61 research outputs found
Dynamical theory of dense groups of galaxies
No full textIt is well known that galaxies associate in groups and clusters. Perhaps 40% of all galaxies are found in groups of 4 to 20 galaxies (e.g., Tully 1987). Although most groups appear to be so loose that the galaxy interactions within them ought to be insignificant, the apparently densest groups, known as compact groups appear so dense when seen in projection onto the plane of the sky that their members often overlap. These groups thus appear as dense as the cores of rich clusters. The most popular catalog of compact groups, compiled by Hickson (1982), includes isolation among its selection critera. Therefore, in comparison with the cores of rich clusters, Hickson's compact groups (HCGs) appear to be the densest isolated regions in the Universe (in galaxies per unit volume), and thus provide in principle a clean laboratory for studying the competition of very strong gravitational interactions. The $64,000 question here is then: Are compact groups really bound systems as dense as they appear? If dense groups indeed exist, then one expects that each of the dynamical processes leading to the interaction of their member galaxies should be greatly enhanced. This leads us to the questions: How stable are dense groups? How do they form? And the related question, fascinating to any theorist: What dynamical processes predominate in dense groups of galaxies? If HCGs are not bound dense systems, but instead 1D change alignments (Mamon 1986, 1987; Walke & Mamon 1989) or 3D transient cores (Rose 1979) within larger looser systems of galaxies, then the relevant question is: How frequent are chance configurations within loose groups? Here, the author answers these last four questions after comparing in some detail the methods used and the results obtained in the different studies of dense groups
A new moment matching algorithm for sampling from partially specified symmetric distributions
No full textA new algorithm is proposed for generating scenarios from a partially specified symmetric multivariate distribution. The algorithm generates samples which match the first two moments exactly and match the marginal fourth moments approximately, using a semidefinite programming procedure. The performance of the
algorithm is illustrated by a numerical example
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Murder and mamon /
No full text"The next riveting mystery in the Tita Rosie's Kitchen series by Mia P. Manansala, Agatha Award-winning author of Arsenic and Adobo. Lila Macapagal's godmothers April, Mae, and June--aka the Calendar Crew--are celebrating the opening of their latest joint business venture, a chain of laundromats. However, what should've been a joyous occasion quickly turns into a tragedy when they discover the body of Ninang April's niece, recently arrived from the Philippines, spinning around inside one of the machines. With Ninang April falling apart from grief and little progress from the Shady Palms Police Department, it's up to Lila and her network to find justice for the young woman. The Calendar Crew have stuck their noses into everybody's business for years, but now it seems the tables are turned as Lila must pry into the Calendar Crew's lives to figure out who has a vendetta against the extremely opinionated yet loving aunties and stop them before they strike again" -
Pusong mamon: Nel Nodding\u27s care ethics in the Filipino educational setting
No full textThis paper evaluates Nel Noddings’s view of moral education in the context of teaching in a Philippine university. It first presents the key aspects of Noddings’s ethical theory, identifying her three strategic moves as follows: the dissolution of the public/private split, the replacement of justice-based punishment system with a caring system, and the promotion of care work as the core of education itself. Through a discussion of two cases of academic dishonesty, the author assesses the merits of these strategies and recommends a re-conceptualization both of care ethics and the existing educational paradigm
Pusong Mamon: Nel Noddings\u27s Care Ethics in the Filipino Educational Setting
No full textThis paper evaluates Nel Noddings’s view of moral education in the context of teaching in a Philippine university. It first presents the key aspects of Noddings’s ethical theory, identifying her three strategic moves as follows: the dissolution of the public/private split, the replacement of justice-based punishment system with a caring system, and the promotion of care work as the core of education itself. Through a discussion of two cases of academic dishonesty, the author assesses the merits of these strategies and recommends a re-conceptualization both of care ethics and the existing educational paradigm
Optimización de elaboración de presupuestos para presentación de procesos licitatorios y supervisión de obras civiles en función de los avances parciales: Caso de estudio Colegio I.E.D Armando Estrada Flórez sede ERM El Mamon.
