1,720,965 research outputs found
The Fragile X Syndrome in Mentally Retarded Patients from Latvia. Summary of the Doctoral Thesis
No full textPromocijas darbs izstrādāts: VSIA Bērnu klīniskā universitātes slimnīca, Medicīniskās ģenētikas klīnika. Aizstāvēšana: 2011. gada 21. decembrī plkst. 14.00 Rīgas Stradiņa universitātes Teorētiskās medicīnas promocijas padomes atklātā sēdē Rīgā, Dzirciema ielā 16, Hipokrāta auditorijā.Garīgā atpalicība (GA) ir komplekss fenotips, kurš skar vidēji 2 - 3% populācijas. Ceturtajai daļai gadījumu pamatā ir ģenētiska saslimšana. Garīgā atpalicība ir biežākais iemesls smagai bērna invaliditātei. Mūsu pētījums tika vērsts uz trauslās X hromosomas sindromu (FXS), labi zināmu un biežu ar X hromosomu saistītas garīgas atpalicības iemeslu. Trauslās X hromosomas sindroma prevalences noteikšana kopējā Latvijas vīriešu populācijā bija viens no galvenajiem mūsu pētījuma uzdevumiem. Prevalence noteikta retrospektīvā pētījumā vīriešiem ar garīgo atpalicību un attīstības aizturi, diagnosticētiem desmit gadu periodā. Trauslās X hromosomas sindroma prevalence kopējā Latvijas vīriešu populācijā noteikta 1/6428 (95% CI 5538-7552) vai 15,55/100000 vīriešu (95% CI 13,24 – 18,05). Trauslās X hromosomas sindroma iemesls ir palielināts CGG atkārtojumu skaits (pilna mutācija > 200 atkārtojumiem) FMR1 gēna 5` galā. Šajā pētījumā mēs raksturojām CGG atkārtojumu sadalījumu un struktūru X hromosomām ar normālu CGG atkārtojumu skaitu un hromosomām ar pilnu mutāciju. Mēs analizējām jau iepriekš aprakstītus, ar FMR1 gēnu saistītus mikrosatelītu marķierus FRAXAC1, FRAXAC2 un DXS548, kā arī vienu SNP - ATL1, kuri atrodas 150 kb attālumā ap FMR1 gēna CGG atkārtojumu rajonu. Mikrosatelītu un viena nukleotīda polimorfisma marķieri secīgi apvienoti haplotipos: DXS548-FRAXAC1-ATL1-FRAXAC2. Balstoties uz DNS izpēti X hromosomām ar normālu CGG atkārtojumu skaitu noteicām, ka biežāk sastopamās alēles ir: 30 (29,95%), 31 (13,10%) un 29 (12,83%). Statistiski ticama saistība ar ATL1 SNP polimorfismu konstatēta: 29 CGG atkārtojumiem ar G (p = 0,001); 30 CGG atkārtojumiem ar A (p < 0,0001); 31 CGG atkārtojumam ar A (p = 0,0013). Konstatēta polimorfisma G asociācija ar pelākās zonas CGG alēlēm (p = 0,0271) un saistība ar visām FXS alēlēm. Pelēkās zonas alēļu struktūras analīze liecina, ka haplotips 7-4-A-5+ iespējams ir “aizsargājošais” haplotips CGG atkārtojumu skaita stabilitātei. Ar FMR1 gēna saistīto haplotipu gadījuma-kontroles pētījuma rezultāti ticami norāda uz haplotipa 2-2-G-4 saistību ar CGG atkārtojumu nestabilitāti Latvijas populācijā. AMOVA rezultāti pierādīja atšķirīgu ģenētisko izcelsmi FXS hromosomām. Šis ir pirmais pētījums Baltijas valstīs veltīts ar FMR1 gēnu saistītiem haplotipiem. Mūsu pētījuma rezultāti atklāj pierādījumus atšķirīgam CGG atkārtojumu skaita mutācijas ceļam Ziemeļaustrumeiropā.Promocijas darbs veikts ar Eiropas Sociālā fonda projekta “Atbalsts doktorantiem studiju programmas apguvei un zinātniskā grāda ieguvei Rīgas Stradiņa universitātē” finansiālu atbalst
Trauslās X hromosomas sindroms pacientiem ar garīgo atpalicību Latvijā. Promocijas darbs
No full textElaboration of the Study: Medical Genetics Clinic, University Children`s Hospital, Riga, Latvia. Defence: on 21st of December, 2011 at 14.00 o`clock in the Hippocratic lecture-hall of Riga Stradins University (RSU) Dzirciema Str.16.Mental retardation (MR) is a complex phenotype, affecting 2 - 3% of the general population. A quarter of cases are caused by genetic disorders. Mental retardation is the most frequent cause of severe handicap in children. We focussed our study on fragile X syndrome, which is both well known and a common cause of X-linked mental retardation. One of principle tasks in our study was to estimate the prevalence of fragile X syndrome (FXS) in the entire Latvian male population. In the prevalence study we analysed retrospective data of the male individuals with mental retardation and developmental disabilities, diagnosed in ten years time. The prevalence of fragile X syndrome in the Latvian male population was estimated to be 1/6428 (95% CI 5538 – 7552) or 15.55/100 000 males (95% CI 13.24 – 18.05). Fragile X syndrome is caused by an expanded CGG repeat (> 200 units, full mutation) at the 5' end of the FMR1 gene. In our study we characterised the distribution and structure of CGG repeats among X chromosomes with normal CGG repeat alleles and chromosomes with full mutation. We analysed elsewhere described FMR1 gene linked STR based markers FRAXAC1, FRAXAC2 and DXS548, and one SNP based marker ATL1, found within 150 kb of the FMR1 CGG repeat. STR and SNP marker haplotypes were combined as follows: DXS548-FRAXAC1-ATL1-FRAXAC2. DNA studies of X chromosomes with normal CGG repeats revealed high incidences of allele 30 (29.95%), allele 31 (13.10%) and allele 29 (12.83%). A statistically significant association with ATL1 SNP was found in following cases: allele 29 and G (p = 0.001); allele 30 and A (p < 0.0001) and allele 31 with A (p = 0.0013). Polymorphism G was found to be associated with grey-zone CGG alleles (p = 0.0271) and exclusively associated with all FXS alleles. A structure analysis of grey-zone alleles suggest haplotype 7-4-A-5+ as a “protective” haplotype for CGG tract stability. The case-control study results also imply that in the Latvian population, haplotype 2-2-G-4 is a marker of CGG tract instability. Results of AMOVA for haplotypes revealed distinct genetic background for FXS chromosomes. This is the first study regarding FMR1 linked haplotypes in the Baltic States region. Our results provide evidence of different mutational pathways of CGG repeat expansion in North-Eastern Europe.The financial support of the study: Project "Genomic studies of the Latvian population, their application for diagnosis and prevention of human pathology". Supported by the Latvian Council of Science, "Elaboration of Phenylketonuria prenatal and fragile X Syndrome prenatal, postnatal DNA-based testing and quality control system in Latvia" (2000-2004); ESF project No. 2004/0005/VPD1/ESF/PIAA/04/NP/3.2.3.1./0001/0004 /0066. "Enhancement of competencies, qualification and skills of health care and health promotion professionals", (2005-2008); Latvian National Research Programme in Medicine, "Multi-disciplinary research consortium on major pathologies threatening the life expectancy and quality of life of the Latvian population". Project No. 6, "Development of early diagnostics, prevention and treatment in children diseases", (2006–2009); ESF project No. 2009/0147/1DP/1.1.2.1.2/09/IPIA/VIAA/009 "Enhancement of competencies, qualification and skills of health care and health promotion professionals" Sub-activity No 1.1.2.1.2 "Support to doctor’s studies", (2011)
Trauslās X hromosomas sindroms pacientiem ar garīgo atpalicību Latvijā. Promocijas darba kopsavilkums
No full textElaboration of the Study: Medical Genetics Clinic, University Children`s Hospital, Riga, Latvia. Defence: on 21st of December, 2011 at 14.00 o`clock in the Hippocratic lecture-hall of Riga Stradins University (RSU) Dzirciema Str.16.Mental retardation (MR) is a complex phenotype, affecting 2 - 3% of the general population. A quarter of cases are caused by genetic disorders. Mental retardation is the most frequent cause of severe handicap in children. We focussed our study on fragile X syndrome, which is both well known and a common cause of X-linked mental retardation. One of principle tasks in our study was to estimate the prevalence of fragile X syndrome (FXS) in the entire Latvian male population. In the prevalence study we analysed retrospective data of the male individuals with mental retardation and developmental disabilities, diagnosed in ten years time. The prevalence of fragile X syndrome in the Latvian male population was estimated to be 1/6428 (95% CI 5538 – 7552) or 15.55/100 000 males (95% CI 13.24 – 18.05). Fragile X syndrome is caused by an expanded CGG repeat (> 200 units, full mutation) at the 5' end of the FMR1 gene. In our study we characterised the distribution and structure of CGG repeats among X chromosomes with normal CGG repeat alleles and chromosomes with full mutation. We analysed elsewhere described FMR1 gene linked STR based markers FRAXAC1, FRAXAC2 and DXS548, and one SNP based marker ATL1, found within 150 kb of the FMR1 CGG repeat. STR and SNP marker haplotypes were combined as follows: DXS548-FRAXAC1-ATL1-FRAXAC2. DNA studies of X chromosomes with normal CGG repeats revealed high incidences of allele 30 (29.95%), allele 31 (13.10%) and allele 29 (12.83%). A statistically significant association with ATL1 SNP was found in following cases: allele 29 and G (p = 0.001); allele 30 and A (p < 0.0001) and allele 31 with A (p = 0.0013). Polymorphism G was found to be associated with grey-zone CGG alleles (p = 0.0271) and exclusively associated with all FXS alleles. A structure analysis of grey-zone alleles suggest haplotype 7-4-A-5+ as a “protective” haplotype for CGG tract stability. The case-control study results also imply that in the Latvian population, haplotype 2-2-G-4 is a marker of CGG tract instability. Results of AMOVA for haplotypes revealed distinct genetic background for FXS chromosomes. This is the first study regarding FMR1 linked haplotypes in the Baltic States region. Our results provide evidence of different mutational pathways of CGG repeat expansion in North-Eastern Europe.The work was supported by ESF Project “Support to doctor’s studies and acquiring an academic degree in Riga Stradins University” No. 2009/ 0147/1DP/ 1.1.2.1.2/ 09/ IPIA/ VIAA/ 00
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
- …
