1,105 research outputs found
Globally convergent techniques in nonlinear Newton-Krylov
Some convergence theory is presented for nonlinear Krylov subspace methods. The basic idea of these methods is to use variants of Newton's iteration in conjunction with a Krylov subspace method for solving the Jacobian linear systems. These methods are variants of inexact Newton methods where the approximate Newton direction is taken from a subspace of small dimensions. The main focus is to analyze these methods when they are combined with global strategies such as linesearch techniques and model trust region algorithms. Most of the convergence results are formulated for projection onto general subspaces rather than just Krylov subspaces
Nonequilibrium electron transport using the density matrix renormalization group
We extended the Density Matrix Renormalization Group method to study the real
time dynamics of interacting one dimensional spinless Fermi systems by applying
the full time evolution operator to an initial state. As an example we describe
the propagation of a density excitation in an interacting clean system and the
transport through an interacting nano structure
I series of purchasing research practitioner brochures
The i-Series Research FamilyThe I-Series is the result of over ten year’s worth of cumulative research by the Innovation, Purchasing and Supply Research Team at Bristol Business School. All of this research is aimed at Purchasing Practitioners and their supporting Academic community. Every piece of research had the aim to be;-IndependentTopicalAimed at practitionersAvailable to allEasy to understandBased on sound academic researchAccompanied by a toolset where appropriateThis research has been well received with its collective findings having been accessed by over 35,000 people in 32 countrie
Query expansion based on conceptual and contextual term relationships in Wikipedia
The dramatic increase in information on the World Wide Web makes it more difficult for web users using web search engines to effectively satisfy their information needs The users' lack of knowledge regarding the searched topics creates a complicated problem when formulating an effective query. Query expansion can play an essential role in overcoming such a deficit. However, because they lack sufficient knowledge about the searched topics, users sometimes find it difficult to evaluate the relatedness of the system's
automatically expanded terms. This problem arises mostly in domain-specific areas, e.g Social Science. In this paper, we expand the queries based on a structured, open knowledge resource on the Web (Wikipedia). We link the entities from a domain-specific corpus (qualitative journals in social science) to Wikipedia entities. With Wikipedia serving as background knowledge, we
help users with their selections by providing the most likely related terms. Furthermore, users are provided with contextual information that describes
each expanded term in order to give users a clearer idea about the meaning of each expanded term. By utilizing 10 test queries chosen by experts who also evaluated the results, we compared the results of using Wikipedia with the
results achieved by using a qualitative journal (author's abstract
The epidemiology of uveal melanoma in Germany: a nationwide report of incidence and survival between 2009 and 2015
Purpose: To calculate the overall incidence of uveal melanoma in Germany and to compare incidences in different German states. In addition, we computed the overall and cancer-specific survival rates nationwide.
Methods: Incidence data for the period between 2009 and 2015, covering the entire German population, was collected through the German Center for Cancer Registry. ICD-O-3 topography codes C69.3-C69.4 and histology codes for melanoma subtypes were used to collect the incidence data. Confidence Intervals with a level of 95% (95% CI) were calculated for rates. Survival was calculated using the Kaplan–Meier. The log-rank test was used for survival comparisons.
Results: This study comprised 3654 patients with uveal melanomas, including 467 (12.8%) with iridial and ciliary body tumors. The overall age-standardized incidence rate (ASIR) was 6.41 person per million. Generally, the ASIR was higher in males than females (6.67 (95% CI 6.37–6.98) vs. 6.16 (95% CI 5.88–6.45 per million). Higher crude incidence rates were noted in the northeastern states (12.5 per million (95% CI 10.5–14.7) in Mecklenburg-Vorpommern) compared with the southwestern states (2.1 per million (95% CI 1.7–2.6) in Hessen). The 5-year overall survival stood at 47%, while the cancer-specific survival stood at 84%. Multivariate analysis showed that women, younger patients, and patients living in Berlin achieved significantly higher overall survival.
