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Hydrilla is an invasive aquatic plant that has rapidly spread through many inland water bodies across the globe by outcompeting native aquatic plants. The negative impacts of hydrilla invasion have become a concern for water resource management authorities, power companies, and environmental scientists. The early detection of hydrilla infestation is very important to reduce the costs associated with control and removal efforts of this invasive species. Therefore, in this study, we aimed to develop a tool for rapid, frequent, and large-scale monitoring and predicting spatial extent of hydrilla habitat. This was achieved by integrating in situ and Landsat 8 Operational Land Imager satellite data for Lake J. Strom Thurmond, the largest US Army Corps of Engineers lake east of the Mississippi River, located on the border of Georgia and South Carolina border. The predictive model for presence of hydrilla incorporated radiometric and physical measurements, including remote-sensing reflectance, Secchi disk depth (SDD), light-attenuation coefficient (Kd), maximum depth of colonization (Zc), and percentage of light available through the water column (PLW). The model-predicted ideal habitat for hydrilla featured high SDD, Zc, and PLW values, low values of Kd. Monthly analyses based on satellite images showed that hydrilla starts growing in April, reaches peak coverage around October, begins retreating in the following months, and disappears in February. Analysis of physical and meteorological factors (i.e., water temperature, surface runoff, net inflow, precipitation) revealed that these parameters are closely associated with hydrilla extent. Management agencies can use these results not only to plan removal efforts but also to evaluate and adapt their current mitigation efforts.
Early finished lambs are able to command a higher premium at slaughter. Improvement in growth rate can increase the profitability of the enterprise. The use of yeast cell wall preparations, in particular the mannan oligosaccharide portion, has been shown to improve intestinal tract health and thus growth rates in other species (Uni & Smirnov, 2006; Rosen, 2006). Farm studies have suggested that the inclusion of mannan oligosaccharides have the greatest effect in young animals prior to weaning. The aim of the current study was to determine the effect of feeding a mannan oligosaccharide on the growth rates of early finished lambs reared indoors on a commercial farm from birth until weaning.
Zinc is an essential trace element necessary for the activity of numerous enzymes. Supplemental zinc is considered normal for ruminant livestock to ensure that requirements are met. Although zinc deficiency is not generally recognised in the UK, there is considerable evidence that this supplemental zinc is beneficial. The aim of this study was to investigate the effect of partially replacing zinc oxide with a zinc proteinate in the diet of ewes in late pregnancy and lactation on performance and health of ewes and lambs.
There are many rationing models used commercially for evaluating diets fed to dairy cows. A new model – BioParaMilk – uses a unique protein degradation model to determine microbial protein synthesis, based upon the in vitro gas production technique (IVGPT). Optigen®, a slow release, blended, non-protein nitrogen source, can partially replace soyabean meal (SBM) in a dairy diet. The partial replacement of soyabean meal and rapeseed meal with Optigen® has been shown to increase fibre digestion and may improve volatile fatty acid (VFA) and microbial nitrogen (N) flow in the rumen (Sinclair et al., 2008). The purpose of this study was to evaluate the protein degradation curve from Optigen® compared to SBM for use in this new model, using IVGPT.
Tidal flexure in ice shelf grounding zones has been used extensively in the past to determine grounding line position and ice properties. Although the rheology of ice is viscoelastic at tidal loading frequencies, most modelling studies have assumed some form of linear elastic beam approximation to match observed flexure profiles. Here we use density, radar and DInSAR measurements in combination with full-Stokes viscoelastic modelling to investigate a range of additional controls on the flexure of the Southern McMurdo Ice Shelf. We find that inclusion of observed basal crevasses and density dependent ice stiffness can greatly alter the flexure profile and yet fitting a simple elastic beam model to that profile will still produce an excellent fit. Estimates of the effective Young's modulus derived by fitting flexure profiles are shown to vary by over 200% depending on whether these factors are included, even when the local thickness is well constrained. Conversely, estimates of the grounding line position are relatively insensitive to these considerations for the case of a steep bed slope in our study region. By fitting tidal amplitudes only, and ignoring phase information, elastic beam theory can provide a good fit to observations in a wide variety of situations. This should, however, not be taken as an indication that the underlying rheological assumptions are correct.
Orthopedic devices improve the quality of life of millions of people, and show up on radiographs and cross-sectional imaging studies daily. This text will familiarise radiologists with the indications, applications, potential complications, and radiologic evaluation of many medical devices. The book offers a complete discussion of fracture fixation, joint arthroplasty, and orthopedic apparatus of the neck and spine, including the cervical, thoracic, and lumbar spine. It also provides detailed overviews of devices used for common dental disease, covers the general principles applicable to complications of orthopedic devices, foreign body ingestions, insertions and injuries, and details quality assurance issues concerning the manufacture and distribution of devices. Featuring a large gallery of apparatus for reference, an extensive glossary of terms and a list of manufacturers, Radiologic Guide to Orthopedic Devices is an essential resource for radiologists, orthopedists and emergency medicine physicians. Regular updates to the topics covered will be available on http://www.medapparatus.com.
Introduction: Active substance use and unstable housing are both associated with increased emergency department (ED) utilization. This study examined ED health care costs among a cohort of substance using and/or homeless adults following an index ED visit, relative to a control ED population. Methods: Consecutive patients presenting to an inner-city ED between August 2010 and November 2011 who reported unstable housing and/or who had a chief presenting complaint related to acute or chronic substance use were evaluated. Controls were enrolled in a 1:4 ratio. Participants’ health care utilization was tracked via electronic medical record for six months after the index ED visit. Costing data across all EDs in the region was obtained from Alberta Health Services and calculated to include physician billing and the cost of an ED visit excluding investigations. The cost impact of ED utilization was estimated by multiplying the derived ED cost per visit by the median number of visits with interquartile ranges (IQR) for each group during follow up. Proportions were compared using non-parametric tests. Results: From 4679 patients screened, 209 patients were enrolled (41 controls, 46 substance using, 91 unstably housed, 31 both unstably housed and substance using (UHS)). Median costs (IQR) per group over the six-month period were $0 ($0-$345.42) for control, $345.42 ($0-$1139.89) for substance using, $345.42 ($0-$1381.68) for unstably housed and $1381.68 ($690.84-$4248.67) for unstably housed and substance using patients (p<0.05). Conclusion: The intensity of excess ED costs was greatest in patients who were both unstably housed and presenting with a chief complaint related to substance use. This group had a significantly larger impact on health care expenditure relative to ED users who were not unstably housed or who presented with a substance use related complaint. Further research into how care or connection to community resources in the ED can reduce these costs is warranted.