22 research outputs found

    Complete directed minors and chromatic number

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    The dichromatic number χ→(D) of a digraph D is the smallest k for which it admits a k-coloring where every color class induces an acyclic subgraph. Inspired by Hadwiger's conjecture for undirected graphs, several groups of authors have recently studied the containment of complete directed minors in digraphs with a given dichromatic number. In this note we exhibit a relation of these problems to Hadwiger's conjecture. Exploiting this relation, we show that every directed graph excluding the complete digraph K↔t of order t as a strong minor or as a butterfly minor is O(t(log log t)6)-colorable. This answers a question by Axenovich, Girão, Snyder, and Weber, who proved an upper bound of t4t for the same problem. A further consequence of our results is that every digraph of dichromatic number 22n contains a subdivision of every n-vertex subcubic digraph, which makes progress on a set of problems raised by Aboulker, Cohen, Havet, Lochet, Moura, and Thomassé

    Az autoimmun thyreoiditis, a kétoldali papillaris pajzsmirigy-carcinoma, a nyaki thyreolipoma és a diabetes mellitus együttes előfordulása = Combined presentation of autoimmune thyroiditis, bilateral papillary thyroid carcinoma, cervical thyrolipoma and diabetes mellitus

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    Absztrakt: A thyreolipoma, vagy pajzsmirigy-adenolipoma a pajzsmirigy-adenoma egy extrém ritka formája, mely kötőszövetes tokkal borított érett zsírszövetet és folliculusokat is tartalmaz. Az 52 éves női cukorbetegünk növekvő nyaki teriméjének esetét mutatjuk be, mely totális thyreoidectomia során eltávolításra került. A pajzsmirigy hisztopatológiai vizsgálata autoimmun thyreoiditist, kétoldali papillaris carcinomát és lefűződött nyaki thyreolipomát igazolt. Orv Hetil. 2018; 159(25): 1024–1032. | Abstract: Thyrolipoma or thyroid adenolipoma is an extremely rare form of thyroid adenoma, which also contains mature adipose tissue and follicles covered with fibrous capsule. We present the case of the growing cervical lesion of a 52-year-old female with diabetes, which was removed during total thyreoidectomy. Autoimmune thyroiditis, bilateral papillary carcinoma and cervical thyrolipoma have been identified by the histopathological examination of the thyroid gland. Orv Hetil. 2018; 159(25): 1024–1032

    The combination of a genome-wide association study of lymphocyte count and analysis of gene expression data reveals novel asthma candidate genes

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    Recent genome-wide association studies (GWAS) have identified a number of novel genetic associations with complex human diseases. In spite of these successes, results from GWAS generally explain only a small proportion of disease heritability, an observation termed the ‘missing heritability problem’. Several sources for the missing heritability have been proposed, including the contribution of many common variants with small individual effect sizes, which cannot be reliably found using the standard GWAS approach. The goal of our study was to explore a complimentary approach, which combines GWAS results with functional data in order to identify novel genetic associations with small effect sizes. To do so, we conducted a GWAS for lymphocyte count, a physiologic quantitative trait associated with asthma, in 462 Hutterites. In parallel, we performed a genome-wide gene expression study in lymphoblastoid cell lines from 96 Hutterites. We found significant support for genetic associations using the GWAS data when we considered variants near the 193 genes whose expression levels across individuals were most correlated with lymphocyte counts. Interestingly, these variants are also enriched with signatures of an association with asthma susceptibility, an observation we were able to replicate. The associated loci include genes previously implicated in asthma susceptibility as well as novel candidate genes enriched for functions related to T cell receptor signaling and adenosine triphosphate synthesis. Our results, therefore, establish a new set of asthma susceptibility candidate genes. More generally, our observations support the notion that many loci of small effects influence variation in lymphocyte count and asthma susceptibility

    The validation of the Hungarian version of the ID-migraine questionnaire

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    Despite its high prevalence, migraine remains underdiagnosed and undertreated. ID-Migraine is a short, self-administrated questionnaire, originally developed in English by Lipton et al. and later validated in several languages. Our goal was to validate the Hungarian version of the ID-Migraine Questionnaire.Patients visiting two headache specialty services were enrolled. Diagnoses were made by headache specialists according to the ICHD-3beta diagnostic criteria. There were 309 clinically diagnosed migraineurs among the 380 patients. Among the 309 migraineurs, 190 patients had only migraine, and 119 patients had other headache beside migraine, namely: 111 patients had tension type headache, 3 patients had cluster headache, 4 patients had medication overuse headache and one patient had headache associated with sexual activity also. Among the 380 patients, 257 had only a single type headache whereas 123 patients had multiple types of headache. Test-retest reliability of the ID-Migraine Questionnaire was studied in 40 patients.The validity features of the Hungarian version of the ID-Migraine questionnaire were the following: sensitivity 0.95 (95% CI, 0.92-0.97), specificity 0.42 (95% CI, 0.31-0.55), positive predictive value 0.88 (95% CI, 0.84-0.91), negative predictive value 0.65 (95% CI, 0.5-0.78), missclassification error 0.15 (95% CI, 0.12-0.19). The kappa coefficient of the questionnaire was 0.77.The Hungarian version of the ID-Migraine Questionnaire had adequate sensitivity, positive predictive value and misclassification error, but a low specificity and somewhat low negative predictive value

    Complete directed minors and chromatic number

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    The dichromatic number χ(D)\overrightarrow{\chi }(D) of a digraph DD is the smallest kk for which it admits a kk-coloring where every color class induces an acyclic subgraph. Inspired by Hadwiger's conjecture for undirected graphs, several groups of authors have recently studied the containment of complete directed minors in digraphs with a given dichromatic number. In this note we exhibit a relation of these problems to Hadwiger's conjecture. Exploiting this relation, we show that every directed graph excluding the complete digraph Kt{\overleftrightarrow{K}}_{t} of order tt as a strong minor or as a butterfly minor is O(t{(\mathrm{log}\unicode{x0200A}\mathrm{log}\unicode{x0200A}t)}^{6})-colorable. This answers a question by Axenovich, Girao, Snyder, and Weber, who proved an upper bound of t4tt{4}{t} for the same problem. A further consequence of our results is that every digraph of dichromatic number 22n22n contains a subdivision of every nn-vertex subcubic digraph, which makes progress on a set of problems raised by Aboulker, Cohen, Havet, Lochet, Moura, and Thomasse.ISSN:0364-9024ISSN:1097-011
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