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Sample records for chromosome fragility

  1. Chromosome fragility in Freemartin cattle

    Directory of Open Access Journals (Sweden)

    V. Barbieri

    2010-04-01

    Full Text Available The aim of the present study was to verify chromosome fragility in freemartin cattle using chromosome aberration (CA and sister chromatid exchange (SCE tests. A total of eighteen co-twins were investigated. Fourteen animals were identified as cytogenetically chimeric (2n=60, XX/XY while 4 were classified as normal. Freemartin cattle showed a higher percentage of aneuploid cells (18.64% and highly significant statistical differences (P < 0.001 in mean values of gaps (4.53 ± 2.05, chromatid breaks (0.26 ± 0.51, and significant statistical differences (P < 0.005 in mean values of chromosome breaks (0.12 ± 0.43 when compared to 10 control animals from single births (aneuploid cells, 11.20%; gaps, 2.01 ± 1.42; chromatid breaks, 0.05 ± 0.22; chromosome breaks, 0.02 ± 0.14.

  2. Fragile site X chromosomes in mentally retarded boys.

    OpenAIRE

    Moon, H. R.; Moon, S. Y.

    1993-01-01

    The fragile X syndrome is a common X-linked mental retardation and autism, affecting females as well as males. The fragile site X chromosomes were studied in a series of 153 mentally retarded boys of unknown etiology to determine the frequency of fragile X syndrome, and to assess the feasibility of making a clinical diagnosis of the fragile X syndrome in young boys before cytogenetic results were known. The 10 boys (6.4%) were positive for fra (X) (q27). The phenotype of fra (X) (q27) positiv...

  3. The fragile Y hypothesis: Y chromosome aneuploidy as a selective pressure in sex chromosome and meiotic mechanism evolution.

    Science.gov (United States)

    Blackmon, Heath; Demuth, Jeffery P

    2015-09-01

    Loss of the Y-chromosome is a common feature of species with chromosomal sex determination. However, our understanding of why some lineages frequently lose Y-chromosomes while others do not is limited. The fragile Y hypothesis proposes that in species with chiasmatic meiosis the rate of Y-chromosome aneuploidy and the size of the recombining region have a negative correlation. The fragile Y hypothesis provides a number of novel insights not possible under traditional models. Specifically, increased rates of Y aneuploidy may impose positive selection for (i) gene movement off the Y; (ii) translocations and fusions which expand the recombining region; and (iii) alternative meiotic segregation mechanisms (achiasmatic or asynaptic). These insights as well as existing evidence for the frequency of Y-chromosome aneuploidy raise doubt about the prospects for long-term retention of the human Y-chromosome despite recent evidence for stable gene content in older non-recombining regions. PMID:26200104

  4. Estimating tempo and mode of Y chromosome turnover: explaining Y chromosome loss with the fragile Y hypothesis.

    Science.gov (United States)

    Blackmon, Heath; Demuth, Jeffery P

    2014-06-01

    Chromosomal sex determination is phylogenetically widespread, having arisen independently in many lineages. Decades of theoretical work provide predictions about sex chromosome differentiation that are well supported by observations in both XY and ZW systems. However, the phylogenetic scope of previous work gives us a limited understanding of the pace of sex chromosome gain and loss and why Y or W chromosomes are more often lost in some lineages than others, creating XO or ZO systems. To gain phylogenetic breadth we therefore assembled a database of 4724 beetle species' karyotypes and found substantial variation in sex chromosome systems. We used the data to estimate rates of Y chromosome gain and loss across a phylogeny of 1126 taxa estimated from seven genes. Contrary to our initial expectations, we find that highly degenerated Y chromosomes of many members of the suborder Polyphaga are rarely lost, and that cases of Y chromosome loss are strongly associated with chiasmatic segregation during male meiosis. We propose the "fragile Y" hypothesis, that recurrent selection to reduce recombination between the X and Y chromosome leads to the evolution of a small pseudoautosomal region (PAR), which, in taxa that require XY chiasmata for proper segregation during meiosis, increases the probability of aneuploid gamete production, with Y chromosome loss. This hypothesis predicts that taxa that evolve achiasmatic segregation during male meiosis will rarely lose the Y chromosome. We discuss data from mammals, which are consistent with our prediction. PMID:24939995

  5. Cosegregation of hypertrophic cardiomyopathy and a fragile site on chromosome 16 in a large Italian family.

    OpenAIRE

    M. Ferraro; Scarton, G; Ambrosini, M

    1990-01-01

    We studied the karyotypes of 10 members of a family in whom hypertrophic cardiomyopathy is segregating as an autosomal dominant trait. In all those affected by the disease, a fragile site on the long arm of chromosome 16 was found, expressed with different frequencies, but the unaffected family members did not show this trait.

  6. Chromosomal fragility syndrome and family history of radiosensitivity as indicators for radiotherapy dose modification

    International Nuclear Information System (INIS)

    Beside a few known radiosensitive syndromes, a patient's reaction to radiotherapy is difficult to predict. In this report we describe the management of a pediatric cancer patient presented with a family history of radiosensitivity and cancer proneness. Laboratory investigations revealed a chromosomal fragility syndrome and an increased cellular radiosensitivity in vitro. AT gene sequencing revealed no mutations. The patient was treated with reduced radiation doses to avoid the presumed increased risks of toxicity to normal tissues. The patient tolerated well the treatment with no significant acute or late radiation sequelae. Five years later, the patient remains both disease and complications free. While an accurate laboratory test for radiosensitivity is still lacking, assessments of chromosomal fragility, cell survival and clinical medicine will continue to be useful for a small number of patients

  7. Chromosomal instability in Afrotheria: fragile sites, evolutionary breakpoints and phylogenetic inference from genome sequence assemblies

    Directory of Open Access Journals (Sweden)

    Ruiz-Herrera Aurora

    2007-10-01

    Full Text Available Abstract Background Extant placental mammals are divided into four major clades (Laurasiatheria, Supraprimates, Xenarthra and Afrotheria. Given that Afrotheria is generally thought to root the eutherian tree in phylogenetic analysis of large nuclear gene data sets, the study of the organization of the genomes of afrotherian species provides new insights into the dynamics of mammalian chromosomal evolution. Here we test if there are chromosomal bands with a high tendency to break and reorganize in Afrotheria, and by analyzing the expression of aphidicolin-induced common fragile sites in three afrotherian species, whether these are coincidental with recognized evolutionary breakpoints. Results We described 29 fragile sites in the aardvark (OAF genome, 27 in the golden mole (CAS, and 35 in the elephant-shrew (EED genome. We show that fragile sites are conserved among afrotherian species and these are correlated with evolutionary breakpoints when compared to the human (HSA genome. Inddition, by computationally scanning the newly released opossum (Monodelphis domestica and chicken sequence assemblies for use as outgroups to Placentalia, we validate the HSA 3/21/5 chromosomal synteny as a rare genomic change that defines the monophyly of this ancient African clade of mammals. On the other hand, support for HSA 1/19p, which is also thought to underpin Afrotheria, is currently ambiguous. Conclusion We provide evidence that (i the evolutionary breakpoints that characterise human syntenies detected in the basal Afrotheria correspond at the chromosomal band level with fragile sites, (ii that HSA 3p/21 was in the amniote ancestor (i.e., common to turtles, lepidosaurs, crocodilians, birds and mammals and was subsequently disrupted in the lineage leading to marsupials. Its expansion to include HSA 5 in Afrotheria is unique and (iii that its fragmentation to HSA 3p/21 + HSA 5/21 in elephant and manatee was due to a fission within HSA 21 that is probably shared

  8. CGG repeats associated with fragile X chromosome form left-handed Z-DNA structure

    Czech Academy of Sciences Publication Activity Database

    Renčiuk, Daniel; Kypr, Jaroslav; Vorlíčková, Michaela

    2011-01-01

    Roč. 95, č. 3 (2011), s. 174-181. ISSN 0006-3525 R&D Projects: GA ČR(CZ) GA202/07/0094; GA AV ČR(CZ) IAA100040701 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : fragile X chromosome syndrome * Z-DNA * trinucleotide repeats Subject RIV: BO - Biophysics Impact factor: 2.870, year: 2011

  9. Fragile DNA motifs trigger mutagenesis at distant chromosomal loci in saccharomyces cerevisiae.

    Directory of Open Access Journals (Sweden)

    Natalie Saini

    2013-06-01

    Full Text Available DNA sequences capable of adopting non-canonical secondary structures have been associated with gross-chromosomal rearrangements in humans and model organisms. Previously, we have shown that long inverted repeats that form hairpin and cruciform structures and triplex-forming GAA/TTC repeats induce the formation of double-strand breaks which trigger genome instability in yeast. In this study, we demonstrate that breakage at both inverted repeats and GAA/TTC repeats is augmented by defects in DNA replication. Increased fragility is associated with increased mutation levels in the reporter genes located as far as 8 kb from both sides of the repeats. The increase in mutations was dependent on the presence of inverted or GAA/TTC repeats and activity of the translesion polymerase Polζ. Mutagenesis induced by inverted repeats also required Sae2 which opens hairpin-capped breaks and initiates end resection. The amount of breakage at the repeats is an important determinant of mutations as a perfect palindromic sequence with inherently increased fragility was also found to elevate mutation rates even in replication-proficient strains. We hypothesize that the underlying mechanism for mutagenesis induced by fragile motifs involves the formation of long single-stranded regions in the broken chromosome, invasion of the undamaged sister chromatid for repair, and faulty DNA synthesis employing Polζ. These data demonstrate that repeat-mediated breaks pose a dual threat to eukaryotic genome integrity by inducing chromosomal aberrations as well as mutations in flanking genes.

  10. Type I bipolar disorder associated with a fragile site on chromosome 1

    Energy Technology Data Exchange (ETDEWEB)

    Turecki, G.; Mari, J.J.; M. de Smith, A.C. [Escola Paulista de Medicina, Sao Paulo (Brazil)

    1995-06-19

    The objective of this paper is to study the association between chromosomal fragile sites and type I bipolar disorder. This case-control study compares bipolar patients with normal controls. Ten cases of type I bipolar disorder diagnosed according to DSM-III-R criteria and the Composite International Diagnostic Interview (CIDI) were selected from the Escola Paulista affective disorders outpatient clinic and 10 healthy controls (CIDI negative for psychiatric diagnoses) matched for sex and age were drawn from the otorhinolaryngologic outpatient clinic of the same hospital. The cytogenetic analysis was carried out with blood lymphocytes, which were cultured in a folic acid-free medium. A total of 100 mitoses per subject were blindly analyzed to the psychiatric diagnostic assignment, and fragile sites were identified according to a minimum expected frequency of events per band in conformity with a Poisson distribution. A higher frequency of chromosomal lesions for cases than controls was found for the following bands: 1q32, 5q31, and 11q23, the 1q32 being considered a fragile site. Although no evident neuropsychiatric etiological component has been mapped to the 1q32 region so far, this finding may lead to further investigation of a possible linkage between genetic markers of this region and bipolar disorder. 40 refs., 2 tabs.

  11. Over half of breakpoints in gene pairs involved in cancer-specific recurrent translocations are mapped to human chromosomal fragile sites

    OpenAIRE

    Pierce Levi CT; Williams Laura E; Burrow Allison A; Wang Yuh-Hwa

    2009-01-01

    Abstract Background Gene rearrangements such as chromosomal translocations have been shown to contribute to cancer development. Human chromosomal fragile sites are regions of the genome especially prone to breakage, and have been implicated in various chromosome abnormalities found in cancer. However, there has been no comprehensive and quantitative examination of the location of fragile sites in relation to all chromosomal aberrations. Results Using up-to-date databases containing all cancer...

  12. Over half of breakpoints in gene pairs involved in cancer-specific recurrent translocations are mapped to human chromosomal fragile sites

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    Pierce Levi CT

    2009-01-01

    Full Text Available Abstract Background Gene rearrangements such as chromosomal translocations have been shown to contribute to cancer development. Human chromosomal fragile sites are regions of the genome especially prone to breakage, and have been implicated in various chromosome abnormalities found in cancer. However, there has been no comprehensive and quantitative examination of the location of fragile sites in relation to all chromosomal aberrations. Results Using up-to-date databases containing all cancer-specific recurrent translocations, we have examined 444 unique pairs of genes involved in these translocations to determine the correlation of translocation breakpoints and fragile sites in the gene pairs. We found that over half (52% of translocation breakpoints in at least one gene of these gene pairs are mapped to fragile sites. Among these, we examined the DNA sequences within and flanking three randomly selected pairs of translocation-prone genes, and found that they exhibit characteristic features of fragile DNA, with frequent AT-rich flexibility islands and the potential of forming highly stable secondary structures. Conclusion Our study is the first to examine gene pairs involved in all recurrent chromosomal translocations observed in tumor cells, and to correlate the location of more than half of breakpoints to positions of known fragile sites. These results provide strong evidence to support a causative role for fragile sites in the generation of cancer-specific chromosomal rearrangements.

  13. Loss of Ubr2, an E3 ubiquitin ligase, leads to chromosome fragility and impaired homologous recombinational repair

    Energy Technology Data Exchange (ETDEWEB)

    Ouyang, Yan [Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Kwon, Yong Tae [Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261 (United States); An, Jee Young [Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, PA 15261 (United States); Eller, Danny [Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Tsai, S.-C. [Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Diaz-Perez, Silvia [Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Troke, Joshua J. [Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Teitell, Michael A. [Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States); Marahrens, York [Department of Human Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 (United States)]. E-mail: ymarahrens@mednet.ucla.edu

    2006-04-11

    The N-end rule pathway of protein degradation targets proteins with destabilizing N-terminal residues. Ubr2 is one of the E3 ubiquitin ligases of the mouse N-end rule pathway. We have previously shown that Ubr2{sup -/-} male mice are infertile, owing to the arrest of spermatocytes between the leptotene/zygotene and pachytene of meiosis I, the failure of chromosome pairing, and subsequent apoptosis. Here, we report that mouse fibroblast cells derived from Ubr2{sup -/-} embryos display genome instability. The frequency of chromosomal bridges and micronuclei were much higher in Ubr2{sup -/-} fibroblasts than in +/+ controls. Metaphase chromosome spreads from Ubr2{sup -/-} cells revealed a high incidence of spontaneous chromosomal gaps, indicating chromosomal fragility. These fragile sites were generally replicated late in S phase. Ubr2{sup -/-} cells were hypersensitive to mitomycin C, a DNA cross-linking agent, but displayed normal sensitivity to gamma-irradiation. A reporter assay showed that Ubr2{sup -/-} cells are significantly impaired in the homologous recombination repair of a double strand break. In contrast, Ubr2{sup -/-} cells appeared normal in an assay for non-homologous end joining. Our results therefore unveil the role of the ubiquitin ligase Ubr2 in maintaining genome integrity and in homologous recombination repair.

  14. Mechanism of fragility at BCL2 gene minor breakpoint cluster region during t(14;18) chromosomal translocation.

    Science.gov (United States)

    Nambiar, Mridula; Raghavan, Sathees C

    2012-03-16

    The t(14;18) translocation in follicular lymphoma is one of the most common chromosomal translocations. Breaks in chromosome 18 are localized at the 3'-UTR of BCL2 gene or downstream and are mainly clustered in either the major breakpoint region or the minor breakpoint cluster region (mcr). The recombination activating gene (RAG) complex induces breaks at IgH locus of chromosome 14, whereas the mechanism of fragility at BCL2 mcr remains unclear. Here, for the first time, we show that RAGs can nick mcr; however, the mechanism is unique. Three independent nicks of equal efficiency are generated, when both Mg(2+) and Mn(2+) are present, unlike a single nick during V(D)J recombination. Further, we demonstrate that RAG binding and nicking at the mcr are independent of nonamer, whereas a CCACCTCT motif plays a critical role in its fragility, as shown by sequential mutagenesis. More importantly, we recapitulate the BCL2 mcr translocation and find that mcr can undergo synapsis with a standard recombination signal sequence within the cells, in a RAG-dependent manner. Further, mutation to the CCACCTCT motif abolishes recombination within the cells, indicating its vital role. Hence, our data suggest a novel, physiologically relevant, nonamer-independent mechanism of RAG nicking at mcr, which may be important for generation of chromosomal translocations in humans. PMID:22275374

  15. Estimating Tempo and Mode of Y Chromosome Turnover: Explaining Y Chromosome Loss With the Fragile Y Hypothesis

    OpenAIRE

    Blackmon, Heath; Demuth, Jeffery P.

    2014-01-01

    Chromosomal sex determination is phylogenetically widespread, having arisen independently in many lineages. Decades of theoretical work provide predictions about sex chromosome differentiation that are well supported by observations in both XY and ZW systems. However, the phylogenetic scope of previous work gives us a limited understanding of the pace of sex chromosome gain and loss and why Y or W chromosomes are more often lost in some lineages than others, creating XO or ZO systems. To gain...

  16. Chromosomal instability in Afrotheria: fragile sites, evolutionary breakpoints and phylogenetic inference from genome sequence assemblies

    OpenAIRE

    Ruiz-Herrera Aurora; Robinson Terence J

    2007-01-01

    Abstract Background Extant placental mammals are divided into four major clades (Laurasiatheria, Supraprimates, Xenarthra and Afrotheria). Given that Afrotheria is generally thought to root the eutherian tree in phylogenetic analysis of large nuclear gene data sets, the study of the organization of the genomes of afrotherian species provides new insights into the dynamics of mammalian chromosomal evolution. Here we test if there are chromosomal bands with a high tendency to break and reorgani...

  17. Fluorescent in-situ hybridization of cattle and sheep chromosomes with cloned human fragile-X DNA

    DEFF Research Database (Denmark)

    Ali, Ahmd; Thomsen, Preben Dybdahl; Babar, M.E.

    2009-01-01

    An extensive study on spontaneous and 5-Fluorodeoxyuridine induced fragile sites identified Xq31 in cattle (Bos taurus) and (Xq24, Xq26) in sheep (Ovis aries) in addition to several autosomal fragile sites (under publication). A ZOO-FISH study using three cloned human fragile-X probes with CCG...

  18. Identificación de fragilidad cromosómica mediante 5’azacitidina en linfocitos de bovinos Identification of chromosome fragility using 5’azacytidine in cattle lymphocytes

    Directory of Open Access Journals (Sweden)

    S Llambí

    2007-01-01

    Full Text Available Los sitios frágiles comunes se definen como regiones del cromosoma eucariota con tendencia a sufrir fracturas o quiebres frente a sustancias inductoras adicionadas al medio de cultivo linfocitario como la 5’azacitidina. Actualmente en humanos y animales domésticos las regiones de fragilidad cromosómica han sido correlacionadas con heredopatologías diversas (síndrome de retardo mental, paraqueratosis hereditaria, síndrome de calvicie en terneros, alteraciones de la fertilidad. En bovinos de la raza Holando-Uruguaya ha sido descrita la presencia de un sitio frágil en el cromosoma sexual X (FRA Xq 3.1 con manifestación espontánea en cultivos linfocitarios. En la presente comunicación se analiza la respuesta de fragilidad cromosómica en cultivos linfocitarios de una hembra bovina (raza Holando-Uruguaya, sometidos a la inducción de 5’azacitidina. Se contabilizan regiones de fragilidad a nivel autosómico y en el cromosoma sexual X.Common fragile sites are regions of the eukaryotic chromosome with a tendency to show breaks or gaps when inductors such as 5’azacytidine are added to the lymphocyte culture media. Recently, chromosome fragile sites have been correlated with hereditary defects affecting humans and domestic animals (mental retardation syndrome, parakeratosis, baldy calf syndrome and low fertility. A spontaneous fragile site in the sexual chromosome X (FRA Xq 3.1 was observed in lymphocyte cultures of Uruguayan Holstein-Friesian cattle. In the present study, the chromosome fragility expression in lymphocyte cultures of Uruguayan Holstein-Friesian female cattle treated with 5’azacytidine was analized. A number of different fragility regions were scored considering autosomes and sexual X chromosomes.

  19. Fragile States

    DEFF Research Database (Denmark)

    Brock, Lothar; Holm, Hans-Henrik; Sørensen, Georg;

    What does state fragility means and how is it adressed. Case studies of where it went wrong and where it did not......What does state fragility means and how is it adressed. Case studies of where it went wrong and where it did not...

  20. Examination of Replication Dynamics in Fragile Sites Through Molecular Combing

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    Chumki, Shahana Ahmed

    2015-08-01

    Full Text Available Chromosomal fragile sites are specific loci that exhibit instability visible as gaps and breaks on the chromosome following inhibition of DNA synthesis and are generally categorized into two main classes: rare fragile sites (RFSs and common fragile sites (CFSs. Under standard conditions, CFSs are typically stable but are prone to breakage in cells subjected to replication stress. In recent years, their role in the generation of gross chromosome rearrangements has become increasingly evident, and fragile sites have now connected to chromosome instability in cancer cells. The connection between CFSs and cancer thus highlights the importance of the regulation of DNA replication to prevent cancer development. The study of fragile sites in the yeast model organism has provided insight into the mechanisms that lead to breakage and genome instability. Through the process of molecular combing, replication dynamics can be observed at fragile sites to further understand the consequence of replication stress on DNA damage.

  1. MUS81 promotes common fragile site expression

    DEFF Research Database (Denmark)

    Ying, Songmin; Minocherhomji, Sheroy; Chan, Kok Lung;

    2013-01-01

    Fragile sites are chromosomal loci with a propensity to form gaps or breaks during early mitosis, and their instability is implicated as being causative in certain neurological disorders and cancers. Recent work has demonstrated that the so-called common fragile sites (CFSs) often impair the...... faithful disjunction of sister chromatids in mitosis. However, the mechanisms by which CFSs express their fragility, and the cellular factors required to suppress CFS instability, remain largely undefined. Here, we report that the DNA structure-specific nuclease MUS81-EME1 localizes to CFS loci in early...

  2. Fragility in the 14q21q translocation region

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    Stacy R. Denison

    2002-01-01

    Full Text Available Aphidicolin (APC-induced chromosomal breakage was analyzed for women representing three generations of a single family and carrying a Robertsonian translocation rob(14q21q. Fluorescence in situ hybridization (FISH analysis confirmed the dicentric constitution of the derived chromosome and indicated the absence of beta-satellite signal at the translocation region. Per-individual analysis of metaphases from APC-treated peripheral blood lymphocyte cultures identified significantly nonrandom chromosomal breakage at the translocation region in all three individuals examined. The APC-inducible fragility at the 14q21q translocation region suggests that this rearrangement was the result of chromosomal mutation at fragile site(s in the progenitor chromosomes, or that this fragility was the result of the fusion of nonfragile progenitor chromosomes.

  3. The Fragile Definition of State Fragility

    OpenAIRE

    Graziella Bertocchi; Andrea Guerzoni

    2010-01-01

    We investigates the link between fragility and economic development in sub-Saharan Africa over a yearly panel including 28 countries for the 1999-2004 period. Beside the conventional definition of fragility adopted by the OECD Development Assistance Committee, we introduce the more severe definition of extreme fragility. We show that only the latter exerts a significantly negative impact on economic development, once standard economic, demographic, and institutional regressors are accounted f...

  4. Biomedical Advances in Developmental Psychology: The Case of Fragile X Syndrome.

    Science.gov (United States)

    Hagerman, Randi J.

    1996-01-01

    Discusses the Human Genome Project and the identification of Fragile X Syndrome, the most common inherited cause of mental retardation. Fragile X Syndrome is caused by an abnormal gene on the bottom of the X chromosome. Examined the phenotype of Fragile X Syndrome in males and females and the spectrum of learning difficulties caused by the…

  5. National Fragile X Foundation

    Science.gov (United States)

    ... Anthology Advocacy National Fragile X Foundation Advocacy Day STAR: Local Advocacy Agenda and Accomplishments Community Events International ... Making Sense of the Alphabet Soup Teaching Your Child to Ask for Something Behavior and Fragile X ...

  6. Targeting fragile X

    OpenAIRE

    Gantois, Ilse; Kooy, R. Frank

    2002-01-01

    Ten years after the identification of the gene responsible for fragile X syndrome, recent studies have revealed a list of mRNAs bound by the fragile X gene product and have identified specific sequences required for the interaction between the fragile X protein and its targets. These results are a breakthrough in understanding why absence of the fragile X protein leads to mental retardation.

  7. Fragile X Syndrome Overview

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Fragile X Syndrome: Overview Skip sharing on social media links Share ... menu on the left. ​ Common Name Fragile X syndrome or Fragile X Medical or Scientific Names Martin-Bell syndrome Last ...

  8. Human Lymphoid Translocation Fragile Zones Are Hypomethylated and Have Accessible Chromatin

    OpenAIRE

    Lu, Zhengfei; Lieber, Michael R.; Tsai, Albert G.; Pardo, Carolina E.; Müschen, Markus; Kladde, Michael P.; Hsieh, Chih-Lin

    2015-01-01

    Chromosomal translocations are a hallmark of hematopoietic malignancies. CG motifs within translocation fragile zones (typically 20 to 600 bp in size) are prone to chromosomal translocation in lymphomas. Here we demonstrate that the CG motifs in human translocation fragile zones are hypomethylated relative to the adjacent DNA. Using a methyltransferase footprinting assay on isolated nuclei (in vitro), we find that the chromatin at these fragile zones is accessible. We also examined in vivo ac...

  9. Infantile Autism Associated with the Fragile-X Syndrome.

    Science.gov (United States)

    Meryash, David L.; And Others

    1982-01-01

    A six-year-old mentally retarded child is presented with a clinical picture consistent with the diagnosis of childhood autism. Chromosomal studies revealed a male karyotype with approximately 11 percent of the cells counted containing a fragile site on the X chromosome. (Author)

  10. Insular Volume Reduction in Fragile X Syndrome

    OpenAIRE

    Cohen, Jeremy D.; Nichols, Taylor; Brignone, Laura; Hall, Scott S.; Reiss, Allan L.

    2011-01-01

    Fragile X Syndrome (FraX) is the most common form of inherited mental deficit and is caused by mutations of the Fragile X Mental Retardation 1 (FMR1) gene on the X chromosome. While males and females with the full FMR1 mutation are affected differently because the disorder is X-linked, both suffer from varying degrees of cognitive impairment, attention deficits and social anxiety. The insula is a sensory integrative region that has been increasingly suggested as a critical area involved in an...

  11. FRAGILE X-SYNDROME AND MENTAL RETARDATION

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    Ana MOMIROVSKA

    2000-06-01

    Full Text Available Fragile X-Syndrome is the most common inherited form of mental retardation. The disease is caused by defect of the fragile X mental retardation gene (FMR 1, located on X chromosome, due to expansion of the repetitive CGG sequence in the promoter region. The modern approach for diagnosis of the disease is based on the use of direct DNA analysis of the FMR 1 gene. Recombinant DNA technology techniques overcome the deficiencies of the cyto-genetic test, such as large number of false positive results.In the molecular diagnostics of Fragile X-Syndrome, two basic DNA methods are used: a Southern blot analysis of Eco RI or Eco R I/Eag I digested DNA samples and b PCR for amplification of CG rich regions. Southern blot is used for detection of full mutations and premutations, and PCR for normal and premutation alleles sizing.

  12. Two progenitor cells for human oogonia inferred from pedigree data and the X-inactivation imprinting model of the fragile-X syndrome.

    OpenAIRE

    Laird, C D; Lamb, M M; Thorne, J L

    1990-01-01

    Laird has proposed that the human fragile-X syndrome is caused by abnormal chromosome imprinting. The analysis presented here supports and extends this proposal. Using published pedigrees that include DNA polymorphism (RFLP) data, we establish that the states of the fragile-X mutation termed "imprinted" and "nonimprinted" usually can be distinguished by the level of cytogenetic expression of the fragile-X chromosome. This information is then used to assess the state of the fragile-X allele in...

  13. Features of Fragile X Syndrome

    Science.gov (United States)

    ... Figuring Out CGG Repeats! Donate | Print Fragile X Syndrome Fragile X syndrome (FXS) is a genetic condition that causes ... health concerns associated with the condition. Features of Fragile X Syndrome in Males Read our Story The majority of ...

  14. Fragile X Syndrome: Other FAQs

    Science.gov (United States)

    ... NICHD Research Information Clinical Trials Resources and Publications Fragile X Syndrome: Other FAQs Skip sharing on social media links ... Are there specific disorders or conditions associated with Fragile X syndrome? Among the other conditions associated with Fragile X ...

  15. A Case Report of Fragile X Syndrome with Fingers Anomaly

    OpenAIRE

    F. Ashrafzadeh; Abbaszadegan, M; Ghaemi, N

    2003-01-01

    Fragile X Syndrome, the most common cause of inherited mental retardation, results from mutation in fragile X mental retardation gene (FMR1) on long arm of X chromosome, Xq27.3. Clinical features include moderate to severe mental retardation without neurologic deficit, long face, large ears, prominent jaw, macro-orchidism, attention deficit, behavior disorder and occasionally autistic behavior . Hyperextensible joints may also be seen in these patients. There is no other c...

  16. Fragile X syndrome.

    OpenAIRE

    Wiebe, E.; A. Wiebe

    1994-01-01

    Fragile X syndrome is the most common form of inherited mental retardation. Only recently has it been possible to detect all carriers and transmitters. We review the syndrome and discuss the pedigree of a large fragile X family. Family doctors should identify cases in their practices so genetic counseling can be offered to the families.

  17. Equipment fragility testing

    International Nuclear Information System (INIS)

    Current probabilistic risk assessment (PRA) methods for nuclear power plants utilize component fragilities which are for the most part based on a limited data base and engineering judgement. The seismic design of components is based on code limits and NRC requirements that do not reflect the actual capacity of a component to resist failure. In order to improve the present component fragility data base and establish component seismic design margins, the NRC has commissioned a projected three-year program to compile existing fragilities data and at the same time independently perform fragilities tests on selected mechanical and electrical components. This paper presents the planning and technical approach being taken by LLNL in the NRC Component Fragility Program

  18. Mapping and ordered cloning of the human X chromosome

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, C.T.; Nelson, D.L.

    1992-12-01

    Progress is reported on gathering X chromosome specific libraries and integrating those with the library produced in this project. Further studies on understanding Fragile X Syndrome and other hereditary diseases related to the X chromosome are described. (DT)

  19. Modest alterations in patterns of motor neuron dendrite morphology in the Fmr1 knockout mouse model for Fragile X

    OpenAIRE

    Thomas, Christina C.; Combe, Crescent L.; Dyar, Kenneth A.; Inglis, Fiona M.

    2008-01-01

    Fragile X, an inheritable form of mental retardation, is caused by the inactivation of a gene on the X chromosome, FMR1 which codes for an RNA binding protein, Fragile X Mental Retardation Protein. Loss of this protein is associated with reduced complexities of neuronal dendrites and alterations in spine morphology in a number of cortical brain regions, and these deficits may underlie the cognitive impairment observed in fragile X patients. Among the many symptoms of fragile X are altered mot...

  20. Trio Fragile / Olga Kaljundi

    Index Scriptorium Estoniae

    Kaljundi, Olga, 1941-2001

    1998-01-01

    Tallinna Vene Draamateatri galeriis esinenud trupi "Trio Fragile" vernissaazhist. Trio loomingust ja osalejatest : kahe muusiku seltskonnas esineb ka 1984.a. Kunstiülikooli lõpetanud kunstnik Tõnu Talve.

  1. FMR1 fully expanded mutation with minimal methylation in a high functioning fragile X male.

    OpenAIRE

    Wang, Z.; Taylor, A K; Bridge, J.A.

    1996-01-01

    Cytogenetic and molecular genetic analysis of a peripheral blood sample from a 31 year old, non-mentally retarded male with a family history of fragile X syndrome showed unexpected results. Nine percent of cells evaluated cytogenetically expressed a fragile X chromosome and molecular examination of the FMR1 gene showed a highly unusual pattern defined as a minimally methylated fully expanded mutation. This case illustrates the need to recognise exceptional variations of fragile X syndrome mut...

  2. Fragile States : Securing Development

    OpenAIRE

    Zoellick, R.

    2008-01-01

    Fragile states are the toughest development challenge of our era. But we ignore them at our peril: about one billion people live in fragile states, including a disproportionate number of the world's extreme poor, and they account for most of today's wars. These situations require a different framework of building security, legitimacy, governance, and the economy. Only by securing development - bringing security and development together to smooth the transition from conflict to peace and then ...

  3. Expression and identification of folate-sensitive fragile sites in British Suffolk sheep (Ovis aries)

    Indian Academy of Sciences (India)

    Ahmad Ali; Muhammad Abdullah; Masroor Ellahi Babar; Khalid Javed; Asif Nadeem

    2008-12-01

    An investigation to understand the dynamics and biological significance of fragile site expression, and identification of 5-fluorodeoxyuridine (FUdR) induced chromosomal gaps/breaks, were carried out in an experimental flock of 45 Suffolk sheep. The statistical comparison revealed, highly significant variation in the frequency of chromosomal fragile site expression between control and FUdR cultures. Mean (± S.D.) values for cells with gaps and breaks, or aberrant cell count (AC), and the number of aberrations (NoA) per animal were 2.02 ± 0.34, 2.42 ± 0.48, 13.26 ± 0.85 and 21.87 ± 1.88 ($P \\lt 0.01$) in control and FUdR cultures, respectively. The comparison of age revealed nonsignificant variation between control and FUdR cultures. The G-band analysis of fragile site data revealed gaps in 29 autosomal and two X-chromosomal bands in the control cultures, whereas FUdR treated cultures scored 78 unstable bands in autosomes of which 56 were significantly fragile. X-chromosomes expressed breaks and gaps in six G-negative bands and five of them (Xq13, Xq15, Xq17, Xq24 and Xq26) were significantly fragile. The distribution comparison of autosomal fragile sites between sex groups did not reveal any significant variation. Female X-chromosomes were significantly more fragile than the male X-chromosomes. The distribution comparison for age groups (lambs versus adults) revealed significantly higher number of fragile bands in adults. Comparison of published data on reciprocal translocations in sheep with the fragile-site data obtained in this study indicated that the break sites of both phenomena were correlated. Similarities were also found between fragile sites and breakpoints of evolutionary significance in family Bovidae.

  4. Ocular Motor Indicators of Executive Dysfunction in Fragile X and Turner Syndromes

    Science.gov (United States)

    Lasker, Adrian G.; Mazzocco, Michele M. M.; Zee, David S.

    2007-01-01

    Fragile X and Turner syndromes are two X-chromosome-related disorders associated with executive function and visual spatial deficits. In the present study, we used ocular motor paradigms to examine evidence that disruption to different neurological pathways underlies these deficits. We tested 17 females with fragile X, 19 females with Turner…

  5. Fragile X syndrome in two siblings with major congenital malformations

    Energy Technology Data Exchange (ETDEWEB)

    Giampietro, P.F.; Haas, B.R.; Lipper, E. [Cornell Univ. Medical Center, New York, NY (United States)] [and others

    1996-05-17

    We report on 2 brothers with both fragile X and VACTERL-H syndrome. The first sibling, age 5, had bilateral cleft lip and palate, ventricular septal defect, and a hypoplastic thumb. The second sibling, age 2{1/2}, had a trachesophageal fistula, esophageal atresia, and vertebral abnormality. High-resolution chromosome analysis showed a 46,XY chromosome constitution in both siblings. By PCR and Southern blot analysis, the siblings were found to have large triplet repeat expansions in the fragile X gene (FMR 1) and both had methylation mosaicism. Enzyme kinetic studies of iduronate sulfatase demonstrated a two-fold increase in activity in the first sib as compared to the second. Possible mechanisms through which the fragile X mutation can cause down-regulation of adjacent loci are discussed. 24 refs., 4 figs.

  6. Fragility and MDG Progress: How useful is the Fragility Concept?

    OpenAIRE

    Harttgen, Kenneth; Klasen, Stephan

    2010-01-01

    While progress in developing countries as a whole, in terms of growth, poverty reduction, and several MDGs, has been quite good in recent years, fragile states lag behind in levels of MDG achievement. To understand the link between fragility and MDG progress, and also to identify the most effective policy interventions to achieve the MDGs, it is essential that fragile states are appropriately defined and classified. While the amount of literature on how to engage with fragile stat...

  7. State fragility: Concept and measurement

    OpenAIRE

    Baliamoune-Lutz, Mina; McGillivray, Mark

    2008-01-01

    The international donor community has grave concerns about the prospects for poverty reduction in what it terms fragile states. A state is classified as fragile if its country policy and institutional assessment (CPIA) score falls below a particular threshold. Recognizing that all states are fragile to varying degrees, this paper questions the method used by the international community to deem a country fragile. This paper develops a framework that uses fuzzy-set theory to deem a country as f...

  8. Component fragility research program

    International Nuclear Information System (INIS)

    To demonstrate how ''high-level'' qualification test data can be used to estimate the ultimate seismic capacity of nuclear power plant equipment, we assessed in detail various electrical components tested by the Pacific Gas ampersand Electric Company for its Diablo Canyon plant. As part of our Phase I Component Fragility Research Program, we evaluated seismic fragility for five Diablo Canyon components: medium-voltage (4kV) switchgear; safeguard relay board; emergency light battery pack; potential transformer; and station battery and racks. This report discusses our Phase II fragility evaluation of a single Westinghouse Type W motor control center column, a fan cooler motor controller, and three local starters at the Diablo Canyon nuclear power plant. These components were seismically qualified by means of biaxial random motion tests on a shaker table, and the test response spectra formed the basis for the estimate of the seismic capacity of the components. The seismic capacity of each component is referenced to the zero period acceleration (ZPA) and, in our Phase II study only, to the average spectral acceleration (ASA) of the motion at its base. For the motor control center, the seismic capacity was compared to the capacity of a Westinghouse Five-Star MCC subjected to actual fragility tests by LLNL during the Phase I Component Fragility Research Program, and to generic capacities developed by the Brookhaven National Laboratory for motor control center. Except for the medium-voltage switchgear, all of the components considered in both our Phase I and Phase II evaluations were qualified in their standard commercial configurations or with only relatively minor modifications such as top bracing of cabinets. 8 refs., 67 figs., 7 tabs

  9. BONE FRAGILITY IN TURNER SYNDROME: MECHANISMS AND PREVENTION STRATEGIES

    Directory of Open Access Journals (Sweden)

    Maria Felicia Faienza

    2016-04-01

    Full Text Available Bone fragility is recognized as one of major comorbidities in Turner Syndrome (TS. The mechanisms underlying bone impairment in affected patients are not clearly elucidated, but estrogen deficiency and X-chromosomal abnormalities represent important factors. Moreover, although many girls with TS undergo recombinant growth hormone (rGH therapy to treat short stature, the efficacy of this treatment on BMD is controversial. The present review will focus on bone fragility in subjects with TS, providing an overview on the pathogenic mechanisms and some prevention strategies.

  10. Bone Fragility in Turner Syndrome: Mechanisms and Prevention Strategies.

    Science.gov (United States)

    Faienza, Maria Felicia; Ventura, Annamaria; Colucci, Silvia; Cavallo, Luciano; Grano, Maria; Brunetti, Giacomina

    2016-01-01

    Bone fragility is recognized as one of the major comorbidities in Turner syndrome (TS). The mechanisms underlying bone impairment in affected patients are not clearly elucidated, but estrogen deficiency and X-chromosomal abnormalities represent important factors. Moreover, although many girls with TS undergo recombinant growth hormone therapy to treat short stature, the efficacy of this treatment on bone mineral density is controversial. The present review will focus on bone fragility in subjects with TS, providing an overview on the pathogenic mechanisms and some prevention strategies. PMID:27199891

  11. Bone Fragility in Turner Syndrome: Mechanisms and Prevention Strategies

    Science.gov (United States)

    Faienza, Maria Felicia; Ventura, Annamaria; Colucci, Silvia; Cavallo, Luciano; Grano, Maria; Brunetti, Giacomina

    2016-01-01

    Bone fragility is recognized as one of the major comorbidities in Turner syndrome (TS). The mechanisms underlying bone impairment in affected patients are not clearly elucidated, but estrogen deficiency and X-chromosomal abnormalities represent important factors. Moreover, although many girls with TS undergo recombinant growth hormone therapy to treat short stature, the efficacy of this treatment on bone mineral density is controversial. The present review will focus on bone fragility in subjects with TS, providing an overview on the pathogenic mechanisms and some prevention strategies. PMID:27199891

  12. Mapping and ordered cloning of the human X chromosome. Progress report, September 1991--November 1992

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, C.T.; Nelson, D.L.

    1992-12-01

    Progress is reported on gathering X chromosome specific libraries and integrating those with the library produced in this project. Further studies on understanding Fragile X Syndrome and other hereditary diseases related to the X chromosome are described. (DT)

  13. Fragile X Syndrome

    Directory of Open Access Journals (Sweden)

    Wilmar Saldarriaga

    2015-01-01

    Full Text Available Fragile X Syndrome (FXS is a genetic disease due to a CGG trinucleotide expansion, named full mutation (greater than 200 CGG repeats, in the fragile X mental retardation 1 gene locus Xq27.3; which leads to an hypermethylated region in the gene promoter therefore silencing it and lowering the expression levels of the fragile X mental retardation 1, a protein involved in synaptic plasticity and maturation.  Individuals with FXS present with intellectual disability, autism, hyperactivity, long face, large or prominent ears and macroorchidism at puberty and thereafter. Most of the young children with FXS will present with language delay, sensory hyper arousal and anxiety. Girls are less affected than boys, only 25% have intellectual disability. Given the genomic features of the syndrome, there are patients with a number of triplet repeats between 55 and 200, known as premutation carriers. Most carriers have a normal IQ but some have developmental problems. The diagnosis of FXS has evolved from karyotype with special culture medium, to molecular techniques that are more sensitive and specific including PCR and Southern Blot. During the last decade, the advances in the knowledge of FXS, has led to the development of investigations on pharmaceutical management or targeted treatments for FXS. Minocycline and sertraline have shown efficacy in children.

  14. Cytogenetic and Molecular Investigation in Children with Possible Fragile X Syndrome

    Directory of Open Access Journals (Sweden)

    Onur Ozer

    2012-04-01

    Full Text Available Objective: Fragile X syndrome (FXS is the most common cause of inherited mental retardation and is due to a mutation in the X-linked FMR1 gene. Molecular genetic testing and chromosome analysis are indicated for this disorder. In this context, we tried to determine the frequency of the FXS, and other chro¬mosomal abnormalities of Turkish pediatric neurology outpatients. Materials and Methods: Cytogenetic and molecular screenings were performed to esti-mate the prevalence of the fragile X in 107 patients with mental retardation, language disorders, hyperactivity, develop¬mental delay or fragile X syndrome phenotype. Only 26 out of 107 patients were screened, molecularly. Results: Cytogenetically fragile X-positive cells was found in 8 cases (7.5% of 107 patients; in 4.7% of males and in 2.8% of females. The autosomal fragile sites (FS was found in 14 (13.1% cases. One (0.9% patient had pericentric inversion of chromosome 9. Molecular analysis were performed for 26 patients and all patients showed normal CGG expansion. Conclusion: In diagnosis of fragile X syndrome, chromosome analysis must be run in conjunction with the molecular studies. It is recommended that all members of the fragile X family under risk should be screened both by cytogenetic and molecular methods. Genetic counseling can be useful to patients and families considering genetic testing. [Cukurova Med J 2012; 37(2.000: 76-83

  15. FRAGILITY AND MDG PROGRESS: HOW USEFUL IS THE FRAGILITY CONCEPT?

    OpenAIRE

    Kenneth Harttgen and Stephan Klasen

    2010-01-01

    While progress in developing countries as a whole, in terms of growth, poverty reduc-tion, and several MDGs, has been quite good in recent years, fragile states lag behind in levels of MDG achievement. To understand the link between fragility and MDG progress, and also to identify the most effective policy interventions to achieve the MDGs, it is es-sential that fragile states are appropriately defined and classified. While the amount of literature on how to engage with fragile states is rapi...

  16. Avoiding the Fragility Trap in Africa

    OpenAIRE

    Andrimihaja, Noro Aina; Cinyabuguma, Matthias; Devarajan, Shantayanan

    2011-01-01

    Not only do Africa's fragile states grow more slowly than non-fragile states, but they seem to be caught in a "fragility trap". For instance, the probability that a fragile state in 2001 was still fragile in 2009 was 0.95. This paper presents an economic model where three features -- political instability and violence, insecure property rights and unenforceable contracts, and corruption --...

  17. Advances in research on the fragile X syndrome.

    Science.gov (United States)

    Mazzocco, M M

    2000-01-01

    Fragile X syndrome is a neurodevelopmental disorder that results from a single gene mutation on the X chromosome. The purpose of this review is to summarize key advances made in understanding the fragile X premutation gene seen in carriers and the full mutation gene seen in persons with the syndrome. DNA testing has replaced cytogenetic testing as the primary method for identification of fragile X, although the efficacy of protein level screening is being explored. The premutation is associated with no effects, although there is evidence of physical effects-primarily premature menopause and mild outward features of the fragile X syndrome-among premutation carriers. There is much controversy regarding premutation effects on psychological development. The few experimental studies carried out to date do not suggest noticeable or significant effects. One challenge in addressing this controversy is the sometimes ambiguous differentiation between premutation and full mutation genes. There is a well-established yet highly variable phenotype of the full mutation. Research from this decade has helped to address specific aspects of this phenotype, including the early course of its development in males, the influence of home and family environments, the nature of social difficulties and autistic features seen in boys and girls with fragile X, and the potential role of hyperarousal or hyper-reactivity. Studies in these areas, and on the role of FMR protein, will contribute towards ongoing advances in our understanding of fragile X syndrome and its mechanisms. The variability in physical, social, and cognitive features, as described in this review, is one that prohibits clear-cut screening guidelines designed to avoid high rates of both false positives and false negatives. Results from recent studies indicate the need to consider behavioral features in selecting candidates for fragile X screening. MRDD Research Reviews 2000;6:96-106. PMID:10899802

  18. Fragile X founder effect and distribution of CGG repeats among the mentally retarded population of Andalusia, South Spain

    Directory of Open Access Journals (Sweden)

    Yolanda de Diego

    2002-01-01

    Full Text Available Fragile X syndrome is the most common inherited form of mental retardation. We investigated the prevalence of the Fragile X syndrome in the population with mental retardation of unknown etiology in Andalusia, South Spain. We analyzed 322 unrelated patients (280 males and 42 females, and found a fragile X syndrome frequency of 6.5%. Among the non-fragile X chromosomes, the 29 CGG repeat was the most common allele. At the linked microsatellite DXS548 locus, we found a new allele which we called "allele 10" (17 CA. Similar to other south European populations, allele 2 (25 CA at the DXS548 locus and the fragile X allele were in linkage disequilibrium supporting the idea of a common founder chromosome predisposing to the CGG expansion.

  19. Fragile X expression is decreased by 5-azacytidine and S-adenosylhomocysteine.

    OpenAIRE

    Mixon, J C; Dev, V. G.

    1983-01-01

    A lymphoblastoid cell line derived from a patient with fragile X chromosome exhibited fragility only when 5-fluoro-2'-deoxyuridine (FUdR) was added to the culture medium. Addition of methionine with FUdR greatly increased the frequency of fragile X. Addition of 5-azacytidine (an inhibitor of methylation at the level of DNA) or S-adenosylhomocysteine (an inhibitor of the synthesis of the methyl group donor S-adenosylmethionine) reversed the effect of methionine as well as that of FUdR. It is p...

  20. Fragile States and Development Policy

    OpenAIRE

    Besley, Timothy J.; Persson, Torsten

    2011-01-01

    It is widely recognized that fragile states are key symptoms of under-development in many parts of the world. Such states are incapable of delivering basic services to their citizens and political violence is commonplace. As of yet, mainstream development economics has not dealt in any systematic way with such concerns and the implications for development assistance. This paper puts forward a frame-work for analyzing fragile states and applies it to a variety of development policies in differ...

  1. Aid allocation and fragile states

    OpenAIRE

    McGillivray, Mark

    2006-01-01

    This paper summarises research on aid allocation and effectiveness, highlighting the current findings of recent research on aid allocation to fragile states. Fragile states are defined by the donor community as those with either critically poor policies or poorly performing institutions, or both. The paper examines the research findings in the broader context of research and analysis on how aid should and is being allocated across all developing countries. Various aid allocation models and th...

  2. Large transcription units unify copy number variants and common fragile sites arising under replication stress

    OpenAIRE

    Wilson, Thomas E.; Arlt, Martin F.; Park, So Hae; Rajendran, Sountharia; Paulsen, Michelle; Ljungman, Mats; Glover, Thomas W.

    2015-01-01

    Copy number variants (CNVs) resulting from genomic deletions and duplications and common fragile sites (CFSs) seen as breaks on metaphase chromosomes are distinct forms of structural chromosome instability precipitated by replication inhibition. Although they share a common induction mechanism, it is not known how CNVs and CFSs are related or why some genomic loci are much more prone to their occurrence. Here we compare large sets of de novo CNVs and CFSs in several experimental cell systems ...

  3. Resilience and the Fragile City

    Directory of Open Access Journals (Sweden)

    John de Boer

    2015-04-01

    Full Text Available Humanitarian, security, and development actors are witnessing two distinct but intertwined trends that will have a dramatic impact on their operations. The first relates to the fact that the locus of global poverty and vulnerability to disaster are increasingly concentrated in fragile and conflict affected states. The second trend is associated with the notion that the world has entered a period of unprecedented urbanization. For the first time in history, more people live inside urban centres than outside of them. As the world continues to urbanize, global emergencies will increasingly be concentrated in cities, particularly in lower income and fragile countries where the pace of urbanization is fastest. Yet, despite the growing risks facing urban populations living in fragile and conflict affected countries, there is very little understanding of what can be done to reduce the risks posed to these cities and their populations.

  4. Learning to deliver education in fragile states

    Directory of Open Access Journals (Sweden)

    Martin Greeley

    2006-07-01

    Full Text Available The Fragile States Group within the Development AssistanceCommittee (DAC of the Organisation for EconomicCooperation and Development is working to advise donors onprovision of education (and other services in ‘fragile states’.

  5. Learning to deliver education in fragile states

    OpenAIRE

    Martin Greeley; Pauline Rose

    2006-01-01

    The Fragile States Group within the Development AssistanceCommittee (DAC) of the Organisation for EconomicCooperation and Development is working to advise donors onprovision of education (and other) services in ‘fragile states’.

  6. Genetics Home Reference: fragile X syndrome

    Science.gov (United States)

    ... College of Medical Genetics Practice Guideline Boston Children's Hospital Centre for Genetics Education (Australia) Disease InfoSearch: Fragile X Syndrome Emory University School of Medicine: Fragile X Premutation--a Cause ...

  7. International Companies in Fragile States

    DEFF Research Database (Denmark)

    Patey, Luke; Kragelund, Peter

    Denmark must not fail to promote corporate social responsibility in fragile states. International companies remain active in these environments, and often worsen rather than alleviate poor governance. Financial transparency and human rights initiatives offer the first step in ensuring that this...

