Analysis of contingency tables based on generalised median polish with power transformations and non-additive models

Contingency tables are a very common basis for the investigation of effects of different treatments or influences on a disease or the health state of patients. Many journals put a strong emphasis on p-values to support the validity of results. Therefore, even small contingency tables are analysed by techniques like t-test or ANOVA. Both these concepts are based on normality assumptions for the underlying data. For larger data sets, this assumption is not so critical, since the underlying statistics are based on sums of (independent) random variables which can be assumed to follow approximately a normal distribution, at least for a larger number of summands. But for smaller data sets, the normality assumption can often not be justified. Robust methods like the Wilcoxon-Mann-Whitney-U test or the Kruskal-Wallis test do not lead to statistically significant p-values for small samples. Median polish is a robust alternative to analyse contingency tables providing much more insight than just a p-value. Median polish is a technique that provides more information than just a p-value. It explains the contingency table in terms of an overall effect, row and columns effects and residuals. The underlying model for median polish is an additive model which is sometimes too restrictive. In this paper, we propose two related approach to generalise median polish. A power transformation can be applied to the values in the table, so that better results for median polish can be achieved. We propose a graphical method how to find a suitable power transformation. If the original data should be preserved, one can apply other transformations – based on so-called additive generators – that have an inverse transformation. In this way, median polish can be applied to the original data, but based on a non-additive model. The non-linearity of such a model can also be visualised to better understand the joint effects of rows and columns in a contingency table

R Aquarii: The Large-Scale Optical Nebula and the Mira Variable Position

The R Aquarii symbiotic star system is surrounded by a large-scale optical nebula. We present observations of the nebular [O III] structure and discuss its morphological significance in context with previously observed small-scale radio-continuum features, which may be related. We suggest that a precessing accretion disk may explain the global features of both the large-scale optical emission and the small-scale radio emission. Moreover, we have determined an accurate position of the system\u27s Mira, which suggests that a recent theoretical model, yielding an egg-shaped central H II region for symbiotic systems with certain physical parameters, may apply to R Aquarii. The optical position of the 387d period Mira variable is consistent with our previous findings in the radio, that SiO maser emission is far removed from the Mira photosphere

Comparisons of SiO Maser and Long-Period Variable Positions in the Aquarii and Omicron Ceti Binary Systems

We have determined that the absolute position of the centroid of SiO maser-emitting spots toward both R A~r ~nd o Cet are coincident with the position of the long-period variables (LPVs) in these binary systems to within the errors of measurement. The SiO positions were determined with the Hat Creek interferometer while the LPV positions were determined with the 8 inch (20 em) transit circle of the US Naval Observatory: These results contradict an earlier report of a circumbinary SiO maser far removed from the LPV in the R Aqr binary system, and we suggest statistical reasons for the discrepancy. We present high-resolution spectra of both sources and discuss possible models

Quinolines from the Cyclocondensation of Isatoic Anhydride With Ethyl Acetoacetate: Preparation of Ethyl 4-Hydroxy-2-Methylquinoline-3-Carboxylate and Derivatives

A convenient two-step synthesis of ethyl 4-hydroxy-2-methylquinoline-3-carboxylate derivatives has been developed starting from commercially available 2-aminobenzoic acids. In step 1, the anthranilic acids are smoothly converted to isatoic anhydrides using solid triphosgene in THF. In step 2, the anhydride electrophiles are reacted with the sodium enolate of ethyl acetoacetate, generated from sodium hydroxide, in warm N,N-dimethylacetamide resulting in the formation of substituted quinolines. A degradation–build-up strategy of the ethyl ester at the 3-position allowed for the construction of the α-hydroxyacetic acid residue required for the synthesis of key arylquinolines involved in an HIV integrase project

Housing Needs in Rural Communities

This study explored housing in small rural communities in an attempt to understand the available housing stock, perceptions of the need for housing, and perceived barriers to housing development. Data were collected through computer-assisted telephone interviews with key community informants. Interviews included forced-choice as well as open-ended questions. Housing issues are described through the words of community leaders with the goal of understanding communities\u27 needs and constraints. Lower cost housing for both renters and owners and housing options for elderly individuals continue to be areas of need in rural communities

Complication Prediction after Esophagectomy with Machine Learning

Esophageal cancer can be treated effectively with esophagectomy; however, the postoperative complication rate is high. In this paper, we study to what extent machine learning methods can predict anastomotic leakage and pneumonia up to two days in advance. We use a dataset with 417 patients who underwent esophagectomy between 2011 and 2021. The dataset contains multimodal temporal information, specifically, laboratory results, vital signs, thorax images, and preoperative patient characteristics. The best models scored mean test set AUROCs of 0.87 and 0.82 for leakage 1 and 2 days ahead, respectively. For pneumonia, this was 0.74 and 0.61 for 1 and 2 days ahead, respectively. We conclude that machine learning models can effectively predict anastomotic leakage and pneumonia after esophagectomy

Simultaneous liver-pancreas transplantation for cystic fibrosis-related liver disease: A multicenter experience

Background: Diabetes is associated with increased morbidity and mortality in patients with cystic fibrosis (CF). While liver transplantation is well established for CF-related liver disease (CFLD), the role of simultaneous liver pancreas transplantation is less understood. Methods: We polled 81 pediatric transplantation centers to identify and characterize subjects who had undergone simultaneous liver pancreas transplantation and obtain opinions about this procedure in CFLD. Results: Fifty (61.7%) polled transplant centers responded and 94% reported that they would consider simultaneous liver pancreas transplantation for CFLD and diabetes. A total of 8 patients with simultaneous liver pancreas transplantation were identified with median follow up of 38 months. All patients had pre-existing diabetes. Exocrine and endocrine pancreatic function was initially restored in all patients with later functional loss in one patient. Body mass index Z-score increased between one year pre-transplantation and one year post-transplantation (P = 0.029). Conclusions: Patients with CFLD undergoing initial assessment for liver transplantation may benefit from consideration of simultaneous liver pancreas transplantation. (C) 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved