Examining Rhodium Catalyst complexes for Use with Conducting Polymers Designed for Fuel Cells in Preparing Biosensors

Biosensing devices are important because they can detect, record, and transmit information regarding the presence of, or physiological changes in, different chemical or biological materials in the environment. The goal of this research is to prepare a biosensing device that is effective, quick, and low cost. This is done by examining which chemicals will work best when placed in a biosensor. The first study involved experimenting on a rhodium catalyst complexed with ligands such as bipyridine and imidazole. The rhodium catalyst is important because it is reduced from RhIII to RhI, forms a hydride by reaction with water and releases the hydride to react with nicotinamide adenine dinucleotide (NAD+) to selectively produce 1,4-NADH, the reduced form of NAD+. The second study looked at different types of ketones and enzymes for the enzyme-substrate reaction converting a ketone into an alcohol. Preliminary results showed that the rhodium complexed with bipyridine was able to carry out all the reactions, while the rhodium complexed with imidazole was not able to produce and release hydrides. In addition, the most effective ketone to use is benzylacetone with the enzyme alcohol dehydrogenase from baker’s yeast. Future work includes experimenting with bis-imidazole, which mimics the structure of bipyridine to see if it has the capability to reduce and if the reduction rate is comparable to the bipyridine complex. Once all testing is completed, the fastest catalysts will be combined with polymer membranes designed for fuel cells to prepare biosensing devices that can be used in a variety of applications including ones in the medical and environmental fields

Assessment of the structure and variability of Weddell Sea water masses in distinct ocean reanalysis products

We assessed and evaluated the performance of five ocean reanalysis products in reproducing essential hydrographic properties and their associated temporal variability for the Weddell Sea, Antarctica. The products used in this assessment were ECMWF ORAS4 (European Centre for Medium-Range Weather Forecasts Ocean Reanalysis System 4), CFSR (Climate Forecast System Reanalysis), MyOcean UR025.4 (University of Reading), ECCO2 (Estimating the Circulation and Climate of the Ocean, Phase II) and SODA (Simple Ocean Data Assimilation). The present study focuses on the Weddell Sea deep layer, which is composed of the following three main water masses: Warm Deep Water (WDW), Weddell Sea Deep Water (WSDW) and Weddell Sea Bottom Water (WSBW). The MyOcean UR025.4 product provided the most accurate representation of the structure and thermohaline properties of the Weddell Sea water masses when compared with observations. All the ocean reanalysis products analyzed exhibited limited capabilities in representing the surface water masses in the Weddell Sea. The CFSR and ECCO2 products were not able to represent deep water masses with a neutral density ? 28.40 kg m?3, which was considered the WSBW's upper limit throughout the simulation period. The expected WDW warming was only reproduced by the SODA product, whereas the ECCO2 product was able to represent the trends in the WSDW's hydrographic properties. All the assessed ocean reanalyses were able to represent the decrease in the WSBW's density, except the SODA product in the inner Weddell Sea. Improvements in parameterization may have as much impact on the reanalyses assessed as improvements in horizontal resolution primarily because the Southern Ocean lacks in situ data, and the data that are currently available are summer-biased. The choice of the reanalysis product should be made carefully, taking into account the performance, the parameters of interest, and the type of physical processes to be evaluated

Epidemiology of ankle sprains and chronic ankle instability

Objective: To provide a focused overview of the existing literature on the epidemiology of acute ankle sprains (lateral, medial, and high/syndesmotic) with an emphasis on incidence studies from the United States. In addition, we provide a brief overview of chronic ankle instability (CAI), posttraumatic osteoarthritis, and injury prevention to contribute to our understanding of the epidemiology of these injuries and the current state of the science on ankle sprains and ankle instability in sports medicine. Background: Acute ankle sprains are one of the most common musculoskeletal injuries, with a high incidence among physically active individuals. Additionally, acute ankle sprains have a high recurrence rate, which is associated with the development of CAI. Understanding the epidemiology of these injuries is important for improving patients’ musculoskeletal health and reducing the burden of lower limb musculoskeletal conditions. Description: Acute ankle-sprain incidence rates are summarized among the general population, as well as among physically active populations, including organized athletics and military personnel, with a focus on incidence in the United States. The link between a prior ankle sprain and a future acute ankle sprain is described. We also discuss the association between the incident ankle sprain and adverse, long-term outcomes such as CAI and posttraumatic osteoarthritis. Finally, we summarize injury-prevention successes and future directions for research and prevention. Clinical Applications: This information is useful for health care providers to understand the expected incidence rates of acute ankle sprains, be aware of the association between ankle sprains and negative short- and long-term outcomes, and be familiar with existing injury-prevention programs

