219 research outputs found

    Tuning Numeric Parameters to Troubleshoot a Telephone-Network Loop

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    The Nynex Max expert system analyzes the result of an automated electric test on a telephone line and determines the type of problem. However, tuning the system\u27s parameter values can be difficult. The Opti-Max system can automatically set these parameters by analyzing decisions made by experts who troubleshoot problem

    A fresh look at introductory data science

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    The proliferation of vast quantities of available datasets that are large and complex in nature has challenged universities to keep up with the demand for graduates trained in both the statistical and the computational set of skills required to effectively plan, acquire, manage, analyze, and communicate the findings of such data. To keep up with this demand, attracting students early on to data science as well as providing them a solid foray into the field becomes increasingly important. We present a case study of an introductory undergraduate course in data science that is designed to address these needs. Offered at Duke University, this course has no pre-requisites and serves a wide audience of aspiring statistics and data science majors as well as humanities, social sciences, and natural sciences students. We discuss the unique set of challenges posed by offering such a course and in light of these challenges, we present a detailed discussion into the pedagogical design elements, content, structure, computational infrastructure, and the assessment methodology of the course. We also offer a repository containing all teaching materials that are open-source, along with supplemental materials and the R code for reproducing the figures found in the paper

    An integrative approach to identify hexaploid wheat miRNAome associated with development and tolerance to abiotic stress

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    Background: Wheat is a major staple crop with broad adaptability to a wide range of environmental conditions.This adaptability involves several stress and developmentally responsive genes, in which microRNAs (miRNAs) have emerged as important regulatory factors. However, the currently used approaches to identify miRNAs in this\ud polyploid complex system focus on conserved and highly expressed miRNAs avoiding regularly those that are often lineage-specific, condition-specific, or appeared recently in evolution. In addition, many environmental and biological factors affecting miRNA expression were not yet considered, resulting still in an incomplete repertoire of wheat miRNAs.\ud Results: We developed a conservation-independent technique based on an integrative approach that combines machine learning, bioinformatic tools, biological insights of known miRNA expression profiles and universal criteria of plant miRNAs to identify miRNAs with more confidence. The developed pipeline can potentially identify novel wheat miRNAs that share features common to several species or that are species specific or clade specific. It allowed the discovery of 199 miRNA candidates associated with different abiotic stresses and development stages. We also highlight from the raw data 267 miRNAs conserved with 43 miRBase families. The predicted miRNAs are highly associated with abiotic stress responses, tolerance and development. GO enrichment analysis showed that they may play biological and physiological roles associated with cold, salt and aluminum (Al) through auxin signaling pathways, regulation of gene expression, ubiquitination, transport, carbohydrates, gibberellins, lipid, glutathione and secondary metabolism, photosynthesis, as well as floral transition and flowering.\ud Conclusion: This approach provides a broad repertoire of hexaploid wheat miRNAs associated with abiotic stress responses, tolerance and development. These valuable resources of expressed wheat miRNAs will help in elucidating the regulatory mechanisms involved in freezing and Al responses and tolerance mechanisms as well as for development and flowering. In the long term, it may help in breeding stress tolerant plants

    Визначення показань та протипоказань до симультанних оперативних втручань у пацієнтів з поєднанням ендокринної та іншої хірургічної патології

