Magnification relations in gravitational lensing via multidimensional residue integrals

We investigate the so-called magnification relations of gravitational lensing models. We show that multidimensional residue integrals provide a simple explanation for the existence of these relations, and an effective method of computation. We illustrate the method with several examples, thereby deriving new magnification relations for galaxy lens models and microlensing (point mass lensing).Comment: 16 pages, uses revtex4, submitted to Journal of Mathematical Physic

Dispersion strenghthening of metals Progress report, Sep. 1965 - Feb. 1966

Apparatus constructed for controlled oxidation of iron-beryllium alloy powder

Some aspects of environmental physiology of raft grown mussels

Mussels (P viridis L) from marine intertidal region, when transplanted and grown under constant submergence in estuarine environment (on a floating raft) display a wide array of physi~logical adapt ions in osmoregulation, growth and annual reproduction cycle

Clinical and economic outcomes in an observational study of COPD maintenance therapies: multivariable regression versus propensity score matching

Melissa H Roberts1, Anand A Dalal21Lovelace Clinic Foundation, (Lovelace Respiratory Research Institute at the time of the study), Albuquerque, NM, 2US Health Outcomes, GlaxoSmithKline, Durham, NC, USAPurpose: To investigate equivalency of results from multivariable regression (MR) and propensity score matching (PSM) models, observational research methods used to mitigate bias stemming from non-randomization (and consequently unbalanced groups at baseline), using, as an example, a large study of chronic obstructive pulmonary disease (COPD) initial maintenance therapy.Methods: Patients were 32,338 health plan members, age ≥40 years, with COPD initially treated with fluticasone propionate/salmeterol combination (FSC), tiotropium (TIO), or ipratropium (IPR) alone or in combination with albuterol. Using MR and PSM methods, the proportion of patients with COPD-related health care utilization, mean costs, odds ratios (ORs), and incidence rate ratios (IRRs) for utilization events were calculated for the 12 months following therapy initiation.Results: Of 12,595 FSC, 9126 TIO, and 10,617 IPR patients meeting MR inclusion criteria, 89.1% (8135) of TIO and 80.2% (8514) of IPR patients were matched to FSC patients for the PSM analysis. Methods produced substantially similar findings for mean cost comparisons, ORs, and IRRs for most utilization events. In contrast to MR, for TIO compared to FSC, PSM did not produce statistically significant ORs for hospitalization or outpatient visit with antibiotic or significant IRRs for hospitalization or outpatient visit with oral corticosteroid. As in the MR analysis, compared to FSC, ORs and IRRs for all other utilization events, as well as mean costs, were less favorable for IPR and TIO.Conclusion: In this example of an observational study of maintenance therapy for COPD, more than 80% of the original treatment groups used in the MR analysis were matched to comparison treatment groups for the PSM analysis. While some sample size was lost in the PSM analysis, results from both methods were similar in direction and statistical significance, suggesting that MR and PSM were equivalent methods for mitigating bias.Keywords: multivariate analysis, outcomes research, propensity score, pulmonary disease, chronic obstructive, statistical bias, statistical model

Force‐sensing catheters during pediatric radiofrequency ablation: The FEDERATION Study

Background Based on data from studies of atrial fibrillation ablations, optimal parameters for the TactiCath (TC; St. Jude Medical, Inc) force‐sensing ablation catheter are a contact force of 20 g and a force‐time integral of 400 g·s for the creation of transmural lesions. We aimed to evaluate TC in pediatric and congenital heart disease patients undergoing ablation. Methods and Results Comprehensive chart and case reviews were performed from June 2015 to March 2016. Of the 102 patients undergoing electrophysiology study plus ablation, 58 (57%) underwent ablation initially with a force‐sensing catheter. Patients had an average age of 14 (2.4–23) years and weight of 58 (18–195) kg with 15 patients having abnormal cardiac anatomy. Electrophysiology diagnoses for the + TC group included 30 accessory pathway–mediated tachycardia, 24 atrioventricular nodal reentrant tachycardia, and 7 other. Baseline generator settings included a power of 20 W, temperature of 40°, and 6 cc/min flow during lesion creation with 11 patients (19%) having alterations to parameters. Seventeen patients (30%) converted to an alternate ablation source. A total of 516 lesions were performed using the TC with a median contact force of 6 g, force‐time integral of 149 g·s, and lesion size index of 3.3. Median‐term follow‐up demonstrated 5 (10%) recurrences with no acute or median‐term complications. Conclusions TactiCath can be effectively employed in the treatment of pediatric patients with congenital heart disease with lower forces than previously described in the atrial fibrillation literature. Patients with atrioventricular nodal reentrant tachycardia or atrioventricular reciprocating tachycardia may not require transmural lesions and the TC may provide surrogate markers for success during slow pathway ablation. </jats:sec

Research on mechanisms of alloy strengthening. Part 1 - Strengthening through fine particle dispersion. Part 2 - Control of structure and properties by means of rapid quenching of liquid metals /splat cooling/ Semiannual report

Alloy strengthening mechanisms - strengthening by fine particle dispersion, and structure and properties control by rapid quenching or splat cooling of liquid metal

Clickstream Data Mining and Market Segmentation

Clickstream data is one of the most important sources of information in websites USAge and customers\u27 behavior in Banks e-services. A number of web USAge mining scenarios are possible depending on the available information. While simple traffic analysis based on clickstream data may easily be performed to improve the e-banks services. The banks need data mining techniques to substantially improve Banks e-services activities. The relationships between data mining techniques and the Web USAge mining are studied. Web structure mining has three types of these types are web USAge structure, mining data streams, and web content. The integration between the Web USAge mining and data mining techniques are presented for processes at different stages, including the pattern discovery phases, and introduces banks cases, that have analytical mining technique. A general framework for fully integrating domain Web USAge mining and data mining techniques are represented for processes at different stages. Data Mining techniques can be very helpful to the banks for better performance, acquiring new customers, fraud detection in real time, providing segment based products, and analysis of the customers purchase patterns over time. And in Market Segmentation The importance of data mining techniques for market segmentation is becoming indispensable in the field of marketing research. This is the first identified academic literature review of the available data mining techniques related to market segmentation. This research paper provides surveys of the available literature on data mining techniques in market segmentation. Eight online journal databases were used for searching, and finally, 103 articles were selected and categorized into 13 groups based on data mining techniques. The utility of data mining techniques and suggestions are also discussed. The findings of this study show that neural networks is the most used method, and kernel-based method is the most promising data mining techniques. Our research work provides a comprehensive understanding of past, present as well as future research trend on data mining techniques in market segmentation

Astrometric Microlensing as a Method of Discovering and Characterizing Extra-Solar Planets

We introduce a new method of searching for and characterizing extra-solar planets. We show that by monitoring the center-of-light motion of microlensing alerts using the next generation of high precision astrometric instruments the probability of detecting a planet orbiting the lens is high. We show that adding astrometric information to the photometric microlensing lightcurve greatly helps in determining the planetary mass and semi-major axis. We introduce astrometric maps as a new way for calculating astrometric motion and planet detection probabilities. Finite source effects are important for low mass planets, but even Earth mass planets can give detectable signals.Comment: 9 pages includes 8 postscript figures, AAS Latex, submitted to Ap