758 research outputs found
A Detailed Presentation of the Theory, Methods and Empirical Findings in the e-book An Introduction to Macroeconomic Models in Excel: A Data-Driven, Arithmetic Approach for Principles of Economics Students
The focus of this article is on highlighting the principal results contained in the recently published ebook: An Introduction to Macroeconomic Models in Excel: A Data-Driven, Arithmetic Approach for Principles of Economics Students. The discussion below will present the key empirical findings and the most important steps in the methodological approach. A secondary title for the book could be: Examining the Operating Principles, Calculation Routines, and Data Requirements that Together Constitute a Functioning, Entry-level, Macro Model Tool Kit (set of templates). Students who study these templates will acquire the practical ability to do qualitative analysis of current macroeconomic trends
An Exploration of Monophonic Instrument Classification Using Multi-Threaded Artificial Neural Networks
The use of computers for automated music analysis could benefit several aspects of academia and industry, from psychological and music research, to intelligent music selection and music copyright investigation. In the following thesis, one of the first steps of automated musical analysis, i.e., monophonic instrument recognition, was explored. A multi-threaded artificial neural network was implemented and used as the classifier in order to utilize multi-core technology and allow for faster training. The parallelized batch-mode backpropagation algorithm used provided linear speedup, an improvement to the current literature. For the classification experiments, eleven different sets of instruments were used, starting with perceptively dissimilar instruments (i.e., bass vs. trumpet), moving towards more similar sounding instruments (i.e., violin vs. viola; oboe vs. bassoon; xylophone vs. vibraphone, etc.,). From the 70 original musical features extracted from each audio sample, a sequential forward selection algorithm was employed to select only the most salient features that best differentiate the instruments in question. Using twenty runs for each set of instruments (i.e., 10 sets of a 50/50 cross-validation training paradigm), the test results were promising, with classification rates ranging from a mean of 76% to 96%, with many individual runs reaching a perfect 100% score. The conclusion of this thesis confirms the use of multi-threaded artificial neural networks as a viable classifier in single instrument recognition of perceptively similar sounding instruments
Kolyvagin systems of Stark units
In this paper we construct, using Stark elements of Rubin [Ann. Inst. Fourier
(Grenoble) 46 (1996), no. 1, 33-62], Kolyvagin systems for certain modified
Selmer structures (that are adjusted to have core rank one in the sense of
[Mem. Amer. Math. Soc. 168 (2004), no. 799] and prove a Gras-type conjecture,
relating these Kolyvagin systems to appropriate ideal class groups, refining
the results of Rubin [J. Reine Angew. Math. 425 (1992), 141-154].Comment: 27 pages, revised version, accepted for publication in J. Reine
Angew. Math. (Crelle's
Chronic intestinal inflammation: Inflammatory bowel disease and colitis-associated colon cancer
The inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic inflammatory disorders of the intestine. The prevalence in the United States is greater than 200 cases per 100,000, with the total number of IBD patients between 1 and 1.5 million. CD may affect all parts of the gastrointestinal tract, from mouth to anus, but most commonly involves the distal part of the small intestine or ileum, and colon. UC results in colonic inflammation that can affect the rectum only, or can progress proximally to involve part of or the entire colon. Clinical symptoms include diarrhea, abdominal pain, gastrointestinal bleeding, and weight loss. A serious long-term complication of chronic inflammation is the development of colorectal cancer. A genetic basis for IBD had long been recognized based on the increased familial risk. However, significant discordance for CD in twins, and a much less robust phenotypic concordance for UC, suggested additional factors play a role in disease pathogenesis, including environmental factors. In the past several years, progress in understanding the molecular basis of IBD has accelerated, beginning with the generation of animal models of colitis and progressing to the identification of specific genetic markers from candidate gene, gene linkage, and genome-wide association analyses. Genetic studies have also resulted in the recognition of the importance of environmental factors, particularly the crucial role of the gut microbiota in CD and UC. Altered immune responses to the normal intestinal flora are key factors in IBD pathogenesis. In this research topic, the genetic basis of IBD, the genetic and cellular alterations associated with colitis-associated colon cancer, and the emerging role of the intestinal microbiota and other environmental factors will be reviewed
A Bound on the Light Emitted During the TP-AGB Phase
The integrated luminosity of the TP-AGB phase is a major uncertainty in
stellar population synthesis models. We use the white dwarf initial final mass
relation and stellar interiors models to demonstrate that a significant
fraction of the core mass growth for intermediate (1.5 < Msun < 6) mass stars
takes place during the TP-AGB phase. We find evidence that the peak fractional
core mass contribution for TP-AGB stars is ~20% and occurs for stars between 2
Msun and 3.5 Msun. Using a simple fuel consumption argument we couple this core
mass increase to a lower limit on the TP-AGB phase energy output. Roughly half
of the energy released in models of TP-AGB stars can be directly accounted for
by this core growth; while the remainder is predominantly the stellar yield of
He. A robust measurement of the emitted light in this phase will therefore set
strong constraints on helium enrichment from TP-AGB stars, and we estimate the
yields predicted by current models as a function of initial mass. Implications
for stellar population studies and prospects for improvements are discussed.Comment: Submitted to the Astrophysical Journal. 25 pages, 2 figures
The Leg-Tuck versus the Plank-Hold Relative to the Army Combat Fitness Test: Interactions with Body Composition, Strength and Sex.