Economic and livestock health impacts of birds on dairies: Evidence from a survey of Washington dairy operators

The survey described in this research paper aimed to investigate the economic and health impacts of birds on dairies. Birds are common pests on dairies, consuming and contaminating feed intended for cattle. As a result, dairy operators experience increased feed costs and increased pathogen and disease risk. We surveyed dairy operators attending the 2017 Washington Dairy Conference to examine the impact of birds on dairies in Washington State. Dairy operators reported feed losses valued at $55 per cow resulting in annual losses totaling$5.5 million in the Western region of the state and $9.2 million in the Eastern region of the state. Shooting was the most commonly used bird management method and European starlings (Sternus vulgaris) were the most frequently implicated species statewide. Bird abundance greater than 10,000 birds per day was associated with larger herd size and with self-reported presence of Johne’s disease and Salmonella

The relativistic precession of the orbits

The relativistic precession can be quickly inferred from the nonlinear polar orbit equation without actually solving it.Comment: Accepted for publication in Astrophysics & Space Scienc

Pioneering a novel synthetic heart valve

Introduction Cardiac valve disease results in a disruption to haemodynamics, with frequent progression to end stage heart failure if left untreated. Valve replacement restores function to the heart and thus represents a lifesaving procedure [1]. Synthetic heart valves combine the durability of mechanical valves with the haemocompatibility of bioprosthetic valves. However, challenges including calcification, leaflet tearing and poor surface morphology mean that they have yet to reach clinical translation. The design of the Wheatley Heart Valve (WHV, Figure 1a) differs considerably from existing polymeric heart valves as it can be mathematically defined through a series of contiguous circles [2]. This permits changes to the design to be parametrically investigated (by changing the radius of the free edge and leaflet height) and facilitates a sinus washout through helical flow as blood exists the aorta. Computational mathematical modelling, in vitro testing and advanced surface characterisation technologies are investigated to advance the WHV closer towards clinical translation. Methods The leaflets were fabricated from solvent cast films of CarbothaneTM, an aliphatic polyurethane elastomer, which are then laser cut into leaflets. Sintered titanium stents were produced through additive manufacturing and the leaflets attached at the base and commissures via mechanical fixtures to form a tri-leaflet valve having both a concave and convex free edge. Flow performance through the valve was investigated through both steady (Ansys Fluent) and time-dependent (LS-Dyna) computational fluid modelling. Experimental tests were conducted through use of an in-house built pulse duplicator, based on a 3-element Windkessel model and a durability tester (ViVitro HiCycle). Pressure readings were taken using a Biopac MP36 System. Results & Discussion Our steady state computational analysis confirmed that that the unique curvature of the WHV facilitates helical blood flow downstream of the valve (Figure 1(b)). Work is ongoing to optimise the leaflet properties of the WHV by conducting an iterative process between our mathematical models and our in vitro bench tests. Investigations are also underway to enhancing the surface properties with Diamond Like Carbon (DLC) coatings using an ECR (electron cyclotron resonance) ion beam deposition facility. DLC are a class of amorphous carbons having similar properties to diamond, containing a mixture of both sp2 and sp3 carbon-carbon interatomic bonds. They have gained interest in medical applications due to their chemical inertness, and similar platelet absorption to LTI carbon (currently used as coatings in mechanical valves). Early investigations have demonstrated good adhesion of DLC films having a thickness of approximately 100 nm on our polymer leaflets. Further work will explore their biocompatibility and mechanical characteristics to enhance the performance of the WHV. Conclusion The WHV is a novel synthetic heart valve with the potential to facilitate a washout of blood flow as the leaflets close. Testing is ongoing in accordance with ISO 5840-1 and -2 to advance the WHV towards clinical translation

