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Authors = John Hart

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Open AccessArticle Evaluation of Visual-Evoked Cerebral Metabolic Rate of Oxygen as a Diagnostic Marker in Multiple Sclerosis
Brain Sci. 2017, 7(6), 64; doi:10.3390/brainsci7060064
Received: 31 March 2017 / Revised: 3 June 2017 / Accepted: 5 June 2017 / Published: 11 June 2017
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Abstract
A multiple sclerosis (MS) diagnosis often relies upon clinical presentation and qualitative analysis of standard, magnetic resonance brain images. However, the accuracy of MS diagnoses can be improved by utilizing advanced brain imaging methods. We assessed the accuracy of a new neuroimaging marker,
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A multiple sclerosis (MS) diagnosis often relies upon clinical presentation and qualitative analysis of standard, magnetic resonance brain images. However, the accuracy of MS diagnoses can be improved by utilizing advanced brain imaging methods. We assessed the accuracy of a new neuroimaging marker, visual-evoked cerebral metabolic rate of oxygen (veCMRO2), in classifying MS patients and closely age- and sex-matched healthy control (HC) participants. MS patients and HCs underwent calibrated functional magnetic resonance imaging (cfMRI) during a visual stimulation task, diffusion tensor imaging, T1- and T2-weighted imaging, neuropsychological testing, and completed self-report questionnaires. Using resampling techniques to avoid bias and increase the generalizability of the results, we assessed the accuracy of veCMRO2 in classifying MS patients and HCs. veCMRO2 classification accuracy was also examined in the context of other evoked visuofunctional measures, white matter microstructural integrity, lesion-based measures from T2-weighted imaging, atrophy measures from T1-weighted imaging, neuropsychological tests, and self-report assays of clinical symptomology. veCMRO2 was significant and within the top 16% of measures (43 total) in classifying MS status using both within-sample (82% accuracy) and out-of-sample (77% accuracy) observations. High accuracy of veCMRO2 in classifying MS demonstrated an encouraging first step toward establishing veCMRO2 as a neurodiagnostic marker of MS. Full article
(This article belongs to the Special Issue Pathophysiology and Imaging Diagnosis of Demyelinating Disorders)
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Open AccessReview Recent Advances in the Fabrication and Application of Screen-Printed Electrochemical (Bio)Sensors Based on Carbon Materials for Biomedical, Agri-Food and Environmental Analyses
Biosensors 2016, 6(4), 50; doi:10.3390/bios6040050
Received: 2 August 2016 / Revised: 7 September 2016 / Accepted: 19 September 2016 / Published: 28 September 2016
Cited by 4 | Viewed by 1340 | PDF Full-text (2476 KB) | HTML Full-text | XML Full-text
Abstract
This review describes recent advances in the fabrication of electrochemical (bio)sensors based on screen-printing technology involving carbon materials and their application in biomedical, agri-food and environmental analyses. It will focus on the various strategies employed in the fabrication of screen-printed (bio)sensors, together with
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This review describes recent advances in the fabrication of electrochemical (bio)sensors based on screen-printing technology involving carbon materials and their application in biomedical, agri-food and environmental analyses. It will focus on the various strategies employed in the fabrication of screen-printed (bio)sensors, together with their performance characteristics; the application of these devices for the measurement of selected naturally occurring biomolecules, environmental pollutants and toxins will be discussed. Full article
(This article belongs to the Special Issue Screen-Printed Electrodes and Sensors)
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Open AccessCommunication Air Temperature and Death Rates in the Continental U.S., 1968–2013
Climate 2015, 3(2), 435-441; doi:10.3390/cli3020435
Received: 21 May 2015 / Revised: 12 June 2015 / Accepted: 15 June 2015 / Published: 18 June 2015
Cited by 2 | Viewed by 1679 | PDF Full-text (91 KB) | HTML Full-text | XML Full-text
Abstract
A previous test of global warming theory, on a local level, for Texas revealed inverse correlations between air temperature and death rates. The present study expands the test field to the continental U.S. Using an ecological design, mean daily maximum air temperature (“temperature”)
