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Sample records for andidentical twins discordant

  1. Behavioral versus genetic determination of lipoproteins andidentical twins discordant for exercise

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Paul T.; Blanche, Patricia J.; Krauss, Ronald M.

    2004-06-01

    Lipoprotein and weight differences between vigorously active and sedentary MZ twins are used to: (1) estimate the effects of training while controlling for genotype; (2) estimate genetic concordance in the presence of divergent lifestyles.

  2. Monozygotic twins discordant for rubinstein-taybi syndrome.

    OpenAIRE

    Kajii, T; Hagiwara, K.; Tsukahara, M; Nakajima, H; Fukuda, Y.

    1981-01-01

    A pair of male monozygotic twins discordant for Rubinstein-Taybi syndrome is reported. Monozygosity of the twins was established using blood grouping, typing of serum proteins, isozymes, HLA, and chromosomal heteromorphisms. The twins are the first twin pair discordant for the syndrome in which monozygosity has been firmly established. The pathogenesis of the syndrome is discussed in relation to the occurrence of both discordant and concordant monozygotic twins.

  3. Epigenetic signature of birth weight discordance in adult twins

    DEFF Research Database (Denmark)

    Tan, Qihua; Nielsen, Morten Frost Munk; Heijmans, Bastiaan T;

    2014-01-01

    between birth weight and adult life health while controlling for not only genetics but also postnatal rearing environment. We performed an epigenome-wide profiling on blood samples from 150 pairs of adult monozygotic twins discordant for birth weight to look for molecular evidence of epigenetic signatures...... profiling did not reveal epigenetic signatures of birth weight discordance although some sites displayed age-dependent intra-pair differential methylation in the extremely discordant twin pairs....

  4. Trisomy 13 in monozygotic twins discordant for major congenital anomalies.

    OpenAIRE

    Naor, N; Amir, Y; Cohen, T; Davidson, S.

    1987-01-01

    The occurrence of trisomy 13 in twins is very rare. We report a pair of genotypically identical twins with trisomy 13 discordant for major anomalies. This case contributes to the already published data on the contribution of non-genetic factors to the aetiology of congenital malformations in monozygotic twins.

  5. Dicephalus parapagus conjoined twins discordant for anencephaly: a case report

    OpenAIRE

    Udo Jacob J; Archibong Ayi E; Olasode Babatunde J; Usang Usang E; Eduwem Diana-Abasi U

    2010-01-01

    Abstract Introduction Cases of conjoined twins occur so rarely that it is important to learn as much as possible from each case. Case presentation We present a case of 9-hour-old, female, Nigerian dicephalus parapagus conjoined twins discordant for anencephaly diagnosed only after the birth of the twins. The anencephalic twin was stillborn while the normal one died within 9 hours of birth from cardiopulmonary failure. Conclusion Many congenital defects of interest can now be detected before b...

  6. Adult glucose metabolism in extremely birthweight-discordant monozygotic twins

    DEFF Research Database (Denmark)

    Frost, M; Petersen, I; Brixen, K;

    2012-01-01

    Low birthweight (BW) is associated with increased risk of type 2 diabetes. We compared glucose metabolism in adult BW-discordant monozygotic (MZ) twins, thereby controlling for genetic factors and rearing environment.......Low birthweight (BW) is associated with increased risk of type 2 diabetes. We compared glucose metabolism in adult BW-discordant monozygotic (MZ) twins, thereby controlling for genetic factors and rearing environment....

  7. Dichorionic twin pregnancy discordant for fetal anencephaly: a case report

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    Yasemin Taşcı

    2012-03-01

    Full Text Available Dichorionic twin pregnancy discordant for fetal anencephaly is a serious condition that threatens the normal co-twin’s life by causing polyhydramniosis, preterm labor and sudden death of one or both of the fetuses. We report a case of dichorionic twin pregnancy discordant for fetal anencephaly delivered at the 32nd week of gestation because of preterm labor and nonreassuring fetal monitoring. The aim of this case report is to summarize management options in this situation.

  8. Dichorionic twin pregnancy discordant for fetal anencephaly: a case report

    OpenAIRE

    Yasemin Taşcı; Yetkin Karasu 2; Özlem Erten; Burak Karadağ; Ümit Göktolga

    2012-01-01

    Dichorionic twin pregnancy discordant for fetal anencephaly is a serious condition that threatens the normal co-twin’s life by causing polyhydramniosis, preterm labor and sudden death of one or both of the fetuses. We report a case of dichorionic twin pregnancy discordant for fetal anencephaly delivered at the 32nd week of gestation because of preterm labor and nonreassuring fetal monitoring. The aim of this case report is to summarize management options in this situation.

  9. Whole-Exome Sequencing in Nine Monozygotic Discordant Twins.

    Science.gov (United States)

    Zhang, Rong; Thiele, Holger; Bartmann, Peter; Hilger, Alina C; Berg, Christoph; Herberg, Ulrike; Klingmüller, Dietrich; Nürnberg, Peter; Ludwig, Michael; Reutter, Heiko

    2016-02-01

    By definition, monozygotic (MZ) twins carry an identical set of genetic information. The observation of early post-twinning mutational events was shown to cause phenotypic discordance among MZ twin pairs. These mutational events comprise genomic alterations at different scales, ranging from single nucleotide changes to larger copy-number variations (CNVs) of varying sizes, as well as epigenetic changes. Here, we performed whole-exome sequencing (WES) in nine discordant MZ twins to identify somatic mutational events in the affected twin that might exert a dominant negative effect. Five of these MZ twin pairs were discordant for congenital heart defects (CHD), two for endocrine disorders, one for omphalocele, and one for congenital diaphragmatic hernia (CDH). Analysis of WES data from all nine MZ twin pairs using the de novo probability tool DeNovoGear detected only one apparent de novo variation in TMPRSS13 in one of the CHD-affected twins. Analysis of WES data from all nine MZ twin pairs by using standard filter criteria without the de novo probability tool DeNovoGear revealed a total of 6,657 variations in which both the twin pairs differed. After filtering for variations only present in the affected twins and absent in in-house controls, 722 variations remained. Visual inspection for read quality decreased this number to 12, present only in the affected twin. However, Sanger sequencing of the overall 13 variations failed to confirm the variation in the affected twin. These results suggest that somatic mutational events in coding regions do not seem to play a major role in the phenotypic expression of MZ discordant twin pairs. PMID:26681452

  10. Monozygotic twins with discordant intestinal rotation

    International Nuclear Information System (INIS)

    Previous case reports have suggested a strong concordance of intestinal malrotation among identical twins. This has led to the recommendation that the asymptomatic twin undergo screening when malrotation is discovered in the identical sibling. We present a case of monozygotic twins in which one twin presented with intestinal malrotation with midgut volvulus while the other twin was found to have normal gastrointestinal anatomy. (orig.)

  11. Monozygotic twins with discordant intestinal rotation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Vance L.; Nwomeh, Benedict C. [Ohio State University College of Medicine and Public Health, Department of Pediatric Surgery, Columbus Children' s Hospital, Columbus, OH (United States); Long, Frederick [Ohio State University College of Medicine and Public Health, Department of Radiology, Columbus Children' s Hospital, Columbus, OH (United States)

    2006-04-15

    Previous case reports have suggested a strong concordance of intestinal malrotation among identical twins. This has led to the recommendation that the asymptomatic twin undergo screening when malrotation is discovered in the identical sibling. We present a case of monozygotic twins in which one twin presented with intestinal malrotation with midgut volvulus while the other twin was found to have normal gastrointestinal anatomy. (orig.)

  12. Twin birth order, birthweight and birthweight discordance: any relationship

    Directory of Open Access Journals (Sweden)

    Onyiriuka A.N.

    2010-12-01

    Full Text Available Background: It is widely believed that in twin pairs, at birth, the first-born weigh more than the second-born but this concept has been challenged. Objective: To assess the truthfulness of this common concept that first-born twins are usually heavier than their second-born siblings at birth. Methods: In a series of 104 sets of live-born twins, the birth weights of first-born twins were compared with those of their second-born siblings, after controlling for gender. Their intra-pair birthweight differences were determined and twin pairs whose birthweight difference was 15% or more were designated as discordant. Results: Twin I was heavier than Twin II in 61.5% of cases while Twin II was heavier than Twin I in 28.9% of cases. Twins I and II had equal birthweights in 9.6% of cases. Comparing the mean birthweight of the first-born-male twin with that of second-born- male twin, it was 2515+427g (95% Confidence Interval, CI=2402-2628 versus 2432 +435g (95% CI=2321-2543 p>0.05. The mean birthweight of first-born-female twin was 2326+445g (95% CI=2214-2439 while that of the second-born-female twin was 2325+501g (95% CI=2197-2453 p>0.05. When the birthweight difference exceeded 750g, the probability that Twin I will be heavier than Twin II was 83.3% (5 of 6. Conclusion: Although the first-born twin was more often heavier than their second-born siblings, either could weigh more or less at birth. The larger the birthweight difference between growth-discordant twin pair, the greater the probability that the heavier twin would be delivered first

  13. Personality development in monozygotic twins of varying IQ discordance

    OpenAIRE

    Salomonsson, Sally

    2013-01-01

    The present study sought to investigate the personality-intelligence association by using longitudinal MZ twin data to examine if intelligence and personality are developmentally linked. If twins discordant for IQ in childhood grew up to differ more in personality than twins of very similar intelligence, it would support theories of personality and intelligence that posit a developmental interaction between the two and a non-shared environmental influence can be inferred. It was also investiga...

  14. Monoamniotic Monochorionic Twins Discordant for Noncompaction Cardiomyopathy

    OpenAIRE

    Ng, Dianna; Bouhlal, Yosr; Ursell, Philip C.; Shieh, Joseph T. C.

    2013-01-01

    Occasionally “identical twins” are phenotypically different, raising the question of zygosity and the issue of genetic versus environmental influences during development. We recently noted monochorionic-monoamniotic twins, one of which had an isolated cardiac abnormality, noncompaction cardiomyopathy, a condition characterized by cardiac ventricular hypertrabeculation. We examined the prenatal course and subsequent pathologic correlation since ventricular morphogenesis may depend on early mus...

  15. Dicephalus parapagus conjoined twins discordant for anencephaly: a case report

    Directory of Open Access Journals (Sweden)

    Udo Jacob J

    2010-02-01

    Full Text Available Abstract Introduction Cases of conjoined twins occur so rarely that it is important to learn as much as possible from each case. Case presentation We present a case of 9-hour-old, female, Nigerian dicephalus parapagus conjoined twins discordant for anencephaly diagnosed only after the birth of the twins. The anencephalic twin was stillborn while the normal one died within 9 hours of birth from cardiopulmonary failure. Conclusion Many congenital defects of interest can now be detected before birth. A severe lesion such as that found in our index case, which is incompatible with postnatal life, requires counselling. If detected early enough during a properly monitored antenatal care, it may indicate termination of pregnancy.

  16. Chromosome 22q11.2 microdeletion in monozygotic twins with discordant phenotype and deletion size

    OpenAIRE

    Halder Ashutosh; Jain Manish; Chaudhary Isha; Varma Binuja

    2012-01-01

    Abstract We report on a pair of male monozygotic twins with 22q11.2 microdeletion, discordant phenotype and discordant deletion size. The second twin had findings suggestive of DiGeorge syndrome, while the first twin had milder anomalies without any cardiac malformation. The second twin had presented with intractable convulsion, cyanosis and cardiovascular failure in the fourth week of life and expired on the sixth week of life, whereas the first twin had some characteristic facial appearance...

  17. Epigenetic differences in monozygotic twins discordant for major depressive disorder.

    Science.gov (United States)

    Malki, K; Koritskaya, E; Harris, F; Bryson, K; Herbster, M; Tosto, M G

    2016-01-01

    Although monozygotic (MZ) twins share the majority of their genetic makeup, they can be phenotypically discordant on several traits and diseases. DNA methylation is an epigenetic mechanism that can be influenced by genetic, environmental and stochastic events and may have an important impact on individual variability. In this study we explored epigenetic differences in peripheral blood samples in three MZ twin studies on major depressive disorder (MDD). Epigenetic data for twin pairs were collected as part of a previous study using 8.1-K-CpG microarrays tagging DNA modification in white blood cells from MZ twins discordant for MDD. Data originated from three geographical regions: UK, Australia and the Netherlands. Ninety-seven MZ pairs (194 individuals) discordant for MDD were included. Different methods to address non independently-and-identically distributed (non-i.i.d.) data were evaluated. Machine-learning methods with feature selection centered on support vector machine and random forest were used to build a classifier to predict cases and controls based on epivariations. The most informative variants were mapped to genes and carried forward for network analysis. A mixture approach using principal component analysis (PCA) and Bayes methods allowed to combine the three studies and to leverage the increased predictive power provided by the larger sample. A machine-learning algorithm with feature reduction classified affected from non-affected twins above chance levels in an independent training-testing design. Network analysis revealed gene networks centered on the PPAR-γ (NR1C3) and C-MYC gene hubs interacting through the AP-1 (c-Jun) transcription factor. PPAR-γ (NR1C3) is a drug target for pioglitazone, which has been shown to reduce depression symptoms in patients with MDD. Using a data-driven approach we were able to overcome challenges of non-i.i.d. data when combining epigenetic studies from MZ twins discordant for MDD. Individually, the studies yielded

  18. The effect of twin discordancy on pregnancy outcome

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    Niroomand N

    2007-08-01

    Full Text Available Background: The aim of this survey was to evaluate the prevalence of some perinatal complications in birth weight discordance (BWD among twin pregnancies. Methods: In a descriptive analytical cross-sectional study, 490 twin neonates (245 twin pregnancies born at Mirzakoochakkhan Hospital from 1999 to 2003 were evaluated. Maternal and neonatal data of each delivery were collected for BWD, gestational age, maternal age, parity, infant gender, neonatal death, neonatal septicemia, mode of delivery, hyperbilirubinemia, blood transfusion and duration of hospitalization. Results: The average age of the mothers was 26±4.78 years, of which 51.8% were nullipara. The average gestational age was 35.02±2.73 weeks, with 15.9% before 32 weeks of gestation. The neonatal death rate was 7.8%, the majority of which involved male neonates and multiparas. The average duration of hospitalization was 6.07±4.45 days, 8.5 days for those twins with BWD≥20%, and longer (9.14 days for neonates with mothers younger than 20 years old. Septicemia was most frequent (31.3% in twins with BWD of 30-34%, as was hyperbilirubinemia requiring blood transfusion (25%. Hyperbilirubinemia was more common in neonates with mothers aged less than 20 years and more than 35 years.. Conclusions: BWD in twins is a predictive factor for septicemia and hyperbilirubinemia requiring transfusion. Therefore, healthcare workers and hospital wards dealing with twins with BWD should be especially ready and equipped to provide the additional care needed for these patients.

  19. Cognitive function in unaffected twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Christensen, Maj Vinberg; Kyvik, Kirsten Ohm; Kessing, Lars Vedel

    2006-01-01

    . Cognitive performance of 203 High-Risk and Low-Risk twins was compared. RESULTS: Healthy twins discordant for unipolar disorder showed lower performance on almost all measures of cognitive function: selective and sustained attention, executive function, language processing and working and declarative memory...... on language processing and episodic memory. CONCLUSIONS: The hypothesis that discrete cognitive impairment is present before the onset of the affective disorder and is genetically transmitted was supported. Thus, cognitive function may be a candidate endophenotype for affective disorders.......BACKGROUND: Patients may present with cognitive impairment in the euthymic phase of affective disorder, but it is unclear whether the impairment is prevalent before onset of the illness. The aim of the present study was to examine the hypothesis that genetic liability to affective disorder...

  20. Monozygotic twins concordant and discordant for DCD: two sides to the story.

    Science.gov (United States)

    Pearsall-Jones, Jillian G; Piek, Jan P; Steed, Lyndall; McDougall, Megan R; Levy, Florence

    2011-02-01

    Being an identical twin does not necessarily mean having identical perceptions of family functioning, nor of the twin relationship. Using the co-twin control design, the aim of this study was to explore perceptions of family dynamics and the twin relationship in monozygotic (MZ) twins discordant and concordant for Developmental Coordination Disorder (DCD). It was hypothesized that, as has been found in twins discordant for cerebral palsy, twins without DCD would perceive family functioning as less healthy than would their co-twins with DCD. It was also hypothesized that the twin relationship would be regarded generally as mutually supportive. Questionnaire data on 866 sets of MZ twins aged 6 to 17 years were used to identify seven sets discordant, and two sets concordant for DCD. Quantitative (General Functioning Scale of the Family Assessment Device - FAD), and qualitative (semi-structured interview) measures were used to assess family dynamics and the twin relationship. In discordant sets, six of seven twins without DCD rated family functioning at a less healthy level than did their co-twins with DCD. All twins in the DCD concordant sets rated their family functioning at a healthy level. From the semi-structured interviews, emergent themes included friendship, support, minimal sibling rivalry, and minor difficulties. It was concluded that, overall, the twin relationship was regarded as close and mutually supportive, with an ambivalent polarity between the best and most difficult aspects of being an identical twin. Implications for research, policy and clinical practice are discussed. PMID:21314259

  1. Search for Genomic Alterations in Monozygotic Twins Discordant for Cleft Lip and/or Palate

    DEFF Research Database (Denmark)

    Kimani, Jane W; Yoshiura, Koh-Ichiro; Shi, Min;

    2009-01-01

    consisting of 1,536 SNPs, to scan for genomic alterations in a sample of monozygotic twin pairs with discordant cleft lip and/or palate phenotypes. Paired analysis for deletions, amplifications and loss of heterozygosity, along with sequence verification of SNPs with discordant genotype calls did not reveal...... any genomic discordance between twin pairs in lymphocyte DNA samples. Our results demonstrate that postzygotic genomic alterations are not a common cause of monozygotic twin discordance for isolated cleft lip and/or palate. However, rare or balanced genomic alterations, tissue-specific events and...

  2. A Case of Monozygotic Twins: The Value of Discordant Monozygotic Twins in Goldenhar Syndrome—OMIM%164210

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    K. N. Venkateshwara Prasad

    2013-01-01

    Full Text Available Goldenhar syndrome is a rare developmental disorder characterised by hemifacial microsomia, epibulbar tumours, ear malformation, and vertebral anomalies. As monozygotic (MZ twins are believed to be genetically identical, discordance for disease phenotype between MZ twins varies with craniofacial anomalies, cardiac, vertebral, and central nervous system defects sporadically. We report a case of monozygotic female twins discordant for Goldenhar syndrome with hemifacial microsomia and the dysplasia of auricular pinna.

  3. A Case of Monozygotic Twins: The Value of Discordant Monozygotic Twins in Goldenhar Syndrome—OMIM%164210

    OpenAIRE

    Venkateshwara Prasad, K. N.; Arvind Rajha; Pradeep Kumar Vegi

    2013-01-01

    Goldenhar syndrome is a rare developmental disorder characterised by hemifacial microsomia, epibulbar tumours, ear malformation, and vertebral anomalies. As monozygotic (MZ) twins are believed to be genetically identical, discordance for disease phenotype between MZ twins varies with craniofacial anomalies, cardiac, vertebral, and central nervous system defects sporadically. We report a case of monozygotic female twins discordant for Goldenhar syndrome with hemifacial microsomia and the dyspl...

  4. Methylomic analysis of monozygotic twins discordant for autism spectrum disorder and related behavioural traits

    OpenAIRE

    Wong, C.C.Y.; Meaburn, E L; Ronald, A.; Price, T. S.; Jeffries, A.R.; Schalkwyk, L.C.; Plomin, R.; Mill, J.

    2014-01-01

    Autism spectrum disorder (ASD) defines a group of common, complex neurodevelopmental disorders. Although the aetiology of ASD has a strong genetic component, there is considerable monozygotic (MZ) twin discordance indicating a role for non-genetic factors. Because MZ twins share an identical DNA sequence, disease-discordant MZ twin pairs provide an ideal model for examining the contribution of environmentally driven epigenetic factors in disease. We performed a genome-wide analysis of DNA met...

  5. Discordance for fetal anencephaly in a dichorionic twin pregnancy: A case report

    OpenAIRE

    Isabel Cerveira; Ana Sousa; Laura Raposo; Joana Batista

    2013-01-01

    Anencephaly is a frequent and easily diagnosed condition affecting twin pregnancies with higher incidence than singletons. Discordance for anencephaly in twins raises management dilemmas about the best approach to the situation. The authors report a successful case of a 33 years old woman who had a dichorionic twin pregnancy resulting from ICSI, with discordance for anencephaly. Diagnosis was performed at 13 weeks during first trimester ultrasound screening. A selective feticide with intrath...

  6. Comparison of Genomic and Epigenomic Expression in Monozygotic Twins Discordant for Rett Syndrome

    OpenAIRE

    Kunio, Miyake; YANG, CHUNSHU; Minakuchi, Yohei; Ohori, Kenta; Soutome, Masaki; Hirasawa, Takae; Kazuki, Yasuhiro; Adachi, Noboru; Suzuki, Seiko; Itoh, Masayuki; Goto, Yu-ichi; Andoh, Tomoko; Kurosawa, Hiroshi; Akamatsu, Wado; Ohyama, Manabu

    2013-01-01

    Monozygotic (identical) twins have been widely used in genetic studies to determine the relative contributions of heredity and the environment in human diseases. Discordance in disease manifestation between affected monozygotic twins has been attributed to either environmental factors or different patterns of X chromosome inactivation (XCI). However, recent studies have identified genetic and epigenetic differences between monozygotic twins, thereby challenging the accepted experimental model...

  7. Discordant phenotypes in monozygotic twins with identical de novo WT1 mutation

    OpenAIRE

    Yu, Zihua; Yang, Yonghui; Feng, Dongning

    2012-01-01

    Mutations in the WT1 gene, leading to Denys-Drash syndrome and Frasier syndrome, can also cause isolated steroid-resistant nephrotic syndrome (ISRNS). Previous studies have reported six pairs of monozygotic twins with WT1 mutations, including one presenting with discordant phenotypes with identical WT1 mutations being of paternal origin and five pairs of monozygotic twins presenting the same phenotype with identical WT1 mutations. In this study, we report on female monozygotic twins showing d...

  8. Mapping Corpus Callosum Morphology in Twin Pairs Discordant for Bipolar Disorder

    OpenAIRE

    Bearden, Carrie E.; van Erp, Theo G. M.; Dutton, Rebecca A.; Boyle, Christina; Madsen, Sarah; Luders, Eileen; Kieseppa, Tuula; Tuulio-Henriksson, Annamari; Huttunen, Matti; Partonen, Timo; Kaprio, Jaakko; Lönnqvist, Jouko; Thompson, Paul M.; Cannon, Tyrone D.

    2011-01-01

    Callosal volume reduction has been observed in patients with bipolar disorder, but whether these deficits reflect genetic vulnerability to the illness remains unresolved. Here, we used computational methods to map corpus callosum abnormalities in a population-based sample of twin pairs discordant for bipolar disorder. Twenty-one probands with bipolar I disorder (mean age 44.4 ± 7.5 years; 48% female), 19 of their non-bipolar co-twins, and 34 demographically matched control twin individuals un...

  9. Asthma discordance in twins is linked to epigenetic modifications of T cells.

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    R Scott Runyon

    Full Text Available T cells mediate the inflammatory responses observed in asthma among genetically susceptible individuals and have been suspected to be prone to epigenetic regulation. However, these relationships are not well established from past clinical studies that have had limited capacity to control for the effects of variable genetic predisposition and early environmental exposures. Relying on a cohort of monozygotic twins discordant for asthma we sought to determine if epigenetic modifications in T cells were associated with current asthma and explored whether such modifications were associated with second hand smoke exposures. Our study was conducted in a monozygotic twin cohort of adult twin pairs (n = 21 all discordant for asthma. Regulatory T cell (Treg and effector T cell (Teff subsets were assessed for levels of cellular function, protein expression, gene expression and CpG methylation within Forkhead box P3 (FOXP3 and interferon gamma-γ (IFNγ loci. Comparisons by asthma and current report of exposure to second hand smoke were made. Treg from asthmatic discordant twins demonstrated decreased FOXP3 protein expression and impaired Treg function that was associated with increased levels of CpG methylation within the FOXP3 locus when compared to their non-asthmatic twin partner. In parallel, Teff from discordant asthmatic twins demonstrated increased methylation of the IFNγ locus, decreased IFNγ expression and reduced Teff function when compared to Teff from the non-asthmatic twin. Finally, report of current exposure to second hand smoke was associated with modifications in both Treg and Teff at the transcriptional level among asthmatics. The results of the current study provide evidence for differential function of T cell subsets in monozygotic twins discordant for asthma that are regulated by changes in DNA methylation. Our preliminary data suggest exposure to second hand smoke may augment the modified T cell responses associated with asthma.

  10. Exploring Subclinical Phenotypic Features in Twin Pairs Discordant for Cleft Lip and Palate

    DEFF Research Database (Denmark)

    Leslie, Elizabeth J; Carlson, Jenna C; Cooper, Margaret E;

    2016-01-01

    OBJECTIVE: Monozygotic twins of an individual with an orofacial cleft have a significantly elevated risk for orofacial cleft compared with the general population, but still the concordance rate for orofacial cleft in monozygotic twins is about 40% to 50%. The goal of this study was to determine...... whether unaffected cotwins have an increased frequency of orbicularis oris muscle defects, a subclinical form of orofacial cleft. The presence of such defects may reduce the overall rate of discordance. METHOD: A total of 63 discordant monozygotic and dizygotic twin pairs, 262 unaffected nontwin siblings......, and 543 controls with no history of orofacial clefts were assessed for orbicularis oris defects by high-resolution ultrasound. Frequencies were compared by the Fisher exact test. RESULTS: Unaffected cotwins from discordant monozygotic pairs had a higher frequency of defects (12.5%) than the other test...

  11. Salivary cortisol in unaffected twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Vinberg, Maj; Bennike, Bente; Kyvik, Kirsten Ohm; Andersen, Per Kragh; Kessing, Lars Vedel

    2008-01-01

    Dysfunction in the hypothalamic-pituitary-adrenal (HPA) axis has been proposed as a biological endophenotype for affective disorders. In the present study the hypothesis that a high genetic liability to affective disorder is associated with higher cortisol levels was tested in a cross......-sectional high-risk study. Healthy monozygotic (MZ) and dizygotic (DZ) twins with (High-Risk twins) and without (Low-Risk twins) a co-twin history of affective disorder were identified through nationwide registers. Awakening and evening salivary cortisol levels were compared between the 190 High- and Low......-Risk twins. The 109 High-Risk twins had significantly higher evening cortisol levels than the 81 Low-Risk MZ twins, also after adjustment for age, sex, and the level of subclinical depressive symptoms. No significant difference was found in awakening cortisol levels between High-Risk and Low-Risk twins. In...

  12. Differentially Methylated Genomic Regions in Birth-Weight Discordant Twin Pairs

    DEFF Research Database (Denmark)

    Chen, Mubo; Baumbach, Jan; Vandin, Fabio; Röttger, Richard; Vieira Barbosa, Eudes Guilherme; Dong, Mingchui; Frost, Morten; Christiansen, Lene; Tan, Qihua

    2016-01-01

    regions. Whole genome DNA methylation levels were measured in whole blood from 150 pairs of adult identical twins discordant for birth-weight. Intrapair differential DNA methylation was associated with qualitative (large or small) and quantitative (percentage) birth-weight discordance at each genomic site...... twin pairs to find evidence for such “programming” effects, but no significant results emerged. We further investigated this issue using a new computational approach: Instead of probing single genomic sites for significant alterations in epigenetic marks, we scan for differentially methylated genomic...

  13. Twin Legacies: Victor and Vincent McKusick / Twin Studies: Twinning Rates I; Twinning Rates II; MZ Twin Discordance for Russell-Silver Syndrome; Twins' Language Skills / Headlines: Babies Born to Identical Twin Couples; Identity Exchange; Death of Princess Ashraf (Twin); Yahoo CEO Delivers Identical Twins.

    Science.gov (United States)

    Segal, Nancy L

    2016-04-01

    The lives of the illustrious monozygotic (MZ) twins, Victor A. and Vincent L. McKusick, are described. Victor earned the distinction as the 'Father of Medical Genetics', while Vincent was a legendary Chief Justice of the Maine Supreme Court. This dual biographical account is followed by two timely reports of twinning rates, a study of MZ twin discordance for Russell-Silver Syndrome (RSS) and a study of twins' language skills. Twin stories in the news include babies born to identical twin couples, a case of switched identity, the death of Princess Ashraf (Twin) and a new mother of twins who is also Yahoo's CEO. PMID:26934824

  14. Personality traits in unaffected twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Vinberg, M; Kyvik, Kirsten Ohm; Mortensen, E L; Kessing, L V

    2007-01-01

    multivariate analyses, a high genetic liability to affective disorder was not significantly associated with neuroticism but correlated to sex, minor psychopathology and recent life events. CONCLUSION: A high genetic liability to affective disorder showed an association with neuroticism, but the association......OBJECTIVE: To examine whether a high genetic liability to develop affective disorder is associated with specific personality traits. METHOD: A cross-sectional, high-risk, case-control study. Through nation-wide registers, healthy monozygotic (MZ) and dizygotic (DZ) twins with (high-risk twins) and...... without (the control group/low-risk twins) a co-twin history of affective disorder were identified. Personality traits were compared for a total of 211 high-risk and low-risk twins. RESULTS: In univariate analyses, the high-risk twins had a higher level of neuroticism than the control twins (P = 0.03). In...

  15. Birth weight discordant twins have increased prenatal mortality and neonatal morbidity: an analysis of 1,132 twins

    Directory of Open Access Journals (Sweden)

    Sara Domingues

    2015-02-01

    Full Text Available Background: Multiple pregnancies have increased significantly over the past decades. Birth weight discordance (BWD is a common problem between twins, but its association with an increased morbidity and mortality is still unclear. The aim of this study was to determine the frequency of BWD among twins and to evaluate its impact on perinatal morbidity.Methods: Retrospective study of 1,132 twins born in a tertiary perinatal center, over a period of 8 years (2003-2010, that were divided in two groups: concordant (intrapair birth weight difference ≤ 20% or discordant (> 20%. The two groups were compared in terms of epidemiological and obstetric data, mode of delivery, perinatal morbidity and mortality.Results: During the study period, multiple gestation occurred in 2% of cases, of which 96% were twins. BWD was found in 212 (19% twins. Multivariate analysis demonstrated that maternal age ≥ 35 years and hypoxic-ischemic placental infarction were risk factors for the occurrence of BWD. The discordant group showed a significantly higher incidence of congenital skeletal and central nervous system malformations, a higher rate of hospitalization in the neonatal intensive care unit and a longer duration of hospitalization. The percentage of those requiring assisted ventilation, pulmonary surfactant, parenteral nutrition and central venous catheters was significantly higher in the discordant group compared with the concordant one. The rate of stillbirth was significantly higher in the discordant group (3% versus 1%; mortality was also higher (3% versus 2%, but this difference was not statistically significant (p = 0.405.Conclusion: BWD was associated with increased prenatal mortality and neonatal morbidity. Diagnosis and management of pregnant women with this fetal condition in tertiary perinatal centers may improve the prognosis of these infants.

  16. Brain Activation during Memory Encoding in Type 2 Diabetes Mellitus: A Discordant Twin Pair Study

    OpenAIRE

    Wood, Amanda G.; Jian Chen; Christopher Moran; Thanh Phan; Richard Beare; Kimberley Cooper; Stacey Litras; Velandai Srikanth

    2016-01-01

    Type 2 diabetes mellitus increases the risk of dementia and neuronal dysfunction may occur years before perceptible cognitive decline. We aimed to study the impact of type 2 diabetes on brain activation during memory encoding in middle-aged people, controlling for age, sex, genes, and early-shared environment. Twenty-two twin pairs discordant for type 2 diabetes mellitus (mean age 60.9 years) without neurological disease were recruited from the Australian Twin Registry (ATR) and underwent fun...

  17. [Prenatal diagnosis of five cases of monochorionic-diamniotic twins discordant for karyotype analysis].

    Science.gov (United States)

    Wu, Jianzhu; Zhou, Yi; Lin, Shaobin; Chen, Baojiang; Xie, Yingjun

    2015-10-01

    OBJECTIVE To explore the mechanism and diagnostic method for monochorionic-diamniotic twins discordant for karyotype analysis. METHODS Dual amniocentesis was performed on five pairs of monochorionic-diamniotic twins, which all consisted of a normal twin and one with multiple malformations revealed by ultrasound. Karyotype analysis was performed on amniocytes derived from each of the twins. Zygosity was also determined with DNA extracted from amniocytes with 16 polymorphic microsatellite markers. RESULTS Three cases of 45,X, one case of 47,XX,+9 and one case of 47,XY,+18 were detected among the abnormal twins, while the normal fetuses all had a normal karyotype. DNA analysis suggested that, in all cases, the twins have shared the 16 polymorphic microsatellite markers, which confirmed their monozygosity. CONCLUSION Monochorionic-diamniotic twins may be discordant for karyotyping, for which anaphase lagging, chromosomal non-disjunction and trisomy rescue may be the underlying reasons. As a simple method, dual amniocentesis can be used to obtain amniotic fluid samples for karyotype analysis and determination of zygosity for such twins. PMID:26418994

  18. Phospholipids and insulin resistance in psychosis: a lipidomics study of twin pairs discordant for schizophrenia

    OpenAIRE

    Orešič, Matej; Seppänen-Laakso, Tuulikki; Sun, Daqiang; Tang, Jing; Therman, Sebastian; Viehman, Rachael; Mustonen, Ulla; van Erp, Theo G.; Hyötyläinen, Tuulia; Thompson, Paul; Toga, Arthur W.; Huttunen, Matti O.; Suvisaari, Jaana; Kaprio, Jaakko; Lönnqvist, Jouko

    2012-01-01

    Background Several theories have been proposed to conceptualize the pathological processes inherent to schizophrenia. The 'prostaglandin deficiency' hypothesis postulates that defective enzyme systems converting essential fatty acids to prostaglandins lead to diminished levels of prostaglandins, which in turn affect synaptic transmission. Methods Here we sought to determine the lipidomic profiles associated with schizophrenia in twin pairs discordant for schizophrenia as well as unaffected tw...

  19. Phospholipids and insulin resistance in psychosis: a lipidomics study of twin pairs discordant for schizophrenia

    OpenAIRE

    Orešič, Matej; Seppänen-Laakso, Tuulikki; Sun, Daqiang; Tang, Jing; Therman, Sebastian; Viehman, Rachael; Mustonen, Ulla; van Erp, Theo G.; Hyötyläinen, Tuulia; Thompson, Paul; Toga, Arthur W.; Huttunen, Matti O.; Suvisaari, Jaana; Kaprio, Jaakko; Lönnqvist, Jouko

    2012-01-01

    Abstract Background Several theories have been proposed to conceptualize the pathological processes inherent to schizophrenia. The 'prostaglandin deficiency' hypothesis postulates that defective enzyme systems converting essential fatty acids to prostaglandins lead to diminished levels of prostaglandins, which in turn affect synaptic transmission. Methods Here we sought to determine the lipidomic profiles associated with schizophrenia in twin pairs discordant for schizophr...

  20. Differentially Methylated Genomic Regions in Birth-Weight Discordant Twin Pairs

    DEFF Research Database (Denmark)

    Chen, Mubo; Baumbach, Jan; Vandin, Fabio;

    2016-01-01

    twin pairs to find evidence for such “programming” effects, but no significant results emerged. We further investigated this issue using a new computational approach: Instead of probing single genomic sites for significant alterations in epigenetic marks, we scan for differentially methylated genomic......Poor nutrition during critical growth phases may alter the structural and physiologic development of vital organs thus “programming” the susceptibility to adult-onset diseases and disease-related health conditions. Epigenome-wide association studies have been performed in birth-weight discordant...... regions. Whole genome DNA methylation levels were measured in whole blood from 150 pairs of adult identical twins discordant for birth-weight. Intrapair differential DNA methylation was associated with qualitative (large or small) and quantitative (percentage) birth-weight discordance at each genomic site...

  1. Discordance for Cri du Chat Syndrome in a dichorionic–diamniotic twin pregnancy

    Directory of Open Access Journals (Sweden)

    Mireia González-Comadran

    2015-07-01

    Full Text Available We report on the prenatal diagnosis through array CGH of a dichorionic–diamniotic (DC/DA twins discordant for Cri du Chat Syndrome. Structural anomalies on one of the twins lead to amniotic fluid sampling, which revealed a partial deletion on the short arm of the chromosome 5. Selective feticide of the affected twin was performed at 34 + 1 weeks' and elective Cesarean section at 37 + 2 weeks. Postnatal cytogenetic analysis confirmed pre-natal genetic findings.

  2. Discordance for Cri du Chat Syndrome in a dichorionic–diamniotic twin pregnancy

    OpenAIRE

    Mireia González-Comadran; José Luís Hernández Sánchez; Carolina Rueda; Elena Ferriols; Maria Prat; Ricardo Rubio; Ramón Carreras

    2015-01-01

    We report on the prenatal diagnosis through array CGH of a dichorionic–diamniotic (DC/DA) twins discordant for Cri du Chat Syndrome. Structural anomalies on one of the twins lead to amniotic fluid sampling, which revealed a partial deletion on the short arm of the chromosome 5. Selective feticide of the affected twin was performed at 34 + 1 weeks' and elective Cesarean section at 37 + 2 weeks. Postnatal cytogenetic analysis confirmed pre-natal genetic findings.

  3. Heritability of thyroid peroxidase autoantibody levels in type 1 diabetes: evidence from discordant twin pairs

    Science.gov (United States)

    Wang, Bin; Hawa, Mohammed I.; Rijsdijk, Frühling V.; Fain, Pamela R.; Paschou, Stavroula A.; Boehm, Bernhard O.; Steck, Andrea K.; Snieder, Harold

    2016-01-01

    Aims/hypothesis The discordance status of (autoimmune) type 1 diabetes within monozygotic twin pairs points to the importance of environmental factors. The aim of this study was to investigate whether the environmental events causing type 1 diabetes influence thyroid autoimmunity. Methods Monozygotic and dizygotic twins discordant for type 1 diabetes from the UK and USA were tested for thyroid peroxidase autoantibodies (TPOA) by radioimmunoassay. Using quantitative genetic model fitting of a liability-threshold model we estimated the contribution of genetic (heritability) and environmental factors to TPOA. Results TPOA positivity was higher in females than in males in both cohorts and was associated with later age at diagnosis in the UK and combined cohorts (p0.2 in all groups). The best-fitting models showed heritability (95% CI) estimates for TPOA of 63% (37%, 80%) for the UK and 80% (51%, 92%) for US twins, while the best-fitting meta-analysis model of the two twin cohorts combined included additive genetic and unique environmental factors with a heritability estimate of 69% (50%, 82%). Conclusions/interpretation Risk of thyroid autoimmunity, defined by TPOA, in the context of autoimmune diabetes is, substantially, genetically determined in discordant twin pairs. Environmental factors leading to type 1 diabetes were not the same as those involved with thyroid autoimmunity. It follows that it is as important to investigate for thyroid autoimmunity in relatives of type 1 diabetes patients as it is in the patients themselves. PMID:26070305

  4. Quality of life in unaffected twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Vinberg, Maj; Bech, Per; Kyvik, Kirsten Ohm;

    2006-01-01

    -Risk twins) and without (the control group/Low-Risk twins) a co-twin history of affective disorder were identified through nationwide registers. The aim of the present study was to investigate the hypothesis that a genetic liability to affective disorder is associated with a lower perception of quality...... might be due to the genetic liability to affective disorder. These findings need to be replicated in future family studies.......BACKGROUND: The disability and hardship associated with affective disorder is shared by the family members of affective patients and might affect the family member's quality of life. METHOD: In a cross-sectional, high-risk, case-control study, monozygotic (MZ) and dizygotic (DZ) twins with (High...

  5. Risk of chronic bronchitis in twin pairs discordant for smoking

    DEFF Research Database (Denmark)

    Meteran, Howraman; Thomsen, Simon Francis; Harmsen, Lotte;

    2012-01-01

    It is well known that smoking is a major risk factor for lung disease and respiratory symptoms. We examined the association between smoking and the risk of chronic bronchitis in a large twin sample....

  6. Recurrence risk for offspring of twins discordant for oral cleft: a population-based cohort study of the Danish 1936-2004 cleft twin cohort

    DEFF Research Database (Denmark)

    Grosen, Dorthe; Bille, Camilla; Pedersen, Jacob Krabbe; Skytthe, Axel; Murray, Jeffrey C; Christensen, Kaare

    Our objective in this Danish population-based cohort study was to estimate the recurrence risk of isolated oral cleft (OC) for offspring of the unaffected co-twins of OC discordant twin pairs and to compare this risk to the recurrence risk in the offspring of the affected co-twin as well as to the...... risk in the background population. During 1936-2004, 207 twin pairs were ascertained, among whom at least one twin had an OC. The index persons were twins discordant for OC who had children (N=117), and their offspring (N=239). The participants were ascertained by linkage between The Danish Facial...... Cleft Database, The Danish Twin Registry and The Danish Civil Registration System. In the study OC recurrence risk for offspring of the affected and unaffected twin and relative risk were compared to the background prevalence. We found that among 110 children of the 54 OC affected twins, two (1...

  7. Gray and white matter volume abnormalities in monozygotic and same-gender dizygotic twins discordant for schizophrenia

    DEFF Research Database (Denmark)

    Hilshoff, Hilleke E.; Brans, Rachel G. H.; van Haren, Neeltje E. M.; Schnack, Hugo G.; Langen, Marieke; Baare, Wim F.C.; van Oel, Clarine J.; Kahn, Rene S.

    2004-01-01

    gray or white matter volume change is not known. METHODS: Magnetic resonance imaging (1.5 T) brain scans of 11 monozygotic and 11 same-gender dizygotic twin pairs discordant for schizophrenia were acquired and compared with 11 monozygotic and 11 same-gender dizygotic healthy control twin pairs. RESULTS......: Repeated-measures volume analysis of covariance revealed decreased whole brain volume in the patients with schizophrenia as compared with their co-twins and with healthy twin pairs. Decreased white matter volume was found in discordant twin pairs compared with healthy twin pairs, particularly in the...... monozygotic twin pairs. A decrease in gray matter was found in the patients compared with their co-twins and compared withthe healthy twins. CONCLUSIONS: The results suggest that the decreases in white matter volume reflect the increased genetic risk to develop schizophrenia, whereas the decreases in gray...

  8. Differentially Methylated Genomic Regions in Birth-Weight Discordant Twin Pairs.

    Science.gov (United States)

    Chen, Mubo; Baumbach, Jan; Vandin, Fabio; Röttger, Richard; Barbosa, Eudes; Dong, Mingchui; Frost, Morten; Christiansen, Lene; Tan, Qihua

    2016-03-01

    Poor nutrition during critical growth phases may alter the structural and physiologic development of vital organs thus "programming" the susceptibility to adult-onset diseases and disease-related health conditions. Epigenome-wide association studies have been performed in birth-weight discordant twin pairs to find evidence for such "programming" effects, but no significant results emerged. We further investigated this issue using a new computational approach: Instead of probing single genomic sites for significant alterations in epigenetic marks, we scan for differentially methylated genomic regions. Whole genome DNA methylation levels were measured in whole blood from 150 pairs of adult identical twins discordant for birth-weight. Intrapair differential DNA methylation was associated with qualitative (large or small) and quantitative (percentage) birth-weight discordance at each genomic site using regression models adjusting for age and sex. Based on the regression results, genomic regions with consistent alteration patterns of DNA methylation were located and tested for significant robustness using computational permutation tests. This yielded an interesting genomic region on chromosome 1, which is significantly differentially methylated for quantitative birth-weight discordance. The region covers two genes (TYW3 and CRYZ) both reportedly associated with metabolism. We conclude that prenatal conditions for birth-weight discordance may result in persistent epigenetic modifications potentially affecting even adult health. PMID:26831219

  9. Perinatal Outcome of Discordant Anomalous Twins: A Single-Center Experience in a Developing Country.

    Science.gov (United States)

    Fernandes, Tatiana R M M; Carvalho, Paulo R N; Flosi, Fernanda B; Baião, Ana Elisa R; Junior, Sant Claire G

    2016-08-01

    A dramatic increase in twin pregnancies has been observed in the past few decades, primarily related to assisted reproductive techniques (ART) and increased average maternal age during pregnancy. Multiple pregnancies, compared to singleton pregnancies, are associated with greater perinatal morbidity and mortality. The present study evaluated the perinatal outcomes of pregnancies with discordant anomalous twins in a tertiary maternity ward in a developing country. Data were retrospectively collected from the Instituto Fernandes Figueira/FIOCRUZ, Brazil between January 2002 and December 2014. We identified 74 twin pregnancies with discordant anomalous twins. Final data analysis was based on 40 pregnancies. Congenital defects were classified according to the International Classification of Diseases: ICD-10: the digestive system was responsible in 27 (34%) cases; the central nervous system was responsible in 18 (22%) cases; the urinary tract was responsible in 14 (17%) cases; and the circulatory system was responsible in 14 (17%) cases. A total of 19 deaths occurred during the study period, and delivery before 30.4 weeks was a significant prediction of fetal death (p = .01). The presence of hydrops in the affected fetus was related to a higher number of deaths in healthy fetuses and contributed to a worse prognosis. The presence of this condition was the cause of 12 (55.6%) deaths in healthy fetuses. A 10 times higher risk of death of a normal co-twin was observed in cases of death of the anomalous twin (p = .002, OR 10.55, 95% CI: 1.9-58.52). PMID:27321141

  10. Metabolome and fecal microbiota in monozygotic twin pairs discordant for weight: a Big Mac challenge.

    Science.gov (United States)

    Bondia-Pons, Isabel; Maukonen, Johanna; Mattila, Ismo; Rissanen, Aila; Saarela, Maria; Kaprio, Jaakko; Hakkarainen, Antti; Lundbom, Jesper; Lundbom, Nina; Hyötyläinen, Tuulia; Pietiläinen, Kirsi H; Orešič, Matej

    2014-09-01

    Postprandial responses to food are complex, involving both genetic and environmental factors. We studied postprandial responses to a Big Mac meal challenge in monozygotic co-twins highly discordant for body weight. This unique design allows assessment of the contribution of obesity, independent of genetic liability. Comprehensive metabolic profiling using 3 analytical platforms was applied to fasting and postprandial serum samples from 16 healthy monozygotic twin pairs discordant for weight (body mass index difference >3 kg/m(2)). Nine concordant monozygotic pairs were examined as control pairs. Fecal samples were analyzed to assess diversity of the major bacterial groups by using 5 different validated bacterial group specific denaturing gradient gel electrophoresis methods. No differences in fecal bacterial diversity were detected when comparing co-twins discordant for weight (ANOVA, P<0.05). We found that within-pair similarity is a dominant factor in the metabolic postprandial response, independent of acquired obesity. Branched chain amino acids were increased in heavier as compared with leaner co-twins in the fasting state, but their levels converged postprandially (paired t tests, FDR q<0.05). We also found that specific bacterial groups were associated with postprandial changes of specific metabolites. Our findings underline important roles of genetic and early life factors in the regulation of postprandial metabolite levels. PMID:24846387

  11. Hypomethylation within gene promoter regions and type 1 diabetes in discordant monozygotic twins.

    Science.gov (United States)

    Elboudwarej, Emon; Cole, Michael; Briggs, Farren B S; Fouts, Alexandra; Fain, Pamela R; Quach, Hong; Quach, Diana; Sinclair, Elizabeth; Criswell, Lindsey A; Lane, Julie A; Steck, Andrea K; Barcellos, Lisa F; Noble, Janelle A

    2016-04-01

    Genetic susceptibility to type 1 diabetes (T1D) is well supported by epidemiologic evidence; however, disease risk cannot be entirely explained by established genetic variants identified so far. This study addresses the question of whether epigenetic modification of the inherited DNA sequence may contribute to T1D susceptibility. Using the Infinium HumanMethylation450 BeadChip array (450k), a total of seven long-term disease-discordant monozygotic (MZ) twin pairs and five pairs of HLA-identical, disease-discordant non-twin siblings (NTS) were examined for associations between DNA methylation (DNAm) and T1D. Strong evidence for global hypomethylation of CpG sites within promoter regions in MZ twins with TID compared to twins without T1D was observed. DNA methylation data were then grouped into three categories of CpG sites for further analysis, including those within: 1) the major histocompatibility complex (MHC) region, 2) non-MHC genes with reported T1D association through genome wide association studies (GWAS), and 3) the epigenome, or remainder of sites that did not include MHC and T1D associated genes. Initial results showed modest methylation differences between discordant MZ twins for the MHC region and T1D-associated CpG sites, BACH2, INS-IGF2, and CLEC16A (DNAm difference range: 2.2%-5.0%). In the epigenome CpG set, the greatest methylation differences were observed in MAGI2, FANCC, and PCDHB16, (DNAm difference range: 6.9%-16.1%). These findings were not observed in the HLA-identical NTS pairs. Targeted pyrosequencing of five candidate CpG loci identified using the 450k array in the original discordant MZ twins produced similar results using control DNA samples, indicating strong agreement between the two DNA methylation profiling platforms. However, findings for the top five candidate CpG loci were not replicated in six additional T1D-discordant MZ twin pairs. Our results indicate global DNA hypomethylation within gene promoter regions may contribute to T

  12. Phospholipids and insulin resistance in psychosis: A lipidomics study of twin pairs discordant for schizophrenia

    OpenAIRE

    Orešič, M.; Seppänen-Laakso, T; Sun, D; Tang, J.; Therman, S; Viehman, R; Mustonen, U; van Erp, TG; T. Hyötyläinen; Thompson, P; Toga, AW; Huttunen, MO; Suvisaari, J.; Kaprio, J.; Lönnqvist, J

    2012-01-01

    Background: Several theories have been proposed to conceptualize the pathological processes inherent to schizophrenia. The 'prostaglandin deficiency' hypothesis postulates that defective enzyme systems converting essential fatty acids to prostaglandins lead to diminished levels of prostaglandins, which in turn affect synaptic transmission.Methods: Here we sought to determine the lipidomic profiles associated with schizophrenia in twin pairs discordant for schizophrenia as well as unaffected t...

  13. Cultured gut microbiota from twins discordant for obesity modulate adiposity and metabolic phenotypes in mice

    OpenAIRE

    Ridaura, Vanessa K.; Faith, Jeremiah J.; Rey, Federico E.; Cheng, Jiye; Duncan, Alexis E.; Kau, Andrew L.; Griffin, Nicholas W.; Lombard, Vincent; Henrissat, Bernard; Bain, James R.; Muehlbauer, Michael J; Ilkayeva, Olga; Semenkovich, Clay F.; Funai, Katsuhiko; Hayashi, David K.

    2013-01-01

    The role of specific gut microbes in shaping body composition remains unclear. We transplanted fecal microbiota from adult female twin pairs discordant for obesity into germ-free mice fed low-fat mouse chow, as well as diets representing different levels of saturated fat and fruit and vegetable consumption typical of the USA. Increased total body and fat mass, as well as obesity-associated metabolic phenotypes were transmissible with uncultured fecal communities, and with their corresponding ...

  14. Asthma Discordance in Twins Is Linked to Epigenetic Modifications of T Cells

    OpenAIRE

    R Scott Runyon; Cachola, Leslie M; Nitya Rajeshuni; Tessa Hunter; Marco Garcia; Regina Ahn; Fred Lurmann; Ruth Krasnow; Jack, Lisa M.; Miller, Rachel L.; Gary E. Swan; Arunima Kohli; Amanda C Jacobson; Nadeau, Kari C.

    2012-01-01

    T cells mediate the inflammatory responses observed in asthma among genetically susceptible individuals and have been suspected to be prone to epigenetic regulation. However, these relationships are not well established from past clinical studies that have had limited capacity to control for the effects of variable genetic predisposition and early environmental exposures. Relying on a cohort of monozygotic twins discordant for asthma we sought to determine if epigenetic modifications in T cel...