  8. Chromosomal abnormalities in a psychiatric population

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, K.E.; Lubetsky, M.J.; Wenger, S.L.; Steele, M.W. [Univ. of Pittsburgh Medical Center, PA (United States)

    1995-02-27

    Over a 3.5 year period of time, 345 patients hospitalized for psychiatric problems were evaluated cytogenetically. The patient population included 76% males and 94% children with a mean age of 12 years. The criteria for testing was an undiagnosed etiology for mental retardation and/or autism. Cytogenetic studies identified 11, or 3%, with abnormal karyotypes, including 4 fragile X positive individuals (2 males, 2 females), and 8 with chromosomal aneuploidy, rearrangements, or deletions. While individuals with chromosomal abnormalities do not demonstrate specific behavioral, psychiatric, or developmental problems relative to other psychiatric patients, our results demonstrate the need for an increased awareness to order chromosomal analysis and fragile X testing in those individuals who have combinations of behavioral/psychiatric, learning, communication, or cognitive disturbance. 5 refs., 1 fig., 2 tabs.

  9. Altered structural brain connectome in young adult fragile X premutation carriers

    OpenAIRE

    Leow, Alex; Harvey, Danielle; Goodrich-Hunsaker, Naomi J.; GadElkarim, Johnson; Kumar, Anand; Zhan, Liang; Rivera, Susan M.; Simon, Tony J

    2014-01-01

    Fragile X premutation carriers (fXPC) are characterized by 55–200 CGG trinucleotide repeats in the 5′ untranslated region on the Xq27.3 site of the X chromosome. Clinically, they are associated with the Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS), a late-onset neurodegenerative disorder with diffuse white matter neuropathology. Here, we conducted first-ever graph theoretical network analyses in fXPCs using thirty-direction diffusion-weighted MRI acquired from 42 heal...

  10. Preserved entropy and fragile magnetism

    Science.gov (United States)

    Canfield, Paul C.; Bud’ko, Sergey L.

    2016-08-01

    A large swath of quantum critical and strongly correlated electron systems can be associated with the phenomena of preserved entropy and fragile magnetism. In this overview we present our thoughts and plans for the discovery and development of lanthanide and transition metal based, strongly correlated systems that are revealed by suppressed, fragile magnetism, quantum criticality, or grow out of preserved entropy. We will present and discuss current examples such as YbBiPt, YbAgGe, YbFe2Zn20, PrAg2In, BaFe2As2, CaFe2As2, LaCrSb3 and LaCrGe3 as part of our motivation and to provide illustrative examples.

  11. Ectodermal Dysplasia Skin Fragility Syndrome

    Directory of Open Access Journals (Sweden)

    Ayça Alan Atalay

    2014-06-01

    Full Text Available Ectodermal dysplasia-skin fragility syndrome (EDSFS is a rare autosomal recessive genodermatosis first described in 1997 by Mc Grath. EDSFS results from loss of function mutations in plakophilin-1 (PKP1. PKP1 is a structural component of desmosomes, cellcell adhesion complexes. It is also found as a nuclear protein in several cell types that are lack of desmosomes. In skin, however, PKP1 expression is confined mainly to suprabasal keratinocytes and the outer root sheath of hair follicules. Loss of function mutation in PKP1 leads to extensive skin fragility, bullae and erosions following minor trauma, focal keratoderma with painful fissures, alopecia, and nail dystrophy. In some patients hypohidrosis may also be seen. EDSFS is now considered as a specific suprabasal form of epidermolysis bullosa simplex. In this report we describe a 20 year old EDSFS case.

  12. Financial Liberalization and Financial Fragility

    OpenAIRE

    Demirguc-Kent, Asli; Detragiache, Enrica

    1998-01-01

    The authors study the empirical relationship between banking crises and financial liberalization using a panel of data for 53 countries for 1980-95. They find that banking crises are more likely to occur in liberalized financial systems. But financial liberalization's impact on a fragile banking sector is weaker where the institutional environment is strong--especially where there is respect for the rule of law, a low level of corruption, and good contract enforcement. They examine evidence o...

  13. Parental Relationships in Fragile Families

    OpenAIRE

    McLanahan, Sara; Beck, Audrey N.

    2010-01-01

    As nonmarital childbearing escalated in the United States over the past half century, fragile families—defined as unmarried couples with children—drew increased interest from researchers and policy makers. Sara McLanahan and Audrey Beck discuss four aspects of parental relationships in these families: the quality of parents’ intimate relationship, the stability of that relationship, the quality of the co-parenting relationship among parents who live apart, and nonresident fathers’ involvement...

  14. Intermediation Costs and Financial Fragility

    OpenAIRE

    Kaplan, Cafer; Salman, Ferhan

    2007-01-01

    This paper studies implications of intermediation costs in credit markets. The presence of intermediation costs increases the amount of risky projects therefore results in financial fragility. Moreover, for an open economy that has a perfectly liberal capital account, prudent firms finance their projects from foreign markets therefore shrinking the domestic credit markets. The theoretical predictions of our model gains support by Turkish data for the 1991 – 2004 period. Data suggests that an ...

  15. UNION FORMATION IN FRAGILE FAMILIES*

    OpenAIRE

    Carlson, Marcia; McLanahan, Sara; England, Paula

    2004-01-01

    In this paper, we use data from a new longitudinal survey—the Fragile Families and Child Wellbeing Study—to examine union formation among unmarried parents who have just had a child together. We use multinomial logistic regression to estimate the effects of economic, cultural/interpersonal, and other factors on whether (relative to having no romantic relationship) parents are romantically involved living apart, cohabiting, or married to each other about one year after the child’s birth. Net o...

  16. Resilience and the Fragile City

    OpenAIRE

    John de Boer

    2015-01-01

    Humanitarian, security, and development actors are witnessing two distinct but intertwined trends that will have a dramatic impact on their operations. The first relates to the fact that the locus of global poverty and vulnerability to disaster are increasingly concentrated in fragile and conflict affected states. The second trend is associated with the notion that the world has entered a period of unprecedented urbanization. For the first time in history, more people live inside urban centre...

  17. Study on seismic equipment fragility analysis method

    International Nuclear Information System (INIS)

    Vulnerable points of nuclear power plants can be found through seismic PSA which is an effective method to evaluate the seismic effect on nuclear power plants, and fragility analysis is one important step for seismic PSA. In this paper, the concept of seismic equipment fragility is introduced, the mathematic model of seismic fragility is given, the determination of equipment failure modes is discussed, fragility analysis variables and methods (i. e. method based-on analysis and method based-on dynamic testing) are mainly studied, and finally median fragility, the distribution of randomness and uncertainty and HCLPF capacity can be calculated by formulations. On the other hand, when developing seismic fragility, there are three types of information that can be relied on: data from real earthquake experience, test data and analysis data, and this data used in specific nuclear plant need to be collected and completed. (authors)

  18. Jamming, Force Chains and Fragile Matter

    OpenAIRE

    Cates, M. E.; Wittmer, J.; Bouchaud, J. P.; Claudin, P.

    1998-01-01

    We consider materials whose mechanical integrity is the result of a jamming process. We argue that such media are generically "fragile": unable to support certain types of incremental loading without plastic rearrangement. Fragility is linked to the marginal stability of force chain networks within the material. Such ideas may be relevant to jammed colloids and poured sand. The crossover from fragile (when particles are rigid) to elastoplastic behavior is explored.

  19. Genotype prediction in the fragile X syndrome.

    OpenAIRE

    Hirst, M C; Nakahori, Y; Knight, S J; Schwartz, C.; Thibodeau, S.N.; Roche, A; Flint, T J; Connor, J M; Fryns, J P; Davies, K E

    1991-01-01

    Fragile X positive, mentally retarded males have been shown to have an insertion or amplification of DNA sequences at, or close to, the site of expression of the fragile site. We show here the application of the detection of such changes to the diagnosis of affected males and female carriers and the identification of normal transmitting males. One fragile X negative male with the clinical features of the Martin-Bell syndrome also possesses an inserted/amplified DNA sequence. The implications ...

  20. Lack of significant association between spina bifida and the fragile X syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Schiano, C.M. [United Cerebral Palsy of Nassau County, Roosevelt, NY (United States); Demb, H.B. [Albert Einstein College of Medicine, Bronx, NY (United States); Brown, W.T. [Inst. for Basic Research, Staten Island, NY (United States)

    1995-12-04

    Folic acid is involved in two common disorders associated with developmental disabilities. Spina bifida is a malformation that may be associated with mental retardation, learning disabilities, and epilepsy. Its incidence can be reduced by the ingestion of folic acid before, and at the time of, conception. The fragile X syndrome is a genetic disorder which is the most common form of inherited mental retardation. This disorder can be diagnosed by the induction of fragile sites on the X chromosome which is cultured in a medium deficient in folic acid. In several studies, folic acid was reported to alleviate some of the developmental and behavioral manifestations associated in the fragile X syndrome, while in others, it has no effect. 9 refs.

  1. Mapping of human chromosomal regions related to neoplasia: evidence from chromosomes 1 and 17

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J.D.

    1977-12-01

    In clonal aberrations leading to an excess or partial excess of chromosome I, trisomy for bands 1q25-1q32 was noted in the myeloid cells from all of 34 patients who had various disorders such as acute leukemia, polycythemia vera, and myelofibrosis. This was not the result of a particularly fragile site in that region of the chromosome because the break points in reciprocal translocations that involve it occurred almost exclusively in the short arm. Two consistent rearrangements that have been observed in chromosome 17 produced either duplication of the entire long arm or a translocation of the distal portion of the long arm to chromosome 15. The nonrandom chromosomal changes found in hematologic disorders can now be correlated with the gene loci on these chromosomes or chromosomal segments. Seventy-five genes related to various metabolic enzymes have been mapped; it may be significant that chromosomes carrying gene loci related to nucleic acid metabolism are more frequently involved in hematologic disorders (and other malignancies as well) than are gene loci related to intermediary or carbohydrate metabolism. Furthermore, the known virus-human chromosome associations are closely correlated with the chromosomes affected in hematologic disorders. If one of the effects of carcinogens (including viruses) is to activate genes that regulate host cell DNA synthesis, and if translocations or duplications of specific chromosomal segments produce the same effect, then either of these mechanisms might provide the affected cell with a proliferative advantage.

  2. Preferential integration of a transfected marker gene into spontaneously expressed fragile sites of a breast cancer cell line.

    Science.gov (United States)

    Matzner, Isabel; Savelyeva, Larissa; Schwab, Manfred

    2003-01-28

    Common fragile sites are non-randomly distributed unstable chromosomal regions thought to be hot spots for recombination. They appear as gaps, breaks and triradial figures when cells are cultured under conditions that inhibit replication or repair of DNA. The removal of replication-inhibitory challenges is followed by repair activation to restore the DNA damage at the fragile site. The breast cancer cell line MDA-MB-436 has a spontaneous and non-random expression pattern of fragile sites that appear to be related to the complex pattern of chromosomal rearrangements. The high frequency of which fragile sites are spontaneously activated should make MDA-MB-436 cells a powerful tool to study in greater detail the DNA sequences of a multiplicity of fragile sites. Here, we have explored if the DNA at spontaneously activated fragile sites in MDA-MB-436 cells can be genetically tagged by the repair-mediated insertion of an exogenously supplied drug resistance gene. The cells were transfected with pSV2Neo, stably transfected clones were selected with neomycin, and the sites of pSV2Neo integration were determined by fluorescent in situ hybridization. Eighty-eight of 100 isolated clones had a non-random distribution of a total of 112 pSV2Neo integrations. Of these, 95 integrations (85%) coincide with the position at which non-random gaps and breaks appear in the MDA-MB-436 cells. Forty-nine (44%) of the 112 integrations appeared to be at position of known fragile sites, 46 (41%) were at the non-random chromosomal sites not previously described as "true" fragile sites. It is possible, however, that these non-random instabilities signal of genomic regions equivalent to fragile sites, that either have not previously been detected due to low level expression or that are activated in a tissue- or cell-type-specific manner. Collectively, our results show a preferential integration of exogenous DNA into fragile sites and other non-random regions of high genomic instability in MDA

  3. Development Strategies - The Future of Fragile States?

    OpenAIRE

    Clausen, Bo; Østerholt Jensen, Jeppe; Thurøe, Tess; Møllegaard Nielsen, Stefanie

    2013-01-01

    Taking a point of departure in a reflection on the future of fragile states, this project aims at proposing a theoretical framework for how to most effectively generate development in fragile states. The international development strategy of the Millennium Development Goals and the New Deal for Engagement in Fragile States will be used as empirical data due to representing, respectively, a one-fits-all strategy to development and a ‘new deal’ on how to engage in fragile states before being ab...

  4. What Should You Know about Fragile X Syndrome (FXS)?

    Science.gov (United States)

    ... is working to learn more about fragile X syndrome and fragile X-associated disorders to improve the health and well- ... Overview of other conditions that often occur with fragile X syndrome. Share with Your Friends How can my child ...

  5. Seismic fragility of nuclear power plant components (Phase 2): A fragility handbook on eighteen components

    International Nuclear Information System (INIS)

    Fragility estimates of seven equipment classes were published in earlier reports. This report presents fragility analysis results from eleven additional equipment categories. The fragility levels are expressed in probabilistic terms. For users' convenience, this concluding report includes a summary of fragility results of all eighteen equipment classes. A set of conversion factors based on judgment is recommended for use of the information for early vintage equipment. The knowledge gained in conducting the Component Fragility Program and similar other programs is expected to provide a new direction for seismic verification and qualification of equipment. 15 refs., 12 tabs

  6. Reversing the Effects of Fragile X Syndrome

    Science.gov (United States)

    Ogren, Marilee P.; Lombroso, Paul J.

    2008-01-01

    A research on how synaptic plasticity is abnormally regulated in fragile X syndrome and how this abnormality can be reversed by therapeutic interventions is presented. Fragile X syndrome is a disorder of synaptic plasticity that contributes to abnormal development and interferes with normal learning and memory.

  7. Speech Fluency in Fragile X Syndrome

    Science.gov (United States)

    Van Borsel, John; Dor, Orianne; Rondal, Jean

    2008-01-01

    The present study investigated the dysfluencies in the speech of nine French speaking individuals with fragile X syndrome. Type, number, and loci of dysfluencies were analysed. The study confirms that dysfluencies are a common feature of the speech of individuals with fragile X syndrome but also indicates that the dysfluency pattern displayed is…

  8. Cytogenetic abnormalities and fragile-x syndrome in Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Reddy Kavita S

    2005-01-01

    Full Text Available Abstract Background Autism is a behavioral disorder with impaired social interaction, communication, and repetitive and stereotypic behaviors. About 5–10 % of individuals with autism have 'secondary' autism in which an environmental agent, chromosome abnormality, or single gene disorder can be identified. Ninety percent have idiopathic autism and a major gene has not yet been identified. We have assessed the incidence of chromosome abnormalities and Fragile X syndrome in a population of autistic patients referred to our laboratory. Methods Data was analyzed from 433 patients with autistic traits tested using chromosome analysis and/or fluorescence in situ hybridization (FISH and/or molecular testing for fragile X syndrome by Southern and PCR methods. Results The median age was 4 years. Sex ratio was 4.5 males to 1 female [354:79]. A chromosome (cs abnormality was found in 14/421 [3.33 %] cases. The aberrations were: 4/14 [28%] supernumerary markers; 4/14 [28%] deletions; 1/14 [7%] duplication; 3/14 [21%] inversions; 2/14 [14%] translocations. FISH was performed on 23 cases for reasons other than to characterize a previously identified cytogenetic abnormality. All 23 cases were negative. Fragile-X testing by Southern blots and PCR analysis found 7/316 [2.2 %] with an abnormal result. The mutations detected were: a full mutation (fM and abnormal methylation in 3 [43 %], mosaic mutations with partial methylation of variable clinical significance in 3 [43%] and a permutation carrier [14%]. The frequency of chromosome and fragile-X abnormalities appears to be within the range in reported surveys (cs 4.8-1.7%, FRAX 2–4%. Limitations of our retrospective study include paucity of behavioral diagnostic information, and a specific clinical criterion for testing. Conclusions Twenty-eight percent of chromosome abnormalities detected in our study were subtle; therefore a high resolution cytogenetic study with a scrutiny of 15q11.2q13, 2q37 and Xp23

  9. Novel Polymorphism in the FMR1 Gene Resulting in a “Pseudodeletion” of FMR1 in a Commonly Used Fragile X Assay

    OpenAIRE

    Daly, Thomas M.; Rafii, Arash; Martin, Rick A.; Zehnbauer, Barbara A.

    2000-01-01

    The fragile X syndrome is the most commonly inherited cause of mental retardation. Genetic diagnosis of this disease relies on the detection of triplet repeat expansion in the FMR1 gene on the X chromosome. Although the majority of disease in fragile X patients is due to mutations involving triplet repeat expansion, deletion of various portions of FMR1 has also been described in association with the fragile X syndrome. Here we describe a rare polymorphism in the noncoding region of FMR1 that ...

  10. Event-related potential alterations in fragile X syndrome

    Directory of Open Access Journals (Sweden)

    Inga Sophia eKnoth

    2012-09-01

    Full Text Available Fragile X Syndrome (FXS is the most common form of X-linked intellectual disability, associated with a wide range of cognitive and behavioural impairments. FXS is caused by a trinucleotide repeat expansion in the FMR1 gene located on the X-chromosome. FMR1 is expected to prevent the expression of the fragile X mental retardation protein (FMRP, which results in altered structural and functional development of the synapse, including a loss of synaptic plasticity. This review aims to unveil the contribution of electrophysiological signal studies for the understanding of the information processing impairments in FXS patients. We discuss relevant event-related potential (ERP studies conducted with full mutation FXS patients and clinical populations sharing symptoms with FXS in a developmental perspective. Specific deviances found in FXS ERP profiles are described. Alterations are reported in N1, P2, Mismatch Negativity (MMN, N2 and P3 components in FXS compared to healthy controls. Particularly, deviances in N1 and P2 amplitude seem to be specific to FXS. The presented results suggest a cascade of impaired information processes that are in line with symptoms and anatomical findings in FXS.

  11. Molecular/clinical correlations in females with fragile X

    Energy Technology Data Exchange (ETDEWEB)

    Sobesky, W.E.; Riddle, J.; Hagerman, R.J. [Children`s Hospital, Denver, CO (United States)] [and others

    1996-08-09

    Females who are affected by fragile X syndrome (FXS) can have significant physical, neuropsychological and emotional involvement. This study was designed to explore the relationships between these three domains and to learn how the degree of involvement in each of these phenotypic areas relates to molecular parameters including CGG repeat length and activation ratio (the proportion of normal FMR1 alleles on the active X chromosome). Three groups of females were studied: 35 women who grew up in a fragile X family but do not carry an FMR1 mutation, 92 women with a premutation, and 29 women with a full mutation. Correlations between neurocognitive, physical and emotional traits were calculated for each of the three groups. Within the full mutation group significant correlations were seen between schizotypal traits and full scale IQ. The Lie scale was significantly correlated with the physical findings index. The activation ratio correlated significantly with the measure of executive function (r = .50, P = .01). There was a trend toward correlations of activation ratio with the physical index score, outer ear prominence and IQ. CGG repeat number significantly correlated only with the physical index (r = .44, P = .0 1). Thus, activation ratio may be the more pertinent molecular parameter in full mutation women in determining the degree of cognitive and physical phenotypic involvement. 29 refs., 2 tabs.

  12. Chromosomal aberration

    International Nuclear Information System (INIS)

    Chromosomal aberrations are classified into two types, chromosome-type and chromatid-type. Chromosom-type aberrations include terminal deletion, dicentric, ring and interstitial deletion, and chromatid-type aberrations include achromatic lesion, chromatid deletion, isochromatid deletion and chromatid exchange. Clastogens which induce chromosomal aberration are divided into ''S-dependent'' agents and ''S-independent''. It might mean whether they can induce double strand breaks independent of the S phase or not. Double strand breaks may be the ultimate lesions to induce chromosomal aberrations. Caffeine added even in the G2 phase appeared to modify the frequency of chromatid aberrations induced by X-rays and mitomycin C. Those might suggest that the G2 phase involves in the chromatid aberration formation. The double strand breaks might be repaired by ''G2 repair system'', the error of which might yield breakage types of chromatid aberrations and the by-pass of which might yield chromatid exchanges. Chromosome-type aberrations might be formed in the G1 phase. (author)

  13. Cytogenetic effects of radiotherapy. Breakpoint distribution in induced chromosome aberrations

    International Nuclear Information System (INIS)

    A total of 660 breakpoints were identified in the chromosome aberrations detected in lymphocytes from cancer patients after radiotherapy. The results show that chromosomes 1, 3, and 7 were significantly more affected than other chromosomes by ionizing radiation in vivo. Chromosome arms 1p, 1q, 7q, and 11p were also significantly more affected. Some bands also showed a special sensitivity to radiation, and band 1q32 was the most affected. This band is proposed as a hot point for the clastogenic effect of ionizing radiation. A significant clustering of breakpoints in G bands was also found, especially at the telomeres, as previously described by other authors. Clustering of breakpoints was also observed in bands where fragile sites, protooncogenes, breakpoints involved in chromosomal cancer rearrangements, and breakpoints involved in chromosomal evolution of the Hominoidea are located

  14. Behavioral Phenotype of Fragile X Syndrome in Adolescence and Adulthood

    Science.gov (United States)

    Smith, Leann E.; Barker, Erin T.; Seltzer, Marsha Mailick; Abbeduto, Leonard; Greenberg, Jan S.

    2012-01-01

    The present study explored the behavioral profile of individuals with fragile X syndrome during adolescence and adulthood. Individuals with both fragile X syndrome and autism (n = 30) were compared with (a) individuals diagnosed with fragile X syndrome (but not autism; n = 106) and (b) individuals diagnosed with autism (but not fragile X syndrome;…

  15. Guidelines for the diagnosis of fragile X syndrome. National Fragile X Foundation.

    OpenAIRE

    Oostra, B A; Jacky, P B; Brown, W T; Rousseau, F.

    1993-01-01

    Direct DNA analysis of the fragile X mutation has become available with the isolation of DNA probes that detect the unstable DNA sequence containing the CGG repeat. We present the various alternatives of combinations of probes and enzymes that can be used for the diagnosis of fragile X syndrome. An overview is given of all the different available probes. A different protocol is presented for postnatal and prenatal diagnosis of fragile X syndrome. This includes Southern blot analysis as well a...

  16. A clinical study of mentally retarded children with fragile X syndrome inSaudi Arabia

    International Nuclear Information System (INIS)

    Studies on fragile X syndrome are scarce in Saudi Arabia and othercountries of the Arabian Peninsula. The few studies previously done haveeither been in the form of case reports or those performed oninstitutionalized mentally retarded patients. The aim of this study was todetermine the prevalence of fragile X syndrome among cases with mentalretardation who have been referred to the pediatric neurology clinics of KingKhalid University Hospital (KKUH) in Riyadh. Cytogenetic studies wereperformed in 94 cases that were referred to the pediatric neurology clinicsof KKUH because of mental retardation and/or delayed milestones ofdevelopment, from July 1995 to December 1997. Six male probands (6.4%) showedthe classic fragile X chromosome and another six (including a four year oldgirl) were detected, following extension of the cytogenetic studies to all 32first-degree relatives. Affection of more than one sibling was ascertained infour families. One family had four brothers with fragile X syndrome, whereasanother formed part of a large kindred with twelve males and five females whowere mentally retarded. A clinical, physical and psychological screeningchecklist was applied to the eleven affected males. Large testicular size,long face and short attention span were the most frequent features and eachwas detected in nine patients (82%). Pes planus and history of delayed speechwere found in eight patients (73%). The study showed that the fragile Xsyndrome clinical screening checklist has been applied in other populationsmight equally valuable and applicable among the population of Saudi Arabia.However, the presence of pale blue eyes can be excluded and more weight givento positive family history of mental to the most common clinical diagnosticfeatures of fragile X syndrome. (author)

  17. Mexico's crisis: financial modernisation and financial fragility

    OpenAIRE

    G. J. LÓPEZ

    1997-01-01

    The work seeks to analyse Mexico's recent exchange-rate crisis in relation to the debate on financial modernisation and external financial fragility. The author reviews some key features of Mexico's 1988-1994 economic recovery before analysing some aspects of the country's evolution in the light of the financial modernisation debate. An explanation of the crisis in which Mexico's external financial fragility is emphasised is provided. Finally, the relationship between financial modernisation ...

  18. Cardiac abnormalities in the fragile X syndrome.

    OpenAIRE

    Sreeram, N.; WREN, C.; Bhate, M; Robertson, P.; Hunter, S

    1989-01-01

    Twenty three patients with fragile X syndrome underwent cardiovascular assessment. Echocardiography showed dilatation of the aortic root in 12 (52%) and mitral valve prolapse in five (22%), four of whom had an apical mid-systolic click on auscultation. Patients with fragile X syndrome have cardiac defects similar to those seen in other disorders of connective tissue such as Marfan's syndrome and Ehlers-Danlos syndrome. These, and other somatic features, suggest an underlying connective tissue...

  19. Origins of Epilepsy in Fragile X Syndrome

    OpenAIRE

    Hagerman, Paul J.; STAFSTROM, CARL E

    2009-01-01

    Fragile X syndrome is the leading heritable form of cognitive impairment and the leading known monogenic disorder associated with autism. Roughly one-quarter of children with this disorder have seizures, most of which are relatively benign and are resolved beyond childhood. Because of the prevalence of fragile X syndrome, numerous animal models have been developed and electrophysiological studies have taken place to investigate its pathogenesis. The investigations have yielded a wealth of inf...

  20. Fragile African States: What Should Donors Do?

    OpenAIRE

    Collier, Paul

    2014-01-01

    1. IntroductionNecessarily, all donors will focus increasingly on fragile states. The more successful countries in Africa have achieved growing tax bases and are consequently now gaining access to global capital markets. For such countries, aid is becoming marginal. In contrast, fragile states, by the nature of their condition, have small tax bases and face risks which deter private capital: for them aid remains potentially important. Not only do donors provide a substantial proportion of gov...

  1. 'Fragile States' : introducing a political concept

    OpenAIRE

    Grimm, Sonja; Lemay-Hébert, Nicolas; Nay, Olivier

    2014-01-01

    The special issue 'Fragile States: A Political Concept’ investigates the emergence, dissemination and reception of the notion of ‘state fragility’. It analyses the process of conceptualisation, examining how the ‘fragile states’ concept was framed by policy makers to describe reality in accordance with their priorities in the fields of development and security. The contributors to the issue investigate the instrumental use of the ‘state fragility’ label in the legitimisation of Western polic...

  2. The DNA sequence, annotation and analysis of human chromosome 3

    DEFF Research Database (Denmark)

    Muzny, Donna M; Scherer, Steven E; Kaul, Rajinder;

    2006-01-01

    chromosomes. Chromosome 3 comprises just four contigs, one of which currently represents the longest unbroken stretch of finished DNA sequence known so far. The chromosome is remarkable in having the lowest rate of segmental duplication in the genome. It also includes a chemokine receptor gene cluster as well...... as numerous loci involved in multiple human cancers such as the gene encoding FHIT, which contains the most common constitutive fragile site in the genome, FRA3B. Using genomic sequence from chimpanzee and rhesus macaque, we were able to characterize the breakpoints defining a large pericentric...

  3. 智力低下儿童X染色体脆性位点及FMR1基因突变的研究%Study on X chromosome fragile site and FMR1 gene mutation in children with metal retardation

    Institute of Scientific and Technical Information of China (English)

    陈冬萍; 曾素芬; 张素贞

    2014-01-01

    目的 探讨智力低下(Mental Retardation,MR)儿童染色体遗传学原因.方法 选择智力低下患儿及其父母作为研究对象,采用细胞遗传学方法检测X染色体脆性位点,以及采用多重连接探针扩增(Multiplex ligation-dependent Probe Amplificaton,MLPA)技术分析FMRl (Fragile X mental retardation gene 1)基因的缺失与重复.结果 266例患儿共查出X脆性综合征18例,与父母同一脆性位点的7例,其中6例为FMR1基因突变.结论 MR患儿可与表型正常的父母有同一X染色体脆性位点,但FMR1基因突变是X脆性综合征(Fragile X syndrome,Fra X)临床表型的真正原因.

  4. Synthetic chromosomes.

    Science.gov (United States)

    Schindler, Daniel; Waldminghaus, Torsten

    2015-11-01

    What a living organism looks like and how it works and what are its components-all this is encoded on DNA, the genetic blueprint. Consequently, the way to change an organism is to change its genetic information. Since the first pieces of recombinant DNA have been used to transform cells in the 1970s, this approach has been enormously extended. Bigger and bigger parts of the genetic information have been exchanged or added over the years. Now we are at a point where the construction of entire chromosomes becomes a reachable goal and first examples appear. This development leads to fundamental new questions, for example, about what is possible and desirable to build or what construction rules one needs to follow when building synthetic chromosomes. Here we review the recent progress in the field, discuss current challenges and speculate on the appearance of future synthetic chromosomes. PMID:26111960

  5. Isolation and genetic charac-terization of a fragile plantmutant in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The fragile rice mutant was isolated from an M2 population of indica variety Shuang Ke Zao (SKZ) treated with (-rays, and designated as fp1 (fragile plant 1) because of its fragile leaves and culms. To map FP1 locus, an F2 mapping population was derived from a cross between the fp1 and C-bao, a polymorphic japonic variety. The primary mapping result places the FP1 locus in an interval between two molecular markers, microsatellite marker RM16 (3.1 cM proximal to FP1) and STS marker G144a (9.1 cM distal to FP1) in the centromere region of chromosome 3. A CAPS marker C524a was further developed between RM16 and G144a, with 0.4 cM genetic distances to the FP1 locus, providing a practical starting point for constructing a BAC contig spanning the FP1 locus and cloning the fp1 gene. Allelism test demonstrated that fp1 is allelic to bc1, a fragile rice mutant reported previously.

  6. Repeat-mediated genetic and epigenetic changes at the FMR1 locus in the Fragile X-related disorders

    Directory of Open Access Journals (Sweden)

    Karen eUsdin

    2014-07-01

    Full Text Available AbstractThe Fragile X-related disorders are a group of genetic conditions that include the neurodegenerative disorder, Fragile X-associated tremor and ataxia syndrome (FXTAS, the fertility disorder, Fragile X-associated primary ovarian insufficiency (FXPOI and the intellectual disability, Fragile X syndrome (FXS. The pathology in all these diseases is related to the number of CGG/CCG-repeats in the 5’ UTR of the FMR1 gene. The repeats are prone to continuous expansion and the increase in repeat number has paradoxical effects on gene expression increasing transcription on mid-sized alleles and decreasing it on longer ones. In some cases the repeats can simultaneously both increase FMR1 mRNA production and decrease the levels of the FMR1 gene product, FMRP. Since FXTAS and FXPOI result from the deleterious consequences of the expression of elevated levels of FMR1 mRNA and FXS is caused by reduced FMRP levels, the clinical picture is turning out to be more complex than once appreciated. Added complications are generated by the fact that increasing repeat numbers make the alleles somatically unstable, generating resulting in individuals sometimes having a complex mixture of different sized alleles. Furthermore, it has become apparent that the eponymous fragile site, once thought to be no more than a useful diagnostic criterion, may have clinical consequences for females who inherit chromosomes that express this site. This review will cover what is currently known about the mechanisms responsible for repeat instability, for the repeat-mediated epigenetic changes that affect expression of the FMR1 gene, and for chromosome fragility. It will also touch on what current and future options are for ameliorating some of these effects.

  7. Fragile X syndrome associated with tic disorders.

    Science.gov (United States)

    Schneider, Susanne A; Robertson, Mary M; Rizzo, Renata; Turk, Jeremy; Bhatia, Kailash P; Orth, Michael

    2008-06-15

    Movement disorders other than late onset tremor-ataxia in association with fragile X syndrome, the most common identifiable cause of inherited mental retardation, seem to be rare. Here we describe five male patients from three unrelated families with fragile X syndrome that presented with motor and phonic tics. Clinically, 4 patients fulfilled diagnostic criteria for Gilles de la Tourette syndrome (GTS) while 1 patient would have been diagnosed with an adult onset tic disorder. However, in all patients onset of tics was considerably later than in typical GTS. Three patients had atypical tics and two patients reported waxing and waning of tic intensity over time. Four of the 5 patients showed clinical signs typical of fragile X syndrome, in particular dysmorphic features, learning difficulties and speech and language problems that required special treatment. All patients had co-morbidities common to both GTS and fragile X syndrome. We suggest considering fragile X syndrome in GTS complicated by co-morbidity with late onset of atypical tics, in particular when learning disability and dysmorphic features are present. PMID:18383111

  8. Component fragilities. Data collection, analysis and interpretation

    International Nuclear Information System (INIS)

    As part of the component fragility research program sponsored by the US NRC, BNL is involved in establishing seismic fragility levels for various nuclear power plant equipment with emphasis on electrical equipment. To date, BNL has reviewed approximately seventy test reports to collect fragility or high level test data for switchgears, motor control centers and similar electrical cabinets, valve actuators and numerous electrical and control devices, e.g., switches, transmitters, potentiometers, indicators, relays, etc., of various manufacturers and models. BNL has also obtained test data from EPRI/ANCO. Analysis of the collected data reveals that fragility levels can best be described by a group of curves corresponding to various failure modes. The lower bound curve indicates the initiation of malfunctioning or structural damage, whereas the upper bound curve corresponds to overall failure of the equipment based on known failure modes occurring separately or interactively. For some components, the upper and lower bound fragility levels are observed to vary appreciably depending upon the manufacturers and models. For some devices, testing even at the shake table vibration limit does not exhibit any failure. Failure of a relay is observed to be a frequent cause of failure of an electrical panel or a system. An extensive amount of additional fregility or high level test data exists

  9. Variation at the fragile X locus does not influence susceptibility to bipolar disorder

    Energy Technology Data Exchange (ETDEWEB)

    Craddock, N.; Daniels, J.; McGuffin, P. [Univ. of Wales College of Medicine, Cardiff (United Kingdom)] [and others

    1994-06-15

    Over the last 20 years several pedigrees have been reported which are suggestive of linkage between susceptibility to bipolar disorder and markers on chromosome Xq28. Other workers have failed to replicate these reports and the methodology of the positive reports has been criticized. Recently there have been several reports of an association between fragile X (FRA(X)) and affective disorder within families and in unrelated individuals compared with controls. Such reports could be consistent with the Xq28 marker reports because FRA(X) maps to Xq27.3. We report a study at the FRA(X) CGG repeat locus in 79 unrelated Caucasian bipolar probands without fragile X syndrome and 77 unrelated controls. We found no evidence that variation at this locus confers susceptibility to bipolar disorder. 28 refs., 1 fig.

  10. Comments on seismic fragility of nuclear power plant components

    International Nuclear Information System (INIS)

    Recent advances in the prediction of seismic hazard have resulted in concern that some nuclear power plant sites could experience seismic events in excess of their design bases. This concern, along with the considerable interest that has arisen from interpretations of probabilistic risk assessments, has resulted in significant professional activity in the prediction of fragilities of structures and equipment. Several programs sponsored by utilities, regulators and EPRI are addressing many of the aspects of seismic fragility. This paper discusses the current state-of-the-art in fragility prediction, fragility data sources, relative seismic ruggedness of power plant components, problem areas in fragility prediction, and suggested future work in fragility testing

  11. Kerr black holes are not fragile

    Energy Technology Data Exchange (ETDEWEB)

    McInnes, Brett, E-mail: matmcinn@nus.edu.sg [Centro de Estudios Cientificos (CECs), Valdivia (Chile); National University of Singapore (Singapore)

    2012-04-21

    Certain AdS black holes are 'fragile', in the sense that, if they are deformed excessively, they become unstable to a fundamental non-perturbative stringy effect analogous to Schwinger pair-production [of branes]. Near-extremal topologically spherical AdS-Kerr black holes, which are natural candidates for string-theoretic models of the very rapidly rotating black holes that have actually been observed to exist, do represent a very drastic deformation of the AdS-Schwarzschild geometry. One therefore has strong reason to fear that these objects might be 'fragile', which in turn could mean that asymptotically flat rapidly rotating black holes might be fragile in string theory. Here we show that this does not happen: despite the severe deformation implied by near-extremal angular momenta, brane pair-production around topologically spherical AdS-Kerr-Newman black holes is always suppressed.

  12. Practical Approach to Fragility Analysis of Bridges

    Directory of Open Access Journals (Sweden)

    Yasamin Rafie Nazari

    2012-12-01

    Full Text Available Damages during past earthquakes reveal seismic vulnerability of bridge structures and the necessity of probabilistic approach toward seismic performance evaluation of bridges and its interpretation in terms of decision variables such as repair cost, downtime and life loss. This Procedure involves hazard analysis, structural analysis, damage analysis and loss analysis. The purpose of present study is reviewing different methods developed to derive fragility curves for damage analysis of bridges and demonstrating a simple procedure for fragility analysis using Microsoft Office Excel worksheet to reach probability of occurring predefined level of damage due to different levels of seismic demand parameters. The input of this procedure is the intensity of ground motion and the output is an appropriate estimate of the expected damage. Different observed damages of the bridges are discussed and compared the practical definition of damage states. Different methods of fragility analyses are discussed and a practical step by step example is illustrated.

  13. Genetic diagnosis in clinical psychiatry: A case report of a woman with a 47, XXX karyotype and Fragile X syndrome

    Directory of Open Access Journals (Sweden)

    Anthony M. Vandersteen

    2009-03-01

    Full Text Available Background and Objectives: A recent report highlighted the importance of considering a chromosomal abnormality in the differential diagnosis of adult clinical psychiatry. This case report illustrates the importance of considering Fragile X syndrome, an X-linked genetic disorder associated with psychiatric morbidities. Methods: A 45 years old woman was referred to the clinical genetics department by her psychiatrist for investigation of her gross obesity, hyperphagia, learning difficulties and affective disorder. Results: Cytogenetic analysis revealed a 47,XXX karyotype. Molecular testing identified an expansion of approximately 580 repeats in the FRAXA gene carried on two of her three copies of the X chromosome. Clinical evaluation revealed features consistent with the Prader-Willi like phenotype of Fragile X syndrome. Conclusions: It is important to consider molecular and cytogenetic testing in patients with dysmorphic features, complex neuro-behavioural profile and/or psychotic disorders in order to establish a causative diagnosis, provide adequate counselling and initiate cascade screening where applicable.

  14. Chromosome Microarray.

    Science.gov (United States)

    Anderson, Sharon

    2016-01-01

    Over the last half century, knowledge about genetics, genetic testing, and its complexity has flourished. Completion of the Human Genome Project provided a foundation upon which the accuracy of genetics, genomics, and integration of bioinformatics knowledge and testing has grown exponentially. What is lagging, however, are efforts to reach and engage nurses about this rapidly changing field. The purpose of this article is to familiarize nurses with several frequently ordered genetic tests including chromosomes and fluorescence in situ hybridization followed by a comprehensive review of chromosome microarray. It shares the complexity of microarray including how testing is performed and results analyzed. A case report demonstrates how this technology is applied in clinical practice and reveals benefits and limitations of this scientific and bioinformatics genetic technology. Clinical implications for maternal-child nurses across practice levels are discussed. PMID:27276104

  15. Biodiversity and its fragility in Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    PU Ying-shan; ZHANG Zhi-yi; PU Li-na; HUI Chao-mao

    2007-01-01

    In Yunnan, 8 major aspects of biodiversity and fragility in landforms, ecosystems, distribution populations, alien invasion, segregation, pollution and maladministration with various menace factors causing biodiversity loss have been described. It is revealed that the facts that the biodiversity and fragility coexists in this paper. Accordingly, 6 major countermeasures for effective conservation and rational utilization of the provincial biodiversity were suggested on the basis of thescientific development concepts, principles of nature protection,conservation biology, resource management and ethnobotany and present status in Yunnan with rich intangible resources such as climatic,ethnical and cultural diversity, etc.

  16. Aid and growth in fragile states

    OpenAIRE

    McGillivray, Mark; Feeny, Simon

    2008-01-01

    The literature on aid has come a long way in recent years, and as a result we now know much more about aid effectiveness than possibly ever before. But significant gaps in knowledge remain. One such gap is the effectiveness of aid in the so-called ‘fragile states’, countries with critically low policy and institutional performance ratings. The current paper addresses this void by examining possible links between aid and economic growth in fragile states. It finds that: (i) growth would have b...

  17. Genetic diagnosis in clinical psychiatry: A case report of a woman with a 47, XXX karyotype and Fragile X syndrome

    OpenAIRE

    Vandersteen, Anthony M.; David Moore; Celia Donaghue; Neil MacFarlane; Dragana Josifova

    2009-01-01

    Background and Objectives: A recent report highlighted the importance of considering a chromosomal abnormality in the differential diagnosis of adult clinical psychiatry. This case report illustrates the importance of considering Fragile X syndrome, an X-linked genetic disorder associated with psychiatric morbidities. Methods: A 45 years old woman was referred to the clinical genetics department by her psychiatrist for investigation of her gross obesity, hyperphagia, learning difficulties and...

  18. Variability in the incidence of miRNAs and genes in fragile sites and the role of repeats and CpG islands in the distribution of genetic material.

    Directory of Open Access Journals (Sweden)

    Alessandro Laganà

    Full Text Available BACKGROUND: Chromosomal fragile sites are heritable specific loci especially prone to breakage. Some of them are associated with human genetic disorders and several studies have demonstrated their importance in genome instability in cancer. MicroRNAs (miRNAs are small non-coding RNAs responsible of post-transcriptional gene regulation and their involvement in several diseases such as cancer has been widely demonstrated. The altered expression of miRNAs is sometimes due to chromosomal rearrangements and epigenetic events, thus it is essential to study miRNAs in the context of their genomic locations, in order to find significant correlations between their aberrant expression and the phenotype. PRINCIPAL FINDINGS: Here we use statistical models to study the incidence of human miRNA genes on fragile sites and their association with cancer-specific translocation breakpoints, repetitive elements, and CpG islands. Our results show that, on average, fragile sites are denser in miRNAs and also in protein coding genes. However, the distribution of miRNAs and protein coding genes in fragile versus non-fragile sites depends on chromosome. We find also a positive correlation between fragility and repeats, and between miRNAs and CpG islands. CONCLUSION: Our results show that the relationship between site fragility and miRNA density is far more complex than previously thought. For example, we find that protein coding genes seem to be following similar patterns as miRNAs, if considered their overall distribution. However, once we allow for differences at the chromosome level in our statistical analysis, we find that distribution of miRNA and protein coding genes in fragile sites is very different from that of miRNA. This is a novel result that we believe may help discover new potential correlations between the localization of miRNAs and their crucial role in biological processes and in the development of diseases.

  19. Fragile X-Associated Tremor and Ataxia Syndrome (FXTAS)

    Science.gov (United States)

    ... Resources and Publications Fragile X-Associated Tremor and Ataxia Syndrome (FXTAS): Overview Skip sharing on social media ... this: Page Content Fragile X-associated tremor and ataxia syndrome (FXTAS) is a late-onset condition (occurs ...

  20. What Are the Treatments for Fragile X Syndrome?

    Science.gov (United States)

    ... Resources and Publications What are the treatments for Fragile X syndrome? Skip sharing on social media links Share this: Page Content There is no single treatment for Fragile X syndrome, but there are treatments that help minimize the ...

  1. How Do Health Care Providers Diagnose Fragile X Syndrome?

    Science.gov (United States)

    ... and Publications How do health care providers diagnose Fragile X syndrome? Skip sharing on social media links Share this: ... information helps families and providers to prepare for Fragile X syndrome and to intervene as early as possible. Possible ...

  2. A Way to Effective Service Delivery in Fragile States

    OpenAIRE

    Swaminath, Anoop

    2009-01-01

    Success and effectiveness in service delivery can establish the legitimacy of a fragile state’s government, and thereby reduce its fragility. Public-private partnerships offer a viable approach to achieving this goal.

  3. BANKING SYSTEM FRAGILITY: CASE OF THE REPUBLIC OF MOLDOVA

    OpenAIRE

    Dorina CLICHICI

    2014-01-01

    The paper studied the determinants of Moldovan banking system fragility. It underlines the existing researches into the empirical determinants of banking fragility. The analysis revealed that there are numerous channels through which weaknesses within the macroeconomic conditions and structural characteristics might increase banking system fragility. The main macroeconomic determinants which may have an impact on Moldovan banking system fragility are: excessive domestic liquidity, pro-cyclica...

  4. Behavioral Phenotype of Fragile X Syndrome in Adolescence and Adulthood

    OpenAIRE

    Smith, Leann E.; Barker, Erin T.; Seltzer, Marsha Mailick; Abbeduto, Leonard; Greenberg, Jan S.

    2012-01-01

    The present study explored the behavioral profile of individuals with fragile X syndrome during adolescence and adulthood. Individuals with both fragile X syndrome and autism (n = 30) were compared with (a) individuals diagnosed with fragile X syndrome (but not autism; n = 106) and (b) individuals diagnosed with autism (but not fragile X syndrome; n = 135) on measures of autism symptoms, adaptive functioning, behavior problems, and psychological symptoms. Results indicated that individuals du...

  5. Sovereignty in fragile states in the age of international intervention

    OpenAIRE

    Jensen, Maria Mørch

    2012-01-01

    This thesis examines what influence United Nations peacebuilding missions have on the sovereignty of fragile states in Africa. The starting point for the analysis is the nature of the fragile state and an examination of how the condition of fragility influences the presence of sovereignty in these states. The thesis distinguishes itself by recognising the relationship between the two entities and establishes an understanding of fragile state’s sovereignty as a tool for negotiation when it com...

  6. Psychiatric treatment with people displaced in or from fragile states

    Directory of Open Access Journals (Sweden)

    Verity Buckley

    2013-05-01

    Full Text Available A fragile state is not an ideal environment for any professional to work within` – psychiatric, medical or otherwise. Psychiatrists working to assess psychological distress and mental health in fragile states, or with refugees from fragile states, need to adopt flexible approaches.

  7. Psychiatric treatment with people displaced in or from fragile states

    OpenAIRE

    Verity Buckley

    2013-01-01

    A fragile state is not an ideal environment for any professional to work within` – psychiatric, medical or otherwise. Psychiatrists working to assess psychological distress and mental health in fragile states, or with refugees from fragile states, need to adopt flexible approaches.

  8. Multipartnered Fertility and Depression among Fragile Families

    Science.gov (United States)

    Turney, Kristin; Carlson, Marcia J.

    2011-01-01

    We used data from the Fragile Families and Child Wellbeing Study to examine the association between multipartnered fertility (MPF)--when parents have children with more than one partner--and depression. Random-effects models suggested that MPF is associated with a greater likelihood of depression, net of family structure and other covariates.…

  9. Essays on financial fragility and regulation

    NARCIS (Netherlands)

    Ma, K.

    2013-01-01

    This thesis investigates various issues in regulation, with three chapters on financial fragility and banking regulation, and one chapter on competition policy. Chapter 2 studies banks’ herding driven by their need for market liquidity, highlighting a trade-off between systemic risk and liquidity cr

  10. Modeling Family Adaptation to Fragile X Syndrome

    Science.gov (United States)

    Raspa, Melissa; Bailey, Donald, Jr.; Bann, Carla; Bishop, Ellen

    2014-01-01

    Using data from a survey of 1,099 families who have a child with Fragile X syndrome, we examined adaptation across 7 dimensions of family life: parenting knowledge, social support, social life, financial impact, well-being, quality of life, and overall impact. Results illustrate that although families report a high quality of life, they struggle…

  11. Emotion Potentiated Startle in Fragile X Syndrome

    Science.gov (United States)

    Ballinger, Elizabeth C.; Cordeiro, Lisa; Chavez, Alyssa D.; Hagerman, Randi J.; Hessl, David

    2014-01-01

    Social avoidance and anxiety are prevalent in fragile X syndrome (FXS) and are potentially mediated by the amygdala, a brain region critical for social behavior. Unfortunately, functional brain resonance imaging investigation of the amygdala in FXS is limited by the difficulties experienced by intellectually impaired and anxious participants. We…

  12. Fragile X Syndrome: An Aging Perspective

    Science.gov (United States)

    Schneider, Andrea; Ligsay, Andrew; Hagerman, Randi J.

    2013-01-01

    Cognitive and behavioral correlates of molecular variations related to the FMR1 gene have been studied rather extensively, but research about the long-term outcome in individuals with fragile X spectrum disorders remains sparse. In this review, we present an overview of aging research and recent findings in regard to cellular and clinical…

  13. Fragile states, collective identities and forced migration

    OpenAIRE

    Kelly Staples

    2013-01-01

    There has been a worrying tendency for the international communityto ignore questions of state capacity when enacting repatriations.Governance and the rule of law should be vital considerations inattempts to deal with forced migration in fragile states such as DRC.

  14. How to engage constructively with fragile states

    OpenAIRE

    Jon Bennett

    2013-01-01

    Donors have allocated increasing resources in fragile states tothe reform and/or rebuilding of the architecture of the state – suchas justice systems, the police and army, and the management ofministries – in efforts to support stability. This has been important for all sectors of society, including displaced people.

  15. Making human rights 'work' in fragile states

    OpenAIRE

    Dyrhagen, Gitte

    2008-01-01

    The thesis analyzes how Denmark as a donor government can best contribute to promote and protect human rights in "fragile states" which are characterized by their lack of capacity and willingness to undertake such duties. This is done by comparing central debates and analytical frameworks with two case studies, Afghanistan and Nepal.

  16. Bone mineral density testing after fragility fracture

    Science.gov (United States)

    Posen, Joshua; Beaton, Dorcas E.; Sale, Joanna; Bogoch, Earl R.

    2013-01-01

    Abstract Objective To determine the proportion of patients with fragility fractures who can be expected to have low bone mineral density (BMD) at the time of fracture and to assist FPs in deciding whether to refer patients for BMD testing. Data sources MEDLINE, EMBASE, and CINAHL were searched from the earliest available dates through September 2009. Study selection English-language articles reporting BMD test results of patients with fragility fractures who were managed in an orthopedic environment (eg, fracture clinic, emergency management by orthopedic surgeons, inpatients) were eligible for review. While the orthopedic environment has been identified as an ideal point for case finding, FPs are often responsible for investigation and treatment. Factors that potentially influenced BMD test results (eg, selection of fracture types, exclusion criteria) were identified. Studies with 2 or more selection factors of potential influence were flagged, and rates of low BMD were calculated including and excluding these studies. Synthesis The distribution of the proportion of persons with low BMD was summarized across studies using descriptive statistics. We calculated lower boundaries on this distribution, using standard statistical thresholds, to determine a lower threshold of the expected rate of low BMD. Conclusion Family physicians evaluating patients with fragility fractures can expect that at least two-thirds of patients with fragility fractures who are older than 50 years of age will have low BMD (T score ≤ −1.0). With this a priori expectation, FPs might more readily conduct a fracture risk assessment and pursue warranted fracture risk reduction strategies following fragility fracture. PMID:24336562

  17. The RBBP6/ZBTB38/MCM10 Axis Regulates DNA Replication and Common Fragile Site Stability

    Directory of Open Access Journals (Sweden)

    Benoit Miotto

    2014-04-01

    Full Text Available Faithful DNA replication is essential for the maintenance of genome integrity. Incomplete genome replication leads to DNA breaks and chromosomal rearrangements, which are causal factors in cancer and other human diseases. Despite their importance, the molecular mechanisms that control human genome stability are incompletely understood. Here, we report a pathway that is required for human genome replication and stability. This pathway has three components: an E3 ubiquitin ligase, a transcriptional repressor, and a replication protein. The E3 ubiquitin ligase RBBP6 ubiquitinates and destabilizes the transcriptional repressor ZBTB38. This repressor negatively regulates transcription and levels of the MCM10 replication factor on chromatin. Cells lacking RBBP6 experience reduced replication fork progression and increased damage at common fragile sites due to ZBTB38 accumulation and MCM10 downregulation. Our results uncover a pathway that ensures genome-wide DNA replication and chromosomal stability.

