A geochemical evaluation of water quality along the course of the Huron River, Northern Ohio

The principal source of water in the Huron River is groundwater. However, other water types also enter the river at various localities along the course of the river. The water in the Huron River consists of a mixture of two groundwater components as well as waters from other sources whose entry into the river changes the chemical composition of the water of the Huron River along its course. Mixing and dilution occur along the entire course of the river. Initially the two groundwater components mix to form water reflecting both components. In addition, various contaminants enter the river and mix with the pristine water already in the river channel. Meteoric water serves as a diluting agent which decreases the concentrations of the elements dissolved in the water. Contaminants enter the river in the form of sewage effluent and industrial waste discharged either directly or via tributary streams. How and to what extent these influxes of water affect the chemical composition of the river can be determined through the interpretation of chemical analyses of water along the river's course. By treating the water as a series of mixtures, we can determine the natural composition of the water without the effects of contamination.No embarg

An incubatable direct current stimulation system for in vitro studies of Mammalian cells.

The purpose of this study was to provide a simplified alternative technology and format for direct current stimulation of mammalian cells. An incubatable reusable stimulator was developed that effectively delivers a regulated current and does not require constant monitoring

Intermittent Bolus versus Continuous Infusion of Propofol for Deep Sedation during ABR/Nuclear Medicine Studies

Objective  A comparison of intermittent bolus (IB) versus continuous infusion of propofol for deep sedation. Material and Methods  A retrospective review of patients sedated for Auditory Brainstem Response (ABR)/nuclear medicine studies between September 2008 and February 2015. A ketamine bolus (0.5 mg/kg 20 kg) followed by propofol bolus of 1 mg/kg over 2 minutes. In the IB group, maintenance of deep sedation was with incremental bolus of 10 to 20 mg of propofol. In continuous infusion group (CG), maintenance was with a continuous infusion of 83 mcg/kg/min of propofol. Results  Of the 326 cases completed, 181 were in CG group and 145 were in IB group. There were no statistical differences in patient's age, weight, and American Society of Anesthesiologist (ASA) classification. The cardiovascular and respiratory parameters in the two groups were not different statistically. Mean total propofol dose was higher in CG group versus IB group (CG 7.6 mg ± 3.6 mg, IB 6.5 mg ± 3.6 mg; p  = 0.008). Procedure time in CG group was longer by 8 minutes compared with IB group (CG 49.8 min ± 25.4 min versus 42.3 min ± 19.2 min; p  = .003). CG group has both shorter recovery time (CG 8.1 min ± 4.7 min versus IB 10.0 min ± 8.5 min; p  = 0.01) and discharge time. Conclusion  Satisfactory sedation and completion of the procedure was accomplished with both sedation protocols

Effect of oxidative treatment on the secondary structure of decoloured bloodmeal

Bloodmeal can be decoloured using peracetic acid resulting in a material with a pale-yellow colour which only needs sodium dodecyl sulphate, water and triethylene glycol to extrude into a semi-transparent bioplastic. Fourier-transform infrared (FTIR) spectroscopy using Synchrotron light was used to investigate the effect of peracetic acid treatment at various concentrations on the spatial distribution of secondary structures within particles of bloodmeal. Oxidation caused aggregation of helical structures into sheets and acetic acid suppressed sheet formation. Decolouring with peracetic acid led to particles with a higher degree of disorder at the outer edges and higher proportions of ordered structures at the core, consistent with the expected diffusion controlled heterogeneous phase decolouring reaction. The degradation of stabilizing intra- and intermolecular interactions and the presence of acetate ions results in increased chain mobility and greater amorphous content in the material, as evidenced by reduction in Tg and greater enthalpy of relaxation with increasing PAA concentration

Responses of salmonids to habitat changes

Streams in western North America provide spawning and rearing habitats for several species of salmon and trout that are of substantial economic importance in the region. Timber that grows on lands through which these streams flow is also economically important, and its harvest can substantially change habitat conditions and aquatic production in salmonid streams. Undisturbed forests, the streams that flow through them, and the salmonid communities in these streams have intrinsic scientific, genetic, and cultural values in addition to their economic importance. The complex relations between salmonids and their physical environment, and the changes in these relations brought about by timber harvest, have been investigated extensively (see the bibliography by Macdonald et al. 1988). However, in spite of considerable evidence of profound changes in channel morphology and in light, temperature, and flow regimes associated with timber harvests, much uncertainty exists about the responses of salmonids to these changes

Flight test techniques for the X-29A aircraft

The X-29A advanced technology demonstrator is a single-seat, single-engine aircraft with a forward-swept wing. The aircraft incorporates many advanced technologies being considered for this country's next generation of aircraft. This unusual aircraft configuration, which had never been flown before, required a precise approach to flight envelope expansion. This paper describes the real-time analysis methods and flight test techniques used during the envelope expansion of the x-29A aircraft, including new and innovative approaches

Perceptions of the learning environment in higher specialist training of doctors: implications for recruitment and retention.

INTRODUCTION: Career choice, sense of professional identity and career behaviour are influenced, subject to change and capable of development through interaction with the learning environment. In this paper workplace learning discourses are used to frame ongoing concerns associated with higher specialist training. Data from the first stage of a multimethods investigation into recruitment into and retention in specialties in the West Midlands is used to consider some possible effects of the specialist learning environment on recruitment and retention. METHODS: The aim of the study was to identify issues, through interviews with 6 consultants and questionnaires completed by specialist registrars from specialties representing a range of recruitment levels. These would inform subsequent study of attributes and dispositions relevant to specialist practice and recruitment. The data were analysed using NVivo software for qualitative data management. RESULTS: Participants' perceptions are presented as bipolar dimensions, associated with: curriculum structure, learning relationships, assessment of learning, and learning climate. They demonstrate ongoing struggle between different models of workplace learning. CONCLUSION: Changes in the postgraduate education of doctors seem set to continue well into the future. How these are reflected in the balance between workplace learning models, and how they influence doctors' sense of identity as specialists suggests a useful basis for examination of career satisfaction and recruitment to specialties

Fish and macroinvertebrates in lowland drainage canals with and without grass carp

Diploid grass carp (Ctenopharyngodon idella L.) were introduced to a lowland Waikato drainage canal at an initial density of 40-80 kg ha -1(83-167 fish ha -1) to control aquatic macrophytes and improve water flow. A near-by canal was left without grass carp to act as an untreated control. After 7 months, macrophytes occupied 17% of the water column in the treated canal compared to 78% in the untreated canal. Fish and macroinvertebrates in both canals were examined before and after the release of grass carp by sampling with replacement by fyke netting on seven occasions. Brown bullhead catfish (Ameiurus nebulosus (Lesueur)) and shortfinned eels (Anguilla australis Richardson) comprised most of the resident fish biomass in both canals; however, before grass carp stocking, eels were more abundant than catfish in the treated canal. There was no change in the abundance of resident fish after stocking, but young-of-the-year catfish had greater mortality and grew faster in the treated canal than in the untreated canal. Macroinvertebrates were primarily associated with aquatic macrophytes. Grass carp reduced aquatic macrophyte abundance in the treated canal by about 80%, which by inference reduced the abundance of associated macroinvertebrates, but there was no observed impact of grass carp stocking on the resident fish assemblage. We examined the relationship between head width and fish length, and from this determined that 70% of the grass carp could have escaped through the downstream retention screen. Despite this possibility, grass carp remained in the canal and effectively controlled aquatic macrophytes for 18 months