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A previous test of global warming theory, on a local level, for Texas revealed inverse correlations between air temperature and death rates. The present study expands the test field to the continental U.S. Using an ecological design, mean daily maximum air temperature (“temperature”) in the 48 contiguous states plus the District of Columbia by year from 1968–2013 was compared to age-adjusted all-cause mortality (“deaths”) in these same jurisdictions for the same years using Pearson correlation (n = 46 years). The comparison was made for three race categories, white, black, and all races, where each category included all ages and both genders. There was 5.0 degree F range for the years studied (62.7–67.7 degrees F). Correlations were moderate strength, inverse, and statistically significant, as follows. Whites: r = −0.576, p < 0.0001; Blacks: r = −0.556, p = 0.0001; and all races: r = −0.577, p < 0.0001. These correlations are consistent with the Texas study, both of which indicated that warmer years tended to correlate with decreased death rates. A limitation to this research is its (ecological) design, but is an initial step towards further investigation. Full article
(This article belongs to the Special Issue Climate Impacts on Health)
Open AccessArticle Fabrication and Evaluation of a Micro(Bio)Sensor Array Chip for Multiple Parallel Measurements of Important Cell Biomarkers
Sensors 2014, 14(11), 20519-20532; doi:10.3390/s141120519
Received: 21 July 2014 / Revised: 20 September 2014 / Accepted: 21 October 2014 / Published: 30 October 2014
Cited by 6 | Viewed by 1857 | PDF Full-text (2122 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
This report describes the design and development of an integrated electrochemical cell culture monitoring system, based on enzyme-biosensors and chemical sensors, for monitoring indicators of mammalian cell metabolic status. MEMS technology was used to fabricate a microwell-format silicon platform including a thermometer, onto
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This report describes the design and development of an integrated electrochemical cell culture monitoring system, based on enzyme-biosensors and chemical sensors, for monitoring indicators of mammalian cell metabolic status. MEMS technology was used to fabricate a microwell-format silicon platform including a thermometer, onto which chemical sensors (pH, O2) and screen-printed biosensors (glucose, lactate), were grafted/deposited. Microwells were formed over the fabricated sensors to give 5-well sensor strips which were interfaced with a multipotentiostat via a bespoke connector box interface. The operation of each sensor/biosensor type was examined individually, and examples of operating devices in five microwells in parallel, in either potentiometric (pH sensing) or amperometric (glucose biosensing) mode are shown. The performance characteristics of the sensors/biosensors indicate that the system could readily be applied to cell culture/toxicity studies. Full article
(This article belongs to the Special Issue Printed Sensors)
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Open AccessArticle Long-Term Soil Productivity in Christmas Tree Farms of Oregon and Washington: A Comparative Analysis between First- and Multi-Rotation Plantations
Forests 2014, 5(10), 2581-2593; doi:10.3390/f5102581
Received: 29 August 2014 / Revised: 17 October 2014 / Accepted: 21 October 2014 / Published: 23 October 2014
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Abstract
Christmas tree production removes organic matter and associated nutrients from a site and can change soil physical properties, reduce mycorrhizal populations, and result in pesticide over-use/accumulation. These impacts have been implicated in potential field productivity declines. Assessing Christmas tree productivity is complicated by
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Christmas tree production removes organic matter and associated nutrients from a site and can change soil physical properties, reduce mycorrhizal populations, and result in pesticide over-use/accumulation. These impacts have been implicated in potential field productivity declines. Assessing Christmas tree productivity is complicated by genetics, management, and market forces. We approached the perceived or possible productivity decline by examining soil properties on 22 pairs of sites. Each pair was comprised of an early rotation and late rotation plot with 1 and 3 or more rotations of Christmas trees, respectively. All sites were located on commercial Christmas tree plantations from the major production areas in Washington and Oregon. Chemical properties assessed to 45cm included pH, total C and N, and extractable P, K, Ca, and Mg. Soil physical properties assessed included aggregate stability and soil resistance. In general, we found little impact on soil resources that would impact long term production of Christmas trees. These impacts may have been mitigated by farmers following extension service recommendations. Nitrogen, K, and Ca appeared to be primarily affected by harvesting, but replacement by fertilizer application was probably adequate. Full article

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