  18. X-radiation-induced chromosome breakage in retinoblastoma lymphocytes

    International Nuclear Information System (INIS)

    The authors have examined the spontaneous and X-radiation-induced chromosomal damage in normal humans and in patients with retinoblastoma using the BudR-Giemsa technique in lymphocytes cultured for 48 h. 9 sporadic unilateral non-hereditary cases, 11 hereditary cases and 20 healthy individuals were studied simultaneously. No difference in the spontaneous frequency of chromatid and chromosome aberrations was observed between patients and controls. The results suggest that: (a) There is no relationship between spontaneous chromosome fragility and retinoblastoma. (b) Sporadic unilateral non-hereditary retinoblastoma has normal chromosome sensitivity to X-irradiation. (c) Some hereditary cases of retinoblastoma are sensitive to X-rays while others behave like normals. A mutation or a submicroscopic deletion at a DNA repair locus which is independent of the retinoblastoma gene may cause this radiosensitivity. (Auth.)

  19. Fragility Index of block tailed vectors

    CERN Document Server

    Ferreira, Helena

    2011-01-01

    Financial crises are a recurrent phenomenon with important effects on the real economy. The financial system is inherently fragile and it is therefore of great importance to be able to measure and characterize its systemic stability. Multivariate extreme value theory provide us such a framework through the \\emph{fragility index} (Geluk \\cite{gel+}, \\emph{et al.}, 2007; Falk and Tichy, \\cite{falk+tichy1,falk+tichy2} 2010, 2011). Here we generalize this concept and contribute to the modeling of the stability of a stochastic system divided into blocks. We will find several relations with well-known tail dependence measures in literature, which will provide us immediate estimators. We end with an application to financial data.

  20. Abnormalities of chromosome No. 1: significance in malignant transformation

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, J.D.

    1978-01-01

    Studies of human hematologic malignancies have provided sufficient data not only for the identification of nonrandom abnormalities of whole chromosomes, but also for determination of the specific chromosome regions involved. In clonal aberrations leading to an excess of chromosome No. 1, or a partial excess of No. 1, trisomy for bands 1q25 to 1q32 was noted in the myeloid cells obtained from every one of 35 patients who had various disorders, such as acute leukemia, polycythemia vera, or myelofibrosis. Similar chromosome changes were a consistent finding in various solid tumors as well. This rearrangement was not the result of a particularly fragile site in that region of the chromosome, since the break points in reciprocal translocations that involve No. 1 occurred almost exclusively in the short arm. The nonrandom chromosome changes found in neoplastic cells can now be correlated with the gene loci on these chromosomes or chromosome segments as an attempt is made to identify specific genes that might be related to malignancy.

  1. Financial Fragility and the Exchange Rate Regime

    OpenAIRE

    Chang, Roberto; Velasco, Andres

    1998-01-01

    We study financial fragility, exchange rate crises and monetary policy in an open economy model in which banks are maturity transformers as in Diamond-Dybvig. The banking system, the exchange rate regime, and central bank credit policy are seen as parts of a mechanism intended to maximize social welfare; if the mechanism fails, banking crises and speculative attacks become possible. We compare currency boards, fixed rate and flexible rates, with and without a lender of last resort. A currency...

  2. Fragility Analysis of Concrete Gravity Dams

    Science.gov (United States)

    Tekie, Paulos B.; Ellingwood, Bruce R.

    2002-09-01

    Concrete gravity dams are an important part ofthe nation's infrastructure. Many dams have been in service for over 50 years, during which time important advances in the methodologies for evaluation of natural phenomena hazards have caused the design-basis events to be revised upwards, in some cases significantly. Many existing dams fail to meet these revised safety criteria and structural rehabilitation to meet newly revised criteria may be costly and difficult. A probabilistic safety analysis (PSA) provides a rational safety assessment and decision-making tool managing the various sources of uncertainty that may impact dam performance. Fragility analysis, which depicts fl%e uncertainty in the safety margin above specified hazard levels, is a fundamental tool in a PSA. This study presents a methodology for developing fragilities of concrete gravity dams to assess their performance against hydrologic and seismic hazards. Models of varying degree of complexity and sophistication were considered and compared. The methodology is illustrated using the Bluestone Dam on the New River in West Virginia, which was designed in the late 1930's. The hydrologic fragilities showed that the Eluestone Dam is unlikely to become unstable at the revised probable maximum flood (PMF), but it is likely that there will be significant cracking at the heel ofthe dam. On the other hand, the seismic fragility analysis indicated that sliding is likely, if the dam were to be subjected to a maximum credible earthquake (MCE). Moreover, there will likely be tensile cracking at the neck of the dam at this level of seismic excitation. Probabilities of relatively severe limit states appear to be only marginally affected by extremely rare events (e.g. the PMF and MCE). Moreover, the risks posed by the extreme floods and earthquakes were not balanced for the Bluestone Dam, with seismic hazard posing a relatively higher risk.

  3. Equilibrium analysis, banking, contagion and financial fragility

    OpenAIRE

    Tsomocos, Dimitrios P.

    2003-01-01

    This paper contains a General Equilibrium model of an economy with Incomplete Markets (GEI) with money and default. The model is a simplified version of the real world consisting of a non-bank private sector, banks, a Central Bank, a government and a regulator. The model is used to analyse actions by policy makers and to identify policy relevant empirical work. Key analytical results are: A financially fragile system need not collapse; efficiency can be improved with policy intervention; and ...

  4. Multipartnered Fertility and Depression among Fragile Families

    OpenAIRE

    Turney, Kristin; Carlson, Marcia J.

    2011-01-01

    We used data from the Fragile Families and Child Wellbeing Study to examine the association between multipartnered fertility (MPF)—when parents have children with more than one partner—and depression. Random effects models suggested that MPF is associated with a greater likelihood of depression, net of family structure and other covariates. However, these associations disappeared in more conservative fixed effects models that estimated changes in MPF as a function of changes in depression. Re...

  5. Seismic fragility evaluation of unreinforced masonry walls

    International Nuclear Information System (INIS)

    A practical analysis scheme to evaluate the seismic fragility of unreinforced masonry walls which are used at various places in older reactor facilities is presented. Among the several failure modes for such walls, the out-of-plane bending failure is considered to be a major risk contributor in seismic PRA studies. In order to evaluate this failure mode, the use of an equivalent linear approximation method is examined based on comparisons with available test data and nonlinear time history analyses. (author)

  6. The highly fragile glass former Decalin

    International Nuclear Information System (INIS)

    Systems exhibiting the glass transition can be classified by fragility. In this work we studied structural and dynamical aspects of highly fragile C10 H18 Decalin. Trans Decalin is locked into a pseudo-flat centrosymmetric conformation, while cis Decalin interchanges dynamically between chiral, pseudo-spherical ground states. On investigation of the phase behaviour trans Decalin was found to crystallise rapidly and cleanly; its crystal structure could be determined. From the crystal structure the dynamics of crystalline trans Decalin could be calculated using ab-initio lattice energy calculations and compared to measurements. Using neutron diffraction and molecular dynamics simulations the amorphous structure of Decalin was investigated. The difference in structure to the common molecular liquid Cumene is significant. The features of the amorphous structure of sphere-like cis Decalin show strong resemblance to the ones of Argon and metallic glasses. The dynamics of Decalin were investigated in the slightly supercooled liquid range. Using neutron scattering and optical spectroscopy, data was collected for a wide spectral range and several temperatures. The data suggests high fragility for the generic Decalin mixture, which is in agreement with the reported results. By contrast to previous estimations, an extrapolation of our data indicates cis Decalin to be only slightly less fragile than the generic mixture. Finally a lower limit to the four point susceptibility function χ4 could be calculated and the number of correlated molecules determined. The evolution of this value as a function of Tg/T and relaxation time are in agreement with literature. (author)

  7. Correlated fragile site expression allows the identification of candidate fragile genes involved in immunity and associated with carcinogenesis

    Directory of Open Access Journals (Sweden)

    Puliti Alda

    2006-09-01

    Full Text Available Abstract Background Common fragile sites (cfs are specific regions in the human genome that are particularly prone to genomic instability under conditions of replicative stress. Several investigations support the view that common fragile sites play a role in carcinogenesis. We discuss a genome-wide approach based on graph theory and Gene Ontology vocabulary for the functional characterization of common fragile sites and for the identification of genes that contribute to tumour cell biology. Results Common fragile sites were assembled in a network based on a simple measure of correlation among common fragile site patterns of expression. By applying robust measurements to capture in quantitative terms the non triviality of the network, we identified several topological features clearly indicating departure from the Erdos-Renyi random graph model. The most important outcome was the presence of an unexpected large connected component far below the percolation threshold. Most of the best characterized common fragile sites belonged to this connected component. By filtering this connected component with Gene Ontology, statistically significant shared functional features were detected. Common fragile sites were found to be enriched for genes associated to the immune response and to mechanisms involved in tumour progression such as extracellular space remodeling and angiogenesis. Moreover we showed how the internal organization of the graph in communities and even in very simple subgraphs can be a starting point for the identification of new factors of instability at common fragile sites. Conclusion We developed a computational method addressing the fundamental issue of studying the functional content of common fragile sites. Our analysis integrated two different approaches. First, data on common fragile site expression were analyzed in a complex networks framework. Second, outcomes of the network statistical description served as sources for the

  8. Brief report: linkage between G6PD and fragile-X syndrome.

    Science.gov (United States)

    Filippi, G; Rinaldi, A; Archidiacono, N; Rocchi, M; Balazs, I; Siniscalco, M

    1983-05-01

    Eighteen Sardinian pedigrees segregating for the X-fragile site syndrome were studied with respect to the segregation of the fragile site (FS) at Xq28, mental retardation, and macro-orchidism. No exception was found in the association of this symptomatic triad (MOM-X) in 41 out of 42 patients examined. The exceptional individual had micro- rather than macro-orchidism and was found to have a 47, XXY sex chromosome complement. In six informative sibships, the MOM-X syndrome was found to segregate in close linkage association with G6PD-deficiency or protan colorblindness. The maximum likelihood estimate of recombination if 6% with 90% fiducial limits between 2.5 and 19.5% and an odds ratio in favor of measurable linkage of 428:1. However, no hint of measurable linkage was found in six pedigrees segregating for G6PD and the Renpenning syndrome or other unspecified types of X-linked mental retardation. These data give strong support to the generally held hypothesis that the FS at Zq28, characteristic of the MOM-X syndrome, is a direct expression of a genetic change in the same chromosomal region. They also clearly suggest that X-linked MR without FS may be the result of different allelic mutations at the same locus. PMID:6602550

  9. Diagnostic Yield of Chromosomal Microarray Analysis in an Autism Primary Care Practice: Which Guidelines to Implement?

    Science.gov (United States)

    McGrew, Susan G.; Peters, Brittany R.; Crittendon, Julie A.; Veenstra-VanderWeele, Jeremy

    2012-01-01

    Genetic testing is recommended for patients with ASD; however specific recommendations vary by specialty. American Academy of Pediatrics and American Academy of Neurology guidelines recommend G-banded karyotype and Fragile X DNA. The American College of Medical Genetics recommends Chromosomal Microarray Analysis (CMA). We determined the yield of…

  10. Comprehensive analysis of ultrasonic vocalizations in a mouse model of fragile X syndrome reveals limited, call type specific deficits.

    Directory of Open Access Journals (Sweden)

    Snigdha Roy

    Full Text Available Fragile X syndrome (FXS is a well-recognized form of inherited mental retardation, caused by a mutation in the fragile X mental retardation 1 (Fmr1 gene. The gene is located on the long arm of the X chromosome and encodes fragile X mental retardation protein (FMRP. Absence of FMRP in fragile X patients as well as in Fmr1 knockout (KO mice results, among other changes, in abnormal dendritic spine formation and altered synaptic plasticity in the neocortex and hippocampus. Clinical features of FXS include cognitive impairment, anxiety, abnormal social interaction, mental retardation, motor coordination and speech articulation deficits. Mouse pups generate ultrasonic vocalizations (USVs when isolated from their mothers. Whether those social ultrasonic vocalizations are deficient in mouse models of FXS is unknown. Here we compared isolation-induced USVs generated by pups of Fmr1-KO mice with those of their wild type (WT littermates. Though the total number of calls was not significantly different between genotypes, a detailed analysis of 10 different categories of calls revealed that loss of Fmr1 expression in mice causes limited and call-type specific deficits in ultrasonic vocalization: the carrier frequency of flat calls was higher, the percentage of downward calls was lower and that the frequency range of complex calls was wider in Fmr1-KO mice compared to their WT littermates.

  11. Mitotic chromosome structure

    International Nuclear Information System (INIS)

    Mounting evidence is compiling linking the physical organizational structure of chromosomes and the nuclear structure to biological function. At the base of the physical organizational structure of both is the concept of loop formation. This implies that physical proximity within chromosomes is provided for otherwise distal genomic regions and thus hierarchically organizing the chromosomes. Together with entropy many experimental observations can be explained with these two concepts. Among the observations that can be explained are the measured physical extent of the chromosomes, their shape, mechanical behavior, the segregation into territories (chromosomal and territories within chromosomes), the results from chromosome conformation capture experiments, as well as linking gene expression to structural organization.

  12. Determinants of Banking System Fragility : A Regional Perspective

    OpenAIRE

    Degryse, H.A.; Elahi, M.A.; Penas, M.F.

    2012-01-01

    Abstract: Banking systems are fragile not only within one country but also within and across regions. We study the role of regional banking system characteristics for regional banking system fragility. We find that regional banking system fragility reduces when banks in the region jointly hold more liquid assets, are better capitalized, and when regional banking systems are more competitive. For Asia and Latin-America, a greater presence of foreign banks also reduces regional banking fragilit...

  13. Can entrepreneurship boost sustainable development in fragile countries?

    OpenAIRE

    Pereira, Marta Manuel Amaral Marques

    2012-01-01

    Fragile countries pose an intricate challenge for governments and traditional aid approaches: they continue to struggle overtime with low resilience and vulnerability, and are now accounting for a growing share of the world’s poor. When every other method has failed, can entrepreneurship be the key ingredient for turnaround? For countries trapped in fragility, little has been researched or elaborated upon. We studied what current authors said about entrepreneurship and fragility, and which...

  14. Delay Eyeblink Classical Conditioning is Impaired in Fragile X Syndrome

    OpenAIRE

    Tobia, Michael J.; Woodruff-Pak, Diana S.

    2009-01-01

    We examined 400 ms delay eyeblink classical conditioning in 20 participants with Fragile X syndrome ages 17-77 years, and 20 age-matched, healthy control participants. The Fragile X group demonstrated impaired learning and abnormal conditioned response timing. Adults with Fragile X (n=16) were also tested at two successive 12-month follow-up sessions to examine reacquisition and long-term retention. Participants in groups older and younger than 45 years demonstrated significant learning durin...

  15. General Anesthesia and Fragile X Syndrome: Report of a Case

    OpenAIRE

    Casamassimo, Paul S.; Mcllvaine, William B.; Hagerman, Randi; Shellhart, Craig

    1985-01-01

    A case report of an 11-year-old Caucasian boy with the fragile X syndrome is presented. The fragile X syndrome is a form of X-linked mental retardation with a connective tissue component that involves mitral valve prolapse. Antibiotic prophylaxis, electrocardiographic abnormalities, and special anesthetic management considerations are elements of treating patients with fragile X syndrome. The patient received morphine sulfate and scopolamine as a preoperative premedication. Ketamine was also ...

  16. Autism and Fragile X: Is There a Neurochemical Link?

    OpenAIRE

    Meguid, Nagwa A.; Atta, Hazem M.; Rashed, Laila A; Amr S. Gouda; Khalil, Rehab O.; Hashish, Adel F.

    2014-01-01

    BACKGROUND:Autism and Fragile X syndrome are intertwined. This study aimed at assessing Serotonin, Glutamate, and Gama Amino Butyric Acid (GABA) in autism and Fragile X syndrome patients and to detect possible neurochemical similarities between the 2 disorders that can be used as metabolic biomarkers. DESIGN AND METHODS: Eighty subjects divided into four groups, two diseased groups (20 male patients with Autism and 20 males with Fragile X syndrome) and two control groups (20 neurotypical m...

  17. Institutions, Trade, and Social Cohesion in Fragile States

    OpenAIRE

    Mina Baliamoune-Lutz

    2008-01-01

    This paper examines the contribution of institutions, social cohesion, and trade to development (per-capita income) with an emphasis on fragile states in Africa. Results from Arellano-Bond GMM estimations suggest that political institutions, openness to trade, and social cohesion affect growth in fragile states via direct and indirect mechanisms. The results indicate that, beyond a certain level, openness to trade may actually be harmful to economic performance in fragile states, particularly...

  18. Chromosomal Abnormalities in ADHD

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2002-07-01

    Full Text Available The prevalence of fragile X syndrome, velocardiofacial syndrome (VCFS, and other cytogenetic abnormalities among 100 children (64 boys with combined type ADHD and normal intelligence was assessed at the NIMH and Georgetown University Medical Center.

  19. Seismic fragility evaluation of unreinforced masonry walls

    International Nuclear Information System (INIS)

    A practical analysis scheme to evaluate the seismic fragility of unreinforced masonry walls which are used to various places in older reactor facilities is presented. Among the several failure modes for such walls, the out-of-plane bending failure is considered to be a major risk contributor in seismic PRA studies. In order to evaluate this failure mode, the use of an equivalent linear approximation method is examined based on comparisons with available test data and nonlinear time history analyses. 6 refs., 4 figs., 3 tabs

  20. Chromosomal abnormalities in mentally retarded children in the Konya region--Turkey.

    Science.gov (United States)

    Cora, T; Demirel, S; Acar, A

    2000-01-01

    Etiology of mental retardation is diverse. 120 Students from 11 special training, education, and rehabilitation subclasses were investigated cytogenetically for determining the contribution of chromosomal abnormalities to mild mental retardation. 23 of the 120 children (19%) had chromosomal abnormalities: thirteen cases a classical trisomy 21 (the male:female ratio was 9:4), three a balanced autosomal reciprocal translocation, one a pericentric inversion of chromosome 9, and six fragile-X syndrome (The male:female ratio was 5:1). PMID:10756429

  1. Fetal chromosome analysis: screening for chromosome disease?

    DEFF Research Database (Denmark)

    Philip, J; Tabor, Ann; Bang, J;

    1983-01-01

    A + B). Pregnant women 35 years of age, women who previously had a chromosomally abnormal child, families with translocation carriers or other heritable chromosomal disease, families where the father was 50 years or more and women in families with a history of Down's syndrome (group A), were...... unbalanced chromosome abnormality in group A (women with elevated risk) is significantly higher than in group B + C (women without elevated risk) (relative risk 2.4). Women with a known familial translocation and women 40 years or more have a relative risk of 5.7 of having an unbalanced chromosome......The aim of the study was to investigate the rationale of the current indications for fetal chromosome analysis. 5372 women had 5423 amniocentesis performed, this group constituting a consecutive sample at the chromosome laboratory, Rigshospitalet, Copenhagen from March 1973 to September 1980 (Group...

  2. Fragile X syndrome in incestuous families

    Energy Technology Data Exchange (ETDEWEB)

    Seemanova, E. [Charles Univ., Prague (Czech Republic)

    1996-11-11

    Reed suggested the investigation of children 219 from incestuous unions as a method for calculation of the detrimental heterozygosity of man. Some studies of latent genetics load in man have been based on the comparison of health status of incestuous children with their half-sibs born to the same mothers in matings with nonconsanguineous partners. These studies were limited to the detection of autosomal-recessive genes leading to abnormal phenotypes or mental deficiency in homozygotes. The highest coefficient of inbreeding in human beings is 1/4 in offspring of incestuous matings: hence, the high proportion of affected homozygotes and low incidence of affected individuals among their maternal half-sibs. Mental deficiency in incestuous children represents not only cases of simple recessive inheritance. Recently, we observed three incestuous families in which fragile X syndrome was detected. The fra(X) children were born to carriers from incestuous unions as well as to unrelated partners. Therefore, we recommend use of incestuous children and their maternal half-sibs as a control group for studies estimating latent genetic load after investigation for fra(X). The incidence of fra(X) syndrome is high, and mental retardation in heterozygotes is uncommon. Both of these factors can play a role in the occurrence of incest, and in pregnancy at young age, as well as in multiple partnerships. Families of heterozygotes for fragile X should be excluded from the material for the calculation of human latent detrimental (autosomal-recessive) genetic load. 3 refs., 3 figs.

  3. Fragility Fractures in Patients with Psoriatic Arthritis.

    Science.gov (United States)

    Del Puente, Antonio; Esposito, Antonella; Costa, Luisa; Benigno, Carla; Del Puente, Aurora; Foglia, Francesca; Oriente, Alfonso; Bottiglieri, Paolo; Caso, Francesco; Scarpa, Raffaele

    2015-11-01

    Psoriatic arthritis (PsA) can have peculiar effects on bone, including mechanisms of bone loss such as erosions, but also of bone formation, such as ankylosis or periostitis. The aim of the present study was to describe the prevalence of fractures in patients with PsA as compared to healthy controls and to investigate determinants of fractures among cases. For both cases and controls, radiographs were read to identify vertebral fractures (VF), and the presence of femoral neck or other nonvertebral fractures was obtained from patients' medical history. The prevalence of fragility fractures on radiographic readings did not differ between cases and controls. The number of subjects showing a VF was 33 (36%) among PsA patients and 36 (36%) among controls, with a prevalence of severe VF of 8% among cases and 4% among controls. Controlling for covariates in a logistic model, the only variables showing a significant correlation with the presence of nonvertebral fractures (NVF) were disease duration (p=0.02), age (p=0.03), and bone mineral density at femoral neck (inverse correlation, p=0.04). Fractures should be carefully considered when evaluating the global picture of the patient with PsA for their contribution to the "fragility" profile. PMID:26523054

  4. Obtaining reliable quality data from fragility tests

    International Nuclear Information System (INIS)

    The parameters discussed in this paper are the same as those present in normal seismic qualification testing. These parameters behave differently in high level acceleration tests and their contribution in providing unreliable data is of major concern since there is a significant difference. These parameters need to be considered in developing methodology guidelines for future fragility standards. In seismic qualification testing, a predefined series of tests are performed and measured against a set of acceptance criteria. The response spectra generally has a peak acceleration of between 3-10 g's at a 2% damping value for the Design Basis Event (Safe Shutdown Earthquake). Fragility level testing has minimum starting point of 10 g's at 2% damping and is generally 20 g's at 2% damping. The dynamic characteristics of the simulated earthquake and the corresponding simulator hardware interfaces are the parameters discussed. There are two major parameter contributions in obtaining unreliable data. The first parameter is test specimen system hardware nonlinearities. The second major variable is electronic signal saturations

  5. Cytogenetic evaluation of chromosomal disorders in Down Syndrome

    International Nuclear Information System (INIS)

    Down Syndrome (DS) patients are at high risk to develop leukemia. They are also highly sensitive to the induction of chromosomal aberrations when their GO lymphocytes are irradiated in vitro. The objective of this study was to further investigate the differential radiosensitivity of DS lymphocytes at the different stages of the cell cycle, as damage to proliferating cells is more relevant to health problems than damage to non-dividing cells. In addition, the proliferation kinetics and stage of differentiation of circulating DS lymphocytes was studied in an attempt to understand the mechanism for the enhanced chromosomal radiosensitivity. Moreover, the x-ray induced specific chromosomal breakpoints were identified and correlated with the locations of oncogene and fragile sites in order to investigate cytogenetically the early stages of leukemogenesis

  6. Babies at Double Jeopardy: Medically Fragile Infants and Child Neglect

    Science.gov (United States)

    Fullar, Suzanne A.

    2008-01-01

    Medically fragile infants, those born prematurely or with other complex medical or genetic problems, are at risk of long-term health and developmental problems. When a medically fragile infant comes home to a family with significant social problems such as domestic violence, mental illness, or substance abuse, the infant is at double jeopardy--at…

  7. Finiteness Marking in Boys with Fragile X Syndrome

    Science.gov (United States)

    Sterling, Audra M.; Rice, Mabel L.; Warren, Steven F.

    2012-01-01

    Purpose: The current study investigated finiteness marking (e.g., he walk "s", he walk "ed") in boys with fragile X syndrome (FXS); the boys were grouped based on receptive vocabulary (i.e., borderline, impaired). Method: Twenty-one boys with the full mutation of fragile X, between the ages of 8 and 16 years participated. The boys completed probes…

  8. Attentional Set-Shifting in Fragile X Syndrome

    Science.gov (United States)

    Van der Molen, M. J. W.; Van der Molen, M. W.; Ridderinkhof, K. R.; Hamel, B. C. J.; Curfs, L. M. G.; Ramakers, G. J. A.

    2012-01-01

    The ability to flexibly adapt to the changing demands of the environment is often reported as a core deficit in fragile X syndrome (FXS). However, the cognitive processes that determine this attentional set-shifting deficit remain elusive. The present study investigated attentional set-shifting ability in fragile X syndrome males with the…

  9. Memory Skills of Boys with Fragile X Syndrome

    Science.gov (United States)

    Ornstein, Peter A.; Schaaf, Jennifer M.; Hooper, Stephen R.; Hatton, Deborah D.; Mirrett, Penny; Bailey, Donald B., Jr.

    2008-01-01

    Multiple aspects of memory were examined in 42 boys with fragile X syndrome and a comparison group of 42 typically developing boys matched on MA. Working memory, incidental memory, and deliberate memory were assessed with a battery that included both free-recall and recognition tasks. Findings indicated that boys with fragile X syndrome performed…

  10. Identification by molecular diagnosis of mosaic Turner's syndrome in an obligate carrier female for fragile X syndrome.

    OpenAIRE

    Tejada, M. I.; Mornet, E; Tizzano, E.; Molina, M.; Baiget, M; Boue, A

    1994-01-01

    A case of mosaic Turner's syndrome with a 45,X/46,XX/47,XXX karyotype, who was also a fragile X obligate carrier as the mother of an affected boy, was identified by molecular diagnosis. Complete haplotyping and direct DNA analysis showed that the X chromosome in all metaphases was the normal X. At the age of 57, she is mentally normal. Her external appearance was typical of Turner's syndrome. This report shows that molecular studies in conjunction with cytogenetic analysis can help in the cli...

  11. Mouse acute myeloid leukemia and abnormality in chromosome II

    International Nuclear Information System (INIS)

    This review described abnormality in chromosome II that is characteristic in the radiation-induced leukemia in the title (AML) in mice. The disease is reportedly increased in A-bomb survivors. AML occurs in mice of RFM, CBA and other strains 1-1.5 years after whole body irradiation. The incidence increases dependently on dose, however, it decreases over around the dose of 3 Gy of X- and γ-ray. The incidence (20-25%) is higher in males. Abnormality seen in chromosome II is classified in types I-IV and II-IV types involve terminal deletion, interstitial deletion and translocation. The deleted region common on the chromosome (marker chromosome) is about 1 cM long, which corresponds to human 11p11-12 region frequently deleted in AML patients. The AML marker chromosome is suggested to be yielded by genomic instability induced by radiation. It is also suggested that there are fragile sites in the chromosome II. Future investigations are conceivably to be concentrated for identification of the AML causing gene. (K.H.)

  12. Chromosome painting in plants.

    NARCIS (Netherlands)

    Schubert, I.; Fransz, P.F.; Fuchs, J.; Jong, de J.H.

    2001-01-01

    The current 'state-of-art' as to chromosome painting in plants is reviewed. We define different situations described as painting so far: i) Genomic in situ hybridisation (GISH) with total genomic DNA to distinguish alien chromosomes on the basis of divergent dispersed repeats, ii) 'Chromosomal in si

  13. Ectodermal dysplasia-skin fragility syndrome

    Directory of Open Access Journals (Sweden)

    Vijay S Adhe

    2011-01-01

    Full Text Available Ectodermal dysplasia-skin fragility (EDSF syndrome is a rare and first described inherited disorder of desmosomes. It occurs due to loss-of-function mutations in PKP1 gene resulting in poorly formed desmosomes and loss of desmosomal and epidermal integrity. We report a case of a 2-year-old Indian male child who presented with palmoplantar hyperkeratosis with fissuring, short, sparse, and easily pluckable scalp hair, nail dystrophy, and multiple erosions over the skin. Skin biopsy showed epidermal hyperplasia with widening of intercellular spaces. His developmental milestones were delayed but intelligence was normal. Echocardiography, X-ray chest, and electrocardiogram were normal. Very few cases of this syndrome have been reported in the literature. We consider this as the first case report from India.

  14. Pathological Plasticity in Fragile X Syndrome

    Directory of Open Access Journals (Sweden)

    Brandon S. Martin

    2012-01-01

    Full Text Available Deficits in neuronal plasticity are common hallmarks of many neurodevelopmental disorders. In the case of fragile-X syndrome (FXS, disruption in the function of a single gene, FMR1, results in a variety of neurological consequences directly related to problems with the development, maintenance, and capacity of plastic neuronal networks. In this paper, we discuss current research illustrating the mechanisms underlying plasticity deficits in FXS. These processes include synaptic, cell intrinsic, and homeostatic mechanisms both dependent on and independent of abnormal metabotropic glutamate receptor transmission. We place particular emphasis on how identified deficits may play a role in developmental critical periods to produce neuronal networks with permanently decreased capacity to dynamically respond to changes in activity central to learning, memory, and cognition in patients with FXS. Characterizing early developmental deficits in plasticity is fundamental to develop therapies that not only treat symptoms but also minimize the developmental pathology of the disease.

  15. Entanglement and decoherence: fragile and robust entanglement

    CERN Document Server

    Novotný, Jaroslav; Jex, Igor

    2011-01-01

    The destruction of entanglement of open quantum systems by decoherence is investigated in the asymptotic long-time limit. Starting from a general and analytically solvable decoherence model which does not involve any weak-coupling or Markovian assumption it is shown that two fundamentally different classes of entangled states can be distinguished. Quantum states of the first class are fragile against decoherence so that they can be disentangled asymptotically even if coherences between pointer states are still present. Quantum states of the second type are robust against decoherence. Asymptotically they can be disentangled only if also decoherence is perfect. A simple criterion for identifying these two classes on the basis of two-qubit entanglement is presented.

  16. Seismic fragility of nuclear power plant components (Phase II)

    International Nuclear Information System (INIS)

    As part of the Component Fragility Program which was initiated in FY 1985, three additional equipment classes have been evaluated. This report contains the fragility results and discussions on these equipment classes which are switchgear, I and C panels and relays. Both low and medium voltage switchgear assemblies have been considered and a separate fragility estimate for each type is provided. Test data on cabinets from the nuclear instrumentation/neutron monitoring system, plant/process protection system, solid state protective system and engineered safeguards test system comprise the BNL data base for I and C panels (NSSS). Fragility levels have been determined for various failure modes of switchgear and I ampersand C panels, and the deterministic results are presented in terms of test response spectra. In addition, the test data have been evaluated for estimating the respective probabilistic fragility levels which are expressed in terms of a median value, an uncertainty coefficient, a randomness coefficient and an HCLPF value. Due to a wide variation of relay design and the fragility level, a generic fragility level cannot be established for relays. 7 refs., 13 figs., 12 tabs

  17. Fragility and cooperativity concepts in hydrogen-bonded organic glasses

    Energy Technology Data Exchange (ETDEWEB)

    Delpouve, N., E-mail: delpouve.nicolas@gmail.com [AMME-LECAP EA 4528 International Laboratory, University of Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France); Vuillequez, A.; Saiter, A.; Youssef, B.; Saiter, J.M. [AMME-LECAP EA 4528 International Laboratory, University of Rouen, Avenue de l' Universite BP 12, 76801 Saint Etienne du Rouvray (France)

    2012-09-01

    Molecular dynamics at the glass transition of three lactose/oil glassy systems have been investigated according to the cooperativity and fragility approaches. From Donth's approach, the cooperativity length is estimated by modulated temperature calorimetric measurements. Results reveal that modification of the disaccharide by oil leads to increase the disorder degree in the lactose, the size of the cooperative domains and the fragility index. These particular hydrogen-bonded organic glasses follow the general tendency observed on organic and inorganic polymers: the higher the cooperativity length, the higher the value of the fragility index at T{sub g}.

  18. Fragility and cooperativity concepts in hydrogen-bonded organic glasses

    International Nuclear Information System (INIS)

    Molecular dynamics at the glass transition of three lactose/oil glassy systems have been investigated according to the cooperativity and fragility approaches. From Donth's approach, the cooperativity length is estimated by modulated temperature calorimetric measurements. Results reveal that modification of the disaccharide by oil leads to increase the disorder degree in the lactose, the size of the cooperative domains and the fragility index. These particular hydrogen-bonded organic glasses follow the general tendency observed on organic and inorganic polymers: the higher the cooperativity length, the higher the value of the fragility index at Tg.

  19. Seismic fragility analysis of structural components for HFBR facilities

    International Nuclear Information System (INIS)

    The paper presents a summary of recently completed seismic fragility analyses of the HFBR facilities. Based on a detailed review of past PRA studies, various refinements were made regarding the strength and ductility evaluation of structural components. Available laboratory test data were analysed to evaluate the formulations used to predict the ultimate strength and deformation capacities of steel, reinforced concrete and masonry structures. The biasness and uncertainties were evaluated within the framework of the fragility evaluation methods widely accepted in the nuclear industry. A few examples of fragility calculations are also included to illustrate the use of the presented formulations

  20. Modifying fragility and collective motion in polymer melts with nanoparticles.

    Science.gov (United States)

    Starr, Francis W; Douglas, Jack F

    2011-03-18

    We investigate the impact of nanoparticles (NP) on the fragility and cooperative stringlike motion in a model glass-forming polymer melt by molecular dynamics simulation. The NP cause significant changes to both the fragility and the average length of stringlike motion, where the effect depends on the NP-polymer interaction and NP concentration. We interpret these changes via the Adam-Gibbs (AG) theory, assuming the strings can be directly identified with the abstract "cooperatively rearranging regions" of AG. Our findings indicate that fragility is primarily a measure of the temperature dependence of the cooperativity of molecular motion. PMID:21469879

  1. Subsystem fragility: Seismic Safety Margins Research Program (Phase I)

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R. P.; Campbell, R. D.; Hardy, G.; Banon, H.

    1981-10-01

    Seismic fragility levels of safety related equipment are developed for use in a seismic oriented Probabilistic Risk Assessment (PRA) being conducted as part of the Seismic Safety Margins Research Program (SSMRP). The Zion Nuclear Power Plant is being utilized as a reference plant and fragility descriptions are developed for specific and generic safety related equipment groups in Zion. Both equipment fragilities and equipment responses are defined in probabilistic terms to be used as input to the SSMRP event tree/fault tree models of the Zion systems. 65 refs., 14 figs., 11 tabs.

  2. Invertible chaotic fragile watermarking for robust image authentication

    International Nuclear Information System (INIS)

    Fragile watermarking is a popular method for image authentication. In such schemes, a fragile signal that is sensitive to manipulations is embedded in the image, so that it becomes undetectable after any modification of the original work. Most algorithms focus either on the ability to retrieve the original work after watermark detection (invertibility) or on detecting which image parts have been altered (localization). Furthermore, the majority of fragile watermarking schemes suffer from robustness flaws. We propose a new technique that combines localization and invertibility. Moreover, watermark dependency on the original image and the non-linear watermark embedding procedure guarantees that no malicious attacks will manage to create information leaks.

  3. Chimpanzee chromosome 12 is homologous to human chromosome 2q

    Energy Technology Data Exchange (ETDEWEB)

    Sun, N. C.; Sun, C. R.Y.; Ho, T.

    1977-01-01

    Most of the 46 human chromosomes find their counterparts in the 48 chimpanzee chromosomes except for chromosome 2 which has been hypothesized to have been derived from a centric fusion of two chimpanzee acrocentric chromosomes. These two chromosomes correspond to the human chromosomes 2p and 2g. This conclusion is based primarily on chromosome banding techniques, and the somatic cell hybridization technique has also been used. (HLW)

  4. Financial Reforms and Financial Fragility: A Panel Data Analysis

    Directory of Open Access Journals (Sweden)

    Syed Faizan Iftikhar

    2015-04-01

    Full Text Available This paper explores the relationship between financial reforms, financial liberalization and the quality of banking regulation and supervision for financial fragility by applying a dynamic two-step system generalized method of moments GMM panel estimator technique. The finding of this study is that the financial vulnerability of the banking sector could be affected, not only by bank-specific and macro-specific variables; but also by financial liberalization and banking regulations and supervision policies. The empirical results of this study confirm the evidence that financial reforms and financial liberalization significantly enhance the likelihood of financial fragility while strong banking regulations and supervision have an inverse relationship with financial fragility. The results of this study also explain that the lag value of loan growth and unemployment contribute to enhancing financial fragility while equity to assets ratio, natural log of total assets and share of foreign banks reduce financial vulnerability.

  5. Establishing local government in fragile states: experimental evidence from Afghanistan

    NARCIS (Netherlands)

    T. Jochem; I. Murtazashvili; J. Murtazashvili

    2016-01-01

    International and domestic policy makers often promote elections to establish village government in fragile states. However, two additional options are available in such countries: formalization of self-governing village councils and formalization of community development councils (CDCs). We designe

  6. The displaced claiming their rights in fragile states

    OpenAIRE

    Antonia Mulvey

    2013-01-01

    To date, displaced persons in fragile and conflict-affected stateshave had little success in claiming their rights for housing, land andproperty violations. Creative legal thinking and strategic litigation has the potential to change this.

  7. Forests in Fragile and Conflict-Affected States

    OpenAIRE

    Harwell, Emily

    2011-01-01

    Recognizes in failed states or states at risk of becoming failed states the linkages between forests, armed conflict, poverty, and various aspects of state fragility. Forests are valuable for local subsistence livelihoods, timber, and other commercially valuable forest products, as well as ecosystem services including forest carbon and biodiversity. This makes the linkage between forests and fragile states significant to local poverty reduction, national and global trade, and global public go...

  8. Physical activity, bone density, and fragility fractures in women

    OpenAIRE

    Englund, Undis

    2009-01-01

    Scandinavia has among the highest incidence of fragility fractures in the world. The reasons for this are unknown, but might involve differences in genetic and/or environmental factors, such as sunlight exposure and levels of physical activity. Weight-bearing exercise is thought to have a beneficial effect on bone health in the young, but few studies have evaluated whether exercise in older subjects affects bone density and protects against fragility fractures. The initial objective of this t...

  9. On the importance of uncertain factors in seismic fragility assessment

    OpenAIRE

    Borgonovo, Emanuele; Zentner, Irmela; PELLEGRI A; Tarantola, Stefano; DE ROCQUIGNY E

    2012-01-01

    This paper addresses the definition of importance measures for helping the modeller to detect the factors on which to focus modelling activity and data collection in seismic fragility analysis. We study sensitivity measures consistent with the decision-support criteria of interest, namely, the (mean) fragility curve and the ‘‘High Confidence of Low Probability of Failure’’ (HCLPF) value. The importance measures are obtained analytically for the EPRI safety factor method, which is ...

  10. Osmotic fragility test in heterozygotes for alpha and beta thalassaemia.

    OpenAIRE

    Maccioni, L; Cao, A

    1985-01-01

    This study shows that the combination of heterozygous beta thalassaemia and deletion heterozygous (-alpha/alpha alpha) or homozygous (-alpha/-alpha) alpha+ thalassaemia may result in the production of erythrocytes which have normal mean volume and haemoglobinisation but decreased osmotic fragility. Based on this finding and previous studies, which have shown that beta thalassaemia screening by the osmotic fragility test may miss a significant proportion of beta thalassaemia heterozygotes, we ...

  11. Thyroid function in fragile-X syndrome males.

    OpenAIRE

    Bregman, J. D.; Leckman, J. F.; Ort, S. I.

    1990-01-01

    Twelve males with fragile-X syndrome between the ages of three and 28 years underwent assessment of thyroid function. All 12 subjects demonstrated normal baseline values for thyroid stimulating hormone (TSH), thyroxine, thyroid binding globulin (TBG), and estimated free thyroxine (EFT). Relative to a control group reported in the literature, however, the fragile-X subjects exhibited a blunted TSH response to thyrotropin releasing hormone (TRH). This finding suggests the presence of subtle dys...

  12. Fragile Countries and the 2008-2009 Crisis

    OpenAIRE

    Allen, Franklin; Giovannetti, Giorgia

    2010-01-01

    European Report on Development This paper analyses the channels through which the economic and financial crisis of 2008-2009 is transmitted to fragile countries in Sub-Saharan Africa. Trade stands out as the main direct channel, even though intra-Africa remittances play a relevant role, given that most migrants in Sub-Saharan Africa fragile countries cannot afford the cost of migrating to Europe or to the United States and stay close, remaining in the continent. Whether reduced...

  13. Aid to fragile states: Do donors help or hinder?

    OpenAIRE

    Browne, Stephen

    2007-01-01

    he record of aid to fragile and poorly-performing states is the real test of aid effectiveness. Rich countries can justify aid to fragile states both through altruism and self-interest. But, with some exceptions, donors have appeared at the wrong times and with the wrong attitudes, even sometimes undermining development progress. State failure has dimensions of both will and capacity. Failure demands constructive engagement by donors, in some cases to save people in weak states from their lea...

  14. Topic 3: Governance, Fragility, and Failure: Implications for Livelihoods

    OpenAIRE

    Ear, Sophal

    2008-01-01

    Sophal Ear, Ph.D. () http://faculty.nps.edu/sear Assistant Professor Department of National Security Affairs 27 October 2008 1. Common terms of reference 2. Defining “governance”, “fragility”, etc. 3. So what’s governance got to do with it? • Livelihoods • Policies, Institutions, and Processes • Good Governance Matters • Governance in Reality and in Practice 4. From Governance to FragilityFragility and Failed States: Europe in 164...

  15. Operationalizing Experience: Donor Approaches to Service Delivery in Fragile States

    OpenAIRE

    DiCaprio, Alisa

    2013-01-01

    This study explores the different approaches to service delivery in fragile states by surveying donors' own evaluations of their existing fragile states policies. Because there is limited understanding of what works in risky environments, monitoring and evaluation are critical components of effective assistance. By highlighting trends in the strategies that donors have developed to implement acknowledged good practices, we can better understand how these experiences might contribute to future...

  16. Seismic fragility of nuclear power plant components. Phase I

    International Nuclear Information System (INIS)

    As part of the Component Fragility Research Program, sponsored by the US Nuclear Regulatory Commission, BNL is involved in establishing seismic fragility levels for various nuclear power plant equipment by identifying, collecting and analyzing existing test data from various sources. In Phase I of this program, BNL has reviewed approximately seventy test reports to collect fragility or high level test data for switchgears, motor control centers and similar electrical cabinets, valve actuators and numerous electrical devices of various manufacturers and models. This report provides an assessment and evaluation of the data collected in Phase I. The fragility data for medium voltage and low voltage switchgears and motor control centers are analyzed using the test response spectra (TRS) as a measure of the fragility level. The analysis reveals that fragility levels can best be described by a group of TRS curves corresponding to various failure modes. The lower-bound curve indicates the initiation of malfunctioning or structural damage; whereas, the upper-bound curve corresponds to overall failure of the equipment based on known failure modes. High level test data for some components are included in the report. These data indicate that some components are inherently strong and do not exhibit any failure mode even when tested at the vibration limit of a shake table. The common failure modes are identified in the report. The fragility levels determined in this report have been compared with those used in the PRA and Seismic Margin Studies. It appears that the BNL data better correlate with the HCLPF (High Confidence of a Low Probability of Failure) level used in Seismic Margin Studies and can improve this level as high as 60% for certain applications. Specific recommendations are provided for proper application of BNL fragility data to other studies

  17. Distribution of X-ray-induced chromosome breakpoints in Down syndrome lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Shafik, H.M.; Au, W.W.; Whorton, E.B. Jr.; Legator, M.S. (Univ. of Texas Medical Branch, Galveston (USA))

    1990-01-01

    Down syndrome (DS) individuals are known to be predisposed to develop leukemia and their lymphocytes are highly sensitive to the induction of chromosome aberrations by X-rays. A study was conducted to identify the chromosome breakpoints and to evaluate whether site specificity for chromosome breakage and rearrangement may exist which may explain the predisposition phenomenon. DS lymphocytes at the G1 phase of the cell cycle were irradiated with 300, 450, and 600 rad of X-rays. Cells were harvested after 3 days in culture and 193 G-banded karyotypes were analyzed to identify the induced chromosome abnormalities. Out of 273 breakpoints identified, 122 were involved in the formation of stable chromosome rearrangements and 151 in the formation of unstable abnormalities. The Poisson analysis of these breakpoints demonstrated that 16 chromosome bands located in chromosomes 1, 3, 7, 12, 17, 19 and X were preferentially involved in breakage and rearrangement (P less than 0.05). These 16 bands are also found to be locations of cancer breakpoints, oncogenes, or fragile sites. Many abnormal cells were observed to carry stable chromosome rearrangements only. Therefore, these cells are presumed to be compatible with survival and to be initiated in the transformation process. We propose that similar stable and site-specific chromosome rearrangements may exist in proliferating cells in DS individuals after exposure to clastogens and that this abnormality predisposes them to develop leukemia.

  18. Distribution of X-ray-induced chromosome breakpoints in Down syndrome lymphocytes

    International Nuclear Information System (INIS)

    Down syndrome (DS) individuals are known to be predisposed to develop leukemia and their lymphocytes are highly sensitive to the induction of chromosome aberrations by X-rays. A study was conducted to identify the chromosome breakpoints and to evaluate whether site specificity for chromosome breakage and rearrangement may exist which may explain the predisposition phenomenon. DS lymphocytes at the G1 phase of the cell cycle were irradiated with 300, 450, and 600 rad of X-rays. Cells were harvested after 3 days in culture and 193 G-banded karyotypes were analyzed to identify the induced chromosome abnormalities. Out of 273 breakpoints identified, 122 were involved in the formation of stable chromosome rearrangements and 151 in the formation of unstable abnormalities. The Poisson analysis of these breakpoints demonstrated that 16 chromosome bands located in chromosomes 1, 3, 7, 12, 17, 19 and X were preferentially involved in breakage and rearrangement (P less than 0.05). These 16 bands are also found to be locations of cancer breakpoints, oncogenes, or fragile sites. Many abnormal cells were observed to carry stable chromosome rearrangements only. Therefore, these cells are presumed to be compatible with survival and to be initiated in the transformation process. We propose that similar stable and site-specific chromosome rearrangements may exist in proliferating cells in DS individuals after exposure to clastogens and that this abnormality predisposes them to develop leukemia

  19. Interim Stabilisation in Fragile Security Situations

    Directory of Open Access Journals (Sweden)

    Nat J. Colletta

    2012-09-01

    Full Text Available For more than two decades a conventional approach to security promotion has been widely applied by multilateral and bilateral agencies during war-to-peace transitions. Advocates of this approach typically recommend a combination of disarmament, demobilisation and reintegration (DDR and security sector reform (SSR to consolidate peace-making and peace-building processes (Colletta et al 2009, Muggah 2006. Notwithstanding the broad acceptance of such activities – and the theory that underlies them – there is little evidence that such interventions have contributed to any enduring solution to conflict and fragility (Muggah 2009. Indeed, analysts have come to recognise that the political, economic and social pre-conditions for DDR and SSR – including a relatively functional government, a reasonably stable labour market and a minimum level of social trust – are seldom in place. Even when these ambitious pre-requisites have been achieved, it is not clear that they are sufficient for DDR and SSR to take hold. Nevertheless, these orthodoxies persist in security promotion policy and practice.

  20. The Brazilian Pampa: A Fragile Biome

    Directory of Open Access Journals (Sweden)

    Valdir Marcos Stefenon

    2009-12-01

    Full Text Available Biodiversity is one of the most fundamental properties of Nature. It underpins the stability of ecosystems, provides vast bioresources for economic use, and has important cultural significance for many people. The Pampa biome, located in the southernmost state of Brazil, Rio Grande do Sul, illustrates the direct and indirect interdependence of humans and biodiversity. The Brazilian Pampa lies within the South Temperate Zone where grasslands scattered with shrubs and trees are the dominant vegetation. The soil, originating from sedimentary rocks, often has an extremely sandy texture that makes them fragile—highly prone to water and wind erosion. Human activities have converted or degraded many areas of this biome. In this review we discuss our state-of-the-art knowledge of the diversity and the major biological features of this regions and the cultural factors that have shaped it. Our aim is to contribute toward a better understanding of the current status of this special biome and to describe how the interaction between human activities and environment affects the region, highlighting the fragility of the Brazilian Pampa.

  1. Fragility curves of concrete bridges retrofitted by column jacketing

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Northridge earthquake inflicted various levels of damage upon a large number of Caltrans' bridges not retrofitted by column jacketing. In this respect, this study represents results of fragility curve development for two (2) sample bridges typical in southern California, strengthened for seismic retrofit by means of steel jacketing of bridge columns. Monte Carlo simulation is performed to study nonlinear dynamic responses of the bridges before and after column retrofit. Fragility curves in this study are represented by Iognormal distribution functions with two parameters and developed as a function of PGA. The sixty (60) ground acceleration time histories for the Los Angeles area developed for the Federal Emergency Management Agcncy (FEMA) SAC (SEAOC-ATC-CUREe) steel project are used for the dynamic analysis of the bridges.The improvement in the fiagility with steel jacketing is quantified by comparing fragility curves of the bridge before and after column retrofit. In this first attempt to formulate the problem of fragility enhancement, the quantification is made by comparing the median values of the fragility curves before and after the retrofit. Under the hypothesis that this quantification also applies to empirical fragility curves developed on the basis of Northridge earthquake damage, the enhanced version of the empirical curves is developed for the ensuing analysis to determine the enhancement of transportation network performance due to the retrofit.

  2. BANKING SYSTEM FRAGILITY: CASE OF THE REPUBLIC OF MOLDOVA

    Directory of Open Access Journals (Sweden)

    Dorina CLICHICI

    2014-04-01

    Full Text Available The paper studied the determinants of Moldovan banking system fragility. It underlines the existing researches into the empirical determinants of banking fragility. The analysis revealed that there are numerous channels through which weaknesses within the macroeconomic conditions and structural characteristics might increase banking system fragility. The main macroeconomic determinants which may have an impact on Moldovan banking system fragility are: excessive domestic liquidity, pro-cyclical character of the banking system, dependence on remittances, financial dollarization. There are also several banking characteristics which play a role for Moldovan banking system fragility: the undermined intermediation function, high level of bad loans, uncertainties in the ownership structure, low presence of foreign strategic investors. The paper employed a quantitative, a qualitative and a comparative analysis using the financial soundness and structural indicators of the Moldovan banking system in order to assess the impact of various determinants on Moldovan banking system fragility. The results reveal a high degree of capitalization and liquidity of Moldovan banking system, factors which contribute and maintain the general stability of the entire financial system.