Supporting knowledge transfer in web-based managed IT support

Purpose &ndash; The purpose of this paper is to highlight the importance and complexities of the knowledge transfer process in the provision of effective managed after-sales IT support, when the web is used for service delivery.Design/methodology/approach &ndash; The paper features an interpretive case study of a multinational Managed Service Provider (MSP) and a focus group of representatives from five comparable MSPs.Findings &ndash; The paper finds that MSPs that use web-based channels for the provision of after-sales IT support services need to address a range of important social and organisational issues in order to realise cost and efficiency-based benefits.Research limitations/implications &ndash; The paper provides a four stage processual model of knowledge transfer in the provision of web-based managed after-sales IT support services. The barriers and enablers of knowledge transfer at each stage are identified. The paper adopts a MSP perspective and suggests that further research from the customer perspective is required.Practical implications &ndash; The paper highlights some important social and organisational enablers and barriers, which will guide MSPs when providing managed after-sales IT support using webbased channels.Originality/value &ndash; The paper provides the first staged model of inter-organisational knowledge transfer in a complex multi-organisational and multi-channel web-based context.<br /

New Insights into White-Light Flare Emission from Radiative-Hydrodynamic Modeling of a Chromospheric Condensation

(abridged) The heating mechanism at high densities during M dwarf flares is poorly understood. Spectra of M dwarf flares in the optical and near-ultraviolet wavelength regimes have revealed three continuum components during the impulsive phase: 1) an energetically dominant blackbody component with a color temperature of T $\sim$ 10,000 K in the blue-optical, 2) a smaller amount of Balmer continuum emission in the near-ultraviolet at lambda $<$ 3646 Angstroms and 3) an apparent pseudo-continuum of blended high-order Balmer lines. These properties are not reproduced by models that employ a typical "solar-type" flare heating level in nonthermal electrons, and therefore our understanding of these spectra is limited to a phenomenological interpretation. We present a new 1D radiative-hydrodynamic model of an M dwarf flare from precipitating nonthermal electrons with a large energy flux of $10^{13}$ erg cm$^{-2}$ s$^{-1}$. The simulation produces bright continuum emission from a dense, hot chromospheric condensation. For the first time, the observed color temperature and Balmer jump ratio are produced self-consistently in a radiative-hydrodynamic flare model. We find that a T $\sim$ 10,000 K blackbody-like continuum component and a small Balmer jump ratio result from optically thick Balmer and Paschen recombination radiation, and thus the properties of the flux spectrum are caused by blue light escaping over a larger physical depth range compared to red and near-ultraviolet light. To model the near-ultraviolet pseudo-continuum previously attributed to overlapping Balmer lines, we include the extra Balmer continuum opacity from Landau-Zener transitions that result from merged, high order energy levels of hydrogen in a dense, partially ionized atmosphere. This reveals a new diagnostic of ambient charge density in the densest regions of the atmosphere that are heated during dMe and solar flares.Comment: 50 pages, 2 tables, 13 figures. Accepted for publication in the Solar Physics Topical Issue, "Solar and Stellar Flares". Version 2 (June 22, 2015): updated to include comments by Guest Editor. The final publication is available at Springer via http://dx.doi.org/10.1007/s11207-015-0708-

The future for follow-up of gynaecological cancer in Europe. Summary of available data and overview of ongoing trials

After completing treatment, most patients follow a pre-determined schedule of regular hospital outpatient appointments, which includes clinical examinations, consultations and routine tests. After several years of surveillance, patients are transferred back to primary care. However, there is limited evidence to support the effectiveness and efficiency of this approach. This paper examines the current rationale and evidence base for hospital-based follow-up after treatment for gynaecological cancer. We investigate what alternative models of care have been formally evaluated and what research is currently in progress in Europe, in order to make tentative recommendations for a model of follow-up. The evidence base for traditional hospital based follow-up is limited. Alternative models have been reported for other cancer types but there are few evaluations of alternative approaches for gynaecological cancers. We identified five ongoing European studies; four were focused on endometrial cancer patients and one feasibility study included all gynaecological cancers. Only one study had reached the reporting stage. Alternative models included nurse-led telephone follow-up and comparisons of more intensive versus less intensive regimes. Outcomes included survival, quality of life, psychological morbidity, patient satisfaction and cost effectiveness of service. More work is needed on alternative strategies for all gynaecological cancer types. New models will be likely to include risk stratification with early discharge from secondary care for early stage disease with fast track access to specialist services for suspected cancer recurrence or other problems