  15. Phospholipids and insulin resistance in psychosis: a lipidomics study of twin pairs discordant for schizophrenia

    OpenAIRE

    Orešič, M; Seppänen-Laakso, T; Sun, D; Tang, J.; Therman, S; Viehman, R; Mustonen, U; Van Erp, TG; T. Hyötyläinen; Thompson, P.; Toga, AW; Huttunen, MO; Suvisaari, J; Kaprio, J.; Lönnqvist, J.

    2012-01-01

    Background: Several theories have been proposed to conceptualize the pathological processes inherent to schizophrenia. The 'prostaglandin deficiency' hypothesis postulates that defective enzyme systems converting essential fatty acids to prostaglandins lead to diminished levels of prostaglandins, which in turn affect synaptic transmission.Methods: Here we sought to determine the lipidomic profiles associated with schizophrenia in twin pairs discordant for schizophrenia as well as unaffected t...

  16. Twinsters the Movie: Reared Apart Twins in Real Time/Research Reviews: Heteropagus Twin; Schizophrenia Liability; Twin Study of Epigenetics and Homosexuality; Transgender-Discordant Twins/In the News: The Passing of Jack Yufe; An Unusual Twin Father; Identical Twin Models I; Identical Twin Models II; Twin Marines of World War II.

    Science.gov (United States)

    Segal, Nancy L

    2016-02-01

    The 2015 documentary film Twinsters, tells the story of reared-apart MZ female twins, Samantha (Sam) Futerman and Anaïs Bordier. Born in South Korea, the twins were adopted separately as babies by couples living in the United States (Sam) and France (Anaïs). Their chance discovery of one another and their subsequent reunion and relationship are beautifully captured in the 2015 documentary film, Twinsters. Recent interviews with some of their family members are presented in Twin Research and Human Genetics for the first time. This is followed by brief reviews of recent twin research on a heteropagus twin, schizophrenia liability, epigenetics and homosexuality, and transgender-discordant twins. Finally, some newsworthy items are summarized, including the passing of reared-apart MZ twin Jack Yufe, an unusual twin father; identical twin models I; identical twin models II; and a pair of twin marines. PMID:26810868

  17. Mitochondrial DNA Copy Number in Sleep Duration Discordant Monozygotic Twins

    DEFF Research Database (Denmark)

    Wrede, Joanna E; Mengel-From, Jonas; Buchwald, Dedra;

    2015-01-01

    STUDY OBJECTIVES: Mitochondrial DNA (mtDNA) copy number is an important component of mitochondrial function and varies with age, disease, and environmental factors. We aimed to determine whether mtDNA copy number varies with habitual differences in sleep duration within pairs of monozygotic twins...... twin. Fasting peripheral blood leukocyte DNA was assessed for mtDNA copy number via the n-fold difference between qPCR measured mtDNA and nuclear DNA creating an mtDNA measure without absolute units. We used generalized estimating equation linear regression models accounting for the correlated data...... structure to assess within-pair effects of sleep duration on mtDNA copy number. MEASUREMENTS AND RESULTS: Mean within-pair sleep duration difference per 24 hours was 94.3 minutes (SD 62.6 min). We found reduced sleep duration (β = 0.06; 95% CI 0.004, 0.12; P < 0.05) and sleep efficiency (β = 0.51; 95% CI 0...

  18. Bronchial reactivity and allergy-promoting factors in monozygotic twins discordant for allergic rhinitis.

    Science.gov (United States)

    Ericsson, C H; Svartengren, M; Mossberg, B; Pedersen, N; Camner, P

    1991-07-01

    Bronchial reactivity was studied twice in eight monozygotic twin pairs discordant for allergic rhinitis with pollen hypersensitivity, during the winter season (all eight pairs) and during the pollen season (seven pairs). On both occasions, the allergic twins showed significantly higher reactivity than their nonallergic siblings. The results indicate that moderate allergic rhinitis is associated with increased bronchial reactivity. This increased reactivity is an acquired trait; however, bronchial reactivity is not constantly increased in pollen rhinitis and may be normal even during the pollen season. The symptoms of allergic rhinitis usually started in childhood before the separation of the siblings. We could not demonstrate any major differences in exposure to allergens or airway irritants between the siblings. The allergic twins tended to have lower birth weight and insufficient weight increase just after birth. PMID:1859042

  19. College-age twins: university admission policies / twin research: birth weight and neuromotor performance; transfusion syndrome markers; vanishing twins and fetal sex determination; mz twin discordance for wilson's disease / media: big at birth; planned separation of conjoined twins; x factor twins; Cinema: the identical.

    Science.gov (United States)

    Segal, Nancy L

    2014-12-01

    There is a lack of research findings addressing the unique college admissions issues faced by twins and other multiples. The advantages and disadvantage twins face, as reported by college administrators, twins and families are reviewed. Next, recent research addressing twins' birth weight and neuromotor performance, transfusion syndrome markers, the vanishing twin syndrome and monozygotic (MZ) twin discordance for Wilson's disease is described. News items concerning the birth of unusually large twins, the planned separation of conjoined twins, twin participants in the X Factor games and a film, The Identical, are also summarized. PMID:25331364

  20. Candidate region linkage analysis in twins discordant or concordant for depression symptomatology

    DEFF Research Database (Denmark)

    Christiansen, Lene; Tan, Q; Kruse, T A; McGue, M; Christensen, Kaare

    common susceptibility locus in affective disorders on chromosome 12q24. In this study we investigated the chromosome 12 candidate region for linkage to the mean level of depression symptomatology, over a 10-year follow-up, using a highly informative sample of concordant and discordant twin pairs selected......Genetic risk factors contribute considerably to both clinical affective disorders and subsyndromal mood level. There is moreover evidence to suggest that the genetic basis of bipolar disorder and unipolar depression overlap to some extent, and several linkage analyses have suggested evidence for a...

  1. Non-random X chromosome inactivation in an affected twin in a monozygotic twin pair discordant for Wiedemann-Beckwith syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Oestavik, R.E.; Eiklid, K.; Oerstavik, K.H. [Ulleval Univ. Hospital, Oslo (Norway)] [and others

    1995-03-27

    Wiedemann-Beckwith syndrome (WBS) is a syndrome including exomphalos, macroglossia, and generalized overgrowth. The locus has been assigned to 11p15, and genomic imprinting may play a part in the expression of one or more genes involved. Most cases are sporadic. An excess of female monozygotic twins discordant for WBS have been reported, and it has been proposed that this excess could be related to the process of X chromosome inactivation. We have therefore studied X chromosome inactivation in 13-year-old monozygotic twin girls who were discordant for WBS. In addition, both twins had Tourette syndrome. The twins were monochorionic and therefore the result of a late twinning process. This has also been the case in previously reported discordant twin pairs with information on placentation. X chromosome inactivation was determined in DNA from peripheral blood cells by PCR analysis at the androgen receptor locus. The affected twin had a completely skewed X inactivation, where the paternal allele was on the active X chromosome in all cells. The unaffected twin had a moderately skewed X inactivation in the same direction, whereas the mother had a random pattern. Further studies are necessary to establish a possible association between the expression of WBS and X chromosome inactivation. 18 refs., 2 figs., 1 tab.

  2. Cloaca in Discordant Monoamniotic Twins: Prenatal Diagnosis and Consequence for Fetal Lung Development

    Directory of Open Access Journals (Sweden)

    Yvon Chitrit

    2014-05-01

    Full Text Available Objective - Describe a case of cloaca prenatally diagnosed in one of a set of monoamniotic twins. Study Design - Retrospective review of a case. Results - Cloaca is one of the most complex and severe degrees of anorectal malformations in girls. We present a discordant cloaca in monoamniotic twins. Fetal ultrasound showed a female fetus with a pelvic midline cystic mass, a phallus-like structure, a probable anorectal atresia with absence of anal dimple and a flat perineum, and renal anomalies. The diagnosis was confirmed by fetal magnetic resonance imaging postnatally. Conclusions - The rarity of the malformation in a monoamniotic pregnancy, the difficulties of prenatal diagnosis, the pathogenic assumptions, and the consequences of adequate amniotic fluid for fetal lung development are discussed.

  3. Cloaca in discordant monoamniotic twins: prenatal diagnosis and consequence for fetal lung development.

    Science.gov (United States)

    Chitrit, Yvon; Vuillard, Edith; Khung, Sunavy; Belarbi, Nadia; Guimiot, Fabien; Muller, Francoise; Ghoneimi, Alaa El; Oury, Jean Francois

    2014-05-01

    Objective Describe a case of cloaca prenatally diagnosed in one of a set of monoamniotic twins. Study Design Retrospective review of a case. Results Cloaca is one of the most complex and severe degrees of anorectal malformations in girls. We present a discordant cloaca in monoamniotic twins. Fetal ultrasound showed a female fetus with a pelvic midline cystic mass, a phallus-like structure, a probable anorectal atresia with absence of anal dimple and a flat perineum, and renal anomalies. The diagnosis was confirmed by fetal magnetic resonance imaging postnatally. Conclusions The rarity of the malformation in a monoamniotic pregnancy, the difficulties of prenatal diagnosis, the pathogenic assumptions, and the consequences of adequate amniotic fluid for fetal lung development are discussed. PMID:25032057

  4. Epigenome-wide association study on identical twins discordant for birth weight

    DEFF Research Database (Denmark)

    Tan, Qihua; Nielsen, Morten Frost Munk; Christiansen, Lene

    induces persistent epigenetic modification detectable at adult ages, we performed a genome-wide DNA methylation profiling in peripheral blood of 150 pairs of identical Danish twins discordant for birth weight using the Illumina Infinium HumanMethylation450 BeadChip featuring 485,000 CpG sites across the...... genome. After quality control and data preprocessing using free R package minfi, data were analysed by a mixed effects model including fixed effect variables such as birth weight difference, age and sex of twin pairs; random effect variables such as batch, well, and sample position on the array, etc......Epidemiological evidences have shown that early life exposure to adverse environment, e.g. bad nutrition, and stress during pregnancy of mother which usually resulting in low birth weight, could have long-term health consequences including metabolic disorders, diabetes, hypertension, and even...

  5. Variations in genome-wide gene expression in identical twins – a study of primary osteoblast-like culture from female twins discordant for osteoporosis

    Directory of Open Access Journals (Sweden)

    Beresford Jon N

    2004-06-01

    Full Text Available Abstract Background Monozygotic twin pairs who are genetically identical would be potentially useful in gene expression study for specific traits as cases and controls, because there would be much less gene expression variation within pairs compared to two unrelated individuals. However the twin pair has to be discordant for the particular trait or phenotype excluding those resulting from known confounders. Such discordant monozygotic twin pairs are rare and very few studies have explored the potential usefulness of this approach. Results We studied genome-wide gene expression in primary osteoblast-like culture from marrow aspirates obtained from three pairs of monozygotic twins. We used the latest Affymetrix microchip contains probe sets for more than 20,000 genes. Two pairs were discordant for bone mineral density at the hip by more than one standard deviation, and the third pair was unrelated concordant and used as control. Only 1.5% on average of genes showed variation in expression within pairs as compared to 5% between pairs or over 15% from the literature. Importantly we identified several groups of genes showing variations within the discordant pairs and not within the concordant pair such as chondroitin beta 1,4 N-acetylgalactosaminyltransferase, inhibin beta A, interleukin 1 beta and colony stimulating factor 1 macrophage. These genes are known to have potential roles in bone physiology relating to bone density, osteoporosis and osteoarthritis. Conclusion Using the example of osteoblast-like cells in our monozygotic discordant twins for osteoporosis, we identified genes showing differential expression. Although without further experiment, we cannot confirm or conclude these are genes definitely related to bone physiology, we believe we have shown the potential and cost-effectiveness of further gene expression studies in discordant monozygotic twin pairs. A replication study for confirmation is essential.

  6. Discordancia de peso al nacer: consecuencias y su perdurabilidad en el desarrollo psicológico del gemelo de menor peso intrapar (Intertwin birth weight discordance: its effects and their persistence in the psychological development of the lightest intrapair twin)

    OpenAIRE

    Elena Escolano-Pérez

    2015-01-01

    More twins are being born with intrapair birth weight discordances. Discordance in birth weight is a risk factor that can affect the development of twins, especially that of the lightest twin. However, few studies have analysed the possible consequences of birth weight discordance on the lightest twin beyond possible neonatal obstetric problems. Thus,little is known about the consequences of birth weight discordance on the psychological development of such babies.This article reviews the lite...

  7. Insulin secretion, insulin action, and hepatic glucose production in identical twins discordant for non-insulin-dependent diabetes mellitus.

    OpenAIRE

    Vaag, A.; Henriksen, J E; Madsbad, S; Holm, N; Beck-Nielsen, H.

    1995-01-01

    12 identical twin pairs discordant for non-insulin-dependent diabetes mellitus (NIDDM) were studied for insulin sensitivity (euglycemic insulin clamp, 40 mU/m2 per min), hepatic glucose production (HGP, [3-3H]glucose infusion), and insulin secretion (oral glucose tolerance test and hyperglycemic [12 mM] clamp, including glucagon administration). Five of the nondiabetic twins had normal and seven had impaired glucose tolerance. 13 matched, healthy subjects without a family history of diabetes ...

  8. Tests of a Direct Effect of Childhood Abuse on Adult Borderline Personality Disorder Traits: A Longitudinal Discordant Twin Design

    OpenAIRE

    Bornovalova, Marina A.; Huibregtse, Brooke M; Hicks, Brian M.; Keyes, Margaret; McGue, Matt; Iacono, William

    2012-01-01

    We used a longitudinal twin design to examine the causal association between sexual, emotional, and physical abuse in childhood (before age 18) and borderline personality disorder (BPD) traits at age 24 using a discordant twin design and biometric modeling. Additionally, we examined the mediating and moderating effects of symptoms of childhood externalizing and internalizing disorders on the link between childhood abuse and BPD traits. Although childhood abuse, BPD traits, and internalizing a...

  9. Arteriosclerosis of carotid arteries in identical twins discordant in tobacco smoking

    International Nuclear Information System (INIS)

    Duplex Doppler US has proved to be an accurate method of evaluating the arteriosclerotic process in extracranial carotid arteries. Tobacco smoking is generally considered to be a factor promoting arteriosclerosis. The authors performed duplex US examinations of the carotid arteries of 48 pairs (96 individuals) of monozygotic twins discordant for smoking. The ages of the examinees ranged from 31 years to 77 years (mean, 52 years). Doppler measurements of femoral and popliteal arteries were also made. A difference in the grade of arteriosclerosis was perceived in 40 pairs of twins, in each case to the benefit of the nonsmoker. The most common change was a difference in intimal thickness. Carotid artery stenoses, 15%-60%, were found in seven cases. In addition, a difference in the size of minor plaques of the carotid bifurcations was verified in 26 pairs of twins. Three smokers were found to have an obstructive lesion in the lower extremity arteries. Arteriosclerotic changes were more common and more pronounced in smokers with a long exposure to tobacco

  10. Pyrosequencing of Plaque Microflora In Twin Children with Discordant Caries Phenotypes.

    Directory of Open Access Journals (Sweden)

    Meng Zhang

    Full Text Available Despite recent successes in the control of dental caries, the mechanism of caries development remains unclear. To investigate the causes of dental decay, especially in early childhood caries, the supragingival microflora composition of 20 twins with discordant caries phenotypes were analyzed using high-throughput pyrosequencing. In addition, the parents completed a lifestyle questionnaire. A total of 228,789 sequencing reads revealed 10 phyla, 84 genera, and 155 species of microflora, the relative abundances of these strains varied dramatically among the children, Comparative analysis between groups revealed that Veillonella, Corynebacterium and Actinomyces were presumed to be caries-related genera, Fusobacterium, Kingella and Leptotrichia were presumed to be healthy-related genus, yet this six genera were not statistically significant (P>0.05. Moreover, a cluster analysis revealed that the microbial composition of samples in the same group was often dissimilar but that the microbial composition observed in twins was usually similar. Although the genetic and environmental factors that strongly influence the microbial composition of dental caries remains unknown, we speculate that genetic factors primarily influence the individual's susceptibility to dental caries and that environmental factors primarily regulate the microbial composition of the dental plaque and the progression to caries. By using improved twins models and increased sample sizes, our study can be extended to analyze the specific genetic and environmental factors that affect the development of caries.

  11. Failure to Identify Somatic Mutations in Monozygotic Twins Discordant for Schizophrenia by Whole Exome Sequencing

    Institute of Scientific and Technical Information of China (English)

    Nan Lyu; Li-Li Guan; Hong Ma; Xi-Jin Wang; Bao-Ming Wu; Fan-Hong Shang; Dan Wang

    2016-01-01

    Background:Schizophrenia (SCZ) is a severe,debilitating,and complex psychiatric disorder with multiple causative factors.An increasing number of studies have determined that rare variations play an important role in its etiology.A somatic mutation is a rare form of genetic variation that occurs at an early stage of embryonic development and is thought to contribute substantially to the development of SCZ.The aim of the study was to explore the novel pathogenic somatic single nucleotide variations (SNVs) and somatic insertions and deletions (indels) of SCZ.Methods:One Chinese family with a monozygotic (MZ) twin pair discordant for SCZ was included.Whole exome sequencing was performed in the co-twin and their parents.Rigorous filtering processes were conducted to prioritize pathogenic somatic variations,and all identified SNVs and indels were further confirmed by Sanger sequencing.Results:One somatic SNV and two somatic indels were identified after rigorous selection processes.However,none was validated by Sanger sequencing.Conclusions:This study is not alone in the failure to identify pathogenic somatic variations in MZ twins,suggesting that exonic somatic variations are extremely rare.Further efforts are warranted to explore the potential genetic mechanism of SCZ.

  12. Crown-rump length discordance in the first trimester: a predictor of adverse outcome in twin pregnancies?

    DEFF Research Database (Denmark)

    Johansen, Mathias; Oldenburg, A.; Rosthøj, Susanne;

    2014-01-01

    OBJECTIVES: To evaluate the usefulness of first-trimester crown-rump length (CRL) discordance in predicting adverse outcome in twin pregnancies. METHODS: This retrospective study included a large cohort retrieved from local ultrasound databases at 14 obstetric departments in Denmark, comprising a...

  13. Levels of Adipokines in Amniotic Fluid and Cord Blood Collected from Dichorionic-Diamniotic Twins Discordant for Fetal Growth.

    Directory of Open Access Journals (Sweden)

    Seung Mi Lee

    Full Text Available To compare the concentrations of adipokines in amniotic fluid (AF and cord blood collected from discordant dichorionic-diamniotic (DCDA twin fetuses.The study population included DCDA twins discordant for fetal growth (birth weight difference >10% who either underwent mid-trimester amniocentesis for routine clinical indication (Cohort 1 or whose amniotic fluid was collected at the time of delivery (Cohort 2. In both cohorts, cord blood was collected at delivery.A total of 92 twin pairs were enrolled (n = 49 in Cohort 1; n = 43 in Cohort 2. In Cohort 1, the concentrations of adiponectin (median, 68.5 ng/mL vs 61.4 ng/mL; p<0.05 and leptin (median, 13.9 ng/mL vs 11.2 ng/mL; p<0.1 in mid-trimester AF were significantly higher in smaller compared with larger twins. In Cohort 2, the concentration of serpin E1 (median, 246.0 ng/mL vs 182.8 ng/mL; p<0.01 in AF at delivery was significantly higher in smaller twins, but no difference was noted in adiponectin and leptin concentrations. Levels of adiponectin (median, 10425.5 ng/mL vs 11552.0 ng/mL; p<0.005 and leptin (median, 2.1 ng/mL vs 2.6 ng/mL; p<0.005 were significantly lower in the cord blood of smaller twins whereas cord blood concentrations of serpin E1 (median, 15.5 ng/mL vs 13.3 ng/mL; p<0.05 was higher in the smaller twins.In discordant DCDA twin pairs, concentrations of adiponectin, leptin, and serpin E1 in mid-trimester AF, AF at delivery, and cord blood at birth vary significantly but predictably between the smaller and larger twins.

  14. Levels of Adipokines in Amniotic Fluid and Cord Blood Collected from Dichorionic-Diamniotic Twins Discordant for Fetal Growth

    Science.gov (United States)

    Park, Joong Shin; Norwitz, Errol R.; Panyavatthanasinh, Sitthysack; Kim, Sun Min; Lee, JoonHo; Park, Chan-Wook; Kim, Byoung Jae; Jun, Jong Kwan

    2016-01-01

    Objective To compare the concentrations of adipokines in amniotic fluid (AF) and cord blood collected from discordant dichorionic-diamniotic (DCDA) twin fetuses. Study Design The study population included DCDA twins discordant for fetal growth (birth weight difference >10%) who either underwent mid-trimester amniocentesis for routine clinical indication (Cohort 1) or whose amniotic fluid was collected at the time of delivery (Cohort 2). In both cohorts, cord blood was collected at delivery. Results A total of 92 twin pairs were enrolled (n = 49 in Cohort 1; n = 43 in Cohort 2). In Cohort 1, the concentrations of adiponectin (median, 68.5 ng/mL vs 61.4 ng/mL; ptwins. In Cohort 2, the concentration of serpin E1 (median, 246.0 ng/mL vs 182.8 ng/mL; ptwins, but no difference was noted in adiponectin and leptin concentrations. Levels of adiponectin (median, 10425.5 ng/mL vs 11552.0 ng/mL; ptwins whereas cord blood concentrations of serpin E1 (median, 15.5 ng/mL vs 13.3 ng/mL; ptwins. Conclusion In discordant DCDA twin pairs, concentrations of adiponectin, leptin, and serpin E1 in mid-trimester AF, AF at delivery, and cord blood at birth vary significantly but predictably between the smaller and larger twins. PMID:27135745

  15. Brain Activation during Memory Encoding in Type 2 Diabetes Mellitus: A Discordant Twin Pair Study

    Science.gov (United States)

    Wood, Amanda G.; Chen, Jian; Moran, Christopher; Phan, Thanh; Beare, Richard; Cooper, Kimberley; Litras, Stacey; Srikanth, Velandai

    2016-01-01

    Type 2 diabetes mellitus increases the risk of dementia and neuronal dysfunction may occur years before perceptible cognitive decline. We aimed to study the impact of type 2 diabetes on brain activation during memory encoding in middle-aged people, controlling for age, sex, genes, and early-shared environment. Twenty-two twin pairs discordant for type 2 diabetes mellitus (mean age 60.9 years) without neurological disease were recruited from the Australian Twin Registry (ATR) and underwent functional magnetic resonance imaging (fMRI) during a memory encoding task, cognitive tests, and structural MRI. Type 2 diabetes was associated with significantly reduced activation in left hemisphere temporoparietal regions including angular gyrus, supramarginal gyrus, and middle temporal gyrus and significantly increased activation in bilateral posteriorly distributed regions. These findings were present in the absence of within-pair differences in standard cognitive test scores, brain volumes, or vascular lesion load. Differences in activation were more pronounced among monozygotic (MZ) pairs, with MZ individuals with diabetes also displaying greater frontal activation. These results provide evidence for preclinical memory-related neuronal dysfunction in type 2 diabetes. They support the search for modifiable later-life environmental factors or epigenetic mechanisms linking type 2 diabetes and cognitive decline.

  16. Brain Activation during Memory Encoding in Type 2 Diabetes Mellitus: A Discordant Twin Pair Study

    Directory of Open Access Journals (Sweden)

    Amanda G. Wood

    2016-01-01

    Full Text Available Type 2 diabetes mellitus increases the risk of dementia and neuronal dysfunction may occur years before perceptible cognitive decline. We aimed to study the impact of type 2 diabetes on brain activation during memory encoding in middle-aged people, controlling for age, sex, genes, and early-shared environment. Twenty-two twin pairs discordant for type 2 diabetes mellitus (mean age 60.9 years without neurological disease were recruited from the Australian Twin Registry (ATR and underwent functional magnetic resonance imaging (fMRI during a memory encoding task, cognitive tests, and structural MRI. Type 2 diabetes was associated with significantly reduced activation in left hemisphere temporoparietal regions including angular gyrus, supramarginal gyrus, and middle temporal gyrus and significantly increased activation in bilateral posteriorly distributed regions. These findings were present in the absence of within-pair differences in standard cognitive test scores, brain volumes, or vascular lesion load. Differences in activation were more pronounced among monozygotic (MZ pairs, with MZ individuals with diabetes also displaying greater frontal activation. These results provide evidence for preclinical memory-related neuronal dysfunction in type 2 diabetes. They support the search for modifiable later-life environmental factors or epigenetic mechanisms linking type 2 diabetes and cognitive decline.

  17. Discordant cerebral lateralisation for verbal fluency is not an artefact of attention: evidence from MzHd twins.

    Science.gov (United States)

    Gurd, Jennifer M; Cowell, Patricia E

    2015-01-01

    The current study investigated how the brain structure-function relationships between covert and overt verbal fluency in monozygotic handedness discordant (MzHd) twins relates to broader attentional measures. Evidence presented here shows that the structure-function correlation demonstrated between functional cerebral lateralisation and corpus callosum widths 22-39, contiguous with Broca's area and the middle frontal gyri (Gurd et al. in Brain Struct Funct 218:491-509, 2013), is not an artefact of attention. Twenty-five pairs of female MzHd twins performed a verbal switching task titrated for number of switches. The paradigm permits calculation of switch rates and costs. The switch rate and cost varied as a function of number of switches (1, 2, 3). There were no differences in any measure in relation to right-left handedness in twin pairs. This was supported by large and significant within-twin pair correlations. Atypical functional lateralisation of inferior and middle frontal lobes does not appear to be associated with better or worse performance on verbal task-switching. Discordant lateralisation for verbal fluency does not predict behavioural performance profiles in MzHd twins. This evidence is compatible with a view that attentional components of verbal fluency task performance may have significant heritable components. It does not indicate that neural correlates of frontal cerebral laterality for verbal fluency in MzHd twins are significantly accountable for by heritable components. PMID:24092462

  18. Increased SERT DNA methylation is associated with bullying victimization and blunted cortisol response to stress in childhood: a longitudinal study of discordant MZ twins

    OpenAIRE

    Isabelle Ouellet-Morin; Chloe Wong; Andrea Danese; Pariante, Carmine M.; Papadopoulos, Andrew S.; Jonathan Mill; Louise Arseneault

    2012-01-01

    Childhood adverse experiences are known to induce persistent changes in the hypothalamic–pituitary–adrenal (HPA) axis reactivity to stress. However, the mechanisms by which these experiences shape neuroendocrine response to stress remain unclear.We tested whether bullying victimization influenced SERT DNA methylation using a discordant monozygotic (MZ) twin design. A sub-sample of 28 MZ twin pairs discordant for bullying victimization, with data on cortisol and DNA methylation, ...

  19. Exercise electrocardiography and aortic Doppler velocimetry in asymptomatic identical twins discordant for type 1 (insulin dependent) diabetes.

    OpenAIRE

    Dubrey, S; Akhras, F; Song, G J; Hardman, T.; Travill, C.; Hynd, J.; Noble, M. I.; Lo, S S; Leslie, R D

    1994-01-01

    OBJECTIVE--To determine the influence of insulin dependent diabetes on the prevalence of myocardial ischaemia and on global left ventricular systolic performance. DESIGN--Stress treadmill electrocardiograms and simultaneous Doppler measurement of aortic maximum acceleration were obtained during exercise on symptom free subjects. The electrocardiograms were scored blindly according to the Minnesota code. PARTICIPANTS--39 identical twin pairs (22 male) discordant for insulin dependent diabetes ...

  20. Dermatoglyphics in relation to brain volumes in twins concordant and discordant for bipolar disorder.

    Science.gov (United States)

    Vonk, R; van der Schot, A C; van Baal, G C M; van Oel, C J; Nolen, W A; Kahn, R S

    2014-12-01

    Palmar and finger dermatoglyphics are formed between the 10th and the 17th weeks of gestation and their morphology can be influenced by genetic or environmental factors, interfering with normal intrauterine development. As both the skin and the brain develop from the same embryonal ectoderm, dermatoglyphic alterations may be informative for early abnormal neurodevelopmental processes in the brain. We investigated whether dermatoglyphic alterations are related to structural brain abnormalities in bipolar disorder and to what extent they are of a genetic and of an environmental origin. Dermatoglyphics and volumetric data from structural MRI were obtained in 53 twin pairs concordant or discordant for bipolar disorder and 51 healthy matched control twin pairs. Structural equation modeling was used. Bipolar disorder was significantly positively associated with palmar a-b ridge count (ABRC), indicating higher ABRC in bipolar patients (rph=.17 (CI .04-.30)). Common genes appear to be involved because the genetic correlation with ABRC was significant (rph-A=.21 (CI .05-.36). Irrespective of disease, ABRC showed a genetically mediated association with brain volume, indicated by a significant genetic correlation rph-A of respectively -.36 (CI -.52 to -.22) for total brain, -.34 (CI -.51 to -.16) total cortical volume, -.27 (CI -.43 to -.08) cortical gray matter and -.23 (CI -.41 to -.04) cortical white matter. In conclusion, a genetically determined abnormal development of the foetal ectoderm between the 10th and 15th week of gestation appears related to smaller brain volumes in (subjects at risk for) bipolar disorder. PMID:25451699

  1. Síndrome de Goldenhar: relato de um caso com discordância em gêmeas monozigóticas Monozygotic twins discordant for Goldenhar syndrome

    Directory of Open Access Journals (Sweden)

    Leonardo Lima Verona

    2006-02-01

    Full Text Available OBJETIVO: Relatar um par de gêmeas monozigóticas, no qual uma das crianças é afetada pela síndrome de Goldenhar, enquanto a outra é saudável. DESCRIÇÃO: Paciente do sexo feminino, filha de pais sadios, jovens e não consangüíneos. A propósita nasceu de parto cesáreo pré-termo com Capurro somático de 35 semanas e 2 dias, pesando 2.170 g, com 42,5 cm de comprimento, perímetro cefálico de 30 cm e Apgar 3/7. Ao nascimento, a criança evoluiu com desconforto respiratório grave, sendo transferida para unidade de tratamento intensivo neonatal. A outra gemelar nasceu com 3.200 g, 49 cm de comprimento, 34 cm de perímetro cefálico e Apgar 8/10. Foi transferida junto com a mãe para o alojamento conjunto da maternidade e recebeu alta com 2 dias de vida. A criança afetada apresentava hipoplasia facial esquerda, micrognatia importante, displasia de pavilhão auricular e apêndices pré-auriculares bilaterais e dermóide epibulbar à direita. Evoluiu com apnéia obstrutiva, em conseqüência da micrognatia, e necessitou de traqueostomia. As ultra-sonografias de crânio e abdome foram normais, a radiografia de coluna total mostrou hemivértebra em T9/T10, o ecocardiograma detectou tetralogia de Fallot, e o cariótipo realizado a partir de linfócitos de sangue periférico com bandeamento GTG foi 46,XX. A avaliação oftalmológica foi normal. O exame molecular provou tratar-se de gêmeas monozigóticas com 99,99% de probabilidade. COMENTÁRIO: A clínica e os exames complementares levaram ao diagnóstico de síndrome de Goldenhar. Existem relatos de gemelares afetados por essa condição com expressividade variável, o que corrobora a hipótese de que a etiologia não é puramente genética, mas resultado de um processo de disrupção vascular no período de morfogênese.OBJECTIVE: To report on a pair of monozygotic female twins discordant for Goldenhar syndrome. DESCRIPTION: The affected twin was a girl, who was delivered by caesarean

  2. Monozygotic twins are discordant for chronic periodontitis: clinical and bacteriological findings

    NARCIS (Netherlands)

    G.L. Torres de Heens; B.G. Loos; U. van der Velden

    2010-01-01

    Objectives: The aim of this study was to assess, in monozygotic (MZ) and dizygotic (DZ) twin pairs in whom the proband of the twin pair was suffering from moderate to severe chronic periodontitis, the contribution of genetics, periodontal pathogens and lifestyle factors towards the clinical phenotyp

  3. The Discordant MZ-Twin Method: One Step Closer to the Holy Grail of Causality

    Science.gov (United States)

    Vitaro, Frank; Brendgen, Mara; Arseneault, Louise

    2009-01-01

    Twin studies are well known for their value in quantifying the contribution of genes to population variation in behaviors and personality traits. Twin studies also provide a unique opportunity to untangle the contribution of environmental experiences to emotional and behavioral development. This is particularly true when examining monozygotic (MZ)…

  4. Genome-wide analysis of DNA methylation differences in muscle and fat from monozygotic twins discordant for type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Rasmus Ribel-Madsen

    Full Text Available BACKGROUND: Monozygotic twins discordant for type 2 diabetes constitute an ideal model to study environmental contributions to type 2 diabetic traits. We aimed to examine whether global DNA methylation differences exist in major glucose metabolic tissues from these twins. METHODOLOGY/PRINCIPAL FINDINGS: Skeletal muscle (n = 11 pairs and subcutaneous adipose tissue (n = 5 pairs biopsies were collected from 53-80 year-old monozygotic twin pairs discordant for type 2 diabetes. DNA methylation was measured by microarrays at 26,850 cytosine-guanine dinucleotide (CpG sites in the promoters of 14,279 genes. Bisulfite sequencing was applied to validate array data and to quantify methylation of intergenic repetitive DNA sequences. The overall intra-pair variation in DNA methylation was large in repetitive (LINE1, D4Z4 and NBL2 regions compared to gene promoters (standard deviation of intra-pair differences: 10% points vs. 4% points, P<0.001. Increased variation of LINE1 sequence methylation was associated with more phenotypic dissimilarity measured as body mass index (r = 0.77, P = 0.007 and 2-hour plasma glucose (r = 0.66, P = 0.03 whereas the variation in promoter methylation did not associate with phenotypic differences. Validated methylation changes were identified in the promoters of known type 2 diabetes-related genes, including PPARGC1A in muscle (13.9±6.2% vs. 9.0±4.5%, P = 0.03 and HNF4A in adipose tissue (75.2±3.8% vs. 70.5±3.7%, P<0.001 which had increased methylation in type 2 diabetic individuals. A hypothesis-free genome-wide exploration of differential methylation without correction for multiple testing identified 789 and 1,458 CpG sites in skeletal muscle and adipose tissue, respectively. These methylation changes only reached some percentage points, and few sites passed correction for multiple testing. CONCLUSIONS/SIGNIFICANCE: Our study suggests that likely acquired DNA methylation changes in skeletal muscle or adipose tissue gene

  5. Gray and white matter density changes in monozygotic and same-sex dizygotic twins discordant for schizophrenia using voxel-based morphometry

    DEFF Research Database (Denmark)

    Hulshoff Pol, HE; Schnack, HG; Mandl, RC;

    2006-01-01

    Global gray matter brain tissue volume decreases in schizophrenia have been associated to disease-related (possibly nongenetic) factors. Global white matter brain tissue volume decreases were related to genetic risk factors for the disease. However, which focal gray and white matter brain regions...... best reflect the genetic and environmental risk factors in the brains of patients with schizophrenia remains unresolved. 1.5-T MRI brain scans of 11 monozygotic and 11 same-sex dizygotic twin-pairs discordant for schizophrenia were compared to 11 monozygotic and 11 same-sex dizygotic healthy control...... gyrus in twin-pairs discordant for schizophrenia as compared to healthy twin-pairs. Focal changes in left medial (orbito)frontal and left sensory motor gyri may reflect the increased genetic risk to develop schizophrenia. Focal changes in the left anterior hemisphere may therefore be particularly...

  6. Behavioral versus genetic determination of lipoproteins and identical twins discordant for exercise

    OpenAIRE

    Williams, Paul T.; Blanche, Patricia J.; Krauss, Ronald M

    2004-01-01

    Background: Lipoprotein and weight differences between vigorously active and sedentary MZ twins are used to: 1) estimate the effects of training while controlling for genotype; 2) estimate genetic concordance in the presence of divergent lifestyles.

  7. Discordancia de peso al nacer: consecuencias y su perdurabilidad en el desarrollo psicológico del gemelo de menor peso intrapar (Intertwin birth weight discordance: its effects and their persistence in the psychological development of the lightest intrapair twin

    Directory of Open Access Journals (Sweden)

    Elena Escolano-Pérez

    2015-08-01

    Full Text Available More twins are being born with intrapair birth weight discordances. Discordance in birth weight is a risk factor that can affect the development of twins, especially that of the lightest twin. However, few studies have analysed the possible consequences of birth weight discordance on the lightest twin beyond possible neonatal obstetric problems. Thus,little is known about the consequences of birth weight discordance on the psychological development of such babies.This article reviews the literature and summarizes the effects of birth weight discordance on the psychological development of the lightest intrapair twins compared with their heavier twin siblings and the persistence of these effects during their lifetime. The literature shows that the lightest intrapair twins obtain lower scores than their siblings in cognitive, verbal, and psychomotor skills. They are also more likely to have traits associated with the development of hyperactivity. These differences persist from childhood to youth. There is no information about adulthood. In conclusion, birth weight discordance has marked effects on the psychological development of intrapair lower weight twins, both in relation to the affected dimensions and the persistence of these effects over time. Further research is needed on designing early preventative interventions that would optimize the development of these children. This proposal is of relevance, given that the optimal development of all children is the basis of a society in continuous progress.

  8. Absence of Substantial Copy Number Differences in a Pair of Monozygotic Twins Discordant for Features of Autism Spectrum Disorder

    Directory of Open Access Journals (Sweden)

    Marina Laplana

    2014-01-01

    Full Text Available Autism spectrum disorder (ASD is a highly heritable disease (~0.9 with a complex genetic etiology. It is initially characterized by altered cognitive ability which commonly includes impaired language and communication skills as well as fundamental deficits in social interaction. Despite the large amount of studies described so far, the high clinical diversity affecting the autism phenotype remains poorly explained. Recent studies suggest that rare genomic variations, in particular copy number variation (CNV, may account for a significant proportion of the genetic basis of ASD. The use of disease-discordant monozygotic twins represents a powerful strategy to identify de novo and inherited CNV in the disorder. Here we present the results of a comparative genome hybridization (CGH analysis with a pair of monozygotic twins affected of ASD with significant differences in their clinical manifestations that specially affect speech language impairment and communication skills. Array CGH was performed in three different tissues: blood, saliva, and hair follicle, in an attempt to identify germinal and somatic CNV regions that may explain these differences. Our results argue against a role of large CNV rearrangements as a molecular etiology of the observed differences. This forwards future research to explore de novo point mutation and epigenomic alterations as potential explanations of the observed clinical differences.

  9. Low birth weight is associated with NIDDM in discordant monozygotic and dizygotic twin pairs

    DEFF Research Database (Denmark)

    Poulsen, P; Vaag, Allan; Kyvik, K O;

    1997-01-01

    Previous studies have demonstrated an association between low weight at birth and risk of later development of non-insulin-dependent diabetes mellitus (NIDDM). It is not known whether this association is due to an impact of intrauterine malnutrition per se, or whether it is due to a coincidence......) compared with twins with normal glucose tolerance (n = 112: 2800 +/- 51 g; p = 0.01 and p = 0.03, respectively). Furthermore, the twins with the lowest birth weights among the two co-twins had the highest plasma glucose concentrations 120 min after the 75-g oral glucose load (n = 86 pairs: 9.6 +/- 0.6 vs 8.......0 +/- 0.4 mmol/l, p = 0.03). In conclusion, the association between low birth weight and NIDDM in twins is at least partly independent of genotype and may be due to intrauterine malnutrition. IGT was also associated with low birth weight in twins. However, the possibility cannot be excluded that the...

  10. A study of genetic and environmental contributions to structural brain changes over time in twins concordant and discordant for bipolar disorder.

    Science.gov (United States)

    Bootsman, F; Brouwer, R M; Schnack, H G; Kemner, S M; Hillegers, M H J; Sarkisyan, G; van der Schot, A C; Vonk, R; Hulshoff Pol, H E; Nolen, W A; Kahn, R S; van Haren, N E M

    2016-08-01

    This is the first longitudinal twin study examining genetic and environmental contributions to the association between liability to bipolar disorder (BD) and changes over time in global brain volumes, and global and regional measures of cortical surface area, cortical thickness and cortical volume. A total of 50 twins from pairs discordant or concordant for BD (monozygotic: 8 discordant and 3 concordant pairs, and 1 patient and 3 co-twins from incomplete pairs; dizygotic: 6 discordant and 2 concordant pairs, and 1 patient and 7 co-twins from incomplete pairs) underwent magnetic resonance imaging twice. In addition, 57 twins from healthy twin pairs (15 monozygotic and 10 dizygotic pairs, and 4 monozygotic and 3 dizygotic subjects from incomplete pairs) were also scanned twice. Mean follow-up duration for all twins was 7.5 years (standard deviation: 1.5 years). Data were analyzed using structural equation modeling software OpenMx. The liability to BD was not associated with global or regional structural brain changes over time. Although we observed a subtle increase in cerebral white matter in BD patients, this effect disappeared after correction for multiple comparisons. Heritability of brain changes over time was generally low to moderate. Structural brain changes appear to follow similar trajectories in BD patients and healthy controls. Existing brain abnormalities in BD do not appear to progressively change over time, but this requires additional confirmation. Further study with large cohorts is recommended to assess genetic and environmental influences on structural brain abnormalities in BD, while taking into account the influence of lithium on the brain. PMID:27218817

  11. Case report. Johanson-Blizzard syndrome: a report of gender-discordant twins with a novel UBR1 mutation.

    Science.gov (United States)

    Quaio, C R; Koda, Y K; Bertola, D R; Sukalo, M; Zenker, M; Kim, C A

    2014-01-01

    Johanson-Blizzard syndrome (JBS) is a rare autosomal recessive disorder resulting from loss-of-function mutations in the UBR1 gene. JBS can be easily recognized by its unique clinical presentation (including exocrine pancreatic insufficiency, hypoplasia/aplasia of the alae nasi, congenital scalp defects, sensorineural hearing loss, growth retardation, psychomotor retardation, and anal and genitourinary anomalies). The objective of this study is to report on the first familial case of gender-discordant twins presenting JBS and a novel mutation in the UBR1 gene. We also review literature describing molecularly confirmed cases of JBS. The female twin developed refractory severe diarrhea after the second month of life and died at the age of 3 months. The male twin also developed diarrhea and failure to thrive after the 3 month of life but improved when nutrition support and pancreatic enzyme replacement was started, and he has survived into adolescence. Both patients presented typical clinical features of JBS. A homozygous nonsense mutation (c.3682C>T; p.Q1228X) in UBR1 was confirmed. Severe presentation of JBS usually involves deleterious (nonsense, frameshift, or splice-site) mutations in the UBR1 gene that are thought to completely abolish the expression of a functional protein product, as in this familial case; however, milder presentation of JBS has occasionally been observed with missense mutations in at least 1 of the 2 copies of UBR1, in which there may be residual activity of the product of this gene. Early diagnosis and adequate treatment are crucial for a favorable outcome. PMID:25036160

  12. Whole blood BDNF levels in healthy twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Trajkovska, Viktorija; Vinberg, Maj; Aznar, Susana;

    2008-01-01

    BACKGROUND: Depression has been associated with decreased blood BDNF concentrations; but it is unclear if low blood BDNF levels are a state or a trait marker of depression. METHODS: We investigated blood BDNF concentrations in a twin population including both subjects highly predisposed and prote...

  13. Subclinical psychopathology and socio-economic status in unaffected twins discordant for affective disorder

    DEFF Research Database (Denmark)

    Vinberg Christensen, Maj; Kyvik, Kirsten Ohm; Vedel Kessing, Lars

    2006-01-01

    liability to affective disorder seem to present lower socio-economic status, higher rates of subclinical affective symptoms and more often experience a minor psychiatric diagnosis than twins with no familial history of affective disorder. It is not possible from the present cross-sectional data to determine...... the causality of these findings, thus genetic liability to affective disorder, socio-economic status and minor psychopathology seem to have a complex interrelation....

  14. Telomere Length, Telomerase Activity, and Replicative Potential in HIV Infection: Analysis of CD4+ and CD8+T Cells from HIV-discordant Monozygotic Twins

    OpenAIRE

    Palmer, Larry D.; Weng, Nan-ping; Levine, Bruce L.; June, Carl H; Lane, H. Clifford; Hodes, Richard J.

    1997-01-01

    To address the possible role of replicative senescence in human immunodeficiency virus (HIV) infection, telomere length, telomerase activity, and in vitro replicative capacity were assessed in peripheral blood T cells from HIV+ and HIV− donors. Genetic and age-specific effects on these parameters were controlled by studying HIV-discordant pairs of monozygotic twins. Telomere terminal restriction fragment (TRF) lengths from CD4+ T cells of HIV+ donors were significantly greater than those from...

  15. Association of COMT genotypes with S-COMT promoter methylation in growth-discordant monozygotic twins and healthy adults

    Directory of Open Access Journals (Sweden)

    Schreiner Felix

    2011-09-01

    Full Text Available Abstract Background Catechol-O-Methyltransferase (COMT plays a key role in dopamine and estrogen metabolism. Recently, COMT haplotypes rather than the single polymorphism Val158Met have been reported to underlie differences in protein expression by modulating mRNA secondary structure. So far, studies investigating the epigenetic variability of the S-COMT (soluble COMT promoter region mainly focused on phenotypical aspects, and results have been controversial. Methods We assessed S-COMT promoter methylation in saliva and blood derived DNA with regard to early pre- and postnatal growth as well as to genotype for polymorphisms rs6269, rs4633, and rs4680 (Val158Met in 20 monozygotic twin pairs (mean age 4 years, who were discordant for intrauterine development due to severe feto-fetal-transfusion syndrome. Methylation levels of two previously reported partially methylated cytosines were determined by the quantitative SIRPH (SNuPE- IP RP HPLC assay. Results Overall, we observed a high variability of S-COMT promoter methylation, which did not correlate with individual differences in the pre- or postnatal growth pattern. Within the twin pairs however we noted a distinct similarity that could be linked to underlying COMT genotypes. This association was subsequently confirmed in a cohort of 93 unrelated adult controls. Interestingly, 158Val-alleles were found at both ends of the epigenotypical range, which is in accordance with a recently proposed model of COMT haplotypes corresponding to a continuum of phenotypical variability. Conclusion The strong heritable component of S-COMT promoter methylation found in our study needs to be considered in future approaches that focus on interactions between COMT epigenotype and phenotype.

  16. Common immune-related exposures/conditions and risk of non-Hodgkin lymphoma: a case-control study of disease-discordant twin pairs.

    Science.gov (United States)

    Wang, Jun; Mack, Thomas M; Hamilton, Ann S; Hwang, Amie E; Nathwani, Bharat N; Masood, Kamil; Buchanan, Laura H; Bernstein, Leslie; Deapen, Dennis M; Martínez-Maza, Otoniel; Cozen, Wendy

    2015-09-01

    We evaluated the association between common immune system-altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%-97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors. PMID:26271116

  17. Discordant Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome in identical twins - a case report and implications for reproduction in MRKH women.

    Science.gov (United States)

    Milsom, Stella Ruth; Ogilvie, Cara Megan; Jefferies, Craig; Cree, Lynsey

    2015-01-01

    Infertility has previously been considered as an inevitable consequence of Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome. With modern assisted reproductive technology (ART) techniques becoming increasingly accessible, MRKH women have the opportunity for their own genetic offspring. The availability of such technology, however, increases the importance of understanding the aetiology of this complex condition. The literature debating the relevance of genetic versus post-zygotic events in the aetiology of MRKH syndrome is reviewed in the context of this report of monozygotic twins discordant for MRKH syndrome. PMID:26291808

  18. Energy expenditure, body composition and insulin response to glucose in male twins discordant for the Trp64Arg polymorphism of the beta3-adrenergic receptor gene

    DEFF Research Database (Denmark)

    Højlund, K; Christiansen, C; Bjørnsbo, K S;

    2006-01-01

    secretion could play a role. METHODS: In 10 male twin pairs discordant for the Trp64Arg polymorphism, we examined insulin response to glucose by an oral glucose tolerance test (OGTT), a frequently sampled intravenous glucose tolerance test (FSIGT), body composition by the bioimpedance method, dual-energy X......AIM: The tryptophan to arginine change in position 64 (Trp64Arg) polymorphism of the beta3-adrenergic receptor (beta3AR) gene has been associated with an increased prevalence of obesity, insulin resistance and type 2 diabetes. In this, decreased rates of energy expenditure and impaired insulin......-ray absorptiometry scanning and energy expenditure by indirect and direct calorimetry. RESULTS: Twins heterozygous for the Trp64Arg polymorphism showed significantly lower fat mass independent of the method used, and significantly lower fasting insulin and glucose concentrations compared with their homozygous wild...

  19. Monokoryonik diamniotik ikiz esi major fetal anomali gebeliklerde bipolar kord koagulasyonu --- Bipolar cord coagulation in monochorionic twins discordant for major fetal anomalies

    Directory of Open Access Journals (Sweden)

    Kemal Gungorduk

    2008-04-01

    tartisilarak ailelere prenatal tedavi secenegi olarak sunulmalidirOBJECTIVE: We aimed to evaluate perinatal outcome of selective fetocide in monochorionic diamniotic (MCDA twins discordant for major fetal anomalies. MATERIALS-METHOD: Stduy group included nine cases of MCDA twin (triplet pregnancies discordant for major fetal anomalies; anencephaly (n: 2, inencephaly (n: 1, lumbar meningomyolocele (n: 1, hidrops fetalis (n: 1, acardiac twin (n: 2, twin-to-twin transfusion syndrome (stage III, n: 1 and monochorionic triamniotic triplet discordant for anencephaly (n: 1. For bipolar coagulation of the umbilical cord, we used 3.5 mm laparoscopic trocar and 3.0 mm bipolar forcep. The procedures were performed under the guidance of transabdominal ultrasonography. RESULTS: The mean gestational age of the cases at intervention and at delivery were 20 weeks (R: 16-24 and 34 weeks (R: 22-38, respectively. The procedure of bipolar coagulation was carried out in mean 20 min (R: 15-40 min. without maternal complication. One case was aborted at 20 weeks of gestation because of preterm premature rupture of membrane after the procedure. Another case was delivered before 32 weeks, at 28+4 week of gestation, and died at postnatal six month age unrelated to intervention. The other seven cases were delivered after 32 gestational weeks. In eight cases, the procedure were performed without fetal complication. Perinatal outcome as live birth was 88.8% (N: 8/9. Postnatal ages of surviving seven babies were between 8-40 months, and they have been growing up as healthy. CONCLUSIONS: Ultrasonographic guided bipolar cord coagulation as a selective fetocide can be succesfully performed to increase the survival rate or prevent morbidity of healthy co-twin in the cases of MCDA (tripelts discordant major fetal anomalies candidate for selective termination, and should be offered as a choice of prenatal therapy after the parents were informed for intervention or follow up.

  20. Effects of type II collagen epitope carbamylation and citrullination in human leucocyte antigen (HLA)-DR4(+) monozygotic twins discordant for rheumatoid arthritis.

    Science.gov (United States)

    De Santis, M; Ceribelli, A; Cavaciocchi, F; Generali, E; Massarotti, M; Isailovic, N; Crotti, C; Scherer, H U; Montecucco, C; Selmi, C

    2016-09-01

    The aim of this study is to investigate the effect of the native, citrullinated or carbamylated type II human collagen T cell- and B cell-epitopes on the adaptive immune response in rheumatoid arthritis (RA). Peripheral blood T and B cells obtained from a human leucocyte D4-related (antigen DR4(-) HLA-DR4)(+) woman with early RA, her healthy monozygotic twin and an unrelated HLA-DR3(+) woman with early RA were analysed for activation (CD154/CD69), apoptosis (annexin/7-aminoactinomycin), cytokine production [interferon (IFN)γ/interleukin (IL)-17/IL-4/IL-10/IL-6] and functional phenotype (CD45Ra/CCR7) after stimulation with the collagen native T cell epitope (T261-273), the K264 carbamylated T cell epitope (carT261-273), the native B cell epitope (B359-369) or the R360 citrullinated B cell epitope (citB359-369), and the combinations of these. The T cell memory compartment was activated by T cell epitopes in both discordant DR4(+) twins, but not in the DR3(+) RA. The collagen-specific activation of CD4(+) T cells was induced with both the native and carbamylated T cell epitopes only in the RA twin. Both T cell epitopes also induced IL-17 production in the RA twin, but a greater IL-4 and IL-10 response in the healthy twin. The citrullinated B cell epitope, particularly when combined with the carbamylated T cell epitope, induced B cell activation and an increased IL-6/IL-10 ratio in the RA twin compared to a greater IL-10 production in the healthy twin. Our data suggest that circulating collagen-specific T and B cells are found in HLA-DR4(+) subjects, but only RA activated cells express co-stimulatory molecules and produce proinflammatory cytokines. Carbamylation and citrullination further modulate the activation and cytokine polarization of T and B cells. PMID:27314557

  1. Mixed-Handedness in Identical Twins Discordant for Combat Exposure in Vietnam: Relationship to Posttraumatic Stress Disorder.