  3. Identification and Investigation of Native Chromosomal Fragile Sites in the Avian Cell Line DT40

    DEFF Research Database (Denmark)

    Pentzold, Constanze

    method is not relying on cytogenetic analysis, instead using a FANCD2 ChIP-­‐seq high-­‐throughput approach. It enables the application of the method irrespective of the original tissue. FANCD2 enrichment sites were validated as bona fide CFSs in avian DT40 cells. To additionally elucidate genomic...

  4. Fragile X Mental Retardation Syndrome: Structure of the KH1-KH2 Domains of Fragile X Mental Retardation Protein

    Energy Technology Data Exchange (ETDEWEB)

    Valverde,R.; Poznyakova, I.; Kajander, T.; Venkatraman, J.; Regan, L.

    2007-01-01

    Fragile X syndrome is the most common form of inherited mental retardation in humans, with an estimated prevalence of about 1 in 4000 males. Although several observations indicate that the absence of functional Fragile X Mental Retardation Protein (FMRP) is the underlying basis of Fragile X syndrome, the structure and function of FMRP are currently unknown. Here, we present an X-ray crystal structure of the tandem KH domains of human FMRP, which reveals the relative orientation of the KH1 and KH2 domains and the location of residue Ile304, whose mutation to Asn is associated with a particularly severe incidence of Fragile X syndrome. We show that the Ile304Asn mutation both perturbs the structure and destabilizes the protein.

  5. Chromosome studies of males in an institution for the mentally handicapped.

    OpenAIRE

    English, C J; Davison, E V; Bhate, M S; L. Barrett

    1989-01-01

    Karyotypes were examined in 512 (91.9%) of 557 male patients in an institution for the mentally handicapped. A total of 110 (21.5%) had an abnormal karyotype: 65 (12.7%) with Down's syndrome, 30 (5.9%) with the fragile X syndrome, 13 (2.5%) with autosomal anomalies other than Down's syndrome (12 unbalanced, one balanced), and two (0.4%) with sex chromosome anomalies.

  6. Transcriptionally Active Regions Are the Preferred Targets for Chromosomal HPV Integration in Cervical Carcinogenesis

    OpenAIRE

    Christiansen, Irene Kraus; Sandve, Geir Kjetil; Schmitz, Martina; Dürst, Matthias; Hovig, Eivind

    2015-01-01

    Integration of human papillomavirus (HPV) into the host genome is regarded as a determining event in cervical carcinogenesis. However, the exact mechanism for integration, and the role of integration in stimulating cancer progression, is not fully characterized. Although integration sites are reported to appear randomly distributed over all chromosomes, fragile sites, translocation break points and transcriptionally active regions have all been suggested as being preferred sites for integrati...

  7. miR-155 drives telomere fragility in human breast cancer by targeting TRF1.

    Science.gov (United States)

    Dinami, Roberto; Ercolani, Cristiana; Petti, Eleonora; Piazza, Silvano; Ciani, Yari; Sestito, Rosanna; Sacconi, Andrea; Biagioni, Francesca; le Sage, Carlos; Agami, Reuven; Benetti, Roberta; Mottolese, Marcella; Schneider, Claudio; Blandino, Giovanni; Schoeftner, Stefan

    2014-08-01

    Telomeres consist of DNA tandem repeats that recruit the multiprotein complex shelterin to build a chromatin structure that protects chromosome ends. Although cancer formation is linked to alterations in telomere homeostasis, there is little understanding of how shelterin function is limited in cancer cells. Using a small-scale screening approach, we identified miR-155 as a key regulator in breast cancer cell expression of the shelterin component TERF1 (TRF1). miR-155 targeted a conserved sequence motif in the 3'UTR of TRF1, resulting in its translational repression. miR-155 was upregulated commonly in breast cancer specimens, as associated with reduced TRF1 protein expression, metastasis-free survival, and relapse-free survival in estrogen receptor-positive cases. Modulating miR-155 expression in cells altered TRF1 levels and TRF1 abundance at telomeres. Compromising TRF1 expression by elevating miR-155 increased telomere fragility and altered the structure of metaphase chromosomes. In contrast, reducing miR-155 levels improved telomere function and genomic stability. These results implied that miR-155 upregulation antagonizes telomere integrity in breast cancer cells, increasing genomic instability linked to poor clinical outcome in estrogen receptor-positive disease. Our work argued that miRNA-dependent regulation of shelterin function has a clinically significant impact on telomere function, suggesting the existence of "telo-miRNAs" that have an impact on cancer and aging. PMID:24876105

  8. Plant sex chromosome evolution.

    Science.gov (United States)

    Charlesworth, Deborah

    2013-01-01

    It is now well established that plants have an important place in studies of sex chromosome evolution because of the repeated independent evolution of separate sexes and sex chromosomes. There has been considerable recent progress in studying plant sex chromosomes. In this review, I focus on how these recent studies have helped clarify or answer several important questions about sex chromosome evolution, and I shall also try to clarify some common misconceptions. I also outline future work that will be needed to make further progress, including testing some important ideas by genetic, molecular, and developmental approaches. Systems with different ages can clearly help show the time course of events during changes from an ancestral co-sexual state (hermaphroditism or monoecy), and I will also explain how different questions can be studied in lineages whose dioecy or sex chromosomes evolved at different times in the past. PMID:23125359

  9. Study on model of seismic fragility analysis for nuclear power plant

    International Nuclear Information System (INIS)

    After the Fukushima nuclear accident, the impact evaluation of nuclear power plants resulted from external events is required in China, and the 12th Five-Year Plan for Nuclear Safety also demands that the probability safety assessment of external events shall be developed before 2015. The earthquake is one of the most important external events which are essentially evaluated, and the seismic fragility is a key element in seismic PSA, while the fragility model is the basis of seismic fragility analysis. In this paper, the concept of seismic fragility was introduced, the seismic fragility model recommended by NRC and EPRI was studied, and the fragility model was derived. Then, the application example of the fragility model was given, and the effects of fragility due to randomness and uncertainty were discussed. The results show that a wealth of knowledge and experience is useful for the fragility analysis, which would reduce the uncertainty and gain access to practice. (authors)

  10. Vibrio chromosomes share common history

    OpenAIRE

    Gevers Dirk; Chang Sarah; Chang LeeAnn; Kirkup Benjamin C; Polz Martin F

    2010-01-01

    Abstract Background While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation. Results Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II) were identified from 19 sequenced Vibrionales genomes ...

  11. Alternative Lengthening of Telomeres: Recurrent Cytogenetic Aberrations and Chromosome Stability under Extreme Telomere Dysfunction

    Directory of Open Access Journals (Sweden)

    Despoina Sakellariou

    2013-11-01

    Full Text Available Human tumors using the alternative lengthening of telomeres (ALT exert high rates of telomere dysfunction. Numerical chromosomal aberrations are very frequent, and structural rearrangements are widely scattered among the genome. This challenging context allows the study of telomere dysfunction-driven chromosomal instability in neoplasia (CIN in a massive scale. We used molecular cytogenetics to achieve detailed karyotyping in 10 human ALT neoplastic cell lines.We identified 518 clonal recombinant chromosomes affected by 649 structural rearrangements. While all human chromosomes were involved in random or clonal, terminal, or pericentromeric rearrangements and were capable to undergo telomere healing at broken ends, a differential recombinatorial propensity of specific genomic regions was noted.We show that ALT cells undergo epigenetic modifications rendering polycentric chromosomes functionally monocentric, and because of increased terminal recombinogenicity, they generate clonal recombinant chromosomes with interstitial telomeric repeats. Losses of chromosomes 13, X, and 22, gains of 2, 3, 5, and 20, and translocation/deletion events involving several common chromosomal fragile sites (CFSs were recurrent. Long-term reconstitution of telomerase activity in ALT cells reduced significantly the rates of random ongoing telomeric and pericentromeric CIN. However, the contribution of CFS in overall CIN remained unaffected, suggesting that in ALT cells whole-genome replication stress is not suppressed by telomerase activation. Our results provide novel insights into ALT-driven CIN, unveiling in parallel specific genomic sites that may harbor genes critical for ALT cancerous cell growth.

  12. Alternative lengthening of telomeres: recurrent cytogenetic aberrations and chromosome stability under extreme telomere dysfunction.

    Science.gov (United States)

    Sakellariou, Despoina; Chiourea, Maria; Raftopoulou, Christina; Gagos, Sarantis

    2013-11-01

    Human tumors using the alternative lengthening of telomeres (ALT) exert high rates of telomere dysfunction. Numerical chromosomal aberrations are very frequent, and structural rearrangements are widely scattered among the genome. This challenging context allows the study of telomere dysfunction-driven chromosomal instability in neoplasia (CIN) in a massive scale. We used molecular cytogenetics to achieve detailed karyotyping in 10 human ALT neoplastic cell lines. We identified 518 clonal recombinant chromosomes affected by 649 structural rearrangements. While all human chromosomes were involved in random or clonal, terminal, or pericentromeric rearrangements and were capable to undergo telomere healing at broken ends, a differential recombinatorial propensity of specific genomic regions was noted. We show that ALT cells undergo epigenetic modifications rendering polycentric chromosomes functionally monocentric, and because of increased terminal recombinogenicity, they generate clonal recombinant chromosomes with interstitial telomeric repeats. Losses of chromosomes 13, X, and 22, gains of 2, 3, 5, and 20, and translocation/deletion events involving several common chromosomal fragile sites (CFSs) were recurrent. Long-term reconstitution of telomerase activity in ALT cells reduced significantly the rates of random ongoing telomeric and pericentromeric CIN. However, the contribution of CFS in overall CIN remained unaffected, suggesting that in ALT cells whole-genome replication stress is not suppressed by telomerase activation. Our results provide novel insights into ALT-driven CIN, unveiling in parallel specific genomic sites that may harbor genes critical for ALT cancerous cell growth. PMID:24339742

  13. Fragility estimates of smart structures with sensor faults

    International Nuclear Information System (INIS)

    In this paper, the impact of sensor faults within smart structures is investigated using seismic fragility analysis techniques. Seismic fragility analysis is one of the methods used to evaluate the vulnerability of structural systems under a broad range of earthquake events. It would play an important role in estimating seismic losses and in the decision making process based on vibration control performance of the smart structures during seismic events. In this study, a three-story building employing a highly nonlinear hysteretic magnetorheological (MR) damper is analyzed to estimate the seismic fragility of the smart control system. Different levels of sensor damage scenarios for smart structures are considered to provide a better understanding of the expected fragility estimates due to the impact of sensor failures. Probabilistic demand models are constructed with a Bayesian updating approach while the seismic capacity of smart structures is estimated based on the approximate structural performance of semi-actively controlled structures. Peak ground acceleration (PGA) of ground motion is used as a measure of earthquake intensity. Then the fragility curves for the smart structures are developed and compared with those for the semi-active control systems with different levels of sensor damage scenarios. The responses of an uncontrolled structure are used as a baseline. It is shown from the simulations that the proposed methodology is effective in quantifying the impact of sensor faults within smart structures. (paper)

  14. Developing empirical collapse fragility functions for global building types

    Science.gov (United States)

    Jaiswal, K.; Wald, D.; D'Ayala, D.

    2011-01-01

    Building collapse is the dominant cause of casualties during earthquakes. In order to better predict human fatalities, the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) program requires collapse fragility functions for global building types. The collapse fragility is expressed as the probability of collapse at discrete levels of the input hazard defined in terms of macroseismic intensity. This article provides a simple procedure for quantifying collapse fragility using vulnerability criteria based on the European Macroseismic Scale (1998) for selected European building types. In addition, the collapse fragility functions are developed for global building types by fitting the beta distribution to the multiple experts’ estimates for the same building type (obtained from EERI’s World Housing Encyclopedia (WHE)-PAGER survey). Finally, using the collapse probability distributions at each shaking intensity level as a prior and field-based collapse-rate observations as likelihood, it is possible to update the collapse fragility functions for global building types using the Bayesian procedure.

  15. Aging in Fragile X Premutation Carriers.

    Science.gov (United States)

    Lozano, Reymundo; Saito, Naomi; Reed, Dallas; Eldeeb, Marwa; Schneider, Andrea; Hessl, David; Tassone, Flora; Beckett, Laurel; Hagerman, Randi

    2016-10-01

    It is now recognized that FMR1 premutation carriers (PC) are at risk to develop a range of neurological, psychiatric, and immune-mediated disorders during adulthood. There are conflicting findings regarding the incidence of hypertension, hypothyroidism, diabetes, and cancer in these patients that warrant further study. A retrospective controlled study was performed in a convenience sample of 248 controls (130 men, 118 women) and 397 FMR1 PC with and without fragile X-associated tremor ataxia syndrome (FXTAS) (176 men, 221 women); all participants were at least 45 years old (men: mean 62.4, SD 9.5; women: mean 62.8, SD 9.9; p = 0.63). Memory and cognitive assessments (Wechsler Adult Intelligence Scale (WAIS-III), Wechsler Memory Scale (WMS-III)) and molecular testing (CGG repeats and FMR1-mRNA levels) were performed. Additional data included body mass index (BMI), cholesterol levels, blood pressure, hemoglobin A1c (HbA1c) levels, and medical history. A higher percentage of PC subjects self-reported having a diagnosis of hypertension (50.0 vs. 35.0 %, p = 0.006) and thyroid problems (20.4 vs. 10.0 %, p = 0.012) than control subjects. When comparing controls versus PC with FXTAS, the association was higher for diabetes (p = 0.043); however, the effect was not significant after adjusting for demographic predictors. Blood pressure, blood glucose levels, HbA1c, and BMI values were not significantly different between the two groups. The PC with FXTAS group performed consistently lower in neuropsychological testing compared with the PC without FXTAS group, but the differences were very small for all but the WAIS full-scale IQ. Based on these findings, it appears that the risk for hypertension, thyroid problems, and diabetes may be more frequent in PC with FXTAS, which will require verification in future studies. PMID:27334385

  16. Touch and massage for medically fragile infants.

    Science.gov (United States)

    Livingston, Karen; Beider, Shay; Kant, Alexis J; Gallardo, Constance C; Joseph, Michael H; Gold, Jeffrey I

    2009-12-01

    of the infants receiving massage. Massage in a tertiary urban academic NICU continues to be an area of needed study. Future studies examining infant health outcomes, such as weight gain, decreased length of hospitalization and caregiver-infant bonding, would provide greater insight into the impact of massage for medically fragile infants. PMID:18955228

  17. Sequential cloning of chromosomes

    Energy Technology Data Exchange (ETDEWEB)

    Lacks, S.A.

    1991-12-31

    A method for sequential cloning of chromosomal DNA and chromosomal DNA cloned by this method are disclosed. The method includes the selection of a target organism having a segment of chromosomal DNA to be sequentially cloned. A first DNA segment, having a first restriction enzyme site on either side. homologous to the chromosomal DNA to be sequentially cloned is isolated. A first vector product is formed by ligating the homologous segment into a suitably designed vector. The first vector product is circularly integrated into the target organism`s chromosomal DNA. The resulting integrated chromosomal DNA segment includes the homologous DNA segment at either end of the integrated vector segment. The integrated chromosomal DNA is cleaved with a second restriction enzyme and ligated to form a vector-containing plasmid, which is replicated in a host organism. The replicated plasmid is then cleaved with the first restriction enzyme. Next, a DNA segment containing the vector and a segment of DNA homologous to a distal portion of the previously isolated DNA segment is isolated. This segment is then ligated to form a plasmid which is replicated within a suitable host. This plasmid is then circularly integrated into the target chromosomal DNA. The chromosomal DNA containing the circularly integrated vector is treated with a third, retrorestriction enzyme. The cleaved DNA is ligated to give a plasmid that is used to transform a host permissive for replication of its vector. The sequential cloning process continues by repeated cycles of circular integration and excision. The excision is carried out alternately with the second and third enzymes.

  18. A new chromosome was born: comparative chromosome painting in Boechera.

    Science.gov (United States)

    Koch, Marcus A

    2015-09-01

    Comparative chromosome painting is a powerful tool to study the evolution of chromosomes and genomes. Analyzing karyotype evolution in cruciferous plants highlights the origin of aberrant chromosomes in apomictic Boechera and further establishes the cruciferous plants as important model system for our understanding of plant chromosome and genome evolution. PMID:26228436

  19. Fabrication and transfer of fragile 3D PDMS microstructures

    International Nuclear Information System (INIS)

    We present a method for PDMS microfabrication of fragile membranes and 3D fluidic networks, using a surface modified water-dissolvable release material, poly(vinyl alcohol), as a tool for handling, transfer and release of fragile polymer microstructures. The method is well suited for the fabrication of complex multilayer microfluidic devices, here shown for a PDMS device with a thin gas permeable membrane and closely spaced holes for vertical interlayer connections fabricated in a single layer. To the authors’ knowledge, this constitutes the most advanced PDMS fabrication method for the combination of thin, fragile structures and 3D fluidics networks, and hence a considerable step in the direction of making PDMS fabrication of complex microfluidic devices a routine endeavour. (paper)

  20. The robust-yet-fragile nature of interdependent networks

    CERN Document Server

    Tan, Fei

    2014-01-01

    Interdependent networks have been shown to be extremely vulnerable based on the percolation model. Parshani et. al further indicated that the more inter-similar networks are, the more robust they are to random failure. Our understanding of how coupling patterns shape and impact the cascading failures of loads in interdependent networks is limited, but is essential for the design and optimization of the real-world interdependent networked systems. This question, however, is largely unexplored. In this paper, we address this question by investigating the robustness of interdependent ER random graphs and BA scale-free networks under both random failure and intentional attack. It is found that interdependent ER random graphs are robust-yet-fragile under both random failures and intentional attack. Interdependent BA scale-free networks, however, are only robust-yet-fragile under random failure but fragile under intentional attack. These results advance our understanding of the robustness of interdependent networks...

  1. Fabrication and transfer of fragile 3D PDMS microstructures

    Science.gov (United States)

    Mikael Karlsson, J.; Haraldsson, Tommy; Carlborg, Carl Fredrik; Hansson, Jonas; Russom, Aman; van der Wijngaart, Wouter

    2012-08-01

    We present a method for PDMS microfabrication of fragile membranes and 3D fluidic networks, using a surface modified water-dissolvable release material, poly(vinyl alcohol), as a tool for handling, transfer and release of fragile polymer microstructures. The method is well suited for the fabrication of complex multilayer microfluidic devices, here shown for a PDMS device with a thin gas permeable membrane and closely spaced holes for vertical interlayer connections fabricated in a single layer. To the authors’ knowledge, this constitutes the most advanced PDMS fabrication method for the combination of thin, fragile structures and 3D fluidics networks, and hence a considerable step in the direction of making PDMS fabrication of complex microfluidic devices a routine endeavour.

  2. Seismic fragilities for nuclear power plant risk studies

    International Nuclear Information System (INIS)

    Seismic fragilities of critical structures and equipment are developed as families of conditional failure frequency curves plotted against peak ground acceleration. The procedure is based on available data combined with judicious extrapolation of design information on plant structures and equipment. Representative values of fragility parameters for typical modern nuclear power plants are provided. Based on the fragility evaluation for about a dozen nuclear power plants, it is proposed that unnecessary conservatism existing in current seismic design practice could be removed by properly accounting for inelastic energy absorption capabilities of structures. The paper discusses the key contributors to seismic risk and the significance of possible correlation between component failures and potential design and construction errors. (orig.)

  3. Seismic fragilities for nuclear power plant risk studies

    International Nuclear Information System (INIS)

    Seismic fragilities of critical structures and equipment are developed as families of conditional failure frequency curves plotted against peak ground acceleration. The procedure is based on available data combined with judicious extrapolation of design information on plant structures and equipment. Representative values of fragility parameters for typical modern nuclear power plants are provided. Based on the fragility evaluation for about a dozen nuclear power plants, it is proposed that unnecessary conservatism existing in current seismic design practice could be removed by properly accounting for inelastic energy absorption capabilities of structures. The paper discusses the key contributors to seismic risk and the significance of possible correlation between component failures and potential design and construction errors

  4. A nonsense mutation in FMR1 causing fragile X syndrome

    DEFF Research Database (Denmark)

    Grønskov, Karen; Brøndum-Nielsen, Karen; Dedic, Alma;

    2011-01-01

    Fragile X syndrome is a common cause of inherited intellectual disability. It is caused by lack of the FMR1 gene product FMRP. The most frequent cause is the expansion of a CGG repeat located in the 5'UTR of FMR1. Alleles with 200 or more repeats become hypermethylated and transcriptionally silent....... Only few patients with intragenic point mutations in FMR1 have been reported and, currently, routine analysis of patients referred for fragile X syndrome includes solely analysis for repeat expansion and methylation status. We identified a substitution in exon 2 of FMR1, c.80C>A, causing a nonsense...... mutation p.Ser27X, in a patient with classical clinical symptoms of fragile X syndrome. The mother who carried the mutation in heterozygous form presented with mild intellectual impairment. We conclude that further studies including western blot and DNA sequence analysis of the FMR1 gene should be...

  5. Normal RNAi response in human fragile x fibroblasts

    DEFF Research Database (Denmark)

    Madsen, Charlotte; Grønskov, Karen; Brøndum-Nielsen, Karen;

    2009-01-01

    BACKGROUND: Fragile x syndrome is caused by loss of expression of the FMRP protein involved in the control of a large number of mRNA targets. The Drosophila ortholog dFXR interacts with a protein complex that includes Argonaute2, an essential component of the RNA-induced silencing complex (RISC......). Furthermore dFXR associates with Dicer, another essential processing enzyme of the RNAi pathway. Both microRNA and microRNA precursors can co-immunoprecipitate with dFXR. Consequently it has been suggested that the Fragile x syndrome may be due to a defect in an RNAi-related apparatus. FINDINGS: We have...... investigated the RNAi response in Fragile x patient cells lacking FMRP compared with normal controls. RNAi responses were successfully detected, but no statistically significant difference between the response in normal cells compared to patients cells was found - neither one nor two days after transfection...

  6. Whole-of-Government Approaches to Fragile States in Africa

    DEFF Research Database (Denmark)

    Olsen, Gorm Rye

    2013-01-01

    For a number of years fragile states have been high on the foreign policy agendas of the USA and the EU. Both actors look upon fragile states with great concern and consider them as security threats. Officially they give priority to ‘whole-of-government approaches’ (wga) when addressing the threats...... from these states. However, there is a gap between the policy declarations and the policies implemented by the two actors. The missing link in the implementation of wga in Africa is explained by two variables: on the one hand, material interests in the continent and, on the other hand, the institutions...

  7. Semi-Fragile Watermarking for Copyright Protection and Image Authentication

    Institute of Scientific and Technical Information of China (English)

    HUANG Ji-feng

    2005-01-01

    In this paper, we propose a semi-fragile watermarking technology for copyright protection and image authentication. We transform the image into wavelet domain and group the four adjacent wavelet coefficients. Utilizing the characteristics of the human visual system, we embed a digital signal into the average of the four adjacent wavelet coefficients since the mean has better stability than single wavelet coefficient. This method needn't original image when extracts the watermark. Experimental results show the effectiveness of this method which is robust to common image process and fragile to malicious attack.

  8. Fragile X syndrome. Molecular and clinical insights and treatment issues.

    OpenAIRE

    Hagerman, R.J.

    1997-01-01

    The fragile X syndrome is the most common inherited cause of mental retardation that is known. The prevalence of mental retardation from this syndrome ranges from 1 in 1,250 to 1 in 4,000 in the general population, although the prevalence of female carriers has been reported to be as high as 1 in 259. The discovery of the FMR1 gene mutation in 1991 has simplified diagnosis, enhanced our understanding of the spectrum of involvement in the fragile X syndrome, and stimulated research regarding t...

  9. Human pluripotent stem cell models of Fragile X syndrome.

    Science.gov (United States)

    Bhattacharyya, Anita; Zhao, Xinyu

    2016-06-01

    Fragile X syndrome (FXS) is the most common inherited cause of intellectual disability and autism. The causal mutation in FXS is a trinucleotide CGG repeat expansion in the FMR1 gene that leads to human specific epigenetic silencing and loss of Fragile X Mental Retardation Protein (FMRP) expression. Human pluripotent stem cells (PSCs), including human embryonic stem cells (ESCs) and particularly induced PSCs (iPSCs), offer a model system to reveal cellular and molecular events underlying human neuronal development and function in FXS. Human FXS PSCs have been established and have provided insight into the epigenetic silencing of the FMR1 gene as well as aspects of neuronal development. PMID:26640241

  10. FRAGILE COUNTRIES AND THE 2008-2009 CRISIS.

    OpenAIRE

    Franklin Allen and Giorgia Giovannetti

    2010-01-01

    This paper analyses the channels through which the economic and financial crisis of 2008-2009 is transmitted to fragile countries in Sub-Saharan Africa. Trade stands out as the main direct channel, even though intra-Africa remittances play a relevant role, given that most migrants in Sub-Saharan Africa fragile countries cannot afford the cost of mi-grating to Europe or to the United States and stay close, remaining in the continent. Whether reduced aid flows also act as a crisis transmission ...

  11. Robust and fragile Werner states in the collective dephasing

    OpenAIRE

    Li, Shang-Bin; Xu, Jing-Bo

    2005-01-01

    We investigate the concurrence and Bell violation of the standard Werner state or Werner-like states in the presence of collective dephasing. It is shown that the standard Werner state and certain kinds of Werner-like states are robust against the collective dephasing, and some kinds of Werner-like states is fragile and becomes completely disentangled in a finite-time. The threshold time of complete disentanglement of the fragile Werner-like states is given. The influence of external driving ...

  12. Chimpanzee chromosome 13 is homologous to human chromosome 2p

    Energy Technology Data Exchange (ETDEWEB)

    Sun, N. C.; Sun, C. R.Y.; Ho, T.

    1977-01-01

    Similarities between human and chimpanzee chromosomes are shown by chromosome banding techniques and somatic cell hybridization techniques. Cell hybrids were obtained from the chimpanzee lymphocyte LE-7, and the Chinese hamster mutant cell, Gal-2. Experiments showed that the ACPL, MDHs, and Gal-Act genes could be assigned to chimpanzee chromosome 13, and since these genes have been assigned to human chromosme 2p, it is suggested that chimpanzee chromosome 13 is homologous to human chromosome 2p. (HLW)

  13. Chromosome condensation and segmentation

    International Nuclear Information System (INIS)

    Some aspects of chromosome condensation in mammalians -humans especially- were studied by means of cytogenetic techniques of chromosome banding. Two further approaches were adopted: a study of normal condensation as early as prophase, and an analysis of chromosome segmentation induced by physical (temperature and γ-rays) or chemical agents (base analogues, antibiotics, ...) in order to show out the factors liable to affect condensation. Here 'segmentation' means an abnormal chromosome condensation appearing systematically and being reproducible. The study of normal condensation was made possible by the development of a technique based on cell synchronization by thymidine and giving prophasic and prometaphasic cells. Besides, the possibility of inducing R-banding segmentations on these cells by BrdU (5-bromodeoxyuridine) allowed a much finer analysis of karyotypes. Another technique was developed using 5-ACR (5-azacytidine), it allowed to induce a segmentation similar to the one obtained using BrdU and identify heterochromatic areas rich in G-C bases pairs

  14. Chromosomal abnormalities and autism

    Directory of Open Access Journals (Sweden)

    Farida El-Baz

    2016-01-01

    Conclusion: Chromosomal abnormalities were not detected in the studied autistic children, and so the relation between the genetics and autism still needs further work up with different study methods and techniques.

  15. Chromosome numbers in Bromeliaceae

    OpenAIRE

    2000-01-01

    The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. u...

  16. Genetics Home Reference: fragile X-associated tremor/ataxia syndrome

    Science.gov (United States)

    ... Home Health Conditions FXTAS fragile X-associated tremor/ataxia syndrome Enable Javascript to view the expand/collapse ... All Close All Description Fragile X-associated tremor/ataxia syndrome ( FXTAS ) is characterized by problems with movement ...

  17. Fragile X Syndrome: Keys to the Molecular Genetics of Synaptic Plasticity

    Science.gov (United States)

    Lombroso, Paul J.; Ogren, Marilee P.

    2008-01-01

    Fragile X syndrome, the most common form of inherited mental retardation is discussed. The relationship between specific impairments in synaptic plasticity and Fragile X syndrome is investigated as it strengthens synaptic contacts between neurons.

  18. Structure and management of tuberculosis control programs in fragile states-Afghanistan, DR Congo, Haiti, Somalia

    NARCIS (Netherlands)

    V. Mauch; D. Weil; A. Munim; F. Boillot; R. Coninx; S. Huseynova; C. Powell; A. Seita; H. Wembanyama; S. van den Hof

    2010-01-01

    Objectives: Health care delivery is particularly problematic in fragile states often connected with increased incidence of communicable diseases, among them tuberculosis. This article draws upon experiences in tuberculosis control in four fragile states from which four lessons learned were derived.

  19. Micromechanics of human mitotic chromosomes

    International Nuclear Information System (INIS)

    Eukaryote cells dramatically reorganize their long chromosomal DNAs to facilitate their physical segregation during mitosis. The internal organization of folded mitotic chromosomes remains a basic mystery of cell biology; its understanding would likely shed light on how chromosomes are separated from one another as well as into chromosome structure between cell divisions. We report biophysical experiments on single mitotic chromosomes from human cells, where we combine micromanipulation, nano-Newton-scale force measurement and biochemical treatments to study chromosome connectivity and topology. Results are in accord with previous experiments on amphibian chromosomes and support the 'chromatin network' model of mitotic chromosome structure. Prospects for studies of chromosome-organizing proteins using siRNA expression knockdowns, as well as for differential studies of chromosomes with and without mutations associated with genetic diseases, are also discussed

  20. Vibrio chromosomes share common history

    Directory of Open Access Journals (Sweden)

    Gevers Dirk

    2010-05-01

    Full Text Available Abstract Background While most gamma proteobacteria have a single circular chromosome, Vibrionales have two circular chromosomes. Horizontal gene transfer is common among Vibrios, and in light of this genetic mobility, it is an open question to what extent the two chromosomes themselves share a common history since their formation. Results Single copy genes from each chromosome (142 genes from chromosome I and 42 genes from chromosome II were identified from 19 sequenced Vibrionales genomes and their phylogenetic comparison suggests consistent phylogenies for each chromosome. Additionally, study of the gene organization and phylogeny of the respective origins of replication confirmed the shared history. Conclusions Thus, while elements within the chromosomes may have experienced significant genetic mobility, the backbones share a common history. This allows conclusions based on multilocus sequence analysis (MLSA for one chromosome to be applied equally to both chromosomes.

  1. The effect of methionine and 5-azacytidine on fragile X expression.

    OpenAIRE

    Abruzzo, M A; Mayer, M.; Jacobs, P A

    1985-01-01

    The cellular mechanism for the expression of the fragile site at Xq28 is unknown. We tested the effect of 5-azacytidine and methionine on fragile X expression in lymphocytes and lymphoblastoid cells in an attempt to determine if DNA methylation was involved. We were unable to demonstrate a consistent dosage effect of methionine on fragile X expression. While 5-azacytidine was found to inhibit the fragile X in both males and females, it did so only at relatively high concentrations. We conclud...

  2. Cholinergic Dysfunction in Fragile X Syndrome and Potential Intervention: A Preliminary 1H MRS Study

    OpenAIRE

    Kesler, Shelli R.; Lightbody, Amy A.; Reiss, Allan L.

    2009-01-01

    Males with fragile X syndrome are at risk for significant cognitive and behavioral deficits, particularly those involving executive prefrontal systems. Disruption of the cholinergic system secondary to fragile X mental retardation protein deficiency may contribute to the cognitive-behavioral impairments associated with fragile X. We measured choline in the dorsolateral prefrontal cortex of 9 males with fragile X syndrome and 9 age-matched typically developing controls using 1H magnetic resona...

  3. Heart Activity and Autistic Behavior in Infants and Toddlers with Fragile X Syndrome

    OpenAIRE

    Roberts, Jane E.; Tonnsen, Bridgette; Robinson, Ashley; Svetlana V Shinkareva

    2012-01-01

    The present study contrasted physiological arousal in infants and toddlers with fragile X syndrome to typically developing control participants and examined physiological predictors early in development to autism severity later in development in fragile X syndrome. Thirty-one males with fragile X syndrome (ages 8–40 months) and 25 age-matched control participants were included. The group with fragile X syndrome showed shorter interbeat intervals (IBIs), lower vagal tone (VT), and less modulat...

  4. Significance of fragile site examination in children with mental retardation%智力低下儿脆性位点检查的意义

    Institute of Scientific and Technical Information of China (English)

    慕明涛; 霍满鹏; 张静; 刘俊俊; 蒲力群

    2013-01-01

    Objective: To explore the significance of chromosomal technique for diagnosing the causes of mental retardation. Methods: Eighty - six children with mental retardation were selected, then routine preparation of chromosomal samples of lymphocytes in peripheral blood, G band, karyotyping under microscope, and research on chromosomal fragile site expression were performed; 30 normal children were selected as control group. Results: Among 86 children with mental retardation, 24 children were found with abnormal karyotypes, the detection rate was 27. 91%. The incidence rates of chromosomal fragile site in experimental group and control group were 25. 02% and 5. 27% , respectively, there was statistically significant difference between the two groups (P <0. 01) . Conclusion: Chromosomal abnormality is one of important causes of mental retardation, there is a certain correlation between mental retardation and chromosomal aberration, expression rate of fragile site.%目的:探讨应用染色体技术诊断智力低下病因的意义.方法:对86例智力低下儿应用常规外周血淋巴细胞染色体标本制备、G显带、镜下核型分析和染色体脆性位点表达研究,另选正常儿童30例为对照组.结果:86例受检者中检出异常核型24例,检出率为27.91%.实验组染色体脆性位点的发生率为25.02%,对照组为5.27%,两组相比差异有统计学意义(P<0.01).结论:染色体异常是导致智力低下发生的重要原因之一,智力低下与染色体畸变和脆性部位表达率有一定的相关性.

  5. Family Environment and Behavior Problems in Children, Adolescents, and Adults with Fragile X Syndrome

    Science.gov (United States)

    Greenberg, Jan S.; Seltzer, Marsha Mailick; Baker, Jason K.; Smith, Leann E.; Warren, Steven F.; Brady, Nancy; Hong, Jinkuk

    2012-01-01

    We examine how the family environment is associated with aspects of the Fragile X syndrome phenotype during childhood, adolescence, and adulthood. Mothers of children (n = 48), adolescents (n = 85), and adults (n = 34) with Fragile X syndrome participated in a multisite study. For children and adults with Fragile X syndrome, the presence of warmth…

  6. Heart Activity and Autistic Behavior in Infants and Toddlers with Fragile X Syndrome

    Science.gov (United States)

    Roberts, Jane E.; Tonnsen, Bridgette; Robinson, Ashley; Shinkareva, Svetlana V.

    2012-01-01

    The present study contrasted physiological arousal in infants and toddlers with fragile X syndrome to typically developing control participants and examined physiological predictors early in development to autism severity later in development in fragile X syndrome. Thirty-one males with fragile X syndrome (ages 8-40 months) and 25 age-matched…

  7. Side Effects of Minocycline Treatment in Patients with Fragile X Syndrome and Exploration of Outcome Measures

    Science.gov (United States)

    Utari, Agustini; Chonchaiya, Weerasak; Rivera, Susan M.; Schneider, Andrea; Hagerman, Randi J.; Faradz, Sultana M. H.; Ethell, Iryna M.; Nguyen, Danh V.

    2010-01-01

    Minocycline can rescue the dendritic spine and synaptic structural abnormalities in the fragile X knock-out mouse. This is a review and preliminary survey to document side effects and potential outcome measures for minocycline use in the treatment of individuals with fragile X syndrome. We surveyed 50 patients with fragile X syndrome who received…

  8. Obesity, Food Selectivity, and Physical Activity in Individuals with Fragile X Syndrome

    Science.gov (United States)

    Raspa, Melissa; Bailey, Donald B., Jr.; Bishop, Ellen; Holiday, David; Olmsted, Murrey

    2010-01-01

    National survey data from 884 families were used to examine the overall health of children and adults with fragile X syndrome. Results indicate the rate of obesity in adults with fragile X syndrome is similar to the general population (30%). Male children with fragile X syndrome, however, had higher rates of obesity (31%) when compared with…

  9. Between Development and Security: The European Union, Governance and Fragile States

    NARCIS (Netherlands)

    W. Hout (Wil)

    2009-01-01

    textabstractOver the past five to seven years, most international aid donors have started to pay attention to so-called ‘fragile states’. Generally, the interest in state fragility was spurred by security considerations in the wake of the terrorist attacks of ‘9/11’. Fragile states came to be seen a

  10. Chromosome breakage at sites of oncogenes in a population accidentally exposed to radioactive chemical pollution

    International Nuclear Information System (INIS)

    The purpose of the present study was to investigate the level of aberrations at fragile sites of chromosomes in peripheral blood lymphocytes of the population of an area polluted with radionuclides, following an accident at the Siberian Chemical Plant (SCP). We carried out the micro-nucleus test to screen people with radiation-related cytogenetic effects. Of the 1246 examined inhabitants of the settlement of Samus, 148 showed a significantly increased frequency of micro-nucleated erythrocytes and were selected for the chromosome analysis as a radiation-exposed group. Additional analysis was carried out on 40 patients with gastric cancer and atrophic gastritis with stage II-III epithelial dysplasia. Eighty six individuals from a non-polluted area were used as a control group. Chromosomal breaks and exchanges occurred preferentially in chromosomes 3 and 6 among radiation-exposed persons and patients. The regions 3p14-3p25 and 6p23 were damaged most often. There was a tendency towards preferential involvement at q21-q25 of chromosome 6 in patients with gastric cancer and atrophic gastritis. Specific damage at certain chromosome sites was observed in the radiation-exposed population as well as in patients with gastric cancer. Most often this damage were located near oncogene loci which could imply that chromosome damage induced by radiation is likely to be a predisposing factor to the expression of oncogenes and malignant transformation of cells in exposed individuals. (author)

  11. Seismic fragility of ventilation stack of nuclear power plant

    International Nuclear Information System (INIS)

    Fragility study of safety related elements is necessary step in seismic PSA of nuclear power plant (NPP). In present work fragility was analyzed after the example of the ventilation stack of NPP. Ventilation stack, considered in present work, is a separately erected construction with height of 100 m made of cast-in-place reinforced concrete. In accordance with IAEA terminology fragility of element is defined as conditional probability of its failure at given level of seismic loading. Failure of a ventilation stack was considered as development of the plastic hinge in some section of a shaft. Seismic ground acceleration a, which corresponds to failure, could be defined as limit seismic acceleration of ventilation stack [a]. Limit seismic acceleration [a] was considered as random value. Sources of its variation are connected with stochastic nature of factors determining it (properties of construction materials, soils etc.), and also with uncertainties of existing analytical techniques. Random value [a] was assumed to be distributed lognormally. Median m[a] and logarithmically standard deviation β of this distribution were defined by 'scaling method' developed by R.P. Kennedy et al. Using this values fragility curves were plotted for different levels of confidence probability. (author)

  12. Arousal Modulation in Females with Fragile X or Turner Syndrome

    Science.gov (United States)

    Roberts, Jane; Mazzocco, Michele M. M.; Murphy, Melissa M.; Hoehn-Saric, Rudolf

    2008-01-01

    The present study was carried out to examine physiological arousal modulation (heart activity and skin conductance), across baseline and cognitive tasks, in females with fragile X or Turner syndrome and a comparison group of females with neither syndrome. Relative to the comparison group, for whom a greater increase in skin conductance was…

  13. Seismic fragility capacity of equipment--horizontal shaft pump test

    International Nuclear Information System (INIS)

    The current seismic fragility capacity of horizontal shaft pump is 1.6 x 9.8 m/s2(1.6 g), which was decided from previous vibration tests and we believe that it must have sufficient margin. The purpose of fragility capacity test is to obtain realistic seismic fragility capacity of horizontal shaft pump by vibration tests. Reactor Building Closed Cooling Water (RCW) Pump was tested as a typical horizontal shaft pump, and then bearings and liner rings were tested as important parts to evaluate critical acceleration and dispersion. Regarding RCW pump test, no damage was found, though maximum input acceleration level was 6 x 9.8 m/s2 (6 g). Some kinds of bearings and liner rings were tested on the element test. Input load was based on seismic motion which was same with the RCW pump test, and maximum load was equivalent to over 20 times of design seismic acceleration. There was not significant damage that caused emergency stop of pump but degradation of surface roughness was found on some kinds of bearings. It would cause reduction of pump life, but such damage on bearings occurred under large seismic load condition that was equivalent to over 10 to 20 g force. Test results show that realistic fragility capacity of horizontal shaft pump would be at least four times as higher as current value which has been used for our seismic PSA. (authors)

  14. The quest for targeted therapy in fragile X syndrome

    NARCIS (Netherlands)

    S. Zeidler; R.K. Hukema (Renate); R. Willemsen (Rob)

    2015-01-01

    textabstractFragile X syndrome (FXS) is the most common, monogenetic cause of intellectual disability and autism-spectrum disorders. Although there is no effective therapy, greater understanding of disturbed neuronal pathways has introduced options for targeted therapy. But whereas many FXS phenotyp

  15. Clinical assessment tools identify functional deficits in fragility fracture patients

    Science.gov (United States)

    Ames, Tyler D; Wee, Corinne E; Le, Khoi M; Wang, Tiffany L; Bishop, Julie Y; Phieffer, Laura S; Quatman, Carmen E

    2016-01-01

    Purpose To identify inexpensive, noninvasive, portable, clinical assessment tools that can be used to assess functional performance measures that may put older patients at risk for falls such as balance, handgrip strength, and lumbopelvic control. Patients and methods Twenty fragility fracture patients and 21 healthy control subjects were evaluated using clinical assessment tools (Nintendo Wii Balance Board [WBB], a handheld dynamometer, and an application for the Apple iPod Touch, the Level Belt) that measure functional performance during activity of daily living tasks. The main outcome measurements were balance (WBB), handgrip strength (handheld dynamometer), and lumbopelvic control (iPod Touch Level Belt), which were compared between fragility fracture patients and healthy controls. Results Fragility fracture patients had lower scores on the vertical component of the WBB Torso Twist task (P=0.042) and greater medial–lateral lumbopelvic sway during a 40 m walk (P=0.026) when compared to healthy controls. Unexpectedly, the fracture patients had significantly higher scores on the left leg (P=0.020) and total components (P=0.010) of the WBB Single Leg Stand task as well as less faults during the left Single Leg Stand task (P=0.003). Conclusion The clinical assessment tools utilized in this study are relatively inexpensive and portable tools of performance measures capable of detecting differences in postural sway between fragility fracture patients and controls.

  16. Auditory Brainstem Responses in Young Males with Fragile X Syndrome

    Science.gov (United States)

    Roberts, Joanne; Hennon, Elizabeth A.; Anderson, Kathleen; Roush, Jackson; Gravel, Judith; Skinner, Martie; Misenheimer, Jan; Reitz, Patricia

    2005-01-01

    Fragile X syndrome (FXS) is the most common inherited cause of mental retardation resulting in developmental delays in males. Atypical outer ear morphology is characteristic of FXS and may serve as a marker for abnormal auditory function. Despite this abnormality, studies of the hearing of young males with FXS are generally lacking. A few studies…

  17. Rethinking Youth, Livelihoods, and Fragility in West Africa

    OpenAIRE

    Fortune, Francis; Ismail, Olawale; Stephen, Monica

    2015-01-01

    Africa’s population is young and growing at twice the pace of other continents. A youth bulge presents a series of development policy opportunities and challenges. In this context, simplistic linkages between the youth bulge, high unemployment, and fragility have gained traction and given rise to a youth policy agenda that targets urban male youth as the problem and emphasizes formal secto...

  18. Developmental Trajectories of Young Girls with Fragile X Syndrome

    Science.gov (United States)

    Hatton, Deborah D.; Wheeler, Anne; Sideris, John; Sullivan, Kelly; Reichardt, Alison; Roberts, Jane; Clark, Renee; Bailey, Donald B., Jr.

    2009-01-01

    To describe the early phenotype of girls with full mutation fragile X, we used 54 observations of 15 girls between the ages of 6 months and 9 years to examine developmental trajectories as measured by the Battelle Development Inventory. In this sample, autistic behavior was associated with poorer developmental outcomes, primarily due to…

  19. Phonological Awareness and Reading in Boys with Fragile X Syndrome

    Science.gov (United States)

    Adlof, Suzanne M.; Klusek, Jessica; Shinkareva, Svetlana V.; Robinson, Marissa L.; Roberts, Jane E.

    2015-01-01

    Background: Reading delays are well documented in children with fragile X syndrome (FXS), but few studies have examined linguistic precursors of reading in this population. This study examined the longitudinal development of phonological awareness and its relationship with basic reading in boys with FXS. Individual differences in genetic,…

  20. Seizures in Fragile X Syndrome: Characteristics and Comorbid Diagnoses

    Science.gov (United States)

    Berry-Kravis, Elizabeth; Raspa, Melissa; Loggin-Hester, Lisa; Bishop, Ellen; Holiday, David; Bailey, Donald B., Jr.

    2010-01-01

    A national survey of caregivers of individuals with fragile X syndrome addressed characteristics of epilepsy and co-occurring conditions. Of the 1,394 individuals (1,090 males and 304 females) with the full mutation, 14% of males and 6% of females reported seizures. Seizures were more often partial, began between ages 4 and 10 years, and were…

  1. Social Cognition in Adolescent Girls with Fragile X Syndrome

    Science.gov (United States)

    Turkstra, Lyn S.; Abbeduto, Leonard; Meulenbroek, Peter

    2014-01-01

    This study aimed to characterize social cognition, executive functions (EFs), and everyday social functioning in adolescent girls with fragile X syndrome, and identify relationships among these variables. Participants were 20 girls with FXS and 20 age-matched typically developing peers. Results showed significant between-groups differences in…

  2. Fragile X mental retardation protein and synaptic plasticity

    OpenAIRE

    Sidorov, Michael S.; Auerbach, Benjamin D.; Bear, Mark F.

    2013-01-01

    Loss of the translational repressor FMRP causes Fragile X syndrome. In healthy neurons, FMRP modulates the local translation of numerous synaptic proteins. Synthesis of these proteins is required for the maintenance and regulation of long-lasting changes in synaptic strength. In this role as a translational inhibitor, FMRP exerts profound effects on synaptic plasticity.

  3. Gender Differences in Repetitive Language in Fragile X Syndrome

    Science.gov (United States)

    Murphy, M. M.; Abbeduto, L.

    2007-01-01

    Background: Verbal perseveration (i.e. excessive self-repetition) is a characteristic of male individuals with fragile X syndrome; however, little is known about its occurrence among females or its underlying causes. This project examined the relationship between perseveration and (1) gender, (2) cognitive and linguistic ability, and (3) language…

  4. Reading and Phonological Skills in Boys with Fragile X Syndrome

    Science.gov (United States)

    Klusek, Jessica; Hunt, Anna W.; Mirrett, Penny L.; Hatton, Deborah D.; Hooper, Stephen R.; Roberts, Jane E.; Bailey, Donald B.

    2015-01-01

    Although reading skills are critical for the success of individuals with intellectual disabilities, literacy has received little attention in fragile X syndrome (FXS). This study examined the literacy profile of FXS. Boys with FXS (n = 51; mean age 10.2 years) and mental age-matched boys with typical development (n = 35) participated in…

  5. Social Approach and Emotion Recognition in Fragile X Syndrome

    Science.gov (United States)

    Williams, Tracey A.; Porter, Melanie A.; Langdon, Robyn

    2014-01-01

    Evidence is emerging that individuals with Fragile X syndrome (FXS) display emotion recognition deficits, which may contribute to their significant social difficulties. The current study investigated the emotion recognition abilities, and social approachability judgments, of FXS individuals when processing emotional stimuli. Relative to…

  6. Implicit Procedural Learning in Fragile X and Down Syndrome

    Science.gov (United States)

    Bussy, G.; Charrin, E.; Brun, A.; Curie, A.; des Portes, V.

    2011-01-01

    Background: Procedural learning refers to rule-based motor skill learning and storage. It involves the cerebellum, striatum and motor areas of the frontal lobe network. Fragile X syndrome, which has been linked with anatomical abnormalities within the striatum, may result in implicit procedural learning deficit. Methods: To address this issue, a…

  7. Fragile ′X′ syndrome. A case study.

    OpenAIRE

    Mittal S; Rawal Y

    1996-01-01

    Fragile ′X′ syndrome also known as the Martin-Bell syndrome or the marker ′X′ syndrome is an ′X′-linked disorder with connective tissue dysplasia and varying degree of mental retardation. A case of this syndrome with characteristic Martin-Bell phenotype is presented. Oral features as yet unmentioned are added.

  8. Parenting Young Children with and without Fragile X Syndrome

    Science.gov (United States)

    Sterling, Audra; Barnum, Leah; Skinner, Debra; Warren, Steven F.; Fleming, Kandace

    2012-01-01

    The purpose of this study was to examine maternal parenting styles across age-matched siblings using a within-family design, in which one child has Fragile X syndrome. Thirteen families participated; children were aged 16 to 71 months. Mothers completed several videotaped activities with each child separately as well as an interview. Mothers used…

  9. Obtaining reliable quality data from fragility seismic tests

    International Nuclear Information System (INIS)

    The parameters discussed in this paper are the same as those present in normal seismic qualification testing. These parameters behave differently in high level acceleration tests and their contribution in providing unreliable data is of major concern since there is a significant difference. These parameters need to be considered in developing methodology guidelines for future fragility standards

  10. Identity in Fragile States: Social cohesion and state building

    OpenAIRE

    Seth Kaplan

    2009-01-01

    Seth Kaplan describes how understanding the relationship between identities, institutions, social cohesion, and state legitimacy is vital to spurring economic and political development in fragile states. The international community needs to stop imposing inflexible formulas for development and to start helping weak countries build on their own people's capacities for good governance.

  11. What Are the Symptoms of Fragile X Syndrome?

    Science.gov (United States)

    ... body language. Girls usually do not have severe problems with speech or language. Some children with Fragile X begin talking later than typically developing children. Most will talk eventually, but a few might stay nonverbal throughout their lives. Sensory. Many children with ...

  12. Development of hazard-compatible building fragility and vulnerability models

    Science.gov (United States)

    Karaca, E.; Luco, N.