Conclusion: Overall ASIR of uveal melanoma in Germany indicates that the disease is more common in males and that it follows the same geographical distribution previously noted in central European countries, with the highest incidence in northern parts of Germany
Converging to Gosper's Algorithm
Given two polynomials, we find a convergence property of the GCD of the
rising factorial and the falling factorial. Based on this property, we present
a unified approach to computing the universal denominators as given by Gosper's
algorithm and Abramov's algorithm for finding rational solutions to linear
difference equations with polynomial coefficients.Comment: 13 page
OR-53: Plasma immunoreactive endothelin-1 levels in hypertensive rats and human subjects
Endothelin-1 (ET-1) is an endothelium-derived potent vasoconstrictor peptide of 21 amino acids. To establish reference values in different forms and models of hypertension and in human subjects an assay for plasma ET-1 was optimized. Immunoreactive (ir-) ET-1 is extracted by acetone from 1 ml plasma and subjected to a sensitive sandwich type enzyme linked immunosorbent assay. The detection limit for plasma ET-1 (3 SD above zero readings) is 0.05 fmol/ml. Mean recoveries of the 1, 2, 5, 10 fmol of ET-1 added to 1 ml plasma (n = 5, each) were 66, 75, 85 and 92 % respectively. The within-assay coefficients of variation were 12, 5, 3, 3 and 0.5 % for plasma ET-1 concentrations of 0.84, 1.5, 2.3, 5.2 and 9.9 fmol/ml respectively. Between-assay coefficients of variation for two human control plasmas containing 1.0 fmol/ml (n = 8) and 1.2 fmol/ml ET-1 (n = 7) were 8% and 10% respectively. Assay accuracy was demonstrated by the consistent recoveries of added ET-1 and by the linearity of ir-ET-1 concentrations measured in serially diluted plasma extracts (r = 0.99). No ir-ET-1 was detected when albumin buffer was extracted instead of plasma (buffer blank). Using this method, we found increased ir-ET-1 levels in plasma of three experimental rat models of hypertension. (i) Plasma ir-ET-1 concentrations were significantly higher in stroke-prone spontaneously hypertensive rats (SP-SHR) than in normotensive Wistar rats. (ii) DOCA-salt hypertensive rats exhibited 4 times higher ir-ET-1 levels than sham operated control rats. (iii) One kidney-one clip (1K-1C) hypertensive rats showed moderately increased ir-ET-1 levels compared to sham operated controls. In contrast, the ir-ET-1 levels in plasma of SHR were half that of normotensive Wistar rats. In two kidney-one clip (2K-1C) Goldblatt hypertensive rats, the plasma ir-ET-1 concentrations were not different from sham-operated control rats. The plasma ir-ET-1 concentrations of 37 healthy human subjects were 0.85 ± 0.26 fmol/ml (mean ± SD). We conclude that the present assay reliably measures plasma immunoreactive ET-1 levels in rats and in human subjects. Normal plasma ET-1 concentrations in humans and conscious rats are in the low picomolar rang
Eclipse Ballooning STEM Outreach for Elementary, Middle, and High School Education
To promote Science, Technology, Engineering and Mathematics (STEM) education through ballooning, the North Dakota Space Grant Consortium (NDSGC) organizes an annual Near-Space Balloon Competition (NSBC) for students in grades 6 - 12. Students across the state of North Dakota have the opportunity to launch experiments into a near- space environment. The students learn how to write proposals, design payloads, and analyze data. They learn through an active, inquiry-based style that will prepare them for real-world engineering and critical thinking jobs. In 2016, NSBC proposed Great American Eclipse as the theme for the competition, thus the students were focused on designing heliocentric payloads.
To promote STEM education to students of all ages, North Dakota Atmospheric and Educational Student Initiated Research (ND-AESIR) team partnered with third grade classes in a North Dakota tribal community for a balloon launch during the 2017 total solar eclipse. Students submitted ping pong balls, which were filled with items of personal and cultural significance. The initiative allowed students to be involved in a space mission and educate them about space. ND-AESIR flew the ping pong balls as a secondary payload during the total solar eclipse from Rexburg, Idaho. After the successful launch and retrieval of the payloads, the ping pong balls were returned to the students, who can now say that their treasured items have touched near space! These two outreach projects took advantage of the opportunity to focus on a rare astronomical event, providing an unique venue to inspire the students towards STEM involvement
Olympic anti-doping laboratory:The analytical technological road from 2016 Rio De Janeiro to 2021 Tokyo
The summer Olympic Games is the major mega sports event since the first modern era Olympiad, held in Athens, Greece in 1896. International Olympic Committee (IOC) has the responsibility of the organization of the summer and winter Games ensuring the broadcast in all corners of earth. The World Anti-Doping Agency (WADA) is the responsible organization of the fight against doping in sports. IOC and WADA support the event's country WADA Accredited Laboratory to incorporate the maximum of the new analytical technologies to become applicable during the event's antidoping testing. The current study reviewed the last 5 years progresses of the antidoping system with emphasis on the laboratory field
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