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    The aim of the work: to develop indications and contraindications for the implementation of simultaneous surgical interventions on the example of patients with combined pathology of the thyroid gland (TG) and cholelithiasis (CL) / gallbladder polyposis, using the scale of the functional state of P-POSSUM. Materials and Methods. During the period from January 2015 to September 2018, 35 patients with combined pathology of the TG and CL / gallbladder polyposis were examined and operated. At the preoperative stage, as well as on the first day of the postoperative period, all patients evaluated on the P-POSSUM scale. Results and Discussion. In 22 (62.9 %) patients, whose functional state before the intervention was assessed by physiological subscale (FS) ≤ 17 points, there were postoperative changes in health with an average difference of 0.13 points, T (Z) = 1.21, p = 0.225. In all these patients, the complexity of surgical intervention on the surgical sub-scale (SS) on the P-POSSUM scale was estimated ≤ 14 points. In 13 (37.1 %) patients, whose condition was estimated at 17 points by FS, significant changes in functional health before and after surgery were revealed, with a difference of average 1.15 points, T (Z) = 2.67; p = 0.0077. The complexity of their operations ranged from 14 to 16 points for SS.Цель работы: разработать показания и противопоказания к выполнению симультанных оперативных вмешательств на примере пациентов с сочетанной патологией щитовидной железы (ЩЖ) и желчнокаменной болезнью (ЖКБ) / полипозом желчного пузыря, с использованием шкалы функционального состояния P-POSSUM. Материалы и методы. За период с января 2015 по сентябрь 2018 года обследовано и прооперировано 35 пациентов с сочетанной патологией щитовидной железы и ЖКБ / полипозом желчного пузыря. На дооперационном этапе, а также на первые сутки послеоперационного периода, всем пациентам проводили оценку функционального состояния по шкале P-POSSUM. Результаты исследований и их обсуждение. У 22 (62,9 %) пациентов, функциональное состояние которых до вмешательства оценивалось по физиологической субшкале (ФС) ≤ 17 баллов, имели место послеоперационные изменения состояния здоровья с разницей средних 0,13 баллов, Т (Z) = 1,21, р = 0,225. В этих больных сложность оперативного вмешательства по хирургической субшкале (ХС) шкале P-POSSUM была оценена ≤ 14 баллов. У 13 (37,1 %) больных, состояние которых было оценено в 17 баллов по ФС, выявлены значимые изменения функционального состояния здоровья до и после операции, с разницей средних 1,15 балла, Т (Z) = 2,67; р = 0,0077. Сложность операций у них колебалась от 14 до 16 баллов за ХС.Мета роботи: розробити показання та протипоказання до виконання симультанних оперативних втручань на прикладі пацієнтів з поєднаною патологією щитоподібної залози (ЩЗ) та жовчнокам’яною хворобою (ЖКХ) / поліпозом жовчного міхура, з використанням шкали функціонального стану P-POSSUM. Матеріали і методи. За період з січня 2015 до вересня 2018 року обстежено та прооперовано 35 пацієнтів з поєднаною патологією щитоподібної залози та ЖКХ / поліпозом жовчного міхура. На доопераційному етапі, а також на першу добу післяопераційного періоду всім пацієнтам проводили оцінку функціонального стану за шкалою P-POSSUM. Результати досліджень та їх обговорення. У 22 (62,9 %) пацієнтів, функціональний стан яких до втручання оцінювався за фізіологічною субшкалою (ФС) ≤ 17 балів, мали місце післяопераційні зміни стану здоров’я з різницею середніх 0,13 бала, Т (Z) = 1,21, р = 0,225. У всіх цих хворих складність оперативного втручання за хірургічною субшкалою (ХС) шкали P-POSSUM була оцінена ≤ 14 балів. У 13 (37,1 %) хворих, стан яких був оцінений в ˃ 17 балів за ФС, виявлені значущі зміни функціонального стану здоров’я до та після операції з різницею середніх 1,15 бала, Т (Z) = 2,67; р = 0,0077. Складність операцій у них коливалася від 14 до 16 балів за ХС

    Построение диагностической модели сложного объекта диагностирования на основе минимизации множества вероятностно-лингвистических синдромов

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    The probabilistic-linguistic approach to the representation and transformation of the fuzzy information allows to show how to solve the problem of building types of numerous probabilistic-linguistic syndromes characterizing all possible technical conditions of complex object for diagnostics.На основе вероятностно-лингвистического подхода к представлению и преобразованию нечеткой информации показан порядок решения задачи типизации сформированного экспертами множества вероятностно-лингвистических синдромов, характеризующих все возможные технические состояния сложного объекта диагностирования

    Comparative expression of Cbf genes in the Triticeae under different acclimation induction temperatures

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    In plants, the C-repeat binding factors (Cbfs) are believed to regulate low-temperature (LT) tolerance. However, most functional studies of Cbfs have focused on characterizing expression after an LT shock and have not quantified differences associated with variable temperature induction or the rate of response to LT treatment. In the Triticeae, rye (Secale cereale L.) is one of the most LT-tolerant species, and is an excellent model to study and compare Cbf LT induction and expression profiles. Here, we report the isolation of rye Cbf genes (ScCbfs) and compare their expression levels in spring- and winter-habit rye cultivars and their orthologs in two winter-habit wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) cultivars. Eleven ScCbfs were isolated spanning all four major phylogenetic groups. Nine of the ScCbfs mapped to 5RL and one to chromosome 2R. Cbf expression levels were variable, with stronger expression in winter- versus spring-habit rye cultivars but no clear relationship with cultivar differences in LT, down-stream cold-regulated gene expression and Cbf expression were detected. Some Cbfs were expressed only at warmer acclimation temperatures in all three species and their expression was repressed at the end of an 8-h dark period at warmer temperatures, which may reflect a temperature-dependent, light-regulated diurnal response. Our work indicates that Cbf expression is regulated by complex genotype by time by induction–temperature interactions, emphasizing that sample timing, induction–temperature and light-related factors must receive greater consideration in future studies involving functional characterization of LT-induced genes in cereals