    2008-01-01

    We present a methodology for transforming the structural and non-structural fragility functions in HAZUS into a format that is compatible with conventional seismic hazard analysis information. The methodology makes use of the building capacity (or pushover) curves and related building parameters provided in HAZUS. Instead of the capacity spectrum method applied in HAZUS, building response is estimated by inelastic response history analysis of corresponding single-degree-of-freedom systems under a large number of earthquake records. Statistics of the building response are used with the damage state definitions from HAZUS to derive fragility models conditioned on spectral acceleration values. Using the developed fragility models for structural and nonstructural building components, with corresponding damage state loss ratios from HAZUS, we also derive building vulnerability models relating spectral acceleration to repair costs. Whereas in HAZUS the structural and nonstructural damage states are treated as if they are independent, our vulnerability models are derived assuming "complete" nonstructural damage whenever the structural damage state is complete. We show the effects of considering this dependence on the final vulnerability models. The use of spectral acceleration (at selected vibration periods) as the ground motion intensity parameter, coupled with the careful treatment of uncertainty, makes the new fragility and vulnerability models compatible with conventional seismic hazard curves and hence useful for extensions to probabilistic damage and loss assessment.

  13. Agricultural Fragility Estimates Subjected to Volcanic Ash Fall Hazards

    Science.gov (United States)

    Ham, H. J.; Lee, S.; Choi, S. H.; Yun, W. S.

    2015-12-01

    Agricultural Fragility Estimates Subjected to Volcanic Ash Fall Hazards Hee Jung Ham1, Seung-Hun Choi1, Woo-Seok Yun1, Sungsu Lee2 1Department of Architectural Engineering, Kangwon National University, Korea 2Division of Civil Engineering, Chungbuk National University, Korea ABSTRACT In this study, fragility functions are developed to estimate expected volcanic ash damages of the agricultural sector in Korea. The fragility functions are derived from two approaches: 1) empirical approach based on field observations of impacts to agriculture from the 2006 eruption of Merapi volcano in Indonesia and 2) the FOSM (first-order second-moment) analytical approach based on distribution and thickness of volcanic ash observed from the 1980 eruption of Mt. Saint Helens and agricultural facility specifications in Korea. Fragility function to each agricultural commodity class is presented by a cumulative distribution function of the generalized extreme value distribution. Different functions are developed to estimate production losses from outdoor and greenhouse farming. Seasonal climate influences vulnerability of each agricultural crop and is found to be a crucial component in determining fragility of agricultural commodities to an ash fall. In the study, the seasonality coefficient is established as a multiplier of fragility function to consider the seasonal vulnerability. Yields of the different agricultural commodities are obtained from Korean Statistical Information Service to create a baseline for future agricultural volcanic loss estimation. Numerically simulated examples of scenario ash fall events at Mt. Baekdu volcano are utilized to illustrate the application of the developed fragility functions. Acknowledgements This research was supported by a grant 'Development of Advanced Volcanic Disaster Response System considering Potential Volcanic Risk around Korea' [MPSS-NH-2015-81] from the Natural Hazard Mitigation Research Group, Ministry of Public Safety and Security of

  14. Extreme genetic fragility of the HIV-1 capsid.

    Science.gov (United States)

    Rihn, Suzannah J; Wilson, Sam J; Loman, Nick J; Alim, Mudathir; Bakker, Saskia E; Bhella, David; Gifford, Robert J; Rixon, Frazer J; Bieniasz, Paul D

    2013-01-01

    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pressure to diversify. Therefore, it would be particularly advantageous for CA to evolve genetic robustness. To measure the genetic robustness of HIV-1 CA, we generated a library of single amino acid substitution mutants, encompassing almost half the residues in CA. Strikingly, we found HIV-1 CA to be the most genetically fragile protein that has been analyzed using such an approach, with 70% of mutations yielding replication-defective viruses. Although CA participates in several steps in HIV-1 replication, analysis of conditionally (temperature sensitive) and constitutively non-viable mutants revealed that the biological basis for its genetic fragility was primarily the need to coordinate the accurate and efficient assembly of mature virions. All mutations that exist in naturally occurring HIV-1 subtype B populations at a frequency >3%, and were also present in the mutant library, had fitness levels that were >40% of WT. However, a substantial fraction of mutations with high fitness did not occur in natural populations, suggesting another form of selection pressure limiting variation in vivo. Additionally, known protective CTL epitopes occurred preferentially in domains of the HIV-1 CA that were even more genetically fragile than HIV-1 CA as a whole. The extreme genetic fragility of HIV-1 CA may be one reason why cell-mediated immune responses to Gag correlate with better prognosis in HIV-1 infection, and suggests that CA is a good target for therapy and vaccination strategies

  15. Clinical assessment tools identify functional deficits in fragility fracture patients

    Directory of Open Access Journals (Sweden)

    Ames TD

    2016-05-01

    Full Text Available Tyler D Ames,1 Corinne E Wee,1 Khoi M Le,1 Tiffany L Wang,1 Julie Y Bishop,2 Laura S Phieffer,2 Carmen E Quatman2 1The Ohio State University College of Medicine, 2Department of Orthopaedics, The Ohio State University Wexner Medical Center, Columbus, OH, USA Purpose: To identify inexpensive, noninvasive, portable, clinical assessment tools that can be used to assess functional performance measures that may put older patients at risk for falls such as balance, handgrip strength, and lumbopelvic control.Patients and methods: Twenty fragility fracture patients and 21 healthy control subjects were evaluated using clinical assessment tools (Nintendo Wii Balance Board [WBB], a handheld dynamometer, and an application for the Apple iPod Touch, the Level Belt that measure functional performance during activity of daily living tasks. The main outcome measurements were balance (WBB, handgrip strength (handheld dynamometer, and lumbopelvic control (iPod Touch Level Belt, which were compared between fragility fracture patients and healthy controls.Results: Fragility fracture patients had lower scores on the vertical component of the WBB Torso Twist task (P=0.042 and greater medial–lateral lumbopelvic sway during a 40 m walk (P=0.026 when compared to healthy controls. Unexpectedly, the fracture patients had significantly higher scores on the left leg (P=0.020 and total components (P=0.010 of the WBB Single Leg Stand task as well as less faults during the left Single Leg Stand task (P=0.003.Conclusion: The clinical assessment tools utilized in this study are relatively inexpensive and portable tools of performance measures capable of detecting differences in postural sway between fragility fracture patients and controls. Keywords: fall risk, geriatric fracture, Nintendo Wii Balance Board, Level Belt, fragility fracture

  16. Chromosome numbers in Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Cotias-de-Oliveira Ana Lúcia Pires

    2000-01-01

    Full Text Available The present study reports chromosome numbers of 17 species of Bromeliaceae, belonging to the genera Encholirium, Bromelia, Orthophytum, Hohenbergia, Billbergia, Neoglaziovia, Aechmea, Cryptanthus and Ananas. Most species present 2n = 50, however, Bromelia laciniosa, Orthophytum burle-marxii and O. maracasense are polyploids with 2n = 150, 2n = 100 and 2n = 150, respectively, while for Cryptanthus bahianus, 2n = 34 + 1-4B. B chromosomes were observed in Bromelia plumieri and Hohenbergia aff. utriculosa. The chromosome number of all species was determined for the first time, except for Billbergia chlorosticta and Cryptanthus bahianus. Our data supports the hypothesis of a basic number of x = 25 for the Bromeliaceae family and decreasing aneuploidy in the genus Cryptanthus.

  17. Those amazing dinoflagellate chromosomes

    Institute of Scientific and Technical Information of China (English)

    PETER J RIZZO

    2003-01-01

    Dinoflagellates are a very large and diverse group of eukaryotic algae that play a major role in aquatic food webs of both fresh water and marine habitats. Moreover, the toxic members of this group pose a health threat in the form of red tides. Finally, dinoflagellates are of great evolutionary importance,because of their taxonomic position, and their unusual chromosome structure and composition. While the cytoplasm of dinoflagellates is typically eukaryotic, the nucleus is unique when compared to the nucleus of other eukaryotes. More specifically, while the chromosomes of all other eukaryotes contain histones,dinoflagellate chromosomes lack histones completely. There are no known exceptions to this observation: all dinoflagellates lack histones, and all other eukaryotes contain histones. Nevertheless, dinoflagellates remain a relatively unstudied group of eukaryotes.

  18. Formation of radiation induced chromosome aberrations: involvement of telomeric sequences and telomerase

    International Nuclear Information System (INIS)

    As telomeres are crucial for chromosome integrity; we investigated the role played by telomeric sequences in the formation and in the transmission of radio-induced chromosome rearrangements in human cells. Starting from interstitial telomeric sequences (ITS) as putative region of breakage, we showed that the radiation sensitivity is not equally distributed along chromosomes and. is not affected by ITS. On the contrary, plasmid integration sites are prone to radio-induced breaks, suggesting a possible integration at sites already characterized by fragility. However plasmids do not preferentially insert at radio-induced breaks in human cells immortalized by telomerase. These cells showed remarkable karyotype stability even after irradiation, suggesting a role of telomerase in the genome maintenance despite functional telomeres. Finally, we showed that the presence of more breaks in a cell favors the repair, leading to an increase of transmissible rearrangements. (author)

  19. Formation of radiation induced chromosome aberrations: involvement of telomeric sequences and telomerase

    Energy Technology Data Exchange (ETDEWEB)

    Pirzio, L.

    2004-07-15

    As telomeres are crucial for chromosome integrity; we investigated the role played by telomeric sequences in the formation and in the transmission of radio-induced chromosome rearrangements in human cells. Starting from interstitial telomeric sequences (ITS) as putative region of breakage, we showed that the radiation sensitivity is not equally distributed along chromosomes and. is not affected by ITS. On the contrary, plasmid integration sites are prone to radio-induced breaks, suggesting a possible integration at sites already characterized by fragility. However plasmids do not preferentially insert at radio-induced breaks in human cells immortalized by telomerase. These cells showed remarkable karyotype stability even after irradiation, suggesting a role of telomerase in the genome maintenance despite functional telomeres. Finally, we showed that the presence of more breaks in a cell favors the repair, leading to an increase of transmissible rearrangements. (author)

  20. Chromosomal rearrangements in cattle and pigs revealed by chromosome microdissection and chromosome painting

    Directory of Open Access Journals (Sweden)

    Yerle Martine

    2003-11-01

    Full Text Available Abstract A pericentric inversion of chromosome 4 in a boar, as well as a case of (2q-;5p+ translocation mosaicism in a bull were analysed by chromosome painting using probes generated by conventional microdissection. For the porcine inversion, probes specific for p arms and q arms were produced and hybridised simultaneously on metaphases of a heterozygote carrier. In the case of the bovine translocation, two whole chromosome probes (chromosome 5, and derived chromosome 5 were elaborated and hybridised independently on chromosomal preparations of the bull who was a carrier of the mosaic translocation. The impossibility of differentiating chromosomes 2 and der(2 from other chromosomes of the metaphases did not allow the production of painting probes for these chromosomes. For all experiments, the quality of painting was comparable to that usually observed with probes obtained from flow-sorted chromosomes. The results obtained allowed confirmation of the interpretations proposed with G-banding karyotype analyses. In the bovine case, however, the reciprocity of the translocation could not be proven. The results presented in this paper show the usefulness of the microdissection technique for characterising chromosomal rearrangements in species for which commercial probes are not available. They also confirmed that the main limiting factor of the technique is the quality of the chromosomal preparations, which does not allow the identification of target chromosomes or chromosome fragments in all cases.

  1. Location of a High-Lysine Gene and the DDT-Resistance Gene on Barley Chromosome 7

    DEFF Research Database (Denmark)

    Jensen, J.

    1979-01-01

    mutants, nos 1508.18, and 19. Linkage studies with translocations locate the Lys3 locus in the centromere region ofchromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker locifi (fragile stem), s(short rachilla hairs), and r (smooth awn) show that the...... order of the five loci on chromosome 7 from the long to the short chromosome arm is Y, s,fi, lys3, ddt. The distance from locus I to locus ddt is about 100 centimorgans....

  2. Ring chromosome 13

    DEFF Research Database (Denmark)

    Brandt, C A; Hertz, Jens Michael; Petersen, M B; Vogel, F; Noer, H; Mikkelsen, M

    1992-01-01

    A stillborn male child with anencephaly and multiple malformations was found to have the karyotype 46,XY,r(13) (p11q21.1). The breakpoint at 13q21.1, determined by high resolution banding, is the most proximal breakpoint ever reported in patients with ring chromosome 13. In situ hybridisation with...

  3. The Y Chromosome

    Science.gov (United States)

    Offner, Susan

    2010-01-01

    The Y chromosome is of great interest to students and can be used to teach about many important biological concepts in addition to sex determination. This paper discusses mutation, recombination, mammalian sex determination, sex determination in general, and the evolution of sex determination in mammals. It includes a student activity that…

  4. Chromosomes, cancer and radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Samouhos, E.

    1983-08-01

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available.

  5. Chromosomes, cancer and radiosensitivity

    International Nuclear Information System (INIS)

    Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available

  6. Chromosome Morphology in Kniphofia.

    Directory of Open Access Journals (Sweden)

    J. M. J de Wet

    1960-12-01

    Full Text Available A number of species and varieties of the genus  Kniphofia (Liliaceae were studied cytologically. The somatic chromosome number is  2n = 12 in all the species. This is also true in  Notosceptrum natalense Baker.

  7. Telomere dysfunction and chromosome instability

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, John P., E-mail: jmurnane@radonc.ucsf.edu [Department of Radiation Oncology, University of California San Francisco, 2340 Sutter Street, San Francisco, CA 94143-1331 (United States)

    2012-02-01

    The ends of chromosomes are composed of a short repeat sequence and associated proteins that together form a cap, called a telomere, that keeps the ends from appearing as double-strand breaks (DSBs) and prevents chromosome fusion. The loss of telomeric repeat sequences or deficiencies in telomeric proteins can result in chromosome fusion and lead to chromosome instability. The similarity between chromosome rearrangements resulting from telomere loss and those found in cancer cells implicates telomere loss as an important mechanism for the chromosome instability contributing to human cancer. Telomere loss in cancer cells can occur through gradual shortening due to insufficient telomerase, the protein that maintains telomeres. However, cancer cells often have a high rate of spontaneous telomere loss despite the expression of telomerase, which has been proposed to result from a combination of oncogene-mediated replication stress and a deficiency in DSB repair in telomeric regions. Chromosome fusion in mammalian cells primarily involves nonhomologous end joining (NHEJ), which is the major form of DSB repair. Chromosome fusion initiates chromosome instability involving breakage-fusion-bridge (B/F/B) cycles, in which dicentric chromosomes form bridges and break as the cell attempts to divide, repeating the process in subsequent cell cycles. Fusion between sister chromatids results in large inverted repeats on the end of the chromosome, which amplify further following additional B/F/B cycles. B/F/B cycles continue until the chromosome acquires a new telomere, most often by translocation of the end of another chromosome. The instability is not confined to a chromosome that loses its telomere, because the instability is transferred to the chromosome donating a translocation. Moreover, the amplified regions are unstable and form extrachromosomal DNA that can reintegrate at new locations. Knowledge concerning the factors promoting telomere loss and its consequences is

  8. Organization of the bacterial chromosome.

    OpenAIRE

    Krawiec, S.; Riley, M

    1990-01-01

    Recent progress in studies on the bacterial chromosome is summarized. Although the greatest amount of information comes from studies on Escherichia coli, reports on studies of many other bacteria are also included. A compilation of the sizes of chromosomal DNAs as determined by pulsed-field electrophoresis is given, as well as a discussion of factors that affect gene dosage, including redundancy of chromosomes on the one hand and inactivation of chromosomes on the other hand. The distinction ...

  9. Fragility: The Next Wave in Critical Infrastructure Protection

    Directory of Open Access Journals (Sweden)

    Allan McDougall

    2009-01-01

    Full Text Available In North America today, we are about to embark on a significant effort to repair, or even upgrade, many aspects of our infrastructure. Many of these efforts are linked to economic recovery packages. Others are based on sheer need. The challenge for decision makers and planners involves ensuring that scarce economic resources are put to their best use. Understanding the concept of fragility plays a pivotal part in reaching that understanding.Fragility, like many other systems—particularly Information Technology (IT systems—works on the concept of subjects and objects. Subjects are those entities that seek to exploit the services (or capacity offered by the object. Objects, on the other hand, are those entities that deliver some good or service to the overall system. Of course, something may act as the object in one pairing and the subject in another pairing—they are not exclusive in nature.

  10. Fragility and structure of Al-Cu alloy melts

    Energy Technology Data Exchange (ETDEWEB)

    Lv Xiaoqian [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Bian Xiufang [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China)]. E-mail: xfbian@sdu.edu.cn; Mao Tan [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Li Zhenkuan [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Guo Jing [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China); Zhao Yan [Key Laboratory of Liquid Structure and Heredity of Material, Education Ministry of China, Shandong University, Jingshi Road 73, Jinan 250061 (China)

    2007-04-15

    The dynamic viscosity measurements are performed for Al-Cu alloy melts with different compositions using an oscillating-cup viscometer. The results show that the viscosities of Al-Cu alloy melts increase with the copper content increasing, and also have a correlation with the correlation radius of clusters, which is measured by the high-temperature X-ray diffractometer. It has also been found that the fragilities of superheated melts (M) of hypereutectic Al-Cu alloys increase with the copper content increasing. There exists a relationship between the fragility and the structure in Al-Cu alloy melts. The value of the M reflects the variation of activation energy for viscous flow.

  11. Parenting young children with and without Fragile X syndrome.

    Science.gov (United States)

    Sterling, Audra; Barnum, Leah; Skinner, Debra; Warren, Steven F; Fleming, Kandace

    2012-05-01

    The purpose of this study was to examine maternal parenting styles across age-matched siblings using a within-family design, in which one child has Fragile X syndrome. Thirteen families participated; children were aged 16 to 71 months. Mothers completed several videotaped activities with each child separately as well as an interview. Mothers used a consistent, responsive style with both children, using the same degree of positive affect and warmth. Differences included using more behavior management strategies with the child with Fragile X and a conversational style of interaction with the sibling. Differences in approaches suggest the mothers adapted to the developmental differences between the children. The interview data supported these findings; mothers were aware of the changes made to accommodate the developmental differences. PMID:22716262

  12. Molecular analysis of fragile X syndrome in Antalya Province

    OpenAIRE

    Bilgen T; Keser I; Mihci E; Haspolat S; Tacoy S; Luleci G

    2005-01-01

    Background: Detection of the (CGG)n repeats in the FMR1 gene that cause the fragile X syndrome (FXS), has become a milestone for phenotype-genotype correlation in FXS. Aims: To screen the FMR1 gene CGG repeats in index cases with FXS and their family members in the Antalya Province. Setting and design: This study was prospectively conducted between January 200and March 2005 in Department of Medical Biology and Genetics, Faculty of Medicine, Akdeniz University, Antalya. Materials and Method...

  13. Matrix Metalloproteinases and Minocycline: Therapeutic Avenues for Fragile X Syndrome

    OpenAIRE

    Siller, Saul S.; Kendal Broadie

    2012-01-01

    Fragile X syndrome (FXS) is the most common known genetic form of intellectual disability and autism spectrum disorders. FXS patients suffer a broad range of other neurological symptoms, including hyperactivity, disrupted circadian activity cycles, obsessive-compulsive behavior, and childhood seizures. The high incidence and devastating effects of this disease state make finding effective pharmacological treatments imperative. Recently, reports in both mouse and Drosophila FXS disease models ...

  14. The quest for targeted therapy in fragile X syndrome

    OpenAIRE

    Zeidler, S.; Hukema, Renate; Willemsen, Rob

    2015-01-01

    textabstractFragile X syndrome (FXS) is the most common, monogenetic cause of intellectual disability and autism-spectrum disorders. Although there is no effective therapy, greater understanding of disturbed neuronal pathways has introduced options for targeted therapy. But whereas many FXS phenotypes were improved in preclinical studies with drugs targeting these pathways in the FXS mouse model, attempts to translate these animal-model success stories into treatment of patients in clinical t...

  15. Extreme genetic fragility of the HIV-1 capsid

    OpenAIRE

    Rihn, S.J.; Wilson, S. J.; Loman, N. J.; Alim, M.; Bakker, S.E.; Bhella, D.; Gifford, R.J.; Rixon, F J; Bieniasz, P D

    2013-01-01

    Genetic robustness, or fragility, is defined as the ability, or lack thereof, of a biological entity to maintain function in the face of mutations. Viruses that replicate via RNA intermediates exhibit high mutation rates, and robustness should be particularly advantageous to them. The capsid (CA) domain of the HIV-1 Gag protein is under strong pressure to conserve functional roles in viral assembly, maturation, uncoating, and nuclear import. However, CA is also under strong immunological pres...

  16. Characterization of ultrasonic vocalizations of Fragile X mice.

    Science.gov (United States)

    Belagodu, Amogh P; Johnson, Aaron M; Galvez, Roberto

    2016-09-01

    Fragile X Syndrome (FXS) is the leading form of inherited intellectual disability. It is caused by the transcriptional silencing of FMR1, the gene which codes for the Fragile X Mental Retardation Protein (FMRP). Patients who have FXS exhibit numerous behavioral and cognitive impairments, such as attention-deficit/hyperactivity disorder, obsessive compulsive disorder, and autistic-like behaviors. In addition to these behavioral abnormalities, FXS patients have also been shown to exhibit various deficits in communication such as abnormal sentence structures, increased utterances, repetition of sounds and words, and reduced articulation. These deficits can dramatically hinder communication for FXS patients, exacerbating learning and cognition impairments while decreasing their quality of life. To examine the biological underpinnings of these communication abnormalities, studies have used a mouse model of the Fragile X Syndrome; however, these vocalization studies have resulted in inconsistent findings that often do not correlate with abnormalities observed in FXS patients. Interestingly, a detailed examination of frequency modulated vocalizations that are believed to be a better assessment of rodent communication has never been conducted. The following study used courtship separation to conduct a detailed examination of frequency modulated ultrasonic vocalizations (USV) in FXS mice. Our analyses of frequency modulated USVs demonstrated that adult FXS mice exhibited longer phrases and more motifs. Phrases are vocalizations consisting of multiple frequency modulated ultrasonic vocalizations, while motifs are repeated frequency modulated USV patterns. Fragile X mice had a higher proportion of "u" syllables in all USVs and phrases while their wildtype counterparts preferred isolated "h" syllables. Although the specific importance of these syllables towards communication deficits still needs to be evaluated, these findings in production of USVs are consistent with the

  17. Financial Reforms and Financial Fragility: A Panel Data Analysis

    OpenAIRE

    Syed Faizan Iftikhar

    2015-01-01

    This paper explores the relationship between financial reforms, financial liberalization and the quality of banking regulation and supervision for financial fragility by applying a dynamic two-step system generalized method of moments GMM panel estimator technique. The finding of this study is that the financial vulnerability of the banking sector could be affected, not only by bank-specific and macro-specific variables; but also by financial liberalization and banking regulations and supervi...

  18. Systematic review of pharmacological treatments in fragile X syndrome

    OpenAIRE

    Tejada Maria-Isabel; Ballesteros Javier; Rueda Jose-Ramon

    2009-01-01

    Abstract Background Fragile X syndrome (FXS) is considered the most common cause of inherited mental retardation. Affected people have mental impairment that can include Attention Deficit and/or Hyperactivity Disorder (ADHD), autism disorder, and speech and behavioural disorders. Several pharmacological interventions have been proposed to treat those impairments. Methods Systematic review of the literature and summary of the evidence from clinical controlled trials that compared at least one ...

  19. A Contribution to the Theory of Financial Fragility and Crisis

    OpenAIRE

    Bhaduri, Amit

    2010-01-01

    Three interrelated aspects typical of most financial crisis of domestic origin are brought together in a model in this paper. The first aspect is debt financed consumption boom supported by rising asset prices which ultimately leads to credit crunch and debt deflation as lenders lose confidence in borrowers. This is related to the second aspect tracing gradual evolution towards Ponzi finance. This is accompanied by fragility of the financial sector itself and its insolvency as an inevitable o...

  20. The State of Synapses in Fragile X Syndrome

    OpenAIRE

    Pfeiffer, Brad E.; Huber, Kimberly M.

    2009-01-01

    Fragile X Syndrome is the most common inherited form of mental retardation and a leading genetic cause of autism. There is increasing evidence in both FXS and other forms of autism that alterations in synapse number, structure and function are associated and contribute to these prevalent diseases. FXS is caused by loss of function of the Fmr1 gene which encodes the RNA binding protein, FMRP. Therefore, FXS is a tractable model to understand synaptic dysfunction in cognitive disorders. FMRP is...

  1. On the Effect of State fragility on Corruption

    OpenAIRE

    Asongu, Simplice

    2014-01-01

    The Kodila-Tedika & Bolito-Losembe (2014, ADR) finding on no evidence of causality flowing from State fragility to classical corruption or extreme corruption could have an important influence on academic and policy debates. Using updated data (1996-2010) from 53 African countries, we provide evidence of a positive (negative) nexus between political stability/no violence and corruption-control (corruption). As a policy implication, the finding of the underlying paper maybe more expositional th...

  2. Bone fragility in postmenopausa women: a preliminar study

    OpenAIRE

    Fonseca, E.M.M.; Pereira, Ana I.; Rocha, D.F.S.; Noronha, J.K.

    2012-01-01

    The aim of this work is to identify the prevalence of risks factors for bone fragility in postmenopausal women with hormonal replacement therapy (HRT) within two groups (with bone fracture history and without bone fracture history) and to evaluate the effect of modifiable risk factors on bone mineral density (BMD). The overall prevalence of osteoporosis in postmenopausal Portuguese women is high. A pattern identification of occurrences, in a group of patients submitted to this analysis, will ...

  3. Modeling Fragility in Rapidly Evolving Disaster Response Systems

    OpenAIRE

    Comfort, Louise K.; Ko, Kilkon; Zagorecki, Adam

    2003-01-01

    Assessing the changing dynamic between the demand that is placed upon a community by cumulative exposure to hazards and the capacity of the community to mitigate or respond to that risk represents a central problem in estimating the community's resilience to disaster. This paper presents an initial effort to simulate the dynamic between increasing demand and decreasing capacity in an actual disaster response system to determine the point at which the system fails, or the fragility of the syst...

  4. Decentralized Local Governance In Fragile States: Learning From Iraq

    OpenAIRE

    Brinkerhoff, Derick W.; Johnson, Ronald W.

    2009-01-01

    This article examines the role that local governance plays in creating an effective state and in building constructive state—society relations. Reconstruction efforts in fragile, post-conflict states have focused largely on central government, yet decentralized local authorities offer a number of positive features. Looking at the governance reconstruction experience in Iraq, the analysis explores the extent to which these positive features have characterized Iraqi sub-national government. The...

  5. The Importance of Migration to Small Fragile Economies

    OpenAIRE

    Luthria, Manjula

    2009-01-01

    Most small fragile states have their own unique circumstances that predispose them to social conflict or frequent economic disruptions. These disruptions end up imposing a large cost on regional neighbours and on the international community more broadly. Therefore the development community is in search of ways to reduce the risk of conflict but this search has proved elusive thus far. This paper explores the potential for migration to serve as a safety valve as well as a medium...

  6. On the route to shear jamming, are fragile states real?

    OpenAIRE

    Zhang, Ling; Zheng, Jie; Jie ZHANG

    2015-01-01

    Starting from an unjammed initial state, applying shear to a granular material of a fixed packing fraction below $\\phi_J$, i.e. the isotropic jamming density of frictionless spheres can produce shear jamming states, as have been discovered recently. In addition, it has also been discovered that the system will first experience a bulk fragile state before evolving into a shear jammed state. Due to the existence of friction between the system and the third dimension in the previous studies, it ...

  7. Measuring the business environment for entrepreneurship in fragile states

    OpenAIRE

    Guglielmetti, Chiara

    2010-01-01

    This paper aims towards better understanding the role of entrepreneurship in fragile states, which despite the practical interest and relevance has been somewhat disregarded in academic research. Given the necessity to support policy formulation with appropriate and relevant measurement of entrepreneurship and the business environment, the primary focus in this paper is to scrutinize existing international indicators, in particular the World Bank's Doing Business (DB) indicators and ask wheth...

  8. Parenting Young Children with and without Fragile X Syndrome

    OpenAIRE

    Sterling, Audra M.; Barnum, Leah; Skinner, Debra; Warren, Steven F.; Fleming, Kandace

    2012-01-01

    The purpose of this study was to examine maternal parenting styles across age-matched siblings using a within-family design, in which one child has Fragile X syndrome. Thirteen families participated; children were aged 16 to 71 months. Mothers completed several videotaped activities with each child separately as well as an interview. Mothers used a consistent, responsive style with both children, using the same degree of positive affect and warmth. Differences included using more behavior man...

  9. Determinants of state fragility and implications for aid allocation: An assessment based on the country indicators for foreign policy project

    OpenAIRE

    Carment, David; Prest, Stewart; Samy, Yiagadeesen

    2008-01-01

    This paper is derived from our ongoing research on fragile states funded by the Canadian International Development Agency (CIDA) to help policymakers and analysts make decisions on where and how to allocate aid, especially in fragile state environments. In order for development assistance to have a measurable and positive impact on fragile states, it is necessary to understand both how and why they become fragile. First, we reconceptualize the meaning of state fragility with equal attention g...

  10. Fragility Modeling of Aging Containment Metallic Pressure Boundaries

    International Nuclear Information System (INIS)

    The containment in a nuclear power plant (NPP) provides a barrier against the release of radioactivity in the event of an accident. Corrosion that has been observed in some steel containments and liners of reinforced concrete containments has raised questions about their ability to perform this function. The performance of corroded containments during events at or beyond the design basis is impacted by numerous sources of uncertainty. A fragility model of the containment provides a relatively simple depiction of the impact of uncertainties on structural performance and a basis for decision-making in the presence of uncertainty. Moreover, it is a necessary ingredient of any time-dependent structural reliability analysis. A nonlinear finite element analysis of containment response furnishes the necessary platform to perform numerical experiments to determine containment fragility. A statistically-based sampling plan minimizes the finite element computations required to develop the fragility curve. The -percentile (or other fractile) then gives a statistically based indication of the lower bound on containment capacity, and can be used as a screening tool to determine whether more refined further analysis or tests to support service life evaluations are warranted

  11. Screening and diagnosis for the fragile X syndrome among the mentally retarded: an epidemiological and psychological survey. Collaborative Fragile X Study Group

    NARCIS (Netherlands)

    B.B.A. de Vries (Bert); B.A. Oostra (Ben); M.F. Niermeijer (Martinus); A. Tibben (Arend); A.M.W. van den Ouweland (Ans); S. Mohkamsing; H.J. Duivenvoorden (Hugo); E. Mol; K. Gelsema; M. van Rijn; D.J.J. Halley (Dicky); L.A. Sandkuijl (Lodewijk)

    1997-01-01

    textabstractThe fragile X syndrome is an X-linked mental retardation disorder caused by an expanded CGG repeat in the first exon of the fragile X mental retardation (FMR1) gene. Its frequency, X-linked inheritance, and consequences for relatives all prompt for diagnosis

  12. Do Individuals with Fragile X Syndrome Show Developmental Stuttering or Not? Comment on "Speech Fluency in Fragile X Syndrome" by Van Borsel, Dor and Rondal

    Science.gov (United States)

    Howell, Peter

    2008-01-01

    Van Borsel, Dor, and Rondal (2007) examined the speech of seven boys and two young male adults with fragile X syndrome and considered whether their speech was comparable to that reported in the developmental stuttering literature. They listed five criteria which led them to conclude that the speech patterns of speakers with fragile X syndrome…

  13. [Chromosomal organization of the genomes of small-chromosome plants].

    Science.gov (United States)

    Muravenko, O V; Zelenin, A V

    2009-11-01

    An effective approach to study the chromosome organization in genomes of plants with small chromosomes and/or with low-informative C-banding patterns was developed in the course of investigation of the karyotypes of cotton plant, camomile, flax, and pea. To increase the resolving power of chromosome analysis, methods were worked out for revealing early replication patterns on chromosomes and for artificial impairment of mitotic chromosome condensation with the use of a DNA intercalator, 9-aminoacridine (9-AMA). To estimate polymorphism of the patterns of C-banding of small chromosomes on preparations obtained with the use of 9-AMA, it is necessary to choose a length interval that must not exceed three average sizes of metaphase chromosomes without the intercalator. The use of 9-AMA increases the resolution of differential C- and OR-banding and the precision of physical chromosome mapping by the FISH method. Of particular importance in studying small chromosomes is optimization of the computer-aided methods used to obtain and process chromosome images. The complex approach developed for analysis of the chromosome organization in plant genomes was used to study the karyotypes of 24 species of the genus Linum L. It permitted their chromosomes to be identified for the first time, and, in addition, B chromosomes were discovered and studied in the karyotypes of the species of the section Syllinum. By similarity of the karyotypes, the studied flax species were distributed in eight groups in agreement with the clusterization of these species according to the results of RAPD analysis performed in parallel. Systematic positions and phylogenetic relationships of the studied flax species were verified. Out results can serve as an important argument in favour of the proposal to develop a special program for sequencing the genome of cultivated flax (L. usitatissimum L.), which is a major representative of small-chromosome species. PMID:20058798

  14. Investigation and treatment of osteoporosis in patients with fragility fractures

    Science.gov (United States)

    Hajcsar, Ernest E.; Hawker, Gillian; Bogoch, Earl R.

    2000-01-01

    Background Many patients who have undiagnosed osteoporosis and a recent fragility fracture present to fracture clinics in Canadian hospitals, where the focus of management is on fracture care. The rate of diagnosis and treatment of osteoporosis in this patient group is unknown. Methods Patients who presented with fractures at sites consistent with fragility-type fractures were identified through a retrospective chart review of fracture clinic visits in 3 Ontario community hospitals in selected weeks in February and November 1996 and August and May 1997. These patients were contacted by mail and telephone follow-up to obtain consent to participate in a telephone interview. Patients were excluded if the index fracture had been traumatic, if they were younger than 18 years, or if they had medical conditions known to be associated with secondary bone loss. Eligible patients were questioned about their history of prior fractures, diagnosis of osteoporosis, and investigation and treatment of osteoporosis before or after the index fracture. Results Among 2694 fracture clinic visits, we identified 228 patients (8.4%) with fragility-type fractures. Of the 228, 128 (56.1%) were contacted and agreed to participate in an interview about 1 year from the date of the index fracture. Of the 128 patients, 108 (83 postmenopausal and 13 premenopausal women and 12 men) were confirmed as eligible. Of the 108, 43 had experienced 53 fractures in addition to the index fracture in the preceding 10 years, of which 71% were of the fragility type. At interview, only 20 (18.5%) (all postmenopausal women) of the 108 patients reported that they had received a diagnosis of osteoporosis. Of the 20, 90% and 45% respectively had been advised to take calcium and vitamin D supplements; 8 (40%) were receiving hormone replacement therapy (HRT), and 8 (40%) were taking bisphosphonates. Of the 88 patients who had not received a diagnosis of osteoporosis, 4 (4.5%) were receiving HRT, none was taking

  15. Chromosome 19 International Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Pericak-Vance, M.A. (Duke Univ., Durham, NC (United States). Medical Center); Ropers, H.H. (Univ. Hospital Nijmegen, (The Netherlands). Dept. of Human Genetics); Carrano, A.J. (Lawrence Livermore National Lab., CA (United States))

    1993-01-04

    The Second International Workshop on Human Chromosome 19 was hosted on January 25 and 26, 1992, by the Department of Human Genetics, University Hospital Nijmegen, The Netherlands, at the 'Meerdal Conference Center'. The workshop was supported by a grant from the European Community obtained through HUGO, the Dutch Research Organization (NWO) and the Muscular Dystrophy Association (MDA). Travel support for American participants was provided by the Department of Energy. The goals of this workshop were to produce genetic, physical and integrated maps of chromosome 19, to identify inconsistencies and gaps, and to discuss and exchange resources and techniques available for the completion of these maps. The second day of the meeting was largely devoted to region or disease specific efforts. In particular, the meeting served as a platform for assessing and discussing the recent progress made into the molecular elucidation of myotonic dystrophy.

  16. Differential effects of treatment with UV-light (365 nm) and 8-methoxypsoralen on chromosomes of healthy persons and psoriatic patients

    International Nuclear Information System (INIS)

    The effect of 8-methoxypsoralen (8-MOP, 5 x 10-5 M), near UV-light of 365 nm wavelength (UVA, 1.5 J/cm2) and the combination of both (PUVA treatment) were studied on lymphocytes in vitro taken from healthy persons and patients with psoriasis vulgaris and psoriasis arthritis (psoriasis arthropathica). Chromosomes isolated from cell nuclei were visualized by means of Giemsa staining technique and analyzed for induction of chromosomal defects, i.e. premature centromere division (PCD), major coiling (MC), and formation of gaps and fragile sites. Exposure of nonpsoriatic lymphocytes to 8-MOP, UVA or PUVA increased the rate of PCD or MC generation. In experiments with psoriatic lymphocytes a much weaker effect was found, with a moderate increase of PCD and MC after UVA or PUVA treatment in the case of psoriasis vulgaris, and of MC after UVA treatment of psoriasis arthritis. On the average the number of chromosomes per metaphase plate displaying PCD did not exceed 10. No indication was obtained for the preference of certain chromosome groups or the appearance of 'fragile sites'. Under all experimental conditions the number of chromosome gaps ranged in the order of their spontaneous induction. The findings suggest PCD and MC investigations as possible sensitive tools for diagnosing latent psoriasis and for refined analysis of psoriatic cells or chromosomes. (author)

  17. Fragility in the 14q21q translocation region

    OpenAIRE

    Stacy R. Denison; Multani, Asha S.; Sen Pathak; Ira F. Greenbaum

    2002-01-01

    Aphidicolin (APC)-induced chromosomal breakage was analyzed for women representing three generations of a single family and carrying a Robertsonian translocation rob(14q21q). Fluorescence in situ hybridization (FISH) analysis confirmed the dicentric constitution of the derived chromosome and indicated the absence of beta-satellite signal at the translocation region. Per-individual analysis of metaphases from APC-treated peripheral blood lymphocyte cultures identified significantly nonrandom c...

  18. Broad clinical involvement in a family affected by the fragile X premutation

    OpenAIRE

    Chonchaiya, W; Utari, A; Pereira, GM; F. Tassone; Hessl, D.; Hagerman, RJ

    2009-01-01

    The mutations in the FMR1 gene have been described as a family of disorders called fragile X-associated disorders including fragile X syndrome, fragile X-associated tremor/ataxia syndrome, primary ovarian insufficiency, and other problems associated with the premutation, such as hypothyroidism, hypertension, neuropathy, anxiety, depression, attention-deficit hyperactivity disorders, and autism spectrum disorders. The premutation is relatively common in the general population affecting 1 of 13...

  19. Family Environment and Behavior Problems in Children, Adolescents, and Adults with Fragile X Syndrome

    OpenAIRE

    Greenberg, Jan S.; Seltzer, Marsha Mailick; Baker, Jason K.; Smith, Leann E.; Warren, Steven F.; Brady, Nancy; Hong, Jinkuk

    2012-01-01

    We examine how the family environment is associated with aspects of the Fragile X syndrome phenotype during childhood, adolescence, and adulthood. Mothers of children (n = 48), adolescents (n = 85), and adults (n = 34) with Fragile X syndrome participated in a multisite study. For children and adults with Fragile X syndrome, the presence of warmth and positivity and the absence of criticism were associated with fewer behavior problems. Although a higher level of criticism was significantly as...

  20. Extending Minsky's classifications of fragility to government and the open economy

    OpenAIRE

    Wray , L. Randall

    2006-01-01

    Minsky's classification of fragility according to hedge, speculative, and Ponzi positions is well-known. He wrote about fragile positions of individual firms and of the economy as a whole, with the economy transitioning naturally from a robust financial structure (dominated by hedge units) to a fragile structure (dominated by speculative units). In most of Minsky's writing, he introduced government through its impact on the private sector with its spending and balance sheet operations as stab...

  1. DNA demethylation induced by 5-azacytidine does not affect fragile X expression.

    OpenAIRE

    Glover, T W; Coyle-Morris, J; Pearce-Birge, L; Berger, C; Gemmill, R M

    1986-01-01

    Experiments were performed to determine the role of DNA demethylation in fragile X expression. Fragile X positive lymphoblastoid cells were treated with 5-azacytidine and harvested for analysis of fragile X expression both directly following treatment and after a recovery period in the absence of the drug. The effectiveness of 5-azacytidine treatment in inducing DNA demethylation was concurrently monitored by analysis of methylation changes at random autosomal loci in isolated DNA from treate...

  2. Discrimination Learning and Attentional Set Formation in a Mouse Model of Fragile X

    OpenAIRE

    Casten, Kimberly S.; Gray, Annette C; Burwell, Rebecca D.

    2011-01-01

    Fragile X Syndrome is the most prevalent genetic cause of mental retardation. Selective deficits in executive function, including inhibitory control and attention, are core features of the disorder. In humans, Fragile X results from a trinucleotide repeat in the Fmr1 gene that renders it functionally silent and has been modeled in mice by targeted deletion of the Fmr1 gene. Fmr1 knockout (KO) mice recapitulate many features of Fragile X syndrome, but evidence for deficits in executive functio...

  3. Evaluation of Fragility of the Economic System in Poyang Lake Ecological Economic Zone

    OpenAIRE

    Cheng, Qiao-zhen; Chen, Xiao-ling; Zhu, Feng-feng; Zhu, Jing

    2012-01-01

    From two aspects, namely the sensitivity of regional economic system to internal and external interference, and its resilience, we establish the evaluation indicator system of fragility of the economic system in Poyang Lake Ecological Economic Zone, and evaluate the internal differences in fragility of the regional economic system, using set pair analysis method. The results show that there is a great difference in fragility of the economic system between different administrative units; the d...

  4. Uncoupling of the endocannabinoid signalling complex in a mouse model of fragile X syndrome

    OpenAIRE

    Jung, Kwang-Mook; Sepers, Marja; Henstridge, Christopher M.; Lassalle, Olivier; Neuhofer, Daniela; Martin, Henry; Ginger, Melanie; Frick, Andreas; DiPatrizio, Nicholas V.; Mackie, Ken; Katona, Istvan; Piomelli, Daniele; Manzoni, Olivier J.

    2012-01-01

    Fragile X syndrome, the most commonly known genetic cause of autism, is due to loss of the fragile X mental retardation protein, which regulates signal transduction at metabotropic glutamate receptor-5 in the brain. Fragile X mental retardation protein deletion in mice enhances metabotropic glutamate receptor-5-dependent long-term depression in the hippocampus and cerebellum. Here we show that a distinct type of metabotropic glutamate receptor-5-dependent long-term depression at excitatory sy...

  5. Excess protein synthesis in Drosophila Fragile X mutants impairs long-term memory

    OpenAIRE

    Bolduc, François V.; Bell, Kimberly; Cox, Hilary; Broadie, Kendal; Tully, Tim

    2008-01-01

    We used Drosophila olfactory memory in order to understand in vivo the molecular basis of cognitive defect in Fragile X syndrome. We observed that Fragile X protein (FMRP) was required acutely and interacted with argonaute1 and staufen in long-term memory (LTM). Occlusion of long-term memory formation in Fragile X mutants could be rescued by protein synthesis inhibitors, suggesting that excess baseline protein synthesis could impact negatively on cognition.

  6. Strategy for reliable prenatal detection of normal male carriers of the fragile X syndrome

    OpenAIRE

    Halley, Dicky; Ouweland, Ans; Deelen, Wouter; Verma, Chandra; Oostra, Ben

    1994-01-01

    textabstractPrenatal diagnosis of fragile X syndrome identifying full mutations has been described. Here we report on a case of a prenatal test concerning a normal male carrier of the fragile X syndrome. Southern blot analysis of the fragile X gene resulted in the identification of a premutation in DNA isolated from the chorionic villus sample. Using a polymerase chain reaction (PCR)based assay the CGG repeat length was determined to be 82 CGG repeat units. Confirmation of this premutation in...

  7. RNA-mediated neurodegeneration in fragile X-associated tremor/ataxia syndrome

    OpenAIRE

    Li, Yujing; Jin, Peng

    2012-01-01

    Carriers of fragile X syndrome (FXS) have FMR1 alleles, called premutations, with a number of 5’-untranslated CGG repeats somewhere between patients, who have over 200 repeats, and normal individuals, with fewer than 60 repeats. Fragile X-associated tremor/ataxia syndrome (FXTAS), a late-onset neurodegenerative disorder, has been recognized in older male fragile X premutation carriers, and FXTAS is uncoupled from the neurodevelopmental disorder, FXS. Several lines of evidence have led to the ...

  8. Book review: the Congo, Haiti and Afghanistan: fragile states and the maintenance of violence

    OpenAIRE

    Wadi, Ramona

    2012-01-01

    Fragile States shows how the monopoly of violence is a crucial element in maintaining state fragility. By taking case studies from The Democratic Republic of Congo, Haiti and Afghanistan, the authors intend to define and clarify the meaning behind fragile statehood and to determine why outside intervention is often very limited in its actions to halt or prevent war and conflict in these countries. Ramona Wadi values the book’s analysis which, in addition to imparting a deep insight into the c...

  9. Difficult diagnosis of the fragile X syndrome made possible by direct detection of DNA mutations.

    OpenAIRE

    Tarleton, J; Wong, S.; Heitz, D.; Schwartz, C.

    1992-01-01

    Genetic recombination near the fragile X locus (Xq27.3) has frequently been a problem in linkage studies of families in which the fragile X is segregating. This case report illustrates the resolution of a difficult situation in a fragile X family for whom cytogenetic studies were inconclusive and where recombination had twice confounded attempts at prenatal DNA diagnosis by RFLP analysis. Using a newly developed DNA probe, StB12.3, for direct detection of DNA instability in the fragile X locu...

  10. Development of fragility functions to estimate homelessness after an earthquake

    Science.gov (United States)

    Brink, Susan A.; Daniell, James; Khazai, Bijan; Wenzel, Friedemann

    2014-05-01

    Immediately after an earthquake, many stakeholders need to make decisions about their response. These decisions often need to be made in a data poor environment as accurate information on the impact can take months or even years to be collected and publicized. Social fragility functions have been developed and applied to provide an estimate of the impact in terms of building damage, deaths and injuries in near real time. These rough estimates can help governments and response agencies determine what aid may be required which can improve their emergency response and facilitate planning for longer term response. Due to building damage, lifeline outages, fear of aftershocks, or other causes, people may become displaced or homeless after an earthquake. Especially in cold and dangerous locations, the rapid provision of safe emergency shelter can be a lifesaving necessity. However, immediately after an event there is little information available about the number of homeless, their locations and whether they require public shelter to aid the response agencies in decision making. In this research, we analyze homelessness after historic earthquakes using the CATDAT Damaging Earthquakes Database. CATDAT includes information on the hazard as well as the physical and social impact of over 7200 damaging earthquakes from 1900-2013 (Daniell et al. 2011). We explore the relationship of both earthquake characteristics and area characteristics with homelessness after the earthquake. We consider modelled variables such as population density, HDI, year, measures of ground motion intensity developed in Daniell (2014) over the time period from 1900-2013 as well as temperature. Using a base methodology based on that used for PAGER fatality fragility curves developed by Jaiswal and Wald (2010), but using regression through time using the socioeconomic parameters developed in Daniell et al. (2012) for "socioeconomic fragility functions", we develop a set of fragility curves that can be

  11. Seismic Fragility of the LANL Fire Water Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    Greg Mertz

    2007-03-30

    The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10{sup -3} that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels

  12. Preliminary Seismic Response and Fragility Analysis for DACS Cabinet

    International Nuclear Information System (INIS)

    A DACS cabinet is installed in the main control room. The objective of this paper is to perform seismic analyses and evaluate the preliminary structural integrity and seismic capacity of the DACS cabinet. For this purpose, a 3-D finite element model of the DACS cabinet was developed and its modal analyses are carried out to analyze the dynamic characteristics. The response spectrum analyses and the related safety evaluation are then performed for the DACS cabinet subject to seismic loads. Finally, the seismic margin and seismic fragility of the DACS cabinet are investigated. A seismic analysis and preliminary structural integrity of the DACS cabinet under self weight and SSE load have been evaluated. For this purpose, 3-D finite element models of the DACS cabinet were developed. A modal analysis, response spectrum analysis, and seismic fragility analysis were then performed. From the structural analysis results, the DACS cabinet is below the structural design limit of under SSE 0.3g, and can structurally withstand until less than SSE 3g based on an evaluation of the maximum effective stresses. The HCLPF capacity for the DGRS of the SSE 0.3g is 0.55g. A modal analysis, response spectrum analysis, and seismic fragility analysis were then performed. From the structural analysis results, the DACS cabinet is below the structural design limit of under SSE 0.3g, and can structurally withstand until less than SSE 3g based on an evaluation of the maximum effective stresses. The HCLPF capacity for the DGRS of the SSE 0.3g is 0.55g. Therefore, it is concluded that the DACS cabinet was safely designed in that no damage to the preliminary structural integrity and sufficient seismic margin is expected

  13. Implementing SPRA probabilistic fragility analysis of four typical nuclear structures

    International Nuclear Information System (INIS)

    In this paper the procedures used and the results obtained in the Seismic Probabilistic Risk Assessment (SPRA) fragility analysis are presented for four typical structures that include three year enclosures and buildings, and a turbine building complex of a pressurized water reactor (PWR) nuclear power plant (NPP) located East of the Rocky Mountains. The major procedures include structural modeling, structural dynamic analysis, failure mode and strength capacity evaluation, determination of randomness and uncertainty parameters of variables involved, and the SPRA fragility and the medium High Confidence Low Probability of Failure (HCLPF50) calculation in terms of the peak ground acceleration (PGA). The three-dimensional (3-D) structural models developed have different features from each other including a fixed-base stick model of a reinforced concrete structure physically separated from a housed tank, a stick model of a reinforced concrete structure including the effects of the housed tank response and structure-foundation interaction (SFI), a fixed-base full size steel frame structure, and a stick model with a combination of reinforced concrete and steel frame members and including the SFI effects. The 3-D response spectrum dynamic analyses were performed directly on these structure models using the site specific free field 50th percentile Uniform Hazard Spectrum shape (UHS) based on a 10,000 year return period earthquake factored to a Review Level Earthquake (RLA) Zero Period Ground Acceleration (ZPGA) of 0.4 g. Different failure modes were evaluated using the associated failure criteria for the structure models. Some insights are expected from the typical application of the SPRA probabilistic fragility analysis of nuclear structures

  14. A simplified fragility analysis of fan type cable stayed bridges

    Institute of Scientific and Technical Information of China (English)

    R. A. Khan; T. K. Datta; S. Ahmad

    2005-01-01

    A simplified fragility analysis of fan type cable stayed bridges using Probabilistic Risk Analysis (PRA)procedure is presented for determining their failure probability under random ground motion. Seismic input to the bridge support is considered to be a risk consistent response spectrum which is obtained from a separate analysis. For the response analysis, the bridge deck is modeled as a beam supported on springs at different points. The stiffnesses of the springs are determined by a separate 2D static analysis of cable-tower-deck system. The analysis provides a coupled stiffness matrix for the spring system. A continuum method of analysis using dynamic stiffness is used to determine the dynamic properties of the bridges .The response of the bridge deck is obtained by the response spectrum method of analysis as applied to multidegree of freedom system which duly takes into account the quasi - static component of bridge deck vibration. The fragility analysis includes uncertainties arising due to the variation in ground motion, material property, modeling, method of analysis,ductility factor and damage concentration effect. Probability of failure of the bridge deck is determined by the First Order Second Moment (FOSM) method of reliability. A three span double plane symmetrical fan type cable stayed bridge of total span 689 m, is used as an illustrative example. The fragility curves for the bridge deck failure are obtained under a number of parametric variations. Some of the important conclusions of the study indicate that (i) not only vertical component but also the horizontal component of ground motion has considerable effect on the probability of failure; (ii) ground motion with no time lag between support excitations provides a smaller probability of failure as compared to ground motion with very large time lag between support excitation; and (iii) probability of failure may considerably increase for soft soil condition.