In 2020 the U.S. Army replaced their older physical fitness test with the Army Combat Fitness Test (ACFT) to replicate modern battlefield demands. One component of the test, the leg-tuck (LTK) was found to disproportionately fail female soldiers. Following an independent review, the Army adopted the plank-hold (PLK), attempting to limit the influence of sex differences during the assessment. However, research regarding performance, relationships, and the influence of sex on the LTK versus the PLK is limited. PURPOSE: To determine relationships between the LTK, PLK, sex, body composition and abdominal and grip strength. METHODS: 49 physically active civilian college students (28 males, 21 females) were recruited as a surrogate population for Army personnel in this study. The following data were collected in one session: height; body mass (BM), body fat (BF%) and muscle mass percentage (MM%) measured via bioelectrical impedance analysis; combined grip strength (CGS) from both hands; the LTK; and the PLK. ACFT standards were utilized for the LTK and PLK for all participants and a 10-minute rest was provided between tests. Independent t-tests compared sexes in all variables (p\u3c.05). Partial correlations controlling for sex detailed relationships between the LTK and PLK and the other variables (p\u3c.05). Stepwise regression controlling for sex derived predictive relationships for the LTK and PLK. RESULTS: There were significant between-sex differences with males being taller, having greater BM, MM%, and performing better in CGS and the LTK. Females had greater BF%. There was no significant between-sex difference found in PLK performance. The LTK significantly correlated with PLK (r=.404), height (r=.546), BM (r=.343), BF% (r=-.639), MM% (r=.697) and CGS (r=.732). In addition to the relationship with the LTK, the PLK only correlated with BF% (r=-.295). Stepwise regression analysis showed LTK performance was predicted by sex (r2=.441), grip strength (r2=.595), and PLK performance (r2=.662). When controlling for sex, a significant predictive relationship was not produced for the PLK. CONCLUSION: Compared to the LTK, the PLK appeared to minimize the influence of sex and body composition on task performance in college-aged civilians. More research is needed on whether the PLK relates to Army job tasks
Health-Related Quality of Life Outcomes With Tofacitinib Treatment in Patients With Ulcerative Colitis in the Open-Label Extension Study, OCTAVE Open
BACKGROUND
Tofacitinib is an oral small molecule Janus kinase inhibitor for the treatment of ulcerative colitis. We report health-related quality of life (HRQoL) outcomes in patients with ulcerative colitis in the phase 3 open-label, long-term extension study, OCTAVE Open.
METHODS
The Inflammatory Bowel Disease Questionnaire (IBDQ), EuroQoL-5 Dimensions Health Questionnaire, and 36-Item Short Form Survey scores were analyzed up to month (M) 72 in 4 subpopulations: patients in remission at baseline (maintenance remitters) assigned tofacitinib 5 mg twice daily and patients not in remission at baseline (maintenance nonremitters, maintenance treatment failures, and induction nonresponders [IndNRs]) assigned tofacitinib 10 mg twice daily in OCTAVE Open. Data were analyzed overall and stratified by corticosteroid use at baseline, prior tumor necrosis factor inhibitor failure, and prior immunosuppressant failure.
