Measurements of pernitric acid at the South Pole during ISCAT 2000

The first measurements of pernitric acid at the South Pole were performed during the second Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT 2000). Observed HO2NO2 concentrations averaged 25 pptv. Simple steady-state calculations constrained by measurements show that the lifetime of pernitric acid was largely controlled by dry deposition, with thermal decomposition becoming increasingly important at warmer temperatures. We determined that the pernitric acid equilibrium constant is less uncertain than indicated in the literature. One consequence of pernitric acid deposition to the snow surface is that it is an important sink for both NOx and HOx. Another is that the photochemistry of HO2NO2 in the Antarctic snowpack may be a NOx source in addition to nitrate photolysis. This might be one of the important differences in snow photochemistry between the South Pole and warmer polar sites

Carbon nanotubes in electrospun polyethylene oxide nanofibres: a potential route to conducting nanofibres

Polyethylene oxide solution containing multi-walled carbon nanotubes have been electrospun onto a rotating collector to produce highly aligned arrays of electrospun nanofibers ranging in diameters from (200 – 360) nanometres. The addition of a surfactant (Triton X-100)is highly effective in dispersing carbon nanotube within an aqueous solution of polyethylene oxide and the resulting mixture can be electrospun without excessive clumping to produce nanofibers containing high loadings of nanotubes; in this case up to 5% wt thereby providing an effective route to electrically conductive nanofibres

Electrospinning of food-grade nanofibres from whey protein

In this study, electrospinning has been employed to produce micro to nano scale fibres of whey protein in order to investigate their potential for use in the food industry. Initially, spinning of purewhey protein proved challenging; so in order to facilitate the spinning of freshly prepared aqueous solutions, small amounts of polyethylene oxide (as low as 1% w/w in solution) were incorporated in the spinning solutions. The electrospun composite polyethylene-oxide/whey fibres exhibited diameters in the region of 100 to 400 nm, showing the potential to build fibre bundles from this size up. Time-dependent examinations of pure whey protein aqueous solutions were conducted using rheometery and small angle neutron scattering techniques, with the results showing a substantial change in the solution properties with time and stirring; and allowing the production of fibres, albeit with large diameters,without the need for an additive. The spinability is related to the potential of thewhey protein composites to form aggregate structures, either through hydration and interaction with neighbouring proteins, or through interaction with the polyethylene oxide

Direct digital manufacturing of nanocomposites

Additive manufacturing has surged in popularity as a route to designing and preparing functional parts. Depending on the parts function, certain attributes such as high mechanical performances may be desired. We develop a route for improving the mechanical properties of polymer devices, fabricated through additive manufacturing by combining electrospinning and stereo-lithography into one automated process. This process utilises the impressive mechanical properties of carbon nanotubes by encapsulating and aligning them in electrospun fibres. Composite fibres will be incorporated into polymer resins prepared with stereo-lithography, thereby providing resins that benefit from the composite fibres properties, enhancing their overall mechanical properties

Where Does TAM Reside in the Brain? The Neural Mechanisms Underlying Technology Adoption

Toward materializing the recently identified potential of cognitive neuroscience for IS research (Dimoka, Pavlou and Davis 2007), this paper demonstrates how functional neuroimaging tools can enhance our understanding of IS theories. Specifically, this study aims to uncover the neural mechanisms that underlie technology adoption by identifying the brain areas activated when users interact with websites that differ on their level of usefulness and ease of use. Besides localizing the neural correlates of the TAM constructs, this study helps understand their nature and dimensionality, as well as uncover hidden processes associated with intentions to use a system. The study also identifies certain technological antecedents of the TAM constructs, and shows that the brain activations associated with perceived usefulness and perceived ease of use predict selfreported intentions to use a system. The paper concludes by discussing the study’s implications for underscoring the potential of functional neuroimaging for IS research and the TAM literature

The Determinants of IS User Satisfaction and Dissatisfaction: A Text Mining Approach