  15. Seismic Fragility of the LANL Fire Water Distribution System

    International Nuclear Information System (INIS)

    The purpose of this report is to present the results of a site-wide system fragility assessment. This assessment focuses solely on the performance of the water distribution systems that supply Chemical and Metallurgy Research (CMR), Weapons Engineering and Tritium Facility (WETF), Radioactive Liquid Waste Treatment Facility (RLWTF), Waste Characterization, Reduction, Repackaging Facility (WCRRF), and Transuranic Waste Inspectable Storage Project (TWISP). The analysis methodology is based on the American Lifelines Alliance seismic fragility formulations for water systems. System fragilities are convolved with the 1995 LANL seismic hazards to develop failure frequencies. Acceptance is determined by comparing the failure frequencies to the DOE-1020 Performance Goals. This study concludes that: (1) If a significant number of existing isolation valves in the water distribution system are closed to dedicate the entire water system to fighting fires in specific nuclear facilities; (2) Then, the water distribution systems for WETF, RLWTF, WCRRF, and TWISP meet the PC-2 performance goal and the water distribution system for CMR is capable of surviving a 0.06g earthquake. A parametric study of the WETF water distribution system demonstrates that: (1) If a significant number of valves in the water distribution system are NOT closed to dedicate the entire water system to fighting fires in WETF; (2) Then, the water distribution system for WETF has an annual probability of failure on the order of 4 x 10-3 that does not meet the PC-2 performance goal. Similar conclusions are expected for CMR, RLWTF, WCRRF, and TWISP. It is important to note that some of the assumptions made in deriving the results should be verified by personnel in the safety-basis office and may need to be incorporated in technical surveillance requirements in the existing authorization basis documentation if credit for availability of fire protection water is taken at the PC-2 level earthquake levels

  16. Detect Image Tamper by Semi-Fragile Digital Watermarking

    Institute of Scientific and Technical Information of China (English)

    LIUFeilong; WANGYangsheng

    2004-01-01

    To authenticate the integrity of image while resisting some valid image processing such as JPEG compression, a semi-fragile image watermarking is described. Image name, one of the image features, has been used as the key of pseudo-random function to generate the special watermarks for the different image. Watermarks are embedded by changing the relationship between the blocks' DCT DC coefficients, and the image tamper are detected with the relationship of these DCT DC coefficients.Experimental results show that the proposed technique can resist JPEG compression, and detect image tamper in the meantime.

  17. Emerging pharmacologic treatment options for fragile X syndrome

    Directory of Open Access Journals (Sweden)

    Schaefer TL

    2015-04-01

    Full Text Available Tori L Schaefer, Matthew H Davenport, Craig A Erickson Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA Abstract: Fragile X syndrome (FXS is the most common single gene cause of intellectual disability and autism spectrum disorder. Caused by a silenced fragile X mental retardation 1 gene and the subsequent deficiency in fragile X mental retardation protein, patients with FXS experience a range of physical, behavioral, and intellectual debilitations. The FXS field, as a whole, has recently met with some challenges, as several targeted clinical trials with high expectations of success have failed to elucidate significant improvements in a variety of symptom domains. As new clinical trials in FXS are planned, there has been much discussion about the use of the commonly used clinical outcome measures, as well as study design considerations, patient stratification, and optimal age range for treatment. The evidence that modification of these drug targets and use of these failed compounds would prove to be efficacious in human clinical study were rooted in years of basic and translational research. There are questions arising as to the use of the mouse models for studying FXS treatment development. This issue is twofold: many of the symptom domains and molecular and biochemical changes assessed and indicative of efficacy in mouse model study are not easily amenable to clinical trials in people with FXS because of the intolerability of the testing paradigm or a lack of noninvasive techniques (prepulse inhibition, sensory hypersensitivity, startle reactivity, or electrophysiologic, biochemical, or structural changes in the brain; and capturing subtle yet meaningful changes in symptom domains such as sociability, anxiety, and hyperactivity in human FXS clinical trials is challenging with the currently used measures (typically parent/caregiver rating scales. Clinicians, researchers, and the

  18. State fragility and its regional implications for peace and stability

    DEFF Research Database (Denmark)

    Mandrup, Thomas

    Abstract: The East African region is characterized by heterogeneous units and by being conflict ridden. Historically the region has been plagued by both the overlay of the Cold war actors resulting in rivalry and intrastate wars, e.g. the conflict between Ethiopia and Somalia in the 1970’s. The end...... of the Cold war left a security void, and the fragility, and in some instances collapse, of the state structures resulted in new state formations and new conflicts, both intra- and inter-state in nature. However, conflicts and security challenges in East Africa are due to amongst other things porous...

  19. Seismic fragility and risk of the Beznau nuclear plant

    International Nuclear Information System (INIS)

    A probabilistic risk assessment of the Swiss Beznau Nuclear Power Plant located on the Aare River near Baden was conducted by Pickard, Lowe and Garrick, Inc., for Nordostschweizerische Kraftwerke AG. In that evaluation, system models, event tress, and fault trees were used to determine the frequency of core melt due to random equipment failure, equipment unavailabilities due to maintenance, and failures initiated by natural hazard events. Earthquakes were one of the extreme natural hazards considered. This paper discusses the fragilities of key structures and equipment that govern the seismic risk level of the Beznau plant and indicates the contribution of seismic risk to the total plant risk

  20. Seismic fragility and risk of the Beznau power plant

    International Nuclear Information System (INIS)

    In the probabilistic risk assessment of the Swiss Beznau nuclear power plant system models, event trees, and fault trees were used to determine the frequency of core melt due to random equipment failure, equipment unavailabilities due to maintenance, and failures initiated by natural hazard events. Earthquakes were one of the extreme natural hazards considered. This paper discusses the fragilities of key structures and equipment that govern the seismic risk level of the Beznau plant and indicates the contribution of seismic risk to the total plant risk. (orig./HP)

  1. Fairness in a Fragile World: The Johannesburg Agenda

    OpenAIRE

    Wolfgang Sachs

    2002-01-01

    Wolfgang Sachs, in his capacity as co-ordinator and editor of a group of 15 people that produced ‘The Johannesburg Memo: Fairness in a Fragile World’, reflects on what has to be radically different in Johannesburg if it is to catch up with the ecological disasters we are facing 10 years on (see www.joburgmemo.org for the full text). This article draws largely on part 2 of that document, ‘The Johannesburg Agenda’, which recommends a southern-led, people- and poverty-centred agenda with a move ...

  2. WATERMARKING AUTHENTICATION: USING THE FRAGILE MODE OR THE ROBUST MODE?

    Institute of Scientific and Technical Information of China (English)

    Chen Dan; Wu Qianhong; Wang Yumin

    2006-01-01

    Due to the lack of a unified authentication model certain mistakes occurred in the use of the watermarking authentication methods. To clarify the confusion, authentication models of robust and fragile watermarking are developed respectively in the paper. Concrete algorithms are proposed to prove the models that different Discrete Wavelet Transform (DWT) domains are utilized to embed the watermarks and quantization method is presented with Just Notice Differences (JNDs) threshold as the quantization size. After the key technologies about the two methods are discussed, we detail the comparison of the two modes and recommend their respective application scenarios as applicable results.

  3. A paradigm of fragile Earth in Priestley's bell jar

    OpenAIRE

    Martin, Daniel; Thompson, Andrew; Stewart, Iain; Gilbert,Edward; Hope, Katrina; Kawai, Grace; Griffiths, Alistair

    2012-01-01

    Background Photosynthesis maintains aerobic life on Earth, and Joseph Priestly first demonstrated this in his eighteenth-century bell jar experiments using mice and mint plants. In order to demonstrate the fragility of life on Earth, Priestley's experiment was recreated using a human subject placed within a modern-day bell jar. Methods A single male subject was placed within a sealed, oxygen-depleted enclosure (12.4% oxygen), which contained 274 C3 and C4 plants for a total of 48 h. A combina...

  4. A new semi-fragile watermarking algorithm for image authentication

    Institute of Scientific and Technical Information of China (English)

    HAN De-zhi; HU Yu-ping

    2005-01-01

    This paper presents a new semi-fragile watermarking algorithm for image authentication which extracts image features from the low frequency domain to generate two watermarks: one for classifying of the intentional content modification and the other for indicating the modified location. The algorithm provides an effective mechanism for image authentication. The watermark generation and watermark embedment are disposed in the image itself, and the received image authentication needs no information about the original image or watermark. The algorithm increases watermark security and prevents forged watermark. Experimental results show that the algorithm can identify intentional content modification and incidental tampering, and also indicate the location where a modification takes place.

  5. Molecular fundamentals of chromosomal mutagenesis

    International Nuclear Information System (INIS)

    Precise quantitative correlation between the yield of chromosome structure damages and the yield of DNA damages is shown when comparing data on molecular and cytogenetic investigations carried out in cultural Mammalia cells. As the chromosome structure damage is to be connected with the damage of its carcass structure, then it is natural that DNA damage in loop regions is not to affect considerably the structure, while DNA damage lying on the loop base and connected with the chromosome carcass is to play a determining role in chromosomal mutagenesis. This DNA constitutes 1-2% from the total quantity of nuclear DNA. If one accepts that damages of these regions of DNA are ''hot'' points of chromosomal mutagenesis, then it becomes clear why 1-2% of preparation damages in a cell are realized in chromosome structural damages

  6. Electochemical detection of chromosome translocation

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Dimaki, Maria; Silahtaroglu, Asli;

    2014-01-01

    Cytogenetics is a study of the cell structure with a main focus on chromosomes content and their structure. Chromosome abnormalities, such as translocations may cause various genetic disorders and heametological malignancies. Chromosome translocations are structural rearrangements of two...... hybridization approach developed for label-free detection of the chromosome translocations. For specific translocation detection it is necessary to determine that the two DNA sequences forming a derivative chromosome are connected, which is achieved by two subsequent hybridization steps. The electrochemical...... impedance spectroscopy was selected as the sensing method on a microfabricated chip with array of 12 electrode sets. Two independent chips (Chip1 and Chip2) were used for targeting the chromosomal fragments involved in the translocation. Each chip was differentially functionalized with DNA probes matching...

  7. Intraspecific chromosome variability

    Directory of Open Access Journals (Sweden)

    N Dubinin

    2010-12-01

    Full Text Available (Editorial preface. The publication is presented in order to remind us of one of dramatic pages of the history of genetics. It re-opens for the contemporary reader a comprehensive work marking the priority change from plant cytogenetics to animal cytogenetics led by wide population studies which were conducted on Drosophila polytene chromosomes. The year of the publication (1937 became the point of irretrievable branching between the directions of Old World and New World genetics connected with the problems of chromosome variability and its significance for the evolution of the species. The famous book of T. Dobzhansky (1937 was published by Columbia University in the US under the title “Genetics and the origin of species”, and in the shadow of this American ‘skybuilding’ all other works grew dim. It is remarkable that both Dobzhansky and Dubinin come to similar conclusions about the role of chromosomes in speciation. This is not surprising given that they both might be considered as representatives of the Russian genetic school, by their birth and education. Interestingly, Dobzhansky had never referred to the full paper of Dubinin et al. (1937, though a previous short communication in Nature (1936 was included together with all former papers on the related subject. In full, the volume of the original publication printed in the Biological Journal in Moscow comprised 47 pages, in that number 41 pages of the Russian text accompanied by 16 Figs, a table and reference list, and, above all, 6 pages of the English summary. This final part in English is now reproduced in the authors’ version with the only addition being the reference list in the originally printed form.

  8. Reference-assisted chromosome assembly

    OpenAIRE

    Kim, Jaebum; Larkin, Denis M; Cai, Qingle; Asan,; Zhang, Yongfen; Ge, Ri-Li; Auvil, Loretta; Capitanu, Boris; Zhang, Guojie; Lewin, Harris A.; Ma, Jian

    2013-01-01

    One of the most difficult problems in modern genomics is the assembly of full-length chromosomes using next generation sequencing (NGS) data. To address this problem, we developed “reference-assisted chromosome assembly” (RACA), an algorithm to reliably order and orient sequence scaffolds generated by NGS and assemblers into longer chromosomal fragments using comparative genome information and paired-end reads. Evaluation of results using simulated and real genome assemblies indicates that ou...

  9. Chromosome Connections: Compelling Clues to Common Ancestry

    Science.gov (United States)

    Flammer, Larry

    2013-01-01

    Students compare banding patterns on hominid chromosomes and see striking evidence of their common ancestry. To test this, human chromosome no. 2 is matched with two shorter chimpanzee chromosomes, leading to the hypothesis that human chromosome 2 resulted from the fusion of the two shorter chromosomes. Students test that hypothesis by looking for…

  10. Disabled-1 is a large common fragile site gene, inactivated in multiple cancers.

    Science.gov (United States)

    McAvoy, Sarah; Zhu, Yu; Perez, Damon S; James, C David; Smith, David I

    2008-02-01

    Common fragile sites (CFS) are large, genomically unstable regions, which are hot-spots for deletions and other alterations, especially in cancer cells. Several have been shown to contain genes that span large genomic regions, such as FHIT (1.5 Mb), WWOX (1.0 Mb), GRID2 (1.36 Mb), PARK2 (1.3 Mb), and RORA (730 kb). These genes are frequently inactivated in multiple different cancers, and FHIT and WWOX are shown to function as tumor suppressors. The disabled-1 gene (DAB1) is one of the human homologs of the Drosophila disabled locus, which in mammals is involved in neuronal migration and lamination in the developing cerebral cortex. Mice DAB1 inactivation results in the neurological mutant Scrambler, having similarities to mice with the inactivation of PARK2 (Quaker), GRID2 (Lurcher), and RORA (Staggerer). We were interested in whether DAB1 was another large CFS gene that could have cancer development importance. We demonstrated here that the human DAB1 gene (spanning 1.25 Mb) mapped within FRA1B CFS region on chromosomal band 1p32.2. Real-time RT-PCR analysis revealed that the expression level of DAB1 was decreased in many human cancer samples, including primary tumor tissues and cancer-derived cell lines, from several different cancers, especially in brain and endometrial cancer. Additionally, the introduction of an over-expression DAB1 plasmid into two different cell lines, having insignificant endogenous DAB1 expression, resulted in decreased cell growth. In summary, DAB1 is another gene that resides within an unstable CFS region and might play a role in human tumorigenesis. These data may provide further linkage between neurological development and cancer. PMID:18008369

  11. In vivo brain anatomy of adult males with Fragile X syndrome: an MRI study.

    LENUS (Irish Health Repository)

    Hallahan, Brian P

    2011-01-01

    Fragile X Syndrome (FraX) is caused by the expansion of a single trinucleotide gene sequence (CGG) on the X chromosome, and is a leading cause of learning disability (mental retardation) worldwide. Relatively few studies, however, have examined the neuroanatomical abnormalities associated with FraX. Of those that are available many included mixed gender populations, combined FraX children and adults into one sample, and employed manual tracing techniques which measures bulk volume of particular regions. Hence, there is relatively little information on differences in grey and white matter content across whole brain. We employed magnetic resonance imaging to investigate brain anatomy in 17 adult males with FraX and 18 healthy controls that did not differ significantly in age. Data were analysed using stereology and VBM to compare (respectively) regional brain bulk volume, and localised grey\\/white matter content. Using stereology we found that FraX males had a significant increase in bulk volume bilaterally of the caudate nucleus and parietal lobes and of the right brainstem, but a significant decrease in volume of the left frontal lobe. Our complimentary VBM analysis revealed an increased volume of grey matter in fronto-striatal regions (including bilaterally in the caudate nucleus), and increased white matter in regions extending from the brainstem to the parahippocampal gyrus, and from the left cingulate cortex extending into the corpus callosum. People with FraX have regionally specific differences in brain anatomy from healthy controls with enlargement of the caudate nuclei that persists into adulthood.

  12. Fragile X mental retardation protein interacts with TDG

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fragile X syndrome is the most common form of inherited mental retardation disease,resulting from absent of expression of its disease gene FMR1.To study the function of the fragile X mental retardation protein (FMRP) through protein/protein interaction,a mouse embryo cDNA library was screened by the yeast two-hybrid system.A clone was found to interact specifically with FMRP.The cDNA of this clone ( Genbank accession number af102875 ) encoded a protein highly homologous to human G/T mismatch-specific DNA thymine glycosylase ( hTDG ).Interactions between various alternatively spliced FMRP isoforms and a series of mTDG deletion proteins were further studied in the yeast two-hybrid system and their interaction amino acid regions were determined.Interaction between FMRP and TDG existed inside exon 13 of FMRP ( amino acid residue 397-425 ) and around amino acid residue 122-346 of TDG.These results will be helpful to the study of the biological role of FMRP.

  13. Drift-free MPEG-4 AVC semi-fragile watermarking

    Science.gov (United States)

    Hasnaoui, M.; Mitrea, M.

    2014-02-01

    While intra frame drifting is a concern for all types of MPEG-4 AVC compressed-domain video processing applications, it has a particular negative impact in watermarking. In order to avoid the drift drawbacks, two classes of solutions are currently considered in the literature. They try either to compensate the drift distortions at the expense of complex decoding/estimation algorithms or to restrict the insertion to the blocks which are not involved in the prediction, thus reducing the data payload. The present study follows a different approach. First, it algebraically models the drift distortion spread problem by considering the analytic expressions of the MPEG-4 AVC encoding operations. Secondly, it solves the underlying algebraic system under drift-free constraints. Finally, the advanced solution is adapted to take into account the watermarking peculiarities. The experiments consider an m-QIM semi-fragile watermarking method and a video surveillance corpus of 80 minutes. For prescribed data payload (100 bit/s), robustness (BER < 0.1 against transcoding at 50% in stream size), fragility (frame modification detection with accuracies of 1/81 from the frame size and 3s) and complexity constraints, the modified insertion results in gains in transparency of 2 dB in PSNR, of 0.4 in AAD, of 0.002 in IF, of 0.03 in SC, of 0.017 NCC and 22 in DVQ.

  14. Tunnelling through weak and fragile rocks of Himalayas

    Institute of Scientific and Technical Information of China (English)

    Goel R.K.

    2014-01-01

    A considerable amount of tunnelling has been going on in India for various projects such as hydroelectric power, irrigation, roads and railways. Most of these projects are located in Himalayas, far away from the urban areas. Tunnelling through weak and jointed rock masses such as the one in the Himalayas is a challenging task for the planners, designers, engineers and geologists because of high overburden, thickly vegetated surface, weak, poor and fragile rocks and highly varying geology with the presence of numerous small and big shear zones, faults, etc. Due to these reasons, various tunnelling problems have been faced in the past and are still being encountered. Failures and the problems may be regarded as challenges and opportunities for generating new knowledge base and thereby increasing self-reliance in tunnelling. The experiences of Himalayan tunnelling through weak and fragile rocks covering varying and mixed geology, understanding on tunnelling in squeezing ground conditions and applicability of TBM in Himalayas are presented. It has also been highlighted that the probe holes planning, drilling and mon-itoring shall be followed seriously to reduce the geological surprises.

  15. Fragility assessment method of Concrete Wall Subjected to Impact Loading

    Energy Technology Data Exchange (ETDEWEB)

    Hahm, Daegi; Shin, Sang Shup; Choi, In-Kil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    These studies have been aimed to verify and ensure the safety of the targeted walls and structures especially in the viewpoint of the deterministic approach. However, recently, the regulation and the assessment of the safety of the nuclear power plants (NPPs) against to an aircraft impact are strongly encouraged to adopt a probabilistic approach, i.e., the probabilistic risk assessment of an aircraft impact. In Korea, research to develop aircraft impact risk quantification technology was initiated in 2012 by Korea Atomic Energy Research Institute (KAERI). In this paper, for the one example of the probabilistic safety assessment approach, a method to estimate the failure probability and fragility of concrete wall subjected to impact loading caused by missiles or engine parts of aircrafts will be introduced. This method and the corresponding results will be used for the total technical roadmap and the procedure to assess the aircraft impact risk (Fig.1). A method and corresponding results of the estimation of the failure probability and fragility for a concrete wall subjected to impact loadings caused by missiles or engine parts of aircrafts was introduced. The detailed information of the target concrete wall in NPP, and the example aircraft engine model is considered safeguard information (SGI), and is not contained in this paper.

  16. Thinking through health capacity development for Fragile States.

    Science.gov (United States)

    Mark, Annabelle; Jones, Mike

    2013-01-01

    The purpose of this paper is to consider capacity development for healthcare in Fragile States and its roles, for example, in securing civil and political stability, as well as improved health, within the various contexts prevailing in fragile settings across the world. As a precursor to this, however, it is important to understand how, in rapidly changing environments, the role and contribution of different donors will have an impact in different ways. This paper sets out to interpret these issues, and what becomes apparent is the need to develop an understanding of the value base of donors, which we demonstrate through the development of a value-based framework. This highlights the separate motivations and choices made by donors, but what is apparent is that all remain within the positivist perspective perhaps for reasons of accountability and transparency. However, the emergence of new interpretations drawing on systems thinking, and followed by complexity theory more recently, in understanding contexts, suggests that the favouring of any one of these perspective can be counterproductive, without a consideration of the contexts in which they occur. In seeking an explanation of these environmental contexts, which also address the perspectives in use, we suggest the use of wider multi-ontology sense-making framework such as Cynefin. Through this approach, analytical insights can be given into the interpretation, decision and intervention processes available in these different and often changing environments, thus enabling greater coherence between donor values and recipient contexts. PMID:23047746

  17. Loss of fragile histidine triad protein in human hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Po Zhao; Xin Song; Yuan-Yuan Nin; Ya-Li Lu; Xiang-Hong Li

    2003-01-01

    AIM: To investigate the expression of fragile histidine triad (FHIT) gene protein, Fhit, which is recently thought to be a candidate tumor suppressor. Abnormal expression of fragile histidine triad has been found in a variety of human cancers,but little is known about its expression in human hepatocellular carcinogenesis and evolution.METHODS: Sections of 83 primary human hepatocellular carcionoma with corresponding para-neoplastic liver tissue and 10 normal liver tissue were evaluated immunohistochemically for Fhit protein expression.RESULTS: All normal liver tissue and para-neoplastic liver tissue showed a strong expression of Fhit, whereas 50 of 83(65.0 %) carcinomas showed a marked loss or absence of Fhit expression. The differences of Fhit expression between carcinoma and normal or para-neoplastic liver tissue werehighly significant (P=0.000). The proportion of carcinomas with reduced Fhit expression showed an increasing trend (a) with decreasing differentiation or higher histological grade (P=0.219); (b) in tumors with higher clinical stage Ⅲ and ⅣV (91.3 %, P=0.000), compared with tumors with lower stage Ⅰ and Ⅱ (27.6 %); and (c) in cancers with bigger tumor size (>50 mm) (75.0 %, P=0.017), compared withsmaller tumor size (≤ 50 mm). CONCLUSION: FHIT inactivation seems to be both an earlyand a later event, associated with carcinogenesis andprogression to more aggressive hepatocellular carcinomas.Thus, evaluation of Fhit expression by immunohistochemistryin hepatocellular carcinoma may provide important diagnosticand prognostic information in clinical application.

  18. Molecular analysis of fragile X syndrome in Antalya Province

    Directory of Open Access Journals (Sweden)

    Bilgen T

    2005-04-01

    Full Text Available Background: Detection of the (CGGn repeats in the FMR1 gene that cause the fragile X syndrome (FXS, has become a milestone for phenotype-genotype correlation in FXS. Aims: To screen the FMR1 gene CGG repeats in index cases with FXS and their family members in the Antalya Province. Setting and design: This study was prospectively conducted between January 200and March 2005 in Department of Medical Biology and Genetics, Faculty of Medicine, Akdeniz University, Antalya. Materials and Methods: A series of 132 cases from three hospitals in Antalya Province were studied. All cases were molecularly screened using non-radioactive Expand Long PCR method that was confirmed by Southern blotting. Results: Seventeen out of 132 cases were found to have a full mutation, including three that were mosaic for premutations/full mutations. Of the 132 cases, eight were found to have the premutation size of the CGG repeats. The remaining 107 cases were identified as normal. Conclusions: Due to premature ovarian failure and Fragile X premutation Tremor/Ataxia Syndrome related with the premutation, the detection of the premutation will provide valuable information both for clinical follow-up and genetic counseling. In conclusion, our data suggest that expansion of CGG repeats in the FMR1 gene can be analyzed by Expand Long PCR, an efficient and non-radioactive method that can be used to monitor the expansion of premutation to full mutation, which would eventually lead to reduce the FXS prevalence.

  19. Fragility assessment method of Concrete Wall Subjected to Impact Loading

    International Nuclear Information System (INIS)

    These studies have been aimed to verify and ensure the safety of the targeted walls and structures especially in the viewpoint of the deterministic approach. However, recently, the regulation and the assessment of the safety of the nuclear power plants (NPPs) against to an aircraft impact are strongly encouraged to adopt a probabilistic approach, i.e., the probabilistic risk assessment of an aircraft impact. In Korea, research to develop aircraft impact risk quantification technology was initiated in 2012 by Korea Atomic Energy Research Institute (KAERI). In this paper, for the one example of the probabilistic safety assessment approach, a method to estimate the failure probability and fragility of concrete wall subjected to impact loading caused by missiles or engine parts of aircrafts will be introduced. This method and the corresponding results will be used for the total technical roadmap and the procedure to assess the aircraft impact risk (Fig.1). A method and corresponding results of the estimation of the failure probability and fragility for a concrete wall subjected to impact loadings caused by missiles or engine parts of aircrafts was introduced. The detailed information of the target concrete wall in NPP, and the example aircraft engine model is considered safeguard information (SGI), and is not contained in this paper

  20. X-chromosome workshop.

    Science.gov (United States)

    Paterson, A D

    1998-01-01

    Researchers presented results of ongoing research to the X-chromosome workshop of the Fifth World Congress on Psychiatric Genetics, covering a wide range of disorders: X-linked infantile spasms; a complex phenotype associated with deletions of Xp11; male homosexuality; degree of handedness; bipolar affective disorder; schizophrenia; childhood onset psychosis; and autism. This report summarizes the presentations, as well as reviewing previous studies. The focus of this report is on linkage findings for schizophrenia and bipolar disorder from a number of groups. For schizophrenia, low positive lod scores were obtained for markers DXS991 and DXS993 from two studies, although the sharing of alleles was greatest from brother-brother pairs in one study, and sister-sister in the other. Data from the Irish schizophrenia study was also submitted, with no strong evidence for linkage on the X chromosome. For bipolar disease, following the report of a Finnish family linked to Xq24-q27, the Columbia group reported some positive results for this region from 57 families, however, another group found no evidence for linkage to this region. Of interest, is the clustering of low positive linkage results that point to regions for possible further study. PMID:9686435

  1. Chromosome analysis and sorting

    Czech Academy of Sciences Publication Activity Database

    Doležel, Jaroslav; Kubaláková, Marie; Suchánková, Pavla; Kovářová, Pavlína; Bartoš, Jan; Šimková, Hana

    Weinheim : Wiley-VCH, 2007 - (Doležel, J.; Greilhuber, J.; Suda, J.), s. 373-403 ISBN 978-3-527-31487-4 R&D Projects: GA ČR GA521/04/0607; GA ČR GP521/05/P257; GA ČR GD521/05/H013; GA MŠk(CZ) LC06004 Grant ostatní: Mendelova zemědělská a lesnická univerzita v Brně / Agronomická fakulta(CZ) ME 844 Institutional research plan: CEZ:AV0Z5038910 Source of funding: V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje ; V - iné verejné zdroje Keywords : Plant flow cytometry * chromosome sorting * flow cytogenetics Subject RIV: EB - Genetics ; Molecular Biology http://books. google .com/books?id=3cwakORieqUC&pg=PA373&lpg=PA373&dq=Chromosome+analysis+and+sorting&source=web&ots=8IyvJlBQyq&sig=_NlXyQQgBCwpj1pTC9YITvvVZqU

  2. 5'azacytidine effect in bovine lymphocytes chromosomes Acción de la 5'azacitidina en cromosomas de células linfocitarias de bovinos

    OpenAIRE

    Arruga María; Gagliardi Rosa; Coppola Betina; Tejedor Teresa; Llambí Silvia

    2008-01-01

    Azacytidine (5–azaC) is a substance that inhibits the metilation of DNA, being used in cloning experiments, nuclear transference transgenesis and in chromosomal fragility studies. The manifestation of diverse pathologies has been observed in domestic animals born from cloning experiments. These would be associated to an incorrect nuclear reprogramation related to epigenetic metilation phenomena of the DNA. In the present work an inductio...

  3. The gene for human erythrocyte protein 4. 2 maps to chromosome 15q15

    Energy Technology Data Exchange (ETDEWEB)

    Najfeld, V. (Mount Sinai School of Medicine, NY (United States)); Ballard, S.G.; Menninger, J.; Ward, D.C. (Yale Univ., New Haven, CT (United States)); Bouhassira, E.E.; Schwartz, R.S.; Nagel, R.L.; Rybicki, A.C. (Albert Einstein Coll. of Medicine/Montefiore Medical Center, Bronx, NY (United States))

    1992-01-01

    Protein 4.2 (P4.2), one of the major components of the red-blood-cell membrane, is located on the interior surface, where it binds with high affinity to the cytoplasmic domain of band 3. Individuals whose red blood cells are deficient in P4.2 have osmotically fragile, abnormally shaped cells and moderate hemolytic anemia. cDNA clones from both the 5{prime} and the 3{prime} coding regions of the P4.2 gene were used to map its chromosomal location by fluorescence in situ hybridization. The probes, individually or in combination, gave specific hybridization signals on chromosome 15. The hybridization locus was identified by combining fluorescence images of the probe signals with fluorescence banding patterns generated by Alu-PCR (R-like) probe and by DAPI staining (G-like). The authors results demonstrate that the locus of the P4.2 gene is located within 15q15.

  4. Chromosomal break points in irradiated and ethyl methane sulphonate treated leucocytes of patients with Down syndrome

    International Nuclear Information System (INIS)

    Frequencies of chromosomal damage in the peripheral leucocytes of patients with Down syndrome, on exposure to gamma rays (2Gy) or ethyl methane sulphonate (EMS, 1 x 10-4M), were assessed. Analysis of break points in the chromosomes of irradiated cells revealed a non-random occurrence. Six of the break points observed in EMS-treated cells were found to overlap with those recorded in irradiated cells. Thirteen break points observed were found to correlate with the location of cancer-specific break points and four of these coincided with the bands where oncogenes have been located. Two break points were localised to the same bands as that of known heritable fragile sites. (author). 17 refs., 2 figs., 3 tabs

  5. Cerebral protein synthesis in a knockin mouse model of the fragile X premutation

    NARCIS (Netherlands)

    M. Qin (Mei); T. Huang (Tianjian); Z. Liu (Zhonghua); M. Kader (Michael); T. Burlin (Thomas); Z. Xia (Zengyan); Z. Zeidler (Zachary); R.K. Hukema (Renate); C.B. Smith (Carolyn B.)

    2014-01-01

    textabstractThe (CGG)n-repeat in the 5’-untransiated region of the fragile X mental retardation gene (FMRi) gene is polymorphic and may become unstable on transmission to the next generation. In fragile X syndrome, CGG repeat lengths exceed 200, resulting in silencing of FMRi and absence of its prot

  6. Delineating the Profile of Autism Spectrum Disorder Characteristics in Cornelia de Lange and Fragile X Syndromes

    Science.gov (United States)

    Moss, Joanna; Oliver, Chris; Nelson, Lisa; Richards, Caroline; Hall, Scott

    2013-01-01

    An atypical presentation of autism spectrum disorder is noted in Cornelia de Lange and Fragile X syndromes, but there are few detailed empirical descriptions. Participants in this study were individuals with Cornelia de Lange syndrome (n = 130, M age = 17.19), Fragile X syndrome (n = 182, M age = 16.94), and autism spectrum disorder (n = 142, M…

  7. The correlation between fragility, density, and atomic interaction in glass-forming liquids

    Science.gov (United States)

    Wang, Lijin; Guan, Pengfei; Wang, W. H.

    2016-07-01

    The fragility that controls the temperature-dependent viscous properties of liquids as the glass transition is approached, in various glass-forming liquids with different softness of the repulsive part of atomic interactions at different densities, is investigated by molecular dynamic simulations. We show that the landscape of fragility in purely repulsive systems can be separated into three regions denoted as RI, RII, and RIII, respectively, with qualitatively disparate dynamic behaviors: RI which can be described by "softness makes strong glasses," RII where fragility is independent of softness and can only be tuned by density, and RIII with constant fragility, suggesting that density plays an unexpected role for understanding the repulsive softness dependence of fragility. What is more important is that we unify the long-standing inconsistence with respect to the repulsive softness dependence of fragility by observing that a glass former can be tuned more fragile if nonperturbative attraction is added into it. Moreover, we find that the vastly dissimilar influences of attractive interaction on fragility could be estimated from the structural properties of related zero-temperature glasses.

  8. Effective updating process of seismic fragilities using Bayesian method and information entropy

    International Nuclear Information System (INIS)

    Seismic probabilistic safety assessment (SPSA) is an effective method for evaluating overall performance of seismic safety of a plant. Seismic fragilities are estimated to quantify the seismically induced accident sequences. It is a great concern that the SPSA results involve uncertainties, a part of which comes from the uncertainty in the seismic fragility of equipment and systems. A straightforward approach to reduce the uncertainty is to perform a seismic qualification test and to reflect the results on the seismic fragility estimate. In this paper, we propose a figure-of-merit to find the most cost-effective condition of the seismic qualification tests about the acceleration level and number of components tested. Then a mathematical method to reflect the test results on the fragility update is developed. A Bayesian method is used for the fragility update procedure. Since a lognormal distribution that is used for the fragility model does not have a Bayes conjugate function, a parameterization method is proposed so that the posterior distribution expresses the characteristics of the fragility. The information entropy is used as the figure-of-merit to express importance of obtained evidence. It is found that the information entropy is strongly associated with the uncertainty of the fragility. (author)

  9. Autistic Features, Personality, and Adaptive Behavior in Males with the Fragile X Syndrome and No Autism.

    Science.gov (United States)

    Kerby, Dave S.; Dawson, Brenda L.

    1994-01-01

    Nine adult males with mental retardation resulting from Fragile X syndrome were compared to males with mental retardation of other etiology. Fragile X males showed a distinct psychological profile with more autistic features, more schizoid features, and more schizotypal features. These males were also more shy, more socially withdrawn, less…

  10. Mathematics Learning Disabilities in Girls with Fragile X or Turner Syndrome during Late Elementary School

    Science.gov (United States)

    Murphy, Melissa M.; Mazzocco, Michele M. M.

    2008-01-01

    The present study focuses on math and related skills among 32 girls with fragile X (n = 14) or Turner (n = 18) syndrome during late elementary school. Performance in each syndrome group was assessed relative to Full Scale IQ-matched comparison groups of girls from the general population (n = 32 and n = 89 for fragile X syndrome and Turner…

  11. Behavioral Assessment of Social Anxiety in Females with Turner or Fragile X Syndrome.

    Science.gov (United States)

    Lesniak-Karpiak, Katarzyna; Mazzocco, Michele M. M.; Ross, Judith L.

    2003-01-01

    This study compared 29 females with Turner syndrome and 21 females with fragile X syndrome (ages 6-22) on a videotaped role-play interaction with 34 females in a comparison group. Three of eight behavioral measures of social skills differentiated the participant groups. Fragile-X subjects required more time to initiate interactions and Turner…

  12. Resolution of Spatial and Temporal Visual Attention in Infants with Fragile X Syndrome

    Science.gov (United States)

    Farzin, Faraz; Rivera, Susan M.; Whitney, David

    2011-01-01

    Fragile X syndrome is the most common cause of inherited intellectual impairment and the most common single-gene cause of autism. Individuals with fragile X syndrome present with a neurobehavioural phenotype that includes selective deficits in spatiotemporal visual perception associated with neural processing in frontal-parietal networks of the…

  13. Discourse Skills of Boys with Fragile X Syndrome in Comparison to Boys with Down Syndrome

    Science.gov (United States)

    Roberts, Joanne; Martin, Gary E.; Moskowitz, Lauren; Harris, Adrianne A.; Foreman, Jamila; Nelson, Lauren

    2007-01-01

    Purpose: This study compared the conversational discourse skills of boys who have fragile X syndrome with and without autism spectrum disorder (ASD) with those of boys with Down syndrome and boys who are typically developing. Method: Participants were boys who have fragile X syndrome with (n = 26) and without (n = 28) ASD, boys with Down syndrome…

  14. Early White-Matter Abnormalities of the Ventral Frontostriatal Pathway in Fragile X Syndrome

    Science.gov (United States)

    Haas, Brian W.; Barnea-Goraly, Naama; Lightbody, Amy A.; Patnaik, Swetapadma S.; Hoeft, Fumiko; Hazlett, Heather; Piven, Joseph; Reiss, Allan L.

    2009-01-01

    Aim: Fragile X syndrome is associated with cognitive deficits in inhibitory control and with abnormal neuronal morphology and development. Method: In this study, we used a diffusion tensor imaging (DTI) tractography approach to reconstruct white-matter fibers in the ventral frontostriatal pathway in young males with fragile X syndrome (n = 17;…

  15. Examining the Function of Problem Behavior in Fragile X Syndrome: Preliminary Experimental Analysis

    Science.gov (United States)

    Langthorne, Paul; McGill, Peter; O'Reilly, Mark F.; Lang, Russell; Machalicek, Wendy; Chan, Jeffrey Michael; Rispoli, Mandy

    2011-01-01

    Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis…

  16. Adaptive Skills, Behavior Problems, and Parenting Stress in Mothers of Boys with Fragile X Syndrome

    Science.gov (United States)

    Sarimski, Klaus

    2010-01-01

    The relationship of temperament, atypical behaviors, and adaptive behavior of young boys with Fragile X syndrome on mothers' parenting stress was analyzed. Twenty-six boys with Fragile X syndrome (30-88 months of age) participated. The overall development of the participants was significantly delayed with a specific profile of adaptive behaviors…

  17. Differences in Visual Orienting between Persons with Down or Fragile X Syndrome

    Science.gov (United States)

    Flanagan, Tara; Enns, James T.; Murphy, Melissa M.; Russo, Natalie; Abbeduto, Leonard; Randolph, Beth; Burack, Jacob A.

    2007-01-01

    The voluntary and reflexive orienting abilities of persons with Down syndrome and fragile X syndrome, at average MA levels of approximately 4 and 7 years, were compared with an RT task. Reflexive orienting abilities appeared to develop in accordance with MA for the participants with Down syndrome but not for those with fragile X syndrome. However,…

  18. The Trajectory of Mathematics Skills and Working Memory Thresholds in Girls with Fragile X Syndrome

    Science.gov (United States)

    Murphy, Melissa M.; Mazzocco, Michele M. M.

    2009-01-01

    Fragile X syndrome is a common genetic disorder associated with executive function deficits and poor mathematics achievement. In the present study, we examined changes in math performance during the elementary and middle school years in girls with fragile X syndrome, changes in the working memory loads under which children could complete a…

  19. Positron Emission Tomography (PET Quantification of GABAA Receptors in the Brain of Fragile X Patients.

    Directory of Open Access Journals (Sweden)

    Charlotte D'Hulst

    Full Text Available Over the last several years, evidence has accumulated that the GABAA receptor is compromised in animal models for fragile X syndrome (FXS, a common hereditary form of intellectual disability. In mouse and fly models, agonists of the GABAA receptor were able to rescue specific consequences of the fragile X mutation. Here, we imaged and quantified GABAA receptors in vivo in brain of fragile X patients using Positron Emission Topography (PET and [11C]flumazenil, a known high-affinity and specific ligand for the benzodiazepine site of GABAA receptors. We measured regional GABAA receptor availability in 10 fragile X patients and 10 control subjects. We found a significant reduction of on average 10% in GABAA receptor binding potential throughout the brain in fragile X patients. In the thalamus, the brain region showing the largest difference, the GABAA receptor availability was even reduced with 17%. This is one of the first reports of a PET study of human fragile X brain and directly demonstrates that the GABAA receptor availability is reduced in fragile X patients. The study reinforces previous hypotheses that the GABAA receptor is a potential target for rational pharmacological treatment of fragile X syndrome.

  20. Prepulse Inhibition in Patients with Fragile X-associated Tremor Ataxia Syndrome

    OpenAIRE

    Schneider, Andrea; Ballinger, Elizabeth; Chavez, Alyssa; Tassone, Flora; Randi J Hagerman; Hessl, David

    2010-01-01

    Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that affects carriers of the fragile X premutation, typically after age 50. Common symptoms include intention tremor, ataxia, neuropathy, autonomic dysfunction, cognitive decline, and dementia.

  1. Does Attention Constrain Developmental Trajectories in Fragile X Syndrome? A 3-Year Prospective Longitudinal Study

    Science.gov (United States)

    Cornish, Kim; Cole, Victoria; Longhi, Elena; Karmiloff-Smith, Annette; Scerif, Gaia

    2012-01-01

    Basic attentional processes and their impact on developmental trajectories in fragile X syndrome were assessed in a 3-year prospective study. Although fragile X syndrome is a monogenic X-linked disorder, there is striking variability in outcomes even in young boys with the condition. Attention is a key factor constraining interactions with the…

  2. Behavioral Intervention for Problem Behavior in Children with Fragile X Syndrome

    Science.gov (United States)

    Moskowitz, Lauren J.; Carr, Edward G.; Durand, V. Mark

    2011-01-01

    Parents and professionals typically report problem behavior as a significant concern for children with fragile X syndrome. In the present study, the authors explored whether behaviorally based interventions would result in a reduction in problem behavior and an improvement in quality of life for 3 children with fragile X syndrome and their…

  3. Expressive Language during Conversational Speech in Boys with Fragile X Syndrome

    Science.gov (United States)

    Roberts, Joanne E.; Hennon, Elizabeth A.; Price, Johanna R.; Dear, Elizabeth; Anderson, Kathleen; Vandergrift, Nathan A.

    2007-01-01

    We compared the expressive syntax and vocabulary skills of 35 boys with fragile X syndrome and 27 younger typically developing boys who were at similar nonverbal mental levels. During a conversational speech sample, the boys with fragile X syndrome used shorter, less complex utterances and produced fewer different words than did the typically…

  4. An Investigation of Narrative Ability in Boys with Autism and Fragile X Syndrome

    Science.gov (United States)

    Hogan-Brown, Abigail L.; Losh, Molly; Martin, Gary E.; Mueffelmann, Deborah J.

    2013-01-01

    Whereas pragmatic language difficulties are characteristic of both autism and Fragile X syndrome, it is unclear whether such deficits are qualitatively similar or whether certain skills are differentially affected. This study compared narrative competence in boys with autism, Fragile X syndrome, Down syndrome, and typical development. Results…

  5. Public private cooperation fragile states: Report on field research mission to North Kivu and Ituri

    NARCIS (Netherlands)

    Douma, P.; Bolhuis, E.E.; Klaver, D.C.; Zawadi, Y.

    2009-01-01

    This field study is part of the Schokland project to research among others the possibilities for Public Private Cooperation (PPC) in stimulating Economic Growth in Fragile States. Fragile states are relatively far behind in achieving the Millennium Development Goals (MDGs) and in order to reduce fra

  6. Identifying aid effectiveness challenges in fragile and conflict-affected states

    OpenAIRE

    Ishihara, Yoichiro

    2012-01-01

    Fragile and conflict-affected states face daunting challenges for development. Aid has a greater importance on development in these states than in others, and therefore aid effectiveness management and delivery of aid bears serious consideration. Despite its significance, aid effectiveness is appreciably lower in fragile and conflict-affected states than in others. What are the key aid ...

  7. Between Development and Security: The European Union, Governance and Fragile States

    NARCIS (Netherlands)

    W. Hout (Wil)

    2009-01-01

    textabstractThis paper presents an analysis of recently adopted EU policies on fragile states. While the European Union has incorporated governance issues into its strategies for fragile states, its approach to governance has a highly technocratic character, with a strong emphasis on public sector r

  8. Success in Difficult Environments : A Portfolio Analysis of Fragile and Conflict-Affected States

    OpenAIRE

    Ralston, Laura

    2014-01-01

    The World Bank Group has identified support to fragile and conflict-affected states as a strategic priority. This paper provides a systematic portfolio review of the International Development Association-funded projects in fragile and conflict-affected states during 2001 to 2013 and a detailed empirical analysis of the correlations between project and country-level characteristics with pro...

  9. Promoting democracy in fragile states : insights from a field experiment in Liberia

    OpenAIRE

    Mvukiyehe, Eric; Samii, Cyrus

    2015-01-01

    A field experiment in rural Liberia is used to study democratic participation in fragile states. Fragile states are marked by political fragmentation, local patronage systems, and voter vulnerability. To understand the effects of such conditions on democratic expression through elections, the experiment introduced new forms of interaction between rural citizens and third-party actors: (i) ...

  10. Cohesin in determining chromosome architecture

    Energy Technology Data Exchange (ETDEWEB)

    Haering, Christian H., E-mail: christian.haering@embl.de [Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg (Germany); Jessberger, Rolf, E-mail: rolf.jessberger@tu-dresden.de [Institute of Physiological Chemistry, Dresden University of Technology, Dresden (Germany)

    2012-07-15

    Cells use ring-like structured protein complexes for various tasks in DNA dynamics. The tripartite cohesin ring is particularly suited to determine chromosome architecture, for it is large and dynamic, may acquire different forms, and is involved in several distinct nuclear processes. This review focuses on cohesin's role in structuring chromosomes during mitotic and meiotic cell divisions and during interphase.

  11. Causes of oncogenic chromosomal translocation

    OpenAIRE

    Aplan, Peter D.

    2005-01-01

    Non-random chromosomal translocations are frequently associated with a variety of cancers, especially hematologic malignancies and childhood sarcomas In addition to their diagnostic utility, chromosomal translocations are increasingly being used in the clinic to guide therapeutic decisions. However, the mechanisms which cause these translocations remain poorly understood. Illegit...

  12. Handbook of nuclear power plant seismic fragilities, Seismic Safety Margins Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Cover, L.E.; Bohn, M.P.; Campbell, R.D.; Wesley, D.A.

    1983-12-01

    The Seismic Safety Margins Research Program (SSMRP) has a gola to develop a complete fully coupled analysis procedure (including methods and computer codes) for estimating the risk of an earthquake-induced radioactive release from a commercial nuclear power plant. As part of this program, calculations of the seismic risk from a typical commercial nuclear reactor were made. These calculations required a knowledge of the probability of failure (fragility) of safety-related components in the reactor system which actively participate in the hypothesized accident scenarios. This report describes the development of the required fragility relations and the data sources and data reduction techniques upon which they are based. Both building and component fragilities are covered. The building fragilities are for the Zion Unit 1 reactor which was the specific plant used for development of methodology in the program. Some of the component fragilities are site-specific also, but most would be usable for other sites as well.

  13. Handbook of nuclear power plant seismic fragilities, Seismic Safety Margins Research Program

    International Nuclear Information System (INIS)

    The Seismic Safety Margins Research Program (SSMRP) has a gola to develop a complete fully coupled analysis procedure (including methods and computer codes) for estimating the risk of an earthquake-induced radioactive release from a commercial nuclear power plant. As part of this program, calculations of the seismic risk from a typical commercial nuclear reactor were made. These calculations required a knowledge of the probability of failure (fragility) of safety-related components in the reactor system which actively participate in the hypothesized accident scenarios. This report describes the development of the required fragility relations and the data sources and data reduction techniques upon which they are based. Both building and component fragilities are covered. The building fragilities are for the Zion Unit 1 reactor which was the specific plant used for development of methodology in the program. Some of the component fragilities are site-specific also, but most would be usable for other sites as well

  14. Robust and fragile Werner states in the collective dephasing Robust and fragile Werner states in the collective dephasing

    CERN Document Server

    Li, S B; Li, S B; Xu, J B; Li, Shang-Bin; Xu, Jing-Bo; Li, Shang-Bin; Xu, Jing-Bo

    2005-01-01

    We investigate the concurrence and Bell violation of the Werner or Werner-like states in the presence of collective dephasing. It is shown that the Werner and certain kinds of Werner-like states are robust against the collective dephasing, and some kinds of Werner-like states is fragile and becomes completely disentangled in a finite-time. The threshold time of complete disentanglement of the Werner state is given. The influence of external driving field on the finite-time disentanglement of Werner states is discussed. Finally, we present a simple method to control the stationary state entanglement of two qubits. We investigate the concurrence and Bell violation of the Werner or Werner-like states in the presence of collective dephasing. It is shown that the Werner and certain kinds of Werner-like states are robust against the collective dephasing, and some kinds of Werner-like states is fragile and becomes completely disentangled in a finite-time. The threshold time of complete disentanglement of the Werner ...

  15. Genetics Home Reference: ring chromosome 20 syndrome

    Science.gov (United States)

    ... 3 links) Encyclopedia: Chromosome Encyclopedia: Epilepsy Health Topic: Epilepsy Genetic and Rare Diseases Information Center (1 link) Ring chromosome 20 Additional NIH Resources (2 links) National Human Genome Research Institute: Chromosome Abnormalities National Institute of ...

  16. Genetics Home Reference: ring chromosome 14 syndrome

    Science.gov (United States)

    ... Encyclopedia: Chromosome Health Topic: Developmental Disabilities Health Topic: Epilepsy Genetic and Rare Diseases Information Center (1 link) Ring chromosome 14 Additional NIH Resources (2 links) National Human Genome Research Institute: Chromosome Abnormalities National Institute of ...

  17. Bacterial chromosome organization and segregation.

    Science.gov (United States)

    Badrinarayanan, Anjana; Le, Tung B K; Laub, Michael T

    2015-01-01

    If fully stretched out, a typical bacterial chromosome would be nearly 1 mm long, approximately 1,000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length scales, highlighting the functions of various DNA-binding proteins and the impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation. PMID:26566111

  18. ADN et chromosomes

    OpenAIRE

    Hayes, Hélène

    2000-01-01

    Chaque chromosome contient une seule molécule d’ADN. L’ADN déroulé d’un noyau de cellule humaine mesurerait environ 1,8 m : chaque molécule d’ADN est enroulée et compactée en plusieurs étapes, grâce à l’association de différentes protéines, et loge dans le noyau de 6 µm de diamètre. Le degré de condensation de l’ADN est variable selon les régions chromosomiques et les régions les moins condensées sont les plus riches en gènes. L’ADN est composé d’une variété de séquences codantes ou non et ré...