RESULTS
Among maintenance remitters and nonremitters, HRQoL outcomes were maintained up to M72: 80.0% and 100.0% of patients had an IBDQ total score ≥170, respectively. At baseline, 7.4% of maintenance treatment failures had an IBDQ total score ≥170, and this increased to 54.3% and 75.0% at M2 and M72, respectively. Corresponding values for IndNRs were 22.6%, 51.0%, and 86.0%. HRQoL outcomes were independent of treatment history. Among patients not in remission at baseline, improvement in EuroQoL-5 Dimensions Health Questionnaire and 36-Item Short Form Survey scores was maintained or achieved by M2, and steady to M72 or M33, with maintenance treatment failures and IndNR subpopulations undergoing the biggest improvements from baseline.
CONCLUSIONS
A continued favorable impact on HRQoL was revealed with long-term tofacitinib treatment in OCTAVE Open, regardless of baseline remission status or treatment history. (ClinicalTrials.gov; number: NCT01470612)
Constraining the Size of the Circumgalactic Medium Using the Transverse Autocorrelation Function of C IV Absorbers in Paired Quasar Spectra
The circumgalactic medium (CGM) plays a vital role in the formation and
evolution of galaxies, acting as a lifeline between galaxies and the
surrounding intergalactic medium (IGM). In this study we leverage a unique
sample of quasar pairs to investigate the properties of the CGM with absorption
line tomography. We present a new sample of medium resolution Keck/ESI,
Magellan/MagE, and VLT/XSHOOTER spectra of 29 quasar pairs at redshift . We supplement the sample with additional spectra of 32 pairs from the
literature, creating a catalog of 61 quasar pairs with angular separations
between 1.7" and 132.9" and projected physical separations () between
14 kpc and 887 kpc. We construct a catalog of 906 metal-line absorption
doublets of C IV () with equivalent widths ranging
from 6 m{\AA} m{\AA}. The best fit linear model to
the log-space equivalent width frequency distribution () of the sample yields coefficients of and
. To constrain the projected extent of C IV, we calculate the
transverse autocorrelation function. The flattening of the autocorrelation
function at low provides a lower limit for the coherence length of
the metal enriched CGM - on the order of 200 comoving kpc. This
physical size constraint allows us to refine our understanding of the metals in
the CGM, where the extent of C IV in the CGM depends on gas flows, feedback,
timescale of metal injection and mixing, and the mass of the host galaxies.Comment: 19 pages, 8 figures, 2 tables, Accepted for publication by The
Astronomical Journa
Use of clinically relevant responder threshold criteria to evaluate the response to treatment in the Phase III PATENT-1 study
Abstract BACKGROUND: In PATENT-1, riociguat significantly improved 6-minute walking distance (6MWD) and a range of secondary end-points in patients with pulmonary arterial hypertension (PAH). We investigated whether riociguat increased the proportion of patients achieving clinically relevant responder thresholds compared with placebo during PATENT-1. METHODS: In PATENT-1, a randomized, double-blind study, treatment-naïve patients or patients on background PAH-targeted therapy with symptomatic PAH received 12 weeks of treatment with placebo, riociguat up to 2.5 mg 3 times daily, or riociguat up to 1.5 mg 3 times daily. Increases in 6MWD ≥40 m, 6MWD ≥380 m, cardiac index ≥2.5 liter/min/m(2), mixed venous oxygen saturation ≥65%, World Health Organization functional class I/II, N-terminal pro-brain natriuretic peptide <1,800 pg/ml, and right atrial pressure <8 mm Hg were chosen as threshold criteria of a positive response. RESULTS: Riociguat increased the proportion of treatment-naïve patients and patients on background PAH-targeted therapy with 6MWD ≥380 m at Week 12 (+21% and +15%, respectively), whereas there was a small reduction in 6MWD in placebo-treated patients for both sub-groups. Riociguat also increased the proportion of treatment-naïve patients and patients on background PAH-targeted therapy achieving World Health Organization functional class I/II (+12% and +19%, respectively) and cardiac index ≥2.5 liter/min/m(2) (+30% and +33%, respectively) at Week 12, whereas there was little change in the respective placebo groups. CONCLUSIONS: Compared with placebo, riociguat increased the proportion of treatment-naïve patients and patients on background PAH-targeted therapy who fulfilled criteria defining a positive response to therapy
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