Infrared reflectance measurements of Missouri waters for water quality applications

Students supported: 2 studentsThe relative specular reflectance of laboratory solutions of 3.0 M Sulfuric Acid and 0.5 M Sodium Nitrate was measured in the 2.0 - 20-[mu]m wavelength region of the infrared. The relative specular reflectance of natural samples of (1) acid mine drainage taken from a ditch leading from the Peabody Mark Twain Mine to Hinkson Creek; (2) surface water runoff from an agricultural test plot which had received a 314 lb/acre application of nitrate fertilizer; and (3) an oil sample from the Mexico, Missouri oil release into the Salt River was measured in the same spectral region. The data was collected using a Perkin Elmer E-14 spectrophotometer and a reflectometer consisting of a Cassegrain unit which collimated the radiant flux to about 18 mrad divergence, a sample holder and a Cassegrain condenser for focusing the radiant flux, reflected by the sample, onto the entrance slit of the monochromator. The angle of incidence was 70 degrees. The index of refraction, extinction coefficient and phase difference spectrum throughout the 2-20-[mu]m wavelength region was determined for the mine drainage, fuel oil, sulfuric acid, sodium nitrate and nitrate runoff samples using the relative reflectance measurements, the optical constants of distilled water and an algorithm for Kramers-Kronig analysis. The absolute reflectance spectrum of the alluvium and loess was determined using the relative reflectance measurements, the optical constants of distilled water and the Cauchy equation for reflectance. It is very desirable to make water quality measurements remotely. However before such measurements can be taken the characteristic manner in which aqueous solutions reflect electromagnetic radiation (in the optical properties) must be known. Thus the results obtained from this research are a part of a much larger goal to determine water quality remotely.Project # A-063-MO Agreement # 14-31-0001-382

Can human cardiovascular regulation during exercise be learnt from feedback from arterial baroreceptors?

During dynamic exercise, a large fall in systemic vascular resistance occurs. Arterial pressure (AP) is, however, maintained through a combination of central command and neural activity from muscle afferents that adjust the autonomic outflow to the circulation. How these signals are calibrated to provide accurate regulation of AP remains unclear. This study tests the hypothesis that the calibration can be ‘learnt’ through feedback from the arterial baroreceptors arising over multiple trials of exercise. Eight healthy subjects undertook three different protocols in random order. The test protocol consisted of 7 days' training, when subjects were exposed on 70 occasions to 4 min of exercise (50% of maximal oxygen uptake capacity) paired with neck suction (−40 mmHg) to mimic an excessive rise in AP at the carotid baroreceptors with exercise. Two control protocols involved training with either exercise or neck suction alone. No significant changes in mean AP, diastolic AP or heart rate during normal exercise were detected following training with any protocol. However, the rise in systolic AP with exercise was attenuated by an average of 7.3 ± 2.0 mmHg (mean ± s.e.m., P < 0.01) on the first and second days following training with the test protocol, but not with either control protocol (P < 0.05 for difference between protocols, ANOVA). In conclusion, this study failed to show that mean AP during normal exercise could be reduced through prior conditioning by overstimulation of the baroreceptors during exercise. However, a reduction in systolic AP was observed that suggests the presence of some plasticity within the autonomic response, consistent with our hypothesis

Dogslife: A web-based longitudinal study of Labrador Retriever health in the UK

<p>Abstract</p> <p>Background</p> <p>Dogslife is the first large-scale internet-based longitudinal study of canine health. The study has been designed to examine how environmental and genetic factors influence the health and development of a birth cohort of UK-based pedigree Labrador Retrievers.</p> <p>Results</p> <p>In the first 12 months of the study 1,407 Kennel Club (KC) registered eligible dogs were recruited, at a mean age of 119 days of age (SD 69 days, range 3 days – 504 days). Recruitment rates varied depending upon the study team’s ability to contact owners. Where owners authorised the provision of contact details 8.4% of dogs were recruited compared to 1.3% where no direct contact was possible. The proportion of dogs recruited was higher for owners who transferred the registration of their puppy from the breeder to themselves with the KC, and for owners who were sent an e-mail or postcard requesting participation in the project. Compliance with monthly updates was highly variable. For the 280 dogs that were aged 400 days or more on the 30^th June 2011, we estimated between 39% and 45% of owners were still actively involved in the project. Initial evaluation suggests that the cohort is representative of the general population of the KC registered Labrador Retrievers eligible to enrol with the project. Clinical signs of illnesses were reported in 44.3% of Labrador Retrievers registered with Dogslife (median age of first illness 138 days), although only 44.1% of these resulted in a veterinary presentation (median age 316 days).</p> <p>Conclusions</p> <p>The web-based platform has enabled the recruitment of a representative population of KC registered Labrador Retrievers, providing the first large-scale longitudinal population-based study of dog health. The use of multiple different methods (e-mail, post and telephone) of contact with dog owners was essential to maximise recruitment and retention of the cohort.</p

MICROGEOMETRY IN LASER CUTTING

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Inverse evaluation of pressure in elastohydrodynamic point contact.

International audienc