  19. X-Chromosome dosage compensation.

    Science.gov (United States)

    Meyer, Barbara J

    2005-01-01

    In mammals, flies, and worms, sex is determined by distinctive regulatory mechanisms that cause males (XO or XY) and females (XX) to differ in their dose of X chromosomes. In each species, an essential X chromosome-wide process called dosage compensation ensures that somatic cells of either sex express equal levels of X-linked gene products. The strategies used to achieve dosage compensation are diverse, but in all cases, specialized complexes are targeted specifically to the X chromosome(s) of only one sex to regulate transcript levels. In C. elegans, this sex-specific targeting of the dosage compensation complex (DCC) is controlled by the same developmental signal that establishes sex, the ratio of X chromosomes to sets of autosomes (X:A signal). Molecular components of this chromosome counting process have been defined. Following a common step of regulation, sex determination and dosage compensation are controlled by distinct genetic pathways. C. elegans dosage compensation is implemented by a protein complex that binds both X chromosomes of hermaphrodites to reduce transcript levels by one-half. The dosage compensation complex resembles the conserved 13S condensin complex required for both mitotic and meiotic chromosome resolution and condensation, implying the recruitment of ancient proteins to the new task of regulating gene expression. Within each C. elegans somatic cell, one of the DCC components also participates in the separate mitotic/meiotic condensin complex. Other DCC components play pivotal roles in regulating the number and distribution of crossovers during meiosis. The strategy by which C. elegans X chromosomes attract the condensin-like DCC is known. Small, well-dispersed X-recognition elements act as entry sites to recruit the dosage compensation complex and to nucleate spreading of the complex to X regions that lack recruitment sites. In this manner, a repressed chromatin state is spread in cis over short or long distances, thus establishing the

  20. Role of the diet in ontogenesis and induction of chromosomal aberrations in population living in the area exposed to radioactive contamination

    International Nuclear Information System (INIS)

    The objective of this work is to investigate a role of diet in oncogenesis and induction of chromosomal aberrations in fragility sites in the peripheral blood lymphocytes of people in some areas exposed to radionuclides as a result of an accident in the Siberian Chemical Combine (SCP). The purpose of the present study was to investigate the level of aberrations at fragile sites of chromosomes in peripheral blood lymphocytes of population residing area contaminated with radionuclides following an accident at the Siberian Chemical Plant (SCP). We carried out micronucleus test to screen people with radiation-related cytogenetic effects. Of 1246 examined inhabitants of Samus settlement, 148 showed significantly increased frequency of micronucleated erythrocytes and were selected for chromosome analysis as a radiation-exposed group. Additional analysis was carried out for 40 patients with gastric cancer and atrophic gastritis with stage II-III epithelial dysplasia. Eighty six individuals from non-contaminated area were used as a control group. Chromosomal breaks and exchanges occurred preferentially in chromosomes 3 and 6 among radiation-exposed persons and patients. The regions 3pl4-3p25 and 6p23 were damaged most often. There was a tendency towards preferential involvement at q21-q25 of chromosome 6 in patients with gastric cancer and atrophic gastritis. Specific damage at certain chromosome sites was observed in radiation-exposed population as well as in patients with gastric cancer. Most often this damage was located near oncogene loci which could imply that chromosome damage induced by radiation is likely to be a predisposing factor to the expression of oncogenes and malignant transformation of cells in exposed individuals. (author)

  1. Chromatid Painting for Chromosomal Inversion Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the continued development of a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and...

  2. Chromatid Painting for Chromosomal Inversion Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a novel approach to the detection of chromosomal inversions. Transmissible chromosome aberrations (translocations and inversions) have profound genetic...

  3. Mitotic chromosome condensation in vertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Vagnarelli, Paola, E-mail: P.Vagnarelli@ed.ac.uk

    2012-07-15

    Work from several laboratories over the past 10-15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292-301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories-a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307-316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119-1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579-589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different classes

  4. Mitotic chromosome condensation in vertebrates

    International Nuclear Information System (INIS)

    Work from several laboratories over the past 10–15 years has revealed that, within the interphase nucleus, chromosomes are organized into spatially distinct territories [T. Cremer, C. Cremer, Chromosome territories, nuclear architecture and gene regulation in mammalian cells, Nat. Rev. Genet. 2 (2001) 292–301 and T. Cremer, M. Cremer, S. Dietzel, S. Muller, I. Solovei, S. Fakan, Chromosome territories—a functional nuclear landscape, Curr. Opin. Cell Biol. 18 (2006) 307–316]. The overall compaction level and intranuclear location varies as a function of gene density for both entire chromosomes [J.A. Croft, J.M. Bridger, S. Boyle, P. Perry, P. Teague,W.A. Bickmore, Differences in the localization and morphology of chromosomes in the human nucleus, J. Cell Biol. 145 (1999) 1119–1131] and specific chromosomal regions [N.L. Mahy, P.E. Perry, S. Gilchrist, R.A. Baldock, W.A. Bickmore, Spatial organization of active and inactive genes and noncoding DNA within chromosome territories, J. Cell Biol. 157 (2002) 579–589] (Fig. 1A, A'). In prophase, when cyclin B activity reaches a high threshold, chromosome condensation occurs followed by Nuclear Envelope Breakdown (NEB) [1]. At this point vertebrate chromosomes appear as compact structures harboring an attachment point for the spindle microtubules physically recognizable as a primary constriction where the two sister chromatids are held together. The transition from an unshaped interphase chromosome to the highly structured mitotic chromosome (compare Figs. 1A and B) has fascinated researchers for several decades now; however a definite picture of how this process is achieved and regulated is not yet in our hands and it will require more investigation to comprehend the complete process. From a biochemical point of view a vertebrate mitotic chromosomes is composed of DNA, histone proteins (60%) and non-histone proteins (40%) [6]. I will discuss below what is known to date on the contribution of these two different

  5. Uptake and Diagnostic Yield of Chromosomal Microarray in an Australian Child Development Clinic

    Directory of Open Access Journals (Sweden)

    Dylan Mordaunt

    2014-05-01

    Full Text Available Autism is an etiologically heterogeneous developmental disorder for which the range of genetic investigations has expanded considerably over the past decade. Introduction of chromosomal microarray (CMA to clinical practice has expanded the range of conditions which pediatricians are able to detect. This study reviewed the utilization, yield and cost of genetic investigations in a sample of children with pervasive developmental disorders (PDD in an Australian metropolitan child development service. Six hundred and ninety eight patients with PDD were identified from the clinic population. One hundred and ten (15.7% of the clinic population had undergone investigation with chromosomal microarray, 140 (20.0% with karyotype (KT, and 167 (23.9% with Fragile X testing (FRGX. Twelve (10.9% CMA findings were reported, of which seven (6.3% were felt to be the likely cause of the child’s clinical features. Five (3.5% KT findings were reported, of which four (2.9% were felt to be the likely cause of the child’s clinical features. Two patients (1.2% were identified with Fragile X expansions. One fifth of the clinic’s recent PDD population had undergone testing with CMA. CMA appears to have increased the diagnostic yield of the genetic investigation of autism, in line with internationally reported levels. Number needed to test (NNT and cost per incremental diagnosis, were also in line with internationally reported levels.

  6. Scaling Up Family Therapy in Fragile, Conflict-Affected States.

    Science.gov (United States)

    Charlés, Laurie L

    2015-09-01

    This article discusses the design and delivery of two international family therapy-focused mental health and psychosocial support training projects, one in a fragile state and one in a post-conflict state. The training projects took place in Southeast Asia and the Middle East/North Africa. Each was funded, supported, and implemented by local, regional, and international stakeholders, and delivered as part of a broader humanitarian agenda to develop human resource capacity to work with families affected by atrocities. The two examples illustrate how task-shifting/task-sharing and transitional justice approaches were used to inform the scaling-up of professionals involved in each project. They also exemplify how state-citizen phenomena in each location affected the project design and delivery. PMID:25315510

  7. Improved response factor methods for seismic fragility of reactor building

    International Nuclear Information System (INIS)

    A seismic probabilistic risk assessment (PRA) method has been applied to evaluate the safety of nuclear reactor buildings during earthquakes. Improvement was made to two methods (based on linear response and based on non-linear response) of fragility analysis in seismic PRA. The conventional method, which is based on linear response, considers increases of seismic capacity implicitly, using the non-linear behaviour of the structure. We described how to evaluate the capacity increasing factor for the linear response method. Secondly, we proposed a method based on the non-linear response and a stratified two-point estimation method which can efficiently evaluate the variability of non-linear responses. We applied the two method to a PWR-type nuclear reactor building and ascertained that these method are useful and effective. (orig.)

  8. International Transmission of Shocks and Fragility of a Bank Network

    CERN Document Server

    Feng, Xiaobing; Kim, Beom Jun

    2014-01-01

    The weighted and directed network of countries based on the number of overseas banks is analyzed in terms of its fragility to the banking crisis of one country. We use two different models to describe transmission of shocks, one local and the other global. Depending on the original source of the crisis, the overall size of crisis impacts is found to differ country by country. For the two-step local spreading model, it is revealed that the scale of the first impact is determined by the out-strength, the total number of overseas branches of the country at the origin of the crisis, while the second impact becomes more serious if the in-strength at the origin is increased. For the global spreading model, some countries named "triggers" are found to play important roles in shock transmission, and the importance of the feed-forward-loop mechanism is pointed out. We also discuss practical policy implications of the present work.

  9. Eastern Seaboard Electric Grid Fragility Maps Supporting Persistent Availability

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Kimberly A [ORNL; Weigand, Gilbert G [ORNL; Fernandez, Steven J [ORNL

    2012-11-01

    Persistently available power transmission can be disrupted by weather causing power outages with economic and social consequences. This research investigated the effects on the national power grid from a specific weather event, Hurricane Irene, that caused approximately 5.7 million customer power outages along the Eastern Seaboard in August of 2011. The objective was to describe the geographic differences in the grid s vulnerability to these events. Individual factors, such as wind speed or precipitation, were correlated with the number of outages to determine the greatest mechanism of power failure in hopes of strengthening the future power grid. The resulting fragility maps not only depicted 18 counties that were less robust than the design-standard robustness model and three counties that were more robust, but also drew new damage contours with correlated wind speeds and county features.

  10. The quest for targeted therapy in fragile X syndrome.

    Science.gov (United States)

    Zeidler, Shimriet; Hukema, Renate K; Willemsen, Rob

    2015-01-01

    Fragile X syndrome (FXS) is the most common, monogenetic cause of intellectual disability and autism-spectrum disorders. Although there is no effective therapy, greater understanding of disturbed neuronal pathways has introduced options for targeted therapy. But whereas many FXS phenotypes were improved in preclinical studies with drugs targeting these pathways in the FXS mouse model, attempts to translate these animal-model success stories into treatment of patients in clinical trials have been extremely disappointing. Complicating factors, particularly in animal studies, include mouse inbred strains, variability in functional studies between laboratories, publication bias and lack of reliable and objective primary outcome measures in both mice and patients. Possibly most important, however, is one factor that has been little explored: the complexity of the molecular imbalance in FXS and the need to simultaneously target several different disturbed pathways and different cellular compartments. New, well-conceived animal studies should generate more productive approaches in the quest for targeted therapy for FXS. PMID:26294013

  11. Fragile X-associated disorders: a clinical overview.

    Science.gov (United States)

    Gallagher, Anne; Hallahan, Brian

    2012-03-01

    Fragile X Syndrome (FraX) is the most common inherited cause of learning disability worldwide. FraX is an X-linked neuro-developmental disorder involving an unstable trinucleotide repeat expansion of cytosine guanine guanine (CGG). Individuals with the full mutation of FraX have >200 GG repeats with premutation carriers having 55-200 GG repeats. A wide spectrum of physical, behavioural, cognitive, psychiatric and medical problems have been associated with both full mutation and premutation carriers of FraX. In this review, we detail the clinical profile and examine the aetiology, epidemiology, neuropathology, neuroimaging findings and possible management strategies for individuals with both the full mutation and premutation of FraX. PMID:21748281

  12. Resilience in the face of fragile X syndrome.

    Science.gov (United States)

    Fourie, Chantel L; Theron, Linda C

    2012-10-01

    In this article, we communicate transformative findings from a case study on the resilience of a young woman with fragile X syndrome (FXS), a genetic condition involving mental impairment and physical, emotional, and behavioral challenges. We explored the resilience of "Lucy," a spirited 16-year-old North American, using informal interviews with her, formal interviews with significant adults in her life, and observations (visual and anecdotal) over 20 months. In reporting the information-rich case of Lucy, well supported by her ecology to rise above full-mutation FXS, we encourage a positive perspective of living with FXS. Although we recognize the limitations of a single case study, our findings offer tentative, process-oriented insights into resilience in contexts of genetic disability, previously unreported in conjunction with FXS. We concluded that the processes informing Lucy's resilience were partly her responsibility and partly her social ecology's, and comprised intrapersonal agency, unconditional positive acceptance and belonging, and support toward mastery. PMID:22745364

  13. Infant Development in Fragile X Syndrome: Cross-Syndrome Comparisons.

    Science.gov (United States)

    Roberts, Jane E; McCary, Lindsay M; Shinkareva, Svetlana V; Bailey, Donald B

    2016-06-01

    This study examined the developmental profile of male infants with fragile X syndrome (FXS) and its divergence from typical development and development of infants at high risk for autism associated with familial recurrence (ASIBs). Participants included 174 boys ranging in age from 5 to 28 months. Cross-sectional profiles on the Mullen Scales of Early Learning indicated infants with FXS could be differentiated from typically developing infants and ASIBs by 6 months of age. Infants with FXS displayed a trend of lower developmental skills with increasing age that was unique from the typically developing and ASIB groups. Findings suggest infants with FXS present with more significant, pervasive and early emerging delays than previously reported with potentially etiologically distinct developmental profiles. PMID:26864160

  14. Importance of liquid fragility for energy applications of ionic liquids

    Science.gov (United States)

    Sippel, P.; Lunkenheimer, P.; Krohns, S.; Thoms, E.; Loidl, A.

    2015-09-01

    Ionic liquids (ILs) are salts that are liquid close to room temperature. Their possible applications are numerous, e.g., as solvents for green chemistry, in various electrochemical devices, and even for such “exotic” purposes as spinning-liquid mirrors for lunar telescopes. Here we concentrate on their use for new advancements in energy-storage and -conversion devices: Batteries, supercapacitors or fuel cells using ILs as electrolytes could be important building blocks for the sustainable energy supply of tomorrow. Interestingly, ILs show glassy freezing and the universal, but until now only poorly understood dynamic properties of glassy matter, dominate many of their physical properties. We show that the conductivity of ILs, an essential figure of merit for any electrochemical application, depends in a systematic way not only on their glass temperature but also on the so-called fragility, characterizing the non-canonical super-Arrhenius temperature dependence of their ionic mobility.

  15. Viral induction of site-specific chromosome damage.

    Science.gov (United States)

    Fortunato, Elizabeth A; Spector, Deborah H

    2003-01-01

    The advent of advanced cell culture and cytogenetics techniques in the 1950s opened a new avenue for research on the pathogenic interactions between animal viruses and their hosts. Studies of many viruses revealed their ability to nonspecifically induce cytogenetic damage to their host cell's chromosomes. However, only three viruses, the oncogenic adenoviruses, herpes simplex virus (HSV) and human cytomegalovirus (HCMV), have been found to cause non-random, site-specific chromosomal damage. Adenovirus (Ad) type 12 induces fragility at four distinct loci (RNU1, RNU2, RN5S and PSU1) in many different types of human cells. A common feature of these loci is that they contain a repeated array of transcriptionally active genes encoding small structural RNAs. Site-specific induction of breaks also requires the virally encoded E1B protein of M(r) 55000 and the C-terminus of the cellular p53 protein. Analysis of the induction of damage by HSV and HCMV necessitates consideration of several factors, including the strain of virus used, the timing of infection, the type of cell used, and the multiplicity of infection. Both HSV strains 1 and 2 are cytotoxic, although the former seems to be more proficient at inducing damage. At early times post infection, HSV induces breaks and specific uncoiling of the centromeres of chromosomes 1, 9 and 16. This is followed at later times by a more complete severing of all of the chromosomes, termed pulverisation. Damage by HSV requires viral entry and de novo viral protein synthesis, with immediate early viral proteins responsible for the induction of breaks and uncoiling and early gene products (most likely nucleases) involved in the extensive pulverisation seen later. HCMV has been studied primarily in permissive human fibroblasts. Its ability to induce specific damage in chromosome 1 at two loci, 1q21 and 1q42, was only recently revealed as the cells must be in S-phase when they are infected for the breaks to be observed. In contrast to

  16. Systematic review of pharmacological treatments in fragile X syndrome

    Directory of Open Access Journals (Sweden)

    Tejada Maria-Isabel

    2009-10-01

    Full Text Available Abstract Background Fragile X syndrome (FXS is considered the most common cause of inherited mental retardation. Affected people have mental impairment that can include Attention Deficit and/or Hyperactivity Disorder (ADHD, autism disorder, and speech and behavioural disorders. Several pharmacological interventions have been proposed to treat those impairments. Methods Systematic review of the literature and summary of the evidence from clinical controlled trials that compared at least one pharmacological treatment with placebo or other treatment in individuals with diagnosis of FXS syndrome and assessed the efficacy and/or safety of the treatments. Studies were identified by a search of PubMed, EMBASE and the Cochrane Databases using the terms fragile X and treatment. Risk of bias of the studies was assessed by using the Cochrane Collaboration criteria. Results The search identified 276 potential articles and 14 studies satisfied inclusion criteria. Of these, 10 studies on folic acid (9 with crossover design, only 1 of them with good methodological quality and low risk of bias did not find in general significant improvements. A small sample size trial assessed dextroamphetamine and methylphenidate in patients with an additional diagnosis of ADHD and found some improvements in those taking methylphenidate, but the length of follow-up was too short. Two studies on L-acetylcarnitine, showed positive effects and no side effects in patients with an additional diagnosis of ADHD. Finally, one study on patients with an additional diagnosis of autism assessed ampakine compound CX516 and found no significant differences between treatment and placebo. Regarding safety, none of the studies that assessed that area found relevant side effects, but the number of patients included was too small to detect side effects with low incidence. Conclusion Currently there is no robust evidence to support recommendations on pharmacological treatments in patients with

  17. Major osteoporotic fragility fractures: Risk factor updates and societal impact.

    Science.gov (United States)

    Pisani, Paola; Renna, Maria Daniela; Conversano, Francesco; Casciaro, Ernesto; Di Paola, Marco; Quarta, Eugenio; Muratore, Maurizio; Casciaro, Sergio

    2016-03-18

    Osteoporosis is a silent disease without any evidence of disease until a fracture occurs. Approximately 200 million people in the world are affected by osteoporosis and 8.9 million fractures occur each year worldwide. Fractures of the hip are a major public health burden, by means of both social cost and health condition of the elderly because these fractures are one of the main causes of morbidity, impairment, decreased quality of life and mortality in women and men. The aim of this review is to analyze the most important factors related to the enormous impact of osteoporotic fractures on population. Among the most common risk factors, low body mass index; history of fragility fracture, environmental risk, early menopause, smoking, lack of vitamin D, endocrine disorders (for example insulin-dependent diabetes mellitus), use of glucocorticoids, excessive alcohol intake, immobility and others represented the main clinical risk factors associated with augmented risk of fragility fracture. The increasing trend of osteoporosis is accompanied by an underutilization of the available preventive strategies and only a small number of patients at high fracture risk are recognized and successively referred for therapy. This report provides analytic evidences to assess the best practices in osteoporosis management and indications for the adoption of a correct healthcare strategy to significantly reduce the osteoporosis burden. Early diagnosis is the key to resize the impact of osteoporosis on healthcare system. In this context, attention must be focused on the identification of high fracture risk among osteoporotic patients. It is necessary to increase national awareness campaigns across countries in order to reduce the osteoporotic fractures incidence. PMID:27004165

  18. Gametocidal chromosomes enhancing chromosome aberration in common wheat induced by 5-azacytidine.

    Science.gov (United States)

    Su, W-Y; Cong, W-W; Shu, Y-J; Wang, D; Xu, G-H; Guo, C-H

    2013-01-01

    The gametocidal (Gc) chromosome from Aegilops spp induces chromosome mutation, which is introduced into common wheat as a tool of chromosome manipulation for genetic improvement. The Gc chromosome functions similar to a restriction-modification system in bacteria, in which DNA methylation is an important regulator. We treated root tips of wheat carrying Gc chromosomes with the hypomethylation agent 5-azacytidine; chromosome breakage and micronuclei were observed in these root tips. The frequency of aberrations differed in wheat containing different Gc chromosomes, suggesting different functions inducing chromosome breakage. Gc chromosome 3C caused the greatest degree of chromosome aberration, while Gc chromosome 3C(SAT) and 2C caused only slight chromosome aberration. Gc chromosome 3C induced different degrees of chromosome aberration in wheat varieties Triticum aestivum var. Chinese Spring and Norin 26, demonstrating an inhibition function in common wheat. PMID:23884766

  19. Chromosome conservation in squamate reptiles revealed by comparative chromosome painting

    Czech Academy of Sciences Publication Activity Database

    Giovannotti, M.; Pokorná, Martina; Kratochvíl, L.; Caputo, V.; Olmo, E.; Ferguson-Smith, M. A.; Rens, W.

    Manchester : ICCS, 2011. 78-78. [Intarnational Chromosome Conference /18./. 29.08.2011-02.09.2011, Manchester] Institutional research plan: CEZ:AV0Z50450515 Keywords : squamate reptiles Subject RIV: EG - Zoology

  20. Numerous transitions of sex chromosomes in Diptera.

    Directory of Open Access Journals (Sweden)

    Beatriz Vicoso

    2015-04-01

    Full Text Available Many species groups, including mammals and many insects, determine sex using heteromorphic sex chromosomes. Diptera flies, which include the model Drosophila melanogaster, generally have XY sex chromosomes and a conserved karyotype consisting of six chromosomal arms (five large rods and a small dot, but superficially similar karyotypes may conceal the true extent of sex chromosome variation. Here, we use whole-genome analysis in 37 fly species belonging to 22 different families of Diptera and uncover tremendous hidden diversity in sex chromosome karyotypes among flies. We identify over a dozen different sex chromosome configurations, and the small dot chromosome is repeatedly used as the sex chromosome, which presumably reflects the ancestral karyotype of higher Diptera. However, we identify species with undifferentiated sex chromosomes, others in which a different chromosome replaced the dot as a sex chromosome or in which up to three chromosomal elements became incorporated into the sex chromosomes, and others yet with female heterogamety (ZW sex chromosomes. Transcriptome analysis shows that dosage compensation has evolved multiple times in flies, consistently through up-regulation of the single X in males. However, X chromosomes generally show a deficiency of genes with male-biased expression, possibly reflecting sex-specific selective pressures. These species thus provide a rich resource to study sex chromosome biology in a comparative manner and show that similar selective forces have shaped the unique evolution of sex chromosomes in diverse fly taxa.

  1. Increased expression of aphidicolin-induced common fragile sites in Tourette syndrome: The key to understand the genetics of comorbid phenotypes?

    Energy Technology Data Exchange (ETDEWEB)

    Gericke, G.S.; Simonic, I.; Cloete, E.; Becker, P.J. [Univ. of Pretoria (South Africa)

    1996-02-16

    In a comparison of 80 common aphidicolin-induced fragile sites (FS) between 26 DSM-IV Tourette syndrome (TS) and 24 control individuals, the mean of the summed break frequencies following mild aphidicolin pretreatment was significantly higher in TS individuals than in controls (P < 0.001). Other breakpoints encountered during this study, i.e., random breaks, breaks corresponding to rare FS, and breakpoints recorded by others but not listed as common FS according to the Chromosome Coordinating Meeting were listed as category II breakpoints. By using the most significantly different mean FS breakage figures between TS and control individuals, further stepwise discriminant analysis allowed identification of TS individuals from only a few sites in both the common FS and category II breakpoint groups. Future research needs to focus on confirmation of altered common fragile site expression in association with behavioral variation, whether expression of certain discriminatory sites concurs with specific comorbid disorder expression; the nature of the molecular alterations at these FS and the implications of a genomic instability phenotype for the mapping of a primary TS gene or genes. 45 refs., 1 fig., 2 tabs.

  2. COMPARATIVE STUDY OF ERYTHROCYTE FRAGILITY IN DIABETES MELLITUS AND NON DIABETES MELLITUS

    Directory of Open Access Journals (Sweden)

    Harika Priyadarshini K, Asha Latha P, Pradnya S, Ayesha Juhi, Samatha P, Mani Ratnam K

    2015-01-01

    Full Text Available Introduction: The present study has examined the effect of elevated glucose levels on osmotic fragility of erythrocytes. Osmotic fragility determines the rate of hemolysis of erythrocytes. Blood glucose is the sole energy source for erythrocytes. Diabetes mellitus (DM is a metabolic disorder characterized by hyperglycemia and has become a major public health problem globally. Diabeties is the risk factor for osmotic fragility. Aim: the aim of the present study is to describe erythrocyte osmotic fragility changes from type II diabetes to non diabetes. Materials and methods: The osmotic fragility test is a measure of the resistance of erythrocytes to hemolysis by osmotic stress. The study was conducted on (n=60 aged between 50-55 years, case group will include 30 type II diabetes who were randomly selected from outpatients of the Malla Reddy Hospital, Suraram. Control group involves 30 non diabetic individuals. Parameters selected for study are initial hemolysis, complete hemolysis, median corpuscular hemolysis, haemoglobin, haemoglobin A1c, Fasting blood sugar, post prandial blood sugar and respective parameters were compared in both the groups. Results & discussion: In this study when type II diabetics were compared with non diabetic individuals, there was a significant change in osmotic fragility of type II diabetics when compare to non diabetic controls. Conclusion: Hyperglycemia causes structural changes in red cell corpuscles which lead to osmotic stress. Hence, it is necessary to rule out investigations of pathogenic mechanisms induced by red cell fragility to prevent complications of diabetes mellitus.

  3. Familial transmission of a deletion of chromosome 21 derived from a translocation between chromosome 21 and an inverted chromosome 22.

    Science.gov (United States)

    Aviv, H; Lieber, C; Yenamandra, A; Desposito, F

    1997-06-27

    Chromosome analysis of a newborn boy with Down syndrome resulted in the identification of a family with an unusual derivative chromosome 22. The child has 46 chromosomes, including two chromosomes 21, one normal chromosome 22, and a derivative chromosome 22. Giemsa banding and fluorescent in situ hybridization (FISH) studies show that the derivative chromosome is chromosome 22 with evidence of both paracentric and pericentric inversions, joined to the long arm of chromosome 21 from 21q21.2 to qter. The rearrangement results in partial trisomy 21 extending from 21q21.2 to 21q terminus in the patient. The child's mother, brother, maternal aunt, and maternal grandmother are all carriers of the derivative chromosome. All have 45 chromosomes, with one normal chromosome 21, one normal chromosome 22, and the derivative chromosome 22. The rearrangement results in the absence of the short arm, the centromere, and the proximal long arm of chromosome 21 (del 21pter-21q21.2) in carriers. Carriers of the derivative chromosome in this family have normal physical appearance, mild learning disabilities and poor social adjustment. PMID:9182781

  4. Meiosis and chromosome painting of sex chromosome systems in Ceboidea.

    Science.gov (United States)

    Mudry, M D; Rahn, I M; Solari, A J

    2001-06-01

    The identity of the chromosomes involved in the multiple sex system of Alouatta caraya (Aca) and the possible distribution of this system among other Ceboidea were investigated by chromosome painting of mitotic cells from five species and by analysis of meiosis at pachytene in two species. The identity of the autosome #7 (X2) involved in the multiple system of Aca and its breakage points were demonstrated by both meiosis and chromosome painting. These features are identical to those described by Consigliere et al. [1996] in Alouatta seniculus sara (Assa) and Alouatta seniculus arctoidea (Asar). This multiple system was absent in the other four Ceboidea species studied here. However, data from the literature strongly suggest the presence of this multiple in other members of this genus. The presence of this multiple system among several species and subspecies that show high levels of chromosome rearrangements may suggest a special selective value of this multiple. The meiotic features of the sex systems of Aca and Cebus apella paraguayanus (Cap) are strikingly different at pachytene, as the latter system is similar to the sex pair of man and other primates. The relatively large genetic distances between species presently showing this multiple system suggest that its origin is not recent. Other members of the same genus should be investigated at meiosis and by chromosome painting in order to know the extent and distribution of this complex sex-chromosome system. PMID:11376445

  5. Scaling up nutrition in fragile and conflict-affected states: the pivotal role of governance.

    Science.gov (United States)

    Taylor, Sebastian A J; Perez-Ferrer, Carolina; Griffiths, Andrew; Brunner, Eric

    2015-02-01

    Acute and chronic undernutrition undermine conditions for health, stability and socioeconomic development across the developing world. Although fragile and conflict-affected states have some of the highest rates of undernutrition globally, their response to the multilateral 'Scaling Up Nutrition' (SUN) initiative in its first two-year period was ambivalent. The purpose of this research was to investigate factors affecting fragile and conflict-affected states' engagement with SUN, and to examine what differentiated those fragile states that joined SUN in its first phase from those that did not. Drawing on global databases (Unicef, World Bank, UNDP), and qualitative country case studies (Afghanistan, the Democratic Republic of Congo, Sierra Leone, Pakistan and Yemen) we used bivariate logistic regressions and principal component analysis to assess social, economic and political factors across 41 fragile states looking for systematic differences between those that had signed up to SUN before March 2013 (n = 16), and those that had not (n = 25). While prevalence of malnutrition, health system functioning and level of citizen empowerment had little or no impact on a fragile state's likelihood of joining SUN, the quality of governance (QOG) strongly predicted accession. SUN-signatory fragile states scored systematically better on the World Bank's Country Policy and Institutional Assessment (CPIA) and the Worldwide Governance Indicators 'effectiveness of government' indices. We conclude that strengthening governance in fragile states may enhance their engagement with initiatives such as SUN, but also (recognising the potential for endogeneity), that the way aid is structured and delivered in fragile states may be an underlying determinant of whether and how governance in such contexts improves. The research demonstrates that more nuanced analysis of conditions within and among countries classed as 'fragile and conflict-affected' is both possible and necessary if aid

  6. Seismic fragility analyses of nuclear power plant structures based on the recorded earthquake data in Korea

    International Nuclear Information System (INIS)

    This paper briefly introduces an improved method for evaluating seismic fragilities of components of nuclear power plants in Korea. Engineering characteristics of small magnitude earthquake spectra recorded in the Korean peninsula during the last several years are also discussed in this paper. For the purpose of evaluating the effects of the recorded earthquake on the seismic fragilities of Korean nuclear power plant structures, several cases of comparative studies have been performed. The study results show that seismic fragility analysis based on the Newmark's spectra in Korea might over-estimate the seismic capacities of Korean facilities. (author)

  7. Influence of carbide precipitation upon hydrogen fragilization of an AISI 304 steel

    International Nuclear Information System (INIS)

    The present work deals with austenitic stainless steels for a family of steels that is renowned for its high resistance to hydrogen fragilization. Nevertheless, these steels may suffer hydrogen fragilization under severe working conditions. This fact is strongly dependent on many factors -composition, grain size, other phases present, corrosion sensitivity, etc.-. While there are studies that show how intergranular corrosion is influenced by corrosion sensitivity -mainly due to carbide precipitation in grain boundaries-, there are no reports about the effect of the carbide precipitation itself on hydrogen fragilization for these steels. (Author)

  8. Characterization of protonated phospholipids as fragile ions in quadrupole ion trap mass spectrometry

    OpenAIRE

    Garrett, Timothy J.; Merves, Matthew; Yost, Richard A.

    2011-01-01

    Some ions exhibit “ion fragility” in quadrupole ion trap mass spectrometry (QIT-MS) during mass analysis with resonance ejection. In many cases, different ions generated from the same compound exhibit different degrees of ion fragility, with some ions (e.g., the [M+H]+ ion) stable and other ions (e.g., the [M+Na]+ ion) fragile. The ion fragility for quadrupole ion trap (QIT) mass spectrometry (MS) for protonated and sodiated ions of three phospholipids, 1,2-dipalmitoyl-sn-glycero-3-phosphocho...

  9. Non-fragile hybrid guaranteed cost control for a class of uncertain switched linear systems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper focuses on the problem of non-fragile hybrid guaranteed cost control for a class of uncertain switched linear systems. The controller gain to be designed is assumed to have additive gain variations. Based on multiple-Lyapunov function technique, the design of non-fragile hybrid guaranteed cost controllers is derived to make the corresponding closed-loop system asymptotically stable for all admissible uncertainties. Furthermore, a convex optimization approach with LMIs constraints is introduced to select the optimal non-fragile guaranteed cost controllers. Finally, a simulation example illustrates the effectiveness of the proposed approach.

  10. 易损数字水印技术:研究与应用%Fragile Digital Watermarking: Research and Application

    Institute of Scientific and Technical Information of China (English)

    陆唯杰; 陈克非

    2002-01-01

    Recently, digital watermarking techniques for multimedia get fast growth. Digital watermark is some in-formation that will bring no perceptual feeling when embedded in the multimedia data. There are mainly two kind ofwatermark: robust watermark for copyright protection and fragile watermark for data integrity and data authentici-ty. In this paper, we will mainly focus on fragile watermarking. For the purpose of multimedia integrity and authen-ticity protection, we classify current methods into three categories: digital signature techniques, fragile watermarkingtechniques based on Hash function and other fragile digital watermarking techniques. And we discuss each category inthis paper, and especially discuss fragile watermarking in detail. Such a classification will help us understand thefunctions of digital signature and fragile watermarking in data integrity and authenticity protection. And we also dis-cuss some attacks on fragile watermarking and its applications.

  11. Methods for chromosome-specific staining

    Science.gov (United States)

    Gray, Joe W.; Pinkel, Daniel

    1995-01-01

    Methods and compositions for chromosome-specific staining are provided. Compositions comprise heterogenous mixtures of labeled nucleic acid fragments having substantially complementary base sequences to unique sequence regions of the chromosomal DNA for which their associated staining reagent is specific. Methods include methods for making the chromosome-specific staining compositions of the invention, and methods for applying the staining compositions to chromosomes.

  12. Chromosome Architecture and Genome Organization

    OpenAIRE

    Giorgio Bernardi

    2015-01-01

    How the same DNA sequences can function in the three-dimensional architecture of interphase nucleus, fold in the very compact structure of metaphase chromosomes and go precisely back to the original interphase architecture in the following cell cycle remains an unresolved question to this day. The strategy used to address this issue was to analyze the correlations between chromosome architecture and the compositional patterns of DNA sequences spanning a size range from a few hundreds to a few...

  13. Chromosome evolution in Neotropical butterflies

    OpenAIRE

    Saura, Anssi; Von Schoultz, Barbara; Saura, Anja O.; Brown, Keith S., Jr.

    2013-01-01

    We list the chromosome numbers for 65 species of Neotropical Hesperiidae and 104 species or subspecies of Pieridae. In Hesperiidae the tribe Pyrrhopygini have a modal n = 28, Eudaminae and Pyrgini a modal n = 31, while Hesperiinae have n = around 29. Among Pieridae, Coliadinae have a strong modal n = 31 and among Pierinae Anthocharidini are almost fixed for n = 15 while Pierini vary with n = 26 as the most common chromosome number. Dismorphiinae show wide variation. We discuss these results i...

  14. Numerically abnormal chromosome constitutions in humans

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    Chapter 24, discusses numerically abnormal chromosome constitutions in humans. This involves abnormalities of human chromosome number, including polyploidy (when the number of sets of chromosomes increases) and aneuploidy (when the number of individual normal chromosomes changes). Chapter sections discuss the following chromosomal abnormalities: human triploids, imprinting and uniparental disomy, human tetraploids, hydatidiform moles, anomalies caused by chromosomal imbalance, 13 trisomy (D{sub 1} trisomy, Patau syndrome), 21 trisomy (Down syndrome), 18 trisomy syndrome (Edwards syndrome), other autosomal aneuploidy syndromes, and spontaneous abortions. The chapter concludes with remarks on the nonrandom participation of chromosomes in trisomy. 69 refs., 3 figs., 4 tabs.

  15. Chromosome evolution in Neotropical butterflies.

    Science.gov (United States)

    Saura, Anssi; Von Schoultz, Barbara; Saura, Anja O; Brown, Keith S

    2013-06-01

    We list the chromosome numbers for 65 species of Neotropical Hesperiidae and 104 species or subspecies of Pieridae. In Hesperiidae the tribe Pyrrhopygini have a modal n = 28, Eudaminae and Pyrgini a modal n = 31, while Hesperiinae have n = around 29. Among Pieridae, Coliadinae have a strong modal n = 31 and among Pierinae Anthocharidini are almost fixed for n = 15 while Pierini vary with n = 26 as the most common chromosome number. Dismorphiinae show wide variation. We discuss these results in the context of chromosome numbers of over 1400 Neotropical butterfly species and subspecies derived from about 3000 populations published here and in earlier papers of a series. The overall results show that many Neotropical groups are characterized by karyotype instability with several derived modal numbers or none at all, while almost all taxa of Lepidoptera studied from the other parts of the world have one of n = 29-31 as modal numbers. Possibly chromosome number changes become fixed in the course of speciation driven by biotic interactions. Population subdivision and structuring facilitate karyotype change. Factors that stabilize chromosome numbers include hybridization among species sharing the same number, migration, sexual selection and possibly the distribution of chromosomes within the nucleus. PMID:23865963

  16. Chromosome Architecture and Genome Organization

    Science.gov (United States)

    Bernardi, Giorgio

    2015-01-01

    How the same DNA sequences can function in the three-dimensional architecture of interphase nucleus, fold in the very compact structure of metaphase chromosomes and go precisely back to the original interphase architecture in the following cell cycle remains an unresolved question to this day. The strategy used to address this issue was to analyze the correlations between chromosome architecture and the compositional patterns of DNA sequences spanning a size range from a few hundreds to a few thousands Kilobases. This is a critical range that encompasses isochores, interphase chromatin domains and boundaries, and chromosomal bands. The solution rests on the following key points: 1) the transition from the looped domains and sub-domains of interphase chromatin to the 30-nm fiber loops of early prophase chromosomes goes through the unfolding into an extended chromatin structure (probably a 10-nm “beads-on-a-string” structure); 2) the architectural proteins of interphase chromatin, such as CTCF and cohesin sub-units, are retained in mitosis and are part of the discontinuous protein scaffold of mitotic chromosomes; 3) the conservation of the link between architectural proteins and their binding sites on DNA through the cell cycle explains the “mitotic memory” of interphase architecture and the reversibility of the interphase to mitosis process. The results presented here also lead to a general conclusion which concerns the existence of correlations between the isochore organization of the genome and the architecture of chromosomes from interphase to metaphase. PMID:26619076

  17. Evolution of Sex Chromosomes in Insects

    OpenAIRE

    Kaiser, Vera B; Bachtrog, Doris

    2010-01-01

    Sex chromosomes have many unusual features relative to autosomes. Y (or W) chromosomes lack genetic recombination, are male- (female-) limited, and show an abundance of genetically inert heterochromatic DNA but contain few functional genes. X (or Z) chromosomes also show sex-biased transmission (i.e., X chromosomes show female-biased and Z-chromosomes show male-biased inheritance) and are hemizygous in the heterogametic sex. Their unusual ploidy level and pattern of inheritance imply that sex...

  18. Patient perceptions of the path to osteoporosis care following a fragility fracture.

    Science.gov (United States)

    Beaton, Dorcas E; Sujic, Rebeka; McIlroy Beaton, Kristin; Sale, Joanna; Elliot-Gibson, Victoria; Bogoch, Earl R

    2012-12-01

    Coordinator-based osteoporosis (OP) screening programs for fragility-fracture patients in orthopedic environments improve rates of OP testing and care, but there are still gaps in care. The purpose of this study was to understand the process by which patients decided whether to proceed with OP testing or care within these programs. Twenty-four fragility-fracture patients in the OP screening program at a large, urban, university hospital in Canada participated in one of five focus groups. Focus group transcripts were sorted and coded. Links between themes were developed to generate a description of the process leading to successful initiation of OP care after a fragility fracture. To initiate OP testing and care, patients had to both comprehend the link between their fragility fracture and OP, and make an action-oriented appraisal of what action to take. Several modifiable facilitators and barriers influenced the process between screening and undergoing OP testing and initiating treatment. PMID:22923385

  19. [Observations of play and verbal behavior of boys with fragile X syndrome in early childhood].

    Science.gov (United States)

    Sarimski, K

    1999-08-01

    Reports on development and behaviour in boys with fragile-X syndrome support the idea of a characteristic behavioural phenotype in this special population. Preliminary results are presented for 10 boys with fragile-X syndrome in early childhood. Severe mental handicaps and communicative abnormalities are observed less frequently than was expected on the basis of results reported for school-age children or adults. Boys with fragile-X syndrome show goal-directed and cooperative play behaviours in a Montessori play session, but less persistence and organisation than children with normal development or a mental handicap of heterogeneous origin. Results confirmed these behavioural differences as characteristic aspects of a "behavioural phenotype" in children who already in early childhood have fragile-X syndrome. PMID:10478436

  20. Fragile X-Associated Disorders (FXD): A Handbook for Families, Health Care Providers, Counselors, and Educators

    Science.gov (United States)

    ... Genetics of Fragile X-Associated Disorders Cytosine (C) Guanine (G) Methyl Group CGG Start Codon Repeats Promoter ... FXPOI may have inadequate, but not absent, ovarian function such as in POF. FXPOI includes a spectrum ...

  1. The Role of Chain Length in Nonergodicity Factor and Fragility of Polymers

    DEFF Research Database (Denmark)

    Dalle-Ferrie, Cecile; Niss, Kristine; Sokolov, Alexei;

    2010-01-01

    The mechanism that leads to different fragility values upon approaching the glass transition remains a topic of active discussion. Many researchers are trying to find an answer in the properties of the frozen glassy state. Following this approach, we focus here on a previously proposed relationship...... between the fragility of glass-formers and their nonergodicity factor, determined by inelastic X-ray scattering (IXS) in the glass. We extend this molecular liquid study to two model polymers— polystyrene (PS) and polyisobutylene (PIB)—for which we change the molecular weight. Polymers offer the...... opportunity to change the fragility without altering the chemical structure, just by changing the chain length. Thus, we specifically chose PS and PIB because they exhibit opposite dependences of fragility with molecular weight. Our analysis for these two polymers reveals no unique correlation between the...

  2. Chronic γ-irradiation results in increased cell killing and chromosomal aberration with specific breakpoints in fibroblast cell strains derived from non-Hodgkin's lymphoma patients

    International Nuclear Information System (INIS)

    Cultured skin fibroblast cells from 16 NHL (non-Hodgkin's lymphoma) patients and 2 clinically normal subjects were compared for cell survival and chromosomal aberration after chronic γ-irradiation. Fibroblasts from an ataxia telangiectasia (AT) homozygote and an AT heterozygote were used as positive controls. Following irradiation, fibroblasts from all 16 NHL patients showed an increase in both cell death and chromosomal aberration (breaks and rearrangements) compared to normal subjects. The difference in frequency of chromosomal aberration between normals and NHL-patients remained virtually unchanged over a period of 24-72 h post irradiation incubation of cells. Cell cycle analysis by flow cytometry carried out in 1 normal and 1 NHL fibroblast cell strain showed that more cells representing the NHL patient were in G2/M phase compared to the normal at various times of cytogenetic analysis. While the AT homozygote appeared to be the most radiosensitive, the AT heterozygote showed a slightly higher incidence of cell death and chromosomal aberration than the normals. The cellular and chromosomal radiosensitivity of fibroblast cell lines from NHL-patients differed slightly from that of AT heterozygote but clearly occupied an intermediate position between the AT homozygote and the normal subjects. Cells from 3 of the NHL patients showed radiation-induced specific chromosomal breaks involving chromosomes 1, 2, 6, 8, 10 and 11 which correspond to known fragile sites. Such breakpoints associated with increased radiosensitivity may be indicative of predisposition to malignancy in the patients studied. (author). 30 refs., 2 figs., 4 tabs

  3. Phonological Accuracy and Intelligibility in Connected Speech of Boys with Fragile X Syndrome or Down Syndrome

    Science.gov (United States)

    Barnes, Elizabeth; Roberts, Joanne; Long, Steven H.; Martin, Gary E.; Berni, Mary C.; Mandulak, Kerry C.; Sideris, John

    2009-01-01

    Purpose: To compare the phonological accuracy and speech intelligibility of boys with fragile X syndrome with autism spectrum disorder (FXS-ASD), fragile X syndrome only (FXS-O), Down syndrome (DS), and typically developing (TD) boys. Method: Participants were 32 boys with FXS-O (3-14 years), 31 with FXS-ASD (5-15 years), 34 with DS (4-16 years),…

  4. Probabilistic Studies on Seismic Fragility of Different Pipe Sizes Based on Monotonic Experimental Tests

    OpenAIRE

    BuSeog Ju; WooYoung Jung; SungJoong Kim; YongHee Ryu

    2015-01-01

    This paper presents the seismic fragility of piping systems based on monotonic experimental tests. The fragility, conditional probability of failure for a given level of intensity measure, generally used to evaluate the structural safety and indentify the fault tree with respect to seismically induced failures. The nonlinear FE models of threaded T-joint systems based on monotonic experimental results were developed in OpenSees, using the ElasticPPGap material. In order to evaluate the seismi...

  5. Quantitative Profiling of Brain Lipid Raft Proteome in a Mouse Model of Fragile X Syndrome

    OpenAIRE

    Magdalena Kalinowska; Catherine Castillo; Anna Francesconi

    2015-01-01

    Fragile X Syndrome, a leading cause of inherited intellectual disability and autism, arises from transcriptional silencing of the FMR1 gene encoding an RNA-binding protein, Fragile X Mental Retardation Protein (FMRP). FMRP can regulate the expression of approximately 4% of brain transcripts through its role in regulation of mRNA transport, stability and translation, thus providing a molecular rationale for its potential pleiotropic effects on neuronal and brain circuitry function. Several int...

  6. Banking Fragility in Colombia: An Empirical Analysis Based on Balance Sheets

    OpenAIRE

    Ignacio Lozano; Alexander Guarín

    2014-01-01

    In this paper, we study the empirical relationship between credit funding sources and the financial vulnerability of the Colombian banking system. We propose a statistical model to measure and predict banking-fragility episodes associated with credit funding sources classified into retail deposits and wholesale funds. We compute the probability of financial fragility for both the aggregated banking system and the individual banks. Our approach performs a Bayesian averaging of estimated logit ...

  7. The correlation between fragility, density and atomic interaction in glass-forming liquids

    OpenAIRE

    Wang, Lijin; Guan, Pengfei; Wang, W. H.

    2016-01-01

    The fragility, that controls the temperature-dependent viscous properties of liquids as the glass transition is approached, in various glass-forming liquids with different atomic interactions and densities is investigated by molecular dynamic simulations. We show the landscape of fragility in purely repulsive systems can be separated into three regions with qualitatively disparate dynamic behaviors, suggesting that the density plays an unexpected role for understanding the repulsive steepness...

  8. Irreversible injury of isolated adult rat myocytes. Osmotic fragility during metabolic inhibition.

    OpenAIRE

    Ganote, C. E.; Vander Heide, R. S.

    1988-01-01

    Isolated myocytes can be established as a valid model for studying changes in cytoskeletal proteins during the development of irreversible injury only if isolated cells develop lesions similar to those that occur during irreversible injury to intact hearts, specifically osmotic fragility and subsarcolemmal blebs. In the first experiment, isolated cells were irreversibly injured by metabolic inhibition with 5 mM Iodoacetic acid (IAA) and 6 mM amobarbital (Amy). Osmotic fragility of control and...

  9. Benefits of Physical Exercise for Individuals with Fragile X Syndrome in Humans

    OpenAIRE

    Lee, Minkyung; Won, Jinyoung; Lee, Seonghoon; Hong, Yunkyung; Kim, Joo-Heon; Hong, Yonggeun

    2015-01-01

    Fragile X syndrome (FXS) is the most common known genetic cause of autism spectrum disorder, and is also linked to other neurologic and psychiatric disorders. The purpose of this review article is to examine a variety of recent studies on the correlation between physical exercise and autistic behavior in individuals with fragile X syndrome. Additionally, we discuss promising approaches for further investigation of the benefits of physical exercise for autism spectrum disorder (ASD) patients. ...

  10. Neuro-endocrine basis for altered plasma glucose homeostasis in the Fragile X mouse

    OpenAIRE

    El Idrissi Abdeslem; Yan Xin; Sidime Francoise; L’Amoreaux William

    2010-01-01

    Abstract Background The fragile X mouse model shows an increase in seizure susceptibility, indicating an involvement of the GABAergic system via an alteration in cellular excitability. In the brain, we have previously described a reduction in GABAA receptor expression as a likely basis for this susceptibility. In the brains of fragile X mice, this reduction in receptor expression culminates with a concomitant increase in the expression of glutamic acid decarboxylase (GAD), the enzyme responsi...

  11. On the fragility of fractional-order PID controllers for FOPDT processes.

    Science.gov (United States)

    Padula, Fabrizio; Visioli, Antonio

    2016-01-01

    This paper analyzes the fragility issue of fractional-order proportional-integral-derivative controllers applied to integer first-order plus-dead-time processes. In particular, the effects of the variations of the controller parameters on the achieved control system robustness and performance are investigated. Results show that this kind of controllers is more fragile with respect to the standard proportional-integral-derivative controllers and therefore a significant attention should be paid by the user in their tuning. PMID:26639055

  12. Anxiety disorders in fragile X premutation carriers: Preliminary characterization of probands and non-probands

    OpenAIRE

    Cordeiro, Lisa; Abucayan, Floridette; Hagerman, Randi; Tassone, Flora; Hessl, David

    2015-01-01

    A very high proportion of individuals with fragile X syndrome (FXS) (FMR1 full mutation, > 200 CGG repeats) experience clinically significant anxiety. Recent evidence suggests that adult fragile X premutation carriers (55–200 CGG repeats) also are at risk for anxiety disorders, and they demonstrate limbic system alterations mediated by FMRP and/or elevated FMR1 mRNA that may explain this heightened risk. However, less is known about psychiatric symptoms including anxiety among children and ad...

  13. Growth, History, or Institutions? What Explains State Fragility in Sub-Saharan Africa

    OpenAIRE

    Bertocchi, Graziella; Guerzoni, Andrea

    2010-01-01

    We explore the determinants of state fragility in sub-Saharan Africa. Controlling for a wide range of economic, demographic, geographic and institutional regressors, we find that institutions, and in particular the civil liberties index and the number of revolutions, are the main determinants of fragility, even taking into account their potential endogeneity. Economic factors such as income growth and investment display a non robust impact after controlling for omitted variables and reverse c...