Too often, in previous marketing, consumer behavior, and IS research, satisfaction and dissatisfaction are treated as two ends of a bipolar continuum. The researchers of this study argue that satisfaction and dissatisfaction are two distinct dimensions and thus have different determinants. Online reviews, as one type of user-generated contents (UGC), can impact consumer purchase decision and IS user adoption decision. Online reviews are also valuable sources for researchers and practitioners to better understand consumers and users. The researchers of this study extract and analyze online user reviews in the App Store. Sentiment analysis is applied to model user satisfaction and dissatisfaction. Significant determinants, as well as their weights are identified. By using the text mining techniques, the current study demonstrates the separability of satisfaction and dissatisfaction and reveals different influencing factors. The research findings can provide insights into extant IS user satisfaction literature

User Perceptions of Decision Support Effectiveness: Two Production Planning Experiments *

Decision support systems continue to be very popular in business, despite mixed research evidence as to their effectiveness. We hypothesize that what-if analysis, a prominent feature of most decision support systems, creates an “illusion of control” causing users to overestimate its effectiveness. Two experiments involving a production planning task are reported which examine decision makers' perceptions of the effectiveness of what-if analysis relative to the alternatives of unaided decision making, and quantitative decision rules. Experiment 1 found that almost all subjects believed what-if analysis was superior to unaided decision making, although using what-if analysis had no significant effect on performance. Experiment 2 found that decision makers were indifferent between what-if analysis and a quantitative decision rule which, if used, would have led to significant cost savings. Thus, what-if analysis did create an illusion of control: decision makers perceived performance differences where none existed, and did not detect large differences when they were present. In both experiments, decision makers exhibited difficulty realizing that their positive beliefs about what-if analysis were exaggerated. Such misjudgments could lead people to continue using what-if analysis even when it is not beneficial and to avoid potentially superior decision support technologies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73794/1/j.1540-5915.1994.tb00516.x.pd

PRISM II: an open-label study to assess effectiveness of dextromethorphan/quinidine for pseudobulbar affect in patients with dementia, stroke or traumatic brain injury

BACKGROUND: Phase 3 trials supporting dextromethorphan/quinidine (DM/Q) use as a treatment for pseudobulbar affect (PBA) were conducted in patients with amyotrophic lateral sclerosis (ALS) or multiple sclerosis (MS). The PRISM II study provides additional DM/Q experience with PBA secondary to dementia, stroke, or traumatic brain injury (TBI). METHODS: Participants in this open-label, multicenter, 90-day trial received DM/Q 20/10 mg twice daily. The primary outcome was the Center for Neurologic Study-Lability Scale (CNS-LS), assessing change in PBA episode frequency and severity. The CNS-LS final visit score was compared to baseline (primary analysis) and to the response in a previously conducted placebo-controlled trial with DM/Q in patients with ALS or MS. Secondary outcomes included change in PBA episode count and Clinical Global Impression of Change with respect to PBA as rated by a clinician (CGI-C) and by the patient or caregiver (PGI-C). RESULTS: The study enrolled 367 participants with PBA secondary to dementia, stroke, or TBI. Mean (standard deviation [SD]) CNS-LS score improved significantly from 20.4 (4.4) at baseline to 12.8 (5.0) at Day 90/Final Visit (change, -7.7 [6.1]; P < .001, 95 % CI: -8.4, -7.0). This magnitude of improvement was consistent with DM/Q improvement in the earlier phase-3, placebo-controlled trial (mean [95 % CI] change from baseline, -8.2 [-9.4, -7.0]) and numerically exceeds the improvement seen with placebo in that study (-5.7 [-6.8, -4.7]). Reduction in PBA episode count was 72.3 % at Day 90/Final Visit compared with baseline (P < .001). Scores on CGI-C and PGI-C showed that 76.6 and 72.4 % of participants, respectively, were "much" or "very much" improved with respect to PBA. The most frequently occurring adverse events (AEs) were diarrhea (5.4 %), headache (4.1 %), urinary tract infection (2.7 %), and dizziness (2.5 %); 9.8 % had AEs that led to discontinuation. Serious AEs were reported in 6.3 %; however, none were considered treatment related. CONCLUSIONS: DM/Q was shown to be an effective and well-tolerated treatment for PBA secondary to dementia, stroke, or TBI. The magnitude of PBA improvement was similar to that reported in patients with PBA secondary to ALS or MS, and the adverse event profile was consistent with the known safety profile of DM/Q. TRIAL REGISTRATION: Clinicaltrials.gov, NCT01799941, registered on 25 February 2013