    Science.gov (United States)

    Goetz, Jared M; Pitman, Seth R; Tanev, Kaloyan S; Pitman, Roger K; Chemtob, Claude M

    2016-01-01

    This study evaluated the degree of mixed-handedness in predominantly right-handed Vietnam combat veteran twins and their identical, combat-unexposed cotwins. The "high-risk" cotwins of combat veterans with combat-related posttraumatic stress disorder (PTSD) had more mixed-handedness (i.e., less right-handedness) than the "low-risk" cotwins of combat veterans without PTSD. Self-reported combat exposure in combat-exposed twins was a mediator of the association between handedness in their unexposed cotwins and PTSD in the twins themselves. We conclude that mixed-handedness is a familial risk factor for combat-related PTSD. This risk may be mediated in part by a proclivity for mixed-handed soldiers and Marines to experience heavier combat. PMID:26404173

  2. Differential methylation of the X-chromosome is a possible source of discordance for bipolar disorder female monozygotic twins

    NARCIS (Netherlands)

    Rosa, Araceli; Picchioni, Marco M.; Kalidindi, Sridevi; Loat, Caroline S.; Knight, Joanne; Toulopoulou, Timothea; Vonk, Ronald; van der Schot, Astrid C.; Nolen, Willem; Kahn, Rene S.; McGuffin, Peter; Murray, Robin M.; Craig, Ian W.

    2008-01-01

    Monozygotic (MZ) twins may be subject to epigenetic modifications that could result in different patterns of gene expression. Several lines of evidence suggest that epigenetic factors may underlie mental disorders such as bipolar disorder (BD) and schizophrenia (SZ). One important epigenetic modific

  3. Whole blood BDNF levels in healthy twins discordant for affective disorder: association to life events and neuroticism

    DEFF Research Database (Denmark)

    Trajkovska, V.; Vinberg, M.; Aznar, S.;

    2008-01-01

    BACKGROUND: Depression has been associated with decreased blood BDNF concentrations; but it is unclear if low blood BDNF levels are a state or a trait marker of depression. METHODS: We investigated blood BDNF concentrations in a twin population including both subjects highly predisposed and prote...

  4. X-chromosome inactivation patterns in monozygotic twins and sib pairs discordant for nonsyndromic cleft lip and/or palate

    DEFF Research Database (Denmark)

    Kimani, Jane W; Shi, Min; Daack-Hirsch, Sandra;

    2007-01-01

    Nonsyndromic clefts of the lip and/or palate are common birth defects with a strong genetic component. Based on unequal gender ratios for clefting phenotypes, evidence for linkage to the X chromosome and the occurrence of several X-linked clefting syndromes, we investigated the role of skewed X...... XCI was defined as the deviation in inactivation pattern from a 50:50 ratio. Our analysis revealed no significant difference in the degree of skewing between twin pairs (P = 0.3). However, borderline significant differences were observed in the sister pairs (P = 0.02), with the cleft lip with cleft......, particularly cleft lip and palate....

  5. Gêmeas idênticas discordantes para a doença de Cushing: relato de caso Identical twins discordant for Cushing's disease: case report

    Directory of Open Access Journals (Sweden)

    MARCELO MAIA PINHEIRO

    1999-09-01

    Full Text Available A doença de Cushing é rara em crianças e sua ocorrência em gêmeos é ainda mais rara. O presente estudo relata a ocorrência de gêmeas idênticas discordantes quanto à doença de Cushing. Uma das gêmeas, desenvolveu síndrome de Cushing aos 10 anos de idade. Sua investigação demonstrou cortisol urinário elevado, ACTH sérico elevado e testes de supressão com dexametasona compatíveis com doença de Cushing. A RMN mostrou macroadenoma hipofisário que foi operado por via transesfenoidal. O estudo imuno-histoquímico confirmou a presença de células produtoras de ACTH. A paciente entrou em remissão clínica e laboratorial desde a cirurgia. Após o desaparecimento dos estigmas do Cushing, a paciente reiniciou ganho estatural, mas permanece menor que sua irmã gêmea. Esta última permanece saudável 4 anos após o início da doença de sua irmã. Este é o terceiro caso do gênero relatado na literatura. Estes achados sugerem que fatores não genéticos estão envolvidos na gênese da doença de Cushing.Cushing's disease is rare in children and its ocurrence in identical twins is extremely rare. This paper reports on identical twins discordant for Cushing's disease. One of them first presented with a cushingoid phenotype by the age of 10. Her evaluation showed an increased urinary free-cortisol and serum ACTH. Her pattern in the dexametazone supression tests was compatible with Cushing's disease. MRI disclosed a pituitary macroadenoma which was removed by the transesphenoidal approach. Immunohistochemical studies of the tumor showed the presence of ACTH-producing cells. The patient went into clinical and laboratorial remission after surgery. She re-started to grow after the disappearance of the Cushing's phenotype but she is still shorter than her healthy sister. The latter remains disease-free 4 years after her sister's diagnosis. This represents the third such case reported in the literature. Our findings suggest that acquired

  6. Socioeconomic position and twins' health

    DEFF Research Database (Denmark)

    Osler, Merete; McGue, Matt; Christensen, Kaare

    2007-01-01

    of middle-aged Danish twins was conducted in 1998-99. The study population included 1266 like-sex twin pairs [52.5% monozygotic (MZ) and 47.6% dizygotic (DZ)]. Data were obtained on childhood and adult social class and on height, BMI, grip strength, depression symptoms, self-rated health, cognitive function......, physical activity, smoking, alcohol and food intake. RESULTS: The expected associations between the individual twins' adult social class and health measures were observed. Among DZ male twins discordant on adult social class, the higher social class twin was on average significantly taller and had higher...... cognitive test scores. Among DZ female twins discordant on adult social class, the higher social class female twin was more physically active and had a higher cognitive test score. There were no significant health disparities or behavioural differences between the members of MZ twin pairs discordant...

  7. Fetal growth disorders in twin gestations.

    LENUS (Irish Health Repository)

    Breathnach, Fionnuala M

    2012-06-01

    Twin growth is frequently mismatched. This review serves to explore the pathophysiologic mechanisms that underlie growth aberrations in twin gestations, the prenatal recognition of abnormal twin growth, and the critical importance of stratifying management of abnormal twin growth by chorionicity. Although poor in utero growth of both twins may reflect maternal factors resulting in global uteroplacental dysfunction, discordant twin growth may be attributed to differences in genetic potential between co-twins, placental dysfunction confined to one placenta only, or one placental territory within a shared placenta. In addition, twin-twin transfusion syndrome represents a distinct entity of which discordant growth is a common feature. Discordant growth is recognized as an independent risk factor for adverse perinatal outcome. Intertwin birth weight disparity of 18% or more should be considered to represent a discordance threshold, which serves as an independent risk factor for adverse perinatal outcome. At this cutoff, perinatal morbidity is found to increase both for the larger and the smaller twin within a discordant pair. There remains uncertainty surrounding the sonographic parameters that are most predictive of discordance. Although heightening of fetal surveillance in the face of discordant twin growth follows the principles applied to singleton gestations complicated by fetal growth restriction, the timing of intervention is largely influenced by chorionicity.

  8. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  9. [Ultrasonography of twin pregnancies].

    Science.gov (United States)

    Grignon, A; Dubois, J

    2002-12-01

    Sonographers must be familiar with the diagnostic tools available to them for determining twin pregnancy type. During the first trimester, these tools include the number of chorionic sacs, the number of yolk sacs, and the presence of an inter-twin membrane. During the second trimester, sonographers must look for a difference in sex, the presence of two separate placentas, and a thick vs. thin membrane, or the absence of a membrane. Complications are frequent in twin pregnancies and may be maternal or fetal. Measuring cervical length is the only way for sonographers to predict pre-term labour. A cervical length oftwin pregnancy than in single pregnancy. The more frequent are: esophageal atresia, omphalocele and cardiac anomalies. Some fetal anomalies are peculiar to twin pregnancy: Siamese twins, digestive atresia, craniofacial deformation and club-foot. A significant growth asymmetry is defined as a CRL of 3 or more millimetres and a difference of 20% in weight. The poly-oligo sequence represents a severe level asymmetry of amniotic fluid in monodiamniotic twins where survival rate without sequelae is 13.6%. The twin-twin transfusion syndrome is an event occurring after the apparition of the poly-oligo sequence, which manifests by discordances in weight and hemodynamic changes leading to myocardial repercussion. Twin embolization syndrome follows the in utero death of a co-twin in a monochorionic twin pregnancy; ischemic events must be monitored in such cases. Cord entanglement is unpredictable and is specific to monochorionic monoamniotic twin pregnancies. Finally, an acardius is a parasitic twin that feeds on its co-twin, resulting in the viable twin's death in 50% of cases. PMID:12592152

  10. Twin births: an overview

    Directory of Open Access Journals (Sweden)

    Sanjivani Anil Wanjari

    2014-08-01

    Full Text Available Background: The aim of this study was to investigate the maternal, foetal and obstetric parameters surrounding twin pregnancies. An attempt was made to find out the perinatal mortality and morbidity rates of twin births and to determine the underlying factors responsible for the increase in these rates. Methods: A one year observational study was done at Daga hospital Nagpur, which is a referral maternity hospital receiving a large number of antenatal patients daily. Perinatal mortality and morbidity rates, gestational age at delivery, birth weight, route of delivery, and caesarean section rates were analysed. Results: The commonest presentation in our study vertex/vertex presentation (62%. A large percentage of twins in our study had a normal delivery. 37% women had caesarean section. In our study nearly 17% of the neonates had birth weights <1.5 kg. In 51 % women the first baby had more birth weight than the second twin. Among the 95 twin births (190 twins studied, we had one discordant twins and one conjoined twins. Conclusions: Twin pregnancies are high risk pregnancies with more obstetrical complications compared to singleton pregnancies. Twin pregnancies have higher perinatal mortality and morbidity rates especially before 34 weeks of gestation. Hence deliveries should be performed in referral centres with competent NICUs. [Int J Reprod Contracept Obstet Gynecol 2014; 3(4.000: 995-997

  11. Gaussian geometric discord

    CERN Document Server

    Adesso, Gerardo

    2011-01-01

    We extend the geometric measure of quantum discord, introduced and computed for two-qubit states in [B. Dakic, C. Brukner, and V. Vedral, Phys. Rev. Lett. 105, 190502 (2010)], to quantify non-classical correlations in composite Gaussian states of continuous variable systems. We lay the formalism for the evaluation of a Gaussian geometric discord in two-mode Gaussian states, and present explicit formulas for the class of two-mode squeezed thermal states. In such a case, under physical constraints of bounded mean energy, geometric discord is shown to admit upper and lower bounds for a fixed value of the conventional (entropic) quantum discord. We finally discuss alternative geometric approaches to quantify Gaussian quadrature correlations.

  12. Danish cohort of monozygotic inflammatory bowel disease twins

    DEFF Research Database (Denmark)

    Moller, Frederik Trier; Knudsen, Lina; Harbord, Marcus;

    2016-01-01

    AIM: To describe the establishment of a Danish inflammatory bowel diseases (IBD) twin cohort with focus on concordance of treatment and inflammatory markers. METHODS: We identified MZ twins, likely to be discordant or concordant for IBD, by merging information from the Danish Twin Register and the......, the IBD diagnosis could be confirmed in 54 pairs. The cohort included 10 concordant pairs, whereof some were discordant for either treatment or surgery. The 10 concordant pairs, where both pairs suffered from IBD, included eight CD/CD pairs, one UC/UC pair and one UC/IBDU pair. The discordant pairs...... comprised 31 UC, 5 IBDU (IBD unclassified), and 8 CD discordant pairs. In the co-twins not affected by IBD, calprotectin was above 100 μg/g in 2 participants, and above 50 μg/g in a further 5 participants. CONCLUSION: The presented IBD twin cohorts are an excellent resource for bioinformatics studies with...

  13. Discord of response

    International Nuclear Information System (INIS)

    The presence of quantum correlations in a quantum state is related to the state's response to local unitary perturbations. Such a response is quantified by the distance between the unperturbed and perturbed states, minimized with respect to suitably identified sets of local unitary operations. In order to be a bona fide measure of quantum correlations, the distance function must be chosen among those that are contractive under completely positive and trace preserving (CPTP) maps. The most relevant instances of such physically well-behaved metrics include the trace, the Bures, and the Hellinger distance. To each of these metrics one can associate the corresponding discord of response, namely the trace, or Hellinger, or Bures minimum distance from the set of unitarily perturbed states. All these three discords of response satisfy the basic axioms for a proper measure of quantum correlations. In the present work we focus in particular on the Bures distance, which enjoys the unique property of being both Riemannian and contractive under CPTP maps, and admits important operational interpretations in terms of state distinguishability. We compute analytically the Bures discord of response for two-qubit states with maximally mixed marginals and we compare it with the corresponding Bures geometric discord, namely the geometric measure of quantum correlations defined as the Bures distance from the set of classical-quantum states. Finally, we investigate and identify the maximally quantum correlated two-qubit states according to the Bures discord of response. These states exhibit a remarkable nonlinear dependence on the global state purity. (paper)

  14. Returns to Education: What Do Twin Studies Control?

    OpenAIRE

    Stanek, Kevin C.; IACONO, WILLIAM G.; McGue, Matt

    2011-01-01

    The current paper examines the assumptions of the MZ co-twin control method that has been applied in attempts to gain more accurate estimates of the returns to education by naturally “controlling” for individual differences on which MZ twins are matched. The current study examined 1738 MZ and 926 DZ twins from Minnesota, including 133 pairs of MZ and 101 pairs of DZ twins discordant for university attendance. They were assessed prospectively on personality, intelligence, GPA, and academic mot...

  15. Twin methodology in epigenetic studies

    DEFF Research Database (Denmark)

    Tan, Qihua; Christiansen, Lene; von Bornemann Hjelmborg, Jacob;

    2015-01-01

    of diseases to molecular phenotypes in functional genomics especially in epigenetics, a thriving field of research that concerns the environmental regulation of gene expression through DNA methylation, histone modification, microRNA and long non-coding RNA expression, etc. The application of the twin method...... to molecular phenotypes offers new opportunities to study the genetic (nature) and environmental (nurture) contributions to epigenetic regulation of gene activity during developmental, ageing and disease processes. Besides the classical twin model, the case co-twin design using identical twins discordant...... for a trait or disease is becoming a popular and powerful design for epigenome-wide association study in linking environmental exposure to differential epigenetic regulation and to disease status while controlling for individual genetic make-up. It can be expected that novel uses of twin methods in epigenetic...

  16. Monozygotic twin pairs discordant for Hashimoto's thyroiditis share a high proportion of thyroid peroxidase autoantibodies to the immunodominant region A. Further evidence for genetic transmission of epitopic “fingerprints”

    DEFF Research Database (Denmark)

    Brix, Thomas Heiberg; Hegedüs, Laszlo; Gardas, Andrzej; Banga, J Paul; Nielsen, Claus H

    2010-01-01

    Thyroid peroxidase antibodies (TPOAbs) in patients with Hashimoto's thyroiditis (HT) predominantly react with two immunodominant regions (IDR-A, IDR-B). Theoretically, as shown for the level of TPOAbs, the autoantibody epitopic recognition of the IDRs could be under genetic control. To examine this......, we compared the distribution of TPOAb epitopic fingerprints between healthy monozygotic (MZ) co-twins and siblings to patients with clinically overt HT with a control group of euthyroid subjects, matched for sex and age, but without autoimmune thyroid disease (AITD) among their first-degree relatives...

  17. Operational interpretations of quantum discord

    International Nuclear Information System (INIS)

    Quantum discord quantifies nonclassical correlations beyond the standard classification of quantum states into entangled and unentangled. Although it has received considerable attention, it still lacks any precise interpretation in terms of some protocol in which quantum features are relevant. Here we give quantum discord its first information-theoretic operational meaning in terms of entanglement consumption in an extended quantum-state-merging protocol. We further relate the asymmetry of quantum discord with the performance imbalance in quantum state merging and dense coding.

  18. There Is a World outside of Experimental Designs: Using Twins to Investigate Causation

    Science.gov (United States)

    Hart, Sara A.; Taylor, Jeanette; Schatschneider, Christopher

    2013-01-01

    This study introduces a co-twin control method commonly used in the medical literature but not often within educational research. This method allows for a comparison of twins discordant for an "exposure," approximating alternative outcomes in the counterfactual model. Example analyses use data drawn from the Florida Twin Project on Reading to…

  19. Quantum discord with weak measurements

    International Nuclear Information System (INIS)

    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the “super quantum discord”, is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength

  20. Purified discord and multipartite entanglement

    International Nuclear Information System (INIS)

    We study bipartite quantum discord as a manifestation of a multipartite entanglement structure in the tripartite purified system. In particular, we find that bipartite quantum discord requires the presence of both bipartite and tripartite entanglement in the purification. This allows one to understand the asymmetry of quantum discord, D(A,B)≠D(B,A) in terms of entanglement monogamy. As instructive special cases, we study discord for qubits and Gaussian states in detail. As a result of this we shed new light on a counterintuitive property of Gaussian states: the presence of classical correlations necessarily requires the presence of quantum correlations. Finally, our results also shed new light on a protocol for remote activation of entanglement by a third party. -- Highlights: •Bipartite quantum discord as a manifestation of multipartite entanglement. •Relevance of quantum discord as a utilizable resource for quantum info. tasks. •Quantum discord manifests itself in entanglement in the purified state. •Relation between asymmetry of discord and entanglement monogamy. •Protocol for remote activation of entanglement by a third party

  1. Quantum discord with weak measurements

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Uttam, E-mail: uttamsingh@hri.res.in; Pati, Arun Kumar, E-mail: akpati@hri.res.in

    2014-04-15

    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the “super quantum discord”, is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength.

  2. Twin-twin transfusion syndrome - diagnosis and prognosis

    Directory of Open Access Journals (Sweden)

    Hajrić-Egić Amira

    2003-01-01

    Full Text Available Twin-twin transfusion syndrome is a serious complication of monozygotic, monochorionic, diamniotic twins resulting from transplacental vascular communications. In this syndrome blood is thought to be shunted from one twin - donor,who develops anaemia,growth retardation and oligoamnios, to the other twin - recipient,who becomes plethoric,macrosomic and develops polyhydroamnios. The incidence of twin-twin transfusion syndrome ranges from 5-15% of all twin pregnancies. If this condition develops in the second trimester, it is usually associated with spontaneous abortion and death of one or both fetuses before viability. Developing the syndrome in the third trimester has better perinatal outcome. Mortality rates ranging from 56%-100%, depending on gestational age and severity of the syndrome. The ultrasound criterias for diagnosis, in this study,were the presence of twins of the same sex with discordant growth, with oligohydroamnios in one twin sac and polyhydroamnios in the other one, one placenta and thin membrane between twins. The present study shows clinical course of 14 cases and value of Doppler ultrasound to analyze the usefulness of umbilical artery blood flow velocimetry for predicting the risk of twin-twin transfusion syndrome. 14 twin pregnancies with twin-twin transfusion syndrome were diagnosed during the last four years period and prospectivelly followed. 9 cases were diagnosed before the completion od 28 weeks of gestation.The mean gestational age was 21,6_+4,2 weeks at diagnosis and 23,2+_3,6 weeks at delivery. 5 cases were diagnosed after 28 weeks of gestation. The mean gestational age in this group was 29,6+_2,1 weeks at diagnosis and 33+_3,3 weeks at delivery. The survival rate in this study was 29%(8/28.9 cases ended in spontaneous abortion between 18th and 27th weeks of pregnancy (table 1 and 5 in premature labor (table 2.There were 7 intrauterine death (5 at admission and 2 few days after admission and 13 neonatal deaths

  3. Marital Conflict and Conduct Problems in Children of Twins

    OpenAIRE

    Harden, K. Paige; Turkheimer, Eric; Emery, Robert E.; D’Onofrio, Brian M; Slutske, Wendy S.; Andrew C Heath; Martin, Nicholas G.

    2007-01-01

    The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14–39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine whether genetic or environmental selection processes underlie the observed association between marital conflict and conduct problems. Results indicate tha...

  4. Doppler velocimetry for predicting fetal death in a twin pregnancy.

    OpenAIRE

    Soikkeli, Pia; Dubiel, Mariusz; Gudmundsson, Saemundur

    2002-01-01

    Diagnosis of discordant twins is easily accomplished with modern ultrasound equipment, though diagnosing twin-to-twin transfusion syndrome (TTS) at an early stage might be a problem. The possibility of excluding TTS by Doppler ultrasound is demonstrated in a case with early severe growth restriction of one fetus. Characteristic blood velocity changes in a dying fetus are also illustrated. The Doppler technique has become an accepted method in obstetrics for antenatal surveillance, perm...

  5. Monoamniotic Twins with One Fetal Anencephaly and Cord Entanglement Diagnosed with Three Dimensional Ultrasound at 14 Weeks of Gestation

    OpenAIRE

    Jo, Yun Sung; Son, Hyun Joo; Jang, Dong Gyu; Kim, Narinay; Lee, Guisera

    2011-01-01

    A 29-year-old pregnant woman with parity 0-0-0-0 was diagnosed with monoamniotic twin pregnancy discordant for anencephaly at 14 weeks gestation. Umbilical cord entanglement, which is an important cause of fetal death in monoamniotic twins, was confirmed by three-dimensional ultrasound. Cesarean section was performed at 34 weeks of gestation, and the normal newborn infant was discharged without any complications. We report a case of monoamniotic twin pregnancy discordant for anencephaly and d...

  6. Quantum Games and Quantum Discord

    CERN Document Server

    Nawaz, Ahmad

    2010-01-01

    We quantize prisoners dilemma and chicken game by our generalized quantization scheme to explore the role of quantum discord in quantum games. In order to establish this connection we use Werner-like state as an initial state of the game. In this quantization scheme measurement can be performed in entangled as well as in product basis. For the measurement in entangled basis the dilemma in both the games can be resolved by separable states with non-zero quantum discord. Similarly for product basis measurement the payoffs are quantum mechanical only for nonzero values of quantum discord.

  7. Operational interpretations of quantum discord

    CERN Document Server

    Cavalcanti, D; Boixo, S; Modi, K; Piani, M; Winter, A

    2010-01-01

    Quantum discord is a quantifier of non-classical correlations that goes beyond the standard classification of quantum states into entangled and unentangled ones. Although it has received considerable attention, it still lacks any precise interpretation in terms of some protocol in which quantum features are relevant. Here we give quantum discord its first operational meaning in terms on consumption of entanglement in an extended quantum state merging protocol. We go on to show that the asymmetry of quantum discord is related to the performance imbalance in quantum state merging and dense coding.

  8. Causal direction between respiratory syncytial virus bronchiolitis and asthma studied in monozygotic twins

    DEFF Research Database (Denmark)

    Poorisrisak, Porntiva; Halkjaer, Liselotte Brydensholt; Thomsen, Simon Francis;

    2010-01-01

    Respiratory syncytial virus (RSV) bronchiolitis has been associated with later development of asthma, wheezing, abnormal pulmonary function, and sensitization. Our aim was to determine the differential effect within monozygotic (MZ) twin pairs discordant for severe RSV bronchiolitis in infancy on...

  9. Similarities in drinking behavior of twin's friends: moderation of heritability of alcohol use

    OpenAIRE

    Poelen, E.A.P.; Engels, R. C. M. E.; Scholte, R.H.J.; Boomsma, D I; Willemsen, G.

    2009-01-01

    Previous research has indicated that friends' drinking may influence alcohol use in adolescents and young adults. We explored whether similarities in the drinking behavior of friends of twins influence the genetic architecture of alcohol use in adolescence and young adulthood. Survey data from The Netherlands Twin Register were available for 1,526 twin pairs aged 16-25 years. We categorized the twin pairs as concordant (both report similar alcohol use in their friends) or discordant for the a...

  10. Cerebellar dermoid tumor and occipital meningocele in a monozygotic twin : clues to the embryogenesis of craniospinal dysraphism

    NARCIS (Netherlands)

    Groen, R J; van Ouwerkerk, W J

    1995-01-01

    A case of monochorionic/monoamnionic twin with discordant occipital developmental malformations is presented. One female twin appeared to have an occipital meningocele with cerebellar aplasia and died immediately after birth. The other twin presented with signs and symptoms of raised intracranial pr

  11. Conjoined twins in Hungary, 1970-1986.

    Science.gov (United States)

    Métneki, J; Czeizel, A

    1989-01-01

    The total prevalence of conjoined twins (birth + prenatally diagnosed) was 1:68,000 in the study of 1970-1986. Symmetrical cases (the so-called siamese twins) have an obvious predominance (92.3%). Associated major malformations occurred in 80% of conjoined twins and more than 1/5 were discordant. The surviving time of liveborn conjoined twin sets was not more than two days except in two surgically successfully separated pairs. The family study did not indicate a higher recurrence risk. The case group was compared to two control groups and it appeared that the periconceptional use of oral contraception and ovulation induction were mentioned more frequently in pregnancies resulting in conjoined twins. PMID:2631499

  12. Twin births

    DEFF Research Database (Denmark)

    Hoffmann, Elise; Oldenburg, Anna; Rode, Line; Tabor, Ann; Rasmussen, Steen; Skibsted, Lillian

    2012-01-01

    To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery.......To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery....

  13. Twin RSA

    OpenAIRE

    Lenstra, Arjen K.; Weger, de, B.M.M.; Benjamin, M M

    2005-01-01

    We introduce Twin RSA, pairs of RSA moduli (n, n+ 2), and formulate several questions related to it. Our main questions are: is Twin RSA secure, and what is it good for? © Springer-Verlag Berlin Heidelberg 2005.

  14. [Adult twins].

    Science.gov (United States)

    Charlemaine, Christiane

    2006-12-31

    This paper explores the deep roots of closeness that twins share in their youngest age and their effect on their destiny at the adult age. Psychologists believe the bond between twins begins in utero and develops throughout the twins' lives. The four patterns of twinship described show that the twin bond is determined by the quality of parenting that twins receive in their infancy and early childhood. Common problems of adult twins bring about difficulties to adapt in a non-twin world. The nature versus nurture controversy has taken on new life focusing on inter-twin differences and the importance of parent-child interaction as fundamental to the growth and development of personality. PMID:17352324

  15. Metabolismo de glicose em gêmeos monozigóticos discordantes para aptidão cardiorrespiratória Metabolismo de glucosa en gemelos monocigóticos discordantes para aptitud cardiorrespiratoria Glucose metabolism in discordant monozygotic twins for cardiorespiratory fitness

    Directory of Open Access Journals (Sweden)

    Marcos Roberto Queiroga

    2013-03-01

    L.kg-1.min-1 y fueron divididos en dos grupos, de alta y baja aptitud. Los grupos fueron comparados a partir de la prueba pareada de Wilcoxon, teniendo en vista la asimetría de los datos. RESULTADOS: En promedio, los gemelos del grupo de alta aptitud presentaron consumo máximo de oxígeno el 17% superior (13,5±3,7mL.kg-1.min-1 a sus hermanos menos aptos. No hubo diferencia entre los grupos para las concentraciones de insulina (36,5±34,6 versus 25,3±13,7mg/dL; pOBJECTIVE: To determine if glucose and insulin concentrations are regulated by cardiorespiratory fitness (VO2max regardless of their genetic effects. METHODS: This cross-sectional study enrolled 38 pairs of young monozygotic twins (11 to 18 years-old. All subjects underwent a progressive maximal exercise test on a treadmill to determine the VO2max with gas exchange analysis (MedGraphics VO2000® - Medical Graphics Corp., St. Paul, MN. Blood samples were drawn after fasting to determine glucose and insulin levels. Monozygosity was confirmed by genotyping 15 informative genetic markers. Nine pairs had at least 10mL.kg-1.min-1 difference in VO2max and were divided into the more and less active group, according to their VO2max. Mean differences between more and less active groups were evaluated by Wilcoxon's test for paired data. RESULTS: On average, twins from the more active group presented a 17% (13.5±3.7mL.kg-1.min-1 higher VO2max compared to their less active siblings. No significant differences were observed between the groups for fasting insulin (36.5±34.6 versus 25.3±13.7mg/dL; p<0.813. However, the more active twins had lower fasting glucose than the less active ones (82.9±7.3 versus 86.7±7.6mg/dL; p<0.010. CONCLUSIONS: In this case-control study (discordant monozygotic twins, the less active co-twins were characterized by higher fasting plasma glucose levels. This implies that poor cardiorespiratory fitness can be associated with defective glucose metabolism regardless of genetic factors.

  16. The Concordance and Heritability of Type 2 Diabetes in 34,166 Twin Pairs From International Twin Registers

    DEFF Research Database (Denmark)

    Willemsen, G.; Ward, K. J.; Bell, C. G.;

    2015-01-01

    ) (8.0%, range 4.9-13.5%) pairs. Across DISCOTWIN, 720 discordant MZ pairs were identified. Except for the oldest of the Danish cohorts (mean age 79), heritability estimates based on contingency tables were moderate to high (0.47-0.77). From a meta-analysis of all data, the heritability was estimated...... at 72% (95% confidence interval 61-78%). This study demonstrated high T2D prevalence and high heritability for T2D liability across twin cohorts. Therefore, the number of discordant MZ pairs for T2D is limited. By combining national resources, the DISCOTWIN Consortium maximizes the number of discordant...

  17. Super Quantum Discord with Weak Measurements

    OpenAIRE

    Singh, Uttam; Pati, Arun Kumar

    2012-01-01

    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the "super quantum discord", is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a functi...

  18. Quantum discord, local operations, and Maxwell's demons

    International Nuclear Information System (INIS)

    Quantum discord was proposed as a measure of the quantumness of correlations. There are at least three different discordlike quantities, two of which determine the difference between the efficiencies of a Szilard's engine under different sets of restrictions. The three discord measures vanish simultaneously. We introduce an easy way to test for zero discord, relate it to the Cerf-Adami conditional entropy and show that there is no simple relation between the discord and the local distinguishability.

  19. Twin study on transplacental-acquired antibodies and attention deficit/hyperactivity disorder - A pilot study

    DEFF Research Database (Denmark)

    Bilenberg, Niels; Hougaard, David; Norgaard-Pedersen, Bent;

    2011-01-01

    OBJECTIVE: We hypothesize that maternal transplacentally acquired antibodies may cause Attention Deficit/Hyperactivity Disorder (ADHD) symptoms years after birth, and tested the hypothesis in twins discordant for ADHD symptoms. METHOD: In a pre-screened sample of 7793 same sex twin pair's (4...

  20. How Do Friends Influence Smoking Uptake? Findings from Qualitative Interviews with Identical Twins

    Science.gov (United States)

    McLeod, Kim; White, Victoria; Mullins, Robyn; Davey, Claire; Wakefield, Melanie; Hill, David

    2008-01-01

    The smoking behavior of friends is a major risk factor for adolescent smoking uptake. To explore the social context of smoking experimentation and consolidation with a particular focus on friends, the authors interviewed both members of 14 young adult identical twin pairs who were discordant for smoking. The different smoking status of twins was…

  1. Twin pregnancy

    DEFF Research Database (Denmark)

    Sperling, Lene; Tabor, A

    2001-01-01

    Determination of chorionicity is one of the most important issues in the management of twin pregnancy. Modern ultrasound equipment has made it possible to accurately assess placentation already in the first trimester with the lambda sign. With regard to prenatal diagnosis, it is important to know...... the art for clinicians caring for twin pregnancies....

  2. Confined Blood Chimerism in Monochorionic Dizygotic Twins Conceived Spontaneously

    Directory of Open Access Journals (Sweden)

    Takashi Kanda

    2013-05-01

    Full Text Available Traditionally, monochorionicity has been regarded as synonymous with monozygosity. However, several recent cases of monochorionic dizygotic twins have shown that monochorionic twins can be dizygous. We report a rare case of monochorionic diamnionic, gender-discordant twins who were conceived spontaneously. Initially, a monochorionic placenta was diagnosed by ultrasonography at 8 weeks of gestation and then confirmed by pathology after delivery. The twins had different genders. A comparison of cytogenetic analyses using peripheral blood lymphocytes and skin fibroblasts revealed that chimerism was confined to blood cells. We have experienced two cases of monochorionic dizygotic twins since 2003. These cases suggest that monochorionic dizygotic twins are not as rare as previously thought.

  3. Twins with omphalocele in Denmark (1970-1989)

    DEFF Research Database (Denmark)

    Bugge, Merete

    Seven pairs of twins, two monozygotic (MZ), two dizygotic (DZ), and three like-sex pairs of unknown zygosity are described. The twin pairs were all discordant for omphalocele except for one pair of conjoined twins. The 8 infants with omphalocele represent 3.1% of the 253 infants with omphalocele......, ascertained in an almost complete nationwide data set of live- and stillborn infants with abdominal wall defects in two decades in Denmark (1970-1989). The occurrence of twins with omphalocele was not significantly different from the occurrence of twins in the Danish population in the same period. To our...... knowledge this is the first report of the occurrence of twins with omphalocele in a systematic nationwide epidemiological study....

  4. Social predictors of adult asthma: a co-twin case-control study

    OpenAIRE

    Huovinen, E; Kaprio, J.; Laitinen, L; Koskenvuo, M.

    2001-01-01

    BACKGROUND—Environmental factors are needed to explain the observed increase in the prevalence of asthma during recent decades, despite the existence of a recognised genetic component in asthma. A co-twin case-control study was undertaken to examine possible social risk factors for asthma.
METHODS—Asthma diagnoses were based on register data of reimbursed asthma medication. During 17 years follow up of the Finnish twin cohort, 262 twin pairs discordant for incident asthma...

  5. DNA methylation studies using twins: what are they telling us?

    OpenAIRE

    Bell, Jordana T.; Spector, Tim D

    2012-01-01

    Recent studies have identified both heritable DNA methylation effects and differential methylation in disease-discordant identical twins. Larger sample sizes, replication, genetic-epigenetic analyses and longitudinal assays are now needed to establish the role of epigenetic variants in disease.

  6. Operational Significance of Discord: Theory and Experiment

    CERN Document Server

    Gu, Mile; Assad, Syed M; Symul, Thomas; Modi, Kavan; Ralph, Timothy C; Vedral, Vlatko; Lam, Ping Koy

    2012-01-01

    Observations that coherent interactions between non-entangled systems can still exhibit unique quantum behaviour challenged the traditional view that quantum correlations are synonymous with entanglement. In response, quantum discord was proposed to complete the description of all quantum correlations. Nevertheless, explicit protocols that directly exploit discord as a quantum resource have remained elusive. Here, we demonstrate that under certain measurement constraints, discord between bipartite systems directly quantifies a quantum resource that coherent interactions can harness. The inability to access this resource by any other means allows us to use discord to directly quantify this `quantum advantage'. We experimentally encode information within the discordant correlations of two separable Gaussian states. The amount of extra information recovered by coherent interaction is quantified and directly linked with the discord between the states. No entanglement exists at any point of this experiment. Thus w...

  7. Non-commutativity measure of quantum discord

    Science.gov (United States)

    Guo, Yu

    2016-01-01

    Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. PMID:27122226

  8. Non-commutativity measure of quantum discord.

    Science.gov (United States)

    Guo, Yu

    2016-01-01

    Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. PMID:27122226

  9. Marital status and twins' health and behavior: an analysis of middle-aged Danish twins

    DEFF Research Database (Denmark)

    Osler, Merete; McGue, Matt; Lund, Rikke;

    2008-01-01

    concordant on adult marital status. METHODS: A cross-sectional survey of a random sample of middle-aged Danish twins was conducted in 1998 to 1999. This study included 1175 same-sex twin pairs (52.5% monozygotic (MZ) and 47.5% dizygotic (DZ)). Data were obtained on adult marital status and on height, body...... mass index (BMI), depression symptoms, self-rated health, cognitive function, physical activity, smoking, and alcohol intake. RESULTS: Among all 2350 individual twins, men who were divorced/widowed or never married had higher depression scores, lower cognitive test scores, lower physical activity...... scores, and were also less often moderate drinkers and nonsmokers compared with married men. Divorced/widowed women had higher depression scores and those divorced/widowed or never married were more often smokers than married women. Within twin pairs discordant on marital status, the divorced...

  10. Geometric quantum discord under noisy environment

    Science.gov (United States)

    Huang, Zhiming; Qiu, Daowen

    2016-05-01

    In this work, we mainly analyze the dynamics of geometric quantum discord under a common dissipating environment. Our results indicate that geometric quantum discord is generated when the initial state is a product state. The geometric quantum discord increases from zero to a stable value with the increasing time, and the variations of stable values depend on the system size. For different initial product states, geometric quantum discord has some different behaviors in contrast with entanglement. For initial maximally entangled state, it is shown that geometric quantum discord decays with the increasing dissipated time. It is found that for EPR state, entanglement is more robust than geometric quantum discord, which is a sharp contrast to the existing result that quantum discord is more robust than entanglement in noisy environments. However, for GHZ state and W state, geometric quantum discord is more stable than entanglement. By the comparison of quantum discord and entanglement, we find that a common dissipating environment brings complicated effects on quantum correlation, which may deepen our understanding of physical impacts of decohering environment on quantum correlation. In the end, we analyze the effects of collective dephasing noise and rotating noise to a class of two-qubit X states, and we find that quantum correlation is not altered by the collective noises.

  11. Lifetime socioeconomic position and twins' health: an analysis of 308 pairs of United States women twins.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available BACKGROUND: Important controversies exist about the extent to which people's health status as adults is shaped by their living conditions in early life compared to adulthood. These debates have important policy implications, and one obstacle to resolving them is the relative lack of sufficient high-quality data on childhood and adult socioeconomic position and adult health status. We accordingly compared the health status among monozygotic and dizygotic women twin pairs who lived together through childhood (until at least age 14 and subsequently were discordant or concordant on adult socioeconomic position. This comparison permitted us to ascertain the additional impact of adult experiences on adult health in a population matched on early life experiences. METHODS AND FINDINGS: Our study employed data from a cross-sectional survey and physical examinations of twins in a population-based twin registry, the Kaiser Permanente Women Twins Study Examination II, conducted in 1989 to 1990 in Oakland, California, United States. The study population was composed of 308 women twin pairs (58% monozygotic, 42% dizygotic; data were obtained on childhood and adult socioeconomic position and on blood pressure, cholesterol, post-load glucose, body mass index, waist-to-hip ratio, physical activity, and self-rated health. Health outcomes among adult women twin pairs who lived together through childhood varied by their subsequent adult occupational class. Cardiovascular factors overall differed more among monozygotic twin pairs that were discordant compared to concordant on occupational class. Moreover, among the monozygotic twins discordant on adult occupational class, the working class twin fared worse and, compared to her professional twin, on average had significantly higher systolic blood pressure (mean matched difference = 4.54 mm Hg; 95% confidence interval [CI], 0.10-8.97, diastolic blood pressure (mean matched difference = 3.80 mm Hg; 95% CI, 0

  12. Reproduction abnormalities and twin pregnancies in parents of sporadic patients with oculo-auriculo-vertebral spectrum/Goldenhar syndrome.

    NARCIS (Netherlands)

    Wieczorek, D.; Ludwig, M.; Boehringer, S.; Jongbloet, P.H.; Gillessen-Kaesbach, G.; Horsthemke, B.

    2007-01-01

    A great number of case reports on concordant and discordant twins with oculo-auriculo-vertebral spectrum (OAVS) suggest that there might be an association between reproductive abnormalities, twinning and OAVS. The etiology of OAVS is unknown, but may involve epigenetic dysregulation of the oocyte or

  13. Role of quantum discord in quantum communication

    CERN Document Server

    Madhok, Vaibhav

    2011-01-01

    Positivity of quantum discord is shown to be equivalent to the strong sub additivity of the Von-Nuemann entropy. This leads to a connection between the mother protocol of quantum information theory [A. Abeyesinghe, I. Devetak, P. Hayden, and A. Winter, Proc. R. Soc. A 465, 2537, (2009)] and quantum discord. We exploit this to show that quantum discord is a measure coherence in the performance of the mother protocol. Since the mother protocol is a unification of an important class of problems (those that are bipartite, unidirectional and memoryless), we show quantum discord to be a measure of coherence in these protocols. Our work generalizes an earlier operational interpretation of quantum discord provided in terms of quantum state merging [V. Madhok and A. Datta, Phys. Rev. A 83, 032323, (2011)].

  14. Quantum discord in spin-cluster materials

    CERN Document Server

    Yurischev, M A

    2011-01-01

    The total quantum correlation (discord) in Heisenberg dimers is expressed via the spin-spin correlation function, internal energy, specific heat or magnetic susceptibility. This allows one to indirectly measure the discord through neutron scattering, as well as calorimetric or magnetometric experiments. Using the available experimental data, we found the discord for a number of binuclear Heisenberg substances with both antiferro- and ferromagnetic interactions. For the dimerized antiferromagnet copper nitrate Cu(NO_3)_2*2.5H_2O, the three independent experimental methods named above lead to a discord of approximately 0.2-0.3 bit/dimer at a temperature of 4 K. We also determined the temperature behavior of discord for hydrated and anhydrous copper acetates, as well as for the ferromagnetic binuclear copper acetate complex [Cu_2L(OAc)]*6H_2O, where L is a ligand.

  15. Monoamniotic Twins with One Fetal Anencephaly and Cord Entanglement Diagnosed with Three Dimensional Ultrasound at 14 Weeks of Gestation

    Directory of Open Access Journals (Sweden)

    Yun Sung Jo, Hyun Joo Son, Dong Gyu Jang, Narinay Kim, Guisera Lee

    2011-01-01

    Full Text Available A 29-year-old pregnant woman with parity 0-0-0-0 was diagnosed with monoamniotic twin pregnancy discordant for anencephaly at 14 weeks gestation. Umbilical cord entanglement, which is an important cause of fetal death in monoamniotic twins, was confirmed by three-dimensional ultrasound. Cesarean section was performed at 34 weeks of gestation, and the normal newborn infant was discharged without any complications. We report a case of monoamniotic twin pregnancy discordant for anencephaly and diagnosed with cord entanglement by three-dimensional ultrasound at 14 weeks of gestation, and now report it along with a literature review.

  16. Twin Baryogenesis

    CERN Document Server

    Farina, Marco; Shin, Chang Sub

    2016-01-01

    In the context of Twin Higgs models, we study a simple mechanism that simultaneously generates asymmetries in the dark and visible sector through the out-of-equilibrium decay of a TeV scale particle charged under a combination of baryon and twin baryon number. We predict the dark matter to be a 5 GeV twin baryon, which is easy to achieve because of the similarity between the two confinement scales. Dark matter is metastable and can decay to three quarks, yielding indirect detection signatures. The mechanism requires the introduction of a new colored particle, typically within the reach of the LHC, of which we study the rich collider phenomenology, including prompt and displaced dijets, multi-jets, monojets and monotops.

  17. The one-way unlocalizable quantum discord

    CERN Document Server

    Xi, Zhengjun; Li, Yongming

    2012-01-01

    In this paper, we present the concept of the one-way unlocalizable quantum discord and investigate its properties. We provide a polygamy inequality for it in tripartite pure quantum system of arbitrary dimension. Several trade-offs between the one-way unlocalizable quantum discord and other correlations are given. If the von Neumann measurement is on a part of the system, we give two expressions of the one-way unlocalizable quantum discord in terms of partial distillable entanglement and quantum disturbance. Finally, we also provide a lower bound for bipartite shareability of quantum correlation beyond entanglement in a tripartite system.

  18. Does normal variation in birthweight confer susceptibility to health problems? A co-twin control study

    Directory of Open Access Journals (Sweden)

    Jennifer R. Harris m.fl

    2009-10-01

    Full Text Available  ABSTRACTPopulation-based twin data were used to study whether normal variation in birthweight confersdisadvantage for a variety of health outcomes from birth through young adulthood. The sample consists of5,864 identical and fraternal twins and includes 2,570 intact pairs. Variation in birthweight may beassociated with an increased risk for epilepsy in males and with refractive disorders, chronic ear infectionsand intestinal problems in women. Two variants of the co-twin control design, based on identical twinsonly, were used to control for genetic and shared environmental effects that influence both birthweight andthe health outcome. Results indicated that the prevalence of health outcomes was not greater among thelighter twin from birthweight discordant pairs. Furthermore, intra-pair differences in birthweight betweenmembers of pairs who were health-discordant were significant only for nearsightedness among the MZmales. Due to lack of statistical power these results should be interpreted with caution.

  19. Gene expression profiles in Finnish twins with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Kaprio Jaakko

    2006-02-01

    Full Text Available Abstract Background Since genetic alterations influencing susceptibility to multiple sclerosis (MS, the most common autoimmune demyelinating disease of the central nervous system (CNS, are as yet poorly understood, the purpose of this study was to identify genes responsible for MS by studying monozygotic (MZ twin pairs discordant for MS. Methods In order to identify genes involved in MS development, the gene expression profiles in blood mononuclear cells obtained from eight MZ twin pairs discordant for MS were analyzed by cDNA microarray technology detecting the expression of 8 300 genes. The twins were collected from the Finnish Twin Cohort Study and both affected subjects and their healthy siblings underwent neurological evaluation and cerebral and spinal magnetic resonance imaging. Gene expressions were confirmed by relative quantitative reverse transcription PCR. Results It appeared that 25 genes were at least two-fold up-regulated and 15 genes down-regulated in 25% (2/8 of twins with MS when compared to their healthy siblings. Moreover, 6/25 genes were up-regulated in 40% of MS twins and one gene, interferon alpha-inducible protein (clone IFI-6-16 (G1P3, in 50% of them. The six most constantly expressed genes are (1 G1P3, (2 POU domain, class 3, transcription factor 1, (3 myxovirus resistance 2, (4 lysosomal-associated multispanning membrane protein-5, (5 hemoglobin alpha 2 and (6 hemoglobin beta. Conclusion Over two-fold up-regulation of these six genes in almost half of MZ twins with MS suggests their role in MS pathogenesis. Studies using MZ MS twins obtained from genetically homogeneous population offer a unique opportunity to explore the genetic nature of MS.

  20. Guidelines for scanning twins and triplets with US and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Calvo-Garcia, Maria A. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2016-02-15

    Multiple-fetus gestations have an increased risk of discordant anomalies, aneuploidy and growth restriction compared to singleton pregnancies. In addition, twins sharing the same placenta are at risk for developing specific conditions that are potentially amenable to surgical management. In those scenarios, patients might need to be evaluated not only with US but with fetal MRI as well. This paper outlines basic guidelines to consider when imaging complicated multiple-fetus gestations during the 2nd and 3rd trimesters. (orig.)

  1. [Interpair differences in the characteristics of the ontogeny, premorbid personality and severity of schizophrenia in twins].

    Science.gov (United States)

    Moskalenko, V D

    1980-01-01

    In each of the studied 124 pairs, a twin A was distinguished (the patient with manifest symptoms in the discordant pairs, or more seriously affected twin in concordant pairs) and twin B--its partner. It was demonstrated that the order of birth, differences in the weight at birth, periodization of development do not correlate with the differences in the clinical expression of schizophrenia. Such unfavourable factors as asphyxia, complications during delivery, severe somatic illnesses had a certain tendency to accumulate in twin A. The most distinct correlation was found between the traits of a premorbid personality and the eventual intrapair differences in the severeity of schizophrenia. Twin A in the majority of the cases was more excitable in childhood, had more fears, slept worse, and had a poor appetite. The twin A by its premorbid traits was generally characterized by prevalent asthenic features, withdrawal signs and a more dysharmonic type of personality. PMID:7188820

  2. Monocyte Gene-Expression Profiles Associated With Childhood-Onset Type 1 Diabetes and Disease Risk: A Study of Identical Twins

    OpenAIRE

    Beyan, Huriya; Drexhage, Roosmarijn C.; van der Heul Nieuwenhuijsen, Leonie; de Wit, Harm; Padmos, Roosmarijn C.; Schloot, Nanette C; Drexhage, Hemmo A.; Leslie, Richard David

    2010-01-01

    OBJECTIVE Monocytes in childhood-onset type 1 diabetes show distinct gene expression. We hypothesize that monocyte activation in monozygotic (MZ) twin pairs discordant for childhood-onset type 1 diabetes could reflect distinct stages of the disease process including diabetes susceptibility (differences between twins, both diabetic and nondiabetic, and control subjects) and/or disease progression (differences between diabetic and nondiabetic twins). RESEARCH DESIGN AND METHODS We studied patte...

  3. Quantum discord in de Sitter space

    CERN Document Server

    Kanno, Sugumi; Soda, Jiro

    2016-01-01

    We study quantum discord between two free modes of a massive scalar field in a maximally entangled state in de Sitter space. We introduce two observers, one in a global chart and the other in an open chart of de Sitter space, and the observers determine the quantum discord created by each detecting one of the modes. This situation is analogous to the relationship between an observer in a Minkowski chart and another in one of the two Rindler charts in flat space. We find that the state becomes less entangled as the curvature of the open chart gets larger. In particular, for the cases of a massless, and a conformally coupled scalar field, the entanglement vanishes in the limit of infinite curvature. However, we find that the quantum discord never disappears even in the limit that entanglement disappears.

  4. Discordant evaluations of Blacks affect nonverbal behavior.

    Science.gov (United States)

    Olson, Michael A; Fazio, Russell H

    2007-09-01

    Previous research suggests that automatic prejudice directly manifests in nonverbal behavior. The authors offer a more complex picture of the relation between automatic processes and nonverbal behavior by suggesting that any discomfort that appears in nonverbal behavior stems not from negative attitudes per se but from discordance between automatically activated attitudes toward Blacks and the specific evaluations being expressed. White participants for whom estimates of automatic prejudice were available provided videotaped evaluations of several individuals, including two matched Black and White males. Discordance between general racial attitudes and evaluations of specific targets manifested in discomfort-related nonverbal behavior. Moreover, naïve Black judges, but not White judges, doubted the sincerity of individuals characterized by discordance. The nature of the nonverbal "leakage" that automatic prejudice produces is discussed. PMID:17545414

  5. Chorionicity and Heritability Estimates from Twin Studies: The Prenatal Environment of Twins and Their Resemblance Across a Large Number of Traits.

    Science.gov (United States)

    van Beijsterveldt, C E M; Overbeek, L I H; Rozendaal, L; McMaster, M T B; Glasner, T J; Bartels, M; Vink, J M; Martin, N G; Dolan, C V; Boomsma, D I

    2016-05-01

    There are three types of monozygotic (MZ) twins. MZ twins can either share one chorion and one amnion, each twin can have its own amnion, or MZ twins can-like dizygotic twins-each have their own chorion and amnion. Sharing the same chorion may create a more similar/dissimilar prenatal environment and bias heritability estimates, but most twin studies do not distinguish between these three types of MZ twin pairs. The aim of this paper is to investigate the effect of chorion sharing on the similarity within MZ twin pairs for a large number of traits. Information on chorion status was obtained for the Netherlands twin register (NTR) by linkage to the records from the database of the dutch pathological anatomy national automated archive (PALGA). Record linkage was successful for over 9000 pairs. Effect of chorion type was tested by comparing the within-pair similarity between monochorionic (MC) and dichorionic (DC) MZ twins on 66 traits including weight, height, motor milestones, child problem behaviors, cognitive function, wellbeing and personality. For only 10 traits, within-pair similarity differed between MCMZ and DCMZ pairs. For traits influenced by birth weight (e.g. weight and height in young children) we expected that MC twins would be more discordant. This was found for 5 out of 13 measures. When looking at traits where blood supply is important, we saw MCMZ twins to be more concordant than DCMZ's for 3 traits. We conclude that the influence on the MZ twin correlation of the intra-uterine prenatal environment, as measured by sharing a chorion type, is small and limited to a few phenotypes. This implies that the assumption of equal prenatal environment of mono- and DC MZ twins, which characterizes the classical twin design, is largely tenable. PMID:26410687

  6. Predicting Pregnancy in HIV-1-Discordant Couples

    OpenAIRE

    Guthrie, Brandon L.; Choi, Robert Y.; Bosire, Rose; Kiarie, James N.; Mackelprang, Romel D.; Gatuguta, Anne; John-Stewart, Grace C.; FARQUHAR, Carey

    2010-01-01

    This study examines the incidence and predictors of pregnancy in HIV-1-discordant couples from Nairobi, Kenya. Women from 454 discordant couples were followed for up to 2 years. One-year cumulative incidence of pregnancy was 9.7%. Pregnancy rates did not differ significantly between HIV-1-infected and uninfected women (HR = 1.46). The majority of pregnancies occurred among women < 30 years old reporting a desire for future children (1-year incidence 22.2%). Pregnancy rates may be high among d...

  7. Twin Jet

    Science.gov (United States)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  8. Parental Marital Discord and Treatment Response in Depressed Adolescents

    Science.gov (United States)

    Amaya, Meredith M.; Reinecke, Mark A.; Silva, Susan G.; March, John S.

    2011-01-01

    Evidence suggests that parental marital discord contributes to the development of internalizing and externalizing symptoms in children and adolescents. Few studies, however, have examined the association between parental marital discord and youth's response to treatment. The present study examined the impact of interparental discord on treatment…

  9. Metabolic studies in unaffected co-twins of non-insulin-dependent diabetics.

    OpenAIRE

    Barnett, A. H.; Spiliopoulos, A J; Pyke, D. A.; Stubbs, W A; Burrin, J; Alberti, K. G.

    1981-01-01

    Forty-eight out of 53 non-insulin-dependent diabetic identical twin pairs were concordant for diabetes. In the five discordant pairs the diabetic twin had only recently been diagnosed. Oral glucose tolerance tests were carried out on the unaffected twins of the five pairs and on matched controls. Fasting concentrations of blood glucose (5.5 +/- 0.6 v 3.7 +/- 0.3 mmol/l; 99.1 +/- 10.8 v 66.6 +/- 5.4 mg/100 ml), haemoglobin A1 (mean 9.1%, range 8.8-9.2% v mean 7.9%, range 7.4-8.4%), lactate, al...

  10. Twinning in nanocrystalline materials

    International Nuclear Information System (INIS)

    The deformation twinning of nanocrystalline materials is analyzed within the dislocation theory of twins. This approach is used for the description of the recently observed inverse grain size effect in nanocrystalline face-centered-cubic metals. The analytical expressions are obtained for the grain size corresponding to the peak of the twinning propensity, the requisite external stress for twinning propagation in polycrystals and the grain size at which the slip begins to prevail over the twinning. The theoretical results are compared with the experimental data for twinning in Ni and Cu, and given predictions for Al. -- Highlights: ► The inverse grain size effect in Ni and Cu is considered using dislocation theory. ► The twin growth stage of the deformation twinning in nc materials is analyzed. ► The theoretical results are compared with the experimental data for twinning. ► Given predictions the inverse grain size effect for Al.

  11. The Qingdao Twin Registry

    DEFF Research Database (Denmark)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng; Wang, Shaojie; Zhang, Dong; Tan, Qihua; Tian, Xiaocao; Pang, Zengchang

    2013-01-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants of...... metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes...... using twin modeling and genome-wide association analysis. Cross-cultural collaborative studies have been carried out between China, Denmark, Finland, and US cohorts. Ongoing data collection and analysis for the Qingdao Twin Registry will be discussed in this article....

  12. Physically active vs. inactive lifestyle, muscle properties, and glucose homeostasis in middle-aged and older twins

    OpenAIRE

    Leskinen, T.; Sipilä, S.; Kaprio, J.; Kainulainen, H.; Alen, M.; Kujala, U. M.

    2013-01-01

    Exercise-induced positive changes in skeletal muscle properties and metabolism decrease the risk for disability, cardiometabolic diseases and mortality. Here, we studied muscle properties and glucose homeostasis in a non-exercise stage in twin pairs with co-twins discordant for physical activity habits for at least 32 years of their adult lives. Isometric knee extension force, MR imaging of midthigh tissue composition and muscle volume, and fasting blood samples were acquired from 16 same-sex...

  13. Ischiopagus Tripus Conjoined Twins

    Directory of Open Access Journals (Sweden)

    Yousuf Aziz Khan

    2011-03-01

    Full Text Available A conjoined twin is one of the rare congenital defects. Ischiopagus variety is even rarer. We present a case of ischiopagus-tripus conjoined twins. They were fused at the lower halves of the bodies. One of the twins was apparently normal looking, active and pink. The other twin was small, ill looking, sluggish and cyanosed. There were two well formed separate lower limbs on one side and a fused limb at the other side. The twins had an imperforate anus and two small orifices draining urine with incompletely developed external genitalia. Pre-operative workup was in progress when the twins passed away.

  14. Preparing for Twins

    Science.gov (United States)

    ... or fraternal, all twins have their individual personalities, styles, and temperament. Both identical and fraternal twins may ... motor skills while the other perfects social or communication abilities. Because they spend so much time together, ...

  15. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A; Harvald, B; Holm, Niels Vilstrup

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  16. Risk factors for asthma in young adults: a co-twin control study

    DEFF Research Database (Denmark)

    Thomsen, SF; Ulrik, Charlotte Suppli; Kyvik, KO; Larsen, Klaus; Skadhauge, LR; Steffensen, IE; Duffy, DL; Backer, V

    2006-01-01

    BACKGROUND: The liability to asthma is influenced both by genetic and environmental factors. The objective of this study was to identify risk factors for asthma in young adult twin pairs during an 8-year period. METHODS: From the birth cohorts 1953-1982 of the Danish Twin Registry, 6,090 twin pairs....... Pairs in which only one twin developed asthma -- discordant pairs -- were identified and conditional logistic regression was applied to detect effects of risk factors. RESULTS: A total of 126 monozygotic (MZ) and 273 dizygotic (DZ) discordant twin pairs were identified. In MZ twins hay fever (OR = 3...... females = 0.54, 95% CI: 0.36-0.80, P = 0.002), and increasing levels of body mass index (BMI; OR per unit = 1.11, 95% CI: 1.02-1.20, P = 0.009) were significant predictors of asthma. CONCLUSIONS: Hay fever, eczema, female sex, exercise and increasing levels of BMI were risk factors for asthma in young...

  17. A study of diabetes mellitus within a large sample of Australian twins.

    Science.gov (United States)

    Condon, Julianne; Shaw, Joanne E; Luciano, Michelle; Kyvik, Kirsten O; Martin, Nicholas G; Duffy, David L

    2008-02-01

    Twin studies of diabetes mellitus can help elucidate genetic and environmental factors in etiology and can provide valuable biological samples for testing functional hypotheses, for example using expression and methylation studies of discordant pairs. We searched the volunteer Australian Twin Registry (19,387 pairs) for twins with diabetes using disease checklists from nine different surveys conducted from 1980-2000. After follow-up questionnaires to the twins and their doctors to confirm diagnoses, we eventually identified 46 pairs where one or both had type 1 diabetes (T1D), 113 pairs with type 2 diabetes (T2D), 41 female pairs with gestational diabetes (GD), 5 pairs with impaired glucose tolerance (IGT) and one pair with MODY. Heritabilities of T1D, T2D and GD were all high, but our samples did not have the power to detect effects of shared environment unless they were very large. Weight differences between affected and unaffected cotwins from monozygotic (MZ) discordant pairs were large for T2D and GD, but much larger again for discordant dizygotic (DZ) pairs. The bivariate genetic analysis (under the multifactorial threshold model) estimated the genetic correlation between body mass index (BMI) and T2D to be 0.46, and the environmental correlation at only 0.06. PMID:18251672

  18. Ischiopagus Tripus Conjoined Twins

    OpenAIRE

    Yousuf Aziz Khan

    2011-01-01

    A conjoined twin is one of the rare congenital defects. Ischiopagus variety is even rarer. We present a case of ischiopagus-tripus conjoined twins. They were fused at the lower halves of the bodies. One of the twins was apparently normal looking, active and pink. The other twin was small, ill looking, sluggish and cyanosed. There were two well formed separate lower limbs on one side and a fused limb at the other side. The twins had an imperforate anus and two small orifices draining urine wit...

  19. Quantum discord as a resource in quantum communication

    OpenAIRE

    Madhok, Vaibhav; Datta, Animesh

    2012-01-01

    As quantum technologies move from the issues of principle to those of practice, it is important to understand the limitations on attaining tangible quantum advantages. In the realm of quantum communication, quantum discord captures the damaging effects of a decoherent environment. This is a consequence of quantum discord quantifying the advantage of quantum coherence in quantum communication. This establishes quantum discord as a resource for quantum communication processes. We discuss this p...

  20. Relating quantum discord with the quantum dense coding capacity

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin; Qiu, Liang, E-mail: lqiu@cumt.edu.cn; Li, Song; Zhang, Chi [China University of Mining and Technology, School of Sciences (China); Ye, Bin [China University of Mining and Technology, School of Information and Electrical Engineering (China)

    2015-01-15

    We establish the relations between quantum discord and the quantum dense coding capacity in (n + 1)-particle quantum states. A necessary condition for the vanishing discord monogamy score is given. We also find that the loss of quantum dense coding capacity due to decoherence is bounded below by the sum of quantum discord. When these results are restricted to three-particle quantum states, some complementarity relations are obtained.

  1. Differentiating between low and high susceptibility to schizophrenia in twins: the significance of dermatoglyphic indices in relation to other determinants of brain development.

    Science.gov (United States)

    van Oel, C J; Baaré, W F; Hulshoff Pol, H E; Haag, J; Balazs, J; Dingemans, A; Kahn, R S; Sitskoorn, M M

    2001-12-01

    Both the skin and the brain develop from the same ectoderm and it is thought, therefore, that dermatoglyphics are informative for early disturbances in brain development in schizophrenia. This study was aimed at investigating the differences in both digital and palmar dermatoglyphic indices between twins discordant for schizophrenia and control twins. Furthermore, the significance of dermatoglyphic indices in relation to other determinants of brain development with regard to the susceptibility to schizophrenia was investigated. Data on dermatoglyphic indices of the hand and the palm were obtained from 21 same-sex discordant and 37 same-sex control twins. For 19 discordant and 25 control twins, there was also data available on brain volumes. Non-genetic intra-uterine circumstances early in pregnancy (10-13 weeks of gestation) are associated with a susceptibility to schizophrenia, since both the twins with schizophrenia and the unaffected co-twins showed more fluctuating asymmetry of the finger ridges (Pbrain and left hippocampal volumes in differentiating twins with a high susceptibility to schizophrenia from those with a low susceptibility. PMID:11705712

  2. Asymmetric twin Dark Matter

    International Nuclear Information System (INIS)

    We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC

  3. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Ohm Kyvik, Kirsten; Vilstrup Holm, Niels; Christensen, Kaare

    Introduction: The Danish Twin Registry is a unique source for studies of genetic, familial and environmental factors on life events, health conditions and diseases. Content: More than 85,000 twin pairs born 1870-2008 in Denmark. Validity and coverage: Four main ascertainment methods have been...... employed. Completeness of ascertainment varies according to birth cohorts. For birth cohorts 1870-1930 both twins should survive to age 6 years. From 1931-1968 72% of all twin pairs has been ascertained, with complete ascertainment of all live born twins since 1968. CONCLUSION: Because twins have been...... identified independent of traits and on a population basis, the Danish Twin Registry is well suited for studies to understand the influence of genetic and environmental factors for a wide variety of diseases and traits....

  4. Merohedral twins revisited: quinary twins and beyond.

    Science.gov (United States)

    Quiquandon, Marianne; Gratias, Denis; Sirindil, Abdullah; Portier, Richard

    2016-01-01

    A twin is defined as being an external operation between two identical crystals that share a fraction of the atomic structure with no discontinuity from one crystal to the other. This includes merohedral twins, twins by reticular merohedry as well as coherent twins by contact where only the habit plane is shared by the two adjacent crystals (epitaxy). Interesting and original cases appear when the invariant substructure is built with positions belonging to the same {\\bb Z}-module as, for example, the quinary twin structure first drawn by Albrecht Dürer [(1525). The Painter's Manual: a Manual of Measurement of Lines, Areas and Solids by Means of Compass and Ruler. Facsimile Edition (1977), translated with commentary by W. L. Strauss. New York: Abaris Books]. This paper will show that the Dürer twins, once defined in five-dimensional space, are simple merohedral twins, in the sense of Georges Friedel, leaving the five-dimensional lattice invariant. This analysis will be generalized to some other higher-order {\\bb Z}-modules. PMID:26697867

  5. Monozygotic male twins concordant for Beckwith-Wiedemann syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Clemens, M.; McPherson, E.; Sherer, C. [West Penn Hospital, Pittsburgh, PA (United States)]|[Ludwig Institute for Cancer Reseach, LaJolla, CA (United States)] [and others

    1994-09-01

    The Beckwith-Wiedemann syndrome (BWS) is a multiple congenital anomaly syndrome characterized by macrosomia, macro glossia, visceromegaly, characteristic facies, and in some cases omphalocele, hypoglycemia, hemihypertrophy, and risk of embryonal tumors. Most cases occur sporadically in chromosomally normal individuals, but a few BWS patients have anomalies of 11p and others have evidence of microduplications or paternal isodisomy in this region. In some families with autosomal dominant transmission, BWS maps to 11p15.5, but the mechanism of transmission is not fully understood. BWS has been reported in 11 sets of MZ twins, including 10 female pairs (9 discordant and 1 partially concordant) and one male pair concordant for both BWS & dup 15q11.2-q13. We report a pair of premature male MZ twins with macroglossia, postnatal overgrowth, characteristic BWS facies, and mild developmental delay. One twin had hypoglycemia, but neither had omphalocele or hemihypertrophy and serial abdominal ultrasounds have been normal. DNA fingerprinting confirmed monozygosity. Chromosome studies showed a marker 11p14.2 in one twin only, and molecular genetic studies of the 11p15.5 region showed no evidence of duplication or isodisomy in either twin.

  6. Twin-to-Twin Transfusion Syndrome

    OpenAIRE

    Muhammad Rusda; R. Haryono Roeshadi

    2009-01-01

    Twin-to-twin transfusion syndrome (TTTS), umumnya terjadi pada kehamilan kembar monochorion (MC), dimana terjadi donasi darah secara terus menerus dari satu janin ke janin yang lainnya (satu janin bertindak sebagai donor sedangkan janin yang lainnya bertindak sebagai resipien).Kehamilan kembar monokhorion sangat beresiko untuk mendapat berbagai jenis komplikasi, diantaranya: TTTS, pertumbuhan janin terhambat, kematian janin dan persalinan prematur. Mayoritas dari beberapa kompl...

  7. Quantum entanglement and quantum discord in magnetoactive materials (Review Article)

    International Nuclear Information System (INIS)

    The conceptions of quantum entanglement and quantum discord are reviewed. The entropic measures for these informational correlations are presented. The examples which demonstrate the presence of quantum information correlations in different paramagnetic materials with ferro- and antiferromagnetic couplings are given. The temperature behavior of the discord for atomic nuclear spins is considered. The decoherence of quantum states with electron and nuclear spins is discussed.

  8. Oxygen isotopic composition and U-Pb discordance in zircon

    Science.gov (United States)

    Booth, A.L.; Kolodny, Y.; Chamberlain, C.P.; McWilliams, M.; Schmitt, A.K.; Wooden, J.

    2005-01-01

    We have investigated U-Pb discordance and oxygen isotopic composition of zircon using high-spatial resolution ??18O measurement by ion microprobe. ??18O in both concordant and discordant zircon grains provides an indication of the relationship between fluid interaction and discordance. Our results suggest that three characteristics of zircon are interrelated: (1) U-Pb systematics and concomitant age discordance, (2) ??18O and the water-rock interactions implied therein, and (3) zircon texture, as revealed by cathodoluminescence and BSE imaging. A key observation is that U-Pb-disturbed zircons are often also variably depleted in 18O, but the relationship between discordance and ??18O is not systematic. ??18O values of discordant zircons are generally lighter but irregular in their distribution. Textural differences between zircon grains can be correlated with both U-Pb discordance and ??18O. Discordant grains exhibit either a recrystallized, fractured, or strongly zoned CL texture, and are characteristic of 18O depletion. We interpret this to be a result of metamictization, leading to destruction of the zircon lattice and an increased susceptibility to lead loss. Conversely, grains that are concordant have less-expressed zoning and a smoother CL texture and are enriched in 18O. From this it is apparent that various stages of water-rock interaction, as evidenced by systematic variations in ??18O, leave their imprint on both the texture and U-Pb systematics of zircon. Copyright ?? 2005 Elsevier Ltd.

  9. Risk factors for Staphylococcus aureus nasal colonization in Danish middle-aged and elderly twins

    DEFF Research Database (Denmark)

    Andersen, P S; Larsen, Lisbeth Aagaard; Fowler, V G;

    2013-01-01

    Staphylococcus aureus is a human commensal bacterium found in the nasal cavity and other body sites. Identifying risk factors for S. aureus nasal carriage is of interest, as nasal carriage is a risk factor for subsequent invasive infection. We recently investigated the influence of host genetics...... on S. aureus carriage in Danish middle-aged and elderly twins, which indicated no significant heritability that could account for the observed S. aureus carriage. In the present study, we performed a questionnaire-based study of S. aureus colonization on the same cohort of 2,196 Danish middle......-aged and elderly twins to identify specific risk factors for S. aureus nasal colonization, including analyzing the paired twins (n = 478) that were discordant for S. aureus colonization. We found associations between risk factors and S. aureus nasal colonization among middle-aged and elderly twins, including age...

  10. A study of diabetes mellitus within a large sample of Australian twins

    DEFF Research Database (Denmark)

    Condon, Julianne; Shaw, Joanne E; Luciano, Michelle;

    2008-01-01

    Twin studies of diabetes mellitus can help elucidate genetic and environmental factors in etiology and can provide valuable biological samples for testing functional hypotheses, for example using expression and methylation studies of discordant pairs. We searched the volunteer Australian Twin...... Registry (19,387 pairs) for twins with diabetes using disease checklists from nine different surveys conducted from 1980-2000. After follow-up questionnaires to the twins and their doctors to confirm diagnoses, we eventually identified 46 pairs where one or both had type 1 diabetes (T1D), 113 pairs with...... type 2 diabetes (T2D), 41 female pairs with gestational diabetes (GD), 5 pairs with impaired glucose tolerance (IGT) and one pair with MODY. Heritabilities of T1D, T2D and GD were all high, but our samples did not have the power to detect effects of shared environment unless they were very large...

  11. More physics twins

    Science.gov (United States)

    Shemilt, Jane; Hodge, Alison; White, Martin; Dewhurst, Samuel; Evans, Colin J.; Smith, Ron

    2008-02-01

    Your article about the two female physicists in Israel (pictured above) who are identical twins raised the question of whether any other such twins exist (January p3). My identical twin sister and I were both undergraduates at Imperial College, being in the first cohort of students to graduate in materials science in 1973. This was under our maiden names of Jane and Ruth Weston.

  12. Perinatal hepatic infarction in twin-twin transfusion.

    LENUS (Irish Health Repository)

    O'Sullivan, M J

    2012-02-03

    We report a case of a twin pregnancy which was complicated by a twin-twin transfusion in which the recipient twin was noted to have an intra-abdominal echogenic mass. This twin died at two days of age of hepatic infarction. The donor twin was healthy at birth, at thirty weeks\\' gestation, and did not have any subsequent problems. Fetal intra-abdominal echogenicity may be a marker of hepatic infarction.

  13. Subarachnoid haemorrhage in identical twins.

    OpenAIRE

    Schon, F; Marshall, J

    1984-01-01

    A pair of identical twins both of whom died of subarachnoid haemorrhage from ruptured anterior communicating artery aneurysms are reported. These twins are compared to the three other reported twins with ruptured cerebral aneurysms.

  14. Angiographic evaluation of conjoined twins

    International Nuclear Information System (INIS)

    Two sets of conjoined twins were studied by angiocardiography and cerebral angiography. Conjoined heart was demonstrated in the thoracopagus twins and surgical separation was impossible. Cerebral angiography disclosed the separate circulations in craniopagus twins and surgical separation was performed. (orig.)

  15. EFFECTS OF LONG-TERM PHYSICAL ACTIVITY ON CARDIAC STRUCTURE AND FUNCTION: A TWIN STUDY

    Directory of Open Access Journals (Sweden)

    Urho M.Kujala

    2009-12-01

    Full Text Available Previous studies have shown that athletic training or other physical activity causes structural and functional adaptations in the heart, but less is known how long-term physical activity affects heart when genetic liability and childhood environment are taken into account. The aim of this study was to investigate the effects of long-term physical activity vs. inactivity on cardiac structure and function in twin pairs discordant for physical activity for 32 years. Twelve same-sex twin pairs (five monozygotic and seven dizygotic, 50-67 years were studied as a part of the TWINACTIVE study. Discordance in physical activity was initially determined in 1975 and it remained significant throughout the follow-up. At the end of the follow-up in 2007, resting echocardiographic and electrocardiographic measurements were performed. During the follow-up period, the active co-twins were on average 8.2 (SD 4.0 MET hours/day more active than their inactive co-twins (p < 0.001. At the end of the follow-up, resting heart rate was lower in the active than inactive co-twins [59 (SD 5 vs. 68 (SD 10 bpm, p=0.03]. The heart rate-corrected QT interval was similar between the co-twins. Also, there was a tendency for left ventricular mass per body weight to be greater and T wave amplitude in lead II to be higher in the active co-twins (18% and 15%, respectively, p=0.08 for both. Similar trends were found for both monozygotic and dizygotic twin pairs. In conclusion, the main adaptation to long- term physical activity is lowered resting heart rate, even after partially or fully controlling for genetic liability and childhood environment

  16. Apparent discordant redshift QSO-galaxy associations

    CERN Document Server

    Lopez-Corredoira, Martin

    2009-01-01

    An "exotic" idea proposed by Viktor Ambartsumian was that new galaxies are formed through the ejection from older active galaxies. Galaxies beget galaxies, instead of the standard scenario in which galaxies stem from the evolution of the seeds derived from fluctuations in the initial density field. This idea is in some way contained in the speculative proposal that some or all QSOs might be objects ejected by nearby galaxies, and that their redshift is not cosmological (Arp, G./M. Burbidge and others). I will discuss some of the arguments for and against this scenario; in particular, I shall talk about the existence of real physical connections in apparently discordant QSO-galaxy redshift associations. On the one hand, there are many statistical correlations of high-redshift QSOs and nearby galaxies that cannot yet be explained in terms of gravitational lensing, biases, or selection effects; and some particular configurations have very low probabilities of being a projection of background objects. Our underst...

  17. Long-term neurodevelopmental outcome of monochorionic and matched dichorionic twins.

    Directory of Open Access Journals (Sweden)

    Karien E A Hack

    Full Text Available BACKGROUND: Monochorionic (MC twins are at increased risk for perinatal mortality and serious morbidity due to the presence of placental vascular anastomoses. Cerebral injury can be secondary to haemodynamic and hematological disorders during pregnancy (especially twin-to-twin transfusion syndrome (TTTS or intrauterine co-twin death or from postnatal injury associated with prematurity and low birth weight, common complications in twin pregnancies. We investigated neurodevelopmental outcome in MC and dichorionic (DC twins at the age of two years. METHODS: This was a prospective cohort study. Cerebral palsy (CP was studied in 182 MC infants and 189 DC infants matched for weight and age at delivery, gender, ethnicity of the mother and study center. After losses to follow-up, 282 of the 366 infants without CP were available to be tested with the Griffiths Mental Developmental Scales at 22 months corrected age, all born between January 2005 and January 2006 in nine perinatal centers in The Netherlands. Due to phenotypic (unalikeness in mono-or dizygosity, the principal investigator was not blinded to chorionic status; perinatal outcome, with exception of co-twin death, was not known to the examiner. FINDINGS: Four out of 182 MC infants had CP (2.2% - two of the four CP-cases were due to complications specific to MC twin pregnancies (TTTS and co-twin death and the other two cases of CP were the result of cystic PVL after preterm birth - compared to one sibling of a DC twin (0.5%; OR 4.2, 95% CI 0.5-38.2 of unknown origin. Follow-up rate of neurodevelopmental outcome by Griffith's test was 76%. The majority of 2-year-old twins had normal developmental status. There were no significant differences between MC and DC twins. One MC infant (0.7% had a developmental delay compared to 6 DC infants (4.2%; OR 0.2, 95% 0.0-1.4. Birth weight discordancy did not influence long-term outcome, though the smaller twin had slightly lower developmental scores than its

  18. Discord as a quantum resource for bi-partite communication

    Energy Technology Data Exchange (ETDEWEB)

    Chrzanowski, Helen M.; Assad, Syed M.; Symul, Thomas; Lam, Ping Koy [Centre for Quantum Computation and Communication Technology, Department of Quantum Science, The Australian National University (Australia); Gu, Mile; Modi, Kavan; Vedral, Vlatko [Centre for Quantum Technologies, National University of Singapore (Singapore); Ralph, Timothy C. [Centre for Quantum Computation and Communication Technology, Department of Physics, University of Queensland (Australia)

    2014-12-04

    Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising candidate. Here, we experimentally demonstrate that under certain measurement constraints, discord between bipartite systems can be consumed to encode information that can only be accessed by coherent quantum interactions. The inability to access this information by any other means allows us to use discord to directly quantify this ‘quantum advantage’.

  19. Discord as a quantum resource for bi-partite communication

    International Nuclear Information System (INIS)

    Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising candidate. Here, we experimentally demonstrate that under certain measurement constraints, discord between bipartite systems can be consumed to encode information that can only be accessed by coherent quantum interactions. The inability to access this information by any other means allows us to use discord to directly quantify this ‘quantum advantage’

  20. The role of quantum discord in quantum information theory

    International Nuclear Information System (INIS)

    Quantum correlations beyond entanglement - in particular represented by quantum discord - have become a major research field in the last few years. In this talk we report on the role of quantum discord in several fundamental tasks in quantum information theory. Starting with the role of quantum discord in the quantum measurement process, we also discuss its role in the tasks of information sharing and entanglement distribution. Finally, we also show the limits of these results and present possible ways to go beyond these limits.

  1. Phenotypic variability in monozygotic twins with neurofibromatosis 2

    Energy Technology Data Exchange (ETDEWEB)

    Baser, M.E.; Ragge, N.K.; Riccardi, V.M. [UCLA School of Medicine, Los Angeles, CA (United States)] [and others

    1996-09-06

    Mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene on chromosome 22q12 cause a clinically variable autosomal dominant syndrome characterized by bilateral vestibular schwannomas (VSs), other nervous system tumors, and early onset lenticular cataracts. We studied three pairs of monozygotic (MZ) twins with NF2, all with bilateral VSs, to separate genetic from nongenetic causes of clinical variability. The evaluation included gadolinium-enhanced high-resolution magnetic resonance imaging of the head and spine, neuro-ophthalmic examination with slit lamp, physical examination, and zygosity testing with microsatellite markers. Each MZ pair was concordant for general phenotypic subtype (mild or severe) and often for the affected organ systems. However, the MZ pairs were discordant for some features of disease presentation or progression. For example, all three pairs were discordant for presence or type of associated cranial tumors. We hypothesize that phenotypic differences between NF2 MZ twins are at least partly due to stochastic processes, such as the loss of the second NF2 allele or alleles of other genes. 42 refs., 1 tab.

  2. Increased Fetal Plasma Erythropoietin in Monochorionic Twin Pregnancies With Selective Intrauterine Growth Restriction and Abnormal Umbilical Artery Doppler.

    Science.gov (United States)

    Chang, Yao-Lung; Chao, An-Shine; Peng, Hsiu-Huei; Chang, Shuenn-Dyh; Su, Sheng-Yuan; Chen, Kuan-Ju; Cheng, Po-Jen; Wang, Tzu-Hao

    2016-08-01

    Hypoxia is the primary stimulus for the production of erythropoietin (EPO) in both fetal and adult life. Here, we investigated fetal plasma EPO concentrations in monochorionic (MC) twin pregnancies with selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery (UA) Doppler. We diagnosed sIUGR in presence of (1) birth-weight discordance >20% and (2) either twin with a birth weight <10th percentile. An abnormal UA Doppler was defined as a persistent absent-reverse end diastolic flow (AREDF). The intertwin EPO ratio was calculated as the plasma EPO level of the smaller (or small-for-gestational-age) twin divided by the EPO concentration of the larger (or appropriate-for-gestational-age (AGA)) twin. Thirty-two MC twin pairs were included. Of these, 17 pairs were normal twins (Group 1), seven pairs were twins with sIUGR without UA Doppler abnormalities (Group 2), and eight pairs were twins with sIUGR and UA Doppler abnormalities (Group 3). The highest EPO ratio was identified in Group 3 (p < .001) but no significant differences were observed between Groups 1 and 2. Fetal hemoglobin levels did not differ significantly in the three groups, and fetal EPO concentration did not correlate with gestational age at birth. We conclude that fetal plasma EPO concentrations are selectively increased in MC twin pregnancies with sIUGR and abnormal UA Doppler, possibly as a result of uncompensated hypoxia. PMID:27161360

  3. Insights on Solar Twins

    Science.gov (United States)

    Sousa Duarte, Tharcisyo Sa e.; Soares da Costa, Jefferson; Dias do Nascimento Júnior, José

    2015-08-01

    The question about how to define a real solar twin are still active. Cayrel de Strobe et al. (1981) defined a solar twin like a star having at the same time the physical parameters, Teff, gravity, bolometric magnitude, microturbulent velocity, and chemical composition. We presented the more extensive sample of solar twins known to date. From these targets we will study the behavior of the solar twins as a function of fundamentals stellar parameters, effective temperature, luminosity, age, convective envelope mass deepening (1 - M*/M⊙), lithium abundance and rotation period. We selected the solar twins from observations with the spectropolarimeters ESPaDOnS at CFHT and the Narval at TBL and also on literature. All objects have high resolution and high signal to noise. Analyze this sample of solar twins will help us to understand how these stars whether located around of the Sun's place. Our preliminary results show that the lithium abundance presents one clear correlation with stellar age. The (1 - M*/M⊙) values obtained through our method provided good agreement with the solar value. The rotation periods allow us to assess the solar twins as a function of gyrochronology.

  4. Is Chronic Low Back Pain Associated with the Prevalence of Coronary Heart Disease when Genetic Susceptibility Is Considered? A Co-Twin Control Study of Spanish Twins

    Science.gov (United States)

    Fernandez, Matt; Ordoñana, Juan R.; Hartvigsen, Jan; Ferreira, Manuela L.; Refshauge, Kathryn M.; Sánchez-Romera, Juan F.; Pinheiro, Marina B.; Simpson, Stephen J.; Hopper, John L.; Ferreira, Paulo H.

    2016-01-01

    Objective To investigate the chronic low back pain and coronary heart disease relationship, after adjusting for relevant confounders, including genetics. Methods In a cross-sectional design, 2148 twins were recruited from the Murcia Twin Registry, Spain. The exposure was chronic LBP and the outcomes were myocardial infarction and other coronary heart diseases—lifetime and in the last 2 years–based on standardized health-related questionnaires. First, logistic regression analysis investigated associations of the total sample followed by a matched co-twin control analyses, with all complete twin pairs discordant for chronic LBP utilised, separated for zygosity—dizygotic (DZ) and monozygotic (MZ) pairs, which adjusted for shared familial factors, including genetics. Results Chronic LBP pain is associated with lifetime myocardial infarction [odds ratio (OR) = 2.69, 95% confidence interval (CI) = 1.35–5.36], other coronary heart diseases over a lifetime (OR = 2.58, 95% CI: 1.69–3.93) and in the last two years (OR = 2.19, 95% CI: 1.33–3.60), while there was a borderline association with myocardial infarction in the last 2 years (OR = 2.64, 95% CI: 0.98–7.12). Although the magnitude of the association remained or increased in the co-twin control analyses, none reached statistical significance. Conclusion Chronic LBP is associated with a higher prevalence of myocardial infarction and coronary heart disease. It is possible that this association remains even when controlling for genetics and early shared environment, although this should be investigated with larger samples of twins discordant for LBP. PMID:27171210

  5. Past present: Relationship dynamics may differ among discordant gay male couples depending on HIV infection history.

    Science.gov (United States)

    Beougher, Sean C; Mandic, Carmen Gómez; Darbes, Lynae A; Chakravarty, Deepalika; Neilands, Torsten B; Garcia, Carla C; Hoff, Colleen C

    2013-10-01

    Discordant couples are unique because neither partner shares the same serostatus. Yet research overlooks how they became discordant, mistakenly assuming that they have always been that way and, by extension, that being discordant impacts the relationship in a similar manner. This study examines HIV infection history and its impact on relationship dynamics using qualitative data from 35 discordant gay male couples. Most couples met discordant (69%); however, many did not (31%). Those couples that met discordant felt being discordant had a lesser impact on their sexual and relational satisfaction, while those that did not meet discordant felt it had a greater impact, reporting sexual frustration and anxiety over seroconverting. This suggests that relationship dynamics may differ for discordant couples depending on HIV infection history. HIV prevention and counseling services for discordant couples can be better tailored and more effective when differences in HIV infection history are recognized. PMID:24244082

  6. Mechanism of Discordant Alternans in Spatially Homogenoeus Tissue

    CERN Document Server

    Watanabe, M; Evans, S J; Hastings, H; Karma, A; Watanabe, Mari A.; Fenton, Flavio H; Evans, Steven J.; Hastings, Harold; Karma, Alain

    2000-01-01

    Discordant alternans,the phenomenon of 2 separate cardiac tissue locations exhibiting action potential duration (APD) alternans of opposite phase, appears to be a potential mechanism for electrocardiographic T wave alternans, but its initiation mechanism is unknown. We studied behavior of one- and two- dimensional cardiac tissue spatially homogenous in all respects, including APD restitution and conduction velocity restitution, using the Beeler Reuter ion channel model. We found that discordant alternans was initiated when spatial gradients of APD arose dynamically, such as from fixed rate pacing of a cable end (sinus node scenario), or from fixed rate pacing at one site preceded by a single excitation wavefront from another site (ectopic focus scenario). In the sinus node scenario, conduction velocity restitution was necessary to initiate discordant alternans. Alternating regimes of concordant and discordant alternans arose along the length of the cable, with regimes delimited by nodes of fixed APD. The numb...

  7. UNUSUAL CONJOINT TWINS

    OpenAIRE

    Vijayalakshmi,; Sunita

    2013-01-01

    INTRODUCTION: A unique anomaly of multiple pregnancy is conjoined t wins. They are derived from single fertilized ovum occurring in 200 to 2,5 0,000 births with incidence 1 per 50,000 to 1,00,000 live births 1 . Conjoined twinning arises when the twinning event occurs at about the primitive streak stage of development at about 13-14 days after fertilization 2,3 , Conjoined twinning occurs by the incomplete splitting of the em bryonic axis and, with th...

  8. Experimental Verification of Quantum Discord in Continuous-Variable States

    OpenAIRE

    Hosseini, S.; Rahimi-Keshari, S.; Haw, J. Y.; Assad, S. M.; Chrzanowski, H. M.; Janousek, J.; Symul, T.; Ralph, T. C.; Lam, P. K.

    2013-01-01

    We introduce a simple and efficient technique to verify quantum discord in unknown Gaussian states and a certain class of non-Gaussian states. We show that any separation in the peaks of the marginal distributions of one subsystem conditioned on two different outcomes of homodyne measurements performed on the other subsystem indicates correlation between the corresponding quadratures, and hence nonzero discord. We also apply this method to non-Gaussian states that are prepared by overlapping ...

  9. Operational Significance of Discord Consumption: Theory and Experiment

    OpenAIRE

    Gu, Mile; Chrzanowski, Helen M.; Assad, Syed M.; Symul, Thomas; Modi, Kavan; Ralph, Timothy C.; Vedral, Vlatko; Lam, Ping Koy

    2012-01-01

    Coherent interactions that generate negligible entanglement can still exhibit unique quantum behaviour. This observation has motivated a search beyond entanglement for a complete description of all quantum correlations. Quantum discord is a promising candidate. Here, we demonstrate that under certain measurement constraints, discord between bipartite systems can be consumed to encode information that can only be accessed by coherent quantum interactions. The inability to access this informati...

  10. Potential for patient-physician language discordance in Ontario

    OpenAIRE

    Sears, Jennifer; Khan, Kamran; Ardern, Chris I.; Tamim, Hala

    2013-01-01

    Background Patient-Physician language discordance occurs when the patient and physician lack proficiency in the same language(s). Previous literature suggests language discordant clinical encounters compromise patient quality of care and health outcomes. The objective of this study was to quantify and visualize the linguistic and spatial mismatch between Ontario’s population not proficient in English or French but proficient in one of the top five non-official languages and the physicians who...

  11. Phenotypic discordance in a family with monozygotic twins and non-syndromic cleft lip and palate

    Energy Technology Data Exchange (ETDEWEB)

    Wyszynski, D.F. [Johns Hopkins Univ., Baltimore, MD (United States)]|[National Center for Human Genome Research, Bethesda, MD (United States); Lewanda, A.F. [Johnson Hopkins Hospital, Baltimore, MD (United States)]|[Children`s National Medical Center, Washington, DC (United States); Beaty, T.H. [Johns Hopkins Univ., Balitomre, MD (United States)

    1996-12-30

    Despite considerable research, the cause of non-syndromic cleft lip with or without cleft palate (NSCLP) is still an enigma. Case-control and cohort studies have searched for environmental factors that might influence the development of this common malformation, such as maternal cigarette smoking, periconceptional supplementation of folic acid and multivitamins, agricultural chemical use, and place of residence, among others. However, these studies are subject to numerous biases, and their results have often been contradictory and inconclusive. 41 refs., 1 fig.

  12. A Discordant Monozygotic Twin Design Shows Blunted Cortisol Reactivity among Bullied Children

    Science.gov (United States)

    Ouellet-Morin, Isabelle; Danese, Andrea; Bowes, Lucy; Shakoor, Sania; Ambler, Antony; Pariante, Carmine M.; Papadopoulos, Andrew S.; Caspi, Avshalom; Moffitt, Terrie E.; Arseneault, Louise

    2011-01-01

    Objective: Childhood adverse experiences are known to engender persistent changes in stress-related systems and brain structures involved in mood, cognition, and behavior in animal models. Uncertainty remains about the causal effect of early stressful experiences on physiological response to stress in human beings, as the impact of these…

  13. Collapse–revival of quantum discord and entanglement

    International Nuclear Information System (INIS)

    In this paper the correlations dynamics of two atoms in the case of a micromaser-type system is investigated. Our results predict certain quasi-periodic collapse and revival phenomena for quantum discord and entanglement when the field is in Fock state and the two atoms are initially in maximally mixed state, which is a special separable state. Our calculations also show that the oscillations of the time evolution of both quantum discord and entanglement are almost in phase and they both have similar evolution behavior in some time range. The fact reveals the consistency of quantum discord and entanglement in some dynamical aspects. - Highlights: • The correlations dynamics of two atoms in the case of a micromaser-type system is investigated. • A quasi-periodic collapse and revival phenomenon for quantum discord and entanglement is reported. • A phenomenon of correlations revivals different from that of non-Markovian dynamics is revealed. • The oscillations of time evolution of both quantum discord and entanglement are almost in phase in our system. • Quantum discord and entanglement have similar evolution behavior in some time range

  14. Collapse–revival of quantum discord and entanglement

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Xue-Qun, E-mail: xqyan867@tom.com; Zhang, Bo-Ying

    2014-10-15

    In this paper the correlations dynamics of two atoms in the case of a micromaser-type system is investigated. Our results predict certain quasi-periodic collapse and revival phenomena for quantum discord and entanglement when the field is in Fock state and the two atoms are initially in maximally mixed state, which is a special separable state. Our calculations also show that the oscillations of the time evolution of both quantum discord and entanglement are almost in phase and they both have similar evolution behavior in some time range. The fact reveals the consistency of quantum discord and entanglement in some dynamical aspects. - Highlights: • The correlations dynamics of two atoms in the case of a micromaser-type system is investigated. • A quasi-periodic collapse and revival phenomenon for quantum discord and entanglement is reported. • A phenomenon of correlations revivals different from that of non-Markovian dynamics is revealed. • The oscillations of time evolution of both quantum discord and entanglement are almost in phase in our system. • Quantum discord and entanglement have similar evolution behavior in some time range.

  15. Exercise — Exploring Mutuality and Discordance(s Between Sport and Public Health

    Directory of Open Access Journals (Sweden)

    Eling D. de Bruin

    2013-01-01

    Full Text Available Sports is a peer-reviewed scientific journal that revolves around the interdisciplinary area of exercise sciences applied in sport and public health. The intention of Sports is to link several scientific disciplines in an integrated fashion in order to address critical issues related to exercise science, sports and public health. As the first Editor-in-Chief of Sports, I would like to share a few comments about this interdisciplinary field of research by discussing the mutuality and discordances between exercise as it is applied in sports and public health.

  16. Total lymphoid irradiation and discordant cardiac xenografts

    International Nuclear Information System (INIS)

    Total lymphoid irradiation can prolong concordant cardiac xenografts. The effects of total lymphoid irradiation in a discordant xenograft model (guinea pig to rat) were studied with and without adjuvant pharmacologic immunosuppression. Inbred Lewis rats were randomly allocated to one of four groups. Group 1 (n = 6) served as a control group and rats received no immunosuppression. Group 2 (n = 5) received triple-drug therapy that consisted of intraperitoneal azathioprine (2 mg/kg), cyclosporine (20 mg/kg), and methylprednisolone (1 mg/kg) for 1 week before transplantation. Group 3 animals (n = 5) received 15 Gy of total lymphoid irradiation in 12 divided doses over a 3-week period. Group 4 (n = 6) received both triple-drug therapy and total lymphoid irradiation as described for groups 2 and 3. Complement-dependent cytotoxicity assay was performed to determine if a correlation between complement-dependent cytotoxicity and rejection-free interval existed. Rejection was defined as cessation of graft pulsation and was confirmed by histologic test results. Only groups 1 and 2 showed a difference in survival (group 1, 6.9 +/- 1.0 minutes; group 2, 14.2 +/- 2.7 minutes, p = 0.02). Although total lymphoid irradiation did decrease complement-dependent cytotoxicity, linear regression revealed no correlation between complement-dependent cytotoxicity and graft survival (coefficient of correlation, 0.30). Unlike concordant cardiac xenografts, total lymphoid irradiation with or without triple-drug therapy does not prolong graft survival

  17. Total lymphoid irradiation and discordant cardiac xenografts

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, E.; Dresdale, A.R.; Diehl, J.T.; Katzen, N.A.; Aronovitz, M.J.; Konstam, M.A.; Payne, D.D.; Cleveland, R.J. (Tufts Univ. School of Medicine, Boston, MA (USA))

    1990-01-01

    Total lymphoid irradiation can prolong concordant cardiac xenografts. The effects of total lymphoid irradiation in a discordant xenograft model (guinea pig to rat) were studied with and without adjuvant pharmacologic immunosuppression. Inbred Lewis rats were randomly allocated to one of four groups. Group 1 (n = 6) served as a control group and rats received no immunosuppression. Group 2 (n = 5) received triple-drug therapy that consisted of intraperitoneal azathioprine (2 mg/kg), cyclosporine (20 mg/kg), and methylprednisolone (1 mg/kg) for 1 week before transplantation. Group 3 animals (n = 5) received 15 Gy of total lymphoid irradiation in 12 divided doses over a 3-week period. Group 4 (n = 6) received both triple-drug therapy and total lymphoid irradiation as described for groups 2 and 3. Complement-dependent cytotoxicity assay was performed to determine if a correlation between complement-dependent cytotoxicity and rejection-free interval existed. Rejection was defined as cessation of graft pulsation and was confirmed by histologic test results. Only groups 1 and 2 showed a difference in survival (group 1, 6.9 +/- 1.0 minutes; group 2, 14.2 +/- 2.7 minutes, p = 0.02). Although total lymphoid irradiation did decrease complement-dependent cytotoxicity, linear regression revealed no correlation between complement-dependent cytotoxicity and graft survival (coefficient of correlation, 0.30). Unlike concordant cardiac xenografts, total lymphoid irradiation with or without triple-drug therapy does not prolong graft survival.

  18. Regional Differences in Prevalence of HIV-1 Discordance in Africa and Enrollment of HIV-1 Discordant Couples into an HIV-1 Prevention Trial

    OpenAIRE

    Jairam R Lingappa; Lambdin, Barrot; Bukusi, Elizabeth Ann; Ngure, Kenneth; Kavuma, Linda; Inambao, Mubiana; Kanweka, William; Allen, Susan; Kiarie, James N.; Were, Edwin; Manongi, Rachel; Coetzee, David; de Bruyn, Guy; Delany-Moretlwe, Sinead; MAGARET, Amalia

    2008-01-01

    Background: Most HIV-1 transmission in Africa occurs among HIV-1-discordant couples (one partner HIV-1 infected and one uninfected) who are unaware of their discordant HIV-1 serostatus. Given the high HIV-1 incidence among HIV-1 discordant couples and to assess efficacy of interventions for reducing HIV-1 transmission, HIV-1 discordant couples represent a critical target population for HIV-1 prevention interventions and prevention trials. Substantial regional differences exist in HIV-1 preval...

  19. Dogs Discriminate Identical Twins

    Science.gov (United States)

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously. PMID:21698282

  20. Dogs Discriminate Identical Twins

    OpenAIRE

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identificati...

  1. Dogs discriminate identical twins.

    Science.gov (United States)

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously. PMID:21698282

  2. Dialysis for twins

    OpenAIRE

    Gramkow, Ann-Maria; Aarup, Michael; Andersen, Lise Lotte Torvin; Tepel, Martin

    2014-01-01

    A 32-year-old woman with known stage-4 chronic kidney disease due to lupus nephritis presented with twin pregnancy after in vitro fertilization at a gestational age of 24 weeks + 3 days because of imminent preterm labour. Repeated ultrasound evaluations confirmed intrauterine growth restriction in both twins and polyhydramnios as the cause of imminent preterm labour. After initiation of haemodialysis treatment, ultrasound evaluation showed a significant decrease in amniotic fluids, and also r...

  3. UNUSUAL CONJOINT TWINS

    Directory of Open Access Journals (Sweden)

    Vijayalakshmi

    2013-03-01

    Full Text Available INTRODUCTION: A unique anomaly of multiple pregnancy is conjoined t wins. They are derived from single fertilized ovum occurring in 200 to 2,5 0,000 births with incidence 1 per 50,000 to 1,00,000 live births 1 . Conjoined twinning arises when the twinning event occurs at about the primitive streak stage of development at about 13-14 days after fertilization 2,3 , Conjoined twinning occurs by the incomplete splitting of the em bryonic axis and, with the exception of parasitic conjoined twins, all are symmetrical and “ the same parts are always united to the same parts”. Depending upon the site of fusion or non fusio n types of twins may differ, either grossly separable (duplica completa, or grossly inseparable ( duplica incompleta. Embryological classification by Spencer is ventral fusion (87% an d dorsal fusion (13% . Classification of conjoined twins according to external forms of co njunction has been proposed by Leacham. (Table 1.

  4. Specific complications of monochorionic twin pregnancies: twin-twin transfusion syndrome and twin reversed arterial perfusion sequence.

    Science.gov (United States)

    Chalouhi, G E; Stirnemann, J J; Salomon, L J; Essaoui, M; Quibel, T; Ville, Y

    2010-12-01

    Monochorionic twins are subjected to specific complications which originate in either imbalance or abnormality of the single placenta serving two twins. This unequal placental sharing can cause complications including twin-twin transfusion syndrome (TTTS), twin anemia-polycythemia sequence (TAPS), selective intrauterine growth restriction or twin reversed arterial perfusion sequence (TRAP). Monochorionicity also makes the management of these specific complications as well as that of a severe malformation in one twin hazardous since the spontaneous death of one twin exposes the co-twin to a risk of exsanguination into the dead twin and its placenta. The latter is responsible for the death of the co-twin in up to 20% of the cases and in ischemic sequelae in about the same proportions in the survivors. Although the symptoms of all these complications are very different, the keystone of their management comes down to either surgical destruction of the inter-twin anastomoses on the chorionic plate when aiming at dual survival or selective and permanent occlusion of the cord of a severely affected twin aiming at protecting the normal co-twin. This can be best achieved by fetoscopic selective laser coagulation and bipolar forceps cord coagulation respectively. PMID:20855238

  5. Does Educational Status Impact Adult Mortality in Denmark? A Twin Approach

    DEFF Research Database (Denmark)

    Madsen, Mia; Nybo Andersen, Anne-Marie; Christensen, Kaare;

    2010-01-01

    design. The study is based on data from the Danish Twin Registry and Statistics Denmark. Using Cox regression, they estimated hazard ratios for mortality according to the highest attained education among 5,260 monozygotic and 11,088 dizygotic same-sex twin pairs born during 1921-1950 and followed during......To disentangle an independent effect of educational status on mortality risk from direct and indirect selection mechanisms, the authors used a discordant twin pair design, which allowed them to isolate the effect of education by means of adjustment for genetic and environmental confounding per...... 1980-2008. Both standard cohort and intrapair analyses were conducted separately for zygosity, gender, and birth cohort. Educational differences in mortality were demonstrated in the standard cohort analyses but attenuated in the intrapair analyses in all subgroups but men born during 1921-1935, and no...

  6. Discordance Rates Between AMH and FSH in Different Age Groups

    Directory of Open Access Journals (Sweden)

    Selcuk Selcuk

    2014-12-01

    Full Text Available Aim: To evaluate the discordance rates between anti-Mullerian hormone (AMH and follicle stimulating hormone (FSH levels according to different age groups in a cohort of Turkish women. Material and Method: This retrospective study was conducted at infertility clinics of Zeynep Kamil Training and Research Hospital. Patients were divided into 4 groups as %u2264 30 years, 31-35 years, 36-39 years, and %u2265 40 years to evaluate the discordance between AMH and FSH in terms of age. Discordance rates, and median level of AMH and of FSH were determined for each age group. Results: 467 patients who met the inclusion criteria were enrolled in the study. 35.1% (n=164, 28.3% (n=132, 22.7%(n=106, and 13.9% (n=65 of patients were %u2264 30 years, 31-35 years, 36-39 years, and %u2265 40 years, respectively. The discordance rates in terms of normal AMH but abnormal FSH level were 4.2%, 6.7%, 11.0%, 17.9% in the %u2264 30, 31-35, 36-39, %u226540 years age groups, respectively, whereas the discordance rates in terms of normal FSH but abnormal AMH levels were 6.2%, 8.5%, 16.7%, 17.9% in the same age groups, respectively. Discussion: Discordance rates steadily increased with advancing age both for concerning AMH-reassuring FSH and concerning FSH-reassuring AMH. Data from our study and the literature lead us to conclude that age-based AMH and FSH levels and also that discordance between these parameters may vary among different ethnic groups.

  7. Sexually transmitted infections among HIV-1-discordant couples.

    Directory of Open Access Journals (Sweden)

    Brandon L Guthrie

    Full Text Available INTRODUCTION: More new HIV-1 infections occur within stable HIV-1-discordant couples than in any other group in Africa, and sexually transmitted infections (STIs may increase transmission risk among discordant couples, accounting for a large proportion of new HIV-1 infections. Understanding correlates of STIs among discordant couples will aid in optimizing interventions to prevent HIV-1 transmission in these couples. METHODS: HIV-1-discordant couples in which HIV-1-infected partners were HSV-2-seropositive were tested for syphilis, chlamydia, gonorrhea, and trichomoniasis, and HIV-1-uninfected partners were tested for HSV-2. We assessed sociodemographic, behavioral, and biological correlates of a current STI. RESULTS: Of 416 couples enrolled, 16% were affected by a treatable STI, and among these both partners were infected in 17% of couples. A treatable STI was found in 46 (11% females and 30 (7% males. The most prevalent infections were trichomoniasis (5.9% and syphilis (2.6%. Participants were 5.9-fold more likely to have an STI if their partner had an STI (P<0.01, and STIs were more common among those reporting any unprotected sex (OR = 2.43; P<0.01 and those with low education (OR = 3.00; P<0.01. Among HIV-1-uninfected participants with an HSV-2-seropositive partner, females were significantly more likely to be HSV-2-seropositive than males (78% versus 50%, P<0.01. CONCLUSIONS: Treatable STIs were common among HIV-1-discordant couples and the majority of couples affected by an STI were discordant for the STI, with relatively high HSV-2 discordance. Awareness of STI correlates and treatment of both partners may reduce HIV-1 transmission. TRIAL REGISTRATION: ClinicalTrials.gov NCT00194519.

  8. Structural health monitoring (vibration) as a tool for identifying structural alterations of the lumbar spine: a twin control study.

    Science.gov (United States)

    Kawchuk, Gregory N; Hartvigsen, Jan; Edgecombe, Tiffany; Prasad, Narasimha; van Dieen, Jaap H

    2016-01-01

    Structural health monitoring (SHM) is an engineering technique used to identify mechanical abnormalities not readily apparent through other means. Recently, SHM has been adapted for use in biological systems, but its invasive nature limits its clinical application. As such, the purpose of this project was to determine if a non-invasive form of SHM could identify structural alterations in the spines of living human subjects. Lumbar spines of 10 twin pairs were visualized by magnetic resonance imaging then assessed by a blinded radiologist to determine whether twin pairs were structurally concordant or discordant. Vibration was then applied to each subject's spine and the resulting response recorded from sensors overlying lumbar spinous processes. The peak frequency, area under the curve and the root mean square were computed from the frequency response function of each sensor. Statistical analysis demonstrated that in twins whose structural appearance was discordant, peak frequency was significantly different between twin pairs while in concordant twins, no outcomes were significantly different. From these results, we conclude that structural changes within the spine can alter its vibration response. As such, further investigation of SHM to identify spinal abnormalities in larger human populations is warranted. PMID:26964507

  9. Special forms in twin pregnancy – asymmetric conjoined twins

    OpenAIRE

    Anca, FA; Negru, A; Mihart, AE; Grigoriu, C; Bohîlțea, RE

    2015-01-01

    Twin pregnancies generally represent a high-risk pregnancy. However, monozygous twins are real challenges for obstetricians due to the complications that may occur. Among the particular cases of monozygous twins in the University Emergency Hospital of Bucharest, Department of Obstetrics and Gynecology, a monochorial monoamniotic pregnancy with conjoined twins has been described. These particular medical circumstances require a deeper understanding of the vascular anatomical particularities. A...

  10. Experimental Investigation of the Evolution of Gaussian Quantum Discord in an Open System

    CERN Document Server

    Madsen, Lars S; Lassen, Mikael; Andersen, Ulrik L

    2012-01-01

    Gaussian quantum discord is a measure of quantum correlations in Gaussian systems. Using Gaussian discord we quantify the quantum correlations of a bipartite entangled state and a separable two-mode mixture of coherent states. We experimentally analyze the effect of noise addition and dissipation on Gaussian discord and show that the former noise degrades the discord while the latter noise for some states leads to an increase of the discord. In particular, we experimentally demonstrate the near-death of discord by noisy evolution and its revival through dissipation.

  11. Hypoalbuminemia in Donors with Twin-Twin Transfusion Syndrome

    NARCIS (Netherlands)

    Verbeek, L.; Middeldorp, J. M.; Hulzebos, C. V.; Oepkes, D.; Walther, F. J.; Lopriore, E.

    2013-01-01

    Objective: To estimate the differences in albumin levels between donors and recipients with twin-twin transfusion syndrome (TTTS). Methods: We performed a matched case-control study including twin pairs with TTTS treated conservatively (conservative group) or with fetoscopic laser surgery (laser gro

  12. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Christiansen, Lene; Kyvik, Kirsten Ohm; Bødker, Frans L; Hvidberg, Lars; Petersen, Inge; Nielsen, Morten M F; Bingley, Paul; Hjelmborg, Jacob; Tan, Qihua; Holm, Niels V; Vaupel, James W; McGue, Matt; Christensen, Kaare

    2013-01-01

    Over the last 60 years, the resources and the research in the Danish Twin Registry (DTR) have periodically been summarized. Here, we give a short overview of the DTR and a more comprehensive description of new developments in the twenty-first century. First, we outline our experience over the last...... decade of combining questionnaire and survey data with national demographic, social, and health registers in Statistics Denmark. Second, we describe our most recent data collection effort, which was conducted during the period 2008-2011 and included both in-person assessments of 14,000+ twins born 1931......-1969 and sampling of biological material, hereby expanding and consolidating the DTR biobank. Third, two examples of intensively studied twin cohorts are given. The new developments in the DTR in the last decade have facilitated the ongoing research and laid the groundwork for new research directions....

  13. Twin mode rotation method

    International Nuclear Information System (INIS)

    R.G. 1.92 modal combination rules for the response spectrum method design of multiple degrees of freedom (MDOF) piping systems are known to yield highly overestimated results for correlated close modes, so-called ''twin modes.'' These modes occur either when two independent sub-structures of a system possess identical natural frequencies, or when a large mass ratio exists between two coupled sub-structures at tuned natural frequencies. The Twin Mode Rotation (TMR) method aims at removing this unwanted degree of conservatism by performing a rotation of the twin mode pair in the modal space before combining them following R.G. 1.92. The theoretical basis and validation of the method and its practical implementation are presented. Academic problems and real cases in large-scale piping systems are discussed

  14. Relativistic twins or sextuplets?

    CERN Document Server

    Sheldon, E S

    2003-01-01

    A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.

  15. Imaging of conjoined twins

    International Nuclear Information System (INIS)

    The incidence of conjoined twins is estimated to be around 1 in 250,000 live births. There is a distinct female predominance. In this paper the imaging of conjoined twins both antenatally and postnatally is reviewed, in particular taking into consideration recent advances with multidetector CT. Accurate counselling of parents regarding the likely outcome of the pregnancy and the likelihood of successful separation is dependent on good prenatal imaging with ultrasound and MRI. Planning of postnatal surgical separation is aided by accurate preoperative imaging which, depending on the conjoined area, will encompass many imaging modalities, but often relies heavily on CT scanning. (orig.)

  16. Imaging of conjoined twins

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kieran [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Kiely, Edward M.; Spitz, Lewis [Great Ormond Street Hospital for Children, Department of Surgery, London (United Kingdom)

    2006-09-15

    The incidence of conjoined twins is estimated to be around 1 in 250,000 live births. There is a distinct female predominance. In this paper the imaging of conjoined twins both antenatally and postnatally is reviewed, in particular taking into consideration recent advances with multidetector CT. Accurate counselling of parents regarding the likely outcome of the pregnancy and the likelihood of successful separation is dependent on good prenatal imaging with ultrasound and MRI. Planning of postnatal surgical separation is aided by accurate preoperative imaging which, depending on the conjoined area, will encompass many imaging modalities, but often relies heavily on CT scanning. (orig.)

  17. Gene Tree Discordance Causes Apparent Substitution Rate Variation.

    Science.gov (United States)

    Mendes, Fábio K; Hahn, Matthew W

    2016-07-01

    Substitution rates are known to be variable among genes, chromosomes, species, and lineages due to multifarious biological processes. Here, we consider another source of substitution rate variation due to a technical bias associated with gene tree discordance. Discordance has been found to be rampant in genome-wide data sets, often due to incomplete lineage sorting (ILS). This apparent substitution rate variation is caused when substitutions that occur on discordant gene trees are analyzed in the context of a single, fixed species tree. Such substitutions have to be resolved by proposing multiple substitutions on the species tree, and we therefore refer to this phenomenon as Substitutions Produced by ILS (SPILS). We use simulations to demonstrate that SPILS has a larger effect with increasing levels of ILS, and on trees with larger numbers of taxa. Specific branches of the species trees are consistently, but erroneously, inferred to be longer or shorter, and we show that these branches can be predicted based on discordant tree topologies. Moreover, we observe that fixing a species tree topology when performing tests of positive selection increases the false positive rate, particularly for genes whose discordant topologies are most affected by SPILS. Finally, we use data from multiple Drosophila species to show that SPILS can be detected in nature. Although the effects of SPILS are modest per gene, it has the potential to affect substitution rate variation whenever high levels of ILS are present, particularly in rapid radiations. The problems outlined here have implications for character mapping of any type of trait, and for any biological process that causes discordance. We discuss possible solutions to these problems, and areas in which they are likely to have caused faulty inferences of convergence and accelerated evolution. PMID:26927960

  18. How discord underlies the noise resilience of quantum illumination

    Science.gov (United States)

    Weedbrook, Christian; Pirandola, Stefano; Thompson, Jayne; Vedral, Vlatko; Gu, Mile

    2016-04-01

    The benefits of entanglement can outlast entanglement itself. In quantum illumination, entanglement is employed to better detect reflecting objects in environments so noisy that all entanglement is destroyed. Here, we show that quantum discord—a more resilient form of quantum correlations—explains the resilience of quantum illumination. We introduce a quantitative relation between the performance gain in quantum illumination and the amount of discord used to encode information about the presence or absence of a reflecting object. This highlights discords role preserving the benefits of entanglement in entanglement breaking noise.

  19. Entanglement and discord for qubits and higher spin systems

    Indian Academy of Sciences (India)

    A R P Rau

    2014-08-01

    We discuss aspects of entanglement and quantum discord, two of the quantum correlations that are of much interest in the field of quantum information. Their definitions and handling will be discussed, with simple illustrative examples. A specific example is of entanglement decay resulting from a simple dissipative process and how to alter that decay. An analytical prescription for computing quantum discord when a qubit (spin-1/2 or two-level quantum system) is involved is presented along with applications, and its generalization to higher spins (many levels) indicated.

  20. Identical Twins Raised Apart

    Science.gov (United States)

    Farnsworth, David L.

    2015-01-01

    This article describes a bivariate data set that is interesting to students. Indeed, this particular data set, which involves twins and IQ, has sparked more student interest than any other set that I have presented. Specific uses of the data set are presented.

  1. Sleep Terrors in Twins

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-12-01

    Full Text Available In an attempt to clarify the genetic and environmental causes of sleep terrors in childhood, reasearchers in Canada followed 390 pairs of monozygotic and dizygotic twins by assessing the frequency of sleep terrors at 18 and 30 months of age using a questionnaire administered to the biological mothers.

  2. Anaesthesia of conjoined twins.

    Science.gov (United States)

    Kobylarz, Krzysztof

    2014-01-01

    Conjoined twins have been a source of fascination to the public and the medical profession for centuries. Their birth was initially viewed as an ominous sign of impending disaster. Since Middle Ages into the 19th century they were regarded as monstrosities and were exhibited at circuses and sideshows. The frequency of conjoined twins is approximately 1 in 50,000 gestation, but many of them die in utero, are terminated or stillborn. The true incidence is estimated to be 1 in 200,000 live births. This article gives an overview of Siamese twins and of the prenatal diagnosis in assessing the prognosis, anaesthetic and post-natal surgical management and outcome. Anaesthesia for conjoined twins surgery, whether prior to or for separation, is an enormous challenge to the anaesthesiologist. The site and complexity of the conjunction affect management of the airway, an intravenous access, the extent of blood and number of surgical specialties involved. Preoperative assessment and planning with interdisciplinary communication and cooperation is vital to the success of the operations. Meticulous attention to detail, monitoring and vigilance are mandatory. PMID:24858973

  3. Dialysis for twins

    DEFF Research Database (Denmark)

    Gramkow, Ann-Maria; Aarup, Michael; Andersen, L. L. T.;

    2014-01-01

    A 32-year-old woman with known stage-4 chronic kidney disease due to lupus nephritis presented with twin pregnancy after in vitro fertilization at a gestational age of 24 weeks + 3 days because of imminent preterm labour. Repeated ultrasound evaluations confirmed intrauterine growth restriction i...

  4. Amelia in Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Davari Tanha Fatemeh

    2009-04-01

    Full Text Available Limb bud first appears during the third week of gestation with the upper limb buds appearing a few days before the lower limb buds. Complete absence of one or more limbs, called Amelia, occurs prior to the eighth week of gestation. We report a case of Amelia in a twin gestation.

  5. Quantum discord and entanglement in Heisenberg XXZ spin chain after quenches

    OpenAIRE

    Ren, Jie; Wu, Yin-Zhong; Zhu, Shi-Qun

    2012-01-01

    Using the adaptive time-dependent density-matrix renormalization group method, the dynamics of entanglement and quantum discord of a one-dimensional spin-1/2 XXZ chain is studied when anisotropic interaction quenches are applied at different temperatures. The dynamics of the quantum discord and pairwise entanglement between the nearest qubits shows that the entanglement and quantum discord will first oscillate and then approach to a constant value. The quantum discord can be used to predict t...

  6. Quantum discord versus second-order MQ NMR coherence intensity in dimers

    OpenAIRE

    Kuznetsova, E. I.; Zenchuk, A. I.

    2011-01-01

    We consider the quantum discord in a two-particle spin-1/2 system (dimer) governed by the standard multiple quantum (MQ) Hamiltonian and reveal the relation between the discord and the intensity of the second-order MQ coherence. Since the coherence intensities may be measured in experiment, we obtain a method of detecting the quantum discord in experiment. Comparison of discord and concurrence is represented.

  7. Twin Higgs WIMP dark matter

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-01

    Dark matter (DM) without a matter asymmetry is studied in the context of twin Higgs (TH) theories in which the LHC naturalness problem is addressed. These possess a twin sector related to the Standard Model (SM) by a (broken) Z2 symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realization of the TH mechanism, the fraternal twin Higgs, with only a single generation of twin quarks and leptons, and the S U (3 )'×S U (2 )' gauge group. We show that a variety of natural twin-WIMP DM candidates are present (directly linked to the weak scale by naturalness), the simplest and most attractive being the τ' lepton with a mass mτ'>mHiggs/2 , although spin-1 W'± DM and multicomponent DM are also possible (twin baryons are strongly disfavored by tuning). We consider in detail the dynamics of the possibly (meta)stable glueballs in the twin sector, the nature of the twin QCD phase transition, and possible new contributions to the number of relativistic degrees of freedom, Δ Neff . Direct detection signals are below current bounds but accessible in near-future experiments. Indirect detection phenomenology is rich and requires detailed studies of twin hadronization and fragmentation to twin glueballs and quarkonia and their subsequent decay to SM, and possible light twin sector states.

  8. Twin Anemia Polycythemia Sequence: Current Views on Pathogenesis, Diagnostic Criteria, Perinatal Management, and Outcome.

    Science.gov (United States)

    Tollenaar, Lisanne S A; Slaghekke, Femke; Middeldorp, Johanna M; Klumper, Frans J; Haak, Monique C; Oepkes, Dick; Lopriore, Enrico

    2016-06-01

    Monochorionic twins share a single placenta and are connected with each other through vascular anastomoses. Unbalanced inter-twin blood transfusion may lead to various complications, including twin-to-twin transfusion syndrome (TTTS) and twin anemia polycythemia sequence (TAPS). TAPS was first described less than a decade ago, and the pathogenesis of TAPS results from slow blood transfusion from donor to recipient through a few minuscule vascular anastomoses. This gradually leads to anemia in the donor and polycythemia in the recipient, in the absence of twin oligo-polyhydramnios sequence (TOPS). TAPS may occur spontaneously in 3-5% of monochorionic twins or after laser surgery for TTTS. The prevalence of post-laser TAPS varies from 2% to 16% of TTTS cases, depending on the rate of residual anastomoses. Pre-natal diagnosis of TAPS is currently based on discordant measurements of the middle cerebral artery peak systolic velocity (MCA-PSV; >1.5 multiples of the median [MoM] in donors and 8 g/dL), and at least one of the following: reticulocyte count ratio >1.7 or minuscule placental anastomoses. Management includes expectant management, and intra-uterine blood transfusion (IUT) with or without partial exchange transfusion (PET) or fetoscopic laser surgery. Post-laser TAPS can be prevented by using the Solomon laser surgery technique. Short-term neonatal outcome ranges from isolated inter-twin Hb differences to severe neonatal morbidity and neonatal death. Long-term neonatal outcome in post-laser TAPS is comparable with long-term outcome after treated TTTS. This review summarizes the current knowledge after 10 years of research on the pathogenesis, diagnosis, management, and outcome in TAPS. PMID:27068715

  9. Molecular analysis of the gut microbiota of identical twins with Crohn's disease

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Janet; Dicksved, Johan; Halfvarson, Jonas; Rosenquist, Magnus; Jarnerot, Gunnar; Tysk, Curt; Apajalahti, Juha; Engstrand, Lars; Jansson, Janet K.

    2008-03-14

    Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independently of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6, concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group specific primers. The microbial communities were also profiled based on their % G+C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and higher relative abundances of B. ovatus and B. vulgatus. Our results suggest that genetics and/or environmental exposure during childhood in part determine the gut microbial composition. However, CD is associated with dramatic changes in the gut microbiota and this was particularly evident for individuals with ileal CD.

  10. Interparental Conflict and the Children of Discord and Divorce.

    Science.gov (United States)

    Emery, Robert E.

    1982-01-01

    Data on the relation between marital turmoil (i.e., discord and divorce) and behavior problems in children are reviewed. Several parameters of this relation are outlined, including type of marital turmoil, form of the child's behavioral response, sex differences, age effects, parental buffering, and effects of parental psychopathology. (Author/MP)

  11. Revised Definitions of Quantum Dissonance and Quantum Discord

    CERN Document Server

    Zhang, Zhan-jun

    2010-01-01

    We show that all the correlations defined by K. Modi et al [Phys. Rev. Lett. {\\bf 104}, 080501 (2010)] except for the total mutual information should be redefined so that some physical quantities (e.g., the accessible maximal classical correlation and the resultant exact quantum discord) are right.

  12. Brazilian Twin Registry: A Bright Future for Twin Studies/Twin Research: Twin Study of Alcohol Consumption and Mortality; Oxygen Uptake in Adolescent Twins/In the News: Superfecundated Twins In Vietnam; Adolescent Twin Relations; Twin and Triplet Co-Workers; A Special Twin Ultrasound; Monozygotic Twins With Different Skin Color; Identical Twin Returns from Space.

    Science.gov (United States)

    Segal, Nancy L

    2016-06-01

    The establishment of the Brazilian Twin Registry for the study of genetic, social, and cultural influences on behavior is one of eleven newly funded projects in the Department of Psychology at the University of São Paulo. These 11 interrelated projects form the core of the university's Center for Applied Research on Well-Being and Human Behavior. An overview of the planned twin research and activities to date is presented. Next, two recent twin studies are reviewed, one on the relationship between alcohol consumption and mortality, and the other on factors affecting maximal oxygen uptake. Twins cited in the media include the first identified superfecundated twins in Vietnam, adolescent twin relations, twins and triplets who work together, monozygotic twins with different skin tones and a co-twin control study that addresses the effects of space travel. PMID:27121223

  13. Quantum Discord Dynamics in Two Different Non-Markovian Reservoirs

    Institute of Scientific and Technical Information of China (English)

    DING Bang-Fu; WANG Xiao-Yun; LIU Jing-Feng; YAN Lin; ZHAO He-Ping

    2011-01-01

    The quantum discord dynamics of two non-coupled two-level atoms independently interacting with their reservoir is studied under two kinds of non-Markovian conditions,namely,an off-resonant case with atomic transition frequency and a photonic band gap.In the first case,the phenomenon of the quantum discord loss and the oscillatory behavior of the quantum discord can occur by changing the detuning quantity and reducing the spectral coupling width for any initial Bell state.Under the second condition,the trapping phenomenon of the quantum discord can be presented by adjusting the width of gap,that is,the quantum discord of two atoms keep a nonzero constant for a long time.Entanglement,as a kind of quantum correlation without a classical counterpart,plays an important role in quantum information and communication theory,[1,2] quantum teleportation,[3] quantum cryptography[4,5] and universal quantum computing.[6]%We report the first implementation of transparent electrodes in bottom-gate graphene transistors used for photo detection. Compared to conventional nontransparent electrodes, the transparent electrodes allow photons to transmit through to the graphene beneath, providing an enlarged absorption area and thereby giving rise to an enhancement of photocurrent generation. The devices are fabricated with an asymmetric metallization scheme and the experimental results show that the maximum photocurrent density using the transparent electrodes (ITO and Pd/ITO) is over two times higher than that using the nontransparent electrodes (Ti and Pd), indicating a significant enhancement in the performance of graphene photo sensors.

  14. Is Cesarean Delivery Preferable in Twin Pregnancies at >=36 Weeks Gestation?

    Science.gov (United States)

    Dong, Yu; Luo, Zhong-Cheng; Yang, Zu-Jing; Chen, Lu; Guo, Yu-Na; Branch, Ware; Zhang, Jun; Huang, Hong

    2016-01-01

    Background The optimal mode of delivery in twin pregnancies remains controversial. A recent randomized trial did not find any benefit of planned cesarean vs. vaginal delivery at 32–38 weeks gestation, but the trial was not powered to detect a moderate effect. We aimed to evaluate the impact of cesarean delivery on perinatal mortality and severe neonatal morbidity in twin pregnancies at ≥32 weeks through a large database exploration approach with the power to detect moderate risk differences. Methods In a retrospective birth cohort study using the U.S. matched multiple births, 1995–2000 (the available largest multiple birth dataset), we compared perinatal outcomes in twins (n = 181,810 pregnancies) delivered at 32–41 weeks gestation without congenital anomalies. The primary outcome was a composite of perinatal death and severe neonatal morbidity. Cox regression was used to estimate the adjusted hazard ratio (aHR) controlling for the propensity to cesarean delivery, fetal characteristics (sex, birth weight, birth weight discordance, same-sex twin or not) and twin-cluster level dependence. Prospective risks were calculated using the fetuses-at-risk denominators. Results The overall rates of the primary outcome were slightly lower in intended cesarean (6.20%) vs. vaginal (6.45%) deliveries. The aHRs of the primary outcome were in favor of vaginal delivery at 32 (aHR = 1.06, p = 0.03) or 33 (aHR = 1.22, ppregnancies at ≥36 weeks gestation. PMID:27227678

  15. Concordant cerebral oligodendroglioma in identical twins.

    OpenAIRE

    Roelvink, N C; Kamphorst, W; Lindhout, D; Ponssen, H

    1986-01-01

    A case of concordant oligodendroglioma in monozygotic twins is reported. The twins were also concordant for uterine leiomyoma and one twin partner had fibroadenoma and lipoma of the breast and myelofibrosis. As very few cases of concordant glioma in monozygotic twins have been published and no such cases in dizygotic twins, a genetic influence in the aetiology of glioma can only be suggested.

  16. Cardiac Manifestations of Twin-to-Twin Transfusion Syndrome.

    Science.gov (United States)

    Manning, Nicky; Archer, Nick

    2016-06-01

    This review addresses the physiology of monochorionic diamniotic (MC/DA) twins and the potential for twin-twin transfusion syndrome (TTTS). It focuses on the underlying cardiovascular pathophysiology of TTTS and the cardiovascular impact of TTTS for both the recipient and the donor twin. It explains the principles for assessment and monitoring of these cardiovascular changes and how these may be used to guide pregnancy management. Finally, it describes the effect of treatment on the altered hemodynamics and how this can influence pregnancy and perinatal management, as well as longer-term follow-up. PMID:27087122

  17. A Comparison of the Attempts of Quantum Discord and Quantum Entanglement to Capture Quantum Correlations

    CERN Document Server

    Al-Qasimi, Asma

    2010-01-01

    Measurements of Quantum Systems disturb their states. To quantify this non-classical characteristic, Zurek and Ollivier introduced the quantum discord, a quantum correlation which can be nonzero even when entanglement in the system is zero. Discord has aroused great interest as a resource that is more robust against the effects of decoherence and offers exponential speed up of certain computational algorithms. Here, we study general two-level bipartite systems and give general results on the relationship between discord, entanglement, and linear entropy, and identify the states for which discord takes a maximal value for a given entropy or entanglement, thus placing strong bounds on entanglement-discord and entropy-discord relations. We find out that although discord and entanglement are identical for pure states, they differ when generalized to mixed states as a result of the difference in the method of generalization.

  18. Tribute to dr louis keith: twin and physician extraordinaire/twin research reports: influences on asthma severity; chimerism revisited; DNA strand break repair/media reports: twins born apart; elevated twin frequencies; celebrity father of twins; conjoined twinning.

    Science.gov (United States)

    Segal, Nancy L

    2014-10-01

    The International Society for Twin Studies has lost a valued friend and colleague. Dr Louis Keith, Emeritus Professor of Obstetrics and Gynecology at Northwestern University, in Chicago, passed away on Sunday, July 6, 2014. His life and work with twins will be acknowledged at the November 2014 International Twin Congress in Budapest, Hungary. Next, twin research reports on the severity of asthma symptoms, a case of chimerism, and factors affecting DNA breakage and repair mechanisms are reviewed. Media reports cover twins born apart, elevated twin frequencies, a celebrity father of twins, and a family's decision to keep conjoined twins together. PMID:25213730

  19. Conjoined twins in West Africa.

    OpenAIRE

    Mabogunje, O A; Lawrie, J H

    1980-01-01

    12 cases of conjoined twins from West Africa were reported between 1936 and 1978. Eight sets were liveborn and were surgically separated either in local hospitals or abroad. Four were stillborn. Two new cases of stillborn conjoined twins were recently delivered at this hospital. The most common type and the ones most likely to be born alive were the omphalopagi. Surgical separation was successful in 5 cases but the twins separated at Zaria died about a month later. Emergency operations were p...

  20. Genetics and the environment affect the relationship between depression and low back pain: a co-twin control study of Spanish twins.

    Science.gov (United States)

    Pinheiro, Marina B; Ferreira, Manuela L; Refshauge, Kathryn; Colodro-Conde, Lucía; Carrillo, Eduvigis; Hopper, John L; Ordoñana, Juan R; Ferreira, Paulo H

    2015-03-01

    Although the co-occurrence of low back pain (LBP) and depression is common, the nature of this association remains unclear. We aimed to investigate whether symptoms of depression are associated with LBP after adjusting for various confounders, including genetics. We used cross-sectional data from 2148 twins from the Murcia Twin Registry, Spain. All twins answered questions about lifetime prevalence of LBP (outcome variable) and symptoms of depression, collected through two instruments, deriving 3 measures: (1) self-report feelings of depression and anxiety; (2) state depression, and (3) trait depression. First, associations were investigated using logistic regression analysis of the total sample. We performed subsequent matched within-pair twin case-control analyses with all complete twin pairs discordant for LBP regardless of zygosity, and separately for dizygotic and monozygotic pairs. This sequential analysis allows for more precise estimates of the relationship between variables, as in each step, the impact of early shared environment and genetics is further considered. Symptoms of depression and anxiety were associated with higher prevalence of LBP in the total sample analysis (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.31-2.05), and this relationship was stronger in the subsequent case-control analysis (OR, 1.74; 95% CI, 1.13-2.69) and dizygotic case-control analysis (OR, 2.39; 95% CI, 1.39-4.08) but disappeared when the analysis was conducted for monozygotic twins (OR, 0.92; 95% CI, 0.42-2.05). A similar pattern was found for state and trait depression. The depression-LBP relationship disappears when high levels of control for confounding factors are applied and seems to be driven by genetic or environmental factors that influence both conditions. PMID:25679471

  1. Difference Between Identical and Fraternal Twins

    Science.gov (United States)

    ... a family may see the minor differences in identical twins and declare the twins fraternal based on these ... kit back to the laboratory to await results. Identical twins have the same DNA; however, they may not ...

  2. Quantum Discord for Investigating Quantum Correlations without Entanglement in Solids

    CERN Document Server

    Rong, Xing; Jin, Fangzhou; Geng, Jianpei; Feng, Pengbo; Xu, Nanyang; Wang, Ya; Ju, Chenyong; Shi, Mingjun; Du, Jiangfeng

    2012-01-01

    Quantum systems unfold diversified correlations which have no classical counterparts. These quantum correlations have various different facets. Quantum entanglement, as the most well known measure of quantum correlations, plays essential roles in quantum information processing. However, it has recently been pointed out that quantum entanglement cannot describe all the nonclassicality in the correlations. Thus the study of quantum correlations in separable states attracts widely attentions. Herein, we experimentally investigate the quantum correlations of separable thermal states in terms of quantum discord. The sudden change of quantum discord is observed, which captures ambiguously the critical point associated with the behavior of Hamiltonian. Our results display the potential applications of quantum correlations in studying the fundamental properties of quantum system, such as quantum criticality of non-zero temperature.

  3. Gaussian geometric discord in terms of Hellinger distance

    Energy Technology Data Exchange (ETDEWEB)

    Suciu, Serban, E-mail: serban.suciu@theory.nipne.ro; Isar, Aurelian [National Institute of Physics and Nuclear Engineering, P.O.Box MG-6, Bucharest-Magurele (Romania)

    2015-12-07

    In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we address the quantification of general non-classical correlations in Gaussian states of continuous variable systems from a geometric perspective. We give a description of the Gaussian geometric discord by using the Hellinger distance as a measure for quantum correlations between two non-interacting non-resonant bosonic modes embedded in a thermal environment. We evaluate the Gaussian geometric discord by taking two-mode squeezed thermal states as initial states of the system and show that it has finite values between 0 and 1 and that it decays asymptotically to zero in time under the effect of the thermal bath.

  4. Fingerprint Recognition with Identical Twin Fingerprints

    OpenAIRE

    Xunqiang Tao; Xinjian Chen; Xin Yang; Jie Tian

    2012-01-01

    Fingerprint recognition with identical twins is a challenging task due to the closest genetics-based relationship existing in the identical twins. Several pioneers have analyzed the similarity between twins' fingerprints. In this work we continue to investigate the topic of the similarity of identical twin fingerprints. Our study was tested based on a large identical twin fingerprint database that contains 83 twin pairs, 4 fingers per individual and six impressions per finger: 3984 (83*2*4*6)...

  5. MULTIPLE CRITERIA DECISION MAKING:DISCORDANT PREFERENCES AND PROBLEM DESCRIPTION

    Institute of Scientific and Technical Information of China (English)

    Alexey B.PETROVSKY

    2007-01-01

    There are many practical decision problems where decision makers' preferences may be inconsistent and contradictory.In this paper,new methods for ordering and classifying multi-attribute objects by discordant collective preferences are suggested.These methods are based on the theory of multiset metric spaces.The proposed techniques are applied to ranking companies and a competitive selection of projects,which are estimated by several experts upon multiple qualitative criteria.

  6. Risks worth Taking: Safety Agreements among Discordant Gay Couples

    OpenAIRE

    Beougher, Sean C.; Chakravarty, Deepalika; Garcia, Carla C.; Darbes, Lynae A.; Neilands, Torsten B.; Hoff, Colleen C.

    2012-01-01

    As HIV research and prevention efforts increasingly target gay men in relationships, situational factors such as couple serostatus and agreements about sex become central to examinations of risk. Discordant gay couples are of particular interest because the risk of HIV infection is seemingly near-at-hand. Yet little is known about their sexual behaviors, agreements about sex, and safer sex efforts. The present study utilized longitudinal semi-structured, qualitative interviews to explore thes...

  7. Direct scheme for measuring the geometric quantum discord

    CERN Document Server

    Jin, Jia-sen; Yu, Chang-shui; Song, He-shan

    2011-01-01

    We propose a scheme to directly measure the exact value of geometric quantum discord of an arbitrary two-qubit state. We only need to perform the projective measurement in the all anti-symmetric subspace and our scheme is parametrically efficient in contrast to the widely adopted quantum state tomography scheme in the sense of less parameter estimations and projectors. Moreover, the present scheme can be easily realized with the current experimental techniques.

  8. Estimating twin concordance for bivariate competing risks twin data

    DEFF Research Database (Denmark)

    Scheike, Thomas; Holst, Klaus K.; Hjelmborg, Jacob B.

    2014-01-01

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experienced...... the event of interest. Under the assumption that both twins are censored at the same time, we show how to estimate this probability in the presence of right censoring, and as a consequence, we can then estimate the casewise twin concordance. In addition, we can model the magnitude of within pair...... dependence over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer...

  9. Twinning disconnections and basal–prismatic twin boundary in magnesium

    International Nuclear Information System (INIS)

    Recent experiments have revealed that the {1 0 1-bar 2} twin boundaries in hexagonal materials are decorated by (0 0 0 1)/{1 0 1-bar 0} basal–prismatic (BP) facets. The objective of this paper is to investigate the mechanism that leads to the formation of these BP interfaces using atomistic simulations and to carry out their stability analysis under an externally applied shear. We demonstrate that the stability of the BP interface is a consequence of large capillary forces that are caused by differences of the energies of a perfect {1 0 1-bar 2} twin boundary and the BP interface. The latter is formed by the glide of twinning disconnections and therefore agrees with the theory of admissible interfacial defects. This observation implies that the glide of twinning disconnections is a primary mechanism of the twin boundary migration. (paper)

  10. Visual Bias Predicts Gait Adaptability in Novel Sensory Discordant Conditions

    Science.gov (United States)

    Brady, Rachel A.; Batson, Crystal D.; Peters, Brian T.; Mulavara, Ajitkumar P.; Bloomberg, Jacob J.

    2010-01-01

    We designed a gait training study that presented combinations of visual flow and support-surface manipulations to investigate the response of healthy adults to novel discordant sensorimotor conditions. We aimed to determine whether a relationship existed between subjects visual dependence and their postural stability and cognitive performance in a new discordant environment presented at the conclusion of training (Transfer Test). Our training system comprised a treadmill placed on a motion base facing a virtual visual scene that provided a variety of sensory challenges. Ten healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. At the first visit, in an analysis of normalized torso translation measured in a scene-movement-only condition, 3 of 10 subjects were classified as visually dependent. During the Transfer Test, all participants received a 2-minute novel exposure. In a combined measure of stride frequency and reaction time, the non-visually dependent subjects showed improved adaptation on the Transfer Test compared to their visually dependent counterparts. This finding suggests that individual differences in the ability to adapt to new sensorimotor conditions may be explained by individuals innate sensory biases. An accurate preflight assessment of crewmembers biases for visual dependence could be used to predict their propensities to adapt to novel sensory conditions. It may also facilitate the development of customized training regimens that could expedite adaptation to alternate gravitational environments.

  11. Twin classics: research that always inspires/Twin studies: elder twin relationships; Superfecundated twinning in chimpanzees; Conjoined twinning and embryo transfer; Reduced frequency of in vitro multiples/Professional and human interest: first identical twin renal transplant; Identical triplet wedding; Spanakos twins: boxers; Twins in space; Political twins.

    Science.gov (United States)

    Segal, Nancy L

    2015-08-01

    Ten classic works in twin research are described. These volumes are rich in data, interpretation, and impact, and contain life history material that adds depth and dimension to the quantitative findings. Next, research on social relationships in older twins, superfecundated twinning in chimpanzees; effects of embryo transfer on conjoined twinning and the reduced frequency of in vitro multiples is reviewed. Finally, there has been considerable public interest surrounding the first identical twin renal transplant, an identical triplet wedding; identical twin boxers, a twin living in space, and a politically active twin pair. PMID:26148718

  12. Confronting Twin Paradox Acceleration

    Science.gov (United States)

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  13. Twin Higgs WIMP Dark Matter

    CERN Document Server

    García, Isabel García; March-Russell, John

    2015-01-01

    Dark matter (DM) without a matter asymmetry is studied in the context of Twin Higgs (TH) theories in which the LHC naturalness problem is addressed. These possess a twin sector related to the Standard Model (SM) by a (broken) $\\mathbb{Z}_2$ symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realisation of the TH mechanism, the Fraternal Twin Higgs, with only a single generation of twin quarks and leptons, and $SU(3)'\\times SU(2)'$ gauge group. We show that a variety of natural twin-WIMP DM candidates are present (directly linked to the weak scale by naturalness), the simplest and most attractive being the $\\tau^\\prime$ lepton with a mass $m_{\\tau^\\prime} > m_{\\rm Higgs}/2$, although spin-1 $W^{\\prime\\pm}$ DM and multicomponent DM are also possible (twin baryons are strongly disfavoured by tuning). We consider in detail the dynamics of the possibly (meta)stable glueballs in the twin sector, the nature of the twin QCD phase transition, and possible new contributions to th...

  14. TWIN REVERSED ARTERIAL PERFUSION SEQUENCE (TRAP SEQUENCE). THE ACARDIAC /ACEPHALIC TWIN

    OpenAIRE

    S. Saritha; Sumedha S. Anjankar

    2013-01-01

    Twin-Reversed Arterial Perfusion (TRAP sequence) is a rare complication of monochorionic twins (MC, twins sharing one placenta). TRAP sequence is known as acardius or chorioangiopagus parasiticus. It occurs in 1% of monochorionic twin pregnancies and in 1 in 35,000 pregnancies. The risk of recurrence was estimated 1:10,000. TRAP sequence is characterized by a structurally normal pump twin perfusing an anomalous twin. In TRAP syndrome, there is mortality and deformities in both twins. ...

  15. A Computational Discriminability Analysis on Twin Fingerprints

    Science.gov (United States)

    Liu, Yu; Srihari, Sargur N.

    Sharing similar genetic traits makes the investigation of twins an important study in forensics and biometrics. Fingerprints are one of the most commonly found types of forensic evidence. The similarity between twins’ prints is critical establish to the reliability of fingerprint identification. We present a quantitative analysis of the discriminability of twin fingerprints on a new data set (227 pairs of identical twins and fraternal twins) recently collected from a twin population using both level 1 and level 2 features. Although the patterns of minutiae among twins are more similar than in the general population, the similarity of fingerprints of twins is significantly different from that between genuine prints of the same finger. Twins fingerprints are discriminable with a 1.5%~1.7% higher EER than non-twins. And identical twins can be distinguished by examine fingerprint with a slightly higher error rate than fraternal twins.

  16. Geometric picture of quantum discord for two-qubit quantum states

    CERN Document Server

    Shi, Mingjun; Sun, Chunxiao; Du, Jiangfeng

    2011-01-01

    Among various definitions of quantum correlations, quantum discord has attracted considerable attention. To find analytical expression of quantum discord is an intractable task. Exact results are known only for very special states, namely, two-qubit X-shaped states. We present in this paper a geometric viewpoint, from which two-qubit quantum discord can be described clearly. The known results about X state discord are restated in the directly perceivable geometric language. As a consequence, the dynamics of classical correlations and quantum discord for an X state in the presence of decoherence is endowed with geometric interpretation. More importantly, we extend the geometric method to the case of more general states, for which numerical as well as analytica results about quantum discord have not been found yet. Based on the support of numerical computations, some conjectures are proposed to help us establish geometric picture. We find that the geometric picture for these states has intimate relationship wit...

  17. Paraphilic Sexual Interests and Sexually Coercive Behavior: A Population-Based Twin Study.

    Science.gov (United States)

    Baur, Elena; Forsman, Mats; Santtila, Pekka; Johansson, Ada; Sandnabba, Kenneth; Långström, Niklas

    2016-07-01

    Prior research with selected clinical and forensic samples suggests associations between paraphilic sexual interests (e.g., exhibitionism and sexual sadism) and sexually coercive behavior. However, no study to date used a large, representative and genetically informative population sample to address the potential causal nature of this association. We used self-report data on paraphilic and sexually coercive behavior from 5990 18- to 32-year-old male and female twins from a contemporary Finnish population cohort. Logistic regression and co-twin control models were employed to examine if paraphilic behaviors were causally related to coercive behavior or if suggested links were confounded by familial (genetic or common family environment) risk factors. Results indicated that associations between four out of five tested paraphilic behaviors (exhibitionism, masochism, sadism, and voyeurism, respectively) and sexually coercive behavior were moderate to strong. Transvestic fetishism was not independently associated with sexual coercion. Comparisons of twins reporting paraphilic behavior with their paraphilic behavior-discordant twin further suggested that associations were largely independent of shared genetic and environmental confounds, consistent with a causal association. In conclusion, similar to previously reported predictive effects of paraphilias on sexual crime recidivism, paraphilic behavior among young adults in the general population increases sexual offending risk. Further, early identification of paraphilic interest and preventive interventions with at-risk individuals might also reduce perpetration of first-time sexual violence. PMID:26754158

  18. Effect of serotesting with counselling on condom use and seroconversion among HIV discordant couples in Africa.

    OpenAIRE

    Allen, S.; Tice, J.; Van de Perre, P; Serufilira, A.; Hudes, E.; Nsengumuremyi, F.; Bogaerts, J; Lindan, C.; Hulley, S.

    1992-01-01

    OBJECTIVE--To determine whether HIV testing and counselling increased condom use and decreased heterosexual transmission of HIV in discordant couples. DESIGN--Prospective study. SETTING--Kigali, the capital of Rwanda. SUBJECTS--Cohabiting couples with discordant HIV serology results. MAIN OUTCOME MEASURES--Condom use in the couple and HIV seroconversion in the negative partners. RESULTS--60 HIV discordant couples were identified, of whom 53 were followed for an average of 2.2 years. The propo...

  19. Comparison of quantum discord and local quantum uncertainty in a vertical quantum dot

    OpenAIRE

    Faizi, E.; Eftekhari, H.

    2014-01-01

    In this paper, we consider quantum correlations (quantum discord and local quantum uncertainty) in a vertical quantum dot. Their dependencies on magnetic field and temperature are presented in detail. It is noticeable that, quantum discord and local quantum uncertainty behavior is similar to a large extent. In addition, the time evolution of quantum discord and local quantum uncertainty under dephasing and amplitude damping channels is investigated. It has been found that, for some Belldiagon...

  20. Delayed initiation of antiretroviral therapy among HIV-discordant couples in Kenya

    OpenAIRE

    Kahn, Talia R.; Desmond, Michelle; Rao, Deepa; Marx, Grace E.; Guthrie, Brandon L.; Bosire, Rose; Choi, Robert Y.; Kiarie, James N; Farquhar, Carey

    2012-01-01

    Timely initiation of antiretroviral therapy (ART) is particularly important for HIV-discordant couples because viral suppression greatly reduces the risk of transmission to the uninfected partner. To identify issues and concerns related to ART initiation among HIV-discordant couples, we recruited a subset of discordant couples participating in a longitudinal study in Nairobi to participate in in-depth interviews and focus group discussions about ART. Our results suggest that partners in HIV-d...

  1. Twins and Kindergarten Separation: Divergent Beliefs of Principals, Teachers, Parents, and Twins

    Science.gov (United States)

    Gordon, Lynn Melby

    2015-01-01

    Should principals enforce mandatory separation of twins in kindergarten? Do school separation beliefs of principals differ from those of teachers, parents of twins, and twins themselves? This survey questioned 131 elementary principals, 54 kindergarten teachers, 201 parents of twins, and 112 twins. A majority of principals (71%) believed that…

  2. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors. PMID:26430985

  3. Twin Higgs Asymmetric Dark Matter

    CERN Document Server

    García, Isabel García; March-Russell, John

    2015-01-01

    We study Asymmetric Dark Matter (ADM) in the context of the minimal (Fraternal) Twin Higgs solution to the little hierarchy problem, with a twin sector with gauged $SU(3)' \\times SU(2)'$, a twin Higgs, and only third generation twin fermions. Naturalness requires the QCD$^\\prime$ scale $\\Lambda'_{\\rm QCD} \\simeq 0.5 - 20 \\ {\\rm GeV}$, and $t'$ to be heavy. We focus on the light $b'$ quark regime, $m_{b'} \\lesssim \\Lambda'_{\\rm QCD}$, where QCD$^\\prime$ is characterised by a single scale $\\Lambda'_{\\rm QCD}$ with no light pions. A twin baryon number asymmetry leads to a successful DM candidate: the spin-3/2 twin baryon, $\\Delta' \\sim b'b'b'$, with a dynamically determined mass ($\\sim 5 \\Lambda'_{\\rm QCD}$) in the preferred range for the DM-to-baryon ratio $\\Omega_{\\rm DM}/\\Omega_{\\rm baryon} \\simeq 5$. Gauging the $U(1)'$ group leads to twin atoms ($\\Delta'$ - $\\bar {\\tau'}$ bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo ...

  4. Playing a Musical Instrument as a Protective Factor against Dementia and Cognitive Impairment: A Population-Based Twin Study

    Science.gov (United States)

    Pedersen, Nancy L.

    2014-01-01

    Increasing evidence supports that playing a musical instrument may benefit cognitive development and health at young ages. Whether playing an instrument provides protection against dementia has not been established. In a population-based cotwin control study, we examined the association between playing a musical instrument and whether or not the twins developed dementia or cognitive impairment. Participation in playing an instrument was taken from informant-based reports of twins' leisure activities. Dementia diagnoses were based on a complete clinical workup using standard diagnostic criteria. Among 157 twin pairs discordant for dementia and cognitive impairment, 27 pairs were discordant for playing an instrument. Controlling for sex, education, and physical activity, playing a musical instrument was significantly associated with less likelihood of dementia and cognitive impairment (odds ratio [OR] = 0.36 [95% confidence interval 0.13–0.99]). These findings support further consideration of music as a modifiable protective factor against dementia and cognitive impairment. PMID:25544932

  5. Successful separation of Xipho-Omphalopagus twins

    OpenAIRE

    Oak S; Joshi R; Parelkar Sandesh; Bhat Uday; Satish Kumar K

    2007-01-01

    Xipho-omphalopagus twins are conjoined twins sharing some part of gastrointestinal system and lower sternum. These types of twins have best chances of survival if successfully separated. We report a case of successfully separated Xipho-omphalopagus twins, highlighting the importance of proper planning and team effort in such separations.

  6. History of treatment of conjoined twins.

    Science.gov (United States)

    Kobylarz, Krzysztof

    2014-01-01

    This paper presents a history of the treatment of conjoined twins. The first mention of this malformation comes from the Neolithic period. Conjoined twins were depicted in mythologies of ancient peoples. The present paper focuses on the theories of formation of Siamese twins and attempts at their separation. Moreover, the history of treatment of conjoined twins in Poland is described. PMID:24858972

  7. Successful separation of Xipho-Omphalopagus twins

    Directory of Open Access Journals (Sweden)

    Oak S

    2007-01-01

    Full Text Available Xipho-omphalopagus twins are conjoined twins sharing some part of gastrointestinal system and lower sternum. These types of twins have best chances of survival if successfully separated. We report a case of successfully separated Xipho-omphalopagus twins, highlighting the importance of proper planning and team effort in such separations.

  8. Twin intersection mechanisms in nanocrystalline fcc metals

    International Nuclear Information System (INIS)

    Deformation twins have been reported to produce high strength and ductility. Intersections of deformation twins may affect the microstructural evolution during plastic deformation and consequently influence mechanical properties. However, the mechanisms governing twin-intersection behavior remain poorly understood. In this study, we investigated twin intersection mechanisms by observing twin transmission across the boundary of another twin using high-resolution transmission electron microscopy. Based on the experimental observations, mechanisms were proposed for twin–twin intersections and associated dislocation reactions in nanocrystalline fcc materials

  9. The vector-like twin Higgs

    Science.gov (United States)

    Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; Strassler, Matthew

    2016-07-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  10. The Vector-like Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Longhi, Pietro; Strassler, Matthew

    2016-01-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  11. Conjoined twins: Radiological experience.

    Science.gov (United States)

    Watson, Sarah G; McHugh, Kieran

    2015-10-01

    Imaging plays a key role in the management of conjoined twins. Pre-operative multi-modality studies are vital to assess operability and to aid surgical planning. Technical advances in imaging such as high-resolution isovolumetric magnetic resonance imaging (MRI) techniques and three-dimensional modeling now result in extremely accurate anatomical information. Varied information from a comprehensive radiological work-up enables the surgeons to plan the safest possible operative procedure, helps the anesthetic team before and during surgery, and guides the intensive care team in the post-operative phase. This article will review the radiological techniques used in our institution, highlighting potential pitfalls with the various imaging modalities. PMID:26382258

  12. Failure of vincristine induce twinning

    Science.gov (United States)

    Binder, M.

    1984-01-01

    Mammalian ova do not contain axes of symmetry from which are derived embryonic axes of symmetry. Mammalian axis determination is an early embryologic event occurring at about the time that monozygous twinning in mice. (Kaufma MH & O'Shea KS, 1978, Nature 276:707) and an attempt was made to reproduce their work in several strains of mice. Over 3200 embryos were examined without any twins being found. To rule out the possibility that vincristine caused twinning plus some lethal malformation (with subsequent resorption of the embryo) the embryos were examined 36-60 hours after vincristine treatment.

  13. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-01

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties. PMID:19687534

  14. Staged separation of craniopagus twins.

    Science.gov (United States)

    Dunaway, David; Jeelani, N U Owase

    2015-10-01

    Craniopagus twins are rare and account for up to 6% of all conjoined twins. No hospital will encounter many such twins and the opportunity to develop expertise is limited. We have dealt with 2 such sets and illustrate our approach by reference to our most recent set. We believe that detailed imaging allows precise delineation of the anatomy and facilitates detailed planning of the surgery. When venous drainage from the 2 brains is connected, we believe that staged separation is preferable as gradual alteration of hemodynamics may be safer than a single-stage procedure. PMID:26382265

  15. Special forms in twin pregnancy – asymmetric conjoined twins

    Science.gov (United States)

    Anca, FA; Negru, A; Mihart, AE; Grigoriu, C; Bohîlțea, RE

    2015-01-01

    Twin pregnancies generally represent a high-risk pregnancy. However, monozygous twins are real challenges for obstetricians due to the complications that may occur. Among the particular cases of monozygous twins in the University Emergency Hospital of Bucharest, Department of Obstetrics and Gynecology, a monochorial monoamniotic pregnancy with conjoined twins has been described. These particular medical circumstances require a deeper understanding of the vascular anatomical particularities. An accurate diagnosis implies a most detailed description of the morphological dynamics of the fetuses with the study of the impact of the vascular anomaly on their development so that the maximum chances of survival and the best outcome for the viable fetus can be obtained. The diagnosis of the most frequently associated anomalies is also extremely important. Abbreviations: MRI = Magnetic resonance imaging PMID:26361519

  16. Special forms in twin pregnancy - asymmetric conjoined twins.

    Science.gov (United States)

    Anca, F A; Negru, A; Mihart, A E; Grigoriu, C; Bohîlțea, R E

    2015-01-01

    Twin pregnancies generally represent a high-risk pregnancy. However, monozygous twins are real challenges for obstetricians due to the complications that may occur. Among the particular cases of monozygous twins in the University Emergency Hospital of Bucharest, Department of Obstetrics and Gynecology, a monochorial monoamniotic pregnancy with conjoined twins has been described. These particular medical circumstances require a deeper understanding of the vascular anatomical particularities. An accurate diagnosis implies a most detailed description of the morphological dynamics of the fetuses with the study of the impact of the vascular anomaly on their development so that the maximum chances of survival and the best outcome for the viable fetus can be obtained. The diagnosis of the most frequently associated anomalies is also extremely important. PMID:26361519

  17. Prevalence of discordant microscopic changes with automated CBC analysis

    Directory of Open Access Journals (Sweden)

    Fabiano de Jesus Santos

    2014-12-01

    Full Text Available Introduction:The most common cause of diagnostic error is related to errors in laboratory tests as well as errors of results interpretation. In order to reduce them, the laboratory currently has modern equipment which provides accurate and reliable results. The development of automation has revolutionized the laboratory procedures in Brazil and worldwide.Objective:To determine the prevalence of microscopic changes present in blood slides concordant and discordant with results obtained using fully automated procedures.Materials and method:From January to July 2013, 1,000 hematological parameters slides were analyzed. Automated analysis was performed on last generation equipment, which methodology is based on electrical impedance, and is able to quantify all the figurative elements of the blood in a universe of 22 parameters. The microscopy was performed by two experts in microscopy simultaneously.Results:The data showed that only 42.70% were concordant, comparing with 57.30% discordant. The main findings among discordant were: Changes in red blood cells 43.70% (n = 250, white blood cells 38.46% (n = 220, and number of platelet 17.80% (n = 102.Discussion:The data show that some results are not consistent with clinical or physiological state of an individual, and cannot be explained because they have not been investigated, which may compromise the final diagnosis.Conclusion:It was observed that it is of fundamental importance that the microscopy qualitative analysis must be performed in parallel with automated analysis in order to obtain reliable results, causing a positive impact on the prevention, diagnosis, prognosis, and therapeutic follow-up.

  18. Diagnosis and Management of Twin-Twin Transfusion Syndrome.

    Science.gov (United States)

    Johnson, Anthony

    2015-09-01

    Twin-twin transfusion syndrome (TTTS) affects 10% to 15% of monochorionic pregnancies. In the absences of timely diagnosis and intervention perinatal loss or long term developmental delay can be expected in over 90% of cases. Establishing chorionicity in the first trimester followed by serial ultrasounds beginning at 16 weeks of gestation and intervention with placental laser ablation before the development of advance disease overall survival rates can be expected in 70% to 80% of cases. PMID:26165181

  19. Twinning disconnections and basal-prismatic twin boundary in magnesium

    Czech Academy of Sciences Publication Activity Database

    Ostapovets, Andriy; Gröger, Roman

    2014-01-01

    Roč. 22, č. 2 (2014), s. 1-10. ISSN 0965-0393 R&D Projects: GA ČR GPP108/12/P054; GA MŠk(CZ) EE2.3.30.0063 Grant ostatní: OP VK(XE) CZ.1.07/2.3.00/30.0063 Institutional support: RVO:68378271 ; RVO:68081723 Keywords : disconnections, , , * twinning * twin boundary * magnesium Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.167, year: 2014

  20. Entanglement, discord and the power of quantum computing

    CERN Document Server

    Brodutch, Aharon

    2010-01-01

    It is impossible to implement an entangling bipartite quantum operation with local operations and classical communication (LOCC) without a shared entanglement. When the operation is restricted to act on unentangled input states that are transformed into unentangled outputs, it may seem that the implementation by LOCC alone is possible. We present an example where this assertion fails. Non-zero quantum discord, which is a measure of quantumness of correlations even in the absence of entanglement, may indicate the failure of the LOCC implementation without entanglement.

  1. Quantum discord as a resource for quantum cryptography.

    Science.gov (United States)

    Pirandola, Stefano

    2014-01-01

    Quantum discord is the minimal bipartite resource which is needed for a secure quantum key distribution, being a cryptographic primitive equivalent to non-orthogonality. Its role becomes crucial in device-dependent quantum cryptography, where the presence of preparation and detection noise (inaccessible to all parties) may be so strong to prevent the distribution and distillation of entanglement. The necessity of entanglement is re-affirmed in the stronger scenario of device-independent quantum cryptography, where all sources of noise are ascribed to the eavesdropper. PMID:25378231

  2. Presence and Acquired Origin of Reduced Recall for Fear Extinction in PTSD: Results of a Twin Study

    Science.gov (United States)

    Milad, Mohammed R.; Orr, Scott P.; Lasko, Natasha B.; Chang, Yuchiao; Rauch, Scott L.; Pitman, Roger K.

    2008-01-01

    Recall of fear extinction, which is thought to aid in recovery from a psychologically traumatic event, is hypothesized to be deficient in post-traumatic stress disorder (PTSD), but this has not yet been demonstrated in the laboratory, nor has its origin been investigated. To address these two issues, 14 pairs of monozygotic twins discordant for combat exposure, in 7 of which the combat-exposed twin had PTSD, underwent a two-day fear conditioning and extinction procedure. On Day 1, subjects viewed colored light conditioned stimuli, some of which were paired with mild electric shock, followed by extinction of the conditioned responses. On Day 2, recall of Day 1 extinction learning (i.e., extinction retention) was assessed. Skin conductance response (SCR) was the dependent measure. There were no group differences during acquisition or extinction learning. However, a significant PTSD Diagnosis (in the exposed twin) x combat Exposure interaction emerged during extinction recall, with the PTSD combat veterans having larger SCRs than their own co-twins, and than the non-PTSD combat veterans and their co-twins. These results indicate that retention of extinction of conditioned fear is deficient in PTSD. Furthermore, they support the conclusion that this deficit is acquired as a result of combat trauma leading to PTSD, rather than being a predisposing factor to developing PTSD upon the stress of combat. PMID:18313695

  3. Thanatophoric dysplasia in identical twins.

    OpenAIRE

    Young, I D; Patel, I; Lamont, A C

    1989-01-01

    Female twins concordant for thanatophoric dysplasia are presented. Monozygosity was confirmed using minisatellite DNA genetic fingerprinting. The evidence supporting new dominant mutations as the likely cause of thanatophoric dysplasia is reviewed.

  4. Simultaneous Intussusception in Monozygotic Twins

    Directory of Open Access Journals (Sweden)

    Mete Kaya

    2014-12-01

    Full Text Available In this case report, it was aimed to present the simultaneously occurring intussusception in the monozygotic twins. In addition to genetic predisposition, environmental factors has been hypothesized to be responsible for the development of the disease.

  5. The Danish political twin study

    DEFF Research Database (Denmark)

    Klemmensen, Robert; Hobolt, Sara B; Dinesen, Peter Thisted;

    2012-01-01

    We compare a recent Danish twin survey on political attitudes and behaviors to a nationally representative survey covering similar topics. We find very similar means and variances for most of our constructed scales of political attitudes and behaviors in the two surveys, although even small...... differences tend to be statistically significant due to sample size. This suggests that the twin study can be used to make inferences on the heritability of several political traits in the Danish population....

  6. A Generalized Geometric Measurement of Quantum Discord: Exact Treatment

    Science.gov (United States)

    Hai-Tao, Cui; Jun-Long, Tian; Gui, Yang

    2016-02-01

    A generalization of the geometric measure of quantum discord is introduced in this article, based on Hellinger distance. Our definition has virtues of computability and independence of local measurement. In addition it also does not suffer from the recently raised critiques about quantum discord. The exact result can be obtained for bipartite pure states with arbitrary levels, which is completely determined by the Schmidt decomposition. For bipartite mixed states the exact result can also be found for a special case. Furthermore the generalization into multipartite case is direct. It is shown that it can be evaluated exactly when the measured state is invariant under permutation or translation. In addition the detection of quantum phase transition is also discussed for Lipkin–Meshkov–Glick and Dicke model. Supported by National Natural Science Foundation of China under Grant No. 11005002 and 11475004, New Century Excellent Talent of M.O.E (NCET-11-0937), and Sponsoring Program of Excellent Younger Teachers in universities in Henan Province under Grant No. 2010GGJS-181

  7. Quantum Discord and Information Deficit in Spin Chains

    Directory of Open Access Journals (Sweden)

    Norma Canosa

    2015-03-01

    Full Text Available We examine the behavior of quantum correlations of spin pairs in a finite anisotropic XY spin chain immersed in a transverse magnetic field, through the analysis of the quantum discord and the conventional and quadratic one-way information deficits. We first provide a brief review of these measures, showing that the last ones can be obtained as particular cases of a generalized information deficit based on general entropic forms. All of these measures coincide with an entanglement entropy in the case of pure states, but can be non-zero in separable mixed states, vanishing just for classically correlated states. It is then shown that their behavior in the exact ground state of the chain exhibits similar features, deviating significantly from that of the pair entanglement below the critical field. In contrast with entanglement, they reach full range in this region, becoming independent of the pair separation and coupling range in the immediate vicinity of the factorizing field. It is also shown, however, that significant differences between the quantum discord and the information deficits arise in the local minimizing measurement that defines them. Both analytical and numerical results are provided.

  8. Parental Discord vs. Family Structure: Effects of Divorce on the Self-Esteem of Daughters.

    Science.gov (United States)

    Long, Barbara H.

    1986-01-01

    The effects of family structure and parental discord on the self-esteem of 199 female undergraduates were investigated. Family structure and happiness ratings were substantially related, with those separated rated as less happy. Parental discord appeared to lower the self-esteem of daughters, whereas separation of parents did not. (Author/LMO)

  9. Family Discord, Parental Depression, and Psychopathology in Offspring: 20-Year Follow-up

    Science.gov (United States)

    Pilowsky, Daniel J.; Wickramaratne, Priya; Nomura, Yoko; Weissman, Myrna M.

    2006-01-01

    Objective: To determine the independent effects of parental depression and family discord on offspring psychopathology among children at high and low risk of depression. Method: Family discord factors were assessed when subjects were approximately 17 years old, and offspring diagnoses were assessed about 20 years later. Parental and offspring…

  10. BMI, weight stability and mortality among adults without clinical co-morbidities: a 22-year mortality follow-up in the finnish twin cohort

    DEFF Research Database (Denmark)

    Korkeila, Maarit; Rissanen, Aila; Sørensen, Thorkild I A; Kaprio, Jaakko

    2009-01-01

    then followed over 22 years (1982-2003). Additionally, death discordant twin pairs were studied to assess whether body weight differences are associated with mortality independent of childhood factors and genetic background. Deaths and cause of death were ascertained from national registries......AIM AND METHOD: Cause-specific mortality was studied in relation to body mass index (BMI) and weight stability (defined as less than 1 BMI unit change during a 6-year period) in 15,424 initially healthy twin subjects from the Finnish Twin Cohort, first examined in 1975, re-examined in 1981, and....... Associations with mortality were estimated by Cox proportional hazards model for all individuals and conditional logistic regression analysis for pairwise analyses. RESULTS: Mortality increased with increasing BMI for all causes and coronary heart disease (CHD) in men, and there were no associations for all...

  11. Pediatric Residents' Perspective on Family-Clinician Discordance in Primary Care: A Qualitative Study.

    Science.gov (United States)

    Rosenthal, Marjorie S; Connor, Katherine A; Fenick, Ada M

    2016-01-01

    The engagement of families in health maintenance is associated with better child health outcomes, but demographic discordance between families and clinicians may be a barrier to family engagement. Using a longitudinal qualitative study design, we conducted 15 semi-structured interviews with five pediatric residents who elected to facilitate group well child care (GWCC). Four themes describing residents' perceptions of the role of discordance in family-clinician engagement include: 1) discordance was not a barrier; 2) discordance leads to a lack of engagement and trust; 3) residents transcended discordance in GWCC because either GWCC led residents to change their communication techniques or because, with GWCC, parents have concordant adults in the room; and 4) the education residents obtained in GWCC allowed them to empathize with the families' health-related decisions. Finding ways in which pediatric providers can improve skills in family engagement may be an important step in decreasing health inequities. PMID:27524749

  12. Cephalothoracoomphalopagus: a rare type of conjoined twin.

    Science.gov (United States)

    Koreti, Sunita; Prasad, Nitin; Patell, G Singh

    2014-01-01

    We present a case of female cephalothoracoomphalopagus conjoind twin, which is extremely rare type of conjoined twins. We also review the contemprory knowledge regarding incidence, etiopathogenesis, antenatal diagnosis and outcone or the prognosis of conjoint twins. The case belong to hindu female, no history of consanguineous marriage, ingestion of drugs or exposure to any radiation. History of one abortion and one twin delivery present. Conjoind twin was cephalothoracoomphalopagus type, delivered vaginaly at 30 wks of gestion to a 25 yrs old multigravida. Management of conjoind twin still remain challenges because of multiple congenital anomalies and poor outcome is seen. PMID:24741542

  13. The management of conjoined twins: Cardiology assessment.

    Science.gov (United States)

    Andrews, Rachel E; Yates, Robert W M; Sullivan, Ian D

    2015-10-01

    Structural cardiac defects occur in at least 1 twin in about 75% of conjoined twins with thoracic level fusion. Outcomes after surgical separation of thoracic level conjoined twins have been favorable when the hearts have been separate. However, even in this situation, the outlook is poor for an individual twin with an important cardiac defect. Arterial anastomosis between twin circulations is an important additional consideration, with poor outcomes for perfusion recipient twins. Surgical separation is contraindicated when ventricular level cardiac fusion exists. Cardiac assessment is a key component of prenatal counseling. PMID:26382259

  14. Successful Separation of Omphalopagus Twins: A Case Report

    OpenAIRE

    Patil, Prashant S.; Paras Kothari; Abhaya Gupta; Geeta Kekre; KV Dikshit; Ravi Kamble; Shahaji Deshmukh

    2016-01-01

    Omphalopagus twins are conjoined twins sharing part of gastrointestinal system and abdominal wall. These types of twins have best chances of survival if successfully separated. We report a case of successfully separated omphalopagus twins at day six of life.

  15. PolyCystic Ovary Syndrome in Monozygotic Twins Concordant for Lipid Profiles in Iranian Reproductive Women

    Directory of Open Access Journals (Sweden)

    Leila Amini

    2014-04-01

    Full Text Available Objective: There is evidence for genetics components in PCOS based on familial clustering of cases. We examined the contribution of genetics impact and some lipid/serum profiles to PCOS in a cohort study of Iranian twins. Materials and Methods: As a prominent predisposing risk factor for PCOS, serum lipid profiles (Triglyceride, Total cholesterol, HDL, LDL, Apo lipoprotein A–I, Apo lipoprotein B and lipoprotein A, were analyzed in 154 subjects of PCOS. The diagnosis of PCOS has been based on the Rotterdam consensus criteria in this study. We also studied 16 identical twin pairs discordant for PCOS to evaluate the effects of environmental risk factors (including lipid indices profiles for PCOS. Furthermore, we compared these 16 twin pairs with PCOS, in which just 15 (93.75% of them was concordant for abnormal lipid profiles. Also the impact of lipid profile in patients with PCOS was confirmed by comparing total 22 identical and non-identical twin pairs, in which 21 out of them (95.45% showed abnormal lipid profiles. Result: PCOS and increased cholesterol level were higher in identical versus non-identical twins with concordance rates of 1.5 and 1.65 (based on the Rotterdam consensus criteria, respectively. Analysis of identical pairs showed weak association between impact of lipid profile and PCOS while in non-identical pairs, the PCOS was associated with an increased environmental risk (lipid profile. Conclusion: Different lipid indices were affected by environmental and genetic risk factors in PCOS, but the contribution of environmental and genetic factors to the various PCOS-related changes in ovarian structures remains to be established.

  16. Twin-twin transfusion syndrome: neurodevelopmental screening test

    Directory of Open Access Journals (Sweden)

    Amabile Vessoni Arias

    2015-03-01

    Full Text Available Objective To assess the neurodevelopmental functions (cognition, language and motor function of survivors of twin-twin transfusion syndrome (TTTS. Method Observational cross-sectional study of a total of 67 monochorionic diamniotic twins who underwent fetoscopic laser coagulation (FLC for treatment of TTTS. The study was conducted at the Center for Investigation in Pediatrics (CIPED, Universidade Estadual de Campinas. Ages ranged from one month and four days to two years four months. Bayley Scales of Infant and Toddler Development Screening Test-III, were used for evaluation. Results Most children reached the competent category and were classified as having appropriate performance. The preterm children scored worse than term infants for gross motor subtest (p = 0.036. Conclusion The majority of children reached the expected development according to their age. Despite the good neurodevelopment, children classified at risk should be monitored for development throughout childhood.

  17. Influence of Genes and Environment on Brain Volumes in Twin Pairs Concordant and Discordant for Bipolar Disorder

    NARCIS (Netherlands)

    van der Schot, Astrid C.; Vonk, Ronald; Brans, Rachel G. H.; van Haren, Neeltje E. M.; Koolschijn, P. Cedric M. P.; Nuboer, Valerie; Schnack, Hugo G.; van Baal, G. Caroline M.; Boomsma, Dorret I.; Nolen, Willem A.; Pol, Hilleke E. Hulshoff; Kahn, Rene S.

    2009-01-01

    Context: Structural neuroimaging studies suggest the presence of subtle abnormalities in the brains of patients with bipolar disorder. The influence of genetic and/or environmental factors on these brain abnormalities is unknown. Objective: To investigate the contribution of genetic and environmenta

  18. Data in brief: Transcriptome analysis of induced pluripotent stem cells from monozygotic twins discordant for trisomy 21

    Directory of Open Access Journals (Sweden)

    Youssef Hibaoui

    2014-12-01

    Full Text Available Down syndrome (DS, trisomy 21, is the most common viable chromosomal disorder, with an incidence of 1 in 800 live births. Its phenotypic characteristics include intellectual impairment and several other developmental abnormalities, for the majority of which the pathogenetic mechanisms remain unknown. In this “Data in Brief” paper, we sum up the whole genome analysis by mRNA sequencing of normal and DS induced pluripotent stem cells that was recently published by Hibaoui et al. in EMBO molecular medicine.

  19. Association of COMT genotypes with S-COMT promoter methylation in growth-discordant monozygotic twins and healthy adults

    OpenAIRE

    Schreiner Felix; El-Maarri Osman; Gohlke Bettina; Stutte Sonja; Nuesgen Nicole; Mattheisen Manuel; Fimmers Rolf; Bartmann Peter; Oldenburg Johannes; Woelfle Joachim

    2011-01-01

    Abstract Background Catechol-O-Methyltransferase (COMT) plays a key role in dopamine and estrogen metabolism. Recently, COMT haplotypes rather than the single polymorphism Val158Met have been reported to underlie differences in protein expression by modulating mRNA secondary structure. So far, studies investigating the epigenetic variability of the S-COMT (soluble COMT) promoter region mainly focused on phenotypical aspects, and results have been controversial. Methods We assessed S-COMT prom...

  20. TwinMux Testing System

    CERN Document Server

    Wong, Wei Wen; CERN. Geneva. PH Department

    2015-01-01

    During the CERN summer school program, I joined the CMS Muon Drift Tube (DT) group, and mainly worked on two projects, which, both of them, are related to the electronics of a new data concentrator called the “TwinMux”. My first task within the TwinMux project was to build an integrated software test station in order to run several tests on the functionality of the TwinMux hardware. Essentially, I had to integrate existing testing scripts, adding several new ones, into a single user-friendly testing platform which can perform quick, convenient and automated hardware testing. Later, I was also involved in the design of the local technical triggering of the DT. Such system relies on some firmware functionality built in the TwinMux and controlled by software. I had attempted two different approaches to design the communication topology of all the 12 TwinMux cards in order to send a user-defined logical operation to the read-out electronics. The final goal of this system is to drive local trigger signal for...

  1. Characterizing Blood Metabolomics Profiles Associated with Self-Reported Food Intakes in Female Twins.

    Directory of Open Access Journals (Sweden)

    Tess Pallister

    Full Text Available Using dietary biomarkers in nutritional epidemiological studies may better capture exposure and improve the level at which diet-disease associations can be established and explored. Here, we aimed to identify and evaluate reproducibility of novel biomarkers of reported habitual food intake using targeted and non-targeted metabolomic blood profiling in a large twin cohort. Reported intakes of 71 food groups, determined by FFQ, were assessed against 601 fasting blood metabolites in over 3500 adult female twins from the TwinsUK cohort. For each metabolite, linear regression analysis was undertaken in the discovery group (excluding MZ twin pairs discordant [≥1 SD apart] for food group intake with each food group as a predictor adjusting for age, batch effects, BMI, family relatedness and multiple testing (1.17x10-6 = 0.05/[71 food groups x 601 detected metabolites]. Significant results were then replicated (non-targeted: P<0.05; targeted: same direction in the MZ discordant twin group and results from both analyses meta-analyzed. We identified and replicated 180 significant associations with 39 food groups (P<1.17x10-6, overall consisting of 106 different metabolites (74 known and 32 unknown, including 73 novel associations. In particular we identified trans-4-hydroxyproline as a potential marker of red meat intake (0.075[0.009]; P = 1.08x10-17, ergothioneine as a marker of mushroom consumption (0.181[0.019]; P = 5.93x10-22, and three potential markers of fruit consumption (top association: apple and pears: including metabolites derived from gut bacterial transformation of phenolic compounds, 3-phenylpropionate (0.024[0.004]; P = 1.24x10-8 and indolepropionate (0.026[0.004]; P = 2.39x10-9, and threitol (0.033[0.003]; P = 1.69x10-21. With the largest nutritional metabolomics dataset to date, we have identified 73 novel candidate biomarkers of food intake for potential use in nutritional epidemiological studies. We compiled our findings into the

  2. Conservation law for distributed entanglement of formation and quantum discord

    International Nuclear Information System (INIS)

    We present a direct relation, based upon a monogamic principle, between entanglement of formation (EOF) and quantum discord (QD), showing how they are distributed in an arbitrary tripartite pure system. By extending it to a paradigmatic situation of a bipartite system coupled to an environment, we demonstrate that the EOF and the QD obey conservation relation. By means of this relation we show that in the deterministic quantum computer with one pure qubit the protocol has the ability to rearrange the EOF and the QD, which implies that quantum computation can be understood on a different basis as a coherent dynamics where quantum correlations are distributed between the qubits of the computer. Furthermore, for a tripartite mixed state we show that the balance between distributed EOF and QD results in a stronger version of the strong subadditivity of entropy.

  3. Geometric quantum discord and non-Markovianity of structured reservoirs

    Science.gov (United States)

    Hu, Ming-Liang; Lian, Han-Li

    2015-11-01

    The reservoir memory effects can lead to information backflow and recurrence of the previously lost quantum correlations. We establish connections between the direction of information flow and variation of the geometric quantum discords (GQDs) measured respectively by the trace distance, the Hellinger distance, and the Bures distance for two qubits subjecting to the bosonic structured reservoirs, and unveil their dependence on a factor whose derivative signifies the (non-)Markovianity of the dynamics. By considering the reservoirs with Lorentzian and Ohmic-like spectra, we further demonstrated that the non-Markovianity induced by the backflow of information from the reservoirs to the system enhances the GQDs in most of the parameter regions. This highlights the potential of non-Markovianity as a resource for protecting the GQDs.

  4. Quantum discord and other measures of quantum correlation

    CERN Document Server

    Modi, Kavan; Cable, Hugo; Paterek, Tomasz; Vedral, Vlatko

    2011-01-01

    One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of the correlations are amongst the most actively-studied topics of quantum information theory in the past decade. Entanglement is the most prominent of these correlations, but in many cases unentangled states exhibit nonclassical behavior. Thus distinguishing quantum correlation other than entanglement provides a better division between the quantum and classical worlds, especially when considering mixed states. Here we review different notions of classical and quantum correlations quantified by quantum discord and other related measures. In the first half we review the mathematical properties of the measures of quantum correlation, relate them to each other, and discuss the classical-quantum division that is common among them. In the second half, we show that the measures quantum correlation identify and quanti...

  5. Complications arising in twin pregnancy: findings of prenatal ultrasonography

    International Nuclear Information System (INIS)

    Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios- polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications

  6. Complications Arising in Twin Pregnancy: Findings of Prenatal Ultrasonography

    OpenAIRE

    Kim, Jeong-Ah; Cho, Jeong Yeon; Lee, Young Ho; Song, Mi Jin; Min, Jee-Yeon; Lee, Hak Jong; Han, Byoung Hee; Lee, Kyung-Sang; Cho, Byung Jae; Chun, Yi-Kyeong

    2003-01-01

    Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios-polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications.

  7. Complications arising in twin pregnancy: findings of prenatal ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Ah; Cho, Jeong Yeon; Lee, Young Ho; Song, Mi Jin; Min, Jee Yeon; Lee, Hak Jong; Han, Byoung Hee; Lee, Kyung Sang; Cho, Byung Jae; Chun, Yi Kyeong [Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2003-03-01

    Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios- polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications.

  8. Risk of Oral Clefts in Twins

    DEFF Research Database (Denmark)

    Grosen, Dorthe; Bille, Camilla; Petersen, Inge;

    2011-01-01

    ratio for twins versus singletons, stratified for 3 subphenotypes. Probandwise concordance rates and heritability for twins were estimated for 2 phenotypes-cleft lip with or without cleft palate (CL/P) and cleft palate (CP). RESULTS:: The prevalence of oral cleft was 15.8 per 10,000 twins and 16.6 per......BACKGROUND:: Small studies have indicated that twinning increases the risk of oral cleft. METHODS:: We used data from a Danish national population-based cohort study to investigate whether twinning was associated with isolated oral cleft, and to estimate the twin probandwise concordance rate and...... heritability. Twins (207 affected/130,710) and singletons (7766 affected/4,798,526) born from 1936 through 2004 in Denmark were ascertained by linkage among the Danish Facial Cleft Database, the Danish Twin Registry, and the Civil Registration System. We computed oral cleft prevalence and prevalence proportion...

  9. Congenital diaphragmatic hernia in identical twins

    OpenAIRE

    Gurbaz, Mustafa T.; Ahmet Kazez; Unal Bakal; Tugay Tartar; Fikret Ersoz; Yunus Colakoglu

    2012-01-01

    Congenital diaphragmatic hernia (CDH, Bochdalek type) is rarely seen in both members of identical twins. Herein, we report a 37 weeks′ twins with CDH along with a brief review of the literature. Both the neonates survived.

  10. Congenital diaphragmatic hernia in identical twins

    Directory of Open Access Journals (Sweden)

    Mustafa T Gurbaz

    2012-01-01

    Full Text Available Congenital diaphragmatic hernia (CDH, Bochdalek type is rarely seen in both members of identical twins. Herein, we report a 37 weeks′ twins with CDH along with a brief review of the literature. Both the neonates survived.

  11. Having Twins? How to Stay Healthy

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Having Twins? How to Stay Healthy Page Content Article Body ... the eyes of obstetricians. Many would call a twin pregnancy a high-risk pregnancy , but don’t ...

  12. Nike Twins Seven Seven: Nigerian Batik Artist.

    Science.gov (United States)

    LaDuke, Betty

    1987-01-01

    Chronicles the personal and professional life of Nike Twins Seven Seven (born 1951), a Nigerian batik artist, and her husband, Twins Seven Seven, a musician-artist, both of whom have received international acclaim. (BJV)

  13. The Syntactic Abilities of Identical Twins, Fraternal Twins, and Their Siblings

    Science.gov (United States)

    Munsinger, Harry; Douglass, Arthur, II

    1976-01-01

    The language development of monozygotic twins, same-sex dizygotic twins, siblings of monozygotic twins, and siblings of dizygotic twins, ages 3-17, was studied to estimate how much of the individual variation in children's language skills results from genetic factors and how much from environmental experience. (BRT)

  14. Causes and consequences of obesity: the contribution of recent twin studies.

    Science.gov (United States)

    Naukkarinen, J; Rissanen, A; Kaprio, J; Pietiläinen, K H

    2012-08-01

    Obesity is a genetically complex disorder that produces a myriad of health problems. Most of the recognized complications of obesity are not only strongly influenced by lifestyle factors, but also present with independent genetic predispositions that are notoriously difficult to disentangle in humans. Most studies on the causes and consequences of acquired obesity are encumbered by the incomplete ability to control for genetic influences. However, utilizing a unique experiment of nature, namely monozygotic twins (MZ) discordant for obesity as 'clonal controls' of obese and non-obese individuals has enabled the fine characterization of the effects and possible antecedents of acquired obesity while controlling for the genetic background, as well as pointed to novel obesity predisposing candidate genes. This review is a distillation of the findings from more than 10 years of research done in an exceptionally well-characterized collection of MZ and dizygotic (DZ) twins, based on the Finnish Twin Cohorts. Topics covered include the nature of development of obesity from the childhood onwards, the role of exercise in modifying the genetic susceptibility, the resulting inflammatory, prediabetic and preatherosclerotic changes in whole body and adipose tissue physiology, as well as the newest insights provided by the omics revolution. PMID:21986704

  15. Twin TQFTs and Frobenius Algebras

    Directory of Open Access Journals (Sweden)

    Carmen Caprau

    2013-01-01

    Full Text Available We introduce the category of singular 2-dimensional cobordisms and show that it admits a completely algebraic description as the free symmetric monoidal category on a twin Frobenius algebra, by providing a description of this category in terms of generators and relations. A twin Frobenius algebra (C,W,z,z∗ consists of a commutative Frobenius algebra C, a symmetric Frobenius algebra W, and an algebra homomorphism z:C→W with dual z∗:W→C, satisfying some extra conditions. We also introduce a generalized 2-dimensional Topological Quantum Field Theory defined on singular 2-dimensional cobordisms and show that it is equivalent to a twin Frobenius algebra in a symmetric monoidal category.

  16. Intensive care of conjoined twins.

    Science.gov (United States)

    Kobylarz, Krzysztof

    2014-01-01

    Conjoined twinning is one of the most uncommon congenital anomalies. Maintenance in an intensive care setting during this time allows for close monitoring, stabilisation, and nutritional supplementation of the infants as necessary to optimise preoperative growth and development. The birth of conjoined twins is a very difficult and dramatic moment for parents. It is also a very difficult situation for the team of physicians, nurses and other required hospital staff to carry out treatment and care of these specific developmental anomalies. The diagnostics and treatment in this extraordinary situation requires close cooperation of the multidisciplinary medical team, which includes their personal experience and medical knowledge, with a team of intensive care unit nurses. This report presents the rules in cease of conjoined twins during their intensive care unit stay with special reference to the proceedings before and after complete separation. PMID:24858974

  17. Thoracopagus Conjoined Twins: A Case Report

    OpenAIRE

    Özgür Özdemir; Cavit Kart; Süleyman Güven; Turhan Aran; Mehmet A. Osmanağaoğlu; Hasan Bozkaya

    2011-01-01

    Objective. Conjoined twin is a rarely seen congenital anomaly together with severe mortality and morbidity. The more common types of conjoined twins include the thoracopagus type, where the fusion is anterior, at the chest, and involves the heart. We are reporting one case of conjoined thoracopagus twins diagnosed by ultrasonography at 11 weeks. Case Report. In a multigravid pregnant woman who has been admitted to our clinic with a diagnosis of conjoined twins, thoracopagus, by ultrasonograph...

  18. The application of angiography in conjoined twins

    International Nuclear Information System (INIS)

    Objective: To report a case of conjoined twins with peripheral angiography together with cardioangiographic technique. Methods: Left ventriculogram, right ventriculogram, descending aortogram and selected celiac arteriogram were separately performed for both babies of the conjoined twin. Results: Angiocardiography showed the anatomy of cardiac and abdominal vessels of the thoraco-omphalopagus conjoined twin clearly and confirmed by the separation operation. Conclusions: The angiographic examination is difficult but very helpful for successful operation of the conjoined twin. (authors)

  19. The Study of Diagnostic Results Discordance Analysis on BMD Using DEXA

    International Nuclear Information System (INIS)

    This study was conducted to understand for the diagnostic discordance of bone mineral density(BMD) in DEXA(Dual Energy X-ray Absorptiometry). And the diagnostic difference between lumbar spine and femur neck, forearm was evaluated using T-score. We studied 220 females measured BMD on lumbar spine, and femur neck, forearm including ward's triangle and ultra digital(UD). We were distinguished T-score into normal, osteopenia, osteoporosis(WHO classification) and evaluated discordance rate according to age and degree of bone loss. Correlation analysis and chi-square test between L-spine, L-4, femur neck, Ward, Forearm, UD were carried out. In the lumbar spine, the number of normal were in 57(25.9%), osteopenia in 86(39.1%), osteoporosis in 77(35.0%). In the L-4 and ward's triangle, the number of osteoporosis were in 78(35.5%), in 126(57.3%). There was significant correlation between lumbar, femur neck and forearm BMD in all cases. The discordance of BMD between lumbar and femur were 57%, lumbar and forearm 43%, forearm and femur 51%. The discordance rates of normal, osteopenic, osteoporotic groups were 39%, 64%, 43%, respectively, showing the highest discordance rate in osteopenia patients. In normal group of lumbar spine, the discordance rate was 25%, 23%, 11%, 65%, 86% in 30', 40', 50', 60', 70', respectively. In osteopenia, osteoporosis group of lumbar spine, the discordance rate was 62%, 55%, 36%, 20%, 9% in 30', 40', 50', 60', 70', respectively. It was different of the results of BMD with lumbar, femur and forearm site. The discordance rate was decreased with age in osteopenia, osteoporosis lumbar spine. In osteopenia group, the discordance rate was the highest. So, it is necessary that the BMD of lumbar, femur neck and forearm should be checked.

  20. [Pygopagus Siamese twins. Surgical treatment].

    Science.gov (United States)

    Rollán Villamarín, V; Ollero Fresno, J C; Alonso Calderón, J L; Ollero Caprani, J M

    1991-04-01

    A case is presented wherein a set of black female pygopagus siamese twins were successfully separated by our department in their 45th day of life. Both twins had multiple malformations: cardiopulmonary, vertebral, anorectal, genitourinary, etc. The bilateral renal absence in one of them, originated her death on the 7th postoperative day. Only nine other cases have been referred successful during the last 35 years, in a bibliographic review conducted. The associated malformations and surgical skills for treatment and separation of them, are studied: previous colostomy and effective separation at life ages, comprised between one and thirteen months. PMID:2064894

  1. A study of malocclusion in identical twins

    Directory of Open Access Journals (Sweden)

    E. Akhavan Niaki

    1998-04-01

    Full Text Available   Monozygotic twins are genetically identical individuals who can also be mirror image twins and the Differences between them result from environmental factors. current study, monozygotic twins were analyzed in different dentitions of primary, mixed and permanent. As a conclusion, although genetic factors are naturally potent, environmental factors’ role can be increased and weaken the genetic factors.

  2. Speech and Language Delays in Identical Twins.

    Science.gov (United States)

    Bentley, Pat

    Following a literature review on speech and language development of twins, case studies are presented of six sets of identical twins screened for entrance into kindergarten. Five sets of the twins and one boy from the sixth set failed to pass the screening test, particularly the speech and language section, and were referred for therapy to correct…

  3. A study of malocclusion in identical twins

    OpenAIRE

    E. Akhavan niaki

    1998-01-01

      Monozygotic twins are genetically identical individuals who can also be mirror image twins and the Differences between them result from environmental factors. current study, monozygotic twins were analyzed in different dentitions of primary, mixed and permanent. As a conclusion, although genetic factors are naturally potent, environmental factors’ role can be increased and weaken the genetic factors.

  4. Concordance for multiple sclerosis in Danish twins

    DEFF Research Database (Denmark)

    Hansen, T; Skytthe, Axel; Stenager, Egon;

    2005-01-01

    The occurrence of multiple sclerosis (MS) in twins has not previously been studied in complete nationwide data sets. The existence of almost complete MS and twin registries in Denmark ensures that essentially unbiased samples of MS cases among twins can be obtained. In this population-based study...

  5. Cesarean section for the second twin

    DEFF Research Database (Denmark)

    Engelbrechtsen, Line; Nielsen, Elise Hoffmann; Perin, Trine;

    2013-01-01

    BACKGROUND: Although management of twin deliveries has been a topic of discussion for decades, a consensus on how to deliver twins is lacking. The objective of this study was to examine short-term neonatal outcome of the second twin delivered by cesarean section after vaginal delivery of the firs...

  6. The 'Planemo' Twins

    Science.gov (United States)

    2006-08-01

    The cast of exoplanets has an extraordinary new member. Using ESO's telescopes, astronomers have discovered an approximately seven-Jupiter-mass companion to an object that is itself only twice as hefty. Both objects have masses similar to those of extra-solar giant planets, but they are not in orbit around a star - instead they appear to circle each other. The existence of such a double system puts strong constraints on formation theories of free-floating planetary mass objects. ESO PR Photo 29a/06 ESO PR Photo 29a/06 Double System of Planetary Mass Objects (Artist's View) Ray Jayawardhana of the University of Toronto (Canada) and Valentin D. Ivanov of ESO report the discovery in the August 3 issue of Science Express, the rapid online publication service of the journal Science. "This is a truly remarkable pair of twins - each having only about one percent the mass of our Sun," said Jayawardhana. "Its mere existence is a surprise, and its origin and fate a bit of a mystery." Roughly half of all Sun-like stars come in pairs. So do about a sixth of brown dwarfs, 'failed stars' that have less than 75 Jupiter masses and are unable to sustain nuclear fusion in their cores. During the past five years, astronomers have identified a few dozen of even smaller free-floating planetary mass objects, or planemos, in nearby star forming regions. Oph 162225-240515, or Oph1622 for short, is the first planemo found to be a double. The researchers discovered the companion candidate in an optical image taken with ESO's 3.5-m New Technology Telescope at La Silla, Chile. They decided to take optical spectra and infrared images of the pair with ESO's 8.2-m Very Large Telescope to make sure that it is a true companion, instead of a foreground or background star that happens to be in the same line of sight. These follow up observations indeed confirmed that both objects are young, at the same distance, and much too cool to be stars. This suggests the two are physically associated. ESO PR

  7. Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    International Nuclear Information System (INIS)

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival. (note)

  8. Increasing cardiac output and decreasing oxygenation sequence in pump twins of acardiac twin pregnancies

    Energy Technology Data Exchange (ETDEWEB)

    Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); VanBavel, Ed [Department of Medical Physics, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Vandenbussche, Frank P H A [Department of Obstetrics, Leiden University Medical Center, Leiden (Netherlands); Nikkels, Peter G J [Department of Pathology, University Medical Center, Utrecht (Netherlands)

    2005-02-07

    An acardiac twin pregnancy is a rare but serious complication of monochorionic twinning and consists of an acardiac twin and a pump twin. The acardiac twin is a severely malformed fetus that lacks most organs, particularly a heart, but grows during pregnancy because it is perfused by the developmentally normal pump twin via a set of arterioarterial and venovenous placental anastomoses. Pump twins die intrauterine or neonatally in about 50% of the cases. Because the effects of an acardiac mass on the pump twin's development are incompletely known, methods for outcome prognosis are currently not available. We sought to derive simple relations for the pump twin's excess cardiac output and decreased oxygenation and to use available clinical cases for a preliminary test of the model. As a method, we used a theoretical flow model to represent the fetoplacental circulation of an acardiac twin pregnancy and estimated blood deoxygenation and reoxygenation following perfusion of the two bodies and placentas, respectively. The results show the pump twin's excess cardiac output and decrease of venous oxygen saturation to depend on the ratio of pump twin to acardiac twin umbilical blood flow, whose ratio can be measured by ultrasonography. The clinical cases show a decreasing umbilical flow ratio with gestation. In conclusion, prospective serial study is necessary to test whether measurement of umbilical flow ratios allows monitoring the pump twin's pathophysiologic development, possibly resulting in a guideline for prognosis of pump twin survival. (note)

  9. Generalised Anxiety Disorder--A Twin Study of Genetic Architecture, Genome-Wide Association and Differential Gene Expression.

    Directory of Open Access Journals (Sweden)

    Matthew N Davies

    Full Text Available Generalised Anxiety Disorder (GAD is a common anxiety-related diagnosis, affecting approximately 5% of the adult population. One characteristic of GAD is a high degree of anxiety sensitivity (AS, a personality trait which describes the fear of arousal-related sensations. Here we present a genome-wide association study of AS using a cohort of 730 MZ and DZ female twins. The GWAS showed a significant association for a variant within the RBFOX1 gene. A heritability analysis of the same cohort also confirmed a significant genetic component with h2 of 0.42. Additionally, a subset of the cohort (25 MZ twins discordant for AS was studied for evidence of differential expression using RNA-seq data. Significant differential expression of two exons with the ITM2B gene within the discordant MZ subset was observed, a finding that was replicated in an independent cohort. While previous research has shown that anxiety has a high comorbidity with a variety of psychiatric and neurodegenerative disorders, our analysis suggests a novel etiology specific to AS.

  10. Playing a Musical Instrument as a Protective Factor against Dementia and Cognitive Impairment: A Population-Based Twin Study

    Directory of Open Access Journals (Sweden)

    M. Alison Balbag

    2014-01-01

    Full Text Available Increasing evidence supports that playing a musical instrument may benefit cognitive development and health at young ages. Whether playing an instrument provides protection against dementia has not been established. In a population-based cotwin control study, we examined the association between playing a musical instrument and whether or not the twins developed dementia or cognitive impairment. Participation in playing an instrument was taken from informant-based reports of twins’ leisure activities. Dementia diagnoses were based on a complete clinical workup using standard diagnostic criteria. Among 157 twin pairs discordant for dementia and cognitive impairment, 27 pairs were discordant for playing an instrument. Controlling for sex, education, and physical activity, playing a musical instrument was significantly associated with less likelihood of dementia and cognitive impairment (odds ratio [OR] = 0.36 [95% confidence interval 0.13–0.99]. These findings support further consideration of music as a modifiable protective factor against dementia and cognitive impairment.

  11. [Separation of pygopagous Siamese twins].

    Science.gov (United States)

    Gille, P; Aubert, D; Mourot, M; François, J Y; Nachin, P; Delafin, J; Bonneville, J F; Cordier, A; Rousseaux, D; Monnier, G

    1983-01-01

    The successful separation of pygopagous twins is described. The sacrum formed a common canal since S 1 to coccyx with two medullary cords side to side and diastematomyelia with, at this level, two dural sacks. In each baby there was small atrophy in one lower limb. There were two opposite vulvovaginal ducts and two recto-perineal fistules. PMID:6850958

  12. Identical twins with Alzheimer's disease.

    OpenAIRE

    Kilpatrick, C; Burns, R; Blumbergs, P C

    1983-01-01

    Genetically proven identical twin sisters with Alzheimer's disease are reported. Both sisters at the age of fifty years developed a dementing illness. Their mother and maternal grandmother developed at the same age a similar illness. It is suggested that in some cases of familial Alzheimer's disease the condition is inherited by a single mutant gene.

  13. Register-based research on twins

    DEFF Research Database (Denmark)

    Christensen, Kaare; Ohm Kyvik, Kirsten; Holm, Niels V;

    2011-01-01

    Introduction: The Danish Twin Registry (DTR) has for more than 50 years been based on surveys and clinical investigations and over the two last decades also on register linkage. Currently these two approaches are merged within Statistics Denmark. Research topics: Here we report on three major...... groups of register-based research in the DTR that used the uniqueness of twinning. First, we focus on the ''long-term prognosis'' of being a twin compared with being a singleton and show that Danish twins have health trajectories in adulthood similar to singletons, which is a result of interest for twins...

  14. Returns to Education: Evidence from UK Twins

    OpenAIRE

    Bonjour, Dorothe; Cherkas, Lynn; Haskel, Jonathan; Spector, Tim

    2002-01-01

    We use a new sample of UK female identical twins to estimate private economic returns to education. We report findings in three areas. First, we use identical twins, to control for family effects and genetic ability bias, and the education reported by the other twin to control for schooling measurement error. Our estimates suggest a return to schooling for UK females of about 7.7%. Second, we investigate within-twin pair ability differences by examining within-twin pair and between-family cor...

  15. Returns to education: evidence from UK twins

    OpenAIRE

    Bonjour, Dorothe; Cherkas, Lyn; Haskel, Jonathan; Hawkes, Denise; Spector, Tim

    2002-01-01

    We use a new sample of UK female identical twins to estimate private economic returns to education. We report findings in three areas. First, we use identical twins, to control for family effects and genetic ability bias, and the education reported by the other twin to control for schooling measurement error. Our estimates suggest a return to schooling for UK females of about 7.7%. Second, we investigate within-twin pair ability differences by examining within-twin pair and between-family cor...

  16. The relation between the quantum discord and quantum teleportation: The physical interpretation of the transition point between different quantum discord decay regimes

    Science.gov (United States)

    Roszak, K.; Cywiński, Ł.

    2015-10-01

    We study quantum teleportation via Bell-diagonal mixed states of two qubits in the context of the intrinsic properties of the quantum discord. We show that when the quantum-correlated state of the two qubits is used for quantum teleportation, the character of the teleportation efficiency changes substantially depending on the Bell-diagonal-state parameters, which can be seen when the worst-case-scenario or best-case-scenario fidelity is studied. Depending on the parameter range, one of two types of single-qubit states is hardest/easiest to teleport. The transition between these two parameter ranges coincides exactly with the transition between the range of classical correlation decay and quantum correlation decay characteristic for the evolution of the quantum discord. The correspondence provides a physical interpretation for the prominent feature of the decay of the quantum discord.

  17. A note on one-way quantum deficit and quantum discord

    Science.gov (United States)

    Ye, Biao-Liang; Fei, Shao-Ming

    2016-01-01

    One-way quantum deficit and quantum discord are two important measures of quantum correlations. We revisit the relationship between them in two-qubit systems. We investigate the conditions that both one-way quantum deficit and quantum discord have the same optimal measurement ensembles, and demonstrate that one-way quantum deficit can be derived from the quantum discord for a class of X states. Moreover, we give an explicit relation between one-way quantum deficit and entanglement of formation. We show that under phase damping channel both one-way quantum deficit and quantum discord evolve exactly in the same way for four parameter X states. Some examples are presented in details.

  18. Geometric measure of quantum discord for entanglement of Dirac fields in noninertial frames

    International Nuclear Information System (INIS)

    We investigate the geometric measure of quantum discord of all possible bipartite divisions of a tripartite system of Dirac fields in noninertial frames. As a comparison, we calculate the geometric measure of entanglement. We discuss the properties of geometric measure of quantum discord and geometric measure of entanglement for three qubit–qubit subsystems with acceleration parameter and the parameter describing the degree of entanglement the system in detail. We have found a conservative relationship involving two of three geometric discords in some condition and another conservative relationship involving three geometric discords for initially maximally entangled states. By the way, we also report some conservative relationships of concurrence, mutual information and geometric measure of entanglement for two bipartite subsystems

  19. Geometric measure of quantum discord for entanglement of Dirac fields in noninertial frames

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, Wen-Chao, E-mail: qwcqj@163.com [Faculty of Science, Xi' an University of Architecture and Technology, Xi' an, 710055 (China); Zhang, Lei [Huaqing College, Xi' an University of Architecture and Technology, Xi' an, 710055 (China)

    2015-03-06

    We investigate the geometric measure of quantum discord of all possible bipartite divisions of a tripartite system of Dirac fields in noninertial frames. As a comparison, we calculate the geometric measure of entanglement. We discuss the properties of geometric measure of quantum discord and geometric measure of entanglement for three qubit–qubit subsystems with acceleration parameter and the parameter describing the degree of entanglement the system in detail. We have found a conservative relationship involving two of three geometric discords in some condition and another conservative relationship involving three geometric discords for initially maximally entangled states. By the way, we also report some conservative relationships of concurrence, mutual information and geometric measure of entanglement for two bipartite subsystems.

  20. Breast lesions with discordant results on ultrasound-guided core needle biopsy

    International Nuclear Information System (INIS)

    We wanted to evaluate the characteristics of those lesions showing insufficient results on ultrasound-guided core needle biopsy. We retrospectively reviewed the pathologic results of 131 lesions from patients who underwent ultrasound-guided core needle biopsy following Mammotome or surgical excisional biopsy from January 2004 to December 2004. Compared with excisional biopsy, ultrasound-guided core needle biopsy showed 14 lesions with discordant results and 9 lesions with indeterminate results. 5 lesions were overestimated and 9 lesions were underestimated on the core needle biopsies. According to the histological tumor types, the papillary tumors showed 66.6% discordance or indetermination, and the phyllodes tumors showed 50% discordance or indetermination. On the results of core needle biopsy, discordant or indeterminate results were frequently reported for papillary and phyllodes tumor. Therefore, excisional biopsy is recommended for these types of tumor

  1. Deformation twinning in explosively-driven tantalum

    International Nuclear Information System (INIS)

    Deformation twinning resulting from high explosive-driven shock and associated plasticity was investigated in high-purity b.c.c. tantalum. Post mortem characterization of samples shocked at relatively higher and lower pressures showed significant {112}〈111〉 twin activity. Further analysis of the lower shock pressure sample showed twins to be spatially clustered at the mesoscale, indicating the role of twin termination at grain boundaries to produce requisite twin initiation stresses in neighbor grains. In addition, analysis of electron backscatter diffraction data suggests that twin propagation across boundaries does not require minimal misorientations between the active variants of the twins in adjacent parent grains. A minimum threshold grain size of approximately 25 μm was determined for both samples, below which twinning was suppressed. Finally, the observation of spall voids at twin intersections implied that twinning increases the density of preferred damage initiation sites during the shock deformation process. Overall, twinning was shown to play a significant role in the deformation and damage evolution of shock-loaded tantalum.

  2. A Twin Study of Perthes Disease

    DEFF Research Database (Denmark)

    Metcalfe, David; Van Dijck, Stephanie; Parsons, Nicolas; Christensen, Kaare; Perry, Daniel C

    2016-01-01

    genetic associations with LCPD. METHODS: We extracted all twin pairs from the Danish Twin Registry (DTR) in which at least 1 individual had LCPD. The DTR captures every twin pair born alive in Denmark, and those with LCPD were identified by using health record linkage. Probanwise concordance was...... calculated to describe the likelihood that any given individual had LCPD if their co-twin was also diagnosed. RESULTS: There were 81 twin pairs: 10 monozygotic, 51 dizygotic, and 20 unclassified (unknown zygosity [UZ]). There was no association between birth weight and being the affected co-twin. Four pairs...... (2 dizygotic and 2 UZ) were concordant for LCPD, which is greater than would be expected assuming no familial aggregation. There were no concordant monozygotic twin pairs. The overall probandwise concordance was 0.09 (95% confidence interval [CI]: 0.01-0.18): 0.00 for the monozygotic, 0.08 (95% CI: 0...

  3. Imaging concerns unique to twin pregnancy.

    Science.gov (United States)

    Mahalingam, Sowmya; Dighe, Manjiri

    2014-01-01

    The incidence of multiple gestations is increasing with rising maternal age and the utilization of artificial reproductive techniques. Twinning confers an increased risk to the pregnancy, with higher incidence of structural anomalies, preterm delivery, and perinatal morbidity and mortality. Certain conditions are unique to twin pregnancy, such as the twin-to-twin transfusion syndrome and the acardiac twin, secondary to vascular sharing between both the fetuses. Conjoined twinning is a phenomenon occurring because of late splitting of the zygote. Advances in imaging have increased our ability to manage multiple pregnancies with accurate prenatal diagnosis, better antenatal surveillance, and novel image-guided procedures. The purpose of this article is to provide an overview of the twinning process, including the pathophysiology, diagnostic pearls, and dilemmas and to briefly outline the outcomes and available treatment options to assist the radiologist in better management of multiple gestations. PMID:25239076

  4. TRAP Sequence - An Interesting Entity in Twins

    Directory of Open Access Journals (Sweden)

    R H Srinivas Prasad

    2012-01-01

    Full Text Available Twin reversed arterial perfusion (TRAP sequence, is a rare malformation occurring in monozygotic multiple gestations. One well-developed normal (pump twin and the other twin with absent cardiac structure (acardiac, who is hemodynamically dependent on the normal (pump twin are characteristic of this syndrome. The acardiac twin develops multiple anomalies that make survival difficult. The prognosis of the pump twin is variable with mortality rate ranging from 50% to 70%. Complications that affect the prognosis of the pump twin include complications of congestive cardiac failure due to increased cardiac demand, prematurity secondary to preterm delivery, and polyhydramnios. Because of these complications prompt detection, follow-up, and treatment of this condition is very important. We report two cases of TRAP sequence that emphasizes the importance of gray-scale and color Doppler imaging in diagnosis, detection of poor prognostic features, follow-up, and management of TRAP sequence.

  5. Quantum Discord and Entanglement in Quasi-Werner States Based on Bipartite Superposed Coherent States

    CERN Document Server

    Maurya, Ajay K; Prakash, Hari

    2012-01-01

    Recently, the authors [arXiv quant-ph 1209.3706] studied quantum discord for Werner mixed states based on the four entangled coherent states, which are used for quantum teleportation of single qubit information encoded in superposed coherent state and compared it with entanglement of formation. In the present paper, we consider two more general bipartite superposed coherent states and get two quasi-Werner states. We study quantum discord and entanglement of formation for these states and compare them.

  6. Family discord is associated with increased substance use for pregnant substance users

    OpenAIRE

    Denton, Wayne H.; Adinoff, Bryon H.; Lewis, Daniel; Walker, Robrina; Winhusen, Theresa

    2013-01-01

    Childhood abuse and partner violence are associated with prenatal substance abuse but the potential impact of current family discord, which reflects broader family relationships and encompasses problems less severe than violence, has had little evaluation in pregnant substance users. Using data from 196 pregnant substance users participating in a NIDA Clinical Trials Network randomized clinical trial, we examined the relationship of baseline family discord to substance use a...

  7. Hierarchy of efficiently computable and faithful lower bounds to quantum discord

    OpenAIRE

    Piani, Marco

    2015-01-01

    Quantum discord expresses a fundamental non-classicality of correlations more general than quantum entanglement. We combine the no-local-broadcasting theorem, semidefinite-programming characterizations of quantum fidelity and quantum separability, and a recent breakthrough result of Fawzi and Renner about quantum Markov chains to provide a hierarchy of computationally efficient lower bounds to quantum discord. Such a hierarchy converges to the surprisal of measurement recoverability introduce...

  8. Characterization of Sera with Discordant Results from Reverse Sequence Screening for Syphilis

    OpenAIRE

    Kyunghoon Lee; Hyewon Park; Eun Youn Roh; Sue Shin; Kyoung Un Park; Myoung Hee Park; Eun Young Song

    2013-01-01

    Reverse sequence screening for syphilis (RSSS) (screening with treponemal tests, followed by confirmation with nontreponemal tests) has been increasingly adopted. CDC recommends confirmation of discordant results (reactive EIA/CIA and nonreactive nontreponemal test) with Treponema pallidum particle agglutination assay (TP-PA). We characterized sera with discordant results from RSSS with Architect Syphilis TP CIA. Among 15,713 screening tests using Architect Syphilis TP at Seoul National Unive...

  9. Maintaining tricuspid valve competence in double discordance: a challenge for the paediatric cardiologist

    OpenAIRE

    Acar, P; Sidi, D; Bonnet, D.; Aggoun, Y; Bonhoeffer, P; Kachaner, J

    1998-01-01

    Objectives—To establish the prevalence of tricuspid valve abnormalities in children with a double discordant heart (or congenitally corrected transposition of the great arteries); to study the influence of the loading conditions induced by various surgical interventions on the right and left ventricle in patients with double discordance and an abnormal tricuspid valve; and to propose a rational surgical approach.
Methods—Case notes were reviewed of 141 consecutive patients admitted in the fir...

  10. Peer Review of Grant Applications: A Simple Method to Identify Proposals with Discordant Reviews

    Science.gov (United States)

    Giraudeau, Bruno; Leyrat, Clémence; Le Gouge, Amélie; Léger, Julie; Caille, Agnès

    2011-01-01

    Grant proposals submitted for funding are usually selected by a peer-review rating process. Some proposals may result in discordant peer-review ratings and therefore require discussion by the selection committee members. The issue is which peer-review ratings are considered as discordant. We propose a simple method to identify such proposals. Our approach is based on the intraclass correlation coefficient, which is usually used in assessing agreement in studies with continuous ratings. PMID:22110670

  11. Peer review of grant applications: a simple method to identify proposals with discordant reviews.

    Directory of Open Access Journals (Sweden)

    Bruno Giraudeau

    Full Text Available Grant proposals submitted for funding are usually selected by a peer-review rating process. Some proposals may result in discordant peer-review ratings and therefore require discussion by the selection committee members. The issue is which peer-review ratings are considered as discordant. We propose a simple method to identify such proposals. Our approach is based on the intraclass correlation coefficient, which is usually used in assessing agreement in studies with continuous ratings.

  12. Is that me or my twin? Lack of self-face recognition advantage in identical twins.

    Science.gov (United States)

    Martini, Matteo; Bufalari, Ilaria; Stazi, Maria Antonietta; Aglioti, Salvatore Maria

    2015-01-01

    Despite the increasing interest in twin studies and the stunning amount of research on face recognition, the ability of adult identical twins to discriminate their own faces from those of their co-twins has been scarcely investigated. One's own face is the most distinctive feature of the bodily self, and people typically show a clear advantage in recognizing their own face even more than other very familiar identities. Given the very high level of resemblance of their faces, monozygotic twins represent a unique model for exploring self-face processing. Herein we examined the ability of monozygotic twins to distinguish their own face from the face of their co-twin and of a highly familiar individual. Results show that twins equally recognize their own face and their twin's face. This lack of self-face advantage was negatively predicted by how much they felt physically similar to their co-twin and by their anxious or avoidant attachment style. We speculate that in monozygotic twins, the visual representation of the self-face overlaps with that of the co-twin. Thus, to distinguish the self from the co-twin, monozygotic twins have to rely much more than control participants on the multisensory integration processes upon which the sense of bodily self is based. Moreover, in keeping with the notion that attachment style influences perception of self and significant others, we propose that the observed self/co-twin confusion may depend upon insecure attachment. PMID:25853249

  13. HIV and HCV discordant injecting partners and their association to drug equipment sharing.

    Science.gov (United States)

    De, Prithwish; Cox, Joseph; Boivin, Jean-Francois; Platt, Robert W; Jolly, Ann M; Alexander, Paul E

    2009-01-01

    Our objective was to examine the association between HIV and HCV discordant infection status and the sharing of drug equipment by injection drug users (IDUs). IDUs were recruited from syringe exchange and methadone treatment programmes in Montreal, Canada. Characteristics of participants and their injecting partners were elicited using a structured questionnaire. Among 159 participants and 245 injecting partners, sharing of syringes and drug preparation equipment did not differ between concordant or discordant partners, although HIV-positive subjects did not share with HIV-negative injectors. Sharing of syringes was positively associated with discordant HIV status (OR=1.85) and negatively with discordant HCV status (OR=0.65), but both results were not statistically significant. Sharing of drug preparation equipment was positively associated with both discordant HIV (OR=1.61) and HCV (OR=1.18) status, but both results were non-significant. Factors such as large injecting networks, frequent mutual injections, younger age, and male gender were stronger predictors of equipment sharing. In conclusion, IDUs do not appear to discriminate drug equipment sharing partners based at least on their HCV infection status. The results warrant greater screening to raise awareness of infection status, post-test counselling to promote status disclosure among partners, and skill-building to avoid equipment sharing between discordant partners. PMID:19172434

  14. An artificial neural network approach for the discordance sensor data validation for SCRAM parameters

    International Nuclear Information System (INIS)

    In Fast Breeder Reactor (FBR), shutdown system is envisaged by Safety and Control Rod Acceleration Movement by using (SCRAM) signals. These SCRAM signals are realized with redundant triplicate sensors, which are made available at different locations of reactor. In this case sensors should be in healthy condition to run the reactor in trouble free manner. To know the health status of sensors a monitoring system is necessary. For this purpose, discordance supervision system is envisaged, to monitor the discordance among the SCRAM signal sensors and generate the alarm when discordance occurs. If discordance occurs, the sensor data validation is necessary to justify the discordance. The sensor data validation by knowledge based approach is simple and reliable. The discordance data is obtained from SCRAM signals. To validate these sensors data value, a neural network based approach is used. The proposed technique is used the data obtained from the coolant temperature monitoring system and relevant application is reported in this paper. The results of this investigation are discussed in this paper. (authors)

  15. An artificial neural network approach for the discordance sensor data validation for SCRAM parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kasinathan, M.; Murali, N. [RTSD, EIG, Indira Gandhi Centre for Atomic Research, Kalpakkam -603102 (India); Saidhar Rao, B. [SES, RTSD, EIG, Indira Gandhi Centre for Atomic Research, Kalpakkam -603102 (India); Swaminathan, P. [EIG, Indira Gandhi Centre for Atomic Research, Kalpakkam -603102 (India)

    2009-07-01

    In Fast Breeder Reactor (FBR), shutdown system is envisaged by Safety and Control Rod Acceleration Movement by using (SCRAM) signals. These SCRAM signals are realized with redundant triplicate sensors, which are made available at different locations of reactor. In this case sensors should be in healthy condition to run the reactor in trouble free manner. To know the health status of sensors a monitoring system is necessary. For this purpose, discordance supervision system is envisaged, to monitor the discordance among the SCRAM signal sensors and generate the alarm when discordance occurs. If discordance occurs, the sensor data validation is necessary to justify the discordance. The sensor data validation by knowledge based approach is simple and reliable. The discordance data is obtained from SCRAM signals. To validate these sensors data value, a neural network based approach is used. The proposed technique is used the data obtained from the coolant temperature monitoring system and relevant application is reported in this paper. The results of this investigation are discussed in this paper. (authors)

  16. Enhancing Quantum Discord in Cavity QED by Applying Classical Driving Field

    Institute of Scientific and Technical Information of China (English)

    QIAN Yi; XU Jing-Bo

    2012-01-01

    We investigate the quantum discord dynamics in a cavity quantum electrodynamics system, which consists of two noninteracting two-level atoms driven by independent optical Gelds and classical fields, and find that the quantum discord vanishes only asymptotically although entanglement disappears suddenly during the time evolution in the absence of classical fields. It is shown that the amount of quantum discord can be increased by adjusting the classical driving fields because the increasing degree of the amount of quantum mutual information is greater than classical correlation by applying the classical driving fields. Finally, the influence of the classical driving field on the fidelity of the system is also examined.%We investigate the quantum discord dynamics in a cavity quantum electrodynamics system,which consists of two noninteracting two-level atoms driven by independent optical fields and classical fields,and find that the quantum discord vanishes only asymptotically although entanglement disappears suddenly during the time evolution in the absence of classical fields.It is shown that the amount of quantum discord can be increased by adjusting the classical driving fields because the increasing degree of the amount of quantum mutual information is greater than classical correlation by applying the classical driving fields.Finally,the influence of the classical driving field on the fidelity of the system is also examined.

  17. Compositional discordance between prokaryotic plasmids and host chromosomes

    Directory of Open Access Journals (Sweden)

    van Kampen Antoine HC

    2006-02-01

    Full Text Available Abstract Background Most plasmids depend on the host replication machinery and possess partitioning genes. These properties confine plasmids to a limited range of hosts, yielding a close and presumably stable relationship between plasmid and host. Hence, it is anticipated that due to amelioration the dinucleotide composition of plasmids is similar to that of the genome of their hosts. However, plasmids are also thought to play a major role in horizontal gene transfer and thus are frequently exchanged between hosts, suggesting dinucleotide composition dissimilarity between plasmid and host genome. We compared the dinucleotide composition of a large collection of plasmids with that of their host genomes to shed more light on this enigma. Results The dinucleotide frequency, coined the genome signature, facilitates the identification of putative horizontally transferred DNA in complete genome sequences, since it was found to be typical for a certain genome, and similar between related species. By comparison of the genome signature of 230 plasmid sequences with that of the genome of each respective host, we found that in general the genome signature of plasmids is dissimilar from that of their host genome. Conclusion Our results show that the genome signature of plasmids does not resemble that of their host genome. This indicates either absence of amelioration or a less stable relationship between plasmids and their host. We propose an indiscriminate lifestyle for plasmids preserving the genome signature discordance between these episomes and host chromosomes.

  18. Discordant phenotype in siblings with X-linked agammaglobulinemia

    Energy Technology Data Exchange (ETDEWEB)

    Bykowsky, M.J.; Veksler, K.S.; Sullivan, K.E. [Children`s Hospital, Philadelphia, PA (United States)] [and others

    1996-03-01

    X-linked agammaglobulinemia (XLA) is a congenital humoral immunodeficiency caused by a defect in a B-cell-specific signaling molecule, Btk. There has been little concordance of phenotype with genotype in this disorder, and defects in Btk cause immunodeficiencies that range from mild impairment to complete inability to produce antibodies. The factors modifying the phenotype of XLA are not understood. The current study is the first description of two male siblings with identical T{sup 134}{yields}C mutations in the translation initiation ATG of Btk who have different clinical phenotypes as well as different laboratory phenotypes. The proband lacks immunoglobulins and B cells and has recurrent infections, while the elder, affected brother has normal levels of IgG and IgM and very few infections. Both have undetectable levels of Btk kinase activity in circulating mononuclear cells. Complete sequencing of Btk gene transcripts in both brothers revealed no additional mutations to account for the discordant phenotypes. This description provides unequivocal evidence that the phenotype of XLA is influenced by factors additional to the Btk gene. 39 refs., 3 figs., 3 tabs.

  19. Twin Research and the Arts: Interconnections / Twin Research: Twin Studies of Sexual Orientation; A Historical Biological Twin Gem; GWAS Approach to Who Has Twins / Newsworthy: Twins on College Campuses; 'Brainprint': Personal Identification by Brain Waves.

    Science.gov (United States)

    Segal, Nancy L

    2016-08-01

    The interrelatedness between twin research and the arts is explored via a new play about a famous case. In the 1960s, identical twin David Bruce Reimer was accidentally castrated as an infant during circumcision to correct a urinary problem. The decision to raise him as a girl, and the consequences of that decision, are explored in the new theatrical production of Boy. Other examples of the arts mirroring science, and vice versa, are described. Next, brief reviews and summaries of twin research on sexual orientation, 1860s' knowledge of placental arrangements and twinning mechanisms, and genes underlying multiple birth conception and fertility related measures are provided. This article concludes with a look at twins on college campuses and the identification of individuals by their brain waves. A correction and clarification regarding my article on the Brazilian Twin Registry in the last issue of THG (Segal, 2016) is also provided. PMID:27436054

  20. Characterizing Blood Metabolomics Profiles Associated with Self-Reported Food Intakes in Female Twins.

    Science.gov (United States)

    Pallister, Tess; Jennings, Amy; Mohney, Robert P; Yarand, Darioush; Mangino, Massimo; Cassidy, Aedin; MacGregor, Alexander; Spector, Tim D; Menni, Cristina

    2016-01-01

    Using dietary biomarkers in nutritional epidemiological studies may better capture exposure and improve the level at which diet-disease associations can be established and explored. Here, we aimed to identify and evaluate reproducibility of novel biomarkers of reported habitual food intake using targeted and non-targeted metabolomic blood profiling in a large twin cohort. Reported intakes of 71 food groups, determined by FFQ, were assessed against 601 fasting blood metabolites in over 3500 adult female twins from the TwinsUK cohort. For each metabolite, linear regression analysis was undertaken in the discovery group (excluding MZ twin pairs discordant [≥1 SD apart] for food group intake) with each food group as a predictor adjusting for age, batch effects, BMI, family relatedness and multiple testing (1.17x10-6 = 0.05/[71 food groups x 601 detected metabolites]). Significant results were then replicated (non-targeted: Pfood groups (Pconsumption (0.181[0.019]; P = 5.93x10-22), and three potential markers of fruit consumption (top association: apple and pears): including metabolites derived from gut bacterial transformation of phenolic compounds, 3-phenylpropionate (0.024[0.004]; P = 1.24x10-8) and indolepropionate (0.026[0.004]; P = 2.39x10-9), and threitol (0.033[0.003]; P = 1.69x10-21). With the largest nutritional metabolomics dataset to date, we have identified 73 novel candidate biomarkers of food intake for potential use in nutritional epidemiological studies. We compiled our findings into the DietMetab database (http://www.twinsuk.ac.uk/dietmetab-data/), an online tool to investigate our top associations. PMID:27355821

  1. Cerebral palsy in the surviving twin associated with infant death of the co-twin

    OpenAIRE

    Pharoah, P.

    2001-01-01

    BACKGROUND—Monozygotic twins are at greater risk of dying and of serious morbidity than dizygotic twins, and both are at greater risk than singletons. This is only partly explained by the higher proportion of low birthweight infants among twins.
AIM—To compare, in same sex and different sex twins, birth weight specific neonatal death rates and cerebral palsy prevalence rates in the surviving twin when the co-twin has died in infancy.
METHODS—Analysis of birth and death...

  2. Studies of X inactivation and isodisomy in twins provide further evidence that the X chromosomes is not involved in Rett syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Migeon, B.R.; Dunn, M.A.; Schmeckpeper, B.J.; Naidu, S. [Johns Hophins Univ., Baltimore, MD (United States); Thomas, G. [Johns Hopkins Univ., Baltimore, MD (United States)]|[Kennedy-Kreiger Institute, Baltimore, MD (United States)

    1995-03-01

    Rett syndrome (RS), a progressive encephalopathy with onset in infancy, has been attributed to an X-linked mutation, mainly on the basis of its occurrence almost exclusively in females and its concordance in female MZ twins. The underlying mechanisms proposed are an X-linked dominant mutation with male lethality, uniparental disomy of the X chromosome, and/or some disturbance in the process of X inactivation leading to unequal distribution of cells expressing maternal or paternal alleles (referred to as a {open_quotes}nonrandom{close_quotes} or {open_quotes}skewed {close_quotes} inactivation). To determine if the X chromosome is in fact involved in RS, we studied a group of affected females including three pairs of MZ twins, two concordant for RS and one uniquely discordant for RS. Analysis of X-inactivation patterns confirms the frequent nonrandom X inactivation previously observed in MZ twins but indicates that this is independent of RS. Analysis of 29 RS females reveals not one instance of uniparental X disomy, extending the observations previously reported. Therefore, our findings contribute no support for the hypothesis that RS is an X-linked disorder. Furthermore, the concordant phenotype in most MZ females twins with RS, which has not been observed in female twins with known X-linked mutations, argues against an X mutation. 41 refs., 2 figs.

  3. Deformation twinning: Influence of strain rate

    Energy Technology Data Exchange (ETDEWEB)

    Gray, G.T. III

    1993-11-01

    Twins in most crystal structures, including advanced materials such as intermetallics, form more readily as the temperature of deformation is decreased or the rate of deformation is increased. Both parameters lead to the suppression of thermally-activated dislocation processes which can result in stresses high enough to nucleate and grow deformation twins. Under high-strain rate or shock-loading/impact conditions deformation twinning is observed to be promoted even in high stacking fault energy FCC metals and alloys, composites, and ordered intermetallics which normally do not readily deform via twinning. Under such conditions and in particular under the extreme loading rates typical of shock wave deformation the competition between slip and deformation twinning can be examined in detail. In this paper, examples of deformation twinning in the intermetallics TiAl, Ti-48Al-lV and Ni{sub 3}A as well in the cermet Al-B{sub 4}C as a function of strain rate will be presented. Discussion includes: (1) the microstructural and experimental variables influencing twin formation in these systems and twinning topics related to high-strain-rate loading, (2) the high velocity of twin formation, and (3) the influence of deformation twinning on the constitutive response of advanced materials.

  4. Twinning in magnesium under dynamic loading

    Directory of Open Access Journals (Sweden)

    Dixit Neha

    2015-01-01

    Full Text Available Twinning is an important mode of deformation in magnesium (Mg and its alloys at high strain rates. Twinning in this material leads to important effects such as mechanical anisotropy, texture evolution, tension-compression asymmetry, and sometimes non-Schmid effects. Extension twins in Mg can accommodate significant plastic deformation as they grow, and thus twinning affects the overall rate of plastic deformation. We use an experimental approach to study the deformation twinning mechanism under dynamic loading. We perform normal plate impact recovery experiments (with microsecond pulse durations on pure polycrystalline Mg specimens. Estimates of average TB velocity under the known impact stress are obtained by characterization of twin sizes and aspect ratios developed within the target during the loading pulse. The measured average TB velocities in our experiments are of the order of several m s−1. These velocities are several orders of magnitude higher than those so far measured in Mg under quasi-static loading conditions. Electron back-scattered diffraction (EBSD is then used to characterize the nature of the twins and the microstructural evolution. Detailed crystallographic analysis of the twins enables us to understand twin nucleation and growth of twin variants under dynamic loading.

  5. Fingerprint recognition with identical twin fingerprints.

    Directory of Open Access Journals (Sweden)

    Xunqiang Tao

    Full Text Available Fingerprint recognition with identical twins is a challenging task due to the closest genetics-based relationship existing in the identical twins. Several pioneers have analyzed the similarity between twins' fingerprints. In this work we continue to investigate the topic of the similarity of identical twin fingerprints. Our study was tested based on a large identical twin fingerprint database that contains 83 twin pairs, 4 fingers per individual and six impressions per finger: 3984 (83*2*4*6 images. Compared to the previous work, our contributions are summarized as follows: (1 Two state-of-the-art fingerprint identification methods: P071 and VeriFinger 6.1 were used, rather than one fingerprint identification method in previous studies. (2 Six impressions per finger were captured, rather than just one impression, which makes the genuine distribution of matching scores more realistic. (3 A larger sample (83 pairs was collected. (4 A novel statistical analysis, which aims at showing the probability distribution of the fingerprint types for the corresponding fingers of identical twins which have same fingerprint type, has been conducted. (5 A novel analysis, which aims at showing which finger from identical twins has higher probability of having same fingerprint type, has been conducted. Our results showed that: (a A state-of-the-art automatic fingerprint verification system can distinguish identical twins without drastic degradation in performance. (b The chance that the fingerprints have the same type from identical twins is 0.7440, comparing to 0.3215 from non-identical twins. (c For the corresponding fingers of identical twins which have same fingerprint type, the probability distribution of five major fingerprint types is similar to the probability distribution for all the fingers' fingerprint type. (d For each of four fingers of identical twins, the probability of having same fingerprint type is similar.

  6. Ectodermal dysplasia in identical twins

    OpenAIRE

    Gurkar Haraswarupa Puttaraju; Paranjyothi Magadi Visveswariah

    2013-01-01

    Hereditary hypohidrotic ectodermal dysplasia (HED) is typically inherited as an X-linked recessive trait, characterized by deformity of at least two or more of the ectodermal structures - hair, teeth, nails and sweat glands. Two cases of hereditary HED involving identical male twins, is being documented for the rarity of its occurrence with special attention given to genetics, pathophysiology, clinical, intraoral manifestations and to the methods to improve the masticatory function, the facia...

  7. Twin Sessions Through African Eyes

    Institute of Scientific and Technical Information of China (English)

    Ni Yanshuo

    2012-01-01

    Every year journalists from around China and the world flock to Beijing in March to cover the sessions of the National People's Congress (NPC) and the Chinese People's Political Consultative Conference (CPPCC), known as the lianghui, or twin sessions. With the deepening of Sino-African relations in the past decades, an increasing number of African journalists are involved in reporting China's lianghui to their audiences in Africa.

  8. MERMAID BABY IN TWIN PREGNANCY

    Directory of Open Access Journals (Sweden)

    Alpana

    2014-03-01

    Full Text Available Sirenomelia, alternatively known as mermaid syndrome is a very rare congenital anomaly in which the legs are fused together, giving the appearance of a mermaid's tail. Till date less than 60 cases had been reported. We came across a twin pregnancy in which a normal female baby and another mermaid baby was delivered. The rarity and uniqueness of the syndrome prompted us to report the case.

  9. MERMAID BABY IN TWIN PREGNANCY

    OpenAIRE

    Alpana; Dipanwita; Sweta; Rachna; Gita

    2014-01-01

    Sirenomelia, alternatively known as mermaid syndrome is a very rare congenital anomaly in which the legs are fused together, giving the appearance of a mermaid's tail. Till date less than 60 cases had been reported. We came across a twin pregnancy in which a normal female baby and another mermaid baby was delivered. The rarity and uniqueness of the syndrome prompted us to report the case.

  10. Identical twins in forensic genetics

    DEFF Research Database (Denmark)

    Tvedebrink, Torben; Morling, Niels

    2015-01-01

    The increase in the number of forensic genetic loci used for identification purposes results in infinitesimal random match probabilities. These probabilities are computed under assumptions made for rather simple population genetic models. Often, the forensic expert reports likelihood ratios, where...... published results accounting for close familial relationships. However, we revisit the discussion to increase the awareness among forensic genetic practitioners and include new information on medical and societal factors to assess the risk of not considering a monozygotic twin as the true perpetrator...

  11. Thrombosis of anastomoses may affect the staging sequence of twin-twin transfusion syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Wijngaard, Jeroen P H M van den; Gemert, Martin J C van [Laser Center, Academic Medical Center-University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam (Netherlands); Ross, Michael G [Department of Obstetrics and Gynecology, Harbor-UCLA School of Medicine, Torrance, CA 90502 (United States)], E-mail: j.p.vandenwijngaard@amc.uva.nl

    2008-03-07

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. (note)

  12. Thrombosis of anastomoses may affect the staging sequence of twin-twin transfusion syndrome

    International Nuclear Information System (INIS)

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. (note)

  13. Macrodeformation Twins in Single-Crystal Aluminum

    Science.gov (United States)

    Zhao, F.; Wang, L.; Fan, D.; Bie, B. X.; Zhou, X. M.; Suo, T.; Li, Y. L.; Chen, M. W.; Liu, C. L.; Qi, M. L.; Zhu, M. H.; Luo, S. N.

    2016-02-01

    Deformation twinning in pure aluminum has been considered to be a unique property of nanostructured aluminum. A lingering mystery is whether deformation twinning occurs in coarse-grained or single-crystal aluminum at scales beyond nanotwins. Here, we present the first experimental demonstration of macrodeformation twins in single-crystal aluminum formed under an ultrahigh strain rate (˜106 s-1 ) and large shear strain (200%) via dynamic equal channel angular pressing. Large-scale molecular dynamics simulations suggest that the frustration of subsonic dislocation motion leads to transonic deformation twinning. Deformation twinning is rooted in the rate dependences of dislocation motion and twinning, which are coupled, complementary processes during severe plastic deformation under ultrahigh strain rates.

  14. Twinning of Polymer Crystals Suppressed by Entropy

    Directory of Open Access Journals (Sweden)

    Nikos Ch. Karayiannis

    2014-09-01

    Full Text Available We propose an entropic argument as partial explanation of the observed scarcity of twinned structures in crystalline samples of synthetic organic polymeric materials. Polymeric molecules possess a much larger number of conformational degrees of freedom than low molecular weight substances. The preferred conformations of polymer chains in the bulk of a single crystal are often incompatible with the conformations imposed by the symmetry of a growth twin, both at the composition surfaces and in the twin axis. We calculate the differences in conformational entropy between chains in single crystals and chains in twinned crystals, and find that the reduction in chain conformational entropy in the twin is sufficient to make the single crystal the stable thermodynamic phase. The formation of cyclic twins in molecular dynamics simulations of chains of hard spheres must thus be attributed to kinetic factors. In more realistic polymers this entropic contribution to the free energy can be canceled or dominated by nonbonded and torsional energetics.

  15. Is That Me or My Twin? Lack of Self-Face Recognition Advantage in Identical Twins

    OpenAIRE

    Martini, Matteo; Bufalari, Ilaria; Stazi, Maria Antonietta; Aglioti, Salvatore Maria

    2015-01-01

    Despite the increasing interest in twin studies and the stunning amount of research on face recognition, the ability of adult identical twins to discriminate their own faces from those of their co-twins has been scarcely investigated. One’s own face is the most distinctive feature of the bodily self, and people typically show a clear advantage in recognizing their own face even more than other very familiar identities. Given the very high level of resemblance of their faces, monozygotic twins...

  16. Bilateral Norrie's disease in identical twins.

    OpenAIRE

    Sukumaran, K

    1991-01-01

    A case of Norrie's disease in an identical twins is reported. No positive family history was obtained. The couple had no other children. The older of the twins died at the age of 9 months of uncertain cause. To the best of my knowledge this is the first case of Norrie's disease reported in Malaysia. And its occurrence in an identical twins is very rare.

  17. Crystallographic orientations and twinning of electrodeposited nickel

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; da Silva Fanta, Alice Bastos; Somers, Marcel A. J.; Pantleon, Karen

    2014-01-01

    of twins and the preferred crystallographic orientations of grains in the electrodeposits. Additive-free deposition results in relatively large columnar grains with numerous growth twins of nanoscale dimensions. The presence of the additive in the electrolyte yields considerable grain refinement...... already at low additive concentration, but the preferred crystallographic orientation of grains changes gradually with increasing additive concentration and twins with nanoscale dimensions are detected also in these samples....

  18. Anaesthesia for the separation of conjoined twins

    OpenAIRE

    Jaya Lalwani; K P Dubey; Pratibha Shah

    2011-01-01

    Thoraco-omphalopagus is one of the most common type of conjoint twins accounting for 74% cases of conjoint twins. We report the anaesthetic management for successful separation of thoraco-omphalopagus conjoint twins, both of them surviving till date. We highlight the responsibility of anaesthesia team in anaesthetising the two individual patients simultaneously, need of careful monitoring and anticipation of complications like massive blood loss, hypotension, hypokalemia, hypoxia and hypercab...

  19. Infantile spasms syndrome in monozygotic twins.

    OpenAIRE

    Pavone, L; Mollica, F; Incorpora, G; Pampiglione, G

    1980-01-01

    The infantile spasms syndrome appeared on the same day in a pair of monozygotic twins at age 6 months. Clinical, electroencephalographic, and neuroradiological findings during the development of the disease are reported. One of the twins was treated with ACTH and in his case clinical and electroencephalographic improvement was more rapid than in the other who was treated with clonazepam. While the computer tomography scan initially showed in each twin an area of low density in the right front...

  20. Anaesthesia for the separation of conjoined twins

    Directory of Open Access Journals (Sweden)

    Jaya Lalwani

    2011-01-01

    Full Text Available Thoraco-omphalopagus is one of the most common type of conjoint twins accounting for 74% cases of conjoint twins. We report the anaesthetic management for successful separation of thoraco-omphalopagus conjoint twins, both of them surviving till date. We highlight the responsibility of anaesthesia team in anaesthetising the two individual patients simultaneously, need of careful monitoring and anticipation of complications like massive blood loss, hypotension, hypokalemia, hypoxia and hypercabia. Detailed description of successful management is reported.

  1. The Solar Twin Planet Search II. A Jupiter twin around a solar twin

    CERN Document Server

    Bedell, M; Bean, J L; Ramirez, I; Asplund, M; Alves-Brito, A; Casagrande, L; Dreizler, S; Monroe, T; Spina, L; Maia, M Tucci

    2015-01-01

    Through our HARPS radial velocity survey for planets around solar twin stars, we have identified a promising Jupiter twin candidate around the star HIP11915. We characterize this Keplerian signal and investigate its potential origins in stellar activity. Our analysis indicates that HIP11915 hosts a Jupiter-mass planet with a 3600-day orbital period and low eccentricity. Although we cannot definitively rule out an activity cycle interpretation, we find that a planet interpretation is more likely based on a joint analysis of RV and activity index data. The challenges of long-period radial velocity signals addressed in this paper are critical for the ongoing discovery of Jupiter-like exoplanets. If planetary in nature, the signal investigated here represents a very close analog to the solar system in terms of both Sun-like host star and Jupiter-like planet.

  2. Idiopathic Hypertrophic Pyloric Stenosis in Identical Twins.

    Directory of Open Access Journals (Sweden)

    Ju-Bei Yen

    2003-12-01

    Full Text Available Idiopathic hypertrophic pyloric stenosis (IHPS was thought to be a congenital diseasetraditionally, even though several published reports assumed IHPS was an acquired disease.The pathogenesis and inheritance patterns of IHPS are not fully understood. Except for thefamilial recurrence of IHPS, concordance of IHPS in monozygotic or dizygotic twins wasalso noted, but occurrence in female twins is rare. From July 1992 through June 2000, 130patients were diagnosed with IHPS in our hospital including one pair of female twins. Wepresent the finding in the twins and review the associated articles about the pathogenesis andinheritance patterns of IHPS.

  3. Siamese twins in the United Arab Emirates.

    Science.gov (United States)

    el-Gohary, M A

    1998-03-01

    In the years 1985-1992, ten pairs of conjoined twins were born in the United Arab Emirates (UAE): one dicephalus, two teratopagi, and seven thoracoomphalopagi, one of which was still-born and three who were cared for in other hospitals. The first pair of thoraco-omphalopagus twins died of acute lymphoblastic leukaemia 6 months after successful separation. The management of the third set of twins gave rise to moral and ethical problems often encountered in such situations, while one of the teratopagi was a unique case of a parasite projecting from the mouth of the normal twin. PMID:9563031

  4. Paternal age and telomere length in twins

    DEFF Research Database (Denmark)

    Hjelmborg, Jacob B; Dalgård, Christine; Mangino, Massimo; Spector, Tim D; Halekoh, Ulrich; Möller, Sören; Kimura, Masayuki; Horvath, Kent; Kark, Jeremy D; Christensen, Kaare; Kyvik, Kirsten O; Aviv, Abraham

    2015-01-01

    Telomere length, a highly heritable trait, is longer in offspring of older fathers. This perplexing feature has been attributed to the longer telomeres in sperm of older men and it might be an 'epigenetic' mechanism through which paternal age plays a role in telomere length regulation in humans....... Based on two independent (discovery and replication) twin studies, comprising 889 twin pairs, we show an increase in the resemblance of leukocyte telomere length between dizygotic twins of older fathers, which is not seen in monozygotic twins. This phenomenon might result from a paternal age...

  5. Invasive treatment in complicated monochorionic twin pregnancies

    DEFF Research Database (Denmark)

    Sundberg, Karin; Søgaard, Kirsten; Jensen, Lisa Neerup; Schou, Katrine Vasehus; Jørgensen, Connie

    2012-01-01

    Objective. Monochorionic twin pregnancies are associated with increased risk of severe complications. Umbilical cord occlusion (UCO) and fetoscopic selective laser coagulation (FSLC) are used as invasive treatment. The study aim was to document treatment indications and pregnancy outcome where UCO...... and FSLC were used for treating fetal discrepancies and twin-to-twin transfusion syndrome (TTTS). Design. Cohort study of all consecutively treated monochorionic twin pregnancies 2004-2010. Setting. Tertiary care center. Population. One hundred and twenty pregnancies treated by FSLC (55) or UCO (65...

  6. Heteropagus twins: report of two cases

    OpenAIRE

    Fierling, R; Däster, C; Arlettaz, R

    2015-01-01

    Heteropagus twins are an extremely rare form of asymmetrical conjoined monochorial monoamniotic twins with an estimated incidence of less than one per one million live births (1). An often-used synonym is «parasitic twins». The term heteropagus describes twins in which one of them has a mostly intact body that is able to survive and which is referred to as «autosite», while the ounterpart, referred to as «parasite», is only rudimentarily developed being physically attached to and nourished...

  7. Twin-twin transfusion syndrome (TTTS) : outcomes with special reference to cardiovascular function

    OpenAIRE

    Pegelow Halvorsen, Cecilia

    2013-01-01

    Background Fetal environment has become a subject for increasing interest when studying health and disease in adults. Monozygous (MZ) twins, especially gestations complicated with twin - twin transfusion syndrome (TTTS), offer a unique opportunity to study adverse developmental programming of the cardiovascular system. TTTS affects about 10% of pregnancies with a common placenta because of unbalanced blood flow across deep arteriovenous connecting vessels . ...

  8. Problem in twin pregnancy: Findings of prenatal sonography and autopsy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Ah; Cho, Jeong Yeon; Song, Mi Jin; Min, Jee Yeon; Lee, Young Ho; Lee, Hak Jong; Chun, Yi Kyeong; Kim, Yee Jeong; Hong, Sung Ran [Samsung Cheil Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2001-12-15

    Multifetal gestations are high risk pregnancies with higher perinatal morbidity and mortality. Multifetal gestations are subject to unique complications including conjoined twins, twin-to-twin transfusion syndrome (TTTS), acardiac twins, twin embization of co-twin demise and heterotopic pregnancies. Prenatal sonographic diagnosis of types and complications of multifetal gestations is important for antenatal care and prediction of fetal outcome. This study was performed to present the prenatal ultrasonographic findings and pathologic findings of the unique complications of twin pregnancy. Acardia is a lethal anomaly occurring in 1% of monozygotic twin. The acardiac twin has a parasitic existence and depends on the donor (pump) twin for its blood supply via placental anastomoses and retrograde perfusion of umbilical cord. This twin reversed arterial perfusion (TRAP) sequence is a most extreme manifestation on the TTTS. Doppler verification reversed flow in umbilical cord of the acardiac twin confirms the diagnosis.

  9. Problem in twin pregnancy: Findings of prenatal sonography and autopsy

    International Nuclear Information System (INIS)

    Multifetal gestations are high risk pregnancies with higher perinatal morbidity and mortality. Multifetal gestations are subject to unique complications including conjoined twins, twin-to-twin transfusion syndrome (TTTS), acardiac twins, twin embization of co-twin demise and heterotopic pregnancies. Prenatal sonographic diagnosis of types and complications of multifetal gestations is important for antenatal care and prediction of fetal outcome. This study was performed to present the prenatal ultrasonographic findings and pathologic findings of the unique complications of twin pregnancy. Acardia is a lethal anomaly occurring in 1% of monozygotic twin. The acardiac twin has a parasitic existence and depends on the donor (pump) twin for its blood supply via placental anastomoses and retrograde perfusion of umbilical cord. This twin reversed arterial perfusion (TRAP) sequence is a most extreme manifestation on the TTTS. Doppler verification reversed flow in umbilical cord of the acardiac twin confirms the diagnosis.

  10. Discordant Treatment Responses to Combination Antiretroviral Therapy in Rwanda: A Prospective Cohort Study

    Science.gov (United States)

    Kayigamba, Felix R.; Franke, Molly F.; Bakker, Mirjam I.; Rodriguez, Carly A.; Bagiruwigize, Emmanuel; Wit, Ferdinand WNM; Rich, Michael L.; Schim van der Loeff, Maarten F.

    2016-01-01

    Introduction Some antiretroviral therapy naïve patients starting combination antiretroviral therapy (cART) experience a limited CD4 count rise despite virological suppression, or vice versa. We assessed the prevalence and determinants of discordant treatment responses in a Rwandan cohort. Methods A discordant immunological cART response was defined as an increase of health facilities in two regions in Rwanda. Results Among 382 patients with an undetectable VL at 12 months, 112 (29%) had a CD4 rise of travel to the clinic were independent determinants of an immunological discordant response, but sex, baseline CD4 count, body mass index and WHO HIV clinical stage were not. Among 326 patients with a CD4 rise of ≥100 cells/mm3, 56 (17%) had a detectable viral load at 12 months. Male sex was associated with a virological discordant treatment response (P = 0.05), but age, baseline CD4 count, BMI, WHO HIV clinical stage, and travel time to the clinic were not. Conclusions Discordant treatment responses were common in cART-naïve HIV patients in Rwanda. Small CD4 increases could be misinterpreted as a (virological) treatment failure and lead to unnecessary treatment changes. PMID:27438000

  11. Subjects with Discordant Airways Obstruction: Lost between Spirometric Definitions of COPD

    Directory of Open Access Journals (Sweden)

    Bernd Lamprecht

    2011-01-01

    Full Text Available Background. Since the FEV1/FVC ratio declines with age, using the fixed ratio of 0.70 leads to overdiagnosis of COPD in older populations and underdiagnosis among young adults. Objective. To evaluate whether discordant obstructive cases (FEV1/FVC < 0.70 but ≥LLN are a healthy population or have clinical features that would place them at increased risk. Methods. We used post-bronchodilator spirometry data from the population-based Austrian Burden of Obstructive Lung Disease (BOLD study. Those with post-bronchodilator FEV1/FVC ratio discordant obstructive cases. Results. Discordant obstructive cases were more likely to be older, male and never-smokers. Additionally they had less respiratory symptoms and less severe impairment of FEV1. However, discordant obstructive cases reported significantly more often a diagnosis of heart disease than subjects with normal lung function (27.2% vs 7.3%, P=.015. Conclusion. The clinical profile of discordant obstructive cases includes potentially important comorbid disease.

  12. Characterization of Sera with Discordant Results from Reverse Sequence Screening for Syphilis

    Directory of Open Access Journals (Sweden)

    Kyunghoon Lee

    2013-01-01

    Full Text Available Reverse sequence screening for syphilis (RSSS (screening with treponemal tests, followed by confirmation with nontreponemal tests has been increasingly adopted. CDC recommends confirmation of discordant results (reactive EIA/CIA and nonreactive nontreponemal test with Treponema pallidum particle agglutination assay (TP-PA. We characterized sera with discordant results from RSSS with Architect Syphilis TP CIA. Among 15,713 screening tests using Architect Syphilis TP at Seoul National University Gangnam Center between October 2010 and May 2011, 260 (1.7% showed reactive results. Rapid plasma reagin (RPR and TP-PA were performed on 153 available sera among them. On sera with discordant results between Architect Syphilis TP and TP-PA, INNO-LIA Syphilis Score and FTA-ABS were performed. Among 153 sera, RPR was nonreactive in 126 (82.4%. Among them, TP-PA was positive in 103 (81.7%, indeterminate (± in 7 (5.6%, and negative in 16 (12.7%. Out of 16 CIA(+/RPR(−/TP-PA(− sera, INNO-LIA Syphilis Score and/or FTA-ABS were negative on 14 sera. Out of 7 CIA(+/RPR(−/TP-PA(± sera, INNO-LIA Syphilis Score and FTA-ABS were positive/reactive in 6 sera. RSSS with confirmation by TP-PA on sera with discordant results between Architect Syphilis TP and RPR effectively delineated those discordant results and could be successfully adopted for routine checkup for syphilis.

  13. Impact of the Xba1-polymorphism of the human muscle glycogen synthase gene on parameters of the insulin resistance syndrome in a Danish twin population

    DEFF Research Database (Denmark)

    Fenger, M; Poulsen, P; Beck-Nielsen, H;

    2000-01-01

    and the remainder had the genotype A1A2. No A2A2-genotypes were detected. In 11 genotypic discordant dizygotic twin pairs the insulin resistance was significantly increased in the twins carrying the A1A2 genotype regardless of sex (HOMA index 1.81 (A1A1) vs. 2.57 (A1A2), P < 0.05). Diastolic blood...... pressure was increased in female carriers of the A2-allele with impaired glucose tolerance or Type 2 diabetes mellitus (79 +/- 1 vs. 94 +/- 4 mmHg, P < 0.01). Apart from a marginal increased waist-to-hip ratio, no other elements of the insulin resistance syndrome were associated with the polymorphism...

  14. Early Prenatal Diagnosis of Thoracopagus Twins by Ultrasound

    OpenAIRE

    Alkhateeb, Mahmoud; Mashaqbeh, Mahmoud; Magableh, Sami; Hadad, Rafiq; Nseer, Quteiba; Alshboul, Abdelkhaleg

    2015-01-01

    Introduction: Conjoined twins are identical twins joined in utero. It’s a rare phenomenon and present a unique challenge to obstetricians and pediatric surgeons. Conjoined twins are complex complication of monozygotic twinning, which is associated with high perinatal mortality. Case report: At our clinic complete anomaly scan was done, the patients was found to have monozygotic twins of 15 weeks gestation and carrying a conjoint twin. Our ultrasound revealed fully developed heads facing each ...

  15. Repulsive force of twin boundary on curved dislocations and its role on the yielding of twinned nanowires

    International Nuclear Information System (INIS)

    The effects of twin size and sample diameter on yield stress and surface dislocation emission in twinned metal nanowires deformed uniformly were studied using classical dislocation theory and the concept of image force from twin boundaries. This theoretical study is shown to quantitatively capture the linear increase in yield stress as twin size decreases in periodically twinned Au nanowires predicted by atomistic simulations. The implication of this model as a yield criterion for realistic metal nanostructures with nanoscale growth twins is discussed.

  16. Identical twins with lumbosacral lipomyelomeningocele.

    Science.gov (United States)

    Hanaei, Sara; Nejat, Farideh; Mortazavi, Abolghasem; Habibi, Zohreh; Esmaeili, Arash; El Khashab, Mostafa

    2015-01-01

    Lipomyelomeningocele, a congenital spine defect, is presented as skin-covered lipomatous tissue that attaches to the cord in different ways according to its subtypes. Unlike other types of neural tube defects, the exact cause of this birth defect has not been confirmed yet, but it is proposed to be a multifactorial disease with involvement of both genetic and environmental factors. The authors describe identical twins with lipomyelomeningocele of the same subtype and location without any familial history of similar abnormality. Therefore, the same genetic and/or environmental risk factors could have played a part in their condition. PMID:25396701

  17. Ectodermal dysplasia in identical twins

    Directory of Open Access Journals (Sweden)

    Gurkar Haraswarupa Puttaraju

    2013-01-01

    Full Text Available Hereditary hypohidrotic ectodermal dysplasia (HED is typically inherited as an X-linked recessive trait, characterized by deformity of at least two or more of the ectodermal structures - hair, teeth, nails and sweat glands. Two cases of hereditary HED involving identical male twins, is being documented for the rarity of its occurrence with special attention given to genetics, pathophysiology, clinical, intraoral manifestations and to the methods to improve the masticatory function, the facial esthetics and psychology of patients affected by this disease.

  18. [Blau syndrome in monozygotic twins].

    Science.gov (United States)

    Milman, Nils; Hansen, Annette; van Overeem Hansen, Thomas; Byg, Keld-Erik; Nielsen, Ole Haagen

    2006-10-16

    This case report describes Blau syndrome in monozygotic twins. The disease ran an identical course in both patients, starting with a maculopapulous exanthema at one year of age. Skin biopsies showed epithelioid cell granulomas with multinucleated giant cells. Shortly after arthritis and periarticular swelling developed and uveitis appeared at 8 years of age. Treatment consisted of prednisolone and methotrexate, and from 18 years of age of infliximab, with good effect. DNA analysis showed de novo R334W mutation in the CARD15 gene. The patients have now been followed for 19 years and are in good clinical condition. PMID:17069729

  19. Twin-Foucault imaging method

    Science.gov (United States)

    Harada, Ken

    2012-02-01

    A method of Lorentz electron microscopy, which enables observation two Foucault images simultaneously by using an electron biprism instead of an objective aperture, was developed. The electron biprism is installed between two electron beams deflected by 180° magnetic domains. Potential applied to the biprism deflects the two electron beams further, and two Foucault images with reversed contrast are then obtained in one visual field. The twin Foucault images are able to extract the magnetic domain structures and to reconstruct an ordinary electron micrograph. The developed Foucault method was demonstrated with a 180° domain structure of manganite La0.825Sr0.175MnO3.

  20. Twin Studies of Atopic Dermatitis

    DEFF Research Database (Denmark)

    Elmose, Camilla; Thomsen, Simon Francis

    2015-01-01

    about filaggrin and its role in the atopic march and provide suggestions for future research in this area. Methods. We identified all twin studies (published after 1970) that have calculated the concordance rate and/or the heritability of AD, or the genetic and environmental correlations between AD and...... around 85% explained by genetic pleiotropy. Conclusions. Genetic factors account for most of the variability in AD susceptibility and for the association between AD and asthma. Controversy remains as to whether the atopic diseases are causally related or whether they are diverse clinical manifestations...

  1. Effect of excess noise on continuous variable entanglement sudden death and Gaussian quantum discord

    Institute of Scientific and Technical Information of China (English)

    Su Xiao-Long

    2013-01-01

    A symmetric two-mode Gaussian entangled state is used to investigate the effect of excess noise on entanglement sudden death and Gaussian quantum discord with continuous variables.The results show that the excess noise in the channel can lead to entanglement sudden death of a symmetric two-mode Gaussian entangled state,while Gaussian quantum discord never vanishes.As a practical application,the security of a quantum key distribution (QKD) scheme based on a symmetric two-mode Gaussian entangled state against collective Gaussian attacks is analyzed.The calculation results show that the secret key cannot be distilled when entanglement vanishes and only quantum discord exists in such a QKD scheme.

  2. NOTE: Haemodynamic resistance model of monochorionic twin pregnancies complicated by acardiac twinning

    Science.gov (United States)

    Umur, Asli; van Gemert, Martin J. C.; van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; Nikkels, Peter G. J.

    2004-07-01

    An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauterine or neonatally in about 50% of the cases due to congestive heart failure, polyhydramnios and prematurity. Because the pathophysiology of this pregnancy is currently incompletely understood, we modified our previous haemodynamic model of monochorionic twins connected by placental vascular anastomoses to include the analysis of acardiac twin pregnancies. We incorporated the fetoplacental circulation as a resistance circuit and used the fetal umbilical flow that perfuses the body to define fetal growth, rather than the placental flow as done previously. Using this modified model, we predicted that the pump twin has excess blood volume and increased mean arterial blood pressure compared to those in the acardiac twin. Placental perfusion of the acardiac twin is significantly reduced compared to normal, as a consequence of an increased venous pressure, possibly implying reduced acardiac placental growth. In conclusion, the haemodynamic analysis may contribute to an increased knowledge of the pathophysiologic consequences of an acardiac body mass for the pump twin.

  3. Haemodynamic resistance model of monochorionic twin pregnancies complicated by acardiac twinning

    International Nuclear Information System (INIS)

    An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauterine or neonatally in about 50% of the cases due to congestive heart failure, polyhydramnios and prematurity. Because the pathophysiology of this pregnancy is currently incompletely understood, we modified our previous haemodynamic model of monochorionic twins connected by placental vascular anastomoses to include the analysis of acardiac twin pregnancies. We incorporated the fetoplacental circulation as a resistance circuit and used the fetal umbilical flow that perfuses the body to define fetal growth, rather than the placental flow as done previously. Using this modified model, we predicted that the pump twin has excess blood volume and increased mean arterial blood pressure compared to those in the acardiac twin. Placental perfusion of the acardiac twin is significantly reduced compared to normal, as a consequence of an increased venous pressure, possibly implying reduced acardiac placental growth. In conclusion, the haemodynamic analysis may contribute to an increased knowledge of the pathophysiologic consequences of an acardiac body mass for the pump twin. (note)

  4. Haemodynamic resistance model of monochorionic twin pregnancies complicated by acardiac twinning

    Energy Technology Data Exchange (ETDEWEB)

    Umur, Asli [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam(Netherlands); Gemert, Martin J C van [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Wijngaard, Jeroen P H M van den [Laser Center and Department of Obstetrics and Gynecology, Academic Medical Center, University of Amsterdam, Amsterdam (Netherlands); Ross, Michael G [Department of Obstetrics and Gynecology, Harbor University of California-Los Angeles Medical Center, Torrence, CA 9050 (United States); Nikkels, Peter G J [Department of Pathology, University Medical Center, Utrecht (Netherlands)

    2004-07-21

    An acardiac twin is a severely malformed monochorionic twin fetus that lacks most organs, particularly a heart. It grows during pregnancy, because it is perfused by its developmentally normal co-twin (called the pump twin) via a set of placental arterioarterial and venovenous anastomoses. The pump twin dies intrauterine or neonatally in about 50% of the cases due to congestive heart failure, polyhydramnios and prematurity. Because the pathophysiology of this pregnancy is currently incompletely understood, we modified our previous haemodynamic model of monochorionic twins connected by placental vascular anastomoses to include the analysis of acardiac twin pregnancies. We incorporated the fetoplacental circulation as a resistance circuit and used the fetal umbilical flow that perfuses the body to define fetal growth, rather than the placental flow as done previously. Using this modified model, we predicted that the pump twin has excess blood volume and increased mean arterial blood pressure compared to those in the acardiac twin. Placental perfusion of the acardiac twin is significantly reduced compared to normal, as a consequence of an increased venous pressure, possibly implying reduced acardiac placental growth. In conclusion, the haemodynamic analysis may contribute to an increased knowledge of the pathophysiologic consequences of an acardiac body mass for the pump twin. (note)

  5. Ocular findings in conjoined (Siamese) twins.

    Science.gov (United States)

    Mansour, A M; Mansour, N; Rosenberg, H S

    1991-01-01

    Conjoined twinning is a rare form of congenital anomaly. The ocular findings in six sets of conjoined twins as well as those reported elsewhere include abnormal optic nerve decussation, pseudosynophthalmos, microphthalmia, abnormal eyelids, orbital encephalocele, occipital encephalocele, and eyelid coloboma. These findings are interpreted as due to deformations from appositional fusion-related factors or malformations from developmental factors. PMID:1955960

  6. Cord entanglement in monoamniotic twin pregnancies

    DEFF Research Database (Denmark)

    Lyndrup, J; Schouenborg, Lars Øland

    1987-01-01

    Monoamniotic twin pregnancy involves a heavy risk of fatal umbilical cord entanglement. Two cases are reported. In the first case, both twins were found dead in the 36th week, and the monoamnionicity was recognized at birth. In the second case, the monoamnionicity was discovered during an...

  7. Ionospheric Response to Traveling Convection Twin Vortices

    OpenAIRE

    Schunk, Robert W.; Zhu, Lie; Sojka, Jan Josef

    1994-01-01

    Traveling convection twin vortices have been observed for several years. At ionospheric altitudes, the twin vortices correspond to spatially localized, transient structures embedded in a large‐scale background convection pattern. The convection vortices are typically observed in the morning and evening regions. They are aligned predominantly in the east‐west direction and have a horizontal extent of from 500–1000 km....