    Effects of photo and thermo cycles on flowering time in barley: a genetical phenomics approach

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    The effects of synchronous photo (16 h daylength) and thermo (2 °C daily fluctuation) cycles on flowering time were compared with constant light and temperature treatments using two barley mapping populations derived from the facultative cultivar ‘Dicktoo’. The ‘Dicktoo’בMorex’ (spring) population (DM) segregates for functional differences in alleles of candidate genes for VRN-H1, VRN-H3, PPD-H1, and PPD-H2. The first two loci are associated with the vernalization response and the latter two with photoperiod sensitivity. The ‘Dicktoo’בKompolti korai’ (winter) population (DK) has a known functional polymorphism only at VRN-H2, a locus associated with vernalization sensitivity. Flowering time in both populations was accelerated when there was no fluctuating factor in the environment and was delayed to the greatest extent with the application of synchronous photo and thermo cycles. Alleles at VRN-H1, VRN-H2, PPD-H1, and PPD-H2—and their interactions—were found to be significant determinants of the increase/decrease in days to flower. Under synchronous photo and thermo cycles, plants with the Dicktoo (recessive) VRN-H1 allele flowered significantly later than those with the Kompolti korai (recessive) or Morex (dominant) VRN-H1 alleles. The Dicktoo VRN-H1 allele, together with the late-flowering allele at PPD-H1 and PPD-H2, led to the greatest delay. The application of synchronous photo and thermo cycles changed the epistatic interaction between VRN-H2 and VRN-H1: plants with Dicktoo type VRN-H1 flowered late, regardless of the allele phase at VRN-H2. Our results are novel in demonstrating the large effects of minor variations in environmental signals on flowering time: for example, a 2 °C thermo cycle caused a delay in flowering time of 70 d as compared to a constant temperature

    The CBF gene family in hexaploid wheat and its relationship to the phylogenetic complexity of cereal CBFs

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    Most temperate plants tolerate both chilling and freezing temperatures whereas many species from tropical regions suffer chilling injury when exposed to temperatures slightly above freezing. Cold acclimation induces the expression of cold-regulated genes needed to protect plants against freezing stress. This induction is mediated, in part, by the CBF transcription factor family. To understand the evolution and function of this family in cereals, we identified and characterized 15 different CBF genes from hexaploid wheat. Our analyses reveal that wheat species, T. aestivum and T. monococcum, may contain up to 25 different CBF genes, and that Poaceae CBFs can be classified into 10 groups that share a common phylogenetic origin and similar structural characteristics. Six of these groups (IIIc, IIId, IVa, IVb, IVc and IVd) are found only in the Pooideae suggesting they represent the CBF response machinery that evolved recently during colonization of temperate habitats. Expression studies reveal that five of the Pooideae-specific groups display higher constitutive and low temperature inducible expression in the winter cultivar, and a diurnal regulation pattern during growth at warm temperature. The higher constitutive and inducible expression within these CBF groups is an inherited trait that may play a predominant role in the superior low temperature tolerance capacity of winter cultivars and possibly be a basis of genetic variability in freezing tolerance within the Pooideae subfamily

    Development of a Model System to Identify Differences in Spring and Winter Oat

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    Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the field in south- and western Sweden. By assaying for winter survival and agricultural properties during four consecutive seasons, we identified 14 breeding lines of different origins that not only survived the winter but also were agronomically better than the rest. Laboratory tests including electrolytic leakage, controlled crown freezing assay, expression analysis of the AsVrn1 gene and monitoring of flowering time suggested that the American lines had the highest freezing tolerance, although the German lines performed better in the field. Finally, six lines constituting the two most freezing tolerant lines, two intermediate lines and two spring cultivars were chosen to build a winter oat model system. Metabolic profiling of non-acclimated and cold acclimated leaf tissue samples isolated from the six selected lines revealed differential expression patterns of 245 metabolites including several sugars, amino acids, organic acids and 181 hitherto unknown metabolites. The expression patterns of 107 metabolites showed significant interactions with either a cultivar or a time-point. Further identification, characterisation and validation of these metabolites will lead to an increased understanding of the cold acclimation process in oats. Furthermore, by using the winter oat model system, differential sequencing of crown mRNA populations would lead to identification of various biomarkers to facilitate winter oat breeding
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