154 research outputs found
The Impact of the Internet Tax Freedom Act on State Revenues
The Internet Tax Freedom Act, passed by the U.S. Congress, is both a result of and a potentially important influence on the growth of electronic commerce. This paper examines the impact of the moratorium imposed by the legislation prohibiting the collection of taxes on Internet commerce. Its significance with respect to business-to-business and business-to-consumer commerce is documented by analysis of current sales activities. The paper also explores the potential impact on a variety of sales categories if the moratorium is extended beyond the current three-year period of effect. The discussion illustrates how continuing the force of the legislation will have an increasingly significant effect on both states, which depend on sales tax revenue, and participants in Internet commerce
INFORMATION SYSTEMS SUPPORT FOR ASSESSMENT OF MANAGEMENT PERFORMANCE: AN EXPERIMENTAL EVALUATION
This paper reports the results of a study to determine how individual managers assemble information from automated systems when the task is evaluating organization performance. An experiment was conducted in which managers were given varying forms of information over a period of time and required to accumulate the information they would need for a later evaluation decision. As the results show, there are differences in the way individuals select and assemble reported information system design practices
The Principles at Work In High Performing Information Systems Organizations
Although there is a great deal of discussion about high performing information systems (I/S) organizations, little is known about the characteristics and practices they use. A field study was conducted to learn what principles are applied in organizations widely acknowledged to be high performers. The sample of companies for this field study was chosen by a core team of 15 consultants, practitioners, and academic researchers. On-site, structured interviews were conducted with 105 executives and managers in both the functional areas and the I/S groups of the firms. The findings show that a common set of principles are applied in high performing I/S groups. At the same time, there are distinct differences between these leading companies. The results provide useful insights for practice and for future research
MitoNeoD:a mitochondria-targeted superoxide probe
Mitochondrial superoxide (O2⋅−) underlies much oxidative damage and redox signaling. Fluorescent probes can detect O2⋅−, but are of limited applicability in vivo, while in cells their usefulness is constrained by side reactions and DNA intercalation. To overcome these limitations, we developed a dual-purpose mitochondrial O2⋅− probe, MitoNeoD, which can assess O2⋅− changes in vivo by mass spectrometry and in vitro by fluorescence. MitoNeoD comprises a O2⋅−-sensitive reduced phenanthridinium moiety modified to prevent DNA intercalation, as well as a carbon-deuterium bond to enhance its selectivity for O2⋅− over non-specific oxidation, and a triphenylphosphonium lipophilic cation moiety leading to the rapid accumulation within mitochondria. We demonstrated that MitoNeoD was a versatile and robust probe to assess changes in mitochondrial O2⋅− from isolated mitochondria to animal models, thus offering a way to examine the many roles of mitochondrial O2⋅−production in health and disease
Selective superoxide generation within mitochondria by the targeted redox cycler MitoParaquat
Superoxide is the proximal reactive oxygen species (ROS) produced by the mitochondrial respiratory chain and plays a major role in pathological oxidative stress and redox signaling. While there are tools to detect or decrease mitochondrial superoxide, none can rapidly and specifically increase superoxide production within the mitochondrial matrix. This lack impedes progress, making it challenging to assess accurately the roles of mitochondrial superoxide in cells and in vivo. To address this unmet need, we synthesized and characterized a mitochondria-targeted redox cycler, MitoParaquat (MitoPQ) that comprises a triphenylphosphonium lipophilic cation conjugated to the redox cycler paraquat. MitoPQ accumulates selectively in the mitochondrial matrix driven by the membrane potential. Within the matrix, MitoPQ produces superoxide by redox cycling at the flavin site of complex I, selectively increasing superoxide production within mitochondria. MitoPQ increased mitochondrial superoxide in isolated mitochondria and cells in culture ~a thousand-fold more effectively than untargeted paraquat. MitoPQ was also more toxic than paraquat in the isolated perfused heart and in Drosophila in vivo. MitoPQ enables the selective generation of superoxide within mitochondria and is a useful tool to investigate the many roles of mitochondrial superoxide in pathology and redox signaling in cells and in vivo