  8. The anaesthetic management of conjoined twins.

    Science.gov (United States)

    Stuart, Grant M; Black, Ann E; Howard, Richard F

    2015-10-01

    The management of anaesthesia for conjoined twins poses unique anatomical, physiological and logistic challenges. Although many possible configurations of union exist and each is unique, we describe the principles of anaesthesia for conjoined twins drawing on our institutional experience of managing 26 sets for a variety of procedures including separation. PMID:26382261

  9. Intrafetal alcohol ablation of an acardiac twin

    Directory of Open Access Journals (Sweden)

    Zahar Azuar Zakaria

    2016-07-01

    Full Text Available The twin reverse arterial perfusion (TRAP sequence is a rare but serious complication of mono-chorionic multiple pregnancies in which the affected twin is reversely perfused from the healthy co-twin. The unaffected twin is at risk of cardiac de-compensation or complication related to polyhydramnios, preterm pre-labour rupture of membrane and preterm delivery. When the risk to the healthy fetus increases significantly, the management is to occlude the circulation to the acardiac twin. Here we report a case successfully managed with intra-fetal alcohol ablation at the mid-trimester. [Int J Reprod Contracept Obstet Gynecol 2016; 5(7.000: 2421-2424

  10. Twins in Ancient Greece: a synopsis.

    Science.gov (United States)

    Malamitsi-Puchner, Ariadne

    2016-01-01

    This brief outline associates twins with several aspects of life in Ancient Greece. In Greek mythology twins caused ambivalent reactions and were believed to have ambivalent feelings for each other. Very often, they were viewed as the representatives of the dualistic nature of the universe. Heteropaternal superfecundation, which dominates in ancient myths, explains on one hand, the god-like qualities and, on the other hand, the mortal nature of many twins. An assumption is presented that legends referring to twins might reflect the territorial expansions of Ancient Greeks in Northern Mediterranean, around the Black Sea, in Asia Minor, as well as North East Africa. In conclusion, in Greek antiquity, twins have been used as transitional figures between myth and reality. PMID:26135766

  11. Comparison of quantum discord and relative entropy in some bipartite quantum systems

    Science.gov (United States)

    Mahdian, M.; Arjmandi, M. B.

    2016-04-01

    The study of quantum correlations in high-dimensional bipartite systems is crucial for the development of quantum computing. We propose relative entropy as a distance measure of correlations may be measured by means of the distance from the quantum state to the closest classical-classical state. In particular, we establish relations between relative entropy and quantum discord quantifiers obtained by means of orthogonal projection measurements. We show that for symmetrical X-states density matrices the quantum discord is equal to relative entropy. At the end of paper, various examples of X-states such as two-qubit and qubit-qutrit have been demonstrated.

  12. Entanglement and discord in two-mode Gaussian open quantum systems

    International Nuclear Information System (INIS)

    In the framework of the theory of open systems, we give a description of quantum entanglement and quantum discord for two noninteracting modes embedded in a thermal environment. We describe the evolution of entanglement in terms of the covariance matrix for Gaussian input states. For all values of the temperature of the thermal reservoir, an initial separable squeezed thermal state remains separable for all times. In the case of an entangled initial squeezed thermal state, entanglement suppression (entanglement sudden death) takes place for nonzero temperatures of the environment. The Gaussian quantum discord, which is a measure of all quantum correlations in the state, including entanglement, decays asymptotically in time.

  13. Quantum Discord and Entanglement of Quasi-Werner States based on Entangled Coherent States

    CERN Document Server

    Mishra, Manoj K; Prakash, Hari

    2012-01-01

    Present work is an attempt to compare quantum discord and quantum entanglement of Werner states formed with the four bipartite entangled coherent states (ECS) used recently for quantum teleportation of a qubit encoded in superposed coherent state. Out of these, two based on maximally ECS are exactly similar to the perfect Werner state, while the rest two, based on non-maximally ECS, which are called quasi-Werner states behave in somewhat different ways and their quantum discord and entanglement depends on the coherent amplitude and the measurement basis.

  14. Tomographic causal analysis of two-qubit states and tomographic discord

    International Nuclear Information System (INIS)

    We study a behavior of two-qubit states subject to tomographic measurement. In this Letter we propose a novel approach to definition of asymmetry in quantum bipartite state based on its tomographic Shannon entropies. We consider two types of measurement bases: the first is one that diagonalizes density matrices of subsystems and is used in a definition of tomographic discord, and the second is one that maximizes Shannon mutual information and relates to symmetrical form quantum discord. We show how these approaches relate to each other and then implement them to the different classes of two-qubit states. Consequently, new subclasses of X-states are revealed.

  15. A statistical analysis of the influence of microstructure and twin–twin junctions on twin nucleation and twin growth in Zr

    International Nuclear Information System (INIS)

    The purpose of the present work is (1) to study the statistical relevance of twin–twin junctions and (2) to study statistically the influence of twin–twin junctions and microstructure on nucleation and growth of twins in h.c.p. materials. A new automated twin recognition technique has been developed and is used to extract statistics from EBSD scans of high purity clock-rolled zirconium specimens loaded along the through-thickness and one of the in-plane directions. The technique allows for recognition of tensile and compressive twin systems within each individual grain. The ten possible twin–twin junction types that may occur in Zr between first generation twins are introduced as well as their associated frequencies in cases of through-thickness and in-plane compression. The present study shows that twin–twin junctions between twins belonging to the most active twinning modes are statistically relevant. It is also shown that twin–twin junctions hinder twin growth. In agreement with previous studies, it is found that irrespective of the loading direction and twin mode, both grain size and crystallographic orientation largely influence the propensity of grains for twin activation. However, the study suggests large differences in nucleation and growth mechanisms for each twinning mode

  16. Highlights from the 15th International Congress of Twin Studies/Twin Research: Differentiating MZ Co-twins Via SNPs; Mistaken Infant Twin-Singleton Hospital Registration; Narcolepsy With Cataplexy; Hearing Loss and Language Learning/Media Mentions: Broadway Musical Recalls Conjoined Hilton Twins; High Fashion Pair; Twins Turn 102; Insights From a Conjoined Twin Survivor.

    Science.gov (United States)

    Segal, Nancy L

    2015-02-01

    Highlights from the 15th International Congress of Twin Studies are presented. The congress was held November 16-19, 2014 in Budapest, Hungary. This report is followed by summaries of research addressing the differentiation of MZ co-twins by single nucleotide polymorphisms (SNPs), an unusual error in infant twin-singleton hospital registration, twins with childhood-onset narcolepsy with cataplexy, and the parenting effects of hearing loss in one co-twin. Media interest in twins covers a new Broadway musical based on the conjoined twins Violet and Daisy Hilton, male twins becoming famous in fashion, twins who turned 102 and unique insights from a conjoined twin survivor. This article is dedicated to the memory of Elizabeth (Liz) Hamel, DZA twin who met her co-twin for the first time at age seventy-eight years. Liz and her co-twin, Ann Hunt, are listed in the 2015 Guinness Book of Records as the longest separated twins in the world. PMID:25662422

  17. Is Marital Discord Taxonic and Can Taxonic Status Be Assessed Reliably? Results from a National, Representative Sample of Married Couples

    Science.gov (United States)

    Whisman, Mark A.; Beach, Steven R. H.; Snyder, Douglas K.

    2008-01-01

    Addressing potential weaknesses in an earlier investigation, the authors examined the latent structure of marital discord using 4 product indicators from the Marital Satisfaction Inventory-Revised (Snyder, 1997) in a representative sample of community couples (N = 1,020). Results from 3 taxometric procedures suggested that marital discord is…

  18. Generation of Entanglement, Measure of Multipartite Entanglement in Fermionic Systems and Quantum Discord in Bipartite Systems and Heisenberg Chains

    OpenAIRE

    Lari, Behzad

    2011-01-01

    This is a thesis submitted to university of Pune, India, for the Ph.D. degree. This work deals with entanglement production in two qubit, two qutrit and three qubit systems, entanglement in indistinguishable fermionic systems, quantum discord in a Heisenberg chain and geometric measure of quantum discord in an arbitrary state of a bipartite quantum system.

  19. Controlling quantum discord dynamics in cavity QED systems by applying a classical driving field with phase decoherence

    International Nuclear Information System (INIS)

    We investigate a two-level atom interacting with a quantized cavity field and a classical driving field in the presence of phase decoherence and find that a stationary quantum discord can arise in the interaction of the atom and cavity field as the time turns to infinity. We also find that the stationary quantum discord can be increased by applying a classical driving field. Furthermore, we explore the quantum discord dynamics of two identical non-interacting two-level atoms independently interacting with a quantized cavity field and a classical driving field in the presence of phase decoherence. Results show that the quantum discord between two atoms is more robust than entanglement under phase decoherence and the classical driving field can help to improve the amount of quantum discord of the two atoms. (general)

  20. NOTE: Thrombosis of anastomoses may affect the staging sequence of twin twin transfusion syndrome

    Science.gov (United States)

    van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; van Gemert, Martin J. C.

    2008-03-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. Supported in part by the European Community Euro-twin-2-twin project (JPHMvdW) and by the National Institutes of Health, grant HL40899 (MGR).

  1. Rare Complications with Monochorionic Twins: Ultrasonography and Pathology Correlations

    Energy Technology Data Exchange (ETDEWEB)

    Song, Mi Jin [Cheil General Hospital and Women' s Healthcare Center, Kwandong University College of Medicine, Seoul (Korea, Republic of)

    2009-12-15

    We reviewed the sonographic features of rare complications with monochorionic twins and we correlated these features with the pathologic findings. The complications, including the twin reversed arterial perfusion sequence, the twin embolization syndrome, the conjoined twins and umbilical cord entanglement. A better understanding of these complications can aid making an accurate prenatal diagnosis and predicting the fetal outcome

  2. Successful Separation of Omphalopagus Twins: A Case Report

    Directory of Open Access Journals (Sweden)

    Prashant S Patil

    2016-01-01

    Full Text Available Omphalopagus twins are conjoined twins sharing part of gastrointestinal system and abdominal wall. These types of twins have best chances of survival if successfully separated. We report a case of successfully separated omphalopagus twins at day six of life.

  3. Successful Separation of Omphalopagus Twins: A Case Report.

    Science.gov (United States)

    Patil, Prashant S; Kothari, Paras; Gupta, Abhaya; Kekre, Geeta; Dikshit, K V; Kamble, Ravi; Deshmukh, Shahaji

    2016-01-01

    Omphalopagus twins are conjoined twins sharing part of gastrointestinal system and abdominal wall. These types of twins have best chances of survival if successfully separated. We report a case of successfully separated omphalopagus twins at day six of life. PMID:26793597

  4. Rare Complications with Monochorionic Twins: Ultrasonography and Pathology Correlations

    International Nuclear Information System (INIS)

    We reviewed the sonographic features of rare complications with monochorionic twins and we correlated these features with the pathologic findings. The complications, including the twin reversed arterial perfusion sequence, the twin embolization syndrome, the conjoined twins and umbilical cord entanglement. A better understanding of these complications can aid making an accurate prenatal diagnosis and predicting the fetal outcome

  5. Anxiety Disorders and Latinos: The Role of Family Cohesion and Family Discord

    Science.gov (United States)

    Priest, Jacob B.; Denton, Wayne

    2012-01-01

    Family cohesion has shown to be associated with lower psychological distress and other risk behaviors for Latinos, but little is known about the relationship of family cohesion, family discord, and anxiety disorders. Using data from the National Latino and Asian American Study (n = 2,554), this study examines the relationship between family…

  6. Divergent Perspectives on Language-Discordant Mobile Medical Professionals' Communication with Colleagues: An Exploratory Study

    Science.gov (United States)

    Gasiorek, Jessica; van de Poel, Kris

    2012-01-01

    Little is known about how language-discordant mobile medical professionals (MMPs), defined as doctors who work in foreign countries, cultures, and languages, interact with their colleagues. The number of MMPs around the world is growing, and their interactions with colleagues have direct consequences for both patients' health and their own…

  7. Recalled Explanations for Adolescent Girls' Engagement in Age-Discordant Sexual Relationships.

    Science.gov (United States)

    Cort, Natalie A; Senn, Theresa E; Carey, Michael P; Braksmajer, Amy

    2016-06-01

    Age-discordant sexual relationships are associated with negative sexual health outcomes for adolescent females. We were particularly interested in females' motivations for engaging in these relationships, and in contextual factors that increase receptivity to age-discordant relationships in the United States (U.S.). However, recent research addressing this topic in the U.S. has been sparse. To address this gap in the literature, we recruited 15 women (Mdn age = 26 years; 93 % African American) from an urban, publicly funded sexually transmitted disease clinic to qualitative interviews. Reasons given by women for their involvement in age-discordant sexual relationships as adolescents included: (a) desire for an actively engaged father figure, (b) to obtain material support, (c) to escape from a troubled home life, and (d) to express independence and maturity. Thus, familial, economic, and developmental factors motivate socioeconomically disadvantaged adolescent females to enter into age-discordant sexual relationships. Efforts to reduce females' participation in these relationships will need to address socioeconomic vulnerability and family relationships. PMID:26662265

  8. Phenotype-genotype discordance in congenital malformations with communication disorders resembling trisomy 18 (Edwards syndrome)

    OpenAIRE

    Pruszewicz, Antoni; Wiskirska-Woźnica, Bożena; Wojnowski, Waldemar; Czerniejewska, Hanna; Jackowska, Joanna; Jarmuż, Małgorzata; Szyfter, Krzysztof; Leszczyńska, Małgorzata

    2014-01-01

    Patient: Female, 6 Final Diagnosis: Phenotype-genotype discordance in congenital malformations with communication disorders resembling trisomy 18 (Edwards syndrome) Symptoms: — Medication: — Clinical Procedure: — Specialty: Otolaryngology Objective: Congenital defects Background: Communication process disorders are very frequent in rare cases of chromosomal aberrations (deletions, insertions, and trisomies) such as Down syndrome (trisomy 21), Turner syndrome, Edwards syndrome (trisomy 18), or...

  9. What predicts intention-behavior discordance? A review of the action control framework

    NARCIS (Netherlands)

    R.E. Rhodes; G.J. de Bruijn

    2013-01-01

    The physical activity intention-behavior gap is a focus of considerable research. The purpose of this article is to overview contemporary evidence for predictors of this intention-behavior discordance using the action control framework developed in our laboratories. We propose the hypothesis that in

  10. Identical twins with “mirror image” anisometropia and esotropia

    OpenAIRE

    Stanković-Babić Gordana; Vujanović Milena; Cekić Sonja

    2011-01-01

    Introduction. Identical twins account for 0.2% of the world population and 8% of all twins. A “mirror image” variation can be found in 25% of identical twins. Studies of twins assume a special place in human genetics due to the possibility of comparing genetic and other factors. We present two pairs of identical male twins with mirror-image astigmatism and esotropia. Case Outline. The first was a pair of twelve-year old identical twins with “mirror image” myopic astigmatism. The Twin 1 ...

  11. Calcite twin morphology : a low-temperature deformation geothermometer

    OpenAIRE

    Ferrill, David A.; Morris, Alan P.; Evans, Mark A; Burkhard, Martin; Groshong Jr., Richard H.; Onasch, Charles M.

    2005-01-01

    Twinning of the e-plane is the dominant crystal–plastic deformation mechanism in calcite deformed below about 400 °C. Calcite in a twin domain has a different crystallographic orientation from the host calcite grain. So-called thin twins appear as thin black lines when viewed parallel to the twin plane at 200–320× magnification under a petrographic microscope. Thick twins viewed in the same way have a microscopically visible width of twinned material between black lines. Calcite e-twin width ...

  12. Langevin's `Twin Paradox' paper revisited

    CERN Document Server

    Field, J H

    2008-01-01

    An in-depth and mathematically-detailed analysis of Langevin's popular 1911 article on the special theory of relativity is presented. For the reader's convenience, English translations of large parts of the original French text are given. The self-contradictory nature of many of Langevin's assertions is pointed out. Of special interest is the analysis of the exchange of light signals between the travelling and stay-at-home twins in Langevin's thought experiment, in which antinomies are found in the conventional relativistic treatment. Their resolution shows that the physical basis of the differential aging effect in the experiment is not `length contraction', as in the conventional interpretation, but instead the application of the correct relative velocity transformation formula. The spurious nature of the correlated `length contraction' and `relativity of simultaneity' effects of conventional special relativity is also demonstrated. In consequence, an argument given, claiming to demonstrate that an upper li...

  13. Conjoined twins with a horseshoe kidney

    OpenAIRE

    M Modi; Kramer, L.

    2009-01-01

    Conjoined twins are rare variants of monozygotic twins. There are many types of conjoined twins, and they are usually classified at the point at which they are fused. Our patient fitted into a thoraco-omphalopagus type, where there was fusion of the thorax as well as mid-trunk [3]. The most common type of renal fusion anomaly is the horseshoe kidney. It consists of 2 distinct functioning kidneys on each side of the midline, and they are more likely to be connected at the lower poles [4]. We d...

  14. Undiagnosed xiphopagus twins: a perinatal malady

    OpenAIRE

    Gowri Dorairajan

    2012-01-01

    Conjoined twins are a very rare entity. It is associated with poor survival rate in the presence of vital organ sharing. The entity can be diagnosed as early as the first trimester. A conjoined twin diagnosed late in labor is a malady with high perinatal mortality and maternal morbidity. We present one such case of xiphopagus twins. The management of a case diagnosed late in labor can be very challenging. Such obstetric challenges can be avoided by a meticulous early scan with a high index of...

  15. Strong crystal size effect on deformation twinning

    DEFF Research Database (Denmark)

    Yu, Qian; Shan, Zhi-Wei; Li, Ju;

    2010-01-01

    find that the stress required for deformation twinning increases drastically with decreasing sample size of a titanium alloy single crystal7, 8, until the sample size is reduced to one micrometre, below which the deformation twinning is entirely replaced by less correlated, ordinary dislocation...... plasticity. Accompanying the transition in deformation mechanism, the maximum flow stress of the submicrometre-sized pillars was observed to saturate at a value close to titanium’s ideal strength9, 10. We develop a ‘stimulated slip’ model to explain the strong size dependence of deformation twinning. The...

  16. Undiagnosed xiphopagus twins: a perinatal malady

    Directory of Open Access Journals (Sweden)

    Gowri Dorairajan

    2012-02-01

    Full Text Available Conjoined twins are a very rare entity. It is associated with poor survival rate in the presence of vital organ sharing. The entity can be diagnosed as early as the first trimester. A conjoined twin diagnosed late in labor is a malady with high perinatal mortality and maternal morbidity. We present one such case of xiphopagus twins. The management of a case diagnosed late in labor can be very challenging. Such obstetric challenges can be avoided by a meticulous early scan with a high index of suspicion, especially in the absence of separating membrane while scanning multiple pregnancies.

  17. On Radar Time and the Twin `Paradox'

    CERN Document Server

    Dolby, C E; Dolby, Carl E.; Gull, Stephen F.

    2001-01-01

    In this paper we apply the concept of radar time (popularised by Bondi in his work on k-calculus) to the well-known relativistic twin `paradox'. Radar time is used to define hypersurfaces of simultaneity for a class of travelling twins, from the `Immediate Turn-around' case, through the `Gradual Turn-around' case, to the `Uniformly Accelerating' case. We show that this definition of simultaneity is independent of choice of coordinates, and assigns a unique time to any event (with which the travelling twin can send and receive signals), resolving some common misconceptions.

  18. Twin heart with a fused atria and separate ventricles in conjoined twins

    OpenAIRE

    Ambar Sameer; Halkati Prabhu; Patted Suresh; Yavagal S

    2010-01-01

    One of the most interesting congenital malformations is that of conjoined twins. We report echocardiographic features of twin heart in dicephalus, tribrachius, dispinous, thoracoomphalopagus twin. It showed two hearts fused at atrial level. Right-sided heart had single atrial chamber with a single ventricle. A single great vessel, aorta, originated from it. Left-sided heart was well developed with two atria and two ventricles. There was a small mid muscular ventricular septal defect and a sma...

  19. Parasitic twin with gastroschisis is one of the rarest variant of conjoined twins: a case report.

    Science.gov (United States)

    Baskaran, D; Aleem, M A; Ravi, R

    2015-04-01

    We report a case of parasitic twin or incomplete or heteropagus twining of extra portions of a pelvis, lower and upper limbs, duplication of genitalia and herniation of intestinal tract with spleen-variant of conjoined twinning (CT) consistent with fusion of two embryos followed by resorption of the caudal half of one of them, resulting in a normal male baby with the upper half of a male parasitic twin fused to his chest. PMID:25972657

  20. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.;

    2008-01-01

    In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...... pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine...

  1. A case report: The role of amnioreduction plus septostomy in management of twin twin transfusion syndrome

    OpenAIRE

    GÜRBÜZ, Ayşe; Berna, HALİLOĞLU; Aydın, GÜRBÜZ; Öztürk, GAZİYİZ Göknur

    2004-01-01

    We have reported our experience with intentional puncture of the intervening membrane (septostomy)in combination with amnioreduction in a severe twin to twin transfusion syndrome case. One of the fetuses (in the form of stuck twin) had anydramnios and nonvisible bladder. The other fetuse had anyhydramnios and enlarged bladder. We support thatamniotic septostomy plus amnioreduction is a basic and promising method for the management of this syndrome.

  2. Twin-Twin Transfusion Syndrome Presenting as Polyhydramnios in Both Fetuses Secondary to Spontaneous Microseptostomy

    OpenAIRE

    David N. Hackney; Nahla Khalek; Julie Moldenhauer; Tulin Ozcan

    2013-01-01

    The presence of polyhydramnios and oligohydramnios is pathognomonic for twin–twin transfusion syndrome (TTTS). However, polyhydramnios of both twins can exist in TTTS in the setting of a septostomy of the dividing membrane. In prior reported cases of dual polyhydramnios TTTS, the septostomy was identified through either ultrasound or fetoscopy thus helping to establish the diagnosis of TTTS with an unusual presentation. The presented case is a set of monochorionic, diamniotic twins who presen...

  3. Hirschsprung’s disease in twin to twin transfusion syndrome: A case report

    OpenAIRE

    Park, Hye Won; Cho, Min Jeng; Kim, Wook Youn; Kwak, Byung Ok; Kim, Min Hee

    2014-01-01

    Twin to twin transfusion syndrome (TTTS) is caused by aberrant vascular connections between infant twins and results in high morbidity and mortality in the perinatal period. In donor infants with TTTS and symptoms of intestinal obstruction, small-bowel lesions have been reported in most cases. We report on a 33+6 gestational wk donor infant with TTTS who had intermittent obstructive episodes, including delayed meconium passage and colonic dilatation on abdominal X-ray. The diagnosis of Hirsch...

  4. Cephalopagus conjoined twins in a leopard cat (Prionailurus bengalensis).

    Science.gov (United States)

    Kompanje, Erwin J O; Hermans, John J

    2008-01-01

    Case reports of conjoined twins ("Siamese twins") in wild mammals are scarce. Most published reports of conjoined twins in mammals concern cases in man and domestic mammals. This article describes a case of cephalopagus conjoined twins in a leopard cat (Prionailurus bengalensis) collected on the island of Sumatra, Indonesia, in the period 1873-76. A review of known cases of conjoined twinning in wild mammals is given. PMID:18263837

  5. Thoraco-omphalopagus twins: different perinatal circumstances, different outcome

    OpenAIRE

    Piaseczna-Piotrowska, Anna; Chilarski, Andrzej; Krajewski, Wojciech; Godlewska-Tarka, Joanna

    2010-01-01

    Two pairs of omphalopagus twins were encountered at the Polish Mother's Health Institution in Lodz, Poland during the past 15 years. In the first set the prenatal diagnosis was not established and the delivery of the twins in a regional hospital was a complete surprise. Both babies died. In the second case the conjoined twins were diagnosed prenatally, surgical separation was successful, and both twins survived. The prenatal identification of conjoined twins is of cardinal importance for the ...

  6. Concurrent Neonatal Proteus mirabilis Infection in Dizygotic Twins

    OpenAIRE

    Sung, Lillian; MacDonald, Noni E; Hutchison, James S

    1999-01-01

    A case of concomitant infection with Proteus mirabilis in dizygotic twin neonates is presented. The first twin presented with meningitis and septic shock at eight days of age and subsequently died. An investigation of the asymptomatic second twin revealed a urinary tract infection that resolved with antimicrobial therapy. It is recommend that when infection with this virulent organism is diagnosed in one twin, the second twin should be fully evaluated for sepsis and empirical antimicrobial th...

  7. Twinning in muskox and the cytogenetic investigation of a freemartin

    OpenAIRE

    N. J. Reindl; L. C. Buoen; T. Q. Zhang

    1993-01-01

    The occurrence of twinning has been documented for muskox in both wild and captive populations. Of two known captive twin births only one set survived beyond 120 days. In both cases the twins were male-female pairs and both females showed abnormal sexual development. Two sets of stillborn twins have also been recorded. All four stillborn fetuses were female and none showed anomalies of the reproductive tract upon post-mortem examination. Blood cultures from the surviving male and female twins...

  8. Birth weight for gestational age among Flemish twin population

    OpenAIRE

    Doom, E.C.G.; Delbaere, I.; Martens, G.; Temmerman, M.

    2012-01-01

    Objective: The aim of this study was to develop birth weight references for twins. Mean birth weights of individual twins are lower than those of singletons, hence singleton birth weight curves may not be suitable to assess twin birth weights. Study design: Twin birth weight curves were developed according to gestational age, gender, parity and mode of conception. The curves are based on population-based data of 40,494 twins born in Flanders, Belgium between 1987 and 2007. Results: A differen...

  9. Microscopic particles in two fractions of fresh cerebrospinal fluid in twins with schizophrenia or bipolar disorder and in healthy controls.

    Directory of Open Access Journals (Sweden)

    Viktoria Johansson

    Full Text Available BACKGROUND: Using scanning electron microscopy, microscopic structures have been identified in fresh cerebrospinal fluid (CSF in patients with schizophrenia and bipolar disorder, but only rarely in control subjects. However, it has not been determined whether these microscopic particles represent state or trait markers, i.e. if their presence is related to clinical manifestations of the disease or if they also can be found in as yet asymptomatic individuals with a genetic liability. This question can be addressed by studying twins discordant or concordant for schizophrenia or bipolar disorder. METHODOLOGY/PRINCIPAL FINDINGS: We investigated microscopic structures in CSF in 102 individuals: 21 monozygotic and 16 dizygotic twins affected or not affected with schizophrenia, schizoaffective disorder or bipolar disorder and in 65 healthy singleton controls. A first and a second fraction of CSF was freshly applied on filters and examined by scanning electron microscopy technique. Spherical particles with lipid appearance averaging between 0.1 to 8.0 µm in diameter were detected in the center of the filter as well as located in the margins of larger aggregates binding in a viscous state. Structures were found in 12 of 17 probands, 5 of 12 healthy co-twins and 3 of 73 healthy controls. Thus, a positive microscopic finding significantly increased the likelihood of belonging to the proband group (OR=48, 95% CL: 8.2-550, p<0.0001 and the co-twin-group (OR=16, 95% CL: 2.0-218, p=0.006. Age, sex, history of alcohol abuse or anxiety syndrome, somatic disorder and markers of acute inflammatory activity did not account for group differences; nor did exposure to psychotropic medication. CONCLUSION: Presence of microscopic particles in CSF may possibly reflect trait dependent genetic or environmental vulnerability in patients with schizophrenia, schizoaffective disorder or bipolar disorder.

  10. Twin boundary energy and characterization of charge redistribution near the twin boundaries of cupperate superconductors

    International Nuclear Information System (INIS)

    Highlights: • Ab initio simulation for twin boundary energy in YBCO system for the 1st time. • Study of the twin boundary energy variation versus the inserted strain. • Proportionality of twin lamella width by the inserted strain. • Local charge transfer and charge redistribution on the twin planes. • Total DOSs for the twined system at Fermi level is higher than the untwined one. • This explain the effect of twin boundaries in agreement with experimental data. - Abstract: Ab-initio calculations under general gradient approximation have been employed for the first time to find out twin boundary energy, γ, in twined YBCO systems. Despite a vast discrepancy in reported experimental values, our results show that the γ value falls in the range of 40–85 mJ/m2. On the other hand, functional form of γ versus inserted strains shows that the mean value for the twin width lamella would tend to approach zero as the strain goes to zero. We have also investigated the local charge transfer and the modification of the electronic states of the basal and twin planes in YBCO, because the charge redistribution at interfaces can modify transport across the grains considerably and determine the applicability of high-Tc superconductors in the electronic applications. The total density of electronic states at the Fermi level for the twined system is enhanced in comparison with the untwined one. Our results explain the influence of twin boundaries in superconductive properties of YBCO, in experimental situations

  11. Quantum discord and classical correlation signatures of mobility edges in one-dimensional aperiodic single-electron systems

    International Nuclear Information System (INIS)

    We investigate numerically the quantum discord and the classical correlation in a one-dimensional slowly varying potential model and a one-dimensional Soukoulis–Economou ones, respectively. There are well-defined mobility edges in the slowly varying potential model, while there are discrepancies on mobility edges in the Soukoulis–Economou ones. In the slowly varying potential model, we find that extended and localized states can be distinguished by both the quantum discord and the classical correlation. There are sharp transitions in the quantum discord and the classical correlation at mobility edges. Based on these, we study “mobility edges” in the Soukoulis–Economou model using the quantum discord and the classical correlation, which gives another perspectives for these “mobility edges”. All these provide us good quantities, i.e., the quantum discord and the classical correlation, to reflect mobility edges in these one-dimensional aperiodic single-electron systems. Moreover, our studies propose a consistent interpretation of the discrepancies between previous numerical results about the Soukoulis–Economou model. -- Highlights: ► Quantum discord and classical correlation can signal mobility edges in two models. ► An interpretation for mobility edges in the Soukoulis–Economou model is proposed. ► Quantum discord and classical correlation can reflect well localization properties.

  12. Twin nucleation and migration in FeCr single crystals

    International Nuclear Information System (INIS)

    Tension and compression experiments were conducted on body-centered cubic Fe -47.8 at pct. Cr single crystals. The critical resolved shear stress (CRSS) magnitudes for slip nucleation, twin nucleation and twin migration were established. We show that the nucleation of slip occurs at a CRSS of about 88 MPa, while twinning nucleates at a CRSS of about 191 MPa with an associated load drop. Following twin nucleation, twin migration proceeds at a CRSS that is lower than the initiation stress (≈ 114–153 MPa). The experimental results of the nucleation stresses indicate that the Schmid law holds to a first approximation for the slip and twin nucleation cases, but to a lesser extent for twin migration particularly when considerable slip strains preceded twinning. The CRSSs were determined experimentally using digital image correlation (DIC) in conjunction with electron back scattering diffraction (EBSD). The DIC measurements enabled pinpointing the precise stress on the stress–strain curves where twins or slip were activated. The crystal orientations were obtained using EBSD and used to determine the activated twin and slip systems through trace analysis. - Highlights: ► Digital image correlation allows to capture slip/twin initiation for bcc FeCr. ► Crystal orientations from EBSD allow slip/twin system indexing. ► Nucleation of slip always precedes twinning. ► Twin growth is sustained with a lower stress than required for nucleation. ► Twin-slip interactions provide high hardening at the onset of plasticity.

  13. Severe anisometropic myopia in identical twins

    Directory of Open Access Journals (Sweden)

    Olukorede O. Adenuga

    2014-01-01

    Full Text Available High anisometropic myopia is a rare condition in twins. Genetic factors have been implicated in its development and there may be an association with vision-threatening complications. A pair of 11-year-old twins presented with poor distance vision in both eyes. Detailed ocular examination was performed including slit lamp examination, dilated funduscopy, cycloplegic refraction, keratometry and axial length measurement. The objective refraction was -6.50DS -2.00DC × 180 (right eye, -1.00DS (left eye for the first twin; -13.75DS -2.25DC × 180 (right eye, -0.50DS -0.75DC × 04 (left eye for the second twin. This case suggests an underlying genetic defect in the development of myopia.

  14. Severe anisometropic myopia in identical twins.

    Science.gov (United States)

    Adenuga, Olukorede O

    2014-01-01

    High anisometropic myopia is a rare condition in twins. Genetic factors have been implicated in its development and there may be an association with vision-threatening complications. A pair of 11-year-old twins presented with poor distance vision in both eyes. Detailed ocular examination was performed including slit lamp examination, dilated funduscopy, cycloplegic refraction, keratometry and axial length measurement. The objective refraction was -6.50 DS -2.00 DC × 180 (right eye), -1.00 DS (left eye) for the first twin; -13.75 DS -2.25 DC × 180 (right eye), -0.50 DS -0.75 DC × 04 (left eye) for the second twin. This case suggests an underlying genetic defect in the development of myopia. PMID:25100917

  15. Polycystic ovarian syndrome in identical twins.

    OpenAIRE

    Hutton, C.; Clark, F.

    1984-01-01

    Two 21-year-old female twins are described. They presented simultaneously with hirsutism and oligomenorrhoea. Investigation showed they had polycystic ovaries, they were identical and were not cases of post-pubertal adrenogenital syndrome.

  16. A twin paradox for 'clever' students

    CERN Document Server

    Ghosal, S K; Nepal, S; Das, Debarchana; Nepal, Saroj

    2005-01-01

    We discuss the twin paradox or the clock paradox under the small velocity approximation of special relativity. In this paper the traveller twin of the standard twin parable sets out with a non-relativistic speed for the trip leaving behind the stay-at-home one on earth and continues up to a distance and finally returns home with the same speed when the siblings can compare their ages or their initially synchronized wrist watches. The common knowledge that at small velocities the length contraction and time dilation effects of special relativity can be ignored so that the world becomes essentially classical, tends to lead to a paradox in connection with the twin problem, which a "clever" student eventually discovers. After discussing and resolving the issue, some more related paradoxes have been presented. The resolution of all these problems provides some additional insight into the century old paradox.

  17. Infantile Perineal Protrusion in Two Monochorionic Twins

    Directory of Open Access Journals (Sweden)

    Paola Cavicchioli

    2014-11-01

    Full Text Available Case Report - Two female monochorionic-monoamniotic twins showed the same kind of infantile perineal protrusion (IPP at birth. Lesions in both twins progressively healed until resolution in 6 weeks' time; none of the twins have manifested, till date, alvus disturbances. Discussion and Literature Review - A literature review numbers approximately 100 reports of IPP. This condition has been classically classified into three categories: congenital/familiar (i.e., female sex, positive parental history of IPP, acquired (mainly due to constipation, and associated with lichen sclerosus et atrophicus. Conclusions and Final Remarks - This case report describes, for the first time, the presence of IPP in monochorionic-monoamniotic twins, supporting the existence of hereditary/genetic factors in the developing of this condition.

  18. Micromechanics of twinning in a TWIP steel

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, K.M., E-mail: khandaker.rahman05@imperial.ac.uk [Department of Materials, Royal School of Mines, Imperial College London, Prince Consort Road, London SW7 2BP (United Kingdom); Jones, N.G. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Dye, D. [Department of Materials, Royal School of Mines, Imperial College London, Prince Consort Road, London SW7 2BP (United Kingdom)

    2015-05-21

    The deformation behaviour of a TWinning Induced Plasticity (TWIP) steel was studied at quasi-static strain rates using synchrotron X-ray diffraction. A {111} RD and {200} RD texture developed from the earliest stages of deformation, which could be reproduced using an elasto-plastic self consistent (EPSC) model. Evidence is found from multiple sources to suggest that twinning was occurring before macroscopic yielding. This included small deviations in the lattice strains, {111} intensity changes and peak width broadening all occurring below the macroscopic yield point. The accumulation of permanent deformation on sub-yield mechanical cycling of the material was found, which further supports the diffraction data. TEM revealed that fine deformation twins similar to those observed in heavily deformed samples formed during sub-yield cycling. It is concluded that twinning had occurred before macroscopic plastic deformation began, unlike the behaviour traditionally expected from hexagonal metals such as Mg.

  19. The Radiative Z2 Breaking Twin Higgs

    CERN Document Server

    Yu, Jiang-Hao

    2016-01-01

    In twin Higgs model, the Higgs boson mass is protected by a $Z_2$ symmetry. The $Z_2$ symmetry needs to be broken either explicitly or spontaneously to obtain misalignment between electroweak and new physics vacua. We propose a novel $Z_2$ breaking mechanism, in which the $Z_2$ is spontaneously broken by radiative corrections to the Higgs potential. Two twin Higgses with different vacua are needed, and vacuum misalignment is realized by opposite but comparable contributions from gauge and Yukawa interactions to the potential. Due to fully radiative symmetry breaking, the Higgs sector is completely determined by twin Higgs vacuum, Yukawa and gauge couplings. There are eight pseudo-Goldstone bosons: the Higgs boson, inert doublet Higgs, and three twin scalars. We show the 125 GeV Higgs mass and constraints from Higgs coupling measurements could be satisfied.

  20. Twin screw subsurface and surface multiphase pumps

    Energy Technology Data Exchange (ETDEWEB)

    Dass, P. [CAN-K GROUP OF COMPANIES, Edmonton, Alberta (Canada)

    2011-07-01

    A new subsurface twin screw multiphase pump has been developed to replace ESP and other artificial lift technologies. This technology has been under development for a few years, has been field tested and is now going for commercial applications. The subsurface twin screw technology consists of a pair of screws that do not touch and can be run with a top drive or submersible motor; and it carries a lot of benefits. This technology is easy to install and its low slippage makes it highly efficient with heavy oil. In addition twin screw multiphase pumps are capable of handling high viscosity fluids and thus their utilization can save water when used in thermal applications. It also induces savings of chemicals because asphaltenes do not break down easily as well as a reduction in SOR. The subsurface twin screw multiphase pump presented herein is an advanced technology which could be used in thermal applications.

  1. Thoracopagus conjoined twin: an unusual presentation

    Directory of Open Access Journals (Sweden)

    Rajesh Kumari

    2014-02-01

    Full Text Available Conjoined twins are among rare clinical conditions observed by obstetricians. Due to rare incidence of this condition there is general lack of knowledge among obstetricians, especially at primary care level which leads to missed diagnosis during antenatal period. The management of this condition is complex especially in cases where the diagnosis is not known before onset of labour. A 30 - year old Hindu lady was referred to us from other hospital with diagnosis of twin pregnancy and prolonged second stage of labour. Clinical examination revealed findings of ruptured uterus and foetal head of one baby and feet of second baby were outside the introitus. Emergency laparotomy was done which revealed conjoined twins. This article report clinical course of a thoracopagus conjoined twin. The relevant literature is also reviewed. [Int J Reprod Contracept Obstet Gynecol 2014; 3(1.000: 245-247

  2. Conjoined twins with a horseshoe kidney

    Directory of Open Access Journals (Sweden)

    M Modi

    2009-03-01

    Full Text Available Conjoined twins are rare variants of monozygotic twins. There are many types of conjoined twins, and they are usually classified at the point at which they are fused. Our patient fitted into a thoraco-omphalopagus type, where there was fusion of the thorax as well as mid-trunk [3]. The most common type of renal fusion anomaly is the horseshoe kidney. It consists of 2 distinct functioning kidneys on each side of the midline, and they are more likely to be connected at the lower poles [4]. We describe here a 30 year-old patient who presented to the antenatal clinic of Chris Hani Baragwanath hospital in Soweto, South Africa at 34+ weeks gestation. Foetal magnetic resonance imaging revealed thoraco-omphalopagus conjoined twins with complex thoracic and abdominal structures, including a horseshoe kidney that was confirmed on post-natal computed tomography.

  3. Micromechanics of twinning in a TWIP steel

    International Nuclear Information System (INIS)

    The deformation behaviour of a TWinning Induced Plasticity (TWIP) steel was studied at quasi-static strain rates using synchrotron X-ray diffraction. A {111} RD and {200} RD texture developed from the earliest stages of deformation, which could be reproduced using an elasto-plastic self consistent (EPSC) model. Evidence is found from multiple sources to suggest that twinning was occurring before macroscopic yielding. This included small deviations in the lattice strains, {111} intensity changes and peak width broadening all occurring below the macroscopic yield point. The accumulation of permanent deformation on sub-yield mechanical cycling of the material was found, which further supports the diffraction data. TEM revealed that fine deformation twins similar to those observed in heavily deformed samples formed during sub-yield cycling. It is concluded that twinning had occurred before macroscopic plastic deformation began, unlike the behaviour traditionally expected from hexagonal metals such as Mg

  4. Twin Screw Mixer/Fine Grind Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The 40-mm Twin-Screw Mixer/Extruder (TSE) pilot plant is a continuous, remotely operated, flexible facility that can significantly enhance safety and environmental...

  5. Twin Cities Metro Hybrid Landcover 2000 (Raster)

    Data.gov (United States)

    Minnesota Department of Natural Resources — The Hybrid Landcover is an attempt to clean up the University of Minnesota Remote Sensing Lab's 2000 LandSat Land Cover for the Twin Cities 7-county metropolitan...

  6. Idiopathic Hypertrophic Pyloric Stenosis in Identical Twins.

    OpenAIRE

    Ju-Bei Yen; Man-Shan Kong; Wan-Jao Wu; Chen-Sheng Huang; Kuei-Wen Chang

    2003-01-01

    Idiopathic hypertrophic pyloric stenosis (IHPS) was thought to be a congenital diseasetraditionally, even though several published reports assumed IHPS was an acquired disease.The pathogenesis and inheritance patterns of IHPS are not fully understood. Except for thefamilial recurrence of IHPS, concordance of IHPS in monozygotic or dizygotic twins wasalso noted, but occurrence in female twins is rare. From July 1992 through June 2000, 130patients were diagnosed with IHPS in our hospital includ...

  7. Severe Anisometropic Myopia in Identical Twins

    OpenAIRE

    Adenuga, Olukorede O.

    2014-01-01

    High anisometropic myopia is a rare condition in twins. Genetic factors have been implicated in its development and there may be an association with vision-threatening complications. A pair of 11-year-old twins presented with poor distance vision in both eyes. Detailed ocular examination was performed including slit lamp examination, dilated funduscopy, cycloplegic refraction, keratometry and axial length measurement. The objective refraction was -6.50DS -2.00DC × 180 (right eye), -1.00DS (le...

  8. Anaesthetic Management of Conjoined Twins' Separation Surgery

    OpenAIRE

    Chalam, Kolli S

    2009-01-01

    Summary Anaesthesia for conjoined twins, either for separation surgery, or for MRI or other evaluation procedures is an enormous challenge to the paediatric anaesthesiologist. This is an extra challenging surgery because we the anaesthesiologists need to care for two patients at the same time instead of just one. Anaesthesia for conjoined twins ‘separation surgery mainly centered on the following concerns: 1.Conjoined Twins’ physiology like crossed circulation, distribution of blood volume an...

  9. The Twin Research Registry at SRI International.

    Science.gov (United States)

    Krasnow, Ruth E; Jack, Lisa M; Lessov-Schlaggar, Christina N; Bergen, Andrew W; Swan, Gary E

    2013-02-01

    The Twin Research Registry (TRR) at SRI International is a community-based registry of twins established in 1995 by advertising in local media, mainly on radio stations and in newspapers. As of August 2012, there are 3,120 same- and opposite-sex twins enrolled; 86% are 18 years of age or older (mean age 44.9 years, SD 16.9 years) and 14% less than 18 years of age (mean age 8.9 years, SD 4.5); 67% are female, and 62% are self-reported monozygotic (MZ). More than 1,375 twins have participated in studies over the last 15 years in collaboration with the University of California Medical Center in San Francisco, the University of Texas MD Anderson Cancer Center, and the Stanford University School of Medicine. Each twin completes a registration form with basic demographic information either online at the TRR Web site or during a telephone interview. Contact is maintained with members by means of annual newsletters and birthday cards. The managers of the TRR protect the confidentiality of twin data with established policies; no information is given to other researchers without prior permission from the twins; and all methods and procedures are reviewed by an Institutional Review Board. Phenotypes studied thus far include those related to nicotine metabolism, mutagen sensitivity, pain response before and after administration of an opioid, and a variety of immunological responses to environmental exposures, including second-hand smoke and vaccination for seasonal influenza virus and Varicella zoster virus. Twins in the TRR have participated in studies of complex, clinically relevant phenotypes that would not be feasible to measure in larger samples. PMID:23084148

  10. TWIN: Personality-based Intelligent Recommender System

    OpenAIRE

    Roshchina, Alexandra; Cardiff, John; Rosso, Paolo

    2015-01-01

    This paper presents the Tell me What I Need (TWIN) Personality-based Intelligent Recommender System, the goal of which is to recommend items chosen by like-minded (or twin ) people with similar personality types which we estimate from their writings. In order to produce recommendations it applies the results achieved in the personality from the text recognition research field to Personality-based Recommender System user profile modelling. In this way it creates a bridge between the efforts...

  11. Imperfect twinning - evaluation by imaging methods

    International Nuclear Information System (INIS)

    Conjoined twins are rare malformations and a challenge for both radiologists and pediatric surgeons. Antenatal evaluation is essential for the identification of anatomic fusions and other associated abnormalities, which will enable an adequate surgical planning and the assessment of fetal prognosis. The authors present the clinical and imaging findings of thoracopagus twins, joined by the anterior portion of the thorax, sharing the heart and the liver. Diagnosis was made by ultrasonography and confirmed with fetal magnetic resonance imaging. (author)

  12. Anaesthesia of conjoined twins - case series.

    Science.gov (United States)

    Kobylarz, Krzysztof

    2014-01-01

    As any complex surgical procedure, separation of conjoined twins requires complex anaesthesia management that is a prerequisite of performing the operation, while complex postoperative care is a decisive factor in the survival of the patients. The paper describes the anaesthetic management for surgical operations in ten sets of conjoined twins in the Children's Hospital of Cracow during 1977-2005. The anaesthetic technique and associated problems are summarized. PMID:24858964

  13. Stolen twin: fascination and curiosity/twin research reports: evolution of sleep length; dental treatment of craniopagus twins; cryopreserved double embryo transfer; gender options in multiple pregnancy/current events: appendectomy in one twin; autistic twin marathon runners; 3D facial recognition; twin biathletes.

    Science.gov (United States)

    Segal, Nancy L

    2014-02-01

    The story of her allegedly stolen twin brother in Armenia is recounted by a 'singleton twin' living in the United States. The behavioral consequences and societal implications of this loss are considered. This case is followed by twin research reports on the evolution of sleep length, dental treatment of craniopagus conjoined twins, cryopreserved double embryo transfer (DET), and gender options in multiple pregnancy. Current events include the diagnosis of appendectomy in one identical twin, the accomplishments of autistic twin marathon runners, the power of three-dimensional (3D) facial recognition, and the goals of twin biathletes heading to the 2014 Sochi Olympics in Russia. PMID:24418634

  14. Quantum discord length is enhanced while entanglement length is not by introducing disorder in a spin chain.

    Science.gov (United States)

    Sadhukhan, Debasis; Roy, Sudipto Singha; Rakshit, Debraj; Prabhu, R; Sen De, Aditi; Sen, Ujjwal

    2016-01-01

    Classical correlation functions of ground states typically decay exponentially and polynomially, respectively, for gapped and gapless short-range quantum spin systems. In such systems, entanglement decays exponentially even at the quantum critical points. However, quantum discord, an information-theoretic quantum correlation measure, survives long lattice distances. We investigate the effects of quenched disorder on quantum correlation lengths of quenched averaged entanglement and quantum discord, in the anisotropic XY and XYZ spin glass and random field chains. We find that there is virtually neither reduction nor enhancement in entanglement length while quantum discord length increases significantly with the introduction of the quenched disorder. PMID:26871048

  15. Urticaria in monozygotic and dizygotic twins

    DEFF Research Database (Denmark)

    Thomsen, Simon Francis; van der Sluis, Sophie; Kyvik, Kirsten Ohm; Backer, Vibeke

    2012-01-01

    Aim. To identify risk factors for urticaria, to determine the relative proportion of the susceptibility to urticaria that is due to genetic factors in an adult clinical twin sample, and to further determine whether the genetic susceptibility to urticaria overlaps with the genetic susceptibility to...... atopic diseases. Methods. A total of 256 complete twin pairs and 63 single twins, who were selected from sibships with self-reported asthma via a questionnaire survey of 21,162 adult twins from the Danish Twin Registry, were clinically interviewed about a history of urticaria and examined for atopic.......36-2.72), P = 0.000; and atopic dermatitis, HR = 1.44 (1.02-2.06), P = 0.041 were significant risk factors for urticaria. After adjustment for sex and age at onset of urticaria in the index twin, the risk of urticaria was increased in MZ cotwins relative to DZ cotwins, HR = 1.42 (0.63-3.18), P = 0...

  16. Exotic Quarks in Twin Higgs Models

    CERN Document Server

    Cheng, Hsin-Chia; Salvioni, Ennio; Tsai, Yuhsin

    2015-01-01

    The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ~ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of the model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles ...

  17. Twin pregnancy in the congenital malformed uterus.

    Science.gov (United States)

    Heinonen, Pentti K

    2016-07-01

    The frequency and outcome of twin pregnancies in women with uterine malformation were studied. The cohort comprised 13 (4.9%) women with twin pregnancy found among 263 women. They had 483 deliveries, 13 of them twins (2.7%; 95% CI 1.6-4.6%). Among 38 patients with unicornuate uterus 5 (6.8%) out of 74 deliveries were twins, 39 women with didelphic uterus 2 (3.2%) out of 62 deliveries and 147 women with septate or subseptate uterus 6 (2.3%) out of 264 deliveries were twins. The mean duration of gestation was 249 days (range 190-268 days), 5 (38%) out of 13 deliveries were premature, 25 out of 26 newborns were alive. Mean durations of gestation and mean weights of newborns did not differ when 7 cases with unicornuate or didelphic uterus were compared to 6 cases with complete or partial uterine septum. A congenital malformed uterus can bear twin pregnancy without severe complications apart from prematurity. PMID:26757792

  18. Imperfect twinning: a clinical and ethical dilemma

    Directory of Open Access Journals (Sweden)

    Daniela Denardin

    2013-09-01

    Full Text Available OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. DATA SYNTHESIS: The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family.

  19. Plagioclase twin laws in lunar highland rocks - Possible petrogenetic significance

    Science.gov (United States)

    Dowty, E.; Keil, K.; Prinz, M.

    1974-01-01

    Plagioclases in different types of lunar highland rocks (all highly feldspathic) are twinned according to different laws and in different styles. Carlsbad and Carlsbad-albite twins, presumed to be growth twins, occur mainly in rocks which show igneous texture, and which have not been severely brecciated. These two twin laws appear to be absent from cataclastic rocks, including cataclastic anorthosite, possibly because the original twins were preferentially broken up in cataclasis (the composition plane being a plane of weakness). Pericline and lamellar albite twins, presumed to be deformation twins (except for some albite growth twins) occur in all types of rocks, and obvious deformation features, such as bending of lamellae, are well shown in many cataclastic rocks. Surprisingly, some Carlsbad and Carlsbad-albite twins are found in rocks with granoblastic texture, which presumably recrystallized in the solid state.

  20. Twin probes for space geodesy

    International Nuclear Information System (INIS)

    The twin probe method, proposed by Bertotti and Colombo (1972) to get rid of nongravitational forces in interplanetary space, can be applied to a near-Earth orbit to eliminate the atmospheric drag. Two equal pairs of probes, each pair consisting of two passive, small and dense spheres of equal surface and different masses, are flown on a circular orbit at an altitude of about 300 km. Each pair determines the motion of an ideal point which feels only the gravitational forces. They are separated by a distance d of (100/200) km and are tracked from a spacecraft or the Space Shuttle, flying at the same altitude. The relative motion of the two ideal points is reconstructed and yields a measurement of the fine structure of the Earth gravitational field, corresponding to a harmonic order l approximately a/d (a is the radius of the Earth). The tracking can be done by laser ranging to the four spheres, covered by corner reflectors; Doppler ranging is more convenient for higher values of l and can also be used. The accuracy in the compensation of the non-gravitational forces and in the measurements one needs for a given l are discussed in detail. (author)