Biosensor development at the University of Utah

Journal ArticleInterest in biosensors has increased rapidly in the past few years due to the many potential advantages of these devices, such as small size, speed of response, and specificity 111. The term "biosensor" in the broad sense describes any device or apparatus which detects biological signals for the purpose of diagnosis, monitoring, imaging or sensing the state of the biological organism. This includes the more narrow definition-that of a biosensor as a continuous, reversible monitor of some physiological parameter

Climate control of terrestrial carbon exchange across biomes and continents

Peer reviewe

Evaluation of methods to measure acoustic transfer functions in cavitation tunnels

The interest for cavitation noise studies and prediction is increasing in the field of naval architecture, mainly because of attention to environmental issues. Model scale tests in cavitation tunnels are commonly considered as one of the most effective tools for cavitation noise studies. However, despite being carried out since long time, model scale experiments still present many challenges. These are mainly related to scale effects on propeller hydrodynamics, cavitation behaviour and scale effects on noise generation and propagation. Besides these phenomena the effect of the confined environment in which tests are carried out may be of great importance. In present work, an acoustic characterization of the SSPA large cavitation tunnel section #3 is presented, with the aim to obtain suitable transfer functions in order to take into account (at least partially) this phenomenon. The acoustic characterisation is performed considering two different underwater transducers and different signals and post processing techniques. The obtained transfer functions are shown and discussed in order to analyse advantages and shortcomings of the different procedures and to generally identify main problems related to this kind of activity

An adaptive filter-based method for robust, automatic detection and frequency estimation of whistles

This paper proposes an adaptive filter-based method for detection and frequency estimation of whistle calls, such as the calls of birds and marine mammals, which are typically analyzed in the time-frequency domain using a spectrogram. The approach taken here is based on adaptive notch filtering, which is an established technique for frequency tracking. For application to automatic whistle processing, methods for detection and improved frequency tracking through frequency crossings as well as interfering transients are developed and coupled to the frequency tracker. Background noise estimation and compensation is accomplished using order statistics and pre-whitening. Using simulated signals as well as recorded calls of marine mammals and a human whistled speech utterance, it is shown that the proposed method can detect more simultaneous whistles than two competing spectrogram-based methods while not reporting any false alarms on the example datasets. In one example, it extracts complete 1.4 and 1.8 s bottlenose dolphin whistles successfully through frequency crossings. The method performs detection and estimates frequency tracks even at high sweep rates. The algorithm is also shown to be effective on human whistled utterance

Older drivers: On-road and off-road test results

Eighty-five volunteer drivers, 65–85 years old, without cognitive impairments impacting on their driving were examined, in order to investigate driving errors characteristic for older drivers. In addition, any relationships between cognitive off-road and on-road tests results, the latter being the gold standard, were identified. Performance measurements included Trail Making Test (TMT), Nordic Stroke Driver Screening Assessment (NorSDSA), Useful Field of View (UFOV), self-rating driving performance and the two on-road protocols P-Drive and ROA. Some of the older drivers displayed questionable driving behaviour. In total, 21% of the participants failed the on-road assessment. Some of the specific errors were more serious than others. The most common driving errors embraced speed; exceeding the speed limit or not controlling the speed. Correlations with the P-Drive protocol were established for NorSDSA total score (weak), UFOV subtest 2 (weak), and UFOV subtest 3 (moderate). Correlations with the ROA protocol were established for UFOV subtest 2 (weak) and UFOV subtest 3 (weak). P-Drive and self ratings correlated weakly, whereas no correlation between self ratings and the ROA protocol was found. The results suggest that specific problems or errors seen in an older person's driving can actually be “normal driving behaviours”

The nordic stroke driver screening assessment as predictor for the outcome of an on-road test

The use of the cognitive test battery Nordic Stroke Driver Screening Assessment (NorSDSA) has increased, sometimes as a stand-alone test to evaluate fitness to drive, also for non-stroke patients such as patients suffering from cognitive deficits/dementia, approaches that may be questioned. The objective of the study was to determine whether the NorSDSA could predict an on-road test result, for large sets of stroke (n=74) and cognitive deficits/dementia participants (n=116), respectively. The percentage of correctly classified was 62% for the stroke group and 50% for the cognitive deficits/dementia group. A discriminant analysis with pass/fail on the on-road test as grouping variable could classify 62% of the stroke participants and the cognitive deficit/dementia participants. Hence, the NorSDSA could not predict the outcome of the on-road test. Therefore, NorSDSA should not be used as a stand-alone test to determine the fitness to drive of individual participants. Also, its use with participants suffering from cognitive deficits/dementia appears to be less successful than for clients with stroke. © 2010 Informa UK Ltd

Significant Changes in Metabolic Profiles after Intervention with Selenium and Coenzyme Q10 in an Elderly Population

Selenium and coenzyme Q10 (SeQ10) are important for normal cellular function. Low selenium intake leads to increased cardiovascular mortality. Intervention with these substances with healthy elderly persons over a period of four years in a double-blind, randomised placebo-controlled prospective study showed reduced cardiovascular mortality, increased cardiac function, and a lower level of NT-proBNP. Therefore, we wanted to evaluate changes in biochemical pathways as a result of the intervention with SeQ10 using metabolic profiling. From a population of 443 healthy elderly individuals that were given 200 µg selenium and 200 mg coenzyme Q10, or placebo daily for four years, we selected nine males on active intervention and nine males on placebo for metabolic profiling in the main study. To confirm the results, two validation studies (study 1 n = 60 males, study 2 n = 37 males) were conducted. Principal component analyses were used on clinical and demographic data to select representative sets of samples for analysis and to divide the samples into batches for analysis. Gas chromatography time-of-flight mass spectrometry-based metabolomics was applied. The metabolite data were evaluated using univariate and multivariate approaches, mainly T-tests and orthogonal projections to latent structures (OPLS) analyses. Out of 95 identified metabolites, 19 were significantly decreased due to the intervention after 18 months of intervention. Significant changes could be seen in the pentose phosphate, the mevalonate, the beta-oxidation and the xanthine oxidase pathways. The intervention also resulted in changes in the urea cycle, and increases in the levels of the precursors to neurotransmitters of the brain. This adds information to previous published results reporting decreased oxidative stress and inflammation. This is the first-time metabolic profiling has been applied to elucidate the mechanisms behind an intervention with SeQ10. The study is small and should be regarded as hypothesis-generating; however, the results are interesting and, therefore, further research in the area is needed.Funding Agencies|Pharma Nord Aps, Denmark; County Council of Ostergotland, Linkoping University</p