  14. Visual motion processing deficits in infants with the fragile X premutation

    OpenAIRE

    Gallego, Pamela K; Burris, Jessica L.; Rivera, Susan M.

    2014-01-01

    Background Fragile X syndrome (FXS) results from a trinucleotide repeat expansion (full mutation >200 cytosine-guanine-guanine (CGG) repeats) in the FMR1 gene, leading to a reduction or absence of the gene’s protein product, fragile X mental retardation protein (FMRP), ultimately causing cognitive and behavioral impairments that are characteristic of the syndrome. In our previous work with infants and toddlers with FXS, we have been able to describe much about their cognitive and visual proce...

  15. Forum on Building Resilience to Fragility in Asia and the Pacific: Proceedings

    OpenAIRE

    Asian Development Bank

    2013-01-01

    This publication captures the presentations and discussions of high-ranking government officials and senior representatives from development partners and civil society organizations during the Forum on Building Resilience to Fragility in Asia and the Pacific, held on 6– 7 June 2013 in Manila. The forum aimed to foster stronger partnerships, support new thinking and innovative engagement, and enhance development efforts to better assist countries with fragile and conflict-affected situations.

  16. Neural progenitor cells from an adult patient with fragile X syndrome

    OpenAIRE

    Nethercott Hubert E; Greco Claudia M; Tassone Flora; Schwartz Philip H; Ziaeian Boback; Hagerman Randi J; Hagerman Paul J

    2005-01-01

    Abstract Background Currently, there is no adequate animal model to study the detailed molecular biochemistry of fragile X syndrome, the leading heritable form of mental impairment. In this study, we sought to establish the use of immature neural cells derived from adult tissues as a novel model of fragile X syndrome that could be used to more fully understand the pathology of this neurogenetic disease. Methods By modifying published methods for the harvest of neural progenitor cells from the...

  17. A Male with Cooccurrence of Down Syndrome and Fragile X Syndrome

    OpenAIRE

    Tovi Anderson; Allison Buterbaugh; Kaitlin Love; Jeannie Visootsak

    2013-01-01

    Down syndrome is the most common identifiable genetic cause of intellectual disability, with a unique physical gestalt that makes diagnosis possible during the newborn period. However, the physical characteristics of Fragile X syndrome are fairly subtle, resulting in the first clinical suspicion often arising from delayed developmental milestones. In addition, maladaptive behavior and autistic-like tendencies, such as hand flapping, poor eye contact, and hand biting, may be noted in Fragile X...

  18. BMP signaling turns up in fragile X syndrome: FMRP represses BMPR2.

    Science.gov (United States)

    Broihier, Heather T

    2016-01-01

    Fragile X syndrome is the most common inherited form of intellectual disability and results from a loss of function of the translational repressor FMRP. In this issue of Science Signaling, Kashima et al find that FMRP binds to and represses a specific isoform of BMPR2, a type II bone morphogenetic protein (BMP) receptor. Reducing signaling through this BMP pathway reverses neuroanatomical defects observed in fragile X models. PMID:27273094

  19. An Investigation of Narrative Ability in Boys with Autism and Fragile X Syndrome

    OpenAIRE

    Hogan-Brown, Abigail L; Losh, Molly; Martin, Gary E.; Mueffelmann, Deborah J.

    2013-01-01

    Whereas pragmatic language difficulties are characteristic of both autism and Fragile X syndrome, it is unclear whether such deficits are qualitatively similar or whether certain skills are differentially affected. This study compared narrative competence in boys with autism, Fragile X syndrome, Down syndrome, and typical development. Results revealed that an interaction between diagnosis and nonverbal mental age predicted narrative microstructure (e.g., complex syntax) but not macrostructure...

  20. Between Development and Security: The European Union, Governance and Fragile States

    OpenAIRE

    Hout, Wil

    2010-01-01

    textabstractThis article focuses on the recent attention in the European Union for fragile states, as expressed, among others, in the European Security Strategy of 2003 and the European Consensus on Development of 2006. It is demonstrated that most understandings of the notion of state fragility concern limited state capacity, the inability of institutions to deal with social and political tensions or problems of state legitimacy. The European Union is no exception to this general trend of se...

  1. Capital and chaos : fragile states, political risk and foreign direct investment

    OpenAIRE

    Graham, Benjamin A. T.

    2012-01-01

    Fragile states are trapped in cycles of poverty, violence, and instability. War and instability deter investment. Low investment retards growth, and lack of growth engenders further conflict and instability. One path out of this equilibrium is for fragile states to succeed in attracting foreign direct investment (FDI) while political risk remains high. My dissertation explores firm-level variation in how investors experience and respond to political risk, identifying types of investors who ar...

  2. Fragile States, Infectious Disease and Health Security: The Case for Timor-Leste

    OpenAIRE

    John M. Quinn; Nelson Martins; Mateus Cunha; Michiyo Higuchi; Dan Murphy; Vladimir Bencko

    2014-01-01

    Timor-Leste is a very young and developing nation state. Endemic infectious disease and weakened health security coupled with its growing and inclusive public institutions keep Timor-Leste fragile and in transition on the spectrum of state stability. The objective here is to systematically review Timor-Leste's state and public health successes, showing how a fragile state can consistently improve its status on the continuum of stability and improve health security for the population. The case...

  3. Möbius molecules and fragile Mott insulators

    Science.gov (United States)

    Muechler, Lukas; Maciejko, Joseph; Neupert, Titus; Car, Roberto

    2015-03-01

    Motivated by the concept of Möbius aromatics in organic chemistry, we extend the recently introduced concept of fragile Mott insulators (FMI) to ring-shaped molecules with repulsive Hubbard interactions threaded by a half-quantum of magnetic flux (hc / 2 e). In this context, a FMI is the insulating ground state of a finite-size molecule that cannot be adiabatically connected to a single Slater determinant, i.e., to a band insulator, provided that time-reversal and lattice translation symmetries are preserved. Based on exact numerical diagonalization for finite Hubbard interaction strength U and existing Bethe-ansatz studies of the one-dimensional Hubbard model in the large- U limit, we establish a duality between Hubbard molecules with 4 n and 4 n + 2 sites, with n integer. A molecule with 4 n sites is an FMI in the absence of flux but becomes a band insulator in the presence of a half-quantum of flux, while a molecule with 4 n + 2 sites is a band insulator in the absence of flux but becomes an FMI in the presence of a half-quantum of flux. Including next-nearest-neighbor-hoppings gives rise to new FMI states that belong to multidimensional irreducible representations of the molecular point group, giving rise to a rich phase diagram. Reference: arXiv:1409.6732

  4. Fragile Social Norms: (Un Sustainable Exploration of Forest Products

    Directory of Open Access Journals (Sweden)

    Decio Zylbersztajn

    2010-01-01

    Full Text Available The exhaustion of natural resources is a central problem in the international agenda. The particular case of Amazon forest is at the top on the international environmental debate. Two related problems are keys to be considered in the discussion of sustainable development in this region. First the predatory use of the natural resources of the forest mainly timber and genetic resources. Second the recognition of the existence of a population of around 20 million inhabitants in the region defined as “Legal Amazon Area”, aiming the improvement on the living conditions, enhancement of income level and acceleration of development. How to match both objectives is a puzzle faced by the present generation.The region is populated by initiatives of international non-governmental-organizations, most of them carrying good intentions but lacking the necessary knowledge on local formal and informal institutions to find ways to reach sustainable development. The result is the accelerated process of natural resources depletion, and social disorganization. The case of the production of Brazilian Nuts stands as a corollary of the lack of an institutional structure of property rights that does not provide incentives for sustainable development. The opposite effect is being observed as a result of the fragility of observable institutional arrangements.The case provides the counterfactual for the analysis of Ostrom (1990; 2008, where she presents virtuous cases of sustainable exploration of natural resources, mostly based on informal but solid institutions.

  5. Bone composition: relationship to bone fragility and antiosteoporotic drug effects.

    Science.gov (United States)

    Boskey, Adele L

    2013-01-01

    The composition of a bone can be described in terms of the mineral phase, hydroxyapatite, the organic phase, which consists of collagen type I, noncollagenous proteins, other components and water. The relative proportions of these various components vary with age, site, gender, disease and treatment. Any drug therapy could change the composition of a bone. This review, however, will only address those pharmaceuticals used to treat or prevent diseases of bone: fragility fractures in particular, and the way they can alter the composition. As bone is a heterogeneous tissue, its composition must be discussed in terms of the chemical makeup, properties of its chemical constituents and their distributions in the ever-changing bone matrix. Emphasis, in this review, is placed on changes in composition as a function of age and various diseases of bone, particularly osteoporosis. It is suggested that while some of the antiosteoporotic drugs can and do modify composition, their positive effects on bone strength may be balanced by negative ones. PMID:24501681

  6. Gliomas and the vascular fragility of the blood brain barrier

    Science.gov (United States)

    Dubois, Luiz Gustavo; Campanati, Loraine; Righy, Cassia; D’Andrea-Meira, Isabella; Spohr, Tania Cristina Leite de Sampaio e; Porto-Carreiro, Isabel; Pereira, Claudia Maria; Balça-Silva, Joana; Kahn, Suzana Assad; DosSantos, Marcos F.; Oliveira, Marcela de Almeida Rabello; Ximenes-da-Silva, Adriana; Lopes, Maria Celeste; Faveret, Eduardo; Gasparetto, Emerson Leandro; Moura-Neto, Vivaldo

    2014-01-01

    Astrocytes, members of the glial family, interact through the exchange of soluble factors or by directly contacting neurons and other brain cells, such as microglia and endothelial cells. Astrocytic projections interact with vessels and act as additional elements of the Blood Brain Barrier (BBB). By mechanisms not fully understood, astrocytes can undergo oncogenic transformation and give rise to gliomas. The tumors take advantage of the BBB to ensure survival and continuous growth. A glioma can develop into a very aggressive tumor, the glioblastoma (GBM), characterized by a highly heterogeneous cell population (including tumor stem cells), extensive proliferation and migration. Nevertheless, gliomas can also give rise to slow growing tumors and in both cases, the afflux of blood, via BBB is crucial. Glioma cells migrate to different regions of the brain guided by the extension of blood vessels, colonizing the healthy adjacent tissue. In the clinical context, GBM can lead to tumor-derived seizures, which represent a challenge to patients and clinicians, since drugs used for its treatment must be able to cross the BBB. Uncontrolled and fast growth also leads to the disruption of the chimeric and fragile vessels in the tumor mass resulting in peritumoral edema. Although hormonal therapy is currently used to control the edema, it is not always efficient. In this review we comment the points cited above, considering the importance of the BBB and the concerns that arise when this barrier is affected. PMID:25565956

  7. Matrix Metalloproteinases and Minocycline: Therapeutic Avenues for Fragile X Syndrome

    Directory of Open Access Journals (Sweden)

    Saul S. Siller

    2012-01-01

    Full Text Available Fragile X syndrome (FXS is the most common known genetic form of intellectual disability and autism spectrum disorders. FXS patients suffer a broad range of other neurological symptoms, including hyperactivity, disrupted circadian activity cycles, obsessive-compulsive behavior, and childhood seizures. The high incidence and devastating effects of this disease state make finding effective pharmacological treatments imperative. Recently, reports in both mouse and Drosophila FXS disease models have indicated that the tetracycline derivative minocycline may hold great therapeutic promise for FXS patients. Both models strongly suggest that minocycline acts on the FXS disease state via inhibition of matrix metalloproteinases (MMPs, a class of zinc-dependent extracellular proteases important in tissue remodeling and cell-cell signaling. Recent FXS clinical trials indicate that minocycline may be effective in treating human patients. In this paper, we summarize the recent studies in Drosophila and mouse FXS disease models and human FXS patients, which indicate that minocycline may be an effective FXS therapeutic treatment, and discuss the data forming the basis for the proposed minocycline mechanism of action as an MMP inhibitor.

  8. Probabilistic Risk Assessment: Piping Fragility due to Earthquake Fault Mechanisms

    Directory of Open Access Journals (Sweden)

    Bu Seog Ju

    2015-01-01

    Full Text Available A lifeline system, serving as an energy-supply system, is an essential component of urban infrastructure. In a hospital, for example, the piping system supplies elements essential for hospital operations, such as water and fire-suppression foam. Such nonstructural components, especially piping systems and their subcomponents, must remain operational and functional during earthquake-induced fires. But the behavior of piping systems as subjected to seismic ground motions is very complex, owing particularly to the nonlinearity affected by the existence of many connections such as T-joints and elbows. The present study carried out a probabilistic risk assessment on a hospital fire-protection piping system’s acceleration-sensitive 2-inch T-joint sprinkler components under seismic ground motions. Specifically, the system’s seismic capacity, using an experimental-test-based nonlinear finite element (FE model, was evaluated for the probability of failure under different earthquake-fault mechanisms including normal fault, reverse fault, strike-slip fault, and near-source ground motions. It was observed that the probabilistic failure of the T-joint of the fire-protection piping system varied significantly according to the fault mechanisms. The normal-fault mechanism led to a higher probability of system failure at locations 1 and 2. The strike-slip fault mechanism, contrastingly, affected the lowest fragility of the piping system at a higher PGA.

  9. Men's economic status and marital transitions of fragile families

    Directory of Open Access Journals (Sweden)

    Sharon Sassler

    2014-01-01

    Full Text Available Background: Men's ability to fill the provider role remains a consistent requirement for marriage across the class spectrum and cross-nationally. Fiscal concerns appear less salient for transitions to parenthood or to informal unions such as cohabitation. Objective: This paper evaluates whether marital expectations and marital transitions of new mothers are associated with the economic characteristics of father. Methods: Analyses are based on observed and imputed data on fathers from the first two waves of the Fragile Families and Child Well-Being Study. Logistic regression models assess factors predicting mothers' initial expectations of marrying their baby's father, and transitions into marital unions by the second interview. Results: Most women expect to marry their baby's father, although estimates are lower when men's data are repaired by imputation. Multivariate analyses find mother's marital expectations are most strongly associated with men's educational attainment, but not with men's earnings at the child's birth. Transitions to marriage are positively associated with men's earnings levels, although estimates are considerably lower than previously reported thresholds. Furthermore, the odds of marrying do not increase monotonically as men's income level rises once missing data are imputed. Conclusions: Theories regarding prerequisites for marriage must better account for growing heterogeneity in the unmarried population. Standard economic predictors of marriage for the overall population are less applicable for this sample of new parents. Ultimately, this study highlights the importance of including information on missing fathers. Excluding them may produce misleading statistical associations between men's economic measures and women's marriage.

  10. A Tsunami Fragility Assessment for Nuclear Power Plants in Korea

    International Nuclear Information System (INIS)

    Although Tsunami events were defined as an external event in 'PRA Procedure Guide (NUREG/CR- 2300)'after 1982, a Tsunami event was not considered in a design and construction of NPP before the Sumatra earthquake in 2004. But the Madras Atomic Power Station, a commercial nuclear power plant owned and operated by the Nuclear Power Corporation of India Limited (NPCIL), and located near Chennai, India, was affected by the tsunami generated by the 2004 Sumatra earthquake (USNRC 2008). The condenser cooling pumps of Unit 2 of the installation were affected due to flooding of the pump house and subsequent submergence of the seawater pumps by tsunami waves. The turbine was tripped and the reactor shut down. The unit was brought to a cold-shutdown state, and the shutdown-cooling systems were reported as operating safely. After this event, Tsunami hazards were considered as one of the major natural disasters which can affect the safety of Nuclear Power Plants. The IAEA performed an Extrabudgetary project for Tsunami Hazard Assessment and finally an International Seismic Safety Center (ISSC) established in IAEA for protection from natural disasters like earthquake, tsunami etc. For this reason, a tsunami hazard assessment method determined in this study. At first, a procedure for tsunami hazard assessment method was established, and second target equipment and structures for investigation of Tsunami Hazard assessment were selected. Finally, a sample fragility calculation was performed for one of equipment in Nuclear Power Plant

  11. Gliomas and the vascular fragility of the blood brain barrier

    Directory of Open Access Journals (Sweden)

    Luiz Gustavo eDubois

    2014-12-01

    Full Text Available Astrocytes, members of the glial family, interact through the exchange of soluble factors or by directly contacting neurons and other brain cells, such as microglia and endothelial cells. Astrocytic projections interact with vessels and act as additional elements of the Blood Brain Barrier (BBB. By mechanisms not fully understood, astrocytes can undergo oncogenic transformation and give rise to gliomas. The tumors take advantage of the BBB to ensure survival and continuous growth. A glioma can develop into a very aggressive tumor, the glioblastoma (GBM, characterized by a highly heterogeneous cell population (including tumor stem cells, extensive proliferation and migration. Nevertheless, gliomas can also give rise to slow growing tumors and in both cases, the afflux of blood, via BBB is crucial. Glioma cells migrate to different regions of the brain guided by the extension of blood vessels, colonizing the healthy adjacent tissue. In the clinical context, GBM can lead to tumor-derived seizures, which represent a challenge to patients and clinicians, since drugs used for its treatment must be able to cross the BBB. Uncontrolled and fast growth also leads to the disruption of the chimeric and fragile vessels in the tumor mass resulting in peritumoral edema. Although hormonal therapy is currently used to control the edema, it is not always efficient. In this review we comment the points cited above, considering the importance of the blood brain barrier and the concerns that arise when this barrier is affected.

  12. Fragile DNA repair mechanism reduces ageing in multicellular model.

    Directory of Open Access Journals (Sweden)

    Kristian Moss Bendtsen

    Full Text Available DNA damages, as well as mutations, increase with age. It is believed that these result from increased genotoxic stress and decreased capacity for DNA repair. The two causes are not independent, DNA damage can, for example, through mutations, compromise the capacity for DNA repair, which in turn increases the amount of unrepaired DNA damage. Despite this vicious circle, we ask, can cells maintain a high DNA repair capacity for some time or is repair capacity bound to continuously decline with age? We here present a simple mathematical model for ageing in multicellular systems where cells subjected to DNA damage can undergo full repair, go apoptotic, or accumulate mutations thus reducing DNA repair capacity. Our model predicts that at the tissue level repair rate does not continuously decline with age, but instead has a characteristic extended period of high and non-declining DNA repair capacity, followed by a rapid decline. Furthermore, the time of high functionality increases, and consequently slows down the ageing process, if the DNA repair mechanism itself is vulnerable to DNA damages. Although counterintuitive at first glance, a fragile repair mechanism allows for a faster removal of compromised cells, thus freeing the space for healthy peers. This finding might be a first step toward understanding why a mutation in single DNA repair protein (e.g. Wrn or Blm is not buffered by other repair proteins and therefore, leads to severe ageing disorders.

  13. Backbone Fragility and the Local Search Cost Peak

    CERN Document Server

    Gent, I P; Smaill, A; 10.1613/jair.711

    2011-01-01

    The local search algorithm WSat is one of the most successful algorithms for solving the satisfiability (SAT) problem. It is notably effective at solving hard Random 3-SAT instances near the so-called `satisfiability threshold', but still shows a peak in search cost near the threshold and large variations in cost over different instances. We make a number of significant contributions to the analysis of WSat on high-cost random instances, using the recently-introduced concept of the backbone of a SAT instance. The backbone is the set of literals which are entailed by an instance. We find that the number of solutions predicts the cost well for small-backbone instances but is much less relevant for the large-backbone instances which appear near the threshold and dominate in the overconstrained region. We show a very strong correlation between search cost and the Hamming distance to the nearest solution early in WSat's search. This pattern leads us to introduce a measure of the backbone fragility of an instance, ...

  14. Probabilistic Studies on Seismic Fragility of Different Pipe Sizes Based on Monotonic Experimental Tests

    Directory of Open Access Journals (Sweden)

    BuSeog Ju

    2015-08-01

    Full Text Available This paper presents the seismic fragility of piping systems based on monotonic experimental tests. The fragility, conditional probability of failure for a given level of intensity measure, generally used to evaluate the structural safety and indentify the fault tree with respect to seismically induced failures. The nonlinear FE models of threaded T-joint systems based on monotonic experimental results were developed in OpenSees, using the ElasticPPGap material. In order to evaluate the seismic fragility of Tjoint piping systems, 1-inch and 2-inch threaded T-joint systems, were incorporated with main hospital piping system, and multiple nonlinear time history analyses related to Monte Carlo simulation were conducted. Consequently, seismic fragility of piping system at 1-inch and 2-inch threaded T-joint connections corresponding to ductility level was developed. It was interesting to observe that 2-inch threaded T-joint was more fragile rather than 1-inch threaded T-joint, based on the nonlinear FE model by monotonic tests and also location 1 was more fragile rather than location 2 for both 1-inch and 2-inch T-joint.

  15. Seismic fragility parameter that minimize response uncertainty of seismic isolated NPP

    International Nuclear Information System (INIS)

    In seismic probabilistic safety assessment (PSA), it is important that one obtains reasonable fragility of components. When a seismic isolation system is installed in a nuclear power plant, it was demonstrated that a good independent variable in fragility (fragility parameter) is required to achieve a less response uncertainty (variation) in the previous studies. In this paper, a quantitative comparison of response variations is carried out to select a good fragility parameter in case of a seismic isolation system. Structural analyses based on a lumped mass model are carried out and response variations are calculated in terms of an independent variable of peak ground velocity (PGV), velocity spectrum which period corresponds to a natural period of a seismic isolation layer (Sv(np)) and peak ground acceleration (PGA). In the analyses, a laminated rubber and an oil damper are applied for the isolation system, which is planned to be installed in Japan Sodium-cooled Fast Reactor (JSFR). As a result, it is concluded that there are no large differences of an appropriateness for fragility parameter between PGV and Sv(np), in case of a high damping system. On the other hand, in case of a low damping system, Sv(np) is the most appropriate fragility parameter. (author)

  16. Component Fragility Research Program: Phase 1, Demonstration tests: Volume 1, Summary report

    International Nuclear Information System (INIS)

    This report describes tests performed in Phase I of the NRC Component Fragility Research Program. The purpose of these tests was to demonstrate procedures for characterizing the seismic fragility of a selected component, investigating how various parameters affect fragility, and finally using test data to develop practical fragility descriptions suitable for application in probabilistic risk assessments. A three-column motor control center housing motor controllers of various types and sizes as well as relays of different types and manufacturers was subjected to seismic input motions up to 2.5g zero period acceleration. To investigate the effect of base flexibility on the structural behavior of the MCC and on the functional behavior of the electrical devices, multiple tests were performed on each of four mounting configurations: four bolts per column with top bracking, four bolts per column with no top brace, four bolts per column with internal diagonal bracking, and two bolts per column with no top or internal bracking. Device fragility was characterized by contact chatter correlated to local in-cabinet response at the device location. Seismic capacities were developed for each device on the basis of local input motion required to cause chatter; these results were then applied to develop probabilistic fragility curves for each type of device, including estimates of the ''high-confidence low probability of failure'' capacity of each

  17. Fragility analysis methodology for degraded structures and passive components in nuclear power plantsIllustrated using a condensate storage tank

    International Nuclear Information System (INIS)

    This report describes the seismic fragility capacity for a condensate storage tank with various degradation scenarios. The conservative deterministic failure margin method has been utilized for the undegraded case and has been modified to accommodate the degraded cases. A total of five seismic fragility analysis cases have been described: (1) undegraded case, (2) degraded stainless tank shell, (3) degraded anchor bolts, (4) anchorage concrete cracking, and (5) a perfect correlation of the three degradation scenarios. Insights from these fragility analyses are also presented. An overview of the methods for seismic fragility analysis and generic approaches to incorporate time-dependent degradation models into a fragility analysis is presented. Fundamental concepts of seismic fragility analysis are summarized to facilitate discussions in later sections. The seismic fragility analysis of the undegraded CST, which is assumed to have all of its components in design condition, is described. The subject CST was located in an operating Korean NPP. The baseline fragility capacity of the CST is calculated and the basic procedure of seismic fragility analysis is established. This report presents the results and insights of the seismic fragility analysis of the CST under various postulated degradation scenarios

  18. Retrospective dosimetry using chromosome painting

    International Nuclear Information System (INIS)

    Chromosome aberration frequency measured in peripheral lymphocytes of persons exposed to ionizing radiation has been used since 1960s for dose assessment. Suspected overexposure is usually evaluated by the frequency of dicentrics and centric rings using an appropriate in vitro calibration curve. However, these chromosome aberrations are unstable with time after exposure and dose reconstruction may encounter uncertainties when the time between the exposure and the analysis is considerable or even unknown. It appears that translocations persist with time after exposure and may be used as an indication of acute past overexposures. Moreover, they appear to accumulate the cytogenetical information, which correlates with the dose received under fractionated, chronic or even occupational exposure conditions. Translocations may be detected using G-banding, which allows to score the total amount of radiation induced translocations but it is a time consuming method, or by Chromosome Painting, a method base on the Fluorescence in situ Hybridization (FISH) technique, painting only some chromosome pairs with specific whole chromosome probes and then extrapolating the observed translocation frequencies to the full genome. The latter method allows a faster aberration scoring than G-banding and appears to be the most promissory tool for biodosimetry, particularly when it is necessary to assess low doses and consequently to score a large number of metaphases, e.g. radiation workers exposed within dose limits. As with the unstable chromosome aberration, it is necessary an in vitro calibration curve based on the frequency of stable chromosome aberrations to assess doses. Our laboratory performed calibration curves for Co60 γ-rays based on the frequencies of unstable (dicentrics and centric rings detected by conventional Giemsa staining) and stable chromosome aberrations (translocations and inversions, detected by G-banding). In order to minimize the interlaboratory variability, we

  19. The Reduction of Chromosome Number in Meiosis Is Determined by Properties Built into the Chromosomes

    OpenAIRE

    Paliulis, Leocadia V.; Nicklas, R. Bruce

    2000-01-01

    In meiosis I, two chromatids move to each spindle pole. Then, in meiosis II, the two are distributed, one to each future gamete. This requires that meiosis I chromosomes attach to the spindle differently than meiosis II chromosomes and that they regulate chromosome cohesion differently. We investigated whether the information that dictates the division type of the chromosome comes from the whole cell, the spindle, or the chromosome itself. Also, we determined when chromosomes can switch from ...

  20. Chromosome segregation in plant meiosis

    Directory of Open Access Journals (Sweden)

    Linda eZamariola

    2014-06-01

    Full Text Available Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring throughout the two meiotic cell divisions. Synapsis and recombination ensure the establishment of chiasmata that hold homologous chromosomes together allowing their correct segregation in the first meiotic division, which is also tightly regulated by cell-cycle dependent release of cohesin and monopolar attachment of sister kinetochores to microtubules. In meiosis II, bi-orientation of sister kinetochores and proper spindle orientation correctly segregate chromosomes in four haploid cells. Checkpoint mechanisms acting at kinetochores control the accuracy of kinetochore-microtubule attachment, thus ensuring the completion of segregation. Here we review the current knowledge on the processes taking place during chromosome segregation in plant meiosis, focusing on the characterization of the molecular factors involved.

  1. Radiation-induced chromosomal instability

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S. [GSI, Biophysics, Darmstadt (Germany)

    1999-03-01

    Recent studies on radiation-induced chromosomal instability in the progeny of exposed mammalian cells were briefly described as well as other related studies. For the analysis of chromosomal damage in clones, cells were seeded directly after exposure in cell well-dish to form single cell clones and post-irradiation chromosome aberrations were scored. Both exposure to isoeffective doses of X-ray or 270 MeV/u C-ions (13 keV/{mu}m) increased the number of clones with abnormal karyotype and the increase was similar for X-ray and for C-ions. Meanwhile, in the progeny of cells for mass cultures, there was no indication of a delayed expression of chromosomal damage up to 40 population doublings after the exposure. A high number of aberrant cells were only observed directly after exposure to 10.7 MeV/u O-ions, i.e. in the first cycle cells and decreased with subsequent cell divisions. The reason for these differences in the radiation-induced chromosomal instability between clonal isolates and mass culture has not been clarified. Recent studies indicated that genomic instability occurs at a high frequency in the progeny of cells irradiated with both sparsely and densely ionizing radiation. Such genomic instability is thought likely to increase the risk of carcinogenesis, but more data are required for a well understanding of the health risks resulting from radiation-induced delayed instability. (M.N.)

  2. Dean flow fractionation of chromosomes

    Science.gov (United States)

    Hockin, Matt; Sant, Himanshu J.; Capecchi, Mario; Gale, Bruce K.

    2016-03-01

    Efforts to transfer intact mammalian chromosomes between cells have been attempted for more than 50 years with the consistent result being transfer of sub unit length pieces regardless of method. Inertial microfluidics is a new field that has shown much promise in addressing the fractionation of particles in the 2-20 μm size range (with unknown limits) and separations are based upon particles being carried by curving confined flows (within a spiral shaped, often rectangular flow chamber) and migrating to stable "equilibrium" positions of varying distance from a chamber wall depending on the balance of dean and lift forces. We fabricated spiral channels for inertial microfluidic separations using a standard soft lithography process. The concentration of chromosomes, small contaminant DNA and large cell debris in each outlets were evaluated using microscope (60X) and a flow cytometer. Using Dean Flow Fractionation, we were able to focus 4.5 times more chromosomes in outlet 2 compared to outlet 4 where most of the large debris is found. We recover 16% of the chromosomes in outlet #1- 50% in 2, 23% in 3 and 11% in 4. It should be noted that these estimates of recovery do not capture one piece of information- it actually may be that the chromosomes at each outlet are physically different and work needs to be done to verify this potential.

  3. Chromosomal rearrangement interferes with meiotic X chromosome inactivation

    Czech Academy of Sciences Publication Activity Database

    Homolka, David; Ivánek, Robert; Čapková, Jana; Jansa, Petr; Forejt, Jiří

    2007-01-01

    Roč. 17, č. 10 (2007), s. 1431-1437. ISSN 1088-9051 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GA301/06/1334; GA ČR GA301/07/1383 Grant ostatní: Howard Hughes Medical Institute(US) HHMI 55000306 Institutional research plan: CEZ:AV0Z50520514 Keywords : chromosomal translocations * meiotic X chromosome inactivation * spermatogenesis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 11.224, year: 2007

  4. Escape Artists of the X Chromosome.

    Science.gov (United States)

    Balaton, Bradley P; Brown, Carolyn J

    2016-06-01

    Inactivation of one X chromosome in mammalian females achieves dosage compensation between XX females and XY males; however, over 15% of human X-linked genes continue to be expressed from the inactive X chromosome. New genomic methodologies have improved our identification and characterization of these escape genes, revealing the importance of DNA sequence, chromatin structure, and chromosome ultrastructure in regulating expression from an otherwise inactive chromosome. Study of these exceptions to the rule of silencing highlights the interconnectedness of chromatin and chromosome structure in X-chromosome inactivation (XCI). Recent advances also demonstrate the importance of these genes in sexually dimorphic disease risk, particularly cancer. PMID:27103486

  5. Adults with Chromosome 18 Abnormalities.

    Science.gov (United States)

    Soileau, Bridgette; Hasi, Minire; Sebold, Courtney; Hill, Annice; O'Donnell, Louise; Hale, Daniel E; Cody, Jannine D

    2015-08-01

    The identification of an underlying chromosome abnormality frequently marks the endpoint of a diagnostic odyssey. However, families are frequently left with more questions than answers as they consider their child's future. In the case of rare chromosome conditions, a lack of longitudinal data often makes it difficult to provide anticipatory guidance to these families. The objective of this study is to describe the lifespan, educational attainment, living situation, and behavioral phenotype of adults with chromosome 18 abnormalities. The Chromosome 18 Clinical Research Center has enrolled 483 individuals with one of the following conditions: 18q-, 18p-, Tetrasomy 18p, and Ring 18. As a part of the ongoing longitudinal study, we collect data on living arrangements, educational level attained, and employment status as well as data on executive functioning and behavioral skills on an annual basis. Within our cohort, 28 of the 483 participants have died, the majority of whom have deletions encompassing the TCF4 gene or who have unbalanced rearrangement involving other chromosomes. Data regarding the cause of and age at death are presented. We also report on the living situation, educational attainment, and behavioral phenotype of the 151 participants over the age of 18. In general, educational level is higher for people with all these conditions than implied by the early literature, including some that received post-high school education. In addition, some individuals are able to live independently, though at this point they represent a minority of patients. Data on executive function and behavioral phenotype are also presented. Taken together, these data provide insight into the long-term outcome for individuals with a chromosome 18 condition. This information is critical in counseling families on the range of potential outcomes for their child. PMID:25403900

  6. Widespread non-central nervous system organ pathology in fragile X premutation carriers with fragile X-associated tremor/ataxia syndrome and CGG knock-in mice

    NARCIS (Netherlands)

    Hunsaker, M.R.; Greco, C.M.; Spath, M.A.; Smits, A.P.T.; Navarro, C.S.; Tassone, F.; Kros, J.M.; Severijnen, L.A.; Berry-Kravis, E.M.; Berman, R.F.; Hagerman, P.J.; Willemsen, R.; Hagerman, R.J.; Hukema, R.K.

    2011-01-01

    Fragile X-associated tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder generally presenting with intention tremor and gait ataxia, but with a growing list of co-morbid medical conditions including hypothyroidism, hypertension, peripheral neuropathy, and cognitive decline. T

  7. 53BP1 nuclear bodies form around DNA lesions generated by mitotic transmission of chromosomes under replication stress

    DEFF Research Database (Denmark)

    Lukas, Claudia; Savic, Velibor; Bekker-Jensen, Simon;

    2011-01-01

    Completion of genome duplication is challenged by structural and topological barriers that impede progression of replication forks. Although this can seriously undermine genome integrity, the fate of DNA with unresolved replication intermediates is not known. Here, we show that mild replication...... bodies shield chromosomal fragile sites sequestered in these compartments against erosion. Together, these data indicate that restoration of DNA or chromatin integrity at loci prone to replication problems requires mitotic transmission to the next cell generations....... increases after genetic ablation of BLM, a DNA helicase associated with dissolution of entangled DNA. Conversely, 53BP1 nuclear bodies are partially suppressed by knocking down SMC2, a condensin subunit required for mechanical stability of mitotic chromosomes. Finally, we provide evidence that 53BP1 nuclear...

  8. Making chromosome abnormalities treatable conditions.

    Science.gov (United States)

    Cody, Jannine DeMars; Hale, Daniel Esten

    2015-09-01

    Individuals affected by the classic chromosome deletion syndromes which were first identified at the beginning of the genetic age, are now positioned to benefit from genomic advances. This issue highlights five of these conditions (4p-, 5p-, 11q-, 18p-, and 18q-). It focuses on the increased in understanding of the molecular underpinnings and envisions how these can be transformed into effective treatments. While it is scientifically exciting to see the phenotypic manifestations of hemizygosity being increasingly understood at the molecular and cellular level, it is even more amazing to consider that we are now on the road to making chromosome abnormalities treatable conditions. PMID:26351122

  9. Using Chromosomes to Teach Evolution: Chromosomal Rearrangements in Speciation Events.

    Science.gov (United States)

    Offner, Susan

    1994-01-01

    Uses diagrams to aid in discussing how the English map of the human chromosomes, published by Offner in 1993, can be used to illustrate some important questions in evolution, as well as give students a glimpse into some of the mechanisms underlying evolutionary change. (ZWH)

  10. Programming social behavior by the maternal fragile X protein.

    Science.gov (United States)

    Zupan, B; Sharma, A; Frazier, A; Klein, S; Toth, M

    2016-07-01

    The developing fetus and neonate are highly sensitive to maternal environment. Besides the well-documented effects of maternal stress, nutrition and infections, maternal mutations, by altering the fetal, perinatal and/or early postnatal environment, can impact the behavior of genetically normal offspring. Mutation/premutation in the X-linked FMR1 (encoding the translational regulator FMRP) in females, although primarily responsible for causing fragile X syndrome (FXS) in their children, may also elicit such maternal effects. We showed that a deficit in maternal FMRP in mice results in hyperactivity in the genetically normal offspring. To test if maternal FMRP has a broader intergenerational effect, we measured social behavior, a core dimension of neurodevelopmental disorders, in offspring of FMRP-deficient dams. We found that male offspring of Fmr1(+/-) mothers, independent of their own Fmr1 genotype, exhibit increased approach and reduced avoidance toward conspecific strangers, reminiscent of 'indiscriminate friendliness' or the lack of stranger anxiety, diagnosed in neglected children and in patients with Asperger's and Williams syndrome. Furthermore, social interaction failed to activate mesolimbic/amygdala regions, encoding social aversion, in these mice, providing a neurobiological basis for the behavioral abnormality. This work identifies a novel role for FMRP that extends its function beyond the well-established genetic function into intergenerational non-genetic inheritance/programming of social behavior and the corresponding neuronal circuit. As FXS premutation and some psychiatric conditions that can be associated with reduced FMRP expression are more prevalent in mothers than full FMR1 mutation, our findings potentially broaden the significance of FMRP-dependent programming of social behavior beyond the FXS population. PMID:27198123

  11. Chromosomal imbalances in four new uterine cervix carcinoma derived cell lines

    Directory of Open Access Journals (Sweden)

    Vázquez Guelaguetza

    2003-03-01

    Full Text Available Abstract Background Uterine cervix carcinoma is the second most common female malignancy worldwide and a major health problem in Mexico, representing the primary cause of death among the Mexican female population. High risk human papillomavirus (HPV infection is considered to be the most important risk factor for the development of this tumor and cervical carcinoma derived cell lines are very useful models for the study of viral carcinogenesis. Comparative Genomic Hybridization (CGH experiments have detected a specific pattern of chromosomal imbalances during cervical cancer progression, indicating chromosomal regions that might contain genes that are important for cervical transformation. Methods We performed HPV detection and CGH analysis in order to initiate the genomic characterization of four recently established cervical carcinoma derived cell lines from Mexican patients. Results All the cell lines were HPV18 positive. The most prevalent imbalances in the cell lines were gains in chromosomes 1q23-q32, 3q11.2-q13.1, 3q22-q26.1, 5p15.1-p11.2, this alteration present as a high copy number amplification in three of the cell lines, 7p15-p13, 7q21, 7q31, 11q21, and 12q12, and losses in 2q35-qter, 4p16, 6q26-qter, 9q34 and 19q13.2-qter. Conclusions Analysis of our present findings and previously reported data suggest that gains at 1q31-q32 and 7p13-p14, as well as losses at 6q26-q27 are alterations that might be unique for HPV18 positive cases. These chromosomal regions, as well as regions with high copy number amplifications, coincide with known fragile sites and known HPV integration sites. The general pattern of chromosomal imbalances detected in the cells resembled that found in invasive cervical tumors, suggesting that the cells represent good models for the study of cervical carcinoma.

  12. A microdeletion of less than 250 kb, including the proximal part of the FMR-1 gene and the fragile-X site, in a male with the clinical phenotype of fragile-X syndrome

    OpenAIRE

    Wöhrle, Doris; Kotzot, Dieter; Hirst, Mark C; Manca, Antonella; Korn, Bernhard; Schmidt, Angela; Barbi, Gotthold; Rott, Hans-Dieter; Poustka, Annemarie; Davies, Kay E.; Steinbach, Peter

    1992-01-01

    A gene designated “FMR-1” has been isolated at the fragile-X locus. One exon of this gene is carried on a 5.1-kb EcoRI fragment that exhibits length variation in fragile-X patients because of amplification of or insertion into a CGG-repeat sequence. This repeat probably represents the fragile site. The EcoRI fragment also includes an HTF island that is hypermethylated in fragile-X patients showing absence of FMR-1 mRNA. In this paper, we present further evidence that the FMR-1 gene is involve...

  13. Maternal uniparental disomy of chromosome 14 in a boy with t(14q14q) associated with a paternal t(13q14q)

    Energy Technology Data Exchange (ETDEWEB)

    Tomkins, D.J.; Waye, J.S.; Whelan, D.T. [McMaster Univ., Ontario (Canada)] [and others

    1994-09-01

    An 11-year-old boy was referred for chromosomal analysis because of precocious development and behavioral problems suggestive of the fragile X syndrome. The cytogenetic fragile X studies were normal, but a routine GTG-banded karyotype revealed an abnormal male karyotype with a Robertsonian translocation between the two chromosome 14`s: 46,XY,t(14q14q). Paternal karyotyping revealed another abnormal karyotype: 46,XY,t(13q14q). A brother had the same karyotype as the father; the mother was deceased. In order to determine if the apparently balanced t(14q14q) in the proband might be the cause of the clinical findings, molecular analysis of the origin of the chromosome 14`s was initiated. Southern blotting and hybridization with D4S13 showed that the proband had two copies of one maternal allele which was shared by his brother. The brother`s second allele corresponded to one of the paternal alleles; the proband had no alleles from the father. Analysis of four other VNTRs demonstrated the probability of paternity to be greater than 99%. Thus, the t(14q14q) was most likely composed of two maternal chromosome 14`s. Further characterization of the t(14q14q) by dinucleotide repeat polymorphic markers is in progress to determine whether it has arisen from maternal isodisomy or heterodisomy. Several cases of uniparental disomy for chromosome 14 have been reported recently. Paternal disomy appears to be associated with more severe congenital anomalies and mental retardation, whereas maternal disomy may be associated with premature puberty and minimal intellectual impairment. The origin of the t(14q14q) in the present case may be related to the paternal translocation, as the segregation of the t(13q14q) in meiosis could lead to sperm that are nullisomic for chromosome 14.

  14. Characterization of chromosome structures of Falconinae (Falconidae, Falconiformes, Aves) by chromosome painting and delineation of chromosome rearrangements during their differentiation

    OpenAIRE

    Nishida, Chizuko; Ishijima, Junko; KOSAKA, Ayumi; Tanabe, Hideyuki; Habermann, Felix A.; Griffin, Darren K.; MATSHUDA, Yoichi; 秀之, 田辺

    2008-01-01

    Karyotypes of most bird species are characterized by around 2n = 80 chromosomes, comprising 7–10 pairs of large- and medium-sized macrochromosomes including sex chromosomes and numerous morphologically indistinguishable microchromosomes. The Falconinae of the Falconiformes has a different karyotype from the typical avian karyotype in low chromosome numbers, little size difference between macrochromosomes and a smaller number of microchromosomes. To characterize chromosome structures of Falcon...

  15. Characterization of chromosome structures of Falconinae (Falconidae, Falconiformes, Aves) by chromosome painting and delineation of chromosome rearrangements during their differentiation

    OpenAIRE

    Nishida, Chizuko; Ishijima, Junko; KOSAKA, Ayumi; Tanabe, Hideyuki; Habermann, Felix A.; Griffin, Darren K.; Matsuda, Yoichi

    2008-01-01

    Karyotypes of most bird species are characterized by around 2n = 80 chromosomes, comprising 7Y10 pairs of large- and medium-sized macrochromosomes including sex chromosomes and numerous morphologically indistinguishable microchromosomes. The Falconinae of the Falconiformes has a different karyotype from the typical avian karyotype in low chromosome numbers, little size difference between macrochromosomes and a smaller number of microchromosomes. To characterize chromosome structures of Falcon...

  16. Seismic fragility analysis of seismically isolated nuclear power plants piping system

    International Nuclear Information System (INIS)

    Highlights: • The critical points of a seismically isolated NPP piping system are identified. • The simulation results are validated through a monotonic and cyclic test of the critical points. • The conditional mean spectrum method is used to scale the selected records. • The fragility curves of the NPP piping system are estimated. • Computation of the fragility parameters is addressed. - Abstract: Nuclear power plants are high risk facilities due to the possibility of sudden seismic events, because any possible failure could initiate catastrophic radioactive contamination. The seismic fragility analysis of NPPs and related equipments (such as piping systems) is a proven method to determine their performance against any possible earthquake. In this study the Brookhaven National laboratory benchmark model of a piping system was considered for the fragility analysis. A tensile test was conducted to define the material properties. An initial seismic analysis of the piping system is performed to indicate the critical sections of the piping system. Numerical analysis was validated through a monotonic and cyclic loading experiment of two identified critical points of the piping system. The tests were conducted at the Korea Construction Engineering Development (KOCED) Seismic Simulation Test Center, Pusan National University, Korea. Fragility curves were expressed for critical points of the system as a function of the spectral acceleration of the records and the maximum relative displacement. The standard deviation of the response and capacity were calculated using mathematical formulas, assuming that those follow a log-normal distribution. We determined that the fragility curve of a pipe elbow must be derived for both the opening and closing mode, regarding the difference between the capacities of the elbow on those modes. The high confidence of low probability of failure for the considered fragility functions in a straight section in any direction is

  17. Seismic fragility analysis of seismically isolated nuclear power plants piping system

    Energy Technology Data Exchange (ETDEWEB)

    Salimi Firoozabad, Ehsan, E-mail: e.salimi@pusan.ac.kr [Department of Civil and Environmental Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Jeon, Bub-Gyu, E-mail: bkjeon79@pusan.ac.kr [KOCED Seismic Simulation Test Center, Pusan National University, Yangsan Campus Mulgeum, Yangsan, Kyungsangnam (Korea, Republic of); Choi, Hyoung-Suk, E-mail: engineer@pusan.ac.kr [KOCED Seismic Simulation Test Center, Pusan National University, Yangsan Campus Mulgeum, Yangsan, Kyungsangnam (Korea, Republic of); Kim, Nam-Sik, E-mail: nskim@pusan.ac.kr [Department of Civil and Environmental Engineering, Pusan National University, 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

    2015-04-01

    Highlights: • The critical points of a seismically isolated NPP piping system are identified. • The simulation results are validated through a monotonic and cyclic test of the critical points. • The conditional mean spectrum method is used to scale the selected records. • The fragility curves of the NPP piping system are estimated. • Computation of the fragility parameters is addressed. - Abstract: Nuclear power plants are high risk facilities due to the possibility of sudden seismic events, because any possible failure could initiate catastrophic radioactive contamination. The seismic fragility analysis of NPPs and related equipments (such as piping systems) is a proven method to determine their performance against any possible earthquake. In this study the Brookhaven National laboratory benchmark model of a piping system was considered for the fragility analysis. A tensile test was conducted to define the material properties. An initial seismic analysis of the piping system is performed to indicate the critical sections of the piping system. Numerical analysis was validated through a monotonic and cyclic loading experiment of two identified critical points of the piping system. The tests were conducted at the Korea Construction Engineering Development (KOCED) Seismic Simulation Test Center, Pusan National University, Korea. Fragility curves were expressed for critical points of the system as a function of the spectral acceleration of the records and the maximum relative displacement. The standard deviation of the response and capacity were calculated using mathematical formulas, assuming that those follow a log-normal distribution. We determined that the fragility curve of a pipe elbow must be derived for both the opening and closing mode, regarding the difference between the capacities of the elbow on those modes. The high confidence of low probability of failure for the considered fragility functions in a straight section in any direction is

  18. Raman and DSC studies of fragility in tellurium-zinc oxide glass formers

    Energy Technology Data Exchange (ETDEWEB)

    Stavrou, Elissaios [Department of Physics, National Technical University of Athens (Greece); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Kripotou, Sotiria; Raptis, Constantine [Department of Physics, National Technical University of Athens (Greece); Turrell, Sylvia [Laboratoire de Spectrochimie Infrarouge et Raman (CNRS 8516), Centre d' Etudes et de Recherches Lasers et Applications (CERLA-FR CNRS 2416), Universite de Sciences et Technologies de Lille, Villeneuve d' Ascq cedex (France); Syassen, Karl [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

    2011-11-15

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out in four mixed (TeO{sub 2}){sub 1-x}(ZnO){sub x} (x = 0.1, 0.2, 0.3, 0.4) glasses at high temperatures (Raman and DSC through the glass transition) and high pressures (Raman) with the aim of determining the fragility of these glass forming oxides. Four different criteria, corresponding to four parameters, were applied to assess the fragility of the glasses. From the DSC studies, we have obtained the fragility parameter m which corresponds to the slopes of Arrhenius (lnQ vs. 1/T{sub g}, were Q is the heating rate) plots, and the glass transition width {delta}T{sub g}. Also, from the low-frequency Raman scattering, and in particular the boson peak intensity of the glasses at T{sub g}, we have estimated the fragility ratio r{sub R} (T{sub g}) = I{sub min}/I{sub max} whose value serves as another (empirical) fragility criterion. Finally, from high pressure Raman measurements on the glasses, we have estimated the Grueneisen parameter {gamma}{sub T} for each glass, which constitutes the fourth fragility parameter adopted in this work. Considering the four parameters {delta}T{sub g}, m, r (T{sub g}) and {gamma}{sub T} and the generally accepted (empirical) fragility criteria, we conclude that the mixed tellurium-zinc oxides constitute strong-to-intermediate glass formers (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Glassy properties and viscous slowing down: An analysis of the correlation between nonergodicity factor and fragility.

    Science.gov (United States)

    Niss, Kristine; Dalle-Ferrier, Cécile; Giordano, Valentina M; Monaco, Giulio; Frick, Bernhard; Alba-Simionesco, Christiane

    2008-11-21

    We present an extensive analysis of the proposed relationship [T. Scopigno et al., Science 302, 849 (2003)] between the fragility of glass-forming liquids and the nonergodicity factor as measured by inelastic x-ray scattering. We test the robustness of the correlation through the investigation of the relative change under pressure of the speed of sound, nonergodicity factor, and broadening of the acoustic exitations of a molecular glass former, cumene, and of a polymer, polyisobutylene. For polyisobutylene, we also perform a similar study by varying its molecular weight. Moreover, we have included new results on liquids presenting an exceptionally high fragility index m under ambient conditions. We show that the linear relation, proposed by Scopigno et al. [Science 302, 849 (2003)] between fragility, measured in the liquid state, and the slope alpha of the inverse nonergodicity factor as a function of T/T(g), measured in the glassy state, is not verified when increasing the data base. In particular, while there is still a trend in the suggested direction at atmospheric pressure, its consistency is not maintained by introducing pressure as an extra control parameter modifying the fragility: whatever is the variation in the isobaric fragility, the inverse nonergodicity factor increases or remains constant within the error bars, and one observes a systematic increase in the slope alpha when the temperature is scaled by T(g)(P). To avoid any particular aspects that might cause the relation to fail, we have replaced the fragility by other related properties often evoked, e.g., thermodynamic fragility, for the understanding of its concept. Moreover, we find, as previously proposed by two of us [K. Niss and C. Alba-Simionesco, Phys. Rev. B 74, 024205 (2006)], that the nonergodicity factor evaluated at the glass transition qualitatively reflects the effect of density on the relaxation time even though in this case no clear quantitative correlations appear. PMID:19026072

  20. The fragile X protein controls microtubule-associated protein 1B translation and microtubule stability in brain neuron development

    OpenAIRE

    Lu, Robert; Wang, Houping; Liang, Zhe; Ku, Li; O'Donnell, William T.; Li, Wen; Warren, Stephen T; Feng, Yue

    2004-01-01

    The fragile X mental retardation protein (FMRP) is a selective RNA-binding protein implicated in regulating translation of its mRNA ligands. The absence of FMRP results in fragile X syndrome, one of the leading causes of inherited mental retardation. Delayed dendritic spine maturation was found in fragile X mental retardation patients as well as in Fmr1 knockout (KO) mice, indicating the functional requirement of FMRP in synaptic development. However, the biochemical link between FMRP deficie...