15th Annual Legal Issues for Financial Institutions Conference
Program and materials from the 15th Annual Legal Issues for Financial Institutions Conference held by UK/CLE on March 10-11, 1995
True interindividual variability exists in postprandial appetite responses in healthy men but is not moderated by the FTO genotype
Background: After meal ingestion, a series of coordinated hormone responses occur
concomitantly with changes in perceived appetite. It is not known whether interindividual
variability in appetite exists in response to a meal. Objectives: This study aimed to 1) assess
the reproducibility of appetite responses to a meal; 2) quantify individual differences in
responses; and 3) explore any moderating influence of the fat mass and obesity associated
(FTO) gene. Methods: Using a replicated crossover design, 18 healthy men (mean ± SD 28.5
± 9.8 years, 27.0 ± 5.0 kg·m-2
) recruited according to FTO genotype (9 AA, 9 TT) completed
two identical control and two identical standardized meal conditions (5025 kJ) in randomized
sequences. Perceived appetite and plasma acylated ghrelin, total peptide YY (PYY), insulin
and glucose concentrations were measured before and after interventions as primary
outcomes. Interindividual differences were explored using Pearson’s product-moment
correlations between the first and second replicate of the control-adjusted meal response.
Within-participant covariate-adjusted linear mixed models were used to quantify participant by-condition and genotype-by-condition interactions. Results: The meal suppressed acylated
ghrelin and appetite perceptions (standardized effect sizes (ES): 0.18-4.26) and elevated total
PYY, insulin and glucose (ES: 1.96-21.60). For all variables, SD of change scores was
greater in the meal versus control conditions. Moderate-to-large positive correlations were
observed between the two replicates of control-adjusted meal responses for all variables
(r=0.44-0.86, P≤0.070). Participant-by-condition interactions were present for all variables
(P≤0.056). FTO genotype-by-condition interactions were not significant (P≥0.19) and
treatment effect differences between genotype groups were small (ES≤0.27) for all appetite
parameters. Conclusions: Reproducibility of postprandial appetite responses is generally
good. True interindividual variability is present beyond any random within-subject variation
in healthy men but is not moderated by the FTO genotype. These findings highlight the
3
importance of exploring individual differences in appetite for the prevention and/or treatment
of obesity. Clinical trial registry number: NCT03771690 (ClinicalTrials.gov)
14th Annual Conference on Legal Issues For Financial Institutions
Materials from the 14th Annual Conference on Legal Issues For Financial Institutions held by UK/CLE in March 1994
Regression toward the mean – a detection method for unknown population mean based on Mee and Chua's algorithm
<p>Abstract</p> <p>Background</p> <p>Regression to the mean (RTM) occurs in situations of repeated measurements when extreme values are followed by measurements in the same subjects that are closer to the mean of the basic population. In uncontrolled studies such changes are likely to be interpreted as a real treatment effect.</p> <p>Methods</p> <p>Several statistical approaches have been developed to analyse such situations, including the algorithm of Mee and Chua which assumes a known population mean <it>μ</it>. We extend this approach to a situation where <it>μ </it>is unknown and suggest to vary it systematically over a range of reasonable values. Using differential calculus we provide formulas to estimate the range of <it>μ </it>where treatment effects are likely to occur when RTM is present.</p> <p>Results</p> <p>We successfully applied our method to three real world examples denoting situations when (a) no treatment effect can be confirmed regardless which <it>μ </it>is true, (b) when a treatment effect must be assumed independent from the true <it>μ </it>and (c) in the appraisal of results of uncontrolled studies.</p> <p>Conclusion</p> <p>Our method can be used to separate the wheat from the chaff in situations, when one has to interpret the results of uncontrolled studies. In meta-analysis, health-technology reports or systematic reviews this approach may be helpful to clarify the evidence given from uncontrolled observational studies.</p
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