological absorbability. Despite the many advantages offered by magnesium, its rapid degradation rate in the highly aggressive and corrosive body fluid environment has severely limited its present day medical application. This article reviews the chemical immersion technique for producing calcium phosphate coatings on magnesium substrates for slowing down the degradation rate while maintaining the biological compatibility and absorbability

Biosynthesis of silver nanoparticles using indigenous Xanthorrhoea glauca leaf extract and their antibacterial activity against Escherichia coli and Staphylococcus epidermis

Background: This study for the first time presents an environmentally friendly, room temperature procedure for synthesizing silver (Ag) nanoparticles via the leaf extract taken from Xanthorrhoea glauca. Methods: The simple and straightforward green chemistry based technique uses the leaf extract that acts as both reducing agent and capping agent to produce Ag nanoparticles which are subsequently quantified using advanced characterisation techniques. In addition, antibacterial studies were conducted using the Kirby-Bauer sensitivity method. Results: Advanced characterisation revealed the synthesised particles had a variety of shapes including cubes, truncated triangular and hexagonal plates, and ranged in size from 50 nm up to 200 nm. The Gram-positive bacteria Staphylococcus epidermis showed the maximum zone of inhibition at 11 mm. Conclusions: The study has shown that the leaf extract was able to synthesis Ag nanoparticles with antibacterial activity against Escherichia coli and Staphylococcus epidermis

Growth of flower-like Brushite structures on magnesium substrates and their subsequent low temperature transformation to hydroxyapatite

Dicalcium phosphate dihydrate (DCPD) Brushite coatings composed of flower-like structures were formed on magnesium substrates via a straightforward chemical immersion technique in order to slow down the corrosion rate of the metallic substrates. Moreover, the synthesised DCPD coatings were also converted to hydroxyapatite (HAP) coating using a low-temperature hydrothermal process to further investigate their ability to reduce the corrosion rate of the substrates in phosphate buffer saline (PBS) and Ringer’s solutions. Degradation studies found DCPD coatings were capable of providing the most significant reduction in the corrosion rate of around 0.100 mm/yr compared to 3.828 mm/yr for the uncoated substrates soaked in Ringer’s solution at 37ºC

Synthesis of a bone like composite material derived from waste pearl oyster shells for potential bone tissue bioengineering applications

Background: Hydroxyapatite is generally considered a viable substitute for bone in a number of medical procedures such as bone repair, bone augmentation and coating metal implants. Unfortunately, hydroxyapatite has poor mechanical properties that make it unsuitable for many load bearing applications. Methods: In the present work various grades of finely crushed Pinctada maxima (pearl oyster shell) were combined with a nanometer scale hydroxyapatite powder to form novel composite materials. A comparative study was made between the various powder based composites synthesized. The crystalline structure and morphology of the various powder based composites were investigated using X-ray diffraction and field emission scanning electron microscopy. The composite materials were also evaluated and characterized. Results: Manufactured hydroxyapatite powders were composed of crystalline spherical/granular particles with a mean size of 30 nm. Also produced were hydroxyapatite and finely crushed calcium carbonate from Pinctada maxima (pearl oyster shell) powder mixtures. Hydroxyapatite coatings produced on Pinctada maxima nacre substrates were investigated and their surface characteristics reported. Conclusions: Pinctada maxima nacre pre-treated with sodium hypo chlorate before hydroxyapatite deposition produced a superior coating and could be used for bone tissue engineering. But further in vitro and in vivo studies are needed to validate the biocompatibility and long term stability of this composite coating