Imputation Estimators Partially Correct for Model Misspecification

Inference problems with incomplete observations often aim at estimating population properties of unobserved quantities. One simple way to accomplish this estimation is to impute the unobserved quantities of interest at the individual level and then take an empirical average of the imputed values. We show that this simple imputation estimator can provide partial protection against model misspecification. We illustrate imputation estimators' robustness to model specification on three examples: mixture model-based clustering, estimation of genotype frequencies in population genetics, and estimation of Markovian evolutionary distances. In the final example, using a representative model misspecification, we demonstrate that in non-degenerate cases, the imputation estimator dominates the plug-in estimate asymptotically. We conclude by outlining a Bayesian implementation of the imputation-based estimation.Comment: major rewrite, beta-binomial example removed, model based clustering is added to the mixture model example, Bayesian approach is now illustrated with the genetics exampl

The scientific basis of professional music education

The article presents the research bases for the development of student science, the results of the analysis of the creative function of the performer and teacher, the role of the scientific work of the musician-performerОсвещены результаты анализа творческой функции исполнителя и педагога, роль научной работы музыканта-исполнител

Possibilities and features of zero-ischemia nephron-sparing surgery in localized kidney cancer

Kidney cancer (KCa) is one of the greatest challenges in oncological urology due to the increase in morbidity and mortality rates annually. In the treatment of KCa, preservation of renal function is an important objective, in addition to achieving oncological results. The article presents the experience of treatment of 175 KCa-patients of pT1a – T2aN0M0 stages, who underwent nephron-saving surgery (NSS) with preventive hemostatic sutures. Functional outcomes of NSS were studied in the groups without cross-linking (group 1; n = 150) and with cross-linking of the renal pedicle (group 2; n = 25). Kidney resection with prophylactic suturing has been shown to allow removal of a tumour of almost any localisation. By avoiding cross-linking of the renal pedicle during surgery, post-ischemic changes in the renal parenchyma are minimised. Thus, one month after surgery, the perfusion indexes in groups 1 & 2 were 45.2 ± 3.0% vs 35.5 ± 3.3%; renal indexes were 44.8 ± 2.4% vs 39.1 ± 1.4%; areas of the functioning parenchyma were 52.0 ± 10.0% vs 35.0 ± 9.0%, respectively

Application of geographic information systems to analyze the activities of educational organizations

The article discusses the possibility of using geographic information systems (GIS) in solving the problems of education management, describes the requirements for the design and functions of GIS, describes the layout of GIS for territorial analysis of the results activities of universitiesВ статье рассмотрены возможности использования геоинформационных систем (ГИС) в решении задач управления образованием, описаны требования к разработке и функции ГИС, приведено описание макета геоинформационной системы, предназначенной для территориального анализа результатов деятельности вузо

Formation of information-analytical materials on the results of the monitoring efficiency of higher education schools

The article discusses the main aspects of the formation of information-analytical materials on the basis of verified statistical information in the framework of the expert-analytical support for monitoring the effectiveness of higher education schoolsВ статье рассмотрены основные аспекты формирования информационно-аналитических материалов на основе верифицированной статистической информации в рамках экспертно-аналитического сопровождения проведения мониторинга эффективности деятельности образовательных организаций высшего образовани

Correlation Time-of-flight Spectrometry of Ultracold Neutrons

The fearures of the correlation method used in time-of-flight spectrometry of ultracold neutrons are analyzed. The time-of-flight spectrometer for the energy range of ultracold neutrons is described, and results of its testing by measuring spectra of neutrons passing through interference filters are presented.Comment: 16 pages, 5 figure

Prognosis of recurrent myocardial infarction based on shortliffe fuzzy models using the electrical characteristics of biologically active points

This report discusses the employment of the electrical characteristics of biologically active points (BAP) in the meridian of the heart to solve the task of prognosticating recurrence of myocardial infarctions during the rehabilitation period using fuzzy decision rule

Определение полисорбата 80 в биофармацевтических препаратах с помощью оптимизированной колориметрической методики

Objectives. We hereby describe an improvement of a previously developed quantification technique for polysorbate 80 in biopharmaceutical formulations (darbepoetin alfa and eculizumab) and report the validation of the new approach.Methods. Polysorbate was isolated from analyte samples by protein precipitation using an organic solvent, followed by supernatant evaporation in vacuum. Polysorbate was derivatized using a ferric thiocyanate reagent and extracted into an organic phase; the relevant optical density measurements were performed.Results. We established the optimal conditions for each step of the analysis procedure. The accuracy was 97–102% in the tested analytical range, the relative standard deviation did not exceed 5%, and the limit of quantification was 0.01 mg/mL.Conclusions. The reported approach is highly sensitive; polysorbate isolation and quantification do not depend on the matrix or, most importantly, the protein.Цели. В данной работе была усовершенствована ранее разработанная методика определения полисорбата 80 в биотехнологических препаратах (дарбэпоэтин альфа, экулизумаб), а также проведена ее валидация.Методы. Полисорбат извлекали из пробы осаждением белка органическим растворителем, затем выпаривали супернатант в вакууме. Полисорбат дериватизировали оптимизированным железо–тиоцианатным реагентом; дериват экстрагировали в слой органического растворителя и измеряли оптическую плотность.Результаты. Были установлены оптимальные условия для каждой стадии методики. Правильность находится в диапазоне степени извлечения 97–102%, относительное стандартное отклонение составляет не более 5%, предел количественного определения методики 0.01 мг/мл.Выводы. Представленная методика имеет высокую чувствительность. Извлечение и определение полисорбата не зависят от матрикса пробы – прежде всего, от присутствующего белка