No full textLa Fundación Social de Técnicas Baltime de Colombia S.A - FUNDEBAN busca mejorar las condiciones de vida en el área de influencia de la Comercializadora Internacional Técnicas Baltime de Colombia S.A. Con enfoque en educación, recreación, salud, deporte, desarrollo económico y ambiental, así como infraestructuras sociales, se identifica la necesidad de gestionar de manera eficiente proyectos de obras civiles. Se destaca un caso específico en el colegio I.E.D. Armando Estrada Flores sede ERM El Mamón, donde el desplome parcial de las paredes plantea riesgos para la seguridad. El documento propone una solución que incluye un sistema de zapatas, columnas y vigas, así como la reubicación de una alberca, con el objetivo de salvaguardar la integridad de las personas y mejorar la infraestructura. El enfoque está en generar una propuesta de presupuesto para abrir un proceso de licitación que permita llevar a cabo estas mejoras
Linear and nonlinear filtering in mathematical finance: a review
No full textCopyright @ The Authors 2010This paper presents a review of time series filtering and its applications in mathematical finance. A summary of results of recent empirical studies with market data are presented for yield curve modelling and stochastic volatility modelling. The paper also outlines different approaches to filtering of nonlinear time series
Higher order sigma point filter: A new heuristic for nonlinear time series filtering
No full textIn this paper we present some new results related to the higher order sigma point filter (HOSPoF), introduced in [1] for filtering nonlinear multivariate time series. This paper makes two distinct contributions. Firstly, we propose a new algorithm to generate a discrete statistical distribution to match exactly a specified mean vector, a specified covariance matrix, the average of specified marginal skewness and the average of specified marginal kurtosis. Both the sigma points and the probability weights are given in closed-form and no numerical optimization is required. Combined with HOSPoF, this random sigma point generation algorithm provides a new method for generating proposal density which propagates the information about higher order moments. A numerical example on nonlinear, multivariate time series involving real financial market data demonstrates the utility of this new algorithm. Secondly, we show that HOSPoF achieves a higher order estimation accuracy as compared to UKF for smooth scalar nonlinearities. We believe that this new filter provides a new and powerful alternative heuristic to existing filtering algorithms and is useful especially in econometrics and in engineering applications
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Relationship between the Temporal Changes in Positron-Emission-Tomography-Imaging-Based Textural Features and Pathologic Response and Survival in Esophageal Cancer Patients
No full textPurpose Although change in standardized uptake value (SUV) measures and PET-based textural features during treatment have shown promise in tumor response prediction, it is unclear which quantitative measure is the most predictive. We compared the relationship between PET-based features and pathologic response and overall survival with the SUV measures in esophageal cancer. Methods: Fifty-four esophageal cancer patients received PET/CT scans before and after chemoradiotherapy. Of these, 45 patients underwent surgery and were classified into complete, partial, and non-responders to the preoperative chemoradiation. SUVmax and SUVmean, two cooccurrence matrix (Entropy and Homogeneity), two run-length matrix (RLM) (high-gray-run emphasis and Short-run high-gray-run emphasis), and two size-zone matrix (high-gray-zone emphasis and short-zone high-gray emphasis) textures were computed. The relationship between the relative difference of each measure at different treatment time points and the pathologic response and overall survival was assessed using the area under the receiver-operating-characteristic curve (AUC) and Kaplan–Meier statistics, respectively. Results: All Textures, except Homogeneity, were better related to pathologic response than SUVmax and SUVmean. Entropy was found to significantly distinguish non-responders from the complete (AUC = 0.79, p = 1.7 × 10−4) and partial (AUC = 0.71, p = 0.01) responders. Non-responders can also be significantly differentiated from partial and complete responders by the change in the run-length and size-zone matrix textures (AUC = 0.71–0.76, p ≤ 0.02). Homogeneity, SUVmax, and SUVmean failed to differentiate between any of the responders (AUC = 0.50–0.57, p ≥ 0.46). However, none of the measures were found to significantly distinguish between complete and partial responders with AUC 0.25). Conclusion: For the patients studied, temporal changes in Entropy and all RLM were better correlated with pathological response and survival than the SUV measures. The hypothesis that these metrics can be used as clinical predictors of better patient outcomes will be tested in a larger patient dataset in the future.Version of Recor
Neoadjuvant short-course radiotherapy or chemoradiation plus consolidative chemotherapy followed by radical operation for locally advanced rectal cancer
No full textIntroductionLimited evidence compares short-course radiotherapy (SCRT) and long-course chemoradiotherapy (LCCRT), both of which are followed by consolidative chemotherapy before radical rectal surgery. We conducted a retrospective cohort study to assess treatment response, survival outcomes, and toxicity in patients with locally advanced rectal cancer.Materials and methodsPatients (cT3–4 and/or N+) treated with SCRT or LCCRT, consolidative chemotherapy, or total mesorectal excision between 2013 and 2021 were identified. the cause-specific cumulative incidence of disease-related treatment failure, locoregional recurrence, distant metastases, and overall survival were evaluated using flexible parametric competing risk analysis and Kaplan–Meier methods, adjusted for treatment regimens and clinicopathological factors. A pathological complete response (pCR), tumor downstaging, and toxicity have been reported.ResultsAmong the 144 patients, 115 (80%) underwent curative rectal surgery. The LCCRT and SCRT groups achieved pCR in 10 (18%) and seven (12%) patients, respectively (odds ratio, 1.68; 95% confidence interval [CI], 0.59–4.78). The adjusted cause-specific hazard ratio for disease-related treatment failure with LCCRT versus SCRT was 0.26 (95% CI, 0.08–0.87). Three-year cumulative probability of disease-related treatment failure was 10.0% and 25.6% for LCCRT and SCRT, respectively. No significant differences in T-downstaging, N-downstaging, significant pathologic downstaging (ypT0-2N0), locoregional failure, distant metastasis, or overall survival were found. Late rectal toxicity occurred in 10 (15%) LCCRT and two (3%) SCRT patients, respectively.ConclusionLCCRT with consolidative chemotherapy demonstrated improved disease-related treatment failure compared with SCRT, despite higher late rectal toxicity. Further research is needed to assess the long-term oncologic outcomes and toxicity
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